protocol.c 42.8 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611
/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001 Intel Corp.
 * Copyright (c) 2001 Nokia, Inc.
 * Copyright (c) 2001 La Monte H.P. Yarroll
 *
 * This file is part of the SCTP kernel implementation
 *
 * Initialization/cleanup for SCTP protocol support.
 *
 * This SCTP implementation is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This SCTP implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson <karl@athena.chicago.il.us>
 *    Jon Grimm <jgrimm@us.ibm.com>
 *    Sridhar Samudrala <sri@us.ibm.com>
 *    Daisy Chang <daisyc@us.ibm.com>
 *    Ardelle Fan <ardelle.fan@intel.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/seq_file.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/swap.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/protocol.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/route.h>
#include <net/sctp/sctp.h>
#include <net/addrconf.h>
#include <net/inet_common.h>
#include <net/inet_ecn.h>

#define MAX_SCTP_PORT_HASH_ENTRIES (64 * 1024)

/* Global data structures. */
struct sctp_globals sctp_globals __read_mostly;

struct idr sctp_assocs_id;
DEFINE_SPINLOCK(sctp_assocs_id_lock);

static struct sctp_pf *sctp_pf_inet6_specific;
static struct sctp_pf *sctp_pf_inet_specific;
static struct sctp_af *sctp_af_v4_specific;
static struct sctp_af *sctp_af_v6_specific;

struct kmem_cache *sctp_chunk_cachep __read_mostly;
struct kmem_cache *sctp_bucket_cachep __read_mostly;

long sysctl_sctp_mem[3];
int sysctl_sctp_rmem[3];
int sysctl_sctp_wmem[3];

/* Set up the proc fs entry for the SCTP protocol. */
static int __net_init sctp_proc_init(struct net *net)
{
#ifdef CONFIG_PROC_FS
	net->sctp.proc_net_sctp = proc_net_mkdir(net, "sctp", net->proc_net);
	if (!net->sctp.proc_net_sctp)
		goto out_proc_net_sctp;
	if (sctp_snmp_proc_init(net))
		goto out_snmp_proc_init;
	if (sctp_eps_proc_init(net))
		goto out_eps_proc_init;
	if (sctp_assocs_proc_init(net))
		goto out_assocs_proc_init;
	if (sctp_remaddr_proc_init(net))
		goto out_remaddr_proc_init;

	return 0;

out_remaddr_proc_init:
	sctp_assocs_proc_exit(net);
out_assocs_proc_init:
	sctp_eps_proc_exit(net);
out_eps_proc_init:
	sctp_snmp_proc_exit(net);
out_snmp_proc_init:
	remove_proc_entry("sctp", net->proc_net);
	net->sctp.proc_net_sctp = NULL;
out_proc_net_sctp:
	return -ENOMEM;
#endif /* CONFIG_PROC_FS */
	return 0;
}

/* Clean up the proc fs entry for the SCTP protocol.
 * Note: Do not make this __exit as it is used in the init error
 * path.
 */
static void sctp_proc_exit(struct net *net)
{
#ifdef CONFIG_PROC_FS
	sctp_snmp_proc_exit(net);
	sctp_eps_proc_exit(net);
	sctp_assocs_proc_exit(net);
	sctp_remaddr_proc_exit(net);

	remove_proc_entry("sctp", net->proc_net);
	net->sctp.proc_net_sctp = NULL;
#endif
}

/* Private helper to extract ipv4 address and stash them in
 * the protocol structure.
 */
static void sctp_v4_copy_addrlist(struct list_head *addrlist,
				  struct net_device *dev)
{
	struct in_device *in_dev;
	struct in_ifaddr *ifa;
	struct sctp_sockaddr_entry *addr;

	rcu_read_lock();
	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
		rcu_read_unlock();
		return;
	}

	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
		/* Add the address to the local list.  */
		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
		if (addr) {
			addr->a.v4.sin_family = AF_INET;
			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
			addr->valid = 1;
			INIT_LIST_HEAD(&addr->list);
			list_add_tail(&addr->list, addrlist);
		}
	}

	rcu_read_unlock();
}

/* Extract our IP addresses from the system and stash them in the
 * protocol structure.
 */
static void sctp_get_local_addr_list(struct net *net)
{
	struct net_device *dev;
	struct list_head *pos;
	struct sctp_af *af;

	rcu_read_lock();
	for_each_netdev_rcu(net, dev) {
		list_for_each(pos, &sctp_address_families) {
			af = list_entry(pos, struct sctp_af, list);
			af->copy_addrlist(&net->sctp.local_addr_list, dev);
		}
	}
	rcu_read_unlock();
}

/* Free the existing local addresses.  */
static void sctp_free_local_addr_list(struct net *net)
{
	struct sctp_sockaddr_entry *addr;
	struct list_head *pos, *temp;

	list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
		list_del(pos);
		kfree(addr);
	}
}

/* Copy the local addresses which are valid for 'scope' into 'bp'.  */
int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
			      enum sctp_scope scope, gfp_t gfp, int copy_flags)
{
	struct sctp_sockaddr_entry *addr;
	union sctp_addr laddr;
	int error = 0;

	rcu_read_lock();
	list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
		if (!addr->valid)
			continue;
		if (!sctp_in_scope(net, &addr->a, scope))
			continue;

