net/netfilter/ipvs/ip_vs_proto_sctp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/kernel.h>
   3 #include <linux/ip.h>
   4 #include <linux/sctp.h>
   5 #include <net/ip.h>
   6 #include <net/ip6_checksum.h>
   7 #include <linux/netfilter.h>
   8 #include <linux/netfilter_ipv4.h>
   9 #include <net/sctp/checksum.h>
  10 #include <net/ip_vs.h>
  11
  12 static int
  13 sctp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb,
  14                    struct ip_vs_proto_data *pd,
  15                    int *verdict, struct ip_vs_conn **cpp,
  16                    struct ip_vs_iphdr *iph)
  17 {
  18         struct ip_vs_service *svc;
  19         struct sctp_chunkhdr _schunkh, *sch;
  20         struct sctphdr *sh, _sctph;
  21         __be16 _ports[2], *ports = NULL;
  22
  23         if (likely(!ip_vs_iph_icmp(iph))) {
  24                 sh = skb_header_pointer(skb, iph->len, sizeof(_sctph), &_sctph);
  25                 if (sh) {
  26                         sch = skb_header_pointer(skb, iph->len + sizeof(_sctph),
  27                                                  sizeof(_schunkh), &_schunkh);
  28                         if (sch) {
  29                                 if (sch->type == SCTP_CID_ABORT ||
  30                                     !(sysctl_sloppy_sctp(ipvs) ||
  31                                       sch->type == SCTP_CID_INIT))
  32                                         return 1;
  33                                 ports = &sh->source;
  34                         }
  35                 }
  36         } else {
  37                 ports = skb_header_pointer(
  38                         skb, iph->len, sizeof(_ports), &_ports);
  39         }
  40
  41         if (!ports) {
  42                 *verdict = NF_DROP;
  43                 return 0;
  44         }
  45
  46         if (likely(!ip_vs_iph_inverse(iph)))
  47                 svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol,
  48                                          &iph->daddr, ports[1]);
  49         else
  50                 svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol,
  51                                          &iph->saddr, ports[0]);
  52         if (svc) {
  53                 int ignored;
  54
  55                 if (ip_vs_todrop(ipvs)) {
  56                         /*
  57                          * It seems that we are very loaded.
  58                          * We have to drop this packet :(
  59                          */
  60                         *verdict = NF_DROP;
  61                         return 0;
  62                 }
  63                 /*
  64                  * Let the virtual server select a real server for the
  65                  * incoming connection, and create a connection entry.
  66                  */
  67                 *cpp = ip_vs_schedule(svc, skb, pd, &ignored, iph);
  68                 if (!*cpp && ignored <= 0) {
  69                         if (!ignored)
  70                                 *verdict = ip_vs_leave(svc, skb, pd, iph);
  71                         else
  72                                 *verdict = NF_DROP;
  73                         return 0;
  74                 }
  75         }
  76         /* NF_ACCEPT */
  77         return 1;
  78 }
  79
  80 static void sctp_nat_csum(struct sk_buff *skb, struct sctphdr *sctph,
  81                           unsigned int sctphoff)
  82 {
  83         sctph->checksum = sctp_compute_cksum(skb, sctphoff);
  84         skb->ip_summed = CHECKSUM_UNNECESSARY;
  85 }
  86
  87 static int
  88 sctp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
