1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * NET An implementation of the SOCKET network access protocol.
4 *
5 * Version: @(#)socket.c 1.1.93 18/02/95
6 *
7 * Authors: Orest Zborowski, <obz@Kodak.COM>
8 * Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 *
11 * Fixes:
12 * Anonymous : NOTSOCK/BADF cleanup. Error fix in
13 * shutdown()
14 * Alan Cox : verify_area() fixes
15 * Alan Cox : Removed DDI
16 * Jonathan Kamens : SOCK_DGRAM reconnect bug
17 * Alan Cox : Moved a load of checks to the very
18 * top level.
19 * Alan Cox : Move address structures to/from user
20 * mode above the protocol layers.
21 * Rob Janssen : Allow 0 length sends.
22 * Alan Cox : Asynchronous I/O support (cribbed from the
23 * tty drivers).
24 * Niibe Yutaka : Asynchronous I/O for writes (4.4BSD style)
25 * Jeff Uphoff : Made max number of sockets command-line
26 * configurable.
27 * Matti Aarnio : Made the number of sockets dynamic,
28 * to be allocated when needed, and mr.
29 * Uphoff's max is used as max to be
30 * allowed to allocate.
31 * Linus : Argh. removed all the socket allocation
32 * altogether: it's in the inode now.
33 * Alan Cox : Made sock_alloc()/sock_release() public
34 * for NetROM and future kernel nfsd type
35 * stuff.
36 * Alan Cox : sendmsg/recvmsg basics.
37 * Tom Dyas : Export net symbols.
38 * Marcin Dalecki : Fixed problems with CONFIG_NET="n".
39 * Alan Cox : Added thread locking to sys_* calls
40 * for sockets. May have errors at the
41 * moment.
42 * Kevin Buhr : Fixed the dumb errors in the above.
43 * Andi Kleen : Some small cleanups, optimizations,
44 * and fixed a copy_from_user() bug.
45 * Tigran Aivazian : sys_send(args) calls sys_sendto(args, NULL, 0)
46 * Tigran Aivazian : Made listen(2) backlog sanity checks
47 * protocol-independent
48 *
49 * This module is effectively the top level interface to the BSD socket
50 * paradigm.
51 *
52 * Based upon Swansea University Computer Society NET3.039
53 */
54
55 #include <linux/bpf-cgroup.h>
56 #include <linux/ethtool.h>
57 #include <linux/mm.h>
58 #include <linux/socket.h>
59 #include <linux/file.h>
60 #include <linux/splice.h>
61 #include <linux/net.h>
62 #include <linux/interrupt.h>
63 #include <linux/thread_info.h>
64 #include <linux/rcupdate.h>
65 #include <linux/netdevice.h>
66 #include <linux/proc_fs.h>
67 #include <linux/seq_file.h>
68 #include <linux/mutex.h>
69 #include <linux/if_bridge.h>
70 #include <linux/if_vlan.h>
71 #include <linux/ptp_classify.h>
72 #include <linux/init.h>
73 #include <linux/poll.h>
74 #include <linux/cache.h>
75 #include <linux/module.h>
76 #include <linux/highmem.h>
77 #include <linux/mount.h>
78 #include <linux/pseudo_fs.h>
79 #include <linux/security.h>
80 #include <linux/syscalls.h>
81 #include <linux/compat.h>
82 #include <linux/kmod.h>
83 #include <linux/audit.h>
84 #include <linux/wireless.h>
85 #include <linux/nsproxy.h>
86 #include <linux/magic.h>
87 #include <linux/slab.h>
88 #include <linux/xattr.h>
89 #include <linux/nospec.h>
90 #include <linux/indirect_call_wrapper.h>
91 #include <linux/io_uring/net.h>
92
93 #include <linux/uaccess.h>
94 #include <asm/unistd.h>
95
96 #include <net/compat.h>
97 #include <net/wext.h>
98 #include <net/cls_cgroup.h>
99
100 #include <net/sock.h>
101 #include <linux/netfilter.h>
102
103 #include <linux/if_tun.h>
104 #include <linux/ipv6_route.h>
105 #include <linux/route.h>
106 #include <linux/termios.h>
107 #include <linux/sockios.h>
108 #include <net/busy_poll.h>
109 #include <linux/errqueue.h>
110 #include <linux/ptp_clock_kernel.h>
111 #include <trace/events/sock.h>
112
113 #include "core/dev.h"
114
115 #ifdef CONFIG_NET_RX_BUSY_POLL
116 unsigned int sysctl_net_busy_read __read_mostly;
117 unsigned int sysctl_net_busy_poll __read_mostly;
118 #endif
119
120 static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to);
121 static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from);
122 static int sock_mmap(struct file *file, struct vm_area_struct *vma);
123
124 static int sock_close(struct inode *inode, struct file *file);
125 static __poll_t sock_poll(struct file *file,
126 struct poll_table_struct *wait);
127 static long sock_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
128 #ifdef CONFIG_COMPAT
129 static long compat_sock_ioctl(struct file *file,
130 unsigned int cmd, unsigned long arg);
131 #endif
132 static int sock_fasync(int fd, struct file *filp, int on);
133 static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
134 struct pipe_inode_info *pipe, size_t len,
135 unsigned int flags);
136 static void sock_splice_eof(struct file *file);
137
138 #ifdef CONFIG_PROC_FS
sock_show_fdinfo(struct seq_file * m,struct file * f)139 static void sock_show_fdinfo(struct seq_file *m, struct file *f)
140 {
141 struct socket *sock = f->private_data;
142 const struct proto_ops *ops = READ_ONCE(sock->ops);
143
144 if (ops->show_fdinfo)
145 ops->show_fdinfo(m, sock);
146 }
147 #else
148 #define sock_show_fdinfo NULL
149 #endif
150
151 /*
152 * Socket files have a set of 'special' operations as well as the generic file ones. These don't appear
153 * in the operation structures but are done directly via the socketcall() multiplexor.
154 */
155
156 static const struct file_operations socket_file_ops = {
157 .owner = THIS_MODULE,
158 .read_iter = sock_read_iter,
159 .write_iter = sock_write_iter,
160 .poll = sock_poll,
161 .unlocked_ioctl = sock_ioctl,
162 #ifdef CONFIG_COMPAT
163 .compat_ioctl = compat_sock_ioctl,
164 #endif
165 .uring_cmd = io_uring_cmd_sock,
166 .mmap = sock_mmap,
167 .release = sock_close,
168 .fasync = sock_fasync,
169 .splice_write = splice_to_socket,
170 .splice_read = sock_splice_read,
171 .splice_eof = sock_splice_eof,
172 .show_fdinfo = sock_show_fdinfo,
173 };
174
175 static const char * const pf_family_names[] = {
176 [PF_UNSPEC] = "PF_UNSPEC",
177 [PF_UNIX] = "PF_UNIX/PF_LOCAL",
178 [PF_INET] = "PF_INET",
179 [PF_AX25] = "PF_AX25",
180 [PF_IPX] = "PF_IPX",
181 [PF_APPLETALK] = "PF_APPLETALK",
182 [PF_NETROM] = "PF_NETROM",
183 [PF_BRIDGE] = "PF_BRIDGE",
184 [PF_ATMPVC] = "PF_ATMPVC",
185 [PF_X25] = "PF_X25",
186 [PF_INET6] = "PF_INET6",
187 [PF_ROSE] = "PF_ROSE",
188 [PF_DECnet] = "PF_DECnet",
189 [PF_NETBEUI] = "PF_NETBEUI",
190 [PF_SECURITY] = "PF_SECURITY",
191 [PF_KEY] = "PF_KEY",
192 [PF_NETLINK] = "PF_NETLINK/PF_ROUTE",
193 [PF_PACKET] = "PF_PACKET",
194 [PF_ASH] = "PF_ASH",
195 [PF_ECONET] = "PF_ECONET",
196 [PF_ATMSVC] = "PF_ATMSVC",
197 [PF_RDS] = "PF_RDS",
198 [PF_SNA] = "PF_SNA",
199 [PF_IRDA] = "PF_IRDA",
200 [PF_PPPOX] = "PF_PPPOX",
201 [PF_WANPIPE] = "PF_WANPIPE",
202 [PF_LLC] = "PF_LLC",
203 [PF_IB] = "PF_IB",
204 [PF_MPLS] = "PF_MPLS",
205 [PF_CAN] = "PF_CAN",
206 [PF_TIPC] = "PF_TIPC",
207 [PF_BLUETOOTH] = "PF_BLUETOOTH",
208 [PF_IUCV] = "PF_IUCV",
209 [PF_RXRPC] = "PF_RXRPC",
210 [PF_ISDN] = "PF_ISDN",
211 [PF_PHONET] = "PF_PHONET",
212 [PF_IEEE802154] = "PF_IEEE802154",
213 [PF_CAIF] = "PF_CAIF",
214 [PF_ALG] = "PF_ALG",
215 [PF_NFC] = "PF_NFC",
216 [PF_VSOCK] = "PF_VSOCK",
217 [PF_KCM] = "PF_KCM",
218 [PF_QIPCRTR] = "PF_QIPCRTR",
219 [PF_SMC] = "PF_SMC",
220 [PF_XDP] = "PF_XDP",
221 [PF_MCTP] = "PF_MCTP",
222 };
223
224 /*
225 * The protocol list. Each protocol is registered in here.
226 */
227
228 static DEFINE_SPINLOCK(net_family_lock);
229 static const struct net_proto_family __rcu *net_families[NPROTO] __read_mostly;
230
231 /*
232 * Support routines.
233 * Move socket addresses back and forth across the kernel/user
234 * divide and look after the messy bits.
235 */
236
237 /**
238 * move_addr_to_kernel - copy a socket address into kernel space
239 * @uaddr: Address in user space
240 * @kaddr: Address in kernel space
241 * @ulen: Length in user space
242 *
243 * The address is copied into kernel space. If the provided address is
244 * too long an error code of -EINVAL is returned. If the copy gives
245 * invalid addresses -EFAULT is returned. On a success 0 is returned.
246 */
247
move_addr_to_kernel(void __user * uaddr,int ulen,struct sockaddr_storage * kaddr)248 int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr)
249 {
250 if (ulen < 0 || ulen > sizeof(struct sockaddr_storage))
251 return -EINVAL;
252 if (ulen == 0)
253 return 0;
254 if (copy_from_user(kaddr, uaddr, ulen))
255 return -EFAULT;
256 return audit_sockaddr(ulen, kaddr);
257 }
258
259 /**
260 * move_addr_to_user - copy an address to user space
261 * @kaddr: kernel space address
262 * @klen: length of address in kernel
263 * @uaddr: user space address
264 * @ulen: pointer to user length field
265 *
266 * The value pointed to by ulen on entry is the buffer length available.
267 * This is overwritten with the buffer space used. -EINVAL is returned
268 * if an overlong buffer is specified or a negative buffer size. -EFAULT
269 * is returned if either the buffer or the length field are not
270 * accessible.
271 * After copying the data up to the limit the user specifies, the true
272 * length of the data is written over the length limit the user
273 * specified. Zero is returned for a success.
274 */
275
move_addr_to_user(struct sockaddr_storage * kaddr,int klen,void __user * uaddr,int __user * ulen)276 static int move_addr_to_user(struct sockaddr_storage *kaddr, int klen,
277 void __user *uaddr, int __user *ulen)
278 {
279 int err;
280 int len;
281
282 BUG_ON(klen > sizeof(struct sockaddr_storage));
283 err = get_user(len, ulen);
284 if (err)
285 return err;
286 if (len > klen)
287 len = klen;
288 if (len < 0)
289 return -EINVAL;
290 if (len) {
291 if (audit_sockaddr(klen, kaddr))
292 return -ENOMEM;
293 if (copy_to_user(uaddr, kaddr, len))
294 return -EFAULT;
295 }
296 /*
297 * "fromlen shall refer to the value before truncation.."
298 * 1003.1g
299 */
300 return __put_user(klen, ulen);
301 }
302
303 static struct kmem_cache *sock_inode_cachep __ro_after_init;
304
sock_alloc_inode(struct super_block * sb)305 static struct inode *sock_alloc_inode(struct super_block *sb)
306 {
307 struct socket_alloc *ei;
308
309 ei = alloc_inode_sb(sb, sock_inode_cachep, GFP_KERNEL);
310 if (!ei)
311 return NULL;
312 init_waitqueue_head(&ei->socket.wq.wait);
313 ei->socket.wq.fasync_list = NULL;
314 ei->socket.wq.flags = 0;
315
316 ei->socket.state = SS_UNCONNECTED;
317 ei->socket.flags = 0;
318 ei->socket.ops = NULL;
319 ei->socket.sk = NULL;
320 ei->socket.file = NULL;
321
322 return &ei->vfs_inode;
323 }
324
sock_free_inode(struct inode * inode)325 static void sock_free_inode(struct inode *inode)
326 {
327 struct socket_alloc *ei;
328
329 ei = container_of(inode, struct socket_alloc, vfs_inode);
330 kmem_cache_free(sock_inode_cachep, ei);
331 }
332
init_once(void * foo)333 static void init_once(void *foo)
334 {
335 struct socket_alloc *ei = (struct socket_alloc *)foo;
336
337 inode_init_once(&ei->vfs_inode);
338 }
339
init_inodecache(void)340 static void init_inodecache(void)
341 {
342 sock_inode_cachep = kmem_cache_create("sock_inode_cache",
343 sizeof(struct socket_alloc),
344 0,
345 (SLAB_HWCACHE_ALIGN |
346 SLAB_RECLAIM_ACCOUNT |
347 SLAB_ACCOUNT),
348 init_once);
349 BUG_ON(sock_inode_cachep == NULL);
350 }
351
352 static const struct super_operations sockfs_ops = {
353 .alloc_inode = sock_alloc_inode,
354 .free_inode = sock_free_inode,
355 .statfs = simple_statfs,
356 };
357
358 /*
359 * sockfs_dname() is called from d_path().
360 */
sockfs_dname(struct dentry * dentry,char * buffer,int buflen)361 static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen)
362 {
363 return dynamic_dname(buffer, buflen, "socket:[%lu]",
364 d_inode(dentry)->i_ino);
365 }
366
367 static const struct dentry_operations sockfs_dentry_operations = {
368 .d_dname = sockfs_dname,
369 };
370
sockfs_xattr_get(const struct xattr_handler * handler,struct dentry * dentry,struct inode * inode,const char * suffix,void * value,size_t size)371 static int sockfs_xattr_get(const struct xattr_handler *handler,
372 struct dentry *dentry, struct inode *inode,
373 const char *suffix, void *value, size_t size)
374 {
375 if (value) {
376 if (dentry->d_name.len + 1 > size)
377 return -ERANGE;
378 memcpy(value, dentry->d_name.name, dentry->d_name.len + 1);
379 }
380 return dentry->d_name.len + 1;
381 }
382
383 #define XATTR_SOCKPROTONAME_SUFFIX "sockprotoname"
384 #define XATTR_NAME_SOCKPROTONAME (XATTR_SYSTEM_PREFIX XATTR_SOCKPROTONAME_SUFFIX)
385 #define XATTR_NAME_SOCKPROTONAME_LEN (sizeof(XATTR_NAME_SOCKPROTONAME)-1)
386
387 static const struct xattr_handler sockfs_xattr_handler = {
388 .name = XATTR_NAME_SOCKPROTONAME,
389 .get = sockfs_xattr_get,
390 };
391
sockfs_security_xattr_set(const struct xattr_handler * handler,struct mnt_idmap * idmap,struct dentry * dentry,struct inode * inode,const char * suffix,const void * value,size_t size,int flags)392 static int sockfs_security_xattr_set(const struct xattr_handler *handler,
393 struct mnt_idmap *idmap,
394 struct dentry *dentry, struct inode *inode,
395 const char *suffix, const void *value,
396 size_t size, int flags)
397 {
398 /* Handled by LSM. */
399 return -EAGAIN;
400 }
401
402 static const struct xattr_handler sockfs_security_xattr_handler = {
403 .prefix = XATTR_SECURITY_PREFIX,
404 .set = sockfs_security_xattr_set,
405 };
406
407 static const struct xattr_handler * const sockfs_xattr_handlers[] = {
408 &sockfs_xattr_handler,
409 &sockfs_security_xattr_handler,
410 NULL
411 };
412
sockfs_init_fs_context(struct fs_context * fc)413 static int sockfs_init_fs_context(struct fs_context *fc)
414 {
415 struct pseudo_fs_context *ctx = init_pseudo(fc, SOCKFS_MAGIC);
416 if (!ctx)
417 return -ENOMEM;
418 ctx->ops = &sockfs_ops;
419 ctx->dops = &sockfs_dentry_operations;
420 ctx->xattr = sockfs_xattr_handlers;
421 return 0;
422 }
423
424 static struct vfsmount *sock_mnt __read_mostly;
425
426 static struct file_system_type sock_fs_type = {
427 .name = "sockfs",
428 .init_fs_context = sockfs_init_fs_context,
429 .kill_sb = kill_anon_super,
430 };
431
432 /*
433 * Obtains the first available file descriptor and sets it up for use.
434 *
435 * These functions create file structures and maps them to fd space
436 * of the current process. On success it returns file descriptor
437 * and file struct implicitly stored in sock->file.