		/* Now that the address is in scope, check to see if
		 * the address type is really supported by the local
		 * sock as well as the remote peer.
		 */
		if (addr->a.sa.sa_family == AF_INET &&
		    !(copy_flags & SCTP_ADDR4_PEERSUPP))
			continue;
		if (addr->a.sa.sa_family == AF_INET6 &&
		    (!(copy_flags & SCTP_ADDR6_ALLOWED) ||
		     !(copy_flags & SCTP_ADDR6_PEERSUPP)))
			continue;

		laddr = addr->a;
		/* also works for setting ipv6 address port */
		laddr.v4.sin_port = htons(bp->port);
		if (sctp_bind_addr_state(bp, &laddr) != -1)
			continue;

		error = sctp_add_bind_addr(bp, &addr->a, sizeof(addr->a),
					   SCTP_ADDR_SRC, GFP_ATOMIC);
		if (error)
			break;
	}

	rcu_read_unlock();
	return error;
}

/* Initialize a sctp_addr from in incoming skb.  */
static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
			     int is_saddr)
{
	/* Always called on head skb, so this is safe */
	struct sctphdr *sh = sctp_hdr(skb);
	struct sockaddr_in *sa = &addr->v4;

	addr->v4.sin_family = AF_INET;

	if (is_saddr) {
		sa->sin_port = sh->source;
		sa->sin_addr.s_addr = ip_hdr(skb)->saddr;
	} else {
		sa->sin_port = sh->dest;
		sa->sin_addr.s_addr = ip_hdr(skb)->daddr;
	}
}

/* Initialize an sctp_addr from a socket. */
static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
{
	addr->v4.sin_family = AF_INET;
	addr->v4.sin_port = 0;
	addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
}

/* Initialize sk->sk_rcv_saddr from sctp_addr. */
static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
{
	inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
}

/* Initialize sk->sk_daddr from sctp_addr. */
static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
{
	inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
}

/* Initialize a sctp_addr from an address parameter. */
static void sctp_v4_from_addr_param(union sctp_addr *addr,
				    union sctp_addr_param *param,
				    __be16 port, int iif)
{
	addr->v4.sin_family = AF_INET;
	addr->v4.sin_port = port;
	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
}

/* Initialize an address parameter from a sctp_addr and return the length
 * of the address parameter.
 */
static int sctp_v4_to_addr_param(const union sctp_addr *addr,
				 union sctp_addr_param *param)
{
	int length = sizeof(struct sctp_ipv4addr_param);

	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
	param->v4.param_hdr.length = htons(length);
	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;

	return length;
}

/* Initialize a sctp_addr from a dst_entry. */
static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
			      __be16 port)
{
	saddr->v4.sin_family = AF_INET;
	saddr->v4.sin_port = port;
	saddr->v4.sin_addr.s_addr = fl4->saddr;
}

/* Compare two addresses exactly. */
static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
			    const union sctp_addr *addr2)
{
	if (addr1->sa.sa_family != addr2->sa.sa_family)
		return 0;
	if (addr1->v4.sin_port != addr2->v4.sin_port)
		return 0;
	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
		return 0;

	return 1;
}

/* Initialize addr struct to INADDR_ANY. */
static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
{
	addr->v4.sin_family = AF_INET;
	addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
	addr->v4.sin_port = port;
}

/* Is this a wildcard address? */
static int sctp_v4_is_any(const union sctp_addr *addr)
{
	return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
}

/* This function checks if the address is a valid address to be used for
 * SCTP binding.
 *
 * Output:
 * Return 0 - If the address is a non-unicast or an illegal address.
 * Return 1 - If the address is a unicast.
 */
static int sctp_v4_addr_valid(union sctp_addr *addr,
			      struct sctp_sock *sp,
			      const struct sk_buff *skb)
{
	/* IPv4 addresses not allowed */
	if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
		return 0;

	/* Is this a non-unicast address or a unusable SCTP address? */
	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
		return 0;

	/* Is this a broadcast address? */
	if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
		return 0;

	return 1;
}

/* Should this be available for binding?   */
static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
{
	struct net *net = sock_net(&sp->inet.sk);
	int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);


	if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
	   ret != RTN_LOCAL &&
	   !sp->inet.freebind &&
	   !net->ipv4.sysctl_ip_nonlocal_bind)
		return 0;

	if (ipv6_only_sock(sctp_opt2sk(sp)))
		return 0;

	return 1;
}

/* Checking the loopback, private and other address scopes as defined in
 * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
 * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
 *
 * Level 0 - unusable SCTP addresses
 * Level 1 - loopback address
 * Level 2 - link-local addresses
 * Level 3 - private addresses.
 * Level 4 - global addresses
 * For INIT and INIT-ACK address list, let L be the level of
 * of requested destination address, sender and receiver
 * SHOULD include all of its addresses with level greater
 * than or equal to L.
 *
 * IPv4 scoping can be controlled through sysctl option
 * net.sctp.addr_scope_policy
 */
static enum sctp_scope sctp_v4_scope(union sctp_addr *addr)
{
	enum sctp_scope retval;

	/* Check for unusable SCTP addresses. */
	if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
		retval =  SCTP_SCOPE_UNUSABLE;
	} else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
		retval = SCTP_SCOPE_LOOPBACK;
	} else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
		retval = SCTP_SCOPE_LINK;
	} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
		   ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
		   ipv4_is_private_192(addr->v4.sin_addr.s_addr)) {
		retval = SCTP_SCOPE_PRIVATE;
	} else {
		retval = SCTP_SCOPE_GLOBAL;
	}

	return retval;
}

/* Returns a valid dst cache entry for the given source and destination ip
 * addresses. If an association is passed, trys to get a dst entry with a
 * source address that matches an address in the bind address list.
 */
static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
				struct flowi *fl, struct sock *sk)
{
	struct sctp_association *asoc = t->asoc;
	struct rtable *rt;
	struct flowi4 *fl4 = &fl->u.ip4;
	struct sctp_bind_addr *bp;
	struct sctp_sockaddr_entry *laddr;
	struct dst_entry *dst = NULL;
	union sctp_addr *daddr = &t->ipaddr;
	union sctp_addr dst_saddr;

	memset(fl4, 0x0, sizeof(struct flowi4));
	fl4->daddr  = daddr->v4.sin_addr.s_addr;
	fl4->fl4_dport = daddr->v4.sin_port;
	fl4->flowi4_proto = IPPROTO_SCTP;
	if (asoc) {
		fl4->flowi4_tos = RT_CONN_FLAGS(asoc->base.sk);
		fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
		fl4->fl4_sport = htons(asoc->base.bind_addr.port);
	}
	if (saddr) {
		fl4->saddr = saddr->v4.sin_addr.s_addr;
		fl4->fl4_sport = saddr->v4.sin_port;
	}

