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mc/vfs/tar.c

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/* Virtual File System: GNU Tar file system.
Copyright (C) 1995 The Free Software Foundation
Written by: 1995 Jakub Jelinek
Rewritten by: 1998 Pavel Machek
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License
as published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Namespace: vfs_tarfs_ops, tar_gzipped_memlimit */
#include <config.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#include <errno.h>
#ifdef SCO_FLAVOR
#include <sys/timeb.h> /* alex: for struct timeb definition */
#endif /* SCO_FLAVOR */
#include <time.h>
#include "../src/fs.h"
#include "../src/util.h"
#include "../src/dialog.h" /* For MSG_ERROR */
#include "../src/mem.h"
#include "../src/mad.h"
#include "../src/main.h"
#include "vfs.h"
#include "tar.h"
#include "names.h"
/* The limit for a compressed tar file to be loaded in core */
int tar_gzipped_memlimit = 1*1024*1024;
/* used to rotate the dash */
static int dash_number = 0;
#define isodigit(c) ( ((c) >= '0') && ((c) <= '7') )
/*
* Quick and dirty octal conversion.
*
* Result is -1 if the field is invalid (all blank, or nonoctal).
*/
static long from_oct (int digs, char *where)
{
register long value;
while (isspace (*where)) { /* Skip spaces */
where++;
if (--digs <= 0)
return -1; /* All blank field */
}
value = 0;
while (digs > 0 && isodigit (*where)) { /* Scan till nonoctal */
value = (value << 3) | (*where++ - '0');
--digs;
}
if (digs > 0 && *where && !isspace (*where))
return -1; /* Ended on non-space/nul */
return value;
}
static struct archive *first_archive = NULL;
static int my_errno = 0;
static struct stat hstat; /* Stat struct corresponding */
static char *current_file_name, *current_link_name;
static struct entry *find_entry (struct entry *dir, char *name, int make_dirs, int make_file);
static void tarfs_fill_names (vfs *me, void (*func)(char *))
{
struct archive *a = first_archive;
char *name;
while (a){
name = copy_strings ( a->name, "#tar/",
a->current_dir->name, 0);
(*func)(name);
free (name);
a = a->next;
}
}
static void make_dot_doubledot (struct entry *ent)
{
struct entry *entry = (struct entry *)
xmalloc (sizeof (struct entry), "Tar: entry");
struct entry *parentry = ent->dir;
struct inode *inode = ent->inode, *parent;
parent = (parentry != NULL) ? parentry->inode : NULL;
entry->name = strdup (".");
entry->has_changed = 0;
entry->header_offset = -1;
entry->header_size = 0;
entry->extended_offset = -1;
entry->extended_size = 0;
entry->inode = inode;
entry->dir = ent;
inode->first_in_subdir = entry;
inode->last_in_subdir = entry;
inode->nlink++;
entry->next_in_dir = (struct entry *)
xmalloc (sizeof (struct entry), "Tar: entry");
entry=entry->next_in_dir;
entry->name = strdup ("..");
entry->has_changed = 0;
entry->header_offset = -1;
entry->header_size = 0;
entry->extended_offset = -1;
entry->extended_size = 0;
inode->last_in_subdir = entry;
entry->next_in_dir = NULL;
if (parent != NULL) {
entry->inode = parent;
entry->dir = parentry;
parent->nlink++;
} else {
entry->inode = inode;
entry->dir = ent;
inode->nlink++;
}
}
static struct entry *generate_entry (struct archive *archive,
char *name, struct entry *parentry, mode_t mode)
{
mode_t myumask;
struct inode *inode, *parent;
struct entry *entry;
parent = (parentry != NULL) ? parentry->inode : NULL;
