mirror of
https://github.com/joel16/android_kernel_sony_msm8994.git
synced 2024-11-27 06:01:12 +00:00
packet: Add fanout support.
Fanouts allow packet capturing to be demuxed to a set of AF_PACKET sockets. Two fanout policies are implemented: 1) Hashing based upon skb->rxhash 2) Pure round-robin An AF_PACKET socket must be fully bound before it tries to add itself to a fanout. All AF_PACKET sockets trying to join the same fanout must all have the same bind settings. Fanouts are identified (within a network namespace) by a 16-bit ID. The first socket to try to add itself to a fanout with a particular ID, creates that fanout. When the last socket leaves the fanout (which happens only when the socket is closed), that fanout is destroyed. Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
parent
ce06b03e60
commit
dc99f60069
@ -49,6 +49,10 @@ struct sockaddr_ll {
|
||||
#define PACKET_VNET_HDR 15
|
||||
#define PACKET_TX_TIMESTAMP 16
|
||||
#define PACKET_TIMESTAMP 17
|
||||
#define PACKET_FANOUT 18
|
||||
|
||||
#define PACKET_FANOUT_HASH 0
|
||||
#define PACKET_FANOUT_LB 1
|
||||
|
||||
struct tpacket_stats {
|
||||
unsigned int tp_packets;
|
||||
|
||||
@ -187,9 +187,11 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
|
||||
|
||||
static void packet_flush_mclist(struct sock *sk);
|
||||
|
||||
struct packet_fanout;
|
||||
struct packet_sock {
|
||||
/* struct sock has to be the first member of packet_sock */
|
||||
struct sock sk;
|
||||
struct packet_fanout *fanout;
|
||||
struct tpacket_stats stats;
|
||||
struct packet_ring_buffer rx_ring;
|
||||
struct packet_ring_buffer tx_ring;
|
||||
@ -212,6 +214,24 @@ struct packet_sock {
|
||||
struct packet_type prot_hook ____cacheline_aligned_in_smp;
|
||||
};
|
||||
|
||||
#define PACKET_FANOUT_MAX 256
|
||||
|
||||
struct packet_fanout {
|
||||
#ifdef CONFIG_NET_NS
|
||||
struct net *net;
|
||||
#endif
|
||||
unsigned int num_members;
|
||||
u16 id;
|
||||
u8 type;
|
||||
u8 pad;
|
||||
atomic_t rr_cur;
|
||||
struct list_head list;
|
||||
struct sock *arr[PACKET_FANOUT_MAX];
|
||||
spinlock_t lock;
|
||||
atomic_t sk_ref;
|
||||
struct packet_type prot_hook ____cacheline_aligned_in_smp;
|
||||
};
|
||||
|
||||
struct packet_skb_cb {
|
||||
unsigned int origlen;
|
||||
union {
|
||||
@ -227,6 +247,9 @@ static inline struct packet_sock *pkt_sk(struct sock *sk)
|
||||
return (struct packet_sock *)sk;
|
||||
}
|
||||
|
||||
static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
|
||||
static void __fanout_link(struct sock *sk, struct packet_sock *po);
|
||||
|
||||
/* register_prot_hook must be invoked with the po->bind_lock held,
|
||||
* or from a context in which asynchronous accesses to the packet
|
||||
* socket is not possible (packet_create()).
