Revision 1d1d69bc52dcc7def5b2edbd165cc0a4e3911c8e authored by Johannes Schindelin on 16 December 2014, 22:31:03 UTC, committed by Junio C Hamano on 17 December 2014, 19:04:45 UTC
We do not allow paths with a ".git" component to be added to the index, as that would mean repository contents could overwrite our repository files. However, asking "is this path the same as .git" is not as simple as strcmp() on some filesystems. On NTFS (and FAT32), there exist so-called "short names" for backwards-compatibility: 8.3 compliant names that refer to the same files as their long names. As ".git" is not an 8.3 compliant name, a short name is generated automatically, typically "git~1". Depending on the Windows version, any combination of trailing spaces and periods are ignored, too, so that both "git~1." and ".git." still refer to the Git directory. The reason is that 8.3 stores file names shorter than 8 characters with trailing spaces. So literally, it does not matter for the short name whether it is padded with spaces or whether it is shorter than 8 characters, it is considered to be the exact same. The period is the separator between file name and file extension, and again, an empty extension consists just of spaces in 8.3 format. So technically, we would need only take care of the equivalent of this regex: (\.git {0,4}|git~1 {0,3})\. {0,3} However, there are indications that at least some Windows versions might be more lenient and accept arbitrary combinations of trailing spaces and periods and strip them out. So we're playing it real safe here. Besides, there can be little doubt about the intention behind using file names matching even the more lenient pattern specified above, therefore we should be fine with disallowing such patterns. Extra care is taken to catch names such as '.\\.git\\booh' because the backslash is marked as a directory separator only on Windows, and we want to use this new helper function also in fsck on other platforms. A big thank you goes to Ed Thomson and an unnamed Microsoft engineer for the detailed analysis performed to come up with the corresponding fixes for libgit2. This commit adds a function to detect whether a given file name can refer to the Git directory by mistake. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent a18fcc9
archive.c
#include "cache.h"
#include "commit.h"
#include "tree-walk.h"
#include "attr.h"
#include "archive.h"
#include "parse-options.h"
#include "unpack-trees.h"
static char const * const archive_usage[] = {
N_("git archive [options] <tree-ish> [<path>...]"),
N_("git archive --list"),
N_("git archive --remote <repo> [--exec <cmd>] [options] <tree-ish> [<path>...]"),
N_("git archive --remote <repo> [--exec <cmd>] --list"),
NULL
};
static const struct archiver **archivers;
static int nr_archivers;
static int alloc_archivers;
void register_archiver(struct archiver *ar)
{
ALLOC_GROW(archivers, nr_archivers + 1, alloc_archivers);
archivers[nr_archivers++] = ar;
}
static void format_subst(const struct commit *commit,
const char *src, size_t len,
struct strbuf *buf)
{
char *to_free = NULL;
struct strbuf fmt = STRBUF_INIT;
struct pretty_print_context ctx = {0};
ctx.date_mode = DATE_NORMAL;
ctx.abbrev = DEFAULT_ABBREV;
if (src == buf->buf)
to_free = strbuf_detach(buf, NULL);
for (;;) {
const char *b, *c;
b = memmem(src, len, "$Format:", 8);
if (!b)
break;
c = memchr(b + 8, '$', (src + len) - b - 8);
if (!c)
break;
strbuf_reset(&fmt);
strbuf_add(&fmt, b + 8, c - b - 8);
strbuf_add(buf, src, b - src);
