net: pppoe - code cleanup and helpers

- Introduce PPPOE_HASH_MASK.
- Remove redundant declaration of pppoe_chan_ops.
- Introduce stage_session helper.
- Tabs, space, long-line-split cleanup.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 86 insertions, 81 deletions

diff --git a/drivers/net/pppoe.c b/drivers/net/pppoe.c
index 5efc3d172c8..c2ceea4f46b 100644
--- a/drivers/net/pppoe.c
+++ b/drivers/net/pppoe.c
@@ -84,32 +84,43 @@
 #include <asm/uaccess.h>
 
 #define PPPOE_HASH_BITS 4
-#define PPPOE_HASH_SIZE (1<<PPPOE_HASH_BITS)
-
-static struct ppp_channel_ops pppoe_chan_ops;
+#define PPPOE_HASH_SIZE (1 << PPPOE_HASH_BITS)
+#define PPPOE_HASH_MASK (PPPOE_HASH_SIZE - 1)
 
 static int pppoe_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb);
 static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb);
 
 static const struct proto_ops pppoe_ops;
+static struct ppp_channel_ops pppoe_chan_ops;
 static DEFINE_RWLOCK(pppoe_hash_lock);
 
-static struct ppp_channel_ops pppoe_chan_ops;
+/*
+ * PPPoE could be in the following stages:
+ * 1) Discovery stage (to obtain remote MAC and Session ID)
+ * 2) Session stage (MAC and SID are known)
+ *
+ * Ethernet frames have a special tag for this but
+ * we use simplier approach based on session id
+ */
+static inline bool stage_session(__be16 sid)
+{
+        return sid != 0;
+}
 
 static inline int cmp_2_addr(struct pppoe_addr *a, struct pppoe_addr *b)
 {
-        return (a->sid == b->sid &&
-                (memcmp(a->remote, b->remote, ETH_ALEN) == 0));
+        return a->sid == b->sid &&
+                (memcmp(a->remote, b->remote, ETH_ALEN) == 0);
 }
 
 static inline int cmp_addr(struct pppoe_addr *a, __be16 sid, char *addr)
 {
-        return (a->sid == sid &&
-                (memcmp(a->remote,addr,ETH_ALEN) == 0));
+        return a->sid == sid &&
+                (memcmp(a->remote, addr, ETH_ALEN) == 0);
 }
 
-#if 8%PPPOE_HASH_BITS
+#if 8 % PPPOE_HASH_BITS
 #error 8 must be a multiple of PPPOE_HASH_BITS
 #endif
 
@@ -118,17 +129,14 @@ static int hash_item(__be16 sid, unsigned char *addr)
         unsigned char hash = 0;
         unsigned int i;
 
-        for (i = 0 ; i < ETH_ALEN ; i++) {
+        for (i = 0; i < ETH_ALEN; i++)
                 hash ^= addr[i];
-        }
-        for (i = 0 ; i < sizeof(sid_t)*8 ; i += 8 ){
-                hash ^= (__force __u32)sid>>i;
-        }
-        for (i = 8 ; (i>>=1) >= PPPOE_HASH_BITS ; ) {
-                hash ^= hash>>i;
-        }
+        for (i = 0; i < sizeof(sid_t) * 8; i += 8)
+                hash ^= (__force __u32)sid >> i;
+        for (i = 8; (i >>= 1) >= PPPOE_HASH_BITS;)
+                hash ^= hash >> i;
 
-        return hash & ( PPPOE_HASH_SIZE - 1 );
+        return hash & PPPOE_HASH_MASK;
 }
 
 /* zeroed because its in .bss */
@@ -146,10 +154,15 @@ static struct pppox_sock *__get_item(__be16 sid, unsigned char *addr, int ifinde
 
         ret = item_hash_table[hash];
 
