diff options
Diffstat (limited to 'net/openvswitch/flow.c')
| -rw-r--r-- | net/openvswitch/flow.c | 615 | 
1 files changed, 615 insertions, 0 deletions
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c new file mode 100644 index 00000000000..d07ab538fc9 --- /dev/null +++ b/net/openvswitch/flow.c @@ -0,0 +1,615 @@ +/* + * Copyright (c) 2007-2013 Nicira, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA + */ + +#include "flow.h" +#include "datapath.h" +#include <linux/uaccess.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/if_ether.h> +#include <linux/if_vlan.h> +#include <net/llc_pdu.h> +#include <linux/kernel.h> +#include <linux/jhash.h> +#include <linux/jiffies.h> +#include <linux/llc.h> +#include <linux/module.h> +#include <linux/in.h> +#include <linux/rcupdate.h> +#include <linux/if_arp.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/sctp.h> +#include <linux/smp.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/icmp.h> +#include <linux/icmpv6.h> +#include <linux/rculist.h> +#include <net/ip.h> +#include <net/ip_tunnels.h> +#include <net/ipv6.h> +#include <net/ndisc.h> + +u64 ovs_flow_used_time(unsigned long flow_jiffies) +{ +	struct timespec cur_ts; +	u64 cur_ms, idle_ms; + +	ktime_get_ts(&cur_ts); +	idle_ms = jiffies_to_msecs(jiffies - flow_jiffies); +	cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC + +		 cur_ts.tv_nsec / NSEC_PER_MSEC; + +	return cur_ms - idle_ms; +} + +#define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF)) + +void ovs_flow_stats_update(struct sw_flow *flow, __be16 tcp_flags, +			   struct sk_buff *skb) +{ +	struct flow_stats *stats; +	int node = numa_node_id(); + +	stats = rcu_dereference(flow->stats[node]); + +	/* Check if already have node-specific stats. */ +	if (likely(stats)) { +		spin_lock(&stats->lock); +		/* Mark if we write on the pre-allocated stats. */ +		if (node == 0 && unlikely(flow->stats_last_writer != node)) +			flow->stats_last_writer = node; +	} else { +		stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */ +		spin_lock(&stats->lock); + +		/* If the current NUMA-node is the only writer on the +		 * pre-allocated stats keep using them. +		 */ +		if (unlikely(flow->stats_last_writer != node)) { +			/* A previous locker may have already allocated the +			 * stats, so we need to check again.  If node-specific +			 * stats were already allocated, we update the pre- +			 * allocated stats as we have already locked them. +			 */ +			if (likely(flow->stats_last_writer != NUMA_NO_NODE) +			    && likely(!rcu_dereference(flow->stats[node]))) { +				/* Try to allocate node-specific stats. */ +				struct flow_stats *new_stats; + +				new_stats = +					kmem_cache_alloc_node(flow_stats_cache, +							      GFP_THISNODE | +							      __GFP_NOMEMALLOC, +							      node); +				if (likely(new_stats)) { +					new_stats->used = jiffies; +					new_stats->packet_count = 1; +					new_stats->byte_count = skb->len; +					new_stats->tcp_flags = tcp_flags; +					spin_lock_init(&new_stats->lock); + +					rcu_assign_pointer(flow->stats[node], +							   new_stats); +					goto unlock; +				} +			} +			flow->stats_last_writer = node; +		} +	} + +	stats->used = jiffies; +	stats->packet_count++; +	stats->byte_count += skb->len; +	stats->tcp_flags |= tcp_flags; +unlock: +	spin_unlock(&stats->lock); +} + +/* Must be called with rcu_read_lock or ovs_mutex. */ +void ovs_flow_stats_get(const struct sw_flow *flow, +			struct ovs_flow_stats *ovs_stats, +			unsigned long *used, __be16 *tcp_flags) +{ +	int node; + +	*used = 0; +	*tcp_flags = 0; +	memset(ovs_stats, 0, sizeof(*ovs_stats)); + +	for_each_node(node) { +		struct flow_stats *stats = rcu_dereference_ovsl(flow->stats[node]); + +		if (stats) { +			/* Local CPU may write on non-local stats, so we must +			 * block bottom-halves here. +			 */ +			spin_lock_bh(&stats->lock); +			if (!