net: mptcp: convert netlink from small_ops to ops

in the current MPTCP control plane, all operations use a netlink
attribute of the same type "MPTCP_PM_ATTR". However, add/del/get/flush
operations only parse the first element in the message _ the one that
describes MPTCP endpoints (that was named MPTCP_PM_ATTR_ADDR and
mostly used in ADD_ADDR operations _ probably the similarity of "attr",
"addr" and "add" might cause some confusion to human readers).
Convert MPTCP from 'small_ops' to 'ops', thus allowing different attributes
for each single operation, hopefully makes all this clearer to human
readers.

- use a separate attribute set for add/del/get/flush address operation,
  binary compatible with the existing one, to store the endpoint address.
  MPTCP_PM_ENDPOINT_ADDR is added to the uAPI (with the same value as
  MPTCP_PM_ATTR_ADDR) for these operations.
- convert mptcp_pm_ops[] and add policy files accordingly.

this prepares MPTCP control plane to be described as YAML spec.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/340
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-1-v2-3-16b1f701f900@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index ee9c49f949a2c54e96c5b949ed21902e507e1ac5..0e62937ab17cfc7aa4c55af6e33348a44ac31d18 100644 (file)
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -65,6 +65,14 @@ enum {
 
 #define MPTCP_PM_ATTR_MAX (__MPTCP_PM_ATTR_MAX - 1)
 
+enum {
+       MPTCP_PM_ENDPOINT_ADDR = 1,
+
+       __MPTCP_PM_ENDPOINT_MAX
+};
+
+#define MPTCP_PM_ENDPOINT_MAX (__MPTCP_PM_ENDPOINT_MAX - 1)
+
 enum {
        MPTCP_PM_ADDR_ATTR_UNSPEC,
 

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 9661f38126826d2f9fcede4d4167af39c31cdc33..fd4e843505e516bec98f6b577ee743d30ef31e57 100644 (file)
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -48,6 +48,60 @@ struct pm_nl_pernet {
 #define MPTCP_PM_ADDR_MAX      8
 #define ADD_ADDR_RETRANS_MAX   3
 
+static
+const struct nla_policy mptcp_pm_address_nl_policy[MPTCP_PM_ADDR_ATTR_IF_IDX + 1] = {
+       [MPTCP_PM_ADDR_ATTR_FAMILY] = { .type = NLA_U16, },
+       [MPTCP_PM_ADDR_ATTR_ID] = { .type = NLA_U8, },
+       [MPTCP_PM_ADDR_ATTR_ADDR4] = { .type = NLA_U32, },
+       [MPTCP_PM_ADDR_ATTR_ADDR6] = NLA_POLICY_EXACT_LEN(16),
+       [MPTCP_PM_ADDR_ATTR_PORT] = { .type = NLA_U16, },
+       [MPTCP_PM_ADDR_ATTR_FLAGS] = { .type = NLA_U32, },
+       [MPTCP_PM_ADDR_ATTR_IF_IDX] = { .type = NLA_S32, },
+};
+
+/* MPTCP_PM_CMD_ADD_ADDR / DEL / GET / FLUSH - do */
+static
+const struct nla_policy mptcp_pm_endpoint_nl_policy[MPTCP_PM_ENDPOINT_ADDR + 1] = {
+       [MPTCP_PM_ENDPOINT_ADDR] = NLA_POLICY_NESTED(mptcp_pm_address_nl_policy),
+};
+
+/* MPTCP_PM_CMD_SET_LIMITS - do */
+static
+const struct nla_policy mptcp_pm_set_limits_nl_policy[MPTCP_PM_ATTR_SUBFLOWS + 1] = {
+       [MPTCP_PM_ATTR_RCV_ADD_ADDRS] = { .type = NLA_U32, },
+       [MPTCP_PM_ATTR_SUBFLOWS] = { .type = NLA_U32, },
+};
+
+/* MPTCP_PM_CMD_SET_FLAGS - do */
+static
+const struct nla_policy mptcp_pm_set_flags_nl_policy[MPTCP_PM_ATTR_ADDR_REMOTE + 1] = {
+       [MPTCP_PM_ATTR_ADDR] = NLA_POLICY_NESTED(mptcp_pm_address_nl_policy),
+       [MPTCP_PM_ATTR_TOKEN] = { .type = NLA_U32, },
+       [MPTCP_PM_ATTR_ADDR_REMOTE] = NLA_POLICY_NESTED(mptcp_pm_address_nl_policy),
+};
+
+/* MPTCP_PM_CMD_ANNOUNCE - do */
+static
+const struct nla_policy mptcp_pm_announce_nl_policy[MPTCP_PM_ATTR_TOKEN + 1] = {
+       [MPTCP_PM_ATTR_ADDR] = NLA_POLICY_NESTED(mptcp_pm_address_nl_policy),
+       [MPTCP_PM_ATTR_TOKEN] = { .type = NLA_U32, },
+};
+
+/* MPTCP_PM_CMD_REMOVE - do */
+static
+const struct nla_policy mptcp_pm_remove_nl_policy[MPTCP_PM_ATTR_LOC_ID + 1] = {
+       [MPTCP_PM_ATTR_TOKEN] = { .type = NLA_U32, },
+       [MPTCP_PM_ATTR_LOC_ID] = { .type = NLA_U8, },
+};
+
+/* MPTCP_PM_CMD_SUBFLOW_CREATE / DESTROY - do */
+static
+const struct nla_policy mptcp_pm_subflow_create_nl_policy[MPTCP_PM_ATTR_ADDR_REMOTE + 1] = {
+       [MPTCP_PM_ATTR_ADDR] = NLA_POLICY_NESTED(mptcp_pm_address_nl_policy),
+       [MPTCP_PM_ATTR_TOKEN] = { .type = NLA_U32, },
+       [MPTCP_PM_ATTR_ADDR_REMOTE] = NLA_POLICY_NESTED(mptcp_pm_address_nl_policy),
+};
+
 static struct pm_nl_pernet *pm_nl_get_pernet(const struct net *net)
 {
        return net_generic(net, pm_nl_pernet_id);
@@ -1104,29 +1158,6 @@ static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
                                          },
 };
 