entry = (struct entry *)
xmalloc (sizeof (struct entry), "Tar: entry");
entry->name = strdup (name);
entry->has_changed = 0;
entry->header_offset = -1;
entry->header_size = 0;
entry->extended_offset = -1;
entry->extended_size = 0;
entry->next_in_dir = NULL;
entry->dir = parentry;
if (parent != NULL) {
parent->last_in_subdir->next_in_dir = entry;
parent->last_in_subdir = entry;
}
inode = (struct inode *)
xmalloc (sizeof (struct inode), "Tar: inode");
entry->inode = inode;
inode->local_filename = NULL;
inode->has_changed = 0;
inode->is_open = 0;
inode->linkname = 0;
inode->inode = (archive->__inode_counter)++;
inode->dev = archive->rdev;
inode->archive = archive;
inode->data_offset = -1;
myumask = umask (022);
umask (myumask);
inode->mode = mode & ~myumask;
mode = inode->mode;
inode->rdev = 0;
inode->uid = getuid ();
inode->gid = getgid ();
inode->std = 1;
inode->size = 0;
inode->mtime = time (NULL);
inode->atime = inode->mtime;
inode->ctime = inode->mtime;
inode->nlink = 1;
if (S_ISDIR (mode)) {
inode->linkflag = LF_DIR;
make_dot_doubledot (entry);
} else if (S_ISLNK (mode)) {
inode->linkflag = LF_SYMLINK;
} else if (S_ISCHR (mode)) {
inode->linkflag = LF_CHR;
} else if (S_ISBLK (mode)) {
inode->linkflag = LF_BLK;
} else if (S_ISFIFO (mode) || S_ISSOCK (mode)) {
inode->linkflag = LF_FIFO;
} else {
inode->linkflag = LF_NORMAL;
}
return entry;
}
static void free_entries (struct entry *entry)
{
return;
}
static void free_archive (struct archive *archive)
{
long l;
if (archive->is_gzipped == targz_growing) {
free (archive->block_first);
if (archive->block_ptr != NULL) {
for (l = 0; l < archive->count_blocks; l++)
free (archive->block_ptr [l]);
free (archive->block_ptr);
}
} else {
if (archive->tmpname)
free (archive->tmpname);
if (archive->fd != -1)
mc_close(archive->fd);
}
free_entries (archive->root_entry);
free (archive->name);
free (archive);
}
static INLINE int gzip_limit_ok (int size)
{
return (size <= tar_gzipped_memlimit || tar_gzipped_memlimit < 0);
}
/* So we have to decompress it...
* It is not that easy, because we would like to handle all the files
* from all the vfs's. So, we do this like this:
* we run a pipe:
* for (;;) mc_read | gzip -cdf | store into growing buffer
*
* Returns: 0 on failure
*/
static INLINE int load_compressed_tar (struct archive *current_archive,
int size, int fd, int type)
{
int pipehandle, i;
long l, l2;
union record *ur;
pid_t p;
char *cmd, *cmd_flags;
void *tmp;
l2 = 0;
current_archive->is_gzipped = targz_growing;
size = (size + RECORDSIZE - 1) / RECORDSIZE * RECORDSIZE;
current_archive->count_first = size / RECORDSIZE;
current_archive->count_blocks = 0;
current_archive->block_ptr = NULL;
current_archive->root_entry = NULL;
decompress_command_and_arg (type, &cmd, &cmd_flags);
pipehandle = mc_doublepopen (fd, -1, &p, cmd, cmd, cmd_flags, NULL);
if (pipehandle == -1)
{
free (current_archive);
mc_close (fd);
return 0;
}
/* On some systems it's better to allocate the memory for the tar-file
this way:
- allocate some memory we don't need (size 100k).
- allocate the memory for the uncompressed tar-file (the size of
this memory block can be really big - five times the size of the
compressed tar-file).
- free the 100k from the first step
Without the extra steps a few malloc/free implementations can't give
back memory to the operating system when the memory for the tar-file is
freed after the vfs-timeout.
