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ovs/lib/dpif-linux.c

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/*
datapath: Report kernel's flow key when passing packets up to userspace. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. This commit takes one step in that direction by making the kernel report its idea of the flow that a packet belongs to whenever it passes a packet up to userspace. This means that userspace can intelligently figure out what to do: - If userspace's notion of the flow for the packet matches the kernel's, then nothing special is necessary. - If the kernel has a more specific notion for the flow than userspace, for example if the kernel decoded IPv6 headers but userspace stopped at the Ethernet type (because it does not understand IPv6), then again nothing special is necessary: userspace can still set up the flow in the usual way. - If userspace has a more specific notion for the flow than the kernel, for example if userspace decoded an IPv6 header but the kernel stopped at the Ethernet type, then userspace can forward the packet manually, without setting up a flow in the kernel. (This case is bad from a performance point of view, but at least it is correct.) This commit does not actually make userspace flexible enough to handle changes in the kernel flow key structure, although userspace does now have enough information to do that intelligently. This will have to wait for later commits. This commit is bigger than it would otherwise be because it is rolled together with changing "struct odp_msg" to a sequence of Netlink attributes. The alternative, to do each of those changes in a separate patch, seemed like overkill because it meant that either we would have to introduce and then kill off Netlink attributes for in_port and tun_id, if Netlink conversion went first, or shove yet another variable-length header into the stuff already after odp_msg, if adding the flow key to odp_msg went first. This commit will slow down performance of checksumming packets sent up to userspace. I'm not entirely pleased with how I did it. I considered a couple of alternatives, but none of them seemed that much better. Suggestions welcome. Not changing anything wasn't an option, unfortunately. At any rate some slowdown will become unavoidable when OVS actually starts using Netlink instead of just Netlink framing. (Actually, I thought of one option where we could avoid that: make userspace do the checksum instead, by passing csum_start and csum_offset as part of what goes to userspace. But that's not perfect either.) Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2011-01-24 14:59:57 -08:00
* 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 "dpif-linux.h"
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <net/if.h>
#include <linux/types.h>
#include <linux/ethtool.h>
#include <linux/pkt_sched.h>
#include <linux/rtnetlink.h>
#include <linux/sockios.h>
#include <stdlib.h>
#include <sys/ioctl.h>
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#include <sys/stat.h>
#include <unistd.h>
#include "dpif-provider.h"
#include "netdev.h"
#include "netdev-vport.h"
datapath: Report kernel's flow key when passing packets up to userspace. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. This commit takes one step in that direction by making the kernel report its idea of the flow that a packet belongs to whenever it passes a packet up to userspace. This means that userspace can intelligently figure out what to do: - If userspace's notion of the flow for the packet matches the kernel's, then nothing special is necessary. - If the kernel has a more specific notion for the flow than userspace, for example if the kernel decoded IPv6 headers but userspace stopped at the Ethernet type (because it does not understand IPv6), then again nothing special is necessary: userspace can still set up the flow in the usual way. - If userspace has a more specific notion for the flow than the kernel, for example if userspace decoded an IPv6 header but the kernel stopped at the Ethernet type, then userspace can forward the packet manually, without setting up a flow in the kernel. (This case is bad from a performance point of view, but at least it is correct.) This commit does not actually make userspace flexible enough to handle changes in the kernel flow key structure, although userspace does now have enough information to do that intelligently. This will have to wait for later commits. This commit is bigger than it would otherwise be because it is rolled together with changing "struct odp_msg" to a sequence of Netlink attributes. The alternative, to do each of those changes in a separate patch, seemed like overkill because it meant that either we would have to introduce and then kill off Netlink attributes for in_port and tun_id, if Netlink conversion went first, or shove yet another variable-length header into the stuff already after odp_msg, if adding the flow key to odp_msg went first. This commit will slow down performance of checksumming packets sent up to userspace. I'm not entirely pleased with how I did it. I considered a couple of alternatives, but none of them seemed that much better. Suggestions welcome. Not changing anything wasn't an option, unfortunately. At any rate some slowdown will become unavoidable when OVS actually starts using Netlink instead of just Netlink framing. (Actually, I thought of one option where we could avoid that: make userspace do the checksum instead, by passing csum_start and csum_offset as part of what goes to userspace. But that's not perfect either.) Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
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#include "netlink.h"
#include "ofpbuf.h"
#include "openvswitch/tunnel.h"
