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linux-stable/net/core/fib_rules.c
Johannes Berg a885a6b2d3 net: convert to nla_get_*_default() 
Most of the original conversion is from the spatch below,
but I edited some and left out other instances that were
either buggy after conversion (where default values don't
fit into the type) or just looked strange.

    @@
    expression attr, def;
    expression val;
    identifier fn =~ "^nla_get_.*";
    fresh identifier dfn = fn ## "_default";
    @@
    (
    -if (attr)
    -  val = fn(attr);
    -else
    -  val = def;
    +val = dfn(attr, def);
    |
    -if (!attr)
    -  val = def;
    -else
    -  val = fn(attr);
    +val = dfn(attr, def);
    |
    -if (!attr)
    -  return def;
    -return fn(attr);
    +return dfn(attr, def);
    |
    -attr ? fn(attr) : def
    +dfn(attr, def)
    |
    -!attr ? def : fn(attr)
    +dfn(attr, def)
    )

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org>
Link: https://patch.msgid.link/20241108114145.0580b8684e7f.I740beeaa2f70ebfc19bfca1045a24d6151992790@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-11 10:32:06 -08:00

1324 lines
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// SPDX-License-Identifier: GPL-2.0-only
/*
* net/core/fib_rules.c Generic Routing Rules
*
* Authors: Thomas Graf <tgraf@suug.ch>
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <net/inet_dscp.h>
#include <net/sock.h>
#include <net/fib_rules.h>
#include <net/ip_tunnels.h>
#include <linux/indirect_call_wrapper.h>
#if defined(CONFIG_IPV6) && defined(CONFIG_IPV6_MULTIPLE_TABLES)
#ifdef CONFIG_IP_MULTIPLE_TABLES
#define INDIRECT_CALL_MT(f, f2, f1, ...) \
INDIRECT_CALL_INET(f, f2, f1, __VA_ARGS__)
#else
#define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
#endif
#elif defined(CONFIG_IP_MULTIPLE_TABLES)
#define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
#else
#define INDIRECT_CALL_MT(f, f2, f1, ...) f(__VA_ARGS__)
#endif
static const struct fib_kuid_range fib_kuid_range_unset = {
KUIDT_INIT(0),
KUIDT_INIT(~0),
};
bool fib_rule_matchall(const struct fib_rule *rule)
{
if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
rule->flags)
return false;
if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
return false;
if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
!uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
return false;
if (fib_rule_port_range_set(&rule->sport_range))
return false;
if (fib_rule_port_range_set(&rule->dport_range))
return false;
return true;
}
EXPORT_SYMBOL_GPL(fib_rule_matchall);
int fib_default_rule_add(struct fib_rules_ops *ops,
u32 pref, u32 table)
{
struct fib_rule *r;
r = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT);
if (r == NULL)
return -ENOMEM;
refcount_set(&r->refcnt, 1);
r->action = FR_ACT_TO_TBL;
r->pref = pref;
r->table = table;
r->proto = RTPROT_KERNEL;
r->fr_net = ops->fro_net;
r->uid_range = fib_kuid_range_unset;
r->suppress_prefixlen = -1;
r->suppress_ifgroup = -1;
/* The lock is not required here, the list in unreachable
* at the moment this function is called */
list_add_tail(&r->list, &ops->rules_list);
return 0;
}
EXPORT_SYMBOL(fib_default_rule_add);
static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
{
struct list_head *pos;
struct fib_rule *rule;
if (!list_empty(&ops->rules_list)) {
pos = ops->rules_list.next;
if (pos->next != &ops->rules_list) {
rule = list_entry(pos->next, struct fib_rule, list);
if (rule->pref)
return rule->pref - 1;
}
}
return 0;
}
static void notify_rule_change(int event, struct fib_rule *rule,
struct fib_rules_ops *ops, struct nlmsghdr *nlh,
u32 pid);
static struct fib_rules_ops *lookup_rules_ops(const struct net *net,
int family)
{
struct fib_rules_ops *ops;
rcu_read_lock();
list_for_each_entry_rcu(ops, &net->rules_ops, list) {
if (ops->family == family) {
if (!try_module_get(ops->owner))
ops = NULL;
rcu_read_unlock();
return ops;
}
}
rcu_read_unlock();
return NULL;
