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