git/rsh.c

   1 #include "cache.h"
   2 #include "rsh.h"
   3 #include "quote.h"
   4
   5 #define COMMAND_SIZE 4096
   6
   7 int setup_connection(int *fd_in, int *fd_out, const char *remote_prog,
   8                      char *url, int rmt_argc, char **rmt_argv)
   9 {
  10         char *host;
  11         char *path;
  12         int sv[2];
  13         char command[COMMAND_SIZE];
  14         char *posn;
  15         int sizen;
  16         int of;
  17         int i;
  18         pid_t pid;
  19
  20         if (!strcmp(url, "-")) {
  21                 *fd_in = 0;
  22                 *fd_out = 1;
  23                 return 0;
  24         }
  25
  26         host = strstr(url, "//");
  27         if (host) {
  28                 host += 2;
  29                 path = strchr(host, '/');
  30         } else {
  31                 host = url;
  32                 path = strchr(host, ':');
  33                 if (path)
  34                         *(path++) = '\0';
  35         }
  36         if (!path) {
  37                 return error("Bad URL: %s", url);
  38         }
  39         /* $GIT_RSH <host> "env GIT_DIR=<path> <remote_prog> <args...>" */
  40         sizen = COMMAND_SIZE;
  41         posn = command;
  42         of = 0;
  43         of |= add_to_string(&posn, &sizen, "env ", 0);
  44         of |= add_to_string(&posn, &sizen, GIT_DIR_ENVIRONMENT "=", 0);
  45         of |= add_to_string(&posn, &sizen, path, 1);
  46         of |= add_to_string(&posn, &sizen, " ", 0);
  47         of |= add_to_string(&posn, &sizen, remote_prog, 1);
  48
  49         for ( i = 0 ; i < rmt_argc ; i++ ) {
  50                 of |= add_to_string(&posn, &sizen, " ", 0);
  51                 of |= add_to_string(&posn, &sizen, rmt_argv[i], 1);
  52         }
  53
  54         of |= add_to_string(&posn, &sizen, " -", 0);
  55
  56         if ( of )
  57                 return error("Command line too long");
  58
  59         if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
  60                 return error("Couldn't create socket");
  61
  62         pid = fork();
  63         if (pid < 0)
  64                 return error("Couldn't fork");
  65         if (!pid) {
  66                 const char *ssh, *ssh_basename;
  67                 ssh = getenv("GIT_SSH");
  68                 if (!ssh) ssh = "ssh";
  69                 ssh_basename = strrchr(ssh, '/');
  70                 if (!ssh_basename)
  71                         ssh_basename = ssh;
  72                 else
  73                         ssh_basename++;
  74                 trace_printf("Calling '%s' '%s' '%s' '%s'\n",
  75                                 ssh, ssh_basename, host, command);
  76                 close(sv[1]);
  77                 dup2(sv[0], 0);
  78                 dup2(sv[0], 1);
  79                 execlp(ssh, ssh_basename, host, command, NULL);
  80         }
  81         close(sv[0]);
  82         *fd_in = sv[1];
  83         *fd_out = sv[1];
  84         return 0;
  85 }