1 /* 2 * This file is part of FFmpeg. 3 * 4 * FFmpeg is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Lesser General Public 6 * License as published by the Free Software Foundation; either 7 * version 2.1 of the License, or (at your option) any later version. 8 * 9 * FFmpeg is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Lesser General Public License for more details. 13 * 14 * You should have received a copy of the GNU Lesser General Public 15 * License along with FFmpeg; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 19 /** 20 * @file 21 * unbuffered private I/O API 22 */ 23 24 #ifndef AVFORMAT_URL_H 25 #define AVFORMAT_URL_H 26 27 #include "avio.h" 28 29 #include "libavutil/dict.h" 30 #include "libavutil/log.h" 31 32 #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */ 33 #define URL_PROTOCOL_FLAG_NETWORK 2 /*< The protocol uses network */ 34 35 extern const AVClass ffurl_context_class; 36 37 typedef struct URLContext { 38 const AVClass *av_class; /**< information for av_log(). Set by url_open(). */ 39 const struct URLProtocol *prot; 40 void *priv_data; 41 char *filename; /**< specified URL */ 42 int flags; 43 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */ 44 int is_streamed; /**< true if streamed (no seek possible), default = false */ 45 int is_connected; 46 AVIOInterruptCB interrupt_callback; 47 int64_t rw_timeout; /**< maximum time to wait for (network) read/write operation completion, in mcs */ 48 const char *protocol_whitelist; 49 const char *protocol_blacklist; 50 int min_packet_size; /**< if non zero, the stream is packetized with this min packet size */ 51 } URLContext; 52 53 typedef struct URLProtocol { 54 const char *name; 55 int (*url_open)( URLContext *h, const char *url, int flags); 56 /** 57 * This callback is to be used by protocols which open further nested 58 * protocols. options are then to be passed to ffurl_open_whitelist() 59 * or ffurl_connect() for those nested protocols. 60 */ 61 int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options); 62 int (*url_accept)(URLContext *s, URLContext **c); 63 int (*url_handshake)(URLContext *c); 64 65 /** 66 * Read data from the protocol. 67 * If data is immediately available (even less than size), EOF is 68 * reached or an error occurs (including EINTR), return immediately. 69 * Otherwise: 70 * In non-blocking mode, return AVERROR(EAGAIN) immediately. 71 * In blocking mode, wait for data/EOF/error with a short timeout (0.1s), 72 * and return AVERROR(EAGAIN) on timeout. 73 * Checking interrupt_callback, looping on EINTR and EAGAIN and until 74 * enough data has been read is left to the calling function; see 75 * retry_transfer_wrapper in avio.c. 76 */ 77 int (*url_read)( URLContext *h, unsigned char *buf, int size); 78 int (*url_write)(URLContext *h, const unsigned char *buf, int size); 79 int64_t (*url_seek)( URLContext *h, int64_t pos, int whence); 80 int (*url_close)(URLContext *h); 81 int (*url_read_pause)(URLContext *h, int pause); 82 int64_t (*url_read_seek)(URLContext *h, int stream_index, 83 int64_t timestamp, int flags); 84 int (*url_get_file_handle)(URLContext *h); 85 int (*url_get_multi_file_handle)(URLContext *h, int **handles, 86 int *numhandles); 87 int (*url_get_short_seek)(URLContext *h); 88 int (*url_shutdown)(URLContext *h, int flags); 89 const AVClass *priv_data_class; 90 int priv_data_size; 91 int flags; 92 int (*url_check)(URLContext *h, int mask); 93 int (*url_open_dir)(URLContext *h); 94 int (*url_read_dir)(URLContext *h, AVIODirEntry **next); 95 int (*url_close_dir)(URLContext *h); 96 int (*url_delete)(URLContext *h); 97 int (*url_move)(URLContext *h_src, URLContext *h_dst); 98 const char *default_whitelist; 99 } URLProtocol; 100 101 /** 102 * Create a URLContext for accessing to the resource indicated by 103 * url, but do not initiate the connection yet. 104 * 105 * @param puc pointer to the location where, in case of success, the 106 * function puts the pointer to the created URLContext 107 * @param flags flags which control how the resource indicated by url 108 * is to be opened 109 * @param int_cb interrupt callback to use for the URLContext, may be 110 * NULL 111 * @return >= 0 in case of success, a negative value corresponding to an 112 * AVERROR code in case of failure 113 */ 114 int ffurl_alloc(URLContext **puc, const char *filename, int flags, 115 const AVIOInterruptCB *int_cb); 116 117 /** 118 * Connect an URLContext that has been allocated by ffurl_alloc 119 * 120 * @param options A dictionary filled with options for nested protocols, 121 * i.e. it will be passed to url_open2() for protocols implementing it. 122 * This parameter will be destroyed and replaced with a dict containing options 123 * that were not found. May be NULL. 124 */ 125 int ffurl_connect(URLContext *uc, AVDictionary **options); 126 127 /** 128 * Create an URLContext for accessing to the resource indicated by 129 * url, and open it. 130 * 131 * @param puc pointer to the location where, in case of success, the 132 * function puts the pointer to the created URLContext 133 * @param flags flags which control how the resource indicated by url 134 * is to be opened 135 * @param int_cb interrupt