net/netfilter/ipvs/ip_vs_proto_sctp.c

   1 #include <linux/kernel.h>
   2 #include <linux/ip.h>
   3 #include <linux/sctp.h>
   4 #include <net/ip.h>
   5 #include <net/ip6_checksum.h>
   6 #include <linux/netfilter.h>
   7 #include <linux/netfilter_ipv4.h>
   8 #include <net/sctp/checksum.h>
   9 #include <net/ip_vs.h>
  10
  11 static int
  12 sctp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd,
  13                    int *verdict, struct ip_vs_conn **cpp,
  14                    struct ip_vs_iphdr *iph)
  15 {
  16         struct net *net;
  17         struct ip_vs_service *svc;
  18         struct netns_ipvs *ipvs;
  19         sctp_chunkhdr_t _schunkh, *sch;
  20         sctp_sctphdr_t *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(
  27                                 skb, iph->len + sizeof(sctp_sctphdr_t),
  28                                 sizeof(_schunkh), &_schunkh);
  29                         if (sch && (sch->type == SCTP_CID_INIT ||
  30                                     sysctl_sloppy_sctp(ipvs)))
  31                                 ports = &sh->source;
  32                 }
  33         } else {
  34                 ports = skb_header_pointer(
  35                         skb, iph->len, sizeof(_ports), &_ports);
  36         }
  37
  38         if (!ports) {
  39                 *verdict = NF_DROP;
  40                 return 0;
  41         }
  42
  43         net = skb_net(skb);
  44         ipvs = net_ipvs(net);
  45         rcu_read_lock();
  46         if (likely(!ip_vs_iph_inverse(iph)))
  47                 svc = ip_vs_service_find(net, af, skb->mark, iph->protocol,
  48                                          &iph->daddr, ports[1]);
  49         else
  50                 svc = ip_vs_service_find(net, 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                         rcu_read_unlock();
  61                         *verdict = NF_DROP;
  62                         return 0;
  63                 }
  64                 /*
  65                  * Let the virtual server select a real server for the
  66                  * incoming connection, and create a connection entry.
  67                  */
  68                 *cpp = ip_vs_schedule(svc, skb, pd, &ignored, iph);
  69                 if (!*cpp && ignored <= 0) {
  70                         if (!ignored)
  71                                 *verdict = ip_vs_leave(svc, skb, pd, iph);
  72                         else
  73                                 *verdict = NF_DROP;
  74                         rcu_read_unlock();
  75                         return 0;
  76                 }
  77         }
  78         rcu_read_unlock();
  79         /* NF_ACCEPT */
  80         return 1;
  81 }
  82
  83 static void sctp_nat_csum(struct sk_buff *skb, sctp_sctphdr_t *sctph,
  84                           unsigned int sctphoff)
  85 {
  86         sctph->checksum = sctp_compute_cksum(skb, sctphoff);
  87         skb->ip_summed = CHECKSUM_UNNECESSARY;
  88 }
  89
  90 static int
  91 sctp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
  92                   struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
  93 {
  94         sctp_sctphdr_t *sctph;
  95         unsigned int sctphoff = iph->len;
  96         bool payload_csum = false;
  97
  98 #ifdef CONFIG_IP_VS_IPV6
  99         if (cp->af == AF_INET6 && iph->fragoffs)
 100                 return 1;
 101 #endif
 102
 103         /* csum_check requires unshared skb */
 104         if (!skb_make_writable(skb, sctphoff + sizeof(*sctph)))
 105                 return 0;
