diff options
Diffstat (limited to 'net/netfilter/xt_tcpudp.c')
| -rw-r--r-- | net/netfilter/xt_tcpudp.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/net/netfilter/xt_tcpudp.c b/net/netfilter/xt_tcpudp.c index 11ec2abf0c72..e8991130a3de 100644 --- a/net/netfilter/xt_tcpudp.c +++ b/net/netfilter/xt_tcpudp.c @@ -4,6 +4,7 @@ #include <linux/module.h> #include <net/ip.h> #include <linux/ipv6.h> +#include <linux/icmp.h> #include <net/ipv6.h> #include <net/tcp.h> #include <net/udp.h> @@ -20,6 +21,8 @@ MODULE_ALIAS("ipt_udp"); MODULE_ALIAS("ipt_tcp"); MODULE_ALIAS("ip6t_udp"); MODULE_ALIAS("ip6t_tcp"); +MODULE_ALIAS("ipt_icmp"); +MODULE_ALIAS("ip6t_icmp6"); /* Returns 1 if the port is matched by the range, 0 otherwise */ static inline bool @@ -161,6 +164,95 @@ static int udp_mt_check(const struct xt_mtchk_param *par) return (udpinfo->invflags & ~XT_UDP_INV_MASK) ? -EINVAL : 0; } +/* Returns 1 if the type and code is matched by the range, 0 otherwise */ +static bool type_code_in_range(u8 test_type, u8 min_code, u8 max_code, + u8 type, u8 code) +{ + return type == test_type && code >= min_code && code <= max_code; +} + +static bool icmp_type_code_match(u8 test_type, u8 min_code, u8 max_code, + u8 type, u8 code, bool invert) +{ + return (test_type == 0xFF || + type_code_in_range(test_type, min_code, max_code, type, code)) + ^ invert; +} + +static bool icmp6_type_code_match(u8 test_type, u8 min_code, u8 max_code, + u8 type, u8 code, bool invert) +{ + return type_code_in_range(test_type, min_code, max_code, type, code) ^ invert; +} + +static bool +icmp_match(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct icmphdr *ic; + struct icmphdr _icmph; + const struct ipt_icmp *icmpinfo = par->matchinfo; + + /* Must not be a fragment. */ + if (par->fragoff != 0) + return false; + + ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph); + if (!ic) { + /* We've been asked to examine this packet, and we + * can't. Hence, no choice but to drop. + */ + par->hotdrop = true; + return false; + } + + return icmp_type_code_match(icmpinfo->type, + icmpinfo->code[0], + icmpinfo->code[1], + ic->type, ic->code, + !!(icmpinfo->invflags & IPT_ICMP_INV)); +} + +static bool +icmp6_match(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct icmp6hdr *ic; + struct icmp6hdr _icmph; + const struct ip6t_icmp *icmpinfo = par->matchinfo; + + /* Must not be a fragment. */ + if (par->fragoff != 0) + return false; + + ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph); + if (!ic) { + /* We've been asked to examine this packet, and we + * can't. Hence, no choice but to drop. + */ + par->hotdrop = true; + return false; + } + + return icmp6_type_code_match(icmpinfo->type, + icmpinfo->code[0], + icmpinfo->code[1], + ic->icmp6_type, ic->icmp6_code, + !!(icmpinfo->invflags & IP6T_ICMP_INV)); +} + +static int icmp_checkentry(const struct xt_mtchk_param *par) +{ + const struct ipt_icmp *icmpinfo = par->matchinfo; + + return (icmpinfo->invflags & ~IPT_ICMP_INV) ? -EINVAL : 0; +} + +static int icmp6_checkentry(const struct xt_mtchk_param *par) +{ + const struct ip6t_icmp *icmpinfo = par->matchinfo; + + return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0; +} + static struct xt_match tcpudp_mt_reg[] __read_mostly = { { .name = "tcp", @@ -216,6 +308,24 @@ static struct xt_match tcpudp_mt_reg[] __read_mostly = { .proto = IPPROTO_UDPLITE, .me = THIS_MODULE, }, + { + .name = "icmp", + .match = icmp_match, + .matchsize = sizeof(struct ipt_icmp), + .checkentry = icmp_checkentry, + .proto = IPPROTO_ICMP, + .family = NFPROTO_IPV4, + .me = THIS_MODULE, + }, + { + .name = "icmp6", + .match = icmp6_match, + .matchsize = sizeof(struct ip6t_icmp), + .checkentry = icmp6_checkentry, + .proto = IPPROTO_ICMPV6, + .family = NFPROTO_IPV6, + .me = THIS_MODULE, + }, }; static int __init tcpudp_mt_init(void) |