[PATCH iproute2-next 0/4] bridge: Add MAC Authentication Bypass (MAB) support

[PATCH iproute2-next 0/4] bridge: Add MAC Authentication Bypass (MAB) support

[Ido Schimmel]

Add MAB support in iproute2, allowing it to enable / disable MAB on a
bridge port and display the "locked" FDB flag.

Patch #1 syncs the kernel headers.

Patch #2 extends iproute2 to display the "locked" FDB flag when it is
set.

Patch #3 allows bridge(8) and ip(8) to enable / disable MAB on a bridge
port and display the current status.

Patch #4 rewords the description of the "locked" bridge port option.

Hans Schultz (2):
  bridge: fdb: Add support for locked FDB entries
  bridge: link: Add MAC Authentication Bypass (MAB) support

Ido Schimmel (2):
  Sync kernel headers
  man: bridge: Reword description of "locked" bridge port option

 bridge/fdb.c                   | 11 +++++++++--
 bridge/link.c                  | 13 +++++++++++++
 include/uapi/linux/if_link.h   |  1 +
 include/uapi/linux/neighbour.h |  8 +++++++-
 ip/iplink_bridge_slave.c       |  9 +++++++++
 man/man8/bridge.8              | 34 +++++++++++++++++++++++++++-------
 man/man8/ip-link.8.in          | 31 ++++++++++++++++++++++++++++---
 7 files changed, 94 insertions(+), 13 deletions(-)

-- 
2.37.3

[PATCH iproute2-next 1/4] Sync kernel headers

[Ido Schimmel]

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 include/uapi/linux/if_link.h   | 1 +
 include/uapi/linux/neighbour.h | 8 +++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 153fcb9617f8..4683fead5432 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -559,6 +559,7 @@ enum {
 	IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT,
 	IFLA_BRPORT_MCAST_EHT_HOSTS_CNT,
 	IFLA_BRPORT_LOCKED,
+	IFLA_BRPORT_MAB,
 	__IFLA_BRPORT_MAX
 };
 #define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1)
diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
index a998bf761635..5e67a7eaf4a7 100644
--- a/include/uapi/linux/neighbour.h
+++ b/include/uapi/linux/neighbour.h
@@ -52,7 +52,8 @@ enum {
 #define NTF_STICKY	(1 << 6)
 #define NTF_ROUTER	(1 << 7)
 /* Extended flags under NDA_FLAGS_EXT: */
-#define NTF_EXT_MANAGED	(1 << 0)
+#define NTF_EXT_MANAGED		(1 << 0)
+#define NTF_EXT_LOCKED		(1 << 1)
 
 /*
  *	Neighbor Cache Entry States.
@@ -86,6 +87,11 @@ enum {
  * NTF_EXT_MANAGED flagged neigbor entries are managed by the kernel on behalf
  * of a user space control plane, and automatically refreshed so that (if
  * possible) they remain in NUD_REACHABLE state.
+ *
+ * NTF_EXT_LOCKED flagged bridge FDB entries are entries generated by the
+ * bridge in response to a host trying to communicate via a locked bridge port
+ * with MAB enabled. Their purpose is to notify user space that a host requires
+ * authentication.
  */
 
 struct nda_cacheinfo {
-- 
2.37.3

[PATCH iproute2-next 2/4] bridge: fdb: Add support for locked FDB entries

[Ido Schimmel]

From: Hans Schultz <netdev@kapio-technology.com>

Print the "locked" FDB flag when it is set in the 'NDA_FLAGS_EXT'
attribute. Example output:

 # bridge fdb get 00:11:22:33:44:55 br br0
 00:11:22:33:44:55 dev swp1 locked master br0

 # bridge -j -p fdb get 00:11:22:33:44:55 br br0
 [ {
         "mac": "00:11:22:33:44:55",
         "ifname": "swp1",
         "flags": [ "locked" ],
         "master": "br0",
         "state": ""
     } ]

