mirror of https://github.com/MidnightCommander/mc
576 lines
14 KiB
C
576 lines
14 KiB
C
/* Virtual File System: GNU Tar file system.
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Copyright (C) 1995 The Free Software Foundation
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Written by: 1995 Jakub Jelinek
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Rewritten by: 1998 Pavel Machek
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License
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as published by the Free Software Foundation; either version 2 of
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the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* Namespace: vfs_tarfs_ops */
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#include <config.h>
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#include <errno.h>
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#include "utilvfs.h"
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#include "xdirentry.h"
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#include "../src/dialog.h" /* For MSG_ERROR */
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#include "tar.h"
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#include "names.h"
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#define isodigit(c) ( ((c) >= '0') && ((c) <= '7') )
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/*
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* Quick and dirty octal conversion.
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*
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* Result is -1 if the field is invalid (all blank, or nonoctal).
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*/
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static long from_oct (int digs, char *where)
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{
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register long value;
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while (isspace ((unsigned char) *where)) { /* Skip spaces */
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where++;
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if (--digs <= 0)
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return -1; /* All blank field */
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}
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value = 0;
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while (digs > 0 && isodigit (*where)) { /* Scan till nonoctal */
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value = (value << 3) | (*where++ - '0');
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--digs;
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}
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if (digs > 0 && *where && !isspace ((unsigned char) *where))
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return -1; /* Ended on non-space/nul */
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return value;
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}
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static struct stat hstat; /* Stat struct corresponding */
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static void tar_free_archive (vfs *me, vfs_s_super *archive)
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{
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if (archive->u.tar.fd != -1)
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mc_close(archive->u.tar.fd);
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}
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/* As we open one archive at a time, it is safe to have this static */
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static int current_tar_position = 0;
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/* Returns fd of the open tar file */
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static int tar_open_archive (vfs *me, char *name, vfs_s_super *archive)
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{
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int result, type;
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mode_t mode;
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struct vfs_s_inode *root;
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result = mc_open (name, O_RDONLY);
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if (result == -1) {
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message_2s (1, MSG_ERROR, _("Couldn't open tar archive\n%s"), name);
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ERRNOR (ENOENT, -1);
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}
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archive->name = g_strdup (name);
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mc_stat (name, &(archive->u.tar.tarstat));
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archive->u.tar.fd = -1;
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/* Find out the method to handle this tar file */
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type = get_compression_type (result);
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mc_lseek (result, 0, SEEK_SET);
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if (type != COMPRESSION_NONE) {
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char *s;
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mc_close( result );
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s = g_strconcat ( archive->name, decompress_extension (type), NULL );
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result = mc_open (s, O_RDONLY);
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if (result == -1)
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message_2s (1, MSG_ERROR, _("Couldn't open tar archive\n%s"), s);
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g_free(s);
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if (result == -1)
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ERRNOR (ENOENT, -1);
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}
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archive->u.tar.fd = result;
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mode = archive->u.tar.tarstat.st_mode & 07777;
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if (mode & 0400) mode |= 0100;
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if (mode & 0040) mode |= 0010;
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if (mode & 0004) mode |= 0001;
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mode |= S_IFDIR;
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root = vfs_s_new_inode (me, archive, &archive->u.tar.tarstat);
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root->st.st_mode = mode;
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root->u.tar.data_offset = -1;
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root->st.st_nlink++;
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root->st.st_dev = MEDATA->rdev++;
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vfs_s_add_dots (me, root, NULL);
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archive->root = root;
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return result;
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}
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static union record rec_buf;
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static union record *
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get_next_record (vfs_s_super *archive, int tard)
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{
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int n;
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n = mc_read (tard, rec_buf.charptr, RECORDSIZE);
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if (n != RECORDSIZE)
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return NULL; /* An error has occurred */
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current_tar_position += RECORDSIZE;
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return &rec_buf;
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}
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static void skip_n_records (vfs_s_super *archive, int tard, int n)
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{
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mc_lseek (tard, n * RECORDSIZE, SEEK_CUR);
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current_tar_position += n * RECORDSIZE;
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}
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static void fill_stat_from_header (vfs *me, struct stat *st, union record *header)
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{
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st->st_mode = from_oct (8, header->header.mode);
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/* Adjust st->st_mode because there are tar-files with
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* linkflag==LF_SYMLINK and S_ISLNK(mod)==0. I don't
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* know about the other modes but I think I cause no new
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* problem when I adjust them, too. -- Norbert.