*used || time_after(stats->used, *used)) +				*used = stats->used; +			*tcp_flags |= stats->tcp_flags; +			ovs_stats->n_packets += stats->packet_count; +			ovs_stats->n_bytes += stats->byte_count; +			spin_unlock_bh(&stats->lock); +		} +	} +} + +/* Called with ovs_mutex. */ +void ovs_flow_stats_clear(struct sw_flow *flow) +{ +	int node; + +	for_each_node(node) { +		struct flow_stats *stats = ovsl_dereference(flow->stats[node]); + +		if (stats) { +			spin_lock_bh(&stats->lock); +			stats->used = 0; +			stats->packet_count = 0; +			stats->byte_count = 0; +			stats->tcp_flags = 0; +			spin_unlock_bh(&stats->lock); +		} +	} +} + +static int check_header(struct sk_buff *skb, int len) +{ +	if (unlikely(skb->len < len)) +		return -EINVAL; +	if (unlikely(!pskb_may_pull(skb, len))) +		return -ENOMEM; +	return 0; +} + +static bool arphdr_ok(struct sk_buff *skb) +{ +	return pskb_may_pull(skb, skb_network_offset(skb) + +				  sizeof(struct arp_eth_header)); +} + +static int check_iphdr(struct sk_buff *skb) +{ +	unsigned int nh_ofs = skb_network_offset(skb); +	unsigned int ip_len; +	int err; + +	err = check_header(skb, nh_ofs + sizeof(struct iphdr)); +	if (unlikely(err)) +		return err; + +	ip_len = ip_hdrlen(skb); +	if (unlikely(ip_len < sizeof(struct iphdr) || +		     skb->len < nh_ofs + ip_len)) +		return -EINVAL; + +	skb_set_transport_header(skb, nh_ofs + ip_len); +	return 0; +} + +static bool tcphdr_ok(struct sk_buff *skb) +{ +	int th_ofs = skb_transport_offset(skb); +	int tcp_len; + +	if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr)))) +		return false; + +	tcp_len = tcp_hdrlen(skb); +	if (unlikely(tcp_len < sizeof(struct tcphdr) || +		     skb->len < th_ofs + tcp_len)) +		return false; + +	return true; +} + +static bool udphdr_ok(struct sk_buff *skb) +{ +	return pskb_may_pull(skb, skb_transport_offset(skb) + +				  sizeof(struct udphdr)); +} + +static bool sctphdr_ok(struct sk_buff *skb) +{ +	return pskb_may_pull(skb, skb_transport_offset(skb) + +				  sizeof(struct sctphdr)); +} + +static bool icmphdr_ok(struct sk_buff *skb) +{ +	return pskb_may_pull(skb, skb_transport_offset(skb) + +				  sizeof(struct icmphdr)); +} + +static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key) +{ +	unsigned int nh_ofs = skb_network_offset(skb); +	unsigned int nh_len; +	int payload_ofs; +	struct ipv6hdr *nh; +	uint8_t nexthdr; +	__be16 frag_off; +	int err; + +	err = check_header(skb, nh_ofs + sizeof(*nh)); +	if (unlikely(err)) +		return err; + +	nh = ipv6_hdr(skb); +	nexthdr = nh->nexthdr; +	payload_ofs = (u8 *)(nh + 1) - skb->data; + +	key->ip.proto = NEXTHDR_NONE; +	key->ip.tos = ipv6_get_dsfield(nh); +	key->ip.ttl = nh->hop_limit; +	key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL); +	key->ipv6.addr.src = nh->saddr; +	key->ipv6.addr.dst = nh->daddr; + +	payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off); +	if (unlikely(payload_ofs < 0)) +		return -EINVAL; + +	if (frag_off) { +		if (frag_off & htons(~0x7)) +			key->ip.frag = OVS_FRAG_TYPE_LATER; +		else +			key->ip.frag = OVS_FRAG_TYPE_FIRST; +	} + +	nh_len = payload_ofs - nh_ofs; +	skb_set_transport_header(skb, nh_ofs + nh_len); +	key->ip.proto = nexthdr; +	return nh_len; +} + +static bool icmp6hdr_ok(struct sk_buff *skb) +{ +	return pskb_may_pull(skb, skb_transport_offset(skb) + +				  sizeof(struct icmp6hdr)); +} + +static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key) +{ +	struct qtag_prefix { +		__be16 eth_type; /* ETH_P_8021Q */ +		__be16 tci; +	}; +	struct qtag_prefix *qp; + +	if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16))) +		return 0; + +	if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) + +					 sizeof(__be16)))) +		return -ENOMEM; + +	qp = (struct qtag_prefix *) skb->data; +	key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT); +	__skb_pull(skb, sizeof(struct qtag_prefix)); + +	return 0; +} + +static __be16 parse_ethertype(struct sk_buff *skb) +{ +	struct llc_snap_hdr { +		u8  dsap;  /* Always 0xAA */ +		u8  ssap;  /* Always 0xAA */ +		u8  ctrl; +		u8  oui[3]; +		__be16 ethertype; +	}; +	struct llc_snap_hdr *llc; +	__be16 proto; + +	proto = *(__be16 *) skb->data; +	__skb_pull(skb, sizeof(__be16)); + +	if (ntohs(proto) >= ETH_P_802_3_MIN) +		return proto; + +	if (skb->len < sizeof(struct llc_snap_hdr)) +		return htons(ETH_P_802_2); + +	if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr)))) +		return htons(0); + +	