64577de · typeable/wai

git.iko.soy/typeable/wai

preventing priority DOS attacks.

commit64577de65c34da4fff2da3db372775ad8d2ea8e9 authorKazu Yamamoto <kazu@iij.ad.jp> dateMon 16 Nov 2015, 12:29 (11 years ago) parent2d3106c

2 files changed+7−2

unifiedsplit

warp/Network/Wai/Handler/Warp/HTTP2/Receiver.hs+5−2

@@ -316,14 +316,17 @@ stream FrameRSTStream header bs _ _ strm = do

316316 closed strm cc

317317 return $ Closed cc -- will be written to streamState again

318318

319−stream FramePriority header bs Context{outputQ} s Stream{streamNumber,streamPrecedence} = do

319+stream FramePriority header bs Context{outputQ,priorityTreeSize} s Stream{streamNumber,streamPrecedence} = do

320320 PriorityFrame newpri <- guardIt $ decodePriorityFrame header bs

321321 checkPriority newpri streamNumber

322322 -- checkme: this should be tested

323323 oldpre <- readIORef streamPrecedence

324324 let !newpre = toPrecedence newpri

325325 writeIORef streamPrecedence newpre

326− if isIdle s then

326+ if isIdle s then do

327+ n <- atomicModifyIORef' priorityTreeSize (\x -> (x+1,x+1))

328+ -- fixme hard coding

329+ when (n >= 20) $ E.throwIO $ ConnectionError EnhanceYourCalm "too many idle priority frames"

327330 prepare outputQ streamNumber newpri

328331 else do

329332 mx <- delete outputQ streamNumber oldpre

warp/Network/Wai/Handler/Warp/HTTP2/Types.hs+2

@@ -130,6 +130,7 @@ data Context = Context {

130130 -- | Number of active streams initiated by the server; for respecting the

131131 -- client's max concurrency setting.

132132 , pushConcurrency :: IORef Int

133+ , priorityTreeSize :: IORef Int

133134 -- | RFC 7540 says "Other frames (from any stream) MUST NOT

134135 -- occur between the HEADERS frame and any CONTINUATION

135136 -- frames that might follow". This field is used to implement

@@ -153,6 +154,7 @@ newContext = Context <$> newIORef defaultSettings

153154 <*> initialize 10 -- fixme: hard coding: 10

154155 <*> newIORef 0

155156 <*> newIORef 0

157+ <*> newIORef 0

156158 <*> newIORef Nothing

157159 <*> newIORef 0

158160 <*> newIORef 2 -- first server push stream; 0 is reserved