unsigned int
mroute_extract_addr_ipv4 (struct mroute_addr *src,
struct mroute_addr *dest,
const struct buffer *buf)
{
unsigned int ret = 0;
if (BLEN (buf) >= 1)
{
switch (OPENVPN_IPH_GET_VER (*BPTR(buf)))
{
case 4:
if (BLEN (buf) >= (int) sizeof (struct openvpn_iphdr))
{
const struct openvpn_iphdr *ip = (const struct openvpn_iphdr *) BPTR (buf);
mroute_get_in_addr_t (src, ip->saddr, 0);
mroute_get_in_addr_t (dest, ip->daddr, 0);
/* multicast packet? */
if (mroute_is_mcast (ip->daddr))
ret |= MROUTE_EXTRACT_MCAST;
/* IGMP message? */
if (ip->protocol == OPENVPN_IPPROTO_IGMP)
ret |= MROUTE_EXTRACT_IGMP;
ret |= MROUTE_EXTRACT_SUCCEEDED;
}
break;
case 6:
if (BLEN (buf) >= (int) sizeof (struct openvpn_ipv6hdr))
{
const struct openvpn_ipv6hdr *ipv6 = (const struct openvpn_ipv6hdr *) BPTR (buf);
#if 0 /* very basic debug */
struct gc_arena gc = gc_new ();
msg( M_INFO, "IPv6 packet! src=%s, dst=%s",
print_in6_addr( ipv6->saddr, 0, &gc ),
print_in6_addr( ipv6->daddr, 0, &gc ));
gc_free (&gc);
#endif
mroute_get_in6_addr (src, ipv6->saddr, 0);
mroute_get_in6_addr (dest, ipv6->daddr, 0);
if (mroute_is_mcast_ipv6 (ipv6->daddr))
ret |= MROUTE_EXTRACT_MCAST;
ret |= MROUTE_EXTRACT_SUCCEEDED;
}
break;
default:
msg (M_WARN, "IP packet with unknown IP version=%d seen",
OPENVPN_IPH_GET_VER (*BPTR(buf)));
}
}
return ret;
}
/*
* If raw tunnel packet is IPv4, return true and increment
* buffer offset to start of IP header.
*/
bool
is_ipv4 (int tunnel_type, struct buffer *buf)
{
int offset;
const struct openvpn_iphdr *ih;
verify_align_4 (buf);
if (tunnel_type == DEV_TYPE_TUN)
{
if (BLEN (buf) < (int) sizeof (struct openvpn_iphdr))
return false;
offset = 0;
}
else if (tunnel_type == DEV_TYPE_TAP)
{
const struct openvpn_ethhdr *eh;
if (BLEN (buf) < (int)(sizeof (struct openvpn_ethhdr)
+ sizeof (struct openvpn_iphdr)))
return false;
eh = (const struct openvpn_ethhdr *) BPTR (buf);
if (ntohs (eh->proto) != OPENVPN_ETH_P_IPV4)
return false;
offset = sizeof (struct openvpn_ethhdr);
}
else
return false;
ih = (const struct openvpn_iphdr *) (BPTR (buf) + offset);
if (OPENVPN_IPH_GET_VER (ih->version_len) == 4)
return buf_advance (buf, offset);
else
return false;
}
/*
* If raw tunnel packet is IPv<X>, return true and increment
* buffer offset to start of IP header.
