#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <linux/string.h>
#include <errno.h>
#include <sys/wait.h>
#include "subcmd-util.h"
#include "run-command.h"
#include "exec-cmd.h"

#define STRERR_BUFSIZE 128

static inline void close_pair(int fd[2])
{
	close(fd[0]);
	close(fd[1]);
}

static inline void dup_devnull(int to)
{
	int fd = open("/dev/null", O_RDWR);
	dup2(fd, to);
	close(fd);
}

int start_command(struct child_process *cmd)
{
	int need_in, need_out, need_err;
	int fdin[2], fdout[2], fderr[2];
	char sbuf[STRERR_BUFSIZE];

	/*
	 * In case of errors we must keep the promise to close FDs
	 * that have been passed in via ->in and ->out.
	 */

	need_in = !cmd->no_stdin && cmd->in < 0;
	if (need_in) {
		if (pipe(fdin) < 0) {
			if (cmd->out > 0)
				close(cmd->out);
			return -ERR_RUN_COMMAND_PIPE;
		}
		cmd->in = fdin[1];
	}

	need_out = !cmd->no_stdout
		&& !cmd->stdout_to_stderr
		&& cmd->out < 0;
	if (need_out) {
		if (pipe(fdout) < 0) {
			if (need_in)
				close_pair(fdin);
			else if (cmd->in)
				close(cmd->in);
			return -ERR_RUN_COMMAND_PIPE;
		}
		cmd->out = fdout[0];
	}

	need_err = !cmd->no_stderr && cmd->err < 0;
	if (need_err) {
		if (pipe(fderr) < 0) {
			if (need_in)
				close_pair(fdin);
			else if (cmd->in)
				close(cmd->in);
			if (need_out)
				close_pair(fdout);
			else if (cmd->out)
				close(cmd->out);
			return -ERR_RUN_COMMAND_PIPE;
		}
		cmd->err = fderr[0];
	}

	fflush(NULL);
	cmd->pid = fork();
	if (!cmd->pid) {
		if (cmd->no_stdin)
			dup_devnull(0);
		else if (need_in) {
			dup2(fdin[0], 0);
			close_pair(fdin);
		} else if (cmd->in) {
			dup2(cmd->in, 0);
			close(cmd->in);
		}

		if (cmd->no_stderr)
			dup_devnull(2);
		else if (need_err) {
			dup2(fderr[1], 2);
			close_pair(fderr);
		}

		if (cmd->no_stdout)
			dup_devnull(1);
		else if (cmd->stdout_to_stderr)
			dup2(2, 1);
		else if (need_out) {
			dup2(fdout[1], 1);
			close_pair(fdout);
		} else if (cmd->out > 1) {
			dup2(cmd->out, 1);
			close(cmd->out);
		}

		if (cmd->dir && chdir(cmd->dir))
			die("exec %s: cd to %s failed (%s)", cmd->argv[0],
			    cmd->dir, str_error_r(errno, sbuf, sizeof(sbuf)));
		if (cmd->env) {
			for (; *cmd->env; cmd->env++) {
				if (strchr(*cmd->env, '='))
					putenv((char*)*cmd->env);
				else
					unsetenv(*cmd->env);
			}
		}
		if (cmd->preexec_cb)
			cmd->preexec_cb();
		if (cmd->exec_cmd) {
			execv_cmd(cmd->argv);
		} else {
			execvp(cmd->argv[0], (char *const*) cmd->argv);
		}
		exit(127);
	}

	if (cmd->pid < 0) {
		int err = errno;
		if (need_in)
			close_pair(fdin);
		else if (cmd->in)
			close(cmd->in);
		if (need_out)
			close_pair(fdout);
		else if (cmd->out)
			close(cmd->out);
		if (need_err)
			close_pair(fderr);
		return err == ENOENT ?
			-ERR_RUN_COMMAND_EXEC :
			-ERR_RUN_COMMAND_FORK;
	}

	if (need_in)
		close(fdin[0]);
	else if (cmd->in)
		close(cmd->in);

	if (need_out)
		close(fdout[1]);
	else if (cmd->out)
		close(cmd->out);

	if (need_err)
		close(fderr[1]);

	return 0;
}

static int wait_or_whine(pid_t pid)
{
	char sbuf[STRERR_BUFSIZE];

	for (;;) {
		int status, code;
		pid_t waiting = waitpid(pid, &status, 0);

		if (waiting < 0) {
			if (errno == EINTR)
				continue;
			fprintf(stderr, " Error: waitpid failed (%s)",
				str_error_r(errno, sbuf, sizeof(sbuf)));
			return -ERR_RUN_COMMAND_WAITPID;
		}
		if (waiting != pid)
			return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
		if (WIFSIGNALED(status))
			return -ERR_RUN_COMMAND_WAITPID_SIGNAL;

		if (!WIFEXITED(status))
			return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
		code = WEXITSTATUS(status);
		switch (code) {
		case 127:
			return -ERR_RUN_COMMAND_EXEC;
		case 0:
			return 0;
		default:
			return -code;
		}
	}
}

int finish_command(struct child_process *cmd)
{
	return wait_or_whine(cmd->pid);
}

int run_command(struct child_process *cmd)
{
	int code = start_command(cmd);
	if (code)
		return code;
	return finish_command(cmd);
}

static void prepare_run_command_v_opt(struct child_process *cmd,
				      const char **argv,
				      int opt)
{
	memset(cmd, 0, sizeof(*cmd));
	cmd->argv = argv;
	cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
	cmd->exec_cmd = opt & RUN_EXEC_CMD ? 1 : 0;
	cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
}

int run_command_v_opt(const char **argv, int opt)
{
	struct child_process cmd;
	prepare_run_command_v_opt(&cmd, argv, opt);
	return run_command(&cmd);
}
le></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Feng &lt;fgao@ikuai8.com&gt;</td><td class='right'>2017-01-20 21:40:43 +0800</td></tr>
<tr><th>committer</th><td>Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;</td><td class='right'>2017-02-02 14:30:19 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/mac802154/rx.c?id=10435c1192d06bdb0bac7666452d8219d7e7c477'>10435c1192d06bdb0bac7666452d8219d7e7c477</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/mac802154/rx.c?id=10435c1192d06bdb0bac7666452d8219d7e7c477'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=10435c1192d06bdb0bac7666452d8219d7e7c477'>93b76419142fe17b1d162d062c663297a3e8a965</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/mac802154/rx.c?id=10435c1192d06bdb0bac7666452d8219d7e7c477'>net/mac802154/rx.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/mac802154/rx.c?id=1a28ad74ebd8f9d3c7eae0d781f72a6d30545e17'>1a28ad74ebd8f9d3c7eae0d781f72a6d30545e17</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/mac802154/rx.c?id=10435c1192d06bdb0bac7666452d8219d7e7c477&amp;id2=1a28ad74ebd8f9d3c7eae0d781f72a6d30545e17'>diff</a>)</td></tr></table>
<div class='commit-subject'>netfilter: nf_tables: Eliminate duplicated code in nf_tables_table_enable()</div><div class='commit-msg'>If something fails in nf_tables_table_enable(), it unregisters the
chains. But the rollback code is the same as nf_tables_table_disable()
almostly, except there is one counter check.  Now create one wrapper
function to eliminate the duplicated codes.

Signed-off-by: Feng &lt;fgao@ikuai8.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=10435c1192d06bdb0bac7666452d8219d7e7c477'>Diffstat</a> (limited to 'net/mac802154/rx.c')</div><table summary='diffstat' class='diffstat'>