2 * Distributed under the terms of the GNU GPL version 2.
3 * Copyright (c) 2007, 2008, 2009, 2010, 2011 Nicira Networks.
5 * Significant portions of this file may be copied from parts of the Linux
6 * kernel, by Linus Torvalds and others.
11 #include <linux/uaccess.h>
12 #include <linux/netdevice.h>
13 #include <linux/etherdevice.h>
14 #include <linux/if_ether.h>
15 #include <linux/if_vlan.h>
16 #include <net/llc_pdu.h>
17 #include <linux/kernel.h>
18 #include <linux/jhash.h>
19 #include <linux/jiffies.h>
20 #include <linux/llc.h>
21 #include <linux/module.h>
23 #include <linux/rcupdate.h>
24 #include <linux/if_arp.h>
25 #include <linux/if_ether.h>
27 #include <linux/ipv6.h>
28 #include <linux/tcp.h>
29 #include <linux/udp.h>
30 #include <linux/icmp.h>
31 #include <linux/icmpv6.h>
32 #include <linux/rculist.h>
33 #include <net/inet_ecn.h>
36 #include <net/ndisc.h>
40 static struct kmem_cache *flow_cache;
41 static unsigned int hash_seed __read_mostly;
43 static int check_header(struct sk_buff *skb, int len)
45 if (unlikely(skb->len < len))
47 if (unlikely(!pskb_may_pull(skb, len)))
52 static bool arphdr_ok(struct sk_buff *skb)
54 return pskb_may_pull(skb, skb_network_offset(skb) +
55 sizeof(struct arp_eth_header));
58 static int check_iphdr(struct sk_buff *skb)
60 unsigned int nh_ofs = skb_network_offset(skb);
64 err = check_header(skb, nh_ofs + sizeof(struct iphdr));
68 ip_len = ip_hdrlen(skb);
69 if (unlikely(ip_len < sizeof(struct iphdr) ||
70 skb->len < nh_ofs + ip_len))
73 skb_set_transport_header(skb, nh_ofs + ip_len);
77 static bool tcphdr_ok(struct sk_buff *skb)
79 int th_ofs = skb_transport_offset(skb);
82 if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
85 tcp_len = tcp_hdrlen(skb);
86 if (unlikely(tcp_len < sizeof(struct tcphdr) ||
87 skb->len < th_ofs + tcp_len))
93 static bool udphdr_ok(struct sk_buff *skb)
95 return pskb_may_pull(skb, skb_transport_offset(skb) +
96 sizeof(struct udphdr));
99 static bool icmphdr_ok(struct sk_buff *skb)
101 return pskb_may_pull(skb, skb_transport_offset(skb) +
102 sizeof(struct icmphdr));
105 u64 flow_used_time(unsigned long flow_jiffies)
107 struct timespec cur_ts;
110 ktime_get_ts(&cur_ts);
111 idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
112 cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC +
113 cur_ts.tv_nsec / NSEC_PER_MSEC;
115 return cur_ms - idle_ms;
118 #define SW_FLOW_KEY_OFFSET(field) \
119 (offsetof(struct sw_flow_key, field) + \
120 FIELD_SIZEOF(struct sw_flow_key, field))
123 * skip_exthdr - skip any IPv6 extension headers
124 * @skb: skbuff to parse
125 * @start: offset of first extension header
126 * @nexthdrp: Initially, points to the type of the extension header at @start.
127 * This function updates it to point to the extension header at the final
129 * @tos_frag: Points to the @tos_frag member in a &struct sw_flow_key. This
130 * function sets an appropriate %OVS_FRAG_TYPE_* value.
132 * This is based on ipv6_skip_exthdr() but adds the updates to *@tos_frag.
134 * When there is more than one fragment header, this version reports whether
135 * the final fragment header that it examines is a first fragment.
137 * Returns the final payload offset, or -1 on error.
139 static int skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
142 u8 nexthdr = *nexthdrp;
144 while (ipv6_ext_hdr(nexthdr)) {
145 struct ipv6_opt_hdr _hdr, *hp;
148 if (nexthdr == NEXTHDR_NONE)
150 hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
153 if (nexthdr == NEXTHDR_FRAGMENT) {
154 __be16 _frag_off, *fp;
155 fp = skb_header_pointer(skb,
156 start+offsetof(struct frag_hdr,
163 *tos_frag &= ~OVS_FRAG_TYPE_MASK;
164 if (ntohs(*fp) & ~0x7) {
165 *tos_frag |= OVS_FRAG_TYPE_LATER;
168 *tos_frag |= OVS_FRAG_TYPE_FIRST;
170 } else if (nexthdr == NEXTHDR_AUTH)
171 hdrlen = (hp->hdrlen+2)<<2;
173 hdrlen = ipv6_optlen(hp);
175 nexthdr = hp->nexthdr;
183 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key,
186 unsigned int nh_ofs = skb_network_offset(skb);
193 *key_lenp = SW_FLOW_KEY_OFFSET(ipv6.addr);
195 err = check_header(skb, nh_ofs + sizeof(*nh));
200 nexthdr = nh->nexthdr;
201 payload_ofs = (u8 *)(nh + 1) - skb->data;
203 key->ip.proto = NEXTHDR_NONE;
204 key->ip.tos_frag = ipv6_get_dsfield(nh) & ~INET_ECN_MASK;
205 ipv6_addr_copy(&key->ipv6.addr.src, &nh->saddr);
206 ipv6_addr_copy(&key->ipv6.addr.dst, &nh->daddr);
208 payload_ofs = skip_exthdr(skb, payload_ofs,
209 &nexthdr, &key->ip.tos_frag);
210 if (unlikely(payload_ofs < 0))
213 nh_len = payload_ofs - nh_ofs;
214 skb_set_transport_header(skb, nh_ofs + nh_len);
215 key->ip.proto = nexthdr;
219 static bool icmp6hdr_ok(struct sk_buff *skb)
221 return pskb_may_pull(skb, skb_transport_offset(skb) +
