add a simplistic TELNET client utility
diff --git a/Makefile b/Makefile
index 81847dd..4ee0d16 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,10 @@
CFLAGS = -Wall -g -O0 -DHAVE_ZLIB -DENABLE_COLOR
LFLAGS = -lz
+all: telnet-proxy telnet-client
+
telnet-proxy: telnet-proxy.c libtelnet.c libtelnet.h Makefile
$(CC) -o telnet-proxy $(CFLAGS) telnet-proxy.c libtelnet.c $(LFLAGS)
+
+telnet-client: telnet-client.c libtelnet.c libtelnet.h Makefile
+ $(CC) -o telnet-client $(CFLAGS) telnet-client.c libtelnet.c $(LFLAGS)
diff --git a/telnet-client.c b/telnet-client.c
new file mode 100644
index 0000000..b8e1a69
--- /dev/null
+++ b/telnet-client.c
@@ -0,0 +1,172 @@
+/*
+ * Sean Middleditch
+ * sean@sourcemud.org
+ *
+ * The author or authors of this code dedicate any and all copyright interest
+ * in this code to the public domain. We make this dedication for the benefit
+ * of the public at large and to the detriment of our heirs and successors. We
+ * intend this dedication to be an overt act of relinquishment in perpetuity of
+ * all present and future rights to this code under copyright law.
+ */
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <poll.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <unistd.h>
+
+#ifdef HAVE_ZLIB
+#include "zlib.h"
+#endif
+
+#include "libtelnet.h"
+
+static void _send(int sock, unsigned char *buffer, unsigned int size) {
+ int rs;
+
+ /* send data */
+ while (size > 0) {
+ if ((rs = send(sock, buffer, size, 0)) == -1) {
+ fprintf(stderr, "send() failed: %s\n", strerror(errno));
+ exit(1);
+ } else if (rs == 0) {
+ fprintf(stderr, "send() unexpectedly returned 0\n");
+ exit(1);
+ }
+
+ /* update pointer and size to see if we've got more to send */
+ buffer += rs;
+ size -= rs;
+ }
+}
+
+static void _event_handler(struct libtelnet_t *telnet,
+ struct libtelnet_event_t *ev, void *user_data) {
+ int sock = *(int*)user_data;
+
+ switch (ev->type) {
+ /* data received */
+ case LIBTELNET_EV_DATA:
+ write(STDOUT_FILENO, ev->buffer, ev->size);
+ break;
+ /* data must be sent */
+ case LIBTELNET_EV_SEND:
+ _send(sock, ev->buffer, ev->size);
+ break;
+ /* accept any options we want */
+ case LIBTELNET_EV_NEGOTIATE:
+ /* enable COMPRESS2 */
+ if (ev->command == LIBTELNET_WILL &&
+ ev->telopt == LIBTELNET_TELOPT_COMPRESS2)
+ libtelnet_send_negotiate(telnet, LIBTELNET_DO, ev->telopt);
+ break;
+ /* error */
+ case LIBTELNET_EV_ERROR:
+ fprintf(stderr, "ERROR: %.*s\n", ev->size, ev->buffer);
+ exit(1);
+ default:
+ /* ignore */
+ break;
+ }
+}
+
+int main(int argc, char **argv) {
+ unsigned char buffer[512];
+ int rs;
+ int sock;
+ struct sockaddr_in addr;
+ struct pollfd pfd[2];
+ struct libtelnet_t telnet;
+ struct addrinfo *ai;
+ struct addrinfo hints;
+
+ /* check usage */
+ if (argc != 3) {
+ fprintf(stderr, "Usage:\n ./telnet-client <host> <port>\n");
+ return 1;
+ }
+
+ /* look up server host */
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+ if ((rs = getaddrinfo(argv[1], argv[2], &hints, &ai)) != 0) {
+ fprintf(stderr, "getaddrinfo() failed for %s: %s\n", argv[1],
+ gai_strerror(rs));
+ return 1;
+ }
+
+ /* create server socket */
+ if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
+ fprintf(stderr, "socket() failed: %s\n", strerror(errno));
+ return 1;
+ }
+
+ /* bind server socket */
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+ fprintf(stderr, "bind() failed: %s\n", strerror(errno));
+ return 1;
+ }
+
+ /* connect */
+ if (connect(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
+ fprintf(stderr, "server() failed: %s\n", strerror(errno));
+ return 1;
+ }
+
+ /* free address lookup info */
+ freeaddrinfo(ai);
+
+ /* initialize telnet box */
+ libtelnet_init(&telnet, _event_handler, LIBTELNET_MODE_CLIENT, &sock);
+
+ /* initialize poll descriptors */
+ memset(pfd, 0, sizeof(pfd));
+ pfd[0].fd = STDIN_FILENO;
+ pfd[0].events = POLLIN;
+ pfd[1].fd = sock;
+ pfd[1].events = POLLIN;
+
+ /* loop while both connections are open */
+ while (poll(pfd, 2, -1) != -1) {
+ /* read from stdin */
+ if (pfd[0].revents & POLLIN) {
+ if ((rs = read(STDIN_FILENO, buffer, sizeof(buffer))) > 0) {
+ libtelnet_send_data(&telnet, buffer, rs);
+ } else if (rs == 0) {
+ break;
+ } else {
+ fprintf(stderr, "recv(server) failed: %s\n",
+ strerror(errno));
+ exit(1);
+ }
+ }
+
+ /* read from client */
+ if (pfd[1].revents & POLLIN) {
+ if ((rs = recv(sock, buffer, sizeof(buffer), 0)) > 0) {
+ libtelnet_push(&telnet, buffer, rs);
+ } else if (rs == 0) {
+ break;
+ } else {
+ fprintf(stderr, "recv(client) failed: %s\n",
+ strerror(errno));
+ exit(1);
+ }
+ }
+ }
+
+ /* clean up */
+ libtelnet_free(&telnet);
+ close(sock);
+
+ return 0;
+}