1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * The User Datagram Protocol (UDP). 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 12 * Alan Cox, <alan@lxorguk.ukuu.org.uk> 13 * Hirokazu Takahashi, <taka@valinux.co.jp> 14 * 15 * Fixes: 16 * Alan Cox : verify_area() calls 17 * Alan Cox : stopped close while in use off icmp 18 * messages. Not a fix but a botch that 19 * for udp at least is 'valid'. 20 * Alan Cox : Fixed icmp handling properly 21 * Alan Cox : Correct error for oversized datagrams 22 * Alan Cox : Tidied select() semantics. 23 * Alan Cox : udp_err() fixed properly, also now 24 * select and read wake correctly on errors 25 * Alan Cox : udp_send verify_area moved to avoid mem leak 26 * Alan Cox : UDP can count its memory 27 * Alan Cox : send to an unknown connection causes 28 * an ECONNREFUSED off the icmp, but 29 * does NOT close. 30 * Alan Cox : Switched to new sk_buff handlers. No more backlog! 31 * Alan Cox : Using generic datagram code. Even smaller and the PEEK 32 * bug no longer crashes it. 33 * Fred Van Kempen : Net2e support for sk->broadcast. 34 * Alan Cox : Uses skb_free_datagram 35 * Alan Cox : Added get/set sockopt support. 36 * Alan Cox : Broadcasting without option set returns EACCES. 37 * Alan Cox : No wakeup calls. Instead we now use the callbacks. 38 * Alan Cox : Use ip_tos and ip_ttl 39 * Alan Cox : SNMP Mibs 40 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. 41 * Matt Dillon : UDP length checks. 42 * Alan Cox : Smarter af_inet used properly. 43 * Alan Cox : Use new kernel side addressing. 44 * Alan Cox : Incorrect return on truncated datagram receive. 45 * Arnt Gulbrandsen : New udp_send and stuff 46 * Alan Cox : Cache last socket 47 * Alan Cox : Route cache 48 * Jon Peatfield : Minor efficiency fix to sendto(). 49 * Mike Shaver : RFC1122 checks. 50 * Alan Cox : Nonblocking error fix. 51 * Willy Konynenberg : Transparent proxying support. 52 * Mike McLagan : Routing by source 53 * David S. Miller : New socket lookup architecture. 54 * Last socket cache retained as it 55 * does have a high hit rate. 56 * Olaf Kirch : Don't linearise iovec on sendmsg. 57 * Andi Kleen : Some cleanups, cache destination entry 58 * for connect. 59 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 60 * Melvin Smith : Check msg_name not msg_namelen in sendto(), 61 * return ENOTCONN for unconnected sockets (POSIX) 62 * Janos Farkas : don't deliver multi/broadcasts to a different 63 * bound-to-device socket 64 * Hirokazu Takahashi : HW checksumming for outgoing UDP 65 * datagrams. 66 * Hirokazu Takahashi : sendfile() on UDP works now. 67 * Arnaldo C. Melo : convert /proc/net/udp to seq_file 68 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 69 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind 70 * a single port at the same time. 71 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support 72 * James Chapman : Add L2TP encapsulation type. 73 */ 74 75 #define pr_fmt(fmt) "UDP: " fmt 76 77 #include <linux/uaccess.h> 78 #include <asm/ioctls.h> 79 #include <linux/memblock.h> 80 #include <linux/highmem.h> 81 #include <linux/swap.h> 82 #include <linux/types.h> 83 #include <linux/fcntl.h> 84 #include <linux/module.h> 85 #include <linux/socket.h> 86 #include <linux/sockios.h> 87 #include <linux/igmp.h> 88 #include <linux/inetdevice.h> 89 #include <linux/in.h> 90 #include <linux/errno.h> 91 #include <linux/timer.h> 92 #include <linux/mm.h> 93 #include <linux/inet.h> 94 #include <linux/netdevice.h> 95 #include <linux/slab.h> 96 #include <net/tcp_states.h> 97 #include <linux/skbuff.h> 98 #include <linux/proc_fs.h> 99 #include <linux/seq_file.h> 100 #include <net/net_namespace.h> 101 #include <net/icmp.h> 102 #include <net/inet_hashtables.h> 103 #include <net/ip_tunnels.h> 104 #include <net/route.h> 105 #include <net/checksum.h> 106 #include <net/xfrm.h> 107 #include <trace/events/udp.h> 108 #include <linux/static_key.h> 109 #include <linux/btf_ids.h> 110 #include <trace/events/skb.h> 111 #include <net/busy_poll.h> 112 #include "udp_impl.h" 113 #include <net/sock_reuseport.h> 114 #include <net/addrconf.h> 115 #include <net/udp_tunnel.h> 116 #if IS_ENABLED(CONFIG_IPV6) 117 #include <net/ipv6_stubs.h> 118 #endif 119 120 struct udp_table udp_table __read_mostly; 121 EXPORT_SYMBOL(udp_table); 122 123 long sysctl_udp_mem[3] __read_mostly; 124 EXPORT_SYMBOL(sysctl_udp_mem); 125 126 atomic_long_t udp_memory_allocated; 127 EXPORT_SYMBOL(udp_memory_allocated); 128 129 #define MAX_UDP_PORTS 65536 130 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 131 132 static int udp_lib_lport_inuse(struct net *net, __u16 num, 133 const struct udp_hslot *hslot, 134 unsigned long *bitmap, 135 struct sock *sk, unsigned int log) 136 { 137 struct sock *sk2; 138 kuid_t uid = sock_i_uid(sk); 139 140 sk_for_each(sk2, &hslot->head) { 141 if (net_eq(sock_net(sk2), net) && 142 sk2 != sk && 143 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 144 (!sk2->sk_reuse || !sk->sk_reuse) && 145 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 146 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 147 inet_rcv_saddr_equal(sk, sk2, true)) { 148 if (sk2->sk_reuseport && sk->sk_reuseport && 149 !rcu_access_pointer(sk->sk_reuseport_cb) && 150 uid_eq(uid, sock_i_uid(sk2))) { 151 if (!bitmap) 152 return 0; 153 } else { 154 if (!bitmap) 155 return 1; 156 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 157 bitmap); 158 } 159 } 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 { 172 struct sock *sk2; 173 kuid_t uid = sock_i_uid(sk); 174 int res = 0; 175 176 spin_lock(&hslot2->lock); 177 udp_portaddr_for_each_entry(sk2, &hslot2->head) { 178 if (net_eq(sock_net(sk2), net) && 179 sk2 != sk && 180 (udp_sk(sk2)->udp_port_hash == num) && 181 (!sk2->sk_reuse || !sk->sk_reuse) && 182 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 183 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 184 inet_rcv_saddr_equal(sk, sk2, true)) { 185 if (sk2->sk_reuseport && sk->sk_reuseport && 186 !rcu_access_pointer(sk->sk_reuseport_cb) && 187 uid_eq(uid, sock_i_uid(sk2))) { 188 res = 0; 189 } else { 190 res = 1; 191 } 192 break; 193 } 194 } 195 spin_unlock(&hslot2->lock); 196 return res; 197 } 198 199 static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot) 200 { 201 struct net *net = sock_net(sk); 202 kuid_t uid = sock_i_uid(sk); 203 struct sock *sk2; 204 205 sk_for_each(sk2, &hslot->head) { 206 if (net_eq(sock_net(sk2), net) && 207 sk2 != sk && 208 sk2->sk_family == sk->sk_family && 209 ipv6_only_sock(sk2) == ipv6_only_sock(sk) && 210 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) && 211 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 212 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && 213 inet_rcv_saddr_equal(sk, sk2, false)) { 214 return reuseport_add_sock(sk, sk2, 215 inet_rcv_saddr_any(sk)); 216 } 217 } 218 219 return reuseport_alloc(sk, inet_rcv_saddr_any(sk)); 220 } 221 222 /** 223 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 224 * 225 * @sk: socket struct in question 226 * @snum: port number to look up 227 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 228 * with NULL address 229 */ 230 int udp_lib_get_port(struct sock *sk, unsigned short snum, 231 unsigned int hash2_nulladdr) 232 { 233 struct udp_hslot *hslot, *hslot2; 234 struct udp_table *udptable = sk->sk_prot->h.udp_table; 235 int error = 1; 236 struct net *net = sock_net(sk); 237 238 if (!snum) { 239 int low, high, remaining; 240 unsigned int rand; 241 unsigned short first, last; 242 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 243 244 inet_get_local_port_range(net, &low, &high); 245 remaining = (high - low) + 1; 246 247 rand = prandom_u32(); 248 first = reciprocal_scale(rand, remaining) + low; 249 /* 250 * force rand to be an odd multiple of UDP_HTABLE_SIZE 251 */ 252 rand = (rand | 1) * (udptable->mask + 1); 253 last = first + udptable->mask + 1; 254 do { 255 hslot = udp_hashslot(udptable, net, first); 256 bitmap_zero(bitmap, PORTS_PER_CHAIN); 257 spin_lock_bh(&hslot->lock); 258 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 259 udptable->log); 260 261 snum = first; 262 /* 263 * Iterate on all possible values of snum for this hash. 264 * Using steps of an odd multiple of UDP_HTABLE_SIZE 265 * give us randomization and full range coverage. 266 */ 267 do { 268 if (low <= snum && snum <= high && 269 !test_bit(snum >> udptable->log, bitmap) && 270 !inet_is_local_reserved_port(net, snum)) 271 goto found; 272 snum += rand; 273 } while (snum != first); 274 spin_unlock_bh(&hslot->lock); 275 cond_resched(); 276 } while (++first != last); 277 goto fail; 278 } else { 279 hslot = udp_hashslot(udptable, net, snum); 280 spin_lock_bh(&hslot->lock); 281 if (hslot->count > 10) { 282 int exist; 283 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 284 285 slot2 &= udptable->mask; 286 hash2_nulladdr &= udptable->mask; 287 288 hslot2 = udp_hashslot2(udptable, slot2); 289 if (hslot->count < hslot2->count) 290 goto scan_primary_hash; 291 292 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk); 293 if (!exist && (hash2_nulladdr != slot2)) { 294 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 295 exist = udp_lib_lport_inuse2(net, snum, hslot2, 296 sk); 297 } 298 if (exist) 299 goto fail_unlock; 300 else 301 goto found; 302 } 303 scan_primary_hash: 304 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0)) 305 goto fail_unlock; 306 } 307 found: 308 inet_sk(sk)->inet_num = snum; 309 udp_sk(sk)->udp_port_hash = snum; 310 udp_sk(sk)->udp_portaddr_hash ^= snum; 311 if (sk_unhashed(sk)) { 312 if (sk->sk_reuseport && 313 udp_reuseport_add_sock(sk, hslot)) { 314 inet_sk(sk)->inet_num = 0; 315 udp_sk(sk)->udp_port_hash = 0; 316 udp_sk(sk)->udp_portaddr_hash ^= snum; 317 goto fail_unlock; 318 } 319 320 sk_add_node_rcu(sk, &hslot->head); 321 hslot->count++; 322 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 323 324 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 325 spin_lock(&hslot2->lock); 326 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 327 sk->sk_family == AF_INET6) 328 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node, 329 &hslot2->head); 330 else 331 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 332 &hslot2->head); 333 hslot2->count++; 334 spin_unlock(&hslot2->lock); 335 } 336 sock_set_flag(sk, SOCK_RCU_FREE); 337 error = 0; 338 fail_unlock: 339 spin_unlock_bh(&hslot->lock); 340 fail: 341 return error; 342 } 343 EXPORT_SYMBOL(udp_lib_get_port); 344 345 int udp_v4_get_port(struct sock *sk, unsigned short snum) 346 { 347 unsigned int hash2_nulladdr = 348 ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 349 unsigned int hash2_partial = 350 ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 351 352 /* precompute partial secondary hash */ 353 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 354 return udp_lib_get_port(sk, snum, hash2_nulladdr); 355 } 356 357 static int compute_score(struct sock *sk, struct net *net, 358 __be32 saddr, __be16 sport, 359 __be32 daddr, unsigned short hnum, 360 int dif, int sdif) 361 { 362 int score; 363 struct inet_sock *inet; 364 bool dev_match; 365 366 if (!net_eq(sock_net(sk), net) || 367 udp_sk(sk)->udp_port_hash != hnum || 368 ipv6_only_sock(sk)) 369 return -1; 370 371 if (sk->sk_rcv_saddr != daddr) 372 return -1; 373 374 score = (sk->sk_family == PF_INET) ? 