2009-03-14 06:20:03 +00:00
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/*
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* Sean Middleditch
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* sean@sourcemud.org
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*
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* The author or authors of this code dedicate any and all copyright interest
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* in this code to the public domain. We make this dedication for the benefit
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* of the public at large and to the detriment of our heirs and successors. We
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* intend this dedication to be an overt act of relinquishment in perpetuity of
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* all present and future rights to this code under copyright law.
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*/
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2009-03-14 04:18:44 +00:00
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <poll.h>
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#include <errno.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <ctype.h>
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#include <unistd.h>
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2009-03-14 07:35:49 +00:00
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#ifdef HAVE_ZLIB
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#include "zlib.h"
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#endif
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2009-03-14 04:18:44 +00:00
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#include "libtelnet.h"
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2009-03-14 06:04:28 +00:00
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struct conn_t {
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const char *name;
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int sock;
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struct libtelnet_t telnet;
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struct conn_t *remote;
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};
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2009-03-14 04:18:44 +00:00
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2009-03-14 05:57:07 +00:00
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static const char *get_cmd(unsigned char cmd) {
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static char buffer[4];
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switch (cmd) {
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case 255: return "IAC";
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case 254: return "DONT";
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case 253: return "DO";
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case 252: return "WONT";
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case 251: return "WILL";
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case 250: return "SB";
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case 249: return "GA";
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case 248: return "EL";
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case 247: return "EC";
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case 246: return "AYT";
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case 245: return "AO";
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case 244: return "IP";
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case 243: return "BREAK";
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case 242: return "DM";
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case 241: return "NOP";
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case 240: return "SE";
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case 239: return "EOR";
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case 238: return "ABORT";
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case 237: return "SUSP";
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case 236: return "xEOF";
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default:
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snprintf(buffer, sizeof(buffer), "%d", (int)cmd);
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return buffer;
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}
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}
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static const char *get_opt(unsigned char opt) {
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switch (opt) {
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case 0: return "BINARY";
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case 1: return "ECHO";
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case 2: return "RCP";
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case 3: return "SGA";
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case 4: return "NAMS";
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case 5: return "STATUS";
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case 6: return "TM";
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case 7: return "RCTE";
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case 8: return "NAOL";
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case 9: return "NAOP";
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case 10: return "NAOCRD";
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case 11: return "NAOHTS";
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case 12: return "NAOHTD";
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case 13: return "NAOFFD";
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case 14: return "NAOVTS";
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case 15: return "NAOVTD";
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case 16: return "NAOLFD";
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case 17: return "XASCII";
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case 18: return "LOGOUT";
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case 19: return "BM";
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case 20: return "DET";
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case 21: return "SUPDUP";
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case 22: return "SUPDUPOUTPUT";
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case 23: return "SNDLOC";
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case 24: return "TTYPE";
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case 25: return "EOR";
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case 26: return "TUID";
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case 27: return "OUTMRK";
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case 28: return "TTYLOC";
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case 29: return "3270REGIME";
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case 30: return "X3PAD";
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case 31: return "NAWS";
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case 32: return "TSPEED";
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case 33: return "LFLOW";
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case 34: return "LINEMODE";
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case 35: return "XDISPLOC";
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case 36: return "ENVIRON";
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case 37: return "AUTHENTICATION";
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case 38: return "ENCRYPT";
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case 39: return "NEW-ENVIRON";