	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
		 &fl4->saddr);

	rt = ip_route_output_key(sock_net(sk), fl4);
	if (!IS_ERR(rt))
		dst = &rt->dst;

	/* If there is no association or if a source address is passed, no
	 * more validation is required.
	 */
	if (!asoc || saddr)
		goto out;

	bp = &asoc->base.bind_addr;

	if (dst) {
		/* Walk through the bind address list and look for a bind
		 * address that matches the source address of the returned dst.
		 */
		sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
		rcu_read_lock();
		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
			if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
			    (laddr->state != SCTP_ADDR_SRC &&
			    !asoc->src_out_of_asoc_ok))
				continue;
			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
				goto out_unlock;
		}
		rcu_read_unlock();

		/* None of the bound addresses match the source address of the
		 * dst. So release it.
		 */
		dst_release(dst);
		dst = NULL;
	}

	/* Walk through the bind address list and try to get a dst that
	 * matches a bind address as the source address.
	 */
	rcu_read_lock();
	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
		struct net_device *odev;

		if (!laddr->valid)
			continue;
		if (laddr->state != SCTP_ADDR_SRC ||
		    AF_INET != laddr->a.sa.sa_family)
			continue;

		fl4->fl4_sport = laddr->a.v4.sin_port;
		flowi4_update_output(fl4,
				     asoc->base.sk->sk_bound_dev_if,
				     RT_CONN_FLAGS(asoc->base.sk),
				     daddr->v4.sin_addr.s_addr,
				     laddr->a.v4.sin_addr.s_addr);

		rt = ip_route_output_key(sock_net(sk), fl4);
		if (IS_ERR(rt))
			continue;

		/* Ensure the src address belongs to the output
		 * interface.
		 */
		odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
				     false);
		if (!odev || odev->ifindex != fl4->flowi4_oif) {
			if (!dst)
				dst = &rt->dst;
			else
				dst_release(&rt->dst);
			continue;
		}

		dst_release(dst);
		dst = &rt->dst;
		break;
	}

out_unlock:
	rcu_read_unlock();
out:
	t->dst = dst;
	if (dst)
		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
			 &fl4->daddr, &fl4->saddr);
	else
		pr_debug("no route\n");
}

/* For v4, the source address is cached in the route entry(dst). So no need
 * to cache it separately and hence this is an empty routine.
 */
static void sctp_v4_get_saddr(struct sctp_sock *sk,
			      struct sctp_transport *t,
			      struct flowi *fl)
{
	union sctp_addr *saddr = &t->saddr;
	struct rtable *rt = (struct rtable *)t->dst;

	if (rt) {
		saddr->v4.sin_family = AF_INET;
		saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
	}
}

/* What interface did this skb arrive on? */
static int sctp_v4_skb_iif(const struct sk_buff *skb)
{
	return inet_iif(skb);
}

/* Was this packet marked by Explicit Congestion Notification? */
static int sctp_v4_is_ce(const struct sk_buff *skb)
{
	return INET_ECN_is_ce(ip_hdr(skb)->tos);
}

/* Create and initialize a new sk for the socket returned by accept(). */
static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
					     struct sctp_association *asoc,
					     bool kern)
{
	struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
			sk->sk_prot, kern);
	struct inet_sock *newinet;

	if (!newsk)
		goto out;

	sock_init_data(NULL, newsk);

	sctp_copy_sock(newsk, sk, asoc);
	sock_reset_flag(newsk, SOCK_ZAPPED);

	newinet = inet_sk(newsk);

	newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;

	sk_refcnt_debug_inc(newsk);

	if (newsk->sk_prot->init(newsk)) {
		sk_common_release(newsk);
		newsk = NULL;
	}

out:
	return newsk;
}

static int sctp_v4_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
{
	/* No address mapping for V4 sockets */
	return sizeof(struct sockaddr_in);
}

/* Dump the v4 addr to the seq file. */
static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
{
	seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
}

static void sctp_v4_ecn_capable(struct sock *sk)
{
	INET_ECN_xmit(sk);
}

static void sctp_addr_wq_timeout_handler(unsigned long arg)
{
	struct net *net = (struct net *)arg;
	struct sctp_sockaddr_entry *addrw, *temp;
	struct sctp_sock *sp;

	spin_lock_bh(&net->sctp.addr_wq_lock);

	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
			 addrw->state, addrw);