*/
tmp = malloc (100*1024);
current_archive->block_first = (union record *) malloc (size);
if (tmp)
free (tmp); /* make a hole in size of 100k */
if (0 == current_archive->block_first) {
mc_doublepclose (pipehandle, p);
free (current_archive);
mc_close (fd);
return 0;
}
ur = current_archive->block_first;
l = 0;
while ((i = read (pipehandle, (char *) ur, RECORDSIZE)) == RECORDSIZE) {
l++;
if (l >= current_archive->count_first) {
l2 = l - current_archive->count_first;
if (l2 % TAR_GROWING_CHUNK_SIZE)
ur++;
else {
union record **tmp = (union record **)
xmalloc ((++current_archive->count_blocks) *
sizeof (union record **), "Tar: Growing buffers");
if (current_archive->block_ptr != NULL) {
bcopy (current_archive->block_ptr, tmp,
(current_archive->count_blocks - 1) *
sizeof (union record **));
free (current_archive->block_ptr);
}
current_archive->block_ptr = tmp;
ur = (union record *)
xmalloc (TAR_GROWING_CHUNK_SIZE * RECORDSIZE,
"Tar: Growing buffers");
current_archive->block_ptr [current_archive->count_blocks - 1] = ur;
}
} else
ur++;
if ((dash_number++ % 64) == 0)
rotate_dash ();
}
i = mc_doublepclose (pipehandle, p);
mc_close (fd);
if (i == -1) {
free_archive (current_archive);
return 0;
}
current_archive->current_record = current_archive->block_first;
return 1;
}
/* Returns a file handle of the opened local tar file or -1 on error */
static INLINE int uncompress_tar_file (struct archive *current_archive,
int size, int fd, int type)
{
int result;
/* From time we have sfs this function is pretty trivial */
current_archive->is_gzipped = tar_uncompressed_local;
current_archive->tmpname = copy_strings( current_archive->name,
decompress_extension (type), NULL );
result = mc_open (current_archive->tmpname, O_RDONLY);
if (result == -1)
free_archive (current_archive);
return result;
}
/* Returns fd of the open tar file */
static int open_tar_archive (char *name, struct archive **pparc)
{
static dev_t __tar_no = 0;
int result, type;
long size;
mode_t mode;
struct archive *current_archive;
static struct entry *root_entry;
result = mc_open (name, O_RDONLY);
if (result == -1) {
message_2s (1, MSG_ERROR, _("Couldn't open tar archive\n%s"), name);
return -1;
}
current_archive = (struct archive *)
xmalloc (sizeof (struct archive), "Tar archive");
current_archive->current_tar_position = 0;
current_archive->name = strdup (name);
current_archive->__inode_counter = 0;
mc_stat (name, &(current_archive->tarstat));
current_archive->rdev = __tar_no++;
current_archive->next = first_archive;
current_archive->fd_usage = 0;
current_archive->fd = -1;
current_archive->tmpname = NULL;
size = is_gunzipable (result, &type);
mc_lseek (result, 0, SEEK_SET);
/* Find out the method to handle this tar file */
if (size > 0 && gzip_limit_ok (size)) {
if (load_compressed_tar (current_archive, size, result, type) == 0) {
message_2s (1, MSG_ERROR, _("Couldn't load compressed tar\n%s"), name);
return -1;
}
result = 0;
} else if (size > 0) {
result = uncompress_tar_file (current_archive, size, result, type);
if (result == -1) {
message_2s (1, MSG_ERROR, _("Couldn't uncompress tar archive\n%s"), name);
return -1;
}
} else {
current_archive->is_gzipped = tar_normal;
}
current_archive->fd = result;
first_archive = current_archive;
mode = current_archive->tarstat.st_mode & 07777;
if (mode & 0400)
mode |= 0100;
if (mode & 0040)
mode |= 0010;
if (mode & 0004)
mode |= 0001;
mode |= S_IFDIR;
root_entry = generate_entry (current_archive, "/", NULL, mode);
root_entry->inode->uid = current_archive->tarstat.st_uid;
root_entry->inode->gid = current_archive->tarstat.st_gid;
root_entry->inode->atime = current_archive->tarstat.st_atime;
root_entry->inode->ctime = current_archive->tarstat.st_ctime;
root_entry->inode->mtime = current_archive->tarstat.st_mtime;
current_archive->root_entry = root_entry;
current_archive->current_dir = root_entry;
*pparc = current_archive;
return result;
}
static int get_current_position (struct archive *archive, int tard)
{
return archive->current_tar_position;
}
static union record *find_current_record (struct archive *archive, long pos)
{
long l, l2;
static union record *ur;
l = pos / RECORDSIZE;
if (l >= archive->count_first) {
l2 = l - archive->count_first;
ur = archive->block_ptr [l2 / TAR_GROWING_CHUNK_SIZE]
+ (l2 % TAR_GROWING_CHUNK_SIZE);
} else
ur = archive->block_first + l;
return ur;
}
static union record rec_buf;
static union record *get_next_record (struct archive *archive, int tard)
{
if (archive->is_gzipped == targz_growing) {
bcopy (archive->current_record, rec_buf.charptr, RECORDSIZE);
archive->current_record = find_current_record (archive, archive->current_tar_position + RECORDSIZE);
} else if (mc_read (tard, rec_buf.charptr, RECORDSIZE) != RECORDSIZE)
return NULL; /* An error has occurred */
archive->current_tar_position += RECORDSIZE;
return &rec_buf;
}
static void skip_n_records (struct archive *archive, int tard, int n)
{
if (archive->is_gzipped == targz_growing)
archive->current_record = find_current_record (archive, archive->current_tar_position + n * RECORDSIZE);
else
mc_lseek (tard, n * RECORDSIZE, SEEK_CUR);
archive->current_tar_position += n * RECORDSIZE;
}
/*
* Return 1 for success, 0 if the checksum is bad, EOF on eof,
* 2 for a record full of zeros (EOF marker).
