hid: port MODE, STATS, LINKS, KILL

Now all the commands have been ported but we desperately need to parse
a configuration file for additional settings yet.

hid/main.go

@@ -18,6 +18,7 @@ package main
 
 import (
 	"bufio"
+	"bytes"
 	"crypto/sha256"
 	"crypto/tls"
 	"encoding/hex"
@@ -45,6 +46,11 @@ const (
 	projectVersion = "0"
 )
 
+// TODO: Consider using time.Time directly instead of storing Unix epoch
+// timestamps with nanosecond precision. Despite carrying unnecessary timezone
+// information, it also carries a monotonic reading of the time, which allows
+// for more precise measurement of time differences.
+
 // --- Utilities ---------------------------------------------------------------
 
 // Split a string by a set of UTF-8 delimiters, optionally ignoring empty items.
@@ -316,8 +322,6 @@ const (
 	ircMaxMessageLength = 510
 )
 
-// TODO: Port the IRC token validation part as needed.
-
 const reClassSpecial = "\\[\\]\\\\`_^{|}"
 
 var (
@@ -330,6 +334,9 @@ var (
 	reUsername = regexp.MustCompile(`^[^\0\r\n @]+$`)
 
 	reChannelName = regexp.MustCompile(`^[^\0\7\r\n ,:]+$`)
+	reKey         = regexp.MustCompile(`^[^\r\n\f\t\v ]{1,23}$`)
+	reUserMask    = regexp.MustCompile(`^[^!@]+![^!@]+@[^@!]+$`)
+	reFingerprint = regexp.MustCompile(`^[a-fA-F0-9]{64}$`)
 )
 
 func ircIsValidNickname(nickname string) bool {
@@ -346,6 +353,19 @@ func ircIsValidChannelName(name string) bool {
 	return len(name) <= ircMaxChannelName && reChannelName.MatchString(name)
 }
 
+func ircIsValidKey(key string) bool {
+	// XXX: Should be 7-bit as well but whatever.
+	return reKey.MatchString(key)
+}
+
+func ircIsValidUserMask(mask string) bool {
+	return reUserMask.MatchString(mask)
+}
+
+func ircIsValidFingerprint(fp string) bool {
+	return reFingerprint.MatchString(fp)
+}
+
 // --- Clients (equals users) --------------------------------------------------
 
 type connCloseWrite interface {
@@ -356,7 +376,7 @@ type connCloseWrite interface {
 const ircSupportedUserModes = "aiwros"
 
 const (
-	ircUserModeInvisible = 1 << iota
+	ircUserModeInvisible uint = 1 << iota
 	ircUserModeRxWallops
 	ircUserModeRestricted
 	ircUserModeOperator
@@ -364,7 +384,7 @@ const (
 )
 
 const (
-	ircCapMultiPrefix = 1 << iota
+	ircCapMultiPrefix uint = 1 << iota
 	ircCapInviteNotify
 	ircCapEchoMessage
 	ircCapUserhostInNames
@@ -417,7 +437,7 @@ type client struct {
 const ircSupportedChanModes = "ov" + "beI" + "imnqpst" + "kl"
 
 const (
-	ircChanModeInviteOnly = 1 << iota
+	ircChanModeInviteOnly uint = 1 << iota
 	ircChanModeModerated
 	ircChanModeNoOutsideMsgs
 	ircChanModeQuiet
@@ -447,11 +467,48 @@ type channel struct {
 	inviteList    []string // exceptions from +I
 }
 
-func newChannel() *channel {
-	return &channel{userLimit: -1}
-}
+func (ch *channel) getMode(discloseSecrets bool) string {
+	var buf []byte
+	if 0 != ch.modes&ircChanModeInviteOnly {
+		buf = append(buf, 'i')
+	}
+	if 0 != ch.modes&ircChanModeModerated {
+		buf = append(buf, 'm')
+	}
+	if 0 != ch.modes&ircChanModeNoOutsideMsgs {
+		buf = append(buf, 'n')
+	}
+	if 0 != ch.modes&ircChanModeQuiet {
+		buf = append(buf, 'q')
+	}
+	if 0 != ch.modes&ircChanModePrivate {
+		buf = append(buf, 'p')
+	}
+	if 0 != ch.modes&ircChanModeSecret {
+		buf = append(buf, 's')
+	}
+	if 0 != ch.modes&ircChanModeProtectedTopic {
+		buf = append(buf, 'r')
+	}
 
