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/inetdevice.h> 94 #include <linux/in.h> 95 #include <linux/errno.h> 96 #include <linux/timer.h> 97 #include <linux/mm.h> 98 #include <linux/inet.h> 99 #include <linux/netdevice.h> 100 #include <linux/slab.h> 101 #include <net/tcp_states.h> 102 #include <linux/skbuff.h> 103 #include <linux/proc_fs.h> 104 #include <linux/seq_file.h> 105 #include <net/net_namespace.h> 106 #include <net/icmp.h> 107 #include <net/inet_hashtables.h> 108 #include <net/route.h> 109 #include <net/checksum.h> 110 #include <net/xfrm.h> 111 #include <trace/events/udp.h> 112 #include <linux/static_key.h> 113 #include <trace/events/skb.h> 114 #include <net/busy_poll.h> 115 #include "udp_impl.h" 116 117 struct udp_table udp_table __read_mostly; 118 EXPORT_SYMBOL(udp_table); 119 120 long sysctl_udp_mem[3] __read_mostly; 121 EXPORT_SYMBOL(sysctl_udp_mem); 122 123 int sysctl_udp_rmem_min __read_mostly; 124 EXPORT_SYMBOL(sysctl_udp_rmem_min); 125 126 int sysctl_udp_wmem_min __read_mostly; 127 EXPORT_SYMBOL(sysctl_udp_wmem_min); 128 129 atomic_long_t udp_memory_allocated; 130 EXPORT_SYMBOL(udp_memory_allocated); 131 132 #define MAX_UDP_PORTS 65536 133 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 134 135 static int udp_lib_lport_inuse(struct net *net, __u16 num, 136 const struct udp_hslot *hslot, 137 unsigned long *bitmap, 138 struct sock *sk, 139 int (*saddr_comp)(const struct sock *sk1, 140 const struct sock *sk2), 141 unsigned int log) 142 { 143 struct sock *sk2; 144 struct hlist_nulls_node *node; 145 kuid_t uid = sock_i_uid(sk); 146 147 sk_nulls_for_each(sk2, node, &hslot->head) { 148 if (net_eq(sock_net(sk2), net) && 149 sk2 != sk && 150 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 151 (!sk2->sk_reuse || !sk->sk_reuse) && 152 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 153 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 154 (!sk2->sk_reuseport || !sk->sk_reuseport || 155 !uid_eq(uid, sock_i_uid(sk2))) && 156 saddr_comp(sk, sk2)) { 157 if (!bitmap) 158 return 1; 159 __set_bit(udp_sk(sk2)->udp_port_hash >> log, bitmap); 160 } 161 } 162 return 0; 163 } 164 165 /* 166 * Note: we still hold spinlock of primary hash chain, so no other writer 167 * can insert/delete a socket with local_port == num 168 */ 169 static int udp_lib_lport_inuse2(struct net *net, __u16 num, 170 struct udp_hslot *hslot2, 171 struct sock *sk, 172 int (*saddr_comp)(const struct sock *sk1, 173 const struct sock *sk2)) 174 { 175 struct sock *sk2; 176 struct hlist_nulls_node *node; 177 kuid_t uid = sock_i_uid(sk); 178 int res = 0; 179 180 spin_lock(&hslot2->lock); 181 udp_portaddr_for_each_entry(sk2, node, &hslot2->head) { 182 if (net_eq(sock_net(sk2), net) && 183 sk2 != sk && 184 (udp_sk(sk2)->udp_port_hash == num) && 185 (!sk2->sk_reuse || !sk->sk_reuse) && 186 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 187 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 188 (!sk2->sk_reuseport || !sk->sk_reuseport || 189 !uid_eq(uid, sock_i_uid(sk2))) && 190 saddr_comp(sk, sk2)) { 191 res = 1; 192 break; 193 } 194 } 195 spin_unlock(&hslot2->lock); 196 return res; 197 } 198 199 /** 200 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 201 * 202 * @sk: socket struct in question 203 * @snum: port number to look up 204 * @saddr_comp: AF-dependent comparison of bound local IP addresses 205 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 206 * with NULL address 207 */ 208 int udp_lib_get_port(struct sock *sk, unsigned short snum, 209 int (*saddr_comp)(const struct sock *sk1, 210 const struct sock *sk2), 211 unsigned int hash2_nulladdr) 212 { 213 struct udp_hslot *hslot, *hslot2; 214 struct udp_table *udptable = sk->sk_prot->h.udp_table; 215 int error = 1; 216 struct net *net = sock_net(sk); 217 218 if (!snum) { 219 int low, high, remaining; 220 unsigned int rand; 221 unsigned short first, last; 222 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 223 224 inet_get_local_port_range(net, &low, &high); 225 remaining = (high - low) + 1; 226 227 rand = prandom_u32(); 228 first = reciprocal_scale(rand, remaining) + low; 229 /* 230 * force rand to be an odd multiple of UDP_HTABLE_SIZE 231 */ 232 rand = (rand | 1) * (udptable->mask + 1); 233 last = first + udptable->mask + 1; 234 do { 235 hslot = udp_hashslot(udptable, net, first); 236 bitmap_zero(bitmap, PORTS_PER_CHAIN); 237 spin_lock_bh(&hslot->lock); 238 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 239 saddr_comp, udptable->log); 240 241 snum = first; 242 /* 243 * Iterate on all possible values of snum for this hash. 244 * Using steps of an odd multiple of UDP_HTABLE_SIZE 245 * give us randomization and full range coverage. 246 */ 247 do { 248 if (low <= snum && snum <= high && 249 !test_bit(snum >> udptable->log, bitmap) && 250 !inet_is_local_reserved_port(net, snum)) 251 goto found; 252 snum += rand; 253 } while (snum != first); 254 spin_unlock_bh(&hslot->lock); 255 } while (++first != last); 256 goto fail; 257 } else { 258 hslot = udp_hashslot(udptable, net, snum); 259 spin_lock_bh(&hslot->lock); 260 if (hslot->count > 10) { 261 int exist; 262 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 263 264 slot2 &= udptable->mask; 265 hash2_nulladdr &= udptable->mask; 266 267 hslot2 = udp_hashslot2(udptable, slot2); 268 if (hslot->count < hslot2->count) 269 goto scan_primary_hash; 270 271 exist = udp_lib_lport_inuse2(net, snum, hslot2, 272 sk, saddr_comp); 273 if (!exist && (hash2_nulladdr != slot2)) { 274 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 275 exist = udp_lib_lport_inuse2(net, snum, hslot2, 276 sk, saddr_comp); 277 } 278 if (exist) 279 goto fail_unlock; 280 else 281 goto found; 282 } 283 scan_primary_hash: 284 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 285 saddr_comp, 0)) 286 goto fail_unlock; 287 } 288 found: 289 inet_sk(sk)->inet_num = snum; 290 udp_sk(sk)->udp_port_hash = snum; 291 udp_sk(sk)->udp_portaddr_hash ^= snum; 292 if (sk_unhashed(sk)) { 293 sk_nulls_add_node_rcu(sk, &hslot->head); 294 hslot->count++; 295 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 296 297 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 298 spin_lock(&hslot2->lock); 299 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 300 &hslot2->head); 301 hslot2->count++; 302 spin_unlock(&hslot2->lock); 303 } 304 error = 0; 305 fail_unlock: 306 spin_unlock_bh(&hslot->lock); 307 fail: 308 return error; 309 } 310 EXPORT_SYMBOL(udp_lib_get_port); 311 312 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 313 { 314 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 315 316 return (!ipv6_only_sock(sk2) && 317 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr || 318 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr)); 319 } 320 321 static u32 udp4_portaddr_hash(const struct net *net, __be32 saddr, 322 unsigned int port) 323 { 324 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 325 } 326 327 int udp_v4_get_port(struct sock *sk, unsigned short snum) 328 { 329 unsigned int hash2_nulladdr = 330 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 331 unsigned int hash2_partial = 332 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 333 334 /* precompute partial secondary hash */ 335 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 336 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr); 337 } 338 339 static inline int compute_score(struct sock *sk, struct net *net, 340 __be32 saddr, unsigned short hnum, __be16 sport, 341 __be32 daddr, __be16 dport, int dif) 342 { 343 int score; 344 struct inet_sock *inet; 345 346 if (!net_eq(sock_net(sk), net) || 347 udp_sk(sk)->udp_port_hash != hnum || 348 ipv6_only_sock(sk)) 349 return -1; 350 351 score = (sk->sk_family == PF_INET) ? 2 : 1; 352 inet = inet_sk(sk); 353 354 if (inet->inet_rcv_saddr) { 355 if (inet->inet_rcv_saddr != daddr) 356 return -1; 357 score += 4; 358 } 359 360 if (inet->inet_daddr) { 361 if (inet->inet_daddr != saddr) 362 return -1; 363 score += 4; 364 } 365 366 if (inet->inet_dport) { 367 if (inet->inet_dport != sport) 368 return -1; 369 score += 4; 370 } 371 372 if (sk->sk_bound_dev_if) { 373 if (sk->sk_bound_dev_if != dif) 374 return -1; 375 score += 4; 376 } 377 if (sk->sk_incoming_cpu == raw_smp_processor_id()) 378 score++; 379 return score; 380 } 381 382 /* 383 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num) 384 */ 385 static inline int compute_score2(struct sock *sk, struct net *net, 386 __be32 saddr, __be16 sport, 387 __be32 daddr, unsigned int hnum, int dif) 388 { 389 int score; 390 struct inet_sock *inet; 391 392 if (!net_eq(sock_net(sk), net) || 393 ipv6_only_sock(sk)) 394 return -1; 395 396 inet = inet_sk(sk); 397 398 if (inet->inet_rcv_saddr != daddr || 399 inet->inet_num != hnum) 400 return -1; 401 402 score = (sk->sk_family == PF_INET) ? 