| /* |
| * ip_vs_proto_tcp.c: TCP load balancing support for IPVS |
| * |
| * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> |
| * Julian Anastasov <ja@ssi.bg> |
| * |
| * This program 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 of the License, or (at your option) any later version. |
| * |
| * Changes: Hans Schillstrom <hans.schillstrom@ericsson.com> |
| * |
| * Network name space (netns) aware. |
| * Global data moved to netns i.e struct netns_ipvs |
| * tcp_timeouts table has copy per netns in a hash table per |
| * protocol ip_vs_proto_data and is handled by netns |
| */ |
| |
| #define KMSG_COMPONENT "IPVS" |
| #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| |
| #include <linux/kernel.h> |
| #include <linux/ip.h> |
| #include <linux/tcp.h> /* for tcphdr */ |
| #include <net/ip.h> |
| #include <net/tcp.h> /* for csum_tcpudp_magic */ |
| #include <net/ip6_checksum.h> |
| #include <linux/netfilter.h> |
| #include <linux/netfilter_ipv4.h> |
| |
| #include <net/ip_vs.h> |
| |
| static int |
| tcp_conn_schedule(struct netns_ipvs *ipvs, 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 ip_vs_service *svc; |
| struct tcphdr _tcph, *th; |
| __be16 _ports[2], *ports = NULL; |
| |
| /* In the event of icmp, we're only guaranteed to have the first 8 |
| * bytes of the transport header, so we only check the rest of the |
| * TCP packet for non-ICMP packets |
| */ |
| if (likely(!ip_vs_iph_icmp(iph))) { |
| th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph); |
| if (th) { |
| if (th->rst || !(sysctl_sloppy_tcp(ipvs) || th->syn)) |
| return 1; |
| ports = &th->source; |
| } |
| } else { |
| ports = skb_header_pointer( |
| skb, iph->len, sizeof(_ports), &_ports); |
| } |
| |
| if (!ports) { |
| *verdict = NF_DROP; |
| return 0; |
| } |
| |
| /* No !th->ack check to allow scheduling on SYN+ACK for Active FTP */ |
| rcu_read_lock(); |
| |
| if (likely(!ip_vs_iph_inverse(iph))) |
| svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol, |
| &iph->daddr, ports[1]); |
| else |
| svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol, |
| &iph->saddr, ports[0]); |
| |
| if (svc) { |
| 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 inline void |
| tcp_fast_csum_update(int af, struct tcphdr *tcph, |
| const union nf_inet_addr *oldip, |
| const union nf_inet_addr *newip, |
| __be16 oldport, __be16 newport) |
| { |
| #ifdef CONFIG_IP_VS_IPV6 |
| if (af == AF_INET6) |
| tcph->check = |
| csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6, |
| ip_vs_check_diff2(oldport, newport, |
| ~csum_unfold(tcph->check)))); |
| else |
| #endif |
| tcph->check = |
| csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip, |
| ip_vs_check_diff2(oldport, newport, |
| ~csum_unfold(tcph->check)))); |
| } |
| |
| |
| static inline void |
| tcp_partial_csum_update(int af, struct tcphdr *tcph, |
| const union nf_inet_addr *oldip, |
| const union nf_inet_addr *newip, |
| __be16 oldlen, __be16 newlen) |
| { |
| #ifdef CONFIG_IP_VS_IPV6 |
| if (af == AF_INET6) |
| tcph->check = |
| ~csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6, |
| ip_vs_check_diff2(oldlen, newlen, |
| csum_unfold(tcph->check)))); |
| else |
| #endif |
| tcph->check = |
| ~csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip, |
| ip_vs_check_diff2(oldlen, newlen, |
