/usr/src/openvswitch-1.4.0/ofproto/in-band.c is in openvswitch-datapath-dkms 1.4.0-1ubuntu1.
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* Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include "in-band.h"
#include <arpa/inet.h>
#include <errno.h>
#include <inttypes.h>
#include <sys/socket.h>
#include <net/if.h>
#include <string.h>
#include <stdlib.h>
#include "classifier.h"
#include "dhcp.h"
#include "flow.h"
#include "netdev.h"
#include "netlink.h"
#include "odp-util.h"
#include "ofproto.h"
#include "ofpbuf.h"
#include "ofproto-provider.h"
#include "openflow/openflow.h"
#include "packets.h"
#include "poll-loop.h"
#include "timeval.h"
#include "vlog.h"
VLOG_DEFINE_THIS_MODULE(in_band);
/* Priorities used in classifier for in-band rules. These values are higher
* than any that may be set with OpenFlow, and "18" kind of looks like "IB".
* The ordering of priorities is not important because all of the rules set up
* by in-band control have the same action. The only reason to use more than
* one priority is to make the kind of flow easier to see during debugging. */
enum {
/* One set per bridge. */
IBR_FROM_LOCAL_DHCP = 180000, /* (a) From local port, DHCP. */
IBR_TO_LOCAL_ARP, /* (b) To local port, ARP. */
IBR_FROM_LOCAL_ARP, /* (c) From local port, ARP. */
/* One set per unique next-hop MAC. */
IBR_TO_NEXT_HOP_ARP, /* (d) To remote MAC, ARP. */
IBR_FROM_NEXT_HOP_ARP, /* (e) From remote MAC, ARP. */
/* One set per unique remote IP address. */
IBR_TO_REMOTE_ARP, /* (f) To remote IP, ARP. */
IBR_FROM_REMOTE_ARP, /* (g) From remote IP, ARP. */
/* One set per unique remote (IP,port) pair. */
IBR_TO_REMOTE_TCP, /* (h) To remote IP, TCP port. */
IBR_FROM_REMOTE_TCP /* (i) From remote IP, TCP port. */
};
/* Track one remote IP and next hop information. */
struct in_band_remote {
struct sockaddr_in remote_addr; /* IP address, in network byte order. */
uint8_t remote_mac[ETH_ADDR_LEN]; /* Next-hop MAC, all-zeros if unknown. */
uint8_t last_remote_mac[ETH_ADDR_LEN]; /* Previous nonzero next-hop MAC. */
struct netdev *remote_netdev; /* Device to send to next-hop MAC. */
};
/* What to do to an in_band_rule. */
enum in_band_op {
ADD, /* Add the rule to ofproto's flow table. */
DELETE /* Delete the rule from ofproto's flow table. */
};
/* A rule to add to or delete from ofproto's flow table. */
struct in_band_rule {
struct cls_rule cls_rule;
enum in_band_op op;
};
struct in_band {
struct ofproto *ofproto;
int queue_id;
/* Remote information. */
time_t next_remote_refresh; /* Refresh timer. */
struct in_band_remote *remotes;
size_t n_remotes;
/* Local information. */
time_t next_local_refresh; /* Refresh timer. */
uint8_t local_mac[ETH_ADDR_LEN]; /* Current MAC. */
struct netdev *local_netdev; /* Local port's network device. */
/* Flow tracking. */
