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linux/linux-5.18.11/net/openvswitch/flow.c

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2024-03-22 18:12:32 +00:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2007-2014 Nicira, Inc.
*/
#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/cpumask.h>
#include <linux/if_arp.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/mpls.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/mpls.h>
#include <net/ndisc.h>
#include <net/nsh.h>
#include <net/pkt_cls.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include "conntrack.h"
#include "datapath.h"
#include "flow.h"
#include "flow_netlink.h"
#include "vport.h"
u64 ovs_flow_used_time(unsigned long flow_jiffies)
{
struct timespec64 cur_ts;
u64 cur_ms, idle_ms;
ktime_get_ts64(&cur_ts);
idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
cur_ms = (u64)(u32)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 sw_flow_stats *stats;
unsigned int cpu = smp_processor_id();
int len = skb->len + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
stats = rcu_dereference(flow->stats[cpu]);
/* Check if already have CPU-specific stats. */
if (likely(stats)) {
spin_lock(&stats->lock);
/* Mark if we write on the pre-allocated stats. */
if (cpu == 0 && unlikely(flow->stats_last_writer != cpu))
flow->stats_last_writer = cpu;
} else {
stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */
spin_lock(&stats->lock);
/* If the current CPU is the only writer on the
* pre-allocated stats keep using them.
*/
if (unlikely(flow->stats_last_writer != cpu)) {
/* A previous locker may have already allocated the
* stats, so we need to check again. If CPU-specific
* stats were already allocated, we update the pre-
* allocated stats as we have already locked them.
*/
if (likely(flow->stats_last_writer != -1) &&
likely(!rcu_access_pointer(flow->stats[cpu]))) {
/* Try to allocate CPU-specific stats. */
struct sw_flow_stats *new_stats;
new_stats =
kmem_cache_alloc_node(flow_stats_cache,
GFP_NOWAIT |
__GFP_THISNODE |
__GFP_NOWARN |
__GFP_NOMEMALLOC,
numa_node_id());
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[cpu],
new_stats);
cpumask_set_cpu(cpu, &flow->cpu_used_mask);
goto unlock;
}
}
flow->stats_last_writer = cpu;
}
}
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 cpu;
*used = 0;
*tcp_flags = 0;
memset(ovs_stats, 0, sizeof(*ovs_stats));
/* We open code this to make sure cpu 0 is always considered */
for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
struct sw_flow_stats *stats = rcu_dereference_ovsl(flow->stats[cpu]);
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 cpu;
/* We open code this to make sure cpu 0 is always considered */
for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
struct sw_flow_stats *stats = ovsl_dereference(flow->stats[cpu]);
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));
}
/**
* get_ipv6_ext_hdrs() - Parses packet and sets IPv6 extension header flags.
*
* @skb: buffer where extension header data starts in packet
* @nh: ipv6 header
* @ext_hdrs: flags are stored here
*
* OFPIEH12_UNREP is set if more than one of a given IPv6 extension header
* is unexpectedly encountered. (Two destination options headers may be
* expected and would not cause this bit to be set.)
