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 #include <asm/system.h> 81 #include <asm/uaccess.h> 82 #include <asm/ioctls.h> 83 #include <linux/bootmem.h> 84 #include <linux/highmem.h> 85 #include <linux/swap.h> 86 #include <linux/types.h> 87 #include <linux/fcntl.h> 88 #include <linux/module.h> 89 #include <linux/socket.h> 90 #include <linux/sockios.h> 91 #include <linux/igmp.h> 92 #include <linux/in.h> 93 #include <linux/errno.h> 94 #include <linux/timer.h> 95 #include <linux/mm.h> 96 #include <linux/inet.h> 97 #include <linux/netdevice.h> 98 #include <linux/slab.h> 99 #include <net/tcp_states.h> 100 #include <linux/skbuff.h> 101 #include <linux/proc_fs.h> 102 #include <linux/seq_file.h> 103 #include <net/net_namespace.h> 104 #include <net/icmp.h> 105 #include <net/route.h> 106 #include <net/checksum.h> 107 #include <net/xfrm.h> 108 #include <trace/events/udp.h> 109 #include "udp_impl.h" 110 111 struct udp_table udp_table __read_mostly; 112 EXPORT_SYMBOL(udp_table); 113 114 long sysctl_udp_mem[3] __read_mostly; 115 EXPORT_SYMBOL(sysctl_udp_mem); 116 117 int sysctl_udp_rmem_min __read_mostly; 118 EXPORT_SYMBOL(sysctl_udp_rmem_min); 119 120 int sysctl_udp_wmem_min __read_mostly; 121 EXPORT_SYMBOL(sysctl_udp_wmem_min); 122 123 atomic_long_t udp_memory_allocated; 124 EXPORT_SYMBOL(udp_memory_allocated); 125 126 #define MAX_UDP_PORTS 65536 127 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 128 129 static int udp_lib_lport_inuse(struct net *net, __u16 num, 130 const struct udp_hslot *hslot, 131 unsigned long *bitmap, 132 struct sock *sk, 133 int (*saddr_comp)(const struct sock *sk1, 134 const struct sock *sk2), 135 unsigned int log) 136 { 137 struct sock *sk2; 138 struct hlist_nulls_node *node; 139 140 sk_nulls_for_each(sk2, node, &hslot->head) 141 if (net_eq(sock_net(sk2), net) && 142 sk2 != sk && 143 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 144 (!sk2->sk_reuse || !sk->sk_reuse) && 145 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 146 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 147 (*saddr_comp)(sk, sk2)) { 148 if (bitmap) 149 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 150 bitmap); 151 else 152 return 1; 153 } 154 return 0; 155 } 156 157 /* 158 * Note: we still hold spinlock of primary hash chain, so no other writer 159 * can insert/delete a socket with local_port == num 160 */ 161 static int udp_lib_lport_inuse2(struct net *net, __u16 num, 162 struct udp_hslot *hslot2, 163 struct sock *sk, 164 int (*saddr_comp)(const struct sock *sk1, 165 const struct sock *sk2)) 166 { 167 struct sock *sk2; 168 struct hlist_nulls_node *node; 169 int res = 0; 170 171 spin_lock(&hslot2->lock); 172 udp_portaddr_for_each_entry(sk2, node, &hslot2->head) 173 if (net_eq(sock_net(sk2), net) && 174 sk2 != sk && 175 (udp_sk(sk2)->udp_port_hash == num) && 176 (!sk2->sk_reuse || !sk->sk_reuse) && 177 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 178 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 179 (*saddr_comp)(sk, sk2)) { 180 res = 1; 181 break; 182 } 183 spin_unlock(&hslot2->lock); 184 return res; 185 } 186 187 /** 188 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 189 * 190 * @sk: socket struct in question 191 * @snum: port number to look up 192 * @saddr_comp: AF-dependent comparison of bound local IP addresses 193 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 194 * with NULL address 195 */ 196 int udp_lib_get_port(struct sock *sk, unsigned short snum, 197 int (*saddr_comp)(const struct sock *sk1, 198 const struct sock *sk2), 199 unsigned int hash2_nulladdr) 200 { 201 struct udp_hslot *hslot, *hslot2; 202 struct udp_table *udptable = sk->sk_prot->h.udp_table; 203 int error = 1; 204 struct net *net = sock_net(sk); 205 206 if (!snum) { 207 int low, high, remaining; 208 unsigned rand; 209 unsigned short first, last; 210 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 211 212 inet_get_local_port_range(&low, &high); 213 remaining = (high - low) + 1; 214 215 rand = net_random(); 216 first = (((u64)rand * remaining) >> 32) + low; 217 /* 218 * force rand to be an odd multiple of UDP_HTABLE_SIZE 219 */ 220 rand = (rand | 1) * (udptable->mask + 1); 221 last = first + udptable->mask + 1; 222 do { 223 hslot = udp_hashslot(udptable, net, first); 224 bitmap_zero(bitmap, PORTS_PER_CHAIN); 225 spin_lock_bh(&hslot->lock); 226 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 227 saddr_comp, udptable->log); 228 229 snum = first; 230 /* 231 * Iterate on all possible values of snum for this hash. 232 * Using steps of an odd multiple of UDP_HTABLE_SIZE 233 * give us randomization and full range coverage. 234 */ 235 do { 236 if (low <= snum && snum <= high && 237 !test_bit(snum >> udptable->log, bitmap) && 238 !inet_is_reserved_local_port(snum)) 239 goto found; 240 snum += rand; 241 } while (snum != first); 242 spin_unlock_bh(&hslot->lock); 243 } while (++first != last); 244 goto fail; 245 } else { 246 hslot = udp_hashslot(udptable, net, snum); 247 spin_lock_bh(&hslot->lock); 248 if (hslot->count > 10) { 249 int exist; 250 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 251 252 slot2 &= udptable->mask; 253 hash2_nulladdr &= udptable->mask; 254 255 hslot2 = udp_hashslot2(udptable, slot2); 256 if (hslot->count < hslot2->count) 257 goto scan_primary_hash; 258 259 exist = udp_lib_lport_inuse2(net, snum, hslot2, 260 sk, saddr_comp); 261 if (!exist && (hash2_nulladdr != slot2)) { 262 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 263 exist = udp_lib_lport_inuse2(net, snum, hslot2, 264 sk, saddr_comp); 265 } 266 if (exist) 267 goto fail_unlock; 268 else 269 goto found; 270 } 271 scan_primary_hash: 272 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 273 saddr_comp, 0)) 274 goto fail_unlock; 275 } 276 found: 277 inet_sk(sk)->inet_num = snum; 278 udp_sk(sk)->udp_port_hash = snum; 279 udp_sk(sk)->udp_portaddr_hash ^= snum; 280 if (sk_unhashed(sk)) { 281 sk_nulls_add_node_rcu(sk, &hslot->head); 282 hslot->count++; 283 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 284 285 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 286 spin_lock(&hslot2->lock); 287 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 288 &hslot2->head); 289 hslot2->count++; 290 spin_unlock(&hslot2->lock); 291 } 292 error = 0; 293 fail_unlock: 294 spin_unlock_bh(&hslot->lock); 295 fail: 296 return error; 297 } 298 EXPORT_SYMBOL(udp_lib_get_port); 299 300 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 301 { 302 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 303 304 return (!ipv6_only_sock(sk2) && 305 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr || 306 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr)); 307 } 308 309 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr, 310 unsigned int port) 311 { 312 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 313 } 314 315 int udp_v4_get_port(struct sock *sk, unsigned short snum) 316 { 317 unsigned int hash2_nulladdr = 318 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 319 unsigned int hash2_partial = 320 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 321 322 /* precompute partial secondary hash */ 323 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 324 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr); 325 } 326 327 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr, 328 unsigned short hnum, 329 __be16 sport, __be32 daddr, __be16 dport, int dif) 330 { 331 int score = -1; 332 333 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && 334 !ipv6_only_sock(sk)) { 335 struct inet_sock *inet = inet_sk(sk); 336 337 score = (sk->sk_family == PF_INET ? 