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 goto next; 171 } 172 best_size_so_far = size; 173 best = result; 174 next: 175 ; 176 } 177 result = best; 178 for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) { 179 if (result > sysctl_local_port_range[1]) 180 result = sysctl_local_port_range[0] 181 + ((result - sysctl_local_port_range[0]) & 182 (UDP_HTABLE_SIZE - 1)); 183 if (! __udp_lib_lport_inuse(result, udptable)) 184 break; 185 } 186 if (i >= (1 << 16) / UDP_HTABLE_SIZE) 187 goto fail; 188 gotit: 189 *port_rover = snum = result; 190 } else { 191 head = &udptable[snum & (UDP_HTABLE_SIZE - 1)]; 192 193 sk_for_each(sk2, node, head) 194 if (inet_sk(sk2)->num == snum && 195 sk2 != sk && 196 (!sk2->sk_reuse || !sk->sk_reuse) && 197 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if 198 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 199 (*saddr_comp)(sk, sk2) ) 200 goto fail; 201 } 202 inet_sk(sk)->num = snum; 203 if (sk_unhashed(sk)) { 204 head = &udptable[snum & (UDP_HTABLE_SIZE - 1)]; 205 sk_add_node(sk, head); 206 sock_prot_inc_use(sk->sk_prot); 207 } 208 error = 0; 209 fail: 210 write_unlock_bh(&udp_hash_lock); 211 return error; 212 } 213 214 __inline__ int udp_get_port(struct sock *sk, unsigned short snum, 215 int (*scmp)(const struct sock *, const struct sock *)) 216 { 217 return __udp_lib_get_port(sk, snum, udp_hash, &udp_port_rover, scmp); 218 } 219 220 inline int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 221 { 222 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 223 224 return ( !ipv6_only_sock(sk2) && 225 (!inet1->rcv_saddr || !inet2->rcv_saddr || 226 inet1->rcv_saddr == inet2->rcv_saddr )); 227 } 228 229 static inline int udp_v4_get_port(struct sock *sk, unsigned short snum) 230 { 231 return udp_get_port(sk, snum, ipv4_rcv_saddr_equal); 232 } 233 234 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 235 * harder than this. -DaveM 236 */ 237 static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport, 238 __be32 daddr, __be16 dport, 239 int dif, struct hlist_head udptable[]) 240 { 241 struct sock *sk, *result = NULL; 242 struct hlist_node *node; 243 unsigned short hnum = ntohs(dport); 244 int badness = -1; 245 246 read_lock(&udp_hash_lock); 247 sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) { 248 struct inet_sock *inet = inet_sk(sk); 249 250 if (inet->num == hnum && !ipv6_only_sock(sk)) { 251 int score = (sk->sk_family == PF_INET ? 1 : 0); 252 if (inet->rcv_saddr) { 253 if (inet->rcv_saddr != daddr) 254 continue; 255 score+=2; 256 } 257 if (inet->daddr) { 258 if (inet->daddr != saddr) 259 continue; 260 score+=2; 261 } 262 if (inet->dport) { 263 if (inet->dport != sport) 264 continue; 265 score+=2; 266 } 267 if (sk->sk_bound_dev_if) { 268 if (sk->sk_bound_dev_if != dif) 269 continue; 270 score+=2; 271 } 272 if(score == 9) { 273 result = sk; 274 break; 275 } else if(score > badness) { 276 result = sk; 277 badness = score; 278 } 279 } 280 } 281 if (result) 282 sock_hold(result); 283 read_unlock(&udp_hash_lock); 284 return result; 285 } 286 287 static inline struct sock *udp_v4_mcast_next(struct sock *sk, 288 __be16 loc_port, __be32 loc_addr, 289 __be16 rmt_port, __be32 rmt_addr, 290 int dif) 291 { 292 struct hlist_node *node; 293 struct sock *s = sk; 294 unsigned short hnum = ntohs(loc_port); 295 296 sk_for_each_from(s, node) { 297 struct inet_sock *inet = inet_sk(s); 298 299 if (inet->num != hnum || 300 (inet->daddr && inet->daddr != rmt_addr) || 301 (inet->dport != rmt_port && inet->dport) || 302 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) || 303 ipv6_only_sock(s) || 304 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) 305 continue; 306 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) 307 continue; 308 goto found; 309 } 310 s = NULL; 311 found: 312 return s; 313 } 314 315 /* 316 * This routine is called by the ICMP module when it gets some 317 * sort of error condition. If err < 0 then the socket should 318 * be closed and the error returned to the user. If err > 0 319 * it's just the icmp type << 8 | icmp code. 320 * Header points to the ip header of the error packet. We move 321 * on past this. Then (as it used to claim before adjustment) 322 * header points to the first 8 bytes of the udp header. We need 323 * to find the appropriate port. 324 */ 325 326 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[]) 327 { 328 struct inet_sock *inet; 329 struct iphdr *iph = (struct iphdr*)skb->data; 330 struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2)); 331 int type = skb->h.icmph->type; 332 int code = skb->h.icmph->code; 333 struct sock *sk; 334 int harderr; 335 int err; 336 337 sk = __udp4_lib_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, 338 skb->dev->ifindex, udptable ); 339 if (sk == NULL) { 340 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); 341 return; /* No socket for error */ 342 } 343 344 err = 0; 345 harderr = 0; 346 inet = inet_sk(sk); 347 348 switch (type) { 349 default: 350 case ICMP_TIME_EXCEEDED: 351 err = EHOSTUNREACH; 352 break; 353 case ICMP_SOURCE_QUENCH: 354 goto out; 355 case ICMP_PARAMETERPROB: 356 err = EPROTO; 357 harderr = 1; 358 break; 359 case ICMP_DEST_UNREACH: 360 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 361 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 362 err = EMSGSIZE; 363 harderr = 1; 364 break; 365 } 366 goto out; 367 } 368 err = EHOSTUNREACH; 369 if (code <= NR_ICMP_UNREACH) { 370 harderr = icmp_err_convert[code].fatal; 371 err = icmp_err_convert[code].errno; 372 } 373 break; 374 } 375 376 /* 377 * RFC1122: OK. Passes ICMP errors back to application, as per 378 * 4.1.3.3. 