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openvswitch/utilities/ovs-controller.c
Ben Pfaff 7778bd15da secchan: Better tolerate failing controller admission control in fail-open.
When the switch is configured to connect to a controller that accepts
connections, waits a few seconds, and then disconnects without setting up
flows, currently this causes "fail-open" to flush the flow table and
stop setting up new flows during the connection duration.  This is OK if
it happens once, but it can easily happen every 8 seconds with typical
backoff settings, and that isn't so great.

This commit changes fail-open to only flush the flow table once the switch
appears to have been admitted by the controller, which prevents these
frequent network interruptions.

Thanks to Jesse Gross for especially valuable feedback.

QA notes: Behavior in fail-open and especially behavior with a controller
that rejects the switch after it connects needs to be re-tested.  The
ovs-controller --mute switch added by this commit is one simple way to
create such a controller.

CC: Peter Balland <peter@nicira.com>

Bug #1695.  Bug #2055.
2009-09-16 15:12:27 -07:00

336 lines
9.3 KiB
C

/*
* Copyright (c) 2008, 2009 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 <errno.h>
#include <getopt.h>
#include <limits.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include "command-line.h"
#include "compiler.h"
#include "daemon.h"
#include "fault.h"
#include "learning-switch.h"
#include "ofpbuf.h"
#include "openflow/openflow.h"
#include "poll-loop.h"
#include "rconn.h"
#include "timeval.h"
#include "unixctl.h"
#include "util.h"
#include "vconn-ssl.h"
#include "vconn.h"
#include "vlog.h"
#define THIS_MODULE VLM_controller
#define MAX_SWITCHES 16
#define MAX_LISTENERS 16
struct switch_ {
struct lswitch *lswitch;
struct rconn *rconn;
};
/* Learn the ports on which MAC addresses appear? */
static bool learn_macs = true;
/* Set up flows? (If not, every packet is processed at the controller.) */
static bool setup_flows = true;
/* --max-idle: Maximum idle time, in seconds, before flows expire. */
static int max_idle = 60;
/* --mute: If true, accept connections from switches but do not reply to any
* of their messages (for debugging fail-open mode). */
static bool mute = false;
static int do_switching(struct switch_ *);
static void new_switch(struct switch_ *, struct vconn *, const char *name);
static void parse_options(int argc, char *argv[]);
static void usage(void) NO_RETURN;
int
main(int argc, char *argv[])
{
struct unixctl_server *unixctl;
struct switch_ switches[MAX_SWITCHES];
struct pvconn *listeners[MAX_LISTENERS];
int n_switches, n_listeners;
int retval;
int i;
set_program_name(argv[0]);
register_fault_handlers();
time_init();
vlog_init();
parse_options(argc, argv);
signal(SIGPIPE, SIG_IGN);
if (argc - optind < 1) {
ovs_fatal(0, "at least one vconn argument required; "
"use --help for usage");
}
n_switches = n_listeners = 0;
for (i = optind; i < argc; i++) {
const char *name = argv[i];
struct vconn *vconn;
int retval;
retval = vconn_open(name, OFP_VERSION, &vconn);
if (!retval) {
if (n_switches >= MAX_SWITCHES) {
ovs_fatal(0, "max %d switch connections", n_switches);
}
new_switch(&switches[n_switches++], vconn, name);
continue;
} else if (retval == EAFNOSUPPORT) {
struct pvconn *pvconn;
retval = pvconn_open(name, &pvconn);
if (!retval) {
if (n_listeners >= MAX_LISTENERS) {
ovs_fatal(0, "max %d passive connections", n_listeners);
}
listeners[n_listeners++] = pvconn;
}
}
if (retval) {
VLOG_ERR("%s: connect: %s", name, strerror(retval));
}
}
if (n_switches == 0 && n_listeners == 0) {
ovs_fatal(0, "no active or passive switch connections");
}
die_if_already_running();
daemonize();
retval = unixctl_server_create(NULL, &unixctl);
if (retval) {
ovs_fatal(retval, "Could not listen for unixctl connections");
}
while (n_switches > 0 || n_listeners > 0) {
int iteration;
int i;
/* Accept connections on listening vconns. */
