git/fsck.c
Elijah Newren d812c3b6a0 treewide: remove cache.h inclusion due to object.h changes
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11 08:52:10 -07:00

1415 lines
37 KiB
C

#include "git-compat-util.h"
#include "alloc.h"
#include "hex.h"
#include "object-store.h"
#include "repository.h"
#include "object.h"
#include "attr.h"
#include "blob.h"
#include "tree.h"
#include "tree-walk.h"
#include "commit.h"
#include "tag.h"
#include "fsck.h"
#include "refs.h"
#include "url.h"
#include "utf8.h"
#include "decorate.h"
#include "oidset.h"
#include "packfile.h"
#include "submodule-config.h"
#include "config.h"
#include "credential.h"
#include "help.h"
#define STR(x) #x
#define MSG_ID(id, msg_type) { STR(id), NULL, NULL, FSCK_##msg_type },
static struct {
const char *id_string;
const char *downcased;
const char *camelcased;
enum fsck_msg_type msg_type;
} msg_id_info[FSCK_MSG_MAX + 1] = {
FOREACH_FSCK_MSG_ID(MSG_ID)
{ NULL, NULL, NULL, -1 }
};
#undef MSG_ID
#undef STR
static void prepare_msg_ids(void)
{
int i;
if (msg_id_info[0].downcased)
return;
/* 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';
p = msg_id_info[i].id_string;
q = xmalloc(len);
msg_id_info[i].camelcased = q;
while (*p) {
if (*p == '_') {
p++;
if (*p)
*q++ = *p++;
} else {
*q++ = tolower(*p++);
}
}
*q = '\0';
}
}
static int parse_msg_id(const char *text)
{
int i;
prepare_msg_ids();
for (i = 0; i < FSCK_MSG_MAX; i++)
if (!strcmp(text, msg_id_info[i].downcased))
return i;
return -1;
}
void list_config_fsck_msg_ids(struct string_list *list, const char *prefix)
{
int i;
prepare_msg_ids();
for (i = 0; i < FSCK_MSG_MAX; i++)
list_config_item(list, prefix, msg_id_info[i].camelcased);
}
static enum fsck_msg_type fsck_msg_type(enum fsck_msg_id msg_id,
struct fsck_options *options)
{
assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
if (!options->msg_type) {
enum fsck_msg_type msg_type = msg_id_info[msg_id].msg_type;
if (options->strict && msg_type == FSCK_WARN)
msg_type = FSCK_ERROR;
return msg_type;
}
return options->msg_type[msg_id];
}
static enum fsck_msg_type 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_from_ids(struct fsck_options *options,
enum fsck_msg_id msg_id,
enum fsck_msg_type msg_type)
{
if (!options->msg_type) {
int i;
enum fsck_msg_type *severity;
ALLOC_ARRAY(severity, FSCK_MSG_MAX);
for (i = 0; i < FSCK_MSG_MAX; i++)
severity[i] = fsck_msg_type(i, options);
options->msg_type = severity;
}
options->msg_type[msg_id] = msg_type;
}
void fsck_set_msg_type(struct fsck_options *options,
const char *msg_id_str, const char *msg_type_str)
{
int msg_id = parse_msg_id(msg_id_str);
enum fsck_msg_type msg_type = parse_msg_type(msg_type_str);
if (msg_id < 0)
die("Unhandled message id: %s", msg_id_str);
if (msg_type != FSCK_ERROR && msg_id_info[msg_id].msg_type == FSCK_FATAL)
die("Cannot demote %s to %s", msg_id_str, msg_type_str);
fsck_set_msg_type_from_ids(options, msg_id, msg_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");
oidset_parse_file(&options->skiplist, 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 int object_on_skiplist(struct fsck_options *opts,
const struct object_id *oid)
{
return opts && oid && oidset_contains(&opts->skiplist, oid);
}
__attribute__((format (printf, 5, 6)))
static int report(struct fsck_options *options,
const struct object_id *oid, enum object_type object_type,
enum fsck_msg_id msg_id, const char *fmt, ...)
