format_cap.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2014, Digium, Inc.
 *
 * Joshua Colp <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Format Capabilities API
 *
 * \author Joshua Colp <[email protected]>
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/logger.h"
#include "asterisk/format.h"
#include "asterisk/format_cap.h"
#include "asterisk/format_cache.h"
#include "asterisk/codec.h"
#include "asterisk/astobj2.h"
#include "asterisk/strings.h"
#include "asterisk/vector.h"
#include "asterisk/linkedlists.h"
#include "asterisk/utils.h"

/*! \brief Structure used for capability formats, adds framing */
struct format_cap_framed {
   /*! \brief A pointer to the format */
   struct ast_format *format;
   /*! \brief The format framing size */
   unsigned int framing;
   /*! \brief Linked list information */
   AST_LIST_ENTRY(format_cap_framed) entry;
};

/*! \brief Format capabilities structure, holds formats + preference order + etc */
struct ast_format_cap {
   /*! \brief Vector of formats, indexed using the codec identifier */
   AST_VECTOR(, struct format_cap_framed_list) formats;
   /*! \brief Vector of formats, added in preference order */
   AST_VECTOR(, struct format_cap_framed *) preference_order;
   /*! \brief Global framing size, applies to all formats if no framing present on format */
   unsigned int framing;
};

/*! \brief Linked list for formats */
AST_LIST_HEAD_NOLOCK(format_cap_framed_list, format_cap_framed);

/*! \brief Dummy empty list for when we are inserting a new list */
static const struct format_cap_framed_list format_cap_framed_list_empty = AST_LIST_HEAD_NOLOCK_INIT_VALUE;

/*! \brief Destructor for format capabilities structure */
static void format_cap_destroy(void *obj)
{
   struct ast_format_cap *cap = obj;
   int idx;

   for (idx = 0; idx < AST_VECTOR_SIZE(&cap->formats); idx++) {
      struct format_cap_framed_list *list = AST_VECTOR_GET_ADDR(&cap->formats, idx);
      struct format_cap_framed *framed;

      while ((framed = AST_LIST_REMOVE_HEAD(list, entry))) {
         ao2_ref(framed, -1);
      }
   }
   AST_VECTOR_FREE(&cap->formats);

   for (idx = 0; idx < AST_VECTOR_SIZE(&cap->preference_order); idx++) {
      struct format_cap_framed *framed = AST_VECTOR_GET(&cap->preference_order, idx);

      /* This will always be non-null, unlike formats */
      ao2_ref(framed, -1);
   }
   AST_VECTOR_FREE(&cap->preference_order);
}

/*
 * \brief Initialize values on an ast_format_cap
 *
 * \param cap ast_format_cap to initialize
 * \param flags Unused.
 * \retval 0 Success
 * \retval -1 Failure
 */
static inline int format_cap_init(struct ast_format_cap *cap, enum ast_format_cap_flags flags)
{
   if (AST_VECTOR_INIT(&cap->formats, 0)) {
      return -1;
   }

   /* TODO: Look at common usage of this and determine a good starting point */
   if (AST_VECTOR_INIT(&cap->preference_order, 5)) {
      return -1;
   }

   cap->framing = UINT_MAX;
   return 0;
}

struct ast_format_cap *__ast_format_cap_alloc(enum ast_format_cap_flags flags,
   const char *tag, const char *file, int line, const char *func)
{
   struct ast_format_cap *cap;

   cap = __ao2_alloc(sizeof(*cap), format_cap_destroy, AO2_ALLOC_OPT_LOCK_NOLOCK,
      tag, file, line, func);
   if (!cap) {
      return NULL;
   }

   if (format_cap_init(cap, flags)) {
      ao2_ref(cap, -1);
      return NULL;
   }

   return cap;
}

void ast_format_cap_set_framing(struct ast_format_cap *cap, unsigned int framing)
{
   cap->framing = framing;
}

