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 #define pr_fmt(fmt) "UDP: " fmt 81 82 #include <asm/uaccess.h> 83 #include <asm/ioctls.h> 84 #include <linux/bootmem.h> 85 #include <linux/highmem.h> 86 #include <linux/swap.h> 87 #include <linux/types.h> 88 #include <linux/fcntl.h> 89 #include <linux/module.h> 90 #include <linux/socket.h> 91 #include <linux/sockios.h> 92 #include <linux/igmp.h> 93 #include <linux/in.h> 94 #include <linux/errno.h> 95 #include <linux/timer.h> 96 #include <linux/mm.h> 97 #include <linux/inet.h> 98 #include <linux/netdevice.h> 99 #include <linux/slab.h> 100 #include <net/tcp_states.h> 101 #include <linux/skbuff.h> 102 #include <linux/proc_fs.h> 103 #include <linux/seq_file.h> 104 #include <net/net_namespace.h> 105 #include <net/icmp.h> 106 #include <net/route.h> 107 #include <net/checksum.h> 108 #include <net/xfrm.h> 109 #include <trace/events/udp.h> 110 #include <linux/static_key.h> 111 #include <trace/events/skb.h> 112 #include <net/busy_poll.h> 113 #include "udp_impl.h" 114 115 struct udp_table udp_table __read_mostly; 116 EXPORT_SYMBOL(udp_table); 117 118 long sysctl_udp_mem[3] __read_mostly; 119 EXPORT_SYMBOL(sysctl_udp_mem); 120 121 int sysctl_udp_rmem_min __read_mostly; 122 EXPORT_SYMBOL(sysctl_udp_rmem_min); 123 124 int sysctl_udp_wmem_min __read_mostly; 125 EXPORT_SYMBOL(sysctl_udp_wmem_min); 126 127 atomic_long_t udp_memory_allocated; 128 EXPORT_SYMBOL(udp_memory_allocated); 129 130 #define MAX_UDP_PORTS 65536 131 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 132 133 static int udp_lib_lport_inuse(struct net *net, __u16 num, 134 const struct udp_hslot *hslot, 135 unsigned long *bitmap, 136 struct sock *sk, 137 int (*saddr_comp)(const struct sock *sk1, 138 const struct sock *sk2), 139 unsigned int log) 140 { 141 struct sock *sk2; 142 struct hlist_nulls_node *node; 143 kuid_t uid = sock_i_uid(sk); 144 145 sk_nulls_for_each(sk2, node, &hslot->head) 146 if (net_eq(sock_net(sk2), net) && 147 sk2 != sk && 148 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 149 (!sk2->sk_reuse || !sk->sk_reuse) && 150 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 151 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 152 (!sk2->sk_reuseport || !sk->sk_reuseport || 153 !uid_eq(uid, sock_i_uid(sk2))) && 154 (*saddr_comp)(sk, sk2)) { 155 if (bitmap) 156 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 157 bitmap); 158 else 159 return 1; 160 } 161 return 0; 162 } 163 164 /* 165 * Note: we still hold spinlock of primary hash chain, so no other writer 166 * can insert/delete a socket with local_port == num 167 */ 168 static int udp_lib_lport_inuse2(struct net *net, __u16 num, 169 struct udp_hslot *hslot2, 170 struct sock *sk, 171 int (*saddr_comp)(const struct sock *sk1, 172 const struct sock *sk2)) 173 { 174 struct sock *sk2; 175 struct hlist_nulls_node *node; 176 kuid_t uid = sock_i_uid(sk); 177 int res = 0; 178 179 spin_lock(&hslot2->lock); 180 udp_portaddr_for_each_entry(sk2, node, &hslot2->head) 181 if (net_eq(sock_net(sk2), net) && 182 sk2 != sk && 183 (udp_sk(sk2)->udp_port_hash == num) && 184 (!sk2->sk_reuse || !sk->sk_reuse) && 185 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 186 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 187 (!sk2->sk_reuseport || !sk->sk_reuseport || 188 !uid_eq(uid, sock_i_uid(sk2))) && 189 (*saddr_comp)(sk, sk2)) { 190 res = 1; 191 break; 192 } 193 spin_unlock(&hslot2->lock); 194 return res; 195 } 196 197 /** 198 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 199 * 200 * @sk: socket struct in question 201 * @snum: port number to look up 202 * @saddr_comp: AF-dependent comparison of bound local IP addresses 203 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 204 * with NULL address 205 */ 206 int udp_lib_get_port(struct sock *sk, unsigned short snum, 207 int (*saddr_comp)(const struct sock *sk1, 208 const struct sock *sk2), 209 unsigned int hash2_nulladdr) 210 { 211 struct udp_hslot *hslot, *hslot2; 212 struct udp_table *udptable = sk->sk_prot->h.udp_table; 213 int error = 1; 214 struct net *net = sock_net(sk); 215 216 if (!snum) { 217 int low, high, remaining; 218 unsigned int rand; 219 unsigned short first, last; 220 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 221 222 inet_get_local_port_range(&low, &high); 223 remaining = (high - low) + 1; 224 225 rand = net_random(); 226 first = (((u64)rand * remaining) >> 32) + low; 227 /* 228 * force rand to be an odd multiple of UDP_HTABLE_SIZE 229 */ 230 rand = (rand | 1) * (udptable->mask + 1); 231 last = first + udptable->mask + 1; 232 do { 233 hslot = udp_hashslot(udptable, net, first); 234 bitmap_zero(bitmap, PORTS_PER_CHAIN); 235 spin_lock_bh(&hslot->lock); 236 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 237 saddr_comp, udptable->log); 238 239 snum = first; 240 /* 241 * Iterate on all possible values of snum for this hash. 242 * Using steps of an odd multiple of UDP_HTABLE_SIZE 243 * give us randomization and full range coverage. 244 */ 245 do { 246 if (low <= snum && snum <= high && 247 !test_bit(snum >> udptable->log, bitmap) && 248 !inet_is_reserved_local_port(snum)) 249 goto found; 250 snum += rand; 251 } while (snum != first); 252 spin_unlock_bh(&hslot->lock); 253 } while (++first != last); 254 goto fail; 255 } else { 256 hslot = udp_hashslot(udptable, net, snum); 257 spin_lock_bh(&hslot->lock); 258 if (hslot->count > 10) { 259 int exist; 260 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 261 262 slot2 &= udptable->mask; 263 hash2_nulladdr &= udptable->mask; 264 265 hslot2 = udp_hashslot2(udptable, slot2); 266 if (hslot->count < hslot2->count) 267 goto scan_primary_hash; 268 269 exist = udp_lib_lport_inuse2(net, snum, hslot2, 270 sk, saddr_comp); 271 if (!exist && (hash2_nulladdr != slot2)) { 272 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 273 exist = udp_lib_lport_inuse2(net, snum, hslot2, 274 sk, saddr_comp); 275 } 276 if (exist) 277 goto fail_unlock; 278 else 279 goto found; 280 } 281 scan_primary_hash: 282 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 283 saddr_comp, 0)) 284 goto fail_unlock; 285 } 286 found: 287 inet_sk(sk)->inet_num = snum; 288 udp_sk(sk)->udp_port_hash = snum; 289 udp_sk(sk)->udp_portaddr_hash ^= snum; 290 if (sk_unhashed(sk)) { 291 sk_nulls_add_node_rcu(sk, &hslot->head); 292 hslot->count++; 293 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 294 295 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 296 spin_lock(&hslot2->lock); 297 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 298 &hslot2->head); 299 hslot2->count++; 300 spin_unlock(&hslot2->lock); 301 } 302 error = 0; 303 fail_unlock: 304 spin_unlock_bh(&hslot->lock); 305 fail: 306 return error; 307 } 308 EXPORT_SYMBOL(udp_lib_get_port); 309 310 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 311 { 312 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 313 314 return (!ipv6_only_sock(sk2) && 315 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr || 316 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr)); 317 } 318 319 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr, 320 unsigned int port) 321 { 322 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 323 } 324 325 int udp_v4_get_port(struct sock *sk, unsigned short snum) 326 { 327 unsigned int hash2_nulladdr = 328 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 329 unsigned int hash2_partial = 330 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 331 332 /* precompute partial secondary hash */ 333 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 334 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr); 335 } 336 337 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr, 338 unsigned short hnum, 339 __be16 sport, __be32 daddr, __be16 dport, int dif) 340 { 341 int score = -1; 342 343 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && 344 !ipv6_only_sock(sk)) { 345 struct inet_sock *inet = inet_sk(sk); 346 347 score = (sk->sk_family == PF_INET ? 