1 : 0); 338 if (inet->inet_rcv_saddr) { 339 if (inet->inet_rcv_saddr != daddr) 340 return -1; 341 score += 2; 342 } 343 if (inet->inet_daddr) { 344 if (inet->inet_daddr != saddr) 345 return -1; 346 score += 2; 347 } 348 if (inet->inet_dport) { 349 if (inet->inet_dport != sport) 350 return -1; 351 score += 2; 352 } 353 if (sk->sk_bound_dev_if) { 354 if (sk->sk_bound_dev_if != dif) 355 return -1; 356 score += 2; 357 } 358 } 359 return score; 360 } 361 362 /* 363 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num) 364 */ 365 #define SCORE2_MAX (1 + 2 + 2 + 2) 366 static inline int compute_score2(struct sock *sk, struct net *net, 367 __be32 saddr, __be16 sport, 368 __be32 daddr, unsigned int hnum, int dif) 369 { 370 int score = -1; 371 372 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) { 373 struct inet_sock *inet = inet_sk(sk); 374 375 if (inet->inet_rcv_saddr != daddr) 376 return -1; 377 if (inet->inet_num != hnum) 378 return -1; 379 380 score = (sk->sk_family == PF_INET ? 1 : 0); 381 if (inet->inet_daddr) { 382 if (inet->inet_daddr != saddr) 383 return -1; 384 score += 2; 385 } 386 if (inet->inet_dport) { 387 if (inet->inet_dport != sport) 388 return -1; 389 score += 2; 390 } 391 if (sk->sk_bound_dev_if) { 392 if (sk->sk_bound_dev_if != dif) 393 return -1; 394 score += 2; 395 } 396 } 397 return score; 398 } 399 400 401 /* called with read_rcu_lock() */ 402 static struct sock *udp4_lib_lookup2(struct net *net, 403 __be32 saddr, __be16 sport, 404 __be32 daddr, unsigned int hnum, int dif, 405 struct udp_hslot *hslot2, unsigned int slot2) 406 { 407 struct sock *sk, *result; 408 struct hlist_nulls_node *node; 409 int score, badness; 410 411 begin: 412 result = NULL; 413 badness = -1; 414 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { 415 score = compute_score2(sk, net, saddr, sport, 416 daddr, hnum, dif); 417 if (score > badness) { 418 result = sk; 419 badness = score; 420 if (score == SCORE2_MAX) 421 goto exact_match; 422 } 423 } 424 /* 425 * if the nulls value we got at the end of this lookup is 426 * not the expected one, we must restart lookup. 427 * We probably met an item that was moved to another chain. 428 */ 429 if (get_nulls_value(node) != slot2) 430 goto begin; 431 432 if (result) { 433 exact_match: 434 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 435 result = NULL; 436 else if (unlikely(compute_score2(result, net, saddr, sport, 437 daddr, hnum, dif) < badness)) { 438 sock_put(result); 439 goto begin; 440 } 441 } 442 return result; 443 } 444 445 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 446 * harder than this. -DaveM 447 */ 448 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 449 __be16 sport, __be32 daddr, __be16 dport, 450 int dif, struct udp_table *udptable) 451 { 452 struct sock *sk, *result; 453 struct hlist_nulls_node *node; 454 unsigned short hnum = ntohs(dport); 455 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); 456 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; 457 int score, badness; 458 459 rcu_read_lock(); 460 if (hslot->count > 10) { 461 hash2 = udp4_portaddr_hash(net, daddr, hnum); 462 slot2 = hash2 & udptable->mask; 463 hslot2 = &udptable->hash2[slot2]; 464 if (hslot->count < hslot2->count) 465 goto begin; 466 467 result = udp4_lib_lookup2(net, saddr, sport, 468 daddr, hnum, dif, 469 hslot2, slot2); 470 if (!result) { 471 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 472 slot2 = hash2 & udptable->mask; 473 hslot2 = &udptable->hash2[slot2]; 474 if (hslot->count < hslot2->count) 475 goto begin; 476 477 result = udp4_lib_lookup2(net, saddr, sport, 478 htonl(INADDR_ANY), hnum, dif, 479 hslot2, slot2); 480 } 481 rcu_read_unlock(); 482 return result; 483 } 484 begin: 485 result = NULL; 486 badness = -1; 487 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 488 score = compute_score(sk, net, saddr, hnum, sport, 489 daddr, dport, dif); 490 if (score > badness) { 491 result = sk; 492 badness = score; 493 } 494 } 495 /* 496 * if the nulls value we got at the end of this lookup is 497 * not the expected one, we must restart lookup. 498 * We probably met an item that was moved to another chain. 499 */ 500 if (get_nulls_value(node) != slot) 501 goto begin; 502 503 if (result) { 504 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 505 result = NULL; 506 else if (unlikely(compute_score(result, net, saddr, hnum, sport, 507 daddr, dport, dif) < badness)) { 508 sock_put(result); 509 goto begin; 510 } 511 } 512 rcu_read_unlock(); 513 return result; 514 } 515 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 516 517 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 518 __be16 sport, __be16 dport, 519 struct udp_table *udptable) 520 { 521 struct sock *sk; 522 const struct iphdr *iph = ip_hdr(skb); 523 524 if (unlikely(sk = skb_steal_sock(skb))) 525 return sk; 526 else 527 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, 528 iph->daddr, dport, inet_iif(skb), 529 udptable); 530 } 531 532 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 533 __be32 daddr, __be16 dport, int dif) 534 { 535 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); 536 } 537 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 538 539 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk, 540 __be16 loc_port, __be32 loc_addr, 541 __be16 rmt_port, __be32 rmt_addr, 542 int dif) 543 { 544 struct hlist_nulls_node *node; 545 struct sock *s = sk; 546 unsigned short hnum = ntohs(loc_port); 547 548 sk_nulls_for_each_from(s, node) { 549 struct inet_sock *inet = inet_sk(s); 550 551 if (!net_eq(sock_net(s), net) || 552 udp_sk(s)->udp_port_hash != hnum || 553 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 554 (inet->inet_dport != rmt_port && inet->inet_dport) || 555 (inet->inet_rcv_saddr && 556 inet->inet_rcv_saddr != loc_addr) || 557 ipv6_only_sock(s) || 558 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) 559 continue; 560 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) 561 continue; 562 goto found; 563 } 564 s = NULL; 565 found: 566 return s; 567 } 568 569 /* 570 * This routine is called by the ICMP module when it gets some 571 * sort of error condition. If err < 0 then the socket should 572 * be closed and the error returned to the user. If err > 0 573 * it's just the icmp type << 8 | icmp code. 574 * Header points to the ip header of the error packet. We move 575 * on past this. Then (as it used to claim before adjustment) 576 * header points to the first 8 bytes of the udp header. We need 577 * to find the appropriate port. 578 */ 579 580 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 581 { 582 struct inet_sock *inet; 583 const struct iphdr *iph = (const struct iphdr *)skb->data; 584 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 585 const int type = icmp_hdr(skb)->type; 586 const int code = icmp_hdr(skb)->code; 587 struct sock *sk; 588 int harderr; 589 int err; 590 struct net *net = dev_net(skb->dev); 591 592 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 593 iph->saddr, uh->source, skb->dev->ifindex, udptable); 594 if (sk == NULL) { 595 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 596 return; /* No socket for error */ 597 } 598 599 err = 0; 600 harderr = 0; 601 inet = inet_sk(sk); 602 603 switch (type) { 604 default: 605 case ICMP_TIME_EXCEEDED: 606 err = EHOSTUNREACH; 607 break; 608 case ICMP_SOURCE_QUENCH: 609 goto out; 610 case ICMP_PARAMETERPROB: 611 err = EPROTO; 612 harderr = 1; 613 break; 614 case ICMP_DEST_UNREACH: 615 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 616 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 617 err = EMSGSIZE; 618 harderr = 1; 619 break; 620 } 621 goto out; 622 } 623 err = EHOSTUNREACH; 624 if (code <= NR_ICMP_UNREACH) { 625 harderr = icmp_err_convert[code].fatal; 626 err = icmp_err_convert[code].errno; 627 } 628 break; 629 } 630 631 /* 632 * RFC1122: OK. Passes ICMP errors back to application, as per 633 * 4.1.3.3. 