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authorDavid S. Miller <davem@davemloft.net>2012-12-01 20:45:24 -0500
committerDavid S. Miller <davem@davemloft.net>2012-12-01 20:45:24 -0500
commitddb303301bed80f700db6f36870642a08016f266 (patch)
treee332b17c20732b22192e2ddec7762c90c19f73b4 /net
parent577b981714b0b3530817569bf705bd74881efc83 (diff)
parentc48d49aab0b5b48b40e00fe43927efed5fc09d88 (diff)
Merge git://git.infradead.org/users/dwmw2/atm
David Woodhouse says: ==================== This is the result of pulling on the thread started by Krzysztof Mazur's original patch 'pppoatm: don't send frames to destroyed vcc'. Various problems in the pppoatm and br2684 code are solved, some of which were easily triggered and would panic the kernel. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/atm/br2684.c55
-rw-r--r--net/atm/common.c12
-rw-r--r--net/atm/pppoatm.c68
3 files changed, 124 insertions, 11 deletions
diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index 8eb6fbe8d8d..403e71fa88f 100644
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -68,6 +68,8 @@ struct br2684_vcc {
/* keep old push, pop functions for chaining */
void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb);
void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb);
+ void (*old_release_cb)(struct atm_vcc *vcc);
+ struct module *old_owner;
enum br2684_encaps encaps;
struct list_head brvccs;
#ifdef CONFIG_ATM_BR2684_IPFILTER
@@ -269,6 +271,17 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
return !atmvcc->send(atmvcc, skb);
}
+static void br2684_release_cb(struct atm_vcc *atmvcc)
+{
+ struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
+
+ if (atomic_read(&brvcc->qspace) > 0)
+ netif_wake_queue(brvcc->device);
+
+ if (brvcc->old_release_cb)
+ brvcc->old_release_cb(atmvcc);
+}
+
static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
const struct br2684_dev *brdev)
{
@@ -280,6 +293,8 @@ static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
{
struct br2684_dev *brdev = BRPRIV(dev);
struct br2684_vcc *brvcc;
+ struct atm_vcc *atmvcc;
+ netdev_tx_t ret = NETDEV_TX_OK;
pr_debug("skb_dst(skb)=%p\n", skb_dst(skb));
read_lock(&devs_lock);
@@ -290,9 +305,26 @@ static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
dev->stats.tx_carrier_errors++;
/* netif_stop_queue(dev); */
dev_kfree_skb(skb);
- read_unlock(&devs_lock);
- return NETDEV_TX_OK;
+ goto out_devs;
}
+ atmvcc = brvcc->atmvcc;
+
+ bh_lock_sock(sk_atm(atmvcc));
+
+ if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) ||
+ test_bit(ATM_VF_CLOSE, &atmvcc->flags) ||
+ !test_bit(ATM_VF_READY, &atmvcc->flags)) {
+ dev->stats.tx_dropped++;
+ dev_kfree_skb(skb);
+ goto out;
+ }
+
+ if (sock_owned_by_user(sk_atm(atmvcc))) {
+ netif_stop_queue(brvcc->device);
+ ret = NETDEV_TX_BUSY;
+ goto out;
+ }
+
if (!br2684_xmit_vcc(skb, dev, brvcc)) {
/*
* We should probably use netif_*_queue() here, but that
@@ -304,8 +336,11 @@ static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
dev->stats.tx_errors++;
dev->stats.tx_fifo_errors++;
}
+ out:
+ bh_unlock_sock(sk_atm(atmvcc));
+ out_devs:
read_unlock(&devs_lock);
- return NETDEV_TX_OK;
+ return ret;
}
/*
@@ -378,9 +413,10 @@ static void br2684_close_vcc(struct br2684_vcc *brvcc)
list_del(&brvcc->brvccs);
write_unlock_irq(&devs_lock);
brvcc->atmvcc->user_back = NULL; /* what about vcc->recvq ??? */
+ brvcc->atmvcc->release_cb = brvcc->old_release_cb;
brvcc->old_push(brvcc->atmvcc, NULL); /* pass on the bad news */