2 : 1); 348 if (inet->inet_rcv_saddr) { 349 if (inet->inet_rcv_saddr != daddr) 350 return -1; 351 score += 4; 352 } 353 if (inet->inet_daddr) { 354 if (inet->inet_daddr != saddr) 355 return -1; 356 score += 4; 357 } 358 if (inet->inet_dport) { 359 if (inet->inet_dport != sport) 360 return -1; 361 score += 4; 362 } 363 if (sk->sk_bound_dev_if) { 364 if (sk->sk_bound_dev_if != dif) 365 return -1; 366 score += 4; 367 } 368 } 369 return score; 370 } 371 372 /* 373 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num) 374 */ 375 static inline int compute_score2(struct sock *sk, struct net *net, 376 __be32 saddr, __be16 sport, 377 __be32 daddr, unsigned int hnum, int dif) 378 { 379 int score = -1; 380 381 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) { 382 struct inet_sock *inet = inet_sk(sk); 383 384 if (inet->inet_rcv_saddr != daddr) 385 return -1; 386 if (inet->inet_num != hnum) 387 return -1; 388 389 score = (sk->sk_family == PF_INET ? 2 : 1); 390 if (inet->inet_daddr) { 391 if (inet->inet_daddr != saddr) 392 return -1; 393 score += 4; 394 } 395 if (inet->inet_dport) { 396 if (inet->inet_dport != sport) 397 return -1; 398 score += 4; 399 } 400 if (sk->sk_bound_dev_if) { 401 if (sk->sk_bound_dev_if != dif) 402 return -1; 403 score += 4; 404 } 405 } 406 return score; 407 } 408 409 410 /* called with read_rcu_lock() */ 411 static struct sock *udp4_lib_lookup2(struct net *net, 412 __be32 saddr, __be16 sport, 413 __be32 daddr, unsigned int hnum, int dif, 414 struct udp_hslot *hslot2, unsigned int slot2) 415 { 416 struct sock *sk, *result; 417 struct hlist_nulls_node *node; 418 int score, badness, matches = 0, reuseport = 0; 419 u32 hash = 0; 420 421 begin: 422 result = NULL; 423 badness = 0; 424 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { 425 score = compute_score2(sk, net, saddr, sport, 426 daddr, hnum, dif); 427 if (score > badness) { 428 result = sk; 429 badness = score; 430 reuseport = sk->sk_reuseport; 431 if (reuseport) { 432 hash = inet_ehashfn(net, daddr, hnum, 433 saddr, sport); 434 matches = 1; 435 } 436 } else if (score == badness && reuseport) { 437 matches++; 438 if (((u64)hash * matches) >> 32 == 0) 439 result = sk; 440 hash = next_pseudo_random32(hash); 441 } 442 } 443 /* 444 * if the nulls value we got at the end of this lookup is 445 * not the expected one, we must restart lookup. 446 * We probably met an item that was moved to another chain. 447 */ 448 if (get_nulls_value(node) != slot2) 449 goto begin; 450 if (result) { 451 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 452 result = NULL; 453 else if (unlikely(compute_score2(result, net, saddr, sport, 454 daddr, hnum, dif) < badness)) { 455 sock_put(result); 456 goto begin; 457 } 458 } 459 return result; 460 } 461 462 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 463 * harder than this. -DaveM 464 */ 465 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 466 __be16 sport, __be32 daddr, __be16 dport, 467 int dif, struct udp_table *udptable) 468 { 469 struct sock *sk, *result; 470 struct hlist_nulls_node *node; 471 unsigned short hnum = ntohs(dport); 472 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); 473 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; 474 int score, badness, matches = 0, reuseport = 0; 475 u32 hash = 0; 476 477 rcu_read_lock(); 478 if (hslot->count > 10) { 479 hash2 = udp4_portaddr_hash(net, daddr, hnum); 480 slot2 = hash2 & udptable->mask; 481 hslot2 = &udptable->hash2[slot2]; 482 if (hslot->count < hslot2->count) 483 goto begin; 484 485 result = udp4_lib_lookup2(net, saddr, sport, 486 daddr, hnum, dif, 487 hslot2, slot2); 488 if (!result) { 489 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 490 slot2 = hash2 & udptable->mask; 491 hslot2 = &udptable->hash2[slot2]; 492 if (hslot->count < hslot2->count) 493 goto begin; 494 495 result = udp4_lib_lookup2(net, saddr, sport, 496 htonl(INADDR_ANY), hnum, dif, 497 hslot2, slot2); 498 } 499 rcu_read_unlock(); 500 return result; 501 } 502 begin: 503 result = NULL; 504 badness = 0; 505 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 506 score = compute_score(sk, net, saddr, hnum, sport, 507 daddr, dport, dif); 508 if (score > badness) { 509 result = sk; 510 badness = score; 511 reuseport = sk->sk_reuseport; 512 if (reuseport) { 513 hash = inet_ehashfn(net, daddr, hnum, 514 saddr, sport); 515 matches = 1; 516 } 517 } else if (score == badness && reuseport) { 518 matches++; 519 if (((u64)hash * matches) >> 32 == 0) 520 result = sk; 521 hash = next_pseudo_random32(hash); 522 } 523 } 524 /* 525 * if the nulls value we got at the end of this lookup is 526 * not the expected one, we must restart lookup. 527 * We probably met an item that was moved to another chain. 528 */ 529 if (get_nulls_value(node) != slot) 530 goto begin; 531 532 if (result) { 533 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 534 result = NULL; 535 else if (unlikely(compute_score(result, net, saddr, hnum, sport, 536 daddr, dport, dif) < badness)) { 537 sock_put(result); 538 goto begin; 539 } 540 } 541 rcu_read_unlock(); 542 return result; 543 } 544 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 545 546 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 547 __be16 sport, __be16 dport, 548 struct udp_table *udptable) 549 { 550 struct sock *sk; 551 const struct iphdr *iph = ip_hdr(skb); 552 553 if (unlikely(sk = skb_steal_sock(skb))) 554 return sk; 555 else 556 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, 557 iph->daddr, dport, inet_iif(skb), 558 udptable); 559 } 560 561 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 562 __be32 daddr, __be16 dport, int dif) 563 { 564 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); 565 } 566 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 567 568 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk, 569 __be16 loc_port, __be32 loc_addr, 570 __be16 rmt_port, __be32 rmt_addr, 571 int dif) 572 { 573 struct hlist_nulls_node *node; 574 struct sock *s = sk; 575 unsigned short hnum = ntohs(loc_port); 576 577 sk_nulls_for_each_from(s, node) { 578 struct inet_sock *inet = inet_sk(s); 579 580 if (!net_eq(sock_net(s), net) || 581 udp_sk(s)->udp_port_hash != hnum || 582 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 583 (inet->inet_dport != rmt_port && inet->inet_dport) || 584 (inet->inet_rcv_saddr && 585 inet->inet_rcv_saddr != loc_addr) || 586 ipv6_only_sock(s) || 587 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) 588 continue; 589 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) 590 continue; 591 goto found; 592 } 593 s = NULL; 594 found: 595 return s; 596 } 597 598 /* 599 * This routine is called by the ICMP module when it gets some 600 * sort of error condition. If err < 0 then the socket should 601 * be closed and the error returned to the user. If err > 0 602 * it's just the icmp type << 8 | icmp code. 603 * Header points to the ip header of the error packet. We move 604 * on past this. Then (as it used to claim before adjustment) 605 * header points to the first 8 bytes of the udp header. We need 606 * to find the appropriate port. 607 */ 608 609 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 610 { 611 struct inet_sock *inet; 612 const struct iphdr *iph = (const struct iphdr *)skb->data; 613 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 614 const int type = icmp_hdr(skb)->type; 615 const int code = icmp_hdr(skb)->code; 616 struct sock *sk; 617 int harderr; 618 int err; 619 struct net *net = dev_net(skb->dev); 620 621 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 622 iph->saddr, uh->source, skb->dev->ifindex, udptable); 623 if (sk == NULL) { 624 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 625 return; /* No socket for error */ 626 } 627 628 err = 0; 629 harderr = 0; 630 inet = inet_sk(sk); 631 632 switch (type) { 633 default: 634 case ICMP_TIME_EXCEEDED: 635 err = EHOSTUNREACH; 636 break; 637 case ICMP_SOURCE_QUENCH: 638 goto out; 639 case ICMP_PARAMETERPROB: 640 err = EPROTO; 641 harderr = 1; 642 break; 643 case ICMP_DEST_UNREACH: 644 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 645 ipv4_sk_update_pmtu(skb, sk, info); 646 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 647 err = EMSGSIZE; 648 harderr = 1; 649 break; 650 } 651 goto out; 652 } 653 err = EHOSTUNREACH; 654 if (code <= NR_ICMP_UNREACH) { 655 harderr = icmp_err_convert[code].fatal; 656 err = icmp_err_convert[code].errno; 657 } 658 break; 659 case ICMP_REDIRECT: 660 ipv4_sk_redirect(skb, sk); 661 break; 662 } 663 664 /* 665 * RFC1122: OK. Passes ICMP errors back to application, as per 666 * 4.1.3.3. 