thr3ads.net - Linux Ethernet Bridging - [Bridge] [PATCH v3 net-next 03/14] net: bridge: mst: Support setting and reporting MST port states [Mar 2022]

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Tobias Waldekranz

2022-Mar-14 09:52 UTC

[Bridge] [PATCH v3 net-next 03/14] net: bridge: mst: Support setting and reporting MST port states

Make it possible to change the port state in a given MSTI by extending
the bridge port netlink interface (RTM_SETLINK on PF_BRIDGE).The
proposed iproute2 interface would be:

    bridge mst set dev <PORT> msti <MSTI> state <STATE>

Current states in all applicable MSTIs can also be dumped via a
corresponding RTM_GETLINK. The proposed iproute interface looks like
this:

$ bridge mst
port              msti
vb1               0
		    state forwarding
		  100
		    state disabled
vb2               0
		    state forwarding
		  100
		    state forwarding

The preexisting per-VLAN states are still valid in the MST
mode (although they are read-only), and can be queried as usual if one
is interested in knowing a particular VLAN's state without having to
care about the VID to MSTI mapping (in this example VLAN 20 and 30 are
bound to MSTI 100):

$ bridge -d vlan
port              vlan-id
vb1               10
		    state forwarding mcast_router 1
		  20
		    state disabled mcast_router 1
		  30
		    state disabled mcast_router 1
		  40
		    state forwarding mcast_router 1
vb2               10
		    state forwarding mcast_router 1
		  20
		    state forwarding mcast_router 1
		  30
		    state forwarding mcast_router 1
		  40
		    state forwarding mcast_router 1

Signed-off-by: Tobias Waldekranz <tobias at waldekranz.com>
---
 include/uapi/linux/if_bridge.h |  17 ++++++
 include/uapi/linux/rtnetlink.h |   1 +
 net/bridge/br_mst.c            | 105 +++++++++++++++++++++++++++++++++
 net/bridge/br_netlink.c        |  32 +++++++++-
 net/bridge/br_private.h        |  15 +++++
 5 files changed, 169 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index f60244b747ae..879dfaef8da0 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -122,6 +122,7 @@ enum {
 	IFLA_BRIDGE_VLAN_TUNNEL_INFO,
 	IFLA_BRIDGE_MRP,
 	IFLA_BRIDGE_CFM,
+	IFLA_BRIDGE_MST,
 	__IFLA_BRIDGE_MAX,
 };
 #define IFLA_BRIDGE_MAX (__IFLA_BRIDGE_MAX - 1)
@@ -453,6 +454,21 @@ enum {
 
 #define IFLA_BRIDGE_CFM_CC_PEER_STATUS_MAX
(__IFLA_BRIDGE_CFM_CC_PEER_STATUS_MAX - 1)
 
+enum {
+	IFLA_BRIDGE_MST_UNSPEC,
+	IFLA_BRIDGE_MST_ENTRY,
+	__IFLA_BRIDGE_MST_MAX,
+};
+#define IFLA_BRIDGE_MST_MAX (__IFLA_BRIDGE_MST_MAX - 1)
+
+enum {
+	IFLA_BRIDGE_MST_ENTRY_UNSPEC,
+	IFLA_BRIDGE_MST_ENTRY_MSTI,
+	IFLA_BRIDGE_MST_ENTRY_STATE,
+	__IFLA_BRIDGE_MST_ENTRY_MAX,
+};
+#define IFLA_BRIDGE_MST_ENTRY_MAX (__IFLA_BRIDGE_MST_ENTRY_MAX - 1)
+
 struct bridge_stp_xstats {
 	__u64 transition_blk;
 	__u64 transition_fwd;
@@ -786,4 +802,5 @@ enum {
 	__BRIDGE_QUERIER_MAX
 };
 #define BRIDGE_QUERIER_MAX (__BRIDGE_QUERIER_MAX - 1)
+
 #endif /* _UAPI_LINUX_IF_BRIDGE_H */
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 51530aade46e..83849a37db5b 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -817,6 +817,7 @@ enum {
 #define RTEXT_FILTER_MRP	(1 << 4)
 #define RTEXT_FILTER_CFM_CONFIG	(1 << 5)
 #define RTEXT_FILTER_CFM_STATUS	(1 << 6)
+#define RTEXT_FILTER_MST	(1 << 7)
 
