Move virRun, virExec*, virFork to util/command

Seems reasonable to have all command wrappers in the same place

v2:
    Dont move SetInherit

v3:
    Comment spelling fix
    Adjust WARN0 comment
    Remove spurious #include movement
    Don't include sys/types.h
    Combine virExec enums

Signed-off-by: Cole Robinson <crobinso@redhat.com>
This commit is contained in:
Cole Robinson 2011-05-10 14:42:59 -04:00
parent 3c269b51a6
commit 02e86910e2
13 changed files with 602 additions and 595 deletions

2
cfg.mk
View File

@ -622,7 +622,7 @@ exclude_file_name_regexp--sc_prohibit_doubled_word = ^po/
exclude_file_name_regexp--sc_prohibit_empty_lines_at_EOF = \
(^docs/api_extension/|^tests/qemuhelpdata/|\.(gif|ico|png)$$)
_src2=src/(util/util|libvirt|lxc/lxc_controller)
_src2=src/(util/command|libvirt|lxc/lxc_controller)
exclude_file_name_regexp--sc_prohibit_fork_wrappers = \
(^docs|^($(_src2)|tests/testutils|daemon/libvirtd)\.c$$)

View File

@ -133,6 +133,8 @@ virCommandTransferFD;
virCommandTranslateStatus;
virCommandWait;
virCommandWriteArgLog;
virFork;
virRun;
# conf.h
@ -968,7 +970,6 @@ virEnumFromString;
virEnumToString;
virEventAddHandle;
virEventRemoveHandle;
virExecWithHook;
virFileAbsPath;
virFileBuildPath;
virFileDeletePid;
@ -991,7 +992,6 @@ virFileStripSuffix;
virFileWaitForDevices;
virFileWriteStr;
virFindFileInPath;
virFork;
virFormatMacAddr;
virGenerateMacAddr;
virGetGroupID;
@ -1010,7 +1010,6 @@ virParseVersionString;
virPipeReadUntilEOF;
virRandom;
virRandomInitialize;
virRun;
virSetBlocking;
virSetCloseExec;
virSetInherit;

View File

@ -21,7 +21,7 @@
#include "internal.h"
#include "logging.h"
#include "memory.h"
#include "util.h"
#include "command.h"
#include "virterror_internal.h"
#define VIR_FROM_THIS VIR_FROM_LXC

View File

@ -39,6 +39,7 @@
#include "nwfilter_gentech_driver.h"
#include "nwfilter_ebiptables_driver.h"
#include "files.h"
#include "command.h"
#define VIR_FROM_THIS VIR_FROM_NWFILTER

View File

@ -41,7 +41,7 @@
#include "storage_backend_fs.h"
#include "storage_conf.h"
#include "storage_file.h"
#include "util.h"
#include "command.h"
#include "memory.h"
#include "xml.h"
#include "files.h"

View File

@ -34,7 +34,7 @@
#include "virterror_internal.h"
#include "storage_backend_logical.h"
#include "storage_conf.h"
#include "util.h"
#include "command.h"
#include "memory.h"
#include "logging.h"
#include "files.h"

