[dragonfly.git] / sbin / hammer2 / subs.c

/*
 * Copyright (c) 2011-2012 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@dragonflybsd.org>
 * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "hammer2.h"

/*
 * Obtain a file descriptor that the caller can execute ioctl()'s on.
 */
int
hammer2_ioctl_handle(const char *sel_path)
{
	struct hammer2_ioc_version info;
	int fd;

	if (sel_path == NULL)
		sel_path = ".";

	fd = open(sel_path, O_RDONLY, 0);
	if (fd < 0) {
		fprintf(stderr, "hammer2: Unable to open %s: %s\n",
			sel_path, strerror(errno));
		return(-1);
	}
	if (ioctl(fd, HAMMER2IOC_VERSION_GET, &info) < 0) {
		fprintf(stderr, "hammer2: '%s' is not a hammer2 filesystem\n",
			sel_path);
		close(fd);
		return(-1);
	}
	return (fd);
}

/*
 * Execute the specified function as a detached independent process/daemon,
 * unless we are in debug mode.  If we are in debug mode the function is
 * executed as a pthread in the current process.
 */
void
hammer2_demon(void *(*func)(void *), void *arg)
{
	pthread_t thread = NULL;
	pid_t pid;
	int ttyfd;

	/*
	 * Do not disconnect in debug mode
	 */
	if (DebugOpt) {
                pthread_create(&thread, NULL, func, arg);
		NormalExit = 0;
		return;
	}

	/*
	 * Otherwise disconnect us.  Double-fork to get rid of the ppid
	 * association and disconnect the TTY.
	 */
	if ((pid = fork()) < 0) {
		fprintf(stderr, "hammer2: fork(): %s\n", strerror(errno));
		exit(1);
	}
	if (pid > 0) {
		while (waitpid(pid, NULL, 0) != pid)
			;
		return;		/* parent returns */
	}

	/*
	 * Get rid of the TTY/session before double-forking to finish off
	 * the ppid.
	 */
	ttyfd = open("/dev/null", O_RDWR);
	if (ttyfd >= 0) {
		if (ttyfd != 0)
			dup2(ttyfd, 0);
		if (ttyfd != 1)
			dup2(ttyfd, 1);
		if (ttyfd != 2)
			dup2(ttyfd, 2);
		if (ttyfd > 2)
			close(ttyfd);
	}

	ttyfd = open("/dev/tty", O_RDWR);
	if (ttyfd >= 0) {
		ioctl(ttyfd, TIOCNOTTY, 0);
		close(ttyfd);
	}
	setsid();

	/*
	 * Second fork to disconnect ppid (the original parent waits for
	 * us to exit).
	 */
	if ((pid = fork()) < 0) {
		_exit(2);
	}
	if (pid > 0)
		_exit(0);

	/*
	 * The double child
	 */
	setsid();
	pthread_create(&thread, NULL, func, arg);
	pthread_exit(NULL);
	_exit(2);	/* NOT REACHED */
}

