/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Routing netlink socket interface: protocol independent part.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Fixes:
* Vitaly E. Lavrov RTA_OK arithmetics was wrong.
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/capability.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/string.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/arp.h>
#include <net/route.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
DECLARE_MUTEX(rtnl_sem);
55 void rtnl_lock(void)
{
rtnl_shlock();
58 rtnl_exlock();
}
61 void rtnl_unlock(void)
{
63 rtnl_exunlock();
rtnl_shunlock();
}
67 int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
{
memset(tb, 0, sizeof(struct rtattr*)*maxattr);
71 while (RTA_OK(rta, len)) {
unsigned flavor = rta->rta_type;
73 if (flavor && flavor <= maxattr)
tb[flavor-1] = rta;
rta = RTA_NEXT(rta, len);
}
77 return 0;
}
#ifdef CONFIG_RTNETLINK
struct sock *rtnl;
struct rtnetlink_link * rtnetlink_links[NPROTO];
#define _S 1 /* superuser privileges required */
#define _X 2 /* exclusive access to tables required */
#define _G 4 /* GET request */
static const int rtm_min[(RTM_MAX+1-RTM_BASE)/4] =
{
NLMSG_LENGTH(sizeof(struct ifinfomsg)),
NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
NLMSG_LENGTH(sizeof(struct rtmsg)),
NLMSG_LENGTH(sizeof(struct ndmsg)),
NLMSG_LENGTH(sizeof(struct rtmsg)),
NLMSG_LENGTH(sizeof(struct tcmsg)),
NLMSG_LENGTH(sizeof(struct tcmsg)),
NLMSG_LENGTH(sizeof(struct tcmsg))
};
static const int rta_max[(RTM_MAX+1-RTM_BASE)/4] =
{
IFLA_MAX,
IFA_MAX,
RTA_MAX,
NDA_MAX,
RTA_MAX,
TCA_MAX,
TCA_MAX,
TCA_MAX
};
void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
{
struct rtattr *rta;
int size = RTA_LENGTH(attrlen);
rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
rta->rta_type = attrtype;
rta->rta_len = size;
memcpy(RTA_DATA(rta), data, attrlen);
}
int rtnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
{
int err = 0;
NETLINK_CB(skb).dst_groups = group;
if (echo)
atomic_inc(&skb->users);
netlink_broadcast(rtnl, skb, pid, group, GFP_KERNEL);
if (echo)
err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
return err;
}
int rtnetlink_put_metrics(struct sk_buff *skb, unsigned *metrics)
{
struct rtattr *mx = (struct rtattr*)skb->tail;
int i;
RTA_PUT(skb, RTA_METRICS, 0, NULL);
for (i=0; i<RTAX_MAX; i++) {
if (metrics[i])
RTA_PUT(skb, i+1, sizeof(unsigned), metrics+i);
}
mx->rta_len = skb->tail - (u8*)mx;
if (mx->rta_len == RTA_LENGTH(0))
skb_trim(skb, (u8*)mx - skb->data);
return 0;
rtattr_failure:
skb_trim(skb, (u8*)mx - skb->data);
return -1;
}
static int rtnetlink_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
int type, u32 pid, u32 seq, u32 change)
{
struct ifinfomsg *r;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
nlh = NLMSG_PUT(skb, pid, seq, type, sizeof(*r));
if (pid) nlh->nlmsg_flags |= NLM_F_MULTI;
r = NLMSG_DATA(nlh);
r->ifi_family = AF_UNSPEC;
r->ifi_type = dev->type;
r->ifi_index = dev->ifindex;
r->ifi_flags = dev->flags;
r->ifi_change = change;
if (!netif_running(dev) || !netif_carrier_ok(dev))
r->ifi_flags &= ~IFF_RUNNING;
else
r->ifi_flags |= IFF_RUNNING;
RTA_PUT(skb, IFLA_IFNAME, strlen(dev->name)+1, dev->name);
if (dev->addr_len) {
RTA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr);
RTA_PUT(skb, IFLA_BROADCAST, dev->addr_len, dev->broadcast);
}
if (1) {
unsigned mtu = dev->mtu;
RTA_PUT(skb, IFLA_MTU, sizeof(mtu), &mtu);
}
if (dev->ifindex != dev->iflink)
RTA_PUT(skb, IFLA_LINK, sizeof(int), &dev->iflink);
if (dev->qdisc_sleeping)
RTA_PUT(skb, IFLA_QDISC,
strlen(dev->qdisc_sleeping->ops->id) + 1,
dev->qdisc_sleeping->ops->id);
if (dev->master)
RTA_PUT(skb, IFLA_MASTER, sizeof(int), &dev->master->ifindex);
if (dev->get_stats) {
struct net_device_stats *stats = dev->get_stats(dev);
