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linux/net/openvswitch/actions.c
Jarno Rajahalme 9dd7f8907c openvswitch: Add original direction conntrack tuple to sw_flow_key. 
Add the fields of the conntrack original direction 5-tuple to struct
sw_flow_key.  The new fields are initially marked as non-existent, and
are populated whenever a conntrack action is executed and either finds
or generates a conntrack entry.  This means that these fields exist
for all packets that were not rejected by conntrack as untrackable.

The original tuple fields in the sw_flow_key are filled from the
original direction tuple of the conntrack entry relating to the
current packet, or from the original direction tuple of the master
conntrack entry, if the current conntrack entry has a master.
Generally, expected connections of connections having an assigned
helper (e.g., FTP), have a master conntrack entry.

The main purpose of the new conntrack original tuple fields is to
allow matching on them for policy decision purposes, with the premise
that the admissibility of tracked connections reply packets (as well
as original direction packets), and both direction packets of any
related connections may be based on ACL rules applying to the master
connection's original direction 5-tuple.  This also makes it easier to
make policy decisions when the actual packet headers might have been
transformed by NAT, as the original direction 5-tuple represents the
packet headers before any such transformation.

When using the original direction 5-tuple the admissibility of return
and/or related packets need not be based on the mere existence of a
conntrack entry, allowing separation of admission policy from the
established conntrack state.  While existence of a conntrack entry is
required for admission of the return or related packets, policy
changes can render connections that were initially admitted to be
rejected or dropped afterwards.  If the admission of the return and
related packets was based on mere conntrack state (e.g., connection
being in an established state), a policy change that would make the
connection rejected or dropped would need to find and delete all
conntrack entries affected by such a change.  When using the original
direction 5-tuple matching the affected conntrack entries can be
allowed to time out instead, as the established state of the
connection would not need to be the basis for packet admission any
more.

It should be noted that the directionality of related connections may
be the same or different than that of the master connection, and
neither the original direction 5-tuple nor the conntrack state bits
carry this information.  If needed, the directionality of the master
connection can be stored in master's conntrack mark or labels, which
are automatically inherited by the expected related connections.

The fact that neither ARP nor ND packets are trackable by conntrack
allows mutual exclusion between ARP/ND and the new conntrack original
tuple fields.  Hence, the IP addresses are overlaid in union with ARP
and ND fields.  This allows the sw_flow_key to not grow much due to
this patch, but it also means that we must be careful to never use the
new key fields with ARP or ND packets.  ARP is easy to distinguish and
keep mutually exclusive based on the ethernet type, but ND being an
ICMPv6 protocol requires a bit more attention.

Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-09 22:59:34 -05:00

1341 lines
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/*
* 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
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/openvswitch.h>
#include <linux/netfilter_ipv6.h>
#include <linux/sctp.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/in6.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include <net/dst.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ip6_fib.h>
#include <net/checksum.h>
#include <net/dsfield.h>
#include <net/mpls.h>
#include <net/sctp/checksum.h>
#include "datapath.h"
#include "flow.h"
#include "conntrack.h"
#include "vport.h"
static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key,
const struct nlattr *attr, int len);
struct deferred_action {
struct sk_buff *skb;
const struct nlattr *actions;
/* Store pkt_key clone when creating deferred action. */
struct sw_flow_key pkt_key;
};
#define MAX_L2_LEN (VLAN_ETH_HLEN + 3 * MPLS_HLEN)
struct ovs_frag_data {
unsigned long dst;
struct vport *vport;
struct ovs_skb_cb cb;
__be16 inner_protocol;
u16 network_offset; /* valid only for MPLS */
u16 vlan_tci;
__be16 vlan_proto;
unsigned int l2_len;
u8 mac_proto;
u8 l2_data[MAX_L2_LEN];
};
static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage);
#define DEFERRED_ACTION_FIFO_SIZE 10
#define OVS_RECURSION_LIMIT 5
#define OVS_DEFERRED_ACTION_THRESHOLD (OVS_RECURSION_LIMIT - 2)
struct action_fifo {
int head;
int tail;
/* Deferred action fifo queue storage. */
struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
};
struct recirc_keys {
struct sw_flow_key key[OVS_DEFERRED_ACTION_THRESHOLD];
};
static struct action_fifo __percpu *action_fifos;
