/*
 * Soft:        multipath device mapper target autoconfig
 *
 * Version:     $Id: main.h,v 0.0.1 2003/09/18 15:13:38 cvaroqui Exp $
 *
 * Author:      Copyright (C) 2003 Christophe Varoqui
 *
 *              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.
 *
 *              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; either version
 *              2 of the License, or (at your option) any later version.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/kdev_t.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sysfs/libsysfs.h>
#include "libdevmapper/libdevmapper.h"
#include "main.h"
#include "devinfo.h"

/* White list switch */
static int
get_unique_id(struct path * mypath)
{
	int i;
	static struct {
		char * vendor;
		char * product;
		int iopolicy;
		int (*getuid) (char *, char *);
	} wlist[] = {
		{"COMPAQ  ", "HSV110 (C)COMPAQ", GROUP_BY_SERIAL, &get_evpd_wwid},
		{"COMPAQ  ", "MSA1000         ", GROUP_BY_SERIAL, &get_evpd_wwid},
		{"COMPAQ  ", "MSA1000 VOLUME  ", GROUP_BY_SERIAL, &get_evpd_wwid},
		{"DEC     ", "HSG80           ", GROUP_BY_SERIAL, &get_evpd_wwid},
		{"HP      ", "HSV100          ", GROUP_BY_SERIAL, &get_evpd_wwid},
		{"HP      ", "A6189A          ", MULTIBUS, &get_evpd_wwid},
		{"HP      ", "OPEN-           ", MULTIBUS, &get_evpd_wwid},
		{"DDN     ", "SAN DataDirector", MULTIBUS, &get_evpd_wwid},
		{"FSC     ", "CentricStor     ", MULTIBUS, &get_evpd_wwid},
		{"HITACHI ", "DF400           ", MULTIBUS, &get_evpd_wwid},
		{"HITACHI ", "DF500           ", MULTIBUS, &get_evpd_wwid},
		{"HITACHI ", "DF600           ", MULTIBUS, &get_evpd_wwid},
		{"IBM     ", "ProFibre 4000R  ", MULTIBUS, &get_evpd_wwid},
		{"SGI     ", "TP9100          ", MULTIBUS, &get_evpd_wwid},
		{"SGI     ", "TP9300          ", MULTIBUS, &get_evpd_wwid},
		{"SGI     ", "TP9400          ", MULTIBUS, &get_evpd_wwid},
		{"SGI     ", "TP9500          ", MULTIBUS, &get_evpd_wwid},
		{NULL, NULL, 0, NULL},
	};

	for (i = 0; wlist[i].vendor; i++) {
		if (strncmp(mypath->vendor_id, wlist[i].vendor, 8) == 0 &&
		    strncmp(mypath->product_id, wlist[i].product, 16) == 0) {
			mypath->iopolicy = wlist[i].iopolicy;
			if (!wlist[i].getuid(mypath->sg_dev, mypath->wwid))
				return 0;
		}
	}
	return 1;
}

static int
blacklist (char * dev) {
	int i;
	static struct {
		char * headstr;
		int lengh;
	} blist[] = {
		{"cciss", 5},
		{"hd", 2},
		{"md", 2},
		{"dm", 2},
		{"sr", 2},
		{"scd", 3},
		{"ram", 3},
		{"raw", 3},
		{NULL, 0},
	};

	for (i = 0; blist[i].lengh; i++) {
		if (strncmp(dev, blist[i].headstr, blist[i].lengh) == 0)
			return 1;
	}
	return 0;
}

static int
get_all_paths_sysfs(struct env * conf, struct path * all_paths)
{
	int k=0;
	struct sysfs_directory * sdir;
	struct sysfs_directory * devp;
	struct sysfs_link * linkp;
	char refwwid[WWID_SIZE];
	char empty_buff[WWID_SIZE];
	char buff[FILE_NAME_SIZE];
	char path[FILE_NAME_SIZE];
	struct path curpath;