+ module_put(brvcc->old_owner);
kfree(brvcc);
- module_put(THIS_MODULE);
}
/* when AAL5 PDU comes in: */
@@ -554,9 +590,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
brvcc->encaps = (enum br2684_encaps)be.encaps;
brvcc->old_push = atmvcc->push;
brvcc->old_pop = atmvcc->pop;
+ brvcc->old_release_cb = atmvcc->release_cb;
+ brvcc->old_owner = atmvcc->owner;
barrier();
atmvcc->push = br2684_push;
atmvcc->pop = br2684_pop;
+ atmvcc->release_cb = br2684_release_cb;
+ atmvcc->owner = THIS_MODULE;
/* initialize netdev carrier state */
if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
@@ -695,10 +735,13 @@ static int br2684_ioctl(struct socket *sock, unsigned int cmd,
return -ENOIOCTLCMD;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
- if (cmd == ATM_SETBACKEND)
+ if (cmd == ATM_SETBACKEND) {
+ if (sock->state != SS_CONNECTED)
+ return -EINVAL;
return br2684_regvcc(atmvcc, argp);
- else
+ } else {
return br2684_create(argp);
+ }
#ifdef CONFIG_ATM_BR2684_IPFILTER
case BR2684_SETFILT:
if (atmvcc->push != br2684_push)
diff --git a/net/atm/common.c b/net/atm/common.c
index 0c0ad930a63..806fc0a4005 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -126,10 +126,19 @@ static void vcc_write_space(struct sock *sk)
rcu_read_unlock();
}
+static void vcc_release_cb(struct sock *sk)
+{
+ struct atm_vcc *vcc = atm_sk(sk);
+
+ if (vcc->release_cb)
+ vcc->release_cb(vcc);
+}
+
static struct proto vcc_proto = {
.name = "VCC",
.owner = THIS_MODULE,
.obj_size = sizeof(struct atm_vcc),
+ .release_cb = vcc_release_cb,
};
int vcc_create(struct net *net, struct socket *sock, int protocol, int family)
@@ -156,7 +165,9 @@ int vcc_create(struct net *net, struct socket *sock, int protocol, int family)
atomic_set(&sk->sk_rmem_alloc, 0);
vcc->push = NULL;
vcc->pop = NULL;
+ vcc->owner = NULL;
vcc->push_oam = NULL;
+ vcc->release_cb = NULL;
vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */
vcc->atm_options = vcc->aal_options = 0;
sk->sk_destruct = vcc_sock_destruct;
@@ -175,6 +186,7 @@ static void vcc_destroy_socket(struct sock *sk)
vcc->dev->ops->close(vcc);
if (vcc->push)
vcc->push(vcc, NULL); /* atmarpd has no push */
+ module_put(vcc->owner);
while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
atm_return(vcc, skb->truesize);
diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
index 226dca98944..8c93267ce96 100644
--- a/net/atm/pppoatm.c
+++ b/net/atm/pppoatm.c
@@ -60,6 +60,8 @@ struct pppoatm_vcc {
struct atm_vcc *atmvcc; /* VCC descriptor */
void (*old_push)(struct atm_vcc *, struct sk_buff *);
void (*old_pop)(struct atm_vcc *, struct sk_buff *);
+ void (*old_release_cb)(struct atm_vcc *);
+ struct module *old_owner;
/* keep old push/pop for detaching */
enum pppoatm_encaps encaps;
atomic_t inflight;
@@ -107,6 +109,24 @@ static void pppoatm_wakeup_sender(unsigned long arg)
ppp_output_wakeup((struct ppp_channel *) arg);
}
+static void pppoatm_release_cb(struct atm_vcc *atmvcc)
+{
+ struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
+
+ /*
+ * As in pppoatm_pop(), it's safe to clear the BLOCKED bit here because
+ * the wakeup *can't* race with pppoatm_send(). They both hold the PPP
+ * channel's ->downl lock. And the potential race with *setting* it,
+ * which leads to the double-check dance in pppoatm_may_send(), doesn't
+ * exist here. In the sock_owned_by_user() case in pppoatm_send(), we
+ * set the BLOCKED bit while the socket is still locked. We know that
+ * ->release_cb() can't be called until that's done.
