1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * The User Datagram Protocol (UDP). 7 * 8 * Version: $Id: udp.c,v 1.102 2002/02/01 22:01:04 davem Exp $ 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 13 * Alan Cox, <Alan.Cox@linux.org> 14 * Hirokazu Takahashi, <taka@valinux.co.jp> 15 * 16 * Fixes: 17 * Alan Cox : verify_area() calls 18 * Alan Cox : stopped close while in use off icmp 19 * messages. Not a fix but a botch that 20 * for udp at least is 'valid'. 21 * Alan Cox : Fixed icmp handling properly 22 * Alan Cox : Correct error for oversized datagrams 23 * Alan Cox : Tidied select() semantics. 24 * Alan Cox : udp_err() fixed properly, also now 25 * select and read wake correctly on errors 26 * Alan Cox : udp_send verify_area moved to avoid mem leak 27 * Alan Cox : UDP can count its memory 28 * Alan Cox : send to an unknown connection causes 29 * an ECONNREFUSED off the icmp, but 30 * does NOT close. 31 * Alan Cox : Switched to new sk_buff handlers. No more backlog! 32 * Alan Cox : Using generic datagram code. Even smaller and the PEEK 33 * bug no longer crashes it. 34 * Fred Van Kempen : Net2e support for sk->broadcast. 35 * Alan Cox : Uses skb_free_datagram 36 * Alan Cox : Added get/set sockopt support. 37 * Alan Cox : Broadcasting without option set returns EACCES. 38 * Alan Cox : No wakeup calls. Instead we now use the callbacks. 39 * Alan Cox : Use ip_tos and ip_ttl 40 * Alan Cox : SNMP Mibs 41 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. 42 * Matt Dillon : UDP length checks. 43 * Alan Cox : Smarter af_inet used properly. 44 * Alan Cox : Use new kernel side addressing. 45 * Alan Cox : Incorrect return on truncated datagram receive. 46 * Arnt Gulbrandsen : New udp_send and stuff 47 * Alan Cox : Cache last socket 48 * Alan Cox : Route cache 49 * Jon Peatfield : Minor efficiency fix to sendto(). 50 * Mike Shaver : RFC1122 checks. 51 * Alan Cox : Nonblocking error fix. 52 * Willy Konynenberg : Transparent proxying support. 53 * Mike McLagan : Routing by source 54 * David S. Miller : New socket lookup architecture. 55 * Last socket cache retained as it 56 * does have a high hit rate. 57 * Olaf Kirch : Don't linearise iovec on sendmsg. 58 * Andi Kleen : Some cleanups, cache destination entry 59 * for connect. 60 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 61 * Melvin Smith : Check msg_name not msg_namelen in sendto(), 62 * return ENOTCONN for unconnected sockets (POSIX) 63 * Janos Farkas : don't deliver multi/broadcasts to a different 64 * bound-to-device socket 65 * Hirokazu Takahashi : HW checksumming for outgoing UDP 66 * datagrams. 67 * Hirokazu Takahashi : sendfile() on UDP works now. 68 * Arnaldo C. Melo : convert /proc/net/udp to seq_file 69 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 70 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind 71 * a single port at the same time. 72 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support 73 * 74 * 75 * This program is free software; you can redistribute it and/or 76 * modify it under the terms of the GNU General Public License 77 * as published by the Free Software Foundation; either version 78 * 2 of the License, or (at your option) any later version. 79 */ 80 81 #include <asm/system.h> 82 #include <asm/uaccess.h> 83 #include <asm/ioctls.h> 84 #include <linux/types.h> 85 #include <linux/fcntl.h> 86 #include <linux/module.h> 87 #include <linux/socket.h> 88 #include <linux/sockios.h> 89 #include <linux/igmp.h> 90 #include <linux/in.h> 91 #include <linux/errno.h> 92 #include <linux/timer.h> 93 #include <linux/mm.h> 94 #include <linux/inet.h> 95 #include <linux/netdevice.h> 96 #include <net/tcp_states.h> 97 #include <linux/skbuff.h> 98 #include <linux/proc_fs.h> 99 #include <linux/seq_file.h> 100 #include <net/icmp.h> 101 #include <net/route.h> 102 #include <net/checksum.h> 103 #include <net/xfrm.h> 104 #include "udp_impl.h" 105 106 /* 107 * Snmp MIB for the UDP layer 108 */ 109 110 DEFINE_SNMP_STAT(struct udp_mib, udp_statistics) __read_mostly; 111 112 struct hlist_head udp_hash[UDP_HTABLE_SIZE]; 113 DEFINE_RWLOCK(udp_hash_lock); 114 115 static int udp_port_rover; 116 117 static inline int __udp_lib_lport_inuse(__u16 num, struct hlist_head udptable[]) 118 { 119 struct sock *sk; 120 struct hlist_node *node; 121 122 sk_for_each(sk, node, &udptable[num & (UDP_HTABLE_SIZE - 1)]) 123 if (inet_sk(sk)->num == num) 124 return 1; 125 return 0; 126 } 127 128 /** 129 * __udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 130 * 131 * @sk: socket struct in question 132 * @snum: port number to look up 133 * @udptable: hash list table, must be of UDP_HTABLE_SIZE 134 * @port_rover: pointer to record of last unallocated port 135 * @saddr_comp: AF-dependent comparison of bound local IP addresses 136 */ 137 int __udp_lib_get_port(struct sock *sk, unsigned short snum, 138 struct hlist_head udptable[], int *port_rover, 139 int (*saddr_comp)(const struct sock *sk1, 140 const struct sock *sk2 ) ) 141 { 142 struct hlist_node *node; 143 struct hlist_head *head; 144 struct sock *sk2; 145 int error = 1; 146 147 write_lock_bh(&udp_hash_lock); 148 if (snum == 0) { 149 int best_size_so_far, best, result, i; 150 151 if (*port_rover > sysctl_local_port_range[1] || 152 *port_rover < sysctl_local_port_range[0]) 153 *port_rover = sysctl_local_port_range[0]; 154 best_size_so_far = 32767; 155 best = result = *port_rover; 156 for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) { 157 int size; 158 159 head = &udptable[result & (UDP_HTABLE_SIZE - 1)]; 160 if (hlist_empty(head)) { 161 if (result > sysctl_local_port_range[1]) 162 result = sysctl_local_port_range[0] + 163 ((result - sysctl_local_port_range[0]) & 164 (UDP_HTABLE_SIZE - 1)); 165 goto gotit; 166 } 167 size = 0; 168 sk_for_each(sk2, node, head) 169 if (++size < best_size_so_far) { 170 best_size_so_far = size; 171 best = result; 172 } 173 } 174 result = best; 175 for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) { 176 if (result > sysctl_local_port_range[1]) 177 result = sysctl_local_port_range[0] 178 + ((result - sysctl_local_port_range[0]) & 179 (UDP_HTABLE_SIZE - 1)); 180 if (! __udp_lib_lport_inuse(result, udptable)) 181 break; 182 } 183 if (i >= (1 << 16) / UDP_HTABLE_SIZE) 184 goto fail; 185 gotit: 186 *port_rover = snum = result; 187 } else { 188 head = &udptable[snum & (UDP_HTABLE_SIZE - 1)]; 189 190 sk_for_each(sk2, node, head) 191 if (inet_sk(sk2)->num == snum && 192 sk2 != sk && 193 (!sk2->sk_reuse || !sk->sk_reuse) && 194 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if 195 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 196 (*saddr_comp)(sk, sk2) ) 197 goto fail; 198 } 199 inet_sk(sk)->num = snum; 200 if (sk_unhashed(sk)) { 201 head = &udptable[snum & (UDP_HTABLE_SIZE - 1)]; 202 sk_add_node(sk, head); 203 sock_prot_inc_use(sk->sk_prot); 204 } 205 error = 0; 206 fail: 207 write_unlock_bh(&udp_hash_lock); 208 return error; 209 } 210 211 __inline__ int udp_get_port(struct sock *sk, unsigned short snum, 212 int (*scmp)(const struct sock *, const struct sock *)) 213 { 214 return __udp_lib_get_port(sk, snum, udp_hash, &udp_port_rover, scmp); 215 } 216 217 inline int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 218 { 219 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 220 221 return ( !ipv6_only_sock(sk2) && 222 (!inet1->rcv_saddr || !inet2->rcv_saddr || 223 inet1->rcv_saddr == inet2->rcv_saddr )); 224 } 225 226 static inline int udp_v4_get_port(struct sock *sk, unsigned short snum) 227 { 228 return udp_get_port(sk, snum, ipv4_rcv_saddr_equal); 229 } 230 231 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 232 * harder than this. -DaveM 233 */ 234 static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport, 235 __be32 daddr, __be16 dport, 236 int dif, struct hlist_head udptable[]) 237 { 238 struct sock *sk, *result = NULL; 239 struct hlist_node *node; 240 unsigned short hnum = ntohs(dport); 241 int badness = -1; 242 243 read_lock(&udp_hash_lock); 244 sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) { 245 struct inet_sock *inet = inet_sk(sk); 246 247 if (inet->num == hnum && !ipv6_only_sock(sk)) { 248 int score = (sk->sk_family == PF_INET ? 1 : 0); 249 if (inet->rcv_saddr) { 250 if (inet->rcv_saddr != daddr) 251 continue; 252 score+=2; 253 } 254 if (inet->daddr) { 255 if (inet->daddr != saddr) 256 continue; 257 score+=2; 258 } 259 if (inet->dport) { 260 if (inet->dport != sport) 261 continue; 262 score+=2; 263 } 264 if (sk->sk_bound_dev_if) { 265 if (sk->sk_bound_dev_if != dif) 266 continue; 267 score+=2; 268 } 269 if(score == 9) { 270 result = sk; 271 break; 272 } else if(score > badness) { 273 result = sk; 274 badness = score; 275 } 276 } 277 } 278 if (result) 279 sock_hold(result); 280 read_unlock(&udp_hash_lock); 281 return result; 282 } 283 284 static inline struct sock *udp_v4_mcast_next(struct sock *sk, 285 __be16 loc_port, __be32 loc_addr, 286 __be16 rmt_port, __be32 rmt_addr, 287 int dif) 288 { 289 struct hlist_node *node; 290 struct sock *s = sk; 291 unsigned short hnum = ntohs(loc_port); 292 293 sk_for_each_from(s, node) { 294 struct inet_sock *inet = inet_sk(s); 295 296 if (inet->num != hnum || 297 (inet->daddr && inet->daddr != rmt_addr) || 298 (inet->dport != rmt_port && inet->dport) || 299 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) || 300 ipv6_only_sock(s) || 301 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) 302 continue; 303 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) 304 continue; 305 goto found; 306 } 307 s = NULL; 308 found: 309 return s; 310 } 311 312 /* 313 * This routine is called by the ICMP module when it gets some 314 * sort of error condition. If err < 0 then the socket should 315 * be closed and the error returned to the user. If err > 0 316 * it's just the icmp type << 8 | icmp code. 317 * Header points to the ip header of the error packet. We move 318 * on past this. Then (as it used to claim before adjustment) 319 * header points to the first 8 bytes of the udp header. We need 320 * to find the appropriate port. 321 */ 322 323 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[]) 324 { 325 struct inet_sock *inet; 326 struct iphdr *iph = (struct iphdr*)skb->data; 327 struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2)); 328 int type = skb->h.icmph->type; 329 int code = skb->h.icmph->code; 330 struct sock *sk; 331 int harderr; 332 int err; 333 334 sk = __udp4_lib_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, 335 skb->dev->ifindex, udptable ); 336 if (sk == NULL) { 337 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); 338 return; /* No socket for error */ 339 } 340 341 err = 0; 342 harderr = 0; 343 inet = inet_sk(sk); 344 345 switch (type) { 346 default: 347 case ICMP_TIME_EXCEEDED: 348 err = EHOSTUNREACH; 349 break; 350 case ICMP_SOURCE_QUENCH: 351 goto out; 352 case ICMP_PARAMETERPROB: 353 err = EPROTO; 354 harderr = 1; 355 break; 356 case ICMP_DEST_UNREACH: 357 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 358 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 359 err = EMSGSIZE; 360 harderr = 1; 361 break; 362 } 363 goto out; 364 } 365 err = EHOSTUNREACH; 366 if (code <= NR_ICMP_UNREACH) { 367 harderr = icmp_err_convert[code].fatal; 368 err = icmp_err_convert[code].errno; 369 } 370 break; 371 } 372 373 /* 374 * RFC1122: OK. Passes ICMP errors back to application, as per 375 * 4.1.3.3. 376 */ 377 if (!inet->recverr) { 378 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 379 goto out; 380 } else { 381 ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1)); 382 } 383 sk->sk_err = err; 384 sk->sk_error_report(sk); 385 out: 386 sock_put(sk); 387 } 388 389 __inline__ void udp_err(struct sk_buff *skb, u32 info) 390 { 391 return __udp4_lib_err(skb, info, udp_hash); 392 } 393 394 /* 395 * Throw away all pending data and cancel the corking. Socket is locked. 