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-rw-r--r--fsck.c817
1 files changed, 817 insertions, 0 deletions
diff --git a/fsck.c b/fsck.c
new file mode 100644
index 0000000000..e41e753d6d
--- /dev/null
+++ b/fsck.c
@@ -0,0 +1,817 @@
+#include "cache.h"
+#include "object.h"
+#include "blob.h"
+#include "tree.h"
+#include "tree-walk.h"
+#include "commit.h"
+#include "tag.h"
+#include "fsck.h"
+#include "refs.h"
+#include "utf8.h"
+#include "sha1-array.h"
+
+#define FSCK_FATAL -1
+#define FSCK_INFO -2
+
+#define FOREACH_MSG_ID(FUNC) \
+ /* fatal errors */ \
+ FUNC(NUL_IN_HEADER, FATAL) \
+ FUNC(UNTERMINATED_HEADER, FATAL) \
+ /* errors */ \
+ FUNC(BAD_DATE, ERROR) \
+ FUNC(BAD_DATE_OVERFLOW, ERROR) \
+ FUNC(BAD_EMAIL, ERROR) \
+ FUNC(BAD_NAME, ERROR) \
+ FUNC(BAD_OBJECT_SHA1, ERROR) \
+ FUNC(BAD_PARENT_SHA1, ERROR) \
+ FUNC(BAD_TAG_OBJECT, ERROR) \
+ FUNC(BAD_TIMEZONE, ERROR) \
+ FUNC(BAD_TREE, ERROR) \
+ FUNC(BAD_TREE_SHA1, ERROR) \
+ FUNC(BAD_TYPE, ERROR) \
+ FUNC(DUPLICATE_ENTRIES, ERROR) \
+ FUNC(MISSING_AUTHOR, ERROR) \
+ FUNC(MISSING_COMMITTER, ERROR) \
+ FUNC(MISSING_EMAIL, ERROR) \
+ FUNC(MISSING_GRAFT, ERROR) \
+ FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
+ FUNC(MISSING_OBJECT, ERROR) \
+ FUNC(MISSING_PARENT, ERROR) \
+ FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
+ FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
+ FUNC(MISSING_TAG, ERROR) \
+ FUNC(MISSING_TAG_ENTRY, ERROR) \
+ FUNC(MISSING_TAG_OBJECT, ERROR) \
+ FUNC(MISSING_TREE, ERROR) \
+ FUNC(MISSING_TYPE, ERROR) \
+ FUNC(MISSING_TYPE_ENTRY, ERROR) \
+ FUNC(MULTIPLE_AUTHORS, ERROR) \
+ FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
+ FUNC(TREE_NOT_SORTED, ERROR) \
+ FUNC(UNKNOWN_TYPE, ERROR) \
+ FUNC(ZERO_PADDED_DATE, ERROR) \
+ /* warnings */ \
+ FUNC(BAD_FILEMODE, WARN) \
+ FUNC(EMPTY_NAME, WARN) \
+ FUNC(FULL_PATHNAME, WARN) \
+ FUNC(HAS_DOT, WARN) \
+ FUNC(HAS_DOTDOT, WARN) \
+ FUNC(HAS_DOTGIT, WARN) \
+ FUNC(NULL_SHA1, WARN) \
+ FUNC(ZERO_PADDED_FILEMODE, WARN) \
+ /* infos (reported as warnings, but ignored by default) */ \
+ FUNC(BAD_TAG_NAME, INFO) \
+ FUNC(MISSING_TAGGER_ENTRY, INFO)
+
+#define MSG_ID(id, msg_type) FSCK_MSG_##id,
+enum fsck_msg_id {
+ FOREACH_MSG_ID(MSG_ID)
+ FSCK_MSG_MAX
+};
+#undef MSG_ID
+
+#define STR(x) #x
+#define MSG_ID(id, msg_type) { STR(id), NULL, FSCK_##msg_type },
+static struct {
+ const char *id_string;
+ const char *downcased;
+ int msg_type;
+} msg_id_info[FSCK_MSG_MAX + 1] = {
+ FOREACH_MSG_ID(MSG_ID)
+ { NULL, NULL, -1 }
+};
+#undef MSG_ID
+
+static int parse_msg_id(const char *text)
+{
+ int i;
+
+ if (!msg_id_info[0].downcased) {
+ /* convert id_string to lower case, without underscores. */
+ for (i = 0; i < FSCK_MSG_MAX; i++) {
+ const char *p = msg_id_info[i].id_string;
+ int len = strlen(p);
+ char *q = xmalloc(len);
+
+ msg_id_info[i].downcased = q;
+ while (*p)
+ if (*p == '_')
+ p++;
+ else
+ *(q)++ = tolower(*(p)++);
+ *q = '\0';
+ }
+ }
+
+ for (i = 0; i < FSCK_MSG_MAX; i++)
+ if (!strcmp(text, msg_id_info[i].downcased))
+ return i;
+
+ return -1;
+}
+
