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@@ -18,21 +18,22 @@
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/netfilter_ipv6/ip6_tables.h>
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#include <linux/netfilter_ipv6/ip6_tables.h>
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-#define TH_SYN 0x02
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-
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MODULE_LICENSE("GPL");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
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MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
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MODULE_DESCRIPTION("iptables TCP MSS match module");
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MODULE_DESCRIPTION("iptables TCP MSS match module");
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MODULE_ALIAS("ipt_tcpmss");
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MODULE_ALIAS("ipt_tcpmss");
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-/* Returns 1 if the mss option is set and matched by the range, 0 otherwise */
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-static inline int
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-mssoption_match(u_int16_t min, u_int16_t max,
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- const struct sk_buff *skb,
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- unsigned int protoff,
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- int invert,
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- int *hotdrop)
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+static int
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+match(const struct sk_buff *skb,
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+ const struct net_device *in,
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+ const struct net_device *out,
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+ const struct xt_match *match,
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+ const void *matchinfo,
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+ int offset,
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+ unsigned int protoff,
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+ int *hotdrop)
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{
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{
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+ const struct xt_tcpmss_match_info *info = matchinfo;
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struct tcphdr _tcph, *th;
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struct tcphdr _tcph, *th;
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/* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
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/* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
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u8 _opt[15 * 4 - sizeof(_tcph)], *op;
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u8 _opt[15 * 4 - sizeof(_tcph)], *op;
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@@ -64,35 +65,22 @@ mssoption_match(u_int16_t min, u_int16_t max,
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mssval = (op[i+2] << 8) | op[i+3];
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mssval = (op[i+2] << 8) | op[i+3];
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- return (mssval >= min && mssval <= max) ^ invert;
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+ return (mssval >= info->mss_min &&
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+ mssval <= info->mss_max) ^ info->invert;
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}
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}
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- if (op[i] < 2) i++;
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- else i += op[i+1]?:1;
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+ if (op[i] < 2)
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+ i++;
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+ else
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+ i += op[i+1] ? : 1;
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}
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}
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out:
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out:
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- return invert;
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+ return info->invert;
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- dropit:
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+dropit:
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*hotdrop = 1;
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*hotdrop = 1;
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return 0;
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return 0;
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}
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}
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-static int
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-match(const struct sk_buff *skb,
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- const struct net_device *in,
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- const struct net_device *out,
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- const struct xt_match *match,
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- const void *matchinfo,
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- int offset,
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- unsigned int protoff,
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- int *hotdrop)
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-{
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- const struct xt_tcpmss_match_info *info = matchinfo;
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-
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- return mssoption_match(info->mss_min, info->mss_max, skb, protoff,
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- info->invert, hotdrop);
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-}
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-
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static struct xt_match xt_tcpmss_match[] = {
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static struct xt_match xt_tcpmss_match[] = {
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{
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{
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.name = "tcpmss",
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.name = "tcpmss",
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