aboutsummaryrefslogtreecommitdiffstats
path: root/ui-snapshot.c
blob: 42b7489d5b4048248b9223cfc14a437fabdeba09 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
/* ui-snapshot.c: generate snapshot of a commit
 *
 * Copyright (C) 2006 Lars Hjemli
 * Copyright (C) 2012 Jason A. Donenfeld <Jason@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, 1, 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_filter f;

	f.cmd = filter_argv[0];
	f.argv = filter_argv;
	cgit_open_filter(&f);
	rv = write_tar_archive(hex, prefix);
	cgit_close_filter(&f);
	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;
	int fl, sl;

	fl = strlen(filename);
	for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
		sl = strlen(fmt->suffix);
		if (sl >= fl)
			continue;
		if (!strcmp(fmt->suffix, filename + fl - sl))
			return fmt;
	}
	return NULL;
}

static int make_snapshot(const struct cgit_snapshot_format *format,
			 const char *hex, const char *prefix,
			 const char *filename)
{
	unsigned char sha1[20];

	if (get_sha1(hex, sha1)) {
		cgit_print_error("Bad object id: %s", hex);
		return 1;
	}
	if (!lookup_commit_reference(sha1)) {
		cgit_print_error("Not a commit reference: %s", hex);
		return 1;
	}
	ctx.page.mimetype = xstrdup(format->mimetype);
	ctx.page.filename = xstrdup(filename);
	cgit_print_http_headers(&ctx);
	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 char *url, const char *filename,
					 const struct cgit_snapshot_format *format)
{
	const char *reponame;
	unsigned char sha1[20];
	struct strbuf snapshot = STRBUF_INIT;
	int result = 1;

	strbuf_addstr(&snapshot, filename);
	strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));

	if (get_sha1(snapshot.buf, sha1) == 0)
		goto out;

	reponame = cgit_repobasename(url);
	if (prefixcmp(snapshot.buf, reponame) == 0) {
		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_sha1(snapshot.buf, sha1) == 0)
		goto out;

	strbuf_insert(&snapshot, 0, "v", 1);
	if (get_sha1(snapshot.buf, sha1) == 0)
		goto out;

	strbuf_splice(&snapshot, 0, 1, "V", 1);
	if (get_sha1(snapshot.buf, sha1) == 0)
		goto out;

	result = 0;
	strbuf_release(&snapshot);

out:
	return result ? strbuf_detach(&snapshot, NULL) : NULL;
}

__attribute__((format (printf, 1, 2)))
static void show_error(char *fmt, ...)
{
	va_list ap;

	ctx.page.mimetype = "text/html";
	cgit_print_http_headers(&ctx);
	cgit_print_docstart(&ctx);
	cgit_print_pageheader(&ctx);
	va_start(ap, fmt);
	cgit_vprint_error(fmt, ap);
	va_end(ap);
	cgit_print_docend();
}

void cgit_print_snapshot(const char *head, const char *hex,
			 const char *filename, int snapshots, int dwim)
{
	const struct cgit_snapshot_format* f;
	char *prefix = NULL;

	if (!filename) {
		show_error("No snapshot name specified");
		return;
	}

	f = get_format(filename);
	if (!f) {
		show_error("Unsupported snapshot format: %s", filename);
		return;
	}

	if (!hex && dwim) {
		hex = get_ref_from_filename(ctx.repo->url, filename, f);
		if (hex == NULL) {
			html_status(404, "Not found", 0);
			return;
		}
		prefix = xstrdup(filename);
		prefix[strlen(filename) - strlen(f->suffix)] = '\0';
	}

	if (!hex)
		hex = head;

	if (!prefix)
		prefix = xstrdup(cgit_repobasename(ctx.repo->url));

	make_snapshot(f, hex, prefix, filename);
	free(prefix);
}