url.c

Sofia SIP is an open-source SIP User-Agent library, compliant with the IETF RFC3261 specification.

/** 
 * Duplicate the url.
 * 
 * The function url_dup() copies the url structure @a src and the strings
 * attached to it to @a url.  The non-constant strings in @a src are copied
 * to @a buf.  If the size of duplicated strings exceed @a bufsize, the 
 * corresponding string fields in @a url are set to NULL.
 *
 * The calling function can calculate the size of buffer required by calling
 * url_dup() with zero as @a bufsize and NULL as @a dst.

 * @param buf     Buffer for non-constant strings copied from @a src.
 * @param bufsize Size of @a buf.
 * @param dst     Destination URL structure.
 *燖param src     Source URL structure.
 *
 * @return Number of characters required for
 * duplicating the strings in @a str, or -1 if an error
 * occurred.
 */
issize_t url_dup(char *buf, isize_t bufsize, url_t *dst, url_t const *src)
{
  if (!src && !dst)
    return -1;
  else if (URL_STRING_P(src)) {
    size_t n = strlen((char *)src) + 1;
    if (n > bufsize || dst == NULL)
      return n;

    strcpy(buf, (char *)src);
    memset(dst, 0, sizeof(*dst));
    if (url_d(dst, buf) < 0)
      return -1;

    return n;
  }
  else {
    char *b = buf;
    char *end = b + bufsize;
    char const **dstp; 
    char const * const *srcp;
    url_t dst0[1];

    if (dst == NULL)
      dst = dst0;

    memset(dst, 0, sizeof(*dst));

    if (!src)
      return 0;

    memset(dst->url_pad, 0, sizeof dst->url_pad);
    dst->url_type = src->url_type;
    dst->url_root = src->url_root;

    dstp = &dst->url_scheme;
    srcp = &src->url_scheme;

    if (dst->url_type > url_unknown)
      *dstp = url_scheme(dst->url_type);

    if (*dstp != NULL)
      dstp++, srcp++;	/* Skip scheme if it is constant */

    if (dst != dst0 && buf != NULL && bufsize != 0)
      for (; srcp <= &src->url_fragment; srcp++, dstp++)
	if (*srcp) {
	  char *next = copy(b, end, *srcp);

	  if (next > end)
	    break;

	  *dstp = b, b = next;
	}

    for (; srcp <= &src->url_fragment; srcp++)
      if (*srcp) {
	b += strlen(*srcp) + 1;
      }

    return b - buf;
  }
}

/**@def URL_DUP(buf, end, dst, src)
 *  Duplicate the url: use @a buf up to @a end. @HI 
 *
 * The macro URL_DUP() duplicates the url.  The non-constant strings in @a
 * src are copied to @a buf.  However, no strings are copied past @a end.
 * In other words, the size of buffer is @a end - @a buf.
 *
 * The macro updates the buffer pointer @a buf, so that it points to the
 * first unused byte in the buffer.  The buffer pointer @a buf is updated,
 * even if the buffer is too small for the duplicated strings.
 *
 * @param buf     Buffer for non-constant strings copied from @a src.
 * @param end     End of @a buf.
 * @param dst     Destination URL structure.
 *燖param src     Source URL structure.
 *
 * @return 
 * The macro URL_DUP() returns pointer to first unused byte in the 
 * buffer @a buf.
 */

/** Duplicate the url to memory allocated via home.
 *
 * The function url_hdup() duplicates (deep copies) an #url_t structure. 
 * Alternatively, it can be passed a string; string is then copied and
 * parsed to the #url_t structure.
 *
 * The function url_hdup() allocates the destination structure from @a home
 * as a single memory block. It is possible to free the copied url structure
 * and all the associated strings using a single call to su_free().
 *
 * @param home memory home used to allocate new url object
 * @param src  pointer to URL (or string)
 *
 * @return
 * The function url_hdup() returns a pointer to the newly allocated #url_t
 * structure, or NULL upon an error.
 */ 
url_t *url_hdup(su_home_t *home, url_t const *src)
{
  if (src) {
    size_t len = sizeof(*src) + url_xtra(src);
    url_t *dst = su_alloc(home, len);
    if (dst) {
      ssize_t actual;
      actual = url_dup((char *)(dst + 1), len - sizeof(*src), dst, src);
      if (actual < 0)
	su_free(home, dst), dst = NULL;
      else
	assert(len == sizeof(*src) + actual);
    }
    return dst;
  }
  else
    return NULL;
}


/** Convert an string to an url */ 
url_t *url_make(su_home_t *h, char const *str)
{
  return url_hdup(h, URL_STRING_MAKE(str)->us_url);
}

