aboutsummaryrefslogtreecommitdiff
path: root/net/phonet/pn_netlink.c
blob: 1ceea1f92413d2d4b03d545152f339e628ab9b33 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
/*
 * File: pn_netlink.c
 *
 * Phonet netlink interface
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
 * Original author: Sakari Ailus <sakari.ailus@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/kernel.h>
#include <linux/netlink.h>
#include <linux/phonet.h>
#include <net/sock.h>
#include <net/phonet/pn_dev.h>

static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
		     u32 pid, u32 seq, int event);

static void rtmsg_notify(int event, struct net_device *dev, u8 addr)
{
	struct sk_buff *skb;
	int err = -ENOBUFS;

	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
			nla_total_size(1), GFP_KERNEL);
	if (skb == NULL)
		goto errout;
	err = fill_addr(skb, dev, addr, 0, 0, event);
	if (err < 0) {
		WARN_ON(err == -EMSGSIZE);
		kfree_skb(skb);
		goto errout;
	}
	err = rtnl_notify(skb, dev_net(dev), 0,
			  RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
errout:
	if (err < 0)
		rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
}

static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
	[IFA_LOCAL] = { .type = NLA_U8 },
};

static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
{
	struct net *net = sock_net(skb->sk);
	struct nlattr *tb[IFA_MAX+1];
	struct net_device *dev;
	struct ifaddrmsg *ifm;
	int err;
	u8 pnaddr;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	ASSERT_RTNL();

	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_phonet_policy);
	if (err < 0)
		return err;

	ifm = nlmsg_data(nlh);
	if (tb[IFA_LOCAL] == NULL)
		return -EINVAL;
	pnaddr = nla_get_u8(tb[IFA_LOCAL]);
	if (pnaddr & 3)
		/* Phonet addresses only have 6 high-order bits */
		return -EINVAL;

	dev = __dev_get_by_index(net, ifm->ifa_index);
	if (dev == NULL)
		return -ENODEV;

	if (nlh->nlmsg_type == RTM_NEWADDR)
		err = phonet_address_add(dev, pnaddr);
	else
		err = phonet_address_del(dev, pnaddr);
	if (!err)
		rtmsg_notify(nlh->nlmsg_type, dev, pnaddr);
	return err;
}

static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
			u32 pid, u32 seq, int event)
{
	struct ifaddrmsg *ifm;
	struct nlmsghdr *nlh;

	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), 0);
	if (nlh == NULL)
		return -EMSGSIZE;

	ifm = nlmsg_data(nlh);
	ifm->ifa_family = AF_PHONET;
	ifm->ifa_prefixlen = 0;
	ifm->ifa_flags = IFA_F_PERMANENT;
	ifm->ifa_scope = RT_SCOPE_LINK;
	ifm->ifa_index = dev->ifindex;
	NLA_PUT_U8(skb, IFA_LOCAL, addr);
	return nlmsg_end(skb, nlh);

nla_put_failure:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}

static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct phonet_device_list *pndevs;
	struct phonet_device *pnd;
	int dev_idx = 0, dev_start_idx = cb->args[0];
	int addr_idx = 0, addr_start_idx = cb->args[1];

	pndevs = phonet_device_list(sock_net(skb->sk));
	spin_lock_bh(&pndevs->lock);
	list_for_each_entry(pnd, &pndevs->list, list) {
		u8 addr;

		if (dev_idx > dev_start_idx)
			addr_start_idx = 0;
		if (dev_idx++ < dev_start_idx)
			continue;

		addr_idx = 0;
		for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
			addr = find_next_bit(pnd->addrs, 64, 1+addr)) {
			if (addr_idx++ < addr_start_idx)
				continue;

			if (fill_addr(skb, pnd->netdev, addr << 2,
					 NETLINK_CB(cb->skb).pid,
					cb->nlh->nlmsg_seq, RTM_NEWADDR))
				goto out;
		}
	}

out:
	spin_unlock_bh(&pndevs->lock);
	cb->args[0] = dev_idx;
	cb->args[1] = addr_idx;

	return skb->len;
}

int __init phonet_netlink_register(void)
{
	int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit, NULL);
	if (err)
		return err;

	/* Further __rtnl_register() cannot fail */
	__rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL);
	__rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit);
	return 0;
}