438 * Note that another thread may close file descriptor before we return
439 * from this function. We use the fact that now we do not refer
440 * to socket after mapping. If one day we will need it, this
441 * function will increment ref. count on file by 1.
442 *
443 * In any case returned fd MAY BE not valid!
444 * This race condition is unavoidable
445 * with shared fd spaces, we cannot solve it inside kernel,
446 * but we take care of internal coherence yet.
447 */
448
449 /**
450 * sock_alloc_file - Bind a &socket to a &file
451 * @sock: socket
452 * @flags: file status flags
453 * @dname: protocol name
454 *
455 * Returns the &file bound with @sock, implicitly storing it
456 * in sock->file. If dname is %NULL, sets to "".
457 *
458 * On failure @sock is released, and an ERR pointer is returned.
459 *
460 * This function uses GFP_KERNEL internally.
461 */
462
sock_alloc_file(struct socket * sock,int flags,const char * dname)463 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
464 {
465 struct file *file;
466
467 if (!dname)
468 dname = sock->sk ? sock->sk->sk_prot_creator->name : "";
469
470 file = alloc_file_pseudo(SOCK_INODE(sock), sock_mnt, dname,
471 O_RDWR | (flags & O_NONBLOCK),
472 &socket_file_ops);
473 if (IS_ERR(file)) {
474 sock_release(sock);
475 return file;
476 }
477
478 file->f_mode |= FMODE_NOWAIT;
479 sock->file = file;
480 file->private_data = sock;
481 stream_open(SOCK_INODE(sock), file);
482 /*
483 * Disable permission and pre-content events, but enable legacy
484 * inotify events for legacy users.
485 */
486 file_set_fsnotify_mode(file, FMODE_NONOTIFY_PERM);
487 return file;
488 }
489 EXPORT_SYMBOL(sock_alloc_file);
490
sock_map_fd(struct socket * sock,int flags)491 static int sock_map_fd(struct socket *sock, int flags)
492 {
493 struct file *newfile;
494 int fd = get_unused_fd_flags(flags);
495 if (unlikely(fd < 0)) {
496 sock_release(sock);
497 return fd;
498 }
499
500 newfile = sock_alloc_file(sock, flags, NULL);
501 if (!IS_ERR(newfile)) {
502 fd_install(fd, newfile);
503 return fd;
504 }
505
506 put_unused_fd(fd);
507 return PTR_ERR(newfile);
508 }
509
510 /**
511 * sock_from_file - Return the &socket bounded to @file.
512 * @file: file
513 *
514 * On failure returns %NULL.
515 */
516
sock_from_file(struct file * file)517 struct socket *sock_from_file(struct file *file)
518 {
519 if (likely(file->f_op == &socket_file_ops))
520 return file->private_data; /* set in sock_alloc_file */
521
522 return NULL;
523 }
524 EXPORT_SYMBOL(sock_from_file);
525
526 /**
527 * sockfd_lookup - Go from a file number to its socket slot
528 * @fd: file handle
529 * @err: pointer to an error code return
530 *
531 * The file handle passed in is locked and the socket it is bound
532 * to is returned. If an error occurs the err pointer is overwritten
533 * with a negative errno code and NULL is returned. The function checks
534 * for both invalid handles and passing a handle which is not a socket.
535 *
536 * On a success the socket object pointer is returned.
537 */
538
sockfd_lookup(int fd,int * err)539 struct socket *sockfd_lookup(int fd, int *err)
540 {
541 struct file *file;
542 struct socket *sock;
543
544 file = fget(fd);
545 if (!file) {
546 *err = -EBADF;
547 return NULL;
548 }
549
550 sock = sock_from_file(file);
551 if (!sock) {
552 *err = -ENOTSOCK;
553 fput(file);
554 }
555 return sock;
556 }
557 EXPORT_SYMBOL(sockfd_lookup);
558
sockfs_listxattr(struct dentry * dentry,char * buffer,size_t size)559 static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer,
560 size_t size)
561 {
562 ssize_t len;
563 ssize_t used = 0;
564
565 len = security_inode_listsecurity(d_inode(dentry), buffer, size);
566 if (len < 0)
567 return len;
568 used += len;
569 if (buffer) {
570 if (size < used)
571 return -ERANGE;
572 buffer += len;
573 }
574
575 len = (XATTR_NAME_SOCKPROTONAME_LEN + 1);
576 used += len;
577 if (buffer) {
578 if (size < used)
579 return -ERANGE;
580 memcpy(buffer, XATTR_NAME_SOCKPROTONAME, len);
581 buffer += len;
582 }
583
584 return used;
585 }
586
sockfs_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)587 static int sockfs_setattr(struct mnt_idmap *idmap,
588 struct dentry *dentry, struct iattr *iattr)
589 {
590 int err = simple_setattr(&nop_mnt_idmap, dentry, iattr);
591
592 if (!err && (iattr->ia_valid & ATTR_UID)) {
593 struct socket *sock = SOCKET_I(d_inode(dentry));
594
595 if (sock->sk) {
596 /* Paired with READ_ONCE() in sk_uid() */
597 WRITE_ONCE(sock->sk->sk_uid, iattr->ia_uid);
598 } else {
599 err = -ENOENT;
600 }
601 }
602
603 return err;
604 }
605
606 static const struct inode_operations sockfs_inode_ops = {
607 .listxattr = sockfs_listxattr,
608 .setattr = sockfs_setattr,
609 };
610
611 /**
612 * sock_alloc - allocate a socket
613 *
614 * Allocate a new inode and socket object. The two are bound together
615 * and initialised. The socket is then returned. If we are out of inodes
616 * NULL is returned. This functions uses GFP_KERNEL internally.
617 */
618
sock_alloc(void)619 struct socket *sock_alloc(void)
620 {
621 struct inode *inode;
622 struct socket *sock;
623
624 inode = new_inode_pseudo(sock_mnt->mnt_sb);
625 if (!inode)
626 return NULL;
627
628 sock = SOCKET_I(inode);
629
630 inode->i_ino = get_next_ino();
631 inode->i_mode = S_IFSOCK | S_IRWXUGO;
632 inode->i_uid = current_fsuid();
633 inode->i_gid = current_fsgid();
634 inode->i_op = &sockfs_inode_ops;
635
636 return sock;
637 }
638 EXPORT_SYMBOL(sock_alloc);
639
__sock_release(struct socket * sock,struct inode * inode)640 static void __sock_release(struct socket *sock, struct inode *inode)
641 {
642 const struct proto_ops *ops = READ_ONCE(sock->ops);
643
644 if (ops) {
645 struct module *owner = ops->owner;
646
647 if (inode)
648 inode_lock(inode);
649 ops->release(sock);
650 sock->sk = NULL;
651 if (inode)
652 inode_unlock(inode);
653 sock->ops = NULL;
654 module_put(owner);
655 }
656
657 if (sock->wq.fasync_list)
658 pr_err("%s: fasync list not empty!\n", __func__);
659
660 if (!sock->file) {
661 iput(SOCK_INODE(sock));
662 return;
663 }
664 sock->file = NULL;
665 }
666
667 /**
668 * sock_release - close a socket
669 * @sock: socket to close
670 *
671 * The socket is released from the protocol stack if it has a release
672 * callback, and the inode is then released if the socket is bound to
673 * an inode not a file.
674 */
sock_release(struct socket * sock)675 void sock_release(struct socket *sock)
676 {
677 __sock_release(sock, NULL);
678 }
679 EXPORT_SYMBOL(sock_release);
680
__sock_tx_timestamp(__u32 tsflags,__u8 * tx_flags)681 void __sock_tx_timestamp(__u32 tsflags, __u8 *tx_flags)
682 {
683 u8 flags = *tx_flags;
684
685 if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE)
686 flags |= SKBTX_HW_TSTAMP_NOBPF;
687
688 if (tsflags & SOF_TIMESTAMPING_TX_SOFTWARE)
689 flags |= SKBTX_SW_TSTAMP;
690
691 if (tsflags & SOF_TIMESTAMPING_TX_SCHED)
692 flags |= SKBTX_SCHED_TSTAMP;
693
694 if (tsflags & SOF_TIMESTAMPING_TX_COMPLETION)
695 flags |= SKBTX_COMPLETION_TSTAMP;
696
697 *tx_flags = flags;
698 }
699 EXPORT_SYMBOL(__sock_tx_timestamp);
700
701 INDIRECT_CALLABLE_DECLARE(int inet_sendmsg(struct socket *, struct msghdr *,
702 size_t));
703 INDIRECT_CALLABLE_DECLARE(int inet6_sendmsg(struct socket *, struct msghdr *,
704 size_t));
705
call_trace_sock_send_length(struct sock * sk,int ret,int flags)706 static noinline void call_trace_sock_send_length(struct sock *sk, int ret,
707 int flags)
708 {
709 trace_sock_send_length(sk, ret, 0);
710 }
711
sock_sendmsg_nosec(struct socket * sock,struct msghdr * msg)712 static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
713 {
714 int ret = INDIRECT_CALL_INET(READ_ONCE(sock->ops)->sendmsg, inet6_sendmsg,
715 inet_sendmsg, sock, msg,
716 msg_data_left(msg));
717 BUG_ON(ret == -EIOCBQUEUED);
718
719 if (trace_sock_send_length_enabled())
720 call_trace_sock_send_length(sock->sk, ret, 0);
721 return ret;
722 }
723
__sock_sendmsg(struct socket * sock,struct msghdr * msg)724 static int __sock_sendmsg(struct socket *sock, struct msghdr *msg)
725 {
726 int err = security_socket_sendmsg(sock, msg,
727 msg_data_left(msg));
728
729 return err ?: sock_sendmsg_nosec(sock, msg);
730 }
731
732 /**
733 * sock_sendmsg - send a message through @sock
734 * @sock: socket
735 * @msg: message to send
736 *
737 * Sends @msg through @sock, passing through LSM.
738 * Returns the number of bytes sent, or an error code.
739 */
sock_sendmsg(struct socket * sock,struct msghdr * msg)740 int sock_sendmsg(struct socket *sock, struct msghdr *msg)
741 {
742 struct sockaddr_storage *save_addr = (struct sockaddr_storage *)msg->msg_name;
743 struct sockaddr_storage address;
744 int save_len = msg->msg_namelen;
745 int ret;
746
747 if (msg->msg_name) {
748 memcpy(&address, msg->msg_name, msg->msg_namelen);
749 msg->msg_name = &address;
750 }
751
752 ret = __sock_sendmsg(sock, msg);
753 msg->msg_name = save_addr;
754 msg->msg_namelen = save_len;
755
756 return ret;
757 }
758 EXPORT_SYMBOL(sock_sendmsg);
759
760 /**
761 * kernel_sendmsg - send a message through @sock (kernel-space)
762 * @sock: socket
763 * @msg: message header
764 * @vec: kernel vec
765 * @num: vec array length
766 * @size: total message data size
767 *
768 * Builds the message data with @vec and sends it through @sock.
769 * Returns the number of bytes sent, or an error code.
770 */
771
kernel_sendmsg(struct socket * sock,struct msghdr * msg,struct kvec * vec,size_t num,size_t size)772 int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
773 struct kvec *vec, size_t num, size_t size)
774 {
775 iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, vec, num, size);
776 return sock_sendmsg(sock, msg);
777 }
778 EXPORT_SYMBOL(kernel_sendmsg);
779
skb_is_err_queue(const struct sk_buff * skb)780 static bool skb_is_err_queue(const struct sk_buff *skb)
781 {
782 /* pkt_type of skbs enqueued on the error queue are set to
783 * PACKET_OUTGOING in skb_set_err_queue(). This is only safe to do
784 * in recvmsg, since skbs received on a local socket will never
785 * have a pkt_type of PACKET_OUTGOING.
786 */
787 return skb->pkt_type == PACKET_OUTGOING;
788 }
789
790 /* On transmit, software and hardware timestamps are returned independently.
791 * As the two skb clones share the hardware timestamp, which may be updated
792 * before the software timestamp is received, a hardware TX timestamp may be
793 * returned only if there is no software TX timestamp. Ignore false software
794 * timestamps, which may be made in the __sock_recv_timestamp() call when the
795 * option SO_TIMESTAMP_OLD(NS) is enabled on the socket, even when the skb has a
796 * hardware timestamp.
