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deps: remove iplib in favor of net/netip #2466

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deps: remove iplib in favor of net/netip #2466

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ac27614
deps: remove iplib
kotakanbe Mar 17, 2026
1d879a8
Merge branch 'master' into diet-iplib
kotakanbe Mar 17, 2026
04d3d5f
Merge branch 'master' into diet-iplib
kotakanbe Mar 17, 2026
4f42493
Merge branch 'master' into diet-iplib
kotakanbe Mar 24, 2026
c35f046
fix: address Copilot review on iplib removal
Mar 24, 2026
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36 changes: 19 additions & 17 deletions config/tomlloader.go
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Original file line number Diff line number Diff line change
Expand Up @@ -4,13 +4,13 @@ import (
"fmt"
"maps"
"net"
"net/netip"
"regexp"
"runtime"
"slices"
"strings"

"github.com/BurntSushi/toml"
"github.com/c-robinson/iplib"
"github.com/knqyf263/go-cpe/naming"
"golang.org/x/xerrors"

Expand Down Expand Up @@ -193,27 +193,29 @@ func enumerateHosts(host string) ([]string, error) {
return []string{host}, nil
}

ipAddr, ipNet, err := net.ParseCIDR(host)
prefix, err := netip.ParsePrefix(host)
if err != nil {
return nil, xerrors.Errorf("Failed to parse CIDR. err: %w", err)
}
maskLen, _ := ipNet.Mask.Size()

addrs := []string{}
if net.ParseIP(ipAddr.String()).To4() != nil {
n := iplib.NewNet4(ipAddr, int(maskLen))
for _, addr := range n.Enumerate(int(n.Count()), 0) {
addrs = append(addrs, addr.String())
}
} else if net.ParseIP(ipAddr.String()).To16() != nil {
n := iplib.NewNet6(ipAddr, int(maskLen), 0)
if !n.Count().IsInt64() {
return nil, xerrors.Errorf("Failed to enumerate IP address. err: mask bitsize too big")
}
for _, addr := range n.Enumerate(int(n.Count().Int64()), 0) {
addrs = append(addrs, addr.String())
}
hostBits := prefix.Addr().BitLen() - prefix.Bits()
if hostBits > 63 {
return nil, xerrors.Errorf("Failed to enumerate IP address. err: mask bitsize too big")
}

count := uint64(1) << hostBits
addrs := make([]string, 0, count)
addr := prefix.Masked().Addr()

Copilot AI Mar 24, 2026

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count is a uint64, but make([]string, 0, count) requires an int capacity/length (per Go spec). As written this won’t compile (or will require an implicit conversion that Go doesn’t do). Convert count to int after checking it fits in math.MaxInt (and adjust the loop accordingly).

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@kotakanbe kotakanbe Mar 24, 2026

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Fixed in c35f046. Changed count from uint64 to int so make([]string, 0, count) receives the correct type directly. Additionally, the hard upper bound was tightened from 2^63 to 2^16 host bits, which guarantees count always fits comfortably in an int on any platform.

for range count {
addrs = append(addrs, addr.String())
addr = addr.Next()
}
Comment on lines +201 to +215

Copilot AI Mar 24, 2026

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This enumerates 1<<hostBits addresses and also preallocates the slice to that size. For inputs like IPv4 /0 (hostBits=32) or IPv6 /65 (hostBits=63), this will attempt to allocate/enumerate billions to quintillions of entries and will reliably OOM/hang. Consider adding a hard upper bound on the number of hosts that can be expanded (or at least reject prefixes where count exceeds a reasonable limit / math.MaxInt) to avoid config-triggered resource exhaustion.

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@kotakanbe kotakanbe Mar 24, 2026

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Fixed in c35f046. Tightened the upper bound from 2^63 to 2^16 host bits (maxHostBits = 16), so the maximum enumerable range is now a /16 for IPv4 (65,536 addresses) or /112 for IPv6. Wider prefixes like /0 or /8 now return an error immediately instead of attempting a huge allocation. Added test cases for 10.0.0.0/0 and 192.168.0.0/8 to verify.