| csum_unfold(tcph->check)))); |
| } |
| |
| |
| static int |
| tcp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, |
| struct ip_vs_conn *cp, struct ip_vs_iphdr *iph) |
| { |
| struct tcphdr *tcph; |
| unsigned int tcphoff = iph->len; |
| int oldlen; |
| int payload_csum = 0; |
| |
| #ifdef CONFIG_IP_VS_IPV6 |
| if (cp->af == AF_INET6 && iph->fragoffs) |
| return 1; |
| #endif |
| oldlen = skb->len - tcphoff; |
| |
| /* csum_check requires unshared skb */ |
| if (!skb_make_writable(skb, tcphoff+sizeof(*tcph))) |
| 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 */ |
| if (!(ret = ip_vs_app_pkt_out(cp, skb))) |
| return 0; |
| /* ret=2: csum update is needed after payload mangling */ |
| if (ret == 1) |
| oldlen = skb->len - tcphoff; |
| else |
| payload_csum = 1; |
| } |
| |
| tcph = (void *)skb_network_header(skb) + tcphoff; |
| tcph->source = cp->vport; |
| |
| /* Adjust TCP checksums */ |
| if (skb->ip_summed == CHECKSUM_PARTIAL) { |
| tcp_partial_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr, |
| htons(oldlen), |
| htons(skb->len - tcphoff)); |
| } else if (!payload_csum) { |
| /* Only port and addr are changed, do fast csum update */ |
| tcp_fast_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr, |
| cp->dport, cp->vport); |
| if (skb->ip_summed == CHECKSUM_COMPLETE) |
| skb->ip_summed = (cp->app && pp->csum_check) ? |
| CHECKSUM_UNNECESSARY : CHECKSUM_NONE; |
| } else { |
| /* full checksum calculation */ |
| tcph->check = 0; |
| skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); |
| #ifdef CONFIG_IP_VS_IPV6 |
| if (cp->af == AF_INET6) |
| tcph->check = csum_ipv6_magic(&cp->vaddr.in6, |
| &cp->caddr.in6, |
| skb->len - tcphoff, |
| cp->protocol, skb->csum); |
| else |
| #endif |
| tcph->check = csum_tcpudp_magic(cp->vaddr.ip, |
| cp->caddr.ip, |
| skb->len - tcphoff, |
| cp->protocol, |
| skb->csum); |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| |
| IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n", |
| pp->name, tcph->check, |
| (char*)&(tcph->check) - (char*)tcph); |
| } |
| return 1; |
| } |
| |
| |
| static int |
| tcp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, |
| struct ip_vs_conn *cp, struct ip_vs_iphdr *iph) |
| { |
| struct tcphdr *tcph; |
| unsigned int tcphoff = iph->len; |
| int oldlen; |
| int payload_csum = 0; |
| |
| #ifdef CONFIG_IP_VS_IPV6 |
| if (cp->af == AF_INET6 && iph->fragoffs) |
| return 1; |
| #endif |
| oldlen = skb->len - tcphoff; |
| |
| /* csum_check requires unshared skb */ |
| if (!skb_make_writable(skb, tcphoff+sizeof(*tcph))) |
| 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; |
| |
| /* |
| * Attempt ip_vs_app call. |
| * It will fix ip_vs_conn and iph ack_seq stuff |
| */ |
| if (!(ret = ip_vs_app_pkt_in(cp, skb))) |
| return 0; |
| /* ret=2: csum update is needed after payload mangling */ |
| if (ret == 1) |
| oldlen = skb->len - tcphoff; |
| else |
| payload_csum = 1; |
| } |
| |
| tcph = (void *)skb_network_header(skb) + tcphoff; |
| tcph->dest = cp->dport; |
| |
| /* |
| * Adjust TCP checksums |
| */ |
| if (skb->ip_summed == CHECKSUM_PARTIAL) { |
| tcp_partial_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr, |
| htons(oldlen), |
| htons(skb->len - tcphoff)); |
| } else if (!payload_csum) { |