379 */ 380 if (!inet->recverr) { 381 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 382 goto out; 383 } else { 384 ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1)); 385 } 386 sk->sk_err = err; 387 sk->sk_error_report(sk); 388 out: 389 sock_put(sk); 390 } 391 392 __inline__ void udp_err(struct sk_buff *skb, u32 info) 393 { 394 return __udp4_lib_err(skb, info, udp_hash); 395 } 396 397 /* 398 * Throw away all pending data and cancel the corking. Socket is locked. 399 */ 400 static void udp_flush_pending_frames(struct sock *sk) 401 { 402 struct udp_sock *up = udp_sk(sk); 403 404 if (up->pending) { 405 up->len = 0; 406 up->pending = 0; 407 ip_flush_pending_frames(sk); 408 } 409 } 410 411 /** 412 * udp4_hwcsum_outgoing - handle outgoing HW checksumming 413 * @sk: socket we are sending on 414 * @skb: sk_buff containing the filled-in UDP header 415 * (checksum field must be zeroed out) 416 */ 417 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, 418 __be32 src, __be32 dst, int len ) 419 { 420 unsigned int offset; 421 struct udphdr *uh = skb->h.uh; 422 __wsum csum = 0; 423 424 if (skb_queue_len(&sk->sk_write_queue) == 1) { 425 /* 426 * Only one fragment on the socket. 427 */ 428 skb->csum_offset = offsetof(struct udphdr, check); 429 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0); 430 } else { 431 /* 432 * HW-checksum won't work as there are two or more 433 * fragments on the socket so that all csums of sk_buffs 434 * should be together 435 */ 436 offset = skb->h.raw - skb->data; 437 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); 438 439 skb->ip_summed = CHECKSUM_NONE; 440 441 skb_queue_walk(&sk->sk_write_queue, skb) { 442 csum = csum_add(csum, skb->csum); 443 } 444 445 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 446 if (uh->check == 0) 447 uh->check = CSUM_MANGLED_0; 448 } 449 } 450 451 /* 452 * Push out all pending data as one UDP datagram. Socket is locked. 453 */ 454 static int udp_push_pending_frames(struct sock *sk) 455 { 456 struct udp_sock *up = udp_sk(sk); 457 struct inet_sock *inet = inet_sk(sk); 458 struct flowi *fl = &inet->cork.fl; 459 struct sk_buff *skb; 460 struct udphdr *uh; 461 int err = 0; 462 __wsum csum = 0; 463 464 /* Grab the skbuff where UDP header space exists. */ 465 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) 466 goto out; 467 468 /* 469 * Create a UDP header 470 */ 471 uh = skb->h.uh; 472 uh->source = fl->fl_ip_sport; 473 uh->dest = fl->fl_ip_dport; 474 uh->len = htons(up->len); 475 uh->check = 0; 476 477 if (up->pcflag) /* UDP-Lite */ 478 csum = udplite_csum_outgoing(sk, skb); 479 480 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ 481 482 skb->ip_summed = CHECKSUM_NONE; 483 goto send; 484 485 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 486 487 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len); 488 goto send; 489 490 } else /* `normal' UDP */ 491 csum = udp_csum_outgoing(sk, skb); 492 493 /* add protocol-dependent pseudo-header */ 494 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len, 495 sk->sk_protocol, csum ); 496 if (uh->check == 0) 497 uh->check = CSUM_MANGLED_0; 498 499 send: 500 err = ip_push_pending_frames(sk); 501 out: 502 up->len = 0; 503 up->pending = 0; 504 return err; 505 } 506 507 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 508 size_t len) 509 { 510 struct inet_sock *inet = inet_sk(sk); 511 struct udp_sock *up = udp_sk(sk); 512 int ulen = len; 513 struct ipcm_cookie ipc; 514 struct rtable *rt = NULL; 515 int free = 0; 516 int connected = 0; 517 __be32 daddr, faddr, saddr; 518 __be16 dport; 519 u8 tos; 520 int err, is_udplite = up->pcflag; 521 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 522 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 523 524 if (len > 0xFFFF) 525 return -EMSGSIZE; 526 527 /* 528 * Check the flags. 529 */ 530 531 if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */ 532 return -EOPNOTSUPP; 533 534 ipc.opt = NULL; 535 536 if (up->pending) { 537 /* 538 * There are pending frames. 539 * The socket lock must be held while it's corked. 540 */ 541 lock_sock(sk); 542 if (likely(up->pending)) { 543 if (unlikely(up->pending != AF_INET)) { 544 release_sock(sk); 545 return -EINVAL; 546 } 547 goto do_append_data; 548 } 549 release_sock(sk); 550 } 551 ulen += sizeof(struct udphdr); 552 553 /* 554 * Get and verify the address. 555 */ 556 if (msg->msg_name) { 557 struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name; 558 if (msg->msg_namelen < sizeof(*usin)) 559 return -EINVAL; 560 if (usin->sin_family != AF_INET) { 561 if (usin->sin_family != AF_UNSPEC) 562 return -EAFNOSUPPORT; 563 } 564 565 daddr = usin->sin_addr.s_addr; 566 dport = usin->sin_port; 567 if (dport == 0) 568 return -EINVAL; 569 } else { 570 if (sk->sk_state != TCP_ESTABLISHED) 571 return -EDESTADDRREQ; 572 daddr = inet->daddr; 573 dport = inet->dport; 574 /* Open fast path for connected socket. 