net/nanocoap: Options sort module

makefiles/pseudomodules.inc.mk

@@ -50,7 +50,9 @@ PSEUDOMODULES += lwip_tcp
 PSEUDOMODULES += lwip_udp
 PSEUDOMODULES += lwip_udplite
 PSEUDOMODULES += mpu_stack_guard
-PSEUDOMODULES += nanocoap_%
+PSEUDOMODULES += nanocoap_sock
+PSEUDOMODULES += nanocoap_opt2
+PSEUDOMODULES += nanocoap_opt2_sort
 PSEUDOMODULES += netdev_default
 PSEUDOMODULES += netif
 PSEUDOMODULES += netstats

sys/include/net/nanocoap.h

@@ -1,16 +1,59 @@
 /*
  * Copyright (C) 2016-17 Kaspar Schleiser <kaspar@schleiser.de>
+ * Copyright (C) 2018 Ken Bannister <kb2ma@runbox.com>
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level
  * directory for more details.
  */
 
 /**
- * @defgroup    net_nanocoap nanocoap small CoAP library
+ * @defgroup    net_nanocoap Nanocoap, small CoAP library
  * @ingroup     net
  * @brief       Provides CoAP functionality optimized for minimal resource usage
  *
+ * nanocoap includes both server-side response generation and client-side
+ * request generation.
+ *
+ * ## Write Options and Payload ##
+ *
+ * For both server responses and client requests, CoAP uses an Option mechanism
+ * to encode message metadata that is not required for each message. For
+ * example, the resource URI path is required only for a request, and is encoded
+ * as the Uri-Path option.
+ *
+ * nanocoap provides two APIs for writing CoAP options:
+ *
+ * A **minimal** API that requires only a reference to the buffer. However, the
+ * caller must remember and provide the last option number written, as well
+ * as the buffer position. The minimal API always is available.
+ *
+ * A convenient **struct-based** API that uses a coap_pkt_t struct to track each
+ * option as it is written. Activate this API by use of the `nanocoap_opt2`
+ * submodule.
+ *
+ * For either API, by default the caller *must* write options in order by option
+ * number (see "CoAP option numbers", below). However, the struct-based API
+ * supports use of the `nanocoap_opt2_sort` module. This module allows the user
+ * to enter options in any order, and then sorts them in coap_opt_finish().
+ *
+ * ### Higher-level, struct-based API ###
+ *
+ * Before starting, ensure the buffer and CoAP header have been initialized.
+ * For a request, use `coap_build_hdr()`. For a response, update the header
+ * attributes from the request buffer as needed.
+ *
+ * Use `coap_pkt_init()` to initialize the coap_pkt_t struct, including the
+ * array of options.
+ *
+ * Next, use the `coap_opt_add_xxx()` functions to write each option, like
+ * `coap_opt_add_uint()`. When all options have been added, use
+ * `coap_opt_finish()`.
+ *
+ * Finally, write any message payload at the coap_pkt_t payload pointer
+ * attribute. The `payload_len` attribute provides the available length in the
+ * buffer.
+ *
  * @{
  *
  * @file
@@ -403,6 +446,7 @@ ssize_t coap_handle_req(coap_pkt_t *pkt, uint8_t *resp_buf, unsigned resp_buf_le
 ssize_t coap_build_hdr(coap_hdr_t *hdr, unsigned type, uint8_t *token,
                        size_t token_len, unsigned code, uint16_t id);
 
+#ifdef MODULE_NANOCOAP_OPT2
 /**
  * @brief   Initialize a packet struct, to build a message buffer
  *
@@ -418,6 +462,7 @@ ssize_t coap_build_hdr(coap_hdr_t *hdr, unsigned type, uint8_t *token,
  * @param[in]    header_len length of header in buf, including token
  */
 void coap_pkt_init(coap_pkt_t *pkt, uint8_t *buf, size_t len, size_t header_len);
+#endif
 