View File

@ -27,6 +27,11 @@
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <fcntl.h>
#if HAVE_CAPNG
# include <cap-ng.h>
#endif
#include "command.h"
#include "memory.h"
@ -35,6 +40,7 @@
#include "logging.h"
#include "files.h"
#include "buf.h"
#include "ignore-value.h"
#include <stdlib.h>
@ -44,9 +50,13 @@
virReportErrorHelper(VIR_FROM_NONE, code, __FILE__, \
__FUNCTION__, __LINE__, __VA_ARGS__)
/* Flags for virExecWithHook */
enum {
/* Internal-use extension beyond public VIR_EXEC_ flags */
VIR_EXEC_RUN_SYNC = 0x40000000,
VIR_EXEC_NONE = 0,
VIR_EXEC_NONBLOCK = (1 << 0),
VIR_EXEC_DAEMON = (1 << 1),
VIR_EXEC_CLEAR_CAPS = (1 << 2),
VIR_EXEC_RUN_SYNC = (1 << 3),
};
struct _virCommand {
@ -91,6 +101,558 @@ struct _virCommand {
bool reap;
};
#ifndef WIN32
# if HAVE_CAPNG
static int virClearCapabilities(void)
{
int ret;
capng_clear(CAPNG_SELECT_BOTH);
if ((ret = capng_apply(CAPNG_SELECT_BOTH)) < 0) {
virCommandError(VIR_ERR_INTERNAL_ERROR,
_("cannot clear process capabilities %d"), ret);
return -1;
}
return 0;
}
# else
static int virClearCapabilities(void)
{
// VIR_WARN("libcap-ng support not compiled in, unable to clear "
// "capabilities");
return 0;
}
# endif
/* virFork() - fork a new process while avoiding various race/deadlock
conditions
@pid - a pointer to a pid_t that will receive the return value from
fork()
on return from virFork(), if *pid < 0, the fork failed and there is
no new process. Otherwise, just like fork(), if *pid == 0, it is the
child process returning, and if *pid > 0, it is the parent.
Even if *pid >= 0, if the return value from virFork() is < 0, it
indicates a failure that occurred in the parent or child process
after the fork. In this case, the child process should call
_exit(EXIT_FAILURE) after doing any additional error reporting.
*/
int virFork(pid_t *pid) {
# ifdef HAVE_PTHREAD_SIGMASK
sigset_t oldmask, newmask;
# endif
struct sigaction sig_action;
int saved_errno, ret = -1;
*pid = -1;
/*
* Need to block signals now, so that child process can safely
* kill off caller's signal handlers without a race.
*/
# ifdef HAVE_PTHREAD_SIGMASK
sigfillset(&newmask);
if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) {
saved_errno = errno;
virReportSystemError(errno,
"%s", _("cannot block signals"));
goto cleanup;
}
# endif
/* Ensure we hold the logging lock, to protect child processes
* from deadlocking on another thread's inherited mutex state */
virLogLock();
*pid = fork();
saved_errno = errno; /* save for caller */
/* Unlock for both parent and child process */
virLogUnlock();
if (*pid < 0) {
# ifdef HAVE_PTHREAD_SIGMASK
/* attempt to restore signal mask, but ignore failure, to
avoid obscuring the fork failure */
ignore_value (pthread_sigmask(SIG_SETMASK, &oldmask, NULL));
# endif
virReportSystemError(saved_errno,
"%s", _("cannot fork child process"));
goto cleanup;
}
if (*pid) {
/* parent process */
# ifdef HAVE_PTHREAD_SIGMASK
/* Restore our original signal mask now that the child is
safely running */
if (pthread_sigmask(SIG_SETMASK, &oldmask, NULL) != 0) {
saved_errno = errno; /* save for caller */
virReportSystemError(errno, "%s", _("cannot unblock signals"));
goto cleanup;
}
# endif
ret = 0;
} else {
/* child process */
int logprio;
int i;
/* Remove any error callback so errors in child now
get sent to stderr where they stand a fighting chance
of being seen / logged */
virSetErrorFunc(NULL, NULL);
virSetErrorLogPriorityFunc(NULL);
/* Make sure any hook logging is sent to stderr, since child
* process may close the logfile FDs */
logprio = virLogGetDefaultPriority();
virLogReset();
virLogSetDefaultPriority(logprio);
/* Clear out all signal handlers from parent so nothing
unexpected can happen in our child once we unblock
signals */
sig_action.sa_handler = SIG_DFL;
sig_action.sa_flags = 0;
sigemptyset(&sig_action.sa_mask);
for (i = 1; i < NSIG; i++) {
/* Only possible errors are EFAULT or EINVAL
The former wont happen, the latter we
expect, so no need to check return value */
sigaction(i, &sig_action, NULL);
}
# ifdef HAVE_PTHREAD_SIGMASK
/* Unmask all signals in child, since we've no idea
what the caller's done with their signal mask
and don't want to propagate that to children */
sigemptyset(&newmask);
if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) {
saved_errno = errno; /* save for caller */
virReportSystemError(errno, "%s", _("cannot unblock signals"));