575 Route will not be used, if at least one option is set. 576 */ 577 connected = 1; 578 } 579 ipc.addr = inet->saddr; 580 581 ipc.oif = sk->sk_bound_dev_if; 582 if (msg->msg_controllen) { 583 err = ip_cmsg_send(msg, &ipc); 584 if (err) 585 return err; 586 if (ipc.opt) 587 free = 1; 588 connected = 0; 589 } 590 if (!ipc.opt) 591 ipc.opt = inet->opt; 592 593 saddr = ipc.addr; 594 ipc.addr = faddr = daddr; 595 596 if (ipc.opt && ipc.opt->srr) { 597 if (!daddr) 598 return -EINVAL; 599 faddr = ipc.opt->faddr; 600 connected = 0; 601 } 602 tos = RT_TOS(inet->tos); 603 if (sock_flag(sk, SOCK_LOCALROUTE) || 604 (msg->msg_flags & MSG_DONTROUTE) || 605 (ipc.opt && ipc.opt->is_strictroute)) { 606 tos |= RTO_ONLINK; 607 connected = 0; 608 } 609 610 if (MULTICAST(daddr)) { 611 if (!ipc.oif) 612 ipc.oif = inet->mc_index; 613 if (!saddr) 614 saddr = inet->mc_addr; 615 connected = 0; 616 } 617 618 if (connected) 619 rt = (struct rtable*)sk_dst_check(sk, 0); 620 621 if (rt == NULL) { 622 struct flowi fl = { .oif = ipc.oif, 623 .nl_u = { .ip4_u = 624 { .daddr = faddr, 625 .saddr = saddr, 626 .tos = tos } }, 627 .proto = sk->sk_protocol, 628 .uli_u = { .ports = 629 { .sport = inet->sport, 630 .dport = dport } } }; 631 security_sk_classify_flow(sk, &fl); 632 err = ip_route_output_flow(&rt, &fl, sk, !(msg->msg_flags&MSG_DONTWAIT)); 633 if (err) 634 goto out; 635 636 err = -EACCES; 637 if ((rt->rt_flags & RTCF_BROADCAST) && 638 !sock_flag(sk, SOCK_BROADCAST)) 639 goto out; 640 if (connected) 641 sk_dst_set(sk, dst_clone(&rt->u.dst)); 642 } 643 644 if (msg->msg_flags&MSG_CONFIRM) 645 goto do_confirm; 646 back_from_confirm: 647 648 saddr = rt->rt_src; 649 if (!ipc.addr) 650 daddr = ipc.addr = rt->rt_dst; 651 652 lock_sock(sk); 653 if (unlikely(up->pending)) { 654 /* The socket is already corked while preparing it. */ 655 /* ... which is an evident application bug. --ANK */ 656 release_sock(sk); 657 658 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n"); 659 err = -EINVAL; 660 goto out; 661 } 662 /* 663 * Now cork the socket to pend data. 664 */ 665 inet->cork.fl.fl4_dst = daddr; 666 inet->cork.fl.fl_ip_dport = dport; 667 inet->cork.fl.fl4_src = saddr; 668 inet->cork.fl.fl_ip_sport = inet->sport; 669 up->pending = AF_INET; 670 671 do_append_data: 672 up->len += ulen; 673 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 674 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen, 675 sizeof(struct udphdr), &ipc, rt, 676 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 677 if (err) 678 udp_flush_pending_frames(sk); 679 else if (!corkreq) 680 err = udp_push_pending_frames(sk); 681 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 682 up->pending = 0; 683 release_sock(sk); 684 685 out: 686 ip_rt_put(rt); 687 if (free) 688 kfree(ipc.opt); 689 if (!err) { 690 UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite); 691 return len; 692 } 693 /* 694 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 695 * ENOBUFS might not be good (it's not tunable per se), but otherwise 696 * we don't have a good statistic (IpOutDiscards but it can be too many 697 * things). We could add another new stat but at least for now that 698 * seems like overkill. 699 */ 700 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 701 UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite); 702 } 703 return err; 704 705 do_confirm: 706 dst_confirm(&rt->u.dst); 707 if (!(msg->msg_flags&MSG_PROBE) || len) 708 goto back_from_confirm; 709 err = 0; 710 goto out; 711 } 712 713 int udp_sendpage(struct sock *sk, struct page *page, int offset, 714 size_t size, int flags) 715 { 716 struct udp_sock *up = udp_sk(sk); 717 int ret; 718 719 if (!up->pending) { 720 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 721 722 /* Call udp_sendmsg to specify destination address which 723 * sendpage interface can't pass. 724 * This will succeed only when the socket is connected. 725 */ 726 ret = udp_sendmsg(NULL, sk, &msg, 0); 727 if (ret < 0) 728 return ret; 729 } 730 731 lock_sock(sk); 732 733 if (unlikely(!up->pending)) { 734 release_sock(sk); 735 736 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n"); 737 return -EINVAL; 738 } 739 740 ret = ip_append_page(sk, page, offset, size, flags); 741 if (ret == -EOPNOTSUPP) { 742 release_sock(sk); 743 return sock_no_sendpage(sk->sk_socket, page, offset, 744 size, flags); 745 } 746 if (ret < 0) { 747 udp_flush_pending_frames(sk); 748 goto out; 749 } 750 751 up->len += size; 752 if (!(up->corkflag || (flags&MSG_MORE))) 753 ret = udp_push_pending_frames(sk); 754 if (!ret) 755 ret = size; 756 out: 757 release_sock(sk); 758 return ret; 759 } 760 761 /* 762 * IOCTL requests applicable to the UDP protocol 763 */ 764 765 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 766 { 767 switch(cmd) 768 { 769 case SIOCOUTQ: 770 { 771 int amount = atomic_read(&sk->sk_wmem_alloc); 772 return put_user(amount, (int __user *)arg); 773 } 774 775 case SIOCINQ: 776 { 777 struct sk_buff *skb; 778 unsigned long amount; 779 780 amount = 0; 781 spin_lock_bh(&sk->sk_receive_queue.lock); 782 skb = skb_peek(&sk->sk_receive_queue); 783 if (skb != NULL) { 784 /* 785 * We will only return the amount 786 * of this packet since that is all 787 * that will be read. 788 */ 789 amount = skb->len - sizeof(struct udphdr); 790 } 791 spin_unlock_bh(&sk->sk_receive_queue.lock); 792 return put_user(amount, (int __user *)arg); 793 } 794 795 default: 796 return -ENOIOCTLCMD; 797 } 798 return(0); 799 } 800 801 /* 802 * This should be easy, if there is something there we 803 * return it, otherwise we block. 