+ */
+ if (test_and_clear_bit(BLOCKED, &pvcc->blocked))
+ tasklet_schedule(&pvcc->wakeup_tasklet);
+ if (pvcc->old_release_cb)
+ pvcc->old_release_cb(atmvcc);
+}
/*
* This gets called every time the ATM card has finished sending our
* skb. The ->old_pop will take care up normal atm flow control,
@@ -151,12 +171,11 @@ static void pppoatm_unassign_vcc(struct atm_vcc *atmvcc)
pvcc = atmvcc_to_pvcc(atmvcc);
atmvcc->push = pvcc->old_push;
atmvcc->pop = pvcc->old_pop;
+ atmvcc->release_cb = pvcc->old_release_cb;
tasklet_kill(&pvcc->wakeup_tasklet);
ppp_unregister_channel(&pvcc->chan);
atmvcc->user_back = NULL;
kfree(pvcc);
- /* Gee, I hope we have the big kernel lock here... */
- module_put(THIS_MODULE);
}
/* Called when an AAL5 PDU comes in */
@@ -165,9 +184,13 @@ static void pppoatm_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
pr_debug("\n");
if (skb == NULL) { /* VCC was closed */
+ struct module *module;
+
pr_debug("removing ATMPPP VCC %p\n", pvcc);
+ module = pvcc->old_owner;
pppoatm_unassign_vcc(atmvcc);
atmvcc->push(atmvcc, NULL); /* Pass along bad news */
+ module_put(module);
return;
}
atm_return(atmvcc, skb->truesize);
@@ -211,7 +234,7 @@ error:
ppp_input_error(&pvcc->chan, 0);
}
-static inline int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
+static int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
{
/*
* It's not clear that we need to bother with using atm_may_send()
@@ -269,10 +292,33 @@ static inline int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
{
struct pppoatm_vcc *pvcc = chan_to_pvcc(chan);
+ struct atm_vcc *vcc;
+ int ret;
+
ATM_SKB(skb)->vcc = pvcc->atmvcc;
pr_debug("(skb=0x%p, vcc=0x%p)\n", skb, pvcc->atmvcc);
if (skb->data[0] == '\0' && (pvcc->flags & SC_COMP_PROT))
(void) skb_pull(skb, 1);
+
+ vcc = ATM_SKB(skb)->vcc;
+ bh_lock_sock(sk_atm(vcc));
+ if (sock_owned_by_user(sk_atm(vcc))) {
+ /*
+ * Needs to happen (and be flushed, hence test_and_) before we unlock
+ * the socket. It needs to be seen by the time our ->release_cb gets
+ * called.
+ */
+ test_and_set_bit(BLOCKED, &pvcc->blocked);
+ goto nospace;
+ }
+ if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
+ test_bit(ATM_VF_CLOSE, &vcc->flags) ||
+ !test_bit(ATM_VF_READY, &vcc->flags)) {
+ bh_unlock_sock(sk_atm(vcc));
+ kfree_skb(skb);
+ return DROP_PACKET;
+ }
+
switch (pvcc->encaps) { /* LLC encapsulation needed */
case e_llc:
if (skb_headroom(skb) < LLC_LEN) {
@@ -285,8 +331,10 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
}
consume_skb(skb);
skb = n;
- if (skb == NULL)
+ if (skb == NULL) {
+ bh_unlock_sock(sk_atm(vcc));
return DROP_PACKET;
+ }
} else if (!pppoatm_may_send(pvcc, skb->truesize))
goto nospace;
memcpy(skb_push(skb, LLC_LEN), pppllc, LLC_LEN);
@@ -296,6 +344,7 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
goto nospace;
break;
case e_autodetect:
+ bh_unlock_sock(sk_atm(vcc));
pr_debug("Trying to send without setting encaps!\n");
kfree_skb(skb);
return 1;
@@ -305,9 +354,12 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
ATM_SKB(skb)->atm_options = ATM_SKB(skb)->vcc->atm_options;
pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n",
skb, ATM_SKB(skb)->vcc, ATM_SKB(skb)->vcc->dev);
- return ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
+ ret = ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
? DROP_PACKET : 1;
+ bh_unlock_sock(sk_atm(vcc));
+ return ret;
nospace:
+ bh_unlock_sock(sk_atm(vcc));
/*
* We don't have space to send this SKB now, but we might have
* already applied SC_COMP_PROT compression, so may need to undo
@@ -362,6 +414,8 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
atomic_set(&pvcc->inflight, NONE_INFLIGHT);
pvcc->old_push = atmvcc->push;
pvcc->old_pop = atmvcc->pop;
+ pvcc->old_owner = atmvcc->owner;
+ pvcc->old_release_cb = atmvcc->release_cb;
pvcc->encaps = (enum pppoatm_encaps) be.encaps;
pvcc->chan.private = pvcc;
pvcc->chan.ops = &pppoatm_ops;
@@ -377,7 +431,9 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
atmvcc->user_back = pvcc;
atmvcc->push = pppoatm_push;
atmvcc->pop = pppoatm_pop;
+ atmvcc->release_cb = pppoatm_release_cb;
__module_get(THIS_MODULE);
+ atmvcc->owner = THIS_MODULE;
/* re-process everything received between connection setup and
backend setup */
@@ -406,6 +462,8 @@ static int pppoatm_ioctl(struct socket *sock, unsigned int cmd,
return -ENOIOCTLCMD;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
+ if (sock->state != SS_CONNECTED)
+ return -EINVAL;
return pppoatm_assign_vcc(atmvcc, argp);
}
case PPPIOCGCHAN: