swarm.go

package commands

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"path"
	"sort"
	"sync"
	"time"

	files "github.com/ipfs/go-ipfs-files"
	"github.com/ipfs/go-ipfs/commands"
	"github.com/ipfs/go-ipfs/config"
	"github.com/ipfs/go-ipfs/core/commands/cmdenv"
	"github.com/ipfs/go-ipfs/core/node/libp2p"
	"github.com/ipfs/go-ipfs/repo"
	"github.com/ipfs/go-ipfs/repo/fsrepo"

	cmds "github.com/ipfs/go-ipfs-cmds"
	inet "github.com/libp2p/go-libp2p-core/network"
	"github.com/libp2p/go-libp2p-core/peer"
	rcmgr "github.com/libp2p/go-libp2p-resource-manager"
	ma "github.com/multiformats/go-multiaddr"
	madns "github.com/multiformats/go-multiaddr-dns"
	mamask "github.com/whyrusleeping/multiaddr-filter"
)

const (
	dnsResolveTimeout = 10 * time.Second
)

type stringList struct {
	Strings []string
}

type addrMap struct {
	Addrs map[string][]string
}

var SwarmCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Interact with the swarm.",
		ShortDescription: `
'ipfs swarm' is a tool to manipulate the network swarm. The swarm is the
component that opens, listens for, and maintains connections to other
ipfs peers in the internet.
`,
	},
	Subcommands: map[string]*cmds.Command{
		"addrs":      swarmAddrsCmd,
		"connect":    swarmConnectCmd,
		"disconnect": swarmDisconnectCmd,
		"filters":    swarmFiltersCmd,
		"peers":      swarmPeersCmd,
		"peering":    swarmPeeringCmd,
		"stats":      swarmStatsCmd, // libp2p Network Resource Manager
		"limit":      swarmLimitCmd, // libp2p Network Resource Manager
	},
}

const (
	swarmVerboseOptionName   = "verbose"
	swarmStreamsOptionName   = "streams"
	swarmLatencyOptionName   = "latency"
	swarmDirectionOptionName = "direction"
)

type peeringResult struct {
	ID     peer.ID
	Status string
}

var swarmPeeringCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Modify the peering subsystem.",
		ShortDescription: `
'ipfs swarm peering' manages the peering subsystem. 
Peers in the peering subsystem is maintained to be connected, reconnected 
on disconnect with a back-off.
The changes are not saved to the config.
`,
	},
	Subcommands: map[string]*cmds.Command{
		"add": swarmPeeringAddCmd,
		"ls":  swarmPeeringLsCmd,
		"rm":  swarmPeeringRmCmd,
	},
}

var swarmPeeringAddCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Add peers into the peering subsystem.",
		ShortDescription: `
'ipfs swarm peering add' will add the new address to the peering subsystem as one that should always be connected to.
`,
	},
	Arguments: []cmds.Argument{
		cmds.StringArg("address", true, true, "address of peer to add into the peering subsystem"),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		addrs := make([]ma.Multiaddr, len(req.Arguments))

		for i, arg := range req.Arguments {
			addr, err := ma.NewMultiaddr(arg)
			if err != nil {
				return err
			}

			addrs[i] = addr
		}

		addInfos, err := peer.AddrInfosFromP2pAddrs(addrs...)
		if err != nil {
			return err
		}

		node, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}

		for _, addrinfo := range addInfos {
			node.Peering.AddPeer(addrinfo)
			err = res.Emit(peeringResult{addrinfo.ID, "success"})
			if err != nil {
				return err
			}
		}
		return nil
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(func(req *cmds.Request, w io.Writer, pr *peeringResult) error {
			fmt.Fprintf(w, "add %s %s\n", pr.ID.String(), pr.Status)
			return nil
		}),
	},
	Type: peeringResult{},
}

var swarmPeeringLsCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "List peers registered in the peering subsystem.",
		ShortDescription: `
'ipfs swarm peering ls' lists the peers that are registered in the peering subsystem and to which the daemon is always connected.
`,
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		node, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}
		peers := node.Peering.ListPeers()
		return cmds.EmitOnce(res, addrInfos{Peers: peers})
	},
	Type: addrInfos{},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(func(req *cmds.Request, w io.Writer, ai *addrInfos) error {
			for _, info := range ai.Peers {
				fmt.Fprintf(w, "%s\n", info.ID)
				for _, addr := range info.Addrs {
					fmt.Fprintf(w, "\t%s\n", addr)
				}
			}
			return nil
		}),
	},
}