}
static void rules_ops_put(struct fib_rules_ops *ops)
{
if (ops)
module_put(ops->owner);
}
static void flush_route_cache(struct fib_rules_ops *ops)
{
if (ops->flush_cache)
ops->flush_cache(ops);
}
static int __fib_rules_register(struct fib_rules_ops *ops)
{
int err = -EEXIST;
struct fib_rules_ops *o;
struct net *net;
net = ops->fro_net;
if (ops->rule_size < sizeof(struct fib_rule))
return -EINVAL;
if (ops->match == NULL || ops->configure == NULL ||
ops->compare == NULL || ops->fill == NULL ||
ops->action == NULL)
return -EINVAL;
spin_lock(&net->rules_mod_lock);
list_for_each_entry(o, &net->rules_ops, list)
if (ops->family == o->family)
goto errout;
list_add_tail_rcu(&ops->list, &net->rules_ops);
err = 0;
errout:
spin_unlock(&net->rules_mod_lock);
return err;
}
struct fib_rules_ops *
fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
{
struct fib_rules_ops *ops;
int err;
ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
if (ops == NULL)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&ops->rules_list);
ops->fro_net = net;
err = __fib_rules_register(ops);
if (err) {
kfree(ops);
ops = ERR_PTR(err);
}
return ops;
}
EXPORT_SYMBOL_GPL(fib_rules_register);
static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
{
struct fib_rule *rule, *tmp;
list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
list_del_rcu(&rule->list);
if (ops->delete)
ops->delete(rule);
fib_rule_put(rule);
}
}
void fib_rules_unregister(struct fib_rules_ops *ops)
{
struct net *net = ops->fro_net;
spin_lock(&net->rules_mod_lock);
list_del_rcu(&ops->list);
spin_unlock(&net->rules_mod_lock);
fib_rules_cleanup_ops(ops);
kfree_rcu(ops, rcu);
}
EXPORT_SYMBOL_GPL(fib_rules_unregister);
static int uid_range_set(struct fib_kuid_range *range)
{
return uid_valid(range->start) && uid_valid(range->end);
}
static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
{
struct fib_rule_uid_range *in;
struct fib_kuid_range out;
in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
out.start = make_kuid(current_user_ns(), in->start);
out.end = make_kuid(current_user_ns(), in->end);
return out;
}
static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
{
struct fib_rule_uid_range out = {
from_kuid_munged(current_user_ns(), range->start),
from_kuid_munged(current_user_ns(), range->end)
};
return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
}
static int nla_get_port_range(struct nlattr *pattr,
struct fib_rule_port_range *port_range)
{
const struct fib_rule_port_range *pr = nla_data(pattr);
if (!fib_rule_port_range_valid(pr))
return -EINVAL;
port_range->start = pr->start;
port_range->end = pr->end;
return 0;
}
static int nla_put_port_range(struct sk_buff *skb, int attrtype,
struct fib_rule_port_range *range)
{
return nla_put(skb, attrtype, sizeof(*range), range);
}
static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
struct flowi *fl, int flags,
struct fib_lookup_arg *arg)
{
int ret = 0;
if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
goto out;
if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
goto out;
if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
goto out;
if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
goto out;
if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
goto out;
if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
uid_gt(fl->flowi_uid, rule->uid_range.end))
goto out;
ret = INDIRECT_CALL_MT(ops->match,
fib6_rule_match,
fib4_rule_match,
rule, fl, flags);
out:
return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
}
int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
int flags, struct fib_lookup_arg *arg)
{
struct fib_rule *rule;
int err;
rcu_read_lock();
list_for_each_entry_rcu(rule, &ops->rules_list, list) {
jumped:
if (!fib_rule_match(rule, ops, fl, flags, arg))
continue;
if (rule->action == FR_ACT_GOTO) {
struct fib_rule *target;
target = rcu_dereference(rule->ctarget);
if (target == NULL) {
continue;
} else {
rule = target;
