/*-
* Copyright (c) 2007-2014, Juniper Networks, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "stand.h"
#include <sys/stat.h>
#include <sys/stdint.h>
#include <string.h>
#include <zlib.h>
#ifdef PKGFS_DEBUG
#define DBG(x) printf x
#else
#define DBG(x)
#endif
static int pkg_open(const char *, struct open_file *);
static int pkg_close(struct open_file *);
static int pkg_read(struct open_file *, void *, size_t, size_t *);
static off_t pkg_seek(struct open_file *, off_t, int);
static int pkg_stat(struct open_file *, struct stat *);
static int pkg_readdir(struct open_file *, struct dirent *);
static off_t pkg_atol(const char *, unsigned);
struct fs_ops pkgfs_fsops = {
"pkg",
pkg_open,
pkg_close,
pkg_read,
null_write,
pkg_seek,
pkg_stat,
pkg_readdir
};
#define PKG_BUFSIZE 512
#define PKG_MAXCACHESZ (512 * 1024)
#define PKG_FILEEXT ".tgz"
/*
* Layout of POSIX 'ustar' header.
*/
struct ustar_hdr {
char ut_name[100];
char ut_mode[8];
char ut_uid[8];
char ut_gid[8];
char ut_size[12];
char ut_mtime[12];
char ut_checksum[8];
char ut_typeflag[1];
char ut_linkname[100];
char ut_magic[6]; /* For POSIX: "ustar\0" */
char ut_version[2]; /* For POSIX: "00" */
char ut_uname[32];
char ut_gname[32];
char ut_rdevmajor[8];
char ut_rdevminor[8];
union {
struct {
char prefix[155];
} posix;
struct {
char atime[12];
char ctime[12];
char offset[12];
char longnames[4];
char unused[1];
struct gnu_sparse {
char offset[12];
char numbytes[12];
} sparse[4];
char isextended[1];
char realsize[12];
} gnu;
} u;
u_char __padding[12];
};
struct package;
struct tarfile
{
struct package *tf_pkg;
struct tarfile *tf_next;
struct ustar_hdr tf_hdr;
off_t tf_ofs;
off_t tf_size;
off_t tf_fp;
size_t tf_cachesz;
void *tf_cache;
};
struct package
{
struct package *pkg_chain;
int pkg_fd;
off_t pkg_ofs;
z_stream pkg_zs;
struct tarfile *pkg_first;
struct tarfile *pkg_last;
u_char pkg_buf[PKG_BUFSIZE];
};
static struct package *package = NULL;
static int new_package(int, struct package **);
static int cache_data(struct tarfile *tf, int);
void
pkgfs_cleanup(void)
{
struct package *chain;
struct tarfile *tf, *tfn;
while (package != NULL) {
inflateEnd(&package->pkg_zs);
close(package->pkg_fd);
tf = package->pkg_first;
while (tf != NULL) {
tfn = tf->tf_next;
if (tf->tf_cachesz > 0)
free(tf->tf_cache);
free(tf);
tf = tfn;
}
chain = package->pkg_chain;
free(package);
package = chain;
}
}
int
pkgfs_init(const char *pkgname, struct fs_ops *proto)
{
struct package *pkg;
int error, fd;
pkg = NULL;
if (proto != &pkgfs_fsops)
pkgfs_cleanup();
exclusive_file_system = proto;
fd = open(pkgname, O_RDONLY);
exclusive_file_system = NULL;
if (fd == -1)
return (errno);
error = new_package(fd, &pkg);
if (error) {
close(fd);
return (error);
}
if (pkg == NULL)
return (EDOOFUS);
pkg->pkg_chain = package;
package = pkg;
exclusive_file_system = &pkgfs_fsops;
return (0);
}
static int get_mode(struct tarfile *);
static int get_zipped(struct package *, void *, size_t);
static int new_package(int, struct package **);
static struct tarfile *scan_tarfile(struct package *, struct tarfile *);
static int
pkg_open_follow(const char *fn, struct open_file *f, int lnks)
{
struct tarfile *tf;
if (fn == NULL || f == NULL)
return (EINVAL);
if (package == NULL)
return (ENXIO);
/*
* We can only read from a package, so reject request to open
* for write-only or read-write.
