p2p/dnsdisc: add implementation of EIP-1459 (#20094)

This adds an implementation of node discovery via DNS TXT records to the
go-ethereum library. The implementation doesn't match EIP-1459 exactly,
the main difference being that this implementation uses separate merkle
trees for tree links and ENRs. The EIP will be updated to match p2p/dnsdisc.

To maintain DNS trees, cmd/devp2p provides a frontend for the p2p/dnsdisc
library. The new 'dns' subcommands can be used to create, sign and deploy DNS
discovery trees.

vendor/github.com/cloudflare/cloudflare-go/lockdown.go

@@ -0,0 +1,151 @@
+package cloudflare
+
+import (
+	"encoding/json"
+	"net/url"
+	"strconv"
+
+	"github.com/pkg/errors"
+)
+
+// ZoneLockdown represents a Zone Lockdown rule. A rule only permits access to
+// the provided URL pattern(s) from the given IP address(es) or subnet(s).
+type ZoneLockdown struct {
+	ID             string               `json:"id"`
+	Description    string               `json:"description"`
+	URLs           []string             `json:"urls"`
+	Configurations []ZoneLockdownConfig `json:"configurations"`
+	Paused         bool                 `json:"paused"`
+	Priority       int                  `json:"priority,omitempty"`
+}
+
+// ZoneLockdownConfig represents a Zone Lockdown config, which comprises
+// a Target ("ip" or "ip_range") and a Value (an IP address or IP+mask,
+// respectively.)
+type ZoneLockdownConfig struct {
+	Target string `json:"target"`
+	Value  string `json:"value"`
+}
+
+// ZoneLockdownResponse represents a response from the Zone Lockdown endpoint.
+type ZoneLockdownResponse struct {
+	Result ZoneLockdown `json:"result"`
+	Response
+	ResultInfo `json:"result_info"`
+}
+
+// ZoneLockdownListResponse represents a response from the List Zone Lockdown
+// endpoint.
+type ZoneLockdownListResponse struct {
+	Result []ZoneLockdown `json:"result"`
+	Response
+	ResultInfo `json:"result_info"`
+}
+
+// CreateZoneLockdown creates a Zone ZoneLockdown rule for the given zone ID.
+//
+// API reference: https://api.cloudflare.com/#zone-ZoneLockdown-create-a-ZoneLockdown-rule
+func (api *API) CreateZoneLockdown(zoneID string, ld ZoneLockdown) (*ZoneLockdownResponse, error) {
+	uri := "/zones/" + zoneID + "/firewall/lockdowns"
+	res, err := api.makeRequest("POST", uri, ld)
+	if err != nil {
+		return nil, errors.Wrap(err, errMakeRequestError)
+	}
+
+	response := &ZoneLockdownResponse{}
+	err = json.Unmarshal(res, &response)
+	if err != nil {
+		return nil, errors.Wrap(err, errUnmarshalError)
+	}
+
+	return response, nil
+}
+
+// UpdateZoneLockdown updates a Zone ZoneLockdown rule (based on the ID) for the
+// given zone ID.
+//
+// API reference: https://api.cloudflare.com/#zone-ZoneLockdown-update-ZoneLockdown-rule
+func (api *API) UpdateZoneLockdown(zoneID string, id string, ld ZoneLockdown) (*ZoneLockdownResponse, error) {
+	uri := "/zones/" + zoneID + "/firewall/lockdowns/" + id
+	res, err := api.makeRequest("PUT", uri, ld)
+	if err != nil {
+		return nil, errors.Wrap(err, errMakeRequestError)
+	}
+
+	response := &ZoneLockdownResponse{}
+	err = json.Unmarshal(res, &response)
+	if err != nil {
+		return nil, errors.Wrap(err, errUnmarshalError)
+	}
+
+	return response, nil
+}
+
+// DeleteZoneLockdown deletes a Zone ZoneLockdown rule (based on the ID) for the
+// given zone ID.
+//
+// API reference: https://api.cloudflare.com/#zone-ZoneLockdown-delete-ZoneLockdown-rule
+func (api *API) DeleteZoneLockdown(zoneID string, id string) (*ZoneLockdownResponse, error) {
+	uri := "/zones/" + zoneID + "/firewall/lockdowns/" + id
+	res, err := api.makeRequest("DELETE", uri, nil)
+	if err != nil {
+		return nil, errors.Wrap(err, errMakeRequestError)
+	}
+
+	response := &ZoneLockdownResponse{}
+	err = json.Unmarshal(res, &response)
+	if err != nil {
+		return nil, errors.Wrap(err, errUnmarshalError)
+	}
+
+	return response, nil
+}
+
+// ZoneLockdown retrieves a Zone ZoneLockdown rule (based on the ID) for the
+// given zone ID.
+//
+// API reference: https://api.cloudflare.com/#zone-ZoneLockdown-ZoneLockdown-rule-details
+func (api *API) ZoneLockdown(zoneID string, id string) (*ZoneLockdownResponse, error) {
+	uri := "/zones/" + zoneID + "/firewall/lockdowns/" + id
+	res, err := api.makeRequest("GET", uri, nil)
+	if err != nil {
+		return nil, errors.Wrap(err, errMakeRequestError)
+	}
+
+	response := &ZoneLockdownResponse{}
+	err = json.Unmarshal(res, &response)
+	if err != nil {
+		return nil, errors.Wrap(err, errUnmarshalError)
+	}
+
+	return response, nil
+}
+
+// ListZoneLockdowns retrieves a list of Zone ZoneLockdown rules for a given
+// zone ID by page number.
+//
+// API reference: https://api.cloudflare.com/#zone-ZoneLockdown-list-ZoneLockdown-rules
+func (api *API) ListZoneLockdowns(zoneID string, page int) (*ZoneLockdownListResponse, error) {
+	v := url.Values{}
+	if page <= 0 {
+		page = 1
+	}
+
+	v.Set("page", strconv.Itoa(page))
+	v.Set("per_page", strconv.Itoa(100))
+	query := "?" + v.Encode()
+
+	uri := "/zones/" + zoneID + "/firewall/lockdowns" + query
+	res, err := api.makeRequest("GET", uri, nil)
+	if err != nil {
+		return nil, errors.Wrap(err, errMakeRequestError)
+	}
+
+	response := &ZoneLockdownListResponse{}
+	err = json.Unmarshal(res, &response)
+	if err != nil {
+		return nil, errors.Wrap(err, errUnmarshalError)
+	}
+
+	return response, nil
+}