[TCP]: rare bad TCP checksum with 2.6.19
[powerpc.git] / net / ipv4 / tcp_output.c
index 061edfa..23e32c8 100644 (file)
@@ -269,14 +269,14 @@ static u16 tcp_select_window(struct sock *sk)
        return new_win;
 }
 
-static void tcp_build_and_update_options(__u32 *ptr, struct tcp_sock *tp,
-                                        __u32 tstamp)
+static void tcp_build_and_update_options(__be32 *ptr, struct tcp_sock *tp,
+                                        __u32 tstamp, __u8 **md5_hash)
 {
        if (tp->rx_opt.tstamp_ok) {
-               *ptr++ = __constant_htonl((TCPOPT_NOP << 24) |
-                                         (TCPOPT_NOP << 16) |
-                                         (TCPOPT_TIMESTAMP << 8) |
-                                         TCPOLEN_TIMESTAMP);
+               *ptr++ = htonl((TCPOPT_NOP << 24) |
+                              (TCPOPT_NOP << 16) |
+                              (TCPOPT_TIMESTAMP << 8) |
+                              TCPOLEN_TIMESTAMP);
                *ptr++ = htonl(tstamp);
                *ptr++ = htonl(tp->rx_opt.ts_recent);
        }
@@ -298,16 +298,29 @@ static void tcp_build_and_update_options(__u32 *ptr, struct tcp_sock *tp,
                        tp->rx_opt.eff_sacks--;
                }
        }
+#ifdef CONFIG_TCP_MD5SIG
+       if (md5_hash) {
+               *ptr++ = htonl((TCPOPT_NOP << 24) |
+                              (TCPOPT_NOP << 16) |
+                              (TCPOPT_MD5SIG << 8) |
+                              TCPOLEN_MD5SIG);
+               *md5_hash = (__u8 *)ptr;
+       }
+#endif
 }
 
 /* Construct a tcp options header for a SYN or SYN_ACK packet.
  * If this is every changed make sure to change the definition of
  * MAX_SYN_SIZE to match the new maximum number of options that you
  * can generate.
+ *
+ * Note - that with the RFC2385 TCP option, we make room for the
+ * 16 byte MD5 hash. This will be filled in later, so the pointer for the
+ * location to be filled is passed back up.
  */
-static void tcp_syn_build_options(__u32 *ptr, int mss, int ts, int sack,
+static void tcp_syn_build_options(__be32 *ptr, int mss, int ts, int sack,
                                  int offer_wscale, int wscale, __u32 tstamp,
-                                 __u32 ts_recent)
+                                 __u32 ts_recent, __u8 **md5_hash)
 {
        /* We always get an MSS option.
         * The option bytes which will be seen in normal data
@@ -325,18 +338,41 @@ static void tcp_syn_build_options(__u32 *ptr, int mss, int ts, int sack,
        *ptr++ = htonl((TCPOPT_MSS << 24) | (TCPOLEN_MSS << 16) | mss);
        if (ts) {
                if(sack)
-                       *ptr++ = __constant_htonl((TCPOPT_SACK_PERM << 24) | (TCPOLEN_SACK_PERM << 16) |
-                                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
+                       *ptr++ = htonl((TCPOPT_SACK_PERM << 24) |
+                                      (TCPOLEN_SACK_PERM << 16) |
+                                      (TCPOPT_TIMESTAMP << 8) |
+                                      TCPOLEN_TIMESTAMP);
                else
-                       *ptr++ = __constant_htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
-                                                 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
+                       *ptr++ = htonl((TCPOPT_NOP << 24) |
+                                      (TCPOPT_NOP << 16) |
+                                      (TCPOPT_TIMESTAMP << 8) |
+                                      TCPOLEN_TIMESTAMP);
                *ptr++ = htonl(tstamp);         /* TSVAL */
                *ptr++ = htonl(ts_recent);      /* TSECR */
        } else if(sack)
-               *ptr++ = __constant_htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
-                                         (TCPOPT_SACK_PERM << 8) | TCPOLEN_SACK_PERM);
+               *ptr++ = htonl((TCPOPT_NOP << 24) |
+                              (TCPOPT_NOP << 16) |
+                              (TCPOPT_SACK_PERM << 8) |
+                              TCPOLEN_SACK_PERM);
        if (offer_wscale)
-               *ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_WINDOW << 16) | (TCPOLEN_WINDOW << 8) | (wscale));
+               *ptr++ = htonl((TCPOPT_NOP << 24) |
+                              (TCPOPT_WINDOW << 16) |
+                              (TCPOLEN_WINDOW << 8) |
+                              (wscale));
+#ifdef CONFIG_TCP_MD5SIG
+       /*
+        * If MD5 is enabled, then we set the option, and include the size
+        * (always 18). The actual MD5 hash is added just before the
+        * packet is sent.
+        */
+       if (md5_hash) {
+               *ptr++ = htonl((TCPOPT_NOP << 24) |
+                              (TCPOPT_NOP << 16) |
+                              (TCPOPT_MD5SIG << 8) |
+                              TCPOLEN_MD5SIG);
+               *md5_hash = (__u8 *) ptr;
+       }
+#endif
 }
 
