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fib_frontend.c
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fib_frontend.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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.
*
* IPv4 Forwarding Information Base: FIB frontend.
*
* Authors: Alexey Kuznetsov, <[email protected]>
*/
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <linux/capability.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/if_addr.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/cache.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/route.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <net/arp.h>
#include <net/ip_fib.h>
#include <net/nexthop.h>
#include <net/rtnetlink.h>
#include <net/xfrm.h>
#include <net/l3mdev.h>
#include <net/lwtunnel.h>
#include <trace/events/fib.h>
#ifndef CONFIG_IP_MULTIPLE_TABLES
static int __net_init fib4_rules_init(struct net *net)
{
struct fib_table *local_table, *main_table;
main_table = fib_trie_table(RT_TABLE_MAIN, NULL);
if (!main_table)
return -ENOMEM;
local_table = fib_trie_table(RT_TABLE_LOCAL, main_table);
if (!local_table)
goto fail;
hlist_add_head_rcu(&local_table->tb_hlist,
&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
hlist_add_head_rcu(&main_table->tb_hlist,
&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
return 0;
fail:
fib_free_table(main_table);
return -ENOMEM;
}
#else
struct fib_table *fib_new_table(struct net *net, u32 id)
{
struct fib_table *tb, *alias = NULL;
unsigned int h;
if (id == 0)
id = RT_TABLE_MAIN;
tb = fib_get_table(net, id);
if (tb)
return tb;
if (id == RT_TABLE_LOCAL && !net->ipv4.fib_has_custom_rules)
alias = fib_new_table(net, RT_TABLE_MAIN);
tb = fib_trie_table(id, alias);
if (!tb)
return NULL;
switch (id) {
case RT_TABLE_MAIN:
rcu_assign_pointer(net->ipv4.fib_main, tb);
break;
case RT_TABLE_DEFAULT:
rcu_assign_pointer(net->ipv4.fib_default, tb);
break;
default:
break;
}
h = id & (FIB_TABLE_HASHSZ - 1);
hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
return tb;
}
EXPORT_SYMBOL_GPL(fib_new_table);
/* caller must hold either rtnl or rcu read lock */
struct fib_table *fib_get_table(struct net *net, u32 id)
{
struct fib_table *tb;
struct hlist_head *head;
unsigned int h;
if (id == 0)
id = RT_TABLE_MAIN;
h = id & (FIB_TABLE_HASHSZ - 1);
head = &net->ipv4.fib_table_hash[h];
hlist_for_each_entry_rcu(tb, head, tb_hlist,
lockdep_rtnl_is_held()) {
if (tb->tb_id == id)
return tb;
}
return NULL;
}
#endif /* CONFIG_IP_MULTIPLE_TABLES */
static void fib_replace_table(struct net *net, struct fib_table *old,
struct fib_table *new)
{
#ifdef CONFIG_IP_MULTIPLE_TABLES
switch (new->tb_id) {
case RT_TABLE_MAIN:
rcu_assign_pointer(net->ipv4.fib_main, new);
break;
case RT_TABLE_DEFAULT:
rcu_assign_pointer(net->ipv4.fib_default, new);
break;
default:
break;
}
#endif
/* replace the old table in the hlist */
hlist_replace_rcu(&old->tb_hlist, &new->tb_hlist);
}
int fib_unmerge(struct net *net)
{
struct fib_table *old, *new, *main_table;
/* attempt to fetch local table if it has been allocated */
old = fib_get_table(net, RT_TABLE_LOCAL);
if (!old)
return 0;
new = fib_trie_unmerge(old);
if (!new)
return -ENOMEM;
/* table is already unmerged */
if (new == old)
return 0;
/* replace merged table with clean table */
fib_replace_table(net, old, new);
fib_free_table(old);
/* attempt to fetch main table if it has been allocated */
main_table = fib_get_table(net, RT_TABLE_MAIN);
if (!main_table)
return 0;
/* flush local entries from main table */
fib_table_flush_external(main_table);
return 0;
}
void fib_flush(struct net *net)
{
int flushed = 0;
unsigned int h;
for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
struct hlist_head *head = &net->ipv4.fib_table_hash[h];
struct hlist_node *tmp;
struct fib_table *tb;
hlist_for_each_entry_safe(tb, tmp, head, tb_hlist)
flushed += fib_table_flush(net, tb, false);
}
if (flushed)
rt_cache_flush(net);
}
/*
* Find address type as if only "dev" was present in the system. If
* on_dev is NULL then all interfaces are taken into consideration.
