dsh-ipcalc
IP & subnet math toolbox for DeepSeek Harness (dsh).
Seven pure-math tools — zero runtime dependencies, no network I/O — so agents stop doing
subnet arithmetic in their heads (where they frequently get it wrong).
Tools
| Tool | What it does |
|---|
ipv4_subnet | Full subnet layout for an IPv4 CIDR: network, broadcast, netmask, wildcard, host range, address counts, integer forms and IANA classes |
ipv4_summarize | Reduce a list of IPv4 addresses/ranges to the minimal covering CIDR list (merge + supernet) |
ipv4_split | Split an IPv4 CIDR into equal network-aligned subnets — by part count (power of two) or by target prefix — for VLSM planning |
ipv4_range | Turn an arbitrary address range (start … end) into the minimal covering CIDR list — the inverse of summarizing |
ip_parse | Validate, normalize (RFC 5952) and classify any IPv4/IPv6 address, including embedded IPv4-in-IPv6 forms |
ipv6_subnet | Full subnet layout for an IPv6 CIDR: network, first/last host, exact address counts (128-bit BigInt math) and IANA class |
ip_match | Membership test: is a bare IP (IPv4 or IPv6) inside a CIDR range? Reports the normalized range too |
Install
dsh plugin --profile <your-profile> add github:TYEclipse/dsh-ipcalc
Usage
ipv4_subnet("192.168.1.25/24")
→ network 192.168.1.0/24
netmask 255.255.255.0 wildcard 0.0.0.255 broadcast 192.168.1.255
host range 192.168.1.1 – 192.168.1.254 (254 usable of 256)
classes: network=private host=private
ipv4_subnet("10.10.10.10/255.255.255.248") # dotted-mask input works too
→ network 10.10.10.8/29 (6 usable hosts)
ipv4_summarize(["10.0.0.0/24", "10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"])
→ ["10.0.0.0/22"]
ipv4_split("10.0.0.0/24", parts=4)
→ 4 × /26 subnets, 62 usable hosts each
10.0.0.0/26 10.0.0.64/26 10.0.0.128/26 10.0.0.192/26
ipv4_split("192.168.0.0/22", prefix=24)
→ 4 × /24 subnets, 254 usable hosts each
ipv4_range("10.0.5.3", "10.0.9.200")
→ 13 CIDR(s) covering 1222 address(es)
10.0.5.3/32 10.0.5.4/30 10.0.5.8/29 … 10.0.9.192/29 10.0.9.200/32
ip_parse("::ffff:192.168.1.1")
→ IPv6, class ipv4_mapped, normalized ::ffff:c0a8:101 (embeds 192.168.1.1)
ipv6_subnet("2001:db8:1234:5678::1/64")
→ network 2001:db8:1234:5678::/64
range 2001:db8:1234:5678::1 – 2001:db8:1234:5678:ffff:ffff:ffff:fffe
(18446744073709551614 usable of 18446744073709551616)
class documentation full 2001:0db8:1234:5678:0000:0000:0000:0000
ipv6_subnet("::/0")
→ network ::/0
range ::1 – ffff:ffff:ffff:ffff:ffff:ffff:ffff:fffe
(340282366920938463463374607431768211454 usable of 340282366920938463463374607431768211456)
class unspecified full 0000:0000:0000:0000:0000:0000:0000:0000
ipv6_subnet("fe80::1/127")
→ network fe80::/127
range fe80:: – fe80::1 (2 usable of 2)
class link_local full fe80:0000:0000:0000:0000:0000:0000:0000
note: RFC 6164: both addresses are usable on point-to-point links
ip_match("192.168.1.5", "192.168.1.0/24")
→ 192.168.1.5 is INSIDE 192.168.1.0/24 (IPv4)
network 192.168.1.0 – 192.168.1.255
ip_match("2001:db8::5", "2001:db8::/32")
→ 2001:db8::5 is INSIDE 2001:db8::/32 (IPv6)
network 2001:db8:: – 2001:db8:ffff:ffff:ffff:ffff:ffff:ffff
Semantics
- Exact arithmetic — IPv4 math uses plain double arithmetic on 32-bit integers
(values up to 2³² are exactly representable), so there is no bitwise-overflow risk.