396 */ 397 static void udp_flush_pending_frames(struct sock *sk) 398 { 399 struct udp_sock *up = udp_sk(sk); 400 401 if (up->pending) { 402 up->len = 0; 403 up->pending = 0; 404 ip_flush_pending_frames(sk); 405 } 406 } 407 408 /** 409 * udp4_hwcsum_outgoing - handle outgoing HW checksumming 410 * @sk: socket we are sending on 411 * @skb: sk_buff containing the filled-in UDP header 412 * (checksum field must be zeroed out) 413 */ 414 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, 415 __be32 src, __be32 dst, int len ) 416 { 417 unsigned int offset; 418 struct udphdr *uh = skb->h.uh; 419 __wsum csum = 0; 420 421 if (skb_queue_len(&sk->sk_write_queue) == 1) { 422 /* 423 * Only one fragment on the socket. 424 */ 425 skb->csum_offset = offsetof(struct udphdr, check); 426 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0); 427 } else { 428 /* 429 * HW-checksum won't work as there are two or more 430 * fragments on the socket so that all csums of sk_buffs 431 * should be together 432 */ 433 offset = skb->h.raw - skb->data; 434 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); 435 436 skb->ip_summed = CHECKSUM_NONE; 437 438 skb_queue_walk(&sk->sk_write_queue, skb) { 439 csum = csum_add(csum, skb->csum); 440 } 441 442 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 443 if (uh->check == 0) 444 uh->check = CSUM_MANGLED_0; 445 } 446 } 447 448 /* 449 * Push out all pending data as one UDP datagram. Socket is locked. 450 */ 451 static int udp_push_pending_frames(struct sock *sk) 452 { 453 struct udp_sock *up = udp_sk(sk); 454 struct inet_sock *inet = inet_sk(sk); 455 struct flowi *fl = &inet->cork.fl; 456 struct sk_buff *skb; 457 struct udphdr *uh; 458 int err = 0; 459 __wsum csum = 0; 460 461 /* Grab the skbuff where UDP header space exists. */ 462 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) 463 goto out; 464 465 /* 466 * Create a UDP header 467 */ 468 uh = skb->h.uh; 469 uh->source = fl->fl_ip_sport; 470 uh->dest = fl->fl_ip_dport; 471 uh->len = htons(up->len); 472 uh->check = 0; 473 474 if (up->pcflag) /* UDP-Lite */ 475 csum = udplite_csum_outgoing(sk, skb); 476 477 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ 478 479 skb->ip_summed = CHECKSUM_NONE; 480 goto send; 481 482 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 483 484 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len); 485 goto send; 486 487 } else /* `normal' UDP */ 488 csum = udp_csum_outgoing(sk, skb); 489 490 /* add protocol-dependent pseudo-header */ 491 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len, 492 sk->sk_protocol, csum ); 493 if (uh->check == 0) 494 uh->check = CSUM_MANGLED_0; 495 496 send: 497 err = ip_push_pending_frames(sk); 498 out: 499 up->len = 0; 500 up->pending = 0; 501 return err; 502 } 503 504 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 505 size_t len) 506 { 507 struct inet_sock *inet = inet_sk(sk); 508 struct udp_sock *up = udp_sk(sk); 509 int ulen = len; 510 struct ipcm_cookie ipc; 511 struct rtable *rt = NULL; 512 int free = 0; 513 int connected = 0; 514 __be32 daddr, faddr, saddr; 515 __be16 dport; 516 u8 tos; 517 int err, is_udplite = up->pcflag; 518 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 519 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 520 521 if (len > 0xFFFF) 522 return -EMSGSIZE; 523 524 /* 525 * Check the flags. 526 */ 527 528 if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */ 529 return -EOPNOTSUPP; 530 531 ipc.opt = NULL; 532 533 if (up->pending) { 534 /* 535 * There are pending frames. 536 * The socket lock must be held while it's corked. 537 */ 538 lock_sock(sk); 539 if (likely(up->pending)) { 540 if (unlikely(up->pending != AF_INET)) { 541 release_sock(sk); 542 return -EINVAL; 543 } 544 goto do_append_data; 545 } 546 release_sock(sk); 547 } 548 ulen += sizeof(struct udphdr); 549 550 /* 551 * Get and verify the address. 552 */ 553 if (msg->msg_name) { 554 struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name; 555 if (msg->msg_namelen < sizeof(*usin)) 556 return -EINVAL; 557 if (usin->sin_family != AF_INET) { 558 if (usin->sin_family != AF_UNSPEC) 559 return -EAFNOSUPPORT; 560 } 561 562 daddr = usin->sin_addr.s_addr; 563 dport = usin->sin_port; 564 if (dport == 0) 565 return -EINVAL; 566 } else { 567 if (sk->sk_state != TCP_ESTABLISHED) 568 return -EDESTADDRREQ; 569 daddr = inet->daddr; 570 dport = inet->dport; 571 /* Open fast path for connected socket. 572 Route will not be used, if at least one option is set. 573 */ 574 connected = 1; 575 } 576 ipc.addr = inet->saddr; 577 578 ipc.oif = sk->sk_bound_dev_if; 579 if (msg->msg_controllen) { 580 err = ip_cmsg_send(msg, &ipc); 581 if (err) 582 return err; 583 if (ipc.opt) 584 free = 1; 585 connected = 0; 586 } 587 if (!ipc.opt) 588 ipc.opt = inet->opt; 589 590 saddr = ipc.addr; 591 ipc.addr = faddr = daddr; 592 593 if (ipc.opt && ipc.opt->srr) { 594 if (!daddr) 595 return -EINVAL; 596 faddr = ipc.opt->faddr; 597 connected = 0; 598 } 599 tos = RT_TOS(inet->tos); 600 if (sock_flag(sk, SOCK_LOCALROUTE) || 601 (msg->msg_flags & MSG_DONTROUTE) || 602 (ipc.opt && ipc.opt->is_strictroute)) { 603 tos |= RTO_ONLINK; 604 connected = 0; 605 } 606 607 if (MULTICAST(daddr)) { 608 if (!ipc.oif) 609 ipc.oif = inet->mc_index; 610 if (!saddr) 611 saddr = inet->mc_addr; 612 connected = 0; 613 } 614 615 if (connected) 616 rt = (struct rtable*)sk_dst_check(sk, 0); 617 618 if (rt == NULL) { 619 struct flowi fl = { .oif = ipc.oif, 620 .nl_u = { .ip4_u = 621 { .daddr = faddr, 622 .saddr = saddr, 623 .tos = tos } }, 624 .proto = sk->sk_protocol, 625 .uli_u = { .ports = 626 { .sport = inet->sport, 627 .dport = dport } } }; 628 security_sk_classify_flow(sk, &fl); 629 err = ip_route_output_flow(&rt, &fl, sk, !