goto cleanup;
}
# endif
ret = 0;
}
cleanup:
if (ret < 0)
errno = saved_errno;
return ret;
}
/*
* @argv argv to exec
* @envp optional environment to use for exec
* @keepfd options fd_ret to keep open for child process
* @retpid optional pointer to store child process pid
* @infd optional file descriptor to use as child input, otherwise /dev/null
* @outfd optional pointer to communicate output fd behavior
* outfd == NULL : Use /dev/null
* *outfd == -1 : Use a new fd
* *outfd != -1 : Use *outfd
* @errfd optional pointer to communcate error fd behavior. See outfd
* @flags possible combination of the following:
* VIR_EXEC_NONE : Default function behavior
* VIR_EXEC_NONBLOCK : Set child process output fd's as non-blocking
* VIR_EXEC_DAEMON : Daemonize the child process
* @hook optional virExecHook function to call prior to exec
* @data data to pass to the hook function
* @pidfile path to use as pidfile for daemonized process (needs DAEMON flag)
*/
static int
virExecWithHook(const char *const*argv,
const char *const*envp,
const fd_set *keepfd,
pid_t *retpid,
int infd, int *outfd, int *errfd,
int flags,
virExecHook hook,
void *data,
char *pidfile)
{
pid_t pid;
int null, i, openmax;
int pipeout[2] = {-1,-1};
int pipeerr[2] = {-1,-1};
int childout = -1;
int childerr = -1;
int tmpfd;
const char *binary = NULL;
int forkRet;
char *argv_str = NULL;
char *envp_str = NULL;
if ((argv_str = virArgvToString(argv)) == NULL) {
virReportOOMError();
return -1;
}
if (envp) {
if ((envp_str = virArgvToString(envp)) == NULL) {
VIR_FREE(argv_str);
virReportOOMError();
return -1;
}
VIR_DEBUG("%s %s", envp_str, argv_str);
VIR_FREE(envp_str);
} else {
VIR_DEBUG("%s", argv_str);
}
VIR_FREE(argv_str);
if (argv[0][0] != '/') {
if (!(binary = virFindFileInPath(argv[0]))) {
virReportSystemError(ENOENT,
_("Cannot find '%s' in path"),
argv[0]);
return -1;
}
} else {
binary = argv[0];
}
if ((null = open("/dev/null", O_RDWR)) < 0) {
virReportSystemError(errno,
_("cannot open %s"),
"/dev/null");
goto cleanup;
}
if (outfd != NULL) {
if (*outfd == -1) {
if (pipe(pipeout) < 0) {
virReportSystemError(errno,
"%s", _("cannot create pipe"));
goto cleanup;
}
if ((flags & VIR_EXEC_NONBLOCK) &&
virSetNonBlock(pipeout[0]) == -1) {
virReportSystemError(errno,
"%s", _("Failed to set non-blocking file descriptor flag"));
goto cleanup;
}
if (virSetCloseExec(pipeout[0]) == -1) {
virReportSystemError(errno,
"%s", _("Failed to set close-on-exec file descriptor flag"));
goto cleanup;
}
childout = pipeout[1];
} else {
childout = *outfd;
}
} else {
childout = null;
}
if (errfd != NULL) {
if (*errfd == -1) {
if (pipe(pipeerr) < 0) {
virReportSystemError(errno,
"%s", _("Failed to create pipe"));
goto cleanup;
}
if ((flags & VIR_EXEC_NONBLOCK) &&
virSetNonBlock(pipeerr[0]) == -1) {
virReportSystemError(errno,
"%s", _("Failed to set non-blocking file descriptor flag"));
goto cleanup;
}
if (virSetCloseExec(pipeerr[0]) == -1) {
virReportSystemError(errno,
"%s", _("Failed to set close-on-exec file descriptor flag"));
goto cleanup;
}
childerr = pipeerr[1];
} else {
childerr = *errfd;
}
} else {
childerr = null;
}
forkRet = virFork(&pid);
if (pid < 0) {
goto cleanup;
}
if (pid) { /* parent */
VIR_FORCE_CLOSE(null);
if (outfd && *outfd == -1) {
VIR_FORCE_CLOSE(pipeout[1]);
*outfd = pipeout[0];
}
if (errfd && *errfd == -1) {
VIR_FORCE_CLOSE(pipeerr[1]);
*errfd = pipeerr[0];
}
if (forkRet < 0) {
goto cleanup;
}
*retpid = pid;
if (binary != argv[0])
VIR_FREE(binary);
return 0;
}
/* child */
if (forkRet < 0) {
/* The fork was successful, but after that there was an error
* in the child (which was already logged).
*/
goto fork_error;
}
openmax = sysconf(_SC_OPEN_MAX);
for (i = 3; i < openmax; i++)
if (i != infd &&
i != null &&
i != childout &&
i != childerr &&
(!keepfd || i >= FD_SETSIZE || !FD_ISSET(i, keepfd))) {
tmpfd = i;
VIR_FORCE_CLOSE(tmpfd);
}
if (dup2(infd >= 0 ? infd : null, STDIN_FILENO) < 0) {
virReportSystemError(errno,
"%s", _("failed to setup stdin file handle"));
goto fork_error;
}
if (childout > 0 &&
dup2(childout, STDOUT_FILENO) < 0) {
virReportSystemError(errno,
"%s", _("failed to setup stdout file handle"));
goto fork_error;
}
if (childerr > 0 &&
dup2(childerr, STDERR_FILENO) < 0) {
virReportSystemError(errno,
"%s", _("failed to setup stderr file handle"));
goto fork_error;
}
if (infd != STDIN_FILENO)
