1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * The User Datagram Protocol (UDP). 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 12 * Alan Cox, <alan@lxorguk.ukuu.org.uk> 13 * Hirokazu Takahashi, <taka@valinux.co.jp> 14 * 15 * Fixes: 16 * Alan Cox : verify_area() calls 17 * Alan Cox : stopped close while in use off icmp 18 * messages. Not a fix but a botch that 19 * for udp at least is 'valid'. 20 * Alan Cox : Fixed icmp handling properly 21 * Alan Cox : Correct error for oversized datagrams 22 * Alan Cox : Tidied select() semantics. 23 * Alan Cox : udp_err() fixed properly, also now 24 * select and read wake correctly on errors 25 * Alan Cox : udp_send verify_area moved to avoid mem leak 26 * Alan Cox : UDP can count its memory 27 * Alan Cox : send to an unknown connection causes 28 * an ECONNREFUSED off the icmp, but 29 * does NOT close. 30 * Alan Cox : Switched to new sk_buff handlers. No more backlog! 31 * Alan Cox : Using generic datagram code. Even smaller and the PEEK 32 * bug no longer crashes it. 33 * Fred Van Kempen : Net2e support for sk->broadcast. 34 * Alan Cox : Uses skb_free_datagram 35 * Alan Cox : Added get/set sockopt support. 36 * Alan Cox : Broadcasting without option set returns EACCES. 37 * Alan Cox : No wakeup calls. Instead we now use the callbacks. 38 * Alan Cox : Use ip_tos and ip_ttl 39 * Alan Cox : SNMP Mibs 40 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. 41 * Matt Dillon : UDP length checks. 42 * Alan Cox : Smarter af_inet used properly. 43 * Alan Cox : Use new kernel side addressing. 44 * Alan Cox : Incorrect return on truncated datagram receive. 45 * Arnt Gulbrandsen : New udp_send and stuff 46 * Alan Cox : Cache last socket 47 * Alan Cox : Route cache 48 * Jon Peatfield : Minor efficiency fix to sendto(). 49 * Mike Shaver : RFC1122 checks. 50 * Alan Cox : Nonblocking error fix. 51 * Willy Konynenberg : Transparent proxying support. 52 * Mike McLagan : Routing by source 53 * David S. Miller : New socket lookup architecture. 54 * Last socket cache retained as it 55 * does have a high hit rate. 56 * Olaf Kirch : Don't linearise iovec on sendmsg. 57 * Andi Kleen : Some cleanups, cache destination entry 58 * for connect. 59 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 60 * Melvin Smith : Check msg_name not msg_namelen in sendto(), 61 * return ENOTCONN for unconnected sockets (POSIX) 62 * Janos Farkas : don't deliver multi/broadcasts to a different 63 * bound-to-device socket 64 * Hirokazu Takahashi : HW checksumming for outgoing UDP 65 * datagrams. 66 * Hirokazu Takahashi : sendfile() on UDP works now. 67 * Arnaldo C. Melo : convert /proc/net/udp to seq_file 68 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 69 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind 70 * a single port at the same time. 71 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support 72 * James Chapman : Add L2TP encapsulation type. 73 */ 74 75 #define pr_fmt(fmt) "UDP: " fmt 76 77 #include <linux/uaccess.h> 78 #include <asm/ioctls.h> 79 #include <linux/memblock.h> 80 #include <linux/highmem.h> 81 #include <linux/swap.h> 82 #include <linux/types.h> 83 #include <linux/fcntl.h> 84 #include <linux/module.h> 85 #include <linux/socket.h> 86 #include <linux/sockios.h> 87 #include <linux/igmp.h> 88 #include <linux/inetdevice.h> 89 #include <linux/in.h> 90 #include <linux/errno.h> 91 #include <linux/timer.h> 92 #include <linux/mm.h> 93 #include <linux/inet.h> 94 #include <linux/netdevice.h> 95 #include <linux/slab.h> 96 #include <net/tcp_states.h> 97 #include <linux/skbuff.h> 98 #include <linux/proc_fs.h> 99 #include <linux/seq_file.h> 100 #include <net/net_namespace.h> 101 #include <net/icmp.h> 102 #include <net/inet_hashtables.h> 103 #include <net/ip_tunnels.h> 104 #include <net/route.h> 105 #include <net/checksum.h> 106 #include <net/xfrm.h> 107 #include <trace/events/udp.h> 108 #include <linux/static_key.h> 109 #include <linux/btf_ids.h> 110 #include <trace/events/skb.h> 111 #include <net/busy_poll.h> 112 #include "udp_impl.h" 113 #include <net/sock_reuseport.h> 114 #include <net/addrconf.h> 115 #include <net/udp_tunnel.h> 116 #if IS_ENABLED(CONFIG_IPV6) 117 #include <net/ipv6_stubs.h> 118 #endif 119 120 struct udp_table udp_table __read_mostly; 121 EXPORT_SYMBOL(udp_table); 122 123 long sysctl_udp_mem[3] __read_mostly; 124 EXPORT_SYMBOL(sysctl_udp_mem); 125 126 atomic_long_t udp_memory_allocated; 127 EXPORT_SYMBOL(udp_memory_allocated); 128 129 #define MAX_UDP_PORTS 65536 130 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 131 132 static int udp_lib_lport_inuse(struct net *net, __u16 num, 133 const struct udp_hslot *hslot, 134 unsigned long *bitmap, 135 struct sock *sk, unsigned int log) 136 { 137 struct sock *sk2; 138 kuid_t uid = sock_i_uid(sk); 139 140 sk_for_each(sk2, &hslot->head) { 141 if (net_eq(sock_net(sk2), net) && 142 sk2 != sk && 143 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 144 (!sk2->sk_reuse || !sk->sk_reuse) && 145 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 146 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 147 inet_rcv_saddr_equal(sk, sk2, true)) { 148 if (sk2->sk_reuseport && sk->sk_reuseport && 149 !rcu_access_pointer(sk->sk_reuseport_cb) && 150 uid_eq(uid, sock_i_uid(sk2))) { 151 if (!bitmap) 152 return 0; 153 } else { 154 if (!bitmap) 155 return 1; 156 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 157 bitmap); 158 } 159 } 160 } 161 return 0; 162 } 163 164 /* 165 * Note: we still hold spinlock of primary hash chain, so no other writer 166 * can insert/delete a socket with local_port == num 167 */ 168 static int udp_lib_lport_inuse2(struct net *net, __u16 num, 169 struct udp_hslot *hslot2, 170 struct sock *sk) 171 { 172 struct sock *sk2; 173 kuid_t uid = sock_i_uid(sk); 174 int res = 0; 175 176 spin_lock(&hslot2->lock); 177 udp_portaddr_for_each_entry(sk2, &hslot2->head) { 178 if (net_eq(sock_net(sk2), net) && 179 sk2 != sk && 180 (udp_sk(sk2)->udp_port_hash == num) && 181 (!sk2->sk_reuse || !sk->sk_reuse) && 182 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 183 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 184 inet_rcv_saddr_equal(sk, sk2, true)) { 185 if (sk2->sk_reuseport && sk->sk_reuseport && 186 !rcu_access_pointer(sk->sk_reuseport_cb) && 187 uid_eq(uid, sock_i_uid(sk2))) { 188 res = 0; 189 } else { 190 res = 1; 191 } 192 break; 193 } 194 } 195 spin_unlock(&hslot2->lock); 196 return res; 197 } 198 199 static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot) 200 { 201 struct net *net = sock_net(sk); 202 kuid_t uid = sock_i_uid(sk); 203 struct sock *sk2; 204 205 sk_for_each(sk2, &hslot->head) { 206 if (net_eq(sock_net(sk2), net) && 207 sk2 != sk && 208 sk2->sk_family == sk->sk_family && 209 ipv6_only_sock(sk2) == ipv6_only_sock(sk) && 210 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) && 211 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 212 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && 213 inet_rcv_saddr_equal(sk, sk2, false)) { 214 return reuseport_add_sock(sk, sk2, 215 inet_rcv_saddr_any(sk)); 216 } 217 } 218 219 return reuseport_alloc(sk, inet_rcv_saddr_any(sk)); 220 } 221 222 /** 223 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 224 * 225 * @sk: socket struct in question 226 * @snum: port number to look up 227 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 228 * with NULL address 229 */ 230 int udp_lib_get_port(struct sock *sk, unsigned short snum, 231 unsigned int hash2_nulladdr) 232 { 233 struct udp_hslot *hslot, *hslot2; 234 struct udp_table *udptable = sk->sk_prot->h.udp_table; 235 int error = 1; 236 struct net *net = sock_net(sk); 237 238 if (!snum) { 239 int low, high, remaining; 240 unsigned int rand; 241 unsigned short first, last; 242 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 243 244 inet_get_local_port_range(net, &low, &high); 245 remaining = (high - low) + 1; 246 247 rand = prandom_u32(); 248 first = reciprocal_scale(rand, remaining) + low; 249 /* 250 * force rand to be an odd multiple of UDP_HTABLE_SIZE 251 */ 252 rand = (rand | 1) * (udptable->mask + 1); 253 last = first + udptable->mask + 1; 254 do { 255 hslot = udp_hashslot(udptable, net, first); 256 bitmap_zero(bitmap, PORTS_PER_CHAIN); 257 spin_lock_bh(&hslot->lock); 258 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 259 udptable->log); 260 261 snum = first; 262 /* 263 * Iterate on all possible values of snum for this hash. 264 * Using steps of an odd multiple of UDP_HTABLE_SIZE 265 * give us randomization and full range coverage. 266 */ 267 do { 268 if (low <= snum && snum <= high && 269 !test_bit(snum >> udptable->log, bitmap) && 270 !inet_is_local_reserved_port(net, snum)) 271 goto found; 272 snum += rand; 273 } while (snum != first); 274 spin_unlock_bh(&hslot->lock); 275 cond_resched(); 276 } while (++first != last); 277 goto fail; 278 } else { 279 hslot = udp_hashslot(udptable, net, snum); 280 spin_lock_bh(&hslot->lock); 281 if (hslot->count > 10) { 282 int exist; 283 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 284 285 slot2 &= udptable->mask; 286 hash2_nulladdr &= udptable->mask; 287 288 hslot2 = udp_hashslot2(udptable, slot2); 289 if (hslot->count < hslot2->count) 290 goto scan_primary_hash; 291 292 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk); 293 if (!exist && (hash2_nulladdr != slot2)) { 294 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 295 exist = udp_lib_lport_inuse2(net, snum, hslot2, 296 sk); 297 } 298 if (exist) 299 goto fail_unlock; 300 else 301 goto found; 302 } 303 scan_primary_hash: 304 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0)) 305 goto fail_unlock; 306 } 307 found: 308 inet_sk(sk)->inet_num = snum; 309 udp_sk(sk)->udp_port_hash = snum; 310 udp_sk(sk)->udp_portaddr_hash ^= snum; 311 if (sk_unhashed(sk)) { 312 if (sk->sk_reuseport && 313 udp_reuseport_add_sock(sk, hslot)) { 314 inet_sk(sk)->inet_num = 0; 315 udp_sk(sk)->udp_port_hash = 0; 316 udp_sk(sk)->udp_portaddr_hash ^= snum; 317 goto fail_unlock; 318 } 319 320 sk_add_node_rcu(sk, &hslot->head); 321 hslot->count++; 322 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 323 324 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 325 spin_lock(&hslot2->lock); 326 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 327 sk->sk_family == AF_INET6) 328 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node, 329 &hslot2->head); 330 else 331 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 332 &hslot2->head); 333 hslot2->count++; 334 spin_unlock(&hslot2->lock); 335 } 336 sock_set_flag(sk, SOCK_RCU_FREE); 337 error = 0; 338 fail_unlock: 339 spin_unlock_bh(&hslot->lock); 340 fail: 341 return error; 342 } 343 EXPORT_SYMBOL(udp_lib_get_port); 344 345 int udp_v4_get_port(struct sock *sk, unsigned short snum) 346 { 347 unsigned int hash2_nulladdr = 348 ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 349 unsigned int hash2_partial = 350 ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 351 352 /* precompute partial secondary hash */ 353 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 354 return udp_lib_get_port(sk, snum, hash2_nulladdr); 355 } 356 357 static int compute_score(struct sock *sk, struct net *net, 358 __be32 saddr, __be16 sport, 359 __be32 daddr, unsigned short hnum, 360 int dif, int sdif) 361 { 362 int score; 363 struct inet_sock *inet; 364 bool dev_match; 365 366 if (!net_eq(sock_net(sk), net) || 367 udp_sk(sk)->udp_port_hash != hnum || 368 ipv6_only_sock(sk)) 369 return -1; 370 371 if (sk->sk_rcv_saddr != daddr) 372 return -1; 373 374 score = (sk->sk_family == PF_INET) ? 