Start the libification of parse_loose_header() by making it return
error codes and data instead of invoking die() by itself. For now
we'll move the relevant die() call to loose_object_info() and
read_loose_object() to keep this change smaller, but in subsequent
commits we'll also libify those.
The reason this makes sense is that with the refactoring of
parse_loose_header_extended() in an earlier commit the public
interface for parse_loose_header() no longer just accepts a "unsigned
long *sizep". Rather it accepts a "struct object_info *", that
structure will be populated with information about the object.
It thus makes sense to further libify the interface so that it stops
calling die() when it encounters OBJ_BAD, and instead rely on its
callers to check the populated "oi->typep".
This also allows us to simplify away the
unpack_loose_header_to_strbuf() function added in
46f034483eb (sha1_file: support reading from a loose object of unknown
type, 2015-05-03). Its code was mostly copy/pasted between it and both
of unpack_loose_header() and unpack_loose_short_header(). We now have
a single unpack_loose_header() function which accepts an optional
"struct strbuf *" instead.
I think the remaining unpack_loose_header() function could be further
simplified, we're carrying some complexity just to be able to emit a
garbage type longer than MAX_HEADER_LEN, we could alternatively just
say "we found a garbage type <first 32 bytes>..." instead, but let's
leave this in place for now.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
object-file.c | 105 ++++++++++++++++++++-----------------------------
object-store.h | 25 ++++++++++--
streaming.c | 7 +++-
3 files changed, 70 insertions(+), 67 deletions(-)
diff --git a/object-file.c b/object-file.c
index 115054389c..d4bdf86657 100644
--- a/object-file.c
+++ b/object-file.c
@@ -1210,11 +1210,12 @@ void *map_loose_object(struct repository *r,
return map_loose_object_1(r, NULL, oid, size);
}
-static int unpack_loose_short_header(git_zstream *stream,
- unsigned char *map, unsigned long mapsize,
- void *buffer, unsigned long bufsiz)
+int unpack_loose_header(git_zstream *stream,
+ unsigned char *map, unsigned long mapsize,
+ void *buffer, unsigned long bufsiz,
+ struct strbuf *header)
{
- int ret;
+ int status;
/* Get the data stream */
memset(stream, 0, sizeof(*stream));
@@ -1225,44 +1226,25 @@ static int unpack_loose_short_header(git_zstream *stream,
git_inflate_init(stream);
obj_read_unlock();
- ret = git_inflate(stream, 0);
+ status = git_inflate(stream, 0);
obj_read_lock();
-
- return ret;
-}
-
-int unpack_loose_header(git_zstream *stream,
- unsigned char *map, unsigned long mapsize,
- void *buffer, unsigned long bufsiz)
-{
- int status = unpack_loose_short_header(stream, map, mapsize,
- buffer, bufsiz);
-
if (status < Z_OK)
return status;
- /* Make sure we have the terminating NUL */
- if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
- return -1;
- return 0;
-}
-
-static int unpack_loose_header_to_strbuf(git_zstream *stream, unsigned char *map,
- unsigned long mapsize, void *buffer,
- unsigned long bufsiz, struct strbuf *header)
-{
- int status;
-
- status = unpack_loose_short_header(stream, map, mapsize, buffer, bufsiz);
- if (status < Z_OK)
- return -1;
-
/*
* Check if entire header is unpacked in the first iteration.
*/
if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
return 0;
+ /*
+ * We have a header longer than MAX_HEADER_LEN. We abort early
+ * unless under we're running as e.g. "cat-file
+ * --allow-unknown-type".
+ */
+ if (!header)
+ return -1;
+
/*
* buffer[0..bufsiz] was not large enough. Copy the partial
* result out to header, and then append the result of further
@@ -1340,9 +1322,7 @@ static void *unpack_loose_rest(git_zstream *stream,
* too permissive for what we want to check. So do an anal
* object header parse by hand.
*/
-int parse_loose_header(const char *hdr,
- struct object_info *oi,
- unsigned int flags)
+int parse_loose_header(const char *hdr, struct object_info *oi)
{
const char *type_buf = hdr;
unsigned long size;
@@ -1364,15 +1344,6 @@ int parse_loose_header(const char *hdr,
type = type_from_string_gently(type_buf, type_len, 1);
if (oi->type_name)
strbuf_add(oi->type_name, type_buf, type_len);
- /*
- * Set type to 0 if its an unknown object and
- * we're obtaining the type using '--allow-unknown-type'
- * option.
- */
- if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
- type = 0;
- else if (type < 0)
- die(_("invalid object type"));
if (oi->typep)
*oi->typep = type;
@@ -1399,7 +1370,14 @@ int parse_loose_header(const char *hdr,
/*
* The length must be followed by a zero byte
*/
- return *hdr ? -1 : type;
+ if (*hdr)
+ return -1;
+
+ /*
+ * The format is valid, but the type may still be bogus. The
+ * Caller needs to check its oi->typep.