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case 70: return "MSSP";
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case 85: return "COMPRESS";
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case 86: return "COMPRESS2";
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case 93: return "ZMP";
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case 255: return "EXOPL";
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default: return "unknown";
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}
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}
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2009-03-14 04:18:44 +00:00
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static void print_buffer(unsigned char *buffer, unsigned int size) {
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unsigned int i;
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for (i = 0; i != size; ++i) {
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if (buffer[i] == ' ' || (isprint(buffer[i]) && !isspace(buffer[i])))
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printf("%c", (char)buffer[i]);
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else if (buffer[i] == '\n')
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printf("<%02X>\n", (int)buffer[i]);
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else
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printf("<%02X>", (int)buffer[i]);
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}
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}
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2009-03-14 05:26:43 +00:00
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void libtelnet_data_cb(struct libtelnet_t *telnet, unsigned char *buffer,
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2009-03-14 04:18:44 +00:00
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unsigned int size, void *user_data) {
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2009-03-14 06:04:28 +00:00
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struct conn_t *conn = (struct conn_t*)user_data;
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2009-03-14 04:18:44 +00:00
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2009-03-14 06:04:28 +00:00
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printf("%s DATA: ", conn->name);
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2009-03-14 04:18:44 +00:00
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print_buffer(buffer, size);
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printf("\e[0m\n");
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2009-03-14 06:04:28 +00:00
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libtelnet_send_data(&conn->remote->telnet, buffer, size,
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conn->remote);
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2009-03-14 04:18:44 +00:00
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}
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2009-03-14 05:26:43 +00:00
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void libtelnet_send_cb(struct libtelnet_t *telnet, unsigned char *buffer,
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2009-03-14 04:18:44 +00:00
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unsigned int size, void *user_data) {
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2009-03-14 06:04:28 +00:00
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struct conn_t *conn = (struct conn_t*)user_data;
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2009-03-14 06:13:50 +00:00
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int rs;
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2009-03-14 04:18:44 +00:00
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/* DONT SPAM
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2009-03-14 06:04:28 +00:00
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printf("%s SEND: ", conn->name);
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2009-03-14 04:18:44 +00:00
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print_buffer(buffer, size);
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printf("\e[0m\n");
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*/
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/* send data */
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2009-03-14 06:13:50 +00:00
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while (size > 0) {
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if ((rs = send(conn->sock, buffer, size, 0)) == -1) {
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fprintf(stderr, "send() failed: %s\n", strerror(errno));
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exit(1);
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} else if (rs == 0) {
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fprintf(stderr, "send() unexpectedly returned 0\n");
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exit(1);
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}
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/* update pointer and size to see if we've got more to send */
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buffer += rs;
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size -= rs;
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}
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2009-03-14 04:18:44 +00:00
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}
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void libtelnet_command_cb(struct libtelnet_t *telnet, unsigned char cmd,
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void *user_data) {
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2009-03-14 06:04:28 +00:00
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struct conn_t *conn = (struct conn_t*)user_data;
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2009-03-14 04:18:44 +00:00
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2009-03-14 06:04:28 +00:00
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printf("%s IAC %s\e[0m\n", conn->name, get_cmd(cmd));
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2009-03-14 04:18:44 +00:00
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2009-03-14 06:04:28 +00:00
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libtelnet_send_command(&conn->remote->telnet, cmd, conn->remote);
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2009-03-14 04:18:44 +00:00
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}
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void libtelnet_negotiate_cb(struct libtelnet_t *telnet, unsigned char cmd,
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unsigned char opt, void *user_data) {
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2009-03-14 06:04:28 +00:00
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struct conn_t *conn = (struct conn_t*)user_data;
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2009-03-14 04:18:44 +00:00
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2009-03-14 06:04:28 +00:00
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printf("%s IAC %s %d (%s)\e[0m\n", conn->name, get_cmd(cmd),
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2009-03-14 05:57:07 +00:00
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(int)opt, get_opt(opt));
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2009-03-14 04:18:44 +00:00
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2009-03-14 07:35:49 +00:00
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/* FIXME: HACK: allow MCCP2 from server without passing it
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* through to client. this is temporary until libtelnet supports
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* the server-end of MCCP2.