+static int fsck_msg_type(enum fsck_msg_id msg_id,
+ struct fsck_options *options)
+{
+ int msg_type;
+
+ assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
+
+ if (options->msg_type)
+ msg_type = options->msg_type[msg_id];
+ else {
+ msg_type = msg_id_info[msg_id].msg_type;
+ if (options->strict && msg_type == FSCK_WARN)
+ msg_type = FSCK_ERROR;
+ }
+
+ return msg_type;
+}
+
+static void init_skiplist(struct fsck_options *options, const char *path)
+{
+ static struct sha1_array skiplist = SHA1_ARRAY_INIT;
+ int sorted, fd;
+ char buffer[41];
+ unsigned char sha1[20];
+
+ if (options->skiplist)
+ sorted = options->skiplist->sorted;
+ else {
+ sorted = 1;
+ options->skiplist = &skiplist;
+ }
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ die("Could not open skip list: %s", path);
+ for (;;) {
+ int result = read_in_full(fd, buffer, sizeof(buffer));
+ if (result < 0)
+ die_errno("Could not read '%s'", path);
+ if (!result)
+ break;
+ if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n')
+ die("Invalid SHA-1: %s", buffer);
+ sha1_array_append(&skiplist, sha1);
+ if (sorted && skiplist.nr > 1 &&
+ hashcmp(skiplist.sha1[skiplist.nr - 2],
+ sha1) > 0)
+ sorted = 0;
+ }
+ close(fd);
+
+ if (sorted)
+ skiplist.sorted = 1;
+}
+
+static int parse_msg_type(const char *str)
+{
+ if (!strcmp(str, "error"))
+ return FSCK_ERROR;
+ else if (!strcmp(str, "warn"))
+ return FSCK_WARN;
+ else if (!strcmp(str, "ignore"))
+ return FSCK_IGNORE;
+ else
+ die("Unknown fsck message type: '%s'", str);
+}
+
+int is_valid_msg_type(const char *msg_id, const char *msg_type)
+{
+ if (parse_msg_id(msg_id) < 0)
+ return 0;
+ parse_msg_type(msg_type);
+ return 1;
+}
+
+void fsck_set_msg_type(struct fsck_options *options,
+ const char *msg_id, const char *msg_type)
+{
+ int id = parse_msg_id(msg_id), type;
+
+ if (id < 0)
+ die("Unhandled message id: %s", msg_id);
+ type = parse_msg_type(msg_type);
+
+ if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
+ die("Cannot demote %s to %s", msg_id, msg_type);
+
+ if (!options->msg_type) {
+ int i;
+ int *msg_type = xmalloc(sizeof(int) * FSCK_MSG_MAX);
+ for (i = 0; i < FSCK_MSG_MAX; i++)
+ msg_type[i] = fsck_msg_type(i, options);
+ options->msg_type = msg_type;
+ }
+
+ options->msg_type[id] = type;
+}
+
+void fsck_set_msg_types(struct fsck_options *options, const char *values)
+{
+ char *buf = xstrdup(values), *to_free = buf;
+ int done = 0;
+
+ while (!done) {
+ int len = strcspn(buf, " ,|"), equal;
+
+ done = !buf[len];
+ if (!len) {
+ buf++;
+ continue;
+ }
+ buf[len] = '\0';
+
+ for (equal = 0;
+ equal < len && buf[equal] != '=' && buf[equal] != ':';
+ equal++)
+ buf[equal] = tolower(buf[equal]);
+ buf[equal] = '\0';
+
+ if (!strcmp(buf, "skiplist")) {
+ if (equal == len)
+ die("skiplist requires a path");
+ init_skiplist(options, buf + equal + 1);
+ buf += len + 1;
+ continue;
+ }
+
+ if (equal == len)
+ die("Missing '=': '%s'", buf);
+
+ fsck_set_msg_type(options, buf, buf + equal + 1);
+ buf += len + 1;
+ }
+ free(to_free);
+}
+
+static void append_msg_id(struct strbuf *sb, const char *msg_id)
