[PATCH net-next 0/15] Neighbour table and ax25 cleanups

[PATCH net-next 0/15] Neighbour table and ax25 cleanups

[Eric W. Biederman]

While looking at the neighbour table to what it would take to allow
using next hops in a different address family than the current packets
I found a partial resolution for my issues and I stumbled upon some
work that makes the neighbour table code easier to understand and
maintain.

Long ago in a much younger kernel ax25 found a hack to use
dev_rebuild_header to transmit it's packets instead of going through
what today is ndo_start_xmit.

When the neighbour table was rewritten into it's current form the ax25
code was such a challenge that arp_broken_ops appeard in arp.c and
neigh_compat_output appeared in neighbour.c to keep the ax25 hack alive.

With a little bit of work I was able to remove some of the hack that
is the ax25 transmit path for ip packets and to isolate what remains
into a slightly more readable piece of code in ax25_ip.c.  Removing the
need for the generic code to worry about ax25 special cases.

After cleaning up the old ax25 hacks I also performed a little bit of
work on neigh_resolve_output to remove the need for a dst entry and to
ensure cached headers get a deterministic protocol value in their cached
header.   This guarantees that a cached header will not be different
depending on which protocol of packet is transmitted, and it allows
packets to be transmitted that don't have a dst entry.  There remains
a small amount of code that takes advantage of when packets have a dst
entry but that is something different.

Eric W. Biederman (15):
      ax25: In ax25_rebuild_header add missing kfree_skb
      rose: Set the destination address in rose_header
      rose: Transmit packets in rose_xmit not rose_rebuild_header
      ax25/kiss: Replace ax_header_ops with ax25_header_ops
      ax25/6pack: Replace sp_header_ops with ax25_header_ops
      ax25: Make ax25_header and ax25_rebuild_header static
      ax25: Refactor to use private neighbour operations.
      arp: Remove special case to give AX25 it's open arp operations.
      neigh: Move neigh_compat_output into ax25_ip.c
      ax25: Stop calling/abusing dev_rebuild_header
      ax25: Stop depending on arp_find
      net: Kill dev_rebuild_header
      arp: Kill arp_find
      neigh: Don't require dst in neigh_hh_init
      neigh: Don't require a dst in neigh_resolve_output

 drivers/firewire/net.c                    |  13 ----
 drivers/isdn/i4l/isdn_net.c               |  33 ----------
 drivers/media/dvb-core/dvb_net.c          |   1 -
 drivers/net/arcnet/arcnet.c               |  55 ----------------
 drivers/net/hamradio/6pack.c              |  30 +--------
 drivers/net/hamradio/baycom_epp.c         |   2 +
 drivers/net/hamradio/bpqether.c           |   2 +
 drivers/net/hamradio/dmascc.c             |   2 +
 drivers/net/hamradio/hdlcdrv.c            |   2 +
 drivers/net/hamradio/mkiss.c              |  35 +---------
 drivers/net/hamradio/scc.c                |   2 +
 drivers/net/hamradio/yam.c                |   2 +
 drivers/net/ipvlan/ipvlan_main.c          |   1 -
 drivers/net/macvlan.c                     |   1 -
 drivers/net/wireless/hostap/hostap_main.c |   1 -
 include/linux/etherdevice.h               |   1 -
 include/linux/netdevice.h                 |  12 +---
 include/net/arp.h                         |   1 -
 include/net/ax25.h                        |   8 ++-
 include/net/neighbour.h                   |   2 +-
 net/802/fc.c                              |  21 ------
 net/802/fddi.c                            |  26 --------
 net/802/hippi.c                           |  28 --------
 net/8021q/vlan_dev.c                      |  35 ----------
 net/ax25/ax25_ip.c                        |  76 +++++++++++++++++-----
 net/core/neighbour.c                      |  34 ++--------
 net/decnet/dn_neigh.c                     |   1 +
 net/ethernet/eth.c                        |  34 ----------
 net/ipv4/arp.c                            | 103 +-----------------------------
 net/ipv6/ndisc.c                          |   1 +
 net/netrom/nr_dev.c                       |  31 ---------
 net/rose/rose_dev.c                       |  53 ++++-----------
 32 files changed, 105 insertions(+), 544 deletions(-)

[PATCH net-next 01/15] ax25: In ax25_rebuild_header add missing kfree_skb

[Eric W. Biederman]

In the unlikely (impossible?) event that we attempt to transmit
an ax25 packet over a non-ax25 device free the skb so we don't
leak it.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 net/ax25/ax25_ip.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index 67de6b33f2c3..db3c283821d1 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -129,6 +129,7 @@ int ax25_rebuild_header(struct sk_buff *skb)
 		dev = skb->dev;
 
 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
+		kfree_skb(skb);
 		goto put;
 	}
 
-- 
2.2.1

[PATCH net-next 02/15] rose: Set the destination address in rose_header

[Eric W. Biederman]

Not setting the destination address is a bug that I suspect causes no
problems today, as only the arp code seems to call dev_hard_header and
the description I have of rose is that it is expected to be used with a
static neigbour table.

I have derived the offset and the length of the rose destination address
from rose_rebuild_header where arp_find calls neigh_ha_snapshot to set
the destination address.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 net/rose/rose_dev.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/rose/rose_dev.c b/net/rose/rose_dev.c
index 50005888be57..24d2b40b6c6b 100644
--- a/net/rose/rose_dev.c
+++ b/net/rose/rose_dev.c
@@ -41,6 +41,9 @@ static int rose_header(struct sk_buff *skb, struct net_device *dev,
 {
 	unsigned char *buff = skb_push(skb, ROSE_MIN_LEN + 2);
 
+	if (daddr)
+		memcpy(buff + 7, daddr, dev->addr_len);
+
 	*buff++ = ROSE_GFI | ROSE_Q_BIT;
 	*buff++ = 0x00;
 	*buff++ = ROSE_DATA;
-- 
2.2.1

[PATCH net-next 03/15] rose: Transmit packets in rose_xmit not rose_rebuild_header

[Eric W. Biederman]

Patterned after the similar code in net/rom this turns out
to be a trivial obviously correct transmformation.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 net/rose/rose_dev.c | 38 +++++++++++---------------------------
 1 file changed, 11 insertions(+), 27 deletions(-)

diff --git a/net/rose/rose_dev.c b/net/rose/rose_dev.c
index 24d2b40b6c6b..90209c1fa49b 100644
--- a/net/rose/rose_dev.c
+++ b/net/rose/rose_dev.c
@@ -59,38 +59,14 @@ static int rose_header(struct sk_buff *skb, struct net_device *dev,
 static int rose_rebuild_header(struct sk_buff *skb)
 {
 #ifdef CONFIG_INET
-	struct net_device *dev = skb->dev;
-	struct net_device_stats *stats = &dev->stats;
 	unsigned char *bp = (unsigned char *)skb->data;
-	struct sk_buff *skbn;
-	unsigned int len;
 
 	if (arp_find(bp + 7, skb)) {
 		return 1;
 	}
 
-	if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
-		kfree_skb(skb);
-		return 1;
-	}
-
-	if (skb->sk != NULL)
-		skb_set_owner_w(skbn, skb->sk);
-
-	kfree_skb(skb);
-
-	len = skbn->len;
-
-	if (!rose_route_frame(skbn, NULL)) {
-		kfree_skb(skbn);
-		stats->tx_errors++;
-		return 1;
-	}
-
-	stats->tx_packets++;
-	stats->tx_bytes += len;
 #endif
-	return 1;
+	return 0;
 }
 
 static int rose_set_mac_address(struct net_device *dev, void *addr)
@@ -137,13 +113,21 @@ static int rose_close(struct net_device *dev)
 static netdev_tx_t rose_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct net_device_stats *stats = &dev->stats;
+	unsigned int len = skb->len;
 
 	if (!netif_running(dev)) {
 		printk(KERN_ERR "ROSE: rose_xmit - called when iface is down\n");
 		return NETDEV_TX_BUSY;
 	}
-	dev_kfree_skb(skb);
-	stats->tx_errors++;
+
+	if (!rose_route_frame(skb, NULL)) {
+		dev_kfree_skb(skb);
+		stats->tx_errors++;
+		return NETDEV_TX_OK;
+	}
+
+	stats->tx_packets++;
+	stats->tx_bytes += len;
 	return NETDEV_TX_OK;
 }
 
-- 
2.2.1

[PATCH net-next 04/15] ax25/kiss: Replace ax_header_ops with ax25_header_ops

[Eric W. Biederman]

The two sets of header operations are functionally identical remove the
duplicate definition.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 drivers/net/hamradio/mkiss.c | 33 +--------------------------------
 1 file changed, 1 insertion(+), 32 deletions(-)

diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index f990bb1c3e02..e37c8d515ce8 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -573,32 +573,6 @@ static int ax_open_dev(struct net_device *dev)
 	return 0;
 }
 
-#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
-
-/* Return the frame type ID */
-static int ax_header(struct sk_buff *skb, struct net_device *dev,
-		     unsigned short type, const void *daddr,
-		     const void *saddr, unsigned len)
-{
-#ifdef CONFIG_INET
-	if (type != ETH_P_AX25)
-		return ax25_hard_header(skb, dev, type, daddr, saddr, len);
-#endif
-	return 0;
-}
-
-
-static int ax_rebuild_header(struct sk_buff *skb)
-{
-#ifdef CONFIG_INET
-	return ax25_rebuild_header(skb);
-#else
-	return 0;
-#endif
-}
-
-#endif	/* CONFIG_{AX25,AX25_MODULE} */
-
 /* Open the low-level part of the AX25 channel. Easy! */
 static int ax_open(struct net_device *dev)
 {
@@ -662,11 +636,6 @@ static int ax_close(struct net_device *dev)
 	return 0;
 }
 
-static const struct header_ops ax_header_ops = {
-	.create    = ax_header,
-	.rebuild   = ax_rebuild_header,
-};
-
 static const struct net_device_ops ax_netdev_ops = {
 	.ndo_open            = ax_open_dev,
 	.ndo_stop            = ax_close,
@@ -682,7 +651,7 @@ static void ax_setup(struct net_device *dev)
 	dev->addr_len        = 0;
 	dev->type            = ARPHRD_AX25;
 	dev->tx_queue_len    = 10;
-	dev->header_ops      = &ax_header_ops;
+	dev->header_ops      = &ax25_header_ops;
 	dev->netdev_ops	     = &ax_netdev_ops;
 
 
-- 
2.2.1

[PATCH net-next 05/15] ax25/6pack: Replace sp_header_ops with ax25_header_ops

[Eric W. Biederman]

The two sets of header operations are functionally identical remove
the duplicate definition.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 drivers/net/hamradio/6pack.c | 28 +---------------------------
 1 file changed, 1 insertion(+), 27 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index daca0dee88f3..2533933c79dc 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -284,18 +284,6 @@ static int sp_close(struct net_device *dev)
 	return 0;
 }
 
-/* Return the frame type ID */
-static int sp_header(struct sk_buff *skb, struct net_device *dev,
-		     unsigned short type, const void *daddr,
-		     const void *saddr, unsigned len)
-{
-#ifdef CONFIG_INET
-	if (type != ETH_P_AX25)
-		return ax25_hard_header(skb, dev, type, daddr, saddr, len);
-#endif
-	return 0;
-}
-
 static int sp_set_mac_address(struct net_device *dev, void *addr)
 {
 	struct sockaddr_ax25 *sa = addr;
@@ -309,20 +297,6 @@ static int sp_set_mac_address(struct net_device *dev, void *addr)
 	return 0;
 }
 