-// TODO: Port struct channel methods.
+	if ch.userLimit != -1 {
+		buf = append(buf, 'l')
+	}
+	if ch.key != "" {
+		buf = append(buf, 'k')
+	}
+
+	// XXX: Is it correct to split it? Try it on an existing implementation.
+	if discloseSecrets {
+		if ch.userLimit != -1 {
+			buf = append(buf, fmt.Sprintf(" %d", ch.userLimit)...)
+		}
+		if ch.key != "" {
+			buf = append(buf, fmt.Sprintf(" %s", ch.key)...)
+		}
+	}
+	return string(buf)
+}
 
 // --- IRC server context ------------------------------------------------------
 
@@ -854,6 +911,7 @@ func (c *client) sendLUSERS() {
 	c.sendReply(RPL_LUSERME, nUsers+nServices+nUnknown, 0 /* peer servers */)
 }
 
+// TODO: Rename back to ircIsThisMe for consistency with kike.
 func isThisMe(target string) bool {
 	// Target servers can also be matched by their users
 	if ircFnmatch(target, serverName) {
@@ -1237,7 +1295,6 @@ func ircChannelMulticast(ch *channel, msg string, except *client) {
 	}
 }
 
-/*
 func ircModifyMode(mask *uint, mode uint, add bool) bool {
 	orig := *mask
 	if add {
@@ -1249,9 +1306,365 @@ func ircModifyMode(mask *uint, mode uint, add bool) bool {
 }
 
