[B.A.T.M.A.N.] [PATCH v6 03/11] batman-adv: netlink: add routing_algo query

Andrew Lunn
2016-05-16T17:28:01Z

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

BATADV_CMD_GET_ROUTING_ALGOS is used to get the list of supported routing
algorithms.

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_ROUTING_ALGOS]
Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
---
compat-include/linux/netlink.h | 45 ++++++++++++++++++++++++++++
include/uapi/linux/batman_adv.h | 2 ++
net/batman-adv/main.c | 66 +++++++++++++++++++++++++++++++++++++++++
net/batman-adv/main.h | 2 ++
net/batman-adv/netlink.c | 10 +++++--
net/batman-adv/netlink.h | 9 ++++++
6 files changed, 132 insertions(+), 2 deletions(-)
create mode 100644 compat-include/linux/netlink.h

diff --git a/compat-include/linux/netlink.h b/compat-include/linux/netlink.h
new file mode 100644
index 0000000..4d0eb5b
--- /dev/null
+++ b/compat-include/linux/netlink.h
@@ -0,0 +1,45 @@
+/* Copyright (C) 2007-2016 B.A.T.M.A.N. contributors:
+ *
+ * Marek Lindner, Simon Wunderlich
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * This file contains macros for maintaining compatibility with older versions
+ * of the Linux kernel.
+ */
+
+#ifndef _NET_BATMAN_ADV_COMPAT_LINUX_NETLINK_H_
+#define _NET_BATMAN_ADV_COMPAT_LINUX_NETLINK_H_
+
+#include <linux/version.h>
+#include_next <linux/netlink.h>
+
+#include <net/scm.h>
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 7, 0)
+
+struct batadv_netlink_skb_parms {
+ struct ucred creds; /* Skb credentials */
+ union {
+ __u32 portid;
+ __u32 pid;
+ };
+ __u32 dst_group;
+};
+
+#undef NETLINK_CB
+#define NETLINK_CB(skb) (*(struct batadv_netlink_skb_parms *)&((skb)->cb))
+
+#endif /* < KERNEL_VERSION(3, 7, 0) */
+
+#endif /* _NET_BATMAN_ADV_COMPAT_LINUX_NETLINK_H_ */
diff --git a/include/uapi/linux/batman_adv.h b/include/uapi/linux/batman_adv.h
index a908140..d2a9740 100644
--- a/include/uapi/linux/batman_adv.h
+++ b/include/uapi/linux/batman_adv.h
@@ -57,12 +57,14 @@ enum batadv_nl_attrs {
*
* @BATADV_CMD_UNSPEC: unspecified command to catch errors
* @BATADV_CMD_GET_MESH_INFO: Query basic information about batman-adv device
+ * @BATADV_CMD_GET_ROUTING_ALGOS: Query the list of routing algorithms.
* @__BATADV_CMD_AFTER_LAST: internal use
* @BATADV_CMD_MAX: highest used command number
*/
enum batadv_nl_commands {
BATADV_CMD_UNSPEC,
BATADV_CMD_GET_MESH_INFO,
+ BATADV_CMD_GET_ROUTING_ALGOS,
/* add new commands above here */
__BATADV_CMD_AFTER_LAST,
BATADV_CMD_MAX = __BATADV_CMD_AFTER_LAST - 1
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index e78b318..fe03721 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -35,6 +35,7 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/netdevice.h>
+#include <linux/netlink.h>
#include <linux/pkt_sched.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
@@ -46,7 +47,10 @@
#include <linux/string.h>
#include <linux/workqueue.h>
#include <net/dsfield.h>
+#include <net/genetlink.h>
+#include <net/netlink.h>
#include <net/rtnetlink.h>
+#include <uapi/linux/batman_adv.h>

#include "bat_algo.h"
#include "bridge_loop_avoidance.h"
@@ -612,6 +616,68 @@ int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
}

