rsh.c

   1 #include <string.h>
   2 #include <sys/types.h>
   3 #include <sys/socket.h>
   4
   5 #include "rsh.h"
   6 #include "quote.h"
   7 #include "cache.h"
   8
   9 #define COMMAND_SIZE 4096
  10
  11 int setup_connection(int *fd_in, int *fd_out, const 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 sizen;
  20         int of;
  21         int i;
  22         pid_t pid;
  23
  24         if (!strcmp(url, "-")) {
  25                 *fd_in = 0;
  26                 *fd_out = 1;
  27                 return 0;
  28         }
  29
  30         host = strstr(url, "//");
  31         if (host) {
  32                 host += 2;
  33                 path = strchr(host, '/');
  34         } else {
  35                 host = url;
  36                 path = strchr(host, ':');
  37                 if (path)
  38                         *(path++) = '\0';
  39         }
  40         if (!path) {
  41                 return error("Bad URL: %s", url);
  42         }
  43         /* $GIT_RSH <host> "env GIT_DIR=<path> <remote_prog> <args...>" */
  44         sizen = COMMAND_SIZE;
  45         posn = command;
  46         of = 0;
  47         of |= add_to_string(&posn, &sizen, "env ", 0);
  48         of |= add_to_string(&posn, &sizen, GIT_DIR_ENVIRONMENT "=", 0);
  49         of |= add_to_string(&posn, &sizen, path, 1);
  50         of |= add_to_string(&posn, &sizen, " ", 0);
  51         of |= add_to_string(&posn, &sizen, remote_prog, 1);
  52
  53         for ( i = 0 ; i < rmt_argc ; i++ ) {
  54                 of |= add_to_string(&posn, &sizen, " ", 0);
  55                 of |= add_to_string(&posn, &sizen, rmt_argv[i], 1);
  56         }
  57
  58         of |= add_to_string(&posn, &sizen, " -", 0);
  59
  60         if ( of )
  61                 return error("Command line too long");
  62
  63         if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
  64                 return error("Couldn't create socket");
  65
  66         pid = fork();
  67         if (pid < 0)
  68                 return error("Couldn't fork");
  69         if (!pid) {
  70                 const char *ssh, *ssh_basename;
  71                 ssh = getenv("GIT_SSH");
  72                 if (!ssh) ssh = "ssh";
  73                 ssh_basename = strrchr(ssh, '/');
  74                 if (!ssh_basename)
  75                         ssh_basename = ssh;
  76                 else
  77                         ssh_basename++;
  78                 close(sv[1]);
  79                 dup2(sv[0], 0);
  80                 dup2(sv[0], 1);
  81                 execlp(ssh, ssh_basename, host, command, NULL);
  82         }
  83         close(sv[0]);
  84         *fd_in = sv[1];
  85         *fd_out = sv[1];
  86         return 0;
  87 }