[PATCH bpf-next v3 4/7] net: remove duplicate reuseport_lookup functions
From: Lorenz Bauer
Date: Mon Jun 26 2023 - 11:09:40 EST
There are currently four copies of reuseport_lookup: one each for
(TCP, UDP)x(IPv4, IPv6). This forces us to duplicate all callers of
those functions as well. This is already the case for sk_lookup
helpers (inet,inet6,udp4,udp6)_lookup_run_bpf.
There are two differences between the reuseport_lookup helpers:
1. They call different hash functions depending on protocol
2. UDP reuseport_lookup checks that sk_state != TCP_ESTABLISHED
Move the check for sk_state into the caller and use the INDIRECT_CALL
infrastructure to cut down the helpers to one per IP version.
Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxx>
---
include/net/inet6_hashtables.h | 11 ++++++++++-
include/net/inet_hashtables.h | 15 ++++++++++-----
include/net/udp.h | 8 ++++++++
net/ipv4/inet_hashtables.c | 23 ++++++++++++++++-------
net/ipv4/udp.c | 34 +++++++++++++---------------------
net/ipv6/inet6_hashtables.c | 17 +++++++++++++----
net/ipv6/udp.c | 41 ++++++++++++++++-------------------------
7 files changed, 86 insertions(+), 63 deletions(-)
diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h
index 032ddab48f8f..49d586454287 100644
--- a/include/net/inet6_hashtables.h
+++ b/include/net/inet6_hashtables.h
@@ -48,12 +48,21 @@ struct sock *__inet6_lookup_established(struct net *net,
const u16 hnum, const int dif,
const int sdif);
+typedef u32 (*inet6_ehashfn_t)(const struct net *net,
+ const struct in6_addr *laddr, const u16 lport,
+ const struct in6_addr *faddr, const __be16 fport);
+
+u32 inet6_ehashfn(const struct net *net,
+ const struct in6_addr *laddr, const u16 lport,
+ const struct in6_addr *faddr, const __be16 fport);
+
struct sock *inet6_lookup_reuseport(struct net *net, struct sock *sk,
struct sk_buff *skb, int doff,
const struct in6_addr *saddr,
__be16 sport,
const struct in6_addr *daddr,
- unsigned short hnum);
+ unsigned short hnum,
+ inet6_ehashfn_t ehashfn);
struct sock *inet6_lookup_listener(struct net *net,
struct inet_hashinfo *hashinfo,
diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 8734f3488f5d..51ab6a1a3601 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -379,10 +379,19 @@ struct sock *__inet_lookup_established(struct net *net,
const __be32 daddr, const u16 hnum,
const int dif, const int sdif);
+typedef u32 (*inet_ehashfn_t)(const struct net *net,
+ const __be32 laddr, const __u16 lport,
+ const __be32 faddr, const __be16 fport);
+
+u32 inet_ehashfn(const struct net *net,
+ const __be32 laddr, const __u16 lport,
+ const __be32 faddr, const __be16 fport);
+
struct sock *inet_lookup_reuseport(struct net *net, struct sock *sk,
struct sk_buff *skb, int doff,
__be32 saddr, __be16 sport,
- __be32 daddr, unsigned short hnum);
+ __be32 daddr, unsigned short hnum,
+ inet_ehashfn_t ehashfn);
static inline struct sock *
inet_lookup_established(struct net *net, struct inet_hashinfo *hashinfo,
@@ -453,10 +462,6 @@ static inline struct sock *__inet_lookup_skb(struct inet_hashinfo *hashinfo,
refcounted);
}
-u32 inet6_ehashfn(const struct net *net,
- const struct in6_addr *laddr, const u16 lport,
- const struct in6_addr *faddr, const __be16 fport);
-
static inline void sk_daddr_set(struct sock *sk, __be32 addr)
{
sk->sk_daddr = addr; /* alias of inet_daddr */
diff --git a/include/net/udp.h b/include/net/udp.h
index 5cad44318d71..3b404b429f88 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -317,6 +317,14 @@ struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport);
int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor);
+INDIRECT_CALLABLE_DECLARE(u32 udp_ehashfn(const struct net *,
+ const __be32, const __u16,
+ const __be32, const __be16));
+
+INDIRECT_CALLABLE_DECLARE(u32 udp6_ehashfn(const struct net *,
+ const struct in6_addr *, const u16,
+ const struct in6_addr *, const __be16));
+
/* UDP uses skb->dev_scratch to cache as much information as possible and avoid
* possibly multiple cache miss on dequeue()
*/
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 91f9210d4e83..0dd768ab22d9 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -28,9 +28,9 @@
#include <net/tcp.h>
#include <net/sock_reuseport.h>
-static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
- const __u16 lport, const __be32 faddr,
- const __be16 fport)
+u32 inet_ehashfn(const struct net *net, const __be32 laddr,
+ const __u16 lport, const __be32 faddr,
+ const __be16 fport)
{
static u32 inet_ehash_secret __read_mostly;
@@ -39,6 +39,7 @@ static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
return __inet_ehashfn(laddr, lport, faddr, fport,
inet_ehash_secret + net_hash_mix(net));
}
+EXPORT_SYMBOL_GPL(inet_ehashfn);
/* This function handles inet_sock, but also timewait and request sockets
* for IPv4/IPv6.
