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/inet_hashtables.h> 107 #include <net/route.h> 108 #include <net/checksum.h> 109 #include <net/xfrm.h> 110 #include <trace/events/udp.h> 111 #include <linux/static_key.h> 112 #include <trace/events/skb.h> 113 #include <net/busy_poll.h> 114 #include "udp_impl.h" 115 116 struct udp_table udp_table __read_mostly; 117 EXPORT_SYMBOL(udp_table); 118 119 long sysctl_udp_mem[3] __read_mostly; 120 EXPORT_SYMBOL(sysctl_udp_mem); 121 122 int sysctl_udp_rmem_min __read_mostly; 123 EXPORT_SYMBOL(sysctl_udp_rmem_min); 124 125 int sysctl_udp_wmem_min __read_mostly; 126 EXPORT_SYMBOL(sysctl_udp_wmem_min); 127 128 atomic_long_t udp_memory_allocated; 129 EXPORT_SYMBOL(udp_memory_allocated); 130 131 #define MAX_UDP_PORTS 65536 132 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 133 134 static int udp_lib_lport_inuse(struct net *net, __u16 num, 135 const struct udp_hslot *hslot, 136 unsigned long *bitmap, 137 struct sock *sk, 138 int (*saddr_comp)(const struct sock *sk1, 139 const struct sock *sk2), 140 unsigned int log) 141 { 142 struct sock *sk2; 143 struct hlist_nulls_node *node; 144 kuid_t uid = sock_i_uid(sk); 145 146 sk_nulls_for_each(sk2, node, &hslot->head) 147 if (net_eq(sock_net(sk2), net) && 148 sk2 != sk && 149 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 150 (!sk2->sk_reuse || !sk->sk_reuse) && 151 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 152 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 153 (!sk2->sk_reuseport || !sk->sk_reuseport || 154 !uid_eq(uid, sock_i_uid(sk2))) && 155 (*saddr_comp)(sk, sk2)) { 156 if (bitmap) 157 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 158 bitmap); 159 else 160 return 1; 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 spin_unlock(&hslot2->lock); 195 return res; 196 } 197 198 /** 199 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 200 * 201 * @sk: socket struct in question 202 * @snum: port number to look up 203 * @saddr_comp: AF-dependent comparison of bound local IP addresses 204 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 205 * with NULL address 206 */ 207 int udp_lib_get_port(struct sock *sk, unsigned short snum, 208 int (*saddr_comp)(const struct sock *sk1, 209 const struct sock *sk2), 210 unsigned int hash2_nulladdr) 211 { 212 struct udp_hslot *hslot, *hslot2; 213 struct udp_table *udptable = sk->sk_prot->h.udp_table; 214 int error = 1; 215 struct net *net = sock_net(sk); 216 217 if (!snum) { 218 int low, high, remaining; 219 unsigned int rand; 220 unsigned short first, last; 221 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 222 223 inet_get_local_port_range(net, &low, &high); 224 remaining = (high - low) + 1; 225 226 rand = prandom_u32(); 227 first = (((u64)rand * remaining) >> 32) + low; 228 /* 229 * force rand to be an odd multiple of UDP_HTABLE_SIZE 230 */ 231 rand = (rand | 1) * (udptable->mask + 1); 232 last = first + udptable->mask + 1; 233 do { 234 hslot = udp_hashslot(udptable, net, first); 235 bitmap_zero(bitmap, PORTS_PER_CHAIN); 236 spin_lock_bh(&hslot->lock); 237 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 238 saddr_comp, udptable->log); 239 240 snum = first; 241 /* 242 * Iterate on all possible values of snum for this hash. 243 * Using steps of an odd multiple of UDP_HTABLE_SIZE 244 * give us randomization and full range coverage. 245 */ 246 do { 247 if (low <= snum && snum <= high && 248 !test_bit(snum >> udptable->log, bitmap) && 249 !inet_is_reserved_local_port(snum)) 250 goto found; 251 snum += rand; 252 } while (snum != first); 253 spin_unlock_bh(&hslot->lock); 254 } while (++first != last); 255 goto fail; 256 } else { 257 hslot = udp_hashslot(udptable, net, snum); 258 spin_lock_bh(&hslot->lock); 259 if (hslot->count > 10) { 260 int exist; 261 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 262 263 slot2 &= udptable->mask; 264 hash2_nulladdr &= udptable->mask; 265 266 hslot2 = udp_hashslot2(udptable, slot2); 267 if (hslot->count < hslot2->count) 268 goto scan_primary_hash; 269 270 exist = udp_lib_lport_inuse2(net, snum, hslot2, 271 sk, saddr_comp); 272 if (!exist && (hash2_nulladdr != slot2)) { 273 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 274 exist = udp_lib_lport_inuse2(net, snum, hslot2, 275 sk, saddr_comp); 276 } 277 if (exist) 278 goto fail_unlock; 279 else 280 goto found; 281 } 282 scan_primary_hash: 283 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 284 saddr_comp, 0)) 285 goto fail_unlock; 286 } 287 found: 288 inet_sk(sk)->inet_num = snum; 289 udp_sk(sk)->udp_port_hash = snum; 290 udp_sk(sk)->udp_portaddr_hash ^= snum; 291 if (sk_unhashed(sk)) { 292 sk_nulls_add_node_rcu(sk, &hslot->head); 293 hslot->count++; 294 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 295 296 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 297 spin_lock(&hslot2->lock); 298 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 299 &hslot2->head); 300 hslot2->count++; 301 spin_unlock(&hslot2->lock); 302 } 303 error = 0; 304 fail_unlock: 305 spin_unlock_bh(&hslot->lock); 306 fail: 307 return error; 308 } 309 EXPORT_SYMBOL(udp_lib_get_port); 310 311 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 312 { 313 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 314 315 return (!ipv6_only_sock(sk2) && 316 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr || 317 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr)); 318 } 319 320 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr, 321 unsigned int port) 322 { 323 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 324 } 325 326 int udp_v4_get_port(struct sock *sk, unsigned short snum) 327 { 328 unsigned int hash2_nulladdr = 329 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 330 unsigned int hash2_partial = 331 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 332 333 /* precompute partial secondary hash */ 334 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 335 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr); 336 } 337 338 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr, 339 unsigned short hnum, 340 __be16 sport, __be32 daddr, __be16 dport, int dif) 341 { 342 int score = -1; 343 344 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && 345 !ipv6_only_sock(sk)) { 346 struct inet_sock *inet = inet_sk(sk); 347 348 score = (sk->sk_family == PF_INET ? 2 : 1); 349 if (inet->inet_rcv_saddr) { 350 if (inet->inet_rcv_saddr != daddr) 351 return -1; 352 score += 4; 353 } 354 if (inet->inet_daddr) { 355 if (inet->inet_daddr != saddr) 356 return -1; 357 score += 4; 358 } 359 if (inet->inet_dport) { 360 if (inet->inet_dport != sport) 361 return -1; 362 score += 4; 363 } 364 if (sk->sk_bound_dev_if) { 365 if (sk->sk_bound_dev_if != dif) 366 return -1; 367 score += 4; 368 } 369 } 370 return score; 371 } 372 373 /* 374 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num) 375 */ 376 static inline int compute_score2(struct sock *sk, struct net *net, 377 __be32 saddr, __be16 sport, 378 __be32 daddr, unsigned int hnum, int dif) 379 { 380 int score = -1; 381 382 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) { 383 struct inet_sock *inet = inet_sk(sk); 384 385 if (inet->inet_rcv_saddr != daddr) 386 return -1; 387 if (inet->inet_num != hnum) 388 return -1; 389 390 score = (sk->sk_family == PF_INET ? 2 : 1); 391 if (inet->inet_daddr) { 392 if (inet->inet_daddr != saddr) 393 return -1; 394 score += 4; 395 } 396 if (inet->inet_dport) { 397 if (inet->inet_dport != sport) 398 return -1; 399 score += 4; 400 } 401 if (sk->sk_bound_dev_if) { 402 if (sk->sk_bound_dev_if != dif) 403 return -1; 404 score += 4; 405 } 406 } 407 return score; 408 } 409 410 static unsigned int udp_ehashfn(struct net *net, const __be32 laddr, 411 const __u16 lport, const __be32 faddr, 412 const __be16 fport) 413 { 414 static u32 udp_ehash_secret __read_mostly; 415 416 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); 417 418 return __inet_ehashfn(laddr, lport, faddr, fport, 419 udp_ehash_secret + net_hash_mix(net)); 420 } 421 422 423 /* called with read_rcu_lock() */ 424 static struct sock *udp4_lib_lookup2(struct net *net, 425 __be32 saddr, __be16 sport, 426 __be32 daddr, unsigned int hnum, int dif, 427 struct udp_hslot *hslot2, unsigned int slot2) 428 { 429 struct sock *sk, *result; 430 struct hlist_nulls_node *node; 431 int score, badness, matches = 0, reuseport = 0; 432 u32 hash = 0; 433 434 begin: 435 result = NULL; 436 badness = 0; 437 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { 438 score = compute_score2(sk, net, saddr, sport, 439 daddr, hnum, dif); 440 if (score > badness) { 441 result = sk; 442 badness = score; 443 reuseport = sk->sk_reuseport; 444 if (reuseport) { 445 hash = udp_ehashfn(net, daddr, hnum, 446 saddr, sport); 447 matches = 1; 448 } 449 } else if (score == badness && reuseport) { 450 matches++; 451 if (((u64)hash * matches) >> 32 == 0) 452 result = sk; 453 hash = next_pseudo_random32(hash); 454 } 455 } 456 /* 457 * if the nulls value we got at the end of this lookup is 458 * not the expected one, we must restart lookup. 