667 */ 668 if (!inet->recverr) { 669 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 670 goto out; 671 } else 672 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 673 674 sk->sk_err = err; 675 sk->sk_error_report(sk); 676 out: 677 sock_put(sk); 678 } 679 680 void udp_err(struct sk_buff *skb, u32 info) 681 { 682 __udp4_lib_err(skb, info, &udp_table); 683 } 684 685 /* 686 * Throw away all pending data and cancel the corking. Socket is locked. 687 */ 688 void udp_flush_pending_frames(struct sock *sk) 689 { 690 struct udp_sock *up = udp_sk(sk); 691 692 if (up->pending) { 693 up->len = 0; 694 up->pending = 0; 695 ip_flush_pending_frames(sk); 696 } 697 } 698 EXPORT_SYMBOL(udp_flush_pending_frames); 699 700 /** 701 * udp4_hwcsum - handle outgoing HW checksumming 702 * @skb: sk_buff containing the filled-in UDP header 703 * (checksum field must be zeroed out) 704 * @src: source IP address 705 * @dst: destination IP address 706 */ 707 static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 708 { 709 struct udphdr *uh = udp_hdr(skb); 710 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 711 int offset = skb_transport_offset(skb); 712 int len = skb->len - offset; 713 int hlen = len; 714 __wsum csum = 0; 715 716 if (!frags) { 717 /* 718 * Only one fragment on the socket. 719 */ 720 skb->csum_start = skb_transport_header(skb) - skb->head; 721 skb->csum_offset = offsetof(struct udphdr, check); 722 uh->check = ~csum_tcpudp_magic(src, dst, len, 723 IPPROTO_UDP, 0); 724 } else { 725 /* 726 * HW-checksum won't work as there are two or more 727 * fragments on the socket so that all csums of sk_buffs 728 * should be together 729 */ 730 do { 731 csum = csum_add(csum, frags->csum); 732 hlen -= frags->len; 733 } while ((frags = frags->next)); 734 735 csum = skb_checksum(skb, offset, hlen, csum); 736 skb->ip_summed = CHECKSUM_NONE; 737 738 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 739 if (uh->check == 0) 740 uh->check = CSUM_MANGLED_0; 741 } 742 } 743 744 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) 745 { 746 struct sock *sk = skb->sk; 747 struct inet_sock *inet = inet_sk(sk); 748 struct udphdr *uh; 749 int err = 0; 750 int is_udplite = IS_UDPLITE(sk); 751 int offset = skb_transport_offset(skb); 752 int len = skb->len - offset; 753 __wsum csum = 0; 754 755 /* 756 * Create a UDP header 757 */ 758 uh = udp_hdr(skb); 759 uh->source = inet->inet_sport; 760 uh->dest = fl4->fl4_dport; 761 uh->len = htons(len); 762 uh->check = 0; 763 764 if (is_udplite) /* UDP-Lite */ 765 csum = udplite_csum(skb); 766 767 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ 768 769 skb->ip_summed = CHECKSUM_NONE; 770 goto send; 771 772 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 773 774 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 775 goto send; 776 777 } else 778 csum = udp_csum(skb); 779 780 /* add protocol-dependent pseudo-header */ 781 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 782 sk->sk_protocol, csum); 783 if (uh->check == 0) 784 uh->check = CSUM_MANGLED_0; 785 786 send: 787 err = ip_send_skb(sock_net(sk), skb); 788 if (err) { 789 if (err == -ENOBUFS && !inet->recverr) { 790 UDP_INC_STATS_USER(sock_net(sk), 791 UDP_MIB_SNDBUFERRORS, is_udplite); 792 err = 0; 793 } 794 } else 795 UDP_INC_STATS_USER(sock_net(sk), 796 UDP_MIB_OUTDATAGRAMS, is_udplite); 797 return err; 798 } 799 800 /* 801 * Push out all pending data as one UDP datagram. Socket is locked. 802 */ 803 int udp_push_pending_frames(struct sock *sk) 804 { 805 struct udp_sock *up = udp_sk(sk); 806 struct inet_sock *inet = inet_sk(sk); 807 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 808 struct sk_buff *skb; 809 int err = 0; 810 811 skb = ip_finish_skb(sk, fl4); 812 if (!skb) 813 goto out; 814 815 err = udp_send_skb(skb, fl4); 816 817 out: 818 up->len = 0; 819 up->pending = 0; 820 return err; 821 } 822 EXPORT_SYMBOL(udp_push_pending_frames); 823 824 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 825 size_t len) 826 { 827 struct inet_sock *inet = inet_sk(sk); 828 struct udp_sock *up = udp_sk(sk); 829 struct flowi4 fl4_stack; 830 struct flowi4 *fl4; 831 int ulen = len; 832 struct ipcm_cookie ipc; 833 struct rtable *rt = NULL; 834 int free = 0; 835 int connected = 0; 836 __be32 daddr, faddr, saddr; 837 __be16 dport; 838 u8 tos; 839 int err, is_udplite = IS_UDPLITE(sk); 840 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 841 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 842 struct sk_buff *skb; 843 struct ip_options_data opt_copy; 844 845 if (len > 0xFFFF) 846 return -EMSGSIZE; 847 848 /* 849 * Check the flags. 850 */ 851 852 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 853 return -EOPNOTSUPP; 854 855 ipc.opt = NULL; 856 ipc.tx_flags = 0; 857 858 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 859 860 fl4 = &inet->cork.fl.u.ip4; 861 if (up->pending) { 862 /* 863 * There are pending frames. 864 * The socket lock must be held while it's corked. 865 */ 866 lock_sock(sk); 867 if (likely(up->pending)) { 868 if (unlikely(up->pending != AF_INET)) { 869 release_sock(sk); 870 return -EINVAL; 871 } 872 goto do_append_data; 873 } 874 release_sock(sk); 875 } 876 ulen += sizeof(struct udphdr); 877 878 /* 879 * Get and verify the address. 880 */ 881 if (msg->msg_name) { 882 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name; 883 if (msg->msg_namelen < sizeof(*usin)) 884 return -EINVAL; 885 if (usin->sin_family != AF_INET) { 886 if (usin->sin_family != AF_UNSPEC) 887 return -EAFNOSUPPORT; 888 } 889 890 daddr = usin->sin_addr.s_addr; 891 dport = usin->sin_port; 892 if (dport == 0) 893 return -EINVAL; 894 } else { 895 if (sk->sk_state != TCP_ESTABLISHED) 896 return -EDESTADDRREQ; 897 daddr = inet->inet_daddr; 898 dport = inet->inet_dport; 899 /* Open fast path for connected socket. 