264 lines
9.0 KiB
Diff
264 lines
9.0 KiB
Diff
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
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index 0335285f3918..49935d5bb5c6 100644
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--- a/Documentation/networking/ip-sysctl.txt
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+++ b/Documentation/networking/ip-sysctl.txt
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@@ -230,6 +230,14 @@ tcp_base_mss - INTEGER
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Path MTU discovery (MTU probing). If MTU probing is enabled,
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this is the initial MSS used by the connection.
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+tcp_min_snd_mss - INTEGER
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+ TCP SYN and SYNACK messages usually advertise an ADVMSS option,
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+ as described in RFC 1122 and RFC 6691.
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+ If this ADVMSS option is smaller than tcp_min_snd_mss,
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+ it is silently capped to tcp_min_snd_mss.
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+
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+ Default : 48 (at least 8 bytes of payload per segment)
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+
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tcp_congestion_control - STRING
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Set the congestion control algorithm to be used for new
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connections. The algorithm "reno" is always available, but
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diff --git a/Makefile b/Makefile
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index 584af2e57735..f34cb9225255 100644
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--- a/Makefile
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+++ b/Makefile
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@@ -1,6 +1,6 @@
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VERSION = 4
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PATCHLEVEL = 9
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-SUBLEVEL = 181
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+SUBLEVEL = 182
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EXTRAVERSION =
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NAME = Roaring Lionus
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diff --git a/include/linux/tcp.h b/include/linux/tcp.h
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index d0c3615f9050..7f517458c64f 100644
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--- a/include/linux/tcp.h
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+++ b/include/linux/tcp.h
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@@ -433,4 +433,7 @@ static inline void tcp_saved_syn_free(struct tcp_sock *tp)
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tp->saved_syn = NULL;
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}
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+int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, int pcount,
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+ int shiftlen);
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+
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#endif /* _LINUX_TCP_H */
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diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
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index 7adf4386ac8f..bf619a67ec03 100644
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--- a/include/net/netns/ipv4.h
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+++ b/include/net/netns/ipv4.h
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@@ -94,6 +94,7 @@ struct netns_ipv4 {
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#endif
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int sysctl_tcp_mtu_probing;
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int sysctl_tcp_base_mss;
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+ int sysctl_tcp_min_snd_mss;
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int sysctl_tcp_probe_threshold;
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u32 sysctl_tcp_probe_interval;
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diff --git a/include/net/tcp.h b/include/net/tcp.h
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index fed2a78fb8cb..d7047de952f0 100644
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--- a/include/net/tcp.h
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+++ b/include/net/tcp.h
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@@ -53,6 +53,8 @@ void tcp_time_wait(struct sock *sk, int state, int timeo);
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#define MAX_TCP_HEADER (128 + MAX_HEADER)
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#define MAX_TCP_OPTION_SPACE 40
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+#define TCP_MIN_SND_MSS 48
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+#define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE)
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/*
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* Never offer a window over 32767 without using window scaling. Some
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diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
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index 3442a26d36d9..56e3460d1f9f 100644
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--- a/include/uapi/linux/snmp.h
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+++ b/include/uapi/linux/snmp.h
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@@ -282,6 +282,7 @@ enum
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LINUX_MIB_TCPKEEPALIVE, /* TCPKeepAlive */
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LINUX_MIB_TCPMTUPFAIL, /* TCPMTUPFail */
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LINUX_MIB_TCPMTUPSUCCESS, /* TCPMTUPSuccess */
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+ LINUX_MIB_TCPWQUEUETOOBIG, /* TCPWqueueTooBig */
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__LINUX_MIB_MAX
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};
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diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
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index ec48d8eafc7e..8b221398534b 100644
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--- a/net/ipv4/proc.c
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+++ b/net/ipv4/proc.c
