From 99e943834fc6708fb8bd8f329988979433db19e8 Mon Sep 17 00:00:00 2001

From: Phil Sutter <psutter@redhat.com>

Date: Thu, 9 Feb 2023 10:27:58 +0100

Subject: [PATCH] src: allow anon set concatenation with ether and vlan

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2094887

Upstream Status: nftables commit c1c223f1b5818

commit c1c223f1b58188542222ee2d9a4a8cc133d1dc3b

Author: Florian Westphal <fw@strlen.de>

Date:   Mon Jul 25 21:34:52 2022 +0200

    src: allow anon set concatenation with ether and vlan

    vlan id uses integer type (which has a length of 0).

    Using it was possible, but listing would assert:

    python: mergesort.c:24: concat_expr_msort_value: Assertion `ilen > 0' failed.

    There are two reasons for this.

    First reason is that the udata/typeof information lacks the 'vlan id'

    part, because internally this is 'payload . binop(payload AND mask)'.

    binop lacks an udata store.  It makes little sense to store it,

    'typeof' keyword expects normal match syntax.

    So, when storing udata, store the left hand side of the binary

    operation, i.e. the load of the 2-byte key.

    With that resolved, delinerization could work, but concat_elem_expr()

    would splice 12 bits off the elements value, but it should be 16 (on

    a byte boundary).

    Signed-off-by: Florian Westphal <fw@strlen.de>

Signed-off-by: Phil Sutter <psutter@redhat.com>

---

 src/expression.c                      | 17 +++++++++--

 src/netlink.c                         | 10 +++++--

 tests/py/bridge/vlan.t                |  2 ++

 tests/py/bridge/vlan.t.json           | 41 +++++++++++++++++++++++++++

 tests/py/bridge/vlan.t.payload        | 12 ++++++++

 tests/py/bridge/vlan.t.payload.netdev | 14 +++++++++

 6 files changed, 91 insertions(+), 5 deletions(-)

diff --git a/src/expression.c b/src/expression.c

index deb649e..7390089 100644

--- a/src/expression.c

+++ b/src/expression.c

@@ -879,17 +879,30 @@ static void concat_expr_print(const struct expr *expr, struct output_ctx *octx)

 #define NFTNL_UDATA_SET_KEY_CONCAT_SUB_DATA 1

 #define NFTNL_UDATA_SET_KEY_CONCAT_SUB_MAX  2

+static struct expr *expr_build_udata_recurse(struct expr *e)

+{

+	switch (e->etype) {

+	case EXPR_BINOP:

+		return e->left;

+	default:

+		break;

+	}

+

+	return e;

+}

+

 static int concat_expr_build_udata(struct nftnl_udata_buf *udbuf,

 				    const struct expr *concat_expr)

 {

 	struct nftnl_udata *nest;

+	struct expr *expr, *tmp;

 	unsigned int i = 0;

-	struct expr *expr;

-	list_for_each_entry(expr, &concat_expr->expressions, list) {

+	list_for_each_entry_safe(expr, tmp, &concat_expr->expressions, list) {

 		struct nftnl_udata *nest_expr;

 		int err;

+		expr = expr_build_udata_recurse(expr);

 		if (!expr_ops(expr)->build_udata || i >= NFT_REG32_SIZE)

 			return -1;

diff --git a/src/netlink.c b/src/netlink.c

index 89d864e..799cf9b 100644

--- a/src/netlink.c

+++ b/src/netlink.c

@@ -1114,17 +1114,21 @@ static struct expr *concat_elem_expr(struct expr *key,

 				     struct expr *data, int *off)

 {

 	const struct datatype *subtype;

+	unsigned int sub_length;

 	struct expr *expr;

 	if (key) {

 		(*off)--;

-		expr = constant_expr_splice(data, key->len);

+		sub_length = round_up(key->len, BITS_PER_BYTE);

+

+		expr = constant_expr_splice(data, sub_length);

 		expr->dtype = datatype_get(key->dtype);

 		expr->byteorder = key->byteorder;

 		expr->len = key->len;

 	} else {

 		subtype = concat_subtype_lookup(dtype->type, --(*off));

-		expr = constant_expr_splice(data, subtype->size);

+		sub_length = round_up(subtype->size, BITS_PER_BYTE);

+		expr = constant_expr_splice(data, sub_length);

 		expr->dtype = subtype;

 		expr->byteorder = subtype->byteorder;

 	}

@@ -1136,7 +1140,7 @@ static struct expr *concat_elem_expr(struct expr *key,

 	    expr->dtype->basetype->type == TYPE_BITMASK)

 		expr = bitmask_expr_to_binops(expr);

-	data->len -= netlink_padding_len(expr->len);

+	data->len -= netlink_padding_len(sub_length);

 	return expr;

