this is cool and all but the tables don't render properly

netsplit/funcs_hostsplitter.go

@@ -1,14 +1,68 @@
 package netsplit
 
 import (
-	"go4.org/netipx"
+	`math/big`
+	`net`
 	"net/netip"
+
+	`github.com/projectdiscovery/mapcidr`
+	"go4.org/netipx"
 )
 
-// Split splits the network defined in a HostSplitter alongside its configuration and performs the subnetting.
+/*
+	Split splits the network defined in a HostSplitter alongside its configuration and performs the subnetting.
+	This strategy attempts to split the network into subnets of equal number of hosts.
+
+	remaining may or may not be nil depending on if the number of hosts can fit cleanly within equal network sizes on boundaries.
+
+	An ErrBadNumHosts will be returned if the number of hosts does not match the *addressable* range in a prefix.
+*/
 func (h *HostSplitter) Split() (nets []*netip.Prefix, remaining *netipx.IPSet, err error) {
 
-	// TODO
+	var tgt *big.Int
+	var hosts *big.Int
+	var sub netip.Prefix
+	var subPtr *netip.Prefix
+	var split []*net.IPNet
+	var ipsb *netipx.IPSetBuilder = new(netipx.IPSetBuilder)
+
+	if h == nil || h.NumberHosts == 0 || h.BaseSplitter == nil || h.network == nil {
+		return
+	}
+
+	if split, err = mapcidr.SplitIPNetByNumber(h.network, int(h.NumberHosts)); err != nil {
+		return
+	}
+
+	tgt = big.NewInt(0)
+	tgt.SetUint64(uint64(h.NumberHosts))
+
+	nets = make([]*netip.Prefix, len(split))
+	for idx, n := range split {
+		sub, _ = netipx.FromStdIPNet(n)
+		hosts = mapcidr.CountIPsInCIDR(false, false, n)
+		if hosts == nil || tgt.Cmp(hosts) != 0 {
+			err = &SplitErr{
+				Wrapped:            ErrBadNumHosts,
+				Nets:               nets,
+				Remaining:          remaining,
+				LastSubnet:         &sub,
+				RequestedPrefixLen: uint8(sub.Bits()),
+			}
+			ipsb.AddPrefix(sub)
+		} else {
+			subPtr = new(netip.Prefix)
+			*subPtr = sub
+			nets = append(nets, subPtr)
+		}
+
+		nets[idx] = new(netip.Prefix)
+		*nets[idx] = sub
+	}
+
+	if remaining, err = ipsb.IPSet(); err != nil {
+		return
+	}
 
 	return
 }