1 files changed, 94 insertions, 64 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 4ff3b6dc74fc..803cbfe82fbc 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -34,6 +34,8 @@
  *
  */
 
+#define pr_fmt(fmt) "TCP: " fmt
+
 #include <net/tcp.h>
 
 #include <linux/compiler.h>
@@ -78,9 +80,8 @@ static void tcp_event_new_data_sent(struct sock *sk, const struct sk_buff *skb)
 		tp->frto_counter = 3;
 
 	tp->packets_out += tcp_skb_pcount(skb);
-	if (!prior_packets)
-		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
-					  inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
+	if (!prior_packets || tp->early_retrans_delayed)
+		tcp_rearm_rto(sk);
 }
 
 /* SND.NXT, if window was not shrunk.
@@ -369,7 +370,7 @@ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
 	TCP_SKB_CB(skb)->end_seq = seq;
 }
 
-static inline int tcp_urg_mode(const struct tcp_sock *tp)
+static inline bool tcp_urg_mode(const struct tcp_sock *tp)
 {
 	return tp->snd_una != tp->snd_up;
 }
@@ -563,13 +564,13 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
 /* Compute TCP options for SYN packets. This is not the final
  * network wire format yet.
  */
-static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
+static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
 				struct tcp_out_options *opts,
 				struct tcp_md5sig_key **md5)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_cookie_values *cvp = tp->cookie_values;
-	unsigned remaining = MAX_TCP_OPTION_SPACE;
+	unsigned int remaining = MAX_TCP_OPTION_SPACE;
 	u8 cookie_size = (!tp->rx_opt.cookie_out_never && cvp != NULL) ?
 			 tcp_cookie_size_check(cvp->cookie_desired) :
 			 0;
@@ -663,15 +664,15 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
 }
 
 /* Set up TCP options for SYN-ACKs. */
-static unsigned tcp_synack_options(struct sock *sk,
+static unsigned int tcp_synack_options(struct sock *sk,
 				   struct request_sock *req,
-				   unsigned mss, struct sk_buff *skb,
+				   unsigned int mss, struct sk_buff *skb,
 				   struct tcp_out_options *opts,
 				   struct tcp_md5sig_key **md5,
 				   struct tcp_extend_values *xvp)
 {
 	struct inet_request_sock *ireq = inet_rsk(req);
-	unsigned remaining = MAX_TCP_OPTION_SPACE;
+	unsigned int remaining = MAX_TCP_OPTION_SPACE;
 	u8 cookie_plus = (xvp != NULL && !xvp->cookie_out_never) ?
 			 xvp->cookie_plus :
 			 0;
@@ -742,13 +743,13 @@ static unsigned tcp_synack_options(struct sock *sk,
 /* Compute TCP options for ESTABLISHED sockets. This is not the
  * final wire format yet.
  */
-static unsigned tcp_established_options(struct sock *sk, struct sk_buff *skb,
+static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb,
 					struct tcp_out_options *opts,
 					struct tcp_md5sig_key **md5)
 {
 	struct tcp_skb_cb *tcb = skb ? TCP_SKB_CB(skb) : NULL;
 	struct tcp_sock *tp = tcp_sk(sk);
-	unsigned size = 0;
+	unsigned int size = 0;
 	unsigned int eff_sacks;
 
 #ifdef CONFIG_TCP_MD5SIG
@@ -770,9 +771,9 @@ static unsigned tcp_established_options(struct sock *sk, struct sk_buff *skb,
 
 	eff_sacks = tp->rx_opt.num_sacks + tp->rx_opt.dsack;
 	if (unlikely(eff_sacks)) {
-		const unsigned remaining = MAX_TCP_OPTION_SPACE - size;
+		const unsigned int remaining = MAX_TCP_OPTION_SPACE - size;
 		opts->num_sack_blocks =
-			min_t(unsigned, eff_sacks,
+			min_t(unsigned int, eff_sacks,
 			      (remaining - TCPOLEN_SACK_BASE_ALIGNED) /
 			      TCPOLEN_SACK_PERBLOCK);
 		size += TCPOLEN_SACK_BASE_ALIGNED +
@@ -801,7 +802,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 	struct tcp_sock *tp;
 	struct tcp_skb_cb *tcb;
 	struct tcp_out_options opts;
-	unsigned tcp_options_size, tcp_header_size;
+	unsigned int tcp_options_size, tcp_header_size;
 	struct tcp_md5sig_key *md5;
 	struct tcphdr *th;
 	int err;
@@ -1096,6 +1097,7 @@ static void __pskb_trim_head(struct sk_buff *skb, int len)
 	eat = min_t(int, len, skb_headlen(skb));
 	if (eat) {
 		__skb_pull(skb, eat);
+		skb->avail_size -= eat;
 		len -= eat;
 		if (!len)
 			return;
@@ -1149,7 +1151,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
 }
 
