linux_dsm_epyc7002/include/uapi
Willem de Bruijn 829ae9d611 net-timestamp: allow reading recv cmsg on errqueue with origin tstamp
Allow reading of timestamps and cmsg at the same time on all relevant
socket families. One use is to correlate timestamps with egress
device, by asking for cmsg IP_PKTINFO.

on AF_INET sockets, call the relevant function (ip_cmsg_recv). To
avoid changing legacy expectations, only do so if the caller sets a
new timestamping flag SOF_TIMESTAMPING_OPT_CMSG.

on AF_INET6 sockets, IPV6_PKTINFO and all other recv cmsg are already
returned for all origins. only change is to set ifindex, which is
not initialized for all error origins.

In both cases, only generate the pktinfo message if an ifindex is
known. This is not the case for ACK timestamps.

The difference between the protocol families is probably a historical
accident as a result of the different conditions for generating cmsg
in the relevant ip(v6)_recv_error function:

ipv4:        if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
ipv6:        if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {

At one time, this was the same test bar for the ICMP/ICMP6
distinction. This is no longer true.

Signed-off-by: Willem de Bruijn <willemb@google.com>

----

Changes
  v1 -> v2
    large rewrite
    - integrate with existing pktinfo cmsg generation code
    - on ipv4: only send with new flag, to maintain legacy behavior
    - on ipv6: send at most a single pktinfo cmsg
    - on ipv6: initialize fields if not yet initialized

The recv cmsg interfaces are also relevant to the discussion of
whether looping packet headers is problematic. For v6, cmsgs that
identify many headers are already returned. This patch expands
that to v4. If it sounds reasonable, I will follow with patches

1. request timestamps without payload with SOF_TIMESTAMPING_OPT_TSONLY
   (http://patchwork.ozlabs.org/patch/366967/)
2. sysctl to conditionally drop all timestamps that have payload or
   cmsg from users without CAP_NET_RAW.
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-08 20:20:48 -05:00
..
asm-generic net: sock: allow eBPF programs to be attached to sockets 2014-12-05 21:47:32 -08:00
drm drm/exynos: use drm generic mmap interface 2014-09-20 01:00:13 +09:00
linux net-timestamp: allow reading recv cmsg on errqueue with origin tstamp 2014-12-08 20:20:48 -05:00
misc cxl: Add documentation for userspace APIs 2014-10-08 20:16:19 +11:00
mtd mtd: lpddr: add driver for LPDDR2-NVM PCM memories 2014-05-20 17:45:17 -07:00
rdma Merge branches 'core', 'cxgb4', 'ipoib', 'iser', 'iwcm', 'mad', 'misc', 'mlx4', 'mlx5', 'ocrdma' and 'srp' into for-next 2014-08-14 08:58:04 -07:00
scsi
sound ALSA: pcm: Add big-endian DSD sample formats and fix XMOS DSD sample format 2014-11-21 15:13:28 +01:00
video
xen
Kbuild cxl: Add userspace header file 2014-10-08 20:15:57 +11:00