 /* End of information exported to user level */
 
diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
index 78ef5fea4d2b..df65aa7701c1 100644
--- a/net/bridge/br_mst.c
+++ b/net/bridge/br_mst.c
@@ -124,3 +124,108 @@ int br_mst_set_enabled(struct net_bridge *br, bool on,
 	br_opt_toggle(br, BROPT_MST_ENABLED, on);
 	return 0;
 }
+
+int br_mst_fill_info(struct sk_buff *skb, struct net_bridge_vlan_group *vg)
+{
+	struct net_bridge_vlan *v;
+	struct nlattr *nest;
+	unsigned long *seen;
+	int err = 0;
+
+	seen = bitmap_zalloc(VLAN_N_VID, 0);
+	if (!seen)
+		return -ENOMEM;
+
+	list_for_each_entry(v, &vg->vlan_list, vlist) {
+		if (test_bit(v->brvlan->msti, seen))
+			continue;
+
+		nest = nla_nest_start_noflag(skb, IFLA_BRIDGE_MST_ENTRY);
+		if (!nest ||
+		    nla_put_u16(skb, IFLA_BRIDGE_MST_ENTRY_MSTI, v->brvlan->msti) ||
+		    nla_put_u8(skb, IFLA_BRIDGE_MST_ENTRY_STATE, v->state)) {
+			err = -EMSGSIZE;
+			break;
+		}
+		nla_nest_end(skb, nest);
+
+		set_bit(v->brvlan->msti, seen);
+	}
+
+	kfree(seen);
+	return err;
+}
+
+static const struct nla_policy br_mst_nl_policy[IFLA_BRIDGE_MST_ENTRY_MAX + 1]
= {
+	[IFLA_BRIDGE_MST_ENTRY_MSTI] = NLA_POLICY_RANGE(NLA_U16,
+						   1, /* 0 reserved for CST */
+						   VLAN_N_VID - 1),
+	[IFLA_BRIDGE_MST_ENTRY_STATE] = NLA_POLICY_RANGE(NLA_U8,
+						    BR_STATE_DISABLED,
+						    BR_STATE_BLOCKING),
+};
+
+static int br_mst_parse_one(struct net_bridge_port *p,
+			    const struct nlattr *attr,
+			    struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[IFLA_BRIDGE_MST_ENTRY_MAX + 1];
+	u16 msti;
+	u8 state;
+	int err;
+
+	err = nla_parse_nested(tb, IFLA_BRIDGE_MST_ENTRY_MAX, attr,
+			       br_mst_nl_policy, extack);
+	if (err)
+		return err;
+
+	if (!tb[IFLA_BRIDGE_MST_ENTRY_MSTI]) {
+		NL_SET_ERR_MSG_MOD(extack, "MSTI not specified");
+		return -EINVAL;
+	}
+
+	if (!tb[IFLA_BRIDGE_MST_ENTRY_STATE]) {
+		NL_SET_ERR_MSG_MOD(extack, "State not specified");
+		return -EINVAL;
+	}
+
+	msti = nla_get_u16(tb[IFLA_BRIDGE_MST_ENTRY_MSTI]);
+	state = nla_get_u8(tb[IFLA_BRIDGE_MST_ENTRY_STATE]);
+
+	br_mst_set_state(p, msti, state);
+	return 0;
+}
+
+int br_mst_parse(struct net_bridge_port *p, struct nlattr *mst_attr,
+		 struct netlink_ext_ack *extack)
+{
+	struct nlattr *attr;
+	int err, msts = 0;
+	int rem;
+
+	if (!br_opt_get(p->br, BROPT_MST_ENABLED)) {
+		NL_SET_ERR_MSG_MOD(extack, "Can't modify MST state when MST is
disabled");
+		return -EBUSY;
+	}
+
+	nla_for_each_nested(attr, mst_attr, rem) {
+		switch (nla_type(attr)) {
+		case IFLA_BRIDGE_MST_ENTRY:
+			err = br_mst_parse_one(p, attr, extack);
+			break;
+		default:
+			continue;
+		}
+
+		msts++;
+		if (err)
+			break;
+	}
+
+	if (!msts) {
+		NL_SET_ERR_MSG_MOD(extack, "Found no MST entries to process");
+		err = -EINVAL;
+	}
+
+	return err;
+}
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 7d4432ca9a20..d2b4550f30d6 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -485,7 +485,8 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 			   RTEXT_FILTER_BRVLAN_COMPRESSED |
 			   RTEXT_FILTER_MRP |
 			   RTEXT_FILTER_CFM_CONFIG |
-			   RTEXT_FILTER_CFM_STATUS)) {
+			   RTEXT_FILTER_CFM_STATUS |
+			   RTEXT_FILTER_MST)) {
 		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
 		if (!af)
 			goto nla_put_failure;
@@ -564,7 +565,28 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 		nla_nest_end(skb, cfm_nest);
 	}
 