+{
+ for (;;) {
+ char c = *(msg_id)++;
+
+ if (!c)
+ break;
+ if (c != '_')
+ strbuf_addch(sb, tolower(c));
+ else {
+ assert(*msg_id);
+ strbuf_addch(sb, *(msg_id)++);
+ }
+ }
+
+ strbuf_addstr(sb, ": ");
+}
+
+__attribute__((format (printf, 4, 5)))
+static int report(struct fsck_options *options, struct object *object,
+ enum fsck_msg_id id, const char *fmt, ...)
+{
+ va_list ap;
+ struct strbuf sb = STRBUF_INIT;
+ int msg_type = fsck_msg_type(id, options), result;
+
+ if (msg_type == FSCK_IGNORE)
+ return 0;
+
+ if (options->skiplist && object &&
+ sha1_array_lookup(options->skiplist, object->sha1) >= 0)
+ return 0;
+
+ if (msg_type == FSCK_FATAL)
+ msg_type = FSCK_ERROR;
+ else if (msg_type == FSCK_INFO)
+ msg_type = FSCK_WARN;
+
+ append_msg_id(&sb, msg_id_info[id].id_string);
+
+ va_start(ap, fmt);
+ strbuf_vaddf(&sb, fmt, ap);
+ result = options->error_func(object, msg_type, sb.buf);
+ strbuf_release(&sb);
+ va_end(ap);
+
+ return result;
+}
+
+static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
+{
+ struct tree_desc desc;
+ struct name_entry entry;
+ int res = 0;
+
+ if (parse_tree(tree))
+ return -1;
+
+ init_tree_desc(&desc, tree->buffer, tree->size);
+ while (tree_entry(&desc, &entry)) {
+ int result;
+
+ if (S_ISGITLINK(entry.mode))
+ continue;
+ if (S_ISDIR(entry.mode))
+ result = options->walk(&lookup_tree(entry.sha1)->object, OBJ_TREE, data, options);
+ else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode))
+ result = options->walk(&lookup_blob(entry.sha1)->object, OBJ_BLOB, data, options);
+ else {
+ result = error("in tree %s: entry %s has bad mode %.6o",
+ sha1_to_hex(tree->object.sha1), entry.path, entry.mode);
+ }
+ if (result < 0)
+ return result;
+ if (!res)
+ res = result;
+ }
+ return res;
+}
+
+static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
+{
+ struct commit_list *parents;
+ int res;
+ int result;
+
+ if (parse_commit(commit))
+ return -1;
+
+ result = options->walk((struct object *)commit->tree, OBJ_TREE, data, options);
+ if (result < 0)
+ return result;
+ res = result;
+
+ parents = commit->parents;
+ while (parents) {
+ result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
+ if (result < 0)
+ return result;
+ if (!res)
+ res = result;
+ parents = parents->next;
+ }
+ return res;
+}
+
+static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
+{
+ if (parse_tag(tag))
+ return -1;
+ return options->walk(tag->tagged, OBJ_ANY, data, options);
+}
+
+int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
+{
+ if (!obj)
+ return -1;
+ switch (obj->type) {
+ case OBJ_BLOB:
+ return 0;
+ case OBJ_TREE:
+ return fsck_walk_tree((struct tree *)obj, data, options);
+ case OBJ_COMMIT:
+ return fsck_walk_commit((struct commit *)obj, data, options);
+ case OBJ_TAG:
+ return fsck_walk_tag((struct tag *)obj, data, options);
+ default:
+ error("Unknown object type for %s", sha1_to_hex(obj->sha1));
+ return -1;
+ }
+}
+
+/*
+ * The entries in a tree are ordered in the _path_ order,
+ * which means that a directory entry is ordered by adding
+ * a slash to the end of it.
