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 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 11 * Alan Cox, <alan@lxorguk.ukuu.org.uk> 12 * Hirokazu Takahashi, <taka@valinux.co.jp> 13 * 14 * Fixes: 15 * Alan Cox : verify_area() calls 16 * Alan Cox : stopped close while in use off icmp 17 * messages. Not a fix but a botch that 18 * for udp at least is 'valid'. 19 * Alan Cox : Fixed icmp handling properly 20 * Alan Cox : Correct error for oversized datagrams 21 * Alan Cox : Tidied select() semantics. 22 * Alan Cox : udp_err() fixed properly, also now 23 * select and read wake correctly on errors 24 * Alan Cox : udp_send verify_area moved to avoid mem leak 25 * Alan Cox : UDP can count its memory 26 * Alan Cox : send to an unknown connection causes 27 * an ECONNREFUSED off the icmp, but 28 * does NOT close. 29 * Alan Cox : Switched to new sk_buff handlers. No more backlog! 30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK 31 * bug no longer crashes it. 32 * Fred Van Kempen : Net2e support for sk->broadcast. 33 * Alan Cox : Uses skb_free_datagram 34 * Alan Cox : Added get/set sockopt support. 35 * Alan Cox : Broadcasting without option set returns EACCES. 36 * Alan Cox : No wakeup calls. Instead we now use the callbacks. 37 * Alan Cox : Use ip_tos and ip_ttl 38 * Alan Cox : SNMP Mibs 39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. 40 * Matt Dillon : UDP length checks. 41 * Alan Cox : Smarter af_inet used properly. 42 * Alan Cox : Use new kernel side addressing. 43 * Alan Cox : Incorrect return on truncated datagram receive. 44 * Arnt Gulbrandsen : New udp_send and stuff 45 * Alan Cox : Cache last socket 46 * Alan Cox : Route cache 47 * Jon Peatfield : Minor efficiency fix to sendto(). 48 * Mike Shaver : RFC1122 checks. 49 * Alan Cox : Nonblocking error fix. 50 * Willy Konynenberg : Transparent proxying support. 51 * Mike McLagan : Routing by source 52 * David S. Miller : New socket lookup architecture. 53 * Last socket cache retained as it 54 * does have a high hit rate. 55 * Olaf Kirch : Don't linearise iovec on sendmsg. 56 * Andi Kleen : Some cleanups, cache destination entry 57 * for connect. 58 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 59 * Melvin Smith : Check msg_name not msg_namelen in sendto(), 60 * return ENOTCONN for unconnected sockets (POSIX) 61 * Janos Farkas : don't deliver multi/broadcasts to a different 62 * bound-to-device socket 63 * Hirokazu Takahashi : HW checksumming for outgoing UDP 64 * datagrams. 65 * Hirokazu Takahashi : sendfile() on UDP works now. 66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file 67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind 69 * a single port at the same time. 70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support 71 * James Chapman : Add L2TP encapsulation type. 72 * 73 * 74 * This program is free software; you can redistribute it and/or 75 * modify it under the terms of the GNU General Public License 76 * as published by the Free Software Foundation; either version 77 * 2 of the License, or (at your option) any later version. 78 */ 79 80 #include <asm/system.h> 81 #include <asm/uaccess.h> 82 #include <asm/ioctls.h> 83 #include <linux/bootmem.h> 84 #include <linux/highmem.h> 85 #include <linux/swap.h> 86 #include <linux/types.h> 87 #include <linux/fcntl.h> 88 #include <linux/module.h> 89 #include <linux/socket.h> 90 #include <linux/sockios.h> 91 #include <linux/igmp.h> 92 #include <linux/in.h> 93 #include <linux/errno.h> 94 #include <linux/timer.h> 95 #include <linux/mm.h> 96 #include <linux/inet.h> 97 #include <linux/netdevice.h> 98 #include <net/tcp_states.h> 99 #include <linux/skbuff.h> 100 #include <linux/proc_fs.h> 101 #include <linux/seq_file.h> 102 #include <net/net_namespace.h> 103 #include <net/icmp.h> 104 #include <net/route.h> 105 #include <net/checksum.h> 106 #include <net/xfrm.h> 107 #include "udp_impl.h" 108 109 struct udp_table udp_table; 110 EXPORT_SYMBOL(udp_table); 111 112 int sysctl_udp_mem[3] __read_mostly; 113 int sysctl_udp_rmem_min __read_mostly; 114 int sysctl_udp_wmem_min __read_mostly; 115 116 EXPORT_SYMBOL(sysctl_udp_mem); 117 EXPORT_SYMBOL(sysctl_udp_rmem_min); 118 EXPORT_SYMBOL(sysctl_udp_wmem_min); 119 120 atomic_t udp_memory_allocated; 121 EXPORT_SYMBOL(udp_memory_allocated); 122 123 #define PORTS_PER_CHAIN (65536 / UDP_HTABLE_SIZE) 124 125 static int udp_lib_lport_inuse(struct net *net, __u16 num, 126 const struct udp_hslot *hslot, 127 unsigned long *bitmap, 128 struct sock *sk, 129 int (*saddr_comp)(const struct sock *sk1, 130 const struct sock *sk2)) 131 { 132 struct sock *sk2; 133 struct hlist_nulls_node *node; 134 135 sk_nulls_for_each(sk2, node, &hslot->head) 136 if (net_eq(sock_net(sk2), net) && 137 sk2 != sk && 138 (bitmap || sk2->sk_hash == num) && 139 (!sk2->sk_reuse || !sk->sk_reuse) && 140 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if 141 || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 142 (*saddr_comp)(sk, sk2)) { 143 if (bitmap) 144 __set_bit(sk2->sk_hash / UDP_HTABLE_SIZE, 145 bitmap); 146 else 147 return 1; 148 } 149 return 0; 150 } 151 152 /** 153 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 154 * 155 * @sk: socket struct in question 156 * @snum: port number to look up 157 * @saddr_comp: AF-dependent comparison of bound local IP addresses 158 */ 159 int udp_lib_get_port(struct sock *sk, unsigned short snum, 160 int (*saddr_comp)(const struct sock *sk1, 161 const struct sock *sk2 ) ) 162 { 163 struct udp_hslot *hslot; 164 struct udp_table *udptable = sk->sk_prot->h.udp_table; 165 int error = 1; 166 struct net *net = sock_net(sk); 167 168 if (!snum) { 169 int low, high, remaining; 170 unsigned rand; 171 unsigned short first, last; 172 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 173 174 inet_get_local_port_range(&low, &high); 175 remaining = (high - low) + 1; 176 177 rand = net_random(); 178 first = (((u64)rand * remaining) >> 32) + low; 179 /* 180 * force rand to be an odd multiple of UDP_HTABLE_SIZE 181 */ 182 rand = (rand | 1) * UDP_HTABLE_SIZE; 183 for (last = first + UDP_HTABLE_SIZE; first != last; first++) { 184 hslot = &udptable->hash[udp_hashfn(net, first)]; 185 bitmap_zero(bitmap, PORTS_PER_CHAIN); 186 spin_lock_bh(&hslot->lock); 187 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 188 saddr_comp); 189 190 snum = first; 191 /* 192 * Iterate on all possible values of snum for this hash. 193 * Using steps of an odd multiple of UDP_HTABLE_SIZE 194 * give us randomization and full range coverage. 