rsh.c

   1 #include "rsh.h"
   2
   3 #include <string.h>
   4 #include <sys/types.h>
   5 #include <sys/socket.h>
   6
   7 #include "cache.h"
   8
   9 #define COMMAND_SIZE 4096
  10
  11 int setup_connection(int *fd_in, int *fd_out, char *remote_prog,
  12                      char *url, int rmt_argc, char **rmt_argv)
  13 {
  14         char *host;
  15         char *path;
  16         int sv[2];
  17         char command[COMMAND_SIZE];
  18         char *posn;
  19         int i;
  20
  21         if (!strcmp(url, "-")) {
  22                 *fd_in = 0;
  23                 *fd_out = 1;
  24                 return 0;
  25         }
  26
  27         host = strstr(url, "//");
  28         if (!host) {
  29                 return error("Bad URL: %s", url);
  30         }
  31         host += 2;
  32         path = strchr(host, '/');
  33         if (!path) {
  34                 return error("Bad URL: %s", url);
  35         }
  36         *(path++) = '\0';
  37         /* ssh <host> 'cd /<path>; stdio-pull <arg...> <commit-id>' */
  38         snprintf(command, COMMAND_SIZE,
  39                  "cd /%s; %s=objects %s",
  40                  path, DB_ENVIRONMENT, remote_prog);
  41         posn = command + strlen(command);
  42         for (i = 0; i < rmt_argc; i++) {
  43                 *(posn++) = ' ';
  44                 strncpy(posn, rmt_argv[i], COMMAND_SIZE - (posn - command));
  45                 posn += strlen(rmt_argv[i]);
  46                 if (posn - command + 4 >= COMMAND_SIZE) {
  47                         return error("Command line too long");
  48                 }
  49         }
  50         strcpy(posn, " -");
  51         if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv)) {
  52                 return error("Couldn't create socket");
  53         }
  54         if (!fork()) {
  55                 close(sv[1]);
  56                 dup2(sv[0], 0);
  57                 dup2(sv[0], 1);
  58                 execlp("ssh", "ssh", host, command, NULL);
  59         }
  60         close(sv[0]);
  61         *fd_in = sv[1];
  62         *fd_out = sv[1];
  63         return 0;
  64 }