cgitsb/ui-snapshot.c
John Keeping 00ad47bbfa ui-snapshot: filter permitted snapshot requests
Currently the snapshots configuration option only filters which links
are displayed, not which snapshots may be generated and downloaded.
Apply the filter also to requests to ensure that the system policy is
enforced.

Signed-off-by: John Keeping <john@keeping.me.uk>
Reviewed-by: Christian Hesse <mail@eworm.de>
2018-06-27 18:11:19 +02:00

222 lines
6.0 KiB
C

/* ui-snapshot.c: generate snapshot of a commit
*
* Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
*
* Licensed under GNU General Public License v2
* (see COPYING for full license text)
*/
#include "cgit.h"
#include "ui-snapshot.h"
#include "html.h"
#include "ui-shared.h"
static int write_archive_type(const char *format, const char *hex, const char *prefix)
{
struct argv_array argv = ARGV_ARRAY_INIT;
const char **nargv;
int result;
argv_array_push(&argv, "snapshot");
argv_array_push(&argv, format);
if (prefix) {
struct strbuf buf = STRBUF_INIT;
strbuf_addstr(&buf, prefix);
strbuf_addch(&buf, '/');
argv_array_push(&argv, "--prefix");
argv_array_push(&argv, buf.buf);
strbuf_release(&buf);
}
argv_array_push(&argv, hex);
/*
* Now we need to copy the pointers to arguments into a new
* structure because write_archive will rearrange its arguments
* which may result in duplicated/missing entries causing leaks
* or double-frees in argv_array_clear.
*/
nargv = xmalloc(sizeof(char *) * (argv.argc + 1));
/* argv_array guarantees a trailing NULL entry. */
memcpy(nargv, argv.argv, sizeof(char *) * (argv.argc + 1));
result = write_archive(argv.argc, nargv, NULL, NULL, 0);
argv_array_clear(&argv);
free(nargv);
return result;
}
static int write_tar_archive(const char *hex, const char *prefix)
{
return write_archive_type("--format=tar", hex, prefix);
}
static int write_zip_archive(const char *hex, const char *prefix)
{
return write_archive_type("--format=zip", hex, prefix);
}
static int write_compressed_tar_archive(const char *hex,
const char *prefix,
char *filter_argv[])
{
int rv;
struct cgit_exec_filter f;
cgit_exec_filter_init(&f, filter_argv[0], filter_argv);
cgit_open_filter(&f.base);
rv = write_tar_archive(hex, prefix);
cgit_close_filter(&f.base);
return rv;
}
static int write_tar_gzip_archive(const char *hex, const char *prefix)
{
char *argv[] = { "gzip", "-n", NULL };
return write_compressed_tar_archive(hex, prefix, argv);
}
static int write_tar_bzip2_archive(const char *hex, const char *prefix)
{
char *argv[] = { "bzip2", NULL };
return write_compressed_tar_archive(hex, prefix, argv);
}
static int write_tar_xz_archive(const char *hex, const char *prefix)
{
char *argv[] = { "xz", NULL };
return write_compressed_tar_archive(hex, prefix, argv);
}
const struct cgit_snapshot_format cgit_snapshot_formats[] = {
{ ".zip", "application/x-zip", write_zip_archive, 0x01 },
{ ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x02 },
{ ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x04 },
{ ".tar", "application/x-tar", write_tar_archive, 0x08 },
{ ".tar.xz", "application/x-xz", write_tar_xz_archive, 0x10 },
{ NULL }
};
static const struct cgit_snapshot_format *get_format(const char *filename)
{
const struct cgit_snapshot_format *fmt;
for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
if (ends_with(filename, fmt->suffix))
return fmt;
}
return NULL;
}
static int make_snapshot(const struct cgit_snapshot_format *format,
const char *hex, const char *prefix,
const char *filename)
{
struct object_id oid;
if (get_oid(hex, &oid)) {
cgit_print_error_page(404, "Not found",
"Bad object id: %s", hex);
return 1;
}
if (!lookup_commit_reference(&oid)) {
cgit_print_error_page(400, "Bad request",
"Not a commit reference: %s", hex);
return 1;
}
ctx.page.etag = oid_to_hex(&oid);
ctx.page.mimetype = xstrdup(format->mimetype);
ctx.page.filename = xstrdup(filename);
cgit_print_http_headers();
format->write_func(hex, prefix);
return 0;
}
/* Try to guess the requested revision from the requested snapshot name.
* First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
* "cgit-0.7.2". If this is a valid commit object name we've got a winner.
* Otherwise, if the snapshot name has a prefix matching the result from
* repo_basename(), we strip the basename and any following '-' and '_'
* characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
* more. If this still isn't a valid commit object name, we check if pre-
* pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
* "v0.7.2") gives us something valid.
*/
static const char *get_ref_from_filename(const struct cgit_repo *repo,
const char *filename,
const struct cgit_snapshot_format *format)
{
const char *reponame;
struct object_id oid;
struct strbuf snapshot = STRBUF_INIT;
int result = 1;
strbuf_addstr(&snapshot, filename);
strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
if (get_oid(snapshot.buf, &oid) == 0)
goto out;
reponame = cgit_snapshot_prefix(repo);
if (starts_with(snapshot.buf, reponame)) {
const char *new_start = snapshot.buf;
new_start += strlen(reponame);
while (new_start && (*new_start == '-' || *new_start == '_'))
new_start++;
strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
}
if (get_oid(snapshot.buf, &oid) == 0)
goto out;
strbuf_insert(&snapshot, 0, "v", 1);
if (get_oid(snapshot.buf, &oid) == 0)
goto out;
strbuf_splice(&snapshot, 0, 1, "V", 1);
if (get_oid(snapshot.buf, &oid) == 0)
goto out;
result = 0;
strbuf_release(&snapshot);
out:
return result ? strbuf_detach(&snapshot, NULL) : NULL;
}
void cgit_print_snapshot(const char *head, const char *hex,
const char *filename, int dwim)
{
const struct cgit_snapshot_format* f;
char *prefix = NULL;
if (!filename) {
cgit_print_error_page(400, "Bad request",
"No snapshot name specified");
return;
}
f = get_format(filename);
if (!f || !(ctx.repo->snapshots & f->bit)) {
cgit_print_error_page(400, "Bad request",
"Unsupported snapshot format: %s", filename);
return;
}
if (!hex && dwim) {
hex = get_ref_from_filename(ctx.repo, filename, f);
if (hex == NULL) {
cgit_print_error_page(404, "Not found", "Not found");
return;
}
prefix = xstrdup(filename);
prefix[strlen(filename) - strlen(f->suffix)] = '\0';
}
if (!hex)
hex = head;
if (!prefix)
prefix = xstrdup(cgit_snapshot_prefix(ctx.repo));
make_snapshot(f, hex, prefix, filename);
free(prefix);
}