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()/ffurl_connect() 60 * 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 int priv_data_size; 91 const AVClass *priv_data_class; 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 int ffurl_open(URLContext **puc, const char *filename, int flags, 152 const AVIOInterruptCB *int_cb, AVDictionary **options); 153 154 /** 155 * Accept an URLContext c on an URLContext s 156 * 157 * @param s server context 158 * @param c client context, must be unallocated. 159 * @return >= 0 on success, ff_neterrno() on failure. 160 */ 161 int ffurl_accept(URLContext *s, URLContext **c); 162 163 /** 164 * Perform one step of the protocol handshake to accept a new client. 165 * See avio_handshake() for details. 166 * Implementations should try to return decreasing values. 167 * If the protocol uses an underlying protocol, the underlying handshake is 168 * usually the first step, and the return value can be: 169 * (largest value for this protocol) + (return value from other protocol) 170 * 171 * @param c the client context 172 * @return >= 0 on success or a negative value corresponding 173 * to an AVERROR code on failure 174 */ 175 int ffurl_handshake(URLContext *c); 176 177 /** 178 * Read up to size bytes from the resource accessed by h, and store 179 * the read bytes in buf. 180 * 181 * @return The number of bytes actually read, or a negative value 182 * corresponding to an AVERROR code in case of error. A value of zero 183 * indicates that it is not possible to read more from the accessed 184 * resource (except if the value of the size argument is also zero). 185 */ 186 int ffurl_read(URLContext *h, unsigned char *buf, int size); 187 188 /** 189 * Read as many bytes as possible (up to size), calling the 190 * read function multiple times if necessary. 191 * This makes special short-read handling in applications 192 * unnecessary, if the return value is < size then it is 193 * certain there was either an error or the end of file was reached. 194 */ 195 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size); 196 197 /** 198 * Write size bytes from buf to the resource accessed by h. 199 * 200 * @return the number of bytes actually written, or a negative value 201 * corresponding to an AVERROR code in case of failure 202 */ 203 int ffurl_write(URLContext *h, const unsigned char *buf, int size); 204 205 /** 206 * Change the position that will be used by the next read/write 207 * operation on the resource accessed by h. 208 * 209 * @param pos specifies the new position to set 210 * @param whence specifies how pos should be interpreted, it must be 211 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the 212 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE 213 * (return the filesize of the requested resource, pos is ignored). 214 * @return a negative value corresponding to an AVERROR code in case 215 * of failure, or the resulting file position, measured in bytes from 216 * the beginning of the file. You can use this feature together with 217 * SEEK_CUR to read the current file position. 218 */ 219 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence); 220 221 /** 222 * Close the resource accessed by the URLContext h, and free the 223 * memory used by it. Also set the URLContext pointer to NULL. 224 * 225 * @return a negative value if an error condition occurred, 0 226 * otherwise 227 */ 228 int ffurl_closep(URLContext **h); 229 int ffurl_close(URLContext *h); 230 231 /** 232 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS) 233 * if the operation is not supported by h, or another negative value 234 * corresponding to an AVERROR error code in case of failure. 235 */ 236 int64_t ffurl_size(URLContext *h); 237 238 /** 239 * Return the file descriptor associated with this URL. For RTP, this 240 * will return only the RTP file descriptor, not the RTCP file descriptor. 241 * 242 * @return the file descriptor associated with this URL, or <0 on error. 243 */ 244 int ffurl_get_file_handle(URLContext *h); 245 246 /** 247 * Return the file descriptors associated with this URL. 248 * 249 * @return 0 on success or <0 on error. 250 */ 251 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles); 252 253 /** 254 * Return the current short seek threshold value for this URL. 255 * 256 * @return threshold (>0) on success or <=0 on error. 257 */ 258 int ffurl_get_short_seek(URLContext *h); 259 260 /** 261 * Signal the URLContext that we are done reading or writing the stream. 