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 <trace/events/skb.h> 110 #include <net/busy_poll.h> 111 #include "udp_impl.h" 112 #include <net/sock_reuseport.h> 113 #include <net/addrconf.h> 114 #include <net/udp_tunnel.h> 115 116 struct udp_table udp_table __read_mostly; 117 EXPORT_SYMBOL(udp_table); 118 119 long sysctl_udp_mem[3] __read_mostly; 120 EXPORT_SYMBOL(sysctl_udp_mem); 121 122 atomic_long_t udp_memory_allocated; 123 EXPORT_SYMBOL(udp_memory_allocated); 124 125 #define MAX_UDP_PORTS 65536 126 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 127 128 static int udp_lib_lport_inuse(struct net *net, __u16 num, 129 const struct udp_hslot *hslot, 130 unsigned long *bitmap, 131 struct sock *sk, unsigned int log) 132 { 133 struct sock *sk2; 134 kuid_t uid = sock_i_uid(sk); 135 136 sk_for_each(sk2, &hslot->head) { 137 if (net_eq(sock_net(sk2), net) && 138 sk2 != sk && 139 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 140 (!sk2->sk_reuse || !sk->sk_reuse) && 141 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 142 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 143 inet_rcv_saddr_equal(sk, sk2, true)) { 144 if (sk2->sk_reuseport && sk->sk_reuseport && 145 !rcu_access_pointer(sk->sk_reuseport_cb) && 146 uid_eq(uid, sock_i_uid(sk2))) { 147 if (!bitmap) 148 return 0; 149 } else { 150 if (!bitmap) 151 return 1; 152 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 153 bitmap); 154 } 155 } 156 } 157 return 0; 158 } 159 160 /* 161 * Note: we still hold spinlock of primary hash chain, so no other writer 162 * can insert/delete a socket with local_port == num 163 */ 164 static int udp_lib_lport_inuse2(struct net *net, __u16 num, 165 struct udp_hslot *hslot2, 166 struct sock *sk) 167 { 168 struct sock *sk2; 169 kuid_t uid = sock_i_uid(sk); 170 int res = 0; 171 172 spin_lock(&hslot2->lock); 173 udp_portaddr_for_each_entry(sk2, &hslot2->head) { 174 if (net_eq(sock_net(sk2), net) && 175 sk2 != sk && 176 (udp_sk(sk2)->udp_port_hash == num) && 177 (!sk2->sk_reuse || !sk->sk_reuse) && 178 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 179 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 180 inet_rcv_saddr_equal(sk, sk2, true)) { 181 if (sk2->sk_reuseport && sk->sk_reuseport && 182 !rcu_access_pointer(sk->sk_reuseport_cb) && 183 uid_eq(uid, sock_i_uid(sk2))) { 184 res = 0; 185 } else { 186 res = 1; 187 } 188 break; 189 } 190 } 191 spin_unlock(&hslot2->lock); 192 return res; 193 } 194 195 static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot) 196 { 197 struct net *net = sock_net(sk); 198 kuid_t uid = sock_i_uid(sk); 199 struct sock *sk2; 200 201 sk_for_each(sk2, &hslot->head) { 202 if (net_eq(sock_net(sk2), net) && 203 sk2 != sk && 204 sk2->sk_family == sk->sk_family && 205 ipv6_only_sock(sk2) == ipv6_only_sock(sk) && 206 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) && 207 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 208 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) && 209 inet_rcv_saddr_equal(sk, sk2, false)) { 210 return reuseport_add_sock(sk, sk2, 211 inet_rcv_saddr_any(sk)); 212 } 213 } 214 215 return reuseport_alloc(sk, inet_rcv_saddr_any(sk)); 216 } 217 218 /** 219 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 220 * 221 * @sk: socket struct in question 222 * @snum: port number to look up 223 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 224 * with NULL address 225 */ 226 int udp_lib_get_port(struct sock *sk, unsigned short snum, 227 unsigned int hash2_nulladdr) 228 { 229 struct udp_hslot *hslot, *hslot2; 230 struct udp_table *udptable = sk->sk_prot->h.udp_table; 231 int error = 1; 232 struct net *net = sock_net(sk); 233 234 if (!snum) { 235 int low, high, remaining; 236 unsigned int rand; 237 unsigned short first, last; 238 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 239 240 inet_get_local_port_range(net, &low, &high); 241 remaining = (high - low) + 1; 242 243 rand = prandom_u32(); 244 first = reciprocal_scale(rand, remaining) + low; 245 /* 246 * force rand to be an odd multiple of UDP_HTABLE_SIZE 247 */ 248 rand = (rand | 1) * (udptable->mask + 1); 249 last = first + udptable->mask + 1; 250 do { 251 hslot = udp_hashslot(udptable, net, first); 252 bitmap_zero(bitmap, PORTS_PER_CHAIN); 253 spin_lock_bh(&hslot->lock); 254 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 255 udptable->log); 256 257 snum = first; 258 /* 259 * Iterate on all possible values of snum for this hash. 260 * Using steps of an odd multiple of UDP_HTABLE_SIZE 261 * give us randomization and full range coverage. 262 */ 263 do { 264 if (low <= snum && snum <= high && 265 !test_bit(snum >> udptable->log, bitmap) && 266 !inet_is_local_reserved_port(net, snum)) 267 goto found; 268 snum += rand; 269 } while (snum != first); 270 spin_unlock_bh(&hslot->lock); 271 cond_resched(); 272 } while (++first != last); 273 goto fail; 274 } else { 275 hslot = udp_hashslot(udptable, net, snum); 276 spin_lock_bh(&hslot->lock); 277 if (hslot->count > 10) { 278 int exist; 279 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 280 281 slot2 &= udptable->mask; 282 hash2_nulladdr &= udptable->mask; 283 284 hslot2 = udp_hashslot2(udptable, slot2); 285 if (hslot->count < hslot2->count) 286 goto scan_primary_hash; 287 288 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk); 289 if (!exist && (hash2_nulladdr != slot2)) { 290 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 291 exist = udp_lib_lport_inuse2(net, snum, hslot2, 292 sk); 293 } 294 if (exist) 295 goto fail_unlock; 296 else 297 goto found; 298 } 299 scan_primary_hash: 300 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0)) 301 goto fail_unlock; 302 } 303 found: 304 inet_sk(sk)->inet_num = snum; 305 udp_sk(sk)->udp_port_hash = snum; 306 udp_sk(sk)->udp_portaddr_hash ^= snum; 307 if (sk_unhashed(sk)) { 308 if (sk->sk_reuseport && 309 udp_reuseport_add_sock(sk, hslot)) { 310 inet_sk(sk)->inet_num = 0; 311 udp_sk(sk)->udp_port_hash = 0; 312 udp_sk(sk)->udp_portaddr_hash ^= snum; 313 goto fail_unlock; 314 } 315 316 sk_add_node_rcu(sk, &hslot->head); 317 hslot->count++; 318 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 319 320 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 321 spin_lock(&hslot2->lock); 322 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && 323 sk->sk_family == AF_INET6) 324 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node, 325 &hslot2->head); 326 else 327 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 328 &hslot2->head); 329 hslot2->count++; 330 spin_unlock(&hslot2->lock); 331 } 332 sock_set_flag(sk, SOCK_RCU_FREE); 333 error = 0; 334 fail_unlock: 335 spin_unlock_bh(&hslot->lock); 336 fail: 337 return error; 338 } 339 EXPORT_SYMBOL(udp_lib_get_port); 340 341 int udp_v4_get_port(struct sock *sk, unsigned short snum) 342 { 343 unsigned int hash2_nulladdr = 344 ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 345 unsigned int hash2_partial = 346 ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 347 348 /* precompute partial secondary hash */ 349 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 350 return udp_lib_get_port(sk, snum, hash2_nulladdr); 351 } 352 353 static int compute_score(struct sock *sk, struct net *net, 354 __be32 saddr, __be16 sport, 355 __be32 daddr, unsigned short hnum, 356 int dif, int sdif) 357 { 358 int score; 359 struct inet_sock *inet; 360 bool dev_match; 361 362 if (!net_eq(sock_net(sk), net) || 363 udp_sk(sk)->udp_port_hash != hnum || 364 ipv6_only_sock(sk)) 365 return -1; 366 367 if (sk->sk_rcv_saddr != daddr) 368 return -1; 369 370 score = (sk->sk_family == PF_INET) ? 2 : 1; 371 372 inet = inet_sk(sk); 373 if (inet->inet_daddr) { 374 if (inet->inet_daddr != saddr) 375 return -1; 376 score += 4; 377 } 378 379 if (inet->inet_dport) { 380 if (inet->inet_dport != sport) 381 return -1; 382 score += 4; 383 } 384 385 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, 386 dif, sdif); 387 if (!dev_match) 388 return -1; 389 score += 4; 390 391 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) 392 score++; 393 return score; 394 } 395 396 static u32 udp_ehashfn(const struct net *net, const __be32 laddr, 397 const __u16 lport, const __be32 faddr, 398 const __be16 fport) 399 { 400 static u32 udp_ehash_secret __read_mostly; 401 402 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); 403 404 return __inet_ehashfn(laddr, lport, faddr, fport, 405 udp_ehash_secret + net_hash_mix(net)); 406 } 407 408 /* called with rcu_read_lock() */ 409 static struct sock *udp4_lib_lookup2(struct net *net, 410 __be32 saddr, __be16 sport, 411 __be32 daddr, unsigned int hnum, 412 int dif, int sdif, 413 struct udp_hslot *hslot2, 414 struct sk_buff *skb) 415 { 416 struct sock *sk, *result; 417 int score, badness; 418 u32 hash = 0; 419 420 result = NULL; 421 badness = 0; 422 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 423 score = compute_score(sk, net, saddr, sport, 424 daddr, hnum, dif, sdif); 425 if (score > badness) { 426 if (sk->sk_reuseport && 427 sk->sk_state != TCP_ESTABLISHED) { 428 hash = udp_ehashfn(net, daddr, hnum, 429 saddr, sport); 430 result = reuseport_select_sock(sk, hash, skb, 431 sizeof(struct udphdr)); 432 if (result && !reuseport_has_conns(sk, false)) 433 return result; 434 } 435 badness = score; 436 result = sk; 437 } 438 } 439 return result; 440 } 441 442 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 443 * harder than this. -DaveM 444 */ 445 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 446 __be16 sport, __be32 daddr, __be16 dport, int dif, 447 int sdif, struct udp_table *udptable, struct sk_buff *skb) 448 { 449 struct sock *result; 450 unsigned short hnum = ntohs(dport); 451 unsigned int hash2, slot2; 452 struct udp_hslot *hslot2; 453 454 hash2 = ipv4_portaddr_hash(net, daddr, hnum); 455 slot2 = hash2 & udptable->mask; 456 hslot2 = &udptable->hash2[slot2]; 457 458 result = udp4_lib_lookup2(net, saddr, sport, 459 daddr, hnum, dif, sdif, 460 hslot2, skb); 461 if (!result) { 462 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 463 slot2 = hash2 & udptable->mask; 464 hslot2 = &udptable->hash2[slot2]; 465 466 result = udp4_lib_lookup2(net, saddr, sport, 467 htonl(INADDR_ANY), hnum, dif, sdif, 468 hslot2, skb); 469 } 470 if (IS_ERR(result)) 471 return NULL; 472 return result; 473 } 474 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 475 476 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 477 __be16 sport, __be16 dport, 478 struct udp_table *udptable) 479 { 480 const struct iphdr *iph = ip_hdr(skb); 481 482 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 483 iph->daddr, dport, inet_iif(skb), 484 inet_sdif(skb), udptable, skb); 485 } 486 487 struct sock *udp4_lib_lookup_skb(struct sk_buff *skb, 488 __be16 sport, __be16 dport) 489 { 490 const struct iphdr *iph = ip_hdr(skb); 491 492 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport, 493 iph->daddr, dport, inet_iif(skb), 494 inet_sdif(skb), &udp_table, NULL); 495 } 496 EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb); 497 498 /* Must be called under rcu_read_lock(). 