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Merge pull request #915 from slingamn/issue817_fakelag.1

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fix #817
This commit is contained in:
Shivaram Lingamneni 2020-03-29 18:00:34 -07:00 committed by GitHub
commit bbd8807d65
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6 changed files with 118 additions and 42 deletions
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62
irc/client.go
View File

@ -112,9 +112,10 @@ type Session struct {
rawHostname string
isTor bool
idletimer IdleTimer
fakelag Fakelag
destroyed uint32
idletimer IdleTimer
fakelag Fakelag
deferredFakelagCount int
destroyed uint32
certfp string
sasl saslStatus
@ -148,6 +149,42 @@ type MultilineBatch struct {
tags map[string]string
}
// Starts a multiline batch, failing if there's one already open
func (s *Session) StartMultilineBatch(label, target, responseLabel string, tags map[string]string) (err error) {
if s.batch.label != "" {
return errInvalidMultilineBatch
}
s.batch.label, s.batch.target, s.batch.responseLabel, s.batch.tags = label, target, responseLabel, tags
s.fakelag.Suspend()
return
}
// Closes a multiline batch unconditionally; returns the batch and whether
// it was validly terminated (pass "" as the label if you don't care about the batch)
func (s *Session) EndMultilineBatch(label string) (batch MultilineBatch, err error) {
batch = s.batch
s.batch = MultilineBatch{}
s.fakelag.Unsuspend()
// heuristics to estimate how much data they used while fakelag was suspended
fakelagBill := (batch.message.LenBytes() / 512) + 1
fakelagBillLines := (batch.message.LenLines() * 60) / 512
if fakelagBill < fakelagBillLines {
fakelagBill = fakelagBillLines
}
s.deferredFakelagCount = fakelagBill
if batch.label == "" || batch.label != label || batch.message.LenLines() == 0 {
err = errInvalidMultilineBatch
return
}
batch.message.SetTime()
return
}
// sets the session quit message, if there isn't one already
func (sd *Session) SetQuitMessage(message string) (set bool) {
if message == "" {
@ -596,7 +633,11 @@ func (client *Client) run(session *Session, proxyLine string) {
}
if client.registered {
session.fakelag.Touch()
touches := session.deferredFakelagCount + 1
session.deferredFakelagCount = 0
for i := 0; i < touches; i++ {
session.fakelag.Touch()
}
} else {
// DoS hardening, #505
session.registrationMessages++
@ -617,19 +658,6 @@ func (client *Client) run(session *Session, proxyLine string) {
break
}
// "Clients MUST NOT send messages other than PRIVMSG while a multiline batch is open."
// in future we might want to whitelist some commands that are allowed here, like PONG
if session.batch.label != "" && msg.Command != "BATCH" {
_, batchTag := msg.GetTag("batch")
if batchTag != session.batch.label {
if msg.Command != "NOTICE" {
session.Send(nil, client.server.name, "FAIL", "BATCH", "MULTILINE_INVALID", client.t("Incorrect batch tag sent"))
}
session.batch = MultilineBatch{}
continue
}
}
cmd, exists := Commands[msg.Command]
if !exists {
if len(msg.Command) > 0 {

2
irc/commands.go
View File

@ -47,7 +47,7 @@ func (cmd *Command) Run(server *Server, client *Client, session *Session, msg ir
}
if session.batch.label != "" && !cmd.allowedInBatch {
rb.Add(nil, server.name, "FAIL", "BATCH", "MULTILINE_INVALID", client.t("Command not allowed during a multiline batch"))
session.batch = MultilineBatch{}
session.EndMultilineBatch("")
return false
}

1
irc/errors.go
View File

@ -60,6 +60,7 @@ var (
errCASFailed = errors.New("Compare-and-swap update of database value failed")
errEmptyCredentials = errors.New("No more credentials are approved")
errCredsExternallyManaged = errors.New("Credentials are externally managed and cannot be changed here")
errInvalidMultilineBatch = errors.New("Invalid multiline batch")
)
// Socket Errors

17
irc/fakelag.go
View File

@ -25,6 +25,7 @@ const (
// from the loop that accepts the client's input and runs commands
type Fakelag struct {
config FakelagConfig
suspended bool
nowFunc func() time.Time
sleepFunc func(time.Duration)
@ -40,6 +41,22 @@ func (fl *Fakelag) Initialize(config FakelagConfig) {
fl.state = FakelagBursting
}
// Idempotently turn off fakelag if it's enabled
func (fl *Fakelag) Suspend() {
if fl.config.Enabled {
fl.suspended = true
fl.config.Enabled = false
}
}
// Idempotently turn fakelag back on if it was previously Suspend'ed
func (fl *Fakelag) Unsuspend() {
if fl.suspended {
fl.config.Enabled = true
fl.suspended = false
}
}
// register a new command, sleep if necessary to delay it
func (fl *Fakelag) Touch() {
if !fl.config.Enabled {

