Allow tcp_parse_options to consult dst entry

We need tcp_parse_options to be aware of dst_entry to
take into account per dst_entry TCP options settings

Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 56 insertions, 42 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 03a49c703377..740d09be8e2d 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -409,7 +409,8 @@ extern int			tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
 
 extern void                     tcp_parse_options(struct sk_buff *skb,
                                                   struct tcp_options_received *opt_rx,
-                                                  int estab);
+                                                  int estab,
+                                                  struct dst_entry *dst);
 
 extern u8                       *tcp_parse_md5sig_option(struct tcphdr *th);
 
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 5ec678ad70ef..3146cc401748 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -276,13 +276,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 
         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV);
 
-        /* check for timestamp cookie support */
-        memset(&tcp_opt, 0, sizeof(tcp_opt));
-        tcp_parse_options(skb, &tcp_opt, 0);
-
-        if (tcp_opt.saw_tstamp)
-                cookie_check_timestamp(&tcp_opt);
-
         ret = NULL;
         req = inet_reqsk_alloc(&tcp_request_sock_ops); /* for safety */
         if (!req)
@@ -298,12 +291,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
         ireq->loc_addr          = ip_hdr(skb)->daddr;
         ireq->rmt_addr          = ip_hdr(skb)->saddr;
         ireq->ecn_ok            = 0;
-        ireq->snd_wscale        = tcp_opt.snd_wscale;
-        ireq->rcv_wscale        = tcp_opt.rcv_wscale;
-        ireq->sack_ok           = tcp_opt.sack_ok;
-        ireq->wscale_ok         = tcp_opt.wscale_ok;
-        ireq->tstamp_ok         = tcp_opt.saw_tstamp;
-        req->ts_recent          = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
 
         /* We throwed the options of the initial SYN away, so we hope
          * the ACK carries the same options again (see RFC1122 4.2.3.8)
@@ -352,6 +339,20 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
                 }
         }
 
+        /* check for timestamp cookie support */
+        memset(&tcp_opt, 0, sizeof(tcp_opt));
+        tcp_parse_options(skb, &tcp_opt, 0, &rt->u.dst);
+
+        if (tcp_opt.saw_tstamp)
+                cookie_check_timestamp(&tcp_opt);
+
+        ireq->snd_wscale        = tcp_opt.snd_wscale;
+        ireq->rcv_wscale        = tcp_opt.rcv_wscale;
+        ireq->sack_ok           = tcp_opt.sack_ok;
+        ireq->wscale_ok         = tcp_opt.wscale_ok;
+        ireq->tstamp_ok         = tcp_opt.saw_tstamp;
+        req->ts_recent          = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
+
         /* Try to redo what tcp_v4_send_synack did. */
         req->window_clamp = tp->window_clamp ? :dst_metric(&rt->u.dst, RTAX_WINDOW);
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a0c3700bae3a..c7625005486d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3698,12 +3698,14 @@ old_ack:
  * the fast version below fails.
  */
 void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
-                       int estab)
+                       int estab,  struct dst_entry *dst)
 {
         unsigned char *ptr;
         struct tcphdr *th = tcp_hdr(skb);
         int length = (th->doff * 4) - sizeof(struct tcphdr);
 
+        BUG_ON(!estab && !dst);
+
         ptr = (unsigned char *)(th + 1);
         opt_rx->saw_tstamp = 0;
 
@@ -3820,7 +3822,7 @@ static int tcp_fast_parse_options(struct sk_buff *skb, struct tcphdr *th,
                 if (tcp_parse_aligned_timestamp(tp, th))
                         return 1;
         }
-        tcp_parse_options(skb, &tp->rx_opt, 1);
+        tcp_parse_options(skb, &tp->rx_opt, 1, NULL);
         return 1;
 }
 
@@ -5364,8 +5366,9 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
         struct tcp_sock *tp = tcp_sk(sk);
         struct inet_connection_sock *icsk = inet_csk(sk);
         int saved_clamp = tp->rx_opt.mss_clamp;
+        struct dst_entry *dst = __sk_dst_get(sk);
 
-        tcp_parse_options(skb, &tp->rx_opt, 0);
+        tcp_parse_options(skb, &tp->rx_opt, 0, dst);
 
         if (th->ack) {
                 /* rfc793:
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index a4a3390a5287..657ae334f125 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1257,11 +1257,21 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
         tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
 #endif
 
+        ireq = inet_rsk(req);
+        ireq->loc_addr = daddr;
+        ireq->rmt_addr = saddr;
+        ireq->no_srccheck = inet_sk(sk)->transparent;
+        ireq->opt = tcp_v4_save_options(sk, skb);
+
+        dst = inet_csk_route_req(sk, req);
+        if(!dst)
+                goto drop_and_free;
+
         tcp_clear_options(&tmp_opt);
         tmp_opt.mss_clamp = 536;
         tmp_opt.user_mss  = tcp_sk(sk)->rx_opt.user_mss;
 
