From: Sven Eckelmann sven@narfation.org
The commit ff4c92d85c6f ("genetlink: introduce pre_doit/post_doit hooks") intoduced a mechanism to run specific code for doit hooks before/after the hooks are run. Since all doit hooks are requiring the batadv softif, it should be retrieved/freed in these helpers to simplify the code.
Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de --- net/batman-adv/netlink.c | 143 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 100 insertions(+), 43 deletions(-)
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c index 5fe833cc9507..e56c40d1bfe0 100644 --- a/net/batman-adv/netlink.c +++ b/net/batman-adv/netlink.c @@ -20,8 +20,10 @@ #include "main.h"
#include <linux/atomic.h> +#include <linux/bitops.h> #include <linux/byteorder/generic.h> #include <linux/cache.h> +#include <linux/err.h> #include <linux/errno.h> #include <linux/export.h> #include <linux/genetlink.h> @@ -54,6 +56,8 @@ #include "tp_meter.h" #include "translation-table.h"
+struct net; + struct genl_family batadv_netlink_family;
/* multicast groups */ @@ -61,6 +65,18 @@ enum batadv_netlink_multicast_groups { BATADV_NL_MCGRP_TPMETER, };
+/** + * enum batadv_genl_ops_flags - flags for genl_ops's internal_flags + */ +enum batadv_genl_ops_flags { + /** + * @BATADV_FLAG_NEED_MESH: request requires valid soft interface in + * attribute BATADV_ATTR_MESH_IFINDEX and expects a pointer to it to be + * saved in info->user_ptr[0] + */ + BATADV_FLAG_NEED_MESH = BIT(0), +}; + static const struct genl_multicast_group batadv_netlink_mcgrps[] = { [BATADV_NL_MCGRP_TPMETER] = { .name = BATADV_NL_MCAST_GROUP_TPMETER }, }; @@ -329,40 +345,24 @@ int batadv_netlink_tpmeter_notify(struct batadv_priv *bat_priv, const u8 *dst, static int batadv_netlink_tp_meter_start(struct sk_buff *skb, struct genl_info *info) { - struct net *net = genl_info_net(info); - struct net_device *soft_iface; - struct batadv_priv *bat_priv; + struct batadv_priv *bat_priv = info->user_ptr[0]; struct sk_buff *msg = NULL; u32 test_length; void *msg_head; - int ifindex; u32 cookie; u8 *dst; int ret;
- if (!info->attrs[BATADV_ATTR_MESH_IFINDEX]) - return -EINVAL; - if (!info->attrs[BATADV_ATTR_ORIG_ADDRESS]) return -EINVAL;
if (!info->attrs[BATADV_ATTR_TPMETER_TEST_TIME]) return -EINVAL;
- ifindex = nla_get_u32(info->attrs[BATADV_ATTR_MESH_IFINDEX]); - if (!ifindex) - return -EINVAL; - dst = nla_data(info->attrs[BATADV_ATTR_ORIG_ADDRESS]);
test_length = nla_get_u32(info->attrs[BATADV_ATTR_TPMETER_TEST_TIME]);
- soft_iface = dev_get_by_index(net, ifindex); - if (!soft_iface || !batadv_softif_is_valid(soft_iface)) { - ret = -ENODEV; - goto out; - } - msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) { ret = -ENOMEM; @@ -377,15 +377,11 @@ batadv_netlink_tp_meter_start(struct sk_buff *skb, struct genl_info *info) goto out; }
- bat_priv = netdev_priv(soft_iface); batadv_tp_start(bat_priv, dst, test_length, &cookie);
ret = batadv_netlink_tp_meter_put(msg, cookie);
out: - if (soft_iface) - dev_put(soft_iface); - if (ret) { if (msg) nlmsg_free(msg); @@ -406,38 +402,17 @@ batadv_netlink_tp_meter_start(struct sk_buff *skb, struct genl_info *info) static int batadv_netlink_tp_meter_cancel(struct sk_buff *skb, struct genl_info *info) { - struct net *net = genl_info_net(info); - struct net_device *soft_iface; - struct batadv_priv *bat_priv; - int ifindex; + struct batadv_priv *bat_priv = info->user_ptr[0]; u8 *dst; int ret = 0;
