v0.2.5

ADDED:
* num-addrs subcommand, to get the number of hosts/addresses in a given
  prefix length
* get-net subcommand, to more easily get a single subnet from either the
  beginning or the end of a prefix. (MUCH FASTER than CIDR-splitting!)

cmd/subnetter/args.go

@@ -2,11 +2,13 @@ package main
 
 type Args struct {
 	Version         verArgs         `command:"version" alias:"v" description:"Show version information." validate:"omitempty"`
-	SplitCIDR       SplitCIDRArgs   `command:"split-cidr" alias:"sc" description:"Split a network into as many equal subnets of prefix size N as possible." validate:"omitempty"`
+	GetPfx          GetPfxArgs      `command:"get-net" alias:"gn" description:"Get a single subnet from a network at either the beginning or end. (You'll probably want to enable -r/--no-remaining.)" validate:"omitempty"`
+	SplitCIDR       SplitCIDRArgs   `command:"split-cidr" alias:"sc" description:"Split a network into as many equal subnets of prefix size N as possible. (This may have issues/take a very long time if you are splitting a very large network into many very small subnets.)" validate:"omitempty"`
 	SplitHost       SplitHostArgs   `command:"split-hosts" alias:"sh" description:"Split a network into N total number of hosts *per subnet* as cleanly/evenly as possible." validate:"omitempty"`
 	SplitSubnets    SplitSubnetArgs `command:"split-nets" alias:"sn" description:"Split a network into N number of subnets as cleanly as possible." validate:"omitempty"`
 	VLSM            VLSMArgs        `command:"split-vlsm" alias:"sv" alias:"vlsm" description:"Use VLSM (Variable-Length Subnet Masks) to split a network into differently sized subnets." validate:"omitempty"`
 	ExplicitNetwork XNetArgs        `command:"net" alias:"xn" alias:"net" description:"Print information about an explicit network address." validate:"omitempty"`
+	NumAddrs        NAddrArgs       `command:"num-addrs" alias:"na" alias:"addrs" description:"Return the number of addresses/hosts in a given network size. (This saves needing to lookup from the table subcommand.)" validate:"omitempty"`
 	NumNets         NNetArgs        `command:"num-nets" alias:"nn" alias:"nets" description:"Return the number of subnets of a given size that can fit into a given network size. This is MUCH, MUCH FASTER than splitting (if you do not need addressing)." validate:"omitempty"`
 	Parse           ParseArgs       `command:"parse" alias:"p" alias:"read" alias:"convert" description:"Parse/convert output from a previous subnetter run." validate:"omitempty"`
 	Table           TableArgs       `command:"table" alias:"t" alias:"tab" alias:"tbl" description:"Show prefix summaries (by default both IPv4 and IPv6)." validate:"omitempty"`
@@ -49,6 +51,21 @@ type cacheArgs struct {
 	DoResCache bool   `short:"c" long:"cache-reservations" env:"SBNTR_RSVCACHE" description:"Enable caching/cache lookup for reservation data."`
 }
 
+type GetPfxArgs struct {
+	Position string `short:"P" long:"position" choice:"first" choice:"last" default:"first" description:"The position of the subnet within the network." validate:"required,oneof=first last"`
+	Prefix   uint8  `short:"s" long:"size" required:"true" description:"Prefix length/network size in bits (as CIDR number)." validate:"required"`
+	splitArgs
+}
+
+type NAddrArgs struct {
+	Isv6          bool `short:"6" long:"v6" description:"If the prefix given is <=32, specify this flag to indicate that it is an IPv6 prefix and not IPv4. (If it is >32, it is automatically treated as an IPv6 prefix for obvious reasons.)"`
+	InclNetAddr   bool `short:"N" long:"incl-net" description:"If specified, include the network address in the count."`
+	InclBcastAddr bool `short:"B" long:"incl-bcast" description:"If specified, include the broadcast/reserved broadcast address in the count."`
+	Size          struct {
+		PrefixSize uint8 `positional-arg-name:"<prefix length>" required:"1" validate:"lte=128"`
+	} `positional-args:"yes" required:"1" validate:"required"`
+}
+
 type NNetArgs struct {
 	Verbose   bool `short:"v" long:"verbose" description:"Be verbose (more ideal for logging)."`
 	NoV6Check bool `short:"6" long:"no-v6" description:"If specified, do not indicate if the subnetting is IPv6 only (true) or not (false; dual-stack/IPv4 supported)."`

cmd/subnetter/funcs.go

@@ -15,7 +15,6 @@ import (
 	"time"
 
