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Add tagging of filter-processed entries with custom XATTR.

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Add magic number based detection of JPEG and PNM formats.
This commit is contained in:
Moinak Ghosh 2014-09-11 20:29:53 +05:30
parent 08a30d270d
commit 3e9a46a602
7 changed files with 111 additions and 23 deletions
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11
.gitignore vendored
View file

@ -13,3 +13,14 @@ core.*
*.kate-swp
bsc/bsc
*.a
*.lo
config.h
config.log
config.status
*.la
libtool
.deps
.dirstamp
stamp-h1
.libs
buildtmp

2
archive/libarchive-3.1.2/libarchive/archive_entry.h
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@ -505,7 +505,7 @@ __LA_DECL void archive_entry_xattr_delete_entry(struct archive_entry *,
const char * /* name */);
__LA_DECL int archive_entry_has_xattr(struct archive_entry *entry,
const char * /* name */, const void ** /* value */,
size_t * /* size */)
size_t * /* size */);
/*
* To retrieve the xattr list, first "reset", then repeatedly ask for the

15
archive/pc_arc_filter.c
View file

@ -92,6 +92,21 @@ add_filters_by_type(struct type_data *typetab, struct filter_flags *ff)
#endif
}
int
type_tag_from_filter_name(struct type_data *typetab, const char *fname, size_t len)
{
size_t i;
for (i = 0; i < NUM_SUB_TYPES; i++)
{
if (typetab[i].filter_name &&
strncmp(fname, typetab[i].filter_name, len) == 0)
{
return (i << 3);
}
}
return (TYPE_UNKNOWN);
}
static void
ensure_buffer(struct scratch_buffer *sdat, uint64_t len)
{

3
archive/pc_arc_filter.h
View file

@ -39,6 +39,7 @@ extern "C" {
#define FILTER_RETURN_SKIP (1)
#define FILTER_RETURN_ERROR (-1)
#define FILTER_XATTR_ENTRY "_._pc_filter_xattr"
struct filter_info {
struct archive *source_arc;
@ -62,6 +63,8 @@ struct type_data {
};
void add_filters_by_type(struct type_data *typetab, struct filter_flags *ff);
int type_tag_from_filter_name(struct type_data *typetab, const char *fname,
size_t len);
#ifdef __cplusplus
}