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@@ -306,6 +306,7 @@ static const struct snmp_mib snmp4_net_list[] = {
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SNMP_MIB_ITEM("TCPKeepAlive", LINUX_MIB_TCPKEEPALIVE),
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SNMP_MIB_ITEM("TCPMTUPFail", LINUX_MIB_TCPMTUPFAIL),
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SNMP_MIB_ITEM("TCPMTUPSuccess", LINUX_MIB_TCPMTUPSUCCESS),
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+ SNMP_MIB_ITEM("TCPWqueueTooBig", LINUX_MIB_TCPWQUEUETOOBIG),
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SNMP_MIB_SENTINEL
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};
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diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
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index 85713adf2770..e202babb14d6 100644
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--- a/net/ipv4/sysctl_net_ipv4.c
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+++ b/net/ipv4/sysctl_net_ipv4.c
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@@ -35,6 +35,8 @@ static int ip_local_port_range_min[] = { 1, 1 };
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static int ip_local_port_range_max[] = { 65535, 65535 };
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static int tcp_adv_win_scale_min = -31;
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static int tcp_adv_win_scale_max = 31;
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+static int tcp_min_snd_mss_min = TCP_MIN_SND_MSS;
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+static int tcp_min_snd_mss_max = 65535;
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static int ip_ttl_min = 1;
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static int ip_ttl_max = 255;
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static int tcp_syn_retries_min = 1;
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@@ -838,6 +840,15 @@ static struct ctl_table ipv4_net_table[] = {
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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+ {
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+ .procname = "tcp_min_snd_mss",
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+ .data = &init_net.ipv4.sysctl_tcp_min_snd_mss,
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+ .maxlen = sizeof(int),
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+ .mode = 0644,
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+ .proc_handler = proc_dointvec_minmax,
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+ .extra1 = &tcp_min_snd_mss_min,
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+ .extra2 = &tcp_min_snd_mss_max,
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+ },
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{
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.procname = "tcp_probe_threshold",
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.data = &init_net.ipv4.sysctl_tcp_probe_threshold,
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diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
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index 2ededb32b754..ee2822a411f9 100644
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--- a/net/ipv4/tcp.c
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+++ b/net/ipv4/tcp.c
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@@ -3307,6 +3307,7 @@ void __init tcp_init(void)
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unsigned long limit;
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unsigned int i;
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+ BUILD_BUG_ON(TCP_MIN_SND_MSS <= MAX_TCP_OPTION_SPACE);
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BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
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FIELD_SIZEOF(struct sk_buff, cb));
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diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
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index e238539c3497..e2e58bc42ba4 100644
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--- a/net/ipv4/tcp_input.c
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+++ b/net/ipv4/tcp_input.c
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@@ -1320,7 +1320,7 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *skb,
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TCP_SKB_CB(skb)->seq += shifted;
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tcp_skb_pcount_add(prev, pcount);
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- BUG_ON(tcp_skb_pcount(skb) < pcount);
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+ WARN_ON_ONCE(tcp_skb_pcount(skb) < pcount);
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tcp_skb_pcount_add(skb, -pcount);
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/* When we're adding to gso_segs == 1, gso_size will be zero,
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@@ -1387,6 +1387,21 @@ static int skb_can_shift(const struct sk_buff *skb)
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return !skb_headlen(skb) && skb_is_nonlinear(skb);
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}
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+int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from,
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+ int pcount, int shiftlen)
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+{
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+ /* TCP min gso_size is 8 bytes (TCP_MIN_GSO_SIZE)
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+ * Since TCP_SKB_CB(skb)->tcp_gso_segs is 16 bits, we need
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+ * to make sure not storing more than 65535 * 8 bytes per skb,
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+ * even if current MSS is bigger.
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+ */
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+ if (unlikely(to->len + shiftlen >= 65535 * TCP_MIN_GSO_SIZE))
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+ return 0;
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+ if (unlikely(tcp_skb_pcount(to) + pcount > 65535))
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+ return 0;
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+ return skb_shift(to, from, shiftlen);
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+}
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+
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/* Try collapsing SACK blocks spanning across multiple skbs to a single
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* skb.
