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 <asm/uaccess.h> 83 #include <asm/ioctls.h> 84 #include <linux/bootmem.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/in.h> 94 #include <linux/errno.h> 95 #include <linux/timer.h> 96 #include <linux/mm.h> 97 #include <linux/inet.h> 98 #include <linux/netdevice.h> 99 #include <linux/slab.h> 100 #include <net/tcp_states.h> 101 #include <linux/skbuff.h> 102 #include <linux/proc_fs.h> 103 #include <linux/seq_file.h> 104 #include <net/net_namespace.h> 105 #include <net/icmp.h> 106 #include <net/route.h> 107 #include <net/checksum.h> 108 #include <net/xfrm.h> 109 #include <trace/events/udp.h> 110 #include <linux/static_key.h> 111 #include <trace/events/skb.h> 112 #include "udp_impl.h" 113 114 struct udp_table udp_table __read_mostly; 115 EXPORT_SYMBOL(udp_table); 116 117 long sysctl_udp_mem[3] __read_mostly; 118 EXPORT_SYMBOL(sysctl_udp_mem); 119 120 int sysctl_udp_rmem_min __read_mostly; 121 EXPORT_SYMBOL(sysctl_udp_rmem_min); 122 123 int sysctl_udp_wmem_min __read_mostly; 124 EXPORT_SYMBOL(sysctl_udp_wmem_min); 125 126 atomic_long_t udp_memory_allocated; 127 EXPORT_SYMBOL(udp_memory_allocated); 128 129 #define MAX_UDP_PORTS 65536 130 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 131 132 static int udp_lib_lport_inuse(struct net *net, __u16 num, 133 const struct udp_hslot *hslot, 134 unsigned long *bitmap, 135 struct sock *sk, 136 int (*saddr_comp)(const struct sock *sk1, 137 const struct sock *sk2), 138 unsigned int log) 139 { 140 struct sock *sk2; 141 struct hlist_nulls_node *node; 142 143 sk_nulls_for_each(sk2, node, &hslot->head) 144 if (net_eq(sock_net(sk2), net) && 145 sk2 != sk && 146 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 147 (!sk2->sk_reuse || !sk->sk_reuse) && 148 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 149 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 150 (*saddr_comp)(sk, sk2)) { 151 if (bitmap) 152 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 153 bitmap); 154 else 155 return 1; 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 int (*saddr_comp)(const struct sock *sk1, 168 const struct sock *sk2)) 169 { 170 struct sock *sk2; 171 struct hlist_nulls_node *node; 172 int res = 0; 173 174 spin_lock(&hslot2->lock); 175 udp_portaddr_for_each_entry(sk2, node, &hslot2->head) 176 if (net_eq(sock_net(sk2), net) && 177 sk2 != sk && 178 (udp_sk(sk2)->udp_port_hash == num) && 179 (!sk2->sk_reuse || !sk->sk_reuse) && 180 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 181 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 182 (*saddr_comp)(sk, sk2)) { 183 res = 1; 184 break; 185 } 186 spin_unlock(&hslot2->lock); 187 return res; 188 } 189 190 /** 191 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 192 * 193 * @sk: socket struct in question 194 * @snum: port number to look up 195 * @saddr_comp: AF-dependent comparison of bound local IP addresses 196 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 197 * with NULL address 198 */ 199 int udp_lib_get_port(struct sock *sk, unsigned short snum, 200 int (*saddr_comp)(const struct sock *sk1, 201 const struct sock *sk2), 202 unsigned int hash2_nulladdr) 203 { 204 struct udp_hslot *hslot, *hslot2; 205 struct udp_table *udptable = sk->sk_prot->h.udp_table; 206 int error = 1; 207 struct net *net = sock_net(sk); 208 209 if (!snum) { 210 int low, high, remaining; 211 unsigned int rand; 212 unsigned short first, last; 213 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 214 215 inet_get_local_port_range(&low, &high); 216 remaining = (high - low) + 1; 217 218 rand = net_random(); 219 first = (((u64)rand * remaining) >> 32) + low; 220 /* 221 * force rand to be an odd multiple of UDP_HTABLE_SIZE 222 */ 223 rand = (rand | 1) * (udptable->mask + 1); 224 last = first + udptable->mask + 1; 225 do { 226 hslot = udp_hashslot(udptable, net, first); 227 bitmap_zero(bitmap, PORTS_PER_CHAIN); 228 spin_lock_bh(&hslot->lock); 229 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 230 saddr_comp, udptable->log); 231 232 snum = first; 233 /* 234 * Iterate on all possible values of snum for this hash. 235 * Using steps of an odd multiple of UDP_HTABLE_SIZE 236 * give us randomization and full range coverage. 237 */ 238 do { 239 if (low <= snum && snum <= high && 240 !test_bit(snum >> udptable->log, bitmap) && 241 !inet_is_reserved_local_port(snum)) 242 goto found; 243 snum += rand; 244 } while (snum != first); 245 spin_unlock_bh(&hslot->lock); 246 } while (++first != last); 247 goto fail; 248 } else { 249 hslot = udp_hashslot(udptable, net, snum); 250 spin_lock_bh(&hslot->lock); 251 if (hslot->count > 10) { 252 int exist; 253 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 254 255 slot2 &= udptable->mask; 256 hash2_nulladdr &= udptable->mask; 257 258 hslot2 = udp_hashslot2(udptable, slot2); 259 if (hslot->count < hslot2->count) 260 goto scan_primary_hash; 261 262 exist = udp_lib_lport_inuse2(net, snum, hslot2, 263 sk, saddr_comp); 264 if (!exist && (hash2_nulladdr != slot2)) { 265 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 266 exist = udp_lib_lport_inuse2(net, snum, hslot2, 267 sk, saddr_comp); 268 } 269 if (exist) 270 goto fail_unlock; 271 else 272 goto found; 273 } 274 scan_primary_hash: 275 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 276 saddr_comp, 0)) 277 goto fail_unlock; 278 } 279 found: 280 inet_sk(sk)->inet_num = snum; 281 udp_sk(sk)->udp_port_hash = snum; 282 udp_sk(sk)->udp_portaddr_hash ^= snum; 283 if (sk_unhashed(sk)) { 284 sk_nulls_add_node_rcu(sk, &hslot->head); 285 hslot->count++; 286 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 287 288 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 289 spin_lock(&hslot2->lock); 290 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 291 &hslot2->head); 292 hslot2->count++; 293 spin_unlock(&hslot2->lock); 294 } 295 error = 0; 296 fail_unlock: 297 spin_unlock_bh(&hslot->lock); 298 fail: 299 return error; 300 } 301 EXPORT_SYMBOL(udp_lib_get_port); 302 303 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 304 { 305 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 306 307 return (!ipv6_only_sock(sk2) && 308 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr || 309 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr)); 310 } 311 312 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr, 313 unsigned int port) 314 { 315 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 316 } 317 318 int udp_v4_get_port(struct sock *sk, unsigned short snum) 319 { 320 unsigned int hash2_nulladdr = 321 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 322 unsigned int hash2_partial = 323 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 324 325 /* precompute partial secondary hash */ 326 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 327 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr); 328 } 329 330 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr, 331 unsigned short hnum, 332 __be16 sport, __be32 daddr, __be16 dport, int dif) 333 { 334 int score = -1; 335 336 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && 337 !ipv6_only_sock(sk)) { 338 struct inet_sock *inet = inet_sk(sk); 339 340 score = (sk->sk_family == PF_INET ? 