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_nlpid;
18 
19 static struct genl_family family = {
20 	.id		= GENL_ID_GENERATE,
21 	.name		= DLM_GENL_NAME,
22 	.version	= DLM_GENL_VERSION,
23 };
24 
prepare_data(u8 cmd,struct sk_buff ** skbp,size_t size)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 
mk_data(struct sk_buff * skb)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 
send_data(struct sk_buff * skb)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 	int rv;
60 
61 	rv = genlmsg_end(skb, data);
62 	if (rv < 0) {
63 		nlmsg_free(skb);
64 		return rv;
65 	}
66 
67 	return genlmsg_unicast(&init_net, skb, listener_nlpid);
68 }
69 
user_cmd(struct sk_buff * skb,struct genl_info * info)70 static int user_cmd(struct sk_buff *skb, struct genl_info *info)
71 {
72 	listener_nlpid = info->snd_pid;
73 	printk("user_cmd nlpid %u\n", listener_nlpid);
74 	return 0;
75 }
76 
77 static struct genl_ops dlm_nl_ops = {
78 	.cmd		= DLM_CMD_HELLO,
79 	.doit		= user_cmd,
80 };
81 
dlm_netlink_init(void)82 int __init dlm_netlink_init(void)
83 {
84 	return genl_register_family_with_ops(&family, &dlm_nl_ops, 1);
85 }
86 
dlm_netlink_exit(void)87 void dlm_netlink_exit(void)
88 {
89 	genl_unregister_family(&family);
90 }
91 
fill_data(struct dlm_lock_data * data,struct dlm_lkb * lkb)92 static void fill_data(struct dlm_lock_data *data, struct dlm_lkb *lkb)
93 {
94 	struct dlm_rsb *r = lkb->lkb_resource;
95 
96 	memset(data, 0, sizeof(struct dlm_lock_data));
97 
98 	data->version = DLM_LOCK_DATA_VERSION;
99 	data->nodeid = lkb->lkb_nodeid;
100 	data->ownpid = lkb->lkb_ownpid;
101 	data->id = lkb->lkb_id;
102 	data->remid = lkb->lkb_remid;
103 	data->status = lkb->lkb_status;
104 	data->grmode = lkb->lkb_grmode;
105 	data->rqmode = lkb->lkb_rqmode;
106 	if (lkb->lkb_ua)
107 		data->xid = lkb->lkb_ua->xid;
108 	if (r) {
109 		data->lockspace_id = r->res_ls->ls_global_id;
110 		data->resource_namelen = r->res_length;
111 		memcpy(data->resource_name, r->res_name, r->res_length);
112 	}
113 }
114 
dlm_timeout_warn(struct dlm_lkb * lkb)115 void dlm_timeout_warn(struct dlm_lkb *lkb)
116 {
117 	struct sk_buff *uninitialized_var(send_skb);
118 	struct dlm_lock_data *data;
119 	size_t size;
120 	int rv;
121 
122 	size = nla_total_size(sizeof(struct dlm_lock_data)) +
123 	       nla_total_size(0); /* why this? */
124 
125 	rv = prepare_data(DLM_CMD_TIMEOUT, &send_skb, size);
126 	if (rv < 0)
127 		return;
128 
129 	data = mk_data(send_skb);
130 	if (!data) {
131 		nlmsg_free(send_skb);
132 		return;
133 	}
134 
135 	fill_data(data, lkb);
136 
137 	send_data(send_skb);
138 }
139 
140