The batman-adv configuration interface was implemented solely using sysfs. This approach was condemned by non-batadv developers as "huge mistake". Instead a netlink/genl based implementation was suggested.
Beside the mesh/soft-interface specific configuration, the slave/hard-interface have B.A.T.M.A.N. V specific configuration settings. The genl interface reflects this by allowing to get/set it using the hard-interface specific commands.
The BATADV_CMD_GET_HARDIFS (or short version BATADV_CMD_GET_HARDIF) is reused as get command because it already allow sto dump the content of other information from the slave/hard-interface which are not yet configuration specific.
The set command BATADV_CMD_SET_HARDIF will also notify interested userspace listeners of the "config" mcast group using the BATADV_CMD_SET_HARDIF command message type that settings might have been changed and what the current values are.
Signed-off-by: Sven Eckelmann sven@narfation.org --- include/uapi/linux/batman_adv.h | 16 ++- net/batman-adv/netlink.c | 240 +++++++++++++++++++++++++++++--- 2 files changed, 233 insertions(+), 23 deletions(-)
diff --git a/include/uapi/linux/batman_adv.h b/include/uapi/linux/batman_adv.h index b3394aac..62456a08 100644 --- a/include/uapi/linux/batman_adv.h +++ b/include/uapi/linux/batman_adv.h @@ -398,9 +398,15 @@ enum batadv_nl_commands { BATADV_CMD_GET_ROUTING_ALGOS,
/** - * @BATADV_CMD_GET_HARDIFS: Query list of hard interfaces + * @BATADV_CMD_GET_HARDIF: Get attributes from a hardif of the + * current softif */ - BATADV_CMD_GET_HARDIFS, + BATADV_CMD_GET_HARDIF, + + /** + * @BATADV_CMD_GET_HARDIFS: Alias for @BATADV_CMD_GET_HARDIF + */ + BATADV_CMD_GET_HARDIFS = BATADV_CMD_GET_HARDIF,
/** * @BATADV_CMD_GET_TRANSTABLE_LOCAL: Query list of local translations @@ -453,6 +459,12 @@ enum batadv_nl_commands { */ BATADV_CMD_SET_MESH,
+ /** + * @BATADV_CMD_SET_HARDIF: Set attributes for hardif of the + * current softif + */ + BATADV_CMD_SET_HARDIF, + /* add new commands above here */
/** diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c index 179cc7cf..a184e422 100644 --- a/net/batman-adv/netlink.c +++ b/net/batman-adv/netlink.c @@ -21,6 +21,7 @@
#include <linux/atomic.h> #include <linux/bitops.h> +#include <linux/bug.h> #include <linux/byteorder/generic.h> #include <linux/cache.h> #include <linux/err.h> @@ -76,6 +77,13 @@ enum batadv_genl_ops_flags { * saved in info->user_ptr[0] */ BATADV_FLAG_NEED_MESH = BIT(0), + + /** + * @BATADV_FLAG_NEED_HARDIF: request requires valid hard interface in + * attribute BATADV_ATTR_HARD_IFINDEX and expects a pointer to it to be + * saved in info->user_ptr[1] + */ + BATADV_FLAG_NEED_HARDIF = BIT(1), };
static const struct genl_multicast_group batadv_netlink_mcgrps[] = { @@ -446,29 +454,38 @@ batadv_netlink_tp_meter_cancel(struct sk_buff *skb, struct genl_info *info) }
/** - * batadv_netlink_dump_hardif_entry() - Dump one hard interface into a message + * batadv_netlink_hardif_fill() - Fill message with hardif attributes * @msg: Netlink message to dump into + * @bat_priv: the bat priv with all the soft interface information + * @hard_iface: hard interface which was modified + * @cmd: type of message to generate * @portid: Port making netlink request + * @seq: sequence number for message + * @flags: Additional flags for message * @cb: Control block containing additional options - * @hard_iface: Hard interface to dump * - * Return: error code, or 0 on success + * Return: 0 on success or negative error number in case of failure */ -static int -batadv_netlink_dump_hardif_entry(struct sk_buff *msg, u32 portid, - struct netlink_callback *cb, - struct batadv_hard_iface *hard_iface) +static int batadv_netlink_hardif_fill(struct sk_buff *msg, + struct batadv_priv *bat_priv, + struct batadv_hard_iface *hard_iface, + enum batadv_nl_commands cmd, + u32 portid, u32 seq, int flags, + struct netlink_callback *cb) { struct net_device *net_dev = hard_iface->net_dev; void *hdr;
- hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq, - &batadv_netlink_family, NLM_F_MULTI, - BATADV_CMD_GET_HARDIFS); + hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, flags, cmd); if (!hdr) - return -EMSGSIZE; + return -ENOBUFS; + + if (cb) + genl_dump_check_consistent(cb, hdr);
- genl_dump_check_consistent(cb, hdr); + if (nla_put_u32(msg, BATADV_ATTR_MESH_IFINDEX, + bat_priv->soft_iface->ifindex)) + goto nla_put_failure;
if (nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX, net_dev->ifindex) || @@ -486,24 +503,107 @@ batadv_netlink_dump_hardif_entry(struct sk_buff *msg, u32 portid, genlmsg_end(msg, hdr); return 0;
- nla_put_failure: +nla_put_failure: genlmsg_cancel(msg, hdr); return -EMSGSIZE; }
/** - * batadv_netlink_dump_hardifs() - Dump all hard interface into a messages + * batadv_netlink_notify_hardif() - send hardif attributes to listener + * @bat_priv: the bat priv with all the soft interface information + * @hard_iface: hard interface which was modified + * + * Return: 0 on success, < 0 on error + */ +static int batadv_netlink_notify_hardif(struct batadv_priv *bat_priv, + struct batadv_hard_iface *hard_iface) +{ + struct sk_buff *msg; + int ret; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + ret = batadv_netlink_hardif_fill(msg, bat_priv, hard_iface, + BATADV_CMD_SET_HARDIF, 0, 0, 0, NULL); + if (ret < 0) { + nlmsg_free(msg); + return ret; + } + + genlmsg_multicast_netns(&batadv_netlink_family, + dev_net(bat_priv->soft_iface), msg, 0, + BATADV_NL_MCGRP_CONFIG, GFP_KERNEL); + + return 0; +} + +/** + * batadv_netlink_get_hardif() - Get hardif attributes + * @skb: Netlink message with request data + * @info: receiver information + * + * Return: 0 on success or negative error number in case of failure + */ +static int batadv_netlink_get_hardif(struct sk_buff *skb, + struct genl_info *info) +{ + struct batadv_hard_iface *hard_iface = info->user_ptr[1]; + struct batadv_priv *bat_priv = info->user_ptr[0]; + struct sk_buff *msg; + int ret; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + ret = batadv_netlink_hardif_fill(msg, bat_priv, hard_iface, + BATADV_CMD_GET_HARDIF, + info->snd_portid, info->snd_seq, 0, + NULL); + if (ret < 0) { + nlmsg_free(msg); + return ret; + } + + ret = genlmsg_reply(msg, info); + + return ret; +} + +/** + * batadv_netlink_set_hardif() - Set hardif attributes + * @skb: Netlink message with request data + * @info: receiver information + * + * Return: 0 on success or negative error number in case of failure + */ +static int batadv_netlink_set_hardif(struct sk_buff *skb, + struct genl_info *info) +{ + struct batadv_hard_iface *hard_iface = info->user_ptr[1]; + struct batadv_priv *bat_priv = info->user_ptr[0]; + + batadv_netlink_notify_hardif(bat_priv, hard_iface); + + return 0; +} + +/** + * batadv_netlink_dump_hardif() - Dump all hard interface into a messages * @msg: Netlink message to dump into * @cb: Parameters from query * * Return: error code, or length of reply message on success */ static int -batadv_netlink_dump_hardifs(struct sk_buff *msg, struct netlink_callback *cb) +batadv_netlink_dump_hardif(struct sk_buff *msg, struct netlink_callback *cb) { struct net *net = sock_net(cb->skb->sk); struct net_device *soft_iface; struct batadv_hard_iface *hard_iface; + struct batadv_priv *bat_priv; int ifindex; int portid = NETLINK_CB(cb->skb).portid; int skip = cb->args[0]; @@ -523,6 +623,8 @@ batadv_netlink_dump_hardifs(struct sk_buff *msg, struct netlink_callback *cb) return -ENODEV; }
+ bat_priv = netdev_priv(soft_iface); + rtnl_lock(); cb->seq = batadv_hardif_generation << 1 | 1;
@@ -533,8 +635,10 @@ batadv_netlink_dump_hardifs(struct sk_buff *msg, struct netlink_callback *cb) if (i++ < skip) continue;
- if (batadv_netlink_dump_hardif_entry(msg, portid, cb, - hard_iface)) { + if (batadv_netlink_hardif_fill(msg, bat_priv, hard_iface, + BATADV_CMD_GET_HARDIF, + portid, cb->nlh->nlmsg_seq, + NLM_F_MULTI, cb)) { i--; break; } @@ -583,6 +687,52 @@ batadv_get_softif_from_info(struct net *net, struct genl_info *info) return ERR_PTR(-EINVAL); }
