1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * The User Datagram Protocol (UDP). 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 11 * Alan Cox, <alan@lxorguk.ukuu.org.uk> 12 * Hirokazu Takahashi, <taka@valinux.co.jp> 13 * 14 * Fixes: 15 * Alan Cox : verify_area() calls 16 * Alan Cox : stopped close while in use off icmp 17 * messages. Not a fix but a botch that 18 * for udp at least is 'valid'. 19 * Alan Cox : Fixed icmp handling properly 20 * Alan Cox : Correct error for oversized datagrams 21 * Alan Cox : Tidied select() semantics. 22 * Alan Cox : udp_err() fixed properly, also now 23 * select and read wake correctly on errors 24 * Alan Cox : udp_send verify_area moved to avoid mem leak 25 * Alan Cox : UDP can count its memory 26 * Alan Cox : send to an unknown connection causes 27 * an ECONNREFUSED off the icmp, but 28 * does NOT close. 29 * Alan Cox : Switched to new sk_buff handlers. No more backlog! 30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK 31 * bug no longer crashes it. 32 * Fred Van Kempen : Net2e support for sk->broadcast. 33 * Alan Cox : Uses skb_free_datagram 34 * Alan Cox : Added get/set sockopt support. 35 * Alan Cox : Broadcasting without option set returns EACCES. 36 * Alan Cox : No wakeup calls. Instead we now use the callbacks. 37 * Alan Cox : Use ip_tos and ip_ttl 38 * Alan Cox : SNMP Mibs 39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. 40 * Matt Dillon : UDP length checks. 41 * Alan Cox : Smarter af_inet used properly. 42 * Alan Cox : Use new kernel side addressing. 43 * Alan Cox : Incorrect return on truncated datagram receive. 44 * Arnt Gulbrandsen : New udp_send and stuff 45 * Alan Cox : Cache last socket 46 * Alan Cox : Route cache 47 * Jon Peatfield : Minor efficiency fix to sendto(). 48 * Mike Shaver : RFC1122 checks. 49 * Alan Cox : Nonblocking error fix. 50 * Willy Konynenberg : Transparent proxying support. 51 * Mike McLagan : Routing by source 52 * David S. Miller : New socket lookup architecture. 53 * Last socket cache retained as it 54 * does have a high hit rate. 55 * Olaf Kirch : Don't linearise iovec on sendmsg. 56 * Andi Kleen : Some cleanups, cache destination entry 57 * for connect. 58 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 59 * Melvin Smith : Check msg_name not msg_namelen in sendto(), 60 * return ENOTCONN for unconnected sockets (POSIX) 61 * Janos Farkas : don't deliver multi/broadcasts to a different 62 * bound-to-device socket 63 * Hirokazu Takahashi : HW checksumming for outgoing UDP 64 * datagrams. 65 * Hirokazu Takahashi : sendfile() on UDP works now. 66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file 67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind 69 * a single port at the same time. 70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support 71 * James Chapman : Add L2TP encapsulation type. 72 * 73 * 74 * This program is free software; you can redistribute it and/or 75 * modify it under the terms of the GNU General Public License 76 * as published by the Free Software Foundation; either version 77 * 2 of the License, or (at your option) any later version. 78 */ 79 80 #define pr_fmt(fmt) "UDP: " fmt 81 82 #include <asm/uaccess.h> 83 #include <asm/ioctls.h> 84 #include <linux/bootmem.h> 85 #include <linux/highmem.h> 86 #include <linux/swap.h> 87 #include <linux/types.h> 88 #include <linux/fcntl.h> 89 #include <linux/module.h> 90 #include <linux/socket.h> 91 #include <linux/sockios.h> 92 #include <linux/igmp.h> 93 #include <linux/in.h> 94 #include <linux/errno.h> 95 #include <linux/timer.h> 96 #include <linux/mm.h> 97 #include <linux/inet.h> 98 #include <linux/netdevice.h> 99 #include <linux/slab.h> 100 #include <net/tcp_states.h> 101 #include <linux/skbuff.h> 102 #include <linux/proc_fs.h> 103 #include <linux/seq_file.h> 104 #include <net/net_namespace.h> 105 #include <net/icmp.h> 106 #include <net/route.h> 107 #include <net/checksum.h> 108 #include <net/xfrm.h> 109 #include <trace/events/udp.h> 110 #include <linux/static_key.h> 111 #include <trace/events/skb.h> 112 #include <net/busy_poll.h> 113 #include "udp_impl.h" 114 115 struct udp_table udp_table __read_mostly; 116 EXPORT_SYMBOL(udp_table); 117 118 long sysctl_udp_mem[3] __read_mostly; 119 EXPORT_SYMBOL(sysctl_udp_mem); 120 121 int sysctl_udp_rmem_min __read_mostly; 122 EXPORT_SYMBOL(sysctl_udp_rmem_min); 123 124 int sysctl_udp_wmem_min __read_mostly; 125 EXPORT_SYMBOL(sysctl_udp_wmem_min); 126 127 atomic_long_t udp_memory_allocated; 128 EXPORT_SYMBOL(udp_memory_allocated); 129 130 #define MAX_UDP_PORTS 65536 131 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 132 133 static int udp_lib_lport_inuse(struct net *net, __u16 num, 134 const struct udp_hslot *hslot, 135 unsigned long *bitmap, 136 struct sock *sk, 137 int (*saddr_comp)(const struct sock *sk1, 138 const struct sock *sk2), 139 unsigned int log) 140 { 141 struct sock *sk2; 142 struct hlist_nulls_node *node; 143 kuid_t uid = sock_i_uid(sk); 144 145 sk_nulls_for_each(sk2, node, &hslot->head) 146 if (net_eq(sock_net(sk2), net) && 147 sk2 != sk && 148 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 149 (!sk2->sk_reuse || !sk->sk_reuse) && 150 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 151 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 152 (!sk2->sk_reuseport || !sk->sk_reuseport || 153 !uid_eq(uid, sock_i_uid(sk2))) && 154 (*saddr_comp)(sk, sk2)) { 155 if (bitmap) 156 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 157 bitmap); 158 else 159 return 1; 160 } 161 return 0; 162 } 163 164 /* 165 * Note: we still hold spinlock of primary hash chain, so no other writer 166 * can insert/delete a socket with local_port == num 167 */ 168 static int udp_lib_lport_inuse2(struct net *net, __u16 num, 169 struct udp_hslot *hslot2, 170 struct sock *sk, 171 int (*saddr_comp)(const struct sock *sk1, 172 const struct sock *sk2)) 173 { 174 struct sock *sk2; 175 struct hlist_nulls_node *node; 176 kuid_t uid = sock_i_uid(sk); 177 int res = 0; 178 179 spin_lock(&hslot2->lock); 180 udp_portaddr_for_each_entry(sk2, node, &hslot2->head) 181 if (net_eq(sock_net(sk2), net) && 182 sk2 != sk && 183 (udp_sk(sk2)->udp_port_hash == num) && 184 (!sk2->sk_reuse || !sk->sk_reuse) && 185 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 186 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 187 (!sk2->sk_reuseport || !sk->sk_reuseport || 188 !uid_eq(uid, sock_i_uid(sk2))) && 189 (*saddr_comp)(sk, sk2)) { 190 res = 1; 191 break; 192 } 193 spin_unlock(&hslot2->lock); 194 return res; 195 } 196 197 /** 198 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 199 * 200 * @sk: socket struct in question 201 * @snum: port number to look up 202 * @saddr_comp: AF-dependent comparison of bound local IP addresses 203 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 204 * with NULL address 205 */ 206 int udp_lib_get_port(struct sock *sk, unsigned short snum, 207 int (*saddr_comp)(const struct sock *sk1, 208 const struct sock *sk2), 209 unsigned int hash2_nulladdr) 210 { 211 struct udp_hslot *hslot, *hslot2; 212 struct udp_table *udptable = sk->sk_prot->h.udp_table; 213 int error = 1; 214 struct net *net = sock_net(sk); 215 216 if (!snum) { 217 int low, high, remaining; 218 unsigned int rand; 219 unsigned short first, last; 220 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 221 222 inet_get_local_port_range(net, &low, &high); 223 remaining = (high - low) + 1; 224 225 rand = net_random(); 226 first = (((u64)rand * remaining) >> 32) + low; 227 /* 228 * force rand to be an odd multiple of UDP_HTABLE_SIZE 229 */ 230 rand = (rand | 1) * (udptable->mask + 1); 231 last = first + udptable->mask + 1; 232 do { 233 hslot = udp_hashslot(udptable, net, first); 234 bitmap_zero(bitmap, PORTS_PER_CHAIN); 235 spin_lock_bh(&hslot->lock); 236 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 237 saddr_comp, udptable->log); 238 239 snum = first; 240 /* 241 * Iterate on all possible values of snum for this hash. 242 * Using steps of an odd multiple of UDP_HTABLE_SIZE 243 * give us randomization and full range coverage. 