Signed-off-by: Hans Schultz <netdev@kapio-technology.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---

Notes:
    Changes made by me:
    * Use '__u32' instead of '__u8' in fdb_print_flags().
    * Reword commit message.

 bridge/fdb.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/bridge/fdb.c b/bridge/fdb.c
index 775feb1296af..ae8f7b4690f9 100644
--- a/bridge/fdb.c
+++ b/bridge/fdb.c
@@ -93,7 +93,7 @@ static int state_a2n(unsigned int *s, const char *arg)
 	return 0;
 }
 
-static void fdb_print_flags(FILE *fp, unsigned int flags)
+static void fdb_print_flags(FILE *fp, unsigned int flags, __u32 ext_flags)
 {
 	open_json_array(PRINT_JSON,
 			is_json_context() ?  "flags" : "");
@@ -116,6 +116,9 @@ static void fdb_print_flags(FILE *fp, unsigned int flags)
 	if (flags & NTF_STICKY)
 		print_string(PRINT_ANY, NULL, "%s ", "sticky");
 
+	if (ext_flags & NTF_EXT_LOCKED)
+		print_string(PRINT_ANY, NULL, "%s ", "locked");
+
 	close_json_array(PRINT_JSON, NULL);
 }
 
@@ -144,6 +147,7 @@ int print_fdb(struct nlmsghdr *n, void *arg)
 	struct ndmsg *r = NLMSG_DATA(n);
 	int len = n->nlmsg_len;
 	struct rtattr *tb[NDA_MAX+1];
+	__u32 ext_flags = 0;
 	__u16 vid = 0;
 
 	if (n->nlmsg_type != RTM_NEWNEIGH && n->nlmsg_type != RTM_DELNEIGH) {
@@ -170,6 +174,9 @@ int print_fdb(struct nlmsghdr *n, void *arg)
 	parse_rtattr(tb, NDA_MAX, NDA_RTA(r),
 		     n->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
 
+	if (tb[NDA_FLAGS_EXT])
+		ext_flags = rta_getattr_u32(tb[NDA_FLAGS_EXT]);
+
 	if (tb[NDA_VLAN])
 		vid = rta_getattr_u16(tb[NDA_VLAN]);
 
@@ -268,7 +275,7 @@ int print_fdb(struct nlmsghdr *n, void *arg)
 	if (show_stats && tb[NDA_CACHEINFO])
 		fdb_print_stats(fp, RTA_DATA(tb[NDA_CACHEINFO]));
 
-	fdb_print_flags(fp, r->ndm_flags);
+	fdb_print_flags(fp, r->ndm_flags, ext_flags);
 
 
 	if (tb[NDA_MASTER])
-- 
2.37.3

[PATCH iproute2-next 3/4] bridge: link: Add MAC Authentication Bypass (MAB) support

[Ido Schimmel]

From: Hans Schultz <netdev@kapio-technology.com>

Add MAB support in bridge(8) and ip(8), allowing these utilities to
enable / disable MAB and display its current status.

Signed-off-by: Hans Schultz <netdev@kapio-technology.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---

Notes:
    Changes made by me:
    * Reword commit message.
    * Reword man page.
    * Use strcmp() instead of matches().

 bridge/link.c            | 13 +++++++++++++
 ip/iplink_bridge_slave.c |  9 +++++++++
 man/man8/bridge.8        | 16 ++++++++++++++++
 man/man8/ip-link.8.in    | 18 ++++++++++++++++++
 4 files changed, 56 insertions(+)