*/
static
bool
is_ipv_X( int tunnel_type, struct buffer *buf, int ip_ver )
{
int offset;
const struct openvpn_iphdr *ih;
verify_align_4(buf);
if (tunnel_type == DEV_TYPE_TUN)
{
//tun类型，不包含以太头
if (BLEN(buf) < (int) sizeof(struct openvpn_iphdr))
{
return false;
}
offset = 0;
}
else if (tunnel_type == DEV_TYPE_TAP)
{
//tap类型，包含以太头
const struct openvpn_ethhdr *eh;
if (BLEN(buf) < (int)(sizeof(struct openvpn_ethhdr)
+ sizeof(struct openvpn_iphdr)))
{
return false;
}
eh = (const struct openvpn_ethhdr *) BPTR(buf);
if (ntohs(eh->proto) != (ip_ver == 6 ? OPENVPN_ETH_P_IPV6 : OPENVPN_ETH_P_IPV4))
{
//非指定协议，返回false
return false;
}
offset = sizeof(struct openvpn_ethhdr);
}
else
{
return false;
}
//指向ip头部
ih = (const struct openvpn_iphdr *) (BPTR(buf) + offset);
/* IP version is stored in the same bits for IPv4 or IPv6 header */
if (OPENVPN_IPH_GET_VER(ih->version_len) == ip_ver)
{
//为对应ip协议，使buf指向对应的ip头部
return buf_advance(buf, offset);
}
else
{
//非对应的ip协议，返回false
return false;
}
}
unsigned int
mroute_extract_addr_ipv4 (struct mroute_addr *src,
struct mroute_addr *dest,
const struct buffer *buf)
{
unsigned int ret = 0;
static bool ipv6warned = false;
if (BLEN (buf) >= 1)
{
switch (OPENVPN_IPH_GET_VER (*BPTR(buf)))
{
case 4:
if (BLEN (buf) >= (int) sizeof (struct openvpn_iphdr))
{
const struct openvpn_iphdr *ip = (const struct openvpn_iphdr *) BPTR (buf);
mroute_get_in_addr_t (src, ip->saddr, 0);
mroute_get_in_addr_t (dest, ip->daddr, 0);
/* multicast packet? */
if (mroute_is_mcast (ip->daddr))
ret |= MROUTE_EXTRACT_MCAST;
/* IGMP message? */
if (ip->protocol == OPENVPN_IPPROTO_IGMP)
ret |= MROUTE_EXTRACT_IGMP;
ret |= MROUTE_EXTRACT_SUCCEEDED;
}
break;
case 6:
{
if( !ipv6warned ) {
msg (M_WARN, "IPv6 in tun mode is not supported in OpenVPN 2.2");
ipv6warned = true;
}
break;
}
}
}
return ret;
}
/*
* If raw tunnel packet is IPv4, return true and increment
* buffer offset to start of IP header.
*/
bool
is_ipv4 (int tunnel_type, struct buffer *buf)
{
int offset;
const struct openvpn_iphdr *ih;
verify_align_4 (buf);
if (tunnel_type == DEV_TYPE_TUN)
{
if (BLEN (buf) < (int) sizeof (struct openvpn_iphdr))
return false;
offset = 0;
}
else if (tunnel_type == DEV_TYPE_TAP)
{
const struct openvpn_ethhdr *eh;
if (BLEN (buf) < (int)(sizeof (struct openvpn_ethhdr)
+ sizeof (struct openvpn_iphdr)))
return false;
eh = (const struct openvpn_ethhdr *) BPTR (buf);
if (ntohs (eh->proto) != OPENVPN_ETH_P_IPV4)
return false;
offset = sizeof (struct openvpn_ethhdr);
}
else
return false;
ih = (const struct openvpn_iphdr *) (BPTR (buf) + offset);
if (OPENVPN_IPH_GET_VER (ih->version_len) == 4)
{
/* struct in_addr x,y;
x.s_addr = ih->saddr;
y.s_addr = ih->daddr;
printf("\n src=%s,dest=%s", inet_ntoa(x),inet_ntoa(y));*/
return buf_advance (buf, offset);
}
else
return false;
}
unsigned int
mroute_extract_addr_ipv4 (struct mroute_addr *src,
struct mroute_addr *dest,
const struct buffer *buf)
{
unsigned int ret = 0;
if (BLEN (buf) >= 1)
{
switch (OPENVPN_IPH_GET_VER (*BPTR(buf)))
{
case 4:
if (BLEN (buf) >= (int) sizeof (struct openvpn_iphdr))
{
const struct openvpn_iphdr *ip = (const struct openvpn_iphdr *) BPTR (buf);
mroute_get_in_addr_t (src, ip->saddr, 0);
mroute_get_in_addr_t (dest, ip->daddr, 0);
/* multicast packet? */
if (mroute_is_mcast (ip->daddr))
ret |= MROUTE_EXTRACT_MCAST;
/* IGMP message? */
if (ip->protocol == OPENVPN_IPPROTO_IGMP)
ret |= MROUTE_EXTRACT_IGMP;
ret |= MROUTE_EXTRACT_SUCCEEDED;
}
break;
case 6:
{
msg (M_WARN, "Need IPv6 code in mroute_extract_addr_from_packet");
break;
}
}
}
return ret;
}