2 : 1; 403 404 if (inet->inet_daddr) { 405 if (inet->inet_daddr != saddr) 406 return -1; 407 score += 4; 408 } 409 410 if (inet->inet_dport) { 411 if (inet->inet_dport != sport) 412 return -1; 413 score += 4; 414 } 415 416 if (sk->sk_bound_dev_if) { 417 if (sk->sk_bound_dev_if != dif) 418 return -1; 419 score += 4; 420 } 421 422 if (sk->sk_incoming_cpu == raw_smp_processor_id()) 423 score++; 424 425 return score; 426 } 427 428 static u32 udp_ehashfn(const struct net *net, const __be32 laddr, 429 const __u16 lport, const __be32 faddr, 430 const __be16 fport) 431 { 432 static u32 udp_ehash_secret __read_mostly; 433 434 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); 435 436 return __inet_ehashfn(laddr, lport, faddr, fport, 437 udp_ehash_secret + net_hash_mix(net)); 438 } 439 440 /* called with read_rcu_lock() */ 441 static struct sock *udp4_lib_lookup2(struct net *net, 442 __be32 saddr, __be16 sport, 443 __be32 daddr, unsigned int hnum, int dif, 444 struct udp_hslot *hslot2, unsigned int slot2) 445 { 446 struct sock *sk, *result; 447 struct hlist_nulls_node *node; 448 int score, badness, matches = 0, reuseport = 0; 449 u32 hash = 0; 450 451 begin: 452 result = NULL; 453 badness = 0; 454 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { 455 score = compute_score2(sk, net, saddr, sport, 456 daddr, hnum, dif); 457 if (score > badness) { 458 result = sk; 459 badness = score; 460 reuseport = sk->sk_reuseport; 461 if (reuseport) { 462 hash = udp_ehashfn(net, daddr, hnum, 463 saddr, sport); 464 matches = 1; 465 } 466 } else if (score == badness && reuseport) { 467 matches++; 468 if (reciprocal_scale(hash, matches) == 0) 469 result = sk; 470 hash = next_pseudo_random32(hash); 471 } 472 } 473 /* 474 * if the nulls value we got at the end of this lookup is 475 * not the expected one, we must restart lookup. 476 * We probably met an item that was moved to another chain. 477 */ 478 if (get_nulls_value(node) != slot2) 479 goto begin; 480 if (result) { 481 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 482 result = NULL; 483 else if (unlikely(compute_score2(result, net, saddr, sport, 484 daddr, hnum, dif) < badness)) { 485 sock_put(result); 486 goto begin; 487 } 488 } 489 return result; 490 } 491 492 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 493 * harder than this. -DaveM 494 */ 495 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 496 __be16 sport, __be32 daddr, __be16 dport, 497 int dif, struct udp_table *udptable) 498 { 499 struct sock *sk, *result; 500 struct hlist_nulls_node *node; 501 unsigned short hnum = ntohs(dport); 502 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); 503 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; 504 int score, badness, matches = 0, reuseport = 0; 505 u32 hash = 0; 506 507 rcu_read_lock(); 508 if (hslot->count > 10) { 509 hash2 = udp4_portaddr_hash(net, daddr, hnum); 510 slot2 = hash2 & udptable->mask; 511 hslot2 = &udptable->hash2[slot2]; 512 if (hslot->count < hslot2->count) 513 goto begin; 514 515 result = udp4_lib_lookup2(net, saddr, sport, 516 daddr, hnum, dif, 517 hslot2, slot2); 518 if (!result) { 519 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 520 slot2 = hash2 & udptable->mask; 521 hslot2 = &udptable->hash2[slot2]; 522 if (hslot->count < hslot2->count) 523 goto begin; 524 525 result = udp4_lib_lookup2(net, saddr, sport, 526 htonl(INADDR_ANY), hnum, dif, 527 hslot2, slot2); 528 } 529 rcu_read_unlock(); 530 return result; 531 } 532 begin: 533 result = NULL; 534 badness = 0; 535 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 536 score = compute_score(sk, net, saddr, hnum, sport, 537 daddr, dport, dif); 538 if (score > badness) { 539 result = sk; 540 badness = score; 541 reuseport = sk->sk_reuseport; 542 if (reuseport) { 543 hash = udp_ehashfn(net, daddr, hnum, 544 saddr, sport); 545 matches = 1; 546 } 547 } else if (score == badness && reuseport) { 548 matches++; 549 if (reciprocal_scale(hash, matches) == 0) 550 result = sk; 551 hash = next_pseudo_random32(hash); 552 } 553 } 554 /* 555 * if the nulls value we got at the end of this lookup is 556 * not the expected one, we must restart lookup. 557 * We probably met an item that was moved to another chain. 558 */ 559 if (get_nulls_value(node) != slot) 560 goto begin; 561 562 if (result) { 563 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 564 result = NULL; 565 else if (unlikely(compute_score(result, net, saddr, hnum, sport, 566 daddr, dport, dif) < badness)) { 567 sock_put(result); 568 goto begin; 569 } 570 } 571 rcu_read_unlock(); 572 return result; 573 } 574 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 575 576 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 577 __be16 sport, __be16 dport, 578 struct udp_table *udptable) 579 { 580 const struct iphdr *iph = ip_hdr(skb); 581 582 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, 583 iph->daddr, dport, inet_iif(skb), 584 udptable); 585 } 586 587 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 588 __be32 daddr, __be16 dport, int dif) 589 { 590 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); 591 } 592 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 593 594 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, 595 __be16 loc_port, __be32 loc_addr, 596 __be16 rmt_port, __be32 rmt_addr, 597 int dif, unsigned short hnum) 598 { 599 struct inet_sock *inet = inet_sk(sk); 600 601 if (!net_eq(sock_net(sk), net) || 602 udp_sk(sk)->udp_port_hash != hnum || 603 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 604 (inet->inet_dport != rmt_port && inet->inet_dport) || 605 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) || 606 ipv6_only_sock(sk) || 607 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) 608 return false; 609 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif)) 610 return false; 611 return true; 612 } 613 614 /* 615 * This routine is called by the ICMP module when it gets some 616 * sort of error condition. If err < 0 then the socket should 617 * be closed and the error returned to the user. If err > 0 618 * it's just the icmp type << 8 | icmp code. 619 * Header points to the ip header of the error packet. We move 620 * on past this. Then (as it used to claim before adjustment) 621 * header points to the first 8 bytes of the udp header. We need 622 * to find the appropriate port. 623 */ 624 625 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 626 { 627 struct inet_sock *inet; 628 const struct iphdr *iph = (const struct iphdr *)skb->data; 629 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 630 const int type = icmp_hdr(skb)->type; 631 const int code = icmp_hdr(skb)->code; 632 struct sock *sk; 633 int harderr; 634 int err; 635 struct net *net = dev_net(skb->dev); 636 637 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 638 iph->saddr, uh->source, skb->dev->ifindex, udptable); 639 if (!sk) { 640 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 641 return; /* No socket for error */ 642 } 643 644 err = 0; 645 harderr = 0; 646 inet = inet_sk(sk); 647 648 switch (type) { 649 default: 650 case ICMP_TIME_EXCEEDED: 651 err = EHOSTUNREACH; 652 break; 653 case ICMP_SOURCE_QUENCH: 654 goto out; 655 case ICMP_PARAMETERPROB: 656 err = EPROTO; 657 harderr = 1; 658 break; 659 case ICMP_DEST_UNREACH: 660 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 661 ipv4_sk_update_pmtu(skb, sk, info); 662 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 663 err = EMSGSIZE; 664 harderr = 1; 665 break; 666 } 667 goto out; 668 } 669 err = EHOSTUNREACH; 670 if (code <= NR_ICMP_UNREACH) { 671 harderr = icmp_err_convert[code].fatal; 672 err = icmp_err_convert[code].errno; 673 } 674 break; 675 case ICMP_REDIRECT: 676 ipv4_sk_redirect(skb, sk); 677 goto out; 678 } 679 680 /* 681 * RFC1122: OK. Passes ICMP errors back to application, as per 682 * 4.1.3.3. 683 */ 684 if (!inet->recverr) { 685 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 686 goto out; 687 } else 688 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 689 690 sk->sk_err = err; 691 sk->sk_error_report(sk); 692 out: 693 sock_put(sk); 694 } 695 696 void udp_err(struct sk_buff *skb, u32 info) 697 { 698 __udp4_lib_err(skb, info, &udp_table); 699 } 700 701 /* 702 * Throw away all pending data and cancel the corking. Socket is locked. 