Validate and cap ansible pagination params

internal/provider/ansible/ansible.go

@@ -9,6 +9,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/url"
+	"strconv"
 	"strings"
 
 	"git.unkin.net/unkin/artifactapi/internal/auth"
@@ -42,12 +43,27 @@ func (p *Provider) UpstreamURL(remote models.Remote, path string) string {
 	return strings.TrimRight(remote.BaseURL, "/") + "/" + strings.TrimLeft(path, "/")
 }
 
+const maxPageLimit = 100
+
 // ForwardedQuery keeps limit/offset pagination on metadata paths only.
-func (p *Provider) ForwardedQuery(path string) []string {
+func (p *Provider) ForwardedQuery(path string) map[string]provider.QueryValidator {
 	if isArtifact(path) {
 		return nil
 	}
-	return []string{"limit", "offset"}
+	return map[string]provider.QueryValidator{"limit": pageLimit, "offset": pageOffset}
+}
+
+func pageOffset(v string) (string, bool) {
+	n, err := strconv.ParseUint(v, 10, 32)
+	return strconv.FormatUint(n, 10), err == nil
+}
+
+func pageLimit(v string) (string, bool) {
+	n, err := strconv.ParseUint(v, 10, 32)
+	if err != nil || n == 0 {
+		return "", false
+	}
+	return strconv.FormatUint(min(n, maxPageLimit), 10), true
 }
 
 // RewriteResponse points href, download_url and links.* at the remote. Links

internal/provider/ansible/ansible_test.go

@@ -2,7 +2,6 @@ package ansible
 
 import (
 	"encoding/json"
-	"reflect"
 	"testing"
 
 	"git.unkin.net/unkin/artifactapi/internal/provider"
@@ -40,12 +39,39 @@ func TestContentTypeIgnoresQuery(t *testing.T) {
 
 func TestForwardedQuery(t *testing.T) {
 	p := &Provider{}
-	if got := p.ForwardedQuery("api/v3/collections/a/b/versions/"); !reflect.DeepEqual(got, []string{"limit", "offset"}) {
-		t.Errorf("metadata ForwardedQuery = %v", got)
-	}
 	if got := p.ForwardedQuery(tarball); got != nil {
 		t.Errorf("tarball ForwardedQuery = %v, want nil", got)
 	}
+	q := p.ForwardedQuery("api/v3/collections/a/b/versions/")
+	if len(q) != 2 || q["limit"] == nil || q["offset"] == nil {
+		t.Fatalf("metadata ForwardedQuery keys = %v, want limit and offset", q)
+	}
+	tests := []struct {
+		param, in, want string
+		ok              bool
+	}{
+		{"limit", "10", "10", true},
+		{"limit", "007", "7", true},
+		{"limit", "100", "100", true},
+		{"limit", "5000", "100", true},
+		{"limit", "0", "", false},
+		{"limit", "", "", false},
+		{"limit", "-1", "", false},
+		{"limit", "+5", "", false},
+		{"limit", "1e3", "", false},
+		{"limit", "10 ", "", false},
+		{"offset", "0", "0", true},
+		{"offset", "000", "0", true},
+		{"offset", "0100", "100", true},
+		{"offset", "abc", "", false},
+		{"offset", "99999999999999999999", "", false},
+	}
+	for _, tt := range tests {
+		got, ok := q[tt.param](tt.in)
+		if ok != tt.ok || (ok && got != tt.want) {
+			t.Errorf("%s(%q) = %q, %v, want %q, %v", tt.param, tt.in, got, ok, tt.want, tt.ok)
+		}
+	}
 }
 
 func rewrite(t *testing.T, remote models.Remote, body string) map[string]any {