	/* if called from hotplug, only consider the paths that relate */
	/* to the device pointed by conf.hotplugdev */
	memset(empty_buff, 0, WWID_SIZE);
	memset(refwwid, 0, WWID_SIZE);
	if (strncmp("/devices", conf->hotplugdev, 8) == 0) {
		sprintf(buff, "%s%s/block",
			conf->sysfs_path, conf->hotplugdev);
		memset(conf->hotplugdev, 0, FILE_NAME_SIZE);

		/* if called from hotplug but with no block, leave */
		if (0 > readlink(buff, conf->hotplugdev, FILE_NAME_SIZE))
			return 0;

		basename(conf->hotplugdev, buff);
		sprintf(curpath.sg_dev, "/dev/%s", buff);

		get_lun_strings(curpath.vendor_id,
				curpath.product_id,
				curpath.rev,
				curpath.sg_dev);
		get_serial(curpath.serial, curpath.sg_dev);
		if (!get_unique_id(&curpath))
			return 0;
		strcpy(refwwid, curpath.wwid);
		memset(&curpath, 0, sizeof(path));
	}

	sprintf(path, "%s/block", conf->sysfs_path);
	sdir = sysfs_open_directory(path);
	sysfs_read_directory(sdir);

	dlist_for_each_data(sdir->subdirs, devp, struct sysfs_directory) {
		if (blacklist(devp->name))
			continue;

		sysfs_read_directory(devp);

		if(devp->links == NULL)
			continue;

		dlist_for_each_data(devp->links, linkp, struct sysfs_link) {
			if (!strncmp(linkp->name, "device", 6))
				break;
		}

		if (linkp == NULL) {
			continue;
		}

		basename(devp->path, buff);
		sprintf(curpath.sg_dev, "/dev/%s", buff);

		get_lun_strings(curpath.vendor_id,
				curpath.product_id,
				curpath.rev,
				curpath.sg_dev);
		get_serial(curpath.serial, curpath.sg_dev);
		if(!get_unique_id(&curpath)) {
			memset(&curpath, 0, sizeof(path));
			continue;
		}

		if (memcmp(empty_buff, refwwid, WWID_SIZE) != 0 && 
		    strncmp(curpath.wwid, refwwid, WWID_SIZE) != 0) {
			memset(&curpath, 0, sizeof(path));
			continue;
		}

		strcpy(all_paths[k].sg_dev, curpath.sg_dev);
		strcpy(all_paths[k].dev, curpath.sg_dev);
		strcpy(all_paths[k].wwid, curpath.wwid);
		strcpy(all_paths[k].vendor_id, curpath.vendor_id);
		strcpy(all_paths[k].product_id, curpath.product_id);
		all_paths[k].iopolicy = curpath.iopolicy;

		/* done with curpath, zero for reuse */
		memset(&curpath, 0, sizeof(path));

		basename(linkp->target, buff);
		sscanf(buff, "%i:%i:%i:%i",
			&all_paths[k].sg_id.host_no,
			&all_paths[k].sg_id.channel,
			&all_paths[k].sg_id.scsi_id,
			&all_paths[k].sg_id.lun);
		k++;
	}
	sysfs_close_directory(sdir);
	return 0;
}

static int
get_all_paths_nosysfs(struct env * conf, struct path * all_paths,
		      struct scsi_dev * all_scsi_ids)
{
	int k, i, fd;
	char buff[FILE_NAME_SIZE];
	char file_name[FILE_NAME_SIZE];

	for (k = 0; k < conf->max_devs; k++) {
		strcpy(file_name, "/dev/sg");
		sprintf(buff, "%d", k);
		strncat(file_name, buff, FILE_NAME_SIZE);
		strcpy(all_paths[k].sg_dev, file_name);

		get_lun_strings(all_paths[k].vendor_id,
				all_paths[k].product_id,
				all_paths[k].rev,
				all_paths[k].sg_dev);
		get_serial(all_paths[k].serial, all_paths[k].sg_dev);
		if (!get_unique_id(&all_paths[k]))
			continue;

		if ((fd = open(all_paths[k].sg_dev, O_RDONLY)) < 0)
			return 0;

