mc/vfs/cpio.c

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/* Virtual File System: GNU Tar file system.
Copyright (C) 2000 The Free Software Foundation
Written by: 2000 Jan Hudec
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include <config.h>
#include <errno.h>
#include "utilvfs.h"
#include "gc.h" /* vfs_rmstamp */
#include "xdirentry.h"
enum {
STATUS_START,
STATUS_OK,
STATUS_TRAIL,
STATUS_FAIL,
STATUS_EOF
};
enum {
CPIO_UNKNOWN = 0, /* Not determined yet */
CPIO_BIN, /* Binary format */
CPIO_BINRE, /* Binary format, reverse endianity */
CPIO_OLDC, /* Old ASCII format */
CPIO_NEWC, /* New ASCII format */
CPIO_CRC /* New ASCII format + CRC */
};
static struct vfs_class vfs_cpiofs_ops;
struct old_cpio_header
{
unsigned short c_magic;
short c_dev;
unsigned short c_ino;
unsigned short c_mode;
unsigned short c_uid;
unsigned short c_gid;
unsigned short c_nlink;
short c_rdev;
unsigned short c_mtimes[2];
unsigned short c_namesize;
unsigned short c_filesizes[2];
};
struct new_cpio_header
{
unsigned short c_magic;
unsigned long c_ino;
unsigned long c_mode;
unsigned long c_uid;
unsigned long c_gid;
unsigned long c_nlink;
unsigned long c_mtime;
unsigned long c_filesize;
long c_dev;
long c_devmin;
long c_rdev;
long c_rdevmin;
unsigned long c_namesize;
unsigned long c_chksum;
};
struct defer_inode {
struct defer_inode *next;
unsigned long inumber;
unsigned short device;
struct vfs_s_inode *inode;
};
static int cpio_position;
static int cpio_find_head(struct vfs_class *me, struct vfs_s_super *super);
static int cpio_read_bin_head(struct vfs_class *me, struct vfs_s_super *super);
static int cpio_read_oldc_head(struct vfs_class *me, struct vfs_s_super *super);
static int cpio_read_crc_head(struct vfs_class *me, struct vfs_s_super *super);
static int cpio_create_entry(struct vfs_class *me, struct vfs_s_super *super, struct stat *stat, char *name);
static int cpio_read(void *fh, char *buffer, int count);
#define CPIO_POS(super) cpio_position
/* If some time reentrancy should be needed change it to */
/* #define CPIO_POS(super) (super)->u.arch.fd */
#define CPIO_SEEK_SET(super, where) mc_lseek((super)->u.arch.fd, CPIO_POS(super) = (where), SEEK_SET)
#define CPIO_SEEK_CUR(super, where) mc_lseek((super)->u.arch.fd, CPIO_POS(super) += (where), SEEK_SET)
static struct defer_inode *
cpio_defer_find (struct defer_inode *l, struct defer_inode *i)
{
if (!l)
return NULL;
return l->inumber == i->inumber
&& l->device == i->device ? l : cpio_defer_find (l->next, i);
}
static int cpio_skip_padding(struct vfs_s_super *super)
{
switch(super->u.arch.type) {
case CPIO_BIN:
case CPIO_BINRE:
return CPIO_SEEK_CUR(super, (2 - (CPIO_POS(super) % 2)) % 2);
case CPIO_NEWC:
case CPIO_CRC:
return CPIO_SEEK_CUR(super, (4 - (CPIO_POS(super) % 4)) % 4);
case CPIO_OLDC:
return CPIO_POS(super);
default:
g_assert_not_reached();
return 42; /* & the compiler is happy :-) */
}
}
static void cpio_free_archive(struct vfs_class *me, struct vfs_s_super *super)
{
if(super->u.arch.fd != -1)
mc_close(super->u.arch.fd);
}
static int
cpio_open_cpio_file (struct vfs_class *me, struct vfs_s_super *super,