goto jumped;
}
} else if (rule->action == FR_ACT_NOP)
continue;
else
err = INDIRECT_CALL_MT(ops->action,
fib6_rule_action,
fib4_rule_action,
rule, fl, flags, arg);
if (!err && ops->suppress && INDIRECT_CALL_MT(ops->suppress,
fib6_rule_suppress,
fib4_rule_suppress,
rule, flags, arg))
continue;
if (err != -EAGAIN) {
if ((arg->flags & FIB_LOOKUP_NOREF) ||
likely(refcount_inc_not_zero(&rule->refcnt))) {
arg->rule = rule;
goto out;
}
break;
}
}
err = -ESRCH;
out:
rcu_read_unlock();
return err;
}
EXPORT_SYMBOL_GPL(fib_rules_lookup);
static int call_fib_rule_notifier(struct notifier_block *nb,
enum fib_event_type event_type,
struct fib_rule *rule, int family,
struct netlink_ext_ack *extack)
{
struct fib_rule_notifier_info info = {
.info.family = family,
.info.extack = extack,
.rule = rule,
};
return call_fib_notifier(nb, event_type, &info.info);
}
static int call_fib_rule_notifiers(struct net *net,
enum fib_event_type event_type,
struct fib_rule *rule,
struct fib_rules_ops *ops,
struct netlink_ext_ack *extack)
{
struct fib_rule_notifier_info info = {
.info.family = ops->family,
.info.extack = extack,
.rule = rule,
};
ASSERT_RTNL();
/* Paired with READ_ONCE() in fib_rules_seq() */
WRITE_ONCE(ops->fib_rules_seq, ops->fib_rules_seq + 1);
return call_fib_notifiers(net, event_type, &info.info);
}
/* Called with rcu_read_lock() */
int fib_rules_dump(struct net *net, struct notifier_block *nb, int family,
struct netlink_ext_ack *extack)
{
struct fib_rules_ops *ops;
struct fib_rule *rule;
int err = 0;
ops = lookup_rules_ops(net, family);
if (!ops)
return -EAFNOSUPPORT;
list_for_each_entry_rcu(rule, &ops->rules_list, list) {
err = call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD,
rule, family, extack);
if (err)
break;
}
rules_ops_put(ops);
return err;
}
EXPORT_SYMBOL_GPL(fib_rules_dump);
unsigned int fib_rules_seq_read(const struct net *net, int family)
{
unsigned int fib_rules_seq;
struct fib_rules_ops *ops;
ops = lookup_rules_ops(net, family);
if (!ops)
return 0;
/* Paired with WRITE_ONCE() in call_fib_rule_notifiers() */
fib_rules_seq = READ_ONCE(ops->fib_rules_seq);
rules_ops_put(ops);
return fib_rules_seq;
}
EXPORT_SYMBOL_GPL(fib_rules_seq_read);
static struct fib_rule *rule_find(struct fib_rules_ops *ops,
struct fib_rule_hdr *frh,
struct nlattr **tb,
struct fib_rule *rule,
bool user_priority)
{
struct fib_rule *r;
list_for_each_entry(r, &ops->rules_list, list) {
if (rule->action && r->action != rule->action)
continue;
if (rule->table && r->table != rule->table)
continue;
if (user_priority && r->pref != rule->pref)
continue;
if (rule->iifname[0] &&
memcmp(r->iifname, rule->iifname, IFNAMSIZ))
continue;
if (rule->oifname[0] &&
memcmp(r->oifname, rule->oifname, IFNAMSIZ))
continue;
if (rule->mark && r->mark != rule->mark)
continue;
if (rule->suppress_ifgroup != -1 &&
r->suppress_ifgroup != rule->suppress_ifgroup)
continue;
if (rule->suppress_prefixlen != -1 &&
r->suppress_prefixlen != rule->suppress_prefixlen)
continue;
if (rule->mark_mask && r->mark_mask != rule->mark_mask)
continue;
if (rule->tun_id && r->tun_id != rule->tun_id)
continue;
if (r->fr_net != rule->fr_net)
continue;
if (rule->l3mdev && r->l3mdev != rule->l3mdev)
continue;
if (uid_range_set(&rule->uid_range) &&
(!uid_eq(r->uid_range.start, rule->uid_range.start) ||
!uid_eq(r->uid_range.end, rule->uid_range.end)))
continue;
if (rule->ip_proto && r->ip_proto != rule->ip_proto)
continue;
if (rule->proto && r->proto != rule->proto)
continue;
if (fib_rule_port_range_set(&rule->sport_range) &&
!fib_rule_port_range_compare(&r->sport_range,
&rule->sport_range))
continue;
if (fib_rule_port_range_set(&rule->dport_range) &&
!fib_rule_port_range_compare(&r->dport_range,
&rule->dport_range))
continue;
if (!ops->compare(r, frh, tb))
continue;
return r;
}
return NULL;
}
#ifdef CONFIG_NET_L3_MASTER_DEV
static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
struct netlink_ext_ack *extack)
{
nlrule->l3mdev = nla_get_u8(nla);
