Commit 568f194e authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
Browse files

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: default avatarDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linux-ppp@vger.kernel.org
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 164d8c66

drivers/net/ppp/ppp_generic.c

+41 −19
Original line number Diff line number Diff line
@@ -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);

	if (ppp->pass_filter) {

		sk_unattached_filter_destroy(ppp->pass_filter);

		ppp->pass_filter = NULL;

	kfree(ppp->active_filter);

	}



	if (ppp->active_filter) {

		sk_unattached_filter_destroy(ppp->active_filter);

		ppp->active_filter = NULL;

	}

#endif /* CONFIG_PPP_FILTER */



	kfree_skb(ppp->xmit_pending);

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