target/linux/generic/pending-4.9/630-packet_socket_type.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Subject: net: add an optimization for dealing with raw sockets
   3
   4 lede-commit: 4898039703d7315f0f3431c860123338ec3be0f6
   5 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   6 ---
   7  include/uapi/linux/if_packet.h |  3 +++
   8  net/packet/af_packet.c         | 34 +++++++++++++++++++++++++++-------
   9  net/packet/internal.h          |  1 +
  10  3 files changed, 31 insertions(+), 7 deletions(-)
  11
  12 --- a/include/uapi/linux/if_packet.h
  13 +++ b/include/uapi/linux/if_packet.h
  14 @@ -31,6 +31,8 @@ struct sockaddr_ll {
  15  #define PACKET_KERNEL          7               /* To kernel space      */
  16  /* Unused, PACKET_FASTROUTE and PACKET_LOOPBACK are invisible to user space */
  17  #define PACKET_FASTROUTE       6               /* Fastrouted frame     */
  18 +#define PACKET_MASK_ANY                0xffffffff      /* mask for packet type bits */
  19 +
  20
  21  /* Packet socket options */
  22
  23 @@ -56,6 +58,7 @@ struct sockaddr_ll {
  24  #define PACKET_QDISC_BYPASS            20
  25  #define PACKET_ROLLOVER_STATS          21
  26  #define PACKET_FANOUT_DATA             22
  27 +#define PACKET_RECV_TYPE               23
  28
  29  #define PACKET_FANOUT_HASH             0
  30  #define PACKET_FANOUT_LB               1
  31 --- a/net/packet/af_packet.c
  32 +++ b/net/packet/af_packet.c
  33 @@ -1773,6 +1773,7 @@ static int packet_rcv_spkt(struct sk_buf
  34  {
  35         struct sock *sk;
  36         struct sockaddr_pkt *spkt;
  37 +       struct packet_sock *po;
  38
  39         /*
  40          *      When we registered the protocol we saved the socket in the data
  41 @@ -1780,6 +1781,7 @@ static int packet_rcv_spkt(struct sk_buf
  42          */
  43
  44         sk = pt->af_packet_priv;
  45 +       po = pkt_sk(sk);
  46
  47         /*
  48          *      Yank back the headers [hope the device set this
  49 @@ -1792,7 +1794,7 @@ static int packet_rcv_spkt(struct sk_buf
  50          *      so that this procedure is noop.
  51          */
  52
  53 -       if (skb->pkt_type == PACKET_LOOPBACK)
  54 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  55                 goto out;
  56
  57         if (!net_eq(dev_net(dev), sock_net(sk)))
  58 @@ -2030,12 +2032,12 @@ static int packet_rcv(struct sk_buff *sk
  59         unsigned int snaplen, res;
  60         bool is_drop_n_account = false;
  61
  62 -       if (skb->pkt_type == PACKET_LOOPBACK)
  63 -               goto drop;
  64 -
  65         sk = pt->af_packet_priv;
  66         po = pkt_sk(sk);
  67
  68 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  69 +               goto drop;
  70 +
  71         if (!net_eq(dev_net(dev), sock_net(sk)))
  72                 goto drop;
  73
  74 @@ -2161,12 +2163,12 @@ static int tpacket_rcv(struct sk_buff *s
  75         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
  76         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
  77
  78 -       if (skb->pkt_type == PACKET_LOOPBACK)
  79 -               goto drop;
  80 -
  81         sk = pt->af_packet_priv;
  82         po = pkt_sk(sk);
  83
  84 +       if (!(po->pkt_type & (1 << skb->pkt_type)))
  85 +               goto drop;
  86 +
  87         if (!net_eq(dev_net(dev), sock_net(sk)))
  88                 goto drop;
  89
  90 @@ -3251,6 +3253,7 @@ static int packet_create(struct net *net
  91         mutex_init(&po->pg_vec_lock);
  92         po->rollover = NULL;
  93         po->prot_hook.func = packet_rcv;
  94 +       po->pkt_type = PACKET_MASK_ANY & ~(1 << PACKET_LOOPBACK);
  95
  96         if (sock->type == SOCK_PACKET)
  97                 po->prot_hook.func = packet_rcv_spkt;
  98 @@ -3837,6 +3840,16 @@ packet_setsockopt(struct socket *sock, i
  99                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
 100                 return 0;
 101         }
 102 +        case PACKET_RECV_TYPE:
 103 +        {
 104 +                unsigned int val;
 105 +                if (optlen != sizeof(val))
 106 +                        return -EINVAL;
 107 +                if (copy_from_user(&val, optval, sizeof(val)))
 108 +                        return -EFAULT;
 109 +                po->pkt_type = val & ~BIT(PACKET_LOOPBACK);
 110 +                return 0;
 111 +        }
 112         default:
 113                 return -ENOPROTOOPT;
 114         }
 115 @@ -3889,6 +3902,13 @@ static int packet_getsockopt(struct sock
 116         case PACKET_VNET_HDR:
 117                 val = po->has_vnet_hdr;
 118                 break;
 119 +       case PACKET_RECV_TYPE:
 120 +               if (len > sizeof(unsigned int))
 121 +                       len = sizeof(unsigned int);
 122 +               val = po->pkt_type;
 123 +
 124 +               data = &val;
 125 +               break;
 126         case PACKET_VERSION:
 127                 val = po->tp_version;
 128                 break;
 129 --- a/net/packet/internal.h
 130 +++ b/net/packet/internal.h
 131 @@ -128,6 +128,7 @@ struct packet_sock {
 132         struct net_device __rcu *cached_dev;
 133         int                     (*xmit)(struct sk_buff *skb);
 134         struct packet_type      prot_hook ____cacheline_aligned_in_smp;
 135 +       unsigned int            pkt_type;
 136  };
 137
 138  static struct packet_sock *pkt_sk(struct sock *sk)