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 <linux/slab.h>
  30 #include <net/sock.h>
  31 #include <net/phonet/pn_dev.h>
  32
  33 /* Device address handling */
  34
  35 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
  36                      u32 pid, u32 seq, int event);
  37
  38 void phonet_address_notify(int event, struct net_device *dev, u8 addr)
  39 {
  40         struct sk_buff *skb;
  41         int err = -ENOBUFS;
  42
  43         skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
  44                         nla_total_size(1), GFP_KERNEL);
  45         if (skb == NULL)
  46                 goto errout;
  47         err = fill_addr(skb, dev, addr, 0, 0, event);
  48         if (err < 0) {
  49                 WARN_ON(err == -EMSGSIZE);
  50                 kfree_skb(skb);
  51                 goto errout;
  52         }
  53         rtnl_notify(skb, dev_net(dev), 0,
  54                     RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
  55         return;
  56 errout:
  57         rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
  58 }
  59
  60 static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
  61         [IFA_LOCAL] = { .type = NLA_U8 },
  62 };
  63
  64 static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
  65 {
  66         struct net *net = sock_net(skb->sk);
  67         struct nlattr *tb[IFA_MAX+1];
  68         struct net_device *dev;
  69         struct ifaddrmsg *ifm;
  70         int err;
  71         u8 pnaddr;
  72
  73         if (!capable(CAP_SYS_ADMIN))
  74                 return -EPERM;
  75
  76         ASSERT_RTNL();
  77
  78         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_phonet_policy);
  79         if (err < 0)
  80                 return err;
  81
  82         ifm = nlmsg_data(nlh);
  83         if (tb[IFA_LOCAL] == NULL)
  84                 return -EINVAL;
  85         pnaddr = nla_get_u8(tb[IFA_LOCAL]);
  86         if (pnaddr & 3)
  87                 /* Phonet addresses only have 6 high-order bits */
  88                 return -EINVAL;
  89
  90         dev = __dev_get_by_index(net, ifm->ifa_index);
  91         if (dev == NULL)
  92                 return -ENODEV;
  93
  94         if (nlh->nlmsg_type == RTM_NEWADDR)
  95                 err = phonet_address_add(dev, pnaddr);
  96         else
  97                 err = phonet_address_del(dev, pnaddr);
  98         if (!err)
  99                 phonet_address_notify(nlh->nlmsg_type, dev, pnaddr);
 100         return err;
 101 }
 102
 103 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
 104                         u32 pid, u32 seq, int event)
 105 {
 106         struct ifaddrmsg *ifm;
 107         struct nlmsghdr *nlh;
 108
 109         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), 0);
 110         if (nlh == NULL)
 111                 return -EMSGSIZE;
 112
 113         ifm = nlmsg_data(nlh);
 114         ifm->ifa_family = AF_PHONET;
 115         ifm->ifa_prefixlen = 0;
 116         ifm->ifa_flags = IFA_F_PERMANENT;
 117         ifm->ifa_scope = RT_SCOPE_LINK;
 118         ifm->ifa_index = dev->ifindex;
 119         NLA_PUT_U8(skb, IFA_LOCAL, addr);
 120         return nlmsg_end(skb, nlh);
 121
 122 nla_put_failure:
 123         nlmsg_cancel(skb, nlh);
 124         return -EMSGSIZE;
 125 }
 126
 127 static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 128 {
 129         struct phonet_device_list *pndevs;
 130         struct phonet_device *pnd;
 131         int dev_idx = 0, dev_start_idx = cb->args[0];
 132         int addr_idx = 0, addr_start_idx = cb->args[1];
 133
 134         pndevs = phonet_device_list(sock_net(skb->sk));
 135         rcu_read_lock();
 136         list_for_each_entry_rcu(pnd, &pndevs->list, list) {
 137                 u8 addr;
 138
 139                 if (dev_idx > dev_start_idx)
 140                         addr_start_idx = 0;
 141                 if (dev_idx++ < dev_start_idx)
 142                         continue;
 143
 144                 addr_idx = 0;
 145                 for_each_set_bit(addr, pnd->addrs, 64) {
 146                         if (addr_idx++ < addr_start_idx)
 147                                 continue;
 148
 149                         if (fill_addr(skb, pnd->netdev, addr << 2,
 150                                          NETLINK_CB(cb->skb).pid,
 151                                         cb->nlh->nlmsg_seq, RTM_NEWADDR) < 0)
 152                                 goto out;
 153                 }
 154         }
 155
 156 out:
 157         rcu_read_unlock();
 158         cb->args[0] = dev_idx;
 159         cb->args[1] = addr_idx;
 160
 161         return skb->len;
 162 }
 163
 164 /* Routes handling */
 165
 166 static int fill_route(struct sk_buff *skb, struct net_device *dev, u8 dst,
 167                         u32 pid, u32 seq, int event)
 168 {
 169         struct rtmsg *rtm;
