psp: report basic stats from the core

Track and report stats common to all psp devices from the core. A
'stale-event' is when the core marks the rx state of an active
psp_assoc as incapable of authenticating psp encapsulated data.

Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Link: https://patch.msgid.link/20251106002608.1578518-2-daniel.zahka@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 98 insertions, 1 deletions

diff --git a/net/psp/psp-nl-gen.c b/net/psp/psp-nl-gen.c
index 9fdd6f831803..73f8b06d66f0 100644
--- a/net/psp/psp-nl-gen.c
+++ b/net/psp/psp-nl-gen.c
@@ -47,6 +47,11 @@ static const struct nla_policy psp_tx_assoc_nl_policy[PSP_A_ASSOC_SOCK_FD + 1] =
 	[PSP_A_ASSOC_SOCK_FD] = { .type = NLA_U32, },
 };
 
+/* PSP_CMD_GET_STATS - do */
+static const struct nla_policy psp_get_stats_nl_policy[PSP_A_STATS_DEV_ID + 1] = {
+	[PSP_A_STATS_DEV_ID] = NLA_POLICY_MIN(NLA_U32, 1),
+};
+
 /* Ops table for psp */
 static const struct genl_split_ops psp_nl_ops[] = {
 	{
@@ -99,6 +104,20 @@ static const struct genl_split_ops psp_nl_ops[] = {
 		.maxattr	= PSP_A_ASSOC_SOCK_FD,
 		.flags		= GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= PSP_CMD_GET_STATS,
+		.pre_doit	= psp_device_get_locked,
+		.doit		= psp_nl_get_stats_doit,
+		.post_doit	= psp_device_unlock,
+		.policy		= psp_get_stats_nl_policy,
+		.maxattr	= PSP_A_STATS_DEV_ID,
+		.flags		= GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= PSP_CMD_GET_STATS,
+		.dumpit	= psp_nl_get_stats_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
 };
 
 static const struct genl_multicast_group psp_nl_mcgrps[] = {
diff --git a/net/psp/psp-nl-gen.h b/net/psp/psp-nl-gen.h
index 25268ed11fb5..5bc3b5d5a53e 100644
--- a/net/psp/psp-nl-gen.h
+++ b/net/psp/psp-nl-gen.h
@@ -28,6 +28,8 @@ int psp_nl_dev_set_doit(struct sk_buff *skb, struct genl_info *info);
 int psp_nl_key_rotate_doit(struct sk_buff *skb, struct genl_info *info);
 int psp_nl_rx_assoc_doit(struct sk_buff *skb, struct genl_info *info);
 int psp_nl_tx_assoc_doit(struct sk_buff *skb, struct genl_info *info);
+int psp_nl_get_stats_doit(struct sk_buff *skb, struct genl_info *info);
+int psp_nl_get_stats_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 
 enum {
 	PSP_NLGRP_MGMT,
diff --git a/net/psp/psp_nl.c b/net/psp/psp_nl.c
index 8aaca62744c3..f990cccbe99c 100644
--- a/net/psp/psp_nl.c
+++ b/net/psp/psp_nl.c
@@ -262,6 +262,7 @@ int psp_nl_key_rotate_doit(struct sk_buff *skb, struct genl_info *info)
 		     psd->generation & ~PSP_GEN_VALID_MASK);
 
 	psp_assocs_key_rotated(psd);
+	psd->stats.rotations++;
 
 	nlmsg_end(ntf, (struct nlmsghdr *)ntf->data);
 	genlmsg_multicast_netns(&psp_nl_family, dev_net(psd->main_netdev), ntf,
@@ -503,3 +504,76 @@ err_free_msg:
 	nlmsg_free(rsp);
 	return err;
 }
+
+static int
+psp_nl_stats_fill(struct psp_dev *psd, struct sk_buff *rsp,
+		  const struct genl_info *info)
+{
+	void *hdr;
+
+	hdr = genlmsg_iput(rsp, info);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	if (nla_put_u32(rsp, PSP_A_STATS_DEV_ID, psd->id) ||
+	    nla_put_uint(rsp, PSP_A_STATS_KEY_ROTATIONS,
+			 psd->stats.rotations) ||
+	    nla_put_uint(rsp, PSP_A_STATS_STALE_EVENTS, psd->stats.stales))
+		goto err_cancel_msg;
+
+	genlmsg_end(rsp, hdr);
+	return 0;
+
+err_cancel_msg:
+	genlmsg_cancel(rsp, hdr);
+	return -EMSGSIZE;
+}
+
+int psp_nl_get_stats_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct psp_dev *psd = info->user_ptr[0];
+	struct sk_buff *rsp;
+	int err;
+
+	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!rsp)
+		return -ENOMEM;
+
+	err = psp_nl_stats_fill(psd, rsp, info);
+	if (err)
+		goto err_free_msg;
+
+	return genlmsg_reply(rsp, info);
+
+err_free_msg:
+	nlmsg_free(rsp);
+	return err;
+}
+
+static int
+psp_nl_stats_get_dumpit_one(struct sk_buff *rsp, struct netlink_callback *cb,
+			    struct psp_dev *psd)
+{
+	if (psp_dev_check_access(psd, sock_net(rsp->sk)))
+		return 0;
+
+	return psp_nl_stats_fill(psd, rsp, genl_info_dump(cb));
+}
+
+int psp_nl_get_stats_dumpit(struct sk_buff *rsp, struct netlink_callback *cb)
+{
+	struct psp_dev *psd;
+	int err = 0;
+
+	mutex_lock(&psp_devs_lock);
+	xa_for_each_start(&psp_devs, cb->args[0], psd, cb->args[0]) {
+		mutex_lock(&psd->lock);
+		err = psp_nl_stats_get_dumpit_one(rsp, cb, psd);
+		mutex_unlock(&psd->lock);
+		if (err)
+			break;
+	}
+	mutex_unlock(&psp_devs_lock);
+
+	return err;
+}
diff --git a/net/psp/psp_sock.c b/net/psp/psp_sock.c
index a931d825d1cc..f785672b7df6 100644
--- a/net/psp/psp_sock.c
+++ b/net/psp/psp_sock.c
@@ -253,8 +253,10 @@ void psp_assocs_key_rotated(struct psp_dev *psd)
 	/* Mark the stale associations as invalid, they will no longer
 	 * be able to Rx any traffic.
 	 */
-	list_for_each_entry_safe(pas, next, &psd->prev_assocs, assocs_list)
+	list_for_each_entry_safe(pas, next, &psd->prev_assocs, assocs_list) {
 		pas->generation |= ~PSP_GEN_VALID_MASK;
+		psd->stats.stales++;
+	}
 	list_splice_init(&psd->prev_assocs, &psd->stale_assocs);
 	list_splice_init(&psd->active_assocs, &psd->prev_assocs);