499 * Does increment socket refcount. 500 */ 501 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4) 502 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 503 __be32 daddr, __be16 dport, int dif) 504 { 505 struct sock *sk; 506 507 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport, 508 dif, 0, &udp_table, NULL); 509 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) 510 sk = NULL; 511 return sk; 512 } 513 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 514 #endif 515 516 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, 517 __be16 loc_port, __be32 loc_addr, 518 __be16 rmt_port, __be32 rmt_addr, 519 int dif, int sdif, unsigned short hnum) 520 { 521 struct inet_sock *inet = inet_sk(sk); 522 523 if (!net_eq(sock_net(sk), net) || 524 udp_sk(sk)->udp_port_hash != hnum || 525 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 526 (inet->inet_dport != rmt_port && inet->inet_dport) || 527 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) || 528 ipv6_only_sock(sk) || 529 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif)) 530 return false; 531 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif)) 532 return false; 533 return true; 534 } 535 536 DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key); 537 void udp_encap_enable(void) 538 { 539 static_branch_inc(&udp_encap_needed_key); 540 } 541 EXPORT_SYMBOL(udp_encap_enable); 542 543 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go 544 * through error handlers in encapsulations looking for a match. 545 */ 546 static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info) 547 { 548 int i; 549 550 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { 551 int (*handler)(struct sk_buff *skb, u32 info); 552 const struct ip_tunnel_encap_ops *encap; 553 554 encap = rcu_dereference(iptun_encaps[i]); 555 if (!encap) 556 continue; 557 handler = encap->err_handler; 558 if (handler && !handler(skb, info)) 559 return 0; 560 } 561 562 return -ENOENT; 563 } 564 565 /* Try to match ICMP errors to UDP tunnels by looking up a socket without 566 * reversing source and destination port: this will match tunnels that force the 567 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that 568 * lwtunnels might actually break this assumption by being configured with 569 * different destination ports on endpoints, in this case we won't be able to 570 * trace ICMP messages back to them. 571 * 572 * If this doesn't match any socket, probe tunnels with arbitrary destination 573 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port 574 * we've sent packets to won't necessarily match the local destination port. 575 * 576 * Then ask the tunnel implementation to match the error against a valid 577 * association. 578 * 579 * Return an error if we can't find a match, the socket if we need further 580 * processing, zero otherwise. 581 */ 582 static struct sock *__udp4_lib_err_encap(struct net *net, 583 const struct iphdr *iph, 584 struct udphdr *uh, 585 struct udp_table *udptable, 586 struct sk_buff *skb, u32 info) 587 { 588 int network_offset, transport_offset; 589 struct sock *sk; 590 591 network_offset = skb_network_offset(skb); 592 transport_offset = skb_transport_offset(skb); 593 594 /* Network header needs to point to the outer IPv4 header inside ICMP */ 595 skb_reset_network_header(skb); 596 597 /* Transport header needs to point to the UDP header */ 598 skb_set_transport_header(skb, iph->ihl << 2); 599 600 sk = __udp4_lib_lookup(net, iph->daddr, uh->source, 601 iph->saddr, uh->dest, skb->dev->ifindex, 0, 602 udptable, NULL); 603 if (sk) { 604 int (*lookup)(struct sock *sk, struct sk_buff *skb); 605 struct udp_sock *up = udp_sk(sk); 606 607 lookup = READ_ONCE(up->encap_err_lookup); 608 if (!lookup || lookup(sk, skb)) 609 sk = NULL; 610 } 611 612 if (!sk) 613 sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info)); 614 615 skb_set_transport_header(skb, transport_offset); 616 skb_set_network_header(skb, network_offset); 617 618 return sk; 619 } 620 621 /* 622 * This routine is called by the ICMP module when it gets some 623 * sort of error condition. If err < 0 then the socket should 624 * be closed and the error returned to the user. If err > 0 625 * it's just the icmp type << 8 | icmp code. 626 * Header points to the ip header of the error packet. We move 627 * on past this. Then (as it used to claim before adjustment) 628 * header points to the first 8 bytes of the udp header. We need 629 * to find the appropriate port. 630 */ 631 632 int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 633 { 634 struct inet_sock *inet; 635 const struct iphdr *iph = (const struct iphdr *)skb->data; 636 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 637 const int type = icmp_hdr(skb)->type; 638 const int code = icmp_hdr(skb)->code; 639 bool tunnel = false; 640 struct sock *sk; 641 int harderr; 642 int err; 643 struct net *net = dev_net(skb->dev); 644 645 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 646 iph->saddr, uh->source, skb->dev->ifindex, 647 inet_sdif(skb), udptable, NULL); 648 if (!sk) { 649 /* No socket for error: try tunnels before discarding */ 650 sk = ERR_PTR(-ENOENT); 651 if (static_branch_unlikely(&udp_encap_needed_key)) { 652 sk = __udp4_lib_err_encap(net, iph, uh, udptable, skb, 653 info); 654 if (!sk) 655 return 0; 656 } 657 658 if (IS_ERR(sk)) { 659 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); 660 return PTR_ERR(sk); 661 } 662 663 tunnel = true; 664 } 665 666 err = 0; 667 harderr = 0; 668 inet = inet_sk(sk); 669 670 switch (type) { 671 default: 672 case ICMP_TIME_EXCEEDED: 673 err = EHOSTUNREACH; 674 break; 675 case ICMP_SOURCE_QUENCH: 676 goto out; 677 case ICMP_PARAMETERPROB: 678 err = EPROTO; 679 harderr = 1; 680 break; 681 case ICMP_DEST_UNREACH: 682 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 683 ipv4_sk_update_pmtu(skb, sk, info); 684 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 685 err = EMSGSIZE; 686 harderr = 1; 687 break; 688 } 689 goto out; 690 } 691 err = EHOSTUNREACH; 692 if (code <= NR_ICMP_UNREACH) { 693 harderr = icmp_err_convert[code].fatal; 694 err = icmp_err_convert[code].errno; 695 } 696 break; 697 case ICMP_REDIRECT: 698 ipv4_sk_redirect(skb, sk); 699 goto out; 700 } 701 702 /* 703 * RFC1122: OK. Passes ICMP errors back to application, as per 704 * 4.1.3.3. 705 */ 706 if (tunnel) { 707 /* ...not for tunnels though: we don't have a sending socket */ 708 goto out; 709 } 710 if (!inet->recverr) { 711 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 712 goto out; 713 } else 714 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 715 716 sk->sk_err = err; 717 sk->sk_error_report(sk); 718 out: 719 return 0; 720 } 721 722 int udp_err(struct sk_buff *skb, u32 info) 723 { 724 return __udp4_lib_err(skb, info, &udp_table); 725 } 726 727 /* 728 * Throw away all pending data and cancel the corking. Socket is locked. 729 */ 730 void udp_flush_pending_frames(struct sock *sk) 731 { 732 struct udp_sock *up = udp_sk(sk); 733 734 if (up->pending) { 735 up->len = 0; 736 up->pending = 0; 737 ip_flush_pending_frames(sk); 738 } 739 } 740 EXPORT_SYMBOL(udp_flush_pending_frames); 741 742 /** 743 * udp4_hwcsum - handle outgoing HW checksumming 744 * @skb: sk_buff containing the filled-in UDP header 745 * (checksum field must be zeroed out) 746 * @src: source IP address 747 * @dst: destination IP address 748 */ 749 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 750 { 751 struct udphdr *uh = udp_hdr(skb); 752 int offset = skb_transport_offset(skb); 753 int len = skb->len - offset; 754 int hlen = len; 755 __wsum csum = 0; 756 757 if (!skb_has_frag_list(skb)) { 758 /* 759 * Only one fragment on the socket. 760 */ 761 skb->csum_start = skb_transport_header(skb) - skb->head; 762 skb->csum_offset = offsetof(struct udphdr, check); 763 uh->check = ~csum_tcpudp_magic(src, dst, len, 764 IPPROTO_UDP, 0); 765 } else { 766 struct sk_buff *frags; 767 768 /* 769 * HW-checksum won't work as there are two or more 770 * fragments on the socket so that all csums of sk_buffs 771 * should be together 772 */ 773 skb_walk_frags(skb, frags) { 774 csum = csum_add(csum, frags->csum); 775 hlen -= frags->len; 776 } 777 778 csum = skb_checksum(skb, offset, hlen, csum); 779 skb->ip_summed = CHECKSUM_NONE; 780 781 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 782 if (uh->check == 0) 783 uh->check = CSUM_MANGLED_0; 784 } 785 } 786 EXPORT_SYMBOL_GPL(udp4_hwcsum); 787 788 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended 789 * for the simple case like when setting the checksum for a UDP tunnel. 