459 * We probably met an item that was moved to another chain. 460 */ 461 if (get_nulls_value(node) != slot2) 462 goto begin; 463 if (result) { 464 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 465 result = NULL; 466 else if (unlikely(compute_score2(result, net, saddr, sport, 467 daddr, hnum, dif) < badness)) { 468 sock_put(result); 469 goto begin; 470 } 471 } 472 return result; 473 } 474 475 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 476 * harder than this. -DaveM 477 */ 478 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 479 __be16 sport, __be32 daddr, __be16 dport, 480 int dif, struct udp_table *udptable) 481 { 482 struct sock *sk, *result; 483 struct hlist_nulls_node *node; 484 unsigned short hnum = ntohs(dport); 485 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); 486 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; 487 int score, badness, matches = 0, reuseport = 0; 488 u32 hash = 0; 489 490 rcu_read_lock(); 491 if (hslot->count > 10) { 492 hash2 = udp4_portaddr_hash(net, daddr, hnum); 493 slot2 = hash2 & udptable->mask; 494 hslot2 = &udptable->hash2[slot2]; 495 if (hslot->count < hslot2->count) 496 goto begin; 497 498 result = udp4_lib_lookup2(net, saddr, sport, 499 daddr, hnum, dif, 500 hslot2, slot2); 501 if (!result) { 502 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 503 slot2 = hash2 & udptable->mask; 504 hslot2 = &udptable->hash2[slot2]; 505 if (hslot->count < hslot2->count) 506 goto begin; 507 508 result = udp4_lib_lookup2(net, saddr, sport, 509 htonl(INADDR_ANY), hnum, dif, 510 hslot2, slot2); 511 } 512 rcu_read_unlock(); 513 return result; 514 } 515 begin: 516 result = NULL; 517 badness = 0; 518 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 519 score = compute_score(sk, net, saddr, hnum, sport, 520 daddr, dport, dif); 521 if (score > badness) { 522 result = sk; 523 badness = score; 524 reuseport = sk->sk_reuseport; 525 if (reuseport) { 526 hash = udp_ehashfn(net, daddr, hnum, 527 saddr, sport); 528 matches = 1; 529 } 530 } else if (score == badness && reuseport) { 531 matches++; 532 if (((u64)hash * matches) >> 32 == 0) 533 result = sk; 534 hash = next_pseudo_random32(hash); 535 } 536 } 537 /* 538 * if the nulls value we got at the end of this lookup is 539 * not the expected one, we must restart lookup. 540 * We probably met an item that was moved to another chain. 541 */ 542 if (get_nulls_value(node) != slot) 543 goto begin; 544 545 if (result) { 546 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 547 result = NULL; 548 else if (unlikely(compute_score(result, net, saddr, hnum, sport, 549 daddr, dport, dif) < badness)) { 550 sock_put(result); 551 goto begin; 552 } 553 } 554 rcu_read_unlock(); 555 return result; 556 } 557 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 558 559 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 560 __be16 sport, __be16 dport, 561 struct udp_table *udptable) 562 { 563 const struct iphdr *iph = ip_hdr(skb); 564 565 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, 566 iph->daddr, dport, inet_iif(skb), 567 udptable); 568 } 569 570 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 571 __be32 daddr, __be16 dport, int dif) 572 { 573 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); 574 } 575 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 576 577 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, 578 __be16 loc_port, __be32 loc_addr, 579 __be16 rmt_port, __be32 rmt_addr, 580 int dif, unsigned short hnum) 581 { 582 struct inet_sock *inet = inet_sk(sk); 583 584 if (!net_eq(sock_net(sk), net) || 585 udp_sk(sk)->udp_port_hash != hnum || 586 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 587 (inet->inet_dport != rmt_port && inet->inet_dport) || 588 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) || 589 ipv6_only_sock(sk) || 590 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) 591 return false; 592 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif)) 593 return false; 594 return true; 595 } 596 597 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk, 598 __be16 loc_port, __be32 loc_addr, 599 __be16 rmt_port, __be32 rmt_addr, 600 int dif) 601 { 602 struct hlist_nulls_node *node; 603 struct sock *s = sk; 604 unsigned short hnum = ntohs(loc_port); 605 606 sk_nulls_for_each_from(s, node) { 607 if (__udp_is_mcast_sock(net, s, 608 loc_port, loc_addr, 609 rmt_port, rmt_addr, 610 dif, hnum)) 611 goto found; 612 } 613 s = NULL; 614 found: 615 return s; 616 } 617 618 /* 619 * This routine is called by the ICMP module when it gets some 620 * sort of error condition. If err < 0 then the socket should 621 * be closed and the error returned to the user. If err > 0 622 * it's just the icmp type << 8 | icmp code. 623 * Header points to the ip header of the error packet. We move 624 * on past this. Then (as it used to claim before adjustment) 625 * header points to the first 8 bytes of the udp header. We need 626 * to find the appropriate port. 627 */ 628 629 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 630 { 631 struct inet_sock *inet; 632 const struct iphdr *iph = (const struct iphdr *)skb->data; 633 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 634 const int type = icmp_hdr(skb)->type; 635 const int code = icmp_hdr(skb)->code; 636 struct sock *sk; 637 int harderr; 638 int err; 639 struct net *net = dev_net(skb->dev); 640 641 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 642 iph->saddr, uh->source, skb->dev->ifindex, udptable); 643 if (sk == NULL) { 644 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 645 return; /* No socket for error */ 646 } 647 648 err = 0; 649 harderr = 0; 650 inet = inet_sk(sk); 651 652 switch (type) { 653 default: 654 case ICMP_TIME_EXCEEDED: 655 err = EHOSTUNREACH; 656 break; 657 case ICMP_SOURCE_QUENCH: 658 goto out; 659 case ICMP_PARAMETERPROB: 660 err = EPROTO; 661 harderr = 1; 662 break; 663 case ICMP_DEST_UNREACH: 664 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 665 ipv4_sk_update_pmtu(skb, sk, info); 666 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 667 err = EMSGSIZE; 668 harderr = 1; 669 break; 670 } 671 goto out; 672 } 673 err = EHOSTUNREACH; 674 if (code <= NR_ICMP_UNREACH) { 675 harderr = icmp_err_convert[code].fatal; 676 err = icmp_err_convert[code].errno; 677 } 678 break; 679 case ICMP_REDIRECT: 680 ipv4_sk_redirect(skb, sk); 681 goto out; 682 } 683 684 /* 685 * RFC1122: OK. Passes ICMP errors back to application, as per 686 * 4.1.3.3. 687 */ 688 if (!inet->recverr) { 689 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 690 goto out; 691 } else 692 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 693 694 sk->sk_err = err; 695 sk->sk_error_report(sk); 696 out: 697 sock_put(sk); 698 } 699 700 void udp_err(struct sk_buff *skb, u32 info) 701 { 702 __udp4_lib_err(skb, info, &udp_table); 703 } 704 705 /* 706 * Throw away all pending data and cancel the corking. Socket is locked. 707 */ 708 void udp_flush_pending_frames(struct sock *sk) 709 { 710 struct udp_sock *up = udp_sk(sk); 711 712 if (up->pending) { 713 up->len = 0; 714 up->pending = 0; 715 ip_flush_pending_frames(sk); 716 } 717 } 718 EXPORT_SYMBOL(udp_flush_pending_frames); 719 720 /** 721 * udp4_hwcsum - handle outgoing HW checksumming 722 * @skb: sk_buff containing the filled-in UDP header 723 * (checksum field must be zeroed out) 724 * @src: source IP address 725 * @dst: destination IP address 726 */ 727 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 728 { 729 struct udphdr *uh = udp_hdr(skb); 730 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 731 int offset = skb_transport_offset(skb); 732 int len = skb->len - offset; 733 int hlen = len; 734 __wsum csum = 0; 735 736 if (!frags) { 737 /* 738 * Only one fragment on the socket. 