1 : 0); 341 if (inet->inet_rcv_saddr) { 342 if (inet->inet_rcv_saddr != daddr) 343 return -1; 344 score += 2; 345 } 346 if (inet->inet_daddr) { 347 if (inet->inet_daddr != saddr) 348 return -1; 349 score += 2; 350 } 351 if (inet->inet_dport) { 352 if (inet->inet_dport != sport) 353 return -1; 354 score += 2; 355 } 356 if (sk->sk_bound_dev_if) { 357 if (sk->sk_bound_dev_if != dif) 358 return -1; 359 score += 2; 360 } 361 } 362 return score; 363 } 364 365 /* 366 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num) 367 */ 368 #define SCORE2_MAX (1 + 2 + 2 + 2) 369 static inline int compute_score2(struct sock *sk, struct net *net, 370 __be32 saddr, __be16 sport, 371 __be32 daddr, unsigned int hnum, int dif) 372 { 373 int score = -1; 374 375 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) { 376 struct inet_sock *inet = inet_sk(sk); 377 378 if (inet->inet_rcv_saddr != daddr) 379 return -1; 380 if (inet->inet_num != hnum) 381 return -1; 382 383 score = (sk->sk_family == PF_INET ? 1 : 0); 384 if (inet->inet_daddr) { 385 if (inet->inet_daddr != saddr) 386 return -1; 387 score += 2; 388 } 389 if (inet->inet_dport) { 390 if (inet->inet_dport != sport) 391 return -1; 392 score += 2; 393 } 394 if (sk->sk_bound_dev_if) { 395 if (sk->sk_bound_dev_if != dif) 396 return -1; 397 score += 2; 398 } 399 } 400 return score; 401 } 402 403 404 /* called with read_rcu_lock() */ 405 static struct sock *udp4_lib_lookup2(struct net *net, 406 __be32 saddr, __be16 sport, 407 __be32 daddr, unsigned int hnum, int dif, 408 struct udp_hslot *hslot2, unsigned int slot2) 409 { 410 struct sock *sk, *result; 411 struct hlist_nulls_node *node; 412 int score, badness; 413 414 begin: 415 result = NULL; 416 badness = -1; 417 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { 418 score = compute_score2(sk, net, saddr, sport, 419 daddr, hnum, dif); 420 if (score > badness) { 421 result = sk; 422 badness = score; 423 if (score == SCORE2_MAX) 424 goto exact_match; 425 } 426 } 427 /* 428 * if the nulls value we got at the end of this lookup is 429 * not the expected one, we must restart lookup. 430 * We probably met an item that was moved to another chain. 431 */ 432 if (get_nulls_value(node) != slot2) 433 goto begin; 434 435 if (result) { 436 exact_match: 437 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 438 result = NULL; 439 else if (unlikely(compute_score2(result, net, saddr, sport, 440 daddr, hnum, dif) < badness)) { 441 sock_put(result); 442 goto begin; 443 } 444 } 445 return result; 446 } 447 448 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 449 * harder than this. -DaveM 450 */ 451 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 452 __be16 sport, __be32 daddr, __be16 dport, 453 int dif, struct udp_table *udptable) 454 { 455 struct sock *sk, *result; 456 struct hlist_nulls_node *node; 457 unsigned short hnum = ntohs(dport); 458 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); 459 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; 460 int score, badness; 461 462 rcu_read_lock(); 463 if (hslot->count > 10) { 464 hash2 = udp4_portaddr_hash(net, daddr, hnum); 465 slot2 = hash2 & udptable->mask; 466 hslot2 = &udptable->hash2[slot2]; 467 if (hslot->count < hslot2->count) 468 goto begin; 469 470 result = udp4_lib_lookup2(net, saddr, sport, 471 daddr, hnum, dif, 472 hslot2, slot2); 473 if (!result) { 474 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 475 slot2 = hash2 & udptable->mask; 476 hslot2 = &udptable->hash2[slot2]; 477 if (hslot->count < hslot2->count) 478 goto begin; 479 480 result = udp4_lib_lookup2(net, saddr, sport, 481 htonl(INADDR_ANY), hnum, dif, 482 hslot2, slot2); 483 } 484 rcu_read_unlock(); 485 return result; 486 } 487 begin: 488 result = NULL; 489 badness = -1; 490 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 491 score = compute_score(sk, net, saddr, hnum, sport, 492 daddr, dport, dif); 493 if (score > badness) { 494 result = sk; 495 badness = score; 496 } 497 } 498 /* 499 * if the nulls value we got at the end of this lookup is 500 * not the expected one, we must restart lookup. 501 * We probably met an item that was moved to another chain. 502 */ 503 if (get_nulls_value(node) != slot) 504 goto begin; 505 506 if (result) { 507 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 508 result = NULL; 509 else if (unlikely(compute_score(result, net, saddr, hnum, sport, 510 daddr, dport, dif) < badness)) { 511 sock_put(result); 512 goto begin; 513 } 514 } 515 rcu_read_unlock(); 516 return result; 517 } 518 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 519 520 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 521 __be16 sport, __be16 dport, 522 struct udp_table *udptable) 523 { 524 struct sock *sk; 525 const struct iphdr *iph = ip_hdr(skb); 526 527 if (unlikely(sk = skb_steal_sock(skb))) 528 return sk; 529 else 530 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, 531 iph->daddr, dport, inet_iif(skb), 532 udptable); 533 } 534 535 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 536 __be32 daddr, __be16 dport, int dif) 537 { 538 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); 539 } 540 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 541 542 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk, 543 __be16 loc_port, __be32 loc_addr, 544 __be16 rmt_port, __be32 rmt_addr, 545 int dif) 546 { 547 struct hlist_nulls_node *node; 548 struct sock *s = sk; 549 unsigned short hnum = ntohs(loc_port); 550 551 sk_nulls_for_each_from(s, node) { 552 struct inet_sock *inet = inet_sk(s); 553 554 if (!net_eq(sock_net(s), net) || 555 udp_sk(s)->udp_port_hash != hnum || 556 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 557 (inet->inet_dport != rmt_port && inet->inet_dport) || 558 (inet->inet_rcv_saddr && 559 inet->inet_rcv_saddr != loc_addr) || 560 ipv6_only_sock(s) || 561 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) 562 continue; 563 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) 564 continue; 565 goto found; 566 } 567 s = NULL; 568 found: 569 return s; 570 } 571 572 /* 573 * This routine is called by the ICMP module when it gets some 574 * sort of error condition. If err < 0 then the socket should 575 * be closed and the error returned to the user. If err > 0 576 * it's just the icmp type << 8 | icmp code. 577 * Header points to the ip header of the error packet. We move 578 * on past this. Then (as it used to claim before adjustment) 579 * header points to the first 8 bytes of the udp header. We need 580 * to find the appropriate port. 581 */ 582 583 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 584 { 585 struct inet_sock *inet; 586 const struct iphdr *iph = (const struct iphdr *)skb->data; 587 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 588 const int type = icmp_hdr(skb)->type; 589 const int code = icmp_hdr(skb)->code; 590 struct sock *sk; 591 int harderr; 592 int err; 593 struct net *net = dev_net(skb->dev); 594 595 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 596 iph->saddr, uh->source, skb->dev->ifindex, udptable); 597 if (sk == NULL) { 598 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 599 return; /* No socket for error */ 600 } 601 602 err = 0; 603 harderr = 0; 604 inet = inet_sk(sk); 605 606 switch (type) { 607 default: 608 case ICMP_TIME_EXCEEDED: 609 err = EHOSTUNREACH; 610 break; 611 case ICMP_SOURCE_QUENCH: 612 goto out; 613 case ICMP_PARAMETERPROB: 614 err = EPROTO; 615 harderr = 1; 616 break; 617 case ICMP_DEST_UNREACH: 618 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 619 ipv4_sk_update_pmtu(skb, sk, info); 620 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 621 err = EMSGSIZE; 622 harderr = 1; 623 break; 624 } 625 goto out; 626 } 627 err = EHOSTUNREACH; 628 if (code <= NR_ICMP_UNREACH) { 629 harderr = icmp_err_convert[code].fatal; 630 err = icmp_err_convert[code].errno; 631 } 632 break; 633 case ICMP_REDIRECT: 634 ipv4_sk_redirect(skb, sk); 635 break; 636 } 637 638 /* 639 * RFC1122: OK. Passes ICMP errors back to application, as per 640 * 4.1.3.3. 