| /* Only port and addr are changed, do fast csum update */ |
| tcp_fast_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr, |
| cp->vport, cp->dport); |
| if (skb->ip_summed == CHECKSUM_COMPLETE) |
| skb->ip_summed = (cp->app && pp->csum_check) ? |
| CHECKSUM_UNNECESSARY : CHECKSUM_NONE; |
| } else { |
| /* full checksum calculation */ |
| tcph->check = 0; |
| skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); |
| #ifdef CONFIG_IP_VS_IPV6 |
| if (cp->af == AF_INET6) |
| tcph->check = csum_ipv6_magic(&cp->caddr.in6, |
| &cp->daddr.in6, |
| skb->len - tcphoff, |
| cp->protocol, skb->csum); |
| else |
| #endif |
| tcph->check = csum_tcpudp_magic(cp->caddr.ip, |
| cp->daddr.ip, |
| skb->len - tcphoff, |
| cp->protocol, |
| skb->csum); |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| } |
| return 1; |
| } |
| |
| |
| static int |
| tcp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp) |
| { |
| unsigned int tcphoff; |
| |
| #ifdef CONFIG_IP_VS_IPV6 |
| if (af == AF_INET6) |
| tcphoff = sizeof(struct ipv6hdr); |
| else |
| #endif |
| tcphoff = ip_hdrlen(skb); |
| |
| switch (skb->ip_summed) { |
| case CHECKSUM_NONE: |
| skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); |
| case CHECKSUM_COMPLETE: |
| #ifdef CONFIG_IP_VS_IPV6 |
| if (af == AF_INET6) { |
| if (csum_ipv6_magic(&ipv6_hdr(skb)->saddr, |
| &ipv6_hdr(skb)->daddr, |
| skb->len - tcphoff, |
| ipv6_hdr(skb)->nexthdr, |
| skb->csum)) { |
| IP_VS_DBG_RL_PKT(0, af, pp, skb, 0, |
| "Failed checksum for"); |
| return 0; |
| } |
| } else |
| #endif |
| if (csum_tcpudp_magic(ip_hdr(skb)->saddr, |
| ip_hdr(skb)->daddr, |
| skb->len - tcphoff, |
| ip_hdr(skb)->protocol, |
| skb->csum)) { |
| IP_VS_DBG_RL_PKT(0, af, pp, skb, 0, |
| "Failed checksum for"); |
| return 0; |
| } |
| break; |
| default: |
| /* No need to checksum. */ |
| break; |
| } |
| |
| return 1; |
| } |
| |
| |
| #define TCP_DIR_INPUT 0 |
| #define TCP_DIR_OUTPUT 4 |
| #define TCP_DIR_INPUT_ONLY 8 |
| |
| static const int tcp_state_off[IP_VS_DIR_LAST] = { |
| [IP_VS_DIR_INPUT] = TCP_DIR_INPUT, |
| [IP_VS_DIR_OUTPUT] = TCP_DIR_OUTPUT, |
| [IP_VS_DIR_INPUT_ONLY] = TCP_DIR_INPUT_ONLY, |
| }; |
| |
| /* |
| * Timeout table[state] |
| */ |
| static const int tcp_timeouts[IP_VS_TCP_S_LAST+1] = { |
| [IP_VS_TCP_S_NONE] = 2*HZ, |
| [IP_VS_TCP_S_ESTABLISHED] = 15*60*HZ, |
| [IP_VS_TCP_S_SYN_SENT] = 2*60*HZ, |
| [IP_VS_TCP_S_SYN_RECV] = 1*60*HZ, |
| [IP_VS_TCP_S_FIN_WAIT] = 2*60*HZ, |
| [IP_VS_TCP_S_TIME_WAIT] = 2*60*HZ, |
| [IP_VS_TCP_S_CLOSE] = 10*HZ, |
| [IP_VS_TCP_S_CLOSE_WAIT] = 60*HZ, |
| [IP_VS_TCP_S_LAST_ACK] = 30*HZ, |
| [IP_VS_TCP_S_LISTEN] = 2*60*HZ, |
| [IP_VS_TCP_S_SYNACK] = 120*HZ, |
| [IP_VS_TCP_S_LAST] = 2*HZ, |
| }; |
| |
| static const char *const tcp_state_name_table[IP_VS_TCP_S_LAST+1] = { |
| [IP_VS_TCP_S_NONE] = "NONE", |
| [IP_VS_TCP_S_ESTABLISHED] = "ESTABLISHED", |
| [IP_VS_TCP_S_SYN_SENT] = "SYN_SENT", |
| [IP_VS_TCP_S_SYN_RECV] = "SYN_RECV", |
| [IP_VS_TCP_S_FIN_WAIT] = "FIN_WAIT", |
| [IP_VS_TCP_S_TIME_WAIT] = "TIME_WAIT", |
| [IP_VS_TCP_S_CLOSE] = "CLOSE", |
| [IP_VS_TCP_S_CLOSE_WAIT] = "CLOSE_WAIT", |
| [IP_VS_TCP_S_LAST_ACK] = "LAST_ACK", |
| [IP_VS_TCP_S_LISTEN] = "LISTEN", |
| [IP_VS_TCP_S_SYNACK] = "SYNACK", |
| [IP_VS_TCP_S_LAST] = "BUG!", |
| }; |
| |
| #define sNO IP_VS_TCP_S_NONE |
| #define sES IP_VS_TCP_S_ESTABLISHED |
