From 1bbdceef1e535add893bf71d7b7ab102e4eb69eb Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Sat, 19 Oct 2013 21:48:57 +0200 Subject: inet: convert inet_ehash_secret and ipv6_hash_secret to net_get_random_once Initialize the ehash and ipv6_hash_secrets with net_get_random_once. Each compilation unit gets its own secret now: ipv4/inet_hashtables.o ipv4/udp.o ipv6/inet6_hashtables.o ipv6/udp.o rds/connection.o The functions still get inlined into the hashing functions. In the fast path we have at most two (needed in ipv6) if (unlikely(...)). Cc: Eric Dumazet Cc: "David S. Miller" Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/ipv4/af_inet.c | 27 --------------------------- net/ipv4/inet_hashtables.c | 4 ++++ net/ipv4/udp.c | 6 +++++- net/ipv6/af_inet6.c | 5 ----- net/ipv6/inet6_hashtables.c | 15 ++++++++++++--- net/ipv6/udp.c | 17 ++++++++++++++--- net/rds/connection.c | 12 +++++++++--- 7 files changed, 44 insertions(+), 42 deletions(-) (limited to 'net') diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 4049906010f7..9433a6186f54 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -245,29 +245,6 @@ out: } EXPORT_SYMBOL(inet_listen); -u32 inet_ehash_secret __read_mostly; -EXPORT_SYMBOL(inet_ehash_secret); - -u32 ipv6_hash_secret __read_mostly; -EXPORT_SYMBOL(ipv6_hash_secret); - -/* - * inet_ehash_secret must be set exactly once, and to a non nul value - * ipv6_hash_secret must be set exactly once. - */ -void build_ehash_secret(void) -{ - u32 rnd; - - do { - get_random_bytes(&rnd, sizeof(rnd)); - } while (rnd == 0); - - if (cmpxchg(&inet_ehash_secret, 0, rnd) == 0) - get_random_bytes(&ipv6_hash_secret, sizeof(ipv6_hash_secret)); -} -EXPORT_SYMBOL(build_ehash_secret); - /* * Create an inet socket. */ @@ -284,10 +261,6 @@ static int inet_create(struct net *net, struct socket *sock, int protocol, int try_loading_module = 0; int err; - if (unlikely(!inet_ehash_secret)) - if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) - build_ehash_secret(); - sock->state = SS_UNCONNECTED; /* Look for the requested type/protocol pair. */ diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 18aa668d0cc9..8b9cf279450d 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -28,6 +28,10 @@ static unsigned int inet_ehashfn(struct net *net, const __be32 laddr, const __u16 lport, const __be32 faddr, const __be16 fport) { + static u32 inet_ehash_secret __read_mostly; + + net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret)); + return __inet_ehashfn(laddr, lport, faddr, fport, inet_ehash_secret + net_hash_mix(net)); } diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index b4437c7db6ce..89909dd730dd 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -411,8 +411,12 @@ static unsigned int udp_ehashfn(struct net *net, const __be32 laddr, const __u16 lport, const __be32 faddr, const __be16 fport) { + static u32 udp_ehash_secret __read_mostly; + + net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret)); + return __inet_ehashfn(laddr, lport, faddr, fport, - inet_ehash_secret + net_hash_mix(net)); + udp_ehash_secret + net_hash_mix(net)); } diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index a2cb07cd3850..20af1fb81c83 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -110,11 +110,6 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol, int try_loading_module = 0; int err; - if (sock->type != SOCK_RAW && - sock->type != SOCK_DGRAM && - !inet_ehash_secret) - build_ehash_secret(); - /* Look for the requested type/protocol pair. */ lookup_protocol: err = -ESOCKTNOSUPPORT; diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c index fa7dd3856c55..262e13c02ec2 100644 --- a/net/ipv6/inet6_hashtables.c +++ b/net/ipv6/inet6_hashtables.c @@ -29,10 +29,19 @@ static unsigned int inet6_ehashfn(struct net *net, const struct in6_addr *faddr, const __be16 fport) { - const u32 lhash = (__force u32)laddr->s6_addr32[3]; - const u32 fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret); + static u32 inet6_ehash_secret __read_mostly; + static u32 ipv6_hash_secret __read_mostly; + + u32 lhash, fhash; + + net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret)); + net_get_random_once(&ipv6_hash_secret, sizeof(ipv6_hash_secret)); + + lhash = (__force u32)laddr->s6_addr32[3]; + fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret); + return __inet6_ehashfn(lhash, lport, fhash, fport, - inet_ehash_secret + net_hash_mix(net)); + inet6_ehash_secret + net_hash_mix(net)); } static int inet6_sk_ehashfn(const struct sock *sk) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 324bd36c23bc..44fc4e3d661f 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -59,10 +59,21 @@ static unsigned int udp6_ehashfn(struct net *net, const struct in6_addr *faddr, const __be16 fport) { - const u32 lhash = (__force u32)laddr->s6_addr32[3]; - const u32 fhash = __ipv6_addr_jhash(faddr, ipv6_hash_secret); + static u32 udp6_ehash_secret __read_mostly; + static u32 udp_ipv6_hash_secret __read_mostly; + + u32 lhash, fhash; + + net_get_random_once(&udp6_ehash_secret, + sizeof(udp6_ehash_secret)); + net_get_random_once(&udp_ipv6_hash_secret, + sizeof(udp_ipv6_hash_secret)); + + lhash = (__force u32)laddr->s6_addr32[3]; + fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret); + return __inet6_ehashfn(lhash, lport, fhash, fport, - inet_ehash_secret + net_hash_mix(net)); + udp_ipv6_hash_secret + net_hash_mix(net)); } int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2) diff --git a/net/rds/connection.c b/net/rds/connection.c index 45e23660437a..378c3a6acf84 100644 --- a/net/rds/connection.c +++ b/net/rds/connection.c @@ -51,10 +51,16 @@ static struct kmem_cache *rds_conn_slab; static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr) { + static u32 rds_hash_secret __read_mostly; + + unsigned long hash; + + net_get_random_once(&rds_hash_secret, sizeof(rds_hash_secret)); + /* Pass NULL, don't need struct net for hash */ - unsigned long hash = __inet_ehashfn(be32_to_cpu(laddr), 0, - be32_to_cpu(faddr), 0, - inet_ehash_secret); + hash = __inet_ehashfn(be32_to_cpu(laddr), 0, + be32_to_cpu(faddr), 0, + rds_hash_secret); return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK]; } -- cgit v1.2.3-59-g8ed1b