(msg->msg_flags&MSG_DONTWAIT)); 630 if (err) 631 goto out; 632 633 err = -EACCES; 634 if ((rt->rt_flags & RTCF_BROADCAST) && 635 !sock_flag(sk, SOCK_BROADCAST)) 636 goto out; 637 if (connected) 638 sk_dst_set(sk, dst_clone(&rt->u.dst)); 639 } 640 641 if (msg->msg_flags&MSG_CONFIRM) 642 goto do_confirm; 643 back_from_confirm: 644 645 saddr = rt->rt_src; 646 if (!ipc.addr) 647 daddr = ipc.addr = rt->rt_dst; 648 649 lock_sock(sk); 650 if (unlikely(up->pending)) { 651 /* The socket is already corked while preparing it. */ 652 /* ... which is an evident application bug. --ANK */ 653 release_sock(sk); 654 655 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n"); 656 err = -EINVAL; 657 goto out; 658 } 659 /* 660 * Now cork the socket to pend data. 661 */ 662 inet->cork.fl.fl4_dst = daddr; 663 inet->cork.fl.fl_ip_dport = dport; 664 inet->cork.fl.fl4_src = saddr; 665 inet->cork.fl.fl_ip_sport = inet->sport; 666 up->pending = AF_INET; 667 668 do_append_data: 669 up->len += ulen; 670 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 671 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen, 672 sizeof(struct udphdr), &ipc, rt, 673 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 674 if (err) 675 udp_flush_pending_frames(sk); 676 else if (!corkreq) 677 err = udp_push_pending_frames(sk); 678 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 679 up->pending = 0; 680 release_sock(sk); 681 682 out: 683 ip_rt_put(rt); 684 if (free) 685 kfree(ipc.opt); 686 if (!err) { 687 UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite); 688 return len; 689 } 690 /* 691 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 692 * ENOBUFS might not be good (it's not tunable per se), but otherwise 693 * we don't have a good statistic (IpOutDiscards but it can be too many 694 * things). We could add another new stat but at least for now that 695 * seems like overkill. 696 */ 697 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 698 UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite); 699 } 700 return err; 701 702 do_confirm: 703 dst_confirm(&rt->u.dst); 704 if (!(msg->msg_flags&MSG_PROBE) || len) 705 goto back_from_confirm; 706 err = 0; 707 goto out; 708 } 709 710 int udp_sendpage(struct sock *sk, struct page *page, int offset, 711 size_t size, int flags) 712 { 713 struct udp_sock *up = udp_sk(sk); 714 int ret; 715 716 if (!up->pending) { 717 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 718 719 /* Call udp_sendmsg to specify destination address which 720 * sendpage interface can't pass. 721 * This will succeed only when the socket is connected. 722 */ 723 ret = udp_sendmsg(NULL, sk, &msg, 0); 724 if (ret < 0) 725 return ret; 726 } 727 728 lock_sock(sk); 729 730 if (unlikely(!up->pending)) { 731 release_sock(sk); 732 733 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n"); 734 return -EINVAL; 735 } 736 737 ret = ip_append_page(sk, page, offset, size, flags); 738 if (ret == -EOPNOTSUPP) { 739 release_sock(sk); 740 return sock_no_sendpage(sk->sk_socket, page, offset, 741 size, flags); 742 } 743 if (ret < 0) { 744 udp_flush_pending_frames(sk); 745 goto out; 746 } 747 748 up->len += size; 749 if (!(up->corkflag || (flags&MSG_MORE))) 750 ret = udp_push_pending_frames(sk); 751 if (!ret) 752 ret = size; 753 out: 754 release_sock(sk); 755 return ret; 756 } 757 758 /* 759 * IOCTL requests applicable to the UDP protocol 760 */ 761 762 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 763 { 764 switch(cmd) 765 { 766 case SIOCOUTQ: 767 { 768 int amount = atomic_read(&sk->sk_wmem_alloc); 769 return put_user(amount, (int __user *)arg); 770 } 771 772 case SIOCINQ: 773 { 774 struct sk_buff *skb; 775 unsigned long amount; 776 777 amount = 0; 778 spin_lock_bh(&sk->sk_receive_queue.lock); 779 skb = skb_peek(&sk->sk_receive_queue); 780 if (skb != NULL) { 781 /* 782 * We will only return the amount 783 * of this packet since that is all 784 * that will be read. 785 */ 786 amount = skb->len - sizeof(struct udphdr); 787 } 788 spin_unlock_bh(&sk->sk_receive_queue.lock); 789 return put_user(amount, (int __user *)arg); 790 } 791 792 default: 793 return -ENOIOCTLCMD; 794 } 795 return(0); 796 } 797 798 /* 799 * This should be easy, if there is something there we 800 * return it, otherwise we block. 801 */ 802 803 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 804 size_t len, int noblock, int flags, int *addr_len) 805 { 806 struct inet_sock *inet = inet_sk(sk); 807 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 808 struct sk_buff *skb; 809 int copied, err, copy_only, is_udplite = IS_UDPLITE(sk); 810 811 /* 812 * Check any passed addresses 813 */ 814 if (addr_len) 815 *addr_len=sizeof(*sin); 816 817 if (flags & MSG_ERRQUEUE) 818 return ip_recv_error(sk, msg, len); 819 820 try_again: 821 skb = skb_recv_datagram(sk, flags, noblock, &err); 822 if (!skb) 823 goto out; 824 825 copied = skb->len - sizeof(struct udphdr); 826 if (copied > len) { 827 copied = len; 828 msg->msg_flags |= MSG_TRUNC; 829 } 830 831 /* 832 * Decide whether to checksum and/or copy data. 833 * 834 * UDP: checksum may have been computed in HW, 835 * (re-)compute it if message is truncated. 836 * UDP-Lite: always needs to checksum, no HW support. 837 */ 838 copy_only = (skb->ip_summed==CHECKSUM_UNNECESSARY); 839 840 if (is_udplite || (!copy_only && msg->msg_flags&MSG_TRUNC)) { 841 if (__udp_lib_checksum_complete(skb)) 842 goto csum_copy_err; 843 copy_only = 1; 844 } 845 846 if (copy_only) 847 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), 848 msg->msg_iov, copied ); 849 else { 850 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); 851 852 if (err == -EINVAL) 853 goto csum_copy_err; 854 } 855 856 if (err) 857 goto out_free; 858 859 sock_recv_timestamp(msg, sk, skb); 860 861 /* Copy the address. */ 862 if (sin) 863 { 864 sin->sin_family = AF_INET; 865 sin->sin_port = skb->h.uh->source; 866 sin->sin_addr.s_addr = skb->nh.iph->saddr; 867 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 868 } 869 if (inet->cmsg_flags) 870 ip_cmsg_recv(msg, skb); 871 872 err = copied; 873 if (flags & MSG_TRUNC) 874 err = skb->len - sizeof(struct udphdr); 875 876 out_free: 877 skb_free_datagram(sk, skb); 878 out: 879 return err; 880 881 csum_copy_err: 882 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite); 883 884 skb_kill_datagram(sk, skb, flags); 885 886 if (noblock) 887 return -EAGAIN; 888 goto try_again; 889 } 890 891 892 int udp_disconnect(struct sock *sk, int flags) 893 { 894 struct inet_sock *inet = inet_sk(sk); 895 /* 896 * 1003.1g - break association. 