linux/net/phonet/pn_netlink.c
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   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
  35static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
  36                     u32 portid, u32 seq, int event);
  37
  38void 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;
  56errout:
  57        rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
  58}
  59
  60static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
  61        [IFA_LOCAL] = { .type = NLA_U8 },
  62};
  63
  64static 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_NET_ADMIN))
  74                return -EPERM;
  75
  76        if (!capable(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
 106static 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
 126nla_put_failure:
 127        nlmsg_cancel(skb, nlh);
 128        return -EMSGSIZE;
 129}
 130
 131static 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
 160out:
 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
 170static 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
 195nla_put_failure:
 196        nlmsg_cancel(skb, nlh);
 197        return -EMSGSIZE;
 198}
 199
 200void 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;
 218errout:
 219        rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_ROUTE, err);
 220}
 221
 222static const struct nla_policy rtm_phonet_policy[RTA_MAX+1] = {
 223        [RTA_DST] = { .type = NLA_U8 },
 224        [RTA_OIF] = { .type = NLA_U32 },
 225};
 226
 227static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
 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 (!capable(CAP_NET_ADMIN))
 237                return -EPERM;
 238
 239        if (!capable(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
 270static 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
 290out:
 291        rcu_read_unlock();
 292        cb->args[0] = addr_idx;
 293        cb->args[1] = 0;
 294
 295        return skb->len;
 296}
 297
 298int __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}
 313
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