  89                   struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
  90 {
  91         struct sctphdr *sctph;
  92         unsigned int sctphoff = iph->len;
  93         bool payload_csum = false;
  94
  95 #ifdef CONFIG_IP_VS_IPV6
  96         if (cp->af == AF_INET6 && iph->fragoffs)
  97                 return 1;
  98 #endif
  99
 100         /* csum_check requires unshared skb */
 101         if (!skb_make_writable(skb, sctphoff + sizeof(*sctph)))
 102                 return 0;
 103
 104         if (unlikely(cp->app != NULL)) {
 105                 int ret;
 106
 107                 /* Some checks before mangling */
 108                 if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
 109                         return 0;
 110
 111                 /* Call application helper if needed */
 112                 ret = ip_vs_app_pkt_out(cp, skb);
 113                 if (ret == 0)
 114                         return 0;
 115                 /* ret=2: csum update is needed after payload mangling */
 116                 if (ret == 2)
 117                         payload_csum = true;
 118         }
 119
 120         sctph = (void *) skb_network_header(skb) + sctphoff;
 121
 122         /* Only update csum if we really have to */
 123         if (sctph->source != cp->vport || payload_csum ||
 124             skb->ip_summed == CHECKSUM_PARTIAL) {
 125                 sctph->source = cp->vport;
 126                 sctp_nat_csum(skb, sctph, sctphoff);
 127         } else {
 128                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 129         }
 130
 131         return 1;
 132 }
 133
 134 static int
 135 sctp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
 136                   struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
 137 {
 138         struct sctphdr *sctph;
 139         unsigned int sctphoff = iph->len;
 140         bool payload_csum = false;
 141
 142 #ifdef CONFIG_IP_VS_IPV6
 143         if (cp->af == AF_INET6 && iph->fragoffs)
 144                 return 1;
 145 #endif
 146
 147         /* csum_check requires unshared skb */
 148         if (!skb_make_writable(skb, sctphoff + sizeof(*sctph)))
 149                 return 0;
 150
 151         if (unlikely(cp->app != NULL)) {
 152                 int ret;
 153
 154                 /* Some checks before mangling */
 155                 if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
 156                         return 0;
 157
 158                 /* Call application helper if needed */
 159                 ret = ip_vs_app_pkt_in(cp, skb);
 160                 if (ret == 0)
 161                         return 0;
 162                 /* ret=2: csum update is needed after payload mangling */
 163                 if (ret == 2)
 164                         payload_csum = true;
 165         }
 166
 167         sctph = (void *) skb_network_header(skb) + sctphoff;
 168
 169         /* Only update csum if we really have to */
 170         if (sctph->dest != cp->dport || payload_csum ||
 171             (skb->ip_summed == CHECKSUM_PARTIAL &&
 172              !(skb_dst(skb)->dev->features & NETIF_F_SCTP_CRC))) {
 173                 sctph->dest = cp->dport;
 174                 sctp_nat_csum(skb, sctph, sctphoff);
 175         } else if (skb->ip_summed != CHECKSUM_PARTIAL) {
 176                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 177         }
 178
 179         return 1;
 180 }
 181
 182 static int
 183 sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
 184 {
 185         unsigned int sctphoff;