100
archive/pc_archive.c
View file

@ -887,6 +887,25 @@ process_by_filter(int fd, int *typ, struct archive *target_arc,
return (wrtn);
}
static int
write_header(struct archive *arc, struct archive_entry *entry)
{
int rv;
rv = archive_write_header(arc, entry);
if (rv != ARCHIVE_OK) {
if (rv == ARCHIVE_FATAL || rv == ARCHIVE_FAILED) {
log_msg(LOG_ERR, 0, "%s: %s",
archive_entry_sourcepath(entry), archive_error_string(arc));
return (-1);
} else {
log_msg(LOG_WARN, 0, "%s: %s",
archive_entry_sourcepath(entry), archive_error_string(arc));
}
}
return (0);
}
/*
* Routines to archive members and write the file data to the callback. Portions of
* the following code is adapted from some of the Libarchive bsdtar code.
@ -914,7 +933,14 @@ copy_file_data(pc_ctx_t *pctx, struct archive *arc, struct archive_entry *entry,
if (typ != TYPE_UNKNOWN) {
if (typetab[(typ >> 3)].filter_func != NULL) {
int64_t rv;
char *fname = typetab[(typ >> 3)].filter_name;
archive_entry_xattr_add_entry(entry, FILTER_XATTR_ENTRY,
fname, strlen(fname));
if (write_header(arc, entry) == -1) {
close(fd);
return (-1);
}
pctx->ctype = typ;
rv = process_by_filter(fd, &(pctx->ctype), arc, NULL, entry, 1);
if (rv == FILTER_RETURN_ERROR) {
@ -924,6 +950,11 @@ copy_file_data(pc_ctx_t *pctx, struct archive *arc, struct archive_entry *entry,
close(fd);
return (ARCHIVE_OK);
}
} else {
if (write_header(arc, entry) == -1) {
close(fd);
return (-1);
}
}
}
@ -958,9 +989,17 @@ do_map:
if (typ != TYPE_UNKNOWN) {
if (typetab[(typ >> 3)].filter_func != NULL) {
int64_t rv;
munmap(mapbuf, len);
char *fname = typetab[(typ >> 3)].filter_name;
rv = process_by_filter(fd, &(pctx->ctype), arc, NULL, entry, 1);
archive_entry_xattr_add_entry(entry, FILTER_XATTR_ENTRY,
fname, strlen(fname));
if (write_header(arc, entry) == -1) {
close(fd);
return (-1);
}
munmap(mapbuf, len);
rv = process_by_filter(fd, &(pctx->ctype), arc, NULL, entry, 1);
if (rv == FILTER_RETURN_ERROR) {
return (-1);
} else if (rv == FILTER_RETURN_SKIP) {
@ -972,6 +1011,11 @@ do_map:
return (ARCHIVE_OK);
}
}
} else {
if (write_header(arc, entry) == -1) {
close(fd);
return (-1);
}
}
}
typ = TYPE_COMPRESSED; // Need to avoid calling detect_type_by_data subsequently.
@ -998,22 +1042,15 @@ do_map:
static int
write_entry(pc_ctx_t *pctx, struct archive *arc, struct archive_entry *entry, int typ)
{
int rv;
rv = archive_write_header(arc, entry);
if (rv != ARCHIVE_OK) {
if (rv == ARCHIVE_FATAL || rv == ARCHIVE_FAILED) {
log_msg(LOG_ERR, 0, "%s: %s",
archive_entry_sourcepath(entry), archive_error_string(arc));
return (-1);
} else {
log_msg(LOG_WARN, 0, "%s: %s",
archive_entry_sourcepath(entry), archive_error_string(arc));
}
}
/*
* If entry has data we postpone writing the header till we have
* determined whether the entry type has an associated filter.
*/
if (archive_entry_size(entry) > 0) {
return (copy_file_data(pctx, arc, entry, typ));
} else {
if (write_header(arc, entry) == -1)
return (-1);
}
return (0);
@ -1213,7 +1250,19 @@ archive_extract_entry(struct archive *a, struct archive_entry *entry,
struct archive *ad, int typ)
{
int r, r2;
char *filter_name;
size_t name_size;
/*
* If the entry is tagged with our custom xattr we get the filter which
* processed it and set the proper type tag.
*/
if (archive_entry_has_xattr(entry, FILTER_XATTR_ENTRY,
(const void **)&filter_name, &name_size))
{
typ = type_tag_from_filter_name(typetab, filter_name, name_size);
archive_entry_xattr_delete_entry(entry, FILTER_XATTR_ENTRY);
}
r = archive_write_header(ad, entry);
if (r < ARCHIVE_WARN)
r = ARCHIVE_WARN;
@ -1545,10 +1594,6 @@ out:
/*
* Detect a few file types from looking at magic signatures.
* NOTE: Jpeg files must be detected via '.jpg' or '.jpeg' (case-insensitive)
* extensions. Do not add Jpeg/PNM header detection here. it will break
* context based PackJPG/PackPNM processing. Jpeg files not having proper
* extension must not be processed via PackJPG.
*/
static int
detect_type_by_data(uchar_t *buf, size_t len)
@ -1578,6 +1623,14 @@ detect_type_by_data(uchar_t *buf, size_t len)
}
}
// Jpegs
if (len > 9 && buf[0] == 0xFF && buf[1] == 0xD8) {
if (strncmp((char *)&buf[6], "Exif", 4) == 0 ||
strncmp((char *)&buf[6], "JFIF", 4) == 0) {
return (TYPE_BINARY|TYPE_JPEG);
}
}
if (U32_P(buf) == ELFINT) { // Regular ELF, check for 32/64-bit, core dump
if (*(buf + 16) != 4) {
if (*(buf + 4) == 2) {
@ -1634,7 +1687,12 @@ detect_type_by_data(uchar_t *buf, size_t len)
if (U32_P(buf) == WVPK || U32_P(buf) == TTA1)
return (TYPE_BINARY|TYPE_COMPRESSED|TYPE_AUDIO_COMPRESSED);
// MSDOS COM types, two byte and one byte magic numbers are checked
// PNM files
if (identify_pnm_type(buf, len)) {
return (TYPE_TEXT|TYPE_PNM);
}
// MSDOS COM types, two byte and one byte magic numbers are checked
// after all other multi-byte magic number checks.
if (buf[0] == 0xe9 || buf[0] == 0xeb) {
if (LE16(U16_P(buf + 0x1fe)) == 0xaa55)

1
config
View file

@ -692,6 +692,7 @@ echo "*************** Running configure in libarchive ****************"
cat Makefile | sed '
s@$(BUILT_SOURCES)@@
s@$(libarchive_test_SOURCES)@@
s@$(libarchive_man_MANS)@@
' > Makefile.new
mv Makefile.new Makefile
)

2
utils/utils.h
View file

@ -277,7 +277,7 @@ typedef enum {
/*
* Sub-types.
*/
#define NUM_SUB_TYPES 28
#define NUM_SUB_TYPES 31
TYPE_EXE32 = 8,
TYPE_JPEG = 16,
TYPE_MARKUP = 24,