641 */ 642 if (!inet->recverr) { 643 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 644 goto out; 645 } else 646 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 647 648 sk->sk_err = err; 649 sk->sk_error_report(sk); 650 out: 651 sock_put(sk); 652 } 653 654 void udp_err(struct sk_buff *skb, u32 info) 655 { 656 __udp4_lib_err(skb, info, &udp_table); 657 } 658 659 /* 660 * Throw away all pending data and cancel the corking. Socket is locked. 661 */ 662 void udp_flush_pending_frames(struct sock *sk) 663 { 664 struct udp_sock *up = udp_sk(sk); 665 666 if (up->pending) { 667 up->len = 0; 668 up->pending = 0; 669 ip_flush_pending_frames(sk); 670 } 671 } 672 EXPORT_SYMBOL(udp_flush_pending_frames); 673 674 /** 675 * udp4_hwcsum - handle outgoing HW checksumming 676 * @skb: sk_buff containing the filled-in UDP header 677 * (checksum field must be zeroed out) 678 * @src: source IP address 679 * @dst: destination IP address 680 */ 681 static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 682 { 683 struct udphdr *uh = udp_hdr(skb); 684 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 685 int offset = skb_transport_offset(skb); 686 int len = skb->len - offset; 687 int hlen = len; 688 __wsum csum = 0; 689 690 if (!frags) { 691 /* 692 * Only one fragment on the socket. 693 */ 694 skb->csum_start = skb_transport_header(skb) - skb->head; 695 skb->csum_offset = offsetof(struct udphdr, check); 696 uh->check = ~csum_tcpudp_magic(src, dst, len, 697 IPPROTO_UDP, 0); 698 } else { 699 /* 700 * HW-checksum won't work as there are two or more 701 * fragments on the socket so that all csums of sk_buffs 702 * should be together 703 */ 704 do { 705 csum = csum_add(csum, frags->csum); 706 hlen -= frags->len; 707 } while ((frags = frags->next)); 708 709 csum = skb_checksum(skb, offset, hlen, csum); 710 skb->ip_summed = CHECKSUM_NONE; 711 712 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 713 if (uh->check == 0) 714 uh->check = CSUM_MANGLED_0; 715 } 716 } 717 718 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) 719 { 720 struct sock *sk = skb->sk; 721 struct inet_sock *inet = inet_sk(sk); 722 struct udphdr *uh; 723 int err = 0; 724 int is_udplite = IS_UDPLITE(sk); 725 int offset = skb_transport_offset(skb); 726 int len = skb->len - offset; 727 __wsum csum = 0; 728 729 /* 730 * Create a UDP header 731 */ 732 uh = udp_hdr(skb); 733 uh->source = inet->inet_sport; 734 uh->dest = fl4->fl4_dport; 735 uh->len = htons(len); 736 uh->check = 0; 737 738 if (is_udplite) /* UDP-Lite */ 739 csum = udplite_csum(skb); 740 741 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ 742 743 skb->ip_summed = CHECKSUM_NONE; 744 goto send; 745 746 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 747 748 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 749 goto send; 750 751 } else 752 csum = udp_csum(skb); 753 754 /* add protocol-dependent pseudo-header */ 755 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 756 sk->sk_protocol, csum); 757 if (uh->check == 0) 758 uh->check = CSUM_MANGLED_0; 759 760 send: 761 err = ip_send_skb(sock_net(sk), skb); 762 if (err) { 763 if (err == -ENOBUFS && !inet->recverr) { 764 UDP_INC_STATS_USER(sock_net(sk), 765 UDP_MIB_SNDBUFERRORS, is_udplite); 766 err = 0; 767 } 768 } else 769 UDP_INC_STATS_USER(sock_net(sk), 770 UDP_MIB_OUTDATAGRAMS, is_udplite); 771 return err; 772 } 773 774 /* 775 * Push out all pending data as one UDP datagram. Socket is locked. 776 */ 777 static int udp_push_pending_frames(struct sock *sk) 778 { 779 struct udp_sock *up = udp_sk(sk); 780 struct inet_sock *inet = inet_sk(sk); 781 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 782 struct sk_buff *skb; 783 int err = 0; 784 785 skb = ip_finish_skb(sk, fl4); 786 if (!skb) 787 goto out; 788 789 err = udp_send_skb(skb, fl4); 790 791 out: 792 up->len = 0; 793 up->pending = 0; 794 return err; 795 } 796 797 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 798 size_t len) 799 { 800 struct inet_sock *inet = inet_sk(sk); 801 struct udp_sock *up = udp_sk(sk); 802 struct flowi4 fl4_stack; 803 struct flowi4 *fl4; 804 int ulen = len; 805 struct ipcm_cookie ipc; 806 struct rtable *rt = NULL; 807 int free = 0; 808 int connected = 0; 809 __be32 daddr, faddr, saddr; 810 __be16 dport; 811 u8 tos; 812 int err, is_udplite = IS_UDPLITE(sk); 813 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 814 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 815 struct sk_buff *skb; 816 struct ip_options_data opt_copy; 817 818 if (len > 0xFFFF) 819 return -EMSGSIZE; 820 821 /* 822 * Check the flags. 823 */ 824 825 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 826 return -EOPNOTSUPP; 827 828 ipc.opt = NULL; 829 ipc.tx_flags = 0; 830 831 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 832 833 fl4 = &inet->cork.fl.u.ip4; 834 if (up->pending) { 835 /* 836 * There are pending frames. 837 * The socket lock must be held while it's corked. 838 */ 839 lock_sock(sk); 840 if (likely(up->pending)) { 841 if (unlikely(up->pending != AF_INET)) { 842 release_sock(sk); 843 return -EINVAL; 844 } 845 goto do_append_data; 846 } 847 release_sock(sk); 848 } 849 ulen += sizeof(struct udphdr); 850 851 /* 852 * Get and verify the address. 853 */ 854 if (msg->msg_name) { 855 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name; 856 if (msg->msg_namelen < sizeof(*usin)) 857 return -EINVAL; 858 if (usin->sin_family != AF_INET) { 859 if (usin->sin_family != AF_UNSPEC) 860 return -EAFNOSUPPORT; 861 } 862 863 daddr = usin->sin_addr.s_addr; 864 dport = usin->sin_port; 865 if (dport == 0) 866 return -EINVAL; 867 } else { 868 if (sk->sk_state != TCP_ESTABLISHED) 869 return -EDESTADDRREQ; 870 daddr = inet->inet_daddr; 871 dport = inet->inet_dport; 872 /* Open fast path for connected socket. 873 Route will not be used, if at least one option is set. 874 */ 875 connected = 1; 876 } 877 ipc.addr = inet->inet_saddr; 878 879 ipc.oif = sk->sk_bound_dev_if; 880 err = sock_tx_timestamp(sk, &ipc.tx_flags); 881 if (err) 882 return err; 883 if (msg->msg_controllen) { 884 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 885 if (err) 886 return err; 887 if (ipc.opt) 888 free = 1; 889 connected = 0; 890 } 891 if (!ipc.opt) { 892 struct ip_options_rcu *inet_opt; 893 894 rcu_read_lock(); 895 inet_opt = rcu_dereference(inet->inet_opt); 896 if (inet_opt) { 897 memcpy(&opt_copy, inet_opt, 898 sizeof(*inet_opt) + inet_opt->opt.optlen); 899 ipc.opt = &opt_copy.opt; 900 } 901 rcu_read_unlock(); 902 } 903 904 saddr = ipc.addr; 905 ipc.addr = faddr = daddr; 906 907 if (ipc.opt && ipc.opt->opt.srr) { 908 if (!daddr) 909 return -EINVAL; 910 faddr = ipc.opt->opt.faddr; 911 connected = 0; 912 } 913 tos = RT_TOS(inet->tos); 914 if (sock_flag(sk, SOCK_LOCALROUTE) || 915 (msg->msg_flags & MSG_DONTROUTE) || 916 (ipc.opt && ipc.opt->opt.is_strictroute)) { 917 tos |= RTO_ONLINK; 918 connected = 0; 919 } 920 921 if (ipv4_is_multicast(daddr)) { 922 if (!ipc.oif) 923 ipc.oif = inet->mc_index; 924 if (!saddr) 925 saddr = inet->mc_addr; 926 connected = 0; 927 } else if (!ipc.oif) 928 ipc.oif = inet->uc_index; 929 930 if (connected) 931 rt = (struct rtable *)sk_dst_check(sk, 0); 932 933 if (rt == NULL) { 934 struct net *net = sock_net(sk); 935 936 fl4 = &fl4_stack; 937 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, 938 RT_SCOPE_UNIVERSE, sk->sk_protocol, 939 inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP, 940 faddr, saddr, dport, inet->inet_sport); 941 942 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 943 rt = ip_route_output_flow(net, fl4, sk); 944 if (IS_ERR(rt)) { 945 err = PTR_ERR(rt); 946 rt = NULL; 947 if (err == -ENETUNREACH) 948 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 949 goto out; 950 } 951 952 err = -EACCES; 953 if ((rt->rt_flags & RTCF_BROADCAST) && 954 !sock_flag(sk, SOCK_BROADCAST)) 955 goto out; 956 if (connected) 957 sk_dst_set(sk, dst_clone(&rt->dst)); 958 } 959 960 if (msg->msg_flags&MSG_CONFIRM) 961 goto do_confirm; 962 back_from_confirm: 963 964 saddr = fl4->saddr; 965 if (!ipc.addr) 966 daddr = ipc.addr = fl4->daddr; 967 968 /* Lockless fast path for the non-corking case. */ 969 if (!corkreq) { 970 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen, 971 sizeof(struct udphdr), &ipc, &rt, 972 msg->msg_flags); 973 err = PTR_ERR(skb); 974 if (skb && !IS_ERR(skb)) 975 err = udp_send_skb(skb, fl4); 976 goto out; 977 } 978 979 lock_sock(sk); 980 if (unlikely(up->pending)) { 981 /* The socket is already corked while preparing it. */ 982 /* ... which is an evident application bug. --ANK */ 983 release_sock(sk); 984 985 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n")); 986 err = -EINVAL; 987 goto out; 988 } 989 /* 990 * Now cork the socket to pend data. 991 */ 992 fl4 = &inet->cork.fl.u.ip4; 993 fl4->daddr = daddr; 994 fl4->saddr = saddr; 995 fl4->fl4_dport = dport; 996 fl4->fl4_sport = inet->inet_sport; 997 up->pending = AF_INET; 998 999 do_append_data: 1000 up->len += ulen; 1001 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen, 1002 sizeof(struct udphdr), &ipc, &rt, 1003 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1004 if (err) 1005 udp_flush_pending_frames(sk); 1006 else if (!corkreq) 1007 err = udp_push_pending_frames(sk); 1008 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1009 up->pending = 0; 1010 release_sock(sk); 1011 1012 out: 1013 ip_rt_put(rt); 1014 if (free) 1015 kfree(ipc.opt); 1016 if (!err) 1017 return len; 1018 /* 1019 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1020 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1021 * we don't have a good statistic (IpOutDiscards but it can be too many 1022 * things). We could add another new stat but at least for now that 1023 * seems like overkill. 1024 */ 1025 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1026 UDP_INC_STATS_USER(sock_net(sk), 1027 UDP_MIB_SNDBUFERRORS, is_udplite); 1028 } 1029 return err; 1030 1031 do_confirm: 1032 dst_confirm(&rt->dst); 1033 if (!(msg->msg_flags&MSG_PROBE) || len) 1034 goto back_from_confirm; 1035 err = 0; 1036 goto out; 1037 } 1038 EXPORT_SYMBOL(udp_sendmsg); 1039 1040 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1041 size_t size, int flags) 1042 { 1043 struct inet_sock *inet = inet_sk(sk); 1044 struct udp_sock *up = udp_sk(sk); 1045 int ret; 1046 1047 if (!up->pending) { 1048 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1049 1050 /* Call udp_sendmsg to specify destination address which 1051 * sendpage interface can't pass. 1052 * This will succeed only when the socket is connected. 1053 */ 1054 ret = udp_sendmsg(NULL, sk, &msg, 0); 1055 if (ret < 0) 1056 return ret; 1057 } 1058 1059 lock_sock(sk); 1060 1061 if (unlikely(!up->pending)) { 1062 release_sock(sk); 1063 1064 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n")); 1065 return -EINVAL; 1066 } 1067 1068 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1069 page, offset, size, flags); 1070 if (ret == -EOPNOTSUPP) { 1071 release_sock(sk); 1072 return sock_no_sendpage(sk->sk_socket, page, offset, 1073 size, flags); 1074 } 1075 if (ret < 0) { 1076 udp_flush_pending_frames(sk); 1077 goto out; 1078 } 1079 1080 up->len += size; 1081 if (!(up->corkflag || (flags&MSG_MORE))) 1082 ret = udp_push_pending_frames(sk); 1083 if (!ret) 1084 ret = size; 1085 out: 1086 release_sock(sk); 1087 return ret; 1088 } 1089 1090 1091 /** 1092 * first_packet_length - return length of first packet in receive queue 1093 * @sk: socket 1094 * 1095 * Drops all bad checksum frames, until a valid one is found. 1096 * Returns the length of found skb, or 0 if none is found. 1097 */ 1098 static unsigned int first_packet_length(struct sock *sk) 1099 { 1100 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue; 1101 struct sk_buff *skb; 1102 unsigned int res; 1103 1104 __skb_queue_head_init(&list_kill); 1105 1106 spin_lock_bh(&rcvq->lock); 1107 while ((skb = skb_peek(rcvq)) != NULL && 1108 udp_lib_checksum_complete(skb)) { 1109 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1110 IS_UDPLITE(sk)); 1111 atomic_inc(&sk->sk_drops); 1112 __skb_unlink(skb, rcvq); 1113 __skb_queue_tail(&list_kill, skb); 1114 } 1115 res = skb ? skb->len : 0; 1116 spin_unlock_bh(&rcvq->lock); 1117 1118 if (!skb_queue_empty(&list_kill)) { 1119 bool slow = lock_sock_fast(sk); 1120 1121 __skb_queue_purge(&list_kill); 1122 sk_mem_reclaim_partial(sk); 1123 unlock_sock_fast(sk, slow); 1124 } 1125 return res; 1126 } 1127 1128 /* 1129 * IOCTL requests applicable to the UDP protocol 1130 */ 1131 1132 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1133 { 1134 switch (cmd) { 1135 case SIOCOUTQ: 1136 { 1137 int amount = sk_wmem_alloc_get(sk); 1138 1139 return put_user(amount, (int __user *)arg); 1140 } 1141 1142 case SIOCINQ: 1143 { 1144 unsigned int amount = first_packet_length(sk); 1145 1146 if (amount) 1147 /* 1148 * We will only return the amount 1149 * of this packet since that is all 1150 * that will be read. 1151 */ 1152 amount -= sizeof(struct udphdr); 1153 1154 return put_user(amount, (int __user *)arg); 1155 } 1156 1157 default: 1158 return -ENOIOCTLCMD; 1159 } 1160 1161 return 0; 1162 } 1163 EXPORT_SYMBOL(udp_ioctl); 1164 1165 /* 1166 * This should be easy, if there is something there we 1167 * return it, otherwise we block. 1168 */ 1169 1170 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1171 size_t len, int noblock, int flags, int *addr_len) 1172 { 1173 struct inet_sock *inet = inet_sk(sk); 1174 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 1175 struct sk_buff *skb; 1176 unsigned int ulen, copied; 1177 int peeked, off = 0; 1178 int err; 1179 int is_udplite = IS_UDPLITE(sk); 1180 bool slow; 1181 1182 /* 1183 * Check any passed addresses 1184 */ 1185 if (addr_len) 1186 *addr_len = sizeof(*sin); 1187 1188 if (flags & MSG_ERRQUEUE) 1189 return ip_recv_error(sk, msg, len); 1190 1191 try_again: 1192 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), 1193 &peeked, &off, &err); 1194 if (!skb) 1195 goto out; 1196 1197 ulen = skb->len - sizeof(struct udphdr); 1198 copied = len; 1199 if (copied > ulen) 1200 copied = ulen; 1201 else if (copied < ulen) 1202 msg->msg_flags |= MSG_TRUNC; 1203 1204 /* 1205 * If checksum is needed at all, try to do it while copying the 1206 * data. If the data is truncated, or if we only want a partial 1207 * coverage checksum (UDP-Lite), do it before the copy. 1208 */ 1209 1210 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { 1211 if (udp_lib_checksum_complete(skb)) 1212 goto csum_copy_err; 1213 } 1214 1215 if (skb_csum_unnecessary(skb)) 1216 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), 1217 msg->msg_iov, copied); 1218 else { 1219 err = skb_copy_and_csum_datagram_iovec(skb, 1220 sizeof(struct udphdr), 1221 msg->msg_iov); 1222 1223 if (err == -EINVAL) 1224 goto csum_copy_err; 1225 } 1226 1227 if (unlikely(err)) { 1228 trace_kfree_skb(skb, udp_recvmsg); 1229 if (!peeked) { 1230 