lsquic_version.c revision be4cfad0 
1/* Copyright (c) 2017 - 2018 LiteSpeed Technologies Inc.  See LICENSE. */
2#include <string.h>
3
4#include "lsquic.h"
5#include "lsquic_int_types.h"
6#include "lsquic_version.h"
7
8
9static const unsigned char version_tags[N_LSQVER][4] =
10{
11    [LSQVER_035] = { 'Q', '0', '3', '5', },
12    [LSQVER_037] = { 'Q', '0', '3', '7', },
13    [LSQVER_038] = { 'Q', '0', '3', '8', },
14    [LSQVER_039] = { 'Q', '0', '3', '9', },
15    [LSQVER_041] = { 'Q', '0', '4', '1', },
16    [LSQVER_042] = { 'Q', '0', '4', '2', },
17};
18
19
20uint32_t
21lsquic_ver2tag (unsigned version)
22{
23    lsquic_ver_tag_t tag;
24    if (version < N_LSQVER)
25    {
26        memcpy(&tag, version_tags[version], 4);
27        return tag;
28    }
29    else
30        return 0;
31}
32
33
34enum lsquic_version
35lsquic_tag2ver (uint32_t ver_tag)
36{
37    unsigned n;
38    for (n = 0; n < sizeof(version_tags) / sizeof(version_tags[0]); ++n)
39        if (0 == memcmp(version_tags[n], &ver_tag, sizeof(ver_tag)))
40            return n;
41    return -1;
42}
43
44
45enum lsquic_version
46lsquic_str2ver (const char *str, size_t len)
47{
48    uint32_t tag;
49
50    if (len == sizeof(tag) && 'Q' == str[0])
51    {
52        memcpy(&tag, str, sizeof(tag));
53        return lsquic_tag2ver(tag);
54    }
55    else
56        return -1;
57}
58
59
60const char *const lsquic_ver2str[N_LSQVER] = {
61    [LSQVER_035] = "Q035",
62    [LSQVER_037] = "Q037",
63    [LSQVER_038] = "Q038",
64    [LSQVER_039] = "Q039",
65    [LSQVER_041] = "Q041",
66    [LSQVER_042] = "Q042",
67};
68
69
70int
71gen_ver_tags (unsigned char *buf, size_t bufsz, unsigned version_bitmask)
72{
73    unsigned n;
74    lsquic_ver_tag_t tag;
75    unsigned char *p = buf;
76    unsigned char *const pend = p + bufsz;
77    for (n = 0; version_bitmask; ++n)
78    {
79        if (version_bitmask & (1 << n))
80        {
81            if (p + 4 > pend)
82                return -1;
83            version_bitmask &= ~(1 << n);
84            tag = lsquic_ver2tag(n);
85            if (0 == tag)
86                return -1;
87            memcpy(p, &tag, 4);
88            p += 4;
89        }
90    }
91    return p - buf;
92}
93