1 /*
2 * URL utility functions
3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22
23 #include "avformat.h"
24 #include "internal.h"
25 #include "config.h"
26 #include "url.h"
27 #if CONFIG_NETWORK
28 #include "network.h"
29 #endif
30 #include "libavutil/avassert.h"
31 #include "libavutil/avstring.h"
32
33 /**
34 * @file
35 * URL utility functions.
36 */
37
ff_url_join(char * str,int size,const char * proto,const char * authorization,const char * hostname,int port,const char * fmt,...)38 int ff_url_join(char *str, int size, const char *proto,
39 const char *authorization, const char *hostname,
40 int port, const char *fmt, ...)
41 {
42 #if CONFIG_NETWORK
43 struct addrinfo hints = { 0 }, *ai;
44 #endif
45
46 str[0] = '\0';
47 if (proto)
48 av_strlcatf(str, size, "%s://", proto);
49 if (authorization && authorization[0])
50 av_strlcatf(str, size, "%s@", authorization);
51 #if CONFIG_NETWORK && defined(AF_INET6)
52 /* Determine if hostname is a numerical IPv6 address,
53 * properly escape it within [] in that case. */
54 hints.ai_flags = AI_NUMERICHOST;
55 if (!getaddrinfo(hostname, NULL, &hints, &ai)) {
56 if (ai->ai_family == AF_INET6) {
57 av_strlcat(str, "[", size);
58 av_strlcat(str, hostname, size);
59 av_strlcat(str, "]", size);
60 } else {
61 av_strlcat(str, hostname, size);
62 }
63 freeaddrinfo(ai);
64 } else
65 #endif
66 /* Not an IPv6 address, just output the plain string. */
67 av_strlcat(str, hostname, size);
68
69 if (port >= 0)
70 av_strlcatf(str, size, ":%d", port);
71 if (fmt) {
72 va_list vl;
73 size_t len = strlen(str);
74
75 va_start(vl, fmt);
76 vsnprintf(str + len, size > len ? size - len : 0, fmt, vl);
77 va_end(vl);
78 }
79 return strlen(str);
80 }
81
find_delim(const char * delim,const char * cur,const char * end)82 static const char *find_delim(const char *delim, const char *cur, const char *end)
83 {
84 while (cur < end && !strchr(delim, *cur))
85 cur++;
86 return cur;
87 }
88
ff_url_decompose(URLComponents * uc,const char * url,const char * end)89 int ff_url_decompose(URLComponents *uc, const char *url, const char *end)
90 {
91 const char *cur, *aend, *p;
92
93 av_assert0(url);
94 if (!end)
95 end = url + strlen(url);
96 cur = uc->url = url;
97
98 /* scheme */
99 uc->scheme = cur;
100 p = find_delim(":/?#", cur, end); /* lavf "schemes" can contain options but not some RFC 3986 delimiters */
101 if (*p == ':')
102 cur = p + 1;
103
104 /* authority */
105 uc->authority = cur;
106 if (end - cur >= 2 && cur[0] == '/' && cur[1] == '/') {
107 cur += 2;
108 aend = find_delim("/?#", cur, end);
109
110 /* userinfo */
111 uc->userinfo = cur;
112 p = find_delim("@", cur, aend);
113 if (*p == '@')
114 cur = p + 1;
115
116 /* host */
117 uc->host = cur;
118 if (*cur == '[') { /* hello IPv6, thanks for using colons! */
119 p = find_delim("]", cur, aend);
120 if (*p != ']')
121 return AVERROR(EINVAL);
122 if (p + 1 < aend && p[1] != ':')
123 return AVERROR(EINVAL);
124 cur = p + 1;
125 } else {
126 cur = find_delim(":", cur, aend);
127 }
128
129 /* port */
130 uc->port = cur;
131 cur = aend;
132 } else {
133 uc->userinfo = uc->host = uc->port = cur;
134 }
135
136 /* path */
137 uc->path = cur;
138 cur = find_delim("?#", cur, end);
139
140 /* query */
141 uc->query = cur;
142 if (*cur == '?')
143 cur = find_delim("#", cur, end);
144
145 /* fragment */
146 uc->fragment = cur;
147
148 uc->end = end;
149 return 0;
150 }
151
is_fq_dos_path(const char * path)152 static int is_fq_dos_path(const char *path)
153 {
154 if ((path[0] >= 'a' && path[0] <= 'z' || path[0] >= 'A' && path[0] <= 'Z') &&
155 path[1] == ':' &&
156 (path[2] == '/' || path[2] == '\\'))
157 return 1;
158 if ((path[0] == '/' || path[0] == '\\') &&
159 (path[1] == '/' || path[1] == '\\'))
160 return 1;
161 return 0;
162 }
163
append_path(char * root,char * out_end,char ** rout,const char * in,const char * in_end)164 static int append_path(char *root, char *out_end, char **rout,
165 const char *in, const char *in_end)
166 {
167 char *out = *rout;
168 const char *d, *next;
169
170 if (in < in_end && *in == '/')
171 in++; /* already taken care of */
172 while (in < in_end) {
173 d = find_delim("/", in, in_end);
174 next = d + (d < in_end && *d == '/');
175 if (d - in == 1 && in[0] == '.') {
176 /* skip */
177 } else if (d - in == 2 && in[0] == '.' && in[1] == '.') {
178 av_assert1(out[-1] == '/');
179 if (out - root > 1)
180 while (out > root && (--out)[-1] != '/');
181 } else {
182 if (out_end - out < next - in)
183 return AVERROR(ENOMEM);
184 memmove(out, in, next - in);
185 out += next - in;
186 }
187 in = next;
188 }
189 *rout = out;
190 return 0;
191 }
192
ff_make_absolute_url2(char * buf,int size,const char * base,const char * rel,int handle_dos_paths)193 int ff_make_absolute_url2(char *buf, int size, const char *base,
194 const char *rel, int handle_dos_paths)
195 {
196 URLComponents ub, uc;
197 char *out, *out_end, *path;
198 const char *keep, *base_path_end;
199 int use_base_path, simplify_path = 0, ret;
200 const char *base_separators = "/";
201
202 /* This is tricky.
