diff options
Diffstat (limited to 'net/bridge/netfilter/ebt_snat.c')
| -rw-r--r-- | net/bridge/netfilter/ebt_snat.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/net/bridge/netfilter/ebt_snat.c b/net/bridge/netfilter/ebt_snat.c index cbb33e24ca8..a50722182bf 100644 --- a/net/bridge/netfilter/ebt_snat.c +++ b/net/bridge/netfilter/ebt_snat.c @@ -12,6 +12,8 @@ #include <linux/netfilter_bridge/ebt_nat.h> #include <linux/module.h> #include <net/sock.h> +#include <linux/if_arp.h> +#include <net/arp.h> static int ebt_target_snat(struct sk_buff **pskb, unsigned int hooknr, const struct net_device *in, const struct net_device *out, @@ -31,24 +33,43 @@ static int ebt_target_snat(struct sk_buff **pskb, unsigned int hooknr, *pskb = nskb; } memcpy(eth_hdr(*pskb)->h_source, info->mac, ETH_ALEN); - return info->target; + if (!(info->target & NAT_ARP_BIT) && + eth_hdr(*pskb)->h_proto == htons(ETH_P_ARP)) { + struct arphdr _ah, *ap; + + ap = skb_header_pointer(*pskb, 0, sizeof(_ah), &_ah); + if (ap == NULL) + return EBT_DROP; + if (ap->ar_hln != ETH_ALEN) + goto out; + if (skb_store_bits(*pskb, sizeof(_ah), info->mac,ETH_ALEN)) + return EBT_DROP; + } +out: + return info->target | ~EBT_VERDICT_BITS; } static int ebt_target_snat_check(const char *tablename, unsigned int hookmask, const struct ebt_entry *e, void *data, unsigned int datalen) { struct ebt_nat_info *info = (struct ebt_nat_info *) data; + int tmp; if (datalen != EBT_ALIGN(sizeof(struct ebt_nat_info))) return -EINVAL; - if (BASE_CHAIN && info->target == EBT_RETURN) + tmp = info->target | ~EBT_VERDICT_BITS; + if (BASE_CHAIN && tmp == EBT_RETURN) return -EINVAL; CLEAR_BASE_CHAIN_BIT; if (strcmp(tablename, "nat")) return -EINVAL; if (hookmask & ~(1 << NF_BR_POST_ROUTING)) return -EINVAL; - if (INVALID_TARGET) + + if (tmp < -NUM_STANDARD_TARGETS || tmp >= 0) + return -EINVAL; + tmp = info->target | EBT_VERDICT_BITS; + if ((tmp & ~NAT_ARP_BIT) != ~NAT_ARP_BIT) return -EINVAL; return 0; } |