golib/cmd/check-ip/server.go
AJ ONeal b9295608db
feat(check-ip): accept IP args, require --serve or args
Positional args are IPs to check and print; at least one IP or --serve
must be provided. Refactor server.go: split handle into lookup + writeText
methods so main can reuse them.

geoip is no longer managed via dataset.Group — it's a single
atomic.Pointer[geoip.Databases]. The Fetcher (httpcache or PollFiles)
still drives refresh, but via an inline ticker in the serve branch that
fetches, reopens, and swaps.
2026-04-20 16:40:56 -06:00

121 lines
3.1 KiB
Go

package main
import (
"context"
"encoding/json"
"errors"
"fmt"
"io"
"log"
"net"
"net/http"
"strings"
"time"
"github.com/therootcompany/golib/net/geoip"
)
// Result is the JSON verdict for a single IP.
type Result struct {
IP string `json:"ip"`
Blocked bool `json:"blocked"`
BlockedInbound bool `json:"blocked_inbound"`
BlockedOutbound bool `json:"blocked_outbound"`
Geo geoip.Info `json:"geo,omitzero"`
}
// lookup builds a Result for ip against the currently loaded blocklists
// and GeoIP databases.
func (c *IPCheck) lookup(ip string) Result {
in := c.inbound.Value().Contains(ip)
out := c.outbound.Value().Contains(ip)
return Result{
IP: ip,
Blocked: in || out,
BlockedInbound: in,
BlockedOutbound: out,
Geo: c.geo.Load().Lookup(ip),
}
}
// writeText renders res as human-readable plain text.
func (c *IPCheck) writeText(w io.Writer, res Result) {
switch {
case res.BlockedInbound && res.BlockedOutbound:
fmt.Fprintf(w, "%s is BLOCKED (inbound + outbound)\n", res.IP)
case res.BlockedInbound:
fmt.Fprintf(w, "%s is BLOCKED (inbound)\n", res.IP)
case res.BlockedOutbound:
fmt.Fprintf(w, "%s is BLOCKED (outbound)\n", res.IP)
default:
fmt.Fprintf(w, "%s is allowed\n", res.IP)
}
var parts []string
if res.Geo.City != "" {
parts = append(parts, res.Geo.City)
}
if res.Geo.Region != "" {
parts = append(parts, res.Geo.Region)
}
if res.Geo.Country != "" {
parts = append(parts, fmt.Sprintf("%s (%s)", res.Geo.Country, res.Geo.CountryISO))
}
if len(parts) > 0 {
fmt.Fprintf(w, " Location: %s\n", strings.Join(parts, ", "))
}
if res.Geo.ASN != 0 {
fmt.Fprintf(w, " ASN: AS%d %s\n", res.Geo.ASN, res.Geo.ASNOrg)
}
}
func (c *IPCheck) handle(w http.ResponseWriter, r *http.Request) {
ip := strings.TrimSpace(r.URL.Query().Get("ip"))
if ip == "" {
if xff := r.Header.Get("X-Forwarded-For"); xff != "" {
first, _, _ := strings.Cut(xff, ",")
ip = strings.TrimSpace(first)
} else if host, _, err := net.SplitHostPort(r.RemoteAddr); err == nil {
ip = host
} else {
ip = r.RemoteAddr
}
}
res := c.lookup(ip)
if r.URL.Query().Get("format") == "json" ||
strings.Contains(r.Header.Get("Accept"), "application/json") {
w.Header().Set("Content-Type", "application/json; charset=utf-8")
enc := json.NewEncoder(w)
enc.SetIndent("", " ")
_ = enc.Encode(res)
return
}
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
c.writeText(w, res)
}
func (c *IPCheck) serve(ctx context.Context) error {
mux := http.NewServeMux()
mux.HandleFunc("GET /check", c.handle)
mux.HandleFunc("GET /{$}", c.handle)
srv := &http.Server{
Addr: c.Bind,
Handler: mux,
BaseContext: func(_ net.Listener) context.Context { return ctx },
}
go func() {
<-ctx.Done()
shutCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
_ = srv.Shutdown(shutCtx)
}()
log.Printf("listening on %s", c.Bind)
if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
return err
}
return nil
}