*/
static inline unsigned int __inet_dev_addr_type(struct net *net,
const struct net_device *dev,
__be32 addr, u32 tb_id)
{
struct flowi4 fl4 = { .daddr = addr };
struct fib_result res;
unsigned int ret = RTN_BROADCAST;
struct fib_table *table;
if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
return RTN_BROADCAST;
if (ipv4_is_multicast(addr))
return RTN_MULTICAST;
rcu_read_lock();
table = fib_get_table(net, tb_id);
if (table) {
ret = RTN_UNICAST;
if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
struct fib_nh_common *nhc = fib_info_nhc(res.fi, 0);
if (!dev || dev == nhc->nhc_dev)
ret = res.type;
}
}
rcu_read_unlock();
return ret;
}
unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id)
{
return __inet_dev_addr_type(net, NULL, addr, tb_id);
}
EXPORT_SYMBOL(inet_addr_type_table);
unsigned int inet_addr_type(struct net *net, __be32 addr)
{
return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
}
EXPORT_SYMBOL(inet_addr_type);
unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
__be32 addr)
{
u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
return __inet_dev_addr_type(net, dev, addr, rt_table);
}
EXPORT_SYMBOL(inet_dev_addr_type);
/* inet_addr_type with dev == NULL but using the table from a dev
* if one is associated
*/
unsigned int inet_addr_type_dev_table(struct net *net,
const struct net_device *dev,
__be32 addr)
{
u32 rt_table = l3mdev_fib_table(dev) ? : RT_TABLE_LOCAL;
return __inet_dev_addr_type(net, NULL, addr, rt_table);
}
EXPORT_SYMBOL(inet_addr_type_dev_table);
__be32 fib_compute_spec_dst(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
struct in_device *in_dev;
struct fib_result res;
struct rtable *rt;
struct net *net;
int scope;
rt = skb_rtable(skb);
if ((rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | RTCF_LOCAL)) ==
RTCF_LOCAL)
return ip_hdr(skb)->daddr;
in_dev = __in_dev_get_rcu(dev);
net = dev_net(dev);
scope = RT_SCOPE_UNIVERSE;
if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
struct flowi4 fl4 = {
.flowi4_iif = LOOPBACK_IFINDEX,
.flowi4_oif = l3mdev_master_ifindex_rcu(dev),
.daddr = ip_hdr(skb)->saddr,
.flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
.flowi4_scope = scope,
.flowi4_mark = vmark ? skb->mark : 0,
};
if (!fib_lookup(net, &fl4, &res, 0))
return fib_result_prefsrc(net, &res);
} else {
scope = RT_SCOPE_LINK;
}
return inet_select_addr(dev, ip_hdr(skb)->saddr, scope);
}
bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev)
{
bool dev_match = false;
#ifdef CONFIG_IP_ROUTE_MULTIPATH
if (unlikely(fi->nh)) {
dev_match = nexthop_uses_dev(fi->nh, dev);
} else {
int ret;
for (ret = 0; ret < fib_info_num_path(fi); ret++) {
const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
if (nhc_l3mdev_matches_dev(nhc, dev)) {
dev_match = true;
break;
}
}
}
#else
if (fib_info_nhc(fi, 0)->nhc_dev == dev)
dev_match = true;
#endif
return dev_match;
}
EXPORT_SYMBOL_GPL(fib_info_nh_uses_dev);
/* Given (packet source, input interface) and optional (dst, oif, tos):
* - (main) check, that source is valid i.e. not broadcast or our local
* address.
* - figure out what "logical" interface this packet arrived
* and calculate "specific destination" address.
* - check, that packet arrived from expected physical interface.