804 */ 805 806 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 807 size_t len, int noblock, int flags, int *addr_len) 808 { 809 struct inet_sock *inet = inet_sk(sk); 810 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 811 struct sk_buff *skb; 812 int copied, err, copy_only, is_udplite = IS_UDPLITE(sk); 813 814 /* 815 * Check any passed addresses 816 */ 817 if (addr_len) 818 *addr_len=sizeof(*sin); 819 820 if (flags & MSG_ERRQUEUE) 821 return ip_recv_error(sk, msg, len); 822 823 try_again: 824 skb = skb_recv_datagram(sk, flags, noblock, &err); 825 if (!skb) 826 goto out; 827 828 copied = skb->len - sizeof(struct udphdr); 829 if (copied > len) { 830 copied = len; 831 msg->msg_flags |= MSG_TRUNC; 832 } 833 834 /* 835 * Decide whether to checksum and/or copy data. 836 * 837 * UDP: checksum may have been computed in HW, 838 * (re-)compute it if message is truncated. 839 * UDP-Lite: always needs to checksum, no HW support. 840 */ 841 copy_only = (skb->ip_summed==CHECKSUM_UNNECESSARY); 842 843 if (is_udplite || (!copy_only && msg->msg_flags&MSG_TRUNC)) { 844 if (__udp_lib_checksum_complete(skb)) 845 goto csum_copy_err; 846 copy_only = 1; 847 } 848 849 if (copy_only) 850 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), 851 msg->msg_iov, copied ); 852 else { 853 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); 854 855 if (err == -EINVAL) 856 goto csum_copy_err; 857 } 858 859 if (err) 860 goto out_free; 861 862 sock_recv_timestamp(msg, sk, skb); 863 864 /* Copy the address. */ 865 if (sin) 866 { 867 sin->sin_family = AF_INET; 868 sin->sin_port = skb->h.uh->source; 869 sin->sin_addr.s_addr = skb->nh.iph->saddr; 870 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 871 } 872 if (inet->cmsg_flags) 873 ip_cmsg_recv(msg, skb); 874 875 err = copied; 876 if (flags & MSG_TRUNC) 877 err = skb->len - sizeof(struct udphdr); 878 879 out_free: 880 skb_free_datagram(sk, skb); 881 out: 882 return err; 883 884 csum_copy_err: 885 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite); 886 887 skb_kill_datagram(sk, skb, flags); 888 889 if (noblock) 890 return -EAGAIN; 891 goto try_again; 892 } 893 894 895 int udp_disconnect(struct sock *sk, int flags) 896 { 897 struct inet_sock *inet = inet_sk(sk); 898 /* 899 * 1003.1g - break association. 900 */ 901 902 sk->sk_state = TCP_CLOSE; 903 inet->daddr = 0; 904 inet->dport = 0; 905 sk->sk_bound_dev_if = 0; 906 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 907 inet_reset_saddr(sk); 908 909 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 910 sk->sk_prot->unhash(sk); 911 inet->sport = 0; 912 } 913 sk_dst_reset(sk); 914 return 0; 915 } 916 917 /* return: 918 * 1 if the the UDP system should process it 919 * 0 if we should drop this packet 920 * -1 if it should get processed by xfrm4_rcv_encap 921 */ 922 static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb) 923 { 924 #ifndef CONFIG_XFRM 925 return 1; 926 #else 927 struct udp_sock *up = udp_sk(sk); 928 struct udphdr *uh; 929 struct iphdr *iph; 930 int iphlen, len; 931 932 __u8 *udpdata; 933 __be32 *udpdata32; 934 __u16 encap_type = up->encap_type; 935 936 /* if we're overly short, let UDP handle it */ 937 len = skb->len - sizeof(struct udphdr); 938 if (len <= 0) 939 return 1; 940 941 /* if this is not encapsulated socket, then just return now */ 942 if (!encap_type) 943 return 1; 944 945 /* If this is a paged skb, make sure we pull up 946 * whatever data we need to look at. */ 947 if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8))) 948 return 1; 949 950 /* Now we can get the pointers */ 951 uh = skb->h.uh; 952 udpdata = (__u8 *)uh + sizeof(struct udphdr); 953 udpdata32 = (__be32 *)udpdata; 954 955 switch (encap_type) { 956 default: 957 case UDP_ENCAP_ESPINUDP: 958 /* Check if this is a keepalive packet. If so, eat it. */ 959 if (len == 1 && udpdata[0] == 0xff) { 960 return 0; 961 } else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0 ) { 962 /* ESP Packet without Non-ESP header */ 963 len = sizeof(struct udphdr); 964 } else 965 /* Must be an IKE packet.. pass it through */ 966 return 1; 967 break; 968 case UDP_ENCAP_ESPINUDP_NON_IKE: 969 /* Check if this is a keepalive packet. If so, eat it. */ 970 if (len == 1 && udpdata[0] == 0xff) { 971 return 0; 972 } else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) && 973 udpdata32[0] == 0 && udpdata32[1] == 0) { 974 975 /* ESP Packet with Non-IKE marker */ 976 len = sizeof(struct udphdr) + 2 * sizeof(u32); 977 } else 978 /* Must be an IKE packet.. pass it through */ 979 return 1; 980 break; 981 } 982 983 /* At this point we are sure that this is an ESPinUDP packet, 984 * so we need to remove 'len' bytes from the packet (the UDP 985 * header and optional ESP marker bytes) and then modify the 986 * protocol to ESP, and then call into the transform receiver. 