 106
 107         if (unlikely(cp->app != NULL)) {
 108                 int ret;
 109
 110                 /* Some checks before mangling */
 111                 if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
 112                         return 0;
 113
 114                 /* Call application helper if needed */
 115                 ret = ip_vs_app_pkt_out(cp, skb);
 116                 if (ret == 0)
 117                         return 0;
 118                 /* ret=2: csum update is needed after payload mangling */
 119                 if (ret == 2)
 120                         payload_csum = true;
 121         }
 122
 123         sctph = (void *) skb_network_header(skb) + sctphoff;
 124
 125         /* Only update csum if we really have to */
 126         if (sctph->source != cp->vport || payload_csum ||
 127             skb->ip_summed == CHECKSUM_PARTIAL) {
 128                 sctph->source = cp->vport;
 129                 sctp_nat_csum(skb, sctph, sctphoff);
 130         } else {
 131                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 132         }
 133
 134         return 1;
 135 }
 136
 137 static int
 138 sctp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
 139                   struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
 140 {
 141         sctp_sctphdr_t *sctph;
 142         unsigned int sctphoff = iph->len;
 143         bool payload_csum = false;
 144
 145 #ifdef CONFIG_IP_VS_IPV6
 146         if (cp->af == AF_INET6 && iph->fragoffs)
 147                 return 1;
 148 #endif
 149
 150         /* csum_check requires unshared skb */
 151         if (!skb_make_writable(skb, sctphoff + sizeof(*sctph)))
 152                 return 0;
 153
 154         if (unlikely(cp->app != NULL)) {
 155                 int ret;
 156
 157                 /* Some checks before mangling */
 158                 if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
 159                         return 0;
 160
 161                 /* Call application helper if needed */
 162                 ret = ip_vs_app_pkt_in(cp, skb);
 163                 if (ret == 0)
 164                         return 0;
 165                 /* ret=2: csum update is needed after payload mangling */
 166                 if (ret == 2)
 167                         payload_csum = true;
 168         }
 169
 170         sctph = (void *) skb_network_header(skb) + sctphoff;
 171
 172         /* Only update csum if we really have to */
 173         if (sctph->dest != cp->dport || payload_csum ||
 174             (skb->ip_summed == CHECKSUM_PARTIAL &&
 175              !(skb_dst(skb)->dev->features & NETIF_F_SCTP_CSUM))) {
 176                 sctph->dest = cp->dport;
 177                 sctp_nat_csum(skb, sctph, sctphoff);
 178         } else if (skb->ip_summed != CHECKSUM_PARTIAL) {
 179                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 180         }
 181
 182         return 1;
 183 }
 184
 185 static int
 186 sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
 187 {
 188         unsigned int sctphoff;
 189         struct sctphdr *sh, _sctph;
 190         __le32 cmp, val;
 191
 192 #ifdef CONFIG_IP_VS_IPV6
 193         if (af == AF_INET6)
 194                 sctphoff = sizeof(struct ipv6hdr);
 195         else
 196 #endif
 197                 sctphoff = ip_hdrlen(skb);
 198
 199         sh = skb_header_pointer(skb, sctphoff, sizeof(_sctph), &_sctph);
 200         if (sh == NULL)
 201                 return 0;
 202
 203         cmp = sh->checksum;
