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