const char *name)
{
int fd, type;
mode_t mode;
struct vfs_s_inode *root;
if ((fd = mc_open (name, O_RDONLY)) == -1) {
message (1, MSG_ERROR, _("Cannot open cpio archive\n%s"), name);
return -1;
}
super->name = g_strdup (name);
super->u.arch.fd = -1; /* for now */
mc_stat (name, &(super->u.arch.st));
super->u.arch.type = CPIO_UNKNOWN;
type = get_compression_type (fd);
if (type != COMPRESSION_NONE) {
char *s;
mc_close (fd);
s = g_strconcat (name, decompress_extension (type), NULL);
if ((fd = mc_open (s, O_RDONLY)) == -1) {
message (1, MSG_ERROR, _("Cannot open cpio archive\n%s"), s);
g_free (s);
return -1;
}
g_free (s);
}
super->u.arch.fd = fd;
mode = super->u.arch.st.st_mode & 07777;
mode |= (mode & 0444) >> 2; /* set eXec where Read is */
mode |= S_IFDIR;
root = vfs_s_new_inode (me, super, &(super->u.arch.st));
root->st.st_mode = mode;
root->data_offset = -1;
root->st.st_nlink++;
root->st.st_dev = MEDATA->rdev++;
super->root = root;
CPIO_SEEK_SET (super, 0);
return fd;
}
static int cpio_read_head(struct vfs_class *me, struct vfs_s_super *super)
{
switch(cpio_find_head(me, super)) {
case CPIO_UNKNOWN:
return -1;
case CPIO_BIN:
case CPIO_BINRE:
return cpio_read_bin_head(me, super);
case CPIO_OLDC:
return cpio_read_oldc_head(me, super);
case CPIO_NEWC:
case CPIO_CRC:
return cpio_read_crc_head(me, super);
default:
g_assert_not_reached();
return 42; /* & the compiler is happy :-) */
}
}
#define MAGIC_LENGTH (6) /* How many bytes we have to read ahead */
#define SEEKBACK CPIO_SEEK_CUR(super, ptr - top)
#define RETURN(x) return(super->u.arch.type = (x))
#define TYPEIS(x) ((super->u.arch.type == CPIO_UNKNOWN) || (super->u.arch.type == (x)))
static int cpio_find_head(struct vfs_class *me, struct vfs_s_super *super)
{
char buf[256];
int ptr = 0;
int top = 0;
int tmp;
top = mc_read(super->u.arch.fd, buf, 256);
CPIO_POS(super) += top;
for(;;) {
if(ptr + MAGIC_LENGTH >= top) {
if(top > 128) {
memmove(buf, buf + top - 128, 128);
top = 128;
ptr -= top - 128;
}
if((tmp = mc_read(super->u.arch.fd, buf, top)) == 0 || tmp == -1) {
message (1, MSG_ERROR, _("Premature end of cpio archive\n%s"), super->name);
cpio_free_archive(me, super);
return CPIO_UNKNOWN;
}
top += tmp;
}
if(TYPEIS(CPIO_BIN) && ((*(unsigned short *)(buf + ptr)) == 070707)) {
SEEKBACK; RETURN(CPIO_BIN);
} else if(TYPEIS(CPIO_BINRE) && ((*(unsigned short *)(buf + ptr)) == GUINT16_SWAP_LE_BE_CONSTANT(070707))) {
SEEKBACK; RETURN(CPIO_BINRE);
} else if(TYPEIS(CPIO_OLDC) && (!strncmp(buf + ptr, "070707", 6))) {
SEEKBACK; RETURN(CPIO_OLDC);
} else if(TYPEIS(CPIO_NEWC) && (!strncmp(buf + ptr, "070701", 6))) {
SEEKBACK; RETURN(CPIO_NEWC);
} else if(TYPEIS(CPIO_CRC) && (!strncmp(buf + ptr, "070702", 6))) {
SEEKBACK; RETURN(CPIO_CRC);
};
ptr++;
}
}
#undef RETURN
#undef SEEKBACK
#define HEAD_LENGTH (26)
static int cpio_read_bin_head(struct vfs_class *me, struct vfs_s_super *super)
{
struct old_cpio_header buf;
int len;
char *name;
struct stat stat;
if((len = mc_read(super->u.arch.fd, (char *)&buf, HEAD_LENGTH)) < HEAD_LENGTH)
return STATUS_EOF;
