Uri-Path-Abbrev: Initial IETF Draft support

README.md

@@ -65,6 +65,10 @@ The following RFCs are supported
 
 * [RFC9177: Constrained Application Protocol (CoAP) Block-Wise Transfer Options Supporting Robust Transmission](https://rfc-editor.org/rfc/rfc9177)
 
+The following Internet Draft is supported
+
+* [I-D URI-Path abbreviation in CoAP](https://datatracker.ietf.org/doc/html/draft-ietf-core-uri-path-abbrev-02)
+
 There is (D)TLS support for the following libraries
 
 * [OpenSSL](https://www.openssl.org) (Minimum version 1.1.0) [PKI, PSK and PKCS11]

configure.ac

@@ -243,7 +243,7 @@ WARNING_CFLAGS="\
 # check whether or not the compiler supports -Wlogical-op (clang does not...)
 AX_CHECK_COMPILE_FLAG([-Wlogical-op], [WARNING_CFLAGS="$WARNING_CFLAGS -Wlogical-op"],,[-Werror])
 AX_CHECK_COMPILE_FLAG([-fdiagnostics-color], [CFLAGS="$CFLAGS -fdiagnostics-color"],,[-Werror])
-AX_CHECK_COMPILE_FLAG([-Wunused-result], [WARNING_CFLAGS="$WARNING_CFLAGS -Wunused-result"])
+AX_CHECK_COMPILE_FLAG([-Wunused-result], [WARNING_CFLAGS="$WARNING_CFLAGS -Wunused-result"],,[-Werror])
 
 # clang 14+ generates dwarf-5, which is not currently supported by valgrind
 if test "x$CC" = "xclang"; then
@@ -1409,7 +1409,8 @@ libcoap Configuration Summary:
       libcoap ABI version            : "$LIBCOAP_ABI_VERSION"
       libcoap libtool SO version     : "$LIBCOAP_SO_VERSION"
       libcoap DTLS lib extn          : "$LIBCOAP_DTLS_LIB_EXTENSION_NAME"
-      host system                    : "$host"]);
+      host system                    : "$host"
+      compiler                       : "$CC"]);
 if test "x$enable_server_mode" = "xyes"; then
     AC_MSG_RESULT([      build with server support      : "yes"])
 else

doc/main.md

@@ -48,6 +48,10 @@ The following RFCs are supported
 
 * [RFC9177: Constrained Application Protocol (CoAP) Block-Wise Transfer Options Supporting Robust Transmission](https://rfc-editor.org/rfc/rfc9177)
 
+The following Internet Draft is supported
+
+* [I-D URI-Path abbreviation in CoAP](https://datatracker.ietf.org/doc/html/draft-ietf-core-uri-path-abbrev-02)
+
 There is (D)TLS support for the following libraries
 
 * [OpenSSL](https://www.openssl.org) (Minimum version 1.1.0) [PKI, PSK and PKCS11]

examples/coap-client.c

@@ -59,6 +59,11 @@ int flags = 0;
 static coap_session_t *global_session;
 static unsigned char _token_data[24]; /* With support for RFC8974 */
 static coap_binary_t the_token = { 0, _token_data };
+static coap_upa_abbrev_t abbrev_mappings[] = {
+  { 0, ".well-known/core" },
+  { 1, ".well-known/rd" }
+};
+
 
