/* Returns whether packet matches rule or not. */
static inline int arp_packet_match(const struct arphdr *arphdr,
struct net_device *dev,
const char *indev,
const char *outdev,
const struct arpt_arp *arpinfo)
{
const char *arpptr = (char *)(arphdr + 1);
const char *src_devaddr, *tgt_devaddr;
__be32 src_ipaddr, tgt_ipaddr;
long ret;
#define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
ARPT_INV_ARPOP)) {
dprintf("ARP operation field mismatch.\n");
dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
return 0;
}
if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
ARPT_INV_ARPHRD)) {
dprintf("ARP hardware address format mismatch.\n");
dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
return 0;
}
if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
ARPT_INV_ARPPRO)) {
dprintf("ARP protocol address format mismatch.\n");
dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
return 0;
}
if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
ARPT_INV_ARPHLN)) {
dprintf("ARP hardware address length mismatch.\n");
dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
return 0;
}
src_devaddr = arpptr;
arpptr += dev->addr_len;
memcpy(&src_ipaddr, arpptr, sizeof(u32));
arpptr += sizeof(u32);
tgt_devaddr = arpptr;
arpptr += dev->addr_len;
memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
ARPT_INV_SRCDEVADDR) ||
FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
ARPT_INV_TGTDEVADDR)) {
dprintf("Source or target device address mismatch.\n");
return 0;
}
if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
ARPT_INV_SRCIP) ||
FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
ARPT_INV_TGTIP)) {
dprintf("Source or target IP address mismatch.\n");
dprintf("SRC: %pI4. Mask: %pI4. Target: %pI4.%s\n",
&src_ipaddr,
&arpinfo->smsk.s_addr,
&arpinfo->src.s_addr,
arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
dprintf("TGT: %pI4 Mask: %pI4 Target: %pI4.%s\n",
&tgt_ipaddr,
&arpinfo->tmsk.s_addr,
&arpinfo->tgt.s_addr,
arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
return 0;
}
/* Look for ifname matches. */
ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask);
if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
dprintf("VIA in mismatch (%s vs %s).%s\n",
indev, arpinfo->iniface,
arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
return 0;
}
ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask);
if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
dprintf("VIA out mismatch (%s vs %s).%s\n",
outdev, arpinfo->outiface,
arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
return 0;
}
return 1;
#undef FWINV
}
/* Returns whether packet matches rule or not. */
static inline int arp_packet_match(const struct arphdr *arphdr,
struct net_device *dev,
const char *indev,
const char *outdev,
const struct arpt_arp *arpinfo)
{
const char *arpptr = (char *)(arphdr + 1);
const char *src_devaddr, *tgt_devaddr;
__be32 src_ipaddr, tgt_ipaddr;
long ret;
if (NF_INVF(arpinfo, ARPT_INV_ARPOP,
(arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop))
return 0;
if (NF_INVF(arpinfo, ARPT_INV_ARPHRD,
(arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd))
return 0;
if (NF_INVF(arpinfo, ARPT_INV_ARPPRO,
(arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro))
return 0;
if (NF_INVF(arpinfo, ARPT_INV_ARPHLN,
(arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln))
return 0;
src_devaddr = arpptr;
arpptr += dev->addr_len;
memcpy(&src_ipaddr, arpptr, sizeof(u32));
arpptr += sizeof(u32);
tgt_devaddr = arpptr;
arpptr += dev->addr_len;
memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
if (NF_INVF(arpinfo, ARPT_INV_SRCDEVADDR,
arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr,
dev->addr_len)) ||
NF_INVF(arpinfo, ARPT_INV_TGTDEVADDR,
arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr,
dev->addr_len)))
return 0;
if (NF_INVF(arpinfo, ARPT_INV_SRCIP,
(src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr) ||
NF_INVF(arpinfo, ARPT_INV_TGTIP,
(tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr))
return 0;
/* Look for ifname matches. */
ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask);
if (NF_INVF(arpinfo, ARPT_INV_VIA_IN, ret != 0))
return 0;
ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask);
if (NF_INVF(arpinfo, ARPT_INV_VIA_OUT, ret != 0))
return 0;
return 1;
}