		if (0 > ioctl(fd, SG_GET_SCSI_ID, &(all_paths[k].sg_id)))
			printf("device %s failed on sg ioctl, skip\n",
			       file_name);

		close(fd);

		for (i = 0; i < conf->max_devs; i++) {
			if ((all_paths[k].sg_id.host_no ==
			     all_scsi_ids[i].host_no)
			    && (all_paths[k].sg_id.scsi_id ==
				(all_scsi_ids[i].scsi_id.dev_id & 0xff))
			    && (all_paths[k].sg_id.lun ==
				((all_scsi_ids[i].scsi_id.dev_id >> 8) & 0xff))
			    && (all_paths[k].sg_id.channel ==
				((all_scsi_ids[i].scsi_id.
				  dev_id >> 16) & 0xff))) {
				strcpy(all_paths[k].dev, all_scsi_ids[i].dev);
				break;
			}
		}
	}
	return 0;
}

static int
get_all_scsi_ids(struct env * conf, struct scsi_dev * all_scsi_ids)
{
	int k, big, little, res, host_no, fd;
	char buff[64];
	char fname[FILE_NAME_SIZE];
	struct scsi_idlun my_scsi_id;

	for (k = 0; k < conf->max_devs; k++) {
		strcpy(fname, "/dev/sd");
		if (k < 26) {
			buff[0] = 'a' + (char) k;
			buff[1] = '\0';
			strcat(fname, buff);
		} else if (k <= 255) {
			/* assumes sequence goes x,y,z,aa,ab,ac etc */
			big = k / 26;
			little = k - (26 * big);
			big = big - 1;

			buff[0] = 'a' + (char) big;
			buff[1] = 'a' + (char) little;
			buff[2] = '\0';
			strcat(fname, buff);
		} else
			strcat(fname, "xxxx");

		if ((fd = open(fname, O_RDONLY)) < 0) {
			if (conf->verbose)
				fprintf(stderr, "can't open %s. mknod ?",
					fname); 
			continue;
		}

		res = ioctl(fd, SCSI_IOCTL_GET_IDLUN, &my_scsi_id);
		if (res < 0) {
			close(fd);
			printf("Could not get scsi idlun\n");
			continue;
		}

		res = ioctl(fd, SCSI_IOCTL_GET_BUS_NUMBER, &host_no);
		if (res < 0) {
			close(fd);
			printf("Could not get host_no\n");
			continue;
		}

		close(fd);

		strcpy(all_scsi_ids[k].dev, fname);
		all_scsi_ids[k].scsi_id = my_scsi_id;
		all_scsi_ids[k].host_no = host_no;
	}
	return 0;
}

/* print_path style */
#define ALL	0
#define NOWWID	1

static void
print_path(struct path * all_paths, int k, int style)
{
	if (style != NOWWID)
		printf("%s ", all_paths[k].wwid);
	else
		printf(" \\_");
	printf("(%i %i %i %i) ",
	       all_paths[k].sg_id.host_no,
	       all_paths[k].sg_id.channel,
	       all_paths[k].sg_id.scsi_id, all_paths[k].sg_id.lun);
	if(0 != strcmp(all_paths[k].sg_dev, all_paths[k].dev))
		printf("%s ", all_paths[k].sg_dev);
	printf("%s ", all_paths[k].dev);
	printf("[%.16s]\n", all_paths[k].product_id);
}

static void
print_all_path(struct env * conf, struct path * all_paths)
{
	int k;
	char empty_buff[WWID_SIZE];

	memset(empty_buff, 0, WWID_SIZE);
	for (k = 0; k < conf->max_devs; k++) {
		if (memcmp(empty_buff, all_paths[k].wwid, WWID_SIZE) == 0)
			continue;
		print_path(all_paths, k, ALL);
	}
}

static void
print_all_mp(struct path * all_paths, struct multipath * mp, int nmp)
{
	int k, i;

	for (k = 0; k <= nmp; k++) {
		printf("%s\n", mp[k].wwid);
		for (i = 0; i <= mp[k].npaths; i++)
			print_path(all_paths, PINDEX(k,i), NOWWID);
	}
}

static int
coalesce_paths(struct env * conf, struct multipath * mp,
	       struct path * all_paths)
{
	int k, i, nmp, np, already_done;
	char empty_buff[WWID_SIZE];

	nmp = -1;
	already_done = 0;
	memset(empty_buff, 0, WWID_SIZE);

	for (k = 0; k < conf->max_devs - 1; k++) {
		/* skip this path for some reason */