* called with rcu_read_lock()
*/
static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
u8 tos, int oif, struct net_device *dev,
int rpf, struct in_device *idev, u32 *itag)
{
struct net *net = dev_net(dev);
struct flow_keys flkeys;
int ret, no_addr;
struct fib_result res;
struct flowi4 fl4;
bool dev_match;
fl4.flowi4_oif = 0;
fl4.flowi4_iif = l3mdev_master_ifindex_rcu(dev);
if (!fl4.flowi4_iif)
fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
fl4.daddr = src;
fl4.saddr = dst;
fl4.flowi4_tos = tos;
fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
fl4.flowi4_tun_key.tun_id = 0;
fl4.flowi4_flags = 0;
fl4.flowi4_uid = sock_net_uid(net, NULL);
no_addr = idev->ifa_list == NULL;
fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
if (!fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys)) {
fl4.flowi4_proto = 0;
fl4.fl4_sport = 0;
fl4.fl4_dport = 0;
}
if (fib_lookup(net, &fl4, &res, 0))
goto last_resort;
if (res.type != RTN_UNICAST &&
(res.type != RTN_LOCAL || !IN_DEV_ACCEPT_LOCAL(idev)))
goto e_inval;
fib_combine_itag(itag, &res);
dev_match = fib_info_nh_uses_dev(res.fi, dev);
/* This is not common, loopback packets retain skb_dst so normally they
* would not even hit this slow path.
*/
dev_match = dev_match || (res.type == RTN_LOCAL &&
dev == net->loopback_dev);
if (dev_match) {
ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
return ret;
}
if (no_addr)
goto last_resort;
if (rpf == 1)
goto e_rpf;
fl4.flowi4_oif = dev->ifindex;
ret = 0;
if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) {
if (res.type == RTN_UNICAST)
ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST;
}
return ret;
last_resort:
if (rpf)
goto e_rpf;
*itag = 0;
return 0;
e_inval:
return -EINVAL;
e_rpf:
return -EXDEV;
}
/* Ignore rp_filter for packets protected by IPsec. */
int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
u8 tos, int oif, struct net_device *dev,
struct in_device *idev, u32 *itag)
{
int r = secpath_exists(skb) ? 0 : IN_DEV_RPFILTER(idev);
struct net *net = dev_net(dev);
if (!r && !fib_num_tclassid_users(net) &&
(dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))) {
if (IN_DEV_ACCEPT_LOCAL(idev))
goto ok;
/* with custom local routes in place, checking local addresses
* only will be too optimistic, with custom rules, checking
* local addresses only can be too strict, e.g. due to vrf
*/
if (net->ipv4.fib_has_custom_local_routes ||
fib4_has_custom_rules(net))
goto full_check;
if (inet_lookup_ifaddr_rcu(net, src))
return -EINVAL;
ok:
*itag = 0;
return 0;
}
full_check:
return __fib_validate_source(skb, src, dst, tos, oif, dev, r, idev, itag);
}
static inline __be32 sk_extract_addr(struct sockaddr *addr)
{
return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
}
static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
{
struct nlattr *nla;
nla = (struct nlattr *) ((char *) mx + len);
nla->nla_type = type;
nla->nla_len = nla_attr_size(4);
*(u32 *) nla_data(nla) = value;
return len + nla_total_size(4);
}
static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
struct fib_config *cfg)
{
__be32 addr;
int plen;
memset(cfg, 0, sizeof(*cfg));
cfg->fc_nlinfo.nl_net = net;
if (rt->rt_dst.sa_family != AF_INET)
return -EAFNOSUPPORT;
/*
* Check mask for validity:
* a) it must be contiguous.
* b) destination must have all host bits clear.
* c) if application forgot to set correct family (AF_INET),
* reject request unless it is absolutely clear i.e.
* both family and mask are zero.