+	if ((filter_mask & RTEXT_FILTER_MST) &&
+	    br_opt_get(br, BROPT_MST_ENABLED) && port) {
+		struct net_bridge_vlan_group *vg = nbp_vlan_group(port);
+		struct nlattr *mst_nest;
+		int err;
+
+		if (!vg || !vg->num_vlans)
+			goto done;
+
+		mst_nest = nla_nest_start(skb, IFLA_BRIDGE_MST);
+		if (!mst_nest)
+			goto nla_put_failure;
+
+		err = br_mst_fill_info(skb, vg);
+		if (err)
+			goto nla_put_failure;
+
+		nla_nest_end(skb, mst_nest);
+	}
+
 done:
+
 	if (af)
 		nla_nest_end(skb, af);
 	nlmsg_end(skb, nlh);
@@ -803,6 +825,14 @@ static int br_afspec(struct net_bridge *br,
 			if (err)
 				return err;
 			break;
+		case IFLA_BRIDGE_MST:
+			if (cmd != RTM_SETLINK || !p)
+				return -EINVAL;
+
+			err = br_mst_parse(p, attr, extack);
+			if (err)
+				return err;
+			break;
 		}
 	}
 
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index b907d389b63a..08d82578bd97 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1783,6 +1783,9 @@ int br_mst_vlan_set_msti(struct net_bridge_vlan *v, u16
msti);
 void br_mst_vlan_init_state(struct net_bridge_vlan *v);
 int br_mst_set_enabled(struct net_bridge *br, bool on,
 		       struct netlink_ext_ack *extack);
+int br_mst_fill_info(struct sk_buff *skb, struct net_bridge_vlan_group *vg);
+int br_mst_parse(struct net_bridge_port *p, struct nlattr *mst_attr,
+		 struct netlink_ext_ack *extack);
 #else
 static inline bool br_mst_is_enabled(struct net_bridge *br)
 {
@@ -1791,6 +1794,18 @@ static inline bool br_mst_is_enabled(struct net_bridge
*br)
 
 static inline void br_mst_set_state(struct net_bridge_port *p,
 				    u16 msti, u8 state) {}
+static inline int br_mst_fill_info(struct sk_buff *skb,
+				   struct net_bridge_vlan_group *vg)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int br_mst_parse(struct net_bridge_port *p,
+			       struct nlattr *mst_attr,
+			       struct netlink_ext_ack *extack)
+{
+	return -EOPNOTSUPP;
+}
 #endif
 
 struct nf_br_ops {
-- 
2.25.1

Nikolay Aleksandrov

2022-Mar-14 10:37 UTC

head link

[Bridge] [PATCH v3 net-next 03/14] net: bridge: mst: Support setting and reporting MST port states

