Gur Stavi wrote:
PACKET socket can retain its fanout membership through link down and up and leave a fanout while closed regardless of link state. However, socket was forbidden from joining a fanout while it was not RUNNING.
This patch allows PACKET socket to join fanout while not RUNNING.
The previous test for RUNNING also implicitly tested that the socket is bound to a device. An explicit test of ifindex was added instead.
Signed-off-by: Gur Stavi gur.stavi@huawei.com
net/packet/af_packet.c | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index f8942062f776..8137c33ab0fd 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1843,26 +1843,29 @@ static int fanout_add(struct sock *sk, struct
fanout_args *args)
match->prot_hook.ignore_outgoing = type_flags &PACKET_FANOUT_FLAG_IGNORE_OUTGOING;
list_add(&match->list, &fanout_list);}
err = -EINVAL;
spin_lock(&po->bind_lock);
if (packet_sock_flag(po, PACKET_SOCK_RUNNING) &&
match->type == type &&match->prot_hook.type == po->prot_hook.type &&match->prot_hook.dev == po->prot_hook.dev) {
- if (po->ifindex == -1 || po->num == 0) {
This patch is more complex than it needs to be.
No need to block the case of ETH_P_NONE or not bound to a socket.
ETH_P_NONE was blocked before as well. packet_do_bind will not switch socket to RUNNING when proto is 0.
if (proto == 0 || !need_rehook) goto out_unlock;
Same for packet_create.
So the old condition could only pass the RUNNING condition if proto was non-zero. The new condition is exactly equivalent except for allowing IFF_UP to be cleared in the bound device.
Yes, the same result could be achieved with a FEW less line changes but I think that the new logic is more readable where every clause explains itself with a comment instead of constructing one large if statement. And since the solution does add another nested if for the RUNNING the extra indentation started to look ugly.
I would have discussed that in v2, but you already respun.
/* Socket can not receive packets */err = -ENXIO;- } else if (match->type != type ||
match->prot_hook.type != po->prot_hook.type ||match->prot_hook.dev != po->prot_hook.dev) {/* Joining an existing group, properties must be identical */err = -EINVAL;- } else if (refcount_read(&match->sk_ref) >= match->max_num_members)
{
err = -ENOSPC;
if (refcount_read(&match->sk_ref) < match->max_num_members) {
- } else {
/* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */WRITE_ONCE(po->fanout, match);po->rollover = rollover;rollover = NULL;refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) +1);
if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { __dev_remove_pack(&po->prot_hook);
/* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */WRITE_ONCE(po->fanout, match);po->rollover = rollover;rollover = NULL;refcount_set(&match->sk_ref, refcount_read(&match-sk_ref) + 1); __fanout_link(sk, po);
err = 0;
err = 0;@@ -3452,8 +3455,12 @@ static int packet_create(struct net *net, struct
socket *sock, int protocol,
po->prot_hook.af_packet_net = sock_net(sk);
if (proto) {
/* Implicitly bind socket to "any interface" */po->ifindex = 0;po->prot_hook.type = proto; __register_prot_hook(sk);
} else {
po->ifindex = -1;}
mutex_lock(&net->packet.sklist_lock);
-- 2.45.2