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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
14 static 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, NULL, 0);
41         argv_array_clear(&argv);
42         free(nargv);
43         return result;
44 }
45
46 static int write_tar_archive(const char *hex, const char *prefix)
47 {
48         return write_archive_type("--format=tar", hex, prefix);
49 }
50
51 static int write_zip_archive(const char *hex, const char *prefix)
52 {
53         return write_archive_type("--format=zip", hex, prefix);
54 }
55
56 static 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
70 static 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
76 static 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
82 static 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
88 const struct cgit_snapshot_format cgit_snapshot_formats[] = {
89         /* .tar must remain the 0 index */
90         { ".tar",       "application/x-tar",    write_tar_archive       },
91         { ".tar.gz",    "application/x-gzip",   write_tar_gzip_archive  },
92         { ".tar.bz2",   "application/x-bzip2",  write_tar_bzip2_archive },
93         { ".tar.xz",    "application/x-xz",     write_tar_xz_archive    },
94         { ".zip",       "application/x-zip",    write_zip_archive       },
95         { NULL }
96 };
97
98 static struct notes_tree snapshot_sig_notes[ARRAY_SIZE(cgit_snapshot_formats)];
99
100 const struct object_id *cgit_snapshot_get_sig(const char *ref,
101                                               const struct cgit_snapshot_format *f)
102 {
103         struct notes_tree *tree;
104         struct object_id oid;
105
106         if (get_oid(ref, &oid))
107                 return NULL;
108
109         tree = &snapshot_sig_notes[f - &cgit_snapshot_formats[0]];
110         if (!tree->initialized) {
111                 struct strbuf notes_ref = STRBUF_INIT;
112
113                 strbuf_addf(&notes_ref, "refs/notes/signatures/%s",
114                             f->suffix + 1);
115
116                 init_notes(tree, notes_ref.buf, combine_notes_ignore, 0);
117                 strbuf_release(&notes_ref);
118         }
119
120         return get_note(tree, &oid);
121 }
122
123 static const struct cgit_snapshot_format *get_format(const char *filename)
124 {
125         const struct cgit_snapshot_format *fmt;
126
127         for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
128                 if (ends_with(filename, fmt->suffix))
129                         return fmt;
130         }
131         return NULL;
132 }
133
134 const unsigned cgit_snapshot_format_bit(const struct cgit_snapshot_format *f)
135 {
136         return BIT(f - &cgit_snapshot_formats[0]);
137 }
138
139 static int make_snapshot(const struct cgit_snapshot_format *format,
140                          const char *hex, const char *prefix,
141                          const char *filename)
142 {
143         struct object_id oid;
144
145         if (get_oid(hex, &oid)) {
146                 cgit_print_error_page(404, "Not found",
147                                 "Bad object id: %s", hex);
148                 return 1;
149         }
150         if (!lookup_commit_reference(&oid)) {
151                 cgit_print_error_page(400, "Bad request",
152                                 "Not a commit reference: %s", hex);
153                 return 1;
154         }
155         ctx.page.etag = oid_to_hex(&oid);
156         ctx.page.mimetype = xstrdup(format->mimetype);
157         ctx.page.filename = xstrdup(filename);
158         cgit_print_http_headers();
159         format->write_func(hex, prefix);
160         return 0;
161 }
162
163 static int write_sig(const struct cgit_snapshot_format *format,
164                      const char *hex, const char *archive,
165                      const char *filename)
166 {
167         const struct object_id *note = cgit_snapshot_get_sig(hex, format);
168         enum object_type type;
169         unsigned long size;
170         char *buf;
171
172         if (!note) {
173                 cgit_print_error_page(404, "Not found",
174                                 "No signature for %s", archive);
175                 return 0;
176         }
177
178         buf = read_object_file(note, &type, &size);
179         if (!buf) {
180                 cgit_print_error_page(404, "Not found", "Not found");
181                 return 0;
182         }
183
184         html("X-Content-Type-Options: nosniff\n");
185         html("Content-Security-Policy: default-src 'none'\n");
186         ctx.page.etag = oid_to_hex(note);
187         ctx.page.mimetype = xstrdup("application/pgp-signature");
188         ctx.page.filename = xstrdup(filename);
189         cgit_print_http_headers();
190
191         html_raw(buf, size);
192         free(buf);
193         return 0;
194 }
195
196 /* Try to guess the requested revision from the requested snapshot name.