type addrInfos struct {
	Peers []peer.AddrInfo
}

var swarmPeeringRmCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Remove a peer from the peering subsystem.",
		ShortDescription: `
'ipfs swarm peering rm' will remove the given ID from the peering subsystem and remove it from the always-on connection.
`,
	},
	Arguments: []cmds.Argument{
		cmds.StringArg("ID", true, true, "ID of peer to remove from the peering subsystem"),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		node, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}

		for _, arg := range req.Arguments {
			id, err := peer.Decode(arg)
			if err != nil {
				return err
			}

			node.Peering.RemovePeer(id)
			if err = res.Emit(peeringResult{id, "success"}); err != nil {
				return err
			}
		}
		return nil
	},
	Type: peeringResult{},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(func(req *cmds.Request, w io.Writer, pr *peeringResult) error {
			fmt.Fprintf(w, "add %s %s\n", pr.ID.String(), pr.Status)
			return nil
		}),
	},
}

var swarmPeersCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "List peers with open connections.",
		ShortDescription: `
'ipfs swarm peers' lists the set of peers this node is connected to.
`,
	},
	Options: []cmds.Option{
		cmds.BoolOption(swarmVerboseOptionName, "v", "display all extra information"),
		cmds.BoolOption(swarmStreamsOptionName, "Also list information about open streams for each peer"),
		cmds.BoolOption(swarmLatencyOptionName, "Also list information about latency to each peer"),
		cmds.BoolOption(swarmDirectionOptionName, "Also list information about the direction of connection"),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		api, err := cmdenv.GetApi(env, req)
		if err != nil {
			return err
		}

		verbose, _ := req.Options[swarmVerboseOptionName].(bool)
		latency, _ := req.Options[swarmLatencyOptionName].(bool)
		streams, _ := req.Options[swarmStreamsOptionName].(bool)
		direction, _ := req.Options[swarmDirectionOptionName].(bool)

		conns, err := api.Swarm().Peers(req.Context)
		if err != nil {
			return err
		}

		var out connInfos
		for _, c := range conns {
			ci := connInfo{
				Addr: c.Address().String(),
				Peer: c.ID().Pretty(),
			}

			if verbose || direction {
				// set direction
				ci.Direction = c.Direction()
			}

			if verbose || latency {
				lat, err := c.Latency()
				if err != nil {
					return err
				}

				if lat == 0 {
					ci.Latency = "n/a"
				} else {
					ci.Latency = lat.String()
				}
			}
			if verbose || streams {
				strs, err := c.Streams()
				if err != nil {
					return err
				}

				for _, s := range strs {
					ci.Streams = append(ci.Streams, streamInfo{Protocol: string(s)})
				}
			}
			sort.Sort(&ci)
			out.Peers = append(out.Peers, ci)
		}

		sort.Sort(&out)
		return cmds.EmitOnce(res, &out)
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(func(req *cmds.Request, w io.Writer, ci *connInfos) error {
			pipfs := ma.ProtocolWithCode(ma.P_IPFS).Name
			for _, info := range ci.Peers {
				fmt.Fprintf(w, "%s/%s/%s", info.Addr, pipfs, info.Peer)
				if info.Latency != "" {
					fmt.Fprintf(w, " %s", info.Latency)
				}

				if info.Direction != inet.DirUnknown {
					fmt.Fprintf(w, " %s", directionString(info.Direction))
				}
				fmt.Fprintln(w)

				for _, s := range info.Streams {
					if s.Protocol == "" {
						s.Protocol = "<no protocol name>"
					}

					fmt.Fprintf(w, "  %s\n", s.Protocol)
				}
			}

			return nil
		}),
	},
	Type: connInfos{},
}

var swarmStatsCmd = &cmds.Command{
	Status: cmds.Experimental,
	Helptext: cmds.HelpText{
		Tagline: "Report resource usage for a scope.",
		LongDescription: `Report resource usage for a scope.
The scope can be one of the following:
- system        -- reports the system aggregate resource usage.
- transient     -- reports the transient resource usage.
- svc:<service> -- reports the resource usage of a specific service.
- proto:<proto> -- reports the resource usage of a specific protocol.
- peer:<peer>   -- reports the resource usage of a specific peer.
- all           -- reports the resource usage for all currently active scopes.