struct hmap rules; /* Contains "struct in_band_rule"s. */
};
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(60, 60);
static int
refresh_remote(struct in_band *ib, struct in_band_remote *r)
{
struct in_addr next_hop_inaddr;
char *next_hop_dev;
int retval;
/* Find the next-hop IP address. */
memset(r->remote_mac, 0, sizeof r->remote_mac);
retval = netdev_get_next_hop(ib->local_netdev, &r->remote_addr.sin_addr,
&next_hop_inaddr, &next_hop_dev);
if (retval) {
VLOG_WARN("cannot find route for controller ("IP_FMT"): %s",
IP_ARGS(&r->remote_addr.sin_addr), strerror(retval));
return 1;
}
if (!next_hop_inaddr.s_addr) {
next_hop_inaddr = r->remote_addr.sin_addr;
}
/* Open the next-hop network device. */
if (!r->remote_netdev
|| strcmp(netdev_get_name(r->remote_netdev), next_hop_dev))
{
netdev_close(r->remote_netdev);
retval = netdev_open(next_hop_dev, "system", &r->remote_netdev);
if (retval) {
VLOG_WARN_RL(&rl, "cannot open netdev %s (next hop "
"to controller "IP_FMT"): %s",
next_hop_dev, IP_ARGS(&r->remote_addr.sin_addr),
strerror(retval));
free(next_hop_dev);
return 1;
}
}
free(next_hop_dev);
/* Look up the MAC address of the next-hop IP address. */
retval = netdev_arp_lookup(r->remote_netdev, next_hop_inaddr.s_addr,
r->remote_mac);
if (retval) {
VLOG_DBG_RL(&rl, "cannot look up remote MAC address ("IP_FMT"): %s",
IP_ARGS(&next_hop_inaddr.s_addr), strerror(retval));
}
/* If we don't have a MAC address, then refresh quickly, since we probably
* will get a MAC address soon (via ARP). Otherwise, we can afford to wait
* a little while. */
return eth_addr_is_zero(r->remote_mac) ? 1 : 10;
}
static bool
refresh_remotes(struct in_band *ib)
{
struct in_band_remote *r;
bool any_changes;
if (time_now() < ib->next_remote_refresh) {
return false;
}
any_changes = false;
ib->next_remote_refresh = TIME_MAX;
for (r = ib->remotes; r < &ib->remotes[ib->n_remotes]; r++) {
uint8_t old_remote_mac[ETH_ADDR_LEN];
time_t next_refresh;
/* Save old MAC. */
memcpy(old_remote_mac, r->remote_mac, ETH_ADDR_LEN);
/* Refresh remote information. */
next_refresh = refresh_remote(ib, r) + time_now();
ib->next_remote_refresh = MIN(ib->next_remote_refresh, next_refresh);
/* If the MAC changed, log the changes. */
if (!eth_addr_equals(r->remote_mac, old_remote_mac)) {
any_changes = true;
if (!eth_addr_is_zero(r->remote_mac)
&& !eth_addr_equals(r->last_remote_mac, r->remote_mac)) {
VLOG_DBG("remote MAC address changed from "ETH_ADDR_FMT
" to "ETH_ADDR_FMT,
ETH_ADDR_ARGS(r->last_remote_mac),
ETH_ADDR_ARGS(r->remote_mac));
memcpy(r->last_remote_mac, r->remote_mac, ETH_ADDR_LEN);
}
}
}
return any_changes;
}
/* Refreshes the MAC address of the local port into ib->local_mac, if it is due
* for a refresh. Returns true if anything changed, otherwise false. */
static bool
refresh_local(struct in_band *ib)
{
uint8_t ea[ETH_ADDR_LEN];