703 */ 704 void udp_flush_pending_frames(struct sock *sk) 705 { 706 struct udp_sock *up = udp_sk(sk); 707 708 if (up->pending) { 709 up->len = 0; 710 up->pending = 0; 711 ip_flush_pending_frames(sk); 712 } 713 } 714 EXPORT_SYMBOL(udp_flush_pending_frames); 715 716 /** 717 * udp4_hwcsum - handle outgoing HW checksumming 718 * @skb: sk_buff containing the filled-in UDP header 719 * (checksum field must be zeroed out) 720 * @src: source IP address 721 * @dst: destination IP address 722 */ 723 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 724 { 725 struct udphdr *uh = udp_hdr(skb); 726 int offset = skb_transport_offset(skb); 727 int len = skb->len - offset; 728 int hlen = len; 729 __wsum csum = 0; 730 731 if (!skb_has_frag_list(skb)) { 732 /* 733 * Only one fragment on the socket. 734 */ 735 skb->csum_start = skb_transport_header(skb) - skb->head; 736 skb->csum_offset = offsetof(struct udphdr, check); 737 uh->check = ~csum_tcpudp_magic(src, dst, len, 738 IPPROTO_UDP, 0); 739 } else { 740 struct sk_buff *frags; 741 742 /* 743 * HW-checksum won't work as there are two or more 744 * fragments on the socket so that all csums of sk_buffs 745 * should be together 746 */ 747 skb_walk_frags(skb, frags) { 748 csum = csum_add(csum, frags->csum); 749 hlen -= frags->len; 750 } 751 752 csum = skb_checksum(skb, offset, hlen, csum); 753 skb->ip_summed = CHECKSUM_NONE; 754 755 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 756 if (uh->check == 0) 757 uh->check = CSUM_MANGLED_0; 758 } 759 } 760 EXPORT_SYMBOL_GPL(udp4_hwcsum); 761 762 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended 763 * for the simple case like when setting the checksum for a UDP tunnel. 764 */ 765 void udp_set_csum(bool nocheck, struct sk_buff *skb, 766 __be32 saddr, __be32 daddr, int len) 767 { 768 struct udphdr *uh = udp_hdr(skb); 769 770 if (nocheck) 771 uh->check = 0; 772 else if (skb_is_gso(skb)) 773 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 774 else if (skb_dst(skb) && skb_dst(skb)->dev && 775 (skb_dst(skb)->dev->features & NETIF_F_V4_CSUM)) { 776 777 BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL); 778 779 skb->ip_summed = CHECKSUM_PARTIAL; 780 skb->csum_start = skb_transport_header(skb) - skb->head; 781 skb->csum_offset = offsetof(struct udphdr, check); 782 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 783 } else { 784 __wsum csum; 785 786 BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL); 787 788 uh->check = 0; 789 csum = skb_checksum(skb, 0, len, 0); 790 uh->check = udp_v4_check(len, saddr, daddr, csum); 791 if (uh->check == 0) 792 uh->check = CSUM_MANGLED_0; 793 794 skb->ip_summed = CHECKSUM_UNNECESSARY; 795 } 796 } 797 EXPORT_SYMBOL(udp_set_csum); 798 799 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) 800 { 801 struct sock *sk = skb->sk; 802 struct inet_sock *inet = inet_sk(sk); 803 struct udphdr *uh; 804 int err = 0; 805 int is_udplite = IS_UDPLITE(sk); 806 int offset = skb_transport_offset(skb); 807 int len = skb->len - offset; 808 __wsum csum = 0; 809 810 /* 811 * Create a UDP header 812 */ 813 uh = udp_hdr(skb); 814 uh->source = inet->inet_sport; 815 uh->dest = fl4->fl4_dport; 816 uh->len = htons(len); 817 uh->check = 0; 818 819 if (is_udplite) /* UDP-Lite */ 820 csum = udplite_csum(skb); 821 822 else if (sk->sk_no_check_tx) { /* UDP csum disabled */ 823 824 skb->ip_summed = CHECKSUM_NONE; 825 goto send; 826 827 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 828 829 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 830 goto send; 831 832 } else 833 csum = udp_csum(skb); 834 835 /* add protocol-dependent pseudo-header */ 836 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 837 sk->sk_protocol, csum); 838 if (uh->check == 0) 839 uh->check = CSUM_MANGLED_0; 840 841 send: 842 err = ip_send_skb(sock_net(sk), skb); 843 if (err) { 844 if (err == -ENOBUFS && !inet->recverr) { 845 UDP_INC_STATS_USER(sock_net(sk), 846 UDP_MIB_SNDBUFERRORS, is_udplite); 847 err = 0; 848 } 849 } else 850 UDP_INC_STATS_USER(sock_net(sk), 851 UDP_MIB_OUTDATAGRAMS, is_udplite); 852 return err; 853 } 854 855 /* 856 * Push out all pending data as one UDP datagram. Socket is locked. 857 */ 858 int udp_push_pending_frames(struct sock *sk) 859 { 860 struct udp_sock *up = udp_sk(sk); 861 struct inet_sock *inet = inet_sk(sk); 862 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 863 struct sk_buff *skb; 864 int err = 0; 865 866 skb = ip_finish_skb(sk, fl4); 867 if (!skb) 868 goto out; 869 870 err = udp_send_skb(skb, fl4); 871 872 out: 873 up->len = 0; 874 up->pending = 0; 875 return err; 876 } 877 EXPORT_SYMBOL(udp_push_pending_frames); 878 879 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 880 { 881 struct inet_sock *inet = inet_sk(sk); 882 struct udp_sock *up = udp_sk(sk); 883 struct flowi4 fl4_stack; 884 struct flowi4 *fl4; 885 int ulen = len; 886 struct ipcm_cookie ipc; 887 struct rtable *rt = NULL; 888 int free = 0; 889 int connected = 0; 890 __be32 daddr, faddr, saddr; 891 __be16 dport; 892 u8 tos; 893 int err, is_udplite = IS_UDPLITE(sk); 894 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 895 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 896 struct sk_buff *skb; 897 struct ip_options_data opt_copy; 898 899 if (len > 0xFFFF) 900 return -EMSGSIZE; 901 902 /* 903 * Check the flags. 904 */ 905 906 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 907 return -EOPNOTSUPP; 908 909 ipc.opt = NULL; 910 ipc.tx_flags = 0; 911 ipc.ttl = 0; 912 ipc.tos = -1; 913 914 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 915 916 fl4 = &inet->cork.fl.u.ip4; 917 if (up->pending) { 918 /* 919 * There are pending frames. 920 * The socket lock must be held while it's corked. 921 */ 922 lock_sock(sk); 923 if (likely(up->pending)) { 924 if (unlikely(up->pending != AF_INET)) { 925 release_sock(sk); 926 return -EINVAL; 927 } 928 goto do_append_data; 929 } 930 release_sock(sk); 931 } 932 ulen += sizeof(struct udphdr); 933 934 /* 935 * Get and verify the address. 936 */ 937 if (msg->msg_name) { 938 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 939 if (msg->msg_namelen < sizeof(*usin)) 940 return -EINVAL; 941 if (usin->sin_family != AF_INET) { 942 if (usin->sin_family != AF_UNSPEC) 943 return -EAFNOSUPPORT; 944 } 945 946 daddr = usin->sin_addr.s_addr; 947 dport = usin->sin_port; 948 if (dport == 0) 949 return -EINVAL; 950 } else { 951 if (sk->sk_state != TCP_ESTABLISHED) 952 return -EDESTADDRREQ; 953 daddr = inet->inet_daddr; 954 dport = inet->inet_dport; 955 /* Open fast path for connected socket. 956 Route will not be used, if at least one option is set. 957 */ 958 connected = 1; 959 } 960 ipc.addr = inet->inet_saddr; 961 962 ipc.oif = sk->sk_bound_dev_if; 963 964 sock_tx_timestamp(sk, &ipc.tx_flags); 965 966 if (msg->msg_controllen) { 967 err = ip_cmsg_send(sock_net(sk), msg, &ipc, 968 sk->sk_family == AF_INET6); 969 if (err) 970 return err; 971 if (ipc.opt) 972 free = 1; 973 connected = 0; 974 } 975 if (!ipc.opt) { 976 struct ip_options_rcu *inet_opt; 977 978 rcu_read_lock(); 979 inet_opt = rcu_dereference(inet->inet_opt); 980 if (inet_opt) { 981 memcpy(&opt_copy, inet_opt, 982 sizeof(*inet_opt) + inet_opt->opt.optlen); 983 ipc.opt = &opt_copy.opt; 984 } 985 rcu_read_unlock(); 986 } 987 988 saddr = ipc.addr; 989 ipc.addr = faddr = daddr; 990 991 if (ipc.opt && ipc.opt->opt.srr) { 992 if (!daddr) 993 return -EINVAL; 994 faddr = ipc.opt->opt.faddr; 995 connected = 0; 996 } 997 tos = get_rttos(&ipc, inet); 998 if (sock_flag(sk, SOCK_LOCALROUTE) || 999 (msg->msg_flags & MSG_DONTROUTE) || 1000 (ipc.opt && ipc.opt->opt.is_strictroute)) { 1001 tos |= RTO_ONLINK; 1002 connected = 0; 1003 } 1004 1005 if (ipv4_is_multicast(daddr)) { 1006 if (!ipc.oif) 1007 ipc.oif = inet->mc_index; 1008 if (!saddr) 1009 saddr = inet->mc_addr; 1010 connected = 0; 1011 } else if (!ipc.oif) 1012 ipc.oif = inet->uc_index; 1013 1014 if (connected) 1015 rt = (struct rtable *)sk_dst_check(sk, 0); 1016 1017 if (!rt) { 1018 struct net *net = sock_net(sk); 1019 __u8 flow_flags = inet_sk_flowi_flags(sk); 1020 1021 fl4 = &fl4_stack; 1022 1023 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, 1024 RT_SCOPE_UNIVERSE, sk->sk_protocol, 1025 flow_flags, 1026 faddr, saddr, dport, inet->inet_sport); 1027 1028 if (!saddr && ipc.oif) 1029 l3mdev_get_saddr(net, ipc.oif, fl4); 1030 1031 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 1032 rt = ip_route_output_flow(net, fl4, sk); 1033 if (IS_ERR(rt)) { 1034 err = PTR_ERR(rt); 1035 rt = NULL; 1036 if (err == -ENETUNREACH) 1037 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 1038 goto out; 1039 } 1040 1041 err = -EACCES; 1042 if ((rt->rt_flags & RTCF_BROADCAST) && 1043 !sock_flag(sk, SOCK_BROADCAST)) 1044 goto out; 1045 if (connected) 1046 sk_dst_set(sk, dst_clone(&rt->dst)); 1047 } 1048 1049 if (msg->msg_flags&MSG_CONFIRM) 1050 goto do_confirm; 1051 back_from_confirm: 1052 1053 saddr = fl4->saddr; 1054 if (!ipc.addr) 1055 daddr = ipc.addr = fl4->daddr; 1056 1057 /* Lockless fast path for the non-corking case. */ 1058 if (!corkreq) { 1059 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen, 1060 sizeof(struct udphdr), &ipc, &rt, 1061 msg->msg_flags); 1062 err = PTR_ERR(skb); 1063 if (!IS_ERR_OR_NULL(skb)) 1064 err = udp_send_skb(skb, fl4); 1065 goto out; 1066 } 1067 1068 lock_sock(sk); 1069 if (unlikely(up->pending)) { 1070 /* The socket is already corked while preparing it. */ 1071 /* ... which is an evident application bug. --ANK */ 1072 release_sock(sk); 1073 1074 net_dbg_ratelimited("cork app bug 2\n"); 1075 err = -EINVAL; 1076 goto out; 1077 } 1078 /* 1079 * Now cork the socket to pend data. 1080 */ 1081 fl4 = &inet->cork.fl.u.ip4; 1082 fl4->daddr = daddr; 1083 fl4->saddr = saddr; 1084 fl4->fl4_dport = dport; 1085 fl4->fl4_sport = inet->inet_sport; 1086 up->pending = AF_INET; 1087 1088 do_append_data: 1089 up->len += ulen; 1090 err = ip_append_data(sk, fl4, getfrag, msg, ulen, 1091 sizeof(struct udphdr), &ipc, &rt, 1092 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1093 if (err) 1094 udp_flush_pending_frames(sk); 1095 else if (!corkreq) 1096 err = udp_push_pending_frames(sk); 1097 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1098 up->pending = 0; 1099 release_sock(sk); 1100 1101 out: 1102 ip_rt_put(rt); 1103 if (free) 1104 kfree(ipc.opt); 1105 if (!err) 1106 return len; 1107 /* 1108 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1109 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1110 * we don't have a good statistic (IpOutDiscards but it can be too many 1111 * things). We could add another new stat but at least for now that 1112 * seems like overkill. 1113 */ 1114 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1115 UDP_INC_STATS_USER(sock_net(sk), 1116 UDP_MIB_SNDBUFERRORS, is_udplite); 1117 } 1118 return err; 1119 1120 do_confirm: 1121 dst_confirm(&rt->dst); 1122 if (!(msg->msg_flags&MSG_PROBE) || len) 1123 goto back_from_confirm; 1124 err = 0; 1125 goto out; 1126 } 1127 EXPORT_SYMBOL(udp_sendmsg); 1128 1129 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1130 size_t size, int flags) 1131 { 1132 struct inet_sock *inet = inet_sk(sk); 1133 struct udp_sock *up = udp_sk(sk); 1134 int ret; 1135 1136 if (flags & MSG_SENDPAGE_NOTLAST) 1137 flags |= MSG_MORE; 1138 1139 if (!up->pending) { 1140 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1141 1142 /* Call udp_sendmsg to specify destination address which 1143 * sendpage interface can't pass. 1144 * This will succeed only when the socket is connected. 1145 */ 1146 ret = udp_sendmsg(sk, &msg, 0); 1147 if (ret < 0) 1148 return ret; 1149 } 1150 1151 lock_sock(sk); 1152 1153 if (unlikely(!up->pending)) { 1154 release_sock(sk); 1155 1156 net_dbg_ratelimited("udp cork app bug 3\n"); 1157 return -EINVAL; 1158 } 1159 1160 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1161 page, offset, size, flags); 1162 if (ret == -EOPNOTSUPP) { 1163 release_sock(sk); 1164 return sock_no_sendpage(sk->sk_socket, page, offset, 1165 size, flags); 1166 } 1167 if (ret < 0) { 1168 udp_flush_pending_frames(sk); 1169 goto out; 1170 } 1171 1172 up->len += size; 1173 if (!(up->corkflag || (flags&MSG_MORE))) 1174 ret = udp_push_pending_frames(sk); 1175 if (!ret) 1176 ret = size; 1177 out: 1178 release_sock(sk); 1179 return ret; 1180 } 1181 1182 /** 1183 * first_packet_length - return length of first packet in receive queue 1184 * @sk: socket 1185 * 1186 * Drops all bad checksum frames, until a valid one is found. 1187 * Returns the length of found skb, or 0 if none is found. 1188 */ 1189 static unsigned int first_packet_length(struct sock *sk) 1190 { 1191 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue; 1192 struct sk_buff *skb; 1193 unsigned int res; 1194 1195 __skb_queue_head_init(&list_kill); 1196 1197 spin_lock_bh(&rcvq->lock); 1198 while ((skb = skb_peek(rcvq)) != NULL && 1199 udp_lib_checksum_complete(skb)) { 1200 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, 1201 IS_UDPLITE(sk)); 1202 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1203 IS_UDPLITE(sk)); 1204 atomic_inc(&sk->sk_drops); 1205 __skb_unlink(skb, rcvq); 1206 __skb_queue_tail(&list_kill, skb); 1207 } 1208 res = skb ? skb->len : 0; 1209 spin_unlock_bh(&rcvq->lock); 1210 1211 if (!skb_queue_empty(&list_kill)) { 1212 bool slow = lock_sock_fast(sk); 1213 1214 __skb_queue_purge(&list_kill); 1215 sk_mem_reclaim_partial(sk); 1216 unlock_sock_fast(sk, slow); 1217 } 1218 return res; 1219 } 1220 1221 /* 1222 * IOCTL requests applicable to the UDP protocol 1223 */ 1224 1225 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1226 { 1227 switch (cmd) { 1228 case SIOCOUTQ: 1229 { 1230 int amount = sk_wmem_alloc_get(sk); 1231 1232 return put_user(amount, (int __user *)arg); 1233 } 1234 1235 case SIOCINQ: 1236 { 1237 unsigned int amount = first_packet_length(sk); 1238 1239 if (amount) 1240 /* 1241 * We will only return the amount 1242 * of this packet since that is all 1243 * that will be read. 1244 */ 1245 amount -= sizeof(struct udphdr); 1246 1247 return put_user(amount, (int __user *)arg); 1248 } 1249 1250 default: 1251 return -ENOIOCTLCMD; 1252 } 1253 1254 return 0; 1255 } 1256 EXPORT_SYMBOL(udp_ioctl); 1257 1258 /* 1259 * This should be easy, if there is something there we 1260 * return it, otherwise we block. 1261 */ 1262 1263 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 1264 int flags, int *addr_len) 1265 { 1266 struct inet_sock *inet = inet_sk(sk); 1267 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 1268 struct sk_buff *skb; 1269 unsigned int ulen, copied; 1270 int peeked, off = 0; 1271 int err; 1272 int is_udplite = IS_UDPLITE(sk); 1273 bool slow; 1274 1275 if (flags & MSG_ERRQUEUE) 1276 return ip_recv_error(sk, msg, len, addr_len); 1277 1278 try_again: 1279 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), 1280 &peeked, &off, &err); 1281 if (!skb) 1282 goto out; 1283 1284 ulen = skb->len - sizeof(struct udphdr); 1285 copied = len; 1286 if (copied > ulen) 1287 copied = ulen; 1288 else if (copied < ulen) 1289 msg->msg_flags |= MSG_TRUNC; 1290 1291 /* 1292 * If checksum is needed at all, try to do it while copying the 1293 * data. If the data is truncated, or if we only want a partial 1294 * coverage checksum (UDP-Lite), do it before the copy. 1295 */ 1296 1297 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { 1298 if (udp_lib_checksum_complete(skb)) 1299 goto csum_copy_err; 1300 } 1301 1302 if (skb_csum_unnecessary(skb)) 1303 err = skb_copy_datagram_msg(skb, sizeof(struct udphdr), 1304 msg, copied); 1305 else { 1306 err = skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), 1307 msg); 1308 1309 if (err == -EINVAL) 1310 goto csum_copy_err; 1311 } 1312 1313 if (unlikely(err)) { 1314 trace_kfree_skb(skb, udp_recvmsg); 1315 if (!peeked) { 1316 atomic_inc(&sk->sk_drops); 1317 UDP_INC_STATS_USER(sock_net(sk), 1318 UDP_MIB_INERRORS, is_udplite); 1319 } 1320 goto out_free; 1321 } 1322 1323 if (!peeked) 1324 UDP_INC_STATS_USER(sock_net(sk), 1325 UDP_MIB_INDATAGRAMS, is_udplite); 1326 1327 sock_recv_ts_and_drops(msg, sk, skb); 1328 1329 /* Copy the address. */ 1330 if (sin) { 1331 sin->sin_family = AF_INET; 1332 sin->sin_port = udp_hdr(skb)->source; 1333 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1334 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1335 *addr_len = sizeof(*sin); 1336 } 1337 if (inet->cmsg_flags) 1338 ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr)); 1339 1340 err = copied; 1341 if (flags & MSG_TRUNC) 1342 err = ulen; 1343 1344 out_free: 1345 skb_free_datagram_locked(sk, skb); 1346 out: 1347 return err; 1348 1349 csum_copy_err: 1350 slow = lock_sock_fast(sk); 1351 if (!skb_kill_datagram(sk, skb, flags)) { 1352 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1353 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1354 } 1355 unlock_sock_fast(sk, slow); 1356 1357 /* starting over for a new packet, but check if we need to yield */ 1358 cond_resched(); 1359 msg->msg_flags &= ~MSG_TRUNC; 1360 goto try_again; 1361 } 1362 1363 int udp_disconnect(struct sock *sk, int flags) 1364 { 1365 struct inet_sock *inet = inet_sk(sk); 1366 /* 1367 * 1003.1g - break association. 