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-rw-r--r--include/net/protocol.h4
-rw-r--r--include/net/route.h4
-rw-r--r--include/net/tcp.h2
-rw-r--r--include/net/udp.h2
-rw-r--r--net/ipv4/ip_input.c25
-rw-r--r--net/ipv4/route.c46
-rw-r--r--net/ipv4/tcp_ipv4.c9
-rw-r--r--net/ipv4/udp.c24
8 files changed, 71 insertions, 45 deletions
diff --git a/include/net/protocol.h b/include/net/protocol.h
index 65ba335b0e7e..4fc75f7ae23b 100644
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -39,8 +39,8 @@
/* This is used to register protocols. */
struct net_protocol {
- void (*early_demux)(struct sk_buff *skb);
- void (*early_demux_handler)(struct sk_buff *skb);
+ int (*early_demux)(struct sk_buff *skb);
+ int (*early_demux_handler)(struct sk_buff *skb);
int (*handler)(struct sk_buff *skb);
void (*err_handler)(struct sk_buff *skb, u32 info);
unsigned int no_policy:1,
diff --git a/include/net/route.h b/include/net/route.h
index 57dfc6850d37..d538e6db1afe 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -175,7 +175,9 @@ static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4
fl4->fl4_gre_key = gre_key;
return ip_route_output_key(net, fl4);
}
-
+int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+ u8 tos, struct net_device *dev,
+ struct in_device *in_dev, u32 *itag);
int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
u8 tos, struct net_device *devin);
int ip_route_input_rcu(struct sk_buff *skb, __be32 dst, __be32 src,
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 3bc910a9bfc6..89974c5286d8 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -345,7 +345,7 @@ void tcp_v4_err(struct sk_buff *skb, u32);
void tcp_shutdown(struct sock *sk, int how);
-void tcp_v4_early_demux(struct sk_buff *skb);
+int tcp_v4_early_demux(struct sk_buff *skb);
int tcp_v4_rcv(struct sk_buff *skb);
int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
diff --git a/include/net/udp.h b/include/net/udp.h
index 12dfbfe2e2d7..6c759c8594e2 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -259,7 +259,7 @@ static inline struct sk_buff *skb_recv_udp(struct sock *sk, unsigned int flags,
return __skb_recv_udp(sk, flags, noblock, &peeked, &off, err);
}
-void udp_v4_early_demux(struct sk_buff *skb);
+int udp_v4_early_demux(struct sk_buff *skb);
bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst);
int udp_get_port(struct sock *sk, unsigned short snum,
int (*saddr_cmp)(const struct sock *,
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index fa2dc8f692c6..57fc13c6ab2b 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -311,9 +311,10 @@ drop:
static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
const struct iphdr *iph = ip_hdr(skb);
- struct rtable *rt;
+ int (*edemux)(struct sk_buff *skb);
struct net_device *dev = skb->dev;
- void (*edemux)(struct sk_buff *skb);
+ struct rtable *rt;
+ int err;
/* if ingress device is enslaved to an L3 master device pass the
* skb to its handler for processing
@@ -331,7 +332,9 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
ipprot = rcu_dereference(inet_protos[protocol]);
if (ipprot && (edemux = READ_ONCE(ipprot->early_demux))) {
- edemux(skb);
+ err = edemux(skb);
+ if (unlikely(err))
+ goto drop_error;
/* must reload iph, skb->head might have changed */
iph = ip_hdr(skb);
}
@@ -342,13 +345,10 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
* how the packet travels inside Linux networking.