2 : 1; 375 376 inet = inet_sk(sk); 377 if (inet->inet_daddr) { 378 if (inet->inet_daddr != saddr) 379 return -1; 380 score += 4; 381 } 382 383 if (inet->inet_dport) { 384 if (inet->inet_dport != sport) 385 return -1; 386 score += 4; 387 } 388 389 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, 390 dif, sdif); 391 if (!dev_match) 392 return -1; 393 score += 4; 394 395 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) 396 score++; 397 return score; 398 } 399 400 static u32 udp_ehashfn(const struct net *net, const __be32 laddr, 401 const __u16 lport, const __be32 faddr, 402 const __be16 fport) 403 { 404 static u32 udp_ehash_secret __read_mostly; 405 406 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); 407 408 return __inet_ehashfn(laddr, lport, faddr, fport, 409 udp_ehash_secret + net_hash_mix(net)); 410 } 411 412 static struct sock *lookup_reuseport(struct net *net, struct sock *sk, 413 struct sk_buff *skb, 414 __be32 saddr, __be16 sport, 415 __be32 daddr, unsigned short hnum) 416 { 417 struct sock *reuse_sk = NULL; 418 u32 hash; 419 420 if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) { 421 hash = udp_ehashfn(net, daddr, hnum, saddr, sport); 422 reuse_sk = reuseport_select_sock(sk, hash, skb, 423 sizeof(struct udphdr)); 424 } 425 return reuse_sk; 426 } 427 428 /* called with rcu_read_lock() */ 429 static struct sock *udp4_lib_lookup2(struct net *net, 430 __be32 saddr, __be16 sport, 431 __be32 daddr, unsigned int hnum, 432 int dif, int sdif, 433 struct udp_hslot *hslot2, 434 struct sk_buff *skb) 435 { 436 struct sock *sk, *result; 437 int score, badness; 438 439 result = NULL; 440 badness = 0; 441 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 442 score = compute_score(sk, net, saddr, sport, 443 daddr, hnum, dif, sdif); 444 if (score > badness) { 445 result = lookup_reuseport(net, sk, skb, 446 saddr, sport, daddr, hnum); 447 /* Fall back to scoring if group has connections */ 448 if (result && !reuseport_has_conns(sk, false)) 449 return result; 450 451 result = result ? : sk; 452 badness = score; 453 } 454 } 455 return result; 456 } 457 458 static struct sock *udp4_lookup_run_bpf(struct net *net, 459 struct udp_table *udptable, 460 struct sk_buff *skb, 461 __be32 saddr, __be16 sport, 462 __be32 daddr, u16 hnum) 463 { 464 struct sock *sk, *reuse_sk; 465 bool no_reuseport; 466 467 if (udptable != &udp_table) 468 return NULL; /* only UDP is supported */ 469 470 no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP, 471 saddr, sport, daddr, hnum, &sk); 472 if (no_reuseport || IS_ERR_OR_NULL(sk)) 473 return sk; 474 475 reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); 476 if (reuse_sk) 477 sk = reuse_sk; 478 return sk; 479 } 480 481 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 482 * harder than this. -DaveM 483 */ 484 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 485 __be16 sport, __be32 daddr, __be16 dport, int dif, 486 int sdif, struct udp_table *udptable, struct sk_buff *skb) 487 { 488 unsigned short hnum = ntohs(dport); 489 unsigned int hash2, slot2; 490 struct udp_hslot *hslot2; 491 struct sock *result, *sk; 492 493 hash2 = ipv4_portaddr_hash(net, daddr, hnum); 494 slot2 = hash2 & udptable->mask; 495 hslot2 = &udptable->hash2[slot2]; 496 497 /* Lookup connected or non-wildcard socket */ 498 result = udp4_lib_lookup2(net, saddr, sport, 499 daddr, hnum, dif, sdif, 500 hslot2, skb); 501 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED) 502 goto done; 503 504 /* Lookup redirect from BPF */ 505 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { 506 sk = udp4_lookup_run_bpf(net, udptable, skb, 507 saddr, sport, daddr, hnum); 508 if (sk) { 509 result = sk; 510 goto done; 511 } 512 } 513 514 /* Got non-wildcard socket or error on first lookup */ 515 if (result) 516 goto done; 517 518 /* Lookup wildcard sockets */ 519 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 520 slot2 = hash2 & udptable->mask; 521 hslot2 = &udptable->hash2[slot2]; 522 523 result = udp4_lib_lookup2(net, saddr, sport, 524 htonl(INADDR_ANY), hnum, dif, sdif, 525 hslot2, skb); 526 done: 527 if (IS_ERR(result)) 528 return NULL; 529 return result; 530 } 531 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 532 533 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 534 __be16 sport, __be16 dport, 535 struct udp_table *udptable) 536 { 537 const struct iphdr *iph = ip_hdr(skb); 538 539 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 540 iph->daddr, dport, inet_iif(skb), 541 inet_sdif(skb), udptable, skb); 542 } 543 544 struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb, 545 __be16 sport, __be16 dport) 546 { 547 const struct iphdr *iph = ip_hdr(skb); 548 549 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 550 iph->daddr, dport, inet_iif(skb), 551 inet_sdif(skb), &udp_table, NULL); 552 } 553 554 /* Must be called under rcu_read_lock(). 555 * Does increment socket refcount. 556 */ 557 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4) 558 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 559 __be32 daddr, __be16 dport, int dif) 560 { 561 struct sock *sk; 562 563 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport, 564 dif, 0, &udp_table, NULL); 565 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) 566 sk = NULL; 567 return sk; 568 } 569 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 570 #endif 571 572 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, 573 __be16 loc_port, __be32 loc_addr, 574 __be16 rmt_port, __be32 rmt_addr, 575 int dif, int sdif, unsigned short hnum) 576 { 577 struct inet_sock *inet = inet_sk(sk); 578 579 if (!net_eq(sock_net(sk), net) || 580 udp_sk(sk)->udp_port_hash != hnum || 581 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 582 (inet->inet_dport != rmt_port && inet->inet_dport) || 583 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) || 584 ipv6_only_sock(sk) || 585 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif)) 586 return false; 587 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif)) 588 return false; 589 return true; 590 } 591 592 DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key); 593 void udp_encap_enable(void) 594 { 595 static_branch_inc(&udp_encap_needed_key); 596 } 597 EXPORT_SYMBOL(udp_encap_enable); 598 599 void udp_encap_disable(void) 600 { 601 static_branch_dec(&udp_encap_needed_key); 602 } 603 EXPORT_SYMBOL(udp_encap_disable); 604 605 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go 606 * through error handlers in encapsulations looking for a match. 607 */ 608 static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info) 609 { 610 int i; 611 612 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { 613 int (*handler)(struct sk_buff *skb, u32 info); 614 const struct ip_tunnel_encap_ops *encap; 615 616 encap = rcu_dereference(iptun_encaps[i]); 617 if (!encap) 618 continue; 619 handler = encap->err_handler; 620 if (handler && !handler(skb, info)) 621 return 0; 622 } 623 624 return -ENOENT; 625 } 626 627 /* Try to match ICMP errors to UDP tunnels by looking up a socket without 628 * reversing source and destination port: this will match tunnels that force the 629 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that 630 * lwtunnels might actually break this assumption by being configured with 631 * different destination ports on endpoints, in this case we won't be able to 632 * trace ICMP messages back to them. 633 * 634 * If this doesn't match any socket, probe tunnels with arbitrary destination 635 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port 636 * we've sent packets to won't necessarily match the local destination port. 637 * 638 * Then ask the tunnel implementation to match the error against a valid 639 * association. 640 * 641 * Return an error if we can't find a match, the socket if we need further 642 * processing, zero otherwise. 643 */ 644 static struct sock *__udp4_lib_err_encap(struct net *net, 645 const struct iphdr *iph, 646 struct udphdr *uh, 647 struct udp_table *udptable, 648 struct sk_buff *skb, u32 info) 649 { 650 int network_offset, transport_offset; 651 struct sock *sk; 652 653 network_offset = skb_network_offset(skb); 654 transport_offset = skb_transport_offset(skb); 655 656 /* Network header needs to point to the outer IPv4 header inside ICMP */ 657 skb_reset_network_header(skb); 658 659 /* Transport header needs to point to the UDP header */ 660 skb_set_transport_header(skb, iph->ihl << 2); 661 662 sk = __udp4_lib_lookup(net, iph->daddr, uh->source, 663 iph->saddr, uh->dest, skb->dev->ifindex, 0, 664 udptable, NULL); 665 if (sk) { 666 int (*lookup)(struct sock *sk, struct sk_buff *skb); 667 struct udp_sock *up = udp_sk(sk); 668 669 lookup = READ_ONCE(up->encap_err_lookup); 670 if (!lookup || lookup(sk, skb)) 671 sk = NULL; 672 } 673 674 if (!sk) 675 sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info)); 676 677 skb_set_transport_header(skb, transport_offset); 678 skb_set_network_header(skb, network_offset); 679 680 return sk; 681 } 682 683 /* 684 * This routine is called by the ICMP module when it gets some 685 * sort of error condition. If err < 0 then the socket should 686 * be closed and the error returned to the user. If err > 0 687 * it's just the icmp type << 8 | icmp code. 688 * Header points to the ip header of the error packet. We move 689 * on past this. Then (as it used to claim before adjustment) 690 * header points to the first 8 bytes of the udp header. We need 691 * to find the appropriate port. 692 */ 693 694 int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 695 { 696 struct inet_sock *inet; 697 const struct iphdr *iph = (const struct iphdr *)skb->data; 698 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 699 const int type = icmp_hdr(skb)->type; 700 const int code = icmp_hdr(skb)->code; 701 bool tunnel = false; 702 struct sock *sk; 703 int harderr; 704 int err; 705 struct net *net = dev_net(skb->dev); 706 707 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 708 iph->saddr, uh->source, skb->dev->ifindex, 709 inet_sdif(skb), udptable, NULL); 710 if (!sk || udp_sk(sk)->encap_type) { 711 /* No socket for error: try tunnels before discarding */ 712 sk = ERR_PTR(-ENOENT); 713 if (static_branch_unlikely(&udp_encap_needed_key)) { 714 sk = __udp4_lib_err_encap(net, iph, uh, udptable, skb, 715 info); 716 if (!sk) 717 return 0; 718 } 719 720 if (IS_ERR(sk)) { 721 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); 722 return PTR_ERR(sk); 723 } 724 725 tunnel = true; 726 } 727 728 err = 0; 729 harderr = 0; 730 inet = inet_sk(sk); 731 732 switch (type) { 733 default: 734 case ICMP_TIME_EXCEEDED: 735 err = EHOSTUNREACH; 736 break; 737 case ICMP_SOURCE_QUENCH: 738 goto out; 739 case ICMP_PARAMETERPROB: 740 err = EPROTO; 741 harderr = 1; 742 break; 743 case ICMP_DEST_UNREACH: 744 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 745 ipv4_sk_update_pmtu(skb, sk, info); 746 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 747 err = EMSGSIZE; 748 harderr = 1; 749 break; 750 } 751 goto out; 752 } 753 err = EHOSTUNREACH; 754 if (code <= NR_ICMP_UNREACH) { 755 harderr = icmp_err_convert[code].fatal; 756 err = icmp_err_convert[code].errno; 757 } 758 break; 759 case ICMP_REDIRECT: 760 ipv4_sk_redirect(skb, sk); 761 goto out; 762 } 763 764 /* 765 * RFC1122: OK. Passes ICMP errors back to application, as per 766 * 4.1.3.3. 