// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2017 Nicira, Inc. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/if.h> #include <linux/skbuff.h> #include <linux/ip.h> #include <linux/kernel.h> #include <linux/openvswitch.h> #include <linux/netlink.h> #include <linux/rculist.h> #include <net/netlink.h> #include <net/genetlink.h> #include "datapath.h" #include "meter.h" #define METER_HASH_BUCKETS 1024 static const struct nla_policy meter_policy[OVS_METER_ATTR_MAX + 1] = { [OVS_METER_ATTR_ID] = { .type = NLA_U32, }, [OVS_METER_ATTR_KBPS] = { .type = NLA_FLAG }, [OVS_METER_ATTR_STATS] = { .len = sizeof(struct ovs_flow_stats) }, [OVS_METER_ATTR_BANDS] = { .type = NLA_NESTED }, [OVS_METER_ATTR_USED] = { .type = NLA_U64 }, [OVS_METER_ATTR_CLEAR] = { .type = NLA_FLAG }, [OVS_METER_ATTR_MAX_METERS] = { .type = NLA_U32 }, [OVS_METER_ATTR_MAX_BANDS] = { .type = NLA_U32 }, }; static const struct nla_policy band_policy[OVS_BAND_ATTR_MAX + 1] = { [OVS_BAND_ATTR_TYPE] = { .type = NLA_U32, }, [OVS_BAND_ATTR_RATE] = { .type = NLA_U32, }, [OVS_BAND_ATTR_BURST] = { .type = NLA_U32, }, [OVS_BAND_ATTR_STATS] = { .len = sizeof(struct ovs_flow_stats) }, }; static void ovs_meter_free(struct dp_meter *meter) { if (!meter) return; kfree_rcu(meter, rcu); } static struct hlist_head *meter_hash_bucket(const struct datapath *dp, u32 meter_id) { return &dp->meters[meter_id & (METER_HASH_BUCKETS - 1)]; } /* Call with ovs_mutex or RCU read lock. */ static struct dp_meter *lookup_meter(const struct datapath *dp, u32 meter_id) { struct dp_meter *meter; struct hlist_head *head; head = meter_hash_bucket(dp, meter_id); hlist_for_each_entry_rcu(meter, head, dp_hash_node, lockdep_ovsl_is_held()) { if (meter->id == meter_id) return meter; } return NULL; } static void attach_meter(struct datapath *dp, struct dp_meter *meter) { struct hlist_head *head = meter_hash_bucket(dp, meter->id); hlist_add_head_rcu(&meter->dp_hash_node, head); } static void detach_meter(struct dp_meter *meter) { ASSERT_OVSL(); if (meter) hlist_del_rcu(&meter->dp_hash_node); } static struct sk_buff * ovs_meter_cmd_reply_start(struct genl_info *info, u8 cmd, struct ovs_header **ovs_reply_header) { struct sk_buff *skb; struct ovs_header *ovs_header = info->userhdr; skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); if (!skb) return ERR_PTR(-ENOMEM); *ovs_reply_header = genlmsg_put(skb, info->snd_portid, info->snd_seq, &dp_meter_genl_family, 0, cmd); if (!*ovs_reply_header) { nlmsg_free(skb); return ERR_PTR(-EMSGSIZE); } (*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex; return skb; } static int ovs_meter_cmd_reply_stats(struct sk_buff *reply, u32 meter_id, struct dp_meter *meter) { struct nlattr *nla; struct dp_meter_band *band; u16 i; if (nla_put_u32(reply, OVS_METER_ATTR_ID, meter_id)) goto error; if (!meter) return 0; if (nla_put(reply, OVS_METER_ATTR_STATS, sizeof(struct ovs_flow_stats), &meter->stats) || nla_put_u64_64bit(reply, OVS_METER_ATTR_USED, meter->used, OVS_METER_ATTR_PAD)) goto error; nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS); if (!nla) goto error; band = meter->bands; for (i = 0; i < meter->n_bands; ++i, ++band) { struct nlattr *band_nla; band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC); if (!band_nla || nla_put(reply, OVS_BAND_ATTR_STATS, sizeof(struct ovs_flow_stats), &band->stats)) goto error; nla_nest_end(reply, band_nla); } nla_nest_end(reply, nla); return 0; error: return -EMSGSIZE; } static