-        tcp_parse_options(skb, &tmp_opt, 0);
+        tcp_parse_options(skb, &tmp_opt, 0, dst);
 
         if (want_cookie && !tmp_opt.saw_tstamp)
                 tcp_clear_options(&tmp_opt);
@@ -1270,14 +1280,8 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 
         tcp_openreq_init(req, &tmp_opt, skb);
 
-        ireq = inet_rsk(req);
-        ireq->loc_addr = daddr;
-        ireq->rmt_addr = saddr;
-        ireq->no_srccheck = inet_sk(sk)->transparent;
-        ireq->opt = tcp_v4_save_options(sk, skb);
-
         if (security_inet_conn_request(sk, skb, req))
-                goto drop_and_free;
+                goto drop_and_release;
 
         if (!want_cookie)
                 TCP_ECN_create_request(req, tcp_hdr(skb));
@@ -1302,7 +1306,6 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
                  */
                 if (tmp_opt.saw_tstamp &&
                     tcp_death_row.sysctl_tw_recycle &&
-                    (dst = inet_csk_route_req(sk, req)) != NULL &&
                     (peer = rt_get_peer((struct rtable *)dst)) != NULL &&
                     peer->v4daddr == saddr) {
                         if (get_seconds() < peer->tcp_ts_stamp + TCP_PAWS_MSL &&
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 015e7c67dc88..463d51b53d37 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -102,7 +102,7 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
 
         if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) {
                 tmp_opt.tstamp_ok = 1;
-                tcp_parse_options(skb, &tmp_opt, 1);
+                tcp_parse_options(skb, &tmp_opt, 1, NULL);
 
                 if (tmp_opt.saw_tstamp) {
                         tmp_opt.ts_recent       = tcptw->tw_ts_recent;
@@ -500,10 +500,11 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
         int paws_reject = 0;
         struct tcp_options_received tmp_opt;
         struct sock *child;
+        struct dst_entry *dst = inet_csk_route_req(sk, req);
 
         tmp_opt.saw_tstamp = 0;
         if (th->doff > (sizeof(struct tcphdr)>>2)) {
-                tcp_parse_options(skb, &tmp_opt, 0);
+                tcp_parse_options(skb, &tmp_opt, 0, dst);
 
                 if (tmp_opt.saw_tstamp) {
                         tmp_opt.ts_recent = req->ts_recent;
@@ -516,6 +517,8 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
                 }
         }
 
+        dst_release(dst);
+
         /* Check for pure retransmitted SYN. */
         if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn &&
             flg == TCP_FLAG_SYN &&
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index c46da533888a..612fc53e0bb9 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -184,13 +184,6 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 
         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV);
 
-        /* check for timestamp cookie support */
-        memset(&tcp_opt, 0, sizeof(tcp_opt));
-        tcp_parse_options(skb, &tcp_opt, 0);
-
-        if (tcp_opt.saw_tstamp)
-                cookie_check_timestamp(&tcp_opt);
-
         ret = NULL;
         req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
         if (!req)
@@ -224,12 +217,6 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
         req->expires = 0UL;
         req->retrans = 0;
         ireq->ecn_ok            = 0;
-        ireq->snd_wscale        = tcp_opt.snd_wscale;
-        ireq->rcv_wscale        = tcp_opt.rcv_wscale;
-        ireq->sack_ok           = tcp_opt.sack_ok;
-        ireq->wscale_ok         = tcp_opt.wscale_ok;
-        ireq->tstamp_ok         = tcp_opt.saw_tstamp;
-        req->ts_recent          = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
         treq->rcv_isn = ntohl(th->seq) - 1;
         treq->snt_isn = cookie;
 
@@ -265,6 +252,21 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
                         goto out_free;
         }
 
+        /* check for timestamp cookie support */
+        memset(&tcp_opt, 0, sizeof(tcp_opt));
+        tcp_parse_options(skb, &tcp_opt, 0, dst);
+
+        if (tcp_opt.saw_tstamp)
+                cookie_check_timestamp(&tcp_opt);
+
+        req->ts_recent          = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
+
+        ireq->snd_wscale        = tcp_opt.snd_wscale;
+        ireq->rcv_wscale        = tcp_opt.rcv_wscale;
+        ireq->sack_ok           = tcp_opt.sack_ok;
+        ireq->wscale_ok         = tcp_opt.wscale_ok;
+        ireq->tstamp_ok         = tcp_opt.saw_tstamp;
+
         req->window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW);
         tcp_select_initial_window(tcp_full_space(sk), req->mss,
                                   &req->rcv_wnd, &req->window_clamp,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index c54ec3615ded..34925f089e07 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1167,6 +1167,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
         struct tcp_sock *tp = tcp_sk(sk);
         struct request_sock *req = NULL;
         __u32 isn = TCP_SKB_CB(skb)->when;
+        struct dst_entry *dst = __sk_dst_get(sk);
 #ifdef CONFIG_SYN_COOKIES
         int want_cookie = 0;
 #else
@@ -1205,7 +1206,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
         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);
+        tcp_parse_options(skb, &tmp_opt, 0, dst);
 
         if (want_cookie && !tmp_opt.saw_tstamp)
                 tcp_clear_options(&tmp_opt);