tipc: add bearer get/dump to new netlink api

Add TIPC_NL_BEARER_GET command to the new tipc netlink API.

This command supports dumping all data about all bearers or getting
all information about a specific bearer.

The information about a bearer includes name, link priorities and
domain.

Netlink logical layout of bearer get message:
-> bearer
    -> name

Netlink logical layout of returned bearer information:
-> bearer
    -> name
    -> link properties
        -> priority
        -> tolerance
        -> window
    -> domain

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 140 insertions, 0 deletions

diff --git a/include/uapi/linux/tipc_netlink.h b/include/uapi/linux/tipc_netlink.h
index b9b710faa229..249ec7e9952c 100644
--- a/include/uapi/linux/tipc_netlink.h
+++ b/include/uapi/linux/tipc_netlink.h
@@ -43,6 +43,7 @@ enum {
         TIPC_NL_LEGACY,
         TIPC_NL_BEARER_DISABLE,
         TIPC_NL_BEARER_ENABLE,
+        TIPC_NL_BEARER_GET,
 
         __TIPC_NL_CMD_MAX,
         TIPC_NL_CMD_MAX = __TIPC_NL_CMD_MAX - 1
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 59815be0ab98..d49b8c25dd11 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -640,6 +640,131 @@ void tipc_bearer_stop(void)
         }
 }
 
+/* Caller should hold rtnl_lock to protect the bearer */
+int __tipc_nl_add_bearer(struct tipc_nl_msg *msg, struct tipc_bearer *bearer)
+{
+        void *hdr;
+        struct nlattr *attrs;
+        struct nlattr *prop;
+
+        hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_v2_family,
+                          NLM_F_MULTI, TIPC_NL_BEARER_GET);
+        if (!hdr)
+                return -EMSGSIZE;
+
+        attrs = nla_nest_start(msg->skb, TIPC_NLA_BEARER);
+        if (!attrs)
+                goto msg_full;
+
+        if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
+                goto attr_msg_full;
+
+        prop = nla_nest_start(msg->skb, TIPC_NLA_BEARER_PROP);
+        if (!prop)
+                goto prop_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
+                goto prop_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
+                goto prop_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->window))
+                goto prop_msg_full;
+
+        nla_nest_end(msg->skb, prop);
+        nla_nest_end(msg->skb, attrs);
+        genlmsg_end(msg->skb, hdr);
+
+        return 0;
+
+prop_msg_full:
+        nla_nest_cancel(msg->skb, prop);
+attr_msg_full:
+        nla_nest_cancel(msg->skb, attrs);
+msg_full:
+        genlmsg_cancel(msg->skb, hdr);
+
+        return -EMSGSIZE;
+}
+
+int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        int err;
+        int i = cb->args[0];
+        struct tipc_bearer *bearer;
+        struct tipc_nl_msg msg;
+
+        if (i == MAX_BEARERS)
+                return 0;
+
+        msg.skb = skb;
+        msg.portid = NETLINK_CB(cb->skb).portid;
+        msg.seq = cb->nlh->nlmsg_seq;
+
+        rtnl_lock();
+        for (i = 0; i < MAX_BEARERS; i++) {
+                bearer = rtnl_dereference(bearer_list[i]);
+                if (!bearer)
+                        continue;
+
+                err = __tipc_nl_add_bearer(&msg, bearer);
+                if (err)
+                        break;
+        }
+        rtnl_unlock();
+
+        cb->args[0] = i;
+        return skb->len;
+}
+
+int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
+{
+        int err;
+        char *name;
+        struct sk_buff *rep;
+        struct tipc_bearer *bearer;
+        struct tipc_nl_msg msg;
+        struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+
+        if (!info->attrs[TIPC_NLA_BEARER])
+                return -EINVAL;
+
+        err = nla_parse_nested(attrs, TIPC_NLA_BEARER_MAX,
+                               info->attrs[TIPC_NLA_BEARER],
+                               tipc_nl_bearer_policy);
+        if (err)
+                return err;
+
+        if (!attrs[TIPC_NLA_BEARER_NAME])
+                return -EINVAL;
+        name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
+
+        rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+        if (!rep)
+                return -ENOMEM;
+
+        msg.skb = rep;
+        msg.portid = info->snd_portid;
+        msg.seq = info->snd_seq;
+
+        rtnl_lock();
+        bearer = tipc_bearer_find(name);
+        if (!bearer) {
+                err = -EINVAL;
+                goto err_out;
+        }
+
+        err = __tipc_nl_add_bearer(&msg, bearer);
+        if (err)
+                goto err_out;
+        rtnl_unlock();
+
+        return genlmsg_reply(rep, info);
+err_out:
+        rtnl_unlock();
+        nlmsg_free(rep);
+
+        return err;
+}
+
 int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
 {
         int err;
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index a87e8c78d862..2d07e35f91fc 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -180,6 +180,8 @@ extern struct tipc_media ib_media_info;
 
 int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info);
+int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb);
+int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info);
 
 int tipc_media_set_priority(const char *name, u32 new_value);
 int tipc_media_set_window(const char *name, u32 new_value);
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index af506ae0a129..0c00422512fa 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -112,6 +112,12 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
                 .cmd    = TIPC_NL_BEARER_ENABLE,
                 .doit   = tipc_nl_bearer_enable,
                 .policy = tipc_nl_policy,
+        },
+        {
+                .cmd    = TIPC_NL_BEARER_GET,
+                .doit   = tipc_nl_bearer_get,
+                .dumpit = tipc_nl_bearer_dump,
+                .policy = tipc_nl_policy,
         }
 };
 
diff --git a/net/tipc/netlink.h b/net/tipc/netlink.h
index e9980c0e2207..e34a3fca7d3d 100644
--- a/net/tipc/netlink.h
+++ b/net/tipc/netlink.h
@@ -38,4 +38,10 @@
 
 extern struct genl_family tipc_genl_v2_family;
 
+struct tipc_nl_msg {
+        struct sk_buff *skb;
+        u32 portid;
+        u32 seq;
+};
+
 #endif