X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Documentation%2Fnetworking%2Fcan.txt;h=5b04b67ddca2c3f2318cdd11c434a7cf9db981f3;hb=c0f62edd400115e54c52692c1dc6f5bf58ea0ba6;hp=cd79735013f94728c15359f292f5fad4b1d0f838;hpb=bbb20089a3275a19e475dbc21320c3742e3ca423;p=pandora-kernel.git

diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt
index cd79735013f9..5b04b67ddca2 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)
@@ -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)