if (nlrule->l3mdev != 1) {
NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute");
return -1;
}
return 0;
}
#else
static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
struct netlink_ext_ack *extack)
{
NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel");
return -1;
}
#endif
static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack,
struct fib_rules_ops *ops,
struct nlattr *tb[],
struct fib_rule **rule,
bool *user_priority)
{
struct net *net = sock_net(skb->sk);
struct fib_rule_hdr *frh = nlmsg_data(nlh);
struct fib_rule *nlrule = NULL;
int err = -EINVAL;
if (frh->src_len)
if (!tb[FRA_SRC] ||
frh->src_len > (ops->addr_size * 8) ||
nla_len(tb[FRA_SRC]) != ops->addr_size) {
NL_SET_ERR_MSG(extack, "Invalid source address");
goto errout;
}
if (frh->dst_len)
if (!tb[FRA_DST] ||
frh->dst_len > (ops->addr_size * 8) ||
nla_len(tb[FRA_DST]) != ops->addr_size) {
NL_SET_ERR_MSG(extack, "Invalid dst address");
goto errout;
}
nlrule = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT);
if (!nlrule) {
err = -ENOMEM;
goto errout;
}
refcount_set(&nlrule->refcnt, 1);
nlrule->fr_net = net;
if (tb[FRA_PRIORITY]) {
nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]);
*user_priority = true;
} else {
nlrule->pref = fib_default_rule_pref(ops);
}
nlrule->proto = nla_get_u8_default(tb[FRA_PROTOCOL], RTPROT_UNSPEC);
if (tb[FRA_IIFNAME]) {
struct net_device *dev;
nlrule->iifindex = -1;
nla_strscpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
dev = __dev_get_by_name(net, nlrule->iifname);
if (dev)
nlrule->iifindex = dev->ifindex;
}
if (tb[FRA_OIFNAME]) {
struct net_device *dev;
nlrule->oifindex = -1;
nla_strscpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
dev = __dev_get_by_name(net, nlrule->oifname);
if (dev)
nlrule->oifindex = dev->ifindex;
}
if (tb[FRA_FWMARK]) {
nlrule->mark = nla_get_u32(tb[FRA_FWMARK]);
if (nlrule->mark)
/* compatibility: if the mark value is non-zero all bits
* are compared unless a mask is explicitly specified.
*/
nlrule->mark_mask = 0xFFFFFFFF;
}
if (tb[FRA_FWMASK])
nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
if (tb[FRA_TUN_ID])
nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
if (tb[FRA_L3MDEV] &&
fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0)
goto errout_free;
nlrule->action = frh->action;
nlrule->flags = frh->flags;
nlrule->table = frh_get_table(frh, tb);
if (tb[FRA_SUPPRESS_PREFIXLEN])
nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
else
nlrule->suppress_prefixlen = -1;
if (tb[FRA_SUPPRESS_IFGROUP])
nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
else
nlrule->suppress_ifgroup = -1;
if (tb[FRA_GOTO]) {
if (nlrule->action != FR_ACT_GOTO) {
NL_SET_ERR_MSG(extack, "Unexpected goto");
goto errout_free;
}
nlrule->target = nla_get_u32(tb[FRA_GOTO]);
/* Backward jumps are prohibited to avoid endless loops */
if (nlrule->target <= nlrule->pref) {
NL_SET_ERR_MSG(extack, "Backward goto not supported");
goto errout_free;
}
} else if (nlrule->action == FR_ACT_GOTO) {
NL_SET_ERR_MSG(extack, "Missing goto target for action goto");
goto errout_free;
}
if (nlrule->l3mdev && nlrule->table) {
NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive");
goto errout_free;
}
if (tb[FRA_UID_RANGE]) {
if (current_user_ns() != net->user_ns) {
err = -EPERM;
NL_SET_ERR_MSG(extack, "No permission to set uid");
goto errout_free;
}
nlrule->uid_range = nla_get_kuid_range(tb);
if (!uid_range_set(&nlrule->uid_range) ||
!uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) {
NL_SET_ERR_MSG(extack, "Invalid uid range");
goto errout_free;
}
} else {
nlrule->uid_range = fib_kuid_range_unset;
}
if (tb[FRA_IP_PROTO])
nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
if (tb[FRA_SPORT_RANGE]) {
err = nla_get_port_range(tb[FRA_SPORT_RANGE],
&nlrule->sport_range);
if (err) {
NL_SET_ERR_MSG(extack, "Invalid sport range");
goto errout_free;
}
}
if (tb[FRA_DPORT_RANGE]) {
err = nla_get_port_range(tb[FRA_DPORT_RANGE],