222 sizeof(struct icmp6hdr));
225 #define TCP_FLAGS_OFFSET 13
226 #define TCP_FLAG_MASK 0x3f
228 void flow_used(struct sw_flow *flow, struct sk_buff *skb)
232 if (flow->key.eth.type == htons(ETH_P_IP) &&
233 flow->key.ip.proto == IPPROTO_TCP) {
234 u8 *tcp = (u8 *)tcp_hdr(skb);
235 tcp_flags = *(tcp + TCP_FLAGS_OFFSET) & TCP_FLAG_MASK;
238 spin_lock(&flow->lock);
239 flow->used = jiffies;
240 flow->packet_count++;
241 flow->byte_count += skb->len;
242 flow->tcp_flags |= tcp_flags;
243 spin_unlock(&flow->lock);
246 struct sw_flow_actions *flow_actions_alloc(const struct nlattr *actions)
248 int actions_len = nla_len(actions);
249 struct sw_flow_actions *sfa;
251 /* At least DP_MAX_PORTS actions are required to be able to flood a
252 * packet to every port. Factor of 2 allows for setting VLAN tags,
254 if (actions_len > 2 * DP_MAX_PORTS * nla_total_size(4))
255 return ERR_PTR(-EINVAL);
257 sfa = kmalloc(sizeof(*sfa) + actions_len, GFP_KERNEL);
259 return ERR_PTR(-ENOMEM);
261 sfa->actions_len = actions_len;
262 memcpy(sfa->actions, nla_data(actions), actions_len);
266 struct sw_flow *flow_alloc(void)
268 struct sw_flow *flow;
270 flow = kmem_cache_alloc(flow_cache, GFP_KERNEL);
272 return ERR_PTR(-ENOMEM);
274 spin_lock_init(&flow->lock);
275 atomic_set(&flow->refcnt, 1);
276 flow->sf_acts = NULL;
282 static struct hlist_head __rcu *find_bucket(struct flow_table * table, u32 hash)
284 return flex_array_get(table->buckets,
285 (hash & (table->n_buckets - 1)));
288 static struct flex_array __rcu *alloc_buckets(unsigned int n_buckets)
290 struct flex_array __rcu *buckets;
293 buckets = flex_array_alloc(sizeof(struct hlist_head *),
294 n_buckets, GFP_KERNEL);
298 err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
300 flex_array_free(buckets);
304 for (i = 0; i < n_buckets; i++)
305 INIT_HLIST_HEAD((struct hlist_head *)
306 flex_array_get(buckets, i));
311 static void free_buckets(struct flex_array *buckets)
313 flex_array_free(buckets);
316 struct flow_table *flow_tbl_alloc(int new_size)
318 struct flow_table *table = kmalloc(sizeof(*table), GFP_KERNEL);
323 table->buckets = alloc_buckets(new_size);
325 if (!table->buckets) {
329 table->n_buckets = new_size;
335 static void flow_free(struct sw_flow *flow)
341 void flow_tbl_destroy(struct flow_table *table)
348 for (i = 0; i < table->n_buckets; i++) {
349 struct sw_flow *flow;
350 struct hlist_head *head = flex_array_get(table->buckets, i);
351 struct hlist_node *node, *n;
353 hlist_for_each_entry_safe(flow, node, n, head, hash_node) {
354 hlist_del_init_rcu(&flow->hash_node);
359 free_buckets(table->buckets);
363 static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
365 struct flow_table *table = container_of(rcu, struct flow_table, rcu);
367 flow_tbl_destroy(table);
370 void flow_tbl_deferred_destroy(struct flow_table *table)
375 call_rcu(&table->rcu, flow_tbl_destroy_rcu_cb);
378 struct sw_flow *flow_tbl_next(struct flow_table *table, u32 *bucket, u32 *last)
380 struct sw_flow *flow;
381 struct hlist_head *head;
382 struct hlist_node *n;
385 while (*bucket < table->n_buckets) {
387 head = flex_array_get(table->buckets, *bucket);
388 hlist_for_each_entry_rcu(flow, n, head, hash_node) {
403 struct flow_table *flow_tbl_expand(struct flow_table *table)
405 struct flow_table *new_table;
406 int n_buckets = table->n_buckets * 2;
409 new_table = flow_tbl_alloc(n_buckets);
411 return ERR_PTR(-ENOMEM);
413 for (i = 0; i < table->n_buckets; i++) {
414 struct sw_flow *flow;
415 struct hlist_head *head;
416 struct hlist_node *n, *pos;
418 head = flex_array_get(table->buckets, i);
420 hlist_for_each_entry_safe(flow, n, pos, head, hash_node) {
421 hlist_del_init_rcu(&flow->hash_node);
422 flow_tbl_insert(new_table, flow);
429 /* RCU callback used by flow_deferred_free. */
430 static void rcu_free_flow_callback(struct rcu_head *rcu)
432 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
438 /* Schedules 'flow' to be freed after the next RCU grace period.
439 * The caller must hold rcu_read_lock for this to be sensible. */
440 void flow_deferred_free(struct sw_flow *flow)
442 call_rcu(&flow->rcu, rcu_free_flow_callback);
445 void flow_hold(struct sw_flow *flow)
447 atomic_inc(&flow->refcnt);
450 void flow_put(struct sw_flow *flow)
455 if (atomic_dec_and_test(&flow->refcnt)) {
456 kfree((struct sf_flow_acts __force *)flow->sf_acts);
457 kmem_cache_free(flow_cache, flow);
461 /* RCU callback used by flow_deferred_free_acts. */
462 static void rcu_free_acts_callback(struct rcu_head *rcu)
464 struct sw_flow_actions *sf_acts = container_of(rcu,
465 struct sw_flow_actions, rcu);
469 /* Schedules 'sf_acts' to be freed after the next RCU grace period.
