GNU Linux-libre 4.9.308-gnu1
[releases.git] / fs / dlm / netlink.c
1 /*
2  * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.
3  *
4  * This copyrighted material is made available to anyone wishing to use,
5  * modify, copy, or redistribute it subject to the terms and conditions
6  * of the GNU General Public License v.2.
7  */
8
9 #include <net/genetlink.h>
10 #include <linux/dlm.h>
11 #include <linux/dlm_netlink.h>
12 #include <linux/gfp.h>
13
14 #include "dlm_internal.h"
15
16 static uint32_t dlm_nl_seqnum;
17 static uint32_t listener_nlportid;
18
19 static struct genl_family family = {
20         .id             = GENL_ID_GENERATE,
21         .name           = DLM_GENL_NAME,
22         .version        = DLM_GENL_VERSION,
23 };
24
25 static int prepare_data(u8 cmd, struct sk_buff **skbp, size_t size)
26 {
27         struct sk_buff *skb;
28         void *data;
29
30         skb = genlmsg_new(size, GFP_NOFS);
31         if (!skb)
32                 return -ENOMEM;
33
34         /* add the message headers */
35         data = genlmsg_put(skb, 0, dlm_nl_seqnum++, &family, 0, cmd);
36         if (!data) {
37                 nlmsg_free(skb);
38                 return -EINVAL;
39         }
40
41         *skbp = skb;
42         return 0;
43 }
44
45 static struct dlm_lock_data *mk_data(struct sk_buff *skb)
46 {
47         struct nlattr *ret;
48
49         ret = nla_reserve(skb, DLM_TYPE_LOCK, sizeof(struct dlm_lock_data));
50         if (!ret)
51                 return NULL;
52         return nla_data(ret);
53 }
54
55 static int send_data(struct sk_buff *skb)
56 {
57         struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
58         void *data = genlmsg_data(genlhdr);
59
60         genlmsg_end(skb, data);
61
62         return genlmsg_unicast(&init_net, skb, listener_nlportid);
63 }
64
65 static int user_cmd(struct sk_buff *skb, struct genl_info *info)
66 {
67         listener_nlportid = info->snd_portid;
68         printk("user_cmd nlpid %u\n", listener_nlportid);
69         return 0;
70 }
71
72 static struct genl_ops dlm_nl_ops[] = {
73         {
74                 .cmd    = DLM_CMD_HELLO,
75                 .doit   = user_cmd,
76         },
77 };
78
79 int __init dlm_netlink_init(void)
80 {
81         return genl_register_family_with_ops(&family, dlm_nl_ops);
82 }
83
84 void dlm_netlink_exit(void)
85 {
86         genl_unregister_family(&family);
87 }
88
89 static void fill_data(struct dlm_lock_data *data, struct dlm_lkb *lkb)
90 {
91         struct dlm_rsb *r = lkb->lkb_resource;
92
93         memset(data, 0, sizeof(struct dlm_lock_data));
94
95         data->version = DLM_LOCK_DATA_VERSION;
96         data->nodeid = lkb->lkb_nodeid;
97         data->ownpid = lkb->lkb_ownpid;
98         data->id = lkb->lkb_id;
99         data->remid = lkb->lkb_remid;
100         data->status = lkb->lkb_status;
101         data->grmode = lkb->lkb_grmode;
102         data->rqmode = lkb->lkb_rqmode;
103         if (lkb->lkb_ua)
104                 data->xid = lkb->lkb_ua->xid;
105         if (r) {
106                 data->lockspace_id = r->res_ls->ls_global_id;
107                 data->resource_namelen = r->res_length;
108                 memcpy(data->resource_name, r->res_name, r->res_length);
109         }
110 }
111
112 void dlm_timeout_warn(struct dlm_lkb *lkb)
113 {
114         struct sk_buff *uninitialized_var(send_skb);
115         struct dlm_lock_data *data;
116         size_t size;
117         int rv;
118
119         size = nla_total_size(sizeof(struct dlm_lock_data)) +
120                nla_total_size(0); /* why this? */
121
122         rv = prepare_data(DLM_CMD_TIMEOUT, &send_skb, size);
123         if (rv < 0)
124                 return;
125
126         data = mk_data(send_skb);
127         if (!data) {
128                 nlmsg_free(send_skb);
129                 return;
130         }
131
132         fill_data(data, lkb);
133
134         send_data(send_skb);
135 }
136