#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <limits.h>

/*
 * Original work by Jeff Garzik
 *
 * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
 */

#define xstr(s) #s
#define str(s) xstr(s)

static unsigned int offset;
static unsigned int ino = 721;

struct file_handler {
        const char *type;
        int (*handler)(const char *line);
};

static void push_string(const char *name)
{
        unsigned int name_len = strlen(name) + 1;

        fputs(name, stdout);
        putchar(0);
        offset += name_len;
}

static void push_pad (void)
{
        while (offset & 3) {
                putchar(0);
                offset++;
        }
}

static void push_rest(const char *name)
{
        unsigned int name_len = strlen(name) + 1;
        unsigned int tmp_ofs;

        fputs(name, stdout);
        putchar(0);
        offset += name_len;

        tmp_ofs = name_len + 110;
        while (tmp_ofs & 3) {
                putchar(0);
                offset++;
                tmp_ofs++;
        }
}

static void push_hdr(const char *s)
{
        fputs(s, stdout);
        offset += 110;
}

static void cpio_trailer(void)
{
        char s[256];
        const char name[] = "TRAILER!!!";

        sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
               "%08X%08X%08X%08X%08X%08X%08X",
                "070701",               /* magic */
                0,                      /* ino */
                0,                      /* mode */
                (long) 0,               /* uid */
                (long) 0,               /* gid */
                1,                      /* nlink */
                (long) 0,               /* mtime */
                0,                      /* filesize */
                0,                      /* major */
                0,                      /* minor */
                0,                      /* rmajor */
                0,                      /* rminor */
                (unsigned)strlen(name)+1, /* namesize */
                0);                     /* chksum */
        push_hdr(s);
        push_rest(name);

        while (offset % 512) {
                putchar(0);
                offset++;
        }
}

static int cpio_mkslink(const char *name, const char *target,
                         unsigned int mode, uid_t uid, gid_t gid)
{
        char s[256];
        time_t mtime = time(NULL);

        sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
               "%08X%08X%08X%08X%08X%08X%08X",
                "070701",               /* magic */
                ino++,                  /* ino */
                S_IFLNK | mode,         /* mode */
                (long) uid,             /* uid */
                (long) gid,             /* gid */
                1,                      /* nlink */
                (long) mtime,           /* mtime */
                (unsigned)strlen(target)+1, /* filesize */
                3,                      /* major */
                1,                      /* minor */
                0,                      /* rmajor */
                0,                      /* rminor */
                (unsigned)strlen(name) + 1,/* namesize */
                0);                     /* chksum */
        push_hdr(s);
        push_string(name);
        push_pad();
        push_string(target);
        push_pad();
        return 0;
}

static int cpio_mkslink_line(const char *line)
{
        char name[PATH_MAX + 1];
        char target[PATH_MAX + 1];
        unsigned int mode;
        int uid;
        int gid;
        int rc = -1;

        if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
                fprintf(stderr, "Unrecognized dir format '%s'", line);
                goto fail;
        }
        rc = cpio_mkslink(name, target, mode, uid, gid);
 fail:
        return rc;
}

static int cpio_mkgeneric(const char *name, unsigned int mode,
                       uid_t uid, gid_t gid)
{
        char s[256];
        time_t mtime = time(NULL);

        sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
               "%08X%08X%08X%08X%08X%08X%08X",
                "070701",               /* magic */
                ino++,                  /* ino */
                mode,                   /* mode */
                (long) uid,             /* uid */
                (long) gid,             /* gid */
                2,                      /* nlink */
                (long) mtime,           /* mtime */
                0,                      /* filesize */
                3,                      /* major */
                1,                      /* minor */
                0,                      /* rmajor */
                0,                      /* rminor */
                (unsigned)strlen(name) + 1,/* namesize */
                0);                     /* chksum */
        push_hdr(s);
        push_rest(name);
        return 0;
}

enum generic_types {
        GT_DIR,
        GT_PIPE,
        GT_SOCK
};

struct generic_type {
        const char *type;
        mode_t mode;
};

static struct generic_type generic_type_table[] = {
        [GT_DIR] = {
                .type = "dir",
                .mode = S_IFDIR
        },
        [GT_PIPE] = {
                .type = "pipe",
                .mode = S_IFIFO
        },
        [GT_SOCK] = {
                .type = "sock",
                .mode = S_IFSOCK
        }
};

