diff options
author | Matthias Schiffer <mschiffer@universe-factory.net> | 2018-03-04 09:28:53 +0100 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-03-20 17:24:03 +0100 |
commit | 5adc1668ddc42bb44fd6d006cacad74ed0cbf49d (patch) | |
tree | efcd9577e837f6a224e81b09ee150aa9d4d857b8 | |
parent | 20710b3b81895c89e92bcc32ce85c0bede1171f8 (diff) | |
download | linux-5adc1668ddc42bb44fd6d006cacad74ed0cbf49d.tar.bz2 |
netfilter: ebtables: add support for matching ICMP type and code
We already have ICMPv6 type/code matches. This adds support for IPv4 ICMP
matches in the same way.
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r-- | include/uapi/linux/netfilter_bridge/ebt_ip.h | 13 | ||||
-rw-r--r-- | net/bridge/netfilter/ebt_ip.c | 43 |
2 files changed, 43 insertions, 13 deletions
diff --git a/include/uapi/linux/netfilter_bridge/ebt_ip.h b/include/uapi/linux/netfilter_bridge/ebt_ip.h index 8e462fb1983f..4ed7fbb0a482 100644 --- a/include/uapi/linux/netfilter_bridge/ebt_ip.h +++ b/include/uapi/linux/netfilter_bridge/ebt_ip.h @@ -24,8 +24,9 @@ #define EBT_IP_PROTO 0x08 #define EBT_IP_SPORT 0x10 #define EBT_IP_DPORT 0x20 +#define EBT_IP_ICMP 0x40 #define EBT_IP_MASK (EBT_IP_SOURCE | EBT_IP_DEST | EBT_IP_TOS | EBT_IP_PROTO |\ - EBT_IP_SPORT | EBT_IP_DPORT ) + EBT_IP_SPORT | EBT_IP_DPORT | EBT_IP_ICMP) #define EBT_IP_MATCH "ip" /* the same values are used for the invflags */ @@ -38,8 +39,14 @@ struct ebt_ip_info { __u8 protocol; __u8 bitmask; __u8 invflags; - __u16 sport[2]; - __u16 dport[2]; + union { + __u16 sport[2]; + __u8 icmp_type[2]; + }; + union { + __u16 dport[2]; + __u8 icmp_code[2]; + }; }; #endif diff --git a/net/bridge/netfilter/ebt_ip.c b/net/bridge/netfilter/ebt_ip.c index 2b46c50abce0..8cb8f8395768 100644 --- a/net/bridge/netfilter/ebt_ip.c +++ b/net/bridge/netfilter/ebt_ip.c @@ -19,9 +19,15 @@ #include <linux/netfilter_bridge/ebtables.h> #include <linux/netfilter_bridge/ebt_ip.h> -struct tcpudphdr { - __be16 src; - __be16 dst; +union pkthdr { + struct { + __be16 src; + __be16 dst; + } tcpudphdr; + struct { + u8 type; + u8 code; + } icmphdr; }; static bool @@ -30,8 +36,8 @@ ebt_ip_mt(const struct sk_buff *skb, struct xt_action_param *par) const struct ebt_ip_info *info = par->matchinfo; const struct iphdr *ih; struct iphdr _iph; - const struct tcpudphdr *pptr; - struct tcpudphdr _ports; + const union pkthdr *pptr; + union pkthdr _pkthdr; ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); if (ih == NULL) @@ -50,29 +56,38 @@ ebt_ip_mt(const struct sk_buff *skb, struct xt_action_param *par) if (info->bitmask & EBT_IP_PROTO) { if (NF_INVF(info, EBT_IP_PROTO, info->protocol != ih->protocol)) return false; - if (!(info->bitmask & EBT_IP_DPORT) && - !(info->bitmask & EBT_IP_SPORT)) + if (!(info->bitmask & (EBT_IP_DPORT | EBT_IP_SPORT | + EBT_IP_ICMP))) return true; if (ntohs(ih->frag_off) & IP_OFFSET) return false; + + /* min icmp headersize is 4, so sizeof(_pkthdr) is ok. */ pptr = skb_header_pointer(skb, ih->ihl*4, - sizeof(_ports), &_ports); + sizeof(_pkthdr), &_pkthdr); if (pptr == NULL) return false; if (info->bitmask & EBT_IP_DPORT) { - u32 dst = ntohs(pptr->dst); + u32 dst = ntohs(pptr->tcpudphdr.dst); if (NF_INVF(info, EBT_IP_DPORT, dst < info->dport[0] || dst > info->dport[1])) return false; } if (info->bitmask & EBT_IP_SPORT) { - u32 src = ntohs(pptr->src); + u32 src = ntohs(pptr->tcpudphdr.src); if (NF_INVF(info, EBT_IP_SPORT, src < info->sport[0] || src > info->sport[1])) return false; } + if ((info->bitmask & EBT_IP_ICMP) && + NF_INVF(info, EBT_IP_ICMP, + pptr->icmphdr.type < info->icmp_type[0] || + pptr->icmphdr.type > info->icmp_type[1] || + pptr->icmphdr.code < info->icmp_code[0] || + pptr->icmphdr.code > info->icmp_code[1])) + return false; } return true; } @@ -101,6 +116,14 @@ static int ebt_ip_mt_check(const struct xt_mtchk_param *par) return -EINVAL; if (info->bitmask & EBT_IP_SPORT && info->sport[0] > info->sport[1]) return -EINVAL; + if (info->bitmask & EBT_IP_ICMP) { + if ((info->invflags & EBT_IP_PROTO) || + info->protocol != IPPROTO_ICMP) + return -EINVAL; + if (info->icmp_type[0] > info->icmp_type[1] || + info->icmp_code[0] > info->icmp_code[1]) + return -EINVAL; + } return 0; } |