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