tun: Convert tun_ipv6_linklocal_get to be more generic
Add support for IPv4 and IPv6 global IPs. Also return the prefix length
of the IP address by using a in46_prefix.
Change-Id: I277af191dc611b6bbcb83479f4ae338083740322
diff --git a/lib/tun.c b/lib/tun.c
index 7662146..6bcc13b 100644
--- a/lib/tun.c
+++ b/lib/tun.c
@@ -751,34 +751,73 @@
#include <ifaddrs.h>
-/* obtain the link-local address of the tun device */
-int tun_ipv6_linklocal_get(const struct tun_t *tun, struct in6_addr *ia)
+/*! Obtain the local address of the tun device.
+ * \param[in] tun Target device owning the IP
+ * \param[out] prefix_list List of prefix structures to fill with each IPv4/6 and prefix length found.
+ * \param[in] prefix_size Amount of elements allowed to be fill in the prefix_list array.
+ * \param[in] flags Specify which kind of IP to look for: IP_TYPE_IPv4, IP_TYPE_IPv6_LINK, IP_TYPE_IPv6_NONLINK
+ * \returns The number of ips found following the criteria specified by flags, -1 on error.
+ *
+ * This function will fill prefix_list with up to prefix_size IPs following the
+ * criteria specified by flags parameter. It returns the number of IPs matching
+ * the criteria. As a result, the number returned can be bigger than
+ * prefix_size. It can be used with prefix_size=0 to get an estimate of the size
+ * needed for prefix_list.
+ */
+int tun_ip_local_get(const struct tun_t *tun, struct in46_prefix *prefix_list, size_t prefix_size, int flags)
{
- struct ifaddrs *ifaddr, *ifa;
static const uint8_t ll_prefix[] = { 0xfe,0x80, 0,0, 0,0, 0,0 };
+ struct ifaddrs *ifaddr, *ifa;
+ struct in46_addr netmask;
+ size_t count = 0;
+ bool is_ipv6_ll;
if (getifaddrs(&ifaddr) == -1) {
return -1;
}
for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
- struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) ifa->ifa_addr;
if (ifa->ifa_addr == NULL)
continue;
- if (ifa->ifa_addr->sa_family != AF_INET6)
- continue;
-
if (strcmp(ifa->ifa_name, tun->devname))
continue;
- if (memcmp(sin6->sin6_addr.s6_addr, ll_prefix, sizeof(ll_prefix)))
- continue;
+ if (ifa->ifa_addr->sa_family == AF_INET && (flags & IP_TYPE_IPv4)) {
+ struct sockaddr_in *sin4 = (struct sockaddr_in *) ifa->ifa_addr;
+ struct sockaddr_in *netmask4 = (struct sockaddr_in *) ifa->ifa_netmask;
- *ia = sin6->sin6_addr;
- freeifaddrs(ifaddr);
- return 0;
+ if (count < prefix_size) {
+ netmask.len = sizeof(netmask4->sin_addr);
+ netmask.v4 = netmask4->sin_addr;
+ prefix_list[count].addr.len = sizeof(sin4->sin_addr);
+ prefix_list[count].addr.v4 = sin4->sin_addr;
+ prefix_list[count].prefixlen = in46a_netmasklen(&netmask);
+ }
+ count++;
+ }
+
+ if (ifa->ifa_addr->sa_family == AF_INET6 && (flags & IP_TYPE_IPv6)) {
+ struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) ifa->ifa_addr;
+ struct sockaddr_in6 *netmask6 = (struct sockaddr_in6 *) ifa->ifa_netmask;
+
+ is_ipv6_ll = !memcmp(sin6->sin6_addr.s6_addr, ll_prefix, sizeof(ll_prefix));
+ if ((flags & IP_TYPE_IPv6_NONLINK) && is_ipv6_ll)
+ continue;
+ if ((flags & IP_TYPE_IPv6_LINK) && !is_ipv6_ll)
+ continue;
+
+ if (count < prefix_size) {
+ netmask.len = sizeof(netmask6->sin6_addr);
+ netmask.v6 = netmask6->sin6_addr;
+ prefix_list[count].addr.len = sizeof(sin6->sin6_addr);
+ prefix_list[count].addr.v6 = sin6->sin6_addr;
+ prefix_list[count].prefixlen = in46a_netmasklen(&netmask);
+ }
+ count++;
+ }
}
+
freeifaddrs(ifaddr);
- return -1;
+ return count;
}