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*/
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if (header->header.linkflag == LF_DIR) {
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st->st_mode |= S_IFDIR;
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} else if (header->header.linkflag == LF_SYMLINK) {
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st->st_mode |= S_IFLNK;
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} else if (header->header.linkflag == LF_CHR) {
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st->st_mode |= S_IFCHR;
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} else if (header->header.linkflag == LF_BLK) {
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st->st_mode |= S_IFBLK;
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} else if (header->header.linkflag == LF_FIFO) {
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st->st_mode |= S_IFIFO;
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} else
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st->st_mode |= S_IFREG;
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st->st_rdev = 0;
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if (!strcmp (header->header.magic, TMAGIC)) {
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st->st_uid = *header->header.uname ? finduid (header->header.uname) :
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from_oct (8, header->header.uid);
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st->st_gid = *header->header.gname ? findgid (header->header.gname) :
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from_oct (8, header->header.gid);
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switch (header->header.linkflag) {
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case LF_BLK:
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case LF_CHR:
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st->st_rdev = (from_oct (8, header->header.devmajor) << 8) |
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from_oct (8, header->header.devminor);
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}
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} else { /* Old Unix tar */
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st->st_uid = from_oct (8, header->header.uid);
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st->st_gid = from_oct (8, header->header.gid);
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}
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st->st_size = hstat.st_size;
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st->st_mtime = from_oct (1 + 12, header->header.mtime);
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st->st_atime = from_oct (1 + 12, header->header.atime);
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st->st_ctime = from_oct (1 + 12, header->header.ctime);
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}
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typedef enum {
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STATUS_BADCHECKSUM,
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STATUS_SUCCESS,
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STATUS_EOFMARK,
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STATUS_EOF
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} ReadStatus;
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/*
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* Return 1 for success, 0 if the checksum is bad, EOF on eof,
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* 2 for a record full of zeros (EOF marker).
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*
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*/
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static ReadStatus
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read_header (vfs *me, vfs_s_super *archive, int tard)
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{
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register int i;
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register long sum, signed_sum, recsum;
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register char *p;
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register union record *header;
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static char *next_long_name = NULL, *next_long_link = NULL;
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recurse:
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header = get_next_record (archive, tard);
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if (NULL == header)
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return STATUS_EOF;
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recsum = from_oct (8, header->header.chksum);
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sum = 0; signed_sum = 0;
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p = header->charptr;
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for (i = sizeof (*header); --i >= 0;) {
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/*
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* We can't use unsigned char here because of old compilers,
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* e.g. V7.
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*/
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signed_sum += *p;
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sum += 0xFF & *p++;
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}
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/* Adjust checksum to count the "chksum" field as blanks. */
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for (i = sizeof (header->header.chksum); --i >= 0;) {
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sum -= 0xFF & header->header.chksum[i];
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signed_sum -= (char) header->header.chksum[i];
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}
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sum += ' ' * sizeof header->header.chksum;
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signed_sum += ' ' * sizeof header->header.chksum;
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/*
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* This is a zeroed record...whole record is 0's except
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* for the 8 blanks we faked for the checksum field.
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*/
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if (sum == 8 * ' ')
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return STATUS_EOFMARK;
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if (sum != recsum && signed_sum != recsum)
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return STATUS_BADCHECKSUM;
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/*
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* linkflag on BSDI tar (pax) always '\000'
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*/
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if (header->header.linkflag == '\000' &&
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(i = strlen(header->header.arch_name)) &&
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header->header.arch_name[i - 1] == '/')
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header->header.linkflag = LF_DIR;
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/*
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* Good record. Decode file size and return.