VIR_FORCE_CLOSE(infd);
VIR_FORCE_CLOSE(null);
if (childout > STDERR_FILENO) {
tmpfd = childout; /* preserve childout value */
VIR_FORCE_CLOSE(tmpfd);
}
if (childerr > STDERR_FILENO &&
childerr != childout) {
VIR_FORCE_CLOSE(childerr);
}
/* Initialize full logging for a while */
virLogSetFromEnv();
/* Daemonize as late as possible, so the parent process can detect
* the above errors with wait* */
if (flags & VIR_EXEC_DAEMON) {
if (setsid() < 0) {
virReportSystemError(errno,
"%s", _("cannot become session leader"));
goto fork_error;
}
if (chdir("/") < 0) {
virReportSystemError(errno,
"%s", _("cannot change to root directory"));
goto fork_error;
}
pid = fork();
if (pid < 0) {
virReportSystemError(errno,
"%s", _("cannot fork child process"));
goto fork_error;
}
if (pid > 0) {
if (pidfile && virFileWritePidPath(pidfile,pid)) {
kill(pid, SIGTERM);
usleep(500*1000);
kill(pid, SIGTERM);
virReportSystemError(errno,
_("could not write pidfile %s for %d"),
pidfile, pid);
goto fork_error;
}
_exit(0);
}
}
if (hook) {
/* virFork reset all signal handlers to the defaults.
* This is good for the child process, but our hook
* risks running something that generates SIGPIPE,
* so we need to temporarily block that again
*/
struct sigaction waxon, waxoff;
waxoff.sa_handler = SIG_IGN;
waxoff.sa_flags = 0;
sigemptyset(&waxoff.sa_mask);
memset(&waxon, 0, sizeof(waxon));
if (sigaction(SIGPIPE, &waxoff, &waxon) < 0) {
virReportSystemError(errno, "%s",
_("Could not disable SIGPIPE"));
goto fork_error;
}
if ((hook)(data) != 0) {
VIR_DEBUG("Hook function failed.");
goto fork_error;
}
if (sigaction(SIGPIPE, &waxon, NULL) < 0) {
virReportSystemError(errno, "%s",
_("Could not re-enable SIGPIPE"));
goto fork_error;
}
}
/* The steps above may need todo something privileged, so
* we delay clearing capabilities until the last minute */
if ((flags & VIR_EXEC_CLEAR_CAPS) &&
virClearCapabilities() < 0)
goto fork_error;
/* Close logging again to ensure no FDs leak to child */
virLogReset();
if (envp)
execve(binary, (char **) argv, (char**)envp);
else
execv(binary, (char **) argv);
virReportSystemError(errno,
_("cannot execute binary %s"),
argv[0]);
fork_error:
virDispatchError(NULL);
_exit(EXIT_FAILURE);
cleanup:
/* This is cleanup of parent process only - child
should never jump here on error */
if (binary != argv[0])
VIR_FREE(binary);
/* NB we don't virCommandError() on any failures here
because the code which jumped hre already raised
an error condition which we must not overwrite */
VIR_FORCE_CLOSE(pipeerr[0]);
VIR_FORCE_CLOSE(pipeerr[1]);
VIR_FORCE_CLOSE(pipeout[0]);
VIR_FORCE_CLOSE(pipeout[1]);
VIR_FORCE_CLOSE(null);
return -1;
}
/**
* @argv NULL terminated argv to run
* @status optional variable to return exit status in
*
* Run a command without using the shell.
*
* If status is NULL, then return 0 if the command run and
* exited with 0 status; Otherwise return -1
*
* If status is not-NULL, then return 0 if the command ran.
* The status variable is filled with the command exit status
* and should be checked by caller for success. Return -1
* only if the command could not be run.
*/
int
virRun(const char *const*argv, int *status)
{
int ret;
virCommandPtr cmd = virCommandNewArgs(argv);
ret = virCommandRun(cmd, status);
virCommandFree(cmd);
return ret;
}
#else /* WIN32 */
int
virRun(const char *const *argv ATTRIBUTE_UNUSED,
int *status)
{
if (status)
*status = ENOTSUP;
else
virCommandError(VIR_ERR_INTERNAL_ERROR,
"%s", _("virRun is not implemented for WIN32"));
return -1;
}
static int
virExecWithHook(const char *const*argv ATTRIBUTE_UNUSED,
const char *const*envp ATTRIBUTE_UNUSED,
const fd_set *keepfd ATTRIBUTE_UNUSED,
pid_t *retpid ATTRIBUTE_UNUSED,
int infd ATTRIBUTE_UNUSED,
int *outfd ATTRIBUTE_UNUSED,
int *errfd ATTRIBUTE_UNUSED,
int flags ATTRIBUTE_UNUSED,
virExecHook hook ATTRIBUTE_UNUSED,
void *data ATTRIBUTE_UNUSED,
char *pidfile ATTRIBUTE_UNUSED)
{
/* XXX: Some day we can implement pieces of virCommand/virExec on
* top of _spawn() or CreateProcess(), but we can't implement
* everything, since mingw completely lacks fork(), so we cannot
* run hook code in the child. */
virCommandError(VIR_ERR_INTERNAL_ERROR,
"%s", _("virExec is not implemented for WIN32"));
return -1;
}
int
virFork(pid_t *pid)
{
*pid = -1;
errno = ENOTSUP;
return -1;
}
#endif /* WIN32 */
/*
* Create a new command for named binary
*/