*/
if (f->f_flags != F_READ)
return (EPERM);
/*
* Scan the file headers for the named file. We stop scanning
* at the first filename that has the .pkg extension. This is
* a package within a package. We assume we have all the files
* we need up-front and without having to dig within nested
* packages.
*
* Note that we preserve streaming properties as much as possible.
*/
while (*fn == '/')
fn++;
/*
* Allow opening of the root directory for use by readdir()
* to support listing files in the package.
*/
if (*fn == '\0') {
f->f_fsdata = NULL;
return (0);
}
tf = scan_tarfile(package, NULL);
while (tf != NULL) {
if (strcmp(fn, tf->tf_hdr.ut_name) == 0) {
f->f_fsdata = tf;
tf->tf_fp = 0; /* Reset the file pointer. */
DBG(("%s: found %s type %c\n", __func__,
fn, tf->tf_hdr.ut_typeflag[0]));
if (tf->tf_hdr.ut_typeflag[0] == '2') {
/* we have a symlink
* Note: ut_linkname is only 100 chars!
*/
if (lnks++ >= 8)
return (EMLINK);
return pkg_open_follow(tf->tf_hdr.ut_linkname,
f, lnks);
}
return (0);
}
tf = scan_tarfile(package, tf);
}
return (errno);
}
static int
pkg_open(const char *fn, struct open_file *f)
{
return pkg_open_follow(fn, f, 0);
}
static int
pkg_close(struct open_file *f)
{
struct tarfile *tf;
tf = (struct tarfile *)f->f_fsdata;
if (tf == NULL)
return (0);
/*
* Free up the cache if we read all of the file.
*/
if (tf->tf_fp == tf->tf_size && tf->tf_cachesz > 0) {
free(tf->tf_cache);
tf->tf_cachesz = 0;
}
return (0);
}
static int
pkg_read(struct open_file *f, void *buf, size_t size, size_t *res)
{
struct tarfile *tf;
char *p;
off_t fp;
size_t sz;
tf = (struct tarfile *)f->f_fsdata;
if (tf == NULL) {
if (res != NULL)
*res = size;
return (EBADF);
}
if (tf->tf_cachesz == 0)
cache_data(tf, 1);
fp = tf->tf_fp;
p = buf;
sz = 0;
while (size > 0) {
sz = tf->tf_size - fp;
if (fp < tf->tf_cachesz && tf->tf_cachesz < tf->tf_size)
sz = tf->tf_cachesz - fp;
if (size < sz)
sz = size;
if (sz == 0)
break;
if (fp < tf->tf_cachesz) {
/* Satisfy the request from cache. */
memcpy(p, tf->tf_cache + fp, sz);
fp += sz;
p += sz;
size -= sz;
continue;
}
if (get_zipped(tf->tf_pkg, p, sz) == -1) {
sz = -1;
break;
}
fp += sz;
p += sz;
size -= sz;
}
tf->tf_fp = fp;
if (res != NULL)
*res = size;
return ((sz == -1) ? errno : 0);
}
static off_t
pkg_seek(struct open_file *f, off_t ofs, int whence)
{
char buf[512];
struct tarfile *tf;
off_t delta;
off_t nofs;
size_t sz, res;
int error;
tf = (struct tarfile *)f->f_fsdata;
if (tf == NULL) {
errno = EBADF;
return (-1);
}
switch (whence) {
case SEEK_SET:
delta = ofs - tf->tf_fp;
break;
case SEEK_CUR:
delta = ofs;
break;
case SEEK_END:
delta = tf->tf_size - tf->tf_fp + ofs;
break;
default:
errno = EINVAL;
return (-1);
}
if (delta < 0) {
/* seeking backwards - ok if within cache */
if (tf->tf_cachesz > 0 && tf->tf_fp <= tf->tf_cachesz) {
nofs = tf->tf_fp + delta;
if (nofs >= 0) {
tf->tf_fp = nofs;
return (tf->tf_fp);
}
}
DBG(("%s: negative file seek (%jd)\n", __func__,
(intmax_t)delta));
errno = ESPIPE;
return (-1);
}
while (delta > 0 && tf->tf_fp < tf->tf_size) {
sz = (delta > sizeof(buf)) ? sizeof(buf) : delta;
error = pkg_read(f, buf, sz, &res);
if (error != 0) {
errno = error;
return (-1);
}
delta -= sz - res;
