kernel-ark/net/core/rtnetlink.c
Jamal Hadi Salim 9ed19f339e [NETLINK]: Set correct pid for ioctl originating netlink events
This patch ensures that netlink events created as a result of programns
using ioctls (such as ifconfig, route etc) contains the correct PID of
those events.
 
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:55:51 -07:00

728 lines
17 KiB
C

/*
* 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/module.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/kernel.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 <linux/security.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/udp.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
DECLARE_MUTEX(rtnl_sem);
void rtnl_lock(void)
{
rtnl_shlock();
}
int rtnl_lock_interruptible(void)
{
return down_interruptible(&rtnl_sem);
}
void rtnl_unlock(void)
{
rtnl_shunlock();
netdev_run_todo();
}
int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
{
memset(tb, 0, sizeof(struct rtattr*)*maxattr);
while (RTA_OK(rta, len)) {
unsigned flavor = rta->rta_type;
if (flavor && flavor <= maxattr)
tb[flavor-1] = rta;
rta = RTA_NEXT(rta, len);
}
return 0;
}
struct sock *rtnl;
struct rtnetlink_link * rtnetlink_links[NPROTO];
static const int rtm_min[RTM_NR_FAMILIES] =
{
[RTM_FAM(RTM_NEWLINK)] = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
[RTM_FAM(RTM_NEWADDR)] = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
[RTM_FAM(RTM_NEWROUTE)] = NLMSG_LENGTH(sizeof(struct rtmsg)),
[RTM_FAM(RTM_NEWNEIGH)] = NLMSG_LENGTH(sizeof(struct ndmsg)),
[RTM_FAM(RTM_NEWRULE)] = NLMSG_LENGTH(sizeof(struct rtmsg)),
[RTM_FAM(RTM_NEWQDISC)] = NLMSG_LENGTH(sizeof(struct tcmsg)),
[RTM_FAM(RTM_NEWTCLASS)] = NLMSG_LENGTH(sizeof(struct tcmsg)),
[RTM_FAM(RTM_NEWTFILTER)] = NLMSG_LENGTH(sizeof(struct tcmsg)),
[RTM_FAM(RTM_NEWACTION)] = NLMSG_LENGTH(sizeof(struct tcamsg)),
[RTM_FAM(RTM_NEWPREFIX)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
[RTM_FAM(RTM_GETMULTICAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
[RTM_FAM(RTM_GETANYCAST)] = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
[RTM_FAM(RTM_NEWNEIGHTBL)] = NLMSG_LENGTH(sizeof(struct ndtmsg)),
};
static const int rta_max[RTM_NR_FAMILIES] =
{
[RTM_FAM(RTM_NEWLINK)] = IFLA_MAX,
[RTM_FAM(RTM_NEWADDR)] = IFA_MAX,
[RTM_FAM(RTM_NEWROUTE)] = RTA_MAX,
[RTM_FAM(RTM_NEWNEIGH)] = NDA_MAX,
[RTM_FAM(RTM_NEWRULE)] = RTA_MAX,
[RTM_FAM(RTM_NEWQDISC)] = TCA_MAX,
[RTM_FAM(RTM_NEWTCLASS)] = TCA_MAX,
[RTM_FAM(RTM_NEWTFILTER)] = TCA_MAX,
[RTM_FAM(RTM_NEWACTION)] = TCAA_MAX,
[RTM_FAM(RTM_NEWNEIGHTBL)] = NDTA_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);
}
size_t rtattr_strlcpy(char *dest, const struct rtattr *rta, size_t size)
{
size_t ret = RTA_PAYLOAD(rta);
char *src = RTA_DATA(rta);
if (ret > 0 && src[ret - 1] == '\0')
ret--;
if (size > 0) {
size_t len = (ret >= size) ? size - 1 : ret;
memset(dest, 0, size);
memcpy(dest, src, len);
}
return ret;
}
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, u32 *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(u32), 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,
unsigned int flags)
{
struct ifinfomsg *r;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
nlh = NLMSG_NEW(skb, pid, seq, type, sizeof(*r), flags);
r = NLMSG_DATA(nlh);
r->ifi_family = AF_UNSPEC;
r->ifi_type = dev->type;
r->ifi_index = dev->ifindex;
r->ifi_flags = dev_get_flags(dev);
r->ifi_change = change;
RTA_PUT(skb, IFLA_IFNAME, strlen(dev->name)+1, dev->name);
if (1) {
u32 txqlen = dev->tx_queue_len;
RTA_PUT(skb, IFLA_TXQLEN, sizeof(txqlen), &txqlen);
}
if (1) {
u32 weight = dev->weight;
RTA_PUT(skb, IFLA_WEIGHT, sizeof(weight), &weight);
}
if (1) {
struct rtnl_link_ifmap map = {
.mem_start = dev->mem_start,
.mem_end = dev->mem_end,
.base_addr = dev->base_addr,
.irq = dev->irq,
.dma = dev->dma,
.port = dev->if_port,
};
RTA_PUT(skb, IFLA_MAP, sizeof(map), &map);
}
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) {
u32 mtu = dev->mtu;
RTA_PUT(skb, IFLA_MTU, sizeof(mtu), &mtu);
}
if (dev->ifindex != dev->iflink) {
u32 iflink = dev->iflink;
RTA_PUT(skb, IFLA_LINK, sizeof(iflink), &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) {
