/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License, Version 1.0 only

 * (the "License").  You may not use this file except in compliance

 * with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Use is subject to license terms.

 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <sys/types.h>

#include <sys/stat.h>

#include <sys/swap.h>

#include <sys/dumpadm.h>

#include <sys/utsname.h>

#include <unistd.h>

#include <string.h>

#include <stdlib.h>

#include <stdio.h>

#include <fcntl.h>

#include <errno.h>

#include "dconf.h"

#include "minfree.h"

#include "utils.h"

#include "swap.h"

typedef struct dc_token {

	const char *tok_name;

	int (*tok_parse)(dumpconf_t *, char *);

	int (*tok_print)(const dumpconf_t *, FILE *);

} dc_token_t;

static int print_device(const dumpconf_t *, FILE *);

static int print_savdir(const dumpconf_t *, FILE *);

static int print_content(const dumpconf_t *, FILE *);

static int print_enable(const dumpconf_t *, FILE *);

static const dc_token_t tokens[] = {

	{ "DUMPADM_DEVICE", dconf_str2device, print_device },

	{ "DUMPADM_SAVDIR", dconf_str2savdir, print_savdir },

	{ "DUMPADM_CONTENT", dconf_str2content, print_content },

	{ "DUMPADM_ENABLE", dconf_str2enable, print_enable },

	{ NULL, NULL, NULL }

};

static const char DC_STR_YES[] = "yes";		/* Enable on string */

static const char DC_STR_NO[] = "no";		/* Enable off string */

static const char DC_STR_SWAP[] = "swap";	/* Default dump device */

/* The pages included in the dump */

static const char DC_STR_KERNEL[] = "kernel";	/* Kernel only */

static const char DC_STR_CURPROC[] = "curproc";	/* Kernel + current process */

static const char DC_STR_ALL[] = "all";		/* All pages */

/*

 * Permissions and ownership for the configuration file:

 */

#define	DC_OWNER	0				/* Uid 0 (root) */

#define	DC_GROUP	1				/* Gid 1 (other) */

#define	DC_PERM	(S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)	/* Mode 0644 */

static void

dconf_init(dumpconf_t *dcp, int dcmode)

{

	struct utsname ut;

	/*

	 * Default device for dumps is 'swap' (appropriate swap device),

	 * and default savecore directory is /var/crash/`uname -n`,

	 * which is compatible with pre-dumpadm behavior.

	 */

	(void) strcpy(dcp->dc_device, DC_STR_SWAP);

	(void) strcpy(dcp->dc_savdir, "/var/crash");

	if (uname(&ut) != -1) {

		(void) strcat(dcp->dc_savdir, "/");

		(void) strcat(dcp->dc_savdir, ut.nodename);

	}

	/*

	 * Default is contents kernel, and savecore enabled on reboot.

	 */

	dcp->dc_cflags = DUMP_KERNEL;

	dcp->dc_enable = DC_ON;

	dcp->dc_mode = dcmode;

	dcp->dc_conf_fp = NULL;

	dcp->dc_conf_fd = -1;

	dcp->dc_dump_fd = -1;

}

int

dconf_open(dumpconf_t *dcp, const char *dpath, const char *fpath, int dcmode)

{

	char buf[BUFSIZ];

	int line;

	dconf_init(dcp, dcmode);

	if ((dcp->dc_dump_fd = open(dpath, O_RDWR)) == -1) {

		warn(gettext("failed to open %s"), dpath);

		return (-1);

	}

	if ((dcp->dc_conf_fd = open(fpath, O_RDWR | O_CREAT, DC_PERM)) == -1) {

		warn(gettext("failed to open %s"), fpath);

		return (-1);

	}

	if ((dcp->dc_conf_fp = fdopen(dcp->dc_conf_fd, "r+")) == NULL) {

		warn(gettext("failed to open stream for %s"), fpath);

		return (-1);

	}

	/*

	 * If we're in override mode, the current kernel settings override the

	 * default settings and anything invalid in the configuration file.

