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 <linux/uaccess.h> 83 #include <asm/ioctls.h> 84 #include <linux/bootmem.h> 85 #include <linux/highmem.h> 86 #include <linux/swap.h> 87 #include <linux/types.h> 88 #include <linux/fcntl.h> 89 #include <linux/module.h> 90 #include <linux/socket.h> 91 #include <linux/sockios.h> 92 #include <linux/igmp.h> 93 #include <linux/inetdevice.h> 94 #include <linux/in.h> 95 #include <linux/errno.h> 96 #include <linux/timer.h> 97 #include <linux/mm.h> 98 #include <linux/inet.h> 99 #include <linux/netdevice.h> 100 #include <linux/slab.h> 101 #include <net/tcp_states.h> 102 #include <linux/skbuff.h> 103 #include <linux/proc_fs.h> 104 #include <linux/seq_file.h> 105 #include <net/net_namespace.h> 106 #include <net/icmp.h> 107 #include <net/inet_hashtables.h> 108 #include <net/route.h> 109 #include <net/checksum.h> 110 #include <net/xfrm.h> 111 #include <trace/events/udp.h> 112 #include <linux/static_key.h> 113 #include <trace/events/skb.h> 114 #include <net/busy_poll.h> 115 #include "udp_impl.h" 116 #include <net/sock_reuseport.h> 117 #include <net/addrconf.h> 118 119 struct udp_table udp_table __read_mostly; 120 EXPORT_SYMBOL(udp_table); 121 122 long sysctl_udp_mem[3] __read_mostly; 123 EXPORT_SYMBOL(sysctl_udp_mem); 124 125 int sysctl_udp_rmem_min __read_mostly; 126 EXPORT_SYMBOL(sysctl_udp_rmem_min); 127 128 int sysctl_udp_wmem_min __read_mostly; 129 EXPORT_SYMBOL(sysctl_udp_wmem_min); 130 131 atomic_long_t udp_memory_allocated; 132 EXPORT_SYMBOL(udp_memory_allocated); 133 134 #define MAX_UDP_PORTS 65536 135 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 136 137 /* IPCB reference means this can not be used from early demux */ 138 static bool udp_lib_exact_dif_match(struct net *net, struct sk_buff *skb) 139 { 140 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 141 if (!net->ipv4.sysctl_udp_l3mdev_accept && 142 skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) 143 return true; 144 #endif 145 return false; 146 } 147 148 static int udp_lib_lport_inuse(struct net *net, __u16 num, 149 const struct udp_hslot *hslot, 150 unsigned long *bitmap, 151 struct sock *sk, unsigned int log) 152 { 153 struct sock *sk2; 154 kuid_t uid = sock_i_uid(sk); 155 156 sk_for_each(sk2, &hslot->head) { 157 if (net_eq(sock_net(sk2), net) && 158 sk2 != sk && 159 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 160 (!sk2->sk_reuse || !sk->sk_reuse) && 161 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 162 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 163 inet_rcv_saddr_equal(sk, sk2, true)) { 164 if (sk2->sk_reuseport && sk->sk_reuseport && 165 !rcu_access_pointer(sk->sk_reuseport_cb) && 166 uid_eq(uid, sock_i_uid(sk2))) { 167 if (!bitmap) 168 return 0; 169 } else { 170 if (!bitmap) 171 return 1; 172 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 173 bitmap); 174 } 175 } 176 } 177 return 0; 178 } 179 180 /* 181 * Note: we still hold spinlock of primary hash chain, so no other writer 182 * can insert/delete a socket with local_port == num 183 */ 184 static int udp_lib_lport_inuse2(struct net *net, __u16 num, 185 struct udp_hslot *hslot2, 186 struct sock *sk) 187 { 188 struct sock *sk2; 189 kuid_t uid = sock_i_uid(sk); 190 int res = 0; 191 192 spin_lock(&hslot2->lock); 193 udp_portaddr_for_each_entry(sk2, &hslot2->head) { 194 if (net_eq(sock_net(sk2), net) && 195 sk2 != sk && 196 (udp_sk(sk2)->udp_port_hash == num) && 197 (!sk2->sk_reuse || !sk->sk_reuse) && 198 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 199 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 200 inet_rcv_saddr_equal(sk, sk2, true)) { 201 if (sk2->sk_reuseport && sk->sk_reuseport && 202 !rcu_access_pointer(sk->sk_reuseport_cb) && 203 uid_eq(uid, sock_i_uid(sk2))) { 204 res = 0; 205 } else { 206 res = 1; 207 } 208 break; 209 } 210 } 211 spin_unlock(&hslot2->lock); 212 return res; 213 } 214 215 static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot) 216 { 217 struct net *net = sock_net(sk); 218 kuid_t uid = sock_i_uid(sk); 219 struct sock *sk2; 220 221 sk_for_each(sk2, &hslot->head) { 222 if (net_eq(sock_net(sk2), net) && 223 sk2 != sk && 224 sk2->sk_family == sk->sk_family && 225 ipv6_only_sock(sk2) == ipv6_only_sock(sk) && 226 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) && 227 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 228 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && 229 inet_rcv_saddr_equal(sk, sk2, false)) { 230 return reuseport_add_sock(sk, sk2); 231 } 232 } 233 234 /* Initial allocation may have already happened via setsockopt */ 235 if (!rcu_access_pointer(sk->sk_reuseport_cb)) 236 return reuseport_alloc(sk); 237 return 0; 238 } 239 240 /** 241 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 242 * 243 * @sk: socket struct in question 244 * @snum: port number to look up 245 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 246 * with NULL address 247 */ 248 int udp_lib_get_port(struct sock *sk, unsigned short snum, 249 unsigned int hash2_nulladdr) 250 { 251 struct udp_hslot *hslot, *hslot2; 252 struct udp_table *udptable = sk->sk_prot->h.udp_table; 253 int error = 1; 254 struct net *net = sock_net(sk); 255 256 if (!snum) { 257 int low, high, remaining; 258 unsigned int rand; 259 unsigned short first, last; 260 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 261 262 inet_get_local_port_range(net, &low, &high); 263 remaining = (high - low) + 1; 264 265 rand = prandom_u32(); 266 first = reciprocal_scale(rand, remaining) + low; 267 /* 268 * force rand to be an odd multiple of UDP_HTABLE_SIZE 269 */ 270 rand = (rand | 1) * (udptable->mask + 1); 271 last = first + udptable->mask + 1; 272 do { 273 hslot = udp_hashslot(udptable, net, first); 274 bitmap_zero(bitmap, PORTS_PER_CHAIN); 275 spin_lock_bh(&hslot->lock); 276 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 277 udptable->log); 278 279 snum = first; 280 /* 281 * Iterate on all possible values of snum for this hash. 282 * Using steps of an odd multiple of UDP_HTABLE_SIZE 283 * give us randomization and full range coverage. 284 */ 285 do { 286 if (low <= snum && snum <= high && 287 !test_bit(snum >> udptable->log, bitmap) && 288 !inet_is_local_reserved_port(net, snum)) 289 goto found; 290 snum += rand; 291 } while (snum != first); 292 spin_unlock_bh(&hslot->lock); 293 cond_resched(); 294 } while (++first != last); 295 goto fail; 296 } else { 297 hslot = udp_hashslot(udptable, net, snum); 298 spin_lock_bh(&hslot->lock); 299 if (hslot->count > 10) { 300 int exist; 301 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 302 303 slot2 &= udptable->mask; 304 hash2_nulladdr &= udptable->mask; 305 306 hslot2 = udp_hashslot2(udptable, slot2); 307 if (hslot->count < hslot2->count) 308 goto scan_primary_hash; 309 310 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk); 311 if (!exist && (hash2_nulladdr != slot2)) { 312 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 313 exist = udp_lib_lport_inuse2(net, snum, hslot2, 314 sk); 315 } 316 if (exist) 317 goto fail_unlock; 318 else 319 goto found; 320 } 321 scan_primary_hash: 322 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0)) 323 goto fail_unlock; 324 } 325 found: 326 inet_sk(sk)->inet_num = snum; 327 udp_sk(sk)->udp_port_hash = snum; 328 udp_sk(sk)->udp_portaddr_hash ^= snum; 329 if (sk_unhashed(sk)) { 330 if (sk->sk_reuseport && 331 udp_reuseport_add_sock(sk, hslot)) { 332 inet_sk(sk)->inet_num = 0; 333 udp_sk(sk)->udp_port_hash = 0; 334 udp_sk(sk)->udp_portaddr_hash ^= snum; 335 goto fail_unlock; 336 } 337 338 sk_add_node_rcu(sk, &hslot->head); 339 hslot->count++; 340 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 341 342 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 343 spin_lock(&hslot2->lock); 344 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 345 sk->sk_family == AF_INET6) 346 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node, 347 &hslot2->head); 348 else 349 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 350 &hslot2->head); 351 hslot2->count++; 352 spin_unlock(&hslot2->lock); 353 } 354 sock_set_flag(sk, SOCK_RCU_FREE); 355 error = 0; 356 fail_unlock: 357 spin_unlock_bh(&hslot->lock); 358 fail: 359 return error; 360 } 361 EXPORT_SYMBOL(udp_lib_get_port); 362 363 static u32 udp4_portaddr_hash(const struct net *net, __be32 saddr, 364 unsigned int port) 365 { 366 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 367 } 368 369 int udp_v4_get_port(struct sock *sk, unsigned short snum) 370 { 371 unsigned int hash2_nulladdr = 372 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 373 unsigned int hash2_partial = 374 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 375 376 /* precompute partial secondary hash */ 377 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 378 return udp_lib_get_port(sk, snum, hash2_nulladdr); 379 } 380 381 static int compute_score(struct sock *sk, struct net *net, 382 __be32 saddr, __be16 sport, 383 __be32 daddr, unsigned short hnum, int dif, 384 bool exact_dif) 385 { 386 int score; 387 struct inet_sock *inet; 388 389 if (!net_eq(sock_net(sk), net) || 390 udp_sk(sk)->udp_port_hash != hnum || 391 ipv6_only_sock(sk)) 392 return -1; 393 394 score = (sk->sk_family == PF_INET) ? 