if (stats)
RTA_PUT(skb, IFLA_STATS, sizeof(*stats), stats);
}
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
int rtnetlink_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
{
int idx;
int s_idx = cb->args[0];
struct net_device *dev;
read_lock(&dev_base_lock);
for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
if (idx < s_idx)
continue;
if (rtnetlink_fill_ifinfo(skb, dev, RTM_NEWLINK, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, 0) <= 0)
break;
}
read_unlock(&dev_base_lock);
cb->args[0] = idx;
return skb->len;
}
int rtnetlink_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
{
int idx;
int s_idx = cb->family;
if (s_idx == 0)
s_idx = 1;
for (idx=1; idx<NPROTO; idx++) {
int type = cb->nlh->nlmsg_type-RTM_BASE;
if (idx < s_idx || idx == PF_PACKET)
continue;
if (rtnetlink_links[idx] == NULL ||
rtnetlink_links[idx][type].dumpit == NULL)
continue;
if (idx > s_idx)
memset(&cb->args[0], 0, sizeof(cb->args));
if (rtnetlink_links[idx][type].dumpit(skb, cb))
break;
}
cb->family = idx;
return skb->len;
}
void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
{
struct sk_buff *skb;
int size = NLMSG_GOODSIZE;
skb = alloc_skb(size, GFP_KERNEL);
if (!skb)
return;
if (rtnetlink_fill_ifinfo(skb, dev, type, 0, 0, change) < 0) {
kfree_skb(skb);
return;
}
NETLINK_CB(skb).dst_groups = RTMGRP_LINK;
netlink_broadcast(rtnl, skb, 0, RTMGRP_LINK, GFP_KERNEL);
}
static int rtnetlink_done(struct netlink_callback *cb)
{
return 0;
}
/* Process one rtnetlink message. */
extern __inline__ int
rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
{
struct rtnetlink_link *link;
struct rtnetlink_link *link_tab;
struct rtattr *rta[RTATTR_MAX];
int exclusive = 0;
int sz_idx, kind;
int min_len;
int family;
int type;
int err;
/* Only requests are handled by kernel now */
if (!(nlh->nlmsg_flags&NLM_F_REQUEST))
return 0;
type = nlh->nlmsg_type;
/* A control message: ignore them */
if (type < RTM_BASE)
return 0;
/* Unknown message: reply with EINVAL */
if (type > RTM_MAX)
goto err_inval;
type -= RTM_BASE;
/* All the messages must have at least 1 byte length */
if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
return 0;
family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
if (family > NPROTO) {
*errp = -EAFNOSUPPORT;
return -1;
}
link_tab = rtnetlink_links[family];
if (link_tab == NULL)
link_tab = rtnetlink_links[PF_UNSPEC];
link = &link_tab[type];
sz_idx = type>>2;
kind = type&3;
if (kind != 2 && !cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) {
*errp = -EPERM;
return -1;
}
if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
u32 rlen;
if (link->dumpit == NULL)
link = &(rtnetlink_links[PF_UNSPEC][type]);
if (link->dumpit == NULL)
goto err_inval;
if ((*errp = netlink_dump_start(rtnl, skb, nlh,
link->dumpit,
rtnetlink_done)) != 0) {
return -1;
}
rlen = NLMSG_ALIGN(nlh->nlmsg_len);
if (rlen > skb->len)
rlen = skb->len;
skb_pull(skb, rlen);
return -1;
}
if (kind != 2) {
if (rtnl_exlock_nowait()) {
*errp = 0;
return -1;
}
exclusive = 1;
}
memset(&rta, 0, sizeof(rta));
min_len = rtm_min[sz_idx];
if (nlh->nlmsg_len < min_len)
goto err_inval;
if (nlh->nlmsg_len > min_len) {
int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
struct rtattr *attr = (void*)nlh + NLMSG_ALIGN(min_len);
while (RTA_OK(attr, attrlen)) {
unsigned flavor = attr->rta_type;
if (flavor) {
if (flavor > rta_max[sz_idx])
goto err_inval;
rta[flavor-1] = attr;
}
attr = RTA_NEXT(attr, attrlen);
}
}
if (link->doit == NULL)
link = &(rtnetlink_links[PF_UNSPEC][type]);
if (link->doit == NULL)
goto err_inval;
err = link->doit(skb, nlh, (void *)&rta);
if (exclusive)
rtnl_exunlock();
*errp = err;
return err;
err_inval:
if (exclusive)
rtnl_exunlock();
*errp = -EINVAL;
return -1;
}
/*
* Process one packet of messages.