for (i = 0; i < n_listeners && n_switches < MAX_SWITCHES; ) {
struct vconn *new_vconn;
int retval;
retval = pvconn_accept(listeners[i], OFP_VERSION, &new_vconn);
if (!retval || retval == EAGAIN) {
if (!retval) {
new_switch(&switches[n_switches++], new_vconn, "tcp");
}
i++;
} else {
pvconn_close(listeners[i]);
listeners[i] = listeners[--n_listeners];
}
}
/* Do some switching work. Limit the number of iterations so that
* callbacks registered with the poll loop don't starve. */
for (iteration = 0; iteration < 50; iteration++) {
bool progress = false;
for (i = 0; i < n_switches; ) {
struct switch_ *this = &switches[i];
int retval = do_switching(this);
if (!retval || retval == EAGAIN) {
if (!retval) {
progress = true;
}
i++;
} else {
rconn_destroy(this->rconn);
lswitch_destroy(this->lswitch);
switches[i] = switches[--n_switches];
}
}
if (!progress) {
break;
}
}
for (i = 0; i < n_switches; i++) {
struct switch_ *this = &switches[i];
lswitch_run(this->lswitch, this->rconn);
}
unixctl_server_run(unixctl);
/* Wait for something to happen. */
if (n_switches < MAX_SWITCHES) {
for (i = 0; i < n_listeners; i++) {
pvconn_wait(listeners[i]);
}
}
for (i = 0; i < n_switches; i++) {
struct switch_ *sw = &switches[i];
rconn_run_wait(sw->rconn);
rconn_recv_wait(sw->rconn);
lswitch_wait(sw->lswitch);
}
unixctl_server_wait(unixctl);
poll_block();
}
return 0;
}
static void
new_switch(struct switch_ *sw, struct vconn *vconn, const char *name)
{
sw->rconn = rconn_new_from_vconn(name, vconn);
sw->lswitch = lswitch_create(sw->rconn, learn_macs,
setup_flows ? max_idle : -1);
}
static int
do_switching(struct switch_ *sw)
{
unsigned int packets_sent;
struct ofpbuf *msg;
packets_sent = rconn_packets_sent(sw->rconn);
msg = rconn_recv(sw->rconn);
if (msg) {
if (!mute) {
lswitch_process_packet(sw->lswitch, sw->rconn, msg);
}
ofpbuf_delete(msg);
}
rconn_run(sw->rconn);
return (!rconn_is_alive(sw->rconn) ? EOF
: rconn_packets_sent(sw->rconn) != packets_sent ? 0
: EAGAIN);
}
static void
parse_options(int argc, char *argv[])
{
enum {
OPT_MAX_IDLE = UCHAR_MAX + 1,
OPT_PEER_CA_CERT,
OPT_MUTE,
VLOG_OPTION_ENUMS
};
static struct option long_options[] = {
{"hub", no_argument, 0, 'H'},
{"noflow", no_argument, 0, 'n'},
{"max-idle", required_argument, 0, OPT_MAX_IDLE},
{"mute", no_argument, 0, OPT_MUTE},
{"help", no_argument, 0, 'h'},
{"version", no_argument, 0, 'V'},
DAEMON_LONG_OPTIONS,
VLOG_LONG_OPTIONS,
#ifdef HAVE_OPENSSL
VCONN_SSL_LONG_OPTIONS
{"peer-ca-cert", required_argument, 0, OPT_PEER_CA_CERT},
#endif
{0, 0, 0, 0},
};
char *short_options = long_options_to_short_options(long_options);
for (;;) {
int indexptr;
int c;
c = getopt_long(argc, argv, short_options, long_options, &indexptr);
if (c == -1) {
break;
}
switch (c) {
case 'H':
learn_macs = false;
break;
case 'n':
setup_flows = false;
break;
case OPT_MUTE:
mute = true;
break;
case OPT_MAX_IDLE:
if (!strcmp(optarg, "permanent")) {
max_idle = OFP_FLOW_PERMANENT;
} else {
max_idle = atoi(optarg);
if (max_idle < 1 || max_idle > 65535) {
ovs_fatal(0, "--max-idle argument must be between 1 and "
"65535 or the word 'permanent'");
}
}
break;
case 'h':
usage();
case 'V':
OVS_PRINT_VERSION(OFP_VERSION, OFP_VERSION);
exit(EXIT_SUCCESS);
VLOG_OPTION_HANDLERS
DAEMON_OPTION_HANDLERS
#ifdef HAVE_OPENSSL
VCONN_SSL_OPTION_HANDLERS
case OPT_PEER_CA_CERT:
vconn_ssl_set_peer_ca_cert_file(optarg);
break;
#endif
case '?':
exit(EXIT_FAILURE);
default:
abort();
}
}
free(short_options);
}
static void
usage(void)
{
printf("%s: OpenFlow controller\n"
"usage: %s [OPTIONS] METHOD\n"
"where METHOD is any OpenFlow connection method.\n",
program_name, program_name);
vconn_usage(true, true, false);
daemon_usage();
vlog_usage();
printf("\nOther options:\n"
" -H, --hub act as hub instead of learning switch\n"
" -n, --noflow pass traffic, but don't add flows\n"
" --max-idle=SECS max idle time for new flows\n"
" -h, --help display this help message\n"
" -V, --version display version information\n");
exit(EXIT_SUCCESS);
}