coap_constants.h

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// Copyright 2024-2025 The Aerospace Corporation.
// This file is a part of SatCat5, licensed under CERN-OHL-W v2 or later.
 
#pragma once
 
#include <satcat5/types.h>
 
namespace satcat5 {
    namespace coap {
        constexpr u8
            PAYLOAD_MARKER = 255,   // Payload marker
            TYPE_CON = 0x00,        // Confirmable
            TYPE_NON = 0x10,        // Non-confirmable
            TYPE_ACK = 0x20,        // Acknowledgement
            TYPE_RST = 0x30,        // Reset
            VERSION1 = (1 << 6);    // Version 1 (RFC7252)
 
        struct Code {
            u8 value;                           
 
            // Constructors.
            explicit constexpr Code(u8 val)
                : value(val) {}                 
            constexpr Code(u8 x, u8 yy)
                : value((x << 5) | yy) {}       
            constexpr Code(const Code& other)
                : value(other.value) {}         
            Code& operator=(const Code& other)
                { value = other.value; return *this; } 
 
            // Basic accessors.
            constexpr u8 category() const
                { return (value >> 5) & 0x7; }  
            constexpr u8 subtype() const
                { return (value & 0x1F); }      
 
            // Comparison operators.
            bool operator==(const Code& other) const
                { return (value == other.value); }
            bool operator!=(const Code& other) const
                { return (value != other.value); }
 
            constexpr bool is_empty() const
                { return (value == 0); }
            constexpr bool is_request() const
                { return (category() == 0); }
            constexpr bool is_success() const
                { return (category() == 2); }
            constexpr bool is_error() const
                { return (category() == 4) || (category() == 5); }
            constexpr bool is_response() const
                { return is_empty() || is_success() || is_error(); }
        };
 
        constexpr Code                  // Request codes (Section 12.1.1)
            CODE_EMPTY          (0,0),  
            CODE_GET            (0,1),  
            CODE_POST           (0,2),  
            CODE_PUT            (0,3),  
            CODE_DELETE         (0,4);  
        constexpr Code                  // Response codes (Section 12.1.2)
            CODE_CREATED        (2,1),  
            CODE_DELETED        (2,2),  
            CODE_VALID          (2,3),  
            CODE_CHANGED        (2,4),  
            CODE_CONTENT        (2,5),  
            CODE_CONTINUE       (2,31), 
            CODE_BAD_REQUEST    (4,0),  
            CODE_UNAUTHORIZED   (4,1),  
            CODE_BAD_OPTION     (4,2),  
            CODE_FORBIDDEN      (4,3),  
            CODE_NOT_FOUND      (4,4),  
            CODE_BAD_METHOD     (4,5),  
            CODE_NOT_ACCEPT     (4,6),  
            CODE_PRECND_FAIL    (4,12), 
            CODE_TOO_LARGE      (4,13), 
            CODE_BAD_FORMAT     (4,15), 
            CODE_SERVER_ERROR   (5,0),  
            CODE_NOT_IMPL       (5,1),  
            CODE_BAD_GATEWAY    (5,2),  
            CODE_UNAVAILABLE    (5,3),  
            CODE_GATE_TIMEOUT   (5,4),  
            CODE_NO_PROXY       (5,5);  
 
        // Option numbers (Section 12.2)
        constexpr u16
            OPTION_IF_MATCH     = 1,    
            OPTION_URI_HOST     = 3,    
            OPTION_ETAG         = 4,    
            OPTION_IF_NONE      = 5,    
            OPTION_URI_PORT     = 7,    
            OPTION_LOC_PATH     = 8,    
            OPTION_URI_PATH     = 11,   
            OPTION_FORMAT       = 12,   
            OPTION_MAX_AGE      = 14,   
            OPTION_URI_QUERY    = 15,   
            OPTION_ACCEPT       = 17,   
            OPTION_LOC_QUERY    = 20,   
            OPTION_BLOCK2       = 23,   
            OPTION_BLOCK1       = 27,   
            OPTION_PROXY_URI    = 35,   
            OPTION_PROXY_SCH    = 39,   
            OPTION_SIZE1        = 60;   
 
        // Content-format codes (Section 12.3)
        // (These are used with OPTION_FORMAT and OPTION_ACCEPT.)
        constexpr u16                   // Equivalent MIME specifier:
            FORMAT_TEXT         = 0,    
            FORMAT_LINK         = 40,   
            FORMAT_XML          = 41,   
            FORMAT_BYTES        = 42,   
            FORMAT_EXI          = 47,   
            FORMAT_JSON         = 50,   
            FORMAT_CBOR         = 60,   
            FORMAT_CBOR_SEQ     = 63;   
    }
}