897 */ 898 899 sk->sk_state = TCP_CLOSE; 900 inet->daddr = 0; 901 inet->dport = 0; 902 sk->sk_bound_dev_if = 0; 903 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 904 inet_reset_saddr(sk); 905 906 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 907 sk->sk_prot->unhash(sk); 908 inet->sport = 0; 909 } 910 sk_dst_reset(sk); 911 return 0; 912 } 913 914 /* return: 915 * 1 if the the UDP system should process it 916 * 0 if we should drop this packet 917 * -1 if it should get processed by xfrm4_rcv_encap 918 */ 919 static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb) 920 { 921 #ifndef CONFIG_XFRM 922 return 1; 923 #else 924 struct udp_sock *up = udp_sk(sk); 925 struct udphdr *uh; 926 struct iphdr *iph; 927 int iphlen, len; 928 929 __u8 *udpdata; 930 __be32 *udpdata32; 931 __u16 encap_type = up->encap_type; 932 933 /* if we're overly short, let UDP handle it */ 934 len = skb->len - sizeof(struct udphdr); 935 if (len <= 0) 936 return 1; 937 938 /* if this is not encapsulated socket, then just return now */ 939 if (!encap_type) 940 return 1; 941 942 /* If this is a paged skb, make sure we pull up 943 * whatever data we need to look at. */ 944 if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8))) 945 return 1; 946 947 /* Now we can get the pointers */ 948 uh = skb->h.uh; 949 udpdata = (__u8 *)uh + sizeof(struct udphdr); 950 udpdata32 = (__be32 *)udpdata; 951 952 switch (encap_type) { 953 default: 954 case UDP_ENCAP_ESPINUDP: 955 /* Check if this is a keepalive packet. If so, eat it. */ 956 if (len == 1 && udpdata[0] == 0xff) { 957 return 0; 958 } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0 ) { 959 /* ESP Packet without Non-ESP header */ 960 len = sizeof(struct udphdr); 961 } else 962 /* Must be an IKE packet.. pass it through */ 963 return 1; 964 break; 965 case UDP_ENCAP_ESPINUDP_NON_IKE: 966 /* Check if this is a keepalive packet. If so, eat it. */ 967 if (len == 1 && udpdata[0] == 0xff) { 968 return 0; 969 } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) && 970 udpdata32[0] == 0 && udpdata32[1] == 0) { 971 972 /* ESP Packet with Non-IKE marker */ 973 len = sizeof(struct udphdr) + 2 * sizeof(u32); 974 } else 975 /* Must be an IKE packet.. pass it through */ 976 return 1; 977 break; 978 } 979 980 /* At this point we are sure that this is an ESPinUDP packet, 981 * so we need to remove 'len' bytes from the packet (the UDP 982 * header and optional ESP marker bytes) and then modify the 983 * protocol to ESP, and then call into the transform receiver. 984 */ 985 if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 986 return 0; 987 988 /* Now we can update and verify the packet length... */ 989 iph = skb->nh.iph; 990 iphlen = iph->ihl << 2; 991 iph->tot_len = htons(ntohs(iph->tot_len) - len); 992 if (skb->len < iphlen + len) { 993 /* packet is too small!?! */ 994 return 0; 995 } 996 997 /* pull the data buffer up to the ESP header and set the 998 * transport header to point to ESP. Keep UDP on the stack 999 * for later. 1000 */ 1001 skb->h.raw = skb_pull(skb, len); 1002 1003 /* modify the protocol (it's ESP!) */ 1004 iph->protocol = IPPROTO_ESP; 1005 1006 /* and let the caller know to send this into the ESP processor... */ 1007 return -1; 1008 #endif 1009 } 1010 1011 /* returns: 1012 * -1: error 1013 * 0: success 1014 * >0: "udp encap" protocol resubmission 1015 * 1016 * Note that in the success and error cases, the skb is assumed to 1017 * have either been requeued or freed. 1018 */ 1019 int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) 1020 { 1021 struct udp_sock *up = udp_sk(sk); 1022 int rc; 1023 1024 /* 1025 * Charge it to the socket, dropping if the queue is full. 1026 */ 1027 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1028 goto drop; 1029 nf_reset(skb); 1030 1031 if (up->encap_type) { 1032 /* 1033 * This is an encapsulation socket, so let's see if this is 1034 * an encapsulated packet. 1035 * If it's a keepalive packet, then just eat it. 1036 * If it's an encapsulateed packet, then pass it to the 1037 * IPsec xfrm input and return the response 1038 * appropriately. Otherwise, just fall through and 1039 * pass this up the UDP socket. 1040 */ 1041 int ret; 1042 1043 ret = udp_encap_rcv(sk, skb); 1044 if (ret == 0) { 1045 /* Eat the packet .. */ 1046 kfree_skb(skb); 1047 return 0; 1048 } 1049 if (ret < 0) { 1050 /* process the ESP packet */ 1051 ret = xfrm4_rcv_encap(skb, up->encap_type); 1052 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag); 1053 return -ret; 1054 } 1055 /* FALLTHROUGH -- it's a UDP Packet */ 1056 } 1057 1058 /* 1059 * UDP-Lite specific tests, ignored on UDP sockets 1060 */ 1061 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1062 1063 /* 1064 * MIB statistics other than incrementing the error count are 1065 * disabled for the following two types of errors: these depend 1066 * on the application settings, not on the functioning of the 1067 * protocol stack as such. 1068 * 1069 * RFC 3828 here recommends (sec 3.3): "There should also be a 1070 * way ... to ... at least let the receiving application block 1071 * delivery of packets with coverage values less than a value 1072 * provided by the application." 1073 */ 1074 if (up->pcrlen == 0) { /* full coverage was set */ 1075 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage " 1076 "%d while full coverage %d requested\n", 1077 UDP_SKB_CB(skb)->cscov, skb->len); 1078 goto drop; 1079 } 1080 /* The next case involves violating the min. coverage requested 1081 * by the receiver. This is subtle: if receiver wants x and x is 1082 * greater than the buffersize/MTU then receiver will complain 1083 * that it wants x while sender emits packets of smaller size y. 1084 * Therefore the above ...