llc = (struct llc_snap_hdr *) skb->data; +	if (llc->dsap != LLC_SAP_SNAP || +	    llc->ssap != LLC_SAP_SNAP || +	    (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0) +		return htons(ETH_P_802_2); + +	__skb_pull(skb, sizeof(struct llc_snap_hdr)); + +	if (ntohs(llc->ethertype) >= ETH_P_802_3_MIN) +		return llc->ethertype; + +	return htons(ETH_P_802_2); +} + +static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key, +			int nh_len) +{ +	struct icmp6hdr *icmp = icmp6_hdr(skb); + +	/* The ICMPv6 type and code fields use the 16-bit transport port +	 * fields, so we need to store them in 16-bit network byte order. +	 */ +	key->tp.src = htons(icmp->icmp6_type); +	key->tp.dst = htons(icmp->icmp6_code); + +	if (icmp->icmp6_code == 0 && +	    (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION || +	     icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) { +		int icmp_len = skb->len - skb_transport_offset(skb); +		struct nd_msg *nd; +		int offset; + +		/* In order to process neighbor discovery options, we need the +		 * entire packet. +		 */ +		if (unlikely(icmp_len < sizeof(*nd))) +			return 0; + +		if (unlikely(skb_linearize(skb))) +			return -ENOMEM; + +		nd = (struct nd_msg *)skb_transport_header(skb); +		key->ipv6.nd.target = nd->target; + +		icmp_len -= sizeof(*nd); +		offset = 0; +		while (icmp_len >= 8) { +			struct nd_opt_hdr *nd_opt = +				 (struct nd_opt_hdr *)(nd->opt + offset); +			int opt_len = nd_opt->nd_opt_len * 8; + +			if (unlikely(!opt_len || opt_len > icmp_len)) +				return 0; + +			/* Store the link layer address if the appropriate +			 * option is provided.  It is considered an error if +			 * the same link layer option is specified twice. +			 */ +			if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR +			    && opt_len == 8) { +				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll))) +					goto invalid; +				ether_addr_copy(key->ipv6.nd.sll, +						&nd->opt[offset+sizeof(*nd_opt)]); +			} else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR +				   && opt_len == 8) { +				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll))) +					goto invalid; +				ether_addr_copy(key->ipv6.nd.tll, +						&nd->opt[offset+sizeof(*nd_opt)]); +			} + +			icmp_len -= opt_len; +			offset += opt_len; +		} +	} + +	return 0; + +invalid: +	memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target)); +	memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll)); +	memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll)); + +	return 0; +} + +/** + * ovs_flow_extract - extracts a flow key from an Ethernet frame. + * @skb: sk_buff that contains the frame, with skb->data pointing to the + * Ethernet header + * @in_port: port number on which @skb was received. + * @key: output flow key + * + * The caller must ensure that skb->len >= ETH_HLEN. + * + * Returns 0 if successful, otherwise a negative errno value. + * + * Initializes @skb header pointers as follows: + * + *    - skb->mac_header: the Ethernet header. + * + *    - skb->network_header: just past the Ethernet header, or just past the + *      VLAN header, to the first byte of the Ethernet payload. + * + *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6 + *      on output, then just past the IP header, if one is present and + *      of a correct length, otherwise the same as skb->network_header. + *      For other key->eth.type values it is left untouched. + */ +int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key) +{ +	int error; +	struct ethhdr *eth; + +	memset(key, 0, sizeof(*key)); + +	key->phy.priority = skb->priority; +	if (OVS_CB(skb)->tun_key) +		memcpy(&key->tun_key, OVS_CB(skb)->tun_key, sizeof(key->tun_key)); +	key->phy.in_port = in_port; +	key->phy.skb_mark = skb->mark; + +	skb_reset_mac_header(skb); + +	/* Link layer.  