634 */ 635 if (!inet->recverr) { 636 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 637 goto out; 638 } else 639 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 640 641 sk->sk_err = err; 642 sk->sk_error_report(sk); 643 out: 644 sock_put(sk); 645 } 646 647 void udp_err(struct sk_buff *skb, u32 info) 648 { 649 __udp4_lib_err(skb, info, &udp_table); 650 } 651 652 /* 653 * Throw away all pending data and cancel the corking. Socket is locked. 654 */ 655 void udp_flush_pending_frames(struct sock *sk) 656 { 657 struct udp_sock *up = udp_sk(sk); 658 659 if (up->pending) { 660 up->len = 0; 661 up->pending = 0; 662 ip_flush_pending_frames(sk); 663 } 664 } 665 EXPORT_SYMBOL(udp_flush_pending_frames); 666 667 /** 668 * udp4_hwcsum - handle outgoing HW checksumming 669 * @skb: sk_buff containing the filled-in UDP header 670 * (checksum field must be zeroed out) 671 * @src: source IP address 672 * @dst: destination IP address 673 */ 674 static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 675 { 676 struct udphdr *uh = udp_hdr(skb); 677 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 678 int offset = skb_transport_offset(skb); 679 int len = skb->len - offset; 680 int hlen = len; 681 __wsum csum = 0; 682 683 if (!frags) { 684 /* 685 * Only one fragment on the socket. 686 */ 687 skb->csum_start = skb_transport_header(skb) - skb->head; 688 skb->csum_offset = offsetof(struct udphdr, check); 689 uh->check = ~csum_tcpudp_magic(src, dst, len, 690 IPPROTO_UDP, 0); 691 } else { 692 /* 693 * HW-checksum won't work as there are two or more 694 * fragments on the socket so that all csums of sk_buffs 695 * should be together 696 */ 697 do { 698 csum = csum_add(csum, frags->csum); 699 hlen -= frags->len; 700 } while ((frags = frags->next)); 701 702 csum = skb_checksum(skb, offset, hlen, csum); 703 skb->ip_summed = CHECKSUM_NONE; 704 705 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 706 if (uh->check == 0) 707 uh->check = CSUM_MANGLED_0; 708 } 709 } 710 711 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) 712 { 713 struct sock *sk = skb->sk; 714 struct inet_sock *inet = inet_sk(sk); 715 struct udphdr *uh; 716 int err = 0; 717 int is_udplite = IS_UDPLITE(sk); 718 int offset = skb_transport_offset(skb); 719 int len = skb->len - offset; 720 __wsum csum = 0; 721 722 /* 723 * Create a UDP header 724 */ 725 uh = udp_hdr(skb); 726 uh->source = inet->inet_sport; 727 uh->dest = fl4->fl4_dport; 728 uh->len = htons(len); 729 uh->check = 0; 730 731 if (is_udplite) /* UDP-Lite */ 732 csum = udplite_csum(skb); 733 734 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ 735 736 skb->ip_summed = CHECKSUM_NONE; 737 goto send; 738 739 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 740 741 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 742 goto send; 743 744 } else 745 csum = udp_csum(skb); 746 747 /* add protocol-dependent pseudo-header */ 748 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 749 sk->sk_protocol, csum); 750 if (uh->check == 0) 751 uh->check = CSUM_MANGLED_0; 752 753 send: 754 err = ip_send_skb(skb); 755 if (err) { 756 if (err == -ENOBUFS && !inet->recverr) { 757 UDP_INC_STATS_USER(sock_net(sk), 758 UDP_MIB_SNDBUFERRORS, is_udplite); 759 err = 0; 760 } 761 } else 762 UDP_INC_STATS_USER(sock_net(sk), 763 UDP_MIB_OUTDATAGRAMS, is_udplite); 764 return err; 765 } 766 767 /* 768 * Push out all pending data as one UDP datagram. Socket is locked. 769 */ 770 static int udp_push_pending_frames(struct sock *sk) 771 { 772 struct udp_sock *up = udp_sk(sk); 773 struct inet_sock *inet = inet_sk(sk); 774 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 775 struct sk_buff *skb; 776 int err = 0; 777 778 skb = ip_finish_skb(sk, fl4); 779 if (!skb) 780 goto out; 781 782 err = udp_send_skb(skb, fl4); 783 784 out: 785 up->len = 0; 786 up->pending = 0; 787 return err; 788 } 789 790 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 791 size_t len) 792 { 793 struct inet_sock *inet = inet_sk(sk); 794 struct udp_sock *up = udp_sk(sk); 795 struct flowi4 fl4_stack; 796 struct flowi4 *fl4; 797 int ulen = len; 798 struct ipcm_cookie ipc; 799 struct rtable *rt = NULL; 800 int free = 0; 801 int connected = 0; 802 __be32 daddr, faddr, saddr; 803 __be16 dport; 804 u8 tos; 805 int err, is_udplite = IS_UDPLITE(sk); 806 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 807 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 808 struct sk_buff *skb; 809 struct ip_options_data opt_copy; 810 811 if (len > 0xFFFF) 812 return -EMSGSIZE; 813 814 /* 815 * Check the flags. 816 */ 817 818 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 819 return -EOPNOTSUPP; 820 821 ipc.opt = NULL; 822 ipc.tx_flags = 0; 823 824 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 825 826 fl4 = &inet->cork.fl.u.ip4; 827 if (up->pending) { 828 /* 829 * There are pending frames. 830 * The socket lock must be held while it's corked. 831 */ 832 lock_sock(sk); 833 if (likely(up->pending)) { 834 if (unlikely(up->pending != AF_INET)) { 835 release_sock(sk); 836 return -EINVAL; 837 } 838 goto do_append_data; 839 } 840 release_sock(sk); 841 } 842 ulen += sizeof(struct udphdr); 843 844 /* 845 * Get and verify the address. 846 */ 847 if (msg->msg_name) { 848 struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name; 849 if (msg->msg_namelen < sizeof(*usin)) 850 return -EINVAL; 851 if (usin->sin_family != AF_INET) { 852 if (usin->sin_family != AF_UNSPEC) 853 return -EAFNOSUPPORT; 854 } 855 856 daddr = usin->sin_addr.s_addr; 857 dport = usin->sin_port; 858 if (dport == 0) 859 return -EINVAL; 860 } else { 861 if (sk->sk_state != TCP_ESTABLISHED) 862 return -EDESTADDRREQ; 863 daddr = inet->inet_daddr; 864 dport = inet->inet_dport; 865 /* Open fast path for connected socket. 866 Route will not be used, if at least one option is set. 867 */ 868 connected = 1; 869 } 870 ipc.addr = inet->inet_saddr; 871 872 ipc.oif = sk->sk_bound_dev_if; 873 err = sock_tx_timestamp(sk, &ipc.tx_flags); 874 if (err) 875 return err; 876 if (msg->msg_controllen) { 877 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 878 if (err) 879 return err; 880 if (ipc.opt) 881 free = 1; 882 connected = 0; 883 } 884 if (!ipc.opt) { 885 struct ip_options_rcu *inet_opt; 886 887 rcu_read_lock(); 888 inet_opt = rcu_dereference(inet->inet_opt); 889 if (inet_opt) { 890 memcpy(&opt_copy, inet_opt, 891 sizeof(*inet_opt) + inet_opt->opt.optlen); 892 ipc.opt = &opt_copy.opt; 893 } 894 rcu_read_unlock(); 895 } 896 897 saddr = ipc.addr; 898 ipc.addr = faddr = daddr; 899 900 if (ipc.opt && ipc.opt->opt.srr) { 901 if (!daddr) 902 return -EINVAL; 903 faddr = ipc.opt->opt.faddr; 904 connected = 0; 905 } 906 tos = RT_TOS(inet->tos); 907 if (sock_flag(sk, SOCK_LOCALROUTE) || 908 (msg->msg_flags & MSG_DONTROUTE) || 909 (ipc.opt && ipc.opt->opt.is_strictroute)) { 910 tos |= RTO_ONLINK; 911 connected = 0; 912 } 913 914 if (ipv4_is_multicast(daddr)) { 915 if (!ipc.oif) 916 ipc.oif = inet->mc_index; 917 if (!saddr) 918 saddr = inet->mc_addr; 919 connected = 0; 920 } 921 922 if (connected) 923 rt = (struct