 /* Calculate MSS. Not accounting for SACKs here.  */
-int tcp_mtu_to_mss(const struct sock *sk, int pmtu)
+int tcp_mtu_to_mss(struct sock *sk, int pmtu)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -1160,6 +1162,14 @@ int tcp_mtu_to_mss(const struct sock *sk, int pmtu)
 	 */
 	mss_now = pmtu - icsk->icsk_af_ops->net_header_len - sizeof(struct tcphdr);
 
+	/* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */
+	if (icsk->icsk_af_ops->net_frag_header_len) {
+		const struct dst_entry *dst = __sk_dst_get(sk);
+
+		if (dst && dst_allfrag(dst))
+			mss_now -= icsk->icsk_af_ops->net_frag_header_len;
+	}
+
 	/* Clamp it (mss_clamp does not include tcp options) */
 	if (mss_now > tp->rx_opt.mss_clamp)
 		mss_now = tp->rx_opt.mss_clamp;
@@ -1178,7 +1188,7 @@ int tcp_mtu_to_mss(const struct sock *sk, int pmtu)
 }
 
 /* Inverse of above */
-int tcp_mss_to_mtu(const struct sock *sk, int mss)
+int tcp_mss_to_mtu(struct sock *sk, int mss)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -1189,6 +1199,13 @@ int tcp_mss_to_mtu(const struct sock *sk, int mss)
 	      icsk->icsk_ext_hdr_len +
 	      icsk->icsk_af_ops->net_header_len;
 
+	/* IPv6 adds a frag_hdr in case RTAX_FEATURE_ALLFRAG is set */
+	if (icsk->icsk_af_ops->net_frag_header_len) {
+		const struct dst_entry *dst = __sk_dst_get(sk);
+
+		if (dst && dst_allfrag(dst))
+			mtu += icsk->icsk_af_ops->net_frag_header_len;
+	}
 	return mtu;
 }
 
@@ -1258,7 +1275,7 @@ unsigned int tcp_current_mss(struct sock *sk)
 	const struct tcp_sock *tp = tcp_sk(sk);
 	const struct dst_entry *dst = __sk_dst_get(sk);
 	u32 mss_now;
-	unsigned header_len;
+	unsigned int header_len;
 	struct tcp_out_options opts;
 	struct tcp_md5sig_key *md5;
 
@@ -1374,33 +1391,33 @@ static int tcp_init_tso_segs(const struct sock *sk, struct sk_buff *skb,
 }
 
 /* Minshall's variant of the Nagle send check. */
-static inline int tcp_minshall_check(const struct tcp_sock *tp)
+static inline bool tcp_minshall_check(const struct tcp_sock *tp)
 {
 	return after(tp->snd_sml, tp->snd_una) &&
 		!after(tp->snd_sml, tp->snd_nxt);
 }
 
-/* Return 0, if packet can be sent now without violation Nagle's rules:
+/* Return false, if packet can be sent now without violation Nagle's rules:
  * 1. It is full sized.
  * 2. Or it contains FIN. (already checked by caller)
  * 3. Or TCP_CORK is not set, and TCP_NODELAY is set.
  * 4. Or TCP_CORK is not set, and all sent packets are ACKed.
  *    With Minshall's modification: all sent small packets are ACKed.
  */
-static inline int tcp_nagle_check(const struct tcp_sock *tp,
+static inline bool tcp_nagle_check(const struct tcp_sock *tp,
 				  const struct sk_buff *skb,
-				  unsigned mss_now, int nonagle)
+				  unsigned int mss_now, int nonagle)
 {
 	return skb->len < mss_now &&
 		((nonagle & TCP_NAGLE_CORK) ||
 		 (!nonagle && tp->packets_out && tcp_minshall_check(tp)));
 }
 
-/* Return non-zero if the Nagle test allows this packet to be
+/* Return true if the Nagle test allows this packet to be
  * sent now.
  */
-static inline int tcp_nagle_test(const struct tcp_sock *tp, const struct sk_buff *skb,
-				 unsigned int cur_mss, int nonagle)
+static inline bool tcp_nagle_test(const struct tcp_sock *tp, const struct sk_buff *skb,
+				  unsigned int cur_mss, int nonagle)
 {
 	/* Nagle rule does not apply to frames, which sit in the middle of the
 	 * write_queue (they have no chances to get new data).
@@ -1409,24 +1426,25 @@ static inline int tcp_nagle_test(const struct tcp_sock *tp, const struct sk_buff
 	 * argument based upon the location of SKB in the send queue.
 	 */
 	if (nonagle & TCP_NAGLE_PUSH)
-		return 1;
+		return true;
 
