target/linux/generic-2.6/patches-2.6.29/240-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 @@ -31,6 +31,8 @@ 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_ANY             0xffffffff
  15 +
  16
  17  /* Packet socket options */
  18
  19 @@ -46,6 +48,7 @@ struct sockaddr_ll
  20  #define PACKET_VERSION                 10
  21  #define PACKET_HDRLEN                  11
  22  #define PACKET_RESERVE                 12
  23 +#define PACKET_RECV_TYPE               13
  24
  25  struct tpacket_stats
  26  {
  27 --- a/net/packet/af_packet.c
  28 +++ b/net/packet/af_packet.c
  29 @@ -192,6 +192,7 @@ struct packet_sock {
  30         unsigned int            tp_hdrlen;
  31         unsigned int            tp_reserve;
  32  #endif
  33 +       int                     pkt_type;
  34  };
  35
  36  struct packet_skb_cb {
  37 @@ -282,6 +283,7 @@ 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 @@ -289,6 +291,7 @@ 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 @@ -301,7 +304,7 @@ 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 (dev_net(dev) != sock_net(sk))
  62 @@ -486,12 +489,12 @@ 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 (dev_net(dev) != sock_net(sk))
  76                 goto drop;
  77
  78 @@ -608,12 +611,12 @@ static int tpacket_rcv(struct sk_buff *s
  79         struct timeval tv;
  80         struct timespec ts;
  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 (dev_net(dev) != sock_net(sk))
  92                 goto drop;
  93
  94 @@ -1072,6 +1075,7 @@ 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_ANY & ~PACKET_LOOPBACK;
  99
 100         if (sock->type == SOCK_PACKET)
 101                 po->prot_hook.func = packet_rcv_spkt;
 102 @@ -1411,6 +1415,16 @@ packet_setsockopt(struct socket *sock, i
 103                         ret = packet_mc_drop(sk, &mreq);
 104                 return ret;
 105         }
 106 +       case PACKET_RECV_TYPE:
 107 +       {
 108 +               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 & ~PACKET_LOOPBACK;
 114 +               return 0;
 115 +       }
 116
 117  #ifdef CONFIG_PACKET_MMAP
 118         case PACKET_RX_RING:
 119 @@ -1542,6 +1556,13 @@ static int packet_getsockopt(struct sock
 120
 121                 data = &val;
 122                 break;
 123 +       case PACKET_RECV_TYPE:
 124 +               if (len > sizeof(int))
 125 +                       len = sizeof(int);
 126 +               val = po->pkt_type;
 127 +
 128 +               data = &val;
 129 +               break;
 130  #ifdef CONFIG_PACKET_MMAP
 131         case PACKET_VERSION:
 132                 if (len > sizeof(int))