diff options
| -rw-r--r-- | include/linux/netfilter_bridge/ebt_arp.h | 4 | ||||
| -rw-r--r-- | net/bridge/netfilter/ebt_arp.c | 48 |
2 files changed, 25 insertions, 27 deletions
diff --git a/include/linux/netfilter_bridge/ebt_arp.h b/include/linux/netfilter_bridge/ebt_arp.h index 97e4dbd..cbf4843 100644 --- a/include/linux/netfilter_bridge/ebt_arp.h +++ b/include/linux/netfilter_bridge/ebt_arp.h @@ -8,8 +8,10 @@ #define EBT_ARP_DST_IP 0x10 #define EBT_ARP_SRC_MAC 0x20 #define EBT_ARP_DST_MAC 0x40 +#define EBT_ARP_GRAT 0x80 #define EBT_ARP_MASK (EBT_ARP_OPCODE | EBT_ARP_HTYPE | EBT_ARP_PTYPE | \ - EBT_ARP_SRC_IP | EBT_ARP_DST_IP | EBT_ARP_SRC_MAC | EBT_ARP_DST_MAC) + EBT_ARP_SRC_IP | EBT_ARP_DST_IP | EBT_ARP_SRC_MAC | EBT_ARP_DST_MAC | \ + EBT_ARP_GRAT) #define EBT_ARP_MATCH "arp" struct ebt_arp_info diff --git a/net/bridge/netfilter/ebt_arp.c b/net/bridge/netfilter/ebt_arp.c index 9c59980..1a46952 100644 --- a/net/bridge/netfilter/ebt_arp.c +++ b/net/bridge/netfilter/ebt_arp.c @@ -35,40 +35,36 @@ static int ebt_filter_arp(const struct sk_buff *skb, const struct net_device *in return EBT_NOMATCH; if (info->bitmask & (EBT_ARP_SRC_IP | EBT_ARP_DST_IP)) { - __be32 _addr, *ap; + __be32 saddr, daddr, *sap, *dap; - /* IPv4 addresses are always 4 bytes */ - if (ah->ar_pln != sizeof(__be32)) + if (ah->ar_pln != sizeof(__be32) || ah->ar_pro != htons(ETH_P_IP)) + return EBT_NOMATCH; + sap = skb_header_pointer(skb, sizeof(struct arphdr) + + ah->ar_hln, sizeof(saddr), + &saddr); + if (sap == NULL) + return EBT_NOMATCH; + dap = skb_header_pointer(skb, sizeof(struct arphdr) + + 2*ah->ar_hln+sizeof(saddr), + sizeof(daddr), &daddr); + if (dap == NULL) + return EBT_NOMATCH; + if (info->bitmask & EBT_ARP_SRC_IP && + FWINV(info->saddr != (*sap & info->smsk), EBT_ARP_SRC_IP)) + return EBT_NOMATCH; + if (info->bitmask & EBT_ARP_DST_IP && + FWINV(info->daddr != (*dap & info->dmsk), EBT_ARP_DST_IP)) + return EBT_NOMATCH; + if (info->bitmask & EBT_ARP_GRAT && + FWINV(*dap != *sap, EBT_ARP_GRAT)) return EBT_NOMATCH; - if (info->bitmask & EBT_ARP_SRC_IP) { - ap = skb_header_pointer(skb, sizeof(struct arphdr) + - ah->ar_hln, sizeof(_addr), - &_addr); - if (ap == NULL) - return EBT_NOMATCH; - if (FWINV(info->saddr != (*ap & info->smsk), - EBT_ARP_SRC_IP)) - return EBT_NOMATCH; - } - - if (info->bitmask & EBT_ARP_DST_IP) { - ap = skb_header_pointer(skb, sizeof(struct arphdr) + - 2*ah->ar_hln+sizeof(__be32), - sizeof(_addr), &_addr); - if (ap == NULL) - return EBT_NOMATCH; - if (FWINV(info->daddr != (*ap & info->dmsk), - EBT_ARP_DST_IP)) - return EBT_NOMATCH; - } } if (info->bitmask & (EBT_ARP_SRC_MAC | EBT_ARP_DST_MAC)) { unsigned char _mac[ETH_ALEN], *mp; uint8_t verdict, i; - /* MAC addresses are 6 bytes */ - if (ah->ar_hln != ETH_ALEN) + if (ah->ar_hln != ETH_ALEN || ah->ar_hrd != htons(ARPHRD_ETHER)) return EBT_NOMATCH; if (info->bitmask & EBT_ARP_SRC_MAC) { mp = skb_header_pointer(skb, sizeof(struct arphdr), |