797 */
skb_is_swtx_tstamp(const struct sk_buff * skb,int false_tstamp)798 static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp)
799 {
800 return skb->tstamp && !false_tstamp && skb_is_err_queue(skb);
801 }
802
get_timestamp(struct sock * sk,struct sk_buff * skb,int * if_index)803 static ktime_t get_timestamp(struct sock *sk, struct sk_buff *skb, int *if_index)
804 {
805 bool cycles = READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_BIND_PHC;
806 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
807 struct net_device *orig_dev;
808 ktime_t hwtstamp;
809
810 rcu_read_lock();
811 orig_dev = dev_get_by_napi_id(skb_napi_id(skb));
812 if (orig_dev) {
813 *if_index = orig_dev->ifindex;
814 hwtstamp = netdev_get_tstamp(orig_dev, shhwtstamps, cycles);
815 } else {
816 hwtstamp = shhwtstamps->hwtstamp;
817 }
818 rcu_read_unlock();
819
820 return hwtstamp;
821 }
822
put_ts_pktinfo(struct msghdr * msg,struct sk_buff * skb,int if_index)823 static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb,
824 int if_index)
825 {
826 struct scm_ts_pktinfo ts_pktinfo;
827 struct net_device *orig_dev;
828
829 if (!skb_mac_header_was_set(skb))
830 return;
831
832 memset(&ts_pktinfo, 0, sizeof(ts_pktinfo));
833
834 if (!if_index) {
835 rcu_read_lock();
836 orig_dev = dev_get_by_napi_id(skb_napi_id(skb));
837 if (orig_dev)
838 if_index = orig_dev->ifindex;
839 rcu_read_unlock();
840 }
841 ts_pktinfo.if_index = if_index;
842
843 ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb);
844 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO,
845 sizeof(ts_pktinfo), &ts_pktinfo);
846 }
847
skb_has_tx_timestamp(struct sk_buff * skb,const struct sock * sk)848 bool skb_has_tx_timestamp(struct sk_buff *skb, const struct sock *sk)
849 {
850 const struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
851 u32 tsflags = READ_ONCE(sk->sk_tsflags);
852
853 if (serr->ee.ee_errno != ENOMSG ||
854 serr->ee.ee_origin != SO_EE_ORIGIN_TIMESTAMPING)
855 return false;
856
857 /* software time stamp available and wanted */
858 if ((tsflags & SOF_TIMESTAMPING_SOFTWARE) && skb->tstamp)
859 return true;
860 /* hardware time stamps available and wanted */
861 return (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
862 skb_hwtstamps(skb)->hwtstamp;
863 }
864
skb_get_tx_timestamp(struct sk_buff * skb,struct sock * sk,struct timespec64 * ts)865 int skb_get_tx_timestamp(struct sk_buff *skb, struct sock *sk,
866 struct timespec64 *ts)
867 {
868 u32 tsflags = READ_ONCE(sk->sk_tsflags);
869 ktime_t hwtstamp;
870 int if_index = 0;
871
872 if ((tsflags & SOF_TIMESTAMPING_SOFTWARE) &&
873 ktime_to_timespec64_cond(skb->tstamp, ts))
874 return SOF_TIMESTAMPING_TX_SOFTWARE;
875
876 if (!(tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) ||
877 skb_is_swtx_tstamp(skb, false))
878 return -ENOENT;
879
880 if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV)
881 hwtstamp = get_timestamp(sk, skb, &if_index);
882 else
883 hwtstamp = skb_hwtstamps(skb)->hwtstamp;
884
885 if (tsflags & SOF_TIMESTAMPING_BIND_PHC)
886 hwtstamp = ptp_convert_timestamp(&hwtstamp,
887 READ_ONCE(sk->sk_bind_phc));
888 if (!ktime_to_timespec64_cond(hwtstamp, ts))
889 return -ENOENT;
890
891 return SOF_TIMESTAMPING_TX_HARDWARE;
892 }
893
894 /*
895 * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
896 */
__sock_recv_timestamp(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)897 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
898 struct sk_buff *skb)
899 {
900 int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
901 int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
902 struct scm_timestamping_internal tss;
903 int empty = 1, false_tstamp = 0;
904 struct skb_shared_hwtstamps *shhwtstamps =
905 skb_hwtstamps(skb);
906 int if_index;
907 ktime_t hwtstamp;
908 u32 tsflags;
909
910 /* Race occurred between timestamp enabling and packet
911 receiving. Fill in the current time for now. */
912 if (need_software_tstamp && skb->tstamp == 0) {
913 __net_timestamp(skb);
914 false_tstamp = 1;
915 }
916
917 if (need_software_tstamp) {
918 if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
919 if (new_tstamp) {
920 struct __kernel_sock_timeval tv;
921
922 skb_get_new_timestamp(skb, &tv);
923 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
924 sizeof(tv), &tv);
925 } else {
926 struct __kernel_old_timeval tv;
927
928 skb_get_timestamp(skb, &tv);
929 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
930 sizeof(tv), &tv);
931 }
932 } else {
933 if (new_tstamp) {
934 struct __kernel_timespec ts;
935
936 skb_get_new_timestampns(skb, &ts);
937 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
938 sizeof(ts), &ts);
939 } else {
940 struct __kernel_old_timespec ts;
941
942 skb_get_timestampns(skb, &ts);
943 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
944 sizeof(ts), &ts);
945 }
946 }
947 }
948
949 memset(&tss, 0, sizeof(tss));
950 tsflags = READ_ONCE(sk->sk_tsflags);
951 if ((tsflags & SOF_TIMESTAMPING_SOFTWARE &&
952 (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE ||
953 skb_is_err_queue(skb) ||
954 !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))) &&
955 ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0))
956 empty = 0;
957 if (shhwtstamps &&
958 (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE &&
959 (tsflags & SOF_TIMESTAMPING_RX_HARDWARE ||
960 skb_is_err_queue(skb) ||
961 !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))) &&
962 !skb_is_swtx_tstamp(skb, false_tstamp)) {
963 if_index = 0;
964 if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV)
965 hwtstamp = get_timestamp(sk, skb, &if_index);
966 else
967 hwtstamp = shhwtstamps->hwtstamp;
968
969 if (tsflags & SOF_TIMESTAMPING_BIND_PHC)
970 hwtstamp = ptp_convert_timestamp(&hwtstamp,
971 READ_ONCE(sk->sk_bind_phc));
972
973 if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) {
974 empty = 0;
975
976 if ((tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&
977 !skb_is_err_queue(skb))
978 put_ts_pktinfo(msg, skb, if_index);
979 }
980 }
981 if (!empty) {
982 if (sock_flag(sk, SOCK_TSTAMP_NEW))
983 put_cmsg_scm_timestamping64(msg, &tss);
984 else
985 put_cmsg_scm_timestamping(msg, &tss);
986
987 if (skb_is_err_queue(skb) && skb->len &&
988 SKB_EXT_ERR(skb)->opt_stats)
989 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_OPT_STATS,
990 skb->len, skb->data);
991 }
992 }
993 EXPORT_SYMBOL_GPL(__sock_recv_timestamp);
994
995 #ifdef CONFIG_WIRELESS
__sock_recv_wifi_status(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)996 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
997 struct sk_buff *skb)
998 {
999 int ack;
1000
1001 if (!sock_flag(sk, SOCK_WIFI_STATUS))
1002 return;
1003 if (!skb->wifi_acked_valid)
1004 return;
1005
1006 ack = skb->wifi_acked;
1007
1008 put_cmsg(msg, SOL_SOCKET, SCM_WIFI_STATUS, sizeof(ack), &ack);
1009 }
1010 EXPORT_SYMBOL_GPL(__sock_recv_wifi_status);
1011 #endif
1012
sock_recv_drops(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)1013 static inline void sock_recv_drops(struct msghdr *msg, struct sock *sk,
1014 struct sk_buff *skb)
1015 {
1016 if (sock_flag(sk, SOCK_RXQ_OVFL) && skb && SOCK_SKB_CB(skb)->dropcount)
1017 put_cmsg(msg, SOL_SOCKET, SO_RXQ_OVFL,
1018 sizeof(__u32), &SOCK_SKB_CB(skb)->dropcount);
1019 }
1020
sock_recv_mark(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)1021 static void sock_recv_mark(struct msghdr *msg, struct sock *sk,
1022 struct sk_buff *skb)
1023 {
1024 if (sock_flag(sk, SOCK_RCVMARK) && skb) {
1025 /* We must use a bounce buffer for CONFIG_HARDENED_USERCOPY=y */
1026 __u32 mark = skb->mark;
1027
1028 put_cmsg(msg, SOL_SOCKET, SO_MARK, sizeof(__u32), &mark);
1029 }
1030 }
1031
sock_recv_priority(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)1032 static void sock_recv_priority(struct msghdr *msg, struct sock *sk,
1033 struct sk_buff *skb)
1034 {
1035 if (sock_flag(sk, SOCK_RCVPRIORITY) && skb) {
1036 __u32 priority = skb->priority;
1037
1038 put_cmsg(msg, SOL_SOCKET, SO_PRIORITY, sizeof(__u32), &priority);
1039 }
1040 }
1041
__sock_recv_cmsgs(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)1042 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
1043 struct sk_buff *skb)
1044 {
1045 sock_recv_timestamp(msg, sk, skb);
1046 sock_recv_drops(msg, sk, skb);
1047 sock_recv_mark(msg, sk, skb);
1048 sock_recv_priority(msg, sk, skb);
1049 }
1050 EXPORT_SYMBOL_GPL(__sock_recv_cmsgs);
1051
1052 INDIRECT_CALLABLE_DECLARE(int inet_recvmsg(struct socket *, struct msghdr *,
1053 size_t, int));
1054 INDIRECT_CALLABLE_DECLARE(int inet6_recvmsg(struct socket *, struct msghdr *,
1055 size_t, int));
1056
call_trace_sock_recv_length(struct sock * sk,int ret,int flags)1057 static noinline void call_trace_sock_recv_length(struct sock *sk, int ret, int flags)
1058 {
1059 trace_sock_recv_length(sk, ret, flags);
1060 }
1061
sock_recvmsg_nosec(struct socket * sock,struct msghdr * msg,int flags)1062 static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
1063 int flags)
1064 {
1065 int ret = INDIRECT_CALL_INET(READ_ONCE(sock->ops)->recvmsg,
1066 inet6_recvmsg,
1067 inet_recvmsg, sock, msg,
1068 msg_data_left(msg), flags);
1069 if (trace_sock_recv_length_enabled())
1070 call_trace_sock_recv_length(sock->sk, ret, flags);
1071 return ret;
1072 }
1073
1074 /**
1075 * sock_recvmsg - receive a message from @sock
1076 * @sock: socket
1077 * @msg: message to receive
1078 * @flags: message flags
1079 *
1080 * Receives @msg from @sock, passing through LSM. Returns the total number
1081 * of bytes received, or an error.
1082 */
sock_recvmsg(struct socket * sock,struct msghdr * msg,int flags)1083 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
1084 {
1085 int err = security_socket_recvmsg(sock, msg, msg_data_left(msg), flags);
1086
1087 return err ?: sock_recvmsg_nosec(sock, msg, flags);
1088 }
1089 EXPORT_SYMBOL(sock_recvmsg);
1090
1091 /**
1092 * kernel_recvmsg - Receive a message from a socket (kernel space)
1093 * @sock: The socket to receive the message from
1094 * @msg: Received message
1095 * @vec: Input s/g array for message data
1096 * @num: Size of input s/g array
1097 * @size: Number of bytes to read
1098 * @flags: Message flags (MSG_DONTWAIT, etc...)
1099 *
1100 * On return the msg structure contains the scatter/gather array passed in the
1101 * vec argument. The array is modified so that it consists of the unfilled
1102 * portion of the original array.
1103 *
1104 * The returned value is the total number of bytes received, or an error.
1105 */
1106
kernel_recvmsg(struct socket * sock,struct msghdr * msg,struct kvec * vec,size_t num,size_t size,int flags)1107 int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
1108 struct kvec *vec, size_t num, size_t size, int flags)
1109 {
1110 msg->msg_control_is_user = false;
1111 iov_iter_kvec(&msg->msg_iter, ITER_DEST, vec, num, size);
1112 return sock_recvmsg(sock, msg, flags);
1113 }
1114 EXPORT_SYMBOL(kernel_recvmsg);
1115
sock_splice_read(struct file * file,loff_t * ppos,struct pipe_inode_info * pipe,size_t len,unsigned int flags)1116 static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
1117 struct pipe_inode_info *pipe, size_t len,
1118 unsigned int flags)
1119 {
1120 struct socket *sock = file->private_data;
1121 const struct proto_ops *ops;
1122
1123 ops = READ_ONCE(sock->ops);
1124 if (unlikely(!ops->splice_read))
1125 return copy_splice_read(file, ppos, pipe, len, flags);
1126
1127 return ops->splice_read(sock, ppos, pipe, len, flags);
1128 }
1129
sock_splice_eof(struct file * file)1130 static void sock_splice_eof(struct file *file)
1131 {
1132 struct socket *sock = file->private_data;
1133 const struct proto_ops *ops;
1134
1135 ops = READ_ONCE(sock->ops);
1136 if (ops->splice_eof)
1137 ops->splice_eof(sock);
1138 }
1139
sock_read_iter(struct kiocb * iocb,struct iov_iter * to)1140 static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to)
1141 {
1142 struct file *file = iocb->ki_filp;
1143 struct socket *sock = file->private_data;
1144 struct msghdr msg = {.msg_iter = *to,
1145 .msg_iocb = iocb};
1146 ssize_t res;
1147
1148 if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
1149 msg.msg_flags = MSG_DONTWAIT;
1150
1151 if (iocb->ki_pos != 0)
1152 return -ESPIPE;
1153
1154 if (!iov_iter_count(to)) /* Match SYS5 behaviour */
1155 return 0;
1156
1157 res = sock_recvmsg(sock, &msg, msg.msg_flags);
1158 *to = msg.msg_iter;
1159 return res;
1160 }
1161
sock_write_iter(struct kiocb * iocb,struct iov_iter * from)1162 static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from)
1163 {
1164 struct file *file = iocb->ki_filp;
1165 struct socket *sock = file->private_data;
1166 struct msghdr msg = {.msg_iter = *from,
1167 .msg_iocb = iocb};
1168 ssize_t res;
1169
1170 if (iocb->ki_pos != 0)
1171 return -ESPIPE;
1172
1173 if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
1174 msg.msg_flags = MSG_DONTWAIT;
1175
1176 if (sock->type == SOCK_SEQPACKET)
1177 msg.msg_flags |= MSG_EOR;
1178
1179 res = __sock_sendmsg(sock, &msg);
1180 *from = msg.msg_iter;
1181 return res;
1182 }
1183
1184 /*
1185 * Atomic setting of ioctl hooks to avoid race
1186 * with module unload.
1187 */
1188
1189 static DEFINE_MUTEX(br_ioctl_mutex);
1190 static int (*br_ioctl_hook)(struct net *net, unsigned int cmd,
1191 void __user *uarg);
1192
brioctl_set(int (* hook)(struct net * net,unsigned int cmd,void __user * uarg))1193 void brioctl_set(int (*hook)(struct net *net, unsigned int cmd,
1194 void __user *uarg))
1195 {
1196 mutex_lock(&br_ioctl_mutex);
1197 br_ioctl_hook = hook;
1198 mutex_unlock(&br_ioctl_mutex);
1199 }
1200 EXPORT_SYMBOL(brioctl_set);
1201
br_ioctl_call(struct net * net,unsigned int cmd,void __user * uarg)1202 int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg)
1203 {
1204 int err = -ENOPKG;
1205
1206 if (!br_ioctl_hook)
1207 request_module("bridge");
1208
1209 mutex_lock(&br_ioctl_mutex);
1210 if (br_ioctl_hook)
1211 err = br_ioctl_hook(net, cmd, uarg);
1212 mutex_unlock(&br_ioctl_mutex);
1213
1214 return err;
1215 }
1216
1217 static DEFINE_MUTEX(vlan_ioctl_mutex);
1218 static int (*vlan_ioctl_hook) (struct net *, void __user *arg);
1219
vlan_ioctl_set(int (* hook)(struct net *,void __user *))1220 void vlan_ioctl_set(int (*hook) (struct net *, void __user *))
1221 {
1222 mutex_lock(&vlan_ioctl_mutex);
1223 vlan_ioctl_hook = hook;
1224 mutex_unlock(&vlan_ioctl_mutex);
1225 }
1226 EXPORT_SYMBOL(vlan_ioctl_set);
1227
sock_do_ioctl(struct net * net,struct socket * sock,unsigned int cmd,unsigned long arg)1228 static long sock_do_ioctl(struct net *net, struct socket *sock,
1229 unsigned int cmd, unsigned long arg)
1230 {
1231 const struct proto_ops *ops = READ_ONCE(sock->ops);
1232 struct ifreq ifr;
1233 bool need_copyout;
1234 int err;
1235 void __user *argp = (void __user *)arg;
1236 void __user *data;
1237
1238 err = ops->ioctl(sock, cmd, arg);
1239
1240 /*
1241 * If this ioctl is unknown try to hand it down
1242 * to the NIC driver.
1243 */
1244 if (err != -ENOIOCTLCMD)
1245 return err;
1246
1247 if (!is_socket_ioctl_cmd(cmd))
1248 return -ENOTTY;
1249
1250 if (get_user_ifreq(&ifr, &data, argp))
1251 return -EFAULT;
1252 err = dev_ioctl(net, cmd, &ifr, data, &need_copyout);
1253 if (!err && need_copyout)
1254 if (put_user_ifreq(&ifr, argp))
1255 return -EFAULT;
1256
1257 return err;
1258 }
1259
1260 /*
1261 * With an ioctl, arg may well be a user mode pointer, but we don't know
1262 * what to do with it - that's up to the protocol still.
1263 */
1264
sock_ioctl(struct file * file,unsigned cmd,unsigned long arg)1265 static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
1266 {
1267 const struct proto_ops *ops;
1268 struct socket *sock;
1269 struct sock *sk;
1270 void __user *argp = (void __user *)arg;
1271 int pid, err;
1272 struct net *net;
1273
1274 sock = file->private_data;
1275 ops = READ_ONCE(sock->ops);
1276 sk = sock->sk;
1277 net = sock_net(sk);
1278 if (unlikely(cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))) {
1279 struct ifreq ifr;
1280 void __user *data;
1281 bool need_copyout;
1282 if (get_user_ifreq(&ifr, &data, argp))
1283 return -EFAULT;
1284 err = dev_ioctl(net, cmd, &ifr, data, &need_copyout);
1285 if (!err && need_copyout)
1286 if (put_user_ifreq(&ifr, argp))
1287 return -EFAULT;
1288 } else
1289 #ifdef CONFIG_WEXT_CORE
1290 if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
1291 err = wext_handle_ioctl(net, cmd, argp);
1292 } else
1293 #endif
1294 switch (cmd) {
1295 case FIOSETOWN:
1296 case SIOCSPGRP:
1297 err = -EFAULT;
1298 if (get_user(pid, (int __user *)argp))
1299 break;
1300 err = f_setown(sock->file, pid, 1);
1301 break;
1302 case FIOGETOWN:
1303 case SIOCGPGRP:
1304 err = put_user(f_getown(sock->file),
1305 (int __user *)argp);
1306 break;
1307 case SIOCGIFBR:
1308 case SIOCSIFBR:
1309 case SIOCBRADDBR:
1310 case SIOCBRDELBR:
1311 case SIOCBRADDIF:
1312 case SIOCBRDELIF:
1313 err = br_ioctl_call(net, cmd, argp);
1314 break;
1315 case SIOCGIFVLAN:
1316 case SIOCSIFVLAN:
1317 err = -ENOPKG;
1318 if (!vlan_ioctl_hook)
1319 request_module("8021q");
1320
1321 mutex_lock(&vlan_ioctl_mutex);
1322 if (vlan_ioctl_hook)
1323 err = vlan_ioctl_hook(net, argp);
1324 mutex_unlock(&vlan_ioctl_mutex);
1325 break;
1326 case SIOCGSKNS:
1327 err = -EPERM;
1328 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1329 break;
1330
1331 err = open_related_ns(&net->ns, get_net_ns);
1332 break;
1333 case SIOCGSTAMP_OLD:
1334 case SIOCGSTAMPNS_OLD:
1335 if (!ops->gettstamp) {
1336 err = -ENOIOCTLCMD;
1337 break;
1338 }
1339 err = ops->gettstamp(sock, argp,
1340 cmd == SIOCGSTAMP_OLD,
1341 !IS_ENABLED(CONFIG_64BIT));
1342 break;
1343 case SIOCGSTAMP_NEW:
1344 case SIOCGSTAMPNS_NEW:
1345 if (!ops->gettstamp) {
1346 err = -ENOIOCTLCMD;
1347 break;
1348 }
1349 err = ops->gettstamp(sock, argp,
1350 cmd == SIOCGSTAMP_NEW,
1351 false);
1352 break;
1353
1354 case SIOCGIFCONF:
1355 err = dev_ifconf(net, argp);
1356 break;
1357
1358 default:
1359 err = sock_do_ioctl(net, sock, cmd, arg);
1360 break;
1361 }
1362 return err;
1363 }
1364
1365 /**
1366 * sock_create_lite - creates a socket
1367 * @family: protocol family (AF_INET, ...)
1368 * @type: communication type (SOCK_STREAM, ...)
1369 * @protocol: protocol (0, ...)
1370 * @res: new socket
1371 *
1372 * Creates a new socket and assigns it to @res, passing through LSM.
1373 * The new socket initialization is not complete, see kernel_accept().
1374 * Returns 0 or an error. On failure @res is set to %NULL.
1375 * This function internally uses GFP_KERNEL.
