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AC_DEFUN([CONFTEST_FDPASS],[[
AC_LANG_SOURCE([[
$1
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#include <signal.h>
#include <sys/socket.h>
#if !defined CMSG_SPACE || !defined CMSG_LEN
#ifndef ALIGN
#define ALIGN(len) len
#endif
#ifndef CMSG_SPACE
#define CMSG_SPACE(len) (ALIGN(sizeof(struct cmsghdr)) + ALIGN(len))
#endif
#ifndef CMSG_LEN
#define CMSG_LEN(len) (ALIGN(sizeof(struct cmsghdr)) + len)
#endif
#endif
#define TEST "test"
static int send_fd(int s, int fd)
{
struct msghdr msg;
struct cmsghdr *cmsg;
unsigned char fdbuf[CMSG_SPACE(sizeof(int))];
struct iovec iov[1];
char dummy[] = "";
iov[0].iov_base = dummy;
iov[0].iov_len = 1;
memset(&msg, 0, sizeof(msg));
msg.msg_control = fdbuf;
/* must send/receive at least one byte */
msg.msg_iov = iov;
msg.msg_iovlen = 1;
msg.msg_controllen = CMSG_LEN(sizeof(int));
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
*(int *)CMSG_DATA(cmsg) = fd;
if (sendmsg(s, &msg, 0) == -1) {
perror("sendmsg");
close(s);
return -1;
}
return 0;
}
static int testfd(int desc)
{
char buf[256];
if(read(desc, buf, sizeof(buf)) != sizeof(TEST)) {
fprintf(stderr, "test data not received correctly!");
return 1;
}
return memcmp(buf, TEST, sizeof(TEST));
}
static int recv_fd(int desc)
{
unsigned char buf[CMSG_SPACE(sizeof(int))];
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov[1];
char dummy;
int ret=2;
memset(&msg, 0, sizeof(msg));
iov[0].iov_base = &dummy;
iov[0].iov_len = 1;
msg.msg_iov = iov;
msg.msg_iovlen = 1;
msg.msg_control = buf;
msg.msg_controllen = sizeof(buf);
if (recvmsg(desc, &msg, 0) == -1) {
perror("recvmsg failed!");
return -1;
}
if ((msg.msg_flags & MSG_TRUNC) || (msg.msg_flags & MSG_CTRUNC)) {
fprintf(stderr, "control message truncated");
return -1;
}
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_len == CMSG_LEN(sizeof(int)) &&
cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
int fd = *(int *)CMSG_DATA(cmsg);
ret = testfd(fd);
close(fd);
}
}
return ret;
}
int main(void)
{
int fd[2];
int pip[2];
pid_t pid;
int status;
if(pipe(pip)) {
perror("pipe");
return 1;
}
if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
perror("socketpair");
return 1;
}
if((pid=fork()) < 0) {
perror("fork");
} else if (!pid) {
exit( recv_fd(fd[1]) );
} else {
/* parent */
if(send_fd(fd[0], pip[0]) == -1) {
kill(pid, 9);
waitpid(pid, NULL, 0);
return 2;
}
if(write(pip[1], TEST, sizeof(TEST)) != sizeof(TEST)) {
close(pip[1]);
return -1;
}
close(pip[1]);
waitpid(pid, &status, 0);
}
return status;
}
]])
]])
AC_DEFUN([AC_C_FDPASSING],[
dnl Check if we can do fd passing
dnl Submitted by Richard Lyons <frob-clamav@webcentral.com.au>
AC_CHECK_FUNCS([recvmsg sendmsg])
AC_CACHE_CHECK([for msg_control field in struct msghdr],
[ac_cv_have_control_in_msghdr], [
AC_TRY_COMPILE(
[
#define _XOPEN_SOURCE 500
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <sys/socket.h>
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
],
[
#ifdef msg_control
#error msg_control defined
#endif
struct msghdr m;
m.msg_control = 0;
return 0;
], [ ac_cv_have_control_in_msghdr="yes" ], [ ac_cv_have_control_in_msghdr="no" ])
])
if test "x$ac_cv_have_control_in_msghdr" = "xyes" ; then
dnl Check whether FD passing works <edwin@clamav.net>
AC_MSG_CHECKING([BSD 4.4 / RFC2292 style fd passing])
AC_ARG_ENABLE([fdpassing],[AS_HELP_STRING([--disable-fdpassing], [do not build file descriptor passing support])],
want_fdpassing=$enableval, want_fdpassing="yes")
if test "x$want_fdpassing" = "xyes"; then
dnl Try without _XOPEN_SOURCE first
AC_RUN_IFELSE(CONFTEST_FDPASS([]), [have_fdpass=1; fdpass_need_xopen=0], [have_fdpass=0],[have_fdpass=0])
if test $have_fdpass = 0; then
AC_RUN_IFELSE(CONFTEST_FDPASS([#define _XOPEN_SOURCE 500]), [have_fdpass=1; fdpass_need_xopen=1],[have_fdpass=0],[have_fdpass=0])
fi
if test $have_fdpass = 1; then
AC_DEFINE([HAVE_FD_PASSING],1,[have working file descriptor passing support])
if test $fdpass_need_xopen = 1; then
AC_DEFINE([FDPASS_NEED_XOPEN],1,[whether _XOPEN_SOURCE needs to be defined for fd passing to work])
AC_MSG_RESULT([yes, by defining _XOPEN_SOURCE])
else
AC_MSG_RESULT([yes])
fi
else
AC_MSG_RESULT([no])
fi
else
AC_MSG_RESULT([disabled])
fi
fi
])
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