/*

 * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>

 *

 *	This program is free software; you can redistribute it and/or modify it

 *	under the terms of the GNU General Public License as published by the

 *	Free Software Foundation version 2 of the License.

 * 

 *	This program is distributed in the hope that it will be useful, but

 *	WITHOUT ANY WARRANTY; without even the implied warranty of

 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 *	General Public License for more details.

 * 

 *	You should have received a copy of the GNU General Public License along

 *	with this program; if not, write to the Free Software Foundation, Inc.,

 *	51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 *

 */

#define MY_MAX(a,b) ((a) > (b) ? (a) : (b))

#define READ_END	0

#define WRITE_END	1

static

int run_program1(struct space *space,

	         const char *command0, char *result,

		 size_t ressize, size_t *reslen, int log);

static

int run_program0(struct space *space,

	         const char *command0, char *result,

		 size_t ressize, size_t *reslen, int log)

{

	int retval = 0;

	int status;

	int outpipe[2] = {-1, -1};

	int errpipe[2] = {-1, -1};

	pid_t pid;

	char arg[PATH_SIZE];

	char program[PATH_SIZE];

	char *argv[(sizeof(arg) / 2) + 1];

	int devnull;

	int i;

	/* build argv from comand */

	strlcpy(arg, command0, sizeof(arg));

	i = 0;

	if (strchr(arg, ' ') != NULL) {

		char *pos = arg;

		while (pos != NULL) {

			if (pos[0] == '\'') {

				/* don't separate if in apostrophes */

				pos++;

				argv[i] = strsep(&pos, "\'");

				while (pos != NULL && pos[0] == ' ')

					pos++;

			} else {

				argv[i] = strsep(&pos, " ");

			}

			dbg("arg[%i] '%s'", i, argv[i]);

			i++;

		}

		argv[i] = NULL;

	} else {

		argv[0] = arg;

		argv[1] = NULL;

	}

	info("'%s'", command0);

	/* prepare pipes from child to parent */

	if (result || log) {

		if (pipe(outpipe) != 0) {

			Perror(space, "pipe failed: %s", strerror(errno));

			return -1;

		}

	}

	if (log) {

		if (pipe(errpipe) != 0) {

			Perror(space, "pipe failed: %s", strerror(errno));

			return -1;

		}

	}

	/* allow programs in /lib/alsa called without the path */

	if (strchr(argv[0], '/') == NULL) {

		strlcpy(program, "/lib/alsa/", sizeof(program));

		strlcat(program, argv[0], sizeof(program));

		argv[0] = program;

	}

	pid = fork();

	switch(pid) {

	case 0:

		/* child closes parent ends of pipes */

		if (outpipe[READ_END] > 0)

			close(outpipe[READ_END]);

		if (errpipe[READ_END] > 0)

			close(errpipe[READ_END]);

		/* discard child output or connect to pipe */

		devnull = open("/dev/null", O_RDWR);

		if (devnull > 0) {

			dup2(devnull, STDIN_FILENO);

			if (outpipe[WRITE_END] < 0)

				dup2(devnull, STDOUT_FILENO);

			if (errpipe[WRITE_END] < 0)

				dup2(devnull, STDERR_FILENO);

			close(devnull);

		} else

			Perror(space, "open /dev/null failed: %s", strerror(errno));

		if (outpipe[WRITE_END] > 0) {

			dup2(outpipe[WRITE_END], STDOUT_FILENO);

			close(outpipe[WRITE_END]);

		}

		if (errpipe[WRITE_END] > 0) {

			dup2(errpipe[WRITE_END], STDERR_FILENO);

			close(errpipe[WRITE_END]);

		}

		execv(argv[0], argv);

		/* we should never reach this */

		Perror(space, "exec of program '%s' failed", argv[0]);

		_exit(1);

	case -1:

		Perror(space, "fork of '%s' failed: %s", argv[0], strerror(errno));

		return -1;

	default:

		/* read from child if requested */

		if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {

			ssize_t count;

			size_t respos = 0;

			/* parent closes child ends of pipes */

			if (outpipe[WRITE_END] > 0)

				close(outpipe[WRITE_END]);

			if (errpipe[WRITE_END] > 0)

				close(errpipe[WRITE_END]);

			/* read child output */

			while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {

				int fdcount;

				fd_set readfds;

				FD_ZERO(&readfds);

				if (outpipe[READ_END] > 0)

					FD_SET(outpipe[READ_END], &readfds);

				if (errpipe[READ_END] > 0)

					FD_SET(errpipe[READ_END], &readfds);

				fdcount = select(MY_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);

				if (fdcount < 0) {

					if (errno == EINTR)

						continue;

					retval = -1;

					break;

				}

				/* get stdout */

				if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {

					char inbuf[1024];

					char *pos;

					char *line;

					count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);

					if (count <= 0) {

						close(outpipe[READ_END]);

						outpipe[READ_END] = -1;

						if (count < 0) {

							Perror(space, "stdin read failed: %s", strerror(errno));

							retval = -1;

						}

						continue;

					}

					inbuf[count] = '\0';

					/* store result for rule processing */

					if (result) {

						if (respos + count < ressize) {

							memcpy(&result[respos], inbuf, count);

							respos += count;

						} else {

							Perror(space, "ressize %ld too short", (long)ressize);

							retval = -1;

						}

					}

					pos = inbuf;

					while ((line = strsep(&pos, "\n")))

						if (pos || line[0] != '\0')

							info("'%s' (stdout) '%s'", argv[0], line);

				}

				/* get stderr */

				if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {

					char errbuf[1024];

					char *pos;

					char *line;

					count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);

					if (count <= 0) {

						close(errpipe[READ_END]);

						errpipe[READ_END] = -1;

						if (count < 0)

							Perror(space, "stderr read failed: %s", strerror(errno));

						continue;

					}

					errbuf[count] = '\0';

					pos = errbuf;

					while ((line = strsep(&pos, "\n")))

						if (pos || line[0] != '\0')

							info("'%s' (stderr) '%s'", argv[0], line);

				}

			}

			if (outpipe[READ_END] > 0)

				close(outpipe[READ_END]);

			if (errpipe[READ_END] > 0)

				close(errpipe[READ_END]);

			/* return the childs stdout string */

			if (result) {

				result[respos] = '\0';

				dbg("result='%s'", result);

				if (reslen)

					*reslen = respos;

			}

		}

		waitpid(pid, &status, 0);

		if (WIFEXITED(status)) {

			info("'%s' returned with status %i", argv[0], WEXITSTATUS(status));

			if (WEXITSTATUS(status) != 0)

				retval = -1;

		} else {

			Perror(space, "'%s' abnormal exit", argv[0]);

			retval = -1;

		}

	}

	return retval;

}

static

int run_program(struct space *space, const char *command0, char *result,

		size_t ressize, size_t *reslen, int log)

{

	if (command0[0] == '_' && command0[1] == '_')

		return run_program1(space, command0, result, ressize, reslen, log);

	return run_program0(space, command0, result, ressize, reslen, log);

}