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*/
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if (header->header.linkflag == LF_LINK || header->header.linkflag == LF_DIR)
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hstat.st_size = 0; /* Links 0 size on tape */
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else
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hstat.st_size = from_oct (1 + 12, header->header.size);
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header->header.arch_name[NAMSIZ - 1] = '\0';
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if (header->header.linkflag == LF_LONGNAME
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|| header->header.linkflag == LF_LONGLINK) {
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char **longp;
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char *bp, *data;
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int size, written;
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longp = ((header->header.linkflag == LF_LONGNAME)
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? &next_long_name
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: &next_long_link);
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if (*longp)
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g_free (*longp);
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bp = *longp = g_malloc (hstat.st_size);
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for (size = hstat.st_size;
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size > 0;
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size -= written) {
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data = get_next_record (archive, tard)->charptr;
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if (data == NULL) {
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message_1s (1, MSG_ERROR, _("Unexpected EOF on archive file"));
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return STATUS_BADCHECKSUM;
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}
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written = RECORDSIZE;
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if (written > size)
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written = size;
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memcpy (bp, data, written);
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bp += written;
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}
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#if 0
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if (hstat.st_size > 1)
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bp [hstat.st_size - 1] = 0; /* just to make sure */
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#endif
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goto recurse;
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} else {
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struct stat st;
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struct vfs_s_entry *entry;
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struct vfs_s_inode *inode, *parent;
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long data_position;
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char *q;
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int len;
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char *current_file_name, *current_link_name;
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current_link_name = (next_long_link
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? next_long_link
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: g_strdup (header->header.arch_linkname));
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len = strlen (current_link_name);
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if (len > 1 && current_link_name [len - 1] == '/')
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current_link_name[len - 1] = 0;
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current_file_name = (next_long_name
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? next_long_name
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: g_strdup (header->header.arch_name));
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len = strlen (current_file_name);
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if (current_file_name[len - 1] == '/') {
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current_file_name[len - 1] = 0;
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}
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data_position = current_tar_position;
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p = strrchr (current_file_name, '/');
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if (p == NULL) {
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p = current_file_name;
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q = current_file_name + len; /* "" */
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} else {
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*(p++) = 0;
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q = current_file_name;
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}
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parent = vfs_s_find_inode (me, archive->root, q, LINK_NO_FOLLOW, FL_MKDIR);
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if (parent == NULL) {
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message_1s (1, MSG_ERROR, _("Inconsistent tar archive"));
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return STATUS_BADCHECKSUM;
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}
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if (header->header.linkflag == LF_LINK) {
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inode = vfs_s_find_inode (me, archive->root, current_link_name, LINK_NO_FOLLOW, 0);
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if (inode == NULL) {
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message_1s (1, MSG_ERROR, _("Inconsistent tar archive"));
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} else {
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entry = vfs_s_new_entry(me, p, inode);
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vfs_s_insert_entry(me, parent, entry);
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g_free (current_link_name);
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goto done;
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}
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}
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fill_stat_from_header (me, &st, header);
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inode = vfs_s_new_inode (me, archive, &st);
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inode->u.tar.data_offset = data_position;
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if (*current_link_name) {
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inode->linkname = current_link_name;
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} else if (current_link_name != next_long_link) {
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g_free (current_link_name);
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}
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entry = vfs_s_new_entry (me, p, inode);
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vfs_s_insert_entry (me, parent, entry);
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g_free (current_file_name);
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done:
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next_long_link = next_long_name = NULL;
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if (header->header.isextended) {
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while (get_next_record (archive, tard)->ext_hdr.isextended);
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inode->u.tar.data_offset = current_tar_position;
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}
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return STATUS_SUCCESS;
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}
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}
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/*
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* Main loop for reading an archive.
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* Returns 0 on success, -1 on error.
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*/
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static int open_archive (vfs *me, vfs_s_super *archive, char *name, char *op)
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{
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ReadStatus status = STATUS_EOFMARK; /* Initial status at start of archive */
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ReadStatus prev_status;
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int tard;
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current_tar_position = 0;
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if ((tard = tar_open_archive (me, name, archive)) == -1) /* Open for reading */
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return -1;
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for (;;) {
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prev_status = status;
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status = read_header (me, archive, tard);
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switch (status) {
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case STATUS_SUCCESS:
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skip_n_records (archive, tard, (hstat.st_size + RECORDSIZE - 1) / RECORDSIZE);
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continue;
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/*
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* Invalid header:
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*
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* If the previous header was good, tell them
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* that we are skipping bad ones.
