diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/xt_tcpmss.c | 48 |
1 files changed, 18 insertions, 30 deletions
diff --git a/net/netfilter/xt_tcpmss.c b/net/netfilter/xt_tcpmss.c index 7baa9ebc46c..a3682fe2f19 100644 --- a/net/netfilter/xt_tcpmss.c +++ b/net/netfilter/xt_tcpmss.c @@ -18,21 +18,22 @@ #include <linux/netfilter_ipv4/ip_tables.h> #include <linux/netfilter_ipv6/ip6_tables.h> -#define TH_SYN 0x02 - MODULE_LICENSE("GPL"); MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>"); MODULE_DESCRIPTION("iptables TCP MSS match module"); MODULE_ALIAS("ipt_tcpmss"); -/* Returns 1 if the mss option is set and matched by the range, 0 otherwise */ -static inline int -mssoption_match(u_int16_t min, u_int16_t max, - const struct sk_buff *skb, - unsigned int protoff, - int invert, - int *hotdrop) +static int +match(const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct xt_match *match, + const void *matchinfo, + int offset, + unsigned int protoff, + int *hotdrop) { + const struct xt_tcpmss_match_info *info = matchinfo; struct tcphdr _tcph, *th; /* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */ u8 _opt[15 * 4 - sizeof(_tcph)], *op; @@ -64,35 +65,22 @@ mssoption_match(u_int16_t min, u_int16_t max, mssval = (op[i+2] << 8) | op[i+3]; - return (mssval >= min && mssval <= max) ^ invert; + return (mssval >= info->mss_min && + mssval <= info->mss_max) ^ info->invert; } - if (op[i] < 2) i++; - else i += op[i+1]?:1; + if (op[i] < 2) + i++; + else + i += op[i+1] ? : 1; } out: - return invert; + return info->invert; - dropit: +dropit: *hotdrop = 1; return 0; } -static int -match(const struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - const struct xt_match *match, - const void *matchinfo, - int offset, - unsigned int protoff, - int *hotdrop) -{ - const struct xt_tcpmss_match_info *info = matchinfo; - - return mssoption_match(info->mss_min, info->mss_max, skb, protoff, - info->invert, hotdrop); -} - static struct xt_match xt_tcpmss_match[] = { { .name = "tcpmss", |