ui-snapshot.c (view raw)
1/* ui-snapshot.c: generate snapshot of a commit
2 *
3 * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
4 *
5 * Licensed under GNU General Public License v2
6 * (see COPYING for full license text)
7 */
8
9#include "cgit.h"
10#include "ui-snapshot.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 const char **nargv;
18 int result;
19 argv_array_push(&argv, "snapshot");
20 argv_array_push(&argv, format);
21 if (prefix) {
22 struct strbuf buf = STRBUF_INIT;
23 strbuf_addstr(&buf, prefix);
24 strbuf_addch(&buf, '/');
25 argv_array_push(&argv, "--prefix");
26 argv_array_push(&argv, buf.buf);
27 strbuf_release(&buf);
28 }
29 argv_array_push(&argv, hex);
30 /*
31 * Now we need to copy the pointers to arguments into a new
32 * structure because write_archive will rearrange its arguments
33 * which may result in duplicated/missing entries causing leaks
34 * or double-frees in argv_array_clear.
35 */
36 nargv = xmalloc(sizeof(char *) * (argv.argc + 1));
37 /* argv_array guarantees a trailing NULL entry. */
38 memcpy(nargv, argv.argv, sizeof(char *) * (argv.argc + 1));
39
40 result = write_archive(argv.argc, nargv, NULL, 1, NULL, 0);
41 argv_array_clear(&argv);
42 free(nargv);
43 return result;
44}
45
46static int write_tar_archive(const char *hex, const char *prefix)
47{
48 return write_archive_type("--format=tar", hex, prefix);
49}
50
51static int write_zip_archive(const char *hex, const char *prefix)
52{
53 return write_archive_type("--format=zip", hex, prefix);
54}
55
56static int write_compressed_tar_archive(const char *hex,
57 const char *prefix,
58 char *filter_argv[])
59{
60 int rv;
61 struct cgit_exec_filter f;
62 cgit_exec_filter_init(&f, filter_argv[0], filter_argv);
63
64 cgit_open_filter(&f.base);
65 rv = write_tar_archive(hex, prefix);
66 cgit_close_filter(&f.base);
67 return rv;
68}
69
70static int write_tar_gzip_archive(const char *hex, const char *prefix)
71{
72 char *argv[] = { "gzip", "-n", NULL };
73 return write_compressed_tar_archive(hex, prefix, argv);
74}
75
76static int write_tar_bzip2_archive(const char *hex, const char *prefix)
77{
78 char *argv[] = { "bzip2", NULL };
79 return write_compressed_tar_archive(hex, prefix, argv);
80}
81
82static int write_tar_xz_archive(const char *hex, const char *prefix)
83{
84 char *argv[] = { "xz", NULL };
85 return write_compressed_tar_archive(hex, prefix, argv);
86}
87
88const struct cgit_snapshot_format cgit_snapshot_formats[] = {
89 { ".zip", "application/x-zip", write_zip_archive, 0x01 },
90 { ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x02 },
91 { ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x04 },
92 { ".tar", "application/x-tar", write_tar_archive, 0x08 },
93 { ".tar.xz", "application/x-xz", write_tar_xz_archive, 0x10 },
94 { NULL }
95};
96
97static const struct cgit_snapshot_format *get_format(const char *filename)
98{
99 const struct cgit_snapshot_format *fmt;
100
101 for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
102 if (ends_with(filename, fmt->suffix))
103 return fmt;
104 }
105 return NULL;
106}
107
108static int make_snapshot(const struct cgit_snapshot_format *format,
109 const char *hex, const char *prefix,
110 const char *filename)
111{
112 unsigned char sha1[20];
113
114 if (get_sha1(hex, sha1)) {
115 cgit_print_error_page(404, "Not found",
116 "Bad object id: %s", hex);
117 return 1;
118 }
119 if (!lookup_commit_reference(sha1)) {
120 cgit_print_error_page(400, "Bad request",
121 "Not a commit reference: %s", hex);
122 return 1;
123 }
124 ctx.page.etag = sha1_to_hex(sha1);
125 ctx.page.mimetype = xstrdup(format->mimetype);
126 ctx.page.filename = xstrdup(filename);
127 cgit_print_http_headers();
128 format->write_func(hex, prefix);
129 return 0;
130}
131
132/* Try to guess the requested revision from the requested snapshot name.
133 * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
134 * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
135 * Otherwise, if the snapshot name has a prefix matching the result from
136 * repo_basename(), we strip the basename and any following '-' and '_'
137 * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
138 * more. If this still isn't a valid commit object name, we check if pre-
139 * pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
140 * "v0.7.2") gives us something valid.
141 */
142static const char *get_ref_from_filename(const char *url, const char *filename,
143 const struct cgit_snapshot_format *format)
144{
145 const char *reponame;
146 unsigned char sha1[20];
147 struct strbuf snapshot = STRBUF_INIT;
148 int result = 1;
149
150 strbuf_addstr(&snapshot, filename);
151 strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
152
153 if (get_sha1(snapshot.buf, sha1) == 0)
154 goto out;
155
156 reponame = cgit_repobasename(url);
157 if (starts_with(snapshot.buf, reponame)) {
158 const char *new_start = snapshot.buf;
159 new_start += strlen(reponame);
160 while (new_start && (*new_start == '-' || *new_start == '_'))
161 new_start++;
162 strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
163 }
164
165 if (get_sha1(snapshot.buf, sha1) == 0)
166 goto out;
167
168 strbuf_insert(&snapshot, 0, "v", 1);
169 if (get_sha1(snapshot.buf, sha1) == 0)
170 goto out;
171
172 strbuf_splice(&snapshot, 0, 1, "V", 1);
173 if (get_sha1(snapshot.buf, sha1) == 0)
174 goto out;
175
176 result = 0;
177 strbuf_release(&snapshot);
178
179out:
180 return result ? strbuf_detach(&snapshot, NULL) : NULL;
181}
182
183void cgit_print_snapshot(const char *head, const char *hex,
184 const char *filename, int dwim)
185{
186 const struct cgit_snapshot_format* f;
187 char *prefix = NULL;
188
189 if (!filename) {
190 cgit_print_error_page(400, "Bad request",
191 "No snapshot name specified");
192 return;
193 }
194
195 f = get_format(filename);
196 if (!f) {
197 cgit_print_error_page(400, "Bad request",
198 "Unsupported snapshot format: %s", filename);
199 return;
200 }
201
202 if (!hex && dwim) {
203 hex = get_ref_from_filename(ctx.repo->url, filename, f);
204 if (hex == NULL) {
205 cgit_print_error_page(404, "Not found", "Not found");
206 return;
207 }
208 prefix = xstrdup(filename);
209 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
210 }
211
212 if (!hex)
213 hex = head;
214
215 if (!prefix)
216 prefix = xstrdup(cgit_repobasename(ctx.repo->url));
217
218 make_snapshot(f, hex, prefix, filename);
219 free(prefix);
220}