datapath: Report kernel's flow key when passing packets up to userspace. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. This commit takes one step in that direction by making the kernel report its idea of the flow that a packet belongs to whenever it passes a packet up to userspace. This means that userspace can intelligently figure out what to do: - If userspace's notion of the flow for the packet matches the kernel's, then nothing special is necessary. - If the kernel has a more specific notion for the flow than userspace, for example if the kernel decoded IPv6 headers but userspace stopped at the Ethernet type (because it does not understand IPv6), then again nothing special is necessary: userspace can still set up the flow in the usual way. - If userspace has a more specific notion for the flow than the kernel, for example if userspace decoded an IPv6 header but the kernel stopped at the Ethernet type, then userspace can forward the packet manually, without setting up a flow in the kernel. (This case is bad from a performance point of view, but at least it is correct.) This commit does not actually make userspace flexible enough to handle changes in the kernel flow key structure, although userspace does now have enough information to do that intelligently. This will have to wait for later commits. This commit is bigger than it would otherwise be because it is rolled together with changing "struct odp_msg" to a sequence of Netlink attributes. The alternative, to do each of those changes in a separate patch, seemed like overkill because it meant that either we would have to introduce and then kill off Netlink attributes for in_port and tun_id, if Netlink conversion went first, or shove yet another variable-length header into the stuff already after odp_msg, if adding the flow key to odp_msg went first. This commit will slow down performance of checksumming packets sent up to userspace. I'm not entirely pleased with how I did it. I considered a couple of alternatives, but none of them seemed that much better. Suggestions welcome. Not changing anything wasn't an option, unfortunately. At any rate some slowdown will become unavoidable when OVS actually starts using Netlink instead of just Netlink framing. (Actually, I thought of one option where we could avoid that: make userspace do the checksum instead, by passing csum_start and csum_offset as part of what goes to userspace. But that's not perfect either.) Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2011-01-24 14:59:57 -08:00
#include "packets.h"
#include "poll-loop.h"
#include "rtnetlink.h"
#include "rtnetlink-link.h"
#include "shash.h"
#include "svec.h"
#include "util.h"
#include "vlog.h"
VLOG_DEFINE_THIS_MODULE(dpif_linux);
/* Datapath interface for the openvswitch Linux kernel module. */
struct dpif_linux {
struct dpif dpif;
int fd;
/* Used by dpif_linux_get_all_names(). */
char *local_ifname;
int minor;
/* Change notification. */
int local_ifindex; /* Ifindex of local port. */
struct shash changed_ports; /* Ports that have changed. */
struct rtnetlink_notifier port_notifier;
bool change_error;
};
static struct vlog_rate_limit error_rl = VLOG_RATE_LIMIT_INIT(9999, 5);
static int do_ioctl(const struct dpif *, int cmd, const void *arg);
static int lookup_internal_device(const char *name, int *dp_idx, int *port_no);
static int lookup_minor(const char *name, int *minor);
static int finish_open(struct dpif *, const char *local_ifname);
static int get_openvswitch_major(void);
static int create_minor(const char *name, int minor, struct dpif **dpifp);
static int open_minor(int minor, struct dpif **dpifp);
static int make_openvswitch_device(int minor, char **fnp);
static void dpif_linux_port_changed(const struct rtnetlink_link_change *,
void *dpif);
static struct dpif_linux *
dpif_linux_cast(const struct dpif *dpif)
{
dpif_assert_class(dpif, &dpif_linux_class);
return CONTAINER_OF(dpif, struct dpif_linux, dpif);
}
static int
dpif_linux_enumerate(struct svec *all_dps)
{
int major;
int error;
int i;
/* Check that the Open vSwitch module is loaded. */
major = get_openvswitch_major();
if (major < 0) {
return -major;
}
error = 0;
for (i = 0; i < ODP_MAX; i++) {
struct dpif *dpif;
char devname[16];
int retval;
sprintf(devname, "dp%d", i);
retval = dpif_open(devname, "system", &dpif);
if (!retval) {
svec_add(all_dps, devname);
dpif_uninit(dpif, true);
} else if (retval != ENODEV && !error) {
error = retval;
}
}
return error;
}
static int
dpif_linux_open(const struct dpif_class *class OVS_UNUSED, const char *name,
bool create, struct dpif **dpifp)
{
int minor;
minor = !strncmp(name, "dp", 2)
&& isdigit((unsigned char)name[2]) ? atoi(name + 2) : -1;
if (create) {
if (minor >= 0) {
return create_minor(name, minor, dpifp);
} else {
/* Scan for unused minor number. */
for (minor = 0; minor < ODP_MAX; minor++) {
int error = create_minor(name, minor, dpifp);
if (error != EBUSY) {
return error;
}
}
/* All datapath numbers in use. */
return ENOBUFS;
}
} else {
struct dpif_linux *dpif;
struct odp_port port;
int error;
if (minor < 0) {
error = lookup_minor(name, &minor);
if (error) {
return error;
}
}
error = open_minor(minor, dpifp);
if (error) {
return error;
}
dpif = dpif_linux_cast(*dpifp);
/* We need the local port's ifindex for the poll function. Start by
* getting the local port's name. */
memset(&port, 0, sizeof port);
port.port = ODPP_LOCAL;
if (ioctl(dpif->fd, ODP_VPORT_QUERY, &port)) {
error = errno;
if (error != ENODEV) {
VLOG_WARN("%s: probe returned unexpected error: %s",
dpif_name(*dpifp), strerror(error));
}
dpif_uninit(*dpifp, true);
return error;
}
/* Then use that to finish up opening. */
return finish_open(&dpif->dpif, port.devname);
}
}
static void
dpif_linux_close(struct dpif *dpif_)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
rtnetlink_link_notifier_unregister(&dpif->port_notifier);
shash_destroy(&dpif->changed_ports);
free(dpif->local_ifname);
close(dpif->fd);
free(dpif);
}
static int
dpif_linux_get_all_names(const struct dpif *dpif_, struct svec *all_names)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
svec_add_nocopy(all_names, xasprintf("dp%d", dpif->minor));
svec_add(all_names, dpif->local_ifname);
return 0;
}
static int
dpif_linux_destroy(struct dpif *dpif_)
{
return do_ioctl(dpif_, ODP_DP_DESTROY, NULL);
}
static int
dpif_linux_get_stats(const struct dpif *dpif_, struct odp_stats *stats)
{
memset(stats, 0, sizeof *stats);
return do_ioctl(dpif_, ODP_DP_STATS, stats);
}
static int
dpif_linux_get_drop_frags(const struct dpif *dpif_, bool *drop_fragsp)
{
int drop_frags;
int error;
error = do_ioctl(dpif_, ODP_GET_DROP_FRAGS, &drop_frags);
if (!error) {
*drop_fragsp = drop_frags & 1;
}
return error;
}
static int
dpif_linux_set_drop_frags(struct dpif *dpif_, bool drop_frags)
{
int drop_frags_int = drop_frags;
return do_ioctl(dpif_, ODP_SET_DROP_FRAGS, &drop_frags_int);
}
static const char *
vport_type_to_netdev_type(const struct odp_port *odp_port)
{
struct tnl_port_config tnl_config;
switch (odp_port->type) {
case ODP_VPORT_TYPE_UNSPEC:
break;
case ODP_VPORT_TYPE_NETDEV:
return "system";
case ODP_VPORT_TYPE_INTERNAL:
return "internal";