|
||||
@ -235,7 +258,10 @@ static void register_prot_hook(struct sock *sk)
|
||||
{
|
||||
struct packet_sock *po = pkt_sk(sk);
|
||||
if (!po->running) {
|
||||
dev_add_pack(&po->prot_hook);
|
||||
if (po->fanout)
|
||||
__fanout_link(sk, po);
|
||||
else
|
||||
dev_add_pack(&po->prot_hook);
|
||||
sock_hold(sk);
|
||||
po->running = 1;
|
||||
}
|
||||
@ -253,7 +279,10 @@ static void __unregister_prot_hook(struct sock *sk, bool sync)
|
||||
struct packet_sock *po = pkt_sk(sk);
|
||||
|
||||
po->running = 0;
|
||||
__dev_remove_pack(&po->prot_hook);
|
||||
if (po->fanout)
|
||||
__fanout_unlink(sk, po);
|
||||
else
|
||||
__dev_remove_pack(&po->prot_hook);
|
||||
__sock_put(sk);
|
||||
|
||||
if (sync) {
|
||||
@ -388,6 +417,201 @@ static void packet_sock_destruct(struct sock *sk)
|
||||
sk_refcnt_debug_dec(sk);
|
||||
}
|
||||
|
||||
static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
|
||||
{
|
||||
int x = atomic_read(&f->rr_cur) + 1;
|
||||
|
||||
if (x >= num)
|
||||
x = 0;
|
||||
|
||||
return x;
|
||||
}
|
||||
|
||||
static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
|
||||
{
|
||||
u32 idx, hash = skb->rxhash;
|
||||
|
||||
idx = ((u64)hash * num) >> 32;
|
||||
|
||||
return f->arr[idx];
|
||||
}
|
||||
|
||||
static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
|
||||
{
|
||||
int cur, old;
|
||||
|
||||
cur = atomic_read(&f->rr_cur);
|
||||
while ((old = atomic_cmpxchg(&f->rr_cur, cur,
|
||||
fanout_rr_next(f, num))) != cur)
|
||||
cur = old;
|
||||
return f->arr[cur];
|
||||
}
|
||||
|
||||
static int packet_rcv_fanout_hash(struct sk_buff *skb, struct net_device *dev,
|
||||
struct packet_type *pt, struct net_device *orig_dev)
|
||||
{
|
||||
struct packet_fanout *f = pt->af_packet_priv;
|
||||
unsigned int num = f->num_members;
|
||||
struct packet_sock *po;
|
||||
struct sock *sk;
|
||||
|
||||
if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
|
||||
!num) {
|
||||
kfree_skb(skb);
|
||||
return 0;
|
||||
}
|
||||
|
||||
skb_get_rxhash(skb);
|
||||
|
||||
sk = fanout_demux_hash(f, skb, num);
|
||||
po = pkt_sk(sk);
|
||||
|
||||
return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
|
||||
}
|
||||
|
||||
static int packet_rcv_fanout_lb(struct sk_buff *skb, struct net_device *dev,
|
||||
struct packet_type *pt, struct net_device *orig_dev)
|
||||
{
|
||||
struct packet_fanout *f = pt->af_packet_priv;
|
||||
unsigned int num = f->num_members;
|
||||
struct packet_sock *po;
|
||||
struct sock *sk;
|
||||
|
||||
if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
|
||||
!num) {
|
||||
kfree_skb(skb);
|
||||
return 0;
|
||||
}
|
||||
|
||||
sk = fanout_demux_lb(f, skb, num);
|
||||
po = pkt_sk(sk);
|
||||
|
||||
return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
|
||||
}
|
||||
|
||||
static DEFINE_MUTEX(fanout_mutex);
|
||||
static LIST_HEAD(fanout_list);
|
||||
|
||||
static void __fanout_link(struct sock *sk, struct packet_sock *po)
|
||||
{
|
||||
struct packet_fanout *f = po->fanout;
|
||||
|
||||
spin_lock(&f->lock);
|
||||
f->arr[f->num_members] = sk;
|
||||
smp_wmb();
|
||||
f->num_members++;
|
||||
spin_unlock(&f->lock);
|
||||
}
|
||||
|
||||
static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
|
||||
{
|
||||
struct packet_fanout *f = po->fanout;
|
||||
int i;
|
||||
|
||||
spin_lock(&f->lock);
|
||||
for (i = 0; i < f->num_members; i++) {
|
||||
if (f->arr[i] == sk)
|
||||
break;
|
||||
}
|
||||
BUG_ON(i >= f->num_members);
|
||||
f->arr[i] = f->arr[f->num_members - 1];
|
||||
f->num_members--;
|
||||
spin_unlock(&f->lock);
|
||||
}
|
||||
|
||||
static int fanout_add(struct sock *sk, u16 id, u8 type)
|
||||
{
|
||||
struct packet_sock *po = pkt_sk(sk);
|
||||
struct packet_fanout *f, *match;
|
||||
int err;
|
||||
|
||||
switch (type) {
|
||||
case PACKET_FANOUT_HASH:
|
||||
case PACKET_FANOUT_LB:
|
||||
break;
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (!po->running)
|
||||
return -EINVAL;
|
||||
|
||||
if (po->fanout)
|
||||
return -EALREADY;
|
||||
|
||||
mutex_lock(&fanout_mutex);
|
||||
match = NULL;
|
||||
list_for_each_entry(f, &fanout_list, list) {
|
||||
if (f->id == id &&
|
||||
read_pnet(&f->net) == sock_net(sk)) {
|
||||
match = f;
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (!match) {
|
||||
match = kzalloc(sizeof(*match), GFP_KERNEL);
|
||||
if (match) {
|
||||
write_pnet(&match->net, sock_net(sk));
|
||||
match->id = id;
|
||||
match->type = type;
|
||||
atomic_set(&match->rr_cur, 0);
|
||||
INIT_LIST_HEAD(&match->list);
|
||||
spin_lock_init(&match->lock);
|
||||
atomic_set(&match->sk_ref, 0);
|
||||
match->prot_hook.type = po->prot_hook.type;
|
||||
match->prot_hook.dev = po->prot_hook.dev;
|
||||
switch (type) {
|
||||
case PACKET_FANOUT_HASH:
|
||||
match->prot_hook.func = packet_rcv_fanout_hash;
|
||||
break;
|
||||
case PACKET_FANOUT_LB:
|
||||
match->prot_hook.func = packet_rcv_fanout_lb;
|
||||
break;
|
||||
}
|
||||
match->prot_hook.af_packet_priv = match;
|
||||
dev_add_pack(&match->prot_hook);
|
||||
list_add(&match->list, &fanout_list);
|
||||
}
|
||||
}
|
||||
err = -ENOMEM;
|
||||
if (match) {
|
||||
err = -EINVAL;
|
||||
if (match->type == type &&
|
||||
match->prot_hook.type == po->prot_hook.type &&
|
||||
match->prot_hook.dev == po->prot_hook.dev) {
|
||||
err = -ENOSPC;
|
||||
if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
|
||||
__dev_remove_pack(&po->prot_hook);
|
||||
po->fanout = match;
|
||||
atomic_inc(&match->sk_ref);
|
||||
__fanout_link(sk, po);
|
||||
err = 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
mutex_unlock(&fanout_mutex);
|
||||
return err;
|
||||
}
|
||||
|
||||
static void fanout_release(struct sock *sk)
|
||||
{
|
||||
struct packet_sock *po = pkt_sk(sk);
|
||||
struct packet_fanout *f;
|
||||
|
||||
f = po->fanout;
|
||||
if (!f)
|
||||
return;
|
||||
|
||||
po->fanout = NULL;
|
||||
|
||||
mutex_lock(&fanout_mutex);
|
||||
if (atomic_dec_and_test(&f->sk_ref)) {
|
||||
list_del(&f->list);
|
||||
dev_remove_pack(&f->prot_hook);
|
||||
kfree(f);
|
||||
}
|
||||
mutex_unlock(&fanout_mutex);
|
||||
}
|
||||
|
||||
static const struct proto_ops packet_ops;
|
||||
|
||||
@ -1398,6 +1622,8 @@ static int packet_release(struct socket *sock)
|
||||
if (po->tx_ring.pg_vec)
|
||||
packet_set_ring(sk, &req, 1, 1);
|
||||
|
||||
fanout_release(sk);
|
||||
|
||||
synchronize_net();
|
||||
/*
|
||||
* Now the socket is dead. No more input will appear.
|
||||
@ -1421,9 +1647,9 @@ static int packet_release(struct socket *sock)
|
||||
static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
|
||||
{
|
||||
struct packet_sock *po = pkt_sk(sk);
|
||||
/*
|
||||
* Detach an existing hook if present.
|
||||
*/
|
||||
|
||||
if (po->fanout)
|
||||
return -EINVAL;
|
||||
|
||||
lock_sock(sk);
|
||||
|
||||
@ -2133,6 +2359,17 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
|
||||
po->tp_tstamp = val;
|
||||
return 0;
|
||||
}
|
||||
case PACKET_FANOUT:
|
||||
{
|
||||
int val;
|
||||
|
||||
if (optlen != sizeof(val))
|
||||
return -EINVAL;
|
||||
if (copy_from_user(&val, optval, sizeof(val)))
|
||||
return -EFAULT;
|
||||
|
||||
return fanout_add(sk, val & 0xffff, val >> 16);
|
||||
}
|
||||
default:
|
||||
return -ENOPROTOOPT;
|
||||
}
|
||||
@ -2231,6 +2468,15 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
|
||||
val = po->tp_tstamp;
|
||||
data = &val;
|
||||
break;
|
||||
case PACKET_FANOUT:
|
||||
if (len > sizeof(int))
|
||||
len = sizeof(int);
|
||||
val = (po->fanout ?
|
||||
((u32)po->fanout->id |
|
||||
((u32)po->fanout->type << 16)) :
|
||||
0);
|
||||
data = &val;
|
||||
break;
|
||||
default:
|
||||
return -ENOPROTOOPT;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user