/* vi: set sw=4 ts=4: */
/*
 * devname.c - get a dev by its device inode name
 *
 * Copyright (C) Andries Brouwer
 * Copyright (C) 1999, 2000, 2001, 2002, 2003 Theodore Ts'o
 * Copyright (C) 2001 Andreas Dilger
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the
 * GNU Lesser General Public License.
 * %End-Header%
 */

#include <stdio.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <sys/stat.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_SYS_MKDEV_H
#include <sys/mkdev.h>
#endif
#include <time.h>

#include "blkidP.h"

/*
 * Find a dev struct in the cache by device name, if available.
 *
 * If there is no entry with the specified device name, and the create
 * flag is set, then create an empty device entry.
 */
blkid_dev blkid_get_dev(blkid_cache cache, const char *devname, int flags)
{
        blkid_dev dev = NULL, tmp;
        struct list_head *p;

        if (!cache || !devname)
                return NULL;

        list_for_each(p, &cache->bic_devs) {
                tmp = list_entry(p, struct blkid_struct_dev, bid_devs);
                if (strcmp(tmp->bid_name, devname))
                        continue;

                DBG(DEBUG_DEVNAME,
                    printf("found devname %s in cache\n", tmp->bid_name));
                dev = tmp;
                break;
        }

        if (!dev && (flags & BLKID_DEV_CREATE)) {
                dev = blkid_new_dev();
                if (!dev)
                        return NULL;
                dev->bid_name = blkid_strdup(devname);
                dev->bid_cache = cache;
                list_add_tail(&dev->bid_devs, &cache->bic_devs);
                cache->bic_flags |= BLKID_BIC_FL_CHANGED;
        }

        if (flags & BLKID_DEV_VERIFY)
                dev = blkid_verify(cache, dev);
        return dev;
}

/*
 * Probe a single block device to add to the device cache.
 */
static void probe_one(blkid_cache cache, const char *ptname,
                      dev_t devno, int pri)
{
        blkid_dev dev = NULL;
        struct list_head *p;
        const char **dir;
        char *devname = NULL;

        /* See if we already have this device number in the cache. */
        list_for_each(p, &cache->bic_devs) {
                blkid_dev tmp = list_entry(p, struct blkid_struct_dev,
                                           bid_devs);
                if (tmp->bid_devno == devno) {
                        dev = blkid_verify(cache, tmp);
                        break;
                }
        }
        if (dev && dev->bid_devno == devno)
                goto set_pri;

        /*
         * Take a quick look at /dev/ptname for the device number.  We check
         * all of the likely device directories.  If we don't find it, or if
         * the stat information doesn't check out, use blkid_devno_to_devname()
         * to find it via an exhaustive search for the device major/minor.
         */
        for (dir = blkid_devdirs; *dir; dir++) {
                struct stat st;
                char device[256];

                sprintf(device, "%s/%s", *dir, ptname);
                if ((dev = blkid_get_dev(cache, device, BLKID_DEV_FIND)) &&
                    dev->bid_devno == devno)
                        goto set_pri;

                if (stat(device, &st) == 0 && S_ISBLK(st.st_mode) &&
                    st.st_rdev == devno) {
                        devname = blkid_strdup(device);
                        break;
                }
        }
        if (!devname) {
                devname = blkid_devno_to_devname(devno);
                if (!devname)
                        return;
        }
        dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL);
        free(devname);

set_pri:
        if (!pri && !strncmp(ptname, "md", 2))
                pri = BLKID_PRI_MD;
        if (dev)
                dev->bid_pri = pri;
}

#define PROC_PARTITIONS "/proc/partitions"
#define VG_DIR          "/proc/lvm/VGs"

/*
 * This function initializes the UUID cache with devices from the LVM
 * proc hierarchy.  We currently depend on the names of the LVM
 * hierarchy giving us the device structure in /dev.  (XXX is this a
 * safe thing to do?)
 */
#ifdef VG_DIR
#include <dirent.h>
static dev_t lvm_get_devno(const char *lvm_device)
{
        FILE *lvf;
        char buf[1024];
        int ma, mi;
        dev_t ret = 0;

        DBG(DEBUG_DEVNAME, printf("opening %s\n", lvm_device));
        if ((lvf = fopen_for_read(lvm_device)) == NULL) {
                DBG(DEBUG_DEVNAME, printf("%s: (%d) %s\n", lvm_device, errno,
                                          strerror(errno)));
                return 0;
        }

        while (fgets(buf, sizeof(buf), lvf)) {
                if (sscanf(buf, "device: %d:%d", &ma, &mi) == 2) {
                        ret = makedev(ma, mi);
                        break;
                }
        }
        fclose(lvf);

        return ret;
}

static void lvm_probe_all(blkid_cache cache)
{
        DIR             *vg_list;
        struct dirent   *vg_iter;
        int             vg_len = strlen(VG_DIR);
        dev_t           dev;

        if ((vg_list = opendir(VG_DIR)) == NULL)
                return;

        DBG(DEBUG_DEVNAME, printf("probing LVM devices under %s\n", VG_DIR));

        while ((vg_iter = readdir(vg_list)) != NULL) {
                DIR             *lv_list;
                char            *vdirname;
                char            *vg_name;
                struct dirent   *lv_iter;

                vg_name = vg_iter->d_name;
                if (LONE_CHAR(vg_name, '.') || !strcmp(vg_name, ".."))
                        continue;
                vdirname = xmalloc(vg_len + strlen(vg_name) + 8);
                sprintf(vdirname, "%s/%s/LVs", VG_DIR, vg_name);

                lv_list = opendir(vdirname);
                free(vdirname);
                if (lv_list == NULL)
                        continue;

                while ((lv_iter = readdir(lv_list)) != NULL) {
                        char            *lv_name, *lvm_device;