#if IS_ENABLED(CONFIG_IPV6)
		/* Now we send an ASCONF for each association */
		/* Note. we currently don't handle link local IPv6 addressees */
		if (addrw->a.sa.sa_family == AF_INET6) {
			struct in6_addr *in6;

			if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
			    IPV6_ADDR_LINKLOCAL)
				goto free_next;

			in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
			if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
			    addrw->state == SCTP_ADDR_NEW) {
				unsigned long timeo_val;

				pr_debug("%s: this is on DAD, trying %d sec "
					 "later\n", __func__,
					 SCTP_ADDRESS_TICK_DELAY);

				timeo_val = jiffies;
				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
				break;
			}
		}
#endif
		list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
			struct sock *sk;

			sk = sctp_opt2sk(sp);
			/* ignore bound-specific endpoints */
			if (!sctp_is_ep_boundall(sk))
				continue;
			bh_lock_sock(sk);
			if (sctp_asconf_mgmt(sp, addrw) < 0)
				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
			bh_unlock_sock(sk);
		}
#if IS_ENABLED(CONFIG_IPV6)
free_next:
#endif
		list_del(&addrw->list);
		kfree(addrw);
	}
	spin_unlock_bh(&net->sctp.addr_wq_lock);
}

static void sctp_free_addr_wq(struct net *net)
{
	struct sctp_sockaddr_entry *addrw;
	struct sctp_sockaddr_entry *temp;

	spin_lock_bh(&net->sctp.addr_wq_lock);
	del_timer(&net->sctp.addr_wq_timer);
	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
		list_del(&addrw->list);
		kfree(addrw);
	}
	spin_unlock_bh(&net->sctp.addr_wq_lock);
}

/* lookup the entry for the same address in the addr_waitq
 * sctp_addr_wq MUST be locked
 */
static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
					struct sctp_sockaddr_entry *addr)
{
	struct sctp_sockaddr_entry *addrw;

	list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
		if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
			continue;
		if (addrw->a.sa.sa_family == AF_INET) {
			if (addrw->a.v4.sin_addr.s_addr ==
			    addr->a.v4.sin_addr.s_addr)
				return addrw;
		} else if (addrw->a.sa.sa_family == AF_INET6) {
			if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
			    &addr->a.v6.sin6_addr))
				return addrw;
		}
	}
	return NULL;
}

void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
{
	struct sctp_sockaddr_entry *addrw;
	unsigned long timeo_val;

	/* first, we check if an opposite message already exist in the queue.
	 * If we found such message, it is removed.
	 * This operation is a bit stupid, but the DHCP client attaches the
	 * new address after a couple of addition and deletion of that address
	 */

	spin_lock_bh(&net->sctp.addr_wq_lock);
	/* Offsets existing events in addr_wq */
	addrw = sctp_addr_wq_lookup(net, addr);
	if (addrw) {
		if (addrw->state != cmd) {
			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
				 &net->sctp.addr_waitq);

			list_del(&addrw->list);
			kfree(addrw);
		}
		spin_unlock_bh(&net->sctp.addr_wq_lock);
		return;
	}

	/* OK, we have to add the new address to the wait queue */
	addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
	if (addrw == NULL) {
		spin_unlock_bh(&net->sctp.addr_wq_lock);
		return;
	}
	addrw->state = cmd;
	list_add_tail(&addrw->list, &net->sctp.addr_waitq);

	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);

	if (!timer_pending(&net->sctp.addr_wq_timer)) {
		timeo_val = jiffies;
		timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
		mod_timer(&net->sctp.addr_wq_timer, timeo_val);
	}
	spin_unlock_bh(&net->sctp.addr_wq_lock);
}

/* Event handler for inet address addition/deletion events.
 * The sctp_local_addr_list needs to be protocted by a spin lock since
 * multiple notifiers (say IPv4 and IPv6) may be running at the same
 * time and thus corrupt the list.
 * The reader side is protected with RCU.
 */
static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
			       void *ptr)
{
	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
	struct sctp_sockaddr_entry *addr = NULL;
	struct sctp_sockaddr_entry *temp;
	struct net *net = dev_net(ifa->ifa_dev->dev);
	int found = 0;

	switch (ev) {
	case NETDEV_UP:
		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
		if (addr) {
			addr->a.v4.sin_family = AF_INET;
			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
			addr->valid = 1;
			spin_lock_bh(&net->sctp.local_addr_lock);
			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
			spin_unlock_bh(&net->sctp.local_addr_lock);
		}
		break;
	case NETDEV_DOWN:
		spin_lock_bh(&net->sctp.local_addr_lock);
		list_for_each_entry_safe(addr, temp,
					&net->sctp.local_addr_list, list) {
			if (addr->a.sa.sa_family == AF_INET &&
					addr->a.v4.sin_addr.s_addr ==
					ifa->ifa_local) {
				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
				found = 1;
				addr->valid = 0;
				list_del_rcu(&addr->list);
				break;
			}
		}
		spin_unlock_bh(&net->sctp.local_addr_lock);
		if (found)
			kfree_rcu(addr, rcu);
		break;
	}

	return NOTIFY_DONE;
}

/*
 * Initialize the control inode/socket with a control endpoint data
 * structure.  This endpoint is reserved exclusively for the OOTB processing.
 */
static int sctp_ctl_sock_init(struct net *net)
{
	int err;
	sa_family_t family = PF_INET;

	if (sctp_get_pf_specific(PF_INET6))
		family = PF_INET6;

	err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
				   SOCK_SEQPACKET, IPPROTO_SCTP, net);

	/* If IPv6 socket could not be created, try the IPv4 socket */
	if (err < 0 && family == PF_INET6)
		err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
					   SOCK_SEQPACKET, IPPROTO_SCTP,
					   net);

	if (err < 0) {
		pr_err("Failed to create the SCTP control socket\n");
		return err;
	}
	return 0;
}

/* Register address family specific functions. */
int sctp_register_af(struct sctp_af *af)
{
	switch (af->sa_family) {
	case AF_INET:
		if (sctp_af_v4_specific)
			return 0;
		sctp_af_v4_specific = af;
		break;
	case AF_INET6:
		if (sctp_af_v6_specific)
			return 0;
		sctp_af_v6_specific = af;
		break;
	default:
		return 0;
	}