195 */ 196 do { 197 if (low <= snum && snum <= high && 198 !test_bit(snum / UDP_HTABLE_SIZE, bitmap)) 199 goto found; 200 snum += rand; 201 } while (snum != first); 202 spin_unlock_bh(&hslot->lock); 203 } 204 goto fail; 205 } else { 206 hslot = &udptable->hash[udp_hashfn(net, snum)]; 207 spin_lock_bh(&hslot->lock); 208 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, saddr_comp)) 209 goto fail_unlock; 210 } 211 found: 212 inet_sk(sk)->num = snum; 213 sk->sk_hash = snum; 214 if (sk_unhashed(sk)) { 215 sk_nulls_add_node_rcu(sk, &hslot->head); 216 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 217 } 218 error = 0; 219 fail_unlock: 220 spin_unlock_bh(&hslot->lock); 221 fail: 222 return error; 223 } 224 225 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 226 { 227 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 228 229 return ( !ipv6_only_sock(sk2) && 230 (!inet1->rcv_saddr || !inet2->rcv_saddr || 231 inet1->rcv_saddr == inet2->rcv_saddr )); 232 } 233 234 int udp_v4_get_port(struct sock *sk, unsigned short snum) 235 { 236 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal); 237 } 238 239 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr, 240 unsigned short hnum, 241 __be16 sport, __be32 daddr, __be16 dport, int dif) 242 { 243 int score = -1; 244 245 if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum && 246 !ipv6_only_sock(sk)) { 247 struct inet_sock *inet = inet_sk(sk); 248 249 score = (sk->sk_family == PF_INET ? 1 : 0); 250 if (inet->rcv_saddr) { 251 if (inet->rcv_saddr != daddr) 252 return -1; 253 score += 2; 254 } 255 if (inet->daddr) { 256 if (inet->daddr != saddr) 257 return -1; 258 score += 2; 259 } 260 if (inet->dport) { 261 if (inet->dport != sport) 262 return -1; 263 score += 2; 264 } 265 if (sk->sk_bound_dev_if) { 266 if (sk->sk_bound_dev_if != dif) 267 return -1; 268 score += 2; 269 } 270 } 271 return score; 272 } 273 274 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 275 * harder than this. -DaveM 276 */ 277 static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 278 __be16 sport, __be32 daddr, __be16 dport, 279 int dif, struct udp_table *udptable) 280 { 281 struct sock *sk, *result; 282 struct hlist_nulls_node *node; 283 unsigned short hnum = ntohs(dport); 284 unsigned int hash = udp_hashfn(net, hnum); 285 struct udp_hslot *hslot = &udptable->hash[hash]; 286 int score, badness; 287 288 rcu_read_lock(); 289 begin: 290 result = NULL; 291 badness = -1; 292 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 293 score = compute_score(sk, net, saddr, hnum, sport, 294 daddr, dport, dif); 295 if (score > badness) { 296 result = sk; 297 badness = score; 298 } 299 } 300 /* 301 * if the nulls value we got at the end of this lookup is 302 * not the expected one, we must restart lookup. 303 * We probably met an item that was moved to another chain. 304 */ 305 if (get_nulls_value(node) != hash) 306 goto begin; 307 308 if (result) { 309 if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt))) 310 result = NULL; 311 else if (unlikely(compute_score(result, net, saddr, hnum, sport, 312 daddr, dport, dif) < badness)) { 313 sock_put(result); 314 goto begin; 315 } 316 } 317 rcu_read_unlock(); 318 return result; 319 } 320 321 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 322 __be16 sport, __be16 dport, 323 struct udp_table *udptable) 324 { 325 struct sock *sk; 326 const struct iphdr *iph = ip_hdr(skb); 327 328 if (unlikely(sk = skb_steal_sock(skb))) 329 return sk; 330 else 331 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, 332 iph->daddr, dport, inet_iif(skb), 333 udptable); 334 } 335 336 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 337 __be32 daddr, __be16 dport, int dif) 338 { 339 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); 340 } 341 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 342 343 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk, 344 __be16 loc_port, __be32 loc_addr, 345 __be16 rmt_port, __be32 rmt_addr, 346 int dif) 347 { 348 struct hlist_nulls_node *node; 349 struct sock *s = sk; 350 unsigned short hnum = ntohs(loc_port); 351 352 sk_nulls_for_each_from(s, node) { 353 struct inet_sock *inet = inet_sk(s); 354 355 if (!net_eq(sock_net(s), net) || 356 s->sk_hash != hnum || 357 (inet->daddr && inet->daddr != rmt_addr) || 358 (inet->dport != rmt_port && inet->dport) || 359 (inet->rcv_saddr && inet->rcv_saddr != loc_addr) || 360 ipv6_only_sock(s) || 361 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) 362 continue; 363 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) 364 continue; 365 goto found; 366 } 367 s = NULL; 368 found: 369 return s; 370 } 371 372 /* 373 * This routine is called by the ICMP module when it gets some 374 * sort of error condition. If err < 0 then the socket should 375 * be closed and the error returned to the user. If err > 0 376 * it's just the icmp type << 8 | icmp code. 377 * Header points to the ip header of the error packet. We move 378 * on past this. Then (as it used to claim before adjustment) 379 * header points to the first 8 bytes of the udp header. We need 380 * to find the appropriate port. 381 */ 382 383 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 384 { 385 struct inet_sock *inet; 386 struct iphdr *iph = (struct iphdr*)skb->data; 387 struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2)); 388 const int type = icmp_hdr(skb)->type; 389 const int code = icmp_hdr(skb)->code; 390 struct sock *sk; 391 int harderr; 392 int err; 393 struct net *net = dev_net(skb->dev); 394 395 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 396 iph->saddr, uh->source, skb->dev->ifindex, udptable); 397 if (sk == NULL) { 398 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 399 return; /* No socket for error */ 400 } 401 402 err = 0; 403 harderr = 0; 404 inet = inet_sk(sk); 405 406 switch (type) { 407 default: 408 case ICMP_TIME_EXCEEDED: 409 err = EHOSTUNREACH; 410 break; 411 case ICMP_SOURCE_QUENCH: 412 goto out; 413 case ICMP_PARAMETERPROB: 414 err = EPROTO; 415 harderr = 1; 416 break; 417 case ICMP_DEST_UNREACH: 418 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 419 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 420 err = EMSGSIZE; 421 harderr = 1; 422 break; 423 } 424 goto out; 425 } 426 err = EHOSTUNREACH; 427 if (code <= NR_ICMP_UNREACH) { 428 harderr = icmp_err_convert[code].fatal; 429 err = icmp_err_convert[code].errno; 430 } 431 break; 432 } 433 434 /* 435 * RFC1122: OK. Passes ICMP errors back to application, as per 436 * 4.1.3.3. 