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         int i;
  14         pid_t pid;
  15         struct strbuf cmd;
  16
  17         if (!strcmp(url, "-")) {
  18                 *fd_in = 0;
  19                 *fd_out = 1;
  20                 return 0;
  21         }
  22
  23         host = strstr(url, "//");
  24         if (host) {
  25                 host += 2;
  26                 path = strchr(host, '/');
  27         } else {
  28                 host = url;
  29                 path = strchr(host, ':');
  30                 if (path)
  31                         *(path++) = '\0';
  32         }
  33         if (!path) {
  34                 return error("Bad URL: %s", url);
  35         }
  36
  37         /* $GIT_RSH <host> "env GIT_DIR=<path> <remote_prog> <args...>" */
  38         strbuf_init(&cmd, COMMAND_SIZE);
  39         strbuf_addstr(&cmd, "env ");
  40         strbuf_addstr(&cmd, GIT_DIR_ENVIRONMENT "=");
  41         sq_quote_buf(&cmd, path);
  42         strbuf_addch(&cmd, ' ');
  43         sq_quote_buf(&cmd, remote_prog);
  44
  45         for (i = 0 ; i < rmt_argc ; i++) {
  46                 strbuf_addch(&cmd, ' ');
  47                 sq_quote_buf(&cmd, rmt_argv[i]);
  48         }
  49
  50         strbuf_addstr(&cmd, " -");
  51
  52         if (cmd.len >= COMMAND_SIZE)
  53                 return error("Command line too long");
  54
  55         if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
  56                 return error("Couldn't create socket");
  57
  58         pid = fork();
  59         if (pid < 0)
  60                 return error("Couldn't fork");
  61         if (!pid) {
  62                 const char *ssh, *ssh_basename;
  63                 ssh = getenv("GIT_SSH");
  64                 if (!ssh) ssh = "ssh";
  65                 ssh_basename = strrchr(ssh, '/');
  66                 if (!ssh_basename)
  67                         ssh_basename = ssh;
  68                 else
  69                         ssh_basename++;
  70                 close(sv[1]);
  71                 dup2(sv[0], 0);
  72                 dup2(sv[0], 1);
  73                 execlp(ssh, ssh_basename, host, cmd.buf, NULL);
  74         }
  75         close(sv[0]);
  76         *fd_in = sv[1];
  77         *fd_out = sv[1];
  78         return 0;
  79 }