244 */ 245 do { 246 if (low <= snum && snum <= high && 247 !test_bit(snum >> udptable->log, bitmap) && 248 !inet_is_reserved_local_port(snum)) 249 goto found; 250 snum += rand; 251 } while (snum != first); 252 spin_unlock_bh(&hslot->lock); 253 } while (++first != last); 254 goto fail; 255 } else { 256 hslot = udp_hashslot(udptable, net, snum); 257 spin_lock_bh(&hslot->lock); 258 if (hslot->count > 10) { 259 int exist; 260 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 261 262 slot2 &= udptable->mask; 263 hash2_nulladdr &= udptable->mask; 264 265 hslot2 = udp_hashslot2(udptable, slot2); 266 if (hslot->count < hslot2->count) 267 goto scan_primary_hash; 268 269 exist = udp_lib_lport_inuse2(net, snum, hslot2, 270 sk, saddr_comp); 271 if (!exist && (hash2_nulladdr != slot2)) { 272 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 273 exist = udp_lib_lport_inuse2(net, snum, hslot2, 274 sk, saddr_comp); 275 } 276 if (exist) 277 goto fail_unlock; 278 else 279 goto found; 280 } 281 scan_primary_hash: 282 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 283 saddr_comp, 0)) 284 goto fail_unlock; 285 } 286 found: 287 inet_sk(sk)->inet_num = snum; 288 udp_sk(sk)->udp_port_hash = snum; 289 udp_sk(sk)->udp_portaddr_hash ^= snum; 290 if (sk_unhashed(sk)) { 291 sk_nulls_add_node_rcu(sk, &hslot->head); 292 hslot->count++; 293 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 294 295 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 296 spin_lock(&hslot2->lock); 297 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 298 &hslot2->head); 299 hslot2->count++; 300 spin_unlock(&hslot2->lock); 301 } 302 error = 0; 303 fail_unlock: 304 spin_unlock_bh(&hslot->lock); 305 fail: 306 return error; 307 } 308 EXPORT_SYMBOL(udp_lib_get_port); 309 310 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 311 { 312 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 313 314 return (!ipv6_only_sock(sk2) && 315 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr || 316 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr)); 317 } 318 319 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr, 320 unsigned int port) 321 { 322 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 323 } 324 325 int udp_v4_get_port(struct sock *sk, unsigned short snum) 326 { 327 unsigned int hash2_nulladdr = 328 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 329 unsigned int hash2_partial = 330 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 331 332 /* precompute partial secondary hash */ 333 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 334 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr); 335 } 336 337 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr, 338 unsigned short hnum, 339 __be16 sport, __be32 daddr, __be16 dport, int dif) 340 { 341 int score = -1; 342 343 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && 344 !ipv6_only_sock(sk)) { 345 struct inet_sock *inet = inet_sk(sk); 346 347 score = (sk->sk_family == PF_INET ? 2 : 1); 348 if (inet->inet_rcv_saddr) { 349 if (inet->inet_rcv_saddr != daddr) 350 return -1; 351 score += 4; 352 } 353 if (inet->inet_daddr) { 354 if (inet->inet_daddr != saddr) 355 return -1; 356 score += 4; 357 } 358 if (inet->inet_dport) { 359 if (inet->inet_dport != sport) 360 return -1; 361 score += 4; 362 } 363 if (sk->sk_bound_dev_if) { 364 if (sk->sk_bound_dev_if != dif) 365 return -1; 366 score += 4; 367 } 368 } 369 return score; 370 } 371 372 /* 373 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num) 374 */ 375 static inline int compute_score2(struct sock *sk, struct net *net, 376 __be32 saddr, __be16 sport, 377 __be32 daddr, unsigned int hnum, int dif) 378 { 379 int score = -1; 380 381 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) { 382 struct inet_sock *inet = inet_sk(sk); 383 384 if (inet->inet_rcv_saddr != daddr) 385 return -1; 386 if (inet->inet_num != hnum) 387 return -1; 388 389 score = (sk->sk_family == PF_INET ? 2 : 1); 390 if (inet->inet_daddr) { 391 if (inet->inet_daddr != saddr) 392 return -1; 393 score += 4; 394 } 395 if (inet->inet_dport) { 396 if (inet->inet_dport != sport) 397 return -1; 398 score += 4; 399 } 400 if (sk->sk_bound_dev_if) { 401 if (sk->sk_bound_dev_if != dif) 402 return -1; 403 score += 4; 404 } 405 } 406 return score; 407 } 408 409 410 /* called with read_rcu_lock() */ 411 static struct sock *udp4_lib_lookup2(struct net *net, 412 __be32 saddr, __be16 sport, 413 __be32 daddr, unsigned int hnum, int dif, 414 struct udp_hslot *hslot2, unsigned int slot2) 415 { 416 struct sock *sk, *result; 417 struct hlist_nulls_node *node; 418 int score, badness, matches = 0, reuseport = 0; 419 u32 hash = 0; 420 421 begin: 422 result = NULL; 423 badness = 0; 424 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { 425 score = compute_score2(sk, net, saddr, sport, 426 daddr, hnum, dif); 427 if (score > badness) { 428 result = sk; 429 badness = score; 430 reuseport = sk->sk_reuseport; 431 if (reuseport) { 432 hash = inet_ehashfn(net, daddr, hnum, 433 saddr, sport); 434 matches = 1; 435 } 436 } else if (score == badness && reuseport) { 437 matches++; 438 if (((u64)hash * matches) >> 32 == 0) 439 result = sk; 440 hash = next_pseudo_random32(hash); 441 } 442 } 443 /* 444 * if the nulls value we got at the end of this lookup is 445 * not the expected one, we must restart lookup. 446 * We probably met an item that was moved to another chain. 447 */ 448 if (get_nulls_value(node) != slot2) 449 goto begin; 450 if (result) { 451 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 452 result = NULL; 453 else if (unlikely(compute_score2(result, net, saddr, sport, 454 daddr, hnum, dif) < badness)) { 455 sock_put(result); 456 goto begin; 457 } 458 } 459 return result; 460 } 461 462 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 463 * harder than this. -DaveM 464 */ 465 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 466 __be16 sport, __be32 daddr, __be16 dport, 467 int dif, struct udp_table *udptable) 468 { 469 struct sock *sk, *result; 470 struct hlist_nulls_node *node; 471 unsigned short hnum = ntohs(dport); 472 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); 473 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; 474 int score, badness, matches = 0, reuseport = 0; 475 u32 hash = 0; 476 477 rcu_read_lock(); 478 if (hslot->count > 10) { 479 hash2 = udp4_portaddr_hash(net, daddr, hnum); 480 slot2 = hash2 & udptable->mask; 481 hslot2 = &udptable->hash2[slot2]; 482 if (hslot->count < hslot2->count) 483 goto begin; 484 485 result = udp4_lib_lookup2(net, saddr, sport, 486 daddr, hnum, dif, 487 hslot2, slot2); 488 if (!result) { 489 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 490 slot2 = hash2 & udptable->mask; 491 hslot2 = &udptable->hash2[slot2]; 492 if (hslot->count < hslot2->count) 493 goto begin; 494 495 result = udp4_lib_lookup2(net, saddr, sport, 496 htonl(INADDR_ANY), hnum, dif, 497 hslot2, slot2); 498 } 499 rcu_read_unlock(); 500 return result; 501 } 502 begin: 503 result = NULL; 504 badness = 0; 505 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 506 score = compute_score(sk, net, saddr, hnum, sport, 507 daddr, dport, dif); 508 if (score > badness) { 509 result = sk; 510 badness = score; 511 reuseport = sk->sk_reuseport; 512 if (reuseport) { 513 hash = inet_ehashfn(net, daddr, hnum, 514 saddr, sport); 515 matches = 1; 516 } 517 } else if (score == badness && reuseport) { 518 matches++; 519 if (((u64)hash * matches) >> 32 == 0) 520 result = sk; 521 hash = next_pseudo_random32(hash); 522 } 523 } 524 /* 525 * if the nulls value we got at the end of this lookup is 526 * not the expected one, we must restart lookup. 527 * We probably met an item that was moved to another chain. 