{
va_list ap;
struct strbuf sb = STRBUF_INIT;
enum fsck_msg_type msg_type = fsck_msg_type(msg_id, options);
int result;
if (msg_type == FSCK_IGNORE)
return 0;
if (object_on_skiplist(options, oid))
return 0;
if (msg_type == FSCK_FATAL)
msg_type = FSCK_ERROR;
else if (msg_type == FSCK_INFO)
msg_type = FSCK_WARN;
prepare_msg_ids();
strbuf_addf(&sb, "%s: ", msg_id_info[msg_id].camelcased);
va_start(ap, fmt);
strbuf_vaddf(&sb, fmt, ap);
result = options->error_func(options, oid, object_type,
msg_type, msg_id, sb.buf);
strbuf_release(&sb);
va_end(ap);
return result;
}
void fsck_enable_object_names(struct fsck_options *options)
{
if (!options->object_names)
options->object_names = kh_init_oid_map();
}
const char *fsck_get_object_name(struct fsck_options *options,
const struct object_id *oid)
{
khiter_t pos;
if (!options->object_names)
return NULL;
pos = kh_get_oid_map(options->object_names, *oid);
if (pos >= kh_end(options->object_names))
return NULL;
return kh_value(options->object_names, pos);
}
void fsck_put_object_name(struct fsck_options *options,
const struct object_id *oid,
const char *fmt, ...)
{
va_list ap;
struct strbuf buf = STRBUF_INIT;
khiter_t pos;
int hashret;
if (!options->object_names)
return;
pos = kh_put_oid_map(options->object_names, *oid, &hashret);
if (!hashret)
return;
va_start(ap, fmt);
strbuf_vaddf(&buf, fmt, ap);
kh_value(options->object_names, pos) = strbuf_detach(&buf, NULL);
va_end(ap);
}
const char *fsck_describe_object(struct fsck_options *options,
const struct object_id *oid)
{
static struct strbuf bufs[] = {
STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
};
static int b = 0;
struct strbuf *buf;
const char *name = fsck_get_object_name(options, oid);
buf = bufs + b;
b = (b + 1) % ARRAY_SIZE(bufs);
strbuf_reset(buf);
strbuf_addstr(buf, oid_to_hex(oid));
if (name)
strbuf_addf(buf, " (%s)", name);
return buf->buf;
}
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;
const char *name;
if (parse_tree(tree))
return -1;
name = fsck_get_object_name(options, &tree->object.oid);
if (init_tree_desc_gently(&desc, tree->buffer, tree->size, 0))
return -1;
while (tree_entry_gently(&desc, &entry)) {
struct object *obj;
int result;
if (S_ISGITLINK(entry.mode))
continue;
if (S_ISDIR(entry.mode)) {
obj = (struct object *)lookup_tree(the_repository, &entry.oid);
if (name && obj)
fsck_put_object_name(options, &entry.oid, "%s%s/",
name, entry.path);
result = options->walk(obj, OBJ_TREE, data, options);
}
else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
obj = (struct object *)lookup_blob(the_repository, &entry.oid);
if (name && obj)
fsck_put_object_name(options, &entry.oid, "%s%s",
name, entry.path);
result = options->walk(obj, OBJ_BLOB, data, options);
}
else {
result = error("in tree %s: entry %s has bad mode %.6o",
fsck_describe_object(options, &tree->object.oid),
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)
{
int counter = 0, generation = 0, name_prefix_len = 0;
struct commit_list *parents;
int res;
int result;
const char *name;
if (repo_parse_commit(the_repository, commit))
return -1;
name = fsck_get_object_name(options, &commit->object.oid);
if (name)
fsck_put_object_name(options, get_commit_tree_oid(commit),
"%s:", name);
result = options->walk((struct object *) repo_get_commit_tree(the_repository, commit),
OBJ_TREE, data, options);
if (result < 0)
return result;
res = result;
parents = commit->parents;
if (name && parents) {
int len = strlen(name), power;
if (len && name[len - 1] == '^') {
generation = 1;
name_prefix_len = len - 1;
}
else { /* parse ~<generation> suffix */
for (generation = 0, power = 1;
len && isdigit(name[len - 1]);
power *= 10)
generation += power * (name[--len] - '0');
if (power > 1 && len && name[len - 1] == '~')
name_prefix_len = len - 1;
else {
/* Maybe a non-first parent, e.g. HEAD^2 */
generation = 0;
name_prefix_len = len;
}
}
}
while (parents) {
if (name) {
struct object_id *oid = &parents->item->object.oid;
if (counter++)
fsck_put_object_name(options, oid, "%s^%d",
name, counter);
else if (generation > 0)
fsck_put_object_name(options, oid, "%.*s~%d",
