Add listening support.
diff --git a/nc.c b/nc.c
index 682da82..3f512d1 100644
--- a/nc.c
+++ b/nc.c
@@ -41,7 +41,7 @@
int nc_main(int argc, char **argv)
{
- int sfd;
+ int do_listen = 0, lport = 0, tmpfd, opt, sfd;
char buf[BUFSIZ];
struct sockaddr_in address;
@@ -49,24 +49,54 @@
fd_set readfds, testfds;
- argc--;
- argv++;
- if (argc < 2 || **argv == '-') {
- usage(nc_usage);
+ while ((opt = getopt(argc, argv, "lp:")) > 0) {
+ switch (opt) {
+ case 'l':
+ do_listen++;
+ break;
+ case 'p':
+ lport = atoi(optarg);
+ break;
+ default:
+ usage(nc_usage);
+ }
}
+ if ((do_listen && optind != argc) || (!do_listen && optind + 2 != argc))
+ usage(nc_usage);
+
if ((sfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
perror_msg_and_die("socket");
- if ((hostinfo = gethostbyname(*argv)) == NULL)
- error_msg_and_die("cannot resolve %s", *argv);
-
address.sin_family = AF_INET;
- address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
- address.sin_port = htons(atoi(*(++argv)));
- if (connect(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
- perror_msg_and_die("connect");
+ if (lport != 0) {
+ memset(&address.sin_addr, 0, sizeof(address.sin_addr));
+ address.sin_port = htons(lport);
+
+ if (bind(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
+ perror_msg_and_die("bind");
+ }
+
+ if (do_listen) {
+ if (listen(sfd, 1) < 0)
+ perror_msg_and_die("listen");
+
+ if ((tmpfd = accept(sfd, (struct sockaddr *) &address, &opt)) < 0)
+ perror_msg_and_die("accept");
+
+ close(sfd);
+ sfd = tmpfd;
+ } else {
+ if ((hostinfo = gethostbyname(argv[optind])) == NULL)
+ error_msg_and_die("cannot resolve %s\n", argv[optind]);
+
+ address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
+ address.sin_port = htons(atoi(argv[optind+1]));
+
+ if (connect(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
+ perror_msg_and_die("connect");
+ }
FD_ZERO(&readfds);
FD_SET(sfd, &readfds);