2 : 1; 395 inet = inet_sk(sk); 396 397 if (inet->inet_rcv_saddr) { 398 if (inet->inet_rcv_saddr != daddr) 399 return -1; 400 score += 4; 401 } 402 403 if (inet->inet_daddr) { 404 if (inet->inet_daddr != saddr) 405 return -1; 406 score += 4; 407 } 408 409 if (inet->inet_dport) { 410 if (inet->inet_dport != sport) 411 return -1; 412 score += 4; 413 } 414 415 if (sk->sk_bound_dev_if || exact_dif) { 416 if (sk->sk_bound_dev_if != dif) 417 return -1; 418 score += 4; 419 } 420 if (sk->sk_incoming_cpu == raw_smp_processor_id()) 421 score++; 422 return score; 423 } 424 425 static u32 udp_ehashfn(const struct net *net, const __be32 laddr, 426 const __u16 lport, const __be32 faddr, 427 const __be16 fport) 428 { 429 static u32 udp_ehash_secret __read_mostly; 430 431 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); 432 433 return __inet_ehashfn(laddr, lport, faddr, fport, 434 udp_ehash_secret + net_hash_mix(net)); 435 } 436 437 /* called with rcu_read_lock() */ 438 static struct sock *udp4_lib_lookup2(struct net *net, 439 __be32 saddr, __be16 sport, 440 __be32 daddr, unsigned int hnum, int dif, bool exact_dif, 441 struct udp_hslot *hslot2, 442 struct sk_buff *skb) 443 { 444 struct sock *sk, *result; 445 int score, badness, matches = 0, reuseport = 0; 446 u32 hash = 0; 447 448 result = NULL; 449 badness = 0; 450 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 451 score = compute_score(sk, net, saddr, sport, 452 daddr, hnum, dif, exact_dif); 453 if (score > badness) { 454 reuseport = sk->sk_reuseport; 455 if (reuseport) { 456 hash = udp_ehashfn(net, daddr, hnum, 457 saddr, sport); 458 result = reuseport_select_sock(sk, hash, skb, 459 sizeof(struct udphdr)); 460 if (result) 461 return result; 462 matches = 1; 463 } 464 badness = score; 465 result = sk; 466 } else if (score == badness && reuseport) { 467 matches++; 468 if (reciprocal_scale(hash, matches) == 0) 469 result = sk; 470 hash = next_pseudo_random32(hash); 471 } 472 } 473 return result; 474 } 475 476 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 477 * harder than this. -DaveM 478 */ 479 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 480 __be16 sport, __be32 daddr, __be16 dport, 481 int dif, struct udp_table *udptable, struct sk_buff *skb) 482 { 483 struct sock *sk, *result; 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 bool exact_dif = udp_lib_exact_dif_match(net, skb); 488 int score, badness, matches = 0, reuseport = 0; 489 u32 hash = 0; 490 491 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 exact_dif, hslot2, skb); 501 if (!result) { 502 unsigned int old_slot2 = slot2; 503 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 504 slot2 = hash2 & udptable->mask; 505 /* avoid searching the same slot again. */ 506 if (unlikely(slot2 == old_slot2)) 507 return result; 508 509 hslot2 = &udptable->hash2[slot2]; 510 if (hslot->count < hslot2->count) 511 goto begin; 512 513 result = udp4_lib_lookup2(net, saddr, sport, 514 daddr, hnum, dif, 515 exact_dif, hslot2, skb); 516 } 517 return result; 518 } 519 begin: 520 result = NULL; 521 badness = 0; 522 sk_for_each_rcu(sk, &hslot->head) { 523 score = compute_score(sk, net, saddr, sport, 524 daddr, hnum, dif, exact_dif); 525 if (score > badness) { 526 reuseport = sk->sk_reuseport; 527 if (reuseport) { 528 hash = udp_ehashfn(net, daddr, hnum, 529 saddr, sport); 530 result = reuseport_select_sock(sk, hash, skb, 531 sizeof(struct udphdr)); 532 if (result) 533 return result; 534 matches = 1; 535 } 536 result = sk; 537 badness = score; 538 } else if (score == badness && reuseport) { 539 matches++; 540 if (reciprocal_scale(hash, matches) == 0) 541 result = sk; 542 hash = next_pseudo_random32(hash); 543 } 544 } 545 return result; 546 } 547 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 548 549 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 550 __be16 sport, __be16 dport, 551 struct udp_table *udptable) 552 { 553 const struct iphdr *iph = ip_hdr(skb); 554 555 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 556 iph->daddr, dport, inet_iif(skb), 557 udptable, skb); 558 } 559 560 struct sock *udp4_lib_lookup_skb(struct sk_buff *skb, 561 __be16 sport, __be16 dport) 562 { 563 return __udp4_lib_lookup_skb(skb, sport, dport, &udp_table); 564 } 565 EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb); 566 567 /* Must be called under rcu_read_lock(). 568 * Does increment socket refcount. 569 */ 570 #if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \ 571 IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \ 572 IS_ENABLED(CONFIG_NF_SOCKET_IPV4) 573 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 574 __be32 daddr, __be16 dport, int dif) 575 { 576 struct sock *sk; 577 578 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport, 579 dif, &udp_table, NULL); 580 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) 581 sk = NULL; 582 return sk; 583 } 584 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 585 #endif 586 587 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, 588 __be16 loc_port, __be32 loc_addr, 589 __be16 rmt_port, __be32 rmt_addr, 590 int dif, unsigned short hnum) 591 { 592 struct inet_sock *inet = inet_sk(sk); 593 594 if (!net_eq(sock_net(sk), net) || 595 udp_sk(sk)->udp_port_hash != hnum || 596 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 597 (inet->inet_dport != rmt_port && inet->inet_dport) || 598 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) || 599 ipv6_only_sock(sk) || 600 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) 601 return false; 602 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif)) 603 return false; 604 return true; 605 } 606 607 /* 608 * This routine is called by the ICMP module when it gets some 609 * sort of error condition. If err < 0 then the socket should 610 * be closed and the error returned to the user. If err > 0 611 * it's just the icmp type << 8 | icmp code. 612 * Header points to the ip header of the error packet. We move 613 * on past this. Then (as it used to claim before adjustment) 614 * header points to the first 8 bytes of the udp header. We need 615 * to find the appropriate port. 616 */ 617 618 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 619 { 620 struct inet_sock *inet; 621 const struct iphdr *iph = (const struct iphdr *)skb->data; 622 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 623 const int type = icmp_hdr(skb)->type; 624 const int code = icmp_hdr(skb)->code; 625 struct sock *sk; 626 int harderr; 627 int err; 628 struct net *net = dev_net(skb->dev); 629 630 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 631 iph->saddr, uh->source, skb->dev->ifindex, udptable, 632 NULL); 633 if (!sk) { 634 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); 635 return; /* No socket for error */ 636 } 637 638 err = 0; 639 harderr = 0; 640 inet = inet_sk(sk); 641 642 switch (type) { 643 default: 644 case ICMP_TIME_EXCEEDED: 645 err = EHOSTUNREACH; 646 break; 647 case ICMP_SOURCE_QUENCH: 648 goto out; 649 case ICMP_PARAMETERPROB: 650 err = EPROTO; 651 harderr = 1; 652 break; 653 case ICMP_DEST_UNREACH: 654 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 655 ipv4_sk_update_pmtu(skb, sk, info); 656 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 657 err = EMSGSIZE; 658 harderr = 1; 659 break; 660 } 661 goto out; 662 } 663 err = EHOSTUNREACH; 664 if (code <= NR_ICMP_UNREACH) { 665 harderr = icmp_err_convert[code].fatal; 666 err = icmp_err_convert[code].errno; 667 } 668 break; 669 case ICMP_REDIRECT: 670 ipv4_sk_redirect(skb, sk); 671 goto out; 672 } 673 674 /* 675 * RFC1122: OK. Passes ICMP errors back to application, as per 676 * 4.1.3.3. 677 */ 678 if (!inet->recverr) { 679 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 680 goto out; 681 } else 682 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 683 684 sk->sk_err = err; 685 sk->sk_error_report(sk); 686 out: 687 return; 688 } 689 690 void udp_err(struct sk_buff *skb, u32 info) 691 { 692 __udp4_lib_err(skb, info, &udp_table); 693 } 694 695 /* 696 * Throw away all pending data and cancel the corking. Socket is locked. 697 */ 698 void udp_flush_pending_frames(struct sock *sk) 699 { 700 struct udp_sock *up = udp_sk(sk); 701 702 if (up->pending) { 703 up->len = 0; 704 up->pending = 0; 705 ip_flush_pending_frames(sk); 706 } 707 } 708 EXPORT_SYMBOL(udp_flush_pending_frames); 709 710 /** 711 * udp4_hwcsum - handle outgoing HW checksumming 712 * @skb: sk_buff containing the filled-in UDP header 713 * (checksum field must be zeroed out) 714 * @src: source IP address 715 * @dst: destination IP address 716 */ 717 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 718 { 719 struct udphdr *uh = udp_hdr(skb); 720 int offset = skb_transport_offset(skb); 721 int len = skb->len - offset; 722 int hlen = len; 723 __wsum csum = 0; 724 725 if (!skb_has_frag_list(skb)) { 726 /* 727 * Only one fragment on the socket. 728 */ 729 skb->csum_start = skb_transport_header(skb) - skb->head; 730 skb->csum_offset = offsetof(struct udphdr, check); 731 uh->check = ~csum_tcpudp_magic(src, dst, len, 732 IPPROTO_UDP, 0); 733 } else { 734 struct sk_buff *frags; 735 736 /* 737 * HW-checksum won't work as there are two or more 738 * fragments on the socket so that all csums of sk_buffs 739 * should be together 740 */ 741 skb_walk_frags(skb, frags) { 742 csum = csum_add(csum, frags->csum); 743 hlen -= frags->len; 744 } 745 746 csum = skb_checksum(skb, offset, hlen, csum); 747 skb->ip_summed = CHECKSUM_NONE; 748 749 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 750 if (uh->check == 0) 751 uh->check = CSUM_MANGLED_0; 752 } 753 } 754 EXPORT_SYMBOL_GPL(udp4_hwcsum); 755 756 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended 757 * for the simple case like when setting the checksum for a UDP tunnel. 