+ ABSTRACT
--------------------------------------------------------------------------------
-This file documents the CONFIG_PACKET_MMAP option available with the PACKET
+This file documents the mmap() facility available with the PACKET
socket interface on 2.4 and 2.6 kernels. This type of sockets is used for
capture network traffic with utilities like tcpdump or any other that needs
raw access to network interface.
supported by devices of your network.
--------------------------------------------------------------------------------
-+ How to use CONFIG_PACKET_MMAP to improve capture process
++ How to use mmap() to improve capture process
--------------------------------------------------------------------------------
From the user standpoint, you should use the higher level libpcap library, which
support.
--------------------------------------------------------------------------------
-+ How to use CONFIG_PACKET_MMAP directly to improve capture process
++ How to use mmap() directly to improve capture process
--------------------------------------------------------------------------------
From the system calls stand point, the use of PACKET_MMAP involves
the use of this buffer.
--------------------------------------------------------------------------------
-+ How to use CONFIG_PACKET_MMAP directly to improve transmission process
++ How to use mmap() directly to improve transmission process
--------------------------------------------------------------------------------
Transmission process is similar to capture as shown below.
unsigned char mr_address[MAX_ADDR_LEN];
};
-#ifdef CONFIG_PACKET_MMAP
static int packet_set_ring(struct sock *sk, struct tpacket_req *req,
int closing, int tx_ring);
struct packet_sock;
static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
-#endif
static void packet_flush_mclist(struct sock *sk);
/* struct sock has to be the first member of packet_sock */
struct sock sk;
struct tpacket_stats stats;
-#ifdef CONFIG_PACKET_MMAP
struct packet_ring_buffer rx_ring;
struct packet_ring_buffer tx_ring;
int copy_thresh;
-#endif
spinlock_t bind_lock;
struct mutex pg_vec_lock;
unsigned int running:1, /* prot_hook is attached*/
int ifindex; /* bound device */
__be16 num;
struct packet_mclist *mclist;
-#ifdef CONFIG_PACKET_MMAP
atomic_t mapped;
enum tpacket_versions tp_version;
unsigned int tp_hdrlen;
unsigned int tp_reserve;
unsigned int tp_loss:1;
-#endif
struct packet_type prot_hook ____cacheline_aligned_in_smp;
};
#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb))
-#ifdef CONFIG_PACKET_MMAP
-
static void __packet_set_status(struct packet_sock *po, void *frame, int status)
{
union {
buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
}
-#endif
-
static inline struct packet_sock *pkt_sk(struct sock *sk)
{
return (struct packet_sock *)sk;
return 0;
}
-#ifdef CONFIG_PACKET_MMAP
static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
mutex_unlock(&po->pg_vec_lock);
return err;
}
-#endif
static inline struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
size_t reserve, size_t len,
static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len)
{
-#ifdef CONFIG_PACKET_MMAP
struct sock *sk = sock->sk;
struct packet_sock *po = pkt_sk(sk);
if (po->tx_ring.pg_vec)
return tpacket_snd(po, msg);
else
-#endif
return packet_snd(sock, msg, len);
}
struct sock *sk = sock->sk;
struct packet_sock *po;
struct net *net;
-#ifdef CONFIG_PACKET_MMAP
struct tpacket_req req;
-#endif
if (!sk)
return 0;
packet_flush_mclist(sk);
-#ifdef CONFIG_PACKET_MMAP
memset(&req, 0, sizeof(req));
if (po->rx_ring.pg_vec)
if (po->tx_ring.pg_vec)
packet_set_ring(sk, &req, 1, 1);
-#endif
/*
* Now the socket is dead. No more input will appear.
return ret;
}
-#ifdef CONFIG_PACKET_MMAP
case PACKET_RX_RING:
case PACKET_TX_RING:
{
po->tp_loss = !!val;
return 0;
}
-#endif
case PACKET_AUXDATA:
{
int val;
data = &val;
break;
-#ifdef CONFIG_PACKET_MMAP
case PACKET_VERSION:
if (len > sizeof(int))
len = sizeof(int);
val = po->tp_loss;
data = &val;
break;
-#endif
default:
return -ENOPROTOOPT;
}
return 0;
}
-#ifndef CONFIG_PACKET_MMAP
-#define packet_mmap sock_no_mmap
-#define packet_poll datagram_poll
-#else
-
static unsigned int packet_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
mutex_unlock(&po->pg_vec_lock);
return err;
}
-#endif
-
static const struct proto_ops packet_ops_spkt = {
.family = PF_PACKET,