utils.c

	 * reallocate the buffer and return a message telling to retry.
	 */
	if (need > (*buf)->len && (max_len == 0 || (*buf)->len < max_len) ) {
		if (max_len && max_len < need)	/* truncate as needed */
			need = max_len;

		/* We can only realloc malloc'ed space. */
		if ((*buf)->type != DS_MALLOC)
			return AST_DYNSTR_BUILD_FAILED;
		*buf = ast_realloc(*buf, need + sizeof(struct ast_dynamic_str));
		if (*buf == NULL) /* XXX watch out, we leak memory here */
			return AST_DYNSTR_BUILD_FAILED;
		(*buf)->len = need;

		(*buf)->str[offset] = '\0';	/* Truncate the partial write. */

		if (ts)
			pthread_setspecific(ts->key, *buf);

		/* va_end() and va_start() must be done before calling
		 * vsnprintf() again. */
		return AST_DYNSTR_BUILD_RETRY;
	}
	/* update space used, keep in mind the truncation */
	(*buf)->used = (res + offset > (*buf)->len) ? (*buf)->len : res + offset;

	return res;
}

void ast_enable_packet_fragmentation(int sock)
{
#if defined(HAVE_IP_MTU_DISCOVER)
	int val = IP_PMTUDISC_DONT;
	
	if (setsockopt(sock, IPPROTO_IP, IP_MTU_DISCOVER, &val, sizeof(val)))
		ast_log(LOG_WARNING, "Unable to disable PMTU discovery. Large UDP packets may fail to be delivered when sent from this socket.\n");
#endif /* HAVE_IP_MTU_DISCOVER */
}