437 */ 438 if (!inet->recverr) { 439 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 440 goto out; 441 } else { 442 ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1)); 443 } 444 sk->sk_err = err; 445 sk->sk_error_report(sk); 446 out: 447 sock_put(sk); 448 } 449 450 void udp_err(struct sk_buff *skb, u32 info) 451 { 452 __udp4_lib_err(skb, info, &udp_table); 453 } 454 455 /* 456 * Throw away all pending data and cancel the corking. Socket is locked. 457 */ 458 void udp_flush_pending_frames(struct sock *sk) 459 { 460 struct udp_sock *up = udp_sk(sk); 461 462 if (up->pending) { 463 up->len = 0; 464 up->pending = 0; 465 ip_flush_pending_frames(sk); 466 } 467 } 468 EXPORT_SYMBOL(udp_flush_pending_frames); 469 470 /** 471 * udp4_hwcsum_outgoing - handle outgoing HW checksumming 472 * @sk: socket we are sending on 473 * @skb: sk_buff containing the filled-in UDP header 474 * (checksum field must be zeroed out) 475 */ 476 static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, 477 __be32 src, __be32 dst, int len ) 478 { 479 unsigned int offset; 480 struct udphdr *uh = udp_hdr(skb); 481 __wsum csum = 0; 482 483 if (skb_queue_len(&sk->sk_write_queue) == 1) { 484 /* 485 * Only one fragment on the socket. 486 */ 487 skb->csum_start = skb_transport_header(skb) - skb->head; 488 skb->csum_offset = offsetof(struct udphdr, check); 489 uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0); 490 } else { 491 /* 492 * HW-checksum won't work as there are two or more 493 * fragments on the socket so that all csums of sk_buffs 494 * should be together 495 */ 496 offset = skb_transport_offset(skb); 497 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); 498 499 skb->ip_summed = CHECKSUM_NONE; 500 501 skb_queue_walk(&sk->sk_write_queue, skb) { 502 csum = csum_add(csum, skb->csum); 503 } 504 505 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 506 if (uh->check == 0) 507 uh->check = CSUM_MANGLED_0; 508 } 509 } 510 511 /* 512 * Push out all pending data as one UDP datagram. Socket is locked. 513 */ 514 static int udp_push_pending_frames(struct sock *sk) 515 { 516 struct udp_sock *up = udp_sk(sk); 517 struct inet_sock *inet = inet_sk(sk); 518 struct flowi *fl = &inet->cork.fl; 519 struct sk_buff *skb; 520 struct udphdr *uh; 521 int err = 0; 522 int is_udplite = IS_UDPLITE(sk); 523 __wsum csum = 0; 524 525 /* Grab the skbuff where UDP header space exists. */ 526 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) 527 goto out; 528 529 /* 530 * Create a UDP header 531 */ 532 uh = udp_hdr(skb); 533 uh->source = fl->fl_ip_sport; 534 uh->dest = fl->fl_ip_dport; 535 uh->len = htons(up->len); 536 uh->check = 0; 537 538 if (is_udplite) /* UDP-Lite */ 539 csum = udplite_csum_outgoing(sk, skb); 540 541 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ 542 543 skb->ip_summed = CHECKSUM_NONE; 544 goto send; 545 546 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 547 548 udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len); 549 goto send; 550 551 } else /* `normal' UDP */ 552 csum = udp_csum_outgoing(sk, skb); 553 554 /* add protocol-dependent pseudo-header */ 555 uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len, 556 sk->sk_protocol, csum ); 557 if (uh->check == 0) 558 uh->check = CSUM_MANGLED_0; 559 560 send: 561 err = ip_push_pending_frames(sk); 562 out: 563 up->len = 0; 564 up->pending = 0; 565 if (!err) 566 UDP_INC_STATS_USER(sock_net(sk), 567 UDP_MIB_OUTDATAGRAMS, is_udplite); 568 return err; 569 } 570 571 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 572 size_t len) 573 { 574 struct inet_sock *inet = inet_sk(sk); 575 struct udp_sock *up = udp_sk(sk); 576 int ulen = len; 577 struct ipcm_cookie ipc; 578 struct rtable *rt = NULL; 579 int free = 0; 580 int connected = 0; 581 __be32 daddr, faddr, saddr; 582 __be16 dport; 583 u8 tos; 584 int err, is_udplite = IS_UDPLITE(sk); 585 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 586 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 587 588 if (len > 0xFFFF) 589 return -EMSGSIZE; 590 591 /* 592 * Check the flags. 593 */ 594 595 if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */ 596 return -EOPNOTSUPP; 597 598 ipc.opt = NULL; 599 ipc.shtx.flags = 0; 600 601 if (up->pending) { 602 /* 603 * There are pending frames. 604 * The socket lock must be held while it's corked. 605 */ 606 lock_sock(sk); 607 if (likely(up->pending)) { 608 if (unlikely(up->pending != AF_INET)) { 609 release_sock(sk); 610 return -EINVAL; 611 } 612 goto do_append_data; 613 } 614 release_sock(sk); 615 } 616 ulen += sizeof(struct udphdr); 617 618 /* 619 * Get and verify the address. 620 */ 621 if (msg->msg_name) { 622 struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name; 623 if (msg->msg_namelen < sizeof(*usin)) 624 return -EINVAL; 625 if (usin->sin_family != AF_INET) { 626 if (usin->sin_family != AF_UNSPEC) 627 return -EAFNOSUPPORT; 628 } 629 630 daddr = usin->sin_addr.s_addr; 631 dport = usin->sin_port; 632 if (dport == 0) 633 return -EINVAL; 634 } else { 635 if (sk->sk_state != TCP_ESTABLISHED) 636 return -EDESTADDRREQ; 637 daddr = inet->daddr; 638 dport = inet->dport; 639 /* Open fast path for connected socket. 