1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * The User Datagram Protocol (UDP). 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 11 * Alan Cox, <alan@lxorguk.ukuu.org.uk> 12 * Hirokazu Takahashi, <taka@valinux.co.jp> 13 * 14 * Fixes: 15 * Alan Cox : verify_area() calls 16 * Alan Cox : stopped close while in use off icmp 17 * messages. Not a fix but a botch that 18 * for udp at least is 'valid'. 19 * Alan Cox : Fixed icmp handling properly 20 * Alan Cox : Correct error for oversized datagrams 21 * Alan Cox : Tidied select() semantics. 22 * Alan Cox : udp_err() fixed properly, also now 23 * select and read wake correctly on errors 24 * Alan Cox : udp_send verify_area moved to avoid mem leak 25 * Alan Cox : UDP can count its memory 26 * Alan Cox : send to an unknown connection causes 27 * an ECONNREFUSED off the icmp, but 28 * does NOT close. 29 * Alan Cox : Switched to new sk_buff handlers. No more backlog! 30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK 31 * bug no longer crashes it. 32 * Fred Van Kempen : Net2e support for sk->broadcast. 33 * Alan Cox : Uses skb_free_datagram 34 * Alan Cox : Added get/set sockopt support. 35 * Alan Cox : Broadcasting without option set returns EACCES. 36 * Alan Cox : No wakeup calls. Instead we now use the callbacks. 37 * Alan Cox : Use ip_tos and ip_ttl 38 * Alan Cox : SNMP Mibs 39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. 40 * Matt Dillon : UDP length checks. 41 * Alan Cox : Smarter af_inet used properly. 42 * Alan Cox : Use new kernel side addressing. 43 * Alan Cox : Incorrect return on truncated datagram receive. 44 * Arnt Gulbrandsen : New udp_send and stuff 45 * Alan Cox : Cache last socket 46 * Alan Cox : Route cache 47 * Jon Peatfield : Minor efficiency fix to sendto(). 48 * Mike Shaver : RFC1122 checks. 49 * Alan Cox : Nonblocking error fix. 50 * Willy Konynenberg : Transparent proxying support. 51 * Mike McLagan : Routing by source 52 * David S. Miller : New socket lookup architecture. 53 * Last socket cache retained as it 54 * does have a high hit rate. 55 * Olaf Kirch : Don't linearise iovec on sendmsg. 56 * Andi Kleen : Some cleanups, cache destination entry 57 * for connect. 58 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 59 * Melvin Smith : Check msg_name not msg_namelen in sendto(), 60 * return ENOTCONN for unconnected sockets (POSIX) 61 * Janos Farkas : don't deliver multi/broadcasts to a different 62 * bound-to-device socket 63 * Hirokazu Takahashi : HW checksumming for outgoing UDP 64 * datagrams. 65 * Hirokazu Takahashi : sendfile() on UDP works now. 66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file 67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind 69 * a single port at the same time. 70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support 71 * James Chapman : Add L2TP encapsulation type. 72 * 73 * 74 * This program is free software; you can redistribute it and/or 75 * modify it under the terms of the GNU General Public License 76 * as published by the Free Software Foundation; either version 77 * 2 of the License, or (at your option) any later version. 78 */ 79 80 #define pr_fmt(fmt) "UDP: " fmt 81 82 #include <linux/uaccess.h> 83 #include <asm/ioctls.h> 84 #include <linux/memblock.h> 85 #include <linux/highmem.h> 86 #include <linux/swap.h> 87 #include <linux/types.h> 88 #include <linux/fcntl.h> 89 #include <linux/module.h> 90 #include <linux/socket.h> 91 #include <linux/sockios.h> 92 #include <linux/igmp.h> 93 #include <linux/inetdevice.h> 94 #include <linux/in.h> 95 #include <linux/errno.h> 96 #include <linux/timer.h> 97 #include <linux/mm.h> 98 #include <linux/inet.h> 99 #include <linux/netdevice.h> 100 #include <linux/slab.h> 101 #include <net/tcp_states.h> 102 #include <linux/skbuff.h> 103 #include <linux/proc_fs.h> 104 #include <linux/seq_file.h> 105 #include <net/net_namespace.h> 106 #include <net/icmp.h> 107 #include <net/inet_hashtables.h> 108 #include <net/ip_tunnels.h> 109 #include <net/route.h> 110 #include <net/checksum.h> 111 #include <net/xfrm.h> 112 #include <trace/events/udp.h> 113 #include <linux/static_key.h> 114 #include <trace/events/skb.h> 115 #include <net/busy_poll.h> 116 #include "udp_impl.h" 117 #include <net/sock_reuseport.h> 118 #include <net/addrconf.h> 119 #include <net/udp_tunnel.h> 120 121 struct udp_table udp_table __read_mostly; 122 EXPORT_SYMBOL(udp_table); 123 124 long sysctl_udp_mem[3] __read_mostly; 125 EXPORT_SYMBOL(sysctl_udp_mem); 126 127 atomic_long_t udp_memory_allocated; 128 EXPORT_SYMBOL(udp_memory_allocated); 129 130 #define MAX_UDP_PORTS 65536 131 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 132 133 /* IPCB reference means this can not be used from early demux */ 134 static bool udp_lib_exact_dif_match(struct net *net, struct sk_buff *skb) 135 { 136 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 137 if (!net->ipv4.sysctl_udp_l3mdev_accept && 138 skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) 139 return true; 140 #endif 141 return false; 142 } 143 144 static int udp_lib_lport_inuse(struct net *net, __u16 num, 145 const struct udp_hslot *hslot, 146 unsigned long *bitmap, 147 struct sock *sk, unsigned int log) 148 { 149 struct sock *sk2; 150 kuid_t uid = sock_i_uid(sk); 151 152 sk_for_each(sk2, &hslot->head) { 153 if (net_eq(sock_net(sk2), net) && 154 sk2 != sk && 155 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 156 (!sk2->sk_reuse || !sk->sk_reuse) && 157 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 158 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 159 inet_rcv_saddr_equal(sk, sk2, true)) { 160 if (sk2->sk_reuseport && sk->sk_reuseport && 161 !rcu_access_pointer(sk->sk_reuseport_cb) && 162 uid_eq(uid, sock_i_uid(sk2))) { 163 if (!bitmap) 164 return 0; 165 } else { 166 if (!bitmap) 167 return 1; 168 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 169 bitmap); 170 } 171 } 172 } 173 return 0; 174 } 175 176 /* 177 * Note: we still hold spinlock of primary hash chain, so no other writer 178 * can insert/delete a socket with local_port == num 179 */ 180 static int udp_lib_lport_inuse2(struct net *net, __u16 num, 181 struct udp_hslot *hslot2, 182 struct sock *sk) 183 { 184 struct sock *sk2; 185 kuid_t uid = sock_i_uid(sk); 186 int res = 0; 187 188 spin_lock(&hslot2->lock); 189 udp_portaddr_for_each_entry(sk2, &hslot2->head) { 190 if (net_eq(sock_net(sk2), net) && 191 sk2 != sk && 192 (udp_sk(sk2)->udp_port_hash == num) && 193 (!sk2->sk_reuse || !sk->sk_reuse) && 194 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 195 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 196 inet_rcv_saddr_equal(sk, sk2, true)) { 197 if (sk2->sk_reuseport && sk->sk_reuseport && 198 !rcu_access_pointer(sk->sk_reuseport_cb) && 199 uid_eq(uid, sock_i_uid(sk2))) { 200 res = 0; 201 } else { 202 res = 1; 203 } 204 break; 205 } 206 } 207 spin_unlock(&hslot2->lock); 208 return res; 209 } 210 211 static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot) 212 { 213 struct net *net = sock_net(sk); 214 kuid_t uid = sock_i_uid(sk); 215 struct sock *sk2; 216 217 sk_for_each(sk2, &hslot->head) { 218 if (net_eq(sock_net(sk2), net) && 219 sk2 != sk && 220 sk2->sk_family == sk->sk_family && 221 ipv6_only_sock(sk2) == ipv6_only_sock(sk) && 222 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) && 223 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 224 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && 225 inet_rcv_saddr_equal(sk, sk2, false)) { 226 return reuseport_add_sock(sk, sk2, 227 inet_rcv_saddr_any(sk)); 228 } 229 } 230 231 return reuseport_alloc(sk, inet_rcv_saddr_any(sk)); 232 } 233 234 /** 235 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 236 * 237 * @sk: socket struct in question 238 * @snum: port number to look up 239 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 240 * with NULL address 241 */ 242 int udp_lib_get_port(struct sock *sk, unsigned short snum, 243 unsigned int hash2_nulladdr) 244 { 245 struct udp_hslot *hslot, *hslot2; 246 struct udp_table *udptable = sk->sk_prot->h.udp_table; 247 int error = 1; 248 struct net *net = sock_net(sk); 249 250 if (!snum) { 251 int low, high, remaining; 252 unsigned int rand; 253 unsigned short first, last; 254 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 255 256 inet_get_local_port_range(net, &low, &high); 257 remaining = (high - low) + 1; 258 259 rand = prandom_u32(); 260 first = reciprocal_scale(rand, remaining) + low; 261 /* 262 * force rand to be an odd multiple of UDP_HTABLE_SIZE 263 */ 264 rand = (rand | 1) * (udptable->mask + 1); 265 last = first + udptable->mask + 1; 266 do { 267 hslot = udp_hashslot(udptable, net, first); 268 bitmap_zero(bitmap, PORTS_PER_CHAIN); 269 spin_lock_bh(&hslot->lock); 270 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 271 udptable->log); 272 273 snum = first; 274 /* 275 * Iterate on all possible values of snum for this hash. 276 * Using steps of an odd multiple of UDP_HTABLE_SIZE 277 * give us randomization and full range coverage. 278 */ 279 do { 280 if (low <= snum && snum <= high && 281 !test_bit(snum >> udptable->log, bitmap) && 282 !inet_is_local_reserved_port(net, snum)) 283 goto found; 284 snum += rand; 285 } while (snum != first); 286 spin_unlock_bh(&hslot->lock); 287 cond_resched(); 288 } while (++first != last); 289 goto fail; 290 } else { 291 hslot = udp_hashslot(udptable, net, snum); 292 spin_lock_bh(&hslot->lock); 293 if (hslot->count > 10) { 294 int exist; 295 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 296 297 slot2 &= udptable->mask; 298 hash2_nulladdr &= udptable->mask; 299 300 hslot2 = udp_hashslot2(udptable, slot2); 301 if (hslot->count < hslot2->count) 302 goto scan_primary_hash; 303 304 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk); 305 if (!exist && (hash2_nulladdr != slot2)) { 306 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 307 exist = udp_lib_lport_inuse2(net, snum, hslot2, 308 sk); 309 } 310 if (exist) 311 goto fail_unlock; 312 else 313 goto found; 314 } 315 scan_primary_hash: 316 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0)) 317 goto fail_unlock; 318 } 319 found: 320 inet_sk(sk)->inet_num = snum; 321 udp_sk(sk)->udp_port_hash = snum; 322 udp_sk(sk)->udp_portaddr_hash ^= snum; 323 if (sk_unhashed(sk)) { 324 if (sk->sk_reuseport && 325 udp_reuseport_add_sock(sk, hslot)) { 326 inet_sk(sk)->inet_num = 0; 327 udp_sk(sk)->udp_port_hash = 0; 328 udp_sk(sk)->udp_portaddr_hash ^= snum; 329 goto fail_unlock; 330 } 331 332 sk_add_node_rcu(sk, &hslot->head); 333 hslot->count++; 334 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 335 336 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 337 spin_lock(&hslot2->lock); 338 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 339 sk->sk_family == AF_INET6) 340 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node, 341 &hslot2->head); 342 else 343 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 344 &hslot2->head); 345 hslot2->count++; 346 spin_unlock(&hslot2->lock); 347 } 348 sock_set_flag(sk, SOCK_RCU_FREE); 349 error = 0; 350 fail_unlock: 351 spin_unlock_bh(&hslot->lock); 352 fail: 353 return error; 354 } 355 EXPORT_SYMBOL(udp_lib_get_port); 356 357 int udp_v4_get_port(struct sock *sk, unsigned short snum) 358 { 359 unsigned int hash2_nulladdr = 360 ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 361 unsigned int hash2_partial = 362 ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 363 364 /* precompute partial secondary hash */ 365 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 366 return udp_lib_get_port(sk, snum, hash2_nulladdr); 367 } 368 369 static int compute_score(struct sock *sk, struct net *net, 370 __be32 saddr, __be16 sport, 371 __be32 daddr, unsigned short hnum, 372 int dif, int sdif, bool exact_dif) 373 { 374 int score; 375 struct inet_sock *inet; 376 bool dev_match; 377 378 if (!net_eq(sock_net(sk), net) || 379 udp_sk(sk)->udp_port_hash != hnum || 380 ipv6_only_sock(sk)) 381 return -1; 382 383 if (sk->sk_rcv_saddr != daddr) 384 return -1; 385 386 score = (sk->sk_family == PF_INET) ? 