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- // SPDX-License-Identifier: GPL-2.0
- /* Generic nexthop implementation
- *
- * Copyright (c) 2017-19 Cumulus Networks
- * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
- */
- #include <linux/nexthop.h>
- #include <linux/rtnetlink.h>
- #include <linux/slab.h>
- #include <net/arp.h>
- #include <net/ipv6_stubs.h>
- #include <net/lwtunnel.h>
- #include <net/ndisc.h>
- #include <net/nexthop.h>
- #include <net/route.h>
- #include <net/sock.h>
- static void remove_nexthop(struct net *net, struct nexthop *nh,
- struct nl_info *nlinfo);
- #define NH_DEV_HASHBITS 8
- #define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
- static const struct nla_policy rtm_nh_policy[NHA_MAX + 1] = {
- [NHA_ID] = { .type = NLA_U32 },
- [NHA_GROUP] = { .type = NLA_BINARY },
- [NHA_GROUP_TYPE] = { .type = NLA_U16 },
- [NHA_BLACKHOLE] = { .type = NLA_FLAG },
- [NHA_OIF] = { .type = NLA_U32 },
- [NHA_GATEWAY] = { .type = NLA_BINARY },
- [NHA_ENCAP_TYPE] = { .type = NLA_U16 },
- [NHA_ENCAP] = { .type = NLA_NESTED },
- [NHA_GROUPS] = { .type = NLA_FLAG },
- [NHA_MASTER] = { .type = NLA_U32 },
- [NHA_FDB] = { .type = NLA_FLAG },
- };
- static int call_nexthop_notifiers(struct net *net,
- enum nexthop_event_type event_type,
- struct nexthop *nh)
- {
- int err;
- err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
- event_type, nh);
- return notifier_to_errno(err);
- }
- static unsigned int nh_dev_hashfn(unsigned int val)
- {
- unsigned int mask = NH_DEV_HASHSIZE - 1;
- return (val ^
- (val >> NH_DEV_HASHBITS) ^
- (val >> (NH_DEV_HASHBITS * 2))) & mask;
- }
- static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
- {
- struct net_device *dev = nhi->fib_nhc.nhc_dev;
- struct hlist_head *head;
- unsigned int hash;
- WARN_ON(!dev);
- hash = nh_dev_hashfn(dev->ifindex);
- head = &net->nexthop.devhash[hash];
- hlist_add_head(&nhi->dev_hash, head);
- }
- static void nexthop_free_mpath(struct nexthop *nh)
- {
- struct nh_group *nhg;
- int i;
- nhg = rcu_dereference_raw(nh->nh_grp);
- for (i = 0; i < nhg->num_nh; ++i) {
- struct nh_grp_entry *nhge = &nhg->nh_entries[i];
- WARN_ON(!list_empty(&nhge->nh_list));
- nexthop_put(nhge->nh);
- }
- WARN_ON(nhg->spare == nhg);
- kfree(nhg->spare);
- kfree(nhg);
- }
- static void nexthop_free_single(struct nexthop *nh)
- {
- struct nh_info *nhi;
- nhi = rcu_dereference_raw(nh->nh_info);
- switch (nhi->family) {
- case AF_INET:
- fib_nh_release(nh->net, &nhi->fib_nh);
- break;
- case AF_INET6:
- ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
- break;
- }
- kfree(nhi);
- }
- void nexthop_free_rcu(struct rcu_head *head)
- {
- struct nexthop *nh = container_of(head, struct nexthop, rcu);
- if (nh->is_group)
- nexthop_free_mpath(nh);
- else
- nexthop_free_single(nh);
- kfree(nh);
- }
- EXPORT_SYMBOL_GPL(nexthop_free_rcu);
- static struct nexthop *nexthop_alloc(void)
- {
- struct nexthop *nh;
- nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
- if (nh) {
- INIT_LIST_HEAD(&nh->fi_list);
- INIT_LIST_HEAD(&nh->f6i_list);
- INIT_LIST_HEAD(&nh->grp_list);
- INIT_LIST_HEAD(&nh->fdb_list);
- }
- return nh;
- }
- static struct nh_group *nexthop_grp_alloc(u16 num_nh)
- {
- struct nh_group *nhg;
- nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL);
- if (nhg)
- nhg->num_nh = num_nh;
- return nhg;
- }
- static void nh_base_seq_inc(struct net *net)
- {
- while (++net->nexthop.seq == 0)
- ;
- }
- /* no reference taken; rcu lock or rtnl must be held */
- struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
- {
- struct rb_node **pp, *parent = NULL, *next;
- pp = &net->nexthop.rb_root.rb_node;
- while (1) {
- struct nexthop *nh;
- next = rcu_dereference_raw(*pp);
- if (!next)
- break;
- parent = next;
- nh = rb_entry(parent, struct nexthop, rb_node);
- if (id < nh->id)
- pp = &next->rb_left;
- else if (id > nh->id)
- pp = &next->rb_right;
- else
- return nh;
- }
- return NULL;
- }
- EXPORT_SYMBOL_GPL(nexthop_find_by_id);
- /* used for auto id allocation; called with rtnl held */
- static u32 nh_find_unused_id(struct net *net)
- {
- u32 id_start = net->nexthop.last_id_allocated;
- while (1) {
- net->nexthop.last_id_allocated++;
- if (net->nexthop.last_id_allocated == id_start)
- break;
- if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
- return net->nexthop.last_id_allocated;
- }
- return 0;
- }
- static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
- {
- struct nexthop_grp *p;
- size_t len = nhg->num_nh * sizeof(*p);
- struct nlattr *nla;
- u16 group_type = 0;
- int i;
- if (nhg->mpath)
- group_type = NEXTHOP_GRP_TYPE_MPATH;
- if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
- goto nla_put_failure;
- nla = nla_reserve(skb, NHA_GROUP, len);
- if (!nla)
- goto nla_put_failure;
- p = nla_data(nla);
- for (i = 0; i < nhg->num_nh; ++i) {
- p->id = nhg->nh_entries[i].nh->id;
- p->weight = nhg->nh_entries[i].weight - 1;
- p += 1;
- }
- return 0;
- nla_put_failure:
- return -EMSGSIZE;
- }
- static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
- int event, u32 portid, u32 seq, unsigned int nlflags)
- {
- struct fib6_nh *fib6_nh;
- struct fib_nh *fib_nh;
- struct nlmsghdr *nlh;
- struct nh_info *nhi;
- struct nhmsg *nhm;
- nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
- if (!nlh)
- return -EMSGSIZE;