 	/* Don't use the nagle rule for urgent data (or for the final FIN).
 	 * Nagle can be ignored during F-RTO too (see RFC4138).
 	 */
 	if (tcp_urg_mode(tp) || (tp->frto_counter == 2) ||
 	    (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN))
-		return 1;
+		return true;
 
 	if (!tcp_nagle_check(tp, skb, cur_mss, nonagle))
-		return 1;
+		return true;
 
-	return 0;
+	return false;
 }
 
 /* Does at least the first segment of SKB fit into the send window? */
-static inline int tcp_snd_wnd_test(const struct tcp_sock *tp, const struct sk_buff *skb,
-				   unsigned int cur_mss)
+static bool tcp_snd_wnd_test(const struct tcp_sock *tp,
+			     const struct sk_buff *skb,
+			     unsigned int cur_mss)
 {
 	u32 end_seq = TCP_SKB_CB(skb)->end_seq;
 
@@ -1459,7 +1477,7 @@ static unsigned int tcp_snd_test(const struct sock *sk, struct sk_buff *skb,
 }
 
 /* Test if sending is allowed right now. */
-int tcp_may_send_now(struct sock *sk)
+bool tcp_may_send_now(struct sock *sk)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb = tcp_send_head(sk);
@@ -1529,7 +1547,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
  *
  * This algorithm is from John Heffner.
  */
-static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
+static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -1589,11 +1607,11 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
 	/* Ok, it looks like it is advisable to defer.  */
 	tp->tso_deferred = 1 | (jiffies << 1);
 
-	return 1;
+	return true;
 
 send_now:
 	tp->tso_deferred = 0;
-	return 0;
+	return false;
 }
 
 /* Create a new MTU probe if we are ready.
@@ -1735,11 +1753,11 @@ static int tcp_mtu_probe(struct sock *sk)
  * snd_up-64k-mss .. snd_up cannot be large. However, taking into
  * account rare use of URG, this is not a big flaw.
  *
- * Returns 1, if no segments are in flight and we have queued segments, but
- * cannot send anything now because of SWS or another problem.
+ * Returns true, if no segments are in flight and we have queued segments,
+ * but cannot send anything now because of SWS or another problem.
  */
-static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
-			  int push_one, gfp_t gfp)
+static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
+			   int push_one, gfp_t gfp)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb;
@@ -1753,7 +1771,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 		/* Do MTU probing. */
 		result = tcp_mtu_probe(sk);
 		if (!result) {
-			return 0;
+			return false;
 		} else if (result > 0) {
 			sent_pkts = 1;
 		}
@@ -1812,7 +1830,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 
 	if (likely(sent_pkts)) {
 		tcp_cwnd_validate(sk);
-		return 0;
+		return false;
 	}
 	return !tp->packets_out && tcp_send_head(sk);
 }
@@ -2011,22 +2029,22 @@ static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb)
 }
 
 /* Check if coalescing SKBs is legal. */
-static int tcp_can_collapse(const struct sock *sk, const struct sk_buff *skb)
+static bool tcp_can_collapse(const struct sock *sk, const struct sk_buff *skb)
 {
 	if (tcp_skb_pcount(skb) > 1)
-		return 0;
+		return false;
 	/* TODO: SACK collapsing could be used to remove this condition */
 	if (skb_shinfo(skb)->nr_frags != 0)
-		return 0;
+		return false;
 	if (skb_cloned(skb))
-		return 0;
+		return false;
 	if (skb == tcp_send_head(sk))
-		return 0;
+		return false;
 	/* Some heurestics for collapsing over SACK'd could be invented */
 	if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
-		return 0;
+		return false;
 