758 */ 759 void udp_set_csum(bool nocheck, struct sk_buff *skb, 760 __be32 saddr, __be32 daddr, int len) 761 { 762 struct udphdr *uh = udp_hdr(skb); 763 764 if (nocheck) { 765 uh->check = 0; 766 } else if (skb_is_gso(skb)) { 767 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 768 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { 769 uh->check = 0; 770 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb)); 771 if (uh->check == 0) 772 uh->check = CSUM_MANGLED_0; 773 } else { 774 skb->ip_summed = CHECKSUM_PARTIAL; 775 skb->csum_start = skb_transport_header(skb) - skb->head; 776 skb->csum_offset = offsetof(struct udphdr, check); 777 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 778 } 779 } 780 EXPORT_SYMBOL(udp_set_csum); 781 782 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) 783 { 784 struct sock *sk = skb->sk; 785 struct inet_sock *inet = inet_sk(sk); 786 struct udphdr *uh; 787 int err = 0; 788 int is_udplite = IS_UDPLITE(sk); 789 int offset = skb_transport_offset(skb); 790 int len = skb->len - offset; 791 __wsum csum = 0; 792 793 /* 794 * Create a UDP header 795 */ 796 uh = udp_hdr(skb); 797 uh->source = inet->inet_sport; 798 uh->dest = fl4->fl4_dport; 799 uh->len = htons(len); 800 uh->check = 0; 801 802 if (is_udplite) /* UDP-Lite */ 803 csum = udplite_csum(skb); 804 805 else if (sk->sk_no_check_tx) { /* UDP csum disabled */ 806 807 skb->ip_summed = CHECKSUM_NONE; 808 goto send; 809 810 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 811 812 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 813 goto send; 814 815 } else 816 csum = udp_csum(skb); 817 818 /* add protocol-dependent pseudo-header */ 819 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 820 sk->sk_protocol, csum); 821 if (uh->check == 0) 822 uh->check = CSUM_MANGLED_0; 823 824 send: 825 err = ip_send_skb(sock_net(sk), skb); 826 if (err) { 827 if (err == -ENOBUFS && !inet->recverr) { 828 UDP_INC_STATS(sock_net(sk), 829 UDP_MIB_SNDBUFERRORS, is_udplite); 830 err = 0; 831 } 832 } else 833 UDP_INC_STATS(sock_net(sk), 834 UDP_MIB_OUTDATAGRAMS, is_udplite); 835 return err; 836 } 837 838 /* 839 * Push out all pending data as one UDP datagram. Socket is locked. 840 */ 841 int udp_push_pending_frames(struct sock *sk) 842 { 843 struct udp_sock *up = udp_sk(sk); 844 struct inet_sock *inet = inet_sk(sk); 845 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 846 struct sk_buff *skb; 847 int err = 0; 848 849 skb = ip_finish_skb(sk, fl4); 850 if (!skb) 851 goto out; 852 853 err = udp_send_skb(skb, fl4); 854 855 out: 856 up->len = 0; 857 up->pending = 0; 858 return err; 859 } 860 EXPORT_SYMBOL(udp_push_pending_frames); 861 862 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 863 { 864 struct inet_sock *inet = inet_sk(sk); 865 struct udp_sock *up = udp_sk(sk); 866 struct flowi4 fl4_stack; 867 struct flowi4 *fl4; 868 int ulen = len; 869 struct ipcm_cookie ipc; 870 struct rtable *rt = NULL; 871 int free = 0; 872 int connected = 0; 873 __be32 daddr, faddr, saddr; 874 __be16 dport; 875 u8 tos; 876 int err, is_udplite = IS_UDPLITE(sk); 877 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 878 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 879 struct sk_buff *skb; 880 struct ip_options_data opt_copy; 881 882 if (len > 0xFFFF) 883 return -EMSGSIZE; 884 885 /* 886 * Check the flags. 887 */ 888 889 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 890 return -EOPNOTSUPP; 891 892 ipc.opt = NULL; 893 ipc.tx_flags = 0; 894 ipc.ttl = 0; 895 ipc.tos = -1; 896 897 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 898 899 fl4 = &inet->cork.fl.u.ip4; 900 if (up->pending) { 901 /* 902 * There are pending frames. 903 * The socket lock must be held while it's corked. 904 */ 905 lock_sock(sk); 906 if (likely(up->pending)) { 907 if (unlikely(up->pending != AF_INET)) { 908 release_sock(sk); 909 return -EINVAL; 910 } 911 goto do_append_data; 912 } 913 release_sock(sk); 914 } 915 ulen += sizeof(struct udphdr); 916 917 /* 918 * Get and verify the address. 919 */ 920 if (msg->msg_name) { 921 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 922 if (msg->msg_namelen < sizeof(*usin)) 923 return -EINVAL; 924 if (usin->sin_family != AF_INET) { 925 if (usin->sin_family != AF_UNSPEC) 926 return -EAFNOSUPPORT; 927 } 928 929 daddr = usin->sin_addr.s_addr; 930 dport = usin->sin_port; 931 if (dport == 0) 932 return -EINVAL; 933 } else { 934 if (sk->sk_state != TCP_ESTABLISHED) 935 return -EDESTADDRREQ; 936 daddr = inet->inet_daddr; 937 dport = inet->inet_dport; 938 /* Open fast path for connected socket. 939 Route will not be used, if at least one option is set. 940 */ 941 connected = 1; 942 } 943 944 ipc.sockc.tsflags = sk->sk_tsflags; 945 ipc.addr = inet->inet_saddr; 946 ipc.oif = sk->sk_bound_dev_if; 947 948 if (msg->msg_controllen) { 949 err = ip_cmsg_send(sk, msg, &ipc, sk->sk_family == AF_INET6); 950 if (unlikely(err)) { 951 kfree(ipc.opt); 952 return err; 953 } 954 if (ipc.opt) 955 free = 1; 956 connected = 0; 957 } 958 if (!ipc.opt) { 959 struct ip_options_rcu *inet_opt; 960 961 rcu_read_lock(); 962 inet_opt = rcu_dereference(inet->inet_opt); 963 if (inet_opt) { 964 memcpy(&opt_copy, inet_opt, 965 sizeof(*inet_opt) + inet_opt->opt.optlen); 966 ipc.opt = &opt_copy.opt; 967 } 968 rcu_read_unlock(); 969 } 970 971 saddr = ipc.addr; 972 ipc.addr = faddr = daddr; 973 974 sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags); 975 976 if (ipc.opt && ipc.opt->opt.srr) { 977 if (!daddr) 978 return -EINVAL; 979 faddr = ipc.opt->opt.faddr; 980 connected = 0; 981 } 982 tos = get_rttos(&ipc, inet); 983 if (sock_flag(sk, SOCK_LOCALROUTE) || 984 (msg->msg_flags & MSG_DONTROUTE) || 985 (ipc.opt && ipc.opt->opt.is_strictroute)) { 986 tos |= RTO_ONLINK; 987 connected = 0; 988 } 989 990 if (ipv4_is_multicast(daddr)) { 991 if (!ipc.oif) 992 ipc.oif = inet->mc_index; 993 if (!saddr) 994 saddr = inet->mc_addr; 995 connected = 0; 996 } else if (!ipc.oif) 997 ipc.oif = inet->uc_index; 998 999 if (connected) 1000 rt = (struct rtable *)sk_dst_check(sk, 0); 1001 1002 if (!rt) { 1003 struct net *net = sock_net(sk); 1004 __u8 flow_flags = inet_sk_flowi_flags(sk); 1005 1006 fl4 = &fl4_stack; 1007 1008 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, 1009 RT_SCOPE_UNIVERSE, sk->sk_protocol, 1010 flow_flags, 1011 faddr, saddr, dport, inet->inet_sport, 1012 sk->sk_uid); 1013 1014 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 1015 rt = ip_route_output_flow(net, fl4, sk); 1016 if (IS_ERR(rt)) { 1017 err = PTR_ERR(rt); 1018 rt = NULL; 1019 if (err == -ENETUNREACH) 1020 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 1021 goto out; 1022 } 1023 1024 err = -EACCES; 1025 if ((rt->rt_flags & RTCF_BROADCAST) && 1026 !sock_flag(sk, SOCK_BROADCAST)) 1027 goto out; 1028 if (connected) 1029 sk_dst_set(sk, dst_clone(&rt->dst)); 1030 } 1031 1032 if (msg->msg_flags&MSG_CONFIRM) 1033 goto do_confirm; 1034 back_from_confirm: 1035 1036 saddr = fl4->saddr; 1037 if (!ipc.addr) 1038 daddr = ipc.addr = fl4->daddr; 1039 1040 /* Lockless fast path for the non-corking case. */ 1041 if (!corkreq) { 1042 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen, 1043 sizeof(struct udphdr), &ipc, &rt, 1044 msg->msg_flags); 1045 err = PTR_ERR(skb); 1046 if (!IS_ERR_OR_NULL(skb)) 1047 err = udp_send_skb(skb, fl4); 1048 goto out; 1049 } 1050 1051 lock_sock(sk); 1052 if (unlikely(up->pending)) { 1053 /* The socket is already corked while preparing it. */ 1054 /* ... which is an evident application bug. --ANK */ 1055 release_sock(sk); 1056 1057 net_dbg_ratelimited("cork app bug 2\n"); 1058 err = -EINVAL; 1059 goto out; 1060 } 1061 /* 1062 * Now cork the socket to pend data. 1063 */ 1064 fl4 = &inet->cork.fl.u.ip4; 1065 fl4->daddr = daddr; 1066 fl4->saddr = saddr; 1067 fl4->fl4_dport = dport; 1068 fl4->fl4_sport = inet->inet_sport; 1069 up->pending = AF_INET; 1070 1071 do_append_data: 1072 up->len += ulen; 1073 err = ip_append_data(sk, fl4, getfrag, msg, ulen, 1074 sizeof(struct udphdr), &ipc, &rt, 1075 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1076 if (err) 1077 udp_flush_pending_frames(sk); 1078 else if (!corkreq) 1079 err = udp_push_pending_frames(sk); 1080 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1081 up->pending = 0; 1082 release_sock(sk); 1083 1084 out: 1085 ip_rt_put(rt); 1086 if (free) 1087 kfree(ipc.opt); 1088 if (!err) 1089 return len; 1090 /* 1091 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1092 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1093 * we don't have a good statistic (IpOutDiscards but it can be too many 1094 * things). We could add another new stat but at least for now that 1095 * seems like overkill. 1096 */ 1097 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1098 UDP_INC_STATS(sock_net(sk), 1099 UDP_MIB_SNDBUFERRORS, is_udplite); 1100 } 1101 return err; 1102 1103 do_confirm: 1104 if (msg->msg_flags & MSG_PROBE) 1105 dst_confirm_neigh(&rt->dst, &fl4->daddr); 1106 if (!(msg->msg_flags&MSG_PROBE) || len) 1107 goto back_from_confirm; 1108 err = 0; 1109 goto out; 1110 } 1111 EXPORT_SYMBOL(udp_sendmsg); 1112 1113 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1114 size_t size, int flags) 1115 { 1116 struct inet_sock *inet = inet_sk(sk); 1117 struct udp_sock *up = udp_sk(sk); 1118 int ret; 1119 1120 if (flags & MSG_SENDPAGE_NOTLAST) 1121 flags |= MSG_MORE; 1122 1123 if (!up->pending) { 1124 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1125 1126 /* Call udp_sendmsg to specify destination address which 1127 * sendpage interface can't pass. 1128 * This will succeed only when the socket is connected. 