- nhm = nlmsg_data(nlh);
- nhm->nh_family = AF_UNSPEC;
- nhm->nh_flags = nh->nh_flags;
- nhm->nh_protocol = nh->protocol;
- nhm->nh_scope = 0;
- nhm->resvd = 0;
- if (nla_put_u32(skb, NHA_ID, nh->id))
- goto nla_put_failure;
- if (nh->is_group) {
- struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
- if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB))
- goto nla_put_failure;
- if (nla_put_nh_group(skb, nhg))
- goto nla_put_failure;
- goto out;
- }
- nhi = rtnl_dereference(nh->nh_info);
- nhm->nh_family = nhi->family;
- if (nhi->reject_nh) {
- if (nla_put_flag(skb, NHA_BLACKHOLE))
- goto nla_put_failure;
- goto out;
- } else if (nhi->fdb_nh) {
- if (nla_put_flag(skb, NHA_FDB))
- goto nla_put_failure;
- } else {
- const struct net_device *dev;
- dev = nhi->fib_nhc.nhc_dev;
- if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
- goto nla_put_failure;
- }
- nhm->nh_scope = nhi->fib_nhc.nhc_scope;
- switch (nhi->family) {
- case AF_INET:
- fib_nh = &nhi->fib_nh;
- if (fib_nh->fib_nh_gw_family &&
- nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
- goto nla_put_failure;
- break;
- case AF_INET6:
- fib6_nh = &nhi->fib6_nh;
- if (fib6_nh->fib_nh_gw_family &&
- nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
- goto nla_put_failure;
- break;
- }
- if (nhi->fib_nhc.nhc_lwtstate &&
- lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
- NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
- goto nla_put_failure;
- out:
- nlmsg_end(skb, nlh);
- return 0;
- nla_put_failure:
- nlmsg_cancel(skb, nlh);
- return -EMSGSIZE;
- }
- static size_t nh_nlmsg_size_grp(struct nexthop *nh)
- {
- struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
- size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
- return nla_total_size(sz) +
- nla_total_size(2); /* NHA_GROUP_TYPE */
- }
- static size_t nh_nlmsg_size_single(struct nexthop *nh)
- {
- struct nh_info *nhi = rtnl_dereference(nh->nh_info);
- size_t sz;
- /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
- * are mutually exclusive
- */
- sz = nla_total_size(4); /* NHA_OIF */
- switch (nhi->family) {
- case AF_INET:
- if (nhi->fib_nh.fib_nh_gw_family)
- sz += nla_total_size(4); /* NHA_GATEWAY */
- break;
- case AF_INET6:
- /* NHA_GATEWAY */
- if (nhi->fib6_nh.fib_nh_gw_family)
- sz += nla_total_size(sizeof(const struct in6_addr));
- break;
- }
- if (nhi->fib_nhc.nhc_lwtstate) {
- sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
- sz += nla_total_size(2); /* NHA_ENCAP_TYPE */
- }
- return sz;
- }
- static size_t nh_nlmsg_size(struct nexthop *nh)
- {
- size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg));
- sz += nla_total_size(4); /* NHA_ID */
- if (nh->is_group)
- sz += nh_nlmsg_size_grp(nh);
- else
- sz += nh_nlmsg_size_single(nh);
- return sz;
- }
- static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
- {
- unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
- u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
- struct sk_buff *skb;
- int err = -ENOBUFS;
- skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
- if (!skb)
- goto errout;
- err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
- if (err < 0) {
- /* -EMSGSIZE implies BUG in nh_nlmsg_size() */
- WARN_ON(err == -EMSGSIZE);
- kfree_skb(skb);
- goto errout;
- }
- rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
- info->nlh, gfp_any());
- return;
- errout:
- if (err < 0)
- rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
- }
- static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
- bool *is_fdb, struct netlink_ext_ack *extack)
- {
- if (nh->is_group) {
- struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
- /* nested multipath (group within a group) is not
- * supported
- */
- if (nhg->mpath) {
- NL_SET_ERR_MSG(extack,
- "Multipath group can not be a nexthop within a group");
- return false;
- }
- *is_fdb = nhg->fdb_nh;
- } else {
- struct nh_info *nhi = rtnl_dereference(nh->nh_info);
- if (nhi->reject_nh && npaths > 1) {
- NL_SET_ERR_MSG(extack,
- "Blackhole nexthop can not be used in a group with more than 1 path");
- return false;
- }
- *is_fdb = nhi->fdb_nh;
- }
- return true;
- }
- static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family,
- struct netlink_ext_ack *extack)
- {
- struct nh_info *nhi;
- nhi = rtnl_dereference(nh->nh_info);
- if (!nhi->fdb_nh) {
- NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops");
- return -EINVAL;
- }
- if (*nh_family == AF_UNSPEC) {
- *nh_family = nhi->family;
- } else if (*nh_family != nhi->family) {
- NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops");
- return -EINVAL;
- }
- return 0;
- }
- static int nh_check_attr_group(struct net *net, struct nlattr *tb[],
- struct netlink_ext_ack *extack)
- {
- unsigned int len = nla_len(tb[NHA_GROUP]);
- u8 nh_family = AF_UNSPEC;
- struct nexthop_grp *nhg;
- unsigned int i, j;
- u8 nhg_fdb = 0;
- if (!len || len & (sizeof(struct nexthop_grp) - 1)) {
- NL_SET_ERR_MSG(extack,
- "Invalid length for nexthop group attribute");
- return -EINVAL;
- }
- /* convert len to number of nexthop ids */
- len /= sizeof(*nhg);
- nhg = nla_data(tb[NHA_GROUP]);
- for (i = 0; i < len; ++i) {
- if (nhg[i].resvd1 || nhg[i].resvd2) {
- NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
- return -EINVAL;
- }
- if (nhg[i].weight > 254) {