 204         val = sctp_compute_cksum(skb, sctphoff);
 205
 206         if (val != cmp) {
 207                 /* CRC failure, dump it. */
 208                 IP_VS_DBG_RL_PKT(0, af, pp, skb, 0,
 209                                 "Failed checksum for");
 210                 return 0;
 211         }
 212         return 1;
 213 }
 214
 215 enum ipvs_sctp_event_t {
 216         IP_VS_SCTP_DATA = 0,            /* DATA, SACK, HEARTBEATs */
 217         IP_VS_SCTP_INIT,
 218         IP_VS_SCTP_INIT_ACK,
 219         IP_VS_SCTP_COOKIE_ECHO,
 220         IP_VS_SCTP_COOKIE_ACK,
 221         IP_VS_SCTP_SHUTDOWN,
 222         IP_VS_SCTP_SHUTDOWN_ACK,
 223         IP_VS_SCTP_SHUTDOWN_COMPLETE,
 224         IP_VS_SCTP_ERROR,
 225         IP_VS_SCTP_ABORT,
 226         IP_VS_SCTP_EVENT_LAST
 227 };
 228
 229 /* RFC 2960, 3.2 Chunk Field Descriptions */
 230 static __u8 sctp_events[] = {
 231         [SCTP_CID_DATA]                 = IP_VS_SCTP_DATA,
 232         [SCTP_CID_INIT]                 = IP_VS_SCTP_INIT,
 233         [SCTP_CID_INIT_ACK]             = IP_VS_SCTP_INIT_ACK,
 234         [SCTP_CID_SACK]                 = IP_VS_SCTP_DATA,
 235         [SCTP_CID_HEARTBEAT]            = IP_VS_SCTP_DATA,
 236         [SCTP_CID_HEARTBEAT_ACK]        = IP_VS_SCTP_DATA,
 237         [SCTP_CID_ABORT]                = IP_VS_SCTP_ABORT,
 238         [SCTP_CID_SHUTDOWN]             = IP_VS_SCTP_SHUTDOWN,
 239         [SCTP_CID_SHUTDOWN_ACK]         = IP_VS_SCTP_SHUTDOWN_ACK,
 240         [SCTP_CID_ERROR]                = IP_VS_SCTP_ERROR,
 241         [SCTP_CID_COOKIE_ECHO]          = IP_VS_SCTP_COOKIE_ECHO,
 242         [SCTP_CID_COOKIE_ACK]           = IP_VS_SCTP_COOKIE_ACK,
 243         [SCTP_CID_ECN_ECNE]             = IP_VS_SCTP_DATA,
 244         [SCTP_CID_ECN_CWR]              = IP_VS_SCTP_DATA,
 245         [SCTP_CID_SHUTDOWN_COMPLETE]    = IP_VS_SCTP_SHUTDOWN_COMPLETE,
 246 };
 247
 248 /* SCTP States:
 249  * See RFC 2960, 4. SCTP Association State Diagram
 250  *
 251  * New states (not in diagram):
 252  * - INIT1 state: use shorter timeout for dropped INIT packets
 253  * - REJECTED state: use shorter timeout if INIT is rejected with ABORT
 254  * - INIT, COOKIE_SENT, COOKIE_REPLIED, COOKIE states: for better debugging
 255  *
 256  * The states are as seen in real server. In the diagram, INIT1, INIT,
 257  * COOKIE_SENT and COOKIE_REPLIED processing happens in CLOSED state.
 258  *
 259  * States as per packets from client (C) and server (S):
 260  *
 261  * Setup of client connection:
 262  * IP_VS_SCTP_S_INIT1: First C:INIT sent, wait for S:INIT-ACK
 263  * IP_VS_SCTP_S_INIT: Next C:INIT sent, wait for S:INIT-ACK
 264  * IP_VS_SCTP_S_COOKIE_SENT: S:INIT-ACK sent, wait for C:COOKIE-ECHO
 265  * IP_VS_SCTP_S_COOKIE_REPLIED: C:COOKIE-ECHO sent, wait for S:COOKIE-ACK
 266  *
 267  * Setup of server connection:
 268  * IP_VS_SCTP_S_COOKIE_WAIT: S:INIT sent, wait for C:INIT-ACK
 269  * IP_VS_SCTP_S_COOKIE: C:INIT-ACK sent, wait for S:COOKIE-ECHO
 270  * IP_VS_SCTP_S_COOKIE_ECHOED: S:COOKIE-ECHO sent, wait for C:COOKIE-ACK
 271  */
 272
 273 #define sNO IP_VS_SCTP_S_NONE
 274 #define sI1 IP_VS_SCTP_S_INIT1
 275 #define sIN IP_VS_SCTP_S_INIT
 276 #define sCS IP_VS_SCTP_S_COOKIE_SENT
 277 #define sCR IP_VS_SCTP_S_COOKIE_REPLIED
 278 #define sCW IP_VS_SCTP_S_COOKIE_WAIT
 279 #define sCO IP_VS_SCTP_S_COOKIE
 280 #define sCE IP_VS_SCTP_S_COOKIE_ECHOED
 281 #define sES IP_VS_SCTP_S_ESTABLISHED
 282 #define sSS IP_VS_SCTP_S_SHUTDOWN_SENT
 283 #define sSR IP_VS_SCTP_S_SHUTDOWN_RECEIVED
 284 #define sSA IP_VS_SCTP_S_SHUTDOWN_ACK_SENT