*/
if (!skb_valid_dst(skb)) {
- int err = ip_route_input_noref(skb, iph->daddr, iph->saddr,
- iph->tos, dev);
- if (unlikely(err)) {
- if (err == -EXDEV)
- __NET_INC_STATS(net, LINUX_MIB_IPRPFILTER);
- goto drop;
- }
+ err = ip_route_input_noref(skb, iph->daddr, iph->saddr,
+ iph->tos, dev);
+ if (unlikely(err))
+ goto drop_error;
}
#ifdef CONFIG_IP_ROUTE_CLASSID
@@ -399,6 +399,11 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
drop:
kfree_skb(skb);
return NET_RX_DROP;
+
+drop_error:
+ if (err == -EXDEV)
+ __NET_INC_STATS(net, LINUX_MIB_IPRPFILTER);
+ goto drop;
}
/*
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 94d4cd2d5ea4..ac6fde5d45f1 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1520,43 +1520,56 @@ struct rtable *rt_dst_alloc(struct net_device *dev,
EXPORT_SYMBOL(rt_dst_alloc);
/* called in rcu_read_lock() section */
-static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
- u8 tos, struct net_device *dev, int our)
+int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+ u8 tos, struct net_device *dev,
+ struct in_device *in_dev, u32 *itag)
{
- struct rtable *rth;
- struct in_device *in_dev = __in_dev_get_rcu(dev);
- unsigned int flags = RTCF_MULTICAST;
- u32 itag = 0;
int err;
/* Primary sanity checks. */
-
if (!in_dev)
return -EINVAL;
if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
skb->protocol != htons(ETH_P_IP))
- goto e_inval;
+ return -EINVAL;
if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
- goto e_inval;
+ return -EINVAL;
if (ipv4_is_zeronet(saddr)) {
if (!ipv4_is_local_multicast(daddr))
- goto e_inval;
+ return -EINVAL;
} else {
err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
- in_dev, &itag);
+ in_dev, itag);
if (err < 0)
- goto e_err;
+ return err;
}
+ return 0;
+}
+
+/* called in rcu_read_lock() section */
+static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+ u8 tos, struct net_device *dev, int our)
+{
+ struct in_device *in_dev = __in_dev_get_rcu(dev);
+ unsigned int flags = RTCF_MULTICAST;
+ struct rtable *rth;
+ u32 itag = 0;
+ int err;
+
+ err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
+ if (err)
+ return err;
+
if (our)
flags |= RTCF_LOCAL;
rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
if (!rth)
- goto e_nobufs;
+ return -ENOBUFS;
#ifdef CONFIG_IP_ROUTE_CLASSID
rth->dst.tclassid = itag;
@@ -1572,13 +1585,6 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
skb_dst_set(skb, &rth->dst);
return 0;
-
-e_nobufs:
- return -ENOBUFS;
-e_inval:
- return -EINVAL;
-e_err:
- return err;
}
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index d9416b5162bc..85164d4d3e53 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1503,23 +1503,23 @@ csum_err:
}
EXPORT_SYMBOL(tcp_v4_do_rcv);
-void tcp_v4_early_demux(struct sk_buff *skb)
+int tcp_v4_early_demux(struct sk_buff *skb)
{
const struct iphdr *iph;
const struct tcphdr *th;
struct sock *sk;
if (skb->pkt_type != PACKET_HOST)
- return;
+ return 0;
if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
- return;
+ return 0;
iph = ip_hdr(skb);
th = tcp_hdr(skb);
if (th->doff < sizeof(struct tcphdr) / 4)
- return;
+ return 0;
sk = __inet_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
iph->saddr, th->source,
@@ -1538,6 +1538,7 @@ void tcp_v4_early_demux(struct sk_buff *skb)
skb_dst_set_noref(skb, dst);
}
}
+ return 0;
}
bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ef29df8648e4..5676237d2b0f 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2221,9 +2221,10 @@ static struct sock *__udp4_lib_demux_lookup(struct net *net,
return NULL;
}
-void udp_v4_early_demux(struct sk_buff *skb)
+int udp_v4_early_demux(struct sk_buff *skb)
{
struct net *net = dev_net(skb->dev);
+ struct in_device *in_dev = NULL;
const struct iphdr *iph;
const struct udphdr *uh;
struct sock *sk = NULL;
@@ -2234,24 +2235,24 @@ void udp_v4_early_demux(struct sk_buff *skb)
/* validate the packet */
if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
- return;
+ return 0;
iph = ip_hdr(skb);
uh = udp_hdr(skb);
if (skb->pkt_type == PACKET_BROADCAST ||
skb->pkt_type == PACKET_MULTICAST) {
- struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
+ in_dev = __in_dev_get_rcu(skb->dev);
if (!in_dev)
- return;
+ return 0;
/* we are supposed to accept bcast packets */
if (skb->pkt_type == PACKET_MULTICAST) {
ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
iph->protocol);
if (!ours)
- return;
+ return 0;
}
sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
@@ -2263,7 +2264,7 @@ void udp_v4_early_demux(struct sk_buff *skb)
}
if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
- return;
+ return 0;
skb->sk = sk;
skb->destructor = sock_efree;
@@ -2272,12 +2273,23 @@ void udp_v4_early_demux(struct sk_buff *skb)
if (dst)
dst = dst_check(dst, 0);
if (dst) {
+ u32 itag = 0;
+
/* set noref for now.
* any place which wants to hold dst has to call
* dst_hold_safe()
*/
skb_dst_set_noref(skb, dst);
+
+ /* for unconnected multicast sockets we need to validate
+ * the source on each packet
+ */
+ if (!inet_sk(sk)->inet_daddr && in_dev)
+ return ip_mc_validate_source(skb, iph->daddr,
+ iph->saddr, iph->tos,
+ skb->dev, in_dev, &itag);
}
+ return 0;
}
int udp_rcv(struct sk_buff *skb)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.