diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 2faef339d8f2..c811300b0b0c 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -256,16 +256,6 @@ static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk) return inet_sk(__sk)->pinet6; } -static inline struct request_sock *inet6_reqsk_alloc(struct request_sock_ops *ops) -{ - struct request_sock *req = reqsk_alloc(ops); - - if (req) - inet_rsk(req)->pktopts = NULL; - - return req; -} - static inline struct raw6_sock *raw6_sk(const struct sock *sk) { return (struct raw6_sock *)sk; diff --git a/include/linux/tcp.h b/include/linux/tcp.h index a0513210798f..fa5258f322e7 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -111,10 +111,7 @@ struct tcp_request_sock_ops; struct tcp_request_sock { struct inet_request_sock req; -#ifdef CONFIG_TCP_MD5SIG - /* Only used by TCP MD5 Signature so far. */ const struct tcp_request_sock_ops *af_specific; -#endif struct sock *listener; /* needed for TFO */ u32 rcv_isn; u32 snt_isn; diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index b1edf17bec01..a829b77523cf 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -88,8 +88,10 @@ struct inet_request_sock { acked : 1, no_srccheck: 1; kmemcheck_bitfield_end(flags); - struct ip_options_rcu *opt; - struct sk_buff *pktopts; + union { + struct ip_options_rcu *opt; + struct sk_buff *pktopts; + }; u32 ir_mark; }; diff --git a/include/net/tcp.h b/include/net/tcp.h index 06a3023080c0..0d5389aecf18 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -493,14 +493,8 @@ static inline u32 tcp_cookie_time(void) u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, u16 *mssp); -__u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mss); -#else -static inline __u32 cookie_v4_init_sequence(struct sock *sk, - struct sk_buff *skb, - __u16 *mss) -{ - return 0; -} +__u32 cookie_v4_init_sequence(struct sock *sk, const struct sk_buff *skb, + __u16 *mss); #endif __u32 cookie_init_timestamp(struct request_sock *req); @@ -516,13 +510,6 @@ u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, const struct tcphdr *th, u16 *mssp); __u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mss); -#else -static inline __u32 cookie_v6_init_sequence(struct sock *sk, - struct sk_buff *skb, - __u16 *mss) -{ - return 0; -} #endif /* tcp_output.c */ @@ -1586,6 +1573,11 @@ int tcp4_proc_init(void); void tcp4_proc_exit(void); #endif +int tcp_rtx_synack(struct sock *sk, struct request_sock *req); +int tcp_conn_request(struct request_sock_ops *rsk_ops, + const struct tcp_request_sock_ops *af_ops, + struct sock *sk, struct sk_buff *skb); + /* TCP af-specific functions */ struct tcp_sock_af_ops { #ifdef CONFIG_TCP_MD5SIG @@ -1603,6 +1595,7 @@ struct tcp_sock_af_ops { }; struct tcp_request_sock_ops { + u16 mss_clamp; #ifdef CONFIG_TCP_MD5SIG struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk, struct request_sock *req); @@ -1612,8 +1605,39 @@ struct tcp_request_sock_ops { const struct request_sock *req, const struct sk_buff *skb); #endif + void (*init_req)(struct request_sock *req, struct sock *sk, + struct sk_buff *skb); +#ifdef CONFIG_SYN_COOKIES + __u32 (*cookie_init_seq)(struct sock *sk, const struct sk_buff *skb, + __u16 *mss); +#endif + struct dst_entry *(*route_req)(struct sock *sk, struct flowi *fl, + const struct request_sock *req, + bool *strict); + __u32 (*init_seq)(const struct sk_buff *skb); + int (*send_synack)(struct sock *sk, struct dst_entry *dst, + struct flowi *fl, struct request_sock *req, + u16 queue_mapping, struct tcp_fastopen_cookie *foc); + void (*queue_hash_add)(struct sock *sk, struct request_sock *req, + const unsigned long timeout); }; +#ifdef CONFIG_SYN_COOKIES +static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, + struct sock *sk, struct sk_buff *skb, + __u16 *mss) +{ + return ops->cookie_init_seq(sk, skb, mss); +} +#else +static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, + struct sock *sk, struct sk_buff *skb, + __u16 *mss) +{ + return 0; +} +#endif + int tcpv4_offload_init(void); void tcp_v4_init(void); diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c index 4db3c2a1679c..04cb17d4b0ce 100644 --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -386,7 +386,7 