rtable *)sk_dst_check(sk, 0); 924 925 if (rt == NULL) { 926 struct net *net = sock_net(sk); 927 928 fl4 = &fl4_stack; 929 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, 930 RT_SCOPE_UNIVERSE, sk->sk_protocol, 931 inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP, 932 faddr, saddr, dport, inet->inet_sport); 933 934 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 935 rt = ip_route_output_flow(net, fl4, sk); 936 if (IS_ERR(rt)) { 937 err = PTR_ERR(rt); 938 rt = NULL; 939 if (err == -ENETUNREACH) 940 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 941 goto out; 942 } 943 944 err = -EACCES; 945 if ((rt->rt_flags & RTCF_BROADCAST) && 946 !sock_flag(sk, SOCK_BROADCAST)) 947 goto out; 948 if (connected) 949 sk_dst_set(sk, dst_clone(&rt->dst)); 950 } 951 952 if (msg->msg_flags&MSG_CONFIRM) 953 goto do_confirm; 954 back_from_confirm: 955 956 saddr = fl4->saddr; 957 if (!ipc.addr) 958 daddr = ipc.addr = fl4->daddr; 959 960 /* Lockless fast path for the non-corking case. */ 961 if (!corkreq) { 962 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen, 963 sizeof(struct udphdr), &ipc, &rt, 964 msg->msg_flags); 965 err = PTR_ERR(skb); 966 if (skb && !IS_ERR(skb)) 967 err = udp_send_skb(skb, fl4); 968 goto out; 969 } 970 971 lock_sock(sk); 972 if (unlikely(up->pending)) { 973 /* The socket is already corked while preparing it. */ 974 /* ... which is an evident application bug. --ANK */ 975 release_sock(sk); 976 977 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n"); 978 err = -EINVAL; 979 goto out; 980 } 981 /* 982 * Now cork the socket to pend data. 983 */ 984 fl4 = &inet->cork.fl.u.ip4; 985 fl4->daddr = daddr; 986 fl4->saddr = saddr; 987 fl4->fl4_dport = dport; 988 fl4->fl4_sport = inet->inet_sport; 989 up->pending = AF_INET; 990 991 do_append_data: 992 up->len += ulen; 993 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen, 994 sizeof(struct udphdr), &ipc, &rt, 995 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 996 if (err) 997 udp_flush_pending_frames(sk); 998 else if (!corkreq) 999 err = udp_push_pending_frames(sk); 1000 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1001 up->pending = 0; 1002 release_sock(sk); 1003 1004 out: 1005 ip_rt_put(rt); 1006 if (free) 1007 kfree(ipc.opt); 1008 if (!err) 1009 return len; 1010 /* 1011 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1012 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1013 * we don't have a good statistic (IpOutDiscards but it can be too many 1014 * things). We could add another new stat but at least for now that 1015 * seems like overkill. 1016 */ 1017 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1018 UDP_INC_STATS_USER(sock_net(sk), 1019 UDP_MIB_SNDBUFERRORS, is_udplite); 1020 } 1021 return err; 1022 1023 do_confirm: 1024 dst_confirm(&rt->dst); 1025 if (!(msg->msg_flags&MSG_PROBE) || len) 1026 goto back_from_confirm; 1027 err = 0; 1028 goto out; 1029 } 1030 EXPORT_SYMBOL(udp_sendmsg); 1031 1032 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1033 size_t size, int flags) 1034 { 1035 struct inet_sock *inet = inet_sk(sk); 1036 struct udp_sock *up = udp_sk(sk); 1037 int ret; 1038 1039 if (!up->pending) { 1040 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1041 1042 /* Call udp_sendmsg to specify destination address which 1043 * sendpage interface can't pass. 1044 * This will succeed only when the socket is connected. 1045 */ 1046 ret = udp_sendmsg(NULL, sk, &msg, 0); 1047 if (ret < 0) 1048 return ret; 1049 } 1050 1051 lock_sock(sk); 1052 1053 if (unlikely(!up->pending)) { 1054 release_sock(sk); 1055 1056 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n"); 1057 return -EINVAL; 1058 } 1059 1060 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1061 page, offset, size, flags); 1062 if (ret == -EOPNOTSUPP) { 1063 release_sock(sk); 1064 return sock_no_sendpage(sk->sk_socket, page, offset, 1065 size, flags); 1066 } 1067 if (ret < 0) { 1068 udp_flush_pending_frames(sk); 1069 goto out; 1070 } 1071 1072 up->len += size; 1073 if (!(up->corkflag || (flags&MSG_MORE))) 1074 ret = udp_push_pending_frames(sk); 1075 if (!ret) 1076 ret = size; 1077 out: 1078 release_sock(sk); 1079 return ret; 1080 } 1081 1082 1083 /** 1084 * first_packet_length - return length of first packet in receive queue 1085 * @sk: socket 1086 * 1087 * Drops all bad checksum frames, until a valid one is found. 1088 * Returns the length of found skb, or 0 if none is found. 1089 */ 1090 static unsigned int first_packet_length(struct sock *sk) 1091 { 1092 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue; 1093 struct sk_buff *skb; 1094 unsigned int res; 1095 1096 __skb_queue_head_init(&list_kill); 1097 1098 spin_lock_bh(&rcvq->lock); 1099 while ((skb = skb_peek(rcvq)) != NULL && 1100 udp_lib_checksum_complete(skb)) { 1101 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1102 IS_UDPLITE(sk)); 1103 atomic_inc(&sk->sk_drops); 1104 __skb_unlink(skb, rcvq); 1105 __skb_queue_tail(&list_kill, skb); 1106 } 1107 res = skb ? skb->len : 0; 1108 spin_unlock_bh(&rcvq->lock); 1109 1110 if (!skb_queue_empty(&list_kill)) { 1111 bool slow = lock_sock_fast(sk); 1112 1113 __skb_queue_purge(&list_kill); 1114 sk_mem_reclaim_partial(sk); 1115 unlock_sock_fast(sk, slow); 1116 } 1117 return res; 1118 } 1119 1120 /* 1121 * IOCTL requests applicable to the UDP protocol 1122 */ 1123 1124 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1125 { 1126 switch (cmd) { 1127 case SIOCOUTQ: 1128 { 1129 int amount = sk_wmem_alloc_get(sk); 1130 1131 return put_user(amount, (int __user *)arg); 1132 } 1133 1134 case SIOCINQ: 1135 { 1136 unsigned int amount = first_packet_length(sk); 1137 1138 if (amount) 1139 /* 1140 * We will only return the amount 1141 * of this packet since that is all 1142 * that will be read. 1143 */ 1144 amount -= sizeof(struct udphdr); 1145 1146 return put_user(amount, (int __user *)arg); 1147 } 1148 1149 default: 1150 return -ENOIOCTLCMD; 1151 } 1152 1153 return 0; 1154 } 1155 EXPORT_SYMBOL(udp_ioctl); 1156 1157 /* 1158 * This should be easy, if there is something there we 1159 * return it, otherwise we block. 1160 */ 1161 1162 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1163 size_t len, int noblock, int flags, int *addr_len) 1164 { 1165 struct inet_sock *inet = inet_sk(sk); 1166 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 1167 struct sk_buff *skb; 1168 unsigned int ulen, copied; 1169 int peeked; 1170 int err; 1171 int is_udplite = IS_UDPLITE(sk); 1172 bool slow; 1173 1174 /* 1175 * Check any passed addresses 1176 */ 1177 if (addr_len) 1178 *addr_len = sizeof(*sin); 1179 1180 if (flags & MSG_ERRQUEUE) 1181 return ip_recv_error(sk, msg, len); 1182 1183 try_again: 1184 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), 1185 &peeked, &err); 1186 if (!skb) 1187 goto out; 1188 1189 ulen = skb->len - sizeof(struct udphdr); 1190 copied = len; 1191 if (copied > ulen) 1192 copied = ulen; 1193 else if (copied < ulen) 1194 msg->msg_flags |= MSG_TRUNC; 1195 1196 /* 1197 * If checksum is needed at all, try to do it while copying the 1198 * data. If the data is truncated, or if we only want a partial 1199 * coverage checksum (UDP-Lite), do it before the copy. 1200 */ 1201 1202 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { 1203 if (udp_lib_checksum_complete(skb)) 1204 goto csum_copy_err; 1205 } 1206 1207 if (skb_csum_unnecessary(skb)) 1208 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), 1209 msg->msg_iov, copied); 1210 else { 1211 err = skb_copy_and_csum_datagram_iovec(skb, 1212 sizeof(struct