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  * Authors: Sakari Ailus <sakari.ailus@nokia.com>
   9  *          Remi Denis-Courmont
  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 portid, 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)
  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 (!netlink_capable(skb, CAP_NET_ADMIN))
  74                 return -EPERM;
  75
  76         if (!netlink_capable(skb, CAP_SYS_ADMIN))
  77                 return -EPERM;
  78
  79         ASSERT_RTNL();
  80
  81         err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_phonet_policy);
  82         if (err < 0)
  83                 return err;
  84
  85         ifm = nlmsg_data(nlh);
  86         if (tb[IFA_LOCAL] == NULL)
  87                 return -EINVAL;
  88         pnaddr = nla_get_u8(tb[IFA_LOCAL]);
  89         if (pnaddr & 3)
  90                 /* Phonet addresses only have 6 high-order bits */
  91                 return -EINVAL;
  92
  93         dev = __dev_get_by_index(net, ifm->ifa_index);
  94         if (dev == NULL)
  95                 return -ENODEV;
  96
  97         if (nlh->nlmsg_type == RTM_NEWADDR)
  98                 err = phonet_address_add(dev, pnaddr);
  99         else
 100                 err = phonet_address_del(dev, pnaddr);
 101         if (!err)
 102                 phonet_address_notify(nlh->nlmsg_type, dev, pnaddr);
 103         return err;
 104 }
 105
 106 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
 107                         u32 portid, u32 seq, int event)
 108 {
 109         struct ifaddrmsg *ifm;
 110         struct nlmsghdr *nlh;
 111
 112         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*ifm), 0);
 113         if (nlh == NULL)
 114                 return -EMSGSIZE;
 115
 116         ifm = nlmsg_data(nlh);
 117         ifm->ifa_family = AF_PHONET;
 118         ifm->ifa_prefixlen = 0;
 119         ifm->ifa_flags = IFA_F_PERMANENT;
 120         ifm->ifa_scope = RT_SCOPE_LINK;
 121         ifm->ifa_index = dev->ifindex;
 122         if (nla_put_u8(skb, IFA_LOCAL, addr))
 123                 goto nla_put_failure;
 124         return nlmsg_end(skb, nlh);
 125
 126 nla_put_failure:
 127         nlmsg_cancel(skb, nlh);
 128         return -EMSGSIZE;
 129 }
 130
 131 static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 132 {
 133         struct phonet_device_list *pndevs;
 134         struct phonet_device *pnd;
 135         int dev_idx = 0, dev_start_idx = cb->args[0];
 136         int addr_idx = 0, addr_start_idx = cb->args[1];
 137
 138         pndevs = phonet_device_list(sock_net(skb->sk));
 139         rcu_read_lock();
 140         list_for_each_entry_rcu(pnd, &pndevs->list, list) {
 141                 u8 addr;
 142
 143                 if (dev_idx > dev_start_idx)
 144                         addr_start_idx = 0;
 145                 if (dev_idx++ < dev_start_idx)
 146                         continue;
 147
 148                 addr_idx = 0;
 149                 for_each_set_bit(addr, pnd->addrs, 64) {
 150                         if (addr_idx++ < addr_start_idx)
 151                                 continue;
 152
 153                         if (fill_addr(skb, pnd->netdev, addr << 2,
 154                                          NETLINK_CB(cb->skb).portid,
 155                                         cb->nlh->nlmsg_seq, RTM_NEWADDR) < 0)
 156                                 goto out;
 157                 }
 158         }
 159
 160 out:
 161         rcu_read_unlock();
 162         cb->args[0] = dev_idx;
 163         cb->args[1] = addr_idx;
 164
 165         return skb->len;
 166 }
 167
 168 /* Routes handling */
 169
 170 static int fill_route(struct sk_buff *skb, struct net_device *dev, u8 dst,
 171                         u32 portid, u32 seq, int event)
 172 {
 173         struct rtmsg *rtm;
 174         struct nlmsghdr *nlh;
 175
 176         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), 0);
 177         if (nlh == NULL)
 178                 return -EMSGSIZE;
 179
 180         rtm = nlmsg_data(nlh);
 181         rtm->rtm_family = AF_PHONET;
 182         rtm->rtm_dst_len = 6;
 183         rtm->rtm_src_len = 0;
 184         rtm->rtm_tos = 0;
 185         rtm->rtm_table = RT_TABLE_MAIN;
 186         rtm->rtm_protocol = RTPROT_STATIC;
 187         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
 188         rtm->rtm_type = RTN_UNICAST;
 189         rtm->rtm_flags = 0;
