target/linux/generic/patches-3.3/630-packet_socket_type.patch

   1 This patch allows the user to specify desired packet types (outgoing,
   2 broadcast, unicast, etc.) on packet sockets via setsockopt.
   3 This can reduce the load in situations where only a limited number
   4 of packet types are necessary
   5
   6 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
   7
   8 --- a/include/linux/if_packet.h
   9 +++ b/include/linux/if_packet.h
  10 @@ -29,6 +29,8 @@ struct sockaddr_ll {
  11  /* These ones are invisible by user level */
  12  #define PACKET_LOOPBACK                5               /* MC/BRD frame looped back */
  13  #define PACKET_FASTROUTE       6               /* Fastrouted frame     */
  14 +#define PACKET_MASK_ANY                0xffffffff      /* mask for packet type bits */
  15 +
  16
  17  /* Packet socket options */
  18
  19 @@ -50,6 +52,7 @@ struct sockaddr_ll {
  20  #define PACKET_TX_TIMESTAMP            16
  21  #define PACKET_TIMESTAMP               17
  22  #define PACKET_FANOUT                  18
  23 +#define PACKET_RECV_TYPE               19
  24
  25  #define PACKET_FANOUT_HASH             0
  26  #define PACKET_FANOUT_LB               1
  27 --- a/net/packet/af_packet.c
  28 +++ b/net/packet/af_packet.c
  29 @@ -296,6 +296,7 @@ struct packet_sock {
  30         unsigned int            tp_loss:1;
  31         unsigned int            tp_tstamp;
  32         struct packet_type      prot_hook ____cacheline_aligned_in_smp;
  33 +       unsigned int            pkt_type;
  34  };
  35
  36  #define PACKET_FANOUT_MAX      256
  37 @@ -1383,6 +1384,7 @@ static int packet_rcv_spkt(struct sk_buf
  38  {
  39         struct sock *sk;
  40         struct sockaddr_pkt *spkt;
  41 +       struct packet_sock *po;
  42
  43         /*
  44          *      When we registered the protocol we saved the socket in the data
  45 @@ -1390,6 +1392,7 @@ static int packet_rcv_spkt(struct sk_buf
  46          */
  47
  48         sk = pt->af_packet_priv;
  49 +       po = pkt_sk(sk);
  50
  51         /*
  52          *      Yank back the headers [hope the device set this
  53 @@ -1402,7 +1405,7 @@ static int packet_rcv_spkt(struct sk_buf
  54          *      so that this procedure is noop.
  55          */
  56
  57 -       if (skb->pkt_type == PACKET_LOOPBACK)
  58 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  59                 goto out;
  60
  61         if (!net_eq(dev_net(dev), sock_net(sk)))
  62 @@ -1596,12 +1599,12 @@ static int packet_rcv(struct sk_buff *sk
  63         int skb_len = skb->len;
  64         unsigned int snaplen, res;
  65
  66 -       if (skb->pkt_type == PACKET_LOOPBACK)
  67 -               goto drop;
  68 -
  69         sk = pt->af_packet_priv;
  70         po = pkt_sk(sk);
  71
  72 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  73 +               goto drop;
  74 +
  75         if (!net_eq(dev_net(dev), sock_net(sk)))
  76                 goto drop;
  77
  78 @@ -1720,12 +1723,12 @@ static int tpacket_rcv(struct sk_buff *s
  79         struct timespec ts;
  80         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
  81
  82 -       if (skb->pkt_type == PACKET_LOOPBACK)
  83 -               goto drop;
  84 -
  85         sk = pt->af_packet_priv;
  86         po = pkt_sk(sk);
  87
  88 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  89 +               goto drop;
  90 +
  91         if (!net_eq(dev_net(dev), sock_net(sk)))
  92                 goto drop;
  93
  94 @@ -2595,6 +2598,7 @@ static int packet_create(struct net *net
  95         spin_lock_init(&po->bind_lock);
  96         mutex_init(&po->pg_vec_lock);
  97         po->prot_hook.func = packet_rcv;
  98 +       po->pkt_type = PACKET_MASK_ANY & ~(1 << PACKET_LOOPBACK);
  99
 100         if (sock->type == SOCK_PACKET)
 101                 po->prot_hook.func = packet_rcv_spkt;
 102 @@ -3192,6 +3196,16 @@ packet_setsockopt(struct socket *sock, i
 103
 104                 return fanout_add(sk, val & 0xffff, val >> 16);
 105         }
 106 +        case PACKET_RECV_TYPE:
 107 +        {
 108 +                unsigned int val;
 109 +                if (optlen != sizeof(val))
 110 +                        return -EINVAL;
 111 +                if (copy_from_user(&val, optval, sizeof(val)))
 112 +                        return -EFAULT;
 113 +                po->pkt_type = val & ~BIT(PACKET_LOOPBACK);
 114 +                return 0;
 115 +        }
 116         default:
 117                 return -ENOPROTOOPT;
 118         }
 119 @@ -3262,6 +3276,13 @@ static int packet_getsockopt(struct sock
 120
 121                 data = &val;
 122                 break;
 123 +       case PACKET_RECV_TYPE:
 124 +               if (len > sizeof(unsigned int))
 125 +                       len = sizeof(unsigned int);
 126 +               val = po->pkt_type;
 127 +
 128 +               data = &val;
 129 +               break;
 130         case PACKET_VERSION:
 131                 if (len > sizeof(int))
 132                         len = sizeof(int);