262 * 263 * @param h pointer to the resource 264 * @param flags flags which control how the resource indicated by url 265 * is to be shutdown 266 * 267 * @return a negative value if an error condition occurred, 0 268 * otherwise 269 */ 270 int ffurl_shutdown(URLContext *h, int flags); 271 272 /** 273 * Check if the user has requested to interrupt a blocking function 274 * associated with cb. 275 */ 276 int ff_check_interrupt(AVIOInterruptCB *cb); 277 278 /* udp.c */ 279 int ff_udp_set_remote_url(URLContext *h, const char *uri); 280 int ff_udp_get_local_port(URLContext *h); 281 282 /** 283 * Assemble a URL string from components. This is the reverse operation 284 * of av_url_split. 285 * 286 * Note, this requires networking to be initialized, so the caller must 287 * ensure ff_network_init has been called. 288 * 289 * @see av_url_split 290 * 291 * @param str the buffer to fill with the url 292 * @param size the size of the str buffer 293 * @param proto the protocol identifier, if null, the separator 294 * after the identifier is left out, too 295 * @param authorization an optional authorization string, may be null. 296 * An empty string is treated the same as a null string. 297 * @param hostname the host name string 298 * @param port the port number, left out from the string if negative 299 * @param fmt a generic format string for everything to add after the 300 * host/port, may be null 301 * @return the number of characters written to the destination buffer 302 */ 303 int ff_url_join(char *str, int size, const char *proto, 304 const char *authorization, const char *hostname, 305 int port, const char *fmt, ...) av_printf_format(7, 8); 306 307 /** 308 * Convert a relative url into an absolute url, given a base url. 309 * 310 * @param buf the buffer where output absolute url is written 311 * @param size the size of buf 312 * @param base the base url, may be equal to buf. 313 * @param rel the new url, which is interpreted relative to base 314 */ 315 int ff_make_absolute_url(char *buf, int size, const char *base, 316 const char *rel); 317 318 /** 319 * Allocate directory entry with default values. 320 * 321 * @return entry or NULL on error 322 */ 323 AVIODirEntry *ff_alloc_dir_entry(void); 324 325 const AVClass *ff_urlcontext_child_class_next(const AVClass *prev); 326 327 /** 328 * Construct a list of protocols matching a given whitelist and/or blacklist. 329 * 330 * @param whitelist a comma-separated list of allowed protocol names or NULL. If 331 * this is a non-empty string, only protocols in this list will 332 * be included. 333 * @param blacklist a comma-separated list of forbidden protocol names or NULL. 334 * If this is a non-empty string, all protocols in this list 335 * will be excluded. 336 * 337 * @return a NULL-terminated array of matching protocols. The array must be 338 * freed by the caller. 339 */ 340 const URLProtocol **ffurl_get_protocols(const char *whitelist, 341 const char *blacklist); 342 343 typedef struct URLComponents { 344 const char *url; /**< whole URL, for reference */ 345 const char *scheme; /**< possibly including lavf-specific options */ 346 const char *authority; /**< "//" if it is a real URL */ 347 const char *userinfo; /**< including final '@' if present */ 348 const char *host; 349 const char *port; /**< including initial ':' if present */ 350 const char *path; 351 const char *query; /**< including initial '?' if present */ 352 const char *fragment; /**< including initial '#' if present */ 353 const char *end; 354 } URLComponents; 355 356 #define url_component_end_scheme authority 357 #define url_component_end_authority userinfo 358 #define url_component_end_userinfo host 359 #define url_component_end_host port 360 #define url_component_end_port path 361 #define url_component_end_path query 362 #define url_component_end_query fragment 363 #define url_component_end_fragment end 364 #define url_component_end_authority_full path 365 366 #define URL_COMPONENT_HAVE(uc, component) \ 367 ((uc).url_component_end_##component > (uc).component) 368 369 /** 370 * Parse an URL to find the components. 371 * 372 * Each component runs until the start of the next component, 373 * possibly including a mandatory delimiter. 374 * 375 * @param uc structure to fill with pointers to the components. 376 * @param url URL to parse. 377 * @param end end of the URL, or NULL to parse to the end of string. 378 * 379 * @return >= 0 for success or an AVERROR code, especially if the URL is 380 * malformed. 381 */ 382 int ff_url_decompose(URLComponents *uc, const char *url, const char *end); 383 384 #endif /* AVFORMAT_URL_H */ 385