470 * The caller must hold rcu_read_lock for this to be sensible. */
471 void flow_deferred_free_acts(struct sw_flow_actions *sf_acts)
473 call_rcu(&sf_acts->rcu, rcu_free_acts_callback);
476 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
479 __be16 eth_type; /* ETH_P_8021Q */
482 struct qtag_prefix *qp;
484 if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) +
488 qp = (struct qtag_prefix *) skb->data;
489 key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT);
490 __skb_pull(skb, sizeof(struct qtag_prefix));
495 static __be16 parse_ethertype(struct sk_buff *skb)
497 struct llc_snap_hdr {
498 u8 dsap; /* Always 0xAA */
499 u8 ssap; /* Always 0xAA */
504 struct llc_snap_hdr *llc;
507 proto = *(__be16 *) skb->data;
508 __skb_pull(skb, sizeof(__be16));
510 if (ntohs(proto) >= 1536)
513 if (skb->len < sizeof(struct llc_snap_hdr))
514 return htons(ETH_P_802_2);
516 if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
519 llc = (struct llc_snap_hdr *) skb->data;
520 if (llc->dsap != LLC_SAP_SNAP ||
521 llc->ssap != LLC_SAP_SNAP ||
522 (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
523 return htons(ETH_P_802_2);
525 __skb_pull(skb, sizeof(struct llc_snap_hdr));
526 return llc->ethertype;
529 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
530 int *key_lenp, int nh_len)
532 struct icmp6hdr *icmp = icmp6_hdr(skb);
536 /* The ICMPv6 type and code fields use the 16-bit transport port
537 * fields, so we need to store them in 16-bit network byte order.
539 key->ipv6.tp.src = htons(icmp->icmp6_type);
540 key->ipv6.tp.dst = htons(icmp->icmp6_code);
541 key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
543 if (icmp->icmp6_code == 0 &&
544 (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
545 icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
546 int icmp_len = skb->len - skb_transport_offset(skb);
550 key_len = SW_FLOW_KEY_OFFSET(ipv6.nd);
552 /* In order to process neighbor discovery options, we need the
555 if (unlikely(icmp_len < sizeof(*nd)))
557 if (unlikely(skb_linearize(skb))) {
562 nd = (struct nd_msg *)skb_transport_header(skb);
563 ipv6_addr_copy(&key->ipv6.nd.target, &nd->target);
564 key_len = SW_FLOW_KEY_OFFSET(ipv6.nd);
566 icmp_len -= sizeof(*nd);
568 while (icmp_len >= 8) {
569 struct nd_opt_hdr *nd_opt =
570 (struct nd_opt_hdr *)(nd->opt + offset);
571 int opt_len = nd_opt->nd_opt_len * 8;
573 if (unlikely(!opt_len || opt_len > icmp_len))
576 /* Store the link layer address if the appropriate
577 * option is provided. It is considered an error if
578 * the same link layer option is specified twice.
580 if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
582 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
584 memcpy(key->ipv6.nd.sll,
585 &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
586 } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
588 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
590 memcpy(key->ipv6.nd.tll,
591 &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
602 memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
603 memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
604 memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
612 * flow_extract - extracts a flow key from an Ethernet frame.
613 * @skb: sk_buff that contains the frame, with skb->data pointing to the
615 * @in_port: port number on which @skb was received.
616 * @key: output flow key
617 * @key_lenp: length of output flow key
619 * The caller must ensure that skb->len >= ETH_HLEN.
621 * Returns 0 if successful, otherwise a negative errno value.
623 * Initializes @skb header pointers as follows:
625 * - skb->mac_header: the Ethernet header.
627 * - skb->network_header: just past the Ethernet header, or just past the
628 * VLAN header, to the first byte of the Ethernet payload.
630 * - skb->transport_header: If key->dl_type is ETH_P_IP or ETH_P_IPV6
631 * on output, then just past the IP header, if one is present and
632 * of a correct length, otherwise the same as skb->network_header.
633 * For other key->dl_type values it is left untouched.
635 int flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key,
639 int key_len = SW_FLOW_KEY_OFFSET(eth);
642 memset(key, 0, sizeof(*key));
644 key->phy.priority = skb->priority;
645 key->phy.tun_id = OVS_CB(skb)->tun_id;
646 key->phy.in_port = in_port;
648 skb_reset_mac_header(skb);
650 /* Link layer. We are guaranteed to have at least the 14 byte Ethernet
651 * header in the linear data area.
