This replaces the inflate validation with a CRC validation when reusing
data from a pack which uses index version 2. That makes repacking much
safer against corruptions, and it should be a bit faster too.
Signed-off-by: Nicolas Pitre <nico@xxxxxxx>
---
This completes the development for this patch series. I tested that
this works as expected by manually corrupting a pack, etc.
I intend to write real tests for this stuff of course, but at least the
way should be completely clear for the pack spliting series now.
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index 099dea0..533dd99 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -233,12 +233,6 @@ static struct revindex_entry * find_packed_object(struct packed_git *p,
die("internal error: pack revindex corrupt");
}
-static off_t find_packed_object_size(struct packed_git *p, off_t ofs)
-{
- struct revindex_entry *entry = find_packed_object(p, ofs);
- return entry[1].offset - ofs;
-}
-
static const unsigned char *find_packed_object_name(struct packed_git *p,
off_t ofs)
{
@@ -321,6 +315,28 @@ static int check_pack_inflate(struct packed_git *p,
stream.total_in == len) ? 0 : -1;
}
+static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
+ off_t offset, off_t len, unsigned int nr)
+{
+ const uint32_t *index_crc;
+ uint32_t data_crc = crc32(0, Z_NULL, 0);
+
+ do {
+ unsigned int avail;
+ void *data = use_pack(p, w_curs, offset, &avail);
+ if (avail > len)
+ avail = len;
+ data_crc = crc32(data_crc, data, avail);
+ offset += avail;
+ len -= avail;
+ } while (len);
+
+ index_crc = p->index_data;
+ index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
+
+ return data_crc != ntohl(*index_crc);
+}
+
static void copy_pack_data(struct sha1file *f,
struct packed_git *p,
struct pack_window **w_curs,
@@ -485,6 +501,7 @@ static unsigned long write_object(struct sha1file *f,
else {
struct packed_git *p = entry->in_pack;
struct pack_window *w_curs = NULL;
+ struct revindex_entry *revidx;
off_t offset;
if (entry->delta) {
@@ -507,12 +524,17 @@ static unsigned long write_object(struct sha1file *f,
hdrlen += 20;
}
- offset = entry->in_pack_offset + entry->in_pack_header_size;
- datalen = find_packed_object_size(p, entry->in_pack_offset)
- - entry->in_pack_header_size;
- if (!pack_to_stdout && check_pack_inflate(p, &w_curs,
- offset, datalen, entry->size))
- die("corrupt delta in pack %s", sha1_to_hex(entry->sha1));
+ offset = entry->in_pack_offset;
+ revidx = find_packed_object(p, offset);
+ datalen = revidx[1].offset - offset;
+ if (!pack_to_stdout && p->index_version > 1 &&
+ check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
+ die("bad packed object CRC for %s", sha1_to_hex(entry->sha1));
+ offset += entry->in_pack_header_size;
+ datalen -= entry->in_pack_header_size;
+ if (!pack_to_stdout && p->index_version == 1 &&
+ check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
+ die("corrupt packed object for %s", sha1_to_hex(entry->sha1));
copy_pack_data(f, p, &w_curs, offset, datalen);
unuse_pack(&w_curs);
reused++;
-
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