/*
 * This swaps endian for a hammer2_msg_hdr.  Note that the extended
 * header is not adjusted, just the core header.
 */
void
hammer2_bswap_head(hammer2_msg_hdr_t *head)
{
	head->magic	= bswap16(head->magic);
	head->icrc1	= bswap16(head->icrc1);
	head->salt	= bswap32(head->salt);
	head->source	= bswap16(head->source);
	head->target	= bswap16(head->target);
	head->msgid	= bswap32(head->msgid);
	head->cmd	= bswap32(head->cmd);
	head->error	= bswap16(head->error);
	head->resv05	= bswap16(head->resv05);
	head->icrc2	= bswap16(head->icrc2);
	head->aux_bytes	= bswap16(head->aux_bytes);
	head->aux_icrc	= bswap32(head->aux_icrc);
}
Commit	Line	Data
2910a90c MD	1	/*
	2	* Copyright (c) 2011-2012 The DragonFly Project. All rights reserved.
	3	*
	4	* This code is derived from software contributed to The DragonFly Project
	5	* by Matthew Dillon <dillon@dragonflybsd.org>
	6	* by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	*
	12	* 1. Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	* 2. Redistributions in binary form must reproduce the above copyright
	15	* notice, this list of conditions and the following disclaimer in
	16	* the documentation and/or other materials provided with the
	17	* distribution.
	18	* 3. Neither the name of The DragonFly Project nor the names of its
	19	* contributors may be used to endorse or promote products derived
	20	* from this software without specific, prior written permission.
	21	*
	22	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	23	* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	24	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	25	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	26	* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	27	* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
	28	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	29	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
	30	* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	31	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	32	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	33	* SUCH DAMAGE.
	34	*/
	35
	36	#include "hammer2.h"
	37
	38	/*
	39	* Obtain a file descriptor that the caller can execute ioctl()'s on.
	40	*/
	41	int
	42	hammer2_ioctl_handle(const char *sel_path)
	43	{
	44	struct hammer2_ioc_version info;
	45	int fd;
	46
5ba65e34 MD	47	if (sel_path == NULL)
	48	sel_path = ".";
	49
2910a90c MD	50	fd = open(sel_path, O_RDONLY, 0);
	51	if (fd < 0) {
	52	fprintf(stderr, "hammer2: Unable to open %s: %s\n",
	53	sel_path, strerror(errno));
	54	return(-1);
	55	}
ae183399	56	if (ioctl(fd, HAMMER2IOC_VERSION_GET, &info) < 0) {
2910a90c MD	57	fprintf(stderr, "hammer2: '%s' is not a hammer2 filesystem\n",
	58	sel_path);
	59	close(fd);
	60	return(-1);
	61	}
	62	return (fd);
	63	}
5ba65e34	64
9ab15106 MD	65	/*
	66	* Execute the specified function as a detached independent process/daemon,
	67	* unless we are in debug mode. If we are in debug mode the function is
	68	* executed as a pthread in the current process.
	69	*/
5ba65e34	70	void
9ab15106	71	hammer2_demon(void (func)(void ), void arg)
5ba65e34 MD	72	{
	73	pthread_t thread = NULL;
	74	pid_t pid;
	75	int ttyfd;
	76
	77	/*
	78	* Do not disconnect in debug mode
	79	*/
	80	if (DebugOpt) {
	81	pthread_create(&thread, NULL, func, arg);
	82	NormalExit = 0;
	83	return;
	84	}
	85
	86	/*
	87	* Otherwise disconnect us. Double-fork to get rid of the ppid
	88	* association and disconnect the TTY.
	89	*/
	90	if ((pid = fork()) < 0) {
	91	fprintf(stderr, "hammer2: fork(): %s\n", strerror(errno));
	92	exit(1);
	93	}
	94	if (pid > 0) {
	95	while (waitpid(pid, NULL, 0) != pid)
	96	;
	97	return; /* parent returns */
	98	}
	99
	100	/*
	101	* Get rid of the TTY/session before double-forking to finish off
	102	* the ppid.
	103	*/
	104	ttyfd = open("/dev/null", O_RDWR);
	105	if (ttyfd >= 0) {
	106	if (ttyfd != 0)
	107	dup2(ttyfd, 0);
	108	if (ttyfd != 1)
	109	dup2(ttyfd, 1);
	110	if (ttyfd != 2)
	111	dup2(ttyfd, 2);
	112	if (ttyfd > 2)
	113	close(ttyfd);
	114	}
	115
	116	ttyfd = open("/dev/tty", O_RDWR);
	117	if (ttyfd >= 0) {
	118	ioctl(ttyfd, TIOCNOTTY, 0);
	119	close(ttyfd);
	120	}
	121	setsid();
	122
	123	/*
	124	* Second fork to disconnect ppid (the original parent waits for
	125	* us to exit).
	126	*/
	127	if ((pid = fork()) < 0) {
	128	_exit(2);
	129	}
	130	if (pid > 0)
	131	_exit(0);
	132
	133	/*
	134	* The double child
	135	*/
136	setsid();
137	pthread_create(&thread, NULL, func, arg);
138	pthread_exit(NULL);
139	_exit(2); /* NOT REACHED */
140	}
9ab15106 MD	141
	142	/*
	143	* This swaps endian for a hammer2_msg_hdr. Note that the extended
	144	* header is not adjusted, just the core header.
	145	*/
	146	void
	147	hammer2_bswap_head(hammer2_msg_hdr_t *head)
	148	{
	149	head->magic = bswap16(head->magic);
	150	head->icrc1 = bswap16(head->icrc1);
	151	head->salt = bswap32(head->salt);
	152	head->source = bswap16(head->source);
	153	head->target = bswap16(head->target);
	154	head->msgid = bswap32(head->msgid);
	155	head->cmd = bswap32(head->cmd);
	156	head->error = bswap16(head->error);
	157	head->resv05 = bswap16(head->resv05);
	158	head->icrc2 = bswap16(head->icrc2);
	159	head->aux_bytes = bswap16(head->aux_bytes);
	160	head->aux_icrc = bswap32(head->aux_icrc);
	161	}