*/
plen = 32;
addr = sk_extract_addr(&rt->rt_dst);
if (!(rt->rt_flags & RTF_HOST)) {
__be32 mask = sk_extract_addr(&rt->rt_genmask);
if (rt->rt_genmask.sa_family != AF_INET) {
if (mask || rt->rt_genmask.sa_family)
return -EAFNOSUPPORT;
}
if (bad_mask(mask, addr))
return -EINVAL;
plen = inet_mask_len(mask);
}
cfg->fc_dst_len = plen;
cfg->fc_dst = addr;
if (cmd != SIOCDELRT) {
cfg->fc_nlflags = NLM_F_CREATE;
cfg->fc_protocol = RTPROT_BOOT;
}
if (rt->rt_metric)
cfg->fc_priority = rt->rt_metric - 1;
if (rt->rt_flags & RTF_REJECT) {
cfg->fc_scope = RT_SCOPE_HOST;
cfg->fc_type = RTN_UNREACHABLE;
return 0;
}
cfg->fc_scope = RT_SCOPE_NOWHERE;
cfg->fc_type = RTN_UNICAST;
if (rt->rt_dev) {
char *colon;
struct net_device *dev;
char devname[IFNAMSIZ];
if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
return -EFAULT;
devname[IFNAMSIZ-1] = 0;
colon = strchr(devname, ':');
if (colon)
*colon = 0;
dev = __dev_get_by_name(net, devname);
if (!dev)
return -ENODEV;
cfg->fc_oif = dev->ifindex;
cfg->fc_table = l3mdev_fib_table(dev);
if (colon) {
const struct in_ifaddr *ifa;
struct in_device *in_dev;
in_dev = __in_dev_get_rtnl(dev);
if (!in_dev)
return -ENODEV;
*colon = ':';
rcu_read_lock();
in_dev_for_each_ifa_rcu(ifa, in_dev) {
if (strcmp(ifa->ifa_label, devname) == 0)
break;
}
rcu_read_unlock();
if (!ifa)
return -ENODEV;
cfg->fc_prefsrc = ifa->ifa_local;
}
}
addr = sk_extract_addr(&rt->rt_gateway);
if (rt->rt_gateway.sa_family == AF_INET && addr) {
unsigned int addr_type;
cfg->fc_gw4 = addr;
cfg->fc_gw_family = AF_INET;
addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
if (rt->rt_flags & RTF_GATEWAY &&
addr_type == RTN_UNICAST)
cfg->fc_scope = RT_SCOPE_UNIVERSE;
}
if (cmd == SIOCDELRT)
return 0;
if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw_family)
return -EINVAL;
if (cfg->fc_scope == RT_SCOPE_NOWHERE)
cfg->fc_scope = RT_SCOPE_LINK;
if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
struct nlattr *mx;
int len = 0;
mx = kcalloc(3, nla_total_size(4), GFP_KERNEL);
if (!mx)
return -ENOMEM;
if (rt->rt_flags & RTF_MTU)
len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
if (rt->rt_flags & RTF_WINDOW)
len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
if (rt->rt_flags & RTF_IRTT)
len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
cfg->fc_mx = mx;
cfg->fc_mx_len = len;
}
return 0;
}
/*
* Handle IP routing ioctl calls.
* These are used to manipulate the routing tables
*/
int ip_rt_ioctl(struct net *net, unsigned int cmd, struct rtentry *rt)
{
struct fib_config cfg;
int err;
switch (cmd) {
case SIOCADDRT: /* Add a route */
case SIOCDELRT: /* Delete a route */
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
rtnl_lock();
err = rtentry_to_fib_config(net, cmd, rt, &cfg);
if (err == 0) {
struct fib_table *tb;
if (cmd == SIOCDELRT) {
tb = fib_get_table(net, cfg.fc_table);
if (tb)
err = fib_table_delete(net, tb, &cfg,
NULL);
else
err = -ESRCH;
} else {
tb = fib_new_table(net, cfg.fc_table);
if (tb)
err = fib_table_insert(net, tb,
&cfg, NULL);
else
err = -ENOBUFS;
}
/* allocated by rtentry_to_fib_config() */
kfree(cfg.fc_mx);
}
rtnl_unlock();
return err;
}
return -EINVAL;
}
const struct nla_policy rtm_ipv4_policy[RTA_MAX + 1] = {
[RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 },
[RTA_DST] = { .type = NLA_U32 },
[RTA_SRC] = { .type = NLA_U32 },
[RTA_IIF] = { .type = NLA_U32 },
[RTA_OIF] = { .type = NLA_U32 },
[RTA_GATEWAY] = { .type = NLA_U32 },
[RTA_PRIORITY] = { .type = NLA_U32 },
[RTA_PREFSRC] = { .type = NLA_U32 },
[RTA_METRICS] = { .type = NLA_NESTED },
[RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
[RTA_FLOW] = { .type = NLA_U32 },