1368 */ 1369 1370 sk->sk_state = TCP_CLOSE; 1371 inet->inet_daddr = 0; 1372 inet->inet_dport = 0; 1373 sock_rps_reset_rxhash(sk); 1374 sk->sk_bound_dev_if = 0; 1375 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1376 inet_reset_saddr(sk); 1377 1378 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1379 sk->sk_prot->unhash(sk); 1380 inet->inet_sport = 0; 1381 } 1382 sk_dst_reset(sk); 1383 return 0; 1384 } 1385 EXPORT_SYMBOL(udp_disconnect); 1386 1387 void udp_lib_unhash(struct sock *sk) 1388 { 1389 if (sk_hashed(sk)) { 1390 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1391 struct udp_hslot *hslot, *hslot2; 1392 1393 hslot = udp_hashslot(udptable, sock_net(sk), 1394 udp_sk(sk)->udp_port_hash); 1395 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1396 1397 spin_lock_bh(&hslot->lock); 1398 if (sk_nulls_del_node_init_rcu(sk)) { 1399 hslot->count--; 1400 inet_sk(sk)->inet_num = 0; 1401 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1402 1403 spin_lock(&hslot2->lock); 1404 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1405 hslot2->count--; 1406 spin_unlock(&hslot2->lock); 1407 } 1408 spin_unlock_bh(&hslot->lock); 1409 } 1410 } 1411 EXPORT_SYMBOL(udp_lib_unhash); 1412 1413 /* 1414 * inet_rcv_saddr was changed, we must rehash secondary hash 1415 */ 1416 void udp_lib_rehash(struct sock *sk, u16 newhash) 1417 { 1418 if (sk_hashed(sk)) { 1419 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1420 struct udp_hslot *hslot, *hslot2, *nhslot2; 1421 1422 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1423 nhslot2 = udp_hashslot2(udptable, newhash); 1424 udp_sk(sk)->udp_portaddr_hash = newhash; 1425 if (hslot2 != nhslot2) { 1426 hslot = udp_hashslot(udptable, sock_net(sk), 1427 udp_sk(sk)->udp_port_hash); 1428 /* we must lock primary chain too */ 1429 spin_lock_bh(&hslot->lock); 1430 1431 spin_lock(&hslot2->lock); 1432 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1433 hslot2->count--; 1434 spin_unlock(&hslot2->lock); 1435 1436 spin_lock(&nhslot2->lock); 1437 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1438 &nhslot2->head); 1439 nhslot2->count++; 1440 spin_unlock(&nhslot2->lock); 1441 1442 spin_unlock_bh(&hslot->lock); 1443 } 1444 } 1445 } 1446 EXPORT_SYMBOL(udp_lib_rehash); 1447 1448 static void udp_v4_rehash(struct sock *sk) 1449 { 1450 u16 new_hash = udp4_portaddr_hash(sock_net(sk), 1451 inet_sk(sk)->inet_rcv_saddr, 1452 inet_sk(sk)->inet_num); 1453 udp_lib_rehash(sk, new_hash); 1454 } 1455 1456 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1457 { 1458 int rc; 1459 1460 if (inet_sk(sk)->inet_daddr) { 1461 sock_rps_save_rxhash(sk, skb); 1462 sk_mark_napi_id(sk, skb); 1463 sk_incoming_cpu_update(sk); 1464 } 1465 1466 rc = sock_queue_rcv_skb(sk, skb); 1467 if (rc < 0) { 1468 int is_udplite = IS_UDPLITE(sk); 1469 1470 /* Note that an ENOMEM error is charged twice */ 1471 if (rc == -ENOMEM) 1472 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1473 is_udplite); 1474 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1475 kfree_skb(skb); 1476 trace_udp_fail_queue_rcv_skb(rc, sk); 1477 return -1; 1478 } 1479 1480 return 0; 1481 1482 } 1483 1484 static struct static_key udp_encap_needed __read_mostly; 1485 void udp_encap_enable(void) 1486 { 1487 if (!static_key_enabled(&udp_encap_needed)) 1488 static_key_slow_inc(&udp_encap_needed); 1489 } 1490 EXPORT_SYMBOL(udp_encap_enable); 1491 1492 /* returns: 1493 * -1: error 1494 * 0: success 1495 * >0: "udp encap" protocol resubmission 1496 * 1497 * Note that in the success and error cases, the skb is assumed to 1498 * have either been requeued or freed. 1499 */ 1500 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1501 { 1502 struct udp_sock *up = udp_sk(sk); 1503 int rc; 1504 int is_udplite = IS_UDPLITE(sk); 1505 1506 /* 1507 * Charge it to the socket, dropping if the queue is full. 1508 */ 1509 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1510 goto drop; 1511 nf_reset(skb); 1512 1513 if (static_key_false(&udp_encap_needed) && up->encap_type) { 1514 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 1515 1516 /* 1517 * This is an encapsulation socket so pass the skb to 1518 * the socket's udp_encap_rcv() hook. Otherwise, just 1519 * fall through and pass this up the UDP socket. 1520 * up->encap_rcv() returns the following value: 1521 * =0 if skb was successfully passed to the encap 1522 * handler or was discarded by it. 1523 * >0 if skb should be passed on to UDP. 1524 * <0 if skb should be resubmitted as proto -N 1525 */ 1526 1527 /* if we're overly short, let UDP handle it */ 1528 encap_rcv = ACCESS_ONCE(up->encap_rcv); 1529 if (skb->len > sizeof(struct udphdr) && encap_rcv) { 1530 int ret; 1531 1532 /* Verify checksum before giving to encap */ 1533 if (udp_lib_checksum_complete(skb)) 1534 goto csum_error; 1535 1536 ret = encap_rcv(sk, skb); 1537 if (ret <= 0) { 1538 UDP_INC_STATS_BH(sock_net(sk), 1539 UDP_MIB_INDATAGRAMS, 1540 is_udplite); 1541 return -ret; 1542 } 1543 } 1544 1545 /* FALLTHROUGH -- it's a UDP Packet */ 1546 } 1547 1548 /* 1549 * UDP-Lite specific tests, ignored on UDP sockets 1550 */ 1551 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1552 1553 /* 1554 * MIB statistics other than incrementing the error count are 1555 * disabled for the following two types of errors: these depend 1556 * on the application settings, not on the functioning of the 1557 * protocol stack as such. 1558 * 1559 * RFC 3828 here recommends (sec 3.3): "There should also be a 1560 * way ... to ... at least let the receiving application block 1561 * delivery of packets with coverage values less than a value 1562 * provided by the application." 1563 */ 1564 if (up->pcrlen == 0) { /* full coverage was set */ 1565 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n", 1566 UDP_SKB_CB(skb)->cscov, skb->len); 1567 goto drop; 1568 } 1569 /* The next case involves violating the min. coverage requested 1570 * by the receiver. This is subtle: if receiver wants x and x is 1571 * greater than the buffersize/MTU then receiver will complain 1572 * that it wants x while sender emits packets of smaller size y. 1573 * Therefore the above ...()->partial_cov statement is essential. 1574 */ 1575 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1576 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n", 1577 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1578 goto drop; 1579 } 1580 } 1581 1582 if (rcu_access_pointer(sk->sk_filter) && 1583 udp_lib_checksum_complete(skb)) 1584 goto csum_error; 1585 1586 if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) { 1587 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1588 is_udplite); 1589 goto drop; 1590 } 1591 1592 rc = 0; 1593 1594 ipv4_pktinfo_prepare(sk, skb); 1595 bh_lock_sock(sk); 1596 if (!sock_owned_by_user(sk)) 1597 rc = __udp_queue_rcv_skb(sk, skb); 1598 else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) { 1599 bh_unlock_sock(sk); 1600 goto drop; 1601 } 1602 bh_unlock_sock(sk); 1603 1604 return rc; 1605 1606 csum_error: 1607 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1608 drop: 1609 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1610 atomic_inc(&sk->sk_drops); 1611 kfree_skb(skb); 1612 return -1; 1613 } 1614 1615 static void flush_stack(struct sock **stack, unsigned int count, 1616 struct sk_buff *skb, unsigned int final) 1617 { 1618 unsigned int i; 1619 struct sk_buff *skb1 = NULL; 1620 struct sock *sk; 1621 1622 for (i = 0; i < count; i++) { 1623 sk = stack[i]; 1624 if (likely(!skb1)) 1625 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); 1626 1627 if (!skb1) { 1628 atomic_inc(&sk->sk_drops); 1629 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1630 IS_UDPLITE(sk)); 1631 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1632 IS_UDPLITE(sk)); 1633 } 1634 1635 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0) 1636 skb1 = NULL; 1637 1638 sock_put(sk); 1639 } 1640 if (unlikely(skb1)) 1641 kfree_skb(skb1); 1642 } 1643 1644 /* For TCP sockets, sk_rx_dst is protected by socket lock 1645 * For UDP, we use xchg() to guard against concurrent changes. 1646 */ 1647 static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 1648 { 1649 struct dst_entry *old; 1650 1651 dst_hold(dst); 1652 old = xchg(&sk->sk_rx_dst, dst); 1653 dst_release(old); 1654 } 1655 1656 /* 1657 * Multicasts and broadcasts go to each listener. 