640 Route will not be used, if at least one option is set. 641 */ 642 connected = 1; 643 } 644 ipc.addr = inet->saddr; 645 646 ipc.oif = sk->sk_bound_dev_if; 647 err = sock_tx_timestamp(msg, sk, &ipc.shtx); 648 if (err) 649 return err; 650 if (msg->msg_controllen) { 651 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 652 if (err) 653 return err; 654 if (ipc.opt) 655 free = 1; 656 connected = 0; 657 } 658 if (!ipc.opt) 659 ipc.opt = inet->opt; 660 661 saddr = ipc.addr; 662 ipc.addr = faddr = daddr; 663 664 if (ipc.opt && ipc.opt->srr) { 665 if (!daddr) 666 return -EINVAL; 667 faddr = ipc.opt->faddr; 668 connected = 0; 669 } 670 tos = RT_TOS(inet->tos); 671 if (sock_flag(sk, SOCK_LOCALROUTE) || 672 (msg->msg_flags & MSG_DONTROUTE) || 673 (ipc.opt && ipc.opt->is_strictroute)) { 674 tos |= RTO_ONLINK; 675 connected = 0; 676 } 677 678 if (ipv4_is_multicast(daddr)) { 679 if (!ipc.oif) 680 ipc.oif = inet->mc_index; 681 if (!saddr) 682 saddr = inet->mc_addr; 683 connected = 0; 684 } 685 686 if (connected) 687 rt = (struct rtable*)sk_dst_check(sk, 0); 688 689 if (rt == NULL) { 690 struct flowi fl = { .oif = ipc.oif, 691 .nl_u = { .ip4_u = 692 { .daddr = faddr, 693 .saddr = saddr, 694 .tos = tos } }, 695 .proto = sk->sk_protocol, 696 .flags = inet_sk_flowi_flags(sk), 697 .uli_u = { .ports = 698 { .sport = inet->sport, 699 .dport = dport } } }; 700 struct net *net = sock_net(sk); 701 702 security_sk_classify_flow(sk, &fl); 703 err = ip_route_output_flow(net, &rt, &fl, sk, 1); 704 if (err) { 705 if (err == -ENETUNREACH) 706 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 707 goto out; 708 } 709 710 err = -EACCES; 711 if ((rt->rt_flags & RTCF_BROADCAST) && 712 !sock_flag(sk, SOCK_BROADCAST)) 713 goto out; 714 if (connected) 715 sk_dst_set(sk, dst_clone(&rt->u.dst)); 716 } 717 718 if (msg->msg_flags&MSG_CONFIRM) 719 goto do_confirm; 720 back_from_confirm: 721 722 saddr = rt->rt_src; 723 if (!ipc.addr) 724 daddr = ipc.addr = rt->rt_dst; 725 726 lock_sock(sk); 727 if (unlikely(up->pending)) { 728 /* The socket is already corked while preparing it. */ 729 /* ... which is an evident application bug. --ANK */ 730 release_sock(sk); 731 732 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n"); 733 err = -EINVAL; 734 goto out; 735 } 736 /* 737 * Now cork the socket to pend data. 738 */ 739 inet->cork.fl.fl4_dst = daddr; 740 inet->cork.fl.fl_ip_dport = dport; 741 inet->cork.fl.fl4_src = saddr; 742 inet->cork.fl.fl_ip_sport = inet->sport; 743 up->pending = AF_INET; 744 745 do_append_data: 746 up->len += ulen; 747 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 748 err = ip_append_data(sk, getfrag, msg->msg_iov, ulen, 749 sizeof(struct udphdr), &ipc, &rt, 750 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 751 if (err) 752 udp_flush_pending_frames(sk); 753 else if (!corkreq) 754 err = udp_push_pending_frames(sk); 755 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 756 up->pending = 0; 757 release_sock(sk); 758 759 out: 760 ip_rt_put(rt); 761 if (free) 762 kfree(ipc.opt); 763 if (!err) 764 return len; 765 /* 766 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 767 * ENOBUFS might not be good (it's not tunable per se), but otherwise 768 * we don't have a good statistic (IpOutDiscards but it can be too many 769 * things). We could add another new stat but at least for now that 770 * seems like overkill. 771 */ 772 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 773 UDP_INC_STATS_USER(sock_net(sk), 774 UDP_MIB_SNDBUFERRORS, is_udplite); 775 } 776 return err; 777 778 do_confirm: 779 dst_confirm(&rt->u.dst); 780 if (!(msg->msg_flags&MSG_PROBE) || len) 781 goto back_from_confirm; 782 err = 0; 783 goto out; 784 } 785 786 int udp_sendpage(struct sock *sk, struct page *page, int offset, 787 size_t size, int flags) 788 { 789 struct udp_sock *up = udp_sk(sk); 790 int ret; 791 792 if (!up->pending) { 793 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 794 795 /* Call udp_sendmsg to specify destination address which 796 * sendpage interface can't pass. 797 * This will succeed only when the socket is connected. 798 */ 799 ret = udp_sendmsg(NULL, sk, &msg, 0); 800 if (ret < 0) 801 return ret; 802 } 803 804 lock_sock(sk); 805 806 if (unlikely(!up->pending)) { 807 release_sock(sk); 808 809 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n"); 810 return -EINVAL; 811 } 812 813 ret = ip_append_page(sk, page, offset, size, flags); 814 if (ret == -EOPNOTSUPP) { 815 release_sock(sk); 816 return sock_no_sendpage(sk->sk_socket, page, offset, 817 size, flags); 818 } 819 if (ret < 0) { 820 udp_flush_pending_frames(sk); 821 goto out; 822 } 823 824 up->len += size; 825 if (!(up->corkflag || (flags&MSG_MORE))) 826 ret = udp_push_pending_frames(sk); 827 if (!ret) 828 ret = size; 829 out: 830 release_sock(sk); 831 return ret; 832 } 833 834 /* 835 * IOCTL requests applicable to the UDP protocol 836 */ 837 838 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 839 { 840 switch (cmd) { 841 case SIOCOUTQ: 842 { 843 int amount = sk_wmem_alloc_get(sk); 844 845 return put_user(amount, (int __user *)arg); 846 } 847 848 case SIOCINQ: 849 { 850 struct sk_buff *skb; 851 unsigned long amount; 852 853 amount = 0; 854 spin_lock_bh(&sk->sk_receive_queue.lock); 855 skb = skb_peek(&sk->sk_receive_queue); 856 if (skb != NULL) { 857 /* 858 * We will only return the amount 859 * of this packet since that is all 860 * that will be read. 861 */ 862 amount = skb->len - sizeof(struct udphdr); 863 } 864 spin_unlock_bh(&sk->sk_receive_queue.lock); 865 return put_user(amount, (int __user *)arg); 866 } 867 868 default: 869 return -ENOIOCTLCMD; 870 } 871 872 return 0; 873 } 874 875 /* 876 * This should be easy, if there is something there we 877 * return it, otherwise we block. 878 */ 879 880 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 881 size_t len, int noblock, int flags, int *addr_len) 882 { 883 struct inet_sock *inet = inet_sk(sk); 884 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 885 struct sk_buff *skb; 886 unsigned int ulen, copied; 887 int peeked; 888 int err; 889 int is_udplite = IS_UDPLITE(sk); 890 891 /* 892 * Check any passed addresses 893 */ 894 if (addr_len) 895 *addr_len=sizeof(*sin); 896 897 if (flags & MSG_ERRQUEUE) 898 return ip_recv_error(sk, msg, len); 899 900 try_again: 901 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), 902 &peeked, &err); 903 if (!skb) 904 goto out; 905 906 ulen = skb->len - sizeof(struct udphdr); 907 copied = len; 908 if (copied > ulen) 909 copied = ulen; 910 else if (copied < ulen) 911 msg->msg_flags |= MSG_TRUNC; 912 913 /* 914 * If checksum is needed at all, try to do it while copying the 915 * data. If the data is truncated, or if we only want a partial 916 * coverage checksum (UDP-Lite), do it before the copy. 917 */ 918 919 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { 920 if (udp_lib_checksum_complete(skb)) 921 goto