 285 #define sRJ IP_VS_SCTP_S_REJECTED
 286 #define sCL IP_VS_SCTP_S_CLOSED
 287
 288 static const __u8 sctp_states
 289         [IP_VS_DIR_LAST][IP_VS_SCTP_EVENT_LAST][IP_VS_SCTP_S_LAST] = {
 290         { /* INPUT */
 291 /*        sNO, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL*/
 292 /* d   */{sES, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 293 /* i   */{sI1, sIN, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sIN, sIN},
 294 /* i_a */{sCW, sCW, sCW, sCS, sCR, sCO, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 295 /* c_e */{sCR, sIN, sIN, sCR, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 296 /* c_a */{sES, sI1, sIN, sCS, sCR, sCW, sCO, sES, sES, sSS, sSR, sSA, sRJ, sCL},
 297 /* s   */{sSR, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sSR, sSS, sSR, sSA, sRJ, sCL},
 298 /* s_a */{sCL, sIN, sIN, sCS, sCR, sCW, sCO, sCE, sES, sCL, sSR, sCL, sRJ, sCL},
 299 /* s_c */{sCL, sCL, sCL, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sCL, sRJ, sCL},
 300 /* err */{sCL, sI1, sIN, sCS, sCR, sCW, sCO, sCL, sES, sSS, sSR, sSA, sRJ, sCL},
 301 /* ab  */{sCL, sCL, sCL, sCL, sCL, sRJ, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 302         },
 303         { /* OUTPUT */
 304 /*        sNO, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL*/
 305 /* d   */{sES, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 306 /* i   */{sCW, sCW, sCW, sCW, sCW, sCW, sCW, sCW, sES, sCW, sCW, sCW, sCW, sCW},
 307 /* i_a */{sCS, sCS, sCS, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 308 /* c_e */{sCE, sCE, sCE, sCE, sCE, sCE, sCE, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 309 /* c_a */{sES, sES, sES, sES, sES, sES, sES, sES, sES, sSS, sSR, sSA, sRJ, sCL},
 310 /* s   */{sSS, sSS, sSS, sSS, sSS, sSS, sSS, sSS, sSS, sSS, sSR, sSA, sRJ, sCL},
 311 /* s_a */{sSA, sSA, sSA, sSA, sSA, sCW, sCO, sCE, sES, sSA, sSA, sSA, sRJ, sCL},
 312 /* s_c */{sCL, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 313 /* err */{sCL, sCL, sCL, sCL, sCL, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 314 /* ab  */{sCL, sRJ, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 315         },
 316         { /* INPUT-ONLY */
 317 /*        sNO, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL*/
 318 /* d   */{sES, sI1, sIN, sCS, sCR, sES, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 319 /* i   */{sI1, sIN, sIN, sIN, sIN, sIN, sCO, sCE, sES, sSS, sSR, sSA, sIN, sIN},
 320 /* i_a */{sCE, sCE, sCE, sCE, sCE, sCE, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 321 /* c_e */{sES, sES, sES, sES, sES, sES, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 322 /* c_a */{sES, sI1, sIN, sES, sES, sCW, sES, sES, sES, sSS, sSR, sSA, sRJ, sCL},
 323 /* s   */{sSR, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sSR, sSS, sSR, sSA, sRJ, sCL},
 324 /* s_a */{sCL, sIN, sIN, sCS, sCR, sCW, sCO, sCE, sCL, sCL, sSR, sCL, sRJ, sCL},
 325 /* s_c */{sCL, sCL, sCL, sCL, sCL, sCW, sCO, sCE, sES, sSS, sCL, sCL, sRJ, sCL},
 326 /* err */{sCL, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL},
 327 /* ab  */{sCL, sCL, sCL, sCL, sCL, sRJ, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 328         },
 329 };
 330
 331 #define IP_VS_SCTP_MAX_RTO      ((60 + 1) * HZ)
 332
 333 /* Timeout table[state] */
 334 static const int sctp_timeouts[IP_VS_SCTP_S_LAST + 1] = {
 335         [IP_VS_SCTP_S_NONE]                     = 2 * HZ,
 336         [IP_VS_SCTP_S_INIT1]                    = (0 + 3 + 1) * HZ,
 337         [IP_VS_SCTP_S_INIT]                     = IP_VS_SCTP_MAX_RTO,