On 14/03/2022 11:52, Tobias Waldekranz wrote:> Make it possible to change the port state in a given MSTI by extending
> the bridge port netlink interface (RTM_SETLINK on PF_BRIDGE).The
> proposed iproute2 interface would be:
> 
>     bridge mst set dev <PORT> msti <MSTI> state <STATE>
> 
> Current states in all applicable MSTIs can also be dumped via a
> corresponding RTM_GETLINK. The proposed iproute interface looks like
> this:
> 
> $ bridge mst
> port              msti
> vb1               0
> 		    state forwarding
> 		  100
> 		    state disabled
> vb2               0
> 		    state forwarding
> 		  100
> 		    state forwarding
> 
> The preexisting per-VLAN states are still valid in the MST
> mode (although they are read-only), and can be queried as usual if one
> is interested in knowing a particular VLAN's state without having to
> care about the VID to MSTI mapping (in this example VLAN 20 and 30 are
> bound to MSTI 100):
> 
> $ bridge -d vlan
> port              vlan-id
> vb1               10
> 		    state forwarding mcast_router 1
> 		  20
> 		    state disabled mcast_router 1
> 		  30
> 		    state disabled mcast_router 1
> 		  40
> 		    state forwarding mcast_router 1
> vb2               10
> 		    state forwarding mcast_router 1
> 		  20
> 		    state forwarding mcast_router 1
> 		  30
> 		    state forwarding mcast_router 1
> 		  40
> 		    state forwarding mcast_router 1
> 
> Signed-off-by: Tobias Waldekranz <tobias at waldekranz.com>
> ---
Hi Tobias,
A few comments below..
>  include/uapi/linux/if_bridge.h |  17 ++++++
>  include/uapi/linux/rtnetlink.h |   1 +
>  net/bridge/br_mst.c            | 105 +++++++++++++++++++++++++++++++++
>  net/bridge/br_netlink.c        |  32 +++++++++-
>  net/bridge/br_private.h        |  15 +++++
>  5 files changed, 169 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uapi/linux/if_bridge.h
b/include/uapi/linux/if_bridge.h
> index f60244b747ae..879dfaef8da0 100644
> --- a/include/uapi/linux/if_bridge.h
> +++ b/include/uapi/linux/if_bridge.h
> @@ -122,6 +122,7 @@ enum {
>  	IFLA_BRIDGE_VLAN_TUNNEL_INFO,
>  	IFLA_BRIDGE_MRP,
>  	IFLA_BRIDGE_CFM,
> +	IFLA_BRIDGE_MST,
>  	__IFLA_BRIDGE_MAX,
>  };
>  #define IFLA_BRIDGE_MAX (__IFLA_BRIDGE_MAX - 1)
> @@ -453,6 +454,21 @@ enum {
>  
>  #define IFLA_BRIDGE_CFM_CC_PEER_STATUS_MAX
(__IFLA_BRIDGE_CFM_CC_PEER_STATUS_MAX - 1)
>  
> +enum {
> +	IFLA_BRIDGE_MST_UNSPEC,
> +	IFLA_BRIDGE_MST_ENTRY,
> +	__IFLA_BRIDGE_MST_MAX,
> +};
> +#define IFLA_BRIDGE_MST_MAX (__IFLA_BRIDGE_MST_MAX - 1)
> +
> +enum {
> +	IFLA_BRIDGE_MST_ENTRY_UNSPEC,
> +	IFLA_BRIDGE_MST_ENTRY_MSTI,
> +	IFLA_BRIDGE_MST_ENTRY_STATE,
> +	__IFLA_BRIDGE_MST_ENTRY_MAX,
> +};
> +#define IFLA_BRIDGE_MST_ENTRY_MAX (__IFLA_BRIDGE_MST_ENTRY_MAX - 1)
> +
>  struct bridge_stp_xstats {
>  	__u64 transition_blk;
>  	__u64 transition_fwd;
> @@ -786,4 +802,5 @@ enum {
>  	__BRIDGE_QUERIER_MAX
>  };
>  #define BRIDGE_QUERIER_MAX (__BRIDGE_QUERIER_MAX - 1)
> +
stray new line
>  #endif /* _UAPI_LINUX_IF_BRIDGE_H */