2 : 1; 387 388 inet = inet_sk(sk); 389 if (inet->inet_daddr) { 390 if (inet->inet_daddr != saddr) 391 return -1; 392 score += 4; 393 } 394 395 if (inet->inet_dport) { 396 if (inet->inet_dport != sport) 397 return -1; 398 score += 4; 399 } 400 401 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, 402 dif, sdif); 403 if (!dev_match) 404 return -1; 405 score += 4; 406 407 if (sk->sk_incoming_cpu == raw_smp_processor_id()) 408 score++; 409 return score; 410 } 411 412 static u32 udp_ehashfn(const struct net *net, const __be32 laddr, 413 const __u16 lport, const __be32 faddr, 414 const __be16 fport) 415 { 416 static u32 udp_ehash_secret __read_mostly; 417 418 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); 419 420 return __inet_ehashfn(laddr, lport, faddr, fport, 421 udp_ehash_secret + net_hash_mix(net)); 422 } 423 424 /* called with rcu_read_lock() */ 425 static struct sock *udp4_lib_lookup2(struct net *net, 426 __be32 saddr, __be16 sport, 427 __be32 daddr, unsigned int hnum, 428 int dif, int sdif, bool exact_dif, 429 struct udp_hslot *hslot2, 430 struct sk_buff *skb) 431 { 432 struct sock *sk, *result; 433 int score, badness; 434 u32 hash = 0; 435 436 result = NULL; 437 badness = 0; 438 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 439 score = compute_score(sk, net, saddr, sport, 440 daddr, hnum, dif, sdif, exact_dif); 441 if (score > badness) { 442 if (sk->sk_reuseport) { 443 hash = udp_ehashfn(net, daddr, hnum, 444 saddr, sport); 445 result = reuseport_select_sock(sk, hash, skb, 446 sizeof(struct udphdr)); 447 if (result) 448 return result; 449 } 450 badness = score; 451 result = sk; 452 } 453 } 454 return result; 455 } 456 457 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 458 * harder than this. -DaveM 459 */ 460 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 461 __be16 sport, __be32 daddr, __be16 dport, int dif, 462 int sdif, struct udp_table *udptable, struct sk_buff *skb) 463 { 464 struct sock *result; 465 unsigned short hnum = ntohs(dport); 466 unsigned int hash2, slot2; 467 struct udp_hslot *hslot2; 468 bool exact_dif = udp_lib_exact_dif_match(net, skb); 469 470 hash2 = ipv4_portaddr_hash(net, daddr, hnum); 471 slot2 = hash2 & udptable->mask; 472 hslot2 = &udptable->hash2[slot2]; 473 474 result = udp4_lib_lookup2(net, saddr, sport, 475 daddr, hnum, dif, sdif, 476 exact_dif, hslot2, skb); 477 if (!result) { 478 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 479 slot2 = hash2 & udptable->mask; 480 hslot2 = &udptable->hash2[slot2]; 481 482 result = udp4_lib_lookup2(net, saddr, sport, 483 htonl(INADDR_ANY), hnum, dif, sdif, 484 exact_dif, hslot2, skb); 485 } 486 if (unlikely(IS_ERR(result))) 487 return NULL; 488 return result; 489 } 490 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 491 492 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 493 __be16 sport, __be16 dport, 494 struct udp_table *udptable) 495 { 496 const struct iphdr *iph = ip_hdr(skb); 497 498 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 499 iph->daddr, dport, inet_iif(skb), 500 inet_sdif(skb), udptable, skb); 501 } 502 503 struct sock *udp4_lib_lookup_skb(struct sk_buff *skb, 504 __be16 sport, __be16 dport) 505 { 506 return __udp4_lib_lookup_skb(skb, sport, dport, &udp_table); 507 } 508 EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb); 509 510 /* Must be called under rcu_read_lock(). 511 * Does increment socket refcount. 512 */ 513 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4) 514 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 515 __be32 daddr, __be16 dport, int dif) 516 { 517 struct sock *sk; 518 519 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport, 520 dif, 0, &udp_table, NULL); 521 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) 522 sk = NULL; 523 return sk; 524 } 525 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 526 #endif 527 528 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, 529 __be16 loc_port, __be32 loc_addr, 530 __be16 rmt_port, __be32 rmt_addr, 531 int dif, int sdif, unsigned short hnum) 532 { 533 struct inet_sock *inet = inet_sk(sk); 534 535 if (!net_eq(sock_net(sk), net) || 536 udp_sk(sk)->udp_port_hash != hnum || 537 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 538 (inet->inet_dport != rmt_port && inet->inet_dport) || 539 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) || 540 ipv6_only_sock(sk) || 541 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif && 542 sk->sk_bound_dev_if != sdif)) 543 return false; 544 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif)) 545 return false; 546 return true; 547 } 548 549 DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key); 550 void udp_encap_enable(void) 551 { 552 static_branch_inc(&udp_encap_needed_key); 553 } 554 EXPORT_SYMBOL(udp_encap_enable); 555 556 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go 557 * through error handlers in encapsulations looking for a match. 558 */ 559 static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info) 560 { 561 int i; 562 563 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { 564 int (*handler)(struct sk_buff *skb, u32 info); 565 const struct ip_tunnel_encap_ops *encap; 566 567 encap = rcu_dereference(iptun_encaps[i]); 568 if (!encap) 569 continue; 570 handler = encap->err_handler; 571 if (handler && !handler(skb, info)) 572 return 0; 573 } 574 575 return -ENOENT; 576 } 577 578 /* Try to match ICMP errors to UDP tunnels by looking up a socket without 579 * reversing source and destination port: this will match tunnels that force the 580 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that 581 * lwtunnels might actually break this assumption by being configured with 582 * different destination ports on endpoints, in this case we won't be able to 583 * trace ICMP messages back to them. 584 * 585 * If this doesn't match any socket, probe tunnels with arbitrary destination 586 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port 587 * we've sent packets to won't necessarily match the local destination port. 588 * 589 * Then ask the tunnel implementation to match the error against a valid 590 * association. 591 * 592 * Return an error if we can't find a match, the socket if we need further 593 * processing, zero otherwise. 594 */ 595 static struct sock *__udp4_lib_err_encap(struct net *net, 596 const struct iphdr *iph, 597 struct udphdr *uh, 598 struct udp_table *udptable, 599 struct sk_buff *skb, u32 info) 600 { 601 int network_offset, transport_offset; 602 struct sock *sk; 603 604 network_offset = skb_network_offset(skb); 605 transport_offset = skb_transport_offset(skb); 606 607 /* Network header needs to point to the outer IPv4 header inside ICMP */ 608 skb_reset_network_header(skb); 609 610 /* Transport header needs to point to the UDP header */ 611 skb_set_transport_header(skb, iph->ihl << 2); 612 613 sk = __udp4_lib_lookup(net, iph->daddr, uh->source, 614 iph->saddr, uh->dest, skb->dev->ifindex, 0, 615 udptable, NULL); 616 if (sk) { 617 int (*lookup)(struct sock *sk, struct sk_buff *skb); 618 struct udp_sock *up = udp_sk(sk); 619 620 lookup = READ_ONCE(up->encap_err_lookup); 621 if (!lookup || lookup(sk, skb)) 622 sk = NULL; 623 } 624 625 if (!sk) 626 sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info)); 627 628 skb_set_transport_header(skb, transport_offset); 629 skb_set_network_header(skb, network_offset); 630 631 return sk; 632 } 633 634 /* 635 * This routine is called by the ICMP module when it gets some 636 * sort of error condition. If err < 0 then the socket should 637 * be closed and the error returned to the user. If err > 0 638 * it's just the icmp type << 8 | icmp code. 639 * Header points to the ip header of the error packet. We move 640 * on past this. Then (as it used to claim before adjustment) 641 * header points to the first 8 bytes of the udp header. We need 642 * to find the appropriate port. 643 */ 644 645 int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 646 { 647 struct inet_sock *inet; 648 const struct iphdr *iph = (const struct iphdr *)skb->data; 649 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 650 const int type = icmp_hdr(skb)->type; 651 const int code = icmp_hdr(skb)->code; 652 bool tunnel = false; 653 struct sock *sk; 654 int harderr; 655 int err; 656 struct net *net = dev_net(skb->dev); 657 658 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 659 iph->saddr, uh->source, skb->dev->ifindex, 660 inet_sdif(skb), udptable, NULL); 661 if (!sk) { 662 /* No socket for error: try tunnels before discarding */ 663 sk = ERR_PTR(-ENOENT); 664 if (static_branch_unlikely(&udp_encap_needed_key)) { 665 sk = __udp4_lib_err_encap(net, iph, uh, udptable, skb, 666 info); 667 if (!sk) 668 return 0; 669 } 670 671 if (IS_ERR(sk)) { 672 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); 673 return PTR_ERR(sk); 674 } 675 676 tunnel = true; 677 } 678 679 err = 0; 680 harderr = 0; 681 inet = inet_sk(sk); 682 683 switch (type) { 684 default: 685 case ICMP_TIME_EXCEEDED: 686 err = EHOSTUNREACH; 687 break; 688 case ICMP_SOURCE_QUENCH: 689 goto out; 690 case ICMP_PARAMETERPROB: 691 err = EPROTO; 692 harderr = 1; 693 break; 694 case ICMP_DEST_UNREACH: 695 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 696 ipv4_sk_update_pmtu(skb, sk, info); 697 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 698 err = EMSGSIZE; 699 harderr = 1; 700 break; 701 } 702 goto out; 703 } 704 err = EHOSTUNREACH; 705 if (code <= NR_ICMP_UNREACH) { 706 harderr = icmp_err_convert[code].fatal; 707 err = icmp_err_convert[code].errno; 708 } 709 break; 710 case ICMP_REDIRECT: 711 ipv4_sk_redirect(skb, sk); 712 goto out; 713 } 714 715 /* 716 * RFC1122: OK. Passes ICMP errors back to application, as per 717 * 4.1.3.3. 