/*
 * File system mapping
 */

#include <unistd.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/vfs.h>
#include <sys/statvfs.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include <linux/fs.h>

static dev_t root_dev;
static long  root_blksize;
static long  root_fblksize;
static long  root_blocks;
static long  root_bfree;

void
init_root_dev(void)
{
    struct stat sbuf;
    struct statvfs vfsbuf;
    int fd;
    int ret;

    ret = stat("/", &sbuf);
    if (ret != 0) {
        fprintf(stderr, "Failed to stat /\n");
	exit(1);
    }
    root_dev = sbuf.st_dev;
    fd = open("/", O_RDONLY);
    if (fd == -1) {
        fprintf(stderr, "Failed to read /\n");
        exit(1);
    }
    if (fstatvfs(fd, &vfsbuf) < 0) {
        fprintf(stderr, "Failed to statfs /\n");
        exit(1);
    }
    root_blksize = vfsbuf.f_bsize;
    root_fblksize = vfsbuf.f_frsize;
    root_blocks = vfsbuf.f_blocks;
    root_bfree = vfsbuf.f_bfree;

    close(fd);
    /*
    printf("/ : %lu data %lu free KB\n",
           root_blocks * (root_fblksize / 1024),
           root_bfree * (root_fblksize / 1024));
     */
    printf("  <filesystem name='/' dev='%X' blksize='%lu' fragsize='%lu'\n",
           root_dev, root_blksize, root_fblksize);
    printf("              size='%lu' free='%lu' avail='%lu'/>\n",
           root_blocks * (root_fblksize / 1024),
	   root_bfree * (root_fblksize / 1024),
	   vfsbuf.f_bavail * (root_blksize / 1024));

}

int
dump_file(const char *path)
{
    int ret, i, err = 0;
    int fd;
    long blksize;
    off_t filesz;
    long fileblks, blk;
    long start = -1, end = -1;
    long first_logical = -1;
    struct stat sbuf;

    blksize = root_blksize;

    fd = open(path, O_RDONLY);
    if (fd == -1) {
        return(1);
    }
    ret = fstat(fd, &sbuf);
    if (ret < 0) {
        close(fd);
        return(1);
    }

    printf("  <file name='%s' size='%lu'>\n", path, sbuf.st_size);
    if (sbuf.st_dev != root_dev) {
        close(fd);
        printf("  </file>\n");
	return(1);
    }

    filesz = sbuf.st_size;
    fileblks = (filesz + root_blksize - 1) / root_blksize;

    err = 0;
    for (blk = 0; blk < fileblks; blk++) {
        long devblk = blk;

        if (ioctl(fd, FIBMAP, &devblk) == -1) {
            if (errno == -EPERM) {
                close(fd);
                return(1);
            }
            err++;
        } else {
            if (start == -1) {
                start = devblk;
                end = devblk;
                first_logical = blk;
            } else {
                if (devblk == end + 1) {
                    end++;
                } else {
		    printf("    <blk at='%d' nb='%d' start='%lu' end='%lu'/>\n",
		           first_logical, end - start + 1, start, end);
	            /*
                    printf("%ld-%ld: %ld-%ld (%ld)\n",
                           first_logical,
                           first_logical + (end - start),
                           start, end, end - start + 1);
	             */
                    start = devblk;
                    end = devblk;
                    first_logical = blk;
                }
            }
        }
    }

    if (start != -1) {
        /* 
        printf("%ld-%ld: %ld-%ld (%ld)\n",
               first_logical,
               first_logical + (end - start), start, end, end - start + 1);
	 */
	printf("    <blk at='%lu' nb='%d' start='%lu' end='%lu'/>\n",
	       first_logical, end - start + 1, start, end);
    }

    close(fd);
    printf("  </file>\n");
    return(err);
}

void
usage(const char *name)
{
    fprintf(stderr, "Usage: %s file(s)...\n", name);
    fprintf(stderr, "    or %s --list filelist\n", name);
}

#define IS_BLANK(p) ((*(p) == ' ') || (*(p) == '\t') ||		\
                     (*(p) == '\n') || (*(p) == '\r'))

int
main(int argc, char **argv)
{
    int i;
    int err = 0;

    if (argc < 2) {
        usage(argv[0]);
        exit(2);
    }
    if (strcmp(argv[1], "--list") == 0) {
        FILE *f;
	char *filename = argv[2], *cur;
	char filepath[4096 + 201];

        if (filename == NULL) {
	    usage(argv[0]);
	    exit(2);
	}
	if (strcmp(filename, "-")) {
	    f = fopen(filename, "r");
	} else {
	    f = fdopen(0, "r");
	}
	if (f == NULL) {
	    fprintf(stderr, "Unable to read %s\n", filename);
	    exit(1);
	}
	printf("<mapfs>\n");
	init_root_dev();
	while (fgets(filepath, 4096 + 200, f)) {
	    filename = filepath;
	    while (IS_BLANK(filename)) filename++;
	    if (*filename == 0) continue;
            cur = filename;
	    while ((*cur != 0) && (!IS_BLANK(cur))) cur++;
	    *cur = 0;
	    err += dump_file(filename);
	}
	printf("</mapfs>\n");
	fclose(f);
    } else {
	printf("<mapfs>\n");
	init_root_dev();
	for (i = 1;i < argc;i++) {
	    err += dump_file(argv[i]);
	}
	printf("</mapfs>\n");
    }
    exit(err ? 1 : 0);
}