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb) if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) goto drop; - req = inet6_reqsk_alloc(&dccp6_request_sock_ops); + req = inet_reqsk_alloc(&dccp6_request_sock_ops); if (req == NULL) goto drop; diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index c86624b36a62..c0c75688896e 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -170,7 +170,8 @@ u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, } EXPORT_SYMBOL_GPL(__cookie_v4_init_sequence); -__u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp) +__u32 cookie_v4_init_sequence(struct sock *sk, const struct sk_buff *skb, + __u16 *mssp) { const struct iphdr *iph = ip_hdr(skb); const struct tcphdr *th = tcp_hdr(skb); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index b5c23756965a..97e48d60c4e8 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5877,3 +5877,151 @@ discard: return 0; } EXPORT_SYMBOL(tcp_rcv_state_process); + +static inline void pr_drop_req(struct request_sock *req, __u16 port, int family) +{ + struct inet_request_sock *ireq = inet_rsk(req); + + if (family == AF_INET) + LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("drop open request from %pI4/%u\n"), + &ireq->ir_rmt_addr, port); + else + LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("drop open request from %pI6/%u\n"), + &ireq->ir_v6_rmt_addr, port); +} + +int tcp_conn_request(struct request_sock_ops *rsk_ops, + const struct tcp_request_sock_ops *af_ops, + struct sock *sk, struct sk_buff *skb) +{ + struct tcp_options_received tmp_opt; + struct request_sock *req; + struct tcp_sock *tp = tcp_sk(sk); + struct dst_entry *dst = NULL; + __u32 isn = TCP_SKB_CB(skb)->when; + bool want_cookie = false, fastopen; + struct flowi fl; + struct tcp_fastopen_cookie foc = { .len = -1 }; + int err; + + + /* TW buckets are converted to open requests without + * limitations, they conserve resources and peer is + * evidently real one. + */ + if ((sysctl_tcp_syncookies == 2 || + inet_csk_reqsk_queue_is_full(sk)) && !isn) { + want_cookie = tcp_syn_flood_action(sk, skb, rsk_ops->slab_name); + if (!want_cookie) + goto drop; + } + + + /* Accept backlog is full. If we have already queued enough + * of warm entries in syn queue, drop request. It is better than + * clogging syn queue with openreqs with exponentially increasing + * timeout. + */ + if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) { + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); + goto drop; + } + + req = inet_reqsk_alloc(rsk_ops); + if (!req) + goto drop; + + tcp_rsk(req)->af_specific = af_ops; + + tcp_clear_options(&tmp_opt); + tmp_opt.mss_clamp = af_ops->mss_clamp; + tmp_opt.user_mss = tp->rx_opt.user_mss; + tcp_parse_options(skb, &tmp_opt, 0, want_cookie ? NULL : &foc); + + if (want_cookie && !tmp_opt.saw_tstamp) + tcp_clear_options(&tmp_opt); + + tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; + tcp_openreq_init(req, &tmp_opt, skb, sk); + + af_ops->init_req(req, sk, skb); + + if (security_inet_conn_request(sk, skb, req)) + goto drop_and_free; + + if (!want_cookie || tmp_opt.tstamp_ok) + TCP_ECN_create_request(req, skb, sock_net(sk)); + + if (want_cookie) { + isn = cookie_init_sequence(af_ops, sk, skb, &req->mss); + req->cookie_ts = tmp_opt.tstamp_ok; + } else if (!isn) { + /* VJ's idea. We save last timestamp seen + * from the destination in peer table, when entering + * state TIME-WAIT, and check against it before + * accepting new connection request. + * + * If "isn" is not zero, this request hit alive + * timewait bucket, so that all the necessary checks + * are made in the function processing timewait state. + */ + if (tmp_opt.saw_tstamp && tcp_death_row.sysctl_tw_recycle) { + bool strict; + + dst = af_ops->route_req(sk, &fl, req, &strict); + if (dst && strict && + !tcp_peer_is_proven(req, dst, true)) { + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED); + goto drop_and_release; + } + } + /* Kill the following clause, if you dislike this way. */ + else if (!sysctl_tcp_syncookies && + (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) < + (sysctl_max_syn_backlog >> 2)) && + !tcp_peer_is_proven(req, dst, false)) { + /* Without syncookies