718 */ 719 if (tunnel) { 720 /* ...not for tunnels though: we don't have a sending socket */ 721 goto out; 722 } 723 if (!inet->recverr) { 724 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 725 goto out; 726 } else 727 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 728 729 sk->sk_err = err; 730 sk->sk_error_report(sk); 731 out: 732 return 0; 733 } 734 735 int udp_err(struct sk_buff *skb, u32 info) 736 { 737 return __udp4_lib_err(skb, info, &udp_table); 738 } 739 740 /* 741 * Throw away all pending data and cancel the corking. Socket is locked. 742 */ 743 void udp_flush_pending_frames(struct sock *sk) 744 { 745 struct udp_sock *up = udp_sk(sk); 746 747 if (up->pending) { 748 up->len = 0; 749 up->pending = 0; 750 ip_flush_pending_frames(sk); 751 } 752 } 753 EXPORT_SYMBOL(udp_flush_pending_frames); 754 755 /** 756 * udp4_hwcsum - handle outgoing HW checksumming 757 * @skb: sk_buff containing the filled-in UDP header 758 * (checksum field must be zeroed out) 759 * @src: source IP address 760 * @dst: destination IP address 761 */ 762 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 763 { 764 struct udphdr *uh = udp_hdr(skb); 765 int offset = skb_transport_offset(skb); 766 int len = skb->len - offset; 767 int hlen = len; 768 __wsum csum = 0; 769 770 if (!skb_has_frag_list(skb)) { 771 /* 772 * Only one fragment on the socket. 773 */ 774 skb->csum_start = skb_transport_header(skb) - skb->head; 775 skb->csum_offset = offsetof(struct udphdr, check); 776 uh->check = ~csum_tcpudp_magic(src, dst, len, 777 IPPROTO_UDP, 0); 778 } else { 779 struct sk_buff *frags; 780 781 /* 782 * HW-checksum won't work as there are two or more 783 * fragments on the socket so that all csums of sk_buffs 784 * should be together 785 */ 786 skb_walk_frags(skb, frags) { 787 csum = csum_add(csum, frags->csum); 788 hlen -= frags->len; 789 } 790 791 csum = skb_checksum(skb, offset, hlen, csum); 792 skb->ip_summed = CHECKSUM_NONE; 793 794 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 795 if (uh->check == 0) 796 uh->check = CSUM_MANGLED_0; 797 } 798 } 799 EXPORT_SYMBOL_GPL(udp4_hwcsum); 800 801 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended 802 * for the simple case like when setting the checksum for a UDP tunnel. 803 */ 804 void udp_set_csum(bool nocheck, struct sk_buff *skb, 805 __be32 saddr, __be32 daddr, int len) 806 { 807 struct udphdr *uh = udp_hdr(skb); 808 809 if (nocheck) { 810 uh->check = 0; 811 } else if (skb_is_gso(skb)) { 812 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 813 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { 814 uh->check = 0; 815 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb)); 816 if (uh->check == 0) 817 uh->check = CSUM_MANGLED_0; 818 } else { 819 skb->ip_summed = CHECKSUM_PARTIAL; 820 skb->csum_start = skb_transport_header(skb) - skb->head; 821 skb->csum_offset = offsetof(struct udphdr, check); 822 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 823 } 824 } 825 EXPORT_SYMBOL(udp_set_csum); 826 827 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4, 828 struct inet_cork *cork) 829 { 830 struct sock *sk = skb->sk; 831 struct inet_sock *inet = inet_sk(sk); 832 struct udphdr *uh; 833 int err = 0; 834 int is_udplite = IS_UDPLITE(sk); 835 int offset = skb_transport_offset(skb); 836 int len = skb->len - offset; 837 __wsum csum = 0; 838 839 /* 840 * Create a UDP header 841 */ 842 uh = udp_hdr(skb); 843 uh->source = inet->inet_sport; 844 uh->dest = fl4->fl4_dport; 845 uh->len = htons(len); 846 uh->check = 0; 847 848 if (cork->gso_size) { 849 const int hlen = skb_network_header_len(skb) + 850 sizeof(struct udphdr); 851 852 if (hlen + cork->gso_size > cork->fragsize) { 853 kfree_skb(skb); 854 return -EINVAL; 855 } 856 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) { 857 kfree_skb(skb); 858 return -EINVAL; 859 } 860 if (sk->sk_no_check_tx) { 861 kfree_skb(skb); 862 return -EINVAL; 863 } 864 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || 865 dst_xfrm(skb_dst(skb))) { 866 kfree_skb(skb); 867 return -EIO; 868 } 869 870 skb_shinfo(skb)->gso_size = cork->gso_size; 871 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; 872 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(len - sizeof(uh), 873 cork->gso_size); 874 goto csum_partial; 875 } 876 877 if (is_udplite) /* UDP-Lite */ 878 csum = udplite_csum(skb); 879 880 else if (sk->sk_no_check_tx) { /* UDP csum off */ 881 882 skb->ip_summed = CHECKSUM_NONE; 883 goto send; 884 885 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 886 csum_partial: 887 888 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 889 goto send; 890 891 } else 892 csum = udp_csum(skb); 893 894 /* add protocol-dependent pseudo-header */ 895 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 896 sk->sk_protocol, csum); 897 if (uh->check == 0) 898 uh->check = CSUM_MANGLED_0; 899 900 send: 901 err = ip_send_skb(sock_net(sk), skb); 902 if (err) { 903 if (err == -ENOBUFS && !inet->recverr) { 904 UDP_INC_STATS(sock_net(sk), 905 UDP_MIB_SNDBUFERRORS, is_udplite); 906 err = 0; 907 } 908 } else 909 UDP_INC_STATS(sock_net(sk), 910 UDP_MIB_OUTDATAGRAMS, is_udplite); 911 return err; 912 } 913 914 /* 915 * Push out all pending data as one UDP datagram. Socket is locked. 916 */ 917 int udp_push_pending_frames(struct sock *sk) 918 { 919 struct udp_sock *up = udp_sk(sk); 920 struct inet_sock *inet = inet_sk(sk); 921 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 922 struct sk_buff *skb; 923 int err = 0; 924 925 skb = ip_finish_skb(sk, fl4); 926 if (!skb) 927 goto out; 928 929 err = udp_send_skb(skb, fl4, &inet->cork.base); 930 931 out: 932 up->len = 0; 933 up->pending = 0; 934 return err; 935 } 936 EXPORT_SYMBOL(udp_push_pending_frames); 937 938 static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size) 939 { 940 switch (cmsg->cmsg_type) { 941 case UDP_SEGMENT: 942 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16))) 943 return -EINVAL; 944 *gso_size = *(__u16 *)CMSG_DATA(cmsg); 945 return 0; 946 default: 947 return -EINVAL; 948 } 949 } 950 951 int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size) 952 { 953 struct cmsghdr *cmsg; 954 bool need_ip = false; 955 int err; 956 957 for_each_cmsghdr(cmsg, msg) { 958 if (!CMSG_OK(msg, cmsg)) 959 return -EINVAL; 960 961 if (cmsg->cmsg_level != SOL_UDP) { 962 need_ip = true; 963 continue; 964 } 965 966 err = __udp_cmsg_send(cmsg, gso_size); 967 if (err) 968 return err; 969 } 970 971 return need_ip; 972 } 973 EXPORT_SYMBOL_GPL(udp_cmsg_send); 974 975 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 976 { 977 struct inet_sock *inet = inet_sk(sk); 978 struct udp_sock *up = udp_sk(sk); 979 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 980 struct flowi4 fl4_stack; 981 struct flowi4 *fl4; 982 int ulen = len; 983 struct ipcm_cookie ipc; 984 struct rtable *rt = NULL; 985 int free = 0; 986 int connected = 0; 987 __be32 daddr, faddr, saddr; 988 __be16 dport; 989 u8 tos; 990 int err, is_udplite = IS_UDPLITE(sk); 991 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 992 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 993 struct sk_buff *skb; 994 struct ip_options_data opt_copy; 995 996 if (len > 0xFFFF) 997 return -EMSGSIZE; 998 999 /* 1000 * Check the flags. 1001 */ 1002 1003 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 1004 return -EOPNOTSUPP; 1005 1006 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 1007 1008 fl4 = &inet->cork.fl.u.ip4; 1009 if (up->pending) { 1010 /* 1011 * There are pending frames. 1012 * The socket lock must be held while it's corked. 1013 */ 1014 lock_sock(sk); 1015 if (likely(up->pending)) { 1016 if (unlikely(up->pending != AF_INET)) { 1017 release_sock(sk); 1018 return -EINVAL; 1019 } 1020 goto do_append_data; 1021 } 1022 release_sock(sk); 1023 } 1024 ulen += sizeof(struct udphdr); 1025 1026 /* 1027 * Get and verify the address. 1028 */ 1029 if (usin) { 1030 if (msg->msg_namelen < sizeof(*usin)) 1031 return -EINVAL; 1032 if (usin->sin_family != AF_INET) { 1033 if (usin->sin_family != AF_UNSPEC) 1034 return -EAFNOSUPPORT; 1035 } 1036 1037 daddr = usin->sin_addr.s_addr; 1038 dport = usin->sin_port; 1039 if (dport == 0) 1040 return -EINVAL; 1041 } else { 1042 if (sk->sk_state != TCP_ESTABLISHED) 1043 return -EDESTADDRREQ; 1044 daddr = inet->inet_daddr; 1045 dport = inet->inet_dport; 1046 /* Open fast path for connected socket. 1047 Route will not be used, if at least one option is set. 1048 */ 1049 connected = 1; 1050 } 1051 1052 ipcm_init_sk(&ipc, inet); 1053 ipc.gso_size = up->gso_size; 1054 1055 if (msg->msg_controllen) { 1056 err = udp_cmsg_send(sk, msg, &ipc.gso_size); 1057 if (err > 0) 1058 err = ip_cmsg_send(sk, msg, &ipc, 1059 sk->sk_family == AF_INET6); 1060 if (unlikely(err < 0)) { 1061 kfree(ipc.opt); 1062 return err; 1063 } 1064 if (ipc.opt) 1065 free = 1; 1066 connected = 0; 1067 } 1068 if (!ipc.opt) { 1069 struct ip_options_rcu *inet_opt; 1070 1071 rcu_read_lock(); 1072 inet_opt = rcu_dereference(inet->inet_opt); 1073 if (inet_opt) { 1074 memcpy(&opt_copy, inet_opt, 1075 sizeof(*inet_opt) + inet_opt->opt.optlen); 1076 ipc.opt = &opt_copy.opt; 1077 } 1078 rcu_read_unlock(); 1079 } 1080 1081 if (cgroup_bpf_enabled && !connected) { 1082 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, 1083 (struct sockaddr *)usin, &ipc.addr); 1084 if (err) 1085 goto out_free; 1086 if (usin) { 1087 if (usin->sin_port == 0) { 1088 /* BPF program set invalid port. Reject it. */ 1089 err = -EINVAL; 1090 goto out_free; 1091 } 1092 daddr = usin->sin_addr.s_addr; 1093 dport = usin->sin_port; 1094 } 1095 } 1096 1097 saddr = ipc.addr; 1098 ipc.addr = faddr = daddr; 1099 1100 if (ipc.opt && ipc.opt->opt.srr) { 1101 if (!daddr) { 1102 err = -EINVAL; 1103 goto out_free; 1104 } 1105 faddr = ipc.opt->opt.faddr; 1106 connected = 0; 1107 } 1108 tos = get_rttos(&ipc, inet); 1109 if (sock_flag(sk, SOCK_LOCALROUTE) || 1110 (msg->msg_flags & MSG_DONTROUTE) || 1111 (ipc.opt && ipc.opt->opt.is_strictroute)) { 1112 tos |= RTO_ONLINK; 1113 connected = 0; 1114 } 1115 1116 if (ipv4_is_multicast(daddr)) { 1117 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 1118 ipc.oif = inet->mc_index; 1119 if (!saddr) 1120 saddr = inet->mc_addr; 1121 connected = 0; 1122 } else if (!ipc.oif) { 1123 ipc.oif = inet->uc_index; 1124 } else if (ipv4_is_lbcast(daddr) && inet->uc_index) { 1125 /* oif is set, packet is to local broadcast and 1126 * and uc_index is set. oif is most likely set 1127 * by sk_bound_dev_if. If uc_index != oif check if the 1128 * oif is an L3 master and uc_index is an L3 slave. 1129 * If so, we want to allow the send using the uc_index. 