767 */ 768 if (tunnel) { 769 /* ...not for tunnels though: we don't have a sending socket */ 770 goto out; 771 } 772 if (!inet->recverr) { 773 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 774 goto out; 775 } else 776 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 777 778 sk->sk_err = err; 779 sk->sk_error_report(sk); 780 out: 781 return 0; 782 } 783 784 int udp_err(struct sk_buff *skb, u32 info) 785 { 786 return __udp4_lib_err(skb, info, &udp_table); 787 } 788 789 /* 790 * Throw away all pending data and cancel the corking. Socket is locked. 791 */ 792 void udp_flush_pending_frames(struct sock *sk) 793 { 794 struct udp_sock *up = udp_sk(sk); 795 796 if (up->pending) { 797 up->len = 0; 798 up->pending = 0; 799 ip_flush_pending_frames(sk); 800 } 801 } 802 EXPORT_SYMBOL(udp_flush_pending_frames); 803 804 /** 805 * udp4_hwcsum - handle outgoing HW checksumming 806 * @skb: sk_buff containing the filled-in UDP header 807 * (checksum field must be zeroed out) 808 * @src: source IP address 809 * @dst: destination IP address 810 */ 811 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 812 { 813 struct udphdr *uh = udp_hdr(skb); 814 int offset = skb_transport_offset(skb); 815 int len = skb->len - offset; 816 int hlen = len; 817 __wsum csum = 0; 818 819 if (!skb_has_frag_list(skb)) { 820 /* 821 * Only one fragment on the socket. 822 */ 823 skb->csum_start = skb_transport_header(skb) - skb->head; 824 skb->csum_offset = offsetof(struct udphdr, check); 825 uh->check = ~csum_tcpudp_magic(src, dst, len, 826 IPPROTO_UDP, 0); 827 } else { 828 struct sk_buff *frags; 829 830 /* 831 * HW-checksum won't work as there are two or more 832 * fragments on the socket so that all csums of sk_buffs 833 * should be together 834 */ 835 skb_walk_frags(skb, frags) { 836 csum = csum_add(csum, frags->csum); 837 hlen -= frags->len; 838 } 839 840 csum = skb_checksum(skb, offset, hlen, csum); 841 skb->ip_summed = CHECKSUM_NONE; 842 843 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 844 if (uh->check == 0) 845 uh->check = CSUM_MANGLED_0; 846 } 847 } 848 EXPORT_SYMBOL_GPL(udp4_hwcsum); 849 850 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended 851 * for the simple case like when setting the checksum for a UDP tunnel. 852 */ 853 void udp_set_csum(bool nocheck, struct sk_buff *skb, 854 __be32 saddr, __be32 daddr, int len) 855 { 856 struct udphdr *uh = udp_hdr(skb); 857 858 if (nocheck) { 859 uh->check = 0; 860 } else if (skb_is_gso(skb)) { 861 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 862 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { 863 uh->check = 0; 864 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb)); 865 if (uh->check == 0) 866 uh->check = CSUM_MANGLED_0; 867 } else { 868 skb->ip_summed = CHECKSUM_PARTIAL; 869 skb->csum_start = skb_transport_header(skb) - skb->head; 870 skb->csum_offset = offsetof(struct udphdr, check); 871 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 872 } 873 } 874 EXPORT_SYMBOL(udp_set_csum); 875 876 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4, 877 struct inet_cork *cork) 878 { 879 struct sock *sk = skb->sk; 880 struct inet_sock *inet = inet_sk(sk); 881 struct udphdr *uh; 882 int err; 883 int is_udplite = IS_UDPLITE(sk); 884 int offset = skb_transport_offset(skb); 885 int len = skb->len - offset; 886 int datalen = len - sizeof(*uh); 887 __wsum csum = 0; 888 889 /* 890 * Create a UDP header 891 */ 892 uh = udp_hdr(skb); 893 uh->source = inet->inet_sport; 894 uh->dest = fl4->fl4_dport; 895 uh->len = htons(len); 896 uh->check = 0; 897 898 if (cork->gso_size) { 899 const int hlen = skb_network_header_len(skb) + 900 sizeof(struct udphdr); 901 902 if (hlen + cork->gso_size > cork->fragsize) { 903 kfree_skb(skb); 904 return -EINVAL; 905 } 906 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) { 907 kfree_skb(skb); 908 return -EINVAL; 909 } 910 if (sk->sk_no_check_tx) { 911 kfree_skb(skb); 912 return -EINVAL; 913 } 914 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || 915 dst_xfrm(skb_dst(skb))) { 916 kfree_skb(skb); 917 return -EIO; 918 } 919 920 if (datalen > cork->gso_size) { 921 skb_shinfo(skb)->gso_size = cork->gso_size; 922 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; 923 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, 924 cork->gso_size); 925 } 926 goto csum_partial; 927 } 928 929 if (is_udplite) /* UDP-Lite */ 930 csum = udplite_csum(skb); 931 932 else if (sk->sk_no_check_tx) { /* UDP csum off */ 933 934 skb->ip_summed = CHECKSUM_NONE; 935 goto send; 936 937 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 938 csum_partial: 939 940 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 941 goto send; 942 943 } else 944 csum = udp_csum(skb); 945 946 /* add protocol-dependent pseudo-header */ 947 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 948 sk->sk_protocol, csum); 949 if (uh->check == 0) 950 uh->check = CSUM_MANGLED_0; 951 952 send: 953 err = ip_send_skb(sock_net(sk), skb); 954 if (err) { 955 if (err == -ENOBUFS && !inet->recverr) { 956 UDP_INC_STATS(sock_net(sk), 957 UDP_MIB_SNDBUFERRORS, is_udplite); 958 err = 0; 959 } 960 } else 961 UDP_INC_STATS(sock_net(sk), 962 UDP_MIB_OUTDATAGRAMS, is_udplite); 963 return err; 964 } 965 966 /* 967 * Push out all pending data as one UDP datagram. Socket is locked. 968 */ 969 int udp_push_pending_frames(struct sock *sk) 970 { 971 struct udp_sock *up = udp_sk(sk); 972 struct inet_sock *inet = inet_sk(sk); 973 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 974 struct sk_buff *skb; 975 int err = 0; 976 977 skb = ip_finish_skb(sk, fl4); 978 if (!skb) 979 goto out; 980 981 err = udp_send_skb(skb, fl4, &inet->cork.base); 982 983 out: 984 up->len = 0; 985 up->pending = 0; 986 return err; 987 } 988 EXPORT_SYMBOL(udp_push_pending_frames); 989 990 static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size) 991 { 992 switch (cmsg->cmsg_type) { 993 case UDP_SEGMENT: 994 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16))) 995 return -EINVAL; 996 *gso_size = *(__u16 *)CMSG_DATA(cmsg); 997 return 0; 998 default: 999 return -EINVAL; 1000 } 1001 } 1002 1003 int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size) 1004 { 1005 struct cmsghdr *cmsg; 1006 bool need_ip = false; 1007 int err; 1008 1009 for_each_cmsghdr(cmsg, msg) { 1010 if (!CMSG_OK(msg, cmsg)) 1011 return -EINVAL; 1012 1013 if (cmsg->cmsg_level != SOL_UDP) { 1014 need_ip = true; 1015 continue; 1016 } 1017 1018 err = __udp_cmsg_send(cmsg, gso_size); 1019 if (err) 1020 return err; 1021 } 1022 1023 return need_ip; 1024 } 1025 EXPORT_SYMBOL_GPL(udp_cmsg_send); 1026 1027 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 1028 { 1029 struct inet_sock *inet = inet_sk(sk); 1030 struct udp_sock *up = udp_sk(sk); 1031 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 1032 struct flowi4 fl4_stack; 1033 struct flowi4 *fl4; 1034 int ulen = len; 1035 struct ipcm_cookie ipc; 1036 struct rtable *rt = NULL; 1037 int free = 0; 1038 int connected = 0; 1039 __be32 daddr, faddr, saddr; 1040 __be16 dport; 1041 u8 tos; 1042 int err, is_udplite = IS_UDPLITE(sk); 1043 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 1044 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 1045 struct sk_buff *skb; 1046 struct ip_options_data opt_copy; 1047 1048 if (len > 0xFFFF) 1049 return -EMSGSIZE; 1050 1051 /* 1052 * Check the flags. 1053 */ 1054 1055 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 1056 return -EOPNOTSUPP; 1057 1058 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 1059 1060 fl4 = &inet->cork.fl.u.ip4; 1061 if (up->pending) { 1062 /* 1063 * There are pending frames. 1064 * The socket lock must be held while it's corked. 1065 */ 1066 lock_sock(sk); 1067 if (likely(up->pending)) { 1068 if (unlikely(up->pending != AF_INET)) { 1069 release_sock(sk); 1070 return -EINVAL; 1071 } 1072 goto do_append_data; 1073 } 1074 release_sock(sk); 1075 } 1076 ulen += sizeof(struct udphdr); 1077 1078 /* 1079 * Get and verify the address. 1080 */ 1081 if (usin) { 1082 if (msg->msg_namelen < sizeof(*usin)) 1083 return -EINVAL; 1084 if (usin->sin_family != AF_INET) { 1085 if (usin->sin_family != AF_UNSPEC) 1086 return -EAFNOSUPPORT; 1087 } 1088 1089 daddr = usin->sin_addr.s_addr; 1090 dport = usin->sin_port; 1091 if (dport == 0) 1092 return -EINVAL; 1093 } else { 1094 if (sk->sk_state != TCP_ESTABLISHED) 1095 return -EDESTADDRREQ; 1096 daddr = inet->inet_daddr; 1097 dport = inet->inet_dport; 1098 /* Open fast path for connected socket. 1099 Route will not be used, if at least one option is set. 1100 */ 1101 connected = 1; 1102 } 1103 1104 ipcm_init_sk(&ipc, inet); 1105 ipc.gso_size = up->gso_size; 1106 1107 if (msg->msg_controllen) { 1108 err = udp_cmsg_send(sk, msg, &ipc.gso_size); 1109 if (err > 0) 1110 err = ip_cmsg_send(sk, msg, &ipc, 1111 sk->sk_family == AF_INET6); 1112 if (unlikely(err < 0)) { 1113 kfree(ipc.opt); 1114 return err; 1115 } 1116 if (ipc.opt) 1117 free = 1; 1118 connected = 0; 1119 } 1120 if (!ipc.opt) { 1121 struct ip_options_rcu *inet_opt; 1122 1123 rcu_read_lock(); 1124 inet_opt = rcu_dereference(inet->inet_opt); 1125 if (inet_opt) { 1126 memcpy(&opt_copy, inet_opt, 1127 sizeof(*inet_opt) + inet_opt->opt.optlen); 1128 ipc.opt = &opt_copy.opt; 1129 } 1130 rcu_read_unlock(); 1131 } 1132 1133 if (cgroup_bpf_enabled(BPF_CGROUP_UDP4_SENDMSG) && !connected) { 1134 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, 1135 (struct sockaddr *)usin, &ipc.addr); 1136 if (err) 1137 goto out_free; 1138 if (usin) { 1139 if (usin->sin_port == 0) { 1140 /* BPF program set invalid port. Reject it. */ 1141 err = -EINVAL; 1142 goto out_free; 1143 } 1144 daddr = usin->sin_addr.s_addr; 1145 dport = usin->sin_port; 1146 } 1147 } 1148 1149 saddr = ipc.addr; 1150 ipc.addr = faddr = daddr; 1151 1152 if (ipc.opt && ipc.opt->opt.srr) { 1153 if (!daddr) { 1154 err = -EINVAL; 1155 goto out_free; 1156 } 1157 faddr = ipc.opt->opt.faddr; 1158 connected = 0; 1159 } 1160 tos = get_rttos(&ipc, inet); 1161 if (sock_flag(sk, SOCK_LOCALROUTE) || 1162 (msg->msg_flags & MSG_DONTROUTE) || 1163 (ipc.opt && ipc.opt->opt.is_strictroute)) { 1164 tos |= RTO_ONLINK; 1165 connected = 0; 1166 } 1167 1168 if (ipv4_is_multicast(daddr)) { 1169 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 1170 ipc.oif = inet->mc_index; 1171 if (!saddr) 1172 saddr = inet->mc_addr; 1173 connected = 0; 1174 } else if (!ipc.oif) { 1175 ipc.oif = inet->uc_index; 1176 } else if (ipv4_is_lbcast(daddr) && inet->uc_index) { 1177 /* oif is set, packet is to local broadcast and 1178 * uc_index is set. oif is most likely set 1179 * by sk_bound_dev_if. If uc_index != oif check if the 1180 * oif is an L3 master and uc_index is an L3 slave. 1181 * If so, we want to allow the send using the uc_index. 