static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
{
        char name[PATH_MAX + 1];
        unsigned int mode;
        int uid;
        int gid;
        int rc = -1;

        if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
                fprintf(stderr, "Unrecognized %s format '%s'",
                        line, generic_type_table[gt].type);
                goto fail;
        }
        mode |= generic_type_table[gt].mode;
        rc = cpio_mkgeneric(name, mode, uid, gid);
 fail:
        return rc;
}

static int cpio_mkdir_line(const char *line)
{
        return cpio_mkgeneric_line(line, GT_DIR);
}

static int cpio_mkpipe_line(const char *line)
{
        return cpio_mkgeneric_line(line, GT_PIPE);
}

static int cpio_mksock_line(const char *line)
{
        return cpio_mkgeneric_line(line, GT_SOCK);
}

static int cpio_mknod(const char *name, unsigned int mode,
                       uid_t uid, gid_t gid, char dev_type,
                       unsigned int maj, unsigned int min)
{
        char s[256];
        time_t mtime = time(NULL);

        if (dev_type == 'b')
                mode |= S_IFBLK;
        else
                mode |= S_IFCHR;

        sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
               "%08X%08X%08X%08X%08X%08X%08X",
                "070701",               /* magic */
                ino++,                  /* ino */
                mode,                   /* mode */
                (long) uid,             /* uid */
                (long) gid,             /* gid */
                1,                      /* nlink */
                (long) mtime,           /* mtime */
                0,                      /* filesize */
                3,                      /* major */
                1,                      /* minor */
                maj,                    /* rmajor */
                min,                    /* rminor */
                (unsigned)strlen(name) + 1,/* namesize */
                0);                     /* chksum */
        push_hdr(s);
        push_rest(name);
        return 0;
}

static int cpio_mknod_line(const char *line)
{
        char name[PATH_MAX + 1];
        unsigned int mode;
        int uid;
        int gid;
        char dev_type;
        unsigned int maj;
        unsigned int min;
        int rc = -1;

        if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
                         name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
                fprintf(stderr, "Unrecognized nod format '%s'", line);
                goto fail;
        }
        rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
 fail:
        return rc;
}

/* Not marked static to keep the compiler quiet, as no one uses this yet... */
static int cpio_mkfile(const char *name, const char *location,
                        unsigned int mode, uid_t uid, gid_t gid)
{
        char s[256];
        char *filebuf = NULL;
        struct stat buf;
        int file = -1;
        int retval;
        int rc = -1;

        mode |= S_IFREG;

        retval = stat (location, &buf);
        if (retval) {
                fprintf (stderr, "File %s could not be located\n", location);
                goto error;
        }

        file = open (location, O_RDONLY);
        if (file < 0) {
                fprintf (stderr, "File %s could not be opened for reading\n", location);
                goto error;
        }

        filebuf = malloc(buf.st_size);
        if (!filebuf) {
                fprintf (stderr, "out of memory\n");
                goto error;
        }

        retval = read (file, filebuf, buf.st_size);
        if (retval < 0) {
                fprintf (stderr, "Can not read %s file\n", location);
                goto error;
        }

        sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
               "%08X%08X%08X%08X%08X%08X%08X",
                "070701",               /* magic */
                ino++,                  /* ino */
                mode,                   /* mode */
                (long) uid,             /* uid */
                (long) gid,             /* gid */
                1,                      /* nlink */
                (long) buf.st_mtime,    /* mtime */
                (int) buf.st_size,      /* filesize */
                3,                      /* major */
                1,                      /* minor */
                0,                      /* rmajor */
                0,                      /* rminor */
                (unsigned)strlen(name) + 1,/* namesize */
                0);                     /* chksum */
        push_hdr(s);
        push_string(name);
        push_pad();

        fwrite(filebuf, buf.st_size, 1, stdout);
        offset += buf.st_size;
        push_pad();
        rc = 0;
        
error:
        if (filebuf) free(filebuf);
        if (file >= 0) close(file);
        return rc;
}