		/* 1. if path has no unique id */
		if (memcmp(empty_buff, all_paths[k].wwid, WWID_SIZE) == 0)
			continue;

		/* 2. if mp with this uid already instanciated */
		for (i = 0; i <= nmp; i++) {
			if (0 == strcmp(mp[i].wwid, all_paths[k].wwid))
				already_done = 1;
		}
		if (already_done) {
			already_done = 0;
			continue;
		}

		/* at this point, we know we really got a new mp */
		np = 0;
		nmp++;
		strcpy(mp[nmp].wwid, all_paths[k].wwid);
		PINDEX(nmp,np) = k;

		if (mp[nmp].size == 0)
			mp[nmp].size = get_disk_size(all_paths[k].dev);

		for (i = k + 1; i < conf->max_devs; i++) {
			if (0 == strcmp(all_paths[k].wwid, all_paths[i].wwid)) {
				np++;
				PINDEX(nmp,np) = i;
				mp[nmp].npaths = np;
			}
		}
	}
	return nmp;
}

static void
group_by_serial(struct multipath * mp, struct path * all_paths, char * str) {
	int path_count, pg_count = 0;
	int i, k;
	int * bitmap;
	char path_buff[FILE_NAME_SIZE];
	char pg_buff[FILE_NAME_SIZE];
	char * path_buff_p = &path_buff[0];
	char * pg_buff_p = &pg_buff[0];

	/* init the bitmap */
	bitmap = malloc((mp->npaths + 1) * sizeof(int));
	memset(bitmap, 0, (mp->npaths + 1) * sizeof(int));

	for (i = 0; i <= mp->npaths; i++) {
		if (bitmap[i])
			continue;

		/* here, we really got a new pg */
		pg_count++;
		path_count = 1;
		memset(&path_buff, 0, FILE_NAME_SIZE * sizeof(char));
		path_buff_p = &path_buff[0];

		path_buff_p += sprintf(path_buff_p, " %s", all_paths[mp->pindex[i]].dev);
		bitmap[i] = 1;

		for (k = i + 1; k <= mp->npaths; k++) {
			if (bitmap[k])
				continue;
			if (0 == strcmp(all_paths[mp->pindex[i]].serial,
					all_paths[mp->pindex[k]].serial)) {
				path_buff_p += sprintf(path_buff_p, " %s", all_paths[mp->pindex[k]].dev);
				bitmap[k] = 1;
				path_count++;
			}
		}
		pg_buff_p += sprintf(pg_buff_p, " 1 round-robin %i 0%s",
				     path_count, path_buff);
	}
	sprintf(str, " %i%s", pg_count, pg_buff);
	free(bitmap);
}

static int
dm_simplecmd(int task, const char *name) {
	int r = 0;
	struct dm_task *dmt;

	if (!(dmt = dm_task_create(task)))
		return 0;

	if (!dm_task_set_name(dmt, name))
		goto out;

	r = dm_task_run(dmt);

	out:
		dm_task_destroy(dmt);
		return r;
}

static int
dm_addmap(int task, const char *name, const char *params, long size) {
	struct dm_task *dmt;

	if (!(dmt = dm_task_create(task)))
		return 0;

	if (!dm_task_set_name(dmt, name))
		goto addout;

	if (!dm_task_add_target(dmt, 0, size, DM_TARGET, params))
		goto addout;

	if (!dm_task_run(dmt))
		goto addout;

	addout:
	dm_task_destroy(dmt);
	return 1;
}

static int
setup_map(struct env * conf, struct path * all_paths,
	struct multipath * mp, int index, int op)
{
	char params[255];
	char * params_p;
	int i, np;