 /**
  * @brief   Insert a CoAP option into buffer
@@ -528,6 +573,7 @@ size_t coap_put_option_block1(uint8_t *buf, uint16_t lastonum, unsigned blknum,
  */
 size_t coap_put_block1_ok(uint8_t *pkt_pos, coap_block1_t *block1, uint16_t lastonum);
 
+#ifdef MODULE_NANOCOAP_OPT2
 /**
  * @brief   Encode the given string as option(s) into pkt
  *
@@ -573,6 +619,7 @@ ssize_t coap_opt_add_uint(coap_pkt_t *pkt, uint16_t optnum, uint32_t value);
  * @return        total number of bytes written to buffer
  */
 ssize_t coap_opt_finish(coap_pkt_t *pkt, uint16_t flags);
+#endif   /* MODULE_NANOCOAP_OPT2 */
 
 /**
  * @brief   Get content type from packet

sys/net/application_layer/nanocoap/Makefile

@@ -1,3 +1,11 @@
 SRC := nanocoap.c
-SUBMODULES := 1
+
+ifneq (,$(filter nanocoap_sock,$(USEMODULE)))
+  SRC += sock.c
+endif
+
+ifneq (,$(filter nanocoap_opt2,$(USEMODULE)))
+  SRC += opt2_add.c
+endif
+
 include $(RIOTBASE)/Makefile.base

sys/net/application_layer/nanocoap/nanocoap.c

@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2016-18 Kaspar Schleiser <kaspar@schleiser.de>
+ * Copyright (C) 2018 Ken Bannister <kb2ma@runbox.com>
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level
@@ -14,6 +15,7 @@
  * @brief       Nanocoap implementation
  *
  * @author      Kaspar Schleiser <kaspar@schleiser.de>
+ * @author      Ken Bannister <kb2ma@runbox.com>
  *
  * @}
  */
@@ -31,7 +33,11 @@
 static int _decode_value(unsigned val, uint8_t **pkt_pos_ptr, uint8_t *pkt_end);
 int coap_get_option_uint(coap_pkt_t *pkt, unsigned opt_num, uint32_t *target);
 static uint32_t _decode_uint(uint8_t *pkt_pos, unsigned nbytes);
-static size_t _encode_uint(uint32_t *val);
+size_t _encode_uint(uint32_t *val);
+
+#ifdef MODULE_NANOCOAP_OPT2_SORT
+extern ssize_t _sort_opts(coap_pkt_t *pkt);
+#endif
 
 /* http://tools.ietf.org/html/rfc7252#section-3
  *  0                   1                   2                   3
@@ -147,7 +153,7 @@ uint8_t *coap_find_option(coap_pkt_t *pkt, unsigned opt_num)
     return NULL;
 }
 
-static uint8_t *_parse_option(coap_pkt_t *pkt, uint8_t *pkt_pos, uint16_t *delta, int *opt_len)
+uint8_t *_parse_option(coap_pkt_t *pkt, uint8_t *pkt_pos, uint16_t *delta, int *opt_len)
 {
     uint8_t *hdr_end = pkt->payload;
 
@@ -383,15 +389,6 @@ ssize_t coap_build_hdr(coap_hdr_t *hdr, unsigned type, uint8_t *token, size_t to
     return sizeof(coap_hdr_t) + token_len;
 }
 
-void coap_pkt_init(coap_pkt_t *pkt, uint8_t *buf, size_t len, size_t header_len)
-{
-    memset(pkt, 0, sizeof(coap_pkt_t));
-    pkt->hdr = (coap_hdr_t *)buf;
-    pkt->token = buf + sizeof(coap_hdr_t);
-    pkt->payload = buf + header_len;
-    pkt->payload_len = len - header_len;
-}
-
 static int _decode_value(unsigned val, uint8_t **pkt_pos_ptr, uint8_t *pkt_end)
 {
     uint8_t *pkt_pos = *pkt_pos_ptr;
@@ -450,7 +447,7 @@ static uint32_t _decode_uint(uint8_t *pkt_pos, unsigned nbytes)
     return ntohl(res);
 }
 