case ODP_VPORT_TYPE_PATCH:
return "patch";
case ODP_VPORT_TYPE_GRE:
memcpy(&tnl_config, odp_port->config, sizeof tnl_config);
return tnl_config.flags & TNL_F_IPSEC ? "ipsec_gre" : "gre";
case ODP_VPORT_TYPE_CAPWAP:
return "capwap";
case __ODP_VPORT_TYPE_MAX:
break;
}
VLOG_WARN_RL(&error_rl, "dp%d: port `%s' has unsupported type %"PRIu32,
odp_port->dp_idx, odp_port->devname, odp_port->type);
return "unknown";
}
static enum odp_vport_type
netdev_type_to_vport_type(const char *type)
{
return (!strcmp(type, "system") ? ODP_VPORT_TYPE_NETDEV
: !strcmp(type, "internal") ? ODP_VPORT_TYPE_INTERNAL
: !strcmp(type, "patch") ? ODP_VPORT_TYPE_PATCH
: (!strcmp(type, "gre")
|| !strcmp(type, "ipsec_gre")) ? ODP_VPORT_TYPE_GRE
: !strcmp(type, "capwap") ? ODP_VPORT_TYPE_CAPWAP
: ODP_VPORT_TYPE_UNSPEC);
}
static int
dpif_linux_port_add(struct dpif *dpif, struct netdev *netdev,
uint16_t *port_nop)
{
const char *name = netdev_get_name(netdev);
const char *type = netdev_get_type(netdev);
struct odp_port port;
int error;
memset(&port, 0, sizeof port);
strncpy(port.devname, name, sizeof port.devname);
netdev_vport_get_config(netdev, port.config);
port.type = netdev_type_to_vport_type(type);
if (port.type == ODP_VPORT_TYPE_UNSPEC) {
VLOG_WARN_RL(&error_rl, "%s: cannot create port `%s' because it has "
"unsupported type `%s'",
dpif_name(dpif), name, type);
return EINVAL;
}
error = do_ioctl(dpif, ODP_VPORT_ATTACH, &port);
if (!error) {
*port_nop = port.port;
}
return error;
}
static int
dpif_linux_port_del(struct dpif *dpif_, uint16_t port_no_)
{
int port_no = port_no_; /* Kernel expects an "int". */
return do_ioctl(dpif_, ODP_VPORT_DETACH, &port_no);
}
static int
dpif_linux_port_query__(const struct dpif *dpif, uint32_t port_no,
const char *port_name, struct dpif_port *dpif_port)
{
struct odp_port odp_port;
int error;
memset(&odp_port, 0, sizeof odp_port);
odp_port.port = port_no;
strncpy(odp_port.devname, port_name, sizeof odp_port.devname);
error = do_ioctl(dpif, ODP_VPORT_QUERY, &odp_port);
if (error) {
return error;
} else if (odp_port.dp_idx != dpif_linux_cast(dpif)->minor) {
/* A vport named 'port_name' exists but in some other datapath. */
return ENOENT;
} else {
dpif_port->name = xstrdup(odp_port.devname);
dpif_port->type = xstrdup(vport_type_to_netdev_type(&odp_port));
dpif_port->port_no = odp_port.port;
return 0;
}
}
static int
dpif_linux_port_query_by_number(const struct dpif *dpif, uint16_t port_no,
struct dpif_port *dpif_port)
{
return dpif_linux_port_query__(dpif, port_no, "", dpif_port);
}
static int
dpif_linux_port_query_by_name(const struct dpif *dpif, const char *devname,
struct dpif_port *dpif_port)
{
return dpif_linux_port_query__(dpif, 0, devname, dpif_port);
}
static int
dpif_linux_flow_flush(struct dpif *dpif_)
{
return do_ioctl(dpif_, ODP_FLOW_FLUSH, NULL);
}
static int
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dpif_linux_port_dump_start(const struct dpif *dpif OVS_UNUSED, void **statep)
{
*statep = xzalloc(sizeof(struct odp_port));
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return 0;
}
static int
dpif_linux_port_dump_next(const struct dpif *dpif, void *state,
struct dpif_port *dpif_port)
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{
struct odp_port *odp_port = state;
struct odp_vport_dump dump;
int error;
dump.port = odp_port;
dump.port_no = odp_port->port;
error = do_ioctl(dpif, ODP_VPORT_DUMP, &dump);
if (error) {
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return error;
} else if (odp_port->devname[0] == '\0') {
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return EOF;
} else {
dpif_port->name = odp_port->devname;
dpif_port->type = (char *) vport_type_to_netdev_type(odp_port);
dpif_port->port_no = odp_port->port;
odp_port->port++;
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return 0;
}
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}
static int
dpif_linux_port_dump_done(const struct dpif *dpif OVS_UNUSED, void *state)
{
free(state);
return 0;
}
static int
dpif_linux_port_poll(const struct dpif *dpif_, char **devnamep)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
if (dpif->change_error) {
dpif->change_error = false;
shash_clear(&dpif->changed_ports);
return ENOBUFS;
} else if (!shash_is_empty(&dpif->changed_ports)) {
struct shash_node *node = shash_first(&dpif->changed_ports);
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*devnamep = shash_steal(&dpif->changed_ports, node);
return 0;
} else {
return EAGAIN;
}
}
static void
dpif_linux_port_poll_wait(const struct dpif *dpif_)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
if (!shash_is_empty(&dpif->changed_ports) || dpif->change_error) {
poll_immediate_wake();
} else {
rtnetlink_link_notifier_wait();
}
}
static int
dpif_linux_flow_get(const struct dpif *dpif_, struct odp_flow flows[], int n)
{
struct odp_flowvec fv;
fv.flows = flows;
fv.n_flows = n;
return do_ioctl(dpif_, ODP_FLOW_GET, &fv);
}
static int
dpif_linux_flow_put(struct dpif *dpif_, struct odp_flow_put *put)
{
return do_ioctl(dpif_, ODP_FLOW_PUT, put);
}
static int
dpif_linux_flow_del(struct dpif *dpif_, struct odp_flow *flow)
{
return do_ioctl(dpif_, ODP_FLOW_DEL, flow);
}
static int
datapath: Change listing flows to use an iterator concept. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. In turn, that means that flow keys must become variable-length. This does not, however, fit in well with the ODP_FLOW_LIST ioctl in its current form, because that would require userspace to know how much space to allocate for each flow's key in advance, or to allocate as much space as could possibly be needed. Neither choice is very attractive. This commit prepares for a different solution, by replacing ODP_FLOW_LIST by a new ioctl ODP_FLOW_DUMP that retrieves a single flow from the datapath on each call. It is much cleaner to allocate the maximum amount of space for a single flow key than to do so for possibly a very large number of flow keys. As a side effect, this patch also fixes a race condition that sometimes made "ovs-dpctl dump-flows" print an error: previously, flows were listed and then their actions were retrieved, which left a window in which ovs-vswitchd could delete the flow. Now dumping a flow and its actions is a single step, closing that window. Dumping all of the flows in a datapath is no longer an atomic step, so now it is possible to miss some flows or see a single flow twice during iteration, if the flow table is modified by another process. It doesn't look like this should be a problem for ovs-vswitchd. It would be faster to retrieve a number of flows in batch instead of just one at a time, but that will naturally happen later when the kernel datapath interface is changed to use Netlink, so this patch does not bother with it. Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2010-12-28 10:39:52 -08:00
