| // 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 (tb[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_rcu(); |
| } |
| |
| 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 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); |
| 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 >= 0; --i) |
| 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_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_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_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_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); |
| 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, |
| }; |
| |
| 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); |