diff --git a/bridge/link.c b/bridge/link.c
index fef3a9ef22fb..337731dff26b 100644
--- a/bridge/link.c
+++ b/bridge/link.c
@@ -184,6 +184,9 @@ static void print_protinfo(FILE *fp, struct rtattr *attr)
 		if (prtb[IFLA_BRPORT_LOCKED])
 			print_on_off(PRINT_ANY, "locked", "locked %s ",
 				     rta_getattr_u8(prtb[IFLA_BRPORT_LOCKED]));
+		if (prtb[IFLA_BRPORT_MAB])
+			print_on_off(PRINT_ANY, "mab", "mab %s ",
+				     rta_getattr_u8(prtb[IFLA_BRPORT_MAB]));
 	} else
 		print_stp_state(rta_getattr_u8(attr));
 }
@@ -283,6 +286,7 @@ static void usage(void)
 		"                               [ vlan_tunnel {on | off} ]\n"
 		"                               [ isolated {on | off} ]\n"
 		"                               [ locked {on | off} ]\n"
+		"                               [ mab {on | off} ]\n"
 		"                               [ hwmode {vepa | veb} ]\n"
 		"                               [ backup_port DEVICE ] [ nobackup_port ]\n"
 		"                               [ self ] [ master ]\n"
@@ -314,6 +318,7 @@ static int brlink_modify(int argc, char **argv)
 	__s8 bcast_flood = -1;
 	__s8 mcast_to_unicast = -1;
 	__s8 locked = -1;
+	__s8 macauth = -1;
 	__s8 isolated = -1;
 	__s8 hairpin = -1;
 	__s8 bpdu_guard = -1;
@@ -439,6 +444,11 @@ static int brlink_modify(int argc, char **argv)
 			locked = parse_on_off("locked", *argv, &ret);
 			if (ret)
 				return ret;
+		} else if (strcmp(*argv, "mab") == 0) {
+			NEXT_ARG();
+			macauth = parse_on_off("mab", *argv, &ret);
+			if (ret)
+				return ret;
 		} else if (strcmp(*argv, "backup_port") == 0) {
 			NEXT_ARG();
 			backup_port_idx = ll_name_to_index(*argv);
@@ -522,6 +532,9 @@ static int brlink_modify(int argc, char **argv)
 	if (locked >= 0)
 		addattr8(&req.n, sizeof(req), IFLA_BRPORT_LOCKED, locked);
 
+	if (macauth >= 0)
+		addattr8(&req.n, sizeof(req), IFLA_BRPORT_MAB, macauth);
+
 	if (backup_port_idx != -1)
 		addattr32(&req.n, sizeof(req), IFLA_BRPORT_BACKUP_PORT,
 			  backup_port_idx);
diff --git a/ip/iplink_bridge_slave.c b/ip/iplink_bridge_slave.c
index 98d172134847..ca4b264e64e7 100644
--- a/ip/iplink_bridge_slave.c
+++ b/ip/iplink_bridge_slave.c
@@ -44,6 +44,7 @@ static void print_explain(FILE *f)
 		"			[ vlan_tunnel {on | off} ]\n"
 		"			[ isolated {on | off} ]\n"
 		"			[ locked {on | off} ]\n"
+		"                       [ mab {on | off} ]\n"
 		"			[ backup_port DEVICE ] [ nobackup_port ]\n"
 	);
 }
@@ -288,6 +289,10 @@ static void bridge_slave_print_opt(struct link_util *lu, FILE *f,
 		print_on_off(PRINT_ANY, "locked", "locked %s ",
 			     rta_getattr_u8(tb[IFLA_BRPORT_LOCKED]));
 
+	if (tb[IFLA_BRPORT_MAB])
+		print_on_off(PRINT_ANY, "mab", "mab %s ",
+			     rta_getattr_u8(tb[IFLA_BRPORT_MAB]));
+
 	if (tb[IFLA_BRPORT_BACKUP_PORT]) {
 		int backup_p = rta_getattr_u32(tb[IFLA_BRPORT_BACKUP_PORT]);
 