528 */ 529 if (get_nulls_value(node) != slot) 530 goto begin; 531 532 if (result) { 533 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 534 result = NULL; 535 else if (unlikely(compute_score(result, net, saddr, hnum, sport, 536 daddr, dport, dif) < badness)) { 537 sock_put(result); 538 goto begin; 539 } 540 } 541 rcu_read_unlock(); 542 return result; 543 } 544 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 545 546 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 547 __be16 sport, __be16 dport, 548 struct udp_table *udptable) 549 { 550 struct sock *sk; 551 const struct iphdr *iph = ip_hdr(skb); 552 553 if (unlikely(sk = skb_steal_sock(skb))) 554 return sk; 555 else 556 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, 557 iph->daddr, dport, inet_iif(skb), 558 udptable); 559 } 560 561 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 562 __be32 daddr, __be16 dport, int dif) 563 { 564 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); 565 } 566 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 567 568 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk, 569 __be16 loc_port, __be32 loc_addr, 570 __be16 rmt_port, __be32 rmt_addr, 571 int dif) 572 { 573 struct hlist_nulls_node *node; 574 struct sock *s = sk; 575 unsigned short hnum = ntohs(loc_port); 576 577 sk_nulls_for_each_from(s, node) { 578 struct inet_sock *inet = inet_sk(s); 579 580 if (!net_eq(sock_net(s), net) || 581 udp_sk(s)->udp_port_hash != hnum || 582 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 583 (inet->inet_dport != rmt_port && inet->inet_dport) || 584 (inet->inet_rcv_saddr && 585 inet->inet_rcv_saddr != loc_addr) || 586 ipv6_only_sock(s) || 587 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) 588 continue; 589 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) 590 continue; 591 goto found; 592 } 593 s = NULL; 594 found: 595 return s; 596 } 597 598 /* 599 * This routine is called by the ICMP module when it gets some 600 * sort of error condition. If err < 0 then the socket should 601 * be closed and the error returned to the user. If err > 0 602 * it's just the icmp type << 8 | icmp code. 603 * Header points to the ip header of the error packet. We move 604 * on past this. Then (as it used to claim before adjustment) 605 * header points to the first 8 bytes of the udp header. We need 606 * to find the appropriate port. 607 */ 608 609 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 610 { 611 struct inet_sock *inet; 612 const struct iphdr *iph = (const struct iphdr *)skb->data; 613 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 614 const int type = icmp_hdr(skb)->type; 615 const int code = icmp_hdr(skb)->code; 616 struct sock *sk; 617 int harderr; 618 int err; 619 struct net *net = dev_net(skb->dev); 620 621 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 622 iph->saddr, uh->source, skb->dev->ifindex, udptable); 623 if (sk == NULL) { 624 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 625 return; /* No socket for error */ 626 } 627 628 err = 0; 629 harderr = 0; 630 inet = inet_sk(sk); 631 632 switch (type) { 633 default: 634 case ICMP_TIME_EXCEEDED: 635 err = EHOSTUNREACH; 636 break; 637 case ICMP_SOURCE_QUENCH: 638 goto out; 639 case ICMP_PARAMETERPROB: 640 err = EPROTO; 641 harderr = 1; 642 break; 643 case ICMP_DEST_UNREACH: 644 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 645 ipv4_sk_update_pmtu(skb, sk, info); 646 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 647 err = EMSGSIZE; 648 harderr = 1; 649 break; 650 } 651 goto out; 652 } 653 err = EHOSTUNREACH; 654 if (code <= NR_ICMP_UNREACH) { 655 harderr = icmp_err_convert[code].fatal; 656 err = icmp_err_convert[code].errno; 657 } 658 break; 659 case ICMP_REDIRECT: 660 ipv4_sk_redirect(skb, sk); 661 goto out; 662 } 663 664 /* 665 * RFC1122: OK. Passes ICMP errors back to application, as per 666 * 4.1.3.3. 667 */ 668 if (!inet->recverr) { 669 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 670 goto out; 671 } else 672 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 673 674 sk->sk_err = err; 675 sk->sk_error_report(sk); 676 out: 677 sock_put(sk); 678 } 679 680 void udp_err(struct sk_buff *skb, u32 info) 681 { 682 __udp4_lib_err(skb, info, &udp_table); 683 } 684 685 /* 686 * Throw away all pending data and cancel the corking. Socket is locked. 687 */ 688 void udp_flush_pending_frames(struct sock *sk) 689 { 690 struct udp_sock *up = udp_sk(sk); 691 692 if (up->pending) { 693 up->len = 0; 694 up->pending = 0; 695 ip_flush_pending_frames(sk); 696 } 697 } 698 EXPORT_SYMBOL(udp_flush_pending_frames); 699 700 /** 701 * udp4_hwcsum - handle outgoing HW checksumming 702 * @skb: sk_buff containing the filled-in UDP header 703 * (checksum field must be zeroed out) 704 * @src: source IP address 705 * @dst: destination IP address 706 */ 707 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 708 { 709 struct udphdr *uh = udp_hdr(skb); 710 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 711 int offset = skb_transport_offset(skb); 712 int len = skb->len - offset; 713 int hlen = len; 714 __wsum csum = 0; 715 716 if (!frags) { 717 /* 718 * Only one fragment on the socket. 719 */ 720 skb->csum_start = skb_transport_header(skb) - skb->head; 721 skb->csum_offset = offsetof(struct udphdr, check); 722 uh->check = ~csum_tcpudp_magic(src, dst, len, 723 IPPROTO_UDP, 0); 724 } else { 725 /* 726 * HW-checksum won't work as there are two or more 727 * fragments on the socket so that all csums of sk_buffs 728 * should be together 729 */ 730 do { 731 csum = csum_add(csum, frags->csum); 732 hlen -= frags->len; 733 } while ((frags = frags->next)); 734 735 csum = skb_checksum(skb, offset, hlen, csum); 736 skb->ip_summed = CHECKSUM_NONE; 737 738 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 739 if (uh->check == 0) 740 uh->check = CSUM_MANGLED_0; 741 } 742 } 743 EXPORT_SYMBOL_GPL(udp4_hwcsum); 744 745 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) 746 { 747 struct sock *sk = skb->sk; 748 struct inet_sock *inet = inet_sk(sk); 749 struct udphdr *uh; 750 int err = 0; 751 int is_udplite = IS_UDPLITE(sk); 752 int offset = skb_transport_offset(skb); 753 int len = skb->len - offset; 754 __wsum csum = 0; 755 756 /* 757 * Create a UDP header 758 */ 759 uh = udp_hdr(skb); 760 uh->source = inet->inet_sport; 761 uh->dest = fl4->fl4_dport; 762 uh->len = htons(len); 763 uh->check = 0; 764 765 if (is_udplite) /* UDP-Lite */ 766 csum = udplite_csum(skb); 767 768 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ 769 770 skb->ip_summed = CHECKSUM_NONE; 771 goto send; 772 773 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 774 775 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 776 goto send; 777 778 } else 779 csum = udp_csum(skb); 780 781 /* add protocol-dependent pseudo-header */ 782 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 783 sk->sk_protocol, csum); 784 if (uh->check == 0) 785 uh->check = CSUM_MANGLED_0; 786 787 send: 788 err = ip_send_skb(sock_net(sk), skb); 789 if (err) { 790 if (err == -ENOBUFS && !inet->recverr) { 791 UDP_INC_STATS_USER(sock_net(sk), 792 UDP_MIB_SNDBUFERRORS, is_udplite); 793 err = 0; 794 } 795 } else 796 UDP_INC_STATS_USER(sock_net(sk), 797 UDP_MIB_OUTDATAGRAMS, is_udplite); 798 return err; 799 } 800 801 /* 802 * Push out all pending data as one UDP datagram. Socket is locked. 803 */ 804 int udp_push_pending_frames(struct sock *sk) 805 { 806 struct udp_sock *up = udp_sk(sk); 807 struct inet_sock *inet = inet_sk(sk); 808 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 809 struct sk_buff *skb; 810 int err = 0; 811 812 skb = ip_finish_skb(sk, fl4); 813 if (!skb) 814 goto out; 815 816 err = udp_send_skb(skb, fl4); 817 818 out: 819 up->len = 0; 820 up->pending = 0; 821 return err; 822 } 823 EXPORT_SYMBOL(udp_push_pending_frames); 824 825 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 826 size_t len) 827 { 828 struct inet_sock *inet = inet_sk(sk); 829 struct udp_sock *up = udp_sk(sk); 830 struct flowi4 fl4_stack; 831 struct flowi4 *fl4; 832 int ulen = len; 833 struct ipcm_cookie ipc; 834 struct rtable *rt = NULL; 835 int free = 0; 836 int connected = 0; 837 __be32 daddr, faddr, saddr; 838 __be16 dport; 839 u8 tos; 840 int err, is_udplite = IS_UDPLITE(sk); 841 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 842 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 843 struct sk_buff *skb; 844 struct ip_options_data opt_copy; 845 846 if (len > 0xFFFF) 847 return -EMSGSIZE; 848 849 /* 850 * Check the flags. 851 */ 852 853 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 854 return -EOPNOTSUPP; 855 856 ipc.opt = NULL; 857 ipc.tx_flags = 0; 858 ipc.ttl = 0; 859 ipc.tos = -1; 860 861 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 862 863 fl4 = &inet->cork.fl.u.ip4; 864 if (up->pending) { 865 /* 866 * There are pending frames. 867 * The socket lock must be held while it's corked. 