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git/archive.c
Jeff King 50a6c8efa2 use st_add and st_mult for allocation size computation
If our size computation overflows size_t, we may allocate a
much smaller buffer than we expected and overflow it. It's
probably impossible to trigger an overflow in most of these
sites in practice, but it is easy enough convert their
additions and multiplications into overflow-checking
variants. This may be fixing real bugs, and it makes
auditing the code easier.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22 14:51:09 -08:00

560 lines
15 KiB
C

#include "cache.h"
#include "refs.h"
#include "commit.h"
#include "tree-walk.h"
#include "attr.h"
#include "archive.h"
#include "parse-options.h"
#include "unpack-trees.h"
#include "dir.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;
static int remote_allow_unreachable;
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.type = 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 directory {
struct directory *up;
struct object_id oid;
int baselen, len;
unsigned mode;
int stage;
char path[FLEX_ARRAY];
};
struct archiver_context {
struct archiver_args *args;
write_archive_entry_fn_t write_entry;
struct directory *bottom;
};
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);
}
static int write_archive_entry_buf(const unsigned char *sha1, struct strbuf *base,
const char *filename, unsigned mode, int stage,
void *context)
{
return write_archive_entry(sha1, base->buf, base->len,
filename, mode, stage, context);
}
static void queue_directory(const unsigned char *sha1,
struct strbuf *base, const char *filename,
unsigned mode, int stage, struct archiver_context *c)
{
struct directory *d;
size_t len = st_add4(base->len, 1, strlen(filename), 1);
d = xmalloc(st_add(sizeof(*d), len));
d->up = c->bottom;
d->baselen = base->len;
d->mode = mode;
d->stage = stage;
c->bottom = d;
d->len = xsnprintf(d->path, len, "%.*s%s/", (int)base->len, base->buf, filename);
hashcpy(d->oid.hash, sha1);
}
static int write_directory(struct archiver_context *c)
{
struct directory *d = c->bottom;
int ret;
if (!d)
return 0;
c->bottom = d->up;
d->path[d->len - 1] = '\0'; /* no trailing slash */
ret =
write_directory(c) ||
write_archive_entry(d->oid.hash, d->path, d->baselen,
d->path + d->baselen, d->mode,
d->stage, c) != READ_TREE_RECURSIVE;
free(d);
return ret ? -1 : 0;
}
static int queue_or_write_archive_entry(const unsigned char *sha1,
struct strbuf *base, const char *filename,
unsigned mode, int stage, void *context)
{
struct archiver_context *c = context;
while (c->bottom &&
!(base->len >= c->bottom->len &&
!strncmp(base->buf, c->bottom->path, c->bottom->len))) {
struct directory *next = c->bottom->up;
free(c->bottom);
c->bottom = next;
}
if (S_ISDIR(mode)) {
queue_directory(sha1, base, filename,
mode, stage, c);
return READ_TREE_RECURSIVE;
}
if (write_directory(c))
return -1;
return write_archive_entry(sha1, base->buf, base->len, filename, mode,
stage, context);
}
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.oid.hash, args->base,
len, 040777);
if (err)
return err;
}
memset(&context, 0, sizeof(context));
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,
args->pathspec.has_wildcard ?
queue_or_write_archive_entry :
write_archive_entry_buf,
&context);
if (err == READ_TREE_RECURSIVE)
err = 0;
while (context.bottom) {
struct directory *next = context.bottom->up;
free(context.bottom);
context.bottom = next;
}
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, struct strbuf *base,
const char *filename, unsigned mode,
int stage, void *context)
{
int ret = -1;
if (S_ISDIR(mode)) {
struct strbuf sb = STRBUF_INIT;
strbuf_addbuf(&sb, base);
strbuf_addstr(&sb, filename);
if (!match_pathspec(context, sb.buf, sb.len, 0, NULL, 1))
ret = READ_TREE_RECURSIVE;
strbuf_release(&sb);
}
return ret;
}
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);
pathspec.recursive = 1;
ret = read_tree_recursive(tree, "", 0, 0, &pathspec,
reject_entry, &pathspec);
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);
ar_args->pathspec.recursive = 1;
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;
struct object_id oid;
/* Remotes are only allowed to fetch actual refs */
if (remote && !remote_allow_unreachable) {
char *ref = NULL;
const char *colon = strchrnul(name, ':');
int refnamelen = colon - name;
if (!dwim_ref(name, refnamelen, oid.hash, &ref))
die("no such ref: %.*s", refnamelen, name);
free(ref);
}
if (get_sha1(name, oid.hash))
die("Not a valid object name");
commit = lookup_commit_reference_gently(oid.hash, 1);
if (commit) {
commit_sha1 = commit->object.oid.hash;
archive_time = commit->date;
} else {
commit_sha1 = NULL;
archive_time = time(NULL);
}
tree = parse_tree_indirect(oid.hash);
if (tree == NULL)
die("not a tree object");
if (prefix) {
struct object_id tree_oid;
unsigned int mode;
int err;
err = get_tree_entry(tree->object.oid.hash, prefix,
tree_oid.hash, &mode);
if (err || !S_ISDIR(mode))
die("current working directory is untracked");
tree = parse_tree_indirect(tree_oid.hash);
}
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_get_bool("uploadarchive.allowunreachable", &remote_allow_unreachable);
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;
}