-        while (ret && !(cmp_addr(&ret->pppoe_pa, sid, addr) && ret->pppoe_ifindex == ifindex))
+        while (ret) {
+                if (cmp_addr(&ret->pppoe_pa, sid, addr) &&
+                    ret->pppoe_ifindex == ifindex)
+                        return ret;
+
                 ret = ret->next;
+        }
 
-        return ret;
+        return NULL;
 }
 
 static int __set_item(struct pppox_sock *po)
@@ -159,7 +172,8 @@ static int __set_item(struct pppox_sock *po)
 
         ret = item_hash_table[hash];
         while (ret) {
-                if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) && ret->pppoe_ifindex == po->pppoe_ifindex)
+                if (cmp_2_addr(&ret->pppoe_pa, &po->pppoe_pa) &&
+                    ret->pppoe_ifindex == po->pppoe_ifindex)
                         return -EALREADY;
 
                 ret = ret->next;
@@ -180,7 +194,8 @@ static struct pppox_sock *__delete_item(__be16 sid, char *addr, int ifindex)
         src = &item_hash_table[hash];
 
         while (ret) {
-                if (cmp_addr(&ret->pppoe_pa, sid, addr) && ret->pppoe_ifindex == ifindex) {
+                if (cmp_addr(&ret->pppoe_pa, sid, addr) &&
+                    ret->pppoe_ifindex == ifindex) {
                         *src = ret->next;
                         break;
                 }
@@ -217,7 +232,7 @@ static inline struct pppox_sock *get_item_by_addr(struct sockaddr_pppox *sp)
         int ifindex;
 
         dev = dev_get_by_name(&init_net, sp->sa_addr.pppoe.dev);
-        if(!dev)
+        if (!dev)
                 return NULL;
         ifindex = dev->ifindex;
         dev_put(dev);
@@ -329,7 +344,6 @@ static struct notifier_block pppoe_notifier = {
         .notifier_call = pppoe_device_event,
 };
 
-
 /************************************************************************
  *
  * Do the real work of receiving a PPPoE Session frame.
@@ -383,7 +397,8 @@ static int pppoe_rcv(struct sk_buff *skb,
         struct pppox_sock *po;
         int len;
 
-        if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
+        skb = skb_share_check(skb, GFP_ATOMIC);
+        if (!skb)
                 goto out;
 
         if (dev_net(dev) != &init_net)
@@ -432,7 +447,8 @@ static int pppoe_disc_rcv(struct sk_buff *skb,
         if (dev_net(dev) != &init_net)
                 goto abort;
 
-        if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
+        skb = skb_share_check(skb, GFP_ATOMIC);
+        if (!skb)
                 goto out;
 
         if (!pskb_may_pull(skb, sizeof(struct pppoe_hdr)))
@@ -493,12 +509,11 @@ static struct proto pppoe_sk_proto = {
  **********************************************************************/
 static int pppoe_create(struct net *net, struct socket *sock)
 {
-        int error = -ENOMEM;
         struct sock *sk;
 
         sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppoe_sk_proto);
         if (!sk)
-                goto out;
+                return -ENOMEM;
 
         sock_init_data(sock, sk);
 
@@ -511,8 +526,7 @@ static int pppoe_create(struct net *net, struct socket *sock)
         sk->sk_family      = PF_PPPOX;
         sk->sk_protocol    = PX_PROTO_OE;
 
-        error = 0;
-out:    return error;
+        return 0;
 }
 
 static int pppoe_release(struct socket *sock)
@@ -524,7 +538,7 @@ static int pppoe_release(struct socket *sock)
                 return 0;
 
         lock_sock(sk);
-        if (sock_flag(sk, SOCK_DEAD)){
+        if (sock_flag(sk, SOCK_DEAD)) {
                 release_sock(sk);
                 return -EBADF;
         }
@@ -542,7 +556,7 @@ static int pppoe_release(struct socket *sock)
         write_lock_bh(&pppoe_hash_lock);
 
         po = pppox_sk(sk);
-        if (po->pppoe_pa.sid) {
+        if (stage_session(po->pppoe_pa.sid)) {
                 __delete_item(po->pppoe_pa.sid,
                               po->pppoe_pa.remote, po->pppoe_ifindex);
         }
@@ -564,7 +578,6 @@ static int pppoe_release(struct socket *sock)
         return 0;
 }
 
