builtin/remote-fd.c

   1 #include "builtin.h"
   2 #include "transport.h"
   3
   4 static const char usage_msg[] =
   5         "git remote-fd <remote> <url>";
   6
   7 /*
   8  * URL syntax:
   9  *      'fd::<inoutfd>[/<anything>]'            Read/write socket pair
  10  *                                              <inoutfd>.
  11  *      'fd::<infd>,<outfd>[/<anything>]'       Read pipe <infd> and write
  12  *                                              pipe <outfd>.
  13  *      [foo] indicates 'foo' is optional. <anything> is any string.
  14  *
  15  * The data output to <outfd>/<inoutfd> should be passed unmolested to
  16  * git-receive-pack/git-upload-pack/git-upload-archive and output of
  17  * git-receive-pack/git-upload-pack/git-upload-archive should be passed
  18  * unmolested to <infd>/<inoutfd>.
  19  *
  20  */
  21
  22 #define MAXCOMMAND 4096
  23
  24 static void command_loop(int input_fd, int output_fd)
  25 {
  26         char buffer[MAXCOMMAND];
  27
  28         while (1) {
  29                 size_t i;
  30                 if (!fgets(buffer, MAXCOMMAND - 1, stdin)) {
  31                         if (ferror(stdin))
  32                                 die("Input error");
  33                         return;
  34                 }
  35                 /* Strip end of line characters. */
  36                 i = strlen(buffer);
  37                 while (i > 0 && isspace(buffer[i - 1]))
  38                         buffer[--i] = 0;
  39
  40                 if (!strcmp(buffer, "capabilities")) {
  41                         printf("*connect\n\n");
  42                         fflush(stdout);
  43                 } else if (starts_with(buffer, "connect ")) {
  44                         printf("\n");
  45                         fflush(stdout);
  46                         if (bidirectional_transfer_loop(input_fd,
  47                                 output_fd))
  48                                 die("Copying data between file descriptors failed");
  49                         return;
  50                 } else {
  51                         die("Bad command: %s", buffer);
  52                 }
  53         }
  54 }
  55
  56 int cmd_remote_fd(int argc, const char **argv, const char *prefix)
  57 {
  58         int input_fd = -1;
  59         int output_fd = -1;
  60         char *end;
  61
  62         BUG_ON_NON_EMPTY_PREFIX(prefix);
  63
  64         if (argc != 3)
  65                 usage(usage_msg);
  66
  67         input_fd = (int)strtoul(argv[2], &end, 10);
  68
  69         if ((end == argv[2]) || (*end != ',' && *end != '/' && *end))
  70                 die("Bad URL syntax");
  71
  72         if (*end == '/' || !*end) {
  73                 output_fd = input_fd;
  74         } else {
  75                 char *end2;
  76                 output_fd = (int)strtoul(end + 1, &end2, 10);
  77
  78                 if ((end2 == end + 1) || (*end2 != '/' && *end2))
  79                         die("Bad URL syntax");
  80         }
  81
  82         command_loop(input_fd, output_fd);
  83         return 0;
  84 }