diff options
Diffstat (limited to '')
| -rw-r--r-- | net/ipv4/nexthop.c | 2053 |
1 files changed, 2053 insertions, 0 deletions
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c new file mode 100644 index 000000000..7a0102a4b --- /dev/null +++ b/net/ipv4/nexthop.c @@ -0,0 +1,2053 @@ +// 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, + !READ_ONCE(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 nexthop *replaced_nh) +{ + struct fib6_info *f6i; + struct nh_group *nhg; + int i; + + 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); + + /* if an IPv6 group was replaced, we have to release all old + * dsts to make sure all refcounts are released + */ + if (!replaced_nh->is_group) + return; + + /* new dsts must use only the new nexthop group */ + synchronize_net(); + + nhg = rtnl_dereference(replaced_nh->nh_grp); + for (i = 0; i < nhg->num_nh; i++) { + struct nh_grp_entry *nhge = &nhg->nh_entries[i]; + struct nh_info *nhi = rtnl_dereference(nhge->nh->nh_info); + + if (nhi->family == AF_INET6) + ipv6_stub->fib6_nh_release_dsts(&nhi->fib6_nh); + } +} + +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, new); + + __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 && + READ_ONCE(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 ? 0 : fib_nh->fib_nh_scope - 1); + } 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); |