@@ -411,6 +416,10 @@ static int bridge_slave_parse_opt(struct link_util *lu, int argc, char **argv,
 			NEXT_ARG();
 			bridge_slave_parse_on_off("locked", *argv, n,
 						  IFLA_BRPORT_LOCKED);
+		} else if (strcmp(*argv, "mab") == 0) {
+			NEXT_ARG();
+			bridge_slave_parse_on_off("mab", *argv, n,
+						  IFLA_BRPORT_MAB);
 		} else if (matches(*argv, "backup_port") == 0) {
 			int ifindex;
 
diff --git a/man/man8/bridge.8 b/man/man8/bridge.8
index d4df772ea3b2..1888f707b6d2 100644
--- a/man/man8/bridge.8
+++ b/man/man8/bridge.8
@@ -54,6 +54,7 @@ bridge \- show / manipulate bridge addresses and devices
 .BR vlan_tunnel " { " on " | " off " } ] [ "
 .BR isolated " { " on " | " off " } ] [ "
 .BR locked " { " on " | " off " } ] [ "
+.BR mab " { " on " | " off " } ] [ "
 .B backup_port
 .IR  DEVICE " ] ["
 .BR nobackup_port " ] [ "
@@ -580,6 +581,21 @@ The common use is that hosts are allowed access through authentication
 with the IEEE 802.1X protocol or based on whitelists or like setups.
 By default this flag is off.
 
+.TP
+.BR "mab on " or " mab off "
+Controls whether MAC Authentication Bypass (MAB) is enabled on the port or not.
+MAB can only be enabled on a locked port that has learning enabled. When
+enabled, FDB entries are learned from received traffic and have the "locked"
+FDB flag set. The flag can only be set by the kernel and it indicates that the
+FDB entry cannot be used to authenticate the corresponding host. User space can
+decide to authenticate the host by replacing the FDB entry and clearing the
+"locked" FDB flag. Locked FDB entries can roam to unlocked (authorized) ports
+in which case the "locked" flag is cleared. FDB entries cannot roam to locked
+ports regardless of MAB being enabled or not. Therefore, locked FDB entries are
+only created if an FDB entry with the given {MAC, VID} does not already exist.
+This behavior prevents unauthenticated hosts from disrupting traffic destined
+to already authenticated hosts. Locked FDB entries act like regular dynamic
+entries with respect to forwarding and aging. By default this flag is off.
 
 .TP
 .BI backup_port " DEVICE"
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index 88ad9d7baab7..314c07d0fb1f 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -2471,6 +2471,9 @@ the following additional arguments are supported:
 .BR isolated " { " on " | " off " }"
 ] [
 .BR locked " { " on " | " off " }"
+] [
+.BR mab " { " on " | " off " }"
+] [
 .BR backup_port " DEVICE"
 ] [
 .BR nobackup_port " ]"
@@ -2577,6 +2580,21 @@ default this flag is off.
 behind the port cannot communicate through the port unless a FDB entry
 representing the host is in the FDB. By default this flag is off.
 
+.BR mab " { " on " | " off " }"
+- controls whether MAC Authentication Bypass (MAB) is enabled on the port or
+not.  MAB can only be enabled on a locked port that has learning enabled. When
+enabled, FDB entries are learned from received traffic and have the "locked"
+FDB flag set. The flag can only be set by the kernel and it indicates that the
+FDB entry cannot be used to authenticate the corresponding host. User space can
+decide to authenticate the host by replacing the FDB entry and clearing the
+"locked" FDB flag. Locked FDB entries can roam to unlocked (authorized) ports
+in which case the "locked" flag is cleared. FDB entries cannot roam to locked
+ports regardless of MAB being enabled or not. Therefore, locked FDB entries are
+only created if an FDB entry with the given {MAC, VID} does not already exist.
+This behavior prevents unauthenticated hosts from disrupting traffic destined
+to already authenticated hosts. Locked FDB entries act like regular dynamic
+entries with respect to forwarding and aging. By default this flag is off.
+
 .BI backup_port " DEVICE"
 - if the port loses carrier all traffic will be redirected to the
 configured backup port
-- 
2.37.3