 typedef struct {
   coap_binary_t *token;
@@ -587,7 +592,7 @@ usage(const char *program, const char *version) {
           coap_string_tls_version(buffer, sizeof(buffer)));
   fprintf(stderr, "%s\n", coap_string_tls_support(buffer, sizeof(buffer)));
   fprintf(stderr, "\n"
-          "Usage: %s [-a addr] [-b [num,]size] [-e text] [-f file] [-g file]\n"
+          "Usage: %s [-a addr] [-b [num,]size] [-e text] [-f file] [-g file] [-i]\n"
           "\t\t[-l loss] [-m method] [-o file] [-p port] [-q tls_engine_conf_file]\n"
           "\t\t[-r] [-s duration] [-t type] [-v num] [-w] [-x] [-y rec_secs]\n"
           "\t\t[-z] [-A type] [-B seconds]\n"
@@ -610,6 +615,7 @@ usage(const char *program, const char *version) {
           "\t-f file\t\tFile to send with PUT/POST (use '-' for STDIN)\n"
           "\t-g file\t\tFile to send with PUT/POST using individual block\n"
           "\t       \t\trequest call-back\n"
+          "\t-i     \t\tTest using Uri-Path-Abbrev path mapping\n"
           "\t-l list\t\tFail to send some datagrams specified by a comma\n"
           "\t       \t\tseparated list of numbers or number ranges\n"
           "\t       \t\t(for debugging only)\n"
@@ -665,9 +671,9 @@ usage(const char *program, const char *version) {
           "\t       \t\tcoap+ws, and coaps+ws\n"
           "\t-S     \t\tUse Proxy-Scheme instead of Proxy-Uri option if -P\n"
           "\t       \t\toption used\n"
-          "\t-T token\tDefine the initial starting token (up to 24 characters)\n"
           ,program, wait_seconds);
   fprintf(stderr,
+          "\t-T token\tDefine the initial starting token (up to 24 characters)\n"
           "\t-U     \t\tNever include Uri-Host or Uri-Port options\n"
           "\t-V num \t\tVerbosity level (default 3, maximum is 7) for (D)TLS\n"
           "\t       \t\tlibrary logging\n"
@@ -1935,6 +1941,7 @@ main(int argc, char **argv) {
   uint8_t cid_every = 0;
   int report_ind_blocks = 0;
   coap_pdu_t *resp_pdu;
+  int use_abbrev = 0;
 #ifndef _WIN32
   struct sigaction sa;
 #endif
@@ -1950,7 +1957,7 @@ main(int argc, char **argv) {
   coap_startup();
 
   while ((opt = getopt(argc, argv,
-                       "a:b:c:d:e:f:g:h:j:k:l:m:no:p:q:rs:t:u:v:wxy:zA:B:C:E:G:H:J:K:L:M:NO:P:R:ST:UV:X:Y23")) != -1) {
+                       "a:b:c:d:e:f:g:h:ij:k:l:m:no:p:q:rs:t:u:v:wxy:zA:B:C:E:G:H:J:K:L:M:NO:P:R:ST:UV:X:Y23")) != -1) {
     switch (opt) {
     case 'a':
       strncpy(node_str, optarg, NI_MAXHOST - 1);
@@ -1991,6 +1998,9 @@ main(int argc, char **argv) {
       if (!cmdline_input_from_file_f(optarg))
         payload.length = 0;
       break;
+    case 'i' :
+      use_abbrev = 1;
+      break;
     case 'j' :
       key_file = optarg;
       break;
@@ -2259,12 +2269,22 @@ main(int argc, char **argv) {
   coap_session_init_token(session, the_token.length, the_token.s);
 
   /* Convert provided uri into CoAP options */
-  if (!coap_uri_into_optlist((proxy.host.length && !use_proxy_scheme) ?
-                             &proxy : &uri, !uri_host_option ?
-                             &dst : NULL,
-                             &optlist, create_uri_opts)) {
-    coap_log_err("Failed to create options for URI\n");
-    goto failed;
+  if (use_abbrev) {
+    if (!coap_uri_into_optlist_abbrev((proxy.host.length && !use_proxy_scheme) ?
+                                      &proxy : &uri, !uri_host_option ?
+                                      &dst : NULL,
+                                      &optlist, create_uri_opts, abbrev_mappings, sizeof(abbrev_mappings)/sizeof(abbrev_mappings[0]))) {
+      coap_log_err("Failed to create options for URI\n");
+      goto failed;
+    }
+  } else {
+    if (!coap_uri_into_optlist((proxy.host.length && !use_proxy_scheme) ?
+                               &proxy : &uri, !uri_host_option ?
+                               &dst : NULL,
+                               &optlist, create_uri_opts)) {
+      coap_log_err("Failed to create options for URI\n");
+      goto failed;
+    }
   }
 
   /* set block option if requested at commandline */

examples/coap-server.c

@@ -147,6 +147,12 @@ static int call_home = 0;
 static const char *proxy_add_resource = NULL;
 static const char *proxy_add_check = NULL;
 