*
* OFPIEH12_UNSEQ is set if IPv6 extension headers were not in the order
* preferred (but not required) by RFC 2460:
*
* When more than one extension header is used in the same packet, it is
* recommended that those headers appear in the following order:
* IPv6 header
* Hop-by-Hop Options header
* Destination Options header
* Routing header
* Fragment header
* Authentication header
* Encapsulating Security Payload header
* Destination Options header
* upper-layer header
*/
static void get_ipv6_ext_hdrs(struct sk_buff *skb, struct ipv6hdr *nh,
u16 *ext_hdrs)
{
u8 next_type = nh->nexthdr;
unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
int dest_options_header_count = 0;
*ext_hdrs = 0;
while (ipv6_ext_hdr(next_type)) {
struct ipv6_opt_hdr _hdr, *hp;
switch (next_type) {
case IPPROTO_NONE:
*ext_hdrs |= OFPIEH12_NONEXT;
/* stop parsing */
return;
case IPPROTO_ESP:
if (*ext_hdrs & OFPIEH12_ESP)
*ext_hdrs |= OFPIEH12_UNREP;
if ((*ext_hdrs & ~(OFPIEH12_HOP | OFPIEH12_DEST |
OFPIEH12_ROUTER | IPPROTO_FRAGMENT |
OFPIEH12_AUTH | OFPIEH12_UNREP)) ||
dest_options_header_count >= 2) {
*ext_hdrs |= OFPIEH12_UNSEQ;
}
*ext_hdrs |= OFPIEH12_ESP;
break;
case IPPROTO_AH:
if (*ext_hdrs & OFPIEH12_AUTH)
*ext_hdrs |= OFPIEH12_UNREP;
if ((*ext_hdrs &
~(OFPIEH12_HOP | OFPIEH12_DEST | OFPIEH12_ROUTER |
IPPROTO_FRAGMENT | OFPIEH12_UNREP)) ||
dest_options_header_count >= 2) {
*ext_hdrs |= OFPIEH12_UNSEQ;
}
*ext_hdrs |= OFPIEH12_AUTH;
break;
case IPPROTO_DSTOPTS:
if (dest_options_header_count == 0) {
if (*ext_hdrs &
~(OFPIEH12_HOP | OFPIEH12_UNREP))
*ext_hdrs |= OFPIEH12_UNSEQ;
*ext_hdrs |= OFPIEH12_DEST;
} else if (dest_options_header_count == 1) {
if (*ext_hdrs &
~(OFPIEH12_HOP | OFPIEH12_DEST |
OFPIEH12_ROUTER | OFPIEH12_FRAG |
OFPIEH12_AUTH | OFPIEH12_ESP |
OFPIEH12_UNREP)) {
*ext_hdrs |= OFPIEH12_UNSEQ;
}
} else {
*ext_hdrs |= OFPIEH12_UNREP;
}
dest_options_header_count++;
break;
case IPPROTO_FRAGMENT:
if (*ext_hdrs & OFPIEH12_FRAG)
*ext_hdrs |= OFPIEH12_UNREP;
if ((*ext_hdrs & ~(OFPIEH12_HOP |
OFPIEH12_DEST |
OFPIEH12_ROUTER |
OFPIEH12_UNREP)) ||
dest_options_header_count >= 2) {
*ext_hdrs |= OFPIEH12_UNSEQ;
}
*ext_hdrs |= OFPIEH12_FRAG;
break;
case IPPROTO_ROUTING:
if (*ext_hdrs & OFPIEH12_ROUTER)
*ext_hdrs |= OFPIEH12_UNREP;
if ((*ext_hdrs & ~(OFPIEH12_HOP |
OFPIEH12_DEST |
OFPIEH12_UNREP)) ||
dest_options_header_count >= 2) {
*ext_hdrs |= OFPIEH12_UNSEQ;
}
*ext_hdrs |= OFPIEH12_ROUTER;
break;
case IPPROTO_HOPOPTS:
if (*ext_hdrs & OFPIEH12_HOP)
*ext_hdrs |= OFPIEH12_UNREP;
/* OFPIEH12_HOP is set to 1 if a hop-by-hop IPv6
* extension header is present as the first
* extension header in the packet.