We are guaranteed to have at least the 14 byte Ethernet +	 * header in the linear data area. +	 */ +	eth = eth_hdr(skb); +	ether_addr_copy(key->eth.src, eth->h_source); +	ether_addr_copy(key->eth.dst, eth->h_dest); + +	__skb_pull(skb, 2 * ETH_ALEN); +	/* We are going to push all headers that we pull, so no need to +	 * update skb->csum here. +	 */ + +	if (vlan_tx_tag_present(skb)) +		key->eth.tci = htons(skb->vlan_tci); +	else if (eth->h_proto == htons(ETH_P_8021Q)) +		if (unlikely(parse_vlan(skb, key))) +			return -ENOMEM; + +	key->eth.type = parse_ethertype(skb); +	if (unlikely(key->eth.type == htons(0))) +		return -ENOMEM; + +	skb_reset_network_header(skb); +	__skb_push(skb, skb->data - skb_mac_header(skb)); + +	/* Network layer. */ +	if (key->eth.type == htons(ETH_P_IP)) { +		struct iphdr *nh; +		__be16 offset; + +		error = check_iphdr(skb); +		if (unlikely(error)) { +			if (error == -EINVAL) { +				skb->transport_header = skb->network_header; +				error = 0; +			} +			return error; +		} + +		nh = ip_hdr(skb); +		key->ipv4.addr.src = nh->saddr; +		key->ipv4.addr.dst = nh->daddr; + +		key->ip.proto = nh->protocol; +		key->ip.tos = nh->tos; +		key->ip.ttl = nh->ttl; + +		offset = nh->frag_off & htons(IP_OFFSET); +		if (offset) { +			key->ip.frag = OVS_FRAG_TYPE_LATER; +			return 0; +		} +		if (nh->frag_off & htons(IP_MF) || +			 skb_shinfo(skb)->gso_type & SKB_GSO_UDP) +			key->ip.frag = OVS_FRAG_TYPE_FIRST; + +		/* Transport layer. */ +		if (key->ip.proto == IPPROTO_TCP) { +			if (tcphdr_ok(skb)) { +				struct tcphdr *tcp = tcp_hdr(skb); +				key->tp.src = tcp->source; +				key->tp.dst = tcp->dest; +				key->tp.flags = TCP_FLAGS_BE16(tcp); +			} +		} else if (key->ip.proto == IPPROTO_UDP) { +			if (udphdr_ok(skb)) { +				struct udphdr *udp = udp_hdr(skb); +				key->tp.src = udp->source; +				key->tp.dst = udp->dest; +			} +		} else if (key->ip.proto == IPPROTO_SCTP) { +			if (sctphdr_ok(skb)) { +				struct sctphdr *sctp = sctp_hdr(skb); +				key->tp.src = sctp->source; +				key->tp.dst = sctp->dest; +			} +		} else if (key->ip.proto == IPPROTO_ICMP) { +			if (icmphdr_ok(skb)) { +				struct icmphdr *icmp = icmp_hdr(skb); +				/* The ICMP type and code fields use the 16-bit +				 * transport port fields, so we need to store +				 * them in 16-bit network byte order. */ +				key->tp.src = htons(icmp->type); +				key->tp.dst = htons(icmp->code); +			} +		} + +	} else if ((key->eth.type == htons(ETH_P_ARP) || +		   key->eth.type == htons(ETH_P_RARP)) && arphdr_ok(skb)) { +		struct arp_eth_header *arp; + +		arp = (struct arp_eth_header *)skb_network_header(skb); + +		if (arp->ar_hrd == htons(ARPHRD_ETHER) +				&& arp->ar_pro == htons(ETH_P_IP) +				&& arp->ar_hln == ETH_ALEN +				&& arp->ar_pln == 4) { + +			/* We only match on the lower 8 bits of the opcode. */ +			if (ntohs(arp->ar_op) <= 0xff) +				key->ip.proto = ntohs(arp->ar_op); +			memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src)); +			memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst)); +			ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha); +			ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha); +		} +	} else if (key->eth.type == htons(ETH_P_IPV6)) { +		int nh_len;             /* IPv6 Header + Extensions */ + +		nh_len = parse_ipv6hdr(skb, key); +		if (unlikely(nh_len < 0)) { +			if (nh_len == -EINVAL) { +				skb->transport_header = skb->network_header; +				error = 0; +			} else { +				error = nh_len; +			} +			return error; +		} + +		if (key->ip.frag == OVS_FRAG_TYPE_LATER) +			return 0; +		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) +			key->ip.frag = OVS_FRAG_TYPE_FIRST; + +		/* Transport layer. */ +		if (key->ip.proto == NEXTHDR_TCP) { +			if (tcphdr_ok(skb)) { +				struct tcphdr *tcp = tcp_hdr(skb); +				key->tp.src = tcp->source; +				key->tp.dst = tcp->dest; +				key->tp.flags = TCP_FLAGS_BE16(tcp); +			} +		} else if (key->ip.proto == NEXTHDR_UDP) { +			if (udphdr_ok(skb)) { +				struct udphdr *udp = udp_hdr(skb); +				key->tp.src = udp->source; +				key->tp.dst = udp->dest; +			} +		} else if (key->ip.proto == NEXTHDR_SCTP) { +			if (sctphdr_ok(skb)) { +				struct sctphdr *sctp = sctp_hdr(skb); +				key->tp.src = sctp->source; +				key->tp.dst = sctp->dest; +			} +		} else if (key->ip.proto == NEXTHDR_ICMP) { +			if (icmp6hdr_ok(skb)) { +				error = parse_icmpv6(skb, key, nh_len); +				if (error) +					return error; +			} +		} +	} + +	return 0; +}  | 