+ *
+ * So a directory called "a" is ordered _after_ a file
+ * called "a.c", because "a/" sorts after "a.c".
+ */
+#define TREE_UNORDERED (-1)
+#define TREE_HAS_DUPS (-2)
+
+static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
+{
+ int len1 = strlen(name1);
+ int len2 = strlen(name2);
+ int len = len1 < len2 ? len1 : len2;
+ unsigned char c1, c2;
+ int cmp;
+
+ cmp = memcmp(name1, name2, len);
+ if (cmp < 0)
+ return 0;
+ if (cmp > 0)
+ return TREE_UNORDERED;
+
+ /*
+ * Ok, the first <len> characters are the same.
+ * Now we need to order the next one, but turn
+ * a '\0' into a '/' for a directory entry.
+ */
+ c1 = name1[len];
+ c2 = name2[len];
+ if (!c1 && !c2)
+ /*
+ * git-write-tree used to write out a nonsense tree that has
+ * entries with the same name, one blob and one tree. Make
+ * sure we do not have duplicate entries.
+ */
+ return TREE_HAS_DUPS;
+ if (!c1 && S_ISDIR(mode1))
+ c1 = '/';
+ if (!c2 && S_ISDIR(mode2))
+ c2 = '/';
+ return c1 < c2 ? 0 : TREE_UNORDERED;
+}
+
+static int fsck_tree(struct tree *item, struct fsck_options *options)
+{
+ int retval;
+ int has_null_sha1 = 0;
+ int has_full_path = 0;
+ int has_empty_name = 0;
+ int has_dot = 0;
+ int has_dotdot = 0;
+ int has_dotgit = 0;
+ int has_zero_pad = 0;
+ int has_bad_modes = 0;
+ int has_dup_entries = 0;
+ int not_properly_sorted = 0;
+ struct tree_desc desc;
+ unsigned o_mode;
+ const char *o_name;
+
+ init_tree_desc(&desc, item->buffer, item->size);
+
+ o_mode = 0;
+ o_name = NULL;
+
+ while (desc.size) {
+ unsigned mode;
+ const char *name;
+ const unsigned char *sha1;
+
+ sha1 = tree_entry_extract(&desc, &name, &mode);
+
+ has_null_sha1 |= is_null_sha1(sha1);
+ has_full_path |= !!strchr(name, '/');
+ has_empty_name |= !*name;
+ has_dot |= !strcmp(name, ".");
+ has_dotdot |= !strcmp(name, "..");
+ has_dotgit |= (!strcmp(name, ".git") ||
+ is_hfs_dotgit(name) ||
+ is_ntfs_dotgit(name));
+ has_zero_pad |= *(char *)desc.buffer == '0';
+ update_tree_entry(&desc);
+
+ switch (mode) {
+ /*
+ * Standard modes..
+ */
+ case S_IFREG | 0755:
+ case S_IFREG | 0644:
+ case S_IFLNK:
+ case S_IFDIR:
+ case S_IFGITLINK:
+ break;
+ /*
+ * This is nonstandard, but we had a few of these
+ * early on when we honored the full set of mode
+ * bits..
