Sean Middleditch | b9ab0b6 | 2009-03-14 00:18:44 -0400 | [diff] [blame] | 1 | #include <sys/socket.h> |
| 2 | #include <netinet/in.h> |
| 3 | #include <arpa/inet.h> |
| 4 | #include <poll.h> |
| 5 | #include <errno.h> |
| 6 | #include <stdio.h> |
| 7 | #include <string.h> |
| 8 | #include <stdlib.h> |
| 9 | #include <ctype.h> |
| 10 | #include <unistd.h> |
| 11 | |
| 12 | #include "libtelnet.h" |
| 13 | |
| 14 | static int server_sock; |
| 15 | static int client_sock; |
| 16 | |
| 17 | static struct libtelnet_t server_telnet; |
| 18 | static struct libtelnet_t client_telnet; |
| 19 | |
| 20 | static const char* get_name(int sock) { |
| 21 | if (sock == server_sock) |
| 22 | return "\e[31mSERVER"; |
| 23 | else |
| 24 | return "\e[34mCLIENT"; |
| 25 | } |
| 26 | |
| 27 | static struct libtelnet_t *other_telnet(struct libtelnet_t *telnet) { |
| 28 | if (telnet == &server_telnet) |
| 29 | return &client_telnet; |
| 30 | else |
| 31 | return &server_telnet; |
| 32 | } |
| 33 | |
| 34 | static void* other_socket(int sock) { |
| 35 | if (sock == server_sock) |
| 36 | return (void*)&client_sock; |
| 37 | else |
| 38 | return (void*)&server_sock; |
| 39 | } |
| 40 | |
| 41 | static void print_buffer(unsigned char *buffer, unsigned int size) { |
| 42 | unsigned int i; |
| 43 | for (i = 0; i != size; ++i) { |
| 44 | if (buffer[i] == ' ' || (isprint(buffer[i]) && !isspace(buffer[i]))) |
| 45 | printf("%c", (char)buffer[i]); |
| 46 | else if (buffer[i] == '\n') |
| 47 | printf("<%02X>\n", (int)buffer[i]); |
| 48 | else |
| 49 | printf("<%02X>", (int)buffer[i]); |
| 50 | } |
| 51 | } |
| 52 | |
Sean Middleditch | 78f400f | 2009-03-14 01:26:43 -0400 | [diff] [blame^] | 53 | void libtelnet_data_cb(struct libtelnet_t *telnet, unsigned char *buffer, |
Sean Middleditch | b9ab0b6 | 2009-03-14 00:18:44 -0400 | [diff] [blame] | 54 | unsigned int size, void *user_data) { |
| 55 | int sock = *(int*)user_data; |
| 56 | |
Sean Middleditch | 78f400f | 2009-03-14 01:26:43 -0400 | [diff] [blame^] | 57 | printf("%s DATA: ", get_name(sock)); |
Sean Middleditch | b9ab0b6 | 2009-03-14 00:18:44 -0400 | [diff] [blame] | 58 | print_buffer(buffer, size); |
| 59 | printf("\e[0m\n"); |
| 60 | |
| 61 | libtelnet_send_data(other_telnet(telnet), buffer, size, |
| 62 | other_socket(sock)); |
| 63 | } |
| 64 | |
Sean Middleditch | 78f400f | 2009-03-14 01:26:43 -0400 | [diff] [blame^] | 65 | void libtelnet_send_cb(struct libtelnet_t *telnet, unsigned char *buffer, |
Sean Middleditch | b9ab0b6 | 2009-03-14 00:18:44 -0400 | [diff] [blame] | 66 | unsigned int size, void *user_data) { |
| 67 | int sock = *(int*)user_data; |
| 68 | |
| 69 | /* DONT SPAM |
Sean Middleditch | 78f400f | 2009-03-14 01:26:43 -0400 | [diff] [blame^] | 70 | printf("%s SEND: ", get_name(sock)); |
Sean Middleditch | b9ab0b6 | 2009-03-14 00:18:44 -0400 | [diff] [blame] | 71 | print_buffer(buffer, size); |
| 72 | printf("\e[0m\n"); |
| 73 | */ |
| 74 | |
| 75 | /* send data */ |
| 76 | send(sock, buffer, size, 0); |
| 77 | } |
| 78 | |
| 79 | void libtelnet_command_cb(struct libtelnet_t *telnet, unsigned char cmd, |
| 80 | void *user_data) { |
| 81 | int sock = *(int*)user_data; |
| 82 | |
| 83 | printf("%s IAC %d\e[0m\n", get_name(sock), (int)cmd); |
| 84 | |
| 85 | libtelnet_send_command(other_telnet(telnet), cmd, other_socket(sock)); |
| 86 | } |
| 87 | |
| 88 | void libtelnet_negotiate_cb(struct libtelnet_t *telnet, unsigned char cmd, |
| 89 | unsigned char opt, void *user_data) { |
| 90 | int sock = *(int*)user_data; |
| 91 | |
| 92 | printf("%s IAC %d %d\e[0m\n", get_name(sock), (int)cmd, (int)opt); |
| 93 | |
| 94 | libtelnet_send_negotiate(other_telnet(telnet), cmd, opt, |
| 95 | other_socket(sock)); |
| 96 | } |
| 97 | |
| 98 | void libtelnet_subrequest_cb(struct libtelnet_t *telnet, unsigned char type, |
| 99 | unsigned char *buffer, unsigned int size, void *user_data) { |
| 100 | int sock = *(int*)user_data; |
| 101 | |
| 102 | printf("%s SUBREQ %d: ", get_name(sock), (int)type); |
| 103 | print_buffer(buffer, size); |
| 104 | printf("\e[0m\n"); |
| 105 | |
| 106 | libtelnet_send_subrequest(other_telnet(telnet), type, buffer, size, |
| 107 | other_socket(sock)); |
| 108 | } |
| 109 | |
