1/* ui-snapshot.c: generate snapshot of a commit
  2 *
  3 * Copyright (C) 2006 Lars Hjemli
  4 * Copyright (C) 2012 Jason A. Donenfeld <Jason@zx2c4.com>
  5 *
  6 * Licensed under GNU General Public License v2
  7 *   (see COPYING for full license text)
  8 */
  9
 10#include "cgit.h"
 11#include "html.h"
 12#include "ui-shared.h"
 13
 14static int write_archive_type(const char *format, const char *hex, const char *prefix)
 15{
 16	struct argv_array argv = ARGV_ARRAY_INIT;
 17	argv_array_push(&argv, "snapshot");
 18	argv_array_push(&argv, format);
 19	if (prefix) {
 20		argv_array_push(&argv, "--prefix");
 21		argv_array_push(&argv, fmt("%s/", prefix));
 22	}
 23	argv_array_push(&argv, hex);
 24	return write_archive(argv.argc, argv.argv, NULL, 1, NULL, 0);
 25}
 26
 27static int write_tar_archive(const char *hex, const char *prefix)
 28{
 29	return write_archive_type("--format=tar", hex, prefix);
 30}
 31
 32static int write_zip_archive(const char *hex, const char *prefix)
 33{
 34	return write_archive_type("--format=zip", hex, prefix);
 35}
 36
 37static int write_compressed_tar_archive(const char *hex,
 38					const char *prefix,
 39					char *filter_argv[])
 40{
 41	int rv;
 42	struct cgit_filter f;
 43
 44	f.cmd = filter_argv[0];
 45	f.argv = filter_argv;
 46	cgit_open_filter(&f);
 47	rv = write_tar_archive(hex, prefix);
 48	cgit_close_filter(&f);
 49	return rv;
 50}
 51
 52static int write_tar_gzip_archive(const char *hex, const char *prefix)
 53{
 54	char *argv[] = { "gzip", "-n", NULL };
 55	return write_compressed_tar_archive(hex, prefix, argv);
 56}
 57
 58static int write_tar_bzip2_archive(const char *hex, const char *prefix)
 59{
 60	char *argv[] = { "bzip2", NULL };
 61	return write_compressed_tar_archive(hex, prefix, argv);
 62}
 63
 64static int write_tar_xz_archive(const char *hex, const char *prefix)
 65{
 66	char *argv[] = { "xz", NULL };
 67	return write_compressed_tar_archive(hex, prefix, argv);
 68}
 69
 70const struct cgit_snapshot_format cgit_snapshot_formats[] = {
 71	{ ".zip", "application/x-zip", write_zip_archive, 0x01 },
 72	{ ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x02 },
 73	{ ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x04 },
 74	{ ".tar", "application/x-tar", write_tar_archive, 0x08 },
 75	{ ".tar.xz", "application/x-xz", write_tar_xz_archive, 0x10 },
 76	{ NULL }
 77};
 78
 79static const struct cgit_snapshot_format *get_format(const char *filename)
 80{
 81	const struct cgit_snapshot_format *fmt;
 82	int fl, sl;
 83
 84	fl = strlen(filename);
 85	for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
 86		sl = strlen(fmt->suffix);
 87		if (sl >= fl)
 88			continue;
 89		if (!strcmp(fmt->suffix, filename + fl - sl))
 90			return fmt;
 91	}
 92	return NULL;
 93}
 94
 95static int make_snapshot(const struct cgit_snapshot_format *format,
 96			 const char *hex, const char *prefix,
 97			 const char *filename)
 98{
 99	unsigned char sha1[20];
100
101	if (get_sha1(hex, sha1)) {
102		cgit_print_error(fmt("Bad object id: %s", hex));
103		return 1;
104	}
105	if (!lookup_commit_reference(sha1)) {
106		cgit_print_error(fmt("Not a commit reference: %s", hex));
107		return 1;
108	}
109	ctx.page.mimetype = xstrdup(format->mimetype);
110	ctx.page.filename = xstrdup(filename);
111	cgit_print_http_headers(&ctx);
112	format->write_func(hex, prefix);
113	return 0;
114}
115
116/* Try to guess the requested revision from the requested snapshot name.
117 * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
118 * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
119 * Otherwise, if the snapshot name has a prefix matching the result from
120 * repo_basename(), we strip the basename and any following '-' and '_'
121 * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
122 * more. If this still isn't a valid commit object name, we check if pre-
123 * pending a 'v' to the remaining snapshot name ("0.7.2" -> "v0.7.2") gives
124 * us something valid.
125 */
126static const char *get_ref_from_filename(const char *url, const char *filename,
127					 const struct cgit_snapshot_format *format)
128{
129	const char *reponame;
130	unsigned char sha1[20];
131	char *snapshot;
132
133	snapshot = xstrdup(filename);
134	snapshot[strlen(snapshot) - strlen(format->suffix)] = '\0';
135
136	if (get_sha1(snapshot, sha1) == 0)
137		return snapshot;
138
139	reponame = cgit_repobasename(url);
140	if (prefixcmp(snapshot, reponame) == 0) {
141		snapshot += strlen(reponame);
142		while (snapshot && (*snapshot == '-' || *snapshot == '_'))
143			snapshot++;
144	}
145
146	if (get_sha1(snapshot, sha1) == 0)
147		return snapshot;
148
149	snapshot = fmt("v%s", snapshot);
150	if (get_sha1(snapshot, sha1) == 0)
151		return snapshot;
152
153	return NULL;
154}
155
156static void show_error(char *msg)
157{
158	ctx.page.mimetype = "text/html";
159	cgit_print_http_headers(&ctx);
160	cgit_print_docstart(&ctx);
161	cgit_print_pageheader(&ctx);
162	cgit_print_error(msg);
163	cgit_print_docend();
164}
165
166void cgit_print_snapshot(const char *head, const char *hex,
167			 const char *filename, int snapshots, int dwim)
168{
169	const struct cgit_snapshot_format* f;
170	char *prefix = NULL;
171
172	if (!filename) {
173		show_error("No snapshot name specified");
174		return;
175	}
176
177	f = get_format(filename);
178	if (!f) {
179		show_error(xstrdup(fmt("Unsupported snapshot format: %s",
180				       filename)));
181		return;
182	}
183
184	if (!hex && dwim) {
185		hex = get_ref_from_filename(ctx.repo->url, filename, f);
186		if (hex == NULL) {
187			html_status(404, "Not found", 0);
188			return;
189		}
190		prefix = xstrdup(filename);
191		prefix[strlen(filename) - strlen(f->suffix)] = '\0';
192	}
193
194	if (!hex)
195		hex = head;
196
197	if (!prefix)
198		prefix = xstrdup(cgit_repobasename(ctx.repo->url));
199
200	make_snapshot(f, hex, prefix, filename);
201	free(prefix);
202}