csum_copy_err; 922 } 923 924 if (skb_csum_unnecessary(skb)) 925 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), 926 msg->msg_iov, copied ); 927 else { 928 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); 929 930 if (err == -EINVAL) 931 goto csum_copy_err; 932 } 933 934 if (err) 935 goto out_free; 936 937 if (!peeked) 938 UDP_INC_STATS_USER(sock_net(sk), 939 UDP_MIB_INDATAGRAMS, is_udplite); 940 941 sock_recv_timestamp(msg, sk, skb); 942 943 /* Copy the address. */ 944 if (sin) 945 { 946 sin->sin_family = AF_INET; 947 sin->sin_port = udp_hdr(skb)->source; 948 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 949 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 950 } 951 if (inet->cmsg_flags) 952 ip_cmsg_recv(msg, skb); 953 954 err = copied; 955 if (flags & MSG_TRUNC) 956 err = ulen; 957 958 out_free: 959 lock_sock(sk); 960 skb_free_datagram(sk, skb); 961 release_sock(sk); 962 out: 963 return err; 964 965 csum_copy_err: 966 lock_sock(sk); 967 if (!skb_kill_datagram(sk, skb, flags)) 968 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 969 release_sock(sk); 970 971 if (noblock) 972 return -EAGAIN; 973 goto try_again; 974 } 975 976 977 int udp_disconnect(struct sock *sk, int flags) 978 { 979 struct inet_sock *inet = inet_sk(sk); 980 /* 981 * 1003.1g - break association. 982 */ 983 984 sk->sk_state = TCP_CLOSE; 985 inet->daddr = 0; 986 inet->dport = 0; 987 sk->sk_bound_dev_if = 0; 988 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 989 inet_reset_saddr(sk); 990 991 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 992 sk->sk_prot->unhash(sk); 993 inet->sport = 0; 994 } 995 sk_dst_reset(sk); 996 return 0; 997 } 998 999 void udp_lib_unhash(struct sock *sk) 1000 { 1001 if (sk_hashed(sk)) { 1002 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1003 unsigned int hash = udp_hashfn(sock_net(sk), sk->sk_hash); 1004 struct udp_hslot *hslot = &udptable->hash[hash]; 1005 1006 spin_lock_bh(&hslot->lock); 1007 if (sk_nulls_del_node_init_rcu(sk)) { 1008 inet_sk(sk)->num = 0; 1009 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1010 } 1011 spin_unlock_bh(&hslot->lock); 1012 } 1013 } 1014 EXPORT_SYMBOL(udp_lib_unhash); 1015 1016 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1017 { 1018 int is_udplite = IS_UDPLITE(sk); 1019 int rc; 1020 1021 if ((rc = sock_queue_rcv_skb(sk, skb)) < 0) { 1022 /* Note that an ENOMEM error is charged twice */ 1023 if (rc == -ENOMEM) { 1024 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1025 is_udplite); 1026 atomic_inc(&sk->sk_drops); 1027 } 1028 goto drop; 1029 } 1030 1031 return 0; 1032 1033 drop: 1034 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1035 kfree_skb(skb); 1036 return -1; 1037 } 1038 1039 /* returns: 1040 * -1: error 1041 * 0: success 1042 * >0: "udp encap" protocol resubmission 1043 * 1044 * Note that in the success and error cases, the skb is assumed to 1045 * have either been requeued or freed. 1046 */ 1047 int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) 1048 { 1049 struct udp_sock *up = udp_sk(sk); 1050 int rc; 1051 int is_udplite = IS_UDPLITE(sk); 1052 1053 /* 1054 * Charge it to the socket, dropping if the queue is full. 1055 */ 1056 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1057 goto drop; 1058 nf_reset(skb); 1059 1060 if (up->encap_type) { 1061 /* 1062 * This is an encapsulation socket so pass the skb to 1063 * the socket's udp_encap_rcv() hook. Otherwise, just 1064 * fall through and pass this up the UDP socket. 1065 * up->encap_rcv() returns the following value: 1066 * =0 if skb was successfully passed to the encap 1067 * handler or was discarded by it. 1068 * >0 if skb should be passed on to UDP. 1069 * <0 if skb should be resubmitted as proto -N 1070 */ 1071 1072 /* if we're overly short, let UDP handle it */ 1073 if (skb->len > sizeof(struct udphdr) && 1074 up->encap_rcv != NULL) { 1075 int ret; 1076 1077 ret = (*up->encap_rcv)(sk, skb); 1078 if (ret <= 0) { 1079 UDP_INC_STATS_BH(sock_net(sk), 1080 UDP_MIB_INDATAGRAMS, 1081 is_udplite); 1082 return -ret; 1083 } 1084 } 1085 1086 /* FALLTHROUGH -- it's a UDP Packet */ 1087 } 1088 1089 /* 1090 * UDP-Lite specific tests, ignored on UDP sockets 1091 */ 1092 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1093 1094 /* 1095 * MIB statistics other than incrementing the error count are 1096 * disabled for the following two types of errors: these depend 1097 * on the application settings, not on the functioning of the 1098 * protocol stack as such. 1099 * 1100 * RFC 3828 here recommends (sec 3.3): "There should also be a 1101 * way ... to ... at least let the receiving application block 1102 * delivery of packets with coverage values less than a value 1103 * provided by the application." 1104 */ 1105 if (up->pcrlen == 0) { /* full coverage was set */ 1106 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage " 1107 "%d while full coverage %d requested\n", 1108 UDP_SKB_CB(skb)->cscov, skb->len); 1109 goto drop; 1110 } 1111 /* The next case involves violating the min. coverage requested 1112 * by the receiver. This is subtle: if receiver wants x and x is 1113 * greater than the buffersize/MTU then receiver will complain 1114 * that it wants x while sender emits packets of smaller size y. 1115 * Therefore the above ...()->partial_cov statement is essential. 1116 */ 1117 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1118 LIMIT_NETDEBUG(KERN_WARNING 1119 "UDPLITE: coverage %d too small, need min %d\n", 1120 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1121 goto drop; 1122 } 1123 } 1124 1125 if (sk->sk_filter) { 1126 if (udp_lib_checksum_complete(skb)) 1127 goto drop; 1128 } 1129 1130 rc = 0; 1131 1132 bh_lock_sock(sk); 1133 if (!sock_owned_by_user(sk)) 1134 rc = __udp_queue_rcv_skb(sk, skb); 1135 else 1136 sk_add_backlog(sk, skb); 1137 bh_unlock_sock(sk); 1138 1139 return rc; 1140 1141 drop: 1142 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1143 kfree_skb(skb); 1144 return -1; 1145 } 1146 1147 /* 1148 * Multicasts and broadcasts go to each listener. 1149 * 1150 * Note: called only from the BH handler context, 1151 * so we don't need to lock the hashes. 