-static const struct nla_policy
-mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
-       [MPTCP_PM_ADDR_ATTR_FAMILY]     = { .type       = NLA_U16,      },
-       [MPTCP_PM_ADDR_ATTR_ID]         = { .type       = NLA_U8,       },
-       [MPTCP_PM_ADDR_ATTR_ADDR4]      = { .type       = NLA_U32,      },
-       [MPTCP_PM_ADDR_ATTR_ADDR6]      =
-               NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
-       [MPTCP_PM_ADDR_ATTR_PORT]       = { .type       = NLA_U16       },
-       [MPTCP_PM_ADDR_ATTR_FLAGS]      = { .type       = NLA_U32       },
-       [MPTCP_PM_ADDR_ATTR_IF_IDX]     = { .type       = NLA_S32       },
-};
-
-static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
-       [MPTCP_PM_ATTR_ADDR]            =
-                                       NLA_POLICY_NESTED(mptcp_pm_addr_policy),
-       [MPTCP_PM_ATTR_RCV_ADD_ADDRS]   = { .type       = NLA_U32,      },
-       [MPTCP_PM_ATTR_SUBFLOWS]        = { .type       = NLA_U32,      },
-       [MPTCP_PM_ATTR_TOKEN]           = { .type       = NLA_U32,      },
-       [MPTCP_PM_ATTR_LOC_ID]          = { .type       = NLA_U8,       },
-       [MPTCP_PM_ATTR_ADDR_REMOTE]     =
-                                       NLA_POLICY_NESTED(mptcp_pm_addr_policy),
-};
-
 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
 {
        struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk);
@@ -1188,7 +1219,7 @@ static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
 
        /* no validation needed - was already done via nested policy */
        err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
-                                         mptcp_pm_addr_policy, info->extack);
+                                         mptcp_pm_address_nl_policy, info->extack);
        if (err)
                return err;
 
@@ -1305,7 +1336,7 @@ next:
 
 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
 {
-       struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+       struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
        struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
        struct mptcp_pm_addr_entry addr, *entry;
        int ret;
@@ -1486,7 +1517,7 @@ next:
 
 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
 {
-       struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+       struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
        struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
        struct mptcp_pm_addr_entry addr, *entry;
        unsigned int addr_max;
@@ -1677,7 +1708,7 @@ nla_put_failure:
 
 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
 {
-       struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
+       struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
        struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
        struct mptcp_pm_addr_entry addr, *entry;
        struct sk_buff *msg;
@@ -2283,72 +2314,104 @@ nla_put_failure:
        nlmsg_free(skb);
 }
 