IPv6 subnet math uses 128-bit
BigInt, so every boundary and count is exact;
address counts are returned as decimal strings because they exceed Number.MAX_SAFE_INTEGER.
- /31 follows RFC 3021 — both addresses are reported as usable (point-to-point links).
- /32 is a single host — first/last host equal the address itself.
- IPv6 /127 follows RFC 6164 — both addresses usable on point-to-point links;
IPv6 /128 is a single host.
- Bare addresses are treated as
/32 (IPv4) or /128 (IPv6); dotted netmasks
(/255.255.255.248) are accepted anywhere an IPv4 prefix length is; non-contiguous
masks are rejected.
- RFC 5952 canonicalization — IPv6 is lowercased, leading zeros stripped, and the
longest (leftmost on ties) run of two or more zero hextets compressed to
::.
- Classification follows the IANA special-purpose registries:
IPv4
unspecified / broadcast / loopback / private (10/8, 172.16/12, 192.168/16) / cgnat (100.64/10) / link_local (169.254/16) / documentation (192.0.2/24, 198.51.100/24, 203.0.113/24) / multicast (224/4) / reserved (240/4) / global;
IPv6 unspecified / loopback / ipv4_mapped / ipv4_compatible / documentation (2001:db8::/32) / link_local (fe80::/10) / multicast (ff00::/8) / unique_local (fc00::/7) / global.
Classification is best-effort for the common registry entries, not a full
CIDR-overlap engine.
ip_match rejects mixed versions — testing an IPv4 address against an IPv6
CIDR (or vice versa) returns valid: false with an explanatory reason instead
of a silently wrong answer.ipv4_split stays aligned and bounded — host bits are masked away first, the
target prefix must be longer than the source prefix, and one call returns at most
256 subnets (ask for a shorter prefix, or split the sub-ranges in turn). /31
subnets report 2 usable hosts per RFC 3021, /32 subnets report 1.ipv4_range covers exactly the requested range — the block list is minimal
(no oversized approximation), start must not be greater than end, and both ends
must be bare addresses (CIDR notation is rejected with a reason).
Development
pnpm install
pnpm build
pnpm test
pnpm lint
License
MIT
dsh-ipcalc（中文简介）
面向 DeepSeek Harness 的 IP 与子网数学工具箱，五个纯本地计算工具，零运行时依赖、无任何网络访问：
ipv4_subnet：给定 CIDR（支持 a.b.c.d/前缀、点分掩码、裸地址）输出完整子网布局——网络号、广播地址、子网掩码、反掩码、可用主机范围与数量、整数形式、IANA 分类（私网/环回/链路本地/CGNAT/文档段/组播/保留段等）。ipv4_summarize：把一组 IPv4 地址/网段归并成最小覆盖 CIDR 列表（相邻合并 + 对齐超网）。ipv4_split：把 IPv4 CIDR 等分成网络对齐的子网——按份数（必须是 2 的幂）或按目标前缀；输出每个子网的 CIDR 与地址/可用主机数，供 VLSM 规划使用（单次上限 256 个子网）。ipv4_range：把任意地址区间（起始地址到结束地址）转成最小覆盖 CIDR 列表——summarize 的逆运算，用于把「10.0.5.3 到 10.0.9.200」这类区间变成精确的 ACL 规则，而不是用一条过大的网段近似。ip_parse：校验、规范化（RFC 5952）并分类任意 IPv4/IPv6 地址，识别 ::ffff:a.b.c.d 内嵌 IPv4 形式。ipv6_subnet：IPv6 子网计算——128 位 BigInt 精确算术，输出网络地址、首末可用主机、精确地址数（十进制字符串，超出 2⁵³ 不失真）、RFC 5952 规范形与 IANA 分类；/127 遵循 RFC 6164（点对点两地址均可用）、/128 视为单主机。ip_match：判定裸 IP（v4/v6）是否属于某 CIDR 网段，并给出规范化网段范围；版本错配（v4 对 v6）明确报因，绝不静默出错。
专门解决大模型心算子网边界常出错的问题；/31 遵循 RFC 3021，/32 视为单主机。