static struct recirc_keys __percpu *recirc_keys;
static DEFINE_PER_CPU(int, exec_actions_level);
static void action_fifo_init(struct action_fifo *fifo)
{
fifo->head = 0;
fifo->tail = 0;
}
static bool action_fifo_is_empty(const struct action_fifo *fifo)
{
return (fifo->head == fifo->tail);
}
static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
{
if (action_fifo_is_empty(fifo))
return NULL;
return &fifo->fifo[fifo->tail++];
}
static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
{
if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
return NULL;
return &fifo->fifo[fifo->head++];
}
/* Return true if fifo is not full */
static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
const struct sw_flow_key *key,
const struct nlattr *attr)
{
struct action_fifo *fifo;
struct deferred_action *da;
fifo = this_cpu_ptr(action_fifos);
da = action_fifo_put(fifo);
if (da) {
da->skb = skb;
da->actions = attr;
da->pkt_key = *key;
}
return da;
}
static void invalidate_flow_key(struct sw_flow_key *key)
{
key->mac_proto |= SW_FLOW_KEY_INVALID;
}
static bool is_flow_key_valid(const struct sw_flow_key *key)
{
return !(key->mac_proto & SW_FLOW_KEY_INVALID);
}
static void update_ethertype(struct sk_buff *skb, struct ethhdr *hdr,
__be16 ethertype)
{
if (skb->ip_summed == CHECKSUM_COMPLETE) {
__be16 diff[] = { ~(hdr->h_proto), ethertype };
skb->csum = ~csum_partial((char *)diff, sizeof(diff),
~skb->csum);
}
hdr->h_proto = ethertype;
}
static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
const struct ovs_action_push_mpls *mpls)
{
struct mpls_shim_hdr *new_mpls_lse;
/* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */
if (skb->encapsulation)
return -ENOTSUPP;
if (skb_cow_head(skb, MPLS_HLEN) < 0)
return -ENOMEM;
if (!skb->inner_protocol) {
skb_set_inner_network_header(skb, skb->mac_len);
skb_set_inner_protocol(skb, skb->protocol);
}
skb_push(skb, MPLS_HLEN);
memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
skb->mac_len);
skb_reset_mac_header(skb);
skb_set_network_header(skb, skb->mac_len);
new_mpls_lse = mpls_hdr(skb);
new_mpls_lse->label_stack_entry = mpls->mpls_lse;
skb_postpush_rcsum(skb, new_mpls_lse, MPLS_HLEN);
if (ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET)
update_ethertype(skb, eth_hdr(skb), mpls->mpls_ethertype);
skb->protocol = mpls->mpls_ethertype;
invalidate_flow_key(key);
return 0;
}
static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
const __be16 ethertype)
{
int err;
err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
if (unlikely(err))
return err;
skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN);
memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
skb->mac_len);
__skb_pull(skb, MPLS_HLEN);
skb_reset_mac_header(skb);
skb_set_network_header(skb, skb->mac_len);
if (ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET) {
struct ethhdr *hdr;
/* mpls_hdr() is used to locate the ethertype field correctly in the
* presence of VLAN tags.
*/
hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN);
update_ethertype(skb, hdr, ethertype);
}
if (eth_p_mpls(skb->protocol))
skb->protocol = ethertype;
invalidate_flow_key(key);
return 0;
}
static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
const __be32 *mpls_lse, const __be32 *mask)
{
struct mpls_shim_hdr *stack;
__be32 lse;
int err;
err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
if (unlikely(err))
return err;
stack = mpls_hdr(skb);
lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);
if (skb->ip_summed == CHECKSUM_COMPLETE) {
__be32 diff[] = { ~(stack->label_stack_entry), lse };
skb->csum = ~csum_partial((char *)diff, sizeof(diff),
~skb->csum);
}
stack->label_stack_entry = lse;
flow_key->mpls.top_lse = lse;
return 0;
}
static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
{
int err;
err = skb_vlan_pop(skb);
if (skb_vlan_tag_present(skb)) {
invalidate_flow_key(key);
} else {
key->eth.vlan.tci = 0;
key->eth.vlan.tpid = 0;
}
return err;
}
static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
const struct ovs_action_push_vlan *vlan)
{
if (skb_vlan_tag_present(skb)) {
invalidate_flow_key(key);
} else {
key->eth.vlan.tci = vlan->vlan_tci;
key->eth.vlan.tpid = vlan->vlan_tpid;
}
return skb_vlan_push(skb, vlan->vlan_tpid,
ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
}
/* 'src' is already properly masked. */
static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
{
u16 *dst = (u16 *)dst_;
const u16 *src = (const u16 *)src_;
const u16 *mask = (const u16 *)mask_;
OVS_SET_MASKED(dst[0], src[0], mask[0]);
OVS_SET_MASKED(dst[1], src[1], mask[1]);
OVS_SET_MASKED(dst[2], src[2], mask[2]);
}
static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
const struct ovs_key_ethernet *key,
const struct ovs_key_ethernet *mask)
{
int err;
err = skb_ensure_writable(skb, ETH_HLEN);
if (unlikely(err))
return err;
skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
mask->eth_src);
ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
mask->eth_dst);
skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
return 0;
}
/* pop_eth does not support VLAN packets as this action is never called
* for them.