 338         [IP_VS_SCTP_S_COOKIE_SENT]              = IP_VS_SCTP_MAX_RTO,
 339         [IP_VS_SCTP_S_COOKIE_REPLIED]           = IP_VS_SCTP_MAX_RTO,
 340         [IP_VS_SCTP_S_COOKIE_WAIT]              = IP_VS_SCTP_MAX_RTO,
 341         [IP_VS_SCTP_S_COOKIE]                   = IP_VS_SCTP_MAX_RTO,
 342         [IP_VS_SCTP_S_COOKIE_ECHOED]            = IP_VS_SCTP_MAX_RTO,
 343         [IP_VS_SCTP_S_ESTABLISHED]              = 15 * 60 * HZ,
 344         [IP_VS_SCTP_S_SHUTDOWN_SENT]            = IP_VS_SCTP_MAX_RTO,
 345         [IP_VS_SCTP_S_SHUTDOWN_RECEIVED]        = IP_VS_SCTP_MAX_RTO,
 346         [IP_VS_SCTP_S_SHUTDOWN_ACK_SENT]        = IP_VS_SCTP_MAX_RTO,
 347         [IP_VS_SCTP_S_REJECTED]                 = (0 + 3 + 1) * HZ,
 348         [IP_VS_SCTP_S_CLOSED]                   = IP_VS_SCTP_MAX_RTO,
 349         [IP_VS_SCTP_S_LAST]                     = 2 * HZ,
 350 };
 351
 352 static const char *sctp_state_name_table[IP_VS_SCTP_S_LAST + 1] = {
 353         [IP_VS_SCTP_S_NONE]                     = "NONE",
 354         [IP_VS_SCTP_S_INIT1]                    = "INIT1",
 355         [IP_VS_SCTP_S_INIT]                     = "INIT",
 356         [IP_VS_SCTP_S_COOKIE_SENT]              = "C-SENT",
 357         [IP_VS_SCTP_S_COOKIE_REPLIED]           = "C-REPLIED",
 358         [IP_VS_SCTP_S_COOKIE_WAIT]              = "C-WAIT",
 359         [IP_VS_SCTP_S_COOKIE]                   = "COOKIE",
 360         [IP_VS_SCTP_S_COOKIE_ECHOED]            = "C-ECHOED",
 361         [IP_VS_SCTP_S_ESTABLISHED]              = "ESTABLISHED",
 362         [IP_VS_SCTP_S_SHUTDOWN_SENT]            = "S-SENT",
 363         [IP_VS_SCTP_S_SHUTDOWN_RECEIVED]        = "S-RECEIVED",
 364         [IP_VS_SCTP_S_SHUTDOWN_ACK_SENT]        = "S-ACK-SENT",
 365         [IP_VS_SCTP_S_REJECTED]                 = "REJECTED",
 366         [IP_VS_SCTP_S_CLOSED]                   = "CLOSED",
 367         [IP_VS_SCTP_S_LAST]                     = "BUG!",
 368 };
 369
 370
 371 static const char *sctp_state_name(int state)
 372 {
 373         if (state >= IP_VS_SCTP_S_LAST)
 374                 return "ERR!";
 375         if (sctp_state_name_table[state])
 376                 return sctp_state_name_table[state];
 377         return "?";
 378 }
 379
 380 static inline void
 381 set_sctp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
 382                 int direction, const struct sk_buff *skb)
 383 {
 384         sctp_chunkhdr_t _sctpch, *sch;
 385         unsigned char chunk_type;
 386         int event, next_state;
 387         int ihl, cofs;
 388
 389 #ifdef CONFIG_IP_VS_IPV6
 390         ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr);
 391 #else
 392         ihl = ip_hdrlen(skb);
 393 #endif
 394
 395         cofs = ihl + sizeof(sctp_sctphdr_t);
 396         sch = skb_header_pointer(skb, cofs, sizeof(_sctpch), &_sctpch);
 397         if (sch == NULL)
 398                 return;
 399
 400         chunk_type = sch->type;
 401         /*
 402          * Section 3: Multiple chunks can be bundled into one SCTP packet
 403          * up to the MTU size, except for the INIT, INIT ACK, and
 404          * SHUTDOWN COMPLETE chunks. These chunks MUST NOT be bundled with
 405          * any other chunk in a packet.
 406          *
 407          * Section 3.3.7: DATA chunks MUST NOT be bundled with ABORT. Control
 408          * chunks (except for INIT, INIT ACK, and SHUTDOWN COMPLETE) MAY be
 409          * bundled with an ABORT, but they MUST be placed before the ABORT
 410          * in the SCTP packet or they will be ignored by the receiver.