1130 */ 1131 if (ipc.oif != inet->uc_index && 1132 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk), 1133 inet->uc_index)) { 1134 ipc.oif = inet->uc_index; 1135 } 1136 } 1137 1138 if (connected) 1139 rt = (struct rtable *)sk_dst_check(sk, 0); 1140 1141 if (!rt) { 1142 struct net *net = sock_net(sk); 1143 __u8 flow_flags = inet_sk_flowi_flags(sk); 1144 1145 fl4 = &fl4_stack; 1146 1147 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, 1148 RT_SCOPE_UNIVERSE, sk->sk_protocol, 1149 flow_flags, 1150 faddr, saddr, dport, inet->inet_sport, 1151 sk->sk_uid); 1152 1153 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 1154 rt = ip_route_output_flow(net, fl4, sk); 1155 if (IS_ERR(rt)) { 1156 err = PTR_ERR(rt); 1157 rt = NULL; 1158 if (err == -ENETUNREACH) 1159 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 1160 goto out; 1161 } 1162 1163 err = -EACCES; 1164 if ((rt->rt_flags & RTCF_BROADCAST) && 1165 !sock_flag(sk, SOCK_BROADCAST)) 1166 goto out; 1167 if (connected) 1168 sk_dst_set(sk, dst_clone(&rt->dst)); 1169 } 1170 1171 if (msg->msg_flags&MSG_CONFIRM) 1172 goto do_confirm; 1173 back_from_confirm: 1174 1175 saddr = fl4->saddr; 1176 if (!ipc.addr) 1177 daddr = ipc.addr = fl4->daddr; 1178 1179 /* Lockless fast path for the non-corking case. */ 1180 if (!corkreq) { 1181 struct inet_cork cork; 1182 1183 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen, 1184 sizeof(struct udphdr), &ipc, &rt, 1185 &cork, msg->msg_flags); 1186 err = PTR_ERR(skb); 1187 if (!IS_ERR_OR_NULL(skb)) 1188 err = udp_send_skb(skb, fl4, &cork); 1189 goto out; 1190 } 1191 1192 lock_sock(sk); 1193 if (unlikely(up->pending)) { 1194 /* The socket is already corked while preparing it. */ 1195 /* ... which is an evident application bug. --ANK */ 1196 release_sock(sk); 1197 1198 net_dbg_ratelimited("socket already corked\n"); 1199 err = -EINVAL; 1200 goto out; 1201 } 1202 /* 1203 * Now cork the socket to pend data. 1204 */ 1205 fl4 = &inet->cork.fl.u.ip4; 1206 fl4->daddr = daddr; 1207 fl4->saddr = saddr; 1208 fl4->fl4_dport = dport; 1209 fl4->fl4_sport = inet->inet_sport; 1210 up->pending = AF_INET; 1211 1212 do_append_data: 1213 up->len += ulen; 1214 err = ip_append_data(sk, fl4, getfrag, msg, ulen, 1215 sizeof(struct udphdr), &ipc, &rt, 1216 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1217 if (err) 1218 udp_flush_pending_frames(sk); 1219 else if (!corkreq) 1220 err = udp_push_pending_frames(sk); 1221 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1222 up->pending = 0; 1223 release_sock(sk); 1224 1225 out: 1226 ip_rt_put(rt); 1227 out_free: 1228 if (free) 1229 kfree(ipc.opt); 1230 if (!err) 1231 return len; 1232 /* 1233 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1234 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1235 * we don't have a good statistic (IpOutDiscards but it can be too many 1236 * things). We could add another new stat but at least for now that 1237 * seems like overkill. 1238 */ 1239 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1240 UDP_INC_STATS(sock_net(sk), 1241 UDP_MIB_SNDBUFERRORS, is_udplite); 1242 } 1243 return err; 1244 1245 do_confirm: 1246 if (msg->msg_flags & MSG_PROBE) 1247 dst_confirm_neigh(&rt->dst, &fl4->daddr); 1248 if (!(msg->msg_flags&MSG_PROBE) || len) 1249 goto back_from_confirm; 1250 err = 0; 1251 goto out; 1252 } 1253 EXPORT_SYMBOL(udp_sendmsg); 1254 1255 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1256 size_t size, int flags) 1257 { 1258 struct inet_sock *inet = inet_sk(sk); 1259 struct udp_sock *up = udp_sk(sk); 1260 int ret; 1261 1262 if (flags & MSG_SENDPAGE_NOTLAST) 1263 flags |= MSG_MORE; 1264 1265 if (!up->pending) { 1266 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1267 1268 /* Call udp_sendmsg to specify destination address which 1269 * sendpage interface can't pass. 1270 * This will succeed only when the socket is connected. 1271 */ 1272 ret = udp_sendmsg(sk, &msg, 0); 1273 if (ret < 0) 1274 return ret; 1275 } 1276 1277 lock_sock(sk); 1278 1279 if (unlikely(!up->pending)) { 1280 release_sock(sk); 1281 1282 net_dbg_ratelimited("cork failed\n"); 1283 return -EINVAL; 1284 } 1285 1286 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1287 page, offset, size, flags); 1288 if (ret == -EOPNOTSUPP) { 1289 release_sock(sk); 1290 return sock_no_sendpage(sk->sk_socket, page, offset, 1291 size, flags); 1292 } 1293 if (ret < 0) { 1294 udp_flush_pending_frames(sk); 1295 goto out; 1296 } 1297 1298 up->len += size; 1299 if (!(up->corkflag || (flags&MSG_MORE))) 1300 ret = udp_push_pending_frames(sk); 1301 if (!ret) 1302 ret = size; 1303 out: 1304 release_sock(sk); 1305 return ret; 1306 } 1307 1308 #define UDP_SKB_IS_STATELESS 0x80000000 1309 1310 static void udp_set_dev_scratch(struct sk_buff *skb) 1311 { 1312 struct udp_dev_scratch *scratch = udp_skb_scratch(skb); 1313 1314 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long)); 1315 scratch->_tsize_state = skb->truesize; 1316 #if BITS_PER_LONG == 64 1317 scratch->len = skb->len; 1318 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb); 1319 scratch->is_linear = !skb_is_nonlinear(skb); 1320 #endif 1321 /* all head states execept sp (dst, sk, nf) are always cleared by 1322 * udp_rcv() and we need to preserve secpath, if present, to eventually 1323 * process IP_CMSG_PASSSEC at recvmsg() time 1324 */ 1325 if (likely(!skb_sec_path(skb))) 1326 scratch->_tsize_state |= UDP_SKB_IS_STATELESS; 1327 } 1328 1329 static int udp_skb_truesize(struct sk_buff *skb) 1330 { 1331 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS; 1332 } 1333 1334 static bool udp_skb_has_head_state(struct sk_buff *skb) 1335 { 1336 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS); 1337 } 1338 1339 /* fully reclaim rmem/fwd memory allocated for skb */ 1340 static void udp_rmem_release(struct sock *sk, int size, int partial, 1341 bool rx_queue_lock_held) 1342 { 1343 struct udp_sock *up = udp_sk(sk); 1344 struct sk_buff_head *sk_queue; 1345 int amt; 1346 1347 if (likely(partial)) { 1348 up->forward_deficit += size; 1349 size = up->forward_deficit; 1350 if (size < (sk->sk_rcvbuf >> 2)) 1351 return; 1352 } else { 1353 size += up->forward_deficit; 1354 } 1355 up->forward_deficit = 0; 1356 1357 /* acquire the sk_receive_queue for fwd allocated memory scheduling, 1358 * if the called don't held it already 1359 */ 1360 sk_queue = &sk->sk_receive_queue; 1361 if (!rx_queue_lock_held) 1362 spin_lock(&sk_queue->lock); 1363 1364 1365 sk->sk_forward_alloc += size; 1366 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1); 1367 sk->sk_forward_alloc -= amt; 1368 1369 if (amt) 1370 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT); 1371 1372 atomic_sub(size, &sk->sk_rmem_alloc); 1373 1374 /* this can save us from acquiring the rx queue lock on next receive */ 1375 skb_queue_splice_tail_init(sk_queue, &up->reader_queue); 1376 1377 if (!rx_queue_lock_held) 1378 spin_unlock(&sk_queue->lock); 1379 } 1380 1381 /* Note: called with reader_queue.lock held. 1382 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch 1383 * This avoids a cache line miss while receive_queue lock is held. 1384 * Look at __udp_enqueue_schedule_skb() to find where this copy is done. 1385 */ 1386 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb) 1387 { 1388 prefetch(&skb->data); 1389 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false); 1390 } 1391 EXPORT_SYMBOL(udp_skb_destructor); 1392 1393 /* as above, but the caller held the rx queue lock, too */ 1394 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb) 1395 { 1396 prefetch(&skb->data); 1397 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true); 1398 } 1399 1400 /* Idea of busylocks is to let producers grab an extra spinlock 1401 * to relieve pressure on the receive_queue spinlock shared by consumer. 1402 * Under flood, this means that only one producer can be in line 1403 * trying to acquire the receive_queue spinlock. 1404 * These busylock can be allocated on a per cpu manner, instead of a 1405 * per socket one (that would consume a cache line per socket) 1406 */ 1407 static int udp_busylocks_log __read_mostly; 1408 static spinlock_t *udp_busylocks __read_mostly; 1409 1410 static spinlock_t *busylock_acquire(void *ptr) 1411 { 1412 spinlock_t *busy; 1413 1414 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log); 1415 spin_lock(busy); 1416 return busy; 1417 } 1418 1419 static void busylock_release(spinlock_t *busy) 1420 { 1421 if (busy) 1422 spin_unlock(busy); 1423 } 1424 1425 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) 1426 { 1427 struct sk_buff_head *list = &sk->sk_receive_queue; 1428 int rmem, delta, amt, err = -ENOMEM; 1429 spinlock_t *busy = NULL; 1430 int size; 1431 1432 /* try to avoid the costly atomic add/sub pair when the receive 1433 * queue is full; always allow at least a packet 1434 */ 1435 rmem = atomic_read(&sk->sk_rmem_alloc); 1436 if (rmem > sk->sk_rcvbuf) 1437 goto drop; 1438 1439 /* Under mem pressure, it might be helpful to help udp_recvmsg() 1440 * having linear skbs : 1441 * - Reduce memory overhead and thus increase receive queue capacity 1442 * - Less cache line misses at copyout() time 1443 * - Less work at consume_skb() (less alien page frag freeing) 1444 */ 1445 if (rmem > (sk->sk_rcvbuf >> 1)) { 1446 skb_condense(skb); 1447 1448 busy = busylock_acquire(sk); 1449 } 1450 size = skb->truesize; 1451 udp_set_dev_scratch(skb); 1452 1453 /* we drop only if the receive buf is full and the receive 1454 * queue contains some other skb 1455 */ 1456 rmem = atomic_add_return(size, &sk->sk_rmem_alloc); 1457 if (rmem > (size + sk->sk_rcvbuf)) 1458 goto uncharge_drop; 1459 1460 spin_lock(&list->lock); 1461 if (size >= sk->sk_forward_alloc) { 1462 amt = sk_mem_pages(size); 1463 delta = amt << SK_MEM_QUANTUM_SHIFT; 1464 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) { 1465 err = -ENOBUFS; 1466 spin_unlock(&list->lock); 1467 goto uncharge_drop; 1468 } 1469 1470 sk->sk_forward_alloc += delta; 1471 } 1472 1473 sk->sk_forward_alloc -= size; 1474 1475 /* no need to setup a destructor, we will explicitly release the 1476 * forward allocated memory on dequeue 1477 */ 1478 sock_skb_set_dropcount(sk, skb); 1479 1480 __skb_queue_tail(list, skb); 1481 spin_unlock(&list->lock); 1482 1483 if (!sock_flag(sk, SOCK_DEAD)) 1484 sk->sk_data_ready(sk); 1485 1486 busylock_release(busy); 1487 return 0; 1488 1489 uncharge_drop: 1490 atomic_sub(skb->truesize, &sk->sk_rmem_alloc); 1491 1492 drop: 1493 atomic_inc(&sk->sk_drops); 1494 busylock_release(busy); 1495 return err; 1496 } 1497 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb); 1498 1499 void udp_destruct_sock(struct sock *sk) 1500 { 1501 /* reclaim completely the forward allocated memory */ 1502 struct udp_sock *up = udp_sk(sk); 1503 unsigned int total = 0; 1504 struct sk_buff *skb; 1505 1506 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue); 1507 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) { 1508 total += skb->truesize; 1509 kfree_skb(skb); 1510 } 1511 udp_rmem_release(sk, total, 0, true); 1512 1513 inet_sock_destruct(sk); 1514 } 1515 EXPORT_SYMBOL_GPL(udp_destruct_sock); 1516 1517 int udp_init_sock(struct sock *sk) 1518 { 1519 skb_queue_head_init(&udp_sk(sk)->reader_queue); 1520 sk->sk_destruct = udp_destruct_sock; 1521 return 0; 1522 } 1523 EXPORT_SYMBOL_GPL(udp_init_sock); 1524 1525 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) 1526 { 1527 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) { 1528 bool slow = lock_sock_fast(sk); 1529 1530 sk_peek_offset_bwd(sk, len); 1531 unlock_sock_fast(sk, slow); 1532 } 1533 1534 if (!skb_unref(skb)) 1535 return; 1536 1537 /* In the more common cases we cleared the head states previously, 1538 * see __udp_queue_rcv_skb(). 