1152 */ 1153 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 1154 struct udphdr *uh, 1155 __be32 saddr, __be32 daddr, 1156 struct udp_table *udptable) 1157 { 1158 struct sock *sk; 1159 struct udp_hslot *hslot = &udptable->hash[udp_hashfn(net, ntohs(uh->dest))]; 1160 int dif; 1161 1162 spin_lock(&hslot->lock); 1163 sk = sk_nulls_head(&hslot->head); 1164 dif = skb->dev->ifindex; 1165 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); 1166 if (sk) { 1167 struct sock *sknext = NULL; 1168 1169 do { 1170 struct sk_buff *skb1 = skb; 1171 1172 sknext = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest, 1173 daddr, uh->source, saddr, 1174 dif); 1175 if (sknext) 1176 skb1 = skb_clone(skb, GFP_ATOMIC); 1177 1178 if (skb1) { 1179 int ret = udp_queue_rcv_skb(sk, skb1); 1180 if (ret > 0) 1181 /* we should probably re-process instead 1182 * of dropping packets here. */ 1183 kfree_skb(skb1); 1184 } 1185 sk = sknext; 1186 } while (sknext); 1187 } else 1188 consume_skb(skb); 1189 spin_unlock(&hslot->lock); 1190 return 0; 1191 } 1192 1193 /* Initialize UDP checksum. If exited with zero value (success), 1194 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1195 * Otherwise, csum completion requires chacksumming packet body, 1196 * including udp header and folding it to skb->csum. 1197 */ 1198 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 1199 int proto) 1200 { 1201 const struct iphdr *iph; 1202 int err; 1203 1204 UDP_SKB_CB(skb)->partial_cov = 0; 1205 UDP_SKB_CB(skb)->cscov = skb->len; 1206 1207 if (proto == IPPROTO_UDPLITE) { 1208 err = udplite_checksum_init(skb, uh); 1209 if (err) 1210 return err; 1211 } 1212 1213 iph = ip_hdr(skb); 1214 if (uh->check == 0) { 1215 skb->ip_summed = CHECKSUM_UNNECESSARY; 1216 } else if (skb->ip_summed == CHECKSUM_COMPLETE) { 1217 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 1218 proto, skb->csum)) 1219 skb->ip_summed = CHECKSUM_UNNECESSARY; 1220 } 1221 if (!skb_csum_unnecessary(skb)) 1222 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, 1223 skb->len, proto, 0); 1224 /* Probably, we should checksum udp header (it should be in cache 1225 * in any case) and data in tiny packets (< rx copybreak). 1226 */ 1227 1228 return 0; 1229 } 1230 1231 /* 1232 * All we need to do is get the socket, and then do a checksum. 1233 */ 1234 1235 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 1236 int proto) 1237 { 1238 struct sock *sk; 1239 struct udphdr *uh; 1240 unsigned short ulen; 1241 struct rtable *rt = skb_rtable(skb); 1242 __be32 saddr, daddr; 1243 struct net *net = dev_net(skb->dev); 1244 1245 /* 1246 * Validate the packet. 1247 */ 1248 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1249 goto drop; /* No space for header. */ 1250 1251 uh = udp_hdr(skb); 1252 ulen = ntohs(uh->len); 1253 if (ulen > skb->len) 1254 goto short_packet; 1255 1256 if (proto == IPPROTO_UDP) { 1257 /* UDP validates ulen. */ 1258 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1259 goto short_packet; 1260 uh = udp_hdr(skb); 1261 } 1262 1263 if (udp4_csum_init(skb, uh, proto)) 1264 goto csum_error; 1265 1266 saddr = ip_hdr(skb)->saddr; 1267 daddr = ip_hdr(skb)->daddr; 1268 1269 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1270 return __udp4_lib_mcast_deliver(net, skb, uh, 1271 saddr, daddr, udptable); 1272 1273 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 1274 1275 if (sk != NULL) { 1276 int ret = udp_queue_rcv_skb(sk, skb); 1277 sock_put(sk); 1278 1279 /* a return value > 0 means to resubmit the input, but 1280 * it wants the return to be -protocol, or 0 1281 */ 1282 if (ret > 0) 1283 return -ret; 1284 return 0; 1285 } 1286 1287 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1288 goto drop; 1289 nf_reset(skb); 1290 1291 /* No socket. Drop packet silently, if checksum is wrong */ 1292 if (udp_lib_checksum_complete(skb)) 1293 goto csum_error; 1294 1295 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 1296 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1297 1298 /* 1299 * Hmm. We got an UDP packet to a port to which we 1300 * don't wanna listen. Ignore it. 1301 */ 1302 kfree_skb(skb); 1303 return 0; 1304 1305 short_packet: 1306 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 1307 proto == IPPROTO_UDPLITE ? "-Lite" : "", 1308 &saddr, 1309 ntohs(uh->source), 1310 ulen, 1311 skb->len, 1312 &daddr, 1313 ntohs(uh->dest)); 1314 goto drop; 1315 1316 csum_error: 1317 /* 1318 * RFC1122: OK. Discards the bad packet silently (as far as 1319 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1320 */ 1321 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 1322 proto == IPPROTO_UDPLITE ? "-Lite" : "", 1323 &saddr, 1324 ntohs(uh->source), 1325 &daddr, 1326 ntohs(uh->dest), 1327 ulen); 1328 drop: 1329 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1330 kfree_skb(skb); 1331 return 0; 1332 } 1333 1334 int udp_rcv(struct sk_buff *skb) 1335 { 1336 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 1337 } 1338 1339 void udp_destroy_sock(struct sock *sk) 1340 { 1341 lock_sock(sk); 1342 udp_flush_pending_frames(sk); 1343 release_sock(sk); 1344 } 1345 1346 /* 1347 * Socket option code for UDP 1348 */ 1349 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 1350 char __user *optval, int optlen, 1351 int (*push_pending_frames)(struct sock *)) 1352 { 1353 struct udp_sock *up = udp_sk(sk); 1354 int val; 1355 int err = 0; 1356 int is_udplite = IS_UDPLITE(sk); 1357 1358 if (optlen<sizeof(int)) 1359 return -EINVAL; 1360 1361 if (get_user(val, (int __user *)optval)) 1362 return -EFAULT; 1363 1364 switch (optname) { 1365 case UDP_CORK: 1366 if (val != 0) { 1367 up->corkflag = 1; 1368 } else { 1369 up->corkflag = 0; 1370 lock_sock(sk); 1371 (*push_pending_frames)(sk); 1372 release_sock(sk); 1373 } 1374 break; 1375 1376 case UDP_ENCAP: 1377 switch (val) { 1378 case 0: 1379 case UDP_ENCAP_ESPINUDP: 1380 case UDP_ENCAP_ESPINUDP_NON_IKE: 1381 up->encap_rcv = xfrm4_udp_encap_rcv; 1382 /* FALLTHROUGH */ 1383 case UDP_ENCAP_L2TPINUDP: 1384 up->encap_type = val; 1385 break; 1386 default: 1387 err = -ENOPROTOOPT; 1388 break; 1389 } 1390 break; 1391 1392 /* 1393 * UDP-Lite's partial checksum coverage (RFC 3828). 1394 */ 1395 /* The sender sets actual checksum coverage length via this option. 