1182 */ 1183 if (ipc.oif != inet->uc_index && 1184 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk), 1185 inet->uc_index)) { 1186 ipc.oif = inet->uc_index; 1187 } 1188 } 1189 1190 if (connected) 1191 rt = (struct rtable *)sk_dst_check(sk, 0); 1192 1193 if (!rt) { 1194 struct net *net = sock_net(sk); 1195 __u8 flow_flags = inet_sk_flowi_flags(sk); 1196 1197 fl4 = &fl4_stack; 1198 1199 flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos, 1200 RT_SCOPE_UNIVERSE, sk->sk_protocol, 1201 flow_flags, 1202 faddr, saddr, dport, inet->inet_sport, 1203 sk->sk_uid); 1204 1205 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4)); 1206 rt = ip_route_output_flow(net, fl4, sk); 1207 if (IS_ERR(rt)) { 1208 err = PTR_ERR(rt); 1209 rt = NULL; 1210 if (err == -ENETUNREACH) 1211 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 1212 goto out; 1213 } 1214 1215 err = -EACCES; 1216 if ((rt->rt_flags & RTCF_BROADCAST) && 1217 !sock_flag(sk, SOCK_BROADCAST)) 1218 goto out; 1219 if (connected) 1220 sk_dst_set(sk, dst_clone(&rt->dst)); 1221 } 1222 1223 if (msg->msg_flags&MSG_CONFIRM) 1224 goto do_confirm; 1225 back_from_confirm: 1226 1227 saddr = fl4->saddr; 1228 if (!ipc.addr) 1229 daddr = ipc.addr = fl4->daddr; 1230 1231 /* Lockless fast path for the non-corking case. */ 1232 if (!corkreq) { 1233 struct inet_cork cork; 1234 1235 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen, 1236 sizeof(struct udphdr), &ipc, &rt, 1237 &cork, msg->msg_flags); 1238 err = PTR_ERR(skb); 1239 if (!IS_ERR_OR_NULL(skb)) 1240 err = udp_send_skb(skb, fl4, &cork); 1241 goto out; 1242 } 1243 1244 lock_sock(sk); 1245 if (unlikely(up->pending)) { 1246 /* The socket is already corked while preparing it. */ 1247 /* ... which is an evident application bug. --ANK */ 1248 release_sock(sk); 1249 1250 net_dbg_ratelimited("socket already corked\n"); 1251 err = -EINVAL; 1252 goto out; 1253 } 1254 /* 1255 * Now cork the socket to pend data. 1256 */ 1257 fl4 = &inet->cork.fl.u.ip4; 1258 fl4->daddr = daddr; 1259 fl4->saddr = saddr; 1260 fl4->fl4_dport = dport; 1261 fl4->fl4_sport = inet->inet_sport; 1262 up->pending = AF_INET; 1263 1264 do_append_data: 1265 up->len += ulen; 1266 err = ip_append_data(sk, fl4, getfrag, msg, ulen, 1267 sizeof(struct udphdr), &ipc, &rt, 1268 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1269 if (err) 1270 udp_flush_pending_frames(sk); 1271 else if (!corkreq) 1272 err = udp_push_pending_frames(sk); 1273 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1274 up->pending = 0; 1275 release_sock(sk); 1276 1277 out: 1278 ip_rt_put(rt); 1279 out_free: 1280 if (free) 1281 kfree(ipc.opt); 1282 if (!err) 1283 return len; 1284 /* 1285 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1286 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1287 * we don't have a good statistic (IpOutDiscards but it can be too many 1288 * things). We could add another new stat but at least for now that 1289 * seems like overkill. 1290 */ 1291 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1292 UDP_INC_STATS(sock_net(sk), 1293 UDP_MIB_SNDBUFERRORS, is_udplite); 1294 } 1295 return err; 1296 1297 do_confirm: 1298 if (msg->msg_flags & MSG_PROBE) 1299 dst_confirm_neigh(&rt->dst, &fl4->daddr); 1300 if (!(msg->msg_flags&MSG_PROBE) || len) 1301 goto back_from_confirm; 1302 err = 0; 1303 goto out; 1304 } 1305 EXPORT_SYMBOL(udp_sendmsg); 1306 1307 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1308 size_t size, int flags) 1309 { 1310 struct inet_sock *inet = inet_sk(sk); 1311 struct udp_sock *up = udp_sk(sk); 1312 int ret; 1313 1314 if (flags & MSG_SENDPAGE_NOTLAST) 1315 flags |= MSG_MORE; 1316 1317 if (!up->pending) { 1318 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1319 1320 /* Call udp_sendmsg to specify destination address which 1321 * sendpage interface can't pass. 1322 * This will succeed only when the socket is connected. 1323 */ 1324 ret = udp_sendmsg(sk, &msg, 0); 1325 if (ret < 0) 1326 return ret; 1327 } 1328 1329 lock_sock(sk); 1330 1331 if (unlikely(!up->pending)) { 1332 release_sock(sk); 1333 1334 net_dbg_ratelimited("cork failed\n"); 1335 return -EINVAL; 1336 } 1337 1338 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1339 page, offset, size, flags); 1340 if (ret == -EOPNOTSUPP) { 1341 release_sock(sk); 1342 return sock_no_sendpage(sk->sk_socket, page, offset, 1343 size, flags); 1344 } 1345 if (ret < 0) { 1346 udp_flush_pending_frames(sk); 1347 goto out; 1348 } 1349 1350 up->len += size; 1351 if (!(up->corkflag || (flags&MSG_MORE))) 1352 ret = udp_push_pending_frames(sk); 1353 if (!ret) 1354 ret = size; 1355 out: 1356 release_sock(sk); 1357 return ret; 1358 } 1359 1360 #define UDP_SKB_IS_STATELESS 0x80000000 1361 1362 /* all head states (dst, sk, nf conntrack) except skb extensions are 1363 * cleared by udp_rcv(). 1364 * 1365 * We need to preserve secpath, if present, to eventually process 1366 * IP_CMSG_PASSSEC at recvmsg() time. 1367 * 1368 * Other extensions can be cleared. 1369 */ 1370 static bool udp_try_make_stateless(struct sk_buff *skb) 1371 { 1372 if (!skb_has_extensions(skb)) 1373 return true; 1374 1375 if (!secpath_exists(skb)) { 1376 skb_ext_reset(skb); 1377 return true; 1378 } 1379 1380 return false; 1381 } 1382 1383 static void udp_set_dev_scratch(struct sk_buff *skb) 1384 { 1385 struct udp_dev_scratch *scratch = udp_skb_scratch(skb); 1386 1387 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long)); 1388 scratch->_tsize_state = skb->truesize; 1389 #if BITS_PER_LONG == 64 1390 scratch->len = skb->len; 1391 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb); 1392 scratch->is_linear = !skb_is_nonlinear(skb); 1393 #endif 1394 if (udp_try_make_stateless(skb)) 1395 scratch->_tsize_state |= UDP_SKB_IS_STATELESS; 1396 } 1397 1398 static void udp_skb_csum_unnecessary_set(struct sk_buff *skb) 1399 { 1400 /* We come here after udp_lib_checksum_complete() returned 0. 1401 * This means that __skb_checksum_complete() might have 1402 * set skb->csum_valid to 1. 1403 * On 64bit platforms, we can set csum_unnecessary 1404 * to true, but only if the skb is not shared. 1405 */ 1406 #if BITS_PER_LONG == 64 1407 if (!skb_shared(skb)) 1408 udp_skb_scratch(skb)->csum_unnecessary = true; 1409 #endif 1410 } 1411 1412 static int udp_skb_truesize(struct sk_buff *skb) 1413 { 1414 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS; 1415 } 1416 1417 static bool udp_skb_has_head_state(struct sk_buff *skb) 1418 { 1419 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS); 1420 } 1421 1422 /* fully reclaim rmem/fwd memory allocated for skb */ 1423 static void udp_rmem_release(struct sock *sk, int size, int partial, 1424 bool rx_queue_lock_held) 1425 { 1426 struct udp_sock *up = udp_sk(sk); 1427 struct sk_buff_head *sk_queue; 1428 int amt; 1429 1430 if (likely(partial)) { 1431 up->forward_deficit += size; 1432 size = up->forward_deficit; 1433 if (size < (sk->sk_rcvbuf >> 2) && 1434 !skb_queue_empty(&up->reader_queue)) 1435 return; 1436 } else { 1437 size += up->forward_deficit; 1438 } 1439 up->forward_deficit = 0; 1440 1441 /* acquire the sk_receive_queue for fwd allocated memory scheduling, 1442 * if the called don't held it already 1443 */ 1444 sk_queue = &sk->sk_receive_queue; 1445 if (!rx_queue_lock_held) 1446 spin_lock(&sk_queue->lock); 1447 1448 1449 sk->sk_forward_alloc += size; 1450 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1); 1451 sk->sk_forward_alloc -= amt; 1452 1453 if (amt) 1454 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT); 1455 1456 atomic_sub(size, &sk->sk_rmem_alloc); 1457 1458 /* this can save us from acquiring the rx queue lock on next receive */ 1459 skb_queue_splice_tail_init(sk_queue, &up->reader_queue); 1460 1461 if (!rx_queue_lock_held) 1462 spin_unlock(&sk_queue->lock); 1463 } 1464 1465 /* Note: called with reader_queue.lock held. 1466 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch 1467 * This avoids a cache line miss while receive_queue lock is held. 1468 * Look at __udp_enqueue_schedule_skb() to find where this copy is done. 1469 */ 1470 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb) 1471 { 1472 prefetch(&skb->data); 1473 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false); 1474 } 1475 EXPORT_SYMBOL(udp_skb_destructor); 1476 1477 /* as above, but the caller held the rx queue lock, too */ 1478 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb) 1479 { 1480 prefetch(&skb->data); 1481 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true); 1482 } 1483 1484 /* Idea of busylocks is to let producers grab an extra spinlock 1485 * to relieve pressure on the receive_queue spinlock shared by consumer. 1486 * Under flood, this means that only one producer can be in line 1487 * trying to acquire the receive_queue spinlock. 1488 * These busylock can be allocated on a per cpu manner, instead of a 1489 * per socket one (that would consume a cache line per socket) 1490 */ 1491 static int udp_busylocks_log __read_mostly; 1492 static spinlock_t *udp_busylocks __read_mostly; 1493 1494 static spinlock_t *busylock_acquire(void *ptr) 1495 { 1496 spinlock_t *busy; 1497 1498 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log); 1499 spin_lock(busy); 1500 return busy; 1501 } 1502 1503 static void busylock_release(spinlock_t *busy) 1504 { 1505 if (busy) 1506 spin_unlock(busy); 1507 } 1508 1509 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) 1510 { 1511 struct sk_buff_head *list = &sk->sk_receive_queue; 1512 int rmem, delta, amt, err = -ENOMEM; 1513 spinlock_t *busy = NULL; 1514 int size; 1515 1516 /* try to avoid the costly atomic add/sub pair when the receive 1517 * queue is full; always allow at least a packet 1518 */ 1519 rmem = atomic_read(&sk->sk_rmem_alloc); 1520 if (rmem > sk->sk_rcvbuf) 1521 goto drop; 1522 1523 /* Under mem pressure, it might be helpful to help udp_recvmsg() 1524 * having linear skbs : 1525 * - Reduce memory overhead and thus increase receive queue capacity 1526 * - Less cache line misses at copyout() time 1527 * - Less work at consume_skb() (less alien page frag freeing) 1528 */ 1529 if (rmem > (sk->sk_rcvbuf >> 1)) { 1530 skb_condense(skb); 1531 1532 busy = busylock_acquire(sk); 1533 } 1534 size = skb->truesize; 1535 udp_set_dev_scratch(skb); 1536 1537 /* we drop only if the receive buf is full and the receive 1538 * queue contains some other skb 1539 */ 1540 rmem = atomic_add_return(size, &sk->sk_rmem_alloc); 1541 if (rmem > (size + (unsigned int)sk->sk_rcvbuf)) 1542 goto uncharge_drop; 1543 1544 spin_lock(&list->lock); 1545 if (size >= sk->sk_forward_alloc) { 1546 amt = sk_mem_pages(size); 1547 delta = amt << SK_MEM_QUANTUM_SHIFT; 1548 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) { 1549 err = -ENOBUFS; 1550 spin_unlock(&list->lock); 1551 goto uncharge_drop; 1552 } 1553 1554 sk->sk_forward_alloc += delta; 1555 } 1556 1557 sk->sk_forward_alloc -= size; 1558 1559 /* no need to setup a destructor, we will explicitly release the 1560 * forward allocated memory on dequeue 1561 */ 1562 sock_skb_set_dropcount(sk, skb); 1563 1564 __skb_queue_tail(list, skb); 1565 spin_unlock(&list->lock); 1566 1567 if (!sock_flag(sk, SOCK_DEAD)) 1568 sk->sk_data_ready(sk); 1569 1570 busylock_release(busy); 1571 return 0; 1572 1573 uncharge_drop: 1574 atomic_sub(skb->truesize, &sk->sk_rmem_alloc); 1575 1576 drop: 1577 atomic_inc(&sk->sk_drops); 1578 busylock_release(busy); 1579 return err; 1580 } 1581 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb); 1582 1583 void udp_destruct_sock(struct sock *sk) 1584 { 1585 /* reclaim completely the forward allocated memory */ 1586 struct udp_sock *up = udp_sk(sk); 1587 unsigned int total = 0; 1588 struct sk_buff *skb; 1589 1590 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue); 1591 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) { 1592 total += skb->truesize; 1593 kfree_skb(skb); 1594 } 1595 udp_rmem_release(sk, total, 0, true); 1596 1597 inet_sock_destruct(sk); 1598 } 1599 EXPORT_SYMBOL_GPL(udp_destruct_sock); 1600 1601 int udp_init_sock(struct sock *sk) 1602 { 1603 skb_queue_head_init(&udp_sk(sk)->reader_queue); 1604 sk->sk_destruct = udp_destruct_sock; 1605 return 0; 1606 } 1607 EXPORT_SYMBOL_GPL(udp_init_sock); 1608 1609 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) 1610 { 1611 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) { 1612 bool slow = lock_sock_fast(sk); 1613 1614 sk_peek_offset_bwd(sk, len); 1615 unlock_sock_fast(sk, slow); 1616 } 1617 1618 if (!skb_unref(skb)) 1619 return; 1620 1621 /* In the more common cases we cleared the head states previously, 1622 * see __udp_queue_rcv_skb(). 