Andrew's git - gitweb.git/blob

   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/*
  12 * Append a string to a string buffer, with or without shell quoting.
  13 * Return true if the buffer overflowed.
  14 */
  15static int add_to_string(char **ptrp, int *sizep, const char *str, int quote)
  16{
  17        char *p = *ptrp;
  18        int size = *sizep;
  19        int oc;
  20        int err = 0;
  21
  22        if ( quote ) {
  23                oc = sq_quote_buf(p, size, str);
  24        } else {
  25                oc = strlen(str);
  26                memcpy(p, str, (oc >= size) ? size-1 : oc);
  27        }
  28
  29        if ( oc >= size ) {
  30                err = 1;
  31                oc = size-1;
  32        }
  33
  34        *ptrp  += oc;
  35        **ptrp  = '\0';
  36        *sizep -= oc;
  37        return err;
  38}
  39
  40int setup_connection(int *fd_in, int *fd_out, const char *remote_prog, 
  41                     char *url, int rmt_argc, char **rmt_argv)
  42{
  43        char *host;
  44        char *path;
  45        int sv[2];
  46        char command[COMMAND_SIZE];
  47        char *posn;
  48        int sizen;
  49        int of;
  50        int i;
  51        pid_t pid;
  52
  53        if (!strcmp(url, "-")) {
  54                *fd_in = 0;
  55                *fd_out = 1;
  56                return 0;
  57        }
  58
  59        host = strstr(url, "//");
  60        if (host) {
  61                host += 2;
  62                path = strchr(host, '/');
  63        } else {
  64                host = url;
  65                path = strchr(host, ':');
  66                if (path)
  67                        *(path++) = '\0';
  68        }
  69        if (!path) {
  70                return error("Bad URL: %s", url);
  71        }
  72        /* $GIT_RSH <host> "env GIT_DIR=<path> <remote_prog> <args...>" */
  73        sizen = COMMAND_SIZE;
  74        posn = command;
  75        of = 0;
  76        of |= add_to_string(&posn, &sizen, "env ", 0);
  77        of |= add_to_string(&posn, &sizen, GIT_DIR_ENVIRONMENT "=", 0);
  78        of |= add_to_string(&posn, &sizen, path, 1);
  79        of |= add_to_string(&posn, &sizen, " ", 0);
  80        of |= add_to_string(&posn, &sizen, remote_prog, 1);
  81
  82        for ( i = 0 ; i < rmt_argc ; i++ ) {
  83                of |= add_to_string(&posn, &sizen, " ", 0);
  84                of |= add_to_string(&posn, &sizen, rmt_argv[i], 1);
  85        }
  86
  87        of |= add_to_string(&posn, &sizen, " -", 0);
  88
  89        if ( of )
  90                return error("Command line too long");
  91
  92        if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
  93                return error("Couldn't create socket");
  94
  95        pid = fork();
  96        if (pid < 0)
  97                return error("Couldn't fork");
  98        if (!pid) {
  99                const char *ssh, *ssh_basename;
 100                ssh = getenv("GIT_SSH");
 101                if (!ssh) ssh = "ssh";
 102                ssh_basename = strrchr(ssh, '/');
 103                if (!ssh_basename)
 104                        ssh_basename = ssh;
 105                else
 106                        ssh_basename++;
 107                close(sv[1]);
 108                dup2(sv[0], 0);
 109                dup2(sv[0], 1);
 110                execlp(ssh, ssh_basename, host, command, NULL);
 111        }
 112        close(sv[0]);
 113        *fd_in = sv[1];
 114        *fd_out = sv[1];
 115        return 0;
 116}