Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says: ==================== The following patchset contains Netfilter fixes. They are targeted to the TCP option targets, that have receive some scrinity in the last week. The changes are: * Fix TCPOPTSTRIP, it stopped working in the forward chain as tcp_hdr uses skb->transport_header, and we cannot use that in the forwarding case, from myself. * Fix default IPv6 MSS in TCPMSS in case of absence of TCP MSS options, from Phil Oester. * Fix missing fragmentation handling again in TCPMSS, from Phil Oester. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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Коммит
e00c7f1fad
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@ -45,17 +45,22 @@ optlen(const u_int8_t *opt, unsigned int offset)
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static int
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static int
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tcpmss_mangle_packet(struct sk_buff *skb,
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tcpmss_mangle_packet(struct sk_buff *skb,
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const struct xt_tcpmss_info *info,
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const struct xt_action_param *par,
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unsigned int in_mtu,
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unsigned int in_mtu,
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unsigned int tcphoff,
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unsigned int tcphoff,
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unsigned int minlen)
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unsigned int minlen)
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{
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{
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const struct xt_tcpmss_info *info = par->targinfo;
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struct tcphdr *tcph;
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struct tcphdr *tcph;
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unsigned int tcplen, i;
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unsigned int tcplen, i;
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__be16 oldval;
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__be16 oldval;
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u16 newmss;
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u16 newmss;
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u8 *opt;
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u8 *opt;
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/* This is a fragment, no TCP header is available */
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if (par->fragoff != 0)
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return XT_CONTINUE;
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if (!skb_make_writable(skb, skb->len))
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if (!skb_make_writable(skb, skb->len))
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return -1;
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return -1;
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@ -125,11 +130,17 @@ tcpmss_mangle_packet(struct sk_buff *skb,
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skb_put(skb, TCPOLEN_MSS);
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skb_put(skb, TCPOLEN_MSS);
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/* RFC 879 states that the default MSS is 536 without specific
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/*
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* knowledge that the destination host is prepared to accept larger.
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* IPv4: RFC 1122 states "If an MSS option is not received at
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* Since no MSS was provided, we MUST NOT set a value > 536.
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* connection setup, TCP MUST assume a default send MSS of 536".
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* IPv6: RFC 2460 states IPv6 has a minimum MTU of 1280 and a minimum
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* length IPv6 header of 60, ergo the default MSS value is 1220
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* Since no MSS was provided, we must use the default values
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*/
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*/
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newmss = min(newmss, (u16)536);
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if (par->family == NFPROTO_IPV4)
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newmss = min(newmss, (u16)536);
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else
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newmss = min(newmss, (u16)1220);
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opt = (u_int8_t *)tcph + sizeof(struct tcphdr);
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opt = (u_int8_t *)tcph + sizeof(struct tcphdr);
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memmove(opt + TCPOLEN_MSS, opt, tcplen - sizeof(struct tcphdr));
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memmove(opt + TCPOLEN_MSS, opt, tcplen - sizeof(struct tcphdr));
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@ -188,7 +199,7 @@ tcpmss_tg4(struct sk_buff *skb, const struct xt_action_param *par)
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__be16 newlen;
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__be16 newlen;
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int ret;
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int ret;
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ret = tcpmss_mangle_packet(skb, par->targinfo,
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ret = tcpmss_mangle_packet(skb, par,
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tcpmss_reverse_mtu(skb, PF_INET),
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tcpmss_reverse_mtu(skb, PF_INET),
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iph->ihl * 4,
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iph->ihl * 4,
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sizeof(*iph) + sizeof(struct tcphdr));
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sizeof(*iph) + sizeof(struct tcphdr));
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@ -217,7 +228,7 @@ tcpmss_tg6(struct sk_buff *skb, const struct xt_action_param *par)
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tcphoff = ipv6_skip_exthdr(skb, sizeof(*ipv6h), &nexthdr, &frag_off);
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tcphoff = ipv6_skip_exthdr(skb, sizeof(*ipv6h), &nexthdr, &frag_off);
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if (tcphoff < 0)
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if (tcphoff < 0)
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return NF_DROP;
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return NF_DROP;
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ret = tcpmss_mangle_packet(skb, par->targinfo,
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ret = tcpmss_mangle_packet(skb, par,
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tcpmss_reverse_mtu(skb, PF_INET6),
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tcpmss_reverse_mtu(skb, PF_INET6),
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tcphoff,
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tcphoff,
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sizeof(*ipv6h) + sizeof(struct tcphdr));
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sizeof(*ipv6h) + sizeof(struct tcphdr));
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@ -48,11 +48,13 @@ tcpoptstrip_mangle_packet(struct sk_buff *skb,
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return NF_DROP;
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return NF_DROP;
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len = skb->len - tcphoff;
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len = skb->len - tcphoff;
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if (len < (int)sizeof(struct tcphdr) ||
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if (len < (int)sizeof(struct tcphdr))
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tcp_hdr(skb)->doff * 4 > len)
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return NF_DROP;
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return NF_DROP;
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tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff);
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tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff);
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if (tcph->doff * 4 > len)
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return NF_DROP;
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opt = (u_int8_t *)tcph;
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opt = (u_int8_t *)tcph;
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/*
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/*
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