* Malformed skbs with wrong lengths of messages are discarded silently.
*/
extern __inline__ int rtnetlink_rcv_skb(struct sk_buff *skb)
{
int err;
struct nlmsghdr * nlh;
while (skb->len >= NLMSG_SPACE(0)) {
u32 rlen;
nlh = (struct nlmsghdr *)skb->data;
if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
return 0;
rlen = NLMSG_ALIGN(nlh->nlmsg_len);
if (rlen > skb->len)
rlen = skb->len;
if (rtnetlink_rcv_msg(skb, nlh, &err)) {
/* Not error, but we must interrupt processing here:
* Note, that in this case we do not pull message
* from skb, it will be processed later.
*/
if (err == 0)
return -1;
netlink_ack(skb, nlh, err);
} else if (nlh->nlmsg_flags&NLM_F_ACK)
netlink_ack(skb, nlh, 0);
skb_pull(skb, rlen);
}
return 0;
}
/*
* rtnetlink input queue processing routine:
* - try to acquire shared lock. If it is failed, defer processing.
* - feed skbs to rtnetlink_rcv_skb, until it refuse a message,
* that will occur, when a dump started and/or acquisition of
* exclusive lock failed.
*/
static void rtnetlink_rcv(struct sock *sk, int len)
{
do {
struct sk_buff *skb;
if (rtnl_shlock_nowait())
return;
while ((skb = skb_dequeue(&sk->receive_queue)) != NULL) {
if (rtnetlink_rcv_skb(skb)) {
if (skb->len)
skb_queue_head(&sk->receive_queue, skb);
else
kfree_skb(skb);
break;
}
kfree_skb(skb);
}
up(&rtnl_sem);
} while (rtnl && rtnl->receive_queue.qlen);
}
static struct rtnetlink_link link_rtnetlink_table[RTM_MAX-RTM_BASE+1] =
{
{ NULL, NULL, },
{ NULL, NULL, },
{ NULL, rtnetlink_dump_ifinfo, },
{ NULL, NULL, },
{ NULL, NULL, },
{ NULL, NULL, },
{ NULL, rtnetlink_dump_all, },
{ NULL, NULL, },
{ NULL, NULL, },
{ NULL, NULL, },
{ NULL, rtnetlink_dump_all, },
{ NULL, NULL, },
{ neigh_add, NULL, },
{ neigh_delete, NULL, },
{ NULL, neigh_dump_info, },
{ NULL, NULL, },
{ NULL, NULL, },
{ NULL, NULL, },
{ NULL, NULL, },
{ NULL, NULL, },
};
static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = ptr;
switch (event) {
case NETDEV_UNREGISTER:
rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
break;
case NETDEV_REGISTER:
rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
break;
case NETDEV_UP:
case NETDEV_DOWN:
rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
break;
case NETDEV_CHANGE:
case NETDEV_GOING_DOWN:
break;
default:
rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
break;
}
return NOTIFY_DONE;
}
struct notifier_block rtnetlink_dev_notifier = {
rtnetlink_event,
NULL,
0
};
void __init rtnetlink_init(void)
{
#ifdef RTNL_DEBUG
printk("Initializing RT netlink socket\n");
#endif
rtnl = netlink_kernel_create(NETLINK_ROUTE, rtnetlink_rcv);
if (rtnl == NULL)
panic("rtnetlink_init: cannot initialize rtnetlink\n");
register_netdevice_notifier(&rtnetlink_dev_notifier);
rtnetlink_links[PF_UNSPEC] = link_rtnetlink_table;
rtnetlink_links[PF_PACKET] = link_rtnetlink_table;
}
#endif