The output of this command is JSON.
`},
	Arguments: []cmds.Argument{
		cmds.StringArg("scope", true, false, "scope of the stat report"),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		node, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}

		if node.ResourceManager == nil {
			return libp2p.NoResourceMgrError
		}

		if len(req.Arguments) != 1 {
			return fmt.Errorf("must specify exactly one scope")
		}
		scope := req.Arguments[0]
		result, err := libp2p.NetStat(node.ResourceManager, scope)
		if err != nil {
			return err
		}

		b := new(bytes.Buffer)
		enc := json.NewEncoder(b)
		err = enc.Encode(result)
		if err != nil {
			return err
		}
		return cmds.EmitOnce(res, b)
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: HumanJSONEncoder,
	},
}

var swarmLimitCmd = &cmds.Command{
	Status: cmds.Experimental,
	Helptext: cmds.HelpText{
		Tagline: "Get or set resource limits for a scope.",
		LongDescription: `Get or set resource limits for a scope.
The scope can be one of the following:
- system        -- limits for the system aggregate resource usage.
- transient     -- limits for the transient resource usage.
- svc:<service> -- limits for the resource usage of a specific service.
- proto:<proto> -- limits for the resource usage of a specific protocol.
- peer:<peer>   -- limits for the resource usage of a specific peer.

The output of this command is JSON.

It is possible to use this command to inspect and tweak limits at runtime:

	$ ipfs swarm limit system > limit.json
	$ vi limit.json
	$ ipfs swarm limit system limit.json

Changes made via command line are discarded on node shutdown.
For permanent limits set Swarm.ResourceMgr.Limits in the $IPFS_PATH/config file.
`},
	Arguments: []cmds.Argument{
		cmds.StringArg("scope", true, false, "scope of the limit"),
		cmds.FileArg("limit.json", false, false, "limits to be set").EnableStdin(),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		node, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}

		if node.ResourceManager == nil {
			return libp2p.NoResourceMgrError
		}

		scope := req.Arguments[0]

		//  set scope limit to new values (when limit.json is passed as a second arg)
		if req.Files != nil {
			var newLimit rcmgr.BasicLimitConfig
			it := req.Files.Entries()
			if it.Next() {
				file := files.FileFromEntry(it)
				if file == nil {
					return errors.New("expected a JSON file")
				}
				if err := json.NewDecoder(file).Decode(&newLimit); err != nil {
					return errors.New("failed to decode JSON as ResourceMgrScopeConfig")
				}
				return libp2p.NetSetLimit(node.ResourceManager, node.Repo, scope, newLimit)
			}
			if err := it.Err(); err != nil {
				return fmt.Errorf("error opening limit JSON file: %w", err)
			}
		}

		// get scope limit
		result, err := libp2p.NetLimit(node.ResourceManager, scope)
		if err != nil {
			return err
		}

		b := new(bytes.Buffer)
		enc := json.NewEncoder(b)
		err = enc.Encode(result)
		if err != nil {
			return err
		}
		return cmds.EmitOnce(res, b)
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: HumanJSONEncoder,
	},
}

type streamInfo struct {
	Protocol string
}

type connInfo struct {
	Addr      string
	Peer      string
	Latency   string
	Muxer     string
	Direction inet.Direction
	Streams   []streamInfo
}

func (ci *connInfo) Less(i, j int) bool {
	return ci.Streams[i].Protocol < ci.Streams[j].Protocol
}

func (ci *connInfo) Len() int {
	return len(ci.Streams)
}

func (ci *connInfo) Swap(i, j int) {
	ci.Streams[i], ci.Streams[j] = ci.Streams[j], ci.Streams[i]
}

type connInfos struct {
	Peers []connInfo
}

func (ci connInfos) Less(i, j int) bool {
	return ci.Peers[i].Addr < ci.Peers[j].Addr
}

func (ci connInfos) Len() int {
	return len(ci.Peers)
}

func (ci connInfos) Swap(i, j int) {
	ci.Peers[i], ci.Peers[j] = ci.Peers[j], ci.Peers[i]
}

