From: Jakub Kicinski Rotating the device key is a key part of the PSP protocol design. Some external daemon needs to do it once a day, or so. Add a netlink op to perform this operation. Add a notification group for informing users that key has been rotated and they should rekey (next rotation will cut them off). Reviewed-by: Willem de Bruijn Signed-off-by: Jakub Kicinski Signed-off-by: Daniel Zahka --- Notes: v1: - https://lore.kernel.org/netdev/20240510030435.120935-6-kuba@kernel.org/ Documentation/netlink/specs/psp.yaml | 21 +++++++++++++++ include/net/psp/types.h | 5 ++++ include/uapi/linux/psp.h | 3 +++ net/psp/psp-nl-gen.c | 15 +++++++++++ net/psp/psp-nl-gen.h | 2 ++ net/psp/psp_main.c | 3 ++- net/psp/psp_nl.c | 40 ++++++++++++++++++++++++++++ 7 files changed, 88 insertions(+), 1 deletion(-) diff --git a/Documentation/netlink/specs/psp.yaml b/Documentation/netlink/specs/psp.yaml index 706f4baf8764..054cc02b65ad 100644 --- a/Documentation/netlink/specs/psp.yaml +++ b/Documentation/netlink/specs/psp.yaml @@ -88,9 +88,30 @@ operations: notify: dev-get mcgrp: mgmt + - + name: key-rotate + doc: Rotate the device key. + attribute-set: dev + do: + request: + attributes: + - id + reply: + attributes: + - id + pre: psp-device-get-locked + post: psp-device-unlock + - + name: key-rotate-ntf + doc: Notification about device key getting rotated. + notify: key-rotate + mcgrp: use + mcast-groups: list: - name: mgmt + - + name: use ... diff --git a/include/net/psp/types.h b/include/net/psp/types.h index 4922fc8d42fd..66327fa80c92 100644 --- a/include/net/psp/types.h +++ b/include/net/psp/types.h @@ -102,6 +102,11 @@ struct psp_dev_ops { */ int (*set_config)(struct psp_dev *psd, struct psp_dev_config *conf, struct netlink_ext_ack *extack); + + /** + * @key_rotate: rotate the device key + */ + int (*key_rotate)(struct psp_dev *psd, struct netlink_ext_ack *extack); }; #endif /* __NET_PSP_H */ diff --git a/include/uapi/linux/psp.h b/include/uapi/linux/psp.h index 4a404f085190..cbfbf3f0f364 100644 --- a/include/uapi/linux/psp.h +++ b/include/uapi/linux/psp.h @@ -32,11 +32,14 @@ enum { PSP_CMD_DEV_DEL_NTF, PSP_CMD_DEV_SET, PSP_CMD_DEV_CHANGE_NTF, + PSP_CMD_KEY_ROTATE, + PSP_CMD_KEY_ROTATE_NTF, __PSP_CMD_MAX, PSP_CMD_MAX = (__PSP_CMD_MAX - 1) }; #define PSP_MCGRP_MGMT "mgmt" +#define PSP_MCGRP_USE "use" #endif /* _UAPI_LINUX_PSP_H */ diff --git a/net/psp/psp-nl-gen.c b/net/psp/psp-nl-gen.c index 859712e7c2c1..7f49577ac72f 100644 --- a/net/psp/psp-nl-gen.c +++ b/net/psp/psp-nl-gen.c @@ -21,6 +21,11 @@ static const struct nla_policy psp_dev_set_nl_policy[PSP_A_DEV_PSP_VERSIONS_ENA [PSP_A_DEV_PSP_VERSIONS_ENA] = NLA_POLICY_MASK(NLA_U32, 0xf), }; +/* PSP_CMD_KEY_ROTATE - do */ +static const struct nla_policy psp_key_rotate_nl_policy[PSP_A_DEV_ID + 