1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * The User Datagram Protocol (UDP). 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 11 * Alan Cox, <alan@lxorguk.ukuu.org.uk> 12 * Hirokazu Takahashi, <taka@valinux.co.jp> 13 * 14 * Fixes: 15 * Alan Cox : verify_area() calls 16 * Alan Cox : stopped close while in use off icmp 17 * messages. Not a fix but a botch that 18 * for udp at least is 'valid'. 19 * Alan Cox : Fixed icmp handling properly 20 * Alan Cox : Correct error for oversized datagrams 21 * Alan Cox : Tidied select() semantics. 22 * Alan Cox : udp_err() fixed properly, also now 23 * select and read wake correctly on errors 24 * Alan Cox : udp_send verify_area moved to avoid mem leak 25 * Alan Cox : UDP can count its memory 26 * Alan Cox : send to an unknown connection causes 27 * an ECONNREFUSED off the icmp, but 28 * does NOT close. 29 * Alan Cox : Switched to new sk_buff handlers. No more backlog! 30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK 31 * bug no longer crashes it. 32 * Fred Van Kempen : Net2e support for sk->broadcast. 33 * Alan Cox : Uses skb_free_datagram 34 * Alan Cox : Added get/set sockopt support. 35 * Alan Cox : Broadcasting without option set returns EACCES. 36 * Alan Cox : No wakeup calls. Instead we now use the callbacks. 37 * Alan Cox : Use ip_tos and ip_ttl 38 * Alan Cox : SNMP Mibs 39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support. 40 * Matt Dillon : UDP length checks. 41 * Alan Cox : Smarter af_inet used properly. 42 * Alan Cox : Use new kernel side addressing. 43 * Alan Cox : Incorrect return on truncated datagram receive. 44 * Arnt Gulbrandsen : New udp_send and stuff 45 * Alan Cox : Cache last socket 46 * Alan Cox : Route cache 47 * Jon Peatfield : Minor efficiency fix to sendto(). 48 * Mike Shaver : RFC1122 checks. 49 * Alan Cox : Nonblocking error fix. 50 * Willy Konynenberg : Transparent proxying support. 51 * Mike McLagan : Routing by source 52 * David S. Miller : New socket lookup architecture. 53 * Last socket cache retained as it 54 * does have a high hit rate. 55 * Olaf Kirch : Don't linearise iovec on sendmsg. 56 * Andi Kleen : Some cleanups, cache destination entry 57 * for connect. 58 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 59 * Melvin Smith : Check msg_name not msg_namelen in sendto(), 60 * return ENOTCONN for unconnected sockets (POSIX) 61 * Janos Farkas : don't deliver multi/broadcasts to a different 62 * bound-to-device socket 63 * Hirokazu Takahashi : HW checksumming for outgoing UDP 64 * datagrams. 65 * Hirokazu Takahashi : sendfile() on UDP works now. 66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file 67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind 69 * a single port at the same time. 70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support 71 * James Chapman : Add L2TP encapsulation type. 72 * 73 * 74 * This program is free software; you can redistribute it and/or 75 * modify it under the terms of the GNU General Public License 76 * as published by the Free Software Foundation; either version 77 * 2 of the License, or (at your option) any later version. 78 */ 79 80 #define pr_fmt(fmt) "UDP: " fmt 81 82 #include <asm/system.h> 83 #include <asm/uaccess.h> 84 #include <asm/ioctls.h> 85 #include <linux/bootmem.h> 86 #include <linux/highmem.h> 87 #include <linux/swap.h> 88 #include <linux/types.h> 89 #include <linux/fcntl.h> 90 #include <linux/module.h> 91 #include <linux/socket.h> 92 #include <linux/sockios.h> 93 #include <linux/igmp.h> 94 #include <linux/in.h> 95 #include <linux/errno.h> 96 #include <linux/timer.h> 97 #include <linux/mm.h> 98 #include <linux/inet.h> 99 #include <linux/netdevice.h> 100 #include <linux/slab.h> 101 #include <net/tcp_states.h> 102 #include <linux/skbuff.h> 103 #include <linux/proc_fs.h> 104 #include <linux/seq_file.h> 105 #include <net/net_namespace.h> 106 #include <net/icmp.h> 107 #include <net/route.h> 108 #include <net/checksum.h> 109 #include <net/xfrm.h> 110 #include <trace/events/udp.h> 111 #include "udp_impl.h" 112 113 struct udp_table udp_table __read_mostly; 114 EXPORT_SYMBOL(udp_table); 115 116 long sysctl_udp_mem[3] __read_mostly; 117 EXPORT_SYMBOL(sysctl_udp_mem); 118 119 int sysctl_udp_rmem_min __read_mostly; 120 EXPORT_SYMBOL(sysctl_udp_rmem_min); 121 122 int sysctl_udp_wmem_min __read_mostly; 123 EXPORT_SYMBOL(sysctl_udp_wmem_min); 124 125 atomic_long_t udp_memory_allocated; 126 EXPORT_SYMBOL(udp_memory_allocated); 127 128 #define MAX_UDP_PORTS 65536 129 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN) 130 131 static int udp_lib_lport_inuse(struct net *net, __u16 num, 132 const struct udp_hslot *hslot, 133 unsigned long *bitmap, 134 struct sock *sk, 135 int (*saddr_comp)(const struct sock *sk1, 136 const struct sock *sk2), 137 unsigned int log) 138 { 139 struct sock *sk2; 140 struct hlist_nulls_node *node; 141 142 sk_nulls_for_each(sk2, node, &hslot->head) 143 if (net_eq(sock_net(sk2), net) && 144 sk2 != sk && 145 (bitmap || udp_sk(sk2)->udp_port_hash == num) && 146 (!sk2->sk_reuse || !sk->sk_reuse) && 147 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 148 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 149 (*saddr_comp)(sk, sk2)) { 150 if (bitmap) 151 __set_bit(udp_sk(sk2)->udp_port_hash >> log, 152 bitmap); 153 else 154 return 1; 155 } 156 return 0; 157 } 158 159 /* 160 * Note: we still hold spinlock of primary hash chain, so no other writer 161 * can insert/delete a socket with local_port == num 162 */ 163 static int udp_lib_lport_inuse2(struct net *net, __u16 num, 164 struct udp_hslot *hslot2, 165 struct sock *sk, 166 int (*saddr_comp)(const struct sock *sk1, 167 const struct sock *sk2)) 168 { 169 struct sock *sk2; 170 struct hlist_nulls_node *node; 171 int res = 0; 172 173 spin_lock(&hslot2->lock); 174 udp_portaddr_for_each_entry(sk2, node, &hslot2->head) 175 if (net_eq(sock_net(sk2), net) && 176 sk2 != sk && 177 (udp_sk(sk2)->udp_port_hash == num) && 178 (!sk2->sk_reuse || !sk->sk_reuse) && 179 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if || 180 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) && 181 (*saddr_comp)(sk, sk2)) { 182 res = 1; 183 break; 184 } 185 spin_unlock(&hslot2->lock); 186 return res; 187 } 188 189 /** 190 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6 191 * 192 * @sk: socket struct in question 193 * @snum: port number to look up 194 * @saddr_comp: AF-dependent comparison of bound local IP addresses 195 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains, 196 * with NULL address 197 */ 198 int udp_lib_get_port(struct sock *sk, unsigned short snum, 199 int (*saddr_comp)(const struct sock *sk1, 200 const struct sock *sk2), 201 unsigned int hash2_nulladdr) 202 { 203 struct udp_hslot *hslot, *hslot2; 204 struct udp_table *udptable = sk->sk_prot->h.udp_table; 205 int error = 1; 206 struct net *net = sock_net(sk); 207 208 if (!snum) { 209 int low, high, remaining; 210 unsigned rand; 211 unsigned short first, last; 212 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN); 213 214 inet_get_local_port_range(&low, &high); 215 remaining = (high - low) + 1; 216 217 rand = net_random(); 218 first = (((u64)rand * remaining) >> 32) + low; 219 /* 220 * force rand to be an odd multiple of UDP_HTABLE_SIZE 221 */ 222 rand = (rand | 1) * (udptable->mask + 1); 223 last = first + udptable->mask + 1; 224 do { 225 hslot = udp_hashslot(udptable, net, first); 226 bitmap_zero(bitmap, PORTS_PER_CHAIN); 227 spin_lock_bh(&hslot->lock); 228 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk, 229 saddr_comp, udptable->log); 230 231 snum = first; 232 /* 233 * Iterate on all possible values of snum for this hash. 234 * Using steps of an odd multiple of UDP_HTABLE_SIZE 235 * give us randomization and full range coverage. 