 /* This routine actually transmits TCP packets queued in by
@@ -357,6 +393,10 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
        struct tcp_sock *tp;
        struct tcp_skb_cb *tcb;
        int tcp_header_size;
+#ifdef CONFIG_TCP_MD5SIG
+       struct tcp_md5sig_key *md5;
+       __u8 *md5_hash_location;
+#endif
        struct tcphdr *th;
        int sysctl_flags;
        int err;
@@ -415,16 +455,25 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
        if (tcp_packets_in_flight(tp) == 0)
                tcp_ca_event(sk, CA_EVENT_TX_START);
 
+#ifdef CONFIG_TCP_MD5SIG
+       /*
+        * Are we doing MD5 on this segment? If so - make
+        * room for it.
+        */
+       md5 = tp->af_specific->md5_lookup(sk, sk);
+       if (md5)
+               tcp_header_size += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
        th = (struct tcphdr *) skb_push(skb, tcp_header_size);
        skb->h.th = th;
-       skb_set_owner_w(skb, sk);
 
        /* Build TCP header and checksum it. */
        th->source              = inet->sport;
        th->dest                = inet->dport;
        th->seq                 = htonl(tcb->seq);
        th->ack_seq             = htonl(tp->rcv_nxt);
-       *(((__u16 *)th) + 6)    = htons(((tcp_header_size >> 2) << 12) |
+       *(((__be16 *)th) + 6)   = htons(((tcp_header_size >> 2) << 12) |
                                        tcb->flags);
 
        if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
@@ -445,20 +494,41 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
        }
 
        if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
-               tcp_syn_build_options((__u32 *)(th + 1),
+               tcp_syn_build_options((__be32 *)(th + 1),
                                      tcp_advertise_mss(sk),
                                      (sysctl_flags & SYSCTL_FLAG_TSTAMPS),
                                      (sysctl_flags & SYSCTL_FLAG_SACK),
                                      (sysctl_flags & SYSCTL_FLAG_WSCALE),
                                      tp->rx_opt.rcv_wscale,
                                      tcb->when,
-                                     tp->rx_opt.ts_recent);
+                                     tp->rx_opt.ts_recent,
+
+#ifdef CONFIG_TCP_MD5SIG
+                                     md5 ? &md5_hash_location :
+#endif
+                                     NULL);
        } else {
-               tcp_build_and_update_options((__u32 *)(th + 1),
-                                            tp, tcb->when);
+               tcp_build_and_update_options((__be32 *)(th + 1),
+                                            tp, tcb->when,
+#ifdef CONFIG_TCP_MD5SIG
+                                            md5 ? &md5_hash_location :
+#endif
+                                            NULL);
                TCP_ECN_send(sk, tp, skb, tcp_header_size);
        }
 
+#ifdef CONFIG_TCP_MD5SIG
+       /* Calculate the MD5 hash, as we have all we need now */
+       if (md5) {
+               tp->af_specific->calc_md5_hash(md5_hash_location,
+                                              md5,
+                                              sk, NULL, NULL,
+                                              skb->h.th,
+                                              sk->sk_protocol,
+                                              skb->len);
+       }
+#endif
+
        icsk->icsk_af_ops->send_check(sk, skb->len, skb);
 
        if (likely(tcb->flags & TCPCB_FLAG_ACK))
@@ -470,19 +540,13 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
        if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)
                TCP_INC_STATS(TCP_MIB_OUTSEGS);
 
-       err = icsk->icsk_af_ops->queue_xmit(skb, 0);
+       err = icsk->icsk_af_ops->queue_xmit(skb, sk, 0);
        if (likely(err <= 0))
                return err;
 
        tcp_enter_cwr(sk);
 
-       /* NET_XMIT_CN is special. It does not guarantee,
-        * that this packet is lost. It tells that device
-        * is about to start to drop packets or already
-        * drops some packets of the same priority and
-        * invokes us to send less aggressively.
-        */
-       return err == NET_XMIT_CN ? 0 : err;
+       return net_xmit_eval(err);
 
 #undef SYSCTL_FLAG_TSTAMPS
 #undef SYSCTL_FLAG_WSCALE
@@ -838,6 +902,11 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
                mss_now -= (TCPOLEN_SACK_BASE_ALIGNED +
                            (tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK));
 
