Files
flock/pkg/routing/bird/config_fuzz_test.go
T
Donavan Fritz 71e584cf96 NodeConfig defaults + code-quality pass + fuzz tests + README
NodeConfig.Spec.Defaults adds per-node IPv6/IPv4 family defaults that pod
annotations can override; built-in baseline (v6=true, v4=false) still
applies when the field is omitted.

bird.Render now validates every operator-supplied value (peer addresses,
CIDRs, anycast IPs, source addresses) before templating — fuzz found a
peer address containing `}` produced unbalanced braces in bird.conf.
Failing input preserved as a regression seed.

Fuzz targets added for ParseAnnotations, ParseCNIArgs, HostIfaceName,
canonical, IPAM allocate sequences, embed.Embed, and bird.Render.
Hardened canonical/ipToU32 against nil and non-IPv4 inputs.

README rewritten for outside readers — quickstart, NodeConfig + annotation
reference with worked examples, anycast use cases, comparison vs Calico
and Cilium, requirements, limitations.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>
2026-04-25 09:25:45 -05:00

94 lines
3.2 KiB
Go

package bird
import (
"strings"
"testing"
)
// FuzzRender drives the bird template with a wide range of inputs and
// confirms two safety properties:
//
// 1. Render never panics.
// 2. On nil-error return, the output is deterministic (calling Render
// twice with the same input yields byte-identical output) and contains
// no unbalanced braces (a smoke test for malformed template branches).
func FuzzRender(f *testing.F) {
type seed struct {
routerID string
asn uint32
peerAddr string
peerASN uint32
cidr6 string
cidr4 string
anycast6 string
anycast4 string
localV6 string
localV4 string
}
seeds := []seed{
{routerID: "10.0.0.1", asn: 65101, peerAddr: "2001:db8::1", peerASN: 65000, cidr6: "2001:db8:f001::/64"},
{routerID: "172.25.25.101", asn: 65101, peerAddr: "172.25.25.1", peerASN: 65000, cidr4: "172.25.210.0/24"},
{routerID: "10.0.0.1", asn: 65101, peerAddr: "2001:db8::1", peerASN: 65000, cidr6: "2001:db8:f001::/64", anycast6: "2001:db8:a::1"},
{routerID: "10.0.0.1", asn: 65101, peerAddr: "10.0.0.2", peerASN: 65000, cidr4: "10.0.0.0/24", anycast4: "10.255.0.1"},
{routerID: "10.0.0.1", asn: 65101}, // no peer, no cidrs
{routerID: "", asn: 65101, peerAddr: "10.0.0.2", peerASN: 1}, // empty routerID → expect error
{routerID: "10.0.0.1", asn: 0, peerAddr: "10.0.0.2", peerASN: 1}, // zero ASN → expect error
// Backtick-bearing inputs to defend the template against accidental
// closure of the raw-string literal.
{routerID: "10.0.0.1`", asn: 65101},
// Newlines and template-meta in user-supplied addresses
{routerID: "10.0.0.1", asn: 65101, peerAddr: "2001:db8::1\n{{kaboom}}", peerASN: 65000, cidr6: "2001:db8:f001::/64"},
}
for _, s := range seeds {
f.Add(s.routerID, s.asn, s.peerAddr, s.peerASN, s.cidr6, s.cidr4, s.anycast6, s.anycast4, s.localV6, s.localV4)
}
f.Fuzz(func(t *testing.T, routerID string, asn uint32, peerAddr string, peerASN uint32, cidr6, cidr4, anycast6, anycast4, localV6, localV4 string) {
in := NodeBGP{
RouterID: routerID,
LocalASN: asn,
LocalV6: localV6,
LocalV4: localV4,
}
// Add the peer in whichever family it belongs to, if any. FamilyOf
// returns "" for non-IPs; that test exercises the "skip unknown
// family" branch in the bird agent code path.
if fam := FamilyOf(peerAddr); fam != "" {
in.Peers = []Peer{{Family: fam, Address: peerAddr, ASN: peerASN}}
}
if cidr6 != "" {
in.CIDR6 = []string{cidr6}
}
if cidr4 != "" {
in.CIDR4 = []string{cidr4}
}
if anycast6 != "" {
in.Anycast6 = []string{anycast6}
}
if anycast4 != "" {
in.Anycast4 = []string{anycast4}
}
out, err := Render(in)
if err != nil {
return
}
// Determinism.
out2, err := Render(in)
if err != nil {
t.Fatalf("Render became flaky: first ok, second %v", err)
}
if out != out2 {
t.Fatalf("Render not deterministic on identical input")
}
// Smoke test for balanced braces. The template uses `{` and `}`
// as BIRD's block delimiters; if our template engine ever
// produced an unbalanced output we'd catch it here.
if got := strings.Count(out, "{") - strings.Count(out, "}"); got != 0 {
t.Fatalf("unbalanced braces: %d", got)
}
})
}