udphdr), 1213 msg->msg_iov); 1214 1215 if (err == -EINVAL) 1216 goto csum_copy_err; 1217 } 1218 1219 if (err) 1220 goto out_free; 1221 1222 if (!peeked) 1223 UDP_INC_STATS_USER(sock_net(sk), 1224 UDP_MIB_INDATAGRAMS, is_udplite); 1225 1226 sock_recv_ts_and_drops(msg, sk, skb); 1227 1228 /* Copy the address. */ 1229 if (sin) { 1230 sin->sin_family = AF_INET; 1231 sin->sin_port = udp_hdr(skb)->source; 1232 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1233 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1234 } 1235 if (inet->cmsg_flags) 1236 ip_cmsg_recv(msg, skb); 1237 1238 err = copied; 1239 if (flags & MSG_TRUNC) 1240 err = ulen; 1241 1242 out_free: 1243 skb_free_datagram_locked(sk, skb); 1244 out: 1245 return err; 1246 1247 csum_copy_err: 1248 slow = lock_sock_fast(sk); 1249 if (!skb_kill_datagram(sk, skb, flags)) 1250 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1251 unlock_sock_fast(sk, slow); 1252 1253 if (noblock) 1254 return -EAGAIN; 1255 1256 /* starting over for a new packet */ 1257 msg->msg_flags &= ~MSG_TRUNC; 1258 goto try_again; 1259 } 1260 1261 1262 int udp_disconnect(struct sock *sk, int flags) 1263 { 1264 struct inet_sock *inet = inet_sk(sk); 1265 /* 1266 * 1003.1g - break association. 1267 */ 1268 1269 sk->sk_state = TCP_CLOSE; 1270 inet->inet_daddr = 0; 1271 inet->inet_dport = 0; 1272 sock_rps_reset_rxhash(sk); 1273 sk->sk_bound_dev_if = 0; 1274 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1275 inet_reset_saddr(sk); 1276 1277 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1278 sk->sk_prot->unhash(sk); 1279 inet->inet_sport = 0; 1280 } 1281 sk_dst_reset(sk); 1282 return 0; 1283 } 1284 EXPORT_SYMBOL(udp_disconnect); 1285 1286 void udp_lib_unhash(struct sock *sk) 1287 { 1288 if (sk_hashed(sk)) { 1289 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1290 struct udp_hslot *hslot, *hslot2; 1291 1292 hslot = udp_hashslot(udptable, sock_net(sk), 1293 udp_sk(sk)->udp_port_hash); 1294 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1295 1296 spin_lock_bh(&hslot->lock); 1297 if (sk_nulls_del_node_init_rcu(sk)) { 1298 hslot->count--; 1299 inet_sk(sk)->inet_num = 0; 1300 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1301 1302 spin_lock(&hslot2->lock); 1303 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1304 hslot2->count--; 1305 spin_unlock(&hslot2->lock); 1306 } 1307 spin_unlock_bh(&hslot->lock); 1308 } 1309 } 1310 EXPORT_SYMBOL(udp_lib_unhash); 1311 1312 /* 1313 * inet_rcv_saddr was changed, we must rehash secondary hash 1314 */ 1315 void udp_lib_rehash(struct sock *sk, u16 newhash) 1316 { 1317 if (sk_hashed(sk)) { 1318 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1319 struct udp_hslot *hslot, *hslot2, *nhslot2; 1320 1321 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1322 nhslot2 = udp_hashslot2(udptable, newhash); 1323 udp_sk(sk)->udp_portaddr_hash = newhash; 1324 if (hslot2 != nhslot2) { 1325 hslot = udp_hashslot(udptable, sock_net(sk), 1326 udp_sk(sk)->udp_port_hash); 1327 /* we must lock primary chain too */ 1328 spin_lock_bh(&hslot->lock); 1329 1330 spin_lock(&hslot2->lock); 1331 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1332 hslot2->count--; 1333 spin_unlock(&hslot2->lock); 1334 1335 spin_lock(&nhslot2->lock); 1336 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1337 &nhslot2->head); 1338 nhslot2->count++; 1339 spin_unlock(&nhslot2->lock); 1340 1341 spin_unlock_bh(&hslot->lock); 1342 } 1343 } 1344 } 1345 EXPORT_SYMBOL(udp_lib_rehash); 1346 1347 static void udp_v4_rehash(struct sock *sk) 1348 { 1349 u16 new_hash = udp4_portaddr_hash(sock_net(sk), 1350 inet_sk(sk)->inet_rcv_saddr, 1351 inet_sk(sk)->inet_num); 1352 udp_lib_rehash(sk, new_hash); 1353 } 1354 1355 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1356 { 1357 int rc; 1358 1359 if (inet_sk(sk)->inet_daddr) 1360 sock_rps_save_rxhash(sk, skb); 1361 1362 rc = sock_queue_rcv_skb(sk, skb); 1363 if (rc < 0) { 1364 int is_udplite = IS_UDPLITE(sk); 1365 1366 /* Note that an ENOMEM error is charged twice */ 1367 if (rc == -ENOMEM) 1368 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1369 is_udplite); 1370 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1371 kfree_skb(skb); 1372 trace_udp_fail_queue_rcv_skb(rc, sk); 1373 return -1; 1374 } 1375 1376 return 0; 1377 1378 } 1379 1380 /* returns: 1381 * -1: error 1382 * 0: success 1383 * >0: "udp encap" protocol resubmission 1384 * 1385 * Note that in the success and error cases, the skb is assumed to 1386 * have either been requeued or freed. 1387 */ 1388 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1389 { 1390 struct udp_sock *up = udp_sk(sk); 1391 int rc; 1392 int is_udplite = IS_UDPLITE(sk); 1393 1394 /* 1395 * Charge it to the socket, dropping if the queue is full. 1396 */ 1397 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1398 goto drop; 1399 nf_reset(skb); 1400 1401 if (up->encap_type) { 1402 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 1403 1404 /* 1405 * This is an encapsulation socket so pass the skb to 1406 * the socket's udp_encap_rcv() hook. Otherwise, just 1407 * fall through and pass this up the UDP socket. 1408 * up->encap_rcv() returns the following value: 1409 * =0 if skb was successfully passed to the encap 1410 * handler or was discarded by it. 1411 * >0 if skb should be passed on to UDP. 1412 * <0 if skb should be resubmitted as proto -N 1413 */ 1414 1415 /* if we're overly short, let UDP handle it */ 1416 encap_rcv = ACCESS_ONCE(up->encap_rcv); 1417 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) { 1418 int ret; 1419 1420 ret = encap_rcv(sk, skb); 1421 if (ret <= 0) { 1422 UDP_INC_STATS_BH(sock_net(sk), 1423 UDP_MIB_INDATAGRAMS, 1424 is_udplite); 1425 return -ret; 1426 } 1427 } 1428 1429 /* FALLTHROUGH -- it's a UDP Packet */ 1430 } 1431 1432 /* 1433 * UDP-Lite specific tests, ignored on UDP sockets 1434 */ 1435 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1436 1437 /* 1438 * MIB statistics other than incrementing the error count are 1439 * disabled for the following two types of errors: these depend 1440 * on the application settings, not on the functioning of the 1441 * protocol stack as such. 1442 * 1443 * RFC 3828 here recommends (sec 3.3): "There should also be a 1444 * way ... to ... at least let the receiving application block 1445 * delivery of packets with coverage values less than a value 1446 * provided by the application." 1447 */ 1448 if (up->pcrlen == 0) { /* full coverage was set */ 1449 LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage " 1450 "%d while full coverage %d requested\n", 1451 UDP_SKB_CB(skb)->cscov, skb->len); 1452 goto drop; 1453 } 1454 /* The next case involves violating the min. coverage requested 1455 * by the receiver. This is subtle: if receiver wants x and x is 1456 * greater than the buffersize/MTU then receiver will complain 1457 * that it wants x while sender emits packets of smaller size y. 1458 * Therefore the above ...()->partial_cov statement is essential. 