 411          */
 412         if ((sch->type == SCTP_CID_COOKIE_ECHO) ||
 413             (sch->type == SCTP_CID_COOKIE_ACK)) {
 414                 int clen = ntohs(sch->length);
 415
 416                 if (clen >= sizeof(sctp_chunkhdr_t)) {
 417                         sch = skb_header_pointer(skb, cofs + ALIGN(clen, 4),
 418                                                  sizeof(_sctpch), &_sctpch);
 419                         if (sch && sch->type == SCTP_CID_ABORT)
 420                                 chunk_type = sch->type;
 421                 }
 422         }
 423
 424         event = (chunk_type < sizeof(sctp_events)) ?
 425                 sctp_events[chunk_type] : IP_VS_SCTP_DATA;
 426
 427         /* Update direction to INPUT_ONLY if necessary
 428          * or delete NO_OUTPUT flag if output packet detected
 429          */
 430         if (cp->flags & IP_VS_CONN_F_NOOUTPUT) {
 431                 if (direction == IP_VS_DIR_OUTPUT)
 432                         cp->flags &= ~IP_VS_CONN_F_NOOUTPUT;
 433                 else
 434                         direction = IP_VS_DIR_INPUT_ONLY;
 435         }
 436
 437         next_state = sctp_states[direction][event][cp->state];
 438
 439         if (next_state != cp->state) {
 440                 struct ip_vs_dest *dest = cp->dest;
 441
 442                 IP_VS_DBG_BUF(8, "%s %s  %s:%d->"
 443                                 "%s:%d state: %s->%s conn->refcnt:%d\n",
 444                                 pd->pp->name,
 445                                 ((direction == IP_VS_DIR_OUTPUT) ?
 446                                  "output " : "input "),
 447                                 IP_VS_DBG_ADDR(cp->daf, &cp->daddr),
 448                                 ntohs(cp->dport),
 449                                 IP_VS_DBG_ADDR(cp->af, &cp->caddr),
 450                                 ntohs(cp->cport),
 451                                 sctp_state_name(cp->state),
 452                                 sctp_state_name(next_state),
 453                                 atomic_read(&cp->refcnt));
 454                 if (dest) {
 455                         if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
 456                                 (next_state != IP_VS_SCTP_S_ESTABLISHED)) {
 457                                 atomic_dec(&dest->activeconns);
 458                                 atomic_inc(&dest->inactconns);
 459                                 cp->flags |= IP_VS_CONN_F_INACTIVE;
 460                         } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) &&
 461                                    (next_state == IP_VS_SCTP_S_ESTABLISHED)) {
 462                                 atomic_inc(&dest->activeconns);
 463                                 atomic_dec(&dest->inactconns);
 464                                 cp->flags &= ~IP_VS_CONN_F_INACTIVE;
 465                         }
 466                 }
 467         }
 468         if (likely(pd))
 469                 cp->timeout = pd->timeout_table[cp->state = next_state];
 470         else    /* What to do ? */
 471                 cp->timeout = sctp_timeouts[cp->state = next_state];
 472 }
 473
 474 static void
 475 sctp_state_transition(struct ip_vs_conn *cp, int direction,
 476                 const struct sk_buff *skb, struct ip_vs_proto_data *pd)
 477 {
 478         spin_lock_bh(&cp->lock);
 479         set_sctp_state(pd, cp, direction, skb);
 480         spin_unlock_bh(&cp->lock);
 481 }
 482
 483 static inline __u16 sctp_app_hashkey(__be16 port)
 484 {
 485         return (((__force u16)port >> SCTP_APP_TAB_BITS) ^ (__force u16)port)
 486                 & SCTP_APP_TAB_MASK;
 487 }
 488
 489 static int sctp_register_app(struct net *net, struct ip_vs_app *inc)
 490 {
 491         struct ip_vs_app *i;
 492         __u16 hash;
 493         __be16 port = inc->port;
 494         int ret = 0;
 495         struct netns_ipvs *ipvs = net_ipvs(net);
 496         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(net, IPPROTO_SCTP);
 497
 498         hash = sctp_app_hashkey(port);
 499
 500         list_for_each_entry(i, &ipvs->sctp_apps[hash], p_list) {
