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Message-Id: <1451927367-14527-1-git-send-email-dsa@cumulusnetworks.com>
Date: Mon, 4 Jan 2016 09:09:27 -0800
From: David Ahern <dsa@...ulusnetworks.com>
To: netdev@...r.kernel.org
Cc: David Ahern <dsa@...ulusnetworks.com>
Subject: [PATCH net] net: Propagate lookup failure in l3mdev_get_saddr to caller
Commands run in a vrf context are not failing as expected on a route lookup:
root@...ny:~# ip ro ls table vrf-red
unreachable default
root@...ny:~# ping -I vrf-red -c1 -w1 10.100.1.254
ping: Warning: source address might be selected on device other than vrf-red.
PING 10.100.1.254 (10.100.1.254) from 0.0.0.0 vrf-red: 56(84) bytes of data.
--- 10.100.1.254 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 999ms
Since the vrf table does not have a route for 10.100.1.254 the ping
should have failed. The saddr lookup causes a full VRF table lookup.
Propogating a lookup failure to the user allows the command to fail as
expected:
root@...ny:~# ping -I vrf-red -c1 -w1 10.100.1.254
connect: No route to host
Signed-off-by: David Ahern <dsa@...ulusnetworks.com>
---
DaveM: This is needed for 4.4; no backport to 4.3 is needed.
drivers/net/vrf.c | 10 +++++++---
include/net/l3mdev.h | 16 ++++++++++------
include/net/route.h | 7 ++++++-
net/ipv4/raw.c | 7 +++++--
net/ipv4/udp.c | 7 +++++--
5 files changed, 33 insertions(+), 14 deletions(-)
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 56abdf224d35..66addb7a7911 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -742,7 +742,7 @@ static struct rtable *vrf_get_rtable(const struct net_device *dev,
}
/* called under rcu_read_lock */
-static void vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
+static int vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
{
struct fib_result res = { .tclassid = 0 };
struct net *net = dev_net(dev);
@@ -750,9 +750,10 @@ static void vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
u8 flags = fl4->flowi4_flags;
u8 scope = fl4->flowi4_scope;
u8 tos = RT_FL_TOS(fl4);
+ int rc;
if (unlikely(!fl4->daddr))
- return;
+ return 0;
fl4->flowi4_flags |= FLOWI_FLAG_SKIP_NH_OIF;
fl4->flowi4_iif = LOOPBACK_IFINDEX;
@@ -760,7 +761,8 @@ static void vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
- if (!fib_lookup(net, fl4, &res, 0)) {
+ rc = fib_lookup(net, fl4, &res, 0);
+ if (!rc) {
if (res.type == RTN_LOCAL)
fl4->saddr = res.fi->fib_prefsrc ? : fl4->daddr;
else
@@ -770,6 +772,8 @@ static void vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
fl4->flowi4_flags = flags;
fl4->flowi4_tos = orig_tos;
fl4->flowi4_scope = scope;
+
+ return rc;
}
#if IS_ENABLED(CONFIG_IPV6)
diff --git a/include/net/l3mdev.h b/include/net/l3mdev.h
index 786226f8e77b..5567d46b3cff 100644
--- a/include/net/l3mdev.h
+++ b/include/net/l3mdev.h
@@ -29,7 +29,7 @@ struct l3mdev_ops {
/* IPv4 ops */
struct rtable * (*l3mdev_get_rtable)(const struct net_device *dev,
const struct flowi4 *fl4);
- void (*l3mdev_get_saddr)(struct net_device *dev,
+ int (*l3mdev_get_saddr)(struct net_device *dev,
struct flowi4 *fl4);
/* IPv6 ops */
@@ -130,10 +130,11 @@ static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
return rc;
}
-static inline void l3mdev_get_saddr(struct net *net, int ifindex,
- struct flowi4 *fl4)
+static inline int l3mdev_get_saddr(struct net *net, int ifindex,
+ struct flowi4 *fl4)
{
struct net_device *dev;
+ int rc = 0;
if (ifindex) {
@@ -142,11 +143,13 @@ static inline void l3mdev_get_saddr(struct net *net, int ifindex,
dev = dev_get_by_index_rcu(net, ifindex);
if (dev && netif_is_l3_master(dev) &&
dev->l3mdev_ops->l3mdev_get_saddr) {
- dev->l3mdev_ops->l3mdev_get_saddr(dev, fl4);
+ rc = dev->l3mdev_ops->l3mdev_get_saddr(dev, fl4);
}
rcu_read_unlock();
}
+
+ return rc;
}
static inline struct dst_entry *l3mdev_get_rt6_dst(const struct net_device *dev,
@@ -223,9 +226,10 @@ static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
return false;
}
-static inline void l3mdev_get_saddr(struct net *net, int ifindex,
- struct flowi4 *fl4)
+static inline int l3mdev_get_saddr(struct net *net, int ifindex,
+ struct flowi4 *fl4)
{
+ return 0;
}
static inline
diff --git a/include/net/route.h b/include/net/route.h
index ee81307863d5..a3b9ef74a389 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -283,7 +283,12 @@ static inline struct rtable *ip_route_connect(struct flowi4 *fl4,
sport, dport, sk);
if (!src && oif) {
- l3mdev_get_saddr(net, oif, fl4);
+ int rc;
+
+ rc = l3mdev_get_saddr(net, oif, fl4);
+ if (rc < 0)
+ return ERR_PTR(rc);
+
src = fl4->saddr;
}
if (!dst || !src) {
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 63e5be0abd86..bc35f1842512 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -601,8 +601,11 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
(inet->hdrincl ? FLOWI_FLAG_KNOWN_NH : 0),
daddr, saddr, 0, 0);
- if (!saddr && ipc.oif)
- l3mdev_get_saddr(net, ipc.oif, &fl4);
+ if (!saddr && ipc.oif) {
+ err = l3mdev_get_saddr(net, ipc.oif, &fl4);
+ if (err < 0)
+ goto done;
+ }
if (!inet->hdrincl) {
rfv.msg = msg;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 8841e984f8bf..93eec90fb880 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1026,8 +1026,11 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
flow_flags,
faddr, saddr, dport, inet->inet_sport);
- if (!saddr && ipc.oif)
- l3mdev_get_saddr(net, ipc.oif, fl4);
+ if (!saddr && ipc.oif) {
+ err = l3mdev_get_saddr(net, ipc.oif, fl4);
+ if (err < 0)
+ goto out;
+ }
security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
rt = ip_route_output_flow(net, fl4, sk);
--
1.9.1
--
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