target/linux/generic-2.6/patches-2.6.33/240-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 @@ -46,6 +48,7 @@ struct sockaddr_ll {
  20  #define PACKET_RESERVE                 12
  21  #define PACKET_TX_RING                 13
  22  #define PACKET_LOSS                    14
  23 +#define PACKET_RECV_TYPE               15
  24
  25  struct tpacket_stats {
  26         unsigned int    tp_packets;
  27 --- a/net/packet/af_packet.c
  28 +++ b/net/packet/af_packet.c
  29 @@ -343,6 +343,7 @@ static int packet_rcv_spkt(struct sk_buf
  30  {
  31         struct sock *sk;
  32         struct sockaddr_pkt *spkt;
  33 +       struct packet_sock *po;
  34
  35         /*
  36          *      When we registered the protocol we saved the socket in the data
  37 @@ -350,6 +351,7 @@ static int packet_rcv_spkt(struct sk_buf
  38          */
  39
  40         sk = pt->af_packet_priv;
  41 +       po = pkt_sk(sk);
  42
  43         /*
  44          *      Yank back the headers [hope the device set this
  45 @@ -362,7 +364,7 @@ static int packet_rcv_spkt(struct sk_buf
  46          *      so that this procedure is noop.
  47          */
  48
  49 -       if (skb->pkt_type == PACKET_LOOPBACK)
  50 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  51                 goto out;
  52
  53         if (!net_eq(dev_net(dev), sock_net(sk)))
  54 @@ -538,12 +540,12 @@ static int packet_rcv(struct sk_buff *sk
  55         int skb_len = skb->len;
  56         unsigned int snaplen, res;
  57
  58 -       if (skb->pkt_type == PACKET_LOOPBACK)
  59 -               goto drop;
  60 -
  61         sk = pt->af_packet_priv;
  62         po = pkt_sk(sk);
  63
  64 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  65 +               goto drop;
  66 +
  67         if (!net_eq(dev_net(dev), sock_net(sk)))
  68                 goto drop;
  69
  70 @@ -659,12 +661,12 @@ static int tpacket_rcv(struct sk_buff *s
  71         struct timeval tv;
  72         struct timespec ts;
  73
  74 -       if (skb->pkt_type == PACKET_LOOPBACK)
  75 -               goto drop;
  76 -
  77         sk = pt->af_packet_priv;
  78         po = pkt_sk(sk);
  79
  80 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  81 +               goto drop;
  82 +
  83         if (!net_eq(dev_net(dev), sock_net(sk)))
  84                 goto drop;
  85
  86 @@ -1386,6 +1388,7 @@ static int packet_create(struct net *net
  87         spin_lock_init(&po->bind_lock);
  88         mutex_init(&po->pg_vec_lock);
  89         po->prot_hook.func = packet_rcv;
  90 +       po->pkt_type = PACKET_MASK_ANY & ~(1 << PACKET_LOOPBACK);
  91
  92         if (sock->type == SOCK_PACKET)
  93                 po->prot_hook.func = packet_rcv_spkt;
  94 @@ -1731,6 +1734,16 @@ packet_setsockopt(struct socket *sock, i
  95                         ret = packet_mc_drop(sk, &mreq);
  96                 return ret;
  97         }
  98 +       case PACKET_RECV_TYPE:
  99 +       {
 100 +               unsigned int val;
 101 +               if (optlen != sizeof(val))
 102 +                       return -EINVAL;
 103 +               if (copy_from_user(&val, optval, sizeof(val)))
 104 +                       return -EFAULT;
 105 +               po->pkt_type = val & ~PACKET_LOOPBACK;
 106 +               return 0;
 107 +       }
 108
 109  #ifdef CONFIG_PACKET_MMAP
 110         case PACKET_RX_RING:
 111 @@ -1876,6 +1889,13 @@ static int packet_getsockopt(struct sock
 112
 113                 data = &val;
 114                 break;
 115 +       case PACKET_RECV_TYPE:
 116 +               if (len > sizeof(unsigned int))
 117 +                       len = sizeof(unsigned int);
 118 +               val = po->pkt_type;
 119 +
 120 +               data = &val;
 121 +               break;
 122  #ifdef CONFIG_PACKET_MMAP
 123         case PACKET_VERSION:
 124                 if (len > sizeof(int))