1658 * 1659 * Note: called only from the BH handler context. 1660 */ 1661 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 1662 struct udphdr *uh, 1663 __be32 saddr, __be32 daddr, 1664 struct udp_table *udptable, 1665 int proto) 1666 { 1667 struct sock *sk, *stack[256 / sizeof(struct sock *)]; 1668 struct hlist_nulls_node *node; 1669 unsigned short hnum = ntohs(uh->dest); 1670 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 1671 int dif = skb->dev->ifindex; 1672 unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node); 1673 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 1674 bool inner_flushed = false; 1675 1676 if (use_hash2) { 1677 hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & 1678 udp_table.mask; 1679 hash2 = udp4_portaddr_hash(net, daddr, hnum) & udp_table.mask; 1680 start_lookup: 1681 hslot = &udp_table.hash2[hash2]; 1682 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 1683 } 1684 1685 spin_lock(&hslot->lock); 1686 sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) { 1687 if (__udp_is_mcast_sock(net, sk, 1688 uh->dest, daddr, 1689 uh->source, saddr, 1690 dif, hnum)) { 1691 if (unlikely(count == ARRAY_SIZE(stack))) { 1692 flush_stack(stack, count, skb, ~0); 1693 inner_flushed = true; 1694 count = 0; 1695 } 1696 stack[count++] = sk; 1697 sock_hold(sk); 1698 } 1699 } 1700 1701 spin_unlock(&hslot->lock); 1702 1703 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 1704 if (use_hash2 && hash2 != hash2_any) { 1705 hash2 = hash2_any; 1706 goto start_lookup; 1707 } 1708 1709 /* 1710 * do the slow work with no lock held 1711 */ 1712 if (count) { 1713 flush_stack(stack, count, skb, count - 1); 1714 } else { 1715 if (!inner_flushed) 1716 UDP_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI, 1717 proto == IPPROTO_UDPLITE); 1718 consume_skb(skb); 1719 } 1720 return 0; 1721 } 1722 1723 /* Initialize UDP checksum. If exited with zero value (success), 1724 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1725 * Otherwise, csum completion requires chacksumming packet body, 1726 * including udp header and folding it to skb->csum. 1727 */ 1728 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 1729 int proto) 1730 { 1731 int err; 1732 1733 UDP_SKB_CB(skb)->partial_cov = 0; 1734 UDP_SKB_CB(skb)->cscov = skb->len; 1735 1736 if (proto == IPPROTO_UDPLITE) { 1737 err = udplite_checksum_init(skb, uh); 1738 if (err) 1739 return err; 1740 } 1741 1742 return skb_checksum_init_zero_check(skb, proto, uh->check, 1743 inet_compute_pseudo); 1744 } 1745 1746 /* 1747 * All we need to do is get the socket, and then do a checksum. 1748 */ 1749 1750 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 1751 int proto) 1752 { 1753 struct sock *sk; 1754 struct udphdr *uh; 1755 unsigned short ulen; 1756 struct rtable *rt = skb_rtable(skb); 1757 __be32 saddr, daddr; 1758 struct net *net = dev_net(skb->dev); 1759 1760 /* 1761 * Validate the packet. 1762 */ 1763 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1764 goto drop; /* No space for header. */ 1765 1766 uh = udp_hdr(skb); 1767 ulen = ntohs(uh->len); 1768 saddr = ip_hdr(skb)->saddr; 1769 daddr = ip_hdr(skb)->daddr; 1770 1771 if (ulen > skb->len) 1772 goto short_packet; 1773 1774 if (proto == IPPROTO_UDP) { 1775 /* UDP validates ulen. */ 1776 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1777 goto short_packet; 1778 uh = udp_hdr(skb); 1779 } 1780 1781 if (udp4_csum_init(skb, uh, proto)) 1782 goto csum_error; 1783 1784 sk = skb_steal_sock(skb); 1785 if (sk) { 1786 struct dst_entry *dst = skb_dst(skb); 1787 int ret; 1788 1789 if (unlikely(sk->sk_rx_dst != dst)) 1790 udp_sk_rx_dst_set(sk, dst); 1791 1792 ret = udp_queue_rcv_skb(sk, skb); 1793 sock_put(sk); 1794 /* a return value > 0 means to resubmit the input, but 1795 * it wants the return to be -protocol, or 0 1796 */ 1797 if (ret > 0) 1798 return -ret; 1799 return 0; 1800 } 1801 1802 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1803 return __udp4_lib_mcast_deliver(net, skb, uh, 1804 saddr, daddr, udptable, proto); 1805 1806 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 1807 if (sk) { 1808 int ret; 1809 1810 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 1811 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, 1812 inet_compute_pseudo); 1813 1814 ret = udp_queue_rcv_skb(sk, skb); 1815 sock_put(sk); 1816 1817 /* a return value > 0 means to resubmit the input, but 1818 * it wants the return to be -protocol, or 0 1819 */ 1820 if (ret > 0) 1821 return -ret; 1822 return 0; 1823 } 1824 1825 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1826 goto drop; 1827 nf_reset(skb); 1828 1829 /* No socket. Drop packet silently, if checksum is wrong */ 1830 if (udp_lib_checksum_complete(skb)) 1831 goto csum_error; 1832 1833 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 1834 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1835 1836 /* 1837 * Hmm. We got an UDP packet to a port to which we 1838 * don't wanna listen. Ignore it. 1839 */ 1840 kfree_skb(skb); 1841 return 0; 1842 1843 short_packet: 1844 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 1845 proto == IPPROTO_UDPLITE ? "Lite" : "", 1846 &saddr, ntohs(uh->source), 1847 ulen, skb->len, 1848 &daddr, ntohs(uh->dest)); 1849 goto drop; 1850 1851 csum_error: 1852 /* 1853 * RFC1122: OK. Discards the bad packet silently (as far as 1854 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1855 */ 1856 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 1857 proto == IPPROTO_UDPLITE ? "Lite" : "", 1858 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 1859 ulen); 1860 UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 1861 drop: 1862 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1863 kfree_skb(skb); 1864 return 0; 1865 } 1866 1867 /* We can only early demux multicast if there is a single matching socket. 1868 * If more than one socket found returns NULL 1869 */ 1870 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, 1871 __be16 loc_port, __be32 loc_addr, 1872 __be16 rmt_port, __be32 rmt_addr, 1873 int dif) 1874 { 1875 struct sock *sk, *result; 1876 struct hlist_nulls_node *node; 1877 unsigned short hnum = ntohs(loc_port); 1878 unsigned int count, slot = udp_hashfn(net, hnum, udp_table.mask); 1879 struct udp_hslot *hslot = &udp_table.hash[slot]; 1880 1881 /* Do not bother scanning a too big list */ 1882 if (hslot->count > 10) 1883 return NULL; 1884 1885 rcu_read_lock(); 1886 begin: 1887 count = 0; 1888 result = NULL; 1889 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 1890 if (__udp_is_mcast_sock(net, sk, 1891 loc_port, loc_addr, 1892 rmt_port, rmt_addr, 1893 dif, hnum)) { 1894 result = sk; 1895 ++count; 1896 } 1897 } 1898 /* 1899 * if the nulls value we got at the end of this lookup is 1900 * not the expected one, we must restart lookup. 1901 * We probably met an item that was moved to another chain. 1902 */ 1903 if (get_nulls_value(node) != slot) 1904 goto begin; 1905 1906 if (result) { 1907 if (count != 1 || 1908 unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 1909 result = NULL; 1910 else if (unlikely(!__udp_is_mcast_sock(net, result, 1911 loc_port, loc_addr, 1912 rmt_port, rmt_addr, 1913 dif, hnum))) { 1914 sock_put(result); 1915 result = NULL; 1916 } 1917 } 1918 rcu_read_unlock(); 1919 return result; 1920 } 1921 1922 /* For unicast we should only early demux connected sockets or we can 1923 * break forwarding setups. The chains here can be long so only check 1924 * if the first socket is an exact match and if not move on. 1925 */ 1926 static struct sock *__udp4_lib_demux_lookup(struct net *net, 1927 __be16 loc_port, __be32 loc_addr, 1928 __be16 rmt_port, __be32 rmt_addr, 1929 int dif) 1930 { 1931 struct sock *sk, *result; 1932 struct hlist_nulls_node *node; 1933 unsigned short hnum = ntohs(loc_port); 1934 unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum); 1935 unsigned int slot2 = hash2 & udp_table.mask; 1936 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 1937 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); 1938 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 1939 1940 rcu_read_lock(); 1941 result = NULL; 1942 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { 1943 if (INET_MATCH(sk, net, acookie, 1944 rmt_addr, loc_addr, ports, dif)) 1945 result = sk; 1946 /* Only check first socket in chain */ 1947 break; 1948 } 1949 1950 if (result) { 1951 