From 187d4c6b97967b8d023ccb981742f8605a1b1cb7 Mon Sep 17 00:00:00 2001 From: Petr Machata Date: Thu, 11 Mar 2021 19:03:23 +0100 Subject: [PATCH] nexthop: Add netlink handlers for bucket get Allow getting (but not setting) individual buckets to inspect the next hop mapped therein, idle time, and flags. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv4/nexthop.c | 110 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 109 insertions(+), 1 deletion(-) diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c index ed2745708f9d..3d602ef6f2c1 100644 --- a/net/ipv4/nexthop.c +++ b/net/ipv4/nexthop.c @@ -66,6 +66,15 @@ static const struct nla_policy rtm_nh_res_bucket_policy_dump[] = { [NHA_RES_BUCKET_NH_ID] = { .type = NLA_U32 }, }; +static const struct nla_policy rtm_nh_policy_get_bucket[] = { + [NHA_ID] = { .type = NLA_U32 }, + [NHA_RES_BUCKET] = { .type = NLA_NESTED }, +}; + +static const struct nla_policy rtm_nh_res_bucket_policy_get[] = { + [NHA_RES_BUCKET_INDEX] = { .type = NLA_U16 }, +}; + static bool nexthop_notifiers_is_empty(struct net *net) { return !net->nexthop.notifier_chain.head; @@ -3381,6 +3390,105 @@ out_err: return err; } +static int nh_valid_get_bucket_req_res_bucket(struct nlattr *res, + u16 *bucket_index, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_get)]; + int err; + + err = nla_parse_nested(tb, ARRAY_SIZE(rtm_nh_res_bucket_policy_get) - 1, + res, rtm_nh_res_bucket_policy_get, extack); + if (err < 0) + return err; + + if (!tb[NHA_RES_BUCKET_INDEX]) { + NL_SET_ERR_MSG(extack, "Bucket index is missing"); + return -EINVAL; + } + + *bucket_index = nla_get_u16(tb[NHA_RES_BUCKET_INDEX]); + return 0; +} + +static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh, + u32 *id, u16 *bucket_index, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get_bucket)]; + int err; + + err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, + ARRAY_SIZE(rtm_nh_policy_get_bucket) - 1, + rtm_nh_policy_get_bucket, extack); + if (err < 0) + return err; + + err = __nh_valid_get_del_req(nlh, tb, id, extack); + if (err) + return err; + + if (!tb[NHA_RES_BUCKET]) { + NL_SET_ERR_MSG(extack, "Bucket information is missing"); + return -EINVAL; + } + + err = nh_valid_get_bucket_req_res_bucket(tb[NHA_RES_BUCKET], + bucket_index, extack); + if (err) + return err; + + return 0; +} + +/* rtnl */ +static int rtm_get_nexthop_bucket(struct sk_buff *in_skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(in_skb->sk); + struct nh_res_table *res_table; + struct sk_buff *skb = NULL; + struct nh_group *nhg; + struct nexthop *nh; + u16 bucket_index; + int err; + u32 id; + + err = nh_valid_get_bucket_req(nlh, &id, &bucket_index, extack); + if (err) + return err; + + nh = nexthop_find_group_resilient(net, id, extack); + if (IS_ERR(nh)) + return PTR_ERR(nh); + + nhg = rtnl_dereference(nh->nh_grp); + res_table = rtnl_dereference(nhg->res_table); + if (bucket_index >= res_table->num_nh_buckets) { + NL_SET_ERR_MSG(extack, "Bucket index out of bounds"); + return -ENOENT; + } + + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); + if (!skb) + return -ENOBUFS; + + err = nh_fill_res_bucket(skb, nh, &res_table->nh_buckets[bucket_index], + bucket_index, RTM_NEWNEXTHOPBUCKET, + NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, + 0, extack); + if (err < 0) { + WARN_ON(err == -EMSGSIZE); + goto errout_free; + } + + return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); + +errout_free: + kfree_skb(skb); + return err; +} + static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu) { unsigned int hash = nh_dev_hashfn(dev->ifindex); @@ -3604,7 +3712,7 @@ static int __init nexthop_init(void) rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0); rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0); - rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, NULL, + rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, rtm_get_nexthop_bucket, rtm_dump_nexthop_bucket, 0); return 0; -- 2.20.1