197  * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
198  * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
199  * Otherwise, if the snapshot name has a prefix matching the result from
200  * repo_basename(), we strip the basename and any following '-' and '_'
201  * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
202  * more. If this still isn't a valid commit object name, we check if pre-
203  * pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
204  * "v0.7.2") gives us something valid.
205  */
206 static const char *get_ref_from_filename(const struct cgit_repo *repo,
207                                          const char *filename,
208                                          const struct cgit_snapshot_format *format)
209 {
210         const char *reponame;
211         struct object_id oid;
212         struct strbuf snapshot = STRBUF_INIT;
213         int result = 1;
214
215         strbuf_addstr(&snapshot, filename);
216         strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
217
218         if (get_oid(snapshot.buf, &oid) == 0)
219                 goto out;
220
221         reponame = cgit_snapshot_prefix(repo);
222         if (starts_with(snapshot.buf, reponame)) {
223                 const char *new_start = snapshot.buf;
224                 new_start += strlen(reponame);
225                 while (new_start && (*new_start == '-' || *new_start == '_'))
226                         new_start++;
227                 strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
228         }
229
230         if (get_oid(snapshot.buf, &oid) == 0)
231                 goto out;
232
233         strbuf_insert(&snapshot, 0, "v", 1);
234         if (get_oid(snapshot.buf, &oid) == 0)
235                 goto out;
236
237         strbuf_splice(&snapshot, 0, 1, "V", 1);
238         if (get_oid(snapshot.buf, &oid) == 0)
239                 goto out;
240
241         result = 0;
242         strbuf_release(&snapshot);
243
244 out:
245         return result ? strbuf_detach(&snapshot, NULL) : NULL;
246 }
247
248 void cgit_print_snapshot(const char *head, const char *hex,
249                          const char *filename, int dwim)
250 {
251         const struct cgit_snapshot_format* f;
252         const char *sig_filename = NULL;
253         char *adj_filename = NULL;
254         char *prefix = NULL;
255
256         if (!filename) {
257                 cgit_print_error_page(400, "Bad request",
258                                 "No snapshot name specified");
259                 return;
260         }
261
262         if (ends_with(filename, ".asc")) {
263                 sig_filename = filename;
264
265                 /* Strip ".asc" from filename for common format processing */
266                 adj_filename = xstrdup(filename);
267                 adj_filename[strlen(adj_filename) - 4] = '\0';
268                 filename = adj_filename;
269         }
270
271         f = get_format(filename);
272         if (!f || (!sig_filename && !(ctx.repo->snapshots & cgit_snapshot_format_bit(f)))) {
273                 cgit_print_error_page(400, "Bad request",
274                                 "Unsupported snapshot format: %s", filename);
275                 return;
276         }
277
278         if (!hex && dwim) {
279                 hex = get_ref_from_filename(ctx.repo, filename, f);
280                 if (hex == NULL) {
281                         cgit_print_error_page(404, "Not found", "Not found");
282                         return;
283                 }
284                 prefix = xstrdup(filename);
285                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
286         }
287
288         if (!hex)
289                 hex = head;
290
291         if (!prefix)
292                 prefix = xstrdup(cgit_snapshot_prefix(ctx.repo));
293
294         if (sig_filename)
295                 write_sig(f, hex, filename, sig_filename);
296         else
297                 make_snapshot(f, hex, prefix, filename);
298
299         free(prefix);
300         free(adj_filename);
301 }