[PATCH net] net: Propagate lookup failure in l3mdev_get_saddr to caller
From: David Ahern <hidden>
Date: 2016-01-04 17:09:34
Commands run in a vrf context are not failing as expected on a route lookup:
root@kenny:~# ip ro ls table vrf-red
unreachable default
root@kenny:~# 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@kenny:~# ping -I vrf-red -c1 -w1 10.100.1.254
connect: No route to host
Signed-off-by: David Ahern <redacted>
---
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