	INIT_LIST_HEAD(&af->list);
	list_add_tail(&af->list, &sctp_address_families);
	return 1;
}

/* Get the table of functions for manipulating a particular address
 * family.
 */
struct sctp_af *sctp_get_af_specific(sa_family_t family)
{
	switch (family) {
	case AF_INET:
		return sctp_af_v4_specific;
	case AF_INET6:
		return sctp_af_v6_specific;
	default:
		return NULL;
	}
}

/* Common code to initialize a AF_INET msg_name. */
static void sctp_inet_msgname(char *msgname, int *addr_len)
{
	struct sockaddr_in *sin;

	sin = (struct sockaddr_in *)msgname;
	*addr_len = sizeof(struct sockaddr_in);
	sin->sin_family = AF_INET;
	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
}

/* Copy the primary address of the peer primary address as the msg_name. */
static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
				    int *addr_len)
{
	struct sockaddr_in *sin, *sinfrom;

	if (msgname) {
		struct sctp_association *asoc;

		asoc = event->asoc;
		sctp_inet_msgname(msgname, addr_len);
		sin = (struct sockaddr_in *)msgname;
		sinfrom = &asoc->peer.primary_addr.v4;
		sin->sin_port = htons(asoc->peer.port);
		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
	}
}

/* Initialize and copy out a msgname from an inbound skb. */
static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
{
	if (msgname) {
		struct sctphdr *sh = sctp_hdr(skb);
		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;

		sctp_inet_msgname(msgname, len);
		sin->sin_port = sh->source;
		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
	}
}

/* Do we support this AF? */
static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
{
	/* PF_INET only supports AF_INET addresses. */
	return AF_INET == family;
}

/* Address matching with wildcards allowed. */
static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
			      const union sctp_addr *addr2,
			      struct sctp_sock *opt)
{
	/* PF_INET only supports AF_INET addresses. */
	if (addr1->sa.sa_family != addr2->sa.sa_family)
		return 0;
	if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
	    htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
		return 1;
	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
		return 1;

	return 0;
}

/* Verify that provided sockaddr looks bindable.  Common verification has
 * already been taken care of.
 */
static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
{
	return sctp_v4_available(addr, opt);
}

/* Verify that sockaddr looks sendable.  Common verification has already
 * been taken care of.
 */
static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
{
	return 1;
}

/* Fill in Supported Address Type information for INIT and INIT-ACK
 * chunks.  Returns number of addresses supported.
 */
static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
				     __be16 *types)
{
	types[0] = SCTP_PARAM_IPV4_ADDRESS;
	return 1;
}

/* Wrapper routine that calls the ip transmit routine. */
static inline int sctp_v4_xmit(struct sk_buff *skb,
			       struct sctp_transport *transport)
{
	struct inet_sock *inet = inet_sk(skb->sk);

	pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
		 skb->len, &transport->fl.u.ip4.saddr, &transport->fl.u.ip4.daddr);

	inet->pmtudisc = transport->param_flags & SPP_PMTUD_ENABLE ?
			 IP_PMTUDISC_DO : IP_PMTUDISC_DONT;

	SCTP_INC_STATS(sock_net(&inet->sk), SCTP_MIB_OUTSCTPPACKS);

	return ip_queue_xmit(&inet->sk, skb, &transport->fl);
}

static struct sctp_af sctp_af_inet;

static struct sctp_pf sctp_pf_inet = {
	.event_msgname = sctp_inet_event_msgname,
	.skb_msgname   = sctp_inet_skb_msgname,
	.af_supported  = sctp_inet_af_supported,
	.cmp_addr      = sctp_inet_cmp_addr,
	.bind_verify   = sctp_inet_bind_verify,
	.send_verify   = sctp_inet_send_verify,
	.supported_addrs = sctp_inet_supported_addrs,
	.create_accept_sk = sctp_v4_create_accept_sk,
	.addr_to_user  = sctp_v4_addr_to_user,
	.to_sk_saddr   = sctp_v4_to_sk_saddr,
	.to_sk_daddr   = sctp_v4_to_sk_daddr,
	.af            = &sctp_af_inet
};

/* Notifier for inetaddr addition/deletion events.  */
static struct notifier_block sctp_inetaddr_notifier = {
	.notifier_call = sctp_inetaddr_event,
};

/* Socket operations.  */
static const struct proto_ops inet_seqpacket_ops = {
	.family		   = PF_INET,
	.owner		   = THIS_MODULE,
	.release	   = inet_release,	/* Needs to be wrapped... */
	.bind		   = inet_bind,
	.connect	   = inet_dgram_connect,
	.socketpair	   = sock_no_socketpair,
	.accept		   = inet_accept,
	.getname	   = inet_getname,	/* Semantics are different.  */
	.poll		   = sctp_poll,
	.ioctl		   = inet_ioctl,
	.listen		   = sctp_inet_listen,
	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
	.getsockopt	   = sock_common_getsockopt,
	.sendmsg	   = inet_sendmsg,
	.recvmsg	   = inet_recvmsg,
	.mmap		   = sock_no_mmap,
	.sendpage	   = sock_no_sendpage,
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_sock_common_setsockopt,
	.compat_getsockopt = compat_sock_common_getsockopt,
#endif
};

/* Registration with AF_INET family.  */
static struct inet_protosw sctp_seqpacket_protosw = {
	.type       = SOCK_SEQPACKET,
	.protocol   = IPPROTO_SCTP,
	.prot       = &sctp_prot,
	.ops        = &inet_seqpacket_ops,
	.flags      = SCTP_PROTOSW_FLAG
};
static struct inet_protosw sctp_stream_protosw = {
	.type       = SOCK_STREAM,
	.protocol   = IPPROTO_SCTP,
	.prot       = &sctp_prot,
	.ops        = &inet_seqpacket_ops,
	.flags      = SCTP_PROTOSW_FLAG
};

