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ergo/irc/uban.go
2021-01-22 10:49:54 -05:00

417 lines
14 KiB
Go

// Copyright (c) 2021 Shivaram Lingamneni
// released under the MIT license
package irc
import (
"fmt"
"regexp"
"strings"
"time"
"github.com/goshuirc/irc-go/ircmsg"
"github.com/oragono/oragono/irc/custime"
"github.com/oragono/oragono/irc/flatip"
"github.com/oragono/oragono/irc/utils"
)
func consumeDuration(params []string, rb *ResponseBuffer) (duration time.Duration, requireSASL bool, remainingParams []string, err error) {
remainingParams = params
for {
if duration == 0 && 2 <= len(remainingParams) && strings.ToLower(remainingParams[0]) == "duration" {
duration, err = custime.ParseDuration(remainingParams[1])
if err != nil {
rb.Notice(rb.session.client.t("Invalid time duration for NS SUSPEND"))
return
}
remainingParams = remainingParams[2:]
continue
}
if !requireSASL && 1 <= len(remainingParams) && strings.ToLower(remainingParams[0]) == "require-sasl" {
requireSASL = true
remainingParams = remainingParams[1:]
continue
}
break
}
return
}
// a UBAN target is one of these syntactically unambiguous entities:
// an IP, a CIDR, a NUH mask, or an account name
type ubanType uint
const (
ubanCIDR ubanType = iota
ubanNickmask
ubanNick
)
// tagged union, i guess
type ubanTarget struct {
banType ubanType
cidr flatip.IPNet
matcher *regexp.Regexp
nickOrMask string
}
func parseUbanTarget(param string) (target ubanTarget, err error) {
if utils.SafeErrorParam(param) == "*" {
err = errInvalidParams
return
}
ipnet, ipErr := flatip.ParseToNormalizedNet(param)
if ipErr == nil {
target.banType = ubanCIDR
target.cidr = ipnet
return
}
if strings.IndexByte(param, '!') != -1 || strings.IndexByte(param, '@') != -1 {
canonicalized, cErr := CanonicalizeMaskWildcard(param)
if cErr != nil {
err = errInvalidParams
return
}
re, reErr := utils.CompileGlob(canonicalized, false)
if reErr != nil {
err = errInvalidParams
return
}
target.banType = ubanNickmask
target.nickOrMask = canonicalized
target.matcher = re
return
}
if _, cErr := CasefoldName(param); cErr == nil {
target.banType = ubanNick
target.nickOrMask = param
return
}
err = errInvalidParams
return
}
// UBAN <subcommand> [target] [DURATION <duration>] [reason...]
func ubanHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *ResponseBuffer) bool {
subcommand := strings.ToLower(msg.Params[0])
params := msg.Params[1:]
var target ubanTarget
if subcommand != "list" {
if len(msg.Params) == 1 {
rb.Add(nil, client.server.name, "FAIL", "UBAN", "INVALID_PARAMS", client.t("Not enough parameters"))
return false
}
var parseErr error
target, parseErr = parseUbanTarget(params[0])
if parseErr != nil {
rb.Add(nil, client.server.name, "FAIL", "UBAN", "INVALID_PARAMS", client.t("Couldn't parse ban target"))
return false
}
params = params[1:]
}
switch subcommand {
case "add":
return ubanAddHandler(client, target, params, rb)
case "del", "remove", "rm":
return ubanDelHandler(client, target, params, rb)
case "list":
return ubanListHandler(client, params, rb)
case "info":
return ubanInfoHandler(client, target, params, rb)
default:
rb.Add(nil, server.name, "FAIL", "UBAN", "UNKNOWN_COMMAND", client.t("Unknown command"))
return false
}
}
func sessionsForCIDR(server *Server, cidr flatip.IPNet, exclude *Session, requireSASL bool) (sessions []*Session, nicks []string) {
for _, client := range server.clients.AllClients() {
if requireSASL && client.Account() != "" {
continue
}
for _, session := range client.Sessions() {
seen := false
if session != exclude && cidr.Contains(flatip.FromNetIP(session.IP())) {
sessions = append(sessions, session)
if !seen {
seen = true
nicks = append(nicks, session.client.Nick())
}
}
}
}
return
}
func ubanAddHandler(client *Client, target ubanTarget, params []string, rb *ResponseBuffer) bool {
duration, requireSASL, params, err := consumeDuration(params, rb)
if err != nil {
return false
}
operReason := strings.Join(params, " ")
switch target.banType {
case ubanCIDR:
ubanAddCIDR(client, target, duration, requireSASL, operReason, rb)
case ubanNickmask:
ubanAddNickmask(client, target, duration, operReason, rb)
case ubanNick:
ubanAddAccount(client, target, duration, operReason, rb)
}
return false
}
func ubanAddCIDR(client *Client, target ubanTarget, duration time.Duration, requireSASL bool, operReason string, rb *ResponseBuffer) {
err := client.server.dlines.AddNetwork(target.cidr, duration, requireSASL, "", operReason, client.Oper().Name)
