From ff3a5af3d7f78577899626b2f8b612369e051916 Mon Sep 17 00:00:00 2001

From: Miroslav Rezanina <mrezanin@redhat.com>

Date: Mon, 2 Aug 2021 08:32:33 -0400

Subject: [PATCH 3/5] [netdevice] Strip 802.Q VLAN 0 priority tags

RH-Author: Miroslav Rezanina <mrezanin@redhat.com>

RH-MergeRequest: 6: Forwardport  missing RHEL 8 downsteream changes

RH-Commit: [3/5] 440560659da2028f365a71b4ed4991955022dce5 (mrezanin/centos-src-ipxe)

RH-Bugzilla: 1985658

iPXE was unable to receive priority tagged packets specified in

the 802.1Q standard and supported by all major networking stacks.

This commit adds a new function net_pull_tags which is called by

all consumers of incoming packets after stripping their link-layer

headers.

Upstream patch:

http://lists.ipxe.org/pipermail/ipxe-devel/2016-July/005099.html

Downstream changes:

Upstream commit fe680c822856 made vlan_find static. This prevents

it's usage int this patch. Reverting changes adding static for

vlan_find.

Signed-off-by: Ladi Prosek <lprosek@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 src/arch/x86/interface/pxe/pxe_undi.c |  6 +++

 src/include/ipxe/netdevice.h          |  2 +

 src/include/ipxe/vlan.h               |  2 +

 src/interface/efi/efi_snp.c           |  7 ++++

 src/net/netdevice.c                   | 57 +++++++++++++++++++++++++++

 src/net/vlan.c                        |  2 +-

 6 files changed, 75 insertions(+), 1 deletion(-)

diff --git a/src/arch/x86/interface/pxe/pxe_undi.c b/src/arch/x86/interface/pxe/pxe_undi.c

index 2eb68178..2ea14515 100644

--- a/src/arch/x86/interface/pxe/pxe_undi.c

+++ b/src/arch/x86/interface/pxe/pxe_undi.c

@@ -976,6 +976,12 @@ static PXENV_EXIT_t pxenv_undi_isr ( struct s_PXENV_UNDI_ISR *undi_isr ) {

 		}

 		ll_hlen = ( len - iob_len ( iobuf ) );

+		/* Strip link-layer-independent headers */

+		if ( ( rc = net_pull_tags ( iobuf, pxe_netdev, &net_proto ) ) != 0 ) {

+			/* Assume unknown net_proto */

+			net_proto = 0;

+		}

+

 		/* Determine network-layer protocol */

 		switch ( net_proto ) {

 		case htons ( ETH_P_IP ):

diff --git a/src/include/ipxe/netdevice.h b/src/include/ipxe/netdevice.h

index d498ab69..27dda45d 100644

--- a/src/include/ipxe/netdevice.h

+++ b/src/include/ipxe/netdevice.h

@@ -726,6 +726,8 @@ extern int net_tx ( struct io_buffer *iobuf, struct net_device *netdev,

 extern int net_rx ( struct io_buffer *iobuf, struct net_device *netdev,

 		    uint16_t net_proto, const void *ll_dest,

 		    const void *ll_source, unsigned int flags );

+extern int net_pull_tags ( struct io_buffer *iobuf, struct net_device *netdev,

+			   uint16_t *net_proto );

 extern void net_poll ( void );

 extern struct net_device_configurator *

 find_netdev_configurator ( const char *name );

diff --git a/src/include/ipxe/vlan.h b/src/include/ipxe/vlan.h

index 7f93439b..b82f3806 100644

--- a/src/include/ipxe/vlan.h

+++ b/src/include/ipxe/vlan.h

@@ -61,6 +61,8 @@ struct vlan_header {

  */

 #define VLAN_PRIORITY_IS_VALID( priority ) ( (priority) <= 7 )

+extern struct net_device * vlan_find ( struct net_device *trunk,

+                                      unsigned int tag );

 extern unsigned int vlan_tag ( struct net_device *netdev );

 extern int vlan_can_be_trunk ( struct net_device *trunk );

 extern int vlan_create ( struct net_device *trunk, unsigned int tag,

diff --git a/src/interface/efi/efi_snp.c b/src/interface/efi/efi_snp.c

index d648700f..a8f2ac8e 100644

--- a/src/interface/efi/efi_snp.c

+++ b/src/interface/efi/efi_snp.c

@@ -813,6 +813,13 @@ efi_snp_receive ( EFI_SIMPLE_NETWORK_PROTOCOL *snp,

 		goto out_bad_ll_header;

