target/linux/generic/patches-2.6.34/240-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 @@ -47,6 +49,8 @@ struct sockaddr_ll {
  20  #define PACKET_TX_RING                 13
  21  #define PACKET_LOSS                    14
  22  #define PACKET_VNET_HDR                        15
  23 +#define PACKET_RECV_TYPE               16
  24 +
  25
  26  struct tpacket_stats {
  27         unsigned int    tp_packets;
  28 --- a/net/packet/af_packet.c
  29 +++ b/net/packet/af_packet.c
  30 @@ -202,6 +202,7 @@ struct packet_sock {
  31         unsigned int            tp_reserve;
  32         unsigned int            tp_loss:1;
  33         struct packet_type      prot_hook ____cacheline_aligned_in_smp;
  34 +       __u8                    pkt_type:3;
  35  };
  36
  37  struct packet_skb_cb {
  38 @@ -336,6 +337,7 @@ static int packet_rcv_spkt(struct sk_buf
  39  {
  40         struct sock *sk;
  41         struct sockaddr_pkt *spkt;
  42 +       struct packet_sock *po;
  43
  44         /*
  45          *      When we registered the protocol we saved the socket in the data
  46 @@ -343,6 +345,7 @@ static int packet_rcv_spkt(struct sk_buf
  47          */
  48
  49         sk = pt->af_packet_priv;
  50 +       po = pkt_sk(sk);
  51
  52         /*
  53          *      Yank back the headers [hope the device set this
  54 @@ -355,7 +358,7 @@ static int packet_rcv_spkt(struct sk_buf
  55          *      so that this procedure is noop.
  56          */
  57
  58 -       if (skb->pkt_type == PACKET_LOOPBACK)
  59 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  60                 goto out;
  61
  62         if (!net_eq(dev_net(dev), sock_net(sk)))
  63 @@ -531,12 +534,12 @@ static int packet_rcv(struct sk_buff *sk
  64         int skb_len = skb->len;
  65         unsigned int snaplen, res;
  66
  67 -       if (skb->pkt_type == PACKET_LOOPBACK)
  68 -               goto drop;
  69 -
  70         sk = pt->af_packet_priv;
  71         po = pkt_sk(sk);
  72
  73 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  74 +               goto drop;
  75 +
  76         if (!net_eq(dev_net(dev), sock_net(sk)))
  77                 goto drop;
  78
  79 @@ -651,12 +654,12 @@ static int tpacket_rcv(struct sk_buff *s
  80         struct timeval tv;
  81         struct timespec ts;
  82
  83 -       if (skb->pkt_type == PACKET_LOOPBACK)
  84 -               goto drop;
  85 -
  86         sk = pt->af_packet_priv;
  87         po = pkt_sk(sk);
  88
  89 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  90 +               goto drop;
  91 +
  92         if (!net_eq(dev_net(dev), sock_net(sk)))
  93                 goto drop;
  94
  95 @@ -1464,6 +1467,7 @@ static int packet_create(struct net *net
  96         spin_lock_init(&po->bind_lock);
  97         mutex_init(&po->pg_vec_lock);
  98         po->prot_hook.func = packet_rcv;
  99 +       po->pkt_type = PACKET_MASK_ANY & ~(1 << PACKET_LOOPBACK);
 100
 101         if (sock->type == SOCK_PACKET)
 102                 po->prot_hook.func = packet_rcv_spkt;
 103 @@ -1968,6 +1972,16 @@ packet_setsockopt(struct socket *sock, i
 104                 po->has_vnet_hdr = !!val;
 105                 return 0;
 106         }
 107 +        case PACKET_RECV_TYPE:
 108 +        {
 109 +                unsigned int val;
 110 +                if (optlen != sizeof(val))
 111 +                        return -EINVAL;
 112 +                if (copy_from_user(&val, optval, sizeof(val)))
 113 +                        return -EFAULT;
 114 +                po->pkt_type = val & ~PACKET_LOOPBACK;
 115 +                return 0;
 116 +        }
 117         default:
 118                 return -ENOPROTOOPT;
 119         }
 120 @@ -2025,6 +2039,13 @@ static int packet_getsockopt(struct sock
 121
 122                 data = &val;
 123                 break;
 124 +       case PACKET_RECV_TYPE:
 125 +               if (len > sizeof(unsigned int))
 126 +                       len = sizeof(unsigned int);
 127 +               val = po->pkt_type;
 128 +
 129 +               data = &val;
 130 +               break;
 131         case PACKET_VERSION:
 132                 if (len > sizeof(int))
 133                         len = sizeof(int);