1539 */ 1540 if (unlikely(udp_skb_has_head_state(skb))) 1541 skb_release_head_state(skb); 1542 __consume_stateless_skb(skb); 1543 } 1544 EXPORT_SYMBOL_GPL(skb_consume_udp); 1545 1546 static struct sk_buff *__first_packet_length(struct sock *sk, 1547 struct sk_buff_head *rcvq, 1548 int *total) 1549 { 1550 struct sk_buff *skb; 1551 1552 while ((skb = skb_peek(rcvq)) != NULL) { 1553 if (udp_lib_checksum_complete(skb)) { 1554 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, 1555 IS_UDPLITE(sk)); 1556 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, 1557 IS_UDPLITE(sk)); 1558 atomic_inc(&sk->sk_drops); 1559 __skb_unlink(skb, rcvq); 1560 *total += skb->truesize; 1561 kfree_skb(skb); 1562 } else { 1563 /* the csum related bits could be changed, refresh 1564 * the scratch area 1565 */ 1566 udp_set_dev_scratch(skb); 1567 break; 1568 } 1569 } 1570 return skb; 1571 } 1572 1573 /** 1574 * first_packet_length - return length of first packet in receive queue 1575 * @sk: socket 1576 * 1577 * Drops all bad checksum frames, until a valid one is found. 1578 * Returns the length of found skb, or -1 if none is found. 1579 */ 1580 static int first_packet_length(struct sock *sk) 1581 { 1582 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue; 1583 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1584 struct sk_buff *skb; 1585 int total = 0; 1586 int res; 1587 1588 spin_lock_bh(&rcvq->lock); 1589 skb = __first_packet_length(sk, rcvq, &total); 1590 if (!skb && !skb_queue_empty(sk_queue)) { 1591 spin_lock(&sk_queue->lock); 1592 skb_queue_splice_tail_init(sk_queue, rcvq); 1593 spin_unlock(&sk_queue->lock); 1594 1595 skb = __first_packet_length(sk, rcvq, &total); 1596 } 1597 res = skb ? skb->len : -1; 1598 if (total) 1599 udp_rmem_release(sk, total, 1, false); 1600 spin_unlock_bh(&rcvq->lock); 1601 return res; 1602 } 1603 1604 /* 1605 * IOCTL requests applicable to the UDP protocol 1606 */ 1607 1608 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1609 { 1610 switch (cmd) { 1611 case SIOCOUTQ: 1612 { 1613 int amount = sk_wmem_alloc_get(sk); 1614 1615 return put_user(amount, (int __user *)arg); 1616 } 1617 1618 case SIOCINQ: 1619 { 1620 int amount = max_t(int, 0, first_packet_length(sk)); 1621 1622 return put_user(amount, (int __user *)arg); 1623 } 1624 1625 default: 1626 return -ENOIOCTLCMD; 1627 } 1628 1629 return 0; 1630 } 1631 EXPORT_SYMBOL(udp_ioctl); 1632 1633 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, 1634 int noblock, int *peeked, int *off, int *err) 1635 { 1636 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1637 struct sk_buff_head *queue; 1638 struct sk_buff *last; 1639 long timeo; 1640 int error; 1641 1642 queue = &udp_sk(sk)->reader_queue; 1643 flags |= noblock ? MSG_DONTWAIT : 0; 1644 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 1645 do { 1646 struct sk_buff *skb; 1647 1648 error = sock_error(sk); 1649 if (error) 1650 break; 1651 1652 error = -EAGAIN; 1653 *peeked = 0; 1654 do { 1655 spin_lock_bh(&queue->lock); 1656 skb = __skb_try_recv_from_queue(sk, queue, flags, 1657 udp_skb_destructor, 1658 peeked, off, err, 1659 &last); 1660 if (skb) { 1661 spin_unlock_bh(&queue->lock); 1662 return skb; 1663 } 1664 1665 if (skb_queue_empty(sk_queue)) { 1666 spin_unlock_bh(&queue->lock); 1667 goto busy_check; 1668 } 1669 1670 /* refill the reader queue and walk it again 1671 * keep both queues locked to avoid re-acquiring 1672 * the sk_receive_queue lock if fwd memory scheduling 1673 * is needed. 1674 */ 1675 spin_lock(&sk_queue->lock); 1676 skb_queue_splice_tail_init(sk_queue, queue); 1677 1678 skb = __skb_try_recv_from_queue(sk, queue, flags, 1679 udp_skb_dtor_locked, 1680 peeked, off, err, 1681 &last); 1682 spin_unlock(&sk_queue->lock); 1683 spin_unlock_bh(&queue->lock); 1684 if (skb) 1685 return skb; 1686 1687 busy_check: 1688 if (!sk_can_busy_loop(sk)) 1689 break; 1690 1691 sk_busy_loop(sk, flags & MSG_DONTWAIT); 1692 } while (!skb_queue_empty(sk_queue)); 1693 1694 /* sk_queue is empty, reader_queue may contain peeked packets */ 1695 } while (timeo && 1696 !__skb_wait_for_more_packets(sk, &error, &timeo, 1697 (struct sk_buff *)sk_queue)); 1698 1699 *err = error; 1700 return NULL; 1701 } 1702 EXPORT_SYMBOL(__skb_recv_udp); 1703 1704 /* 1705 * This should be easy, if there is something there we 1706 * return it, otherwise we block. 1707 */ 1708 1709 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 1710 int flags, int *addr_len) 1711 { 1712 struct inet_sock *inet = inet_sk(sk); 1713 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 1714 struct sk_buff *skb; 1715 unsigned int ulen, copied; 1716 int peeked, peeking, off; 1717 int err; 1718 int is_udplite = IS_UDPLITE(sk); 1719 bool checksum_valid = false; 1720 1721 if (flags & MSG_ERRQUEUE) 1722 return ip_recv_error(sk, msg, len, addr_len); 1723 1724 try_again: 1725 peeking = flags & MSG_PEEK; 1726 off = sk_peek_offset(sk, flags); 1727 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err); 1728 if (!skb) 1729 return err; 1730 1731 ulen = udp_skb_len(skb); 1732 copied = len; 1733 if (copied > ulen - off) 1734 copied = ulen - off; 1735 else if (copied < ulen) 1736 msg->msg_flags |= MSG_TRUNC; 1737 1738 /* 1739 * If checksum is needed at all, try to do it while copying the 1740 * data. If the data is truncated, or if we only want a partial 1741 * coverage checksum (UDP-Lite), do it before the copy. 1742 */ 1743 1744 if (copied < ulen || peeking || 1745 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { 1746 checksum_valid = udp_skb_csum_unnecessary(skb) || 1747 !__udp_lib_checksum_complete(skb); 1748 if (!checksum_valid) 1749 goto csum_copy_err; 1750 } 1751 1752 if (checksum_valid || udp_skb_csum_unnecessary(skb)) { 1753 if (udp_skb_is_linear(skb)) 1754 err = copy_linear_skb(skb, copied, off, &msg->msg_iter); 1755 else 1756 err = skb_copy_datagram_msg(skb, off, msg, copied); 1757 } else { 1758 err = skb_copy_and_csum_datagram_msg(skb, off, msg); 1759 1760 if (err == -EINVAL) 1761 goto csum_copy_err; 1762 } 1763 1764 if (unlikely(err)) { 1765 if (!peeked) { 1766 atomic_inc(&sk->sk_drops); 1767 UDP_INC_STATS(sock_net(sk), 1768 UDP_MIB_INERRORS, is_udplite); 1769 } 1770 kfree_skb(skb); 1771 return err; 1772 } 1773 1774 if (!peeked) 1775 UDP_INC_STATS(sock_net(sk), 1776 UDP_MIB_INDATAGRAMS, is_udplite); 1777 1778 sock_recv_ts_and_drops(msg, sk, skb); 1779 1780 /* Copy the address. */ 1781 if (sin) { 1782 sin->sin_family = AF_INET; 1783 sin->sin_port = udp_hdr(skb)->source; 1784 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1785 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1786 *addr_len = sizeof(*sin); 1787 } 1788 1789 if (udp_sk(sk)->gro_enabled) 1790 udp_cmsg_recv(msg, sk, skb); 1791 1792 if (inet->cmsg_flags) 1793 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off); 1794 1795 err = copied; 1796 if (flags & MSG_TRUNC) 1797 err = ulen; 1798 1799 skb_consume_udp(sk, skb, peeking ? -err : err); 1800 return err; 1801 1802 csum_copy_err: 1803 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, 1804 udp_skb_destructor)) { 1805 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1806 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1807 } 1808 kfree_skb(skb); 1809 1810 /* starting over for a new packet, but check if we need to yield */ 1811 cond_resched(); 1812 msg->msg_flags &= ~MSG_TRUNC; 1813 goto try_again; 1814 } 1815 1816 int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 1817 { 1818 /* This check is replicated from __ip4_datagram_connect() and 1819 * intended to prevent BPF program called below from accessing bytes 1820 * that are out of the bound specified by user in addr_len. 1821 */ 1822 if (addr_len < sizeof(struct sockaddr_in)) 1823 return -EINVAL; 1824 1825 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr); 1826 } 1827 EXPORT_SYMBOL(udp_pre_connect); 1828 1829 int __udp_disconnect(struct sock *sk, int flags) 1830 { 1831 struct inet_sock *inet = inet_sk(sk); 1832 /* 1833 * 1003.1g - break association. 1834 */ 1835 1836 sk->sk_state = TCP_CLOSE; 1837 inet->inet_daddr = 0; 1838 inet->inet_dport = 0; 1839 sock_rps_reset_rxhash(sk); 1840 sk->sk_bound_dev_if = 0; 1841 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1842 inet_reset_saddr(sk); 1843 1844 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1845 sk->sk_prot->unhash(sk); 1846 inet->inet_sport = 0; 1847 } 1848 sk_dst_reset(sk); 1849 return 0; 1850 } 1851 EXPORT_SYMBOL(__udp_disconnect); 1852 1853 int udp_disconnect(struct sock *sk, int flags) 1854 { 1855 lock_sock(sk); 1856 __udp_disconnect(sk, flags); 1857 release_sock(sk); 1858 return 0; 1859 } 1860 EXPORT_SYMBOL(udp_disconnect); 1861 1862 void udp_lib_unhash(struct sock *sk) 1863 { 1864 if (sk_hashed(sk)) { 1865 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1866 struct udp_hslot *hslot, *hslot2; 1867 1868 hslot = udp_hashslot(udptable, sock_net(sk), 1869 udp_sk(sk)->udp_port_hash); 1870 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1871 1872 spin_lock_bh(&hslot->lock); 1873 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1874 reuseport_detach_sock(sk); 1875 if (sk_del_node_init_rcu(sk)) { 1876 hslot->count--; 1877 inet_sk(sk)->inet_num = 0; 1878 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1879 1880 spin_lock(&hslot2->lock); 1881 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1882 hslot2->count--; 1883 spin_unlock(&hslot2->lock); 1884 } 1885 spin_unlock_bh(&hslot->lock); 1886 } 1887 } 1888 EXPORT_SYMBOL(udp_lib_unhash); 1889 1890 /* 1891 * inet_rcv_saddr was changed, we must rehash secondary hash 1892 */ 1893 void udp_lib_rehash(struct sock *sk, u16 newhash) 1894 { 1895 if (sk_hashed(sk)) { 1896 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1897 struct udp_hslot *hslot, *hslot2, *nhslot2; 1898 1899 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1900 nhslot2 = udp_hashslot2(udptable, newhash); 1901 udp_sk(sk)->udp_portaddr_hash = newhash; 1902 1903 if (hslot2 != nhslot2 || 1904 rcu_access_pointer(sk->sk_reuseport_cb)) { 1905 hslot = udp_hashslot(udptable, sock_net(sk), 1906 udp_sk(sk)->udp_port_hash); 1907 /* we must lock primary chain too */ 1908 spin_lock_bh(&hslot->lock); 1909 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1910 reuseport_detach_sock(sk); 1911 1912 if (hslot2 != nhslot2) { 1913 spin_lock(&hslot2->lock); 1914 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1915 hslot2->count--; 1916 spin_unlock(&hslot2->lock); 1917 1918 spin_lock(&nhslot2->lock); 1919 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1920 &nhslot2->head); 1921 nhslot2->count++; 1922 spin_unlock(&nhslot2->lock); 1923 } 1924 1925 spin_unlock_bh(&hslot->lock); 1926 } 1927 } 1928 } 1929 EXPORT_SYMBOL(udp_lib_rehash); 1930 1931 void udp_v4_rehash(struct sock *sk) 1932 { 1933 u16 new_hash = ipv4_portaddr_hash(sock_net(sk), 1934 inet_sk(sk)->inet_rcv_saddr, 1935 inet_sk(sk)->inet_num); 1936 udp_lib_rehash(sk, new_hash); 1937 } 1938 1939 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1940 { 1941 int rc; 1942 1943 if (inet_sk(sk)->inet_daddr) { 1944 sock_rps_save_rxhash(sk, skb); 1945 sk_mark_napi_id(sk, skb); 1946 sk_incoming_cpu_update(sk); 1947 } else { 1948 sk_mark_napi_id_once(sk, skb); 1949 } 1950 1951 rc = __udp_enqueue_schedule_skb(sk, skb); 1952 if (rc < 0) { 1953 int is_udplite = IS_UDPLITE(sk); 1954 1955 /* Note that an ENOMEM error is charged twice */ 1956 if (rc == -ENOMEM) 1957 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1958 is_udplite); 1959 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1960 kfree_skb(skb); 1961 trace_udp_fail_queue_rcv_skb(rc, sk); 1962 return -1; 1963 } 1964 1965 return 0; 1966 } 1967 1968 /* returns: 1969 * -1: error 1970 * 0: success 1971 * >0: "udp encap" protocol resubmission 1972 * 1973 * Note that in the success and error cases, the skb is assumed to 1974 * have either been requeued or freed. 1975 */ 1976 static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb) 1977 { 1978 struct udp_sock *up = udp_sk(sk); 1979 int is_udplite = IS_UDPLITE(sk); 1980 1981 /* 1982 * Charge it to the socket, dropping if the queue is full. 1983 */ 1984 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1985 goto drop; 1986 nf_reset(skb); 1987 1988 if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) { 1989 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 1990 1991 /* 1992 * This is an encapsulation socket so pass the skb to 1993 * the socket's udp_encap_rcv() hook. Otherwise, just 1994 * fall through and pass this up the UDP socket. 1995 * up->encap_rcv() returns the following value: 1996 * =0 if skb was successfully passed to the encap 1997 * handler or was discarded by it. 1998 * >0 if skb should be passed on to UDP. 1999 * <0 if skb should be resubmitted as proto -N 2000 */ 2001 2002 /* if we're overly short, let UDP handle it */ 2003 encap_rcv = READ_ONCE(up->encap_rcv); 2004 if (encap_rcv) { 2005 int ret; 2006 2007 /* Verify checksum before giving to encap */ 2008 if (udp_lib_checksum_complete(skb)) 2009 goto csum_error; 2010 2011 ret = encap_rcv(sk, skb); 2012 if (ret <= 0) { 2013 __UDP_INC_STATS(sock_net(sk), 2014 UDP_MIB_INDATAGRAMS, 2015 is_udplite); 2016 return -ret; 2017 } 2018 } 2019 2020 /* FALLTHROUGH -- it's a UDP Packet */ 2021 } 2022 2023 /* 2024 * UDP-Lite specific tests, ignored on UDP sockets 2025 */ 2026 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 2027 2028 /* 2029 * MIB statistics other than incrementing the error count are 2030 * disabled for the following two types of errors: these depend 2031 * on the application settings, not on the functioning of the 2032 * protocol stack as such. 2033 * 2034 * RFC 3828 here recommends (sec 3.3): "There should also be a 2035 * way ... to ... at least let the receiving application block 2036 * delivery of packets with coverage values less than a value 2037 * provided by the application." 2038 */ 2039 if (up->pcrlen == 0) { /* full coverage was set */ 2040 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n", 2041 UDP_SKB_CB(skb)->cscov, skb->len); 2042 goto drop; 2043 } 2044 /* The next case involves violating the min. coverage requested 2045 * by the receiver. This is subtle: if receiver wants x and x is 2046 * greater than the buffersize/MTU then receiver will complain 2047 * that it wants x while sender emits packets of smaller size y. 2048 * Therefore the above ...()->partial_cov statement is essential. 2049 */ 2050 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 2051 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n", 2052 UDP_SKB_CB(skb)->cscov, up->pcrlen); 2053 goto drop; 2054 } 2055 } 2056 2057 prefetch(&sk->sk_rmem_alloc); 2058 if (rcu_access_pointer(sk->sk_filter) && 2059 udp_lib_checksum_complete(skb)) 2060 goto csum_error; 2061 2062 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 2063 goto drop; 2064 2065 udp_csum_pull_header(skb); 2066 2067 ipv4_pktinfo_prepare(sk, skb); 2068 return __udp_queue_rcv_skb(sk, skb); 2069 2070 csum_error: 2071 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 2072 drop: 2073 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 2074 atomic_inc(&sk->sk_drops); 2075 kfree_skb(skb); 2076 return -1; 2077 } 2078 2079 static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 2080 { 2081 struct sk_buff *next, *segs; 2082 int ret; 2083 2084 if (likely(!udp_unexpected_gso(sk, skb))) 2085 return udp_queue_rcv_one_skb(sk, skb); 2086 2087 BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_SGO_CB_OFFSET); 2088 __skb_push(skb, -skb_mac_offset(skb)); 2089 segs = udp_rcv_segment(sk, skb, true); 2090 for (skb = segs; skb; skb = next) { 2091 next = skb->next; 2092 __skb_pull(skb, skb_transport_offset(skb)); 2093 ret = udp_queue_rcv_one_skb(sk, skb); 2094 if (ret > 0) 2095 ip_protocol_deliver_rcu(dev_net(skb->dev), skb, -ret); 2096 } 2097 return 0; 2098 } 2099 2100 /* For TCP sockets, sk_rx_dst is protected by socket lock 2101 * For UDP, we use xchg() to guard against concurrent changes. 2102 */ 2103 bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 2104 { 2105 struct dst_entry *old; 2106 2107 if (dst_hold_safe(dst)) { 2108 old = xchg(&sk->sk_rx_dst, dst); 2109 dst_release(old); 2110 return old != dst; 2111 } 2112 return false; 2113 } 2114 EXPORT_SYMBOL(udp_sk_rx_dst_set); 2115 2116 /* 2117 * Multicasts and broadcasts go to each listener. 2118 * 2119 * Note: called only from the BH handler context. 2120 */ 2121 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 2122 struct udphdr *uh, 2123 __be32 saddr, __be32 daddr, 2124 struct udp_table *udptable, 2125 int proto) 2126 { 2127 struct sock *sk, *first = NULL; 2128 unsigned short hnum = ntohs(uh->dest); 2129 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 2130 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 2131 unsigned int offset = offsetof(typeof(*sk), sk_node); 2132 int dif = skb->dev->ifindex; 2133 int sdif = inet_sdif(skb); 2134 struct hlist_node *node; 2135 struct sk_buff *nskb; 2136 2137 if (use_hash2) { 2138 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & 2139 udptable->mask; 2140 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask; 2141 start_lookup: 2142 hslot = &udptable->hash2[hash2]; 2143 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 2144 } 2145 2146 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 2147 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr, 2148 uh->source, saddr, dif, sdif, hnum)) 2149 continue; 2150 2151 if (!first) { 2152 first = sk; 2153 continue; 2154 } 2155 nskb = skb_clone(skb, GFP_ATOMIC); 2156 2157 if (unlikely(!nskb)) { 2158 atomic_inc(&sk->sk_drops); 2159 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 2160 IS_UDPLITE(sk)); 2161 __UDP_INC_STATS(net, UDP_MIB_INERRORS, 2162 IS_UDPLITE(sk)); 2163 continue; 2164 } 2165 if (udp_queue_rcv_skb(sk, nskb) > 0) 2166 consume_skb(nskb); 2167 } 2168 2169 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 2170 if (use_hash2 && hash2 != hash2_any) { 2171 hash2 = hash2_any; 2172 goto start_lookup; 2173 } 2174 2175 if (first) { 2176 if (udp_queue_rcv_skb(first, skb) > 0) 2177 consume_skb(skb); 2178 } else { 2179 kfree_skb(skb); 2180 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 2181 proto == IPPROTO_UDPLITE); 2182 } 2183 return 0; 2184 } 2185 2186 /* Initialize UDP checksum. If exited with zero value (success), 2187 * CHECKSUM_UNNECESSARY means, that no more checks are required. 2188 * Otherwise, csum completion requires chacksumming packet body, 2189 * including udp header and folding it to skb->csum. 2190 */ 2191 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 2192 int proto) 2193 { 2194 int err; 2195 2196 UDP_SKB_CB(skb)->partial_cov = 0; 2197 UDP_SKB_CB(skb)->cscov = skb->len; 2198 2199 if (proto == IPPROTO_UDPLITE) { 2200 err = udplite_checksum_init(skb, uh); 2201 if (err) 2202 return err; 2203 2204 if (UDP_SKB_CB(skb)->partial_cov) { 2205 skb->csum = inet_compute_pseudo(skb, proto); 2206 return 0; 2207 } 2208 } 2209 2210 /* Note, we are only interested in != 0 or == 0, thus the 2211 * force to int. 2212 */ 2213 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check, 2214 inet_compute_pseudo); 2215 if (err) 2216 return err; 2217 2218 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) { 2219 /* If SW calculated the value, we know it's bad */ 2220 if (skb->csum_complete_sw) 2221 return 1; 2222 2223 /* HW says the value is bad. Let's validate that. 2224 * skb->csum is no longer the full packet checksum, 2225 * so don't treat it as such. 2226 */ 2227 skb_checksum_complete_unset(skb); 2228 } 2229 2230 return 0; 2231 } 2232 2233 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and 2234 * return code conversion for ip layer consumption 2235 */ 2236 static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb, 2237 struct udphdr *uh) 2238 { 2239 int ret; 2240 2241 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 2242 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, 2243 inet_compute_pseudo); 2244 2245 ret = udp_queue_rcv_skb(sk, skb); 2246 2247 /* a return value > 0 means to resubmit the input, but 2248 * it wants the return to be -protocol, or 0 2249 */ 2250 if (ret > 0) 2251 return -ret; 2252 return 0; 2253 } 2254 2255 /* 2256 * All we need to do is get the socket, and then do a checksum. 2257 */ 2258 2259 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 2260 int proto) 2261 { 2262 struct sock *sk; 2263 struct udphdr *uh; 2264 unsigned short ulen; 2265 struct rtable *rt = skb_rtable(skb); 2266 __be32 saddr, daddr; 2267 struct net *net = dev_net(skb->dev); 2268 2269 /* 2270 * Validate the packet. 