atomic_inc(&sk->sk_drops); 1231 UDP_INC_STATS_USER(sock_net(sk), 1232 UDP_MIB_INERRORS, is_udplite); 1233 } 1234 goto out_free; 1235 } 1236 1237 if (!peeked) 1238 UDP_INC_STATS_USER(sock_net(sk), 1239 UDP_MIB_INDATAGRAMS, is_udplite); 1240 1241 sock_recv_ts_and_drops(msg, sk, skb); 1242 1243 /* Copy the address. */ 1244 if (sin) { 1245 sin->sin_family = AF_INET; 1246 sin->sin_port = udp_hdr(skb)->source; 1247 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1248 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1249 } 1250 if (inet->cmsg_flags) 1251 ip_cmsg_recv(msg, skb); 1252 1253 err = copied; 1254 if (flags & MSG_TRUNC) 1255 err = ulen; 1256 1257 out_free: 1258 skb_free_datagram_locked(sk, skb); 1259 out: 1260 return err; 1261 1262 csum_copy_err: 1263 slow = lock_sock_fast(sk); 1264 if (!skb_kill_datagram(sk, skb, flags)) 1265 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1266 unlock_sock_fast(sk, slow); 1267 1268 if (noblock) 1269 return -EAGAIN; 1270 1271 /* starting over for a new packet */ 1272 msg->msg_flags &= ~MSG_TRUNC; 1273 goto try_again; 1274 } 1275 1276 1277 int udp_disconnect(struct sock *sk, int flags) 1278 { 1279 struct inet_sock *inet = inet_sk(sk); 1280 /* 1281 * 1003.1g - break association. 1282 */ 1283 1284 sk->sk_state = TCP_CLOSE; 1285 inet->inet_daddr = 0; 1286 inet->inet_dport = 0; 1287 sock_rps_reset_rxhash(sk); 1288 sk->sk_bound_dev_if = 0; 1289 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1290 inet_reset_saddr(sk); 1291 1292 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1293 sk->sk_prot->unhash(sk); 1294 inet->inet_sport = 0; 1295 } 1296 sk_dst_reset(sk); 1297 return 0; 1298 } 1299 EXPORT_SYMBOL(udp_disconnect); 1300 1301 void udp_lib_unhash(struct sock *sk) 1302 { 1303 if (sk_hashed(sk)) { 1304 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1305 struct udp_hslot *hslot, *hslot2; 1306 1307 hslot = udp_hashslot(udptable, sock_net(sk), 1308 udp_sk(sk)->udp_port_hash); 1309 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1310 1311 spin_lock_bh(&hslot->lock); 1312 if (sk_nulls_del_node_init_rcu(sk)) { 1313 hslot->count--; 1314 inet_sk(sk)->inet_num = 0; 1315 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1316 1317 spin_lock(&hslot2->lock); 1318 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1319 hslot2->count--; 1320 spin_unlock(&hslot2->lock); 1321 } 1322 spin_unlock_bh(&hslot->lock); 1323 } 1324 } 1325 EXPORT_SYMBOL(udp_lib_unhash); 1326 1327 /* 1328 * inet_rcv_saddr was changed, we must rehash secondary hash 1329 */ 1330 void udp_lib_rehash(struct sock *sk, u16 newhash) 1331 { 1332 if (sk_hashed(sk)) { 1333 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1334 struct udp_hslot *hslot, *hslot2, *nhslot2; 1335 1336 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1337 nhslot2 = udp_hashslot2(udptable, newhash); 1338 udp_sk(sk)->udp_portaddr_hash = newhash; 1339 if (hslot2 != nhslot2) { 1340 hslot = udp_hashslot(udptable, sock_net(sk), 1341 udp_sk(sk)->udp_port_hash); 1342 /* we must lock primary chain too */ 1343 spin_lock_bh(&hslot->lock); 1344 1345 spin_lock(&hslot2->lock); 1346 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1347 hslot2->count--; 1348 spin_unlock(&hslot2->lock); 1349 1350 spin_lock(&nhslot2->lock); 1351 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1352 &nhslot2->head); 1353 nhslot2->count++; 1354 spin_unlock(&nhslot2->lock); 1355 1356 spin_unlock_bh(&hslot->lock); 1357 } 1358 } 1359 } 1360 EXPORT_SYMBOL(udp_lib_rehash); 1361 1362 static void udp_v4_rehash(struct sock *sk) 1363 { 1364 u16 new_hash = udp4_portaddr_hash(sock_net(sk), 1365 inet_sk(sk)->inet_rcv_saddr, 1366 inet_sk(sk)->inet_num); 1367 udp_lib_rehash(sk, new_hash); 1368 } 1369 1370 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1371 { 1372 int rc; 1373 1374 if (inet_sk(sk)->inet_daddr) 1375 sock_rps_save_rxhash(sk, skb); 1376 1377 rc = sock_queue_rcv_skb(sk, skb); 1378 if (rc < 0) { 1379 int is_udplite = IS_UDPLITE(sk); 1380 1381 /* Note that an ENOMEM error is charged twice */ 1382 if (rc == -ENOMEM) 1383 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1384 is_udplite); 1385 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1386 kfree_skb(skb); 1387 trace_udp_fail_queue_rcv_skb(rc, sk); 1388 return -1; 1389 } 1390 1391 return 0; 1392 1393 } 1394 1395 static struct static_key udp_encap_needed __read_mostly; 1396 void udp_encap_enable(void) 1397 { 1398 if (!static_key_enabled(&udp_encap_needed)) 1399 static_key_slow_inc(&udp_encap_needed); 1400 } 1401 EXPORT_SYMBOL(udp_encap_enable); 1402 1403 /* returns: 1404 * -1: error 1405 * 0: success 1406 * >0: "udp encap" protocol resubmission 1407 * 1408 * Note that in the success and error cases, the skb is assumed to 1409 * have either been requeued or freed. 1410 */ 1411 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1412 { 1413 struct udp_sock *up = udp_sk(sk); 1414 int rc; 1415 int is_udplite = IS_UDPLITE(sk); 1416 1417 /* 1418 * Charge it to the socket, dropping if the queue is full. 1419 */ 1420 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1421 goto drop; 1422 nf_reset(skb); 1423 1424 if (static_key_false(&udp_encap_needed) && up->encap_type) { 1425 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 1426 1427 /* 1428 * This is an encapsulation socket so pass the skb to 1429 * the socket's udp_encap_rcv() hook. Otherwise, just 1430 * fall through and pass this up the UDP socket. 1431 * up->encap_rcv() returns the following value: 1432 * =0 if skb was successfully passed to the encap 1433 * handler or was discarded by it. 1434 * >0 if skb should be passed on to UDP. 1435 * <0 if skb should be resubmitted as proto -N 1436 */ 1437 1438 /* if we're overly short, let UDP handle it */ 1439 encap_rcv = ACCESS_ONCE(up->encap_rcv); 1440 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) { 1441 int ret; 1442 1443 ret = encap_rcv(sk, skb); 1444 if (ret <= 0) { 1445 UDP_INC_STATS_BH(sock_net(sk), 1446 UDP_MIB_INDATAGRAMS, 1447 is_udplite); 1448 return -ret; 1449 } 1450 } 1451 1452 /* FALLTHROUGH -- it's a UDP Packet */ 1453 } 1454 1455 /* 1456 * UDP-Lite specific tests, ignored on UDP sockets 1457 */ 1458 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1459 1460 /* 1461 * MIB statistics other than incrementing the error count are 1462 * disabled for the following two types of errors: these depend 1463 * on the application settings, not on the functioning of the 1464 * protocol stack as such. 1465 * 1466 * RFC 3828 here recommends (sec 3.3): "There should also be a 1467 * way ... to ... at least let the receiving application block 1468 * delivery of packets with coverage values less than a value 1469 * provided by the application." 1470 */ 1471 if (up->pcrlen == 0) { /* full coverage was set */ 1472 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n", 1473 UDP_SKB_CB(skb)->cscov, skb->len); 1474 goto drop; 1475 } 1476 /* The next case involves violating the min. coverage requested 1477 * by the receiver. This is subtle: if receiver wants x and x is 1478 * greater than the buffersize/MTU then receiver will complain 1479 * that it wants x while sender emits packets of smaller size y. 1480 * Therefore the above ...()->partial_cov statement is essential. 