[PATCH iproute2-next 4/4] man: bridge: Reword description of "locked" bridge port option

[Ido Schimmel]

Adjust the description to mention the "no_linklocal_learn" bridge option
and make sure it is consistent between both the bridge(8) and ip-link(8)
man pages.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 man/man8/bridge.8     | 16 ++++++++++------
 man/man8/ip-link.8.in | 13 ++++++++++---
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/man/man8/bridge.8 b/man/man8/bridge.8
index 1888f707b6d2..e72826d750ca 100644
--- a/man/man8/bridge.8
+++ b/man/man8/bridge.8
@@ -574,12 +574,16 @@ flag is off.
 
 .TP
 .BR "locked on " or " locked off "
-Controls whether a port will be locked, meaning that hosts behind the
-port will not be able to communicate through the port unless an FDB
-entry with the units MAC address is in the FDB.
-The common use is that hosts are allowed access through authentication
-with the IEEE 802.1X protocol or based on whitelists or like setups.
-By default this flag is off.
+Controls whether a port is locked or not. When locked, non-link-local frames
+received through the port are dropped unless an FDB entry with the MAC source
+address points to the port. The common use case is IEEE 802.1X where hosts can
+authenticate themselves by exchanging EAPOL frames with an authenticator. After
+authentication is complete, the user space control plane can install a matching
+FDB entry to allow traffic from the host to be forwarded by the bridge. When
+learning is enabled on a locked port, the
+.B no_linklocal_learn
+bridge option needs to be on to prevent the bridge from learning from received
+EAPOL frames. By default this flag is off.
 
 .TP
 .BR "mab on " or " mab off "
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index 314c07d0fb1f..235c839a417c 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -2576,9 +2576,16 @@ is enabled on the port. By default this flag is off.
 default this flag is off.
 
 .BR locked " { " on " | " off " }"
-- sets or unsets a port in locked mode, so that when enabled, hosts
-behind the port cannot communicate through the port unless a FDB entry
-representing the host is in the FDB. By default this flag is off.
+- controls whether a port is locked or not. When locked, non-link-local frames
+received through the port are dropped unless an FDB entry with the MAC source
+address points to the port. The common use case is IEEE 802.1X where hosts can
+authenticate themselves by exchanging EAPOL frames with an authenticator. After
+authentication is complete, the user space control plane can install a matching
+FDB entry to allow traffic from the host to be forwarded by the bridge. When
+learning is enabled on a locked port, the
+.B no_linklocal_learn
+bridge option needs to be on to prevent the bridge from learning from received
+EAPOL frames. By default this flag is off.
 
 .BR mab " { " on " | " off " }"
 - controls whether MAC Authentication Bypass (MAB) is enabled on the port or
-- 
2.37.3

Re: [PATCH iproute2-next 0/4] bridge: Add MAC Authentication Bypass (MAB) support

[patchwork-bot+netdevbpf]

Hello:

This series was applied to iproute2/iproute2-next.git (main)
by David Ahern <dsahern@kernel.org>:

On Sun,  6 Nov 2022 13:39:53 +0200 you wrote:
> Add MAB support in iproute2, allowing it to enable / disable MAB on a
> bridge port and display the "locked" FDB flag.
> 
> Patch #1 syncs the kernel headers.
> 
> Patch #2 extends iproute2 to display the "locked" FDB flag when it is
> set.
> 
> [...]

Here is the summary with links:
  - [iproute2-next,1/4] Sync kernel headers
    (no matching commit)
  - [iproute2-next,2/4] bridge: fdb: Add support for locked FDB entries
    https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=fa24597472f3
  - [iproute2-next,3/4] bridge: link: Add MAC Authentication Bypass (MAB) support
    https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=05f1164fe811
  - [iproute2-next,4/4] man: bridge: Reword description of "locked" bridge port option
    https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=34c4cb13a059

You are awesome, thank you!
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