devicescan.c

/*
 *  kexecboot - A kexec based bootloader
 *
 *  Copyright (c) 2008-2011 Yuri Bushmelev <jay4mail@gmail.com>
 *  Copyright (c) 2009 Omegamoon <omegamoon@gmail.com>
 *  Copyright (c) 2008 Thomas Kunze <thommycheck@gmx.de>
 *
 *  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, or (at your option)
 *  any later version.
 *
 *  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.
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>

#include "fstype/fstype.h"
#include "util.h"
#include "devicescan.h"
#include "config.h"


/* Create charlist of known filesystems */
struct charlist *scan_filesystems()
{
	char *split;
	struct charlist *fl;
	char line[80];

	fl = create_charlist(8);
	// make a list of all known filesystems
	FILE *f = fopen("/proc/filesystems", "r");

	if (NULL == f) {
		log_msg(lg, "+ can't open /proc/filesystems: %s", ERRMSG);
		free_charlist(fl);
		return NULL;
	}

	while (fgets(line, sizeof(line), f)) {
		line[strlen(line) - 1] = '\0';	/* kill last '\n' */
		split = strchr(line, '\t');
		split++;
		addto_charlist(fl, split);	/* NOTE: strdup() may return NULL */
	}
	fclose(f);
	return fl;
}


/* Allocate bootconf structure */
struct bootconf_t *create_bootcfg(unsigned int size)
{
	struct bootconf_t *bc;

	bc = malloc(sizeof(*bc));
	if (NULL == bc) return NULL;

	bc->list = malloc( size * sizeof(*(bc->list)) );
	if (NULL == bc->list) {
		free(bc);
		return NULL;
	}

	bc->size = size;
	bc->fill = 0;

	bc->timeout = 0;
	bc->default_item = NULL;
	bc->ui = GUI;
	bc->debug = 0;

	return bc;
}

/* Device types */
struct dtypes_t {
	enum dtype_t dtype;
	int device_len;
	char *device;
};

static struct dtypes_t dtypes[] = {
	{ DVT_STORAGE, sizeof("/dev/hd")-1, "/dev/hd" },
	{ DVT_STORAGE, sizeof("/dev/sd")-1, "/dev/sd" },
	{ DVT_MMC, sizeof("/dev/mmcblk")-1, "/dev/mmcblk" },
	{ DVT_MTD, sizeof("/dev/mtdblock")-1, "/dev/mtdblock" },
	{ DVT_UNKNOWN, 0, NULL }
};

/* Import values from cfgdata and boot to bootconf */
int addto_bootcfg(struct bootconf_t *bc, struct device_t *dev,
		struct cfgdata_t *cfgdata)
{
	struct boot_item_t *bi;
	struct dtypes_t *dt;
	int i;
	kx_cfg_section *sc;

	/* Go through all found config file sections */
	for (i = 0; i < cfgdata->count; i++) {
		sc = cfgdata->list[i];
		if (!sc) continue;

		bi = malloc(sizeof(*bi));
		if (NULL == bi) {
			DPRINTF("Can't allocate memory for new bootconf item");
			return -1;
		}

		bi->device = strdup(dev->device);
		bi->fstype = dev->fstype;
		bi->blocks = dev->blocks;

		bi->dtype = DVT_UNKNOWN;
		for (dt = dtypes; dt->dtype != DVT_UNKNOWN; dt++) {
			if ( !strncmp(bi->device, dt->device, dt->device_len) ) {
				bi->dtype = dt->dtype;
			}
		}

		/* Section-dependent data */
		bi->label = sc->label;
		bi->kernelpath = sc->kernelpath;
		bi->cmdline = sc->cmdline;
		bi->initrd = sc->initrd;
		bi->icondata = sc->icondata;
		bi->priority = sc->priority;
		if (sc->is_default) bc->default_item = bi;

		bc->list[bc->fill] = bi;

		if (cfgdata->ui != bc->ui)	bc->ui = cfgdata->ui;
		if (cfgdata->timeout > 0)	bc->timeout = cfgdata->timeout;
		if (cfgdata->debug > 0)		bc->debug = cfgdata->debug;