/*! \brief Destructor for format capabilities framed structure */
static void format_cap_framed_destroy(void *obj)
{
   struct format_cap_framed *framed = obj;

   ao2_cleanup(framed->format);
}

static inline int format_cap_framed_init(struct format_cap_framed *framed, struct ast_format_cap *cap, struct ast_format *format, unsigned int framing)
{
   struct format_cap_framed_list *list;

   framed->framing = framing;

   if (ast_format_get_codec_id(format) >= AST_VECTOR_SIZE(&cap->formats)) {
      if (AST_VECTOR_REPLACE(&cap->formats, ast_format_get_codec_id(format), format_cap_framed_list_empty)) {
         ao2_ref(framed, -1);
         return -1;
      }
   }
   list = AST_VECTOR_GET_ADDR(&cap->formats, ast_format_get_codec_id(format));

   /* This takes the allocation reference */
   if (AST_VECTOR_APPEND(&cap->preference_order, framed)) {
      ao2_ref(framed, -1);
      return -1;
   }

   /* Order doesn't matter for formats, so insert at the head for performance reasons */
   ao2_ref(framed, +1);
   AST_LIST_INSERT_HEAD(list, framed, entry);

   cap->framing = MIN(cap->framing, framing ? framing : ast_format_get_default_ms(format));

   return 0;
}

/*! \internal \brief Determine if \c format is in \c cap */
static int format_in_format_cap(struct ast_format_cap *cap, struct ast_format *format)
{
   struct format_cap_framed *framed;
   int i;

   for (i = 0; i < AST_VECTOR_SIZE(&cap->preference_order); i++) {
      framed = AST_VECTOR_GET(&cap->preference_order, i);

      if (ast_format_get_codec_id(format) == ast_format_get_codec_id(framed->format)) {
         return 1;
      }
   }

   return 0;
}

int __ast_format_cap_append(struct ast_format_cap *cap, struct ast_format *format, unsigned int framing, const char *tag, const char *file, int line, const char *func)
{
   struct format_cap_framed *framed;

   ast_assert(format != NULL);

   if (format_in_format_cap(cap, format)) {
      return 0;
   }

   framed = ao2_alloc_options(sizeof(*framed), format_cap_framed_destroy, AO2_ALLOC_OPT_LOCK_NOLOCK);
   if (!framed) {
      return -1;
   }

   __ao2_ref(format, +1, tag, file, line, func);
   framed->format = format;

   return format_cap_framed_init(framed, cap, format, framing);
}

int ast_format_cap_append_by_type(struct ast_format_cap *cap, enum ast_media_type type)
{
   int id;

   for (id = 1; id < ast_codec_get_max(); ++id) {
      struct ast_codec *codec = ast_codec_get_by_id(id);
      struct ast_codec *codec2 = NULL;
      struct ast_format *format;
      int res;

      if (!codec) {
         continue;
      }

      if ((type != AST_MEDIA_TYPE_UNKNOWN) && codec->type != type) {
         ao2_ref(codec, -1);
         continue;
      }

      format = ast_format_cache_get_by_codec(codec);

      if (format == ast_format_none) {
         ao2_ref(format, -1);
         ao2_ref(codec, -1);
         continue;
      }

      if (format) {
         codec2 = ast_format_get_codec(format);
      }
      if (codec != codec2) {
         ao2_cleanup(format);
         format = ast_format_create(codec);
      }
      ao2_cleanup(codec2);
      ao2_ref(codec, -1);

      if (!format) {
         return -1;
      }

      /* Use the global framing or default framing of the codec */
      res = ast_format_cap_append(cap, format, 0);
      ao2_ref(format, -1);

      if (res) {
         return -1;
      }
   }

   return 0;
}

int ast_format_cap_append_from_cap(struct ast_format_cap *dst, const struct ast_format_cap *src,
   enum ast_media_type type)
{
   int idx, res = 0;