+#ifdef CONFIG_TCP_MD5SIG
+       if (tp->af_specific->md5_lookup(sk, sk))
+               mss_now -= TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
        xmit_size_goal = mss_now;
 
        if (doing_tso) {
@@ -1087,10 +1156,14 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
        u32 send_win, cong_win, limit, in_flight;
 
        if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
-               return 0;
+               goto send_now;
 
        if (icsk->icsk_ca_state != TCP_CA_Open)
-               return 0;
+               goto send_now;
+
+       /* Defer for less than two clock ticks. */
+       if (!tp->tso_deferred && ((jiffies<<1)>>1) - (tp->tso_deferred>>1) > 1)
+               goto send_now;
 
        in_flight = tcp_packets_in_flight(tp);
 
@@ -1106,7 +1179,7 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
 
        /* If a full-sized TSO skb can be sent, do it. */
        if (limit >= 65536)
-               return 0;
+               goto send_now;
 
        if (sysctl_tcp_tso_win_divisor) {
                u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);
@@ -1116,7 +1189,7 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
                 */
                chunk /= sysctl_tcp_tso_win_divisor;
                if (limit >= chunk)
-                       return 0;
+                       goto send_now;
        } else {
                /* Different approach, try not to defer past a single
                 * ACK.  Receiver should ACK every other full sized
@@ -1124,11 +1197,17 @@ static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_
                 * then send now.
                 */
                if (limit > tcp_max_burst(tp) * tp->mss_cache)
-                       return 0;
+                       goto send_now;
        }
 
        /* Ok, it looks like it is advisable to defer.  */
+       tp->tso_deferred = 1 | (jiffies<<1);
+
        return 1;
+
+send_now:
+       tp->tso_deferred = 0;
+       return 0;
 }
 
 /* Create a new MTU probe if we are ready.
@@ -1571,7 +1650,8 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
 
                memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);
 
-               skb->ip_summed = next_skb->ip_summed;
+               if (next_skb->ip_summed == CHECKSUM_PARTIAL)
+                       skb->ip_summed = CHECKSUM_PARTIAL;
 
                if (skb->ip_summed != CHECKSUM_PARTIAL)
                        skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
@@ -2021,6 +2101,10 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
        struct tcphdr *th;
        int tcp_header_size;
        struct sk_buff *skb;
+#ifdef CONFIG_TCP_MD5SIG
+       struct tcp_md5sig_key *md5;
+       __u8 *md5_hash_location;
+#endif
 
        skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC);
        if (skb == NULL)
@@ -2036,6 +2120,13 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
                           (ireq->wscale_ok ? TCPOLEN_WSCALE_ALIGNED : 0) +
                           /* SACK_PERM is in the place of NOP NOP of TS */
                           ((ireq->sack_ok && !ireq->tstamp_ok) ? TCPOLEN_SACKPERM_ALIGNED : 0));
+
+#ifdef CONFIG_TCP_MD5SIG
+       /* Are we doing MD5 on this segment? If so - make room for it */
+       md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req);
+       if (md5)
+               tcp_header_size += TCPOLEN_MD5SIG_ALIGNED;
+#endif
        skb->h.th = th = (struct tcphdr *) skb_push(skb, tcp_header_size);
 
        memset(th, 0, sizeof(struct tcphdr));
@@ -2070,14 +2161,32 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
        th->window = htons(req->rcv_wnd);
 
        TCP_SKB_CB(skb)->when = tcp_time_stamp;
-       tcp_syn_build_options((__u32 *)(th + 1), dst_metric(dst, RTAX_ADVMSS), ireq->tstamp_ok,
+       tcp_syn_build_options((__be32 *)(th + 1), dst_metric(dst, RTAX_ADVMSS), ireq->tstamp_ok,
                              ireq->sack_ok, ireq->wscale_ok, ireq->rcv_wscale,
                              TCP_SKB_CB(skb)->when,
-                             req->ts_recent);
+                             req->ts_recent,
+                             (
+#ifdef CONFIG_TCP_MD5SIG
+                              md5 ? &md5_hash_location :
+#endif
+                              NULL)
+                             );
 
        skb->csum = 0;
        th->doff = (tcp_header_size >> 2);
        TCP_INC_STATS(TCP_MIB_OUTSEGS);
+
+#ifdef CONFIG_TCP_MD5SIG
+       /* Okay, we have all we need - do the md5 hash if needed */
+       if (md5) {
+               tp->af_specific->calc_md5_hash(md5_hash_location,
+                                              md5,
+                                              NULL, dst, req,
+                                              skb->h.th, sk->sk_protocol,
+                                              skb->len);
+       }
+#endif
+
        return skb;
 }
 
@@ -2096,6 +2205,11 @@ static void tcp_connect_init(struct sock *sk)
        tp->tcp_header_len = sizeof(struct tcphdr) +
                (sysctl_tcp_timestamps ? TCPOLEN_TSTAMP_ALIGNED : 0);
 
+#ifdef CONFIG_TCP_MD5SIG
+       if (tp->af_specific->md5_lookup(sk, sk) != NULL)
+               tp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
        /* If user gave his TCP_MAXSEG, record it to clamp */
        if (tp->rx_opt.user_mss)
                tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;