libvirt/tests/commandhelper.c
Daniel P. Berrange eae746b2d7 Stop linking tests/commandhelper to libvirt code
The commandhelper binary is a helper for commandtest that
validates what file handles were inherited. For this to
work reliably we must not have any libraries that leak
file descriptors into commandhelper. Unfortunately some
versions of gnutls will intentionally open file handles
at library load time via a constructor function.

We previously hacked around this in

  commit 4cbc15d037
  Author: Martin Kletzander <mkletzan@redhat.com>
  Date:   Fri May 2 09:55:52 2014 +0200

    tests: don't fail with newer gnutls

    gnutls-3.3.0 and newer leaves 2 FDs open in order to be backwards
    compatible when it comes to chrooted binaries [1].  Linking
    commandhelper with gnutls then leaves these two FDs open and
    commandtest fails thanks to that.  This patch does not link
    commandhelper with libvirt.la, but rather only the utilities making
    the test pass.

    Based on suggestion from Daniel [2].

    [1] http://lists.gnutls.org/pipermail/gnutls-help/2014-April/003429.html
    [2] https://www.redhat.com/archives/libvir-list/2014-April/msg01119.html

That fix relied on fact that while libvirt.so linked with
gnutls, libvirt_util.la did not link to it.  With the
introduction of the util/vircrypto.c file that assumption
is no longer valid. We must not link to libvirt_util.la
at all - only gnulib and libc can (hopefully) be relied
on not to open random file descriptors in constructors.

Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-09-20 14:32:12 +01:00

172 lines
4.0 KiB
C

/*
* commandhelper.c: Auxiliary program for commandtest
*
* Copyright (C) 2010-2014 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include "internal.h"
#ifndef WIN32
# define VIR_FROM_THIS VIR_FROM_NONE
static int envsort(const void *a, const void *b)
{
const char *const*astrptr = a;
const char *const*bstrptr = b;
const char *astr = *astrptr;
const char *bstr = *bstrptr;
char *aeq = strchr(astr, '=');
char *beq = strchr(bstr, '=');
char *akey;
char *bkey;
int ret;
if (!(akey = strndup(astr, aeq - astr)))
abort();
if (!(bkey = strndup(bstr, beq - bstr)))
abort();
ret = strcmp(akey, bkey);
free(akey);
free(bkey);
return ret;
}
int main(int argc, char **argv) {
size_t i, n;
int open_max;
char **origenv;
char **newenv = NULL;
char *cwd;
FILE *log = fopen(abs_builddir "/commandhelper.log", "w");
int ret = EXIT_FAILURE;
if (!log)
goto cleanup;
for (i = 1; i < argc; i++)
fprintf(log, "ARG:%s\n", argv[i]);
origenv = environ;
n = 0;
while (*origenv != NULL) {
n++;
origenv++;
}
if (!(newenv = malloc(sizeof(*newenv) * n)))
abort();
origenv = environ;
n = i = 0;
while (*origenv != NULL) {
newenv[i++] = *origenv;
n++;
origenv++;
}
qsort(newenv, n, sizeof(newenv[0]), envsort);
for (i = 0; i < n; i++) {
/* Ignore the variables used to instruct the loader into
* behaving differently, as they could throw the tests off. */
if (!STRPREFIX(newenv[i], "LD_"))
fprintf(log, "ENV:%s\n", newenv[i]);
}
open_max = sysconf(_SC_OPEN_MAX);
if (open_max < 0)
goto cleanup;
for (i = 0; i < open_max; i++) {
int f;
int closed;
if (i == fileno(log))
continue;
closed = fcntl(i, F_GETFD, &f) == -1 &&
errno == EBADF;
if (!closed)
fprintf(log, "FD:%zu\n", i);
}
fprintf(log, "DAEMON:%s\n", getpgrp() == getsid(0) ? "yes" : "no");
if (!(cwd = getcwd(NULL, 0)))
goto cleanup;
if (strlen(cwd) > strlen(".../commanddata") &&
STREQ(cwd + strlen(cwd) - strlen("/commanddata"), "/commanddata"))
strcpy(cwd, ".../commanddata");
fprintf(log, "CWD:%s\n", cwd);
free(cwd);
fprintf(log, "UMASK:%04o\n", umask(0));
if (argc > 1 && STREQ(argv[1], "--close-stdin")) {
if (freopen("/dev/null", "r", stdin) != stdin)
goto cleanup;
usleep(100*1000);
}
char buf[1024];
ssize_t got;
fprintf(stdout, "BEGIN STDOUT\n");
fflush(stdout);
fprintf(stderr, "BEGIN STDERR\n");
fflush(stderr);
for (;;) {
got = read(STDIN_FILENO, buf, sizeof(buf));
if (got < 0)
goto cleanup;
if (got == 0)
break;
if (write(STDOUT_FILENO, buf, got) != got)
goto cleanup;
if (write(STDERR_FILENO, buf, got) != got)
goto cleanup;
}
fprintf(stdout, "END STDOUT\n");
fflush(stdout);
fprintf(stderr, "END STDERR\n");
fflush(stderr);
ret = EXIT_SUCCESS;
cleanup:
fclose(log);
free(newenv);
return ret;
}
#else
int
main(void)
{
return EXIT_AM_SKIP;
}
#endif