diff options
Diffstat (limited to 'sha1_file.c')
| -rw-r--r-- | sha1_file.c | 191 |
1 files changed, 169 insertions, 22 deletions
diff --git a/sha1_file.c b/sha1_file.c index 1eb47f6113..ec957db5e1 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -284,7 +284,7 @@ static int link_alt_odb_entry(const char *entry, const char *relative_base, struct strbuf pathbuf = STRBUF_INIT; if (!is_absolute_path(entry) && relative_base) { - strbuf_addstr(&pathbuf, real_path(relative_base)); + strbuf_realpath(&pathbuf, relative_base, 1); strbuf_addch(&pathbuf, '/'); } strbuf_addstr(&pathbuf, entry); @@ -1630,39 +1630,54 @@ int git_open_cloexec(const char *name, int flags) return fd; } -static int stat_sha1_file(const unsigned char *sha1, struct stat *st) +/* + * Find "sha1" as a loose object in the local repository or in an alternate. + * Returns 0 on success, negative on failure. + * + * The "path" out-parameter will give the path of the object we found (if any). + * Note that it may point to static storage and is only valid until another + * call to sha1_file_name(), etc. + */ +static int stat_sha1_file(const unsigned char *sha1, struct stat *st, + const char **path) { struct alternate_object_database *alt; - if (!lstat(sha1_file_name(sha1), st)) + *path = sha1_file_name(sha1); + if (!lstat(*path, st)) return 0; prepare_alt_odb(); errno = ENOENT; for (alt = alt_odb_list; alt; alt = alt->next) { - const char *path = alt_sha1_path(alt, sha1); - if (!lstat(path, st)) + *path = alt_sha1_path(alt, sha1); + if (!lstat(*path, st)) return 0; } return -1; } -static int open_sha1_file(const unsigned char *sha1) +/* + * Like stat_sha1_file(), but actually open the object and return the + * descriptor. See the caveats on the "path" parameter above. + */ +static int open_sha1_file(const unsigned char *sha1, const char **path) { int fd; struct alternate_object_database *alt; int most_interesting_errno; - fd = git_open(sha1_file_name(sha1)); + *path = sha1_file_name(sha1); + fd = git_open(*path); if (fd >= 0) return fd; most_interesting_errno = errno; prepare_alt_odb(); for (alt = alt_odb_list; alt; alt = alt->next) { - const char *path = alt_sha1_path(alt, sha1); - fd = git_open(path); + *path = alt_sha1_path(alt, sha1); + fd = git_open(*path); if (fd >= 0) return fd; if (most_interesting_errno == ENOENT) @@ -1672,12 +1687,21 @@ static int open_sha1_file(const unsigned char *sha1) return -1; } -void *map_sha1_file(const unsigned char *sha1, unsigned long *size) +/* + * Map the loose object at "path" if it is not NULL, or the path found by + * searching for a loose object named "sha1". + */ +static void *map_sha1_file_1(const char *path, + const unsigned char *sha1, + unsigned long *size) { void *map; int fd; - fd = open_sha1_file(sha1); + if (path) + fd = git_open(path); + else + fd = open_sha1_file(sha1, &path); map = NULL; if (fd >= 0) { struct stat st; @@ -1686,7 +1710,7 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size) *size = xsize_t(st.st_size); if (!*size) { /* mmap() is forbidden on empty files */ - error("object file %s is empty", sha1_file_name(sha1)); + error("object file %s is empty", path); return NULL; } map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0); @@ -1696,6 +1720,11 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size) return map; } +void *map_sha1_file(const unsigned char *sha1, unsigned long *size) +{ + return map_sha1_file_1(NULL, sha1, size); +} + unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep) { @@ -2342,11 +2371,10 @@ static inline void release_delta_base_cache(struct delta_base_cache_entry *ent) void clear_delta_base_cache(void) { - struct hashmap_iter iter; - struct delta_base_cache_entry *entry; - for (entry = hashmap_iter_first(&delta_base_cache, &iter); - entry; - entry = hashmap_iter_next(&iter)) { + struct list_head *lru, *tmp; + list_for_each_safe(lru, tmp, &delta_base_cache_lru) { + struct delta_base_cache_entry *entry = + list_entry(lru, struct delta_base_cache_entry, lru); release_delta_base_cache(entry); } } @@ -2806,8 +2834,9 @@ static int sha1_loose_object_info(const unsigned char *sha1, * object even exists. */ if (!oi->typep && !oi->typename && !oi->sizep) { + const char *path; struct stat st; - if (stat_sha1_file(sha1, &st) < 0) + if (stat_sha1_file(sha1, &st, &path) < 0) return -1; if (oi->disk_sizep) *oi->disk_sizep = st.st_size; @@ -3003,6 +3032,8 @@ void *read_sha1_file_extended(const unsigned char *sha1, { void *data; const struct packed_git *p; + const char *path; + struct stat st; const unsigned char *repl = lookup_replace_object_extended(sha1, flag); errno = 0; @@ -3018,12 +3049,9 @@ void *read_sha1_file_extended(const unsigned char *sha1, die("replacement %s not found for %s", sha1_to_hex(repl), sha1_to_hex(sha1)); - if (has_loose_object(repl)) { - const char *path = sha1_file_name(sha1); - + if (!stat_sha1_file(repl, &st, &path)) die("loose object %s (stored in %s) is corrupt", sha1_to_hex(repl), path); - } if ((p = has_packed_and_bad(repl)) != NULL) die("packed object %s (stored in %s) is corrupt", @@ -3793,3 +3821,122 @@ int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags) } return r ? r : pack_errors; } + +static int check_stream_sha1(git_zstream *stream, + const char *hdr, + unsigned long size, + const char *path, + const unsigned char *expected_sha1) +{ + git_SHA_CTX c; + unsigned char real_sha1[GIT_SHA1_RAWSZ]; + unsigned char buf[4096]; + unsigned long total_read; + int status = Z_OK; + + git_SHA1_Init(&c); + git_SHA1_Update(&c, hdr, stream->total_out); + + /* + * We already read some bytes into hdr, but the ones up to the NUL + * do not count against the object's content size. + */ + total_read = stream->total_out - strlen(hdr) - 1; + + /* + * This size comparison must be "<=" to read the final zlib packets; + * see the comment in unpack_sha1_rest for details. + */ + while (total_read <= size && + (status == Z_OK || status == Z_BUF_ERROR)) { + stream->next_out = buf; + stream->avail_out = sizeof(buf); + if (size - total_read < stream->avail_out) + stream->avail_out = size - total_read; + status = git_inflate(stream, Z_FINISH); + git_SHA1_Update(&c, buf, stream->next_out - buf); + total_read += stream->next_out - buf; + } + git_inflate_end(stream); + + if (status != Z_STREAM_END) { + error("corrupt loose object '%s'", sha1_to_hex(expected_sha1)); + return -1; + } + if (stream->avail_in) { + error("garbage at end of loose object '%s'", + sha1_to_hex(expected_sha1)); + return -1; + } + + git_SHA1_Final(real_sha1, &c); + if (hashcmp(expected_sha1, real_sha1)) { + error("sha1 mismatch for %s (expected %s)", path, + sha1_to_hex(expected_sha1)); + return -1; + } + + return 0; +} + +int read_loose_object(const char *path, + const unsigned char *expected_sha1, + enum object_type *type, + unsigned long *size, + void **contents) +{ + int ret = -1; + int fd = -1; + void *map = NULL; + unsigned long mapsize; + git_zstream stream; + char hdr[32]; + + *contents = NULL; + + map = map_sha1_file_1(path, NULL, &mapsize); + if (!map) { + error_errno("unable to mmap %s", path); + goto out; + } + + if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) { + error("unable to unpack header of %s", path); + goto out; + } + + *type = parse_sha1_header(hdr, size); + if (*type < 0) { + error("unable to parse header of %s", path); + git_inflate_end(&stream); + goto out; + } + + if (*type == OBJ_BLOB) { + if (check_stream_sha1(&stream, hdr, *size, path, expected_sha1) < 0) + goto out; + } else { + *contents = unpack_sha1_rest(&stream, hdr, *size, expected_sha1); + if (!*contents) { + error("unable to unpack contents of %s", path); + git_inflate_end(&stream); + goto out; + } + if (check_sha1_signature(expected_sha1, *contents, + *size, typename(*type))) { + error("sha1 mismatch for %s (expected %s)", path, + sha1_to_hex(expected_sha1)); + free(*contents); + goto out; + } + } + + ret = 0; /* everything checks out */ + +out: + if (map) + munmap(map, mapsize); + if (fd >= 0) + close(fd); + return ret; +} |