time_t now;
now = time_now();
if (now < ib->next_local_refresh) {
return false;
}
ib->next_local_refresh = now + 1;
if (netdev_get_etheraddr(ib->local_netdev, ea)
|| eth_addr_equals(ea, ib->local_mac)) {
return false;
}
memcpy(ib->local_mac, ea, ETH_ADDR_LEN);
return true;
}
/* Returns true if 'packet' should be sent to the local port regardless
* of the flow table. */
bool
in_band_msg_in_hook(struct in_band *in_band, const struct flow *flow,
const struct ofpbuf *packet)
{
/* Regardless of how the flow table is configured, we want to be
* able to see replies to our DHCP requests. */
if (flow->dl_type == htons(ETH_TYPE_IP)
&& flow->nw_proto == IPPROTO_UDP
&& flow->tp_src == htons(DHCP_SERVER_PORT)
&& flow->tp_dst == htons(DHCP_CLIENT_PORT)
&& packet->l7) {
struct dhcp_header *dhcp;
dhcp = ofpbuf_at(packet, (char *)packet->l7 - (char *)packet->data,
sizeof *dhcp);
if (!dhcp) {
return false;
}
refresh_local(in_band);
if (!eth_addr_is_zero(in_band->local_mac)
&& eth_addr_equals(dhcp->chaddr, in_band->local_mac)) {
return true;
}
}
return false;
}
/* Returns true if the rule that would match 'flow' with 'actions' is
* allowed to be set up in the datapath. */
bool
in_band_rule_check(const struct flow *flow,
const struct nlattr *actions, size_t actions_len)
{
/* Don't allow flows that would prevent DHCP replies from being seen
* by the local port. */
if (flow->dl_type == htons(ETH_TYPE_IP)
&& flow->nw_proto == IPPROTO_UDP
&& flow->tp_src == htons(DHCP_SERVER_PORT)
&& flow->tp_dst == htons(DHCP_CLIENT_PORT)) {
const struct nlattr *a;
unsigned int left;
NL_ATTR_FOR_EACH_UNSAFE (a, left, actions, actions_len) {
if (nl_attr_type(a) == OVS_ACTION_ATTR_OUTPUT
&& nl_attr_get_u32(a) == OVSP_LOCAL) {
return true;
}
}
return false;
}
return true;
}
static void
add_rule(struct in_band *ib, const struct cls_rule *cls_rule)
{
uint32_t hash = cls_rule_hash(cls_rule, 0);
struct in_band_rule *rule;
HMAP_FOR_EACH_WITH_HASH (rule, cls_rule.hmap_node, hash, &ib->rules) {
if (cls_rule_equal(&rule->cls_rule, cls_rule)) {
rule->op = ADD;
return;
}
}
rule = xmalloc(sizeof *rule);
rule->cls_rule = *cls_rule;
rule->op = ADD;
hmap_insert(&ib->rules, &rule->cls_rule.hmap_node, hash);
}
static void
update_rules(struct in_band *ib)
{
struct in_band_rule *ib_rule;
struct in_band_remote *r;
struct cls_rule rule;
/* Mark all the existing rules for deletion. (Afterward we will re-add any
* rules that are still valid.) */
HMAP_FOR_EACH (ib_rule, cls_rule.hmap_node, &ib->rules) {
ib_rule->op = DELETE;
}
if (ib->n_remotes && !eth_addr_is_zero(ib->local_mac)) {
/* (a) Allow DHCP requests sent from the local port. */
cls_rule_init_catchall(&rule, IBR_FROM_LOCAL_DHCP);
cls_rule_set_in_port(&rule, OFPP_LOCAL);
cls_rule_set_dl_type(&rule, htons(ETH_TYPE_IP));
cls_rule_set_dl_src(&rule, ib->local_mac);