900 Route will not be used, if at least one option is set. 901 */ 902 connected = 1; 903 } 904 ipc.addr = inet->inet_saddr; 905 906 ipc.oif = sk->sk_bound_dev_if; 907 908 sock_tx_timestamp(sk, &ipc.tx_flags); 909 910 if (msg->msg_controllen) { 911 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 912 if (err) 913 return err; 914 if (ipc.opt) 915 free = 1; 916 connected = 0; 917 } 918 if (!ipc.opt) { 919 struct ip_options_rcu *inet_opt; 920 921 rcu_read_lock(); 922 inet_opt = rcu_dereference(inet->inet_opt); 923 if (inet_opt) { 924 memcpy(&opt_copy, inet_opt, 925 sizeof(*inet_opt) + inet_opt->opt.optlen); 926 ipc.opt = &opt_copy.opt; 927 } 928 rcu_read_unlock(); 929 } 930 931 saddr = ipc.addr; 932 ipc.addr = faddr = daddr; 933 934 if (ipc.opt && ipc.opt->opt.srr) { 935 if (!daddr) 936 return -EINVAL; 937 faddr = ipc.opt->opt.faddr; 938 connected = 0; 939 } 940 tos = RT_TOS(inet->tos); 941 if (sock_flag(sk, SOCK_LOCALROUTE) || 942 (msg->msg_flags & MSG_DONTROUTE) || 943 (ipc.opt && ipc.opt->opt.is_strictroute)) { 944 tos |= RTO_ONLINK; 945 connected = 0; 946 } 947 948 if (ipv4_is_multicast(daddr)) { 949 if (!ipc.oif) 950 ipc.oif = inet->mc_index; 951 if (!saddr) 952 saddr = inet->mc_addr; 953 connected = 0; 954 } else if (!ipc.oif) 955 ipc.oif = inet->uc_index; 956 957 if (connected) 958 rt = (struct rtable *)sk_dst_check(sk, 0); 959 960 if (rt == NULL) { 961 struct net *net = sock_net(sk); 962 963 fl4 = &fl4_stack; 964 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, 965 RT_SCOPE_UNIVERSE, sk->sk_protocol, 966 inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP, 967 faddr, saddr, dport, inet->inet_sport); 968 969 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 970 rt = ip_route_output_flow(net, fl4, sk); 971 if (IS_ERR(rt)) { 972 err = PTR_ERR(rt); 973 rt = NULL; 974 if (err == -ENETUNREACH) 975 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 976 goto out; 977 } 978 979 err = -EACCES; 980 if ((rt->rt_flags & RTCF_BROADCAST) && 981 !sock_flag(sk, SOCK_BROADCAST)) 982 goto out; 983 if (connected) 984 sk_dst_set(sk, dst_clone(&rt->dst)); 985 } 986 987 if (msg->msg_flags&MSG_CONFIRM) 988 goto do_confirm; 989 back_from_confirm: 990 991 saddr = fl4->saddr; 992 if (!ipc.addr) 993 daddr = ipc.addr = fl4->daddr; 994 995 /* Lockless fast path for the non-corking case. */ 996 if (!corkreq) { 997 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen, 998 sizeof(struct udphdr), &ipc, &rt, 999 msg->msg_flags); 1000 err = PTR_ERR(skb); 1001 if (!IS_ERR_OR_NULL(skb)) 1002 err = udp_send_skb(skb, fl4); 1003 goto out; 1004 } 1005 1006 lock_sock(sk); 1007 if (unlikely(up->pending)) { 1008 /* The socket is already corked while preparing it. */ 1009 /* ... which is an evident application bug. --ANK */ 1010 release_sock(sk); 1011 1012 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n")); 1013 err = -EINVAL; 1014 goto out; 1015 } 1016 /* 1017 * Now cork the socket to pend data. 1018 */ 1019 fl4 = &inet->cork.fl.u.ip4; 1020 fl4->daddr = daddr; 1021 fl4->saddr = saddr; 1022 fl4->fl4_dport = dport; 1023 fl4->fl4_sport = inet->inet_sport; 1024 up->pending = AF_INET; 1025 1026 do_append_data: 1027 up->len += ulen; 1028 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen, 1029 sizeof(struct udphdr), &ipc, &rt, 1030 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1031 if (err) 1032 udp_flush_pending_frames(sk); 1033 else if (!corkreq) 1034 err = udp_push_pending_frames(sk); 1035 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1036 up->pending = 0; 1037 release_sock(sk); 1038 1039 out: 1040 ip_rt_put(rt); 1041 if (free) 1042 kfree(ipc.opt); 1043 if (!err) 1044 return len; 1045 /* 1046 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1047 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1048 * we don't have a good statistic (IpOutDiscards but it can be too many 1049 * things). We could add another new stat but at least for now that 1050 * seems like overkill. 1051 */ 1052 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1053 UDP_INC_STATS_USER(sock_net(sk), 1054 UDP_MIB_SNDBUFERRORS, is_udplite); 1055 } 1056 return err; 1057 1058 do_confirm: 1059 dst_confirm(&rt->dst); 1060 if (!(msg->msg_flags&MSG_PROBE) || len) 1061 goto back_from_confirm; 1062 err = 0; 1063 goto out; 1064 } 1065 EXPORT_SYMBOL(udp_sendmsg); 1066 1067 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1068 size_t size, int flags) 1069 { 1070 struct inet_sock *inet = inet_sk(sk); 1071 struct udp_sock *up = udp_sk(sk); 1072 int ret; 1073 1074 if (!up->pending) { 1075 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1076 1077 /* Call udp_sendmsg to specify destination address which 1078 * sendpage interface can't pass. 1079 * This will succeed only when the socket is connected. 1080 */ 1081 ret = udp_sendmsg(NULL, sk, &msg, 0); 1082 if (ret < 0) 1083 return ret; 1084 } 1085 1086 lock_sock(sk); 1087 1088 if (unlikely(!up->pending)) { 1089 release_sock(sk); 1090 1091 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n")); 1092 return -EINVAL; 1093 } 1094 1095 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1096 page, offset, size, flags); 1097 if (ret == -EOPNOTSUPP) { 1098 release_sock(sk); 1099 return sock_no_sendpage(sk->sk_socket, page, offset, 1100 size, flags); 1101 } 1102 if (ret < 0) { 1103 udp_flush_pending_frames(sk); 1104 goto out; 1105 } 1106 1107 up->len += size; 1108 if (!(up->corkflag || (flags&MSG_MORE))) 1109 ret = udp_push_pending_frames(sk); 1110 if (!ret) 1111 ret = size; 1112 out: 1113 release_sock(sk); 1114 return ret; 1115 } 1116 1117 1118 /** 1119 * first_packet_length - return length of first packet in receive queue 1120 * @sk: socket 1121 * 1122 * Drops all bad checksum frames, until a valid one is found. 1123 * Returns the length of found skb, or 0 if none is found. 1124 */ 1125 static unsigned int first_packet_length(struct sock *sk) 1126 { 1127 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue; 1128 struct sk_buff *skb; 1129 unsigned int res; 1130 1131 __skb_queue_head_init(&list_kill); 1132 1133 spin_lock_bh(&rcvq->lock); 1134 while ((skb = skb_peek(rcvq)) != NULL && 1135 udp_lib_checksum_complete(skb)) { 1136 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, 1137 IS_UDPLITE(sk)); 1138 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1139 IS_UDPLITE(sk)); 1140 atomic_inc(&sk->sk_drops); 1141 __skb_unlink(skb, rcvq); 1142 __skb_queue_tail(&list_kill, skb); 1143 } 1144 res = skb ? skb->len : 0; 1145 spin_unlock_bh(&rcvq->lock); 1146 1147 if (!skb_queue_empty(&list_kill)) { 1148 bool slow = lock_sock_fast(sk); 1149 1150 __skb_queue_purge(&list_kill); 1151 sk_mem_reclaim_partial(sk); 1152 unlock_sock_fast(sk, slow); 1153 } 1154 return res; 1155 } 1156 1157 /* 1158 * IOCTL requests applicable to the UDP protocol 1159 */ 1160 1161 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1162 { 1163 switch (cmd) { 1164 case SIOCOUTQ: 1165 { 1166 int amount = sk_wmem_alloc_get(sk); 1167 1168 return put_user(amount, (int __user *)arg); 1169 } 1170 1171 case SIOCINQ: 1172 { 1173 unsigned int amount = first_packet_length(sk); 1174 1175 if (amount) 1176 /* 1177 * We will only return the amount 1178 * of this packet since that is all 1179 * that will be read. 1180 */ 1181 amount -= sizeof(struct udphdr); 1182 1183 return put_user(amount, (int __user *)arg); 1184 } 1185 1186 default: 1187 return -ENOIOCTLCMD; 1188 } 1189 1190 return 0; 1191 } 1192 EXPORT_SYMBOL(udp_ioctl); 1193 1194 /* 1195 * This should be easy, if there is something there we 1196 * return it, otherwise we block. 1197 */ 1198 1199 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1200 size_t len, int noblock, int flags, int *addr_len) 1201 { 1202 struct inet_sock *inet = inet_sk(sk); 1203 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 1204 struct sk_buff *skb; 1205 unsigned int ulen, copied; 1206 int peeked, off = 0; 1207 int err; 1208 int is_udplite = IS_UDPLITE(sk); 1209 bool slow; 1210 1211 /* 1212 * Check any passed addresses 1213 */ 1214 if (addr_len) 1215 *addr_len = sizeof(*sin); 1216 1217 if (flags & MSG_ERRQUEUE) 1218 return ip_recv_error(sk, msg, len); 1219 1220 try_again: 1221 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), 1222 &peeked, &off, &err); 1223 if (!skb) 1224 goto out; 1225 1226 ulen = skb->len - sizeof(struct udphdr); 1227 copied = len; 1228 if (copied > ulen) 1229 copied = ulen; 1230 else if (copied < ulen) 1231 msg->msg_flags |= MSG_TRUNC; 1232 1233 /* 1234 * If checksum is needed at all, try to do it while copying the 1235 * data. If the data is truncated, or if we only want a partial 1236 * coverage checksum (UDP-Lite), do it before the copy. 1237 */ 1238 1239 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { 1240 if (udp_lib_checksum_complete(skb)) 1241 goto csum_copy_err; 1242 } 1243 1244 if (skb_csum_unnecessary(skb)) 1245 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), 1246 msg->msg_iov, copied); 1247 else { 1248 err = skb_copy_and_csum_datagram_iovec(skb, 1249 sizeof(struct udphdr), 1250 msg->msg_iov); 1251 1252 if (err == -EINVAL) 1253 goto csum_copy_err; 1254 } 1255 1256 if (unlikely(err)) { 1257 trace_kfree_skb(skb, udp_recvmsg); 1258 if (!peeked) { 1259 atomic_inc(&sk->sk_drops); 1260 UDP_INC_STATS_USER(sock_net(sk), 1261 UDP_MIB_INERRORS, is_udplite); 1262 } 1263 goto out_free; 1264 } 1265 1266 if (!peeked) 1267 UDP_INC_STATS_USER(sock_net(sk), 1268 UDP_MIB_INDATAGRAMS, is_udplite); 1269 1270 sock_recv_ts_and_drops(msg, sk, skb); 1271 1272 /* Copy the address. */ 1273 if (sin) { 1274 sin->sin_family = AF_INET; 1275 sin->sin_port = udp_hdr(skb)->source; 1276 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1277 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1278 } 1279 if (inet->cmsg_flags) 1280 ip_cmsg_recv(msg, skb); 1281 1282 err = copied; 1283 if (flags & MSG_TRUNC) 1284 err = ulen; 1285 1286 out_free: 1287 skb_free_datagram_locked(sk, skb); 1288 out: 1289 return err; 1290 1291 csum_copy_err: 1292 slow = lock_sock_fast(sk); 1293 if (!skb_kill_datagram(sk, skb, flags)) { 1294 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1295 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1296 } 1297 unlock_sock_fast(sk, slow); 1298 1299 if (noblock) 1300 return -EAGAIN; 1301 1302 /* starting over for a new packet */ 1303 msg->msg_flags &= ~MSG_TRUNC; 1304 goto try_again; 1305 } 1306 1307 1308 int udp_disconnect(struct sock *sk, int flags) 1309 { 1310 struct inet_sock *inet = inet_sk(sk); 1311 /* 1312 * 1003.1g - break association. 1313 */ 1314 1315 sk->sk_state = TCP_CLOSE; 1316 inet->inet_daddr = 0; 1317 inet->inet_dport = 0; 1318 sock_rps_reset_rxhash(sk); 1319 sk->sk_bound_dev_if = 0; 1320 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1321 inet_reset_saddr(sk); 1322 1323 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1324 sk->sk_prot->unhash(sk); 1325 inet->inet_sport = 0; 1326 } 1327 sk_dst_reset(sk); 1328 return 0; 1329 } 1330 EXPORT_SYMBOL(udp_disconnect); 1331 1332 void udp_lib_unhash(struct sock *sk) 1333 { 1334 if (sk_hashed(sk)) { 1335 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1336 struct udp_hslot *hslot, *hslot2; 1337 1338 hslot = udp_hashslot(udptable, sock_net(sk), 1339 udp_sk(sk)->udp_port_hash); 1340 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1341 1342 spin_lock_bh(&hslot->lock); 1343 if (sk_nulls_del_node_init_rcu(sk)) { 1344 hslot->count--; 1345 inet_sk(sk)->inet_num = 0; 1346 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1347 1348 spin_lock(&hslot2->lock); 1349 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1350 hslot2->count--; 1351 spin_unlock(&hslot2->lock); 1352 } 1353 spin_unlock_bh(&hslot->lock); 1354 } 1355 } 1356 EXPORT_SYMBOL(udp_lib_unhash); 1357 1358 /* 1359 * inet_rcv_saddr was changed, we must rehash secondary hash 1360 */ 1361 void udp_lib_rehash(struct sock *sk, u16 newhash) 1362 { 1363 if (sk_hashed(sk)) { 1364 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1365 struct udp_hslot *hslot, *hslot2, *nhslot2; 1366 1367 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1368 nhslot2 = udp_hashslot2(udptable, newhash); 1369 udp_sk(sk)->udp_portaddr_hash = newhash; 1370 if (hslot2 != nhslot2) { 1371 hslot = udp_hashslot(udptable, sock_net(sk), 1372 udp_sk(sk)->udp_port_hash); 1373 /* we must lock primary chain too */ 1374 spin_lock_bh(&hslot->lock); 1375 1376 spin_lock(&hslot2->lock); 1377 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1378 hslot2->count--; 1379 spin_unlock(&hslot2->lock); 1380 1381 spin_lock(&nhslot2->lock); 1382 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1383 &nhslot2->head); 1384 nhslot2->count++; 1385 spin_unlock(&nhslot2->lock); 1386 1387 spin_unlock_bh(&hslot->lock); 1388 } 1389 } 1390 } 1391 EXPORT_SYMBOL(udp_lib_rehash); 1392 1393 static void udp_v4_rehash(struct sock *sk) 1394 { 1395 u16 new_hash = udp4_portaddr_hash(sock_net(sk), 1396 inet_sk(sk)->inet_rcv_saddr, 1397 inet_sk(sk)->inet_num); 1398 udp_lib_rehash(sk, new_hash); 1399 } 1400 1401 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1402 { 1403 int rc; 1404 1405 if (inet_sk(sk)->inet_daddr) 1406 sock_rps_save_rxhash(sk, skb); 1407 1408 rc = sock_queue_rcv_skb(sk, skb); 1409 if (rc < 0) { 1410 int is_udplite = IS_UDPLITE(sk); 1411 1412 /* Note that an ENOMEM error is charged twice */ 1413 if (rc == -ENOMEM) 1414 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1415 is_udplite); 1416 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1417 kfree_skb(skb); 1418 trace_udp_fail_queue_rcv_skb(rc, sk); 1419 return -1; 1420 } 1421 1422 return 0; 1423 1424 } 1425 1426 static struct static_key udp_encap_needed __read_mostly; 1427 void udp_encap_enable(void) 1428 { 1429 if (!static_key_enabled(&udp_encap_needed)) 1430 static_key_slow_inc(&udp_encap_needed); 1431 } 1432 EXPORT_SYMBOL(udp_encap_enable); 1433 1434 /* returns: 1435 * -1: error 1436 * 0: success 1437 * >0: "udp encap" protocol resubmission 1438 * 1439 * Note that in the success and error cases, the skb is assumed to 1440 * have either been requeued or freed. 1441 */ 1442 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1443 { 1444 struct udp_sock *up = udp_sk(sk); 1445 int rc; 1446 int is_udplite = IS_UDPLITE(sk); 1447 1448 /* 1449 * Charge it to the socket, dropping if the queue is full. 1450 */ 1451 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1452 goto drop; 1453 nf_reset(skb); 1454 1455 if (static_key_false(&udp_encap_needed) && up->encap_type) { 1456 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 1457 1458 /* 1459 * This is an encapsulation socket so pass the skb to 1460 * the socket's udp_encap_rcv() hook. Otherwise, just 1461 * fall through and pass this up the UDP socket. 1462 * up->encap_rcv() returns the following value: 1463 * =0 if skb was successfully passed to the encap 1464 * handler or was discarded by it. 1465 * >0 if skb should be passed on to UDP. 1466 * <0 if skb should be resubmitted as proto -N 1467 */ 1468 1469 /* if we're overly short, let UDP handle it */ 1470 encap_rcv = ACCESS_ONCE(up->encap_rcv); 1471 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) { 1472 int ret; 1473 1474 ret = encap_rcv(sk, skb); 1475 if (ret <= 0) { 1476 UDP_INC_STATS_BH(sock_net(sk), 1477 UDP_MIB_INDATAGRAMS, 1478 is_udplite); 1479 return -ret; 1480 } 1481 } 1482 1483 /* FALLTHROUGH -- it's a UDP Packet */ 1484 } 1485 1486 /* 1487 * UDP-Lite specific tests, ignored on UDP sockets 1488 */ 1489 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1490 1491 /* 1492 * MIB statistics other than incrementing the error count are 1493 * disabled for the following two types of errors: these depend 1494 * on the application settings, not on the functioning of the 1495 * protocol stack as such. 1496 * 1497 * RFC 3828 here recommends (sec 3.3): "There should also be a 1498 * way ... to ... at least let the receiving application block 1499 * delivery of packets with coverage values less than a value 1500 * provided by the application." 1501 */ 1502 if (up->pcrlen == 0) { /* full coverage was set */ 1503 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n", 1504 UDP_SKB_CB(skb)->cscov, skb->len); 1505 goto drop; 1506 } 1507 /* The next case involves violating the min. coverage requested 1508 * by the receiver. This is subtle: if receiver wants x and x is 1509 * greater than the buffersize/MTU then receiver will complain 1510 * that it wants x while sender emits packets of smaller size y. 1511 * Therefore the above ...()->partial_cov statement is essential. 