*
*/
static int read_header (struct archive *archive, int tard)
{
register int i;
register long sum, signed_sum, recsum;
register char *p;
register union record *header;
char **longp;
char *bp, *data;
int size, written;
static char *next_long_name = NULL, *next_long_link = NULL;
long header_position = get_current_position (archive, tard);
recurse:
header = get_next_record (archive, tard);
if (NULL == header)
return EOF;
recsum = from_oct (8, header->header.chksum);
sum = 0; signed_sum = 0;
p = header->charptr;
for (i = sizeof (*header); --i >= 0;) {
/*
* We can't use unsigned char here because of old compilers,
* e.g. V7.
*/
signed_sum += *p;
sum += 0xFF & *p++;
}
/* Adjust checksum to count the "chksum" field as blanks. */
for (i = sizeof (header->header.chksum); --i >= 0;) {
sum -= 0xFF & header->header.chksum[i];
signed_sum -= (char) header->header.chksum[i];
}
sum += ' ' * sizeof header->header.chksum;
signed_sum += ' ' * sizeof header->header.chksum;
if (sum == 8 * ' ') {
/*
* This is a zeroed record...whole record is 0's except
* for the 8 blanks we faked for the checksum field.
*/
return 2;
}
if (sum != recsum && signed_sum != recsum)
return 0;
/*
* linkflag on BSDI tar (pax) always '\000'
*/
if(header->header.linkflag == '\000' &&
strlen(header->header.arch_name) &&
header->header.arch_name[strlen(header->header.arch_name) - 1] == '/')
header->header.linkflag = LF_DIR;
/*
* Good record. Decode file size and return.
*/
if (header->header.linkflag == LF_LINK || header->header.linkflag == LF_DIR)
hstat.st_size = 0; /* Links 0 size on tape */
else
hstat.st_size = from_oct (1 + 12, header->header.size);
header->header.arch_name[NAMSIZ - 1] = '\0';
if (header->header.linkflag == LF_LONGNAME
|| header->header.linkflag == LF_LONGLINK) {
longp = ((header->header.linkflag == LF_LONGNAME)
? &next_long_name
: &next_long_link);
if (*longp)
free (*longp);
bp = *longp = (char *) xmalloc (hstat.st_size, "Tar: Long name");
for (size = hstat.st_size;
size > 0;
size -= written) {
data = get_next_record (archive, tard)->charptr;
if (data == NULL) {
message_1s (1, MSG_ERROR, _("Unexpected EOF on archive file"));
return 0;
}
written = RECORDSIZE;
if (written > size)
written = size;
bcopy (data, bp, written);
bp += written;
}
#if 0
if (hstat.st_size > 1)
bp [hstat.st_size - 1] = 0; /* just to make sure */
#endif
goto recurse;
} else {
struct entry *entry, *pent;
struct inode *inode;
long data_position;
char *p, *q;
int len;
int isdir = 0;
current_file_name = (next_long_name
? next_long_name
: strdup (header->header.arch_name));
len = strlen (current_file_name);
if (current_file_name[len - 1] == '/') {
current_file_name[len - 1] = 0;
isdir = 1;
}
current_link_name = (next_long_link
? next_long_link
: strdup (header->header.arch_linkname));
len = strlen (current_link_name);
if (len && current_link_name [len - 1] == '/')
current_link_name[len - 1] = 0;
next_long_link = next_long_name = NULL;
data_position = get_current_position (archive, tard);
p = strrchr (current_file_name, '/');
if (p == NULL) {
p = current_file_name;
q = current_file_name + strlen (current_file_name); /* "" */
} else {
*(p++) = 0;
q = current_file_name;
}
pent = find_entry (archive->root_entry, q, 1, 0);
if (pent == NULL) {
message_1s (1, MSG_ERROR, _("Inconsistent tar archive"));
}