 }

diff --git a/tests/py/bridge/vlan.t b/tests/py/bridge/vlan.t

index 4920601..95bdff4 100644

--- a/tests/py/bridge/vlan.t

+++ b/tests/py/bridge/vlan.t

@@ -50,3 +50,5 @@ vlan id 1 vlan id set 2;ok

 ether saddr 00:01:02:03:04:05 vlan id 1;ok

 vlan id 2 ether saddr 0:1:2:3:4:6;ok;ether saddr 00:01:02:03:04:06 vlan id 2

+

+ether saddr . vlan id { 0a:0b:0c:0d:0e:0f . 42, 0a:0b:0c:0d:0e:0f . 4095 };ok

diff --git a/tests/py/bridge/vlan.t.json b/tests/py/bridge/vlan.t.json

index 58d4a40..f77756f 100644

--- a/tests/py/bridge/vlan.t.json

+++ b/tests/py/bridge/vlan.t.json

@@ -817,3 +817,44 @@

         }

     }

 ]

+

+# ether saddr . vlan id { 0a:0b:0c:0d:0e:0f . 42, 0a:0b:0c:0d:0e:0f . 4095 }

+[

+    {

+        "match": {

+            "left": {

+                "concat": [

+                    {

+                        "payload": {

+                            "field": "saddr",

+                            "protocol": "ether"

+                        }

+                    },

+                    {

+                        "payload": {

+                            "field": "id",

+                            "protocol": "vlan"

+                        }

+                    }

+                ]

+            },

+            "op": "==",

+            "right": {

+                "set": [

+                    {

+                        "concat": [

+                            "0a:0b:0c:0d:0e:0f",

+                            42

+                        ]

+                    },

+                    {

+                        "concat": [

+                            "0a:0b:0c:0d:0e:0f",

+                            4095

+                        ]

+                    }

+                ]

+            }

+        }

+    }

+]

diff --git a/tests/py/bridge/vlan.t.payload b/tests/py/bridge/vlan.t.payload

index 713670e..62e4b89 100644

--- a/tests/py/bridge/vlan.t.payload

+++ b/tests/py/bridge/vlan.t.payload

@@ -292,3 +292,15 @@ bridge test-bridge input

   [ payload load 2b @ link header + 14 => reg 1 ]

   [ bitwise reg 1 = ( reg 1 & 0x0000ff0f ) ^ 0x00000000 ]

   [ cmp eq reg 1 0x00000200 ]

+

+# ether saddr . vlan id { 0a:0b:0c:0d:0e:0f . 42, 0a:0b:0c:0d:0e:0f . 4095 }

+__set%d test-bridge 3 size 2

+__set%d test-bridge 0

+	element 0d0c0b0a 00000f0e 00002a00  : 0 [end]	element 0d0c0b0a 00000f0e 0000ff0f  : 0 [end]

+bridge test-bridge input

+  [ payload load 2b @ link header + 12 => reg 1 ]

+  [ cmp eq reg 1 0x00000081 ]

+  [ payload load 6b @ link header + 6 => reg 1 ]

+  [ payload load 2b @ link header + 14 => reg 10 ]

+  [ bitwise reg 10 = ( reg 10 & 0x0000ff0f ) ^ 0x00000000 ]

+  [ lookup reg 1 set __set%d ]

diff --git a/tests/py/bridge/vlan.t.payload.netdev b/tests/py/bridge/vlan.t.payload.netdev

index 98a2a2b..1018d4c 100644

--- a/tests/py/bridge/vlan.t.payload.netdev

+++ b/tests/py/bridge/vlan.t.payload.netdev

@@ -342,3 +342,17 @@ netdev test-netdev ingress

   [ payload load 2b @ link header + 14 => reg 1 ]

   [ bitwise reg 1 = ( reg 1 & 0x0000ff0f ) ^ 0x00000000 ]

   [ cmp eq reg 1 0x00000100 ]

+

+# ether saddr . vlan id { 0a:0b:0c:0d:0e:0f . 42, 0a:0b:0c:0d:0e:0f . 4095 }

+__set%d test-netdev 3 size 2

+__set%d test-netdev 0

+	element 0d0c0b0a 00000f0e 00002a00  : 0 [end]	element 0d0c0b0a 00000f0e 0000ff0f  : 0 [end]

+netdev test-netdev ingress

+  [ meta load iiftype => reg 1 ]

+  [ cmp eq reg 1 0x00000001 ]

+  [ payload load 2b @ link header + 12 => reg 1 ]

+  [ cmp eq reg 1 0x00000081 ]

+  [ payload load 6b @ link header + 6 => reg 1 ]

+  [ payload load 2b @ link header + 14 => reg 10 ]

+  [ bitwise reg 10 = ( reg 10 & 0x0000ff0f ) ^ 0x00000000 ]

+  [ lookup reg 1 set __set%d ]

-- 

2.39.1