name_prefix_len, name,
generation + 1);
else
fsck_put_object_name(options, oid, "%s^", name);
}
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)
{
const char *name = fsck_get_object_name(options, &tag->object.oid);
if (parse_tag(tag))
return -1;
if (name)
fsck_put_object_name(options, &tag->tagged->oid, "%s", name);
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;
if (obj->type == OBJ_NONE)
parse_object(the_repository, &obj->oid);
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",
fsck_describe_object(options, &obj->oid));
return -1;
}
}
struct name_stack {
const char **names;
size_t nr, alloc;
};
static void name_stack_push(struct name_stack *stack, const char *name)
{
ALLOC_GROW(stack->names, stack->nr + 1, stack->alloc);
stack->names[stack->nr++] = name;
}
static const char *name_stack_pop(struct name_stack *stack)
{
return stack->nr ? stack->names[--stack->nr] : NULL;
}
static void name_stack_clear(struct name_stack *stack)
{
FREE_AND_NULL(stack->names);
stack->nr = stack->alloc = 0;
}
/*
* 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 is_less_than_slash(unsigned char c)
{
return '\0' < c && c < '/';
}
static int verify_ordered(unsigned mode1, const char *name1,
unsigned mode2, const char *name2,
struct name_stack *candidates)
{
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 = '/';
/*
* There can be non-consecutive duplicates due to the implicitly
* added slash, e.g.:
*
* foo
* foo.bar
* foo.bar.baz
* foo.bar/
* foo/
*
* Record non-directory candidates (like "foo" and "foo.bar" in
* the example) on a stack and check directory candidates (like
* foo/" and "foo.bar/") against that stack.
*/
if (!c1 && is_less_than_slash(c2)) {
name_stack_push(candidates, name1);
} else if (c2 == '/' && is_less_than_slash(c1)) {
for (;;) {
const char *p;
const char *f_name = name_stack_pop(candidates);
if (!f_name)
break;
if (!skip_prefix(name2, f_name, &p))
continue;
if (!*p)
return TREE_HAS_DUPS;
if (is_less_than_slash(*p)) {
name_stack_push(candidates, f_name);
break;
}
}
}
return c1 < c2 ? 0 : TREE_UNORDERED;
}
static int fsck_tree(const struct object_id *tree_oid,
const char *buffer, unsigned long size,
struct fsck_options *options)
{
int retval = 0;
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;
struct name_stack df_dup_candidates = { NULL };
if (init_tree_desc_gently(&desc, buffer, size, TREE_DESC_RAW_MODES)) {
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_BAD_TREE,
"cannot be parsed as a tree");
return retval;
}
o_mode = 0;
o_name = NULL;
while (desc.size) {
unsigned short mode;
const char *name, *backslash;
const struct object_id *entry_oid;
entry_oid = tree_entry_extract(&desc, &name, &mode);
has_null_sha1 |= is_null_oid(entry_oid);
has_full_path |= !!strchr(name, '/');
has_empty_name |= !*name;
has_dot |= !strcmp(name, ".");
has_dotdot |= !strcmp(name, "..");
has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
has_zero_pad |= *(char *)desc.buffer == '0';
if (is_hfs_dotgitmodules(name) || is_ntfs_dotgitmodules(name)) {
if (!S_ISLNK(mode))
oidset_insert(&options->gitmodules_found,
entry_oid);
else
retval += report(options,
tree_oid, OBJ_TREE,
FSCK_MSG_GITMODULES_SYMLINK,
".gitmodules is a symbolic link");
}
if (is_hfs_dotgitattributes(name) || is_ntfs_dotgitattributes(name)) {
if (!S_ISLNK(mode))
oidset_insert(&options->gitattributes_found,
entry_oid);
else
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_GITATTRIBUTES_SYMLINK,
".gitattributes is a symlink");
}
if (S_ISLNK(mode)) {
if (is_hfs_dotgitignore(name) ||
is_ntfs_dotgitignore(name))
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_GITIGNORE_SYMLINK,
".gitignore is a symlink");
if (is_hfs_dotmailmap(name) ||
is_ntfs_dotmailmap(name))
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_MAILMAP_SYMLINK,
".mailmap is a symlink");
}
if ((backslash = strchr(name, '\\'))) {
while (backslash) {
backslash++;
has_dotgit |= is_ntfs_dotgit(backslash);
if (is_ntfs_dotgitmodules(backslash)) {
if (!S_ISLNK(mode))
oidset_insert(&options->gitmodules_found,
entry_oid);
else
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_GITMODULES_SYMLINK,