last quarter of + * backlog is filled with destinations, + * proven to be alive. + * It means that we continue to communicate + * to destinations, already remembered + * to the moment of synflood. + */ + pr_drop_req(req, ntohs(tcp_hdr(skb)->source), + rsk_ops->family); + goto drop_and_release; + } + + isn = af_ops->init_seq(skb); + } + if (!dst) { + dst = af_ops->route_req(sk, &fl, req, NULL); + if (!dst) + goto drop_and_free; + } + + tcp_rsk(req)->snt_isn = isn; + tcp_openreq_init_rwin(req, sk, dst); + fastopen = !want_cookie && + tcp_try_fastopen(sk, skb, req, &foc, dst); + err = af_ops->send_synack(sk, dst, &fl, req, + skb_get_queue_mapping(skb), &foc); + if (!fastopen) { + if (err || want_cookie) + goto drop_and_free; + + tcp_rsk(req)->listener = NULL; + af_ops->queue_hash_add(sk, req, TCP_TIMEOUT_INIT); + } + + return 0; + +drop_and_release: + dst_release(dst); +drop_and_free: + reqsk_free(req); +drop: + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); + return 0; +} +EXPORT_SYMBOL(tcp_conn_request); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 180336d47df6..5dfebd2f2e38 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -99,7 +99,7 @@ static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, struct inet_hashinfo tcp_hashinfo; EXPORT_SYMBOL(tcp_hashinfo); -static inline __u32 tcp_v4_init_sequence(const struct sk_buff *skb) +static __u32 tcp_v4_init_sequence(const struct sk_buff *skb) { return secure_tcp_sequence_number(ip_hdr(skb)->daddr, ip_hdr(skb)->saddr, @@ -814,6 +814,7 @@ static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, * socket. */ static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst, + struct flowi *fl, struct request_sock *req, u16 queue_mapping, struct tcp_fastopen_cookie *foc) @@ -844,17 +845,6 @@ static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst, return err; } -static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req) -{ - int res = tcp_v4_send_synack(sk, NULL, req, 0, NULL); - - if (!res) { - TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); - } - return res; -} - /* * IPv4 request_sock destructor. */ @@ -1237,160 +1227,68 @@ static bool tcp_v4_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb) #endif +static void tcp_v4_init_req(struct request_sock *req, struct sock *sk, + struct sk_buff *skb) +{ + struct inet_request_sock *ireq = inet_rsk(req); + + ireq->ir_loc_addr = ip_hdr(skb)->daddr; + ireq->ir_rmt_addr = ip_hdr(skb)->saddr; + ireq->no_srccheck = inet_sk(sk)->transparent; + ireq->opt = tcp_v4_save_options(skb); +} + +static struct dst_entry *tcp_v4_route_req(struct sock *sk, struct flowi *fl, + const struct request_sock *req, + bool *strict) +{ + struct dst_entry *dst = inet_csk_route_req(sk, &fl->u.ip4, req); + + if (strict) { + if (fl->u.ip4.daddr == inet_rsk(req)->ir_rmt_addr) + *strict = true; + else + *strict = false; + } + + return dst; +} + struct request_sock_ops tcp_request_sock_ops __read_mostly = { .family = PF_INET, .obj_size = sizeof(struct tcp_request_sock), - .rtx_syn_ack = tcp_v4_rtx_synack, + .rtx_syn_ack = tcp_rtx_synack, .send_ack = tcp_v4_reqsk_send_ack, .destructor = tcp_v4_reqsk_destructor, .send_reset = tcp_v4_send_reset, .syn_ack_timeout = tcp_syn_ack_timeout, }; -#ifdef CONFIG_TCP_MD5SIG static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { + .mss_clamp = TCP_MSS_DEFAULT, +#ifdef CONFIG_TCP_MD5SIG .md5_lookup = tcp_v4_reqsk_md5_lookup, .calc_md5_hash = tcp_v4_md5_hash_skb, -}; #endif + .init_req = tcp_v4_init_req, +#ifdef CONFIG_SYN_COOKIES + .cookie_init_seq = cookie_v4_init_sequence, +#endif + .route_req = tcp_v4_route_req, + .init_seq = tcp_v4_init_sequence, + .send_synack = tcp_v4_send_synack, + .queue_hash_add = inet_csk_reqsk_queue_hash_add, +}; int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) { - struct tcp_options_received tmp_opt; - struct request_sock *req; - struct inet_request_sock *ireq; - struct tcp_sock *tp = tcp_sk(sk); - struct dst_entry *dst = NULL; - __be32 saddr = ip_hdr(skb)->saddr; - __be32 daddr = ip_hdr(skb)->daddr; - __u32 isn = TCP_SKB_CB(skb)->when; - bool want_cookie = false, fastopen; - struct flowi4 fl4; - struct tcp_fastopen_cookie foc = { .len = -1 }; - int