diff mbox series

[net-next,1/3] rtnetlink: add ndo_fdb_dump_context

Message ID 20241207162248.18536-2-edumazet@google.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series net: prepare for removal of net->dev_index_head | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 17 this patch: 17
netdev/build_tools success Errors and warnings before: 0 (+23) this patch: 0 (+23)
netdev/cc_maintainers warning 9 maintainers not CCed: ioana.ciornei@nxp.com menglong8.dong@gmail.com bridge@lists.linux.dev alexandre.belloni@bootlin.com razor@blackwall.org UNGLinuxDriver@microchip.com andrew+netdev@lunn.ch vladimir.oltean@nxp.com claudiu.manoil@nxp.com
netdev/build_clang success Errors and warnings before: 47 this patch: 47
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 3531 this patch: 3531
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 154 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 6 this patch: 6
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-12-09--09-01 (tests: 762)

Commit Message

Eric Dumazet Dec. 7, 2024, 4:22 p.m. UTC 
rtnl_fdb_dump() and various ndo_fdb_dump() helpers share
a hidden layout of cb->ctx.

Before switching rtnl_fdb_dump() to for_each_netdev_dump()
in the following patch, make this more explicit.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 .../ethernet/freescale/dpaa2/dpaa2-switch.c   |  3 ++-
 drivers/net/ethernet/mscc/ocelot_net.c        |  3 ++-
 drivers/net/vxlan/vxlan_core.c                |  5 ++--
 include/linux/rtnetlink.h                     |  7 ++++++
 net/bridge/br_fdb.c                           |  3 ++-
 net/core/rtnetlink.c                          | 24 +++++++++----------
 net/dsa/user.c                                |  3 ++-
 7 files changed, 30 insertions(+), 18 deletions(-)

Comments

Ido Schimmel Dec. 8, 2024, 5:57 p.m. UTC | #1 
On Sat, Dec 07, 2024 at 04:22:46PM +0000, Eric Dumazet wrote:
> rtnl_fdb_dump() and various ndo_fdb_dump() helpers share
> a hidden layout of cb->ctx.
> 
> Before switching rtnl_fdb_dump() to for_each_netdev_dump()
> in the following patch, make this more explicit.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>

A couple of nits in case you have v2

> ---
>  .../ethernet/freescale/dpaa2/dpaa2-switch.c   |  3 ++-
>  drivers/net/ethernet/mscc/ocelot_net.c        |  3 ++-
>  drivers/net/vxlan/vxlan_core.c                |  5 ++--
>  include/linux/rtnetlink.h                     |  7 ++++++
>  net/bridge/br_fdb.c                           |  3 ++-
>  net/core/rtnetlink.c                          | 24 +++++++++----------
>  net/dsa/user.c                                |  3 ++-
>  7 files changed, 30 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
> index a293b08f36d46dfde7e25412951da78c15e2dfd6..de383e6c6d523f01f02cb3c3977b1c448a3ac9a7 100644
> --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
> +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
> @@ -781,12 +781,13 @@ static int dpaa2_switch_fdb_dump_nl(struct fdb_dump_entry *entry,
>  				    struct ethsw_dump_ctx *dump)
>  {
>  	int is_dynamic = entry->type & DPSW_FDB_ENTRY_DINAMIC;
> +	struct ndo_fdb_dump_context *ctx = (void *)dump->cb->ctx;

Any reason not to maintain reverse xmas tree here?

>  	u32 portid = NETLINK_CB(dump->cb->skb).portid;
>  	u32 seq = dump->cb->nlh->nlmsg_seq;
>  	struct nlmsghdr *nlh;
>  	struct ndmsg *ndm;
>  
> -	if (dump->idx < dump->cb->args[2])
> +	if (dump->idx < ctx->fdb_idx)
>  		goto skip;
>  
>  	nlh = nlmsg_put(dump->skb, portid, seq, RTM_NEWNEIGH,

[...]

> diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
> index 14b88f55192085def8f318c7913a76d5447b4975..a91dfea64724615c9db778646e52cb8573f47e06 100644
> --- a/include/linux/rtnetlink.h
> +++ b/include/linux/rtnetlink.h
> @@ -178,6 +178,13 @@ void rtnetlink_init(void);
>  void __rtnl_unlock(void);
>  void rtnl_kfree_skbs(struct sk_buff *head, struct sk_buff *tail);
>  
> +/* Shared by rtnl_fdb_dump() and various ndo_fdb_dump() helpers. */
> +struct ndo_fdb_dump_context {
> +	unsigned long s_h;
> +	unsigned long s_idx;
> +	unsigned long fdb_idx;
> +};
> +
>  extern int ndo_dflt_fdb_dump(struct sk_buff *skb,
>  			     struct netlink_callback *cb,
>  			     struct net_device *dev,
> diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
> index 82bac2426631bcea63ea834e72f074fa2eaf0cee..902694c0ce643ec448978e4c4625692ccb1facd9 100644
> --- a/net/bridge/br_fdb.c
> +++ b/net/bridge/br_fdb.c
> @@ -955,6 +955,7 @@ int br_fdb_dump(struct sk_buff *skb,
>  		struct net_device *filter_dev,
>  		int *idx)
>  {
> +	struct ndo_fdb_dump_context *ctx = (void *)cb->ctx;
>  	struct net_bridge *br = netdev_priv(dev);
>  	struct net_bridge_fdb_entry *f;
>  	int err = 0;