- NL_SET_ERR_MSG(extack, "Invalid value for weight");
- return -EINVAL;
- }
- for (j = i + 1; j < len; ++j) {
- if (nhg[i].id == nhg[j].id) {
- NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
- return -EINVAL;
- }
- }
- }
- if (tb[NHA_FDB])
- nhg_fdb = 1;
- nhg = nla_data(tb[NHA_GROUP]);
- for (i = 0; i < len; ++i) {
- struct nexthop *nh;
- bool is_fdb_nh;
- nh = nexthop_find_by_id(net, nhg[i].id);
- if (!nh) {
- NL_SET_ERR_MSG(extack, "Invalid nexthop id");
- return -EINVAL;
- }
- if (!valid_group_nh(nh, len, &is_fdb_nh, extack))
- return -EINVAL;
- if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack))
- return -EINVAL;
- if (!nhg_fdb && is_fdb_nh) {
- NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops");
- return -EINVAL;
- }
- }
- for (i = NHA_GROUP_TYPE + 1; i < __NHA_MAX; ++i) {
- if (!tb[i])
- continue;
- if (i == NHA_FDB)
- continue;
- NL_SET_ERR_MSG(extack,
- "No other attributes can be set in nexthop groups");
- return -EINVAL;
- }
- return 0;
- }
- static bool ipv6_good_nh(const struct fib6_nh *nh)
- {
- int state = NUD_REACHABLE;
- struct neighbour *n;
- rcu_read_lock_bh();
- n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
- if (n)
- state = n->nud_state;
- rcu_read_unlock_bh();
- return !!(state & NUD_VALID);
- }
- static bool ipv4_good_nh(const struct fib_nh *nh)
- {
- int state = NUD_REACHABLE;
- struct neighbour *n;
- rcu_read_lock_bh();
- n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
- (__force u32)nh->fib_nh_gw4);
- if (n)
- state = n->nud_state;
- rcu_read_unlock_bh();
- return !!(state & NUD_VALID);
- }
- struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
- {
- struct nexthop *rc = NULL;
- struct nh_group *nhg;
- int i;
- if (!nh->is_group)
- return nh;
- nhg = rcu_dereference(nh->nh_grp);
- for (i = 0; i < nhg->num_nh; ++i) {
- struct nh_grp_entry *nhge = &nhg->nh_entries[i];
- struct nh_info *nhi;
- if (hash > atomic_read(&nhge->upper_bound))
- continue;
- nhi = rcu_dereference(nhge->nh->nh_info);
- if (nhi->fdb_nh)
- return nhge->nh;
- /* nexthops always check if it is good and does
- * not rely on a sysctl for this behavior
- */
- switch (nhi->family) {
- case AF_INET:
- if (ipv4_good_nh(&nhi->fib_nh))
- return nhge->nh;
- break;
- case AF_INET6:
- if (ipv6_good_nh(&nhi->fib6_nh))
- return nhge->nh;
- break;
- }
- if (!rc)
- rc = nhge->nh;
- }
- return rc;
- }
- EXPORT_SYMBOL_GPL(nexthop_select_path);
- int nexthop_for_each_fib6_nh(struct nexthop *nh,
- int (*cb)(struct fib6_nh *nh, void *arg),
- void *arg)
- {
- struct nh_info *nhi;
- int err;
- if (nh->is_group) {
- struct nh_group *nhg;
- int i;
- nhg = rcu_dereference_rtnl(nh->nh_grp);
- for (i = 0; i < nhg->num_nh; i++) {
- struct nh_grp_entry *nhge = &nhg->nh_entries[i];
- nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
- err = cb(&nhi->fib6_nh, arg);
- if (err)
- return err;
- }
- } else {
- nhi = rcu_dereference_rtnl(nh->nh_info);
- err = cb(&nhi->fib6_nh, arg);
- if (err)
- return err;
- }
- return 0;
- }
- EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
- static int check_src_addr(const struct in6_addr *saddr,
- struct netlink_ext_ack *extack)
- {
- if (!ipv6_addr_any(saddr)) {
- NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
- return -EINVAL;
- }
- return 0;
- }
- int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
- struct netlink_ext_ack *extack)
- {
- struct nh_info *nhi;
- bool is_fdb_nh;
- /* fib6_src is unique to a fib6_info and limits the ability to cache
- * routes in fib6_nh within a nexthop that is potentially shared
- * across multiple fib entries. If the config wants to use source
- * routing it can not use nexthop objects. mlxsw also does not allow
- * fib6_src on routes.
- */
- if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
- return -EINVAL;
- if (nh->is_group) {
- struct nh_group *nhg;
- nhg = rtnl_dereference(nh->nh_grp);
- if (nhg->has_v4)
- goto no_v4_nh;
- is_fdb_nh = nhg->fdb_nh;
- } else {
- nhi = rtnl_dereference(nh->nh_info);
- if (nhi->family == AF_INET)
- goto no_v4_nh;
- is_fdb_nh = nhi->fdb_nh;
- }
- if (is_fdb_nh) {
- NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
- return -EINVAL;
- }
- return 0;
- no_v4_nh:
- NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
- return -EINVAL;
- }
- EXPORT_SYMBOL_GPL(fib6_check_nexthop);
- /* if existing nexthop has ipv6 routes linked to it, need
- * to verify this new spec works with ipv6
- */
- static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
- struct netlink_ext_ack *extack)
- {
- struct fib6_info *f6i;
- if (list_empty(&old->f6i_list))
- return 0;
- list_for_each_entry(f6i, &old->f6i_list, nh_list) {
- if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
- return -EINVAL;
- }
- return fib6_check_nexthop(new, NULL, extack);
- }
- static int nexthop_check_scope(struct nh_info *nhi, u8 scope,
- struct netlink_ext_ack *extack)
- {
- if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
- NL_SET_ERR_MSG(extack,
- "Route with host scope can not have a gateway");
- return -EINVAL;
- }
- if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
- NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
- return -EINVAL;
- }
- return 0;
- }
- /* Invoked by fib add code to verify nexthop by id is ok with
- * config for prefix; parts of fib_check_nh not done when nexthop
- * object is used.