".gitmodules is a symbolic link");
}
backslash = strchr(backslash, '\\');
}
}
if (update_tree_entry_gently(&desc)) {
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_BAD_TREE,
"cannot be parsed as a tree");
break;
}
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;
/* fallthrough */
default:
has_bad_modes = 1;
}
if (o_name) {
switch (verify_ordered(o_mode, o_name, mode, name,
&df_dup_candidates)) {
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;
}
name_stack_clear(&df_dup_candidates);
if (has_null_sha1)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_NULL_SHA1,
"contains entries pointing to null sha1");
if (has_full_path)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_FULL_PATHNAME,
"contains full pathnames");
if (has_empty_name)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_EMPTY_NAME,
"contains empty pathname");
if (has_dot)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_HAS_DOT,
"contains '.'");
if (has_dotdot)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_HAS_DOTDOT,
"contains '..'");
if (has_dotgit)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_HAS_DOTGIT,
"contains '.git'");
if (has_zero_pad)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_ZERO_PADDED_FILEMODE,
"contains zero-padded file modes");
if (has_bad_modes)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_BAD_FILEMODE,
"contains bad file modes");
if (has_dup_entries)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_DUPLICATE_ENTRIES,
"contains duplicate file entries");
if (not_properly_sorted)
retval += report(options, tree_oid, OBJ_TREE,
FSCK_MSG_TREE_NOT_SORTED,
"not properly sorted");
return retval;
}
/*
* Confirm that the headers of a commit or tag object end in a reasonable way,
* either with the usual "\n\n" separator, or at least with a trailing newline
* on the final header line.
*
* This property is important for the memory safety of our callers. It allows
* them to scan the buffer linewise without constantly checking the remaining
* size as long as:
*
* - they check that there are bytes left in the buffer at the start of any
* line (i.e., that the last newline they saw was not the final one we
* found here)
*
* - any intra-line scanning they do will stop at a newline, which will worst
* case hit the newline we found here as the end-of-header. This makes it
* OK for them to use helpers like parse_oid_hex(), or even skip_prefix().
*/
static int verify_headers(const void *data, unsigned long size,
const struct object_id *oid, enum object_type type,
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, oid, type,
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, oid, type,
FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
}
static int fsck_ident(const char **ident,
const struct object_id *oid, enum object_type type,
struct fsck_options *options)
{
const char *p = *ident;
char *end;
*ident = strchrnul(*ident, '\n');
if (**ident == '\n')
(*ident)++;
if (*p == '<')
return report(options, oid, type, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
p += strcspn(p, "<>\n");
if (*p == '>')
return report(options, oid, type, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
if (*p != '<')
return report(options, oid, type, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
if (p[-1] != ' ')
return report(options, oid, type, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
p++;
p += strcspn(p, "<>\n");
if (*p != '>')
return report(options, oid, type, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
p++;
if (*p != ' ')
return report(options, oid, type, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
p++;
/*
* Our timestamp parser is based on the C strto*() functions, which
* will happily eat whitespace, including the newline that is supposed
* to prevent us walking past the end of the buffer. So do our own
* scan, skipping linear whitespace but not newlines, and then
* confirming we found a digit. We _could_ be even more strict here,
* as we really expect only a single space, but since we have
* traditionally allowed extra whitespace, we'll continue to do so.
