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 "ui-snapshot.h"
 12#include "html.h"
 13#include "ui-shared.h"
 14
 15static int write_archive_type(const char *format, const char *hex, const char *prefix)
 16{
 17	struct argv_array argv = ARGV_ARRAY_INIT;
 18	argv_array_push(&argv, "snapshot");
 19	argv_array_push(&argv, format);
 20	if (prefix) {
 21		argv_array_push(&argv, "--prefix");
 22		argv_array_push(&argv, fmt("%s/", prefix));
 23	}
 24	argv_array_push(&argv, hex);
 25	return write_archive(argv.argc, argv.argv, NULL, 1, NULL, 0);
 26}
 27
 28static int write_tar_archive(const char *hex, const char *prefix)
 29{
 30	return write_archive_type("--format=tar", hex, prefix);
 31}
 32
 33static int write_zip_archive(const char *hex, const char *prefix)
 34{
 35	return write_archive_type("--format=zip", hex, prefix);
 36}
 37
 38static int write_compressed_tar_archive(const char *hex,
 39					const char *prefix,
 40					char *filter_argv[])
 41{
 42	int rv;
 43	struct cgit_filter f;
 44
 45	f.cmd = filter_argv[0];
 46	f.argv = filter_argv;
 47	cgit_open_filter(&f);
 48	rv = write_tar_archive(hex, prefix);
 49	cgit_close_filter(&f);
 50	return rv;
 51}
 52
 53static int write_tar_gzip_archive(const char *hex, const char *prefix)
 54{
 55	char *argv[] = { "gzip", "-n", NULL };
 56	return write_compressed_tar_archive(hex, prefix, argv);
 57}
 58
 59static int write_tar_bzip2_archive(const char *hex, const char *prefix)
 60{
 61	char *argv[] = { "bzip2", NULL };
 62	return write_compressed_tar_archive(hex, prefix, argv);
 63}
 64
 65static int write_tar_xz_archive(const char *hex, const char *prefix)
 66{
 67	char *argv[] = { "xz", NULL };
 68	return write_compressed_tar_archive(hex, prefix, argv);
 69}
 70
 71const struct cgit_snapshot_format cgit_snapshot_formats[] = {
 72	{ ".zip", "application/x-zip", write_zip_archive, 0x01 },
 73	{ ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x02 },
 74	{ ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x04 },
 75	{ ".tar", "application/x-tar", write_tar_archive, 0x08 },
 76	{ ".tar.xz", "application/x-xz", write_tar_xz_archive, 0x10 },
 77	{ NULL }
 78};
 79
 80static const struct cgit_snapshot_format *get_format(const char *filename)
 81{
 82	const struct cgit_snapshot_format *fmt;
 83	int fl, sl;
 84
 85	fl = strlen(filename);
 86	for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
 87		sl = strlen(fmt->suffix);
 88		if (sl >= fl)
 89			continue;
 90		if (!strcmp(fmt->suffix, filename + fl - sl))
 91			return fmt;
 92	}
 93	return NULL;
 94}
 95
 96static int make_snapshot(const struct cgit_snapshot_format *format,
 97			 const char *hex, const char *prefix,
 98			 const char *filename)
 99{
100	unsigned char sha1[20];
101
102	if (get_sha1(hex, sha1)) {
103		cgit_print_error(fmt("Bad object id: %s", hex));
104		return 1;
105	}
106	if (!lookup_commit_reference(sha1)) {
107		cgit_print_error(fmt("Not a commit reference: %s", hex));
108		return 1;
109	}
110	ctx.page.mimetype = xstrdup(format->mimetype);
111	ctx.page.filename = xstrdup(filename);
112	cgit_print_http_headers(&ctx);
113	format->write_func(hex, prefix);
114	return 0;
115}
116
117/* Try to guess the requested revision from the requested snapshot name.
118 * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
119 * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
120 * Otherwise, if the snapshot name has a prefix matching the result from
121 * repo_basename(), we strip the basename and any following '-' and '_'
122 * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
123 * more. If this still isn't a valid commit object name, we check if pre-
124 * pending a 'v' to the remaining snapshot name ("0.7.2" -> "v0.7.2") gives
125 * us something valid.
126 */
127static const char *get_ref_from_filename(const char *url, const char *filename,
128					 const struct cgit_snapshot_format *format)
129{
130	const char *reponame;
131	unsigned char sha1[20];
132	char *snapshot;
133
134	snapshot = xstrdup(filename);
135	snapshot[strlen(snapshot) - strlen(format->suffix)] = '\0';
136
137	if (get_sha1(snapshot, sha1) == 0)
138		return snapshot;
139
140	reponame = cgit_repobasename(url);
141	if (prefixcmp(snapshot, reponame) == 0) {
142		snapshot += strlen(reponame);
143		while (snapshot && (*snapshot == '-' || *snapshot == '_'))
144			snapshot++;
145	}
146
147	if (get_sha1(snapshot, sha1) == 0)
148		return snapshot;
149
150	snapshot = fmt("v%s", snapshot);
151	if (get_sha1(snapshot, sha1) == 0)
152		return snapshot;
153
154	return NULL;
155}
156
157static void show_error(char *msg)
158{
159	ctx.page.mimetype = "text/html";
160	cgit_print_http_headers(&ctx);
161	cgit_print_docstart(&ctx);
162	cgit_print_pageheader(&ctx);
163	cgit_print_error(msg);
164	cgit_print_docend();
165}
166
167void cgit_print_snapshot(const char *head, const char *hex,
168			 const char *filename, int snapshots, int dwim)
169{
170	const struct cgit_snapshot_format* f;
171	char *prefix = NULL;
172
173	if (!filename) {
174		show_error("No snapshot name specified");
175		return;
176	}
177
178	f = get_format(filename);
179	if (!f) {
180		show_error(xstrdup(fmt("Unsupported snapshot format: %s",
181				       filename)));
182		return;
183	}
184
185	if (!hex && dwim) {
186		hex = get_ref_from_filename(ctx.repo->url, filename, f);
187		if (hex == NULL) {
188			html_status(404, "Not found", 0);
189			return;
190		}
191		prefix = xstrdup(filename);
192		prefix[strlen(filename) - strlen(f->suffix)] = '\0';
193	}
194
195	if (!hex)
196		hex = head;
197
198	if (!prefix)
199		prefix = xstrdup(cgit_repobasename(ctx.repo->url));
200
201	make_snapshot(f, hex, prefix, filename);
202	free(prefix);
203}