lsquic_version.c revision 4051ae3a 
1/* Copyright (c) 2017 - 2020 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#if _MSC_VER
9#include "vc_compat.h"
10#endif
11
12
13static const unsigned char version_tags[N_LSQVER][4] =
14{
15    [LSQVER_043] = { 'Q', '0', '4', '3', },
16    [LSQVER_046] = { 'Q', '0', '4', '6', },
17    [LSQVER_050] = { 'Q', '0', '5', '0', },
18#if LSQUIC_USE_Q098
19    [LSQVER_098] = { 'Q', '0', '9', '8', },
20#endif
21    [LSQVER_ID27] = { 0xFF, 0, 0, 27, },
22    [LSQVER_ID28] = { 0xFF, 0, 0, 28, },
23    [LSQVER_ID29] = { 0xFF, 0, 0, 29, },
24    [LSQVER_VERNEG] = { 0xFA, 0xFA, 0xFA, 0xFA, },
25};
26
27
28uint32_t
29lsquic_ver2tag (unsigned version)
30{
31    lsquic_ver_tag_t tag;
32    if (version < N_LSQVER)
33    {
34        memcpy(&tag, version_tags[version], 4);
35        return tag;
36    }
37    else
38        return 0;
39}
40
41
42enum lsquic_version
43lsquic_tag2ver (uint32_t ver_tag)
44{
45    unsigned n;
46    for (n = 0; n < sizeof(version_tags) / sizeof(version_tags[0]); ++n)
47        if (0 == memcmp(version_tags[n], &ver_tag, sizeof(ver_tag)))
48            return n;
49    return -1;
50}
51
52
53const char *const lsquic_ver2str[N_LSQVER] = {
54    [LSQVER_043] = "Q043",
55    [LSQVER_046] = "Q046",
56    [LSQVER_050] = "Q050",
57#if LSQUIC_USE_Q098
58    [LSQVER_098] = "Q098",
59#endif
60    [LSQVER_ID27] = "FF00001B",
61    [LSQVER_ID28] = "FF00001C",
62    [LSQVER_ID29] = "FF00001D",
63    [LSQVER_VERNEG] = "FAFAFAFA",
64};
65
66
67enum lsquic_version
68lsquic_str2ver (const char *str, size_t len)
69{
70    enum lsquic_version ver;
71    uint32_t tag;
72
73    if (len == sizeof(tag) && 'Q' == str[0])
74    {
75        memcpy(&tag, str, sizeof(tag));
76        return lsquic_tag2ver(tag);
77    }
78
79    for (ver = 0; ver < N_LSQVER; ++ver)
80        if (strlen(lsquic_ver2str[ver]) == len
81            && strncasecmp(lsquic_ver2str[ver], str, len) == 0)
82        {
83            return ver;
84        }
85
86    return -1;
87}
88
89
90int
91lsquic_gen_ver_tags (unsigned char *buf, size_t bufsz, unsigned version_bitmask)
92{
93    unsigned n;
94    lsquic_ver_tag_t tag;
95    unsigned char *p = buf;
96    unsigned char *const pend = p + bufsz;
97    for (n = 0; version_bitmask; ++n)
98    {
99        if (version_bitmask & (1 << n))
100        {
101            if (p + 4 > pend)
102                return -1;
103            version_bitmask &= ~(1 << n);
104            tag = lsquic_ver2tag(n);
105            if (0 == tag)
106                return -1;
107            memcpy(p, &tag, 4);
108            p += 4;
109        }
110    }
111    return p - buf;
112}
113