diff options
author | David S. Miller <davem@davemloft.net> | 2012-12-02 02:45:24 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2012-12-02 02:45:24 +0100 |
commit | ddb303301bed80f700db6f36870642a08016f266 (patch) | |
tree | e332b17c20732b22192e2ddec7762c90c19f73b4 /net | |
parent | qlcnic: remove duplicated include from qlcnic_sysfs.c (diff) | |
parent | solos-pci: remove list_vccs() debugging function (diff) | |
download | linux-ddb303301bed80f700db6f36870642a08016f266.tar.xz linux-ddb303301bed80f700db6f36870642a08016f266.zip |
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.c | 55 | ||||
-rw-r--r-- | net/atm/common.c | 12 | ||||
-rw-r--r-- | net/atm/pppoatm.c | 68 |
3 files changed, 124 insertions, 11 deletions
diff --git a/net/atm/br2684.c b/net/atm/br2684.c index 8eb6fbe8d8dd..403e71fa88fe 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 0c0ad930a632..806fc0a40051 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 226dca989448..8c93267ce969 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: |