1376 */
1377
sock_create_lite(int family,int type,int protocol,struct socket ** res)1378 int sock_create_lite(int family, int type, int protocol, struct socket **res)
1379 {
1380 int err;
1381 struct socket *sock = NULL;
1382
1383 err = security_socket_create(family, type, protocol, 1);
1384 if (err)
1385 goto out;
1386
1387 sock = sock_alloc();
1388 if (!sock) {
1389 err = -ENOMEM;
1390 goto out;
1391 }
1392
1393 sock->type = type;
1394 err = security_socket_post_create(sock, family, type, protocol, 1);
1395 if (err)
1396 goto out_release;
1397
1398 out:
1399 *res = sock;
1400 return err;
1401 out_release:
1402 sock_release(sock);
1403 sock = NULL;
1404 goto out;
1405 }
1406 EXPORT_SYMBOL(sock_create_lite);
1407
1408 /* No kernel lock held - perfect */
sock_poll(struct file * file,poll_table * wait)1409 static __poll_t sock_poll(struct file *file, poll_table *wait)
1410 {
1411 struct socket *sock = file->private_data;
1412 const struct proto_ops *ops = READ_ONCE(sock->ops);
1413 __poll_t events = poll_requested_events(wait), flag = 0;
1414
1415 if (!ops->poll)
1416 return 0;
1417
1418 if (sk_can_busy_loop(sock->sk)) {
1419 /* poll once if requested by the syscall */
1420 if (events & POLL_BUSY_LOOP)
1421 sk_busy_loop(sock->sk, 1);
1422
1423 /* if this socket can poll_ll, tell the system call */
1424 flag = POLL_BUSY_LOOP;
1425 }
1426
1427 return ops->poll(file, sock, wait) | flag;
1428 }
1429
sock_mmap(struct file * file,struct vm_area_struct * vma)1430 static int sock_mmap(struct file *file, struct vm_area_struct *vma)
1431 {
1432 struct socket *sock = file->private_data;
1433
1434 return READ_ONCE(sock->ops)->mmap(file, sock, vma);
1435 }
1436
sock_close(struct inode * inode,struct file * filp)1437 static int sock_close(struct inode *inode, struct file *filp)
1438 {
1439 __sock_release(SOCKET_I(inode), inode);
1440 return 0;
1441 }
1442
1443 /*
1444 * Update the socket async list
1445 *
1446 * Fasync_list locking strategy.
1447 *
1448 * 1. fasync_list is modified only under process context socket lock
1449 * i.e. under semaphore.
1450 * 2. fasync_list is used under read_lock(&sk->sk_callback_lock)
1451 * or under socket lock
1452 */
1453
sock_fasync(int fd,struct file * filp,int on)1454 static int sock_fasync(int fd, struct file *filp, int on)
1455 {
1456 struct socket *sock = filp->private_data;
1457 struct sock *sk = sock->sk;
1458 struct socket_wq *wq = &sock->wq;
1459
1460 if (sk == NULL)
1461 return -EINVAL;
1462
1463 lock_sock(sk);
1464 fasync_helper(fd, filp, on, &wq->fasync_list);
1465
1466 if (!wq->fasync_list)
1467 sock_reset_flag(sk, SOCK_FASYNC);
1468 else
1469 sock_set_flag(sk, SOCK_FASYNC);
1470
1471 release_sock(sk);
1472 return 0;
1473 }
1474
1475 /* This function may be called only under rcu_lock */
1476
sock_wake_async(struct socket_wq * wq,int how,int band)1477 int sock_wake_async(struct socket_wq *wq, int how, int band)
1478 {
1479 if (!wq || !wq->fasync_list)
1480 return -1;
1481
1482 switch (how) {
1483 case SOCK_WAKE_WAITD:
1484 if (test_bit(SOCKWQ_ASYNC_WAITDATA, &wq->flags))
1485 break;
1486 goto call_kill;
1487 case SOCK_WAKE_SPACE:
1488 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags))
1489 break;
1490 fallthrough;
1491 case SOCK_WAKE_IO:
1492 call_kill:
1493 kill_fasync(&wq->fasync_list, SIGIO, band);
1494 break;
1495 case SOCK_WAKE_URG:
1496 kill_fasync(&wq->fasync_list, SIGURG, band);
1497 }
1498
1499 return 0;
1500 }
1501 EXPORT_SYMBOL(sock_wake_async);
1502
1503 /**
1504 * __sock_create - creates a socket
1505 * @net: net namespace
1506 * @family: protocol family (AF_INET, ...)
1507 * @type: communication type (SOCK_STREAM, ...)
1508 * @protocol: protocol (0, ...)
1509 * @res: new socket
1510 * @kern: boolean for kernel space sockets
1511 *
1512 * Creates a new socket and assigns it to @res, passing through LSM.
1513 * Returns 0 or an error. On failure @res is set to %NULL. @kern must
1514 * be set to true if the socket resides in kernel space.
1515 * This function internally uses GFP_KERNEL.
1516 */
1517
__sock_create(struct net * net,int family,int type,int protocol,struct socket ** res,int kern)1518 int __sock_create(struct net *net, int family, int type, int protocol,
1519 struct socket **res, int kern)
1520 {
1521 int err;
1522 struct socket *sock;
1523 const struct net_proto_family *pf;
1524
1525 /*
1526 * Check protocol is in range
1527 */
1528 if (family < 0 || family >= NPROTO)
1529 return -EAFNOSUPPORT;
1530 if (type < 0 || type >= SOCK_MAX)
1531 return -EINVAL;
1532
1533 /* Compatibility.
1534
1535 This uglymoron is moved from INET layer to here to avoid
1536 deadlock in module load.
1537 */
1538 if (family == PF_INET && type == SOCK_PACKET) {
1539 pr_info_once("%s uses obsolete (PF_INET,SOCK_PACKET)\n",
1540 current->comm);
1541 family = PF_PACKET;
1542 }
1543
1544 err = security_socket_create(family, type, protocol, kern);
1545 if (err)
1546 return err;
1547
1548 /*
1549 * Allocate the socket and allow the family to set things up. if
1550 * the protocol is 0, the family is instructed to select an appropriate
1551 * default.
1552 */
1553 sock = sock_alloc();
1554 if (!sock) {
1555 net_warn_ratelimited("socket: no more sockets\n");
1556 return -ENFILE; /* Not exactly a match, but its the
1557 closest posix thing */
1558 }
1559
1560 sock->type = type;
1561
1562 #ifdef CONFIG_MODULES
1563 /* Attempt to load a protocol module if the find failed.
1564 *
1565 * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user
1566 * requested real, full-featured networking support upon configuration.
1567 * Otherwise module support will break!
1568 */
1569 if (rcu_access_pointer(net_families[family]) == NULL)
1570 request_module("net-pf-%d", family);
1571 #endif
1572
1573 rcu_read_lock();
1574 pf = rcu_dereference(net_families[family]);
1575 err = -EAFNOSUPPORT;
1576 if (!pf)
1577 goto out_release;
1578
1579 /*
1580 * We will call the ->create function, that possibly is in a loadable
1581 * module, so we have to bump that loadable module refcnt first.
1582 */
1583 if (!try_module_get(pf->owner))
1584 goto out_release;
1585
1586 /* Now protected by module ref count */
1587 rcu_read_unlock();
1588
1589 err = pf->create(net, sock, protocol, kern);
1590 if (err < 0) {
1591 /* ->create should release the allocated sock->sk object on error
1592 * and make sure sock->sk is set to NULL to avoid use-after-free
1593 */
1594 DEBUG_NET_WARN_ONCE(sock->sk,
1595 "%ps must clear sock->sk on failure, family: %d, type: %d, protocol: %d\n",
1596 pf->create, family, type, protocol);
1597 goto out_module_put;
1598 }
1599
1600 /*
1601 * Now to bump the refcnt of the [loadable] module that owns this
1602 * socket at sock_release time we decrement its refcnt.
1603 */
1604 if (!try_module_get(sock->ops->owner))
1605 goto out_module_busy;
1606
1607 /*
1608 * Now that we're done with the ->create function, the [loadable]
1609 * module can have its refcnt decremented
1610 */
1611 module_put(pf->owner);
1612 err = security_socket_post_create(sock, family, type, protocol, kern);
1613 if (err)
1614 goto out_sock_release;
1615 *res = sock;
1616
1617 return 0;
1618
1619 out_module_busy:
1620 err = -EAFNOSUPPORT;
1621 out_module_put:
1622 sock->ops = NULL;
1623 module_put(pf->owner);
1624 out_sock_release:
1625 sock_release(sock);
1626 return err;
1627
1628 out_release:
1629 rcu_read_unlock();
1630 goto out_sock_release;
1631 }
1632 EXPORT_SYMBOL(__sock_create);
1633
1634 /**
1635 * sock_create - creates a socket
1636 * @family: protocol family (AF_INET, ...)
1637 * @type: communication type (SOCK_STREAM, ...)
1638 * @protocol: protocol (0, ...)
1639 * @res: new socket
1640 *
1641 * A wrapper around __sock_create().
1642 * Returns 0 or an error. This function internally uses GFP_KERNEL.
1643 */
1644
sock_create(int family,int type,int protocol,struct socket ** res)1645 int sock_create(int family, int type, int protocol, struct socket **res)
1646 {
1647 return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
1648 }
1649 EXPORT_SYMBOL(sock_create);
1650
1651 /**
1652 * sock_create_kern - creates a socket (kernel space)
1653 * @net: net namespace
1654 * @family: protocol family (AF_INET, ...)
1655 * @type: communication type (SOCK_STREAM, ...)
1656 * @protocol: protocol (0, ...)
1657 * @res: new socket
1658 *
1659 * A wrapper around __sock_create().
1660 * Returns 0 or an error. This function internally uses GFP_KERNEL.
1661 */
1662
sock_create_kern(struct net * net,int family,int type,int protocol,struct socket ** res)1663 int sock_create_kern(struct net *net, int family, int type, int protocol, struct socket **res)
1664 {
1665 return __sock_create(net, family, type, protocol, res, 1);
1666 }
1667 EXPORT_SYMBOL(sock_create_kern);
1668
__sys_socket_create(int family,int type,int protocol)1669 static struct socket *__sys_socket_create(int family, int type, int protocol)
1670 {
1671 struct socket *sock;
1672 int retval;
1673
1674 /* Check the SOCK_* constants for consistency. */
1675 BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
1676 BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK);
1677 BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
1678 BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
1679
1680 if ((type & ~SOCK_TYPE_MASK) & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1681 return ERR_PTR(-EINVAL);
1682 type &= SOCK_TYPE_MASK;
1683
1684 retval = sock_create(family, type, protocol, &sock);
1685 if (retval < 0)
1686 return ERR_PTR(retval);
1687
1688 return sock;
1689 }
1690
__sys_socket_file(int family,int type,int protocol)1691 struct file *__sys_socket_file(int family, int type, int protocol)
1692 {
1693 struct socket *sock;
1694 int flags;
1695
1696 sock = __sys_socket_create(family, type, protocol);
1697 if (IS_ERR(sock))
1698 return ERR_CAST(sock);
1699
1700 flags = type & ~SOCK_TYPE_MASK;
1701 if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1702 flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1703
1704 return sock_alloc_file(sock, flags, NULL);
1705 }
1706
1707 /* A hook for bpf progs to attach to and update socket protocol.
1708 *
1709 * A static noinline declaration here could cause the compiler to
1710 * optimize away the function. A global noinline declaration will
1711 * keep the definition, but may optimize away the callsite.
1712 * Therefore, __weak is needed to ensure that the call is still
1713 * emitted, by telling the compiler that we don't know what the
1714 * function might eventually be.
1715 */
1716
1717 __bpf_hook_start();
1718
update_socket_protocol(int family,int type,int protocol)1719 __weak noinline int update_socket_protocol(int family, int type, int protocol)
1720 {
1721 return protocol;
1722 }
1723
1724 __bpf_hook_end();
1725
__sys_socket(int family,int type,int protocol)1726 int __sys_socket(int family, int type, int protocol)
1727 {
1728 struct socket *sock;
1729 int flags;
1730
1731 sock = __sys_socket_create(family, type,
1732 update_socket_protocol(family, type, protocol));
1733 if (IS_ERR(sock))
1734 return PTR_ERR(sock);
1735
1736 flags = type & ~SOCK_TYPE_MASK;
1737 if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1738 flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1739
1740 return sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
1741 }
1742
SYSCALL_DEFINE3(socket,int,family,int,type,int,protocol)1743 SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
1744 {
1745 return __sys_socket(family, type, protocol);
1746 }
1747
1748 /*
1749 * Create a pair of connected sockets.
1750 */
1751
__sys_socketpair(int family,int type,int protocol,int __user * usockvec)1752 int __sys_socketpair(int family, int type, int protocol, int __user *usockvec)
1753 {
1754 struct socket *sock1, *sock2;
1755 int fd1, fd2, err;
1756 struct file *newfile1, *newfile2;
1757 int flags;
1758
1759 flags = type & ~SOCK_TYPE_MASK;
1760 if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1761 return -EINVAL;
1762 type &= SOCK_TYPE_MASK;
1763
1764 if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1765 flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1766
1767 /*
1768 * reserve descriptors and make sure we won't fail
1769 * to return them to userland.
1770 */
1771 fd1 = get_unused_fd_flags(flags);
1772 if (unlikely(fd1 < 0))
1773 return fd1;
1774
1775 fd2 = get_unused_fd_flags(flags);
1776 if (unlikely(fd2 < 0)) {
1777 put_unused_fd(fd1);
1778 return fd2;
1779 }
1780
1781 err = put_user(fd1, &usockvec[0]);
1782 if (err)
1783 goto out;
1784
1785 err = put_user(fd2, &usockvec[1]);
1786 if (err)
1787 goto out;
1788
1789 /*
1790 * Obtain the first socket and check if the underlying protocol
1791 * supports the socketpair call.
1792 */
1793
1794 err = sock_create(family, type, protocol, &sock1);
1795 if (unlikely(err < 0))
1796 goto out;
1797
1798 err = sock_create(family, type, protocol, &sock2);
1799 if (unlikely(err < 0)) {
1800 sock_release(sock1);
1801 goto out;
1802 }
1803
1804 err = security_socket_socketpair(sock1, sock2);
1805 if (unlikely(err)) {
1806 sock_release(sock2);
1807 sock_release(sock1);
1808 goto out;
1809 }
1810
1811 err = READ_ONCE(sock1->ops)->socketpair(sock1, sock2);
1812 if (unlikely(err < 0)) {
1813 sock_release(sock2);
1814 sock_release(sock1);
1815 goto out;
1816 }
1817
1818 newfile1 = sock_alloc_file(sock1, flags, NULL);
1819 if (IS_ERR(newfile1)) {
1820 err = PTR_ERR(newfile1);
1821 sock_release(sock2);
1822 goto out;
1823 }
1824
1825 newfile2 = sock_alloc_file(sock2, flags, NULL);
1826 if (IS_ERR(newfile2)) {
1827 err = PTR_ERR(newfile2);
1828 fput(newfile1);
1829 goto out;
1830 }
1831
1832 audit_fd_pair(fd1, fd2);
1833
1834 fd_install(fd1, newfile1);
1835 fd_install(fd2, newfile2);
1836 return 0;
1837
1838 out:
1839 put_unused_fd(fd2);
1840 put_unused_fd(fd1);
1841 return err;
1842 }
1843
SYSCALL_DEFINE4(socketpair,int,family,int,type,int,protocol,int __user *,usockvec)1844 SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol,
1845 int __user *, usockvec)
1846 {
1847 return __sys_socketpair(family, type, protocol, usockvec);
1848 }
1849
__sys_bind_socket(struct socket * sock,struct sockaddr_storage * address,int addrlen)1850 int __sys_bind_socket(struct socket *sock, struct sockaddr_storage *address,
1851 int addrlen)
1852 {
1853 int err;
1854
1855 err = security_socket_bind(sock, (struct sockaddr *)address,
1856 addrlen);
1857 if (!err)
1858 err = READ_ONCE(sock->ops)->bind(sock,
1859 (struct sockaddr *)address,
1860 addrlen);
1861 return err;
1862 }
1863
1864 /*
1865 * Bind a name to a socket. Nothing much to do here since it's
1866 * the protocol's responsibility to handle the local address.
1867 *
1868 * We move the socket address to kernel space before we call
1869 * the protocol layer (having also checked the address is ok).
1870 */
1871
__sys_bind(int fd,struct sockaddr __user * umyaddr,int addrlen)1872 int __sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen)
1873 {
1874 struct socket *sock;
1875 struct sockaddr_storage address;
1876 CLASS(fd, f)(fd);
1877 int err;
1878
1879 if (fd_empty(f))
1880 return -EBADF;
1881 sock = sock_from_file(fd_file(f));
1882 if (unlikely(!sock))
1883 return -ENOTSOCK;
1884
1885 err = move_addr_to_kernel(umyaddr, addrlen, &address);
1886 if (unlikely(err))
1887 return err;
1888
1889 return __sys_bind_socket(sock, &address, addrlen);
1890 }
1891
SYSCALL_DEFINE3(bind,int,fd,struct sockaddr __user *,umyaddr,int,addrlen)1892 SYSCALL_DEFINE3(bind, int, fd, struct sockaddr __user *, umyaddr, int, addrlen)
1893 {
1894 return __sys_bind(fd, umyaddr, addrlen);
1895 }
1896
1897 /*
1898 * Perform a listen. Basically, we allow the protocol to do anything
1899 * necessary for a listen, and if that works, we mark the socket as
1900 * ready for listening.