236 */ 237 do { 238 if (low <= snum && snum <= high && 239 !test_bit(snum >> udptable->log, bitmap) && 240 !inet_is_reserved_local_port(snum)) 241 goto found; 242 snum += rand; 243 } while (snum != first); 244 spin_unlock_bh(&hslot->lock); 245 } while (++first != last); 246 goto fail; 247 } else { 248 hslot = udp_hashslot(udptable, net, snum); 249 spin_lock_bh(&hslot->lock); 250 if (hslot->count > 10) { 251 int exist; 252 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum; 253 254 slot2 &= udptable->mask; 255 hash2_nulladdr &= udptable->mask; 256 257 hslot2 = udp_hashslot2(udptable, slot2); 258 if (hslot->count < hslot2->count) 259 goto scan_primary_hash; 260 261 exist = udp_lib_lport_inuse2(net, snum, hslot2, 262 sk, saddr_comp); 263 if (!exist && (hash2_nulladdr != slot2)) { 264 hslot2 = udp_hashslot2(udptable, hash2_nulladdr); 265 exist = udp_lib_lport_inuse2(net, snum, hslot2, 266 sk, saddr_comp); 267 } 268 if (exist) 269 goto fail_unlock; 270 else 271 goto found; 272 } 273 scan_primary_hash: 274 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 275 saddr_comp, 0)) 276 goto fail_unlock; 277 } 278 found: 279 inet_sk(sk)->inet_num = snum; 280 udp_sk(sk)->udp_port_hash = snum; 281 udp_sk(sk)->udp_portaddr_hash ^= snum; 282 if (sk_unhashed(sk)) { 283 sk_nulls_add_node_rcu(sk, &hslot->head); 284 hslot->count++; 285 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 286 287 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 288 spin_lock(&hslot2->lock); 289 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 290 &hslot2->head); 291 hslot2->count++; 292 spin_unlock(&hslot2->lock); 293 } 294 error = 0; 295 fail_unlock: 296 spin_unlock_bh(&hslot->lock); 297 fail: 298 return error; 299 } 300 EXPORT_SYMBOL(udp_lib_get_port); 301 302 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) 303 { 304 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); 305 306 return (!ipv6_only_sock(sk2) && 307 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr || 308 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr)); 309 } 310 311 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr, 312 unsigned int port) 313 { 314 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 315 } 316 317 int udp_v4_get_port(struct sock *sk, unsigned short snum) 318 { 319 unsigned int hash2_nulladdr = 320 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum); 321 unsigned int hash2_partial = 322 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0); 323 324 /* precompute partial secondary hash */ 325 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 326 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr); 327 } 328 329 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr, 330 unsigned short hnum, 331 __be16 sport, __be32 daddr, __be16 dport, int dif) 332 { 333 int score = -1; 334 335 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum && 336 !ipv6_only_sock(sk)) { 337 struct inet_sock *inet = inet_sk(sk); 338 339 score = (sk->sk_family == PF_INET ? 1 : 0); 340 if (inet->inet_rcv_saddr) { 341 if (inet->inet_rcv_saddr != daddr) 342 return -1; 343 score += 2; 344 } 345 if (inet->inet_daddr) { 346 if (inet->inet_daddr != saddr) 347 return -1; 348 score += 2; 349 } 350 if (inet->inet_dport) { 351 if (inet->inet_dport != sport) 352 return -1; 353 score += 2; 354 } 355 if (sk->sk_bound_dev_if) { 356 if (sk->sk_bound_dev_if != dif) 357 return -1; 358 score += 2; 359 } 360 } 361 return score; 362 } 363 364 /* 365 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num) 366 */ 367 #define SCORE2_MAX (1 + 2 + 2 + 2) 368 static inline int compute_score2(struct sock *sk, struct net *net, 369 __be32 saddr, __be16 sport, 370 __be32 daddr, unsigned int hnum, int dif) 371 { 372 int score = -1; 373 374 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) { 375 struct inet_sock *inet = inet_sk(sk); 376 377 if (inet->inet_rcv_saddr != daddr) 378 return -1; 379 if (inet->inet_num != hnum) 380 return -1; 381 382 score = (sk->sk_family == PF_INET ? 1 : 0); 383 if (inet->inet_daddr) { 384 if (inet->inet_daddr != saddr) 385 return -1; 386 score += 2; 387 } 388 if (inet->inet_dport) { 389 if (inet->inet_dport != sport) 390 return -1; 391 score += 2; 392 } 393 if (sk->sk_bound_dev_if) { 394 if (sk->sk_bound_dev_if != dif) 395 return -1; 396 score += 2; 397 } 398 } 399 return score; 400 } 401 402 403 /* called with read_rcu_lock() */ 404 static struct sock *udp4_lib_lookup2(struct net *net, 405 __be32 saddr, __be16 sport, 406 __be32 daddr, unsigned int hnum, int dif, 407 struct udp_hslot *hslot2, unsigned int slot2) 408 { 409 struct sock *sk, *result; 410 struct hlist_nulls_node *node; 411 int score, badness; 412 413 begin: 414 result = NULL; 415 badness = -1; 416 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { 417 score = compute_score2(sk, net, saddr, sport, 418 daddr, hnum, dif); 419 if (score > badness) { 420 result = sk; 421 badness = score; 422 if (score == SCORE2_MAX) 423 goto exact_match; 424 } 425 } 426 /* 427 * if the nulls value we got at the end of this lookup is 428 * not the expected one, we must restart lookup. 429 * We probably met an item that was moved to another chain. 430 */ 431 if (get_nulls_value(node) != slot2) 432 goto begin; 433 434 if (result) { 435 exact_match: 436 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 437 result = NULL; 438 else if (unlikely(compute_score2(result, net, saddr, sport, 439 daddr, hnum, dif) < badness)) { 440 sock_put(result); 441 goto begin; 442 } 443 } 444 return result; 445 } 446 447 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try 448 * harder than this. -DaveM 449 */ 450 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, 451 __be16 sport, __be32 daddr, __be16 dport, 452 int dif, struct udp_table *udptable) 453 { 454 struct sock *sk, *result; 455 struct hlist_nulls_node *node; 456 unsigned short hnum = ntohs(dport); 457 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); 458 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; 459 int score, badness; 460 461 rcu_read_lock(); 462 if (hslot->count > 10) { 463 hash2 = udp4_portaddr_hash(net, daddr, hnum); 464 slot2 = hash2 & udptable->mask; 465 hslot2 = &udptable->hash2[slot2]; 466 if (hslot->count < hslot2->count) 467 goto begin; 468 469 result = udp4_lib_lookup2(net, saddr, sport, 470 daddr, hnum, dif, 471 hslot2, slot2); 472 if (!result) { 473 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); 474 slot2 = hash2 & udptable->mask; 475 hslot2 = &udptable->hash2[slot2]; 476 if (hslot->count < hslot2->count) 477 goto begin; 478 479 result = udp4_lib_lookup2(net, saddr, sport, 480 htonl(INADDR_ANY), hnum, dif, 481 hslot2, slot2); 482 } 483 rcu_read_unlock(); 484 return result; 485 } 486 begin: 487 result = NULL; 488 badness = -1; 489 sk_nulls_for_each_rcu(sk, node, &hslot->head) { 490 score = compute_score(sk, net, saddr, hnum, sport, 491 daddr, dport, dif); 492 if (score > badness) { 493 result = sk; 494 badness = score; 495 } 496 } 497 /* 498 * if the nulls value we got at the end of this lookup is 499 * not the expected one, we must restart lookup. 500 * We probably met an item that was moved to another chain. 