 186         struct sctphdr *sh, _sctph;
 187         __le32 cmp, val;
 188
 189 #ifdef CONFIG_IP_VS_IPV6
 190         if (af == AF_INET6)
 191                 sctphoff = sizeof(struct ipv6hdr);
 192         else
 193 #endif
 194                 sctphoff = ip_hdrlen(skb);
 195
 196         sh = skb_header_pointer(skb, sctphoff, sizeof(_sctph), &_sctph);
 197         if (sh == NULL)
 198                 return 0;
 199
 200         cmp = sh->checksum;
 201         val = sctp_compute_cksum(skb, sctphoff);
 202
 203         if (val != cmp) {
 204                 /* CRC failure, dump it. */
 205                 IP_VS_DBG_RL_PKT(0, af, pp, skb, 0,
 206                                 "Failed checksum for");
 207                 return 0;
 208         }
 209         return 1;
 210 }
 211
 212 enum ipvs_sctp_event_t {
 213         IP_VS_SCTP_DATA = 0,            /* DATA, SACK, HEARTBEATs */
 214         IP_VS_SCTP_INIT,
 215         IP_VS_SCTP_INIT_ACK,
 216         IP_VS_SCTP_COOKIE_ECHO,
 217         IP_VS_SCTP_COOKIE_ACK,
 218         IP_VS_SCTP_SHUTDOWN,
 219         IP_VS_SCTP_SHUTDOWN_ACK,
 220         IP_VS_SCTP_SHUTDOWN_COMPLETE,
 221         IP_VS_SCTP_ERROR,
 222         IP_VS_SCTP_ABORT,
 223         IP_VS_SCTP_EVENT_LAST
 224 };
 225
 226 /* RFC 2960, 3.2 Chunk Field Descriptions */
 227 static __u8 sctp_events[] = {
 228         [SCTP_CID_DATA]                 = IP_VS_SCTP_DATA,
 229         [SCTP_CID_INIT]                 = IP_VS_SCTP_INIT,
 230         [SCTP_CID_INIT_ACK]             = IP_VS_SCTP_INIT_ACK,
 231         [SCTP_CID_SACK]                 = IP_VS_SCTP_DATA,
 232         [SCTP_CID_HEARTBEAT]            = IP_VS_SCTP_DATA,
 233         [SCTP_CID_HEARTBEAT_ACK]        = IP_VS_SCTP_DATA,
 234         [SCTP_CID_ABORT]                = IP_VS_SCTP_ABORT,
 235         [SCTP_CID_SHUTDOWN]             = IP_VS_SCTP_SHUTDOWN,
 236         [SCTP_CID_SHUTDOWN_ACK]         = IP_VS_SCTP_SHUTDOWN_ACK,
 237         [SCTP_CID_ERROR]                = IP_VS_SCTP_ERROR,
 238         [SCTP_CID_COOKIE_ECHO]          = IP_VS_SCTP_COOKIE_ECHO,
 239         [SCTP_CID_COOKIE_ACK]           = IP_VS_SCTP_COOKIE_ACK,
 240         [SCTP_CID_ECN_ECNE]             = IP_VS_SCTP_DATA,
 241         [SCTP_CID_ECN_CWR]              = IP_VS_SCTP_DATA,
 242         [SCTP_CID_SHUTDOWN_COMPLETE]    = IP_VS_SCTP_SHUTDOWN_COMPLETE,
 243 };
 244
 245 /* SCTP States:
 246  * See RFC 2960, 4. SCTP Association State Diagram
 247  *
 248  * New states (not in diagram):
 249  * - INIT1 state: use shorter timeout for dropped INIT packets
 250  * - REJECTED state: use shorter timeout if INIT is rejected with ABORT
 251  * - INIT, COOKIE_SENT, COOKIE_REPLIED, COOKIE states: for better debugging
 252  *
 253  * The states are as seen in real server. In the diagram, INIT1, INIT,
 254  * COOKIE_SENT and COOKIE_REPLIED processing happens in CLOSED state.
 255  *
 256  * States as per packets from client (C) and server (S):
 257  *
 258  * Setup of client connection:
 259  * IP_VS_SCTP_S_INIT1: First C:INIT sent, wait for S:INIT-ACK
 260  * IP_VS_SCTP_S_INIT: Next C:INIT sent, wait for S:INIT-ACK
 261  * IP_VS_SCTP_S_COOKIE_SENT: S:INIT-ACK sent, wait for C:COOKIE-ECHO
 262  * IP_VS_SCTP_S_COOKIE_REPLIED: C:COOKIE-ECHO sent, wait for S:COOKIE-ACK
 263  *
 264  * Setup of server connection:
 265  * IP_VS_SCTP_S_COOKIE_WAIT: S:INIT sent, wait for C:INIT-ACK
 266  * IP_VS_SCTP_S_COOKIE: C:INIT-ACK sent, wait for S:COOKIE-ECHO
 267  * IP_VS_SCTP_S_COOKIE_ECHOED: S:COOKIE-ECHO sent, wait for C:COOKIE-ACK
 268  */
 269
 270 #define sNO IP_VS_SCTP_S_NONE
 271 #define sI1 IP_VS_SCTP_S_INIT1
 272 #define sIN IP_VS_SCTP_S_INIT