Unlikely that the context will ever grow past 48 bytes, but might be
worthwhile to add:

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index cdedb46edc2f..8fe252c298a2 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -4919,6 +4919,8 @@ static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	int fidx = 0;
 	int err;
 
+	NL_ASSERT_CTX_FITS(struct ndo_fdb_dump_context);
+
 	if (cb->strict_check)
 		err = valid_fdb_dump_strict(cb->nlh, &br_idx, &brport_idx,
 					    cb->extack);
Kuniyuki Iwashima Dec. 9, 2024, 5:48 a.m. UTC | #2 
From: Eric Dumazet <edumazet@google.com>
Date: Sat,  7 Dec 2024 16:22:46 +0000
> rtnl_fdb_dump() and various ndo_fdb_dump() helpers share
> a hidden layout of cb->ctx.
> 
> Before switching rtnl_fdb_dump() to for_each_netdev_dump()
> in the following patch, make this more explicit.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Eric Dumazet Dec. 9, 2024, 9:53 a.m. UTC | #3 
On Sun, Dec 8, 2024 at 6:57 PM Ido Schimmel <idosch@idosch.org> wrote:
>
> On Sat, Dec 07, 2024 at 04:22:46PM +0000, Eric Dumazet wrote:
> > rtnl_fdb_dump() and various ndo_fdb_dump() helpers share
> > a hidden layout of cb->ctx.
> >
> > Before switching rtnl_fdb_dump() to for_each_netdev_dump()
> > in the following patch, make this more explicit.
> >
> > Signed-off-by: Eric Dumazet <edumazet@google.com>
>
> Reviewed-by: Ido Schimmel <idosch@nvidia.com>
>
> A couple of nits in case you have v2
>
> > ---
> >  .../ethernet/freescale/dpaa2/dpaa2-switch.c   |  3 ++-
> >  drivers/net/ethernet/mscc/ocelot_net.c        |  3 ++-
> >  drivers/net/vxlan/vxlan_core.c                |  5 ++--
> >  include/linux/rtnetlink.h                     |  7 ++++++
> >  net/bridge/br_fdb.c                           |  3 ++-
> >  net/core/rtnetlink.c                          | 24 +++++++++----------
> >  net/dsa/user.c                                |  3 ++-
> >  7 files changed, 30 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
> > index a293b08f36d46dfde7e25412951da78c15e2dfd6..de383e6c6d523f01f02cb3c3977b1c448a3ac9a7 100644
> > --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
> > +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
> > @@ -781,12 +781,13 @@ static int dpaa2_switch_fdb_dump_nl(struct fdb_dump_entry *entry,
> >                                   struct ethsw_dump_ctx *dump)
> >  {
> >       int is_dynamic = entry->type & DPSW_FDB_ENTRY_DINAMIC;
> > +     struct ndo_fdb_dump_context *ctx = (void *)dump->cb->ctx;
>
> Any reason not to maintain reverse xmas tree here?

None, will fix in v2.

