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authorWillem de Bruijn <willemb@google.com>2014-12-01 03:22:34 (GMT)
committerDavid S. Miller <davem@davemloft.net>2014-12-09 01:20:48 (GMT)
commit829ae9d611651467fe6cd7be834bd33ca6b28dfe (patch)
treec61fa3c4fcf20e77540eb8090cde1cec49120e7e /net/ipv6
parent7ce875e5ecb8562fd44040f69bda96c999e38bbc (diff)
downloadlinux-829ae9d611651467fe6cd7be834bd33ca6b28dfe.tar.xz
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>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/datagram.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index cc11396..2464a00 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -325,6 +325,16 @@ void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
kfree_skb(skb);
}
+static void ip6_datagram_prepare_pktinfo_errqueue(struct sk_buff *skb)
+{
+ int ifindex = skb->dev ? skb->dev->ifindex : -1;
+
+ if (skb->protocol == htons(ETH_P_IPV6))
+ IP6CB(skb)->iif = ifindex;
+ else
+ PKTINFO_SKB_CB(skb)->ipi_ifindex = ifindex;
+}
+
/*
* Handle MSG_ERRQUEUE
*/
@@ -388,8 +398,12 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
sin->sin6_family = AF_INET6;
sin->sin6_flowinfo = 0;
sin->sin6_port = 0;
- if (np->rxopt.all)
+ if (np->rxopt.all) {
+ if (serr->ee.ee_origin != SO_EE_ORIGIN_ICMP &&
+ serr->ee.ee_origin != SO_EE_ORIGIN_ICMP6)
+ ip6_datagram_prepare_pktinfo_errqueue(skb);
ip6_datagram_recv_common_ctl(sk, msg, skb);
+ }
if (skb->protocol == htons(ETH_P_IPV6)) {
sin->sin6_addr = ipv6_hdr(skb)->saddr;
if (np->rxopt.all)
@@ -491,7 +505,10 @@ void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
&src_info.ipi6_addr);
}
- put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
+
+ if (src_info.ipi6_ifindex >= 0)
+ put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
+ sizeof(src_info), &src_info);
}
}