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 1952 result = NULL; 1953 else if (unlikely(!INET_MATCH(sk, net, acookie, 1954 rmt_addr, loc_addr, 1955 ports, dif))) { 1956 sock_put(result); 1957 result = NULL; 1958 } 1959 } 1960 rcu_read_unlock(); 1961 return result; 1962 } 1963 1964 void udp_v4_early_demux(struct sk_buff *skb) 1965 { 1966 struct net *net = dev_net(skb->dev); 1967 const struct iphdr *iph; 1968 const struct udphdr *uh; 1969 struct sock *sk; 1970 struct dst_entry *dst; 1971 int dif = skb->dev->ifindex; 1972 int ours; 1973 1974 /* validate the packet */ 1975 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) 1976 return; 1977 1978 iph = ip_hdr(skb); 1979 uh = udp_hdr(skb); 1980 1981 if (skb->pkt_type == PACKET_BROADCAST || 1982 skb->pkt_type == PACKET_MULTICAST) { 1983 struct in_device *in_dev = __in_dev_get_rcu(skb->dev); 1984 1985 if (!in_dev) 1986 return; 1987 1988 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, 1989 iph->protocol); 1990 if (!ours) 1991 return; 1992 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, 1993 uh->source, iph->saddr, dif); 1994 } else if (skb->pkt_type == PACKET_HOST) { 1995 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, 1996 uh->source, iph->saddr, dif); 1997 } else { 1998 return; 1999 } 2000 2001 if (!sk) 2002 return; 2003 2004 skb->sk = sk; 2005 skb->destructor = sock_efree; 2006 dst = READ_ONCE(sk->sk_rx_dst); 2007 2008 if (dst) 2009 dst = dst_check(dst, 0); 2010 if (dst) { 2011 /* DST_NOCACHE can not be used without taking a reference */ 2012 if (dst->flags & DST_NOCACHE) { 2013 if (likely(atomic_inc_not_zero(&dst->__refcnt))) 2014 skb_dst_set(skb, dst); 2015 } else { 2016 skb_dst_set_noref(skb, dst); 2017 } 2018 } 2019 } 2020 2021 int udp_rcv(struct sk_buff *skb) 2022 { 2023 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 2024 } 2025 2026 void udp_destroy_sock(struct sock *sk) 2027 { 2028 struct udp_sock *up = udp_sk(sk); 2029 bool slow = lock_sock_fast(sk); 2030 udp_flush_pending_frames(sk); 2031 unlock_sock_fast(sk, slow); 2032 if (static_key_false(&udp_encap_needed) && up->encap_type) { 2033 void (*encap_destroy)(struct sock *sk); 2034 encap_destroy = ACCESS_ONCE(up->encap_destroy); 2035 if (encap_destroy) 2036 encap_destroy(sk); 2037 } 2038 } 2039 2040 /* 2041 * Socket option code for UDP 2042 */ 2043 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 2044 char __user *optval, unsigned int optlen, 2045 int (*push_pending_frames)(struct sock *)) 2046 { 2047 struct udp_sock *up = udp_sk(sk); 2048 int val, valbool; 2049 int err = 0; 2050 int is_udplite = IS_UDPLITE(sk); 2051 2052 if (optlen < sizeof(int)) 2053 return -EINVAL; 2054 2055 if (get_user(val, (int __user *)optval)) 2056 return -EFAULT; 2057 2058 valbool = val ? 1 : 0; 2059 2060 switch (optname) { 2061 case UDP_CORK: 2062 if (val != 0) { 2063 up->corkflag = 1; 2064 } else { 2065 up->corkflag = 0; 2066 lock_sock(sk); 2067 push_pending_frames(sk); 2068 release_sock(sk); 2069 } 2070 break; 2071 2072 case UDP_ENCAP: 2073 switch (val) { 2074 case 0: 2075 case UDP_ENCAP_ESPINUDP: 2076 case UDP_ENCAP_ESPINUDP_NON_IKE: 2077 up->encap_rcv = xfrm4_udp_encap_rcv; 2078 /* FALLTHROUGH */ 2079 case UDP_ENCAP_L2TPINUDP: 2080 up->encap_type = val; 2081 udp_encap_enable(); 2082 break; 2083 default: 2084 err = -ENOPROTOOPT; 2085 break; 2086 } 2087 break; 2088 2089 case UDP_NO_CHECK6_TX: 2090 up->no_check6_tx = valbool; 2091 break; 2092 2093 case UDP_NO_CHECK6_RX: 2094 up->no_check6_rx = valbool; 2095 break; 2096 2097 /* 2098 * UDP-Lite's partial checksum coverage (RFC 3828). 2099 */ 2100 /* The sender sets actual checksum coverage length via this option. 2101 * The case coverage > packet length is handled by send module. */ 2102 case UDPLITE_SEND_CSCOV: 2103 if (!is_udplite) /* Disable the option on UDP sockets */ 2104 return -ENOPROTOOPT; 2105 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 2106 val = 8; 2107 else if (val > USHRT_MAX) 2108 val = USHRT_MAX; 2109 up->pcslen = val; 2110 up->pcflag |= UDPLITE_SEND_CC; 2111 break; 2112 2113 /* The receiver specifies a minimum checksum coverage value. To make 2114 * sense, this should be set to at least 8 (as done below). If zero is 2115 * used, this again means full checksum coverage. */ 2116 case UDPLITE_RECV_CSCOV: 2117 if (!is_udplite) /* Disable the option on UDP sockets */ 2118 return -ENOPROTOOPT; 2119 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 2120 val = 8; 2121 else if (val > USHRT_MAX) 2122 val = USHRT_MAX; 2123 up->pcrlen = val; 2124 up->pcflag |= UDPLITE_RECV_CC; 2125 break; 2126 2127 default: 2128 err = -ENOPROTOOPT; 2129 break; 2130 } 2131 2132 return err; 2133 } 2134 EXPORT_SYMBOL(udp_lib_setsockopt); 2135 2136 int udp_setsockopt(struct sock *sk, int level, int optname, 2137 char __user *optval, unsigned int optlen) 2138 { 2139 if (level == SOL_UDP || level == SOL_UDPLITE) 2140 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2141 udp_push_pending_frames); 2142 return ip_setsockopt(sk, level, optname, optval, optlen); 2143 } 2144 2145 #ifdef CONFIG_COMPAT 2146 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 2147 char __user *optval, unsigned int optlen) 2148 { 2149 if (level == SOL_UDP || level == SOL_UDPLITE) 2150 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2151 udp_push_pending_frames); 2152 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 2153 } 2154 #endif 2155 2156 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 2157 char __user *optval, int __user *optlen) 2158 { 2159 struct udp_sock *up = udp_sk(sk); 2160 int val, len; 2161 2162 if (get_user(len, optlen)) 2163 return -EFAULT; 2164 2165 len = min_t(unsigned int, len, sizeof(int)); 2166 2167 if (len < 0) 2168 return -EINVAL; 2169 2170 switch (optname) { 2171 case UDP_CORK: 2172 val = up->corkflag; 2173 break; 2174 2175 case UDP_ENCAP: 2176 val = up->encap_type; 2177 break; 2178 2179 case UDP_NO_CHECK6_TX: 2180 val = up->no_check6_tx; 2181 break; 2182 2183 case UDP_NO_CHECK6_RX: 2184 val = up->no_check6_rx; 2185 break; 2186 2187 /* The following two cannot be changed on UDP sockets, the return is 2188 * always 0 (which corresponds to the full checksum coverage of UDP). */ 2189 case UDPLITE_SEND_CSCOV: 2190 val = up->pcslen; 2191 break; 2192 2193 case UDPLITE_RECV_CSCOV: 2194 val = up->pcrlen; 2195 break; 2196 2197 default: 2198 return -ENOPROTOOPT; 2199 } 2200 2201 if (put_user(len, optlen)) 2202 return -EFAULT; 2203 if (copy_to_user(optval, &val, len)) 2204 return -EFAULT; 2205 return 0; 2206 } 2207 EXPORT_SYMBOL(udp_lib_getsockopt); 2208 2209 int udp_getsockopt(struct sock *sk, int level, int optname, 2210 char __user *optval, int __user *optlen) 2211 { 2212 if (level == SOL_UDP || level == SOL_UDPLITE) 2213 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2214 return ip_getsockopt(sk, level, optname, optval, optlen); 2215 } 2216 2217 #ifdef CONFIG_COMPAT 2218 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 2219 char __user *optval, int __user *optlen) 2220 { 2221 if (level == SOL_UDP || level == SOL_UDPLITE) 2222 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2223 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 2224 } 2225 #endif 2226 /** 2227 * udp_poll - wait for a UDP event. 2228 * @file - file struct 2229 * @sock - socket 2230 * @wait - poll table 2231 * 2232 * This is same as datagram poll, except for the special case of 2233 * blocking sockets. If application is using a blocking fd 2234 * and a packet with checksum error is in the queue; 2235 * then it could get return from select indicating data available 2236 * but then block when reading it. Add special case code 2237 * to work around these arguably broken applications. 