MODULE_DESCRIPTION("Netfilter NAT protocol helper module for GRE");
/* generate unique tuple ... */
-static int
+static bool
gre_unique_tuple(struct nf_conntrack_tuple *tuple,
const struct nf_nat_range *range,
enum nf_nat_manip_type maniptype,
/* If there is no master conntrack we are not PPTP,
do not change tuples */
if (!ct->master)
- return 0;
+ return false;
if (maniptype == IP_NAT_MANIP_SRC)
keyptr = &tuple->src.u.gre.key;
for (i = 0; i < range_size; i++, key++) {
*keyptr = htons(min + key % range_size);
if (!nf_nat_used_tuple(tuple, ct))
- return 1;
+ return true;
}
pr_debug("%p: no NAT mapping\n", ct);
- return 0;
+ return false;
}
/* manipulate a GRE packet according to maniptype */
-static int
+static bool
gre_manip_pkt(struct sk_buff *skb, unsigned int iphdroff,
const struct nf_conntrack_tuple *tuple,
enum nf_nat_manip_type maniptype)
{
- struct gre_hdr *greh;
+ const struct gre_hdr *greh;
struct gre_hdr_pptp *pgreh;
const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
unsigned int hdroff = iphdroff + iph->ihl * 4;
/* pgreh includes two optional 32bit fields which are not required
* to be there. That's where the magic '8' comes from */
if (!skb_make_writable(skb, hdroff + sizeof(*pgreh) - 8))
- return 0;
+ return false;
greh = (void *)skb->data + hdroff;
pgreh = (struct gre_hdr_pptp *)greh;
/* we only have destination manip of a packet, since 'source key'
* is not present in the packet itself */
if (maniptype != IP_NAT_MANIP_DST)
- return 1;
+ return true;
switch (greh->version) {
case GRE_VERSION_1701:
/* We do not currently NAT any GREv0 packets.
break;
default:
pr_debug("can't nat unknown GRE version\n");
- return 0;
+ return false;
}
- return 1;
+ return true;
}
static const struct nf_nat_protocol gre = {
- .name = "GRE",
.protonum = IPPROTO_GRE,
.me = THIS_MODULE,
.manip_pkt = gre_manip_pkt,