> diff --git a/include/uapi/linux/rtnetlink.h
b/include/uapi/linux/rtnetlink.h
> index 51530aade46e..83849a37db5b 100644
> --- a/include/uapi/linux/rtnetlink.h
> +++ b/include/uapi/linux/rtnetlink.h
> @@ -817,6 +817,7 @@ enum {
>  #define RTEXT_FILTER_MRP	(1 << 4)
>  #define RTEXT_FILTER_CFM_CONFIG	(1 << 5)
>  #define RTEXT_FILTER_CFM_STATUS	(1 << 6)
> +#define RTEXT_FILTER_MST	(1 << 7)
>  
>  /* End of information exported to user level */
>  
> diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
> index 78ef5fea4d2b..df65aa7701c1 100644
> --- a/net/bridge/br_mst.c
> +++ b/net/bridge/br_mst.c
> @@ -124,3 +124,108 @@ int br_mst_set_enabled(struct net_bridge *br, bool
on,
>  	br_opt_toggle(br, BROPT_MST_ENABLED, on);
>  	return 0;
>  }
> +
> +int br_mst_fill_info(struct sk_buff *skb, struct net_bridge_vlan_group
*vg)
const vg
> +{
> +	struct net_bridge_vlan *v;
const v
> +	struct nlattr *nest;
> +	unsigned long *seen;
> +	int err = 0;
> +
> +	seen = bitmap_zalloc(VLAN_N_VID, 0);
> +	if (!seen)
> +		return -ENOMEM;
> +
> +	list_for_each_entry(v, &vg->vlan_list, vlist) {
> +		if (test_bit(v->brvlan->msti, seen))
> +			continue;
> +
> +		nest = nla_nest_start_noflag(skb, IFLA_BRIDGE_MST_ENTRY);
> +		if (!nest ||
> +		    nla_put_u16(skb, IFLA_BRIDGE_MST_ENTRY_MSTI, v->brvlan->msti)
||
> +		    nla_put_u8(skb, IFLA_BRIDGE_MST_ENTRY_STATE, v->state)) {
> +			err = -EMSGSIZE;
> +			break;
> +		}
> +		nla_nest_end(skb, nest);
> +
> +		set_bit(v->brvlan->msti, seen);
__set_bit()
> +	}
> +
> +	kfree(seen);
> +	return err;
> +}
> +
> +static const struct nla_policy br_mst_nl_policy[IFLA_BRIDGE_MST_ENTRY_MAX
+ 1] = {
> +	[IFLA_BRIDGE_MST_ENTRY_MSTI] = NLA_POLICY_RANGE(NLA_U16,
> +						   1, /* 0 reserved for CST */
> +						   VLAN_N_VID - 1),
> +	[IFLA_BRIDGE_MST_ENTRY_STATE] = NLA_POLICY_RANGE(NLA_U8,
> +						    BR_STATE_DISABLED,
> +						    BR_STATE_BLOCKING),
> +};
> +
> +static int br_mst_parse_one(struct net_bridge_port *p,
> +			    const struct nlattr *attr,
> +			    struct netlink_ext_ack *extack)
> +{
I'd either set the state after parsing, so this function just does what it
says (parse) or I'd rename it.
> +	struct nlattr *tb[IFLA_BRIDGE_MST_ENTRY_MAX + 1];
> +	u16 msti;
> +	u8 state;
> +	int err;
> +
> +	err = nla_parse_nested(tb, IFLA_BRIDGE_MST_ENTRY_MAX, attr,
> +			       br_mst_nl_policy, extack);
> +	if (err)
> +		return err;
> +
> +	if (!tb[IFLA_BRIDGE_MST_ENTRY_MSTI]) {
> +		NL_SET_ERR_MSG_MOD(extack, "MSTI not specified");
> +		return -EINVAL;
> +	}
> +
> +	if (!tb[IFLA_BRIDGE_MST_ENTRY_STATE]) {
> +		NL_SET_ERR_MSG_MOD(extack, "State not specified");
> +		return -EINVAL;
> +	}
> +
> +	msti = nla_get_u16(tb[IFLA_BRIDGE_MST_ENTRY_MSTI]);
> +	state = nla_get_u8(tb[IFLA_BRIDGE_MST_ENTRY_STATE]);
> +
> +	br_mst_set_state(p, msti, state);
> +	return 0;
> +}
> +
> +int br_mst_parse(struct net_bridge_port *p, struct nlattr *mst_attr,
> +		 struct netlink_ext_ack *extack)
This doesn't just parse though, it also sets the state. Please rename it to
something more appropriate.