2238 */ 2239 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 2240 { 2241 unsigned int mask = datagram_poll(file, sock, wait); 2242 struct sock *sk = sock->sk; 2243 2244 sock_rps_record_flow(sk); 2245 2246 /* Check for false positives due to checksum errors */ 2247 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 2248 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk)) 2249 mask &= ~(POLLIN | POLLRDNORM); 2250 2251 return mask; 2252 2253 } 2254 EXPORT_SYMBOL(udp_poll); 2255 2256 struct proto udp_prot = { 2257 .name = "UDP", 2258 .owner = THIS_MODULE, 2259 .close = udp_lib_close, 2260 .connect = ip4_datagram_connect, 2261 .disconnect = udp_disconnect, 2262 .ioctl = udp_ioctl, 2263 .destroy = udp_destroy_sock, 2264 .setsockopt = udp_setsockopt, 2265 .getsockopt = udp_getsockopt, 2266 .sendmsg = udp_sendmsg, 2267 .recvmsg = udp_recvmsg, 2268 .sendpage = udp_sendpage, 2269 .backlog_rcv = __udp_queue_rcv_skb, 2270 .release_cb = ip4_datagram_release_cb, 2271 .hash = udp_lib_hash, 2272 .unhash = udp_lib_unhash, 2273 .rehash = udp_v4_rehash, 2274 .get_port = udp_v4_get_port, 2275 .memory_allocated = &udp_memory_allocated, 2276 .sysctl_mem = sysctl_udp_mem, 2277 .sysctl_wmem = &sysctl_udp_wmem_min, 2278 .sysctl_rmem = &sysctl_udp_rmem_min, 2279 .obj_size = sizeof(struct udp_sock), 2280 .slab_flags = SLAB_DESTROY_BY_RCU, 2281 .h.udp_table = &udp_table, 2282 #ifdef CONFIG_COMPAT 2283 .compat_setsockopt = compat_udp_setsockopt, 2284 .compat_getsockopt = compat_udp_getsockopt, 2285 #endif 2286 .clear_sk = sk_prot_clear_portaddr_nulls, 2287 }; 2288 EXPORT_SYMBOL(udp_prot); 2289 2290 /* ------------------------------------------------------------------------ */ 2291 #ifdef CONFIG_PROC_FS 2292 2293 static struct sock *udp_get_first(struct seq_file *seq, int start) 2294 { 2295 struct sock *sk; 2296 struct udp_iter_state *state = seq->private; 2297 struct net *net = seq_file_net(seq); 2298 2299 for (state->bucket = start; state->bucket <= state->udp_table->mask; 2300 ++state->bucket) { 2301 struct hlist_nulls_node *node; 2302 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; 2303 2304 if (hlist_nulls_empty(&hslot->head)) 2305 continue; 2306 2307 spin_lock_bh(&hslot->lock); 2308 sk_nulls_for_each(sk, node, &hslot->head) { 2309 if (!net_eq(sock_net(sk), net)) 2310 continue; 2311 if (sk->sk_family == state->family) 2312 goto found; 2313 } 2314 spin_unlock_bh(&hslot->lock); 2315 } 2316 sk = NULL; 2317 found: 2318 return sk; 2319 } 2320 2321 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2322 { 2323 struct udp_iter_state *state = seq->private; 2324 struct net *net = seq_file_net(seq); 2325 2326 do { 2327 sk = sk_nulls_next(sk); 2328 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); 2329 2330 if (!sk) { 2331 if (state->bucket <= state->udp_table->mask) 2332 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2333 return udp_get_first(seq, state->bucket + 1); 2334 } 2335 return sk; 2336 } 2337 2338 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2339 { 2340 struct sock *sk = udp_get_first(seq, 0); 2341 2342 if (sk) 2343 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2344 --pos; 2345 return pos ? NULL : sk; 2346 } 2347 2348 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2349 { 2350 struct udp_iter_state *state = seq->private; 2351 state->bucket = MAX_UDP_PORTS; 2352 2353 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2354 } 2355 2356 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2357 { 2358 struct sock *sk; 2359 2360 if (v == SEQ_START_TOKEN) 2361 sk = udp_get_idx(seq, 0); 2362 else 2363 sk = udp_get_next(seq, v); 2364 2365 ++*pos; 2366 return sk; 2367 } 2368 2369 static void udp_seq_stop(struct seq_file *seq, void *v) 2370 { 2371 struct udp_iter_state *state = seq->private; 2372 2373 if (state->bucket <= state->udp_table->mask) 2374 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2375 } 2376 2377 int udp_seq_open(struct inode *inode, struct file *file) 2378 { 2379 struct udp_seq_afinfo *afinfo = PDE_DATA(inode); 2380 struct udp_iter_state *s; 2381 int err; 2382 2383 err = seq_open_net(inode, file, &afinfo->seq_ops, 2384 sizeof(struct udp_iter_state)); 2385 if (err < 0) 2386 return err; 2387 2388 s = ((struct seq_file *)file->private_data)->private; 2389 s->family = afinfo->family; 2390 s->udp_table = afinfo->udp_table; 2391 return err; 2392 } 2393 EXPORT_SYMBOL(udp_seq_open); 2394 2395 /* ------------------------------------------------------------------------ */ 2396 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) 2397 { 2398 struct proc_dir_entry *p; 2399 int rc = 0; 2400 2401 afinfo->seq_ops.start = udp_seq_start; 2402 afinfo->seq_ops.next = udp_seq_next; 2403 afinfo->seq_ops.stop = udp_seq_stop; 2404 2405 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 2406 afinfo->seq_fops, afinfo); 2407 if (!p) 2408 rc = -ENOMEM; 2409 return rc; 2410 } 2411 EXPORT_SYMBOL(udp_proc_register); 2412 2413 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 2414 { 2415 remove_proc_entry(afinfo->name, net->proc_net); 2416 } 2417 EXPORT_SYMBOL(udp_proc_unregister); 2418 2419 /* ------------------------------------------------------------------------ */ 2420 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2421 int bucket) 2422 { 2423 struct inet_sock *inet = inet_sk(sp); 2424 __be32 dest = inet->inet_daddr; 2425 __be32 src = inet->inet_rcv_saddr; 2426 __u16 destp = ntohs(inet->inet_dport); 2427 __u16 srcp = ntohs(inet->inet_sport); 2428 2429 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2430 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 2431 bucket, src, srcp, dest, destp, sp->sk_state, 2432 sk_wmem_alloc_get(sp), 2433 sk_rmem_alloc_get(sp), 2434 0, 0L, 0, 2435 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2436 0, sock_i_ino(sp), 2437 atomic_read(&sp->sk_refcnt), sp, 2438 atomic_read(&sp->sk_drops)); 2439 } 2440 2441 int udp4_seq_show(struct seq_file *seq, void *v) 2442 { 2443 seq_setwidth(seq, 127); 2444 if (v == SEQ_START_TOKEN) 2445 seq_puts(seq, " sl local_address rem_address st tx_queue " 2446 "rx_queue tr tm->when retrnsmt uid timeout " 2447 "inode ref pointer drops"); 2448 else { 2449 struct udp_iter_state *state = seq->private; 2450 2451 udp4_format_sock(v, seq, state->bucket); 2452 } 2453 seq_pad(seq, '\n'); 2454 return 0; 2455 } 2456 2457 static const struct file_operations udp_afinfo_seq_fops = { 2458 .owner = THIS_MODULE, 2459 .open = udp_seq_open, 2460 .read = seq_read, 2461 .llseek = seq_lseek, 2462 .release = seq_release_net 2463 }; 2464 2465 /* ------------------------------------------------------------------------ */ 2466 static struct udp_seq_afinfo udp4_seq_afinfo = { 2467 .name = "udp", 2468 .family = AF_INET, 2469 .udp_table = &udp_table, 2470 .seq_fops = &udp_afinfo_seq_fops, 2471 .seq_ops = { 2472 .show = udp4_seq_show, 2473 }, 2474 }; 2475 2476 static int __net_init udp4_proc_init_net(struct net *net) 2477 { 2478 return udp_proc_register(net, &udp4_seq_afinfo); 2479 } 2480 2481 static void __net_exit udp4_proc_exit_net(struct net *net) 2482 { 2483 udp_proc_unregister(net, &udp4_seq_afinfo); 2484 } 2485 2486 static struct pernet_operations udp4_net_ops = { 2487 .init = udp4_proc_init_net, 2488 .exit = udp4_proc_exit_net, 2489 }; 2490 2491 int __init udp4_proc_init(void) 2492 { 2493 return register_pernet_subsys(&udp4_net_ops); 2494 } 2495 2496 void udp4_proc_exit(void) 2497 { 2498 unregister_pernet_subsys(&udp4_net_ops); 2499 } 2500 #endif /* CONFIG_PROC_FS */ 2501 2502 static __initdata unsigned long uhash_entries; 2503 static int __init set_uhash_entries(char *str) 2504 { 2505 ssize_t ret; 2506 2507 if (!str) 2508 return 0; 2509 2510 ret = kstrtoul(str, 0, &uhash_entries); 2511 if (ret) 2512 return 0; 2513 2514 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2515 uhash_entries = UDP_HTABLE_SIZE_MIN; 2516 return 1; 2517 } 2518 __setup("uhash_entries=", set_uhash_entries); 2519 2520 void __init udp_table_init(struct udp_table *table, const char *name) 2521 { 2522 unsigned int i; 2523 2524 table->hash = alloc_large_system_hash(name, 2525 2 * sizeof(struct udp_hslot), 2526 uhash_entries, 2527 21, /* one slot per 2 MB */ 2528 0, 2529 &table->log, 2530 &table->mask, 2531 UDP_HTABLE_SIZE_MIN, 2532 64 * 1024); 2533 2534 table->hash2 = table->hash + (table->mask + 1); 2535 for (i = 0; i <= table->mask; i++) { 2536 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); 2537 table->hash[i].count = 0; 2538 spin_lock_init(&table->hash[i].lock); 2539 } 2540 for (i = 0; i <= table->mask; i++) { 2541 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); 2542 table->hash2[i].count = 0; 2543 spin_lock_init(&table->hash2[i].lock); 2544 } 2545 } 2546 2547 u32 udp_flow_hashrnd(void) 2548 { 2549 static u32 hashrnd __read_mostly; 2550 2551 net_get_random_once(&hashrnd, sizeof(hashrnd)); 2552 2553 return hashrnd; 2554 } 2555 EXPORT_SYMBOL(udp_flow_hashrnd); 2556 2557 void __init udp_init(void) 2558 { 2559 unsigned long limit; 2560 2561 udp_table_init(&udp_table, "UDP"); 2562 limit = nr_free_buffer_pages() / 8; 2563 limit = max(limit, 128UL); 2564 sysctl_udp_mem[0] = limit / 4 * 3; 2565 sysctl_udp_mem[1] = limit; 2566 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 2567 2568 sysctl_udp_rmem_min = SK_MEM_QUANTUM; 2569 sysctl_udp_wmem_min = SK_MEM_QUANTUM; 2570 } 2571