+/** + * batadv_get_hardif_from_info() - Retrieve hardif from genl attributes + * @bat_priv: the bat priv with all the soft interface information + * @net: the applicable net namespace + * @info: receiver information + * + * Return: Pointer to hard interface (with increased refcnt) on success, error + * pointer on error + */ +static struct batadv_hard_iface * +batadv_get_hardif_from_info(struct batadv_priv *bat_priv, struct net *net, + struct genl_info *info) +{ + struct batadv_hard_iface *hard_iface; + struct net_device *hard_dev; + unsigned int hardif_index; + + if (!info->attrs[BATADV_ATTR_HARD_IFINDEX]) + return ERR_PTR(-EINVAL); + + hardif_index = nla_get_u32(info->attrs[BATADV_ATTR_HARD_IFINDEX]); + + hard_dev = dev_get_by_index(net, hardif_index); + if (!hard_dev) + return ERR_PTR(-ENODEV); + + hard_iface = batadv_hardif_get_by_netdev(hard_dev); + if (!hard_iface) + goto err_put_harddev; + + if (hard_iface->soft_iface != bat_priv->soft_iface) + goto err_put_hardif; + + /* hard_dev is referenced by hard_iface and not needed here */ + dev_put(hard_dev); + + return hard_iface; + +err_put_hardif: + batadv_hardif_put(hard_iface); +err_put_harddev: + dev_put(hard_dev); + + return ERR_PTR(-EINVAL); +} + /** * batadv_pre_doit() - Prepare batman-adv genl doit request * @ops: requested netlink operation @@ -595,8 +745,21 @@ 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 batadv_hard_iface *hard_iface; + struct batadv_priv *bat_priv = NULL; struct net_device *soft_iface; - struct batadv_priv *bat_priv; + u8 user_ptr1_flags; + u8 mesh_dep_flags; + int ret; + + user_ptr1_flags = BATADV_FLAG_NEED_HARDIF; + if (WARN_ON(hweight8(ops->internal_flags & user_ptr1_flags) > 1)) + return -EINVAL; + + mesh_dep_flags = BATADV_FLAG_NEED_HARDIF; + if (WARN_ON((ops->internal_flags & mesh_dep_flags) && + (~ops->internal_flags & BATADV_FLAG_NEED_MESH))) + return -EINVAL;
if (ops->internal_flags & BATADV_FLAG_NEED_MESH) { soft_iface = batadv_get_softif_from_info(net, info); @@ -607,7 +770,23 @@ static int batadv_pre_doit(const struct genl_ops *ops, struct sk_buff *skb, info->user_ptr[0] = bat_priv; }
+ if (ops->internal_flags & BATADV_FLAG_NEED_HARDIF) { + hard_iface = batadv_get_hardif_from_info(bat_priv, net, info); + if (IS_ERR(hard_iface)) { + ret = PTR_ERR(hard_iface); + goto err_put_softif; + } + + info->user_ptr[1] = hard_iface; + } + return 0; + +err_put_softif: + if (bat_priv) + dev_put(bat_priv->soft_iface); + + return ret; }
/** @@ -619,8 +798,16 @@ static int batadv_pre_doit(const struct genl_ops *ops, struct sk_buff *skb, static void batadv_post_doit(const struct genl_ops *ops, struct sk_buff *skb, struct genl_info *info) { + struct batadv_hard_iface *hard_iface; struct batadv_priv *bat_priv;
+ if (ops->internal_flags & BATADV_FLAG_NEED_HARDIF && + info->user_ptr[1]) { + hard_iface = info->user_ptr[1]; + + batadv_hardif_put(hard_iface); + } + if (ops->internal_flags & BATADV_FLAG_NEED_MESH && info->user_ptr[0]) { bat_priv = info->user_ptr[0]; dev_put(bat_priv->soft_iface); @@ -656,10 +843,13 @@ static const struct genl_ops batadv_netlink_ops[] = { .dumpit = batadv_algo_dump, }, { - .cmd = BATADV_CMD_GET_HARDIFS, - .flags = GENL_ADMIN_PERM, + .cmd = BATADV_CMD_GET_HARDIF, + /* can be retrieved by unprivileged users */ .policy = batadv_netlink_policy, - .dumpit = batadv_netlink_dump_hardifs, + .dumpit = batadv_netlink_dump_hardif, + .doit = batadv_netlink_get_hardif, + .internal_flags = BATADV_FLAG_NEED_MESH | + BATADV_FLAG_NEED_HARDIF, }, { .cmd = BATADV_CMD_GET_TRANSTABLE_LOCAL, @@ -722,6 +912,14 @@ static const struct genl_ops batadv_netlink_ops[] = { .doit = batadv_netlink_set_mesh, .internal_flags = BATADV_FLAG_NEED_MESH, }, + { + .cmd = BATADV_CMD_SET_HARDIF, + .flags = GENL_ADMIN_PERM, + .policy = batadv_netlink_policy, + .doit = batadv_netlink_set_hardif, + .internal_flags = BATADV_FLAG_NEED_MESH | + BATADV_FLAG_NEED_HARDIF, + }, };
struct genl_family batadv_netlink_family __ro_after_init = {