		++bc->fill;

		/* Resize list when needed */
		if (bc->fill >= bc->size) {
			struct boot_item_t **new_list;

			bc->size <<= 1;	/* size *= 2; */
			new_list = realloc( bc->list, bc->size * sizeof(*(bc->list)) );
			if (NULL == new_list) {
				DPRINTF("Can't resize boot structure");
				return -1;
			}

			bc->list = new_list;
		}

	} /* for */

	return 0;
}


/* Free bootconf structure */
void free_bootcfg(struct bootconf_t *bc)
{
	int i;
	for (i = 0; i < bc->fill; i++) {
		free(bc->list[i]->device);
		free(bc->list[i]->kernelpath);
		dispose(bc->list[i]->cmdline);
		dispose(bc->list[i]->initrd);
		dispose(bc->list[i]->label);
		free(bc->list[i]);
	}
	free(bc->list);
	free(bc);
}


#ifdef DEBUG
void print_bootcfg(struct bootconf_t *bc)
{
	int i;

	log_msg(lg, "== Bootconf (%d, %d)", bc->size, bc->fill);
	log_msg(lg, " + ui: %d", bc->ui);
	log_msg(lg, " + timeout: %d", bc->timeout);
	log_msg(lg, " + debug: %d", bc->debug);

	for (i = 0; i < bc->fill; i++) {
		log_msg(lg, " [%d] device: '%s'", i, bc->list[i]->device);
		log_msg(lg, " [%d] fstype: '%s'", i, bc->list[i]->fstype);
		log_msg(lg, " [%d] blocks: '%lu'", i, bc->list[i]->blocks);
		log_msg(lg, " [%d] label: '%s'", i, bc->list[i]->label);
		log_msg(lg, " [%d] kernelpath: '%s'", i, bc->list[i]->kernelpath);
		log_msg(lg, " [%d] cmdline: '%s'", i, bc->list[i]->cmdline);
		log_msg(lg, " [%d] initrd: '%s'", i, bc->list[i]->initrd);
		log_msg(lg, " [%d] icondata: '%p'", i, bc->list[i]->icondata);
		log_msg(lg, " [%d] priority: '%d'", i, bc->list[i]->priority);
	}
}
#endif


/* Detect FS type on device and returt pointer to static structure from fstype.c */
const char *detect_fstype(char *device, struct charlist *fl)
{
	int fd;
	const char *fstype;

	fd = open(device, O_RDONLY);
	if (fd < 0) {
		log_msg(lg, "+ can't open device: %s", ERRMSG);
		return NULL;
	}

	if ( 0 != identify_fs(fd, &fstype, NULL, 0) ) {
		close(fd);
		log_msg(lg, "+ can't identify FS type");
		return NULL;
	}
	close(fd);

	log_msg(lg, "+ FS type '%s' detected", fstype);

	/* Check that FS is known */
	if (in_charlist(fl, fstype) < 0) {

		/* whitelist 'ubi', we assume it is ubifs */
		if (!strncmp(fstype, "ubi",3)) {
			log_msg(lg, "+ found %s container: assume ubifs", fstype);
		} else {
			log_msg(lg, "+ FS %s is not supported by kernel", fstype);
		return NULL;
		}
	}

	return(fstype);
}


/* Check and parse config file */
int get_bootinfo(struct cfgdata_t *cfgdata)
{
	struct stat sinfo;

	/* Clean cfgdata structure */
	init_cfgdata(cfgdata);