View File

@ -29,6 +29,20 @@
typedef struct _virCommand virCommand;
typedef virCommand *virCommandPtr;
/* This will execute in the context of the first child
* after fork() but before execve() */
typedef int (*virExecHook)(void *data);
/*
* Fork wrapper with extra error checking
*/
int virFork(pid_t *pid) ATTRIBUTE_RETURN_CHECK;
/*
* Simple synchronous command wrapper
*/
int virRun(const char *const*argv, int *status) ATTRIBUTE_RETURN_CHECK;
/*
* Create a new command for named binary
*/

View File

@ -41,7 +41,7 @@
#include "internal.h"
#include "ebtables.h"
#include "util.h"
#include "command.h"
#include "memory.h"
#include "virterror_internal.h"
#include "logging.h"

View File

@ -35,7 +35,7 @@
#include "logging.h"
#include "memory.h"
#include "util.h"
#include "command.h"
#include "virterror_internal.h"
#include "files.h"

View File

@ -34,8 +34,8 @@
#include <errno.h>
#include <poll.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/time.h>
@ -69,7 +69,6 @@
#include "virterror_internal.h"
#include "logging.h"
#include "event.h"
#include "ignore-value.h"
#include "buf.h"
#include "util.h"
#include "memory.h"
@ -247,20 +246,6 @@ virArgvToString(const char *const *argv)
return ret;
}
int virSetBlocking(int fd, bool blocking) {
return set_nonblocking_flag (fd, !blocking);
}
int virSetNonBlock(int fd) {
return virSetBlocking(fd, false);
}
int virSetCloseExec(int fd)
{
return virSetInherit(fd, false);
}
#ifndef WIN32
int virSetInherit(int fd, bool inherit) {
@ -276,507 +261,6 @@ int virSetInherit(int fd, bool inherit) {
return 0;
}
# if HAVE_CAPNG
static int virClearCapabilities(void)
{
int ret;
capng_clear(CAPNG_SELECT_BOTH);
if ((ret = capng_apply(CAPNG_SELECT_BOTH)) < 0) {
virUtilError(VIR_ERR_INTERNAL_ERROR,
_("cannot clear process capabilities %d"), ret);
return -1;
}
return 0;
}
# else
static int virClearCapabilities(void)
{
// VIR_WARN("libcap-ng support not compiled in, unable to clear capabilities");
return 0;
}
# endif
/* virFork() - fork a new process while avoiding various race/deadlock conditions
@pid - a pointer to a pid_t that will receive the return value from
fork()
on return from virFork(), if *pid < 0, the fork failed and there is
no new process. Otherwise, just like fork(), if *pid == 0, it is the
child process returning, and if *pid > 0, it is the parent.
Even if *pid >= 0, if the return value from virFork() is < 0, it
indicates a failure that occurred in the parent or child process
after the fork. In this case, the child process should call
_exit(EXIT_FAILURE) after doing any additional error reporting.
*/
int virFork(pid_t *pid) {
# ifdef HAVE_PTHREAD_SIGMASK
sigset_t oldmask, newmask;
# endif
struct sigaction sig_action;
int saved_errno, ret = -1;
*pid = -1;
/*
* Need to block signals now, so that child process can safely
* kill off caller's signal handlers without a race.
*/
# ifdef HAVE_PTHREAD_SIGMASK
sigfillset(&newmask);
if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) {
saved_errno = errno;
virReportSystemError(errno,
"%s", _("cannot block signals"));
goto cleanup;
}
# endif
/* Ensure we hold the logging lock, to protect child processes
* from deadlocking on another thread's inherited mutex state */
virLogLock();
*pid = fork();
saved_errno = errno; /* save for caller */
/* Unlock for both parent and child process */
virLogUnlock();
if (*pid < 0) {
# ifdef HAVE_PTHREAD_SIGMASK
/* attempt to restore signal mask, but ignore failure, to
avoid obscuring the fork failure */
ignore_value (pthread_sigmask(SIG_SETMASK, &oldmask, NULL));
# endif
virReportSystemError(saved_errno,
"%s", _("cannot fork child process"));
goto cleanup;
}
if (*pid) {
/* parent process */
# ifdef HAVE_PTHREAD_SIGMASK
/* Restore our original signal mask now that the child is
safely running */
if (pthread_sigmask(SIG_SETMASK, &oldmask, NULL) != 0) {
saved_errno = errno; /* save for caller */
virReportSystemError(errno, "%s", _("cannot unblock signals"));
goto cleanup;
}
# endif
ret = 0;
} else {
/* child process */
int logprio;
int i;
/* Remove any error callback so errors in child now
get sent to stderr where they stand a fighting chance
of being seen / logged */
virSetErrorFunc(NULL, NULL);
virSetErrorLogPriorityFunc(NULL);
/* Make sure any hook logging is sent to stderr, since child
* process may close the logfile FDs */
logprio = virLogGetDefaultPriority();
virLogReset();
virLogSetDefaultPriority(logprio);
/* Clear out all signal handlers from parent so nothing
unexpected can happen in our child once we unblock
signals */
sig_action.sa_handler = SIG_DFL;
sig_action.sa_flags = 0;
sigemptyset(&sig_action.sa_mask);
for (i = 1; i < NSIG; i++) {
/* Only possible errors are EFAULT or EINVAL
The former wont happen, the latter we
expect, so no need to check return value */
