`git log -p` just flies better than `git-format-patch` I guess. === commit 1ed78bbf75455dfe77a028f2da2f351cff4028f2 Author: Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx> Date: Sun Jan 20 13:13:33 2008 +0100 [NETFILTER]: xt_TCPMSS: Consider incoming device's MTU in clamp-to-pmtu The TCPMSS target in Xtables should consider the MTU of the input device on forwarded packets as part of the path MTU. Point in case: IN=ppp0, OUT=eth0. MSS set to 1460 in spite of MTU of ppp0 being 1392. Signed-off-by: Jaco Kroon <jaco@xxxxxxxxx> Signed-off-by: Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx> diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c index 60e3767..2c446b6 100644 --- a/net/netfilter/xt_TCPMSS.c +++ b/net/netfilter/xt_TCPMSS.c @@ -41,6 +41,7 @@ optlen(const u_int8_t *opt, unsigned int offset) static int tcpmss_mangle_packet(struct sk_buff *skb, const struct xt_tcpmss_info *info, + unsigned int in_mtu, unsigned int tcphoff, unsigned int minlen) { @@ -76,7 +77,13 @@ tcpmss_mangle_packet(struct sk_buff *skb, dst_mtu(skb->dst)); return -1; } - newmss = dst_mtu(skb->dst) - minlen; + if (in_mtu <= minlen) { + if (net_ratelimit()) + printk(KERN_ERR "xt_TCPMSS: unknown or " + "invalid path-MTU (%u)\n", in_mtu); + return -1; + } + newmss = min(dst_mtu(skb->dst), in_mtu) - minlen; } else newmss = info->mss; @@ -146,8 +153,8 @@ tcpmss_tg4(struct sk_buff *skb, const struct net_device *in, __be16 newlen; int ret; - ret = tcpmss_mangle_packet(skb, targinfo, iph->ihl * 4, - sizeof(*iph) + sizeof(struct tcphdr)); + ret = tcpmss_mangle_packet(skb, targinfo, (in == NULL) ? ~0U : in->mtu, + iph->ihl * 4, sizeof(*iph) + sizeof(struct tcphdr)); if (ret < 0) return NF_DROP; if (ret > 0) { @@ -174,8 +181,8 @@ tcpmss_tg6(struct sk_buff *skb, const struct net_device *in, tcphoff = ipv6_skip_exthdr(skb, sizeof(*ipv6h), &nexthdr); if (tcphoff < 0) return NF_DROP; - ret = tcpmss_mangle_packet(skb, targinfo, tcphoff, - sizeof(*ipv6h) + sizeof(struct tcphdr)); + ret = tcpmss_mangle_packet(skb, targinfo, (in == NULL) ? ~0U : in->mtu, + tcphoff, sizeof(*ipv6h) + sizeof(struct tcphdr)); if (ret < 0) return NF_DROP; if (ret > 0) { - To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html