>
> >       u32 portid = NETLINK_CB(dump->cb->skb).portid;
> >       u32 seq = dump->cb->nlh->nlmsg_seq;
> >       struct nlmsghdr *nlh;
> >       struct ndmsg *ndm;
> >
> > -     if (dump->idx < dump->cb->args[2])
> > +     if (dump->idx < ctx->fdb_idx)
> >               goto skip;
> >
> >       nlh = nlmsg_put(dump->skb, portid, seq, RTM_NEWNEIGH,
>
> [...]
>
> > diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
> > index 14b88f55192085def8f318c7913a76d5447b4975..a91dfea64724615c9db778646e52cb8573f47e06 100644
> > --- a/include/linux/rtnetlink.h
> > +++ b/include/linux/rtnetlink.h
> > @@ -178,6 +178,13 @@ void rtnetlink_init(void);
> >  void __rtnl_unlock(void);
> >  void rtnl_kfree_skbs(struct sk_buff *head, struct sk_buff *tail);
> >
> > +/* Shared by rtnl_fdb_dump() and various ndo_fdb_dump() helpers. */
> > +struct ndo_fdb_dump_context {
> > +     unsigned long s_h;
> > +     unsigned long s_idx;
> > +     unsigned long fdb_idx;
> > +};
> > +
> >  extern int ndo_dflt_fdb_dump(struct sk_buff *skb,
> >                            struct netlink_callback *cb,
> >                            struct net_device *dev,
> > diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
> > index 82bac2426631bcea63ea834e72f074fa2eaf0cee..902694c0ce643ec448978e4c4625692ccb1facd9 100644
> > --- a/net/bridge/br_fdb.c
> > +++ b/net/bridge/br_fdb.c
> > @@ -955,6 +955,7 @@ int br_fdb_dump(struct sk_buff *skb,
> >               struct net_device *filter_dev,
> >               int *idx)
> >  {
> > +     struct ndo_fdb_dump_context *ctx = (void *)cb->ctx;
> >       struct net_bridge *br = netdev_priv(dev);
> >       struct net_bridge_fdb_entry *f;
> >       int err = 0;
>
> Unlikely that the context will ever grow past 48 bytes, but might be
> worthwhile to add:
>
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index cdedb46edc2f..8fe252c298a2 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -4919,6 +4919,8 @@ static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
>         int fidx = 0;
>         int err;
>
> +       NL_ASSERT_CTX_FITS(struct ndo_fdb_dump_context);
> +

Good idea, will be included in v2, thanks !
diff mbox series

Patch

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
index a293b08f36d46dfde7e25412951da78c15e2dfd6..de383e6c6d523f01f02cb3c3977b1c448a3ac9a7 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
@@ -781,12 +781,13 @@  static int dpaa2_switch_fdb_dump_nl(struct fdb_dump_entry *entry,
 				    struct ethsw_dump_ctx *dump)
 {
 	int is_dynamic = entry->type & DPSW_FDB_ENTRY_DINAMIC;
+	struct ndo_fdb_dump_context *ctx = (void *)dump->cb->ctx;
 	u32 portid = NETLINK_CB(dump->cb->skb).portid;
 	u32 seq = dump->cb->nlh->nlmsg_seq;
 	struct nlmsghdr *nlh;
 	struct ndmsg *ndm;
 
-	if (dump->idx < dump->cb->args[2])
+	if (dump->idx < ctx->fdb_idx)
 		goto skip;
 
 	nlh = nlmsg_put(dump->skb, portid, seq, RTM_NEWNEIGH,
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 558e03301aa8ed89e15c5f37d148a287feaf0018..8d48468cddd7cf91fb49ad23a5c57110900160ef 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -758,12 +758,13 @@  static int ocelot_port_fdb_do_dump(const unsigned char *addr, u16 vid,
 				   bool is_static, void *data)
 {
 	struct ocelot_dump_ctx *dump = data;
+	struct ndo_fdb_dump_context *ctx = (void *)dump->cb->ctx;
 	u32 portid = NETLINK_CB(dump->cb->skb).portid;
 	u32 seq = dump->cb->nlh->nlmsg_seq;
 	struct nlmsghdr *nlh;
 	struct ndmsg *ndm;
 
-	if (dump->idx < dump->cb->args[2])
+	if (dump->idx < ctx->fdb_idx)
 		goto skip;
 
 	nlh = nlmsg_put(dump->skb, portid, seq, RTM_NEWNEIGH,
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index b46a799bd3904c4183775cb2e86172a0b127bb4f..2cb33c2cb836cf38b6e03b8a620594aa616f00fa 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1352,6 +1352,7 @@  static int vxlan_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
 			  struct net_device *dev,
 			  struct net_device *filter_dev, int *idx)
 {
+	struct ndo_fdb_dump_context *ctx = (void *)cb->ctx;
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	unsigned int h;
 	int err = 0;
@@ -1364,7 +1365,7 @@  static int vxlan_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
 			struct vxlan_rdst *rd;
 
 			if (rcu_access_pointer(f->nh)) {
-				if (*idx < cb->args[2])
+				if (*idx < ctx->fdb_idx)
 					goto skip_nh;
 				err = vxlan_fdb_info(skb, vxlan, f,
 						     NETLINK_CB(cb->skb).portid,
@@ -1381,7 +1382,7 @@  static int vxlan_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
 			}
 
 			list_for_each_entry_rcu(rd, &f->remotes, list) {
-				if (*idx < cb->args[2])
+				if (*idx < ctx->fdb_idx)
 					goto skip;
 
 				err = vxlan_fdb_info(skb, vxlan, f,
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 14b88f55192085def8f318c7913a76d5447b4975..a91dfea64724615c9db778646e52cb8573f47e06 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -178,6 +178,13 @@  void rtnetlink_init(void);
 void __rtnl_unlock(void);
 void rtnl_kfree_skbs(struct sk_buff *head, struct sk_buff *tail);
 