1459 */ 1460 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1461 LIMIT_NETDEBUG(KERN_WARNING 1462 "UDPLITE: coverage %d too small, need min %d\n", 1463 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1464 goto drop; 1465 } 1466 } 1467 1468 if (rcu_access_pointer(sk->sk_filter) && 1469 udp_lib_checksum_complete(skb)) 1470 goto drop; 1471 1472 1473 if (sk_rcvqueues_full(sk, skb)) 1474 goto drop; 1475 1476 rc = 0; 1477 1478 ipv4_pktinfo_prepare(skb); 1479 bh_lock_sock(sk); 1480 if (!sock_owned_by_user(sk)) 1481 rc = __udp_queue_rcv_skb(sk, skb); 1482 else if (sk_add_backlog(sk, skb)) { 1483 bh_unlock_sock(sk); 1484 goto drop; 1485 } 1486 bh_unlock_sock(sk); 1487 1488 return rc; 1489 1490 drop: 1491 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1492 atomic_inc(&sk->sk_drops); 1493 kfree_skb(skb); 1494 return -1; 1495 } 1496 1497 1498 static void flush_stack(struct sock **stack, unsigned int count, 1499 struct sk_buff *skb, unsigned int final) 1500 { 1501 unsigned int i; 1502 struct sk_buff *skb1 = NULL; 1503 struct sock *sk; 1504 1505 for (i = 0; i < count; i++) { 1506 sk = stack[i]; 1507 if (likely(skb1 == NULL)) 1508 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); 1509 1510 if (!skb1) { 1511 atomic_inc(&sk->sk_drops); 1512 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1513 IS_UDPLITE(sk)); 1514 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1515 IS_UDPLITE(sk)); 1516 } 1517 1518 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0) 1519 skb1 = NULL; 1520 } 1521 if (unlikely(skb1)) 1522 kfree_skb(skb1); 1523 } 1524 1525 /* 1526 * Multicasts and broadcasts go to each listener. 1527 * 1528 * Note: called only from the BH handler context. 1529 */ 1530 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 1531 struct udphdr *uh, 1532 __be32 saddr, __be32 daddr, 1533 struct udp_table *udptable) 1534 { 1535 struct sock *sk, *stack[256 / sizeof(struct sock *)]; 1536 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest)); 1537 int dif; 1538 unsigned int i, count = 0; 1539 1540 spin_lock(&hslot->lock); 1541 sk = sk_nulls_head(&hslot->head); 1542 dif = skb->dev->ifindex; 1543 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); 1544 while (sk) { 1545 stack[count++] = sk; 1546 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest, 1547 daddr, uh->source, saddr, dif); 1548 if (unlikely(count == ARRAY_SIZE(stack))) { 1549 if (!sk) 1550 break; 1551 flush_stack(stack, count, skb, ~0); 1552 count = 0; 1553 } 1554 } 1555 /* 1556 * before releasing chain lock, we must take a reference on sockets 1557 */ 1558 for (i = 0; i < count; i++) 1559 sock_hold(stack[i]); 1560 1561 spin_unlock(&hslot->lock); 1562 1563 /* 1564 * do the slow work with no lock held 1565 */ 1566 if (count) { 1567 flush_stack(stack, count, skb, count - 1); 1568 1569 for (i = 0; i < count; i++) 1570 sock_put(stack[i]); 1571 } else { 1572 kfree_skb(skb); 1573 } 1574 return 0; 1575 } 1576 1577 /* Initialize UDP checksum. If exited with zero value (success), 1578 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1579 * Otherwise, csum completion requires chacksumming packet body, 1580 * including udp header and folding it to skb->csum. 1581 */ 1582 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 1583 int proto) 1584 { 1585 const struct iphdr *iph; 1586 int err; 1587 1588 UDP_SKB_CB(skb)->partial_cov = 0; 1589 UDP_SKB_CB(skb)->cscov = skb->len; 1590 1591 if (proto == IPPROTO_UDPLITE) { 1592 err = udplite_checksum_init(skb, uh); 1593 if (err) 1594 return err; 1595 } 1596 1597 iph = ip_hdr(skb); 1598 if (uh->check == 0) { 1599 skb->ip_summed = CHECKSUM_UNNECESSARY; 1600 } else if (skb->ip_summed == CHECKSUM_COMPLETE) { 1601 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 1602 proto, skb->csum)) 1603 skb->ip_summed = CHECKSUM_UNNECESSARY; 1604 } 1605 if (!skb_csum_unnecessary(skb)) 1606 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, 1607 skb->len, proto, 0); 1608 /* Probably, we should checksum udp header (it should be in cache 1609 * in any case) and data in tiny packets (< rx copybreak). 1610 */ 1611 1612 return 0; 1613 } 1614 1615 /* 1616 * All we need to do is get the socket, and then do a checksum. 1617 */ 1618 1619 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 1620 int proto) 1621 { 1622 struct sock *sk; 1623 struct udphdr *uh; 1624 unsigned short ulen; 1625 struct rtable *rt = skb_rtable(skb); 1626 __be32 saddr, daddr; 1627 struct net *net = dev_net(skb->dev); 1628 1629 /* 1630 * Validate the packet. 1631 */ 1632 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1633 goto drop; /* No space for header. */ 1634 1635 uh = udp_hdr(skb); 1636 ulen = ntohs(uh->len); 1637 saddr = ip_hdr(skb)->saddr; 1638 daddr = ip_hdr(skb)->daddr; 1639 1640 if (ulen > skb->len) 1641 goto short_packet; 1642 1643 if (proto == IPPROTO_UDP) { 1644 /* UDP validates ulen. */ 1645 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1646 goto short_packet; 1647 uh = udp_hdr(skb); 1648 } 1649 1650 if (udp4_csum_init(skb, uh, proto)) 1651 goto csum_error; 1652 1653 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1654 return __udp4_lib_mcast_deliver(net, skb, uh, 1655 saddr, daddr, udptable); 1656 1657 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 1658 1659 if (sk != NULL) { 1660 int ret = udp_queue_rcv_skb(sk, skb); 1661 sock_put(sk); 1662 1663 /* a return value > 0 means to resubmit the input, but 1664 * it wants the return to be -protocol, or 0 1665 */ 1666 if (ret > 0) 1667 return -ret; 1668 return 0; 1669 } 1670 1671 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1672 goto drop; 1673 nf_reset(skb); 1674 1675 /* No socket. Drop packet silently, if checksum is wrong */ 1676 if (udp_lib_checksum_complete(skb)) 1677 goto csum_error; 1678 1679 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 1680 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1681 1682 /* 1683 * Hmm. We got an UDP packet to a port to which we 1684 * don't wanna listen. Ignore it. 1685 */ 1686 kfree_skb(skb); 1687 return 0; 1688 1689 short_packet: 1690 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 1691 proto == IPPROTO_UDPLITE ? "-Lite" : "", 1692 &saddr, 1693 ntohs(uh->source), 1694 ulen, 1695 skb->len, 1696 &daddr, 1697 ntohs(uh->dest)); 1698 goto drop; 1699 1700 csum_error: 1701 /* 1702 * RFC1122: OK. Discards the bad packet silently (as far as 1703 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1704 */ 1705 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 1706 proto == IPPROTO_UDPLITE ? "-Lite" : "", 1707 &saddr, 1708 ntohs(uh->source), 1709 &daddr, 1710 ntohs(uh->dest), 1711 ulen); 1712 drop: 1713 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1714 kfree_skb(skb); 1715 return 0; 1716 } 1717 1718 int udp_rcv(struct sk_buff *skb) 1719 { 1720 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 1721 } 1722 1723 void udp_destroy_sock(struct sock *sk) 1724 { 1725 bool slow = lock_sock_fast(sk); 1726 udp_flush_pending_frames(sk); 1727 unlock_sock_fast(sk, slow); 1728 } 1729 1730 /* 1731 * Socket option code for UDP 1732 */ 1733 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 1734 char __user *optval, unsigned int optlen, 1735 int (*push_pending_frames)(struct sock *)) 1736 { 1737 struct udp_sock *up = udp_sk(sk); 1738 int val; 1739 int err = 0; 1740 int is_udplite = IS_UDPLITE(sk); 1741 1742 if (optlen < sizeof(int)) 1743 return -EINVAL; 1744 1745 if (get_user(val, (int __user *)optval)) 1746 return -EFAULT; 1747 1748 switch (optname) { 1749 case UDP_CORK: 1750 if (val != 0) { 1751 up->corkflag = 1; 1752 } else { 1753 up->corkflag = 0; 1754 lock_sock(sk); 1755 (*push_pending_frames)(sk); 1756 release_sock(sk); 1757 } 1758 break; 1759 1760 case UDP_ENCAP: 1761 switch (val) { 1762 case 0: 1763 case UDP_ENCAP_ESPINUDP: 1764 case UDP_ENCAP_ESPINUDP_NON_IKE: 1765 up->encap_rcv = xfrm4_udp_encap_rcv; 1766 /* FALLTHROUGH */ 1767 case UDP_ENCAP_L2TPINUDP: 1768 up->encap_type = val; 1769 break; 1770 default: 1771 err = -ENOPROTOOPT; 1772 break; 1773 } 1774 break; 1775 1776 /* 1777 * UDP-Lite's partial checksum coverage (RFC 3828). 