1129 */ 1130 ret = udp_sendmsg(sk, &msg, 0); 1131 if (ret < 0) 1132 return ret; 1133 } 1134 1135 lock_sock(sk); 1136 1137 if (unlikely(!up->pending)) { 1138 release_sock(sk); 1139 1140 net_dbg_ratelimited("udp cork app bug 3\n"); 1141 return -EINVAL; 1142 } 1143 1144 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1145 page, offset, size, flags); 1146 if (ret == -EOPNOTSUPP) { 1147 release_sock(sk); 1148 return sock_no_sendpage(sk->sk_socket, page, offset, 1149 size, flags); 1150 } 1151 if (ret < 0) { 1152 udp_flush_pending_frames(sk); 1153 goto out; 1154 } 1155 1156 up->len += size; 1157 if (!(up->corkflag || (flags&MSG_MORE))) 1158 ret = udp_push_pending_frames(sk); 1159 if (!ret) 1160 ret = size; 1161 out: 1162 release_sock(sk); 1163 return ret; 1164 } 1165 1166 #if BITS_PER_LONG == 64 1167 static void udp_set_dev_scratch(struct sk_buff *skb) 1168 { 1169 struct udp_dev_scratch *scratch; 1170 1171 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long)); 1172 scratch = (struct udp_dev_scratch *)&skb->dev_scratch; 1173 scratch->truesize = skb->truesize; 1174 scratch->len = skb->len; 1175 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb); 1176 scratch->is_linear = !skb_is_nonlinear(skb); 1177 } 1178 1179 static int udp_skb_truesize(struct sk_buff *skb) 1180 { 1181 return ((struct udp_dev_scratch *)&skb->dev_scratch)->truesize; 1182 } 1183 #else 1184 static void udp_set_dev_scratch(struct sk_buff *skb) 1185 { 1186 skb->dev_scratch = skb->truesize; 1187 } 1188 1189 static int udp_skb_truesize(struct sk_buff *skb) 1190 { 1191 return skb->dev_scratch; 1192 } 1193 #endif 1194 1195 /* fully reclaim rmem/fwd memory allocated for skb */ 1196 static void udp_rmem_release(struct sock *sk, int size, int partial, 1197 bool rx_queue_lock_held) 1198 { 1199 struct udp_sock *up = udp_sk(sk); 1200 struct sk_buff_head *sk_queue; 1201 int amt; 1202 1203 if (likely(partial)) { 1204 up->forward_deficit += size; 1205 size = up->forward_deficit; 1206 if (size < (sk->sk_rcvbuf >> 2) && 1207 !skb_queue_empty(&up->reader_queue)) 1208 return; 1209 } else { 1210 size += up->forward_deficit; 1211 } 1212 up->forward_deficit = 0; 1213 1214 /* acquire the sk_receive_queue for fwd allocated memory scheduling, 1215 * if the called don't held it already 1216 */ 1217 sk_queue = &sk->sk_receive_queue; 1218 if (!rx_queue_lock_held) 1219 spin_lock(&sk_queue->lock); 1220 1221 1222 sk->sk_forward_alloc += size; 1223 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1); 1224 sk->sk_forward_alloc -= amt; 1225 1226 if (amt) 1227 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT); 1228 1229 atomic_sub(size, &sk->sk_rmem_alloc); 1230 1231 /* this can save us from acquiring the rx queue lock on next receive */ 1232 skb_queue_splice_tail_init(sk_queue, &up->reader_queue); 1233 1234 if (!rx_queue_lock_held) 1235 spin_unlock(&sk_queue->lock); 1236 } 1237 1238 /* Note: called with reader_queue.lock held. 1239 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch 1240 * This avoids a cache line miss while receive_queue lock is held. 1241 * Look at __udp_enqueue_schedule_skb() to find where this copy is done. 1242 */ 1243 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb) 1244 { 1245 prefetch(&skb->data); 1246 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false); 1247 } 1248 EXPORT_SYMBOL(udp_skb_destructor); 1249 1250 /* as above, but the caller held the rx queue lock, too */ 1251 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb) 1252 { 1253 prefetch(&skb->data); 1254 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true); 1255 } 1256 1257 /* Idea of busylocks is to let producers grab an extra spinlock 1258 * to relieve pressure on the receive_queue spinlock shared by consumer. 1259 * Under flood, this means that only one producer can be in line 1260 * trying to acquire the receive_queue spinlock. 1261 * These busylock can be allocated on a per cpu manner, instead of a 1262 * per socket one (that would consume a cache line per socket) 1263 */ 1264 static int udp_busylocks_log __read_mostly; 1265 static spinlock_t *udp_busylocks __read_mostly; 1266 1267 static spinlock_t *busylock_acquire(void *ptr) 1268 { 1269 spinlock_t *busy; 1270 1271 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log); 1272 spin_lock(busy); 1273 return busy; 1274 } 1275 1276 static void busylock_release(spinlock_t *busy) 1277 { 1278 if (busy) 1279 spin_unlock(busy); 1280 } 1281 1282 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) 1283 { 1284 struct sk_buff_head *list = &sk->sk_receive_queue; 1285 int rmem, delta, amt, err = -ENOMEM; 1286 spinlock_t *busy = NULL; 1287 int size; 1288 1289 /* try to avoid the costly atomic add/sub pair when the receive 1290 * queue is full; always allow at least a packet 1291 */ 1292 rmem = atomic_read(&sk->sk_rmem_alloc); 1293 if (rmem > sk->sk_rcvbuf) 1294 goto drop; 1295 1296 /* Under mem pressure, it might be helpful to help udp_recvmsg() 1297 * having linear skbs : 1298 * - Reduce memory overhead and thus increase receive queue capacity 1299 * - Less cache line misses at copyout() time 1300 * - Less work at consume_skb() (less alien page frag freeing) 1301 */ 1302 if (rmem > (sk->sk_rcvbuf >> 1)) { 1303 skb_condense(skb); 1304 1305 busy = busylock_acquire(sk); 1306 } 1307 size = skb->truesize; 1308 udp_set_dev_scratch(skb); 1309 1310 /* we drop only if the receive buf is full and the receive 1311 * queue contains some other skb 1312 */ 1313 rmem = atomic_add_return(size, &sk->sk_rmem_alloc); 1314 if (rmem > (size + sk->sk_rcvbuf)) 1315 goto uncharge_drop; 1316 1317 spin_lock(&list->lock); 1318 if (size >= sk->sk_forward_alloc) { 1319 amt = sk_mem_pages(size); 1320 delta = amt << SK_MEM_QUANTUM_SHIFT; 1321 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) { 1322 err = -ENOBUFS; 1323 spin_unlock(&list->lock); 1324 goto uncharge_drop; 1325 } 1326 1327 sk->sk_forward_alloc += delta; 1328 } 1329 1330 sk->sk_forward_alloc -= size; 1331 1332 /* no need to setup a destructor, we will explicitly release the 1333 * forward allocated memory on dequeue 1334 */ 1335 sock_skb_set_dropcount(sk, skb); 1336 1337 __skb_queue_tail(list, skb); 1338 spin_unlock(&list->lock); 1339 1340 if (!sock_flag(sk, SOCK_DEAD)) 1341 sk->sk_data_ready(sk); 1342 1343 busylock_release(busy); 1344 return 0; 1345 1346 uncharge_drop: 1347 atomic_sub(skb->truesize, &sk->sk_rmem_alloc); 1348 1349 drop: 1350 atomic_inc(&sk->sk_drops); 1351 busylock_release(busy); 1352 return err; 1353 } 1354 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb); 1355 1356 void udp_destruct_sock(struct sock *sk) 1357 { 1358 /* reclaim completely the forward allocated memory */ 1359 struct udp_sock *up = udp_sk(sk); 1360 unsigned int total = 0; 1361 struct sk_buff *skb; 1362 1363 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue); 1364 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) { 1365 total += skb->truesize; 1366 kfree_skb(skb); 1367 } 1368 udp_rmem_release(sk, total, 0, true); 1369 1370 inet_sock_destruct(sk); 1371 } 1372 EXPORT_SYMBOL_GPL(udp_destruct_sock); 1373 1374 int udp_init_sock(struct sock *sk) 1375 { 1376 skb_queue_head_init(&udp_sk(sk)->reader_queue); 1377 sk->sk_destruct = udp_destruct_sock; 1378 return 0; 1379 } 1380 EXPORT_SYMBOL_GPL(udp_init_sock); 1381 1382 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) 1383 { 1384 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) { 1385 bool slow = lock_sock_fast(sk); 1386 1387 sk_peek_offset_bwd(sk, len); 1388 unlock_sock_fast(sk, slow); 1389 } 1390 1391 /* we cleared the head states previously only if the skb lacks any IP 1392 * options, see __udp_queue_rcv_skb(). 1393 */ 1394 if (unlikely(IPCB(skb)->opt.optlen > 0)) 1395 skb_release_head_state(skb); 1396 consume_stateless_skb(skb); 1397 } 1398 EXPORT_SYMBOL_GPL(skb_consume_udp); 1399 1400 static struct sk_buff *__first_packet_length(struct sock *sk, 1401 struct sk_buff_head *rcvq, 1402 int *total) 1403 { 1404 struct sk_buff *skb; 1405 1406 while ((skb = skb_peek(rcvq)) != NULL) { 1407 if (udp_lib_checksum_complete(skb)) { 1408 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, 1409 IS_UDPLITE(sk)); 1410 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, 1411 IS_UDPLITE(sk)); 1412 atomic_inc(&sk->sk_drops); 1413 __skb_unlink(skb, rcvq); 1414 *total += skb->truesize; 1415 kfree_skb(skb); 1416 } else { 1417 /* the csum related bits could be changed, refresh 1418 * the scratch area 1419 */ 1420 udp_set_dev_scratch(skb); 1421 break; 1422 } 1423 } 1424 return skb; 1425 } 1426 1427 /** 1428 * first_packet_length - return length of first packet in receive queue 1429 * @sk: socket 1430 * 1431 * Drops all bad checksum frames, until a valid one is found. 1432 * Returns the length of found skb, or -1 if none is found. 