 273 #define sCS IP_VS_SCTP_S_COOKIE_SENT
 274 #define sCR IP_VS_SCTP_S_COOKIE_REPLIED
 275 #define sCW IP_VS_SCTP_S_COOKIE_WAIT
 276 #define sCO IP_VS_SCTP_S_COOKIE
 277 #define sCE IP_VS_SCTP_S_COOKIE_ECHOED
 278 #define sES IP_VS_SCTP_S_ESTABLISHED
 279 #define sSS IP_VS_SCTP_S_SHUTDOWN_SENT
 280 #define sSR IP_VS_SCTP_S_SHUTDOWN_RECEIVED
 281 #define sSA IP_VS_SCTP_S_SHUTDOWN_ACK_SENT
 282 #define sRJ IP_VS_SCTP_S_REJECTED
 283 #define sCL IP_VS_SCTP_S_CLOSED
 284
 285 static const __u8 sctp_states
 286         [IP_VS_DIR_LAST][IP_VS_SCTP_EVENT_LAST][IP_VS_SCTP_S_LAST] = {
 287         { /* INPUT */
 288 /*        sNO, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL*/
 289 /* d   */{sES, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 290 /* i   */{sI1, sIN, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sIN, sIN},
 291 /* i_a */{sCW, sCW, sCW, sCS, sCR, sCO, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 292 /* c_e */{sCR, sIN, sIN, sCR, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 293 /* c_a */{sES, sI1, sIN, sCS, sCR, sCW, sCO, sES, sES, sSS, sSR, sSA, sRJ, sCL},
 294 /* s   */{sSR, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sSR, sSS, sSR, sSA, sRJ, sCL},
 295 /* s_a */{sCL, sIN, sIN, sCS, sCR, sCW, sCO, sCE, sES, sCL, sSR, sCL, sRJ, sCL},
 296 /* s_c */{sCL, sCL, sCL, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sCL, sRJ, sCL},
 297 /* err */{sCL, sI1, sIN, sCS, sCR, sCW, sCO, sCL, sES, sSS, sSR, sSA, sRJ, sCL},
 298 /* ab  */{sCL, sCL, sCL, sCL, sCL, sRJ, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 299         },
 300         { /* OUTPUT */
 301 /*        sNO, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL*/
 302 /* d   */{sES, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 303 /* i   */{sCW, sCW, sCW, sCW, sCW, sCW, sCW, sCW, sES, sCW, sCW, sCW, sCW, sCW},
 304 /* i_a */{sCS, sCS, sCS, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 305 /* c_e */{sCE, sCE, sCE, sCE, sCE, sCE, sCE, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 306 /* c_a */{sES, sES, sES, sES, sES, sES, sES, sES, sES, sSS, sSR, sSA, sRJ, sCL},
 307 /* s   */{sSS, sSS, sSS, sSS, sSS, sSS, sSS, sSS, sSS, sSS, sSR, sSA, sRJ, sCL},
 308 /* s_a */{sSA, sSA, sSA, sSA, sSA, sCW, sCO, sCE, sES, sSA, sSA, sSA, sRJ, sCL},
 309 /* s_c */{sCL, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 310 /* err */{sCL, sCL, sCL, sCL, sCL, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 311 /* ab  */{sCL, sRJ, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 312         },
 313         { /* INPUT-ONLY */
 314 /*        sNO, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL*/
 315 /* d   */{sES, sI1, sIN, sCS, sCR, sES, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 316 /* i   */{sI1, sIN, sIN, sIN, sIN, sIN, sCO, sCE, sES, sSS, sSR, sSA, sIN, sIN},
 317 /* i_a */{sCE, sCE, sCE, sCE, sCE, sCE, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 318 /* c_e */{sES, sES, sES, sES, sES, sES, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 319 /* c_a */{sES, sI1, sIN, sES, sES, sCW, sES, sES, sES, sSS, sSR, sSA, sRJ, sCL},
 320 /* s   */{sSR, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sSR, sSS, sSR, sSA, sRJ, sCL},
 321 /* s_a */{sCL, sIN, sIN, sCS, sCR, sCW, sCO, sCE, sCL, sCL, sSR, sCL, sRJ, sCL},
 322 /* s_c */{sCL, sCL, sCL, sCL, sCL, sCW, sCO, sCE, sES, sSS, sCL, sCL, sRJ, sCL},
 323 /* err */{sCL, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 324 /* ab  */{sCL, sCL, sCL, sCL, sCL, sRJ, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 325         },
 326 };
 327