CPIO_POS(super) += len;
if(super->u.arch.type == CPIO_BINRE) {
int i;
for(i = 0; i < (HEAD_LENGTH >> 1); i++)
((short *)&buf)[i] = GUINT16_SWAP_LE_BE(((short *)&buf)[i]);
}
g_assert(buf.c_magic == 070707);
name = g_malloc(buf.c_namesize);
if((len = mc_read(super->u.arch.fd, name, buf.c_namesize)) < buf.c_namesize) {
g_free(name);
return STATUS_EOF;
}
CPIO_POS(super) += len;
cpio_skip_padding(super);
if(!strcmp("TRAILER!!!", name)) { /* We got to the last record */
g_free(name);
return STATUS_TRAIL;
}
stat.st_dev = buf.c_dev;
stat.st_ino = buf.c_ino;
stat.st_mode = buf.c_mode;
stat.st_nlink = buf.c_nlink;
stat.st_uid = buf.c_uid;
stat.st_gid = buf.c_gid;
stat.st_rdev = buf.c_rdev;
stat.st_size = (buf.c_filesizes[0] << 16) | buf.c_filesizes[1];
stat.st_atime = stat.st_mtime = stat.st_ctime = (buf.c_mtimes[0] << 16) | buf.c_mtimes[1];
return cpio_create_entry(me, super, &stat, name);
}
#undef HEAD_LENGTH
#define HEAD_LENGTH (76)
static int cpio_read_oldc_head(struct vfs_class *me, struct vfs_s_super *super)
{
struct new_cpio_header hd;
struct stat stat;
char buf[HEAD_LENGTH + 1];
int len;
char *name;
if((len = mc_read(super->u.arch.fd, buf, HEAD_LENGTH)) < HEAD_LENGTH)
return STATUS_EOF;
CPIO_POS(super) += len;
buf[HEAD_LENGTH] = 0;
if(sscanf(buf, "070707%6lo%6lo%6lo%6lo%6lo%6lo%6lo%11lo%6lo%11lo",
&hd.c_dev, &hd.c_ino, &hd.c_mode, &hd.c_uid, &hd.c_gid,
&hd.c_nlink, &hd.c_rdev, &hd.c_mtime,
&hd.c_namesize, &hd.c_filesize) < 10) {
message (1, MSG_ERROR, _("Corrupted cpio header encountered in\n%s"), super->name);
return STATUS_FAIL;
}
name = g_malloc(hd.c_namesize);
if((len = mc_read(super->u.arch.fd, name, hd.c_namesize)) == -1 ||
(unsigned long) len < hd.c_namesize) {
g_free (name);
return STATUS_EOF;
}
CPIO_POS(super) += len;
cpio_skip_padding(super);
if(!strcmp("TRAILER!!!", name)) { /* We got to the last record */
g_free(name);
return STATUS_TRAIL;
}
stat.st_dev = hd.c_dev;
stat.st_ino = hd.c_ino;
stat.st_mode = hd.c_mode;
stat.st_nlink = hd.c_nlink;
stat.st_uid = hd.c_uid;
stat.st_gid = hd.c_gid;
stat.st_rdev = hd.c_rdev;
stat.st_size = hd.c_filesize;
stat.st_atime = stat.st_mtime = stat.st_ctime = hd.c_mtime;
return cpio_create_entry(me, super, &stat, name);
}
#undef HEAD_LENGTH
#define HEAD_LENGTH (110)
static int cpio_read_crc_head(struct vfs_class *me, struct vfs_s_super *super)
{
struct new_cpio_header hd;
struct stat stat;
char buf[HEAD_LENGTH + 1];
int len;
char *name;
if((len = mc_read(super->u.arch.fd, buf, HEAD_LENGTH)) < HEAD_LENGTH)
return STATUS_EOF;
CPIO_POS(super) += len;
buf[HEAD_LENGTH] = 0;
if(sscanf(buf, "%6ho%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx",
&hd.c_magic, &hd.c_ino, &hd.c_mode, &hd.c_uid, &hd.c_gid,
&hd.c_nlink, &hd.c_mtime, &hd.c_filesize,
&hd.c_dev, &hd.c_devmin, &hd.c_rdev, &hd.c_rdevmin,
&hd.c_namesize, &hd.c_chksum) < 14) {
message (1, MSG_ERROR, _("Corrupted cpio header encountered in\n%s"),
super->name);
return STATUS_FAIL;
}
if((super->u.arch.type == CPIO_NEWC && hd.c_magic != 070701) ||
(super->u.arch.type == CPIO_CRC && hd.c_magic != 070702))
return STATUS_FAIL;