1481 */ 1482 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1483 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n", 1484 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1485 goto drop; 1486 } 1487 } 1488 1489 if (rcu_access_pointer(sk->sk_filter) && 1490 udp_lib_checksum_complete(skb)) 1491 goto drop; 1492 1493 1494 if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) 1495 goto drop; 1496 1497 rc = 0; 1498 1499 ipv4_pktinfo_prepare(skb); 1500 bh_lock_sock(sk); 1501 if (!sock_owned_by_user(sk)) 1502 rc = __udp_queue_rcv_skb(sk, skb); 1503 else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) { 1504 bh_unlock_sock(sk); 1505 goto drop; 1506 } 1507 bh_unlock_sock(sk); 1508 1509 return rc; 1510 1511 drop: 1512 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1513 atomic_inc(&sk->sk_drops); 1514 kfree_skb(skb); 1515 return -1; 1516 } 1517 1518 1519 static void flush_stack(struct sock **stack, unsigned int count, 1520 struct sk_buff *skb, unsigned int final) 1521 { 1522 unsigned int i; 1523 struct sk_buff *skb1 = NULL; 1524 struct sock *sk; 1525 1526 for (i = 0; i < count; i++) { 1527 sk = stack[i]; 1528 if (likely(skb1 == NULL)) 1529 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); 1530 1531 if (!skb1) { 1532 atomic_inc(&sk->sk_drops); 1533 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1534 IS_UDPLITE(sk)); 1535 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1536 IS_UDPLITE(sk)); 1537 } 1538 1539 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0) 1540 skb1 = NULL; 1541 } 1542 if (unlikely(skb1)) 1543 kfree_skb(skb1); 1544 } 1545 1546 /* 1547 * Multicasts and broadcasts go to each listener. 1548 * 1549 * Note: called only from the BH handler context. 1550 */ 1551 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 1552 struct udphdr *uh, 1553 __be32 saddr, __be32 daddr, 1554 struct udp_table *udptable) 1555 { 1556 struct sock *sk, *stack[256 / sizeof(struct sock *)]; 1557 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest)); 1558 int dif; 1559 unsigned int i, count = 0; 1560 1561 spin_lock(&hslot->lock); 1562 sk = sk_nulls_head(&hslot->head); 1563 dif = skb->dev->ifindex; 1564 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); 1565 while (sk) { 1566 stack[count++] = sk; 1567 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest, 1568 daddr, uh->source, saddr, dif); 1569 if (unlikely(count == ARRAY_SIZE(stack))) { 1570 if (!sk) 1571 break; 1572 flush_stack(stack, count, skb, ~0); 1573 count = 0; 1574 } 1575 } 1576 /* 1577 * before releasing chain lock, we must take a reference on sockets 1578 */ 1579 for (i = 0; i < count; i++) 1580 sock_hold(stack[i]); 1581 1582 spin_unlock(&hslot->lock); 1583 1584 /* 1585 * do the slow work with no lock held 1586 */ 1587 if (count) { 1588 flush_stack(stack, count, skb, count - 1); 1589 1590 for (i = 0; i < count; i++) 1591 sock_put(stack[i]); 1592 } else { 1593 kfree_skb(skb); 1594 } 1595 return 0; 1596 } 1597 1598 /* Initialize UDP checksum. If exited with zero value (success), 1599 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1600 * Otherwise, csum completion requires chacksumming packet body, 1601 * including udp header and folding it to skb->csum. 1602 */ 1603 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 1604 int proto) 1605 { 1606 const struct iphdr *iph; 1607 int err; 1608 1609 UDP_SKB_CB(skb)->partial_cov = 0; 1610 UDP_SKB_CB(skb)->cscov = skb->len; 1611 1612 if (proto == IPPROTO_UDPLITE) { 1613 err = udplite_checksum_init(skb, uh); 1614 if (err) 1615 return err; 1616 } 1617 1618 iph = ip_hdr(skb); 1619 if (uh->check == 0) { 1620 skb->ip_summed = CHECKSUM_UNNECESSARY; 1621 } else if (skb->ip_summed == CHECKSUM_COMPLETE) { 1622 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 1623 proto, skb->csum)) 1624 skb->ip_summed = CHECKSUM_UNNECESSARY; 1625 } 1626 if (!skb_csum_unnecessary(skb)) 1627 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, 1628 skb->len, proto, 0); 1629 /* Probably, we should checksum udp header (it should be in cache 1630 * in any case) and data in tiny packets (< rx copybreak). 1631 */ 1632 1633 return 0; 1634 } 1635 1636 /* 1637 * All we need to do is get the socket, and then do a checksum. 1638 */ 1639 1640 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 1641 int proto) 1642 { 1643 struct sock *sk; 1644 struct udphdr *uh; 1645 unsigned short ulen; 1646 struct rtable *rt = skb_rtable(skb); 1647 __be32 saddr, daddr; 1648 struct net *net = dev_net(skb->dev); 1649 1650 /* 1651 * Validate the packet. 1652 */ 1653 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1654 goto drop; /* No space for header. */ 1655 1656 uh = udp_hdr(skb); 1657 ulen = ntohs(uh->len); 1658 saddr = ip_hdr(skb)->saddr; 1659 daddr = ip_hdr(skb)->daddr; 1660 1661 if (ulen > skb->len) 1662 goto short_packet; 1663 1664 if (proto == IPPROTO_UDP) { 1665 /* UDP validates ulen. */ 1666 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1667 goto short_packet; 1668 uh = udp_hdr(skb); 1669 } 1670 1671 if (udp4_csum_init(skb, uh, proto)) 1672 goto csum_error; 1673 1674 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1675 return __udp4_lib_mcast_deliver(net, skb, uh, 1676 saddr, daddr, udptable); 1677 1678 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 1679 1680 if (sk != NULL) { 1681 int ret = udp_queue_rcv_skb(sk, skb); 1682 sock_put(sk); 1683 1684 /* a return value > 0 means to resubmit the input, but 1685 * it wants the return to be -protocol, or 0 1686 */ 1687 if (ret > 0) 1688 return -ret; 1689 return 0; 1690 } 1691 1692 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1693 goto drop; 1694 nf_reset(skb); 1695 1696 /* No socket. Drop packet silently, if checksum is wrong */ 1697 if (udp_lib_checksum_complete(skb)) 1698 goto csum_error; 1699 1700 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 1701 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1702 1703 /* 1704 * Hmm. We got an UDP packet to a port to which we 1705 * don't wanna listen. Ignore it. 1706 */ 1707 kfree_skb(skb); 1708 return 0; 1709 1710 short_packet: 1711 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 1712 proto == IPPROTO_UDPLITE ? "Lite" : "", 1713 &saddr, ntohs(uh->source), 1714 ulen, skb->len, 1715 &daddr, ntohs(uh->dest)); 1716 goto drop; 1717 1718 csum_error: 1719 /* 1720 * RFC1122: OK. Discards the bad packet silently (as far as 1721 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1722 */ 1723 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 1724 proto == IPPROTO_UDPLITE ? "Lite" : "", 1725 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 1726 ulen); 1727 drop: 1728 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1729 kfree_skb(skb); 1730 return 0; 1731 } 1732 1733 int udp_rcv(struct sk_buff *skb) 1734 { 1735 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 1736 } 1737 1738 void udp_destroy_sock(struct sock *sk) 1739 { 1740 bool slow = lock_sock_fast(sk); 1741 udp_flush_pending_frames(sk); 1742 unlock_sock_fast(sk, slow); 1743 } 1744 1745 /* 1746 * Socket option code for UDP 1747 */ 1748 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 1749 char __user *optval, unsigned int optlen, 1750 int (*push_pending_frames)(struct sock *)) 1751 { 1752 struct udp_sock *up = udp_sk(sk); 1753 int val; 1754 int err = 0; 1755 int is_udplite = IS_UDPLITE(sk); 1756 1757 if (optlen < sizeof(int)) 1758 return -EINVAL; 1759 1760 if (get_user(val, (int __user *)optval)) 1761 return -EFAULT; 1762 1763 switch (optname) { 1764 case UDP_CORK: 1765 if (val != 0) { 1766 up->corkflag = 1; 1767 } else { 1768 up->corkflag = 0; 1769 lock_sock(sk); 1770 (*push_pending_frames)(sk); 1771 release_sock(sk); 1772 } 1773 break; 1774 1775 case UDP_ENCAP: 1776 switch (val) { 1777 case 0: 1778 case UDP_ENCAP_ESPINUDP: 1779 case UDP_ENCAP_ESPINUDP_NON_IKE: 1780 up->encap_rcv = xfrm4_udp_encap_rcv; 1781 /* FALLTHROUGH */ 1782 case UDP_ENCAP_L2TPINUDP: 1783 up->encap_type = val; 1784 udp_encap_enable(); 1785 break; 1786 default: 1787 err = -ENOPROTOOPT; 1788 break; 1789 } 1790 break; 1791 1792 /* 1793 * UDP-Lite's partial checksum coverage (RFC 3828). 