net: ppp: use sk_unattached_filter api

For the ppp driver, there are currently two open-coded BPF filters in use,
that is, pass_filter and active_filter. Migrate both to make proper use
of sk_unattached_filter_{create,destroy} API so that the actual BPF code
is decoupled from direct access, and filters can be jited as a side-effect
by the internal filter compiler.

Joint work with Alexei Starovoitov.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linux-ppp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Borkmann 2014-03-28 18:58:23 +01:00 committed by David S. Miller
parent 164d8c6665
commit 568f194e8b

View file

@ -143,9 +143,8 @@ struct ppp {
struct sk_buff_head mrq; /* MP: receive reconstruction queue */
#endif /* CONFIG_PPP_MULTILINK */
#ifdef CONFIG_PPP_FILTER
struct sock_filter *pass_filter; /* filter for packets to pass */
struct sock_filter *active_filter;/* filter for pkts to reset idle */
unsigned pass_len, active_len;
struct sk_filter *pass_filter; /* filter for packets to pass */
struct sk_filter *active_filter;/* filter for pkts to reset idle */
#endif /* CONFIG_PPP_FILTER */
struct net *ppp_net; /* the net we belong to */
struct ppp_link_stats stats64; /* 64 bit network stats */
@ -755,28 +754,42 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case PPPIOCSPASS:
{
struct sock_filter *code;
err = get_filter(argp, &code);
if (err >= 0) {
struct sock_fprog fprog = {
.len = err,
.filter = code,
};
ppp_lock(ppp);
kfree(ppp->pass_filter);
ppp->pass_filter = code;
ppp->pass_len = err;
if (ppp->pass_filter)
sk_unattached_filter_destroy(ppp->pass_filter);
err = sk_unattached_filter_create(&ppp->pass_filter,
&fprog);
kfree(code);
ppp_unlock(ppp);
err = 0;
}
break;
}
case PPPIOCSACTIVE:
{
struct sock_filter *code;
err = get_filter(argp, &code);
if (err >= 0) {
struct sock_fprog fprog = {
.len = err,
.filter = code,
};
ppp_lock(ppp);
kfree(ppp->active_filter);
ppp->active_filter = code;
ppp->active_len = err;
if (ppp->active_filter)
sk_unattached_filter_destroy(ppp->active_filter);
err = sk_unattached_filter_create(&ppp->active_filter,
&fprog);
kfree(code);
ppp_unlock(ppp);
err = 0;
}
break;
}
@ -1184,7 +1197,7 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
a four-byte PPP header on each packet */
*skb_push(skb, 2) = 1;
if (ppp->pass_filter &&
sk_run_filter(skb, ppp->pass_filter) == 0) {
SK_RUN_FILTER(ppp->pass_filter, skb) == 0) {
if (ppp->debug & 1)
netdev_printk(KERN_DEBUG, ppp->dev,
"PPP: outbound frame "
@ -1194,7 +1207,7 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
}
/* if this packet passes the active filter, record the time */
if (!(ppp->active_filter &&
sk_run_filter(skb, ppp->active_filter) == 0))
SK_RUN_FILTER(ppp->active_filter, skb) == 0))
ppp->last_xmit = jiffies;
skb_pull(skb, 2);
#else
@ -1818,7 +1831,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
*skb_push(skb, 2) = 0;
if (ppp->pass_filter &&
sk_run_filter(skb, ppp->pass_filter) == 0) {
SK_RUN_FILTER(ppp->pass_filter, skb) == 0) {
if (ppp->debug & 1)
netdev_printk(KERN_DEBUG, ppp->dev,
"PPP: inbound frame "
@ -1827,7 +1840,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
return;
}
if (!(ppp->active_filter &&
sk_run_filter(skb, ppp->active_filter) == 0))
SK_RUN_FILTER(ppp->active_filter, skb) == 0))
ppp->last_recv = jiffies;
__skb_pull(skb, 2);
} else
@ -2672,6 +2685,10 @@ ppp_create_interface(struct net *net, int unit, int *retp)
ppp->minseq = -1;
skb_queue_head_init(&ppp->mrq);
#endif /* CONFIG_PPP_MULTILINK */
#ifdef CONFIG_PPP_FILTER
ppp->pass_filter = NULL;
ppp->active_filter = NULL;
#endif /* CONFIG_PPP_FILTER */
/*
* drum roll: don't forget to set
@ -2802,10 +2819,15 @@ static void ppp_destroy_interface(struct ppp *ppp)
skb_queue_purge(&ppp->mrq);
#endif /* CONFIG_PPP_MULTILINK */
#ifdef CONFIG_PPP_FILTER
kfree(ppp->pass_filter);
ppp->pass_filter = NULL;
kfree(ppp->active_filter);
ppp->active_filter = NULL;
if (ppp->pass_filter) {
sk_unattached_filter_destroy(ppp->pass_filter);
ppp->pass_filter = NULL;
}
if (ppp->active_filter) {
sk_unattached_filter_destroy(ppp->active_filter);
ppp->active_filter = NULL;
}
#endif /* CONFIG_PPP_FILTER */
kfree_skb(ppp->xmit_pending);