501 */ 502 if (get_nulls_value(node) != slot) 503 goto begin; 504 505 if (result) { 506 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2))) 507 result = NULL; 508 else if (unlikely(compute_score(result, net, saddr, hnum, sport, 509 daddr, dport, dif) < badness)) { 510 sock_put(result); 511 goto begin; 512 } 513 } 514 rcu_read_unlock(); 515 return result; 516 } 517 EXPORT_SYMBOL_GPL(__udp4_lib_lookup); 518 519 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb, 520 __be16 sport, __be16 dport, 521 struct udp_table *udptable) 522 { 523 struct sock *sk; 524 const struct iphdr *iph = ip_hdr(skb); 525 526 if (unlikely(sk = skb_steal_sock(skb))) 527 return sk; 528 else 529 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport, 530 iph->daddr, dport, inet_iif(skb), 531 udptable); 532 } 533 534 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 535 __be32 daddr, __be16 dport, int dif) 536 { 537 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table); 538 } 539 EXPORT_SYMBOL_GPL(udp4_lib_lookup); 540 541 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk, 542 __be16 loc_port, __be32 loc_addr, 543 __be16 rmt_port, __be32 rmt_addr, 544 int dif) 545 { 546 struct hlist_nulls_node *node; 547 struct sock *s = sk; 548 unsigned short hnum = ntohs(loc_port); 549 550 sk_nulls_for_each_from(s, node) { 551 struct inet_sock *inet = inet_sk(s); 552 553 if (!net_eq(sock_net(s), net) || 554 udp_sk(s)->udp_port_hash != hnum || 555 (inet->inet_daddr && inet->inet_daddr != rmt_addr) || 556 (inet->inet_dport != rmt_port && inet->inet_dport) || 557 (inet->inet_rcv_saddr && 558 inet->inet_rcv_saddr != loc_addr) || 559 ipv6_only_sock(s) || 560 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) 561 continue; 562 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) 563 continue; 564 goto found; 565 } 566 s = NULL; 567 found: 568 return s; 569 } 570 571 /* 572 * This routine is called by the ICMP module when it gets some 573 * sort of error condition. If err < 0 then the socket should 574 * be closed and the error returned to the user. If err > 0 575 * it's just the icmp type << 8 | icmp code. 576 * Header points to the ip header of the error packet. We move 577 * on past this. Then (as it used to claim before adjustment) 578 * header points to the first 8 bytes of the udp header. We need 579 * to find the appropriate port. 580 */ 581 582 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) 583 { 584 struct inet_sock *inet; 585 const struct iphdr *iph = (const struct iphdr *)skb->data; 586 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2)); 587 const int type = icmp_hdr(skb)->type; 588 const int code = icmp_hdr(skb)->code; 589 struct sock *sk; 590 int harderr; 591 int err; 592 struct net *net = dev_net(skb->dev); 593 594 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest, 595 iph->saddr, uh->source, skb->dev->ifindex, udptable); 596 if (sk == NULL) { 597 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); 598 return; /* No socket for error */ 599 } 600 601 err = 0; 602 harderr = 0; 603 inet = inet_sk(sk); 604 605 switch (type) { 606 default: 607 case ICMP_TIME_EXCEEDED: 608 err = EHOSTUNREACH; 609 break; 610 case ICMP_SOURCE_QUENCH: 611 goto out; 612 case ICMP_PARAMETERPROB: 613 err = EPROTO; 614 harderr = 1; 615 break; 616 case ICMP_DEST_UNREACH: 617 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 618 if (inet->pmtudisc != IP_PMTUDISC_DONT) { 619 err = EMSGSIZE; 620 harderr = 1; 621 break; 622 } 623 goto out; 624 } 625 err = EHOSTUNREACH; 626 if (code <= NR_ICMP_UNREACH) { 627 harderr = icmp_err_convert[code].fatal; 628 err = icmp_err_convert[code].errno; 629 } 630 break; 631 } 632 633 /* 634 * RFC1122: OK. Passes ICMP errors back to application, as per 635 * 4.1.3.3. 636 */ 637 if (!inet->recverr) { 638 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 639 goto out; 640 } else 641 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); 642 643 sk->sk_err = err; 644 sk->sk_error_report(sk); 645 out: 646 sock_put(sk); 647 } 648 649 void udp_err(struct sk_buff *skb, u32 info) 650 { 651 __udp4_lib_err(skb, info, &udp_table); 652 } 653 654 /* 655 * Throw away all pending data and cancel the corking. Socket is locked. 656 */ 657 void udp_flush_pending_frames(struct sock *sk) 658 { 659 struct udp_sock *up = udp_sk(sk); 660 661 if (up->pending) { 662 up->len = 0; 663 up->pending = 0; 664 ip_flush_pending_frames(sk); 665 } 666 } 667 EXPORT_SYMBOL(udp_flush_pending_frames); 668 669 /** 670 * udp4_hwcsum - handle outgoing HW checksumming 671 * @skb: sk_buff containing the filled-in UDP header 672 * (checksum field must be zeroed out) 673 * @src: source IP address 674 * @dst: destination IP address 675 */ 676 static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst) 677 { 678 struct udphdr *uh = udp_hdr(skb); 679 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 680 int offset = skb_transport_offset(skb); 681 int len = skb->len - offset; 682 int hlen = len; 683 __wsum csum = 0; 684 685 if (!frags) { 686 /* 687 * Only one fragment on the socket. 688 */ 689 skb->csum_start = skb_transport_header(skb) - skb->head; 690 skb->csum_offset = offsetof(struct udphdr, check); 691 uh->check = ~csum_tcpudp_magic(src, dst, len, 692 IPPROTO_UDP, 0); 693 } else { 694 /* 695 * HW-checksum won't work as there are two or more 696 * fragments on the socket so that all csums of sk_buffs 697 * should be together 698 */ 699 do { 700 csum = csum_add(csum, frags->csum); 701 hlen -= frags->len; 702 } while ((frags = frags->next)); 703 704 csum = skb_checksum(skb, offset, hlen, csum); 705 skb->ip_summed = CHECKSUM_NONE; 706 707 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); 708 if (uh->check == 0) 709 uh->check = CSUM_MANGLED_0; 710 } 711 } 712 713 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4) 714 { 715 struct sock *sk = skb->sk; 716 struct inet_sock *inet = inet_sk(sk); 717 struct udphdr *uh; 718 int err = 0; 719 int is_udplite = IS_UDPLITE(sk); 720 int offset = skb_transport_offset(skb); 721 int len = skb->len - offset; 722 __wsum csum = 0; 723 724 /* 725 * Create a UDP header 726 */ 727 uh = udp_hdr(skb); 728 uh->source = inet->inet_sport; 729 uh->dest = fl4->fl4_dport; 730 uh->len = htons(len); 731 uh->check = 0; 732 733 if (is_udplite) /* UDP-Lite */ 734 csum = udplite_csum(skb); 735 736 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ 737 738 skb->ip_summed = CHECKSUM_NONE; 739 goto send; 740 741 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 742 743 udp4_hwcsum(skb, fl4->saddr, fl4->daddr); 744 goto send; 745 746 } else 747 csum = udp_csum(skb); 748 749 /* add protocol-dependent pseudo-header */ 750 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len, 751 sk->sk_protocol, csum); 752 if (uh->check == 0) 753 uh->check = CSUM_MANGLED_0; 754 755 send: 756 err = ip_send_skb(skb); 757 if (err) { 758 if (err == -ENOBUFS && !inet->recverr) { 759 UDP_INC_STATS_USER(sock_net(sk), 760 UDP_MIB_SNDBUFERRORS, is_udplite); 761 err = 0; 762 } 763 } else 764 UDP_INC_STATS_USER(sock_net(sk), 765 UDP_MIB_OUTDATAGRAMS, is_udplite); 766 return err; 767 } 768 769 /* 770 * Push out all pending data as one UDP datagram. Socket is locked. 771 */ 772 static int udp_push_pending_frames(struct sock *sk) 773 { 774 struct udp_sock *up = udp_sk(sk); 775 struct inet_sock *inet = inet_sk(sk); 776 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 777 struct sk_buff *skb; 778 int err = 0; 779 780 skb = ip_finish_skb(sk, fl4); 781 if (!skb) 782 goto out; 783 784 err = udp_send_skb(skb, fl4); 785 786 out: 787 up->len = 0; 788 up->pending = 0; 789 return err; 790 } 791 792 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 793 size_t len) 794 { 795 struct inet_sock *inet = inet_sk(sk); 796 struct udp_sock *up = udp_sk(sk); 797 struct flowi4 fl4_stack; 798 struct flowi4 *fl4; 799 int ulen = len; 800 struct ipcm_cookie ipc; 801 struct rtable *rt = NULL; 802 int free = 0; 803 int connected = 0; 804 __be32 daddr, faddr, saddr; 805 __be16 dport; 806 u8 tos; 807 int err, is_udplite = IS_UDPLITE(sk); 808 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 809 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 810 struct sk_buff *skb; 811 struct ip_options_data opt_copy; 812 813 if (len > 0xFFFF) 814 return -EMSGSIZE; 815 816 /* 817 * Check the flags. 818 */ 819 820 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ 821 return -EOPNOTSUPP; 822 823 ipc.opt = NULL; 824 ipc.tx_flags = 0; 825 826 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 827 828 fl4 = &inet->cork.fl.u.ip4; 829 if (up->pending) { 830 /* 831 * There are pending frames. 832 * The socket lock must be held while it's corked. 833 */ 834 lock_sock(sk); 835 if (likely(up->pending)) { 836 if (unlikely(up->pending != AF_INET)) { 837 release_sock(sk); 838 return -EINVAL; 839 } 840 goto do_append_data; 841 } 842 release_sock(sk); 843 } 844 ulen += sizeof(struct udphdr); 845 846 /* 847 * Get and verify the address. 