-static int sp_rebuild_header(struct sk_buff *skb)
-{
-#ifdef CONFIG_INET
-	return ax25_rebuild_header(skb);
-#else
-	return 0;
-#endif
-}
-
-static const struct header_ops sp_header_ops = {
-	.create		= sp_header,
-	.rebuild	= sp_rebuild_header,
-};
-
 static const struct net_device_ops sp_netdev_ops = {
 	.ndo_open		= sp_open_dev,
 	.ndo_stop		= sp_close,
@@ -337,7 +311,7 @@ static void sp_setup(struct net_device *dev)
 	dev->destructor		= free_netdev;
 	dev->mtu		= SIXP_MTU;
 	dev->hard_header_len	= AX25_MAX_HEADER_LEN;
-	dev->header_ops 	= &sp_header_ops;
+	dev->header_ops 	= &ax25_header_ops;
 
 	dev->addr_len		= AX25_ADDR_LEN;
 	dev->type		= ARPHRD_AX25;
-- 
2.2.1

[PATCH net-next 06/15] ax25: Make ax25_header and ax25_rebuild_header static

[Eric W. Biederman]

The only user is in ax25_ip.c so stop exporting these functions.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 include/net/ax25.h |  3 ---
 net/ax25/ax25_ip.c | 18 ++++++++----------
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/include/net/ax25.h b/include/net/ax25.h
index bf0396e9a5d3..7385a64b61b8 100644
--- a/include/net/ax25.h
+++ b/include/net/ax25.h
@@ -366,9 +366,6 @@ int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
 		  struct net_device *);
 
 /* ax25_ip.c */
-int ax25_hard_header(struct sk_buff *, struct net_device *, unsigned short,
-		     const void *, const void *, unsigned int);
-int ax25_rebuild_header(struct sk_buff *);
 extern const struct header_ops ax25_header_ops;
 
 /* ax25_out.c */
diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index db3c283821d1..d93103ba8cec 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -46,9 +46,9 @@
 
 #ifdef CONFIG_INET
 
-int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
-		     unsigned short type, const void *daddr,
-		     const void *saddr, unsigned int len)
+static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
+			    unsigned short type, const void *daddr,
+			    const void *saddr, unsigned int len)
 {
 	unsigned char *buff;
 
@@ -100,7 +100,7 @@ int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
 	return -AX25_HEADER_LEN;	/* Unfinished header */
 }
 
-int ax25_rebuild_header(struct sk_buff *skb)
+static int ax25_rebuild_header(struct sk_buff *skb)
 {
 	struct sk_buff *ourskb;
 	unsigned char *bp  = skb->data;
@@ -218,14 +218,14 @@ put:
 
 #else	/* INET */
 
-int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
-		     unsigned short type, const void *daddr,
-		     const void *saddr, unsigned int len)
+static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
+			    unsigned short type, const void *daddr,
+			    const void *saddr, unsigned int len)
 {
 	return -AX25_HEADER_LEN;
 }
 
-int ax25_rebuild_header(struct sk_buff *skb)
+static int ax25_rebuild_header(struct sk_buff *skb)
 {
 	return 1;
 }
@@ -237,7 +237,5 @@ const struct header_ops ax25_header_ops = {
 	.rebuild = ax25_rebuild_header,
 };
 
-EXPORT_SYMBOL(ax25_hard_header);
-EXPORT_SYMBOL(ax25_rebuild_header);
 EXPORT_SYMBOL(ax25_header_ops);
 
-- 
2.2.1

[PATCH net-next 07/15] ax25: Refactor to use private neighbour operations.

[Eric W. Biederman]

AX25 already has it's own private arp cache operations to isolate
it's abuse of dev_rebuild_header to transmit packets.  Add a function
ax25_neigh_construct that will allow all of the ax25 devices to
force using these operations, so that the generic arp code does
not need to.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 drivers/net/hamradio/6pack.c      |  2 ++
 drivers/net/hamradio/baycom_epp.c |  2 ++
 drivers/net/hamradio/bpqether.c   |  2 ++
 drivers/net/hamradio/dmascc.c     |  2 ++
 drivers/net/hamradio/hdlcdrv.c    |  2 ++
 drivers/net/hamradio/mkiss.c      |  2 ++
 drivers/net/hamradio/scc.c        |  2 ++
 drivers/net/hamradio/yam.c        |  2 ++
 include/net/ax25.h                |  5 +++++
 net/ax25/ax25_ip.c                | 21 +++++++++++++++++++++
 10 files changed, 42 insertions(+)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 2533933c79dc..0b8393ca8c80 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -302,6 +302,7 @@ static const struct net_device_ops sp_netdev_ops = {
 	.ndo_stop		= sp_close,
 	.ndo_start_xmit		= sp_xmit,
 	.ndo_set_mac_address    = sp_set_mac_address,
+	.ndo_neigh_construct	= ax25_neigh_construct,
 };
 
 static void sp_setup(struct net_device *dev)
@@ -315,6 +316,7 @@ static void sp_setup(struct net_device *dev)
 
 	dev->addr_len		= AX25_ADDR_LEN;
 	dev->type		= ARPHRD_AX25;
+	dev->neigh_priv_len	= sizeof(struct ax25_neigh_priv);
 	dev->tx_queue_len	= 10;
 
 	/* Only activated in AX.25 mode */
diff --git a/drivers/net/hamradio/baycom_epp.c b/drivers/net/hamradio/baycom_epp.c
index a98c153f371e..3539ab392f7d 100644
--- a/drivers/net/hamradio/baycom_epp.c
+++ b/drivers/net/hamradio/baycom_epp.c
@@ -1109,6 +1109,7 @@ static const struct net_device_ops baycom_netdev_ops = {
 	.ndo_do_ioctl	     = baycom_ioctl,
 	.ndo_start_xmit      = baycom_send_packet,
 	.ndo_set_mac_address = baycom_set_mac_address,
+	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 /*
@@ -1146,6 +1147,7 @@ static void baycom_probe(struct net_device *dev)
 	dev->header_ops = &ax25_header_ops;
 	
 	dev->type = ARPHRD_AX25;           /* AF_AX25 device */
+	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 	dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 	dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
diff --git a/drivers/net/hamradio/bpqether.c b/drivers/net/hamradio/bpqether.c
index c2894e43840e..bce105b16ed0 100644
--- a/drivers/net/hamradio/bpqether.c
+++ b/drivers/net/hamradio/bpqether.c
@@ -469,6 +469,7 @@ static const struct net_device_ops bpq_netdev_ops = {
 	.ndo_start_xmit	     = bpq_xmit,
 	.ndo_set_mac_address = bpq_set_mac_address,
 	.ndo_do_ioctl	     = bpq_ioctl,
+	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 static void bpq_setup(struct net_device *dev)
@@ -486,6 +487,7 @@ static void bpq_setup(struct net_device *dev)
 #endif
 
 	dev->type            = ARPHRD_AX25;
+	dev->neigh_priv_len  = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 	dev->mtu             = AX25_DEF_PACLEN;
 	dev->addr_len        = AX25_ADDR_LEN;
diff --git a/drivers/net/hamradio/dmascc.c b/drivers/net/hamradio/dmascc.c
index 0fad408f24aa..abab7be77406 100644
--- a/drivers/net/hamradio/dmascc.c
+++ b/drivers/net/hamradio/dmascc.c
@@ -433,6 +433,7 @@ module_exit(dmascc_exit);
 static void __init dev_setup(struct net_device *dev)
 {
 	dev->type = ARPHRD_AX25;
+	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN;
 	dev->mtu = 1500;
 	dev->addr_len = AX25_ADDR_LEN;
@@ -447,6 +448,7 @@ static const struct net_device_ops scc_netdev_ops = {
 	.ndo_start_xmit = scc_send_packet,
 	.ndo_do_ioctl = scc_ioctl,
 	.ndo_set_mac_address = scc_set_mac_address,
+	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 static int __init setup_adapter(int card_base, int type, int n)
diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
index c67a27245072..435868a7b69c 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -626,6 +626,7 @@ static const struct net_device_ops hdlcdrv_netdev = {
 	.ndo_start_xmit = hdlcdrv_send_packet,
 	.ndo_do_ioctl	= hdlcdrv_ioctl,
 	.ndo_set_mac_address = hdlcdrv_set_mac_address,
+	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 /*
@@ -676,6 +677,7 @@ static void hdlcdrv_setup(struct net_device *dev)
 	dev->header_ops = &ax25_header_ops;
 	
 	dev->type = ARPHRD_AX25;           /* AF_AX25 device */
+	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 	dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 	dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index e37c8d515ce8..c12ec2c2b594 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -641,6 +641,7 @@ static const struct net_device_ops ax_netdev_ops = {
 	.ndo_stop            = ax_close,
 	.ndo_start_xmit	     = ax_xmit,
 	.ndo_set_mac_address = ax_set_mac_address,
+	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 static void ax_setup(struct net_device *dev)
@@ -650,6 +651,7 @@ static void ax_setup(struct net_device *dev)
 	dev->hard_header_len = 0;
 	dev->addr_len        = 0;
 	dev->type            = ARPHRD_AX25;
+	dev->neigh_priv_len  = sizeof(struct ax25_neigh_priv);
 	dev->tx_queue_len    = 10;
 	dev->header_ops      = &ax25_header_ops;
 	dev->netdev_ops	     = &ax_netdev_ops;
diff --git a/drivers/net/hamradio/scc.c b/drivers/net/hamradio/scc.c
index 57be9e0e98a6..b305f51eb420 100644
--- a/drivers/net/hamradio/scc.c
+++ b/drivers/net/hamradio/scc.c
@@ -1550,6 +1550,7 @@ static const struct net_device_ops scc_netdev_ops = {
 	.ndo_set_mac_address = scc_net_set_mac_address,
 	.ndo_get_stats       = scc_net_get_stats,
 	.ndo_do_ioctl        = scc_net_ioctl,
+	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 /* ----> Initialize device <----- */
@@ -1567,6 +1568,7 @@ static void scc_net_setup(struct net_device *dev)
 	dev->flags      = 0;
 
 	dev->type = ARPHRD_AX25;
+	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 	dev->mtu = AX25_DEF_PACLEN;
 	dev->addr_len = AX25_ADDR_LEN;
diff --git a/drivers/net/hamradio/yam.c b/drivers/net/hamradio/yam.c
index 717433cfb81d..89d9da7a0c51 100644
--- a/drivers/net/hamradio/yam.c
+++ b/drivers/net/hamradio/yam.c
@@ -1100,6 +1100,7 @@ static const struct net_device_ops yam_netdev_ops = {
 	.ndo_start_xmit      = yam_send_packet,
 	.ndo_do_ioctl 	     = yam_ioctl,
 	.ndo_set_mac_address = yam_set_mac_address,
+	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 static void yam_setup(struct net_device *dev)
@@ -1128,6 +1129,7 @@ static void yam_setup(struct net_device *dev)
 	dev->header_ops = &ax25_header_ops;
 
 	dev->type = ARPHRD_AX25;
+	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN;
 	dev->mtu = AX25_MTU;
 	dev->addr_len = AX25_ADDR_LEN;
diff --git a/include/net/ax25.h b/include/net/ax25.h
index 7385a64b61b8..45feeba7a325 100644
--- a/include/net/ax25.h
+++ b/include/net/ax25.h
@@ -12,6 +12,7 @@
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/atomic.h>
+#include <net/neighbour.h>
 