()->partial_cov statement is essential. 1085 */ 1086 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1087 LIMIT_NETDEBUG(KERN_WARNING 1088 "UDPLITE: coverage %d too small, need min %d\n", 1089 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1090 goto drop; 1091 } 1092 } 1093 1094 if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) { 1095 if (__udp_lib_checksum_complete(skb)) 1096 goto drop; 1097 skb->ip_summed = CHECKSUM_UNNECESSARY; 1098 } 1099 1100 if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) { 1101 /* Note that an ENOMEM error is charged twice */ 1102 if (rc == -ENOMEM) 1103 UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag); 1104 goto drop; 1105 } 1106 1107 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag); 1108 return 0; 1109 1110 drop: 1111 UDP_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag); 1112 kfree_skb(skb); 1113 return -1; 1114 } 1115 1116 /* 1117 * Multicasts and broadcasts go to each listener. 1118 * 1119 * Note: called only from the BH handler context, 1120 * so we don't need to lock the hashes. 1121 */ 1122 static int __udp4_lib_mcast_deliver(struct sk_buff *skb, 1123 struct udphdr *uh, 1124 __be32 saddr, __be32 daddr, 1125 struct hlist_head udptable[]) 1126 { 1127 struct sock *sk; 1128 int dif; 1129 1130 read_lock(&udp_hash_lock); 1131 sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]); 1132 dif = skb->dev->ifindex; 1133 sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif); 1134 if (sk) { 1135 struct sock *sknext = NULL; 1136 1137 do { 1138 struct sk_buff *skb1 = skb; 1139 1140 sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr, 1141 uh->source, saddr, dif); 1142 if(sknext) 1143 skb1 = skb_clone(skb, GFP_ATOMIC); 1144 1145 if(skb1) { 1146 int ret = udp_queue_rcv_skb(sk, skb1); 1147 if (ret > 0) 1148 /* we should probably re-process instead 1149 * of dropping packets here. */ 1150 kfree_skb(skb1); 1151 } 1152 sk = sknext; 1153 } while(sknext); 1154 } else 1155 kfree_skb(skb); 1156 read_unlock(&udp_hash_lock); 1157 return 0; 1158 } 1159 1160 /* Initialize UDP checksum. If exited with zero value (success), 1161 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1162 * Otherwise, csum completion requires chacksumming packet body, 1163 * including udp header and folding it to skb->csum. 1164 */ 1165 static inline void udp4_csum_init(struct sk_buff *skb, struct udphdr *uh) 1166 { 1167 if (uh->check == 0) { 1168 skb->ip_summed = CHECKSUM_UNNECESSARY; 1169 } else if (skb->ip_summed == CHECKSUM_COMPLETE) { 1170 if (!csum_tcpudp_magic(skb->nh.iph->saddr, skb->nh.iph->daddr, 1171 skb->len, IPPROTO_UDP, skb->csum )) 1172 skb->ip_summed = CHECKSUM_UNNECESSARY; 1173 } 1174 if (skb->ip_summed != CHECKSUM_UNNECESSARY) 1175 skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr, 1176 skb->nh.iph->daddr, 1177 skb->len, IPPROTO_UDP, 0); 1178 /* Probably, we should checksum udp header (it should be in cache 1179 * in any case) and data in tiny packets (< rx copybreak). 1180 */ 1181 1182 /* UDP = UDP-Lite with a non-partial checksum coverage */ 1183 UDP_SKB_CB(skb)->partial_cov = 0; 1184 } 1185 1186 /* 1187 * All we need to do is get the socket, and then do a checksum. 1188 */ 1189 1190 int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[], 1191 int is_udplite) 1192 { 1193 struct sock *sk; 1194 struct udphdr *uh = skb->h.uh; 1195 unsigned short ulen; 1196 struct rtable *rt = (struct rtable*)skb->dst; 1197 __be32 saddr = skb->nh.iph->saddr; 1198 __be32 daddr = skb->nh.iph->daddr; 1199 1200 /* 1201 * Validate the packet. 1202 */ 1203 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1204 goto drop; /* No space for header. */ 1205 1206 ulen = ntohs(uh->len); 1207 if (ulen > skb->len) 1208 goto short_packet; 1209 1210 if(! is_udplite ) { /* UDP validates ulen. */ 1211 1212 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1213 goto short_packet; 1214 1215 udp4_csum_init(skb, uh); 1216 1217 } else { /* UDP-Lite validates cscov. */ 1218 if (udplite4_csum_init(skb, uh)) 1219 goto csum_error; 1220 } 1221 1222 if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1223 return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable); 1224 1225 sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest, 1226 skb->dev->ifindex, udptable ); 1227 1228 if (sk != NULL) { 1229 int ret = udp_queue_rcv_skb(sk, skb); 1230 sock_put(sk); 1231 1232 /* a return value > 0 means to resubmit the input, but 1233 * it wants the return to be -protocol, or 0 1234 */ 1235 if (ret > 0) 1236 return -ret; 1237 return 0; 1238 } 1239 1240 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1241 goto drop; 1242 nf_reset(skb); 1243 1244 /* No socket. Drop packet silently, if checksum is wrong */ 1245 if (udp_lib_checksum_complete(skb)) 1246 goto csum_error; 1247 1248 UDP_INC_STATS_BH(UDP_MIB_NOPORTS, is_udplite); 1249 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1250 1251 /* 1252 * Hmm. We got an UDP packet to a port to which we 1253 * don't wanna listen. Ignore it. 1254 */ 1255 kfree_skb(skb); 1256 return(0); 1257 1258 short_packet: 1259 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n", 1260 is_udplite? "-Lite" : "", 1261 NIPQUAD(saddr), 1262 ntohs(uh->source), 1263 ulen, 1264 skb->len, 1265 NIPQUAD(daddr), 1266 ntohs(uh->dest)); 1267 goto drop; 1268 1269 csum_error: 1270 /* 1271 * RFC1122: OK. Discards the bad packet silently (as far as 1272 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1273 */ 1274 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n", 1275 is_udplite? "-Lite" : "", 1276 NIPQUAD(saddr), 1277 ntohs(uh->source), 1278 NIPQUAD(daddr), 1279 ntohs(uh->dest), 1280 ulen); 1281 drop: 1282 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite); 1283 kfree_skb(skb); 1284 return(0); 1285 } 1286 1287 __inline__ int udp_rcv(struct sk_buff *skb) 1288 { 1289 return __udp4_lib_rcv(skb, udp_hash, 0); 1290 } 1291 1292 int udp_destroy_sock(struct sock *sk) 1293 { 1294 lock_sock(sk); 1295 