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authorWillem de Bruijn <willemb@google.com>2015-01-30 21:29:31 +0300
committerDavid S. Miller <davem@davemloft.net>2015-02-03 05:46:51 +0300
commit49ca0d8bfaf3bc46d5eef60ce67b00eb195bd392 (patch)
treed2f55a32923f6d91fcb2e0d0e0b6d2d4eb6f9abd /net
parent9766e97af1b901ffbb36fcc648e50626d926bb24 (diff)
downloadlinux-49ca0d8bfaf3bc46d5eef60ce67b00eb195bd392.tar.xz
net-timestamp: no-payload option
Add timestamping option SOF_TIMESTAMPING_OPT_TSONLY. For transmit timestamps, this loops timestamps on top of empty packets. Doing so reduces the pressure on SO_RCVBUF. Payload inspection and cmsg reception (aside from timestamps) are no longer possible. This works together with a follow on patch that allows administrators to only allow tx timestamping if it does not loop payload or metadata. Signed-off-by: Willem de Bruijn <willemb@google.com> ---- Changes (rfc -> v1) - add documentation - remove unnecessary skb->len test (thanks to Richard Cochran) Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/skbuff.c19
-rw-r--r--net/ipv4/ip_sockglue.c7
-rw-r--r--net/ipv6/datagram.c5
-rw-r--r--net/rxrpc/ar-error.c5
4 files changed, 25 insertions, 11 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 56db472e9b86..65a3798f43e6 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3710,19 +3710,28 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
struct sock *sk, int tstype)
{
struct sk_buff *skb;
+ bool tsonly = sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TSONLY;
if (!sk)
return;
- if (hwtstamps)
- *skb_hwtstamps(orig_skb) = *hwtstamps;
+ if (tsonly)
+ skb = alloc_skb(0, GFP_ATOMIC);
else
- orig_skb->tstamp = ktime_get_real();
-
- skb = skb_clone(orig_skb, GFP_ATOMIC);
+ skb = skb_clone(orig_skb, GFP_ATOMIC);
if (!skb)
return;
+ if (tsonly) {
+ skb_shinfo(skb)->tx_flags = skb_shinfo(orig_skb)->tx_flags;
+ skb_shinfo(skb)->tskey = skb_shinfo(orig_skb)->tskey;
+ }
+
+ if (hwtstamps)
+ *skb_hwtstamps(skb) = *hwtstamps;
+ else
+ skb->tstamp = ktime_get_real();
+
__skb_complete_tx_timestamp(skb, sk, tstype);
}
EXPORT_SYMBOL_GPL(__skb_tstamp_tx);
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index db5e0f81ce0a..31d8c71986b4 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -483,7 +483,7 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
serr = SKB_EXT_ERR(skb);
- if (sin) {
+ if (sin && skb->len) {
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
serr->addr_offset);
@@ -496,8 +496,9 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
sin = &errhdr.offender;
memset(sin, 0, sizeof(*sin));
- if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
- ipv4_pktinfo_prepare_errqueue(sk, skb, serr->ee.ee_origin)) {
+ if (skb->len &&
+ (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
+ ipv4_pktinfo_prepare_errqueue(sk, skb, serr->ee.ee_origin))) {
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
if (inet_sk(sk)->cmsg_flags)
diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index 49f5e73db122..c215be70cac0 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -369,7 +369,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
serr = SKB_EXT_ERR(skb);
- if (sin) {
+ if (sin && skb->len) {
const unsigned char *nh = skb_network_header(skb);
sin->sin6_family = AF_INET6;
sin->sin6_flowinfo = 0;
@@ -394,8 +394,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
sin = &errhdr.offender;
memset(sin, 0, sizeof(*sin));
-
- if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
+ if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL && skb->len) {
sin->sin6_family = AF_INET6;
if (np->rxopt.all) {
if (serr->ee.ee_origin != SO_EE_ORIGIN_ICMP &&
diff --git a/net/rxrpc/ar-error.c b/net/rxrpc/ar-error.c
index 74c0fcd36838..5394b6be46ec 100644
--- a/net/rxrpc/ar-error.c
+++ b/net/rxrpc/ar-error.c
@@ -42,6 +42,11 @@ void rxrpc_UDP_error_report(struct sock *sk)
_leave("UDP socket errqueue empty");
return;
}
+ if (!skb->len) {
+ _leave("UDP empty message");
+ kfree_skb(skb);
+ return;
+ }
rxrpc_new_skb(skb);