32
irc/fakelag_test.go
View File

@ -121,3 +121,35 @@ func TestFakelag(t *testing.T) {
t.Fatalf("should not have slept")
}
}
func TestSuspend(t *testing.T) {
window, _ := time.ParseDuration("1s")
fl, _ := newFakelagForTesting(window, 3, 2, window)
assertEqual(fl.config.Enabled, true, t)
// suspend idempotently disables
fl.Suspend()
assertEqual(fl.config.Enabled, false, t)
fl.Suspend()
assertEqual(fl.config.Enabled, false, t)
// unsuspend idempotently enables
fl.Unsuspend()
assertEqual(fl.config.Enabled, true, t)
fl.Unsuspend()
assertEqual(fl.config.Enabled, true, t)
fl.Suspend()
assertEqual(fl.config.Enabled, false, t)
fl2, _ := newFakelagForTesting(window, 3, 2, window)
fl2.config.Enabled = false
// if we were never enabled, suspend and unsuspend are both no-ops
fl2.Suspend()
assertEqual(fl2.config.Enabled, false, t)
fl2.Suspend()
assertEqual(fl2.config.Enabled, false, t)
fl2.Unsuspend()
assertEqual(fl2.config.Enabled, false, t)
fl2.Unsuspend()
assertEqual(fl2.config.Enabled, false, t)
}

46
irc/handlers.go
View File

@ -332,30 +332,20 @@ func batchHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Res
if len(tag) == 0 {
fail = true
} else if tag[0] == '+' {
if rb.session.batch.label != "" || msg.Params[1] != caps.MultilineBatchType {
if len(msg.Params) < 3 || msg.Params[1] != caps.MultilineBatchType {
fail = true
} else {
rb.session.batch.label = tag[1:]
rb.session.batch.tags = msg.ClientOnlyTags()
if len(msg.Params) == 2 {
fail = true
} else {
rb.session.batch.target = msg.Params[2]
// save the response label for later
rb.session.batch.responseLabel = rb.Label
err := rb.session.StartMultilineBatch(tag[1:], msg.Params[2], rb.Label, msg.ClientOnlyTags())
fail = (err != nil)
if !fail {
// suppress ACK for the initial BATCH message (we'll apply the stored label later)
rb.Label = ""
}
}
} else if tag[0] == '-' {
if rb.session.batch.label == "" || rb.session.batch.label != tag[1:] {
fail = true
} else if rb.session.batch.message.LenLines() == 0 {
fail = true
} else {
batch := rb.session.batch
rb.session.batch = MultilineBatch{}
// time tag should correspond to the time when the message was completed
batch.message.SetTime()
batch, err := rb.session.EndMultilineBatch(tag[1:])
fail = (err != nil)
if !fail {
histType, err := msgCommandToHistType(batch.command)
if err != nil {
histType = history.Privmsg
@ -369,7 +359,7 @@ func batchHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Res
}
if fail {
rb.session.batch = MultilineBatch{}
rb.session.EndMultilineBatch("")
if sendErrors {
rb.Add(nil, server.name, "FAIL", "BATCH", "MULTILINE_INVALID", client.t("Invalid multiline batch"))
}
@ -1813,9 +1803,17 @@ func nickHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Resp
// helper to store a batched PRIVMSG in the session object
func absorbBatchedMessage(server *Server, client *Client, msg ircmsg.IrcMessage, batchTag string, histType history.ItemType, rb *ResponseBuffer) {
// sanity checks. batch tag correctness was already checked and is redundant here
// as a defensive measure. TAGMSG is checked without an error message: "don't eat paste"
if batchTag != rb.session.batch.label || histType == history.Tagmsg || len(msg.Params) == 1 || msg.Params[1] == "" {
if batchTag != rb.session.batch.label {
if histType != history.Notice {
rb.Add(nil, server.name, "FAIL", "BATCH", "MULTILINE_INVALID", client.t("Incorrect batch tag sent"))
}
rb.session.EndMultilineBatch("")
return
} else if len(msg.Params) < 2 || msg.Params[1] == "" {
if histType != history.Notice {
rb.Add(nil, server.name, "FAIL", "BATCH", "MULTILINE_INVALID", client.t("Invalid multiline batch"))
}
rb.session.EndMultilineBatch("")
return
}
rb.session.batch.command = msg.Command
@ -1826,12 +1824,12 @@ func absorbBatchedMessage(server *Server, client *Client, msg ircmsg.IrcMessage,
if histType != history.Notice {
rb.Add(nil, server.name, "FAIL", "BATCH", "MULTILINE_MAX_BYTES", strconv.Itoa(config.Limits.Multiline.MaxBytes))
}
rb.session.batch = MultilineBatch{}
rb.session.EndMultilineBatch("")
} else if config.Limits.Multiline.MaxLines != 0 && config.Limits.Multiline.MaxLines < rb.session.batch.message.LenLines() {
if histType != history.Notice {
rb.Add(nil, server.name, "FAIL", "BATCH", "MULTILINE_MAX_LINES", strconv.Itoa(config.Limits.Multiline.MaxLines))
}
rb.session.batch = MultilineBatch{}
rb.session.EndMultilineBatch("")
}
}