-	return 1;
+	return true;
 }
 
 /* Collapse packets in the retransmit queue to make to create
@@ -2037,7 +2055,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb = to, *tmp;
-	int first = 1;
+	bool first = true;
 
 	if (!sysctl_tcp_retrans_collapse)
 		return;
@@ -2051,7 +2069,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
 		space -= skb->len;
 
 		if (first) {
-			first = 0;
+			first = false;
 			continue;
 		}
 
@@ -2060,7 +2078,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
 		/* Punt if not enough space exists in the first SKB for
 		 * the data in the second
 		 */
-		if (skb->len > skb_tailroom(to))
+		if (skb->len > skb_availroom(to))
 			break;
 
 		if (after(TCP_SKB_CB(skb)->end_seq, tcp_wnd_end(tp)))
@@ -2166,8 +2184,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 
 #if FASTRETRANS_DEBUG > 0
 		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) {
-			if (net_ratelimit())
-				printk(KERN_DEBUG "retrans_out leaked.\n");
+			net_dbg_ratelimited("retrans_out leaked\n");
 		}
 #endif
 		if (!tp->retrans_out)
@@ -2192,18 +2209,18 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 /* Check if we forward retransmits are possible in the current
  * window/congestion state.
  */
-static int tcp_can_forward_retransmit(struct sock *sk)
+static bool tcp_can_forward_retransmit(struct sock *sk)
 {
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	const struct tcp_sock *tp = tcp_sk(sk);
 
 	/* Forward retransmissions are possible only during Recovery. */
 	if (icsk->icsk_ca_state != TCP_CA_Recovery)
-		return 0;
+		return false;
 
 	/* No forward retransmissions in Reno are possible. */
 	if (tcp_is_reno(tp))
-		return 0;
+		return false;
 
 	/* Yeah, we have to make difficult choice between forward transmission
 	 * and retransmission... Both ways have their merits...
@@ -2214,9 +2231,9 @@ static int tcp_can_forward_retransmit(struct sock *sk)
 	 */
 
 	if (tcp_may_send_now(sk))
-		return 0;
+		return false;
 
-	return 1;
+	return true;
 }
 
 /* This gets called after a retransmit timeout, and the initially
@@ -2306,8 +2323,10 @@ begin_fwd:
 		if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))
 			continue;
 
-		if (tcp_retransmit_skb(sk, skb))
+		if (tcp_retransmit_skb(sk, skb)) {
+			NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL);
 			return;
+		}
 		NET_INC_STATS_BH(sock_net(sk), mib_idx);
 
 		if (inet_csk(sk)->icsk_ca_state == TCP_CA_Recovery)
@@ -2399,7 +2418,7 @@ int tcp_send_synack(struct sock *sk)
 
 	skb = tcp_write_queue_head(sk);
 	if (skb == NULL || !(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
-		printk(KERN_DEBUG "tcp_send_synack: wrong queue state\n");
+		pr_debug("%s: wrong queue state\n", __func__);
 		return -EFAULT;
 	}
 	if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK)) {
@@ -2559,7 +2578,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 EXPORT_SYMBOL(tcp_make_synack);
 
 /* Do all connect socket setups that can be done AF independent. */
-static void tcp_connect_init(struct sock *sk)
+void tcp_connect_init(struct sock *sk)
 {
 	const struct dst_entry *dst = __sk_dst_get(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -2614,9 +2633,12 @@ static void tcp_connect_init(struct sock *sk)
 	tp->snd_una = tp->write_seq;
 	tp->snd_sml = tp->write_seq;
 	tp->snd_up = tp->write_seq;
-	tp->rcv_nxt = 0;
-	tp->rcv_wup = 0;
-	tp->copied_seq = 0;
+	tp->snd_nxt = tp->write_seq;
+
+	if (likely(!tp->repair))
+		tp->rcv_nxt = 0;
+	tp->rcv_wup = tp->rcv_nxt;
+	tp->copied_seq = tp->rcv_nxt;
 
 	inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
 	inet_csk(sk)->icsk_retransmits = 0;
@@ -2639,7 +2661,6 @@ int tcp_connect(struct sock *sk)
 	/* Reserve space for headers. */
 	skb_reserve(buff, MAX_TCP_HEADER);
 
-	tp->snd_nxt = tp->write_seq;
 	tcp_init_nondata_skb(buff, tp->write_seq++, TCPHDR_SYN);
 	TCP_ECN_send_syn(sk, buff);
 
@@ -2788,6 +2809,15 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
 	return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
 }
 
+void tcp_send_window_probe(struct sock *sk)
+{
+	if (sk->sk_state == TCP_ESTABLISHED) {
+		tcp_sk(sk)->snd_wl1 = tcp_sk(sk)->rcv_nxt - 1;
+		tcp_sk(sk)->snd_nxt = tcp_sk(sk)->write_seq;
+		tcp_xmit_probe_skb(sk, 0);
+	}
+}
+
 /* Initiate keepalive or window probe from timer. */
 int tcp_write_wakeup(struct sock *sk)
 {