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*/
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case STATUS_BADCHECKSUM:
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switch (prev_status){
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/* Error on first record */
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case STATUS_EOFMARK:
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message_2s (1, MSG_ERROR, _("Hmm,...\n%s\ndoesn't look like a tar archive."), name);
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/* FALL THRU */
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/* Error after header rec */
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case STATUS_SUCCESS:
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/* Error after error */
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case STATUS_BADCHECKSUM:
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return -1;
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case STATUS_EOF:
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return 0;
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}
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/* Record of zeroes */
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case STATUS_EOFMARK:
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status = prev_status; /* If error after 0's */
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/* FALL THRU */
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case STATUS_EOF: /* End of archive */
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break;
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}
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break;
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};
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return 0;
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}
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static void *tar_super_check(vfs *me, char *archive_name, char *op)
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{
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static struct stat stat_buf;
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if (mc_stat (archive_name, &stat_buf))
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return NULL;
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return &stat_buf;
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}
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static int tar_super_same(vfs *me, struct vfs_s_super *parc, char *archive_name, char *op, void *cookie)
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{
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struct stat *archive_stat = cookie; /* stat of main archive */
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if (strcmp (parc->name, archive_name)) return 0;
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if (vfs_uid && (!(archive_stat->st_mode & 0004)))
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if ((archive_stat->st_gid != vfs_gid) || !(archive_stat->st_mode & 0040))
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if ((archive_stat->st_uid != vfs_uid) || !(archive_stat->st_mode & 0400))
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return 0;
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/* Has the cached archive been changed on the disk? */
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if (parc->u.tar.tarstat.st_mtime < archive_stat->st_mtime) { /* Yes, reload! */
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(*vfs_tarfs_ops.free) ((vfsid) parc);
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vfs_rmstamp (&vfs_tarfs_ops, (vfsid) parc, 0);
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return 2;
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}
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/* Hasn't been modified, give it a new timeout */
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vfs_stamp (&vfs_tarfs_ops, (vfsid) parc);
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return 1;
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}
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static int tar_read (void *fh, char *buffer, int count)
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{
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off_t begin = FH->ino->u.tar.data_offset;
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int fd = FH_SUPER->u.tar.fd;
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vfs *me = FH_SUPER->me;
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if (mc_lseek (fd, begin + FH->pos, SEEK_SET) !=
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begin + FH->pos) ERRNOR (EIO, -1);
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count = MIN(count, FH->ino->st.st_size - FH->pos);
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if ((count = mc_read (fd, buffer, count)) == -1) ERRNOR (errno, -1);
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FH->pos += count;
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return count;
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}
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static int tar_ungetlocalcopy (vfs *me, char *path, char *local, int has_changed)
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{
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/* We do just nothing. (We are read only and do not need to free local,
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since it will be freed when tar archive will be freed */
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/* We have to report error if file has changed */
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ERRNOR (EROFS, -has_changed);
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}
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static int tar_fh_open (vfs *me, vfs_s_fh *fh, int flags, int mode)
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{
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if ((flags & O_ACCMODE) != O_RDONLY) ERRNOR (EROFS, -1);
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return 0;
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}
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static struct vfs_s_data tarfs_data = {
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NULL,
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0,
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0,
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NULL, /* logfile */
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NULL, /* init_inode */
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NULL, /* free_inode */
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NULL, /* init_entry */
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tar_super_check,
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tar_super_same,
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|
open_archive,
|
|
tar_free_archive,
|
|
|
|
tar_fh_open, /* fh_open */
|
|
NULL, /* fh_close */
|
|
|
|
vfs_s_find_entry_tree,
|
|
NULL,
|
|
NULL
|
|
};
|
|
|
|
vfs vfs_tarfs_ops =
|
|
{
|
|
NULL, /* This is place of next pointer */
|
|
"tarfs",
|
|
0, /* flags */
|
|
"utar", /* prefix */
|
|
&tarfs_data,
|
|
0, /* errno */
|
|
NULL,
|
|
NULL,
|
|
vfs_s_fill_names,
|
|
NULL,
|
|
|
|
vfs_s_open,
|
|
vfs_s_close,
|
|
tar_read,
|
|
NULL,
|
|
|
|
vfs_s_opendir,
|
|
vfs_s_readdir,
|
|
vfs_s_closedir,
|
|
vfs_s_telldir,
|
|
vfs_s_seekdir,
|
|
|
|
vfs_s_stat,
|
|
vfs_s_lstat,
|
|
vfs_s_fstat,
|
|
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
|
|
vfs_s_readlink,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
|
|
NULL,
|
|
vfs_s_chdir,
|
|
vfs_s_ferrno,
|
|
vfs_s_lseek,
|
|
NULL,
|
|
|
|
vfs_s_getid,
|
|
vfs_s_nothingisopen,
|
|
vfs_s_free,
|
|
|
|
vfs_s_getlocalcopy,
|
|
tar_ungetlocalcopy,
|
|
|
|
NULL, /* mkdir */
|
|
NULL,
|
|
NULL,
|
|
NULL
|
|
|
|
MMAPNULL
|
|
};
|