[RTA_ENCAP_TYPE] = { .type = NLA_U16 },
[RTA_ENCAP] = { .type = NLA_NESTED },
[RTA_UID] = { .type = NLA_U32 },
[RTA_MARK] = { .type = NLA_U32 },
[RTA_TABLE] = { .type = NLA_U32 },
[RTA_IP_PROTO] = { .type = NLA_U8 },
[RTA_SPORT] = { .type = NLA_U16 },
[RTA_DPORT] = { .type = NLA_U16 },
[RTA_NH_ID] = { .type = NLA_U32 },
};
int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla,
struct netlink_ext_ack *extack)
{
struct rtvia *via;
int alen;
if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
NL_SET_ERR_MSG(extack, "Invalid attribute length for RTA_VIA");
return -EINVAL;
}
via = nla_data(nla);
alen = nla_len(nla) - offsetof(struct rtvia, rtvia_addr);
switch (via->rtvia_family) {
case AF_INET:
if (alen != sizeof(__be32)) {
NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_VIA");
return -EINVAL;
}
cfg->fc_gw_family = AF_INET;
cfg->fc_gw4 = *((__be32 *)via->rtvia_addr);
break;
case AF_INET6:
#ifdef CONFIG_IPV6
if (alen != sizeof(struct in6_addr)) {
NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_VIA");
return -EINVAL;
}
cfg->fc_gw_family = AF_INET6;
cfg->fc_gw6 = *((struct in6_addr *)via->rtvia_addr);
#else
NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
return -EINVAL;
#endif
break;
default:
NL_SET_ERR_MSG(extack, "Unsupported address family in RTA_VIA");
return -EINVAL;
}
return 0;
}
static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
struct nlmsghdr *nlh, struct fib_config *cfg,
struct netlink_ext_ack *extack)
{
bool has_gw = false, has_via = false;
struct nlattr *attr;
int err, remaining;
struct rtmsg *rtm;
err = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
rtm_ipv4_policy, extack);
if (err < 0)
goto errout;
memset(cfg, 0, sizeof(*cfg));
rtm = nlmsg_data(nlh);
cfg->fc_dst_len = rtm->rtm_dst_len;
cfg->fc_tos = rtm->rtm_tos;
cfg->fc_table = rtm->rtm_table;
cfg->fc_protocol = rtm->rtm_protocol;
cfg->fc_scope = rtm->rtm_scope;
cfg->fc_type = rtm->rtm_type;
cfg->fc_flags = rtm->rtm_flags;
cfg->fc_nlflags = nlh->nlmsg_flags;
cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
cfg->fc_nlinfo.nlh = nlh;
cfg->fc_nlinfo.nl_net = net;
if (cfg->fc_type > RTN_MAX) {
NL_SET_ERR_MSG(extack, "Invalid route type");
err = -EINVAL;
goto errout;
}
nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
switch (nla_type(attr)) {
case RTA_DST:
cfg->fc_dst = nla_get_be32(attr);
break;
case RTA_OIF:
cfg->fc_oif = nla_get_u32(attr);
break;
case RTA_GATEWAY:
has_gw = true;
cfg->fc_gw4 = nla_get_be32(attr);
if (cfg->fc_gw4)
cfg->fc_gw_family = AF_INET;
break;
case RTA_VIA:
has_via = true;
err = fib_gw_from_via(cfg, attr, extack);
if (err)
goto errout;
break;
case RTA_PRIORITY:
cfg->fc_priority = nla_get_u32(attr);
break;
case RTA_PREFSRC:
cfg->fc_prefsrc = nla_get_be32(attr);
break;
case RTA_METRICS:
cfg->fc_mx = nla_data(attr);
cfg->fc_mx_len = nla_len(attr);
break;
case RTA_MULTIPATH:
err = lwtunnel_valid_encap_type_attr(nla_data(attr),
nla_len(attr),
extack);
if (err < 0)
goto errout;
cfg->fc_mp = nla_data(attr);
cfg->fc_mp_len = nla_len(attr);
break;
case RTA_FLOW:
cfg->fc_flow = nla_get_u32(attr);
break;
case RTA_TABLE:
cfg->fc_table = nla_get_u32(attr);
break;
case RTA_ENCAP:
cfg->fc_encap = attr;
break;
case RTA_ENCAP_TYPE:
cfg->fc_encap_type = nla_get_u16(attr);
err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
extack);
if (err < 0)
goto errout;
break;
case RTA_NH_ID:
cfg->fc_nh_id = nla_get_u32(attr);
break;
}
}
if (cfg->fc_nh_id) {
if (cfg->fc_oif || cfg->fc_gw_family ||
cfg->fc_encap || cfg->fc_mp) {
NL_SET_ERR_MSG(extack,
"Nexthop specification and nexthop id are mutually exclusive");
return -EINVAL;
}
}
if (has_gw && has_via) {