2 : 1; 375 376 inet = inet_sk(sk); 377 if (inet->inet_daddr) { 378 if (inet->inet_daddr != saddr) 379 return -1; 380 score += 4; 381 } 382 383 if (inet->inet_dport) { 384 if (inet->inet_dport != sport) 385 return -1; 386 score += 4; 387 } 388 389 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, 390 dif, sdif); 391 if (!dev_match) 392 return -1; 393 score += 4; 394 395 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) 396 score++; 397 return score; 398 } 399 400 static u32 udp_ehashfn(const struct net *net, const __be32 laddr, 401 const __u16 lport, const __be32 faddr, 402 const __be16 fport) 403 { 404 static u32 udp_ehash_secret __read_mostly; 405 406 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); 407 408 return __inet_ehashfn(laddr, lport, faddr, fport, 409 udp_ehash_secret + net_hash_mix(net)); 410 } 411 412 static struct sock *lookup_reuseport(struct net *net, struct sock *sk, 413 struct sk_buff *skb, 414 __be32 saddr, __be16 sport, 415 __be32 daddr, unsigned short hnum) 416 { 417 struct sock *reuse_sk = NULL; 418 u32 hash; 419 420 if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) { 421 hash = udp_ehashfn(net, daddr, hnum, saddr, sport); 422 reuse_sk = reuseport_select_sock(sk, hash, skb, 423 sizeof(struct udphdr)); 424 } 425 return reuse_sk; 426 } 427 428 /* called with rcu_read_lock() */ 429 static struct sock *udp4_lib_lookup2(struct net *net, 430 __be32 saddr, __be16 sport, 431 __be32 daddr, unsigned int hnum, 432 int dif, int sdif, 433 struct udp_hslot *hslot2, 434 struct sk_buff *skb) 435 { 436 struct sock *sk, *result; 437 int score, badness; 438 439 result = NULL; 440 badness = 0; 441 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 442 score = compute_score(sk, net, saddr, sport, 443 daddr, hnum, dif, sdif); 444 if (score > badness) { 445 result = lookup_reuseport(net, sk, skb, 446 saddr, sport, daddr, hnum); 447 /* Fall back to scoring if group has connections */ 448 if (result && !reuseport_has_conns(sk, false)) 449 return result; 450 451 result = result ? : sk; 452 badness = score; 453 } 454 } 455 return result; 456 } 457 458 static struct sock *udp4_lookup_run_bpf(struct net *net, 459 struct udp_table *udptable, 460 struct sk_buff *skb, 461 __be32 saddr, __be16 sport, 462 __be32 daddr, u16 hnum) 463 { 464 struct sock *sk, *reuse_sk; 465 bool no_reuseport; 466 467 if (udptable != &udp_table) 468 return NULL; /* only UDP is supported */ 469 470 no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP, 471 saddr, sport, daddr, hnum, &sk); 472 if (no_reuseport || IS_ERR_OR_NULL(sk)) 473 return sk; 474 475 reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); 476 if (reuse_sk) 477 sk = reuse_sk; 478 return sk; 479 } 480 481 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 482 * harder than this. -DaveM 483 */ 484 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 485 __be16 sport, __be32 daddr, __be16 dport, int dif, 486 int sdif, struct udp_table *udptable, struct sk_buff *skb) 487 { 488 unsigned short hnum = ntohs(dport); 489 unsigned int hash2, slot2; 490 struct udp_hslot *hslot2; 491 struct sock *result, *sk; 492 493 hash2 = ipv4_portaddr_hash(net, daddr, hnum); 494 slot2 = hash2 & udptable->mask; 495 hslot2 = &udptable->hash2[slot2]; 496 497 /* Lookup connected or non-wildcard socket */ 498 result = udp4_lib_lookup2(net, saddr, sport, 499 daddr, hnum, dif, sdif, 500 hslot2, skb); 501 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED) 502 goto done; 503 504 /* Lookup redirect from BPF */ 505 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { 506 sk = udp4_lookup_run_bpf(net, udptable, skb, 507 saddr, sport, daddr, hnum); 508 if (sk) { 509 result = sk; 510 goto done; 511 } 512 } 513 514 /* Got non-wildcard socket or error on first lookup */ 515 if (result) 516 goto done; 517 518 /* Lookup wildcard sockets */ 519 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 520 slot2 = hash2 & udptable->mask; 521 hslot2 = &udptable->hash2[slot2]; 522 523 result = udp4_lib_lookup2(net, saddr, sport, 524 htonl(INADDR_ANY), hnum, dif, sdif, 525 hslot2, skb); 526 done: 527 if (IS_ERR(result)) 528 return NULL; 529 return result; 530 } 531 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 532 533 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 534 __be16 sport, __be16 dport, 535 struct udp_table *udptable) 536 { 537 const struct iphdr *iph = ip_hdr(skb); 538 539 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 540 iph->daddr, dport, inet_iif(skb), 541 inet_sdif(skb), udptable, skb); 542 } 543 544 struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb, 545 __be16 sport, __be16 dport) 546 { 547 const struct iphdr *iph = ip_hdr(skb); 548 549 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 550 iph->daddr, dport, inet_iif(skb), 551 inet_sdif(skb), &udp_table, NULL); 552 } 553 554 /* Must be called under rcu_read_lock(). 555 * Does increment socket refcount. 556 */ 557 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4) 558 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 559 __be32 daddr, __be16 dport, int dif) 560 { 561 struct sock *sk; 562 563 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport, 564 dif, 0, &udp_table, NULL); 565 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) 566 sk = NULL; 567 return sk; 568 } 569 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 570 #endif 571 572 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, 573 __be16 loc_port, __be32 loc_addr, 574 __be16 rmt_port, __be32 rmt_addr, 575 int dif, int sdif, unsigned short hnum) 576 { 577 struct inet_sock *inet = inet_sk(sk); 578 579 if (!net_eq(sock_net(sk), net) || 580 udp_sk(sk)->udp_port_hash != hnum || 581 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 582 (inet->inet_dport != rmt_port && inet->inet_dport) || 583 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) || 584 ipv6_only_sock(sk) || 585 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif)) 586 return false; 587 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif)) 588 return false; 589 return true; 590 } 591 592 DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key); 593 void udp_encap_enable(void) 594 { 595 static_branch_inc(&udp_encap_needed_key); 596 } 597 EXPORT_SYMBOL(udp_encap_enable); 598 599 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go 600 * through error handlers in encapsulations looking for a match. 601 */ 602 static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info) 603 { 604 int i; 605 606 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { 607 int (*handler)(struct sk_buff *skb, u32 info); 608 const struct ip_tunnel_encap_ops *encap; 609 610 encap = rcu_dereference(iptun_encaps[i]); 611 if (!encap) 612 continue; 613 handler = encap->err_handler; 614 if (handler && !handler(skb, info)) 615 return 0; 616 } 617 618 return -ENOENT; 619 } 620 621 /* Try to match ICMP errors to UDP tunnels by looking up a socket without 622 * reversing source and destination port: this will match tunnels that force the 623 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that 624 * lwtunnels might actually break this assumption by being configured with 625 * different destination ports on endpoints, in this case we won't be able to 626 * trace ICMP messages back to them. 627 * 628 * If this doesn't match any socket, probe tunnels with arbitrary destination 629 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port 630 * we've sent packets to won't necessarily match the local destination port. 631 * 632 * Then ask the tunnel implementation to match the error against a valid 633 * association. 634 * 635 * Return an error if we can't find a match, the socket if we need further 636 * processing, zero otherwise. 637 */ 638 static struct sock *__udp4_lib_err_encap(struct net *net, 639 const struct iphdr *iph, 640 struct udphdr *uh, 641 struct udp_table *udptable, 642 struct sk_buff *skb, u32 info) 643 { 644 int network_offset, transport_offset; 645 struct sock *sk; 646 647 network_offset = skb_network_offset(skb); 648 transport_offset = skb_transport_offset(skb); 649 650 /* Network header needs to point to the outer IPv4 header inside ICMP */ 651 skb_reset_network_header(skb); 652 653 /* Transport header needs to point to the UDP header */ 654 skb_set_transport_header(skb, iph->ihl << 2); 655 656 sk = __udp4_lib_lookup(net, iph->daddr, uh->source, 657 iph->saddr, uh->dest, skb->dev->ifindex, 0, 658 udptable, NULL); 659 if (sk) { 660 int (*lookup)(struct sock *sk, struct sk_buff *skb); 661 struct udp_sock *up = udp_sk(sk); 662 663 lookup = READ_ONCE(up->encap_err_lookup); 664 if (!lookup || lookup(sk, skb)) 665 sk = NULL; 666 } 667 668 if (!sk) 669 sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info)); 670 671 skb_set_transport_header(skb, transport_offset); 672 skb_set_network_header(skb, network_offset); 673 674 return sk; 675 } 676 677 /* 678 * This routine is called by the ICMP module when it gets some 679 * sort of error condition. If err < 0 then the socket should 680 * be closed and the error returned to the user. If err > 0 681 * it's just the icmp type << 8 | icmp code. 682 * Header points to the ip header of the error packet. We move 683 * on past this. Then (as it used to claim before adjustment) 684 * header points to the first 8 bytes of the udp header. We need 685 * to find the appropriate port. 686 */ 687 688 int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 689 { 690 struct inet_sock *inet; 691 const struct iphdr *iph = (const struct iphdr *)skb->data; 692 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 693 const int type = icmp_hdr(skb)->type; 694 const int code = icmp_hdr(skb)->code; 695 bool tunnel = false; 696 struct sock *sk; 697 int harderr; 698 int err; 699 struct net *net = dev_net(skb->dev); 700 701 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 702 iph->saddr, uh->source, skb->dev->ifindex, 703 inet_sdif(skb), udptable, NULL); 704 if (!sk || udp_sk(sk)->encap_type) { 705 /* No socket for error: try tunnels before discarding */ 706 sk = ERR_PTR(-ENOENT); 707 if (static_branch_unlikely(&udp_encap_needed_key)) { 708 sk = __udp4_lib_err_encap(net, iph, uh, udptable, skb, 709 info); 710 if (!sk) 711 return 0; 712 } 713 714 if (IS_ERR(sk)) { 715 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); 716 return PTR_ERR(sk); 717 } 718 719 tunnel = true; 720 } 721 722 err = 0; 723 harderr = 0; 724 inet = inet_sk(sk); 725 726 switch (type) { 727 default: 728 case ICMP_TIME_EXCEEDED: 729 err = EHOSTUNREACH; 730 break; 731 case ICMP_SOURCE_QUENCH: 732 goto out; 733 case ICMP_PARAMETERPROB: 734 err = EPROTO; 735 harderr = 1; 736 break; 737 case ICMP_DEST_UNREACH: 738 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 739 ipv4_sk_update_pmtu(skb, sk, info); 740 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 741 err = EMSGSIZE; 742 harderr = 1; 743 break; 744 } 745 goto out; 746 } 747 err = EHOSTUNREACH; 748 if (code <= NR_ICMP_UNREACH) { 749 harderr = icmp_err_convert[code].fatal; 750 err = icmp_err_convert[code].errno; 751 } 752 break; 753 case ICMP_REDIRECT: 754 ipv4_sk_redirect(skb, sk); 755 goto out; 756 } 757 758 /* 759 * RFC1122: OK. Passes ICMP errors back to application, as per 760 * 4.1.3.3. 761 */ 762 if (tunnel) { 763 /* ...not for tunnels though: we don't have a sending socket */ 764 goto out; 765 } 766 if (!inet->recverr) { 767 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 768 goto out; 769 } else 770 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 771 772 sk->sk_err = err; 773 sk->sk_error_report(sk); 774 out: 775 return 0; 776 } 777 778 int udp_err(struct sk_buff *skb, u32 info) 779 { 780 return __udp4_lib_err(skb, info, &udp_table); 781 } 782 783 /* 784 * Throw away all pending data and cancel the corking. Socket is locked. 