sigaction(i, &sig_action, NULL);
}
# ifdef HAVE_PTHREAD_SIGMASK
/* Unmask all signals in child, since we've no idea
what the caller's done with their signal mask
and don't want to propagate that to children */
sigemptyset(&newmask);
if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) {
saved_errno = errno; /* save for caller */
virReportSystemError(errno, "%s", _("cannot unblock signals"));
goto cleanup;
}
# endif
ret = 0;
}
cleanup:
if (ret < 0)
errno = saved_errno;
return ret;
}
/*
* @argv argv to exec
* @envp optional environment to use for exec
* @keepfd options fd_ret to keep open for child process
* @retpid optional pointer to store child process pid
* @infd optional file descriptor to use as child input, otherwise /dev/null
* @outfd optional pointer to communicate output fd behavior
* outfd == NULL : Use /dev/null
* *outfd == -1 : Use a new fd
* *outfd != -1 : Use *outfd
* @errfd optional pointer to communcate error fd behavior. See outfd
* @flags possible combination of the following:
* VIR_EXEC_NONE : Default function behavior
* VIR_EXEC_NONBLOCK : Set child process output fd's as non-blocking
* VIR_EXEC_DAEMON : Daemonize the child process
* @hook optional virExecHook function to call prior to exec
* @data data to pass to the hook function
* @pidfile path to use as pidfile for daemonized process (needs DAEMON flag)
*/
int
virExecWithHook(const char *const*argv,
const char *const*envp,
const fd_set *keepfd,
pid_t *retpid,
int infd, int *outfd, int *errfd,
int flags,
virExecHook hook,
void *data,
char *pidfile)
{
pid_t pid;
int null, i, openmax;
int pipeout[2] = {-1,-1};
int pipeerr[2] = {-1,-1};
int childout = -1;
int childerr = -1;
int tmpfd;
const char *binary = NULL;
int forkRet;
char *argv_str = NULL;
char *envp_str = NULL;
if ((argv_str = virArgvToString(argv)) == NULL) {
virReportOOMError();
return -1;
}
if (envp) {
if ((envp_str = virArgvToString(envp)) == NULL) {
VIR_FREE(argv_str);
virReportOOMError();
return -1;
}
VIR_DEBUG("%s %s", envp_str, argv_str);
VIR_FREE(envp_str);
} else {
VIR_DEBUG("%s", argv_str);
}
VIR_FREE(argv_str);
if (argv[0][0] != '/') {
if (!(binary = virFindFileInPath(argv[0]))) {
virReportSystemError(ENOENT,
_("Cannot find '%s' in path"),
argv[0]);
return -1;
}
} else {
binary = argv[0];
}
if ((null = open("/dev/null", O_RDWR)) < 0) {
virReportSystemError(errno,
_("cannot open %s"),
"/dev/null");
goto cleanup;
}
if (outfd != NULL) {
if (*outfd == -1) {
if (pipe(pipeout) < 0) {
virReportSystemError(errno,
"%s", _("cannot create pipe"));
goto cleanup;
}
if ((flags & VIR_EXEC_NONBLOCK) &&
virSetNonBlock(pipeout[0]) == -1) {
virReportSystemError(errno,
"%s", _("Failed to set non-blocking file descriptor flag"));
goto cleanup;
}
if (virSetCloseExec(pipeout[0]) == -1) {
virReportSystemError(errno,
"%s", _("Failed to set close-on-exec file descriptor flag"));
goto cleanup;
}
childout = pipeout[1];
} else {
childout = *outfd;
}
} else {
childout = null;
}
if (errfd != NULL) {
if (*errfd == -1) {
if (pipe(pipeerr) < 0) {
virReportSystemError(errno,
"%s", _("Failed to create pipe"));
goto cleanup;
}
if ((flags & VIR_EXEC_NONBLOCK) &&
virSetNonBlock(pipeerr[0]) == -1) {
virReportSystemError(errno,
"%s", _("Failed to set non-blocking file descriptor flag"));
goto cleanup;
}
if (virSetCloseExec(pipeerr[0]) == -1) {
virReportSystemError(errno,
"%s", _("Failed to set close-on-exec file descriptor flag"));
goto cleanup;
}
childerr = pipeerr[1];
} else {
childerr = *errfd;
}
} else {
childerr = null;
}
forkRet = virFork(&pid);
if (pid < 0) {
goto cleanup;
}
if (pid) { /* parent */
VIR_FORCE_CLOSE(null);
if (outfd && *outfd == -1) {
VIR_FORCE_CLOSE(pipeout[1]);
*outfd = pipeout[0];
}
if (errfd && *errfd == -1) {
VIR_FORCE_CLOSE(pipeerr[1]);
*errfd = pipeerr[0];
}
if (forkRet < 0) {
goto cleanup;
}
*retpid = pid;
if (binary != argv[0])
VIR_FREE(binary);
return 0;
}
/* child */
if (forkRet < 0) {
/* The fork was sucessful, but after that there was an error
* in the child (which was already logged).
*/
goto fork_error;
}
openmax = sysconf(_SC_OPEN_MAX);
for (i = 3; i < openmax; i++)
if (i != infd &&
i != null &&
i != childout &&
i != childerr &&
(!keepfd || i >= FD_SETSIZE || !FD_ISSET(i, keepfd))) {
tmpfd = i;
VIR_FORCE_CLOSE(tmpfd);
}
if (dup2(infd >= 0 ? infd : null, STDIN_FILENO) < 0) {
virReportSystemError(errno,
"%s", _("failed to setup stdin file handle"));
goto fork_error;
}
if (childout > 0 &&
dup2(childout, STDOUT_FILENO) < 0) {
virReportSystemError(errno,
"%s", _("failed to setup stdout file handle"));
goto fork_error;
}
if (childerr > 0 &&
dup2(childerr, STDERR_FILENO) < 0) {
virReportSystemError(errno,
"%s", _("failed to setup stderr file handle"));
goto fork_error;
}
if (infd != STDIN_FILENO)
VIR_FORCE_CLOSE(infd);