*/
static int pop_eth(struct sk_buff *skb, struct sw_flow_key *key)
{
skb_pull_rcsum(skb, ETH_HLEN);
skb_reset_mac_header(skb);
skb_reset_mac_len(skb);
/* safe right before invalidate_flow_key */
key->mac_proto = MAC_PROTO_NONE;
invalidate_flow_key(key);
return 0;
}
static int push_eth(struct sk_buff *skb, struct sw_flow_key *key,
const struct ovs_action_push_eth *ethh)
{
struct ethhdr *hdr;
/* Add the new Ethernet header */
if (skb_cow_head(skb, ETH_HLEN) < 0)
return -ENOMEM;
skb_push(skb, ETH_HLEN);
skb_reset_mac_header(skb);
skb_reset_mac_len(skb);
hdr = eth_hdr(skb);
ether_addr_copy(hdr->h_source, ethh->addresses.eth_src);
ether_addr_copy(hdr->h_dest, ethh->addresses.eth_dst);
hdr->h_proto = skb->protocol;
skb_postpush_rcsum(skb, hdr, ETH_HLEN);
/* safe right before invalidate_flow_key */
key->mac_proto = MAC_PROTO_ETHERNET;
invalidate_flow_key(key);
return 0;
}
static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
__be32 addr, __be32 new_addr)
{
int transport_len = skb->len - skb_transport_offset(skb);
if (nh->frag_off & htons(IP_OFFSET))
return;
if (nh->protocol == IPPROTO_TCP) {
if (likely(transport_len >= sizeof(struct tcphdr)))
inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
addr, new_addr, true);
} else if (nh->protocol == IPPROTO_UDP) {
if (likely(transport_len >= sizeof(struct udphdr))) {
struct udphdr *uh = udp_hdr(skb);
if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
inet_proto_csum_replace4(&uh->check, skb,
addr, new_addr, true);
if (!uh->check)
uh->check = CSUM_MANGLED_0;
}
}
}
}
static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
__be32 *addr, __be32 new_addr)
{
update_ip_l4_checksum(skb, nh, *addr, new_addr);
csum_replace4(&nh->check, *addr, new_addr);
skb_clear_hash(skb);
*addr = new_addr;
}
static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
__be32 addr[4], const __be32 new_addr[4])
{
int transport_len = skb->len - skb_transport_offset(skb);
if (l4_proto == NEXTHDR_TCP) {
if (likely(transport_len >= sizeof(struct tcphdr)))
inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
addr, new_addr, true);
} else if (l4_proto == NEXTHDR_UDP) {
if (likely(transport_len >= sizeof(struct udphdr))) {
struct udphdr *uh = udp_hdr(skb);
if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
inet_proto_csum_replace16(&uh->check, skb,
addr, new_addr, true);
if (!uh->check)
uh->check = CSUM_MANGLED_0;
}
}
} else if (l4_proto == NEXTHDR_ICMP) {
if (likely(transport_len >= sizeof(struct icmp6hdr)))
inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
skb, addr, new_addr, true);
}
}
static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
const __be32 mask[4], __be32 masked[4])
{
masked[0] = OVS_MASKED(old[0], addr[0], mask[0]);
masked[1] = OVS_MASKED(old[1], addr[1], mask[1]);
masked[2] = OVS_MASKED(old[2], addr[2], mask[2]);
masked[3] = OVS_MASKED(old[3], addr[3], mask[3]);
}
static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
__be32 addr[4], const __be32 new_addr[4],
bool recalculate_csum)
{
if (recalculate_csum)
update_ipv6_checksum(skb, l4_proto, addr, new_addr);
skb_clear_hash(skb);
memcpy(addr, new_addr, sizeof(__be32[4]));
}
static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
{
/* Bits 21-24 are always unmasked, so this retains their values. */
OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
}
static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
u8 mask)
{
new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask);
csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
nh->ttl = new_ttl;
}
static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
const struct ovs_key_ipv4 *key,
const struct ovs_key_ipv4 *mask)
{
struct iphdr *nh;
__be32 new_addr;
int err;
err = skb_ensure_writable(skb, skb_network_offset(skb) +
sizeof(struct iphdr));
if (unlikely(err))
return err;
nh = ip_hdr(skb);
/* Setting an IP addresses is typically only a side effect of
* matching on them in the current userspace implementation, so it
* makes sense to check if the value actually changed.