2271 */ 2272 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 2273 goto drop; /* No space for header. */ 2274 2275 uh = udp_hdr(skb); 2276 ulen = ntohs(uh->len); 2277 saddr = ip_hdr(skb)->saddr; 2278 daddr = ip_hdr(skb)->daddr; 2279 2280 if (ulen > skb->len) 2281 goto short_packet; 2282 2283 if (proto == IPPROTO_UDP) { 2284 /* UDP validates ulen. */ 2285 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 2286 goto short_packet; 2287 uh = udp_hdr(skb); 2288 } 2289 2290 if (udp4_csum_init(skb, uh, proto)) 2291 goto csum_error; 2292 2293 sk = skb_steal_sock(skb); 2294 if (sk) { 2295 struct dst_entry *dst = skb_dst(skb); 2296 int ret; 2297 2298 if (unlikely(sk->sk_rx_dst != dst)) 2299 udp_sk_rx_dst_set(sk, dst); 2300 2301 ret = udp_unicast_rcv_skb(sk, skb, uh); 2302 sock_put(sk); 2303 return ret; 2304 } 2305 2306 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 2307 return __udp4_lib_mcast_deliver(net, skb, uh, 2308 saddr, daddr, udptable, proto); 2309 2310 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 2311 if (sk) 2312 return udp_unicast_rcv_skb(sk, skb, uh); 2313 2314 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 2315 goto drop; 2316 nf_reset(skb); 2317 2318 /* No socket. Drop packet silently, if checksum is wrong */ 2319 if (udp_lib_checksum_complete(skb)) 2320 goto csum_error; 2321 2322 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 2323 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 2324 2325 /* 2326 * Hmm. We got an UDP packet to a port to which we 2327 * don't wanna listen. Ignore it. 2328 */ 2329 kfree_skb(skb); 2330 return 0; 2331 2332 short_packet: 2333 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 2334 proto == IPPROTO_UDPLITE ? "Lite" : "", 2335 &saddr, ntohs(uh->source), 2336 ulen, skb->len, 2337 &daddr, ntohs(uh->dest)); 2338 goto drop; 2339 2340 csum_error: 2341 /* 2342 * RFC1122: OK. Discards the bad packet silently (as far as 2343 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 2344 */ 2345 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 2346 proto == IPPROTO_UDPLITE ? "Lite" : "", 2347 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 2348 ulen); 2349 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 2350 drop: 2351 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 2352 kfree_skb(skb); 2353 return 0; 2354 } 2355 2356 /* We can only early demux multicast if there is a single matching socket. 2357 * If more than one socket found returns NULL 2358 */ 2359 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, 2360 __be16 loc_port, __be32 loc_addr, 2361 __be16 rmt_port, __be32 rmt_addr, 2362 int dif, int sdif) 2363 { 2364 struct sock *sk, *result; 2365 unsigned short hnum = ntohs(loc_port); 2366 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask); 2367 struct udp_hslot *hslot = &udp_table.hash[slot]; 2368 2369 /* Do not bother scanning a too big list */ 2370 if (hslot->count > 10) 2371 return NULL; 2372 2373 result = NULL; 2374 sk_for_each_rcu(sk, &hslot->head) { 2375 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr, 2376 rmt_port, rmt_addr, dif, sdif, hnum)) { 2377 if (result) 2378 return NULL; 2379 result = sk; 2380 } 2381 } 2382 2383 return result; 2384 } 2385 2386 /* For unicast we should only early demux connected sockets or we can 2387 * break forwarding setups. The chains here can be long so only check 2388 * if the first socket is an exact match and if not move on. 2389 */ 2390 static struct sock *__udp4_lib_demux_lookup(struct net *net, 2391 __be16 loc_port, __be32 loc_addr, 2392 __be16 rmt_port, __be32 rmt_addr, 2393 int dif, int sdif) 2394 { 2395 unsigned short hnum = ntohs(loc_port); 2396 unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum); 2397 unsigned int slot2 = hash2 & udp_table.mask; 2398 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 2399 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); 2400 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 2401 struct sock *sk; 2402 2403 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 2404 if (INET_MATCH(sk, net, acookie, rmt_addr, 2405 loc_addr, ports, dif, sdif)) 2406 return sk; 2407 /* Only check first socket in chain */ 2408 break; 2409 } 2410 return NULL; 2411 } 2412 2413 int udp_v4_early_demux(struct sk_buff *skb) 2414 { 2415 struct net *net = dev_net(skb->dev); 2416 struct in_device *in_dev = NULL; 2417 const struct iphdr *iph; 2418 const struct udphdr *uh; 2419 struct sock *sk = NULL; 2420 struct dst_entry *dst; 2421 int dif = skb->dev->ifindex; 2422 int sdif = inet_sdif(skb); 2423 int ours; 2424 2425 /* validate the packet */ 2426 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) 2427 return 0; 2428 2429 iph = ip_hdr(skb); 2430 uh = udp_hdr(skb); 2431 2432 if (skb->pkt_type == PACKET_MULTICAST) { 2433 in_dev = __in_dev_get_rcu(skb->dev); 2434 2435 if (!in_dev) 2436 return 0; 2437 2438 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, 2439 iph->protocol); 2440 if (!ours) 2441 return 0; 2442 2443 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, 2444 uh->source, iph->saddr, 2445 dif, sdif); 2446 } else if (skb->pkt_type == PACKET_HOST) { 2447 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, 2448 uh->source, iph->saddr, dif, sdif); 2449 } 2450 2451 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 2452 return 0; 2453 2454 skb->sk = sk; 2455 skb->destructor = sock_efree; 2456 dst = READ_ONCE(sk->sk_rx_dst); 2457 2458 if (dst) 2459 dst = dst_check(dst, 0); 2460 if (dst) { 2461 u32 itag = 0; 2462 2463 /* set noref for now. 2464 * any place which wants to hold dst has to call 2465 * dst_hold_safe() 2466 */ 2467 skb_dst_set_noref(skb, dst); 2468 2469 /* for unconnected multicast sockets we need to validate 2470 * the source on each packet 2471 */ 2472 if (!inet_sk(sk)->inet_daddr && in_dev) 2473 return ip_mc_validate_source(skb, iph->daddr, 2474 iph->saddr, iph->tos, 2475 skb->dev, in_dev, &itag); 2476 } 2477 return 0; 2478 } 2479 2480 int udp_rcv(struct sk_buff *skb) 2481 { 2482 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 2483 } 2484 2485 void udp_destroy_sock(struct sock *sk) 2486 { 2487 struct udp_sock *up = udp_sk(sk); 2488 bool slow = lock_sock_fast(sk); 2489 udp_flush_pending_frames(sk); 2490 unlock_sock_fast(sk, slow); 2491 if (static_branch_unlikely(&udp_encap_needed_key)) { 2492 if (up->encap_type) { 2493 void (*encap_destroy)(struct sock *sk); 2494 encap_destroy = READ_ONCE(up->encap_destroy); 2495 if (encap_destroy) 2496 encap_destroy(sk); 2497 } 2498 if (up->encap_enabled) 2499 static_branch_dec(&udp_encap_needed_key); 2500 } 2501 } 2502 2503 /* 2504 * Socket option code for UDP 2505 */ 2506 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 2507 char __user *optval, unsigned int optlen, 2508 int (*push_pending_frames)(struct sock *)) 2509 { 2510 struct udp_sock *up = udp_sk(sk); 2511 int val, valbool; 2512 int err = 0; 2513 int is_udplite = IS_UDPLITE(sk); 2514 2515 if (optlen < sizeof(int)) 2516 return -EINVAL; 2517 2518 if (get_user(val, (int __user *)optval)) 2519 return -EFAULT; 2520 2521 valbool = val ? 1 : 0; 2522 2523 switch (optname) { 2524 case UDP_CORK: 2525 if (val != 0) { 2526 up->corkflag = 1; 2527 } else { 2528 up->corkflag = 0; 2529 lock_sock(sk); 2530 push_pending_frames(sk); 2531 release_sock(sk); 2532 } 2533 break; 2534 2535 case UDP_ENCAP: 2536 switch (val) { 2537 case 0: 2538 case UDP_ENCAP_ESPINUDP: 2539 case UDP_ENCAP_ESPINUDP_NON_IKE: 2540 up->encap_rcv = xfrm4_udp_encap_rcv; 2541 /* FALLTHROUGH */ 2542 case UDP_ENCAP_L2TPINUDP: 2543 up->encap_type = val; 2544 lock_sock(sk); 2545 udp_tunnel_encap_enable(sk->sk_socket); 2546 release_sock(sk); 2547 break; 2548 default: 2549 err = -ENOPROTOOPT; 2550 break; 2551 } 2552 break; 2553 2554 case UDP_NO_CHECK6_TX: 2555 up->no_check6_tx = valbool; 2556 break; 2557 2558 case UDP_NO_CHECK6_RX: 2559 up->no_check6_rx = valbool; 2560 break; 2561 2562 case UDP_SEGMENT: 2563 if (val < 0 || val > USHRT_MAX) 2564 return -EINVAL; 2565 up->gso_size = val; 2566 break; 2567 2568 case UDP_GRO: 2569 lock_sock(sk); 2570 if (valbool) 2571 udp_tunnel_encap_enable(sk->sk_socket); 2572 up->gro_enabled = valbool; 2573 release_sock(sk); 2574 break; 2575 2576 /* 2577 * UDP-Lite's partial checksum coverage (RFC 3828). 2578 */ 2579 /* The sender sets actual checksum coverage length via this option. 2580 * The case coverage > packet length is handled by send module. */ 2581 case UDPLITE_SEND_CSCOV: 2582 if (!is_udplite) /* Disable the option on UDP sockets */ 2583 return -ENOPROTOOPT; 2584 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 2585 val = 8; 2586 else if (val > USHRT_MAX) 2587 val = USHRT_MAX; 2588 up->pcslen = val; 2589 up->pcflag |= UDPLITE_SEND_CC; 2590 break; 2591 2592 /* The receiver specifies a minimum checksum coverage value. To make 2593 * sense, this should be set to at least 8 (as done below). If zero is 2594 * used, this again means full checksum coverage. */ 2595 case UDPLITE_RECV_CSCOV: 2596 if (!is_udplite) /* Disable the option on UDP sockets */ 2597 return -ENOPROTOOPT; 2598 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 2599 val = 8; 2600 else if (val > USHRT_MAX) 2601 val = USHRT_MAX; 2602 up->pcrlen = val; 2603 up->pcflag |= UDPLITE_RECV_CC; 2604 break; 2605 2606 default: 2607 err = -ENOPROTOOPT; 2608 break; 2609 } 2610 2611 return err; 2612 } 2613 EXPORT_SYMBOL(udp_lib_setsockopt); 2614 2615 int udp_setsockopt(struct sock *sk, int level, int optname, 2616 char __user *optval, unsigned int optlen) 2617 { 2618 if (level == SOL_UDP || level == SOL_UDPLITE) 2619 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2620 udp_push_pending_frames); 2621 return ip_setsockopt(sk, level, optname, optval, optlen); 2622 } 2623 2624 #ifdef CONFIG_COMPAT 2625 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 2626 char __user *optval, unsigned int optlen) 2627 { 2628 if (level == SOL_UDP || level == SOL_UDPLITE) 2629 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2630 udp_push_pending_frames); 2631 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 2632 } 2633 #endif 2634 2635 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 2636 char __user *optval, int __user *optlen) 2637 { 2638 struct udp_sock *up = udp_sk(sk); 2639 int val, len; 2640 2641 if (get_user(len, optlen)) 2642 return -EFAULT; 2643 2644 len = min_t(unsigned int, len, sizeof(int)); 2645 2646 if (len < 0) 2647 return -EINVAL; 2648 2649 switch (optname) { 2650 case UDP_CORK: 2651 val = up->corkflag; 2652 break; 2653 2654 case UDP_ENCAP: 2655 val = up->encap_type; 2656 break; 2657 2658 case UDP_NO_CHECK6_TX: 2659 val = up->no_check6_tx; 2660 break; 2661 2662 case UDP_NO_CHECK6_RX: 2663 val = up->no_check6_rx; 2664 break; 2665 2666 case UDP_SEGMENT: 2667 val = up->gso_size; 2668 break; 2669 2670 /* The following two cannot be changed on UDP sockets, the return is 2671 * always 0 (which corresponds to the full checksum coverage of UDP). */ 2672 case UDPLITE_SEND_CSCOV: 2673 val = up->pcslen; 2674 break; 2675 2676 case UDPLITE_RECV_CSCOV: 2677 val = up->pcrlen; 2678 break; 2679 2680 default: 2681 return -ENOPROTOOPT; 2682 } 2683 2684 if (put_user(len, optlen)) 2685 return -EFAULT; 2686 if (copy_to_user(optval, &val, len)) 2687 return -EFAULT; 2688 return 0; 2689 } 2690 EXPORT_SYMBOL(udp_lib_getsockopt); 2691 2692 int udp_getsockopt(struct sock *sk, int level, int optname, 2693 char __user *optval, int __user *optlen) 2694 { 2695 if (level == SOL_UDP || level == SOL_UDPLITE) 2696 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2697 return ip_getsockopt(sk, level, optname, optval, optlen); 2698 } 2699 2700 #ifdef CONFIG_COMPAT 2701 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 2702 char __user *optval, int __user *optlen) 2703 { 2704 if (level == SOL_UDP || level == SOL_UDPLITE) 2705 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2706 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 2707 } 2708 #endif 2709 /** 2710 * udp_poll - wait for a UDP event. 