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-rw-r--r--net/ipv4/nexthop.c1828
1 files changed, 1828 insertions, 0 deletions
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
new file mode 100644
index 000000000000..5fe5a3981d43
--- /dev/null
+++ b/net/ipv4/nexthop.c
@@ -0,0 +1,1828 @@
+// 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_UNSPEC] = { .strict_start_type = NHA_UNSPEC + 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 },
+};
+
+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)
+ WARN_ON(nhg->nh_entries[i].nh);
+
+ 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);
+ }
+ return nh;
+}
+
+static struct nh_group *nexthop_grp_alloc(u16 num_nh)
+{
+ size_t sz = offsetof(struct nexthop, nh_grp)
+ + sizeof(struct nh_group)
+ + sizeof(struct nh_grp_entry) * num_nh;
+ struct nh_group *nhg;
+
+ nhg = kzalloc(sz, 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 (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 {
+ 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_u32(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:
+ 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 = 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,
+ 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;
+ }
+ } 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;
+ }
+ }
+
+ return true;
+}
+
+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]);
+ struct nexthop_grp *nhg;
+ unsigned int i, j;
+
+ if (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;
+ }
+ }
+ }
+
+ nhg = nla_data(tb[NHA_GROUP]);
+ for (i = 0; i < len; ++i) {
+ struct nexthop *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, extack))
+ return -EINVAL;
+ }
+ for (i = NHA_GROUP + 1; i < __NHA_MAX; ++i) {
+ if (!tb[i])
+ 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;
+
+ /* nexthops always check if it is good and does
+ * not rely on a sysctl for this behavior
+ */
+ nhi = rcu_dereference(nhge->nh->nh_info);
+ 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;
+
+ /* 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;
+ } else {
+ nhi = rtnl_dereference(nh->nh_info);
+ if (nhi->family == AF_INET)
+ goto no_v4_nh;
+ }
+
+ 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 nexthop *nh, u8 scope,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_info *nhi;
+
+ nhi = rtnl_dereference(nh->nh_info);
+ 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)
+{
+ int err = 0;
+
+ if (nh->is_group) {
+ struct nh_group *nhg;
+
+ if (scope == RT_SCOPE_HOST) {
+ NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
+ err = -EINVAL;
+ goto out;
+ }
+
+ nhg = rtnl_dereference(nh->nh_grp);
+ /* all nexthops in a group have the same scope */
+ err = nexthop_check_scope(nhg->nh_entries[0].nh, scope, extack);
+ } else {
+ err = nexthop_check_scope(nh, 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 nh_grp_entry *nhge,
+ struct nh_group *nhg,
+ struct nl_info *nlinfo)
+{
+ struct nexthop *nh = nhge->nh;
+ struct nh_grp_entry *nhges;
+ bool found = false;
+ int i;
+
+ WARN_ON(!nh);
+
+ nhges = nhg->nh_entries;
+ for (i = 0; i < nhg->num_nh; ++i) {
+ if (found) {
+ nhges[i-1].nh = nhges[i].nh;
+ nhges[i-1].weight = nhges[i].weight;
+ list_del(&nhges[i].nh_list);
+ list_add(&nhges[i-1].nh_list, &nhges[i-1].nh->grp_list);
+ } else if (nhg->nh_entries[i].nh == nh) {
+ found = true;
+ }
+ }
+
+ if (WARN_ON(!found))
+ return;
+
+ nhg->num_nh--;
+ nhg->nh_entries[nhg->num_nh].nh = NULL;
+
+ nh_group_rebalance(nhg);
+
+ nexthop_put(nh);
+
+ if (nlinfo)
+ nexthop_notify(RTM_NEWNEXTHOP, nhge->nh_parent, 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) {
+ struct nh_group *nhg;
+
+ list_del(&nhge->nh_list);
+ nhg = rtnl_dereference(nhge->nh_parent->nh_grp);
+ remove_nh_grp_entry(nhge, nhg, nlinfo);
+
+ /* if this group has no more entries then remove it */
+ if (!nhg->num_nh)
+ remove_nexthop(net, nhge->nh_parent, nlinfo);
+ }
+}
+
+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(&nhge->nh_list);
+ nexthop_put(nhge->nh);
+ nhge->nh = NULL;
+ nhg->num_nh--;
+ }
+}
+
+/* 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);
+ }
+}
+
+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)
+{
+ /* 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 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);
+
+ 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 = rtnl_dereference(*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)
+ 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 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;
+
+ 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);
+ struct nh_group *nhg;
+ struct nexthop *nh;
+ int i;
+
+ nh = nexthop_alloc();
+ if (!nh)
+ return ERR_PTR(-ENOMEM);
+
+ nh->is_group = 1;
+
+ nhg = nexthop_grp_alloc(nla_len(grps_attr) / sizeof(*entry));
+ if (!nhg) {
+ kfree(nh);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ 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);
+ }
+
+ rcu_assign_pointer(nh->nh_grp, nhg);
+
+ return nh;
+
+out_no_nh:
+ for (; i >= 0; --i)
+ nexthop_put(nhg->nh_entries[i].nh);
+
+ 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_encap = cfg->nh_encap,
+ .fc_encap_type = cfg->nh_encap_type,
+ };
+ u32 tb_id = l3mdev_fib_table(cfg->dev);
+ int err = -EINVAL;
+
+ err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
+ if (err) {
+ fib_nh_release(net, fib_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_encap = cfg->nh_encap,
+ .fc_encap_type = cfg->nh_encap_type,
+ };
+ 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_stub->fib6_nh_release(fib6_nh);
+ else
+ nh->nh_flags = fib6_nh->fib_nh_flags;
+
+ 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_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 */
+ 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_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]) {
+ NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway or oif");
+ goto out;
+ }
+
+ cfg->nh_blackhole = 1;
+ err = 0;
+ goto out;
+ }
+
+ if (!tb[NHA_OIF]) {
+ NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole nexthops");
+ goto out;
+ }
+
+ 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,
+ 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;
+ 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)
+{
+ 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;
+ bool group_filter = false;
+ 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, 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);
+ break;
+ case NETDEV_CHANGE:
+ if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
+ nexthop_flush_dev(dev);
+ 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,
+};
+
+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;
+
+ 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);