203 For HTTP, http://server/site/page + ../media/file
204 should resolve into http://server/media/file
205 but for filesystem access, dir/playlist + ../media/file
206 should resolve into dir/../media/file
207 because dir could be a symlink, and .. points to
208 the actual parent of the target directory.
209
210 We'll consider that URLs with an actual scheme and authority,
211 i.e. starting with scheme://, need parent dir simplification,
212 while bare paths or pseudo-URLs starting with proto: without
213 the double slash do not.
214
215 For real URLs, the processing is similar to the algorithm described
216 here:
217 https://tools.ietf.org/html/rfc3986#section-5
218 */
219
220 if (!size)
221 return AVERROR(ENOMEM);
222 out = buf;
223 out_end = buf + size - 1;
224
225 if (!base)
226 base = "";
227 if (handle_dos_paths) {
228 if ((ret = ff_url_decompose(&ub, base, NULL)) < 0)
229 goto error;
230 if (is_fq_dos_path(base) || av_strstart(base, "file:", NULL) || ub.path == ub.url) {
231 base_separators = "/\\";
232 if (is_fq_dos_path(rel))
233 base = "";
234 }
235 }
236 if ((ret = ff_url_decompose(&ub, base, NULL)) < 0 ||
237 (ret = ff_url_decompose(&uc, rel, NULL)) < 0)
238 goto error;
239
240 keep = ub.url;
241 #define KEEP(component, also) do { \
242 if (uc.url_component_end_##component == uc.url && \
243 ub.url_component_end_##component > keep) { \
244 keep = ub.url_component_end_##component; \
245 also \
246 } \
247 } while (0)
248 KEEP(scheme, );
249 KEEP(authority_full, simplify_path = 1;);
250 KEEP(path,);
251 KEEP(query,);
252 KEEP(fragment,);
253 #undef KEEP
254 #define COPY(start, end) do { \
255 size_t len = end - start; \
256 if (len > out_end - out) { \
257 ret = AVERROR(ENOMEM); \
258 goto error; \
259 } \
260 memmove(out, start, len); \
261 out += len; \
262 } while (0)
263 COPY(ub.url, keep);
264 COPY(uc.url, uc.path);
265
266 use_base_path = URL_COMPONENT_HAVE(ub, path) && keep <= ub.path;
267 if (uc.path > uc.url)
268 use_base_path = 0;
269 if (URL_COMPONENT_HAVE(uc, path) && uc.path[0] == '/')
270 use_base_path = 0;
271 if (use_base_path) {
272 base_path_end = ub.url_component_end_path;
273 if (URL_COMPONENT_HAVE(uc, path))
274 while (base_path_end > ub.path && !strchr(base_separators, base_path_end[-1]))
275 base_path_end--;
276 }
277 if (keep > ub.path)
278 simplify_path = 0;
279 if (URL_COMPONENT_HAVE(uc, scheme))
280 simplify_path = 0;
281 if (URL_COMPONENT_HAVE(uc, authority))
282 simplify_path = 1;
283 /* No path at all, leave it */
284 if (!use_base_path && !URL_COMPONENT_HAVE(uc, path))
285 simplify_path = 0;
286
287 if (simplify_path) {
288 const char *root = "/";
289 COPY(root, root + 1);
290 path = out;
291 if (use_base_path) {
292 ret = append_path(path, out_end, &out, ub.path, base_path_end);
293 if (ret < 0)
294 goto error;
295 }
296 if (URL_COMPONENT_HAVE(uc, path)) {
297 ret = append_path(path, out_end, &out, uc.path, uc.url_component_end_path);
298 if (ret < 0)
299 goto error;
300 }
301 } else {
302 if (use_base_path)
303 COPY(ub.path, base_path_end);
304 COPY(uc.path, uc.url_component_end_path);
305 }
306
307 COPY(uc.url_component_end_path, uc.end);
308 #undef COPY
309 *out = 0;
310 return 0;
311
312 error:
313 snprintf(buf, size, "invalid:%s",
314 ret == AVERROR(ENOMEM) ? "truncated" :
315 ret == AVERROR(EINVAL) ? "syntax_error" : "");
316 return ret;
317 }
318
ff_make_absolute_url(char * buf,int size,const char * base,const char * rel)319 int ff_make_absolute_url(char *buf, int size, const char *base,
320 const char *rel)
321 {
322 return ff_make_absolute_url2(buf, size, base, rel, HAVE_DOS_PATHS);
323 }
324
ff_alloc_dir_entry(void)325 AVIODirEntry *ff_alloc_dir_entry(void)
326 {
327 AVIODirEntry *entry = av_mallocz(sizeof(AVIODirEntry));
328 if (entry) {
329 entry->type = AVIO_ENTRY_UNKNOWN;
330 entry->size = -1;
331 entry->modification_timestamp = -1;
332 entry->access_timestamp = -1;
333 entry->status_change_timestamp = -1;
334 entry->user_id = -1;
335 entry->group_id = -1;
336 entry->filemode = -1;
337 }
338 return entry;
339 }
340