1] = { + [PSP_A_DEV_ID] = NLA_POLICY_MIN(NLA_U32, 1), +}; + /* Ops table for psp */ static const struct genl_split_ops psp_nl_ops[] = { { @@ -46,10 +51,20 @@ static const struct genl_split_ops psp_nl_ops[] = { .maxattr = PSP_A_DEV_PSP_VERSIONS_ENA, .flags = GENL_CMD_CAP_DO, }, + { + .cmd = PSP_CMD_KEY_ROTATE, + .pre_doit = psp_device_get_locked, + .doit = psp_nl_key_rotate_doit, + .post_doit = psp_device_unlock, + .policy = psp_key_rotate_nl_policy, + .maxattr = PSP_A_DEV_ID, + .flags = GENL_CMD_CAP_DO, + }, }; static const struct genl_multicast_group psp_nl_mcgrps[] = { [PSP_NLGRP_MGMT] = { "mgmt", }, + [PSP_NLGRP_USE] = { "use", }, }; struct genl_family psp_nl_family __ro_after_init = { diff --git a/net/psp/psp-nl-gen.h b/net/psp/psp-nl-gen.h index a099686cab5d..00a2d4ec59e4 100644 --- a/net/psp/psp-nl-gen.h +++ b/net/psp/psp-nl-gen.h @@ -20,9 +20,11 @@ psp_device_unlock(const struct genl_split_ops *ops, struct sk_buff *skb, int psp_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info); int psp_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb); 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); enum { PSP_NLGRP_MGMT, + PSP_NLGRP_USE, }; extern struct genl_family psp_nl_family; diff --git a/net/psp/psp_main.c b/net/psp/psp_main.c index 35f69fe3d1a2..7f1a6cda6a7a 100644 --- a/net/psp/psp_main.c +++ b/net/psp/psp_main.c @@ -54,7 +54,8 @@ psp_dev_create(struct net_device *netdev, int err; if (WARN_ON(!psd_caps->versions || - !psd_ops->set_config)) + !psd_ops->set_config || + !psd_ops->key_rotate)) return ERR_PTR(-EINVAL); psd = kzalloc(sizeof(*psd), GFP_KERNEL); diff --git a/net/psp/psp_nl.c b/net/psp/psp_nl.c index fda5ce800f82..b7006e50dc87 100644 --- a/net/psp/psp_nl.c +++ b/net/psp/psp_nl.c @@ -221,3 +221,43 @@ int psp_nl_dev_set_doit(struct sk_buff *skb, struct genl_info *info) nlmsg_free(rsp); return err; } + +int psp_nl_key_rotate_doit(struct sk_buff *skb, struct genl_info *info) +{ + struct psp_dev *psd = info->user_ptr[0]; + struct genl_info ntf_info; + struct sk_buff *ntf, *rsp; + int err; + + rsp = psp_nl_reply_new(info); + if (!rsp) + return -ENOMEM; + + genl_info_init_ntf(&ntf_info, &psp_nl_family, PSP_CMD_KEY_ROTATE); + ntf = psp_nl_reply_new(&ntf_info); + if (!ntf) { + err = -ENOMEM; + goto err_free_rsp; + } + + if (nla_put_u32(rsp, PSP_A_DEV_ID, psd->id) || + nla_put_u32(ntf, PSP_A_DEV_ID, psd->id)) { + err = -EMSGSIZE; + goto err_free_ntf; + } + + err = psd->ops->key_rotate(psd, info->extack); + if (err) + goto err_free_ntf; + + nlmsg_end(ntf, (struct nlmsghdr *)ntf->data); + genlmsg_multicast_netns(&psp_nl_family, dev_net(psd->main_netdev), ntf, + 0, PSP_NLGRP_USE, GFP_KERNEL); + return psp_nl_reply_send(rsp, info); + +err_free_ntf: + nlmsg_free(ntf); +err_free_rsp: + nlmsg_free(rsp); + return err; +} -- 2.47.1