848 */ 849 if (msg->msg_name) { 850 struct sockaddr_in * usin = (struct sockaddr_in *)msg->msg_name; 851 if (msg->msg_namelen < sizeof(*usin)) 852 return -EINVAL; 853 if (usin->sin_family != AF_INET) { 854 if (usin->sin_family != AF_UNSPEC) 855 return -EAFNOSUPPORT; 856 } 857 858 daddr = usin->sin_addr.s_addr; 859 dport = usin->sin_port; 860 if (dport == 0) 861 return -EINVAL; 862 } else { 863 if (sk->sk_state != TCP_ESTABLISHED) 864 return -EDESTADDRREQ; 865 daddr = inet->inet_daddr; 866 dport = inet->inet_dport; 867 /* Open fast path for connected socket. 868 Route will not be used, if at least one option is set. 869 */ 870 connected = 1; 871 } 872 ipc.addr = inet->inet_saddr; 873 874 ipc.oif = sk->sk_bound_dev_if; 875 err = sock_tx_timestamp(sk, &ipc.tx_flags); 876 if (err) 877 return err; 878 if (msg->msg_controllen) { 879 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 880 if (err) 881 return err; 882 if (ipc.opt) 883 free = 1; 884 connected = 0; 885 } 886 if (!ipc.opt) { 887 struct ip_options_rcu *inet_opt; 888 889 rcu_read_lock(); 890 inet_opt = rcu_dereference(inet->inet_opt); 891 if (inet_opt) { 892 memcpy(&opt_copy, inet_opt, 893 sizeof(*inet_opt) + inet_opt->opt.optlen); 894 ipc.opt = &opt_copy.opt; 895 } 896 rcu_read_unlock(); 897 } 898 899 saddr = ipc.addr; 900 ipc.addr = faddr = daddr; 901 902 if (ipc.opt && ipc.opt->opt.srr) { 903 if (!daddr) 904 return -EINVAL; 905 faddr = ipc.opt->opt.faddr; 906 connected = 0; 907 } 908 tos = RT_TOS(inet->tos); 909 if (sock_flag(sk, SOCK_LOCALROUTE) || 910 (msg->msg_flags & MSG_DONTROUTE) || 911 (ipc.opt && ipc.opt->opt.is_strictroute)) { 912 tos |= RTO_ONLINK; 913 connected = 0; 914 } 915 916 if (ipv4_is_multicast(daddr)) { 917 if (!ipc.oif) 918 ipc.oif = inet->mc_index; 919 if (!saddr) 920 saddr = inet->mc_addr; 921 connected = 0; 922 } else if (!ipc.oif) 923 ipc.oif = inet->uc_index; 924 925 if (connected) 926 rt = (struct rtable *)sk_dst_check(sk, 0); 927 928 if (rt == NULL) { 929 struct net *net = sock_net(sk); 930 931 fl4 = &fl4_stack; 932 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos, 933 RT_SCOPE_UNIVERSE, sk->sk_protocol, 934 inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP, 935 faddr, saddr, dport, inet->inet_sport); 936 937 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 938 rt = ip_route_output_flow(net, fl4, sk); 939 if (IS_ERR(rt)) { 940 err = PTR_ERR(rt); 941 rt = NULL; 942 if (err == -ENETUNREACH) 943 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 944 goto out; 945 } 946 947 err = -EACCES; 948 if ((rt->rt_flags & RTCF_BROADCAST) && 949 !sock_flag(sk, SOCK_BROADCAST)) 950 goto out; 951 if (connected) 952 sk_dst_set(sk, dst_clone(&rt->dst)); 953 } 954 955 if (msg->msg_flags&MSG_CONFIRM) 956 goto do_confirm; 957 back_from_confirm: 958 959 saddr = fl4->saddr; 960 if (!ipc.addr) 961 daddr = ipc.addr = fl4->daddr; 962 963 /* Lockless fast path for the non-corking case. */ 964 if (!corkreq) { 965 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen, 966 sizeof(struct udphdr), &ipc, &rt, 967 msg->msg_flags); 968 err = PTR_ERR(skb); 969 if (skb && !IS_ERR(skb)) 970 err = udp_send_skb(skb, fl4); 971 goto out; 972 } 973 974 lock_sock(sk); 975 if (unlikely(up->pending)) { 976 /* The socket is already corked while preparing it. */ 977 /* ... which is an evident application bug. --ANK */ 978 release_sock(sk); 979 980 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n")); 981 err = -EINVAL; 982 goto out; 983 } 984 /* 985 * Now cork the socket to pend data. 986 */ 987 fl4 = &inet->cork.fl.u.ip4; 988 fl4->daddr = daddr; 989 fl4->saddr = saddr; 990 fl4->fl4_dport = dport; 991 fl4->fl4_sport = inet->inet_sport; 992 up->pending = AF_INET; 993 994 do_append_data: 995 up->len += ulen; 996 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen, 997 sizeof(struct udphdr), &ipc, &rt, 998 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 999 if (err) 1000 udp_flush_pending_frames(sk); 1001 else if (!corkreq) 1002 err = udp_push_pending_frames(sk); 1003 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1004 up->pending = 0; 1005 release_sock(sk); 1006 1007 out: 1008 ip_rt_put(rt); 1009 if (free) 1010 kfree(ipc.opt); 1011 if (!err) 1012 return len; 1013 /* 1014 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1015 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1016 * we don't have a good statistic (IpOutDiscards but it can be too many 1017 * things). We could add another new stat but at least for now that 1018 * seems like overkill. 1019 */ 1020 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1021 UDP_INC_STATS_USER(sock_net(sk), 1022 UDP_MIB_SNDBUFERRORS, is_udplite); 1023 } 1024 return err; 1025 1026 do_confirm: 1027 dst_confirm(&rt->dst); 1028 if (!(msg->msg_flags&MSG_PROBE) || len) 1029 goto back_from_confirm; 1030 err = 0; 1031 goto out; 1032 } 1033 EXPORT_SYMBOL(udp_sendmsg); 1034 1035 int udp_sendpage(struct sock *sk, struct page *page, int offset, 1036 size_t size, int flags) 1037 { 1038 struct inet_sock *inet = inet_sk(sk); 1039 struct udp_sock *up = udp_sk(sk); 1040 int ret; 1041 1042 if (!up->pending) { 1043 struct msghdr msg = { .msg_flags = flags|MSG_MORE }; 1044 1045 /* Call udp_sendmsg to specify destination address which 1046 * sendpage interface can't pass. 1047 * This will succeed only when the socket is connected. 1048 */ 1049 ret = udp_sendmsg(NULL, sk, &msg, 0); 1050 if (ret < 0) 1051 return ret; 1052 } 1053 1054 lock_sock(sk); 1055 1056 if (unlikely(!up->pending)) { 1057 release_sock(sk); 1058 1059 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n")); 1060 return -EINVAL; 1061 } 1062 1063 ret = ip_append_page(sk, &inet->cork.fl.u.ip4, 1064 page, offset, size, flags); 1065 if (ret == -EOPNOTSUPP) { 1066 release_sock(sk); 1067 return sock_no_sendpage(sk->sk_socket, page, offset, 1068 size, flags); 1069 } 1070 if (ret < 0) { 1071 udp_flush_pending_frames(sk); 1072 goto out; 1073 } 1074 1075 up->len += size; 1076 if (!(up->corkflag || (flags&MSG_MORE))) 1077 ret = udp_push_pending_frames(sk); 1078 if (!ret) 1079 ret = size; 1080 out: 1081 release_sock(sk); 1082 return ret; 1083 } 1084 1085 1086 /** 1087 * first_packet_length - return length of first packet in receive queue 1088 * @sk: socket 1089 * 1090 * Drops all bad checksum frames, until a valid one is found. 1091 * Returns the length of found skb, or 0 if none is found. 1092 */ 1093 static unsigned int first_packet_length(struct sock *sk) 1094 { 1095 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue; 1096 struct sk_buff *skb; 1097 unsigned int res; 1098 1099 __skb_queue_head_init(&list_kill); 1100 1101 spin_lock_bh(&rcvq->lock); 1102 while ((skb = skb_peek(rcvq)) != NULL && 1103 udp_lib_checksum_complete(skb)) { 1104 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1105 IS_UDPLITE(sk)); 1106 atomic_inc(&sk->sk_drops); 1107 __skb_unlink(skb, rcvq); 1108 __skb_queue_tail(&list_kill, skb); 1109 } 1110 res = skb ? skb->len : 0; 1111 spin_unlock_bh(&rcvq->lock); 1112 1113 if (!skb_queue_empty(&list_kill)) { 1114 bool slow = lock_sock_fast(sk); 1115 1116 __skb_queue_purge(&list_kill); 1117 sk_mem_reclaim_partial(sk); 1118 unlock_sock_fast(sk, slow); 1119 } 1120 return res; 1121 } 1122 1123 /* 1124 * IOCTL requests applicable to the UDP protocol 1125 */ 1126 1127 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg) 1128 { 1129 switch (cmd) { 1130 case SIOCOUTQ: 1131 { 1132 int amount = sk_wmem_alloc_get(sk); 1133 1134 return put_user(amount, (int __user *)arg); 1135 } 1136 1137 case SIOCINQ: 1138 { 1139 unsigned int amount = first_packet_length(sk); 1140 1141 if (amount) 1142 /* 1143 * We will only return the amount 1144 * of this packet since that is all 1145 * that will be read. 1146 */ 1147 amount -= sizeof(struct udphdr); 1148 1149 return put_user(amount, (int __user *)arg); 1150 } 1151 1152 default: 1153 return -ENOIOCTLCMD; 1154 } 1155 1156 return 0; 1157 } 1158 EXPORT_SYMBOL(udp_ioctl); 1159 1160 /* 1161 * This should be easy, if there is something there we 1162 * return it, otherwise we block. 