	/* defaults for multipath target */
	int dm_pg_prio              = 1;
	char * dm_ps_name           = "round-robin";
	int dm_ps_nr_args           = 0;

	params_p = &params[0];

	np = 0;
	for (i=0; i<=mp[index].npaths; i++) {
		if (0 == all_paths[PINDEX(index,i)].sg_id.scsi_type)
			np++;
	}

	if (np < 1)
		return 0;

	if ((all_paths[PINDEX(index,0)].iopolicy == MULTIBUS &&
	    conf->iopolicy == -1) || conf->iopolicy == MULTIBUS) {
		params_p += sprintf(params_p, " 1 %i %s %i %i",
				    dm_pg_prio, dm_ps_name, np, dm_ps_nr_args);
		
		for (i=0; i<=mp[index].npaths; i++) {
			if (0 != all_paths[PINDEX(index,i)].sg_id.scsi_type)
				continue;
			params_p += sprintf(params_p, " %s",
					    all_paths[PINDEX(index,i)].dev);
		}
	}

	if ((all_paths[PINDEX(index,0)].iopolicy == FAILOVER &&
	     conf->iopolicy == -1) || conf->iopolicy == FAILOVER) {
		params_p += sprintf(params_p, " %i", mp[index].npaths + 1);
		for (i=0; i<=mp[index].npaths; i++) {
			if (0 != all_paths[PINDEX(index,i)].sg_id.scsi_type)
				continue;
			params_p += sprintf(params_p, " %i %s ",
					    dm_pg_prio, dm_ps_name);
			params_p += sprintf(params_p, "1 %i",
					    dm_ps_nr_args);
			params_p += sprintf(params_p, " %s",
					    all_paths[PINDEX(index,i)].dev);
		}
	}

	if ((all_paths[PINDEX(index,0)].iopolicy == GROUP_BY_SERIAL &&
	     conf->iopolicy == -1) || conf->iopolicy == GROUP_BY_SERIAL) {
		group_by_serial(&mp[index], all_paths, params_p);
	}

	if (mp[index].size < 0)
		return 0;

	if (!conf->quiet) {
		if (op == DM_DEVICE_RELOAD)
			printf("U:");
		if (op == DM_DEVICE_CREATE)
			printf("N:");
		printf("%s:0 %li %s %s\n",
			mp[index].wwid, mp[index].size, DM_TARGET, params);
	}

	if (op == DM_DEVICE_RELOAD)
		dm_simplecmd(DM_DEVICE_SUSPEND, mp[index].wwid);

	dm_addmap(op, mp[index].wwid, params, mp[index].size);

	if (op == DM_DEVICE_RELOAD)
		dm_simplecmd(DM_DEVICE_RESUME, mp[index].wwid);

	return 1;
}

static int
map_present(char * str)
{
        int r = 0;
	struct dm_task *dmt;
        struct dm_names *names;
        unsigned next = 0;

	if (!(dmt = dm_task_create(DM_DEVICE_LIST)))
		return 0;

	if (!dm_task_run(dmt))
		goto out;

	if (!(names = dm_task_get_names(dmt)))
		goto out;

	if (!names->dev) {
		goto out;
	}

	do {
		if (0 == strcmp(names->name, str))
			r = 1;
		next = names->next;
		names = (void *) names + next;
	} while (next);

