target/linux/generic/pending-4.4/630-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@nbd.name>
   7
   8 --- a/include/uapi/linux/if_packet.h
   9 +++ b/include/uapi/linux/if_packet.h
  10 @@ -31,6 +31,8 @@ struct sockaddr_ll {
  11  #define PACKET_KERNEL          7               /* To kernel space      */
  12  /* Unused, PACKET_FASTROUTE and PACKET_LOOPBACK are invisible to user space */
  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 @@ -56,6 +58,7 @@ struct sockaddr_ll {
  20  #define PACKET_QDISC_BYPASS            20
  21  #define PACKET_ROLLOVER_STATS          21
  22  #define PACKET_FANOUT_DATA             22
  23 +#define PACKET_RECV_TYPE               23
  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 @@ -1776,6 +1776,7 @@ 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 @@ -1783,6 +1784,7 @@ 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 @@ -1795,7 +1797,7 @@ 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 @@ -1998,12 +2000,12 @@ 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 @@ -2123,12 +2125,12 @@ static int tpacket_rcv(struct sk_buff *s
  71         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
  72         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
  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 @@ -3115,6 +3117,7 @@ static int packet_create(struct net *net
  87         mutex_init(&po->pg_vec_lock);
  88         po->rollover = NULL;
  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 @@ -3744,6 +3747,16 @@ packet_setsockopt(struct socket *sock, i
  95                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
  96                 return 0;
  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 & ~BIT(PACKET_LOOPBACK);
 106 +                return 0;
 107 +        }
 108         default:
 109                 return -ENOPROTOOPT;
 110         }
 111 @@ -3796,6 +3809,13 @@ static int packet_getsockopt(struct sock
 112         case PACKET_VNET_HDR:
 113                 val = po->has_vnet_hdr;
 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         case PACKET_VERSION:
 123                 val = po->tp_version;
 124                 break;
 125 --- a/net/packet/internal.h
 126 +++ b/net/packet/internal.h
 127 @@ -129,6 +129,7 @@ struct packet_sock {
 128         struct net_device __rcu *cached_dev;
 129         int                     (*xmit)(struct sk_buff *skb);
 130         struct packet_type      prot_hook ____cacheline_aligned_in_smp;
 131 +       unsigned int            pkt_type;
 132  };
 133
 134  static struct packet_sock *pkt_sk(struct sock *sk)