lsquic_version.c revision 052a1c28 
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_039] = { 'Q', '0', '3', '9', },
13    [LSQVER_041] = { 'Q', '0', '4', '1', },
14    [LSQVER_043] = { 'Q', '0', '4', '3', },
15};
16
17
18uint32_t
19lsquic_ver2tag (unsigned version)
20{
21    lsquic_ver_tag_t tag;
22    if (version < N_LSQVER)
23    {
24        memcpy(&tag, version_tags[version], 4);
25        return tag;
26    }
27    else
28        return 0;
29}
30
31
32enum lsquic_version
33lsquic_tag2ver (uint32_t ver_tag)
34{
35    unsigned n;
36    for (n = 0; n < sizeof(version_tags) / sizeof(version_tags[0]); ++n)
37        if (0 == memcmp(version_tags[n], &ver_tag, sizeof(ver_tag)))
38            return n;
39    return -1;
40}
41
42
43enum lsquic_version
44lsquic_str2ver (const char *str, size_t len)
45{
46    uint32_t tag;
47
48    if (len == sizeof(tag) && 'Q' == str[0])
49    {
50        memcpy(&tag, str, sizeof(tag));
51        return lsquic_tag2ver(tag);
52    }
53    else
54        return -1;
55}
56
57
58const char *const lsquic_ver2str[N_LSQVER] = {
59    [LSQVER_035] = "Q035",
60    [LSQVER_039] = "Q039",
61    [LSQVER_041] = "Q041",
62    [LSQVER_043] = "Q043",
63};
64
65
66int
67gen_ver_tags (unsigned char *buf, size_t bufsz, unsigned version_bitmask)
68{
69    unsigned n;
70    lsquic_ver_tag_t tag;
71    unsigned char *p = buf;
72    unsigned char *const pend = p + bufsz;
73    for (n = 0; version_bitmask; ++n)
74    {
75        if (version_bitmask & (1 << n))
76        {
77            if (p + 4 > pend)
78                return -1;
79            version_bitmask &= ~(1 << n);
80            tag = lsquic_ver2tag(n);
81            if (0 == tag)
82                return -1;
83            memcpy(p, &tag, 4);
84            p += 4;
85        }
86    }
87    return p - buf;
88}
89