1 files changed, 66 insertions, 13 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 6dc01bdeb76b..a6fa48788e8f 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -60,6 +60,7 @@
 #include <linux/netdevice.h>
 #include <linux/if_packet.h>
 #include <linux/wireless.h>
+#include <linux/kernel.h>
 #include <linux/kmod.h>
 #include <net/ip.h>
 #include <net/protocol.h>
@@ -200,7 +201,8 @@ struct packet_sock {
 #endif
         struct packet_type      prot_hook;
         spinlock_t              bind_lock;
-        char                    running;        /* prot_hook is attached*/
+        unsigned int            running:1,      /* prot_hook is attached*/
+                                auxdata:1;
         int                     ifindex;        /* bound device         */
         __be16                  num;
 #ifdef CONFIG_PACKET_MULTICAST
@@ -214,6 +216,16 @@ struct packet_sock {
 #endif
 };
 
+struct packet_skb_cb {
+        unsigned int origlen;
+        union {
+                struct sockaddr_pkt pkt;
+                struct sockaddr_ll ll;
+        } sa;
+};
+
+#define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
+
 #ifdef CONFIG_PACKET_MMAP
 
 static inline char *packet_lookup_frame(struct packet_sock *po, unsigned int position)
@@ -293,7 +305,7 @@ static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,  struct
         /* drop conntrack reference */
         nf_reset(skb);
 
-        spkt = (struct sockaddr_pkt*)skb->cb;
+        spkt = &PACKET_SKB_CB(skb)->sa.pkt;
 
         skb_push(skb, skb->data-skb->mac.raw);
 
@@ -512,7 +524,10 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, struct packet
                 skb = nskb;
         }
 
-        sll = (struct sockaddr_ll*)skb->cb;
+        BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
+                     sizeof(skb->cb));
+
+        sll = &PACKET_SKB_CB(skb)->sa.ll;
         sll->sll_family = AF_PACKET;
         sll->sll_hatype = dev->type;
         sll->sll_protocol = skb->protocol;
@@ -523,6 +538,8 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, struct packet
         if (dev->hard_header_parse)
                 sll->sll_halen = dev->hard_header_parse(skb, sll->sll_addr);
 
+        PACKET_SKB_CB(skb)->origlen = skb->len;
+
         if (pskb_trim(skb, snaplen))
                 goto drop_n_acct;
 
@@ -582,11 +599,12 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
                 else if (skb->pkt_type == PACKET_OUTGOING) {
                         /* Special case: outgoing packets have ll header at head */
                         skb_pull(skb, skb->nh.raw - skb->data);
-                        if (skb->ip_summed == CHECKSUM_PARTIAL)
-                                status |= TP_STATUS_CSUMNOTREADY;
                 }
         }
 
+        if (skb->ip_summed == CHECKSUM_PARTIAL)
+                status |= TP_STATUS_CSUMNOTREADY;
+
         snaplen = skb->len;
 
         res = run_filter(skb, sk, snaplen);
@@ -1092,7 +1110,7 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
          *      it in now.
          */
 
-        sll = (struct sockaddr_ll*)skb->cb;
+        sll = &PACKET_SKB_CB(skb)->sa.ll;
         if (sock->type == SOCK_PACKET)
                 msg->msg_namelen = sizeof(struct sockaddr_pkt);
         else
@@ -1117,7 +1135,22 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
         sock_recv_timestamp(msg, sk, skb);
 
         if (msg->msg_name)
-                memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
+                memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
+                       msg->msg_namelen);
+
+        if (pkt_sk(sk)->auxdata) {
+                struct tpacket_auxdata aux;
+
+                aux.tp_status = TP_STATUS_USER;
+                if (skb->ip_summed == CHECKSUM_PARTIAL)
+                        aux.tp_status |= TP_STATUS_CSUMNOTREADY;
+                aux.tp_len = PACKET_SKB_CB(skb)->origlen;
+                aux.tp_snaplen = skb->len;
+                aux.tp_mac = 0;
+                aux.tp_net = skb->nh.raw - skb->data;
+
+                put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
+        }
 
         /*
          *      Free or return the buffer as appropriate. Again this
@@ -1317,6 +1350,7 @@ static int
 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, int optlen)
 {
         struct sock *sk = sock->sk;
+        struct packet_sock *po = pkt_sk(sk);
         int ret;
 
         if (level != SOL_PACKET)
@@ -1369,6 +1403,18 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
                 return 0;
         }
 #endif
+        case PACKET_AUXDATA:
+        {
+                int val;
+
+                if (optlen < sizeof(val))
+                        return -EINVAL;
+                if (copy_from_user(&val, optval, sizeof(val)))
+                        return -EFAULT;
+
+                po->auxdata = !!val;
+                return 0;
+        }
         default:
                 return -ENOPROTOOPT;
         }
@@ -1378,8 +1424,11 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
                              char __user *optval, int __user *optlen)
 {
         int len;
+        int val;
         struct sock *sk = sock->sk;
         struct packet_sock *po = pkt_sk(sk);
+        void *data;
+        struct tpacket_stats st;
 
         if (level != SOL_PACKET)
                 return -ENOPROTOOPT;
@@ -1392,9 +1441,6 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
                 
         switch(optname) {
         case PACKET_STATISTICS:
-        {
-                struct tpacket_stats st;
-
                 if (len > sizeof(struct tpacket_stats))
                         len = sizeof(struct tpacket_stats);
                 spin_lock_bh(&sk->sk_receive_queue.lock);
@@ -1403,16 +1449,23 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
                 spin_unlock_bh(&sk->sk_receive_queue.lock);
                 st.tp_packets += st.tp_drops;
 
-                if (copy_to_user(optval, &st, len))
-                        return -EFAULT;
+                data = &st;
+                break;
+        case PACKET_AUXDATA:
+                if (len > sizeof(int))
+                        len = sizeof(int);
+                val = po->auxdata;
+
+                data = &val;
                 break;
-        }
         default:
                 return -ENOPROTOOPT;
         }
 
         if (put_user(len, optlen))
                 return -EFAULT;
+        if (copy_to_user(optval, data, len))
+                return -EFAULT;
         return 0;
 }