1512 */ 1513 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1514 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n", 1515 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1516 goto drop; 1517 } 1518 } 1519 1520 if (rcu_access_pointer(sk->sk_filter) && 1521 udp_lib_checksum_complete(skb)) 1522 goto csum_error; 1523 1524 1525 if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) 1526 goto drop; 1527 1528 rc = 0; 1529 1530 ipv4_pktinfo_prepare(skb); 1531 bh_lock_sock(sk); 1532 if (!sock_owned_by_user(sk)) 1533 rc = __udp_queue_rcv_skb(sk, skb); 1534 else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) { 1535 bh_unlock_sock(sk); 1536 goto drop; 1537 } 1538 bh_unlock_sock(sk); 1539 1540 return rc; 1541 1542 csum_error: 1543 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1544 drop: 1545 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1546 atomic_inc(&sk->sk_drops); 1547 kfree_skb(skb); 1548 return -1; 1549 } 1550 1551 1552 static void flush_stack(struct sock **stack, unsigned int count, 1553 struct sk_buff *skb, unsigned int final) 1554 { 1555 unsigned int i; 1556 struct sk_buff *skb1 = NULL; 1557 struct sock *sk; 1558 1559 for (i = 0; i < count; i++) { 1560 sk = stack[i]; 1561 if (likely(skb1 == NULL)) 1562 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); 1563 1564 if (!skb1) { 1565 atomic_inc(&sk->sk_drops); 1566 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1567 IS_UDPLITE(sk)); 1568 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1569 IS_UDPLITE(sk)); 1570 } 1571 1572 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0) 1573 skb1 = NULL; 1574 } 1575 if (unlikely(skb1)) 1576 kfree_skb(skb1); 1577 } 1578 1579 /* 1580 * Multicasts and broadcasts go to each listener. 1581 * 1582 * Note: called only from the BH handler context. 1583 */ 1584 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 1585 struct udphdr *uh, 1586 __be32 saddr, __be32 daddr, 1587 struct udp_table *udptable) 1588 { 1589 struct sock *sk, *stack[256 / sizeof(struct sock *)]; 1590 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest)); 1591 int dif; 1592 unsigned int i, count = 0; 1593 1594 spin_lock(&hslot->lock); 1595 sk = sk_nulls_head(&hslot->head); 1596 dif = skb->dev->ifindex; 1597 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); 1598 while (sk) { 1599 stack[count++] = sk; 1600 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest, 1601 daddr, uh->source, saddr, dif); 1602 if (unlikely(count == ARRAY_SIZE(stack))) { 1603 if (!sk) 1604 break; 1605 flush_stack(stack, count, skb, ~0); 1606 count = 0; 1607 } 1608 } 1609 /* 1610 * before releasing chain lock, we must take a reference on sockets 1611 */ 1612 for (i = 0; i < count; i++) 1613 sock_hold(stack[i]); 1614 1615 spin_unlock(&hslot->lock); 1616 1617 /* 1618 * do the slow work with no lock held 1619 */ 1620 if (count) { 1621 flush_stack(stack, count, skb, count - 1); 1622 1623 for (i = 0; i < count; i++) 1624 sock_put(stack[i]); 1625 } else { 1626 kfree_skb(skb); 1627 } 1628 return 0; 1629 } 1630 1631 /* Initialize UDP checksum. If exited with zero value (success), 1632 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1633 * Otherwise, csum completion requires chacksumming packet body, 1634 * including udp header and folding it to skb->csum. 1635 */ 1636 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 1637 int proto) 1638 { 1639 const struct iphdr *iph; 1640 int err; 1641 1642 UDP_SKB_CB(skb)->partial_cov = 0; 1643 UDP_SKB_CB(skb)->cscov = skb->len; 1644 1645 if (proto == IPPROTO_UDPLITE) { 1646 err = udplite_checksum_init(skb, uh); 1647 if (err) 1648 return err; 1649 } 1650 1651 iph = ip_hdr(skb); 1652 if (uh->check == 0) { 1653 skb->ip_summed = CHECKSUM_UNNECESSARY; 1654 } else if (skb->ip_summed == CHECKSUM_COMPLETE) { 1655 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 1656 proto, skb->csum)) 1657 skb->ip_summed = CHECKSUM_UNNECESSARY; 1658 } 1659 if (!skb_csum_unnecessary(skb)) 1660 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, 1661 skb->len, proto, 0); 1662 /* Probably, we should checksum udp header (it should be in cache 1663 * in any case) and data in tiny packets (< rx copybreak). 1664 */ 1665 1666 return 0; 1667 } 1668 1669 /* 1670 * All we need to do is get the socket, and then do a checksum. 1671 */ 1672 1673 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 1674 int proto) 1675 { 1676 struct sock *sk; 1677 struct udphdr *uh; 1678 unsigned short ulen; 1679 struct rtable *rt = skb_rtable(skb); 1680 __be32 saddr, daddr; 1681 struct net *net = dev_net(skb->dev); 1682 1683 /* 1684 * Validate the packet. 1685 */ 1686 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1687 goto drop; /* No space for header. */ 1688 1689 uh = udp_hdr(skb); 1690 ulen = ntohs(uh->len); 1691 saddr = ip_hdr(skb)->saddr; 1692 daddr = ip_hdr(skb)->daddr; 1693 1694 if (ulen > skb->len) 1695 goto short_packet; 1696 1697 if (proto == IPPROTO_UDP) { 1698 /* UDP validates ulen. */ 1699 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1700 goto short_packet; 1701 uh = udp_hdr(skb); 1702 } 1703 1704 if (udp4_csum_init(skb, uh, proto)) 1705 goto csum_error; 1706 1707 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1708 return __udp4_lib_mcast_deliver(net, skb, uh, 1709 saddr, daddr, udptable); 1710 1711 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 1712 1713 if (sk != NULL) { 1714 int ret; 1715 1716 sk_mark_napi_id(sk, skb); 1717 ret = udp_queue_rcv_skb(sk, skb); 1718 sock_put(sk); 1719 1720 /* a return value > 0 means to resubmit the input, but 1721 * it wants the return to be -protocol, or 0 1722 */ 1723 if (ret > 0) 1724 return -ret; 1725 return 0; 1726 } 1727 1728 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1729 goto drop; 1730 nf_reset(skb); 1731 1732 /* No socket. Drop packet silently, if checksum is wrong */ 1733 if (udp_lib_checksum_complete(skb)) 1734 goto csum_error; 1735 1736 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 1737 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1738 1739 /* 1740 * Hmm. We got an UDP packet to a port to which we 1741 * don't wanna listen. Ignore it. 1742 */ 1743 kfree_skb(skb); 1744 return 0; 1745 1746 short_packet: 1747 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 1748 proto == IPPROTO_UDPLITE ? "Lite" : "", 1749 &saddr, ntohs(uh->source), 1750 ulen, skb->len, 1751 &daddr, ntohs(uh->dest)); 1752 goto drop; 1753 1754 csum_error: 1755 /* 1756 * RFC1122: OK. Discards the bad packet silently (as far as 1757 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1758 */ 1759 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 1760 proto == IPPROTO_UDPLITE ? "Lite" : "", 1761 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 1762 ulen); 1763 UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 1764 drop: 1765 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1766 kfree_skb(skb); 1767 return 0; 1768 } 1769 1770 int udp_rcv(struct sk_buff *skb) 1771 { 1772 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 1773 } 1774 1775 void udp_destroy_sock(struct sock *sk) 1776 { 1777 struct udp_sock *up = udp_sk(sk); 1778 bool slow = lock_sock_fast(sk); 1779 udp_flush_pending_frames(sk); 1780 unlock_sock_fast(sk, slow); 1781 if (static_key_false(&udp_encap_needed) && up->encap_type) { 1782 void (*encap_destroy)(struct sock *sk); 1783 encap_destroy = ACCESS_ONCE(up->encap_destroy); 1784 if (encap_destroy) 1785 encap_destroy(sk); 1786 } 1787 } 1788 1789 /* 1790 * Socket option code for UDP 1791 */ 1792 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 1793 char __user *optval, unsigned int optlen, 1794 int (*push_pending_frames)(struct sock *)) 1795 { 1796 struct udp_sock *up = udp_sk(sk); 1797 int val; 1798 int err = 0; 1799 int is_udplite = IS_UDPLITE(sk); 1800 1801 if (optlen < sizeof(int)) 1802 return -EINVAL; 1803 1804 if (get_user(val, (int __user *)optval)) 1805 return -EFAULT; 1806 1807 switch (optname) { 1808 case UDP_CORK: 1809 if (val != 0) { 1810 up->corkflag = 1; 1811 } else { 1812 up->corkflag = 0; 1813 lock_sock(sk); 1814 (*push_pending_frames)(sk); 1815 release_sock(sk); 1816 } 1817 break; 1818 1819 case UDP_ENCAP: 1820 switch (val) { 1821 case 0: 1822 case UDP_ENCAP_ESPINUDP: 1823 case UDP_ENCAP_ESPINUDP_NON_IKE: 1824 up->encap_rcv = xfrm4_udp_encap_rcv; 1825 /* FALLTHROUGH */ 1826 case UDP_ENCAP_L2TPINUDP: 1827 up->encap_type = val; 1828 udp_encap_enable(); 1829 break; 1830 default: 1831 err = -ENOPROTOOPT; 1832 break; 1833 } 1834 break; 1835 1836 /* 1837 * UDP-Lite's partial checksum coverage (RFC 3828). 