739 */ 740 skb->csum_start = skb_transport_header(skb) - skb->head; 741 skb->csum_offset = offsetof(struct udphdr, check); 742 uh->check = ~csum_tcpudp_magic(src, dst, len, 743 IPPROTO_UDP, 0); 744 } else { 745 /* 746 * HW-checksum won't work as there are two or more 747 * fragments on the socket so that all csums of sk_buffs 748 * should be together 749 */ 750 do { 751 csum = csum_add(csum, frags->csum); 752 hlen -= frags->len; 753 } while ((frags = frags->next)); 754 755 csum = skb_checksum(skb, offset, hlen, csum); 756 skb->ip_summed = CHECKSUM_NONE; 757 758 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 759 if (uh->check == 0) 760 uh->check = CSUM_MANGLED_0; 761 } 762 } 763 EXPORT_SYMBOL_GPL(udp4_hwcsum); 764 765 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) 766 { 767 struct sock *sk = skb->sk; 768 struct inet_sock *inet = inet_sk(sk); 769 struct udphdr *uh; 770 int err = 0; 771 int is_udplite = IS_UDPLITE(sk); 772 int offset = skb_transport_offset(skb); 773 int len = skb->len - offset; 774 __wsum csum = 0; 775 776 /* 777 * Create a UDP header 778 */ 779 uh = udp_hdr(skb); 780 uh->source = inet->inet_sport; 781 uh->dest = fl4->fl4_dport; 782 uh->len = htons(len); 783 uh->check = 0; 784 785 if (is_udplite) /* UDP-Lite */ 786 csum = udplite_csum(skb); 787 788 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ 789 790 skb->ip_summed = CHECKSUM_NONE; 791 goto send; 792 793 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 794 795 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 796 goto send; 797 798 } else 799 csum = udp_csum(skb); 800 801 /* add protocol-dependent pseudo-header */ 802 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 803 sk->sk_protocol, csum); 804 if (uh->check == 0) 805 uh->check = CSUM_MANGLED_0; 806 807 send: 808 err = ip_send_skb(sock_net(sk), skb); 809 if (err) { 810 if (err == -ENOBUFS && !inet->recverr) { 811 UDP_INC_STATS_USER(sock_net(sk), 812 UDP_MIB_SNDBUFERRORS, is_udplite); 813 err = 0; 814 } 815 } else 816 UDP_INC_STATS_USER(sock_net(sk), 817 UDP_MIB_OUTDATAGRAMS, is_udplite); 818 return err; 819 } 820 821 /* 822 * Push out all pending data as one UDP datagram. Socket is locked. 823 */ 824 int udp_push_pending_frames(struct sock *sk) 825 { 826 struct udp_sock *up = udp_sk(sk); 827 struct inet_sock *inet = inet_sk(sk); 828 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 829 struct sk_buff *skb; 830 int err = 0; 831 832 skb = ip_finish_skb(sk, fl4); 833 if (!skb) 834 goto out; 835 836 err = udp_send_skb(skb, fl4); 837 838 out: 839 up->len = 0; 840 up->pending = 0; 841 return err; 842 } 843 EXPORT_SYMBOL(udp_push_pending_frames); 844 845 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 846 size_t len) 847 { 848 struct inet_sock *inet = inet_sk(sk); 849 struct udp_sock *up = udp_sk(sk); 850 struct flowi4 fl4_stack; 851 struct flowi4 *fl4; 852 int ulen = len; 853 struct ipcm_cookie ipc; 854 struct rtable *rt = NULL; 855 int free = 0; 856 int connected = 0; 857 __be32 daddr, faddr, saddr; 858 __be16 dport; 859 u8 tos; 860 int err, is_udplite = IS_UDPLITE(sk); 861 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 862 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 863 struct sk_buff *skb; 864 struct ip_options_data opt_copy; 865 866 if (len > 0xFFFF) 867 return -EMSGSIZE; 868 869 /* 870 * Check the flags. 871 */ 872 873 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 874 return -EOPNOTSUPP; 875 876 ipc.opt = NULL; 877 ipc.tx_flags = 0; 878 ipc.ttl = 0; 879 ipc.tos = -1; 880 881 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 882 883 fl4 = &inet->cork.fl.u.ip4; 884 if (up->pending) { 885 /* 886 * There are pending frames. 887 * The socket lock must be held while it's corked. 888 */ 889 lock_sock(sk); 890 if (likely(up->pending)) { 891 if (unlikely(up->pending != AF_INET)) { 892 release_sock(sk); 893 return -EINVAL; 894 } 895 goto do_append_data; 896 } 897 release_sock(sk); 898 } 899 ulen += sizeof(struct udphdr); 900 901 /* 902 * Get and verify the address. 903 */ 904 if (msg->msg_name) { 905 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 906 if (msg->msg_namelen < sizeof(*usin)) 907 return -EINVAL; 908 if (usin->sin_family != AF_INET) { 909 if (usin->sin_family != AF_UNSPEC) 910 return -EAFNOSUPPORT; 911 } 912 913 daddr = usin->sin_addr.s_addr; 914 dport = usin->sin_port; 915 if (dport == 0) 916 return -EINVAL; 917 } else { 918 if (sk->sk_state != TCP_ESTABLISHED) 919 return -EDESTADDRREQ; 920 daddr = inet->inet_daddr; 921 dport = inet->inet_dport; 922 /* Open fast path for connected socket. 923 Route will not be used, if at least one option is set. 924 */ 925 connected = 1; 926 } 927 ipc.addr = inet->inet_saddr; 928 929 ipc.oif = sk->sk_bound_dev_if; 930 931 sock_tx_timestamp(sk, &ipc.tx_flags); 932 933 if (msg->msg_controllen) { 934 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 935 if (err) 936 return err; 937 if (ipc.opt) 938 free = 1; 939 connected = 0; 940 } 941 if (!ipc.opt) { 942 struct ip_options_rcu *inet_opt; 943 944 rcu_read_lock(); 945 inet_opt = rcu_dereference(inet->inet_opt); 946 if (inet_opt) { 947 memcpy(&opt_copy, inet_opt, 948 sizeof(*inet_opt) + inet_opt->opt.optlen); 949 ipc.opt = &opt_copy.opt; 950 } 951 rcu_read_unlock(); 952 } 953 954 saddr = ipc.addr; 955 ipc.addr = faddr = daddr; 956 957 if (ipc.opt && ipc.opt->opt.srr) { 958 if (!daddr) 959 return -EINVAL; 960 faddr = ipc.opt->opt.faddr; 961 connected = 0; 962 } 963 tos = get_rttos(&ipc, inet); 964 if (sock_flag(sk, SOCK_LOCALROUTE) || 965 (msg->msg_flags & MSG_DONTROUTE) || 966 (ipc.opt && ipc.opt->opt.is_strictroute)) { 967 tos |= RTO_ONLINK; 968 connected = 0; 969 } 970 971 if (ipv4_is_multicast(daddr)) { 972 if (!ipc.oif) 973 ipc.oif = inet->mc_index; 974 if (!saddr) 975 saddr = inet->mc_addr; 976 connected = 0; 977 } else if (!ipc.oif) 978 ipc.oif = inet->uc_index; 979 980 if (connected) 981 rt = (struct rtable *)sk_dst_check(sk, 0); 982 983 if (rt == NULL) { 984 struct net *net = sock_net(sk); 985 986 fl4 = &fl4_stack; 987 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, 988 RT_SCOPE_UNIVERSE, sk->sk_protocol, 989 inet_sk_flowi_flags(sk), 990 faddr, saddr, dport, inet->inet_sport); 991 992 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 993 rt = ip_route_output_flow(net, fl4, sk); 994 if (IS_ERR(rt)) { 995 err = PTR_ERR(rt); 996 rt = NULL; 997 if (err == -ENETUNREACH) 998 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 999 goto out; 1000 } 1001 1002 err = -EACCES; 1003 if ((rt->rt_flags & RTCF_BROADCAST) && 1004 !sock_flag(sk, SOCK_BROADCAST)) 1005 goto out; 1006 if (connected) 1007 sk_dst_set(sk, dst_clone(&rt->dst)); 1008 } 1009 1010 if (msg->msg_flags&MSG_CONFIRM) 1011 goto do_confirm; 1012 back_from_confirm: 1013 1014 saddr = fl4->saddr; 1015 if (!ipc.addr) 1016 daddr = ipc.addr = fl4->daddr; 1017 1018 /* Lockless fast path for the non-corking case. */ 1019 if (!corkreq) { 1020 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen, 1021 sizeof(struct udphdr), &ipc, &rt, 1022 msg->msg_flags); 1023 err = PTR_ERR(skb); 1024 if (!IS_ERR_OR_NULL(skb)) 1025 err = udp_send_skb(skb, fl4); 1026 goto out; 1027 } 1028 1029 lock_sock(sk); 1030 if (unlikely(up->pending)) { 1031 /* The socket is already corked while preparing it. */ 1032 /* ... which is an evident application bug. --ANK */ 1033 release_sock(sk); 1034 1035 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n")); 1036 err = -EINVAL; 1037 goto out; 1038 } 1039 /* 1040 * Now cork the socket to pend data. 1041 */ 1042 fl4 = &inet->cork.fl.u.ip4; 1043 fl4->daddr = daddr; 1044 fl4->saddr = saddr; 1045 fl4->fl4_dport = dport; 1046 fl4->fl4_sport = inet->inet_sport; 1047 up->pending = AF_INET; 1048 1049 do_append_data: 1050 up->len += ulen; 1051 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen, 1052 sizeof(struct udphdr), &ipc, &rt, 1053 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1054 if (err) 1055 udp_flush_pending_frames(sk); 1056 else if (!corkreq) 1057 err = udp_push_pending_frames(sk); 1058 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1059 up->pending = 0; 1060 release_sock(sk); 1061 1062 out: 1063 ip_rt_put(rt); 1064 if (free) 1065 kfree(ipc.opt); 1066 if (!err) 1067 return len; 1068 /* 1069 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1070 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1071 * we don't have a good statistic (IpOutDiscards but it can be too many 1072 * things). We could add another new stat but at least for now that 1073 * seems like overkill. 