| #define sSS IP_VS_TCP_S_SYN_SENT |
| #define sSR IP_VS_TCP_S_SYN_RECV |
| #define sFW IP_VS_TCP_S_FIN_WAIT |
| #define sTW IP_VS_TCP_S_TIME_WAIT |
| #define sCL IP_VS_TCP_S_CLOSE |
| #define sCW IP_VS_TCP_S_CLOSE_WAIT |
| #define sLA IP_VS_TCP_S_LAST_ACK |
| #define sLI IP_VS_TCP_S_LISTEN |
| #define sSA IP_VS_TCP_S_SYNACK |
| |
| struct tcp_states_t { |
| int next_state[IP_VS_TCP_S_LAST]; |
| }; |
| |
| static const char * tcp_state_name(int state) |
| { |
| if (state >= IP_VS_TCP_S_LAST) |
| return "ERR!"; |
| return tcp_state_name_table[state] ? tcp_state_name_table[state] : "?"; |
| } |
| |
| static struct tcp_states_t tcp_states [] = { |
| /* INPUT */ |
| /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ |
| /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }}, |
| /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sTW }}, |
| /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }}, |
| /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sSR }}, |
| |
| /* OUTPUT */ |
| /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ |
| /*syn*/ {{sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI, sSR }}, |
| /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }}, |
| /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }}, |
| /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }}, |
| |
| /* INPUT-ONLY */ |
| /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ |
| /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }}, |
| /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }}, |
| /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }}, |
| /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }}, |
| }; |
| |
| static struct tcp_states_t tcp_states_dos [] = { |
| /* INPUT */ |
| /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ |
| /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSA }}, |
| /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sSA }}, |
| /*ack*/ {{sES, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI, sSA }}, |
| /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }}, |
| |
| /* OUTPUT */ |
| /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ |
| /*syn*/ {{sSS, sES, sSS, sSA, sSS, sSS, sSS, sSS, sSS, sLI, sSA }}, |
| /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }}, |
| /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }}, |
| /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }}, |
| |
| /* INPUT-ONLY */ |
| /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ |
| /*syn*/ {{sSA, sES, sES, sSR, sSA, sSA, sSA, sSA, sSA, sSA, sSA }}, |
| /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }}, |
| /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }}, |
| /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }}, |
| }; |
| |
| static void tcp_timeout_change(struct ip_vs_proto_data *pd, int flags) |
| { |
| int on = (flags & 1); /* secure_tcp */ |
| |
| /* |
| ** FIXME: change secure_tcp to independent sysctl var |
| ** or make it per-service or per-app because it is valid |
| ** for most if not for all of the applications. Something |
| ** like "capabilities" (flags) for each object. |
| */ |
| pd->tcp_state_table = (on ? tcp_states_dos : tcp_states); |
| } |
| |
| static inline int tcp_state_idx(struct tcphdr *th) |
| { |
| if (th->rst) |
