summaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorMartin KaFai Lau <kafai@fb.com>2020-05-18 17:13:34 -0700
committerDavid S. Miller <davem@davemloft.net>2020-05-19 15:36:21 -0700
commit88d7fcfa3b1fe670f0412b95be785aafca63352b (patch)
tree77f8741e34fcce4cea09a3872781664b04c78557 /net
parentc27a204383616efba5a4194075e90819961ff66a (diff)
net: inet_csk: Fix so_reuseport bind-address cache in tb->fast*
The commit 637bc8bbe6c0 ("inet: reset tb->fastreuseport when adding a reuseport sk") added a bind-address cache in tb->fast*. The tb->fast* caches the address of a sk which has successfully been binded with SO_REUSEPORT ON. The idea is to avoid the expensive conflict search in inet_csk_bind_conflict(). There is an issue with wildcard matching where sk_reuseport_match() should have returned false but it is currently returning true. It ends up hiding bind conflict. For example, bind("[::1]:443"); /* without SO_REUSEPORT. Succeed. */ bind("[::2]:443"); /* with SO_REUSEPORT. Succeed. */ bind("[::]:443"); /* with SO_REUSEPORT. Still Succeed where it shouldn't */ The last bind("[::]:443") with SO_REUSEPORT on should have failed because it should have a conflict with the very first bind("[::1]:443") which has SO_REUSEPORT off. However, the address "[::2]" is cached in tb->fast* in the second bind. In the last bind, the sk_reuseport_match() returns true because the binding sk's wildcard addr "[::]" matches with the "[::2]" cached in tb->fast*. The correct bind conflict is reported by removing the second bind such that tb->fast* cache is not involved and forces the bind("[::]:443") to go through the inet_csk_bind_conflict(): bind("[::1]:443"); /* without SO_REUSEPORT. Succeed. */ bind("[::]:443"); /* with SO_REUSEPORT. -EADDRINUSE */ The expected behavior for sk_reuseport_match() is, it should only allow the "cached" tb->fast* address to be used as a wildcard match but not the address of the binding sk. To do that, the current "bool match_wildcard" arg is split into "bool match_sk1_wildcard" and "bool match_sk2_wildcard". This change only affects the sk_reuseport_match() which is only used by inet_csk (e.g. TCP). The other use cases are calling inet_rcv_saddr_equal() and this patch makes it pass the same "match_wildcard" arg twice to the "ipv[46]_rcv_saddr_equal(..., match_wildcard, match_wildcard)". Cc: Josef Bacik <jbacik@fb.com> Fixes: 637bc8bbe6c0 ("inet: reset tb->fastreuseport when adding a reuseport sk") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/inet_connection_sock.c43
1 files changed, 24 insertions, 19 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 5f34eb951627..65c29f2bd89f 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -24,17 +24,19 @@
#include <net/addrconf.h>
#if IS_ENABLED(CONFIG_IPV6)
-/* match_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
- * only, and any IPv4 addresses if not IPv6 only
- * match_wildcard == false: addresses must be exactly the same, i.e.
- * IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
- * and 0.0.0.0 equals to 0.0.0.0 only
+/* match_sk*_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses
+ * if IPv6 only, and any IPv4 addresses
+ * if not IPv6 only
+ * match_sk*_wildcard == false: addresses must be exactly the same, i.e.
+ * IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
+ * and 0.0.0.0 equals to 0.0.0.0 only
*/
static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
const struct in6_addr *sk2_rcv_saddr6,
__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
bool sk1_ipv6only, bool sk2_ipv6only,
- bool match_wildcard)
+ bool match_sk1_wildcard,
+ bool match_sk2_wildcard)
{
int addr_type = ipv6_addr_type(sk1_rcv_saddr6);
int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
@@ -44,8 +46,8 @@ static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
if (!sk2_ipv6only) {
if (sk1_rcv_saddr == sk2_rcv_saddr)
return true;
- if (!sk1_rcv_saddr || !sk2_rcv_saddr)
- return match_wildcard;
+ return (match_sk1_wildcard && !sk1_rcv_saddr) ||
+ (match_sk2_wildcard && !sk2_rcv_saddr);
}
return false;
}
@@ -53,11 +55,11 @@ static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
return true;
- if (addr_type2 == IPV6_ADDR_ANY && match_wildcard &&
+ if (addr_type2 == IPV6_ADDR_ANY && match_sk2_wildcard &&
!(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
return true;
- if (addr_type == IPV6_ADDR_ANY && match_wildcard &&
+ if (addr_type == IPV6_ADDR_ANY && match_sk1_wildcard &&
!(sk1_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
return true;
@@ -69,18 +71,19 @@ static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
}
#endif
-/* match_wildcard == true: 0.0.0.0 equals to any IPv4 addresses
- * match_wildcard == false: addresses must be exactly the same, i.e.
- * 0.0.0.0 only equals to 0.0.0.0
+/* match_sk*_wildcard == true: 0.0.0.0 equals to any IPv4 addresses
+ * match_sk*_wildcard == false: addresses must be exactly the same, i.e.
+ * 0.0.0.0 only equals to 0.0.0.0
*/
static bool ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
- bool sk2_ipv6only, bool match_wildcard)
+ bool sk2_ipv6only, bool match_sk1_wildcard,
+ bool match_sk2_wildcard)
{
if (!sk2_ipv6only) {
if (sk1_rcv_saddr == sk2_rcv_saddr)
return true;
- if (!sk1_rcv_saddr || !sk2_rcv_saddr)
- return match_wildcard;
+ return (match_sk1_wildcard && !sk1_rcv_saddr) ||
+ (match_sk2_wildcard && !sk2_rcv_saddr);
}
return false;
}
@@ -96,10 +99,12 @@ bool inet_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
sk2->sk_rcv_saddr,
ipv6_only_sock(sk),
ipv6_only_sock(sk2),
+ match_wildcard,
match_wildcard);
#endif
return ipv4_rcv_saddr_equal(sk->sk_rcv_saddr, sk2->sk_rcv_saddr,
- ipv6_only_sock(sk2), match_wildcard);
+ ipv6_only_sock(sk2), match_wildcard,
+ match_wildcard);
}
EXPORT_SYMBOL(inet_rcv_saddr_equal);
@@ -285,10 +290,10 @@ static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
tb->fast_rcv_saddr,
sk->sk_rcv_saddr,
tb->fast_ipv6_only,
- ipv6_only_sock(sk), true);
+ ipv6_only_sock(sk), true, false);
#endif
return ipv4_rcv_saddr_equal(tb->fast_rcv_saddr, sk->sk_rcv_saddr,
- ipv6_only_sock(sk), true);
+ ipv6_only_sock(sk), true, false);
}
/* Obtain a reference to a local port for the given sock,