/* Register with IP layer.  */
static const struct net_protocol sctp_protocol = {
	.handler     = sctp_rcv,
	.err_handler = sctp_v4_err,
	.no_policy   = 1,
	.netns_ok    = 1,
	.icmp_strict_tag_validation = 1,
};

/* IPv4 address related functions.  */
static struct sctp_af sctp_af_inet = {
	.sa_family	   = AF_INET,
	.sctp_xmit	   = sctp_v4_xmit,
	.setsockopt	   = ip_setsockopt,
	.getsockopt	   = ip_getsockopt,
	.get_dst	   = sctp_v4_get_dst,
	.get_saddr	   = sctp_v4_get_saddr,
	.copy_addrlist	   = sctp_v4_copy_addrlist,
	.from_skb	   = sctp_v4_from_skb,
	.from_sk	   = sctp_v4_from_sk,
	.from_addr_param   = sctp_v4_from_addr_param,
	.to_addr_param	   = sctp_v4_to_addr_param,
	.cmp_addr	   = sctp_v4_cmp_addr,
	.addr_valid	   = sctp_v4_addr_valid,
	.inaddr_any	   = sctp_v4_inaddr_any,
	.is_any		   = sctp_v4_is_any,
	.available	   = sctp_v4_available,
	.scope		   = sctp_v4_scope,
	.skb_iif	   = sctp_v4_skb_iif,
	.is_ce		   = sctp_v4_is_ce,
	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
	.ecn_capable	   = sctp_v4_ecn_capable,
	.net_header_len	   = sizeof(struct iphdr),
	.sockaddr_len	   = sizeof(struct sockaddr_in),
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_ip_setsockopt,
	.compat_getsockopt = compat_ip_getsockopt,
#endif
};

struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
{
	switch (family) {
	case PF_INET:
		return sctp_pf_inet_specific;
	case PF_INET6:
		return sctp_pf_inet6_specific;
	default:
		return NULL;
	}
}

/* Register the PF specific function table.  */
int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
{
	switch (family) {
	case PF_INET:
		if (sctp_pf_inet_specific)
			return 0;
		sctp_pf_inet_specific = pf;
		break;
	case PF_INET6:
		if (sctp_pf_inet6_specific)
			return 0;
		sctp_pf_inet6_specific = pf;
		break;
	default:
		return 0;
	}
	return 1;
}

static inline int init_sctp_mibs(struct net *net)
{
	net->sctp.sctp_statistics = alloc_percpu(struct sctp_mib);
	if (!net->sctp.sctp_statistics)
		return -ENOMEM;
	return 0;
}

static inline void cleanup_sctp_mibs(struct net *net)
{
	free_percpu(net->sctp.sctp_statistics);
}

static void sctp_v4_pf_init(void)
{
	/* Initialize the SCTP specific PF functions. */
	sctp_register_pf(&sctp_pf_inet, PF_INET);
	sctp_register_af(&sctp_af_inet);
}

static void sctp_v4_pf_exit(void)
{
	list_del(&sctp_af_inet.list);
}

static int sctp_v4_protosw_init(void)
{
	int rc;

	rc = proto_register(&sctp_prot, 1);
	if (rc)
		return rc;

	/* Register SCTP(UDP and TCP style) with socket layer.  */
	inet_register_protosw(&sctp_seqpacket_protosw);
	inet_register_protosw(&sctp_stream_protosw);

	return 0;
}

static void sctp_v4_protosw_exit(void)
{
	inet_unregister_protosw(&sctp_stream_protosw);
	inet_unregister_protosw(&sctp_seqpacket_protosw);
	proto_unregister(&sctp_prot);
}

static int sctp_v4_add_protocol(void)
{
	/* Register notifier for inet address additions/deletions. */
	register_inetaddr_notifier(&sctp_inetaddr_notifier);

	/* Register SCTP with inet layer.  */
	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
		return -EAGAIN;

	return 0;
}

static void sctp_v4_del_protocol(void)
{
	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
}

static int __net_init sctp_defaults_init(struct net *net)
{
	int status;

	/*
	 * 14. Suggested SCTP Protocol Parameter Values
	 */
	/* The following protocol parameters are RECOMMENDED:  */
	/* RTO.Initial              - 3  seconds */
	net->sctp.rto_initial			= SCTP_RTO_INITIAL;
	/* RTO.Min                  - 1  second */
	net->sctp.rto_min	 		= SCTP_RTO_MIN;
	/* RTO.Max                 -  60 seconds */
	net->sctp.rto_max 			= SCTP_RTO_MAX;
	/* RTO.Alpha                - 1/8 */
	net->sctp.rto_alpha			= SCTP_RTO_ALPHA;
	/* RTO.Beta                 - 1/4 */
	net->sctp.rto_beta			= SCTP_RTO_BETA;

	/* Valid.Cookie.Life        - 60  seconds */
	net->sctp.valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;

	/* Whether Cookie Preservative is enabled(1) or not(0) */
	net->sctp.cookie_preserve_enable 	= 1;

	/* Default sctp sockets to use md5 as their hmac alg */
#if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
	net->sctp.sctp_hmac_alg			= "md5";
#elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
	net->sctp.sctp_hmac_alg			= "sha1";
#else
	net->sctp.sctp_hmac_alg			= NULL;
#endif

	/* Max.Burst		    - 4 */
	net->sctp.max_burst			= SCTP_DEFAULT_MAX_BURST;

	/* Enable pf state by default */
	net->sctp.pf_enable = 1;