1901 */
__sys_listen_socket(struct socket * sock,int backlog)1902 int __sys_listen_socket(struct socket *sock, int backlog)
1903 {
1904 int somaxconn, err;
1905
1906 somaxconn = READ_ONCE(sock_net(sock->sk)->core.sysctl_somaxconn);
1907 if ((unsigned int)backlog > somaxconn)
1908 backlog = somaxconn;
1909
1910 err = security_socket_listen(sock, backlog);
1911 if (!err)
1912 err = READ_ONCE(sock->ops)->listen(sock, backlog);
1913 return err;
1914 }
1915
__sys_listen(int fd,int backlog)1916 int __sys_listen(int fd, int backlog)
1917 {
1918 CLASS(fd, f)(fd);
1919 struct socket *sock;
1920
1921 if (fd_empty(f))
1922 return -EBADF;
1923 sock = sock_from_file(fd_file(f));
1924 if (unlikely(!sock))
1925 return -ENOTSOCK;
1926
1927 return __sys_listen_socket(sock, backlog);
1928 }
1929
SYSCALL_DEFINE2(listen,int,fd,int,backlog)1930 SYSCALL_DEFINE2(listen, int, fd, int, backlog)
1931 {
1932 return __sys_listen(fd, backlog);
1933 }
1934
do_accept(struct file * file,struct proto_accept_arg * arg,struct sockaddr __user * upeer_sockaddr,int __user * upeer_addrlen,int flags)1935 struct file *do_accept(struct file *file, struct proto_accept_arg *arg,
1936 struct sockaddr __user *upeer_sockaddr,
1937 int __user *upeer_addrlen, int flags)
1938 {
1939 struct socket *sock, *newsock;
1940 struct file *newfile;
1941 int err, len;
1942 struct sockaddr_storage address;
1943 const struct proto_ops *ops;
1944
1945 sock = sock_from_file(file);
1946 if (!sock)
1947 return ERR_PTR(-ENOTSOCK);
1948
1949 newsock = sock_alloc();
1950 if (!newsock)
1951 return ERR_PTR(-ENFILE);
1952 ops = READ_ONCE(sock->ops);
1953
1954 newsock->type = sock->type;
1955 newsock->ops = ops;
1956
1957 /*
1958 * We don't need try_module_get here, as the listening socket (sock)
1959 * has the protocol module (sock->ops->owner) held.
1960 */
1961 __module_get(ops->owner);
1962
1963 newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name);
1964 if (IS_ERR(newfile))
1965 return newfile;
1966
1967 err = security_socket_accept(sock, newsock);
1968 if (err)
1969 goto out_fd;
1970
1971 arg->flags |= sock->file->f_flags;
1972 err = ops->accept(sock, newsock, arg);
1973 if (err < 0)
1974 goto out_fd;
1975
1976 if (upeer_sockaddr) {
1977 len = ops->getname(newsock, (struct sockaddr *)&address, 2);
1978 if (len < 0) {
1979 err = -ECONNABORTED;
1980 goto out_fd;
1981 }
1982 err = move_addr_to_user(&address,
1983 len, upeer_sockaddr, upeer_addrlen);
1984 if (err < 0)
1985 goto out_fd;
1986 }
1987
1988 /* File flags are not inherited via accept() unlike another OSes. */
1989 return newfile;
1990 out_fd:
1991 fput(newfile);
1992 return ERR_PTR(err);
1993 }
1994
__sys_accept4_file(struct file * file,struct sockaddr __user * upeer_sockaddr,int __user * upeer_addrlen,int flags)1995 static int __sys_accept4_file(struct file *file, struct sockaddr __user *upeer_sockaddr,
1996 int __user *upeer_addrlen, int flags)
1997 {
1998 struct proto_accept_arg arg = { };
1999 struct file *newfile;
2000 int newfd;
2001
2002 if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
2003 return -EINVAL;
2004
2005 if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
2006 flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
2007
2008 newfd = get_unused_fd_flags(flags);
2009 if (unlikely(newfd < 0))
2010 return newfd;
2011
2012 newfile = do_accept(file, &arg, upeer_sockaddr, upeer_addrlen,
2013 flags);
2014 if (IS_ERR(newfile)) {
2015 put_unused_fd(newfd);
2016 return PTR_ERR(newfile);
2017 }
2018 fd_install(newfd, newfile);
2019 return newfd;
2020 }
2021
2022 /*
2023 * For accept, we attempt to create a new socket, set up the link
2024 * with the client, wake up the client, then return the new
2025 * connected fd. We collect the address of the connector in kernel
2026 * space and move it to user at the very end. This is unclean because
2027 * we open the socket then return an error.
2028 *
2029 * 1003.1g adds the ability to recvmsg() to query connection pending
2030 * status to recvmsg. We need to add that support in a way thats
2031 * clean when we restructure accept also.
2032 */
2033
__sys_accept4(int fd,struct sockaddr __user * upeer_sockaddr,int __user * upeer_addrlen,int flags)2034 int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
2035 int __user *upeer_addrlen, int flags)
2036 {
2037 CLASS(fd, f)(fd);
2038
2039 if (fd_empty(f))
2040 return -EBADF;
2041 return __sys_accept4_file(fd_file(f), upeer_sockaddr,
2042 upeer_addrlen, flags);
2043 }
2044
SYSCALL_DEFINE4(accept4,int,fd,struct sockaddr __user *,upeer_sockaddr,int __user *,upeer_addrlen,int,flags)2045 SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
2046 int __user *, upeer_addrlen, int, flags)
2047 {
2048 return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, flags);
2049 }
2050
SYSCALL_DEFINE3(accept,int,fd,struct sockaddr __user *,upeer_sockaddr,int __user *,upeer_addrlen)2051 SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr,
2052 int __user *, upeer_addrlen)
2053 {
2054 return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0);
2055 }
2056
2057 /*
2058 * Attempt to connect to a socket with the server address. The address
2059 * is in user space so we verify it is OK and move it to kernel space.
2060 *
2061 * For 1003.1g we need to add clean support for a bind to AF_UNSPEC to
2062 * break bindings
2063 *
2064 * NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and
2065 * other SEQPACKET protocols that take time to connect() as it doesn't
2066 * include the -EINPROGRESS status for such sockets.
2067 */
2068
__sys_connect_file(struct file * file,struct sockaddr_storage * address,int addrlen,int file_flags)2069 int __sys_connect_file(struct file *file, struct sockaddr_storage *address,
2070 int addrlen, int file_flags)
2071 {
2072 struct socket *sock;
2073 int err;
2074
2075 sock = sock_from_file(file);
2076 if (!sock) {
2077 err = -ENOTSOCK;
2078 goto out;
2079 }
2080
2081 err =
2082 security_socket_connect(sock, (struct sockaddr *)address, addrlen);
2083 if (err)
2084 goto out;
2085
2086 err = READ_ONCE(sock->ops)->connect(sock, (struct sockaddr *)address,
2087 addrlen, sock->file->f_flags | file_flags);
2088 out:
2089 return err;
2090 }
2091
__sys_connect(int fd,struct sockaddr __user * uservaddr,int addrlen)2092 int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
2093 {
2094 struct sockaddr_storage address;
2095 CLASS(fd, f)(fd);
2096 int ret;
2097
2098 if (fd_empty(f))
2099 return -EBADF;
2100
2101 ret = move_addr_to_kernel(uservaddr, addrlen, &address);
2102 if (ret)
2103 return ret;
2104
2105 return __sys_connect_file(fd_file(f), &address, addrlen, 0);
2106 }
2107
SYSCALL_DEFINE3(connect,int,fd,struct sockaddr __user *,uservaddr,int,addrlen)2108 SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
2109 int, addrlen)
2110 {
2111 return __sys_connect(fd, uservaddr, addrlen);
2112 }
2113
2114 /*
2115 * Get the local address ('name') of a socket object. Move the obtained
2116 * name to user space.
2117 */
2118
__sys_getsockname(int fd,struct sockaddr __user * usockaddr,int __user * usockaddr_len)2119 int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
2120 int __user *usockaddr_len)
2121 {
2122 struct socket *sock;
2123 struct sockaddr_storage address;
2124 CLASS(fd, f)(fd);
2125 int err;
2126
2127 if (fd_empty(f))
2128 return -EBADF;
2129 sock = sock_from_file(fd_file(f));
2130 if (unlikely(!sock))
2131 return -ENOTSOCK;
2132
2133 err = security_socket_getsockname(sock);
2134 if (err)
2135 return err;
2136
2137 err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 0);
2138 if (err < 0)
2139 return err;
2140
2141 /* "err" is actually length in this case */
2142 return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
2143 }
2144
SYSCALL_DEFINE3(getsockname,int,fd,struct sockaddr __user *,usockaddr,int __user *,usockaddr_len)2145 SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
2146 int __user *, usockaddr_len)
2147 {
2148 return __sys_getsockname(fd, usockaddr, usockaddr_len);
2149 }
2150
2151 /*
2152 * Get the remote address ('name') of a socket object. Move the obtained
2153 * name to user space.
2154 */
2155
__sys_getpeername(int fd,struct sockaddr __user * usockaddr,int __user * usockaddr_len)2156 int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
2157 int __user *usockaddr_len)
2158 {
2159 struct socket *sock;
2160 struct sockaddr_storage address;
2161 CLASS(fd, f)(fd);
2162 int err;
2163
2164 if (fd_empty(f))
2165 return -EBADF;
2166 sock = sock_from_file(fd_file(f));
2167 if (unlikely(!sock))
2168 return -ENOTSOCK;
2169
2170 err = security_socket_getpeername(sock);
2171 if (err)
2172 return err;
2173
2174 err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 1);
2175 if (err < 0)
2176 return err;
2177
2178 /* "err" is actually length in this case */
2179 return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
2180 }
2181
SYSCALL_DEFINE3(getpeername,int,fd,struct sockaddr __user *,usockaddr,int __user *,usockaddr_len)2182 SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
2183 int __user *, usockaddr_len)
2184 {
2185 return __sys_getpeername(fd, usockaddr, usockaddr_len);
2186 }
2187
2188 /*
2189 * Send a datagram to a given address. We move the address into kernel
2190 * space and check the user space data area is readable before invoking
2191 * the protocol.
2192 */
__sys_sendto(int fd,void __user * buff,size_t len,unsigned int flags,struct sockaddr __user * addr,int addr_len)2193 int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags,
2194 struct sockaddr __user *addr, int addr_len)
2195 {
2196 struct socket *sock;
2197 struct sockaddr_storage address;
2198 int err;
2199 struct msghdr msg;
2200
2201 err = import_ubuf(ITER_SOURCE, buff, len, &msg.msg_iter);
2202 if (unlikely(err))
2203 return err;
2204
2205 CLASS(fd, f)(fd);
2206 if (fd_empty(f))
2207 return -EBADF;
2208 sock = sock_from_file(fd_file(f));
2209 if (unlikely(!sock))
2210 return -ENOTSOCK;
2211
2212 msg.msg_name = NULL;
2213 msg.msg_control = NULL;
2214 msg.msg_controllen = 0;
2215 msg.msg_namelen = 0;
2216 msg.msg_ubuf = NULL;
2217 if (addr) {
2218 err = move_addr_to_kernel(addr, addr_len, &address);
2219 if (err < 0)
2220 return err;
2221 msg.msg_name = (struct sockaddr *)&address;
2222 msg.msg_namelen = addr_len;
2223 }
2224 flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
2225 if (sock->file->f_flags & O_NONBLOCK)
2226 flags |= MSG_DONTWAIT;
2227 msg.msg_flags = flags;
2228 return __sock_sendmsg(sock, &msg);
2229 }
2230
SYSCALL_DEFINE6(sendto,int,fd,void __user *,buff,size_t,len,unsigned int,flags,struct sockaddr __user *,addr,int,addr_len)2231 SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
2232 unsigned int, flags, struct sockaddr __user *, addr,
2233 int, addr_len)
2234 {
2235 return __sys_sendto(fd, buff, len, flags, addr, addr_len);
2236 }
2237
2238 /*
2239 * Send a datagram down a socket.
2240 */
2241
SYSCALL_DEFINE4(send,int,fd,void __user *,buff,size_t,len,unsigned int,flags)2242 SYSCALL_DEFINE4(send, int, fd, void __user *, buff, size_t, len,
2243 unsigned int, flags)
2244 {
2245 return __sys_sendto(fd, buff, len, flags, NULL, 0);
2246 }
2247
2248 /*
2249 * Receive a frame from the socket and optionally record the address of the
2250 * sender. We verify the buffers are writable and if needed move the
2251 * sender address from kernel to user space.
2252 */
__sys_recvfrom(int fd,void __user * ubuf,size_t size,unsigned int flags,struct sockaddr __user * addr,int __user * addr_len)2253 int __sys_recvfrom(int fd, void __user *ubuf, size_t size, unsigned int flags,
2254 struct sockaddr __user *addr, int __user *addr_len)
2255 {
2256 struct sockaddr_storage address;
2257 struct msghdr msg = {
2258 /* Save some cycles and don't copy the address if not needed */
2259 .msg_name = addr ? (struct sockaddr *)&address : NULL,
2260 };
2261 struct socket *sock;
2262 int err, err2;
2263
2264 err = import_ubuf(ITER_DEST, ubuf, size, &msg.msg_iter);
2265 if (unlikely(err))
2266 return err;
2267
2268 CLASS(fd, f)(fd);
2269
2270 if (fd_empty(f))
2271 return -EBADF;
2272 sock = sock_from_file(fd_file(f));
2273 if (unlikely(!sock))
2274 return -ENOTSOCK;
2275
2276 if (sock->file->f_flags & O_NONBLOCK)
2277 flags |= MSG_DONTWAIT;
2278 err = sock_recvmsg(sock, &msg, flags);
2279
2280 if (err >= 0 && addr != NULL) {
2281 err2 = move_addr_to_user(&address,
2282 msg.msg_namelen, addr, addr_len);
2283 if (err2 < 0)
2284 err = err2;
2285 }
2286 return err;
2287 }
2288
SYSCALL_DEFINE6(recvfrom,int,fd,void __user *,ubuf,size_t,size,unsigned int,flags,struct sockaddr __user *,addr,int __user *,addr_len)2289 SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
2290 unsigned int, flags, struct sockaddr __user *, addr,
2291 int __user *, addr_len)
2292 {
2293 return __sys_recvfrom(fd, ubuf, size, flags, addr, addr_len);
2294 }
2295
2296 /*
2297 * Receive a datagram from a socket.
2298 */
2299
SYSCALL_DEFINE4(recv,int,fd,void __user *,ubuf,size_t,size,unsigned int,flags)2300 SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size,
2301 unsigned int, flags)
2302 {
2303 return __sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
2304 }
2305
sock_use_custom_sol_socket(const struct socket * sock)2306 static bool sock_use_custom_sol_socket(const struct socket *sock)
2307 {
2308 return test_bit(SOCK_CUSTOM_SOCKOPT, &sock->flags);
2309 }
2310
do_sock_setsockopt(struct socket * sock,bool compat,int level,int optname,sockptr_t optval,int optlen)2311 int do_sock_setsockopt(struct socket *sock, bool compat, int level,
2312 int optname, sockptr_t optval, int optlen)
2313 {
2314 const struct proto_ops *ops;
2315 char *kernel_optval = NULL;
2316 int err;
2317
2318 if (optlen < 0)
2319 return -EINVAL;
2320
2321 err = security_socket_setsockopt(sock, level, optname);
2322 if (err)
2323 goto out_put;
2324
2325 if (!compat)
2326 err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level, &optname,
2327 optval, &optlen,
2328 &kernel_optval);
2329 if (err < 0)
2330 goto out_put;
2331 if (err > 0) {
2332 err = 0;
2333 goto out_put;
2334 }
2335
2336 if (kernel_optval)
2337 optval = KERNEL_SOCKPTR(kernel_optval);
2338 ops = READ_ONCE(sock->ops);
2339 if (level == SOL_SOCKET && !sock_use_custom_sol_socket(sock))
2340 err = sock_setsockopt(sock, level, optname, optval, optlen);
2341 else if (unlikely(!ops->setsockopt))
2342 err = -EOPNOTSUPP;
2343 else
2344 err = ops->setsockopt(sock, level, optname, optval,
2345 optlen);
2346 kfree(kernel_optval);
2347 out_put:
2348 return err;
2349 }
2350 EXPORT_SYMBOL(do_sock_setsockopt);
2351
2352 /* Set a socket option. Because we don't know the option lengths we have
2353 * to pass the user mode parameter for the protocols to sort out.
