diff options
Diffstat (limited to 'clatd.c')
| -rw-r--r-- | clatd.c | 22 |
1 files changed, 21 insertions, 1 deletions
@@ -157,6 +157,22 @@ int configure_packet_socket(int sock) { void configure_tun_ip(const struct tun_data *tunnel) { int status; + // Pick an IPv4 address to use by finding a free address in the configured prefix. Technically, + // there is a race here - if another clatd calls config_select_ipv4_address after we do, but + // before we call add_address, it can end up having the same IP address as we do. But the time + // window in which this can happen is extremely small, and even if we end up with a duplicate + // address, the only damage is that IPv4 TCP connections won't be reset until both interfaces go + // down. + in_addr_t localaddr = config_select_ipv4_address(&Global_Clatd_Config.ipv4_local_subnet, + Global_Clatd_Config.ipv4_local_prefixlen); + if (localaddr == INADDR_NONE) { + logmsg(ANDROID_LOG_FATAL,"No free IPv4 address in %s/%d", + inet_ntoa(Global_Clatd_Config.ipv4_local_subnet), + Global_Clatd_Config.ipv4_local_prefixlen); + exit(1); + } + Global_Clatd_Config.ipv4_local_subnet.s_addr = localaddr; + // Configure the interface before bringing it up. As soon as we bring the interface up, the // framework will be notified and will assume the interface's configuration has been finalized. status = add_address(tunnel->device4, AF_INET, &Global_Clatd_Config.ipv4_local_subnet, @@ -166,6 +182,10 @@ void configure_tun_ip(const struct tun_data *tunnel) { exit(1); } + char addrstr[INET_ADDRSTRLEN]; + inet_ntop(AF_INET, &Global_Clatd_Config.ipv4_local_subnet, addrstr, sizeof(addrstr)); + logmsg(ANDROID_LOG_INFO, "Using IPv4 address %s on %s", addrstr, tunnel->device4); + if((status = if_up(tunnel->device4, Global_Clatd_Config.ipv4mtu)) < 0) { logmsg(ANDROID_LOG_FATAL,"configure_tun_ip/if_up(4) failed: %s",strerror(-status)); exit(1); @@ -269,7 +289,7 @@ int update_clat_ipv6_address(const struct tun_data *tunnel, const char *interfac if (IN6_IS_ADDR_UNSPECIFIED(&Global_Clatd_Config.ipv6_local_subnet)) { // Startup. - logmsg(ANDROID_LOG_INFO, "Using %s on %s", addrstr, interface); + logmsg(ANDROID_LOG_INFO, "Using IPv6 address %s on %s", addrstr, interface); } else { // Prefix change. char from_addr[INET6_ADDRSTRLEN]; |