1433 */ 1434 static int first_packet_length(struct sock *sk) 1435 { 1436 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue; 1437 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1438 struct sk_buff *skb; 1439 int total = 0; 1440 int res; 1441 1442 spin_lock_bh(&rcvq->lock); 1443 skb = __first_packet_length(sk, rcvq, &total); 1444 if (!skb && !skb_queue_empty(sk_queue)) { 1445 spin_lock(&sk_queue->lock); 1446 skb_queue_splice_tail_init(sk_queue, rcvq); 1447 spin_unlock(&sk_queue->lock); 1448 1449 skb = __first_packet_length(sk, rcvq, &total); 1450 } 1451 res = skb ? skb->len : -1; 1452 if (total) 1453 udp_rmem_release(sk, total, 1, false); 1454 spin_unlock_bh(&rcvq->lock); 1455 return res; 1456 } 1457 1458 /* 1459 * IOCTL requests applicable to the UDP protocol 1460 */ 1461 1462 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1463 { 1464 switch (cmd) { 1465 case SIOCOUTQ: 1466 { 1467 int amount = sk_wmem_alloc_get(sk); 1468 1469 return put_user(amount, (int __user *)arg); 1470 } 1471 1472 case SIOCINQ: 1473 { 1474 int amount = max_t(int, 0, first_packet_length(sk)); 1475 1476 return put_user(amount, (int __user *)arg); 1477 } 1478 1479 default: 1480 return -ENOIOCTLCMD; 1481 } 1482 1483 return 0; 1484 } 1485 EXPORT_SYMBOL(udp_ioctl); 1486 1487 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, 1488 int noblock, int *peeked, int *off, int *err) 1489 { 1490 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1491 struct sk_buff_head *queue; 1492 struct sk_buff *last; 1493 long timeo; 1494 int error; 1495 1496 queue = &udp_sk(sk)->reader_queue; 1497 flags |= noblock ? MSG_DONTWAIT : 0; 1498 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 1499 do { 1500 struct sk_buff *skb; 1501 1502 error = sock_error(sk); 1503 if (error) 1504 break; 1505 1506 error = -EAGAIN; 1507 *peeked = 0; 1508 do { 1509 spin_lock_bh(&queue->lock); 1510 skb = __skb_try_recv_from_queue(sk, queue, flags, 1511 udp_skb_destructor, 1512 peeked, off, err, 1513 &last); 1514 if (skb) { 1515 spin_unlock_bh(&queue->lock); 1516 return skb; 1517 } 1518 1519 if (skb_queue_empty(sk_queue)) { 1520 spin_unlock_bh(&queue->lock); 1521 goto busy_check; 1522 } 1523 1524 /* refill the reader queue and walk it again 1525 * keep both queues locked to avoid re-acquiring 1526 * the sk_receive_queue lock if fwd memory scheduling 1527 * is needed. 1528 */ 1529 spin_lock(&sk_queue->lock); 1530 skb_queue_splice_tail_init(sk_queue, queue); 1531 1532 skb = __skb_try_recv_from_queue(sk, queue, flags, 1533 udp_skb_dtor_locked, 1534 peeked, off, err, 1535 &last); 1536 spin_unlock(&sk_queue->lock); 1537 spin_unlock_bh(&queue->lock); 1538 if (skb) 1539 return skb; 1540 1541 busy_check: 1542 if (!sk_can_busy_loop(sk)) 1543 break; 1544 1545 sk_busy_loop(sk, flags & MSG_DONTWAIT); 1546 } while (!skb_queue_empty(sk_queue)); 1547 1548 /* sk_queue is empty, reader_queue may contain peeked packets */ 1549 } while (timeo && 1550 !__skb_wait_for_more_packets(sk, &error, &timeo, 1551 (struct sk_buff *)sk_queue)); 1552 1553 *err = error; 1554 return NULL; 1555 } 1556 EXPORT_SYMBOL_GPL(__skb_recv_udp); 1557 1558 /* 1559 * This should be easy, if there is something there we 1560 * return it, otherwise we block. 1561 */ 1562 1563 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 1564 int flags, int *addr_len) 1565 { 1566 struct inet_sock *inet = inet_sk(sk); 1567 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 1568 struct sk_buff *skb; 1569 unsigned int ulen, copied; 1570 int peeked, peeking, off; 1571 int err; 1572 int is_udplite = IS_UDPLITE(sk); 1573 bool checksum_valid = false; 1574 1575 if (flags & MSG_ERRQUEUE) 1576 return ip_recv_error(sk, msg, len, addr_len); 1577 1578 try_again: 1579 peeking = off = sk_peek_offset(sk, flags); 1580 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err); 1581 if (!skb) 1582 return err; 1583 1584 ulen = udp_skb_len(skb); 1585 copied = len; 1586 if (copied > ulen - off) 1587 copied = ulen - off; 1588 else if (copied < ulen) 1589 msg->msg_flags |= MSG_TRUNC; 1590 1591 /* 1592 * If checksum is needed at all, try to do it while copying the 1593 * data. If the data is truncated, or if we only want a partial 1594 * coverage checksum (UDP-Lite), do it before the copy. 1595 */ 1596 1597 if (copied < ulen || peeking || 1598 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { 1599 checksum_valid = udp_skb_csum_unnecessary(skb) || 1600 !__udp_lib_checksum_complete(skb); 1601 if (!checksum_valid) 1602 goto csum_copy_err; 1603 } 1604 1605 if (checksum_valid || udp_skb_csum_unnecessary(skb)) { 1606 if (udp_skb_is_linear(skb)) 1607 err = copy_linear_skb(skb, copied, off, &msg->msg_iter); 1608 else 1609 err = skb_copy_datagram_msg(skb, off, msg, copied); 1610 } else { 1611 err = skb_copy_and_csum_datagram_msg(skb, off, msg); 1612 1613 if (err == -EINVAL) 1614 goto csum_copy_err; 1615 } 1616 1617 if (unlikely(err)) { 1618 if (!peeked) { 1619 atomic_inc(&sk->sk_drops); 1620 UDP_INC_STATS(sock_net(sk), 1621 UDP_MIB_INERRORS, is_udplite); 1622 } 1623 kfree_skb(skb); 1624 return err; 1625 } 1626 1627 if (!peeked) 1628 UDP_INC_STATS(sock_net(sk), 1629 UDP_MIB_INDATAGRAMS, is_udplite); 1630 1631 sock_recv_ts_and_drops(msg, sk, skb); 1632 1633 /* Copy the address. */ 1634 if (sin) { 1635 sin->sin_family = AF_INET; 1636 sin->sin_port = udp_hdr(skb)->source; 1637 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1638 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1639 *addr_len = sizeof(*sin); 1640 } 1641 if (inet->cmsg_flags) 1642 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off); 1643 1644 err = copied; 1645 if (flags & MSG_TRUNC) 1646 err = ulen; 1647 1648 skb_consume_udp(sk, skb, peeking ? -err : err); 1649 return err; 1650 1651 csum_copy_err: 1652 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, 1653 udp_skb_destructor)) { 1654 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1655 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1656 } 1657 kfree_skb(skb); 1658 1659 /* starting over for a new packet, but check if we need to yield */ 1660 cond_resched(); 1661 msg->msg_flags &= ~MSG_TRUNC; 1662 goto try_again; 1663 } 1664 1665 int __udp_disconnect(struct sock *sk, int flags) 1666 { 1667 struct inet_sock *inet = inet_sk(sk); 1668 /* 1669 * 1003.1g - break association. 1670 */ 1671 1672 sk->sk_state = TCP_CLOSE; 1673 inet->inet_daddr = 0; 1674 inet->inet_dport = 0; 1675 sock_rps_reset_rxhash(sk); 1676 sk->sk_bound_dev_if = 0; 1677 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1678 inet_reset_saddr(sk); 1679 1680 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1681 sk->sk_prot->unhash(sk); 1682 inet->inet_sport = 0; 1683 } 1684 sk_dst_reset(sk); 1685 return 0; 1686 } 1687 EXPORT_SYMBOL(__udp_disconnect); 1688 1689 int udp_disconnect(struct sock *sk, int flags) 1690 { 1691 lock_sock(sk); 1692 __udp_disconnect(sk, flags); 1693 release_sock(sk); 1694 return 0; 1695 } 1696 EXPORT_SYMBOL(udp_disconnect); 1697 1698 void udp_lib_unhash(struct sock *sk) 1699 { 1700 if (sk_hashed(sk)) { 1701 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1702 struct udp_hslot *hslot, *hslot2; 1703 1704 hslot = udp_hashslot(udptable, sock_net(sk), 1705 udp_sk(sk)->udp_port_hash); 1706 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1707 1708 spin_lock_bh(&hslot->lock); 1709 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1710 reuseport_detach_sock(sk); 1711 if (sk_del_node_init_rcu(sk)) { 1712 hslot->count--; 1713 inet_sk(sk)->inet_num = 0; 1714 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1715 1716 spin_lock(&hslot2->lock); 1717 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1718 hslot2->count--; 1719 spin_unlock(&hslot2->lock); 1720 } 1721 spin_unlock_bh(&hslot->lock); 1722 } 1723 } 1724 EXPORT_SYMBOL(udp_lib_unhash); 1725 1726 /* 1727 * inet_rcv_saddr was changed, we must rehash secondary hash 1728 */ 1729 void udp_lib_rehash(struct sock *sk, u16 newhash) 1730 { 1731 if (sk_hashed(sk)) { 1732 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1733 struct udp_hslot *hslot, *hslot2, *nhslot2; 1734 1735 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1736 nhslot2 = udp_hashslot2(udptable, newhash); 1737 udp_sk(sk)->udp_portaddr_hash = newhash; 1738 1739 if (hslot2 != nhslot2 || 1740 rcu_access_pointer(sk->sk_reuseport_cb)) { 1741 hslot = udp_hashslot(udptable, sock_net(sk), 1742 udp_sk(sk)->udp_port_hash); 1743 /* we must lock primary chain too */ 1744 spin_lock_bh(&hslot->lock); 1745 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1746 reuseport_detach_sock(sk); 1747 1748 if (hslot2 != nhslot2) { 1749 spin_lock(&hslot2->lock); 1750 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1751 hslot2->count--; 1752 spin_unlock(&hslot2->lock); 1753 1754 spin_lock(&nhslot2->lock); 1755 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1756 &nhslot2->head); 1757 nhslot2->count++; 1758 spin_unlock(&nhslot2->lock); 1759 } 1760 1761 spin_unlock_bh(&hslot->lock); 1762 } 1763 } 1764 } 1765 EXPORT_SYMBOL(udp_lib_rehash); 1766 1767 static void udp_v4_rehash(struct sock *sk) 1768 { 1769 u16 new_hash = udp4_portaddr_hash(sock_net(sk), 1770 inet_sk(sk)->inet_rcv_saddr, 1771 inet_sk(sk)->inet_num); 1772 udp_lib_rehash(sk, new_hash); 1773 } 1774 1775 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1776 { 1777 int rc; 1778 1779 if (inet_sk(sk)->inet_daddr) { 1780 sock_rps_save_rxhash(sk, skb); 1781 sk_mark_napi_id(sk, skb); 1782 sk_incoming_cpu_update(sk); 1783 } else { 1784 sk_mark_napi_id_once(sk, skb); 1785 } 1786 1787 /* At recvmsg() time we need skb->dst to process IP options-related 1788 * cmsg, elsewhere can we clear all pending head states while they are 1789 * hot in the cache 1790 */ 1791 if (likely(IPCB(skb)->opt.optlen == 0)) 1792 skb_release_head_state(skb); 1793 1794 rc = __udp_enqueue_schedule_skb(sk, skb); 1795 if (rc < 0) { 1796 int is_udplite = IS_UDPLITE(sk); 1797 1798 /* Note that an ENOMEM error is charged twice */ 1799 if (rc == -ENOMEM) 1800 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1801 is_udplite); 1802 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1803 kfree_skb(skb); 1804 trace_udp_fail_queue_rcv_skb(rc, sk); 1805 return -1; 1806 } 1807 1808 return 0; 1809 } 1810 1811 static struct static_key udp_encap_needed __read_mostly; 1812 void udp_encap_enable(void) 1813 { 1814 if (!static_key_enabled(&udp_encap_needed)) 1815 static_key_slow_inc(&udp_encap_needed); 1816 } 1817 EXPORT_SYMBOL(udp_encap_enable); 1818 1819 /* returns: 1820 * -1: error 1821 * 0: success 1822 * >0: "udp encap" protocol resubmission 1823 * 1824 * Note that in the success and error cases, the skb is assumed to 1825 * have either been requeued or freed. 