diff options
Diffstat (limited to 'net/atm/pppoatm.c')
| -rw-r--r-- | net/atm/pppoatm.c | 68 |
1 files changed, 63 insertions, 5 deletions
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: |