*/
if (*ext_hdrs == 0)
*ext_hdrs |= OFPIEH12_HOP;
else
*ext_hdrs |= OFPIEH12_UNSEQ;
break;
default:
return;
}
hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
if (!hp)
break;
next_type = hp->nexthdr;
start += ipv6_optlen(hp);
}
}
static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
{
unsigned short frag_off;
unsigned int payload_ofs = 0;
unsigned int nh_ofs = skb_network_offset(skb);
unsigned int nh_len;
struct ipv6hdr *nh;
int err, nexthdr, flags = 0;
err = check_header(skb, nh_ofs + sizeof(*nh));
if (unlikely(err))
return err;
nh = ipv6_hdr(skb);
get_ipv6_ext_hdrs(skb, nh, &key->ipv6.exthdrs);
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;
nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags);
if (flags & IP6_FH_F_FRAG) {
if (frag_off) {
key->ip.frag = OVS_FRAG_TYPE_LATER;
key->ip.proto = NEXTHDR_FRAGMENT;
return 0;
}
key->ip.frag = OVS_FRAG_TYPE_FIRST;
} else {
key->ip.frag = OVS_FRAG_TYPE_NONE;
}
/* Delayed handling of error in ipv6_find_hdr() as it
* always sets flags and frag_off to a valid value which may be
* used to set key->ip.frag above.
*/
if (unlikely(nexthdr < 0))
return -EPROTO;
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));
}
/**
* parse_vlan_tag - Parse vlan tag from vlan header.
* @skb: skb containing frame to parse
* @key_vh: pointer to parsed vlan tag
* @untag_vlan: should the vlan header be removed from the frame
*
* Return: ERROR on memory error.
* %0 if it encounters a non-vlan or incomplete packet.
* %1 after successfully parsing vlan tag.
*/
static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh,
bool untag_vlan)
{
struct vlan_head *vh = (struct vlan_head *)skb->data;
if (likely(!eth_type_vlan(vh->tpid)))
return 0;
if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16)))
return 0;
if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) +
sizeof(__be16))))
return -ENOMEM;
vh = (struct vlan_head *)skb->data;
key_vh->tci = vh->tci | htons(VLAN_CFI_MASK);
key_vh->tpid = vh->tpid;
if (unlikely(untag_vlan)) {
int offset = skb->data - skb_mac_header(skb);
u16 tci;
int err;
__skb_push(skb, offset);
err = __skb_vlan_pop(skb, &tci);
__skb_pull(skb, offset);
if (err)
return err;
__vlan_hwaccel_put_tag(skb, key_vh->tpid, tci);
} else {
__skb_pull(skb, sizeof(struct vlan_head));
}
return 1;
}
static void clear_vlan(struct sw_flow_key *key)
{
key->eth.vlan.tci = 0;
key->eth.vlan.tpid = 0;
key->eth.cvlan.tci = 0;
key->eth.cvlan.tpid = 0;
}
static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
{
int res;
if (skb_vlan_tag_present(skb)) {
key->eth.vlan.tci = htons(skb->vlan_tci) | htons(VLAN_CFI_MASK);
key->eth.vlan.tpid = skb->vlan_proto;
} else {
/* Parse outer vlan tag in the non-accelerated case. */
res = parse_vlan_tag(skb, &key->eth.vlan, true);
if (res <= 0)
return res;
}
/* Parse inner vlan tag. */
res = parse_vlan_tag(skb, &key->eth.cvlan, false);
if (res <= 0)
return res;
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 (eth_proto_is_802_3(proto))
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 (eth_proto_is_802_3(llc->ethertype))
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;
}
static int parse_nsh(struct sk_buff *skb, struct sw_flow_key *key)
{
struct nshhdr *nh;
unsigned int nh_ofs = skb_network_offset(skb);
u8 version, length;
int err;
err = check_header(skb, nh_ofs + NSH_BASE_HDR_LEN);
if (unlikely(err))
return err;
nh = nsh_hdr(skb);
version = nsh_get_ver(nh);
length = nsh_hdr_len(nh);
if (version != 0)
return -EINVAL;
err = check_header(skb, nh_ofs + length);
if (unlikely(err))
return err;
nh = nsh_hdr(skb);
key->nsh.base.flags = nsh_get_flags(nh);
key->nsh.base.ttl = nsh_get_ttl(nh);
key->nsh.base.mdtype = nh->mdtype;
key->nsh.base.np = nh->np;
key->nsh.base.path_hdr = nh->path_hdr;
switch (key->nsh.base.mdtype) {
case NSH_M_TYPE1:
if (length != NSH_M_TYPE1_LEN)
return -EINVAL;
memcpy(key->nsh.context, nh->md1.context,
sizeof(nh->md1));
break;
case NSH_M_TYPE2:
memset(key->nsh.context, 0,
sizeof(nh->md1));
break;
default:
return -EINVAL;
}
return 0;
}
/**
* key_extract_l3l4 - extracts L3/L4 header information.
