pkg/cloudflare: Implement Cloudflare IP list checks

1 files changed, 52 insertions, 0 deletions

diff --git a/pkg/cloudflare/iplist_generate.go b/pkg/cloudflare/iplist_generate.go
new file mode 100644
index 0000000..7e169c4
--- /dev/null
+++ b/pkg/cloudflare/iplist_generate.go
@@ -0,0 +1,52 @@
+//go:build generate
+// +build generate
+
+package main
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"go/format"
+	"net/netip"
+	"os"
+	"time"
+	_ "unsafe"
+
+	"github.com/pg9182/atlas/pkg/cloudflare"
+)
+
+//go:linkname iplist github.com/pg9182/atlas/pkg/cloudflare.iplist
+var iplist []netip.Prefix
+
+func main() {
+	if err := cloudflare.UpdateIPs(context.Background()); err != nil {
+		fmt.Fprintf(os.Stderr, "error: fetch ip list: %v\n", err)
+		os.Exit(1)
+	}
+
+	var b bytes.Buffer
+	fmt.Fprintf(&b, "// Code generated by iplist_generate on %s; DO NOT EDIT.\n", time.Now().UTC())
+	fmt.Fprintf(&b, "\n\n")
+	fmt.Fprintf(&b, "package cloudflare\n")
+	fmt.Fprintf(&b, "\n\n")
+	fmt.Fprintf(&b, "import %#v\n", "net/netip")
+	fmt.Fprintf(&b, "\n\n")
+	fmt.Fprintf(&b, "//go:generate go run iplist_generate.go\n")
+	fmt.Fprintf(&b, "\n\n")
+	fmt.Fprintf(&b, "func init() {\n")
+	fmt.Fprintf(&b, "iplist = append(iplist,\n")
+	for _, p := range iplist {
+		fmt.Fprintf(&b, "netip.MustParsePrefix(%#v),\n", p.String())
+	}
+	fmt.Fprintf(&b, ")\n")
+	fmt.Fprintf(&b, "}\n")
+
+	if src, err := format.Source(b.Bytes()); err != nil {
+		fmt.Fprintf(os.Stderr, "error: format generated code: %v\n", err)
+		os.Exit(1)
+	} else if err = os.WriteFile("iplist_generated.go", src, 0666); err != nil {
+		fmt.Fprintf(os.Stderr, "error: write generated code: %v\n", err)
+		os.Exit(1)
+	}
+}