 328 #define IP_VS_SCTP_MAX_RTO      ((60 + 1) * HZ)
 329
 330 /* Timeout table[state] */
 331 static const int sctp_timeouts[IP_VS_SCTP_S_LAST + 1] = {
 332         [IP_VS_SCTP_S_NONE]                     = 2 * HZ,
 333         [IP_VS_SCTP_S_INIT1]                    = (0 + 3 + 1) * HZ,
 334         [IP_VS_SCTP_S_INIT]                     = IP_VS_SCTP_MAX_RTO,
 335         [IP_VS_SCTP_S_COOKIE_SENT]              = IP_VS_SCTP_MAX_RTO,
 336         [IP_VS_SCTP_S_COOKIE_REPLIED]           = IP_VS_SCTP_MAX_RTO,
 337         [IP_VS_SCTP_S_COOKIE_WAIT]              = IP_VS_SCTP_MAX_RTO,
 338         [IP_VS_SCTP_S_COOKIE]                   = IP_VS_SCTP_MAX_RTO,
 339         [IP_VS_SCTP_S_COOKIE_ECHOED]            = IP_VS_SCTP_MAX_RTO,
 340         [IP_VS_SCTP_S_ESTABLISHED]              = 15 * 60 * HZ,
 341         [IP_VS_SCTP_S_SHUTDOWN_SENT]            = IP_VS_SCTP_MAX_RTO,
 342         [IP_VS_SCTP_S_SHUTDOWN_RECEIVED]        = IP_VS_SCTP_MAX_RTO,
 343         [IP_VS_SCTP_S_SHUTDOWN_ACK_SENT]        = IP_VS_SCTP_MAX_RTO,
 344         [IP_VS_SCTP_S_REJECTED]                 = (0 + 3 + 1) * HZ,
 345         [IP_VS_SCTP_S_CLOSED]                   = IP_VS_SCTP_MAX_RTO,
 346         [IP_VS_SCTP_S_LAST]                     = 2 * HZ,
 347 };
 348
 349 static const char *sctp_state_name_table[IP_VS_SCTP_S_LAST + 1] = {
 350         [IP_VS_SCTP_S_NONE]                     = "NONE",
 351         [IP_VS_SCTP_S_INIT1]                    = "INIT1",
 352         [IP_VS_SCTP_S_INIT]                     = "INIT",
 353         [IP_VS_SCTP_S_COOKIE_SENT]              = "C-SENT",
 354         [IP_VS_SCTP_S_COOKIE_REPLIED]           = "C-REPLIED",
 355         [IP_VS_SCTP_S_COOKIE_WAIT]              = "C-WAIT",
 356         [IP_VS_SCTP_S_COOKIE]                   = "COOKIE",
 357         [IP_VS_SCTP_S_COOKIE_ECHOED]            = "C-ECHOED",
 358         [IP_VS_SCTP_S_ESTABLISHED]              = "ESTABLISHED",
 359         [IP_VS_SCTP_S_SHUTDOWN_SENT]            = "S-SENT",
 360         [IP_VS_SCTP_S_SHUTDOWN_RECEIVED]        = "S-RECEIVED",
 361         [IP_VS_SCTP_S_SHUTDOWN_ACK_SENT]        = "S-ACK-SENT",
 362         [IP_VS_SCTP_S_REJECTED]                 = "REJECTED",
 363         [IP_VS_SCTP_S_CLOSED]                   = "CLOSED",
 364         [IP_VS_SCTP_S_LAST]                     = "BUG!",
 365 };
 366
 367
 368 static const char *sctp_state_name(int state)
 369 {
 370         if (state >= IP_VS_SCTP_S_LAST)
 371                 return "ERR!";
 372         if (sctp_state_name_table[state])
 373                 return sctp_state_name_table[state];
 374         return "?";
 375 }
 376
 377 static inline void
 378 set_sctp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
 379                 int direction, const struct sk_buff *skb)
 380 {
 381         struct sctp_chunkhdr _sctpch, *sch;
 382         unsigned char chunk_type;
 383         int event, next_state;
 384         int ihl, cofs;
 385
 386 #ifdef CONFIG_IP_VS_IPV6
 387         ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr);
 388 #else
 389         ihl = ip_hdrlen(skb);
 390 #endif
 391
 392         cofs = ihl + sizeof(struct sctphdr);
 393         sch = skb_header_pointer(skb, cofs, sizeof(_sctpch), &_sctpch);
 394         if (sch == NULL)
 395                 return;
 396
 397         chunk_type = sch->type;
 398         /*
 399          * Section 3: Multiple chunks can be bundled into one SCTP packet
 400          * up to the MTU size, except for the INIT, INIT ACK, and
 401          * SHUTDOWN COMPLETE chunks. These chunks MUST NOT be bundled with
 402          * any other chunk in a packet.