 190         if (nla_put_u8(skb, RTA_DST, dst) ||
 191             nla_put_u32(skb, RTA_OIF, dev->ifindex))
 192                 goto nla_put_failure;
 193         return nlmsg_end(skb, nlh);
 194
 195 nla_put_failure:
 196         nlmsg_cancel(skb, nlh);
 197         return -EMSGSIZE;
 198 }
 199
 200 void rtm_phonet_notify(int event, struct net_device *dev, u8 dst)
 201 {
 202         struct sk_buff *skb;
 203         int err = -ENOBUFS;
 204
 205         skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
 206                         nla_total_size(1) + nla_total_size(4), GFP_KERNEL);
 207         if (skb == NULL)
 208                 goto errout;
 209         err = fill_route(skb, dev, dst, 0, 0, event);
 210         if (err < 0) {
 211                 WARN_ON(err == -EMSGSIZE);
 212                 kfree_skb(skb);
 213                 goto errout;
 214         }
 215         rtnl_notify(skb, dev_net(dev), 0,
 216                           RTNLGRP_PHONET_ROUTE, NULL, GFP_KERNEL);
 217         return;
 218 errout:
 219         rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_ROUTE, err);
 220 }
 221
 222 static const struct nla_policy rtm_phonet_policy[RTA_MAX+1] = {
 223         [RTA_DST] = { .type = NLA_U8 },
 224         [RTA_OIF] = { .type = NLA_U32 },
 225 };
 226
 227 static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh)
 228 {
 229         struct net *net = sock_net(skb->sk);
 230         struct nlattr *tb[RTA_MAX+1];
 231         struct net_device *dev;
 232         struct rtmsg *rtm;
 233         int err;
 234         u8 dst;
 235
 236         if (!netlink_capable(skb, CAP_NET_ADMIN))
 237                 return -EPERM;
 238
 239         if (!netlink_capable(skb, CAP_SYS_ADMIN))
 240                 return -EPERM;
 241
 242         ASSERT_RTNL();
 243
 244         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_phonet_policy);
 245         if (err < 0)
 246                 return err;
 247
 248         rtm = nlmsg_data(nlh);
 249         if (rtm->rtm_table != RT_TABLE_MAIN || rtm->rtm_type != RTN_UNICAST)
 250                 return -EINVAL;
 251         if (tb[RTA_DST] == NULL || tb[RTA_OIF] == NULL)
 252                 return -EINVAL;
 253         dst = nla_get_u8(tb[RTA_DST]);
 254         if (dst & 3) /* Phonet addresses only have 6 high-order bits */
 255                 return -EINVAL;
 256
 257         dev = __dev_get_by_index(net, nla_get_u32(tb[RTA_OIF]));
 258         if (dev == NULL)
 259                 return -ENODEV;
 260
 261         if (nlh->nlmsg_type == RTM_NEWROUTE)
 262                 err = phonet_route_add(dev, dst);
 263         else
 264                 err = phonet_route_del(dev, dst);
 265         if (!err)
 266                 rtm_phonet_notify(nlh->nlmsg_type, dev, dst);
 267         return err;
 268 }
 269
 270 static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 271 {
 272         struct net *net = sock_net(skb->sk);
 273         u8 addr, addr_idx = 0, addr_start_idx = cb->args[0];
 274
 275         rcu_read_lock();
 276         for (addr = 0; addr < 64; addr++) {
 277                 struct net_device *dev;
 278
 279                 dev = phonet_route_get_rcu(net, addr << 2);
 280                 if (!dev)
 281                         continue;
 282
 283                 if (addr_idx++ < addr_start_idx)
 284                         continue;
 285                 if (fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).portid,
 286                                 cb->nlh->nlmsg_seq, RTM_NEWROUTE))
 287                         goto out;
 288         }
 289
 290 out:
 291         rcu_read_unlock();
 292         cb->args[0] = addr_idx;
 293         cb->args[1] = 0;
 294
 295         return skb->len;
 296 }
 297
 298 int __init phonet_netlink_register(void)
 299 {
 300         int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit,
 301                                   NULL, NULL);
 302         if (err)
 303                 return err;
 304
 305         /* Further __rtnl_register() cannot fail */
 306         __rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL, NULL);
 307         __rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit, NULL);
 308         __rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL, NULL);
 309         __rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL, NULL);
 310         __rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit, NULL);
 311         return 0;
 312 }