868 */ 869 lock_sock(sk); 870 if (likely(up->pending)) { 871 if (unlikely(up->pending != AF_INET)) { 872 release_sock(sk); 873 return -EINVAL; 874 } 875 goto do_append_data; 876 } 877 release_sock(sk); 878 } 879 ulen += sizeof(struct udphdr); 880 881 /* 882 * Get and verify the address. 883 */ 884 if (msg->msg_name) { 885 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name; 886 if (msg->msg_namelen < sizeof(*usin)) 887 return -EINVAL; 888 if (usin->sin_family != AF_INET) { 889 if (usin->sin_family != AF_UNSPEC) 890 return -EAFNOSUPPORT; 891 } 892 893 daddr = usin->sin_addr.s_addr; 894 dport = usin->sin_port; 895 if (dport == 0) 896 return -EINVAL; 897 } else { 898 if (sk->sk_state != TCP_ESTABLISHED) 899 return -EDESTADDRREQ; 900 daddr = inet->inet_daddr; 901 dport = inet->inet_dport; 902 /* Open fast path for connected socket. 903 Route will not be used, if at least one option is set. 904 */ 905 connected = 1; 906 } 907 ipc.addr = inet->inet_saddr; 908 909 ipc.oif = sk->sk_bound_dev_if; 910 911 sock_tx_timestamp(sk, &ipc.tx_flags); 912 913 if (msg->msg_controllen) { 914 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 915 if (err) 916 return err; 917 if (ipc.opt) 918 free = 1; 919 connected = 0; 920 } 921 if (!ipc.opt) { 922 struct ip_options_rcu *inet_opt; 923 924 rcu_read_lock(); 925 inet_opt = rcu_dereference(inet->inet_opt); 926 if (inet_opt) { 927 memcpy(&opt_copy, inet_opt, 928 sizeof(*inet_opt) + inet_opt->opt.optlen); 929 ipc.opt = &opt_copy.opt; 930 } 931 rcu_read_unlock(); 932 } 933 934 saddr = ipc.addr; 935 ipc.addr = faddr = daddr; 936 937 if (ipc.opt && ipc.opt->opt.srr) { 938 if (!daddr) 939 return -EINVAL; 940 faddr = ipc.opt->opt.faddr; 941 connected = 0; 942 } 943 tos = get_rttos(&ipc, inet); 944 if (sock_flag(sk, SOCK_LOCALROUTE) || 945 (msg->msg_flags & MSG_DONTROUTE) || 946 (ipc.opt && ipc.opt->opt.is_strictroute)) { 947 tos |= RTO_ONLINK; 948 connected = 0; 949 } 950 951 if (ipv4_is_multicast(daddr)) { 952 if (!ipc.oif) 953 ipc.oif = inet->mc_index; 954 if (!saddr) 955 saddr = inet->mc_addr; 956 connected = 0; 957 } else if (!ipc.oif) 958 ipc.oif = inet->uc_index; 959 960 if (connected) 961 rt = (struct rtable *)sk_dst_check(sk, 0); 962 963 if (rt == NULL) { 964 struct net *net = sock_net(sk); 965 966 fl4 = &fl4_stack; 967 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, 968 RT_SCOPE_UNIVERSE, sk->sk_protocol, 969 inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP, 970 faddr, saddr, dport, inet->inet_sport); 971 972 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 973 rt = ip_route_output_flow(net, fl4, sk); 974 if (IS_ERR(rt)) { 975 err = PTR_ERR(rt); 976 rt = NULL; 977 if (err == -ENETUNREACH) 978 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 979 goto out; 980 } 981 982 err = -EACCES; 983 if ((rt->rt_flags & RTCF_BROADCAST) && 984 !sock_flag(sk, SOCK_BROADCAST)) 985 goto out; 986 if (connected) 987 sk_dst_set(sk, dst_clone(&rt->dst)); 988 } 989 990 if (msg->msg_flags&MSG_CONFIRM) 991 goto do_confirm; 992 back_from_confirm: 993 994 saddr = fl4->saddr; 995 if (!ipc.addr) 996 daddr = ipc.addr = fl4->daddr; 997 998 /* Lockless fast path for the non-corking case. */ 999 if (!corkreq) { 1000 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen, 1001 sizeof(struct udphdr), &ipc, &rt, 1002 msg->msg_flags); 1003 err = PTR_ERR(skb); 1004 if (!IS_ERR_OR_NULL(skb)) 1005 err = udp_send_skb(skb, fl4); 1006 goto out; 1007 } 1008 1009 lock_sock(sk); 1010 if (unlikely(up->pending)) { 1011 /* The socket is already corked while preparing it. */ 1012 /* ... which is an evident application bug. --ANK */ 1013 release_sock(sk); 1014 1015 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n")); 1016 err = -EINVAL; 1017 goto out; 1018 } 1019 /* 1020 * Now cork the socket to pend data. 1021 */ 1022 fl4 = &inet->cork.fl.u.ip4; 1023 fl4->daddr = daddr; 1024 fl4->saddr = saddr; 1025 fl4->fl4_dport = dport; 1026 fl4->fl4_sport = inet->inet_sport; 1027 up->pending = AF_INET; 1028 1029 do_append_data: 1030 up->len += ulen; 1031 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen, 1032 sizeof(struct udphdr), &ipc, &rt, 1033 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1034 if (err) 1035 udp_flush_pending_frames(sk); 1036 else if (!corkreq) 1037 err = udp_push_pending_frames(sk); 1038 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1039 up->pending = 0; 1040 release_sock(sk); 1041 1042 out: 1043 ip_rt_put(rt); 1044 if (free) 1045 kfree(ipc.opt); 1046 if (!err) 1047 return len; 1048 /* 1049 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1050 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1051 * we don't have a good statistic (IpOutDiscards but it can be too many 1052 * things). We could add another new stat but at least for now that 1053 * seems like overkill. 1054 */ 1055 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1056 UDP_INC_STATS_USER(sock_net(sk), 1057 UDP_MIB_SNDBUFERRORS, is_udplite); 1058 } 1059 return err; 1060 1061 do_confirm: 1062 dst_confirm(&rt->dst); 1063 if (!(msg->msg_flags&MSG_PROBE) || len) 1064 goto back_from_confirm; 1065 err = 0; 1066 goto out; 1067 } 1068 EXPORT_SYMBOL(udp_sendmsg); 1069 1070 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1071 size_t size, int flags) 1072 { 1073 struct inet_sock *inet = inet_sk(sk); 1074 struct udp_sock *up = udp_sk(sk); 1075 int ret; 1076 1077 if (!up->pending) { 1078 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1079 1080 /* Call udp_sendmsg to specify destination address which 1081 * sendpage interface can't pass. 1082 * This will succeed only when the socket is connected. 1083 */ 1084 ret = udp_sendmsg(NULL, sk, &msg, 0); 1085 if (ret < 0) 1086 return ret; 1087 } 1088 1089 lock_sock(sk); 1090 1091 if (unlikely(!up->pending)) { 1092 release_sock(sk); 1093 1094 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n")); 1095 return -EINVAL; 1096 } 1097 1098 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1099 page, offset, size, flags); 1100 if (ret == -EOPNOTSUPP) { 1101 release_sock(sk); 1102 return sock_no_sendpage(sk->sk_socket, page, offset, 1103 size, flags); 1104 } 1105 if (ret < 0) { 1106 udp_flush_pending_frames(sk); 1107 goto out; 1108 } 1109 1110 up->len += size; 1111 if (!(up->corkflag || (flags&MSG_MORE))) 1112 ret = udp_push_pending_frames(sk); 1113 if (!ret) 1114 ret = size; 1115 out: 1116 release_sock(sk); 1117 return ret; 1118 } 1119 1120 1121 /** 1122 * first_packet_length - return length of first packet in receive queue 1123 * @sk: socket 1124 * 1125 * Drops all bad checksum frames, until a valid one is found. 1126 * Returns the length of found skb, or 0 if none is found. 1127 */ 1128 static unsigned int first_packet_length(struct sock *sk) 1129 { 1130 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue; 1131 struct sk_buff *skb; 1132 unsigned int res; 1133 1134 __skb_queue_head_init(&list_kill); 1135 1136 spin_lock_bh(&rcvq->lock); 1137 while ((skb = skb_peek(rcvq)) != NULL && 1138 udp_lib_checksum_complete(skb)) { 1139 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, 1140 IS_UDPLITE(sk)); 1141 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1142 IS_UDPLITE(sk)); 1143 atomic_inc(&sk->sk_drops); 1144 __skb_unlink(skb, rcvq); 1145 __skb_queue_tail(&list_kill, skb); 1146 } 1147 res = skb ? skb->len : 0; 1148 spin_unlock_bh(&rcvq->lock); 1149 1150 if (!skb_queue_empty(&list_kill)) { 1151 bool slow = lock_sock_fast(sk); 1152 1153 __skb_queue_purge(&list_kill); 1154 sk_mem_reclaim_partial(sk); 1155 unlock_sock_fast(sk, slow); 1156 } 1157 return res; 1158 } 1159 1160 /* 1161 * IOCTL requests applicable to the UDP protocol 1162 */ 1163 1164 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1165 { 1166 switch (cmd) { 1167 case SIOCOUTQ: 1168 { 1169 int amount = sk_wmem_alloc_get(sk); 1170 1171 return put_user(amount, (int __user *)arg); 1172 } 1173 1174 case SIOCINQ: 1175 { 1176 unsigned int amount = first_packet_length(sk); 1177 1178 if (amount) 1179 /* 1180 * We will only return the amount 1181 * of this packet since that is all 1182 * that will be read. 1183 */ 1184 amount -= sizeof(struct udphdr); 1185 1186 return put_user(amount, (int __user *)arg); 1187 } 1188 1189 default: 1190 return -ENOIOCTLCMD; 1191 } 1192 1193 return 0; 1194 } 1195 EXPORT_SYMBOL(udp_ioctl); 1196 1197 /* 1198 * This should be easy, if there is something there we 1199 * return it, otherwise we block. 