 170         struct nlmsghdr *nlh;
 171
 172         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), 0);
 173         if (nlh == NULL)
 174                 return -EMSGSIZE;
 175
 176         rtm = nlmsg_data(nlh);
 177         rtm->rtm_family = AF_PHONET;
 178         rtm->rtm_dst_len = 6;
 179         rtm->rtm_src_len = 0;
 180         rtm->rtm_tos = 0;
 181         rtm->rtm_table = RT_TABLE_MAIN;
 182         rtm->rtm_protocol = RTPROT_STATIC;
 183         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
 184         rtm->rtm_type = RTN_UNICAST;
 185         rtm->rtm_flags = 0;
 186         NLA_PUT_U8(skb, RTA_DST, dst);
 187         NLA_PUT_U32(skb, RTA_OIF, dev->ifindex);
 188         return nlmsg_end(skb, nlh);
 189
 190 nla_put_failure:
 191         nlmsg_cancel(skb, nlh);
 192         return -EMSGSIZE;
 193 }
 194
 195 void rtm_phonet_notify(int event, struct net_device *dev, u8 dst)
 196 {
 197         struct sk_buff *skb;
 198         int err = -ENOBUFS;
 199
 200         skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
 201                         nla_total_size(1) + nla_total_size(4), GFP_KERNEL);
 202         if (skb == NULL)
 203                 goto errout;
 204         err = fill_route(skb, dev, dst, 0, 0, event);
 205         if (err < 0) {
 206                 WARN_ON(err == -EMSGSIZE);
 207                 kfree_skb(skb);
 208                 goto errout;
 209         }
 210         rtnl_notify(skb, dev_net(dev), 0,
 211                           RTNLGRP_PHONET_ROUTE, NULL, GFP_KERNEL);
 212         return;
 213 errout:
 214         rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_ROUTE, err);
 215 }
 216
 217 static const struct nla_policy rtm_phonet_policy[RTA_MAX+1] = {
 218         [RTA_DST] = { .type = NLA_U8 },
 219         [RTA_OIF] = { .type = NLA_U32 },
 220 };
 221
 222 static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
 223 {
 224         struct net *net = sock_net(skb->sk);
 225         struct nlattr *tb[RTA_MAX+1];
 226         struct net_device *dev;
 227         struct rtmsg *rtm;
 228         int err;
 229         u8 dst;
 230
 231         if (!capable(CAP_SYS_ADMIN))
 232                 return -EPERM;
 233
 234         ASSERT_RTNL();
 235
 236         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_phonet_policy);
 237         if (err < 0)
 238                 return err;
 239
 240         rtm = nlmsg_data(nlh);
 241         if (rtm->rtm_table != RT_TABLE_MAIN || rtm->rtm_type != RTN_UNICAST)
 242                 return -EINVAL;
 243         if (tb[RTA_DST] == NULL || tb[RTA_OIF] == NULL)
 244                 return -EINVAL;
 245         dst = nla_get_u8(tb[RTA_DST]);
 246         if (dst & 3) /* Phonet addresses only have 6 high-order bits */
 247                 return -EINVAL;
 248
 249         dev = __dev_get_by_index(net, nla_get_u32(tb[RTA_OIF]));
 250         if (dev == NULL)
 251                 return -ENODEV;
 252
 253         if (nlh->nlmsg_type == RTM_NEWROUTE)
 254                 err = phonet_route_add(dev, dst);
 255         else
 256                 err = phonet_route_del(dev, dst);
 257         if (!err)
 258                 rtm_phonet_notify(nlh->nlmsg_type, dev, dst);
 259         return err;
 260 }
 261
 262 static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 263 {
 264         struct net *net = sock_net(skb->sk);
 265         u8 addr, addr_idx = 0, addr_start_idx = cb->args[0];
 266
 267         rcu_read_lock();
 268         for (addr = 0; addr < 64; addr++) {
 269                 struct net_device *dev;
 270
 271                 dev = phonet_route_get_rcu(net, addr << 2);
 272                 if (!dev)
 273                         continue;
 274
 275                 if (addr_idx++ < addr_start_idx)
 276                         continue;
 277                 if (fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).pid,
 278                                 cb->nlh->nlmsg_seq, RTM_NEWROUTE))
 279                         goto out;
 280         }
 281
 282 out:
 283         rcu_read_unlock();
 284         cb->args[0] = addr_idx;
 285         cb->args[1] = 0;
 286
 287         return skb->len;
 288 }
 289
 290 int __init phonet_netlink_register(void)
 291 {
 292         int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit,
 293                                   NULL, NULL);
 294         if (err)
 295                 return err;
 296
 297         /* Further __rtnl_register() cannot fail */
 298         __rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL, NULL);
 299         __rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit, NULL);
 300         __rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL, NULL);
 301         __rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL, NULL);
 302         __rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit, NULL);
 303         return 0;
 304 }