| 1 | #define _XOPEN_SOURCE |
| 2 | #define _XOPEN_SOURCE_EXTENDED |
| 3 | #include <features.h> |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <stdlib.h> |
| 7 | #include <string.h> |
| 8 | #include <unistd.h> |
| 9 | #include <signal.h> |
| 10 | #include <fcntl.h> |
| 11 | #include <termios.h> |
| 12 | #include <sys/types.h> |
| 13 | #include <sys/wait.h> |
| 14 | #include <sys/ioctl.h> |
| 15 | |
| 16 | #include "putty.h" |
| 17 | |
| 18 | #ifndef FALSE |
| 19 | #define FALSE 0 |
| 20 | #endif |
| 21 | #ifndef TRUE |
| 22 | #define TRUE 1 |
| 23 | #endif |
| 24 | |
| 25 | int pty_master_fd; |
| 26 | static int pty_child_pid; |
| 27 | static sig_atomic_t pty_child_dead; |
| 28 | char **pty_argv; |
| 29 | |
| 30 | int pty_child_is_dead(void) |
| 31 | { |
| 32 | return pty_child_dead; |
| 33 | } |
| 34 | |
| 35 | static void pty_size(void); |
| 36 | |
| 37 | static void sigchld_handler(int signum) |
| 38 | { |
| 39 | pid_t pid; |
| 40 | int status; |
| 41 | pid = waitpid(-1, &status, WNOHANG); |
| 42 | if (pid == pty_child_pid && (WIFEXITED(status) || WIFSIGNALED(status))) |
| 43 | pty_child_dead = TRUE; |
| 44 | } |
| 45 | |
| 46 | /* |
| 47 | * Called to set up the pty. |
| 48 | * |
| 49 | * Returns an error message, or NULL on success. |
| 50 | * |
| 51 | * Also places the canonical host name into `realhost'. It must be |
| 52 | * freed by the caller. |
| 53 | */ |
| 54 | static char *pty_init(char *host, int port, char **realhost, int nodelay) |
| 55 | { |
| 56 | int slavefd; |
| 57 | char name[FILENAME_MAX]; |
| 58 | pid_t pid, pgrp; |
| 59 | |
| 60 | pty_master_fd = open("/dev/ptmx", O_RDWR); |
| 61 | |
| 62 | if (pty_master_fd < 0) { |
| 63 | perror("/dev/ptmx: open"); |
| 64 | exit(1); |
| 65 | } |
| 66 | |
| 67 | if (grantpt(pty_master_fd) < 0) { |
| 68 | perror("grantpt"); |
| 69 | exit(1); |
| 70 | } |
| 71 | |
| 72 | if (unlockpt(pty_master_fd) < 0) { |
| 73 | perror("unlockpt"); |
| 74 | exit(1); |
| 75 | } |
| 76 | |
| 77 | name[FILENAME_MAX-1] = '\0'; |
| 78 | strncpy(name, ptsname(pty_master_fd), FILENAME_MAX-1); |
| 79 | |
| 80 | /* |
| 81 | * Fork and execute the command. |
| 82 | */ |
| 83 | pid = fork(); |
| 84 | if (pid < 0) { |
| 85 | perror("fork"); |
| 86 | exit(1); |
| 87 | } |
| 88 | |
| 89 | if (pid == 0) { |
| 90 | int i; |
| 91 | /* |
| 92 | * We are the child. |
| 93 | */ |
| 94 | |
| 95 | slavefd = open(name, O_RDWR); |
| 96 | if (slavefd < 0) { |
| 97 | perror("slave pty: open"); |
| 98 | exit(1); |
| 99 | } |
| 100 | |
| 101 | close(pty_master_fd); |
| 102 | close(0); |
| 103 | close(1); |
| 104 | close(2); |
| 105 | fcntl(slavefd, F_SETFD, 0); /* don't close on exec */ |
| 106 | dup2(slavefd, 0); |
| 107 | dup2(slavefd, 1); |
| 108 | dup2(slavefd, 2); |
| 109 | setsid(); |
| 110 | ioctl(slavefd, TIOCSCTTY, 1); |
| 111 | pgrp = getpid(); |
| 112 | tcsetpgrp(slavefd, pgrp); |