u32 master = dev->master->ifindex;
RTA_PUT(skb, IFLA_MASTER, sizeof(master), &master);
}
if (dev->get_stats) {
unsigned long *stats = (unsigned long*)dev->get_stats(dev);
if (stats) {
struct rtattr *a;
__u32 *s;
int i;
int n = sizeof(struct rtnl_link_stats)/4;
a = __RTA_PUT(skb, IFLA_STATS, n*4);
s = RTA_DATA(a);
for (i=0; i<n; i++)
s[i] = stats[i];
}
}
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
static 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,
NLM_F_MULTI) <= 0)
break;
}
read_unlock(&dev_base_lock);
cb->args[0] = idx;
return skb->len;
}
static int do_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
struct ifinfomsg *ifm = NLMSG_DATA(nlh);
struct rtattr **ida = arg;
struct net_device *dev;
int err, send_addr_notify = 0;
if (ifm->ifi_index >= 0)
dev = dev_get_by_index(ifm->ifi_index);
else if (ida[IFLA_IFNAME - 1]) {
char ifname[IFNAMSIZ];
if (rtattr_strlcpy(ifname, ida[IFLA_IFNAME - 1],
IFNAMSIZ) >= IFNAMSIZ)
return -EINVAL;
dev = dev_get_by_name(ifname);
} else
return -EINVAL;
if (!dev)
return -ENODEV;
err = -EINVAL;
if (ifm->ifi_flags)
dev_change_flags(dev, ifm->ifi_flags);
if (ida[IFLA_MAP - 1]) {
struct rtnl_link_ifmap *u_map;
struct ifmap k_map;
if (!dev->set_config) {
err = -EOPNOTSUPP;
goto out;
}
if (!netif_device_present(dev)) {
err = -ENODEV;
goto out;
}
if (ida[IFLA_MAP - 1]->rta_len != RTA_LENGTH(sizeof(*u_map)))
goto out;
u_map = RTA_DATA(ida[IFLA_MAP - 1]);
k_map.mem_start = (unsigned long) u_map->mem_start;
k_map.mem_end = (unsigned long) u_map->mem_end;
k_map.base_addr = (unsigned short) u_map->base_addr;
k_map.irq = (unsigned char) u_map->irq;
k_map.dma = (unsigned char) u_map->dma;
k_map.port = (unsigned char) u_map->port;
err = dev->set_config(dev, &k_map);
if (err)
goto out;
}
if (ida[IFLA_ADDRESS - 1]) {
if (!dev->set_mac_address) {
err = -EOPNOTSUPP;
goto out;
}
if (!netif_device_present(dev)) {
err = -ENODEV;
goto out;
}
if (ida[IFLA_ADDRESS - 1]->rta_len != RTA_LENGTH(dev->addr_len))
goto out;
err = dev->set_mac_address(dev, RTA_DATA(ida[IFLA_ADDRESS - 1]));
if (err)
goto out;
send_addr_notify = 1;
}
if (ida[IFLA_BROADCAST - 1]) {
if (ida[IFLA_BROADCAST - 1]->rta_len != RTA_LENGTH(dev->addr_len))
goto out;
memcpy(dev->broadcast, RTA_DATA(ida[IFLA_BROADCAST - 1]),
dev->addr_len);
send_addr_notify = 1;
}
if (ida[IFLA_MTU - 1]) {
if (ida[IFLA_MTU - 1]->rta_len != RTA_LENGTH(sizeof(u32)))
goto out;
err = dev_set_mtu(dev, *((u32 *) RTA_DATA(ida[IFLA_MTU - 1])));
if (err)
goto out;
}
if (ida[IFLA_TXQLEN - 1]) {
if (ida[IFLA_TXQLEN - 1]->rta_len != RTA_LENGTH(sizeof(u32)))
goto out;
dev->tx_queue_len = *((u32 *) RTA_DATA(ida[IFLA_TXQLEN - 1]));
}
if (ida[IFLA_WEIGHT - 1]) {
if (ida[IFLA_WEIGHT - 1]->rta_len != RTA_LENGTH(sizeof(u32)))
goto out;
dev->weight = *((u32 *) RTA_DATA(ida[IFLA_WEIGHT - 1]));
}
if (ifm->ifi_index >= 0 && ida[IFLA_IFNAME - 1]) {
char ifname[IFNAMSIZ];
if (rtattr_strlcpy(ifname, ida[IFLA_IFNAME - 1],
IFNAMSIZ) >= IFNAMSIZ)
goto out;
err = dev_change_name(dev, ifname);
if (err)
goto out;
}
err = 0;
out:
if (send_addr_notify)
call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
dev_put(dev);
return err;
}
static 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_SPACE(sizeof(struct ifinfomsg) +
sizeof(struct rtnl_link_ifmap) +
sizeof(struct rtnl_link_stats) + 128);
skb = alloc_skb(size, GFP_KERNEL);
if (!skb)
return;
if (rtnetlink_fill_ifinfo(skb, dev, type, current->pid, 0, change, 0) < 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;
}
/* Protected by RTNL sempahore. */
static struct rtattr **rta_buf;
static int rtattr_max;
/* Process one rtnetlink message. */
static __inline__ int
rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
{
struct rtnetlink_link *link;
struct rtnetlink_link *link_tab;
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 && security_netlink_recv(skb)) {
*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;
}
memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
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_buf[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_buf[0]);
*errp = err;
return err;
err_inval:
*errp = -EINVAL;
return -1;
}
/*
* Process one packet of messages.