1794 */ 1795 /* The sender sets actual checksum coverage length via this option. 1796 * The case coverage > packet length is handled by send module. */ 1797 case UDPLITE_SEND_CSCOV: 1798 if (!is_udplite) /* Disable the option on UDP sockets */ 1799 return -ENOPROTOOPT; 1800 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 1801 val = 8; 1802 else if (val > USHRT_MAX) 1803 val = USHRT_MAX; 1804 up->pcslen = val; 1805 up->pcflag |= UDPLITE_SEND_CC; 1806 break; 1807 1808 /* The receiver specifies a minimum checksum coverage value. To make 1809 * sense, this should be set to at least 8 (as done below). If zero is 1810 * used, this again means full checksum coverage. */ 1811 case UDPLITE_RECV_CSCOV: 1812 if (!is_udplite) /* Disable the option on UDP sockets */ 1813 return -ENOPROTOOPT; 1814 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 1815 val = 8; 1816 else if (val > USHRT_MAX) 1817 val = USHRT_MAX; 1818 up->pcrlen = val; 1819 up->pcflag |= UDPLITE_RECV_CC; 1820 break; 1821 1822 default: 1823 err = -ENOPROTOOPT; 1824 break; 1825 } 1826 1827 return err; 1828 } 1829 EXPORT_SYMBOL(udp_lib_setsockopt); 1830 1831 int udp_setsockopt(struct sock *sk, int level, int optname, 1832 char __user *optval, unsigned int optlen) 1833 { 1834 if (level == SOL_UDP || level == SOL_UDPLITE) 1835 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1836 udp_push_pending_frames); 1837 return ip_setsockopt(sk, level, optname, optval, optlen); 1838 } 1839 1840 #ifdef CONFIG_COMPAT 1841 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 1842 char __user *optval, unsigned int optlen) 1843 { 1844 if (level == SOL_UDP || level == SOL_UDPLITE) 1845 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1846 udp_push_pending_frames); 1847 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 1848 } 1849 #endif 1850 1851 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 1852 char __user *optval, int __user *optlen) 1853 { 1854 struct udp_sock *up = udp_sk(sk); 1855 int val, len; 1856 1857 if (get_user(len, optlen)) 1858 return -EFAULT; 1859 1860 len = min_t(unsigned int, len, sizeof(int)); 1861 1862 if (len < 0) 1863 return -EINVAL; 1864 1865 switch (optname) { 1866 case UDP_CORK: 1867 val = up->corkflag; 1868 break; 1869 1870 case UDP_ENCAP: 1871 val = up->encap_type; 1872 break; 1873 1874 /* The following two cannot be changed on UDP sockets, the return is 1875 * always 0 (which corresponds to the full checksum coverage of UDP). */ 1876 case UDPLITE_SEND_CSCOV: 1877 val = up->pcslen; 1878 break; 1879 1880 case UDPLITE_RECV_CSCOV: 1881 val = up->pcrlen; 1882 break; 1883 1884 default: 1885 return -ENOPROTOOPT; 1886 } 1887 1888 if (put_user(len, optlen)) 1889 return -EFAULT; 1890 if (copy_to_user(optval, &val, len)) 1891 return -EFAULT; 1892 return 0; 1893 } 1894 EXPORT_SYMBOL(udp_lib_getsockopt); 1895 1896 int udp_getsockopt(struct sock *sk, int level, int optname, 1897 char __user *optval, int __user *optlen) 1898 { 1899 if (level == SOL_UDP || level == SOL_UDPLITE) 1900 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1901 return ip_getsockopt(sk, level, optname, optval, optlen); 1902 } 1903 1904 #ifdef CONFIG_COMPAT 1905 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 1906 char __user *optval, int __user *optlen) 1907 { 1908 if (level == SOL_UDP || level == SOL_UDPLITE) 1909 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1910 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 1911 } 1912 #endif 1913 /** 1914 * udp_poll - wait for a UDP event. 1915 * @file - file struct 1916 * @sock - socket 1917 * @wait - poll table 1918 * 1919 * This is same as datagram poll, except for the special case of 1920 * blocking sockets. If application is using a blocking fd 1921 * and a packet with checksum error is in the queue; 1922 * then it could get return from select indicating data available 1923 * but then block when reading it. Add special case code 1924 * to work around these arguably broken applications. 1925 */ 1926 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 1927 { 1928 unsigned int mask = datagram_poll(file, sock, wait); 1929 struct sock *sk = sock->sk; 1930 1931 /* Check for false positives due to checksum errors */ 1932 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 1933 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk)) 1934 mask &= ~(POLLIN | POLLRDNORM); 1935 1936 return mask; 1937 1938 } 1939 EXPORT_SYMBOL(udp_poll); 1940 1941 struct proto udp_prot = { 1942 .name = "UDP", 1943 .owner = THIS_MODULE, 1944 .close = udp_lib_close, 1945 .connect = ip4_datagram_connect, 1946 .disconnect = udp_disconnect, 1947 .ioctl = udp_ioctl, 1948 .destroy = udp_destroy_sock, 1949 .setsockopt = udp_setsockopt, 1950 .getsockopt = udp_getsockopt, 1951 .sendmsg = udp_sendmsg, 1952 .recvmsg = udp_recvmsg, 1953 .sendpage = udp_sendpage, 1954 .backlog_rcv = __udp_queue_rcv_skb, 1955 .hash = udp_lib_hash, 1956 .unhash = udp_lib_unhash, 1957 .rehash = udp_v4_rehash, 1958 .get_port = udp_v4_get_port, 1959 .memory_allocated = &udp_memory_allocated, 1960 .sysctl_mem = sysctl_udp_mem, 1961 .sysctl_wmem = &sysctl_udp_wmem_min, 1962 .sysctl_rmem = &sysctl_udp_rmem_min, 1963 .obj_size = sizeof(struct udp_sock), 1964 .slab_flags = SLAB_DESTROY_BY_RCU, 1965 .h.udp_table = &udp_table, 1966 #ifdef CONFIG_COMPAT 1967 .compat_setsockopt = compat_udp_setsockopt, 1968 .compat_getsockopt = compat_udp_getsockopt, 1969 #endif 1970 .clear_sk = sk_prot_clear_portaddr_nulls, 1971 }; 1972 EXPORT_SYMBOL(udp_prot); 1973 1974 /* ------------------------------------------------------------------------ */ 1975 #ifdef CONFIG_PROC_FS 1976 1977 static struct sock *udp_get_first(struct seq_file *seq, int start) 1978 { 1979 struct sock *sk; 1980 struct udp_iter_state *state = seq->private; 1981 struct net *net = seq_file_net(seq); 1982 1983 for (state->bucket = start; state->bucket <= state->udp_table->mask; 1984 ++state->bucket) { 1985 struct hlist_nulls_node *node; 1986 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; 1987 1988 if (hlist_nulls_empty(&hslot->head)) 1989 continue; 1990 1991 spin_lock_bh(&hslot->lock); 1992 sk_nulls_for_each(sk, node, &hslot->head) { 1993 if (!net_eq(sock_net(sk), net)) 1994 continue; 1995 if (sk->sk_family == state->family) 1996 goto found; 1997 } 1998 spin_unlock_bh(&hslot->lock); 1999 } 2000 sk = NULL; 2001 found: 2002 return sk; 2003 } 2004 2005 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 2006 { 2007 struct udp_iter_state *state = seq->private; 2008 struct net *net = seq_file_net(seq); 2009 2010 do { 2011 sk = sk_nulls_next(sk); 2012 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); 2013 2014 if (!sk) { 2015 if (state->bucket <= state->udp_table->mask) 2016 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2017 return udp_get_first(seq, state->bucket + 1); 2018 } 2019 return sk; 2020 } 2021 2022 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2023 { 2024 struct sock *sk = udp_get_first(seq, 0); 2025 2026 if (sk) 2027 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2028 --pos; 2029 return pos ? NULL : sk; 2030 } 2031 2032 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2033 { 2034 struct udp_iter_state *state = seq->private; 2035 state->bucket = MAX_UDP_PORTS; 2036 2037 