1826 */ 1827 static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1828 { 1829 struct udp_sock *up = udp_sk(sk); 1830 int is_udplite = IS_UDPLITE(sk); 1831 1832 /* 1833 * Charge it to the socket, dropping if the queue is full. 1834 */ 1835 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1836 goto drop; 1837 nf_reset(skb); 1838 1839 if (static_key_false(&udp_encap_needed) && up->encap_type) { 1840 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 1841 1842 /* 1843 * This is an encapsulation socket so pass the skb to 1844 * the socket's udp_encap_rcv() hook. Otherwise, just 1845 * fall through and pass this up the UDP socket. 1846 * up->encap_rcv() returns the following value: 1847 * =0 if skb was successfully passed to the encap 1848 * handler or was discarded by it. 1849 * >0 if skb should be passed on to UDP. 1850 * <0 if skb should be resubmitted as proto -N 1851 */ 1852 1853 /* if we're overly short, let UDP handle it */ 1854 encap_rcv = ACCESS_ONCE(up->encap_rcv); 1855 if (encap_rcv) { 1856 int ret; 1857 1858 /* Verify checksum before giving to encap */ 1859 if (udp_lib_checksum_complete(skb)) 1860 goto csum_error; 1861 1862 ret = encap_rcv(sk, skb); 1863 if (ret <= 0) { 1864 __UDP_INC_STATS(sock_net(sk), 1865 UDP_MIB_INDATAGRAMS, 1866 is_udplite); 1867 return -ret; 1868 } 1869 } 1870 1871 /* FALLTHROUGH -- it's a UDP Packet */ 1872 } 1873 1874 /* 1875 * UDP-Lite specific tests, ignored on UDP sockets 1876 */ 1877 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1878 1879 /* 1880 * MIB statistics other than incrementing the error count are 1881 * disabled for the following two types of errors: these depend 1882 * on the application settings, not on the functioning of the 1883 * protocol stack as such. 1884 * 1885 * RFC 3828 here recommends (sec 3.3): "There should also be a 1886 * way ... to ... at least let the receiving application block 1887 * delivery of packets with coverage values less than a value 1888 * provided by the application." 1889 */ 1890 if (up->pcrlen == 0) { /* full coverage was set */ 1891 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n", 1892 UDP_SKB_CB(skb)->cscov, skb->len); 1893 goto drop; 1894 } 1895 /* The next case involves violating the min. coverage requested 1896 * by the receiver. This is subtle: if receiver wants x and x is 1897 * greater than the buffersize/MTU then receiver will complain 1898 * that it wants x while sender emits packets of smaller size y. 1899 * Therefore the above ...()->partial_cov statement is essential. 1900 */ 1901 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1902 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n", 1903 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1904 goto drop; 1905 } 1906 } 1907 1908 prefetch(&sk->sk_rmem_alloc); 1909 if (rcu_access_pointer(sk->sk_filter) && 1910 udp_lib_checksum_complete(skb)) 1911 goto csum_error; 1912 1913 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 1914 goto drop; 1915 1916 udp_csum_pull_header(skb); 1917 1918 ipv4_pktinfo_prepare(sk, skb); 1919 return __udp_queue_rcv_skb(sk, skb); 1920 1921 csum_error: 1922 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1923 drop: 1924 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1925 atomic_inc(&sk->sk_drops); 1926 kfree_skb(skb); 1927 return -1; 1928 } 1929 1930 /* For TCP sockets, sk_rx_dst is protected by socket lock 1931 * For UDP, we use xchg() to guard against concurrent changes. 1932 */ 1933 static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 1934 { 1935 struct dst_entry *old; 1936 1937 if (dst_hold_safe(dst)) { 1938 old = xchg(&sk->sk_rx_dst, dst); 1939 dst_release(old); 1940 } 1941 } 1942 1943 /* 1944 * Multicasts and broadcasts go to each listener. 1945 * 1946 * Note: called only from the BH handler context. 1947 */ 1948 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 1949 struct udphdr *uh, 1950 __be32 saddr, __be32 daddr, 1951 struct udp_table *udptable, 1952 int proto) 1953 { 1954 struct sock *sk, *first = NULL; 1955 unsigned short hnum = ntohs(uh->dest); 1956 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 1957 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 1958 unsigned int offset = offsetof(typeof(*sk), sk_node); 1959 int dif = skb->dev->ifindex; 1960 struct hlist_node *node; 1961 struct sk_buff *nskb; 1962 1963 if (use_hash2) { 1964 hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & 1965 udptable->mask; 1966 hash2 = udp4_portaddr_hash(net, daddr, hnum) & udptable->mask; 1967 start_lookup: 1968 hslot = &udptable->hash2[hash2]; 1969 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 1970 } 1971 1972 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 1973 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr, 1974 uh->source, saddr, dif, hnum)) 1975 continue; 1976 1977 if (!first) { 1978 first = sk; 1979 continue; 1980 } 1981 nskb = skb_clone(skb, GFP_ATOMIC); 1982 1983 if (unlikely(!nskb)) { 1984 atomic_inc(&sk->sk_drops); 1985 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 1986 IS_UDPLITE(sk)); 1987 __UDP_INC_STATS(net, UDP_MIB_INERRORS, 1988 IS_UDPLITE(sk)); 1989 continue; 1990 } 1991 if (udp_queue_rcv_skb(sk, nskb) > 0) 1992 consume_skb(nskb); 1993 } 1994 1995 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 1996 if (use_hash2 && hash2 != hash2_any) { 1997 hash2 = hash2_any; 1998 goto start_lookup; 1999 } 2000 2001 if (first) { 2002 if (udp_queue_rcv_skb(first, skb) > 0) 2003 consume_skb(skb); 2004 } else { 2005 kfree_skb(skb); 2006 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 2007 proto == IPPROTO_UDPLITE); 2008 } 2009 return 0; 2010 } 2011 2012 /* Initialize UDP checksum. If exited with zero value (success), 2013 * CHECKSUM_UNNECESSARY means, that no more checks are required. 2014 * Otherwise, csum completion requires chacksumming packet body, 2015 * including udp header and folding it to skb->csum. 2016 */ 2017 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 2018 int proto) 2019 { 2020 int err; 2021 2022 UDP_SKB_CB(skb)->partial_cov = 0; 2023 UDP_SKB_CB(skb)->cscov = skb->len; 2024 2025 if (proto == IPPROTO_UDPLITE) { 2026 err = udplite_checksum_init(skb, uh); 2027 if (err) 2028 return err; 2029 } 2030 2031 /* Note, we are only interested in != 0 or == 0, thus the 2032 * force to int. 2033 */ 2034 return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check, 2035 inet_compute_pseudo); 2036 } 2037 2038 /* 2039 * All we need to do is get the socket, and then do a checksum. 2040 */ 2041 2042 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 2043 int proto) 2044 { 2045 struct sock *sk; 2046 struct udphdr *uh; 2047 unsigned short ulen; 2048 struct rtable *rt = skb_rtable(skb); 2049 __be32 saddr, daddr; 2050 struct net *net = dev_net(skb->dev); 2051 2052 /* 2053 * Validate the packet. 2054 */ 2055 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 2056 goto drop; /* No space for header. */ 2057 2058 uh = udp_hdr(skb); 2059 ulen = ntohs(uh->len); 2060 saddr = ip_hdr(skb)->saddr; 2061 daddr = ip_hdr(skb)->daddr; 2062 2063 if (ulen > skb->len) 2064 goto short_packet; 2065 2066 if (proto == IPPROTO_UDP) { 2067 /* UDP validates ulen. */ 2068 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 2069 goto short_packet; 2070 uh = udp_hdr(skb); 2071 } 2072 2073 if (udp4_csum_init(skb, uh, proto)) 2074 goto csum_error; 2075 2076 sk = skb_steal_sock(skb); 2077 if (sk) { 2078 struct dst_entry *dst = skb_dst(skb); 2079 int ret; 2080 2081 if (unlikely(sk->sk_rx_dst != dst)) 2082 udp_sk_rx_dst_set(sk, dst); 2083 2084 ret = udp_queue_rcv_skb(sk, skb); 2085 sock_put(sk); 2086 /* a return value > 0 means to resubmit the input, but 2087 * it wants the return to be -protocol, or 0 2088 */ 2089 if (ret > 0) 2090 return -ret; 2091 return 0; 2092 } 2093 2094 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 2095 return __udp4_lib_mcast_deliver(net, skb, uh, 2096 saddr, daddr, udptable, proto); 2097 2098 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 2099 if (sk) { 2100 int ret; 2101 2102 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 2103 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, 2104 inet_compute_pseudo); 2105 2106 ret = udp_queue_rcv_skb(sk, skb); 2107 2108 /* a return value > 0 means to resubmit the input, but 2109 * it wants the return to be -protocol, or 0 2110 */ 2111 if (ret > 0) 2112 return -ret; 2113 return 0; 2114 } 2115 2116 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 2117 goto drop; 2118 nf_reset(skb); 2119 2120 /* No socket. Drop packet silently, if checksum is wrong */ 2121 if (udp_lib_checksum_complete(skb)) 2122 goto csum_error; 2123 2124 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 2125 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 2126 2127 /* 2128 * Hmm. We got an UDP packet to a port to which we 2129 * don't wanna listen. Ignore it. 2130 */ 2131 kfree_skb(skb); 2132 return 0; 2133 2134 short_packet: 2135 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 2136 proto == IPPROTO_UDPLITE ? "Lite" : "", 2137 &saddr, ntohs(uh->source), 2138 ulen, skb->len, 2139 &daddr, ntohs(uh->dest)); 2140 goto drop; 2141 2142 csum_error: 2143 /* 2144 * RFC1122: OK. Discards the bad packet silently (as far as 2145 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 2146 */ 2147 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 2148 proto == IPPROTO_UDPLITE ? "Lite" : "", 2149 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 2150 ulen); 2151 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 2152 drop: 2153 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 2154 kfree_skb(skb); 2155 return 0; 2156 } 2157 2158 /* We can only early demux multicast if there is a single matching socket. 