libavformat/url.h

   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 typedef struct URLContext {
  36     const AVClass *av_class;    /**< information for av_log(). Set by url_open(). */
  37     const struct URLProtocol *prot;
  38     void *priv_data;
  39     char *filename;             /**< specified URL */
  40     int flags;
  41     int max_packet_size;        /**< if non zero, the stream is packetized with this max packet size */
  42     int is_streamed;            /**< true if streamed (no seek possible), default = false */
  43     int is_connected;
  44     AVIOInterruptCB interrupt_callback;
  45     int64_t rw_timeout;         /**< maximum time to wait for (network) read/write operation completion, in mcs */
  46     const char *protocol_whitelist;
  47     const char *protocol_blacklist;
  48     int min_packet_size;        /**< if non zero, the stream is packetized with this min packet size */
  49 } URLContext;
  50
  51 typedef struct URLProtocol {
  52     const char *name;
  53     int     (*url_open)( URLContext *h, const char *url, int flags);
  54     /**
  55      * This callback is to be used by protocols which open further nested
  56      * protocols. options are then to be passed to ffurl_open_whitelist()
  57      * or ffurl_connect() for those nested protocols.
  58      */
  59     int     (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options);
  60     int     (*url_accept)(URLContext *s, URLContext **c);
  61     int     (*url_handshake)(URLContext *c);
  62
  63     /**
  64      * Read data from the protocol.
  65      * If data is immediately available (even less than size), EOF is
  66      * reached or an error occurs (including EINTR), return immediately.
  67      * Otherwise:
  68      * In non-blocking mode, return AVERROR(EAGAIN) immediately.
  69      * In blocking mode, wait for data/EOF/error with a short timeout (0.1s),
  70      * and return AVERROR(EAGAIN) on timeout.
  71      * Checking interrupt_callback, looping on EINTR and EAGAIN and until
  72      * enough data has been read is left to the calling function; see
  73      * retry_transfer_wrapper in avio.c.
  74      */
  75     int     (*url_read)( URLContext *h, unsigned char *buf, int size);
  76     int     (*url_write)(URLContext *h, const unsigned char *buf, int size);
  77     int64_t (*url_seek)( URLContext *h, int64_t pos, int whence);
  78     int     (*url_close)(URLContext *h);
  79     int (*url_read_pause)(void *urlcontext, int pause);
  80     int64_t (*url_read_seek)(void *urlcontext, int stream_index,
  81                              int64_t timestamp, int flags);
  82     int (*url_get_file_handle)(URLContext *h);
  83     int (*url_get_multi_file_handle)(URLContext *h, int **handles,
  84                                      int *numhandles);
  85     int (*url_get_short_seek)(URLContext *h);
  86     int (*url_shutdown)(URLContext *h, int flags);
  87     const AVClass *priv_data_class;
  88     int priv_data_size;
  89     int flags;
  90     int (*url_check)(URLContext *h, int mask);
  91     int (*url_open_dir)(URLContext *h);
  92     int (*url_read_dir)(URLContext *h, AVIODirEntry **next);
  93     int (*url_close_dir)(URLContext *h);
  94     int (*url_delete)(URLContext *h);
  95     int (*url_move)(URLContext *h_src, URLContext *h_dst);
  96     const char *default_whitelist;
  97 } URLProtocol;
  98
  99 /**
 100  * Create a URLContext for accessing to the resource indicated by
 101  * url, but do not initiate the connection yet.
 102  *
 103  * @param puc pointer to the location where, in case of success, the
 104  * function puts the pointer to the created URLContext
 105  * @param flags flags which control how the resource indicated by url
 106  * is to be opened
 107  * @param int_cb interrupt callback to use for the URLContext, may be
 108  * NULL
 109  * @return >= 0 in case of success, a negative value corresponding to an
 110  * AVERROR code in case of failure
 111  */
 112 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
 113                 const AVIOInterruptCB *int_cb);
 114
 115 /**
 116  * Connect an URLContext that has been allocated by ffurl_alloc
 117  *
 118  * @param options  A dictionary filled with options for nested protocols,
 119  * i.e. it will be passed to url_open2() for protocols implementing it.