/** Print an URL */ 
url_t *url_format(su_home_t *h, char const *fmt, ...)
{
  url_t *url;
  char *us;
  va_list ap;

  va_start(ap, fmt);

  us = su_vsprintf(h, fmt, ap);

  va_end(ap);

  if (us == NULL)
    return NULL;

  url = url_hdup(h, URL_STRING_MAKE(us)->us_url);

  su_free(h, us);

  return url;
}


/** Convert @a url to a string allocated from @a home.
 *
 * @param home memory home to allocate the new string
 * @param url  url to convert to string
 *
 * The @a url can be a string, too.
 *
 * @return Newly allocated conversion result, or NULL upon an error.
 */
char *url_as_string(su_home_t *home, url_t const *url)
{
  if (url) {
    int len = url_e(NULL, 0, url);
    char *b = su_alloc(home, len + 1);
    url_e(b, len + 1, url);
    return b;
  } else {
    return NULL;
  }
}


/** Test if param @a tag matches to parameter string @a p. 
 */
#define URL_PARAM_MATCH(p, tag) \
 (strncasecmp(p, tag, strlen(tag)) == 0 && \
  (p[strlen(tag)] == '\0' || p[strlen(tag)] == ';' || p[strlen(tag)] == '='))

/**
 * Search for a parameter.
 *
 * This function searches for a parameter from a parameter list.
 *
 * If you want to test if there is parameter @b user=phone, 
 * call this function like 
 * @code if (url_param(url->url_param, "user=phone", NULL, 0))
 * @endcode
 *
 * @param params URL parameter string (excluding first semicolon)
 * @param tag    parameter name
 * @param value  string to which the parameter value is copied
 * @param vlen   length of string reserved for value
 *
 * @retval positive length of parameter value (including final NUL) if found
 * @retval zero     if not found.
 */
isize_t url_param(char const *params, 
		  char const *tag, 
		  char value[], isize_t vlen)
{
  size_t n, tlen, flen;
  char *p;

  if (!params)
    return 0;

  tlen = strlen(tag);
  if (tlen && tag[tlen - 1] == '=')
    tlen--;

  for (p = (char *)params; *p; p += n + 1) {
    n = strcspn(p, ";");
    if (n < tlen) {
      if (p[n]) continue; else break;
    }
    if (strncasecmp(p, tag, tlen) == 0) {
      if (n == tlen) {
	if (vlen > 0)
	  value[0] = '\0';	
	return 1;
      }
      if (p[tlen] != '=')
	continue;
      flen = n - tlen - 1;
      if (flen >= (size_t)vlen)
	return flen + 1;
      memcpy(value, p + tlen + 1, flen);
      value[flen] = '\0';
      return flen + 1;
    }
    if (!p[n])
      break;
  }

  return 0;
}

/** Check for a parameter. 
 *
 * @deprecated 
 * Bad grammar. Use url_has_param().
 */
isize_t url_have_param(char const *params, char const *tag)
{
  return url_param(params, tag, NULL, 0);
}

/** Check for a parameter. */
int url_has_param(url_t const *url, char const *tag)
{
  return url && url->url_params && url_param(url->url_params, tag, NULL, 0);
}

/** Add an parameter. */
int url_param_add(su_home_t *h, url_t *url, char const *param)
{
  /* XXX - should remove existing parameters with same name? */
  size_t n = url->url_params ? strlen(url->url_params) + 1: 0;
  size_t nn = strlen(param) + 1;
  char *s = su_alloc(h, n + nn);

  if (!s)
    return -1;
  
  if (url->url_params)
    strcpy(s, url->url_params)[n - 1] = ';';
  strcpy(s + n, param);
  url->url_params = s;

  return 0;
}

/** Remove a named parameter from url_param string.
 *
 * Remove a named parameter and its possible value from the URL parameter
 * string (url_s##url_param).
 *
 * @return Pointer to modified string, or NULL if nothing is left in there.
 */
char *url_strip_param_string(char *params, char const *name)
{
  if (params && name) {
    size_t i, n = strlen(name), remove, rest;
    
    for (i = 0; params[i];) {
      if (strncasecmp(params + i, name, n) ||
	  (params[i + n] != '=' && params[i + n] != ';' && params[i + n])) {
	i = i + strcspn(params + i, ";");
	if (!params[i++])
	  break;
	continue;
      }
      remove = n + strcspn(params + i + n, ";");
      if (params[i + remove] == ';')
	remove++;

      if (i == 0) {
	params += remove;
	continue;
      }

      rest = strlen(params + i + remove);
      if (!rest) {
	if (i == 0)
	  return NULL;		/* removed everything */
	params[i - 1] = '\0';
	break;
      }
      memmove(params + i, params + i + remove, rest + 1);
    }

    if (!params[0])
      return NULL;
  }

  return params;
}

int url_string_p(url_string_t const *url)
{
  return URL_STRING_P(url);
}

int url_is_string(url_string_t const *url)
{
  return URL_IS_STRING(url);
}

/** Strip transport-specific stuff. */
static
int url_strip_transport2(url_t *url, int modify)
{
  char *p, *d;
  size_t n;
  int semi;