 #define	AX25_T1CLAMPLO  		1
 #define	AX25_T1CLAMPHI 			(30 * HZ)
@@ -366,7 +367,11 @@ int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
 		  struct net_device *);
 
 /* ax25_ip.c */
+int ax25_neigh_construct(struct neighbour *neigh);
 extern const struct header_ops ax25_header_ops;
+struct ax25_neigh_priv {
+	struct neigh_ops ops;
+};
 
 /* ax25_out.c */
 ax25_cb *ax25_send_frame(struct sk_buff *, int, ax25_address *, ax25_address *,
diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index d93103ba8cec..bff12e0c9090 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -216,6 +216,22 @@ put:
 	return 1;
 }
 
+int ax25_neigh_construct(struct neighbour *neigh)
+{
+	/* This trouble could be saved if ax25 would right a proper
+	 * dev_queue_xmit function.
+	 */
+	struct ax25_neigh_priv *priv = neighbour_priv(neigh);
+
+	if (neigh->tbl->family != AF_INET)
+		return -EINVAL;
+
+	priv->ops = *neigh->ops;
+	priv->ops.output = neigh_compat_output;
+	priv->ops.connected_output = neigh_compat_output;
+	return 0;
+}
+
 #else	/* INET */
 
 static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
@@ -230,6 +246,10 @@ static int ax25_rebuild_header(struct sk_buff *skb)
 	return 1;
 }
 
+int ax25_neigh_construct(struct neighbour *neigh)
+{
+	return 0;
+}
 #endif
 
 const struct header_ops ax25_header_ops = {
@@ -238,4 +258,5 @@ const struct header_ops ax25_header_ops = {
 };
 
 EXPORT_SYMBOL(ax25_header_ops);
+EXPORT_SYMBOL(ax25_neigh_construct);
 
-- 
2.2.1

[PATCH net-next 08/15] arp: Remove special case to give AX25 it's open arp operations.

[Eric W. Biederman]

The special case has been pushed out into ax25_neigh_construct so there
is no need to keep this code in arp.c

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 net/ipv4/arp.c | 37 -------------------------------------
 1 file changed, 37 deletions(-)

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 205e1472aa78..2557cf9a4648 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -149,14 +149,6 @@ static const struct neigh_ops arp_direct_ops = {
 	.connected_output =	neigh_direct_output,
 };
 
-static const struct neigh_ops arp_broken_ops = {
-	.family =		AF_INET,
-	.solicit =		arp_solicit,
-	.error_report =		arp_error_report,
-	.output =		neigh_compat_output,
-	.connected_output =	neigh_compat_output,
-};
-
 struct neigh_table arp_tbl = {
 	.family		= AF_INET,
 	.key_len	= 4,
@@ -260,35 +252,6 @@ static int arp_constructor(struct neighbour *neigh)
 		   in old paradigm.
 		 */
 
-#if 1
-		/* So... these "amateur" devices are hopeless.
-		   The only thing, that I can say now:
-		   It is very sad that we need to keep ugly obsolete
-		   code to make them happy.
-
-		   They should be moved to more reasonable state, now
-		   they use rebuild_header INSTEAD OF hard_start_xmit!!!
-		   Besides that, they are sort of out of date
-		   (a lot of redundant clones/copies, useless in 2.1),
-		   I wonder why people believe that they work.
-		 */
-		switch (dev->type) {
-		default:
-			break;
-		case ARPHRD_ROSE:
-#if IS_ENABLED(CONFIG_AX25)
-		case ARPHRD_AX25:
-#if IS_ENABLED(CONFIG_NETROM)
-		case ARPHRD_NETROM:
-#endif
-			neigh->ops = &arp_broken_ops;
-			neigh->output = neigh->ops->output;
-			return 0;
-#else
-			break;
-#endif
-		}
-#endif
 		if (neigh->type == RTN_MULTICAST) {
 			neigh->nud_state = NUD_NOARP;
 			arp_mc_map(addr, neigh->ha, dev, 1);
-- 
2.2.1

[PATCH net-next 09/15] neigh: Move neigh_compat_output into ax25_ip.c

[Eric W. Biederman]

The only caller is now is ax25_neigh_construct so move
neigh_compat_output into ax25_ip.c make it static and rename it
ax25_neigh_output.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 include/net/neighbour.h |  1 -
 net/ax25/ax25_ip.c      | 18 ++++++++++++++++--
 net/core/neighbour.c    | 20 --------------------
 3 files changed, 16 insertions(+), 23 deletions(-)

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 76f708486aae..bc66babb5f27 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -268,7 +268,6 @@ void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
 int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
 int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
-int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb);
 int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);
 struct neighbour *neigh_event_ns(struct neigh_table *tbl,
 						u8 *lladdr, void *saddr,
diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index bff12e0c9090..cc7415b33cfb 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -216,6 +216,20 @@ put:
 	return 1;
 }
 
+static int ax25_neigh_output(struct neighbour *neigh, struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+
+	__skb_pull(skb, skb_network_offset(skb));
+
+	if (dev_hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
+			    skb->len) < 0 &&
+	    dev_rebuild_header(skb))
+		return 0;
+
+	return dev_queue_xmit(skb);
+}
+
 int ax25_neigh_construct(struct neighbour *neigh)
 {
 	/* This trouble could be saved if ax25 would right a proper
@@ -227,8 +241,8 @@ int ax25_neigh_construct(struct neighbour *neigh)
 		return -EINVAL;
 
 	priv->ops = *neigh->ops;
-	priv->ops.output = neigh_compat_output;
-	priv->ops.connected_output = neigh_compat_output;
+	priv->ops.output = ax25_neigh_output;
+	priv->ops.connected_output = ax25_neigh_output;
 	return 0;
 }
 
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 70fe9e10ac86..8a319ff3e8d1 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1280,26 +1280,6 @@ static void neigh_hh_init(struct neighbour *n, struct dst_entry *dst)
 	write_unlock_bh(&n->lock);
 }
 
-/* This function can be used in contexts, where only old dev_queue_xmit
- * worked, f.e. if you want to override normal output path (eql, shaper),
- * but resolution is not made yet.
- */
-
-int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb)
-{
-	struct net_device *dev = skb->dev;
-
-	__skb_pull(skb, skb_network_offset(skb));
-
-	if (dev_hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
-			    skb->len) < 0 &&
-	    dev_rebuild_header(skb))
-		return 0;
-
-	return dev_queue_xmit(skb);
-}
-EXPORT_SYMBOL(neigh_compat_output);
-
 /* Slow and careful. */
 
 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb)
-- 
2.2.1

[PATCH net-next 10/15] ax25: Stop calling/abusing dev_rebuild_header

[Eric W. Biederman]

- Rename ax25_rebuild_header to ax25_neigh_xmit and call it from
  ax25_neigh_output directly.  The rename is to make it clear
  that this is not a rebuild_header operation.

- Remove ax25_rebuild_header from ax25_header_ops.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 net/ax25/ax25_ip.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index cc7415b33cfb..08803e820f1d 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -100,7 +100,7 @@ static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
 	return -AX25_HEADER_LEN;	/* Unfinished header */
 }
 
-static int ax25_rebuild_header(struct sk_buff *skb)
+static int ax25_neigh_xmit(struct sk_buff *skb)
 {
 	struct sk_buff *ourskb;
 	unsigned char *bp  = skb->data;
@@ -224,7 +224,7 @@ static int ax25_neigh_output(struct neighbour *neigh, struct sk_buff *skb)
 
 	if (dev_hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
 			    skb->len) < 0 &&
-	    dev_rebuild_header(skb))
+	    ax25_neigh_xmit(skb));
 		return 0;
 
 	return dev_queue_xmit(skb);
@@ -255,11 +255,6 @@ static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
 	return -AX25_HEADER_LEN;
 }
 
-static int ax25_rebuild_header(struct sk_buff *skb)
-{
-	return 1;
-}
-
 int ax25_neigh_construct(struct neighbour *neigh)
 {
 	return 0;
@@ -268,7 +263,6 @@ int ax25_neigh_construct(struct neighbour *neigh)
 
 const struct header_ops ax25_header_ops = {
 	.create = ax25_hard_header,
-	.rebuild = ax25_rebuild_header,
 };
 
 EXPORT_SYMBOL(ax25_header_ops);
-- 
2.2.1

[PATCH net-next 11/15] ax25: Stop depending on arp_find

[Eric W. Biederman]

Have ax25_neigh_output perform ordinary arp resolution before calling
ax25_neigh_xmit.

Call dev_hard_header in ax25_neigh_output with a destination address so
it will not fail, and the destination mac address will not need to be
set in ax25_neigh_xmit.

Remove arp_find from ax25_neigh_xmit (the ordinary arp resolution added
to ax25_neigh_output removes the need for calling arp_find).

Document how close ax25_neigh_output is to neigh_resolve_output.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 net/ax25/ax25_ip.c | 40 ++++++++++++++++++++++++++++------------
 1 file changed, 28 insertions(+), 12 deletions(-)

diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index 08803e820f1d..e030c64ebfb7 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -115,9 +115,6 @@ static int ax25_neigh_xmit(struct sk_buff *skb)
 	dst = (ax25_address *)(bp + 1);
 	src = (ax25_address *)(bp + 8);
 
-	if (arp_find(bp + 1, skb))
-		return 1;
-
 	route = ax25_get_route(dst, NULL);
 	if (route) {
 		digipeat = route->digipeat;
@@ -218,16 +215,35 @@ put:
 
 static int ax25_neigh_output(struct neighbour *neigh, struct sk_buff *skb)
 {
-	struct net_device *dev = skb->dev;
-
-	__skb_pull(skb, skb_network_offset(skb));
-
-	if (dev_hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
-			    skb->len) < 0 &&
-	    ax25_neigh_xmit(skb));
-		return 0;
+	/* Except for calling ax25_neigh_xmit instead of
+	 * dev_queue_xmit this is neigh_resolve_output.
+	 */
+	int rc = 0;
+
+	if (!neigh_event_send(neigh, skb)) {
+		int err;
+		struct net_device *dev = neigh->dev;
+		unsigned int seq;
+
+		do {
+			__skb_pull(skb, skb_network_offset(skb));
+			seq = read_seqbegin(&neigh->ha_lock);
+			err = dev_hard_header(skb, dev, ntohs(skb->protocol),
+					      neigh->ha, NULL, skb->len);
+		} while (read_seqretry(&neigh->ha_lock, seq));
+
+		if (err >= 0) {
+			ax25_neigh_xmit(skb);
+		} else
+			goto out_kfree_skb;
+	}
+out:
+	return rc;
 
-	return dev_queue_xmit(skb);
+out_kfree_skb:
+	rc = -EINVAL;
+	kfree_skb(skb);
+	goto out;
 }
 
 int ax25_neigh_construct(struct neighbour *neigh)
-- 
2.2.1

[PATCH net-next 12/15] net: Kill dev_rebuild_header

[Eric W. Biederman]

Now that there are no more users kill dev_rebuild_header and all of it's
implementations.