790 */ 791 void udp_set_csum(bool nocheck, struct sk_buff *skb, 792 __be32 saddr, __be32 daddr, int len) 793 { 794 struct udphdr *uh = udp_hdr(skb); 795 796 if (nocheck) { 797 uh->check = 0; 798 } else if (skb_is_gso(skb)) { 799 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 800 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { 801 uh->check = 0; 802 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb)); 803 if (uh->check == 0) 804 uh->check = CSUM_MANGLED_0; 805 } else { 806 skb->ip_summed = CHECKSUM_PARTIAL; 807 skb->csum_start = skb_transport_header(skb) - skb->head; 808 skb->csum_offset = offsetof(struct udphdr, check); 809 uh->check = ~udp_v4_check(len, saddr, daddr, 0); 810 } 811 } 812 EXPORT_SYMBOL(udp_set_csum); 813 814 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4, 815 struct inet_cork *cork) 816 { 817 struct sock *sk = skb->sk; 818 struct inet_sock *inet = inet_sk(sk); 819 struct udphdr *uh; 820 int err = 0; 821 int is_udplite = IS_UDPLITE(sk); 822 int offset = skb_transport_offset(skb); 823 int len = skb->len - offset; 824 int datalen = len - sizeof(*uh); 825 __wsum csum = 0; 826 827 /* 828 * Create a UDP header 829 */ 830 uh = udp_hdr(skb); 831 uh->source = inet->inet_sport; 832 uh->dest = fl4->fl4_dport; 833 uh->len = htons(len); 834 uh->check = 0; 835 836 if (cork->gso_size) { 837 const int hlen = skb_network_header_len(skb) + 838 sizeof(struct udphdr); 839 840 if (hlen + cork->gso_size > cork->fragsize) { 841 kfree_skb(skb); 842 return -EINVAL; 843 } 844 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) { 845 kfree_skb(skb); 846 return -EINVAL; 847 } 848 if (sk->sk_no_check_tx) { 849 kfree_skb(skb); 850 return -EINVAL; 851 } 852 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || 853 dst_xfrm(skb_dst(skb))) { 854 kfree_skb(skb); 855 return -EIO; 856 } 857 858 if (datalen > cork->gso_size) { 859 skb_shinfo(skb)->gso_size = cork->gso_size; 860 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; 861 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, 862 cork->gso_size); 863 } 864 goto csum_partial; 865 } 866 867 if (is_udplite) /* UDP-Lite */ 868 csum = udplite_csum(skb); 869 870 else if (sk->sk_no_check_tx) { /* UDP csum off */ 871 872 skb->ip_summed = CHECKSUM_NONE; 873 goto send; 874 875 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 876 csum_partial: 877 878 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 879 goto send; 880 881 } else 882 csum = udp_csum(skb); 883 884 /* add protocol-dependent pseudo-header */ 885 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 886 sk->sk_protocol, csum); 887 if (uh->check == 0) 888 uh->check = CSUM_MANGLED_0; 889 890 send: 891 err = ip_send_skb(sock_net(sk), skb); 892 if (err) { 893 if (err == -ENOBUFS && !inet->recverr) { 894 UDP_INC_STATS(sock_net(sk), 895 UDP_MIB_SNDBUFERRORS, is_udplite); 896 err = 0; 897 } 898 } else 899 UDP_INC_STATS(sock_net(sk), 900 UDP_MIB_OUTDATAGRAMS, is_udplite); 901 return err; 902 } 903 904 /* 905 * Push out all pending data as one UDP datagram. Socket is locked. 906 */ 907 int udp_push_pending_frames(struct sock *sk) 908 { 909 struct udp_sock *up = udp_sk(sk); 910 struct inet_sock *inet = inet_sk(sk); 911 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 912 struct sk_buff *skb; 913 int err = 0; 914 915 skb = ip_finish_skb(sk, fl4); 916 if (!skb) 917 goto out; 918 919 err = udp_send_skb(skb, fl4, &inet->cork.base); 920 921 out: 922 up->len = 0; 923 up->pending = 0; 924 return err; 925 } 926 EXPORT_SYMBOL(udp_push_pending_frames); 927 928 static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size) 929 { 930 switch (cmsg->cmsg_type) { 931 case UDP_SEGMENT: 932 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16))) 933 return -EINVAL; 934 *gso_size = *(__u16 *)CMSG_DATA(cmsg); 935 return 0; 936 default: 937 return -EINVAL; 938 } 939 } 940 941 int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size) 942 { 943 struct cmsghdr *cmsg; 944 bool need_ip = false; 945 int err; 946 947 for_each_cmsghdr(cmsg, msg) { 948 if (!CMSG_OK(msg, cmsg)) 949 return -EINVAL; 950 951 if (cmsg->cmsg_level != SOL_UDP) { 952 need_ip = true; 953 continue; 954 } 955 956 err = __udp_cmsg_send(cmsg, gso_size); 957 if (err) 958 return err; 959 } 960 961 return need_ip; 962 } 963 EXPORT_SYMBOL_GPL(udp_cmsg_send); 964 965 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 966 { 967 struct inet_sock *inet = inet_sk(sk); 968 struct udp_sock *up = udp_sk(sk); 969 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 970 struct flowi4 fl4_stack; 971 struct flowi4 *fl4; 972 int ulen = len; 973 struct ipcm_cookie ipc; 974 struct rtable *rt = NULL; 975 int free = 0; 976 int connected = 0; 977 __be32 daddr, faddr, saddr; 978 __be16 dport; 979 u8 tos; 980 int err, is_udplite = IS_UDPLITE(sk); 981 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 982 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 983 struct sk_buff *skb; 984 struct ip_options_data opt_copy; 985 986 if (len > 0xFFFF) 987 return -EMSGSIZE; 988 989 /* 990 * Check the flags. 991 */ 992 993 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 994 return -EOPNOTSUPP; 995 996 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 997 998 fl4 = &inet->cork.fl.u.ip4; 999 if (up->pending) { 1000 /* 1001 * There are pending frames. 1002 * The socket lock must be held while it's corked. 1003 */ 1004 lock_sock(sk); 1005 if (likely(up->pending)) { 1006 if (unlikely(up->pending != AF_INET)) { 1007 release_sock(sk); 1008 return -EINVAL; 1009 } 1010 goto do_append_data; 1011 } 1012 release_sock(sk); 1013 } 1014 ulen += sizeof(struct udphdr); 1015 1016 /* 1017 * Get and verify the address. 1018 */ 1019 if (usin) { 1020 if (msg->msg_namelen < sizeof(*usin)) 1021 return -EINVAL; 1022 if (usin->sin_family != AF_INET) { 1023 if (usin->sin_family != AF_UNSPEC) 1024 return -EAFNOSUPPORT; 1025 } 1026 1027 daddr = usin->sin_addr.s_addr; 1028 dport = usin->sin_port; 1029 if (dport == 0) 1030 return -EINVAL; 1031 } else { 1032 if (sk->sk_state != TCP_ESTABLISHED) 1033 return -EDESTADDRREQ; 1034 daddr = inet->inet_daddr; 1035 dport = inet->inet_dport; 1036 /* Open fast path for connected socket. 1037 Route will not be used, if at least one option is set. 1038 */ 1039 connected = 1; 1040 } 1041 1042 ipcm_init_sk(&ipc, inet); 1043 ipc.gso_size = up->gso_size; 1044 1045 if (msg->msg_controllen) { 1046 err = udp_cmsg_send(sk, msg, &ipc.gso_size); 1047 if (err > 0) 1048 err = ip_cmsg_send(sk, msg, &ipc, 1049 sk->sk_family == AF_INET6); 1050 if (unlikely(err < 0)) { 1051 kfree(ipc.opt); 1052 return err; 1053 } 1054 if (ipc.opt) 1055 free = 1; 1056 connected = 0; 1057 } 1058 if (!ipc.opt) { 1059 struct ip_options_rcu *inet_opt; 1060 1061 rcu_read_lock(); 1062 inet_opt = rcu_dereference(inet->inet_opt); 1063 if (inet_opt) { 1064 memcpy(&opt_copy, inet_opt, 1065 sizeof(*inet_opt) + inet_opt->opt.optlen); 1066 ipc.opt = &opt_copy.opt; 1067 } 1068 rcu_read_unlock(); 1069 } 1070 1071 if (cgroup_bpf_enabled && !connected) { 1072 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, 1073 (struct sockaddr *)usin, &ipc.addr); 1074 if (err) 1075 goto out_free; 1076 if (usin) { 1077 if (usin->sin_port == 0) { 1078 /* BPF program set invalid port. Reject it. */ 1079 err = -EINVAL; 1080 goto out_free; 1081 } 1082 daddr = usin->sin_addr.s_addr; 1083 dport = usin->sin_port; 1084 } 1085 } 1086 1087 saddr = ipc.addr; 1088 ipc.addr = faddr = daddr; 1089 1090 if (ipc.opt && ipc.opt->opt.srr) { 1091 if (!daddr) { 1092 err = -EINVAL; 1093 goto out_free; 1094 } 1095 faddr = ipc.opt->opt.faddr; 1096 connected = 0; 1097 } 1098 tos = get_rttos(&ipc, inet); 1099 if (sock_flag(sk, SOCK_LOCALROUTE) || 1100 (msg->msg_flags & MSG_DONTROUTE) || 1101 (ipc.opt && ipc.opt->opt.is_strictroute)) { 1102 tos |= RTO_ONLINK; 1103 connected = 0; 1104 } 1105 1106 if (ipv4_is_multicast(daddr)) { 1107 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 1108 ipc.oif = inet->mc_index; 1109 if (!saddr) 1110 saddr = inet->mc_addr; 1111 connected = 0; 1112 } else if (!ipc.oif) { 1113 ipc.oif = inet->uc_index; 1114 } else if (ipv4_is_lbcast(daddr) && inet->uc_index) { 1115 /* oif is set, packet is to local broadcast and 1116 * and uc_index is set. oif is most likely set 1117 * by sk_bound_dev_if. If uc_index != oif check if the 1118 * oif is an L3 master and uc_index is an L3 slave. 1119 * If so, we want to allow the send using the uc_index. 1120 */ 1121 if (ipc.oif != inet->uc_index && 1122 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk), 1123 inet->uc_index)) { 1124 ipc.oif = inet->uc_index; 1125 } 1126 } 1127 1128 if (connected) 1129 rt = (struct rtable *)sk_dst_check(sk, 0); 1130 1131 if (!rt) { 1132 struct net *net = sock_net(sk); 1133 __u8 flow_flags = inet_sk_flowi_flags(sk); 1134 1135 fl4 = &fl4_stack; 1136 1137 flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos, 1138 RT_SCOPE_UNIVERSE, sk->sk_protocol, 1139 flow_flags, 1140 faddr, saddr, dport, inet->inet_sport, 1141 sk->sk_uid); 1142 1143 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 1144 rt = ip_route_output_flow(net, fl4, sk); 1145 if (IS_ERR(rt)) { 1146 err = PTR_ERR(rt); 1147 rt = NULL; 1148 if (err == -ENETUNREACH) 1149 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 1150 goto out; 1151 } 1152 1153 err = -EACCES; 1154 if ((rt->rt_flags & RTCF_BROADCAST) && 1155 !sock_flag(sk, SOCK_BROADCAST)) 1156 goto out; 1157 if (connected) 1158 sk_dst_set(sk, dst_clone(&rt->dst)); 1159 } 1160 1161 if (msg->msg_flags&MSG_CONFIRM) 1162 goto do_confirm; 1163 back_from_confirm: 1164 1165 saddr = fl4->saddr; 1166 if (!ipc.addr) 1167 daddr = ipc.addr = fl4->daddr; 1168 1169 /* Lockless fast path for the non-corking case. */ 1170 if (!corkreq) { 1171 struct inet_cork cork; 1172 1173 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen, 1174 sizeof(struct udphdr), &ipc, &rt, 1175 &cork, msg->msg_flags); 1176 err = PTR_ERR(skb); 1177 if (!IS_ERR_OR_NULL(skb)) 1178 err = udp_send_skb(skb, fl4, &cork); 1179 goto out; 1180 } 1181 1182 lock_sock(sk); 1183 if (unlikely(up->pending)) { 1184 /* The socket is already corked while preparing it. */ 1185 /* ... which is an evident application bug. --ANK */ 1186 release_sock(sk); 1187 1188 net_dbg_ratelimited("socket already corked\n"); 1189 err = -EINVAL; 1190 goto out; 1191 } 1192 /* 1193 * Now cork the socket to pend data. 1194 */ 1195 fl4 = &inet->cork.fl.u.ip4; 1196 fl4->daddr = daddr; 1197 fl4->saddr = saddr; 1198 fl4->fl4_dport = dport; 1199 fl4->fl4_sport = inet->inet_sport; 1200 up->pending = AF_INET; 1201 1202 do_append_data: 1203 up->len += ulen; 1204 err = ip_append_data(sk, fl4, getfrag, msg, ulen, 1205 sizeof(struct udphdr), &ipc, &rt, 1206 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1207 if (err) 1208 udp_flush_pending_frames(sk); 1209 else if (!corkreq) 1210 err = udp_push_pending_frames(sk); 1211 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1212 up->pending = 0; 1213 release_sock(sk); 1214 1215 out: 1216 ip_rt_put(rt); 1217 out_free: 1218 if (free) 1219 kfree(ipc.opt); 1220 if (!err) 1221 return len; 1222 /* 1223 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1224 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1225 * we don't have a good statistic (IpOutDiscards but it can be too many 1226 * things). We could add another new stat but at least for now that 1227 * seems like overkill. 1228 */ 1229 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1230 UDP_INC_STATS(sock_net(sk), 1231 UDP_MIB_SNDBUFERRORS, is_udplite); 1232 } 1233 return err; 1234 1235 do_confirm: 1236 if (msg->msg_flags & MSG_PROBE) 1237 dst_confirm_neigh(&rt->dst, &fl4->daddr); 1238 if (!