 120  * This parameter will be destroyed and replaced with a dict containing options
 121  * that were not found. May be NULL.
 122  */
 123 int ffurl_connect(URLContext *uc, AVDictionary **options);
 124
 125 /**
 126  * Create an URLContext for accessing to the resource indicated by
 127  * url, and open it.
 128  *
 129  * @param puc pointer to the location where, in case of success, the
 130  * function puts the pointer to the created URLContext
 131  * @param flags flags which control how the resource indicated by url
 132  * is to be opened
 133  * @param int_cb interrupt callback to use for the URLContext, may be
 134  * NULL
 135  * @param options  A dictionary filled with protocol-private options. On return
 136  * this parameter will be destroyed and replaced with a dict containing options
 137  * that were not found. May be NULL.
 138  * @param parent An enclosing URLContext, whose generic options should
 139  *               be applied to this URLContext as well.
 140  * @return >= 0 in case of success, a negative value corresponding to an
 141  * AVERROR code in case of failure
 142  */
 143 int ffurl_open_whitelist(URLContext **puc, const char *filename, int flags,
 144                const AVIOInterruptCB *int_cb, AVDictionary **options,
 145                const char *whitelist, const char* blacklist,
 146                URLContext *parent);
 147
 148 /**
 149  * Accept an URLContext c on an URLContext s
 150  *
 151  * @param  s server context
 152  * @param  c client context, must be unallocated.
 153  * @return >= 0 on success, ff_neterrno() on failure.
 154  */
 155 int ffurl_accept(URLContext *s, URLContext **c);
 156
 157 /**
 158  * Perform one step of the protocol handshake to accept a new client.
 159  * See avio_handshake() for details.
 160  * Implementations should try to return decreasing values.
 161  * If the protocol uses an underlying protocol, the underlying handshake is
 162  * usually the first step, and the return value can be:
 163  * (largest value for this protocol) + (return value from other protocol)
 164  *
 165  * @param  c the client context
 166  * @return >= 0 on success or a negative value corresponding
 167  *         to an AVERROR code on failure
 168  */
 169 int ffurl_handshake(URLContext *c);
 170
 171 int ffurl_read2(void *urlcontext, uint8_t *buf, int size);
 172 /**
 173  * Read up to size bytes from the resource accessed by h, and store
 174  * the read bytes in buf.
 175  *
 176  * @return The number of bytes actually read, or a negative value
 177  * corresponding to an AVERROR code in case of error. A value of zero
 178  * indicates that it is not possible to read more from the accessed
 179  * resource (except if the value of the size argument is also zero).
 180  */
 181 static inline int ffurl_read(URLContext *h, uint8_t *buf, int size)
 182 {
 183     return ffurl_read2(h, buf, size);
 184 }
 185
 186 /**
 187  * Read as many bytes as possible (up to size), calling the
 188  * read function multiple times if necessary.
 189  * This makes special short-read handling in applications
 190  * unnecessary, if the return value is < size then it is
 191  * certain there was either an error or the end of file was reached.
 192  */
 193 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
 194
 195 int ffurl_write2(void *urlcontext, const uint8_t *buf, int size);
 196 /**
 197  * Write size bytes from buf to the resource accessed by h.
 198  *
 199  * @return the number of bytes actually written, or a negative value
 200  * corresponding to an AVERROR code in case of failure
 201  */
 202 static inline int ffurl_write(URLContext *h, const uint8_t *buf, int size)
 203 {
 204     return ffurl_write2(h, buf, size);
 205 }
 206
 207 int64_t ffurl_seek2(void *urlcontext, int64_t pos, int whence);
 208 /**
 209  * Change the position that will be used by the next read/write
 210  * operation on the resource accessed by h.