 	}

+	/* Strip link-layer-independent headers */

+	if ( ( rc = net_pull_tags ( iobuf, snpdev->netdev, &iob_net_proto ) ) ) {

+		DBGC ( snpdev, "SNPDEV %p could not parse tags: %s\n",

+		       snpdev, strerror ( rc ) );

+		goto out_bad_ll_header;

+	}

+

 	/* Return link-layer header parameters to caller, if required */

 	if ( ll_header_len )

 		*ll_header_len = ll_protocol->ll_header_len;

diff --git a/src/net/netdevice.c b/src/net/netdevice.c

index 3b02e64b..95803f26 100644

--- a/src/net/netdevice.c

+++ b/src/net/netdevice.c

@@ -1043,6 +1043,45 @@ int net_rx ( struct io_buffer *iobuf, struct net_device *netdev,

 	return -ENOTSUP;

 }

+

+/**

+ * Strip extra link-layer-independent tags from a received packet

+ *

+ * @v iobuf		I/O buffer

+ * @v netdev		Network device

+ * @v net_proto		Network-layer protocol, in network-byte order

+ * @ret rc		Return status code

+ *

+ * This function should be called after stripping link-layer headers but

+ * before inspecting the network-layer protocol.

+ */

+int net_pull_tags ( struct io_buffer *iobuf, struct net_device *netdev,

+		    uint16_t *net_proto ) {

+	struct vlan_header *vlanhdr;

+	uint16_t tag;

+

+	/* Strip 802.1Q VLAN 0 priority tags if present */

+	while ( *net_proto == htons ( ETH_P_8021Q ) ) {

+		if ( iob_len ( iobuf ) < sizeof ( *vlanhdr ) ) {

+			DBG ( "VLAN header too short at %zd bytes (min %zd bytes)\n",

+			      iob_len ( iobuf ), sizeof ( *vlanhdr ) );

+			return -EINVAL;

+		}

+		vlanhdr = ( struct vlan_header * ) iobuf->data;

+		tag = VLAN_TAG ( ntohs ( vlanhdr->tci ) );

+

+		if ( tag == 0 && ! vlan_find ( netdev, tag ) ) {

+			/* VLAN 0, strip and continue */

+			*net_proto = vlanhdr->net_proto;

+			iob_pull ( iobuf, sizeof ( *vlanhdr ) );

+		} else {

+			/* Real VLAN tag, leave it alone */

+			break;

+		}

+	}

+	return 0;

+}

+

 /**

  * Poll the network stack

  *

@@ -1094,6 +1133,12 @@ void net_poll ( void ) {

 				continue;

 			}

+			/* Remove link-layer-independent headers */

+			if ( ( rc = net_pull_tags ( iobuf, netdev, &net_proto ) ) ) {

+				free_iob ( iobuf );

+				continue;

+			}

+

 			/* Hand packet to network layer */

 			if ( ( rc = net_rx ( iob_disown ( iobuf ), netdev,

 					     net_proto, ll_dest,

@@ -1125,6 +1170,18 @@ __weak unsigned int vlan_tag ( struct net_device *netdev __unused ) {

 	return 0;

 }

+/**

+ * Identify VLAN device (when VLAN support is not present)

+ *

+ * @v netdev           Network device

+ * @v tag              VLAN tag, or zero

+ * @v iobuf            I/O buffer

+ */

+__weak struct net_device * vlan_find ( struct net_device *trunk __unused,

+                                      unsigned int tag __unused ) {

+       return NULL;

+}

+

 /**

  * Add VLAN tag-stripped packet to queue (when VLAN support is not present)

  *

diff --git a/src/net/vlan.c b/src/net/vlan.c

index 90f2934d..0f234ea5 100644

--- a/src/net/vlan.c

+++ b/src/net/vlan.c

@@ -199,7 +199,7 @@ static void vlan_sync ( struct net_device *netdev ) {

  * @v tag		VLAN tag

  * @ret netdev		VLAN device, if any

  */

-static struct net_device * vlan_find ( struct net_device *trunk,

+struct net_device * vlan_find ( struct net_device *trunk,

 				       unsigned int tag ) {

 	struct net_device *netdev;

 	struct vlan_device *vlan;

-- 

2.27.0