+ */
+ case S_IFREG | 0664:
+ if (!options->strict)
+ break;
+ default:
+ has_bad_modes = 1;
+ }
+
+ if (o_name) {
+ switch (verify_ordered(o_mode, o_name, mode, name)) {
+ case TREE_UNORDERED:
+ not_properly_sorted = 1;
+ break;
+ case TREE_HAS_DUPS:
+ has_dup_entries = 1;
+ break;
+ default:
+ break;
+ }
+ }
+
+ o_mode = mode;
+ o_name = name;
+ }
+
+ retval = 0;
+ if (has_null_sha1)
+ retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
+ if (has_full_path)
+ retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
+ if (has_empty_name)
+ retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
+ if (has_dot)
+ retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
+ if (has_dotdot)
+ retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
+ if (has_dotgit)
+ retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
+ if (has_zero_pad)
+ retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
+ if (has_bad_modes)
+ retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
+ if (has_dup_entries)
+ retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
+ if (not_properly_sorted)
+ retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
+ return retval;
+}
+
+static int verify_headers(const void *data, unsigned long size,
+ struct object *obj, struct fsck_options *options)
+{
+ const char *buffer = (const char *)data;
+ unsigned long i;
+
+ for (i = 0; i < size; i++) {
+ switch (buffer[i]) {
+ case '\0':
+ return report(options, obj,
+ FSCK_MSG_NUL_IN_HEADER,
+ "unterminated header: NUL at offset %ld", i);
+ case '\n':
+ if (i + 1 < size && buffer[i + 1] == '\n')
+ return 0;
+ }
+ }
+
+ /*
+ * We did not find double-LF that separates the header
+ * and the body. Not having a body is not a crime but
+ * we do want to see the terminating LF for the last header
+ * line.
+ */
+ if (size && buffer[size - 1] == '\n')
+ return 0;
+
+ return report(options, obj,
+ FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
+}
+
+static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
+{
+ const char *p = *ident;
+ char *end;
+
+ *ident = strchrnul(*ident, '\n');
+ if (**ident == '\n')
+ (*ident)++;
+
+ if (*p == '<')
+ return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
+ p += strcspn(p, "<>\n");
+ if (*p == '>')
+ return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
+ if (*p != '<')
+ return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
+ if (p[-1] != ' ')
+ return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
+ p++;
+ p += strcspn(p, "<>\n");
+ if (*p != '>')
+ return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
+ p++;
+ if (*p != ' ')
+ return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
+ p++;
+ if (*p == '0' && p[1] != ' ')
+ return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
+ if (date_overflows(strtoul(p, &end, 10)))
+ return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
+ if ((end == p || *end != ' '))
+ return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
+ p = end + 1;
+ if ((*p != '+' && *p != '-') ||
+ !isdigit(p[1]) ||
+ !isdigit(p[2]) ||
+ !isdigit(p[3]) ||
+ !isdigit(p[4]) ||
+ (p[5] != '\n'))
+ return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
+ p += 6;
+ return 0;
+}
+
+static int fsck_commit_buffer(struct commit *commit, const char *buffer,
+ unsigned long size, struct fsck_options *options)
+{
+ unsigned char tree_sha1[20], sha1[20];
+ struct commit_graft *graft;
+ unsigned parent_count, parent_line_count = 0, author_count;
+ int err;
+
+ if (verify_headers(buffer, size, &commit->object, options))
+ return -1;
+
+ if (!skip_prefix(buffer, "tree ", &buffer))
+ return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
+ if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n') {
+ err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
+ if (err)
+ return err;
+ }
+ buffer += 41;
+ while (skip_prefix(buffer, "parent ", &buffer)) {
+ if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
+ err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
+ if (err)
+ return err;
+ }
+ buffer += 41;
+ parent_line_count++;
+ }
+ graft = lookup_commit_graft(commit->object.sha1);
+ parent_count = commit_list_count(commit->parents);
+ if (graft) {
+ if (graft->nr_parent == -1 && !parent_count)
+ ; /* shallow commit */
+ else if (graft->nr_parent != parent_count) {
+ err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
+ if (err)
+ return err;
+ }
+ } else {
+ if (parent_count != parent_line_count) {