2354 */
__sys_setsockopt(int fd,int level,int optname,char __user * user_optval,int optlen)2355 int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
2356 int optlen)
2357 {
2358 sockptr_t optval = USER_SOCKPTR(user_optval);
2359 bool compat = in_compat_syscall();
2360 struct socket *sock;
2361 CLASS(fd, f)(fd);
2362
2363 if (fd_empty(f))
2364 return -EBADF;
2365 sock = sock_from_file(fd_file(f));
2366 if (unlikely(!sock))
2367 return -ENOTSOCK;
2368
2369 return do_sock_setsockopt(sock, compat, level, optname, optval, optlen);
2370 }
2371
SYSCALL_DEFINE5(setsockopt,int,fd,int,level,int,optname,char __user *,optval,int,optlen)2372 SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
2373 char __user *, optval, int, optlen)
2374 {
2375 return __sys_setsockopt(fd, level, optname, optval, optlen);
2376 }
2377
2378 INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level,
2379 int optname));
2380
do_sock_getsockopt(struct socket * sock,bool compat,int level,int optname,sockptr_t optval,sockptr_t optlen)2381 int do_sock_getsockopt(struct socket *sock, bool compat, int level,
2382 int optname, sockptr_t optval, sockptr_t optlen)
2383 {
2384 int max_optlen __maybe_unused = 0;
2385 const struct proto_ops *ops;
2386 int err;
2387
2388 err = security_socket_getsockopt(sock, level, optname);
2389 if (err)
2390 return err;
2391
2392 if (!compat)
2393 copy_from_sockptr(&max_optlen, optlen, sizeof(int));
2394
2395 ops = READ_ONCE(sock->ops);
2396 if (level == SOL_SOCKET) {
2397 err = sk_getsockopt(sock->sk, level, optname, optval, optlen);
2398 } else if (unlikely(!ops->getsockopt)) {
2399 err = -EOPNOTSUPP;
2400 } else {
2401 if (WARN_ONCE(optval.is_kernel || optlen.is_kernel,
2402 "Invalid argument type"))
2403 return -EOPNOTSUPP;
2404
2405 err = ops->getsockopt(sock, level, optname, optval.user,
2406 optlen.user);
2407 }
2408
2409 if (!compat)
2410 err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,
2411 optval, optlen, max_optlen,
2412 err);
2413
2414 return err;
2415 }
2416 EXPORT_SYMBOL(do_sock_getsockopt);
2417
2418 /*
2419 * Get a socket option. Because we don't know the option lengths we have
2420 * to pass a user mode parameter for the protocols to sort out.
2421 */
__sys_getsockopt(int fd,int level,int optname,char __user * optval,int __user * optlen)2422 int __sys_getsockopt(int fd, int level, int optname, char __user *optval,
2423 int __user *optlen)
2424 {
2425 struct socket *sock;
2426 CLASS(fd, f)(fd);
2427
2428 if (fd_empty(f))
2429 return -EBADF;
2430 sock = sock_from_file(fd_file(f));
2431 if (unlikely(!sock))
2432 return -ENOTSOCK;
2433
2434 return do_sock_getsockopt(sock, in_compat_syscall(), level, optname,
2435 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
2436 }
2437
SYSCALL_DEFINE5(getsockopt,int,fd,int,level,int,optname,char __user *,optval,int __user *,optlen)2438 SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
2439 char __user *, optval, int __user *, optlen)
2440 {
2441 return __sys_getsockopt(fd, level, optname, optval, optlen);
2442 }
2443
2444 /*
2445 * Shutdown a socket.
2446 */
2447
__sys_shutdown_sock(struct socket * sock,int how)2448 int __sys_shutdown_sock(struct socket *sock, int how)
2449 {
2450 int err;
2451
2452 err = security_socket_shutdown(sock, how);
2453 if (!err)
2454 err = READ_ONCE(sock->ops)->shutdown(sock, how);
2455
2456 return err;
2457 }
2458
__sys_shutdown(int fd,int how)2459 int __sys_shutdown(int fd, int how)
2460 {
2461 struct socket *sock;
2462 CLASS(fd, f)(fd);
2463
2464 if (fd_empty(f))
2465 return -EBADF;
2466 sock = sock_from_file(fd_file(f));
2467 if (unlikely(!sock))
2468 return -ENOTSOCK;
2469
2470 return __sys_shutdown_sock(sock, how);
2471 }
2472
SYSCALL_DEFINE2(shutdown,int,fd,int,how)2473 SYSCALL_DEFINE2(shutdown, int, fd, int, how)
2474 {
2475 return __sys_shutdown(fd, how);
2476 }
2477
2478 /* A couple of helpful macros for getting the address of the 32/64 bit
2479 * fields which are the same type (int / unsigned) on our platforms.
2480 */
2481 #define COMPAT_MSG(msg, member) ((MSG_CMSG_COMPAT & flags) ? &msg##_compat->member : &msg->member)
2482 #define COMPAT_NAMELEN(msg) COMPAT_MSG(msg, msg_namelen)
2483 #define COMPAT_FLAGS(msg) COMPAT_MSG(msg, msg_flags)
2484
2485 struct used_address {
2486 struct sockaddr_storage name;
2487 unsigned int name_len;
2488 };
2489
__copy_msghdr(struct msghdr * kmsg,struct user_msghdr * msg,struct sockaddr __user ** save_addr)2490 int __copy_msghdr(struct msghdr *kmsg,
2491 struct user_msghdr *msg,
2492 struct sockaddr __user **save_addr)
2493 {
2494 ssize_t err;
2495
2496 kmsg->msg_control_is_user = true;
2497 kmsg->msg_get_inq = 0;
2498 kmsg->msg_control_user = msg->msg_control;
2499 kmsg->msg_controllen = msg->msg_controllen;
2500 kmsg->msg_flags = msg->msg_flags;
2501
2502 kmsg->msg_namelen = msg->msg_namelen;
2503 if (!msg->msg_name)
2504 kmsg->msg_namelen = 0;
2505
2506 if (kmsg->msg_namelen < 0)
2507 return -EINVAL;
2508
2509 if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
2510 kmsg->msg_namelen = sizeof(struct sockaddr_storage);
2511
2512 if (save_addr)
2513 *save_addr = msg->msg_name;
2514
2515 if (msg->msg_name && kmsg->msg_namelen) {
2516 if (!save_addr) {
2517 err = move_addr_to_kernel(msg->msg_name,
2518 kmsg->msg_namelen,
2519 kmsg->msg_name);
2520 if (err < 0)
2521 return err;
2522 }
2523 } else {
2524 kmsg->msg_name = NULL;
2525 kmsg->msg_namelen = 0;
2526 }
2527
2528 if (msg->msg_iovlen > UIO_MAXIOV)
2529 return -EMSGSIZE;
2530
2531 kmsg->msg_iocb = NULL;
2532 kmsg->msg_ubuf = NULL;
2533 return 0;
2534 }
2535
copy_msghdr_from_user(struct msghdr * kmsg,struct user_msghdr __user * umsg,struct sockaddr __user ** save_addr,struct iovec ** iov)2536 static int copy_msghdr_from_user(struct msghdr *kmsg,
2537 struct user_msghdr __user *umsg,
2538 struct sockaddr __user **save_addr,
2539 struct iovec **iov)
2540 {
2541 struct user_msghdr msg;
2542 ssize_t err;
2543
2544 if (copy_from_user(&msg, umsg, sizeof(*umsg)))
2545 return -EFAULT;
2546
2547 err = __copy_msghdr(kmsg, &msg, save_addr);
2548 if (err)
2549 return err;
2550
2551 err = import_iovec(save_addr ? ITER_DEST : ITER_SOURCE,
2552 msg.msg_iov, msg.msg_iovlen,
2553 UIO_FASTIOV, iov, &kmsg->msg_iter);
2554 return err < 0 ? err : 0;
2555 }
2556
____sys_sendmsg(struct socket * sock,struct msghdr * msg_sys,unsigned int flags,struct used_address * used_address,unsigned int allowed_msghdr_flags)2557 static int ____sys_sendmsg(struct socket *sock, struct msghdr *msg_sys,
2558 unsigned int flags, struct used_address *used_address,
2559 unsigned int allowed_msghdr_flags)
2560 {
2561 unsigned char ctl[sizeof(struct cmsghdr) + 20]
2562 __aligned(sizeof(__kernel_size_t));
2563 /* 20 is size of ipv6_pktinfo */
2564 unsigned char *ctl_buf = ctl;
2565 int ctl_len;
2566 ssize_t err;
2567
2568 err = -ENOBUFS;
2569
2570 if (msg_sys->msg_controllen > INT_MAX)
2571 goto out;
2572 flags |= (msg_sys->msg_flags & allowed_msghdr_flags);
2573 ctl_len = msg_sys->msg_controllen;
2574 if ((MSG_CMSG_COMPAT & flags) && ctl_len) {
2575 err =
2576 cmsghdr_from_user_compat_to_kern(msg_sys, sock->sk, ctl,
2577 sizeof(ctl));
2578 if (err)
2579 goto out;
2580 ctl_buf = msg_sys->msg_control;
2581 ctl_len = msg_sys->msg_controllen;
2582 } else if (ctl_len) {
2583 BUILD_BUG_ON(sizeof(struct cmsghdr) !=
2584 CMSG_ALIGN(sizeof(struct cmsghdr)));
2585 if (ctl_len > sizeof(ctl)) {
2586 ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
2587 if (ctl_buf == NULL)
2588 goto out;
2589 }
2590 err = -EFAULT;
2591 if (copy_from_user(ctl_buf, msg_sys->msg_control_user, ctl_len))
2592 goto out_freectl;
2593 msg_sys->msg_control = ctl_buf;
2594 msg_sys->msg_control_is_user = false;
2595 }
2596 flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
2597 msg_sys->msg_flags = flags;
2598
2599 if (sock->file->f_flags & O_NONBLOCK)
2600 msg_sys->msg_flags |= MSG_DONTWAIT;
2601 /*
2602 * If this is sendmmsg() and current destination address is same as
2603 * previously succeeded address, omit asking LSM's decision.
2604 * used_address->name_len is initialized to UINT_MAX so that the first
2605 * destination address never matches.
2606 */
2607 if (used_address && msg_sys->msg_name &&
2608 used_address->name_len == msg_sys->msg_namelen &&
2609 !memcmp(&used_address->name, msg_sys->msg_name,
2610 used_address->name_len)) {
2611 err = sock_sendmsg_nosec(sock, msg_sys);
2612 goto out_freectl;
2613 }
2614 err = __sock_sendmsg(sock, msg_sys);
2615 /*
2616 * If this is sendmmsg() and sending to current destination address was
2617 * successful, remember it.
2618 */
2619 if (used_address && err >= 0) {
2620 used_address->name_len = msg_sys->msg_namelen;
2621 if (msg_sys->msg_name)
2622 memcpy(&used_address->name, msg_sys->msg_name,
2623 used_address->name_len);
2624 }
2625
2626 out_freectl:
2627 if (ctl_buf != ctl)
2628 sock_kfree_s(sock->sk, ctl_buf, ctl_len);
2629 out:
2630 return err;
2631 }
2632
sendmsg_copy_msghdr(struct msghdr * msg,struct user_msghdr __user * umsg,unsigned flags,struct iovec ** iov)2633 static int sendmsg_copy_msghdr(struct msghdr *msg,
2634 struct user_msghdr __user *umsg, unsigned flags,
2635 struct iovec **iov)
2636 {
2637 int err;
2638
2639 if (flags & MSG_CMSG_COMPAT) {
2640 struct compat_msghdr __user *msg_compat;
2641
2642 msg_compat = (struct compat_msghdr __user *) umsg;
2643 err = get_compat_msghdr(msg, msg_compat, NULL, iov);
2644 } else {
2645 err = copy_msghdr_from_user(msg, umsg, NULL, iov);
2646 }
2647 if (err < 0)
2648 return err;
2649
2650 return 0;
2651 }
2652
___sys_sendmsg(struct socket * sock,struct user_msghdr __user * msg,struct msghdr * msg_sys,unsigned int flags,struct used_address * used_address,unsigned int allowed_msghdr_flags)2653 static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
2654 struct msghdr *msg_sys, unsigned int flags,
2655 struct used_address *used_address,
2656 unsigned int allowed_msghdr_flags)
2657 {
2658 struct sockaddr_storage address;
2659 struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
2660 ssize_t err;
2661
2662 msg_sys->msg_name = &address;
2663
2664 err = sendmsg_copy_msghdr(msg_sys, msg, flags, &iov);
2665 if (err < 0)
2666 return err;
2667
2668 err = ____sys_sendmsg(sock, msg_sys, flags, used_address,
2669 allowed_msghdr_flags);
2670 kfree(iov);
2671 return err;
2672 }
2673
2674 /*
2675 * BSD sendmsg interface
2676 */
__sys_sendmsg_sock(struct socket * sock,struct msghdr * msg,unsigned int flags)2677 long __sys_sendmsg_sock(struct socket *sock, struct msghdr *msg,
2678 unsigned int flags)
2679 {
2680 return ____sys_sendmsg(sock, msg, flags, NULL, 0);
2681 }
2682
__sys_sendmsg(int fd,struct user_msghdr __user * msg,unsigned int flags,bool forbid_cmsg_compat)2683 long __sys_sendmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
2684 bool forbid_cmsg_compat)
2685 {
2686 struct msghdr msg_sys;
2687 struct socket *sock;
2688
2689 if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
2690 return -EINVAL;
2691
2692 CLASS(fd, f)(fd);
2693
2694 if (fd_empty(f))
2695 return -EBADF;
2696 sock = sock_from_file(fd_file(f));
2697 if (unlikely(!sock))
2698 return -ENOTSOCK;
2699
2700 return ___sys_sendmsg(sock, msg, &msg_sys, flags, NULL, 0);
2701 }
2702
SYSCALL_DEFINE3(sendmsg,int,fd,struct user_msghdr __user *,msg,unsigned int,flags)2703 SYSCALL_DEFINE3(sendmsg, int, fd, struct user_msghdr __user *, msg, unsigned int, flags)
2704 {
2705 return __sys_sendmsg(fd, msg, flags, true);
2706 }
2707
2708 /*
2709 * Linux sendmmsg interface
2710 */
2711
__sys_sendmmsg(int fd,struct mmsghdr __user * mmsg,unsigned int vlen,unsigned int flags,bool forbid_cmsg_compat)2712 int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
2713 unsigned int flags, bool forbid_cmsg_compat)
2714 {
2715 int err, datagrams;
2716 struct socket *sock;
2717 struct mmsghdr __user *entry;
2718 struct compat_mmsghdr __user *compat_entry;
2719 struct msghdr msg_sys;
2720 struct used_address used_address;
2721 unsigned int oflags = flags;
2722
2723 if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
2724 return -EINVAL;
2725
2726 if (vlen > UIO_MAXIOV)
2727 vlen = UIO_MAXIOV;
2728
2729 datagrams = 0;
2730
2731 CLASS(fd, f)(fd);
2732
2733 if (fd_empty(f))
2734 return -EBADF;
2735 sock = sock_from_file(fd_file(f));
2736 if (unlikely(!sock))
2737 return -ENOTSOCK;
2738
2739 used_address.name_len = UINT_MAX;
2740 entry = mmsg;
2741 compat_entry = (struct compat_mmsghdr __user *)mmsg;
2742 err = 0;
2743 flags |= MSG_BATCH;
2744
2745 while (datagrams < vlen) {
2746 if (datagrams == vlen - 1)
2747 flags = oflags;
2748
2749 if (MSG_CMSG_COMPAT & flags) {
2750 err = ___sys_sendmsg(sock, (struct user_msghdr __user *)compat_entry,
2751 &msg_sys, flags, &used_address, MSG_EOR);
2752 if (err < 0)
2753 break;
2754 err = __put_user(err, &compat_entry->msg_len);
2755 ++compat_entry;
2756 } else {
2757 err = ___sys_sendmsg(sock,
2758 (struct user_msghdr __user *)entry,
2759 &msg_sys, flags, &used_address, MSG_EOR);
2760 if (err < 0)
2761 break;
2762 err = put_user(err, &entry->msg_len);
2763 ++entry;
2764 }
2765
2766 if (err)
2767 break;
2768 ++datagrams;
2769 if (msg_data_left(&msg_sys))
2770 break;
2771 cond_resched();
2772 }
2773
2774 /* We only return an error if no datagrams were able to be sent */
2775 if (datagrams != 0)
2776 return datagrams;
2777
2778 return err;
2779 }
2780
SYSCALL_DEFINE4(sendmmsg,int,fd,struct mmsghdr __user *,mmsg,unsigned int,vlen,unsigned int,flags)2781 SYSCALL_DEFINE4(sendmmsg, int, fd, struct mmsghdr __user *, mmsg,
2782 unsigned int, vlen, unsigned int, flags)
2783 {
2784 return __sys_sendmmsg(fd, mmsg, vlen, flags, true);
2785 }
2786
recvmsg_copy_msghdr(struct msghdr * msg,struct user_msghdr __user * umsg,unsigned flags,struct sockaddr __user ** uaddr,struct iovec ** iov)2787 static int recvmsg_copy_msghdr(struct msghdr *msg,
2788 struct user_msghdr __user *umsg, unsigned flags,
2789 struct sockaddr __user **uaddr,
2790 struct iovec **iov)
2791 {
2792 ssize_t err;
2793
2794 if (MSG_CMSG_COMPAT & flags) {
2795 struct compat_msghdr __user *msg_compat;
2796
2797 msg_compat = (struct compat_msghdr __user *) umsg;
2798 err = get_compat_msghdr(msg, msg_compat, uaddr, iov);
2799 } else {
2800 err = copy_msghdr_from_user(msg, umsg, uaddr, iov);
2801 }
2802 if (err < 0)
2803 return err;
2804
2805 return 0;
2806 }
2807
____sys_recvmsg(struct socket * sock,struct msghdr * msg_sys,struct user_msghdr __user * msg,struct sockaddr __user * uaddr,unsigned int flags,int nosec)2808 static int ____sys_recvmsg(struct socket *sock, struct msghdr *msg_sys,
2809 struct user_msghdr __user *msg,