}
return (tf->tf_fp);
}
static int
pkg_stat(struct open_file *f, struct stat *sb)
{
struct tarfile *tf;
tf = (struct tarfile *)f->f_fsdata;
if (tf == NULL)
return (EBADF);
memset(sb, 0, sizeof(*sb));
sb->st_mode = get_mode(tf);
if ((sb->st_mode & S_IFMT) == 0) {
/* tar file bug - assume regular file */
sb->st_mode |= S_IFREG;
}
sb->st_size = tf->tf_size;
sb->st_blocks = (tf->tf_size + 511) / 512;
sb->st_mtime = pkg_atol(tf->tf_hdr.ut_mtime, 12);
sb->st_dev = (off_t)((uintptr_t)tf->tf_pkg);
sb->st_ino = tf->tf_ofs; /* unique per tf_pkg */
return (0);
}
static int
pkg_readdir(struct open_file *f, struct dirent *d)
{
struct tarfile *tf;
tf = (struct tarfile *)f->f_fsdata;
if (tf != NULL)
return (EBADF);
tf = scan_tarfile(package, NULL);
if (tf == NULL)
return (ENOENT);
d->d_fileno = 0;
d->d_reclen = sizeof(*d);
d->d_type = DT_REG;
memcpy(d->d_name, tf->tf_hdr.ut_name, sizeof(d->d_name));
return (0);
}
/*
* Low-level support functions.
*/
static int
get_byte(struct package *pkg, off_t *op)
{
int c;
if (pkg->pkg_zs.avail_in == 0) {
c = read(pkg->pkg_fd, pkg->pkg_buf, PKG_BUFSIZE);
if (c <= 0)
return (-1);
pkg->pkg_zs.avail_in = c;
pkg->pkg_zs.next_in = pkg->pkg_buf;
}
c = *pkg->pkg_zs.next_in;
pkg->pkg_zs.next_in++;
pkg->pkg_zs.avail_in--;
(*op)++;
return (c);
}
static int
get_zipped(struct package *pkg, void *buf, size_t bufsz)
{
int c;
pkg->pkg_zs.next_out = buf;
pkg->pkg_zs.avail_out = bufsz;
while (pkg->pkg_zs.avail_out) {
if (pkg->pkg_zs.avail_in == 0) {
c = read(pkg->pkg_fd, pkg->pkg_buf, PKG_BUFSIZE);
if (c <= 0) {
errno = EIO;
return (-1);
}
pkg->pkg_zs.avail_in = c;
pkg->pkg_zs.next_in = pkg->pkg_buf;
}
c = inflate(&pkg->pkg_zs, Z_SYNC_FLUSH);
if (c != Z_OK && c != Z_STREAM_END) {
errno = EIO;
return (-1);
}
}
pkg->pkg_ofs += bufsz;
return (0);
}
/**
* @brief
* cache data of a tarfile
*
* @param[in] tf
* tarfile pointer
*
* @param[in] force
* If file size > PKG_MAXCACHESZ, cache that much
*
* @return 0, -1 (errno set to error value)
*/
static int
cache_data(struct tarfile *tf, int force)
{
struct package *pkg;
size_t sz;
if (tf == NULL) {
DBG(("%s: no file to cache data for?\n", __func__));
errno = EINVAL;
return (-1);
}
pkg = tf->tf_pkg;
if (pkg == NULL) {
DBG(("%s: no package associated with file?\n", __func__));
errno = EINVAL;
return (-1);
}
if (tf->tf_cachesz > 0) {
DBG(("%s: data already cached\n", __func__));
errno = EINVAL;
return (-1);
}
if (tf->tf_ofs != pkg->pkg_ofs) {
DBG(("%s: caching after force read of file %s?\n",
__func__, tf->tf_hdr.ut_name));
errno = EINVAL;
return (-1);
}
/* We don't cache everything... */
if (tf->tf_size > PKG_MAXCACHESZ && !force) {
errno = ENOBUFS;
return (-1);
}
sz = tf->tf_size < PKG_MAXCACHESZ ? tf->tf_size : PKG_MAXCACHESZ;
/* All files are padded to a multiple of 512 bytes. */
sz = (sz + 0x1ff) & ~0x1ff;
tf->tf_cache = malloc(sz);
if (tf->tf_cache == NULL) {
DBG(("%s: could not allocate %d bytes\n", __func__, (int)sz));
errno = ENOMEM;
return (-1);
}
tf->tf_cachesz = sz;
return (get_zipped(pkg, tf->tf_cache, sz));
}
/*
* Note that this implementation does not (and should not!) obey
* locale settings; you cannot simply substitute strtol here, since
* it does obey locale.