- */
- int fib_check_nexthop(struct nexthop *nh, u8 scope,
- struct netlink_ext_ack *extack)
- {
- struct nh_info *nhi;
- int err = 0;
- if (nh->is_group) {
- struct nh_group *nhg;
- nhg = rtnl_dereference(nh->nh_grp);
- if (nhg->fdb_nh) {
- NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
- err = -EINVAL;
- goto out;
- }
- if (scope == RT_SCOPE_HOST) {
- NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
- err = -EINVAL;
- goto out;
- }
- /* all nexthops in a group have the same scope */
- nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info);
- err = nexthop_check_scope(nhi, scope, extack);
- } else {
- nhi = rtnl_dereference(nh->nh_info);
- if (nhi->fdb_nh) {
- NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
- err = -EINVAL;
- goto out;
- }
- err = nexthop_check_scope(nhi, scope, extack);
- }
- out:
- return err;
- }
- static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
- struct netlink_ext_ack *extack)
- {
- struct fib_info *fi;
- list_for_each_entry(fi, &old->fi_list, nh_list) {
- int err;
- err = fib_check_nexthop(new, fi->fib_scope, extack);
- if (err)
- return err;
- }
- return 0;
- }
- static void nh_group_rebalance(struct nh_group *nhg)
- {
- int total = 0;
- int w = 0;
- int i;
- for (i = 0; i < nhg->num_nh; ++i)
- total += nhg->nh_entries[i].weight;
- for (i = 0; i < nhg->num_nh; ++i) {
- struct nh_grp_entry *nhge = &nhg->nh_entries[i];
- int upper_bound;
- w += nhge->weight;
- upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
- atomic_set(&nhge->upper_bound, upper_bound);
- }
- }
- static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
- struct nl_info *nlinfo)
- {
- struct nh_grp_entry *nhges, *new_nhges;
- struct nexthop *nhp = nhge->nh_parent;
- struct nexthop *nh = nhge->nh;
- struct nh_group *nhg, *newg;
- int i, j;
- WARN_ON(!nh);
- nhg = rtnl_dereference(nhp->nh_grp);
- newg = nhg->spare;
- /* last entry, keep it visible and remove the parent */
- if (nhg->num_nh == 1) {
- remove_nexthop(net, nhp, nlinfo);
- return;
- }
- newg->has_v4 = false;
- newg->mpath = nhg->mpath;
- newg->fdb_nh = nhg->fdb_nh;
- newg->num_nh = nhg->num_nh;
- /* copy old entries to new except the one getting removed */
- nhges = nhg->nh_entries;
- new_nhges = newg->nh_entries;
- for (i = 0, j = 0; i < nhg->num_nh; ++i) {
- struct nh_info *nhi;
- /* current nexthop getting removed */
- if (nhg->nh_entries[i].nh == nh) {
- newg->num_nh--;
- continue;
- }
- nhi = rtnl_dereference(nhges[i].nh->nh_info);
- if (nhi->family == AF_INET)
- newg->has_v4 = true;
- list_del(&nhges[i].nh_list);
- new_nhges[j].nh_parent = nhges[i].nh_parent;
- new_nhges[j].nh = nhges[i].nh;
- new_nhges[j].weight = nhges[i].weight;
- list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list);
- j++;
- }
- nh_group_rebalance(newg);
- rcu_assign_pointer(nhp->nh_grp, newg);
- list_del(&nhge->nh_list);
- nexthop_put(nhge->nh);
- if (nlinfo)
- nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo);
- }
- static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
- struct nl_info *nlinfo)
- {
- struct nh_grp_entry *nhge, *tmp;
- list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list)
- remove_nh_grp_entry(net, nhge, nlinfo);
- /* make sure all see the newly published array before releasing rtnl */
- synchronize_net();
- }
- static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
- {
- struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
- int i, num_nh = nhg->num_nh;
- for (i = 0; i < num_nh; ++i) {
- struct nh_grp_entry *nhge = &nhg->nh_entries[i];
- if (WARN_ON(!nhge->nh))
- continue;
- list_del_init(&nhge->nh_list);
- }
- }
- /* not called for nexthop replace */
- static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
- {
- struct fib6_info *f6i, *tmp;
- bool do_flush = false;
- struct fib_info *fi;
- list_for_each_entry(fi, &nh->fi_list, nh_list) {
- fi->fib_flags |= RTNH_F_DEAD;
- do_flush = true;
- }
- if (do_flush)
- fib_flush(net);
- /* ip6_del_rt removes the entry from this list hence the _safe */
- list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
- /* __ip6_del_rt does a release, so do a hold here */
- fib6_info_hold(f6i);
- ipv6_stub->ip6_del_rt(net, f6i,
- !net->ipv4.sysctl_nexthop_compat_mode);
- }
- }
- static void __remove_nexthop(struct net *net, struct nexthop *nh,
- struct nl_info *nlinfo)
- {
- __remove_nexthop_fib(net, nh);
- if (nh->is_group) {
- remove_nexthop_group(nh, nlinfo);
- } else {
- struct nh_info *nhi;
- nhi = rtnl_dereference(nh->nh_info);
- if (nhi->fib_nhc.nhc_dev)
- hlist_del(&nhi->dev_hash);
- remove_nexthop_from_groups(net, nh, nlinfo);
- }
- }
- static void remove_nexthop(struct net *net, struct nexthop *nh,
- struct nl_info *nlinfo)
- {
- call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh);
- /* remove from the tree */
- rb_erase(&nh->rb_node, &net->nexthop.rb_root);
- if (nlinfo)
- nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
- __remove_nexthop(net, nh, nlinfo);
- nh_base_seq_inc(net);
- nexthop_put(nh);
- }
- /* if any FIB entries reference this nexthop, any dst entries
- * need to be regenerated
- */
- static void nh_rt_cache_flush(struct net *net, struct nexthop *nh)
- {
- struct fib6_info *f6i;
- if (!list_empty(&nh->fi_list))
- rt_cache_flush(net);
- list_for_each_entry(f6i, &nh->f6i_list, nh_list)
- ipv6_stub->fib6_update_sernum(net, f6i);
- }
- static int replace_nexthop_grp(struct net *net, struct nexthop *old,
- struct nexthop *new,
- struct netlink_ext_ack *extack)
- {
- struct nh_group *oldg, *newg;
- int i;
- if (!new->is_group) {
- NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
- return -EINVAL;
- }
- oldg = rtnl_dereference(old->nh_grp);
- newg = rtnl_dereference(new->nh_grp);
- /* update parents - used by nexthop code for cleanup */
- for (i = 0; i < newg->num_nh; i++)
- newg->nh_entries[i].nh_parent = old;
- rcu_assign_pointer(old->nh_grp, newg);
- for (i = 0; i < oldg->num_nh; i++)
- oldg->nh_entries[i].nh_parent = new;
- rcu_assign_pointer(new->nh_grp, oldg);
- return 0;
- }
- static void nh_group_v4_update(struct nh_group *nhg)
- {
- struct nh_grp_entry *nhges;
- bool has_v4 = false;
- int i;
- nhges = nhg->nh_entries;
- for (i = 0; i < nhg->num_nh; i++) {
- struct nh_info *nhi;
- nhi = rtnl_dereference(nhges[i].nh->nh_info);
- if (nhi->family == AF_INET)
- has_v4 = true;
- }
- nhg->has_v4 = has_v4;
- }
- static int replace_nexthop_single(struct net *net, struct nexthop *old,
- struct nexthop *new,
- struct netlink_ext_ack *extack)
- {
- struct nh_info *oldi, *newi;
- if (new->is_group) {
- NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
- return -EINVAL;
- }
- oldi = rtnl_dereference(old->nh_info);
- newi = rtnl_dereference(new->nh_info);
- newi->nh_parent = old;
- oldi->nh_parent = new;
- old->protocol = new->protocol;
- old->nh_flags = new->nh_flags;
- rcu_assign_pointer(old->nh_info, newi);
- rcu_assign_pointer(new->nh_info, oldi);
- /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially
- * update IPv4 indication in all the groups using the nexthop.