This is long overdue.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 drivers/firewire/net.c                    | 13 --------
 drivers/isdn/i4l/isdn_net.c               | 33 -------------------
 drivers/media/dvb-core/dvb_net.c          |  1 -
 drivers/net/arcnet/arcnet.c               | 55 -------------------------------
 drivers/net/ipvlan/ipvlan_main.c          |  1 -
 drivers/net/macvlan.c                     |  1 -
 drivers/net/wireless/hostap/hostap_main.c |  1 -
 include/linux/etherdevice.h               |  1 -
 include/linux/netdevice.h                 | 12 +------
 net/802/fc.c                              | 21 ------------
 net/802/fddi.c                            | 26 ---------------
 net/802/hippi.c                           | 28 ----------------
 net/8021q/vlan_dev.c                      | 35 --------------------
 net/ethernet/eth.c                        | 34 -------------------
 net/netrom/nr_dev.c                       | 31 -----------------
 net/rose/rose_dev.c                       | 14 --------
 16 files changed, 1 insertion(+), 306 deletions(-)

diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
index 2c68da1ceeee..f4ea80d602f7 100644
--- a/drivers/firewire/net.c
+++ b/drivers/firewire/net.c
@@ -237,18 +237,6 @@ static int fwnet_header_create(struct sk_buff *skb, struct net_device *net,
 	return -net->hard_header_len;
 }
 
-static int fwnet_header_rebuild(struct sk_buff *skb)
-{
-	struct fwnet_header *h = (struct fwnet_header *)skb->data;
-
-	if (get_unaligned_be16(&h->h_proto) == ETH_P_IP)
-		return arp_find((unsigned char *)&h->h_dest, skb);
-
-	dev_notice(&skb->dev->dev, "unable to resolve type %04x addresses\n",
-		   be16_to_cpu(h->h_proto));
-	return 0;
-}
-
 static int fwnet_header_cache(const struct neighbour *neigh,
 			      struct hh_cache *hh, __be16 type)
 {
@@ -282,7 +270,6 @@ static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr)
 
 static const struct header_ops fwnet_header_ops = {
 	.create         = fwnet_header_create,
-	.rebuild        = fwnet_header_rebuild,
 	.cache		= fwnet_header_cache,
 	.cache_update	= fwnet_header_cache_update,
 	.parse          = fwnet_header_parse,
diff --git a/drivers/isdn/i4l/isdn_net.c b/drivers/isdn/i4l/isdn_net.c
index 94affa5e6f28..546b7e81161d 100644
--- a/drivers/isdn/i4l/isdn_net.c
+++ b/drivers/isdn/i4l/isdn_net.c
@@ -1951,38 +1951,6 @@ static int isdn_net_header(struct sk_buff *skb, struct net_device *dev,
 	return len;
 }
 
-/* We don't need to send arp, because we have point-to-point connections. */
-static int
-isdn_net_rebuild_header(struct sk_buff *skb)
-{
-	struct net_device *dev = skb->dev;
-	isdn_net_local *lp = netdev_priv(dev);
-	int ret = 0;
-
-	if (lp->p_encap == ISDN_NET_ENCAP_ETHER) {
-		struct ethhdr *eth = (struct ethhdr *) skb->data;
-
-		/*
-		 *      Only ARP/IP is currently supported
-		 */
-
-		if (eth->h_proto != htons(ETH_P_IP)) {
-			printk(KERN_WARNING
-			       "isdn_net: %s don't know how to resolve type %d addresses?\n",
-			       dev->name, (int) eth->h_proto);
-			memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
-			return 0;
-		}
-		/*
-		 *      Try to get ARP to resolve the header.
-		 */
-#ifdef CONFIG_INET
-		ret = arp_find(eth->h_dest, skb);
-#endif
-	}
-	return ret;
-}
-
 static int isdn_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
 			     __be16 type)
 {
@@ -2005,7 +1973,6 @@ static void isdn_header_cache_update(struct hh_cache *hh,
 
 static const struct header_ops isdn_header_ops = {
 	.create = isdn_net_header,
-	.rebuild = isdn_net_rebuild_header,
 	.cache = isdn_header_cache,
 	.cache_update = isdn_header_cache_update,
 };
diff --git a/drivers/media/dvb-core/dvb_net.c b/drivers/media/dvb-core/dvb_net.c
index 686d3277dad1..4a77cb02dffc 100644
--- a/drivers/media/dvb-core/dvb_net.c
+++ b/drivers/media/dvb-core/dvb_net.c
@@ -1190,7 +1190,6 @@ static int dvb_net_stop(struct net_device *dev)
 static const struct header_ops dvb_header_ops = {
 	.create		= eth_header,
 	.parse		= eth_header_parse,
-	.rebuild	= eth_rebuild_header,
 };
 
 
diff --git a/drivers/net/arcnet/arcnet.c b/drivers/net/arcnet/arcnet.c
index 09de683c167e..10f71c732b59 100644
--- a/drivers/net/arcnet/arcnet.c
+++ b/drivers/net/arcnet/arcnet.c
@@ -104,7 +104,6 @@ EXPORT_SYMBOL(arcnet_timeout);
 static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
 			 unsigned short type, const void *daddr,
 			 const void *saddr, unsigned len);
-static int arcnet_rebuild_header(struct sk_buff *skb);
 static int go_tx(struct net_device *dev);
 
 static int debug = ARCNET_DEBUG;
@@ -312,7 +311,6 @@ static int choose_mtu(void)
 
 static const struct header_ops arcnet_header_ops = {
 	.create = arcnet_header,
-	.rebuild = arcnet_rebuild_header,
 };
 
 static const struct net_device_ops arcnet_netdev_ops = {
@@ -538,59 +536,6 @@ static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
 	return proto->build_header(skb, dev, type, _daddr);
 }
 
-
-/* 
- * Rebuild the ARCnet hard header. This is called after an ARP (or in the
- * future other address resolution) has completed on this sk_buff. We now
- * let ARP fill in the destination field.
- */
-static int arcnet_rebuild_header(struct sk_buff *skb)
-{
-	struct net_device *dev = skb->dev;
-	struct arcnet_local *lp = netdev_priv(dev);
-	int status = 0;		/* default is failure */
-	unsigned short type;
-	uint8_t daddr=0;
-	struct ArcProto *proto;
-	/*
-	 * XXX: Why not use skb->mac_len?
-	 */
-	if (skb->network_header - skb->mac_header != 2) {
-		BUGMSG(D_NORMAL,
-		       "rebuild_header: shouldn't be here! (hdrsize=%d)\n",
-		       (int)(skb->network_header - skb->mac_header));
-		return 0;
-	}
-	type = *(uint16_t *) skb_pull(skb, 2);
-	BUGMSG(D_DURING, "rebuild header for protocol %Xh\n", type);
-
-	if (type == ETH_P_IP) {
-#ifdef CONFIG_INET
-		BUGMSG(D_DURING, "rebuild header for ethernet protocol %Xh\n", type);
-		status = arp_find(&daddr, skb) ? 1 : 0;
-		BUGMSG(D_DURING, " rebuilt: dest is %d; protocol %Xh\n",
-		       daddr, type);
-#endif
-	} else {
-		BUGMSG(D_NORMAL,
-		       "I don't understand ethernet protocol %Xh addresses!\n", type);
-		dev->stats.tx_errors++;
-		dev->stats.tx_aborted_errors++;
-	}
-
-	/* if we couldn't resolve the address... give up. */
-	if (!status)
-		return 0;
-
-	/* add the _real_ header this time! */
-	proto = arc_proto_map[lp->default_proto[daddr]];
-	proto->build_header(skb, dev, type, daddr);
-
-	return 1;		/* success */
-}
-
-
-
 /* Called by the kernel in order to transmit a packet. */
 netdev_tx_t arcnet_send_packet(struct sk_buff *skb,
 				     struct net_device *dev)
diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 4f4099d5603d..2950c3780230 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -336,7 +336,6 @@ static int ipvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
 
 static const struct header_ops ipvlan_header_ops = {
 	.create  	= ipvlan_hard_header,
-	.rebuild	= eth_rebuild_header,
 	.parse		= eth_header_parse,
 	.cache		= eth_header_cache,
 	.cache_update	= eth_header_cache_update,
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 1df38bdae2ee..b5e3320ca506 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -550,7 +550,6 @@ static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
 
 static const struct header_ops macvlan_hard_header_ops = {
 	.create  	= macvlan_hard_header,
-	.rebuild	= eth_rebuild_header,
 	.parse		= eth_header_parse,
 	.cache		= eth_header_cache,
 	.cache_update	= eth_header_cache_update,
diff --git a/drivers/net/wireless/hostap/hostap_main.c b/drivers/net/wireless/hostap/hostap_main.c
index 52919ad42726..8f9f3e9fbfce 100644
--- a/drivers/net/wireless/hostap/hostap_main.c
+++ b/drivers/net/wireless/hostap/hostap_main.c
@@ -798,7 +798,6 @@ static void prism2_tx_timeout(struct net_device *dev)
 
 const struct header_ops hostap_80211_ops = {
 	.create		= eth_header,
-	.rebuild	= eth_rebuild_header,
 	.cache		= eth_header_cache,
 	.cache_update	= eth_header_cache_update,
 	.parse		= hostap_80211_header_parse,
diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index 1d869d185a0d..606563ef8a72 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -35,7 +35,6 @@ extern const struct header_ops eth_header_ops;
 
 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
 	       const void *daddr, const void *saddr, unsigned len);
-int eth_rebuild_header(struct sk_buff *skb);
 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
 		     __be16 type);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 5897b4ea5a3f..2007f3b44d05 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -261,7 +261,6 @@ struct header_ops {
 			   unsigned short type, const void *daddr,
 			   const void *saddr, unsigned int len);
 	int	(*parse)(const struct sk_buff *skb, unsigned char *haddr);
-	int	(*rebuild)(struct sk_buff *skb);
 	int	(*cache)(const struct neighbour *neigh, struct hh_cache *hh, __be16 type);
 	void	(*cache_update)(struct hh_cache *hh,
 				const struct net_device *dev,
@@ -1346,7 +1345,7 @@ enum netdev_priv_flags {
  *			if one wants to override the ndo_*() functions
  *	@ethtool_ops:	Management operations
  *	@fwd_ops:	Management operations
- *	@header_ops:	Includes callbacks for creating,parsing,rebuilding,etc
+ *	@header_ops:	Includes callbacks for creating,parsing,caching,etc
  *			of Layer 2 headers.
  *
  *	@flags:		Interface flags (a la BSD)
@@ -2399,15 +2398,6 @@ static inline int dev_parse_header(const struct sk_buff *skb,
 	return dev->header_ops->parse(skb, haddr);
 }
 
-static inline int dev_rebuild_header(struct sk_buff *skb)
-{
-	const struct net_device *dev = skb->dev;
-
-	if (!dev->header_ops || !dev->header_ops->rebuild)
-		return 0;
-	return dev->header_ops->rebuild(skb);
-}
-
 typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr, int len);
 int register_gifconf(unsigned int family, gifconf_func_t *gifconf);
 static inline int unregister_gifconf(unsigned int family)
diff --git a/net/802/fc.c b/net/802/fc.c
index 7c174b6750cd..7b9219022418 100644
--- a/net/802/fc.c
+++ b/net/802/fc.c
@@ -75,29 +75,8 @@ static int fc_header(struct sk_buff *skb, struct net_device *dev,
 	return -hdr_len;
 }
 