*/
static off_t
pkg_atol8(const char *p, unsigned char_cnt)
{
int64_t l, limit, last_digit_limit;
int digit, sign, base;
base = 8;
limit = INT64_MAX / base;
last_digit_limit = INT64_MAX % base;
while (*p == ' ' || *p == '\t')
p++;
if (*p == '-') {
sign = -1;
p++;
} else
sign = 1;
l = 0;
digit = *p - '0';
while (digit >= 0 && digit < base && char_cnt-- > 0) {
if (l>limit || (l == limit && digit > last_digit_limit)) {
l = UINT64_MAX; /* Truncate on overflow. */
break;
}
l = (l * base) + digit;
digit = *++p - '0';
}
return (sign < 0) ? -l : l;
}
/*
* Parse a base-256 integer. This is just a straight signed binary
* value in big-endian order, except that the high-order bit is
* ignored. Remember that "int64_t" may or may not be exactly 64
* bits; the implementation here tries to avoid making any assumptions
* about the actual size of an int64_t. It does assume we're using
* twos-complement arithmetic, though.
*/
static int64_t
pkg_atol256(const char *_p, unsigned char_cnt)
{
int64_t l, upper_limit, lower_limit;
const unsigned char *p = (const unsigned char *)_p;
upper_limit = INT64_MAX / 256;
lower_limit = INT64_MIN / 256;
/* Pad with 1 or 0 bits, depending on sign. */
if ((0x40 & *p) == 0x40)
l = (int64_t)-1;
else
l = 0;
l = (l << 6) | (0x3f & *p++);
while (--char_cnt > 0) {
if (l > upper_limit) {
l = INT64_MAX; /* Truncate on overflow */
break;
} else if (l < lower_limit) {
l = INT64_MIN;
break;
}
l = (l << 8) | (0xff & (int64_t)*p++);
}
return (l);
}
static off_t
pkg_atol(const char *p, unsigned char_cnt)
{
/*
* Technically, GNU pkg considers a field to be in base-256
* only if the first byte is 0xff or 0x80.
*/
if (*p & 0x80)
return (pkg_atol256(p, char_cnt));
return (pkg_atol8(p, char_cnt));
}
static int
get_mode(struct tarfile *tf)
{
return (pkg_atol(tf->tf_hdr.ut_mode, sizeof(tf->tf_hdr.ut_mode)));
}
/* GZip flag byte */
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
#define COMMENT 0x10 /* bit 4 set: file comment present */
#define RESERVED 0xE0 /* bits 5..7: reserved */
static int
new_package(int fd, struct package **pp)
{
struct package *pkg;
off_t ofs;
int flags, i, error;
pkg = malloc(sizeof(*pkg));
if (pkg == NULL)
return (ENOMEM);
bzero(pkg, sizeof(*pkg));
pkg->pkg_fd = fd;
/*
* Parse the header.