1623 */ 1624 if (unlikely(udp_skb_has_head_state(skb))) 1625 skb_release_head_state(skb); 1626 __consume_stateless_skb(skb); 1627 } 1628 EXPORT_SYMBOL_GPL(skb_consume_udp); 1629 1630 static struct sk_buff *__first_packet_length(struct sock *sk, 1631 struct sk_buff_head *rcvq, 1632 int *total) 1633 { 1634 struct sk_buff *skb; 1635 1636 while ((skb = skb_peek(rcvq)) != NULL) { 1637 if (udp_lib_checksum_complete(skb)) { 1638 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, 1639 IS_UDPLITE(sk)); 1640 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, 1641 IS_UDPLITE(sk)); 1642 atomic_inc(&sk->sk_drops); 1643 __skb_unlink(skb, rcvq); 1644 *total += skb->truesize; 1645 kfree_skb(skb); 1646 } else { 1647 udp_skb_csum_unnecessary_set(skb); 1648 break; 1649 } 1650 } 1651 return skb; 1652 } 1653 1654 /** 1655 * first_packet_length - return length of first packet in receive queue 1656 * @sk: socket 1657 * 1658 * Drops all bad checksum frames, until a valid one is found. 1659 * Returns the length of found skb, or -1 if none is found. 1660 */ 1661 static int first_packet_length(struct sock *sk) 1662 { 1663 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue; 1664 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1665 struct sk_buff *skb; 1666 int total = 0; 1667 int res; 1668 1669 spin_lock_bh(&rcvq->lock); 1670 skb = __first_packet_length(sk, rcvq, &total); 1671 if (!skb && !skb_queue_empty_lockless(sk_queue)) { 1672 spin_lock(&sk_queue->lock); 1673 skb_queue_splice_tail_init(sk_queue, rcvq); 1674 spin_unlock(&sk_queue->lock); 1675 1676 skb = __first_packet_length(sk, rcvq, &total); 1677 } 1678 res = skb ? skb->len : -1; 1679 if (total) 1680 udp_rmem_release(sk, total, 1, false); 1681 spin_unlock_bh(&rcvq->lock); 1682 return res; 1683 } 1684 1685 /* 1686 * IOCTL requests applicable to the UDP protocol 1687 */ 1688 1689 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1690 { 1691 switch (cmd) { 1692 case SIOCOUTQ: 1693 { 1694 int amount = sk_wmem_alloc_get(sk); 1695 1696 return put_user(amount, (int __user *)arg); 1697 } 1698 1699 case SIOCINQ: 1700 { 1701 int amount = max_t(int, 0, first_packet_length(sk)); 1702 1703 return put_user(amount, (int __user *)arg); 1704 } 1705 1706 default: 1707 return -ENOIOCTLCMD; 1708 } 1709 1710 return 0; 1711 } 1712 EXPORT_SYMBOL(udp_ioctl); 1713 1714 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, 1715 int noblock, int *off, int *err) 1716 { 1717 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1718 struct sk_buff_head *queue; 1719 struct sk_buff *last; 1720 long timeo; 1721 int error; 1722 1723 queue = &udp_sk(sk)->reader_queue; 1724 flags |= noblock ? MSG_DONTWAIT : 0; 1725 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 1726 do { 1727 struct sk_buff *skb; 1728 1729 error = sock_error(sk); 1730 if (error) 1731 break; 1732 1733 error = -EAGAIN; 1734 do { 1735 spin_lock_bh(&queue->lock); 1736 skb = __skb_try_recv_from_queue(sk, queue, flags, off, 1737 err, &last); 1738 if (skb) { 1739 if (!(flags & MSG_PEEK)) 1740 udp_skb_destructor(sk, skb); 1741 spin_unlock_bh(&queue->lock); 1742 return skb; 1743 } 1744 1745 if (skb_queue_empty_lockless(sk_queue)) { 1746 spin_unlock_bh(&queue->lock); 1747 goto busy_check; 1748 } 1749 1750 /* refill the reader queue and walk it again 1751 * keep both queues locked to avoid re-acquiring 1752 * the sk_receive_queue lock if fwd memory scheduling 1753 * is needed. 1754 */ 1755 spin_lock(&sk_queue->lock); 1756 skb_queue_splice_tail_init(sk_queue, queue); 1757 1758 skb = __skb_try_recv_from_queue(sk, queue, flags, off, 1759 err, &last); 1760 if (skb && !(flags & MSG_PEEK)) 1761 udp_skb_dtor_locked(sk, skb); 1762 spin_unlock(&sk_queue->lock); 1763 spin_unlock_bh(&queue->lock); 1764 if (skb) 1765 return skb; 1766 1767 busy_check: 1768 if (!sk_can_busy_loop(sk)) 1769 break; 1770 1771 sk_busy_loop(sk, flags & MSG_DONTWAIT); 1772 } while (!skb_queue_empty_lockless(sk_queue)); 1773 1774 /* sk_queue is empty, reader_queue may contain peeked packets */ 1775 } while (timeo && 1776 !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue, 1777 &error, &timeo, 1778 (struct sk_buff *)sk_queue)); 1779 1780 *err = error; 1781 return NULL; 1782 } 1783 EXPORT_SYMBOL(__skb_recv_udp); 1784 1785 /* 1786 * This should be easy, if there is something there we 1787 * return it, otherwise we block. 1788 */ 1789 1790 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 1791 int flags, int *addr_len) 1792 { 1793 struct inet_sock *inet = inet_sk(sk); 1794 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 1795 struct sk_buff *skb; 1796 unsigned int ulen, copied; 1797 int off, err, peeking = flags & MSG_PEEK; 1798 int is_udplite = IS_UDPLITE(sk); 1799 bool checksum_valid = false; 1800 1801 if (flags & MSG_ERRQUEUE) 1802 return ip_recv_error(sk, msg, len, addr_len); 1803 1804 try_again: 1805 off = sk_peek_offset(sk, flags); 1806 skb = __skb_recv_udp(sk, flags, noblock, &off, &err); 1807 if (!skb) 1808 return err; 1809 1810 ulen = udp_skb_len(skb); 1811 copied = len; 1812 if (copied > ulen - off) 1813 copied = ulen - off; 1814 else if (copied < ulen) 1815 msg->msg_flags |= MSG_TRUNC; 1816 1817 /* 1818 * If checksum is needed at all, try to do it while copying the 1819 * data. If the data is truncated, or if we only want a partial 1820 * coverage checksum (UDP-Lite), do it before the copy. 1821 */ 1822 1823 if (copied < ulen || peeking || 1824 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { 1825 checksum_valid = udp_skb_csum_unnecessary(skb) || 1826 !__udp_lib_checksum_complete(skb); 1827 if (!checksum_valid) 1828 goto csum_copy_err; 1829 } 1830 1831 if (checksum_valid || udp_skb_csum_unnecessary(skb)) { 1832 if (udp_skb_is_linear(skb)) 1833 err = copy_linear_skb(skb, copied, off, &msg->msg_iter); 1834 else 1835 err = skb_copy_datagram_msg(skb, off, msg, copied); 1836 } else { 1837 err = skb_copy_and_csum_datagram_msg(skb, off, msg); 1838 1839 if (err == -EINVAL) 1840 goto csum_copy_err; 1841 } 1842 1843 if (unlikely(err)) { 1844 if (!peeking) { 1845 atomic_inc(&sk->sk_drops); 1846 UDP_INC_STATS(sock_net(sk), 1847 UDP_MIB_INERRORS, is_udplite); 1848 } 1849 kfree_skb(skb); 1850 return err; 1851 } 1852 1853 if (!peeking) 1854 UDP_INC_STATS(sock_net(sk), 1855 UDP_MIB_INDATAGRAMS, is_udplite); 1856 1857 sock_recv_ts_and_drops(msg, sk, skb); 1858 1859 /* Copy the address. */ 1860 if (sin) { 1861 sin->sin_family = AF_INET; 1862 sin->sin_port = udp_hdr(skb)->source; 1863 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1864 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1865 *addr_len = sizeof(*sin); 1866 1867 BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, 1868 (struct sockaddr *)sin); 1869 } 1870 1871 if (udp_sk(sk)->gro_enabled) 1872 udp_cmsg_recv(msg, sk, skb); 1873 1874 if (inet->cmsg_flags) 1875 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off); 1876 1877 err = copied; 1878 if (flags & MSG_TRUNC) 1879 err = ulen; 1880 1881 skb_consume_udp(sk, skb, peeking ? -err : err); 1882 return err; 1883 1884 csum_copy_err: 1885 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, 1886 udp_skb_destructor)) { 1887 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1888 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1889 } 1890 kfree_skb(skb); 1891 1892 /* starting over for a new packet, but check if we need to yield */ 1893 cond_resched(); 1894 msg->msg_flags &= ~MSG_TRUNC; 1895 goto try_again; 1896 } 1897 1898 int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 1899 { 1900 /* This check is replicated from __ip4_datagram_connect() and 1901 * intended to prevent BPF program called below from accessing bytes 1902 * that are out of the bound specified by user in addr_len. 1903 */ 1904 if (addr_len < sizeof(struct sockaddr_in)) 1905 return -EINVAL; 1906 1907 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr); 1908 } 1909 EXPORT_SYMBOL(udp_pre_connect); 1910 1911 int __udp_disconnect(struct sock *sk, int flags) 1912 { 1913 struct inet_sock *inet = inet_sk(sk); 1914 /* 1915 * 1003.1g - break association. 1916 */ 1917 1918 sk->sk_state = TCP_CLOSE; 1919 inet->inet_daddr = 0; 1920 inet->inet_dport = 0; 1921 sock_rps_reset_rxhash(sk); 1922 sk->sk_bound_dev_if = 0; 1923 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) { 1924 inet_reset_saddr(sk); 1925 if (sk->sk_prot->rehash && 1926 (sk->sk_userlocks & SOCK_BINDPORT_LOCK)) 1927 sk->sk_prot->rehash(sk); 1928 } 1929 1930 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1931 sk->sk_prot->unhash(sk); 1932 inet->inet_sport = 0; 1933 } 1934 sk_dst_reset(sk); 1935 return 0; 1936 } 1937 EXPORT_SYMBOL(__udp_disconnect); 1938 1939 int udp_disconnect(struct sock *sk, int flags) 1940 { 1941 lock_sock(sk); 1942 __udp_disconnect(sk, flags); 1943 release_sock(sk); 1944 return 0; 1945 } 1946 EXPORT_SYMBOL(udp_disconnect); 1947 1948 void udp_lib_unhash(struct sock *sk) 1949 { 1950 if (sk_hashed(sk)) { 1951 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1952 struct udp_hslot *hslot, *hslot2; 1953 1954 hslot = udp_hashslot(udptable, sock_net(sk), 1955 udp_sk(sk)->udp_port_hash); 1956 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1957 1958 spin_lock_bh(&hslot->lock); 1959 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1960 reuseport_detach_sock(sk); 1961 if (sk_del_node_init_rcu(sk)) { 1962 hslot->count--; 1963 inet_sk(sk)->inet_num = 0; 1964 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1965 1966 spin_lock(&hslot2->lock); 1967 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1968 hslot2->count--; 1969 spin_unlock(&hslot2->lock); 1970 } 1971 spin_unlock_bh(&hslot->lock); 1972 } 1973 } 1974 EXPORT_SYMBOL(udp_lib_unhash); 1975 1976 /* 1977 * inet_rcv_saddr was changed, we must rehash secondary hash 1978 */ 1979 void udp_lib_rehash(struct sock *sk, u16 newhash) 1980 { 1981 if (sk_hashed(sk)) { 1982 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1983 struct udp_hslot *hslot, *hslot2, *nhslot2; 1984 1985 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1986 nhslot2 = udp_hashslot2(udptable, newhash); 1987 udp_sk(sk)->udp_portaddr_hash = newhash; 1988 1989 if (hslot2 != nhslot2 || 1990 rcu_access_pointer(sk->sk_reuseport_cb)) { 1991 hslot = udp_hashslot(udptable, sock_net(sk), 1992 udp_sk(sk)->udp_port_hash); 1993 /* we must lock primary chain too */ 1994 spin_lock_bh(&hslot->lock); 1995 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1996 reuseport_detach_sock(sk); 1997 1998 if (hslot2 != nhslot2) { 1999 spin_lock(&hslot2->lock); 2000 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 2001 hslot2->count--; 2002 spin_unlock(&hslot2->lock); 2003 2004 spin_lock(&nhslot2->lock); 2005 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 2006 &nhslot2->head); 2007 nhslot2->count++; 2008 spin_unlock(&nhslot2->lock); 2009 } 2010 2011 spin_unlock_bh(&hslot->lock); 2012 } 2013 } 2014 } 2015 EXPORT_SYMBOL(udp_lib_rehash); 2016 2017 void udp_v4_rehash(struct sock *sk) 2018 { 2019 u16 new_hash = ipv4_portaddr_hash(sock_net(sk), 2020 inet_sk(sk)->inet_rcv_saddr, 2021 inet_sk(sk)->inet_num); 2022 udp_lib_rehash(sk, new_hash); 2023 } 2024 2025 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 2026 { 2027 int rc; 2028 2029 if (inet_sk(sk)->inet_daddr) { 2030 sock_rps_save_rxhash(sk, skb); 2031 sk_mark_napi_id(sk, skb); 2032 sk_incoming_cpu_update(sk); 2033 } else { 2034 sk_mark_napi_id_once(sk, skb); 2035 } 2036 2037 rc = __udp_enqueue_schedule_skb(sk, skb); 2038 if (rc < 0) { 2039 int is_udplite = IS_UDPLITE(sk); 2040 2041 /* Note that an ENOMEM error is charged twice */ 2042 if (rc == -ENOMEM) 2043 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, 2044 is_udplite); 2045 else 2046 UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS, 2047 is_udplite); 2048 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 2049 kfree_skb(skb); 2050 trace_udp_fail_queue_rcv_skb(rc, sk); 2051 return -1; 2052 } 2053 2054 return 0; 2055 } 2056 2057 /* returns: 2058 * -1: error 2059 * 0: success 2060 * >0: "udp encap" protocol resubmission 2061 * 2062 * Note that in the success and error cases, the skb is assumed to 2063 * have either been requeued or freed. 