*/
if (mask->ipv4_src) {
new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);
if (unlikely(new_addr != nh->saddr)) {
set_ip_addr(skb, nh, &nh->saddr, new_addr);
flow_key->ipv4.addr.src = new_addr;
}
}
if (mask->ipv4_dst) {
new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);
if (unlikely(new_addr != nh->daddr)) {
set_ip_addr(skb, nh, &nh->daddr, new_addr);
flow_key->ipv4.addr.dst = new_addr;
}
}
if (mask->ipv4_tos) {
ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
flow_key->ip.tos = nh->tos;
}
if (mask->ipv4_ttl) {
set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
flow_key->ip.ttl = nh->ttl;
}
return 0;
}
static bool is_ipv6_mask_nonzero(const __be32 addr[4])
{
return !!(addr[0] | addr[1] | addr[2] | addr[3]);
}
static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
const struct ovs_key_ipv6 *key,
const struct ovs_key_ipv6 *mask)
{
struct ipv6hdr *nh;
int err;
err = skb_ensure_writable(skb, skb_network_offset(skb) +
sizeof(struct ipv6hdr));
if (unlikely(err))
return err;
nh = ipv6_hdr(skb);
/* Setting an IP addresses is typically only a side effect of
* matching on them in the current userspace implementation, so it
* makes sense to check if the value actually changed.
*/
if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
__be32 *saddr = (__be32 *)&nh->saddr;
__be32 masked[4];
mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);
if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
set_ipv6_addr(skb, flow_key->ip.proto, saddr, masked,
true);
memcpy(&flow_key->ipv6.addr.src, masked,
sizeof(flow_key->ipv6.addr.src));
}
}
if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
unsigned int offset = 0;
int flags = IP6_FH_F_SKIP_RH;
bool recalc_csum = true;
__be32 *daddr = (__be32 *)&nh->daddr;
__be32 masked[4];
mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);
if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
if (ipv6_ext_hdr(nh->nexthdr))
recalc_csum = (ipv6_find_hdr(skb, &offset,
NEXTHDR_ROUTING,
NULL, &flags)
!= NEXTHDR_ROUTING);
set_ipv6_addr(skb, flow_key->ip.proto, daddr, masked,
recalc_csum);
memcpy(&flow_key->ipv6.addr.dst, masked,
sizeof(flow_key->ipv6.addr.dst));
}
}
if (mask->ipv6_tclass) {
ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass);
flow_key->ip.tos = ipv6_get_dsfield(nh);
}
if (mask->ipv6_label) {
set_ipv6_fl(nh, ntohl(key->ipv6_label),
ntohl(mask->ipv6_label));
flow_key->ipv6.label =
*(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
}
if (mask->ipv6_hlimit) {
OVS_SET_MASKED(nh->hop_limit, key->ipv6_hlimit,
mask->ipv6_hlimit);
flow_key->ip.ttl = nh->hop_limit;
}
return 0;
}
/* Must follow skb_ensure_writable() since that can move the skb data. */
static void set_tp_port(struct sk_buff *skb, __be16 *port,
__be16 new_port, __sum16 *check)
{
inet_proto_csum_replace2(check, skb, *port, new_port, false);
*port = new_port;
}
static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
const struct ovs_key_udp *key,
const struct ovs_key_udp *mask)
{
struct udphdr *uh;
__be16 src, dst;
int err;
err = skb_ensure_writable(skb, skb_transport_offset(skb) +
sizeof(struct udphdr));
if (unlikely(err))
return err;
uh = udp_hdr(skb);
/* Either of the masks is non-zero, so do not bother checking them. */
src = OVS_MASKED(uh->source, key->udp_src, mask->udp_src);
dst = OVS_MASKED(uh->dest, key->udp_dst, mask->udp_dst);
if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
if (likely(src != uh->source)) {
set_tp_port(skb, &uh->source, src, &uh->check);
flow_key->tp.src = src;
}
if (likely(dst != uh->dest)) {
set_tp_port(skb, &uh->dest, dst, &uh->check);
flow_key->tp.dst = dst;
}
if (unlikely(!uh->check))
uh->check = CSUM_MANGLED_0;
} else {
uh->source = src;
uh->dest = dst;
flow_key->tp.src = src;
flow_key->tp.dst = dst;
}