+static coap_upa_abbrev_t abbrev_mappings[] = {
+  { 0, ".well-known/core" },
+  { 1000, "example_data" },
+  { 1001, "time" }
+};
+
 static coap_dtls_pki_t *setup_pki(coap_context_t *ctx, coap_dtls_role_t role, char *sni);
 
 typedef struct psk_sni_def_t {
@@ -2883,6 +2889,8 @@ main(int argc, char **argv) {
   coap_context_set_max_block_size(ctx, max_block_size);
   coap_context_set_session_reconnect_time2(ctx, reconnect_secs, 10);
   coap_context_set_keepalive(ctx, reconnect_secs ? reconnect_secs : 30);
+  coap_upa_server_mapping(abbrev_mappings, sizeof(abbrev_mappings)/sizeof(abbrev_mappings[0]));
+
   if (report_each_block)
     coap_register_block_data_handler(ctx, individual_blocks);
   if (csm_max_message_size)

include/coap3/coap_net_internal.h

@@ -224,8 +224,8 @@ struct coap_context_t {
 #endif /* COAP_CLIENT_SUPPORT */
   uint32_t block_mode;             /**< Zero or more COAP_BLOCK_ or'd options */
   coap_resource_dynamic_create_t dyn_create_handler; /**< Dynamc resource create handler */
-  uint32_t dynamic_cur;            /* Current number of dynamic resources */
-  uint32_t dynamic_max;            /* Max number of dynamic resources or 0 is unlimited */
+  uint32_t dynamic_cur;            /**< Current number of dynamic resources */
+  uint32_t dynamic_max;            /**< Max number of dynamic resources or 0 is unlimited */
 };
 
 /**

include/coap3/coap_pdu.h

@@ -130,6 +130,7 @@ typedef enum coap_request_t {
 #define COAP_OPTION_OSCORE          9 /* C_____U, *,       0-255 B, RFC8613 */
 #define COAP_OPTION_URI_PATH       11 /* CU-RE__, String,  0-255 B, RFC7252 */
 #define COAP_OPTION_CONTENT_FORMAT 12 /* ____E__, uint,      0-2 B, RFC7252 */
+#define COAP_OPTION_URI_PATH_ABB   13 /* C___E__, uint,      0-4 B, RFC TBD */
 #define COAP_OPTION_CONTENT_TYPE COAP_OPTION_CONTENT_FORMAT
 /* COAP_OPTION_MAXAGE default 60 seconds if not set */
 #define COAP_OPTION_MAXAGE         14 /* _U-_E_U, uint,      0-4 B, RFC7252 */
@@ -375,6 +376,11 @@ typedef enum coap_pdu_code_t {
   COAP_SIGNALING_CODE_ABORT                     = COAP_SIGNALING_ABORT
 } coap_pdu_code_t;
 
+typedef enum {
+  COAP_BOOL_FALSE,
+  COAP_BOOL_TRUE
+} coap_bool_t;
+
 /**
  * Creates a new CoAP PDU with at least enough storage space for the given
  * @p size maximum message size. The function returns a pointer to the

include/coap3/coap_pdu_internal.h

@@ -440,14 +440,16 @@ coap_pdu_release_lkd(coap_pdu_t *pdu) {
  * @param token        The token to use in this duplicated PDU.
  * @param drop_options A list of options not to copy into the duplicated PDU.
  *                     If @c NULL, then all options are copied across.
+ * @param expand_opt_abb If COAP_BOOL_TRUE, try to expand out Uri-Path-Abbrev.
  *
  * @return The duplicated PDU or @c NULL if failure.
  */
 coap_pdu_t *coap_pdu_duplicate_lkd(const coap_pdu_t *old_pdu,
                                    coap_session_t *session,
                                    size_t token_length,
                                    const uint8_t *token,
-                                   coap_opt_filter_t *drop_options);
+                                   coap_opt_filter_t *drop_options,
+                                   coap_bool_t expand_opt_abb);
 
 /**
  * Increment reference counter on a pdu to stop it prematurely getting freed off

include/coap3/coap_proxy_internal.h

@@ -270,6 +270,16 @@ void coap_proxy_del_req(coap_proxy_entry_t *proxy_entry,  coap_proxy_req_t *prox
 void coap_delete_proxy_subscriber(coap_session_t *session, coap_bin_const_t *token,
                                   coap_mid_t mid, coap_proxy_subs_delete_t type);
 
