path: root/doc/src
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authorKirill Kinduk <[email protected]>2017-08-25 12:08:26 +0300
committerLoïc Hoguin <[email protected]>2018-03-28 16:58:02 +0200
commit4c34774b7eb787e37892399f2daddba68ec277e3 (patch)
tree8640e0950bb363acde6f87f1f7a2977d3185c852 /doc/src
parent288deb5b88dd8e0aae57c9858d16c19ca9f186f9 (diff)
Add max_frame_size option for websocket handlers
Option allows to limit a frame by size before decoding its payload. LH: I have added a test for when the limit is reached on a nofin fragmented frame (the last commit addressed that case but it had no test). I have fixed formatting and other, and changed the default value to infinity since it might otherwise be incompatible with existing code. I also added documentation and a bunch of other minor changes.
Diffstat (limited to 'doc/src')
2 files changed, 24 insertions, 0 deletions
diff --git a/doc/src/guide/ws_handlers.asciidoc b/doc/src/guide/ws_handlers.asciidoc
index c944606..71165af 100644
--- a/doc/src/guide/ws_handlers.asciidoc
+++ b/doc/src/guide/ws_handlers.asciidoc
@@ -225,6 +225,22 @@ init(Req, State) ->
This value cannot be changed once it is set. It defaults to
+=== Limiting frame sizes
+Cowboy accepts frames of any size by default. You should
+limit the size depending on what your handler may handle.
+You can do this via the `init/2` callback:
+init(Req, State) ->
+ {cowboy_websocket, Req, State, #{
+ max_frame_size => 8000000}}.
+The lack of limit is historical. A future version of
+Cowboy will have a more reasonable default.
=== Saving memory
The Websocket connection process can be set to hibernate
diff --git a/doc/src/manual/cowboy_websocket.asciidoc b/doc/src/manual/cowboy_websocket.asciidoc
index 40864c5..5d686b1 100644
--- a/doc/src/manual/cowboy_websocket.asciidoc
+++ b/doc/src/manual/cowboy_websocket.asciidoc
@@ -153,6 +153,7 @@ Cowboy does it automatically for you.
opts() :: #{
compress => boolean(),
idle_timeout => timeout(),
+ max_frame_size => non_neg_integer() | infinity,
req_filter => fun((cowboy_req:req()) -> map())
@@ -181,6 +182,13 @@ idle_timeout (60000)::
connection open without receiving anything from
the client.
+max_frame_size (infinity)::
+ Maximum frame size allowed by this Websocket
+ handler. Cowboy will close the connection when
+ a client attempts to send a frame that goes over
+ this limit. For fragmented frames this applies
+ to the size of the reconstituted frame.
A function applied to the Req to compact it and
only keep required information. The Req is only