987 */ 988 if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 989 return 0; 990 991 /* Now we can update and verify the packet length... */ 992 iph = skb->nh.iph; 993 iphlen = iph->ihl << 2; 994 iph->tot_len = htons(ntohs(iph->tot_len) - len); 995 if (skb->len < iphlen + len) { 996 /* packet is too small!?! */ 997 return 0; 998 } 999 1000 /* pull the data buffer up to the ESP header and set the 1001 * transport header to point to ESP. Keep UDP on the stack 1002 * for later. 1003 */ 1004 skb->h.raw = skb_pull(skb, len); 1005 1006 /* modify the protocol (it's ESP!) */ 1007 iph->protocol = IPPROTO_ESP; 1008 1009 /* and let the caller know to send this into the ESP processor... */ 1010 return -1; 1011 #endif 1012 } 1013 1014 /* returns: 1015 * -1: error 1016 * 0: success 1017 * >0: "udp encap" protocol resubmission 1018 * 1019 * Note that in the success and error cases, the skb is assumed to 1020 * have either been requeued or freed. 1021 */ 1022 int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) 1023 { 1024 struct udp_sock *up = udp_sk(sk); 1025 int rc; 1026 1027 /* 1028 * Charge it to the socket, dropping if the queue is full. 1029 */ 1030 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1031 goto drop; 1032 nf_reset(skb); 1033 1034 if (up->encap_type) { 1035 /* 1036 * This is an encapsulation socket, so let's see if this is 1037 * an encapsulated packet. 1038 * If it's a keepalive packet, then just eat it. 1039 * If it's an encapsulateed packet, then pass it to the 1040 * IPsec xfrm input and return the response 1041 * appropriately. Otherwise, just fall through and 1042 * pass this up the UDP socket. 1043 */ 1044 int ret; 1045 1046 ret = udp_encap_rcv(sk, skb); 1047 if (ret == 0) { 1048 /* Eat the packet .. */ 1049 kfree_skb(skb); 1050 return 0; 1051 } 1052 if (ret < 0) { 1053 /* process the ESP packet */ 1054 ret = xfrm4_rcv_encap(skb, up->encap_type); 1055 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag); 1056 return -ret; 1057 } 1058 /* FALLTHROUGH -- it's a UDP Packet */ 1059 } 1060 1061 /* 1062 * UDP-Lite specific tests, ignored on UDP sockets 1063 */ 1064 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1065 1066 /* 1067 * MIB statistics other than incrementing the error count are 1068 * disabled for the following two types of errors: these depend 1069 * on the application settings, not on the functioning of the 1070 * protocol stack as such. 1071 * 1072 * RFC 3828 here recommends (sec 3.3): "There should also be a 1073 * way ... to ... at least let the receiving application block 1074 * delivery of packets with coverage values less than a value 1075 * provided by the application." 1076 */ 1077 if (up->pcrlen == 0) { /* full coverage was set */ 1078 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage " 1079 "%d while full coverage %d requested\n", 1080 UDP_SKB_CB(skb)->cscov, skb->len); 1081 goto drop; 1082 } 1083 /* The next case involves violating the min. coverage requested 1084 * by the receiver. This is subtle: if receiver wants x and x is 1085 * greater than the buffersize/MTU then receiver will complain 1086 * that it wants x while sender emits packets of smaller size y. 1087 * Therefore the above ...()->partial_cov statement is essential. 1088 */ 1089 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1090 LIMIT_NETDEBUG(KERN_WARNING 1091 "UDPLITE: coverage %d too small, need min %d\n", 1092 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1093 goto drop; 1094 } 1095 } 1096 1097 if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) { 1098 if (__udp_lib_checksum_complete(skb)) 1099 goto drop; 1100 skb->ip_summed = CHECKSUM_UNNECESSARY; 1101 } 1102 1103 if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) { 1104 /* Note that an ENOMEM error is charged twice */ 1105 if (rc == -ENOMEM) 1106 UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag); 1107 goto drop; 1108 } 1109 1110 UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag); 1111 return 0; 1112 1113 drop: 1114 UDP_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag); 1115 kfree_skb(skb); 1116 return -1; 1117 } 1118 1119 /* 1120 * Multicasts and broadcasts go to each listener. 1121 * 1122 * Note: called only from the BH handler context, 1123 * so we don't need to lock the hashes. 1124 */ 1125 static int __udp4_lib_mcast_deliver(struct sk_buff *skb, 1126 struct udphdr *uh, 1127 __be32 saddr, __be32 daddr, 1128 struct hlist_head udptable[]) 1129 { 1130 struct sock *sk; 1131 int dif; 1132 1133 read_lock(&udp_hash_lock); 1134 sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]); 1135 dif = skb->dev->ifindex; 1136 sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif); 1137 if (sk) { 1138 struct sock *sknext = NULL; 1139 1140 do { 1141 struct sk_buff *skb1 = skb; 1142 1143 sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr, 1144 uh->source, saddr, dif); 1145 if(sknext) 1146 skb1 = skb_clone(skb, GFP_ATOMIC); 1147 1148 if(skb1) { 1149 int ret = udp_queue_rcv_skb(sk, skb1); 1150 if (ret > 0) 1151 /* we should probably re-process instead 1152 * of dropping packets here. */ 1153 kfree_skb(skb1); 1154 } 1155 sk = sknext; 1156 } while(sknext); 1157 } else 1158 kfree_skb(skb); 1159 read_unlock(&udp_hash_lock); 1160 return 0; 1161 } 1162 1163 /* Initialize UDP checksum. If exited with zero value (success), 1164 