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2038 } 2039 2040 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2041 { 2042 struct sock *sk; 2043 2044 if (v == SEQ_START_TOKEN) 2045 sk = udp_get_idx(seq, 0); 2046 else 2047 sk = udp_get_next(seq, v); 2048 2049 ++*pos; 2050 return sk; 2051 } 2052 2053 static void udp_seq_stop(struct seq_file *seq, void *v) 2054 { 2055 struct udp_iter_state *state = seq->private; 2056 2057 if (state->bucket <= state->udp_table->mask) 2058 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2059 } 2060 2061 int udp_seq_open(struct inode *inode, struct file *file) 2062 { 2063 struct udp_seq_afinfo *afinfo = PDE(inode)->data; 2064 struct udp_iter_state *s; 2065 int err; 2066 2067 err = seq_open_net(inode, file, &afinfo->seq_ops, 2068 sizeof(struct udp_iter_state)); 2069 if (err < 0) 2070 return err; 2071 2072 s = ((struct seq_file *)file->private_data)->private; 2073 s->family = afinfo->family; 2074 s->udp_table = afinfo->udp_table; 2075 return err; 2076 } 2077 EXPORT_SYMBOL(udp_seq_open); 2078 2079 /* ------------------------------------------------------------------------ */ 2080 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) 2081 { 2082 struct proc_dir_entry *p; 2083 int rc = 0; 2084 2085 afinfo->seq_ops.start = udp_seq_start; 2086 afinfo->seq_ops.next = udp_seq_next; 2087 afinfo->seq_ops.stop = udp_seq_stop; 2088 2089 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 2090 afinfo->seq_fops, afinfo); 2091 if (!p) 2092 rc = -ENOMEM; 2093 return rc; 2094 } 2095 EXPORT_SYMBOL(udp_proc_register); 2096 2097 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 2098 { 2099 proc_net_remove(net, afinfo->name); 2100 } 2101 EXPORT_SYMBOL(udp_proc_unregister); 2102 2103 /* ------------------------------------------------------------------------ */ 2104 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2105 int bucket, int *len) 2106 { 2107 struct inet_sock *inet = inet_sk(sp); 2108 __be32 dest = inet->inet_daddr; 2109 __be32 src = inet->inet_rcv_saddr; 2110 __u16 destp = ntohs(inet->inet_dport); 2111 __u16 srcp = ntohs(inet->inet_sport); 2112 2113 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2114 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n", 2115 bucket, src, srcp, dest, destp, sp->sk_state, 2116 sk_wmem_alloc_get(sp), 2117 sk_rmem_alloc_get(sp), 2118 0, 0L, 0, 2119 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 2120 0, sock_i_ino(sp), 2121 atomic_read(&sp->sk_refcnt), sp, 2122 atomic_read(&sp->sk_drops), len); 2123 } 2124 2125 int udp4_seq_show(struct seq_file *seq, void *v) 2126 { 2127 if (v == SEQ_START_TOKEN) 2128 seq_printf(seq, "%-127s\n", 2129 " sl local_address rem_address st tx_queue " 2130 "rx_queue tr tm->when retrnsmt uid timeout " 2131 "inode ref pointer drops"); 2132 else { 2133 struct udp_iter_state *state = seq->private; 2134 int len; 2135 2136 udp4_format_sock(v, seq, state->bucket, &len); 2137 seq_printf(seq, "%*s\n", 127 - len, ""); 2138 } 2139 return 0; 2140 } 2141 2142 static const struct file_operations udp_afinfo_seq_fops = { 2143 .owner = THIS_MODULE, 2144 .open = udp_seq_open, 2145 .read = seq_read, 2146 .llseek = seq_lseek, 2147 .release = seq_release_net 2148 }; 2149 2150 /* ------------------------------------------------------------------------ */ 2151 static struct udp_seq_afinfo udp4_seq_afinfo = { 2152 .name = "udp", 2153 .family = AF_INET, 2154 .udp_table = &udp_table, 2155 .seq_fops = &udp_afinfo_seq_fops, 2156 .seq_ops = { 2157 .show = udp4_seq_show, 2158 }, 2159 }; 2160 2161 static int __net_init udp4_proc_init_net(struct net *net) 2162 { 2163 return udp_proc_register(net, &udp4_seq_afinfo); 2164 } 2165 2166 static void __net_exit udp4_proc_exit_net(struct net *net) 2167 { 2168 udp_proc_unregister(net, &udp4_seq_afinfo); 2169 } 2170 2171 static struct pernet_operations udp4_net_ops = { 2172 .init = udp4_proc_init_net, 2173 .exit = udp4_proc_exit_net, 2174 }; 2175 2176 int __init udp4_proc_init(void) 2177 { 2178 return register_pernet_subsys(&udp4_net_ops); 2179 } 2180 2181 void udp4_proc_exit(void) 2182 { 2183 unregister_pernet_subsys(&udp4_net_ops); 2184 } 2185 #endif /* CONFIG_PROC_FS */ 2186 2187 static __initdata unsigned long uhash_entries; 2188 static int __init set_uhash_entries(char *str) 2189 { 2190 ssize_t ret; 2191 2192 if (!str) 2193 return 0; 2194 2195 ret = kstrtoul(str, 0, &uhash_entries); 2196 if (ret) 2197 return 0; 2198 2199 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2200 uhash_entries = UDP_HTABLE_SIZE_MIN; 2201 return 1; 2202 } 2203 __setup("uhash_entries=", set_uhash_entries); 2204 2205 void __init udp_table_init(struct udp_table *table, const char *name) 2206 { 2207 unsigned int i; 2208 2209 table->hash = alloc_large_system_hash(name, 2210 2 * sizeof(struct udp_hslot), 2211 uhash_entries, 2212 21, /* one slot per 2 MB */ 2213 0, 2214 &table->log, 2215 &table->mask, 2216 UDP_HTABLE_SIZE_MIN, 2217 64 * 1024); 2218 2219 table->hash2 = table->hash + (table->mask + 1); 2220 for (i = 0; i <= table->mask; i++) { 2221 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); 2222 table->hash[i].count = 0; 2223 spin_lock_init(&table->hash[i].lock); 2224 } 2225 for (i = 0; i <= table->mask; i++) { 2226 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); 2227 table->hash2[i].count = 0; 2228 spin_lock_init(&table->hash2[i].lock); 2229 } 2230 } 2231 2232 void __init udp_init(void) 2233 { 2234 unsigned long limit; 2235 2236 udp_table_init(&udp_table, "UDP"); 2237 limit = nr_free_buffer_pages() / 8; 2238 limit = max(limit, 128UL); 2239 sysctl_udp_mem[0] = limit / 4 * 3; 2240 sysctl_udp_mem[1] = limit; 2241 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 2242 2243 sysctl_udp_rmem_min = SK_MEM_QUANTUM; 2244 sysctl_udp_wmem_min = SK_MEM_QUANTUM; 2245 } 2246 2247 int udp4_ufo_send_check(struct sk_buff *skb) 2248 { 2249 const struct iphdr *iph; 2250 struct udphdr *uh; 2251 2252 if (!pskb_may_pull(skb, sizeof(*uh))) 2253 return -EINVAL; 2254 2255 iph = ip_hdr(skb); 2256 uh = udp_hdr(skb); 2257 2258 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 2259 IPPROTO_UDP, 0); 2260 skb->csum_start = skb_transport_header(skb) - skb->head; 2261 skb->csum_offset = offsetof(struct udphdr, check); 2262 skb->ip_summed = CHECKSUM_PARTIAL; 2263 return 0; 2264 } 2265 2266 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 2267 netdev_features_t features) 2268 { 2269 struct sk_buff *segs = ERR_PTR(-EINVAL); 2270 unsigned int mss; 2271 int offset; 2272 __wsum csum; 2273 2274 mss = skb_shinfo(skb)->gso_size; 2275 if (unlikely(skb->len <= mss)) 2276 goto out; 2277 2278 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2279 /* Packet is from an untrusted source, reset gso_segs. */ 2280 int type = skb_shinfo(skb)->gso_type; 2281 2282 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) || 2283 !(type & (SKB_GSO_UDP)))) 2284 goto out; 2285 2286 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2287 2288 segs = NULL; 2289 goto out; 2290 } 2291 2292 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot 2293 * do checksum of UDP packets sent as multiple IP fragments. 2294 */ 2295 offset = skb_checksum_start_offset(skb); 2296 csum = skb_checksum(skb, offset, skb->len - offset, 0); 2297 offset += skb->csum_offset; 2298 *(__sum16 *)(skb->data + offset) = csum_fold(csum); 2299 skb->ip_summed = CHECKSUM_NONE; 2300 2301 /* Fragment the skb. IP headers of the fragments are updated in 2302 * inet_gso_segment() 2303 */ 2304 segs = skb_segment(skb, features); 2305 out: 2306 return segs; 2307 } 2308 2309