 501                 if (i->port == port) {
 502                         ret = -EEXIST;
 503                         goto out;
 504                 }
 505         }
 506         list_add_rcu(&inc->p_list, &ipvs->sctp_apps[hash]);
 507         atomic_inc(&pd->appcnt);
 508 out:
 509
 510         return ret;
 511 }
 512
 513 static void sctp_unregister_app(struct net *net, struct ip_vs_app *inc)
 514 {
 515         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(net, IPPROTO_SCTP);
 516
 517         atomic_dec(&pd->appcnt);
 518         list_del_rcu(&inc->p_list);
 519 }
 520
 521 static int sctp_app_conn_bind(struct ip_vs_conn *cp)
 522 {
 523         struct netns_ipvs *ipvs = net_ipvs(ip_vs_conn_net(cp));
 524         int hash;
 525         struct ip_vs_app *inc;
 526         int result = 0;
 527
 528         /* Default binding: bind app only for NAT */
 529         if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
 530                 return 0;
 531         /* Lookup application incarnations and bind the right one */
 532         hash = sctp_app_hashkey(cp->vport);
 533
 534         rcu_read_lock();
 535         list_for_each_entry_rcu(inc, &ipvs->sctp_apps[hash], p_list) {
 536                 if (inc->port == cp->vport) {
 537                         if (unlikely(!ip_vs_app_inc_get(inc)))
 538                                 break;
 539                         rcu_read_unlock();
 540
 541                         IP_VS_DBG_BUF(9, "%s: Binding conn %s:%u->"
 542                                         "%s:%u to app %s on port %u\n",
 543                                         __func__,
 544                                         IP_VS_DBG_ADDR(cp->af, &cp->caddr),
 545                                         ntohs(cp->cport),
 546                                         IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
 547                                         ntohs(cp->vport),
 548                                         inc->name, ntohs(inc->port));
 549                         cp->app = inc;
 550                         if (inc->init_conn)
 551                                 result = inc->init_conn(inc, cp);
 552                         goto out;
 553                 }
 554         }
 555         rcu_read_unlock();
 556 out:
 557         return result;
 558 }
 559
 560 /* ---------------------------------------------
 561  *   timeouts is netns related now.
 562  * ---------------------------------------------
 563  */
 564 static int __ip_vs_sctp_init(struct net *net, struct ip_vs_proto_data *pd)
 565 {
 566         struct netns_ipvs *ipvs = net_ipvs(net);
 567
 568         ip_vs_init_hash_table(ipvs->sctp_apps, SCTP_APP_TAB_SIZE);
 569         pd->timeout_table = ip_vs_create_timeout_table((int *)sctp_timeouts,
 570                                                         sizeof(sctp_timeouts));
 571         if (!pd->timeout_table)
 572                 return -ENOMEM;
 573         return 0;
 574 }
 575
 576 static void __ip_vs_sctp_exit(struct net *net, struct ip_vs_proto_data *pd)
 577 {
 578         kfree(pd->timeout_table);
 579 }
 580
 581 struct ip_vs_protocol ip_vs_protocol_sctp = {
 582         .name           = "SCTP",
 583         .protocol       = IPPROTO_SCTP,
 584         .num_states     = IP_VS_SCTP_S_LAST,
 585         .dont_defrag    = 0,
 586         .init           = NULL,
 587         .exit           = NULL,
 588         .init_netns     = __ip_vs_sctp_init,
 589         .exit_netns     = __ip_vs_sctp_exit,
 590         .register_app   = sctp_register_app,
 591         .unregister_app = sctp_unregister_app,
 592         .conn_schedule  = sctp_conn_schedule,
 593         .conn_in_get    = ip_vs_conn_in_get_proto,
 594         .conn_out_get   = ip_vs_conn_out_get_proto,
 595         .snat_handler   = sctp_snat_handler,
 596         .dnat_handler   = sctp_dnat_handler,
 597         .csum_check     = sctp_csum_check,
 598         .state_name     = sctp_state_name,
 599         .state_transition = sctp_state_transition,
 600         .app_conn_bind  = sctp_app_conn_bind,
 601         .debug_packet   = ip_vs_tcpudp_debug_packet,
 602         .timeout_change = NULL,
 603 };