- */
- if (oldi->family == AF_INET && newi->family == AF_INET6) {
- struct nh_grp_entry *nhge;
- list_for_each_entry(nhge, &old->grp_list, nh_list) {
- struct nexthop *nhp = nhge->nh_parent;
- struct nh_group *nhg;
- nhg = rtnl_dereference(nhp->nh_grp);
- nh_group_v4_update(nhg);
- }
- }
- return 0;
- }
- static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
- struct nl_info *info)
- {
- struct fib6_info *f6i;
- if (!list_empty(&nh->fi_list)) {
- struct fib_info *fi;
- /* expectation is a few fib_info per nexthop and then
- * a lot of routes per fib_info. So mark the fib_info
- * and then walk the fib tables once
- */
- list_for_each_entry(fi, &nh->fi_list, nh_list)
- fi->nh_updated = true;
- fib_info_notify_update(net, info);
- list_for_each_entry(fi, &nh->fi_list, nh_list)
- fi->nh_updated = false;
- }
- list_for_each_entry(f6i, &nh->f6i_list, nh_list)
- ipv6_stub->fib6_rt_update(net, f6i, info);
- }
- /* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
- * linked to this nexthop and for all groups that the nexthop
- * is a member of
- */
- static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
- struct nl_info *info)
- {
- struct nh_grp_entry *nhge;
- __nexthop_replace_notify(net, nh, info);
- list_for_each_entry(nhge, &nh->grp_list, nh_list)
- __nexthop_replace_notify(net, nhge->nh_parent, info);
- }
- static int replace_nexthop(struct net *net, struct nexthop *old,
- struct nexthop *new, struct netlink_ext_ack *extack)
- {
- bool new_is_reject = false;
- struct nh_grp_entry *nhge;
- int err;
- /* check that existing FIB entries are ok with the
- * new nexthop definition
- */
- err = fib_check_nh_list(old, new, extack);
- if (err)
- return err;
- err = fib6_check_nh_list(old, new, extack);
- if (err)
- return err;
- if (!new->is_group) {
- struct nh_info *nhi = rtnl_dereference(new->nh_info);
- new_is_reject = nhi->reject_nh;
- }
- list_for_each_entry(nhge, &old->grp_list, nh_list) {
- /* if new nexthop is a blackhole, any groups using this
- * nexthop cannot have more than 1 path
- */
- if (new_is_reject &&
- nexthop_num_path(nhge->nh_parent) > 1) {
- NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
- return -EINVAL;
- }
- err = fib_check_nh_list(nhge->nh_parent, new, extack);
- if (err)
- return err;
- err = fib6_check_nh_list(nhge->nh_parent, new, extack);
- if (err)
- return err;
- }
- if (old->is_group)
- err = replace_nexthop_grp(net, old, new, extack);
- else
- err = replace_nexthop_single(net, old, new, extack);
- if (!err) {
- nh_rt_cache_flush(net, old);
- __remove_nexthop(net, new, NULL);
- nexthop_put(new);
- }
- return err;
- }
- /* called with rtnl_lock held */
- static int insert_nexthop(struct net *net, struct nexthop *new_nh,
- struct nh_config *cfg, struct netlink_ext_ack *extack)
- {
- struct rb_node **pp, *parent = NULL, *next;
- struct rb_root *root = &net->nexthop.rb_root;
- bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
- bool create = !!(cfg->nlflags & NLM_F_CREATE);
- u32 new_id = new_nh->id;
- int replace_notify = 0;
- int rc = -EEXIST;
- pp = &root->rb_node;
- while (1) {
- struct nexthop *nh;
- next = *pp;
- if (!next)
- break;
- parent = next;
- nh = rb_entry(parent, struct nexthop, rb_node);
- if (new_id < nh->id) {
- pp = &next->rb_left;
- } else if (new_id > nh->id) {
- pp = &next->rb_right;
- } else if (replace) {
- rc = replace_nexthop(net, nh, new_nh, extack);
- if (!rc) {
- new_nh = nh; /* send notification with old nh */
- replace_notify = 1;
- }
- goto out;
- } else {
- /* id already exists and not a replace */
- goto out;
- }
- }
- if (replace && !create) {
- NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
- rc = -ENOENT;
- goto out;
- }
- rb_link_node_rcu(&new_nh->rb_node, parent, pp);
- rb_insert_color(&new_nh->rb_node, root);
- rc = 0;
- out:
- if (!rc) {
- nh_base_seq_inc(net);
- nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
- if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode)
- nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
- }
- return rc;
- }
- /* rtnl */
- /* remove all nexthops tied to a device being deleted */
- static void nexthop_flush_dev(struct net_device *dev, unsigned long event)
- {
- unsigned int hash = nh_dev_hashfn(dev->ifindex);
- struct net *net = dev_net(dev);
- struct hlist_head *head = &net->nexthop.devhash[hash];
- struct hlist_node *n;
- struct nh_info *nhi;
- hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
- if (nhi->fib_nhc.nhc_dev != dev)
- continue;
- if (nhi->reject_nh &&
- (event == NETDEV_DOWN || event == NETDEV_CHANGE))
- continue;
- remove_nexthop(net, nhi->nh_parent, NULL);
- }
- }
- /* rtnl; called when net namespace is deleted */
- static void flush_all_nexthops(struct net *net)
- {
- struct rb_root *root = &net->nexthop.rb_root;
- struct rb_node *node;
- struct nexthop *nh;
- while ((node = rb_first(root))) {
- nh = rb_entry(node, struct nexthop, rb_node);
- remove_nexthop(net, nh, NULL);
- cond_resched();
- }
- }
- static struct nexthop *nexthop_create_group(struct net *net,
- struct nh_config *cfg)
- {
- struct nlattr *grps_attr = cfg->nh_grp;
- struct nexthop_grp *entry = nla_data(grps_attr);
- u16 num_nh = nla_len(grps_attr) / sizeof(*entry);
- struct nh_group *nhg;
- struct nexthop *nh;
- int i;
- if (WARN_ON(!num_nh))
- return ERR_PTR(-EINVAL);
- nh = nexthop_alloc();
- if (!nh)
- return ERR_PTR(-ENOMEM);
- nh->is_group = 1;
- nhg = nexthop_grp_alloc(num_nh);
- if (!nhg) {
- kfree(nh);
- return ERR_PTR(-ENOMEM);
- }
- /* spare group used for removals */
- nhg->spare = nexthop_grp_alloc(num_nh);
- if (!nhg->spare) {
- kfree(nhg);
- kfree(nh);
- return ERR_PTR(-ENOMEM);
- }
- nhg->spare->spare = nhg;
- for (i = 0; i < nhg->num_nh; ++i) {
- struct nexthop *nhe;
- struct nh_info *nhi;