+/* Shared by rtnl_fdb_dump() and various ndo_fdb_dump() helpers. */
+struct ndo_fdb_dump_context {
+	unsigned long s_h;
+	unsigned long s_idx;
+	unsigned long fdb_idx;
+};
+
 extern int ndo_dflt_fdb_dump(struct sk_buff *skb,
 			     struct netlink_callback *cb,
 			     struct net_device *dev,
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 82bac2426631bcea63ea834e72f074fa2eaf0cee..902694c0ce643ec448978e4c4625692ccb1facd9 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -955,6 +955,7 @@  int br_fdb_dump(struct sk_buff *skb,
 		struct net_device *filter_dev,
 		int *idx)
 {
+	struct ndo_fdb_dump_context *ctx = (void *)cb->ctx;
 	struct net_bridge *br = netdev_priv(dev);
 	struct net_bridge_fdb_entry *f;
 	int err = 0;
@@ -970,7 +971,7 @@  int br_fdb_dump(struct sk_buff *skb,
 
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
-		if (*idx < cb->args[2])
+		if (*idx < ctx->fdb_idx)
 			goto skip;
 		if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
 			if (filter_dev != dev)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index ab5f201bf0ab41b463175f501e8560b4d64d9b0a..02791328102e7590465aab9ab949af093721b256 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -4762,15 +4762,16 @@  static int nlmsg_populate_fdb(struct sk_buff *skb,
 			      int *idx,
 			      struct netdev_hw_addr_list *list)
 {
+	struct ndo_fdb_dump_context *ctx = (void *)cb->ctx;
 	struct netdev_hw_addr *ha;
-	int err;
 	u32 portid, seq;
+	int err;
 
 	portid = NETLINK_CB(cb->skb).portid;
 	seq = cb->nlh->nlmsg_seq;
 
 	list_for_each_entry(ha, &list->list, list) {
-		if (*idx < cb->args[2])
+		if (*idx < ctx->fdb_idx)
 			goto skip;
 
 		err = nlmsg_populate_fdb_fill(skb, dev, ha->addr, 0,
@@ -4909,10 +4910,9 @@  static int valid_fdb_dump_legacy(const struct nlmsghdr *nlh,
 
 static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
-	struct net_device *dev;
-	struct net_device *br_dev = NULL;
-	const struct net_device_ops *ops = NULL;
-	const struct net_device_ops *cops = NULL;
+	const struct net_device_ops *ops = NULL, *cops = NULL;
+	struct ndo_fdb_dump_context *ctx = (void *)cb->ctx;
+	struct net_device *dev, *br_dev = NULL;
 	struct net *net = sock_net(skb->sk);
 	struct hlist_head *head;
 	int brport_idx = 0;
@@ -4939,8 +4939,8 @@  static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 		ops = br_dev->netdev_ops;
 	}
 
-	s_h = cb->args[0];
-	s_idx = cb->args[1];
+	s_h = ctx->s_h;
+	s_idx = ctx->s_idx;
 
 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
 		idx = 0;
@@ -4992,7 +4992,7 @@  static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 			cops = NULL;
 
 			/* reset fdb offset to 0 for rest of the interfaces */
-			cb->args[2] = 0;
+			ctx->fdb_idx = 0;
 			fidx = 0;
 cont:
 			idx++;
@@ -5000,9 +5000,9 @@  static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 
 out:
-	cb->args[0] = h;
-	cb->args[1] = idx;
-	cb->args[2] = fidx;
+	ctx->s_h = h;
+	ctx->s_idx = idx;
+	ctx->fdb_idx = fidx;
 
 	return skb->len;
 }
diff --git a/net/dsa/user.c b/net/dsa/user.c
index 06c30a9e29ff820d2dd58fb1801d5e76a5928326..c736c019e2af90747738f10b667e6ad936c9eb0b 100644
--- a/net/dsa/user.c
+++ b/net/dsa/user.c
@@ -515,12 +515,13 @@  dsa_user_port_fdb_do_dump(const unsigned char *addr, u16 vid,
 			  bool is_static, void *data)
 {
 	struct dsa_user_dump_ctx *dump = data;
+	struct ndo_fdb_dump_context *ctx = (void *)dump->cb->ctx;
 	u32 portid = NETLINK_CB(dump->cb->skb).portid;
 	u32 seq = dump->cb->nlh->nlmsg_seq;
 	struct nlmsghdr *nlh;
 	struct ndmsg *ndm;
 
-	if (dump->idx < dump->cb->args[2])
+	if (dump->idx < ctx->fdb_idx)
 		goto skip;
 
 	nlh = nlmsg_put(dump->skb, portid, seq, RTM_NEWNEIGH,