2810 struct sockaddr __user *uaddr,
2811 unsigned int flags, int nosec)
2812 {
2813 struct compat_msghdr __user *msg_compat =
2814 (struct compat_msghdr __user *) msg;
2815 int __user *uaddr_len = COMPAT_NAMELEN(msg);
2816 struct sockaddr_storage addr;
2817 unsigned long cmsg_ptr;
2818 int len;
2819 ssize_t err;
2820
2821 msg_sys->msg_name = &addr;
2822 cmsg_ptr = (unsigned long)msg_sys->msg_control;
2823 msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
2824
2825 /* We assume all kernel code knows the size of sockaddr_storage */
2826 msg_sys->msg_namelen = 0;
2827
2828 if (sock->file->f_flags & O_NONBLOCK)
2829 flags |= MSG_DONTWAIT;
2830
2831 if (unlikely(nosec))
2832 err = sock_recvmsg_nosec(sock, msg_sys, flags);
2833 else
2834 err = sock_recvmsg(sock, msg_sys, flags);
2835
2836 if (err < 0)
2837 goto out;
2838 len = err;
2839
2840 if (uaddr != NULL) {
2841 err = move_addr_to_user(&addr,
2842 msg_sys->msg_namelen, uaddr,
2843 uaddr_len);
2844 if (err < 0)
2845 goto out;
2846 }
2847 err = __put_user((msg_sys->msg_flags & ~MSG_CMSG_COMPAT),
2848 COMPAT_FLAGS(msg));
2849 if (err)
2850 goto out;
2851 if (MSG_CMSG_COMPAT & flags)
2852 err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
2853 &msg_compat->msg_controllen);
2854 else
2855 err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
2856 &msg->msg_controllen);
2857 if (err)
2858 goto out;
2859 err = len;
2860 out:
2861 return err;
2862 }
2863
___sys_recvmsg(struct socket * sock,struct user_msghdr __user * msg,struct msghdr * msg_sys,unsigned int flags,int nosec)2864 static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
2865 struct msghdr *msg_sys, unsigned int flags, int nosec)
2866 {
2867 struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
2868 /* user mode address pointers */
2869 struct sockaddr __user *uaddr;
2870 ssize_t err;
2871
2872 err = recvmsg_copy_msghdr(msg_sys, msg, flags, &uaddr, &iov);
2873 if (err < 0)
2874 return err;
2875
2876 err = ____sys_recvmsg(sock, msg_sys, msg, uaddr, flags, nosec);
2877 kfree(iov);
2878 return err;
2879 }
2880
2881 /*
2882 * BSD recvmsg interface
2883 */
2884
__sys_recvmsg_sock(struct socket * sock,struct msghdr * msg,struct user_msghdr __user * umsg,struct sockaddr __user * uaddr,unsigned int flags)2885 long __sys_recvmsg_sock(struct socket *sock, struct msghdr *msg,
2886 struct user_msghdr __user *umsg,
2887 struct sockaddr __user *uaddr, unsigned int flags)
2888 {
2889 return ____sys_recvmsg(sock, msg, umsg, uaddr, flags, 0);
2890 }
2891
__sys_recvmsg(int fd,struct user_msghdr __user * msg,unsigned int flags,bool forbid_cmsg_compat)2892 long __sys_recvmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
2893 bool forbid_cmsg_compat)
2894 {
2895 struct msghdr msg_sys;
2896 struct socket *sock;
2897
2898 if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
2899 return -EINVAL;
2900
2901 CLASS(fd, f)(fd);
2902
2903 if (fd_empty(f))
2904 return -EBADF;
2905 sock = sock_from_file(fd_file(f));
2906 if (unlikely(!sock))
2907 return -ENOTSOCK;
2908
2909 return ___sys_recvmsg(sock, msg, &msg_sys, flags, 0);
2910 }
2911
SYSCALL_DEFINE3(recvmsg,int,fd,struct user_msghdr __user *,msg,unsigned int,flags)2912 SYSCALL_DEFINE3(recvmsg, int, fd, struct user_msghdr __user *, msg,
2913 unsigned int, flags)
2914 {
2915 return __sys_recvmsg(fd, msg, flags, true);
2916 }
2917
2918 /*
2919 * Linux recvmmsg interface
2920 */
2921
do_recvmmsg(int fd,struct mmsghdr __user * mmsg,unsigned int vlen,unsigned int flags,struct timespec64 * timeout)2922 static int do_recvmmsg(int fd, struct mmsghdr __user *mmsg,
2923 unsigned int vlen, unsigned int flags,
2924 struct timespec64 *timeout)
2925 {
2926 int err = 0, datagrams;
2927 struct socket *sock;
2928 struct mmsghdr __user *entry;
2929 struct compat_mmsghdr __user *compat_entry;
2930 struct msghdr msg_sys;
2931 struct timespec64 end_time;
2932 struct timespec64 timeout64;
2933
2934 if (timeout &&
2935 poll_select_set_timeout(&end_time, timeout->tv_sec,
2936 timeout->tv_nsec))
2937 return -EINVAL;
2938
2939 datagrams = 0;
2940
2941 CLASS(fd, f)(fd);
2942
2943 if (fd_empty(f))
2944 return -EBADF;
2945 sock = sock_from_file(fd_file(f));
2946 if (unlikely(!sock))
2947 return -ENOTSOCK;
2948
2949 if (likely(!(flags & MSG_ERRQUEUE))) {
2950 err = sock_error(sock->sk);
2951 if (err)
2952 return err;
2953 }
2954
2955 entry = mmsg;
2956 compat_entry = (struct compat_mmsghdr __user *)mmsg;
2957
2958 while (datagrams < vlen) {
2959 /*
2960 * No need to ask LSM for more than the first datagram.
2961 */
2962 if (MSG_CMSG_COMPAT & flags) {
2963 err = ___sys_recvmsg(sock, (struct user_msghdr __user *)compat_entry,
2964 &msg_sys, flags & ~MSG_WAITFORONE,
2965 datagrams);
2966 if (err < 0)
2967 break;
2968 err = __put_user(err, &compat_entry->msg_len);
2969 ++compat_entry;
2970 } else {
2971 err = ___sys_recvmsg(sock,
2972 (struct user_msghdr __user *)entry,
2973 &msg_sys, flags & ~MSG_WAITFORONE,
2974 datagrams);
2975 if (err < 0)
2976 break;
2977 err = put_user(err, &entry->msg_len);
2978 ++entry;
2979 }
2980
2981 if (err)
2982 break;
2983 ++datagrams;
2984
2985 /* MSG_WAITFORONE turns on MSG_DONTWAIT after one packet */
2986 if (flags & MSG_WAITFORONE)
2987 flags |= MSG_DONTWAIT;
2988
2989 if (timeout) {
2990 ktime_get_ts64(&timeout64);
2991 *timeout = timespec64_sub(end_time, timeout64);
2992 if (timeout->tv_sec < 0) {
2993 timeout->tv_sec = timeout->tv_nsec = 0;
2994 break;
2995 }
2996
2997 /* Timeout, return less than vlen datagrams */
2998 if (timeout->tv_nsec == 0 && timeout->tv_sec == 0)
2999 break;
3000 }
3001
3002 /* Out of band data, return right away */
3003 if (msg_sys.msg_flags & MSG_OOB)
3004 break;
3005 cond_resched();
3006 }
3007
3008 if (err == 0)
3009 return datagrams;
3010
3011 if (datagrams == 0)
3012 return err;
3013
3014 /*
3015 * We may return less entries than requested (vlen) if the
3016 * sock is non block and there aren't enough datagrams...
3017 */
3018 if (err != -EAGAIN) {
3019 /*
3020 * ... or if recvmsg returns an error after we
3021 * received some datagrams, where we record the
3022 * error to return on the next call or if the
3023 * app asks about it using getsockopt(SO_ERROR).
3024 */
3025 WRITE_ONCE(sock->sk->sk_err, -err);
3026 }
3027 return datagrams;
3028 }
3029
__sys_recvmmsg(int fd,struct mmsghdr __user * mmsg,unsigned int vlen,unsigned int flags,struct __kernel_timespec __user * timeout,struct old_timespec32 __user * timeout32)3030 int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
3031 unsigned int vlen, unsigned int flags,
3032 struct __kernel_timespec __user *timeout,
3033 struct old_timespec32 __user *timeout32)
3034 {
3035 int datagrams;
3036 struct timespec64 timeout_sys;
3037
3038 if (timeout && get_timespec64(&timeout_sys, timeout))
3039 return -EFAULT;
3040
3041 if (timeout32 && get_old_timespec32(&timeout_sys, timeout32))
3042 return -EFAULT;
3043
3044 if (!timeout && !timeout32)
3045 return do_recvmmsg(fd, mmsg, vlen, flags, NULL);
3046
3047 datagrams = do_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
3048
3049 if (datagrams <= 0)
3050 return datagrams;
3051
3052 if (timeout && put_timespec64(&timeout_sys, timeout))
3053 datagrams = -EFAULT;
3054
3055 if (timeout32 && put_old_timespec32(&timeout_sys, timeout32))
3056 datagrams = -EFAULT;
3057
3058 return datagrams;
3059 }
3060
SYSCALL_DEFINE5(recvmmsg,int,fd,struct mmsghdr __user *,mmsg,unsigned int,vlen,unsigned int,flags,struct __kernel_timespec __user *,timeout)3061 SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg,
3062 unsigned int, vlen, unsigned int, flags,
3063 struct __kernel_timespec __user *, timeout)
3064 {
3065 if (flags & MSG_CMSG_COMPAT)
3066 return -EINVAL;
3067
3068 return __sys_recvmmsg(fd, mmsg, vlen, flags, timeout, NULL);
3069 }
3070
3071 #ifdef CONFIG_COMPAT_32BIT_TIME
SYSCALL_DEFINE5(recvmmsg_time32,int,fd,struct mmsghdr __user *,mmsg,unsigned int,vlen,unsigned int,flags,struct old_timespec32 __user *,timeout)3072 SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct mmsghdr __user *, mmsg,
3073 unsigned int, vlen, unsigned int, flags,
3074 struct old_timespec32 __user *, timeout)
3075 {
3076 if (flags & MSG_CMSG_COMPAT)
3077 return -EINVAL;
3078
3079 return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL, timeout);
3080 }
3081 #endif
3082
3083 #ifdef __ARCH_WANT_SYS_SOCKETCALL
3084 /* Argument list sizes for sys_socketcall */
3085 #define AL(x) ((x) * sizeof(unsigned long))
3086 static const unsigned char nargs[21] = {
3087 AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
3088 AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
3089 AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
3090 AL(4), AL(5), AL(4)
3091 };
3092
3093 #undef AL
3094
3095 /*
3096 * System call vectors.
3097 *
3098 * Argument checking cleaned up. Saved 20% in size.
3099 * This function doesn't need to set the kernel lock because
3100 * it is set by the callees.
3101 */
3102
SYSCALL_DEFINE2(socketcall,int,call,unsigned long __user *,args)3103 SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
3104 {
3105 unsigned long a[AUDITSC_ARGS];
3106 unsigned long a0, a1;
3107 int err;
3108 unsigned int len;
3109
3110 if (call < 1 || call > SYS_SENDMMSG)
3111 return -EINVAL;
3112 call = array_index_nospec(call, SYS_SENDMMSG + 1);
3113
3114 len = nargs[call];
3115 if (len > sizeof(a))
3116 return -EINVAL;
3117
3118 /* copy_from_user should be SMP safe. */
3119 if (copy_from_user(a, args, len))
3120 return -EFAULT;
3121
3122 err = audit_socketcall(nargs[call] / sizeof(unsigned long), a);
3123 if (err)
3124 return err;
3125
3126 a0 = a[0];
3127 a1 = a[1];
3128
3129 switch (call) {
3130 case SYS_SOCKET:
3131 err = __sys_socket(a0, a1, a[2]);
3132 break;
3133 case SYS_BIND:
3134 err = __sys_bind(a0, (struct sockaddr __user *)a1, a[2]);
3135 break;
3136 case SYS_CONNECT:
3137 err = __sys_connect(a0, (struct sockaddr __user *)a1, a[2]);
3138 break;
3139 case SYS_LISTEN:
3140 err = __sys_listen(a0, a1);
3141 break;
3142 case SYS_ACCEPT:
3143 err = __sys_accept4(a0, (struct sockaddr __user *)a1,
3144 (int __user *)a[2], 0);
3145 break;
3146 case SYS_GETSOCKNAME:
3147 err =
3148 __sys_getsockname(a0, (struct sockaddr __user *)a1,
3149 (int __user *)a[2]);
3150 break;
3151 case SYS_GETPEERNAME:
3152 err =
3153 __sys_getpeername(a0, (struct sockaddr __user *)a1,
3154 (int __user *)a[2]);
3155 break;
3156 case SYS_SOCKETPAIR:
3157 err = __sys_socketpair(a0, a1, a[2], (int __user *)a[3]);
3158 break;
3159 case SYS_SEND:
3160 err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
3161 NULL, 0);
3162 break;
3163 case SYS_SENDTO:
3164 err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
3165 (struct sockaddr __user *)a[4], a[5]);
3166 break;
3167 case SYS_RECV:
3168 err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
3169 NULL, NULL);
3170 break;
3171 case SYS_RECVFROM:
3172 err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
3173 (struct sockaddr __user *)a[4],
3174 (int __user *)a[5]);
3175 break;
3176 case SYS_SHUTDOWN:
3177 err = __sys_shutdown(a0, a1);
3178 break;
3179 case SYS_SETSOCKOPT:
3180 err = __sys_setsockopt(a0, a1, a[2], (char __user *)a[3],
3181 a[4]);
3182 break;
3183 case SYS_GETSOCKOPT:
3184 err =
3185 __sys_getsockopt(a0, a1, a[2], (char __user *)a[3],
3186 (int __user *)a[4]);
3187 break;
3188 case SYS_SENDMSG:
3189 err = __sys_sendmsg(a0, (struct user_msghdr __user *)a1,
3190 a[2], true);
3191 break;
3192 case SYS_SENDMMSG:
3193 err = __sys_sendmmsg(a0, (struct mmsghdr __user *)a1, a[2],
3194 a[3], true);
3195 break;
3196 case SYS_RECVMSG:
3197 err = __sys_recvmsg(a0, (struct user_msghdr __user *)a1,
3198 a[2], true);
3199 break;
3200 case SYS_RECVMMSG:
3201 if (IS_ENABLED(CONFIG_64BIT))
3202 err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
3203 a[2], a[3],
3204 (struct __kernel_timespec __user *)a[4],
3205 NULL);
3206 else
3207 err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
3208 a[2], a[3], NULL,
3209 (struct old_timespec32 __user *)a[4]);
3210 break;
3211 case SYS_ACCEPT4:
3212 err = __sys_accept4(a0, (struct sockaddr __user *)a1,
3213 (int __user *)a[2], a[3]);
3214 break;
3215 default:
3216 err = -EINVAL;
3217 break;
3218 }
3219 return err;
3220 }
3221
3222 #endif /* __ARCH_WANT_SYS_SOCKETCALL */
3223
3224 /**
3225 * sock_register - add a socket protocol handler
3226 * @ops: description of protocol
3227 *
3228 * This function is called by a protocol handler that wants to
3229 * advertise its address family, and have it linked into the
3230 * socket interface. The value ops->family corresponds to the
3231 * socket system call protocol family.
3232 */
sock_register(const struct net_proto_family * ops)3233 int sock_register(const struct net_proto_family *ops)
3234 {
3235 int err;
3236
3237 if (ops->family >= NPROTO) {
3238 pr_crit("protocol %d >= NPROTO(%d)\n", ops->family, NPROTO);
3239 return -ENOBUFS;
3240 }
3241
3242 spin_lock(&net_family_lock);
3243 if (rcu_dereference_protected(net_families[ops->family],
3244 lockdep_is_held(&net_family_lock)))
3245 err = -EEXIST;
3246 else {
3247 rcu_assign_pointer(net_families[ops->family], ops);
3248 err = 0;
3249 }
3250 spin_unlock(&net_family_lock);
3251
3252 pr_info("NET: Registered %s protocol family\n", pf_family_names[ops->family]);
3253 return err;
3254 }
3255 EXPORT_SYMBOL(sock_register);
3256
3257 /**
3258 * sock_unregister - remove a protocol handler
3259 * @family: protocol family to remove
3260 *
3261 * This function is called by a protocol handler that wants to
3262 * remove its address family, and have it unlinked from the
3263 * new socket creation.
3264 *
3265 * If protocol handler is a module, then it can use module reference
3266 * counts to protect against new references. If protocol handler is not
3267 * a module then it needs to provide its own protection in
3268 * the ops->create routine.
3269 */
sock_unregister(int family)3270 void sock_unregister(int family)
3271 {
3272 BUG_ON(family < 0 || family >= NPROTO);
3273
3274 spin_lock(&net_family_lock);
3275 RCU_INIT_POINTER(net_families[family], NULL);
3276 spin_unlock(&net_family_lock);
3277
3278 synchronize_rcu();
3279
3280 pr_info("NET: Unregistered %s protocol family\n", pf_family_names[family]);
3281 }
3282 EXPORT_SYMBOL(sock_unregister);
3283
sock_is_registered(int family)3284 bool sock_is_registered(int family)
3285 {
3286 return family < NPROTO && rcu_access_pointer(net_families[family]);
3287 }
3288
sock_init(void)3289 static int __init sock_init(void)
3290 {
3291 int err;
3292 /*
3293 * Initialize the network sysctl infrastructure.