+/**
+ * coap_proxy_log_entry() is used to log a proxy status
+ *
+ * @param incoming The incoming proxy session.
+ * @param pdu The request PDU.
+ * @param upstream_token The token used for the ongoing session.
+ * @param type The change update type.
+ */
+void coap_proxy_log_entry(coap_session_t *incoming, const coap_pdu_t *pdu,
+                          coap_bin_const_t *upstream_token, const char *type);
 /** @} */
 
 #define PROXY_CACHE_ADD(e, obj) \

include/coap3/coap_session_internal.h

@@ -227,6 +227,7 @@ struct coap_session_t {
   coap_tick_t doing_first_timeout; /**< If doing_first, when to timeout */
   coap_pdu_t *doing_first_pdu;    /**< If doing fist, PDU to retry sending */
 #endif /* COAP_CLIENT_SUPPORT */
+  uint8_t no_path_abbrev;         /**< Set is remote does not support Uri-Path-Abbrev */
   coap_mid_t remote_test_mid;     /**< mid used for checking remote
                                        support */
   uint32_t max_token_size;        /**< Largest token size supported RFC8974 */

include/coap3/coap_uri.h

@@ -84,6 +84,12 @@ typedef struct {
   enum coap_uri_scheme_t scheme;
 } coap_uri_t;
 
+typedef struct {
+  uint32_t upa_value;     /**< The Uri-Path-Abbrev option value */
+  const char *upa_path;   /**< The Uri-Path-Abbrev option path representation
+                               (withouot the leading '/') */
+} coap_upa_abbrev_t;
+
 static inline int
 coap_uri_scheme_is_secure(const coap_uri_t *uri) {
   return uri && ((uri->scheme & COAP_URI_SCHEME_SECURE_MASK) != 0);
@@ -222,6 +228,32 @@ int coap_uri_into_options(const coap_uri_t *uri, const coap_address_t *dst,
 int coap_uri_into_optlist(const coap_uri_t *uri, const coap_address_t *dst,
                           coap_optlist_t **optlist_chain,
                           int create_port_host_opt);
+/**
+ * Takes a coap_uri_t and then adds CoAP options into the @p optlist_chain.
+ * If the port is not the default port and create_port_host_opt is not 0, then
+ * the Uri-Port option is added to the @p optlist_chain.
+ * If the dst defines an address that does not match the host in uri->host and
+ * is not 0, then the Uri-Host option is added to the @p optlist_chain.
+ * Any path or query are broken down into the individual segment Uri-Path
+ * or Uri-Path-Abbrev (if mapping match) or Uri-Query options and added to
+ * the @p optlist_chain.
+ *
+ * @param uri     The coap_uri_t object.
+ * @param dst     The destination, or NULL if URI_HOST not to be added.
+ * @param optlist_chain Where to store the chain of options.
+ * @param create_port_host_opt @c 1 if port/host option to be added
+ *                             (if non-default) else @c 0.
+ * @param mapping A path mapping to value for Uri-Path-Abbrev table or NULL.
+ *                (path does not have the leading '/').
+ * @param count   Number of Uri-Path-Abbrev table entries.
+ *
+ * @return        @c 1 on success, @c 0 if error.
+ *
+ */
+int coap_uri_into_optlist_abbrev(const coap_uri_t *uri, const coap_address_t *dst,
+                                 coap_optlist_t **optlist_chain,
+                                 int create_port_host_opt,
+                                 coap_upa_abbrev_t *mapping, uint32_t count);
 
 /**
  * Splits the given URI path into segments. Each segment is preceded
@@ -261,6 +293,28 @@ int coap_split_path(const uint8_t *path,
 int coap_path_into_optlist(const uint8_t *path, size_t length,
                            coap_option_num_t optnum,
                            coap_optlist_t **optlist_chain);
+/**
+ * Splits the given URI path into '/' separate segments, and then adds
+ * the Uri-Path / Location-Path option for each segment to the @p optlist_chain.
+ *
+ * Note: any segments that are just '.' or '..' are stripped out.
+ *
+ * @param path   The path string to split.
+ * @param length The actual length of @p path.
+ * @param optnum The CoAP option (COAP_OPTION_URI_PATH or
+ *               COAP_OPTION_LOCATION_PATH)
+ * @param optlist_chain The chain of optlists to add to. optlist_chain
+ *                      parent is to be NULL or a previous set of optlists.
+ * @param mapping A path mapping to value for Uri-Path-Abbrev table or NULL.
+ *                (path does not have the leading '/').
+ * @param count   Number of Uri-Path-Abbrev table entries.
+ *
+ * @return       @c 1 on success else @c 0 if error.
+ */
+int coap_path_into_optlist_abbrev(const uint8_t *path, size_t length,
+                                  coap_option_num_t optnum,
+                                  coap_optlist_t **optlist_chain,
+                                  coap_upa_abbrev_t *mapping, uint32_t count);
 
