source/lib/sock_exec.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba utility functions
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Tim Potter      2000-2001
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24 /*******************************************************************
  25 this is like socketpair but uses tcp. It is used by the Samba
  26 regression test code
  27 The function guarantees that nobody else can attach to the socket,
  28 or if they do that this function fails and the socket gets closed
  29 returns 0 on success, -1 on failure
  30 the resulting file descriptors are symmetrical
  31  ******************************************************************/
  32 static int socketpair_tcp(int fd[2])
  33 {
  34         int listener;
  35         struct sockaddr_in sock;
  36         struct sockaddr_in sock2;
  37         socklen_t socklen = sizeof(sock);
  38         int connect_done = 0;
  39
  40         fd[0] = fd[1] = listener = -1;
  41
  42         memset(&sock, 0, sizeof(sock));
  43
  44         if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
  45
  46         memset(&sock2, 0, sizeof(sock2));
  47 #ifdef HAVE_SOCK_SIN_LEN
  48         sock2.sin_len = sizeof(sock2);
  49 #endif
  50         sock2.sin_family = PF_INET;
  51
  52         bind(listener, (struct sockaddr *)&sock2, sizeof(sock2));
  53
  54         if (listen(listener, 1) != 0) goto failed;
  55
  56         if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0) goto failed;
  57
  58         if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
  59
  60         set_blocking(fd[1], 0);
  61
  62         sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  63
  64         if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) == -1) {
  65                 if (errno != EINPROGRESS) goto failed;
  66         } else {
  67                 connect_done = 1;
  68         }
  69
  70         if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1) goto failed;
  71
  72         close(listener);
  73         if (connect_done == 0) {
  74                 if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) != 0
  75                     && errno != EISCONN) goto failed;
  76         }
  77
  78         set_blocking(fd[1], 1);
  79
  80         /* all OK! */
  81         return 0;
  82
  83  failed:
  84         if (fd[0] != -1) close(fd[0]);
  85         if (fd[1] != -1) close(fd[1]);
  86         if (listener != -1) close(listener);
  87         return -1;
  88 }
  89
  90
  91 /*******************************************************************
  92 run a program on a local tcp socket, this is used to launch smbd
  93 when regression testing
  94 the return value is a socket which is attached to a subprocess
  95 running "prog". stdin and stdout are attached. stderr is left
  96 attached to the original stderr
  97  ******************************************************************/
  98 int sock_exec(const char *prog)
  99 {
 100         int fd[2];
 101         if (socketpair_tcp(fd) != 0) {
 102                 DEBUG(0,("socketpair_tcp failed (%s)\n", strerror(errno)));
 103                 return -1;
 104         }
 105         if (fork() == 0) {
 106                 close(fd[0]);
 107                 close(0);
 108                 close(1);
 109                 dup(fd[1]);
 110                 dup(fd[1]);
 111                 exit(system(prog));
 112         }
 113         close(fd[1]);
 114         return fd[0];
 115 }