2711 * @file - file struct 2712 * @sock - socket 2713 * @wait - poll table 2714 * 2715 * This is same as datagram poll, except for the special case of 2716 * blocking sockets. If application is using a blocking fd 2717 * and a packet with checksum error is in the queue; 2718 * then it could get return from select indicating data available 2719 * but then block when reading it. Add special case code 2720 * to work around these arguably broken applications. 2721 */ 2722 __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait) 2723 { 2724 __poll_t mask = datagram_poll(file, sock, wait); 2725 struct sock *sk = sock->sk; 2726 2727 if (!skb_queue_empty(&udp_sk(sk)->reader_queue)) 2728 mask |= EPOLLIN | EPOLLRDNORM; 2729 2730 /* Check for false positives due to checksum errors */ 2731 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 2732 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1) 2733 mask &= ~(EPOLLIN | EPOLLRDNORM); 2734 2735 return mask; 2736 2737 } 2738 EXPORT_SYMBOL(udp_poll); 2739 2740 int udp_abort(struct sock *sk, int err) 2741 { 2742 lock_sock(sk); 2743 2744 sk->sk_err = err; 2745 sk->sk_error_report(sk); 2746 __udp_disconnect(sk, 0); 2747 2748 release_sock(sk); 2749 2750 return 0; 2751 } 2752 EXPORT_SYMBOL_GPL(udp_abort); 2753 2754 struct proto udp_prot = { 2755 .name = "UDP", 2756 .owner = THIS_MODULE, 2757 .close = udp_lib_close, 2758 .pre_connect = udp_pre_connect, 2759 .connect = ip4_datagram_connect, 2760 .disconnect = udp_disconnect, 2761 .ioctl = udp_ioctl, 2762 .init = udp_init_sock, 2763 .destroy = udp_destroy_sock, 2764 .setsockopt = udp_setsockopt, 2765 .getsockopt = udp_getsockopt, 2766 .sendmsg = udp_sendmsg, 2767 .recvmsg = udp_recvmsg, 2768 .sendpage = udp_sendpage, 2769 .release_cb = ip4_datagram_release_cb, 2770 .hash = udp_lib_hash, 2771 .unhash = udp_lib_unhash, 2772 .rehash = udp_v4_rehash, 2773 .get_port = udp_v4_get_port, 2774 .memory_allocated = &udp_memory_allocated, 2775 .sysctl_mem = sysctl_udp_mem, 2776 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), 2777 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), 2778 .obj_size = sizeof(struct udp_sock), 2779 .h.udp_table = &udp_table, 2780 #ifdef CONFIG_COMPAT 2781 .compat_setsockopt = compat_udp_setsockopt, 2782 .compat_getsockopt = compat_udp_getsockopt, 2783 #endif 2784 .diag_destroy = udp_abort, 2785 }; 2786 EXPORT_SYMBOL(udp_prot); 2787 2788 /* ------------------------------------------------------------------------ */ 2789 #ifdef CONFIG_PROC_FS 2790 2791 static struct sock *udp_get_first(struct seq_file *seq, int start) 2792 { 2793 struct sock *sk; 2794 struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file)); 2795 struct udp_iter_state *state = seq->private; 2796 struct net *net = seq_file_net(seq); 2797 2798 for (state->bucket = start; state->bucket <= afinfo->udp_table->mask; 2799 ++state->bucket) { 2800 struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket]; 2801 2802 if (hlist_empty(&hslot->head)) 2803 continue; 2804 2805 spin_lock_bh(&hslot->lock); 2806 sk_for_each(sk, &hslot->head) { 2807 if (!net_eq(sock_net(sk), net)) 2808 continue; 2809 if (sk->sk_family == afinfo->family) 2810 goto found; 2811 } 2812 spin_unlock_bh(&hslot->lock); 2813 } 2814 sk = NULL; 2815 found: 2816 return sk; 2817 } 2818 2819 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2820 { 2821 struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file)); 2822 struct udp_iter_state *state = seq->private; 2823 struct net *net = seq_file_net(seq); 2824 2825 do { 2826 sk = sk_next(sk); 2827 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != afinfo->family)); 2828 2829 if (!sk) { 2830 if (state->bucket <= afinfo->udp_table->mask) 2831 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); 2832 return udp_get_first(seq, state->bucket + 1); 2833 } 2834 return sk; 2835 } 2836 2837 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2838 { 2839 struct sock *sk = udp_get_first(seq, 0); 2840 2841 if (sk) 2842 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2843 --pos; 2844 return pos ? NULL : sk; 2845 } 2846 2847 void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2848 { 2849 struct udp_iter_state *state = seq->private; 2850 state->bucket = MAX_UDP_PORTS; 2851 2852 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2853 } 2854 EXPORT_SYMBOL(udp_seq_start); 2855 2856 void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2857 { 2858 struct sock *sk; 2859 2860 if (v == SEQ_START_TOKEN) 2861 sk = udp_get_idx(seq, 0); 2862 else 2863 sk = udp_get_next(seq, v); 2864 2865 ++*pos; 2866 return sk; 2867 } 2868 EXPORT_SYMBOL(udp_seq_next); 2869 2870 void udp_seq_stop(struct seq_file *seq, void *v) 2871 { 2872 struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file)); 2873 struct udp_iter_state *state = seq->private; 2874 2875 if (state->bucket <= afinfo->udp_table->mask) 2876 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); 2877 } 2878 EXPORT_SYMBOL(udp_seq_stop); 2879 2880 /* ------------------------------------------------------------------------ */ 2881 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2882 int bucket) 2883 { 2884 struct inet_sock *inet = inet_sk(sp); 2885 __be32 dest = inet->inet_daddr; 2886 __be32 src = inet->inet_rcv_saddr; 2887 __u16 destp = ntohs(inet->inet_dport); 2888 __u16 srcp = ntohs(inet->inet_sport); 2889 2890 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2891 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 2892 bucket, src, srcp, dest, destp, sp->sk_state, 2893 sk_wmem_alloc_get(sp), 2894 udp_rqueue_get(sp), 2895 0, 0L, 0, 2896 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2897 0, sock_i_ino(sp), 2898 refcount_read(&sp->sk_refcnt), sp, 2899 atomic_read(&sp->sk_drops)); 2900 } 2901 2902 int udp4_seq_show(struct seq_file *seq, void *v) 2903 { 2904 seq_setwidth(seq, 127); 2905 if (v == SEQ_START_TOKEN) 2906 seq_puts(seq, " sl local_address rem_address st tx_queue " 2907 "rx_queue tr tm->when retrnsmt uid timeout " 2908 "inode ref pointer drops"); 2909 else { 2910 struct udp_iter_state *state = seq->private; 2911 2912 udp4_format_sock(v, seq, state->bucket); 2913 } 2914 seq_pad(seq, '\n'); 2915 return 0; 2916 } 2917 2918 const struct seq_operations udp_seq_ops = { 2919 .start = udp_seq_start, 2920 .next = udp_seq_next, 2921 .stop = udp_seq_stop, 2922 .show = udp4_seq_show, 2923 }; 2924 EXPORT_SYMBOL(udp_seq_ops); 2925 2926 static struct udp_seq_afinfo udp4_seq_afinfo = { 2927 .family = AF_INET, 2928 .udp_table = &udp_table, 2929 }; 2930 2931 static int __net_init udp4_proc_init_net(struct net *net) 2932 { 2933 if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops, 2934 sizeof(struct udp_iter_state), &udp4_seq_afinfo)) 2935 return -ENOMEM; 2936 return 0; 2937 } 2938 2939 static void __net_exit udp4_proc_exit_net(struct net *net) 2940 { 2941 remove_proc_entry("udp", net->proc_net); 2942 } 2943 2944 static struct pernet_operations udp4_net_ops = { 2945 .init = udp4_proc_init_net, 2946 .exit = udp4_proc_exit_net, 2947 }; 2948 2949 int __init udp4_proc_init(void) 2950 { 2951 return register_pernet_subsys(&udp4_net_ops); 2952 } 2953 2954 void udp4_proc_exit(void) 2955 { 2956 unregister_pernet_subsys(&udp4_net_ops); 2957 } 2958 #endif /* CONFIG_PROC_FS */ 2959 2960 static __initdata unsigned long uhash_entries; 2961 static int __init set_uhash_entries(char *str) 2962 { 2963 ssize_t ret; 2964 2965 if (!str) 2966 return 0; 2967 2968 ret = kstrtoul(str, 0, &uhash_entries); 2969 if (ret) 2970 return 0; 2971 2972 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2973 uhash_entries = UDP_HTABLE_SIZE_MIN; 2974 return 1; 2975 } 2976 __setup("uhash_entries=", set_uhash_entries); 2977 2978 void __init udp_table_init(struct udp_table *table, const char *name) 2979 { 2980 unsigned int i; 2981 2982 table->hash = alloc_large_system_hash(name, 2983 2 * sizeof(struct udp_hslot), 2984 uhash_entries, 2985 21, /* one slot per 2 MB */ 2986 0, 2987 &table->log, 2988 &table->mask, 2989 UDP_HTABLE_SIZE_MIN, 2990 64 * 1024); 2991 2992 table->hash2 = table->hash + (table->mask + 1); 2993 for (i = 0; i <= table->mask; i++) { 2994 INIT_HLIST_HEAD(&table->hash[i].head); 2995 table->hash[i].count = 0; 2996 spin_lock_init(&table->hash[i].lock); 2997 } 2998 for (i = 0; i <= table->mask; i++) { 2999 INIT_HLIST_HEAD(&table->hash2[i].head); 3000 table->hash2[i].count = 0; 3001 spin_lock_init(&table->hash2[i].lock); 3002 } 3003 } 3004 3005 u32 udp_flow_hashrnd(void) 3006 { 3007 static u32 hashrnd __read_mostly; 3008 3009 net_get_random_once(&hashrnd, sizeof(hashrnd)); 3010 3011 return hashrnd; 3012 } 3013 EXPORT_SYMBOL(udp_flow_hashrnd); 3014 3015 static void __udp_sysctl_init(struct net *net) 3016 { 3017 net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM; 3018 net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM; 3019 3020 #ifdef CONFIG_NET_L3_MASTER_DEV 3021 net->ipv4.sysctl_udp_l3mdev_accept = 0; 3022 #endif 3023 } 3024 3025 static int __net_init udp_sysctl_init(struct net *net) 3026 { 3027 __udp_sysctl_init(net); 3028 return 0; 3029 } 3030 3031 static struct pernet_operations __net_initdata udp_sysctl_ops = { 3032 .init = udp_sysctl_init, 3033 }; 3034 3035 void __init udp_init(void) 3036 { 3037 unsigned long limit; 3038 unsigned int i; 3039 3040 udp_table_init(&udp_table, "UDP"); 3041 limit = nr_free_buffer_pages() / 8; 3042 limit = max(limit, 128UL); 3043 sysctl_udp_mem[0] = limit / 4 * 3; 3044 sysctl_udp_mem[1] = limit; 3045 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 3046 3047 __udp_sysctl_init(&init_net); 3048 3049 /* 16 spinlocks per cpu */ 3050 udp_busylocks_log = ilog2(nr_cpu_ids) + 4; 3051 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log, 3052 GFP_KERNEL); 3053 if (!udp_busylocks) 3054 panic("UDP: failed to alloc udp_busylocks\n"); 3055 for (i = 0; i < (1U << udp_busylocks_log); i++) 3056 spin_lock_init(udp_busylocks + i); 3057 3058 if (register_pernet_subsys(&udp_sysctl_ops)) 3059 panic("UDP: failed to init sysctl parameters.\n"); 3060 } 3061