callback to use for the URLContext, may be 136 * NULL 137 * @param options A dictionary filled with protocol-private options. On return 138 * this parameter will be destroyed and replaced with a dict containing options 139 * that were not found. May be NULL. 140 * @param parent An enclosing URLContext, whose generic options should 141 * be applied to this URLContext as well. 142 * @return >= 0 in case of success, a negative value corresponding to an 143 * AVERROR code in case of failure 144 */ 145 int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags, 146 const AVIOInterruptCB *int_cb, AVDictionary **options, 147 const char *whitelist, const char* blacklist, 148 URLContext *parent); 149 150 /** 151 * Accept an URLContext c on an URLContext s 152 * 153 * @param s server context 154 * @param c client context, must be unallocated. 155 * @return >= 0 on success, ff_neterrno() on failure. 156 */ 157 int ffurl_accept(URLContext *s, URLContext **c); 158 159 /** 160 * Perform one step of the protocol handshake to accept a new client. 161 * See avio_handshake() for details. 162 * Implementations should try to return decreasing values. 163 * If the protocol uses an underlying protocol, the underlying handshake is 164 * usually the first step, and the return value can be: 165 * (largest value for this protocol) + (return value from other protocol) 166 * 167 * @param c the client context 168 * @return >= 0 on success or a negative value corresponding 169 * to an AVERROR code on failure 170 */ 171 int ffurl_handshake(URLContext *c); 172 173 /** 174 * Read up to size bytes from the resource accessed by h, and store 175 * the read bytes in buf. 176 * 177 * @return The number of bytes actually read, or a negative value 178 * corresponding to an AVERROR code in case of error. A value of zero 179 * indicates that it is not possible to read more from the accessed 180 * resource (except if the value of the size argument is also zero). 181 */ 182 int ffurl_read(URLContext *h, unsigned char *buf, int size); 183 184 /** 185 * Read as many bytes as possible (up to size), calling the 186 * read function multiple times if necessary. 187 * This makes special short-read handling in applications 188 * unnecessary, if the return value is < size then it is 189 * certain there was either an error or the end of file was reached. 190 */ 191 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size); 192 193 /** 194 * Write size bytes from buf to the resource accessed by h. 195 * 196 * @return the number of bytes actually written, or a negative value 197 * corresponding to an AVERROR code in case of failure 198 */ 199 int ffurl_write(URLContext *h, const unsigned char *buf, int size); 200 201 /** 202 * Change the position that will be used by the next read/write 203 * operation on the resource accessed by h. 204 * 205 * @param pos specifies the new position to set 206 * @param whence specifies how pos should be interpreted, it must be 207 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the 208 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE 209 * (return the filesize of the requested resource, pos is ignored). 210 * @return a negative value corresponding to an AVERROR code in case 211 * of failure, or the resulting file position, measured in bytes from 212 * the beginning of the file. You can use this feature together with 213 * SEEK_CUR to read the current file position. 214 */ 215 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence); 216 217 /** 218 * Close the resource accessed by the URLContext h, and free the 219 * memory used by it. Also set the URLContext pointer to NULL. 220 * 221 * @return a negative value if an error condition occurred, 0 222 * otherwise 223 */ 224 int ffurl_closep(URLContext **h); 225 int ffurl_close(URLContext *h); 226 227 /** 228 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS) 229 * if the operation is not supported by h, or another negative value 230 * corresponding to an AVERROR error code in case of failure. 231 */ 232 int64_t ffurl_size(URLContext *h); 233 234 /** 235 * Return the file descriptor associated with this URL. For RTP, this 236 * will return only the RTP file descriptor, not the RTCP file descriptor. 237 * 238 * @return the file descriptor associated with this URL, or <0 on error. 239 */ 240 int ffurl_get_file_handle(URLContext *h); 241 242 /** 243 * Return the file descriptors associated with this URL. 244 * 245 * @return 0 on success or <0 on error. 246 */ 247 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles); 248 249 /** 250 * Return the current short seek threshold value for this URL. 251 * 252 * @return threshold (>0) on success or <=0 on error. 253 */ 254 int ffurl_get_short_seek(URLContext *h); 255 256 /** 257 * Signal the URLContext that we are done reading or writing the stream. 258 * 259 * @param h pointer to the resource 260 * @param flags flags which control how the resource indicated by url 261 * is to be shutdown 262 * 263 * @return a negative value if an error condition occurred, 0 264 * otherwise 265 */ 266 int ffurl_shutdown(URLContext *h, int flags); 267 268 /** 269 * Check if the user has requested to interrupt a blocking function 270 * associated with cb. 271 */ 272 int ff_check_interrupt(AVIOInterruptCB *cb); 273 274 /* udp.c */ 275 int ff_udp_set_remote_url(URLContext *h, const char *uri); 276 int ff_udp_get_local_port(URLContext *h); 277 278 /** 279 * Assemble a URL string from components. This is the reverse operation 280 * of av_url_split. 