int ovs_meter_cmd_features(struct sk_buff *skb, struct genl_info *info) { struct sk_buff *reply; struct ovs_header *ovs_reply_header; struct nlattr *nla, *band_nla; int err; reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_FEATURES, &ovs_reply_header); if (IS_ERR(reply)) return PTR_ERR(reply); if (nla_put_u32(reply, OVS_METER_ATTR_MAX_METERS, U32_MAX) || nla_put_u32(reply, OVS_METER_ATTR_MAX_BANDS, DP_MAX_BANDS)) goto nla_put_failure; nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS); if (!nla) goto nla_put_failure; band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC); if (!band_nla) goto nla_put_failure; /* Currently only DROP band type is supported. */ if (nla_put_u32(reply, OVS_BAND_ATTR_TYPE, OVS_METER_BAND_TYPE_DROP)) goto nla_put_failure; nla_nest_end(reply, band_nla); nla_nest_end(reply, nla); genlmsg_end(reply, ovs_reply_header); return genlmsg_reply(reply, info); nla_put_failure: nlmsg_free(reply); err = -EMSGSIZE; return err; } static struct dp_meter *dp_meter_create(struct nlattr **a) { struct nlattr *nla; int rem; u16 n_bands = 0; struct dp_meter *meter; struct dp_meter_band *band; int err; /* Validate attributes, count the bands. */ if (!a[OVS_METER_ATTR_BANDS]) return ERR_PTR(-EINVAL); nla_for_each_nested(nla, a[OVS_METER_ATTR_BANDS], rem) if (++n_bands > DP_MAX_BANDS) return ERR_PTR(-EINVAL); /* Allocate and set up the meter before locking anything. */ meter = kzalloc(struct_size(meter, bands, n_bands), GFP_KERNEL); if (!meter) return ERR_PTR(-ENOMEM); meter->id = nla_get_u32(a[OVS_METER_ATTR_ID]); meter->used = div_u64(ktime_get_ns(), 1000 * 1000); meter->kbps = a[OVS_METER_ATTR_KBPS] ? 1 : 0; meter->keep_stats = !a[OVS_METER_ATTR_CLEAR]; spin_lock_init(&meter->lock); if (meter->keep_stats && a[OVS_METER_ATTR_STATS]) { meter->stats = *(struct ovs_flow_stats *) nla_data(a[OVS_METER_ATTR_STATS]); } meter->n_bands = n_bands; /* Set up meter bands. */ band = meter->bands; nla_for_each_nested(nla, a[OVS_METER_ATTR_BANDS], rem) { struct nlattr *attr[OVS_BAND_ATTR_MAX + 1]; u32 band_max_delta_t; err = nla_parse_deprecated((struct nlattr **)&attr, OVS_BAND_ATTR_MAX, nla_data(nla), nla_len(nla), band_policy, NULL); if (err) goto exit_free_meter; if (!attr[OVS_BAND_ATTR_TYPE] || !attr[OVS_BAND_ATTR_RATE] || !attr[OVS_BAND_ATTR_BURST]) { err = -EINVAL; goto exit_free_meter; } band->type = nla_get_u32(attr[OVS_BAND_ATTR_TYPE]); band->rate = nla_get_u32(attr[OVS_BAND_ATTR_RATE]); if (band->rate == 0) { err = -EINVAL; goto exit_free_meter; } band->burst_size = nla_get_u32(attr[OVS_BAND_ATTR_BURST]); /* Figure out max delta_t that is enough to fill any bucket. * Keep max_delta_t size to the bucket units: * pkts => 1/1000 packets, kilobits => bits. * * Start with a full bucket. */ band->bucket = (band->burst_size + band->rate) * 1000; band_max_delta_t = band->bucket / band->rate; if (band_max_delta_t > meter->max_delta_t) meter->max_delta_t = band_max_delta_t; band++; } return meter; exit_free_meter: kfree(meter); return ERR_PTR(err); } static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info) { struct nlattr **a = info->attrs; struct dp_meter *meter, *old_meter; struct sk_buff *reply; struct ovs_header *ovs_reply_header; struct ovs_header *ovs_header = info->userhdr; struct datapath *dp; int err; u32 meter_id; bool failed; if (!a[OVS_METER_ATTR_ID]) { return -ENODEV; } meter = dp_meter_create(a); if (IS_ERR_OR_NULL(meter)) return