	/* Association.Max.Retrans  - 10 attempts
	 * Path.Max.Retrans         - 5  attempts (per destination address)
	 * Max.Init.Retransmits     - 8  attempts
	 */
	net->sctp.max_retrans_association	= 10;
	net->sctp.max_retrans_path		= 5;
	net->sctp.max_retrans_init		= 8;

	/* Sendbuffer growth	    - do per-socket accounting */
	net->sctp.sndbuf_policy			= 0;

	/* Rcvbuffer growth	    - do per-socket accounting */
	net->sctp.rcvbuf_policy			= 0;

	/* HB.interval              - 30 seconds */
	net->sctp.hb_interval			= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;

	/* delayed SACK timeout */
	net->sctp.sack_timeout			= SCTP_DEFAULT_TIMEOUT_SACK;

	/* Disable ADDIP by default. */
	net->sctp.addip_enable = 0;
	net->sctp.addip_noauth = 0;
	net->sctp.default_auto_asconf = 0;

	/* Enable PR-SCTP by default. */
	net->sctp.prsctp_enable = 1;

	/* Disable RECONF by default. */
	net->sctp.reconf_enable = 0;

	/* Disable AUTH by default. */
	net->sctp.auth_enable = 0;

	/* Set SCOPE policy to enabled */
	net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;

	/* Set the default rwnd update threshold */
	net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;

	/* Initialize maximum autoclose timeout. */
	net->sctp.max_autoclose		= INT_MAX / HZ;

	status = sctp_sysctl_net_register(net);
	if (status)
		goto err_sysctl_register;

	/* Allocate and initialise sctp mibs.  */
	status = init_sctp_mibs(net);
	if (status)
		goto err_init_mibs;

	/* Initialize proc fs directory.  */
	status = sctp_proc_init(net);
	if (status)
		goto err_init_proc;

	sctp_dbg_objcnt_init(net);

	/* Initialize the local address list. */
	INIT_LIST_HEAD(&net->sctp.local_addr_list);
	spin_lock_init(&net->sctp.local_addr_lock);
	sctp_get_local_addr_list(net);

	/* Initialize the address event list */
	INIT_LIST_HEAD(&net->sctp.addr_waitq);
	INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
	spin_lock_init(&net->sctp.addr_wq_lock);
	net->sctp.addr_wq_timer.expires = 0;
	setup_timer(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler,
		    (unsigned long)net);

	return 0;

err_init_proc:
	cleanup_sctp_mibs(net);
err_init_mibs:
	sctp_sysctl_net_unregister(net);
err_sysctl_register:
	return status;
}

static void __net_exit sctp_defaults_exit(struct net *net)
{
	/* Free the local address list */
	sctp_free_addr_wq(net);
	sctp_free_local_addr_list(net);

	sctp_dbg_objcnt_exit(net);

	sctp_proc_exit(net);
	cleanup_sctp_mibs(net);
	sctp_sysctl_net_unregister(net);
}

static struct pernet_operations sctp_defaults_ops = {
	.init = sctp_defaults_init,
	.exit = sctp_defaults_exit,
};

static int __net_init sctp_ctrlsock_init(struct net *net)
{
	int status;

	/* Initialize the control inode/socket for handling OOTB packets.  */
	status = sctp_ctl_sock_init(net);
	if (status)
		pr_err("Failed to initialize the SCTP control sock\n");

	return status;
}

static void __net_init sctp_ctrlsock_exit(struct net *net)
{
	/* Free the control endpoint.  */
	inet_ctl_sock_destroy(net->sctp.ctl_sock);
}

static struct pernet_operations sctp_ctrlsock_ops = {
	.init = sctp_ctrlsock_init,
	.exit = sctp_ctrlsock_exit,
};

/* Initialize the universe into something sensible.  */
static __init int sctp_init(void)
{
	int i;
	int status = -EINVAL;
	unsigned long goal;
	unsigned long limit;
	int max_share;
	int order;
	int num_entries;
	int max_entry_order;

	sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));

	/* Allocate bind_bucket and chunk caches. */
	status = -ENOBUFS;
	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
					       sizeof(struct sctp_bind_bucket),
					       0, SLAB_HWCACHE_ALIGN,
					       NULL);
	if (!sctp_bucket_cachep)
		goto out;

	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
					       sizeof(struct sctp_chunk),
					       0, SLAB_HWCACHE_ALIGN,
					       NULL);
	if (!sctp_chunk_cachep)
		goto err_chunk_cachep;

	status = percpu_counter_init(&sctp_sockets_allocated, 0, GFP_KERNEL);
	if (status)
		goto err_percpu_counter_init;

	/* Implementation specific variables. */

	/* Initialize default stream count setup information. */
	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;

	/* Initialize handle used for association ids. */
	idr_init(&sctp_assocs_id);

	limit = nr_free_buffer_pages() / 8;
	limit = max(limit, 128UL);
	sysctl_sctp_mem[0] = limit / 4 * 3;
	sysctl_sctp_mem[1] = limit;
	sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;

	/* Set per-socket limits to no more than 1/128 the pressure threshold*/
	limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
	max_share = min(4UL*1024*1024, limit);

	sysctl_sctp_rmem[0] = SK_MEM_QUANTUM; /* give each asoc 1 page min */
	sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);

	sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
	sysctl_sctp_wmem[1] = 16*1024;
	sysctl_sctp_wmem[2] = max(64*1024, max_share);

	/* Size and allocate the association hash table.
	 * The methodology is similar to that of the tcp hash tables.
	 * Though not identical.  Start by getting a goal size
	 */
	if (totalram_pages >= (128 * 1024))
		goal = totalram_pages >> (22 - PAGE_SHIFT);
	else
		goal = totalram_pages >> (24 - PAGE_SHIFT);

