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