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/*
* Process management
* Copyright Jan Engelhardt, 2008-2009
*
* This file is part of libHX. libHX 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 or (at your option) any later version.
*/
#include "config.h"
#include "internal.h"
#if !defined(HAVE_FORK) || !defined(HAVE_PIPE) || !defined(HAVE_EXECV) || \
!defined(HAVE_EXECVP)
#include <errno.h>
#include <libHX/proc.h>
struct HXproc;
EXPORT_SYMBOL int HXproc_run_async(const char *const *argv, struct HXproc *p)
{
return -ENOSYS;
}
EXPORT_SYMBOL int HXproc_run_sync(const char *const *argv, unsigned int flags)
{
/* Might use system() here... */
return -ENOSYS;
}
EXPORT_SYMBOL int HXproc_wait(struct HXproc *p)
{
return -ENOSYS;
}
#else /* HAVE_FORK, HAVE_PIPE, HAVE_EXECVE */
#include <sys/wait.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <libHX/defs.h>
#include <libHX/proc.h>
#include "internal.h"
#ifdef _WIN32
# define NULL_DEVICE "nul"
#else
# define NULL_DEVICE "/dev/null"
#endif
/**
* HXproc_build_pipes -
* @fd_request: user array to tell us which pipe sets to create
* @p: result array
*
* Create some pipes.
* Explicitly initialize the @p array with -1 so that we can call close()
* on all of them without any side effects.
*/
static __inline__ int
HXproc_build_pipes(const struct HXproc *proc, int (*p)[2])
{
unsigned int x, y;
for (x = 0; x < 3; ++x)
for (y = 0; y < 2; ++y)
p[x][y] = -1;
if ((proc->p_flags & HXPROC_STDIN) && pipe(p[0]) < 0)
return -errno;
if ((proc->p_flags & HXPROC_STDOUT) && pipe(p[1]) < 0)
return -errno;
if ((proc->p_flags & HXPROC_STDERR) && pipe(p[2]) < 0)
return -errno;
return 1;
}
/**
* HXproc_close_pipes -
* @p: pipe fds to close
*
* In @p, there might be some fds that are -1 (due to the p[x][y] = -1 in
* HXproc_build_pipes()). That is ok, as closing -1 does not do anything.
*/
static void HXproc_close_pipes(int (*p)[2])
{
if (p[0][0] >= 0)
close(p[0][0]);
if (p[0][1] >= 0)
close(p[0][1]);
if (p[1][0] >= 0)
close(p[1][0]);
if (p[1][1] >= 0)
close(p[1][1]);
if (p[2][0] >= 0)
close(p[2][0]);
if (p[2][1] >= 0)
close(p[2][1]);
}
/**
* HXproc_run_async -
* @argv: program and arguments
* @proc: control block with flags, also used to return info like fds
*
* Sets up pipes and runs the specified program.
*/
EXPORT_SYMBOL int
HXproc_run_async(const char *const *argv, struct HXproc *proc)
{
int pipes[3][2], nullfd = -1, ret, saved_errno;
unsigned int t;
if (argv == NULL || *argv == NULL)
return -EFAULT;
proc->p_stdin = proc->p_stdout = proc->p_stderr = -1;
t = (proc->p_flags & (HXPROC_STDIN | HXPROC_NULL_STDIN)) ==
(HXPROC_STDIN | HXPROC_NULL_STDIN);
t |= (proc->p_flags & (HXPROC_STDOUT | HXPROC_NULL_STDOUT)) ==
(HXPROC_STDOUT | HXPROC_NULL_STDOUT);
t |= (proc->p_flags & (HXPROC_STDERR | HXPROC_NULL_STDERR)) ==
(HXPROC_STDERR | HXPROC_NULL_STDERR);
if (t > 0)
return -EINVAL;
if (proc->p_flags & (HXPROC_NULL_STDIN | HXPROC_NULL_STDOUT |
HXPROC_NULL_STDERR)) {
if ((nullfd = open(NULL_DEVICE, O_RDWR)) < 0)
return -errno;
}
if ((ret = HXproc_build_pipes(proc, pipes)) <= 0) {
saved_errno = errno;
if (nullfd >= 0)
close(nullfd);
errno = saved_errno;
return ret;
}
if (proc->p_ops != NULL && proc->p_ops->p_prefork != NULL)
proc->p_ops->p_prefork(proc->p_data);
if ((proc->p_pid = fork()) < 0) {
saved_errno = errno;
if (proc->p_ops != NULL && proc->p_ops->p_complete != NULL)
proc->p_ops->p_complete(proc->p_data);
HXproc_close_pipes(pipes);
if (nullfd >= 0)
close(nullfd);
return -(errno = saved_errno);
} else if (proc->p_pid == 0) {
const char *prog = *argv;
/*
* Put file descriptors in place... and do so before postfork,
* as someone could have used proc.p_data = &proc; already.
