aboutsummaryrefslogtreecommitdiffstats
path: root/host/lib/transport/chdr.cpp
blob: 5e552320e57a0ae33504793dd00f18f147b2d2ce (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
//
// Copyright 2014 Ettus Research LLC
//
// SPDX-License-Identifier: GPL-3.0
//

#include <uhd/transport/chdr.hpp>
#include <uhd/utils/byteswap.hpp>
#include <uhd/exception.hpp>

//define the endian macros to convert integers
#ifdef BOOST_BIG_ENDIAN
    #define BE_MACRO(x) (x)
    #define LE_MACRO(x) uhd::byteswap(x)
#else
    #define BE_MACRO(x) uhd::byteswap(x)
    #define LE_MACRO(x) (x)
#endif

using namespace uhd::transport::vrt;

static const uint32_t HDR_FLAG_TSF = (1 << 29);
static const uint32_t HDR_FLAG_EOB = (1 << 28);
static const uint32_t HDR_FLAG_ERROR = (1 << 28);

/***************************************************************************/
/* Packing                                                                 */
/***************************************************************************/
/*! Translate the contents of \p if_packet_info into a 32-Bit word and return it.
 */
UHD_INLINE uint32_t _hdr_pack_chdr(
        if_packet_info_t &if_packet_info
) {
    // Set fields in if_packet_info
    if_packet_info.num_header_words32 = 2 + (if_packet_info.has_tsf ? 2 : 0);
    if_packet_info.num_packet_words32 =
            if_packet_info.num_header_words32 +
            if_packet_info.num_payload_words32;

    uint16_t pkt_length =
        if_packet_info.num_payload_bytes + (4 * if_packet_info.num_header_words32);
    uint32_t chdr = 0
        // 2 Bits: Packet type
        | (if_packet_info.packet_type << 30)
        // 1 Bit: Has time
        | (if_packet_info.has_tsf ? HDR_FLAG_TSF : 0)
        // 1 Bit: EOB or Error
        | ((if_packet_info.eob or if_packet_info.error) ? HDR_FLAG_EOB : 0)
        // 12 Bits: Sequence number
        | ((if_packet_info.packet_count & 0xFFF) << 16)
        // 16 Bits: Total packet length
        | pkt_length;
    return chdr;
}

void chdr::if_hdr_pack_be(
        uint32_t *packet_buff,
        if_packet_info_t &if_packet_info
) {
    // Write header and update if_packet_info
    packet_buff[0] = BE_MACRO(_hdr_pack_chdr(if_packet_info));

    // Write SID
    packet_buff[1] = BE_MACRO(if_packet_info.sid);

    // Write time
    if (if_packet_info.has_tsf) {
        packet_buff[2] = BE_MACRO(uint32_t(if_packet_info.tsf >> 32));
        packet_buff[3] = BE_MACRO(uint32_t(if_packet_info.tsf >> 0));
    }
}

void chdr::if_hdr_pack_le(
        uint32_t *packet_buff,
        if_packet_info_t &if_packet_info
) {
    // Write header and update if_packet_info
    packet_buff[0] = LE_MACRO(_hdr_pack_chdr(if_packet_info));

    // Write SID
    packet_buff[1] = LE_MACRO(if_packet_info.sid);

    // Write time
    if (if_packet_info.has_tsf) {
        packet_buff[2] = LE_MACRO(uint32_t(if_packet_info.tsf >> 32));
        packet_buff[3] = LE_MACRO(uint32_t(if_packet_info.tsf >> 0));
    }
}


/***************************************************************************/
/* Unpacking                                                               */
/***************************************************************************/
UHD_INLINE void _hdr_unpack_chdr(
        const uint32_t chdr,
        if_packet_info_t &if_packet_info
) {
    // Set constant members
    if_packet_info.link_type = if_packet_info_t::LINK_TYPE_CHDR;
    if_packet_info.has_cid = false;
    if_packet_info.has_sid = true;
    if_packet_info.has_tsi = false;
    if_packet_info.has_tlr = false;
    if_packet_info.sob = false;

    // Set configurable members
    if_packet_info.has_tsf = (chdr & HDR_FLAG_TSF) > 0;
    if_packet_info.packet_type = if_packet_info_t::packet_type_t((chdr >> 30) & 0x3);
    if_packet_info.eob = (if_packet_info.packet_type == if_packet_info_t::PACKET_TYPE_DATA)
                         && ((chdr & HDR_FLAG_EOB) > 0);
    if_packet_info.error = (if_packet_info.packet_type == if_packet_info_t::PACKET_TYPE_RESP)
                         && ((chdr & HDR_FLAG_ERROR) > 0);
    if_packet_info.packet_count = (chdr >> 16) & 0xFFF;

    // Set packet length variables
    if (if_packet_info.has_tsf) {
        if_packet_info.num_header_words32 = 4;
    } else {
        if_packet_info.num_header_words32 = 2;
    }
    size_t pkt_size_bytes = (chdr & 0xFFFF);
    size_t pkt_size_word32 = (pkt_size_bytes / 4) + ((pkt_size_bytes % 4) ? 1 : 0);
    // Check lengths match:
    if (pkt_size_word32 < if_packet_info.num_header_words32) {
        throw uhd::value_error("Bad CHDR or invalid packet length");
    }
    if (if_packet_info.num_packet_words32 < pkt_size_word32) {
        throw uhd::value_error("Bad CHDR or packet fragment");
    }
    if_packet_info.num_payload_bytes = pkt_size_bytes - (4 * if_packet_info.num_header_words32);
    if_packet_info.num_payload_words32 = pkt_size_word32 - if_packet_info.num_header_words32;
}

void chdr::if_hdr_unpack_be(
        const uint32_t *packet_buff,
        if_packet_info_t &if_packet_info
) {
    // Read header and update if_packet_info
    uint32_t chdr = BE_MACRO(packet_buff[0]);
    _hdr_unpack_chdr(chdr, if_packet_info);

    // Read SID
    if_packet_info.sid = BE_MACRO(packet_buff[1]);

    // Read time (has_tsf was updated earlier)
    if (if_packet_info.has_tsf) {
        if_packet_info.tsf = 0
            | uint64_t(BE_MACRO(packet_buff[2])) << 32
            | BE_MACRO(packet_buff[3]);
    }
}

void chdr::if_hdr_unpack_le(
        const uint32_t *packet_buff,
        if_packet_info_t &if_packet_info
) {
    // Read header and update if_packet_info
    uint32_t chdr = LE_MACRO(packet_buff[0]);
    _hdr_unpack_chdr(chdr, if_packet_info);

    // Read SID
    if_packet_info.sid = LE_MACRO(packet_buff[1]);

    // Read time (has_tsf was updated earlier)
    if (if_packet_info.has_tsf) {
        if_packet_info.tsf = 0
            | uint64_t(LE_MACRO(packet_buff[2])) << 32
            | LE_MACRO(packet_buff[3]);
    }
}