skb_clear_hash(skb);
return 0;
}
static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key,
const struct ovs_key_tcp *key,
const struct ovs_key_tcp *mask)
{
struct tcphdr *th;
__be16 src, dst;
int err;
err = skb_ensure_writable(skb, skb_transport_offset(skb) +
sizeof(struct tcphdr));
if (unlikely(err))
return err;
th = tcp_hdr(skb);
src = OVS_MASKED(th->source, key->tcp_src, mask->tcp_src);
if (likely(src != th->source)) {
set_tp_port(skb, &th->source, src, &th->check);
flow_key->tp.src = src;
}
dst = OVS_MASKED(th->dest, key->tcp_dst, mask->tcp_dst);
if (likely(dst != th->dest)) {
set_tp_port(skb, &th->dest, dst, &th->check);
flow_key->tp.dst = dst;
}
skb_clear_hash(skb);
return 0;
}
static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
const struct ovs_key_sctp *key,
const struct ovs_key_sctp *mask)
{
unsigned int sctphoff = skb_transport_offset(skb);
struct sctphdr *sh;
__le32 old_correct_csum, new_csum, old_csum;
int err;
err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
if (unlikely(err))
return err;
sh = sctp_hdr(skb);
old_csum = sh->checksum;
old_correct_csum = sctp_compute_cksum(skb, sctphoff);
sh->source = OVS_MASKED(sh->source, key->sctp_src, mask->sctp_src);
sh->dest = OVS_MASKED(sh->dest, key->sctp_dst, mask->sctp_dst);
new_csum = sctp_compute_cksum(skb, sctphoff);
/* Carry any checksum errors through. */
sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
skb_clear_hash(skb);
flow_key->tp.src = sh->source;
flow_key->tp.dst = sh->dest;
return 0;
}
static int ovs_vport_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage);
struct vport *vport = data->vport;
if (skb_cow_head(skb, data->l2_len) < 0) {
kfree_skb(skb);
return -ENOMEM;
}
__skb_dst_copy(skb, data->dst);
*OVS_CB(skb) = data->cb;
skb->inner_protocol = data->inner_protocol;
skb->vlan_tci = data->vlan_tci;
skb->vlan_proto = data->vlan_proto;
/* Reconstruct the MAC header. */
skb_push(skb, data->l2_len);
memcpy(skb->data, &data->l2_data, data->l2_len);
skb_postpush_rcsum(skb, skb->data, data->l2_len);
skb_reset_mac_header(skb);
if (eth_p_mpls(skb->protocol)) {
skb->inner_network_header = skb->network_header;
skb_set_network_header(skb, data->network_offset);
skb_reset_mac_len(skb);
}
ovs_vport_send(vport, skb, data->mac_proto);
return 0;
}
static unsigned int
ovs_dst_get_mtu(const struct dst_entry *dst)
{
return dst->dev->mtu;
}
static struct dst_ops ovs_dst_ops = {
.family = AF_UNSPEC,
.mtu = ovs_dst_get_mtu,
};
/* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is
* ovs_vport_output(), which is called once per fragmented packet.
*/
static void prepare_frag(struct vport *vport, struct sk_buff *skb,
u16 orig_network_offset, u8 mac_proto)
{
unsigned int hlen = skb_network_offset(skb);
struct ovs_frag_data *data;
data = this_cpu_ptr(&ovs_frag_data_storage);
data->dst = skb->_skb_refdst;
data->vport = vport;
data->cb = *OVS_CB(skb);
data->inner_protocol = skb->inner_protocol;
data->network_offset = orig_network_offset;
data->vlan_tci = skb->vlan_tci;
data->vlan_proto = skb->vlan_proto;
data->mac_proto = mac_proto;
data->l2_len = hlen;
memcpy(&data->l2_data, skb->data, hlen);
memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
skb_pull(skb, hlen);
}
static void ovs_fragment(struct net *net, struct vport *vport,
struct sk_buff *skb, u16 mru,
struct sw_flow_key *key)
{
u16 orig_network_offset = 0;
if (eth_p_mpls(skb->protocol)) {
orig_network_offset = skb_network_offset(skb);
skb->network_header = skb->inner_network_header;
}
if (skb_network_offset(skb) > MAX_L2_LEN) {
OVS_NLERR(1, "L2 header too long to fragment");
goto err;
}
if (key->eth.type == htons(ETH_P_IP)) {
struct dst_entry ovs_dst;
unsigned long orig_dst;
prepare_frag(vport, skb, orig_network_offset,
ovs_key_mac_proto(key));
dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1,
DST_OBSOLETE_NONE, DST_NOCOUNT);
ovs_dst.dev = vport->dev;
orig_dst = skb->_skb_refdst;
skb_dst_set_noref(skb, &ovs_dst);
IPCB(skb)->frag_max_size = mru;
ip_do_fragment(net, skb->sk, skb, ovs_vport_output);
refdst_drop(orig_dst);
} else if (key->eth.type == htons(ETH_P_IPV6)) {
const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
unsigned long orig_dst;
struct rt6_info ovs_rt;
if (!v6ops) {
goto err;
}
prepare_frag(vport, skb, orig_network_offset,
ovs_key_mac_proto(key));
memset(&ovs_rt, 0, sizeof(ovs_rt));
dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
DST_OBSOLETE_NONE, DST_NOCOUNT);
ovs_rt.dst.dev = vport->dev;
orig_dst = skb->_skb_refdst;
skb_dst_set_noref(skb, &ovs_rt.dst);
IP6CB(skb)->frag_max_size = mru;
v6ops->fragment(net, skb->sk, skb, ovs_vport_output);
refdst_drop(orig_dst);
} else {
WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
ovs_vport_name(vport), ntohs(key->eth.type), mru,
vport->dev->mtu);
goto err;
}
return;
err:
kfree_skb(skb);
}
static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
struct sw_flow_key *key)
{
struct vport *vport = ovs_vport_rcu(dp, out_port);
if (likely(vport)) {
u16 mru = OVS_CB(skb)->mru;
u32 cutlen = OVS_CB(skb)->cutlen;
if (unlikely(cutlen > 0)) {
if (skb->len - cutlen > ovs_mac_header_len(key))
pskb_trim(skb, skb->len - cutlen);
else
pskb_trim(skb, ovs_mac_header_len(key));
}
if (likely(!mru ||
(skb->len <= mru + vport->dev->hard_header_len))) {
ovs_vport_send(vport, skb, ovs_key_mac_proto(key));
} else if (mru <= vport->dev->mtu) {
struct net *net = read_pnet(&dp->net);
ovs_fragment(net, vport, skb, mru, key);
} else {
kfree_skb(skb);
}
} else {
kfree_skb(skb);
}
}
static int output_userspace(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key, const struct nlattr *attr,
const struct nlattr *actions, int actions_len,
uint32_t cutlen)
{
struct dp_upcall_info upcall;
const struct nlattr *a;
int rem;
memset(&upcall, 0, sizeof(upcall));
upcall.cmd = OVS_PACKET_CMD_ACTION;
upcall.mru = OVS_CB(skb)->mru;
for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
a = nla_next(a, &rem)) {
switch (nla_type(a)) {
case OVS_USERSPACE_ATTR_USERDATA:
upcall.userdata = a;
break;
case OVS_USERSPACE_ATTR_PID:
upcall.portid = nla_get_u32(a);
break;
case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
/* Get out tunnel info. */
struct vport *vport;
vport = ovs_vport_rcu(dp, nla_get_u32(a));
if (vport) {
int err;
err = dev_fill_metadata_dst(vport->dev, skb);
if (!err)
upcall.egress_tun_info = skb_tunnel_info(skb);
}
break;
}
case OVS_USERSPACE_ATTR_ACTIONS: {
/* Include actions. */
upcall.actions = actions;
upcall.actions_len = actions_len;
break;
}
} /* End of switch. */
}
return ovs_dp_upcall(dp, skb, key, &upcall, cutlen);
}
static int sample(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key, const struct nlattr *attr,
const struct nlattr *actions, int actions_len)
{
const struct nlattr *acts_list = NULL;
const struct nlattr *a;
int rem;
u32 cutlen = 0;
for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
a = nla_next(a, &rem)) {
u32 probability;
switch (nla_type(a)) {
case OVS_SAMPLE_ATTR_PROBABILITY:
probability = nla_get_u32(a);
if (!probability || prandom_u32() > probability)
return 0;
break;
case OVS_SAMPLE_ATTR_ACTIONS:
acts_list = a;
break;
}
}
rem = nla_len(acts_list);
a = nla_data(acts_list);
/* Actions list is empty, do nothing */
if (unlikely(!rem))
return 0;
/* The only known usage of sample action is having a single user-space
* action, or having a truncate action followed by a single user-space
* action. Treat this usage as a special case.
* The output_userspace() should clone the skb to be sent to the
* user space. This skb will be consumed by its caller.