-/*
- *	A neighbour discovery of some species (eg arp) has completed. We
- *	can now send the packet.
- */
-
-static int fc_rebuild_header(struct sk_buff *skb)
-{
-#ifdef CONFIG_INET
-	struct fch_hdr *fch=(struct fch_hdr *)skb->data;
-	struct fcllc *fcllc=(struct fcllc *)(skb->data+sizeof(struct fch_hdr));
-	if(fcllc->ethertype != htons(ETH_P_IP)) {
-		printk("fc_rebuild_header: Don't know how to resolve type %04X addresses ?\n", ntohs(fcllc->ethertype));
-		return 0;
-	}
-	return arp_find(fch->daddr, skb);
-#else
-	return 0;
-#endif
-}
-
 static const struct header_ops fc_header_ops = {
 	.create	 = fc_header,
-	.rebuild = fc_rebuild_header,
 };
 
 static void fc_setup(struct net_device *dev)
diff --git a/net/802/fddi.c b/net/802/fddi.c
index 59e7346f1193..7d3a0af954e8 100644
--- a/net/802/fddi.c
+++ b/net/802/fddi.c
@@ -87,31 +87,6 @@ static int fddi_header(struct sk_buff *skb, struct net_device *dev,
 	return -hl;
 }
 
-
-/*
- * Rebuild the FDDI MAC header. This is called after an ARP
- * (or in future other address resolution) has completed on
- * this sk_buff.  We now let ARP fill in the other fields.
- */
-
-static int fddi_rebuild_header(struct sk_buff	*skb)
-{
-	struct fddihdr *fddi = (struct fddihdr *)skb->data;
-
-#ifdef CONFIG_INET
-	if (fddi->hdr.llc_snap.ethertype == htons(ETH_P_IP))
-		/* Try to get ARP to resolve the header and fill destination address */
-		return arp_find(fddi->daddr, skb);
-	else
-#endif
-	{
-		printk("%s: Don't know how to resolve type %04X addresses.\n",
-		       skb->dev->name, ntohs(fddi->hdr.llc_snap.ethertype));
-		return 0;
-	}
-}
-
-
 /*
  * Determine the packet's protocol ID and fill in skb fields.
  * This routine is called before an incoming packet is passed
@@ -177,7 +152,6 @@ EXPORT_SYMBOL(fddi_change_mtu);
 
 static const struct header_ops fddi_header_ops = {
 	.create		= fddi_header,
-	.rebuild	= fddi_rebuild_header,
 };
 
 
diff --git a/net/802/hippi.c b/net/802/hippi.c
index 2e03f8259dd5..ade1a52cdcff 100644
--- a/net/802/hippi.c
+++ b/net/802/hippi.c
@@ -91,33 +91,6 @@ static int hippi_header(struct sk_buff *skb, struct net_device *dev,
 
 
 /*
- * Rebuild the HIPPI MAC header. This is called after an ARP has
- * completed on this sk_buff. We now let ARP fill in the other fields.
- */
-
-static int hippi_rebuild_header(struct sk_buff *skb)
-{
-	struct hippi_hdr *hip = (struct hippi_hdr *)skb->data;
-
-	/*
-	 * Only IP is currently supported
-	 */
-
-	if(hip->snap.ethertype != htons(ETH_P_IP))
-	{
-		printk(KERN_DEBUG "%s: unable to resolve type %X addresses.\n",skb->dev->name,ntohs(hip->snap.ethertype));
-		return 0;
-	}
-
-	/*
-	 * We don't support dynamic ARP on HIPPI, but we use the ARP
-	 * static ARP tables to hold the I-FIELDs.
-	 */
-	return arp_find(hip->le.daddr, skb);
-}
-
-
-/*
  *	Determine the packet's protocol ID.
  */
 
@@ -186,7 +159,6 @@ EXPORT_SYMBOL(hippi_neigh_setup_dev);
 
 static const struct header_ops hippi_header_ops = {
 	.create		= hippi_header,
-	.rebuild	= hippi_rebuild_header,
 };
 
 
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 118956448cf6..1dcfec8b49f3 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -37,39 +37,6 @@
 #include <linux/netpoll.h>
 
 /*
- *	Rebuild the Ethernet MAC header. This is called after an ARP
- *	(or in future other address resolution) has completed on this
- *	sk_buff. We now let ARP fill in the other fields.
- *
- *	This routine CANNOT use cached dst->neigh!
- *	Really, it is used only when dst->neigh is wrong.
- *
- * TODO:  This needs a checkup, I'm ignorant here. --BLG
- */
-static int vlan_dev_rebuild_header(struct sk_buff *skb)
-{
-	struct net_device *dev = skb->dev;
-	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);
-
-	switch (veth->h_vlan_encapsulated_proto) {
-#ifdef CONFIG_INET
-	case htons(ETH_P_IP):
-
-		/* TODO:  Confirm this will work with VLAN headers... */
-		return arp_find(veth->h_dest, skb);
-#endif
-	default:
-		pr_debug("%s: unable to resolve type %X addresses\n",
-			 dev->name, ntohs(veth->h_vlan_encapsulated_proto));
-
-		ether_addr_copy(veth->h_source, dev->dev_addr);
-		break;
-	}
-
-	return 0;
-}
-
-/*
  *	Create the VLAN header for an arbitrary protocol layer
  *
  *	saddr=NULL	means use device source address
@@ -534,7 +501,6 @@ static int vlan_dev_get_lock_subclass(struct net_device *dev)
 
 static const struct header_ops vlan_header_ops = {
 	.create	 = vlan_dev_hard_header,
-	.rebuild = vlan_dev_rebuild_header,
 	.parse	 = eth_header_parse,
 };
 
@@ -554,7 +520,6 @@ static int vlan_passthru_hard_header(struct sk_buff *skb, struct net_device *dev
 
 static const struct header_ops vlan_passthru_header_ops = {
 	.create	 = vlan_passthru_hard_header,
-	.rebuild = dev_rebuild_header,
 	.parse	 = eth_header_parse,
 };
 
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 238f38d21641..8dbdf6c910b7 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -113,39 +113,6 @@ int eth_header(struct sk_buff *skb, struct net_device *dev,
 EXPORT_SYMBOL(eth_header);
 
 /**
- * eth_rebuild_header- rebuild the Ethernet MAC header.
- * @skb: socket buffer to update
- *
- * This is called after an ARP or IPV6 ndisc it's resolution on this
- * sk_buff. We now let protocol (ARP) fill in the other fields.
- *
- * This routine CANNOT use cached dst->neigh!
- * Really, it is used only when dst->neigh is wrong.
- */
-int eth_rebuild_header(struct sk_buff *skb)
-{
-	struct ethhdr *eth = (struct ethhdr *)skb->data;
-	struct net_device *dev = skb->dev;
-
-	switch (eth->h_proto) {
-#ifdef CONFIG_INET
-	case htons(ETH_P_IP):
-		return arp_find(eth->h_dest, skb);
-#endif
-	default:
-		netdev_dbg(dev,
-		       "%s: unable to resolve type %X addresses.\n",
-		       dev->name, ntohs(eth->h_proto));
-
-		memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
-		break;
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL(eth_rebuild_header);
-
-/**
  * eth_get_headlen - determine the the length of header for an ethernet frame
  * @data: pointer to start of frame
  * @len: total length of frame
@@ -369,7 +336,6 @@ EXPORT_SYMBOL(eth_validate_addr);
 const struct header_ops eth_header_ops ____cacheline_aligned = {
 	.create		= eth_header,
 	.parse		= eth_header_parse,
-	.rebuild	= eth_rebuild_header,
 	.cache		= eth_header_cache,
 	.cache_update	= eth_header_cache_update,
 };
diff --git a/net/netrom/nr_dev.c b/net/netrom/nr_dev.c
index 6ae063cebf7d..988f542481a8 100644
--- a/net/netrom/nr_dev.c
+++ b/net/netrom/nr_dev.c
@@ -65,36 +65,6 @@ int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
 	return 1;
 }
 
-#ifdef CONFIG_INET
-
-static int nr_rebuild_header(struct sk_buff *skb)
-{
-	unsigned char *bp = skb->data;
-
-	if (arp_find(bp + 7, skb))
-		return 1;
-
-	bp[6] &= ~AX25_CBIT;
-	bp[6] &= ~AX25_EBIT;
-	bp[6] |= AX25_SSSID_SPARE;
-	bp    += AX25_ADDR_LEN;
-
-	bp[6] &= ~AX25_CBIT;
-	bp[6] |= AX25_EBIT;
-	bp[6] |= AX25_SSSID_SPARE;
-
-	return 0;
-}
-
-#else
-
-static int nr_rebuild_header(struct sk_buff *skb)
-{
-	return 1;
-}
-
-#endif
-
 static int nr_header(struct sk_buff *skb, struct net_device *dev,
 		     unsigned short type,
 		     const void *daddr, const void *saddr, unsigned int len)
@@ -188,7 +158,6 @@ static netdev_tx_t nr_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static const struct header_ops nr_header_ops = {
 	.create	= nr_header,
-	.rebuild= nr_rebuild_header,
 };
 
 static const struct net_device_ops nr_netdev_ops = {
diff --git a/net/rose/rose_dev.c b/net/rose/rose_dev.c
index 90209c1fa49b..369ca81a8c5d 100644
--- a/net/rose/rose_dev.c
+++ b/net/rose/rose_dev.c
@@ -56,19 +56,6 @@ static int rose_header(struct sk_buff *skb, struct net_device *dev,
 	return -37;
 }
 
-static int rose_rebuild_header(struct sk_buff *skb)
-{
-#ifdef CONFIG_INET
-	unsigned char *bp = (unsigned char *)skb->data;
-
-	if (arp_find(bp + 7, skb)) {
-		return 1;
-	}
-
-#endif
-	return 0;
-}
-
 static int rose_set_mac_address(struct net_device *dev, void *addr)
 {
 	struct sockaddr *sa = addr;
@@ -133,7 +120,6 @@ static netdev_tx_t rose_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static const struct header_ops rose_header_ops = {
 	.create	= rose_header,
-	.rebuild = rose_rebuild_header,
 };
 
 static const struct net_device_ops rose_netdev_ops = {
-- 
2.2.1

[PATCH net-next 13/15] arp: Kill arp_find

[Eric W. Biederman]

There are no more callers so kill this function.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 include/net/arp.h |  1 -
 net/ipv4/arp.c    | 65 -------------------------------------------------------
 2 files changed, 66 deletions(-)

diff --git a/include/net/arp.h b/include/net/arp.h
index 73c49864076b..21ee1860abbc 100644
--- a/include/net/arp.h
+++ b/include/net/arp.h
@@ -47,7 +47,6 @@ static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32
 }
 
 void arp_init(void);
-int arp_find(unsigned char *haddr, struct sk_buff *skb);
 int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg);
 void arp_send(int type, int ptype, __be32 dest_ip,
 	      struct net_device *dev, __be32 src_ip,
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 2557cf9a4648..bca5b9d9b442 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -396,71 +396,6 @@ static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
 	return flag;
 }
 