 403          *
 404          * Section 3.3.7: DATA chunks MUST NOT be bundled with ABORT. Control
 405          * chunks (except for INIT, INIT ACK, and SHUTDOWN COMPLETE) MAY be
 406          * bundled with an ABORT, but they MUST be placed before the ABORT
 407          * in the SCTP packet or they will be ignored by the receiver.
 408          */
 409         if ((sch->type == SCTP_CID_COOKIE_ECHO) ||
 410             (sch->type == SCTP_CID_COOKIE_ACK)) {
 411                 int clen = ntohs(sch->length);
 412
 413                 if (clen >= sizeof(_sctpch)) {
 414                         sch = skb_header_pointer(skb, cofs + ALIGN(clen, 4),
 415                                                  sizeof(_sctpch), &_sctpch);
 416                         if (sch && sch->type == SCTP_CID_ABORT)
 417                                 chunk_type = sch->type;
 418                 }
 419         }
 420
 421         event = (chunk_type < sizeof(sctp_events)) ?
 422                 sctp_events[chunk_type] : IP_VS_SCTP_DATA;
 423
 424         /* Update direction to INPUT_ONLY if necessary
 425          * or delete NO_OUTPUT flag if output packet detected
 426          */
 427         if (cp->flags & IP_VS_CONN_F_NOOUTPUT) {
 428                 if (direction == IP_VS_DIR_OUTPUT)
 429                         cp->flags &= ~IP_VS_CONN_F_NOOUTPUT;
 430                 else
 431                         direction = IP_VS_DIR_INPUT_ONLY;
 432         }
 433
 434         next_state = sctp_states[direction][event][cp->state];
 435
 436         if (next_state != cp->state) {
 437                 struct ip_vs_dest *dest = cp->dest;
 438
 439                 IP_VS_DBG_BUF(8, "%s %s  %s:%d->"
 440                                 "%s:%d state: %s->%s conn->refcnt:%d\n",
 441                                 pd->pp->name,
 442                                 ((direction == IP_VS_DIR_OUTPUT) ?
 443                                  "output " : "input "),
 444                                 IP_VS_DBG_ADDR(cp->daf, &cp->daddr),
 445                                 ntohs(cp->dport),
 446                                 IP_VS_DBG_ADDR(cp->af, &cp->caddr),
 447                                 ntohs(cp->cport),
 448                                 sctp_state_name(cp->state),
 449                                 sctp_state_name(next_state),
 450                                 refcount_read(&cp->refcnt));
 451                 if (dest) {
 452                         if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
 453                                 (next_state != IP_VS_SCTP_S_ESTABLISHED)) {
 454                                 atomic_dec(&dest->activeconns);
 455                                 atomic_inc(&dest->inactconns);
 456                                 cp->flags |= IP_VS_CONN_F_INACTIVE;
 457                         } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) &&
 458                                    (next_state == IP_VS_SCTP_S_ESTABLISHED)) {
 459                                 atomic_inc(&dest->activeconns);
 460                                 atomic_dec(&dest->inactconns);
 461                                 cp->flags &= ~IP_VS_CONN_F_INACTIVE;
 462                         }
 463                 }
 464         }
 465         if (likely(pd))
 466                 cp->timeout = pd->timeout_table[cp->state = next_state];
 467         else    /* What to do ? */
 468                 cp->timeout = sctp_timeouts[cp->state = next_state];
 469 }
 470
 471 static void
 472 sctp_state_transition(struct ip_vs_conn *cp, int direction,
 473                 const struct sk_buff *skb, struct ip_vs_proto_data *pd)
 474 {
 475         spin_lock_bh(&cp->lock);
 476         set_sctp_state(pd, cp, direction, skb);
 477         spin_unlock_bh(&cp->lock);
 478 }
 479
 480 static inline __u16 sctp_app_hashkey(__be16 port)
 481 {
 482         return (((__force u16)port >> SCTP_APP_TAB_BITS) ^ (__force u16)port)
 483                 & SCTP_APP_TAB_MASK;
 484 }
 485
 486 static int sctp_register_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc)
 487 {
 488         struct ip_vs_app *i;
 489         __u16 hash;
 490         __be16 port = inc->port;
