From d916b33bc6f5bd07b85cd588f50f367321de7d6e Mon Sep 17 00:00:00 2001
From: Jan Romann <jan.romann@uni-bremen.de>
Date: Wed, 19 Oct 2022 15:04:46 +0200
Subject: [PATCH] sys/net/nanocoap: introduce Accept option helper

---
 sys/include/net/nanocoap.h                    | 10 ++++++++++
 sys/net/application_layer/nanocoap/nanocoap.c | 14 ++++++++++++--
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/sys/include/net/nanocoap.h b/sys/include/net/nanocoap.h
index df5d0fec12..c782ea2345 100644
--- a/sys/include/net/nanocoap.h
+++ b/sys/include/net/nanocoap.h
@@ -628,6 +628,16 @@ uint8_t *coap_find_option(coap_pkt_t *pkt, unsigned opt_num);
  */
 unsigned coap_get_content_type(coap_pkt_t *pkt);
 
+/**
+ * @brief   Get the Accept option value from a packet if present
+ *
+ * @param[in]   pkt     packet to work on
+ *
+ * @returns     the packet's Accept option value if included,
+ *              COAP_FORMAT_NONE otherwise
+ */
+unsigned coap_get_accept(coap_pkt_t *pkt);
+
 /**
  * @brief   Get a uint32 option value
  *
diff --git a/sys/net/application_layer/nanocoap/nanocoap.c b/sys/net/application_layer/nanocoap/nanocoap.c
index 23ec4084d0..937b40568f 100644
--- a/sys/net/application_layer/nanocoap/nanocoap.c
+++ b/sys/net/application_layer/nanocoap/nanocoap.c
@@ -280,9 +280,9 @@ uint8_t *coap_iterate_option(coap_pkt_t *pkt, uint8_t **optpos,
     }
 }
 
-unsigned coap_get_content_type(coap_pkt_t *pkt)
+static unsigned _get_content_format(coap_pkt_t *pkt, unsigned int opt_num)
 {
-    uint8_t *opt_pos = coap_find_option(pkt, COAP_OPT_CONTENT_FORMAT);
+    uint8_t *opt_pos = coap_find_option(pkt, opt_num);
     unsigned content_type = COAP_FORMAT_NONE;
     if (opt_pos) {
         uint16_t delta;
@@ -302,6 +302,16 @@ unsigned coap_get_content_type(coap_pkt_t *pkt)
     return content_type;
 }
 
+unsigned coap_get_content_type(coap_pkt_t *pkt)
+{
+    return _get_content_format(pkt, COAP_OPT_CONTENT_FORMAT);
+}
+
+unsigned coap_get_accept(coap_pkt_t *pkt)
+{
+    return _get_content_format(pkt, COAP_OPT_ACCEPT);
+}
+
 ssize_t coap_opt_get_next(const coap_pkt_t *pkt, coap_optpos_t *opt,
                           uint8_t **value, bool init_opt)
 {