d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

uipc_socket.c: Modify MSG_TLSAPPDATA to only do Alert Records

Browse Source 
Without this patch, the MSG_TLSAPPDATA flag would cause
soreceive_generic() to return ENXIO for any non-application
data record in a TLS receive stream.

This works ok for TLS1.2, since Alert records appear to be
the only non-application data records received.
However, for TLS1.3, there can be post-handshake handshake
records, such as NewSessionKey sent to the client from the
server. These handshake records cannot be handled by the
upcall which does an SSL_read() with length == 0.

It appears that the client can simply throw away these
NewSessionKey records, but to do so, it needs to receive
them within the kernel.

This patch modifies the semantics of MSG_TLSAPPDATA slightly,
so that it only applies to Alert records and not Handshake
records. It is needed to allow the krpc to work with KTLS1.3.

Reviewed by:	hselasky
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D35170
This commit is contained in:
Rick Macklem 2022-05-14 12:56:50 -07:00
parent 6543fa5a5c
commit 373511338d
3 changed files with 7 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
sys/kern/uipc_socket.c
View File

@ -2127,8 +2127,8 @@ dontblock:
struct tls_get_record tgr;
/*
* For MSG_TLSAPPDATA, check for a non-application data
* record. If found, return ENXIO without removing
* For MSG_TLSAPPDATA, check for an alert record.
* If found, return ENXIO without removing
* it from the receive queue. This allows a subsequent
* call without MSG_TLSAPPDATA to receive it.
* Note that, for TLS, there should only be a single
@ -2139,8 +2139,8 @@ dontblock:
if (cmsg->cmsg_type == TLS_GET_RECORD &&
cmsg->cmsg_len == CMSG_LEN(sizeof(tgr))) {
memcpy(&tgr, CMSG_DATA(cmsg), sizeof(tgr));
/* This will need to change for TLS 1.3. */
if (tgr.tls_type != TLS_RLTYPE_APP) {
if (__predict_false(tgr.tls_type ==
TLS_RLTYPE_ALERT)) {
SOCKBUF_UNLOCK(&so->so_rcv);
error = ENXIO;
goto release;

2
sys/sys/ktls.h
View File

@ -50,6 +50,8 @@ struct tls_record_layer {
#define TLS_CBC_IMPLICIT_IV_LEN 16
/* Type values for the record layer */
#define TLS_RLTYPE_ALERT 21
#define TLS_RLTYPE_HANDSHAKE 22
#define TLS_RLTYPE_APP 23
/*

2
sys/sys/socket.h
View File

@ -470,7 +470,7 @@ struct msghdr {
#endif
#ifdef _KERNEL
#define MSG_MORETOCOME 0x00100000 /* additional data pending */
#define MSG_TLSAPPDATA 0x00200000 /* only soreceive() app. data (TLS) */
#define MSG_TLSAPPDATA 0x00200000 /* do not soreceive() alert rec. (TLS) */
#endif
/*