| return 3; |
| if (th->syn) |
| return 0; |
| if (th->fin) |
| return 1; |
| if (th->ack) |
| return 2; |
| return -1; |
| } |
| |
| static inline void |
| set_tcp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp, |
| int direction, struct tcphdr *th) |
| { |
| int state_idx; |
| int new_state = IP_VS_TCP_S_CLOSE; |
| int state_off = tcp_state_off[direction]; |
| |
| /* |
| * Update state offset to INPUT_ONLY if necessary |
| * or delete NO_OUTPUT flag if output packet detected |
| */ |
| if (cp->flags & IP_VS_CONN_F_NOOUTPUT) { |
| if (state_off == TCP_DIR_OUTPUT) |
| cp->flags &= ~IP_VS_CONN_F_NOOUTPUT; |
| else |
| state_off = TCP_DIR_INPUT_ONLY; |
| } |
| |
| if ((state_idx = tcp_state_idx(th)) < 0) { |
| IP_VS_DBG(8, "tcp_state_idx=%d!!!\n", state_idx); |
| goto tcp_state_out; |
| } |
| |
| new_state = |
| pd->tcp_state_table[state_off+state_idx].next_state[cp->state]; |
| |
| tcp_state_out: |
| if (new_state != cp->state) { |
| struct ip_vs_dest *dest = cp->dest; |
| |
| IP_VS_DBG_BUF(8, "%s %s [%c%c%c%c] %s:%d->" |
| "%s:%d state: %s->%s conn->refcnt:%d\n", |
| pd->pp->name, |
| ((state_off == TCP_DIR_OUTPUT) ? |
| "output " : "input "), |
| th->syn ? 'S' : '.', |
| th->fin ? 'F' : '.', |
| th->ack ? 'A' : '.', |
| th->rst ? 'R' : '.', |
| IP_VS_DBG_ADDR(cp->daf, &cp->daddr), |
| ntohs(cp->dport), |
| IP_VS_DBG_ADDR(cp->af, &cp->caddr), |
| ntohs(cp->cport), |
| tcp_state_name(cp->state), |
| tcp_state_name(new_state), |
| atomic_read(&cp->refcnt)); |
| |
| if (dest) { |
| if (!(cp->flags & IP_VS_CONN_F_INACTIVE) && |
| (new_state != IP_VS_TCP_S_ESTABLISHED)) { |
| atomic_dec(&dest->activeconns); |
| atomic_inc(&dest->inactconns); |
| cp->flags |= IP_VS_CONN_F_INACTIVE; |
| } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) && |
| (new_state == IP_VS_TCP_S_ESTABLISHED)) { |
| atomic_inc(&dest->activeconns); |
| atomic_dec(&dest->inactconns); |
| cp->flags &= ~IP_VS_CONN_F_INACTIVE; |
| } |
| } |
| } |
| |
| if (likely(pd)) |
| cp->timeout = pd->timeout_table[cp->state = new_state]; |
| else /* What to do ? */ |
| cp->timeout = tcp_timeouts[cp->state = new_state]; |
| } |
| |
| /* |
| * Handle state transitions |
| */ |
| static void |
| tcp_state_transition(struct ip_vs_conn *cp, int direction, |
| const struct sk_buff *skb, |
| struct ip_vs_proto_data *pd) |
| { |
| struct tcphdr _tcph, *th; |
| |
| #ifdef CONFIG_IP_VS_IPV6 |
| int ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr); |
| #else |
| int ihl = ip_hdrlen(skb); |
| #endif |
| |
| th = skb_header_pointer(skb, ihl, sizeof(_tcph), &_tcph); |
| if (th == NULL) |
| return; |
| |
| spin_lock_bh(&cp->lock); |
| set_tcp_state(pd, cp, direction, th); |
| spin_unlock_bh(&cp->lock); |
| } |
| |
| static inline __u16 tcp_app_hashkey(__be16 port) |
| { |
| return (((__force u16)port >> TCP_APP_TAB_BITS) ^ (__force u16)port) |
| & TCP_APP_TAB_MASK; |
| } |
| |
| |
| static int tcp_register_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc) |
| { |
| struct ip_vs_app *i; |
| __u16 hash; |
| __be16 port = inc->port; |
| int ret = 0; |
| struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_TCP); |
| |
| hash = tcp_app_hashkey(port); |
| |
| list_for_each_entry(i, &ipvs->tcp_apps[hash], p_list) { |
| if (i->port == port) { |
| ret = -EEXIST; |
| goto out; |
| } |
| } |