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1165 * Otherwise, csum completion requires chacksumming packet body, 1166 * including udp header and folding it to skb->csum. 1167 */ 1168 static inline void udp4_csum_init(struct sk_buff *skb, struct udphdr *uh) 1169 { 1170 if (uh->check == 0) { 1171 skb->ip_summed = CHECKSUM_UNNECESSARY; 1172 } else if (skb->ip_summed == CHECKSUM_COMPLETE) { 1173 if (!csum_tcpudp_magic(skb->nh.iph->saddr, skb->nh.iph->daddr, 1174 skb->len, IPPROTO_UDP, skb->csum )) 1175 skb->ip_summed = CHECKSUM_UNNECESSARY; 1176 } 1177 if (skb->ip_summed != CHECKSUM_UNNECESSARY) 1178 skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr, 1179 skb->nh.iph->daddr, 1180 skb->len, IPPROTO_UDP, 0); 1181 /* Probably, we should checksum udp header (it should be in cache 1182 * in any case) and data in tiny packets (< rx copybreak). 1183 */ 1184 1185 /* UDP = UDP-Lite with a non-partial checksum coverage */ 1186 UDP_SKB_CB(skb)->partial_cov = 0; 1187 } 1188 1189 /* 1190 * All we need to do is get the socket, and then do a checksum. 1191 */ 1192 1193 int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[], 1194 int is_udplite) 1195 { 1196 struct sock *sk; 1197 struct udphdr *uh = skb->h.uh; 1198 unsigned short ulen; 1199 struct rtable *rt = (struct rtable*)skb->dst; 1200 __be32 saddr = skb->nh.iph->saddr; 1201 __be32 daddr = skb->nh.iph->daddr; 1202 1203 /* 1204 * Validate the packet. 1205 */ 1206 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1207 goto drop; /* No space for header. */ 1208 1209 ulen = ntohs(uh->len); 1210 if (ulen > skb->len) 1211 goto short_packet; 1212 1213 if(! is_udplite ) { /* UDP validates ulen. */ 1214 1215 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1216 goto short_packet; 1217 1218 udp4_csum_init(skb, uh); 1219 1220 } else { /* UDP-Lite validates cscov. */ 1221 if (udplite4_csum_init(skb, uh)) 1222 goto csum_error; 1223 } 1224 1225 if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1226 return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable); 1227 1228 sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest, 1229 skb->dev->ifindex, udptable ); 1230 1231 if (sk != NULL) { 1232 int ret = udp_queue_rcv_skb(sk, skb); 1233 sock_put(sk); 1234 1235 /* a return value > 0 means to resubmit the input, but 1236 * it wants the return to be -protocol, or 0 1237 */ 1238 if (ret > 0) 1239 return -ret; 1240 return 0; 1241 } 1242 1243 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1244 goto drop; 1245 nf_reset(skb); 1246 1247 /* No socket. Drop packet silently, if checksum is wrong */ 1248 if (udp_lib_checksum_complete(skb)) 1249 goto csum_error; 1250 1251 UDP_INC_STATS_BH(UDP_MIB_NOPORTS, is_udplite); 1252 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1253 1254 /* 1255 * Hmm. We got an UDP packet to a port to which we 1256 * don't wanna listen. Ignore it. 1257 */ 1258 kfree_skb(skb); 1259 return(0); 1260 1261 short_packet: 1262 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n", 1263 is_udplite? "-Lite" : "", 1264 NIPQUAD(saddr), 1265 ntohs(uh->source), 1266 ulen, 1267 skb->len, 1268 NIPQUAD(daddr), 1269 ntohs(uh->dest)); 1270 goto drop; 1271 1272 csum_error: 1273 /* 1274 * RFC1122: OK. Discards the bad packet silently (as far as 1275 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1276 */ 1277 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n", 1278 is_udplite? "-Lite" : "", 1279 NIPQUAD(saddr), 1280 ntohs(uh->source), 1281 NIPQUAD(daddr), 1282 ntohs(uh->dest), 1283 ulen); 1284 drop: 1285 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite); 1286 kfree_skb(skb); 1287 return(0); 1288 } 1289 1290 __inline__ int udp_rcv(struct sk_buff *skb) 1291 { 1292 return __udp4_lib_rcv(skb, udp_hash, 0); 1293 } 1294 1295 int udp_destroy_sock(struct sock *sk) 1296 { 1297 lock_sock(sk); 1298 udp_flush_pending_frames(sk); 1299 release_sock(sk); 1300 return 0; 1301 } 1302 1303 /* 1304 * Socket option code for UDP 1305 */ 1306 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 1307 char __user *optval, int optlen, 1308 int (*push_pending_frames)(struct sock *)) 1309 { 1310 struct udp_sock *up = udp_sk(sk); 1311 int val; 1312 int err = 0; 1313 1314 if(optlen<sizeof(int)) 1315 return -EINVAL; 1316 1317 if (get_user(val, (int __user *)optval)) 1318 return -EFAULT; 1319 1320 switch(optname) { 1321 case UDP_CORK: 1322 if (val != 0) { 1323 up->corkflag = 1; 1324 } else { 1325 up->corkflag = 0; 1326 lock_sock(sk); 1327 (*push_pending_frames)(sk); 1328 release_sock(sk); 1329 } 1330 break; 1331 1332 case UDP_ENCAP: 1333 switch (val) { 1334 case 0: 1335 case UDP_ENCAP_ESPINUDP: 1336 case UDP_ENCAP_ESPINUDP_NON_IKE: 1337 up->encap_type = val; 1338 break; 1339 default: 1340 err = -ENOPROTOOPT; 1341 break; 1342 } 1343 break; 1344 1345 /* 1346 * UDP-Lite's partial checksum coverage (RFC 3828). 1347 */ 1348 /* The sender sets actual checksum coverage length via this option. 