   /* NOTE:  The streams API is dependent on the formats being in "preference" order */
   for (idx = 0; (idx < AST_VECTOR_SIZE(&src->preference_order)) && !res; ++idx) {
      struct format_cap_framed *framed = AST_VECTOR_GET(&src->preference_order, idx);

      if (type == AST_MEDIA_TYPE_UNKNOWN || ast_format_get_type(framed->format) == type) {
         res = ast_format_cap_append(dst, framed->format, framed->framing);
      }
   }

   return res;
}

static int format_cap_replace(struct ast_format_cap *cap, struct ast_format *format, unsigned int framing)
{
   struct format_cap_framed *framed;
   int i;

   ast_assert(format != NULL);

   for (i = 0; i < AST_VECTOR_SIZE(&cap->preference_order); i++) {
      framed = AST_VECTOR_GET(&cap->preference_order, i);

      if (ast_format_get_codec_id(format) == ast_format_get_codec_id(framed->format)) {
         ao2_t_replace(framed->format, format, "replacing with new format");
         framed->framing = framing;
         return 0;
      }
   }

   return -1;
}

void ast_format_cap_replace_from_cap(struct ast_format_cap *dst, const struct ast_format_cap *src,
   enum ast_media_type type)
{
   int idx;

   for (idx = 0; (idx < AST_VECTOR_SIZE(&src->preference_order)); ++idx) {
      struct format_cap_framed *framed = AST_VECTOR_GET(&src->preference_order, idx);

      if (type == AST_MEDIA_TYPE_UNKNOWN || ast_format_get_type(framed->format) == type) {
         format_cap_replace(dst, framed->format, framed->framing);
      }
   }
}

int ast_format_cap_update_by_allow_disallow(struct ast_format_cap *cap, const char *list, int allowing)
{
   int res = 0, all = 0, iter_allowing;
   char *parse = NULL, *this = NULL, *psize = NULL;

   if (!allowing && ast_strlen_zero(list)) {
      return 0;
   }

   parse = ast_strdupa(list);

   /* If the list is being fed to us as a result of ast_format_cap_get_names,
    * strip off the parenthesis and immediately apply the inverse of the
    * allowing option
    */
   if (parse[0] == '(' && parse[strlen(parse) - 1] == ')') {
      parse++;
      parse[strlen(parse) - 1] = '\0';

      if (allowing) {
         ast_format_cap_remove_by_type(cap, AST_MEDIA_TYPE_UNKNOWN);
      } else {
         ast_format_cap_append_by_type(cap, AST_MEDIA_TYPE_UNKNOWN);
      }
   }


   while ((this = ast_strip(strsep(&parse, ",|")))) {
      int framems = 0;
      struct ast_format *format = NULL;

      iter_allowing = allowing;
      if (*this == '!') {
         this++;
         iter_allowing = !allowing;
      }
      if ((psize = strrchr(this, ':'))) {
         *psize++ = '\0';
         ast_debug(1, "Packetization for codec: %s is %s\n", this, psize);
         if (!sscanf(psize, "%30d", &framems) || (framems < 0)) {
            framems = 0;
            res = -1;
            ast_log(LOG_WARNING, "Bad packetization value for codec %s\n", this);
            continue;
         }
      }
      all = strcasecmp(this, "all") ? 0 : 1;

      if (!all && !(format = ast_format_cache_get(this))) {
         ast_log(LOG_WARNING, "Cannot %s unknown format '%s'\n", iter_allowing ? "allow" : "disallow", this);
         res = -1;
         continue;
      }

      if (cap) {
         if (iter_allowing) {
            if (all) {
               ast_format_cap_append_by_type(cap, AST_MEDIA_TYPE_UNKNOWN);
            } else {
               ast_format_cap_append(cap, format, framems);
            }
         } else {
            if (all) {
               ast_format_cap_remove_by_type(cap, AST_MEDIA_TYPE_UNKNOWN);
            } else {
               ast_format_cap_remove(cap, format);
            }
         }
      }

