tipc: add media get/dump to new netlink api

Add TIPC_NL_MEDIA_GET command to the new tipc netlink API.

This command supports dumping all information about all defined
media as well as getting all information about a specific media.

The information about a media includes name and link properties.

Netlink logical layout of media get response message:
-> media
    -> name
    -> link properties
        -> tolerance
        -> priority
        -> window

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>

3 files changed, 135 insertions, 0 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 6d547d0b3f31..26630a51fcae 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -61,6 +61,12 @@ tipc_nl_bearer_policy[TIPC_NLA_BEARER_MAX + 1]	= {
         [TIPC_NLA_BEARER_DOMAIN]                = { .type = NLA_U32 }
 };
 
+static const struct nla_policy tipc_nl_media_policy[TIPC_NLA_MEDIA_MAX + 1] = {
+        [TIPC_NLA_MEDIA_UNSPEC]         = { .type = NLA_UNSPEC },
+        [TIPC_NLA_MEDIA_NAME]           = { .type = NLA_STRING },
+        [TIPC_NLA_MEDIA_PROP]           = { .type = NLA_NESTED }
+};
+
 struct tipc_bearer __rcu *bearer_list[MAX_BEARERS + 1];
 
 static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down);
@@ -898,3 +904,122 @@ int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
 
         return 0;
 }
+
+int __tipc_nl_add_media(struct tipc_nl_msg *msg, struct tipc_media *media)
+{
+        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_MEDIA_GET);
+        if (!hdr)
+                return -EMSGSIZE;
+
+        attrs = nla_nest_start(msg->skb, TIPC_NLA_MEDIA);
+        if (!attrs)
+                goto msg_full;
+
+        if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
+                goto attr_msg_full;
+
+        prop = nla_nest_start(msg->skb, TIPC_NLA_MEDIA_PROP);
+        if (!prop)
+                goto prop_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
+                goto prop_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
+                goto prop_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->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_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        int err;
+        int i = cb->args[0];
+        struct tipc_nl_msg msg;
+
+        if (i == MAX_MEDIA)
+                return 0;
+
+        msg.skb = skb;
+        msg.portid = NETLINK_CB(cb->skb).portid;
+        msg.seq = cb->nlh->nlmsg_seq;
+
+        rtnl_lock();
+        for (; media_info_array[i] != NULL; i++) {
+                err = __tipc_nl_add_media(&msg, media_info_array[i]);
+                if (err)
+                        break;
+        }
+        rtnl_unlock();
+
+        cb->args[0] = i;
+        return skb->len;
+}
+
+int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
+{
+        int err;
+        char *name;
+        struct tipc_nl_msg msg;
+        struct tipc_media *media;
+        struct sk_buff *rep;
+        struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+
+        if (!info->attrs[TIPC_NLA_MEDIA])
+                return -EINVAL;
+
+        err = nla_parse_nested(attrs, TIPC_NLA_MEDIA_MAX,
+                               info->attrs[TIPC_NLA_MEDIA],
+                               tipc_nl_media_policy);
+        if (err)
+                return err;
+
+        if (!attrs[TIPC_NLA_MEDIA_NAME])
+                return -EINVAL;
+        name = nla_data(attrs[TIPC_NLA_MEDIA_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();
+        media = tipc_media_find(name);
+        if (!media) {
+                err = -EINVAL;
+                goto err_out;
+        }
+
+        err = __tipc_nl_add_media(&msg, media);
+        if (err)
+                goto err_out;
+        rtnl_unlock();
+
+        return genlmsg_reply(rep, info);
+err_out:
+        rtnl_unlock();
+        nlmsg_free(rep);
+
+        return err;
+}
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index c6cf9df31375..bacd225bccfb 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -184,6 +184,9 @@ 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_nl_bearer_set(struct sk_buff *skb, struct genl_info *info);
 
+int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb);
+int tipc_nl_media_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);
 void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a);
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index 68bfd11f232d..742e51a0afbb 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -77,6 +77,7 @@ static const struct nla_policy tipc_nl_policy[TIPC_NLA_MAX + 1] = {
         [TIPC_NLA_SOCK]         = { .type = NLA_NESTED, },
         [TIPC_NLA_PUBL]         = { .type = NLA_NESTED, },
         [TIPC_NLA_LINK]         = { .type = NLA_NESTED, },
+        [TIPC_NLA_MEDIA]        = { .type = NLA_NESTED, },
 };
 
 /* Legacy ASCII API */
@@ -154,6 +155,12 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
                 .cmd    = TIPC_NL_LINK_RESET_STATS,
                 .doit   = tipc_nl_link_reset_stats,
                 .policy = tipc_nl_policy,
+        },
+        {
+                .cmd    = TIPC_NL_MEDIA_GET,
+                .doit   = tipc_nl_media_get,
+                .dumpit = tipc_nl_media_dump,
+                .policy = tipc_nl_policy,
         }
 };