-static const struct genl_small_ops mptcp_pm_ops[] = {
+static const struct genl_ops mptcp_pm_ops[] = {
        {
-               .cmd    = MPTCP_PM_CMD_ADD_ADDR,
-               .doit   = mptcp_nl_cmd_add_addr,
-               .flags  = GENL_UNS_ADMIN_PERM,
+               .cmd            = MPTCP_PM_CMD_ADD_ADDR,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_add_addr,
+               .policy         = mptcp_pm_endpoint_nl_policy,
+               .maxattr        = MPTCP_PM_ENDPOINT_ADDR,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
        {
-               .cmd    = MPTCP_PM_CMD_DEL_ADDR,
-               .doit   = mptcp_nl_cmd_del_addr,
-               .flags  = GENL_UNS_ADMIN_PERM,
+               .cmd            = MPTCP_PM_CMD_DEL_ADDR,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_del_addr,
+               .policy         = mptcp_pm_endpoint_nl_policy,
+               .maxattr        = MPTCP_PM_ENDPOINT_ADDR,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
        {
-               .cmd    = MPTCP_PM_CMD_FLUSH_ADDRS,
-               .doit   = mptcp_nl_cmd_flush_addrs,
-               .flags  = GENL_UNS_ADMIN_PERM,
+               .cmd            = MPTCP_PM_CMD_GET_ADDR,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_get_addr,
+               .dumpit         = mptcp_nl_cmd_dump_addrs,
+               .policy         = mptcp_pm_endpoint_nl_policy,
+               .maxattr        = MPTCP_PM_ENDPOINT_ADDR,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
        {
-               .cmd    = MPTCP_PM_CMD_GET_ADDR,
-               .doit   = mptcp_nl_cmd_get_addr,
-               .dumpit   = mptcp_nl_cmd_dump_addrs,
+               .cmd            = MPTCP_PM_CMD_FLUSH_ADDRS,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_flush_addrs,
+               .policy         = mptcp_pm_endpoint_nl_policy,
+               .maxattr        = MPTCP_PM_ENDPOINT_ADDR,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
        {
-               .cmd    = MPTCP_PM_CMD_SET_LIMITS,
-               .doit   = mptcp_nl_cmd_set_limits,
-               .flags  = GENL_UNS_ADMIN_PERM,
+               .cmd            = MPTCP_PM_CMD_SET_LIMITS,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_set_limits,
+               .policy         = mptcp_pm_set_limits_nl_policy,
+               .maxattr        = MPTCP_PM_ATTR_SUBFLOWS,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
        {
-               .cmd    = MPTCP_PM_CMD_GET_LIMITS,
-               .doit   = mptcp_nl_cmd_get_limits,
+               .cmd            = MPTCP_PM_CMD_GET_LIMITS,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_get_limits,
+               .policy         = mptcp_pm_set_limits_nl_policy,
+               .maxattr        = MPTCP_PM_ATTR_SUBFLOWS,
        },
        {
-               .cmd    = MPTCP_PM_CMD_SET_FLAGS,
-               .doit   = mptcp_nl_cmd_set_flags,
-               .flags  = GENL_UNS_ADMIN_PERM,
+               .cmd            = MPTCP_PM_CMD_SET_FLAGS,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_set_flags,
+               .policy         = mptcp_pm_set_flags_nl_policy,
+               .maxattr        = MPTCP_PM_ATTR_ADDR_REMOTE,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
        {
-               .cmd    = MPTCP_PM_CMD_ANNOUNCE,
-               .doit   = mptcp_nl_cmd_announce,
-               .flags  = GENL_UNS_ADMIN_PERM,
+               .cmd            = MPTCP_PM_CMD_ANNOUNCE,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_announce,
+               .policy         = mptcp_pm_announce_nl_policy,
+               .maxattr        = MPTCP_PM_ATTR_TOKEN,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
        {
-               .cmd    = MPTCP_PM_CMD_REMOVE,
-               .doit   = mptcp_nl_cmd_remove,
-               .flags  = GENL_UNS_ADMIN_PERM,
+               .cmd            = MPTCP_PM_CMD_REMOVE,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_remove,
+               .policy         = mptcp_pm_remove_nl_policy,
+               .maxattr        = MPTCP_PM_ATTR_LOC_ID,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
        {
-               .cmd    = MPTCP_PM_CMD_SUBFLOW_CREATE,
-               .doit   = mptcp_nl_cmd_sf_create,
-               .flags  = GENL_UNS_ADMIN_PERM,
+               .cmd            = MPTCP_PM_CMD_SUBFLOW_CREATE,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_sf_create,
+               .policy         = mptcp_pm_subflow_create_nl_policy,
+               .maxattr        = MPTCP_PM_ATTR_ADDR_REMOTE,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
        {
-               .cmd    = MPTCP_PM_CMD_SUBFLOW_DESTROY,
-               .doit   = mptcp_nl_cmd_sf_destroy,
-               .flags  = GENL_UNS_ADMIN_PERM,
+               .cmd            = MPTCP_PM_CMD_SUBFLOW_DESTROY,
+               .validate       = GENL_DONT_VALIDATE_STRICT,
+               .doit           = mptcp_nl_cmd_sf_destroy,
+               .policy         = mptcp_pm_subflow_create_nl_policy,
+               .maxattr        = MPTCP_PM_ATTR_ADDR_REMOTE,
+               .flags          = GENL_UNS_ADMIN_PERM,
        },
 };
 
 static struct genl_family mptcp_genl_family __ro_after_init = {
        .name           = MPTCP_PM_NAME,
        .version        = MPTCP_PM_VER,
-       .maxattr        = MPTCP_PM_ATTR_MAX,
-       .policy         = mptcp_pm_policy,
        .netnsok        = true,
        .module         = THIS_MODULE,
-       .small_ops      = mptcp_pm_ops,
-       .n_small_ops    = ARRAY_SIZE(mptcp_pm_ops),
+       .ops            = mptcp_pm_ops,
+       .n_ops          = ARRAY_SIZE(mptcp_pm_ops),
        .resv_start_op  = MPTCP_PM_CMD_SUBFLOW_DESTROY + 1,
        .mcgrps         = mptcp_pm_mcgrps,
        .n_mcgrps       = ARRAY_SIZE(mptcp_pm_mcgrps),