 211  *
 212  * @param pos specifies the new position to set
 213  * @param whence specifies how pos should be interpreted, it must be
 214  * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
 215  * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
 216  * (return the filesize of the requested resource, pos is ignored).
 217  * @return a negative value corresponding to an AVERROR code in case
 218  * of failure, or the resulting file position, measured in bytes from
 219  * the beginning of the file. You can use this feature together with
 220  * SEEK_CUR to read the current file position.
 221  */
 222 static inline int64_t ffurl_seek(URLContext *h, int64_t pos, int whence)
 223 {
 224     return ffurl_seek2(h, pos, whence);
 225 }
 226
 227 /**
 228  * Close the resource accessed by the URLContext h, and free the
 229  * memory used by it. Also set the URLContext pointer to NULL.
 230  *
 231  * @return a negative value if an error condition occurred, 0
 232  * otherwise
 233  */
 234 int ffurl_closep(URLContext **h);
 235 int ffurl_close(URLContext *h);
 236
 237 /**
 238  * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
 239  * if the operation is not supported by h, or another negative value
 240  * corresponding to an AVERROR error code in case of failure.
 241  */
 242 int64_t ffurl_size(URLContext *h);
 243
 244 /**
 245  * Return the file descriptor associated with this URL. For RTP, this
 246  * will return only the RTP file descriptor, not the RTCP file descriptor.
 247  *
 248  * @return the file descriptor associated with this URL, or <0 on error.
 249  */
 250 int ffurl_get_file_handle(URLContext *h);
 251
 252 /**
 253  * Return the file descriptors associated with this URL.
 254  *
 255  * @return 0 on success or <0 on error.
 256  */
 257 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
 258
 259 /**
 260  * Return the current short seek threshold value for this URL.
 261  *
 262  * @return threshold (>0) on success or <=0 on error.
 263  */
 264 int ffurl_get_short_seek(void *urlcontext);
 265
 266 /**
 267  * Signal the URLContext that we are done reading or writing the stream.
 268  *
 269  * @param h pointer to the resource
 270  * @param flags flags which control how the resource indicated by url
 271  * is to be shutdown
 272  *
 273  * @return a negative value if an error condition occurred, 0
 274  * otherwise
 275  */
 276 int ffurl_shutdown(URLContext *h, int flags);
 277
 278 /**
 279  * Check if the user has requested to interrupt a blocking function
 280  * associated with cb.
 281  */
 282 int ff_check_interrupt(AVIOInterruptCB *cb);
 283
 284 /* udp.c */
 285 int ff_udp_set_remote_url(URLContext *h, const char *uri);
 286 int ff_udp_get_local_port(URLContext *h);
 287
 288 /**
 289  * Assemble a URL string from components. This is the reverse operation
 290  * of av_url_split.
 291  *
 292  * Note, this requires networking to be initialized, so the caller must
 293  * ensure ff_network_init has been called.
 294  *
 295  * @see av_url_split
 296  *
 297  * @param str the buffer to fill with the url
 298  * @param size the size of the str buffer
 299  * @param proto the protocol identifier, if null, the separator
 300  *              after the identifier is left out, too
 301  * @param authorization an optional authorization string, may be null.
 302  *                      An empty string is treated the same as a null string.
 303  * @param hostname the host name string
 304  * @param port the port number, left out from the string if negative
 305  * @param fmt a generic format string for everything to add after the
 306  *            host/port, may be null
 307  * @return the number of characters written to the destination buffer
 308  */
 309 int ff_url_join(char *str, int size, const char *proto,
 310                 const char *authorization, const char *hostname,
 311                 int port, const char *fmt, ...) av_printf_format(7, 8);
 312
 313 /**
 314  * Convert a relative url into an absolute url, given a base url.
 315  *
 316  * @param buf the buffer where output absolute url is written
 317  * @param size the size of buf
 318  * @param base the base url, may be equal to buf.