format_commit_message(commit, fmt.buf, buf, &ctx);
len -= c + 1 - src;
src = c + 1;
}
strbuf_add(buf, src, len);
strbuf_release(&fmt);
free(to_free);
}
void *sha1_file_to_archive(const struct archiver_args *args,
const char *path, const unsigned char *sha1,
unsigned int mode, enum object_type *type,
unsigned long *sizep)
{
void *buffer;
const struct commit *commit = args->convert ? args->commit : NULL;
path += args->baselen;
buffer = read_sha1_file(sha1, type, sizep);
if (buffer && S_ISREG(mode)) {
struct strbuf buf = STRBUF_INIT;
size_t size = 0;
strbuf_attach(&buf, buffer, *sizep, *sizep + 1);
convert_to_working_tree(path, buf.buf, buf.len, &buf);
if (commit)
format_subst(commit, buf.buf, buf.len, &buf);
buffer = strbuf_detach(&buf, &size);
*sizep = size;
}
return buffer;
}
static void setup_archive_check(struct git_attr_check *check)
{
static struct git_attr *attr_export_ignore;
static struct git_attr *attr_export_subst;
if (!attr_export_ignore) {
attr_export_ignore = git_attr("export-ignore");
attr_export_subst = git_attr("export-subst");
}
check[0].attr = attr_export_ignore;
check[1].attr = attr_export_subst;
}
struct archiver_context {
struct archiver_args *args;
write_archive_entry_fn_t write_entry;
};
static int write_archive_entry(const unsigned char *sha1, const char *base,
int baselen, const char *filename, unsigned mode, int stage,
void *context)
{
static struct strbuf path = STRBUF_INIT;
struct archiver_context *c = context;
struct archiver_args *args = c->args;
write_archive_entry_fn_t write_entry = c->write_entry;
struct git_attr_check check[2];
const char *path_without_prefix;
int err;
args->convert = 0;
strbuf_reset(&path);
strbuf_grow(&path, PATH_MAX);
strbuf_add(&path, args->base, args->baselen);
strbuf_add(&path, base, baselen);
strbuf_addstr(&path, filename);
if (S_ISDIR(mode) || S_ISGITLINK(mode))
strbuf_addch(&path, '/');
path_without_prefix = path.buf + args->baselen;
setup_archive_check(check);
if (!git_check_attr(path_without_prefix, ARRAY_SIZE(check), check)) {
if (ATTR_TRUE(check[0].value))
return 0;
args->convert = ATTR_TRUE(check[1].value);
}
if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
if (args->verbose)
fprintf(stderr, "%.*s\n", (int)path.len, path.buf);
err = write_entry(args, sha1, path.buf, path.len, mode);
if (err)
return err;
return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
}
if (args->verbose)
fprintf(stderr, "%.*s\n", (int)path.len, path.buf);
return write_entry(args, sha1, path.buf, path.len, mode);
}
int write_archive_entries(struct archiver_args *args,
write_archive_entry_fn_t write_entry)
{
struct archiver_context context;
struct unpack_trees_options opts;
struct tree_desc t;
int err;
if (args->baselen > 0 && args->base[args->baselen - 1] == '/') {
size_t len = args->baselen;
while (len > 1 && args->base[len - 2] == '/')
len--;
if (args->verbose)
fprintf(stderr, "%.*s\n", (int)len, args->base);
err = write_entry(args, args->tree->object.sha1, args->base,
len, 040777);
if (err)
return err;
}
context.args = args;
context.write_entry = write_entry;
/*
* Setup index and instruct attr to read index only
*/
if (!args->worktree_attributes) {
memset(&opts, 0, sizeof(opts));
opts.index_only = 1;
opts.head_idx = -1;
opts.src_index = &the_index;
opts.dst_index = &the_index;
opts.fn = oneway_merge;
init_tree_desc(&t, args->tree->buffer, args->tree->size);
if (unpack_trees(1, &t, &opts))
return -1;
git_attr_set_direction(GIT_ATTR_INDEX, &the_index);
}
err = read_tree_recursive(args->tree, "", 0, 0, &args->pathspec,
