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