(msg->msg_flags&MSG_PROBE) || len) 1239 goto back_from_confirm; 1240 err = 0; 1241 goto out; 1242 } 1243 EXPORT_SYMBOL(udp_sendmsg); 1244 1245 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1246 size_t size, int flags) 1247 { 1248 struct inet_sock *inet = inet_sk(sk); 1249 struct udp_sock *up = udp_sk(sk); 1250 int ret; 1251 1252 if (flags & MSG_SENDPAGE_NOTLAST) 1253 flags |= MSG_MORE; 1254 1255 if (!up->pending) { 1256 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1257 1258 /* Call udp_sendmsg to specify destination address which 1259 * sendpage interface can't pass. 1260 * This will succeed only when the socket is connected. 1261 */ 1262 ret = udp_sendmsg(sk, &msg, 0); 1263 if (ret < 0) 1264 return ret; 1265 } 1266 1267 lock_sock(sk); 1268 1269 if (unlikely(!up->pending)) { 1270 release_sock(sk); 1271 1272 net_dbg_ratelimited("cork failed\n"); 1273 return -EINVAL; 1274 } 1275 1276 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1277 page, offset, size, flags); 1278 if (ret == -EOPNOTSUPP) { 1279 release_sock(sk); 1280 return sock_no_sendpage(sk->sk_socket, page, offset, 1281 size, flags); 1282 } 1283 if (ret < 0) { 1284 udp_flush_pending_frames(sk); 1285 goto out; 1286 } 1287 1288 up->len += size; 1289 if (!(up->corkflag || (flags&MSG_MORE))) 1290 ret = udp_push_pending_frames(sk); 1291 if (!ret) 1292 ret = size; 1293 out: 1294 release_sock(sk); 1295 return ret; 1296 } 1297 1298 #define UDP_SKB_IS_STATELESS 0x80000000 1299 1300 /* all head states (dst, sk, nf conntrack) except skb extensions are 1301 * cleared by udp_rcv(). 1302 * 1303 * We need to preserve secpath, if present, to eventually process 1304 * IP_CMSG_PASSSEC at recvmsg() time. 1305 * 1306 * Other extensions can be cleared. 1307 */ 1308 static bool udp_try_make_stateless(struct sk_buff *skb) 1309 { 1310 if (!skb_has_extensions(skb)) 1311 return true; 1312 1313 if (!secpath_exists(skb)) { 1314 skb_ext_reset(skb); 1315 return true; 1316 } 1317 1318 return false; 1319 } 1320 1321 static void udp_set_dev_scratch(struct sk_buff *skb) 1322 { 1323 struct udp_dev_scratch *scratch = udp_skb_scratch(skb); 1324 1325 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long)); 1326 scratch->_tsize_state = skb->truesize; 1327 #if BITS_PER_LONG == 64 1328 scratch->len = skb->len; 1329 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb); 1330 scratch->is_linear = !skb_is_nonlinear(skb); 1331 #endif 1332 if (udp_try_make_stateless(skb)) 1333 scratch->_tsize_state |= UDP_SKB_IS_STATELESS; 1334 } 1335 1336 static void udp_skb_csum_unnecessary_set(struct sk_buff *skb) 1337 { 1338 /* We come here after udp_lib_checksum_complete() returned 0. 1339 * This means that __skb_checksum_complete() might have 1340 * set skb->csum_valid to 1. 1341 * On 64bit platforms, we can set csum_unnecessary 1342 * to true, but only if the skb is not shared. 1343 */ 1344 #if BITS_PER_LONG == 64 1345 if (!skb_shared(skb)) 1346 udp_skb_scratch(skb)->csum_unnecessary = true; 1347 #endif 1348 } 1349 1350 static int udp_skb_truesize(struct sk_buff *skb) 1351 { 1352 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS; 1353 } 1354 1355 static bool udp_skb_has_head_state(struct sk_buff *skb) 1356 { 1357 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS); 1358 } 1359 1360 /* fully reclaim rmem/fwd memory allocated for skb */ 1361 static void udp_rmem_release(struct sock *sk, int size, int partial, 1362 bool rx_queue_lock_held) 1363 { 1364 struct udp_sock *up = udp_sk(sk); 1365 struct sk_buff_head *sk_queue; 1366 int amt; 1367 1368 if (likely(partial)) { 1369 up->forward_deficit += size; 1370 size = up->forward_deficit; 1371 if (size < (sk->sk_rcvbuf >> 2)) 1372 return; 1373 } else { 1374 size += up->forward_deficit; 1375 } 1376 up->forward_deficit = 0; 1377 1378 /* acquire the sk_receive_queue for fwd allocated memory scheduling, 1379 * if the called don't held it already 1380 */ 1381 sk_queue = &sk->sk_receive_queue; 1382 if (!rx_queue_lock_held) 1383 spin_lock(&sk_queue->lock); 1384 1385 1386 sk->sk_forward_alloc += size; 1387 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1); 1388 sk->sk_forward_alloc -= amt; 1389 1390 if (amt) 1391 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT); 1392 1393 atomic_sub(size, &sk->sk_rmem_alloc); 1394 1395 /* this can save us from acquiring the rx queue lock on next receive */ 1396 skb_queue_splice_tail_init(sk_queue, &up->reader_queue); 1397 1398 if (!rx_queue_lock_held) 1399 spin_unlock(&sk_queue->lock); 1400 } 1401 1402 /* Note: called with reader_queue.lock held. 1403 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch 1404 * This avoids a cache line miss while receive_queue lock is held. 1405 * Look at __udp_enqueue_schedule_skb() to find where this copy is done. 1406 */ 1407 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb) 1408 { 1409 prefetch(&skb->data); 1410 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false); 1411 } 1412 EXPORT_SYMBOL(udp_skb_destructor); 1413 1414 /* as above, but the caller held the rx queue lock, too */ 1415 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb) 1416 { 1417 prefetch(&skb->data); 1418 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true); 1419 } 1420 1421 /* Idea of busylocks is to let producers grab an extra spinlock 1422 * to relieve pressure on the receive_queue spinlock shared by consumer. 1423 * Under flood, this means that only one producer can be in line 1424 * trying to acquire the receive_queue spinlock. 1425 * These busylock can be allocated on a per cpu manner, instead of a 1426 * per socket one (that would consume a cache line per socket) 1427 */ 1428 static int udp_busylocks_log __read_mostly; 1429 static spinlock_t *udp_busylocks __read_mostly; 1430 1431 static spinlock_t *busylock_acquire(void *ptr) 1432 { 1433 spinlock_t *busy; 1434 1435 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log); 1436 spin_lock(busy); 1437 return busy; 1438 } 1439 1440 static void busylock_release(spinlock_t *busy) 1441 { 1442 if (busy) 1443 spin_unlock(busy); 1444 } 1445 1446 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) 1447 { 1448 struct sk_buff_head *list = &sk->sk_receive_queue; 1449 int rmem, delta, amt, err = -ENOMEM; 1450 spinlock_t *busy = NULL; 1451 int size; 1452 1453 /* try to avoid the costly atomic add/sub pair when the receive 1454 * queue is full; always allow at least a packet 1455 */ 1456 rmem = atomic_read(&sk->sk_rmem_alloc); 1457 if (rmem > sk->sk_rcvbuf) 1458 goto drop; 1459 1460 /* Under mem pressure, it might be helpful to help udp_recvmsg() 1461 * having linear skbs : 1462 * - Reduce memory overhead and thus increase receive queue capacity 1463 * - Less cache line misses at copyout() time 1464 * - Less work at consume_skb() (less alien page frag freeing) 1465 */ 1466 if (rmem > (sk->sk_rcvbuf >> 1)) { 1467 skb_condense(skb); 1468 1469 busy = busylock_acquire(sk); 1470 } 1471 size = skb->truesize; 1472 udp_set_dev_scratch(skb); 1473 1474 /* we drop only if the receive buf is full and the receive 1475 * queue contains some other skb 1476 */ 1477 rmem = atomic_add_return(size, &sk->sk_rmem_alloc); 1478 if (rmem > (size + sk->sk_rcvbuf)) 1479 goto uncharge_drop; 1480 1481 spin_lock(&list->lock); 1482 if (size >= sk->sk_forward_alloc) { 1483 amt = sk_mem_pages(size); 1484 delta = amt << SK_MEM_QUANTUM_SHIFT; 1485 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) { 1486 err = -ENOBUFS; 1487 spin_unlock(&list->lock); 1488 goto uncharge_drop; 1489 } 1490 1491 sk->sk_forward_alloc += delta; 1492 } 1493 1494 sk->sk_forward_alloc -= size; 1495 1496 /* no need to setup a destructor, we will explicitly release the 1497 * forward allocated memory on dequeue 1498 */ 1499 sock_skb_set_dropcount(sk, skb); 1500 1501 __skb_queue_tail(list, skb); 1502 spin_unlock(&list->lock); 1503 1504 if (!sock_flag(sk, SOCK_DEAD)) 1505 sk->sk_data_ready(sk); 1506 1507 busylock_release(busy); 1508 return 0; 1509 1510 uncharge_drop: 1511 atomic_sub(skb->truesize, &sk->sk_rmem_alloc); 1512 1513 drop: 1514 atomic_inc(&sk->sk_drops); 1515 busylock_release(busy); 1516 return err; 1517 } 1518 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb); 1519 1520 void udp_destruct_sock(struct sock *sk) 1521 { 1522 /* reclaim completely the forward allocated memory */ 1523 struct udp_sock *up = udp_sk(sk); 1524 unsigned int total = 0; 1525 struct sk_buff *skb; 1526 1527 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue); 1528 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) { 1529 total += skb->truesize; 1530 kfree_skb(skb); 1531 } 1532 udp_rmem_release(sk, total, 0, true); 1533 1534 inet_sock_destruct(sk); 1535 } 1536 EXPORT_SYMBOL_GPL(udp_destruct_sock); 1537 1538 int udp_init_sock(struct sock *sk) 1539 { 1540 skb_queue_head_init(&udp_sk(sk)->reader_queue); 1541 sk->sk_destruct = udp_destruct_sock; 1542 return 0; 1543 } 1544 EXPORT_SYMBOL_GPL(udp_init_sock); 1545 1546 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) 1547 { 1548 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) { 1549 bool slow = lock_sock_fast(sk); 1550 1551 sk_peek_offset_bwd(sk, len); 1552 unlock_sock_fast(sk, slow); 1553 } 1554 1555 if (!skb_unref(skb)) 1556 return; 1557 1558 /* In the more common cases we cleared the head states previously, 1559 * see __udp_queue_rcv_skb(). 1560 */ 1561 if (unlikely(udp_skb_has_head_state(skb))) 1562 skb_release_head_state(skb); 1563 __consume_stateless_skb(skb); 1564 } 1565 EXPORT_SYMBOL_GPL(skb_consume_udp); 1566 1567 static struct sk_buff *__first_packet_length(struct sock *sk, 1568 struct sk_buff_head *rcvq, 1569 int *total) 1570 { 1571 struct sk_buff *skb; 1572 1573 while ((skb = skb_peek(rcvq)) != NULL) { 1574 if (udp_lib_checksum_complete(skb)) { 1575 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, 1576 IS_UDPLITE(sk)); 1577 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, 1578 IS_UDPLITE(sk)); 1579 atomic_inc(&sk->sk_drops); 1580 __skb_unlink(skb, rcvq); 1581 *total += skb->truesize; 1582 kfree_skb(skb); 1583 } else { 1584 udp_skb_csum_unnecessary_set(skb); 1585 break; 1586 } 1587 } 1588 return skb; 1589 } 1590 1591 /** 1592 * first_packet_length - return length of first packet in receive queue 1593 * @sk: socket 1594 * 1595 * Drops all bad checksum frames, until a valid one is found. 