1074 */ 1075 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1076 UDP_INC_STATS_USER(sock_net(sk), 1077 UDP_MIB_SNDBUFERRORS, is_udplite); 1078 } 1079 return err; 1080 1081 do_confirm: 1082 dst_confirm(&rt->dst); 1083 if (!(msg->msg_flags&MSG_PROBE) || len) 1084 goto back_from_confirm; 1085 err = 0; 1086 goto out; 1087 } 1088 EXPORT_SYMBOL(udp_sendmsg); 1089 1090 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1091 size_t size, int flags) 1092 { 1093 struct inet_sock *inet = inet_sk(sk); 1094 struct udp_sock *up = udp_sk(sk); 1095 int ret; 1096 1097 if (flags & MSG_SENDPAGE_NOTLAST) 1098 flags |= MSG_MORE; 1099 1100 if (!up->pending) { 1101 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1102 1103 /* Call udp_sendmsg to specify destination address which 1104 * sendpage interface can't pass. 1105 * This will succeed only when the socket is connected. 1106 */ 1107 ret = udp_sendmsg(NULL, sk, &msg, 0); 1108 if (ret < 0) 1109 return ret; 1110 } 1111 1112 lock_sock(sk); 1113 1114 if (unlikely(!up->pending)) { 1115 release_sock(sk); 1116 1117 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n")); 1118 return -EINVAL; 1119 } 1120 1121 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1122 page, offset, size, flags); 1123 if (ret == -EOPNOTSUPP) { 1124 release_sock(sk); 1125 return sock_no_sendpage(sk->sk_socket, page, offset, 1126 size, flags); 1127 } 1128 if (ret < 0) { 1129 udp_flush_pending_frames(sk); 1130 goto out; 1131 } 1132 1133 up->len += size; 1134 if (!(up->corkflag || (flags&MSG_MORE))) 1135 ret = udp_push_pending_frames(sk); 1136 if (!ret) 1137 ret = size; 1138 out: 1139 release_sock(sk); 1140 return ret; 1141 } 1142 1143 1144 /** 1145 * first_packet_length - return length of first packet in receive queue 1146 * @sk: socket 1147 * 1148 * Drops all bad checksum frames, until a valid one is found. 1149 * Returns the length of found skb, or 0 if none is found. 1150 */ 1151 static unsigned int first_packet_length(struct sock *sk) 1152 { 1153 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue; 1154 struct sk_buff *skb; 1155 unsigned int res; 1156 1157 __skb_queue_head_init(&list_kill); 1158 1159 spin_lock_bh(&rcvq->lock); 1160 while ((skb = skb_peek(rcvq)) != NULL && 1161 udp_lib_checksum_complete(skb)) { 1162 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, 1163 IS_UDPLITE(sk)); 1164 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1165 IS_UDPLITE(sk)); 1166 atomic_inc(&sk->sk_drops); 1167 __skb_unlink(skb, rcvq); 1168 __skb_queue_tail(&list_kill, skb); 1169 } 1170 res = skb ? skb->len : 0; 1171 spin_unlock_bh(&rcvq->lock); 1172 1173 if (!skb_queue_empty(&list_kill)) { 1174 bool slow = lock_sock_fast(sk); 1175 1176 __skb_queue_purge(&list_kill); 1177 sk_mem_reclaim_partial(sk); 1178 unlock_sock_fast(sk, slow); 1179 } 1180 return res; 1181 } 1182 1183 /* 1184 * IOCTL requests applicable to the UDP protocol 1185 */ 1186 1187 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1188 { 1189 switch (cmd) { 1190 case SIOCOUTQ: 1191 { 1192 int amount = sk_wmem_alloc_get(sk); 1193 1194 return put_user(amount, (int __user *)arg); 1195 } 1196 1197 case SIOCINQ: 1198 { 1199 unsigned int amount = first_packet_length(sk); 1200 1201 if (amount) 1202 /* 1203 * We will only return the amount 1204 * of this packet since that is all 1205 * that will be read. 1206 */ 1207 amount -= sizeof(struct udphdr); 1208 1209 return put_user(amount, (int __user *)arg); 1210 } 1211 1212 default: 1213 return -ENOIOCTLCMD; 1214 } 1215 1216 return 0; 1217 } 1218 EXPORT_SYMBOL(udp_ioctl); 1219 1220 /* 1221 * This should be easy, if there is something there we 1222 * return it, otherwise we block. 1223 */ 1224 1225 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1226 size_t len, int noblock, int flags, int *addr_len) 1227 { 1228 struct inet_sock *inet = inet_sk(sk); 1229 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 1230 struct sk_buff *skb; 1231 unsigned int ulen, copied; 1232 int peeked, off = 0; 1233 int err; 1234 int is_udplite = IS_UDPLITE(sk); 1235 bool slow; 1236 1237 if (flags & MSG_ERRQUEUE) 1238 return ip_recv_error(sk, msg, len, addr_len); 1239 1240 try_again: 1241 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), 1242 &peeked, &off, &err); 1243 if (!skb) 1244 goto out; 1245 1246 ulen = skb->len - sizeof(struct udphdr); 1247 copied = len; 1248 if (copied > ulen) 1249 copied = ulen; 1250 else if (copied < ulen) 1251 msg->msg_flags |= MSG_TRUNC; 1252 1253 /* 1254 * If checksum is needed at all, try to do it while copying the 1255 * data. If the data is truncated, or if we only want a partial 1256 * coverage checksum (UDP-Lite), do it before the copy. 1257 */ 1258 1259 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { 1260 if (udp_lib_checksum_complete(skb)) 1261 goto csum_copy_err; 1262 } 1263 1264 if (skb_csum_unnecessary(skb)) 1265 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), 1266 msg->msg_iov, copied); 1267 else { 1268 err = skb_copy_and_csum_datagram_iovec(skb, 1269 sizeof(struct udphdr), 1270 msg->msg_iov); 1271 1272 if (err == -EINVAL) 1273 goto csum_copy_err; 1274 } 1275 1276 if (unlikely(err)) { 1277 trace_kfree_skb(skb, udp_recvmsg); 1278 if (!peeked) { 1279 atomic_inc(&sk->sk_drops); 1280 UDP_INC_STATS_USER(sock_net(sk), 1281 UDP_MIB_INERRORS, is_udplite); 1282 } 1283 goto out_free; 1284 } 1285 1286 if (!peeked) 1287 UDP_INC_STATS_USER(sock_net(sk), 1288 UDP_MIB_INDATAGRAMS, is_udplite); 1289 1290 sock_recv_ts_and_drops(msg, sk, skb); 1291 1292 /* Copy the address. */ 1293 if (sin) { 1294 sin->sin_family = AF_INET; 1295 sin->sin_port = udp_hdr(skb)->source; 1296 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1297 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1298 *addr_len = sizeof(*sin); 1299 } 1300 if (inet->cmsg_flags) 1301 ip_cmsg_recv(msg, skb); 1302 1303 err = copied; 1304 if (flags & MSG_TRUNC) 1305 err = ulen; 1306 1307 out_free: 1308 skb_free_datagram_locked(sk, skb); 1309 out: 1310 return err; 1311 1312 csum_copy_err: 1313 slow = lock_sock_fast(sk); 1314 if (!skb_kill_datagram(sk, skb, flags)) { 1315 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1316 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1317 } 1318 unlock_sock_fast(sk, slow); 1319 1320 if (noblock) 1321 return -EAGAIN; 1322 1323 /* starting over for a new packet */ 1324 msg->msg_flags &= ~MSG_TRUNC; 1325 goto try_again; 1326 } 1327 1328 1329 int udp_disconnect(struct sock *sk, int flags) 1330 { 1331 struct inet_sock *inet = inet_sk(sk); 1332 /* 1333 * 1003.1g - break association. 1334 */ 1335 1336 sk->sk_state = TCP_CLOSE; 1337 inet->inet_daddr = 0; 1338 inet->inet_dport = 0; 1339 sock_rps_reset_rxhash(sk); 1340 sk->sk_bound_dev_if = 0; 1341 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1342 inet_reset_saddr(sk); 1343 1344 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1345 sk->sk_prot->unhash(sk); 1346 inet->inet_sport = 0; 1347 } 1348 sk_dst_reset(sk); 1349 return 0; 1350 } 1351 EXPORT_SYMBOL(udp_disconnect); 1352 1353 void udp_lib_unhash(struct sock *sk) 1354 { 1355 if (sk_hashed(sk)) { 1356 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1357 struct udp_hslot *hslot, *hslot2; 1358 1359 hslot = udp_hashslot(udptable, sock_net(sk), 1360 udp_sk(sk)->udp_port_hash); 1361 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1362 1363 spin_lock_bh(&hslot->lock); 1364 if (sk_nulls_del_node_init_rcu(sk)) { 1365 hslot->count--; 1366 inet_sk(sk)->inet_num = 0; 1367 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1368 1369 spin_lock(&hslot2->lock); 1370 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1371 hslot2->count--; 1372 spin_unlock(&hslot2->lock); 1373 } 1374 spin_unlock_bh(&hslot->lock); 1375 } 1376 } 1377 EXPORT_SYMBOL(udp_lib_unhash); 1378 1379 /* 1380 * inet_rcv_saddr was changed, we must rehash secondary hash 1381 */ 1382 void udp_lib_rehash(struct sock *sk, u16 