*/
while (*p == ' ' || *p == '\t')
p++;
if (!isdigit(*p))
return report(options, oid, type, FSCK_MSG_BAD_DATE,
"invalid author/committer line - bad date");
if (*p == '0' && p[1] != ' ')
return report(options, oid, type, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
if (date_overflows(parse_timestamp(p, &end, 10)))
return report(options, oid, type, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
if ((end == p || *end != ' '))
return report(options, oid, type, 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, oid, type, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
p += 6;
return 0;
}
static int fsck_commit(const struct object_id *oid,
const char *buffer, unsigned long size,
struct fsck_options *options)
{
struct object_id tree_oid, parent_oid;
unsigned author_count;
int err;
const char *buffer_begin = buffer;
const char *buffer_end = buffer + size;
const char *p;
/*
* We _must_ stop parsing immediately if this reports failure, as the
* memory safety of the rest of the function depends on it. See the
* comment above the definition of verify_headers() for more details.
*/
if (verify_headers(buffer, size, oid, OBJ_COMMIT, options))
return -1;
if (buffer >= buffer_end || !skip_prefix(buffer, "tree ", &buffer))
return report(options, oid, OBJ_COMMIT, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
if (parse_oid_hex(buffer, &tree_oid, &p) || *p != '\n') {
err = report(options, oid, OBJ_COMMIT, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
if (err)
return err;
}
buffer = p + 1;
while (buffer < buffer_end && skip_prefix(buffer, "parent ", &buffer)) {
if (parse_oid_hex(buffer, &parent_oid, &p) || *p != '\n') {
err = report(options, oid, OBJ_COMMIT, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
if (err)
return err;
}
buffer = p + 1;
}
author_count = 0;
while (buffer < buffer_end && skip_prefix(buffer, "author ", &buffer)) {
author_count++;
err = fsck_ident(&buffer, oid, OBJ_COMMIT, options);
if (err)
return err;
}
if (author_count < 1)
err = report(options, oid, OBJ_COMMIT, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
else if (author_count > 1)
err = report(options, oid, OBJ_COMMIT, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
if (err)
return err;
if (buffer >= buffer_end || !skip_prefix(buffer, "committer ", &buffer))
return report(options, oid, OBJ_COMMIT, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
err = fsck_ident(&buffer, oid, OBJ_COMMIT, options);
if (err)
return err;
if (memchr(buffer_begin, '\0', size)) {
err = report(options, oid, OBJ_COMMIT, FSCK_MSG_NUL_IN_COMMIT,
"NUL byte in the commit object body");
if (err)
return err;
}
return 0;
}
static int fsck_tag(const struct object_id *oid, const char *buffer,
unsigned long size, struct fsck_options *options)
{
struct object_id tagged_oid;
int tagged_type;
return fsck_tag_standalone(oid, buffer, size, options, &tagged_oid,
&tagged_type);
}
int fsck_tag_standalone(const struct object_id *oid, const char *buffer,
unsigned long size, struct fsck_options *options,
struct object_id *tagged_oid,
int *tagged_type)
{
int ret = 0;
char *eol;
struct strbuf sb = STRBUF_INIT;
const char *buffer_end = buffer + size;
const char *p;
/*
* We _must_ stop parsing immediately if this reports failure, as the
* memory safety of the rest of the function depends on it. See the
* comment above the definition of verify_headers() for more details.