654 memcpy(key->eth.src, eth->h_source, ETH_ALEN);
655 memcpy(key->eth.dst, eth->h_dest, ETH_ALEN);
657 __skb_pull(skb, 2 * ETH_ALEN);
659 if (vlan_tx_tag_present(skb))
660 key->eth.tci = htons(vlan_get_tci(skb));
661 else if (eth->h_proto == htons(ETH_P_8021Q))
662 if (unlikely(parse_vlan(skb, key)))
665 key->eth.type = parse_ethertype(skb);
666 if (unlikely(key->eth.type == htons(0)))
669 skb_reset_network_header(skb);
670 __skb_push(skb, skb->data - skb_mac_header(skb));
673 if (key->eth.type == htons(ETH_P_IP)) {
677 key_len = SW_FLOW_KEY_OFFSET(ipv4.addr);
679 error = check_iphdr(skb);
680 if (unlikely(error)) {
681 if (error == -EINVAL) {
682 skb->transport_header = skb->network_header;
689 key->ipv4.addr.src = nh->saddr;
690 key->ipv4.addr.dst = nh->daddr;
692 key->ip.proto = nh->protocol;
693 key->ip.tos_frag = nh->tos & ~INET_ECN_MASK;
695 offset = nh->frag_off & htons(IP_OFFSET);
697 key->ip.tos_frag |= OVS_FRAG_TYPE_LATER;
700 if (nh->frag_off & htons(IP_MF) ||
701 skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
702 key->ip.tos_frag |= OVS_FRAG_TYPE_FIRST;
704 /* Transport layer. */
705 if (key->ip.proto == IPPROTO_TCP) {
706 key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
707 if (tcphdr_ok(skb)) {
708 struct tcphdr *tcp = tcp_hdr(skb);
709 key->ipv4.tp.src = tcp->source;
710 key->ipv4.tp.dst = tcp->dest;
712 } else if (key->ip.proto == IPPROTO_UDP) {
713 key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
714 if (udphdr_ok(skb)) {
715 struct udphdr *udp = udp_hdr(skb);
716 key->ipv4.tp.src = udp->source;
717 key->ipv4.tp.dst = udp->dest;
719 } else if (key->ip.proto == IPPROTO_ICMP) {
720 key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
721 if (icmphdr_ok(skb)) {
722 struct icmphdr *icmp = icmp_hdr(skb);
723 /* The ICMP type and code fields use the 16-bit
724 * transport port fields, so we need to store
725 * them in 16-bit network byte order. */
726 key->ipv4.tp.src = htons(icmp->type);
727 key->ipv4.tp.dst = htons(icmp->code);
731 } else if (key->eth.type == htons(ETH_P_ARP) && arphdr_ok(skb)) {
732 struct arp_eth_header *arp;
734 arp = (struct arp_eth_header *)skb_network_header(skb);
736 if (arp->ar_hrd == htons(ARPHRD_ETHER)
737 && arp->ar_pro == htons(ETH_P_IP)
738 && arp->ar_hln == ETH_ALEN
739 && arp->ar_pln == 4) {
741 /* We only match on the lower 8 bits of the opcode. */
742 if (ntohs(arp->ar_op) <= 0xff)
743 key->ip.proto = ntohs(arp->ar_op);
745 if (key->ip.proto == ARPOP_REQUEST
746 || key->ip.proto == ARPOP_REPLY) {
747 memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
748 memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
749 memcpy(key->ipv4.arp.sha, arp->ar_sha, ETH_ALEN);
750 memcpy(key->ipv4.arp.tha, arp->ar_tha, ETH_ALEN);
751 key_len = SW_FLOW_KEY_OFFSET(ipv4.arp);
754 } else if (key->eth.type == htons(ETH_P_IPV6)) {
755 int nh_len; /* IPv6 Header + Extensions */
757 nh_len = parse_ipv6hdr(skb, key, &key_len);
758 if (unlikely(nh_len < 0)) {
759 if (nh_len == -EINVAL)
760 skb->transport_header = skb->network_header;
766 if ((key->ip.tos_frag & OVS_FRAG_TYPE_MASK) == OVS_FRAG_TYPE_LATER)
768 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
769 key->ip.tos_frag |= OVS_FRAG_TYPE_FIRST;
771 /* Transport layer. */
772 if (key->ip.proto == NEXTHDR_TCP) {
773 key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
774 if (tcphdr_ok(skb)) {
775 struct tcphdr *tcp = tcp_hdr(skb);
776 key->ipv6.tp.src = tcp->source;
777 key->ipv6.tp.dst = tcp->dest;
779 } else if (key->ip.proto == NEXTHDR_UDP) {
780 key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
781 if (udphdr_ok(skb)) {
782 struct udphdr *udp = udp_hdr(skb);
783 key->ipv6.tp.src = udp->source;
784 key->ipv6.tp.dst = udp->dest;
786 } else if (key->ip.proto == NEXTHDR_ICMP) {
787 key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
788 if (icmp6hdr_ok(skb)) {
789 error = parse_icmpv6(skb, key, &key_len, nh_len);
801 u32 flow_hash(const struct sw_flow_key *key, int key_len)
803 return jhash2((u32 *)key, DIV_ROUND_UP(key_len, sizeof(u32)), hash_seed);
806 struct sw_flow *flow_tbl_lookup(struct flow_table *table,
807 struct sw_flow_key *key, int key_len)
809 struct sw_flow *flow;
810 struct hlist_node *n;
811 struct hlist_head *head;
814 hash = flow_hash(key, key_len);
816 head = find_bucket(table, hash);
817 hlist_for_each_entry_rcu(flow, n, head, hash_node) {
819 if (flow->hash == hash &&
820 !memcmp(&flow->key, key, key_len)) {
827 void flow_tbl_insert(struct flow_table *table, struct sw_flow *flow)
829 struct hlist_head *head;
831 head = find_bucket(table, flow->hash);
832 hlist_add_head_rcu(&flow->hash_node, head);
836 void flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
838 if (!hlist_unhashed(&flow->hash_node)) {
839 hlist_del_init_rcu(&flow->hash_node);
841 BUG_ON(table->count < 0);
845 static int parse_tos_frag(struct sw_flow_key *swkey, u8 tos, u8 frag)
847 if (tos & INET_ECN_MASK || frag > OVS_FRAG_TYPE_MAX)
850 swkey->ip.tos_frag = tos | frag;
854 /* The size of the argument for each %OVS_KEY_ATTR_* Netlink attribute. */
855 const u32 ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
856 [OVS_KEY_ATTR_PRIORITY] = 4,
857 [OVS_KEY_ATTR_TUN_ID] = 8,
858 [OVS_KEY_ATTR_IN_PORT] = 4,
859 [OVS_KEY_ATTR_ETHERNET] = sizeof(struct ovs_key_ethernet),
860 [OVS_KEY_ATTR_8021Q] = sizeof(struct ovs_key_8021q),
861 [OVS_KEY_ATTR_ETHERTYPE] = 2,
862 [OVS_KEY_ATTR_IPV4] = sizeof(struct ovs_key_ipv4),
863 [OVS_KEY_ATTR_IPV6] = sizeof(struct ovs_key_ipv6),
864 [OVS_KEY_ATTR_TCP] = sizeof(struct ovs_key_tcp),
865 [OVS_KEY_ATTR_UDP] = sizeof(struct ovs_key_udp),
866 [OVS_KEY_ATTR_ICMP] = sizeof(struct ovs_key_icmp),
867 [OVS_KEY_ATTR_ICMPV6] = sizeof(struct ovs_key_icmpv6),
868 [OVS_KEY_ATTR_ARP] = sizeof(struct ovs_key_arp),
869 [OVS_KEY_ATTR_ND] = sizeof(struct ovs_key_nd),
873 * flow_from_nlattrs - parses Netlink attributes into a flow key.