	 */

	if (dcmode == DC_OVERRIDE)

		(void) dconf_getdev(dcp);

	for (line = 1; fgets(buf, BUFSIZ, dcp->dc_conf_fp) != NULL; line++) {

		char name[BUFSIZ], value[BUFSIZ];

		const dc_token_t *tokp;

		int len;

		if (buf[0] == '#' || buf[0] == '\n')

			continue;

		/*

		 * Look for "name=value", with optional whitespace on either

		 * side, terminated by a newline, and consuming the whole line.

		 */

		/* LINTED - unbounded string specifier */

		if (sscanf(buf, " %[^=]=%s \n%n", name, value, &len) == 2 &&

		    name[0] != '\0' && value[0] != '\0' && len == strlen(buf)) {

			/*

			 * Locate a matching token in the tokens[] table,

			 * and invoke its parsing function.

			 */

			for (tokp = tokens; tokp->tok_name != NULL; tokp++) {

				if (strcmp(name, tokp->tok_name) == 0) {

					if (tokp->tok_parse(dcp, value) == -1) {

						warn(gettext("\"%s\", line %d: "

						    "warning: invalid %s\n"),

						    fpath, line, name);

					}

					break;

				}

			}

			/*

			 * If we hit the end of the tokens[] table,

			 * no matching token was found.

			 */

			if (tokp->tok_name == NULL) {

				warn(gettext("\"%s\", line %d: warning: "

				    "invalid token: %s\n"), fpath, line, name);

			}

		} else {

			warn(gettext("\"%s\", line %d: syntax error\n"),

			    fpath, line);

		}

	}

	/*

	 * If we're not in override mode, the current kernel settings

	 * override the settings read from the configuration file.

	 */

	if (dcmode == DC_CURRENT)

		return (dconf_getdev(dcp));

	return (0);

}

int

dconf_getdev(dumpconf_t *dcp)

{

	int status = 0;

	if ((dcp->dc_cflags = ioctl(dcp->dc_dump_fd, DIOCGETCONF, 0)) == -1) {

		warn(gettext("failed to get kernel dump settings"));

		status = -1;

	}

	if (ioctl(dcp->dc_dump_fd, DIOCGETDEV, dcp->dc_device) == -1) {

		if (errno != ENODEV) {

			warn(gettext("failed to get dump device"));

			status = -1;

		} else

			dcp->dc_device[0] = '\0';

	}

	return (status);

}

int

dconf_close(dumpconf_t *dcp)

{

	if (fclose(dcp->dc_conf_fp) == 0) {

		(void) close(dcp->dc_dump_fd);

		return (0);

	}

	return (-1);

}

int

dconf_write(dumpconf_t *dcp)

{

	const dc_token_t *tokp;

	if (fseeko(dcp->dc_conf_fp, (off_t)0, SEEK_SET) == -1) {

		warn(gettext("failed to seek config file"));

		return (-1);

	}

	if (ftruncate(dcp->dc_conf_fd, (off_t)0) == -1) {

		warn(gettext("failed to truncate config file"));

		return (-1);

	}

	(void) fputs("#\n# dumpadm.conf\n#\n"

	    "# Configuration parameters for system crash dump.\n"

	    "# Do NOT edit this file by hand -- use dumpadm(1m) instead.\n"

	    "#\n", dcp->dc_conf_fp);

	for (tokp = tokens; tokp->tok_name != NULL; tokp++) {

		if (fprintf(dcp->dc_conf_fp, "%s=", tokp->tok_name) == -1 ||

		    tokp->tok_print(dcp, dcp->dc_conf_fp) == -1) {

			warn(gettext("failed to write token"));

			return (-1);