      ao2_cleanup(format);
   }
   return res;
}

size_t ast_format_cap_count(const struct ast_format_cap *cap)
{
   return AST_VECTOR_SIZE(&cap->preference_order);
}

struct ast_format *ast_format_cap_get_format(const struct ast_format_cap *cap, int position)
{
   struct format_cap_framed *framed;

   ast_assert(position < AST_VECTOR_SIZE(&cap->preference_order));

   if (position >= AST_VECTOR_SIZE(&cap->preference_order)) {
      return NULL;
   }

   framed = AST_VECTOR_GET(&cap->preference_order, position);

   ast_assert(framed->format != ast_format_none);
   ao2_ref(framed->format, +1);
   return framed->format;
}

struct ast_format *ast_format_cap_get_best_by_type(const struct ast_format_cap *cap, enum ast_media_type type)
{
   int i;

   if (type == AST_MEDIA_TYPE_UNKNOWN) {
      return ast_format_cap_get_format(cap, 0);
   }

   for (i = 0; i < AST_VECTOR_SIZE(&cap->preference_order); i++) {
      struct format_cap_framed *framed = AST_VECTOR_GET(&cap->preference_order, i);

      if (ast_format_get_type(framed->format) == type) {
         ao2_ref(framed->format, +1);
         ast_assert(framed->format != ast_format_none);
         return framed->format;
      }
   }

   return NULL;
}

unsigned int ast_format_cap_get_framing(const struct ast_format_cap *cap)
{
   return (cap->framing != UINT_MAX) ? cap->framing : 0;
}

unsigned int ast_format_cap_get_format_framing(const struct ast_format_cap *cap, const struct ast_format *format)
{
   unsigned int framing;
   struct format_cap_framed_list *list;
   struct format_cap_framed *framed, *result = NULL;

   if (ast_format_get_codec_id(format) >= AST_VECTOR_SIZE(&cap->formats)) {
      return 0;
   }

   framing = cap->framing != UINT_MAX ? cap->framing : ast_format_get_default_ms(format);
   list = AST_VECTOR_GET_ADDR(&cap->formats, ast_format_get_codec_id(format));

   AST_LIST_TRAVERSE(list, framed, entry) {
      enum ast_format_cmp_res res = ast_format_cmp(format, framed->format);

      if (res == AST_FORMAT_CMP_NOT_EQUAL) {
         continue;
      }

      result = framed;

      if (res == AST_FORMAT_CMP_EQUAL) {
         break;
      }
   }

   if (result && result->framing) {
      framing = result->framing;
   }

   return framing;
}

/*!
 * \brief format_cap_framed comparator for AST_VECTOR_REMOVE_CMP_ORDERED()
 *
 * \param elem Element to compare against
 * \param value Value to compare with the vector element.
 *
 * \return 0 if element does not match.
 * \return Non-zero if element matches.
 */
#define FORMAT_CAP_FRAMED_ELEM_CMP(elem, value) ((elem)->format == (value))

/*!
 * \brief format_cap_framed vector element cleanup.
 *
 * \param elem Element to cleanup
 *
 * \return Nothing
 */
#define FORMAT_CAP_FRAMED_ELEM_CLEANUP(elem)  ao2_cleanup((elem))

int ast_format_cap_remove(struct ast_format_cap *cap, struct ast_format *format)
{
   struct format_cap_framed_list *list;
   struct format_cap_framed *framed;

   ast_assert(format != NULL);

   if (ast_format_get_codec_id(format) >= AST_VECTOR_SIZE(&cap->formats)) {
      return -1;
   }

   list = AST_VECTOR_GET_ADDR(&cap->formats, ast_format_get_codec_id(format));

   AST_LIST_TRAVERSE_SAFE_BEGIN(list, framed, entry) {
      if (!FORMAT_CAP_FRAMED_ELEM_CMP(framed, format)) {
         continue;
      }