-static size_t _encode_uint(uint32_t *val)
+size_t _encode_uint(uint32_t *val)
 {
     uint8_t *tgt = (uint8_t *)val;
     size_t size = 0;
@@ -497,9 +494,12 @@ static unsigned _put_delta_optlen(uint8_t *buf, unsigned offset, unsigned shift,
 
 size_t coap_put_option(uint8_t *buf, uint16_t lastonum, uint16_t onum, uint8_t *odata, size_t olen)
 {
+#ifdef MODULE_NANOCOAP_OPT2_SORT
+    unsigned delta = (lastonum <= onum) ? (onum - lastonum) : 0;
+#else
     assert(lastonum <= onum);
-
     unsigned delta = (onum - lastonum);
+#endif
     *buf = 0;
 
     /* write delta value to option header: 4 upper bits of header (shift 4) +
@@ -604,85 +604,6 @@ size_t coap_put_option_uri(uint8_t *buf, uint16_t lastonum, const char *uri, uin
     return bufpos - buf;
 }
 
-/* Common functionality for addition of an option */
-static ssize_t _add_opt_pkt(coap_pkt_t *pkt, uint16_t optnum, uint8_t *val,
-                            size_t val_len)
-{
-    assert(pkt->options_len < NANOCOAP_NOPTS_MAX);
-
-    uint16_t lastonum = (pkt->options_len)
-            ? pkt->options[pkt->options_len - 1].opt_num : 0;
-    assert(optnum >= lastonum);
-
-    size_t optlen = coap_put_option(pkt->payload, lastonum, optnum, val, val_len);
-    assert(pkt->payload_len > optlen);
-
-    pkt->options[pkt->options_len].opt_num = optnum;
-    pkt->options[pkt->options_len].offset = pkt->payload - (uint8_t *)pkt->hdr;
-    pkt->options_len++;
-    pkt->payload += optlen;
-    pkt->payload_len -= optlen;
-
-    return optlen;
-}
-
-ssize_t coap_opt_add_string(coap_pkt_t *pkt, uint16_t optnum, const char *string,
-                           char separator)
-{
-    size_t unread_len = strlen(string);
-    if (!unread_len) {
-        return 0;
-    }
-    char *uripos = (char *)string;
-    size_t write_len = 0;
-
-    while (unread_len) {
-        size_t part_len;
-        uripos++;
-        uint8_t *part_start = (uint8_t *)uripos;
-
-        while (unread_len--) {
-            if ((*uripos == separator) || (*uripos == '\0')) {
-                break;
-            }
-            uripos++;
-        }
-
-        part_len = (uint8_t *)uripos - part_start;
-
-        if (part_len) {
-            if (pkt->options_len == NANOCOAP_NOPTS_MAX) {
-                return -ENOSPC;
-            }
-            write_len += _add_opt_pkt(pkt, optnum, part_start, part_len);
-        }
-    }
-
-    return write_len;
-}
-
-ssize_t coap_opt_add_uint(coap_pkt_t *pkt, uint16_t optnum, uint32_t value)
-{
-    uint32_t tmp = value;
-    unsigned tmp_len = _encode_uint(&tmp);
-    return _add_opt_pkt(pkt, optnum, (uint8_t *)&tmp, tmp_len);
-}
-
-ssize_t coap_opt_finish(coap_pkt_t *pkt, uint16_t flags)
-{
-    if (flags & COAP_OPT_FINISH_PAYLOAD) {
-        assert(pkt->payload_len > 1);
-
-        *pkt->payload++ = 0xFF;
-        pkt->payload_len--;
-    }
-    else {
-        pkt->payload_len = 0;
-    }
-
-    return pkt->payload - (uint8_t *)pkt->hdr;
-}
-
 ssize_t coap_well_known_core_default_handler(coap_pkt_t *pkt, uint8_t *buf, \
                                              size_t len, void *context)
 {