*
* Take a dup of the pipe ends, so that close_pipes does not
* accidentally close them.
*/
if (proc->p_flags & HXPROC_STDIN)
proc->p_stdin = dup(pipes[0][0]);
else if (proc->p_flags & HXPROC_NULL_STDIN)
proc->p_stdin = dup(nullfd);
if (proc->p_flags & HXPROC_STDOUT)
proc->p_stdout = dup(pipes[1][1]);
else if (proc->p_flags & HXPROC_NULL_STDOUT)
proc->p_stdout = dup(nullfd);
if (proc->p_flags & HXPROC_STDERR)
proc->p_stderr = dup(pipes[2][1]);
else if (proc->p_flags & HXPROC_NULL_STDERR)
proc->p_stderr = dup(nullfd);
if (proc->p_ops != NULL && proc->p_ops->p_postfork != NULL)
proc->p_ops->p_postfork(proc->p_data);
/*
* The rest of housekeeping. Now move the pipe ends onto
* their final fds.
*/
HXproc_close_pipes(pipes);
if ((proc->p_flags & (HXPROC_STDIN | HXPROC_NULL_STDIN)) &&
proc->p_stdin != STDIN_FILENO) {
dup2(proc->p_stdin, STDIN_FILENO);
close(proc->p_stdin);
}
if ((proc->p_flags & (HXPROC_STDOUT | HXPROC_NULL_STDOUT)) &&
proc->p_stdout != STDOUT_FILENO) {
dup2(proc->p_stdout, STDOUT_FILENO);
close(proc->p_stdout);
}
if ((proc->p_flags & (HXPROC_STDERR | HXPROC_NULL_STDERR)) &&
proc->p_stderr != STDERR_FILENO) {
dup2(proc->p_stderr, STDERR_FILENO);
close(proc->p_stderr);
}
if (nullfd >= 0)
close(nullfd);
if (proc->p_flags & HXPROC_A0)
++argv;
if (proc->p_flags & HXPROC_EXECV)
execv(prog, const_cast2(char * const *, argv));
else
execvp(prog, const_cast2(char * const *, argv));
if (proc->p_flags & HXPROC_VERBOSE)
fprintf(stderr, "%s: %s: %s\n", __func__,
prog, strerror(errno));
_exit(-1);
}
if (proc->p_flags & HXPROC_STDIN) {
close(pipes[0][0]);
proc->p_stdin = pipes[0][1];
}
if (proc->p_flags & HXPROC_STDOUT) {
close(pipes[1][1]);
proc->p_stdout = pipes[1][0];
}
if (proc->p_flags & HXPROC_STDERR) {
close(pipes[2][1]);
proc->p_stderr = pipes[2][0];
}
return 1;
}
EXPORT_SYMBOL int HXproc_run_sync(const char *const *argv, unsigned int flags)
{
struct HXproc proc;
int ret;
memset(&proc, 0, sizeof(proc));
/*
* Assigning file descriptors makes no sense because they would not
* be read from. %HXPROC_NULL_* is ok of course.
*/
if (flags & (HXPROC_STDIN | HXPROC_STDOUT | HXPROC_STDERR))
return -EINVAL;
proc.p_flags = flags;
if ((ret = HXproc_run_async(argv, &proc)) <= 0)
return ret;
return HXproc_wait(&proc);
}
EXPORT_SYMBOL int HXproc_wait(struct HXproc *proc)
{
int status;
/* User has to close the pipes. Do not do it here. */
if (waitpid(proc->p_pid, &status, 0) < 0)
return -errno;
if (proc->p_ops != NULL && proc->p_ops->p_complete != NULL)
proc->p_ops->p_complete(proc->p_data);
if ((proc->p_exited = WIFEXITED(status)))
proc->p_status = WEXITSTATUS(status);
if ((proc->p_terminated = WIFSIGNALED(status)))
proc->p_status = WTERMSIG(status);
if (proc->p_terminated)
return static_cast(unsigned int,
static_cast(unsigned char, proc->p_status)) << 16;
return static_cast(unsigned char, proc->p_status);
}
#endif /* HAVE_lots */
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