874 * @swkey: receives the extracted flow key.
875 * @key_lenp: number of bytes used in @swkey.
876 * @attr: Netlink attribute holding nested %OVS_KEY_ATTR_* Netlink attribute
879 * This state machine accepts the following forms, with [] for optional
880 * elements and | for alternatives:
882 * [priority] [tun_id] [in_port] ethernet [8021q] [ethertype \
883 * [IPv4 [TCP|UDP|ICMP] | IPv6 [TCP|UDP|ICMPv6 [ND]] | ARP]]
885 * except that IPv4 or IPv6 terminates the sequence if its @ipv4_frag or
886 * @ipv6_frag member, respectively, equals %OVS_FRAG_TYPE_LATER.
888 int flow_from_nlattrs(struct sw_flow_key *swkey, int *key_lenp,
889 const struct nlattr *attr)
892 enum ovs_frag_type frag_type;
893 const struct nlattr *nla;
898 memset(swkey, 0, sizeof(*swkey));
899 swkey->phy.in_port = USHRT_MAX;
900 swkey->eth.type = htons(ETH_P_802_2);
901 key_len = SW_FLOW_KEY_OFFSET(eth);
903 prev_type = OVS_KEY_ATTR_UNSPEC;
904 nla_for_each_nested(nla, attr, rem) {
905 const struct ovs_key_ethernet *eth_key;
906 const struct ovs_key_8021q *q_key;
907 const struct ovs_key_ipv4 *ipv4_key;
908 const struct ovs_key_ipv6 *ipv6_key;
909 const struct ovs_key_tcp *tcp_key;
910 const struct ovs_key_udp *udp_key;
911 const struct ovs_key_icmp *icmp_key;
912 const struct ovs_key_icmpv6 *icmpv6_key;
913 const struct ovs_key_arp *arp_key;
914 const struct ovs_key_nd *nd_key;
916 int type = nla_type(nla);
918 if (type > OVS_KEY_ATTR_MAX ||
919 nla_len(nla) != ovs_key_lens[type])
922 #define TRANSITION(PREV_TYPE, TYPE) (((PREV_TYPE) << 16) | (TYPE))
923 switch (TRANSITION(prev_type, type)) {
924 case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_PRIORITY):
925 swkey->phy.priority = nla_get_u32(nla);
928 case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_TUN_ID):
929 case TRANSITION(OVS_KEY_ATTR_PRIORITY, OVS_KEY_ATTR_TUN_ID):
930 swkey->phy.tun_id = nla_get_be64(nla);
933 case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_IN_PORT):
934 case TRANSITION(OVS_KEY_ATTR_PRIORITY, OVS_KEY_ATTR_IN_PORT):
935 case TRANSITION(OVS_KEY_ATTR_TUN_ID, OVS_KEY_ATTR_IN_PORT):
936 if (nla_get_u32(nla) >= DP_MAX_PORTS)
938 swkey->phy.in_port = nla_get_u32(nla);
941 case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_ETHERNET):
942 case TRANSITION(OVS_KEY_ATTR_PRIORITY, OVS_KEY_ATTR_ETHERNET):
943 case TRANSITION(OVS_KEY_ATTR_TUN_ID, OVS_KEY_ATTR_ETHERNET):
944 case TRANSITION(OVS_KEY_ATTR_IN_PORT, OVS_KEY_ATTR_ETHERNET):
945 eth_key = nla_data(nla);
946 memcpy(swkey->eth.src, eth_key->eth_src, ETH_ALEN);
947 memcpy(swkey->eth.dst, eth_key->eth_dst, ETH_ALEN);
950 case TRANSITION(OVS_KEY_ATTR_ETHERNET, OVS_KEY_ATTR_8021Q):
951 q_key = nla_data(nla);
952 /* Only standard 0x8100 VLANs currently supported. */
953 if (q_key->q_tpid != htons(ETH_P_8021Q))
955 if (q_key->q_tci & htons(VLAN_TAG_PRESENT))
957 swkey->eth.tci = q_key->q_tci | htons(VLAN_TAG_PRESENT);
960 case TRANSITION(OVS_KEY_ATTR_8021Q, OVS_KEY_ATTR_ETHERTYPE):
961 case TRANSITION(OVS_KEY_ATTR_ETHERNET, OVS_KEY_ATTR_ETHERTYPE):
962 swkey->eth.type = nla_get_be16(nla);
963 if (ntohs(swkey->eth.type) < 1536)
967 case TRANSITION(OVS_KEY_ATTR_ETHERTYPE, OVS_KEY_ATTR_IPV4):
968 key_len = SW_FLOW_KEY_OFFSET(ipv4.addr);
969 if (swkey->eth.type != htons(ETH_P_IP))
971 ipv4_key = nla_data(nla);
972 swkey->ip.proto = ipv4_key->ipv4_proto;
973 if (parse_tos_frag(swkey, ipv4_key->ipv4_tos,
974 ipv4_key->ipv4_frag))
976 swkey->ipv4.addr.src = ipv4_key->ipv4_src;
977 swkey->ipv4.addr.dst = ipv4_key->ipv4_dst;
980 case TRANSITION(OVS_KEY_ATTR_ETHERTYPE, OVS_KEY_ATTR_IPV6):
981 key_len = SW_FLOW_KEY_OFFSET(ipv6.addr);
982 if (swkey->eth.type != htons(ETH_P_IPV6))
984 ipv6_key = nla_data(nla);
985 swkey->ip.proto = ipv6_key->ipv6_proto;
986 if (parse_tos_frag(swkey, ipv6_key->ipv6_tos,
987 ipv6_key->ipv6_frag))
989 memcpy(&swkey->ipv6.addr.src, ipv6_key->ipv6_src,
990 sizeof(swkey->ipv6.addr.src));
991 memcpy(&swkey->ipv6.addr.dst, ipv6_key->ipv6_dst,
992 sizeof(swkey->ipv6.addr.dst));