1778 */ 1779 /* The sender sets actual checksum coverage length via this option. 1780 * The case coverage > packet length is handled by send module. */ 1781 case UDPLITE_SEND_CSCOV: 1782 if (!is_udplite) /* Disable the option on UDP sockets */ 1783 return -ENOPROTOOPT; 1784 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 1785 val = 8; 1786 else if (val > USHRT_MAX) 1787 val = USHRT_MAX; 1788 up->pcslen = val; 1789 up->pcflag |= UDPLITE_SEND_CC; 1790 break; 1791 1792 /* The receiver specifies a minimum checksum coverage value. To make 1793 * sense, this should be set to at least 8 (as done below). If zero is 1794 * used, this again means full checksum coverage. */ 1795 case UDPLITE_RECV_CSCOV: 1796 if (!is_udplite) /* Disable the option on UDP sockets */ 1797 return -ENOPROTOOPT; 1798 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 1799 val = 8; 1800 else if (val > USHRT_MAX) 1801 val = USHRT_MAX; 1802 up->pcrlen = val; 1803 up->pcflag |= UDPLITE_RECV_CC; 1804 break; 1805 1806 default: 1807 err = -ENOPROTOOPT; 1808 break; 1809 } 1810 1811 return err; 1812 } 1813 EXPORT_SYMBOL(udp_lib_setsockopt); 1814 1815 int udp_setsockopt(struct sock *sk, int level, int optname, 1816 char __user *optval, unsigned int optlen) 1817 { 1818 if (level == SOL_UDP || level == SOL_UDPLITE) 1819 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1820 udp_push_pending_frames); 1821 return ip_setsockopt(sk, level, optname, optval, optlen); 1822 } 1823 1824 #ifdef CONFIG_COMPAT 1825 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 1826 char __user *optval, unsigned int optlen) 1827 { 1828 if (level == SOL_UDP || level == SOL_UDPLITE) 1829 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1830 udp_push_pending_frames); 1831 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 1832 } 1833 #endif 1834 1835 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 1836 char __user *optval, int __user *optlen) 1837 { 1838 struct udp_sock *up = udp_sk(sk); 1839 int val, len; 1840 1841 if (get_user(len, optlen)) 1842 return -EFAULT; 1843 1844 len = min_t(unsigned int, len, sizeof(int)); 1845 1846 if (len < 0) 1847 return -EINVAL; 1848 1849 switch (optname) { 1850 case UDP_CORK: 1851 val = up->corkflag; 1852 break; 1853 1854 case UDP_ENCAP: 1855 val = up->encap_type; 1856 break; 1857 1858 /* The following two cannot be changed on UDP sockets, the return is 1859 * always 0 (which corresponds to the full checksum coverage of UDP). */ 1860 case UDPLITE_SEND_CSCOV: 1861 val = up->pcslen; 1862 break; 1863 1864 case UDPLITE_RECV_CSCOV: 1865 val = up->pcrlen; 1866 break; 1867 1868 default: 1869 return -ENOPROTOOPT; 1870 } 1871 1872 if (put_user(len, optlen)) 1873 return -EFAULT; 1874 if (copy_to_user(optval, &val, len)) 1875 return -EFAULT; 1876 return 0; 1877 } 1878 EXPORT_SYMBOL(udp_lib_getsockopt); 1879 1880 int udp_getsockopt(struct sock *sk, int level, int optname, 1881 char __user *optval, int __user *optlen) 1882 { 1883 if (level == SOL_UDP || level == SOL_UDPLITE) 1884 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1885 return ip_getsockopt(sk, level, optname, optval, optlen); 1886 } 1887 1888 #ifdef CONFIG_COMPAT 1889 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 1890 char __user *optval, int __user *optlen) 1891 { 1892 if (level == SOL_UDP || level == SOL_UDPLITE) 1893 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1894 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 1895 } 1896 #endif 1897 /** 1898 * udp_poll - wait for a UDP event. 1899 * @file - file struct 1900 * @sock - socket 1901 * @wait - poll table 1902 * 1903 * This is same as datagram poll, except for the special case of 1904 * blocking sockets. If application is using a blocking fd 1905 * and a packet with checksum error is in the queue; 1906 * then it could get return from select indicating data available 1907 * but then block when reading it. Add special case code 1908 * to work around these arguably broken applications. 1909 */ 1910 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 1911 { 1912 unsigned int mask = datagram_poll(file, sock, wait); 1913 struct sock *sk = sock->sk; 1914 1915 /* Check for false positives due to checksum errors */ 1916 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 1917 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk)) 1918 mask &= ~(POLLIN | POLLRDNORM); 1919 1920 return mask; 1921 1922 } 1923 EXPORT_SYMBOL(udp_poll); 1924 1925 struct proto udp_prot = { 1926 .name = "UDP", 1927 .owner = THIS_MODULE, 1928 .close = udp_lib_close, 1929 .connect = ip4_datagram_connect, 1930 .disconnect = udp_disconnect, 1931 .ioctl = udp_ioctl, 1932 .destroy = udp_destroy_sock, 1933 .setsockopt = udp_setsockopt, 1934 .getsockopt = udp_getsockopt, 1935 .sendmsg = udp_sendmsg, 1936 .recvmsg = udp_recvmsg, 1937 .sendpage = udp_sendpage, 1938 .backlog_rcv = __udp_queue_rcv_skb, 1939 .hash = udp_lib_hash, 1940 .unhash = udp_lib_unhash, 1941 .rehash = udp_v4_rehash, 1942 .get_port = udp_v4_get_port, 1943 .memory_allocated = &udp_memory_allocated, 1944 .sysctl_mem = sysctl_udp_mem, 1945 .sysctl_wmem = &sysctl_udp_wmem_min, 1946 .sysctl_rmem = &sysctl_udp_rmem_min, 1947 .obj_size = sizeof(struct udp_sock), 1948 .slab_flags = SLAB_DESTROY_BY_RCU, 1949 .h.udp_table = &udp_table, 1950 #ifdef CONFIG_COMPAT 1951 .compat_setsockopt = compat_udp_setsockopt, 1952 .compat_getsockopt = compat_udp_getsockopt, 1953 #endif 1954 .clear_sk = sk_prot_clear_portaddr_nulls, 1955 }; 1956 EXPORT_SYMBOL(udp_prot); 1957 1958 /* ------------------------------------------------------------------------ */ 1959 #ifdef CONFIG_PROC_FS 1960 1961 static struct sock *udp_get_first(struct seq_file *seq, int start) 1962 { 1963 struct sock *sk; 1964 struct udp_iter_state *state = seq->private; 1965 struct net *net = seq_file_net(seq); 1966 1967 for (state->bucket = start; state->bucket <= state->udp_table->mask; 1968 ++state->bucket) { 1969 struct hlist_nulls_node *node; 1970 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; 1971 1972 if (hlist_nulls_empty(&hslot->head)) 1973 continue; 1974 1975 spin_lock_bh(&hslot->lock); 1976 sk_nulls_for_each(sk, node, &hslot->head) { 1977 if (!net_eq(sock_net(sk), net)) 1978 continue; 1979 if (sk->sk_family == state->family) 1980 goto found; 1981 } 1982 spin_unlock_bh(&hslot->lock); 1983 } 1984 sk = NULL; 1985 found: 1986 return sk; 1987 } 1988 1989 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 1990 { 1991 struct udp_iter_state *state = seq->private; 1992 struct net *net = seq_file_net(seq); 1993 1994 do { 1995 sk = sk_nulls_next(sk); 1996 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); 1997 1998 if (!sk) { 1999 if (state->bucket <= state->udp_table->mask) 2000 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2001 return udp_get_first(seq, state->bucket + 1); 2002 } 2003 return sk; 2004 } 2005 2006 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2007 { 2008 struct sock *sk = udp_get_first(seq, 0); 2009 2010 if (sk) 2011 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2012 --pos; 2013 return pos ? NULL : sk; 2014 } 2015 2016 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2017 { 2018 struct udp_iter_state *state = seq->private; 2019 state->bucket = MAX_UDP_PORTS; 2020 2021 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2022 } 2023 2024 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2025 { 2026 struct sock *sk; 2027 2028 if (v == SEQ_START_TOKEN) 2029 sk = udp_get_idx(seq, 0); 2030 else 2031 sk = udp_get_next(seq, v); 2032 2033 ++*pos; 