      AST_LIST_REMOVE_CURRENT(entry);
      FORMAT_CAP_FRAMED_ELEM_CLEANUP(framed);
      break;
   }
   AST_LIST_TRAVERSE_SAFE_END;

   return AST_VECTOR_REMOVE_CMP_ORDERED(&cap->preference_order, format,
      FORMAT_CAP_FRAMED_ELEM_CMP, FORMAT_CAP_FRAMED_ELEM_CLEANUP);
}

void ast_format_cap_remove_by_type(struct ast_format_cap *cap, enum ast_media_type type)
{
   int idx;

   for (idx = 0; idx < AST_VECTOR_SIZE(&cap->formats); ++idx) {
      struct format_cap_framed_list *list = AST_VECTOR_GET_ADDR(&cap->formats, idx);
      struct format_cap_framed *framed;

      AST_LIST_TRAVERSE_SAFE_BEGIN(list, framed, entry) {
         if ((type != AST_MEDIA_TYPE_UNKNOWN) &&
            ast_format_get_type(framed->format) != type) {
            continue;
         }

         AST_LIST_REMOVE_CURRENT(entry);
         AST_VECTOR_REMOVE_CMP_ORDERED(&cap->preference_order, framed->format,
            FORMAT_CAP_FRAMED_ELEM_CMP, FORMAT_CAP_FRAMED_ELEM_CLEANUP);
         ao2_ref(framed, -1);
      }
      AST_LIST_TRAVERSE_SAFE_END;
   }
}

struct ast_format *ast_format_cap_get_compatible_format(const struct ast_format_cap *cap, const struct ast_format *format)
{
   struct format_cap_framed_list *list;
   struct format_cap_framed *framed;
   struct ast_format *result = NULL;

   ast_assert(format != NULL);

   if (ast_format_get_codec_id(format) >= AST_VECTOR_SIZE(&cap->formats)) {
      return NULL;
   }

   list = AST_VECTOR_GET_ADDR(&cap->formats, ast_format_get_codec_id(format));

   AST_LIST_TRAVERSE(list, framed, entry) {
      enum ast_format_cmp_res res = ast_format_cmp(format, framed->format);

      if (res == AST_FORMAT_CMP_NOT_EQUAL) {
         continue;
      }

      /* Replace any current result, this one will also be a subset OR an exact match */
      ao2_cleanup(result);

      result = ast_format_joint(format, framed->format);

      /* If it's a match we can do no better so return asap */
      if (res == AST_FORMAT_CMP_EQUAL) {
         break;
      }
   }

   return result;
}

enum ast_format_cmp_res ast_format_cap_iscompatible_format(const struct ast_format_cap *cap,
   const struct ast_format *format)
{
   enum ast_format_cmp_res res = AST_FORMAT_CMP_NOT_EQUAL;
   struct format_cap_framed_list *list;
   struct format_cap_framed *framed;

   ast_assert(format != NULL);

   if (ast_format_get_codec_id(format) >= AST_VECTOR_SIZE(&cap->formats)) {
      return AST_FORMAT_CMP_NOT_EQUAL;
   }

   list = AST_VECTOR_GET_ADDR(&cap->formats, ast_format_get_codec_id(format));

   AST_LIST_TRAVERSE(list, framed, entry) {
      enum ast_format_cmp_res cmp = ast_format_cmp(format, framed->format);

      if (cmp == AST_FORMAT_CMP_NOT_EQUAL) {
         continue;
      }

      res = cmp;

      if (res == AST_FORMAT_CMP_EQUAL) {
         break;
      }
   }

   return res;
}

int ast_format_cap_has_type(const struct ast_format_cap *cap, enum ast_media_type type)
{
   int idx;

   for (idx = 0; idx < AST_VECTOR_SIZE(&cap->preference_order); ++idx) {
      struct format_cap_framed *framed = AST_VECTOR_GET(&cap->preference_order, idx);