995 case TRANSITION(OVS_KEY_ATTR_IPV4, OVS_KEY_ATTR_TCP):
996 key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
997 if (swkey->ip.proto != IPPROTO_TCP)
999 tcp_key = nla_data(nla);
1000 swkey->ipv4.tp.src = tcp_key->tcp_src;
1001 swkey->ipv4.tp.dst = tcp_key->tcp_dst;
1004 case TRANSITION(OVS_KEY_ATTR_IPV6, OVS_KEY_ATTR_TCP):
1005 key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
1006 if (swkey->ip.proto != IPPROTO_TCP)
1008 tcp_key = nla_data(nla);
1009 swkey->ipv6.tp.src = tcp_key->tcp_src;
1010 swkey->ipv6.tp.dst = tcp_key->tcp_dst;
1013 case TRANSITION(OVS_KEY_ATTR_IPV4, OVS_KEY_ATTR_UDP):
1014 key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
1015 if (swkey->ip.proto != IPPROTO_UDP)
1017 udp_key = nla_data(nla);
1018 swkey->ipv4.tp.src = udp_key->udp_src;
1019 swkey->ipv4.tp.dst = udp_key->udp_dst;
1022 case TRANSITION(OVS_KEY_ATTR_IPV6, OVS_KEY_ATTR_UDP):
1023 key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
1024 if (swkey->ip.proto != IPPROTO_UDP)
1026 udp_key = nla_data(nla);
1027 swkey->ipv6.tp.src = udp_key->udp_src;
1028 swkey->ipv6.tp.dst = udp_key->udp_dst;
1031 case TRANSITION(OVS_KEY_ATTR_IPV4, OVS_KEY_ATTR_ICMP):
1032 key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
1033 if (swkey->ip.proto != IPPROTO_ICMP)
1035 icmp_key = nla_data(nla);
1036 swkey->ipv4.tp.src = htons(icmp_key->icmp_type);
1037 swkey->ipv4.tp.dst = htons(icmp_key->icmp_code);
1040 case TRANSITION(OVS_KEY_ATTR_IPV6, OVS_KEY_ATTR_ICMPV6):
1041 key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
1042 if (swkey->ip.proto != IPPROTO_ICMPV6)
1044 icmpv6_key = nla_data(nla);
1045 swkey->ipv6.tp.src = htons(icmpv6_key->icmpv6_type);
1046 swkey->ipv6.tp.dst = htons(icmpv6_key->icmpv6_code);
1049 case TRANSITION(OVS_KEY_ATTR_ETHERTYPE, OVS_KEY_ATTR_ARP):
1050 key_len = SW_FLOW_KEY_OFFSET(ipv4.arp);
1051 if (swkey->eth.type != htons(ETH_P_ARP))
1053 arp_key = nla_data(nla);
1054 swkey->ipv4.addr.src = arp_key->arp_sip;
1055 swkey->ipv4.addr.dst = arp_key->arp_tip;
1056 if (arp_key->arp_op & htons(0xff00))
1058 swkey->ip.proto = ntohs(arp_key->arp_op);
1059 memcpy(swkey->ipv4.arp.sha, arp_key->arp_sha, ETH_ALEN);
1060 memcpy(swkey->ipv4.arp.tha, arp_key->arp_tha, ETH_ALEN);
1063 case TRANSITION(OVS_KEY_ATTR_ICMPV6, OVS_KEY_ATTR_ND):
1064 key_len = SW_FLOW_KEY_OFFSET(ipv6.nd);
1065 if (swkey->ipv6.tp.src != htons(NDISC_NEIGHBOUR_SOLICITATION)
1066 && swkey->ipv6.tp.src != htons(NDISC_NEIGHBOUR_ADVERTISEMENT))
1068 nd_key = nla_data(nla);
1069 memcpy(&swkey->ipv6.nd.target, nd_key->nd_target,
1070 sizeof(swkey->ipv6.nd.target));
1071 memcpy(swkey->ipv6.nd.sll, nd_key->nd_sll, ETH_ALEN);
1072 memcpy(swkey->ipv6.nd.tll, nd_key->nd_tll, ETH_ALEN);
1084 frag_type = swkey->ip.tos_frag & OVS_FRAG_TYPE_MASK;
1085 switch (prev_type) {
1086 case OVS_KEY_ATTR_UNSPEC:
1089 case OVS_KEY_ATTR_PRIORITY:
1090 case OVS_KEY_ATTR_TUN_ID:
1091 case OVS_KEY_ATTR_IN_PORT:
1094 case OVS_KEY_ATTR_ETHERNET:
1095 case OVS_KEY_ATTR_8021Q:
1098 case OVS_KEY_ATTR_ETHERTYPE:
1099 if (swkey->eth.type == htons(ETH_P_IP) ||
1100 swkey->eth.type == htons(ETH_P_IPV6) ||
1101 swkey->eth.type == htons(ETH_P_ARP))
1105 case OVS_KEY_ATTR_IPV4:
1106 if (frag_type == OVS_FRAG_TYPE_LATER)
1108 if (swkey->ip.proto == IPPROTO_TCP ||
1109 swkey->ip.proto == IPPROTO_UDP ||
1110 swkey->ip.proto == IPPROTO_ICMP)
1114 case OVS_KEY_ATTR_IPV6:
1115 if (frag_type == OVS_FRAG_TYPE_LATER)
1117 if (swkey->ip.proto == IPPROTO_TCP ||
1118 swkey->ip.proto == IPPROTO_UDP ||
1119 swkey->ip.proto == IPPROTO_ICMPV6)
1123 case OVS_KEY_ATTR_ICMPV6:
1124 if (swkey->ipv6.tp.src == htons(NDISC_NEIGHBOUR_SOLICITATION) ||
1125 swkey->ipv6.tp.src == htons(NDISC_NEIGHBOUR_ADVERTISEMENT) ||
1126 frag_type == OVS_FRAG_TYPE_LATER)
1130 case OVS_KEY_ATTR_TCP:
1131 case OVS_KEY_ATTR_UDP:
1132 case OVS_KEY_ATTR_ICMP:
1133 case OVS_KEY_ATTR_ND:
1134 if (frag_type == OVS_FRAG_TYPE_LATER)
1138 case OVS_KEY_ATTR_ARP:
1149 *key_lenp = key_len;
1154 * flow_metadata_from_nlattrs - parses Netlink attributes into a flow key.