/**
+ * batadv_algo_dump_entry - fill in information about one supported routing
+ * algorithm
+ * @msg: netlink message to be sent back
+ * @portid: Port to reply to
+ * @seq: Sequence number of message
+ * @bat_algo_ops: Algorithm to be dumped
+ *
+ * Return: Error number, or 0 on success
+ */
+static int batadv_algo_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
+ struct batadv_algo_ops *bat_algo_ops)
+{
+ void *hdr;
+
+ hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
+ NLM_F_MULTI, BATADV_CMD_GET_ROUTING_ALGOS);
+ if (!hdr)
+ return -EMSGSIZE;
+
+ if (nla_put_string(msg, BATADV_ATTR_ALGO_NAME, bat_algo_ops->name))
+ goto nla_put_failure;
+
+ genlmsg_end(msg, hdr);
+ return 0;
+
+ nla_put_failure:
+ genlmsg_cancel(msg, hdr);
+ return -EMSGSIZE;
+}
+
+/**
+ * batadv_algo_dump - fill in information about supported routing
+ * algorithms
+ * @msg: netlink message to be sent back
+ * @cb: Parameters to the netlink request
+ *
+ * Return: Length of reply message.
+ */
+int batadv_algo_dump(struct sk_buff *msg, struct netlink_callback *cb)
+{
+ int portid = NETLINK_CB(cb->skb).portid;
+ struct batadv_algo_ops *bat_algo_ops;
+ int skip = cb->args[0];
+ int i = 0;
+
+ hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
+ if (i++ < skip)
+ continue;
+
+ if (batadv_algo_dump_entry(msg, portid, cb->nlh->nlmsg_seq,
+ bat_algo_ops)) {
+ i--;
+ break;
+ }
+ }
+
+ cb->args[0] = i;
+
+ return msg->len;
+}
+
+/**
* batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
* the header
* @skb: skb pointing to fragmented socket buffers
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index 832df0f..ea2ed80 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -191,6 +191,7 @@ enum batadv_uev_type {
#include "types.h"

struct batadv_ogm_packet;
+struct netlink_callback;
struct seq_file;
struct sk_buff;

@@ -221,6 +222,7 @@ void batadv_recv_handler_unregister(u8 packet_type);
int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops);
int batadv_algo_select(struct batadv_priv *bat_priv, char *name);
int batadv_algo_seq_print_text(struct seq_file *seq, void *offset);
+int batadv_algo_dump(struct sk_buff *msg, struct netlink_callback *cb);
__be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr);

/**
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c
index 54724b7..717d7d0 100644
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -25,8 +25,8 @@
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/netlink.h>
-#include <linux/stddef.h>
#include <linux/printk.h>
+#include <linux/stddef.h>
#include <net/genetlink.h>
#include <net/netlink.h>
#include <uapi/linux/batman_adv.h>
@@ -36,7 +36,7 @@

struct sk_buff;

-static struct genl_family batadv_netlink_family = {
+struct genl_family batadv_netlink_family = {
.id = GENL_ID_GENERATE,
.hdrsize = 0,
.name = BATADV_NL_NAME,
@@ -170,6 +170,12 @@ static struct genl_ops batadv_netlink_ops[] = {
.policy = batadv_netlink_policy,
.doit = batadv_netlink_get_mesh_info,
},
+ {
+ .cmd = BATADV_CMD_GET_ROUTING_ALGOS,
+ .flags = GENL_ADMIN_PERM,
+ .policy = batadv_netlink_policy,
+ .dumpit = batadv_algo_dump,
+ },
};

/**
diff --git a/net/batman-adv/netlink.h b/net/batman-adv/netlink.h
index fa152a8..0e4f134 100644
--- a/net/batman-adv/netlink.h
+++ b/net/batman-adv/netlink.h
@@ -18,7 +18,16 @@
#ifndef _NET_BATMAN_ADV_NETLINK_H_
#define _NET_BATMAN_ADV_NETLINK_H_

+#include <linux/compiler.h>
+#include <linux/genetlink.h>
+#include <net/genetlink.h>
+#include <net/netlink.h>
+
+struct nlmsghdr;
+
void batadv_netlink_register(void);
void batadv_netlink_unregister(void);

+extern struct genl_family batadv_netlink_family;
+
#endif /* _NET_BATMAN_ADV_NETLINK_H_ */
--
2.8.0.rc3