	/* Parse config file */
	if (0 == parse_cfgfile(BOOTCFG_PATH, cfgdata)) {	/* Found and parsed */
		log_msg(lg, "+ config file found");
		/* Check kernel presence
		 * FIXME: we should stat every kernel or shouldn't stat at all
		if (0 == stat(cfgdata->kernelpath, &sinfo)) return 0;

		log_msg(lg, "+ config file points to non-existent kernel");
		return -1;
		*/
		return 0;

	} else {	/* No config file found. Check kernels. */

#ifdef USE_MACHINE_KERNEL
		/* Check machine kernel if set */
		if (NULL != machine_kernel) {
			if (0 == stat(machine_kernel, &sinfo)) {
				cfgdata_add_kernel(cfgdata, machine_kernel);
				log_msg(lg, "+ found machine kernel '%s'", machine_kernel);
				return 0;
			}
		}
#endif

		/* Check default kernels */
		char **kp;
		for (kp = default_kernels; NULL != *kp; kp++) {
			if (0 == stat(*kp, &sinfo)) {
				cfgdata_add_kernel(cfgdata, *kp);
				log_msg(lg, "+ found default kernel '%s'", *kp);
				return 0;
			}
		}
	}

	/* We have no kernels */
	log_msg(lg, "+ no config file nor any kernels found");
	return -1;
}

FILE *devscan_open(struct charlist **fslist)
{
	FILE *f;
	struct charlist *fl;
	char line[80];

    /* Get a list of all filesystems registered in the kernel */
	fl = scan_filesystems();
	if (NULL == fl) {
		return NULL;
	}

	/* Get a list of available partitions on all devices
	 * See kernel/block/genhd.c for details on interface */
	f = fopen("/proc/partitions", "r");
	if (NULL == f) {
		log_msg(lg, "Can't open /proc/partitions: %s", ERRMSG);
		goto free_fl;
	}

	// First two lines are bogus.
	fgets(line, sizeof(line), f);
	fgets(line, sizeof(line), f);

	*fslist = fl;
	return f;

free_fl:
	free_charlist(fl);

	return NULL;
}

int devscan_next(FILE *fp, struct charlist *fslist, struct device_t *dev)
{
	int major, minor, len;
	unsigned long long blocks;
	char *tmp, *p;
	char *device;
	char line[80];

	if (NULL == fgets(line, sizeof(line), fp)) {
		return 0;
	}

	/* Get major, minor, blocks and device name */
	len = 0;
	major = get_nni(line, &p);
	minor = get_nni(p, &p);
	blocks = get_nnll(p, &p, &len);	/* len is used as temp variable */
	tmp = get_word(p, &p);

	if (major < 0 || minor < 0 || NULL == tmp) {
		log_msg(lg, "Can't parse partition string: '%s'", line);
		return -1;
	}

	/* FIXME: 200k is hardcoded below */
	if ((0 == len) && (blocks < 200)) {
		log_msg(lg, "+ device (%d, %d) is too small (%dk < 200k), skipped", major, minor, blocks);
		return -1;
	}

	/* Format device name */
	len = p - tmp;
	device = malloc(len + 5 + 1); /* 5 = strlen("/dev/") */
	if (NULL == device) {
		DPRINTF("Can't allocate memory for device name '%s'", tmp);
		return -1;
	}
	strcpy(device, "/dev/");
	strncat(device, tmp, len);

	log_msg(lg, "Found device '%s' (%d, %d) of size %lluMb",
			device, major, minor, blocks>>10);

#ifdef USE_DEVICES_RECREATING
	/* Remove old device node. We don't care about unlink() result. */
	unlink(device);

	/* Re-create device node */
	log_msg(lg, "+ creating device node");
	if ( -1 == mknod( device,
			(S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH),
			makedev(major, minor) ) )
	{
		log_msg(lg, "+ mknod failed: %s", ERRMSG);
	}
#endif

	dev->fstype = detect_fstype(device, fslist);
	if (NULL == dev->fstype) {
		free(device);
		return -1;
	}

	dev->device = device;
	dev->blocks = blocks;

	return 1;
}