@@ -332,6 +333,10 @@ static inline int compute_score(struct sock *sk, struct net *net,
return score;
}
+INDIRECT_CALLABLE_DECLARE(u32 udp_ehashfn(const struct net *,
+ const __be32, const __u16,
+ const __be32, const __be16));
+
/**
* inet_lookup_reuseport() - execute reuseport logic on AF_INET socket if necessary.
* @net: network namespace.
@@ -342,6 +347,7 @@ static inline int compute_score(struct sock *sk, struct net *net,
* @sport: source port.
* @daddr: destination address.
* @hnum: destination port in host byte order.
+ * @ehashfn: hash function used to generate the fallback hash.
*
* Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
* the selected sock or an error.
@@ -349,13 +355,15 @@ static inline int compute_score(struct sock *sk, struct net *net,
struct sock *inet_lookup_reuseport(struct net *net, struct sock *sk,
struct sk_buff *skb, int doff,
__be32 saddr, __be16 sport,
- __be32 daddr, unsigned short hnum)
+ __be32 daddr, unsigned short hnum,
+ inet_ehashfn_t ehashfn)
{
struct sock *reuse_sk = NULL;
u32 phash;
if (sk->sk_reuseport) {
- phash = inet_ehashfn(net, daddr, hnum, saddr, sport);
+ phash = INDIRECT_CALL_2(ehashfn, udp_ehashfn, inet_ehashfn,
+ net, daddr, hnum, saddr, sport);
reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
}
return reuse_sk;
@@ -385,7 +393,7 @@ static struct sock *inet_lhash2_lookup(struct net *net,
score = compute_score(sk, net, hnum, daddr, dif, sdif);
if (score > hiscore) {
result = inet_lookup_reuseport(net, sk, skb, doff,
- saddr, sport, daddr, hnum);
+ saddr, sport, daddr, hnum, inet_ehashfn);
if (result)
return result;
@@ -414,7 +422,8 @@ static inline struct sock *inet_lookup_run_bpf(struct net *net,
if (no_reuseport || IS_ERR_OR_NULL(sk))
return sk;
- reuse_sk = inet_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
+ reuse_sk = inet_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum,
+ inet_ehashfn);
if (reuse_sk)
sk = reuse_sk;
return sk;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 5ef478d2c408..7258edece691 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -405,9 +405,9 @@ static int compute_score(struct sock *sk, struct net *net,
return score;
}
-static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
- const __u16 lport, const __be32 faddr,
- const __be16 fport)
+INDIRECT_CALLABLE_SCOPE
+u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,
+ const __be32 faddr, const __be16 fport)
{
static u32 udp_ehash_secret __read_mostly;
@@ -417,22 +417,6 @@ static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
udp_ehash_secret + net_hash_mix(net));
}
-static struct sock *lookup_reuseport(struct net *net, struct sock *sk,
- struct sk_buff *skb,
- __be32 saddr, __be16 sport,
- __be32 daddr, unsigned short hnum)
-{
- struct sock *reuse_sk = NULL;
- u32 hash;
-
- if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
- hash = udp_ehashfn(net, daddr, hnum, saddr, sport);
- reuse_sk = reuseport_select_sock(sk, hash, skb,
- sizeof(struct udphdr));
- }
- return reuse_sk;
-}
-
/* called with rcu_read_lock() */
static struct sock *udp4_lib_lookup2(struct net *net,
__be32 saddr, __be16 sport,
@@ -451,7 +435,14 @@ static struct sock *udp4_lib_lookup2(struct net *net,
daddr, hnum, dif, sdif);
if (score > badness) {
badness = score;
- result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
+
+ if (sk->sk_state == TCP_ESTABLISHED) {
+ result = sk;
+ continue;
+ }
+
+ result = inet_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
+ saddr, sport, daddr, hnum, udp_ehashfn);
if (!result) {
result = sk;
continue;
@@ -490,7 +481,8 @@ static struct sock *udp4_lookup_run_bpf(struct net *net,
if (no_reuseport || IS_ERR_OR_NULL(sk))
return sk;
- reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
+ reuse_sk = inet_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
+ saddr, sport, daddr, hnum, udp_ehashfn);
if (reuse_sk)
sk = reuse_sk;
return sk;
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index 208998694ae3..b5de1642bc51 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -39,6 +39,7 @@ u32 inet6_ehashfn(const struct net *net,
return __inet6_ehashfn(lhash, lport, fhash, fport,
inet6_ehash_secret + net_hash_mix(net));
}
+EXPORT_SYMBOL_GPL(inet6_ehashfn);
/*
* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
@@ -111,6 +112,10 @@ static inline int compute_score(struct sock *sk, struct net *net,
return score;
}
+INDIRECT_CALLABLE_DECLARE(u32 udp6_ehashfn(const struct net *,
+ const struct in6_addr *, const u16,
+ const struct in6_addr *, const __be16));
+
/**
* inet6_lookup_reuseport() - execute reuseport logic on AF_INET6 socket if necessary.
