inet: Sanitize inet{,6} protocol demux.

Don't pretend that inet_protos[] and inet6_protos[] are hashes, thay
are just a straight arrays.  Remove all unnecessary hash masking.

Document MAX_INET_PROTOS.

Use RAW_HTABLE_SIZE when appropriate.

Reported-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/protocol.h b/include/net/protocol.h
index 875f4895b0332cb95678eb1278fc9dd4a2ba5fe2..a1b1b530c33892d34e694d04010ba81fe9babf21 100644 (file)
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -29,8 +29,11 @@
 #include <linux/ipv6.h>
 #endif
 
-#define MAX_INET_PROTOS        256             /* Must be a power of 2         */
-
+/* This is one larger than the largest protocol value that can be
+ * found in an ipv4 or ipv6 header.  Since in both cases the protocol
+ * value is presented in a __u8, this is defined to be 256.
+ */
+#define MAX_INET_PROTOS                256
 
 /* This is used to register protocols. */
 struct net_protocol {

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index e4e8e00a2c9104b4495970def34326dd4ab78b75..85a3b17631369e1b57adc94e6ae662a37a047eb4 100644 (file)
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -242,20 +242,18 @@ void build_ehash_secret(void)
 }
 EXPORT_SYMBOL(build_ehash_secret);
 
-static inline int inet_netns_ok(struct net *net, int protocol)
+static inline int inet_netns_ok(struct net *net, __u8 protocol)
 {
-       int hash;
        const struct net_protocol *ipprot;
 
        if (net_eq(net, &init_net))
                return 1;
 
-       hash = protocol & (MAX_INET_PROTOS - 1);
-       ipprot = rcu_dereference(inet_protos[hash]);
-
-       if (ipprot == NULL)
+       ipprot = rcu_dereference(inet_protos[protocol]);
+       if (ipprot == NULL) {
                /* raw IP is OK */
                return 1;
+       }
        return ipprot->netns_ok;
 }
 
@@ -1216,8 +1214,8 @@ EXPORT_SYMBOL(inet_sk_rebuild_header);
 
 static int inet_gso_send_check(struct sk_buff *skb)
 {
-       const struct iphdr *iph;
        const struct net_protocol *ops;
+       const struct iphdr *iph;
        int proto;
        int ihl;
        int err = -EINVAL;
@@ -1236,7 +1234,7 @@ static int inet_gso_send_check(struct sk_buff *skb)
        __skb_pull(skb, ihl);
        skb_reset_transport_header(skb);
        iph = ip_hdr(skb);
-       proto = iph->protocol & (MAX_INET_PROTOS - 1);
+       proto = iph->protocol;
        err = -EPROTONOSUPPORT;
 
        rcu_read_lock();
@@ -1253,8 +1251,8 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
        netdev_features_t features)
 {
        struct sk_buff *segs = ERR_PTR(-EINVAL);
-       struct iphdr *iph;
        const struct net_protocol *ops;
+       struct iphdr *iph;
        int proto;
        int ihl;
        int id;
@@ -1286,7 +1284,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
        skb_reset_transport_header(skb);
        iph = ip_hdr(skb);
        id = ntohs(iph->id);
-       proto = iph->protocol & (MAX_INET_PROTOS - 1);
+       proto = iph->protocol;
        segs = ERR_PTR(-EPROTONOSUPPORT);
 
        rcu_read_lock();
@@ -1340,7 +1338,7 @@ static struct sk_buff **inet_gro_receive(struct sk_buff **head,
                        goto out;
        }
 