		}

	}

	if (fflush(dcp->dc_conf_fp) != 0)

		warn(gettext("warning: failed to flush config file"));

	if (fsync(dcp->dc_conf_fd) == -1)

		warn(gettext("warning: failed to sync config file to disk"));

	if (fchmod(dcp->dc_conf_fd, DC_PERM) == -1)

		warn(gettext("warning: failed to reset mode on config file"));

	if (fchown(dcp->dc_conf_fd, DC_OWNER, DC_GROUP) == -1)

		warn(gettext("warning: failed to reset owner on config file"));

	return (0);

}

static int

open_stat64(const char *path, struct stat64 *stp)

{

	int fd = open64(path, O_RDONLY);

	if (fd >= 0) {

		int status = fstat64(fd, stp);

		(void) close(fd);

		return (status);

	}

	return (-1);

}

static int

dconf_swap_compare(const swapent_t *s1, const swapent_t *s2)

{

	struct stat64 st1, st2;

	int prefer_s1 = -1;	/* Return value to move s1 left (s1 < s2) */

	int prefer_s2 = 1;	/* Return value to move s2 left (s1 > s2) */

	/*

	 * First try: open and fstat each swap entry.  If either system

	 * call fails, arbitrarily prefer the other entry.

	 */

	if (open_stat64(s1->ste_path, &st1) == -1)

		return (prefer_s2);

	if (open_stat64(s2->ste_path, &st2) == -1)

		return (prefer_s1);

	/*

	 * Second try: if both entries are block devices, or if

	 * neither is a block device, prefer the larger.

	 */

	if (S_ISBLK(st1.st_mode) == S_ISBLK(st2.st_mode)) {

		if (st2.st_size > st1.st_size)

			return (prefer_s2);

		return (prefer_s1);

	}

	/*

	 * Third try: prefer the entry that is a block device.

	 */

	if (S_ISBLK(st2.st_mode))

		return (prefer_s2);

	return (prefer_s1);

}

static int

dconf_dev_ioctl(dumpconf_t *dcp, int cmd)

{

	if (ioctl(dcp->dc_dump_fd, cmd, dcp->dc_device) == 0)

		return (0);

	switch (errno) {

	case ENOTSUP:

		warn(gettext("dumps not supported on %s\n"), dcp->dc_device);

		break;

	case EBUSY:

		warn(gettext("device %s is already in use\n"), dcp->dc_device);

		break;

	default:

		/*

		 * NOTE: The stmsboot(1M) command's boot-up script parses this

		 * error to get the dump device name. If you change the format

		 * of this message, make sure that stmsboot(1M) is in sync.

		 */

		warn(gettext("cannot use %s as dump device"), dcp->dc_device);

	}

	return (-1);

}

int

{

	/*

	 * Save the existing dump configuration in case something goes wrong.

	 */

	if ((oconf = ioctl(dcp->dc_dump_fd, DIOCGETCONF, 0)) == -1) {

		warn(gettext("failed to get kernel dump configuration"));

		return (-1);

	}

	oconf &= DUMP_CONTENT;

	dcp->dc_cflags &= DUMP_CONTENT;

	if (ioctl(dcp->dc_dump_fd, DIOCSETCONF, dcp->dc_cflags) == -1) {

		warn(gettext("failed to update kernel dump configuration"));

		return (-1);

	}

	if (strcmp(dcp->dc_device, DC_STR_SWAP) == 0) {

		swaptbl_t *swt;

		int i;

		if ((swt = swap_list()) == NULL)

			goto err;

		if (swt->swt_n == 0) {

			warn(gettext("no swap devices are available\n"));

			free(swt);

			goto err;

		}

		qsort(&swt->swt_ent[0], swt->swt_n, sizeof (swapent_t),

		    (int (*)(const void *, const void *))dconf_swap_compare);

		/*

		 * Iterate through the prioritized list of swap entries,

		 * trying to configure one as the dump device.

