From a9d361b4be7d6329bedd7b37d454c1abf4f27233 Mon Sep 17 00:00:00 2001 From: Lukas Larsson Date: Thu, 21 Jun 2018 11:00:25 +0200 Subject: erts: Limit the automatic max buffer for UDP to 2^16 There is no reason to have a larger buffer than this as the recvmsg call will never return more data. OTP-15206 --- erts/emulator/drivers/common/inet_drv.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'erts/emulator/drivers') diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c index 833befefd1..2048d0f625 100644 --- a/erts/emulator/drivers/common/inet_drv.c +++ b/erts/emulator/drivers/common/inet_drv.c @@ -1549,6 +1549,8 @@ static void *realloc_wrapper(void *current, ErlDrvSizeT size){ # define LOAD_ASSOC_ID LOAD_UINT # define LOAD_ASSOC_ID_CNT LOAD_UINT_CNT # define SCTP_ANC_BUFF_SIZE INET_DEF_BUFFER/2 /* XXX: not very good... */ +#else +# define IS_SCTP(desc) 0 #endif #ifdef HAVE_UDP @@ -6436,7 +6438,12 @@ static int inet_set_opts(inet_descriptor* desc, char* ptr, int len) (long)desc->port, desc->s, res)); if (type == SO_RCVBUF) { /* make sure we have desc->bufsz >= SO_RCVBUF */ - if (ival > desc->bufsz) + if (ival > (1 << 16) && desc->stype == SOCK_DGRAM && !IS_SCTP(desc)) + /* For UDP we don't want to automatically + set the buffer size to be larger than + the theoretical max MTU */ + desc->bufsz = 1 << 16; + else if (ival > desc->bufsz) desc->bufsz = ival; } } -- cgit v1.2.3