newhash) 1383 { 1384 if (sk_hashed(sk)) { 1385 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1386 struct udp_hslot *hslot, *hslot2, *nhslot2; 1387 1388 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1389 nhslot2 = udp_hashslot2(udptable, newhash); 1390 udp_sk(sk)->udp_portaddr_hash = newhash; 1391 if (hslot2 != nhslot2) { 1392 hslot = udp_hashslot(udptable, sock_net(sk), 1393 udp_sk(sk)->udp_port_hash); 1394 /* we must lock primary chain too */ 1395 spin_lock_bh(&hslot->lock); 1396 1397 spin_lock(&hslot2->lock); 1398 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1399 hslot2->count--; 1400 spin_unlock(&hslot2->lock); 1401 1402 spin_lock(&nhslot2->lock); 1403 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1404 &nhslot2->head); 1405 nhslot2->count++; 1406 spin_unlock(&nhslot2->lock); 1407 1408 spin_unlock_bh(&hslot->lock); 1409 } 1410 } 1411 } 1412 EXPORT_SYMBOL(udp_lib_rehash); 1413 1414 static void udp_v4_rehash(struct sock *sk) 1415 { 1416 u16 new_hash = udp4_portaddr_hash(sock_net(sk), 1417 inet_sk(sk)->inet_rcv_saddr, 1418 inet_sk(sk)->inet_num); 1419 udp_lib_rehash(sk, new_hash); 1420 } 1421 1422 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1423 { 1424 int rc; 1425 1426 if (inet_sk(sk)->inet_daddr) { 1427 sock_rps_save_rxhash(sk, skb); 1428 sk_mark_napi_id(sk, skb); 1429 } 1430 1431 rc = sock_queue_rcv_skb(sk, skb); 1432 if (rc < 0) { 1433 int is_udplite = IS_UDPLITE(sk); 1434 1435 /* Note that an ENOMEM error is charged twice */ 1436 if (rc == -ENOMEM) 1437 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1438 is_udplite); 1439 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1440 kfree_skb(skb); 1441 trace_udp_fail_queue_rcv_skb(rc, sk); 1442 return -1; 1443 } 1444 1445 return 0; 1446 1447 } 1448 1449 static struct static_key udp_encap_needed __read_mostly; 1450 void udp_encap_enable(void) 1451 { 1452 if (!static_key_enabled(&udp_encap_needed)) 1453 static_key_slow_inc(&udp_encap_needed); 1454 } 1455 EXPORT_SYMBOL(udp_encap_enable); 1456 1457 /* returns: 1458 * -1: error 1459 * 0: success 1460 * >0: "udp encap" protocol resubmission 1461 * 1462 * Note that in the success and error cases, the skb is assumed to 1463 * have either been requeued or freed. 1464 */ 1465 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1466 { 1467 struct udp_sock *up = udp_sk(sk); 1468 int rc; 1469 int is_udplite = IS_UDPLITE(sk); 1470 1471 /* 1472 * Charge it to the socket, dropping if the queue is full. 1473 */ 1474 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1475 goto drop; 1476 nf_reset(skb); 1477 1478 if (static_key_false(&udp_encap_needed) && up->encap_type) { 1479 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 1480 1481 /* 1482 * This is an encapsulation socket so pass the skb to 1483 * the socket's udp_encap_rcv() hook. Otherwise, just 1484 * fall through and pass this up the UDP socket. 1485 * up->encap_rcv() returns the following value: 1486 * =0 if skb was successfully passed to the encap 1487 * handler or was discarded by it. 1488 * >0 if skb should be passed on to UDP. 1489 * <0 if skb should be resubmitted as proto -N 1490 */ 1491 1492 /* if we're overly short, let UDP handle it */ 1493 encap_rcv = ACCESS_ONCE(up->encap_rcv); 1494 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) { 1495 int ret; 1496 1497 ret = encap_rcv(sk, skb); 1498 if (ret <= 0) { 1499 UDP_INC_STATS_BH(sock_net(sk), 1500 UDP_MIB_INDATAGRAMS, 1501 is_udplite); 1502 return -ret; 1503 } 1504 } 1505 1506 /* FALLTHROUGH -- it's a UDP Packet */ 1507 } 1508 1509 /* 1510 * UDP-Lite specific tests, ignored on UDP sockets 1511 */ 1512 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1513 1514 /* 1515 * MIB statistics other than incrementing the error count are 1516 * disabled for the following two types of errors: these depend 1517 * on the application settings, not on the functioning of the 1518 * protocol stack as such. 1519 * 1520 * RFC 3828 here recommends (sec 3.3): "There should also be a 1521 * way ... to ... at least let the receiving application block 1522 * delivery of packets with coverage values less than a value 1523 * provided by the application." 1524 */ 1525 if (up->pcrlen == 0) { /* full coverage was set */ 1526 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n", 1527 UDP_SKB_CB(skb)->cscov, skb->len); 1528 goto drop; 1529 } 1530 /* The next case involves violating the min. coverage requested 1531 * by the receiver. This is subtle: if receiver wants x and x is 1532 * greater than the buffersize/MTU then receiver will complain 1533 * that it wants x while sender emits packets of smaller size y. 1534 * Therefore the above ...()->partial_cov statement is essential. 1535 */ 1536 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1537 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n", 1538 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1539 goto drop; 1540 } 1541 } 1542 1543 if (rcu_access_pointer(sk->sk_filter) && 1544 udp_lib_checksum_complete(skb)) 1545 goto csum_error; 1546 1547 1548 if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) 1549 goto drop; 1550 1551 rc = 0; 1552 1553 ipv4_pktinfo_prepare(sk, skb); 1554 bh_lock_sock(sk); 1555 if (!sock_owned_by_user(sk)) 1556 rc = __udp_queue_rcv_skb(sk, skb); 1557 else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) { 1558 bh_unlock_sock(sk); 1559 goto drop; 1560 } 1561 bh_unlock_sock(sk); 1562 1563 return rc; 1564 1565 csum_error: 1566 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1567 drop: 1568 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1569 atomic_inc(&sk->sk_drops); 1570 kfree_skb(skb); 1571 return -1; 1572 } 1573 1574 1575 static void flush_stack(struct sock **stack, unsigned int count, 1576 struct sk_buff *skb, unsigned int final) 1577 { 1578 unsigned int i; 1579 struct sk_buff *skb1 = NULL; 1580 struct sock *sk; 1581 1582 for (i = 0; i < count; i++) { 1583 sk = stack[i]; 1584 if (likely(skb1 == NULL)) 1585 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); 1586 1587 if (!skb1) { 1588 atomic_inc(&sk->sk_drops); 1589 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1590 IS_UDPLITE(sk)); 1591 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1592 IS_UDPLITE(sk)); 1593 } 1594 1595 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0) 1596 skb1 = NULL; 1597 } 1598 if (unlikely(skb1)) 1599 kfree_skb(skb1); 1600 } 1601 1602 /* For TCP sockets, sk_rx_dst is protected by socket lock 1603 * For UDP, we use xchg() to guard against concurrent changes. 1604 */ 1605 static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 1606 { 1607 struct dst_entry *old; 1608 1609 dst_hold(dst); 1610 old = xchg(&sk->sk_rx_dst, dst); 1611 dst_release(old); 1612 } 1613 1614 /* 1615 * Multicasts and broadcasts go to each listener. 1616 * 1617 * Note: called only from the BH handler context. 1618 */ 1619 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 1620 struct udphdr *uh, 1621 __be32 saddr, __be32 daddr, 1622 struct udp_table *udptable) 1623 { 1624 struct sock *sk, *stack[256 / sizeof(struct sock *)]; 1625 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest)); 1626 int dif; 1627 unsigned int i, count = 0; 1628 1629 spin_lock(&hslot->lock); 1630 sk = sk_nulls_head(&hslot->head); 1631 dif = skb->dev->ifindex; 1632 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); 1633 while (sk) { 1634 stack[count++] = sk; 1635 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest, 1636 daddr, uh->source, saddr, dif); 1637 if (unlikely(count == ARRAY_SIZE(stack))) { 1638 if (!sk) 1639 break; 1640 flush_stack(stack, count, skb, ~0); 1641 count = 0; 1642 } 1643 } 1644 /* 1645 * before releasing chain lock, we must take a reference on sockets 1646 */ 1647 for (i = 0; i < count; i++) 1648 sock_hold(stack[i]); 1649 1650 spin_unlock(&hslot->lock); 1651 1652 /* 1653 * do the slow work with no lock held 1654 */ 1655 if (count) { 1656 flush_stack(stack, count, skb, count - 1); 1657 1658 for (i = 0; i < count; i++) 1659 sock_put(stack[i]); 1660 } else { 1661 kfree_skb(skb); 1662 } 1663 return 0; 1664 } 1665 1666 /* Initialize UDP checksum. If exited with zero value (success), 1667 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1668 * Otherwise, csum completion requires chacksumming packet body, 1669 * including udp header and folding it to skb->csum. 1670 */ 1671 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 1672 int proto) 1673 { 1674 const struct iphdr *iph; 1675 int err; 1676 1677 UDP_SKB_CB(skb)->partial_cov = 0; 1678 UDP_SKB_CB(skb)->cscov = skb->len; 1679 1680 if (proto == IPPROTO_UDPLITE) { 1681 err = udplite_checksum_init(skb, uh); 1682 if (err) 1683 return err; 1684 } 1685 1686 iph = ip_hdr(skb); 1687 if (uh->check == 0) { 1688 skb->ip_summed = CHECKSUM_UNNECESSARY; 1689 } else if (skb->ip_summed == CHECKSUM_COMPLETE) { 1690 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 1691 proto, skb->csum)) 1692 skb->ip_summed = CHECKSUM_UNNECESSARY; 1693 } 1694 if (!skb_csum_unnecessary(skb)) 1695 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, 1696 skb->len, proto, 0); 1697 /* Probably, we should checksum udp header (it should be in cache 1698 * in any case) and data in tiny packets (< rx copybreak). 