785 */ 786 void udp_flush_pending_frames(struct sock *sk) 787 { 788 struct udp_sock *up = udp_sk(sk); 789 790 if (up->pending) { 791 up->len = 0; 792 up->pending = 0; 793 ip_flush_pending_frames(sk); 794 } 795 } 796 EXPORT_SYMBOL(udp_flush_pending_frames); 797 798 /** 799 * udp4_hwcsum - handle outgoing HW checksumming 800 * @skb: sk_buff containing the filled-in UDP header 801 * (checksum field must be zeroed out) 802 * @src: source IP address 803 * @dst: destination IP address 804 */ 805 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 806 { 807 struct udphdr *uh = udp_hdr(skb); 808 int offset = skb_transport_offset(skb); 809 int len = skb->len - offset; 810 int hlen = len; 811 __wsum csum = 0; 812 813 if (!skb_has_frag_list(skb)) { 814 /* 815 * Only one fragment on the socket. 816 */ 817 skb->csum_start = skb_transport_header(skb) - skb->head; 818 skb->csum_offset = offsetof(struct udphdr, check); 819 uh->check = ~csum_tcpudp_magic(src, dst, len, 820 IPPROTO_UDP, 0); 821 } else { 822 struct sk_buff *frags; 823 824 /* 825 * HW-checksum won't work as there are two or more 826 * fragments on the socket so that all csums of sk_buffs 827 * should be together 828 */ 829 skb_walk_frags(skb, frags) { 830 csum = csum_add(csum, frags->csum); 831 hlen -= frags->len; 832 } 833 834 csum = skb_checksum(skb, offset, hlen, csum); 835 skb->ip_summed = CHECKSUM_NONE; 836 837 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 838 if (uh->check == 0) 839 uh->check = CSUM_MANGLED_0; 840 } 841 } 842 EXPORT_SYMBOL_GPL(udp4_hwcsum); 843 844 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended 845 * for the simple case like when setting the checksum for a UDP tunnel. 846 */ 847 void udp_set_csum(bool nocheck, struct sk_buff *skb, 848 __be32 saddr, __be32 daddr, int len) 849 { 850 struct udphdr *uh = udp_hdr(skb); 851 852 if (nocheck) { 853 uh->check = 0; 854 } else if (skb_is_gso(skb)) { 855 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 856 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { 857 uh->check = 0; 858 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb)); 859 if (uh->check == 0) 860 uh->check = CSUM_MANGLED_0; 861 } else { 862 skb->ip_summed = CHECKSUM_PARTIAL; 863 skb->csum_start = skb_transport_header(skb) - skb->head; 864 skb->csum_offset = offsetof(struct udphdr, check); 865 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 866 } 867 } 868 EXPORT_SYMBOL(udp_set_csum); 869 870 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4, 871 struct inet_cork *cork) 872 { 873 struct sock *sk = skb->sk; 874 struct inet_sock *inet = inet_sk(sk); 875 struct udphdr *uh; 876 int err; 877 int is_udplite = IS_UDPLITE(sk); 878 int offset = skb_transport_offset(skb); 879 int len = skb->len - offset; 880 int datalen = len - sizeof(*uh); 881 __wsum csum = 0; 882 883 /* 884 * Create a UDP header 885 */ 886 uh = udp_hdr(skb); 887 uh->source = inet->inet_sport; 888 uh->dest = fl4->fl4_dport; 889 uh->len = htons(len); 890 uh->check = 0; 891 892 if (cork->gso_size) { 893 const int hlen = skb_network_header_len(skb) + 894 sizeof(struct udphdr); 895 896 if (hlen + cork->gso_size > cork->fragsize) { 897 kfree_skb(skb); 898 return -EINVAL; 899 } 900 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) { 901 kfree_skb(skb); 902 return -EINVAL; 903 } 904 if (sk->sk_no_check_tx) { 905 kfree_skb(skb); 906 return -EINVAL; 907 } 908 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || 909 dst_xfrm(skb_dst(skb))) { 910 kfree_skb(skb); 911 return -EIO; 912 } 913 914 if (datalen > cork->gso_size) { 915 skb_shinfo(skb)->gso_size = cork->gso_size; 916 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; 917 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, 918 cork->gso_size); 919 } 920 goto csum_partial; 921 } 922 923 if (is_udplite) /* UDP-Lite */ 924 csum = udplite_csum(skb); 925 926 else if (sk->sk_no_check_tx) { /* UDP csum off */ 927 928 skb->ip_summed = CHECKSUM_NONE; 929 goto send; 930 931 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 932 csum_partial: 933 934 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 935 goto send; 936 937 } else 938 csum = udp_csum(skb); 939 940 /* add protocol-dependent pseudo-header */ 941 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 942 sk->sk_protocol, csum); 943 if (uh->check == 0) 944 uh->check = CSUM_MANGLED_0; 945 946 send: 947 err = ip_send_skb(sock_net(sk), skb); 948 if (err) { 949 if (err == -ENOBUFS && !inet->recverr) { 950 UDP_INC_STATS(sock_net(sk), 951 UDP_MIB_SNDBUFERRORS, is_udplite); 952 err = 0; 953 } 954 } else 955 UDP_INC_STATS(sock_net(sk), 956 UDP_MIB_OUTDATAGRAMS, is_udplite); 957 return err; 958 } 959 960 /* 961 * Push out all pending data as one UDP datagram. Socket is locked. 962 */ 963 int udp_push_pending_frames(struct sock *sk) 964 { 965 struct udp_sock *up = udp_sk(sk); 966 struct inet_sock *inet = inet_sk(sk); 967 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 968 struct sk_buff *skb; 969 int err = 0; 970 971 skb = ip_finish_skb(sk, fl4); 972 if (!skb) 973 goto out; 974 975 err = udp_send_skb(skb, fl4, &inet->cork.base); 976 977 out: 978 up->len = 0; 979 up->pending = 0; 980 return err; 981 } 982 EXPORT_SYMBOL(udp_push_pending_frames); 983 984 static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size) 985 { 986 switch (cmsg->cmsg_type) { 987 case UDP_SEGMENT: 988 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16))) 989 return -EINVAL; 990 *gso_size = *(__u16 *)CMSG_DATA(cmsg); 991 return 0; 992 default: 993 return -EINVAL; 994 } 995 } 996 997 int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size) 998 { 999 struct cmsghdr *cmsg; 1000 bool need_ip = false; 1001 int err; 1002 1003 for_each_cmsghdr(cmsg, msg) { 1004 if (!CMSG_OK(msg, cmsg)) 1005 return -EINVAL; 1006 1007 if (cmsg->cmsg_level != SOL_UDP) { 1008 need_ip = true; 1009 continue; 1010 } 1011 1012 err = __udp_cmsg_send(cmsg, gso_size); 1013 if (err) 1014 return err; 1015 } 1016 1017 return need_ip; 1018 } 1019 EXPORT_SYMBOL_GPL(udp_cmsg_send); 1020 1021 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 1022 { 1023 struct inet_sock *inet = inet_sk(sk); 1024 struct udp_sock *up = udp_sk(sk); 1025 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 1026 struct flowi4 fl4_stack; 1027 struct flowi4 *fl4; 1028 int ulen = len; 1029 struct ipcm_cookie ipc; 1030 struct rtable *rt = NULL; 1031 int free = 0; 1032 int connected = 0; 1033 __be32 daddr, faddr, saddr; 1034 __be16 dport; 1035 u8 tos; 1036 int err, is_udplite = IS_UDPLITE(sk); 1037 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 1038 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 1039 struct sk_buff *skb; 1040 struct ip_options_data opt_copy; 1041 1042 if (len > 0xFFFF) 1043 return -EMSGSIZE; 1044 1045 /* 1046 * Check the flags. 1047 */ 1048 1049 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 1050 return -EOPNOTSUPP; 1051 1052 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 1053 1054 fl4 = &inet->cork.fl.u.ip4; 1055 if (up->pending) { 1056 /* 1057 * There are pending frames. 1058 * The socket lock must be held while it's corked. 1059 */ 1060 lock_sock(sk); 1061 if (likely(up->pending)) { 1062 if (unlikely(up->pending != AF_INET)) { 1063 release_sock(sk); 1064 return -EINVAL; 1065 } 1066 goto do_append_data; 1067 } 1068 release_sock(sk); 1069 } 1070 ulen += sizeof(struct udphdr); 1071 1072 /* 1073 * Get and verify the address. 1074 */ 1075 if (usin) { 1076 if (msg->msg_namelen < sizeof(*usin)) 1077 return -EINVAL; 1078 if (usin->sin_family != AF_INET) { 1079 if (usin->sin_family != AF_UNSPEC) 1080 return -EAFNOSUPPORT; 1081 } 1082 1083 daddr = usin->sin_addr.s_addr; 1084 dport = usin->sin_port; 1085 if (dport == 0) 1086 return -EINVAL; 1087 } else { 1088 if (sk->sk_state != TCP_ESTABLISHED) 1089 return -EDESTADDRREQ; 1090 daddr = inet->inet_daddr; 1091 dport = inet->inet_dport; 1092 /* Open fast path for connected socket. 1093 Route will not be used, if at least one option is set. 1094 */ 1095 connected = 1; 1096 } 1097 1098 ipcm_init_sk(&ipc, inet); 1099 ipc.gso_size = up->gso_size; 1100 1101 if (msg->msg_controllen) { 1102 err = udp_cmsg_send(sk, msg, &ipc.gso_size); 1103 if (err > 0) 1104 err = ip_cmsg_send(sk, msg, &ipc, 1105 sk->sk_family == AF_INET6); 1106 if (unlikely(err < 0)) { 1107 kfree(ipc.opt); 1108 return err; 1109 } 1110 if (ipc.opt) 1111 free = 1; 1112 connected = 0; 1113 } 1114 if (!ipc.opt) { 1115 struct ip_options_rcu *inet_opt; 1116 1117 rcu_read_lock(); 1118 inet_opt = rcu_dereference(inet->inet_opt); 1119 if (inet_opt) { 1120 memcpy(&opt_copy, inet_opt, 1121 sizeof(*inet_opt) + inet_opt->opt.optlen); 1122 ipc.opt = &opt_copy.opt; 1123 } 1124 rcu_read_unlock(); 1125 } 1126 1127 if (cgroup_bpf_enabled && !connected) { 1128 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, 1129 (struct sockaddr *)usin, &ipc.addr); 1130 if (err) 1131 goto out_free; 1132 if (usin) { 1133 if (usin->sin_port == 0) { 1134 /* BPF program set invalid port. Reject it. */ 1135 err = -EINVAL; 1136 goto out_free; 1137 } 1138 daddr = usin->sin_addr.s_addr; 1139 dport = usin->sin_port; 1140 } 1141 } 1142 1143 saddr = ipc.addr; 1144 ipc.addr = faddr = daddr; 1145 1146 if (ipc.opt && ipc.opt->opt.srr) { 1147 if (!daddr) { 1148 err = -EINVAL; 1149 goto out_free; 1150 } 1151 faddr = ipc.opt->opt.faddr; 1152 connected = 0; 1153 } 1154 tos = get_rttos(&ipc, inet); 1155 if (sock_flag(sk, SOCK_LOCALROUTE) || 1156 (msg->msg_flags & MSG_DONTROUTE) || 1157 (ipc.opt && ipc.opt->opt.is_strictroute)) { 1158 tos |= RTO_ONLINK; 1159 connected = 0; 1160 } 1161 1162 if (ipv4_is_multicast(daddr)) { 1163 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 1164 ipc.oif = inet->mc_index; 1165 if (!saddr) 1166 saddr = inet->mc_addr; 1167 connected = 0; 1168 } else if (!ipc.oif) { 1169 ipc.oif = inet->uc_index; 1170 } else if (ipv4_is_lbcast(daddr) && inet->uc_index) { 1171 /* oif is set, packet is to local broadcast and 1172 * uc_index is set. oif is most likely set 1173 * by sk_bound_dev_if. If uc_index != oif check if the 1174 * oif is an L3 master and uc_index is an L3 slave. 1175 * If so, we want to allow the send using the uc_index. 