SNMP 将表示日期时间的字符串转换为日期和时间 octetstr

Question

我试图在 snmp 中发出日期时间， 据我了解，DateAndTime 字符串是一个 11 字节的字符串，代表这种格式的值：（1 个字母 -> 1 个字节）
y -> 年
米 -> 月
d -> 天
小时 -> 小时
M -> 分钟
s -> 第二
u -> 1/10 秒
^ -> + 或 - 用于时区偏移
H -> 时区偏移量（小时）
N -> 时区偏移量（分钟）

yymdhMsu^HN

//Array encoding the date: 2022-11-10 12:30:15.11 UTC + 01:33
   uint8_t BFF[11];
        BFF[0] = 22;
        BFF[1] = 20;
        //-
        BFF[2] = 11;
        //-
        BFF[3] = 10;
        //,
        BFF[4] = 12;
        //:
        BFF[5] = 30;
        //:
        BFF[6] = 15;
        //.
        BFF[7] = 11;
        //,
        BFF[8] = '+';
        BFF[9] = 1;
        //:
        BFF[10] = 33;
        BFF[11] = '\0';

如何将其转换为 SNMP++ OctetStr？

Answer 1

它不是“1 个字母 -> 1 个字节”。在定义https://www.rfc-editor.org/rfc/rfc2579.html 时给出的示例与“DISPLAY-HINT”对比中，有 11 个字节（可能是 8 个）并且没有“字母”。取而代之的是 1 个两字节十进制字段、8 个一字节十进制字段和 1 个 1 字节 ASCII 字段。共有 25 个字符，但您的结果可能会有所不同。：

"2d-1d-1d,1d:1d:1d.1d,1a1d:1d"  EXAMPLE in DESCRIPTION
"1992-5-26,13:30:15.0,-4:0"     "DISPLAY-HINT"

供参考的整个 RFC 部分以及两个相关的勘误表如下所示：

. （这是目前的互联网标准，但自 ~1999 年以来一直存在

TimeInterval ::= TEXTUAL-CONVENTION
    STATUS       current
    DESCRIPTION
            "A period of time, measured in units of 0.01 seconds."
    SYNTAX       INTEGER (0..2147483647)

DateAndTime ::= TEXTUAL-CONVENTION
    DISPLAY-HINT "2d-1d-1d,1d:1d:1d.1d,1a1d:1d"
    STATUS       current
    DESCRIPTION
            "A date-time specification.

            field  octets  contents                  range
            -----  ------  --------                  -----
              1      1-2   year*                     0..65536
              2       3    month                     1..12
              3       4    day                       1..31
              4       5    hour                      0..23
              5       6    minutes                   0..59
              6       7    seconds                   0..60
                           (use 60 for leap-second)
              7       8    deci-seconds              0..9
              8       9    direction from UTC        '+' / '-'
              9      10    hours from UTC*           0..13
             10      11    minutes from UTC          0..59

            * Notes:
            - the value of year is in network-byte order
            - daylight saving time in New Zealand is +13

            For example, Tuesday May 26, 1992 at 1:30:15 PM EDT would be
            displayed as:

                             1992-5-26,13:30:15.0,-4:0


McCloghrie, et al.          Standards Track                    [Page 18]

RFC 2579             Textual Conventions for SMIv2            April 1999


            Note that if only local time is known, then timezone
            information (fields 8-10) is not present."
    SYNTAX       OCTET STRING (SIZE (8 | 11))

请注意，此 RFC 有 2 个相关勘误表：

Errata ID: 417
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Juergen Schoenwaelder
Date Reported: 2001-07-31
Section 2 says:

RFC 2579 lists an invalid range for the year in the DateAndTime TC:

            field  octets  contents                  range
            -----  ------  --------                  -----
              1      1-2   year*                     0..65536
It should say:

            field  octets  contents                  range
            -----  ------  --------                  -----
              1      1-2   year*                     0..65535

Errata ID: 416
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Juergen Schoenwaelder
Date Reported: 2004-07-27
The DateAndTime textual convention did not originally define a special value which can be used in situations where a DateAndTime value is unknown or for some other reason not available. Several MIB modules on the IETF standards-track use the value '0000

              2       3    month                     1..12
              3       4    day                       1..31
It should say:

              2       3    month                 0 | 1..12
              3       4    day                   0 | 1..31