-/* OBSOLETE FUNCTIONS */
-
-/*
- *	Find an arp mapping in the cache. If not found, post a request.
- *
- *	It is very UGLY routine: it DOES NOT use skb->dst->neighbour,
- *	even if it exists. It is supposed that skb->dev was mangled
- *	by a virtual device (eql, shaper). Nobody but broken devices
- *	is allowed to use this function, it is scheduled to be removed. --ANK
- */
-
-static int arp_set_predefined(int addr_hint, unsigned char *haddr,
-			      __be32 paddr, struct net_device *dev)
-{
-	switch (addr_hint) {
-	case RTN_LOCAL:
-		pr_debug("arp called for own IP address\n");
-		memcpy(haddr, dev->dev_addr, dev->addr_len);
-		return 1;
-	case RTN_MULTICAST:
-		arp_mc_map(paddr, haddr, dev, 1);
-		return 1;
-	case RTN_BROADCAST:
-		memcpy(haddr, dev->broadcast, dev->addr_len);
-		return 1;
-	}
-	return 0;
-}
-
-
-int arp_find(unsigned char *haddr, struct sk_buff *skb)
-{
-	struct net_device *dev = skb->dev;
-	__be32 paddr;
-	struct neighbour *n;
-
-	if (!skb_dst(skb)) {
-		pr_debug("arp_find is called with dst==NULL\n");
-		kfree_skb(skb);
-		return 1;
-	}
-
-	paddr = rt_nexthop(skb_rtable(skb), ip_hdr(skb)->daddr);
-	if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr,
-			       paddr, dev))
-		return 0;
-
-	n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);
-
-	if (n) {
-		n->used = jiffies;
-		if (n->nud_state & NUD_VALID || neigh_event_send(n, skb) == 0) {
-			neigh_ha_snapshot(haddr, n, dev);
-			neigh_release(n);
-			return 0;
-		}
-		neigh_release(n);
-	} else
-		kfree_skb(skb);
-	return 1;
-}
-EXPORT_SYMBOL(arp_find);
-
-/* END OF OBSOLETE FUNCTIONS */
-
 /*
  * Check if we can use proxy ARP for this path
  */
-- 
2.2.1

[PATCH net-next 14/15] neigh: Don't require dst in neigh_hh_init

[Eric W. Biederman]

- Add protocol to neigh_tbl so that dst->ops->protocol is not needed
- Acquire the device from neigh->dev

This results in a neigh_hh_init that will cache the samve values
regardless of the packets flowing through it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 include/net/neighbour.h | 1 +
 net/core/neighbour.c    | 8 ++++----
 net/decnet/dn_neigh.c   | 1 +
 net/ipv4/arp.c          | 1 +
 net/ipv6/ndisc.c        | 1 +
 5 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index bc66babb5f27..9f912e4d4232 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -193,6 +193,7 @@ struct neigh_table {
 	int			family;
 	int			entry_size;
 	int			key_len;
+	__be16			protocol;
 	__u32			(*hash)(const void *pkey,
 					const struct net_device *dev,
 					__u32 *hash_rnd);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 8a319ff3e8d1..af72b863e968 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1263,10 +1263,10 @@ struct neighbour *neigh_event_ns(struct neigh_table *tbl,
 EXPORT_SYMBOL(neigh_event_ns);
 
 /* called with read_lock_bh(&n->lock); */
-static void neigh_hh_init(struct neighbour *n, struct dst_entry *dst)
+static void neigh_hh_init(struct neighbour *n)
 {
-	struct net_device *dev = dst->dev;
-	__be16 prot = dst->ops->protocol;
+	struct net_device *dev = n->dev;
+	__be16 prot = n->tbl->protocol;
 	struct hh_cache	*hh = &n->hh;
 
 	write_lock_bh(&n->lock);
@@ -1296,7 +1296,7 @@ int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb)
 		unsigned int seq;
 
 		if (dev->header_ops->cache && !neigh->hh.hh_len)
-			neigh_hh_init(neigh, dst);
+			neigh_hh_init(neigh);
 
 		do {
 			__skb_pull(skb, skb_network_offset(skb));
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index 7ca7c3143da3..f123c6c6748c 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -97,6 +97,7 @@ struct neigh_table dn_neigh_table = {
 	.family =			PF_DECnet,
 	.entry_size =			NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
 	.key_len =			sizeof(__le16),
+	.protocol =			cpu_to_be16(ETH_P_DNA_RT),
 	.hash =				dn_neigh_hash,
 	.constructor =			dn_neigh_construct,
 	.id =				"dn_neigh_cache",
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index bca5b9d9b442..6b8aad6a0d7d 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -152,6 +152,7 @@ static const struct neigh_ops arp_direct_ops = {
 struct neigh_table arp_tbl = {
 	.family		= AF_INET,
 	.key_len	= 4,
+	.protocol	= cpu_to_be16(ETH_P_IP),
 	.hash		= arp_hash,
 	.constructor	= arp_constructor,
 	.proxy_redo	= parp_redo,
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 471ed24aabae..e363bbc2420d 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -117,6 +117,7 @@ static const struct neigh_ops ndisc_direct_ops = {
 struct neigh_table nd_tbl = {
 	.family =	AF_INET6,
 	.key_len =	sizeof(struct in6_addr),
+	.protocol =	cpu_to_be16(ETH_P_IPV6),
 	.hash =		ndisc_hash,
 	.constructor =	ndisc_constructor,
 	.pconstructor =	pndisc_constructor,
-- 
2.2.1

[PATCH net-next 15/15] neigh: Don't require a dst in neigh_resolve_output

[Eric W. Biederman]

Having a dst helps a little bit for teql but is fundamentally
unnecessary and there are code paths where a dst is not available that
it would be nice to use the neighbour cache.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 net/core/neighbour.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index af72b863e968..0f48ea3affed 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1284,12 +1284,8 @@ static void neigh_hh_init(struct neighbour *n)
 
 int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb)
 {
-	struct dst_entry *dst = skb_dst(skb);
 	int rc = 0;
 
-	if (!dst)
-		goto discard;
-
 	if (!neigh_event_send(neigh, skb)) {
 		int err;
 		struct net_device *dev = neigh->dev;
@@ -1312,8 +1308,6 @@ int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb)
 	}
 out:
 	return rc;
-discard:
-	neigh_dbg(1, "%s: dst=%p neigh=%p\n", __func__, dst, neigh);
 out_kfree_skb:
 	rc = -EINVAL;
 	kfree_skb(skb);
-- 
2.2.1

Re: [PATCH net-next 0/15] Neighbour table and ax25 cleanups

[David Miller]

From: ebiederm@xmission.com (Eric W. Biederman)
Date: Sun, 01 Mar 2015 23:59:11 -0600

> While looking at the neighbour table to what it would take to allow
> using next hops in a different address family than the current packets
> I found a partial resolution for my issues and I stumbled upon some
> work that makes the neighbour table code easier to understand and
> maintain.
> 
> Long ago in a much younger kernel ax25 found a hack to use
> dev_rebuild_header to transmit it's packets instead of going through
> what today is ndo_start_xmit.
> 
> When the neighbour table was rewritten into it's current form the ax25
> code was such a challenge that arp_broken_ops appeard in arp.c and
> neigh_compat_output appeared in neighbour.c to keep the ax25 hack alive.
> 
> With a little bit of work I was able to remove some of the hack that
> is the ax25 transmit path for ip packets and to isolate what remains
> into a slightly more readable piece of code in ax25_ip.c.  Removing the
> need for the generic code to worry about ax25 special cases.
> 
> After cleaning up the old ax25 hacks I also performed a little bit of
> work on neigh_resolve_output to remove the need for a dst entry and to
> ensure cached headers get a deterministic protocol value in their cached
> header.   This guarantees that a cached header will not be different
> depending on which protocol of packet is transmitted, and it allows
> packets to be transmitted that don't have a dst entry.  There remains
> a small amount of code that takes advantage of when packets have a dst
> entry but that is something different.

Wow... simply, wow.

I thought we'd be stuck with that crap forever, great work!

Applied to net-next, thanks again!

[PATCH net-next] ax25: Stop using magic neighbour cache operations.

[Eric W. Biederman]

Before the ax25 stack calls dev_queue_xmit it always calls
ax25_type_trans which sets skb->protocol to ETH_P_AX25.

Which means that by looking at the protocol type it is possible to
detect IP packets that have not been munged by the ax25 stack in
ndo_start_xmit and call a function to munge them.

Rename ax25_neigh_xmit to ax25_ip_xmit and tweak the return type and
value to be appropriate for an ndo_start_xmit function.

Update all of the ax25 devices to test the protocol type for ETH_P_IP
and return ax25_ip_xmit as the first thing they do.  This preserves
the existing semantics of IP packet processing, but the timing will be
a little different as the IP packets now pass through the qdisc layer
before reaching the ax25 ip packet processing.

Remove the now unnecessary ax25 neighbour table operations.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 drivers/net/hamradio/6pack.c      |  5 ++--
 drivers/net/hamradio/baycom_epp.c |  5 ++--
 drivers/net/hamradio/bpqether.c   |  5 ++--
 drivers/net/hamradio/dmascc.c     |  5 ++--
 drivers/net/hamradio/hdlcdrv.c    |  5 ++--
 drivers/net/hamradio/mkiss.c      |  5 ++--
 drivers/net/hamradio/scc.c        |  5 ++--
 drivers/net/hamradio/yam.c        |  5 ++--
 include/net/ax25.h                |  5 +---
 net/ax25/ax25_ip.c                | 60 ++++-----------------------------------
 10 files changed, 31 insertions(+), 74 deletions(-)

diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 0b8393ca8c80..7c4a4151ef0f 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -247,6 +247,9 @@ static netdev_tx_t sp_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct sixpack *sp = netdev_priv(dev);
 
+	if (skb->protocol == htons(ETH_P_IP))
+		return ax25_ip_xmit(skb);
+
 	spin_lock_bh(&sp->lock);
 	/* We were not busy, so we are now... :-) */
 	netif_stop_queue(dev);
@@ -302,7 +305,6 @@ static const struct net_device_ops sp_netdev_ops = {
 	.ndo_stop		= sp_close,
 	.ndo_start_xmit		= sp_xmit,
 	.ndo_set_mac_address    = sp_set_mac_address,
-	.ndo_neigh_construct	= ax25_neigh_construct,
 };
 
 static void sp_setup(struct net_device *dev)
@@ -316,7 +318,6 @@ static void sp_setup(struct net_device *dev)
 
 	dev->addr_len		= AX25_ADDR_LEN;
 	dev->type		= ARPHRD_AX25;
-	dev->neigh_priv_len	= sizeof(struct ax25_neigh_priv);
 	dev->tx_queue_len	= 10;
 
 	/* Only activated in AX.25 mode */
diff --git a/drivers/net/hamradio/baycom_epp.c b/drivers/net/hamradio/baycom_epp.c
index 3539ab392f7d..83c7cce0d172 100644
--- a/drivers/net/hamradio/baycom_epp.c
+++ b/drivers/net/hamradio/baycom_epp.c
@@ -772,6 +772,9 @@ static int baycom_send_packet(struct sk_buff *skb, struct net_device *dev)
 {
 	struct baycom_state *bc = netdev_priv(dev);
 