1176 */ 1177 if (ipc.oif != inet->uc_index && 1178 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk), 1179 inet->uc_index)) { 1180 ipc.oif = inet->uc_index; 1181 } 1182 } 1183 1184 if (connected) 1185 rt = (struct rtable *)sk_dst_check(sk, 0); 1186 1187 if (!rt) { 1188 struct net *net = sock_net(sk); 1189 __u8 flow_flags = inet_sk_flowi_flags(sk); 1190 1191 fl4 = &fl4_stack; 1192 1193 flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos, 1194 RT_SCOPE_UNIVERSE, sk->sk_protocol, 1195 flow_flags, 1196 faddr, saddr, dport, inet->inet_sport, 1197 sk->sk_uid); 1198 1199 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 1200 rt = ip_route_output_flow(net, fl4, sk); 1201 if (IS_ERR(rt)) { 1202 err = PTR_ERR(rt); 1203 rt = NULL; 1204 if (err == -ENETUNREACH) 1205 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 1206 goto out; 1207 } 1208 1209 err = -EACCES; 1210 if ((rt->rt_flags & RTCF_BROADCAST) && 1211 !sock_flag(sk, SOCK_BROADCAST)) 1212 goto out; 1213 if (connected) 1214 sk_dst_set(sk, dst_clone(&rt->dst)); 1215 } 1216 1217 if (msg->msg_flags&MSG_CONFIRM) 1218 goto do_confirm; 1219 back_from_confirm: 1220 1221 saddr = fl4->saddr; 1222 if (!ipc.addr) 1223 daddr = ipc.addr = fl4->daddr; 1224 1225 /* Lockless fast path for the non-corking case. */ 1226 if (!corkreq) { 1227 struct inet_cork cork; 1228 1229 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen, 1230 sizeof(struct udphdr), &ipc, &rt, 1231 &cork, msg->msg_flags); 1232 err = PTR_ERR(skb); 1233 if (!IS_ERR_OR_NULL(skb)) 1234 err = udp_send_skb(skb, fl4, &cork); 1235 goto out; 1236 } 1237 1238 lock_sock(sk); 1239 if (unlikely(up->pending)) { 1240 /* The socket is already corked while preparing it. */ 1241 /* ... which is an evident application bug. --ANK */ 1242 release_sock(sk); 1243 1244 net_dbg_ratelimited("socket already corked\n"); 1245 err = -EINVAL; 1246 goto out; 1247 } 1248 /* 1249 * Now cork the socket to pend data. 1250 */ 1251 fl4 = &inet->cork.fl.u.ip4; 1252 fl4->daddr = daddr; 1253 fl4->saddr = saddr; 1254 fl4->fl4_dport = dport; 1255 fl4->fl4_sport = inet->inet_sport; 1256 up->pending = AF_INET; 1257 1258 do_append_data: 1259 up->len += ulen; 1260 err = ip_append_data(sk, fl4, getfrag, msg, ulen, 1261 sizeof(struct udphdr), &ipc, &rt, 1262 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1263 if (err) 1264 udp_flush_pending_frames(sk); 1265 else if (!corkreq) 1266 err = udp_push_pending_frames(sk); 1267 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1268 up->pending = 0; 1269 release_sock(sk); 1270 1271 out: 1272 ip_rt_put(rt); 1273 out_free: 1274 if (free) 1275 kfree(ipc.opt); 1276 if (!err) 1277 return len; 1278 /* 1279 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1280 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1281 * we don't have a good statistic (IpOutDiscards but it can be too many 1282 * things). We could add another new stat but at least for now that 1283 * seems like overkill. 1284 */ 1285 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1286 UDP_INC_STATS(sock_net(sk), 1287 UDP_MIB_SNDBUFERRORS, is_udplite); 1288 } 1289 return err; 1290 1291 do_confirm: 1292 if (msg->msg_flags & MSG_PROBE) 1293 dst_confirm_neigh(&rt->dst, &fl4->daddr); 1294 if (!(msg->msg_flags&MSG_PROBE) || len) 1295 goto back_from_confirm; 1296 err = 0; 1297 goto out; 1298 } 1299 EXPORT_SYMBOL(udp_sendmsg); 1300 1301 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1302 size_t size, int flags) 1303 { 1304 struct inet_sock *inet = inet_sk(sk); 1305 struct udp_sock *up = udp_sk(sk); 1306 int ret; 1307 1308 if (flags & MSG_SENDPAGE_NOTLAST) 1309 flags |= MSG_MORE; 1310 1311 if (!up->pending) { 1312 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1313 1314 /* Call udp_sendmsg to specify destination address which 1315 * sendpage interface can't pass. 1316 * This will succeed only when the socket is connected. 1317 */ 1318 ret = udp_sendmsg(sk, &msg, 0); 1319 if (ret < 0) 1320 return ret; 1321 } 1322 1323 lock_sock(sk); 1324 1325 if (unlikely(!up->pending)) { 1326 release_sock(sk); 1327 1328 net_dbg_ratelimited("cork failed\n"); 1329 return -EINVAL; 1330 } 1331 1332 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1333 page, offset, size, flags); 1334 if (ret == -EOPNOTSUPP) { 1335 release_sock(sk); 1336 return sock_no_sendpage(sk->sk_socket, page, offset, 1337 size, flags); 1338 } 1339 if (ret < 0) { 1340 udp_flush_pending_frames(sk); 1341 goto out; 1342 } 1343 1344 up->len += size; 1345 if (!(up->corkflag || (flags&MSG_MORE))) 1346 ret = udp_push_pending_frames(sk); 1347 if (!ret) 1348 ret = size; 1349 out: 1350 release_sock(sk); 1351 return ret; 1352 } 1353 1354 #define UDP_SKB_IS_STATELESS 0x80000000 1355 1356 /* all head states (dst, sk, nf conntrack) except skb extensions are 1357 * cleared by udp_rcv(). 1358 * 1359 * We need to preserve secpath, if present, to eventually process 1360 * IP_CMSG_PASSSEC at recvmsg() time. 1361 * 1362 * Other extensions can be cleared. 1363 */ 1364 static bool udp_try_make_stateless(struct sk_buff *skb) 1365 { 1366 if (!skb_has_extensions(skb)) 1367 return true; 1368 1369 if (!secpath_exists(skb)) { 1370 skb_ext_reset(skb); 1371 return true; 1372 } 1373 1374 return false; 1375 } 1376 1377 static void udp_set_dev_scratch(struct sk_buff *skb) 1378 { 1379 struct udp_dev_scratch *scratch = udp_skb_scratch(skb); 1380 1381 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long)); 1382 scratch->_tsize_state = skb->truesize; 1383 #if BITS_PER_LONG == 64 1384 scratch->len = skb->len; 1385 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb); 1386 scratch->is_linear = !skb_is_nonlinear(skb); 1387 #endif 1388 if (udp_try_make_stateless(skb)) 1389 scratch->_tsize_state |= UDP_SKB_IS_STATELESS; 1390 } 1391 1392 static void udp_skb_csum_unnecessary_set(struct sk_buff *skb) 1393 { 1394 /* We come here after udp_lib_checksum_complete() returned 0. 1395 * This means that __skb_checksum_complete() might have 1396 * set skb->csum_valid to 1. 1397 * On 64bit platforms, we can set csum_unnecessary 1398 * to true, but only if the skb is not shared. 1399 */ 1400 #if BITS_PER_LONG == 64 1401 if (!skb_shared(skb)) 1402 udp_skb_scratch(skb)->csum_unnecessary = true; 1403 #endif 1404 } 1405 1406 static int udp_skb_truesize(struct sk_buff *skb) 1407 { 1408 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS; 1409 } 1410 1411 static bool udp_skb_has_head_state(struct sk_buff *skb) 1412 { 1413 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS); 1414 } 1415 1416 /* fully reclaim rmem/fwd memory allocated for skb */ 1417 static void udp_rmem_release(struct sock *sk, int size, int partial, 1418 bool rx_queue_lock_held) 1419 { 1420 struct udp_sock *up = udp_sk(sk); 1421 struct sk_buff_head *sk_queue; 1422 int amt; 1423 1424 if (likely(partial)) { 1425 up->forward_deficit += size; 1426 size = up->forward_deficit; 1427 if (size < (sk->sk_rcvbuf >> 2) && 1428 !skb_queue_empty(&up->reader_queue)) 1429 return; 1430 } else { 1431 size += up->forward_deficit; 1432 } 1433 up->forward_deficit = 0; 1434 1435 /* acquire the sk_receive_queue for fwd allocated memory scheduling, 1436 * if the called don't held it already 1437 */ 1438 sk_queue = &sk->sk_receive_queue; 1439 if (!rx_queue_lock_held) 1440 spin_lock(&sk_queue->lock); 1441 1442 1443 sk->sk_forward_alloc += size; 1444 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1); 1445 sk->sk_forward_alloc -= amt; 1446 1447 if (amt) 1448 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT); 1449 1450 atomic_sub(size, &sk->sk_rmem_alloc); 1451 1452 /* this can save us from acquiring the rx queue lock on next receive */ 1453 skb_queue_splice_tail_init(sk_queue, &up->reader_queue); 1454 1455 if (!rx_queue_lock_held) 1456 spin_unlock(&sk_queue->lock); 1457 } 1458 1459 /* Note: called with reader_queue.lock held. 1460 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch 1461 * This avoids a cache line miss while receive_queue lock is held. 1462 * Look at __udp_enqueue_schedule_skb() to find where this copy is done. 1463 */ 1464 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb) 1465 { 1466 prefetch(&skb->data); 1467 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false); 1468 } 1469 EXPORT_SYMBOL(udp_skb_destructor); 1470 1471 /* as above, but the caller held the rx queue lock, too */ 1472 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb) 1473 { 1474 prefetch(&skb->data); 1475 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true); 1476 } 1477 1478 /* Idea of busylocks is to let producers grab an extra spinlock 1479 * to relieve pressure on the receive_queue spinlock shared by consumer. 1480 * Under flood, this means that only one producer can be in line 1481 * trying to acquire the receive_queue spinlock. 1482 * These busylock can be allocated on a per cpu manner, instead of a 1483 * per socket one (that would consume a cache line per socket) 1484 */ 1485 static int udp_busylocks_log __read_mostly; 1486 static spinlock_t *udp_busylocks __read_mostly; 1487 1488 static spinlock_t *busylock_acquire(void *ptr) 1489 { 1490 spinlock_t *busy; 1491 1492 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log); 1493 spin_lock(busy); 1494 return busy; 1495 } 1496 1497 static void busylock_release(spinlock_t *busy) 1498 { 1499 if (busy) 1500 spin_unlock(busy); 1501 } 1502 1503 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) 1504 { 1505 struct sk_buff_head *list = &sk->sk_receive_queue; 1506 int rmem, delta, amt, err = -ENOMEM; 1507 spinlock_t *busy = NULL; 1508 int size; 1509 1510 /* try to avoid the costly atomic add/sub pair when the receive 1511 * queue is full; always allow at least a packet 1512 */ 1513 rmem = atomic_read(&sk->sk_rmem_alloc); 1514 if (rmem > sk->sk_rcvbuf) 1515 goto drop; 1516 1517 /* Under mem pressure, it might be helpful to help udp_recvmsg() 1518 * having linear skbs : 1519 * - Reduce memory overhead and thus increase receive queue capacity 1520 * - Less cache line misses at copyout() time 1521 * - Less work at consume_skb() (less alien page frag freeing) 1522 */ 1523 if (rmem > (sk->sk_rcvbuf >> 1)) { 1524 skb_condense(skb); 1525 1526 busy = busylock_acquire(sk); 1527 } 1528 size = skb->truesize; 1529 udp_set_dev_scratch(skb); 1530 1531 /* we drop only if the receive buf is full and the receive 1532 * queue contains some other skb 1533 */ 1534 rmem = atomic_add_return(size, &sk->sk_rmem_alloc); 1535 if (rmem > (size + (unsigned int)sk->sk_rcvbuf)) 1536 goto uncharge_drop; 1537 1538 spin_lock(&list->lock); 1539 if (size >= sk->sk_forward_alloc) { 1540 amt = sk_mem_pages(size); 1541 delta = amt << SK_MEM_QUANTUM_SHIFT; 1542 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) { 1543 err = -ENOBUFS; 1544 spin_unlock(&list->lock); 1545 goto uncharge_drop; 1546 } 1547 1548 sk->sk_forward_alloc += delta; 1549 } 1550 1551 sk->sk_forward_alloc -= size; 1552 1553 /* no need to setup a destructor, we will explicitly release the 1554 * forward allocated memory on dequeue 1555 */ 1556 sock_skb_set_dropcount(sk, skb); 1557 1558 __skb_queue_tail(list, skb); 1559 spin_unlock(&list->lock); 1560 1561 if (!sock_flag(sk, SOCK_DEAD)) 1562 sk->sk_data_ready(sk); 1563 1564 busylock_release(busy); 1565 return 0; 1566 1567 uncharge_drop: 1568 atomic_sub(skb->truesize, &sk->sk_rmem_alloc); 1569 1570 drop: 1571 atomic_inc(&sk->sk_drops); 1572 busylock_release(busy); 1573 return err; 1574 } 1575 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb); 1576 1577 void udp_destruct_sock(struct sock *sk) 1578 { 1579 /* reclaim completely the forward allocated memory */ 1580 struct udp_sock *up = udp_sk(sk); 1581 unsigned int total = 0; 1582 struct sk_buff *skb; 1583 1584 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue); 1585 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) { 1586 total += skb->truesize; 1587 kfree_skb(skb); 1588 } 1589 udp_rmem_release(sk, total, 0, true); 1590 1591 inet_sock_destruct(sk); 1592 } 1593 EXPORT_SYMBOL_GPL(udp_destruct_sock); 1594 1595 int udp_init_sock(struct sock *sk) 1596 { 1597 skb_queue_head_init(&udp_sk(sk)->reader_queue); 1598 sk->sk_destruct = udp_destruct_sock; 1599 return 0; 1600 } 1601 EXPORT_SYMBOL_GPL(udp_init_sock); 1602 1603 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) 1604 { 1605 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) { 1606 bool slow = lock_sock_fast(sk); 1607 1608 sk_peek_offset_bwd(sk, len); 1609 unlock_sock_fast(sk, slow); 1610 } 1611 1612 if (!skb_unref(skb)) 1613 return; 1614 1615 /* In the more common cases we cleared the head states previously, 1616 * see __udp_queue_rcv_skb(). 