qemu/os-posix.c
Jes Sorensen 8847cfe8aa Move runas handling from vl.c to OS specific files.
Move code to handle runas, ie. change of user id of QEMU process
to OS specific files and provide dummy stub for Win32.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Acked-by: Juan Quintela <quintela@redhat.com>
Acked-by: Richard Henderson <rth@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-06-12 08:49:15 +03:00

180 lines
4.7 KiB
C

/*
* os-posix.c
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2010 Red Hat, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <pwd.h>
#include <libgen.h>
/* Needed early for CONFIG_BSD etc. */
#include "config-host.h"
#include "sysemu.h"
#include "net/slirp.h"
#include "qemu-options.h"
static struct passwd *user_pwd;
void os_setup_early_signal_handling(void)
{
struct sigaction act;
sigfillset(&act.sa_mask);
act.sa_flags = 0;
act.sa_handler = SIG_IGN;
sigaction(SIGPIPE, &act, NULL);
}
static void termsig_handler(int signal)
{
qemu_system_shutdown_request();
}
static void sigchld_handler(int signal)
{
waitpid(-1, NULL, WNOHANG);
}
void os_setup_signal_handling(void)
{
struct sigaction act;
memset(&act, 0, sizeof(act));
act.sa_handler = termsig_handler;
sigaction(SIGINT, &act, NULL);
sigaction(SIGHUP, &act, NULL);
sigaction(SIGTERM, &act, NULL);
act.sa_handler = sigchld_handler;
act.sa_flags = SA_NOCLDSTOP;
sigaction(SIGCHLD, &act, NULL);
}
/* Find a likely location for support files using the location of the binary.
For installed binaries this will be "$bindir/../share/qemu". When
running from the build tree this will be "$bindir/../pc-bios". */
#define SHARE_SUFFIX "/share/qemu"
#define BUILD_SUFFIX "/pc-bios"
char *os_find_datadir(const char *argv0)
{
char *dir;
char *p = NULL;
char *res;
char buf[PATH_MAX];
size_t max_len;
#if defined(__linux__)
{
int len;
len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
if (len > 0) {
buf[len] = 0;
p = buf;
}
}
#elif defined(__FreeBSD__)
{
static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
size_t len = sizeof(buf) - 1;
*buf = '\0';
if (!sysctl(mib, sizeof(mib)/sizeof(*mib), buf, &len, NULL, 0) &&
*buf) {
buf[sizeof(buf) - 1] = '\0';
p = buf;
}
}
#endif
/* If we don't have any way of figuring out the actual executable
location then try argv[0]. */
if (!p) {
p = realpath(argv0, buf);
if (!p) {
return NULL;
}
}
dir = dirname(p);
dir = dirname(dir);
max_len = strlen(dir) +
MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
res = qemu_mallocz(max_len);
snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX);
if (access(res, R_OK)) {
snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX);
if (access(res, R_OK)) {
qemu_free(res);
res = NULL;
}
}
return res;
}
#undef SHARE_SUFFIX
#undef BUILD_SUFFIX
/*
* Parse OS specific command line options.
* return 0 if option handled, -1 otherwise
*/
void os_parse_cmd_args(int index, const char *optarg)
{
switch (index) {
#ifdef CONFIG_SLIRP
case QEMU_OPTION_smb:
if (net_slirp_smb(optarg) < 0)
exit(1);
break;
#endif
case QEMU_OPTION_runas:
user_pwd = getpwnam(optarg);
if (!user_pwd) {
fprintf(stderr, "User \"%s\" doesn't exist\n", optarg);
exit(1);
}
break;
}
return;
}
void os_change_process_uid(void)
{
if (user_pwd) {
if (setgid(user_pwd->pw_gid) < 0) {
fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid);
exit(1);
}
if (setuid(user_pwd->pw_uid) < 0) {
fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid);
exit(1);
}
if (setuid(0) != -1) {
fprintf(stderr, "Dropping privileges failed\n");
exit(1);
}
}
}