- nhe = nexthop_find_by_id(net, entry[i].id);
- if (!nexthop_get(nhe))
- goto out_no_nh;
- nhi = rtnl_dereference(nhe->nh_info);
- if (nhi->family == AF_INET)
- nhg->has_v4 = true;
- nhg->nh_entries[i].nh = nhe;
- nhg->nh_entries[i].weight = entry[i].weight + 1;
- list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
- nhg->nh_entries[i].nh_parent = nh;
- }
- if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
- nhg->mpath = 1;
- nh_group_rebalance(nhg);
- }
- if (cfg->nh_fdb)
- nhg->fdb_nh = 1;
- rcu_assign_pointer(nh->nh_grp, nhg);
- return nh;
- out_no_nh:
- for (i--; i >= 0; --i) {
- list_del(&nhg->nh_entries[i].nh_list);
- nexthop_put(nhg->nh_entries[i].nh);
- }
- kfree(nhg->spare);
- kfree(nhg);
- kfree(nh);
- return ERR_PTR(-ENOENT);
- }
- static int nh_create_ipv4(struct net *net, struct nexthop *nh,
- struct nh_info *nhi, struct nh_config *cfg,
- struct netlink_ext_ack *extack)
- {
- struct fib_nh *fib_nh = &nhi->fib_nh;
- struct fib_config fib_cfg = {
- .fc_oif = cfg->nh_ifindex,
- .fc_gw4 = cfg->gw.ipv4,
- .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
- .fc_flags = cfg->nh_flags,
- .fc_nlinfo = cfg->nlinfo,
- .fc_encap = cfg->nh_encap,
- .fc_encap_type = cfg->nh_encap_type,
- };
- u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN);
- int err;
- err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
- if (err) {
- fib_nh_release(net, fib_nh);
- goto out;
- }
- if (nhi->fdb_nh)
- goto out;
- /* sets nh_dev if successful */
- err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
- if (!err) {
- nh->nh_flags = fib_nh->fib_nh_flags;
- fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
- fib_nh->fib_nh_scope);
- } else {
- fib_nh_release(net, fib_nh);
- }
- out:
- return err;
- }
- static int nh_create_ipv6(struct net *net, struct nexthop *nh,
- struct nh_info *nhi, struct nh_config *cfg,
- struct netlink_ext_ack *extack)
- {
- struct fib6_nh *fib6_nh = &nhi->fib6_nh;
- struct fib6_config fib6_cfg = {
- .fc_table = l3mdev_fib_table(cfg->dev),
- .fc_ifindex = cfg->nh_ifindex,
- .fc_gateway = cfg->gw.ipv6,
- .fc_flags = cfg->nh_flags,
- .fc_nlinfo = cfg->nlinfo,
- .fc_encap = cfg->nh_encap,
- .fc_encap_type = cfg->nh_encap_type,
- .fc_is_fdb = cfg->nh_fdb,
- };
- int err;
- if (!ipv6_addr_any(&cfg->gw.ipv6))
- fib6_cfg.fc_flags |= RTF_GATEWAY;
- /* sets nh_dev if successful */
- err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
- extack);
- if (err) {
- /* IPv6 is not enabled, don't call fib6_nh_release */
- if (err == -EAFNOSUPPORT)
- goto out;
- ipv6_stub->fib6_nh_release(fib6_nh);
- } else {
- nh->nh_flags = fib6_nh->fib_nh_flags;
- }
- out:
- return err;
- }
- static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
- struct netlink_ext_ack *extack)
- {
- struct nh_info *nhi;
- struct nexthop *nh;
- int err = 0;
- nh = nexthop_alloc();
- if (!nh)
- return ERR_PTR(-ENOMEM);
- nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
- if (!nhi) {
- kfree(nh);
- return ERR_PTR(-ENOMEM);
- }
- nh->nh_flags = cfg->nh_flags;
- nh->net = net;
- nhi->nh_parent = nh;
- nhi->family = cfg->nh_family;
- nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
- if (cfg->nh_fdb)
- nhi->fdb_nh = 1;
- if (cfg->nh_blackhole) {
- nhi->reject_nh = 1;
- cfg->nh_ifindex = net->loopback_dev->ifindex;
- }
- switch (cfg->nh_family) {
- case AF_INET:
- err = nh_create_ipv4(net, nh, nhi, cfg, extack);
- break;
- case AF_INET6:
- err = nh_create_ipv6(net, nh, nhi, cfg, extack);
- break;
- }
- if (err) {
- kfree(nhi);
- kfree(nh);
- return ERR_PTR(err);
- }
- /* add the entry to the device based hash */
- if (!nhi->fdb_nh)
- nexthop_devhash_add(net, nhi);
- rcu_assign_pointer(nh->nh_info, nhi);
- return nh;
- }
- /* called with rtnl lock held */
- static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
- struct netlink_ext_ack *extack)
- {
- struct nexthop *nh;
- int err;
- if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
- NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
- return ERR_PTR(-EINVAL);
- }
- if (!cfg->nh_id) {
- cfg->nh_id = nh_find_unused_id(net);
- if (!cfg->nh_id) {
- NL_SET_ERR_MSG(extack, "No unused id");
- return ERR_PTR(-EINVAL);
- }
- }
- if (cfg->nh_grp)
- nh = nexthop_create_group(net, cfg);
- else
- nh = nexthop_create(net, cfg, extack);
- if (IS_ERR(nh))
- return nh;
- refcount_set(&nh->refcnt, 1);
- nh->id = cfg->nh_id;
- nh->protocol = cfg->nh_protocol;
- nh->net = net;
- err = insert_nexthop(net, nh, cfg, extack);
- if (err) {
- __remove_nexthop(net, nh, NULL);
- nexthop_put(nh);
- nh = ERR_PTR(err);
- }
- return nh;
- }
- static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
- struct nlmsghdr *nlh, struct nh_config *cfg,
- struct netlink_ext_ack *extack)
- {
- struct nhmsg *nhm = nlmsg_data(nlh);
- struct nlattr *tb[NHA_MAX + 1];
- int err;
- err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
- extack);
- if (err < 0)
- return err;
- err = -EINVAL;
- if (nhm->resvd || nhm->nh_scope) {
- NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
- goto out;
- }
- if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
- NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
- goto out;
- }
- switch (nhm->nh_family) {
- case AF_INET:
- case AF_INET6:
- break;
- case AF_UNSPEC:
- if (tb[NHA_GROUP])
- break;
- fallthrough;
- default:
- NL_SET_ERR_MSG(extack, "Invalid address family");
- goto out;
- }
- if (tb[NHA_GROUPS] || tb[NHA_MASTER]) {
- NL_SET_ERR_MSG(extack, "Invalid attributes in request");
- goto out;
- }
- memset(cfg, 0, sizeof(*cfg));
- cfg->nlflags = nlh->nlmsg_flags;
- cfg->nlinfo.portid = NETLINK_CB(skb).portid;
- cfg->nlinfo.nlh = nlh;
- cfg->nlinfo.nl_net = net;
- cfg->nh_family = nhm->nh_family;
- cfg->nh_protocol = nhm->nh_protocol;
- cfg->nh_flags = nhm->nh_flags;