 491         int ret = 0;
 492         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_SCTP);
 493
 494         hash = sctp_app_hashkey(port);
 495
 496         list_for_each_entry(i, &ipvs->sctp_apps[hash], p_list) {
 497                 if (i->port == port) {
 498                         ret = -EEXIST;
 499                         goto out;
 500                 }
 501         }
 502         list_add_rcu(&inc->p_list, &ipvs->sctp_apps[hash]);
 503         atomic_inc(&pd->appcnt);
 504 out:
 505
 506         return ret;
 507 }
 508
 509 static void sctp_unregister_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc)
 510 {
 511         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_SCTP);
 512
 513         atomic_dec(&pd->appcnt);
 514         list_del_rcu(&inc->p_list);
 515 }
 516
 517 static int sctp_app_conn_bind(struct ip_vs_conn *cp)
 518 {
 519         struct netns_ipvs *ipvs = cp->ipvs;
 520         int hash;
 521         struct ip_vs_app *inc;
 522         int result = 0;
 523
 524         /* Default binding: bind app only for NAT */
 525         if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
 526                 return 0;
 527         /* Lookup application incarnations and bind the right one */
 528         hash = sctp_app_hashkey(cp->vport);
 529
 530         list_for_each_entry_rcu(inc, &ipvs->sctp_apps[hash], p_list) {
 531                 if (inc->port == cp->vport) {
 532                         if (unlikely(!ip_vs_app_inc_get(inc)))
 533                                 break;
 534
 535                         IP_VS_DBG_BUF(9, "%s: Binding conn %s:%u->"
 536                                         "%s:%u to app %s on port %u\n",
 537                                         __func__,
 538                                         IP_VS_DBG_ADDR(cp->af, &cp->caddr),
 539                                         ntohs(cp->cport),
 540                                         IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
 541                                         ntohs(cp->vport),
 542                                         inc->name, ntohs(inc->port));
 543                         cp->app = inc;
 544                         if (inc->init_conn)
 545                                 result = inc->init_conn(inc, cp);
 546                         break;
 547                 }
 548         }
 549
 550         return result;
 551 }
 552
 553 /* ---------------------------------------------
 554  *   timeouts is netns related now.
 555  * ---------------------------------------------
 556  */
 557 static int __ip_vs_sctp_init(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd)
 558 {
 559         ip_vs_init_hash_table(ipvs->sctp_apps, SCTP_APP_TAB_SIZE);
 560         pd->timeout_table = ip_vs_create_timeout_table((int *)sctp_timeouts,
 561                                                         sizeof(sctp_timeouts));
 562         if (!pd->timeout_table)
 563                 return -ENOMEM;
 564         return 0;
 565 }
 566
 567 static void __ip_vs_sctp_exit(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd)
 568 {
 569         kfree(pd->timeout_table);
 570 }
 571
 572 struct ip_vs_protocol ip_vs_protocol_sctp = {
 573         .name           = "SCTP",
 574         .protocol       = IPPROTO_SCTP,
 575         .num_states     = IP_VS_SCTP_S_LAST,
 576         .dont_defrag    = 0,
 577         .init           = NULL,
 578         .exit           = NULL,
 579         .init_netns     = __ip_vs_sctp_init,
 580         .exit_netns     = __ip_vs_sctp_exit,
 581         .register_app   = sctp_register_app,
 582         .unregister_app = sctp_unregister_app,
 583         .conn_schedule  = sctp_conn_schedule,
 584         .conn_in_get    = ip_vs_conn_in_get_proto,
 585         .conn_out_get   = ip_vs_conn_out_get_proto,
 586         .snat_handler   = sctp_snat_handler,
 587         .dnat_handler   = sctp_dnat_handler,
 588         .csum_check     = sctp_csum_check,
 589         .state_name     = sctp_state_name,
 590         .state_transition = sctp_state_transition,
 591         .app_conn_bind  = sctp_app_conn_bind,
 592         .debug_packet   = ip_vs_tcpudp_debug_packet,
 593         .timeout_change = NULL,
 594 };