Incorporates suggestions from Justin.
% ./configure --with-l24=/lib/modules/`uname -r`/build
+If you have hardware that supports accelerated OpenFlow switching, and
+you have obtained a hardware table module for your hardware and
+extracted it into the OpenFlow reference distribution source tree,
+then you may also enable building support for the hardware switching
+table with --enable-hw-tables. For example, if your hardware
+switching table is in a directory named datapath/hwtable-foomatic, you
+could compile support for it with the running Linux 2.6 kernel like
+so:
+
+ % ./configure --with-l26=/lib/modules/`uname -r`/build \
+ --enable-hw-tables=foomatic
+
+For more information about hardware table modules, please read
+README.hwtables at the root of the OpenFlow distribution tree.
+
In addition to the binaries listed under step 2 in "Building Userspace
Programs" above, "make" will build the following kernel modules:
datapath/linux-2.6/openflow_mod.ko (if --with-l26 was specified)
datapath/linux-2.4/openflow_mod.o (if --with-l24 was specified)
+"make" will also build a kernel module for each hardware switch table
+enabled with --enable-hw-tables.
+
Once you have built the kernel modules, activating them requires only
running "insmod", e.g.:
% insmod datapath/linux-2.4/compat24_mod.o
% insmod datapath/linux-2.4/openflow_mod.o
+After you load the openflow module, you may load one hardware switch
+table module (if any were built) to enable support for that hardware
+switching table.
+
The insmod program must be run as root. You may need to specify a
full path to insmod, which is usually in the /sbin directory. To
verify that the modules have been loaded, run "lsmod" (also in /sbin)
# dpctl adddp 0
- (In principle, openflow_mod supports multiple datapaths within the
- same host, but this is rarely useful in practice.)
+ In principle, openflow_mod supports multiple datapaths within the
+ same host, but this is rarely useful in practice.
+
+ If you built a support module for hardware accelerated OpenFlow
+ switching and you want to use it, you must load it before creating
+ the datapath with "dpctl adddp".
2. Use dpctl to attach the datapath to physical interfaces on the
machine. Say, for example, you want to create a trivial 2-port
--- /dev/null
+Hardware Table Support -*- text -*-
+----------------------
+
+The OpenFlow reference implementation in this distribution provides a
+mechanism to support hardware that can accelerate OpenFlow switching.
+The mechanism consists of the ability to add a "hardware acceleration"
+switching table ahead of the software switching tables implemented by
+the reference implementation. The hardware switching table is
+expected to handle any incoming packets that it can on its own. Any
+packets that it cannot handle itself it may pass up to the software
+table implementations.
+
+Hardware table implementation are built as separate kernel modules
+that may be loaded after the openflow module. At most one hardware
+table module may be loaded at a time. Only datapaths created after a
+hardware table module is loaded (and before it is unloaded) will take
+advantage of hardware switching features.
+
+Creating a hardware table module is straightforward. Create a
+directory in the openflow source tree named datapath/hwtable-NAME,
+where NAME identifies the hardware that the module supports. Populate
+that directory with the C source files that comprise the module, plus
+a file named Modules.mk that specifies how to build the module. This
+distribution includes a "dummy" hardware module that demonstrates how
+this works.
+
+Even though only one may be loaded at a given time, any number of
+hardware table modules may be built along with the OpenFlow kernel
+modules. Specify each NAME that identifies a module to be built on
+the OpenFlow configure script command as the argument to
+--enable-hw-tables, e.g.:
+ ./configure --enable-hw-tables=NAME
+
+Each hardware table module's code is encapsulated in a directory, so
+it is easy to separate a hardware table implementation from OpenFlow.
+Simply package up the contents of the hwtable-NAME directory and
+distribute it for builders to extract into their distribution
+directory.
[ndebug=false])
AM_CONDITIONAL([NDEBUG], [test x$ndebug = xtrue])
+AC_ARG_ENABLE(
+ [hw-tables],
+ [AC_HELP_STRING([--enable-hw-tables=MODULE...],
+ [Configure and build the specified externally supplied
+ hardware table support modules])])
+case "${enable_hw_tables}" in # (
+ yes)
+ AC_MSG_ERROR([--enable-hw-tables has a required argument])
+ ;; # (
+ ''|no)
+ hw_tables=
+ ;; # (
+ *)
+ hw_tables=`echo "$enable_hw_tables" | sed 's/,/ /g'`
+ ;;
+esac
+for d in $hw_tables; do
+ mk=datapath/hwtable-$d/Modules.mk
+ if test ! -e $srcdir/$mk; then
+ AC_MSG_ERROR([--enable-hw-tables=$d specified but $mk is missing])
+ fi
+ HW_TABLES="$HW_TABLES \$(top_srcdir)/$mk"
+done
+AC_SUBST(HW_TABLES)
+
CHECK_LINUX(l26, 2.6, 2.6, KSRC26, L26_ENABLED)
CHECK_LINUX(l24, 2.4, 2.4, KSRC24, L24_ENABLED)
#include "chain.h"
#include "flow.h"
#include "table.h"