2064 */ 2065 static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb) 2066 { 2067 struct udp_sock *up = udp_sk(sk); 2068 int is_udplite = IS_UDPLITE(sk); 2069 2070 /* 2071 * Charge it to the socket, dropping if the queue is full. 2072 */ 2073 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 2074 goto drop; 2075 nf_reset_ct(skb); 2076 2077 if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) { 2078 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 2079 2080 /* 2081 * This is an encapsulation socket so pass the skb to 2082 * the socket's udp_encap_rcv() hook. Otherwise, just 2083 * fall through and pass this up the UDP socket. 2084 * up->encap_rcv() returns the following value: 2085 * =0 if skb was successfully passed to the encap 2086 * handler or was discarded by it. 2087 * >0 if skb should be passed on to UDP. 2088 * <0 if skb should be resubmitted as proto -N 2089 */ 2090 2091 /* if we're overly short, let UDP handle it */ 2092 encap_rcv = READ_ONCE(up->encap_rcv); 2093 if (encap_rcv) { 2094 int ret; 2095 2096 /* Verify checksum before giving to encap */ 2097 if (udp_lib_checksum_complete(skb)) 2098 goto csum_error; 2099 2100 ret = encap_rcv(sk, skb); 2101 if (ret <= 0) { 2102 __UDP_INC_STATS(sock_net(sk), 2103 UDP_MIB_INDATAGRAMS, 2104 is_udplite); 2105 return -ret; 2106 } 2107 } 2108 2109 /* FALLTHROUGH -- it's a UDP Packet */ 2110 } 2111 2112 /* 2113 * UDP-Lite specific tests, ignored on UDP sockets 2114 */ 2115 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 2116 2117 /* 2118 * MIB statistics other than incrementing the error count are 2119 * disabled for the following two types of errors: these depend 2120 * on the application settings, not on the functioning of the 2121 * protocol stack as such. 2122 * 2123 * RFC 3828 here recommends (sec 3.3): "There should also be a 2124 * way ... to ... at least let the receiving application block 2125 * delivery of packets with coverage values less than a value 2126 * provided by the application." 2127 */ 2128 if (up->pcrlen == 0) { /* full coverage was set */ 2129 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n", 2130 UDP_SKB_CB(skb)->cscov, skb->len); 2131 goto drop; 2132 } 2133 /* The next case involves violating the min. coverage requested 2134 * by the receiver. This is subtle: if receiver wants x and x is 2135 * greater than the buffersize/MTU then receiver will complain 2136 * that it wants x while sender emits packets of smaller size y. 2137 * Therefore the above ...()->partial_cov statement is essential. 2138 */ 2139 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 2140 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n", 2141 UDP_SKB_CB(skb)->cscov, up->pcrlen); 2142 goto drop; 2143 } 2144 } 2145 2146 prefetch(&sk->sk_rmem_alloc); 2147 if (rcu_access_pointer(sk->sk_filter) && 2148 udp_lib_checksum_complete(skb)) 2149 goto csum_error; 2150 2151 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 2152 goto drop; 2153 2154 udp_csum_pull_header(skb); 2155 2156 ipv4_pktinfo_prepare(sk, skb); 2157 return __udp_queue_rcv_skb(sk, skb); 2158 2159 csum_error: 2160 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 2161 drop: 2162 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 2163 atomic_inc(&sk->sk_drops); 2164 kfree_skb(skb); 2165 return -1; 2166 } 2167 2168 static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 2169 { 2170 struct sk_buff *next, *segs; 2171 int ret; 2172 2173 if (likely(!udp_unexpected_gso(sk, skb))) 2174 return udp_queue_rcv_one_skb(sk, skb); 2175 2176 BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET); 2177 __skb_push(skb, -skb_mac_offset(skb)); 2178 segs = udp_rcv_segment(sk, skb, true); 2179 skb_list_walk_safe(segs, skb, next) { 2180 __skb_pull(skb, skb_transport_offset(skb)); 2181 ret = udp_queue_rcv_one_skb(sk, skb); 2182 if (ret > 0) 2183 ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret); 2184 } 2185 return 0; 2186 } 2187 2188 /* For TCP sockets, sk_rx_dst is protected by socket lock 2189 * For UDP, we use xchg() to guard against concurrent changes. 2190 */ 2191 bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 2192 { 2193 struct dst_entry *old; 2194 2195 if (dst_hold_safe(dst)) { 2196 old = xchg(&sk->sk_rx_dst, dst); 2197 dst_release(old); 2198 return old != dst; 2199 } 2200 return false; 2201 } 2202 EXPORT_SYMBOL(udp_sk_rx_dst_set); 2203 2204 /* 2205 * Multicasts and broadcasts go to each listener. 2206 * 2207 * Note: called only from the BH handler context. 2208 */ 2209 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 2210 struct udphdr *uh, 2211 __be32 saddr, __be32 daddr, 2212 struct udp_table *udptable, 2213 int proto) 2214 { 2215 struct sock *sk, *first = NULL; 2216 unsigned short hnum = ntohs(uh->dest); 2217 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 2218 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 2219 unsigned int offset = offsetof(typeof(*sk), sk_node); 2220 int dif = skb->dev->ifindex; 2221 int sdif = inet_sdif(skb); 2222 struct hlist_node *node; 2223 struct sk_buff *nskb; 2224 2225 if (use_hash2) { 2226 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & 2227 udptable->mask; 2228 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask; 2229 start_lookup: 2230 hslot = &udptable->hash2[hash2]; 2231 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 2232 } 2233 2234 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 2235 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr, 2236 uh->source, saddr, dif, sdif, hnum)) 2237 continue; 2238 2239 if (!first) { 2240 first = sk; 2241 continue; 2242 } 2243 nskb = skb_clone(skb, GFP_ATOMIC); 2244 2245 if (unlikely(!nskb)) { 2246 atomic_inc(&sk->sk_drops); 2247 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 2248 IS_UDPLITE(sk)); 2249 __UDP_INC_STATS(net, UDP_MIB_INERRORS, 2250 IS_UDPLITE(sk)); 2251 continue; 2252 } 2253 if (udp_queue_rcv_skb(sk, nskb) > 0) 2254 consume_skb(nskb); 2255 } 2256 2257 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 2258 if (use_hash2 && hash2 != hash2_any) { 2259 hash2 = hash2_any; 2260 goto start_lookup; 2261 } 2262 2263 if (first) { 2264 if (udp_queue_rcv_skb(first, skb) > 0) 2265 consume_skb(skb); 2266 } else { 2267 kfree_skb(skb); 2268 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 2269 proto == IPPROTO_UDPLITE); 2270 } 2271 return 0; 2272 } 2273 2274 /* Initialize UDP checksum. If exited with zero value (success), 2275 * CHECKSUM_UNNECESSARY means, that no more checks are required. 2276 * Otherwise, csum completion requires checksumming packet body, 2277 * including udp header and folding it to skb->csum. 2278 */ 2279 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 2280 int proto) 2281 { 2282 int err; 2283 2284 UDP_SKB_CB(skb)->partial_cov = 0; 2285 UDP_SKB_CB(skb)->cscov = skb->len; 2286 2287 if (proto == IPPROTO_UDPLITE) { 2288 err = udplite_checksum_init(skb, uh); 2289 if (err) 2290 return err; 2291 2292 if (UDP_SKB_CB(skb)->partial_cov) { 2293 skb->csum = inet_compute_pseudo(skb, proto); 2294 return 0; 2295 } 2296 } 2297 2298 /* Note, we are only interested in != 0 or == 0, thus the 2299 * force to int. 2300 */ 2301 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check, 2302 inet_compute_pseudo); 2303 if (err) 2304 return err; 2305 2306 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) { 2307 /* If SW calculated the value, we know it's bad */ 2308 if (skb->csum_complete_sw) 2309 return 1; 2310 2311 /* HW says the value is bad. Let's validate that. 2312 * skb->csum is no longer the full packet checksum, 2313 * so don't treat it as such. 2314 */ 2315 skb_checksum_complete_unset(skb); 2316 } 2317 2318 return 0; 2319 } 2320 2321 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and 2322 * return code conversion for ip layer consumption 2323 */ 2324 static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb, 2325 struct udphdr *uh) 2326 { 2327 int ret; 2328 2329 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 2330 skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo); 2331 2332 ret = udp_queue_rcv_skb(sk, skb); 2333 2334 /* a return value > 0 means to resubmit the input, but 2335 * it wants the return to be -protocol, or 0 2336 */ 2337 if (ret > 0) 2338 return -ret; 2339 return 0; 2340 } 2341 2342 /* 2343 * All we need to do is get the socket, and then do a checksum. 2344 */ 2345 2346 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 2347 int proto) 2348 { 2349 struct sock *sk; 2350 struct udphdr *uh; 2351 unsigned short ulen; 2352 struct rtable *rt = skb_rtable(skb); 2353 __be32 saddr, daddr; 2354 struct net *net = dev_net(skb->dev); 2355 bool refcounted; 2356 2357 /* 2358 * Validate the packet. 2359 */ 2360 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 2361 goto drop; /* No space for header. */ 2362 2363 uh = udp_hdr(skb); 2364 ulen = ntohs(uh->len); 2365 saddr = ip_hdr(skb)->saddr; 2366 daddr = ip_hdr(skb)->daddr; 2367 2368 if (ulen > skb->len) 2369 goto short_packet; 2370 2371 if (proto == IPPROTO_UDP) { 2372 /* UDP validates ulen. */ 2373 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 2374 goto short_packet; 2375 uh = udp_hdr(skb); 2376 } 2377 2378 if (udp4_csum_init(skb, uh, proto)) 2379 goto csum_error; 2380 2381 sk = skb_steal_sock(skb, &refcounted); 2382 if (sk) { 2383 struct dst_entry *dst = skb_dst(skb); 2384 int ret; 2385 2386 if (unlikely(sk->sk_rx_dst != dst)) 2387 udp_sk_rx_dst_set(sk, dst); 2388 2389 ret = udp_unicast_rcv_skb(sk, skb, uh); 2390 if (refcounted) 2391 sock_put(sk); 2392 return ret; 2393 } 2394 2395 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 2396 return __udp4_lib_mcast_deliver(net, skb, uh, 2397 saddr, daddr, udptable, proto); 2398 2399 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 2400 if (sk) 2401 return udp_unicast_rcv_skb(sk, skb, uh); 2402 2403 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 2404 goto drop; 2405 nf_reset_ct(skb); 2406 2407 /* No socket. Drop packet silently, if checksum is wrong */ 2408 if (udp_lib_checksum_complete(skb)) 2409 goto csum_error; 2410 2411 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 2412 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 2413 2414 /* 2415 * Hmm. We got an UDP packet to a port to which we 2416 * don't wanna listen. Ignore it. 2417 */ 2418 kfree_skb(skb); 2419 return 0; 2420 2421 short_packet: 2422 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 2423 proto == IPPROTO_UDPLITE ? "Lite" : "", 2424 &saddr, ntohs(uh->source), 2425 ulen, skb->len, 2426 &daddr, ntohs(uh->dest)); 2427 goto drop; 2428 2429 csum_error: 2430 /* 2431 * RFC1122: OK. Discards the bad packet silently (as far as 2432 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 2433 */ 2434 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 2435 proto == IPPROTO_UDPLITE ? "Lite" : "", 2436 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 2437 ulen); 2438 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 2439 drop: 2440 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 2441 kfree_skb(skb); 2442 return 0; 2443 } 2444 2445 /* We can only early demux multicast if there is a single matching socket. 