[B.A.T.M.A.N.] [PATCH v10 04/16] batman-adv: netlink: hardif query

Sven Eckelmann
2016-07-03T11:31:36Z

From: Matthias Schiffer <mschiffer@universe-factory.net>

BATADV_CMD_GET_HARDIFS will return the list of hardifs (including index,
name and MAC address) of all hardifs for a given softif.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
[sven.eckelmann@open-mesh.com: Reduce the number of changes to
BATADV_CMD_GET_HARDIFS, add policy for attributes]
Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
include/uapi/linux/batman_adv.h | 4 ++
net/batman-adv/netlink.c | 128 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 130 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/batman_adv.h b/include/uapi/linux/batman_adv.h
index 297a04d..9ac9080 100644
--- a/include/uapi/linux/batman_adv.h
+++ b/include/uapi/linux/batman_adv.h
@@ -40,6 +40,7 @@
* @BATADV_ATTR_TPMETER_BYTES: amount of acked bytes during run
* @BATADV_ATTR_TPMETER_COOKIE: session cookie to match tp_meter session
* @BATADV_ATTR_PAD: attribute used for padding for 64-bit alignment
+ * @BATADV_ATTR_ACTIVE: Flag indicating if the hard interface is active
* @__BATADV_ATTR_AFTER_LAST: internal use
* @NUM_BATADV_ATTR: total number of batadv_nl_attrs available
* @BATADV_ATTR_MAX: highest attribute number currently defined
@@ -60,6 +61,7 @@ enum batadv_nl_attrs {
BATADV_ATTR_TPMETER_BYTES,
BATADV_ATTR_TPMETER_COOKIE,
BATADV_ATTR_PAD,
+ BATADV_ATTR_ACTIVE,
/* add attributes above here, update the policy in netlink.c */
__BATADV_ATTR_AFTER_LAST,
NUM_BATADV_ATTR = __BATADV_ATTR_AFTER_LAST,
@@ -74,6 +76,7 @@ enum batadv_nl_attrs {
* @BATADV_CMD_TP_METER: Start a tp meter session
* @BATADV_CMD_TP_METER_CANCEL: Cancel a tp meter session
* @BATADV_CMD_GET_ROUTING_ALGOS: Query the list of routing algorithms.
+ * @BATADV_CMD_GET_HARDIFS: Query list of hard interfaces
* @__BATADV_CMD_AFTER_LAST: internal use
* @BATADV_CMD_MAX: highest used command number
*/
@@ -83,6 +86,7 @@ enum batadv_nl_commands {
BATADV_CMD_TP_METER,
BATADV_CMD_TP_METER_CANCEL,
BATADV_CMD_GET_ROUTING_ALGOS,
+ BATADV_CMD_GET_HARDIFS,
/* add new commands above here */
__BATADV_CMD_AFTER_LAST,
BATADV_CMD_MAX = __BATADV_CMD_AFTER_LAST - 1
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c
index 19fb265..3f872d6 100644
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -26,10 +26,14 @@
#include <linux/netdevice.h>
#include <linux/netlink.h>
#include <linux/printk.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+#include <linux/skbuff.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <net/genetlink.h>
#include <net/netlink.h>
+#include <net/sock.h>
#include <uapi/linux/batman_adv.h>

#include "bat_algo.h"
@@ -37,8 +41,6 @@
#include "soft-interface.h"
#include "tp_meter.h"

-struct sk_buff;
-
struct genl_family batadv_netlink_family = {
.id = GENL_ID_GENERATE,
.hdrsize = 0,
@@ -70,9 +72,25 @@ static struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = {
[BATADV_ATTR_TPMETER_TEST_TIME] = { .type = NLA_U32 },
[BATADV_ATTR_TPMETER_BYTES] = { .type = NLA_U64 },
[BATADV_ATTR_TPMETER_COOKIE] = { .type = NLA_U32 },
+ [BATADV_ATTR_ACTIVE] = { .type = NLA_FLAG },
};