*/
ret = verify_headers(buffer, size, oid, OBJ_TAG, options);
if (ret)
goto done;
if (buffer >= buffer_end || !skip_prefix(buffer, "object ", &buffer)) {
ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
goto done;
}
if (parse_oid_hex(buffer, tagged_oid, &p) || *p != '\n') {
ret = report(options, oid, OBJ_TAG, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
if (ret)
goto done;
}
buffer = p + 1;
if (buffer >= buffer_end || !skip_prefix(buffer, "type ", &buffer)) {
ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
goto done;
}
eol = memchr(buffer, '\n', buffer_end - buffer);
if (!eol) {
ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
goto done;
}
*tagged_type = type_from_string_gently(buffer, eol - buffer, 1);
if (*tagged_type < 0)
ret = report(options, oid, OBJ_TAG, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
if (ret)
goto done;
buffer = eol + 1;
if (buffer >= buffer_end || !skip_prefix(buffer, "tag ", &buffer)) {
ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
goto done;
}
eol = memchr(buffer, '\n', buffer_end - buffer);
if (!eol) {
ret = report(options, oid, OBJ_TAG, 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, oid, OBJ_TAG,
FSCK_MSG_BAD_TAG_NAME,
"invalid 'tag' name: %.*s",
(int)(eol - buffer), buffer);
if (ret)
goto done;
}
buffer = eol + 1;
if (buffer >= buffer_end || !skip_prefix(buffer, "tagger ", &buffer)) {
/* early tags do not contain 'tagger' lines; warn only */
ret = report(options, oid, OBJ_TAG, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
if (ret)
goto done;
}
else
ret = fsck_ident(&buffer, oid, OBJ_TAG, options);
if (buffer < buffer_end && !starts_with(buffer, "\n")) {
/*
* The verify_headers() check will allow
* e.g. "[...]tagger <tagger>\nsome
* garbage\n\nmessage" to pass, thinking "some
* garbage" could be a custom header. E.g. "mktag"
* doesn't want any unknown headers.
*/
ret = report(options, oid, OBJ_TAG, FSCK_MSG_EXTRA_HEADER_ENTRY, "invalid format - extra header(s) after 'tagger'");
if (ret)
goto done;
}
done:
strbuf_release(&sb);
return ret;
}
static int starts_with_dot_slash(const char *const path)
{
return path_match_flags(path, PATH_MATCH_STARTS_WITH_DOT_SLASH |
PATH_MATCH_XPLATFORM);
}
static int starts_with_dot_dot_slash(const char *const path)
{
return path_match_flags(path, PATH_MATCH_STARTS_WITH_DOT_DOT_SLASH |
PATH_MATCH_XPLATFORM);
}
static int submodule_url_is_relative(const char *url)
{
return starts_with_dot_slash(url) || starts_with_dot_dot_slash(url);
}
/*
* Count directory components that a relative submodule URL should chop
* from the remote_url it is to be resolved against.
*
* In other words, this counts "../" components at the start of a
* submodule URL.
*
* Returns the number of directory components to chop and writes a
* pointer to the next character of url after all leading "./" and
* "../" components to out.
*/
static int count_leading_dotdots(const char *url, const char **out)
{
int result = 0;
while (1) {
if (starts_with_dot_dot_slash(url)) {
result++;
url += strlen("../");
continue;
}
if (starts_with_dot_slash(url)) {
url += strlen("./");
continue;
}
*out = url;
return result;
}
}
/*
* Check whether a transport is implemented by git-remote-curl.
*
* If it is, returns 1 and writes the URL that would be passed to
* git-remote-curl to the "out" parameter.
*
* Otherwise, returns 0 and leaves "out" untouched.
*
* Examples:
* http::https://example.com/repo.git -> 1, https://example.com/repo.git
* https://example.com/repo.git -> 1, https://example.com/repo.git
* git://example.com/repo.git -> 0
*
* This is for use in checking for previously exploitable bugs that
* required a submodule URL to be passed to git-remote-curl.
*/
static int url_to_curl_url(const char *url, const char **out)
{
/*
* We don't need to check for case-aliases, "http.exe", and so
* on because in the default configuration, is_transport_allowed
* prevents URLs with those schemes from being cloned
* automatically.
*/
if (skip_prefix(url, "http::", out) ||
skip_prefix(url, "https::", out) ||
skip_prefix(url, "ftp::", out) ||
skip_prefix(url, "ftps::", out))
return 1;
if (starts_with(url, "http://") ||
starts_with(url, "https://") ||
starts_with(url, "ftp://") ||
starts_with(url, "ftps://")) {
*out = url;
return 1;
}
return 0;
}
static int check_submodule_url(const char *url)
{
const char *curl_url;
if (looks_like_command_line_option(url))
return -1;
if (submodule_url_is_relative(url) || starts_with(url, "git://")) {
char *decoded;
const char *next;
int has_nl;
/*
* This could be appended to an http URL and url-decoded;
* check for malicious characters.