1155 * @in_port: receives the extracted input port.
1156 * @tun_id: receives the extracted tunnel ID.
1157 * @key: Netlink attribute holding nested %OVS_KEY_ATTR_* Netlink attribute
1160 * This parses a series of Netlink attributes that form a flow key, which must
1161 * take the same form accepted by flow_from_nlattrs(), but only enough of it to
1162 * get the metadata, that is, the parts of the flow key that cannot be
1163 * extracted from the packet itself.
1165 int flow_metadata_from_nlattrs(u32 *priority, u16 *in_port, __be64 *tun_id,
1166 const struct nlattr *attr)
1168 const struct nlattr *nla;
1172 *in_port = USHRT_MAX;
1176 prev_type = OVS_KEY_ATTR_UNSPEC;
1177 nla_for_each_nested(nla, attr, rem) {
1178 int type = nla_type(nla);
1180 if (type > OVS_KEY_ATTR_MAX || nla_len(nla) != ovs_key_lens[type])
1183 switch (TRANSITION(prev_type, type)) {
1184 case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_PRIORITY):
1185 *priority = nla_get_u32(nla);
1188 case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_TUN_ID):
1189 case TRANSITION(OVS_KEY_ATTR_PRIORITY, OVS_KEY_ATTR_TUN_ID):
1190 *tun_id = nla_get_be64(nla);
1193 case TRANSITION(OVS_KEY_ATTR_UNSPEC, OVS_KEY_ATTR_IN_PORT):
1194 case TRANSITION(OVS_KEY_ATTR_PRIORITY, OVS_KEY_ATTR_IN_PORT):
1195 case TRANSITION(OVS_KEY_ATTR_TUN_ID, OVS_KEY_ATTR_IN_PORT):
1196 if (nla_get_u32(nla) >= DP_MAX_PORTS)
1198 *in_port = nla_get_u32(nla);
1212 int flow_to_nlattrs(const struct sw_flow_key *swkey, struct sk_buff *skb)
1214 struct ovs_key_ethernet *eth_key;
1217 if (swkey->phy.priority)
1218 NLA_PUT_U32(skb, OVS_KEY_ATTR_PRIORITY, swkey->phy.priority);
1220 if (swkey->phy.tun_id != cpu_to_be64(0))
1221 NLA_PUT_BE64(skb, OVS_KEY_ATTR_TUN_ID, swkey->phy.tun_id);
1223 if (swkey->phy.in_port != USHRT_MAX)
1224 NLA_PUT_U32(skb, OVS_KEY_ATTR_IN_PORT, swkey->phy.in_port);
1226 nla = nla_reserve(skb, OVS_KEY_ATTR_ETHERNET, sizeof(*eth_key));
1228 goto nla_put_failure;
1229 eth_key = nla_data(nla);
1230 memcpy(eth_key->eth_src, swkey->eth.src, ETH_ALEN);
1231 memcpy(eth_key->eth_dst, swkey->eth.dst, ETH_ALEN);
1233 if (swkey->eth.tci != htons(0)) {
1234 struct ovs_key_8021q q_key;
1236 q_key.q_tpid = htons(ETH_P_8021Q);
1237 q_key.q_tci = swkey->eth.tci & ~htons(VLAN_TAG_PRESENT);
1238 NLA_PUT(skb, OVS_KEY_ATTR_8021Q, sizeof(q_key), &q_key);
1241 if (swkey->eth.type == htons(ETH_P_802_2))
1244 NLA_PUT_BE16(skb, OVS_KEY_ATTR_ETHERTYPE, swkey->eth.type);
1246 if (swkey->eth.type == htons(ETH_P_IP)) {
1247 struct ovs_key_ipv4 *ipv4_key;
1249 nla = nla_reserve(skb, OVS_KEY_ATTR_IPV4, sizeof(*ipv4_key));
1251 goto nla_put_failure;
1252 ipv4_key = nla_data(nla);
1253 memset(ipv4_key, 0, sizeof(struct ovs_key_ipv4));
1254 ipv4_key->ipv4_src = swkey->ipv4.addr.src;
1255 ipv4_key->ipv4_dst = swkey->ipv4.addr.dst;
1256 ipv4_key->ipv4_proto = swkey->ip.proto;
1257 ipv4_key->ipv4_tos = swkey->ip.tos_frag & ~INET_ECN_MASK;
1258 ipv4_key->ipv4_frag = swkey->ip.tos_frag & OVS_FRAG_TYPE_MASK;
1259 } else if (swkey->eth.type == htons(ETH_P_IPV6)) {
1260 struct ovs_key_ipv6 *ipv6_key;
1262 nla = nla_reserve(skb, OVS_KEY_ATTR_IPV6, sizeof(*ipv6_key));
1264 goto nla_put_failure;
1265 ipv6_key = nla_data(nla);
1266 memset(ipv6_key, 0, sizeof(struct ovs_key_ipv6));
1267 memcpy(ipv6_key->ipv6_src, &swkey->ipv6.addr.src,
1268 sizeof(ipv6_key->ipv6_src));
1269 memcpy(ipv6_key->ipv6_dst, &swkey->ipv6.addr.dst,
1270 sizeof(ipv6_key->ipv6_dst));