name = g_malloc(hd.c_namesize);
if((len = mc_read(super->u.arch.fd, name, hd.c_namesize)) != -1 &&
(unsigned long) len < hd.c_namesize) {
g_free (name);
return STATUS_EOF;
}
CPIO_POS(super) += len;
cpio_skip_padding(super);
if(!strcmp("TRAILER!!!", name)) { /* We got to the last record */
g_free(name);
return STATUS_TRAIL;
}
stat.st_dev = (hd.c_dev << 8) + hd.c_devmin;
stat.st_ino = hd.c_ino;
stat.st_mode = hd.c_mode;
stat.st_nlink = hd.c_nlink;
stat.st_uid = hd.c_uid;
stat.st_gid = hd.c_gid;
stat.st_rdev = (hd.c_rdev << 8) + hd.c_rdevmin;
stat.st_size = hd.c_filesize;
stat.st_atime = stat.st_mtime = stat.st_ctime = hd.c_mtime;
return cpio_create_entry(me, super, &stat, name);
}
static int
cpio_create_entry (struct vfs_class *me, struct vfs_s_super *super,
struct stat *stat, char *name)
{
struct vfs_s_inode *inode = NULL;
struct vfs_s_inode *root = super->root;
struct vfs_s_entry *entry = NULL;
char *tn;
switch (stat->st_mode & S_IFMT) { /* For case of HP/UX archives */
case S_IFCHR:
case S_IFBLK:
#ifdef S_IFSOCK
case S_IFSOCK:
#endif
#ifdef S_IFIFO
case S_IFIFO:
#endif
if ((stat->st_size != 0) && (stat->st_rdev == 0x0001)) {
stat->st_rdev = (unsigned) stat->st_size;
stat->st_size = 0;
}
break;
default:
break;
}
if ((stat->st_nlink > 1) && (super->u.arch.type == CPIO_NEWC || super->u.arch.type == CPIO_CRC)) { /* For case of hardlinked files */
struct defer_inode i, *l;
i.inumber = stat->st_ino;
i.device = stat->st_dev;
i.inode = NULL;
if ((l = cpio_defer_find (super->u.arch.deferred, &i)) != NULL) {
inode = l->inode;
if (inode->st.st_size && stat->st_size
&& (inode->st.st_size != stat->st_size)) {
message (1, MSG_ERROR,
_
("Inconsistent hardlinks of\n%s\nin cpio archive\n%s"),
name, super->name);
inode = NULL;
}
}
}
for (tn = name + strlen (name) - 1; tn >= name && *tn == PATH_SEP; tn--)
*tn = 0;
if ((tn = strrchr (name, PATH_SEP))) {
*tn = 0;
root = vfs_s_find_inode (me, super, name, LINK_FOLLOW, FL_MKDIR);
*tn = PATH_SEP;
tn++;
} else
tn = name;
entry = MEDATA->find_entry (me, root, tn, LINK_FOLLOW, FL_NONE); /* In case entry is already there */
if (entry) { /* This shouldn't happen! (well, it can happen if there is a record for a
file and than a record for a directory it is in; cpio would die with
'No such file or directory' is such case) */
if (!S_ISDIR (entry->ino->st.st_mode)) { /* This can be considered archive inconsistency */
message (1, MSG_ERROR,
_("%s contains duplicate entries! Skipping!"),
super->name);
} else {
entry->ino->st.st_mode = stat->st_mode;
entry->ino->st.st_uid = stat->st_uid;
entry->ino->st.st_gid = stat->st_gid;
entry->ino->st.st_atime = stat->st_atime;
entry->ino->st.st_mtime = stat->st_mtime;
entry->ino->st.st_ctime = stat->st_ctime;
}
} else { /* !entry */
if (!inode) {
inode = vfs_s_new_inode (me, super, stat);
if ((stat->st_nlink > 0) && (super->u.arch.type == CPIO_NEWC || super->u.arch.type == CPIO_CRC)) { /* For case of hardlinked files */
struct defer_inode *i;
i = g_new (struct defer_inode, 1);
i->inumber = stat->st_ino;
i->device = stat->st_dev;
i->inode = inode;
i->next = super->u.arch.deferred;