1699 */ 1700 1701 return 0; 1702 } 1703 1704 /* 1705 * All we need to do is get the socket, and then do a checksum. 1706 */ 1707 1708 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 1709 int proto) 1710 { 1711 struct sock *sk; 1712 struct udphdr *uh; 1713 unsigned short ulen; 1714 struct rtable *rt = skb_rtable(skb); 1715 __be32 saddr, daddr; 1716 struct net *net = dev_net(skb->dev); 1717 1718 /* 1719 * Validate the packet. 1720 */ 1721 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1722 goto drop; /* No space for header. */ 1723 1724 uh = udp_hdr(skb); 1725 ulen = ntohs(uh->len); 1726 saddr = ip_hdr(skb)->saddr; 1727 daddr = ip_hdr(skb)->daddr; 1728 1729 if (ulen > skb->len) 1730 goto short_packet; 1731 1732 if (proto == IPPROTO_UDP) { 1733 /* UDP validates ulen. */ 1734 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1735 goto short_packet; 1736 uh = udp_hdr(skb); 1737 } 1738 1739 if (udp4_csum_init(skb, uh, proto)) 1740 goto csum_error; 1741 1742 sk = skb_steal_sock(skb); 1743 if (sk) { 1744 struct dst_entry *dst = skb_dst(skb); 1745 int ret; 1746 1747 if (unlikely(sk->sk_rx_dst != dst)) 1748 udp_sk_rx_dst_set(sk, dst); 1749 1750 ret = udp_queue_rcv_skb(sk, skb); 1751 sock_put(sk); 1752 /* a return value > 0 means to resubmit the input, but 1753 * it wants the return to be -protocol, or 0 1754 */ 1755 if (ret > 0) 1756 return -ret; 1757 return 0; 1758 } else { 1759 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1760 return __udp4_lib_mcast_deliver(net, skb, uh, 1761 saddr, daddr, udptable); 1762 1763 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 1764 } 1765 1766 if (sk != NULL) { 1767 int ret; 1768 1769 ret = udp_queue_rcv_skb(sk, skb); 1770 sock_put(sk); 1771 1772 /* a return value > 0 means to resubmit the input, but 1773 * it wants the return to be -protocol, or 0 1774 */ 1775 if (ret > 0) 1776 return -ret; 1777 return 0; 1778 } 1779 1780 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1781 goto drop; 1782 nf_reset(skb); 1783 1784 /* No socket. Drop packet silently, if checksum is wrong */ 1785 if (udp_lib_checksum_complete(skb)) 1786 goto csum_error; 1787 1788 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 1789 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1790 1791 /* 1792 * Hmm. We got an UDP packet to a port to which we 1793 * don't wanna listen. Ignore it. 1794 */ 1795 kfree_skb(skb); 1796 return 0; 1797 1798 short_packet: 1799 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 1800 proto == IPPROTO_UDPLITE ? "Lite" : "", 1801 &saddr, ntohs(uh->source), 1802 ulen, skb->len, 1803 &daddr, ntohs(uh->dest)); 1804 goto drop; 1805 1806 csum_error: 1807 /* 1808 * RFC1122: OK. Discards the bad packet silently (as far as 1809 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1810 */ 1811 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 1812 proto == IPPROTO_UDPLITE ? "Lite" : "", 1813 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 1814 ulen); 1815 UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 1816 drop: 1817 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1818 kfree_skb(skb); 1819 return 0; 1820 } 1821 1822 /* We can only early demux multicast if there is a single matching socket. 1823 * If more than one socket found returns NULL 1824 */ 1825 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, 1826 __be16 loc_port, __be32 loc_addr, 1827 __be16 rmt_port, __be32 rmt_addr, 1828 int dif) 1829 { 1830 struct sock *sk, *result; 1831 struct hlist_nulls_node *node; 1832 unsigned short hnum = ntohs(loc_port); 1833 unsigned int count, slot = udp_hashfn(net, hnum, udp_table.mask); 1834 struct udp_hslot *hslot = &udp_table.hash[slot]; 1835 1836 rcu_read_lock(); 1837 begin: 1838 count = 0; 1839 result = NULL; 1840 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 1841 if (__udp_is_mcast_sock(net, sk, 1842 loc_port, loc_addr, 1843 rmt_port, rmt_addr, 1844 dif, hnum)) { 1845 result = sk; 1846 ++count; 1847 } 1848 } 1849 /* 1850 * if the nulls value we got at the end of this lookup is 1851 * not the expected one, we must restart lookup. 1852 * We probably met an item that was moved to another chain. 1853 */ 1854 if (get_nulls_value(node) != slot) 1855 goto begin; 1856 1857 if (result) { 1858 if (count != 1 || 1859 unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 1860 result = NULL; 1861 else if (unlikely(!__udp_is_mcast_sock(net, result, 1862 loc_port, loc_addr, 1863 rmt_port, rmt_addr, 1864 dif, hnum))) { 1865 sock_put(result); 1866 result = NULL; 1867 } 1868 } 1869 rcu_read_unlock(); 1870 return result; 1871 } 1872 1873 /* For unicast we should only early demux connected sockets or we can 1874 * break forwarding setups. The chains here can be long so only check 1875 * if the first socket is an exact match and if not move on. 1876 */ 1877 static struct sock *__udp4_lib_demux_lookup(struct net *net, 1878 __be16 loc_port, __be32 loc_addr, 1879 __be16 rmt_port, __be32 rmt_addr, 1880 int dif) 1881 { 1882 struct sock *sk, *result; 1883 struct hlist_nulls_node *node; 1884 unsigned short hnum = ntohs(loc_port); 1885 unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum); 1886 unsigned int slot2 = hash2 & udp_table.mask; 1887 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 1888 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr) 1889 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 1890 1891 rcu_read_lock(); 1892 result = NULL; 1893 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { 1894 if (INET_MATCH(sk, net, acookie, 1895 rmt_addr, loc_addr, ports, dif)) 1896 result = sk; 1897 /* Only check first socket in chain */ 1898 break; 1899 } 1900 1901 if (result) { 1902 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 1903 result = NULL; 1904 else if (unlikely(!INET_MATCH(sk, net, acookie, 1905 rmt_addr, loc_addr, 1906 ports, dif))) { 1907 sock_put(result); 1908 result = NULL; 1909 } 1910 } 1911 rcu_read_unlock(); 1912 return result; 1913 } 1914 1915 void udp_v4_early_demux(struct sk_buff *skb) 1916 { 1917 struct net *net = dev_net(skb->dev); 1918 const struct iphdr *iph; 1919 const struct udphdr *uh; 1920 struct sock *sk; 1921 struct dst_entry *dst; 1922 int dif = skb->dev->ifindex; 1923 1924 /* validate the packet */ 1925 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) 1926 return; 1927 1928 iph = ip_hdr(skb); 1929 uh = udp_hdr(skb); 1930 1931 if (skb->pkt_type == PACKET_BROADCAST || 1932 skb->pkt_type == PACKET_MULTICAST) 1933 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, 1934 uh->source, iph->saddr, dif); 1935 else if (skb->pkt_type == PACKET_HOST) 1936 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, 1937 uh->source, iph->saddr, dif); 1938 else 1939 return; 1940 1941 if (!sk) 1942 return; 1943 1944 skb->sk = sk; 1945 skb->destructor = sock_edemux; 1946 dst = sk->sk_rx_dst; 1947 1948 if (dst) 1949 dst = dst_check(dst, 0); 1950 if (dst) 1951 skb_dst_set_noref(skb, dst); 1952 } 1953 1954 int udp_rcv(struct sk_buff *skb) 1955 { 1956 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 1957 } 1958 1959 void udp_destroy_sock(struct sock *sk) 1960 { 1961 struct udp_sock *up = udp_sk(sk); 1962 bool slow = lock_sock_fast(sk); 1963 udp_flush_pending_frames(sk); 1964 unlock_sock_fast(sk, slow); 1965 if (static_key_false(&udp_encap_needed) && up->encap_type) { 1966 void (*encap_destroy)(struct sock *sk); 1967 encap_destroy = ACCESS_ONCE(up->encap_destroy); 1968 if (encap_destroy) 1969 encap_destroy(sk); 1970 } 1971 } 1972 1973 /* 1974 * Socket option code for UDP 1975 */ 1976 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 1977 char __user *optval, unsigned int optlen, 1978 int (*push_pending_frames)(struct sock *)) 1979 { 1980 struct udp_sock *up = udp_sk(sk); 1981 int val; 1982 int err = 0; 1983 int is_udplite = IS_UDPLITE(sk); 1984 1985 if (optlen < sizeof(int)) 1986 return -EINVAL; 1987 1988 if (get_user(val, (int __user *)optval)) 1989 return -EFAULT; 1990 1991 switch (optname) { 1992 case UDP_CORK: 1993 if (val != 0) { 1994 up->corkflag = 1; 1995 } else { 1996 up->corkflag = 0; 1997 lock_sock(sk); 1998 (*push_pending_frames)(sk); 1999 release_sock(sk); 2000 } 2001 break; 2002 2003 case UDP_ENCAP: 2004 switch (val) { 2005 case 0: 2006 case UDP_ENCAP_ESPINUDP: 2007 case UDP_ENCAP_ESPINUDP_NON_IKE: 2008 up->encap_rcv = xfrm4_udp_encap_rcv; 2009 /* FALLTHROUGH */ 2010 case UDP_ENCAP_L2TPINUDP: 2011 up->encap_type = val; 2012 udp_encap_enable(); 2013 break; 2014 default: 2015 err = -ENOPROTOOPT; 2016 break; 2017 } 2018 break; 2019 2020 /* 2021 * UDP-Lite's partial checksum coverage (RFC 3828). 