entry = (struct entry *) xmalloc (sizeof (struct entry), "Tar: entry");
entry->name = strdup (p);
entry->has_changed = 0;
entry->header_offset = header_position;
entry->header_size = data_position - header_position;
entry->extended_offset = -1;
entry->extended_size = 0;
entry->next_in_dir = NULL;
entry->dir = pent;
if (pent != NULL) {
pent->inode->last_in_subdir->next_in_dir = entry;
pent->inode->last_in_subdir = entry;
}
free (current_file_name);
if (header->header.linkflag == LF_LINK) {
pent = find_entry (archive->root_entry, current_link_name, 0, 0);
if (pent == NULL) {
message_1s (1, MSG_ERROR, _("Inconsistent tar archive"));
} else {
entry->inode = pent->inode;
pent->inode->nlink++;
free (current_link_name);
if (header->header.isextended) {
entry->extended_offset = data_position;
while (get_next_record (archive, tard)->ext_hdr.isextended);
data_position = get_current_position (archive, tard);
entry->extended_size = data_position - entry->extended_offset;
}
return 1;
}
}
inode = (struct inode *) xmalloc (sizeof (struct inode), "Tar: inode");
entry->inode = inode;
inode->local_filename = NULL;
inode->has_changed = 0;
inode->is_open = 0;
inode->inode = (archive->__inode_counter)++;
inode->nlink = 1;
inode->dev = archive->rdev;
inode->archive = archive;
inode->data_offset = data_position;
inode->mode = from_oct (8, header->header.mode);
/* Adjust inode->mode because there are tar-files with
* linkflag==LF_SYMLINK and S_ISLNK(mod)==0. I don't
* know about the other modes but I think I cause no new
* problem when I adjust them, too. -- Norbert.
*/
if (header->header.linkflag == LF_DIR) {
inode->mode |= S_IFDIR;
} else if (header->header.linkflag == LF_SYMLINK) {
inode->mode |= S_IFLNK;
} else if (header->header.linkflag == LF_CHR) {
inode->mode |= S_IFCHR;
} else if (header->header.linkflag == LF_BLK) {
inode->mode |= S_IFBLK;
} else if (header->header.linkflag == LF_FIFO) {
inode->mode |= S_IFIFO;
} else
inode->mode |= S_IFREG;
inode->rdev = 0;
if (!strcmp (header->header.magic, TMAGIC)) {
inode->uid = *header->header.uname ? finduid (header->header.uname) :
from_oct (8, header->header.uid);
inode->gid = *header->header.gname ? findgid (header->header.gname) :
from_oct (8, header->header.gid);
switch (header->header.linkflag) {
case LF_BLK:
case LF_CHR:
inode->rdev = (from_oct (8, header->header.devmajor) << 8) |
from_oct (8, header->header.devminor);
}
inode->std = 1;
} else { /* Old Unix tar */
inode->uid = from_oct (8, header->header.uid);
inode->gid = from_oct (8, header->header.gid);
inode->std = 0;
}
inode->size = hstat.st_size;
inode->mtime = from_oct (1 + 12, header->header.mtime);
inode->atime = from_oct (1 + 12, header->header.atime);
inode->ctime = from_oct (1 + 12, header->header.ctime);
inode->linkflag = header->header.linkflag;
if (*current_link_name) {
inode->linkname = current_link_name;
} else {
free (current_link_name);
inode->linkname = NULL;
}
if (inode->linkflag == LF_DIR || isdir) {
inode->mode |= S_IFDIR;
make_dot_doubledot (entry);
}
if (header->header.isextended) {
entry->extended_offset = data_position;
while (get_next_record (archive, tard)->ext_hdr.isextended);
inode->data_offset = get_current_position (archive, tard);
entry->extended_size = inode->data_offset - entry->extended_offset;
}
return 1;
}
}
/*
* Main loop for reading an archive.
* Returns 0 on success, -1 on error.