      if (ast_format_get_type(framed->format) == type) {
         return 1;
      }
   }

   return 0;
}

int ast_format_cap_get_compatible(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2,
   struct ast_format_cap *result)
{
   int idx, res = 0;

   for (idx = 0; idx < AST_VECTOR_SIZE(&cap1->preference_order); ++idx) {
      struct format_cap_framed *framed = AST_VECTOR_GET(&cap1->preference_order, idx);
      struct ast_format *format;

      format = ast_format_cap_get_compatible_format(cap2, framed->format);
      if (!format) {
         continue;
      }

      res = ast_format_cap_append(result, format, framed->framing);
      ao2_ref(format, -1);

      if (res) {
         break;
      }
   }

   return res;
}

int ast_format_cap_iscompatible(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2)
{
   int idx;

   for (idx = 0; idx < AST_VECTOR_SIZE(&cap1->preference_order); ++idx) {
      struct format_cap_framed *framed = AST_VECTOR_GET(&cap1->preference_order, idx);

      if (ast_format_cap_iscompatible_format(cap2, framed->format) != AST_FORMAT_CMP_NOT_EQUAL) {
         return 1;
      }
   }

   return 0;
}

static int internal_format_cap_identical(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2)
{
   int idx;
   struct ast_format *tmp;

   for (idx = 0; idx < AST_VECTOR_SIZE(&cap1->preference_order); ++idx) {
      tmp = ast_format_cap_get_format(cap1, idx);

      if (ast_format_cap_iscompatible_format(cap2, tmp) != AST_FORMAT_CMP_EQUAL) {
         ao2_ref(tmp, -1);
         return 0;
      }

      ao2_ref(tmp, -1);
   }

   return 1;
}

int ast_format_cap_identical(const struct ast_format_cap *cap1, const struct ast_format_cap *cap2)
{
   if (AST_VECTOR_SIZE(&cap1->preference_order) != AST_VECTOR_SIZE(&cap2->preference_order)) {
      return 0; /* if they are not the same size, they are not identical */
   }

   if (!internal_format_cap_identical(cap1, cap2)) {
      return 0;
   }

   return internal_format_cap_identical(cap2, cap1);
}

static const char *__ast_format_cap_get_names(const struct ast_format_cap *cap, struct ast_str **buf, int append)
{
   int i;

   if (!buf || !*buf) {
      return "";
   }

   if (append) {
      ast_str_append(buf, 0, "(");
   } else {
      ast_str_set(buf, 0, "(");
   }

   if (!cap || !AST_VECTOR_SIZE(&cap->preference_order)) {
      ast_str_append(buf, 0, "nothing)");
      return ast_str_buffer(*buf);
   }

   for (i = 0; i < AST_VECTOR_SIZE(&cap->preference_order); ++i) {
      int res;
      struct format_cap_framed *framed = AST_VECTOR_GET(&cap->preference_order, i);

      res = ast_str_append(buf, 0, "%s%s", ast_format_get_name(framed->format),
         i < AST_VECTOR_SIZE(&cap->preference_order) - 1 ? "|" : "");
      if (res < 0) {
         break;
      }
   }
   ast_str_append(buf, 0, ")");

   return ast_str_buffer(*buf);
}

const char *ast_format_cap_get_names(const struct ast_format_cap *cap, struct ast_str **buf)
{
   return __ast_format_cap_get_names(cap, buf, 0);
}

const char *ast_format_cap_append_names(const struct ast_format_cap *cap, struct ast_str **buf)
{
   return __ast_format_cap_get_names(cap, buf, 1);
}

int ast_format_cap_empty(const struct ast_format_cap *cap)
{
   int count = ast_format_cap_count(cap);

   if (count > 1) {
      return 0;
   }

   if (count == 0 || AST_VECTOR_GET(&cap->preference_order, 0)->format == ast_format_none) {
      return 1;
   }

   return 0;
}