+ err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
+ if (err)
+ return err;
+ }
+ }
+ author_count = 0;
+ while (skip_prefix(buffer, "author ", &buffer)) {
+ author_count++;
+ err = fsck_ident(&buffer, &commit->object, options);
+ if (err)
+ return err;
+ }
+ if (author_count < 1)
+ err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
+ else if (author_count > 1)
+ err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
+ if (err)
+ return err;
+ if (!skip_prefix(buffer, "committer ", &buffer))
+ return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
+ err = fsck_ident(&buffer, &commit->object, options);
+ if (err)
+ return err;
+ if (!commit->tree)
+ return report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
+
+ return 0;
+}
+
+static int fsck_commit(struct commit *commit, const char *data,
+ unsigned long size, struct fsck_options *options)
+{
+ const char *buffer = data ? data : get_commit_buffer(commit, &size);
+ int ret = fsck_commit_buffer(commit, buffer, size, options);
+ if (!data)
+ unuse_commit_buffer(commit, buffer);
+ return ret;
+}
+
+static int fsck_tag_buffer(struct tag *tag, const char *data,
+ unsigned long size, struct fsck_options *options)
+{
+ unsigned char sha1[20];
+ int ret = 0;
+ const char *buffer;
+ char *to_free = NULL, *eol;
+ struct strbuf sb = STRBUF_INIT;
+
+ if (data)
+ buffer = data;
+ else {
+ enum object_type type;
+
+ buffer = to_free =
+ read_sha1_file(tag->object.sha1, &type, &size);
+ if (!buffer)
+ return report(options, &tag->object,
+ FSCK_MSG_MISSING_TAG_OBJECT,
+ "cannot read tag object");
+
+ if (type != OBJ_TAG) {
+ ret = report(options, &tag->object,
+ FSCK_MSG_TAG_OBJECT_NOT_TAG,
+ "expected tag got %s",
+ typename(type));
+ goto done;
+ }
+ }
+
+ if (verify_headers(buffer, size, &tag->object, options))
+ goto done;
+
+ if (!skip_prefix(buffer, "object ", &buffer)) {
+ ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
+ goto done;
+ }
+ if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
+ ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
+ if (ret)
+ goto done;
+ }
+ buffer += 41;
+
+ if (!skip_prefix(buffer, "type ", &buffer)) {
+ ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
+ goto done;
+ }
+ eol = strchr(buffer, '\n');
+ if (!eol) {
+ ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
+ goto done;
+ }
+ if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
+ ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
+ if (ret)
+ goto done;
+ buffer = eol + 1;
+
+ if (!skip_prefix(buffer, "tag ", &buffer)) {
+ ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
+ goto done;
+ }
+ eol = strchr(buffer, '\n');
+ if (!eol) {
+ ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
+ goto done;
+ }
+ strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
+ if (check_refname_format(sb.buf, 0)) {
+ ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
+ "invalid 'tag' name: %.*s",
+ (int)(eol - buffer), buffer);
+ if (ret)
+ goto done;
+ }
+ buffer = eol + 1;
+
+ if (!skip_prefix(buffer, "tagger ", &buffer)) {
+ /* early tags do not contain 'tagger' lines; warn only */
+ ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
+ if (ret)
+ goto done;
+ }
+ else
+ ret = fsck_ident(&buffer, &tag->object, options);
+
+done:
+ strbuf_release(&sb);
+ free(to_free);
+ return ret;
+}
+
+static int fsck_tag(struct tag *tag, const char *data,
+ unsigned long size, struct fsck_options *options)
+{
+ struct object *tagged = tag->tagged;
+
+ if (!tagged)
+ return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
+
+ return fsck_tag_buffer(tag, data, size, options);
+}
+
+int fsck_object(struct object *obj, void *data, unsigned long size,
+ struct fsck_options *options)
+{
+ if (!obj)
+ return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
+
+ if (obj->type == OBJ_BLOB)
+ return 0;
+ if (obj->type == OBJ_TREE)
+ return fsck_tree((struct tree *) obj, options);
+ if (obj->type == OBJ_COMMIT)
+ return fsck_commit((struct commit *) obj, (const char *) data,
+ size, options);
+ if (obj->type == OBJ_TAG)
+ return fsck_tag((struct tag *) obj, (const char *) data,
+ size, options);
+
+ return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
+ obj->type);
+}
+
+int fsck_error_function(struct object *obj, int msg_type, const char *message)
+{
+ if (msg_type == FSCK_WARN) {
+ warning("object %s: %s", sha1_to_hex(obj->sha1), message);
+ return 0;
+ }
+ error("object %s: %s", sha1_to_hex(obj->sha1), message);
+ return 1;
+}