udp_flush_pending_frames(sk); 1296 release_sock(sk); 1297 return 0; 1298 } 1299 1300 /* 1301 * Socket option code for UDP 1302 */ 1303 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 1304 char __user *optval, int optlen, 1305 int (*push_pending_frames)(struct sock *)) 1306 { 1307 struct udp_sock *up = udp_sk(sk); 1308 int val; 1309 int err = 0; 1310 1311 if(optlen<sizeof(int)) 1312 return -EINVAL; 1313 1314 if (get_user(val, (int __user *)optval)) 1315 return -EFAULT; 1316 1317 switch(optname) { 1318 case UDP_CORK: 1319 if (val != 0) { 1320 up->corkflag = 1; 1321 } else { 1322 up->corkflag = 0; 1323 lock_sock(sk); 1324 (*push_pending_frames)(sk); 1325 release_sock(sk); 1326 } 1327 break; 1328 1329 case UDP_ENCAP: 1330 switch (val) { 1331 case 0: 1332 case UDP_ENCAP_ESPINUDP: 1333 case UDP_ENCAP_ESPINUDP_NON_IKE: 1334 up->encap_type = val; 1335 break; 1336 default: 1337 err = -ENOPROTOOPT; 1338 break; 1339 } 1340 break; 1341 1342 /* 1343 * UDP-Lite's partial checksum coverage (RFC 3828). 1344 */ 1345 /* The sender sets actual checksum coverage length via this option. 1346 * The case coverage > packet length is handled by send module. */ 1347 case UDPLITE_SEND_CSCOV: 1348 if (!up->pcflag) /* Disable the option on UDP sockets */ 1349 return -ENOPROTOOPT; 1350 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 1351 val = 8; 1352 up->pcslen = val; 1353 up->pcflag |= UDPLITE_SEND_CC; 1354 break; 1355 1356 /* The receiver specifies a minimum checksum coverage value. To make 1357 * sense, this should be set to at least 8 (as done below). If zero is 1358 * used, this again means full checksum coverage. */ 1359 case UDPLITE_RECV_CSCOV: 1360 if (!up->pcflag) /* Disable the option on UDP sockets */ 1361 return -ENOPROTOOPT; 1362 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 1363 val = 8; 1364 up->pcrlen = val; 1365 up->pcflag |= UDPLITE_RECV_CC; 1366 break; 1367 1368 default: 1369 err = -ENOPROTOOPT; 1370 break; 1371 }; 1372 1373 return err; 1374 } 1375 1376 int udp_setsockopt(struct sock *sk, int level, int optname, 1377 char __user *optval, int optlen) 1378 { 1379 if (level == SOL_UDP || level == SOL_UDPLITE) 1380 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1381 udp_push_pending_frames); 1382 return ip_setsockopt(sk, level, optname, optval, optlen); 1383 } 1384 1385 #ifdef CONFIG_COMPAT 1386 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 1387 char __user *optval, int optlen) 1388 { 1389 if (level == SOL_UDP || level == SOL_UDPLITE) 1390 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1391 udp_push_pending_frames); 1392 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 1393 } 1394 #endif 1395 1396 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 1397 char __user *optval, int __user *optlen) 1398 { 1399 struct udp_sock *up = udp_sk(sk); 1400 int val, len; 1401 1402 if(get_user(len,optlen)) 1403 return -EFAULT; 1404 1405 len = min_t(unsigned int, len, sizeof(int)); 1406 1407 if(len < 0) 1408 return -EINVAL; 1409 1410 switch(optname) { 1411 case UDP_CORK: 1412 val = up->corkflag; 1413 break; 1414 1415 case UDP_ENCAP: 1416 val = up->encap_type; 1417 break; 1418 1419 /* The following two cannot be changed on UDP sockets, the return is 1420 * always 0 (which corresponds to the full checksum coverage of UDP). */ 1421 case UDPLITE_SEND_CSCOV: 1422 val = up->pcslen; 1423 break; 1424 1425 case UDPLITE_RECV_CSCOV: 1426 val = up->pcrlen; 1427 break; 1428 1429 default: 1430 return -ENOPROTOOPT; 1431 }; 1432 1433 if(put_user(len, optlen)) 1434 return -EFAULT; 1435 if(copy_to_user(optval, &val,len)) 1436 return -EFAULT; 1437 return 0; 1438 } 1439 1440 int udp_getsockopt(struct sock *sk, int level, int optname, 1441 char __user *optval, int __user *optlen) 1442 { 1443 if (level == SOL_UDP || level == SOL_UDPLITE) 1444 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1445 return ip_getsockopt(sk, level, optname, optval, optlen); 1446 } 1447 1448 #ifdef CONFIG_COMPAT 1449 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 1450 char __user *optval, int __user *optlen) 1451 { 1452 if (level == SOL_UDP || level == SOL_UDPLITE) 1453 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1454 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 1455 } 1456 #endif 1457 /** 1458 * udp_poll - wait for a UDP event. 1459 * @file - file struct 1460 * @sock - socket 1461 * @wait - poll table 1462 * 1463 * This is same as datagram poll, except for the special case of 1464 * blocking sockets. If application is using a blocking fd 1465 * and a packet with checksum error is in the queue; 1466 * then it could get return from select indicating data available 1467 * but then block when reading it. Add special case code 1468 * to work around these arguably broken applications. 1469 */ 1470 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 1471 { 1472 unsigned int mask = datagram_poll(file, sock, wait); 1473 struct sock *sk = sock->sk; 1474 int is_lite = IS_UDPLITE(sk); 1475 1476 /* Check for false positives due to checksum errors */ 1477 if ( (mask & POLLRDNORM) && 1478 !(file->f_flags & O_NONBLOCK) && 1479 !