// directionString transfers to string
func directionString(d inet.Direction) string {
	switch d {
	case inet.DirInbound:
		return "inbound"
	case inet.DirOutbound:
		return "outbound"
	default:
		return ""
	}
}

var swarmAddrsCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "List known addresses. Useful for debugging.",
		ShortDescription: `
'ipfs swarm addrs' lists all addresses this node is aware of.
`,
	},
	Subcommands: map[string]*cmds.Command{
		"local":  swarmAddrsLocalCmd,
		"listen": swarmAddrsListenCmd,
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		api, err := cmdenv.GetApi(env, req)
		if err != nil {
			return err
		}

		addrs, err := api.Swarm().KnownAddrs(req.Context)
		if err != nil {
			return err
		}

		out := make(map[string][]string)
		for p, paddrs := range addrs {
			s := p.Pretty()
			for _, a := range paddrs {
				out[s] = append(out[s], a.String())
			}
		}

		return cmds.EmitOnce(res, &addrMap{Addrs: out})
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(func(req *cmds.Request, w io.Writer, am *addrMap) error {
			// sort the ids first
			ids := make([]string, 0, len(am.Addrs))
			for p := range am.Addrs {
				ids = append(ids, p)
			}
			sort.Strings(ids)

			for _, p := range ids {
				paddrs := am.Addrs[p]
				fmt.Fprintf(w, "%s (%d)\n", p, len(paddrs))
				for _, addr := range paddrs {
					fmt.Fprintf(w, "\t"+addr+"\n")
				}
			}

			return nil
		}),
	},
	Type: addrMap{},
}

var swarmAddrsLocalCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "List local addresses.",
		ShortDescription: `
'ipfs swarm addrs local' lists all local listening addresses announced to the network.
`,
	},
	Options: []cmds.Option{
		cmds.BoolOption("id", "Show peer ID in addresses."),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		api, err := cmdenv.GetApi(env, req)
		if err != nil {
			return err
		}

		showid, _ := req.Options["id"].(bool)
		self, err := api.Key().Self(req.Context)
		if err != nil {
			return err
		}

		maddrs, err := api.Swarm().LocalAddrs(req.Context)
		if err != nil {
			return err
		}

		var addrs []string
		p2pProtocolName := ma.ProtocolWithCode(ma.P_P2P).Name
		for _, addr := range maddrs {
			saddr := addr.String()
			if showid {
				saddr = path.Join(saddr, p2pProtocolName, self.ID().Pretty())
			}
			addrs = append(addrs, saddr)
		}
		sort.Strings(addrs)
		return cmds.EmitOnce(res, &stringList{addrs})
	},
	Type: stringList{},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(safeTextListEncoder),
	},
}

var swarmAddrsListenCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "List interface listening addresses.",
		ShortDescription: `
'ipfs swarm addrs listen' lists all interface addresses the node is listening on.
`,
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		api, err := cmdenv.GetApi(env, req)
		if err != nil {
			return err
		}

		var addrs []string
		maddrs, err := api.Swarm().ListenAddrs(req.Context)
		if err != nil {
			return err
		}

		for _, addr := range maddrs {
			addrs = append(addrs, addr.String())
		}
		sort.Strings(addrs)

		return cmds.EmitOnce(res, &stringList{addrs})
	},
	Type: stringList{},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(safeTextListEncoder),
	},
}

var swarmConnectCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Open connection to a given address.",
		ShortDescription: `
'ipfs swarm connect' opens a new direct connection to a peer address.

The address format is an IPFS multiaddr:

ipfs swarm connect /ip4/104.131.131.82/tcp/4001/p2p/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ
`,
	},
	Arguments: []cmds.Argument{
		cmds.StringArg("address", true, true, "Address of peer to connect to.").EnableStdin(),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		node, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}

		api, err := cmdenv.GetApi(env, req)
		if err != nil {
			return err
		}

		addrs := req.Arguments

		pis, err := parseAddresses(req.Context, addrs, node.DNSResolver)
		if err != nil {
			return err
		}

		output := make([]string, len(pis))
		for i, pi := range pis {
			output[i] = "connect " + pi.ID.Pretty()

			err := api.Swarm().Connect(req.Context, pi)
			if err != nil {
				return fmt.Errorf("%s failure: %s", output[i], err)
			}
			output[i] += " success"
		}

		return cmds.EmitOnce(res, &stringList{output})
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(safeTextListEncoder),
	},
	Type: stringList{},
}

var swarmDisconnectCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Close connection to a given address.",
		ShortDescription: `
'ipfs swarm disconnect' closes a connection to a peer address. The address
format is an IPFS multiaddr:

ipfs swarm disconnect /ip4/104.131.131.82/tcp/4001/p2p/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ

The disconnect is not permanent; if ipfs needs to talk to that address later,
it will reconnect.
`,
	},
	Arguments: []cmds.Argument{
		cmds.StringArg("address", true, true, "Address of peer to disconnect from.").EnableStdin(),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		node, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}

		api, err := cmdenv.GetApi(env, req)
		if err != nil {
			return err
		}

		addrs, err := parseAddresses(req.Context, req.Arguments, node.DNSResolver)
		if err != nil {
			return err
		}

		output := make([]string, 0, len(addrs))
		for _, ainfo := range addrs {
			maddrs, err := peer.AddrInfoToP2pAddrs(&ainfo)
			if err != nil {
				return err
			}
			// FIXME: This will print:
			//
			//   disconnect QmFoo success
			//   disconnect QmFoo success
			//   ...
			//
			// Once per address specified. However, I'm not sure of
			// a good backwards compat solution. Right now, I'm just
			// preserving the current behavior.
			for _, addr := range maddrs {
				msg := "disconnect " + ainfo.ID.Pretty()
				if err := api.Swarm().Disconnect(req.Context, addr); err != nil {
					msg += " failure: " + err.Error()
				} else {
					msg += " success"
				}
				output = append(output, msg)
			}
		}
		return cmds.EmitOnce(res, &stringList{output})
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(safeTextListEncoder),
	},
	Type: stringList{},
}

// parseAddresses is a function that takes in a slice of string peer addresses
// (multiaddr + peerid) and returns a slice of properly constructed peers
func parseAddresses(ctx context.Context, addrs []string, rslv *madns.Resolver) ([]peer.AddrInfo, error) {
	// resolve addresses
	maddrs, err := resolveAddresses(ctx, addrs, rslv)
	if err != nil {
		return nil, err
	}

	return peer.AddrInfosFromP2pAddrs(maddrs...)
}

// resolveAddresses resolves addresses parallelly
func resolveAddresses(ctx context.Context, addrs []string, rslv *madns.Resolver) ([]ma.Multiaddr, error) {
	ctx, cancel := context.WithTimeout(ctx, dnsResolveTimeout)
	defer cancel()

	var maddrs []ma.Multiaddr
	var wg sync.WaitGroup
	resolveErrC := make(chan error, len(addrs))

	maddrC := make(chan ma.Multiaddr)

	for _, addr := range addrs {
		maddr, err := ma.NewMultiaddr(addr)
		if err != nil {
			return nil, err
		}

		// check whether address ends in `ipfs/Qm...`
		if _, last := ma.SplitLast(maddr); last.Protocol().Code == ma.P_IPFS {
			maddrs = append(maddrs, maddr)
			continue
		}
		wg.Add(1)
		go func(maddr ma.Multiaddr) {
			defer wg.Done()
			raddrs, err := rslv.Resolve(ctx, maddr)
			if err != nil {
				resolveErrC <- err
				return
			}
			// filter out addresses that still doesn't end in `ipfs/Qm...`
			found := 0
			for _, raddr := range raddrs {
				if _, last := ma.SplitLast(raddr); last != nil && last.Protocol().Code == ma.P_IPFS {
					maddrC <- raddr
					found++
				}
			}
			if found == 0 {
				resolveErrC <- fmt.Errorf("found no ipfs peers at %s", maddr)
			}
		}(maddr)
	}
	go func() {
		wg.Wait()
		close(maddrC)
	}()

	for maddr := range maddrC {
		maddrs = append(maddrs, maddr)
	}

	select {
	case err := <-resolveErrC:
		return nil, err
	default:
	}

	return maddrs, nil
}

var swarmFiltersCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Manipulate address filters.",
		ShortDescription: `
'ipfs swarm filters' will list out currently applied filters. Its subcommands
can be used to add or remove said filters. Filters are specified using the
multiaddr-filter format:

Example:

    /ip4/192.168.0.0/ipcidr/16

Where the above is equivalent to the standard CIDR:

    192.168.0.0/16

Filters default to those specified under the "Swarm.AddrFilters" config key.
`,
	},
	Subcommands: map[string]*cmds.Command{
		"add": swarmFiltersAddCmd,
		"rm":  swarmFiltersRmCmd,
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		n, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}

		if n.PeerHost == nil {
			return ErrNotOnline
		}

		var output []string
		for _, f := range n.Filters.FiltersForAction(ma.ActionDeny) {
			s, err := mamask.ConvertIPNet(&f)
			if err != nil {
				return err
			}
			output = append(output, s)
		}
		return cmds.EmitOnce(res, &stringList{output})
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(safeTextListEncoder),
	},
	Type: stringList{},
}

var swarmFiltersAddCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Add an address filter.",
		ShortDescription: `
'ipfs swarm filters add' will add an address filter to the daemons swarm.
`,
	},
	Arguments: []cmds.Argument{
		cmds.StringArg("address", true, true, "Multiaddr to filter.").EnableStdin(),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		n, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}