1838 */ 1839 /* The sender sets actual checksum coverage length via this option. 1840 * The case coverage > packet length is handled by send module. */ 1841 case UDPLITE_SEND_CSCOV: 1842 if (!is_udplite) /* Disable the option on UDP sockets */ 1843 return -ENOPROTOOPT; 1844 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 1845 val = 8; 1846 else if (val > USHRT_MAX) 1847 val = USHRT_MAX; 1848 up->pcslen = val; 1849 up->pcflag |= UDPLITE_SEND_CC; 1850 break; 1851 1852 /* The receiver specifies a minimum checksum coverage value. To make 1853 * sense, this should be set to at least 8 (as done below). If zero is 1854 * used, this again means full checksum coverage. */ 1855 case UDPLITE_RECV_CSCOV: 1856 if (!is_udplite) /* Disable the option on UDP sockets */ 1857 return -ENOPROTOOPT; 1858 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 1859 val = 8; 1860 else if (val > USHRT_MAX) 1861 val = USHRT_MAX; 1862 up->pcrlen = val; 1863 up->pcflag |= UDPLITE_RECV_CC; 1864 break; 1865 1866 default: 1867 err = -ENOPROTOOPT; 1868 break; 1869 } 1870 1871 return err; 1872 } 1873 EXPORT_SYMBOL(udp_lib_setsockopt); 1874 1875 int udp_setsockopt(struct sock *sk, int level, int optname, 1876 char __user *optval, unsigned int optlen) 1877 { 1878 if (level == SOL_UDP || level == SOL_UDPLITE) 1879 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1880 udp_push_pending_frames); 1881 return ip_setsockopt(sk, level, optname, optval, optlen); 1882 } 1883 1884 #ifdef CONFIG_COMPAT 1885 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 1886 char __user *optval, unsigned int optlen) 1887 { 1888 if (level == SOL_UDP || level == SOL_UDPLITE) 1889 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1890 udp_push_pending_frames); 1891 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 1892 } 1893 #endif 1894 1895 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 1896 char __user *optval, int __user *optlen) 1897 { 1898 struct udp_sock *up = udp_sk(sk); 1899 int val, len; 1900 1901 if (get_user(len, optlen)) 1902 return -EFAULT; 1903 1904 len = min_t(unsigned int, len, sizeof(int)); 1905 1906 if (len < 0) 1907 return -EINVAL; 1908 1909 switch (optname) { 1910 case UDP_CORK: 1911 val = up->corkflag; 1912 break; 1913 1914 case UDP_ENCAP: 1915 val = up->encap_type; 1916 break; 1917 1918 /* The following two cannot be changed on UDP sockets, the return is 1919 * always 0 (which corresponds to the full checksum coverage of UDP). */ 1920 case UDPLITE_SEND_CSCOV: 1921 val = up->pcslen; 1922 break; 1923 1924 case UDPLITE_RECV_CSCOV: 1925 val = up->pcrlen; 1926 break; 1927 1928 default: 1929 return -ENOPROTOOPT; 1930 } 1931 1932 if (put_user(len, optlen)) 1933 return -EFAULT; 1934 if (copy_to_user(optval, &val, len)) 1935 return -EFAULT; 1936 return 0; 1937 } 1938 EXPORT_SYMBOL(udp_lib_getsockopt); 1939 1940 int udp_getsockopt(struct sock *sk, int level, int optname, 1941 char __user *optval, int __user *optlen) 1942 { 1943 if (level == SOL_UDP || level == SOL_UDPLITE) 1944 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1945 return ip_getsockopt(sk, level, optname, optval, optlen); 1946 } 1947 1948 #ifdef CONFIG_COMPAT 1949 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 1950 char __user *optval, int __user *optlen) 1951 { 1952 if (level == SOL_UDP || level == SOL_UDPLITE) 1953 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1954 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 1955 } 1956 #endif 1957 /** 1958 * udp_poll - wait for a UDP event. 1959 * @file - file struct 1960 * @sock - socket 1961 * @wait - poll table 1962 * 1963 * This is same as datagram poll, except for the special case of 1964 * blocking sockets. If application is using a blocking fd 1965 * and a packet with checksum error is in the queue; 1966 * then it could get return from select indicating data available 1967 * but then block when reading it. Add special case code 1968 * to work around these arguably broken applications. 1969 */ 1970 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 1971 { 1972 unsigned int mask = datagram_poll(file, sock, wait); 1973 struct sock *sk = sock->sk; 1974 1975 sock_rps_record_flow(sk); 1976 1977 /* Check for false positives due to checksum errors */ 1978 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 1979 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk)) 1980 mask &= ~(POLLIN | POLLRDNORM); 1981 1982 return mask; 1983 1984 } 1985 EXPORT_SYMBOL(udp_poll); 1986 1987 struct proto udp_prot = { 1988 .name = "UDP", 1989 .owner = THIS_MODULE, 1990 .close = udp_lib_close, 1991 .connect = ip4_datagram_connect, 1992 .disconnect = udp_disconnect, 1993 .ioctl = udp_ioctl, 1994 .destroy = udp_destroy_sock, 1995 .setsockopt = udp_setsockopt, 1996 .getsockopt = udp_getsockopt, 1997 .sendmsg = udp_sendmsg, 1998 .recvmsg = udp_recvmsg, 1999 .sendpage = udp_sendpage, 2000 .backlog_rcv = __udp_queue_rcv_skb, 2001 .release_cb = ip4_datagram_release_cb, 2002 .hash = udp_lib_hash, 2003 .unhash = udp_lib_unhash, 2004 .rehash = udp_v4_rehash, 2005 .get_port = udp_v4_get_port, 2006 .memory_allocated = &udp_memory_allocated, 2007 .sysctl_mem = sysctl_udp_mem, 2008 .sysctl_wmem = &sysctl_udp_wmem_min, 2009 .sysctl_rmem = &sysctl_udp_rmem_min, 2010 .obj_size = sizeof(struct udp_sock), 2011 .slab_flags = SLAB_DESTROY_BY_RCU, 2012 .h.udp_table = &udp_table, 2013 #ifdef CONFIG_COMPAT 2014 .compat_setsockopt = compat_udp_setsockopt, 2015 .compat_getsockopt = compat_udp_getsockopt, 2016 #endif 2017 .clear_sk = sk_prot_clear_portaddr_nulls, 2018 }; 2019 EXPORT_SYMBOL(udp_prot); 2020 2021 /* ------------------------------------------------------------------------ */ 2022 #ifdef CONFIG_PROC_FS 2023 2024 static struct sock *udp_get_first(struct seq_file *seq, int start) 2025 { 2026 struct sock *sk; 2027 struct udp_iter_state *state = seq->private; 2028 struct net *net = seq_file_net(seq); 2029 2030 for (state->bucket = start; state->bucket <= state->udp_table->mask; 2031 ++state->bucket) { 2032 struct hlist_nulls_node *node; 2033 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; 2034 2035 if (hlist_nulls_empty(&hslot->head)) 2036 continue; 2037 2038 spin_lock_bh(&hslot->lock); 2039 sk_nulls_for_each(sk, node, &hslot->head) { 2040 if (!net_eq(sock_net(sk), net)) 2041 continue; 2042 if (sk->sk_family == state->family) 2043 goto found; 2044 } 2045 spin_unlock_bh(&hslot->lock); 2046 } 2047 sk = NULL; 2048 found: 2049 return sk; 2050 } 2051 2052 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2053 { 2054 struct udp_iter_state *state = seq->private; 2055 struct net *net = seq_file_net(seq); 2056 2057 do { 2058 sk = sk_nulls_next(sk); 2059 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); 2060 2061 if (!sk) { 2062 if (state->bucket <= state->udp_table->mask) 2063 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2064 return udp_get_first(seq, state->bucket + 1); 2065 } 2066 return sk; 2067 } 2068 2069 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2070 { 2071 struct sock *sk = udp_get_first(seq, 0); 2072 2073 if (sk) 2074 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2075 --pos; 2076 return pos ? NULL : sk; 2077 } 2078 2079 