int ifc_set_prefixLength(const char *name, int prefixLength)
{
struct ifreq ifr;
// TODO - support ipv6
if (prefixLength > 32 || prefixLength < 0) return -1;
in_addr_t mask = prefixLengthToIpv4Netmask(prefixLength);
ifc_init_ifr(name, &ifr);
init_sockaddr_in(&ifr.ifr_addr, mask);
return ioctl(ifc_ctl_sock, SIOCSIFNETMASK, &ifr);
}
int ifc_act_on_ipv4_route(int action, const char *ifname, struct in_addr dst, int prefix_length,
struct in_addr gw)
{
struct rtentry rt;
int result;
in_addr_t netmask;
memset(&rt, 0, sizeof(rt));
rt.rt_dst.sa_family = AF_INET;
rt.rt_dev = (void*) ifname;
netmask = prefixLengthToIpv4Netmask(prefix_length);
init_sockaddr_in(&rt.rt_genmask, netmask);
init_sockaddr_in(&rt.rt_dst, dst.s_addr);
rt.rt_flags = RTF_UP;
if (prefix_length == 32) {
rt.rt_flags |= RTF_HOST;
}
if (gw.s_addr != 0) {
rt.rt_flags |= RTF_GATEWAY;
init_sockaddr_in(&rt.rt_gateway, gw.s_addr);
}
ifc_init();
if (ifc_ctl_sock < 0) {
return -errno;
}
result = ioctl(ifc_ctl_sock, action, &rt);
if (result < 0) {
if (errno == EEXIST) {
result = 0;
} else {
result = -errno;
}
}
ifc_close();
return result;
}
struct ifaddrs *get_interface(const char *name, sa_family_t family)
{
unsigned addr, flags;
int masklen;
struct ifaddrs *ifa;
struct sockaddr_in *saddr = NULL;
struct sockaddr_in *smask = NULL;
struct sockaddr_ll *hwaddr = NULL;
unsigned char hwbuf[ETH_ALEN];
if (ifc_get_info(name, &addr, &masklen, &flags))
return NULL;
if ((family == AF_INET) && (addr == 0))
return NULL;
ifa = malloc(sizeof(struct ifaddrs));
if (!ifa)
return NULL;
memset(ifa, 0, sizeof(struct ifaddrs));
ifa->ifa_name = malloc(strlen(name)+1);
if (!ifa->ifa_name) {
free(ifa);
return NULL;
}
strcpy(ifa->ifa_name, name);
ifa->ifa_flags = flags;
if (family == AF_INET) {
saddr = malloc(sizeof(struct sockaddr_in));
if (saddr) {
saddr->sin_addr.s_addr = addr;
saddr->sin_family = family;
}
ifa->ifa_addr = (struct sockaddr *)saddr;
if (masklen != 0) {
smask = malloc(sizeof(struct sockaddr_in));
if (smask) {
smask->sin_addr.s_addr = prefixLengthToIpv4Netmask(masklen);
smask->sin_family = family;
}
}
ifa->ifa_netmask = (struct sockaddr *)smask;
} else if (family == AF_PACKET) {
if (!ifc_get_hwaddr(name, hwbuf)) {
hwaddr = malloc(sizeof(struct sockaddr_ll));
if (hwaddr) {
memset(hwaddr, 0, sizeof(struct sockaddr_ll));
hwaddr->sll_family = family;
/* hwaddr->sll_protocol = ETHERTYPE_IP; */
hwaddr->sll_hatype = ARPHRD_ETHER;
hwaddr->sll_halen = ETH_ALEN;
memcpy(hwaddr->sll_addr, hwbuf, ETH_ALEN);
}
}
ifa->ifa_addr = (struct sockaddr *)hwaddr;
ifa->ifa_netmask = (struct sockaddr *)smask;
}
return ifa;
}