err; - /* Never answer to SYNs send to broadcast or multicast */ if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) goto drop; - /* TW buckets are converted to open requests without - * limitations, they conserve resources and peer is - * evidently real one. - */ - if ((sysctl_tcp_syncookies == 2 || - inet_csk_reqsk_queue_is_full(sk)) && !isn) { - want_cookie = tcp_syn_flood_action(sk, skb, "TCP"); - if (!want_cookie) - goto drop; - } + return tcp_conn_request(&tcp_request_sock_ops, + &tcp_request_sock_ipv4_ops, sk, skb); - /* Accept backlog is full. If we have already queued enough - * of warm entries in syn queue, drop request. It is better than - * clogging syn queue with openreqs with exponentially increasing - * timeout. - */ - if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) { - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); - goto drop; - } - - req = inet_reqsk_alloc(&tcp_request_sock_ops); - if (!req) - goto drop; - -#ifdef CONFIG_TCP_MD5SIG - tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops; -#endif - - tcp_clear_options(&tmp_opt); - tmp_opt.mss_clamp = TCP_MSS_DEFAULT; - tmp_opt.user_mss = tp->rx_opt.user_mss; - tcp_parse_options(skb, &tmp_opt, 0, want_cookie ? NULL : &foc); - - if (want_cookie && !tmp_opt.saw_tstamp) - tcp_clear_options(&tmp_opt); - - tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; - tcp_openreq_init(req, &tmp_opt, skb, sk); - - ireq = inet_rsk(req); - ireq->ir_loc_addr = daddr; - ireq->ir_rmt_addr = saddr; - ireq->no_srccheck = inet_sk(sk)->transparent; - ireq->opt = tcp_v4_save_options(skb); - - if (security_inet_conn_request(sk, skb, req)) - goto drop_and_free; - - if (!want_cookie || tmp_opt.tstamp_ok) - TCP_ECN_create_request(req, skb, sock_net(sk)); - - if (want_cookie) { - isn = cookie_v4_init_sequence(sk, skb, &req->mss); - req->cookie_ts = tmp_opt.tstamp_ok; - } else if (!isn) { - /* VJ's idea. We save last timestamp seen - * from the destination in peer table, when entering - * state TIME-WAIT, and check against it before - * accepting new connection request. - * - * If "isn" is not zero, this request hit alive - * timewait bucket, so that all the necessary checks - * are made in the function processing timewait state. - */ - if (tmp_opt.saw_tstamp && - tcp_death_row.sysctl_tw_recycle && - (dst = inet_csk_route_req(sk, &fl4, req)) != NULL && - fl4.daddr == saddr) { - if (!tcp_peer_is_proven(req, dst, true)) { - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED); - goto drop_and_release; - } - } - /* Kill the following clause, if you dislike this way. */ - else if (!sysctl_tcp_syncookies && - (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) < - (sysctl_max_syn_backlog >> 2)) && - !tcp_peer_is_proven(req, dst, false)) { - /* Without syncookies last quarter of - * backlog is filled with destinations, - * proven to be alive. - * It means that we continue to communicate - * to destinations, already remembered - * to the moment of synflood. - */ - LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("drop open request from %pI4/%u\n"), - &saddr, ntohs(tcp_hdr(skb)->source)); - goto drop_and_release; - } - - isn = tcp_v4_init_sequence(skb); - } - if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL) - goto drop_and_free; - - tcp_rsk(req)->snt_isn = isn; - tcp_rsk(req)->snt_synack = tcp_time_stamp; - tcp_openreq_init_rwin(req, sk, dst); - fastopen = !want_cookie && - tcp_try_fastopen(sk, skb, req, &foc, dst); - err = tcp_v4_send_synack(sk, dst, req, - skb_get_queue_mapping(skb), &foc); - if (!fastopen) { - if (err || want_cookie) - goto drop_and_free; - - tcp_rsk(req)->snt_synack = tcp_time_stamp; - tcp_rsk(req)->listener = NULL; - inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); - } - - return 0; - -drop_and_release: - dst_release(dst); -drop_and_free: - reqsk_free(req); drop: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); return 0; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index d92bce0ea24e..f8f2a944a1ce 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3299,3 +3299,18 @@ void tcp_send_probe0(struct sock *sk) TCP_RTO_MAX); } } + +int tcp_rtx_synack(struct sock *sk, struct request_sock *req) +{ + const struct