*/
static int read_tar_archive (char *name, struct archive **pparc)
{
int status = 3; /* Initial status at start of archive */
int prev_status;
int tard;
struct archive *archive;
if ((tard = open_tar_archive (name, &archive)) == -1) { /* Open for reading */
message_2s (1, MSG_ERROR, _("Couldn't open tar archive\n%s"), name);
return -1;
}
for (;;) {
prev_status = status;
status = read_header (archive, tard);
switch (status) {
case 1: /* Valid header */
skip_n_records (archive, tard, (hstat.st_size + RECORDSIZE - 1) / RECORDSIZE);
continue;
/*
* If the previous header was good, tell them
* that we are skipping bad ones.
*/
case 0: /* Invalid header */
switch (prev_status) {
case 3: /* Error on first record */
message_2s (1, MSG_ERROR, _("Hmm,...\n%s\ndoesn't look like a tar archive."), name);
/* FALL THRU */
case 2: /* Error after record of zeroes */
case 1: /* Error after header rec */
#if 0
message_1s (0, " Warning ", "Skipping to next file header...");
#endif
case 0: /* Error after error */
return -1;
}
case 2: /* Record of zeroes */
status = prev_status; /* If error after 0's */
/* FALL THRU */
case EOF: /* End of archive */
break;
}
break;
};
*pparc = archive;
return 0;
}
static char *get_path (char *inname, struct archive **archive, int is_dir,
int do_not_open);
/* Returns path inside argument. Returned char* is inside inname, which is mangled
* by this operation (so you must not free it's return value)
*/
static char *get_path_mangle (char *inname, struct archive **archive, int is_dir,
int do_not_open)
{
char *local, *archive_name;
int result = -1;
struct archive *parc;
struct vfs_stamping *parent;
vfs *v;
struct stat stat_buf;
archive_name = inname;
vfs_split( inname, &local, NULL );
if (!local)
local = "";
mc_stat (archive_name, &stat_buf);
for (parc = first_archive; parc != NULL; parc = parc->next)
if (!strcmp (parc->name, archive_name)) {
if (vfs_uid && (!(stat_buf.st_mode & 0004)))
if ((stat_buf.st_gid != vfs_gid) || !(stat_buf.st_mode & 0040))
if ((stat_buf.st_uid != vfs_uid) || !(stat_buf.st_mode & 0400))
return NULL;
/* Has the cached archive been changed on the disk? */
if (parc->tarstat.st_mtime < stat_buf.st_mtime) { /* Yes, reload! */
(*vfs_tarfs_ops.free) ((vfsid) parc);
vfs_rmstamp (&vfs_tarfs_ops, (vfsid) parc, 0);
break;
}
/* Hasn't been modified, give it a new timeout */
vfs_stamp (&vfs_tarfs_ops, (vfsid) parc);
goto return_success;
}
if (do_not_open)
result = -1;
else
result = read_tar_archive (archive_name, &parc);
if (result == -1) ERRNOR (EIO, NULL);
v = vfs_type (archive_name);
if (v == &vfs_local_ops) {
parent = NULL;
} else {
parent = xmalloc (sizeof (struct vfs_stamping), "vfs stamping");
parent->v = v;
parent->next = 0;
parent->id = (*v->getid) (v, archive_name, &(parent->parent));
}
vfs_add_noncurrent_stamps (&vfs_tarfs_ops, (vfsid) parc, parent);
vfs_rm_parents (parent);
return_success:
*archive = parc;
return local;
}
struct loop_protect {
struct entry *entry;
struct loop_protect *next;
};
static int errloop;
static int notadir;
static struct entry *
__find_entry (struct entry *dir, char *name,
struct loop_protect *list, int make_dirs, int make_file);
static struct entry *
__resolve_symlinks (struct entry *entry,
struct loop_protect *list)
{
struct entry *pent;
struct loop_protect *looping;
if (!S_ISLNK (entry->inode->mode))
return entry;
for (looping = list; looping != NULL; looping = looping->next)
if (entry == looping->entry) { /* Here we protect us against symlink looping */
errloop = 1;
return NULL;
}
looping = (struct loop_protect *)
xmalloc (sizeof (struct loop_protect),
"Tar: symlink looping protection");
