net: isdn: use sk_unattached_filter api

Similarly as in ppp, we need to migrate the ISDN/PPP code to make use
of the sk_unattached_filter api in order to decouple having direct
filter structure access. By using sk_unattached_filter_{create,destroy},
we can allow for the possibility to jit compile filters for faster
filter verdicts as well.

Joint work with Alexei Starovoitov.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: isdn4linux@listserv.isdn4linux.de
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 43 insertions, 23 deletions

diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c
index 38ceac5053a0..a5da511e3c9a 100644
--- a/drivers/isdn/i4l/isdn_ppp.c
+++ b/drivers/isdn/i4l/isdn_ppp.c
@@ -378,10 +378,15 @@ isdn_ppp_release(int min, struct file *file)
         is->slcomp = NULL;
 #endif
 #ifdef CONFIG_IPPP_FILTER
-        kfree(is->pass_filter);
-        is->pass_filter = NULL;
-        kfree(is->active_filter);
-        is->active_filter = NULL;
+        if (is->pass_filter) {
+                sk_unattached_filter_destroy(is->pass_filter);
+                is->pass_filter = NULL;
+        }
+
+        if (is->active_filter) {
+                sk_unattached_filter_destroy(is->active_filter);
+                is->active_filter = NULL;
+        }
 #endif
 
 /* TODO: if this was the previous master: link the stuff to the new master */
@@ -629,25 +634,41 @@ isdn_ppp_ioctl(int min, struct file *file, unsigned int cmd, unsigned long arg)
 #ifdef CONFIG_IPPP_FILTER
         case PPPIOCSPASS:
         {
+                struct sock_fprog fprog;
                 struct sock_filter *code;
-                int len = get_filter(argp, &code);
+                int err, len = get_filter(argp, &code);
+
                 if (len < 0)
                         return len;
-                kfree(is->pass_filter);
-                is->pass_filter = code;
-                is->pass_len = len;
-                break;
+
+                fprog.len = len;
+                fprog.filter = code;
+
+                if (is->pass_filter)
+                        sk_unattached_filter_destroy(is->pass_filter);
+                err = sk_unattached_filter_create(&is->pass_filter, &fprog);
+                kfree(code);
+
+                return err;
         }
         case PPPIOCSACTIVE:
         {
+                struct sock_fprog fprog;
                 struct sock_filter *code;
-                int len = get_filter(argp, &code);
+                int err, len = get_filter(argp, &code);
+
                 if (len < 0)
                         return len;
-                kfree(is->active_filter);
-                is->active_filter = code;
-                is->active_len = len;
-                break;
+
+                fprog.len = len;
+                fprog.filter = code;
+
+                if (is->active_filter)
+                        sk_unattached_filter_destroy(is->active_filter);
+                err = sk_unattached_filter_create(&is->active_filter, &fprog);
+                kfree(code);
+
+                return err;
         }
 #endif /* CONFIG_IPPP_FILTER */
         default:
@@ -1147,14 +1168,14 @@ isdn_ppp_push_higher(isdn_net_dev *net_dev, isdn_net_local *lp, struct sk_buff *
         }
 
         if (is->pass_filter
-            && sk_run_filter(skb, is->pass_filter) == 0) {
+            && SK_RUN_FILTER(is->pass_filter, skb) == 0) {
                 if (is->debug & 0x2)
                         printk(KERN_DEBUG "IPPP: inbound frame filtered.\n");
                 kfree_skb(skb);
                 return;
         }
         if (!(is->active_filter
-              && sk_run_filter(skb, is->active_filter) == 0)) {
+              && SK_RUN_FILTER(is->active_filter, skb) == 0)) {
                 if (is->debug & 0x2)
                         printk(KERN_DEBUG "IPPP: link-active filter: resetting huptimer.\n");
                 lp->huptimer = 0;
@@ -1293,14 +1314,14 @@ isdn_ppp_xmit(struct sk_buff *skb, struct net_device *netdev)
         }
 
         if (ipt->pass_filter
-            && sk_run_filter(skb, ipt->pass_filter) == 0) {
+            && SK_RUN_FILTER(ipt->pass_filter, skb) == 0) {
                 if (ipt->debug & 0x4)
                         printk(KERN_DEBUG "IPPP: outbound frame filtered.\n");
                 kfree_skb(skb);
                 goto unlock;
         }
         if (!(ipt->active_filter
-              && sk_run_filter(skb, ipt->active_filter) == 0)) {
+              && SK_RUN_FILTER(ipt->active_filter, skb) == 0)) {
                 if (ipt->debug & 0x4)
                         printk(KERN_DEBUG "IPPP: link-active filter: resetting huptimer.\n");
                 lp->huptimer = 0;
@@ -1490,9 +1511,9 @@ int isdn_ppp_autodial_filter(struct sk_buff *skb, isdn_net_local *lp)
         }
 
         drop |= is->pass_filter
-                && sk_run_filter(skb, is->pass_filter) == 0;
+                && SK_RUN_FILTER(is->pass_filter, skb) == 0;
         drop |= is->active_filter
-                && sk_run_filter(skb, is->active_filter) == 0;
+                && SK_RUN_FILTER(is->active_filter, skb) == 0;
 
         skb_push(skb, IPPP_MAX_HEADER - 4);
         return drop;
diff --git a/include/linux/isdn_ppp.h b/include/linux/isdn_ppp.h
index d5f62bc5f4be..8e10f57f109f 100644
--- a/include/linux/isdn_ppp.h
+++ b/include/linux/isdn_ppp.h
@@ -180,9 +180,8 @@ struct ippp_struct {
   struct slcompress *slcomp;
 #endif
 #ifdef CONFIG_IPPP_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
   unsigned long debug;
   struct isdn_ppp_compressor *compressor,*decompressor;