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
parent 677aec2a42
commit 71e584cf96
17 changed files with 1583 additions and 100 deletions
@@ -0,0 +1,93 @@
+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)
+		}
+	})
+}