2446 * If more than one socket found returns NULL 2447 */ 2448 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, 2449 __be16 loc_port, __be32 loc_addr, 2450 __be16 rmt_port, __be32 rmt_addr, 2451 int dif, int sdif) 2452 { 2453 struct sock *sk, *result; 2454 unsigned short hnum = ntohs(loc_port); 2455 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask); 2456 struct udp_hslot *hslot = &udp_table.hash[slot]; 2457 2458 /* Do not bother scanning a too big list */ 2459 if (hslot->count > 10) 2460 return NULL; 2461 2462 result = NULL; 2463 sk_for_each_rcu(sk, &hslot->head) { 2464 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr, 2465 rmt_port, rmt_addr, dif, sdif, hnum)) { 2466 if (result) 2467 return NULL; 2468 result = sk; 2469 } 2470 } 2471 2472 return result; 2473 } 2474 2475 /* For unicast we should only early demux connected sockets or we can 2476 * break forwarding setups. The chains here can be long so only check 2477 * if the first socket is an exact match and if not move on. 2478 */ 2479 static struct sock *__udp4_lib_demux_lookup(struct net *net, 2480 __be16 loc_port, __be32 loc_addr, 2481 __be16 rmt_port, __be32 rmt_addr, 2482 int dif, int sdif) 2483 { 2484 unsigned short hnum = ntohs(loc_port); 2485 unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum); 2486 unsigned int slot2 = hash2 & udp_table.mask; 2487 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 2488 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); 2489 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 2490 struct sock *sk; 2491 2492 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 2493 if (INET_MATCH(sk, net, acookie, rmt_addr, 2494 loc_addr, ports, dif, sdif)) 2495 return sk; 2496 /* Only check first socket in chain */ 2497 break; 2498 } 2499 return NULL; 2500 } 2501 2502 int udp_v4_early_demux(struct sk_buff *skb) 2503 { 2504 struct net *net = dev_net(skb->dev); 2505 struct in_device *in_dev = NULL; 2506 const struct iphdr *iph; 2507 const struct udphdr *uh; 2508 struct sock *sk = NULL; 2509 struct dst_entry *dst; 2510 int dif = skb->dev->ifindex; 2511 int sdif = inet_sdif(skb); 2512 int ours; 2513 2514 /* validate the packet */ 2515 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) 2516 return 0; 2517 2518 iph = ip_hdr(skb); 2519 uh = udp_hdr(skb); 2520 2521 if (skb->pkt_type == PACKET_MULTICAST) { 2522 in_dev = __in_dev_get_rcu(skb->dev); 2523 2524 if (!in_dev) 2525 return 0; 2526 2527 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, 2528 iph->protocol); 2529 if (!ours) 2530 return 0; 2531 2532 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, 2533 uh->source, iph->saddr, 2534 dif, sdif); 2535 } else if (skb->pkt_type == PACKET_HOST) { 2536 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, 2537 uh->source, iph->saddr, dif, sdif); 2538 } 2539 2540 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 2541 return 0; 2542 2543 skb->sk = sk; 2544 skb->destructor = sock_efree; 2545 dst = READ_ONCE(sk->sk_rx_dst); 2546 2547 if (dst) 2548 dst = dst_check(dst, 0); 2549 if (dst) { 2550 u32 itag = 0; 2551 2552 /* set noref for now. 2553 * any place which wants to hold dst has to call 2554 * dst_hold_safe() 2555 */ 2556 skb_dst_set_noref(skb, dst); 2557 2558 /* for unconnected multicast sockets we need to validate 2559 * the source on each packet 2560 */ 2561 if (!inet_sk(sk)->inet_daddr && in_dev) 2562 return ip_mc_validate_source(skb, iph->daddr, 2563 iph->saddr, 2564 iph->tos & IPTOS_RT_MASK, 2565 skb->dev, in_dev, &itag); 2566 } 2567 return 0; 2568 } 2569 2570 int udp_rcv(struct sk_buff *skb) 2571 { 2572 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 2573 } 2574 2575 void udp_destroy_sock(struct sock *sk) 2576 { 2577 struct udp_sock *up = udp_sk(sk); 2578 bool slow = lock_sock_fast(sk); 2579 udp_flush_pending_frames(sk); 2580 unlock_sock_fast(sk, slow); 2581 if (static_branch_unlikely(&udp_encap_needed_key)) { 2582 if (up->encap_type) { 2583 void (*encap_destroy)(struct sock *sk); 2584 encap_destroy = READ_ONCE(up->encap_destroy); 2585 if (encap_destroy) 2586 encap_destroy(sk); 2587 } 2588 if (up->encap_enabled) 2589 static_branch_dec(&udp_encap_needed_key); 2590 } 2591 } 2592 2593 /* 2594 * Socket option code for UDP 2595 */ 2596 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 2597 sockptr_t optval, unsigned int optlen, 2598 int (*push_pending_frames)(struct sock *)) 2599 { 2600 struct udp_sock *up = udp_sk(sk); 2601 int val, valbool; 2602 int err = 0; 2603 int is_udplite = IS_UDPLITE(sk); 2604 2605 if (optlen < sizeof(int)) 2606 return -EINVAL; 2607 2608 if (copy_from_sockptr(&val, optval, sizeof(val))) 2609 return -EFAULT; 2610 2611 valbool = val ? 1 : 0; 2612 2613 switch (optname) { 2614 case UDP_CORK: 2615 if (val != 0) { 2616 up->corkflag = 1; 2617 } else { 2618 up->corkflag = 0; 2619 lock_sock(sk); 2620 push_pending_frames(sk); 2621 release_sock(sk); 2622 } 2623 break; 2624 2625 case UDP_ENCAP: 2626 switch (val) { 2627 case 0: 2628 #ifdef CONFIG_XFRM 2629 case UDP_ENCAP_ESPINUDP: 2630 case UDP_ENCAP_ESPINUDP_NON_IKE: 2631 #if IS_ENABLED(CONFIG_IPV6) 2632 if (sk->sk_family == AF_INET6) 2633 up->encap_rcv = ipv6_stub->xfrm6_udp_encap_rcv; 2634 else 2635 #endif 2636 up->encap_rcv = xfrm4_udp_encap_rcv; 2637 #endif 2638 fallthrough; 2639 case UDP_ENCAP_L2TPINUDP: 2640 up->encap_type = val; 2641 lock_sock(sk); 2642 udp_tunnel_encap_enable(sk->sk_socket); 2643 release_sock(sk); 2644 break; 2645 default: 2646 err = -ENOPROTOOPT; 2647 break; 2648 } 2649 break; 2650 2651 case UDP_NO_CHECK6_TX: 2652 up->no_check6_tx = valbool; 2653 break; 2654 2655 case UDP_NO_CHECK6_RX: 2656 up->no_check6_rx = valbool; 2657 break; 2658 2659 case UDP_SEGMENT: 2660 if (val < 0 || val > USHRT_MAX) 2661 return -EINVAL; 2662 up->gso_size = val; 2663 break; 2664 2665 case UDP_GRO: 2666 lock_sock(sk); 2667 if (valbool) 2668 udp_tunnel_encap_enable(sk->sk_socket); 2669 up->gro_enabled = valbool; 2670 release_sock(sk); 2671 break; 2672 2673 /* 2674 * UDP-Lite's partial checksum coverage (RFC 3828). 2675 */ 2676 /* The sender sets actual checksum coverage length via this option. 2677 * The case coverage > packet length is handled by send module. */ 2678 case UDPLITE_SEND_CSCOV: 2679 if (!is_udplite) /* Disable the option on UDP sockets */ 2680 return -ENOPROTOOPT; 2681 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 2682 val = 8; 2683 else if (val > USHRT_MAX) 2684 val = USHRT_MAX; 2685 up->pcslen = val; 2686 up->pcflag |= UDPLITE_SEND_CC; 2687 break; 2688 2689 /* The receiver specifies a minimum checksum coverage value. To make 2690 * sense, this should be set to at least 8 (as done below). If zero is 2691 * used, this again means full checksum coverage. */ 2692 case UDPLITE_RECV_CSCOV: 2693 if (!is_udplite) /* Disable the option on UDP sockets */ 2694 return -ENOPROTOOPT; 2695 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 2696 val = 8; 2697 else if (val > USHRT_MAX) 2698 val = USHRT_MAX; 2699 up->pcrlen = val; 2700 up->pcflag |= UDPLITE_RECV_CC; 2701 break; 2702 2703 default: 2704 err = -ENOPROTOOPT; 2705 break; 2706 } 2707 2708 return err; 2709 } 2710 EXPORT_SYMBOL(udp_lib_setsockopt); 2711 2712 int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 2713 unsigned int optlen) 2714 { 2715 if (level == SOL_UDP || level == SOL_UDPLITE) 2716 return udp_lib_setsockopt(sk, level, optname, 2717 optval, optlen, 2718 udp_push_pending_frames); 2719 return ip_setsockopt(sk, level, optname, optval, optlen); 2720 } 2721 2722 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 2723 char __user *optval, int __user *optlen) 2724 { 2725 struct udp_sock *up = udp_sk(sk); 2726 int val, len; 2727 2728 if (get_user(len, optlen)) 2729 return -EFAULT; 2730 2731 len = min_t(unsigned int, len, sizeof(int)); 2732 2733 if (len < 0) 2734 return -EINVAL; 2735 2736 switch (optname) { 2737 case UDP_CORK: 2738 val = up->corkflag; 2739 break; 2740 2741 case UDP_ENCAP: 2742 val = up->encap_type; 2743 break; 2744 2745 case UDP_NO_CHECK6_TX: 2746 val = up->no_check6_tx; 2747 break; 2748 2749 case UDP_NO_CHECK6_RX: 2750 val = up->no_check6_rx; 2751 break; 2752 2753 case UDP_SEGMENT: 2754 val = up->gso_size; 2755 break; 2756 2757 /* The following two cannot be changed on UDP sockets, the return is 2758 * always 0 (which corresponds to the full checksum coverage of UDP). */ 2759 case UDPLITE_SEND_CSCOV: 2760 val = up->pcslen; 2761 break; 2762 2763 case UDPLITE_RECV_CSCOV: 2764 val = up->pcrlen; 2765 break; 2766 2767 default: 2768 return -ENOPROTOOPT; 2769 } 2770 2771 if (put_user(len, optlen)) 2772 return -EFAULT; 2773 if (copy_to_user(optval, &val, len)) 2774 return -EFAULT; 2775 return 0; 2776 } 2777 EXPORT_SYMBOL(udp_lib_getsockopt); 2778 2779 int udp_getsockopt(struct sock *sk, int level, int optname, 2780 char __user *optval, int __user *optlen) 2781 { 2782 if (level == SOL_UDP || level == SOL_UDPLITE) 2783 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2784 return ip_getsockopt(sk, level, optname, optval, optlen); 2785 } 2786 2787 /** 2788 * udp_poll - wait for a UDP event. 2789 * @file: - file struct 2790 * @sock: - socket 2791 * @wait: - poll table 2792 * 2793 * This is same as datagram poll, except for the special case of 2794 * blocking sockets. If application is using a blocking fd 2795 * and a packet with checksum error is in the queue; 2796 * then it could get return from select indicating data available 2797 * but then block when reading it. Add special case code 2798 * to work around these arguably broken applications. 