		 */

		for (i = 0; i < swt->swt_n; i++) {

			if (ioctl(dcp->dc_dump_fd, DIOCSETDEV,

			    swt->swt_ent[i].ste_path) == 0) {

				(void) strcpy(dcp->dc_device,

				    swt->swt_ent[i].ste_path);

				break;

			}

		}

		if (i == swt->swt_n) {

			warn(gettext("no swap devices could be configured "

			    "as the dump device\n"));

			free(swt);

			goto err;

		}

		free(swt);

	} else if (dcp->dc_device[0] != '\0') {

		/*

		 * If we're not in forcible update mode, then fail the change

		 * if the selected device cannot be used as the dump device,

		 * or if it is not big enough to hold the dump.

		 */

		if (dcp->dc_mode == DC_CURRENT) {

			struct stat64 st;

			uint64_t d;

			if (dconf_dev_ioctl(dcp, DIOCTRYDEV) == -1)

				goto err;

			if (open_stat64(dcp->dc_device, &st) == -1) {

				warn(gettext("failed to access %s"),

				    dcp->dc_device);

				goto err;

			}

			if (ioctl(dcp->dc_dump_fd, DIOCGETDUMPSIZE, &d) == -1) {

				warn(gettext("failed to get kernel dump size"));

				goto err;

			}

			if (st.st_size < d) {

				warn(gettext("dump device %s is too small to "

				    "hold a system dump\ndump size %llu "

				    "bytes, device size %lld bytes\n"),

				    dcp->dc_device, d, st.st_size);

				goto err;

			}

		}

		if (dconf_dev_ioctl(dcp, DIOCSETDEV) == -1)

			goto err;

	}

	/*

	 * Now that we've updated the dump device, we need to issue another

	 * ioctl to re-read the config flags to determine whether we

	 * obtained DUMP_EXCL access on our dump device.

	 */

	if ((dcp->dc_cflags = ioctl(dcp->dc_dump_fd, DIOCGETCONF, 0)) == -1) {

		warn(gettext("failed to re-read kernel dump configuration"));

		return (-1);

	}

	return (0);

err:

	(void) ioctl(dcp->dc_dump_fd, DIOCSETCONF, oconf);

	return (-1);

}

void

dconf_print(dumpconf_t *dcp, FILE *fp)

{

	u_longlong_t min;

	char *content;

	if (dcp->dc_cflags & DUMP_ALL)

		content = gettext("all");

	else if (dcp->dc_cflags & DUMP_CURPROC)

		content = gettext("kernel and current process");

	else

		content = gettext("kernel");

	(void) fprintf(fp, gettext("      Dump content: %s pages\n"), content);

	if (dcp->dc_device[0] != '\0') {

		(void) fprintf(fp, gettext("       Dump device: %s (%s)\n"),

		    dcp->dc_device, (dcp->dc_cflags & DUMP_EXCL) ?

		    gettext("dedicated") : gettext("swap"));

	} else {

		(void) fprintf(fp, gettext("       Dump device: none "

		    "(dumps disabled)\n"));

	}

	(void) fprintf(fp, gettext("Savecore directory: %s"), dcp->dc_savdir);

	if (minfree_read(dcp->dc_savdir, &min) == 0) {

		if (min < 1024 || (min % 1024) != 0)

			(void) fprintf(fp, gettext(" (minfree = %lluKB)"), min);

		else

			(void) fprintf(fp, gettext(" (minfree = %lluMB)"),

			    min / 1024);

	}

	(void) fprintf(fp, gettext("\n"));

	(void) fprintf(fp, gettext("  Savecore enabled: %s\n"),

	    (dcp->dc_enable == DC_OFF) ? gettext("no") : gettext("yes"));

}

int

dconf_str2device(dumpconf_t *dcp, char *buf)

{

	if (strcasecmp(buf, DC_STR_SWAP) == 0) {

		(void) strcpy(dcp->dc_device, DC_STR_SWAP);

		return (0);

	}

	if (valid_abspath(buf)) {

		(void) strcpy(dcp->dc_device, buf);

		return (0);