looping->entry = entry;
looping->next = list;
pent = __find_entry (entry->dir, entry->inode->linkname, looping, 0, 0);
free (looping);
if (pent == NULL)
my_errno = ENOENT;
return pent;
}
static struct entry *my_resolve_symlinks (struct entry *entry)
{
struct entry *res;
errloop = 0;
notadir = 0;
res = __resolve_symlinks (entry, NULL);
if (res == NULL) {
if (errloop)
my_errno = ELOOP;
else if (notadir)
my_errno = ENOTDIR;
}
return res;
}
struct pseudofile {
struct archive *archive;
long pos;
long begin;
long end;
struct entry *entry;
};
static struct entry *find_entry (struct entry *dir, char *name, int make_dirs, int make_file);
static void *tar_open (vfs *me, char *file, int flags, int mode)
{
struct pseudofile *tar_info;
struct archive *archive;
char *q;
struct entry *entry;
if ((q = get_path_mangle (file, &archive, 0, 0)) == NULL)
return NULL;
entry = find_entry (archive->root_entry, q, 0, 0);
if (entry == NULL)
return NULL;
if ((entry = my_resolve_symlinks (entry)) == NULL)
return NULL;
if (S_ISDIR (entry->inode->mode)) ERRNOR (EISDIR, NULL);
if ((flags & O_ACCMODE) != O_RDONLY) ERRNOR (EROFS, NULL);
tar_info = (struct pseudofile *) xmalloc (sizeof (struct pseudofile), "Tar: tar_open");
tar_info->archive = archive;
tar_info->pos = 0;
tar_info->begin = entry->inode->data_offset;
tar_info->end = tar_info->begin + entry->inode->size;
tar_info->entry = entry;
entry->inode->is_open++;
/* i.e. we had no open files and now we have one */
vfs_rmstamp (&vfs_tarfs_ops, (vfsid) archive, 1);
archive->fd_usage++;
return tar_info;
}
static int tar_read (void *data, char *buffer, int count)
{
struct pseudofile *file = (struct pseudofile *)data;
if (file->archive->is_gzipped != targz_growing &&
mc_lseek (file->archive->fd, file->begin + file->pos, SEEK_SET) !=
file->begin + file->pos) ERRNOR (EIO, -1);
if (count > file->end - file->begin - file->pos)
count = file->end - file->begin - file->pos;
if (file->archive->is_gzipped == targz_growing) {
char *p = buffer;
int cnt = count;
int i = file->begin + file->pos, j;
if (i % RECORDSIZE) {
j = RECORDSIZE - (i % RECORDSIZE);
if (cnt < j)
j = cnt;
bcopy (((char *) find_current_record (file->archive, i / RECORDSIZE * RECORDSIZE)) + (i % RECORDSIZE),
p, j);
cnt -= j;
p += j;
i += j;
}
while (cnt) {
if (cnt > RECORDSIZE)
j = RECORDSIZE;
else
j = cnt;
bcopy ((char *) find_current_record (file->archive, i),
p, j);
i += j;
p += j;
cnt -= j;
}
}
else if ((count = mc_read (file->archive->fd, buffer, count)) == -1) ERRNOR (errno, -1);
file->pos += count;
return count;
}
static int tar_close (void *data)
{
struct pseudofile *file;
file = (struct pseudofile *)data;
file->archive->fd_usage--;
if (!file->archive->fd_usage) {
struct vfs_stamping *parent;
vfs *v;
v = vfs_type (file->archive->name);
if (v == &vfs_local_ops) {
parent = NULL;
} else {
parent = xmalloc (sizeof (struct vfs_stamping), "vfs stamping");
parent->v = v;
parent->next = 0;
parent->id = (*v->getid) (v, file->archive->name, &(parent->parent));
}
vfs_add_noncurrent_stamps (&vfs_tarfs_ops, (vfsid) (file->archive), parent);
vfs_rm_parents (parent);
}
(file->entry->inode->is_open)--;
free (data);
return 0;
}
#include "shared_tar_ext.c"
static int tar_chmod (vfs *me, char *path, int mode)
{ /* Fixme: are you sure? IMO this is guaranteed to fail */
return chmod (path, mode);
}
static int tar_chown (vfs *me, char *path, int owner, int group)
{ /* Fixme: are you sure? IMO this is guaranteed to fail */
return chown (path, owner, group);
}
static int tar_chdir (vfs *me, char *path)
{
struct archive *archive;
char *q;
struct entry *entry;