PTR_ERR(meter); reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_SET, &ovs_reply_header); if (IS_ERR(reply)) { err = PTR_ERR(reply); goto exit_free_meter; } ovs_lock(); dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex); if (!dp) { err = -ENODEV; goto exit_unlock; } meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]); /* Cannot fail after this. */ old_meter = lookup_meter(dp, meter_id); detach_meter(old_meter); attach_meter(dp, meter); ovs_unlock(); /* Build response with the meter_id and stats from * the old meter, if any. */ failed = nla_put_u32(reply, OVS_METER_ATTR_ID, meter_id); WARN_ON(failed); if (old_meter) { spin_lock_bh(&old_meter->lock); if (old_meter->keep_stats) { err = ovs_meter_cmd_reply_stats(reply, meter_id, old_meter); WARN_ON(err); } spin_unlock_bh(&old_meter->lock); ovs_meter_free(old_meter); } genlmsg_end(reply, ovs_reply_header); return genlmsg_reply(reply, info); exit_unlock: ovs_unlock(); nlmsg_free(reply); exit_free_meter: kfree(meter); return err; } static int ovs_meter_cmd_get(struct sk_buff *skb, struct genl_info *info) { struct nlattr **a = info->attrs; u32 meter_id; struct ovs_header *ovs_header = info->userhdr; struct ovs_header *ovs_reply_header; struct datapath *dp; int err; struct sk_buff *reply; struct dp_meter *meter; if (!a[OVS_METER_ATTR_ID]) return -EINVAL; meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]); reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_GET, &ovs_reply_header); if (IS_ERR(reply)) return PTR_ERR(reply); ovs_lock(); dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex); if (!dp) { err = -ENODEV; goto exit_unlock; } /* Locate meter, copy stats. */ meter = lookup_meter(dp, meter_id); if (!meter) { err = -ENOENT; goto exit_unlock; } spin_lock_bh(&meter->lock); err = ovs_meter_cmd_reply_stats(reply, meter_id, meter); spin_unlock_bh(&meter->lock); if (err) goto exit_unlock; ovs_unlock(); genlmsg_end(reply, ovs_reply_header); return genlmsg_reply(reply, info); exit_unlock: ovs_unlock(); nlmsg_free(reply); return err; } static int ovs_meter_cmd_del(struct sk_buff *skb, struct genl_info *info) { struct nlattr **a = info->attrs; u32 meter_id; struct ovs_header *ovs_header = info->userhdr; struct ovs_header *ovs_reply_header; struct datapath *dp; int err; struct sk_buff *reply; struct dp_meter *old_meter; if (!a[OVS_METER_ATTR_ID]) return -EINVAL; meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]); reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_DEL, &ovs_reply_header); if (IS_ERR(reply)) return PTR_ERR(reply); ovs_lock(); dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex); if (!dp) { err = -ENODEV; goto exit_unlock; } old_meter = lookup_meter(dp, meter_id); if (old_meter) { spin_lock_bh(&old_meter->lock); err = ovs_meter_cmd_reply_stats(reply, meter_id, old_meter); WARN_ON(err); spin_unlock_bh(&old_meter->lock); detach_meter(old_meter); } ovs_unlock(); ovs_meter_free(old_meter); genlmsg_end(reply, ovs_reply_header); return genlmsg_reply(reply, info); exit_unlock: ovs_unlock(); nlmsg_free(reply); return err; } /* Meter action execution. * * Return true 'meter_id' drop band is triggered. The 'skb' should be * dropped by the caller'. */ bool ovs_meter_execute(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, u32 meter_id) { struct dp_meter *meter; struct dp_meter_band *band; long long int now_ms = div_u64(ktime_get_ns(), 1000 * 1000); long long int long_delta_ms; u32 delta_ms; u32 cost; int i, band_exceeded_max = -1; u32 