-       proto = iph->protocol & (MAX_INET_PROTOS - 1);
+       proto = iph->protocol;
 
        rcu_read_lock();
        ops = rcu_dereference(inet_protos[proto]);
@@ -1398,11 +1396,11 @@ out:
 
 static int inet_gro_complete(struct sk_buff *skb)
 {
-       const struct net_protocol *ops;
+       __be16 newlen = htons(skb->len - skb_network_offset(skb));
        struct iphdr *iph = ip_hdr(skb);
-       int proto = iph->protocol & (MAX_INET_PROTOS - 1);
+       const struct net_protocol *ops;
+       int proto = iph->protocol;
        int err = -ENOSYS;
-       __be16 newlen = htons(skb->len - skb_network_offset(skb));
 
        csum_replace2(&iph->check, iph->tot_len, newlen);
        iph->tot_len = newlen;

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index e1caa1abe5d15355cc8fef33461cbafaabffcfb7..49a74cc79dc89ee1e07d129a6f23e6a027552c2b 100644 (file)
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -637,12 +637,12 @@ EXPORT_SYMBOL(icmp_send);
 
 static void icmp_unreach(struct sk_buff *skb)
 {
+       const struct net_protocol *ipprot;
        const struct iphdr *iph;
        struct icmphdr *icmph;
-       int hash, protocol;
-       const struct net_protocol *ipprot;
-       u32 info = 0;
        struct net *net;
+       u32 info = 0;
+       int protocol;
 
        net = dev_net(skb_dst(skb)->dev);
 
@@ -731,9 +731,8 @@ static void icmp_unreach(struct sk_buff *skb)
         */
        raw_icmp_error(skb, protocol, info);
 
-       hash = protocol & (MAX_INET_PROTOS - 1);
        rcu_read_lock();
-       ipprot = rcu_dereference(inet_protos[hash]);
+       ipprot = rcu_dereference(inet_protos[protocol]);
        if (ipprot && ipprot->err_handler)
                ipprot->err_handler(skb, info);
        rcu_read_unlock();

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 8590144ca3303ad99cb2c59a6eeef00ae12e2ffa..c4fe1d2711310a23f7fcc7e4c8934d053904eb92 100644 (file)
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -198,14 +198,13 @@ static int ip_local_deliver_finish(struct sk_buff *skb)
        rcu_read_lock();
        {
                int protocol = ip_hdr(skb)->protocol;
-               int hash, raw;
                const struct net_protocol *ipprot;
+               int raw;
 
        resubmit:
                raw = raw_local_deliver(skb, protocol);
 
-               hash = protocol & (MAX_INET_PROTOS - 1);
-               ipprot = rcu_dereference(inet_protos[hash]);
+               ipprot = rcu_dereference(inet_protos[protocol]);
                if (ipprot != NULL) {
                        int ret;
 

diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c
index 9ae5c01cd0b2b8da2e243c08d2597dd012e96995..8918eff1426d2e5da3aeaa41cb4d34824482da5a 100644 (file)
--- a/net/ipv4/protocol.c
+++ b/net/ipv4/protocol.c
@@ -36,9 +36,7 @@ const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
 
 int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
 {
-       int hash = protocol & (MAX_INET_PROTOS - 1);
-
-       return !cmpxchg((const struct net_protocol **)&inet_protos[hash],
+       return !cmpxchg((const struct net_protocol **)&inet_protos[protocol],
                        NULL, prot) ? 0 : -1;
 }
 EXPORT_SYMBOL(inet_add_protocol);
@@ -49,9 +47,9 @@ EXPORT_SYMBOL(inet_add_protocol);
 
 int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
 {
-       int ret, hash = protocol & (MAX_INET_PROTOS - 1);
+       int ret;
 
-       ret = (cmpxchg((const struct net_protocol **)&inet_protos[hash],
+       ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol],
                       prot, NULL) == prot) ? 0 : -1;
 
        synchronize_net();

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 5247d5c211f95a765e22e04b79d95cc0cfe1ad6a..c7da1422cbde63af314c7b12d9ee6851723d5a51 100644 (file)
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -600,9 +600,8 @@ static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
 {
        const struct inet6_protocol *ipprot;
        int inner_offset;
-       int hash;
-       u8 nexthdr;
        __be16 frag_off;
+       u8 nexthdr;
 
        if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
                return;
@@ -629,10 +628,8 @@ static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
           --ANK (980726)
         */
 