  if (url->url_type != url_sip && url->url_type != url_sips)
    return 0;
  
  if (url->url_port != NULL) {
    if (!modify)
      return 1;
    url->url_port = NULL;
  }

  if (!url->url_params)
    return 0;

  for (d = p = (char *)url->url_params; *p; p += n + semi) {
    n = strcspn(p, ";");
    semi = (p[n] != '\0');

    if (modify && n == 0)
      continue;
    if (URL_PARAM_MATCH(p, "method"))
      continue;
    if (URL_PARAM_MATCH(p, "maddr"))
      continue;
    if (URL_PARAM_MATCH(p, "ttl"))
      continue;
    if (URL_PARAM_MATCH(p, "transport"))
      continue;

    if (p != d) {
      if (d != url->url_params)
	d++;
      if (p != d) {
	if (!modify)
	  return 1;
	memmove(d, p, n + 1);
      }
    }
    d += n;
  }

  if (d == p)
    return 0;
  else if (d + 1 == p)		/* empty param */
    return 0;
  else if (!modify)
    return 1;

  if (d != url->url_params)
    *d = '\0';
  else 
    url->url_params = NULL;

  return 1;
}

/** Strip transport-specific stuff. 
 *
 * The function url_strip_transport() removes transport-specific parameters
 * from a SIP or SIPS URI.  These parameters include:
 * - the port number
 * - "maddr=" parameter
 * - "transport=" parameter
 * - "ttl=" parameter
 * - "method=" parameter
 *
 * @note
 * The @a url must be a pointer to a URL structure. It is stripped in-place.
 *
 * @note
 * If the parameter string contains empty parameters, they are stripped, too.
 *
 * @return 
 * The function url_strip_transport() returns @e true, if the URL was
 * modified, @e false otherwise.
 */
int url_strip_transport(url_t *url)
{
  return url_strip_transport2(url, 1);
}

/** Check for transport-specific stuff. 
 *
 * The function url_have_transport() tests if there are transport-specific
 * parameters in a SIP or SIPS URI. These parameters include:
 * - the port number
 * - "maddr=" parameters
 * - "transport=" parameters
 * 
 * @note
 * The @a url must be a pointer to a URL structure.
 *
 * @return The function url_have_transport() returns @e true, if the URL
 * contains transport parameters, @e false otherwise.
 */
int url_have_transport(url_t const *url)
{
  return url_strip_transport2((url_t *)url, 0);
}

/**Lazily compare two URLs.
 *
 * Compare essential parts of URLs: schema, host, port, and username.
 *
 * any_url compares 0 with any other URL.
 *
 * pres: and im: URIs compares 0 with SIP URIs.
 *
 * @note
 * The @a a and @a b must be pointers to URL structures.
 *
 * @note Currently, the url parameters are not compared. This is because the
 * url_cmp() is used to sort URLs: taking parameters into account makes that
 * impossible. 
 */
int url_cmp(url_t const *a, url_t const *b)
{
  int rv;
  int url_type;

  if ((a && a->url_type == url_any) || (b && b->url_type == url_any))
    return 0;

  if (!a || !b)
    return (a != NULL) - (b != NULL);

  if ((rv = a->url_type - b->url_type)) {
#if 0
    /* presence and instant messaging URLs match magically with SIP */
    enum url_type_e a_type = a->url_type;
    enum url_type_e b_type = b->url_type;
    
    if (a_type == url_im || a_type == url_pres)
      a_type = url_sip;

    if (b_type == url_im || b_type == url_pres)
      b_type = url_sip;

    if (a_type != b_type)
#endif
      return rv;
  }

  url_type = a->url_type;	/* Or b->url_type, they are equal! */

  if (url_type <= url_unknown && 
      ((rv = !a->url_scheme - !b->url_scheme) ||
       (a->url_scheme && b->url_scheme &&
	(rv = strcasecmp(a->url_scheme, b->url_scheme)))))
    return rv;

  if ((rv = host_cmp(a->url_host, b->url_host)))
    return rv;

  if (a->url_port != b->url_port) {
    char const *a_port;
    char const *b_port;

    if (url_type != url_sip && url_type != url_sips)
      a_port = b_port = url_port_default(url_type);
    else if (host_is_ip_address(a->url_host))
      a_port = b_port = url_port_default(url_type);
    else
      a_port = b_port = "";
    
    if (a->url_port) a_port = a->url_port;
    if (b->url_port) b_port = b->url_port;

    if ((rv = strcmp(a_port, b_port)))
      return rv;
  }

  if (a->url_user != b->url_user) {
    if (a->url_user == NULL) return -1;
    if (b->url_user == NULL) return +1;
    switch (url_type) {
    case url_tel: case url_modem: case url_fax:
      rv = url_tel_cmp_numbers(a->url_user, b->url_user);