1617 */ 1618 if (unlikely(udp_skb_has_head_state(skb))) 1619 skb_release_head_state(skb); 1620 __consume_stateless_skb(skb); 1621 } 1622 EXPORT_SYMBOL_GPL(skb_consume_udp); 1623 1624 static struct sk_buff *__first_packet_length(struct sock *sk, 1625 struct sk_buff_head *rcvq, 1626 int *total) 1627 { 1628 struct sk_buff *skb; 1629 1630 while ((skb = skb_peek(rcvq)) != NULL) { 1631 if (udp_lib_checksum_complete(skb)) { 1632 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, 1633 IS_UDPLITE(sk)); 1634 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, 1635 IS_UDPLITE(sk)); 1636 atomic_inc(&sk->sk_drops); 1637 __skb_unlink(skb, rcvq); 1638 *total += skb->truesize; 1639 kfree_skb(skb); 1640 } else { 1641 udp_skb_csum_unnecessary_set(skb); 1642 break; 1643 } 1644 } 1645 return skb; 1646 } 1647 1648 /** 1649 * first_packet_length - return length of first packet in receive queue 1650 * @sk: socket 1651 * 1652 * Drops all bad checksum frames, until a valid one is found. 1653 * Returns the length of found skb, or -1 if none is found. 1654 */ 1655 static int first_packet_length(struct sock *sk) 1656 { 1657 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue; 1658 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1659 struct sk_buff *skb; 1660 int total = 0; 1661 int res; 1662 1663 spin_lock_bh(&rcvq->lock); 1664 skb = __first_packet_length(sk, rcvq, &total); 1665 if (!skb && !skb_queue_empty_lockless(sk_queue)) { 1666 spin_lock(&sk_queue->lock); 1667 skb_queue_splice_tail_init(sk_queue, rcvq); 1668 spin_unlock(&sk_queue->lock); 1669 1670 skb = __first_packet_length(sk, rcvq, &total); 1671 } 1672 res = skb ? skb->len : -1; 1673 if (total) 1674 udp_rmem_release(sk, total, 1, false); 1675 spin_unlock_bh(&rcvq->lock); 1676 return res; 1677 } 1678 1679 /* 1680 * IOCTL requests applicable to the UDP protocol 1681 */ 1682 1683 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1684 { 1685 switch (cmd) { 1686 case SIOCOUTQ: 1687 { 1688 int amount = sk_wmem_alloc_get(sk); 1689 1690 return put_user(amount, (int __user *)arg); 1691 } 1692 1693 case SIOCINQ: 1694 { 1695 int amount = max_t(int, 0, first_packet_length(sk)); 1696 1697 return put_user(amount, (int __user *)arg); 1698 } 1699 1700 default: 1701 return -ENOIOCTLCMD; 1702 } 1703 1704 return 0; 1705 } 1706 EXPORT_SYMBOL(udp_ioctl); 1707 1708 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, 1709 int noblock, int *off, int *err) 1710 { 1711 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1712 struct sk_buff_head *queue; 1713 struct sk_buff *last; 1714 long timeo; 1715 int error; 1716 1717 queue = &udp_sk(sk)->reader_queue; 1718 flags |= noblock ? MSG_DONTWAIT : 0; 1719 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 1720 do { 1721 struct sk_buff *skb; 1722 1723 error = sock_error(sk); 1724 if (error) 1725 break; 1726 1727 error = -EAGAIN; 1728 do { 1729 spin_lock_bh(&queue->lock); 1730 skb = __skb_try_recv_from_queue(sk, queue, flags, off, 1731 err, &last); 1732 if (skb) { 1733 if (!(flags & MSG_PEEK)) 1734 udp_skb_destructor(sk, skb); 1735 spin_unlock_bh(&queue->lock); 1736 return skb; 1737 } 1738 1739 if (skb_queue_empty_lockless(sk_queue)) { 1740 spin_unlock_bh(&queue->lock); 1741 goto busy_check; 1742 } 1743 1744 /* refill the reader queue and walk it again 1745 * keep both queues locked to avoid re-acquiring 1746 * the sk_receive_queue lock if fwd memory scheduling 1747 * is needed. 1748 */ 1749 spin_lock(&sk_queue->lock); 1750 skb_queue_splice_tail_init(sk_queue, queue); 1751 1752 skb = __skb_try_recv_from_queue(sk, queue, flags, off, 1753 err, &last); 1754 if (skb && !(flags & MSG_PEEK)) 1755 udp_skb_dtor_locked(sk, skb); 1756 spin_unlock(&sk_queue->lock); 1757 spin_unlock_bh(&queue->lock); 1758 if (skb) 1759 return skb; 1760 1761 busy_check: 1762 if (!sk_can_busy_loop(sk)) 1763 break; 1764 1765 sk_busy_loop(sk, flags & MSG_DONTWAIT); 1766 } while (!skb_queue_empty_lockless(sk_queue)); 1767 1768 /* sk_queue is empty, reader_queue may contain peeked packets */ 1769 } while (timeo && 1770 !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue, 1771 &error, &timeo, 1772 (struct sk_buff *)sk_queue)); 1773 1774 *err = error; 1775 return NULL; 1776 } 1777 EXPORT_SYMBOL(__skb_recv_udp); 1778 1779 /* 1780 * This should be easy, if there is something there we 1781 * return it, otherwise we block. 1782 */ 1783 1784 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 1785 int flags, int *addr_len) 1786 { 1787 struct inet_sock *inet = inet_sk(sk); 1788 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 1789 struct sk_buff *skb; 1790 unsigned int ulen, copied; 1791 int off, err, peeking = flags & MSG_PEEK; 1792 int is_udplite = IS_UDPLITE(sk); 1793 bool checksum_valid = false; 1794 1795 if (flags & MSG_ERRQUEUE) 1796 return ip_recv_error(sk, msg, len, addr_len); 1797 1798 try_again: 1799 off = sk_peek_offset(sk, flags); 1800 skb = __skb_recv_udp(sk, flags, noblock, &off, &err); 1801 if (!skb) 1802 return err; 1803 1804 ulen = udp_skb_len(skb); 1805 copied = len; 1806 if (copied > ulen - off) 1807 copied = ulen - off; 1808 else if (copied < ulen) 1809 msg->msg_flags |= MSG_TRUNC; 1810 1811 /* 1812 * If checksum is needed at all, try to do it while copying the 1813 * data. If the data is truncated, or if we only want a partial 1814 * coverage checksum (UDP-Lite), do it before the copy. 1815 */ 1816 1817 if (copied < ulen || peeking || 1818 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { 1819 checksum_valid = udp_skb_csum_unnecessary(skb) || 1820 !__udp_lib_checksum_complete(skb); 1821 if (!checksum_valid) 1822 goto csum_copy_err; 1823 } 1824 1825 if (checksum_valid || udp_skb_csum_unnecessary(skb)) { 1826 if (udp_skb_is_linear(skb)) 1827 err = copy_linear_skb(skb, copied, off, &msg->msg_iter); 1828 else 1829 err = skb_copy_datagram_msg(skb, off, msg, copied); 1830 } else { 1831 err = skb_copy_and_csum_datagram_msg(skb, off, msg); 1832 1833 if (err == -EINVAL) 1834 goto csum_copy_err; 1835 } 1836 1837 if (unlikely(err)) { 1838 if (!peeking) { 1839 atomic_inc(&sk->sk_drops); 1840 UDP_INC_STATS(sock_net(sk), 1841 UDP_MIB_INERRORS, is_udplite); 1842 } 1843 kfree_skb(skb); 1844 return err; 1845 } 1846 1847 if (!peeking) 1848 UDP_INC_STATS(sock_net(sk), 1849 UDP_MIB_INDATAGRAMS, is_udplite); 1850 1851 sock_recv_ts_and_drops(msg, sk, skb); 1852 1853 /* Copy the address. */ 1854 if (sin) { 1855 sin->sin_family = AF_INET; 1856 sin->sin_port = udp_hdr(skb)->source; 1857 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1858 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1859 *addr_len = sizeof(*sin); 1860 1861 if (cgroup_bpf_enabled) 1862 BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, 1863 (struct sockaddr *)sin); 1864 } 1865 1866 if (udp_sk(sk)->gro_enabled) 1867 udp_cmsg_recv(msg, sk, skb); 1868 1869 if (inet->cmsg_flags) 1870 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off); 1871 1872 err = copied; 1873 if (flags & MSG_TRUNC) 1874 err = ulen; 1875 1876 skb_consume_udp(sk, skb, peeking ? -err : err); 1877 return err; 1878 1879 csum_copy_err: 1880 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, 1881 udp_skb_destructor)) { 1882 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1883 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1884 } 1885 kfree_skb(skb); 1886 1887 /* starting over for a new packet, but check if we need to yield */ 1888 cond_resched(); 1889 msg->msg_flags &= ~MSG_TRUNC; 1890 goto try_again; 1891 } 1892 1893 int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 1894 { 1895 /* This check is replicated from __ip4_datagram_connect() and 1896 * intended to prevent BPF program called below from accessing bytes 1897 * that are out of the bound specified by user in addr_len. 1898 */ 1899 if (addr_len < sizeof(struct sockaddr_in)) 1900 return -EINVAL; 1901 1902 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr); 1903 } 1904 EXPORT_SYMBOL(udp_pre_connect); 1905 1906 int __udp_disconnect(struct sock *sk, int flags) 1907 { 1908 struct inet_sock *inet = inet_sk(sk); 1909 /* 1910 * 1003.1g - break association. 1911 */ 1912 1913 sk->sk_state = TCP_CLOSE; 1914 inet->inet_daddr = 0; 1915 inet->inet_dport = 0; 1916 sock_rps_reset_rxhash(sk); 1917 sk->sk_bound_dev_if = 0; 1918 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) { 1919 inet_reset_saddr(sk); 1920 if (sk->sk_prot->rehash && 1921 (sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 1922 sk->sk_prot->rehash(sk); 1923 } 1924 1925 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1926 sk->sk_prot->unhash(sk); 1927 inet->inet_sport = 0; 1928 } 1929 sk_dst_reset(sk); 1930 return 0; 1931 } 1932 EXPORT_SYMBOL(__udp_disconnect); 1933 1934 int udp_disconnect(struct sock *sk, int flags) 1935 { 1936 lock_sock(sk); 1937 __udp_disconnect(sk, flags); 1938 release_sock(sk); 1939 return 0; 1940 } 1941 EXPORT_SYMBOL(udp_disconnect); 1942 1943 void udp_lib_unhash(struct sock *sk) 1944 { 1945 if (sk_hashed(sk)) { 1946 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1947 struct udp_hslot *hslot, *hslot2; 1948 1949 hslot = udp_hashslot(udptable, sock_net(sk), 1950 udp_sk(sk)->udp_port_hash); 1951 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1952 1953 spin_lock_bh(&hslot->lock); 1954 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1955 reuseport_detach_sock(sk); 1956 if (sk_del_node_init_rcu(sk)) { 1957 hslot->count--; 1958 inet_sk(sk)->inet_num = 0; 1959 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1960 1961 spin_lock(&hslot2->lock); 1962 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1963 hslot2->count--; 1964 spin_unlock(&hslot2->lock); 1965 } 1966 spin_unlock_bh(&hslot->lock); 1967 } 1968 } 1969 EXPORT_SYMBOL(udp_lib_unhash); 1970 1971 /* 1972 * inet_rcv_saddr was changed, we must rehash secondary hash 1973 */ 1974 void udp_lib_rehash(struct sock *sk, u16 newhash) 1975 { 1976 if (sk_hashed(sk)) { 1977 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1978 struct udp_hslot *hslot, *hslot2, *nhslot2; 1979 1980 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1981 nhslot2 = udp_hashslot2(udptable, newhash); 1982 udp_sk(sk)->udp_portaddr_hash = newhash; 1983 1984 if (hslot2 != nhslot2 || 1985 rcu_access_pointer(sk->sk_reuseport_cb)) { 1986 hslot = udp_hashslot(udptable, sock_net(sk), 1987 udp_sk(sk)->udp_port_hash); 1988 /* we must lock primary chain too */ 1989 spin_lock_bh(&hslot->lock); 1990 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1991 reuseport_detach_sock(sk); 1992 1993 if (hslot2 != nhslot2) { 1994 spin_lock(&hslot2->lock); 1995 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1996 hslot2->count--; 1997 spin_unlock(&hslot2->lock); 1998 1999 spin_lock(&nhslot2->lock); 2000 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 2001 &nhslot2->head); 2002 nhslot2->count++; 2003 spin_unlock(&nhslot2->lock); 2004 } 2005 2006 spin_unlock_bh(&hslot->lock); 2007 } 2008 } 2009 } 2010 EXPORT_SYMBOL(udp_lib_rehash); 2011 2012 void udp_v4_rehash(struct sock *sk) 2013 { 2014 u16 new_hash = ipv4_portaddr_hash(sock_net(sk), 2015 inet_sk(sk)->inet_rcv_saddr, 2016 inet_sk(sk)->inet_num); 2017 udp_lib_rehash(sk, new_hash); 2018 } 2019 2020 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 2021 { 2022 int rc; 2023 2024 if (inet_sk(sk)->inet_daddr) { 2025 sock_rps_save_rxhash(sk, skb); 2026 sk_mark_napi_id(sk, skb); 2027 sk_incoming_cpu_update(sk); 2028 } else { 2029 sk_mark_napi_id_once(sk, skb); 2030 } 2031 2032 rc = __udp_enqueue_schedule_skb(sk, skb); 2033 if (rc < 0) { 2034 int is_udplite = IS_UDPLITE(sk); 2035 2036 /* Note that an ENOMEM error is charged twice */ 2037 if (rc == -ENOMEM) 2038 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, 2039 is_udplite); 2040 else 2041 UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS, 2042 is_udplite); 2043 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 2044 kfree_skb(skb); 2045 trace_udp_fail_queue_rcv_skb(rc, sk); 2046 return -1; 2047 } 2048 2049 return 0; 2050 } 2051 2052 /* returns: 2053 * -1: error 2054 * 0: success 2055 * >0: "udp encap" protocol resubmission 2056 * 2057 * Note that in the success and error cases, the skb is assumed to 2058 * have either been requeued or freed. 