dpif_linux_flow_dump_start(const struct dpif *dpif OVS_UNUSED, void **statep)
{
datapath: Change listing flows to use an iterator concept. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. In turn, that means that flow keys must become variable-length. This does not, however, fit in well with the ODP_FLOW_LIST ioctl in its current form, because that would require userspace to know how much space to allocate for each flow's key in advance, or to allocate as much space as could possibly be needed. Neither choice is very attractive. This commit prepares for a different solution, by replacing ODP_FLOW_LIST by a new ioctl ODP_FLOW_DUMP that retrieves a single flow from the datapath on each call. It is much cleaner to allocate the maximum amount of space for a single flow key than to do so for possibly a very large number of flow keys. As a side effect, this patch also fixes a race condition that sometimes made "ovs-dpctl dump-flows" print an error: previously, flows were listed and then their actions were retrieved, which left a window in which ovs-vswitchd could delete the flow. Now dumping a flow and its actions is a single step, closing that window. Dumping all of the flows in a datapath is no longer an atomic step, so now it is possible to miss some flows or see a single flow twice during iteration, if the flow table is modified by another process. It doesn't look like this should be a problem for ovs-vswitchd. It would be faster to retrieve a number of flows in batch instead of just one at a time, but that will naturally happen later when the kernel datapath interface is changed to use Netlink, so this patch does not bother with it. Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2010-12-28 10:39:52 -08:00
*statep = xzalloc(sizeof(struct odp_flow_dump));
return 0;
}
static int
dpif_linux_flow_dump_next(const struct dpif *dpif, void *state,
struct odp_flow *flow)
{
struct odp_flow_dump *dump = state;
int error;
datapath: Change listing flows to use an iterator concept. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. In turn, that means that flow keys must become variable-length. This does not, however, fit in well with the ODP_FLOW_LIST ioctl in its current form, because that would require userspace to know how much space to allocate for each flow's key in advance, or to allocate as much space as could possibly be needed. Neither choice is very attractive. This commit prepares for a different solution, by replacing ODP_FLOW_LIST by a new ioctl ODP_FLOW_DUMP that retrieves a single flow from the datapath on each call. It is much cleaner to allocate the maximum amount of space for a single flow key than to do so for possibly a very large number of flow keys. As a side effect, this patch also fixes a race condition that sometimes made "ovs-dpctl dump-flows" print an error: previously, flows were listed and then their actions were retrieved, which left a window in which ovs-vswitchd could delete the flow. Now dumping a flow and its actions is a single step, closing that window. Dumping all of the flows in a datapath is no longer an atomic step, so now it is possible to miss some flows or see a single flow twice during iteration, if the flow table is modified by another process. It doesn't look like this should be a problem for ovs-vswitchd. It would be faster to retrieve a number of flows in batch instead of just one at a time, but that will naturally happen later when the kernel datapath interface is changed to use Netlink, so this patch does not bother with it. Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2010-12-28 10:39:52 -08:00
dump->flow = flow;
error = do_ioctl(dpif, ODP_FLOW_DUMP, dump);
return error ? error : flow->flags & ODPFF_EOF ? EOF : 0;
}
static int
dpif_linux_flow_dump_done(const struct dpif *dpif OVS_UNUSED, void *state)
{
free(state);
return 0;
}
static int
dpif_linux_execute(struct dpif *dpif_,
const struct nlattr *actions, size_t actions_len,
const struct ofpbuf *buf)
{
struct odp_execute execute;
memset(&execute, 0, sizeof execute);
execute.actions = (struct nlattr *) actions;
execute.actions_len = actions_len;
execute.data = buf->data;
execute.length = buf->size;
return do_ioctl(dpif_, ODP_EXECUTE, &execute);
}
static int
dpif_linux_recv_get_mask(const struct dpif *dpif_, int *listen_mask)
{
return do_ioctl(dpif_, ODP_GET_LISTEN_MASK, listen_mask);
}
static int
dpif_linux_recv_set_mask(struct dpif *dpif_, int listen_mask)
{
return do_ioctl(dpif_, ODP_SET_LISTEN_MASK, &listen_mask);
}
static int
dpif_linux_get_sflow_probability(const struct dpif *dpif_,
uint32_t *probability)
{
return do_ioctl(dpif_, ODP_GET_SFLOW_PROBABILITY, probability);
}
static int
dpif_linux_set_sflow_probability(struct dpif *dpif_, uint32_t probability)
{
return do_ioctl(dpif_, ODP_SET_SFLOW_PROBABILITY, &probability);
}
static int
dpif_linux_queue_to_priority(const struct dpif *dpif OVS_UNUSED,
uint32_t queue_id, uint32_t *priority)
{
if (queue_id < 0xf000) {
*priority = TC_H_MAKE(1 << 16, queue_id + 1);
return 0;
} else {
return EINVAL;
}
}
static int
datapath: Report kernel's flow key when passing packets up to userspace. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. This commit takes one step in that direction by making the kernel report its idea of the flow that a packet belongs to whenever it passes a packet up to userspace. This means that userspace can intelligently figure out what to do: - If userspace's notion of the flow for the packet matches the kernel's, then nothing special is necessary. - If the kernel has a more specific notion for the flow than userspace, for example if the kernel decoded IPv6 headers but userspace stopped at the Ethernet type (because it does not understand IPv6), then again nothing special is necessary: userspace can still set up the flow in the usual way. - If userspace has a more specific notion for the flow than the kernel, for example if userspace decoded an IPv6 header but the kernel stopped at the Ethernet type, then userspace can forward the packet manually, without setting up a flow in the kernel. (This case is bad from a performance point of view, but at least it is correct.) This commit does not actually make userspace flexible enough to handle changes in the kernel flow key structure, although userspace does now have enough information to do that intelligently. This will have to wait for later commits. This commit is bigger than it would otherwise be because it is rolled together with changing "struct odp_msg" to a sequence of Netlink attributes. The alternative, to do each of those changes in a separate patch, seemed like overkill because it meant that either we would have to introduce and then kill off Netlink attributes for in_port and tun_id, if Netlink conversion went first, or shove yet another variable-length header into the stuff already after odp_msg, if adding the flow key to odp_msg went first. This commit will slow down performance of checksumming packets sent up to userspace. I'm not entirely pleased with how I did it. I considered a couple of alternatives, but none of them seemed that much better. Suggestions welcome. Not changing anything wasn't an option, unfortunately. At any rate some slowdown will become unavoidable when OVS actually starts using Netlink instead of just Netlink framing. (Actually, I thought of one option where we could avoid that: make userspace do the checksum instead, by passing csum_start and csum_offset as part of what goes to userspace. But that's not perfect either.) Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2011-01-24 14:59:57 -08:00
parse_odp_packet(struct ofpbuf *buf, struct dpif_upcall *upcall)
{
static const struct nl_policy odp_packet_policy[] = {
/* Always present. */
[ODP_PACKET_ATTR_TYPE] = { .type = NL_A_U32 },
[ODP_PACKET_ATTR_PACKET] = { .type = NL_A_UNSPEC,
.min_len = ETH_HEADER_LEN },
[ODP_PACKET_ATTR_KEY] = { .type = NL_A_NESTED },
/* _ODPL_ACTION_NR only. */
[ODP_PACKET_ATTR_USERDATA] = { .type = NL_A_U64, .optional = true },
/* _ODPL_SFLOW_NR only. */
[ODP_PACKET_ATTR_SAMPLE_POOL] = { .type = NL_A_U32, .optional = true },
[ODP_PACKET_ATTR_ACTIONS] = { .type = NL_A_NESTED, .optional = true },
};
struct odp_packet *odp_packet = buf->data;
struct nlattr *a[ARRAY_SIZE(odp_packet_policy)];
if (!nl_policy_parse(buf, sizeof *odp_packet, odp_packet_policy,
a, ARRAY_SIZE(odp_packet_policy))) {
return EINVAL;
}
memset(upcall, 0, sizeof *upcall);
upcall->type = nl_attr_get_u32(a[ODP_PACKET_ATTR_TYPE]);
upcall->packet = buf;
upcall->packet->data = (void *) nl_attr_get(a[ODP_PACKET_ATTR_PACKET]);
upcall->packet->size = nl_attr_get_size(a[ODP_PACKET_ATTR_PACKET]);
upcall->key = (void *) nl_attr_get(a[ODP_PACKET_ATTR_KEY]);
upcall->key_len = nl_attr_get_size(a[ODP_PACKET_ATTR_KEY]);
upcall->userdata = (a[ODP_PACKET_ATTR_USERDATA]
? nl_attr_get_u64(a[ODP_PACKET_ATTR_USERDATA])
: 0);
upcall->sample_pool = (a[ODP_PACKET_ATTR_SAMPLE_POOL]
? nl_attr_get_u32(a[ODP_PACKET_ATTR_SAMPLE_POOL])
: 0);
if (a[ODP_PACKET_ATTR_ACTIONS]) {
upcall->actions = (void *) nl_attr_get(a[ODP_PACKET_ATTR_ACTIONS]);
upcall->actions_len = nl_attr_get_size(a[ODP_PACKET_ATTR_ACTIONS]);
}
return 0;
}
static int
dpif_linux_recv(struct dpif *dpif_, struct dpif_upcall *upcall)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
struct ofpbuf *buf;
int retval;
int error;
datapath: Report kernel's flow key when passing packets up to userspace. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. This commit takes one step in that direction by making the kernel report its idea of the flow that a packet belongs to whenever it passes a packet up to userspace. This means that userspace can intelligently figure out what to do: - If userspace's notion of the flow for the packet matches the kernel's, then nothing special is necessary. - If the kernel has a more specific notion for the flow than userspace, for example if the kernel decoded IPv6 headers but userspace stopped at the Ethernet type (because it does not understand IPv6), then again nothing special is necessary: userspace can still set up the flow in the usual way. - If userspace has a more specific notion for the flow than the kernel, for example if userspace decoded an IPv6 header but the kernel stopped at the Ethernet type, then userspace can forward the packet manually, without setting up a flow in the kernel. (This case is bad from a performance point of view, but at least it is correct.) This commit does not actually make userspace flexible enough to handle changes in the kernel flow key structure, although userspace does now have enough information to do that intelligently. This will have to wait for later commits. This commit is bigger than it would otherwise be because it is rolled together with changing "struct odp_msg" to a sequence of Netlink attributes. The alternative, to do each of those changes in a separate patch, seemed like overkill because it meant that either we would have to introduce and then kill off Netlink attributes for in_port and tun_id, if Netlink conversion went first, or shove yet another variable-length header into the stuff already after odp_msg, if adding the flow key to odp_msg went first. This commit will slow down performance of checksumming packets sent up to userspace. I'm not entirely pleased with how I did it. I considered a couple of alternatives, but none of them seemed that much better. Suggestions welcome. Not changing anything wasn't an option, unfortunately. At any rate some slowdown will become unavoidable when OVS actually starts using Netlink instead of just Netlink framing. (Actually, I thought of one option where we could avoid that: make userspace do the checksum instead, by passing csum_start and csum_offset as part of what goes to userspace. But that's not perfect either.) Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2011-01-24 14:59:57 -08:00
buf = ofpbuf_new(65536);
retval = read(dpif->fd, ofpbuf_tail(buf), ofpbuf_tailroom(buf));
if (retval < 0) {
error = errno;
if (error != EAGAIN) {
VLOG_WARN_RL(&error_rl, "%s: read failed: %s",
dpif_name(dpif_), strerror(error));
}