 func ircUpdateUserMode(c *client, newMode uint) {
-	// TODO: Port, as well as all the other kike functions.
+	oldMode := c.mode
+	c.mode = newMode
+
+	added, removed := newMode & ^oldMode, oldMode & ^newMode
+
+	var diff []byte
+	if added != 0 {
+		diff = append(diff, '+')
+		diff = ircAppendClientModes(added, diff)
+	}
+	if removed != 0 {
+		diff = append(diff, '-')
+		diff = ircAppendClientModes(removed, diff)
+	}
+
+	if len(diff) > 0 {
+		c.sendf(":%s MODE %s :%s", c.nickname, c.nickname, string(diff))
+	}
 }
-*/
+
+func ircHandleUserModeChange(c *client, modeString string) {
+	newMode := c.mode
+	adding := true
+
+	for _, flag := range modeString {
+		switch flag {
+		case '+':
+			adding = true
+		case '-':
+			adding = false
+
+		case 'a':
+			// Ignore, the client should use AWAY.
+		case 'i':
+			ircModifyMode(&newMode, ircUserModeInvisible, adding)
+		case 'w':
+			ircModifyMode(&newMode, ircUserModeRxWallops, adding)
+		case 'r':
+			// It's not possible ot un-restrict yourself.
+			if adding {
+				newMode |= ircUserModeRestricted
+			}
+		case 'o':
+			if !adding {
+				newMode &= ^ircUserModeOperator
+			} else if operators[c.tlsCertFingerprint] {
+				newMode |= ircUserModeOperator
+			} else {
+				c.sendf(":%s NOTICE %s :Either you're not using an TLS"+
+					" client certificate, or the fingerprint doesn't match",
+					serverName, c.nickname)
+			}
+		case 's':
+			ircModifyMode(&newMode, ircUserModeRxServerNotices, adding)
+		default:
+			c.sendReply(ERR_UMODEUNKNOWNFLAG)
+			return
+		}
+	}
+	ircUpdateUserMode(c, newMode)
+}
+
+func ircSendChannelList(c *client, channelName string, list []string,
+	reply, endReply int) {
+	for _, line := range list {
+		c.sendReply(reply, channelName, line)
+	}
+	c.sendReply(endReply, channelName)
+}
+
+func ircCheckExpandUserMask(mask string) string {
+	var result []byte
+	result = append(result, mask...)
+
+	// Make sure it is a complete mask.
+	if bytes.IndexByte(result, '!') < 0 {
+		result = append(result, "!*"...)
+	}
+	if bytes.IndexByte(result, '@') < 0 {
+		result = append(result, "@*"...)
+	}
+
+	// And validate whatever the result is.
+	s := string(result)
+	if !ircIsValidUserMask(s) {
+		return ""
+	}
+
+	return s
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+// Channel MODE command handling. This is by far the worst command to implement
+// from the whole RFC; don't blame me if it doesn't work exactly as expected.
+
+type modeProcessor struct {
+	params []string // mode string parameters
+
+	c       *client  // who does the changes
+	ch      *channel // the channel we're modifying
+	present bool     // c present on ch
+	modes   uint     // channel user modes
+
+	adding   bool // currently adding modes
+	modeChar byte // currently processed mode char
+
+	added   []byte  // added modes
+	removed []byte  // removed modes
+	output  *[]byte // "added" or "removed"
+
+	addedParams   []string  // params for added modes
+	removedParams []string  // params for removed modes
+	outputParams  *[]string // "addedParams" or "removedParams"
+}
+
+func (mp *modeProcessor) nextParam() string {
+	if len(mp.params) == 0 {
+		return ""
+	}
+
+	param := mp.params[0]
+	mp.params = mp.params[1:]
+	return param
+}
+
+func (mp *modeProcessor) checkOperator() bool {
+	if (mp.present && 0 != mp.modes&ircChanModeOperator) ||
+		0 != mp.c.mode&ircUserModeOperator {
+		return true
+	}
+
+	mp.c.sendReply(ERR_CHANOPRIVSNEEDED, mp.ch.name)
+	return false
+}
+
+func (mp *modeProcessor) doUser(mode uint) {
+	target := mp.nextParam()
+	if !mp.checkOperator() || target == "" {
+		return
+	}
+
+	if client := users[ircToCanon(target)]; client == nil {
+		mp.c.sendReply(ERR_NOSUCHNICK, target)
+	} else if modes, present := mp.ch.userModes[client]; !present {
+		mp.c.sendReply(ERR_USERNOTINCHANNEL, target, mp.ch.name)
+	} else if ircModifyMode(&modes, mode, mp.adding) {
+		mp.ch.userModes[client] = modes
+		*mp.output = append(*mp.output, mp.modeChar)
+		*mp.outputParams = append(*mp.outputParams, client.nickname)
+	}
+}
+
+func (mp *modeProcessor) doChan(mode uint) bool {
+	if !mp.checkOperator() || !ircModifyMode(&mp.ch.modes, mode, mp.adding) {
+		return false
+	}
+	*mp.output = append(*mp.output, mp.modeChar)
+	return true
+}
+
+func (mp *modeProcessor) doChanRemove(modeChar byte, mode uint) {
+	if mp.adding && ircModifyMode(&mp.ch.modes, mode, false) {
+		mp.removed = append(mp.removed, modeChar)
+	}
+}
+
