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Diffstat (limited to 'Documentation/networking/timestamping.rst')
| -rw-r--r-- | Documentation/networking/timestamping.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/networking/timestamping.rst b/Documentation/networking/timestamping.rst index 8199e6917671..b37bfbfc7d79 100644 --- a/Documentation/networking/timestamping.rst +++ b/Documentation/networking/timestamping.rst @@ -194,6 +194,20 @@ SOF_TIMESTAMPING_OPT_ID: among all possibly concurrently outstanding timestamp requests for that socket. + The process can optionally override the default generated ID, by + passing a specific ID with control message SCM_TS_OPT_ID (not + supported for TCP sockets):: + + struct msghdr *msg; + ... + cmsg = CMSG_FIRSTHDR(msg); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_TS_OPT_ID; + cmsg->cmsg_len = CMSG_LEN(sizeof(__u32)); + *((__u32 *) CMSG_DATA(cmsg)) = opt_id; + err = sendmsg(fd, msg, 0); + + SOF_TIMESTAMPING_OPT_ID_TCP: Pass this modifier along with SOF_TIMESTAMPING_OPT_ID for new TCP timestamping applications. SOF_TIMESTAMPING_OPT_ID defines how the |