net: ptp: do not reimplement PTP/BPF classifier

There are currently pch_gbe, cpts, and ixp4xx_eth drivers that open-code
and reimplement a BPF classifier for the PTP protocol. Since all of them
effectively do the very same thing and load the very same PTP/BPF filter,
we can just consolidate that code by introducing ptp_classify_raw() in
the time-stamping core framework which can be used in drivers.

As drivers get initialized after bootstrapping the core networking
subsystem, they can make use of ptp_insns wrapped through
ptp_classify_raw(), which allows to simplify and remove PTP classifier
setup code in drivers.

Joint work with Alexei Starovoitov.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Richard Cochran <richard.cochran@omicron.at>
Cc: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 12 insertions, 38 deletions

diff --git a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
index 464e91058c81..73e66838cfef 100644
--- a/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
+++ b/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
@@ -120,10 +120,6 @@ static void pch_gbe_mdio_write(struct net_device *netdev, int addr, int reg,
                                int data);
 static void pch_gbe_set_multi(struct net_device *netdev);
 
-static struct sock_filter ptp_filter[] = {
-        PTP_FILTER
-};
-
 static int pch_ptp_match(struct sk_buff *skb, u16 uid_hi, u32 uid_lo, u16 seqid)
 {
         u8 *data = skb->data;
@@ -131,7 +127,7 @@ static int pch_ptp_match(struct sk_buff *skb, u16 uid_hi, u32 uid_lo, u16 seqid)
         u16 *hi, *id;
         u32 lo;
 
-        if (sk_run_filter(skb, ptp_filter) == PTP_CLASS_NONE)
+        if (ptp_classify_raw(skb) == PTP_CLASS_NONE)
                 return 0;
 
         offset = ETH_HLEN + IPV4_HLEN(data) + UDP_HLEN;
@@ -2635,11 +2631,6 @@ static int pch_gbe_probe(struct pci_dev *pdev,
 
         adapter->ptp_pdev = pci_get_bus_and_slot(adapter->pdev->bus->number,
                                                PCI_DEVFN(12, 4));
-        if (ptp_filter_init(ptp_filter, ARRAY_SIZE(ptp_filter))) {
-                dev_err(&pdev->dev, "Bad ptp filter\n");
-                ret = -EINVAL;
-                goto err_free_netdev;
-        }
 
         netdev->netdev_ops = &pch_gbe_netdev_ops;
         netdev->watchdog_timeo = PCH_GBE_WATCHDOG_PERIOD;
diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index 372cb192c5aa..a3bbf59eaafd 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -31,10 +31,6 @@
 
 #ifdef CONFIG_TI_CPTS
 
-static struct sock_filter ptp_filter[] = {
-        PTP_FILTER
-};
-
 #define cpts_read32(c, r)       __raw_readl(&c->reg->r)
 #define cpts_write32(c, v, r)   __raw_writel(v, &c->reg->r)
 
@@ -301,7 +297,7 @@ static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type)
         u64 ns = 0;
         struct cpts_event *event;
         struct list_head *this, *next;
-        unsigned int class = sk_run_filter(skb, ptp_filter);
+        unsigned int class = ptp_classify_raw(skb);
         unsigned long flags;
         u16 seqid;
         u8 mtype;
@@ -372,10 +368,6 @@ int cpts_register(struct device *dev, struct cpts *cpts,
         int err, i;
         unsigned long flags;
 
-        if (ptp_filter_init(ptp_filter, ARRAY_SIZE(ptp_filter))) {
-                pr_err("cpts: bad ptp filter\n");
-                return -EINVAL;
-        }
         cpts->info = cpts_info;
         cpts->clock = ptp_clock_register(&cpts->info, dev);
         if (IS_ERR(cpts->clock)) {
diff --git a/drivers/net/ethernet/xscale/ixp4xx_eth.c b/drivers/net/ethernet/xscale/ixp4xx_eth.c
index 25283f17d82f..f7e0f0f7c2e2 100644
--- a/drivers/net/ethernet/xscale/ixp4xx_eth.c
+++ b/drivers/net/ethernet/xscale/ixp4xx_eth.c
@@ -256,10 +256,6 @@ static int ports_open;
 static struct port *npe_port_tab[MAX_NPES];
 static struct dma_pool *dma_pool;
 
-static struct sock_filter ptp_filter[] = {
-        PTP_FILTER
-};
-
 static int ixp_ptp_match(struct sk_buff *skb, u16 uid_hi, u32 uid_lo, u16 seqid)
 {
         u8 *data = skb->data;
@@ -267,7 +263,7 @@ static int ixp_ptp_match(struct sk_buff *skb, u16 uid_hi, u32 uid_lo, u16 seqid)
         u16 *hi, *id;
         u32 lo;
 
-        if (sk_run_filter(skb, ptp_filter) != PTP_CLASS_V1_IPV4)
+        if (ptp_classify_raw(skb) != PTP_CLASS_V1_IPV4)
                 return 0;
 
         offset = ETH_HLEN + IPV4_HLEN(data) + UDP_HLEN;
@@ -1413,11 +1409,6 @@ static int eth_init_one(struct platform_device *pdev)
         char phy_id[MII_BUS_ID_SIZE + 3];
         int err;
 
-        if (ptp_filter_init(ptp_filter, ARRAY_SIZE(ptp_filter))) {
-                pr_err("ixp4xx_eth: bad ptp filter\n");
-                return -EINVAL;
-        }
-
         if (!(dev = alloc_etherdev(sizeof(struct port))))
                 return -ENOMEM;
 
diff --git a/include/linux/ptp_classify.h b/include/linux/ptp_classify.h
index 3decfa4d3732..6d3b0a2ef9ce 100644
--- a/include/linux/ptp_classify.h
+++ b/include/linux/ptp_classify.h
@@ -80,14 +80,6 @@
 #define OP_RETA (BPF_RET | BPF_A)
 #define OP_RETK (BPF_RET | BPF_K)
 
-static inline int ptp_filter_init(struct sock_filter *f, int len)
-{
-        if (OP_LDH == f[0].code)
-                return sk_chk_filter(f, len);
-        else
-                return 0;
-}
-
 #define PTP_FILTER \
         {OP_LDH,        0,   0, OFF_ETYPE               }, /*              */ \
         {OP_JEQ,        0,  12, ETH_P_IP                }, /* f goto L20   */ \
@@ -133,4 +125,6 @@ static inline int ptp_filter_init(struct sock_filter *f, int len)
         {OP_RETA,       0,   0, 0                       }, /*              */ \
 /*L6x*/ {OP_RETK,       0,   0, PTP_CLASS_NONE          },
 
+unsigned int ptp_classify_raw(const struct sk_buff *skb);
+
 #endif
diff --git a/net/core/timestamping.c b/net/core/timestamping.c
index e43d56acf803..9ff26b3cc021 100644
--- a/net/core/timestamping.c
+++ b/net/core/timestamping.c
@@ -25,11 +25,17 @@
 
 static struct sk_filter *ptp_insns __read_mostly;
 
+unsigned int ptp_classify_raw(const struct sk_buff *skb)
+{
+        return SK_RUN_FILTER(ptp_insns, skb);
+}
+EXPORT_SYMBOL_GPL(ptp_classify_raw);
+
 static unsigned int classify(const struct sk_buff *skb)
 {
         if (likely(skb->dev && skb->dev->phydev &&
                    skb->dev->phydev->drv))
-                return SK_RUN_FILTER(ptp_insns, skb);
+                return ptp_classify_raw(skb);
         else
                 return PTP_CLASS_NONE;
 }