Move main() out of clatd.c.

This allows us to unit test methods that are in clatd.c.
Also simplify the build file, adding a defaults stanza and
grouping files in a filegroup so that both the code and the unit
test have the same source files.

Test: atest clatd_test
Test: builds, boots, 464xlat works
Change-Id: I544c3ee846abd3e38b80a2d9a4db5497fd9beb0c

1 files changed, 0 insertions, 110 deletions

diff --git a/clatd.c b/clatd.c
index 18d7562..2ef10a5 100644
--- a/clatd.c
+++ b/clatd.c
@@ -53,8 +53,6 @@
 #include "translate.h"
 #include "tun.h"
 
-#define DEVICEPREFIX "v4-"
-
 /* 40 bytes IPv6 header - 20 bytes IPv4 header + 8 bytes fragment header */
 #define MTU_DELTA 28
 
@@ -426,17 +424,6 @@ void event_loop(struct tun_data *tunnel) {
   }
 }
 
-/* function: print_help
- * in case the user is running this on the command line
- */
-void print_help() {
-  printf("android-clat arguments:\n");
-  printf("-i [uplink interface]\n");
-  printf("-p [plat prefix]\n");
-  printf("-n [NetId]\n");
-  printf("-m [socket mark]\n");
-}
-
 /* function: parse_unsigned
  * parses a string as a decimal/hex/octal unsigned integer
  *   str - the string to parse
@@ -447,100 +434,3 @@ int parse_unsigned(const char *str, unsigned *out) {
   *out = strtoul(str, &end_ptr, 0);
   return *str && !*end_ptr;
 }
-
-/* function: main
- * allocate and setup the tun device, then run the event loop
- */
-int main(int argc, char **argv) {
-  struct tun_data tunnel;
-  int opt;
-  char *uplink_interface = NULL, *plat_prefix = NULL, *net_id_str = NULL, *mark_str = NULL;
-  unsigned net_id = NETID_UNSET;
-  uint32_t mark   = MARK_UNSET;
-  unsigned len;
-
-  while ((opt = getopt(argc, argv, "i:p:n:m:h")) != -1) {
-    switch (opt) {
-      case 'i':
-        uplink_interface = optarg;
-        break;
-      case 'p':
-        plat_prefix = optarg;
-        break;
-      case 'n':
-        net_id_str = optarg;
-        break;
-      case 'm':
-        mark_str = optarg;
-        break;
-      case 'h':
-        print_help();
-        exit(0);
-      default:
-        logmsg(ANDROID_LOG_FATAL, "Unknown option -%c. Exiting.", (char)optopt);
-        exit(1);
-    }
-  }
-
-  if (uplink_interface == NULL) {
-    logmsg(ANDROID_LOG_FATAL, "clatd called without an interface");
-    exit(1);
-  }
-
-  if (net_id_str != NULL && !parse_unsigned(net_id_str, &net_id)) {
-    logmsg(ANDROID_LOG_FATAL, "invalid NetID %s", net_id_str);
-    exit(1);
-  }
-
-  if (mark_str != NULL && !parse_unsigned(mark_str, &mark)) {
-    logmsg(ANDROID_LOG_FATAL, "invalid mark %s", mark_str);
-    exit(1);
-  }
-
-  len = snprintf(tunnel.device4, sizeof(tunnel.device4), "%s%s", DEVICEPREFIX, uplink_interface);
-  if (len >= sizeof(tunnel.device4)) {
-    logmsg(ANDROID_LOG_FATAL, "interface name too long '%s'", tunnel.device4);
-    exit(1);
-  }
-
-  logmsg(ANDROID_LOG_INFO, "Starting clat version %s on %s netid=%s mark=%s", CLATD_VERSION,
-         uplink_interface, net_id_str ? net_id_str : "(none)", mark_str ? mark_str : "(none)");
-
-  // run under a regular user but keep needed capabilities
-  drop_root_but_keep_caps();
-
-  // open our raw sockets before dropping privs
-  open_sockets(&tunnel, mark);
-
-  // keeps only admin capability
-  set_capability(1 << CAP_NET_ADMIN);
-
-  // we can create tun devices as non-root because we're in the VPN group.
-  tunnel.fd4 = tun_open();
-  if (tunnel.fd4 < 0) {
-    logmsg(ANDROID_LOG_FATAL, "tun_open4 failed: %s", strerror(errno));
-    exit(1);
-  }
-
-  // When run from netd, the environment variable ANDROID_DNS_MODE is set to
-  // "local", but that only works for the netd process itself. Removing the
-  // following line causes XLAT failure in permissive mode.
-  unsetenv("ANDROID_DNS_MODE");
-
-  configure_interface(uplink_interface, plat_prefix, &tunnel, net_id);
-
-  update_clat_ipv6_address(&tunnel, uplink_interface);
-
-  // Loop until someone sends us a signal or brings down the tun interface.
-  if (signal(SIGTERM, stop_loop) == SIG_ERR) {
-    logmsg(ANDROID_LOG_FATAL, "sigterm handler failed: %s", strerror(errno));
-    exit(1);
-  }
-
-  event_loop(&tunnel);
-
-  logmsg(ANDROID_LOG_INFO, "Shutting down clat on %s", uplink_interface);
-  del_anycast_address(tunnel.write_fd6, &Global_Clatd_Config.ipv6_local_subnet);
-
-  return 0;
-}