1200 */ 1201 1202 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1203 size_t len, int noblock, int flags, int *addr_len) 1204 { 1205 struct inet_sock *inet = inet_sk(sk); 1206 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 1207 struct sk_buff *skb; 1208 unsigned int ulen, copied; 1209 int peeked, off = 0; 1210 int err; 1211 int is_udplite = IS_UDPLITE(sk); 1212 bool slow; 1213 1214 /* 1215 * Check any passed addresses 1216 */ 1217 if (addr_len) 1218 *addr_len = sizeof(*sin); 1219 1220 if (flags & MSG_ERRQUEUE) 1221 return ip_recv_error(sk, msg, len); 1222 1223 try_again: 1224 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), 1225 &peeked, &off, &err); 1226 if (!skb) 1227 goto out; 1228 1229 ulen = skb->len - sizeof(struct udphdr); 1230 copied = len; 1231 if (copied > ulen) 1232 copied = ulen; 1233 else if (copied < ulen) 1234 msg->msg_flags |= MSG_TRUNC; 1235 1236 /* 1237 * If checksum is needed at all, try to do it while copying the 1238 * data. If the data is truncated, or if we only want a partial 1239 * coverage checksum (UDP-Lite), do it before the copy. 1240 */ 1241 1242 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { 1243 if (udp_lib_checksum_complete(skb)) 1244 goto csum_copy_err; 1245 } 1246 1247 if (skb_csum_unnecessary(skb)) 1248 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), 1249 msg->msg_iov, copied); 1250 else { 1251 err = skb_copy_and_csum_datagram_iovec(skb, 1252 sizeof(struct udphdr), 1253 msg->msg_iov); 1254 1255 if (err == -EINVAL) 1256 goto csum_copy_err; 1257 } 1258 1259 if (unlikely(err)) { 1260 trace_kfree_skb(skb, udp_recvmsg); 1261 if (!peeked) { 1262 atomic_inc(&sk->sk_drops); 1263 UDP_INC_STATS_USER(sock_net(sk), 1264 UDP_MIB_INERRORS, is_udplite); 1265 } 1266 goto out_free; 1267 } 1268 1269 if (!peeked) 1270 UDP_INC_STATS_USER(sock_net(sk), 1271 UDP_MIB_INDATAGRAMS, is_udplite); 1272 1273 sock_recv_ts_and_drops(msg, sk, skb); 1274 1275 /* Copy the address. */ 1276 if (sin) { 1277 sin->sin_family = AF_INET; 1278 sin->sin_port = udp_hdr(skb)->source; 1279 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1280 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1281 } 1282 if (inet->cmsg_flags) 1283 ip_cmsg_recv(msg, skb); 1284 1285 err = copied; 1286 if (flags & MSG_TRUNC) 1287 err = ulen; 1288 1289 out_free: 1290 skb_free_datagram_locked(sk, skb); 1291 out: 1292 return err; 1293 1294 csum_copy_err: 1295 slow = lock_sock_fast(sk); 1296 if (!skb_kill_datagram(sk, skb, flags)) { 1297 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1298 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1299 } 1300 unlock_sock_fast(sk, slow); 1301 1302 if (noblock) 1303 return -EAGAIN; 1304 1305 /* starting over for a new packet */ 1306 msg->msg_flags &= ~MSG_TRUNC; 1307 goto try_again; 1308 } 1309 1310 1311 int udp_disconnect(struct sock *sk, int flags) 1312 { 1313 struct inet_sock *inet = inet_sk(sk); 1314 /* 1315 * 1003.1g - break association. 1316 */ 1317 1318 sk->sk_state = TCP_CLOSE; 1319 inet->inet_daddr = 0; 1320 inet->inet_dport = 0; 1321 sock_rps_reset_rxhash(sk); 1322 sk->sk_bound_dev_if = 0; 1323 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1324 inet_reset_saddr(sk); 1325 1326 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1327 sk->sk_prot->unhash(sk); 1328 inet->inet_sport = 0; 1329 } 1330 sk_dst_reset(sk); 1331 return 0; 1332 } 1333 EXPORT_SYMBOL(udp_disconnect); 1334 1335 void udp_lib_unhash(struct sock *sk) 1336 { 1337 if (sk_hashed(sk)) { 1338 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1339 struct udp_hslot *hslot, *hslot2; 1340 1341 hslot = udp_hashslot(udptable, sock_net(sk), 1342 udp_sk(sk)->udp_port_hash); 1343 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1344 1345 spin_lock_bh(&hslot->lock); 1346 if (sk_nulls_del_node_init_rcu(sk)) { 1347 hslot->count--; 1348 inet_sk(sk)->inet_num = 0; 1349 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1350 1351 spin_lock(&hslot2->lock); 1352 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1353 hslot2->count--; 1354 spin_unlock(&hslot2->lock); 1355 } 1356 spin_unlock_bh(&hslot->lock); 1357 } 1358 } 1359 EXPORT_SYMBOL(udp_lib_unhash); 1360 1361 /* 1362 * inet_rcv_saddr was changed, we must rehash secondary hash 1363 */ 1364 void udp_lib_rehash(struct sock *sk, u16 newhash) 1365 { 1366 if (sk_hashed(sk)) { 1367 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1368 struct udp_hslot *hslot, *hslot2, *nhslot2; 1369 1370 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1371 nhslot2 = udp_hashslot2(udptable, newhash); 1372 udp_sk(sk)->udp_portaddr_hash = newhash; 1373 if (hslot2 != nhslot2) { 1374 hslot = udp_hashslot(udptable, sock_net(sk), 1375 udp_sk(sk)->udp_port_hash); 1376 /* we must lock primary chain too */ 1377 spin_lock_bh(&hslot->lock); 1378 1379 spin_lock(&hslot2->lock); 1380 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1381 hslot2->count--; 1382 spin_unlock(&hslot2->lock); 1383 1384 spin_lock(&nhslot2->lock); 1385 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1386 &nhslot2->head); 1387 nhslot2->count++; 1388 spin_unlock(&nhslot2->lock); 1389 1390 spin_unlock_bh(&hslot->lock); 1391 } 1392 } 1393 } 1394 EXPORT_SYMBOL(udp_lib_rehash); 1395 1396 static void udp_v4_rehash(struct sock *sk) 1397 { 1398 u16 new_hash = udp4_portaddr_hash(sock_net(sk), 1399 inet_sk(sk)->inet_rcv_saddr, 1400 inet_sk(sk)->inet_num); 1401 udp_lib_rehash(sk, new_hash); 1402 } 1403 1404 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1405 { 1406 int rc; 1407 1408 if (inet_sk(sk)->inet_daddr) 1409 sock_rps_save_rxhash(sk, skb); 1410 1411 rc = sock_queue_rcv_skb(sk, skb); 1412 if (rc < 0) { 1413 int is_udplite = IS_UDPLITE(sk); 1414 1415 /* Note that an ENOMEM error is charged twice */ 1416 if (rc == -ENOMEM) 1417 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1418 is_udplite); 1419 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1420 kfree_skb(skb); 1421 trace_udp_fail_queue_rcv_skb(rc, sk); 1422 return -1; 1423 } 1424 1425 return 0; 1426 1427 } 1428 1429 static struct static_key udp_encap_needed __read_mostly; 1430 void udp_encap_enable(void) 1431 { 1432 if (!static_key_enabled(&udp_encap_needed)) 1433 static_key_slow_inc(&udp_encap_needed); 1434 } 1435 EXPORT_SYMBOL(udp_encap_enable); 1436 1437 /* returns: 1438 * -1: error 1439 * 0: success 1440 * >0: "udp encap" protocol resubmission 1441 * 1442 * Note that in the success and error cases, the skb is assumed to 1443 * have either been requeued or freed. 1444 */ 1445 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1446 { 1447 struct udp_sock *up = udp_sk(sk); 1448 int rc; 1449 int is_udplite = IS_UDPLITE(sk); 1450 1451 /* 1452 * Charge it to the socket, dropping if the queue is full. 1453 */ 1454 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1455 goto drop; 1456 nf_reset(skb); 1457 1458 if (static_key_false(&udp_encap_needed) && up->encap_type) { 1459 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 1460 1461 /* 1462 * This is an encapsulation socket so pass the skb to 1463 * the socket's udp_encap_rcv() hook. Otherwise, just 1464 * fall through and pass this up the UDP socket. 1465 * up->encap_rcv() returns the following value: 1466 * =0 if skb was successfully passed to the encap 1467 * handler or was discarded by it. 1468 * >0 if skb should be passed on to UDP. 1469 * <0 if skb should be resubmitted as proto -N 1470 */ 1471 1472 /* if we're overly short, let UDP handle it */ 1473 encap_rcv = ACCESS_ONCE(up->encap_rcv); 1474 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) { 1475 int ret; 1476 1477 ret = encap_rcv(sk, skb); 1478 if (ret <= 0) { 1479 UDP_INC_STATS_BH(sock_net(sk), 1480 UDP_MIB_INDATAGRAMS, 1481 is_udplite); 1482 return -ret; 1483 } 1484 } 1485 1486 /* FALLTHROUGH -- it's a UDP Packet */ 1487 } 1488 1489 /* 1490 * UDP-Lite specific tests, ignored on UDP sockets 1491 */ 1492 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1493 1494 /* 1495 * MIB statistics other than incrementing the error count are 1496 * disabled for the following two types of errors: these depend 1497 * on the application settings, not on the functioning of the 1498 * protocol stack as such. 1499 * 1500 * RFC 3828 here recommends (sec 3.3): "There should also be a 1501 * way ... to ... at least let the receiving application block 1502 * delivery of packets with coverage values less than a value 1503 * provided by the application." 