3294 */
3295 err = net_sysctl_init();
3296 if (err)
3297 goto out;
3298
3299 /*
3300 * Initialize skbuff SLAB cache
3301 */
3302 skb_init();
3303
3304 /*
3305 * Initialize the protocols module.
3306 */
3307
3308 init_inodecache();
3309
3310 err = register_filesystem(&sock_fs_type);
3311 if (err)
3312 goto out;
3313 sock_mnt = kern_mount(&sock_fs_type);
3314 if (IS_ERR(sock_mnt)) {
3315 err = PTR_ERR(sock_mnt);
3316 goto out_mount;
3317 }
3318
3319 /* The real protocol initialization is performed in later initcalls.
3320 */
3321
3322 #ifdef CONFIG_NETFILTER
3323 err = netfilter_init();
3324 if (err)
3325 goto out;
3326 #endif
3327
3328 ptp_classifier_init();
3329
3330 out:
3331 return err;
3332
3333 out_mount:
3334 unregister_filesystem(&sock_fs_type);
3335 goto out;
3336 }
3337
3338 core_initcall(sock_init); /* early initcall */
3339
3340 #ifdef CONFIG_PROC_FS
socket_seq_show(struct seq_file * seq)3341 void socket_seq_show(struct seq_file *seq)
3342 {
3343 seq_printf(seq, "sockets: used %d\n",
3344 sock_inuse_get(seq->private));
3345 }
3346 #endif /* CONFIG_PROC_FS */
3347
3348 /* Handle the fact that while struct ifreq has the same *layout* on
3349 * 32/64 for everything but ifreq::ifru_ifmap and ifreq::ifru_data,
3350 * which are handled elsewhere, it still has different *size* due to
3351 * ifreq::ifru_ifmap (which is 16 bytes on 32 bit, 24 bytes on 64-bit,
3352 * resulting in struct ifreq being 32 and 40 bytes respectively).
3353 * As a result, if the struct happens to be at the end of a page and
3354 * the next page isn't readable/writable, we get a fault. To prevent
3355 * that, copy back and forth to the full size.
3356 */
get_user_ifreq(struct ifreq * ifr,void __user ** ifrdata,void __user * arg)3357 int get_user_ifreq(struct ifreq *ifr, void __user **ifrdata, void __user *arg)
3358 {
3359 if (in_compat_syscall()) {
3360 struct compat_ifreq *ifr32 = (struct compat_ifreq *)ifr;
3361
3362 memset(ifr, 0, sizeof(*ifr));
3363 if (copy_from_user(ifr32, arg, sizeof(*ifr32)))
3364 return -EFAULT;
3365
3366 if (ifrdata)
3367 *ifrdata = compat_ptr(ifr32->ifr_data);
3368
3369 return 0;
3370 }
3371
3372 if (copy_from_user(ifr, arg, sizeof(*ifr)))
3373 return -EFAULT;
3374
3375 if (ifrdata)
3376 *ifrdata = ifr->ifr_data;
3377
3378 return 0;
3379 }
3380 EXPORT_SYMBOL(get_user_ifreq);
3381
put_user_ifreq(struct ifreq * ifr,void __user * arg)3382 int put_user_ifreq(struct ifreq *ifr, void __user *arg)
3383 {
3384 size_t size = sizeof(*ifr);
3385
3386 if (in_compat_syscall())
3387 size = sizeof(struct compat_ifreq);
3388
3389 if (copy_to_user(arg, ifr, size))
3390 return -EFAULT;
3391
3392 return 0;
3393 }
3394 EXPORT_SYMBOL(put_user_ifreq);
3395
3396 #ifdef CONFIG_COMPAT
compat_siocwandev(struct net * net,struct compat_ifreq __user * uifr32)3397 static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32)
3398 {
3399 compat_uptr_t uptr32;
3400 struct ifreq ifr;
3401 void __user *saved;
3402 int err;
3403
3404 if (get_user_ifreq(&ifr, NULL, uifr32))
3405 return -EFAULT;
3406
3407 if (get_user(uptr32, &uifr32->ifr_settings.ifs_ifsu))
3408 return -EFAULT;
3409
3410 saved = ifr.ifr_settings.ifs_ifsu.raw_hdlc;
3411 ifr.ifr_settings.ifs_ifsu.raw_hdlc = compat_ptr(uptr32);
3412
3413 err = dev_ioctl(net, SIOCWANDEV, &ifr, NULL, NULL);
3414 if (!err) {
3415 ifr.ifr_settings.ifs_ifsu.raw_hdlc = saved;
3416 if (put_user_ifreq(&ifr, uifr32))
3417 err = -EFAULT;
3418 }
3419 return err;
3420 }
3421
3422 /* Handle ioctls that use ifreq::ifr_data and just need struct ifreq converted */
compat_ifr_data_ioctl(struct net * net,unsigned int cmd,struct compat_ifreq __user * u_ifreq32)3423 static int compat_ifr_data_ioctl(struct net *net, unsigned int cmd,
3424 struct compat_ifreq __user *u_ifreq32)
3425 {
3426 struct ifreq ifreq;
3427 void __user *data;
3428
3429 if (!is_socket_ioctl_cmd(cmd))
3430 return -ENOTTY;
3431 if (get_user_ifreq(&ifreq, &data, u_ifreq32))
3432 return -EFAULT;
3433 ifreq.ifr_data = data;
3434
3435 return dev_ioctl(net, cmd, &ifreq, data, NULL);
3436 }
3437
compat_sock_ioctl_trans(struct file * file,struct socket * sock,unsigned int cmd,unsigned long arg)3438 static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
3439 unsigned int cmd, unsigned long arg)
3440 {
3441 void __user *argp = compat_ptr(arg);
3442 struct sock *sk = sock->sk;
3443 struct net *net = sock_net(sk);
3444 const struct proto_ops *ops;
3445
3446 if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))
3447 return sock_ioctl(file, cmd, (unsigned long)argp);
3448
3449 switch (cmd) {
3450 case SIOCWANDEV:
3451 return compat_siocwandev(net, argp);
3452 case SIOCGSTAMP_OLD:
3453 case SIOCGSTAMPNS_OLD:
3454 ops = READ_ONCE(sock->ops);
3455 if (!ops->gettstamp)
3456 return -ENOIOCTLCMD;
3457 return ops->gettstamp(sock, argp, cmd == SIOCGSTAMP_OLD,
3458 !COMPAT_USE_64BIT_TIME);
3459
3460 case SIOCETHTOOL:
3461 case SIOCBONDSLAVEINFOQUERY:
3462 case SIOCBONDINFOQUERY:
3463 case SIOCSHWTSTAMP:
3464 case SIOCGHWTSTAMP:
3465 return compat_ifr_data_ioctl(net, cmd, argp);
3466
3467 case FIOSETOWN:
3468 case SIOCSPGRP:
3469 case FIOGETOWN:
3470 case SIOCGPGRP:
3471 case SIOCBRADDBR:
3472 case SIOCBRDELBR:
3473 case SIOCBRADDIF:
3474 case SIOCBRDELIF:
3475 case SIOCGIFVLAN:
3476 case SIOCSIFVLAN:
3477 case SIOCGSKNS:
3478 case SIOCGSTAMP_NEW:
3479 case SIOCGSTAMPNS_NEW:
3480 case SIOCGIFCONF:
3481 case SIOCSIFBR:
3482 case SIOCGIFBR:
3483 return sock_ioctl(file, cmd, arg);
3484
3485 case SIOCGIFFLAGS:
3486 case SIOCSIFFLAGS:
3487 case SIOCGIFMAP:
3488 case SIOCSIFMAP:
3489 case SIOCGIFMETRIC:
3490 case SIOCSIFMETRIC:
3491 case SIOCGIFMTU:
3492 case SIOCSIFMTU:
3493 case SIOCGIFMEM:
3494 case SIOCSIFMEM:
3495 case SIOCGIFHWADDR:
3496 case SIOCSIFHWADDR:
3497 case SIOCADDMULTI:
3498 case SIOCDELMULTI:
3499 case SIOCGIFINDEX:
3500 case SIOCGIFADDR:
3501 case SIOCSIFADDR:
3502 case SIOCSIFHWBROADCAST:
3503 case SIOCDIFADDR:
3504 case SIOCGIFBRDADDR:
3505 case SIOCSIFBRDADDR:
3506 case SIOCGIFDSTADDR:
3507 case SIOCSIFDSTADDR:
3508 case SIOCGIFNETMASK:
3509 case SIOCSIFNETMASK:
3510 case SIOCSIFPFLAGS:
3511 case SIOCGIFPFLAGS:
3512 case SIOCGIFTXQLEN:
3513 case SIOCSIFTXQLEN:
3514 case SIOCGIFNAME:
3515 case SIOCSIFNAME:
3516 case SIOCGMIIPHY:
3517 case SIOCGMIIREG:
3518 case SIOCSMIIREG:
3519 case SIOCBONDENSLAVE:
3520 case SIOCBONDRELEASE:
3521 case SIOCBONDSETHWADDR:
3522 case SIOCBONDCHANGEACTIVE:
3523 case SIOCSARP:
3524 case SIOCGARP:
3525 case SIOCDARP:
3526 case SIOCOUTQ:
3527 case SIOCOUTQNSD:
3528 case SIOCATMARK:
3529 return sock_do_ioctl(net, sock, cmd, arg);
3530 }
3531
3532 return -ENOIOCTLCMD;
3533 }
3534
compat_sock_ioctl(struct file * file,unsigned int cmd,unsigned long arg)3535 static long compat_sock_ioctl(struct file *file, unsigned int cmd,
3536 unsigned long arg)
3537 {
3538 struct socket *sock = file->private_data;
3539 const struct proto_ops *ops = READ_ONCE(sock->ops);
3540 int ret = -ENOIOCTLCMD;
3541 struct sock *sk;
3542 struct net *net;
3543
3544 sk = sock->sk;
3545 net = sock_net(sk);
3546
3547 if (ops->compat_ioctl)
3548 ret = ops->compat_ioctl(sock, cmd, arg);
3549
3550 if (ret == -ENOIOCTLCMD &&
3551 (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST))
3552 ret = compat_wext_handle_ioctl(net, cmd, arg);
3553
3554 if (ret == -ENOIOCTLCMD)
3555 ret = compat_sock_ioctl_trans(file, sock, cmd, arg);
3556
3557 return ret;
3558 }
3559 #endif
3560
3561 /**
3562 * kernel_bind - bind an address to a socket (kernel space)
3563 * @sock: socket
3564 * @addr: address
3565 * @addrlen: length of address
3566 *
3567 * Returns 0 or an error.
3568 */
3569
kernel_bind(struct socket * sock,struct sockaddr * addr,int addrlen)3570 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
3571 {
3572 struct sockaddr_storage address;
3573
3574 memcpy(&address, addr, addrlen);
3575
3576 return READ_ONCE(sock->ops)->bind(sock, (struct sockaddr *)&address,
3577 addrlen);
3578 }
3579 EXPORT_SYMBOL(kernel_bind);
3580
3581 /**
3582 * kernel_listen - move socket to listening state (kernel space)
3583 * @sock: socket
3584 * @backlog: pending connections queue size
3585 *
3586 * Returns 0 or an error.
3587 */
3588
kernel_listen(struct socket * sock,int backlog)3589 int kernel_listen(struct socket *sock, int backlog)
3590 {
3591 return READ_ONCE(sock->ops)->listen(sock, backlog);
3592 }
3593 EXPORT_SYMBOL(kernel_listen);
3594
3595 /**
3596 * kernel_accept - accept a connection (kernel space)
3597 * @sock: listening socket
3598 * @newsock: new connected socket
3599 * @flags: flags
3600 *
3601 * @flags must be SOCK_CLOEXEC, SOCK_NONBLOCK or 0.
3602 * If it fails, @newsock is guaranteed to be %NULL.
3603 * Returns 0 or an error.
3604 */
3605
kernel_accept(struct socket * sock,struct socket ** newsock,int flags)3606 int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
3607 {
3608 struct sock *sk = sock->sk;
3609 const struct proto_ops *ops = READ_ONCE(sock->ops);
3610 struct proto_accept_arg arg = {
3611 .flags = flags,
3612 .kern = true,
3613 };
3614 int err;
3615
3616 err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
3617 newsock);
3618 if (err < 0)
3619 goto done;
3620
3621 err = ops->accept(sock, *newsock, &arg);
3622 if (err < 0) {
3623 sock_release(*newsock);
3624 *newsock = NULL;
3625 goto done;
3626 }
3627
3628 (*newsock)->ops = ops;
3629 __module_get(ops->owner);
3630
3631 done:
3632 return err;
3633 }
3634 EXPORT_SYMBOL(kernel_accept);
3635
3636 /**
3637 * kernel_connect - connect a socket (kernel space)
3638 * @sock: socket
3639 * @addr: address
3640 * @addrlen: address length
3641 * @flags: flags (O_NONBLOCK, ...)
3642 *
3643 * For datagram sockets, @addr is the address to which datagrams are sent
3644 * by default, and the only address from which datagrams are received.
3645 * For stream sockets, attempts to connect to @addr.
3646 * Returns 0 or an error code.
3647 */
3648
kernel_connect(struct socket * sock,struct sockaddr * addr,int addrlen,int flags)3649 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
3650 int flags)
3651 {
3652 struct sockaddr_storage address;
3653
3654 memcpy(&address, addr, addrlen);
3655
3656 return READ_ONCE(sock->ops)->connect(sock, (struct sockaddr *)&address,
3657 addrlen, flags);
3658 }
3659 EXPORT_SYMBOL(kernel_connect);
3660
3661 /**
3662 * kernel_getsockname - get the address which the socket is bound (kernel space)
3663 * @sock: socket
3664 * @addr: address holder
3665 *
3666 * Fills the @addr pointer with the address which the socket is bound.
3667 * Returns the length of the address in bytes or an error code.
3668 */
3669
kernel_getsockname(struct socket * sock,struct sockaddr * addr)3670 int kernel_getsockname(struct socket *sock, struct sockaddr *addr)
3671 {
3672 return READ_ONCE(sock->ops)->getname(sock, addr, 0);
3673 }
3674 EXPORT_SYMBOL(kernel_getsockname);
3675
3676 /**
3677 * kernel_getpeername - get the address which the socket is connected (kernel space)
3678 * @sock: socket
3679 * @addr: address holder
3680 *
3681 * Fills the @addr pointer with the address which the socket is connected.
3682 * Returns the length of the address in bytes or an error code.
3683 */
3684
kernel_getpeername(struct socket * sock,struct sockaddr * addr)3685 int kernel_getpeername(struct socket *sock, struct sockaddr *addr)
3686 {
3687 return READ_ONCE(sock->ops)->getname(sock, addr, 1);
3688 }
3689 EXPORT_SYMBOL(kernel_getpeername);
3690
3691 /**
3692 * kernel_sock_shutdown - shut down part of a full-duplex connection (kernel space)
3693 * @sock: socket
3694 * @how: connection part
3695 *
3696 * Returns 0 or an error.
3697 */
3698
kernel_sock_shutdown(struct socket * sock,enum sock_shutdown_cmd how)3699 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
3700 {
3701 return READ_ONCE(sock->ops)->shutdown(sock, how);
3702 }
3703 EXPORT_SYMBOL(kernel_sock_shutdown);
3704
3705 /**
3706 * kernel_sock_ip_overhead - returns the IP overhead imposed by a socket
3707 * @sk: socket
3708 *
3709 * This routine returns the IP overhead imposed by a socket i.e.
3710 * the length of the underlying IP header, depending on whether
3711 * this is an IPv4 or IPv6 socket and the length from IP options turned
3712 * on at the socket. Assumes that the caller has a lock on the socket.
3713 */
3714
kernel_sock_ip_overhead(struct sock * sk)3715 u32 kernel_sock_ip_overhead(struct sock *sk)
3716 {
3717 struct inet_sock *inet;
3718 struct ip_options_rcu *opt;
3719 u32 overhead = 0;
3720 #if IS_ENABLED(CONFIG_IPV6)
3721 struct ipv6_pinfo *np;
3722 struct ipv6_txoptions *optv6 = NULL;
3723 #endif /* IS_ENABLED(CONFIG_IPV6) */
3724
3725 if (!sk)
3726 return overhead;
3727
3728 switch (sk->sk_family) {
3729 case AF_INET:
3730 inet = inet_sk(sk);
3731 overhead += sizeof(struct iphdr);
3732 opt = rcu_dereference_protected(inet->inet_opt,
3733 sock_owned_by_user(sk));
3734 if (opt)
3735 overhead += opt->opt.optlen;
3736 return overhead;
3737 #if IS_ENABLED(CONFIG_IPV6)
3738 case AF_INET6:
3739 np = inet6_sk(sk);
3740 overhead += sizeof(struct ipv6hdr);
3741 if (np)
3742 optv6 = rcu_dereference_protected(np->opt,
3743 sock_owned_by_user(sk));
3744 if (optv6)
3745 overhead += (optv6->opt_flen + optv6->opt_nflen);
3746 return overhead;
3747 #endif /* IS_ENABLED(CONFIG_IPV6) */
3748 default: /* Returns 0 overhead if the socket is not ipv4 or ipv6 */
3749 return overhead;
3750 }
3751 }
3752 EXPORT_SYMBOL(kernel_sock_ip_overhead);
3753