&nlrule->dport_range);
if (err) {
NL_SET_ERR_MSG(extack, "Invalid dport range");
goto errout_free;
}
}
*rule = nlrule;
return 0;
errout_free:
kfree(nlrule);
errout:
return err;
}
static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
struct nlattr **tb, struct fib_rule *rule)
{
struct fib_rule *r;
list_for_each_entry(r, &ops->rules_list, list) {
if (r->action != rule->action)
continue;
if (r->table != rule->table)
continue;
if (r->pref != rule->pref)
continue;
if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
continue;
if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
continue;
if (r->mark != rule->mark)
continue;
if (r->suppress_ifgroup != rule->suppress_ifgroup)
continue;
if (r->suppress_prefixlen != rule->suppress_prefixlen)
continue;
if (r->mark_mask != rule->mark_mask)
continue;
if (r->tun_id != rule->tun_id)
continue;
if (r->fr_net != rule->fr_net)
continue;
if (r->l3mdev != rule->l3mdev)
continue;
if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
!uid_eq(r->uid_range.end, rule->uid_range.end))
continue;
if (r->ip_proto != rule->ip_proto)
continue;
if (r->proto != rule->proto)
continue;
if (!fib_rule_port_range_compare(&r->sport_range,
&rule->sport_range))
continue;
if (!fib_rule_port_range_compare(&r->dport_range,
&rule->dport_range))
continue;
if (!ops->compare(r, frh, tb))
continue;
return 1;
}
return 0;
}
static const struct nla_policy fib_rule_policy[FRA_MAX + 1] = {
[FRA_UNSPEC] = { .strict_start_type = FRA_DPORT_RANGE + 1 },
[FRA_IIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
[FRA_OIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
[FRA_PRIORITY] = { .type = NLA_U32 },
[FRA_FWMARK] = { .type = NLA_U32 },
[FRA_FLOW] = { .type = NLA_U32 },
[FRA_TUN_ID] = { .type = NLA_U64 },
[FRA_FWMASK] = { .type = NLA_U32 },
[FRA_TABLE] = { .type = NLA_U32 },
[FRA_SUPPRESS_PREFIXLEN] = { .type = NLA_U32 },
[FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 },
[FRA_GOTO] = { .type = NLA_U32 },
[FRA_L3MDEV] = { .type = NLA_U8 },
[FRA_UID_RANGE] = { .len = sizeof(struct fib_rule_uid_range) },
[FRA_PROTOCOL] = { .type = NLA_U8 },
[FRA_IP_PROTO] = { .type = NLA_U8 },
[FRA_SPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) },
[FRA_DPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) },
[FRA_DSCP] = NLA_POLICY_MAX(NLA_U8, INET_DSCP_MASK >> 2),
};
int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct fib_rule_hdr *frh = nlmsg_data(nlh);
struct fib_rules_ops *ops = NULL;
struct fib_rule *rule = NULL, *r, *last = NULL;
struct nlattr *tb[FRA_MAX + 1];
int err = -EINVAL, unresolved = 0;
bool user_priority = false;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
NL_SET_ERR_MSG(extack, "Invalid msg length");
goto errout;
}
ops = lookup_rules_ops(net, frh->family);
if (!ops) {
err = -EAFNOSUPPORT;
NL_SET_ERR_MSG(extack, "Rule family not supported");
goto errout;
}
err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
fib_rule_policy, extack);
if (err < 0) {
NL_SET_ERR_MSG(extack, "Error parsing msg");
goto errout;
}
err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority);
if (err)
goto errout;
if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
rule_exists(ops, frh, tb, rule)) {
err = -EEXIST;
goto errout_free;
}
err = ops->configure(rule, skb, frh, tb, extack);
if (err < 0)
goto errout_free;
err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
extack);
if (err < 0)
goto errout_free;
list_for_each_entry(r, &ops->rules_list, list) {
if (r->pref == rule->target) {
RCU_INIT_POINTER(rule->ctarget, r);
break;
}
}
if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
unresolved = 1;
list_for_each_entry(r, &ops->rules_list, list) {
if (r->pref > rule->pref)
break;
last = r;
}
if (last)
list_add_rcu(&rule->list, &last->list);
else
list_add_rcu(&rule->list, &ops->rules_list);
if (ops->unresolved_rules) {
/*
* There are unresolved goto rules in the list, check if
* any of them are pointing to this new rule.