1349 * The case coverage > packet length is handled by send module. */ 1350 case UDPLITE_SEND_CSCOV: 1351 if (!up->pcflag) /* Disable the option on UDP sockets */ 1352 return -ENOPROTOOPT; 1353 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 1354 val = 8; 1355 up->pcslen = val; 1356 up->pcflag |= UDPLITE_SEND_CC; 1357 break; 1358 1359 /* The receiver specifies a minimum checksum coverage value. To make 1360 * sense, this should be set to at least 8 (as done below). If zero is 1361 * used, this again means full checksum coverage. */ 1362 case UDPLITE_RECV_CSCOV: 1363 if (!up->pcflag) /* Disable the option on UDP sockets */ 1364 return -ENOPROTOOPT; 1365 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 1366 val = 8; 1367 up->pcrlen = val; 1368 up->pcflag |= UDPLITE_RECV_CC; 1369 break; 1370 1371 default: 1372 err = -ENOPROTOOPT; 1373 break; 1374 }; 1375 1376 return err; 1377 } 1378 1379 int udp_setsockopt(struct sock *sk, int level, int optname, 1380 char __user *optval, int optlen) 1381 { 1382 if (level == SOL_UDP || level == SOL_UDPLITE) 1383 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1384 udp_push_pending_frames); 1385 return ip_setsockopt(sk, level, optname, optval, optlen); 1386 } 1387 1388 #ifdef CONFIG_COMPAT 1389 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 1390 char __user *optval, int optlen) 1391 { 1392 if (level == SOL_UDP || level == SOL_UDPLITE) 1393 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1394 udp_push_pending_frames); 1395 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 1396 } 1397 #endif 1398 1399 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 1400 char __user *optval, int __user *optlen) 1401 { 1402 struct udp_sock *up = udp_sk(sk); 1403 int val, len; 1404 1405 if(get_user(len,optlen)) 1406 return -EFAULT; 1407 1408 len = min_t(unsigned int, len, sizeof(int)); 1409 1410 if(len < 0) 1411 return -EINVAL; 1412 1413 switch(optname) { 1414 case UDP_CORK: 1415 val = up->corkflag; 1416 break; 1417 1418 case UDP_ENCAP: 1419 val = up->encap_type; 1420 break; 1421 1422 /* The following two cannot be changed on UDP sockets, the return is 1423 * always 0 (which corresponds to the full checksum coverage of UDP). */ 1424 case UDPLITE_SEND_CSCOV: 1425 val = up->pcslen; 1426 break; 1427 1428 case UDPLITE_RECV_CSCOV: 1429 val = up->pcrlen; 1430 break; 1431 1432 default: 1433 return -ENOPROTOOPT; 1434 }; 1435 1436 if(put_user(len, optlen)) 1437 return -EFAULT; 1438 if(copy_to_user(optval, &val,len)) 1439 return -EFAULT; 1440 return 0; 1441 } 1442 1443 int udp_getsockopt(struct sock *sk, int level, int optname, 1444 char __user *optval, int __user *optlen) 1445 { 1446 if (level == SOL_UDP || level == SOL_UDPLITE) 1447 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1448 return ip_getsockopt(sk, level, optname, optval, optlen); 1449 } 1450 1451 #ifdef CONFIG_COMPAT 1452 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 1453 char __user *optval, int __user *optlen) 1454 { 1455 if (level == SOL_UDP || level == SOL_UDPLITE) 1456 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1457 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 1458 } 1459 #endif 1460 /** 1461 * udp_poll - wait for a UDP event. 1462 * @file - file struct 1463 * @sock - socket 1464 * @wait - poll table 1465 * 1466 * This is same as datagram poll, except for the special case of 1467 * blocking sockets. If application is using a blocking fd 1468 * and a packet with checksum error is in the queue; 1469 * then it could get return from select indicating data available 1470 * but then block when reading it. Add special case code 1471 * to work around these arguably broken applications. 1472 */ 1473 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 1474 { 1475 unsigned int mask = datagram_poll(file, sock, wait); 1476 struct sock *sk = sock->sk; 1477 int is_lite = IS_UDPLITE(sk); 1478 1479 /* Check for false positives due to checksum errors */ 1480 if ( (mask & POLLRDNORM) && 1481 !(file->f_flags & O_NONBLOCK) && 1482 !(sk->sk_shutdown & RCV_SHUTDOWN)){ 1483 struct sk_buff_head *rcvq = &sk->sk_receive_queue; 1484 struct sk_buff *skb; 1485 1486 spin_lock_bh(&rcvq->lock); 1487 while ((skb = skb_peek(rcvq)) != NULL) { 1488 if (udp_lib_checksum_complete(skb)) { 1489 UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite); 1490 __skb_unlink(skb, rcvq); 1491 kfree_skb(skb); 1492 } else { 1493 skb->ip_summed = CHECKSUM_UNNECESSARY; 1494 break; 1495 } 1496 } 1497 spin_unlock_bh(&rcvq->lock); 1498 1499 /* nothing to see, move along */ 1500 if (skb == NULL) 1501 mask &= ~(POLLIN | POLLRDNORM); 1502 } 1503 1504 return mask; 1505 1506 } 1507 1508 struct proto udp_prot = { 1509 .name = "UDP", 1510 .owner = THIS_MODULE, 1511 .close = udp_lib_close, 1512 .connect = ip4_datagram_connect, 1513 .disconnect = udp_disconnect, 1514 .ioctl = udp_ioctl, 1515 .destroy = udp_destroy_sock, 1516 .setsockopt = udp_setsockopt, 1517 .getsockopt = udp_getsockopt, 1518 .sendmsg = udp_sendmsg, 1519 .recvmsg = udp_recvmsg, 1520 .sendpage = udp_sendpage, 1521 .backlog_rcv = udp_queue_rcv_skb, 1522 .hash = udp_lib_hash, 1523 .unhash = udp_lib_unhash, 1524 .get_port = udp_v4_get_port, 1525 .obj_size = sizeof(struct udp_sock), 1526 #ifdef CONFIG_COMPAT 1527 .compat_setsockopt = compat_udp_setsockopt, 1528 .compat_getsockopt = compat_udp_getsockopt, 1529 #endif 1530 }; 1531 1532 /* ------------------------------------------------------------------------ */ 1533 #ifdef CONFIG_PROC_FS 1534 1535 static struct sock *udp_get_first(struct seq_file *seq) 1536 { 1537 struct sock *sk; 1538 struct udp_iter_state *state = seq->private; 1539 1540 for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) { 1541 struct hlist_node *node; 1542 sk_for_each(sk, node, state->hashtable + state->bucket) { 1543 if (sk->sk_family == state->family) 1544 goto found; 1545 } 1546 } 1547 sk = NULL; 1548 found: 1549 return sk; 1550 } 1551 1552 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 1553 { 1554 struct udp_iter_state *state = seq->private; 1555 1556 do { 1557 sk = sk_next(sk); 1558 try_again: 1559 ; 1560 } while (sk && sk->sk_family != state->family); 1561 1562 if (!sk && ++state->bucket < UDP_HTABLE_SIZE) { 1563 sk = sk_head(state->hashtable + state->bucket); 1564 goto try_again; 1565 } 1566 return sk; 1567 } 1568 1569 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 1570 { 1571 struct sock *sk = udp_get_first(seq); 1572 1573 if (sk) 1574 while(pos && (sk = udp_get_next(seq, sk)) != NULL) 1575 --pos; 1576 return pos ? NULL : sk; 1577 } 1578 1579 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 1580 { 1581 read_lock(&udp_hash_lock); 1582 return *pos ? udp_get_idx(seq, *pos-1) : (void *)1; 1583 } 1584 1585 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1586 { 1587 struct sock *sk; 1588 1589 if (v == (void *)1) 1590 sk = udp_get_idx(seq, 0); 1591 else 1592 sk = udp_get_next(seq, v); 1593 1594 ++*pos; 1595 return sk; 1596 } 1597 1598 static void udp_seq_stop(struct seq_file *seq, void *v) 1599 { 1600 read_unlock(&udp_hash_lock); 1601 } 1602 1603 static int udp_seq_open(struct inode *inode, struct file *file) 1604 { 1605 struct udp_seq_afinfo *afinfo = PDE(inode)->data; 1606 struct seq_file *seq; 1607 int rc = -ENOMEM; 1608 struct udp_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL); 1609 1610 if (!s) 1611 goto out; 1612 s->family = afinfo->family; 1613 s->hashtable = afinfo->hashtable; 1614 s->seq_ops.start = udp_seq_start; 1615 s->seq_ops.next = udp_seq_next; 1616 s->seq_ops.show = afinfo->seq_show; 1617 s->seq_ops.stop = udp_seq_stop; 1618 1619 rc = seq_open(file, &s->seq_ops); 1620 if (rc) 1621 goto out_kfree; 1622 1623 seq = file->private_data; 1624 seq->private = s; 1625 out: 1626 return rc; 1627 out_kfree: 1628 kfree(s); 1629 goto out; 1630 } 1631 1632 /* ------------------------------------------------------------------------ */ 1633 int udp_proc_register(struct udp_seq_afinfo *afinfo) 1634 { 1635 struct proc_dir_entry *p; 1636 int rc = 0; 1637 1638 if (!afinfo) 1639 return -EINVAL; 1640 afinfo->seq_fops->owner = afinfo->owner; 1641 afinfo->seq_fops->open = udp_seq_open; 1642 afinfo->seq_fops->read = seq_read; 1643 afinfo->seq_fops->llseek = seq_lseek; 1644 afinfo->seq_fops->release = seq_release_private; 1645 1646 p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops); 1647 if (p) 1648 p->data = afinfo; 1649 else 1650 rc = -ENOMEM; 1651 return rc; 1652 } 1653 1654 void udp_proc_unregister(struct udp_seq_afinfo *afinfo) 1655 { 1656 if (!afinfo) 1657 return; 1658 proc_net_remove(afinfo->name); 1659 memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops)); 1660 } 1661 1662 /* ------------------------------------------------------------------------ */ 1663 static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket) 1664 { 1665 struct inet_sock *inet = inet_sk(sp); 1666 __be32 dest = inet->daddr; 1667 __be32 src = inet->rcv_saddr; 1668 __u16 destp = ntohs(inet->dport); 1669 __u16 srcp = ntohs(inet->sport); 1670 1671 sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" 1672 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p", 1673 bucket, src, srcp, dest, destp, sp->sk_state, 1674 atomic_read(&sp->sk_wmem_alloc), 1675 atomic_read(&sp->sk_rmem_alloc), 1676 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), 1677 atomic_read(&sp->sk_refcnt), sp); 1678 } 1679 1680 int udp4_seq_show(struct seq_file *seq, void *v) 1681 { 1682 if (v == SEQ_START_TOKEN) 1683 seq_printf(seq, "%-127s\n", 1684 " sl local_address rem_address st tx_queue " 1685 "rx_queue tr tm->when retrnsmt uid timeout " 1686 "inode"); 1687 else { 1688 char tmpbuf[129]; 1689 struct udp_iter_state *state = seq->private; 1690 1691 udp4_format_sock(v, tmpbuf, state->bucket); 1692 seq_printf(seq, "%-127s\n", tmpbuf); 1693 } 1694 return 0; 1695 } 1696 1697 /* ------------------------------------------------------------------------ */ 1698 static struct file_operations udp4_seq_fops; 1699 static struct udp_seq_afinfo udp4_seq_afinfo = { 1700 .owner = THIS_MODULE, 1701 .name = "udp", 1702 .family = AF_INET, 1703 .hashtable = udp_hash, 1704 .seq_show = udp4_seq_show, 1705 .seq_fops = &udp4_seq_fops, 1706 }; 1707 1708 int __init udp4_proc_init(void) 1709 { 1710 return udp_proc_register(&udp4_seq_afinfo); 1711 } 1712 1713 void udp4_proc_exit(void) 1714 { 1715 udp_proc_unregister(&udp4_seq_afinfo); 1716 } 1717 #endif /* CONFIG_PROC_FS */ 1718 1719 EXPORT_SYMBOL(udp_disconnect); 1720 EXPORT_SYMBOL(udp_hash); 1721 EXPORT_SYMBOL(udp_hash_lock); 1722 EXPORT_SYMBOL(udp_ioctl); 1723 EXPORT_SYMBOL(udp_get_port); 1724 EXPORT_SYMBOL(udp_prot); 1725 EXPORT_SYMBOL(udp_sendmsg); 1726 EXPORT_SYMBOL(udp_lib_getsockopt); 1727 EXPORT_SYMBOL(udp_lib_setsockopt); 1728 EXPORT_SYMBOL(udp_poll); 1729 1730 #ifdef CONFIG_PROC_FS 1731 EXPORT_SYMBOL(udp_proc_register); 1732 EXPORT_SYMBOL(udp_proc_unregister); 1733 #endif 1734