write_archive_entry, &context);
if (err == READ_TREE_RECURSIVE)
err = 0;
return err;
}
static const struct archiver *lookup_archiver(const char *name)
{
int i;
if (!name)
return NULL;
for (i = 0; i < nr_archivers; i++) {
if (!strcmp(name, archivers[i]->name))
return archivers[i];
}
return NULL;
}
static int reject_entry(const unsigned char *sha1, const char *base,
int baselen, const char *filename, unsigned mode,
int stage, void *context)
{
return -1;
}
static int path_exists(struct tree *tree, const char *path)
{
const char *paths[] = { path, NULL };
struct pathspec pathspec;
int ret;
parse_pathspec(&pathspec, 0, 0, "", paths);
ret = read_tree_recursive(tree, "", 0, 0, &pathspec, reject_entry, NULL);
free_pathspec(&pathspec);
return ret != 0;
}
static void parse_pathspec_arg(const char **pathspec,
struct archiver_args *ar_args)
{
/*
* must be consistent with parse_pathspec in path_exists()
* Also if pathspec patterns are dependent, we're in big
* trouble as we test each one separately
*/
parse_pathspec(&ar_args->pathspec, 0,
PATHSPEC_PREFER_FULL,
"", pathspec);
if (pathspec) {
while (*pathspec) {
if (**pathspec && !path_exists(ar_args->tree, *pathspec))
die(_("pathspec '%s' did not match any files"), *pathspec);
pathspec++;
}
}
}
static void parse_treeish_arg(const char **argv,
struct archiver_args *ar_args, const char *prefix,
int remote)
{
const char *name = argv[0];
const unsigned char *commit_sha1;
time_t archive_time;
struct tree *tree;
const struct commit *commit;
unsigned char sha1[20];
/* Remotes are only allowed to fetch actual refs */
if (remote) {
char *ref = NULL;
const char *colon = strchr(name, ':');
int refnamelen = colon ? colon - name : strlen(name);
if (!dwim_ref(name, refnamelen, sha1, &ref))
die("no such ref: %.*s", refnamelen, name);
free(ref);
}
if (get_sha1(name, sha1))
die("Not a valid object name");
commit = lookup_commit_reference_gently(sha1, 1);
if (commit) {
commit_sha1 = commit->object.sha1;
archive_time = commit->date;
} else {
commit_sha1 = NULL;
archive_time = time(NULL);
}
tree = parse_tree_indirect(sha1);
if (tree == NULL)
die("not a tree object");
if (prefix) {
unsigned char tree_sha1[20];
unsigned int mode;
int err;
err = get_tree_entry(tree->object.sha1, prefix,
tree_sha1, &mode);
if (err || !S_ISDIR(mode))
die("current working directory is untracked");
tree = parse_tree_indirect(tree_sha1);
}
ar_args->tree = tree;
ar_args->commit_sha1 = commit_sha1;
ar_args->commit = commit;
ar_args->time = archive_time;
}
#define OPT__COMPR(s, v, h, p) \
{ OPTION_SET_INT, (s), NULL, (v), NULL, (h), \
PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, (p) }
#define OPT__COMPR_HIDDEN(s, v, p) \
{ OPTION_SET_INT, (s), NULL, (v), NULL, "", \
PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_HIDDEN, NULL, (p) }
static int parse_archive_args(int argc, const char **argv,
const struct archiver **ar, struct archiver_args *args,
const char *name_hint, int is_remote)
{
const char *format = NULL;
const char *base = NULL;
const char *remote = NULL;
const char *exec = NULL;
const char *output = NULL;
int compression_level = -1;
int verbose = 0;
int i;
int list = 0;
int worktree_attributes = 0;
struct option opts[] = {
OPT_GROUP(""),
OPT_STRING(0, "format", &format, N_("fmt"), N_("archive format")),
OPT_STRING(0, "prefix", &base, N_("prefix"),
N_("prepend prefix to each pathname in the archive")),
OPT_STRING('o', "output", &output, N_("file"),
N_("write the archive to this file")),
OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
N_("read .gitattributes in working directory")),
OPT__VERBOSE(&verbose, N_("report archived files on stderr")),
OPT__COMPR('0', &compression_level, N_("store only"), 0),
OPT__COMPR('1', &compression_level, N_("compress faster"), 1),
OPT__COMPR_HIDDEN('2', &compression_level, 2),
OPT__COMPR_HIDDEN('3', &compression_level, 3),
OPT__COMPR_HIDDEN('4', &compression_level, 4),
OPT__COMPR_HIDDEN('5', &compression_level, 5),
OPT__COMPR_HIDDEN('6', &compression_level, 6),
OPT__COMPR_HIDDEN('7', &compression_level, 7),
OPT__COMPR_HIDDEN('8', &compression_level, 8),
OPT__COMPR('9', &compression_level, N_("compress better"), 9),
OPT_GROUP(""),
OPT_BOOL('l', "list", &list,
N_("list supported archive formats")),
OPT_GROUP(""),
OPT_STRING(0, "remote", &remote, N_("repo"),
N_("retrieve the archive from remote repository <repo>")),
OPT_STRING(0, "exec", &exec, N_("command"),
N_("path to the remote git-upload-archive command")),
OPT_END()
};
argc = parse_options(argc, argv, NULL, opts, archive_usage, 0);
if (remote)
die("Unexpected option --remote");
if (exec)
die("Option --exec can only be used together with --remote");
if (output)
die("Unexpected option --output");
if (!base)
base = "";
if (list) {
for (i = 0; i < nr_archivers; i++)
if (!is_remote || archivers[i]->flags & ARCHIVER_REMOTE)
printf("%s\n", archivers[i]->name);
exit(0);
}
if (!format && name_hint)
format = archive_format_from_filename(name_hint);
if (!format)
format = "tar";
/* We need at least one parameter -- tree-ish */
if (argc < 1)
usage_with_options(archive_usage, opts);
*ar = lookup_archiver(format);
if (!*ar || (is_remote && !((*ar)->flags & ARCHIVER_REMOTE)))
die("Unknown archive format '%s'", format);
args->compression_level = Z_DEFAULT_COMPRESSION;
if (compression_level != -1) {
if ((*ar)->flags & ARCHIVER_WANT_COMPRESSION_LEVELS)
args->compression_level = compression_level;
else {
die("Argument not supported for format '%s': -%d",
format, compression_level);
}
}
args->verbose = verbose;
args->base = base;
args->baselen = strlen(base);
args->worktree_attributes = worktree_attributes;
return argc;
}
int write_archive(int argc, const char **argv, const char *prefix,
int setup_prefix, const char *name_hint, int remote)
{
int nongit = 0;
const struct archiver *ar = NULL;
struct archiver_args args;
if (setup_prefix && prefix == NULL)
prefix = setup_git_directory_gently(&nongit);
git_config(git_default_config, NULL);
init_tar_archiver();
init_zip_archiver();
argc = parse_archive_args(argc, argv, &ar, &args, name_hint, remote);
if (nongit) {
/*
* We know this will die() with an error, so we could just
* die ourselves; but its error message will be more specific
* than what we could write here.
*/
setup_git_directory();
}
parse_treeish_arg(argv, &args, prefix, remote);
parse_pathspec_arg(argv + 1, &args);
return ar->write_archive(ar, &args);
}
static int match_extension(const char *filename, const char *ext)
{
int prefixlen = strlen(filename) - strlen(ext);
/*
* We need 1 character for the '.', and 1 character to ensure that the
* prefix is non-empty (k.e., we don't match .tar.gz with no actual
* filename).
*/
if (prefixlen < 2 || filename[prefixlen - 1] != '.')
return 0;
return !strcmp(filename + prefixlen, ext);
}
const char *archive_format_from_filename(const char *filename)
{
int i;
for (i = 0; i < nr_archivers; i++)
if (match_extension(filename, archivers[i]->name))
return archivers[i]->name;
return NULL;
}
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