*/
list_for_each_entry(r, &ops->rules_list, list) {
if (r->action == FR_ACT_GOTO &&
r->target == rule->pref &&
rtnl_dereference(r->ctarget) == NULL) {
rcu_assign_pointer(r->ctarget, rule);
if (--ops->unresolved_rules == 0)
break;
}
}
}
if (rule->action == FR_ACT_GOTO)
ops->nr_goto_rules++;
if (unresolved)
ops->unresolved_rules++;
if (rule->tun_id)
ip_tunnel_need_metadata();
notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
flush_route_cache(ops);
rules_ops_put(ops);
return 0;
errout_free:
kfree(rule);
errout:
rules_ops_put(ops);
return err;
}
EXPORT_SYMBOL_GPL(fib_nl_newrule);
int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct fib_rule_hdr *frh = nlmsg_data(nlh);
struct fib_rules_ops *ops = NULL;
struct fib_rule *rule = NULL, *r, *nlrule = NULL;
struct nlattr *tb[FRA_MAX+1];
int err = -EINVAL;
bool user_priority = false;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
NL_SET_ERR_MSG(extack, "Invalid msg length");
goto errout;
}
ops = lookup_rules_ops(net, frh->family);
if (ops == NULL) {
err = -EAFNOSUPPORT;
NL_SET_ERR_MSG(extack, "Rule family not supported");
goto errout;
}
err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
fib_rule_policy, extack);
if (err < 0) {
NL_SET_ERR_MSG(extack, "Error parsing msg");
goto errout;
}
err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority);
if (err)
goto errout;
rule = rule_find(ops, frh, tb, nlrule, user_priority);
if (!rule) {
err = -ENOENT;
goto errout;
}
if (rule->flags & FIB_RULE_PERMANENT) {
err = -EPERM;
goto errout;
}
if (ops->delete) {
err = ops->delete(rule);
if (err)
goto errout;
}
if (rule->tun_id)
ip_tunnel_unneed_metadata();
list_del_rcu(&rule->list);
if (rule->action == FR_ACT_GOTO) {
ops->nr_goto_rules--;
if (rtnl_dereference(rule->ctarget) == NULL)
ops->unresolved_rules--;
}
/*
* Check if this rule is a target to any of them. If so,
* adjust to the next one with the same preference or
* disable them. As this operation is eventually very
* expensive, it is only performed if goto rules, except
* current if it is goto rule, have actually been added.
