1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.
4  */
5 
6 #include <net/genetlink.h>
7 #include <linux/dlm.h>
8 #include <linux/dlm_netlink.h>
9 #include <linux/gfp.h>
10 
11 #include "dlm_internal.h"
12 
13 static uint32_t dlm_nl_seqnum;
14 static uint32_t listener_nlportid;
15 
16 static struct genl_family family;
17 
prepare_data(u8 cmd,struct sk_buff ** skbp,size_t size)18 static int prepare_data(u8 cmd, struct sk_buff **skbp, size_t size)
19 {
20 	struct sk_buff *skb;
21 	void *data;
22 
23 	skb = genlmsg_new(size, GFP_NOFS);
24 	if (!skb)
25 		return -ENOMEM;
26 
27 	/* add the message headers */
28 	data = genlmsg_put(skb, 0, dlm_nl_seqnum++, &family, 0, cmd);
29 	if (!data) {
30 		nlmsg_free(skb);
31 		return -EINVAL;
32 	}
33 
34 	*skbp = skb;
35 	return 0;
36 }
37 
mk_data(struct sk_buff * skb)38 static struct dlm_lock_data *mk_data(struct sk_buff *skb)
39 {
40 	struct nlattr *ret;
41 
42 	ret = nla_reserve(skb, DLM_TYPE_LOCK, sizeof(struct dlm_lock_data));
43 	if (!ret)
44 		return NULL;
45 	return nla_data(ret);
46 }
47 
send_data(struct sk_buff * skb)48 static int send_data(struct sk_buff *skb)
49 {
50 	struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
51 	void *data = genlmsg_data(genlhdr);
52 
53 	genlmsg_end(skb, data);
54 
55 	return genlmsg_unicast(&init_net, skb, listener_nlportid);
56 }
57 
user_cmd(struct sk_buff * skb,struct genl_info * info)58 static int user_cmd(struct sk_buff *skb, struct genl_info *info)
59 {
60 	listener_nlportid = info->snd_portid;
61 	printk("user_cmd nlpid %u\n", listener_nlportid);
62 	return 0;
63 }
64 
65 static const struct genl_small_ops dlm_nl_ops[] = {
66 	{
67 		.cmd	= DLM_CMD_HELLO,
68 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
69 		.doit	= user_cmd,
70 	},
71 };
72 
73 static struct genl_family family __ro_after_init = {
74 	.name		= DLM_GENL_NAME,
75 	.version	= DLM_GENL_VERSION,
76 	.small_ops	= dlm_nl_ops,
77 	.n_small_ops	= ARRAY_SIZE(dlm_nl_ops),
78 	.module		= THIS_MODULE,
79 };
80 
dlm_netlink_init(void)81 int __init dlm_netlink_init(void)
82 {
83 	return genl_register_family(&family);
84 }
85 
dlm_netlink_exit(void)86 void dlm_netlink_exit(void)
87 {
88 	genl_unregister_family(&family);
89 }
90 
fill_data(struct dlm_lock_data * data,struct dlm_lkb * lkb)91 static void fill_data(struct dlm_lock_data *data, struct dlm_lkb *lkb)
92 {
93 	struct dlm_rsb *r = lkb->lkb_resource;
94 
95 	memset(data, 0, sizeof(struct dlm_lock_data));
96 
97 	data->version = DLM_LOCK_DATA_VERSION;
98 	data->nodeid = lkb->lkb_nodeid;
99 	data->ownpid = lkb->lkb_ownpid;
100 	data->id = lkb->lkb_id;
101 	data->remid = lkb->lkb_remid;
102 	data->status = lkb->lkb_status;
103 	data->grmode = lkb->lkb_grmode;
104 	data->rqmode = lkb->lkb_rqmode;
105 	if (lkb->lkb_ua)
106 		data->xid = lkb->lkb_ua->xid;
107 	if (r) {
108 		data->lockspace_id = r->res_ls->ls_global_id;
109 		data->resource_namelen = r->res_length;
110 		memcpy(data->resource_name, r->res_name, r->res_length);
111 	}
112 }
113 
dlm_timeout_warn(struct dlm_lkb * lkb)114 void dlm_timeout_warn(struct dlm_lkb *lkb)
115 {
116 	struct sk_buff *send_skb;
117 	struct dlm_lock_data *data;
118 	size_t size;
119 	int rv;
120 
121 	size = nla_total_size(sizeof(struct dlm_lock_data)) +
122 	       nla_total_size(0); /* why this? */
123 
124 	rv = prepare_data(DLM_CMD_TIMEOUT, &send_skb, size);
125 	if (rv < 0)
126 		return;
127 
128 	data = mk_data(send_skb);
129 	if (!data) {
130 		nlmsg_free(send_skb);
131 		return;
132 	}
133 
134 	fill_data(data, lkb);
135 
136 	send_data(send_skb);
137 }
138 
139