| 110 | void libtelnet_error_cb(struct libtelnet_t *telnet, |
| 111 | enum libtelnet_error_t error, void *user_data) { |
| 112 | int sock = *(int*)user_data; |
| 113 | |
| 114 | printf("%s ERROR: %d\e[0m\n", get_name(sock), (int)error); |
| 115 | } |
| 116 | |
| 117 | int main(int argc, char **argv) { |
| 118 | unsigned char buffer[512]; |
| 119 | int listen_sock; |
| 120 | int rs; |
| 121 | struct sockaddr_in addr; |
| 122 | socklen_t addrlen; |
| 123 | struct pollfd pfd[2]; |
| 124 | |
| 125 | /* check usage */ |
| 126 | if (argc != 4) { |
| 127 | fprintf(stderr, "Usage:\n ./telnet-proxy <remote ip> <remote port> <local port>\n"); |
| 128 | return 1; |
| 129 | } |
| 130 | |
| 131 | /* create listening socket */ |
| 132 | if ((listen_sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) { |
| 133 | fprintf(stderr, "socket() failed: %s\n", strerror(errno)); |
| 134 | return 1; |
| 135 | } |
| 136 | |
| 137 | /* re-use addr */ |
| 138 | rs = 1; |
| 139 | setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, &rs, sizeof(rs)); |
| 140 | |
| 141 | /* bind */ |
| 142 | memset(&addr, 0, sizeof(addr)); |
| 143 | addr.sin_family = AF_INET; |
| 144 | addr.sin_addr.s_addr = INADDR_ANY; |
| 145 | addr.sin_port = htons(strtol(argv[3], 0, 10)); |
| 146 | if (bind(listen_sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) { |
| 147 | fprintf(stderr, "bind() failed: %s\n", strerror(errno)); |
| 148 | return 1; |
| 149 | } |
| 150 | |
| 151 | /* listen */ |
| 152 | if (listen(listen_sock, 5) == -1) { |
| 153 | fprintf(stderr, "listen() failed: %s\n", strerror(errno)); |
| 154 | return 1; |
| 155 | } |
| 156 | |
| 157 | /* wait for client connection */ |
| 158 | if ((client_sock = accept(listen_sock, (struct sockaddr *)&addr, &addrlen)) == -1) { |
| 159 | fprintf(stderr, "accept() failed: %s\n", strerror(errno)); |
| 160 | return 1; |
| 161 | } |
| 162 | |
| 163 | /* create server socket */ |
| 164 | if ((server_sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) { |
| 165 | fprintf(stderr, "socket() failed: %s\n", strerror(errno)); |
| 166 | return 1; |
| 167 | } |
| 168 | |
| 169 | /* bind */ |
| 170 | memset(&addr, 0, sizeof(addr)); |
| 171 | addr.sin_family = AF_INET; |
| 172 | if (bind(server_sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) { |
| 173 | fprintf(stderr, "bind() failed: %s\n", strerror(errno)); |
| 174 | return 1; |
| 175 | } |
| 176 | |
| 177 | /* connect */ |
| 178 | memset(&addr, 0, sizeof(addr)); |
| 179 | if (inet_pton(AF_INET, argv[1], &addr.sin_addr) != 1) { |
| 180 | fprintf(stderr, "inet_pton() failed: %s\n", strerror(errno)); |
| 181 | return 1; |
| 182 | } |
| 183 | addr.sin_family = AF_INET; |
| 184 | addr.sin_port = htons(strtol(argv[2], 0, 10)); |
| 185 | if (connect(server_sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) { |
| 186 | fprintf(stderr, "server() failed: %s\n", strerror(errno)); |
| 187 | return 1; |
| 188 | } |
| 189 | |
| 190 | /* initialize telnet boxes */ |
| 191 | libtelnet_init(&server_telnet); |
| 192 | libtelnet_init(&client_telnet); |
| 193 | |
| 194 | /* initialize poll descriptors */ |
| 195 | memset(pfd, 0, sizeof(pfd)); |
| 196 | pfd[0].fd = server_sock; |
| 197 | pfd[0].events = POLLIN | POLLHUP; |
| 198 | pfd[1].fd = client_sock; |
| 199 | pfd[1].events = POLLIN | POLLHUP; |
| 200 | |
| 201 | /* loop while both connections are open */ |
| 202 | while (poll(pfd, 2, -1) != -1) { |
| 203 | /* read from server */ |
| 204 | if (pfd[0].revents & POLLIN) { |
| 205 | if ((rs = recv(pfd[0].fd, buffer, sizeof(buffer), 0)) > 0) |
| 206 | libtelnet_push(&server_telnet, buffer, rs, (void*)&pfd[0].fd); |
| 207 | } |
| 208 | if (pfd[0].revents & POLLHUP) |
| 209 | break; |
| 210 | |
| 211 | /* read from client */ |
| 212 | if (pfd[1].revents & POLLIN) { |
| 213 | if ((rs = recv(pfd[1].fd, buffer, sizeof(buffer), 0)) > 0) |
| 214 | libtelnet_push(&client_telnet, buffer, rs, (void*)&pfd[1].fd); |
| 215 | } |
| 216 | if (pfd[1].revents & POLLHUP) |
| 217 | break; |
| 218 | } |
| 219 | |
| 220 | /* clean up */ |
| 221 | libtelnet_free(&server_telnet); |
| 222 | libtelnet_free(&client_telnet); |
| 223 | close(server_sock); |
| 224 | close(client_sock); |
| 225 | close(listen_sock); |
| 226 | |
| 227 | return 0; |
| 228 | } |