*/
if (ops->nr_goto_rules > 0) {
struct fib_rule *n;
n = list_next_entry(rule, list);
if (&n->list == &ops->rules_list || n->pref != rule->pref)
n = NULL;
list_for_each_entry(r, &ops->rules_list, list) {
if (rtnl_dereference(r->ctarget) != rule)
continue;
rcu_assign_pointer(r->ctarget, n);
if (!n)
ops->unresolved_rules++;
}
}
call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
NULL);
notify_rule_change(RTM_DELRULE, rule, ops, nlh,
NETLINK_CB(skb).portid);
fib_rule_put(rule);
flush_route_cache(ops);
rules_ops_put(ops);
kfree(nlrule);
return 0;
errout:
kfree(nlrule);
rules_ops_put(ops);
return err;
}
EXPORT_SYMBOL_GPL(fib_nl_delrule);
static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
struct fib_rule *rule)
{
size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
+ nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
+ nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
+ nla_total_size(4) /* FRA_PRIORITY */
+ nla_total_size(4) /* FRA_TABLE */
+ nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
+ nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
+ nla_total_size(4) /* FRA_FWMARK */
+ nla_total_size(4) /* FRA_FWMASK */
+ nla_total_size_64bit(8) /* FRA_TUN_ID */
+ nla_total_size(sizeof(struct fib_kuid_range))
+ nla_total_size(1) /* FRA_PROTOCOL */
+ nla_total_size(1) /* FRA_IP_PROTO */
+ nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
+ nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
if (ops->nlmsg_payload)
payload += ops->nlmsg_payload(rule);
return payload;
}
static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
u32 pid, u32 seq, int type, int flags,
struct fib_rules_ops *ops)
{
struct nlmsghdr *nlh;
struct fib_rule_hdr *frh;
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
if (nlh == NULL)
return -EMSGSIZE;
frh = nlmsg_data(nlh);
frh->family = ops->family;
frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT;
if (nla_put_u32(skb, FRA_TABLE, rule->table))
goto nla_put_failure;
if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
goto nla_put_failure;
frh->res1 = 0;
frh->res2 = 0;
frh->action = rule->action;
frh->flags = rule->flags;
if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
goto nla_put_failure;
if (rule->action == FR_ACT_GOTO &&
rcu_access_pointer(rule->ctarget) == NULL)
frh->flags |= FIB_RULE_UNRESOLVED;
if (rule->iifname[0]) {
if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
goto nla_put_failure;
if (rule->iifindex == -1)
frh->flags |= FIB_RULE_IIF_DETACHED;
}
if (rule->oifname[0]) {
if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
goto nla_put_failure;
if (rule->oifindex == -1)
frh->flags |= FIB_RULE_OIF_DETACHED;
}
if ((rule->pref &&
nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
(rule->mark &&
nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
((rule->mark_mask || rule->mark) &&
nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
(rule->target &&
nla_put_u32(skb, FRA_GOTO, rule->target)) ||
(rule->tun_id &&
nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
(rule->l3mdev &&
nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
(uid_range_set(&rule->uid_range) &&
nla_put_uid_range(skb, &rule->uid_range)) ||
(fib_rule_port_range_set(&rule->sport_range) &&
nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
(fib_rule_port_range_set(&rule->dport_range) &&
nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
(rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
goto nla_put_failure;
if (rule->suppress_ifgroup != -1) {
if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
goto nla_put_failure;
}
if (ops->fill(rule, skb, frh) < 0)
goto nla_put_failure;
nlmsg_end(skb, nlh);
return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
struct fib_rules_ops *ops)
{
int idx = 0;
struct fib_rule *rule;
int err = 0;
rcu_read_lock();
list_for_each_entry_rcu(rule, &ops->rules_list, list) {
if (idx < cb->args[1])
goto skip;
err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, RTM_NEWRULE,
NLM_F_MULTI, ops);
if (err)
break;
skip:
idx++;
}
rcu_read_unlock();
cb->args[1] = idx;
rules_ops_put(ops);
return err;
}