datapath: Report kernel's flow key when passing packets up to userspace. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. This commit takes one step in that direction by making the kernel report its idea of the flow that a packet belongs to whenever it passes a packet up to userspace. This means that userspace can intelligently figure out what to do: - If userspace's notion of the flow for the packet matches the kernel's, then nothing special is necessary. - If the kernel has a more specific notion for the flow than userspace, for example if the kernel decoded IPv6 headers but userspace stopped at the Ethernet type (because it does not understand IPv6), then again nothing special is necessary: userspace can still set up the flow in the usual way. - If userspace has a more specific notion for the flow than the kernel, for example if userspace decoded an IPv6 header but the kernel stopped at the Ethernet type, then userspace can forward the packet manually, without setting up a flow in the kernel. (This case is bad from a performance point of view, but at least it is correct.) This commit does not actually make userspace flexible enough to handle changes in the kernel flow key structure, although userspace does now have enough information to do that intelligently. This will have to wait for later commits. This commit is bigger than it would otherwise be because it is rolled together with changing "struct odp_msg" to a sequence of Netlink attributes. The alternative, to do each of those changes in a separate patch, seemed like overkill because it meant that either we would have to introduce and then kill off Netlink attributes for in_port and tun_id, if Netlink conversion went first, or shove yet another variable-length header into the stuff already after odp_msg, if adding the flow key to odp_msg went first. This commit will slow down performance of checksumming packets sent up to userspace. I'm not entirely pleased with how I did it. I considered a couple of alternatives, but none of them seemed that much better. Suggestions welcome. Not changing anything wasn't an option, unfortunately. At any rate some slowdown will become unavoidable when OVS actually starts using Netlink instead of just Netlink framing. (Actually, I thought of one option where we could avoid that: make userspace do the checksum instead, by passing csum_start and csum_offset as part of what goes to userspace. But that's not perfect either.) Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2011-01-24 14:59:57 -08:00
} else if (retval >= sizeof(struct odp_packet)) {
struct odp_packet *odp_packet = buf->data;
buf->size += retval;
if (odp_packet->len <= retval) {
error = parse_odp_packet(buf, upcall);
} else {
VLOG_WARN_RL(&error_rl, "%s: discarding message truncated "
2009-11-10 15:12:01 -08:00
"from %"PRIu32" bytes to %d",
datapath: Report kernel's flow key when passing packets up to userspace. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. This commit takes one step in that direction by making the kernel report its idea of the flow that a packet belongs to whenever it passes a packet up to userspace. This means that userspace can intelligently figure out what to do: - If userspace's notion of the flow for the packet matches the kernel's, then nothing special is necessary. - If the kernel has a more specific notion for the flow than userspace, for example if the kernel decoded IPv6 headers but userspace stopped at the Ethernet type (because it does not understand IPv6), then again nothing special is necessary: userspace can still set up the flow in the usual way. - If userspace has a more specific notion for the flow than the kernel, for example if userspace decoded an IPv6 header but the kernel stopped at the Ethernet type, then userspace can forward the packet manually, without setting up a flow in the kernel. (This case is bad from a performance point of view, but at least it is correct.) This commit does not actually make userspace flexible enough to handle changes in the kernel flow key structure, although userspace does now have enough information to do that intelligently. This will have to wait for later commits. This commit is bigger than it would otherwise be because it is rolled together with changing "struct odp_msg" to a sequence of Netlink attributes. The alternative, to do each of those changes in a separate patch, seemed like overkill because it meant that either we would have to introduce and then kill off Netlink attributes for in_port and tun_id, if Netlink conversion went first, or shove yet another variable-length header into the stuff already after odp_msg, if adding the flow key to odp_msg went first. This commit will slow down performance of checksumming packets sent up to userspace. I'm not entirely pleased with how I did it. I considered a couple of alternatives, but none of them seemed that much better. Suggestions welcome. Not changing anything wasn't an option, unfortunately. At any rate some slowdown will become unavoidable when OVS actually starts using Netlink instead of just Netlink framing. (Actually, I thought of one option where we could avoid that: make userspace do the checksum instead, by passing csum_start and csum_offset as part of what goes to userspace. But that's not perfect either.) Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2011-01-24 14:59:57 -08:00
dpif_name(dpif_), odp_packet->len, retval);
error = ERANGE;
}
} else if (!retval) {
VLOG_WARN_RL(&error_rl, "%s: unexpected end of file", dpif_name(dpif_));
error = EPROTO;
} else {
datapath: Report kernel's flow key when passing packets up to userspace. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. This commit takes one step in that direction by making the kernel report its idea of the flow that a packet belongs to whenever it passes a packet up to userspace. This means that userspace can intelligently figure out what to do: - If userspace's notion of the flow for the packet matches the kernel's, then nothing special is necessary. - If the kernel has a more specific notion for the flow than userspace, for example if the kernel decoded IPv6 headers but userspace stopped at the Ethernet type (because it does not understand IPv6), then again nothing special is necessary: userspace can still set up the flow in the usual way. - If userspace has a more specific notion for the flow than the kernel, for example if userspace decoded an IPv6 header but the kernel stopped at the Ethernet type, then userspace can forward the packet manually, without setting up a flow in the kernel. (This case is bad from a performance point of view, but at least it is correct.) This commit does not actually make userspace flexible enough to handle changes in the kernel flow key structure, although userspace does now have enough information to do that intelligently. This will have to wait for later commits. This commit is bigger