1596 * Returns the length of found skb, or -1 if none is found. 1597 */ 1598 static int first_packet_length(struct sock *sk) 1599 { 1600 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue; 1601 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1602 struct sk_buff *skb; 1603 int total = 0; 1604 int res; 1605 1606 spin_lock_bh(&rcvq->lock); 1607 skb = __first_packet_length(sk, rcvq, &total); 1608 if (!skb && !skb_queue_empty_lockless(sk_queue)) { 1609 spin_lock(&sk_queue->lock); 1610 skb_queue_splice_tail_init(sk_queue, rcvq); 1611 spin_unlock(&sk_queue->lock); 1612 1613 skb = __first_packet_length(sk, rcvq, &total); 1614 } 1615 res = skb ? skb->len : -1; 1616 if (total) 1617 udp_rmem_release(sk, total, 1, false); 1618 spin_unlock_bh(&rcvq->lock); 1619 return res; 1620 } 1621 1622 /* 1623 * IOCTL requests applicable to the UDP protocol 1624 */ 1625 1626 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1627 { 1628 switch (cmd) { 1629 case SIOCOUTQ: 1630 { 1631 int amount = sk_wmem_alloc_get(sk); 1632 1633 return put_user(amount, (int __user *)arg); 1634 } 1635 1636 case SIOCINQ: 1637 { 1638 int amount = max_t(int, 0, first_packet_length(sk)); 1639 1640 return put_user(amount, (int __user *)arg); 1641 } 1642 1643 default: 1644 return -ENOIOCTLCMD; 1645 } 1646 1647 return 0; 1648 } 1649 EXPORT_SYMBOL(udp_ioctl); 1650 1651 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, 1652 int noblock, int *off, int *err) 1653 { 1654 struct sk_buff_head *sk_queue = &sk->sk_receive_queue; 1655 struct sk_buff_head *queue; 1656 struct sk_buff *last; 1657 long timeo; 1658 int error; 1659 1660 queue = &udp_sk(sk)->reader_queue; 1661 flags |= noblock ? MSG_DONTWAIT : 0; 1662 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 1663 do { 1664 struct sk_buff *skb; 1665 1666 error = sock_error(sk); 1667 if (error) 1668 break; 1669 1670 error = -EAGAIN; 1671 do { 1672 spin_lock_bh(&queue->lock); 1673 skb = __skb_try_recv_from_queue(sk, queue, flags, 1674 udp_skb_destructor, 1675 off, err, &last); 1676 if (skb) { 1677 spin_unlock_bh(&queue->lock); 1678 return skb; 1679 } 1680 1681 if (skb_queue_empty_lockless(sk_queue)) { 1682 spin_unlock_bh(&queue->lock); 1683 goto busy_check; 1684 } 1685 1686 /* refill the reader queue and walk it again 1687 * keep both queues locked to avoid re-acquiring 1688 * the sk_receive_queue lock if fwd memory scheduling 1689 * is needed. 1690 */ 1691 spin_lock(&sk_queue->lock); 1692 skb_queue_splice_tail_init(sk_queue, queue); 1693 1694 skb = __skb_try_recv_from_queue(sk, queue, flags, 1695 udp_skb_dtor_locked, 1696 off, err, &last); 1697 spin_unlock(&sk_queue->lock); 1698 spin_unlock_bh(&queue->lock); 1699 if (skb) 1700 return skb; 1701 1702 busy_check: 1703 if (!sk_can_busy_loop(sk)) 1704 break; 1705 1706 sk_busy_loop(sk, flags & MSG_DONTWAIT); 1707 } while (!skb_queue_empty_lockless(sk_queue)); 1708 1709 /* sk_queue is empty, reader_queue may contain peeked packets */ 1710 } while (timeo && 1711 !__skb_wait_for_more_packets(sk, &error, &timeo, 1712 (struct sk_buff *)sk_queue)); 1713 1714 *err = error; 1715 return NULL; 1716 } 1717 EXPORT_SYMBOL(__skb_recv_udp); 1718 1719 /* 1720 * This should be easy, if there is something there we 1721 * return it, otherwise we block. 1722 */ 1723 1724 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 1725 int flags, int *addr_len) 1726 { 1727 struct inet_sock *inet = inet_sk(sk); 1728 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 1729 struct sk_buff *skb; 1730 unsigned int ulen, copied; 1731 int off, err, peeking = flags & MSG_PEEK; 1732 int is_udplite = IS_UDPLITE(sk); 1733 bool checksum_valid = false; 1734 1735 if (flags & MSG_ERRQUEUE) 1736 return ip_recv_error(sk, msg, len, addr_len); 1737 1738 try_again: 1739 off = sk_peek_offset(sk, flags); 1740 skb = __skb_recv_udp(sk, flags, noblock, &off, &err); 1741 if (!skb) 1742 return err; 1743 1744 ulen = udp_skb_len(skb); 1745 copied = len; 1746 if (copied > ulen - off) 1747 copied = ulen - off; 1748 else if (copied < ulen) 1749 msg->msg_flags |= MSG_TRUNC; 1750 1751 /* 1752 * If checksum is needed at all, try to do it while copying the 1753 * data. If the data is truncated, or if we only want a partial 1754 * coverage checksum (UDP-Lite), do it before the copy. 1755 */ 1756 1757 if (copied < ulen || peeking || 1758 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { 1759 checksum_valid = udp_skb_csum_unnecessary(skb) || 1760 !__udp_lib_checksum_complete(skb); 1761 if (!checksum_valid) 1762 goto csum_copy_err; 1763 } 1764 1765 if (checksum_valid || udp_skb_csum_unnecessary(skb)) { 1766 if (udp_skb_is_linear(skb)) 1767 err = copy_linear_skb(skb, copied, off, &msg->msg_iter); 1768 else 1769 err = skb_copy_datagram_msg(skb, off, msg, copied); 1770 } else { 1771 err = skb_copy_and_csum_datagram_msg(skb, off, msg); 1772 1773 if (err == -EINVAL) 1774 goto csum_copy_err; 1775 } 1776 1777 if (unlikely(err)) { 1778 if (!peeking) { 1779 atomic_inc(&sk->sk_drops); 1780 UDP_INC_STATS(sock_net(sk), 1781 UDP_MIB_INERRORS, is_udplite); 1782 } 1783 kfree_skb(skb); 1784 return err; 1785 } 1786 1787 if (!peeking) 1788 UDP_INC_STATS(sock_net(sk), 1789 UDP_MIB_INDATAGRAMS, is_udplite); 1790 1791 sock_recv_ts_and_drops(msg, sk, skb); 1792 1793 /* Copy the address. */ 1794 if (sin) { 1795 sin->sin_family = AF_INET; 1796 sin->sin_port = udp_hdr(skb)->source; 1797 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1798 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1799 *addr_len = sizeof(*sin); 1800 1801 if (cgroup_bpf_enabled) 1802 BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, 1803 (struct sockaddr *)sin); 1804 } 1805 1806 if (udp_sk(sk)->gro_enabled) 1807 udp_cmsg_recv(msg, sk, skb); 1808 1809 if (inet->cmsg_flags) 1810 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off); 1811 1812 err = copied; 1813 if (flags & MSG_TRUNC) 1814 err = ulen; 1815 1816 skb_consume_udp(sk, skb, peeking ? -err : err); 1817 return err; 1818 1819 csum_copy_err: 1820 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, 1821 udp_skb_destructor)) { 1822 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 1823 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1824 } 1825 kfree_skb(skb); 1826 1827 /* starting over for a new packet, but check if we need to yield */ 1828 cond_resched(); 1829 msg->msg_flags &= ~MSG_TRUNC; 1830 goto try_again; 1831 } 1832 1833 int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 1834 { 1835 /* This check is replicated from __ip4_datagram_connect() and 1836 * intended to prevent BPF program called below from accessing bytes 1837 * that are out of the bound specified by user in addr_len. 1838 */ 1839 if (addr_len < sizeof(struct sockaddr_in)) 1840 return -EINVAL; 1841 1842 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr); 1843 } 1844 EXPORT_SYMBOL(udp_pre_connect); 1845 1846 int __udp_disconnect(struct sock *sk, int flags) 1847 { 1848 struct inet_sock *inet = inet_sk(sk); 1849 /* 1850 * 1003.1g - break association. 1851 */ 1852 1853 sk->sk_state = TCP_CLOSE; 1854 inet->inet_daddr = 0; 1855 inet->inet_dport = 0; 1856 sock_rps_reset_rxhash(sk); 1857 sk->sk_bound_dev_if = 0; 1858 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1859 inet_reset_saddr(sk); 1860 1861 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1862 sk->sk_prot->unhash(sk); 1863 inet->inet_sport = 0; 1864 } 1865 sk_dst_reset(sk); 1866 return 0; 1867 } 1868 EXPORT_SYMBOL(__udp_disconnect); 1869 1870 int udp_disconnect(struct sock *sk, int flags) 1871 { 1872 lock_sock(sk); 1873 __udp_disconnect(sk, flags); 1874 release_sock(sk); 1875 return 0; 1876 } 1877 EXPORT_SYMBOL(udp_disconnect); 1878 1879 void udp_lib_unhash(struct sock *sk) 1880 { 1881 if (sk_hashed(sk)) { 1882 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1883 struct udp_hslot *hslot, *hslot2; 1884 1885 hslot = udp_hashslot(udptable, sock_net(sk), 1886 udp_sk(sk)->udp_port_hash); 1887 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1888 1889 spin_lock_bh(&hslot->lock); 1890 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1891 reuseport_detach_sock(sk); 1892 if (sk_del_node_init_rcu(sk)) { 1893 hslot->count--; 1894 inet_sk(sk)->inet_num = 0; 1895 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1896 1897 spin_lock(&hslot2->lock); 1898 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1899 hslot2->count--; 1900 spin_unlock(&hslot2->lock); 1901 } 1902 spin_unlock_bh(&hslot->lock); 1903 } 1904 } 1905 EXPORT_SYMBOL(udp_lib_unhash); 1906 1907 /* 1908 * inet_rcv_saddr was changed, we must rehash secondary hash 1909 */ 1910 void udp_lib_rehash(struct sock *sk, u16 newhash) 1911 { 1912 if (sk_hashed(sk)) { 1913 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1914 struct udp_hslot *hslot, *hslot2, *nhslot2; 1915 1916 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1917 nhslot2 = udp_hashslot2(udptable, newhash); 1918 udp_sk(sk)->udp_portaddr_hash = newhash; 1919 1920 if (hslot2 != nhslot2 || 1921 rcu_access_pointer(sk->sk_reuseport_cb)) { 1922 hslot = udp_hashslot(udptable, sock_net(sk), 1923 udp_sk(sk)->udp_port_hash); 1924 /* we must lock primary chain too */ 1925 spin_lock_bh(&hslot->lock); 1926 if (rcu_access_pointer(sk->sk_reuseport_cb)) 1927 reuseport_detach_sock(sk); 1928 1929 if (hslot2 != nhslot2) { 1930 spin_lock(&hslot2->lock); 1931 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1932 hslot2->count--; 1933 spin_unlock(&hslot2->lock); 1934 1935 spin_lock(&nhslot2->lock); 1936 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1937 &nhslot2->head); 1938 nhslot2->count++; 1939 spin_unlock(&nhslot2->lock); 1940 } 1941 1942 spin_unlock_bh(&hslot->lock); 1943 } 1944 } 1945 } 1946 EXPORT_SYMBOL(udp_lib_rehash); 1947 1948 void udp_v4_rehash(struct sock *sk) 1949 { 1950 u16 new_hash = ipv4_portaddr_hash(sock_net(sk), 1951 inet_sk(sk)->inet_rcv_saddr, 1952 inet_sk(sk)->inet_num); 1953 udp_lib_rehash(sk, new_hash); 1954 } 1955 1956 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1957 { 1958 int rc; 1959 1960 if (inet_sk(sk)->inet_daddr) { 1961 sock_rps_save_rxhash(sk, skb); 1962 sk_mark_napi_id(sk, skb); 1963 sk_incoming_cpu_update(sk); 1964 } else { 1965 sk_mark_napi_id_once(sk, skb); 1966 } 1967 1968 rc = __udp_enqueue_schedule_skb(sk, skb); 1969 if (rc < 0) { 1970 int is_udplite = IS_UDPLITE(sk); 1971 1972 /* Note that an ENOMEM error is charged twice */ 1973 if (rc == -ENOMEM) 1974 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1975 is_udplite); 1976 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1977 kfree_skb(skb); 1978 trace_udp_fail_queue_rcv_skb(rc, sk); 1979 return -1; 1980 } 1981 1982 return 0; 1983 } 1984 1985 /* returns: 1986 * -1: error 1987 * 0: success 1988 * >0: "udp encap" protocol resubmission 1989 * 1990 * Note that in the success and error cases, the skb is assumed to 1991 * have either been requeued or freed. 