tcp_request_sock_ops *af_ops = tcp_rsk(req)->af_specific; + struct flowi fl; + int res; + + res = af_ops->send_synack(sk, NULL, &fl, req, 0, NULL); + if (!res) { + TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); + } + return res; +} +EXPORT_SYMBOL(tcp_rtx_synack); diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index a822b880689b..83cea1d39466 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -187,7 +187,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) goto out; ret = NULL; - req = inet6_reqsk_alloc(&tcp6_request_sock_ops); + req = inet_reqsk_alloc(&tcp6_request_sock_ops); if (!req) goto out; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 08ae3da0db4a..bc24ee21339a 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -470,13 +470,14 @@ out: static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst, - struct flowi6 *fl6, + struct flowi *fl, struct request_sock *req, u16 queue_mapping, struct tcp_fastopen_cookie *foc) { struct inet_request_sock *ireq = inet_rsk(req); struct ipv6_pinfo *np = inet6_sk(sk); + struct flowi6 *fl6 = &fl->u.ip6; struct sk_buff *skb; int err = -ENOMEM; @@ -497,24 +498,14 @@ static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst, skb_set_queue_mapping(skb, queue_mapping); err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass); err = net_xmit_eval(err); + if (!tcp_rsk(req)->snt_synack && !err) + tcp_rsk(req)->snt_synack = tcp_time_stamp; } done: return err; } -static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req) -{ - struct flowi6 fl6; - int res; - - res = tcp_v6_send_synack(sk, NULL, &fl6, req, 0, NULL); - if (!res) { - TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); - } - return res; -} static void tcp_v6_reqsk_destructor(struct request_sock *req) { @@ -718,22 +709,66 @@ static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb) } #endif +static void tcp_v6_init_req(struct request_sock *req, struct sock *sk, + struct sk_buff *skb) +{ + struct inet_request_sock *ireq = inet_rsk(req); + struct ipv6_pinfo *np = inet6_sk(sk); + + ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; + ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; + + ireq->ir_iif = sk->sk_bound_dev_if; + + /* So that link locals have meaning */ + if (!sk->sk_bound_dev_if && + ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) + ireq->ir_iif = inet6_iif(skb); + + if (!TCP_SKB_CB(skb)->when && + (ipv6_opt_accepted(sk, skb) || np->rxopt.bits.rxinfo || + np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim || + np->rxopt.bits.rxohlim || np->repflow)) { + atomic_inc(&skb->users); + ireq->pktopts = skb; + } +} + +static struct dst_entry *tcp_v6_route_req(struct sock *sk, struct flowi *fl, + const struct request_sock *req, + bool *strict) +{ + if (strict) + *strict = true; + return inet6_csk_route_req(sk, &fl->u.ip6, req); +} + struct request_sock_ops tcp6_request_sock_ops __read_mostly = { .family = AF_INET6, .obj_size = sizeof(struct tcp6_request_sock), - .rtx_syn_ack = tcp_v6_rtx_synack, + .rtx_syn_ack = tcp_rtx_synack, .send_ack = tcp_v6_reqsk_send_ack, .destructor = tcp_v6_reqsk_destructor, .send_reset = tcp_v6_send_reset, .syn_ack_timeout = tcp_syn_ack_timeout, }; -#ifdef CONFIG_TCP_MD5SIG static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { + .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - + sizeof(struct ipv6hdr), +#ifdef CONFIG_TCP_MD5SIG .md5_lookup = tcp_v6_reqsk_md5_lookup, .calc_md5_hash = tcp_v6_md5_hash_skb, -}; #endif + .init_req = tcp_v6_init_req, +#ifdef CONFIG_SYN_COOKIES + .cookie_init_seq = cookie_v6_init_sequence, +#endif + .route_req = tcp_v6_route_req, + .init_seq = tcp_v6_init_sequence, + .send_synack = tcp_v6_send_synack, + .queue_hash_add = inet6_csk_reqsk_queue_hash_add, +}; static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, @@ -973,152 +1008,17 @@ static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb) return sk; } -/* FIXME: this is substantially similar to the ipv4 code. - * Can some kind of merge be done? -- erics - */ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) { - struct tcp_options_received tmp_opt; - struct request_sock *req; - struct inet_request_sock *ireq; - struct ipv6_pinfo *np = inet6_sk(sk); - struct tcp_sock *tp = tcp_sk(sk); - __u32 isn = TCP_SKB_CB(skb)->when; - struct dst_entry *dst = NULL; - struct tcp_fastopen_cookie foc = { .len = -1 }; - bool want_cookie = false, fastopen; - struct flowi6 fl6; - int err; - if (skb->protocol == htons(ETH_P_IP)) return tcp_v4_conn_request(sk, skb); if (!ipv6_unicast_destination(skb)) goto drop; - if ((sysctl_tcp_syncookies == 2 || - inet_csk_reqsk_queue_is_full(sk)) && !isn) { - want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6"); - if (!want_cookie) - goto drop; - } + return tcp_conn_request(&tcp6_request_sock_ops, + &tcp_request_sock_ipv6_ops, sk, skb); - if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) { - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); - goto drop; - } - - req = inet6_reqsk_alloc(&tcp6_request_sock_ops); - if (req == NULL) - goto drop; - -#ifdef CONFIG_TCP_MD5SIG - tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops; -#endif - - tcp_clear_options(&tmp_opt); - tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); - tmp_opt.user_mss = tp->rx_opt.user_mss; - tcp_parse_options(skb, &tmp_opt, 0, want_cookie ? NULL : &foc); - - if (want_cookie && !tmp_opt.saw_tstamp) - tcp_clear_options(&tmp_opt); - - tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; - tcp_openreq_init(req, &tmp_opt, skb, sk); - - ireq = inet_rsk(req); - ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; - ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; - if (!want_cookie || tmp_opt.tstamp_ok) - TCP_ECN_create_request(req, skb, sock_net(sk)); - - ireq->ir_iif = sk->sk_bound_dev_if; - - /* So that link locals have meaning */ - if (!sk->sk_bound_dev_if && - ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) - ireq->ir_iif = inet6_iif(skb); - - if (!isn) { - if (ipv6_opt_accepted(sk, skb) || - np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || - np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim || - np->repflow) { - atomic_inc(&skb->users); - ireq->pktopts = skb; - } - - if (want_cookie) { - isn = cookie_v6_init_sequence(sk, skb, &req->mss); - req->cookie_ts = tmp_opt.tstamp_ok; - goto have_isn; - } - - /* VJ's idea. We save last timestamp seen - * from the destination in peer table, when entering - * state TIME-WAIT, and check against it before - * accepting new connection request. - * - * If "isn" is not zero, this request hit alive - * timewait bucket, so that all the necessary checks - * are made in the function processing timewait state. - */ - if (tmp_opt.saw_tstamp && - tcp_death_row.sysctl_tw_recycle && - (dst = inet6_csk_route_req(sk, &fl6, req)) != NULL) { - if (!tcp_peer_is_proven(req, dst, true)) { - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED); - goto drop_and_release; - } - } - /* Kill the following clause, if you dislike this way. */ - else if (!sysctl_tcp_syncookies && - (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) < - (sysctl_max_syn_backlog >> 2)) && - !tcp_peer_is_proven(req, dst, false)) { - /* Without syncookies last quarter of - * backlog is filled with destinations, - * proven to be alive. - * It means that we continue to communicate - * to destinations, already remembered - * to the moment of synflood. - */ - LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n", - &ireq->ir_v6_rmt_addr, ntohs(tcp_hdr(skb)->source)); - goto drop_and_release; - } - - isn = tcp_v6_init_sequence(skb); - } -have_isn: - - if (security_inet_conn_request(sk, skb, req)) - goto drop_and_release; - - if (!dst && (dst = inet6_csk_route_req(sk, &fl6, req)) == NULL) - goto drop_and_free; - - tcp_rsk(req)->snt_isn = isn; - tcp_rsk(req)->snt_synack = tcp_time_stamp; - tcp_openreq_init_rwin(req, sk, dst); - fastopen = !want_cookie && - tcp_try_fastopen(sk, skb, req, &foc, dst); - err = tcp_v6_send_synack(sk, dst, &fl6, req, - skb_get_queue_mapping(skb), &foc); - if (!fastopen) { - if (err || want_cookie) - goto drop_and_free; - - tcp_rsk(req)->listener = NULL; - inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); - } - return 0; - -drop_and_release: - dst_release(dst); -drop_and_free: - reqsk_free(req); drop: NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); return 0; /* don't send reset */