than it would otherwise be because it is rolled together with changing "struct odp_msg" to a sequence of Netlink attributes. The alternative, to do each of those changes in a separate patch, seemed like overkill because it meant that either we would have to introduce and then kill off Netlink attributes for in_port and tun_id, if Netlink conversion went first, or shove yet another variable-length header into the stuff already after odp_msg, if adding the flow key to odp_msg went first. This commit will slow down performance of checksumming packets sent up to userspace. I'm not entirely pleased with how I did it. I considered a couple of alternatives, but none of them seemed that much better. Suggestions welcome. Not changing anything wasn't an option, unfortunately. At any rate some slowdown will become unavoidable when OVS actually starts using Netlink instead of just Netlink framing. (Actually, I thought of one option where we could avoid that: make userspace do the checksum instead, by passing csum_start and csum_offset as part of what goes to userspace. But that's not perfect either.) Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2011-01-24 14:59:57 -08:00
VLOG_WARN_RL(&error_rl, "%s: discarding too-short message (%d bytes)",
dpif_name(dpif_), retval);
error = ERANGE;
}
datapath: Report kernel's flow key when passing packets up to userspace. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. This commit takes one step in that direction by making the kernel report its idea of the flow that a packet belongs to whenever it passes a packet up to userspace. This means that userspace can intelligently figure out what to do: - If userspace's notion of the flow for the packet matches the kernel's, then nothing special is necessary. - If the kernel has a more specific notion for the flow than userspace, for example if the kernel decoded IPv6 headers but userspace stopped at the Ethernet type (because it does not understand IPv6), then again nothing special is necessary: userspace can still set up the flow in the usual way. - If userspace has a more specific notion for the flow than the kernel, for example if userspace decoded an IPv6 header but the kernel stopped at the Ethernet type, then userspace can forward the packet manually, without setting up a flow in the kernel. (This case is bad from a performance point of view, but at least it is correct.) This commit does not actually make userspace flexible enough to handle changes in the kernel flow key structure, although userspace does now have enough information to do that intelligently. This will have to wait for later commits. This commit is bigger than it would otherwise be because it is rolled together with changing "struct odp_msg" to a sequence of Netlink attributes. The alternative, to do each of those changes in a separate patch, seemed like overkill because it meant that either we would have to introduce and then kill off Netlink attributes for in_port and tun_id, if Netlink conversion went first, or shove yet another variable-length header into the stuff already after odp_msg, if adding the flow key to odp_msg went first. This commit will slow down performance of checksumming packets sent up to userspace. I'm not entirely pleased with how I did it. I considered a couple of alternatives, but none of them seemed that much better. Suggestions welcome. Not changing anything wasn't an option, unfortunately. At any rate some slowdown will become unavoidable when OVS actually starts using Netlink instead of just Netlink framing. (Actually, I thought of one option where we could avoid that: make userspace do the checksum instead, by passing csum_start and csum_offset as part of what goes to userspace. But that's not perfect either.) Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2011-01-24 14:59:57 -08:00
if (error) {
ofpbuf_delete(buf);
}
return error;
}
static void
dpif_linux_recv_wait(struct dpif *dpif_)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
poll_fd_wait(dpif->fd, POLLIN);
}
const struct dpif_class dpif_linux_class = {
"system",
NULL,
NULL,
dpif_linux_enumerate,
dpif_linux_open,
dpif_linux_close,
dpif_linux_get_all_names,
dpif_linux_destroy,
dpif_linux_get_stats,
dpif_linux_get_drop_frags,
dpif_linux_set_drop_frags,
dpif_linux_port_add,
dpif_linux_port_del,
dpif_linux_port_query_by_number,
dpif_linux_port_query_by_name,
2011-01-10 13:12:12 -08:00
dpif_linux_port_dump_start,
dpif_linux_port_dump_next,
dpif_linux_port_dump_done,
dpif_linux_port_poll,
dpif_linux_port_poll_wait,
dpif_linux_flow_get,
dpif_linux_flow_put,
dpif_linux_flow_del,
dpif_linux_flow_flush,
datapath: Change listing flows to use an iterator concept. One of the goals for Open vSwitch is to decouple kernel and userspace software, so that either one can be upgraded or rolled back independent of the other. To do this in full generality, it must be possible to change the kernel's idea of the flow key separately from the userspace version. In turn, that means that flow keys must become variable-length. This does not, however, fit in well with the ODP_FLOW_LIST ioctl in its current form, because that would require userspace to know how much space to allocate for each flow's key in advance, or to allocate as much space as could possibly be needed. Neither choice is very attractive. This commit prepares for a different solution, by replacing ODP_FLOW_LIST by a new ioctl ODP_FLOW_DUMP that retrieves a single flow from the datapath on each call. It is much cleaner to allocate the maximum amount of space for a single flow key than to do so for possibly a very large number of flow keys. As a side effect, this patch also fixes a race condition that sometimes made "ovs-dpctl dump-flows" print an error: previously, flows were listed and then their actions were retrieved, which left a window in which ovs-vswitchd could delete the flow. Now dumping a flow and its actions is a single step, closing that window. Dumping all of the flows in a datapath is no longer an atomic step, so now it is possible to miss some flows or see a single flow twice during iteration, if the flow table is modified by another process. It doesn't look like this should be a problem for ovs-vswitchd. It would be faster to retrieve a number of flows in batch instead of just one at a time, but that will naturally happen later when the kernel datapath interface is changed to use Netlink, so this patch does not bother with it. Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Jesse Gross <jesse@nicira.com>
