ip_vs_proto_sctp.rar_For Real

#include <linux/kernel.h> #include <linux/ip.h> #include <linux/sctp.h> #include <net/ip.h> #include <net/ip6_checksum.h> #include <linux/netfilter.h> #include <linux/netfilter_ipv4.h> #include <net/sctp/checksum.h> #include <net/ip_vs.h> static int sctp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd, int *verdict, struct ip_vs_conn **cpp, struct ip_vs_iphdr *iph) { struct net *net; struct ip_vs_service *svc; struct netns_ipvs *ipvs; sctp_chunkhdr_t _schunkh, *sch; sctp_sctphdr_t *sh, _sctph; sh = skb_header_pointer(skb, iph->len, sizeof(_sctph), &_sctph); if (sh == NULL) { *verdict = NF_DROP; return 0; } sch = skb_header_pointer(skb, iph->len + sizeof(sctp_sctphdr_t), sizeof(_schunkh), &_schunkh); if (sch == NULL) { *verdict = NF_DROP; return 0; } net = skb_net(skb); ipvs = net_ipvs(net); rcu_read_lock(); if ((sch->type == SCTP_CID_INIT || sysctl_sloppy_sctp(ipvs)) && (svc = ip_vs_service_find(net, af, skb->mark, iph->protocol, &iph->daddr, sh->dest))) { int ignored; if (ip_vs_todrop(ipvs)) { /* * It seems that we are very loaded. * We have to drop this packet :( */ rcu_read_unlock(); *verdict = NF_DROP; return 0; } /* * Let the virtual server select a real server for the * incoming connection, and create a connection entry. */ *cpp = ip_vs_schedule(svc, skb, pd, &ignored, iph); if (!*cpp && ignored <= 0) { if (!ignored) *verdict = ip_vs_leave(svc, skb, pd, iph); else *verdict = NF_DROP; rcu_read_unlock(); return 0; } } rcu_read_unlock(); /* NF_ACCEPT */ return 1; } static void sctp_nat_csum(struct sk_buff *skb, sctp_sctphdr_t *sctph, unsigned int sctphoff) { sctph->checksum = sctp_compute_cksum(skb, sctphoff); skb->ip_summed = CHECKSUM_UNNECESSARY; } static int sctp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, struct ip_vs_conn *cp, struct ip_vs_iphdr *iph) { sctp_sctphdr_t *sctph; unsigned int sctphoff = iph->len; bool payload_csum = false; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6 && iph->fragoffs) return 1; #endif /* csum_check requires unshared skb */ if (!skb_make_writable(skb, sctphoff + sizeof(*sctph))) return 0; if (unlikely(cp->app != NULL)) { int ret; /* Some checks before mangling */ if (pp->csum_check && !pp->csum_check(cp->af, skb, pp)) return 0; /* Call application helper if needed */ ret = ip_vs_app_pkt_out(cp, skb); if (ret == 0) return 0; /* ret=2: csum update is needed after payload mangling */ if (ret == 2) payload_csum = true; } sctph = (void *) skb_network_header(skb) + sctphoff; /* Only update csum if we really have to */ if (sctph->source != cp->vport || payload_csum || skb->ip_summed == CHECKSUM_PARTIAL) { sctph->source = cp->vport; sctp_nat_csum(skb, sctph, sctphoff); } else { skb->ip_summed = CHECKSUM_UNNECESSARY; } return 1; } static int sctp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, struct ip_vs_conn *cp, struct ip_vs_iphdr *iph) { sctp_sctphdr_t *sctph; unsigned int sctphoff = iph->len; bool payload_csum = false; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6 && iph->fragoffs) return 1; #endif /* csum_check requires unshared skb */ if (!skb_make_writable(skb, sctphoff + sizeof(*sctph))) return 0; if (unlikely(cp->app != NULL)) { int ret; /* Some checks before mangling */ if (pp->csum_check && !pp->csum_check(cp->af, skb, pp)) return 0; /* Call application helper if needed */ ret = ip_vs_app_pkt_in(cp, skb); if (ret == 0) return 0; /* ret=2: csum update is needed after payload mangling */ if (ret == 2) payload_csum = true; } sctph = (void *) skb_network_header(skb) + sctphoff; /* Only update csum if we really have to */ if (sctph->dest != cp->dport || payload_csum || (skb->ip_summed == CHECKSUM_PARTIAL && !