+func (mp *modeProcessor) doList(list *[]string, listMsg, endMsg int) {
+	target := mp.nextParam()
+	if target == "" {
+		if mp.adding {
+			ircSendChannelList(mp.c, mp.ch.name, *list, listMsg, endMsg)
+		}
+		return
+	}
+
+	if !mp.checkOperator() {
+		return
+	}
+
+	mask := ircCheckExpandUserMask(target)
+	if mask == "" {
+		return
+	}
+
+	var i int
+	for i = 0; i < len(*list); i++ {
+		if ircEqual((*list)[i], mask) {
+			break
+		}
+	}
+
+	found := i < len(*list)
+	if found != mp.adding {
+		if mp.adding {
+			*list = append(*list, mask)
+		} else {
+			*list = append((*list)[:i], (*list)[i+1:]...)
+		}
+
+		*mp.output = append(*mp.output, mp.modeChar)
+		*mp.outputParams = append(*mp.outputParams, mask)
+	}
+}
+
+func (mp *modeProcessor) doKey() {
+	target := mp.nextParam()
+	if !mp.checkOperator() || target == "" {
+		return
+	}
+
+	if !mp.adding {
+		if mp.ch.key == "" || !ircEqual(target, mp.ch.key) {
+			return
+		}
+
+		mp.removed = append(mp.removed, mp.modeChar)
+		mp.removedParams = append(mp.removedParams, mp.ch.key)
+		mp.ch.key = ""
+	} else if !ircIsValidKey(target) {
+		// TODO: We should notify the user somehow.
+		return
+	} else if mp.ch.key != "" {
+		mp.c.sendReply(ERR_KEYSET, mp.ch.name)
+	} else {
+		mp.ch.key = target
+		mp.added = append(mp.added, mp.modeChar)
+		mp.addedParams = append(mp.addedParams, mp.ch.key)
+	}
+}
+
+func (mp *modeProcessor) doLimit() {
+	if !mp.checkOperator() {
+		return
+	}
+
+	if !mp.adding {
+		if mp.ch.userLimit == -1 {
+			return
+		}
+
+		mp.ch.userLimit = -1
+		mp.removed = append(mp.removed, mp.modeChar)
+	} else if target := mp.nextParam(); target != "" {
+		if x, err := strconv.ParseInt(target, 10, 32); err == nil && x > 0 {
+			mp.ch.userLimit = int(x)
+			mp.added = append(mp.added, mp.modeChar)
+			mp.addedParams = append(mp.addedParams, target)
+		}
+	}
+}
+
+func (mp *modeProcessor) step(modeChar byte) bool {
+	mp.modeChar = modeChar
+	switch mp.modeChar {
+	case '+':
+		mp.adding = true
+		mp.output = &mp.added
+		mp.outputParams = &mp.addedParams
+	case '-':
+		mp.adding = false
+		mp.output = &mp.removed
+		mp.outputParams = &mp.removedParams
+
+	case 'o':
+		mp.doUser(ircChanModeOperator)
+	case 'v':
+		mp.doUser(ircChanModeVoice)
+
+	case 'i':
+		mp.doChan(ircChanModeInviteOnly)
+	case 'm':
+		mp.doChan(ircChanModeModerated)
+	case 'n':
+		mp.doChan(ircChanModeNoOutsideMsgs)
+	case 'q':
+		mp.doChan(ircChanModeQuiet)
+	case 't':
+		mp.doChan(ircChanModeProtectedTopic)
+
+	case 'p':
+		if mp.doChan(ircChanModePrivate) {
+			mp.doChanRemove('s', ircChanModeSecret)
+		}
+	case 's':
+		if mp.doChan(ircChanModeSecret) {
+			mp.doChanRemove('p', ircChanModePrivate)
+		}
+
+	case 'b':
+		mp.doList(&mp.ch.banList, RPL_BANLIST, RPL_ENDOFBANLIST)
+	case 'e':
+		mp.doList(&mp.ch.banList, RPL_EXCEPTLIST, RPL_ENDOFEXCEPTLIST)
+	case 'I':
+		mp.doList(&mp.ch.banList, RPL_INVITELIST, RPL_ENDOFINVITELIST)
+
+	case 'k':
+		mp.doKey()
+	case 'l':
+		mp.doLimit()
+
+	default:
+		// It's not safe to continue, results could be undesired.
+		mp.c.sendReply(ERR_UNKNOWNMODE, modeChar, mp.ch.name)
+		return false
+	}
+	return true
+}
+
+func ircHandleChanModeChange(c *client, ch *channel, params []string) {
+	modes, present := ch.userModes[c]
+	mp := &modeProcessor{
+		c:       c,
+		ch:      ch,
+		present: present,
+		modes:   modes,
+		params:  params,
+	}
+
+Outer:
+	for {
+		modeString := mp.nextParam()
+		if modeString == "" {
+			break
+		}
+
+		mp.step('+')
+		for _, modeChar := range []byte(modeString) {
+			if !mp.step(modeChar) {
+				break Outer
+			}
+		}
+	}
+
+	// TODO: Limit to three changes with parameter per command.
+	if len(mp.added) > 0 || len(mp.removed) > 0 {
+		buf := []byte(fmt.Sprintf(":%s!%s@%s MODE %s ",
+			mp.c.nickname, mp.c.username, mp.c.hostname, mp.ch.name))
+		if len(mp.added) > 0 {
+			buf = append(buf, '+')
+			buf = append(buf, mp.added...)
+		}
+		if len(mp.removed) > 0 {
+			buf = append(buf, '-')
+			buf = append(buf, mp.removed...)
+		}
+		for _, param := range mp.addedParams {
+			buf = append(buf, ' ')
+			buf = append(buf, param...)
+		}
+		for _, param := range mp.removedParams {
+			buf = append(buf, ' ')
+			buf = append(buf, param...)
+		}
+		ircChannelMulticast(mp.ch, string(buf), nil)
+	}
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
 func ircHandleMODE(msg *message, c *client) {
 	if len(msg.params) < 1 {
@@ -1259,17 +1672,32 @@ func ircHandleMODE(msg *message, c *client) {
 		return
 	}
 