1396 * The case coverage > packet length is handled by send module. */ 1397 case UDPLITE_SEND_CSCOV: 1398 if (!is_udplite) /* Disable the option on UDP sockets */ 1399 return -ENOPROTOOPT; 1400 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 1401 val = 8; 1402 else if (val > USHORT_MAX) 1403 val = USHORT_MAX; 1404 up->pcslen = val; 1405 up->pcflag |= UDPLITE_SEND_CC; 1406 break; 1407 1408 /* The receiver specifies a minimum checksum coverage value. To make 1409 * sense, this should be set to at least 8 (as done below). If zero is 1410 * used, this again means full checksum coverage. */ 1411 case UDPLITE_RECV_CSCOV: 1412 if (!is_udplite) /* Disable the option on UDP sockets */ 1413 return -ENOPROTOOPT; 1414 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 1415 val = 8; 1416 else if (val > USHORT_MAX) 1417 val = USHORT_MAX; 1418 up->pcrlen = val; 1419 up->pcflag |= UDPLITE_RECV_CC; 1420 break; 1421 1422 default: 1423 err = -ENOPROTOOPT; 1424 break; 1425 } 1426 1427 return err; 1428 } 1429 1430 int udp_setsockopt(struct sock *sk, int level, int optname, 1431 char __user *optval, int optlen) 1432 { 1433 if (level == SOL_UDP || level == SOL_UDPLITE) 1434 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1435 udp_push_pending_frames); 1436 return ip_setsockopt(sk, level, optname, optval, optlen); 1437 } 1438 1439 #ifdef CONFIG_COMPAT 1440 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 1441 char __user *optval, int optlen) 1442 { 1443 if (level == SOL_UDP || level == SOL_UDPLITE) 1444 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1445 udp_push_pending_frames); 1446 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 1447 } 1448 #endif 1449 1450 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 1451 char __user *optval, int __user *optlen) 1452 { 1453 struct udp_sock *up = udp_sk(sk); 1454 int val, len; 1455 1456 if (get_user(len,optlen)) 1457 return -EFAULT; 1458 1459 len = min_t(unsigned int, len, sizeof(int)); 1460 1461 if (len < 0) 1462 return -EINVAL; 1463 1464 switch (optname) { 1465 case UDP_CORK: 1466 val = up->corkflag; 1467 break; 1468 1469 case UDP_ENCAP: 1470 val = up->encap_type; 1471 break; 1472 1473 /* The following two cannot be changed on UDP sockets, the return is 1474 * always 0 (which corresponds to the full checksum coverage of UDP). */ 1475 case UDPLITE_SEND_CSCOV: 1476 val = up->pcslen; 1477 break; 1478 1479 case UDPLITE_RECV_CSCOV: 1480 val = up->pcrlen; 1481 break; 1482 1483 default: 1484 return -ENOPROTOOPT; 1485 } 1486 1487 if (put_user(len, optlen)) 1488 return -EFAULT; 1489 if (copy_to_user(optval, &val,len)) 1490 return -EFAULT; 1491 return 0; 1492 } 1493 1494 int udp_getsockopt(struct sock *sk, int level, int optname, 1495 char __user *optval, int __user *optlen) 1496 { 1497 if (level == SOL_UDP || level == SOL_UDPLITE) 1498 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1499 return ip_getsockopt(sk, level, optname, optval, optlen); 1500 } 1501 1502 #ifdef CONFIG_COMPAT 1503 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 1504 char __user *optval, int __user *optlen) 1505 { 1506 if (level == SOL_UDP || level == SOL_UDPLITE) 1507 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1508 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 1509 } 1510 #endif 1511 /** 1512 * udp_poll - wait for a UDP event. 1513 * @file - file struct 1514 * @sock - socket 1515 * @wait - poll table 1516 * 1517 * This is same as datagram poll, except for the special case of 1518 * blocking sockets. If application is using a blocking fd 1519 * and a packet with checksum error is in the queue; 1520 * then it could get return from select indicating data available 1521 * but then block when reading it. Add special case code 1522 * to work around these arguably broken applications. 1523 */ 1524 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 1525 { 1526 unsigned int mask = datagram_poll(file, sock, wait); 1527 struct sock *sk = sock->sk; 1528 int is_lite = IS_UDPLITE(sk); 1529 1530 /* Check for false positives due to checksum errors */ 1531 if ( (mask & POLLRDNORM) && 1532 !(file->f_flags & O_NONBLOCK) && 1533 !(sk->sk_shutdown & RCV_SHUTDOWN)){ 1534 struct sk_buff_head *rcvq = &sk->sk_receive_queue; 1535 struct sk_buff *skb; 1536 1537 spin_lock_bh(&rcvq->lock); 1538 while ((skb = skb_peek(rcvq)) != NULL && 1539 udp_lib_checksum_complete(skb)) { 1540 UDP_INC_STATS_BH(sock_net(sk), 1541 UDP_MIB_INERRORS, is_lite); 1542 __skb_unlink(skb, rcvq); 1543 kfree_skb(skb); 1544 } 1545 spin_unlock_bh(&rcvq->lock); 1546 1547 /* nothing to see, move along */ 1548 if (skb == NULL) 1549 mask &= ~(POLLIN | POLLRDNORM); 1550 } 1551 1552 return mask; 1553 1554 } 1555 1556 struct proto udp_prot = { 1557 .name = "UDP", 1558 .owner = THIS_MODULE, 1559 .close = udp_lib_close, 1560 .connect = ip4_datagram_connect, 1561 .disconnect = udp_disconnect, 1562 .ioctl = udp_ioctl, 1563 .destroy = udp_destroy_sock, 1564 .setsockopt = udp_setsockopt, 1565 .getsockopt = udp_getsockopt, 1566 .sendmsg = udp_sendmsg, 1567 .recvmsg = udp_recvmsg, 1568 .sendpage = udp_sendpage, 1569 .backlog_rcv = __udp_queue_rcv_skb, 1570 .hash = udp_lib_hash, 1571 .unhash = udp_lib_unhash, 1572 .get_port = udp_v4_get_port, 1573 .memory_allocated = &udp_memory_allocated, 1574 .sysctl_mem = sysctl_udp_mem, 1575 .sysctl_wmem = &sysctl_udp_wmem_min, 1576 .sysctl_rmem = &sysctl_udp_rmem_min, 1577 .obj_size = sizeof(struct udp_sock), 1578 .slab_flags = SLAB_DESTROY_BY_RCU, 1579 .h.udp_table = &udp_table, 1580 #ifdef CONFIG_COMPAT 1581 .compat_setsockopt = compat_udp_setsockopt, 1582 .compat_getsockopt = compat_udp_getsockopt, 1583 #endif 1584 }; 1585 1586 /* ------------------------------------------------------------------------ */ 1587 #ifdef CONFIG_PROC_FS 1588 1589 static struct sock *udp_get_first(struct seq_file *seq, int start) 1590 { 1591 struct sock *sk; 1592 struct udp_iter_state *state = seq->private; 1593 struct net *net = seq_file_net(seq); 1594 1595 for (state->bucket = start; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) { 1596 struct hlist_nulls_node *node; 1597 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; 1598 spin_lock_bh(&hslot->lock); 1599 sk_nulls_for_each(sk, node, &hslot->head) { 1600 if (!net_eq(sock_net(sk), net)) 1601 continue; 1602 if (sk->sk_family == state->family) 1603 goto found; 1604 } 1605 spin_unlock_bh(&hslot->lock); 1606 } 1607 sk = NULL; 1608 found: 1609 return sk; 1610 } 