281 * 282 * Note, this requires networking to be initialized, so the caller must 283 * ensure ff_network_init has been called. 284 * 285 * @see av_url_split 286 * 287 * @param str the buffer to fill with the url 288 * @param size the size of the str buffer 289 * @param proto the protocol identifier, if null, the separator 290 * after the identifier is left out, too 291 * @param authorization an optional authorization string, may be null. 292 * An empty string is treated the same as a null string. 293 * @param hostname the host name string 294 * @param port the port number, left out from the string if negative 295 * @param fmt a generic format string for everything to add after the 296 * host/port, may be null 297 * @return the number of characters written to the destination buffer 298 */ 299 int ff_url_join(char *str, int size, const char *proto, 300 const char *authorization, const char *hostname, 301 int port, const char *fmt, ...) av_printf_format(7, 8); 302 303 /** 304 * Convert a relative url into an absolute url, given a base url. 305 * 306 * @param buf the buffer where output absolute url is written 307 * @param size the size of buf 308 * @param base the base url, may be equal to buf. 309 * @param rel the new url, which is interpreted relative to base 310 * @param handle_dos_paths handle DOS paths for file or unspecified protocol 311 */ 312 int ff_make_absolute_url2(char *buf, int size, const char *base, 313 const char *rel, int handle_dos_paths); 314 315 /** 316 * Convert a relative url into an absolute url, given a base url. 317 * 318 * Same as ff_make_absolute_url2 with handle_dos_paths being equal to 319 * HAVE_DOS_PATHS config variable. 320 */ 321 int ff_make_absolute_url(char *buf, int size, const char *base, 322 const char *rel); 323 324 /** 325 * Allocate directory entry with default values. 326 * 327 * @return entry or NULL on error 328 */ 329 AVIODirEntry *ff_alloc_dir_entry(void); 330 331 const AVClass *ff_urlcontext_child_class_iterate(void **iter); 332 333 /** 334 * Construct a list of protocols matching a given whitelist and/or blacklist. 335 * 336 * @param whitelist a comma-separated list of allowed protocol names or NULL. If 337 * this is a non-empty string, only protocols in this list will 338 * be included. 339 * @param blacklist a comma-separated list of forbidden protocol names or NULL. 340 * If this is a non-empty string, all protocols in this list 341 * will be excluded. 342 * 343 * @return a NULL-terminated array of matching protocols. The array must be 344 * freed by the caller. 345 */ 346 const URLProtocol **ffurl_get_protocols(const char *whitelist, 347 const char *blacklist); 348 349 typedef struct URLComponents { 350 const char *url; /**< whole URL, for reference */ 351 const char *scheme; /**< possibly including lavf-specific options */ 352 const char *authority; /**< "//" if it is a real URL */ 353 const char *userinfo; /**< including final '@' if present */ 354 const char *host; 355 const char *port; /**< including initial ':' if present */ 356 const char *path; 357 const char *query; /**< including initial '?' if present */ 358 const char *fragment; /**< including initial '#' if present */ 359 const char *end; 360 } URLComponents; 361 362 #define url_component_end_scheme authority 363 #define url_component_end_authority userinfo 364 #define url_component_end_userinfo host 365 #define url_component_end_host port 366 #define url_component_end_port path 367 #define url_component_end_path query 368 #define url_component_end_query fragment 369 #define url_component_end_fragment end 370 #define url_component_end_authority_full path 371 372 #define URL_COMPONENT_HAVE(uc, component) \ 373 ((uc).url_component_end_##component > (uc).component) 374 375 /** 376 * Parse an URL to find the components. 377 * 378 * Each component runs until the start of the next component, 379 * possibly including a mandatory delimiter. 380 * 381 * @param uc structure to fill with pointers to the components. 382 * @param url URL to parse. 383 * @param end end of the URL, or NULL to parse to the end of string. 384 * 385 * @return >= 0 for success or an AVERROR code, especially if the URL is 386 * malformed. 387 */ 388 int ff_url_decompose(URLComponents *uc, const char *url, const char *end); 389 390 /** 391 * Move or rename a resource. 392 * 393 * @note url_src and url_dst should share the same protocol and authority. 394 * 395 * @param url_src url to resource to be moved 396 * @param url_dst new url to resource if the operation succeeded 397 * @return >=0 on success or negative on error. 398 */ 399 int ffurl_move(const char *url_src, const char *url_dst); 400 401 /** 402 * Delete a resource. 403 * 404 * @param url resource to be deleted. 405 * @return >=0 on success or negative on error. 406 */ 407 int ffurl_delete(const char *url); 408 409 #endif /* AVFORMAT_URL_H */ 410