2059 */ 2060 static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb) 2061 { 2062 struct udp_sock *up = udp_sk(sk); 2063 int is_udplite = IS_UDPLITE(sk); 2064 2065 /* 2066 * Charge it to the socket, dropping if the queue is full. 2067 */ 2068 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 2069 goto drop; 2070 nf_reset_ct(skb); 2071 2072 if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) { 2073 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 2074 2075 /* 2076 * This is an encapsulation socket so pass the skb to 2077 * the socket's udp_encap_rcv() hook. Otherwise, just 2078 * fall through and pass this up the UDP socket. 2079 * up->encap_rcv() returns the following value: 2080 * =0 if skb was successfully passed to the encap 2081 * handler or was discarded by it. 2082 * >0 if skb should be passed on to UDP. 2083 * <0 if skb should be resubmitted as proto -N 2084 */ 2085 2086 /* if we're overly short, let UDP handle it */ 2087 encap_rcv = READ_ONCE(up->encap_rcv); 2088 if (encap_rcv) { 2089 int ret; 2090 2091 /* Verify checksum before giving to encap */ 2092 if (udp_lib_checksum_complete(skb)) 2093 goto csum_error; 2094 2095 ret = encap_rcv(sk, skb); 2096 if (ret <= 0) { 2097 __UDP_INC_STATS(sock_net(sk), 2098 UDP_MIB_INDATAGRAMS, 2099 is_udplite); 2100 return -ret; 2101 } 2102 } 2103 2104 /* FALLTHROUGH -- it's a UDP Packet */ 2105 } 2106 2107 /* 2108 * UDP-Lite specific tests, ignored on UDP sockets 2109 */ 2110 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 2111 2112 /* 2113 * MIB statistics other than incrementing the error count are 2114 * disabled for the following two types of errors: these depend 2115 * on the application settings, not on the functioning of the 2116 * protocol stack as such. 2117 * 2118 * RFC 3828 here recommends (sec 3.3): "There should also be a 2119 * way ... to ... at least let the receiving application block 2120 * delivery of packets with coverage values less than a value 2121 * provided by the application." 2122 */ 2123 if (up->pcrlen == 0) { /* full coverage was set */ 2124 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n", 2125 UDP_SKB_CB(skb)->cscov, skb->len); 2126 goto drop; 2127 } 2128 /* The next case involves violating the min. coverage requested 2129 * by the receiver. This is subtle: if receiver wants x and x is 2130 * greater than the buffersize/MTU then receiver will complain 2131 * that it wants x while sender emits packets of smaller size y. 2132 * Therefore the above ...()->partial_cov statement is essential. 2133 */ 2134 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 2135 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n", 2136 UDP_SKB_CB(skb)->cscov, up->pcrlen); 2137 goto drop; 2138 } 2139 } 2140 2141 prefetch(&sk->sk_rmem_alloc); 2142 if (rcu_access_pointer(sk->sk_filter) && 2143 udp_lib_checksum_complete(skb)) 2144 goto csum_error; 2145 2146 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 2147 goto drop; 2148 2149 udp_csum_pull_header(skb); 2150 2151 ipv4_pktinfo_prepare(sk, skb); 2152 return __udp_queue_rcv_skb(sk, skb); 2153 2154 csum_error: 2155 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 2156 drop: 2157 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 2158 atomic_inc(&sk->sk_drops); 2159 kfree_skb(skb); 2160 return -1; 2161 } 2162 2163 static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 2164 { 2165 struct sk_buff *next, *segs; 2166 int ret; 2167 2168 if (likely(!udp_unexpected_gso(sk, skb))) 2169 return udp_queue_rcv_one_skb(sk, skb); 2170 2171 BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET); 2172 __skb_push(skb, -skb_mac_offset(skb)); 2173 segs = udp_rcv_segment(sk, skb, true); 2174 skb_list_walk_safe(segs, skb, next) { 2175 __skb_pull(skb, skb_transport_offset(skb)); 2176 ret = udp_queue_rcv_one_skb(sk, skb); 2177 if (ret > 0) 2178 ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret); 2179 } 2180 return 0; 2181 } 2182 2183 /* For TCP sockets, sk_rx_dst is protected by socket lock 2184 * For UDP, we use xchg() to guard against concurrent changes. 2185 */ 2186 bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 2187 { 2188 struct dst_entry *old; 2189 2190 if (dst_hold_safe(dst)) { 2191 old = xchg(&sk->sk_rx_dst, dst); 2192 dst_release(old); 2193 return old != dst; 2194 } 2195 return false; 2196 } 2197 EXPORT_SYMBOL(udp_sk_rx_dst_set); 2198 2199 /* 2200 * Multicasts and broadcasts go to each listener. 2201 * 2202 * Note: called only from the BH handler context. 2203 */ 2204 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 2205 struct udphdr *uh, 2206 __be32 saddr, __be32 daddr, 2207 struct udp_table *udptable, 2208 int proto) 2209 { 2210 struct sock *sk, *first = NULL; 2211 unsigned short hnum = ntohs(uh->dest); 2212 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 2213 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 2214 unsigned int offset = offsetof(typeof(*sk), sk_node); 2215 int dif = skb->dev->ifindex; 2216 int sdif = inet_sdif(skb); 2217 struct hlist_node *node; 2218 struct sk_buff *nskb; 2219 2220 if (use_hash2) { 2221 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & 2222 udptable->mask; 2223 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask; 2224 start_lookup: 2225 hslot = &udptable->hash2[hash2]; 2226 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 2227 } 2228 2229 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 2230 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr, 2231 uh->source, saddr, dif, sdif, hnum)) 2232 continue; 2233 2234 if (!first) { 2235 first = sk; 2236 continue; 2237 } 2238 nskb = skb_clone(skb, GFP_ATOMIC); 2239 2240 if (unlikely(!nskb)) { 2241 atomic_inc(&sk->sk_drops); 2242 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 2243 IS_UDPLITE(sk)); 2244 __UDP_INC_STATS(net, UDP_MIB_INERRORS, 2245 IS_UDPLITE(sk)); 2246 continue; 2247 } 2248 if (udp_queue_rcv_skb(sk, nskb) > 0) 2249 consume_skb(nskb); 2250 } 2251 2252 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 2253 if (use_hash2 && hash2 != hash2_any) { 2254 hash2 = hash2_any; 2255 goto start_lookup; 2256 } 2257 2258 if (first) { 2259 if (udp_queue_rcv_skb(first, skb) > 0) 2260 consume_skb(skb); 2261 } else { 2262 kfree_skb(skb); 2263 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 2264 proto == IPPROTO_UDPLITE); 2265 } 2266 return 0; 2267 } 2268 2269 /* Initialize UDP checksum. If exited with zero value (success), 2270 * CHECKSUM_UNNECESSARY means, that no more checks are required. 2271 * Otherwise, csum completion requires checksumming packet body, 2272 * including udp header and folding it to skb->csum. 2273 */ 2274 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 2275 int proto) 2276 { 2277 int err; 2278 2279 UDP_SKB_CB(skb)->partial_cov = 0; 2280 UDP_SKB_CB(skb)->cscov = skb->len; 2281 2282 if (proto == IPPROTO_UDPLITE) { 2283 err = udplite_checksum_init(skb, uh); 2284 if (err) 2285 return err; 2286 2287 if (UDP_SKB_CB(skb)->partial_cov) { 2288 skb->csum = inet_compute_pseudo(skb, proto); 2289 return 0; 2290 } 2291 } 2292 2293 /* Note, we are only interested in != 0 or == 0, thus the 2294 * force to int. 2295 */ 2296 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check, 2297 inet_compute_pseudo); 2298 if (err) 2299 return err; 2300 2301 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) { 2302 /* If SW calculated the value, we know it's bad */ 2303 if (skb->csum_complete_sw) 2304 return 1; 2305 2306 /* HW says the value is bad. Let's validate that. 2307 * skb->csum is no longer the full packet checksum, 2308 * so don't treat it as such. 2309 */ 2310 skb_checksum_complete_unset(skb); 2311 } 2312 2313 return 0; 2314 } 2315 2316 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and 2317 * return code conversion for ip layer consumption 2318 */ 2319 static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb, 2320 struct udphdr *uh) 2321 { 2322 int ret; 2323 2324 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 2325 skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo); 2326 2327 ret = udp_queue_rcv_skb(sk, skb); 2328 2329 /* a return value > 0 means to resubmit the input, but 2330 * it wants the return to be -protocol, or 0 2331 */ 2332 if (ret > 0) 2333 return -ret; 2334 return 0; 2335 } 2336 2337 /* 2338 * All we need to do is get the socket, and then do a checksum. 2339 */ 2340 2341 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 2342 int proto) 2343 { 2344 struct sock *sk; 2345 struct udphdr *uh; 2346 unsigned short ulen; 2347 struct rtable *rt = skb_rtable(skb); 2348 __be32 saddr, daddr; 2349 struct net *net = dev_net(skb->dev); 2350 bool refcounted; 2351 2352 /* 2353 * Validate the packet. 2354 */ 2355 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 2356 goto drop; /* No space for header. */ 2357 2358 uh = udp_hdr(skb); 2359 ulen = ntohs(uh->len); 2360 saddr = ip_hdr(skb)->saddr; 2361 daddr = ip_hdr(skb)->daddr; 2362 2363 if (ulen > skb->len) 2364 goto short_packet; 2365 2366 if (proto == IPPROTO_UDP) { 2367 /* UDP validates ulen. */ 2368 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 2369 goto short_packet; 2370 uh = udp_hdr(skb); 2371 } 2372 2373 if (udp4_csum_init(skb, uh, proto)) 2374 goto csum_error; 2375 2376 sk = skb_steal_sock(skb, &refcounted); 2377 if (sk) { 2378 struct dst_entry *dst = skb_dst(skb); 2379 int ret; 2380 2381 if (unlikely(sk->sk_rx_dst != dst)) 2382 udp_sk_rx_dst_set(sk, dst); 2383 2384 ret = udp_unicast_rcv_skb(sk, skb, uh); 2385 if (refcounted) 2386 sock_put(sk); 2387 return ret; 2388 } 2389 2390 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 2391 return __udp4_lib_mcast_deliver(net, skb, uh, 2392 saddr, daddr, udptable, proto); 2393 2394 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 2395 if (sk) 2396 return udp_unicast_rcv_skb(sk, skb, uh); 2397 2398 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 2399 goto drop; 2400 nf_reset_ct(skb); 2401 2402 /* No socket. Drop packet silently, if checksum is wrong */ 2403 if (udp_lib_checksum_complete(skb)) 2404 goto csum_error; 2405 2406 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 2407 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 2408 2409 /* 2410 * Hmm. We got an UDP packet to a port to which we 2411 * don't wanna listen. Ignore it. 2412 */ 2413 kfree_skb(skb); 2414 return 0; 2415 2416 short_packet: 2417 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 2418 proto == IPPROTO_UDPLITE ? "Lite" : "", 2419 &saddr, ntohs(uh->source), 2420 ulen, skb->len, 2421 &daddr, ntohs(uh->dest)); 2422 goto drop; 2423 2424 csum_error: 2425 /* 2426 * RFC1122: OK. Discards the bad packet silently (as far as 2427 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 2428 */ 2429 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 2430 proto == IPPROTO_UDPLITE ? "Lite" : "", 2431 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 2432 ulen); 2433 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 2434 drop: 2435 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 2436 kfree_skb(skb); 2437 return 0; 2438 } 2439 2440 /* We can only early demux multicast if there is a single matching socket. 