cls_rule_set_nw_proto(&rule, IPPROTO_UDP);
cls_rule_set_tp_src(&rule, htons(DHCP_CLIENT_PORT));
cls_rule_set_tp_dst(&rule, htons(DHCP_SERVER_PORT));
add_rule(ib, &rule);
/* (b) Allow ARP replies to the local port's MAC address. */
cls_rule_init_catchall(&rule, IBR_TO_LOCAL_ARP);
cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
cls_rule_set_dl_dst(&rule, ib->local_mac);
cls_rule_set_nw_proto(&rule, ARP_OP_REPLY);
add_rule(ib, &rule);
/* (c) Allow ARP requests from the local port's MAC address. */
cls_rule_init_catchall(&rule, IBR_FROM_LOCAL_ARP);
cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
cls_rule_set_dl_src(&rule, ib->local_mac);
cls_rule_set_nw_proto(&rule, ARP_OP_REQUEST);
add_rule(ib, &rule);
}
for (r = ib->remotes; r < &ib->remotes[ib->n_remotes]; r++) {
const uint8_t *remote_mac = r->remote_mac;
if (eth_addr_is_zero(remote_mac)) {
continue;
}
/* (d) Allow ARP replies to the next hop's MAC address. */
cls_rule_init_catchall(&rule, IBR_TO_NEXT_HOP_ARP);
cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
cls_rule_set_dl_dst(&rule, remote_mac);
cls_rule_set_nw_proto(&rule, ARP_OP_REPLY);
add_rule(ib, &rule);
/* (e) Allow ARP requests from the next hop's MAC address. */
cls_rule_init_catchall(&rule, IBR_FROM_NEXT_HOP_ARP);
cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
cls_rule_set_dl_src(&rule, remote_mac);
cls_rule_set_nw_proto(&rule, ARP_OP_REQUEST);
add_rule(ib, &rule);
}
for (r = ib->remotes; r < &ib->remotes[ib->n_remotes]; r++) {
const struct sockaddr_in *a = &r->remote_addr;
/* (f) Allow ARP replies containing the remote's IP address as a
* target. */
cls_rule_init_catchall(&rule, IBR_TO_REMOTE_ARP);
cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
cls_rule_set_nw_proto(&rule, ARP_OP_REPLY);
cls_rule_set_nw_dst(&rule, a->sin_addr.s_addr);
add_rule(ib, &rule);
/* (g) Allow ARP requests containing the remote's IP address as a
* source. */
cls_rule_init_catchall(&rule, IBR_FROM_REMOTE_ARP);
cls_rule_set_dl_type(&rule, htons(ETH_TYPE_ARP));
cls_rule_set_nw_proto(&rule, ARP_OP_REQUEST);
cls_rule_set_nw_src(&rule, a->sin_addr.s_addr);
add_rule(ib, &rule);
/* (h) Allow TCP traffic to the remote's IP and port. */
cls_rule_init_catchall(&rule, IBR_TO_REMOTE_TCP);
cls_rule_set_dl_type(&rule, htons(ETH_TYPE_IP));
cls_rule_set_nw_proto(&rule, IPPROTO_TCP);
cls_rule_set_nw_dst(&rule, a->sin_addr.s_addr);
cls_rule_set_tp_dst(&rule, a->sin_port);
add_rule(ib, &rule);
/* (i) Allow TCP traffic from the remote's IP and port. */
cls_rule_init_catchall(&rule, IBR_FROM_REMOTE_TCP);
cls_rule_set_dl_type(&rule, htons(ETH_TYPE_IP));
cls_rule_set_nw_proto(&rule, IPPROTO_TCP);
cls_rule_set_nw_src(&rule, a->sin_addr.s_addr);
cls_rule_set_tp_src(&rule, a->sin_port);
add_rule(ib, &rule);
}
}
/* Updates the OpenFlow flow table for the current state of in-band control.