 /**
  * Splits the given URI query into segments. Each segment is preceded
@@ -319,6 +373,27 @@ coap_string_t *coap_get_query(const coap_pdu_t *request);
  */
 coap_string_t *coap_get_uri_path(const coap_pdu_t *request);
 
+/**
+ * Define a Path to use if an Uri-Path-Abbrev option fails and the client
+ * is to retry the request using Uri-Path instread of Uri-Path-Abbrev.
+ *
+ * @param mapping A path mapping to value for Uri-Path-Abbrev table or NULL
+                  if the previous mapping is to be cleared.
+ *                (path does not have the leading '/').
+ * @param count   Number of Uri-Path-Abbrev table entries.
+ */
+void coap_upa_client_fallback(coap_upa_abbrev_t *mapping, uint32_t count);
+
+/**
+ * Define a Path to use on receipt of an Uri-Path-Abbrev option value.
+ *
+ * @param mapping A path mapping to value for Uri-Path-Abbrev table or NULL
+                  if the previous mapping is to be cleared.
+ *                (path does not have the leading '/').
+ * @param count   Number of Uri-Path-Abbrev table entries.
+ */
+void coap_upa_server_mapping(coap_upa_abbrev_t *mapping, uint32_t count);
+
 /** @} */
 
 #ifdef __cplusplus

include/coap3/coap_uri_internal.h

@@ -37,7 +37,16 @@ typedef struct {
   coap_uri_scheme_t scheme; /**< scheme */
 } coap_uri_info_t;
 
+typedef struct coap_upa_chain_t {
+  struct coap_upa_chain_t *next; /**< Next entry in the chain */
+  uint32_t upa_value;            /**< The Uri-Path-Abbrev option value */
+  char *upa_path;                /**< The Uri-Path-Abbrev option path representation
+                                     (withouot the leading '/') */
+} coap_upa_chain_t;
+
 extern coap_uri_info_t coap_uri_scheme[COAP_URI_SCHEME_LAST];
+extern coap_upa_chain_t *coap_upa_client_fallback_chain;
+extern coap_upa_chain_t *coap_upa_server_mapping_chain;
 
 /**
  * replace any % hex definitions with the actual character.
@@ -47,6 +56,21 @@ extern coap_uri_info_t coap_uri_scheme[COAP_URI_SCHEME_LAST];
  */
 void coap_replace_percents(coap_optlist_t *optlist);
 
+/**
+ * Determine the expanded Uri-Path-Abbrev option value.
+ *
+ * @param chain Chain holding the information.
+ * @param value The Uri-Path-Abbrev numeric value
+ *
+ * @return The expanded textual path or @c NULL if not found.
+ */
+const char *coap_map_abbrev_uri_path(coap_upa_chain_t *chain, u_int value);
+
+int coap_map_uri_path_abbrev(coap_upa_chain_t *chain, const char *path, size_t length,
+                             u_int *value);
+
+void coap_delete_upa_chain(coap_upa_chain_t *chain);
+
 /** @} */
 
 #ifdef __cplusplus

libcoap-3.map

@@ -206,6 +206,7 @@ global:
   coap_package_name;
   coap_package_version;
   coap_path_into_optlist;
+  coap_path_into_optlist_abbrev;
   coap_pdu_duplicate;
   coap_pdu_get_code;
   coap_pdu_get_mid;
@@ -348,8 +349,11 @@ global:
   coap_tls_engine_configure;
   coap_tls_engine_remove;
   coap_tls_is_supported;
+  coap_upa_client_fallback;
+  coap_upa_server_mapping;
   coap_uri_into_options;
   coap_uri_into_optlist;
+  coap_uri_into_optlist_abbrev;
   coap_verify_proxy_scheme_supported;
   coap_write_block_b_opt;
   coap_write_block_opt;