1992 */ 1993 static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb) 1994 { 1995 struct udp_sock *up = udp_sk(sk); 1996 int is_udplite = IS_UDPLITE(sk); 1997 1998 /* 1999 * Charge it to the socket, dropping if the queue is full. 2000 */ 2001 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 2002 goto drop; 2003 nf_reset_ct(skb); 2004 2005 if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) { 2006 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 2007 2008 /* 2009 * This is an encapsulation socket so pass the skb to 2010 * the socket's udp_encap_rcv() hook. Otherwise, just 2011 * fall through and pass this up the UDP socket. 2012 * up->encap_rcv() returns the following value: 2013 * =0 if skb was successfully passed to the encap 2014 * handler or was discarded by it. 2015 * >0 if skb should be passed on to UDP. 2016 * <0 if skb should be resubmitted as proto -N 2017 */ 2018 2019 /* if we're overly short, let UDP handle it */ 2020 encap_rcv = READ_ONCE(up->encap_rcv); 2021 if (encap_rcv) { 2022 int ret; 2023 2024 /* Verify checksum before giving to encap */ 2025 if (udp_lib_checksum_complete(skb)) 2026 goto csum_error; 2027 2028 ret = encap_rcv(sk, skb); 2029 if (ret <= 0) { 2030 __UDP_INC_STATS(sock_net(sk), 2031 UDP_MIB_INDATAGRAMS, 2032 is_udplite); 2033 return -ret; 2034 } 2035 } 2036 2037 /* FALLTHROUGH -- it's a UDP Packet */ 2038 } 2039 2040 /* 2041 * UDP-Lite specific tests, ignored on UDP sockets 2042 */ 2043 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 2044 2045 /* 2046 * MIB statistics other than incrementing the error count are 2047 * disabled for the following two types of errors: these depend 2048 * on the application settings, not on the functioning of the 2049 * protocol stack as such. 2050 * 2051 * RFC 3828 here recommends (sec 3.3): "There should also be a 2052 * way ... to ... at least let the receiving application block 2053 * delivery of packets with coverage values less than a value 2054 * provided by the application." 2055 */ 2056 if (up->pcrlen == 0) { /* full coverage was set */ 2057 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n", 2058 UDP_SKB_CB(skb)->cscov, skb->len); 2059 goto drop; 2060 } 2061 /* The next case involves violating the min. coverage requested 2062 * by the receiver. This is subtle: if receiver wants x and x is 2063 * greater than the buffersize/MTU then receiver will complain 2064 * that it wants x while sender emits packets of smaller size y. 2065 * Therefore the above ...()->partial_cov statement is essential. 2066 */ 2067 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 2068 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n", 2069 UDP_SKB_CB(skb)->cscov, up->pcrlen); 2070 goto drop; 2071 } 2072 } 2073 2074 prefetch(&sk->sk_rmem_alloc); 2075 if (rcu_access_pointer(sk->sk_filter) && 2076 udp_lib_checksum_complete(skb)) 2077 goto csum_error; 2078 2079 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 2080 goto drop; 2081 2082 udp_csum_pull_header(skb); 2083 2084 ipv4_pktinfo_prepare(sk, skb); 2085 return __udp_queue_rcv_skb(sk, skb); 2086 2087 csum_error: 2088 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 2089 drop: 2090 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 2091 atomic_inc(&sk->sk_drops); 2092 kfree_skb(skb); 2093 return -1; 2094 } 2095 2096 static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 2097 { 2098 struct sk_buff *next, *segs; 2099 int ret; 2100 2101 if (likely(!udp_unexpected_gso(sk, skb))) 2102 return udp_queue_rcv_one_skb(sk, skb); 2103 2104 BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_SGO_CB_OFFSET); 2105 __skb_push(skb, -skb_mac_offset(skb)); 2106 segs = udp_rcv_segment(sk, skb, true); 2107 for (skb = segs; skb; skb = next) { 2108 next = skb->next; 2109 __skb_pull(skb, skb_transport_offset(skb)); 2110 ret = udp_queue_rcv_one_skb(sk, skb); 2111 if (ret > 0) 2112 ip_protocol_deliver_rcu(dev_net(skb->dev), skb, -ret); 2113 } 2114 return 0; 2115 } 2116 2117 /* For TCP sockets, sk_rx_dst is protected by socket lock 2118 * For UDP, we use xchg() to guard against concurrent changes. 2119 */ 2120 bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 2121 { 2122 struct dst_entry *old; 2123 2124 if (dst_hold_safe(dst)) { 2125 old = xchg(&sk->sk_rx_dst, dst); 2126 dst_release(old); 2127 return old != dst; 2128 } 2129 return false; 2130 } 2131 EXPORT_SYMBOL(udp_sk_rx_dst_set); 2132 2133 /* 2134 * Multicasts and broadcasts go to each listener. 2135 * 2136 * Note: called only from the BH handler context. 2137 */ 2138 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 2139 struct udphdr *uh, 2140 __be32 saddr, __be32 daddr, 2141 struct udp_table *udptable, 2142 int proto) 2143 { 2144 struct sock *sk, *first = NULL; 2145 unsigned short hnum = ntohs(uh->dest); 2146 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 2147 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 2148 unsigned int offset = offsetof(typeof(*sk), sk_node); 2149 int dif = skb->dev->ifindex; 2150 int sdif = inet_sdif(skb); 2151 struct hlist_node *node; 2152 struct sk_buff *nskb; 2153 2154 if (use_hash2) { 2155 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & 2156 udptable->mask; 2157 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask; 2158 start_lookup: 2159 hslot = &udptable->hash2[hash2]; 2160 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 2161 } 2162 2163 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 2164 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr, 2165 uh->source, saddr, dif, sdif, hnum)) 2166 continue; 2167 2168 if (!first) { 2169 first = sk; 2170 continue; 2171 } 2172 nskb = skb_clone(skb, GFP_ATOMIC); 2173 2174 if (unlikely(!nskb)) { 2175 atomic_inc(&sk->sk_drops); 2176 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 2177 IS_UDPLITE(sk)); 2178 __UDP_INC_STATS(net, UDP_MIB_INERRORS, 2179 IS_UDPLITE(sk)); 2180 continue; 2181 } 2182 if (udp_queue_rcv_skb(sk, nskb) > 0) 2183 consume_skb(nskb); 2184 } 2185 2186 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 2187 if (use_hash2 && hash2 != hash2_any) { 2188 hash2 = hash2_any; 2189 goto start_lookup; 2190 } 2191 2192 if (first) { 2193 if (udp_queue_rcv_skb(first, skb) > 0) 2194 consume_skb(skb); 2195 } else { 2196 kfree_skb(skb); 2197 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 2198 proto == IPPROTO_UDPLITE); 2199 } 2200 return 0; 2201 } 2202 2203 /* Initialize UDP checksum. If exited with zero value (success), 2204 * CHECKSUM_UNNECESSARY means, that no more checks are required. 2205 * Otherwise, csum completion requires checksumming packet body, 2206 * including udp header and folding it to skb->csum. 2207 */ 2208 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 2209 int proto) 2210 { 2211 int err; 2212 2213 UDP_SKB_CB(skb)->partial_cov = 0; 2214 UDP_SKB_CB(skb)->cscov = skb->len; 2215 2216 if (proto == IPPROTO_UDPLITE) { 2217 err = udplite_checksum_init(skb, uh); 2218 if (err) 2219 return err; 2220 2221 if (UDP_SKB_CB(skb)->partial_cov) { 2222 skb->csum = inet_compute_pseudo(skb, proto); 2223 return 0; 2224 } 2225 } 2226 2227 /* Note, we are only interested in != 0 or == 0, thus the 2228 * force to int. 2229 */ 2230 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check, 2231 inet_compute_pseudo); 2232 if (err) 2233 return err; 2234 2235 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) { 2236 /* If SW calculated the value, we know it's bad */ 2237 if (skb->csum_complete_sw) 2238 return 1; 2239 2240 /* HW says the value is bad. Let's validate that. 2241 * skb->csum is no longer the full packet checksum, 2242 * so don't treat it as such. 2243 */ 2244 skb_checksum_complete_unset(skb); 2245 } 2246 2247 return 0; 2248 } 2249 2250 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and 2251 * return code conversion for ip layer consumption 2252 */ 2253 static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb, 2254 struct udphdr *uh) 2255 { 2256 int ret; 2257 2258 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 2259 skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo); 2260 2261 ret = udp_queue_rcv_skb(sk, skb); 2262 2263 /* a return value > 0 means to resubmit the input, but 2264 * it wants the return to be -protocol, or 0 2265 */ 2266 if (ret > 0) 2267 return -ret; 2268 return 0; 2269 } 2270 2271 /* 2272 * All we need to do is get the socket, and then do a checksum. 2273 */ 2274 2275 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 2276 int proto) 2277 { 2278 struct sock *sk; 2279 struct udphdr *uh; 2280 unsigned short ulen; 2281 struct rtable *rt = skb_rtable(skb); 2282 __be32 saddr, daddr; 2283 struct net *net = dev_net(skb->dev); 2284 2285 /* 2286 * Validate the packet. 2287 */ 2288 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 2289 goto drop; /* No space for header. */ 2290 2291 uh = udp_hdr(skb); 2292 ulen = ntohs(uh->len); 2293 saddr = ip_hdr(skb)->saddr; 2294 daddr = ip_hdr(skb)->daddr; 2295 2296 if (ulen > skb->len) 2297 goto short_packet; 2298 2299 if (proto == IPPROTO_UDP) { 2300 /* UDP validates ulen. */ 2301 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 2302 goto short_packet; 2303 uh = udp_hdr(skb); 2304 } 2305 2306 if (udp4_csum_init(skb, uh, proto)) 2307 goto csum_error; 2308 2309 sk = skb_steal_sock(skb); 2310 if (sk) { 2311 struct dst_entry *dst = skb_dst(skb); 2312 int ret; 2313 2314 if (unlikely(sk->sk_rx_dst != dst)) 2315 udp_sk_rx_dst_set(sk, dst); 2316 2317 ret = udp_unicast_rcv_skb(sk, skb, uh); 2318 sock_put(sk); 2319 return ret; 2320 } 2321 2322 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 2323 return __udp4_lib_mcast_deliver(net, skb, uh, 2324 saddr, daddr, udptable, proto); 2325 2326 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 2327 if (sk) 2328 return udp_unicast_rcv_skb(sk, skb, uh); 2329 2330 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 2331 goto drop; 2332 nf_reset_ct(skb); 2333 2334 /* No socket. Drop packet silently, if checksum is wrong */ 2335 if (udp_lib_checksum_complete(skb)) 2336 goto csum_error; 2337 2338 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 2339 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 2340 2341 /* 2342 * Hmm. We got an UDP packet to a port to which we 2343 * don't wanna listen. Ignore it. 2344 */ 2345 kfree_skb(skb); 2346 return 0; 2347 2348 short_packet: 2349 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 2350 proto == IPPROTO_UDPLITE ? "Lite" : "", 2351 &saddr, ntohs(uh->source), 2352 ulen, skb->len, 2353 &daddr, ntohs(uh->dest)); 2354 goto drop; 2355 2356 csum_error: 2357 /* 2358 * RFC1122: OK. Discards the bad packet silently (as far as 2359 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 2360 */ 2361 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 2362 proto == IPPROTO_UDPLITE ? "Lite" : "", 2363 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 2364 ulen); 2365 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 2366 drop: 2367 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 2368 kfree_skb(skb); 2369 return 0; 2370 } 2371 2372 /* We can only early demux multicast if there is a single matching socket. 