1 files changed, 13 insertions, 1 deletions

diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt
index cd79735013f9..56ca3b75376e 100644
--- a/Documentation/networking/can.txt
+++ b/Documentation/networking/can.txt
@@ -22,6 +22,7 @@ This file contains
       4.1.2 RAW socket option CAN_RAW_ERR_FILTER
       4.1.3 RAW socket option CAN_RAW_LOOPBACK
       4.1.4 RAW socket option CAN_RAW_RECV_OWN_MSGS
+      4.1.5 RAW socket returned message flags
     4.2 Broadcast Manager protocol sockets (SOCK_DGRAM)
     4.3 connected transport protocols (SOCK_SEQPACKET)
     4.4 unconnected transport protocols (SOCK_DGRAM)
@@ -239,7 +240,7 @@ solution for a couple of reasons:
   the user application using the common CAN filter mechanisms. Inside
   this filter definition the (interested) type of errors may be
   selected. The reception of error frames is disabled by default.
-  The format of the CAN error frame is briefly decribed in the Linux
+  The format of the CAN error frame is briefly described in the Linux
   header file "include/linux/can/error.h".
 
 4. How to use Socket CAN
@@ -471,6 +472,17 @@ solution for a couple of reasons:
     setsockopt(s, SOL_CAN_RAW, CAN_RAW_RECV_OWN_MSGS,
                &recv_own_msgs, sizeof(recv_own_msgs));
 
+  4.1.5 RAW socket returned message flags
+
+  When using recvmsg() call, the msg->msg_flags may contain following flags:
+
+    MSG_DONTROUTE: set when the received frame was created on the local host.
+
+    MSG_CONFIRM: set when the frame was sent via the socket it is received on.
+      This flag can be interpreted as a 'transmission confirmation' when the
+      CAN driver supports the echo of frames on driver level, see 3.2 and 6.2.
+      In order to receive such messages, CAN_RAW_RECV_OWN_MSGS must be set.
+
   4.2 Broadcast Manager protocol sockets (SOCK_DGRAM)
   4.3 connected transport protocols (SOCK_SEQPACKET)
   4.4 unconnected transport protocols (SOCK_DGRAM)