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*/
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if (cmd == LIBTELNET_WILL && opt == LIBTELNET_OPTION_COMPRESS2) {
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libtelnet_send_negotiate(&conn->telnet, LIBTELNET_DO, opt, conn);
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return;
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}
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2009-03-14 06:04:28 +00:00
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libtelnet_send_negotiate(&conn->remote->telnet, cmd, opt,
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conn->remote);
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2009-03-14 04:18:44 +00:00
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}
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void libtelnet_subrequest_cb(struct libtelnet_t *telnet, unsigned char type,
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unsigned char *buffer, unsigned int size, void *user_data) {
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2009-03-14 06:04:28 +00:00
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struct conn_t *conn = (struct conn_t*)user_data;
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2009-03-14 04:18:44 +00:00
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2009-03-14 06:04:28 +00:00
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printf("%s SUB %d (%s)", conn->name, (int)type, get_opt(type));
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2009-03-14 05:57:07 +00:00
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if (size > 0) {
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printf(": ");
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print_buffer(buffer, size);
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}
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2009-03-14 04:18:44 +00:00
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printf("\e[0m\n");
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2009-03-14 06:04:28 +00:00
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libtelnet_send_subrequest(&conn->remote->telnet, type, buffer, size,
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conn->remote);
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2009-03-14 04:18:44 +00:00
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}
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void libtelnet_error_cb(struct libtelnet_t *telnet,
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enum libtelnet_error_t error, void *user_data) {
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2009-03-14 06:04:28 +00:00
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struct conn_t *conn = (struct conn_t*)user_data;
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2009-03-14 04:18:44 +00:00
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2009-03-14 06:04:28 +00:00
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printf("%s ERROR: %d\e[0m\n", conn->name, (int)error);
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2009-03-14 07:35:49 +00:00
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exit(1);
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2009-03-14 04:18:44 +00:00
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}
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int main(int argc, char **argv) {
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unsigned char buffer[512];
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int listen_sock;
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int rs;
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struct sockaddr_in addr;
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socklen_t addrlen;
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struct pollfd pfd[2];
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2009-03-14 06:04:28 +00:00
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struct conn_t server;
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struct conn_t client;
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2009-03-14 04:18:44 +00:00
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/* check usage */
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if (argc != 4) {
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2009-03-14 06:04:28 +00:00
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fprintf(stderr, "Usage:\n ./telnet-proxy <remote ip> <remote port> "
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"<local port>\n");
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2009-03-14 04:18:44 +00:00
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return 1;
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}
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/* create listening socket */
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if ((listen_sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
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fprintf(stderr, "socket() failed: %s\n", strerror(errno));
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return 1;
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}
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2009-03-14 06:13:50 +00:00
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/* reuse address option */
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2009-03-14 04:18:44 +00:00
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rs = 1;
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setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, &rs, sizeof(rs));
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2009-03-14 06:13:50 +00:00
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/* bind to listening addr/port */
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2009-03-14 04:18:44 +00:00
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memset(&addr, 0, sizeof(addr));
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addr.sin_family = AF_INET;
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addr.sin_addr.s_addr = INADDR_ANY;
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addr.sin_port = htons(strtol(argv[3], 0, 10));
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if (bind(listen_sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
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fprintf(stderr, "bind() failed: %s\n", strerror(errno));
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return 1;
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}
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2009-03-14 06:13:50 +00:00
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/* wait for client */
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2009-03-14 04:18:44 +00:00
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if (listen(listen_sock, 5) == -1) {