NL_SET_ERR_MSG(extack,
"Nexthop configuration can not contain both GATEWAY and VIA");
goto errout;
}
return 0;
errout:
return err;
}
static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct fib_config cfg;
struct fib_table *tb;
int err;
err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
if (err < 0)
goto errout;
if (cfg.fc_nh_id && !nexthop_find_by_id(net, cfg.fc_nh_id)) {
NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
err = -EINVAL;
goto errout;
}
tb = fib_get_table(net, cfg.fc_table);
if (!tb) {
NL_SET_ERR_MSG(extack, "FIB table does not exist");
err = -ESRCH;
goto errout;
}
err = fib_table_delete(net, tb, &cfg, extack);
errout:
return err;
}
static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct fib_config cfg;
struct fib_table *tb;
int err;
err = rtm_to_fib_config(net, skb, nlh, &cfg, extack);
if (err < 0)
goto errout;
tb = fib_new_table(net, cfg.fc_table);
if (!tb) {
err = -ENOBUFS;
goto errout;
}
err = fib_table_insert(net, tb, &cfg, extack);
if (!err && cfg.fc_type == RTN_LOCAL)
net->ipv4.fib_has_custom_local_routes = true;
errout:
return err;
}
int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
struct fib_dump_filter *filter,
struct netlink_callback *cb)
{
struct netlink_ext_ack *extack = cb->extack;
struct nlattr *tb[RTA_MAX + 1];
struct rtmsg *rtm;
int err, i;
ASSERT_RTNL();
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
NL_SET_ERR_MSG(extack, "Invalid header for FIB dump request");
return -EINVAL;
}
rtm = nlmsg_data(nlh);
if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
rtm->rtm_scope) {
NL_SET_ERR_MSG(extack, "Invalid values in header for FIB dump request");
return -EINVAL;
}
if (rtm->rtm_flags & ~(RTM_F_CLONED | RTM_F_PREFIX)) {
NL_SET_ERR_MSG(extack, "Invalid flags for FIB dump request");
return -EINVAL;
}
if (rtm->rtm_flags & RTM_F_CLONED)
filter->dump_routes = false;
else
filter->dump_exceptions = false;
filter->flags = rtm->rtm_flags;
filter->protocol = rtm->rtm_protocol;
filter->rt_type = rtm->rtm_type;
filter->table_id = rtm->rtm_table;
err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
rtm_ipv4_policy, extack);
if (err < 0)
return err;
for (i = 0; i <= RTA_MAX; ++i) {
int ifindex;
if (!tb[i])
continue;
switch (i) {
case RTA_TABLE:
filter->table_id = nla_get_u32(tb[i]);
break;
case RTA_OIF:
ifindex = nla_get_u32(tb[i]);
filter->dev = __dev_get_by_index(net, ifindex);
if (!filter->dev)
return -ENODEV;
break;
default:
NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
return -EINVAL;
}
}
if (filter->flags || filter->protocol || filter->rt_type ||
filter->table_id || filter->dev) {
filter->filter_set = 1;
cb->answer_flags = NLM_F_DUMP_FILTERED;
}
return 0;
}
EXPORT_SYMBOL_GPL(ip_valid_fib_dump_req);
static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
{
struct fib_dump_filter filter = { .dump_routes = true,
.dump_exceptions = true };
const struct nlmsghdr *nlh = cb->nlh;
struct net *net = sock_net(skb->sk);
unsigned int h, s_h;
unsigned int e = 0, s_e;
struct fib_table *tb;
struct hlist_head *head;
int dumped = 0, err;
if (cb->strict_check) {
err = ip_valid_fib_dump_req(net, nlh, &filter, cb);
if (err < 0)
return err;
} else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
struct rtmsg *rtm = nlmsg_data(nlh);
filter.flags = rtm->rtm_flags & (RTM_F_PREFIX | RTM_F_CLONED);
}
/* ipv4 does not use prefix flag */
if (filter.flags & RTM_F_PREFIX)
return skb->len;
if (filter.table_id) {
tb = fib_get_table(net, filter.table_id);
if (!tb) {
if (rtnl_msg_family(cb->nlh) != PF_INET)
return skb->len;
NL_SET_ERR_MSG(cb->extack, "ipv4: FIB table does not exist");
return -ENOENT;
}
rcu_read_lock();