+	if (skb->protocol == htons(ETH_P_IP))
+		return ax25_ip_xmit(skb);
+
 	if (skb->data[0] != 0) {
 		do_kiss_params(bc, skb->data, skb->len);
 		dev_kfree_skb(skb);
@@ -1109,7 +1112,6 @@ static const struct net_device_ops baycom_netdev_ops = {
 	.ndo_do_ioctl	     = baycom_ioctl,
 	.ndo_start_xmit      = baycom_send_packet,
 	.ndo_set_mac_address = baycom_set_mac_address,
-	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 /*
@@ -1147,7 +1149,6 @@ static void baycom_probe(struct net_device *dev)
 	dev->header_ops = &ax25_header_ops;
 	
 	dev->type = ARPHRD_AX25;           /* AF_AX25 device */
-	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 	dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 	dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
diff --git a/drivers/net/hamradio/bpqether.c b/drivers/net/hamradio/bpqether.c
index bce105b16ed0..63ff08a26da8 100644
--- a/drivers/net/hamradio/bpqether.c
+++ b/drivers/net/hamradio/bpqether.c
@@ -251,6 +251,9 @@ static netdev_tx_t bpq_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct net_device *orig_dev;
 	int size;
 
+	if (skb->protocol == htons(ETH_P_IP))
+		return ax25_ip_xmit(skb);
+
 	/*
 	 * Just to be *really* sure not to send anything if the interface
 	 * is down, the ethernet device may have gone.
@@ -469,7 +472,6 @@ static const struct net_device_ops bpq_netdev_ops = {
 	.ndo_start_xmit	     = bpq_xmit,
 	.ndo_set_mac_address = bpq_set_mac_address,
 	.ndo_do_ioctl	     = bpq_ioctl,
-	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 static void bpq_setup(struct net_device *dev)
@@ -487,7 +489,6 @@ static void bpq_setup(struct net_device *dev)
 #endif
 
 	dev->type            = ARPHRD_AX25;
-	dev->neigh_priv_len  = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 	dev->mtu             = AX25_DEF_PACLEN;
 	dev->addr_len        = AX25_ADDR_LEN;
diff --git a/drivers/net/hamradio/dmascc.c b/drivers/net/hamradio/dmascc.c
index abab7be77406..c3d377770616 100644
--- a/drivers/net/hamradio/dmascc.c
+++ b/drivers/net/hamradio/dmascc.c
@@ -433,7 +433,6 @@ module_exit(dmascc_exit);
 static void __init dev_setup(struct net_device *dev)
 {
 	dev->type = ARPHRD_AX25;
-	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN;
 	dev->mtu = 1500;
 	dev->addr_len = AX25_ADDR_LEN;
@@ -448,7 +447,6 @@ static const struct net_device_ops scc_netdev_ops = {
 	.ndo_start_xmit = scc_send_packet,
 	.ndo_do_ioctl = scc_ioctl,
 	.ndo_set_mac_address = scc_set_mac_address,
-	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 static int __init setup_adapter(int card_base, int type, int n)
@@ -922,6 +920,9 @@ static int scc_send_packet(struct sk_buff *skb, struct net_device *dev)
 	unsigned long flags;
 	int i;
 
+	if (skb->protocol == htons(ETH_P_IP))
+		return ax25_ip_xmit(skb);
+
 	/* Temporarily stop the scheduler feeding us packets */
 	netif_stop_queue(dev);
 
diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
index 435868a7b69c..49fe59b180a8 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -404,6 +404,9 @@ static netdev_tx_t hdlcdrv_send_packet(struct sk_buff *skb,
 {
 	struct hdlcdrv_state *sm = netdev_priv(dev);
 
+	if (skb->protocol == htons(ETH_P_IP))
+		return ax25_ip_xmit(skb);
+
 	if (skb->data[0] != 0) {
 		do_kiss_params(sm, skb->data, skb->len);
 		dev_kfree_skb(skb);
@@ -626,7 +629,6 @@ static const struct net_device_ops hdlcdrv_netdev = {
 	.ndo_start_xmit = hdlcdrv_send_packet,
 	.ndo_do_ioctl	= hdlcdrv_ioctl,
 	.ndo_set_mac_address = hdlcdrv_set_mac_address,
-	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 /*
@@ -677,7 +679,6 @@ static void hdlcdrv_setup(struct net_device *dev)
 	dev->header_ops = &ax25_header_ops;
 	
 	dev->type = ARPHRD_AX25;           /* AF_AX25 device */
-	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 	dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 	dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index c12ec2c2b594..17058c490b79 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -529,6 +529,9 @@ static netdev_tx_t ax_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct mkiss *ax = netdev_priv(dev);
 
+	if (skb->protocol == htons(ETH_P_IP))
+		return ax25_ip_xmit(skb);
+
 	if (!netif_running(dev))  {
 		printk(KERN_ERR "mkiss: %s: xmit call when iface is down\n", dev->name);
 		return NETDEV_TX_BUSY;
@@ -641,7 +644,6 @@ static const struct net_device_ops ax_netdev_ops = {
 	.ndo_stop            = ax_close,
 	.ndo_start_xmit	     = ax_xmit,
 	.ndo_set_mac_address = ax_set_mac_address,
-	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 static void ax_setup(struct net_device *dev)
@@ -651,7 +653,6 @@ static void ax_setup(struct net_device *dev)
 	dev->hard_header_len = 0;
 	dev->addr_len        = 0;
 	dev->type            = ARPHRD_AX25;
-	dev->neigh_priv_len  = sizeof(struct ax25_neigh_priv);
 	dev->tx_queue_len    = 10;
 	dev->header_ops      = &ax25_header_ops;
 	dev->netdev_ops	     = &ax_netdev_ops;
diff --git a/drivers/net/hamradio/scc.c b/drivers/net/hamradio/scc.c
index b305f51eb420..ce88df33fe17 100644
--- a/drivers/net/hamradio/scc.c
+++ b/drivers/net/hamradio/scc.c
@@ -1550,7 +1550,6 @@ static const struct net_device_ops scc_netdev_ops = {
 	.ndo_set_mac_address = scc_net_set_mac_address,
 	.ndo_get_stats       = scc_net_get_stats,
 	.ndo_do_ioctl        = scc_net_ioctl,
-	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 /* ----> Initialize device <----- */
@@ -1568,7 +1567,6 @@ static void scc_net_setup(struct net_device *dev)
 	dev->flags      = 0;
 
 	dev->type = ARPHRD_AX25;
-	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 	dev->mtu = AX25_DEF_PACLEN;
 	dev->addr_len = AX25_ADDR_LEN;
@@ -1641,6 +1639,9 @@ static netdev_tx_t scc_net_tx(struct sk_buff *skb, struct net_device *dev)
 	unsigned long flags;
 	char kisscmd;
 
+	if (skb->protocol == htons(ETH_P_IP))
+		return ax25_ip_xmit(skb);
+
 	if (skb->len > scc->stat.bufsize || skb->len < 2) {
 		scc->dev_stat.tx_dropped++;	/* bogus frame */
 		dev_kfree_skb(skb);
diff --git a/drivers/net/hamradio/yam.c b/drivers/net/hamradio/yam.c
index 89d9da7a0c51..1a4729c36aa4 100644
--- a/drivers/net/hamradio/yam.c
+++ b/drivers/net/hamradio/yam.c
@@ -597,6 +597,9 @@ static netdev_tx_t yam_send_packet(struct sk_buff *skb,
 {
 	struct yam_port *yp = netdev_priv(dev);
 
+	if (skb->protocol == htons(ETH_P_IP))
+		return ax25_ip_xmit(skb);
+
 	skb_queue_tail(&yp->send_queue, skb);
 	dev->trans_start = jiffies;
 	return NETDEV_TX_OK;
@@ -1100,7 +1103,6 @@ static const struct net_device_ops yam_netdev_ops = {
 	.ndo_start_xmit      = yam_send_packet,
 	.ndo_do_ioctl 	     = yam_ioctl,
 	.ndo_set_mac_address = yam_set_mac_address,
-	.ndo_neigh_construct = ax25_neigh_construct,
 };
 
 static void yam_setup(struct net_device *dev)
@@ -1129,7 +1131,6 @@ static void yam_setup(struct net_device *dev)
 	dev->header_ops = &ax25_header_ops;
 
 	dev->type = ARPHRD_AX25;
-	dev->neigh_priv_len = sizeof(struct ax25_neigh_priv);
 	dev->hard_header_len = AX25_MAX_HEADER_LEN;
 	dev->mtu = AX25_MTU;
 	dev->addr_len = AX25_ADDR_LEN;
diff --git a/include/net/ax25.h b/include/net/ax25.h
index 45feeba7a325..16a923a3a43a 100644
--- a/include/net/ax25.h
+++ b/include/net/ax25.h
@@ -367,11 +367,8 @@ int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
 		  struct net_device *);
 
 /* ax25_ip.c */
-int ax25_neigh_construct(struct neighbour *neigh);
+netdev_tx_t ax25_ip_xmit(struct sk_buff *skb);
 extern const struct header_ops ax25_header_ops;
-struct ax25_neigh_priv {
-	struct neigh_ops ops;
-};
 
 /* ax25_out.c */
 ax25_cb *ax25_send_frame(struct sk_buff *, int, ax25_address *, ax25_address *,
diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index e030c64ebfb7..8b35af4ef93e 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -100,7 +100,7 @@ static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
 	return -AX25_HEADER_LEN;	/* Unfinished header */
 }
 
-static int ax25_neigh_xmit(struct sk_buff *skb)
+netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
 {
 	struct sk_buff *ourskb;
 	unsigned char *bp  = skb->data;
@@ -210,56 +210,7 @@ put:
 	if (route)
 		ax25_put_route(route);
 
-	return 1;
-}
-
-static int ax25_neigh_output(struct neighbour *neigh, struct sk_buff *skb)
-{
-	/* Except for calling ax25_neigh_xmit instead of
-	 * dev_queue_xmit this is neigh_resolve_output.
-	 */
-	int rc = 0;
-
-	if (!neigh_event_send(neigh, skb)) {
-		int err;
-		struct net_device *dev = neigh->dev;
-		unsigned int seq;
-
-		do {
-			__skb_pull(skb, skb_network_offset(skb));
-			seq = read_seqbegin(&neigh->ha_lock);
-			err = dev_hard_header(skb, dev, ntohs(skb->protocol),
-					      neigh->ha, NULL, skb->len);
-		} while (read_seqretry(&neigh->ha_lock, seq));
-
-		if (err >= 0) {
-			ax25_neigh_xmit(skb);
-		} else
-			goto out_kfree_skb;
-	}
-out:
-	return rc;
-
-out_kfree_skb:
-	rc = -EINVAL;
-	kfree_skb(skb);
-	goto out;
-}
-
-int ax25_neigh_construct(struct neighbour *neigh)
-{
-	/* This trouble could be saved if ax25 would right a proper
-	 * dev_queue_xmit function.
-	 */
-	struct ax25_neigh_priv *priv = neighbour_priv(neigh);
-
-	if (neigh->tbl->family != AF_INET)
-		return -EINVAL;
-
-	priv->ops = *neigh->ops;
-	priv->ops.output = ax25_neigh_output;
-	priv->ops.connected_output = ax25_neigh_output;
-	return 0;
+	return NETDEV_TX_OK;
 }
 
 #else	/* INET */
@@ -271,9 +222,10 @@ static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
 	return -AX25_HEADER_LEN;
 }
 
-int ax25_neigh_construct(struct neighbour *neigh)
+netdev_tx_t ax25_ip_xmit(sturct sk_buff *skb)
 {
-	return 0;
+	kfree_skb(skb);
+	return NETDEV_TX_OK;
 }
 #endif
 
@@ -282,5 +234,5 @@ const struct header_ops ax25_header_ops = {
 };
 
 EXPORT_SYMBOL(ax25_header_ops);
-EXPORT_SYMBOL(ax25_neigh_construct);
+EXPORT_SYMBOL(ax25_ip_xmit);
 
-- 
2.2.1

Re: [PATCH net-next] ax25: Stop using magic neighbour cache operations.

