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-rw-r--r--net/ipv4/af_inet.c1
-rw-r--r--net/ipv4/udp.c202
2 files changed, 185 insertions, 18 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index cfeb85cff4f0..35913fb77dc8 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1546,6 +1546,7 @@ static const struct net_protocol tcp_protocol = {
};
static const struct net_protocol udp_protocol = {
+ .early_demux = udp_v4_early_demux,
.handler = udp_rcv,
.err_handler = udp_err,
.no_policy = 1,
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 5950e12bd3ab..262ea3929da6 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -103,6 +103,7 @@
#include <linux/seq_file.h>
#include <net/net_namespace.h>
#include <net/icmp.h>
+#include <net/inet_hashtables.h>
#include <net/route.h>
#include <net/checksum.h>
#include <net/xfrm.h>
@@ -565,6 +566,26 @@ struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
}
EXPORT_SYMBOL_GPL(udp4_lib_lookup);
+static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
+ __be16 loc_port, __be32 loc_addr,
+ __be16 rmt_port, __be32 rmt_addr,
+ int dif, unsigned short hnum)
+{
+ struct inet_sock *inet = inet_sk(sk);
+
+ if (!net_eq(sock_net(sk), net) ||
+ udp_sk(sk)->udp_port_hash != hnum ||
+ (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
+ (inet->inet_dport != rmt_port && inet->inet_dport) ||
+ (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
+ ipv6_only_sock(sk) ||
+ (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
+ return false;
+ if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif))
+ return false;
+ return true;
+}
+
static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
__be16 loc_port, __be32 loc_addr,
__be16 rmt_port, __be32 rmt_addr,
@@ -575,20 +596,11 @@ static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
unsigned short hnum = ntohs(loc_port);
sk_nulls_for_each_from(s, node) {
- struct inet_sock *inet = inet_sk(s);
-
- if (!net_eq(sock_net(s), net) ||
- udp_sk(s)->udp_port_hash != hnum ||
- (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
- (inet->inet_dport != rmt_port && inet->inet_dport) ||
- (inet->inet_rcv_saddr &&
- inet->inet_rcv_saddr != loc_addr) ||
- ipv6_only_sock(s) ||
- (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
- continue;
- if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
- continue;
- goto found;
+ if (__udp_is_mcast_sock(net, s,
+ loc_port, loc_addr,
+ rmt_port, rmt_addr,
+ dif, hnum))
+ goto found;
}
s = NULL;
found:
@@ -1581,6 +1593,14 @@ static void flush_stack(struct sock **stack, unsigned int count,
kfree_skb(skb1);
}
+static void udp_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+
+ dst_hold(dst);
+ sk->sk_rx_dst = dst;
+}
+
/*
* Multicasts and broadcasts go to each listener.
*
@@ -1709,11 +1729,28 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
if (udp4_csum_init(skb, uh, proto))
goto csum_error;
- if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
- return __udp4_lib_mcast_deliver(net, skb, uh,
- saddr, daddr, udptable);
+ if (skb->sk) {
+ int ret;
+ sk = skb->sk;
- sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
+ if (unlikely(sk->sk_rx_dst == NULL))
+ udp_sk_rx_dst_set(sk, skb);
+
+ ret = udp_queue_rcv_skb(sk, skb);
+
+ /* a return value > 0 means to resubmit the input, but
+ * it wants the return to be -protocol, or 0
+ */
+ if (ret > 0)
+ return -ret;
+ return 0;
+ } else {
+ if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
+ return __udp4_lib_mcast_deliver(net, skb, uh,
+ saddr, daddr, udptable);
+
+ sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
+ }
if (sk != NULL) {
int ret;
@@ -1771,6 +1808,135 @@ drop:
return 0;
}
+/* We can only early demux multicast if there is a single matching socket.
+ * If more than one socket found returns NULL
+ */
+static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
+ __be16 loc_port, __be32 loc_addr,
+ __be16 rmt_port, __be32 rmt_addr,
+ int dif)
+{
+ struct sock *sk, *result;
+ struct hlist_nulls_node *node;
+ unsigned short hnum = ntohs(loc_port);
+ unsigned int count, slot = udp_hashfn(net, hnum, udp_table.mask);
+ struct udp_hslot *hslot = &udp_table.hash[slot];
+
+ rcu_read_lock();
+begin:
+ count = 0;
+ result = NULL;
+ sk_nulls_for_each_rcu(sk, node, &hslot->head) {
+ if (__udp_is_mcast_sock(net, sk,
+ loc_port, loc_addr,
+ rmt_port, rmt_addr,
+ dif, hnum)) {
+ result = sk;
+ ++count;
+ }
+ }
+ /*
+ * if the nulls value we got at the end of this lookup is
+ * not the expected one, we must restart lookup.
+ * We probably met an item that was moved to another chain.
+ */
+ if (get_nulls_value(node) != slot)
+ goto begin;
+
+ if (result) {
+ if (count != 1 ||
+ unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
+ result = NULL;
+ else if (unlikely(!__udp_is_mcast_sock(net, sk,
+ loc_port, loc_addr,
+ rmt_port, rmt_addr,
+ dif, hnum))) {
+ sock_put(result);
+ result = NULL;
+ }
+ }
+ rcu_read_unlock();
+ return result;
+}
+
+/* For unicast we should only early demux connected sockets or we can
+ * break forwarding setups. The chains here can be long so only check
+ * if the first socket is an exact match and if not move on.
+ */
+static struct sock *__udp4_lib_demux_lookup(struct net *net,
+ __be16 loc_port, __be32 loc_addr,
+ __be16 rmt_port, __be32 rmt_addr,
+ int dif)
+{
+ struct sock *sk, *result;
+ struct hlist_nulls_node *node;
+ unsigned short hnum = ntohs(loc_port);
+ unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum);
+ unsigned int slot2 = hash2 & udp_table.mask;
+ struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
+ INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr)
+ const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
+
+ rcu_read_lock();
+ result = NULL;
+ udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
+ if (INET_MATCH(sk, net, acookie,
+ rmt_addr, loc_addr, ports, dif))
+ result = sk;
+ /* Only check first socket in chain */
+ break;
+ }
+
+ if (result) {
+ if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
+ result = NULL;
+ else if (unlikely(!INET_MATCH(sk, net, acookie,
+ rmt_addr, loc_addr,
+ ports, dif))) {
+ sock_put(result);
+ result = NULL;
+ }
+ }
+ rcu_read_unlock();
+ return result;
+}
+
+void udp_v4_early_demux(struct sk_buff *skb)
+{
+ const struct iphdr *iph = ip_hdr(skb);
+ const struct udphdr *uh = udp_hdr(skb);
+ struct sock *sk;
+ struct dst_entry *dst;
+ struct net *net = dev_net(skb->dev);
+ int dif = skb->dev->ifindex;
+
+ /* validate the packet */
+ if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
+ return;
+
+ if (skb->pkt_type == PACKET_BROADCAST ||
+ skb->pkt_type == PACKET_MULTICAST)
+ sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
+ uh->source, iph->saddr, dif);
+ else if (skb->pkt_type == PACKET_HOST)
+ sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
+ uh->source, iph->saddr, dif);
+ else
+ return;
+
+ if (!sk)
+ return;
+
+ skb->sk = sk;
+ skb->destructor = sock_edemux;
+ dst = sk->sk_rx_dst;
+
+ if (dst)
+ dst = dst_check(dst, 0);
+ if (dst)
+ skb_dst_set_noref(skb, dst);
+}
+
int udp_rcv(struct sk_buff *skb)
{
return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 12:25:55 +0000