-	// TODO
 	target := msg.params[0]
 	client := users[ircToCanon(target)]
-	ch := users[ircToCanon(target)]
+	ch := channels[ircToCanon(target)]
 
 	if client != nil {
-		// TODO
 		if ircEqual(target, c.nickname) {
+			c.sendReply(ERR_USERSDONTMATCH)
+			return
+		}
+
+		if len(msg.params) < 2 {
+			c.sendReply(RPL_UMODEIS, c.getMode())
+		} else {
+			ircHandleUserModeChange(c, msg.params[1])
 		}
 	} else if ch != nil {
-		// TODO
+		if len(msg.params) < 2 {
+			_, present := ch.userModes[c]
+			c.sendReply(RPL_CHANNELMODEIS, target, ch.getMode(present))
+			c.sendReply(RPL_CREATIONTIME,
+				target, ch.created/int64(time.Second))
+		} else {
+			ircHandleChanModeChange(c, ch, msg.params[1:])
+		}
+	} else {
+		c.sendReply(ERR_NOSUCHNICK, target)
 	}
 }
 
@@ -1973,21 +2401,128 @@ func ircHandleADMIN(msg *message, c *client) {
 	c.sendReply(ERR_NOADMININFO, serverName)
 }
 
-// TODO: All the remaining command handlers.
+func ircHandleStatsLinks(c *client, msg *message) {
+	// There is only an "l" query in RFC 2812 but we cannot link,
+	// so instead we provide the "L" query giving information for all users.
+	filter := ""
+	if len(msg.params) > 1 {
+		filter = msg.params[1]
+	}
 
