[mirror_ubuntu-artful-kernel.git] / tools / lib / subcmd / run-command.c

#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);
}
Commit	Line	Data
2f4ce5ec JP	1	#include <unistd.h>
	2	#include <sys/types.h>
	3	#include <sys/stat.h>
	4	#include <fcntl.h>
	5	#include <string.h>
07eebccb	6	#include <linux/string.h>
2f4ce5ec JP	7	#include <errno.h>
	8	#include <sys/wait.h>
	9	#include "subcmd-util.h"
07800601	10	#include "run-command.h"
4b6ab94e	11	#include "exec-cmd.h"
2f4ce5ec JP	12
2f4ce5ec JP	13	#define STRERR_BUFSIZE 128
07800601 IM	14
	15	static inline void close_pair(int fd[2])
	16	{
	17	close(fd[0]);
	18	close(fd[1]);
	19	}
	20
	21	static inline void dup_devnull(int to)
	22	{
	23	int fd = open("/dev/null", O_RDWR);
	24	dup2(fd, to);
	25	close(fd);
	26	}
	27
	28	int start_command(struct child_process *cmd)
	29	{
	30	int need_in, need_out, need_err;
	31	int fdin[2], fdout[2], fderr[2];
6e81c74c	32	char sbuf[STRERR_BUFSIZE];
07800601 IM	33
	34	/*
	35	* In case of errors we must keep the promise to close FDs
	36	* that have been passed in via ->in and ->out.
	37	*/
	38
	39	need_in = !cmd->no_stdin && cmd->in < 0;
	40	if (need_in) {
	41	if (pipe(fdin) < 0) {
	42	if (cmd->out > 0)
	43	close(cmd->out);
	44	return -ERR_RUN_COMMAND_PIPE;
	45	}
	46	cmd->in = fdin[1];
	47	}
	48
	49	need_out = !cmd->no_stdout
	50	&& !cmd->stdout_to_stderr
	51	&& cmd->out < 0;
	52	if (need_out) {
	53	if (pipe(fdout) < 0) {
	54	if (need_in)
	55	close_pair(fdin);
	56	else if (cmd->in)
	57	close(cmd->in);
	58	return -ERR_RUN_COMMAND_PIPE;
	59	}
	60	cmd->out = fdout[0];
	61	}
	62
	63	need_err = !cmd->no_stderr && cmd->err < 0;
	64	if (need_err) {
	65	if (pipe(fderr) < 0) {
	66	if (need_in)
	67	close_pair(fdin);
	68	else if (cmd->in)
	69	close(cmd->in);
	70	if (need_out)
	71	close_pair(fdout);
	72	else if (cmd->out)
	73	close(cmd->out);
	74	return -ERR_RUN_COMMAND_PIPE;
	75	}
	76	cmd->err = fderr[0];
	77	}
	78
07800601 IM	79	fflush(NULL);
	80	cmd->pid = fork();
	81	if (!cmd->pid) {
	82	if (cmd->no_stdin)
	83	dup_devnull(0);
	84	else if (need_in) {
	85	dup2(fdin[0], 0);
	86	close_pair(fdin);
	87	} else if (cmd->in) {
	88	dup2(cmd->in, 0);
	89	close(cmd->in);
	90	}
	91
	92	if (cmd->no_stderr)
	93	dup_devnull(2);
	94	else if (need_err) {
	95	dup2(fderr[1], 2);
	96	close_pair(fderr);
	97	}
	98
	99	if (cmd->no_stdout)
	100	dup_devnull(1);
	101	else if (cmd->stdout_to_stderr)
	102	dup2(2, 1);
	103	else if (need_out) {
	104	dup2(fdout[1], 1);
	105	close_pair(fdout);
	106	} else if (cmd->out > 1) {
	107	dup2(cmd->out, 1);
	108	close(cmd->out);
	109	}
	110
	111	if (cmd->dir && chdir(cmd->dir))
	112	die("exec %s: cd to %s failed (%s)", cmd->argv[0],
07eebccb	113	cmd->dir, str_error_r(errno, sbuf, sizeof(sbuf)));
07800601 IM	114	if (cmd->env) {
	115	for (; *cmd->env; cmd->env++) {
	116	if (strchr(*cmd->env, '='))
	117	putenv((char)cmd->env);
	118	else
	119	unsetenv(*cmd->env);
	120	}
	121	}
	122	if (cmd->preexec_cb)
	123	cmd->preexec_cb();
46113a54 JP	124	if (cmd->exec_cmd) {
46113a54 JP	125	execv_cmd(cmd->argv);
07800601 IM	126	} else {
	127	execvp(cmd->argv[0], (char const) cmd->argv);
	128	}
	129	exit(127);
	130	}
07800601 IM	131
	132	if (cmd->pid < 0) {
	133	int err = errno;
	134	if (need_in)
	135	close_pair(fdin);
	136	else if (cmd->in)
	137	close(cmd->in);
	138	if (need_out)
	139	close_pair(fdout);
	140	else if (cmd->out)
	141	close(cmd->out);
	142	if (need_err)
	143	close_pair(fderr);
	144	return err == ENOENT ?
	145	-ERR_RUN_COMMAND_EXEC :
	146	-ERR_RUN_COMMAND_FORK;
	147	}
	148
	149	if (need_in)
	150	close(fdin[0]);
	151	else if (cmd->in)
	152	close(cmd->in);
	153
	154	if (need_out)
	155	close(fdout[1]);
	156	else if (cmd->out)
	157	close(cmd->out);
	158
	159	if (need_err)
	160	close(fderr[1]);
	161
	162	return 0;
	163	}
	164
	165	static int wait_or_whine(pid_t pid)
	166	{
6e81c74c MH	167	char sbuf[STRERR_BUFSIZE];
6e81c74c MH	168
07800601 IM	169	for (;;) {
	170	int status, code;
	171	pid_t waiting = waitpid(pid, &status, 0);
	172
	173	if (waiting < 0) {
	174	if (errno == EINTR)
	175	continue;
2f4ce5ec	176	fprintf(stderr, " Error: waitpid failed (%s)",
07eebccb	177	str_error_r(errno, sbuf, sizeof(sbuf)));
07800601 IM	178	return -ERR_RUN_COMMAND_WAITPID;
	179	}
	180	if (waiting != pid)
	181	return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
	182	if (WIFSIGNALED(status))
	183	return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
	184
	185	if (!WIFEXITED(status))
	186	return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
	187	code = WEXITSTATUS(status);
	188	switch (code) {
	189	case 127:
	190	return -ERR_RUN_COMMAND_EXEC;
	191	case 0:
	192	return 0;
	193	default:
	194	return -code;
	195	}
	196	}
	197	}
	198
	199	int finish_command(struct child_process *cmd)
	200	{
	201	return wait_or_whine(cmd->pid);
	202	}
	203
	204	int run_command(struct child_process *cmd)
	205	{
	206	int code = start_command(cmd);
	207	if (code)
	208	return code;
	209	return finish_command(cmd);
	210	}
	211
	212	static void prepare_run_command_v_opt(struct child_process *cmd,
	213	const char **argv,
	214	int opt)
	215	{
	216	memset(cmd, 0, sizeof(*cmd));
	217	cmd->argv = argv;
	218	cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
46113a54	219	cmd->exec_cmd = opt & RUN_EXEC_CMD ? 1 : 0;
07800601 IM	220	cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
	221	}
	222
	223	int run_command_v_opt(const char **argv, int opt)
	224	{
	225	struct child_process cmd;
	226	prepare_run_command_v_opt(&cmd, argv, opt);
	227	return run_command(&cmd);
	228	}