	out:
	dm_task_destroy(dmt);
	return r;
}

static void
usage(char * progname)
{
	fprintf(stderr, VERSION_STRING);
	fprintf(stderr, "Usage: %s [-v|-q] [-d] [-m max_devs]",
		progname);
	fprintf(stderr,	"[-p failover|multibus|group_by_serial] [device]\n");
	fprintf(stderr, "\t-v\t\tverbose, print all paths and multipaths\n");
	fprintf(stderr, "\t-q\t\tquiet, no output at all\n");
	fprintf(stderr, "\t-d\t\tdry run, do not create or update devmaps\n");
	fprintf(stderr, "\t-m max_devs\tscan {max_devs} devices at most\n");
	fprintf(stderr, "\t-p policy\tforce maps to specified policy :\n");
	fprintf(stderr, "\t   failover\t\t- 1 path per priority group\n");
	fprintf(stderr, "\t   multibus\t\t- all paths in 1 priority group\n");
	fprintf(stderr, "\t   group_by_serial\t- 1 priority group per serial\n");
	fprintf(stderr, "\tdevice\t\tlimit scope to the device's multipath\n");
	fprintf(stderr, "\t\t\t(hotplug-style $DEVPATH reference)\n");
	exit(1);
}

int
main(int argc, char *argv[])
{
	struct multipath * mp;
	struct path * all_paths;
	struct scsi_dev * all_scsi_ids;
	struct env conf;
	int i, k, nmp;

	/* Default behaviour */
	conf.max_devs = MAX_DEVS;
	conf.dry_run = 0;	/* 1 == Do not Create/Update devmaps */
	conf.verbose = 0;	/* 1 == Print all_paths and mp */
	conf.quiet = 0;		/* 1 == Do not even print devmaps */
	conf.iopolicy = -1;	/* Apply the defaults in get_unique_id() */

	for (i = 1; i < argc; ++i) {
		if (0 == strcmp("-v", argv[i])) {
			if (conf.quiet == 1)
				usage(argv[0]);
			conf.verbose = 1;
		} else if (0 == strcmp("-m", argv[i])) {
			conf.max_devs = atoi(argv[++i]);
			if (conf.max_devs < 2)
				usage(argv[0]);
		} else if (0 == strcmp("-q", argv[i])) {
			if (conf.verbose == 1)
				usage(argv[0]);
			conf.quiet = 1;
		} else if (0 == strcmp("-d", argv[i]))
			conf.dry_run = 1;
		else if (0 == strcmp("-p", argv[i])) {
			i++;
			if (!strcmp(argv[i], "failover"))
				conf.iopolicy = FAILOVER;
			if (!strcmp(argv[i], "multibus"))
				conf.iopolicy = MULTIBUS;
			if (!strcmp(argv[i], "group_by_serial"))
				conf.iopolicy = GROUP_BY_SERIAL;
		} else if (*argv[i] == '-') {
			fprintf(stderr, "Unknown switch: %s\n", argv[i]);
			usage(argv[0]);
		} else
			strncpy(conf.hotplugdev, argv[i], FILE_NAME_SIZE);
	}

	/* dynamic allocations */
	mp = malloc(conf.max_devs * sizeof(struct multipath));
	all_paths = malloc(conf.max_devs * sizeof(struct path));
	all_scsi_ids = malloc(conf.max_devs * sizeof(struct scsi_dev));
	if (mp == NULL || all_paths == NULL || all_scsi_ids == NULL)
		exit(1);

	if (sysfs_get_mnt_path(conf.sysfs_path, FILE_NAME_SIZE)) {
		get_all_scsi_ids(&conf, all_scsi_ids);
		get_all_paths_nosysfs(&conf, all_paths, all_scsi_ids);
	} else {
		get_all_paths_sysfs(&conf, all_paths);
	}
	nmp = coalesce_paths(&conf, mp, all_paths);

	if (conf.verbose) {
		print_all_path(&conf, all_paths);
		fprintf(stdout, "\n");
		print_all_mp(all_paths, mp, nmp);
		fprintf(stdout, "\n");
	}

	if (conf.dry_run)
		exit(0);

	for (k=0; k<=nmp; k++) {
		if (map_present(mp[k].wwid)) {
			setup_map(&conf, all_paths, mp, k, DM_DEVICE_RELOAD);
		} else {
			setup_map(&conf, all_paths, mp, k, DM_DEVICE_CREATE);
		}
	}

	/* free allocs */
	free(mp);
	free(all_paths);
	free(all_scsi_ids);

	exit(0);
}