From 269aa759b474570fa642452742741525cfc226a9 Mon Sep 17 00:00:00 2001 From: Neal Cardwell Date: Mon, 16 Sep 2013 21:44:20 -0400 Subject: tcp: fix RTO calculated from cached RTT Commit 1b7fdd2ab5852 ("tcp: do not use cached RTT for RTT estimation") did not correctly account for the fact that crtt is the RTT shifted left 3 bits. Fix the calculation to consistently reflect this fact. Signed-off-by: Neal Cardwell Cc: Eric Dumazet Cc: Yuchung Cheng Acked-by: Eric Dumazet Acked-By: Yuchung Cheng Signed-off-by: David S. Miller --- net/ipv4/tcp_metrics.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/ipv4') diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c index 4a22f3e..52f3c6b 100644 --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -502,7 +502,9 @@ reset: * ACKs, wait for troubles. */ if (crtt > tp->srtt) { - inet_csk(sk)->icsk_rto = crtt + max(crtt >> 2, tcp_rto_min(sk)); + /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */ + crtt >>= 3; + inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk)); } else if (tp->srtt == 0) { /* RFC6298: 5.7 We've failed to get a valid RTT sample from * 3WHS. This is most likely due to retransmission, -- cgit v1.1 From 749154aa56b57652a282cbde57a57abc278d1205 Mon Sep 17 00:00:00 2001 From: Ansis Atteka Date: Wed, 18 Sep 2013 15:29:52 -0700 Subject: ip: use ip_hdr() in __ip_make_skb() to retrieve IP header skb->data already points to IP header, but for the sake of consistency we can also use ip_hdr() to retrieve it. Signed-off-by: Ansis Atteka Signed-off-by: David S. Miller --- net/ipv4/ip_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4') diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 9ee17e3..eae2e26 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1316,7 +1316,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk, else ttl = ip_select_ttl(inet, &rt->dst); - iph = (struct iphdr *)skb->data; + iph = ip_hdr(skb); iph->version = 4; iph->ihl = 5; iph->tos = inet->tos; -- cgit v1.1 From 703133de331a7a7df47f31fb9de51dc6f68a9de8 Mon Sep 17 00:00:00 2001 From: Ansis Atteka Date: Wed, 18 Sep 2013 15:29:53 -0700 Subject: ip: generate unique IP identificator if local fragmentation is allowed If local fragmentation is allowed, then ip_select_ident() and ip_select_ident_more() need to generate unique IDs to ensure correct defragmentation on the peer. For example, if IPsec (tunnel mode) has to encrypt large skbs that have local_df bit set, then all IP fragments that belonged to different ESP datagrams would have used the same identificator. If one of these IP fragments would get lost or reordered, then peer could possibly stitch together wrong IP fragments that did not belong to the same datagram. This would lead to a packet loss or data corruption. Signed-off-by: Ansis Atteka Signed-off-by: David S. Miller --- net/ipv4/igmp.c | 4 ++-- net/ipv4/inetpeer.c | 4 ++-- net/ipv4/ip_output.c | 6 +++--- net/ipv4/ipmr.c | 2 +- net/ipv4/raw.c | 2 +- net/ipv4/xfrm4_mode_tunnel.c | 2 +- 6 files changed, 10 insertions(+), 10 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index d6c0e64..dace87f 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -369,7 +369,7 @@ static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size) pip->saddr = fl4.saddr; pip->protocol = IPPROTO_IGMP; pip->tot_len = 0; /* filled in later */ - ip_select_ident(pip, &rt->dst, NULL); + ip_select_ident(skb, &rt->dst, NULL); ((u8 *)&pip[1])[0] = IPOPT_RA; ((u8 *)&pip[1])[1] = 4; ((u8 *)&pip[1])[2] = 0; @@ -714,7 +714,7 @@ static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc, iph->daddr = dst; iph->saddr = fl4.saddr; iph->protocol = IPPROTO_IGMP; - ip_select_ident(iph, &rt->dst, NULL); + ip_select_ident(skb, &rt->dst, NULL); ((u8 *)&iph[1])[0] = IPOPT_RA; ((u8 *)&iph[1])[1] = 4; ((u8 *)&iph[1])[2] = 0; diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c index 000e3d2..33d5537 100644 --- a/net/ipv4/inetpeer.c +++ b/net/ipv4/inetpeer.c @@ -32,8 +32,8 @@ * At the moment of writing this notes identifier of IP packets is generated * to be unpredictable using this code only for packets subjected * (actually or potentially) to defragmentation. I.e. DF packets less than - * PMTU in size uses a constant ID and do not use this code (see - * ip_select_ident() in include/net/ip.h). + * PMTU in size when local fragmentation is disabled use a constant ID and do + * not use this code (see ip_select_ident() in include/net/ip.h). * * Route cache entries hold references to our nodes. * New cache entries get references via lookup by destination IP address in diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index eae2e26..a04d872 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -148,7 +148,7 @@ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, iph->daddr = (opt && opt->opt.srr ? opt->opt.faddr : daddr); iph->saddr = saddr; iph->protocol = sk->sk_protocol; - ip_select_ident(iph, &rt->dst, sk); + ip_select_ident(skb, &rt->dst, sk); if (opt && opt->opt.optlen) { iph->ihl += opt->opt.optlen>>2; @@ -386,7 +386,7 @@ packet_routed: ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0); } - ip_select_ident_more(iph, &rt->dst, sk, + ip_select_ident_more(skb, &rt->dst, sk, (skb_shinfo(skb)->gso_segs ?: 1) - 1); skb->priority = sk->sk_priority; @@ -1324,7 +1324,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk, iph->ttl = ttl; iph->protocol = sk->sk_protocol; ip_copy_addrs(iph, fl4); - ip_select_ident(iph, &rt->dst, sk); + ip_select_ident(skb, &rt->dst, sk); if (opt) { iph->ihl += opt->optlen>>2; diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 9ae54b0..62212c7 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1658,7 +1658,7 @@ static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr) iph->protocol = IPPROTO_IPIP; iph->ihl = 5; iph->tot_len = htons(skb->len); - ip_select_ident(iph, skb_dst(skb), NULL); + ip_select_ident(skb, skb_dst(skb), NULL); ip_send_check(iph); memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index a86c7ae..bfec521 100644 --- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -387,7 +387,7 @@ static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4, iph->check = 0; iph->tot_len = htons(length); if (!iph->id) - ip_select_ident(iph, &rt->dst, NULL); + ip_select_ident(skb, &rt->dst, NULL); iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); } diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c index eb1dd4d..b5663c3 100644 --- a/net/ipv4/xfrm4_mode_tunnel.c +++ b/net/ipv4/xfrm4_mode_tunnel.c @@ -117,7 +117,7 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ? 0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF)); - ip_select_ident(top_iph, dst->child, NULL); + ip_select_ident(skb, dst->child, NULL); top_iph->ttl = ip4_dst_hoplimit(dst->child); -- cgit v1.1