+ */
+ return 0;
}
static int loose_object_info(struct repository *r,
@@ -1410,9 +1388,12 @@ static int loose_object_info(struct repository *r,
unsigned long mapsize;
void *map;
git_zstream stream;
+ int hdr_ret;
char hdr[MAX_HEADER_LEN];
struct strbuf hdrbuf = STRBUF_INIT;
unsigned long size_scratch;
+ enum object_type type_scratch;
+ int allow_unknown = flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
if (oi->delta_base_oid)
oidclr(oi->delta_base_oid);
@@ -1443,27 +1424,23 @@ static int loose_object_info(struct repository *r,
if (!oi->sizep)
oi->sizep = &size_scratch;
+ if (!oi->typep)
+ oi->typep = &type_scratch;
if (oi->disk_sizep)
*oi->disk_sizep = mapsize;
- if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
- if (unpack_loose_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
- status = error(_("unable to unpack %s header with --allow-unknown-type"),
- oid_to_hex(oid));
- } else if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
+
+ hdr_ret = unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr),
+ allow_unknown ? &hdrbuf : NULL);
+ if (hdr_ret < 0) {
status = error(_("unable to unpack %s header"),
oid_to_hex(oid));
}
-
- if (status < 0) {
- /* Do nothing */
- } else if (hdrbuf.len) {
- if ((status = parse_loose_header(hdrbuf.buf, oi, flags)) < 0)
- status = error(_("unable to parse %s header with --allow-unknown-type"),
- oid_to_hex(oid));
- } else if ((status = parse_loose_header(hdr, oi, flags)) < 0) {
+ if (!status && parse_loose_header(hdrbuf.len ? hdrbuf.buf : hdr, oi) < 0) {
status = error(_("unable to parse %s header"), oid_to_hex(oid));
}
+ if (!allow_unknown && *oi->typep < 0)
+ die(_("invalid object type"));
if (status >= 0 && oi->contentp) {
*oi->contentp = unpack_loose_rest(&stream, hdr,
@@ -1481,7 +1458,8 @@ static int loose_object_info(struct repository *r,
*oi->typep = status;
if (oi->sizep == &size_scratch)
oi->sizep = NULL;
- strbuf_release(&hdrbuf);
+ if (oi->typep == &type_scratch)
+ oi->typep = NULL;
oi->whence = OI_LOOSE;
return (status < 0) ? status : 0;
}
@@ -2547,6 +2525,7 @@ int read_loose_object(const char *path,
git_zstream stream;
char hdr[MAX_HEADER_LEN];
struct object_info oi = OBJECT_INFO_INIT;
+ oi.typep = type;
oi.sizep = size;
*contents = NULL;
@@ -2557,17 +2536,19 @@ int read_loose_object(const char *path,
goto out;
}
- if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
+ if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr),
+ NULL) < 0) {
error(_("unable to unpack header of %s"), path);
goto out;
}
- *type = parse_loose_header(hdr, &oi, 0);
- if (*type < 0) {
+ if (parse_loose_header(hdr, &oi) < 0) {
error(_("unable to parse header of %s"), path);
git_inflate_end(&stream);
goto out;
}
+ if (*type < 0)
+ die(_("invalid object type"));
if (*type == OBJ_BLOB && *size > big_file_threshold) {
if (check_stream_oid(&stream, hdr, *size, path, expected_oid) < 0)
diff --git a/object-store.h b/object-store.h
index d443964447..740edcac30 100644
--- a/object-store.h
+++ b/object-store.h
@@ -477,11 +477,30 @@ int for_each_object_in_pack(struct packed_git *p,
int for_each_packed_object(each_packed_object_fn, void *,
enum for_each_object_flags flags);
+/**
+ * unpack_loose_header() initializes the data stream needed to unpack
+ * a loose object header.
+ *
+ * Returns 0 on success. Returns negative values on error.
+ *
+ * It will only parse up to MAX_HEADER_LEN bytes unless an optional
+ * "hdrbuf" argument is non-NULL. This is intended for use with
+ * OBJECT_INFO_ALLOW_UNKNOWN_TYPE to extract the bad type for (error)
+ * reporting. The full header will be extracted to "hdrbuf" for use
+ * with parse_loose_header().
+ */
int unpack_loose_header(git_zstream *stream, unsigned char *map,
unsigned long mapsize, void *buffer,
- unsigned long bufsiz);
-int parse_loose_header(const char *hdr, struct object_info *oi,
- unsigned int flags);
+ unsigned long bufsiz, struct strbuf *hdrbuf);
+
+/**
+ * parse_loose_header() parses the starting "<type> <len>\0" of an
+ * object. If it doesn't follow that format -1 is returned. To check
+ * the validity of the <type> populate the "typep" in the "struct
+ * object_info". It will be OBJ_BAD if the object type is unknown.
+ */
+int parse_loose_header(const char *hdr, struct object_info *oi);
+
int check_object_signature(struct repository *r, const struct object_id *oid,
void *buf, unsigned long size, const char *type);
int finalize_object_file(const char *tmpfile, const char *filename);
diff --git a/streaming.c b/streaming.c
index 8beac62cbb..c3dc241d6a 100644
--- a/streaming.c
+++ b/streaming.c
@@ -225,6 +225,7 @@ static int open_istream_loose(struct git_istream *st, struct repository *r,
{
struct object_info oi = OBJECT_INFO_INIT;
oi.sizep = &st->size;
+ oi.typep = type;
st->u.loose.mapped = map_loose_object(r, oid, &st->u.loose.mapsize);
if (!st->u.loose.mapped)
@@ -233,8 +234,10 @@ static int open_istream_loose(struct git_istream *st, struct repository *r,
st->u.loose.mapped,
st->u.loose.mapsize,
st->u.loose.hdr,
- sizeof(st->u.loose.hdr)) < 0) ||
- (parse_loose_header(st->u.loose.hdr, &oi, 0) < 0)) {
+ sizeof(st->u.loose.hdr),
+ NULL) < 0) ||
+ (parse_loose_header(st->u.loose.hdr, &oi) < 0) ||
+ *type < 0) {
git_inflate_end(&st->z);
munmap(st->u.loose.mapped, st->u.loose.mapsize);
return -1;
--
2.32.0.rc0.406.g73369325f8d