-
 static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
                   int sockaddr_len, int flags)
 {
@@ -582,32 +595,31 @@ static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
 
         /* Check for already bound sockets */
         error = -EBUSY;
-        if ((sk->sk_state & PPPOX_CONNECTED) && sp->sa_addr.pppoe.sid)
+        if ((sk->sk_state & PPPOX_CONNECTED) &&
+             stage_session(sp->sa_addr.pppoe.sid))
                 goto end;
 
         /* Check for already disconnected sockets, on attempts to disconnect */
         error = -EALREADY;
-        if ((sk->sk_state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
+        if ((sk->sk_state & PPPOX_DEAD) &&
+             !stage_session(sp->sa_addr.pppoe.sid))
                 goto end;
 
         error = 0;
-        if (po->pppoe_pa.sid) {
-                pppox_unbind_sock(sk);
 
-                /* Delete the old binding */
-                delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote,po->pppoe_ifindex);
-
-                if(po->pppoe_dev)
+        /* Delete the old binding */
+        if (stage_session(po->pppoe_pa.sid)) {
+                pppox_unbind_sock(sk);
+                delete_item(po->pppoe_pa.sid, po->pppoe_pa.remote, po->pppoe_ifindex);
+                if (po->pppoe_dev)
                         dev_put(po->pppoe_dev);
-
                 memset(sk_pppox(po) + 1, 0,
                        sizeof(struct pppox_sock) - sizeof(struct sock));
-
                 sk->sk_state = PPPOX_NONE;
         }
 
-        /* Don't re-bind if sid==0 */
-        if (sp->sa_addr.pppoe.sid != 0) {
+        /* Re-bind in session stage only */
+        if (stage_session(sp->sa_addr.pppoe.sid)) {
                 dev = dev_get_by_name(&init_net, sp->sa_addr.pppoe.dev);
 
                 error = -ENODEV;
@@ -618,7 +630,7 @@ static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
                 po->pppoe_ifindex = dev->ifindex;
 
                 write_lock_bh(&pppoe_hash_lock);
-                if (!(dev->flags & IFF_UP)){
+                if (!(dev->flags & IFF_UP)) {
                         write_unlock_bh(&pppoe_hash_lock);
                         goto err_put;
                 }
@@ -648,7 +660,7 @@ static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr,
 
         po->num = sp->sa_addr.pppoe.sid;
 
- end:
+end:
         release_sock(sk);
         return error;
 err_put:
@@ -659,7 +671,6 @@ err_put:
         goto end;
 }
 
-
 static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
                   int *usockaddr_len, int peer)
 {
@@ -678,7 +689,6 @@ static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
         return 0;
 }
 
-
 static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
                 unsigned long arg)
 {
@@ -709,7 +719,7 @@ static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
                         break;
 
                 err = -EFAULT;
-                if (get_user(val,(int __user *) arg))
+                if (get_user(val, (int __user *)arg))
                         break;
 
                 if (val < (po->pppoe_dev->mtu
@@ -722,7 +732,7 @@ static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
 
         case PPPIOCSFLAGS:
                 err = -EFAULT;
-                if (get_user(val, (int __user *) arg))
+                if (get_user(val, (int __user *)arg))
                         break;
                 err = 0;
                 break;
@@ -749,7 +759,7 @@ static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
 
                 err = -EINVAL;
                 if (po->pppoe_relay.sa_family != AF_PPPOX ||
-                    po->pppoe_relay.sa_protocol!= PX_PROTO_OE)
+                    po->pppoe_relay.sa_protocol != PX_PROTO_OE)
                         break;
 