	/* Then compute the page order for said goal */
	order = get_order(goal);

	/* Now compute the required page order for the maximum sized table we
	 * want to create
	 */
	max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
				    sizeof(struct sctp_bind_hashbucket));

	/* Limit the page order by that maximum hash table size */
	order = min(order, max_entry_order);

	/* Allocate and initialize the endpoint hash table.  */
	sctp_ep_hashsize = 64;
	sctp_ep_hashtable =
		kmalloc(64 * sizeof(struct sctp_hashbucket), GFP_KERNEL);
	if (!sctp_ep_hashtable) {
		pr_err("Failed endpoint_hash alloc\n");
		status = -ENOMEM;
		goto err_ehash_alloc;
	}
	for (i = 0; i < sctp_ep_hashsize; i++) {
		rwlock_init(&sctp_ep_hashtable[i].lock);
		INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
	}

	/* Allocate and initialize the SCTP port hash table.
	 * Note that order is initalized to start at the max sized
	 * table we want to support.  If we can't get that many pages
	 * reduce the order and try again
	 */
	do {
		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
			__get_free_pages(GFP_KERNEL | __GFP_NOWARN, order);
	} while (!sctp_port_hashtable && --order > 0);

	if (!sctp_port_hashtable) {
		pr_err("Failed bind hash alloc\n");
		status = -ENOMEM;
		goto err_bhash_alloc;
	}

	/* Now compute the number of entries that will fit in the
	 * port hash space we allocated
	 */
	num_entries = (1UL << order) * PAGE_SIZE /
		      sizeof(struct sctp_bind_hashbucket);

	/* And finish by rounding it down to the nearest power of two
	 * this wastes some memory of course, but its needed because
	 * the hash function operates based on the assumption that
	 * that the number of entries is a power of two
	 */
	sctp_port_hashsize = rounddown_pow_of_two(num_entries);

	for (i = 0; i < sctp_port_hashsize; i++) {
		spin_lock_init(&sctp_port_hashtable[i].lock);
		INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
	}

	status = sctp_transport_hashtable_init();
	if (status)
		goto err_thash_alloc;

	pr_info("Hash tables configured (bind %d/%d)\n", sctp_port_hashsize,
		num_entries);

	sctp_sysctl_register();

	INIT_LIST_HEAD(&sctp_address_families);
	sctp_v4_pf_init();
	sctp_v6_pf_init();

	status = register_pernet_subsys(&sctp_defaults_ops);
	if (status)
		goto err_register_defaults;

	status = sctp_v4_protosw_init();
	if (status)
		goto err_protosw_init;

	status = sctp_v6_protosw_init();
	if (status)
		goto err_v6_protosw_init;

	status = register_pernet_subsys(&sctp_ctrlsock_ops);
	if (status)
		goto err_register_ctrlsock;

	status = sctp_v4_add_protocol();
	if (status)
		goto err_add_protocol;

	/* Register SCTP with inet6 layer.  */
	status = sctp_v6_add_protocol();
	if (status)
		goto err_v6_add_protocol;

	if (sctp_offload_init() < 0)
		pr_crit("%s: Cannot add SCTP protocol offload\n", __func__);

out:
	return status;
err_v6_add_protocol:
	sctp_v4_del_protocol();
err_add_protocol:
	unregister_pernet_subsys(&sctp_ctrlsock_ops);
err_register_ctrlsock:
	sctp_v6_protosw_exit();
err_v6_protosw_init:
	sctp_v4_protosw_exit();
err_protosw_init:
	unregister_pernet_subsys(&sctp_defaults_ops);
err_register_defaults:
	sctp_v4_pf_exit();
	sctp_v6_pf_exit();
	sctp_sysctl_unregister();
	free_pages((unsigned long)sctp_port_hashtable,
		   get_order(sctp_port_hashsize *
			     sizeof(struct sctp_bind_hashbucket)));
err_bhash_alloc:
	sctp_transport_hashtable_destroy();
err_thash_alloc:
	kfree(sctp_ep_hashtable);
err_ehash_alloc:
	percpu_counter_destroy(&sctp_sockets_allocated);
err_percpu_counter_init:
	kmem_cache_destroy(sctp_chunk_cachep);
err_chunk_cachep:
	kmem_cache_destroy(sctp_bucket_cachep);
	goto out;
}

/* Exit handler for the SCTP protocol.  */
static __exit void sctp_exit(void)
{
	/* BUG.  This should probably do something useful like clean
	 * up all the remaining associations and all that memory.
	 */

	/* Unregister with inet6/inet layers. */
	sctp_v6_del_protocol();
	sctp_v4_del_protocol();

	unregister_pernet_subsys(&sctp_ctrlsock_ops);

	/* Free protosw registrations */
	sctp_v6_protosw_exit();
	sctp_v4_protosw_exit();

	unregister_pernet_subsys(&sctp_defaults_ops);

	/* Unregister with socket layer. */
	sctp_v6_pf_exit();
	sctp_v4_pf_exit();

	sctp_sysctl_unregister();

	free_pages((unsigned long)sctp_port_hashtable,
		   get_order(sctp_port_hashsize *
			     sizeof(struct sctp_bind_hashbucket)));
	kfree(sctp_ep_hashtable);
	sctp_transport_hashtable_destroy();

	percpu_counter_destroy(&sctp_sockets_allocated);

	rcu_barrier(); /* Wait for completion of call_rcu()'s */

	kmem_cache_destroy(sctp_chunk_cachep);
	kmem_cache_destroy(sctp_bucket_cachep);
}

module_init(sctp_init);
module_exit(sctp_exit);

/*
 * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
 */
MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
MODULE_LICENSE("GPL");