1271 ipv6_key->ipv6_proto = swkey->ip.proto;
1272 ipv6_key->ipv6_tos = swkey->ip.tos_frag & ~INET_ECN_MASK;
1273 ipv6_key->ipv6_frag = swkey->ip.tos_frag & OVS_FRAG_TYPE_MASK;
1274 } else if (swkey->eth.type == htons(ETH_P_ARP)) {
1275 struct ovs_key_arp *arp_key;
1277 nla = nla_reserve(skb, OVS_KEY_ATTR_ARP, sizeof(*arp_key));
1279 goto nla_put_failure;
1280 arp_key = nla_data(nla);
1281 memset(arp_key, 0, sizeof(struct ovs_key_arp));
1282 arp_key->arp_sip = swkey->ipv4.addr.src;
1283 arp_key->arp_tip = swkey->ipv4.addr.dst;
1284 arp_key->arp_op = htons(swkey->ip.proto);
1285 memcpy(arp_key->arp_sha, swkey->ipv4.arp.sha, ETH_ALEN);
1286 memcpy(arp_key->arp_tha, swkey->ipv4.arp.tha, ETH_ALEN);
1289 if ((swkey->eth.type == htons(ETH_P_IP) ||
1290 swkey->eth.type == htons(ETH_P_IPV6)) &&
1291 (swkey->ip.tos_frag & OVS_FRAG_TYPE_MASK) != OVS_FRAG_TYPE_LATER) {
1293 if (swkey->ip.proto == IPPROTO_TCP) {
1294 struct ovs_key_tcp *tcp_key;
1296 nla = nla_reserve(skb, OVS_KEY_ATTR_TCP, sizeof(*tcp_key));
1298 goto nla_put_failure;
1299 tcp_key = nla_data(nla);
1300 if (swkey->eth.type == htons(ETH_P_IP)) {
1301 tcp_key->tcp_src = swkey->ipv4.tp.src;
1302 tcp_key->tcp_dst = swkey->ipv4.tp.dst;
1303 } else if (swkey->eth.type == htons(ETH_P_IPV6)) {
1304 tcp_key->tcp_src = swkey->ipv6.tp.src;
1305 tcp_key->tcp_dst = swkey->ipv6.tp.dst;
1307 } else if (swkey->ip.proto == IPPROTO_UDP) {
1308 struct ovs_key_udp *udp_key;
1310 nla = nla_reserve(skb, OVS_KEY_ATTR_UDP, sizeof(*udp_key));
1312 goto nla_put_failure;
1313 udp_key = nla_data(nla);
1314 if (swkey->eth.type == htons(ETH_P_IP)) {
1315 udp_key->udp_src = swkey->ipv4.tp.src;
1316 udp_key->udp_dst = swkey->ipv4.tp.dst;
1317 } else if (swkey->eth.type == htons(ETH_P_IPV6)) {
1318 udp_key->udp_src = swkey->ipv6.tp.src;
1319 udp_key->udp_dst = swkey->ipv6.tp.dst;
1321 } else if (swkey->eth.type == htons(ETH_P_IP) &&
1322 swkey->ip.proto == IPPROTO_ICMP) {
1323 struct ovs_key_icmp *icmp_key;
1325 nla = nla_reserve(skb, OVS_KEY_ATTR_ICMP, sizeof(*icmp_key));
1327 goto nla_put_failure;
1328 icmp_key = nla_data(nla);
1329 icmp_key->icmp_type = ntohs(swkey->ipv4.tp.src);
1330 icmp_key->icmp_code = ntohs(swkey->ipv4.tp.dst);
1331 } else if (swkey->eth.type == htons(ETH_P_IPV6) &&
1332 swkey->ip.proto == IPPROTO_ICMPV6) {
1333 struct ovs_key_icmpv6 *icmpv6_key;
1335 nla = nla_reserve(skb, OVS_KEY_ATTR_ICMPV6,
1336 sizeof(*icmpv6_key));
1338 goto nla_put_failure;
1339 icmpv6_key = nla_data(nla);
1340 icmpv6_key->icmpv6_type = ntohs(swkey->ipv6.tp.src);
1341 icmpv6_key->icmpv6_code = ntohs(swkey->ipv6.tp.dst);
1343 if (icmpv6_key->icmpv6_type == NDISC_NEIGHBOUR_SOLICITATION ||
1344 icmpv6_key->icmpv6_type == NDISC_NEIGHBOUR_ADVERTISEMENT) {
1345 struct ovs_key_nd *nd_key;
1347 nla = nla_reserve(skb, OVS_KEY_ATTR_ND, sizeof(*nd_key));
1349 goto nla_put_failure;
1350 nd_key = nla_data(nla);
1351 memcpy(nd_key->nd_target, &swkey->ipv6.nd.target,
1352 sizeof(nd_key->nd_target));
1353 memcpy(nd_key->nd_sll, swkey->ipv6.nd.sll, ETH_ALEN);
1354 memcpy(nd_key->nd_tll, swkey->ipv6.nd.tll, ETH_ALEN);
1365 /* Initializes the flow module.
1366 * Returns zero if successful or a negative error code. */
1369 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
1371 if (flow_cache == NULL)
1374 get_random_bytes(&hash_seed, sizeof(hash_seed));
1379 /* Uninitializes the flow module. */
1380 void flow_exit(void)
1382 kmem_cache_destroy(flow_cache);