1504 */ 1505 if (up->pcrlen == 0) { /* full coverage was set */ 1506 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n", 1507 UDP_SKB_CB(skb)->cscov, skb->len); 1508 goto drop; 1509 } 1510 /* The next case involves violating the min. coverage requested 1511 * by the receiver. This is subtle: if receiver wants x and x is 1512 * greater than the buffersize/MTU then receiver will complain 1513 * that it wants x while sender emits packets of smaller size y. 1514 * Therefore the above ...()->partial_cov statement is essential. 1515 */ 1516 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1517 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n", 1518 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1519 goto drop; 1520 } 1521 } 1522 1523 if (rcu_access_pointer(sk->sk_filter) && 1524 udp_lib_checksum_complete(skb)) 1525 goto csum_error; 1526 1527 1528 if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) 1529 goto drop; 1530 1531 rc = 0; 1532 1533 ipv4_pktinfo_prepare(skb); 1534 bh_lock_sock(sk); 1535 if (!sock_owned_by_user(sk)) 1536 rc = __udp_queue_rcv_skb(sk, skb); 1537 else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) { 1538 bh_unlock_sock(sk); 1539 goto drop; 1540 } 1541 bh_unlock_sock(sk); 1542 1543 return rc; 1544 1545 csum_error: 1546 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1547 drop: 1548 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1549 atomic_inc(&sk->sk_drops); 1550 kfree_skb(skb); 1551 return -1; 1552 } 1553 1554 1555 static void flush_stack(struct sock **stack, unsigned int count, 1556 struct sk_buff *skb, unsigned int final) 1557 { 1558 unsigned int i; 1559 struct sk_buff *skb1 = NULL; 1560 struct sock *sk; 1561 1562 for (i = 0; i < count; i++) { 1563 sk = stack[i]; 1564 if (likely(skb1 == NULL)) 1565 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); 1566 1567 if (!skb1) { 1568 atomic_inc(&sk->sk_drops); 1569 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1570 IS_UDPLITE(sk)); 1571 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1572 IS_UDPLITE(sk)); 1573 } 1574 1575 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0) 1576 skb1 = NULL; 1577 } 1578 if (unlikely(skb1)) 1579 kfree_skb(skb1); 1580 } 1581 1582 /* 1583 * Multicasts and broadcasts go to each listener. 1584 * 1585 * Note: called only from the BH handler context. 1586 */ 1587 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 1588 struct udphdr *uh, 1589 __be32 saddr, __be32 daddr, 1590 struct udp_table *udptable) 1591 { 1592 struct sock *sk, *stack[256 / sizeof(struct sock *)]; 1593 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest)); 1594 int dif; 1595 unsigned int i, count = 0; 1596 1597 spin_lock(&hslot->lock); 1598 sk = sk_nulls_head(&hslot->head); 1599 dif = skb->dev->ifindex; 1600 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); 1601 while (sk) { 1602 stack[count++] = sk; 1603 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest, 1604 daddr, uh->source, saddr, dif); 1605 if (unlikely(count == ARRAY_SIZE(stack))) { 1606 if (!sk) 1607 break; 1608 flush_stack(stack, count, skb, ~0); 1609 count = 0; 1610 } 1611 } 1612 /* 1613 * before releasing chain lock, we must take a reference on sockets 1614 */ 1615 for (i = 0; i < count; i++) 1616 sock_hold(stack[i]); 1617 1618 spin_unlock(&hslot->lock); 1619 1620 /* 1621 * do the slow work with no lock held 1622 */ 1623 if (count) { 1624 flush_stack(stack, count, skb, count - 1); 1625 1626 for (i = 0; i < count; i++) 1627 sock_put(stack[i]); 1628 } else { 1629 kfree_skb(skb); 1630 } 1631 return 0; 1632 } 1633 1634 /* Initialize UDP checksum. If exited with zero value (success), 1635 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1636 * Otherwise, csum completion requires chacksumming packet body, 1637 * including udp header and folding it to skb->csum. 1638 */ 1639 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 1640 int proto) 1641 { 1642 const struct iphdr *iph; 1643 int err; 1644 1645 UDP_SKB_CB(skb)->partial_cov = 0; 1646 UDP_SKB_CB(skb)->cscov = skb->len; 1647 1648 if (proto == IPPROTO_UDPLITE) { 1649 err = udplite_checksum_init(skb, uh); 1650 if (err) 1651 return err; 1652 } 1653 1654 iph = ip_hdr(skb); 1655 if (uh->check == 0) { 1656 skb->ip_summed = CHECKSUM_UNNECESSARY; 1657 } else if (skb->ip_summed == CHECKSUM_COMPLETE) { 1658 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 1659 proto, skb->csum)) 1660 skb->ip_summed = CHECKSUM_UNNECESSARY; 1661 } 1662 if (!skb_csum_unnecessary(skb)) 1663 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, 1664 skb->len, proto, 0); 1665 /* Probably, we should checksum udp header (it should be in cache 1666 * in any case) and data in tiny packets (< rx copybreak). 1667 */ 1668 1669 return 0; 1670 } 1671 1672 /* 1673 * All we need to do is get the socket, and then do a checksum. 1674 */ 1675 1676 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 1677 int proto) 1678 { 1679 struct sock *sk; 1680 struct udphdr *uh; 1681 unsigned short ulen; 1682 struct rtable *rt = skb_rtable(skb); 1683 __be32 saddr, daddr; 1684 struct net *net = dev_net(skb->dev); 1685 1686 /* 1687 * Validate the packet. 1688 */ 1689 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1690 goto drop; /* No space for header. */ 1691 1692 uh = udp_hdr(skb); 1693 ulen = ntohs(uh->len); 1694 saddr = ip_hdr(skb)->saddr; 1695 daddr = ip_hdr(skb)->daddr; 1696 1697 if (ulen > skb->len) 1698 goto short_packet; 1699 1700 if (proto == IPPROTO_UDP) { 1701 /* UDP validates ulen. */ 1702 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1703 goto short_packet; 1704 uh = udp_hdr(skb); 1705 } 1706 1707 if (udp4_csum_init(skb, uh, proto)) 1708 goto csum_error; 1709 1710 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1711 return __udp4_lib_mcast_deliver(net, skb, uh, 1712 saddr, daddr, udptable); 1713 1714 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 1715 1716 if (sk != NULL) { 1717 int ret; 1718 1719 sk_mark_napi_id(sk, skb); 1720 ret = udp_queue_rcv_skb(sk, skb); 1721 sock_put(sk); 1722 1723 /* a return value > 0 means to resubmit the input, but 1724 * it wants the return to be -protocol, or 0 1725 */ 1726 if (ret > 0) 1727 return -ret; 1728 return 0; 1729 } 1730 1731 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1732 goto drop; 1733 nf_reset(skb); 1734 1735 /* No socket. Drop packet silently, if checksum is wrong */ 1736 if (udp_lib_checksum_complete(skb)) 1737 goto csum_error; 1738 1739 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 1740 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1741 1742 /* 1743 * Hmm. We got an UDP packet to a port to which we 1744 * don't wanna listen. Ignore it. 1745 */ 1746 kfree_skb(skb); 1747 return 0; 1748 1749 short_packet: 1750 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 1751 proto == IPPROTO_UDPLITE ? "Lite" : "", 1752 &saddr, ntohs(uh->source), 1753 ulen, skb->len, 1754 &daddr, ntohs(uh->dest)); 1755 goto drop; 1756 1757 csum_error: 1758 /* 1759 * RFC1122: OK. Discards the bad packet silently (as far as 1760 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1761 */ 1762 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 1763 proto == IPPROTO_UDPLITE ? "Lite" : "", 1764 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 1765 ulen); 1766 UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 1767 drop: 1768 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1769 kfree_skb(skb); 1770 return 0; 1771 } 1772 1773 int udp_rcv(struct sk_buff *skb) 1774 { 1775 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 1776 } 1777 1778 void udp_destroy_sock(struct sock *sk) 1779 { 1780 struct udp_sock *up = udp_sk(sk); 1781 bool slow = lock_sock_fast(sk); 1782 udp_flush_pending_frames(sk); 1783 unlock_sock_fast(sk, slow); 1784 if (static_key_false(&udp_encap_needed) && up->encap_type) { 1785 void (*encap_destroy)(struct sock *sk); 1786 encap_destroy = ACCESS_ONCE(up->encap_destroy); 1787 if (encap_destroy) 1788 encap_destroy(sk); 1789 } 1790 } 1791 1792 /* 1793 * Socket option code for UDP 1794 */ 1795 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 1796 char __user *optval, unsigned int optlen, 1797 int (*push_pending_frames)(struct sock *)) 1798 { 1799 struct udp_sock *up = udp_sk(sk); 1800 int val; 1801 int err = 0; 1802 int is_udplite = IS_UDPLITE(sk); 1803 1804 if (optlen < sizeof(int)) 1805 return -EINVAL; 1806 1807 if (get_user(val, (int __user *)optval)) 1808 return -EFAULT; 1809 1810 switch (optname) { 1811 case UDP_CORK: 1812 if (val != 0) { 1813 up->corkflag = 1; 1814 } else { 1815 up->corkflag = 0; 1816 lock_sock(sk); 1817 (*push_pending_frames)(sk); 1818 release_sock(sk); 1819 } 1820 break; 1821 1822 case UDP_ENCAP: 1823 switch (val) { 1824 case 0: 1825 case UDP_ENCAP_ESPINUDP: 1826 case UDP_ENCAP_ESPINUDP_NON_IKE: 1827 up->encap_rcv = xfrm4_udp_encap_rcv; 1828 /* FALLTHROUGH */ 1829 case UDP_ENCAP_L2TPINUDP: 1830 up->encap_type = val; 1831 udp_encap_enable(); 1832 break; 1833 default: 1834 err = -ENOPROTOOPT; 1835 break; 1836 } 1837 break; 1838 1839 /* 1840 * UDP-Lite's partial checksum coverage (RFC 3828). 