VIR_FORCE_CLOSE(null);
if (childout > STDERR_FILENO) {
tmpfd = childout; /* preserve childout value */
VIR_FORCE_CLOSE(tmpfd);
}
if (childerr > STDERR_FILENO &&
childerr != childout) {
VIR_FORCE_CLOSE(childerr);
}
/* Initialize full logging for a while */
virLogSetFromEnv();
/* Daemonize as late as possible, so the parent process can detect
* the above errors with wait* */
if (flags & VIR_EXEC_DAEMON) {
if (setsid() < 0) {
virReportSystemError(errno,
"%s", _("cannot become session leader"));
goto fork_error;
}
if (chdir("/") < 0) {
virReportSystemError(errno,
"%s", _("cannot change to root directory"));
goto fork_error;
}
pid = fork();
if (pid < 0) {
virReportSystemError(errno,
"%s", _("cannot fork child process"));
goto fork_error;
}
if (pid > 0) {
if (pidfile && virFileWritePidPath(pidfile,pid)) {
kill(pid, SIGTERM);
usleep(500*1000);
kill(pid, SIGTERM);
virReportSystemError(errno,
_("could not write pidfile %s for %d"),
pidfile, pid);
goto fork_error;
}
_exit(0);
}
}
if (hook) {
/* virFork reset all signal handlers to the defaults.
* This is good for the child process, but our hook
* risks running something that generates SIGPIPE,
* so we need to temporarily block that again
*/
struct sigaction waxon, waxoff;
waxoff.sa_handler = SIG_IGN;
waxoff.sa_flags = 0;
sigemptyset(&waxoff.sa_mask);
memset(&waxon, 0, sizeof(waxon));
if (sigaction(SIGPIPE, &waxoff, &waxon) < 0) {
virReportSystemError(errno, "%s",
_("Could not disable SIGPIPE"));
goto fork_error;
}
if ((hook)(data) != 0) {
VIR_DEBUG("Hook function failed.");
goto fork_error;
}
if (sigaction(SIGPIPE, &waxon, NULL) < 0) {
virReportSystemError(errno, "%s",
_("Could not re-enable SIGPIPE"));
goto fork_error;
}
}
/* The steps above may need todo something privileged, so
* we delay clearing capabilities until the last minute */
if ((flags & VIR_EXEC_CLEAR_CAPS) &&
virClearCapabilities() < 0)
goto fork_error;
/* Close logging again to ensure no FDs leak to child */
virLogReset();
if (envp)
execve(binary, (char **) argv, (char**)envp);
else
execv(binary, (char **) argv);
virReportSystemError(errno,
_("cannot execute binary %s"),
argv[0]);
fork_error:
virDispatchError(NULL);
_exit(EXIT_FAILURE);
cleanup:
/* This is cleanup of parent process only - child
should never jump here on error */
if (binary != argv[0])
VIR_FREE(binary);
/* NB we don't virUtilError() on any failures here
because the code which jumped hre already raised
an error condition which we must not overwrite */
VIR_FORCE_CLOSE(pipeerr[0]);
VIR_FORCE_CLOSE(pipeerr[1]);
VIR_FORCE_CLOSE(pipeout[0]);
VIR_FORCE_CLOSE(pipeout[1]);
VIR_FORCE_CLOSE(null);
return -1;
}
/**
* @argv NULL terminated argv to run
* @status optional variable to return exit status in
*
* Run a command without using the shell.
*
* If status is NULL, then return 0 if the command run and
* exited with 0 status; Otherwise return -1
*
* If status is not-NULL, then return 0 if the command ran.
* The status variable is filled with the command exit status
* and should be checked by caller for success. Return -1
* only if the command could not be run.
*/
int
virRun(const char *const*argv, int *status)
{
int ret;
virCommandPtr cmd = virCommandNewArgs(argv);
ret = virCommandRun(cmd, status);
virCommandFree(cmd);
return ret;
}
#else /* WIN32 */
int virSetInherit(int fd ATTRIBUTE_UNUSED, bool inherit ATTRIBUTE_UNUSED)
@ -784,51 +268,21 @@ int virSetInherit(int fd ATTRIBUTE_UNUSED, bool inherit ATTRIBUTE_UNUSED)
return -1;
}
int
virRun(const char *const *argv ATTRIBUTE_UNUSED,
int *status)
{
if (status)
*status = ENOTSUP;
else
virUtilError(VIR_ERR_INTERNAL_ERROR,
"%s", _("virRun is not implemented for WIN32"));
return -1;
}
int
virExecWithHook(const char *const*argv ATTRIBUTE_UNUSED,
const char *const*envp ATTRIBUTE_UNUSED,
const fd_set *keepfd ATTRIBUTE_UNUSED,
pid_t *retpid ATTRIBUTE_UNUSED,
int infd ATTRIBUTE_UNUSED,
int *outfd ATTRIBUTE_UNUSED,
int *errfd ATTRIBUTE_UNUSED,
int flags ATTRIBUTE_UNUSED,
virExecHook hook ATTRIBUTE_UNUSED,
void *data ATTRIBUTE_UNUSED,
char *pidfile ATTRIBUTE_UNUSED)
{
/* XXX: Some day we can implement pieces of virCommand/virExec on
* top of _spawn() or CreateProcess(), but we can't implement
* everything, since mingw completely lacks fork(), so we cannot
* run hook code in the child. */
virUtilError(VIR_ERR_INTERNAL_ERROR,
"%s", _("virExec is not implemented for WIN32"));
return -1;
}
int
virFork(pid_t *pid)
{
*pid = -1;
errno = ENOTSUP;
return -1;
}
#endif /* WIN32 */
int virSetBlocking(int fd, bool blocking) {
return set_nonblocking_flag (fd, !blocking);
}
int virSetNonBlock(int fd) {
return virSetBlocking(fd, false);
}
int virSetCloseExec(int fd)
{
return virSetInherit(fd, false);
}
int
virPipeReadUntilEOF(int outfd, int errfd,
char **outbuf, char **errbuf) {