2022 */ 2023 /* The sender sets actual checksum coverage length via this option. 2024 * The case coverage > packet length is handled by send module. */ 2025 case UDPLITE_SEND_CSCOV: 2026 if (!is_udplite) /* Disable the option on UDP sockets */ 2027 return -ENOPROTOOPT; 2028 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 2029 val = 8; 2030 else if (val > USHRT_MAX) 2031 val = USHRT_MAX; 2032 up->pcslen = val; 2033 up->pcflag |= UDPLITE_SEND_CC; 2034 break; 2035 2036 /* The receiver specifies a minimum checksum coverage value. To make 2037 * sense, this should be set to at least 8 (as done below). If zero is 2038 * used, this again means full checksum coverage. */ 2039 case UDPLITE_RECV_CSCOV: 2040 if (!is_udplite) /* Disable the option on UDP sockets */ 2041 return -ENOPROTOOPT; 2042 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 2043 val = 8; 2044 else if (val > USHRT_MAX) 2045 val = USHRT_MAX; 2046 up->pcrlen = val; 2047 up->pcflag |= UDPLITE_RECV_CC; 2048 break; 2049 2050 default: 2051 err = -ENOPROTOOPT; 2052 break; 2053 } 2054 2055 return err; 2056 } 2057 EXPORT_SYMBOL(udp_lib_setsockopt); 2058 2059 int udp_setsockopt(struct sock *sk, int level, int optname, 2060 char __user *optval, unsigned int optlen) 2061 { 2062 if (level == SOL_UDP || level == SOL_UDPLITE) 2063 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2064 udp_push_pending_frames); 2065 return ip_setsockopt(sk, level, optname, optval, optlen); 2066 } 2067 2068 #ifdef CONFIG_COMPAT 2069 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 2070 char __user *optval, unsigned int optlen) 2071 { 2072 if (level == SOL_UDP || level == SOL_UDPLITE) 2073 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2074 udp_push_pending_frames); 2075 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 2076 } 2077 #endif 2078 2079 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 2080 char __user *optval, int __user *optlen) 2081 { 2082 struct udp_sock *up = udp_sk(sk); 2083 int val, len; 2084 2085 if (get_user(len, optlen)) 2086 return -EFAULT; 2087 2088 len = min_t(unsigned int, len, sizeof(int)); 2089 2090 if (len < 0) 2091 return -EINVAL; 2092 2093 switch (optname) { 2094 case UDP_CORK: 2095 val = up->corkflag; 2096 break; 2097 2098 case UDP_ENCAP: 2099 val = up->encap_type; 2100 break; 2101 2102 /* The following two cannot be changed on UDP sockets, the return is 2103 * always 0 (which corresponds to the full checksum coverage of UDP). */ 2104 case UDPLITE_SEND_CSCOV: 2105 val = up->pcslen; 2106 break; 2107 2108 case UDPLITE_RECV_CSCOV: 2109 val = up->pcrlen; 2110 break; 2111 2112 default: 2113 return -ENOPROTOOPT; 2114 } 2115 2116 if (put_user(len, optlen)) 2117 return -EFAULT; 2118 if (copy_to_user(optval, &val, len)) 2119 return -EFAULT; 2120 return 0; 2121 } 2122 EXPORT_SYMBOL(udp_lib_getsockopt); 2123 2124 int udp_getsockopt(struct sock *sk, int level, int optname, 2125 char __user *optval, int __user *optlen) 2126 { 2127 if (level == SOL_UDP || level == SOL_UDPLITE) 2128 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2129 return ip_getsockopt(sk, level, optname, optval, optlen); 2130 } 2131 2132 #ifdef CONFIG_COMPAT 2133 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 2134 char __user *optval, int __user *optlen) 2135 { 2136 if (level == SOL_UDP || level == SOL_UDPLITE) 2137 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2138 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 2139 } 2140 #endif 2141 /** 2142 * udp_poll - wait for a UDP event. 2143 * @file - file struct 2144 * @sock - socket 2145 * @wait - poll table 2146 * 2147 * This is same as datagram poll, except for the special case of 2148 * blocking sockets. If application is using a blocking fd 2149 * and a packet with checksum error is in the queue; 2150 * then it could get return from select indicating data available 2151 * but then block when reading it. Add special case code 2152 * to work around these arguably broken applications. 2153 */ 2154 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 2155 { 2156 unsigned int mask = datagram_poll(file, sock, wait); 2157 struct sock *sk = sock->sk; 2158 2159 sock_rps_record_flow(sk); 2160 2161 /* Check for false positives due to checksum errors */ 2162 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 2163 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk)) 2164 mask &= ~(POLLIN | POLLRDNORM); 2165 2166 return mask; 2167 2168 } 2169 EXPORT_SYMBOL(udp_poll); 2170 2171 struct proto udp_prot = { 2172 .name = "UDP", 2173 .owner = THIS_MODULE, 2174 .close = udp_lib_close, 2175 .connect = ip4_datagram_connect, 2176 .disconnect = udp_disconnect, 2177 .ioctl = udp_ioctl, 2178 .destroy = udp_destroy_sock, 2179 .setsockopt = udp_setsockopt, 2180 .getsockopt = udp_getsockopt, 2181 .sendmsg = udp_sendmsg, 2182 .recvmsg = udp_recvmsg, 2183 .sendpage = udp_sendpage, 2184 .backlog_rcv = __udp_queue_rcv_skb, 2185 .release_cb = ip4_datagram_release_cb, 2186 .hash = udp_lib_hash, 2187 .unhash = udp_lib_unhash, 2188 .rehash = udp_v4_rehash, 2189 .get_port = udp_v4_get_port, 2190 .memory_allocated = &udp_memory_allocated, 2191 .sysctl_mem = sysctl_udp_mem, 2192 .sysctl_wmem = &sysctl_udp_wmem_min, 2193 .sysctl_rmem = &sysctl_udp_rmem_min, 2194 .obj_size = sizeof(struct udp_sock), 2195 .slab_flags = SLAB_DESTROY_BY_RCU, 2196 .h.udp_table = &udp_table, 2197 #ifdef CONFIG_COMPAT 2198 .compat_setsockopt = compat_udp_setsockopt, 2199 .compat_getsockopt = compat_udp_getsockopt, 2200 #endif 2201 .clear_sk = sk_prot_clear_portaddr_nulls, 2202 }; 2203 EXPORT_SYMBOL(udp_prot); 2204 2205 /* ------------------------------------------------------------------------ */ 2206 #ifdef CONFIG_PROC_FS 2207 2208 static struct sock *udp_get_first(struct seq_file *seq, int start) 2209 { 2210 struct sock *sk; 2211 struct udp_iter_state *state = seq->private; 2212 struct net *net = seq_file_net(seq); 2213 2214 for (state->bucket = start; state->bucket <= state->udp_table->mask; 2215 ++state->bucket) { 2216 struct hlist_nulls_node *node; 2217 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; 2218 2219 if (hlist_nulls_empty(&hslot->head)) 2220 continue; 2221 2222 spin_lock_bh(&hslot->lock); 2223 sk_nulls_for_each(sk, node, &hslot->head) { 2224 if (!net_eq(sock_net(sk), net)) 2225 continue; 2226 if (sk->sk_family == state->family) 2227 goto found; 2228 } 2229 spin_unlock_bh(&hslot->lock); 2230 } 2231 sk = NULL; 2232 found: 2233 return sk; 2234 } 2235 2236 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2237 { 2238 struct udp_iter_state *state = seq->private; 2239 struct net *net = seq_file_net(seq); 2240 2241 do { 2242 sk = sk_nulls_next(sk); 2243 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); 2244 2245 if (!sk) { 2246 if (state->bucket <= state->udp_table->mask) 2247 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2248 return udp_get_first(seq, state->bucket + 1); 2249 } 2250 return sk; 2251 } 2252 2253 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2254 { 2255 struct sock *sk = udp_get_first(seq, 0); 2256 2257 if (sk) 2258 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2259 --pos; 2260 return pos ? NULL : sk; 2261 } 2262 2263 