Add sorting of optlist

include/coap3/coap_option.h

@@ -376,6 +376,16 @@ coap_optlist_t *coap_new_optlist(uint16_t number,
  */
 int coap_add_optlist_pdu(coap_pdu_t *pdu, coap_optlist_t **optlist_chain);
 
+
+/**
+ * @brief Sorts the optlist chain
+ *
+ * @param options The optlist chain to sort
+ *
+ * @return @c 1 if sorted successfully, @c 0 otherwise.
+ */
+int coap_sort_optlist(coap_optlist_t **options);
+
 /**
  * Adds @p optlist to the given @p optlist_chain. The optlist_chain variable
  * be set to NULL before the initial call to coap_insert_optlist().

libcoap-3.map

@@ -333,6 +333,7 @@ global:
   coap_socket_get_flags;
   coap_socket_set_flags;
   coap_socket_strerror;
+  coap_sort_optlist;
   coap_split_path;
   coap_split_proxy_uri;
   coap_split_query;

libcoap-3.sym

@@ -331,6 +331,7 @@ coap_socket_get_fd
 coap_socket_get_flags
 coap_socket_set_flags
 coap_socket_strerror
+coap_sort_optlist
 coap_split_path
 coap_split_proxy_uri
 coap_split_query

man/Makefile.am

@@ -192,6 +192,7 @@ install-man: install-man3 install-man5 install-man7
 	@echo ".so man3/coap_pdu_access.3" > coap_get_uri_path.3
 	@echo ".so man3/coap_pdu_setup.3" > coap_insert_optlist.3
 	@echo ".so man3/coap_pdu_setup.3" > coap_delete_optlist.3
+	@echo ".so man3/coap_pdu_setup.3" > coap_sort_optlist.3
 	@echo ".so man3/coap_pdu_setup.3" > coap_encode_var_safe.3
 	@echo ".so man3/coap_pdu_setup.3" > coap_encode_var_safe8.3
 	@echo ".so man3/coap_pdu_setup.3" > coap_add_optlist_pdu.3

man/coap_pdu_setup.txt.in

@@ -20,6 +20,7 @@ coap_add_token,
 coap_new_optlist,
 coap_insert_optlist,
 coap_delete_optlist,
+coap_sort_optlist,
 coap_encode_var_safe,
 coap_encode_var_safe8,
 coap_add_optlist_pdu,
@@ -64,6 +65,8 @@ coap_optlist_t *_optlist_);*
 
 *void coap_delete_optlist(coap_optlist_t *_optlist_chain_);*
 
+*int coap_sort_optlist(coap_optlist_t **_options_);*
+
 *unsigned int coap_encode_var_safe(uint8_t *_buffer_, size_t _size_,
 unsigned int _value_);*
 
@@ -383,6 +386,17 @@ off all the _optlist_chain_ entries.
 The *coap_delete_optlist*() function deletes and frees off all the optlist
 entries in the _optlist_chain_.
 
+*Function: coap_sort_optlist()*
+
+The *coap_sort_optlist*() function sorts the optlist chain pointed to by
+_options_ into ascending option number order (RFC 7252 ordering for delta
+encoding).  The chain is reordered in place.  Use this when the list was
+built with *coap_insert_optlist*() and you need it ordered before use (for
+example, before adding options to a PDU manually or for inspection).
+*coap_add_optlist_pdu*() sorts internally, so calling *coap_sort_optlist*()
+is not required when using that function.  Returns 1 if sorted successfully,
+0 if _options_ is NULL or the chain is empty.
+
 *Function: coap_add_optlist_pdu()*
 
 The *coap_add_optlist_pdu*() function sorts all of the entries in
@@ -570,8 +584,8 @@ _PDU_ or NULL if there is a malloc or parameter failure.
 *coap_new_optlist*() returns a newly created _optlist_ or NULL
 if there is a malloc failure.
 
-*coap_add_token*(), *coap_insert_optlist*(), *coap_add_optlist_pdu*()
-and *coap_add_data*() return 0 on failure, 1 on success.
+*coap_add_token*(), *coap_insert_optlist*(), *coap_sort_optlist*(),
+*coap_add_optlist_pdu*() and *coap_add_data*() return 0 on failure, 1 on success.
 
 *coap_encode_var_safe*() returns either the length of bytes
 encoded (which can be 0 when encoding 0) or 0 on failure.

src/coap_option.c

@@ -567,6 +567,16 @@ coap_add_optlist_pdu(coap_pdu_t *pdu, coap_optlist_t **options) {
   return 1;
 }
 
+int
+coap_sort_optlist(coap_optlist_t **options) {
+  if (options && *options) {
+    /* sort options for delta encoding */
+    LL_SORT((*options), order_opts);
+    return 1;
+  }
+  return 0;
+}
+
 int
 coap_insert_optlist(coap_optlist_t **head, coap_optlist_t *node) {
   if (!node) {