*/
decoded = url_decode(url);
has_nl = !!strchr(decoded, '\n');
free(decoded);
if (has_nl)
return -1;
/*
* URLs which escape their root via "../" can overwrite
* the host field and previous components, resolving to
* URLs like https::example.com/submodule.git and
* https:///example.com/submodule.git that were
* susceptible to CVE-2020-11008.
*/
if (count_leading_dotdots(url, &next) > 0 &&
(*next == ':' || *next == '/'))
return -1;
}
else if (url_to_curl_url(url, &curl_url)) {
struct credential c = CREDENTIAL_INIT;
int ret = 0;
if (credential_from_url_gently(&c, curl_url, 1) ||
!*c.host)
ret = -1;
credential_clear(&c);
return ret;
}
return 0;
}
struct fsck_gitmodules_data {
const struct object_id *oid;
struct fsck_options *options;
int ret;
};
static int fsck_gitmodules_fn(const char *var, const char *value, void *vdata)
{
struct fsck_gitmodules_data *data = vdata;
const char *subsection, *key;
size_t subsection_len;
char *name;
if (parse_config_key(var, "submodule", &subsection, &subsection_len, &key) < 0 ||
!subsection)
return 0;
name = xmemdupz(subsection, subsection_len);
if (check_submodule_name(name) < 0)
data->ret |= report(data->options,
data->oid, OBJ_BLOB,
FSCK_MSG_GITMODULES_NAME,
"disallowed submodule name: %s",
name);
if (!strcmp(key, "url") && value &&
check_submodule_url(value) < 0)
data->ret |= report(data->options,
data->oid, OBJ_BLOB,
FSCK_MSG_GITMODULES_URL,
"disallowed submodule url: %s",
value);
if (!strcmp(key, "path") && value &&
looks_like_command_line_option(value))
data->ret |= report(data->options,
data->oid, OBJ_BLOB,
FSCK_MSG_GITMODULES_PATH,
"disallowed submodule path: %s",
value);
if (!strcmp(key, "update") && value &&
parse_submodule_update_type(value) == SM_UPDATE_COMMAND)
data->ret |= report(data->options, data->oid, OBJ_BLOB,
FSCK_MSG_GITMODULES_UPDATE,
"disallowed submodule update setting: %s",
value);
free(name);
return 0;
}
static int fsck_blob(const struct object_id *oid, const char *buf,
unsigned long size, struct fsck_options *options)
{
int ret = 0;
if (object_on_skiplist(options, oid))
return 0;
if (oidset_contains(&options->gitmodules_found, oid)) {
struct config_options config_opts = { 0 };
struct fsck_gitmodules_data data;
oidset_insert(&options->gitmodules_done, oid);
if (!buf) {
/*
* A missing buffer here is a sign that the caller found the
* blob too gigantic to load into memory. Let's just consider
* that an error.
*/
return report(options, oid, OBJ_BLOB,
FSCK_MSG_GITMODULES_LARGE,
".gitmodules too large to parse");
}
data.oid = oid;
data.options = options;
data.ret = 0;
config_opts.error_action = CONFIG_ERROR_SILENT;
if (git_config_from_mem(fsck_gitmodules_fn, CONFIG_ORIGIN_BLOB,
".gitmodules", buf, size, &data, &config_opts))
data.ret |= report(options, oid, OBJ_BLOB,
FSCK_MSG_GITMODULES_PARSE,
"could not parse gitmodules blob");
ret |= data.ret;
}
if (oidset_contains(&options->gitattributes_found, oid)) {
const char *ptr;
oidset_insert(&options->gitattributes_done, oid);
if (!buf || size > ATTR_MAX_FILE_SIZE) {
/*
* A missing buffer here is a sign that the caller found the
* blob too gigantic to load into memory. Let's just consider
* that an error.
