From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/openvswitch/flow.c | 730 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 730 insertions(+) create mode 100644 net/openvswitch/flow.c (limited to 'net/openvswitch/flow.c') diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c new file mode 100644 index 000000000..2dacc7b5a --- /dev/null +++ b/net/openvswitch/flow.c @@ -0,0 +1,730 @@ +/* + * Copyright (c) 2007-2014 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "datapath.h" +#include "flow.h" +#include "flow_netlink.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, + const struct sk_buff *skb) +{ + struct flow_stats *stats; + int node = numa_node_id(); + int len = skb->len + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0); + + 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_access_pointer(flow->stats[node]))) { + /* Try to allocate node-specific stats. */ + struct flow_stats *new_stats; + + new_stats = + kmem_cache_alloc_node(flow_stats_cache, + GFP_NOWAIT | + __GFP_THISNODE | + __GFP_NOWARN | + __GFP_NOMEMALLOC, + node); + if (likely(new_stats)) { + new_stats->used = jiffies; + new_stats->packet_count = 1; + new_stats->byte_count = 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 += 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; + } else { + key->ip.frag = OVS_FRAG_TYPE_NONE; + } + + 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); + memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd)); + + 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; +} + +/** + * key_extract - extracts a flow key from an Ethernet frame. + * @skb: sk_buff that contains the frame, with skb->data pointing to the + * Ethernet header + * @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. + */ +static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) +{ + int error; + struct ethhdr *eth; + + /* Flags are always used as part of stats */ + key->tp.flags = 0; + + 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. + */ + + key->eth.tci = 0; + if (skb_vlan_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_reset_mac_len(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)) { + memset(&key->ip, 0, sizeof(key->ip)); + memset(&key->ipv4, 0, sizeof(key->ipv4)); + 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; + else + key->ip.frag = OVS_FRAG_TYPE_NONE; + + /* 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 { + memset(&key->tp, 0, sizeof(key->tp)); + } + + } 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 { + memset(&key->tp, 0, sizeof(key->tp)); + } + } 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 { + memset(&key->tp, 0, sizeof(key->tp)); + } + } 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 { + memset(&key->tp, 0, sizeof(key->tp)); + } + } + + } else if (key->eth.type == htons(ETH_P_ARP) || + key->eth.type == htons(ETH_P_RARP)) { + struct arp_eth_header *arp; + bool arp_available = arphdr_ok(skb); + + arp = (struct arp_eth_header *)skb_network_header(skb); + + if (arp_available && + 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); + else + key->ip.proto = 0; + + 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 { + memset(&key->ip, 0, sizeof(key->ip)); + memset(&key->ipv4, 0, sizeof(key->ipv4)); + } + } else if (eth_p_mpls(key->eth.type)) { + size_t stack_len = MPLS_HLEN; + + /* In the presence of an MPLS label stack the end of the L2 + * header and the beginning of the L3 header differ. + * + * Advance network_header to the beginning of the L3 + * header. mac_len corresponds to the end of the L2 header. + */ + while (1) { + __be32 lse; + + error = check_header(skb, skb->mac_len + stack_len); + if (unlikely(error)) + return 0; + + memcpy(&lse, skb_network_header(skb), MPLS_HLEN); + + if (stack_len == MPLS_HLEN) + memcpy(&key->mpls.top_lse, &lse, MPLS_HLEN); + + skb_set_network_header(skb, skb->mac_len + stack_len); + if (lse & htonl(MPLS_LS_S_MASK)) + break; + + stack_len += MPLS_HLEN; + } + } 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)) { + memset(&key->ip, 0, sizeof(key->ip)); + memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr)); + 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 { + memset(&key->tp, 0, sizeof(key->tp)); + } + } 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 { + memset(&key->tp, 0, sizeof(key->tp)); + } + } 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 { + memset(&key->tp, 0, sizeof(key->tp)); + } + } else if (key->ip.proto == NEXTHDR_ICMP) { + if (icmp6hdr_ok(skb)) { + error = parse_icmpv6(skb, key, nh_len); + if (error) + return error; + } else { + memset(&key->tp, 0, sizeof(key->tp)); + } + } + } + return 0; +} + +int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key) +{ + return key_extract(skb, key); +} + +int ovs_flow_key_extract(const struct ovs_tunnel_info *tun_info, + struct sk_buff *skb, struct sw_flow_key *key) +{ + /* Extract metadata from packet. */ + if (tun_info) { + memcpy(&key->tun_key, &tun_info->tunnel, sizeof(key->tun_key)); + + if (tun_info->options) { + BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) * + 8)) - 1 + > sizeof(key->tun_opts)); + memcpy(TUN_METADATA_OPTS(key, tun_info->options_len), + tun_info->options, tun_info->options_len); + key->tun_opts_len = tun_info->options_len; + } else { + key->tun_opts_len = 0; + } + } else { + key->tun_opts_len = 0; + memset(&key->tun_key, 0, sizeof(key->tun_key)); + } + + key->phy.priority = skb->priority; + key->phy.in_port = OVS_CB(skb)->input_vport->port_no; + key->phy.skb_mark = skb->mark; + key->ovs_flow_hash = 0; + key->recirc_id = 0; + + return key_extract(skb, key); +} + +int ovs_flow_key_extract_userspace(const struct nlattr *attr, + struct sk_buff *skb, + struct sw_flow_key *key, bool log) +{ + int err; + + memset(key, 0, OVS_SW_FLOW_KEY_METADATA_SIZE); + + /* Extract metadata from netlink attributes. */ + err = ovs_nla_get_flow_metadata(attr, key, log); + if (err) + return err; + + return key_extract(skb, key); +} -- cgit v1.2.3-54-g00ecf