/**
+ * batadv_netlink_get_ifindex - Extract an interface index from a message
+ * @nlh: Message header
+ * @attrtype: Attribute which holds an interface index
+ *
+ * Return: interface index, or 0.
+ */
+static int
+batadv_netlink_get_ifindex(const struct nlmsghdr *nlh, int attrtype)
+{
+ struct nlattr *attr = nlmsg_find_attr(nlh, GENL_HDRLEN, attrtype);
+
+ return attr ? nla_get_u32(attr) : 0;
+}
+
+/**
* batadv_netlink_mesh_info_put - fill in generic information about mesh
* interface
* @msg: netlink message to be sent back
@@ -381,6 +399,106 @@ out:
return ret;
}

+/**
+ * batadv_netlink_dump_hardif_entry - Dump one hard interface into a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @hard_iface: Hard interface to dump
+ *
+ * Return: error code, or 0 on success
+ */
+static int
+batadv_netlink_dump_hardif_entry(struct sk_buff *msg, u32 portid, u32 seq,
+ struct batadv_hard_iface *hard_iface)
+{
+ struct net_device *net_dev = hard_iface->net_dev;
+ void *hdr;
+
+ hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, NLM_F_MULTI,
+ BATADV_CMD_GET_HARDIFS);
+ if (!hdr)
+ return -EMSGSIZE;
+
+ if (nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
+ net_dev->ifindex) ||
+ nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
+ net_dev->name) ||
+ nla_put(msg, BATADV_ATTR_HARD_ADDRESS, ETH_ALEN,
+ net_dev->dev_addr))
+ goto nla_put_failure;
+
+ if (hard_iface->if_status == BATADV_IF_ACTIVE) {
+ if (nla_put_flag(msg, BATADV_ATTR_ACTIVE))
+ goto nla_put_failure;
+ }
+
+ genlmsg_end(msg, hdr);
+ return 0;
+
+ nla_put_failure:
+ genlmsg_cancel(msg, hdr);
+ return -EMSGSIZE;
+}
+
+/**
+ * batadv_netlink_dump_hardifs - 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)
+{
+ struct net *net = sock_net(cb->skb->sk);
+ struct net_device *soft_iface;
+ struct batadv_hard_iface *hard_iface;
+ int ifindex;
+ int portid = NETLINK_CB(cb->skb).portid;
+ int seq = cb->nlh->nlmsg_seq;
+ int skip = cb->args[0];
+ int i = 0;
+
+ ifindex = batadv_netlink_get_ifindex(cb->nlh,
+ BATADV_ATTR_MESH_IFINDEX);
+ if (!ifindex)
+ return -EINVAL;
+
+ soft_iface = dev_get_by_index(net, ifindex);
+ if (!soft_iface)
+ return -ENODEV;
+
+ if (!batadv_softif_is_valid(soft_iface)) {
+ dev_put(soft_iface);
+ return -ENODEV;
+ }
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+ if (hard_iface->soft_iface != soft_iface)
+ continue;
+
+ if (i++ < skip)
+ continue;
+
+ if (batadv_netlink_dump_hardif_entry(msg, portid, seq,
+ hard_iface)) {
+ i--;
+ break;
+ }
+ }
+
+ rcu_read_unlock();
+
+ dev_put(soft_iface);
+
+ cb->args[0] = i;
+
+ return msg->len;
+}
+
static struct genl_ops batadv_netlink_ops[] = {
{
.cmd = BATADV_CMD_GET_MESH_INFO,
@@ -406,6 +524,12 @@ static struct genl_ops batadv_netlink_ops[] = {
.policy = batadv_netlink_policy,
.dumpit = batadv_algo_dump,
},
+ {
+ .cmd = BATADV_CMD_GET_HARDIFS,
+ .flags = GENL_ADMIN_PERM,
+ .policy = batadv_netlink_policy,
+ .dumpit = batadv_netlink_dump_hardifs,
+ },
};

/**
--
2.8.1