1163 */ 1164 1165 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 1166 size_t len, int noblock, int flags, int *addr_len) 1167 { 1168 struct inet_sock *inet = inet_sk(sk); 1169 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 1170 struct sk_buff *skb; 1171 unsigned int ulen, copied; 1172 int peeked, off = 0; 1173 int err; 1174 int is_udplite = IS_UDPLITE(sk); 1175 bool slow; 1176 1177 /* 1178 * Check any passed addresses 1179 */ 1180 if (addr_len) 1181 *addr_len = sizeof(*sin); 1182 1183 if (flags & MSG_ERRQUEUE) 1184 return ip_recv_error(sk, msg, len); 1185 1186 try_again: 1187 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), 1188 &peeked, &off, &err); 1189 if (!skb) 1190 goto out; 1191 1192 ulen = skb->len - sizeof(struct udphdr); 1193 copied = len; 1194 if (copied > ulen) 1195 copied = ulen; 1196 else if (copied < ulen) 1197 msg->msg_flags |= MSG_TRUNC; 1198 1199 /* 1200 * If checksum is needed at all, try to do it while copying the 1201 * data. If the data is truncated, or if we only want a partial 1202 * coverage checksum (UDP-Lite), do it before the copy. 1203 */ 1204 1205 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { 1206 if (udp_lib_checksum_complete(skb)) 1207 goto csum_copy_err; 1208 } 1209 1210 if (skb_csum_unnecessary(skb)) 1211 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), 1212 msg->msg_iov, copied); 1213 else { 1214 err = skb_copy_and_csum_datagram_iovec(skb, 1215 sizeof(struct udphdr), 1216 msg->msg_iov); 1217 1218 if (err == -EINVAL) 1219 goto csum_copy_err; 1220 } 1221 1222 if (err) 1223 goto out_free; 1224 1225 if (!peeked) 1226 UDP_INC_STATS_USER(sock_net(sk), 1227 UDP_MIB_INDATAGRAMS, is_udplite); 1228 1229 sock_recv_ts_and_drops(msg, sk, skb); 1230 1231 /* Copy the address. */ 1232 if (sin) { 1233 sin->sin_family = AF_INET; 1234 sin->sin_port = udp_hdr(skb)->source; 1235 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 1236 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 1237 } 1238 if (inet->cmsg_flags) 1239 ip_cmsg_recv(msg, skb); 1240 1241 err = copied; 1242 if (flags & MSG_TRUNC) 1243 err = ulen; 1244 1245 out_free: 1246 skb_free_datagram_locked(sk, skb); 1247 out: 1248 return err; 1249 1250 csum_copy_err: 1251 slow = lock_sock_fast(sk); 1252 if (!skb_kill_datagram(sk, skb, flags)) 1253 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1254 unlock_sock_fast(sk, slow); 1255 1256 if (noblock) 1257 return -EAGAIN; 1258 1259 /* starting over for a new packet */ 1260 msg->msg_flags &= ~MSG_TRUNC; 1261 goto try_again; 1262 } 1263 1264 1265 int udp_disconnect(struct sock *sk, int flags) 1266 { 1267 struct inet_sock *inet = inet_sk(sk); 1268 /* 1269 * 1003.1g - break association. 1270 */ 1271 1272 sk->sk_state = TCP_CLOSE; 1273 inet->inet_daddr = 0; 1274 inet->inet_dport = 0; 1275 sock_rps_reset_rxhash(sk); 1276 sk->sk_bound_dev_if = 0; 1277 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) 1278 inet_reset_saddr(sk); 1279 1280 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { 1281 sk->sk_prot->unhash(sk); 1282 inet->inet_sport = 0; 1283 } 1284 sk_dst_reset(sk); 1285 return 0; 1286 } 1287 EXPORT_SYMBOL(udp_disconnect); 1288 1289 void udp_lib_unhash(struct sock *sk) 1290 { 1291 if (sk_hashed(sk)) { 1292 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1293 struct udp_hslot *hslot, *hslot2; 1294 1295 hslot = udp_hashslot(udptable, sock_net(sk), 1296 udp_sk(sk)->udp_port_hash); 1297 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1298 1299 spin_lock_bh(&hslot->lock); 1300 if (sk_nulls_del_node_init_rcu(sk)) { 1301 hslot->count--; 1302 inet_sk(sk)->inet_num = 0; 1303 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 1304 1305 spin_lock(&hslot2->lock); 1306 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1307 hslot2->count--; 1308 spin_unlock(&hslot2->lock); 1309 } 1310 spin_unlock_bh(&hslot->lock); 1311 } 1312 } 1313 EXPORT_SYMBOL(udp_lib_unhash); 1314 1315 /* 1316 * inet_rcv_saddr was changed, we must rehash secondary hash 1317 */ 1318 void udp_lib_rehash(struct sock *sk, u16 newhash) 1319 { 1320 if (sk_hashed(sk)) { 1321 struct udp_table *udptable = sk->sk_prot->h.udp_table; 1322 struct udp_hslot *hslot, *hslot2, *nhslot2; 1323 1324 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); 1325 nhslot2 = udp_hashslot2(udptable, newhash); 1326 udp_sk(sk)->udp_portaddr_hash = newhash; 1327 if (hslot2 != nhslot2) { 1328 hslot = udp_hashslot(udptable, sock_net(sk), 1329 udp_sk(sk)->udp_port_hash); 1330 /* we must lock primary chain too */ 1331 spin_lock_bh(&hslot->lock); 1332 1333 spin_lock(&hslot2->lock); 1334 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); 1335 hslot2->count--; 1336 spin_unlock(&hslot2->lock); 1337 1338 spin_lock(&nhslot2->lock); 1339 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, 1340 &nhslot2->head); 1341 nhslot2->count++; 1342 spin_unlock(&nhslot2->lock); 1343 1344 spin_unlock_bh(&hslot->lock); 1345 } 1346 } 1347 } 1348 EXPORT_SYMBOL(udp_lib_rehash); 1349 1350 static void udp_v4_rehash(struct sock *sk) 1351 { 1352 u16 new_hash = udp4_portaddr_hash(sock_net(sk), 1353 inet_sk(sk)->inet_rcv_saddr, 1354 inet_sk(sk)->inet_num); 1355 udp_lib_rehash(sk, new_hash); 1356 } 1357 1358 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1359 { 1360 int rc; 1361 1362 if (inet_sk(sk)->inet_daddr) 1363 sock_rps_save_rxhash(sk, skb); 1364 1365 rc = sock_queue_rcv_skb(sk, skb); 1366 if (rc < 0) { 1367 int is_udplite = IS_UDPLITE(sk); 1368 1369 /* Note that an ENOMEM error is charged twice */ 1370 if (rc == -ENOMEM) 1371 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1372 is_udplite); 1373 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1374 kfree_skb(skb); 1375 trace_udp_fail_queue_rcv_skb(rc, sk); 1376 return -1; 1377 } 1378 1379 return 0; 1380 1381 } 1382 1383 /* returns: 1384 * -1: error 1385 * 0: success 1386 * >0: "udp encap" protocol resubmission 1387 * 1388 * Note that in the success and error cases, the skb is assumed to 1389 * have either been requeued or freed. 1390 */ 1391 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 1392 { 1393 struct udp_sock *up = udp_sk(sk); 1394 int rc; 1395 int is_udplite = IS_UDPLITE(sk); 1396 1397 /* 1398 * Charge it to the socket, dropping if the queue is full. 1399 */ 1400 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 1401 goto drop; 1402 nf_reset(skb); 1403 1404 if (up->encap_type) { 1405 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 1406 1407 /* 1408 * This is an encapsulation socket so pass the skb to 1409 * the socket's udp_encap_rcv() hook. Otherwise, just 1410 * fall through and pass this up the UDP socket. 1411 * up->encap_rcv() returns the following value: 1412 * =0 if skb was successfully passed to the encap 1413 * handler or was discarded by it. 1414 * >0 if skb should be passed on to UDP. 1415 * <0 if skb should be resubmitted as proto -N 1416 */ 1417 1418 /* if we're overly short, let UDP handle it */ 1419 encap_rcv = ACCESS_ONCE(up->encap_rcv); 1420 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) { 1421 int ret; 1422 1423 ret = encap_rcv(sk, skb); 1424 if (ret <= 0) { 1425 UDP_INC_STATS_BH(sock_net(sk), 1426 UDP_MIB_INDATAGRAMS, 1427 is_udplite); 1428 return -ret; 1429 } 1430 } 1431 1432 /* FALLTHROUGH -- it's a UDP Packet */ 1433 } 1434 1435 /* 1436 * UDP-Lite specific tests, ignored on UDP sockets 1437 */ 1438 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 1439 1440 /* 1441 * MIB statistics other than incrementing the error count are 1442 * disabled for the following two types of errors: these depend 1443 * on the application settings, not on the functioning of the 1444 * protocol stack as such. 1445 * 1446 * RFC 3828 here recommends (sec 3.3): "There should also be a 1447 * way ... to ... at least let the receiving application block 1448 * delivery of packets with coverage values less than a value 1449 * provided by the application." 