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fprintf(stderr, "listen() failed: %s\n", strerror(errno));
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return 1;
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}
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2009-03-14 07:35:49 +00:00
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addrlen = sizeof(addr);
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2009-03-14 06:04:28 +00:00
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if ((client.sock = accept(listen_sock, (struct sockaddr *)&addr, &addrlen)) == -1) {
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2009-03-14 04:18:44 +00:00
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fprintf(stderr, "accept() failed: %s\n", strerror(errno));
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return 1;
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}
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/* create server socket */
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2009-03-14 06:04:28 +00:00
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if ((server.sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
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2009-03-14 04:18:44 +00:00
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fprintf(stderr, "socket() failed: %s\n", strerror(errno));
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return 1;
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}
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2009-03-14 06:13:50 +00:00
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/* connect to server */
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2009-03-14 04:18:44 +00:00
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memset(&addr, 0, sizeof(addr));
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addr.sin_family = AF_INET;
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2009-03-14 06:04:28 +00:00
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if (bind(server.sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
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2009-03-14 04:18:44 +00:00
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fprintf(stderr, "bind() failed: %s\n", strerror(errno));
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return 1;
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}
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memset(&addr, 0, sizeof(addr));
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if (inet_pton(AF_INET, argv[1], &addr.sin_addr) != 1) {
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fprintf(stderr, "inet_pton() failed: %s\n", strerror(errno));
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return 1;
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}
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addr.sin_family = AF_INET;
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addr.sin_port = htons(strtol(argv[2], 0, 10));
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2009-03-14 06:04:28 +00:00
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if (connect(server.sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
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2009-03-14 04:18:44 +00:00
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fprintf(stderr, "server() failed: %s\n", strerror(errno));
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return 1;
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}
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2009-03-14 06:04:28 +00:00
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/* initialize connection structs */
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server.name = "\e[31mSERVER";
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server.remote = &client;
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client.name = "\e[34mCLIENT";
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client.remote = &server;
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2009-03-14 04:18:44 +00:00
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/* initialize telnet boxes */
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2009-03-14 06:04:28 +00:00
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libtelnet_init(&server.telnet);
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libtelnet_init(&client.telnet);
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2009-03-14 04:18:44 +00:00
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/* initialize poll descriptors */
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memset(pfd, 0, sizeof(pfd));
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2009-03-14 06:04:28 +00:00
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pfd[0].fd = server.sock;
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2009-03-14 06:13:50 +00:00
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pfd[0].events = POLLIN;
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2009-03-14 06:04:28 +00:00
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pfd[1].fd = client.sock;
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2009-03-14 06:13:50 +00:00
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pfd[1].events = POLLIN;
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2009-03-14 04:18:44 +00:00
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/* loop while both connections are open */
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while (poll(pfd, 2, -1) != -1) {
|
|
|
|
/* read from server */
|
|
|
|
if (pfd[0].revents & POLLIN) {
|
2009-03-14 06:13:50 +00:00
|
|
|
if ((rs = recv(server.sock, buffer, sizeof(buffer), 0)) > 0) {
|
2009-03-14 06:04:28 +00:00
|
|
|
libtelnet_push(&server.telnet, buffer, rs, (void*)&server);
|
2009-03-14 06:13:50 +00:00
|
|
|
} else if (rs == 0) {
|
|
|
|
printf("%s DISCONNECTED\e[0m\n", server.name);
|
|
|
|
break;
|
|
|
|
} else {
|
|
|
|
fprintf(stderr, "recv(server) failed: %s\n", strerror(errno));
|
|
|
|
exit(1);
|
|
|
|
}
|
2009-03-14 04:18:44 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/* read from client */
|
|
|
|
if (pfd[1].revents & POLLIN) {
|
2009-03-14 06:13:50 +00:00
|
|
|
if ((rs = recv(client.sock, buffer, sizeof(buffer), 0)) > 0) {
|
2009-03-14 06:04:28 +00:00
|
|
|
libtelnet_push(&client.telnet, buffer, rs, (void*)&client);
|
2009-03-14 06:13:50 +00:00
|
|
|
} else if (rs == 0) {
|
|
|
|
printf("%s DISCONNECTED\e[0m\n", client.name);
|
|
|
|
break;
|
|
|
|
} else {
|
|
|
|
fprintf(stderr, "recv(client) failed: %s\n", strerror(errno));
|
|
|
|
exit(1);
|
|
|
|
}
|
2009-03-14 04:18:44 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* clean up */
|
2009-03-14 06:04:28 +00:00
|
|
|
libtelnet_free(&server.telnet);
|
|
|
|
libtelnet_free(&client.telnet);
|
|
|
|
close(server.sock);
|
|
|
|
close(client.sock);
|
2009-03-14 04:18:44 +00:00
|
|
|
close(listen_sock);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|