| 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/uapi/linux/if_packet.h |
| 9 | +++ b/include/uapi/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 | @@ -50,6 +52,7 @@ struct sockaddr_ll { |
| 20 | #define PACKET_TX_TIMESTAMP 16 |
| 21 | #define PACKET_TIMESTAMP 17 |
| 22 | #define PACKET_FANOUT 18 |
| 23 | +#define PACKET_RECV_TYPE 19 |
| 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 | @@ -1273,6 +1273,7 @@ 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 | @@ -1280,6 +1281,7 @@ 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 | @@ -1292,7 +1294,7 @@ 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 | @@ -1498,12 +1500,12 @@ 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 | @@ -1622,12 +1624,12 @@ static int tpacket_rcv(struct sk_buff *s |
| 71 | struct timespec ts; |
| 72 | struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); |
| 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 | @@ -2511,6 +2513,7 @@ 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 | @@ -3111,6 +3114,16 @@ packet_setsockopt(struct socket *sock, i |
| 95 | |
| 96 | return fanout_add(sk, val & 0xffff, val >> 16); |
| 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 | default: |
| 109 | return -ENOPROTOOPT; |
| 110 | } |
| 111 | @@ -3165,6 +3178,13 @@ 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 | @@ -111,6 +111,7 @@ struct packet_sock { |
| 128 | unsigned int tp_loss:1; |
| 129 | unsigned int tp_tstamp; |
| 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) |
| 135 | |