- if (!info->attrs[BATADV_ATTR_MESH_IFINDEX]) - return -EINVAL; - if (!info->attrs[BATADV_ATTR_ORIG_ADDRESS]) return -EINVAL;
- ifindex = nla_get_u32(info->attrs[BATADV_ATTR_MESH_IFINDEX]); - if (!ifindex) - return -EINVAL; - dst = nla_data(info->attrs[BATADV_ATTR_ORIG_ADDRESS]);
- soft_iface = dev_get_by_index(net, ifindex); - if (!soft_iface || !batadv_softif_is_valid(soft_iface)) { - ret = -ENODEV; - goto out; - } - - bat_priv = netdev_priv(soft_iface); batadv_tp_stop(bat_priv, dst, BATADV_TP_REASON_CANCEL);
-out: - if (soft_iface) - dev_put(soft_iface); - return ret; }
@@ -545,6 +520,84 @@ batadv_netlink_dump_hardifs(struct sk_buff *msg, struct netlink_callback *cb) return msg->len; }
+/** + * batadv_get_softif_from_info() - Retrieve soft interface from genl attributes + * @net: the applicable net namespace + * @info: receiver information + * + * Return: Pointer to soft interface (with increased refcnt) on success, error + * pointer on error + */ +static struct net_device * +batadv_get_softif_from_info(struct net *net, struct genl_info *info) +{ + struct net_device *soft_iface; + int ifindex; + + if (!info->attrs[BATADV_ATTR_MESH_IFINDEX]) + return ERR_PTR(-EINVAL); + + ifindex = nla_get_u32(info->attrs[BATADV_ATTR_MESH_IFINDEX]); + + soft_iface = dev_get_by_index(net, ifindex); + if (!soft_iface) + return ERR_PTR(-ENODEV); + + if (!batadv_softif_is_valid(soft_iface)) + goto err_put_softif; + + return soft_iface; + +err_put_softif: + dev_put(soft_iface); + + return ERR_PTR(-EINVAL); +} + +/** + * batadv_pre_doit() - Prepare batman-adv genl doit request + * @ops: requested netlink operation + * @skb: Netlink message with request data + * @info: receiver information + * + * Return: 0 on success or negative error number in case of failure + */ +static int batadv_pre_doit(const struct genl_ops *ops, struct sk_buff *skb, + struct genl_info *info) +{ + struct net *net = genl_info_net(info); + struct net_device *soft_iface; + struct batadv_priv *bat_priv; + + if (ops->internal_flags & BATADV_FLAG_NEED_MESH) { + soft_iface = batadv_get_softif_from_info(net, info); + if (IS_ERR(soft_iface)) + return PTR_ERR(soft_iface); + + bat_priv = netdev_priv(soft_iface); + info->user_ptr[0] = bat_priv; + } + + return 0; +} + +/** + * batadv_post_doit() - End batman-adv genl doit request + * @ops: requested netlink operation + * @skb: Netlink message with request data + * @info: receiver information + */ +static void batadv_post_doit(const struct genl_ops *ops, struct sk_buff *skb, + struct genl_info *info) +{ + struct batadv_priv *bat_priv; + + if (ops->internal_flags & BATADV_FLAG_NEED_MESH && info->user_ptr[0]) { + bat_priv = info->user_ptr[0]; + dev_put(bat_priv->soft_iface); + } +} + static const struct genl_ops batadv_netlink_ops[] = { { .cmd = BATADV_CMD_GET_MESH_INFO, @@ -557,12 +610,14 @@ static const struct genl_ops batadv_netlink_ops[] = { .flags = GENL_ADMIN_PERM, .policy = batadv_netlink_policy, .doit = batadv_netlink_tp_meter_start, + .internal_flags = BATADV_FLAG_NEED_MESH, }, { .cmd = BATADV_CMD_TP_METER_CANCEL, .flags = GENL_ADMIN_PERM, .policy = batadv_netlink_policy, .doit = batadv_netlink_tp_meter_cancel, + .internal_flags = BATADV_FLAG_NEED_MESH, }, { .cmd = BATADV_CMD_GET_ROUTING_ALGOS, @@ -639,6 +694,8 @@ struct genl_family batadv_netlink_family __ro_after_init = { .version = 1, .maxattr = BATADV_ATTR_MAX, .netnsok = true, + .pre_doit = batadv_pre_doit, + .post_doit = batadv_post_doit, .module = THIS_MODULE, .ops = batadv_netlink_ops, .n_ops = ARRAY_SIZE(batadv_netlink_ops),