| 113 | setpgrp(); |
| 114 | close(open(name, O_WRONLY, 0)); |
| 115 | setpgrp(); |
| 116 | /* Close everything _else_, for tidiness. */ |
| 117 | for (i = 3; i < 1024; i++) |
| 118 | close(i); |
| 119 | { |
| 120 | char term_env_var[10 + sizeof(cfg.termtype)]; |
| 121 | sprintf(term_env_var, "TERM=%s", cfg.termtype); |
| 122 | putenv(term_env_var); |
| 123 | } |
| 124 | if (pty_argv) |
| 125 | execvp(pty_argv[0], pty_argv); |
| 126 | else |
| 127 | execl(getenv("SHELL"), getenv("SHELL"), NULL); |
| 128 | /* |
| 129 | * If we're here, exec has gone badly foom. |
| 130 | */ |
| 131 | perror("exec"); |
| 132 | exit(127); |
| 133 | } else { |
| 134 | close(slavefd); |
| 135 | pty_child_pid = pid; |
| 136 | pty_child_dead = FALSE; |
| 137 | signal(SIGCHLD, sigchld_handler); |
| 138 | } |
| 139 | |
| 140 | return NULL; |
| 141 | } |
| 142 | |
| 143 | /* |
| 144 | * Called to send data down the pty. |
| 145 | */ |
| 146 | static int pty_send(char *buf, int len) |
| 147 | { |
| 148 | while (len > 0) { |
| 149 | int ret = write(pty_master_fd, buf, len); |
| 150 | if (ret < 0) { |
| 151 | perror("write pty master"); |
| 152 | exit(1); |
| 153 | } |
| 154 | buf += ret; |
| 155 | len -= ret; |
| 156 | } |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | /* |
| 161 | * Called to query the current socket sendability status. |
| 162 | */ |
| 163 | static int pty_sendbuffer(void) |
| 164 | { |
| 165 | return 0; |
| 166 | } |
| 167 | |
| 168 | /* |
| 169 | * Called to set the size of the window |
| 170 | */ |
| 171 | static void pty_size(void) |
| 172 | { |
| 173 | struct winsize size; |
| 174 | |
| 175 | size.ws_row = (unsigned short)rows; |
| 176 | size.ws_col = (unsigned short)cols; |
| 177 | ioctl(pty_master_fd, TIOCSWINSZ, (void *)&size); |
| 178 | return; |
| 179 | } |
| 180 | |
| 181 | /* |
| 182 | * Send special codes. |
| 183 | */ |
| 184 | static void pty_special(Telnet_Special code) |
| 185 | { |
| 186 | /* Do nothing! */ |
| 187 | return; |
| 188 | } |
| 189 | |
| 190 | static Socket pty_socket(void) |
| 191 | { |
| 192 | return NULL; /* shouldn't ever be needed */ |
| 193 | } |
| 194 | |
| 195 | static int pty_sendok(void) |
| 196 | { |
| 197 | return 1; |
| 198 | } |
| 199 | |
| 200 | static void pty_unthrottle(int backlog) |
| 201 | { |
| 202 | /* do nothing */ |
| 203 | } |
| 204 | |
| 205 | static int pty_ldisc(int option) |
| 206 | { |
| 207 | return 0; /* neither editing nor echoing */ |
| 208 | } |
| 209 | |
| 210 | static int pty_exitcode(void) |
| 211 | { |
| 212 | /* Shouldn't ever be required */ |
| 213 | return 0; |
| 214 | } |
| 215 | |
| 216 | Backend pty_backend = { |
| 217 | pty_init, |
| 218 | pty_send, |
| 219 | pty_sendbuffer, |
| 220 | pty_size, |
| 221 | pty_special, |
| 222 | pty_socket, |
| 223 | pty_exitcode, |
| 224 | pty_sendok, |
| 225 | pty_ldisc, |
| 226 | pty_unthrottle, |
| 227 | 1 |
| 228 | }; |