- if (tb[NHA_ID])
- cfg->nh_id = nla_get_u32(tb[NHA_ID]);
- if (tb[NHA_FDB]) {
- if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] ||
- tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) {
- NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole");
- goto out;
- }
- if (nhm->nh_flags) {
- NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header");
- goto out;
- }
- cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]);
- }
- if (tb[NHA_GROUP]) {
- if (nhm->nh_family != AF_UNSPEC) {
- NL_SET_ERR_MSG(extack, "Invalid family for group");
- goto out;
- }
- cfg->nh_grp = tb[NHA_GROUP];
- cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
- if (tb[NHA_GROUP_TYPE])
- cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
- if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
- NL_SET_ERR_MSG(extack, "Invalid group type");
- goto out;
- }
- err = nh_check_attr_group(net, tb, extack);
- /* no other attributes should be set */
- goto out;
- }
- if (tb[NHA_BLACKHOLE]) {
- if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
- tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) {
- NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb");
- goto out;
- }
- cfg->nh_blackhole = 1;
- err = 0;
- goto out;
- }
- if (!cfg->nh_fdb && !tb[NHA_OIF]) {
- NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops");
- goto out;
- }
- if (!cfg->nh_fdb && tb[NHA_OIF]) {
- cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
- if (cfg->nh_ifindex)
- cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
- if (!cfg->dev) {
- NL_SET_ERR_MSG(extack, "Invalid device index");
- goto out;
- } else if (!(cfg->dev->flags & IFF_UP)) {
- NL_SET_ERR_MSG(extack, "Nexthop device is not up");
- err = -ENETDOWN;
- goto out;
- } else if (!netif_carrier_ok(cfg->dev)) {
- NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
- err = -ENETDOWN;
- goto out;
- }
- }
- err = -EINVAL;
- if (tb[NHA_GATEWAY]) {
- struct nlattr *gwa = tb[NHA_GATEWAY];
- switch (cfg->nh_family) {
- case AF_INET:
- if (nla_len(gwa) != sizeof(u32)) {
- NL_SET_ERR_MSG(extack, "Invalid gateway");
- goto out;
- }
- cfg->gw.ipv4 = nla_get_be32(gwa);
- break;
- case AF_INET6:
- if (nla_len(gwa) != sizeof(struct in6_addr)) {
- NL_SET_ERR_MSG(extack, "Invalid gateway");
- goto out;
- }
- cfg->gw.ipv6 = nla_get_in6_addr(gwa);
- break;
- default:
- NL_SET_ERR_MSG(extack,
- "Unknown address family for gateway");
- goto out;
- }
- } else {
- /* device only nexthop (no gateway) */
- if (cfg->nh_flags & RTNH_F_ONLINK) {
- NL_SET_ERR_MSG(extack,
- "ONLINK flag can not be set for nexthop without a gateway");
- goto out;
- }
- }
- if (tb[NHA_ENCAP]) {
- cfg->nh_encap = tb[NHA_ENCAP];
- if (!tb[NHA_ENCAP_TYPE]) {
- NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
- goto out;
- }
- cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
- err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
- if (err < 0)
- goto out;
- } else if (tb[NHA_ENCAP_TYPE]) {
- NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
- goto out;
- }
- err = 0;
- out:
- return err;
- }
- /* rtnl */
- static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
- struct netlink_ext_ack *extack)
- {
- struct net *net = sock_net(skb->sk);
- struct nh_config cfg;
- struct nexthop *nh;
- int err;
- err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
- if (!err) {
- nh = nexthop_add(net, &cfg, extack);
- if (IS_ERR(nh))
- err = PTR_ERR(nh);
- }
- return err;
- }
- static int nh_valid_get_del_req(struct nlmsghdr *nlh, u32 *id,
- struct netlink_ext_ack *extack)
- {
- struct nhmsg *nhm = nlmsg_data(nlh);
- struct nlattr *tb[NHA_MAX + 1];
- int err, i;
- err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
- extack);
- if (err < 0)
- return err;
- err = -EINVAL;
- for (i = 0; i < __NHA_MAX; ++i) {
- if (!tb[i])
- continue;
- switch (i) {
- case NHA_ID:
- break;
- default:
- NL_SET_ERR_MSG_ATTR(extack, tb[i],
- "Unexpected attribute in request");
- goto out;
- }
- }
- if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
- NL_SET_ERR_MSG(extack, "Invalid values in header");
- goto out;
- }
- if (!tb[NHA_ID]) {
- NL_SET_ERR_MSG(extack, "Nexthop id is missing");
- goto out;
- }
- *id = nla_get_u32(tb[NHA_ID]);
- if (!(*id))
- NL_SET_ERR_MSG(extack, "Invalid nexthop id");
- else
- err = 0;
- out:
- return err;
- }
- /* rtnl */
- static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
- struct netlink_ext_ack *extack)
- {
- struct net *net = sock_net(skb->sk);
- struct nl_info nlinfo = {
- .nlh = nlh,
- .nl_net = net,
- .portid = NETLINK_CB(skb).portid,
- };
- struct nexthop *nh;
- int err;
- u32 id;
- err = nh_valid_get_del_req(nlh, &id, extack);
- if (err)
- return err;
- nh = nexthop_find_by_id(net, id);
- if (!nh)
- return -ENOENT;
- remove_nexthop(net, nh, &nlinfo);
- return 0;
- }
- /* rtnl */
- static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
- struct netlink_ext_ack *extack)
- {
- struct net *net = sock_net(in_skb->sk);
- struct sk_buff *skb = NULL;
- struct nexthop *nh;
- int err;
- u32 id;
- err = nh_valid_get_del_req(nlh, &id, extack);
- if (err)
- return err;
- err = -ENOBUFS;
- skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
- if (!skb)
- goto out;
- err = -ENOENT;
- nh = nexthop_find_by_id(net, id);
- if (!nh)
- goto errout_free;
- err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
- nlh->nlmsg_seq, 0);
- if (err < 0) {
- WARN_ON(err == -EMSGSIZE);
- goto errout_free;
- }
- err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
- out:
- return err;
- errout_free:
- kfree_skb(skb);
- goto out;
- }
- static bool nh_dump_filtered(struct nexthop *nh, int dev_idx, int master_idx,
- bool group_filter, u8 family)
- {
- const struct net_device *dev;