const mst_attr
> +{
> +	struct nlattr *attr;
> +	int err, msts = 0;
> +	int rem;
> +
> +	if (!br_opt_get(p->br, BROPT_MST_ENABLED)) {
> +		NL_SET_ERR_MSG_MOD(extack, "Can't modify MST state when MST is
disabled");
> +		return -EBUSY;
> +	}
> +
> +	nla_for_each_nested(attr, mst_attr, rem) {
> +		switch (nla_type(attr)) {
> +		case IFLA_BRIDGE_MST_ENTRY:
> +			err = br_mst_parse_one(p, attr, extack);
> +			break;
> +		default:
> +			continue;
> +		}
> +
> +		msts++;
> +		if (err)
> +			break;
> +	}
> +
> +	if (!msts) {
> +		NL_SET_ERR_MSG_MOD(extack, "Found no MST entries to process");
> +		err = -EINVAL;
> +	}
> +
> +	return err;
> +}
> diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
> index 7d4432ca9a20..d2b4550f30d6 100644
> --- a/net/bridge/br_netlink.c
> +++ b/net/bridge/br_netlink.c
> @@ -485,7 +485,8 @@ static int br_fill_ifinfo(struct sk_buff *skb,
>  			   RTEXT_FILTER_BRVLAN_COMPRESSED |
>  			   RTEXT_FILTER_MRP |
>  			   RTEXT_FILTER_CFM_CONFIG |
> -			   RTEXT_FILTER_CFM_STATUS)) {
> +			   RTEXT_FILTER_CFM_STATUS |
> +			   RTEXT_FILTER_MST)) {
>  		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
>  		if (!af)
>  			goto nla_put_failure;
> @@ -564,7 +565,28 @@ static int br_fill_ifinfo(struct sk_buff *skb,
>  		nla_nest_end(skb, cfm_nest);
>  	}
>  
> +	if ((filter_mask & RTEXT_FILTER_MST) &&
> +	    br_opt_get(br, BROPT_MST_ENABLED) && port) {
> +		struct net_bridge_vlan_group *vg = nbp_vlan_group(port);
const vg
> +		struct nlattr *mst_nest;
> +		int err;
> +
> +		if (!vg || !vg->num_vlans)
> +			goto done;
> +
> +		mst_nest = nla_nest_start(skb, IFLA_BRIDGE_MST);
> +		if (!mst_nest)
> +			goto nla_put_failure;
> +
> +		err = br_mst_fill_info(skb, vg);
> +		if (err)
> +			goto nla_put_failure;
> +
> +		nla_nest_end(skb, mst_nest);
> +	}
> +
I think you should also update br_get_link_af_size_filtered() to account for the
new dump attributes based on the filter. I'd adjust vinfo_sz based on the
filter
flag.
>  done:
> +
>  	if (af)
>  		nla_nest_end(skb, af);
>  	nlmsg_end(skb, nlh);
> @@ -803,6 +825,14 @@ static int br_afspec(struct net_bridge *br,
>  			if (err)
>  				return err;
>  			break;
> +		case IFLA_BRIDGE_MST:
> +			if (cmd != RTM_SETLINK || !p)
> +				return -EINVAL;
These are two different errors, please set extack appropriately
for each error.
> +
> +			err = br_mst_parse(p, attr, extack);
> +			if (err)
> +				return err;
> +			break;
>  		}
>  	}
>  
> diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
> index b907d389b63a..08d82578bd97 100644
> --- a/net/bridge/br_private.h
> +++ b/net/bridge/br_private.h
> @@ -1783,6 +1783,9 @@ int br_mst_vlan_set_msti(struct net_bridge_vlan *v,
u16 msti);
>  void br_mst_vlan_init_state(struct net_bridge_vlan *v);
>  int br_mst_set_enabled(struct net_bridge *br, bool on,
>  		       struct netlink_ext_ack *extack);
> +int br_mst_fill_info(struct sk_buff *skb, struct net_bridge_vlan_group
*vg);
> +int br_mst_parse(struct net_bridge_port *p, struct nlattr *mst_attr,
> +		 struct netlink_ext_ack *extack);
>  #else
>  static inline bool br_mst_is_enabled(struct net_bridge *br)
>  {
> @@ -1791,6 +1794,18 @@ static inline bool br_mst_is_enabled(struct
net_bridge *br)
>  
>  static inline void br_mst_set_state(struct net_bridge_port *p,
>  				    u16 msti, u8 state) {}
> +static inline int br_mst_fill_info(struct sk_buff *skb,
> +				   struct net_bridge_vlan_group *vg)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
> +static inline int br_mst_parse(struct net_bridge_port *p,
> +			       struct nlattr *mst_attr,
> +			       struct netlink_ext_ack *extack)
> +{
> +	return -EOPNOTSUPP;
> +}
>  #endif
>  
>  struct nf_br_ops {