* Returns true ordinarily. Returns false if no remotes are configured on 'ib'
* and 'ib' doesn't have any rules left to remove from the OpenFlow flow
* table. Thus, a false return value means that the caller can destroy 'ib'
* without leaving extra flows hanging around in the flow table. */
bool
in_band_run(struct in_band *ib)
{
struct {
struct nx_action_set_queue nxsq;
union ofp_action oa;
} actions;
const void *a;
size_t na;
struct in_band_rule *rule, *next;
memset(&actions, 0, sizeof actions);
actions.oa.output.type = htons(OFPAT_OUTPUT);
actions.oa.output.len = htons(sizeof actions.oa);
actions.oa.output.port = htons(OFPP_NORMAL);
actions.oa.output.max_len = htons(0);
if (ib->queue_id < 0) {
a = &actions.oa;
na = sizeof actions.oa / sizeof(union ofp_action);
} else {
actions.nxsq.type = htons(OFPAT_VENDOR);
actions.nxsq.len = htons(sizeof actions.nxsq);
actions.nxsq.vendor = htonl(NX_VENDOR_ID);
actions.nxsq.subtype = htons(NXAST_SET_QUEUE);
actions.nxsq.queue_id = htonl(ib->queue_id);
a = &actions;
na = sizeof actions / sizeof(union ofp_action);
}
refresh_local(ib);
refresh_remotes(ib);
update_rules(ib);
HMAP_FOR_EACH_SAFE (rule, next, cls_rule.hmap_node, &ib->rules) {
switch (rule->op) {
case ADD:
ofproto_add_flow(ib->ofproto, &rule->cls_rule, a, na);
break;
case DELETE:
if (ofproto_delete_flow(ib->ofproto, &rule->cls_rule)) {
/* ofproto doesn't have the rule anymore so there's no reason
* for us to track it any longer. */
hmap_remove(&ib->rules, &rule->cls_rule.hmap_node);
free(rule);
}
break;
}
}
return ib->n_remotes || !hmap_is_empty(&ib->rules);
}
void
in_band_wait(struct in_band *in_band)
{
long long int wakeup
= MIN(in_band->next_remote_refresh, in_band->next_local_refresh);
poll_timer_wait_until(wakeup * 1000);
}
int
in_band_create(struct ofproto *ofproto, const char *local_name,
struct in_band **in_bandp)
{
struct in_band *in_band;
struct netdev *local_netdev;
int error;
*in_bandp = NULL;
error = netdev_open(local_name, "system", &local_netdev);
if (error) {
VLOG_ERR("failed to initialize in-band control: cannot open "
"datapath local port %s (%s)", local_name, strerror(error));
return error;
}
in_band = xzalloc(sizeof *in_band);
in_band->ofproto = ofproto;
in_band->queue_id = -1;
in_band->next_remote_refresh = TIME_MIN;
in_band->next_local_refresh = TIME_MIN;
in_band->local_netdev = local_netdev;
hmap_init(&in_band->rules);
*in_bandp = in_band;
return 0;
}
void
in_band_destroy(struct in_band *ib)
{
if (ib) {
struct in_band_rule *rule, *next;
HMAP_FOR_EACH_SAFE (rule, next, cls_rule.hmap_node, &ib->rules) {
hmap_remove(&ib->rules, &rule->cls_rule.hmap_node);
free(rule);
}
hmap_destroy(&ib->rules);
in_band_set_remotes(ib, NULL, 0);
netdev_close(ib->local_netdev);
free(ib);
}
}
static bool
any_addresses_changed(struct in_band *ib,
const struct sockaddr_in *addresses, size_t n)
{
size_t i;
if (n != ib->n_remotes) {
return true;
}
for (i = 0; i < n; i++) {
const struct sockaddr_in *old = &ib->remotes[i].remote_addr;
const struct sockaddr_in *new = &addresses[i];
if (old->sin_addr.s_addr != new->sin_addr.s_addr ||
old->sin_port != new->sin_port) {
return true;
}
}
return false;
}
void
in_band_set_remotes(struct in_band *ib,
const struct sockaddr_in *addresses, size_t n)
{
size_t i;
if (!any_addresses_changed(ib, addresses, n)) {
return;
}
/* Clear old remotes. */
for (i = 0; i < ib->n_remotes; i++) {
netdev_close(ib->remotes[i].remote_netdev);
}
free(ib->remotes);
/* Set up new remotes. */
ib->remotes = n ? xzalloc(n * sizeof *ib->remotes) : NULL;
ib->n_remotes = n;
for (i = 0; i < n; i++) {
ib->remotes[i].remote_addr = addresses[i];
}
/* Force refresh in next call to in_band_run(). */
ib->next_remote_refresh = TIME_MIN;
}
/* Sets the OpenFlow queue used by flows set up by 'ib' to 'queue_id'. If
* 'queue_id' is negative, 'ib' will not set any queue (which is also the
* default). */
void
in_band_set_queue(struct in_band *ib, int queue_id)
{
ib->queue_id = queue_id;
}
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