2159 * If more than one socket found returns NULL 2160 */ 2161 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, 2162 __be16 loc_port, __be32 loc_addr, 2163 __be16 rmt_port, __be32 rmt_addr, 2164 int dif) 2165 { 2166 struct sock *sk, *result; 2167 unsigned short hnum = ntohs(loc_port); 2168 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask); 2169 struct udp_hslot *hslot = &udp_table.hash[slot]; 2170 2171 /* Do not bother scanning a too big list */ 2172 if (hslot->count > 10) 2173 return NULL; 2174 2175 result = NULL; 2176 sk_for_each_rcu(sk, &hslot->head) { 2177 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr, 2178 rmt_port, rmt_addr, dif, hnum)) { 2179 if (result) 2180 return NULL; 2181 result = sk; 2182 } 2183 } 2184 2185 return result; 2186 } 2187 2188 /* For unicast we should only early demux connected sockets or we can 2189 * break forwarding setups. The chains here can be long so only check 2190 * if the first socket is an exact match and if not move on. 2191 */ 2192 static struct sock *__udp4_lib_demux_lookup(struct net *net, 2193 __be16 loc_port, __be32 loc_addr, 2194 __be16 rmt_port, __be32 rmt_addr, 2195 int dif) 2196 { 2197 unsigned short hnum = ntohs(loc_port); 2198 unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum); 2199 unsigned int slot2 = hash2 & udp_table.mask; 2200 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 2201 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); 2202 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 2203 struct sock *sk; 2204 2205 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 2206 if (INET_MATCH(sk, net, acookie, rmt_addr, 2207 loc_addr, ports, dif)) 2208 return sk; 2209 /* Only check first socket in chain */ 2210 break; 2211 } 2212 return NULL; 2213 } 2214 2215 void udp_v4_early_demux(struct sk_buff *skb) 2216 { 2217 struct net *net = dev_net(skb->dev); 2218 const struct iphdr *iph; 2219 const struct udphdr *uh; 2220 struct sock *sk = NULL; 2221 struct dst_entry *dst; 2222 int dif = skb->dev->ifindex; 2223 int ours; 2224 2225 /* validate the packet */ 2226 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) 2227 return; 2228 2229 iph = ip_hdr(skb); 2230 uh = udp_hdr(skb); 2231 2232 if (skb->pkt_type == PACKET_BROADCAST || 2233 skb->pkt_type == PACKET_MULTICAST) { 2234 struct in_device *in_dev = __in_dev_get_rcu(skb->dev); 2235 2236 if (!in_dev) 2237 return; 2238 2239 /* we are supposed to accept bcast packets */ 2240 if (skb->pkt_type == PACKET_MULTICAST) { 2241 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, 2242 iph->protocol); 2243 if (!ours) 2244 return; 2245 } 2246 2247 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, 2248 uh->source, iph->saddr, dif); 2249 } else if (skb->pkt_type == PACKET_HOST) { 2250 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, 2251 uh->source, iph->saddr, dif); 2252 } 2253 2254 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 2255 return; 2256 2257 skb->sk = sk; 2258 skb->destructor = sock_efree; 2259 dst = READ_ONCE(sk->sk_rx_dst); 2260 2261 if (dst) 2262 dst = dst_check(dst, 0); 2263 if (dst) { 2264 /* set noref for now. 2265 * any place which wants to hold dst has to call 2266 * dst_hold_safe() 2267 */ 2268 skb_dst_set_noref(skb, dst); 2269 } 2270 } 2271 2272 int udp_rcv(struct sk_buff *skb) 2273 { 2274 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 2275 } 2276 2277 void udp_destroy_sock(struct sock *sk) 2278 { 2279 struct udp_sock *up = udp_sk(sk); 2280 bool slow = lock_sock_fast(sk); 2281 udp_flush_pending_frames(sk); 2282 unlock_sock_fast(sk, slow); 2283 if (static_key_false(&udp_encap_needed) && up->encap_type) { 2284 void (*encap_destroy)(struct sock *sk); 2285 encap_destroy = ACCESS_ONCE(up->encap_destroy); 2286 if (encap_destroy) 2287 encap_destroy(sk); 2288 } 2289 } 2290 2291 /* 2292 * Socket option code for UDP 2293 */ 2294 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 2295 char __user *optval, unsigned int optlen, 2296 int (*push_pending_frames)(struct sock *)) 2297 { 2298 struct udp_sock *up = udp_sk(sk); 2299 int val, valbool; 2300 int err = 0; 2301 int is_udplite = IS_UDPLITE(sk); 2302 2303 if (optlen < sizeof(int)) 2304 return -EINVAL; 2305 2306 if (get_user(val, (int __user *)optval)) 2307 return -EFAULT; 2308 2309 valbool = val ? 1 : 0; 2310 2311 switch (optname) { 2312 case UDP_CORK: 2313 if (val != 0) { 2314 up->corkflag = 1; 2315 } else { 2316 up->corkflag = 0; 2317 lock_sock(sk); 2318 push_pending_frames(sk); 2319 release_sock(sk); 2320 } 2321 break; 2322 2323 case UDP_ENCAP: 2324 switch (val) { 2325 case 0: 2326 case UDP_ENCAP_ESPINUDP: 2327 case UDP_ENCAP_ESPINUDP_NON_IKE: 2328 up->encap_rcv = xfrm4_udp_encap_rcv; 2329 /* FALLTHROUGH */ 2330 case UDP_ENCAP_L2TPINUDP: 2331 up->encap_type = val; 2332 udp_encap_enable(); 2333 break; 2334 default: 2335 err = -ENOPROTOOPT; 2336 break; 2337 } 2338 break; 2339 2340 case UDP_NO_CHECK6_TX: 2341 up->no_check6_tx = valbool; 2342 break; 2343 2344 case UDP_NO_CHECK6_RX: 2345 up->no_check6_rx = valbool; 2346 break; 2347 2348 /* 2349 * UDP-Lite's partial checksum coverage (RFC 3828). 2350 */ 2351 /* The sender sets actual checksum coverage length via this option. 2352 * The case coverage > packet length is handled by send module. */ 2353 case UDPLITE_SEND_CSCOV: 2354 if (!is_udplite) /* Disable the option on UDP sockets */ 2355 return -ENOPROTOOPT; 2356 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 2357 val = 8; 2358 else if (val > USHRT_MAX) 2359 val = USHRT_MAX; 2360 up->pcslen = val; 2361 up->pcflag |= UDPLITE_SEND_CC; 2362 break; 2363 2364 /* The receiver specifies a minimum checksum coverage value. To make 2365 * sense, this should be set to at least 8 (as done below). If zero is 2366 * used, this again means full checksum coverage. */ 2367 case UDPLITE_RECV_CSCOV: 2368 if (!is_udplite) /* Disable the option on UDP sockets */ 2369 return -ENOPROTOOPT; 2370 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 2371 val = 8; 2372 else if (val > USHRT_MAX) 2373 val = USHRT_MAX; 2374 up->pcrlen = val; 2375 up->pcflag |= UDPLITE_RECV_CC; 2376 break; 2377 2378 default: 2379 err = -ENOPROTOOPT; 2380 break; 2381 } 2382 2383 return err; 2384 } 2385 EXPORT_SYMBOL(udp_lib_setsockopt); 2386 2387 int udp_setsockopt(struct sock *sk, int level, int optname, 2388 char __user *optval, unsigned int optlen) 2389 { 2390 if (level == SOL_UDP || level == SOL_UDPLITE) 2391 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2392 udp_push_pending_frames); 2393 return ip_setsockopt(sk, level, optname, optval, optlen); 2394 } 2395 2396 #ifdef CONFIG_COMPAT 2397 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 2398 char __user *optval, unsigned int optlen) 2399 { 2400 if (level == SOL_UDP || level == SOL_UDPLITE) 2401 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2402 udp_push_pending_frames); 2403 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 2404 } 2405 #endif 2406 2407 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 2408 char __user *optval, int __user *optlen) 2409 { 2410 struct udp_sock *up = udp_sk(sk); 2411 int val, len; 2412 2413 if (get_user(len, optlen)) 2414 return -EFAULT; 2415 2416 len = min_t(unsigned int, len, sizeof(int)); 2417 2418 if (len < 0) 2419 return -EINVAL; 2420 2421 switch (optname) { 2422 case UDP_CORK: 2423 val = up->corkflag; 2424 break; 2425 2426 case UDP_ENCAP: 2427 val = up->encap_type; 2428 break; 2429 2430 case UDP_NO_CHECK6_TX: 2431 val = up->no_check6_tx; 2432 break; 2433 2434 case UDP_NO_CHECK6_RX: 2435 val = up->no_check6_rx; 2436 break; 2437 2438 /* The following two cannot be changed on UDP sockets, the return is 2439 * always 0 (which corresponds to the full checksum coverage of UDP). */ 2440 case UDPLITE_SEND_CSCOV: 2441 val = up->pcslen; 2442 break; 2443 2444 case UDPLITE_RECV_CSCOV: 2445 val = up->pcrlen; 2446 break; 2447 2448 default: 2449 return -ENOPROTOOPT; 2450 } 2451 2452 if (put_user(len, optlen)) 2453 return -EFAULT; 2454 if (copy_to_user(optval, &val, len)) 2455 return -EFAULT; 2456 return 0; 2457 } 2458 EXPORT_SYMBOL(udp_lib_getsockopt); 2459 2460 int udp_getsockopt(struct sock *sk, int level, int optname, 2461 char __user *optval, int __user *optlen) 2462 { 2463 if (level == SOL_UDP || level == SOL_UDPLITE) 2464 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2465 return ip_getsockopt(sk, level, optname, optval, optlen); 2466 } 2467 2468 #ifdef CONFIG_COMPAT 2469 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 2470 char __user *optval, int __user *optlen) 2471 { 2472 if (level == SOL_UDP || level == SOL_UDPLITE) 2473 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2474 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 2475 } 2476 #endif 2477 /** 2478 * udp_poll - wait for a UDP event. 2479 * @file - file struct 2480 * @sock - socket 2481 * @wait - poll table 2482 * 2483 * This is same as datagram poll, except for the special case of 2484 * blocking sockets. If application is using a blocking fd 2485 * and a packet with checksum error is in the queue; 2486 * then it could get return from select indicating data available 2487 * but then block when reading it. Add special case code 2488 * to work around these arguably broken applications. 