1841 */ 1842 /* The sender sets actual checksum coverage length via this option. 1843 * The case coverage > packet length is handled by send module. */ 1844 case UDPLITE_SEND_CSCOV: 1845 if (!is_udplite) /* Disable the option on UDP sockets */ 1846 return -ENOPROTOOPT; 1847 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 1848 val = 8; 1849 else if (val > USHRT_MAX) 1850 val = USHRT_MAX; 1851 up->pcslen = val; 1852 up->pcflag |= UDPLITE_SEND_CC; 1853 break; 1854 1855 /* The receiver specifies a minimum checksum coverage value. To make 1856 * sense, this should be set to at least 8 (as done below). If zero is 1857 * used, this again means full checksum coverage. */ 1858 case UDPLITE_RECV_CSCOV: 1859 if (!is_udplite) /* Disable the option on UDP sockets */ 1860 return -ENOPROTOOPT; 1861 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 1862 val = 8; 1863 else if (val > USHRT_MAX) 1864 val = USHRT_MAX; 1865 up->pcrlen = val; 1866 up->pcflag |= UDPLITE_RECV_CC; 1867 break; 1868 1869 default: 1870 err = -ENOPROTOOPT; 1871 break; 1872 } 1873 1874 return err; 1875 } 1876 EXPORT_SYMBOL(udp_lib_setsockopt); 1877 1878 int udp_setsockopt(struct sock *sk, int level, int optname, 1879 char __user *optval, unsigned int optlen) 1880 { 1881 if (level == SOL_UDP || level == SOL_UDPLITE) 1882 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1883 udp_push_pending_frames); 1884 return ip_setsockopt(sk, level, optname, optval, optlen); 1885 } 1886 1887 #ifdef CONFIG_COMPAT 1888 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 1889 char __user *optval, unsigned int optlen) 1890 { 1891 if (level == SOL_UDP || level == SOL_UDPLITE) 1892 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1893 udp_push_pending_frames); 1894 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 1895 } 1896 #endif 1897 1898 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 1899 char __user *optval, int __user *optlen) 1900 { 1901 struct udp_sock *up = udp_sk(sk); 1902 int val, len; 1903 1904 if (get_user(len, optlen)) 1905 return -EFAULT; 1906 1907 len = min_t(unsigned int, len, sizeof(int)); 1908 1909 if (len < 0) 1910 return -EINVAL; 1911 1912 switch (optname) { 1913 case UDP_CORK: 1914 val = up->corkflag; 1915 break; 1916 1917 case UDP_ENCAP: 1918 val = up->encap_type; 1919 break; 1920 1921 /* The following two cannot be changed on UDP sockets, the return is 1922 * always 0 (which corresponds to the full checksum coverage of UDP). */ 1923 case UDPLITE_SEND_CSCOV: 1924 val = up->pcslen; 1925 break; 1926 1927 case UDPLITE_RECV_CSCOV: 1928 val = up->pcrlen; 1929 break; 1930 1931 default: 1932 return -ENOPROTOOPT; 1933 } 1934 1935 if (put_user(len, optlen)) 1936 return -EFAULT; 1937 if (copy_to_user(optval, &val, len)) 1938 return -EFAULT; 1939 return 0; 1940 } 1941 EXPORT_SYMBOL(udp_lib_getsockopt); 1942 1943 int udp_getsockopt(struct sock *sk, int level, int optname, 1944 char __user *optval, int __user *optlen) 1945 { 1946 if (level == SOL_UDP || level == SOL_UDPLITE) 1947 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1948 return ip_getsockopt(sk, level, optname, optval, optlen); 1949 } 1950 1951 #ifdef CONFIG_COMPAT 1952 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 1953 char __user *optval, int __user *optlen) 1954 { 1955 if (level == SOL_UDP || level == SOL_UDPLITE) 1956 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1957 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 1958 } 1959 #endif 1960 /** 1961 * udp_poll - wait for a UDP event. 1962 * @file - file struct 1963 * @sock - socket 1964 * @wait - poll table 1965 * 1966 * This is same as datagram poll, except for the special case of 1967 * blocking sockets. If application is using a blocking fd 1968 * and a packet with checksum error is in the queue; 1969 * then it could get return from select indicating data available 1970 * but then block when reading it. Add special case code 1971 * to work around these arguably broken applications. 1972 */ 1973 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 1974 { 1975 unsigned int mask = datagram_poll(file, sock, wait); 1976 struct sock *sk = sock->sk; 1977 1978 sock_rps_record_flow(sk); 1979 1980 /* Check for false positives due to checksum errors */ 1981 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 1982 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk)) 1983 mask &= ~(POLLIN | POLLRDNORM); 1984 1985 return mask; 1986 1987 } 1988 EXPORT_SYMBOL(udp_poll); 1989 1990 struct proto udp_prot = { 1991 .name = "UDP", 1992 .owner = THIS_MODULE, 1993 .close = udp_lib_close, 1994 .connect = ip4_datagram_connect, 1995 .disconnect = udp_disconnect, 1996 .ioctl = udp_ioctl, 1997 .destroy = udp_destroy_sock, 1998 .setsockopt = udp_setsockopt, 1999 .getsockopt = udp_getsockopt, 2000 .sendmsg = udp_sendmsg, 2001 .recvmsg = udp_recvmsg, 2002 .sendpage = udp_sendpage, 2003 .backlog_rcv = __udp_queue_rcv_skb, 2004 .release_cb = ip4_datagram_release_cb, 2005 .hash = udp_lib_hash, 2006 .unhash = udp_lib_unhash, 2007 .rehash = udp_v4_rehash, 2008 .get_port = udp_v4_get_port, 2009 .memory_allocated = &udp_memory_allocated, 2010 .sysctl_mem = sysctl_udp_mem, 2011 .sysctl_wmem = &sysctl_udp_wmem_min, 2012 .sysctl_rmem = &sysctl_udp_rmem_min, 2013 .obj_size = sizeof(struct udp_sock), 2014 .slab_flags = SLAB_DESTROY_BY_RCU, 2015 .h.udp_table = &udp_table, 2016 #ifdef CONFIG_COMPAT 2017 .compat_setsockopt = compat_udp_setsockopt, 2018 .compat_getsockopt = compat_udp_getsockopt, 2019 #endif 2020 .clear_sk = sk_prot_clear_portaddr_nulls, 2021 }; 2022 EXPORT_SYMBOL(udp_prot); 2023 2024 /* ------------------------------------------------------------------------ */ 2025 #ifdef CONFIG_PROC_FS 2026 2027 static struct sock *udp_get_first(struct seq_file *seq, int start) 2028 { 2029 struct sock *sk; 2030 struct udp_iter_state *state = seq->private; 2031 struct net *net = seq_file_net(seq); 2032 2033 for (state->bucket = start; state->bucket <= state->udp_table->mask; 2034 ++state->bucket) { 2035 struct hlist_nulls_node *node; 2036 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; 2037 2038 if (hlist_nulls_empty(&hslot->head)) 2039 continue; 2040 2041 spin_lock_bh(&hslot->lock); 2042 sk_nulls_for_each(sk, node, &hslot->head) { 2043 if (!net_eq(sock_net(sk), net)) 2044 continue; 2045 if (sk->sk_family == state->family) 2046 goto found; 2047 } 2048 spin_unlock_bh(&hslot->lock); 2049 } 2050 sk = NULL; 2051 found: 2052 return sk; 2053 } 2054 2055 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2056 { 2057 struct udp_iter_state *state = seq->private; 2058 struct net *net = seq_file_net(seq); 2059 2060 do { 2061 sk = sk_nulls_next(sk); 2062 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); 2063 2064 if (!sk) { 2065 if (state->bucket <= state->udp_table->mask) 2066 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2067 return udp_get_first(seq, state->bucket + 1); 2068 } 2069 return sk; 2070 } 2071 2072 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2073 { 2074 struct sock *sk = udp_get_first(seq, 0); 2075 2076 if (sk) 2077 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2078 --pos; 2079 return pos ? NULL : sk; 2080 } 