-func ircHandleX(msg *message, c *client) {
-	if len(msg.params) < 1 {
+	for _, client := range users {
+		if filter != "" && !ircEqual(client.nickname, filter) {
+			continue
+		}
+		c.sendReply(RPL_STATSLINKINFO,
+			client.address,    // linkname
+			len(client.sendQ), // sendq
+			client.nSentMessages, client.sentBytes/1024,
+			client.nReceivedMessages, client.receivedBytes/1024,
+			(time.Now().UnixNano()-client.opened)/int64(time.Second))
+	}
+}
+
+func ircHandleStatsCommands(c *client) {
+	for name, handler := range ircHandlers {
+		if handler.nReceived > 0 {
+			c.sendReply(RPL_STATSCOMMANDS, name,
+				handler.nReceived, handler.bytesReceived, 0)
+		}
+	}
+}
+
+// We need to do it this way because of an initialization loop concerning
+// ircHandlers. Workaround proposed by rsc in #1817.
+var ircHandleStatsCommandsIndirect func(c *client)
+
+func init() {
+	ircHandleStatsCommandsIndirect = ircHandleStatsCommands
+}
+
+func ircHandleStatsUptime(c *client) {
+	uptime := (time.Now().UnixNano() - started) / int64(time.Second)
+
+	days := uptime / 60 / 60 / 24
+	hours := (uptime % (60 * 60 * 24)) / 60 / 60
+	mins := (uptime % (60 * 60)) / 60
+	secs := uptime % 60
+
+	c.sendReply(RPL_STATSUPTIME, days, hours, mins, secs)
+}
+
+func ircHandleSTATS(msg *message, c *client) {
+	var query byte
+	if len(msg.params) > 0 && len(msg.params[0]) > 0 {
+		query = msg.params[0][0]
+	}
+
+	if len(msg.params) > 1 && !isThisMe(msg.params[1]) {
+		c.sendReply(ERR_NOSUCHSERVER, msg.params[0])
+		return
+	}
+	if 0 == c.mode&ircUserModeOperator {
+		c.sendReply(ERR_NOPRIVILEGES)
+		return
+	}
+
+	switch query {
+	case 'L':
+		ircHandleStatsLinks(c, msg)
+	case 'm':
+		ircHandleStatsCommandsIndirect(c)
+	case 'u':
+		ircHandleStatsUptime(c)
+	}
+	c.sendReply(RPL_ENDOFSTATS, query)
+}
+
+func ircHandleLINKS(msg *message, c *client) {
+	if len(msg.params) > 1 && !isThisMe(msg.params[0]) {
 		c.sendReply(ERR_NEEDMOREPARAMS, msg.command)
 		return
 	}
+
+	mask := "*"
+	if len(msg.params) > 0 {
+		if len(msg.params) > 1 {
+			mask = msg.params[1]
+		} else {
+			mask = msg.params[0]
+		}
+	}
+
+	if ircFnmatch(mask, serverName) {
+		c.sendReply(RPL_LINKS, mask, serverName,
+			0 /* hop count */, "TODO server_info from configuration")
+	}
+	c.sendReply(RPL_ENDOFLINKS, mask)
+}
+
+func ircHandleKILL(msg *message, c *client) {
+	if len(msg.params) < 2 {
+		c.sendReply(ERR_NEEDMOREPARAMS, msg.command)
+		return
+	}
+	if 0 == c.mode&ircUserModeOperator {
+		c.sendReply(ERR_NOPRIVILEGES)
+		return
+	}
+
+	target := users[ircToCanon(msg.params[0])]
+	if target == nil {
+		c.sendReply(ERR_NOSUCHNICK, msg.params[0])
+		return
+	}
+
+	c.sendf(":%s!%s@%s KILL %s :%s",
+		c.nickname, c.username, c.hostname, target.nickname, msg.params[1])
+	target.closeLink(fmt.Sprintf("Killed by %s: %s", c.nickname, msg.params[1]))
 }
 
 func ircHandleDIE(msg *message, c *client) {
 	if 0 == c.mode&ircUserModeOperator {
 		c.sendReply(ERR_NOPRIVILEGES)
-		return
-	}
-	if !quitting {
+	} else if !quitting {
 		initiateQuit()
 	}
 }
@@ -2015,6 +2550,8 @@ var ircHandlers = map[string]*ircCommand{
 	"SUMMON":   {true, ircHandleSUMMON, 0, 0},
 	"AWAY":     {true, ircHandleAWAY, 0, 0},
 	"ADMIN":    {true, ircHandleADMIN, 0, 0},
+	"STATS":    {true, ircHandleSTATS, 0, 0},
+	"LINKS":    {true, ircHandleLINKS, 0, 0},
 
 	"MODE":    {true, ircHandleMODE, 0, 0},
 	"PRIVMSG": {true, ircHandlePRIVMSG, 0, 0},
@@ -2031,7 +2568,8 @@ var ircHandlers = map[string]*ircCommand{
 	"WHOWAS":  {true, ircHandleWHOWAS, 0, 0},
 	"ISON":    {true, ircHandleISON, 0, 0},
 
-	"DIE": {true, ircHandleDIE, 0, 0},
+	"KILL": {true, ircHandleKILL, 0, 0},
+	"DIE":  {true, ircHandleDIE, 0, 0},
 }
 
 func ircProcessMessage(c *client, msg *message, raw string) {