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*/
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@@ -1398,6 +1413,7 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb,
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struct tcp_sock *tp = tcp_sk(sk);
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struct sk_buff *prev;
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int mss;
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+ int next_pcount;
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int pcount = 0;
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int len;
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int in_sack;
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@@ -1495,7 +1511,7 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb,
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if (!after(TCP_SKB_CB(skb)->seq + len, tp->snd_una))
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goto fallback;
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- if (!skb_shift(prev, skb, len))
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+ if (!tcp_skb_shift(prev, skb, pcount, len))
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goto fallback;
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if (!tcp_shifted_skb(sk, skb, state, pcount, len, mss, dup_sack))
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goto out;
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@@ -1514,11 +1530,11 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb,
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goto out;
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len = skb->len;
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- if (skb_shift(prev, skb, len)) {
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- pcount += tcp_skb_pcount(skb);
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- tcp_shifted_skb(sk, skb, state, tcp_skb_pcount(skb), len, mss, 0);
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+ next_pcount = tcp_skb_pcount(skb);
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+ if (tcp_skb_shift(prev, skb, next_pcount, len)) {
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+ pcount += next_pcount;
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+ tcp_shifted_skb(sk, skb, state, next_pcount, len, mss, 0);
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}
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-
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out:
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state->fack_count += pcount;
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return prev;
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@@ -2837,9 +2853,9 @@ static void tcp_fastretrans_alert(struct sock *sk, const int acked,
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bool do_lost = is_dupack || ((flag & FLAG_DATA_SACKED) &&
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(tcp_fackets_out(tp) > tp->reordering));
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- if (WARN_ON(!tp->packets_out && tp->sacked_out))
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+ if (!tp->packets_out && tp->sacked_out)
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tp->sacked_out = 0;
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- if (WARN_ON(!tp->sacked_out && tp->fackets_out))
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+ if (!tp->sacked_out && tp->fackets_out)
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tp->fackets_out = 0;
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/* Now state machine starts.
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diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
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index 82c1064ff4aa..848f2c1da8a5 100644
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--- a/net/ipv4/tcp_ipv4.c
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+++ b/net/ipv4/tcp_ipv4.c
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@@ -2456,6 +2456,7 @@ static int __net_init tcp_sk_init(struct net *net)
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net->ipv4.sysctl_tcp_ecn_fallback = 1;
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net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS;
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+ net->ipv4.sysctl_tcp_min_snd_mss = TCP_MIN_SND_MSS;
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net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD;
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net->ipv4.sysctl_tcp_probe_interval = TCP_PROBE_INTERVAL;
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diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
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index 6f35cdd5f2f0..d8c6b833f0ce 100644
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--- a/net/ipv4/tcp_output.c
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+++ b/net/ipv4/tcp_output.c
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@@ -1185,6 +1185,11 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
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if (nsize < 0)
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nsize = 0;
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+ if (unlikely((sk->sk_wmem_queued >> 1) > sk->sk_sndbuf)) {
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+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPWQUEUETOOBIG);
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+ return -ENOMEM;
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+ }
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+
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if (skb_unclone(skb, gfp))
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return -ENOMEM;
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@@ -1355,8 +1360,7 @@ static inline int __tcp_mtu_to_mss(struct sock *sk, int pmtu)
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mss_now -= icsk->icsk_ext_hdr_len;
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/* Then reserve room for full set of TCP options and 8 bytes of data */
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- if (mss_now < 48)
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- mss_now = 48;
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+ mss_now = max(mss_now, sock_net(sk)->ipv4.sysctl_tcp_min_snd_mss);
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return mss_now;
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}
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diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
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index 69523389f067..d9e364c4863a 100644
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--- a/net/ipv4/tcp_timer.c
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+++ b/net/ipv4/tcp_timer.c
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@@ -140,6 +140,7 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk)
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mss = tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low) >> 1;
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mss = min(net->ipv4.sysctl_tcp_base_mss, mss);
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mss = max(mss, 68 - tp->tcp_header_len);
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+ mss = max(mss, net->ipv4.sysctl_tcp_min_snd_mss);
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icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss);
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tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
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}
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