2441 * If more than one socket found returns NULL 2442 */ 2443 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, 2444 __be16 loc_port, __be32 loc_addr, 2445 __be16 rmt_port, __be32 rmt_addr, 2446 int dif, int sdif) 2447 { 2448 struct sock *sk, *result; 2449 unsigned short hnum = ntohs(loc_port); 2450 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask); 2451 struct udp_hslot *hslot = &udp_table.hash[slot]; 2452 2453 /* Do not bother scanning a too big list */ 2454 if (hslot->count > 10) 2455 return NULL; 2456 2457 result = NULL; 2458 sk_for_each_rcu(sk, &hslot->head) { 2459 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr, 2460 rmt_port, rmt_addr, dif, sdif, hnum)) { 2461 if (result) 2462 return NULL; 2463 result = sk; 2464 } 2465 } 2466 2467 return result; 2468 } 2469 2470 /* For unicast we should only early demux connected sockets or we can 2471 * break forwarding setups. The chains here can be long so only check 2472 * if the first socket is an exact match and if not move on. 2473 */ 2474 static struct sock *__udp4_lib_demux_lookup(struct net *net, 2475 __be16 loc_port, __be32 loc_addr, 2476 __be16 rmt_port, __be32 rmt_addr, 2477 int dif, int sdif) 2478 { 2479 unsigned short hnum = ntohs(loc_port); 2480 unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum); 2481 unsigned int slot2 = hash2 & udp_table.mask; 2482 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 2483 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); 2484 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 2485 struct sock *sk; 2486 2487 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 2488 if (INET_MATCH(sk, net, acookie, rmt_addr, 2489 loc_addr, ports, dif, sdif)) 2490 return sk; 2491 /* Only check first socket in chain */ 2492 break; 2493 } 2494 return NULL; 2495 } 2496 2497 int udp_v4_early_demux(struct sk_buff *skb) 2498 { 2499 struct net *net = dev_net(skb->dev); 2500 struct in_device *in_dev = NULL; 2501 const struct iphdr *iph; 2502 const struct udphdr *uh; 2503 struct sock *sk = NULL; 2504 struct dst_entry *dst; 2505 int dif = skb->dev->ifindex; 2506 int sdif = inet_sdif(skb); 2507 int ours; 2508 2509 /* validate the packet */ 2510 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) 2511 return 0; 2512 2513 iph = ip_hdr(skb); 2514 uh = udp_hdr(skb); 2515 2516 if (skb->pkt_type == PACKET_MULTICAST) { 2517 in_dev = __in_dev_get_rcu(skb->dev); 2518 2519 if (!in_dev) 2520 return 0; 2521 2522 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, 2523 iph->protocol); 2524 if (!ours) 2525 return 0; 2526 2527 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, 2528 uh->source, iph->saddr, 2529 dif, sdif); 2530 } else if (skb->pkt_type == PACKET_HOST) { 2531 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, 2532 uh->source, iph->saddr, dif, sdif); 2533 } 2534 2535 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 2536 return 0; 2537 2538 skb->sk = sk; 2539 skb->destructor = sock_efree; 2540 dst = READ_ONCE(sk->sk_rx_dst); 2541 2542 if (dst) 2543 dst = dst_check(dst, 0); 2544 if (dst) { 2545 u32 itag = 0; 2546 2547 /* set noref for now. 2548 * any place which wants to hold dst has to call 2549 * dst_hold_safe() 2550 */ 2551 skb_dst_set_noref(skb, dst); 2552 2553 /* for unconnected multicast sockets we need to validate 2554 * the source on each packet 2555 */ 2556 if (!inet_sk(sk)->inet_daddr && in_dev) 2557 return ip_mc_validate_source(skb, iph->daddr, 2558 iph->saddr, iph->tos, 2559 skb->dev, in_dev, &itag); 2560 } 2561 return 0; 2562 } 2563 2564 int udp_rcv(struct sk_buff *skb) 2565 { 2566 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 2567 } 2568 2569 void udp_destroy_sock(struct sock *sk) 2570 { 2571 struct udp_sock *up = udp_sk(sk); 2572 bool slow = lock_sock_fast(sk); 2573 udp_flush_pending_frames(sk); 2574 unlock_sock_fast(sk, slow); 2575 if (static_branch_unlikely(&udp_encap_needed_key)) { 2576 if (up->encap_type) { 2577 void (*encap_destroy)(struct sock *sk); 2578 encap_destroy = READ_ONCE(up->encap_destroy); 2579 if (encap_destroy) 2580 encap_destroy(sk); 2581 } 2582 if (up->encap_enabled) 2583 static_branch_dec(&udp_encap_needed_key); 2584 } 2585 } 2586 2587 /* 2588 * Socket option code for UDP 2589 */ 2590 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 2591 sockptr_t optval, unsigned int optlen, 2592 int (*push_pending_frames)(struct sock *)) 2593 { 2594 struct udp_sock *up = udp_sk(sk); 2595 int val, valbool; 2596 int err = 0; 2597 int is_udplite = IS_UDPLITE(sk); 2598 2599 if (optlen < sizeof(int)) 2600 return -EINVAL; 2601 2602 if (copy_from_sockptr(&val, optval, sizeof(val))) 2603 return -EFAULT; 2604 2605 valbool = val ? 1 : 0; 2606 2607 switch (optname) { 2608 case UDP_CORK: 2609 if (val != 0) { 2610 up->corkflag = 1; 2611 } else { 2612 up->corkflag = 0; 2613 lock_sock(sk); 2614 push_pending_frames(sk); 2615 release_sock(sk); 2616 } 2617 break; 2618 2619 case UDP_ENCAP: 2620 switch (val) { 2621 case 0: 2622 #ifdef CONFIG_XFRM 2623 case UDP_ENCAP_ESPINUDP: 2624 case UDP_ENCAP_ESPINUDP_NON_IKE: 2625 #if IS_ENABLED(CONFIG_IPV6) 2626 if (sk->sk_family == AF_INET6) 2627 up->encap_rcv = ipv6_stub->xfrm6_udp_encap_rcv; 2628 else 2629 #endif 2630 up->encap_rcv = xfrm4_udp_encap_rcv; 2631 #endif 2632 fallthrough; 2633 case UDP_ENCAP_L2TPINUDP: 2634 up->encap_type = val; 2635 lock_sock(sk); 2636 udp_tunnel_encap_enable(sk->sk_socket); 2637 release_sock(sk); 2638 break; 2639 default: 2640 err = -ENOPROTOOPT; 2641 break; 2642 } 2643 break; 2644 2645 case UDP_NO_CHECK6_TX: 2646 up->no_check6_tx = valbool; 2647 break; 2648 2649 case UDP_NO_CHECK6_RX: 2650 up->no_check6_rx = valbool; 2651 break; 2652 2653 case UDP_SEGMENT: 2654 if (val < 0 || val > USHRT_MAX) 2655 return -EINVAL; 2656 up->gso_size = val; 2657 break; 2658 2659 case UDP_GRO: 2660 lock_sock(sk); 2661 if (valbool) 2662 udp_tunnel_encap_enable(sk->sk_socket); 2663 up->gro_enabled = valbool; 2664 release_sock(sk); 2665 break; 2666 2667 /* 2668 * UDP-Lite's partial checksum coverage (RFC 3828). 2669 */ 2670 /* The sender sets actual checksum coverage length via this option. 2671 * The case coverage > packet length is handled by send module. */ 2672 case UDPLITE_SEND_CSCOV: 2673 if (!is_udplite) /* Disable the option on UDP sockets */ 2674 return -ENOPROTOOPT; 2675 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 2676 val = 8; 2677 else if (val > USHRT_MAX) 2678 val = USHRT_MAX; 2679 up->pcslen = val; 2680 up->pcflag |= UDPLITE_SEND_CC; 2681 break; 2682 2683 /* The receiver specifies a minimum checksum coverage value. To make 2684 * sense, this should be set to at least 8 (as done below). If zero is 2685 * used, this again means full checksum coverage. */ 2686 case UDPLITE_RECV_CSCOV: 2687 if (!is_udplite) /* Disable the option on UDP sockets */ 2688 return -ENOPROTOOPT; 2689 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 2690 val = 8; 2691 else if (val > USHRT_MAX) 2692 val = USHRT_MAX; 2693 up->pcrlen = val; 2694 up->pcflag |= UDPLITE_RECV_CC; 2695 break; 2696 2697 default: 2698 err = -ENOPROTOOPT; 2699 break; 2700 } 2701 2702 return err; 2703 } 2704 EXPORT_SYMBOL(udp_lib_setsockopt); 2705 2706 int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 2707 unsigned int optlen) 2708 { 2709 if (level == SOL_UDP || level == SOL_UDPLITE) 2710 return udp_lib_setsockopt(sk, level, optname, 2711 optval, optlen, 2712 udp_push_pending_frames); 2713 return ip_setsockopt(sk, level, optname, optval, optlen); 2714 } 2715 2716 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 2717 char __user *optval, int __user *optlen) 2718 { 2719 struct udp_sock *up = udp_sk(sk); 2720 int val, len; 2721 2722 if (get_user(len, optlen)) 2723 return -EFAULT; 2724 2725 len = min_t(unsigned int, len, sizeof(int)); 2726 2727 if (len < 0) 2728 return -EINVAL; 2729 2730 switch (optname) { 2731 case UDP_CORK: 2732 val = up->corkflag; 2733 break; 2734 2735 case UDP_ENCAP: 2736 val = up->encap_type; 2737 break; 2738 2739 case UDP_NO_CHECK6_TX: 2740 val = up->no_check6_tx; 2741 break; 2742 2743 case UDP_NO_CHECK6_RX: 2744 val = up->no_check6_rx; 2745 break; 2746 2747 case UDP_SEGMENT: 2748 val = up->gso_size; 2749 break; 2750 2751 /* The following two cannot be changed on UDP sockets, the return is 2752 * always 0 (which corresponds to the full checksum coverage of UDP). */ 2753 case UDPLITE_SEND_CSCOV: 2754 val = up->pcslen; 2755 break; 2756 2757 case UDPLITE_RECV_CSCOV: 2758 val = up->pcrlen; 2759 break; 2760 2761 default: 2762 return -ENOPROTOOPT; 2763 } 2764 2765 if (put_user(len, optlen)) 2766 return -EFAULT; 2767 if (copy_to_user(optval, &val, len)) 2768 return -EFAULT; 2769 return 0; 2770 } 2771 EXPORT_SYMBOL(udp_lib_getsockopt); 2772 2773 int udp_getsockopt(struct sock *sk, int level, int optname, 2774 char __user *optval, int __user *optlen) 2775 { 2776 if (level == SOL_UDP || level == SOL_UDPLITE) 2777 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2778 return ip_getsockopt(sk, level, optname, optval, optlen); 2779 } 2780 2781 /** 2782 * udp_poll - wait for a UDP event. 2783 * @file: - file struct 2784 * @sock: - socket 2785 * @wait: - poll table 2786 * 2787 * This is same as datagram poll, except for the special case of 2788 * blocking sockets. If application is using a blocking fd 2789 * and a packet with checksum error is in the queue; 2790 * then it could get return from select indicating data available 2791 * but then block when reading it. Add special case code 2792 * to work around these arguably broken applications. 