* @net: network namespace.
@@ -121,6 +126,7 @@ static inline int compute_score(struct sock *sk, struct net *net,
* @sport: source port.
* @daddr: destination address.
* @hnum: destination port in host byte order.
+ * @ehashfn: hash function used to generate the fallback hash.
*
* Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
* the selected sock or an error.
@@ -130,13 +136,15 @@ struct sock *inet6_lookup_reuseport(struct net *net, struct sock *sk,
const struct in6_addr *saddr,
__be16 sport,
const struct in6_addr *daddr,
- unsigned short hnum)
+ unsigned short hnum,
+ inet6_ehashfn_t ehashfn)
{
struct sock *reuse_sk = NULL;
u32 phash;
if (sk->sk_reuseport) {
- phash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
+ phash = INDIRECT_CALL_INET(ehashfn, udp6_ehashfn, inet6_ehashfn,
+ net, daddr, hnum, saddr, sport);
reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
}
return reuse_sk;
@@ -159,7 +167,7 @@ static struct sock *inet6_lhash2_lookup(struct net *net,
score = compute_score(sk, net, hnum, daddr, dif, sdif);
if (score > hiscore) {
result = inet6_lookup_reuseport(net, sk, skb, doff,
- saddr, sport, daddr, hnum);
+ saddr, sport, daddr, hnum, inet6_ehashfn);
if (result)
return result;
@@ -190,7 +198,8 @@ static inline struct sock *inet6_lookup_run_bpf(struct net *net,
if (no_reuseport || IS_ERR_OR_NULL(sk))
return sk;
- reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
+ reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
+ saddr, sport, daddr, hnum, inet6_ehashfn);
if (reuse_sk)
sk = reuse_sk;
return sk;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 8b3cb1d7da7c..ebac9200b15c 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -70,11 +70,12 @@ int udpv6_init_sock(struct sock *sk)
return 0;
}
-static u32 udp6_ehashfn(const struct net *net,
- const struct in6_addr *laddr,
- const u16 lport,
- const struct in6_addr *faddr,
- const __be16 fport)
+INDIRECT_CALLABLE_SCOPE
+u32 udp6_ehashfn(const struct net *net,
+ const struct in6_addr *laddr,
+ const u16 lport,
+ const struct in6_addr *faddr,
+ const __be16 fport)
{
static u32 udp6_ehash_secret __read_mostly;
static u32 udp_ipv6_hash_secret __read_mostly;
@@ -159,24 +160,6 @@ static int compute_score(struct sock *sk, struct net *net,
return score;
}
-static struct sock *lookup_reuseport(struct net *net, struct sock *sk,
- struct sk_buff *skb,
- const struct in6_addr *saddr,
- __be16 sport,
- const struct in6_addr *daddr,
- unsigned int hnum)
-{
- struct sock *reuse_sk = NULL;
- u32 hash;
-
- if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
- hash = udp6_ehashfn(net, daddr, hnum, saddr, sport);
- reuse_sk = reuseport_select_sock(sk, hash, skb,
- sizeof(struct udphdr));
- }
- return reuse_sk;
-}
-
/* called with rcu_read_lock() */
static struct sock *udp6_lib_lookup2(struct net *net,
const struct in6_addr *saddr, __be16 sport,
@@ -194,7 +177,14 @@ static struct sock *udp6_lib_lookup2(struct net *net,
daddr, hnum, dif, sdif);
if (score > badness) {
badness = score;
- result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
+
+ if (sk->sk_state == TCP_ESTABLISHED) {
+ result = sk;
+ continue;
+ }
+
+ result = inet6_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
+ saddr, sport, daddr, hnum, udp6_ehashfn);
if (!result) {
result = sk;
continue;
@@ -234,7 +224,8 @@ static inline struct sock *udp6_lookup_run_bpf(struct net *net,
if (no_reuseport || IS_ERR_OR_NULL(sk))
return sk;
- reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
+ reuse_sk = inet6_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
+ saddr, sport, daddr, hnum, udp6_ehashfn);
if (reuse_sk)
sk = reuse_sk;
return sk;
--
2.40.1