                        lv_name = lv_iter->d_name;
                        if (LONE_CHAR(lv_name, '.') || !strcmp(lv_name, ".."))
                                continue;

                        lvm_device = xmalloc(vg_len + strlen(vg_name) +
                                            strlen(lv_name) + 8);
                        sprintf(lvm_device, "%s/%s/LVs/%s", VG_DIR, vg_name,
                                lv_name);
                        dev = lvm_get_devno(lvm_device);
                        sprintf(lvm_device, "%s/%s", vg_name, lv_name);
                        DBG(DEBUG_DEVNAME, printf("LVM dev %s: devno 0x%04X\n",
                                                  lvm_device,
                                                  (unsigned int) dev));
                        probe_one(cache, lvm_device, dev, BLKID_PRI_LVM);
                        free(lvm_device);
                }
                closedir(lv_list);
        }
        closedir(vg_list);
}
#endif

#define PROC_EVMS_VOLUMES "/proc/evms/volumes"

static int
evms_probe_all(blkid_cache cache)
{
        char line[100];
        int ma, mi, sz, num = 0;
        FILE *procpt;
        char device[110];

        procpt = fopen_for_read(PROC_EVMS_VOLUMES);
        if (!procpt)
                return 0;
        while (fgets(line, sizeof(line), procpt)) {
                if (sscanf(line, " %d %d %d %*s %*s %[^\n ]",
                            &ma, &mi, &sz, device) != 4)
                        continue;

                DBG(DEBUG_DEVNAME, printf("Checking partition %s (%d, %d)\n",
                                          device, ma, mi));

                probe_one(cache, device, makedev(ma, mi), BLKID_PRI_EVMS);
                num++;
        }
        fclose(procpt);
        return num;
}

/*
 * Read the device data for all available block devices in the system.
 */
int blkid_probe_all(blkid_cache cache)
{
        FILE *proc;
        char line[1024];
        char ptname0[128], ptname1[128], *ptname = NULL;
        char *ptnames[2];
        dev_t devs[2];
        int ma, mi;
        unsigned long long sz;
        int lens[2] = { 0, 0 };
        int which = 0, last = 0;

        ptnames[0] = ptname0;
        ptnames[1] = ptname1;

        if (!cache)
                return -BLKID_ERR_PARAM;

        if (cache->bic_flags & BLKID_BIC_FL_PROBED &&
            time(NULL) - cache->bic_time < BLKID_PROBE_INTERVAL)
                return 0;

        blkid_read_cache(cache);
        evms_probe_all(cache);
#ifdef VG_DIR
        lvm_probe_all(cache);
#endif

        proc = fopen_for_read(PROC_PARTITIONS);
        if (!proc)
                return -BLKID_ERR_PROC;

        while (fgets(line, sizeof(line), proc)) {
                last = which;
                which ^= 1;
                ptname = ptnames[which];

                if (sscanf(line, " %d %d %llu %128[^\n ]",
                           &ma, &mi, &sz, ptname) != 4)
                        continue;
                devs[which] = makedev(ma, mi);

                DBG(DEBUG_DEVNAME, printf("read partition name %s\n", ptname));

                /* Skip whole disk devs unless they have no partitions
                 * If we don't have a partition on this dev, also
                 * check previous dev to see if it didn't have a partn.
                 * heuristic: partition name ends in a digit.
                 *
                 * Skip extended partitions.
                 * heuristic: size is 1
                 *
                 * FIXME: skip /dev/{ida,cciss,rd} whole-disk devs
                 */

                lens[which] = strlen(ptname);
                if (isdigit(ptname[lens[which] - 1])) {
                        DBG(DEBUG_DEVNAME,
                            printf("partition dev %s, devno 0x%04X\n",
                                   ptname, (unsigned int) devs[which]));

                        if (sz > 1)
                                probe_one(cache, ptname, devs[which], 0);
                        lens[which] = 0;
                        lens[last] = 0;
                } else if (lens[last] && strncmp(ptnames[last], ptname,
                                                 lens[last])) {
                        DBG(DEBUG_DEVNAME,
                            printf("whole dev %s, devno 0x%04X\n",
                                   ptnames[last], (unsigned int) devs[last]));
                        probe_one(cache, ptnames[last], devs[last], 0);
                        lens[last] = 0;
                }
        }

        /* Handle the last device if it wasn't partitioned */
        if (lens[which])
                probe_one(cache, ptname, devs[which], 0);

        fclose(proc);

        cache->bic_time = time(NULL);
        cache->bic_flags |= BLKID_BIC_FL_PROBED;
        blkid_flush_cache(cache);
        return 0;
}

#ifdef TEST_PROGRAM
int main(int argc, char **argv)
{
        blkid_cache cache = NULL;
        int ret;

        blkid_debug_mask = DEBUG_ALL;
        if (argc != 1) {
                fprintf(stderr, "Usage: %s\n"
                        "Probe all devices and exit\n", argv[0]);
                exit(1);
        }
        if ((ret = blkid_get_cache(&cache, bb_dev_null)) != 0) {
                fprintf(stderr, "%s: error creating cache (%d)\n",
                        argv[0], ret);
                exit(1);
        }
        if (blkid_probe_all(cache) < 0)
                printf("%s: error probing devices\n", argv[0]);

        blkid_put_cache(cache);
        return 0;
}
#endif