 319  * @param rel the new url, which is interpreted relative to base
 320  * @param handle_dos_paths handle DOS paths for file or unspecified protocol
 321  */
 322 int ff_make_absolute_url2(char *buf, int size, const char *base,
 323                          const char *rel, int handle_dos_paths);
 324
 325 /**
 326  * Convert a relative url into an absolute url, given a base url.
 327  *
 328  * Same as ff_make_absolute_url2 with handle_dos_paths being equal to
 329  * HAVE_DOS_PATHS config variable.
 330  */
 331 int ff_make_absolute_url(char *buf, int size, const char *base,
 332                          const char *rel);
 333
 334 /**
 335  * Allocate directory entry with default values.
 336  *
 337  * @return entry or NULL on error
 338  */
 339 AVIODirEntry *ff_alloc_dir_entry(void);
 340
 341 const AVClass *ff_urlcontext_child_class_iterate(void **iter);
 342
 343 /**
 344  * Construct a list of protocols matching a given whitelist and/or blacklist.
 345  *
 346  * @param whitelist a comma-separated list of allowed protocol names or NULL. If
 347  *                  this is a non-empty string, only protocols in this list will
 348  *                  be included.
 349  * @param blacklist a comma-separated list of forbidden protocol names or NULL.
 350  *                  If this is a non-empty string, all protocols in this list
 351  *                  will be excluded.
 352  *
 353  * @return a NULL-terminated array of matching protocols. The array must be
 354  * freed by the caller.
 355  */
 356 const URLProtocol **ffurl_get_protocols(const char *whitelist,
 357                                         const char *blacklist);
 358
 359 typedef struct URLComponents {
 360     const char *url;        /**< whole URL, for reference */
 361     const char *scheme;     /**< possibly including lavf-specific options */
 362     const char *authority;  /**< "//" if it is a real URL */
 363     const char *userinfo;   /**< including final '@' if present */
 364     const char *host;
 365     const char *port;       /**< including initial ':' if present */
 366     const char *path;
 367     const char *query;      /**< including initial '?' if present */
 368     const char *fragment;   /**< including initial '#' if present */
 369     const char *end;
 370 } URLComponents;
 371
 372 #define url_component_end_scheme      authority
 373 #define url_component_end_authority   userinfo
 374 #define url_component_end_userinfo    host
 375 #define url_component_end_host        port
 376 #define url_component_end_port        path
 377 #define url_component_end_path        query
 378 #define url_component_end_query       fragment
 379 #define url_component_end_fragment    end
 380 #define url_component_end_authority_full path
 381
 382 #define URL_COMPONENT_HAVE(uc, component) \
 383     ((uc).url_component_end_##component > (uc).component)
 384
 385 /**
 386  * Parse an URL to find the components.
 387  *
 388  * Each component runs until the start of the next component,
 389  * possibly including a mandatory delimiter.
 390  *
 391  * @param uc   structure to fill with pointers to the components.
 392  * @param url  URL to parse.
 393  * @param end  end of the URL, or NULL to parse to the end of string.
 394  *
 395  * @return  >= 0 for success or an AVERROR code, especially if the URL is
 396  *          malformed.
 397  */
 398 int ff_url_decompose(URLComponents *uc, const char *url, const char *end);
 399
 400 /**
 401  * Move or rename a resource.
 402  *
 403  * @note url_src and url_dst should share the same protocol and authority.
 404  *
 405  * @param url_src url to resource to be moved
 406  * @param url_dst new url to resource if the operation succeeded
 407  * @return >=0 on success or negative on error.
 408  */
 409 int ffurl_move(const char *url_src, const char *url_dst);
 410
 411 /**
 412  * Delete a resource.
 413  *
 414  * @param url resource to be deleted.
 415  * @return >=0 on success or negative on error.
 416  */
 417 int ffurl_delete(const char *url);
 418
 419 #endif /* AVFORMAT_URL_H */