2081 2082 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2083 { 2084 struct udp_iter_state *state = seq->private; 2085 state->bucket = MAX_UDP_PORTS; 2086 2087 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2088 } 2089 2090 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2091 { 2092 struct sock *sk; 2093 2094 if (v == SEQ_START_TOKEN) 2095 sk = udp_get_idx(seq, 0); 2096 else 2097 sk = udp_get_next(seq, v); 2098 2099 ++*pos; 2100 return sk; 2101 } 2102 2103 static void udp_seq_stop(struct seq_file *seq, void *v) 2104 { 2105 struct udp_iter_state *state = seq->private; 2106 2107 if (state->bucket <= state->udp_table->mask) 2108 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2109 } 2110 2111 int udp_seq_open(struct inode *inode, struct file *file) 2112 { 2113 struct udp_seq_afinfo *afinfo = PDE_DATA(inode); 2114 struct udp_iter_state *s; 2115 int err; 2116 2117 err = seq_open_net(inode, file, &afinfo->seq_ops, 2118 sizeof(struct udp_iter_state)); 2119 if (err < 0) 2120 return err; 2121 2122 s = ((struct seq_file *)file->private_data)->private; 2123 s->family = afinfo->family; 2124 s->udp_table = afinfo->udp_table; 2125 return err; 2126 } 2127 EXPORT_SYMBOL(udp_seq_open); 2128 2129 /* ------------------------------------------------------------------------ */ 2130 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) 2131 { 2132 struct proc_dir_entry *p; 2133 int rc = 0; 2134 2135 afinfo->seq_ops.start = udp_seq_start; 2136 afinfo->seq_ops.next = udp_seq_next; 2137 afinfo->seq_ops.stop = udp_seq_stop; 2138 2139 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 2140 afinfo->seq_fops, afinfo); 2141 if (!p) 2142 rc = -ENOMEM; 2143 return rc; 2144 } 2145 EXPORT_SYMBOL(udp_proc_register); 2146 2147 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 2148 { 2149 remove_proc_entry(afinfo->name, net->proc_net); 2150 } 2151 EXPORT_SYMBOL(udp_proc_unregister); 2152 2153 /* ------------------------------------------------------------------------ */ 2154 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2155 int bucket, int *len) 2156 { 2157 struct inet_sock *inet = inet_sk(sp); 2158 __be32 dest = inet->inet_daddr; 2159 __be32 src = inet->inet_rcv_saddr; 2160 __u16 destp = ntohs(inet->inet_dport); 2161 __u16 srcp = ntohs(inet->inet_sport); 2162 2163 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2164 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d%n", 2165 bucket, src, srcp, dest, destp, sp->sk_state, 2166 sk_wmem_alloc_get(sp), 2167 sk_rmem_alloc_get(sp), 2168 0, 0L, 0, 2169 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2170 0, sock_i_ino(sp), 2171 atomic_read(&sp->sk_refcnt), sp, 2172 atomic_read(&sp->sk_drops), len); 2173 } 2174 2175 int udp4_seq_show(struct seq_file *seq, void *v) 2176 { 2177 if (v == SEQ_START_TOKEN) 2178 seq_printf(seq, "%-127s\n", 2179 " sl local_address rem_address st tx_queue " 2180 "rx_queue tr tm->when retrnsmt uid timeout " 2181 "inode ref pointer drops"); 2182 else { 2183 struct udp_iter_state *state = seq->private; 2184 int len; 2185 2186 udp4_format_sock(v, seq, state->bucket, &len); 2187 seq_printf(seq, "%*s\n", 127 - len, ""); 2188 } 2189 return 0; 2190 } 2191 2192 static const struct file_operations udp_afinfo_seq_fops = { 2193 .owner = THIS_MODULE, 2194 .open = udp_seq_open, 2195 .read = seq_read, 2196 .llseek = seq_lseek, 2197 .release = seq_release_net 2198 }; 2199 2200 /* ------------------------------------------------------------------------ */ 2201 static struct udp_seq_afinfo udp4_seq_afinfo = { 2202 .name = "udp", 2203 .family = AF_INET, 2204 .udp_table = &udp_table, 2205 .seq_fops = &udp_afinfo_seq_fops, 2206 .seq_ops = { 2207 .show = udp4_seq_show, 2208 }, 2209 }; 2210 2211 static int __net_init udp4_proc_init_net(struct net *net) 2212 { 2213 return udp_proc_register(net, &udp4_seq_afinfo); 2214 } 2215 2216 static void __net_exit udp4_proc_exit_net(struct net *net) 2217 { 2218 udp_proc_unregister(net, &udp4_seq_afinfo); 2219 } 2220 2221 static struct pernet_operations udp4_net_ops = { 2222 .init = udp4_proc_init_net, 2223 .exit = udp4_proc_exit_net, 2224 }; 2225 2226 int __init udp4_proc_init(void) 2227 { 2228 return register_pernet_subsys(&udp4_net_ops); 2229 } 2230 2231 void udp4_proc_exit(void) 2232 { 2233 unregister_pernet_subsys(&udp4_net_ops); 2234 } 2235 #endif /* CONFIG_PROC_FS */ 2236 2237 static __initdata unsigned long uhash_entries; 2238 static int __init set_uhash_entries(char *str) 2239 { 2240 ssize_t ret; 2241 2242 if (!str) 2243 return 0; 2244 2245 ret = kstrtoul(str, 0, &uhash_entries); 2246 if (ret) 2247 return 0; 2248 2249 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2250 uhash_entries = UDP_HTABLE_SIZE_MIN; 2251 return 1; 2252 } 2253 __setup("uhash_entries=", set_uhash_entries); 2254 2255 void __init udp_table_init(struct udp_table *table, const char *name) 2256 { 2257 unsigned int i; 2258 2259 table->hash = alloc_large_system_hash(name, 2260 2 * sizeof(struct udp_hslot), 2261 uhash_entries, 2262 21, /* one slot per 2 MB */ 2263 0, 2264 &table->log, 2265 &table->mask, 2266 UDP_HTABLE_SIZE_MIN, 2267 64 * 1024); 2268 2269 table->hash2 = table->hash + (table->mask + 1); 2270 for (i = 0; i <= table->mask; i++) { 2271 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); 2272 table->hash[i].count = 0; 2273 spin_lock_init(&table->hash[i].lock); 2274 } 2275 for (i = 0; i <= table->mask; i++) { 2276 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); 2277 table->hash2[i].count = 0; 2278 spin_lock_init(&table->hash2[i].lock); 2279 } 2280 } 2281 2282 void __init udp_init(void) 2283 { 2284 unsigned long limit; 2285 2286 udp_table_init(&udp_table, "UDP"); 2287 limit = nr_free_buffer_pages() / 8; 2288 limit = max(limit, 128UL); 2289 sysctl_udp_mem[0] = limit / 4 * 3; 2290 sysctl_udp_mem[1] = limit; 2291 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 2292 2293 sysctl_udp_rmem_min = SK_MEM_QUANTUM; 2294 sysctl_udp_wmem_min = SK_MEM_QUANTUM; 2295 } 2296 2297 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 2298 netdev_features_t features) 2299 { 2300 struct sk_buff *segs = ERR_PTR(-EINVAL); 2301 int mac_len = skb->mac_len; 2302 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); 2303 __be16 protocol = skb->protocol; 2304 netdev_features_t enc_features; 2305 int outer_hlen; 2306 2307 if (unlikely(!pskb_may_pull(skb, tnl_hlen))) 2308 goto out; 2309 2310 skb->encapsulation = 0; 2311 __skb_pull(skb, tnl_hlen); 2312 skb_reset_mac_header(skb); 2313 skb_set_network_header(skb, skb_inner_network_offset(skb)); 2314 skb->mac_len = skb_inner_network_offset(skb); 2315 skb->protocol = htons(ETH_P_TEB); 2316 2317 /* segment inner packet. */ 2318 enc_features = skb->dev->hw_enc_features & netif_skb_features(skb); 2319 segs = skb_mac_gso_segment(skb, enc_features); 2320 if (!segs || IS_ERR(segs)) 2321 goto out; 2322 2323 outer_hlen = skb_tnl_header_len(skb); 2324 skb = segs; 2325 do { 2326 struct udphdr *uh; 2327 int udp_offset = outer_hlen - tnl_hlen; 2328 2329 skb_reset_inner_headers(skb); 2330 skb->encapsulation = 1; 2331 2332 skb->mac_len = mac_len; 2333 2334 skb_push(skb, outer_hlen); 2335 skb_reset_mac_header(skb); 2336 skb_set_network_header(skb, mac_len); 2337 skb_set_transport_header(skb, udp_offset); 2338 uh = udp_hdr(skb); 2339 uh->len = htons(skb->len - udp_offset); 2340 2341 /* csum segment if tunnel sets skb with csum. */ 2342 if (protocol == htons(ETH_P_IP) && unlikely(uh->check)) { 2343 struct iphdr *iph = ip_hdr(skb); 2344 2345 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, 2346 skb->len - udp_offset, 2347 IPPROTO_UDP, 0); 2348 uh->check = csum_fold(skb_checksum(skb, udp_offset, 2349 skb->len - udp_offset, 0)); 2350 if (uh->check == 0) 2351 uh->check = CSUM_MANGLED_0; 2352 2353 } else if (protocol == htons(ETH_P_IPV6)) { 2354 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 2355 u32 len = skb->len - udp_offset; 2356 2357 uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, 2358 len, IPPROTO_UDP, 0); 2359 uh->check = csum_fold(skb_checksum(skb, udp_offset, len, 0)); 2360 if (uh->check == 0) 2361 uh->check = CSUM_MANGLED_0; 2362 skb->ip_summed = CHECKSUM_NONE; 2363 } 2364 2365 skb->protocol = protocol; 2366 } while ((skb = skb->next)); 2367 out: 2368 return segs; 2369 } 2370