xref: /linux/net/phonet/pn_netlink.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 /*
2  * File: pn_netlink.c
3  *
4  * Phonet netlink interface
5  *
6  * Copyright (C) 2008 Nokia Corporation.
7  *
8  * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
9  * Original author: Sakari Ailus <sakari.ailus@nokia.com>
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License
13  * version 2 as published by the Free Software Foundation.
14  *
15  * This program is distributed in the hope that it will be useful, but
16  * WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
23  * 02110-1301 USA
24  */
25 
26 #include <linux/kernel.h>
27 #include <linux/netlink.h>
28 #include <linux/phonet.h>
29 #include <net/sock.h>
30 #include <net/phonet/pn_dev.h>
31 
32 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
33 		     u32 pid, u32 seq, int event);
34 
35 static void rtmsg_notify(int event, struct net_device *dev, u8 addr)
36 {
37 	struct sk_buff *skb;
38 	int err = -ENOBUFS;
39 
40 	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
41 			nla_total_size(1), GFP_KERNEL);
42 	if (skb == NULL)
43 		goto errout;
44 	err = fill_addr(skb, dev, addr, 0, 0, event);
45 	if (err < 0) {
46 		WARN_ON(err == -EMSGSIZE);
47 		kfree_skb(skb);
48 		goto errout;
49 	}
50 	err = rtnl_notify(skb, dev_net(dev), 0,
51 			  RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
52 errout:
53 	if (err < 0)
54 		rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
55 }
56 
57 static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
58 	[IFA_LOCAL] = { .type = NLA_U8 },
59 };
60 
61 static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
62 {
63 	struct net *net = sock_net(skb->sk);
64 	struct nlattr *tb[IFA_MAX+1];
65 	struct net_device *dev;
66 	struct ifaddrmsg *ifm;
67 	int err;
68 	u8 pnaddr;
69 
70 	if (!capable(CAP_SYS_ADMIN))
71 		return -EPERM;
72 
73 	ASSERT_RTNL();
74 
75 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_phonet_policy);
76 	if (err < 0)
77 		return err;
78 
79 	ifm = nlmsg_data(nlh);
80 	if (tb[IFA_LOCAL] == NULL)
81 		return -EINVAL;
82 	pnaddr = nla_get_u8(tb[IFA_LOCAL]);
83 	if (pnaddr & 3)
84 		/* Phonet addresses only have 6 high-order bits */
85 		return -EINVAL;
86 
87 	dev = __dev_get_by_index(net, ifm->ifa_index);
88 	if (dev == NULL)
89 		return -ENODEV;
90 
91 	if (nlh->nlmsg_type == RTM_NEWADDR)
92 		err = phonet_address_add(dev, pnaddr);
93 	else
94 		err = phonet_address_del(dev, pnaddr);
95 	if (!err)
96 		rtmsg_notify(nlh->nlmsg_type, dev, pnaddr);
97 	return err;
98 }
99 
100 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
101 			u32 pid, u32 seq, int event)
102 {
103 	struct ifaddrmsg *ifm;
104 	struct nlmsghdr *nlh;
105 
106 	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), 0);
107 	if (nlh == NULL)
108 		return -EMSGSIZE;
109 
110 	ifm = nlmsg_data(nlh);
111 	ifm->ifa_family = AF_PHONET;
112 	ifm->ifa_prefixlen = 0;
113 	ifm->ifa_flags = IFA_F_PERMANENT;
114 	ifm->ifa_scope = RT_SCOPE_LINK;
115 	ifm->ifa_index = dev->ifindex;
116 	NLA_PUT_U8(skb, IFA_LOCAL, addr);
117 	return nlmsg_end(skb, nlh);
118 
119 nla_put_failure:
120 	nlmsg_cancel(skb, nlh);
121 	return -EMSGSIZE;
122 }
123 
124 static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
125 {
126 	struct phonet_device *pnd;
127 	int dev_idx = 0, dev_start_idx = cb->args[0];
128 	int addr_idx = 0, addr_start_idx = cb->args[1];
129 
130 	spin_lock_bh(&pndevs.lock);
131 	list_for_each_entry(pnd, &pndevs.list, list) {
132 		u8 addr;
133 
134 		if (dev_idx > dev_start_idx)
135 			addr_start_idx = 0;
136 		if (dev_idx++ < dev_start_idx)
137 			continue;
138 
139 		addr_idx = 0;
140 		for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
141 			addr = find_next_bit(pnd->addrs, 64, 1+addr)) {
142 			if (addr_idx++ < addr_start_idx)
143 				continue;
144 
145 			if (fill_addr(skb, pnd->netdev, addr << 2,
146 					 NETLINK_CB(cb->skb).pid,
147 					cb->nlh->nlmsg_seq, RTM_NEWADDR))
148 				goto out;
149 		}
150 	}
151 
152 out:
153 	spin_unlock_bh(&pndevs.lock);
154 	cb->args[0] = dev_idx;
155 	cb->args[1] = addr_idx;
156 
157 	return skb->len;
158 }
159 
160 void __init phonet_netlink_register(void)
161 {
162 	rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit, NULL);
163 	rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL);
164 	rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit);
165 }
166