shell.c

   1 #include "cache.h"
   2 #include "quote.h"
   3 #include "exec_cmd.h"
   4 #include "strbuf.h"
   5
   6 static int do_generic_cmd(const char *me, char *arg)
   7 {
   8         const char *my_argv[4];
   9
  10         setup_path();
  11         if (!arg || !(arg = sq_dequote(arg)))
  12                 die("bad argument");
  13         if (prefixcmp(me, "git-"))
  14                 die("bad command");
  15
  16         my_argv[0] = me + 4;
  17         my_argv[1] = arg;
  18         my_argv[2] = NULL;
  19
  20         return execv_git_cmd(my_argv);
  21 }
  22
  23 static int do_cvs_cmd(const char *me, char *arg)
  24 {
  25         const char *cvsserver_argv[3] = {
  26                 "cvsserver", "server", NULL
  27         };
  28
  29         if (!arg || strcmp(arg, "server"))
  30                 die("git-cvsserver only handles server: %s", arg);
  31
  32         setup_path();
  33         return execv_git_cmd(cvsserver_argv);
  34 }
  35
  36
  37 static struct commands {
  38         const char *name;
  39         int (*exec)(const char *me, char *arg);
  40 } cmd_list[] = {
  41         { "git-receive-pack", do_generic_cmd },
  42         { "git-upload-pack", do_generic_cmd },
  43         { "cvs", do_cvs_cmd },
  44         { NULL },
  45 };
  46
  47 int main(int argc, char **argv)
  48 {
  49         char *prog;
  50         struct commands *cmd;
  51         int devnull_fd;
  52
  53         /*
  54          * Always open file descriptors 0/1/2 to avoid clobbering files
  55          * in die().  It also avoids not messing up when the pipes are
  56          * dup'ed onto stdin/stdout/stderr in the child processes we spawn.
  57          */
  58         devnull_fd = open("/dev/null", O_RDWR);
  59         while (devnull_fd >= 0 && devnull_fd <= 2)
  60                 devnull_fd = dup(devnull_fd);
  61         if (devnull_fd == -1)
  62                 die("opening /dev/null failed (%s)", strerror(errno));
  63         close (devnull_fd);
  64
  65         /*
  66          * Special hack to pretend to be a CVS server
  67          */
  68         if (argc == 2 && !strcmp(argv[1], "cvs server"))
  69                 argv--;
  70
  71         /*
  72          * We do not accept anything but "-c" followed by "cmd arg",
  73          * where "cmd" is a very limited subset of git commands.
  74          */
  75         else if (argc != 3 || strcmp(argv[1], "-c"))
  76                 die("What do you think I am? A shell?");
  77
  78         prog = argv[2];
  79         if (!strncmp(prog, "git", 3) && isspace(prog[3]))
  80                 /* Accept "git foo" as if the caller said "git-foo". */
  81                 prog[3] = '-';
  82
  83         for (cmd = cmd_list ; cmd->name ; cmd++) {
  84                 int len = strlen(cmd->name);
  85                 char *arg;
  86                 if (strncmp(cmd->name, prog, len))
  87                         continue;
  88                 arg = NULL;
  89                 switch (prog[len]) {
  90                 case '\0':
  91                         arg = NULL;
  92                         break;
  93                 case ' ':
  94                         arg = prog + len + 1;
  95                         break;
  96                 default:
  97                         continue;
  98                 }
  99                 exit(cmd->exec(cmd->name, arg));
 100         }
 101         die("unrecognized command '%s'", prog);
 102 }