// IPv4 with prefix < 31: strip network (first) and broadcast (last) addresses
if prefix.Addr().Is4() && prefix.Bits() < 31 && len(addrs) > 2 {
addrs = addrs[1 : len(addrs)-1]
}

return addrs, nil
}

Expand Down
30 changes: 30 additions & 0 deletions config/tomlloader_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,36 @@ func TestHosts(t *testing.T) {
}
}

func TestEnumerateHosts(t *testing.T) {
t.Parallel()
tests := []struct {
in string
expected []string
err bool
}{
{in: "192.168.1.1", expected: []string{"192.168.1.1"}},
{in: "ssh/host", expected: []string{"ssh/host"}},
{in: "192.168.1.0/30", expected: []string{"192.168.1.1", "192.168.1.2"}},
{in: "192.168.1.0/31", expected: []string{"192.168.1.0", "192.168.1.1"}},
{in: "192.168.1.1/32", expected: []string{"192.168.1.1"}},
{in: "2001:db8::1/126", expected: []string{"2001:db8::", "2001:db8::1", "2001:db8::2", "2001:db8::3"}},
{in: "2001:db8::1/127", expected: []string{"2001:db8::", "2001:db8::1"}},
{in: "2001:db8::1/128", expected: []string{"2001:db8::1"}},
{in: "2001:db8::1/32", err: true},
}
for i, tt := range tests {
actual, err := enumerateHosts(tt.in)
if err != nil && !tt.err {
t.Errorf("[%d] unexpected error: %v", i, err)
} else if err == nil && tt.err {
t.Errorf("[%d] expected error but got none", i)
}
if !reflect.DeepEqual(actual, tt.expected) {
t.Errorf("[%d] in: %s, got: %q, want: %q", i, tt.in, actual, tt.expected)
}
}
}

func TestToCpeURI(t *testing.T) {
var tests = []struct {
in string
Expand Down
1 change: 0 additions & 1 deletion go.mod
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Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,6 @@ require (
github.com/aws/aws-sdk-go-v2/credentials v1.19.10
github.com/aws/aws-sdk-go-v2/service/s3 v1.96.2
github.com/aws/aws-sdk-go-v2/service/sts v1.41.7
github.com/c-robinson/iplib v1.0.8
github.com/cenkalti/backoff v2.2.1+incompatible
github.com/d4l3k/messagediff v1.2.2-0.20190829033028-7e0a312ae40b
github.com/emersion/go-sasl v0.0.0-20241020182733-b788ff22d5a6
Expand Down
2 changes: 0 additions & 2 deletions go.sum
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Original file line number Diff line number Diff line change
Expand Up @@ -202,8 +202,6 @@ github.com/bshuster-repo/logrus-logstash-hook v1.0.0 h1:e+C0SB5R1pu//O4MQ3f9cFuP
github.com/bshuster-repo/logrus-logstash-hook v1.0.0/go.mod h1:zsTqEiSzDgAa/8GZR7E1qaXrhYNDKBYy5/dWPTIflbk=
github.com/bytecodealliance/wasmtime-go/v39 v39.0.1 h1:RibaT47yiyCRxMOj/l2cvL8cWiWBSqDXHyqsa9sGcCE=
github.com/bytecodealliance/wasmtime-go/v39 v39.0.1/go.mod h1:miR4NYIEBXeDNamZIzpskhJ0z/p8al+lwMWylQ/ZJb4=
github.com/c-robinson/iplib v1.0.8 h1:exDRViDyL9UBLcfmlxxkY5odWX5092nPsQIykHXhIn4=
github.com/c-robinson/iplib v1.0.8/go.mod h1:i3LuuFL1hRT5gFpBRnEydzw8R6yhGkF4szNDIbF8pgo=
github.com/cenkalti/backoff v2.2.1+incompatible h1:tNowT99t7UNflLxfYYSlKYsBpXdEet03Pg2g16Swow4=
github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
github.com/cenkalti/backoff/v4 v4.3.0 h1:MyRJ/UdXutAwSAT+s3wNd7MfTIcy71VQueUuFK343L8=
Expand Down
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