2799 */ 2800 __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait) 2801 { 2802 __poll_t mask = datagram_poll(file, sock, wait); 2803 struct sock *sk = sock->sk; 2804 2805 if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue)) 2806 mask |= EPOLLIN | EPOLLRDNORM; 2807 2808 /* Check for false positives due to checksum errors */ 2809 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 2810 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1) 2811 mask &= ~(EPOLLIN | EPOLLRDNORM); 2812 2813 return mask; 2814 2815 } 2816 EXPORT_SYMBOL(udp_poll); 2817 2818 int udp_abort(struct sock *sk, int err) 2819 { 2820 lock_sock(sk); 2821 2822 sk->sk_err = err; 2823 sk->sk_error_report(sk); 2824 __udp_disconnect(sk, 0); 2825 2826 release_sock(sk); 2827 2828 return 0; 2829 } 2830 EXPORT_SYMBOL_GPL(udp_abort); 2831 2832 struct proto udp_prot = { 2833 .name = "UDP", 2834 .owner = THIS_MODULE, 2835 .close = udp_lib_close, 2836 .pre_connect = udp_pre_connect, 2837 .connect = ip4_datagram_connect, 2838 .disconnect = udp_disconnect, 2839 .ioctl = udp_ioctl, 2840 .init = udp_init_sock, 2841 .destroy = udp_destroy_sock, 2842 .setsockopt = udp_setsockopt, 2843 .getsockopt = udp_getsockopt, 2844 .sendmsg = udp_sendmsg, 2845 .recvmsg = udp_recvmsg, 2846 .sendpage = udp_sendpage, 2847 .release_cb = ip4_datagram_release_cb, 2848 .hash = udp_lib_hash, 2849 .unhash = udp_lib_unhash, 2850 .rehash = udp_v4_rehash, 2851 .get_port = udp_v4_get_port, 2852 .memory_allocated = &udp_memory_allocated, 2853 .sysctl_mem = sysctl_udp_mem, 2854 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), 2855 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), 2856 .obj_size = sizeof(struct udp_sock), 2857 .h.udp_table = &udp_table, 2858 .diag_destroy = udp_abort, 2859 }; 2860 EXPORT_SYMBOL(udp_prot); 2861 2862 /* ------------------------------------------------------------------------ */ 2863 #ifdef CONFIG_PROC_FS 2864 2865 static struct sock *udp_get_first(struct seq_file *seq, int start) 2866 { 2867 struct sock *sk; 2868 struct udp_seq_afinfo *afinfo; 2869 struct udp_iter_state *state = seq->private; 2870 struct net *net = seq_file_net(seq); 2871 2872 if (state->bpf_seq_afinfo) 2873 afinfo = state->bpf_seq_afinfo; 2874 else 2875 afinfo = PDE_DATA(file_inode(seq->file)); 2876 2877 for (state->bucket = start; state->bucket <= afinfo->udp_table->mask; 2878 ++state->bucket) { 2879 struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket]; 2880 2881 if (hlist_empty(&hslot->head)) 2882 continue; 2883 2884 spin_lock_bh(&hslot->lock); 2885 sk_for_each(sk, &hslot->head) { 2886 if (!net_eq(sock_net(sk), net)) 2887 continue; 2888 if (afinfo->family == AF_UNSPEC || 2889 sk->sk_family == afinfo->family) 2890 goto found; 2891 } 2892 spin_unlock_bh(&hslot->lock); 2893 } 2894 sk = NULL; 2895 found: 2896 return sk; 2897 } 2898 2899 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2900 { 2901 struct udp_seq_afinfo *afinfo; 2902 struct udp_iter_state *state = seq->private; 2903 struct net *net = seq_file_net(seq); 2904 2905 if (state->bpf_seq_afinfo) 2906 afinfo = state->bpf_seq_afinfo; 2907 else 2908 afinfo = PDE_DATA(file_inode(seq->file)); 2909 2910 do { 2911 sk = sk_next(sk); 2912 } while (sk && (!net_eq(sock_net(sk), net) || 2913 (afinfo->family != AF_UNSPEC && 2914 sk->sk_family != afinfo->family))); 2915 2916 if (!sk) { 2917 if (state->bucket <= afinfo->udp_table->mask) 2918 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); 2919 return udp_get_first(seq, state->bucket + 1); 2920 } 2921 return sk; 2922 } 2923 2924 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2925 { 2926 struct sock *sk = udp_get_first(seq, 0); 2927 2928 if (sk) 2929 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2930 --pos; 2931 return pos ? NULL : sk; 2932 } 2933 2934 void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2935 { 2936 struct udp_iter_state *state = seq->private; 2937 state->bucket = MAX_UDP_PORTS; 2938 2939 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2940 } 2941 EXPORT_SYMBOL(udp_seq_start); 2942 2943 void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2944 { 2945 struct sock *sk; 2946 2947 if (v == SEQ_START_TOKEN) 2948 sk = udp_get_idx(seq, 0); 2949 else 2950 sk = udp_get_next(seq, v); 2951 2952 ++*pos; 2953 return sk; 2954 } 2955 EXPORT_SYMBOL(udp_seq_next); 2956 2957 void udp_seq_stop(struct seq_file *seq, void *v) 2958 { 2959 struct udp_seq_afinfo *afinfo; 2960 struct udp_iter_state *state = seq->private; 2961 2962 if (state->bpf_seq_afinfo) 2963 afinfo = state->bpf_seq_afinfo; 2964 else 2965 afinfo = PDE_DATA(file_inode(seq->file)); 2966 2967 if (state->bucket <= afinfo->udp_table->mask) 2968 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); 2969 } 2970 EXPORT_SYMBOL(udp_seq_stop); 2971 2972 /* ------------------------------------------------------------------------ */ 2973 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2974 int bucket) 2975 { 2976 struct inet_sock *inet = inet_sk(sp); 2977 __be32 dest = inet->inet_daddr; 2978 __be32 src = inet->inet_rcv_saddr; 2979 __u16 destp = ntohs(inet->inet_dport); 2980 __u16 srcp = ntohs(inet->inet_sport); 2981 2982 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2983 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 2984 bucket, src, srcp, dest, destp, sp->sk_state, 2985 sk_wmem_alloc_get(sp), 2986 udp_rqueue_get(sp), 2987 0, 0L, 0, 2988 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2989 0, sock_i_ino(sp), 2990 refcount_read(&sp->sk_refcnt), sp, 2991 atomic_read(&sp->sk_drops)); 2992 } 2993 2994 int udp4_seq_show(struct seq_file *seq, void *v) 2995 { 2996 seq_setwidth(seq, 127); 2997 if (v == SEQ_START_TOKEN) 2998 seq_puts(seq, " sl local_address rem_address st tx_queue " 2999 "rx_queue tr tm->when retrnsmt uid timeout " 3000 "inode ref pointer drops"); 3001 else { 3002 struct udp_iter_state *state = seq->private; 3003 3004 udp4_format_sock(v, seq, state->bucket); 3005 } 3006 seq_pad(seq, '\n'); 3007 return 0; 3008 } 3009 3010 #ifdef CONFIG_BPF_SYSCALL 3011 struct bpf_iter__udp { 3012 __bpf_md_ptr(struct bpf_iter_meta *, meta); 3013 __bpf_md_ptr(struct udp_sock *, udp_sk); 3014 uid_t uid __aligned(8); 3015 int bucket __aligned(8); 3016 }; 3017 3018 static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta, 3019 struct udp_sock *udp_sk, uid_t uid, int bucket) 3020 { 3021 struct bpf_iter__udp ctx; 3022 3023 meta->seq_num--; /* skip SEQ_START_TOKEN */ 3024 ctx.meta = meta; 3025 ctx.udp_sk = udp_sk; 3026 ctx.uid = uid; 3027 ctx.bucket = bucket; 3028 return bpf_iter_run_prog(prog, &ctx); 3029 } 3030 3031 static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v) 3032 { 3033 struct udp_iter_state *state = seq->private; 3034 struct bpf_iter_meta meta; 3035 struct bpf_prog *prog; 3036 struct sock *sk = v; 3037 uid_t uid; 3038 3039 if (v == SEQ_START_TOKEN) 3040 return 0; 3041 3042 uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)); 3043 meta.seq = seq; 3044 prog = bpf_iter_get_info(&meta, false); 3045 return udp_prog_seq_show(prog, &meta, v, uid, state->bucket); 3046 } 3047 3048 static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v) 3049 { 3050 struct bpf_iter_meta meta; 3051 struct bpf_prog *prog; 3052 3053 if (!v) { 3054 meta.seq = seq; 3055 prog = bpf_iter_get_info(&meta, true); 3056 if (prog) 3057 (void)udp_prog_seq_show(prog, &meta, v, 0, 0); 3058 } 3059 3060 udp_seq_stop(seq, v); 3061 } 3062 3063 static const struct seq_operations bpf_iter_udp_seq_ops = { 3064 .start = udp_seq_start, 3065 .next = udp_seq_next, 3066 .stop = bpf_iter_udp_seq_stop, 3067 .show = bpf_iter_udp_seq_show, 3068 }; 3069 #endif 3070 3071 const struct seq_operations udp_seq_ops = { 3072 .start = udp_seq_start, 3073 .next = udp_seq_next, 3074 .stop = udp_seq_stop, 3075 .show = udp4_seq_show, 3076 }; 3077 EXPORT_SYMBOL(udp_seq_ops); 3078 3079 static struct udp_seq_afinfo udp4_seq_afinfo = { 3080 .family = AF_INET, 3081 .udp_table = &udp_table, 3082 }; 3083 3084 static int __net_init udp4_proc_init_net(struct net *net) 3085 { 3086 if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops, 3087 sizeof(struct udp_iter_state), &udp4_seq_afinfo)) 3088 return -ENOMEM; 3089 return 0; 3090 } 3091 3092 static void __net_exit udp4_proc_exit_net(struct net *net) 3093 { 3094 remove_proc_entry("udp", net->proc_net); 3095 } 3096 3097 static struct pernet_operations udp4_net_ops = { 3098 .init = udp4_proc_init_net, 3099 .exit = udp4_proc_exit_net, 3100 }; 3101 3102 int __init udp4_proc_init(void) 3103 { 3104 return register_pernet_subsys(&udp4_net_ops); 3105 } 3106 3107 void udp4_proc_exit(void) 3108 { 3109 unregister_pernet_subsys(&udp4_net_ops); 3110 } 3111 #endif /* CONFIG_PROC_FS */ 3112 3113 static __initdata unsigned long uhash_entries; 3114 static int __init set_uhash_entries(char *str) 3115 { 3116 ssize_t ret; 3117 3118 if (!str) 3119 return 0; 3120 3121 ret = kstrtoul(str, 0, &uhash_entries); 3122 if (ret) 3123 return 0; 3124 3125 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 3126 uhash_entries = UDP_HTABLE_SIZE_MIN; 3127 return 1; 3128 } 3129 __setup("uhash_entries=", set_uhash_entries); 3130 3131 void __init udp_table_init(struct udp_table *table, const char *name) 3132 { 3133 unsigned int i; 3134 3135 table->hash = alloc_large_system_hash(name, 3136 2 * sizeof(struct udp_hslot), 3137 uhash_entries, 3138 21, /* one slot per 2 MB */ 3139 0, 3140 &table->log, 3141 &table->mask, 3142 UDP_HTABLE_SIZE_MIN, 3143 64 * 1024); 3144 3145 table->hash2 = table->hash + (table->mask + 1); 3146 for (i = 0; i <= table->mask; i++) { 3147 INIT_HLIST_HEAD(&table->hash[i].head); 3148 table->hash[i].count = 0; 3149 spin_lock_init(&table->hash[i].lock); 3150 } 3151 for (i = 0; i <= table->mask; i++) { 3152 INIT_HLIST_HEAD(&table->hash2[i].head); 3153 table->hash2[i].count = 0; 3154 spin_lock_init(&table->hash2[i].lock); 3155 } 3156 } 3157 3158 u32 udp_flow_hashrnd(void) 3159 { 3160 static u32 hashrnd __read_mostly; 3161 3162 net_get_random_once(&hashrnd, sizeof(hashrnd)); 3163 3164 return hashrnd; 3165 } 3166 EXPORT_SYMBOL(udp_flow_hashrnd); 3167 3168 static void __udp_sysctl_init(struct net *net) 3169 { 3170 net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM; 3171 net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM; 3172 3173 #ifdef CONFIG_NET_L3_MASTER_DEV 3174 net->ipv4.sysctl_udp_l3mdev_accept = 0; 3175 #endif 3176 } 3177 3178 static int __net_init udp_sysctl_init(struct net *net) 3179 { 3180 __udp_sysctl_init(net); 3181 return 0; 3182 } 3183 3184 static struct pernet_operations __net_initdata udp_sysctl_ops = { 3185 .init = udp_sysctl_init, 3186 }; 3187 3188 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 3189 DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta, 3190 struct udp_sock *udp_sk, uid_t uid, int bucket) 3191 3192 static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux) 3193 { 3194 struct udp_iter_state *st = priv_data; 3195 struct udp_seq_afinfo *afinfo; 3196 int ret; 3197 3198 afinfo = kmalloc(sizeof(*afinfo), GFP_USER | __GFP_NOWARN); 3199 if (!afinfo) 3200 return -ENOMEM; 3201 3202 afinfo->family = AF_UNSPEC; 3203 afinfo->udp_table = &udp_table; 3204 st->bpf_seq_afinfo = afinfo; 3205 ret = bpf_iter_init_seq_net(priv_data, aux); 3206 if (ret) 3207 kfree(afinfo); 3208 return ret; 3209 } 3210 3211 static void bpf_iter_fini_udp(void *priv_data) 3212 { 3213 struct udp_iter_state *st = priv_data; 3214 3215 kfree(st->bpf_seq_afinfo); 3216 bpf_iter_fini_seq_net(priv_data); 3217 } 3218 3219 static const struct bpf_iter_seq_info udp_seq_info = { 3220 .seq_ops = &bpf_iter_udp_seq_ops, 3221 .init_seq_private = bpf_iter_init_udp, 3222 .fini_seq_private = bpf_iter_fini_udp, 3223 .seq_priv_size = sizeof(struct udp_iter_state), 3224 }; 3225 3226 static struct bpf_iter_reg udp_reg_info = { 3227 .target = "udp", 3228 .ctx_arg_info_size = 1, 3229 .ctx_arg_info = { 3230 { offsetof(struct bpf_iter__udp, udp_sk), 3231 PTR_TO_BTF_ID_OR_NULL }, 3232 }, 3233 .seq_info = &udp_seq_info, 3234 }; 3235 3236 static void __init bpf_iter_register(void) 3237 { 3238 udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP]; 3239 if (bpf_iter_reg_target(&udp_reg_info)) 3240 pr_warn("Warning: could not register bpf iterator udp\n"); 3241 } 3242 #endif 3243 3244 void __init udp_init(void) 3245 { 3246 unsigned long limit; 3247 unsigned int i; 3248 3249 udp_table_init(&udp_table, "UDP"); 3250 limit = nr_free_buffer_pages() / 8; 3251 limit = max(limit, 128UL); 3252 sysctl_udp_mem[0] = limit / 4 * 3; 3253 sysctl_udp_mem[1] = limit; 3254 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 3255 3256 __udp_sysctl_init(&init_net); 3257 3258 /* 16 spinlocks per cpu */ 3259 udp_busylocks_log = ilog2(nr_cpu_ids) + 4; 3260 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log, 3261 GFP_KERNEL); 3262 if (!udp_busylocks) 3263 panic("UDP: failed to alloc udp_busylocks\n"); 3264 for (i = 0; i < (1U << udp_busylocks_log); i++) 3265 spin_lock_init(udp_busylocks + i); 3266 3267 if (register_pernet_subsys(&udp_sysctl_ops)) 3268 panic("UDP: failed to init sysctl parameters.\n"); 3269 3270 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 3271 bpf_iter_register(); 3272 #endif 3273 } 3274