(skb_dst(skb)->dev->features & NETIF_F_SCTP_CSUM))) { sctph->dest = cp->dport; sctp_nat_csum(skb, sctph, sctphoff); } else if (skb->ip_summed != CHECKSUM_PARTIAL) { skb->ip_summed = CHECKSUM_UNNECESSARY; } return 1; } static int sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp) { unsigned int sctphoff; struct sctphdr *sh, _sctph; __le32 cmp, val; #ifdef CONFIG_IP_VS_IPV6 if (af == AF_INET6) sctphoff = sizeof(struct ipv6hdr); else #endif sctphoff = ip_hdrlen(skb); sh = skb_header_pointer(skb, sctphoff, sizeof(_sctph), &_sctph); if (sh == NULL) return 0; cmp = sh->checksum; val = sctp_compute_cksum(skb, sctphoff); if (val != cmp) { /* CRC failure, dump it. */ IP_VS_DBG_RL_PKT(0, af, pp, skb, 0, "Failed checksum for"); return 0; } return 1; } enum ipvs_sctp_event_t { IP_VS_SCTP_DATA = 0, /* DATA, SACK, HEARTBEATs */ IP_VS_SCTP_INIT, IP_VS_SCTP_INIT_ACK, IP_VS_SCTP_COOKIE_ECHO, IP_VS_SCTP_COOKIE_ACK, IP_VS_SCTP_SHUTDOWN, IP_VS_SCTP_SHUTDOWN_ACK, IP_VS_SCTP_SHUTDOWN_COMPLETE, IP_VS_SCTP_ERROR, IP_VS_SCTP_ABORT, IP_VS_SCTP_EVENT_LAST }; /* RFC 2960, 3.2 Chunk Field Descriptions */ static __u8 sctp_events[] = { [SCTP_CID_DATA] = IP_VS_SCTP_DATA, [SCTP_CID_INIT] = IP_VS_SCTP_INIT, [SCTP_CID_INIT_ACK] = IP_VS_SCTP_INIT_ACK, [SCTP_CID_SACK] = IP_VS_SCTP_DATA, [SCTP_CID_HEARTBEAT] = IP_VS_SCTP_DATA, [SCTP_CID_HEARTBEAT_ACK] = IP_VS_SCTP_DATA, [SCTP_CID_ABORT] = IP_VS_SCTP_ABORT, [SCTP_CID_SHUTDOWN] = IP_VS_SCTP_SHUTDOWN, [SCTP_CID_SHUTDOWN_ACK] = IP_VS_SCTP_SHUTDOWN_ACK, [SCTP_CID_ERROR] = IP_VS_SCTP_ERROR, [SCTP_CID_COOKIE_ECHO] = IP_VS_SCTP_COOKIE_ECHO, [SCTP_CID_COOKIE_ACK] = IP_VS_SCTP_COOKIE_ACK, [SCTP_CID_ECN_ECNE] = IP_VS_SCTP_DATA, [SCTP_CID_ECN_CWR] = IP_VS_SCTP_DATA, [SCTP_CID_SHUTDOWN_COMPLETE] = IP_VS_SCTP_SHUTDOWN_COMPLETE, }; /* SCTP States: * See RFC 2960, 4. SCTP Association State Diagram * * New states (not in diagram): * - INIT1 state: use shorter timeout for dropped INIT packets * - REJECTED state: use shorter timeout if INIT is rejected with ABORT * - INIT, COOKIE_SENT, COOKIE_REPLIED, COOKIE states: for better debugging * * The states are as seen in real server. In the diagram, INIT1, INIT, * COOKIE_SENT and COOKIE_REPLIED processing happens in CLOSED state. * * States as per packets from client (C) and server (S): * * Setup of client connection: * IP_VS_SCTP_S_INIT1: First C:INIT sent, wait for S:INIT-ACK * IP_VS_SCTP_S_INIT: Next C:INIT sent, wait for S:INIT-ACK * IP_VS_SCTP_S_COOKIE_SENT: S:INIT-ACK sent, wait for C:COOKIE-ECHO * IP_VS_SCTP_S_COOKIE_REPLIED: C:COOKIE-ECHO sent, wait for S:COOKIE-ACK * * Setup of server connection: * IP_VS_SCTP_S_COOKIE_WAIT: S:INIT sent, wait for C:INIT-ACK * IP_VS_SCTP_S_COOKIE: C:INIT-ACK sent, wait for S:COOKIE-ECHO * IP_VS_SCTP_S_COOKIE_ECHOED: S:COOKIE-ECHO sent, wait for C:COOKIE-ACK */ #define sNO IP_VS_SCTP_S_NONE #define sI1 IP_VS_SCTP_S_INIT1 #define sIN IP_VS_SCTP_S_INIT #define sCS IP_VS_SCTP_S_COOKIE_SENT #define sCR IP_VS_SCTP_S_COOKIE_REPLIED #define sCW IP_VS_SCTP_S_COOKIE_WAIT #define sCO IP_VS_SCTP_S_COOKIE #define sCE IP_VS_SCTP_S_COOKIE_ECHOED #define sES IP_VS_SCTP_S_ESTABLISHED #define sSS IP_VS_SCTP_S_SHUTDOWN_SENT #define sSR IP_VS_SCTP_S_SHUTDOWN_RECEIVED #define sSA IP_VS_SCTP_S_SHUTDOWN_ACK_SENT #define sRJ IP_VS_SCTP_S_REJECTED #define sCL IP_VS_SCTP_S_CLOSED static const __u8 sctp_states [IP_VS_DIR_LAST][IP_VS_SCTP_EVENT_LAST][IP_VS_SCTP_S_LAST] = { { /* INPUT */ /* sNO, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL*/ /* d */{sES, sI1, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL}, /* i */{sI1, sIN, sIN, sCS, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sIN, sIN}, /* i_a */{sCW, sCW, sCW, sCS, sCR, sCO, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL}, /* c_e */{sCR, sIN, sIN, sCR, sCR, sCW, sCO, sCE, sES, sSS, sSR, sSA, sRJ, sCL}, /* c_a */{sES, sI1, sIN, sCS, sCR, sCW, sCO, sES, sES, sSS, sSR, sSA, sRJ, sCL}, /* s */{sSR, sI1, sIN, sCS, sCR, sCW, sC