* @skb: sk_buff that contains the frame, with skb->data pointing to the
* L3 header
* @key: output flow key
*
* Return: %0 if successful, otherwise a negative errno value.
*/
static int key_extract_l3l4(struct sk_buff *skb, struct sw_flow_key *key)
{
int error;
/* 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;
memset(&key->tp, 0, sizeof(key->tp));
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)) {
u8 label_count = 1;
memset(&key->mpls, 0, sizeof(key->mpls));
skb_set_inner_network_header(skb, skb->mac_len);
while (1) {
__be32 lse;
error = check_header(skb, skb->mac_len +
label_count * MPLS_HLEN);
if (unlikely(error))
return 0;
memcpy(&lse, skb_inner_network_header(skb), MPLS_HLEN);
if (label_count <= MPLS_LABEL_DEPTH)
memcpy(&key->mpls.lse[label_count - 1], &lse,
MPLS_HLEN);
skb_set_inner_network_header(skb, skb->mac_len +
label_count * MPLS_HLEN);
if (lse & htonl(MPLS_LS_S_MASK))
break;
label_count++;
}
if (label_count > MPLS_LABEL_DEPTH)
label_count = MPLS_LABEL_DEPTH;
key->mpls.num_labels_mask = GENMASK(label_count - 1, 0);
} 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)) {
switch (nh_len) {
case -EINVAL:
memset(&key->ip, 0, sizeof(key->ip));
memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr));
fallthrough;
case -EPROTO:
skb->transport_header = skb->network_header;
error = 0;
break;
default:
error = nh_len;
}
return error;
}
if (key->ip.frag == OVS_FRAG_TYPE_LATER) {
memset(&key->tp, 0, sizeof(key->tp));
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));
}
}
} else if (key->eth.type == htons(ETH_P_NSH)) {
error = parse_nsh(skb, key);
if (error)
return error;
}
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.
*
* Initializes @skb header fields as follows:
*
* - skb->mac_header: the L2 header.
*
* - skb->network_header: just past the L2 header, or just past the
* VLAN header, to the first byte of the L2 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.
*
* - skb->protocol: the type of the data starting at skb->network_header.
* Equals to key->eth.type.
*
* Return: %0 if successful, otherwise a negative errno value.
*/
static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
{
struct ethhdr *eth;
/* Flags are always used as part of stats */
key->tp.flags = 0;
skb_reset_mac_header(skb);
/* Link layer. */
clear_vlan(key);
if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) {
if (unlikely(eth_type_vlan(skb->protocol)))
return -EINVAL;
skb_reset_network_header(skb);
key->eth.type = skb->protocol;
} else {
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 (unlikely(parse_vlan(skb, key)))
return -ENOMEM;
key->eth.type = parse_ethertype(skb);
if (unlikely(key->eth.type == htons(0)))
return -ENOMEM;
/* Multiple tagged packets need to retain TPID to satisfy
* skb_vlan_pop(), which will later shift the ethertype into
* skb->protocol.
*/
if (key->eth.cvlan.tci & htons(VLAN_CFI_MASK))
skb->protocol = key->eth.cvlan.tpid;
else
skb->protocol = key->eth.type;
skb_reset_network_header(skb);
__skb_push(skb, skb->data - skb_mac_header(skb));
}
skb_reset_mac_len(skb);
/* Fill out L3/L4 key info, if any */
return key_extract_l3l4(skb, key);
}
/* In the case of conntrack fragment handling it expects L3 headers,
* add a helper.