- const struct nh_info *nhi;
- if (group_filter && !nh->is_group)
- return true;
- if (!dev_idx && !master_idx && !family)
- return false;
- if (nh->is_group)
- return true;
- nhi = rtnl_dereference(nh->nh_info);
- if (family && nhi->family != family)
- return true;
- dev = nhi->fib_nhc.nhc_dev;
- if (dev_idx && (!dev || dev->ifindex != dev_idx))
- return true;
- if (master_idx) {
- struct net_device *master;
- if (!dev)
- return true;
- master = netdev_master_upper_dev_get((struct net_device *)dev);
- if (!master || master->ifindex != master_idx)
- return true;
- }
- return false;
- }
- static int nh_valid_dump_req(const struct nlmsghdr *nlh, int *dev_idx,
- int *master_idx, bool *group_filter,
- bool *fdb_filter, struct netlink_callback *cb)
- {
- struct netlink_ext_ack *extack = cb->extack;
- struct nlattr *tb[NHA_MAX + 1];
- struct nhmsg *nhm;
- int err, i;
- u32 idx;
- err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
- NULL);
- if (err < 0)
- return err;
- for (i = 0; i <= NHA_MAX; ++i) {
- if (!tb[i])
- continue;
- switch (i) {
- case NHA_OIF:
- idx = nla_get_u32(tb[i]);
- if (idx > INT_MAX) {
- NL_SET_ERR_MSG(extack, "Invalid device index");
- return -EINVAL;
- }
- *dev_idx = idx;
- break;
- case NHA_MASTER:
- idx = nla_get_u32(tb[i]);
- if (idx > INT_MAX) {
- NL_SET_ERR_MSG(extack, "Invalid master device index");
- return -EINVAL;
- }
- *master_idx = idx;
- break;
- case NHA_GROUPS:
- *group_filter = true;
- break;
- case NHA_FDB:
- *fdb_filter = true;
- break;
- default:
- NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
- return -EINVAL;
- }
- }
- nhm = nlmsg_data(nlh);
- if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
- NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
- return -EINVAL;
- }
- return 0;
- }
- /* rtnl */
- static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
- {
- bool group_filter = false, fdb_filter = false;
- struct nhmsg *nhm = nlmsg_data(cb->nlh);
- int dev_filter_idx = 0, master_idx = 0;
- struct net *net = sock_net(skb->sk);
- struct rb_root *root = &net->nexthop.rb_root;
- struct rb_node *node;
- int idx = 0, s_idx;
- int err;
- err = nh_valid_dump_req(cb->nlh, &dev_filter_idx, &master_idx,
- &group_filter, &fdb_filter, cb);
- if (err < 0)
- return err;
- s_idx = cb->args[0];
- for (node = rb_first(root); node; node = rb_next(node)) {
- struct nexthop *nh;
- if (idx < s_idx)
- goto cont;
- nh = rb_entry(node, struct nexthop, rb_node);
- if (nh_dump_filtered(nh, dev_filter_idx, master_idx,
- group_filter, nhm->nh_family))
- goto cont;
- err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
- NETLINK_CB(cb->skb).portid,
- cb->nlh->nlmsg_seq, NLM_F_MULTI);
- if (err < 0) {
- if (likely(skb->len))
- goto out;
- goto out_err;
- }
- cont:
- idx++;
- }
- out:
- err = skb->len;
- out_err:
- cb->args[0] = idx;
- cb->seq = net->nexthop.seq;
- nl_dump_check_consistent(cb, nlmsg_hdr(skb));
- return err;
- }
- static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
- {
- unsigned int hash = nh_dev_hashfn(dev->ifindex);
- struct net *net = dev_net(dev);
- struct hlist_head *head = &net->nexthop.devhash[hash];
- struct hlist_node *n;
- struct nh_info *nhi;
- hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
- if (nhi->fib_nhc.nhc_dev == dev) {
- if (nhi->family == AF_INET)
- fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
- orig_mtu);
- }
- }
- }
- /* rtnl */
- static int nh_netdev_event(struct notifier_block *this,
- unsigned long event, void *ptr)
- {
- struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- struct netdev_notifier_info_ext *info_ext;
- switch (event) {
- case NETDEV_DOWN:
- case NETDEV_UNREGISTER:
- nexthop_flush_dev(dev, event);
- break;
- case NETDEV_CHANGE:
- if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
- nexthop_flush_dev(dev, event);
- break;
- case NETDEV_CHANGEMTU:
- info_ext = ptr;
- nexthop_sync_mtu(dev, info_ext->ext.mtu);
- rt_cache_flush(dev_net(dev));
- break;
- }
- return NOTIFY_DONE;
- }
- static struct notifier_block nh_netdev_notifier = {
- .notifier_call = nh_netdev_event,
- };
- int register_nexthop_notifier(struct net *net, struct notifier_block *nb)
- {
- return blocking_notifier_chain_register(&net->nexthop.notifier_chain,
- nb);
- }
- EXPORT_SYMBOL(register_nexthop_notifier);
- int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb)
- {
- return blocking_notifier_chain_unregister(&net->nexthop.notifier_chain,
- nb);
- }
- EXPORT_SYMBOL(unregister_nexthop_notifier);
- static void __net_exit nexthop_net_exit(struct net *net)
- {
- rtnl_lock();
- flush_all_nexthops(net);
- rtnl_unlock();
- kfree(net->nexthop.devhash);
- }
- static int __net_init nexthop_net_init(struct net *net)
- {
- size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
- net->nexthop.rb_root = RB_ROOT;
- net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
- if (!net->nexthop.devhash)
- return -ENOMEM;
- BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain);
- return 0;
- }
- static struct pernet_operations nexthop_net_ops = {
- .init = nexthop_net_init,
- .exit = nexthop_net_exit,
- };
- static int __init nexthop_init(void)
- {
- register_pernet_subsys(&nexthop_net_ops);
- register_netdevice_notifier(&nh_netdev_notifier);
- rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
- rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
- rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
- rtm_dump_nexthop, 0);
- rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
- rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
- rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
- rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
- return 0;
- }
- subsys_initcall(nexthop_init);
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