1450 */ 1451 if (up->pcrlen == 0) { /* full coverage was set */ 1452 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n", 1453 UDP_SKB_CB(skb)->cscov, skb->len); 1454 goto drop; 1455 } 1456 /* The next case involves violating the min. coverage requested 1457 * by the receiver. This is subtle: if receiver wants x and x is 1458 * greater than the buffersize/MTU then receiver will complain 1459 * that it wants x while sender emits packets of smaller size y. 1460 * Therefore the above ...()->partial_cov statement is essential. 1461 */ 1462 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 1463 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n", 1464 UDP_SKB_CB(skb)->cscov, up->pcrlen); 1465 goto drop; 1466 } 1467 } 1468 1469 if (rcu_access_pointer(sk->sk_filter) && 1470 udp_lib_checksum_complete(skb)) 1471 goto drop; 1472 1473 1474 if (sk_rcvqueues_full(sk, skb)) 1475 goto drop; 1476 1477 rc = 0; 1478 1479 ipv4_pktinfo_prepare(skb); 1480 bh_lock_sock(sk); 1481 if (!sock_owned_by_user(sk)) 1482 rc = __udp_queue_rcv_skb(sk, skb); 1483 else if (sk_add_backlog(sk, skb)) { 1484 bh_unlock_sock(sk); 1485 goto drop; 1486 } 1487 bh_unlock_sock(sk); 1488 1489 return rc; 1490 1491 drop: 1492 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 1493 atomic_inc(&sk->sk_drops); 1494 kfree_skb(skb); 1495 return -1; 1496 } 1497 1498 1499 static void flush_stack(struct sock **stack, unsigned int count, 1500 struct sk_buff *skb, unsigned int final) 1501 { 1502 unsigned int i; 1503 struct sk_buff *skb1 = NULL; 1504 struct sock *sk; 1505 1506 for (i = 0; i < count; i++) { 1507 sk = stack[i]; 1508 if (likely(skb1 == NULL)) 1509 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC); 1510 1511 if (!skb1) { 1512 atomic_inc(&sk->sk_drops); 1513 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS, 1514 IS_UDPLITE(sk)); 1515 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, 1516 IS_UDPLITE(sk)); 1517 } 1518 1519 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0) 1520 skb1 = NULL; 1521 } 1522 if (unlikely(skb1)) 1523 kfree_skb(skb1); 1524 } 1525 1526 /* 1527 * Multicasts and broadcasts go to each listener. 1528 * 1529 * Note: called only from the BH handler context. 1530 */ 1531 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 1532 struct udphdr *uh, 1533 __be32 saddr, __be32 daddr, 1534 struct udp_table *udptable) 1535 { 1536 struct sock *sk, *stack[256 / sizeof(struct sock *)]; 1537 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest)); 1538 int dif; 1539 unsigned int i, count = 0; 1540 1541 spin_lock(&hslot->lock); 1542 sk = sk_nulls_head(&hslot->head); 1543 dif = skb->dev->ifindex; 1544 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif); 1545 while (sk) { 1546 stack[count++] = sk; 1547 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest, 1548 daddr, uh->source, saddr, dif); 1549 if (unlikely(count == ARRAY_SIZE(stack))) { 1550 if (!sk) 1551 break; 1552 flush_stack(stack, count, skb, ~0); 1553 count = 0; 1554 } 1555 } 1556 /* 1557 * before releasing chain lock, we must take a reference on sockets 1558 */ 1559 for (i = 0; i < count; i++) 1560 sock_hold(stack[i]); 1561 1562 spin_unlock(&hslot->lock); 1563 1564 /* 1565 * do the slow work with no lock held 1566 */ 1567 if (count) { 1568 flush_stack(stack, count, skb, count - 1); 1569 1570 for (i = 0; i < count; i++) 1571 sock_put(stack[i]); 1572 } else { 1573 kfree_skb(skb); 1574 } 1575 return 0; 1576 } 1577 1578 /* Initialize UDP checksum. If exited with zero value (success), 1579 * CHECKSUM_UNNECESSARY means, that no more checks are required. 1580 * Otherwise, csum completion requires chacksumming packet body, 1581 * including udp header and folding it to skb->csum. 1582 */ 1583 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, 1584 int proto) 1585 { 1586 const struct iphdr *iph; 1587 int err; 1588 1589 UDP_SKB_CB(skb)->partial_cov = 0; 1590 UDP_SKB_CB(skb)->cscov = skb->len; 1591 1592 if (proto == IPPROTO_UDPLITE) { 1593 err = udplite_checksum_init(skb, uh); 1594 if (err) 1595 return err; 1596 } 1597 1598 iph = ip_hdr(skb); 1599 if (uh->check == 0) { 1600 skb->ip_summed = CHECKSUM_UNNECESSARY; 1601 } else if (skb->ip_summed == CHECKSUM_COMPLETE) { 1602 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 1603 proto, skb->csum)) 1604 skb->ip_summed = CHECKSUM_UNNECESSARY; 1605 } 1606 if (!skb_csum_unnecessary(skb)) 1607 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, 1608 skb->len, proto, 0); 1609 /* Probably, we should checksum udp header (it should be in cache 1610 * in any case) and data in tiny packets (< rx copybreak). 1611 */ 1612 1613 return 0; 1614 } 1615 1616 /* 1617 * All we need to do is get the socket, and then do a checksum. 1618 */ 1619 1620 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 1621 int proto) 1622 { 1623 struct sock *sk; 1624 struct udphdr *uh; 1625 unsigned short ulen; 1626 struct rtable *rt = skb_rtable(skb); 1627 __be32 saddr, daddr; 1628 struct net *net = dev_net(skb->dev); 1629 1630 /* 1631 * Validate the packet. 1632 */ 1633 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 1634 goto drop; /* No space for header. */ 1635 1636 uh = udp_hdr(skb); 1637 ulen = ntohs(uh->len); 1638 saddr = ip_hdr(skb)->saddr; 1639 daddr = ip_hdr(skb)->daddr; 1640 1641 if (ulen > skb->len) 1642 goto short_packet; 1643 1644 if (proto == IPPROTO_UDP) { 1645 /* UDP validates ulen. */ 1646 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) 1647 goto short_packet; 1648 uh = udp_hdr(skb); 1649 } 1650 1651 if (udp4_csum_init(skb, uh, proto)) 1652 goto csum_error; 1653 1654 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) 1655 return __udp4_lib_mcast_deliver(net, skb, uh, 1656 saddr, daddr, udptable); 1657 1658 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 1659 1660 if (sk != NULL) { 1661 int ret = udp_queue_rcv_skb(sk, skb); 1662 sock_put(sk); 1663 1664 /* a return value > 0 means to resubmit the input, but 1665 * it wants the return to be -protocol, or 0 1666 */ 1667 if (ret > 0) 1668 return -ret; 1669 return 0; 1670 } 1671 1672 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 1673 goto drop; 1674 nf_reset(skb); 1675 1676 /* No socket. Drop packet silently, if checksum is wrong */ 1677 if (udp_lib_checksum_complete(skb)) 1678 goto csum_error; 1679 1680 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 1681 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 1682 1683 /* 1684 * Hmm. We got an UDP packet to a port to which we 1685 * don't wanna listen. Ignore it. 1686 */ 1687 kfree_skb(skb); 1688 return 0; 1689 1690 short_packet: 1691 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n", 1692 proto == IPPROTO_UDPLITE ? "Lite" : "", 1693 &saddr, ntohs(uh->source), 1694 ulen, skb->len, 1695 &daddr, ntohs(uh->dest)); 1696 goto drop; 1697 1698 csum_error: 1699 /* 1700 * RFC1122: OK. Discards the bad packet silently (as far as 1701 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 1702 */ 1703 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n", 1704 proto == IPPROTO_UDPLITE ? "Lite" : "", 1705 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest), 1706 ulen); 1707 drop: 1708 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1709 kfree_skb(skb); 1710 return 0; 1711 } 1712 1713 int udp_rcv(struct sk_buff *skb) 1714 { 1715 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP); 1716 } 1717 1718 void udp_destroy_sock(struct sock *sk) 1719 { 1720 bool slow = lock_sock_fast(sk); 1721 udp_flush_pending_frames(sk); 1722 unlock_sock_fast(sk, slow); 1723 } 1724 1725 /* 1726 * Socket option code for UDP 1727 */ 1728 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 1729 char __user *optval, unsigned int optlen, 1730 int (*push_pending_frames)(struct sock *)) 1731 { 1732 struct udp_sock *up = udp_sk(sk); 1733 int val; 1734 int err = 0; 1735 int is_udplite = IS_UDPLITE(sk); 1736 1737 if (optlen < sizeof(int)) 1738 return -EINVAL; 1739 1740 if (get_user(val, (int __user *)optval)) 1741 return -EFAULT; 1742 1743 switch (optname) { 1744 case UDP_CORK: 1745 if (val != 0) { 1746 up->corkflag = 1; 1747 } else { 1748 up->corkflag = 0; 1749 lock_sock(sk); 1750 (*push_pending_frames)(sk); 1751 release_sock(sk); 1752 } 1753 break; 1754 1755 case UDP_ENCAP: 1756 switch (val) { 1757 case 0: 1758 case UDP_ENCAP_ESPINUDP: 1759 case UDP_ENCAP_ESPINUDP_NON_IKE: 1760 up->encap_rcv = xfrm4_udp_encap_rcv; 1761 /* FALLTHROUGH */ 1762 case UDP_ENCAP_L2TPINUDP: 1763 up->encap_type = val; 1764 break; 1765 default: 1766 err = -ENOPROTOOPT; 1767 break; 1768 } 1769 break; 1770 1771 /* 1772 * UDP-Lite's partial checksum coverage (RFC 3828). 