2793 */ 2794 __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait) 2795 { 2796 __poll_t mask = datagram_poll(file, sock, wait); 2797 struct sock *sk = sock->sk; 2798 2799 if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue)) 2800 mask |= EPOLLIN | EPOLLRDNORM; 2801 2802 /* Check for false positives due to checksum errors */ 2803 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 2804 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1) 2805 mask &= ~(EPOLLIN | EPOLLRDNORM); 2806 2807 return mask; 2808 2809 } 2810 EXPORT_SYMBOL(udp_poll); 2811 2812 int udp_abort(struct sock *sk, int err) 2813 { 2814 lock_sock(sk); 2815 2816 sk->sk_err = err; 2817 sk->sk_error_report(sk); 2818 __udp_disconnect(sk, 0); 2819 2820 release_sock(sk); 2821 2822 return 0; 2823 } 2824 EXPORT_SYMBOL_GPL(udp_abort); 2825 2826 struct proto udp_prot = { 2827 .name = "UDP", 2828 .owner = THIS_MODULE, 2829 .close = udp_lib_close, 2830 .pre_connect = udp_pre_connect, 2831 .connect = ip4_datagram_connect, 2832 .disconnect = udp_disconnect, 2833 .ioctl = udp_ioctl, 2834 .init = udp_init_sock, 2835 .destroy = udp_destroy_sock, 2836 .setsockopt = udp_setsockopt, 2837 .getsockopt = udp_getsockopt, 2838 .sendmsg = udp_sendmsg, 2839 .recvmsg = udp_recvmsg, 2840 .sendpage = udp_sendpage, 2841 .release_cb = ip4_datagram_release_cb, 2842 .hash = udp_lib_hash, 2843 .unhash = udp_lib_unhash, 2844 .rehash = udp_v4_rehash, 2845 .get_port = udp_v4_get_port, 2846 .memory_allocated = &udp_memory_allocated, 2847 .sysctl_mem = sysctl_udp_mem, 2848 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), 2849 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), 2850 .obj_size = sizeof(struct udp_sock), 2851 .h.udp_table = &udp_table, 2852 .diag_destroy = udp_abort, 2853 }; 2854 EXPORT_SYMBOL(udp_prot); 2855 2856 /* ------------------------------------------------------------------------ */ 2857 #ifdef CONFIG_PROC_FS 2858 2859 static struct sock *udp_get_first(struct seq_file *seq, int start) 2860 { 2861 struct sock *sk; 2862 struct udp_seq_afinfo *afinfo; 2863 struct udp_iter_state *state = seq->private; 2864 struct net *net = seq_file_net(seq); 2865 2866 if (state->bpf_seq_afinfo) 2867 afinfo = state->bpf_seq_afinfo; 2868 else 2869 afinfo = PDE_DATA(file_inode(seq->file)); 2870 2871 for (state->bucket = start; state->bucket <= afinfo->udp_table->mask; 2872 ++state->bucket) { 2873 struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket]; 2874 2875 if (hlist_empty(&hslot->head)) 2876 continue; 2877 2878 spin_lock_bh(&hslot->lock); 2879 sk_for_each(sk, &hslot->head) { 2880 if (!net_eq(sock_net(sk), net)) 2881 continue; 2882 if (afinfo->family == AF_UNSPEC || 2883 sk->sk_family == afinfo->family) 2884 goto found; 2885 } 2886 spin_unlock_bh(&hslot->lock); 2887 } 2888 sk = NULL; 2889 found: 2890 return sk; 2891 } 2892 2893 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2894 { 2895 struct udp_seq_afinfo *afinfo; 2896 struct udp_iter_state *state = seq->private; 2897 struct net *net = seq_file_net(seq); 2898 2899 if (state->bpf_seq_afinfo) 2900 afinfo = state->bpf_seq_afinfo; 2901 else 2902 afinfo = PDE_DATA(file_inode(seq->file)); 2903 2904 do { 2905 sk = sk_next(sk); 2906 } while (sk && (!net_eq(sock_net(sk), net) || 2907 (afinfo->family != AF_UNSPEC && 2908 sk->sk_family != afinfo->family))); 2909 2910 if (!sk) { 2911 if (state->bucket <= afinfo->udp_table->mask) 2912 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); 2913 return udp_get_first(seq, state->bucket + 1); 2914 } 2915 return sk; 2916 } 2917 2918 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2919 { 2920 struct sock *sk = udp_get_first(seq, 0); 2921 2922 if (sk) 2923 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2924 --pos; 2925 return pos ? NULL : sk; 2926 } 2927 2928 void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2929 { 2930 struct udp_iter_state *state = seq->private; 2931 state->bucket = MAX_UDP_PORTS; 2932 2933 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2934 } 2935 EXPORT_SYMBOL(udp_seq_start); 2936 2937 void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2938 { 2939 struct sock *sk; 2940 2941 if (v == SEQ_START_TOKEN) 2942 sk = udp_get_idx(seq, 0); 2943 else 2944 sk = udp_get_next(seq, v); 2945 2946 ++*pos; 2947 return sk; 2948 } 2949 EXPORT_SYMBOL(udp_seq_next); 2950 2951 void udp_seq_stop(struct seq_file *seq, void *v) 2952 { 2953 struct udp_seq_afinfo *afinfo; 2954 struct udp_iter_state *state = seq->private; 2955 2956 if (state->bpf_seq_afinfo) 2957 afinfo = state->bpf_seq_afinfo; 2958 else 2959 afinfo = PDE_DATA(file_inode(seq->file)); 2960 2961 if (state->bucket <= afinfo->udp_table->mask) 2962 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); 2963 } 2964 EXPORT_SYMBOL(udp_seq_stop); 2965 2966 /* ------------------------------------------------------------------------ */ 2967 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2968 int bucket) 2969 { 2970 struct inet_sock *inet = inet_sk(sp); 2971 __be32 dest = inet->inet_daddr; 2972 __be32 src = inet->inet_rcv_saddr; 2973 __u16 destp = ntohs(inet->inet_dport); 2974 __u16 srcp = ntohs(inet->inet_sport); 2975 2976 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2977 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 2978 bucket, src, srcp, dest, destp, sp->sk_state, 2979 sk_wmem_alloc_get(sp), 2980 udp_rqueue_get(sp), 2981 0, 0L, 0, 2982 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2983 0, sock_i_ino(sp), 2984 refcount_read(&sp->sk_refcnt), sp, 2985 atomic_read(&sp->sk_drops)); 2986 } 2987 2988 int udp4_seq_show(struct seq_file *seq, void *v) 2989 { 2990 seq_setwidth(seq, 127); 2991 if (v == SEQ_START_TOKEN) 2992 seq_puts(seq, " sl local_address rem_address st tx_queue " 2993 "rx_queue tr tm->when retrnsmt uid timeout " 2994 "inode ref pointer drops"); 2995 else { 2996 struct udp_iter_state *state = seq->private; 2997 2998 udp4_format_sock(v, seq, state->bucket); 2999 } 3000 seq_pad(seq, '\n'); 3001 return 0; 3002 } 3003 3004 #ifdef CONFIG_BPF_SYSCALL 3005 struct bpf_iter__udp { 3006 __bpf_md_ptr(struct bpf_iter_meta *, meta); 3007 __bpf_md_ptr(struct udp_sock *, udp_sk); 3008 uid_t uid __aligned(8); 3009 int bucket __aligned(8); 3010 }; 3011 3012 static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta, 3013 struct udp_sock *udp_sk, uid_t uid, int bucket) 3014 { 3015 struct bpf_iter__udp ctx; 3016 3017 meta->seq_num--; /* skip SEQ_START_TOKEN */ 3018 ctx.meta = meta; 3019 ctx.udp_sk = udp_sk; 3020 ctx.uid = uid; 3021 ctx.bucket = bucket; 3022 return bpf_iter_run_prog(prog, &ctx); 3023 } 3024 3025 static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v) 3026 { 3027 struct udp_iter_state *state = seq->private; 3028 struct bpf_iter_meta meta; 3029 struct bpf_prog *prog; 3030 struct sock *sk = v; 3031 uid_t uid; 3032 3033 if (v == SEQ_START_TOKEN) 3034 return 0; 3035 3036 uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)); 3037 meta.seq = seq; 3038 prog = bpf_iter_get_info(&meta, false); 3039 return udp_prog_seq_show(prog, &meta, v, uid, state->bucket); 3040 } 3041 3042 static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v) 3043 { 3044 struct bpf_iter_meta meta; 3045 struct bpf_prog *prog; 3046 3047 if (!v) { 3048 meta.seq = seq; 3049 prog = bpf_iter_get_info(&meta, true); 3050 if (prog) 3051 (void)udp_prog_seq_show(prog, &meta, v, 0, 0); 3052 } 3053 3054 udp_seq_stop(seq, v); 3055 } 3056 3057 static const struct seq_operations bpf_iter_udp_seq_ops = { 3058 .start = udp_seq_start, 3059 .next = udp_seq_next, 3060 .stop = bpf_iter_udp_seq_stop, 3061 .show = bpf_iter_udp_seq_show, 3062 }; 3063 #endif 3064 3065 const struct seq_operations udp_seq_ops = { 3066 .start = udp_seq_start, 3067 .next = udp_seq_next, 3068 .stop = udp_seq_stop, 3069 .show = udp4_seq_show, 3070 }; 3071 EXPORT_SYMBOL(udp_seq_ops); 3072 3073 static struct udp_seq_afinfo udp4_seq_afinfo = { 3074 .family = AF_INET, 3075 .udp_table = &udp_table, 3076 }; 3077 3078 static int __net_init udp4_proc_init_net(struct net *net) 3079 { 3080 if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops, 3081 sizeof(struct udp_iter_state), &udp4_seq_afinfo)) 3082 return -ENOMEM; 3083 return 0; 3084 } 3085 3086 static void __net_exit udp4_proc_exit_net(struct net *net) 3087 { 3088 remove_proc_entry("udp", net->proc_net); 3089 } 3090 3091 static struct pernet_operations udp4_net_ops = { 3092 .init = udp4_proc_init_net, 3093 .exit = udp4_proc_exit_net, 3094 }; 3095 3096 int __init udp4_proc_init(void) 3097 { 3098 return register_pernet_subsys(&udp4_net_ops); 3099 } 3100 3101 void udp4_proc_exit(void) 3102 { 3103 unregister_pernet_subsys(&udp4_net_ops); 3104 } 3105 #endif /* CONFIG_PROC_FS */ 3106 3107 static __initdata unsigned long uhash_entries; 3108 static int __init set_uhash_entries(char *str) 3109 { 3110 ssize_t ret; 3111 3112 if (!str) 3113 return 0; 3114 3115 ret = kstrtoul(str, 0, &uhash_entries); 3116 if (ret) 3117 return 0; 3118 3119 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 3120 uhash_entries = UDP_HTABLE_SIZE_MIN; 3121 return 1; 3122 } 3123 __setup("uhash_entries=", set_uhash_entries); 3124 3125 void __init udp_table_init(struct udp_table *table, const char *name) 3126 { 3127 unsigned int i; 3128 3129 table->hash = alloc_large_system_hash(name, 3130 2 * sizeof(struct udp_hslot), 3131 uhash_entries, 3132 21, /* one slot per 2 MB */ 3133 0, 3134 &table->log, 3135 &table->mask, 3136 UDP_HTABLE_SIZE_MIN, 3137 64 * 1024); 3138 3139 table->hash2 = table->hash + (table->mask + 1); 3140 for (i = 0; i <= table->mask; i++) { 3141 INIT_HLIST_HEAD(&table->hash[i].head); 3142 table->hash[i].count = 0; 3143 spin_lock_init(&table->hash[i].lock); 3144 } 3145 for (i = 0; i <= table->mask; i++) { 3146 INIT_HLIST_HEAD(&table->hash2[i].head); 3147 table->hash2[i].count = 0; 3148 spin_lock_init(&table->hash2[i].lock); 3149 } 3150 } 3151 3152 u32 udp_flow_hashrnd(void) 3153 { 3154 static u32 hashrnd __read_mostly; 3155 3156 net_get_random_once(&hashrnd, sizeof(hashrnd)); 3157 3158 return hashrnd; 3159 } 3160 EXPORT_SYMBOL(udp_flow_hashrnd); 3161 3162 static void __udp_sysctl_init(struct net *net) 3163 { 3164 net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM; 3165 net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM; 3166 3167 #ifdef CONFIG_NET_L3_MASTER_DEV 3168 net->ipv4.sysctl_udp_l3mdev_accept = 0; 3169 #endif 3170 } 3171 3172 static int __net_init udp_sysctl_init(struct net *net) 3173 { 3174 __udp_sysctl_init(net); 3175 return 0; 3176 } 3177 3178 static struct pernet_operations __net_initdata udp_sysctl_ops = { 3179 .init = udp_sysctl_init, 3180 }; 3181 3182 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 3183 DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta, 3184 struct udp_sock *udp_sk, uid_t uid, int bucket) 3185 3186 static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux) 3187 { 3188 struct udp_iter_state *st = priv_data; 3189 struct udp_seq_afinfo *afinfo; 3190 int ret; 3191 3192 afinfo = kmalloc(sizeof(*afinfo), GFP_USER | __GFP_NOWARN); 3193 if (!afinfo) 3194 return -ENOMEM; 3195 3196 afinfo->family = AF_UNSPEC; 3197 afinfo->udp_table = &udp_table; 3198 st->bpf_seq_afinfo = afinfo; 3199 ret = bpf_iter_init_seq_net(priv_data, aux); 3200 if (ret) 3201 kfree(afinfo); 3202 return ret; 3203 } 3204 3205 static void bpf_iter_fini_udp(void *priv_data) 3206 { 3207 struct udp_iter_state *st = priv_data; 3208 3209 kfree(st->bpf_seq_afinfo); 3210 bpf_iter_fini_seq_net(priv_data); 3211 } 3212 3213 static const struct bpf_iter_seq_info udp_seq_info = { 3214 .seq_ops = &bpf_iter_udp_seq_ops, 3215 .init_seq_private = bpf_iter_init_udp, 3216 .fini_seq_private = bpf_iter_fini_udp, 3217 .seq_priv_size = sizeof(struct udp_iter_state), 3218 }; 3219 3220 static struct bpf_iter_reg udp_reg_info = { 3221 .target = "udp", 3222 .ctx_arg_info_size = 1, 3223 .ctx_arg_info = { 3224 { offsetof(struct bpf_iter__udp, udp_sk), 3225 PTR_TO_BTF_ID_OR_NULL }, 3226 }, 3227 .seq_info = &udp_seq_info, 3228 }; 3229 3230 static void __init bpf_iter_register(void) 3231 { 3232 udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP]; 3233 if (bpf_iter_reg_target(&udp_reg_info)) 3234 pr_warn("Warning: could not register bpf iterator udp\n"); 3235 } 3236 #endif 3237 3238 void __init udp_init(void) 3239 { 3240 unsigned long limit; 3241 unsigned int i; 3242 3243 udp_table_init(&udp_table, "UDP"); 3244 limit = nr_free_buffer_pages() / 8; 3245 limit = max(limit, 128UL); 3246 sysctl_udp_mem[0] = limit / 4 * 3; 3247 sysctl_udp_mem[1] = limit; 3248 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 3249 3250 __udp_sysctl_init(&init_net); 3251 3252 /* 16 spinlocks per cpu */ 3253 udp_busylocks_log = ilog2(nr_cpu_ids) + 4; 3254 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log, 3255 GFP_KERNEL); 3256 if (!udp_busylocks) 3257 panic("UDP: failed to alloc udp_busylocks\n"); 3258 for (i = 0; i < (1U << udp_busylocks_log); i++) 3259 spin_lock_init(udp_busylocks + i); 3260 3261 if (register_pernet_subsys(&udp_sysctl_ops)) 3262 panic("UDP: failed to init sysctl parameters.\n"); 3263 3264 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 3265 bpf_iter_register(); 3266 #endif 3267 } 3268