2489 */ 2490 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 2491 { 2492 unsigned int mask = datagram_poll(file, sock, wait); 2493 struct sock *sk = sock->sk; 2494 2495 if (!skb_queue_empty(&udp_sk(sk)->reader_queue)) 2496 mask |= POLLIN | POLLRDNORM; 2497 2498 sock_rps_record_flow(sk); 2499 2500 /* Check for false positives due to checksum errors */ 2501 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 2502 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1) 2503 mask &= ~(POLLIN | POLLRDNORM); 2504 2505 return mask; 2506 2507 } 2508 EXPORT_SYMBOL(udp_poll); 2509 2510 int udp_abort(struct sock *sk, int err) 2511 { 2512 lock_sock(sk); 2513 2514 sk->sk_err = err; 2515 sk->sk_error_report(sk); 2516 __udp_disconnect(sk, 0); 2517 2518 release_sock(sk); 2519 2520 return 0; 2521 } 2522 EXPORT_SYMBOL_GPL(udp_abort); 2523 2524 struct proto udp_prot = { 2525 .name = "UDP", 2526 .owner = THIS_MODULE, 2527 .close = udp_lib_close, 2528 .connect = ip4_datagram_connect, 2529 .disconnect = udp_disconnect, 2530 .ioctl = udp_ioctl, 2531 .init = udp_init_sock, 2532 .destroy = udp_destroy_sock, 2533 .setsockopt = udp_setsockopt, 2534 .getsockopt = udp_getsockopt, 2535 .sendmsg = udp_sendmsg, 2536 .recvmsg = udp_recvmsg, 2537 .sendpage = udp_sendpage, 2538 .release_cb = ip4_datagram_release_cb, 2539 .hash = udp_lib_hash, 2540 .unhash = udp_lib_unhash, 2541 .rehash = udp_v4_rehash, 2542 .get_port = udp_v4_get_port, 2543 .memory_allocated = &udp_memory_allocated, 2544 .sysctl_mem = sysctl_udp_mem, 2545 .sysctl_wmem = &sysctl_udp_wmem_min, 2546 .sysctl_rmem = &sysctl_udp_rmem_min, 2547 .obj_size = sizeof(struct udp_sock), 2548 .h.udp_table = &udp_table, 2549 #ifdef CONFIG_COMPAT 2550 .compat_setsockopt = compat_udp_setsockopt, 2551 .compat_getsockopt = compat_udp_getsockopt, 2552 #endif 2553 .diag_destroy = udp_abort, 2554 }; 2555 EXPORT_SYMBOL(udp_prot); 2556 2557 /* ------------------------------------------------------------------------ */ 2558 #ifdef CONFIG_PROC_FS 2559 2560 static struct sock *udp_get_first(struct seq_file *seq, int start) 2561 { 2562 struct sock *sk; 2563 struct udp_iter_state *state = seq->private; 2564 struct net *net = seq_file_net(seq); 2565 2566 for (state->bucket = start; state->bucket <= state->udp_table->mask; 2567 ++state->bucket) { 2568 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; 2569 2570 if (hlist_empty(&hslot->head)) 2571 continue; 2572 2573 spin_lock_bh(&hslot->lock); 2574 sk_for_each(sk, &hslot->head) { 2575 if (!net_eq(sock_net(sk), net)) 2576 continue; 2577 if (sk->sk_family == state->family) 2578 goto found; 2579 } 2580 spin_unlock_bh(&hslot->lock); 2581 } 2582 sk = NULL; 2583 found: 2584 return sk; 2585 } 2586 2587 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2588 { 2589 struct udp_iter_state *state = seq->private; 2590 struct net *net = seq_file_net(seq); 2591 2592 do { 2593 sk = sk_next(sk); 2594 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); 2595 2596 if (!sk) { 2597 if (state->bucket <= state->udp_table->mask) 2598 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2599 return udp_get_first(seq, state->bucket + 1); 2600 } 2601 return sk; 2602 } 2603 2604 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2605 { 2606 struct sock *sk = udp_get_first(seq, 0); 2607 2608 if (sk) 2609 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2610 --pos; 2611 return pos ? NULL : sk; 2612 } 2613 2614 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2615 { 2616 struct udp_iter_state *state = seq->private; 2617 state->bucket = MAX_UDP_PORTS; 2618 2619 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2620 } 2621 2622 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2623 { 2624 struct sock *sk; 2625 2626 if (v == SEQ_START_TOKEN) 2627 sk = udp_get_idx(seq, 0); 2628 else 2629 sk = udp_get_next(seq, v); 2630 2631 ++*pos; 2632 return sk; 2633 } 2634 2635 static void udp_seq_stop(struct seq_file *seq, void *v) 2636 { 2637 struct udp_iter_state *state = seq->private; 2638 2639 if (state->bucket <= state->udp_table->mask) 2640 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2641 } 2642 2643 int udp_seq_open(struct inode *inode, struct file *file) 2644 { 2645 struct udp_seq_afinfo *afinfo = PDE_DATA(inode); 2646 struct udp_iter_state *s; 2647 int err; 2648 2649 err = seq_open_net(inode, file, &afinfo->seq_ops, 2650 sizeof(struct udp_iter_state)); 2651 if (err < 0) 2652 return err; 2653 2654 s = ((struct seq_file *)file->private_data)->private; 2655 s->family = afinfo->family; 2656 s->udp_table = afinfo->udp_table; 2657 return err; 2658 } 2659 EXPORT_SYMBOL(udp_seq_open); 2660 2661 /* ------------------------------------------------------------------------ */ 2662 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) 2663 { 2664 struct proc_dir_entry *p; 2665 int rc = 0; 2666 2667 afinfo->seq_ops.start = udp_seq_start; 2668 afinfo->seq_ops.next = udp_seq_next; 2669 afinfo->seq_ops.stop = udp_seq_stop; 2670 2671 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 2672 afinfo->seq_fops, afinfo); 2673 if (!p) 2674 rc = -ENOMEM; 2675 return rc; 2676 } 2677 EXPORT_SYMBOL(udp_proc_register); 2678 2679 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 2680 { 2681 remove_proc_entry(afinfo->name, net->proc_net); 2682 } 2683 EXPORT_SYMBOL(udp_proc_unregister); 2684 2685 /* ------------------------------------------------------------------------ */ 2686 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2687 int bucket) 2688 { 2689 struct inet_sock *inet = inet_sk(sp); 2690 __be32 dest = inet->inet_daddr; 2691 __be32 src = inet->inet_rcv_saddr; 2692 __u16 destp = ntohs(inet->inet_dport); 2693 __u16 srcp = ntohs(inet->inet_sport); 2694 2695 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2696 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 2697 bucket, src, srcp, dest, destp, sp->sk_state, 2698 sk_wmem_alloc_get(sp), 2699 sk_rmem_alloc_get(sp), 2700 0, 0L, 0, 2701 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2702 0, sock_i_ino(sp), 2703 refcount_read(&sp->sk_refcnt), sp, 2704 atomic_read(&sp->sk_drops)); 2705 } 2706 2707 int udp4_seq_show(struct seq_file *seq, void *v) 2708 { 2709 seq_setwidth(seq, 127); 2710 if (v == SEQ_START_TOKEN) 2711 seq_puts(seq, " sl local_address rem_address st tx_queue " 2712 "rx_queue tr tm->when retrnsmt uid timeout " 2713 "inode ref pointer drops"); 2714 else { 2715 struct udp_iter_state *state = seq->private; 2716 2717 udp4_format_sock(v, seq, state->bucket); 2718 } 2719 seq_pad(seq, '\n'); 2720 return 0; 2721 } 2722 2723 static const struct file_operations udp_afinfo_seq_fops = { 2724 .owner = THIS_MODULE, 2725 .open = udp_seq_open, 2726 .read = seq_read, 2727 .llseek = seq_lseek, 2728 .release = seq_release_net 2729 }; 2730 2731 /* ------------------------------------------------------------------------ */ 2732 static struct udp_seq_afinfo udp4_seq_afinfo = { 2733 .name = "udp", 2734 .family = AF_INET, 2735 .udp_table = &udp_table, 2736 .seq_fops = &udp_afinfo_seq_fops, 2737 .seq_ops = { 2738 .show = udp4_seq_show, 2739 }, 2740 }; 2741 2742 static int __net_init udp4_proc_init_net(struct net *net) 2743 { 2744 return udp_proc_register(net, &udp4_seq_afinfo); 2745 } 2746 2747 static void __net_exit udp4_proc_exit_net(struct net *net) 2748 { 2749 udp_proc_unregister(net, &udp4_seq_afinfo); 2750 } 2751 2752 static struct pernet_operations udp4_net_ops = { 2753 .init = udp4_proc_init_net, 2754 .exit = udp4_proc_exit_net, 2755 }; 2756 2757 int __init udp4_proc_init(void) 2758 { 2759 return register_pernet_subsys(&udp4_net_ops); 2760 } 2761 2762 void udp4_proc_exit(void) 2763 { 2764 unregister_pernet_subsys(&udp4_net_ops); 2765 } 2766 #endif /* CONFIG_PROC_FS */ 2767 2768 static __initdata unsigned long uhash_entries; 2769 static int __init set_uhash_entries(char *str) 2770 { 2771 ssize_t ret; 2772 2773 if (!str) 2774 return 0; 2775 2776 ret = kstrtoul(str, 0, &uhash_entries); 2777 if (ret) 2778 return 0; 2779 2780 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2781 uhash_entries = UDP_HTABLE_SIZE_MIN; 2782 return 1; 2783 } 2784 __setup("uhash_entries=", set_uhash_entries); 2785 2786 void __init udp_table_init(struct udp_table *table, const char *name) 2787 { 2788 unsigned int i; 2789 2790 table->hash = alloc_large_system_hash(name, 2791 2 * sizeof(struct udp_hslot), 2792 uhash_entries, 2793 21, /* one slot per 2 MB */ 2794 0, 2795 &table->log, 2796 &table->mask, 2797 UDP_HTABLE_SIZE_MIN, 2798 64 * 1024); 2799 2800 table->hash2 = table->hash + (table->mask + 1); 2801 for (i = 0; i <= table->mask; i++) { 2802 INIT_HLIST_HEAD(&table->hash[i].head); 2803 table->hash[i].count = 0; 2804 spin_lock_init(&table->hash[i].lock); 2805 } 2806 for (i = 0; i <= table->mask; i++) { 2807 INIT_HLIST_HEAD(&table->hash2[i].head); 2808 table->hash2[i].count = 0; 2809 spin_lock_init(&table->hash2[i].lock); 2810 } 2811 } 2812 2813 u32 udp_flow_hashrnd(void) 2814 { 2815 static u32 hashrnd __read_mostly; 2816 2817 net_get_random_once(&hashrnd, sizeof(hashrnd)); 2818 2819 return hashrnd; 2820 } 2821 EXPORT_SYMBOL(udp_flow_hashrnd); 2822 2823 void __init udp_init(void) 2824 { 2825 unsigned long limit; 2826 unsigned int i; 2827 2828 udp_table_init(&udp_table, "UDP"); 2829 limit = nr_free_buffer_pages() / 8; 2830 limit = max(limit, 128UL); 2831 sysctl_udp_mem[0] = limit / 4 * 3; 2832 sysctl_udp_mem[1] = limit; 2833 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 2834 2835 sysctl_udp_rmem_min = SK_MEM_QUANTUM; 2836 sysctl_udp_wmem_min = SK_MEM_QUANTUM; 2837 2838 /* 16 spinlocks per cpu */ 2839 udp_busylocks_log = ilog2(nr_cpu_ids) + 4; 2840 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log, 2841 GFP_KERNEL); 2842 if (!udp_busylocks) 2843 panic("UDP: failed to alloc udp_busylocks\n"); 2844 for (i = 0; i < (1U << udp_busylocks_log); i++) 2845 spin_lock_init(udp_busylocks + i); 2846 } 2847