		if n.PeerHost == nil {
			return ErrNotOnline
		}

		if len(req.Arguments) == 0 {
			return errors.New("no filters to add")
		}

		r, err := fsrepo.Open(env.(*commands.Context).ConfigRoot)
		if err != nil {
			return err
		}
		defer r.Close()
		cfg, err := r.Config()
		if err != nil {
			return err
		}

		for _, arg := range req.Arguments {
			mask, err := mamask.NewMask(arg)
			if err != nil {
				return err
			}

			n.Filters.AddFilter(*mask, ma.ActionDeny)
		}

		added, err := filtersAdd(r, cfg, req.Arguments)
		if err != nil {
			return err
		}

		return cmds.EmitOnce(res, &stringList{added})
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(safeTextListEncoder),
	},
	Type: stringList{},
}

var swarmFiltersRmCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline: "Remove an address filter.",
		ShortDescription: `
'ipfs swarm filters rm' will remove an address filter from the daemons swarm.
`,
	},
	Arguments: []cmds.Argument{
		cmds.StringArg("address", true, true, "Multiaddr filter to remove.").EnableStdin(),
	},
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		n, err := cmdenv.GetNode(env)
		if err != nil {
			return err
		}

		if n.PeerHost == nil {
			return ErrNotOnline
		}

		r, err := fsrepo.Open(env.(*commands.Context).ConfigRoot)
		if err != nil {
			return err
		}
		defer r.Close()
		cfg, err := r.Config()
		if err != nil {
			return err
		}

		if req.Arguments[0] == "all" || req.Arguments[0] == "*" {
			fs := n.Filters.FiltersForAction(ma.ActionDeny)
			for _, f := range fs {
				n.Filters.RemoveLiteral(f)
			}

			removed, err := filtersRemoveAll(r, cfg)
			if err != nil {
				return err
			}

			return cmds.EmitOnce(res, &stringList{removed})
		}

		for _, arg := range req.Arguments {
			mask, err := mamask.NewMask(arg)
			if err != nil {
				return err
			}

			n.Filters.RemoveLiteral(*mask)
		}

		removed, err := filtersRemove(r, cfg, req.Arguments)
		if err != nil {
			return err
		}

		return cmds.EmitOnce(res, &stringList{removed})
	},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(safeTextListEncoder),
	},
	Type: stringList{},
}

func filtersAdd(r repo.Repo, cfg *config.Config, filters []string) ([]string, error) {
	addedMap := map[string]struct{}{}
	addedList := make([]string, 0, len(filters))

	// re-add cfg swarm filters to rm dupes
	oldFilters := cfg.Swarm.AddrFilters
	cfg.Swarm.AddrFilters = nil

	// add new filters
	for _, filter := range filters {
		if _, found := addedMap[filter]; found {
			continue
		}

		cfg.Swarm.AddrFilters = append(cfg.Swarm.AddrFilters, filter)
		addedList = append(addedList, filter)
		addedMap[filter] = struct{}{}
	}

	// add back original filters. in this order so that we output them.
	for _, filter := range oldFilters {
		if _, found := addedMap[filter]; found {
			continue
		}

		cfg.Swarm.AddrFilters = append(cfg.Swarm.AddrFilters, filter)
		addedMap[filter] = struct{}{}
	}

	if err := r.SetConfig(cfg); err != nil {
		return nil, err
	}

	return addedList, nil
}

func filtersRemoveAll(r repo.Repo, cfg *config.Config) ([]string, error) {
	removed := cfg.Swarm.AddrFilters
	cfg.Swarm.AddrFilters = nil

	if err := r.SetConfig(cfg); err != nil {
		return nil, err
	}

	return removed, nil
}

func filtersRemove(r repo.Repo, cfg *config.Config, toRemoveFilters []string) ([]string, error) {
	removed := make([]string, 0, len(toRemoveFilters))
	keep := make([]string, 0, len(cfg.Swarm.AddrFilters))

	oldFilters := cfg.Swarm.AddrFilters

	for _, oldFilter := range oldFilters {
		found := false
		for _, toRemoveFilter := range toRemoveFilters {
			if oldFilter == toRemoveFilter {
				found = true
				removed = append(removed, toRemoveFilter)
				break
			}
		}

		if !found {
			keep = append(keep, oldFilter)
		}
	}
	cfg.Swarm.AddrFilters = keep

	if err := r.SetConfig(cfg); err != nil {
		return nil, err
	}

	return removed, nil
}