*/
return report(options, oid, OBJ_BLOB,
FSCK_MSG_GITATTRIBUTES_LARGE,
".gitattributes too large to parse");
}
for (ptr = buf; *ptr; ) {
const char *eol = strchrnul(ptr, '\n');
if (eol - ptr >= ATTR_MAX_LINE_LENGTH) {
ret |= report(options, oid, OBJ_BLOB,
FSCK_MSG_GITATTRIBUTES_LINE_LENGTH,
".gitattributes has too long lines to parse");
break;
}
ptr = *eol ? eol + 1 : eol;
}
}
return ret;
}
int fsck_object(struct object *obj, void *data, unsigned long size,
struct fsck_options *options)
{
if (!obj)
return report(options, NULL, OBJ_NONE, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
return fsck_buffer(&obj->oid, obj->type, data, size, options);
}
int fsck_buffer(const struct object_id *oid, enum object_type type,
void *data, unsigned long size,
struct fsck_options *options)
{
if (type == OBJ_BLOB)
return fsck_blob(oid, data, size, options);
if (type == OBJ_TREE)
return fsck_tree(oid, data, size, options);
if (type == OBJ_COMMIT)
return fsck_commit(oid, data, size, options);
if (type == OBJ_TAG)
return fsck_tag(oid, data, size, options);
return report(options, oid, type,
FSCK_MSG_UNKNOWN_TYPE,
"unknown type '%d' (internal fsck error)",
type);
}
int fsck_error_function(struct fsck_options *o,
const struct object_id *oid,
enum object_type object_type,
enum fsck_msg_type msg_type,
enum fsck_msg_id msg_id,
const char *message)
{
if (msg_type == FSCK_WARN) {
warning("object %s: %s", fsck_describe_object(o, oid), message);
return 0;
}
error("object %s: %s", fsck_describe_object(o, oid), message);
return 1;
}
static int fsck_blobs(struct oidset *blobs_found, struct oidset *blobs_done,
enum fsck_msg_id msg_missing, enum fsck_msg_id msg_type,
struct fsck_options *options, const char *blob_type)
{
int ret = 0;
struct oidset_iter iter;
const struct object_id *oid;
oidset_iter_init(blobs_found, &iter);
while ((oid = oidset_iter_next(&iter))) {
enum object_type type;
unsigned long size;
char *buf;
if (oidset_contains(blobs_done, oid))
continue;
buf = repo_read_object_file(the_repository, oid, &type, &size);
if (!buf) {
if (is_promisor_object(oid))
continue;
ret |= report(options,
oid, OBJ_BLOB, msg_missing,
"unable to read %s blob", blob_type);
continue;
}
if (type == OBJ_BLOB)
ret |= fsck_blob(oid, buf, size, options);
else
ret |= report(options, oid, type, msg_type,
"non-blob found at %s", blob_type);
free(buf);
}
oidset_clear(blobs_found);
oidset_clear(blobs_done);
return ret;
}
int fsck_finish(struct fsck_options *options)
{
int ret = 0;
ret |= fsck_blobs(&options->gitmodules_found, &options->gitmodules_done,
FSCK_MSG_GITMODULES_MISSING, FSCK_MSG_GITMODULES_BLOB,
options, ".gitmodules");
ret |= fsck_blobs(&options->gitattributes_found, &options->gitattributes_done,
FSCK_MSG_GITATTRIBUTES_MISSING, FSCK_MSG_GITATTRIBUTES_BLOB,
options, ".gitattributes");
return ret;
}
int git_fsck_config(const char *var, const char *value, void *cb)
{
struct fsck_options *options = cb;
if (strcmp(var, "fsck.skiplist") == 0) {
const char *path;
struct strbuf sb = STRBUF_INIT;
if (git_config_pathname(&path, var, value))
return 1;
strbuf_addf(&sb, "skiplist=%s", path);
free((char *)path);
fsck_set_msg_types(options, sb.buf);
strbuf_release(&sb);
return 0;
}
if (skip_prefix(var, "fsck.", &var)) {
fsck_set_msg_type(options, var, value);
return 0;
}
return git_default_config(var, value, cb);
}
/*
* Custom error callbacks that are used in more than one place.
*/
int fsck_error_cb_print_missing_gitmodules(struct fsck_options *o,
const struct object_id *oid,
enum object_type object_type,
enum fsck_msg_type msg_type,
enum fsck_msg_id msg_id,
const char *message)
{
if (msg_id == FSCK_MSG_GITMODULES_MISSING) {
puts(oid_to_hex(oid));
return 0;
}
return fsck_error_function(o, oid, object_type, msg_type, msg_id, message);
}