static int cpio_mkfile_line(const char *line)
{
        char name[PATH_MAX + 1];
        char location[PATH_MAX + 1];
        unsigned int mode;
        int uid;
        int gid;
        int rc = -1;

        if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, location, &mode, &uid, &gid)) {
                fprintf(stderr, "Unrecognized file format '%s'", line);
                goto fail;
        }
        rc = cpio_mkfile(name, location, mode, uid, gid);
 fail:
        return rc;
}

void usage(const char *prog)
{
        fprintf(stderr, "Usage:\n"
                "\t%s <cpio_list>\n"
                "\n"
                "<cpio_list> is a file containing newline separated entries that\n"
                "describe the files to be included in the initramfs archive:\n"
                "\n"
                "# a comment\n"
                "file <name> <location> <mode> <uid> <gid>\n"
                "dir <name> <mode> <uid> <gid>\n"
                "nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
                "slink <name> <target> <mode> <uid> <gid>\n"
                "pipe <name> <mode> <uid> <gid>\n"
                "sock <name> <mode> <uid> <gid>\n"
                "\n"
                "<name>      name of the file/dir/nod/etc in the archive\n"
                "<location>  location of the file in the current filesystem\n"
                "<target>    link target\n"
                "<mode>      mode/permissions of the file\n"
                "<uid>       user id (0=root)\n"
                "<gid>       group id (0=root)\n"
                "<dev_type>  device type (b=block, c=character)\n"
                "<maj>       major number of nod\n"
                "<min>       minor number of nod\n"
                "\n"
                "example:\n"
                "# A simple initramfs\n"
                "dir /dev 0755 0 0\n"
                "nod /dev/console 0600 0 0 c 5 1\n"
                "dir /root 0700 0 0\n"
                "dir /sbin 0755 0 0\n"
                "file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n",
                prog);
}

struct file_handler file_handler_table[] = {
        {
                .type    = "file",
                .handler = cpio_mkfile_line,
        }, {
                .type    = "nod",
                .handler = cpio_mknod_line,
        }, {
                .type    = "dir",
                .handler = cpio_mkdir_line,
        }, {
                .type    = "slink",
                .handler = cpio_mkslink_line,
        }, {
                .type    = "pipe",
                .handler = cpio_mkpipe_line,
        }, {
                .type    = "sock",
                .handler = cpio_mksock_line,
        }, {
                .type    = NULL,
                .handler = NULL,
        }
};

#define LINE_SIZE (2 * PATH_MAX + 50)

int main (int argc, char *argv[])
{
        FILE *cpio_list;
        char line[LINE_SIZE];
        char *args, *type;
        int ec = 0;
        int line_nr = 0;

        if (2 != argc) {
                usage(argv[0]);
                exit(1);
        }

        if (! (cpio_list = fopen(argv[1], "r"))) {
                fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
                        argv[1], strerror(errno));
                usage(argv[0]);
                exit(1);
        }

        while (fgets(line, LINE_SIZE, cpio_list)) {
                int type_idx;
                size_t slen = strlen(line);

                line_nr++;

                if ('#' == *line) {
                        /* comment - skip to next line */
                        continue;
                }

                if (! (type = strtok(line, " \t"))) {
                        fprintf(stderr,
                                "ERROR: incorrect format, could not locate file type line %d: '%s'\n",
                                line_nr, line);
                        ec = -1;
                        break;
                }

                if ('\n' == *type) {
                        /* a blank line */
                        continue;
                }

                if (slen == strlen(type)) {
                        /* must be an empty line */
                        continue;
                }

                if (! (args = strtok(NULL, "\n"))) {
                        fprintf(stderr,
                                "ERROR: incorrect format, newline required line %d: '%s'\n",
                                line_nr, line);
                        ec = -1;
                }

                for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
                        int rc;
                        if (! strcmp(line, file_handler_table[type_idx].type)) {
                                if ((rc = file_handler_table[type_idx].handler(args))) {
                                        ec = rc;
                                        fprintf(stderr, " line %d\n", line_nr);
                                }
                                break;
                        }
                }

                if (NULL == file_handler_table[type_idx].type) {
                        fprintf(stderr, "unknown file type line %d: '%s'\n",
                                line_nr, line);
                }
        }
        if (ec == 0)
                cpio_trailer();

        exit(ec);
}