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