2373 * If more than one socket found returns NULL 2374 */ 2375 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net, 2376 __be16 loc_port, __be32 loc_addr, 2377 __be16 rmt_port, __be32 rmt_addr, 2378 int dif, int sdif) 2379 { 2380 struct sock *sk, *result; 2381 unsigned short hnum = ntohs(loc_port); 2382 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask); 2383 struct udp_hslot *hslot = &udp_table.hash[slot]; 2384 2385 /* Do not bother scanning a too big list */ 2386 if (hslot->count > 10) 2387 return NULL; 2388 2389 result = NULL; 2390 sk_for_each_rcu(sk, &hslot->head) { 2391 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr, 2392 rmt_port, rmt_addr, dif, sdif, hnum)) { 2393 if (result) 2394 return NULL; 2395 result = sk; 2396 } 2397 } 2398 2399 return result; 2400 } 2401 2402 /* For unicast we should only early demux connected sockets or we can 2403 * break forwarding setups. The chains here can be long so only check 2404 * if the first socket is an exact match and if not move on. 2405 */ 2406 static struct sock *__udp4_lib_demux_lookup(struct net *net, 2407 __be16 loc_port, __be32 loc_addr, 2408 __be16 rmt_port, __be32 rmt_addr, 2409 int dif, int sdif) 2410 { 2411 unsigned short hnum = ntohs(loc_port); 2412 unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum); 2413 unsigned int slot2 = hash2 & udp_table.mask; 2414 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 2415 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); 2416 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 2417 struct sock *sk; 2418 2419 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 2420 if (INET_MATCH(sk, net, acookie, rmt_addr, 2421 loc_addr, ports, dif, sdif)) 2422 return sk; 2423 /* Only check first socket in chain */ 2424 break; 2425 } 2426 return NULL; 2427 } 2428 2429 int udp_v4_early_demux(struct sk_buff *skb) 2430 { 2431 struct net *net = dev_net(skb->dev); 2432 struct in_device *in_dev = NULL; 2433 const struct iphdr *iph; 2434 const struct udphdr *uh; 2435 struct sock *sk = NULL; 2436 struct dst_entry *dst; 2437 int dif = skb->dev->ifindex; 2438 int sdif = inet_sdif(skb); 2439 int ours; 2440 2441 /* validate the packet */ 2442 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) 2443 return 0; 2444 2445 iph = ip_hdr(skb); 2446 uh = udp_hdr(skb); 2447 2448 if (skb->pkt_type == PACKET_MULTICAST) { 2449 in_dev = __in_dev_get_rcu(skb->dev); 2450 2451 if (!in_dev) 2452 return 0; 2453 2454 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, 2455 iph->protocol); 2456 if (!ours) 2457 return 0; 2458 2459 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, 2460 uh->source, iph->saddr, 2461 dif, sdif); 2462 } else if (skb->pkt_type == PACKET_HOST) { 2463 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, 2464 uh->source, iph->saddr, dif, sdif); 2465 } 2466 2467 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 2468 return 0; 2469 2470 skb->sk = sk; 2471 skb->destructor = sock_efree; 2472 dst = READ_ONCE(sk->sk_rx_dst); 2473 2474 if (dst) 2475 dst = dst_check(dst, 0); 2476 if (dst) { 2477 u32 itag = 0; 2478 2479 /* set noref for now. 2480 * any place which wants to hold dst has to call 2481 * dst_hold_safe() 2482 */ 2483 skb_dst_set_noref(skb, dst); 2484 2485 /* for unconnected multicast sockets we need to validate 2486 * the source on each packet 2487 */ 2488 if (!inet_sk(sk)->inet_daddr && in_dev) 2489 return ip_mc_validate_source(skb, iph->daddr, 2490 iph->saddr, iph->tos, 2491 skb->dev, in_dev, &itag); 2492 } 2493 return 0; 2494 } 2495 2496 int udp_rcv(struct sk_buff *skb) 2497 { 2498 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 2499 } 2500 2501 void udp_destroy_sock(struct sock *sk) 2502 { 2503 struct udp_sock *up = udp_sk(sk); 2504 bool slow = lock_sock_fast(sk); 2505 udp_flush_pending_frames(sk); 2506 unlock_sock_fast(sk, slow); 2507 if (static_branch_unlikely(&udp_encap_needed_key)) { 2508 if (up->encap_type) { 2509 void (*encap_destroy)(struct sock *sk); 2510 encap_destroy = READ_ONCE(up->encap_destroy); 2511 if (encap_destroy) 2512 encap_destroy(sk); 2513 } 2514 if (up->encap_enabled) 2515 static_branch_dec(&udp_encap_needed_key); 2516 } 2517 } 2518 2519 /* 2520 * Socket option code for UDP 2521 */ 2522 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 2523 char __user *optval, unsigned int optlen, 2524 int (*push_pending_frames)(struct sock *)) 2525 { 2526 struct udp_sock *up = udp_sk(sk); 2527 int val, valbool; 2528 int err = 0; 2529 int is_udplite = IS_UDPLITE(sk); 2530 2531 if (optlen < sizeof(int)) 2532 return -EINVAL; 2533 2534 if (get_user(val, (int __user *)optval)) 2535 return -EFAULT; 2536 2537 valbool = val ? 1 : 0; 2538 2539 switch (optname) { 2540 case UDP_CORK: 2541 if (val != 0) { 2542 up->corkflag = 1; 2543 } else { 2544 up->corkflag = 0; 2545 lock_sock(sk); 2546 push_pending_frames(sk); 2547 release_sock(sk); 2548 } 2549 break; 2550 2551 case UDP_ENCAP: 2552 switch (val) { 2553 case 0: 2554 #ifdef CONFIG_XFRM 2555 case UDP_ENCAP_ESPINUDP: 2556 case UDP_ENCAP_ESPINUDP_NON_IKE: 2557 up->encap_rcv = xfrm4_udp_encap_rcv; 2558 #endif 2559 /* FALLTHROUGH */ 2560 case UDP_ENCAP_L2TPINUDP: 2561 up->encap_type = val; 2562 lock_sock(sk); 2563 udp_tunnel_encap_enable(sk->sk_socket); 2564 release_sock(sk); 2565 break; 2566 default: 2567 err = -ENOPROTOOPT; 2568 break; 2569 } 2570 break; 2571 2572 case UDP_NO_CHECK6_TX: 2573 up->no_check6_tx = valbool; 2574 break; 2575 2576 case UDP_NO_CHECK6_RX: 2577 up->no_check6_rx = valbool; 2578 break; 2579 2580 case UDP_SEGMENT: 2581 if (val < 0 || val > USHRT_MAX) 2582 return -EINVAL; 2583 up->gso_size = val; 2584 break; 2585 2586 case UDP_GRO: 2587 lock_sock(sk); 2588 if (valbool) 2589 udp_tunnel_encap_enable(sk->sk_socket); 2590 up->gro_enabled = valbool; 2591 release_sock(sk); 2592 break; 2593 2594 /* 2595 * UDP-Lite's partial checksum coverage (RFC 3828). 2596 */ 2597 /* The sender sets actual checksum coverage length via this option. 2598 * The case coverage > packet length is handled by send module. */ 2599 case UDPLITE_SEND_CSCOV: 2600 if (!is_udplite) /* Disable the option on UDP sockets */ 2601 return -ENOPROTOOPT; 2602 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 2603 val = 8; 2604 else if (val > USHRT_MAX) 2605 val = USHRT_MAX; 2606 up->pcslen = val; 2607 up->pcflag |= UDPLITE_SEND_CC; 2608 break; 2609 2610 /* The receiver specifies a minimum checksum coverage value. To make 2611 * sense, this should be set to at least 8 (as done below). If zero is 2612 * used, this again means full checksum coverage. */ 2613 case UDPLITE_RECV_CSCOV: 2614 if (!is_udplite) /* Disable the option on UDP sockets */ 2615 return -ENOPROTOOPT; 2616 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 2617 val = 8; 2618 else if (val > USHRT_MAX) 2619 val = USHRT_MAX; 2620 up->pcrlen = val; 2621 up->pcflag |= UDPLITE_RECV_CC; 2622 break; 2623 2624 default: 2625 err = -ENOPROTOOPT; 2626 break; 2627 } 2628 2629 return err; 2630 } 2631 EXPORT_SYMBOL(udp_lib_setsockopt); 2632 2633 int udp_setsockopt(struct sock *sk, int level, int optname, 2634 char __user *optval, unsigned int optlen) 2635 { 2636 if (level == SOL_UDP || level == SOL_UDPLITE) 2637 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2638 udp_push_pending_frames); 2639 return ip_setsockopt(sk, level, optname, optval, optlen); 2640 } 2641 2642 #ifdef CONFIG_COMPAT 2643 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 2644 char __user *optval, unsigned int optlen) 2645 { 2646 if (level == SOL_UDP || level == SOL_UDPLITE) 2647 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 2648 udp_push_pending_frames); 2649 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 2650 } 2651 #endif 2652 2653 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 2654 char __user *optval, int __user *optlen) 2655 { 2656 struct udp_sock *up = udp_sk(sk); 2657 int val, len; 2658 2659 if (get_user(len, optlen)) 2660 return -EFAULT; 2661 2662 len = min_t(unsigned int, len, sizeof(int)); 2663 2664 if (len < 0) 2665 return -EINVAL; 2666 2667 switch (optname) { 2668 case UDP_CORK: 2669 val = up->corkflag; 2670 break; 2671 2672 case UDP_ENCAP: 2673 val = up->encap_type; 2674 break; 2675 2676 case UDP_NO_CHECK6_TX: 2677 val = up->no_check6_tx; 2678 break; 2679 2680 case UDP_NO_CHECK6_RX: 2681 val = up->no_check6_rx; 2682 break; 2683 2684 case UDP_SEGMENT: 2685 val = up->gso_size; 2686 break; 2687 2688 /* The following two cannot be changed on UDP sockets, the return is 2689 * always 0 (which corresponds to the full checksum coverage of UDP). */ 2690 case UDPLITE_SEND_CSCOV: 2691 val = up->pcslen; 2692 break; 2693 2694 case UDPLITE_RECV_CSCOV: 2695 val = up->pcrlen; 2696 break; 2697 2698 default: 2699 return -ENOPROTOOPT; 2700 } 2701 2702 if (put_user(len, optlen)) 2703 return -EFAULT; 2704 if (copy_to_user(optval, &val, len)) 2705 return -EFAULT; 2706 return 0; 2707 } 2708 EXPORT_SYMBOL(udp_lib_getsockopt); 2709 2710 int udp_getsockopt(struct sock *sk, int level, int optname, 2711 char __user *optval, int __user *optlen) 2712 { 2713 if (level == SOL_UDP || level == SOL_UDPLITE) 2714 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2715 return ip_getsockopt(sk, level, optname, optval, optlen); 2716 } 2717 2718 #ifdef CONFIG_COMPAT 2719 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 2720 char __user *optval, int __user *optlen) 2721 { 2722 if (level == SOL_UDP || level == SOL_UDPLITE) 2723 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 2724 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 2725 } 2726 #endif 2727 /** 2728 * udp_poll - wait for a UDP event. 