*/
error = EFTYPE;
ofs = 0;
/* Check megic. */
if (get_byte(pkg, &ofs) != 0x1f || get_byte(pkg, &ofs) != 0x8b)
goto fail;
/* Check method. */
if (get_byte(pkg, &ofs) != Z_DEFLATED)
goto fail;
/* Check flags. */
flags = get_byte(pkg, &ofs);
if (flags & RESERVED)
goto fail;
/* Skip time, xflags and OS code. */
for (i = 0; i < 6; i++) {
if (get_byte(pkg, &ofs) == -1)
goto fail;
}
/* Skip extra field. */
if (flags & EXTRA_FIELD) {
i = (get_byte(pkg, &ofs) & 0xff) |
((get_byte(pkg, &ofs) << 8) & 0xff);
while (i-- > 0) {
if (get_byte(pkg, &ofs) == -1)
goto fail;
}
}
/* Skip original file name. */
if (flags & ORIG_NAME) {
do {
i = get_byte(pkg, &ofs);
} while (i != 0 && i != -1);
if (i == -1)
goto fail;
}
/* Print the comment if it's there. */
if (flags & COMMENT) {
while (1) {
i = get_byte(pkg, &ofs);
if (i == -1)
goto fail;
if (i == 0)
break;
putchar(i);
}
}
/* Skip the CRC. */
if (flags & HEAD_CRC) {
if (get_byte(pkg, &ofs) == -1)
goto fail;
if (get_byte(pkg, &ofs) == -1)
goto fail;
}
/*
* Done parsing the ZIP header. Spkgt the inflation engine.
*/
error = inflateInit2(&pkg->pkg_zs, -15);
if (error != Z_OK)
goto fail;
*pp = pkg;
return (0);
fail:
free(pkg);
return (error);
}
static struct tarfile *
scan_tarfile(struct package *pkg, struct tarfile *last)
{
char buf[512];
struct tarfile *cur;
off_t ofs;
size_t sz;
cur = (last != NULL) ? last->tf_next : pkg->pkg_first;
if (cur == NULL) {
ofs = (last != NULL) ? last->tf_ofs + last->tf_size :
pkg->pkg_ofs;
ofs = (ofs + 0x1ff) & ~0x1ff;
/* Check if we've reached EOF. */
if (ofs < pkg->pkg_ofs) {
errno = ENOSPC;
return (NULL);
}
if (ofs != pkg->pkg_ofs) {
if (last != NULL && pkg->pkg_ofs == last->tf_ofs) {
if (cache_data(last, 0) == -1)
return (NULL);
} else {
sz = ofs - pkg->pkg_ofs;
while (sz != 0) {
if (sz > sizeof(buf))
sz = sizeof(buf);
if (get_zipped(pkg, buf, sz) == -1)
return (NULL);
sz = ofs - pkg->pkg_ofs;
}
}
}
cur = malloc(sizeof(*cur));
if (cur == NULL)
return (NULL);
memset(cur, 0, sizeof(*cur));
cur->tf_pkg = pkg;
while (1) {
if (get_zipped(pkg, &cur->tf_hdr,
sizeof(cur->tf_hdr)) == -1) {
free(cur);
return (NULL);
}
/*
* There are always 2 empty blocks appended to
* a PKG. It marks the end of the archive.
*/
if (strncmp(cur->tf_hdr.ut_magic, "ustar", 5) != 0) {
free(cur);
errno = ENOSPC;
return (NULL);
}
cur->tf_ofs = pkg->pkg_ofs;
cur->tf_size = pkg_atol(cur->tf_hdr.ut_size,
sizeof(cur->tf_hdr.ut_size));
if (cur->tf_hdr.ut_name[0] != '+')
break;
/*
* Skip package meta-files.
*/
ofs = cur->tf_ofs + cur->tf_size;
ofs = (ofs + 0x1ff) & ~0x1ff;
while (pkg->pkg_ofs < ofs) {
if (get_zipped(pkg, buf, sizeof(buf)) == -1) {
free(cur);
return (NULL);
}
}
}
if (last != NULL)
last->tf_next = cur;
else
pkg->pkg_first = cur;
pkg->pkg_last = cur;
}
return (cur);
}