my_errno = ENOTDIR;
if ((q = get_path_mangle (path, &archive, 1, 0)) == NULL)
return -1;
entry = find_entry (archive->root_entry, q, 0, 0);
if (!entry)
return -1;
entry = my_resolve_symlinks (entry);
if ((!entry) || (!S_ISDIR (entry->inode->mode)))
return -1;
entry->inode->archive->current_dir = entry;
my_errno = 0;
return 0;
}
static int tar_lseek (void *data, off_t offset, int whence)
{
struct pseudofile *file = (struct pseudofile *) data;
switch (whence) {
case SEEK_CUR:
offset += file->pos; break;
case SEEK_END:
offset += file->end - file->begin; break;
}
if (offset < 0)
file->pos = 0;
else if (offset < file->end - file->begin)
file->pos = offset;
else
file->pos = file->end;
return file->pos;
}
static vfsid tar_getid (vfs *me, char *path, struct vfs_stamping **parent)
{
struct archive *archive;
vfs *v;
char *p;
vfsid id;
struct vfs_stamping *par;
*parent = NULL;
if (!(p = get_path (path, &archive, 0, 1)))
return (vfsid) -1;
free(p);
v = vfs_type (archive->name);
id = (*v->getid) (v, archive->name, &par);
if (id != (vfsid)-1) {
*parent = xmalloc (sizeof (struct vfs_stamping), "vfs stamping");
(*parent)->v = v;
(*parent)->id = id;
(*parent)->parent = par;
(*parent)->next = NULL;
}
return (vfsid) archive;
}
static int tar_nothingisopen (vfsid id)
{
if (((struct archive *)id)->fd_usage <= 0)
return 1;
else
return 0;
}
static void free_entry (struct entry *e)
{
int i = --(e->inode->nlink);
if (S_ISDIR (e->inode->mode) && e->inode->first_in_subdir != NULL) {
struct entry *f = e->inode->first_in_subdir;
e->inode->first_in_subdir = NULL;
free_entry (f);
}
if (i <= 0) {
if (e->inode->linkname != NULL)
free (e->inode->linkname);
if (e->inode->local_filename != NULL) {
unlink (e->inode->local_filename);
free (e->inode->local_filename);
}
free (e->inode);
}
if (e->next_in_dir != NULL)
free_entry (e->next_in_dir);
free (e->name);
free (e);
}
static void tar_free (vfsid id)
{
struct archive *parc;
struct archive *archive = (struct archive *)id;
free_entry (archive->root_entry);
if (archive == first_archive) {
first_archive = archive->next;
} else {
for (parc = first_archive; parc != NULL; parc = parc->next)
if (parc->next == archive)
break;
if (parc != NULL)
parc->next = archive->next;
}
free_archive (archive);
}
static char *tar_getlocalcopy (vfs *me, char *path)
{
struct archive *archive;
char *p, *q;
struct entry *entry;
char buf[MC_MAXPATHLEN];
strcpy( buf, path );
if ((q = get_path_mangle (path, &archive, 1, 0)) == NULL)
return NULL;
entry = find_entry (archive->root_entry, q, 0, 0);
if (entry == NULL)
return NULL;
if ((entry = my_resolve_symlinks (entry)) == NULL)
return NULL;
if (entry->inode->local_filename != NULL)
return entry->inode->local_filename;
p = mc_def_getlocalcopy (me, buf);
if (p != NULL) {
entry->inode->local_filename = p;
}
return p;
}
static void tar_ungetlocalcopy (vfs *me, char *path, char *local, int has_changed)
{
/* We do just nothing. (We are read only and do not need to free local,
since it will be freed when tar archive will be freed */
}
vfs vfs_tarfs_ops =
{
NULL, /* This is place of next pointer */
"TApe aRchiver decompressor",
0, /* flags */
"utar", /* prefix */
NULL, /* data */
0, /* errno */
NULL,
NULL,
tarfs_fill_names,
NULL,
tar_open,
tar_close,
tar_read,
NULL,
s_opendir,
s_readdir,
s_closedir,
s_telldir,
s_seekdir,
s_stat,
s_lstat,
s_fstat,
tar_chmod,
tar_chown,
NULL,
s_readlink,
NULL,
NULL,
NULL,
NULL,
tar_chdir,
s_errno,
tar_lseek,
NULL,
tar_getid,
tar_nothingisopen,
tar_free,
tar_getlocalcopy,
tar_ungetlocalcopy,
NULL, /* mkdir */
NULL,
NULL,
NULL
MMAPNULL
};
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