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2080 { 2081 struct udp_iter_state *state = seq->private; 2082 state->bucket = MAX_UDP_PORTS; 2083 2084 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2085 } 2086 2087 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2088 { 2089 struct sock *sk; 2090 2091 if (v == SEQ_START_TOKEN) 2092 sk = udp_get_idx(seq, 0); 2093 else 2094 sk = udp_get_next(seq, v); 2095 2096 ++*pos; 2097 return sk; 2098 } 2099 2100 static void udp_seq_stop(struct seq_file *seq, void *v) 2101 { 2102 struct udp_iter_state *state = seq->private; 2103 2104 if (state->bucket <= state->udp_table->mask) 2105 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2106 } 2107 2108 int udp_seq_open(struct inode *inode, struct file *file) 2109 { 2110 struct udp_seq_afinfo *afinfo = PDE_DATA(inode); 2111 struct udp_iter_state *s; 2112 int err; 2113 2114 err = seq_open_net(inode, file, &afinfo->seq_ops, 2115 sizeof(struct udp_iter_state)); 2116 if (err < 0) 2117 return err; 2118 2119 s = ((struct seq_file *)file->private_data)->private; 2120 s->family = afinfo->family; 2121 s->udp_table = afinfo->udp_table; 2122 return err; 2123 } 2124 EXPORT_SYMBOL(udp_seq_open); 2125 2126 /* ------------------------------------------------------------------------ */ 2127 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) 2128 { 2129 struct proc_dir_entry *p; 2130 int rc = 0; 2131 2132 afinfo->seq_ops.start = udp_seq_start; 2133 afinfo->seq_ops.next = udp_seq_next; 2134 afinfo->seq_ops.stop = udp_seq_stop; 2135 2136 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 2137 afinfo->seq_fops, afinfo); 2138 if (!p) 2139 rc = -ENOMEM; 2140 return rc; 2141 } 2142 EXPORT_SYMBOL(udp_proc_register); 2143 2144 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 2145 { 2146 remove_proc_entry(afinfo->name, net->proc_net); 2147 } 2148 EXPORT_SYMBOL(udp_proc_unregister); 2149 2150 /* ------------------------------------------------------------------------ */ 2151 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2152 int bucket, int *len) 2153 { 2154 struct inet_sock *inet = inet_sk(sp); 2155 __be32 dest = inet->inet_daddr; 2156 __be32 src = inet->inet_rcv_saddr; 2157 __u16 destp = ntohs(inet->inet_dport); 2158 __u16 srcp = ntohs(inet->inet_sport); 2159 2160 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2161 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n", 2162 bucket, src, srcp, dest, destp, sp->sk_state, 2163 sk_wmem_alloc_get(sp), 2164 sk_rmem_alloc_get(sp), 2165 0, 0L, 0, 2166 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2167 0, sock_i_ino(sp), 2168 atomic_read(&sp->sk_refcnt), sp, 2169 atomic_read(&sp->sk_drops), len); 2170 } 2171 2172 int udp4_seq_show(struct seq_file *seq, void *v) 2173 { 2174 if (v == SEQ_START_TOKEN) 2175 seq_printf(seq, "%-127s\n", 2176 " sl local_address rem_address st tx_queue " 2177 "rx_queue tr tm->when retrnsmt uid timeout " 2178 "inode ref pointer drops"); 2179 else { 2180 struct udp_iter_state *state = seq->private; 2181 int len; 2182 2183 udp4_format_sock(v, seq, state->bucket, &len); 2184 seq_printf(seq, "%*s\n", 127 - len, ""); 2185 } 2186 return 0; 2187 } 2188 2189 static const struct file_operations udp_afinfo_seq_fops = { 2190 .owner = THIS_MODULE, 2191 .open = udp_seq_open, 2192 .read = seq_read, 2193 .llseek = seq_lseek, 2194 .release = seq_release_net 2195 }; 2196 2197 /* ------------------------------------------------------------------------ */ 2198 static struct udp_seq_afinfo udp4_seq_afinfo = { 2199 .name = "udp", 2200 .family = AF_INET, 2201 .udp_table = &udp_table, 2202 .seq_fops = &udp_afinfo_seq_fops, 2203 .seq_ops = { 2204 .show = udp4_seq_show, 2205 }, 2206 }; 2207 2208 static int __net_init udp4_proc_init_net(struct net *net) 2209 { 2210 return udp_proc_register(net, &udp4_seq_afinfo); 2211 } 2212 2213 static void __net_exit udp4_proc_exit_net(struct net *net) 2214 { 2215 udp_proc_unregister(net, &udp4_seq_afinfo); 2216 } 2217 2218 static struct pernet_operations udp4_net_ops = { 2219 .init = udp4_proc_init_net, 2220 .exit = udp4_proc_exit_net, 2221 }; 2222 2223 int __init udp4_proc_init(void) 2224 { 2225 return register_pernet_subsys(&udp4_net_ops); 2226 } 2227 2228 void udp4_proc_exit(void) 2229 { 2230 unregister_pernet_subsys(&udp4_net_ops); 2231 } 2232 #endif /* CONFIG_PROC_FS */ 2233 2234 static __initdata unsigned long uhash_entries; 2235 static int __init set_uhash_entries(char *str) 2236 { 2237 ssize_t ret; 2238 2239 if (!str) 2240 return 0; 2241 2242 ret = kstrtoul(str, 0, &uhash_entries); 2243 if (ret) 2244 return 0; 2245 2246 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2247 uhash_entries = UDP_HTABLE_SIZE_MIN; 2248 return 1; 2249 } 2250 __setup("uhash_entries=", set_uhash_entries); 2251 2252 void __init udp_table_init(struct udp_table *table, const char *name) 2253 { 2254 unsigned int i; 2255 2256 table->hash = alloc_large_system_hash(name, 2257 2 * sizeof(struct udp_hslot), 2258 uhash_entries, 2259 21, /* one slot per 2 MB */ 2260 0, 2261 &table->log, 2262 &table->mask, 2263 UDP_HTABLE_SIZE_MIN, 2264 64 * 1024); 2265 2266 table->hash2 = table->hash + (table->mask + 1); 2267 for (i = 0; i <= table->mask; i++) { 2268 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); 2269 table->hash[i].count = 0; 2270 spin_lock_init(&table->hash[i].lock); 2271 } 2272 for (i = 0; i <= table->mask; i++) { 2273 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); 2274 table->hash2[i].count = 0; 2275 spin_lock_init(&table->hash2[i].lock); 2276 } 2277 } 2278 2279 void __init udp_init(void) 2280 { 2281 unsigned long limit; 2282 2283 udp_table_init(&udp_table, "UDP"); 2284 limit = nr_free_buffer_pages() / 8; 2285 limit = max(limit, 128UL); 2286 sysctl_udp_mem[0] = limit / 4 * 3; 2287 sysctl_udp_mem[1] = limit; 2288 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 2289 2290 sysctl_udp_rmem_min = SK_MEM_QUANTUM; 2291 sysctl_udp_wmem_min = SK_MEM_QUANTUM; 2292 } 2293 2294 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 2295 netdev_features_t features) 2296 { 2297 struct sk_buff *segs = ERR_PTR(-EINVAL); 2298 int mac_len = skb->mac_len; 2299 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); 2300 __be16 protocol = skb->protocol; 2301 netdev_features_t enc_features; 2302 int outer_hlen; 2303 2304 if (unlikely(!pskb_may_pull(skb, tnl_hlen))) 2305 goto out; 2306 2307 skb->encapsulation = 0; 2308 __skb_pull(skb, tnl_hlen); 2309 skb_reset_mac_header(skb); 2310 skb_set_network_header(skb, skb_inner_network_offset(skb)); 2311 skb->mac_len = skb_inner_network_offset(skb); 2312 skb->protocol = htons(ETH_P_TEB); 2313 2314 /* segment inner packet. */ 2315 enc_features = skb->dev->hw_enc_features & netif_skb_features(skb); 2316 segs = skb_mac_gso_segment(skb, enc_features); 2317 if (!segs || IS_ERR(segs)) 2318 goto out; 2319 2320 outer_hlen = skb_tnl_header_len(skb); 2321 skb = segs; 2322 do { 2323 struct udphdr *uh; 2324 int udp_offset = outer_hlen - tnl_hlen; 2325 2326 skb_reset_inner_headers(skb); 2327 skb->encapsulation = 1; 2328 2329 skb->mac_len = mac_len; 2330 2331 skb_push(skb, outer_hlen); 2332 skb_reset_mac_header(skb); 2333 skb_set_network_header(skb, mac_len); 2334 skb_set_transport_header(skb, udp_offset); 2335 uh = udp_hdr(skb); 2336 uh->len = htons(skb->len - udp_offset); 2337 2338 /* csum segment if tunnel sets skb with csum. */ 2339 if (unlikely(uh->check)) { 2340 struct iphdr *iph = ip_hdr(skb); 2341 2342 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, 2343 skb->len - udp_offset, 2344 IPPROTO_UDP, 0); 2345 uh->check = csum_fold(skb_checksum(skb, udp_offset, 2346 skb->len - udp_offset, 0)); 2347 if (uh->check == 0) 2348 uh->check = CSUM_MANGLED_0; 2349 2350 } 2351 skb->protocol = protocol; 2352 } while ((skb = skb->next)); 2353 out: 2354 return segs; 2355 } 2356