2034 return sk; 2035 } 2036 2037 static void udp_seq_stop(struct seq_file *seq, void *v) 2038 { 2039 struct udp_iter_state *state = seq->private; 2040 2041 if (state->bucket <= state->udp_table->mask) 2042 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2043 } 2044 2045 int udp_seq_open(struct inode *inode, struct file *file) 2046 { 2047 struct udp_seq_afinfo *afinfo = PDE(inode)->data; 2048 struct udp_iter_state *s; 2049 int err; 2050 2051 err = seq_open_net(inode, file, &afinfo->seq_ops, 2052 sizeof(struct udp_iter_state)); 2053 if (err < 0) 2054 return err; 2055 2056 s = ((struct seq_file *)file->private_data)->private; 2057 s->family = afinfo->family; 2058 s->udp_table = afinfo->udp_table; 2059 return err; 2060 } 2061 EXPORT_SYMBOL(udp_seq_open); 2062 2063 /* ------------------------------------------------------------------------ */ 2064 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) 2065 { 2066 struct proc_dir_entry *p; 2067 int rc = 0; 2068 2069 afinfo->seq_ops.start = udp_seq_start; 2070 afinfo->seq_ops.next = udp_seq_next; 2071 afinfo->seq_ops.stop = udp_seq_stop; 2072 2073 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 2074 afinfo->seq_fops, afinfo); 2075 if (!p) 2076 rc = -ENOMEM; 2077 return rc; 2078 } 2079 EXPORT_SYMBOL(udp_proc_register); 2080 2081 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 2082 { 2083 proc_net_remove(net, afinfo->name); 2084 } 2085 EXPORT_SYMBOL(udp_proc_unregister); 2086 2087 /* ------------------------------------------------------------------------ */ 2088 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2089 int bucket, int *len) 2090 { 2091 struct inet_sock *inet = inet_sk(sp); 2092 __be32 dest = inet->inet_daddr; 2093 __be32 src = inet->inet_rcv_saddr; 2094 __u16 destp = ntohs(inet->inet_dport); 2095 __u16 srcp = ntohs(inet->inet_sport); 2096 2097 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2098 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n", 2099 bucket, src, srcp, dest, destp, sp->sk_state, 2100 sk_wmem_alloc_get(sp), 2101 sk_rmem_alloc_get(sp), 2102 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), 2103 atomic_read(&sp->sk_refcnt), sp, 2104 atomic_read(&sp->sk_drops), len); 2105 } 2106 2107 int udp4_seq_show(struct seq_file *seq, void *v) 2108 { 2109 if (v == SEQ_START_TOKEN) 2110 seq_printf(seq, "%-127s\n", 2111 " sl local_address rem_address st tx_queue " 2112 "rx_queue tr tm->when retrnsmt uid timeout " 2113 "inode ref pointer drops"); 2114 else { 2115 struct udp_iter_state *state = seq->private; 2116 int len; 2117 2118 udp4_format_sock(v, seq, state->bucket, &len); 2119 seq_printf(seq, "%*s\n", 127 - len, ""); 2120 } 2121 return 0; 2122 } 2123 2124 static const struct file_operations udp_afinfo_seq_fops = { 2125 .owner = THIS_MODULE, 2126 .open = udp_seq_open, 2127 .read = seq_read, 2128 .llseek = seq_lseek, 2129 .release = seq_release_net 2130 }; 2131 2132 /* ------------------------------------------------------------------------ */ 2133 static struct udp_seq_afinfo udp4_seq_afinfo = { 2134 .name = "udp", 2135 .family = AF_INET, 2136 .udp_table = &udp_table, 2137 .seq_fops = &udp_afinfo_seq_fops, 2138 .seq_ops = { 2139 .show = udp4_seq_show, 2140 }, 2141 }; 2142 2143 static int __net_init udp4_proc_init_net(struct net *net) 2144 { 2145 return udp_proc_register(net, &udp4_seq_afinfo); 2146 } 2147 2148 static void __net_exit udp4_proc_exit_net(struct net *net) 2149 { 2150 udp_proc_unregister(net, &udp4_seq_afinfo); 2151 } 2152 2153 static struct pernet_operations udp4_net_ops = { 2154 .init = udp4_proc_init_net, 2155 .exit = udp4_proc_exit_net, 2156 }; 2157 2158 int __init udp4_proc_init(void) 2159 { 2160 return register_pernet_subsys(&udp4_net_ops); 2161 } 2162 2163 void udp4_proc_exit(void) 2164 { 2165 unregister_pernet_subsys(&udp4_net_ops); 2166 } 2167 #endif /* CONFIG_PROC_FS */ 2168 2169 static __initdata unsigned long uhash_entries; 2170 static int __init set_uhash_entries(char *str) 2171 { 2172 if (!str) 2173 return 0; 2174 uhash_entries = simple_strtoul(str, &str, 0); 2175 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2176 uhash_entries = UDP_HTABLE_SIZE_MIN; 2177 return 1; 2178 } 2179 __setup("uhash_entries=", set_uhash_entries); 2180 2181 void __init udp_table_init(struct udp_table *table, const char *name) 2182 { 2183 unsigned int i; 2184 2185 if (!CONFIG_BASE_SMALL) 2186 table->hash = alloc_large_system_hash(name, 2187 2 * sizeof(struct udp_hslot), 2188 uhash_entries, 2189 21, /* one slot per 2 MB */ 2190 0, 2191 &table->log, 2192 &table->mask, 2193 64 * 1024); 2194 /* 2195 * Make sure hash table has the minimum size 2196 */ 2197 if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) { 2198 table->hash = kmalloc(UDP_HTABLE_SIZE_MIN * 2199 2 * sizeof(struct udp_hslot), GFP_KERNEL); 2200 if (!table->hash) 2201 panic(name); 2202 table->log = ilog2(UDP_HTABLE_SIZE_MIN); 2203 table->mask = UDP_HTABLE_SIZE_MIN - 1; 2204 } 2205 table->hash2 = table->hash + (table->mask + 1); 2206 for (i = 0; i <= table->mask; i++) { 2207 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); 2208 table->hash[i].count = 0; 2209 spin_lock_init(&table->hash[i].lock); 2210 } 2211 for (i = 0; i <= table->mask; i++) { 2212 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); 2213 table->hash2[i].count = 0; 2214 spin_lock_init(&table->hash2[i].lock); 2215 } 2216 } 2217 2218 void __init udp_init(void) 2219 { 2220 unsigned long limit; 2221 2222 udp_table_init(&udp_table, "UDP"); 2223 limit = nr_free_buffer_pages() / 8; 2224 limit = max(limit, 128UL); 2225 sysctl_udp_mem[0] = limit / 4 * 3; 2226 sysctl_udp_mem[1] = limit; 2227 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 2228 2229 sysctl_udp_rmem_min = SK_MEM_QUANTUM; 2230 sysctl_udp_wmem_min = SK_MEM_QUANTUM; 2231 } 2232 2233 int udp4_ufo_send_check(struct sk_buff *skb) 2234 { 2235 const struct iphdr *iph; 2236 struct udphdr *uh; 2237 2238 if (!pskb_may_pull(skb, sizeof(*uh))) 2239 return -EINVAL; 2240 2241 iph = ip_hdr(skb); 2242 uh = udp_hdr(skb); 2243 2244 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 2245 IPPROTO_UDP, 0); 2246 skb->csum_start = skb_transport_header(skb) - skb->head; 2247 skb->csum_offset = offsetof(struct udphdr, check); 2248 skb->ip_summed = CHECKSUM_PARTIAL; 2249 return 0; 2250 } 2251 2252 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 2253 netdev_features_t features) 2254 { 2255 struct sk_buff *segs = ERR_PTR(-EINVAL); 2256 unsigned int mss; 2257 int offset; 2258 __wsum csum; 2259 2260 mss = skb_shinfo(skb)->gso_size; 2261 if (unlikely(skb->len <= mss)) 2262 goto out; 2263 2264 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2265 /* Packet is from an untrusted source, reset gso_segs. */ 2266 int type = skb_shinfo(skb)->gso_type; 2267 2268 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) || 2269 !(type & (SKB_GSO_UDP)))) 2270 goto out; 2271 2272 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2273 2274 segs = NULL; 2275 goto out; 2276 } 2277 2278 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot 2279 * do checksum of UDP packets sent as multiple IP fragments. 2280 */ 2281 offset = skb_checksum_start_offset(skb); 2282 csum = skb_checksum(skb, offset, skb->len - offset, 0); 2283 offset += skb->csum_offset; 2284 *(__sum16 *)(skb->data + offset) = csum_fold(csum); 2285 skb->ip_summed = CHECKSUM_NONE; 2286 2287 /* Fragment the skb. IP headers of the fragments are updated in 2288 * inet_gso_segment() 2289 */ 2290 segs = skb_segment(skb, features); 2291 out: 2292 return segs; 2293 } 2294 2295