*/
if (unlikely(nla_type(a) == OVS_ACTION_ATTR_TRUNC)) {
struct ovs_action_trunc *trunc = nla_data(a);
if (skb->len > trunc->max_len)
cutlen = skb->len - trunc->max_len;
a = nla_next(a, &rem);
}
if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
nla_is_last(a, rem)))
return output_userspace(dp, skb, key, a, actions,
actions_len, cutlen);
skb = skb_clone(skb, GFP_ATOMIC);
if (!skb)
/* Skip the sample action when out of memory. */
return 0;
if (!add_deferred_actions(skb, key, a)) {
if (net_ratelimit())
pr_warn("%s: deferred actions limit reached, dropping sample action\n",
ovs_dp_name(dp));
kfree_skb(skb);
}
return 0;
}
static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
const struct nlattr *attr)
{
struct ovs_action_hash *hash_act = nla_data(attr);
u32 hash = 0;
/* OVS_HASH_ALG_L4 is the only possible hash algorithm. */
hash = skb_get_hash(skb);
hash = jhash_1word(hash, hash_act->hash_basis);
if (!hash)
hash = 0x1;
key->ovs_flow_hash = hash;
}
static int execute_set_action(struct sk_buff *skb,
struct sw_flow_key *flow_key,
const struct nlattr *a)
{
/* Only tunnel set execution is supported without a mask. */
if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) {
struct ovs_tunnel_info *tun = nla_data(a);
skb_dst_drop(skb);
dst_hold((struct dst_entry *)tun->tun_dst);
skb_dst_set(skb, (struct dst_entry *)tun->tun_dst);
return 0;
}
return -EINVAL;
}
/* Mask is at the midpoint of the data. */
#define get_mask(a, type) ((const type)nla_data(a) + 1)
static int execute_masked_set_action(struct sk_buff *skb,
struct sw_flow_key *flow_key,
const struct nlattr *a)
{
int err = 0;
switch (nla_type(a)) {
case OVS_KEY_ATTR_PRIORITY:
OVS_SET_MASKED(skb->priority, nla_get_u32(a),
*get_mask(a, u32 *));
flow_key->phy.priority = skb->priority;
break;
case OVS_KEY_ATTR_SKB_MARK:
OVS_SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *));
flow_key->phy.skb_mark = skb->mark;
break;
case OVS_KEY_ATTR_TUNNEL_INFO:
/* Masked data not supported for tunnel. */
err = -EINVAL;
break;
case OVS_KEY_ATTR_ETHERNET:
err = set_eth_addr(skb, flow_key, nla_data(a),
get_mask(a, struct ovs_key_ethernet *));
break;
case OVS_KEY_ATTR_IPV4:
err = set_ipv4(skb, flow_key, nla_data(a),
get_mask(a, struct ovs_key_ipv4 *));
break;
case OVS_KEY_ATTR_IPV6:
err = set_ipv6(skb, flow_key, nla_data(a),
get_mask(a, struct ovs_key_ipv6 *));
break;
case OVS_KEY_ATTR_TCP:
err = set_tcp(skb, flow_key, nla_data(a),
get_mask(a, struct ovs_key_tcp *));
break;
case OVS_KEY_ATTR_UDP:
err = set_udp(skb, flow_key, nla_data(a),
get_mask(a, struct ovs_key_udp *));
break;
case OVS_KEY_ATTR_SCTP:
err = set_sctp(skb, flow_key, nla_data(a),
get_mask(a, struct ovs_key_sctp *));
break;
case OVS_KEY_ATTR_MPLS:
err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
__be32 *));
break;
case OVS_KEY_ATTR_CT_STATE:
case OVS_KEY_ATTR_CT_ZONE:
case OVS_KEY_ATTR_CT_MARK:
case OVS_KEY_ATTR_CT_LABELS:
case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4:
case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6:
err = -EINVAL;
break;
}
return err;
}
static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key,
const struct nlattr *a, int rem)
{
struct deferred_action *da;
int level;
if (!is_flow_key_valid(key)) {
int err;
err = ovs_flow_key_update(skb, key);
if (err)
return err;
}
BUG_ON(!is_flow_key_valid(key));
if (!nla_is_last(a, rem)) {
/* Recirc action is the not the last action
* of the action list, need to clone the skb.
*/
skb = skb_clone(skb, GFP_ATOMIC);
/* Skip the recirc action when out of memory, but
* continue on with the rest of the action list.
*/
if (!skb)
return 0;
}
level = this_cpu_read(exec_actions_level);
if (level <= OVS_DEFERRED_ACTION_THRESHOLD) {
struct recirc_keys *rks = this_cpu_ptr(recirc_keys);
struct sw_flow_key *recirc_key = &rks->key[level - 1];
*recirc_key = *key;
recirc_key->recirc_id = nla_get_u32(a);
ovs_dp_process_packet(skb, recirc_key);
return 0;
}
da = add_deferred_actions(skb, key, NULL);
if (da) {
da->pkt_key.recirc_id = nla_get_u32(a);
} else {
kfree_skb(skb);
if (net_ratelimit())
pr_warn("%s: deferred action limit reached, drop recirc action\n",
ovs_dp_name(dp));
}
return 0;
}
/* Execute a list of actions against 'skb'. */
static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key,
const struct nlattr *attr, int len)
{
const struct nlattr *a;
int rem;
for (a = attr, rem = len; rem > 0;
a = nla_next(a, &rem)) {
int err = 0;
switch (nla_type(a)) {
case OVS_ACTION_ATTR_OUTPUT: {
int port = nla_get_u32(a);
struct sk_buff *clone;
/* Every output action needs a separate clone
* of 'skb', In case the output action is the
* last action, cloning can be avoided.