super->u.arch.deferred = i;
}
}
if (stat->st_size)
inode->data_offset = CPIO_POS (super);
entry = vfs_s_new_entry (me, tn, inode);
vfs_s_insert_entry (me, root, entry);
if (S_ISLNK (stat->st_mode)) {
inode->linkname = g_malloc (stat->st_size + 1);
if (mc_read (super->u.arch.fd, inode->linkname, stat->st_size)
< stat->st_size) {
inode->linkname[0] = 0;
g_free (name);
return STATUS_EOF;
}
inode->linkname[stat->st_size] = 0; /* Linkname stored without terminating \0 !!! */
CPIO_POS (super) += stat->st_size;
cpio_skip_padding (super);
} else {
CPIO_SEEK_CUR (super, stat->st_size);
}
} /* !entry */
g_free (name);
return STATUS_OK;
}
/* Need to CPIO_SEEK_CUR to skip the file at the end of add entry!!!! */
static int
cpio_open_archive (struct vfs_class *me, struct vfs_s_super *super,
const char *name, char *op)
{
int status = STATUS_START;
if (cpio_open_cpio_file (me, super, name) == -1)
return -1;
for (;;) {
status = cpio_read_head (me, super);
switch (status) {
case STATUS_EOF:
message (1, MSG_ERROR, _("Unexpected end of file\n%s"), name);
return 0;
case STATUS_OK:
continue;
case STATUS_TRAIL:
break;
}
break;
}
return 0;
}
/* Remaining functions are exactly same as for tarfs (and were in fact just copied) */
static void *
cpio_super_check (struct vfs_class *me, const char *archive_name, char *op)
{
static struct stat sb;
if (mc_stat (archive_name, &sb))
return NULL;
return &sb;
}
static int
cpio_super_same (struct vfs_class *me, struct vfs_s_super *parc,
const char *archive_name, char *op, void *cookie)
{
struct stat *archive_stat = cookie; /* stat of main archive */
if (strcmp (parc->name, archive_name))
return 0;
/* Has the cached archive been changed on the disk? */
if (parc->u.arch.st.st_mtime < archive_stat->st_mtime) {
/* Yes, reload! */
(*vfs_cpiofs_ops.free) ((vfsid) parc);
vfs_rmstamp (&vfs_cpiofs_ops, (vfsid) parc);
return 2;
}
/* Hasn't been modified, give it a new timeout */
vfs_stamp (&vfs_cpiofs_ops, (vfsid) parc);
return 1;
}
static int cpio_read(void *fh, char *buffer, int count)
{
off_t begin = FH->ino->data_offset;
int fd = FH_SUPER->u.arch.fd;
struct vfs_class *me = FH_SUPER->me;
if (mc_lseek (fd, begin + FH->pos, SEEK_SET) !=
begin + FH->pos) ERRNOR (EIO, -1);
count = MIN(count, FH->ino->st.st_size - FH->pos);
if ((count = mc_read (fd, buffer, count)) == -1) ERRNOR (errno, -1);
FH->pos += count;
return count;
}
static int cpio_fh_open(struct vfs_class *me, struct vfs_s_fh *fh, int flags, int mode)
{
if ((flags & O_ACCMODE) != O_RDONLY) ERRNOR (EROFS, -1);
return 0;
}
void
init_cpiofs (void)
{
static struct vfs_s_subclass cpio_subclass;
cpio_subclass.flags = VFS_S_READONLY;
cpio_subclass.archive_check = cpio_super_check;
cpio_subclass.archive_same = cpio_super_same;
cpio_subclass.open_archive = cpio_open_archive;
cpio_subclass.free_archive = cpio_free_archive;
cpio_subclass.fh_open = cpio_fh_open;
vfs_s_init_class (&vfs_cpiofs_ops, &cpio_subclass);
vfs_cpiofs_ops.name = "cpiofs";
vfs_cpiofs_ops.prefix = "ucpio";
vfs_cpiofs_ops.read = cpio_read;
vfs_cpiofs_ops.setctl = NULL;
vfs_register_class (&vfs_cpiofs_ops);
}