*/
int ovs_flow_key_update_l3l4(struct sk_buff *skb, struct sw_flow_key *key)
{
return key_extract_l3l4(skb, key);
}
int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key)
{
int res;
res = key_extract(skb, key);
if (!res)
key->mac_proto &= ~SW_FLOW_KEY_INVALID;
return res;
}
static int key_extract_mac_proto(struct sk_buff *skb)
{
switch (skb->dev->type) {
case ARPHRD_ETHER:
return MAC_PROTO_ETHERNET;
case ARPHRD_NONE:
if (skb->protocol == htons(ETH_P_TEB))
return MAC_PROTO_ETHERNET;
return MAC_PROTO_NONE;
}
WARN_ON_ONCE(1);
return -EINVAL;
}
int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
struct sk_buff *skb, struct sw_flow_key *key)
{
#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
struct tc_skb_ext *tc_ext;
#endif
bool post_ct = false, post_ct_snat = false, post_ct_dnat = false;
int res, err;
u16 zone = 0;
/* Extract metadata from packet. */
if (tun_info) {
key->tun_proto = ip_tunnel_info_af(tun_info);
memcpy(&key->tun_key, &tun_info->key, sizeof(key->tun_key));
if (tun_info->options_len) {
BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) *
8)) - 1
> sizeof(key->tun_opts));
ip_tunnel_info_opts_get(TUN_METADATA_OPTS(key, tun_info->options_len),
tun_info);
key->tun_opts_len = tun_info->options_len;
} else {
key->tun_opts_len = 0;
}
} else {
key->tun_proto = 0;
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;
res = key_extract_mac_proto(skb);
if (res < 0)
return res;
key->mac_proto = res;
#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
if (tc_skb_ext_tc_enabled()) {
tc_ext = skb_ext_find(skb, TC_SKB_EXT);
key->recirc_id = tc_ext ? tc_ext->chain : 0;
OVS_CB(skb)->mru = tc_ext ? tc_ext->mru : 0;
post_ct = tc_ext ? tc_ext->post_ct : false;
post_ct_snat = post_ct ? tc_ext->post_ct_snat : false;
post_ct_dnat = post_ct ? tc_ext->post_ct_dnat : false;
zone = post_ct ? tc_ext->zone : 0;
} else {
key->recirc_id = 0;
}
#else
key->recirc_id = 0;
#endif
err = key_extract(skb, key);
if (!err) {
ovs_ct_fill_key(skb, key, post_ct); /* Must be after key_extract(). */
if (post_ct) {
if (!skb_get_nfct(skb)) {
key->ct_zone = zone;
} else {
if (!post_ct_dnat)
key->ct_state &= ~OVS_CS_F_DST_NAT;
if (!post_ct_snat)
key->ct_state &= ~OVS_CS_F_SRC_NAT;
}
}
}
return err;
}
int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr,
struct sk_buff *skb,
struct sw_flow_key *key, bool log)
{
const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
u64 attrs = 0;
int err;
err = parse_flow_nlattrs(attr, a, &attrs, log);
if (err)
return -EINVAL;
/* Extract metadata from netlink attributes. */
err = ovs_nla_get_flow_metadata(net, a, attrs, key, log);
if (err)
return err;
/* key_extract assumes that skb->protocol is set-up for
* layer 3 packets which is the case for other callers,
* in particular packets received from the network stack.
* Here the correct value can be set from the metadata
* extracted above.
* For L2 packet key eth type would be zero. skb protocol
* would be set to correct value later during key-extact.
*/
skb->protocol = key->eth.type;
err = key_extract(skb, key);
if (err)
return err;
/* Check that we have conntrack original direction tuple metadata only
* for packets for which it makes sense. Otherwise the key may be
* corrupted due to overlapping key fields.
*/
if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4) &&
key->eth.type != htons(ETH_P_IP))
return -EINVAL;
if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6) &&
(key->eth.type != htons(ETH_P_IPV6) ||
sw_flow_key_is_nd(key)))
return -EINVAL;
return 0;
}