1773 */ 1774 /* The sender sets actual checksum coverage length via this option. 1775 * The case coverage > packet length is handled by send module. */ 1776 case UDPLITE_SEND_CSCOV: 1777 if (!is_udplite) /* Disable the option on UDP sockets */ 1778 return -ENOPROTOOPT; 1779 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */ 1780 val = 8; 1781 else if (val > USHRT_MAX) 1782 val = USHRT_MAX; 1783 up->pcslen = val; 1784 up->pcflag |= UDPLITE_SEND_CC; 1785 break; 1786 1787 /* The receiver specifies a minimum checksum coverage value. To make 1788 * sense, this should be set to at least 8 (as done below). If zero is 1789 * used, this again means full checksum coverage. */ 1790 case UDPLITE_RECV_CSCOV: 1791 if (!is_udplite) /* Disable the option on UDP sockets */ 1792 return -ENOPROTOOPT; 1793 if (val != 0 && val < 8) /* Avoid silly minimal values. */ 1794 val = 8; 1795 else if (val > USHRT_MAX) 1796 val = USHRT_MAX; 1797 up->pcrlen = val; 1798 up->pcflag |= UDPLITE_RECV_CC; 1799 break; 1800 1801 default: 1802 err = -ENOPROTOOPT; 1803 break; 1804 } 1805 1806 return err; 1807 } 1808 EXPORT_SYMBOL(udp_lib_setsockopt); 1809 1810 int udp_setsockopt(struct sock *sk, int level, int optname, 1811 char __user *optval, unsigned int optlen) 1812 { 1813 if (level == SOL_UDP || level == SOL_UDPLITE) 1814 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1815 udp_push_pending_frames); 1816 return ip_setsockopt(sk, level, optname, optval, optlen); 1817 } 1818 1819 #ifdef CONFIG_COMPAT 1820 int compat_udp_setsockopt(struct sock *sk, int level, int optname, 1821 char __user *optval, unsigned int optlen) 1822 { 1823 if (level == SOL_UDP || level == SOL_UDPLITE) 1824 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1825 udp_push_pending_frames); 1826 return compat_ip_setsockopt(sk, level, optname, optval, optlen); 1827 } 1828 #endif 1829 1830 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 1831 char __user *optval, int __user *optlen) 1832 { 1833 struct udp_sock *up = udp_sk(sk); 1834 int val, len; 1835 1836 if (get_user(len, optlen)) 1837 return -EFAULT; 1838 1839 len = min_t(unsigned int, len, sizeof(int)); 1840 1841 if (len < 0) 1842 return -EINVAL; 1843 1844 switch (optname) { 1845 case UDP_CORK: 1846 val = up->corkflag; 1847 break; 1848 1849 case UDP_ENCAP: 1850 val = up->encap_type; 1851 break; 1852 1853 /* The following two cannot be changed on UDP sockets, the return is 1854 * always 0 (which corresponds to the full checksum coverage of UDP). */ 1855 case UDPLITE_SEND_CSCOV: 1856 val = up->pcslen; 1857 break; 1858 1859 case UDPLITE_RECV_CSCOV: 1860 val = up->pcrlen; 1861 break; 1862 1863 default: 1864 return -ENOPROTOOPT; 1865 } 1866 1867 if (put_user(len, optlen)) 1868 return -EFAULT; 1869 if (copy_to_user(optval, &val, len)) 1870 return -EFAULT; 1871 return 0; 1872 } 1873 EXPORT_SYMBOL(udp_lib_getsockopt); 1874 1875 int udp_getsockopt(struct sock *sk, int level, int optname, 1876 char __user *optval, int __user *optlen) 1877 { 1878 if (level == SOL_UDP || level == SOL_UDPLITE) 1879 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1880 return ip_getsockopt(sk, level, optname, optval, optlen); 1881 } 1882 1883 #ifdef CONFIG_COMPAT 1884 int compat_udp_getsockopt(struct sock *sk, int level, int optname, 1885 char __user *optval, int __user *optlen) 1886 { 1887 if (level == SOL_UDP || level == SOL_UDPLITE) 1888 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1889 return compat_ip_getsockopt(sk, level, optname, optval, optlen); 1890 } 1891 #endif 1892 /** 1893 * udp_poll - wait for a UDP event. 1894 * @file - file struct 1895 * @sock - socket 1896 * @wait - poll table 1897 * 1898 * This is same as datagram poll, except for the special case of 1899 * blocking sockets. If application is using a blocking fd 1900 * and a packet with checksum error is in the queue; 1901 * then it could get return from select indicating data available 1902 * but then block when reading it. Add special case code 1903 * to work around these arguably broken applications. 1904 */ 1905 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait) 1906 { 1907 unsigned int mask = datagram_poll(file, sock, wait); 1908 struct sock *sk = sock->sk; 1909 1910 /* Check for false positives due to checksum errors */ 1911 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) && 1912 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk)) 1913 mask &= ~(POLLIN | POLLRDNORM); 1914 1915 return mask; 1916 1917 } 1918 EXPORT_SYMBOL(udp_poll); 1919 1920 struct proto udp_prot = { 1921 .name = "UDP", 1922 .owner = THIS_MODULE, 1923 .close = udp_lib_close, 1924 .connect = ip4_datagram_connect, 1925 .disconnect = udp_disconnect, 1926 .ioctl = udp_ioctl, 1927 .destroy = udp_destroy_sock, 1928 .setsockopt = udp_setsockopt, 1929 .getsockopt = udp_getsockopt, 1930 .sendmsg = udp_sendmsg, 1931 .recvmsg = udp_recvmsg, 1932 .sendpage = udp_sendpage, 1933 .backlog_rcv = __udp_queue_rcv_skb, 1934 .hash = udp_lib_hash, 1935 .unhash = udp_lib_unhash, 1936 .rehash = udp_v4_rehash, 1937 .get_port = udp_v4_get_port, 1938 .memory_allocated = &udp_memory_allocated, 1939 .sysctl_mem = sysctl_udp_mem, 1940 .sysctl_wmem = &sysctl_udp_wmem_min, 1941 .sysctl_rmem = &sysctl_udp_rmem_min, 1942 .obj_size = sizeof(struct udp_sock), 1943 .slab_flags = SLAB_DESTROY_BY_RCU, 1944 .h.udp_table = &udp_table, 1945 #ifdef CONFIG_COMPAT 1946 .compat_setsockopt = compat_udp_setsockopt, 1947 .compat_getsockopt = compat_udp_getsockopt, 1948 #endif 1949 .clear_sk = sk_prot_clear_portaddr_nulls, 1950 }; 1951 EXPORT_SYMBOL(udp_prot); 1952 1953 /* ------------------------------------------------------------------------ */ 1954 #ifdef CONFIG_PROC_FS 1955 1956 static struct sock *udp_get_first(struct seq_file *seq, int start) 1957 { 1958 struct sock *sk; 1959 struct udp_iter_state *state = seq->private; 1960 struct net *net = seq_file_net(seq); 1961 1962 for (state->bucket = start; state->bucket <= state->udp_table->mask; 1963 ++state->bucket) { 1964 struct hlist_nulls_node *node; 1965 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; 1966 1967 if (hlist_nulls_empty(&hslot->head)) 1968 continue; 1969 1970 spin_lock_bh(&hslot->lock); 1971 sk_nulls_for_each(sk, node, &hslot->head) { 1972 if (!net_eq(sock_net(sk), net)) 1973 continue; 1974 if (sk->sk_family == state->family) 1975 goto found; 1976 } 1977 spin_unlock_bh(&hslot->lock); 1978 } 1979 sk = NULL; 1980 found: 1981 return sk; 1982 } 1983 1984 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk) 1985 { 1986 struct udp_iter_state *state = seq->private; 1987 struct net *net = seq_file_net(seq); 1988 1989 do { 1990 sk = sk_nulls_next(sk); 1991 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); 1992 1993 if (!sk) { 1994 if (state->bucket <= state->udp_table->mask) 1995 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 1996 return udp_get_first(seq, state->bucket + 1); 1997 } 1998 return sk; 1999 } 2000 2001 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos) 2002 { 2003 struct sock *sk = udp_get_first(seq, 0); 2004 2005 if (sk) 2006 while (pos && (sk = udp_get_next(seq, sk)) != NULL) 2007 --pos; 2008 return pos ? NULL : sk; 2009 } 2010 2011 static void *udp_seq_start(struct seq_file *seq, loff_t *pos) 2012 { 2013 struct udp_iter_state *state = seq->private; 2014 state->bucket = MAX_UDP_PORTS; 2015 2016 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 2017 } 2018 2019 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2020 { 2021 struct sock *sk; 2022 2023 if (v == SEQ_START_TOKEN) 2024 sk = udp_get_idx(seq, 0); 2025 else 2026 sk = udp_get_next(seq, v); 2027 2028 ++*pos; 2029 return sk; 2030 } 2031 2032 static void udp_seq_stop(struct seq_file *seq, void *v) 2033 { 2034 struct udp_iter_state *state = seq->private; 2035 2036 if (state->bucket <= state->udp_table->mask) 2037 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock); 2038 } 2039 2040 int udp_seq_open(struct inode *inode, struct file *file) 2041 { 2042 struct udp_seq_afinfo *afinfo = PDE(inode)->data; 2043 struct udp_iter_state *s; 2044 int err; 2045 2046 err = seq_open_net(inode, file, &afinfo->seq_ops, 2047 sizeof(struct udp_iter_state)); 2048 if (err < 0) 2049 return err; 2050 2051 s = ((struct seq_file *)file->private_data)->private; 2052 s->family = afinfo->family; 2053 s->udp_table = afinfo->udp_table; 2054 return err; 2055 } 2056 EXPORT_SYMBOL(udp_seq_open); 2057 2058 /* ------------------------------------------------------------------------ */ 2059 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) 2060 { 2061 struct proc_dir_entry *p; 2062 int rc = 0; 2063 2064 afinfo->seq_ops.start = udp_seq_start; 2065 afinfo->seq_ops.next = udp_seq_next; 2066 afinfo->seq_ops.stop = udp_seq_stop; 2067 2068 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 2069 afinfo->seq_fops, afinfo); 2070 if (!p) 2071 rc = -ENOMEM; 2072 return rc; 2073 } 2074 EXPORT_SYMBOL(udp_proc_register); 2075 2076 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo) 2077 { 2078 proc_net_remove(net, afinfo->name); 2079 } 2080 EXPORT_SYMBOL(udp_proc_unregister); 2081 2082 /* ------------------------------------------------------------------------ */ 2083 static void udp4_format_sock(struct sock *sp, struct seq_file *f, 2084 int bucket, int *len) 2085 { 2086 struct inet_sock *inet = inet_sk(sp); 2087 __be32 dest = inet->inet_daddr; 2088 __be32 src = inet->inet_rcv_saddr; 2089 __u16 destp = ntohs(inet->inet_dport); 2090 __u16 srcp = ntohs(inet->inet_sport); 2091 2092 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 2093 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n", 2094 bucket, src, srcp, dest, destp, sp->sk_state, 2095 sk_wmem_alloc_get(sp), 2096 sk_rmem_alloc_get(sp), 2097 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), 2098 atomic_read(&sp->sk_refcnt), sp, 2099 atomic_read(&sp->sk_drops), len); 2100 } 2101 2102 int udp4_seq_show(struct seq_file *seq, void *v) 2103 { 2104 if (v == SEQ_START_TOKEN) 2105 seq_printf(seq, "%-127s\n", 2106 " sl local_address rem_address st tx_queue " 2107 "rx_queue tr tm->when retrnsmt uid timeout " 2108 "inode ref pointer drops"); 2109 else { 2110 struct udp_iter_state *state = seq->private; 2111 int len; 2112 2113 udp4_format_sock(v, seq, state->bucket, &len); 2114 seq_printf(seq, "%*s\n", 127 - len, ""); 2115 } 2116 return 0; 2117 } 2118 2119 static const struct file_operations udp_afinfo_seq_fops = { 2120 .owner = THIS_MODULE, 2121 .open = udp_seq_open, 2122 .read = seq_read, 2123 .llseek = seq_lseek, 2124 .release = seq_release_net 2125 }; 2126 2127 /* ------------------------------------------------------------------------ */ 2128 static struct udp_seq_afinfo udp4_seq_afinfo = { 2129 .name = "udp", 2130 .family = AF_INET, 2131 .udp_table = &udp_table, 2132 .seq_fops = &udp_afinfo_seq_fops, 2133 .seq_ops = { 2134 .show = udp4_seq_show, 2135 }, 2136 }; 2137 2138 static int __net_init udp4_proc_init_net(struct net *net) 2139 { 2140 return udp_proc_register(net, &udp4_seq_afinfo); 2141 } 2142 2143 static void __net_exit udp4_proc_exit_net(struct net *net) 2144 { 2145 udp_proc_unregister(net, &udp4_seq_afinfo); 2146 } 2147 2148 static struct pernet_operations udp4_net_ops = { 2149 .init = udp4_proc_init_net, 2150 .exit = udp4_proc_exit_net, 2151 }; 2152 2153 int __init udp4_proc_init(void) 2154 { 2155 return register_pernet_subsys(&udp4_net_ops); 2156 } 2157 2158 void udp4_proc_exit(void) 2159 { 2160 unregister_pernet_subsys(&udp4_net_ops); 2161 } 2162 #endif /* CONFIG_PROC_FS */ 2163 2164 static __initdata unsigned long uhash_entries; 2165 static int __init set_uhash_entries(char *str) 2166 { 2167 if (!str) 2168 return 0; 2169 uhash_entries = simple_strtoul(str, &str, 0); 2170 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN) 2171 uhash_entries = UDP_HTABLE_SIZE_MIN; 2172 return 1; 2173 } 2174 __setup("uhash_entries=", set_uhash_entries); 2175 2176 void __init udp_table_init(struct udp_table *table, const char *name) 2177 { 2178 unsigned int i; 2179 2180 if (!CONFIG_BASE_SMALL) 2181 table->hash = alloc_large_system_hash(name, 2182 2 * sizeof(struct udp_hslot), 2183 uhash_entries, 2184 21, /* one slot per 2 MB */ 2185 0, 2186 &table->log, 2187 &table->mask, 2188 64 * 1024); 2189 /* 2190 * Make sure hash table has the minimum size 2191 */ 2192 if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) { 2193 table->hash = kmalloc(UDP_HTABLE_SIZE_MIN * 2194 2 * sizeof(struct udp_hslot), GFP_KERNEL); 2195 if (!table->hash) 2196 panic(name); 2197 table->log = ilog2(UDP_HTABLE_SIZE_MIN); 2198 table->mask = UDP_HTABLE_SIZE_MIN - 1; 2199 } 2200 table->hash2 = table->hash + (table->mask + 1); 2201 for (i = 0; i <= table->mask; i++) { 2202 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); 2203 table->hash[i].count = 0; 2204 spin_lock_init(&table->hash[i].lock); 2205 } 2206 for (i = 0; i <= table->mask; i++) { 2207 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); 2208 table->hash2[i].count = 0; 2209 spin_lock_init(&table->hash2[i].lock); 2210 } 2211 } 2212 2213 void __init udp_init(void) 2214 { 2215 unsigned long limit; 2216 2217 udp_table_init(&udp_table, "UDP"); 2218 limit = nr_free_buffer_pages() / 8; 2219 limit = max(limit, 128UL); 2220 sysctl_udp_mem[0] = limit / 4 * 3; 2221 sysctl_udp_mem[1] = limit; 2222 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; 2223 2224 sysctl_udp_rmem_min = SK_MEM_QUANTUM; 2225 sysctl_udp_wmem_min = SK_MEM_QUANTUM; 2226 } 2227 2228 int udp4_ufo_send_check(struct sk_buff *skb) 2229 { 2230 const struct iphdr *iph; 2231 struct udphdr *uh; 2232 2233 if (!pskb_may_pull(skb, sizeof(*uh))) 2234 return -EINVAL; 2235 2236 iph = ip_hdr(skb); 2237 uh = udp_hdr(skb); 2238 2239 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, 2240 IPPROTO_UDP, 0); 2241 skb->csum_start = skb_transport_header(skb) - skb->head; 2242 skb->csum_offset = offsetof(struct udphdr, check); 2243 skb->ip_summed = CHECKSUM_PARTIAL; 2244 return 0; 2245 } 2246 2247 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 2248 netdev_features_t features) 2249 { 2250 struct sk_buff *segs = ERR_PTR(-EINVAL); 2251 unsigned int mss; 2252 int offset; 2253 __wsum csum; 2254 2255 mss = skb_shinfo(skb)->gso_size; 2256 if (unlikely(skb->len <= mss)) 2257 goto out; 2258 2259 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { 2260 /* Packet is from an untrusted source, reset gso_segs. */ 2261 int type = skb_shinfo(skb)->gso_type; 2262 2263 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) || 2264 !(type & (SKB_GSO_UDP)))) 2265 goto out; 2266 2267 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); 2268 2269 segs = NULL; 2270 goto out; 2271 } 2272 2273 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot 2274 * do checksum of UDP packets sent as multiple IP fragments. 2275 */ 2276 offset = skb_checksum_start_offset(skb); 2277 csum = skb_checksum(skb, offset, skb->len - offset, 0); 2278 offset += skb->csum_offset; 2279 *(__sum16 *)(skb->data + offset) = csum_fold(csum); 2280 skb->ip_summed = CHECKSUM_NONE; 2281 2282 /* Fragment the skb. IP headers of the fragments are updated in 2283 * inet_gso_segment() 2284 */ 2285 segs = skb_segment(skb, features); 2286 out: 2287 return segs; 2288 } 2289 2290