                 /* Check that the socket referenced by the address
@@ -781,7 +791,6 @@ static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
         return err;
 }
 
-
 static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
                   struct msghdr *m, size_t total_len)
 {
@@ -808,7 +817,7 @@ static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
         dev = po->pppoe_dev;
 
         error = -EMSGSIZE;
-        if (total_len > (dev->mtu + dev->hard_header_len))
+        if (total_len > (dev->mtu + dev->hard_header_len))
                 goto end;
 
 
@@ -853,7 +862,6 @@ end:
         return error;
 }
 
-
 /************************************************************************
  *
  * xmit function for internal use.
@@ -903,7 +911,6 @@ abort:
         return 1;
 }
 
-
 /************************************************************************
  *
  * xmit function called by generic PPP driver
@@ -916,7 +923,6 @@ static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
         return __pppoe_xmit(sk, skb);
 }
 
-
 static struct ppp_channel_ops pppoe_chan_ops = {
         .start_xmit = pppoe_xmit,
 };
@@ -976,9 +982,9 @@ out:
 static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
 {
         struct pppox_sock *po;
-        int i = 0;
+        int i;
 
-        for (; i < PPPOE_HASH_SIZE; i++) {
+        for (i = 0; i < PPPOE_HASH_SIZE; i++) {
                 po = item_hash_table[i];
                 while (po) {
                         if (!pos--)
@@ -1064,32 +1070,31 @@ static inline int pppoe_proc_init(void) { return 0; }
 #endif /* CONFIG_PROC_FS */
 
 static const struct proto_ops pppoe_ops = {
-    .family             = AF_PPPOX,
-    .owner              = THIS_MODULE,
-    .release            = pppoe_release,
-    .bind               = sock_no_bind,
-    .connect            = pppoe_connect,
-    .socketpair         = sock_no_socketpair,
-    .accept             = sock_no_accept,
-    .getname            = pppoe_getname,
-    .poll               = datagram_poll,
-    .listen             = sock_no_listen,
-    .shutdown           = sock_no_shutdown,
-    .setsockopt         = sock_no_setsockopt,
-    .getsockopt         = sock_no_getsockopt,
-    .sendmsg            = pppoe_sendmsg,
-    .recvmsg            = pppoe_recvmsg,
-    .mmap               = sock_no_mmap,
-    .ioctl              = pppox_ioctl,
+        .family         = AF_PPPOX,
+        .owner          = THIS_MODULE,
+        .release        = pppoe_release,
+        .bind           = sock_no_bind,
+        .connect        = pppoe_connect,
+        .socketpair     = sock_no_socketpair,
+        .accept         = sock_no_accept,
+        .getname        = pppoe_getname,
+        .poll           = datagram_poll,
+        .listen         = sock_no_listen,
+        .shutdown       = sock_no_shutdown,
+        .setsockopt     = sock_no_setsockopt,
+        .getsockopt     = sock_no_getsockopt,
+        .sendmsg        = pppoe_sendmsg,
+        .recvmsg        = pppoe_recvmsg,
+        .mmap           = sock_no_mmap,
+        .ioctl          = pppox_ioctl,
 };
 
 static struct pppox_proto pppoe_proto = {
-    .create     = pppoe_create,
-    .ioctl      = pppoe_ioctl,
-    .owner      = THIS_MODULE,
+        .create = pppoe_create,
+        .ioctl  = pppoe_ioctl,
+        .owner  = THIS_MODULE,
 };
 
-
 static int __init pppoe_init(void)
 {
         int err = proto_register(&pppoe_sk_proto, 0);
@@ -1097,7 +1102,7 @@ static int __init pppoe_init(void)
         if (err)
                 goto out;
 
-        err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
+        err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
         if (err)
                 goto out_unregister_pppoe_proto;