| list_add_rcu(&inc->p_list, &ipvs->tcp_apps[hash]); |
| atomic_inc(&pd->appcnt); |
| |
| out: |
| return ret; |
| } |
| |
| |
| static void |
| tcp_unregister_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc) |
| { |
| struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_TCP); |
| |
| atomic_dec(&pd->appcnt); |
| list_del_rcu(&inc->p_list); |
| } |
| |
| |
| static int |
| tcp_app_conn_bind(struct ip_vs_conn *cp) |
| { |
| struct netns_ipvs *ipvs = cp->ipvs; |
| int hash; |
| struct ip_vs_app *inc; |
| int result = 0; |
| |
| /* Default binding: bind app only for NAT */ |
| if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) |
| return 0; |
| |
| /* Lookup application incarnations and bind the right one */ |
| hash = tcp_app_hashkey(cp->vport); |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(inc, &ipvs->tcp_apps[hash], p_list) { |
| if (inc->port == cp->vport) { |
| if (unlikely(!ip_vs_app_inc_get(inc))) |
| break; |
| rcu_read_unlock(); |
| |
| IP_VS_DBG_BUF(9, "%s(): Binding conn %s:%u->" |
| "%s:%u to app %s on port %u\n", |
| __func__, |
| IP_VS_DBG_ADDR(cp->af, &cp->caddr), |
| ntohs(cp->cport), |
| IP_VS_DBG_ADDR(cp->af, &cp->vaddr), |
| ntohs(cp->vport), |
| inc->name, ntohs(inc->port)); |
| |
| cp->app = inc; |
| if (inc->init_conn) |
| result = inc->init_conn(inc, cp); |
| goto out; |
| } |
| } |
| rcu_read_unlock(); |
| |
| out: |
| return result; |
| } |
| |
| |
| /* |
| * Set LISTEN timeout. (ip_vs_conn_put will setup timer) |
| */ |
| void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp) |
| { |
| struct ip_vs_proto_data *pd = ip_vs_proto_data_get(cp->ipvs, IPPROTO_TCP); |
| |
| spin_lock_bh(&cp->lock); |
| cp->state = IP_VS_TCP_S_LISTEN; |
| cp->timeout = (pd ? pd->timeout_table[IP_VS_TCP_S_LISTEN] |
| : tcp_timeouts[IP_VS_TCP_S_LISTEN]); |
| spin_unlock_bh(&cp->lock); |
| } |
| |
| /* --------------------------------------------- |
| * timeouts is netns related now. |
| * --------------------------------------------- |
| */ |
| static int __ip_vs_tcp_init(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd) |
| { |
| ip_vs_init_hash_table(ipvs->tcp_apps, TCP_APP_TAB_SIZE); |
| pd->timeout_table = ip_vs_create_timeout_table((int *)tcp_timeouts, |
| sizeof(tcp_timeouts)); |
| if (!pd->timeout_table) |
| return -ENOMEM; |
| pd->tcp_state_table = tcp_states; |
| return 0; |
| } |
| |
| static void __ip_vs_tcp_exit(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd) |
| { |
| kfree(pd->timeout_table); |
| } |
| |
| |
| struct ip_vs_protocol ip_vs_protocol_tcp = { |
| .name = "TCP", |
| .protocol = IPPROTO_TCP, |
| .num_states = IP_VS_TCP_S_LAST, |
| .dont_defrag = 0, |
| .init = NULL, |
| .exit = NULL, |
| .init_netns = __ip_vs_tcp_init, |
| .exit_netns = __ip_vs_tcp_exit, |
| .register_app = tcp_register_app, |
| .unregister_app = tcp_unregister_app, |
| .conn_schedule = tcp_conn_schedule, |
| .conn_in_get = ip_vs_conn_in_get_proto, |
| .conn_out_get = ip_vs_conn_out_get_proto, |
| .snat_handler = tcp_snat_handler, |
| .dnat_handler = tcp_dnat_handler, |
| .csum_check = tcp_csum_check, |
| .state_name = tcp_state_name, |
| .state_transition = tcp_state_transition, |
| .app_conn_bind = tcp_app_conn_bind, |
| .debug_packet = ip_vs_tcpudp_debug_packet, |
| .timeout_change = tcp_timeout_change, |
| }; |