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2264 { 2265 struct udp_iter_state *state = seq->private; 2266 state->bucket = MAX_UDP_PORTS; 2267 2268 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2269 } 2270 2271 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2272 { 2273 struct sock *sk; 2274 2275 if (v == SEQ_START_TOKEN) 2276 sk = udp_get_idx(seq, 0); 2277 else 2278 sk = udp_get_next(seq, v); 2279 2280 ++*pos; 2281 return sk; 2282 } 2283 2284 static void udp_seq_stop(struct seq_file *seq, void *v) 2285 { 2286 struct udp_iter_state *state = seq->private; 2287 2288 if (state->bucket <= state->udp_table->mask) 2289 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2290 } 2291 2292 int udp_seq_open(struct inode *inode, struct file *file) 2293 { 2294 struct udp_seq_afinfo *afinfo = PDE_DATA(inode); 2295 struct udp_iter_state *s; 2296 int err; 2297 2298 err = seq_open_net(inode, file, &afinfo->seq_ops, 2299 sizeof(struct udp_iter_state)); 2300 if (err < 0) 2301 return err; 2302 2303 s = ((struct seq_file *)file->private_data)->private; 2304 s->family = afinfo->family; 2305 s->udp_table = afinfo->udp_table; 2306 return err; 2307 } 2308 EXPORT_SYMBOL(udp_seq_open); 2309 2310 /* ------------------------------------------------------------------------ */ 2311 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) 2312 { 2313 struct proc_dir_entry *p; 2314 int rc = 0; 2315 2316 afinfo->seq_ops.start = udp_seq_start; 2317 afinfo->seq_ops.next = udp_seq_next; 2318 afinfo->seq_ops.stop = udp_seq_stop; 2319 2320 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 2321 afinfo->seq_fops, afinfo); 2322 if (!p) 2323 rc = -ENOMEM; 2324 return rc; 2325 } 2326 EXPORT_SYMBOL(udp_proc_register); 2327 2328 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 2329 { 2330 remove_proc_entry(afinfo->name, net->proc_net); 2331 } 2332 EXPORT_SYMBOL(udp_proc_unregister); 2333 2334 /* ------------------------------------------------------------------------ */ 2335 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2336 int bucket) 2337 { 2338 struct inet_sock *inet = inet_sk(sp); 2339 __be32 dest = inet->inet_daddr; 2340 __be32 src = inet->inet_rcv_saddr; 2341 __u16 destp = ntohs(inet->inet_dport); 2342 __u16 srcp = ntohs(inet->inet_sport); 2343 2344 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2345 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 2346 bucket, src, srcp, dest, destp, sp->sk_state, 2347 sk_wmem_alloc_get(sp), 2348 sk_rmem_alloc_get(sp), 2349 0, 0L, 0, 2350 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2351 0, sock_i_ino(sp), 2352 atomic_read(&sp->sk_refcnt), sp, 2353 atomic_read(&sp->sk_drops)); 2354 } 2355 2356 int udp4_seq_show(struct seq_file *seq, void *v) 2357 { 2358 seq_setwidth(seq, 127); 2359 if (v == SEQ_START_TOKEN) 2360 seq_puts(seq, " sl local_address rem_address st tx_queue " 2361 "rx_queue tr tm->when retrnsmt uid timeout " 2362 "inode ref pointer drops"); 2363 else { 2364 struct udp_iter_state *state = seq->private; 2365 2366 udp4_format_sock(v, seq, state->bucket); 2367 } 2368 seq_pad(seq, '\n'); 2369 return 0; 2370 } 2371 2372 static const struct file_operations udp_afinfo_seq_fops = { 2373 .owner = THIS_MODULE, 2374 .open = udp_seq_open, 2375 .read = seq_read, 2376 .llseek = seq_lseek, 2377 .release = seq_release_net 2378 }; 2379 2380 /* ------------------------------------------------------------------------ */ 2381 static struct udp_seq_afinfo udp4_seq_afinfo = { 2382 .name = "udp", 2383 .family = AF_INET, 2384 .udp_table = &udp_table, 2385 .seq_fops = &udp_afinfo_seq_fops, 2386 .seq_ops = { 2387 .show = udp4_seq_show, 2388 }, 2389 }; 2390 2391 static int __net_init udp4_proc_init_net(struct net *net) 2392 { 2393 return udp_proc_register(net, &udp4_seq_afinfo); 2394 } 2395 2396 static void __net_exit udp4_proc_exit_net(struct net *net) 2397 { 2398 udp_proc_unregister(net, &udp4_seq_afinfo); 2399 } 2400 2401 static struct pernet_operations udp4_net_ops = { 2402 .init = udp4_proc_init_net, 2403 .exit = udp4_proc_exit_net, 2404 }; 2405 2406 int __init udp4_proc_init(void) 2407 { 2408 return register_pernet_subsys(&udp4_net_ops); 2409 } 2410 2411 void udp4_proc_exit(void) 2412 { 2413 unregister_pernet_subsys(&udp4_net_ops); 2414 } 2415 #endif /* CONFIG_PROC_FS */ 2416 2417 static __initdata unsigned long uhash_entries; 2418 static int __init set_uhash_entries(char *str) 2419 { 2420 ssize_t ret; 2421 2422 if (!str) 2423 return 0; 2424 2425 ret = kstrtoul(str, 0, &uhash_entries); 2426 if (ret) 2427 return 0; 2428 2429 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2430 uhash_entries = UDP_HTABLE_SIZE_MIN; 2431 return 1; 2432 } 2433 __setup("uhash_entries=", set_uhash_entries); 2434 2435 void __init udp_table_init(struct udp_table *table, const char *name) 2436 { 2437 unsigned int i; 2438 2439 table->hash = alloc_large_system_hash(name, 2440 2 * sizeof(struct udp_hslot), 2441 uhash_entries, 2442 21, /* one slot per 2 MB */ 2443 0, 2444 &table->log, 2445 &table->mask, 2446 UDP_HTABLE_SIZE_MIN, 2447 64 * 1024); 2448 2449 table->hash2 = table->hash + (table->mask + 1); 2450 for (i = 0; i <= table->mask; i++) { 2451 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); 2452 table->hash[i].count = 0; 2453 spin_lock_init(&table->hash[i].lock); 2454 } 2455 for (i = 0; i <= table->mask; i++) { 2456 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); 2457 table->hash2[i].count = 0; 2458 spin_lock_init(&table->hash2[i].lock); 2459 } 2460 } 2461 2462 void __init udp_init(void) 2463 { 2464 unsigned long limit; 2465 2466 udp_table_init(&udp_table, "UDP"); 2467 limit = nr_free_buffer_pages() / 8; 2468 limit = max(limit, 128UL); 2469 sysctl_udp_mem[0] = limit / 4 * 3; 2470 sysctl_udp_mem[1] = limit; 2471 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 2472 2473 sysctl_udp_rmem_min = SK_MEM_QUANTUM; 2474 sysctl_udp_wmem_min = SK_MEM_QUANTUM; 2475 } 2476 2477 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 2478 netdev_features_t features) 2479 { 2480 struct sk_buff *segs = ERR_PTR(-EINVAL); 2481 u16 mac_offset = skb->mac_header; 2482 int mac_len = skb->mac_len; 2483 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); 2484 __be16 protocol = skb->protocol; 2485 netdev_features_t enc_features; 2486 int outer_hlen; 2487 2488 if (unlikely(!pskb_may_pull(skb, tnl_hlen))) 2489 goto out; 2490 2491 skb->encapsulation = 0; 2492 __skb_pull(skb, tnl_hlen); 2493 skb_reset_mac_header(skb); 2494 skb_set_network_header(skb, skb_inner_network_offset(skb)); 2495 skb->mac_len = skb_inner_network_offset(skb); 2496 skb->protocol = htons(ETH_P_TEB); 2497 2498 /* segment inner packet. */ 2499 enc_features = skb->dev->hw_enc_features & netif_skb_features(skb); 2500 segs = skb_mac_gso_segment(skb, enc_features); 2501 if (!segs || IS_ERR(segs)) { 2502 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, 2503 mac_len); 2504 goto out; 2505 } 2506 2507 outer_hlen = skb_tnl_header_len(skb); 2508 skb = segs; 2509 do { 2510 struct udphdr *uh; 2511 int udp_offset = outer_hlen - tnl_hlen; 2512 2513 skb_reset_inner_headers(skb); 2514 skb->encapsulation = 1; 2515 2516 skb->mac_len = mac_len; 2517 2518 skb_push(skb, outer_hlen); 2519 skb_reset_mac_header(skb); 2520 skb_set_network_header(skb, mac_len); 2521 skb_set_transport_header(skb, udp_offset); 2522 uh = udp_hdr(skb); 2523 uh->len = htons(skb->len - udp_offset); 2524 2525 /* csum segment if tunnel sets skb with csum. */ 2526 if (protocol == htons(ETH_P_IP) && unlikely(uh->check)) { 2527 struct iphdr *iph = ip_hdr(skb); 2528 2529 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, 2530 skb->len - udp_offset, 2531 IPPROTO_UDP, 0); 2532 uh->check = csum_fold(skb_checksum(skb, udp_offset, 2533 skb->len - udp_offset, 0)); 2534 if (uh->check == 0) 2535 uh->check = CSUM_MANGLED_0; 2536 2537 } else if (protocol == htons(ETH_P_IPV6)) { 2538 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 2539 u32 len = skb->len - udp_offset; 2540 2541 uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, 2542 len, IPPROTO_UDP, 0); 2543 uh->check = csum_fold(skb_checksum(skb, udp_offset, len, 0)); 2544 if (uh->check == 0) 2545 uh->check = CSUM_MANGLED_0; 2546 skb->ip_summed = CHECKSUM_NONE; 2547 } 2548 2549 skb->protocol = protocol; 2550 } while ((skb = skb->next)); 2551 out: 2552 return segs; 2553 } 2554