2729 * @file - file struct 2730 * @sock - socket 2731 * @wait - poll table 2732 * 2733 * This is same as datagram poll, except for the special case of 2734 * blocking sockets. If application is using a blocking fd 2735 * and a packet with checksum error is in the queue; 2736 * then it could get return from select indicating data available 2737 * but then block when reading it. Add special case code 2738 * to work around these arguably broken applications. 2739 */ 2740 __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait) 2741 { 2742 __poll_t mask = datagram_poll(file, sock, wait); 2743 struct sock *sk = sock->sk; 2744 2745 if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue)) 2746 mask |= EPOLLIN | EPOLLRDNORM; 2747 2748 /* Check for false positives due to checksum errors */ 2749 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 2750 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1) 2751 mask &= ~(EPOLLIN | EPOLLRDNORM); 2752 2753 return mask; 2754 2755 } 2756 EXPORT_SYMBOL(udp_poll); 2757 2758 int udp_abort(struct sock *sk, int err) 2759 { 2760 lock_sock(sk); 2761 2762 sk->sk_err = err; 2763 sk->sk_error_report(sk); 2764 __udp_disconnect(sk, 0); 2765 2766 release_sock(sk); 2767 2768 return 0; 2769 } 2770 EXPORT_SYMBOL_GPL(udp_abort); 2771 2772 struct proto udp_prot = { 2773 .name = "UDP", 2774 .owner = THIS_MODULE, 2775 .close = udp_lib_close, 2776 .pre_connect = udp_pre_connect, 2777 .connect = ip4_datagram_connect, 2778 .disconnect = udp_disconnect, 2779 .ioctl = udp_ioctl, 2780 .init = udp_init_sock, 2781 .destroy = udp_destroy_sock, 2782 .setsockopt = udp_setsockopt, 2783 .getsockopt = udp_getsockopt, 2784 .sendmsg = udp_sendmsg, 2785 .recvmsg = udp_recvmsg, 2786 .sendpage = udp_sendpage, 2787 .release_cb = ip4_datagram_release_cb, 2788 .hash = udp_lib_hash, 2789 .unhash = udp_lib_unhash, 2790 .rehash = udp_v4_rehash, 2791 .get_port = udp_v4_get_port, 2792 .memory_allocated = &udp_memory_allocated, 2793 .sysctl_mem = sysctl_udp_mem, 2794 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), 2795 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), 2796 .obj_size = sizeof(struct udp_sock), 2797 .h.udp_table = &udp_table, 2798 #ifdef CONFIG_COMPAT 2799 .compat_setsockopt = compat_udp_setsockopt, 2800 .compat_getsockopt = compat_udp_getsockopt, 2801 #endif 2802 .diag_destroy = udp_abort, 2803 }; 2804 EXPORT_SYMBOL(udp_prot); 2805 2806 /* ------------------------------------------------------------------------ */ 2807 #ifdef CONFIG_PROC_FS 2808 2809 static struct sock *udp_get_first(struct seq_file *seq, int start) 2810 { 2811 struct sock *sk; 2812 struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file)); 2813 struct udp_iter_state *state = seq->private; 2814 struct net *net = seq_file_net(seq); 2815 2816 for (state->bucket = start; state->bucket <= afinfo->udp_table->mask; 2817 ++state->bucket) { 2818 struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket]; 2819 2820 if (hlist_empty(&hslot->head)) 2821 continue; 2822 2823 spin_lock_bh(&hslot->lock); 2824 sk_for_each(sk, &hslot->head) { 2825 if (!net_eq(sock_net(sk), net)) 2826 continue; 2827 if (sk->sk_family == afinfo->family) 2828 goto found; 2829 } 2830 spin_unlock_bh(&hslot->lock); 2831 } 2832 sk = NULL; 2833 found: 2834 return sk; 2835 } 2836 2837 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2838 { 2839 struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file)); 2840 struct udp_iter_state *state = seq->private; 2841 struct net *net = seq_file_net(seq); 2842 2843 do { 2844 sk = sk_next(sk); 2845 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != afinfo->family)); 2846 2847 if (!sk) { 2848 if (state->bucket <= afinfo->udp_table->mask) 2849 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); 2850 return udp_get_first(seq, state->bucket + 1); 2851 } 2852 return sk; 2853 } 2854 2855 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2856 { 2857 struct sock *sk = udp_get_first(seq, 0); 2858 2859 if (sk) 2860 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2861 --pos; 2862 return pos ? NULL : sk; 2863 } 2864 2865 void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2866 { 2867 struct udp_iter_state *state = seq->private; 2868 state->bucket = MAX_UDP_PORTS; 2869 2870 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2871 } 2872 EXPORT_SYMBOL(udp_seq_start); 2873 2874 void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2875 { 2876 struct sock *sk; 2877 2878 if (v == SEQ_START_TOKEN) 2879 sk = udp_get_idx(seq, 0); 2880 else 2881 sk = udp_get_next(seq, v); 2882 2883 ++*pos; 2884 return sk; 2885 } 2886 EXPORT_SYMBOL(udp_seq_next); 2887 2888 void udp_seq_stop(struct seq_file *seq, void *v) 2889 { 2890 struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file)); 2891 struct udp_iter_state *state = seq->private; 2892 2893 if (state->bucket <= afinfo->udp_table->mask) 2894 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock); 2895 } 2896 EXPORT_SYMBOL(udp_seq_stop); 2897 2898 /* ------------------------------------------------------------------------ */ 2899 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2900 int bucket) 2901 { 2902 struct inet_sock *inet = inet_sk(sp); 2903 __be32 dest = inet->inet_daddr; 2904 __be32 src = inet->inet_rcv_saddr; 2905 __u16 destp = ntohs(inet->inet_dport); 2906 __u16 srcp = ntohs(inet->inet_sport); 2907 2908 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2909 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 2910 bucket, src, srcp, dest, destp, sp->sk_state, 2911 sk_wmem_alloc_get(sp), 2912 udp_rqueue_get(sp), 2913 0, 0L, 0, 2914 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2915 0, sock_i_ino(sp), 2916 refcount_read(&sp->sk_refcnt), sp, 2917 atomic_read(&sp->sk_drops)); 2918 } 2919 2920 int udp4_seq_show(struct seq_file *seq, void *v) 2921 { 2922 seq_setwidth(seq, 127); 2923 if (v == SEQ_START_TOKEN) 2924 seq_puts(seq, " sl local_address rem_address st tx_queue " 2925 "rx_queue tr tm->when retrnsmt uid timeout " 2926 "inode ref pointer drops"); 2927 else { 2928 struct udp_iter_state *state = seq->private; 2929 2930 udp4_format_sock(v, seq, state->bucket); 2931 } 2932 seq_pad(seq, '\n'); 2933 return 0; 2934 } 2935 2936 const struct seq_operations udp_seq_ops = { 2937 .start = udp_seq_start, 2938 .next = udp_seq_next, 2939 .stop = udp_seq_stop, 2940 .show = udp4_seq_show, 2941 }; 2942 EXPORT_SYMBOL(udp_seq_ops); 2943 2944 static struct udp_seq_afinfo udp4_seq_afinfo = { 2945 .family = AF_INET, 2946 .udp_table = &udp_table, 2947 }; 2948 2949 static int __net_init udp4_proc_init_net(struct net *net) 2950 { 2951 if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops, 2952 sizeof(struct udp_iter_state), &udp4_seq_afinfo)) 2953 return -ENOMEM; 2954 return 0; 2955 } 2956 2957 static void __net_exit udp4_proc_exit_net(struct net *net) 2958 { 2959 remove_proc_entry("udp", net->proc_net); 2960 } 2961 2962 static struct pernet_operations udp4_net_ops = { 2963 .init = udp4_proc_init_net, 2964 .exit = udp4_proc_exit_net, 2965 }; 2966 2967 int __init udp4_proc_init(void) 2968 { 2969 return register_pernet_subsys(&udp4_net_ops); 2970 } 2971 2972 void udp4_proc_exit(void) 2973 { 2974 unregister_pernet_subsys(&udp4_net_ops); 2975 } 2976 #endif /* CONFIG_PROC_FS */ 2977 2978 static __initdata unsigned long uhash_entries; 2979 static int __init set_uhash_entries(char *str) 2980 { 2981 ssize_t ret; 2982 2983 if (!str) 2984 return 0; 2985 2986 ret = kstrtoul(str, 0, &uhash_entries); 2987 if (ret) 2988 return 0; 2989 2990 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2991 uhash_entries = UDP_HTABLE_SIZE_MIN; 2992 return 1; 2993 } 2994 __setup("uhash_entries=", set_uhash_entries); 2995 2996 void __init udp_table_init(struct udp_table *table, const char *name) 2997 { 2998 unsigned int i; 2999 3000 table->hash = alloc_large_system_hash(name, 3001 2 * sizeof(struct udp_hslot), 3002 uhash_entries, 3003 21, /* one slot per 2 MB */ 3004 0, 3005 &table->log, 3006 &table->mask, 3007 UDP_HTABLE_SIZE_MIN, 3008 64 * 1024); 3009 3010 table->hash2 = table->hash + (table->mask + 1); 3011 for (i = 0; i <= table->mask; i++) { 3012 INIT_HLIST_HEAD(&table->hash[i].head); 3013 table->hash[i].count = 0; 3014 spin_lock_init(&table->hash[i].lock); 3015 } 3016 for (i = 0; i <= table->mask; i++) { 3017 INIT_HLIST_HEAD(&table->hash2[i].head); 3018 table->hash2[i].count = 0; 3019 spin_lock_init(&table->hash2[i].lock); 3020 } 3021 } 3022 3023 u32 udp_flow_hashrnd(void) 3024 { 3025 static u32 hashrnd __read_mostly; 3026 3027 net_get_random_once(&hashrnd, sizeof(hashrnd)); 3028 3029 return hashrnd; 3030 } 3031 EXPORT_SYMBOL(udp_flow_hashrnd); 3032 3033 static void __udp_sysctl_init(struct net *net) 3034 { 3035 net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM; 3036 net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM; 3037 3038 #ifdef CONFIG_NET_L3_MASTER_DEV 3039 net->ipv4.sysctl_udp_l3mdev_accept = 0; 3040 #endif 3041 } 3042 3043 static int __net_init udp_sysctl_init(struct net *net) 3044 { 3045 __udp_sysctl_init(net); 3046 return 0; 3047 } 3048 3049 static struct pernet_operations __net_initdata udp_sysctl_ops = { 3050 .init = udp_sysctl_init, 3051 }; 3052 3053 void __init udp_init(void) 3054 { 3055 unsigned long limit; 3056 unsigned int i; 3057 3058 udp_table_init(&udp_table, "UDP"); 3059 limit = nr_free_buffer_pages() / 8; 3060 limit = max(limit, 128UL); 3061 sysctl_udp_mem[0] = limit / 4 * 3; 3062 sysctl_udp_mem[1] = limit; 3063 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 3064 3065 __udp_sysctl_init(&init_net); 3066 3067 /* 16 spinlocks per cpu */ 3068 udp_busylocks_log = ilog2(nr_cpu_ids) + 4; 3069 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log, 3070 GFP_KERNEL); 3071 if (!udp_busylocks) 3072 panic("UDP: failed to alloc udp_busylocks\n"); 3073 for (i = 0; i < (1U << udp_busylocks_log); i++) 3074 spin_lock_init(udp_busylocks + i); 3075 3076 if (register_pernet_subsys(&udp_sysctl_ops)) 3077 panic("UDP: failed to init sysctl parameters.\n"); 3078 } 3079