band_exceeded_rate = 0; meter = lookup_meter(dp, meter_id); /* Do not drop the packet when there is no meter. */ if (!meter) return false; /* Lock the meter while using it. */ spin_lock(&meter->lock); long_delta_ms = (now_ms - meter->used); /* ms */ /* Make sure delta_ms will not be too large, so that bucket will not * wrap around below. */ delta_ms = (long_delta_ms > (long long int)meter->max_delta_t) ? meter->max_delta_t : (u32)long_delta_ms; /* Update meter statistics. */ meter->used = now_ms; meter->stats.n_packets += 1; meter->stats.n_bytes += skb->len; /* Bucket rate is either in kilobits per second, or in packets per * second. We maintain the bucket in the units of either bits or * 1/1000th of a packet, correspondingly. * Then, when rate is multiplied with milliseconds, we get the * bucket units: * msec * kbps = bits, and * msec * packets/sec = 1/1000 packets. * * 'cost' is the number of bucket units in this packet. */ cost = (meter->kbps) ? skb->len * 8 : 1000; /* Update all bands and find the one hit with the highest rate. */ for (i = 0; i < meter->n_bands; ++i) { long long int max_bucket_size; band = &meter->bands[i]; max_bucket_size = (band->burst_size + band->rate) * 1000LL; band->bucket += delta_ms * band->rate; if (band->bucket > max_bucket_size) band->bucket = max_bucket_size; if (band->bucket >= cost) { band->bucket -= cost; } else if (band->rate > band_exceeded_rate) { band_exceeded_rate = band->rate; band_exceeded_max = i; } } if (band_exceeded_max >= 0) { /* Update band statistics. */ band = &meter->bands[band_exceeded_max]; band->stats.n_packets += 1; band->stats.n_bytes += skb->len; /* Drop band triggered, let the caller drop the 'skb'. */ if (band->type == OVS_METER_BAND_TYPE_DROP) { spin_unlock(&meter->lock); return true; } } spin_unlock(&meter->lock); return false; } static struct genl_ops dp_meter_genl_ops[] = { { .cmd = OVS_METER_CMD_FEATURES, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .flags = 0, /* OK for unprivileged users. */ .doit = ovs_meter_cmd_features }, { .cmd = OVS_METER_CMD_SET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN * privilege. */ .doit = ovs_meter_cmd_set, }, { .cmd = OVS_METER_CMD_GET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .flags = 0, /* OK for unprivileged users. */ .doit = ovs_meter_cmd_get, }, { .cmd = OVS_METER_CMD_DEL, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN * privilege. */ .doit = ovs_meter_cmd_del }, }; static const struct genl_multicast_group ovs_meter_multicast_group = { .name = OVS_METER_MCGROUP, }; struct genl_family dp_meter_genl_family __ro_after_init = { .hdrsize = sizeof(struct ovs_header), .name = OVS_METER_FAMILY, .version = OVS_METER_VERSION, .maxattr = OVS_METER_ATTR_MAX, .policy = meter_policy, .netnsok = true, .parallel_ops = true, .ops = dp_meter_genl_ops, .n_ops = ARRAY_SIZE(dp_meter_genl_ops), .mcgrps = &ovs_meter_multicast_group, .n_mcgrps = 1, .module = THIS_MODULE, }; int ovs_meters_init(struct datapath *dp) { int i; dp->meters = kmalloc_array(METER_HASH_BUCKETS, sizeof(struct hlist_head), GFP_KERNEL); if (!dp->meters) return -ENOMEM; for (i = 0; i < METER_HASH_BUCKETS; i++) INIT_HLIST_HEAD(&dp->meters[i]); return 0; } void ovs_meters_exit(struct datapath *dp) { int i; for (i = 0; i < METER_HASH_BUCKETS; i++) { struct hlist_head *head = &dp->meters[i]; struct dp_meter *meter; struct hlist_node *n; hlist_for_each_entry_safe(meter, n, head, dp_hash_node) kfree(meter); } kfree(dp->meters); }