View File

@ -42,37 +42,13 @@ ssize_t safewrite(int fd, const void *buf, size_t count)
int safezero(int fd, int flags, off_t offset, off_t len)
ATTRIBUTE_RETURN_CHECK;
enum {
VIR_EXEC_NONE = 0,
VIR_EXEC_NONBLOCK = (1 << 0),
VIR_EXEC_DAEMON = (1 << 1),
VIR_EXEC_CLEAR_CAPS = (1 << 2),
};
int virSetBlocking(int fd, bool blocking) ATTRIBUTE_RETURN_CHECK;
int virSetNonBlock(int fd) ATTRIBUTE_RETURN_CHECK;
int virSetInherit(int fd, bool inherit) ATTRIBUTE_RETURN_CHECK;
int virSetCloseExec(int fd) ATTRIBUTE_RETURN_CHECK;
/* This will execute in the context of the first child
* after fork() but before execve() */
typedef int (*virExecHook)(void *data);
int virExecWithHook(const char *const*argv,
const char *const*envp,
const fd_set *keepfd,
pid_t *retpid,
int infd,
int *outfd,
int *errfd,
int flags,
virExecHook hook,
void *data,
char *pidfile) ATTRIBUTE_RETURN_CHECK;
int virRun(const char *const*argv, int *status) ATTRIBUTE_RETURN_CHECK;
int virPipeReadUntilEOF(int outfd, int errfd,
char **outbuf, char **errbuf);
int virFork(pid_t *pid);
int virSetUIDGID(uid_t uid, gid_t gid);

View File

@ -29,6 +29,7 @@
#include "files.h"
#include "memory.h"
#include "uuid.h"
#include "command.h"
#include "vmx.h"
#include "vmware_conf.h"
#include "vmware_driver.h"