1611 1612 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 1613 { 1614 struct udp_iter_state *state = seq->private; 1615 struct net *net = seq_file_net(seq); 1616 1617 do { 1618 sk = sk_nulls_next(sk); 1619 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); 1620 1621 if (!sk) { 1622 if (state->bucket < UDP_HTABLE_SIZE) 1623 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 1624 return udp_get_first(seq, state->bucket + 1); 1625 } 1626 return sk; 1627 } 1628 1629 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 1630 { 1631 struct sock *sk = udp_get_first(seq, 0); 1632 1633 if (sk) 1634 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 1635 --pos; 1636 return pos ? NULL : sk; 1637 } 1638 1639 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 1640 { 1641 struct udp_iter_state *state = seq->private; 1642 state->bucket = UDP_HTABLE_SIZE; 1643 1644 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1645 } 1646 1647 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1648 { 1649 struct sock *sk; 1650 1651 if (v == SEQ_START_TOKEN) 1652 sk = udp_get_idx(seq, 0); 1653 else 1654 sk = udp_get_next(seq, v); 1655 1656 ++*pos; 1657 return sk; 1658 } 1659 1660 static void udp_seq_stop(struct seq_file *seq, void *v) 1661 { 1662 struct udp_iter_state *state = seq->private; 1663 1664 if (state->bucket < UDP_HTABLE_SIZE) 1665 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 1666 } 1667 1668 static int udp_seq_open(struct inode *inode, struct file *file) 1669 { 1670 struct udp_seq_afinfo *afinfo = PDE(inode)->data; 1671 struct udp_iter_state *s; 1672 int err; 1673 1674 err = seq_open_net(inode, file, &afinfo->seq_ops, 1675 sizeof(struct udp_iter_state)); 1676 if (err < 0) 1677 return err; 1678 1679 s = ((struct seq_file *)file->private_data)->private; 1680 s->family = afinfo->family; 1681 s->udp_table = afinfo->udp_table; 1682 return err; 1683 } 1684 1685 /* ------------------------------------------------------------------------ */ 1686 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) 1687 { 1688 struct proc_dir_entry *p; 1689 int rc = 0; 1690 1691 afinfo->seq_fops.open = udp_seq_open; 1692 afinfo->seq_fops.read = seq_read; 1693 afinfo->seq_fops.llseek = seq_lseek; 1694 afinfo->seq_fops.release = seq_release_net; 1695 1696 afinfo->seq_ops.start = udp_seq_start; 1697 afinfo->seq_ops.next = udp_seq_next; 1698 afinfo->seq_ops.stop = udp_seq_stop; 1699 1700 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 1701 &afinfo->seq_fops, afinfo); 1702 if (!p) 1703 rc = -ENOMEM; 1704 return rc; 1705 } 1706 1707 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 1708 { 1709 proc_net_remove(net, afinfo->name); 1710 } 1711 1712 /* ------------------------------------------------------------------------ */ 1713 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 1714 int bucket, int *len) 1715 { 1716 struct inet_sock *inet = inet_sk(sp); 1717 __be32 dest = inet->daddr; 1718 __be32 src = inet->rcv_saddr; 1719 __u16 destp = ntohs(inet->dport); 1720 __u16 srcp = ntohs(inet->sport); 1721 1722 seq_printf(f, "%4d: %08X:%04X %08X:%04X" 1723 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n", 1724 bucket, src, srcp, dest, destp, sp->sk_state, 1725 sk_wmem_alloc_get(sp), 1726 sk_rmem_alloc_get(sp), 1727 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), 1728 atomic_read(&sp->sk_refcnt), sp, 1729 atomic_read(&sp->sk_drops), len); 1730 } 1731 1732 int udp4_seq_show(struct seq_file *seq, void *v) 1733 { 1734 if (v == SEQ_START_TOKEN) 1735 seq_printf(seq, "%-127s\n", 1736 " sl local_address rem_address st tx_queue " 1737 "rx_queue tr tm->when retrnsmt uid timeout " 1738 "inode ref pointer drops"); 1739 else { 1740 struct udp_iter_state *state = seq->private; 1741 int len; 1742 1743 udp4_format_sock(v, seq, state->bucket, &len); 1744 seq_printf(seq, "%*s\n", 127 - len ,""); 1745 } 1746 return 0; 1747 } 1748 1749 /* ------------------------------------------------------------------------ */ 1750 static struct udp_seq_afinfo udp4_seq_afinfo = { 1751 .name = "udp", 1752 .family = AF_INET, 1753 .udp_table = &udp_table, 1754 .seq_fops = { 1755 .owner = THIS_MODULE, 1756 }, 1757 .seq_ops = { 1758 .show = udp4_seq_show, 1759 }, 1760 }; 1761 1762 static int udp4_proc_init_net(struct net *net) 1763 { 1764 return udp_proc_register(net, &udp4_seq_afinfo); 1765 } 1766 1767 static void udp4_proc_exit_net(struct net *net) 1768 { 1769 udp_proc_unregister(net, &udp4_seq_afinfo); 1770 } 1771 1772 static struct pernet_operations udp4_net_ops = { 1773 .init = udp4_proc_init_net, 1774 .exit = udp4_proc_exit_net, 1775 }; 1776 1777 int __init udp4_proc_init(void) 1778 { 1779 return register_pernet_subsys(&udp4_net_ops); 1780 } 1781 1782 void udp4_proc_exit(void) 1783 { 1784 unregister_pernet_subsys(&udp4_net_ops); 1785 } 1786 #endif /* CONFIG_PROC_FS */ 1787 1788 void __init udp_table_init(struct udp_table *table) 1789 { 1790 int i; 1791 1792 for (i = 0; i < UDP_HTABLE_SIZE; i++) { 1793 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); 1794 spin_lock_init(&table->hash[i].lock); 1795 } 1796 } 1797 1798 void __init udp_init(void) 1799 { 1800 unsigned long nr_pages, limit; 1801 1802 udp_table_init(&udp_table); 1803 /* Set the pressure threshold up by the same strategy of TCP. It is a 1804 * fraction of global memory that is up to 1/2 at 256 MB, decreasing 1805 * toward zero with the amount of memory, with a floor of 128 pages. 1806 */ 1807 nr_pages = totalram_pages - totalhigh_pages; 1808 limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); 1809 limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11); 1810 limit = max(limit, 128UL); 1811 sysctl_udp_mem[0] = limit / 4 * 3; 1812 sysctl_udp_mem[1] = limit; 1813 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 1814 1815 sysctl_udp_rmem_min = SK_MEM_QUANTUM; 1816 sysctl_udp_wmem_min = SK_MEM_QUANTUM; 1817 } 1818 1819 EXPORT_SYMBOL(udp_disconnect); 1820 EXPORT_SYMBOL(udp_ioctl); 1821 EXPORT_SYMBOL(udp_prot); 1822 EXPORT_SYMBOL(udp_sendmsg); 1823 EXPORT_SYMBOL(udp_lib_getsockopt); 1824 EXPORT_SYMBOL(udp_lib_setsockopt); 1825 EXPORT_SYMBOL(udp_poll); 1826 EXPORT_SYMBOL(udp_lib_get_port); 1827 1828 #ifdef CONFIG_PROC_FS 1829 EXPORT_SYMBOL(udp_proc_register); 1830 EXPORT_SYMBOL(udp_proc_unregister); 1831 #endif 1832