if err == nil {
rb.Notice(fmt.Sprintf(client.t("Successfully added UBAN for %s"), target.cidr.HumanReadableString()))
} else {
client.server.logger.Error("internal", "ubanAddCIDR failed", err.Error())
rb.Notice(client.t("An error occurred"))
return
}
sessions, nicks := sessionsForCIDR(client.server, target.cidr, rb.session, requireSASL)
for _, session := range sessions {
session.client.Quit("You have been banned from this server", session)
session.client.destroy(session)
}
if len(sessions) != 0 {
rb.Notice(fmt.Sprintf(client.t("Killed %[1]d active client(s) from %[2]s, associated with %[3]d nickname(s):"), len(sessions), target.cidr.String(), len(nicks)))
for _, line := range utils.BuildTokenLines(400, nicks, " ") {
rb.Notice(line)
}
}
}
func ubanAddNickmask(client *Client, target ubanTarget, duration time.Duration, operReason string, rb *ResponseBuffer) {
err := client.server.klines.AddMask(target.nickOrMask, duration, "", operReason, client.Oper().Name)
if err == nil {
rb.Notice(fmt.Sprintf(client.t("Successfully added UBAN for %s"), target.nickOrMask))
} else {
client.server.logger.Error("internal", "ubanAddNickmask failed", err.Error())
rb.Notice(client.t("An error occurred"))
return
}
var killed []string
var alwaysOn []string
for _, mcl := range client.server.clients.AllClients() {
if mcl != client && target.matcher.MatchString(client.NickMaskCasefolded()) {
if !mcl.AlwaysOn() {
killed = append(killed, mcl.Nick())
mcl.destroy(nil)
} else {
alwaysOn = append(alwaysOn, mcl.Nick())
}
}
}
if len(killed) != 0 {
rb.Notice(fmt.Sprintf(client.t("Killed %d clients:"), len(killed)))
for _, line := range utils.BuildTokenLines(400, killed, " ") {
rb.Notice(line)
}
}
if len(alwaysOn) != 0 {
rb.Notice(fmt.Sprintf(client.t("Warning: %d clients matched this rule, but were not killed due to being always-on:"), len(alwaysOn)))
for _, line := range utils.BuildTokenLines(400, alwaysOn, " ") {
rb.Notice(line)
}
rb.Notice(client.t("You can suspend their accounts instead; try /UBAN ADD <nickname>"))
}
}
func ubanAddAccount(client *Client, target ubanTarget, duration time.Duration, operReason string, rb *ResponseBuffer) {
account := target.nickOrMask
// TODO this doesn't enumerate all sessions if ForceNickEqualsAccount is disabled
var sessionData []SessionData
if mcl := client.server.clients.Get(account); mcl != nil {
sessionData, _ = mcl.AllSessionData(nil, true)
}
err := client.server.accounts.Suspend(account, duration, client.Oper().Name, operReason)
switch err {
case nil:
rb.Notice(fmt.Sprintf(client.t("Successfully suspended account %s"), account))
if len(sessionData) != 0 {
rb.Notice(fmt.Sprintf(client.t("Disconnected %d client(s) associated with the account, using the following IPs:"), len(sessionData)))
for i, d := range sessionData {
rb.Notice(fmt.Sprintf("%d. %s", i+1, d.ip.String()))
}
}
case errAccountDoesNotExist:
rb.Notice(client.t("No such account"))
default:
rb.Notice(client.t("An error occurred"))
}
}
func ubanDelHandler(client *Client, target ubanTarget, params []string, rb *ResponseBuffer) bool {
var err error
var targetString string
switch target.banType {
case ubanCIDR:
if target.cidr.PrefixLen == 128 {
client.server.connectionLimiter.ResetThrottle(target.cidr.IP)
rb.Notice(fmt.Sprintf(client.t("Reset throttle for IP: %s"), target.cidr.IP.String()))
}
targetString = target.cidr.HumanReadableString()
err = client.server.dlines.RemoveNetwork(target.cidr)
case ubanNickmask:
targetString = target.nickOrMask
err = client.server.klines.RemoveMask(target.nickOrMask)
case ubanNick:
targetString = target.nickOrMask
err = client.server.accounts.Unsuspend(target.nickOrMask)
}
if err == nil {
rb.Notice(fmt.Sprintf(client.t("Successfully removed ban on %s"), targetString))
} else {
rb.Notice(fmt.Sprintf(client.t("Could not remove ban: %v"), err))
}
return false
}
func ubanListHandler(client *Client, params []string, rb *ResponseBuffer) bool {
allDlines := client.server.dlines.AllBans()
rb.Notice(fmt.Sprintf(client.t("There are %d active IP/network ban(s) (DLINEs)"), len(allDlines)))
for key, info := range allDlines {
rb.Notice(formatBanForListing(client, key, info))
}
rb.Notice(client.t("Some IPs may also be prevented from connecting by the connection limiter and/or throttler"))
allKlines := client.server.klines.AllBans()
rb.Notice(fmt.Sprintf(client.t("There are %d active ban(s) on nick-user-host masks (KLINEs)"), len(allKlines)))