*/
if (nla_is_last(a, rem)) {
do_output(dp, skb, port, key);
/* 'skb' has been used for output.
*/
return 0;
}
clone = skb_clone(skb, GFP_ATOMIC);
if (clone)
do_output(dp, clone, port, key);
OVS_CB(skb)->cutlen = 0;
break;
}
case OVS_ACTION_ATTR_TRUNC: {
struct ovs_action_trunc *trunc = nla_data(a);
if (skb->len > trunc->max_len)
OVS_CB(skb)->cutlen = skb->len - trunc->max_len;
break;
}
case OVS_ACTION_ATTR_USERSPACE:
output_userspace(dp, skb, key, a, attr,
len, OVS_CB(skb)->cutlen);
OVS_CB(skb)->cutlen = 0;
break;
case OVS_ACTION_ATTR_HASH:
execute_hash(skb, key, a);
break;
case OVS_ACTION_ATTR_PUSH_MPLS:
err = push_mpls(skb, key, nla_data(a));
break;
case OVS_ACTION_ATTR_POP_MPLS:
err = pop_mpls(skb, key, nla_get_be16(a));
break;
case OVS_ACTION_ATTR_PUSH_VLAN:
err = push_vlan(skb, key, nla_data(a));
break;
case OVS_ACTION_ATTR_POP_VLAN:
err = pop_vlan(skb, key);
break;
case OVS_ACTION_ATTR_RECIRC:
err = execute_recirc(dp, skb, key, a, rem);
if (nla_is_last(a, rem)) {
/* If this is the last action, the skb has
* been consumed or freed.
* Return immediately.
*/
return err;
}
break;
case OVS_ACTION_ATTR_SET:
err = execute_set_action(skb, key, nla_data(a));
break;
case OVS_ACTION_ATTR_SET_MASKED:
case OVS_ACTION_ATTR_SET_TO_MASKED:
err = execute_masked_set_action(skb, key, nla_data(a));
break;
case OVS_ACTION_ATTR_SAMPLE:
err = sample(dp, skb, key, a, attr, len);
break;
case OVS_ACTION_ATTR_CT:
if (!is_flow_key_valid(key)) {
err = ovs_flow_key_update(skb, key);
if (err)
return err;
}
err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
nla_data(a));
/* Hide stolen IP fragments from user space. */
if (err)
return err == -EINPROGRESS ? 0 : err;
break;
case OVS_ACTION_ATTR_PUSH_ETH:
err = push_eth(skb, key, nla_data(a));
break;
case OVS_ACTION_ATTR_POP_ETH:
err = pop_eth(skb, key);
break;
}
if (unlikely(err)) {
kfree_skb(skb);
return err;
}
}
consume_skb(skb);
return 0;
}
static void process_deferred_actions(struct datapath *dp)
{
struct action_fifo *fifo = this_cpu_ptr(action_fifos);
/* Do not touch the FIFO in case there is no deferred actions. */
if (action_fifo_is_empty(fifo))
return;
/* Finishing executing all deferred actions. */
do {
struct deferred_action *da = action_fifo_get(fifo);
struct sk_buff *skb = da->skb;
struct sw_flow_key *key = &da->pkt_key;
const struct nlattr *actions = da->actions;
if (actions)
do_execute_actions(dp, skb, key, actions,
nla_len(actions));
else
ovs_dp_process_packet(skb, key);
} while (!action_fifo_is_empty(fifo));
/* Reset FIFO for the next packet. */
action_fifo_init(fifo);
}
/* Execute a list of actions against 'skb'. */
int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
const struct sw_flow_actions *acts,
struct sw_flow_key *key)
{
int err, level;
level = __this_cpu_inc_return(exec_actions_level);
if (unlikely(level > OVS_RECURSION_LIMIT)) {
net_crit_ratelimited("ovs: recursion limit reached on datapath %s, probable configuration error\n",
ovs_dp_name(dp));
kfree_skb(skb);
err = -ENETDOWN;
goto out;
}
err = do_execute_actions(dp, skb, key,
acts->actions, acts->actions_len);
if (level == 1)
process_deferred_actions(dp);
out:
__this_cpu_dec(exec_actions_level);
return err;
}
int action_fifos_init(void)
{
action_fifos = alloc_percpu(struct action_fifo);
if (!action_fifos)
return -ENOMEM;
recirc_keys = alloc_percpu(struct recirc_keys);
if (!recirc_keys) {
free_percpu(action_fifos);
return -ENOMEM;
}
return 0;
}
void action_fifos_exit(void)
{
free_percpu(action_fifos);
free_percpu(recirc_keys);
}
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