Vladimir Oltean

2022-Mar-14 14:58 UTC

head link

[Bridge] [PATCH v3 net-next 03/14] net: bridge: mst: Support setting and reporting MST port states

On Mon, Mar 14, 2022 at 10:52:20AM +0100, Tobias Waldekranz
wrote:> +int br_mst_fill_info(struct sk_buff *skb, struct net_bridge_vlan_group
*vg)
> +{
> +	struct net_bridge_vlan *v;
> +	struct nlattr *nest;
> +	unsigned long *seen;
> +	int err = 0;
> +
> +	seen = bitmap_zalloc(VLAN_N_VID, 0);
I see there is precedent in the bridge driver for using dynamic
allocation as opposed to on-stack declaration using DECLARE_BITMAP().
I imagine this isn't just to be "heapsters", but why?

I don't have a very good sense of how much on-stack memory is too much
(a lot probably depends on the expected depth of the call stack too, and here it
doesn't appear to be too deep), but I see that
mlxsw_sp_bridge_vxlan_vlan_is_valid()
has a DECLARE_BITMAP(vlans, VLAN_N_VID) too.

The comment applies for callers of br_mst_get_info() too.
> +	if (!seen)
> +		return -ENOMEM;
> +
> +	list_for_each_entry(v, &vg->vlan_list, vlist) {
> +		if (test_bit(v->brvlan->msti, seen))
> +			continue;
> +
> +		nest = nla_nest_start_noflag(skb, IFLA_BRIDGE_MST_ENTRY);
> +		if (!nest ||
> +		    nla_put_u16(skb, IFLA_BRIDGE_MST_ENTRY_MSTI, v->brvlan->msti)
||
> +		    nla_put_u8(skb, IFLA_BRIDGE_MST_ENTRY_STATE, v->state)) {
> +			err = -EMSGSIZE;
> +			break;
> +		}
> +		nla_nest_end(skb, nest);
> +
> +		set_bit(v->brvlan->msti, seen);
> +	}
> +
> +	kfree(seen);
> +	return err;
> +}

Linux Ethernet Bridging - Mar 2022 - [Bridge] [PATCH v3 net-next 03/14] net: bridge: mst: Support setting and reporting MST port states

[Bridge] [PATCH v3 net-next 03/14] net: bridge: mst: Support setting and reporting MST port states

[Bridge] [PATCH v3 net-next 03/14] net: bridge: mst: Support setting and reporting MST port states

[Bridge] [PATCH v3 net-next 03/14] net: bridge: mst: Support setting and reporting MST port states