for key, info := range allKlines {
rb.Notice(formatBanForListing(client, key, info))
}
listAccountSuspensions(client, rb, client.server.name)
return false
}
func ubanInfoHandler(client *Client, target ubanTarget, params []string, rb *ResponseBuffer) bool {
switch target.banType {
case ubanCIDR:
ubanInfoCIDR(client, target, rb)
case ubanNickmask:
ubanInfoNickmask(client, target, rb)
case ubanNick:
ubanInfoNick(client, target, rb)
}
return false
}
func ubanInfoCIDR(client *Client, target ubanTarget, rb *ResponseBuffer) {
if target.cidr.PrefixLen == 128 {
netName, status := client.server.connectionLimiter.Status(target.cidr.IP)
if status.Exempt {
rb.Notice(fmt.Sprintf(client.t("IP %s is exempt from connection limits"), target.cidr.IP.String()))
} else {
rb.Notice(fmt.Sprintf(client.t("Network %[1]s has %[2]d active connections out of a maximum of %[3]d"), netName, status.Count, status.MaxCount))
rb.Notice(fmt.Sprintf(client.t("Network %[1]s has had %[2]d connection attempts in the past %[3]v, out of a maximum of %[4]d"), netName, status.Throttle, status.ThrottleDuration, status.MaxPerWindow))
}
}
str := target.cidr.HumanReadableString()
isBanned, banInfo := client.server.dlines.CheckIP(target.cidr.IP)
if isBanned {
rb.Notice(formatBanForListing(client, str, banInfo))
} else {
rb.Notice(fmt.Sprintf(client.t("There is no active IP ban against %s"), str))
}
sessions, nicks := sessionsForCIDR(client.server, target.cidr, nil, false)
if len(sessions) != 0 {
rb.Notice(fmt.Sprintf(client.t("There are %[1]d active client(s) from %[2]s, associated with %[3]d nickname(s):"), len(sessions), target.cidr.String(), len(nicks)))
for _, line := range utils.BuildTokenLines(400, nicks, " ") {
rb.Notice(line)
}
}
}
func ubanInfoNickmask(client *Client, target ubanTarget, rb *ResponseBuffer) {
isBanned, info := client.server.klines.ContainsMask(target.nickOrMask)
if isBanned {
rb.Notice(formatBanForListing(client, target.nickOrMask, info))
} else {
rb.Notice(fmt.Sprintf(client.t("No ban exists for %[1]s"), target.nickOrMask))
}
affectedCount := 0
alwaysOnCount := 0
for _, mcl := range client.server.clients.AllClients() {
matches := false
for _, mask := range mcl.AllNickmasks() {
if target.matcher.MatchString(mask) {
matches = true
break
}
}
if matches {
if mcl.AlwaysOn() {
alwaysOnCount++
} else {
affectedCount++
}
}
}
rb.Notice(fmt.Sprintf(client.t("Adding this mask would affect %[1]d clients (an additional %[2]d clients are exempt due to always-on)"), affectedCount, alwaysOnCount))
}
func ubanInfoNick(client *Client, target ubanTarget, rb *ResponseBuffer) {
mcl := client.server.clients.Get(target.nickOrMask)
if mcl != nil {
details := mcl.Details()
sessions := mcl.Sessions()
ip := mcl.IP()
sendIPBanWarning := false
if details.account == "" {
rb.Notice(fmt.Sprintf(client.t("Client %[1]s is unauthenticated and connected from %[2]s"), details.nick, ip.String()))
sendIPBanWarning = true
} else {
rb.Notice(fmt.Sprintf(client.t("Client %[1]s is logged into account %[2]s and has %[3]d active clients (see /NICKSERV CLIENTS LIST %[4]s for more info"), details.nick, details.accountName, len(mcl.Sessions()), details.nick))
if !ip.IsLoopback() && len(sessions) == 1 {
rb.Notice(fmt.Sprintf(client.t("Client %[1]s is associated with IP %[2]s"), details.nick, ip.String()))
sendIPBanWarning = true
}
}
if sendIPBanWarning {
rb.Notice(client.t("Warning: banning this IP or a network that contains it may affect other users. Use /UBAN INFO on the candidate IP or network for more information."))
}
} else {
rb.Notice(fmt.Sprintf(client.t("No client is currently using that nickname")))
}
account, err := client.server.accounts.LoadAccount(target.nickOrMask)
if err != nil {
if err == errAccountDoesNotExist {
rb.Notice(fmt.Sprintf(client.t("There is no account registered for %s"), target.nickOrMask))
} else {
rb.Notice(fmt.Sprintf(client.t("Couldn't load account: %v"), err.Error()))
}
return
}
if account.Verified {
if account.Suspended == nil {
rb.Notice(fmt.Sprintf(client.t("Account %[1]s is in good standing; see /NICKSERV INFO %[2]s for more details"), target.nickOrMask, target.nickOrMask))
} else {
rb.Notice(fmt.Sprintf(client.t("Account %[1]s has been suspended: %[2]s"), target.nickOrMask, suspensionToString(client, *account.Suspended)))
}
} else {
rb.Notice(fmt.Sprintf(client.t("Account %[1]s was created, but has not been verified"), target.nickOrMask))
}
}