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 3 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, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22
  23 /*******************************************************************
  24 this is like socketpair but uses tcp. It is used by the Samba
  25 regression test code
  26 The function guarantees that nobody else can attach to the socket,
  27 or if they do that this function fails and the socket gets closed
  28 returns 0 on success, -1 on failure
  29 the resulting file descriptors are symmetrical
  30  ******************************************************************/
  31 static int socketpair_tcp(int fd[2])
  32 {
  33         int listener;
  34         struct sockaddr_in sock;
  35         struct sockaddr_in sock2;
  36         socklen_t socklen = sizeof(sock);
  37         int connect_done = 0;
  38
  39         fd[0] = fd[1] = listener = -1;
  40
  41         memset(&sock, 0, sizeof(sock));
  42
  43         if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
  44
  45         memset(&sock2, 0, sizeof(sock2));
  46 #ifdef HAVE_SOCK_SIN_LEN
  47         sock2.sin_len = sizeof(sock2);
  48 #endif
  49         sock2.sin_family = PF_INET;
  50
  51         if (bind(listener, (struct sockaddr *)&sock2, sizeof(sock2)) != 0) goto failed;
  52
  53         if (listen(listener, 1) != 0) goto failed;
  54
  55         if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0) goto failed;
  56
  57         if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
  58
  59         set_blocking(fd[1], 0);
  60
  61         sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  62
  63         if (sys_connect(fd[1], (struct sockaddr *)&sock) == -1) {
  64                 if (errno != EINPROGRESS) goto failed;
  65         } else {
  66                 connect_done = 1;
  67         }
  68
  69         if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1) goto failed;
  70
  71         close(listener);
  72         if (connect_done == 0) {
  73                 if (sys_connect(fd[1], (struct sockaddr *)&sock) != 0
  74                     && errno != EISCONN) goto failed;
  75         }
  76
  77         set_blocking(fd[1], 1);
  78
  79         /* all OK! */
  80         return 0;
  81
  82  failed:
  83         if (fd[0] != -1) close(fd[0]);
  84         if (fd[1] != -1) close(fd[1]);
  85         if (listener != -1) close(listener);
  86         return -1;
  87 }
  88
  89
  90 /*******************************************************************
  91 run a program on a local tcp socket, this is used to launch smbd
  92 when regression testing
  93 the return value is a socket which is attached to a subprocess
  94 running "prog". stdin and stdout are attached. stderr is left
  95 attached to the original stderr
  96  ******************************************************************/
  97 int sock_exec(const char *prog)
  98 {
  99         int fd[2];
 100         if (socketpair_tcp(fd) != 0) {
 101                 DEBUG(0,("socketpair_tcp failed (%s)\n", strerror(errno)));
 102                 return -1;
 103         }
 104         if (fork() == 0) {
 105                 close(fd[0]);
 106                 close(0);
 107                 close(1);
 108                 if (dup(fd[1]) == -1) {
 109                         exit(1);
 110                 }
 111                 if (dup(fd[1]) == -1) {
 112                         exit(1);
 113                 }
 114                 exit(system(prog));
 115         }
 116         close(fd[1]);
 117         return fd[0];
 118 }