* Malformed skbs with wrong lengths of messages are discarded silently.
*/
static 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:
* - process as much as there was in the queue upon entry.
* - feed skbs to rtnetlink_rcv_skb, until it refuse a message,
* that will occur, when a dump started.
*/
static void rtnetlink_rcv(struct sock *sk, int len)
{
unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
do {
struct sk_buff *skb;
rtnl_lock();
if (qlen > skb_queue_len(&sk->sk_receive_queue))
qlen = skb_queue_len(&sk->sk_receive_queue);
for (; qlen; qlen--) {
skb = skb_dequeue(&sk->sk_receive_queue);
if (rtnetlink_rcv_skb(skb)) {
if (skb->len)
skb_queue_head(&sk->sk_receive_queue,
skb);
else {
kfree_skb(skb);
qlen--;
}
break;
}
kfree_skb(skb);
}
up(&rtnl_sem);
netdev_run_todo();
} while (qlen);
}
static struct rtnetlink_link link_rtnetlink_table[RTM_NR_MSGTYPES] =
{
[RTM_GETLINK - RTM_BASE] = { .dumpit = rtnetlink_dump_ifinfo },
[RTM_SETLINK - RTM_BASE] = { .doit = do_setlink },
[RTM_GETADDR - RTM_BASE] = { .dumpit = rtnetlink_dump_all },
[RTM_GETROUTE - RTM_BASE] = { .dumpit = rtnetlink_dump_all },
[RTM_NEWNEIGH - RTM_BASE] = { .doit = neigh_add },
[RTM_DELNEIGH - RTM_BASE] = { .doit = neigh_delete },
[RTM_GETNEIGH - RTM_BASE] = { .dumpit = neigh_dump_info },
[RTM_GETRULE - RTM_BASE] = { .dumpit = rtnetlink_dump_all },
[RTM_GETNEIGHTBL - RTM_BASE] = { .dumpit = neightbl_dump_info },
[RTM_SETNEIGHTBL - RTM_BASE] = { .doit = neightbl_set },
};
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;
}
static struct notifier_block rtnetlink_dev_notifier = {
.notifier_call = rtnetlink_event,
};
void __init rtnetlink_init(void)
{
int i;
rtattr_max = 0;
for (i = 0; i < ARRAY_SIZE(rta_max); i++)
if (rta_max[i] > rtattr_max)
rtattr_max = rta_max[i];
rta_buf = kmalloc(rtattr_max * sizeof(struct rtattr *), GFP_KERNEL);
if (!rta_buf)
panic("rtnetlink_init: cannot allocate rta_buf\n");
rtnl = netlink_kernel_create(NETLINK_ROUTE, rtnetlink_rcv);
if (rtnl == NULL)
panic("rtnetlink_init: cannot initialize rtnetlink\n");
netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
register_netdevice_notifier(&rtnetlink_dev_notifier);
rtnetlink_links[PF_UNSPEC] = link_rtnetlink_table;
rtnetlink_links[PF_PACKET] = link_rtnetlink_table;
}
EXPORT_SYMBOL(__rta_fill);
EXPORT_SYMBOL(rtattr_strlcpy);
EXPORT_SYMBOL(rtattr_parse);
EXPORT_SYMBOL(rtnetlink_links);
EXPORT_SYMBOL(rtnetlink_put_metrics);
EXPORT_SYMBOL(rtnl);
EXPORT_SYMBOL(rtnl_lock);
EXPORT_SYMBOL(rtnl_lock_interruptible);
EXPORT_SYMBOL(rtnl_sem);
EXPORT_SYMBOL(rtnl_unlock);