[David Miller]

From: ebiederm@xmission.com (Eric W. Biederman)
Date: Tue, 03 Mar 2015 09:41:47 -0600

> 
> Before the ax25 stack calls dev_queue_xmit it always calls
> ax25_type_trans which sets skb->protocol to ETH_P_AX25.
> 
> Which means that by looking at the protocol type it is possible to
> detect IP packets that have not been munged by the ax25 stack in
> ndo_start_xmit and call a function to munge them.
> 
> Rename ax25_neigh_xmit to ax25_ip_xmit and tweak the return type and
> value to be appropriate for an ndo_start_xmit function.
> 
> Update all of the ax25 devices to test the protocol type for ETH_P_IP
> and return ax25_ip_xmit as the first thing they do.  This preserves
> the existing semantics of IP packet processing, but the timing will be
> a little different as the IP packets now pass through the qdisc layer
> before reaching the ax25 ip packet processing.
> 
> Remove the now unnecessary ax25 neighbour table operations.
> 
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Another nice cleanup, applied, thanks Eric.

Re: [PATCH net-next] ax25: Stop using magic neighbour cache operations.

[Eric W. Biederman]

David Miller <davem@davemloft.net> writes:

> From: ebiederm@xmission.com (Eric W. Biederman)
> Date: Tue, 03 Mar 2015 09:41:47 -0600
>
>> 
>> Before the ax25 stack calls dev_queue_xmit it always calls
>> ax25_type_trans which sets skb->protocol to ETH_P_AX25.
>> 
>> Which means that by looking at the protocol type it is possible to
>> detect IP packets that have not been munged by the ax25 stack in
>> ndo_start_xmit and call a function to munge them.
>> 
>> Rename ax25_neigh_xmit to ax25_ip_xmit and tweak the return type and
>> value to be appropriate for an ndo_start_xmit function.
>> 
>> Update all of the ax25 devices to test the protocol type for ETH_P_IP
>> and return ax25_ip_xmit as the first thing they do.  This preserves
>> the existing semantics of IP packet processing, but the timing will be
>> a little different as the IP packets now pass through the qdisc layer
>> before reaching the ax25 ip packet processing.
>> 
>> Remove the now unnecessary ax25 neighbour table operations.
>> 
>> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
>
> Another nice cleanup, applied, thanks Eric.

We can almost universally use the same procedures for generating
link layer headers from neighbour table entries now.  I had hoped
to optimized things by removing function pointers.

The big hold out is DECnet that sets src_mac based on the DECnet source
address.  

Which leads me to the conclusion that since DECnet has a different
algorithm for setting the src_mac than everything else in the kernel
DECnet neighbour table entries can not be used for nexthops for other
protocols :(

DECnet also abuses neigh->output to select by output device which kind
of DECnet header to put on the packets.  But that is easily fixable.

Anyway slowly slowly the neighbour table code becomes more readable
and maintable.

Eric

Re: [PATCH net-next] ax25: Stop using magic neighbour cache operations.

[David Miller]

From: ebiederm@xmission.com (Eric W. Biederman)
Date: Tue, 03 Mar 2015 14:22:41 -0600

> Anyway slowly slowly the neighbour table code becomes more readable
> and maintable.

Without question, thanks again Eric.

Re: [PATCH net-next] ax25: Stop using magic neighbour cache operations.

[Steven Whitehouse]

Hi,

On 03/03/15 20:22, Eric W. Biederman wrote:
> David Miller <davem@davemloft.net> writes:
>
>> From: ebiederm@xmission.com (Eric W. Biederman)
>> Date: Tue, 03 Mar 2015 09:41:47 -0600
>>
>>> Before the ax25 stack calls dev_queue_xmit it always calls
>>> ax25_type_trans which sets skb->protocol to ETH_P_AX25.
>>>
>>> Which means that by looking at the protocol type it is possible to
>>> detect IP packets that have not been munged by the ax25 stack in
>>> ndo_start_xmit and call a function to munge them.
>>>
>>> Rename ax25_neigh_xmit to ax25_ip_xmit and tweak the return type and
>>> value to be appropriate for an ndo_start_xmit function.
>>>
>>> Update all of the ax25 devices to test the protocol type for ETH_P_IP
>>> and return ax25_ip_xmit as the first thing they do.  This preserves
>>> the existing semantics of IP packet processing, but the timing will be
>>> a little different as the IP packets now pass through the qdisc layer
>>> before reaching the ax25 ip packet processing.
>>>
>>> Remove the now unnecessary ax25 neighbour table operations.
>>>
>>> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
>> Another nice cleanup, applied, thanks Eric.
> We can almost universally use the same procedures for generating
> link layer headers from neighbour table entries now.  I had hoped
> to optimized things by removing function pointers.
>
> The big hold out is DECnet that sets src_mac based on the DECnet source
> address.
That is a requirement of DECnet I'm afraid - DECnet does not have an 
exact equivalent of ARP/ndisc and many hosts will refuse to communicate 
if the MAC address is not the expected one based on the DECnet address. 
This is one bit of DECnet that is being used (to the best of my 
knowledge) and working.

> Which leads me to the conclusion that since DECnet has a different
> algorithm for setting the src_mac than everything else in the kernel
> DECnet neighbour table entries can not be used for nexthops for other
> protocols :(
>
> DECnet also abuses neigh->output to select by output device which kind
> of DECnet header to put on the packets.  But that is easily fixable.
One way to fix it would be to drop support for non-broadcast devices. We 
don't have an implementation of DDCMP currently. Ethernet is the only 
working DECnet device at the moment. PPP could also potentially work, 
with a bit of tweeking, but strangely PPP is a broadcast device so far 
as DECnet is concerned,

Steve.

Re: [PATCH net-next] ax25: Stop using magic neighbour cache operations.

[Eric W. Biederman]

Steven Whitehouse <swhiteho@redhat.com> writes:

> Hi,


>> We can almost universally use the same procedures for generating
>> link layer headers from neighbour table entries now.  I had hoped
>> to optimized things by removing function pointers.
>>
>> The big hold out is DECnet that sets src_mac based on the DECnet source
>> address.
> That is a requirement of DECnet I'm afraid - DECnet does not have an exact
> equivalent of ARP/ndisc and many hosts will refuse to communicate if the MAC
> address is not the expected one based on the DECnet address. This is one bit of
> DECnet that is being used (to the best of my knowledge) and working.

Having a mac address that matches the DECnet address completely makes
sense.  Sourcing packets with a different mac address than the devices
default mac address make sense.  This latter case doesn't usually happen
for IP packets but we force it with the macvlan driver for example.

>> Which leads me to the conclusion that since DECnet has a different
>> algorithm for setting the src_mac than everything else in the kernel
>> DECnet neighbour table entries can not be used for nexthops for other
>> protocols :(
>>
>> DECnet also abuses neigh->output to select by output device which kind
>> of DECnet header to put on the packets.  But that is easily fixable.
> One way to fix it would be to drop support for non-broadcast devices. We don't
> have an implementation of DDCMP currently. Ethernet is the only working DECnet
> device at the moment. PPP could also potentially work, with a bit of tweeking,
> but strangely PPP is a broadcast device so far as DECnet is concerned,

What I wound up doing was just doing a shuffle of which function was in
the neigh->output method.  Which meant there was no need to disable any
of the current code.

That should fix interactions between DECnet and drivers like sch_teql
and the netfilter bridge code which after a packet has already been
output turn around and do:

	dst = skb_dst(skb);
	neigh = n = dst_neigh_lookup_skb(dst, skb);
        if (dst->dev != dev)
        	neigh = __neigh_lookup_errno(n->tbl, n->primary_key, dev);
	neigh->output(neigh, skb);

Which I think if the DECnet code hit one of those code paths today would
result in double DECnet headers.  :(

When looking at the DECnet code there is a flag that enables phase3
support but I don't seeing it set anywhere.  Should DECnet phase3
support actually work?

Eric

Re: [PATCH net-next] ax25: Stop using magic neighbour cache operations.

[Steven Whitehouse]

Hi,

On 06/03/15 20:44, Eric W. Biederman wrote:
> Steven Whitehouse <swhiteho@redhat.com> writes:
>
>> Hi,
>
>>> We can almost universally use the same procedures for generating
>>> link layer headers from neighbour table entries now.  I had hoped
>>> to optimized things by removing function pointers.
>>>
>>> The big hold out is DECnet that sets src_mac based on the DECnet source
>>> address.
>> That is a requirement of DECnet I'm afraid - DECnet does not have an exact
>> equivalent of ARP/ndisc and many hosts will refuse to communicate if the MAC
>> address is not the expected one based on the DECnet address. This is one bit of
>> DECnet that is being used (to the best of my knowledge) and working.
> Having a mac address that matches the DECnet address completely makes
> sense.  Sourcing packets with a different mac address than the devices
> default mac address make sense.  This latter case doesn't usually happen
> for IP packets but we force it with the macvlan driver for example.
The history is that when DECnet was being written, it was not generally 
reliable to have a different MAC to that of the ethernet card - it 
worked for some cards, but by no means all of them. So it is something 
that would be done slightly differently with modern cards.

>>> Which leads me to the conclusion that since DECnet has a different
>>> algorithm for setting the src_mac than everything else in the kernel
>>> DECnet neighbour table entries can not be used for nexthops for other
>>> protocols :(
>>>
>>> DECnet also abuses neigh->output to select by output device which kind
>>> of DECnet header to put on the packets.  But that is easily fixable.
>> One way to fix it would be to drop support for non-broadcast devices. We don't
>> have an implementation of DDCMP currently. Ethernet is the only working DECnet
>> device at the moment. PPP could also potentially work, with a bit of tweeking,
>> but strangely PPP is a broadcast device so far as DECnet is concerned,
> What I wound up doing was just doing a shuffle of which function was in
> the neigh->output method.  Which meant there was no need to disable any
> of the current code.
>
> That should fix interactions between DECnet and drivers like sch_teql
> and the netfilter bridge code which after a packet has already been
> output turn around and do:
>
> 	dst = skb_dst(skb);
> 	neigh = n = dst_neigh_lookup_skb(dst, skb);
>          if (dst->dev != dev)
>          	neigh = __neigh_lookup_errno(n->tbl, n->primary_key, dev);
> 	neigh->output(neigh, skb);
>
> Which I think if the DECnet code hit one of those code paths today would
> result in double DECnet headers.  :(
>
> When looking at the DECnet code there is a flag that enables phase3
> support but I don't seeing it set anywhere.  Should DECnet phase3
> support actually work?
>
> Eric

Ok. That sounds reasonable to me. The phase 3 stuff is another stub 
really... most of what is needed is there, but not all of it. Phase 3 is 
basically the same as Phase IV but without areas and broadcast devices, 
so in order to make Phase 3 devices reachable on a Phase IV network, the 
Phase IV router has to add an area and forward the packet on, and remove 
the area when sending to the Phase 3 node. However since we don't have 
non-broadcast DECnet devices, there is no point in having Phase3 support 
really. At least it is one area on which the spec is quite useful 
though, as this is fairly well described,

Steve.