-       hash = nexthdr & (MAX_INET_PROTOS - 1);
-
        rcu_read_lock();
-       ipprot = rcu_dereference(inet6_protos[hash]);
+       ipprot = rcu_dereference(inet6_protos[nexthdr]);
        if (ipprot && ipprot->err_handler)
                ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
        rcu_read_unlock();

diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 21a15dfe4a9e86d85bd9793a4b507861a6a705ea..5ab923e51af3d4232afe9ea56af0933b7dcb8b9c 100644 (file)
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -168,13 +168,12 @@ drop:
 
 static int ip6_input_finish(struct sk_buff *skb)
 {
+       struct net *net = dev_net(skb_dst(skb)->dev);
        const struct inet6_protocol *ipprot;
+       struct inet6_dev *idev;
        unsigned int nhoff;
        int nexthdr;
        bool raw;
-       u8 hash;
-       struct inet6_dev *idev;
-       struct net *net = dev_net(skb_dst(skb)->dev);
 
        /*
         *      Parse extension headers
@@ -189,9 +188,7 @@ resubmit:
        nexthdr = skb_network_header(skb)[nhoff];
 
        raw = raw6_local_deliver(skb, nexthdr);
-
-       hash = nexthdr & (MAX_INET_PROTOS - 1);
-       if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
+       if ((ipprot = rcu_dereference(inet6_protos[nexthdr])) != NULL) {
                int ret;
 
                if (ipprot->flags & INET6_PROTO_FINAL) {

diff --git a/net/ipv6/protocol.c b/net/ipv6/protocol.c
index 9a7978fdc02a5de453feb7c4ca1ea9c1e7652292..053082dfc93e1f9d0c98e26e9c083fc384ed06d5 100644 (file)
--- a/net/ipv6/protocol.c
+++ b/net/ipv6/protocol.c
@@ -29,9 +29,7 @@ const struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS] __read_mostly;
 
 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char protocol)
 {
-       int hash = protocol & (MAX_INET_PROTOS - 1);
-
-       return !cmpxchg((const struct inet6_protocol **)&inet6_protos[hash],
+       return !cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
                        NULL, prot) ? 0 : -1;
 }
 EXPORT_SYMBOL(inet6_add_protocol);
@@ -42,9 +40,9 @@ EXPORT_SYMBOL(inet6_add_protocol);
 
 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char protocol)
 {
-       int ret, hash = protocol & (MAX_INET_PROTOS - 1);
+       int ret;
 
-       ret = (cmpxchg((const struct inet6_protocol **)&inet6_protos[hash],
+       ret = (cmpxchg((const struct inet6_protocol **)&inet6_protos[protocol],
                       prot, NULL) == prot) ? 0 : -1;
 
        synchronize_net();

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 43b0042f15f4aae7536faf4eb52064a1c785c291..b5c1dcb277370f09039ba4fd34dc596644b6114e 100644 (file)
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -165,7 +165,7 @@ static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr)
        saddr = &ipv6_hdr(skb)->saddr;
        daddr = saddr + 1;
 
-       hash = nexthdr & (MAX_INET_PROTOS - 1);
+       hash = nexthdr & (RAW_HTABLE_SIZE - 1);
 
        read_lock(&raw_v6_hashinfo.lock);
        sk = sk_head(&raw_v6_hashinfo.ht[hash]);
@@ -229,7 +229,7 @@ bool raw6_local_deliver(struct sk_buff *skb, int nexthdr)
 {
        struct sock *raw_sk;
 
-       raw_sk = sk_head(&raw_v6_hashinfo.ht[nexthdr & (MAX_INET_PROTOS - 1)]);
+       raw_sk = sk_head(&raw_v6_hashinfo.ht[nexthdr & (RAW_HTABLE_SIZE - 1)]);
        if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))
                raw_sk = NULL;