 	"github.com/goccy/go-yaml"
-	"github.com/projectdiscovery/mapcidr"
 	"go4.org/netipx"
 	"r00t2.io/subnetter/netsplit"
 	"r00t2.io/subnetter/version"
@@ -159,8 +158,8 @@ func printMask(label string, pfx netip.Prefix, verb, indent int, indentStr strin
 	fmt.Fprintf(sb, "%sBits:\t\t%d\n", pre2, pfx.Bits())
 	fmt.Fprintf(sb, "%sFirst:\t\t%s\n", pre2, first.String())
 	fmt.Fprintf(sb, "%sLast:\t\t%s\n", pre2, last.String())
-	fmt.Fprintf(sb, "%sAddresses:\t%d\n", pre2, mapcidr.CountIPsInCIDR(true, true, netipx.PrefixIPNet(pfx.Masked())))
-	fmt.Fprintf(sb, "%sHosts:\t\t%d\n", pre2, mapcidr.CountIPsInCIDR(false, false, netipx.PrefixIPNet(pfx.Masked())))
+	fmt.Fprintf(sb, "%sAddresses:\t%d\n", pre2, netsplit.NumAddrsPfx(pfx.Masked(), true, true))
+	fmt.Fprintf(sb, "%sHosts:\t\t%d\n", pre2, netsplit.NumAddrsPfx(pfx.Masked(), false, false))
 	if verb >= 2 {
 		fmt.Fprintf(sb, "%sExpanded:\t%s\n", pre2, netsplit.MaskExpand(mask, pfx.Addr().Is6()))
 		fmt.Fprintf(sb, "%sHex:\t\t0x%s\n", pre2, mask.String())

cmd/subnetter/funcs_tpl.go

@@ -10,7 +10,6 @@ import (
 	`strings`
 
 	`github.com/TwiN/go-color`
-	`github.com/projectdiscovery/mapcidr`
 	`go4.org/netipx`
 	`r00t2.io/subnetter/netsplit`
 )
@@ -423,8 +422,8 @@ func tplTablePrefixes(ipVer uint8, indent string, plain bool) (out string, err e
 			return
 		}
 		dummyNet = netipx.PrefixIPNet(rows[idx].NetPrefix.Masked())
-		rows[idx].Addresses = mapcidr.CountIPsInCIDR(true, true, dummyNet)
-		rows[idx].Hosts = mapcidr.CountIPsInCIDR(false, false, dummyNet)
+		rows[idx].Addresses = netsplit.NumAddrsNet(dummyNet, true, true)
+		rows[idx].Hosts = netsplit.NumAddrsNet(dummyNet, false, false)
 	}
 
 	colFields, colTitles, colSizes = sizeStructs(rows)

cmd/subnetter/main.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	`math/big`
 	"net"
 	"net/netip"
 	"os"
@@ -34,6 +35,7 @@ func main() {
 	var buf *bytes.Buffer
 	var res *netsplit.StructuredResults
 	var numNets uint
+	var numAddrs *big.Int
 	var v6Only bool
 	var noStrict bool
 	var strictErr error
@@ -84,6 +86,18 @@ func main() {
 			log.Panicln(err)
 		}
 		return
+	case "num-addrs":
+		if err = validate.Struct(args.NumAddrs); err != nil {
+			log.Panicln(err)
+		}
+		if args.NumAddrs.Size.PrefixSize > 32 {
+			args.NumAddrs.Isv6 = true
+		}
+		if numAddrs, err = netsplit.NumAddrsIn(args.NumAddrs.Size.PrefixSize, args.NumAddrs.Isv6, args.NumAddrs.InclNetAddr, args.NumAddrs.InclBcastAddr); err != nil {
+			log.Panicln(err)
+		}
+		fmt.Println(numAddrs.String())
+		return
 	case "num-nets":
 		if err = validate.Struct(args.NumNets); err != nil {
 			log.Panicln(err)
@@ -195,6 +209,18 @@ func main() {
 			These are all handily-dandily enclosed in a `common` struct type.
 		*/
 		switch parser.Active.Name {
+		case "get-net": // Not a *true* splitter, per se; splitting is required but only for functional reasons.
+			if err = validate.Struct(args.GetPfx); err != nil {
+				log.Panicln(err)
+			}
+			cmnArgs = args.GetPfx.common
+			splitter = &netsplit.PrefixGetter{
+				Pos:          args.GetPfx.Position,
+				PrefixLength: args.GetPfx.Prefix,
+				BaseSplitter: new(netsplit.BaseSplitter),
+			}
+			noStrict = false
+			strictErr = netsplit.ErrBadNumHosts // dummy
 		case "split-hosts":
 			if err = validate.Struct(args.SplitHost); err != nil {
 				log.Panicln(err)