Support decimal integer representation of target addresses. Fixes #375

ncat/ncat_main.c

@@ -828,87 +828,99 @@ int main(int argc, char *argv[])
  host_list_to_set(o.denyset, deny_host_list);
  host_list_free(deny_host_list);
 
- if (optind == argc) {
+ int rc;
+ int num_ports = 0;
+ if (srcport != -1 && o.listen) {
+ /* Treat "ncat -l -p <port>" the same as "ncat -l <port>" for nc
+ compatibility. */
+ o.portno = (unsigned int) srcport;
+ num_ports++;
+ }
+ /* How many arguments are left? */
+ ncat_assert(optind <= argc);
+ switch (argc - optind) {
+ case 2:
 #if HAVE_SYS_UN_H
+ /* We do not use ports with Unix domain sockets. */
  if (o.af == AF_UNIX) {
- if (!o.listen)
- bye("You have to specify path to a socket to connect to.");
- else
- bye("You have to specify path to a socket to listen on.");
+ bye("Using Unix domain sockets and specifying port doesn't make sense.");
  }
 #endif
- /* Listen defaults to any address and DEFAULT_NCAT_PORT */
- if (!o.listen)
- bye("You must specify a host to connect to.");
- } else {
+ if (num_ports == 0)
+ o.portno = parseport(argv[optind + 1], max_port, "port");
+ num_ports++;
+ /* fall through: */
+ case 1:
 #if HAVE_SYS_UN_H
  if (o.af == AF_UNIX) {
  memset(&targetaddrs->addr.storage, 0, sizeof(struct sockaddr_un));
  targetaddrs->addr.un.sun_family = AF_UNIX;
  strncpy(targetaddrs->addr.un.sun_path, argv[optind], sizeof(targetaddrs->addr.un.sun_path));
  targetaddrs->addrlen = SUN_LEN(&targetaddrs->addr.un);
  o.sslservername = o.target = argv[optind];
- optind++;
- } else
+ break;
+ }
 #endif
 #if HAVE_LINUX_VM_SOCKETS_H
  if (o.af == AF_VSOCK) {
- if (!o.listen || optind + 1 < argc) {
- long long_cid;
+ long long_cid;
 
-  memset(&targetaddrs->addr.storage, 0, sizeof(struct sockaddr_vm));
-  targetaddrs->addr.vm.svm_family = AF_VSOCK;
+ memset(&targetaddrs->addr.storage, 0, sizeof(struct sockaddr_vm));
+ targetaddrs->addr.vm.svm_family = AF_VSOCK;
 
-  errno = 0;
-  long_cid = strtol(argv[optind], NULL, 10);
-  if (errno != 0 || long_cid <= 0 || long_cid > UINT32_MAX)
-  bye("Invalid CID \"%s\".", argv[optind]);
-  targetaddrs->addr.vm.svm_cid = long_cid;
+ errno = 0;
+ long_cid = strtol(argv[optind], NULL, 10);
+ if (errno != 0 || long_cid <= 0 || long_cid > UINT32_MAX)
+ bye("Invalid CID \"%s\".", argv[optind]);
+ targetaddrs->addr.vm.svm_cid = long_cid;
 
- targetaddrs->addrlen = sizeof(targetaddrs->addr.vm);
- o.sslservername = o.target = argv[optind];
- optind++;
- }
- } else
+ targetaddrs->addrlen = sizeof(targetaddrs->addr.vm);
+ o.sslservername = o.target = argv[optind];
+ break;
+ }
 #endif
- /* Resolve hostname if we're given one */
- if (strspn(argv[optind], "0123456789") != strlen(argv[optind])) {
- int rc;
-
- o.target = argv[optind];
- /* resolve hostname only if o.proxytype == NULL
- * targetss contains data already and you don't want remove them
- */
- if( !o.proxytype
- && (rc = resolve_multi(o.target, 0, targetaddrs, o.af)) != 0)
-
- bye("Could not resolve hostname \"%s\": %s.", o.target, gai_strerror(rc));
- if (!o.sslservername)
- o.sslservername = o.target;
- optind++;
- } else {
- if (!o.listen)
- bye("You must specify a host to connect to.");
+ /* Support ncat -l <port>, but otherwise assume ncat <target> */
+ if (num_ports == 0 && o.listen) {
+ o.portno = parseport(argv[optind], max_port, "port");
+ num_ports++;
+ break;
  }
- }
+ o.target = argv[optind];
+ /* resolve hostname only if o.proxytype == NULL
+ * targetss contains data already and you don't want remove them
+ */
+ if( !o.proxytype
+ && (rc = resolve_multi(o.target, 0, targetaddrs, o.af)) != 0)
 
- /* Whatever's left is the port number; there should be at most one. */
+ bye("Could not resolve hostname \"%s\": %s.", o.target, gai_strerror(rc));
+ if (!o.sslservername)
+ o.sslservername = o.target;
+ break;
+ case 0:
 #if HAVE_SYS_UN_H
- /* We do not use ports with Unix domain sockets. */
- if (o.af == AF_UNIX && optind > argc)
- bye("Using Unix domain sockets and specifying port doesn't make sense.");
+ if (o.af == AF_UNIX) {
+ bye("You must specify a path to a socket to %s.",
+ o.listen ? "listen on" : "connect to");
+ }
 #endif
+ /* Listen defaults to any address and DEFAULT_NCAT_PORT */
+ if (!o.listen)
+ bye("You must specify a host to connect to.");
+ break;
+ default:
+ if (num_ports == 0)
+ o.portno = parseport(argv[optind + 1], max_port, "port");
+ num_ports += argc - optind - 1;
+ break;
+ }
 
- if (optind + 1 < argc || (o.listen && srcport != -1 && optind + 1 == argc)) {
- loguser("Got more than one port specification:");
- if (o.listen && srcport != -1)
- loguser_noprefix(" %lld", srcport);
- for (; optind < argc; optind++)
- loguser_noprefix(" %s", argv[optind]);
+ if (num_ports > 1) {
+ loguser("Got more than one port specification: %u", o.portno);
+ for (rc = argc - num_ports + 1; rc < argc; rc++)
+ loguser_noprefix(" %s", argv[rc]);
  loguser_noprefix(". QUITTING.\n");
  exit(2);
- } else if (optind + 1 == argc)
- o.portno = parseport(argv[optind], max_port, "port");
+ }
 
  if (o.proxytype && !o.listen)
  ; /* Do nothing - port is already set to proxyport */
@@ -939,12 +951,7 @@ int main(int argc, char *argv[])
  }
  }
 
- if (srcport != -1) {
- if (o.listen) {
- /* Treat "ncat -l -p <port>" the same as "ncat -l <port>" for nc
- compatibility. */
- o.portno = (unsigned int) srcport;
- } else {
+ if (srcport != -1 && !o.listen) {
  if (srcaddr.storage.ss_family == AF_UNSPEC) {
  /* We have a source port but not an explicit source address;
  fill in an unspecified address of the same family as the
@@ -965,7 +972,6 @@ int main(int argc, char *argv[])
  else if (srcaddr.storage.ss_family == AF_VSOCK)
  srcaddr.vm.svm_port = (unsigned int) srcport;
 #endif
- }
  }
 
  if (o.proto == IPPROTO_UDP) {