/net/core/fib_rules.c
http://github.com/mirrors/linux · C · 1275 lines · 1014 code · 235 blank · 26 comment · 290 complexity · 8ba3cf8a5260be48e87ba4d67eb62171 MD5 · raw file
- // 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/sock.h>
- #include <net/fib_rules.h>
- #include <net/ip_tunnels.h>
- 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, u32 flags)
- {
- struct fib_rule *r;
- r = kzalloc(ops->rule_size, GFP_KERNEL);
- if (r == NULL)
- return -ENOMEM;
- refcount_set(&r->refcnt, 1);
- r->action = FR_ACT_TO_TBL;
- r->pref = pref;
- r->table = table;
- r->flags = flags;
- 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 unreacheable
- * 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(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 = ops->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 = ops->action(rule, fl, flags, arg);
- if (!err && ops->suppress && ops->suppress(rule, 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,
- };
- ops->fib_rules_seq++;
- 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(struct net *net, int family)
- {
- unsigned int fib_rules_seq;
- struct fib_rules_ops *ops;
- ASSERT_RTNL();
- ops = lookup_rules_ops(net, family);
- if (!ops)
- return 0;
- fib_rules_seq = 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);
- 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 = tb[FRA_PROTOCOL] ?
- nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
- if (tb[FRA_IIFNAME]) {
- struct net_device *dev;
- nlrule->iifindex = -1;
- nla_strlcpy(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_strlcpy(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]);
- err = -EINVAL;
- 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;
- }
- 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,
- ops->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,
- ops->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 idx = 0, family;
- if (cb->strict_check) {
- int 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;
- dump_rules(skb, cb, ops);
- return skb->len;
- }
- 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;
- if (dump_rules(skb, cb, ops) < 0)
- break;
- cb->args[1] = 0;
- skip:
- idx++;
- }
- rcu_read_unlock();
- cb->args[0] = idx;
- return skb->len;
- }
- 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 = -ENOBUFS;
- 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:
- if (err < 0)
- 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 int __init fib_rules_init(void)
- {
- int err;
- rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
- rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
- rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
- 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(PF_UNSPEC, RTM_NEWRULE);
- rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
- rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
- return err;
- }
- subsys_initcall(fib_rules_init);