2010-12-28 10:39:52 -08:00
dpif_linux_flow_dump_start,
dpif_linux_flow_dump_next,
dpif_linux_flow_dump_done,
dpif_linux_execute,
dpif_linux_recv_get_mask,
dpif_linux_recv_set_mask,
dpif_linux_get_sflow_probability,
dpif_linux_set_sflow_probability,
dpif_linux_queue_to_priority,
dpif_linux_recv,
dpif_linux_recv_wait,
};
static int get_openvswitch_major(void);
static int get_major(const char *target);
static int
do_ioctl(const struct dpif *dpif_, int cmd, const void *arg)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
return ioctl(dpif->fd, cmd, arg) ? errno : 0;
}
static int
lookup_internal_device(const char *name, int *dp_idx, int *port_no)
{
struct odp_port odp_port;
static int dp0_fd = -1;
if (dp0_fd < 0) {
int error;
char *fn;
error = make_openvswitch_device(0, &fn);
if (error) {
return error;
}
dp0_fd = open(fn, O_RDONLY | O_NONBLOCK);
if (dp0_fd < 0) {
VLOG_WARN_RL(&error_rl, "%s: open failed (%s)",
fn, strerror(errno));
free(fn);
return errno;
}
free(fn);
}
memset(&odp_port, 0, sizeof odp_port);
strncpy(odp_port.devname, name, sizeof odp_port.devname);
if (ioctl(dp0_fd, ODP_VPORT_QUERY, &odp_port)) {
if (errno != ENODEV) {
VLOG_WARN_RL(&error_rl, "%s: vport query failed (%s)",
name, strerror(errno));
}
return errno;
} else if (odp_port.type == ODP_VPORT_TYPE_INTERNAL) {
*dp_idx = odp_port.dp_idx;
*port_no = odp_port.port;
return 0;
} else {
return EINVAL;
}
}
static int
lookup_minor(const char *name, int *minorp)
{
int minor, port_no;
int error;
error = lookup_internal_device(name, &minor, &port_no);
if (error) {
return error;
} else if (port_no != ODPP_LOCAL) {
/* This is an Open vSwitch device but not the local port. We
* intentionally support only using the name of the local port as the
* name of a datapath; otherwise, it would be too difficult to
* enumerate all the names of a datapath. */
return EOPNOTSUPP;
} else {
*minorp = minor;
return 0;
}
}
bool
dpif_linux_is_internal_device(const char *name)
{
int minor, port_no;
return !lookup_internal_device(name, &minor, &port_no);
}
static int
make_openvswitch_device(int minor, char **fnp)
{
const char dirname[] = "/dev/net";
int major;
dev_t dev;
struct stat s;
char fn[128];
*fnp = NULL;
major = get_openvswitch_major();
if (major < 0) {
return -major;
}
dev = makedev(major, minor);
sprintf(fn, "%s/dp%d", dirname, minor);
if (!stat(fn, &s)) {
if (!S_ISCHR(s.st_mode)) {
VLOG_WARN_RL(&error_rl, "%s is not a character device, fixing",
fn);
} else if (s.st_rdev != dev) {
VLOG_WARN_RL(&error_rl,
"%s is device %u:%u but should be %u:%u, fixing",
fn, major(s.st_rdev), minor(s.st_rdev),
major(dev), minor(dev));
} else {
goto success;
}
if (unlink(fn)) {
VLOG_WARN_RL(&error_rl, "%s: unlink failed (%s)",
fn, strerror(errno));
return errno;
}
} else if (errno == ENOENT) {
if (stat(dirname, &s)) {
if (errno == ENOENT) {
if (mkdir(dirname, 0755)) {
VLOG_WARN_RL(&error_rl, "%s: mkdir failed (%s)",
dirname, strerror(errno));
return errno;
}
} else {
VLOG_WARN_RL(&error_rl, "%s: stat failed (%s)",
dirname, strerror(errno));
return errno;
}
}
} else {
VLOG_WARN_RL(&error_rl, "%s: stat failed (%s)", fn, strerror(errno));
return errno;
}
/* The device needs to be created. */
if (mknod(fn, S_IFCHR | 0700, dev)) {
VLOG_WARN_RL(&error_rl,
"%s: creating character device %u:%u failed (%s)",
fn, major(dev), minor(dev), strerror(errno));
return errno;
}
success:
*fnp = xstrdup(fn);
return 0;
}
/* Return the major device number of the Open vSwitch device. If it
* cannot be determined, a negative errno is returned. */
static int
get_openvswitch_major(void)
{
static int openvswitch_major = -1;
if (openvswitch_major < 0) {
openvswitch_major = get_major("openvswitch");
}
return openvswitch_major;
}
static int
get_major(const char *target)
{
const char fn[] = "/proc/devices";
char line[128];
FILE *file;
int ln;
file = fopen(fn, "r");
if (!file) {
VLOG_ERR("opening %s failed (%s)", fn, strerror(errno));
return -errno;
}
for (ln = 1; fgets(line, sizeof line, file); ln++) {
char name[64];
int major;
if (!strncmp(line, "Character", 9) || line[0] == '\0') {
/* Nothing to do. */
} else if (!strncmp(line, "Block", 5)) {
/* We only want character devices, so skip the rest of the file. */
break;
} else if (sscanf(line, "%d %63s", &major, name)) {
if (!strcmp(name, target)) {
fclose(file);
return major;
}
} else {
VLOG_WARN_ONCE("%s:%d: syntax error", fn, ln);
}
}
fclose(file);
VLOG_ERR("%s: %s major not found (is the module loaded?)", fn, target);
return -ENODEV;
}
static int
finish_open(struct dpif *dpif_, const char *local_ifname)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
dpif->local_ifname = xstrdup(local_ifname);
dpif->local_ifindex = if_nametoindex(local_ifname);
if (!dpif->local_ifindex) {
int error = errno;
dpif_uninit(dpif_, true);
VLOG_WARN("could not get ifindex of %s device: %s",
local_ifname, strerror(errno));
return error;
}
return 0;
}
static int
create_minor(const char *name, int minor, struct dpif **dpifp)
{
int error = open_minor(minor, dpifp);
if (!error) {
error = do_ioctl(*dpifp, ODP_DP_CREATE, name);
if (!error) {
error = finish_open(*dpifp, name);
} else {
dpif_uninit(*dpifp, true);
}
}
return error;
}
static int
open_minor(int minor, struct dpif **dpifp)
{
int error;
char *fn;
int fd;
error = make_openvswitch_device(minor, &fn);
if (error) {
return error;
}
fd = open(fn, O_RDONLY | O_NONBLOCK);
if (fd >= 0) {
struct dpif_linux *dpif = xmalloc(sizeof *dpif);
error = rtnetlink_link_notifier_register(&dpif->port_notifier,
dpif_linux_port_changed,
dpif);
if (!error) {
char *name;
name = xasprintf("dp%d", minor);
dpif_init(&dpif->dpif, &dpif_linux_class, name, minor, minor);
free(name);
dpif->fd = fd;
dpif->local_ifname = NULL;
dpif->minor = minor;
dpif->local_ifindex = 0;
shash_init(&dpif->changed_ports);
dpif->change_error = false;
*dpifp = &dpif->dpif;
} else {
free(dpif);
}
} else {
error = errno;
VLOG_WARN("%s: open failed (%s)", fn, strerror(error));
}
free(fn);
return error;
}
static void
dpif_linux_port_changed(const struct rtnetlink_link_change *change,
void *dpif_)
{
struct dpif_linux *dpif = dpif_;
if (change) {
if (change->master_ifindex == dpif->local_ifindex
&& (change->nlmsg_type == RTM_NEWLINK
|| change->nlmsg_type == RTM_DELLINK))
{
/* Our datapath changed, either adding a new port or deleting an
* existing one. */
shash_add_once(&dpif->changed_ports, change->ifname, NULL);
}
} else {
dpif->change_error = true;
}
}