static int fib_valid_dumprule_req(const struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct fib_rule_hdr *frh;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request");
return -EINVAL;
}
frh = nlmsg_data(nlh);
if (frh->dst_len || frh->src_len || frh->tos || frh->table ||
frh->res1 || frh->res2 || frh->action || frh->flags) {
NL_SET_ERR_MSG(extack,
"Invalid values in header for fib rule dump request");
return -EINVAL;
}
if (nlmsg_attrlen(nlh, sizeof(*frh))) {
NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request");
return -EINVAL;
}
return 0;
}
static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
{
const struct nlmsghdr *nlh = cb->nlh;
struct net *net = sock_net(skb->sk);
struct fib_rules_ops *ops;
int err, idx = 0, family;
if (cb->strict_check) {
err = fib_valid_dumprule_req(nlh, cb->extack);
if (err < 0)
return err;
}
family = rtnl_msg_family(nlh);
if (family != AF_UNSPEC) {
/* Protocol specific dump request */
ops = lookup_rules_ops(net, family);
if (ops == NULL)
return -EAFNOSUPPORT;
return dump_rules(skb, cb, ops);
}
err = 0;
rcu_read_lock();
list_for_each_entry_rcu(ops, &net->rules_ops, list) {
if (idx < cb->args[0] || !try_module_get(ops->owner))
goto skip;
err = dump_rules(skb, cb, ops);
if (err < 0)
break;
cb->args[1] = 0;
skip:
idx++;
}
rcu_read_unlock();
cb->args[0] = idx;
return err;
}
static void notify_rule_change(int event, struct fib_rule *rule,
struct fib_rules_ops *ops, struct nlmsghdr *nlh,
u32 pid)
{
struct net *net;
struct sk_buff *skb;
int err = -ENOMEM;
net = ops->fro_net;
skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
if (skb == NULL)
goto errout;
err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
if (err < 0) {
/* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
return;
errout:
rtnl_set_sk_err(net, ops->nlgroup, err);
}
static void attach_rules(struct list_head *rules, struct net_device *dev)
{
struct fib_rule *rule;
list_for_each_entry(rule, rules, list) {
if (rule->iifindex == -1 &&
strcmp(dev->name, rule->iifname) == 0)
rule->iifindex = dev->ifindex;
if (rule->oifindex == -1 &&
strcmp(dev->name, rule->oifname) == 0)
rule->oifindex = dev->ifindex;
}
}
static void detach_rules(struct list_head *rules, struct net_device *dev)
{
struct fib_rule *rule;
list_for_each_entry(rule, rules, list) {
if (rule->iifindex == dev->ifindex)
rule->iifindex = -1;
if (rule->oifindex == dev->ifindex)
rule->oifindex = -1;
}
}
static int fib_rules_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct net *net = dev_net(dev);
struct fib_rules_ops *ops;
ASSERT_RTNL();
switch (event) {
case NETDEV_REGISTER:
list_for_each_entry(ops, &net->rules_ops, list)
attach_rules(&ops->rules_list, dev);
break;
case NETDEV_CHANGENAME:
list_for_each_entry(ops, &net->rules_ops, list) {
detach_rules(&ops->rules_list, dev);
attach_rules(&ops->rules_list, dev);
}
break;
case NETDEV_UNREGISTER:
list_for_each_entry(ops, &net->rules_ops, list)
detach_rules(&ops->rules_list, dev);
break;
}
return NOTIFY_DONE;
}
static struct notifier_block fib_rules_notifier = {
.notifier_call = fib_rules_event,
};
static int __net_init fib_rules_net_init(struct net *net)
{
INIT_LIST_HEAD(&net->rules_ops);
spin_lock_init(&net->rules_mod_lock);
return 0;
}
static void __net_exit fib_rules_net_exit(struct net *net)
{
WARN_ON_ONCE(!list_empty(&net->rules_ops));
}
static struct pernet_operations fib_rules_net_ops = {
.init = fib_rules_net_init,
.exit = fib_rules_net_exit,
};
static const struct rtnl_msg_handler fib_rules_rtnl_msg_handlers[] __initconst = {
{.msgtype = RTM_NEWRULE, .doit = fib_nl_newrule},
{.msgtype = RTM_DELRULE, .doit = fib_nl_delrule},
{.msgtype = RTM_GETRULE, .dumpit = fib_nl_dumprule,
.flags = RTNL_FLAG_DUMP_UNLOCKED},
};
static int __init fib_rules_init(void)
{
int err;
rtnl_register_many(fib_rules_rtnl_msg_handlers);
err = register_pernet_subsys(&fib_rules_net_ops);
if (err < 0)
goto fail;
err = register_netdevice_notifier(&fib_rules_notifier);
if (err < 0)
goto fail_unregister;
return 0;
fail_unregister:
unregister_pernet_subsys(&fib_rules_net_ops);
fail:
rtnl_unregister_many(fib_rules_rtnl_msg_handlers);
return err;
}
subsys_initcall(fib_rules_init);
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