(sk->sk_shutdown & RCV_SHUTDOWN)){ 1480 struct sk_buff_head *rcvq = &sk->sk_receive_queue; 1481 struct sk_buff *skb; 1482 1483 spin_lock_bh(&rcvq->lock); 1484 while ((skb = skb_peek(rcvq)) != NULL) { 1485 if (udp_lib_checksum_complete(skb)) { 1486 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite); 1487 __skb_unlink(skb, rcvq); 1488 kfree_skb(skb); 1489 } else { 1490 skb->ip_summed = CHECKSUM_UNNECESSARY; 1491 break; 1492 } 1493 } 1494 spin_unlock_bh(&rcvq->lock); 1495 1496 /* nothing to see, move along */ 1497 if (skb == NULL) 1498 mask &= ~(POLLIN | POLLRDNORM); 1499 } 1500 1501 return mask; 1502 1503 } 1504 1505 struct proto udp_prot = { 1506 .name = "UDP", 1507 .owner = THIS_MODULE, 1508 .close = udp_lib_close, 1509 .connect = ip4_datagram_connect, 1510 .disconnect = udp_disconnect, 1511 .ioctl = udp_ioctl, 1512 .destroy = udp_destroy_sock, 1513 .setsockopt = udp_setsockopt, 1514 .getsockopt = udp_getsockopt, 1515 .sendmsg = udp_sendmsg, 1516 .recvmsg = udp_recvmsg, 1517 .sendpage = udp_sendpage, 1518 .backlog_rcv = udp_queue_rcv_skb, 1519 .hash = udp_lib_hash, 1520 .unhash = udp_lib_unhash, 1521 .get_port = udp_v4_get_port, 1522 .obj_size = sizeof(struct udp_sock), 1523 #ifdef CONFIG_COMPAT 1524 .compat_setsockopt = compat_udp_setsockopt, 1525 .compat_getsockopt = compat_udp_getsockopt, 1526 #endif 1527 }; 1528 1529 /* ------------------------------------------------------------------------ */ 1530 #ifdef CONFIG_PROC_FS 1531 1532 static struct sock *udp_get_first(struct seq_file *seq) 1533 { 1534 struct sock *sk; 1535 struct udp_iter_state *state = seq->private; 1536 1537 for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) { 1538 struct hlist_node *node; 1539 sk_for_each(sk, node, state->hashtable + state->bucket) { 1540 if (sk->sk_family == state->family) 1541 goto found; 1542 } 1543 } 1544 sk = NULL; 1545 found: 1546 return sk; 1547 } 1548 1549 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 1550 { 1551 struct udp_iter_state *state = seq->private; 1552 1553 do { 1554 sk = sk_next(sk); 1555 try_again: 1556 ; 1557 } while (sk && sk->sk_family != state->family); 1558 1559 if (!sk && ++state->bucket < UDP_HTABLE_SIZE) { 1560 sk = sk_head(state->hashtable + state->bucket); 1561 goto try_again; 1562 } 1563 return sk; 1564 } 1565 1566 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 1567 { 1568 struct sock *sk = udp_get_first(seq); 1569 1570 if (sk) 1571 while(pos && (sk = udp_get_next(seq, sk)) != NULL) 1572 --pos; 1573 return pos ? NULL : sk; 1574 } 1575 1576 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 1577 { 1578 read_lock(&udp_hash_lock); 1579 return *pos ? udp_get_idx(seq, *pos-1) : (void *)1; 1580 } 1581 1582 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1583 { 1584 struct sock *sk; 1585 1586 if (v == (void *)1) 1587 sk = udp_get_idx(seq, 0); 1588 else 1589 sk = udp_get_next(seq, v); 1590 1591 ++*pos; 1592 return sk; 1593 } 1594 1595 static void udp_seq_stop(struct seq_file *seq, void *v) 1596 { 1597 read_unlock(&udp_hash_lock); 1598 } 1599 1600 static int udp_seq_open(struct inode *inode, struct file *file) 1601 { 1602 struct udp_seq_afinfo *afinfo = PDE(inode)->data; 1603 struct seq_file *seq; 1604 int rc = -ENOMEM; 1605 struct udp_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL); 1606 1607 if (!s) 1608 goto out; 1609 s->family = afinfo->family; 1610 s->hashtable = afinfo->hashtable; 1611 s->seq_ops.start = udp_seq_start; 1612 s->seq_ops.next = udp_seq_next; 1613 s->seq_ops.show = afinfo->seq_show; 1614 s->seq_ops.stop = udp_seq_stop; 1615 1616 rc = seq_open(file, &s->seq_ops); 1617 if (rc) 1618 goto out_kfree; 1619 1620 seq = file->private_data; 1621 seq->private = s; 1622 out: 1623 return rc; 1624 out_kfree: 1625 kfree(s); 1626 goto out; 1627 } 1628 1629 /* ------------------------------------------------------------------------ */ 1630 int udp_proc_register(struct udp_seq_afinfo *afinfo) 1631 { 1632 struct proc_dir_entry *p; 1633 int rc = 0; 1634 1635 if (!afinfo) 1636 return -EINVAL; 1637 afinfo->seq_fops->owner = afinfo->owner; 1638 afinfo->seq_fops->open = udp_seq_open; 1639 afinfo->seq_fops->read = seq_read; 1640 afinfo->seq_fops->llseek = seq_lseek; 1641 afinfo->seq_fops->release = seq_release_private; 1642 1643 p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops); 1644 if (p) 1645 p->data = afinfo; 1646 else 1647 rc = -ENOMEM; 1648 return rc; 1649 } 1650 1651 void udp_proc_unregister(struct udp_seq_afinfo *afinfo) 1652 { 1653 if (!afinfo) 1654 return; 1655 proc_net_remove(afinfo->name); 1656 memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops)); 1657 } 1658 1659 /* ------------------------------------------------------------------------ */ 1660 static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket) 1661 { 1662 struct inet_sock *inet = inet_sk(sp); 1663 __be32 dest = inet->daddr; 1664 __be32 src = inet->rcv_saddr; 1665 __u16 destp = ntohs(inet->dport); 1666 __u16 srcp = ntohs(inet->sport); 1667 1668 sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" 1669 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p", 1670 bucket, src, srcp, dest, destp, sp->sk_state, 1671 atomic_read(&sp->sk_wmem_alloc), 1672 atomic_read(&sp->sk_rmem_alloc), 1673 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), 1674 atomic_read(&sp->sk_refcnt), sp); 1675 } 1676 1677 int udp4_seq_show(struct seq_file *seq, void *v) 1678 { 1679 if (v == SEQ_START_TOKEN) 1680 seq_printf(seq, "%-127s\n", 1681 " sl local_address rem_address st tx_queue " 1682 "rx_queue tr tm->when retrnsmt uid timeout " 1683 "inode"); 1684 else { 1685 char tmpbuf[129]; 1686 struct udp_iter_state *state = seq->private; 1687 1688 udp4_format_sock(v, tmpbuf, state->bucket); 1689 seq_printf(seq, "%-127s\n", tmpbuf); 1690 } 1691 return 0; 1692 } 1693 1694 /* ------------------------------------------------------------------------ */ 1695 static struct file_operations udp4_seq_fops; 1696 static struct udp_seq_afinfo udp4_seq_afinfo = { 1697 .owner = THIS_MODULE, 1698 .name = "udp", 1699 .family = AF_INET, 1700 .hashtable = udp_hash, 1701 .seq_show = udp4_seq_show, 1702 .seq_fops = &udp4_seq_fops, 1703 }; 1704 1705 int __init udp4_proc_init(void) 1706 { 1707 return udp_proc_register(&udp4_seq_afinfo); 1708 } 1709 1710 void udp4_proc_exit(void) 1711 { 1712 udp_proc_unregister(&udp4_seq_afinfo); 1713 } 1714 #endif /* CONFIG_PROC_FS */ 1715 1716 EXPORT_SYMBOL(udp_disconnect); 1717 EXPORT_SYMBOL(udp_hash); 1718 EXPORT_SYMBOL(udp_hash_lock); 1719 EXPORT_SYMBOL(udp_ioctl); 1720 EXPORT_SYMBOL(udp_get_port); 1721 EXPORT_SYMBOL(udp_prot); 1722 EXPORT_SYMBOL(udp_sendmsg); 1723 EXPORT_SYMBOL(udp_lib_getsockopt); 1724 EXPORT_SYMBOL(udp_lib_setsockopt); 1725 EXPORT_SYMBOL(udp_poll); 1726 1727 #ifdef CONFIG_PROC_FS 1728 EXPORT_SYMBOL(udp_proc_register); 1729 EXPORT_SYMBOL(udp_proc_unregister); 1730 #endif 1731