mdw@git.distorted.org.uk Git - sgt/putty/blob - unix/pty.c

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