net/phonet/pn_netlink.c

   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 net *net = sock_net(skb->sk);
 127         struct phonet_device *pnd;
 128         int dev_idx = 0, dev_start_idx = cb->args[0];
 129         int addr_idx = 0, addr_start_idx = cb->args[1];
 130
 131         spin_lock_bh(&pndevs.lock);
 132         list_for_each_entry(pnd, &pndevs.list, list) {
 133                 u8 addr;
 134
 135                 if (!net_eq(dev_net(pnd->netdev), net))
 136                         continue;
 137                 if (dev_idx > dev_start_idx)
 138                         addr_start_idx = 0;
 139                 if (dev_idx++ < dev_start_idx)
 140                         continue;
 141
 142                 addr_idx = 0;
 143                 for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
 144                         addr = find_next_bit(pnd->addrs, 64, 1+addr)) {
 145                         if (addr_idx++ < addr_start_idx)
 146                                 continue;
 147
 148                         if (fill_addr(skb, pnd->netdev, addr << 2,
 149                                          NETLINK_CB(cb->skb).pid,
 150                                         cb->nlh->nlmsg_seq, RTM_NEWADDR))
 151                                 goto out;
 152                 }
 153         }
 154
 155 out:
 156         spin_unlock_bh(&pndevs.lock);
 157         cb->args[0] = dev_idx;
 158         cb->args[1] = addr_idx;
 159
 160         return skb->len;
 161 }
 162
 163 void __init phonet_netlink_register(void)
 164 {
 165         rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit, NULL);
 166         rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL);
 167         rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit);
 168 }