[PATCH iproute2-next] f_flower: Add l2_miss support

[PATCH iproute2-next] f_flower: Add l2_miss support

[Ido Schimmel]

Add the ability to match on packets that encountered a layer 2 miss in
bridge driver's FDB / MDB. Example:

 # tc filter add dev swp2 egress pref 1 proto all flower indev swp1 l2_miss 1 action drop
 # tc filter add dev swp2 egress pref 1 proto all flower indev swp1 l2_miss 0 action drop

 # tc filter show dev swp2 egress
 filter protocol all pref 1 flower chain 0
 filter protocol all pref 1 flower chain 0 handle 0x1
   indev swp1
   l2_miss 1
   not_in_hw
         action order 1: gact action drop
          random type none pass val 0
          index 1 ref 1 bind 1

 filter protocol all pref 1 flower chain 0 handle 0x2
   indev swp1
   l2_miss 0
   not_in_hw
         action order 1: gact action drop
          random type none pass val 0
          index 2 ref 1 bind 1

 # tc -j -p filter show dev swp2 egress
 [ {
         "protocol": "all",
         "pref": 1,
         "kind": "flower",
         "chain": 0
     },{
         "protocol": "all",
         "pref": 1,
         "kind": "flower",
         "chain": 0,
         "options": {
             "handle": 1,
             "indev": "swp1",
             "keys": {
                 "l2_miss": 1
             },
             "not_in_hw": true,
             "actions": [ {
 [...]
                 } ]
         }
     },{
         "protocol": "all",
         "pref": 1,
         "kind": "flower",
         "chain": 0,
         "options": {
             "handle": 2,
             "indev": "swp1",
             "keys": {
                 "l2_miss": 0
             },
             "not_in_hw": true,
             "actions": [ {
 [...]
                 } ]
         }
     } ]

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
Initially I used true / false instead of 1 / 0. If this patch is
accepted, I will adjust the kernel selftest accordingly.
---
 man/man8/tc-flower.8 | 10 +++++++++-
 tc/f_flower.c        | 18 ++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/man/man8/tc-flower.8 b/man/man8/tc-flower.8
index fc73da93c5c3..cd99745065cf 100644
--- a/man/man8/tc-flower.8
+++ b/man/man8/tc-flower.8
@@ -100,7 +100,9 @@ flower \- flow based traffic control filter
 }
 .IR OPTIONS " | "
 .BR ip_flags
-.IR IP_FLAGS " }"
+.IR IP_FLAGS " | "
+.B l2_miss
+.IR L2_MISS " }"
 
 .ti -8
 .IR LSE_LIST " := [ " LSE_LIST " ] " LSE
@@ -493,6 +495,12 @@ respectively. firstfrag and nofirstfrag can be used to further distinguish
 fragmented packet. firstfrag can be used to indicate the first fragmented
 packet. nofirstfrag can be used to indicates subsequent fragmented packets
 or non-fragmented packets.
+.TP
+.BI l2_miss " L2_MISS"
+Match on layer 2 miss in the bridge driver's FDB / MDB. \fIL2_MISS\fR may be 0
+or 1. When 1, match on packets that encountered a layer 2 miss. When 0, match
+on packets that were forwarded using an FDB / MDB entry. Note that broadcast
+packets do not encounter a miss since a lookup is not performed for them.
 .SH NOTES
 As stated above where applicable, matches of a certain layer implicitly depend
 on the matches of the next lower layer. Precisely, layer one and two matches
diff --git a/tc/f_flower.c b/tc/f_flower.c
index c73c46dd234b..f1a351fbaa03 100644
--- a/tc/f_flower.c
+++ b/tc/f_flower.c
@@ -91,6 +91,7 @@ static void explain(void)
 		"			erspan_opts MASKED-OPTIONS |\n"
 		"			gtp_opts MASKED-OPTIONS |\n"
 		"			ip_flags IP-FLAGS |\n"
+		"			l2_miss L2_MISS |\n"
 		"			enc_dst_port [ port_number ] |\n"
 		"			ct_state MASKED_CT_STATE |\n"
 		"			ct_label MASKED_CT_LABEL |\n"
@@ -1520,6 +1521,15 @@ static int flower_parse_opt(struct filter_util *qu, char *handle,
 				fprintf(stderr, "Illegal \"ip_flags\"\n");
 				return -1;
 			}
+		} else if (strcmp(*argv, "l2_miss") == 0) {
+			__u8 l2_miss;
+
+			NEXT_ARG();
+			if (get_u8(&l2_miss, *argv, 10)) {
+				fprintf(stderr, "Illegal \"l2_miss\"\n");
+				return -1;
+			}
+			addattr8(n, MAX_MSG, TCA_FLOWER_L2_MISS, l2_miss);
 		} else if (matches(*argv, "verbose") == 0) {
 			flags |= TCA_CLS_FLAGS_VERBOSE;
 		} else if (matches(*argv, "skip_hw") == 0) {
@@ -2983,6 +2993,14 @@ static int flower_print_opt(struct filter_util *qu, FILE *f,
 				    tb[TCA_FLOWER_KEY_FLAGS],
 				    tb[TCA_FLOWER_KEY_FLAGS_MASK]);
 
+	if (tb[TCA_FLOWER_L2_MISS]) {
+		struct rtattr *attr = tb[TCA_FLOWER_L2_MISS];
+
+		print_nl();
+		print_uint(PRINT_ANY, "l2_miss", "  l2_miss %d",
+			   rta_getattr_u8(attr));
+	}
+
 	flower_print_ct_state(tb[TCA_FLOWER_KEY_CT_STATE],
 			      tb[TCA_FLOWER_KEY_CT_STATE_MASK]);
 	flower_print_ct_zone(tb[TCA_FLOWER_KEY_CT_ZONE],
-- 
2.40.1

Re: [PATCH iproute2-next] f_flower: Add l2_miss support

[Stephen Hemminger]

On Wed, 7 Jun 2023 18:35:50 +0300
Ido Schimmel <idosch@nvidia.com> wrote:

> +		print_uint(PRINT_ANY, "l2_miss", "  l2_miss %d",
> +			   rta_getattr_u8(attr));

Use %u for unsigned?

Re: [PATCH iproute2-next] f_flower: Add l2_miss support

[David Ahern]

On 6/7/23 10:51 AM, Stephen Hemminger wrote:
> On Wed, 7 Jun 2023 18:35:50 +0300
> Ido Schimmel <idosch@nvidia.com> wrote:
> 
>> +		print_uint(PRINT_ANY, "l2_miss", "  l2_miss %d",
>> +			   rta_getattr_u8(attr));
> 
> Use %u for unsigned?

fixed up and applied