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/**************************************************************/
/* tpax: a topological pax implementation */
/* Copyright (C) 2020--2024 SysDeer Technologies, LLC */
/* Released under GPLv2 and GPLv3; see COPYING.TPAX. */
/**************************************************************/
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <grp.h>
#include <pwd.h>
#include <sys/stat.h>
#include <tpax/tpax.h>
#include <tpax/tpax_specs.h>
#include "tpax_driver_impl.h"
#ifndef ssizeof
#define ssizeof(x) (ssize_t)(sizeof(x))
#endif
#define TPAX_CPIO_PERM_MASK \
( S_ISUID | S_ISGID \
| S_IRUSR | S_IWUSR | S_IXUSR \
| S_IRGRP | S_IWGRP | S_IXGRP \
| S_IROTH | S_IWOTH | S_IXOTH )
static void tpax_octal_write(char * ch, ssize_t len, uint64_t val)
{
for (; len; ) {
ch[--len] = val % 8 + '0';
val /= 8;
}
}
int tpax_meta_init_cpio_header(
const char * path,
const struct stat * st,
const char * linkname,
int cdev,
int cino,
int cnlink,
struct tpax_cpio_header * chdr)
{
size_t fnsize;
size_t lnklen;
size_t stsize;
int64_t stmtim;
uint32_t typeflag;
uint32_t permbits;
uint32_t modebits;
/* filename size */
fnsize = strlen(path) + 1;
/* size & mtime validation */
stsize = S_ISREG(st->st_mode) ? st->st_size : 0;
stmtim = st->st_mtim.tv_sec;
if (stsize > 077777777777)
return -1;
if ((stmtim < 0) || (stmtim > 077777777777))
return -1;
/* linkname validation */
if (S_ISLNK(st->st_mode) && !linkname)
return -1;
lnklen = S_ISLNK(st->st_mode)
? strlen(linkname)
: 0;
/* typeflag validation */
if (S_ISREG(st->st_mode))
typeflag = TPAX_CPIO_FILEMODE_ISREG;
else if (S_ISLNK(st->st_mode))
typeflag = TPAX_CPIO_FILEMODE_ISLNK;
else if (S_ISDIR(st->st_mode))
typeflag = TPAX_CPIO_FILEMODE_ISDIR;
else if (S_ISCHR(st->st_mode))
typeflag = TPAX_CPIO_FILEMODE_ISCHR;
else if (S_ISBLK(st->st_mode))
typeflag = TPAX_CPIO_FILEMODE_ISBLK;
else if (S_ISFIFO(st->st_mode))
typeflag = TPAX_CPIO_FILEMODE_ISFIFO;
else if (S_ISSOCK(st->st_mode))
typeflag = TPAX_CPIO_FILEMODE_ISSOCK;
else
return -1;
/* permbits, modeflag */
permbits = st->st_mode & TPAX_CPIO_PERM_MASK;
modebits = permbits | typeflag;
/* one shot */
memset(chdr,0,sizeof(*chdr));
/* c_magic */
chdr->c_magic[0] = '0';
chdr->c_magic[1] = '7';
chdr->c_magic[2] = '0';
chdr->c_magic[3] = '7';
chdr->c_magic[4] = '0';
chdr->c_magic[5] = '7';
/* c_dev, c_ino */
tpax_octal_write(chdr->c_dev,ssizeof(chdr->c_dev),cdev);
tpax_octal_write(chdr->c_ino,ssizeof(chdr->c_ino),cino);
/* c_mode */
tpax_octal_write(chdr->c_mode,ssizeof(chdr->c_mode),modebits);
/* c_uid, c_gid */
if ((uint64_t)st->st_uid <= 0777777)
tpax_octal_write(chdr->c_uid,ssizeof(chdr->c_uid),st->st_uid);
else
tpax_octal_write(chdr->c_uid,ssizeof(chdr->c_uid),0);
if ((uint64_t)st->st_gid <= 0777777)
tpax_octal_write(chdr->c_gid,ssizeof(chdr->c_gid),st->st_gid);
else
tpax_octal_write(chdr->c_gid,ssizeof(chdr->c_gid),0);
/* c_nlink */
tpax_octal_write(chdr->c_nlink,ssizeof(chdr->c_nlink),cnlink);
/* c_rdev */
tpax_octal_write(chdr->c_rdev,ssizeof(chdr->c_rdev),st->st_rdev);
/* c_mtime */
tpax_octal_write(chdr->c_mtime,ssizeof(chdr->c_mtime),stmtim);
/* c_namesize */
tpax_octal_write(chdr->c_namesize,ssizeof(chdr->c_namesize),fnsize);
/* c_filesize */
tpax_octal_write(chdr->c_filesize,ssizeof(chdr->c_filesize),lnklen ? lnklen : stsize);
/* all done; c_name to be written along with c_filedata */
return 0;
}
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