+#include <linux/module.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+static struct sw_table *(*create_hw_table_hook)(void);
+static struct module *hw_table_owner;
+static DEFINE_SPINLOCK(hook_lock);
/* Attempts to append 'table' to the set of tables in 'chain'. Returns 0 or
* negative error. If 'table' is null it is assumed that table creation failed
{
struct sw_chain *chain = kzalloc(sizeof *chain, GFP_KERNEL);
if (chain == NULL)
- return NULL;
+ goto error;
chain->dp = dp;
+ chain->owner = try_module_get(hw_table_owner) ? hw_table_owner : NULL;
+ if (chain->owner && create_hw_table_hook) {
+ struct sw_table *hwtable = create_hw_table_hook();
+ if (!hwtable || add_table(chain, hwtable))
+ goto error;
+ }
if (add_table(chain, table_hash2_create(0x1EDC6F41, TABLE_HASH_MAX_FLOWS,
0x741B8CD7, TABLE_HASH_MAX_FLOWS))
- || add_table(chain, table_linear_create(TABLE_LINEAR_MAX_FLOWS))) {
- chain_destroy(chain);
- return NULL;
- }
-
+ || add_table(chain, table_linear_create(TABLE_LINEAR_MAX_FLOWS)))
+ goto error;
return chain;
+
+error:
+ if (chain)
+ chain_destroy(chain);
+ return NULL;
}
/* Searches 'chain' for a flow matching 'key', which must not have any wildcard
struct sw_table *t = chain->tables[i];
t->destroy(t);
}
+ module_put(chain->owner);
kfree(chain);
}
stats.name, stats.n_flows, stats.max_flows);
}
}
+
+
+int chain_set_hw_hook(struct sw_table *(*create_hw_table)(void),
+ struct module *owner)
+{
+ int retval = -EBUSY;
+
+ spin_lock(&hook_lock);
+ if (!create_hw_table_hook) {
+ create_hw_table_hook = create_hw_table;
+ hw_table_owner = owner;
+ retval = 0;
+ }
+ spin_unlock(&hook_lock);
+
+ return retval;
+}
+EXPORT_SYMBOL(chain_set_hw_hook);
+
+void chain_clear_hw_hook(void)
+{
+ create_hw_table_hook = NULL;
+ hw_table_owner = NULL;
+}
+EXPORT_SYMBOL(chain_clear_hw_hook);
struct sw_table *tables[CHAIN_MAX_TABLES];
struct datapath *dp;
+ struct module *owner;
};
struct sw_chain *chain_create(struct datapath *);
void chain_destroy(struct sw_chain *);
void chain_print_stats(struct sw_chain *);
+int chain_set_hw_hook(struct sw_table *(*create_hw_table)(void),
+ struct module *owner);
+void chain_clear_hw_hook(void);
+
#endif /* chain.h */
return send_openflow_skb(skb, NULL);
}
+EXPORT_SYMBOL(dp_send_flow_expired);
int
dp_send_error_msg(struct datapath *dp, const struct sender *sender,
#include <net/llc_pdu.h>
#include <linux/ip.h>
#include <linux/kernel.h>
+#include <linux/module.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/in.h>
/* Returns nonzero if 'a' and 'b' match, that is, if their fields are equal
* modulo wildcards, zero otherwise. */
-inline
int flow_matches(const struct sw_flow_key *a, const struct sw_flow_key *b)
{
return flow_fields_match(a, b, (a->wildcards | b->wildcards));
}
+EXPORT_SYMBOL(flow_matches);
/* Returns nonzero if 't' (the table entry's key) and 'd' (the key
* describing the deletion) match, that is, if their fields are
* equal modulo wildcards, zero otherwise. If 'strict' is nonzero, the
* wildcards must match in both 't_key' and 'd_key'. Note that the
* table's wildcards are ignored unless 'strict' is set. */
-inline
int flow_del_matches(const struct sw_flow_key *t, const struct sw_flow_key *d, int strict)
{
if (strict && (t->wildcards != d->wildcards))
return flow_fields_match(t, d, d->wildcards);
}
+EXPORT_SYMBOL(flow_del_matches);
void flow_extract_match(struct sw_flow_key* to, const struct ofp_match* from)
{
{
return !atomic_cmpxchg(&flow->deleted, 0, 1);
}
+EXPORT_SYMBOL(flow_del);
/* Allocates and returns a new flow with 'n_actions' action, using allocation
* flags 'flags'. Returns the new flow or a null pointer on failure. */
kfree(flow->actions);
kmem_cache_free(flow_cache, flow);
}
+EXPORT_SYMBOL(flow_free);
/* RCU callback used by flow_deferred_free. */
static void rcu_callback(struct rcu_head *rcu)
{
call_rcu(&flow->rcu, rcu_callback);
}
+EXPORT_SYMBOL(flow_deferred_free);
/* Prints a representation of 'key' to the kernel log. */
void print_flow(const struct sw_flow_key *key)
((unsigned char *)&key->nw_dst)[3],
ntohs(key->tp_src), ntohs(key->tp_dst));
}
+EXPORT_SYMBOL(print_flow);
/* Parses the Ethernet frame in 'skb', which was received on 'in_port',
* and initializes 'key' to match. */
struct list_head node;
struct list_head iter_node;
unsigned long serial;
+ void *private;
spinlock_t lock; /* Lock this entry...mostly for stat updates */
unsigned long init_time; /* When the flow was created (in jiffies). */
--- /dev/null
+# Specify the module to build.
+all_modules += hwtable-dummy
+
+# Specify the source files that comprise the module.
+hwtable-dummy_sources = \
+ hwtable-dummy/hwtable-dummy.c
--- /dev/null
+
+#include <linux/module.h>
+#include <linux/rcupdate.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/delay.h>
+#include <linux/if_arp.h>
+
+#include "chain.h"
+#include "table.h"
+#include "flow.h"
+#include "datapath.h"
+
+
+/* Max number of flow entries supported by the hardware */
+#define DUMMY_MAX_FLOW 8192
+
+
+/* xxx Explain need for this separate list because of RCU */
+static spinlock_t pending_free_lock;
+static struct list_head pending_free_list;
+
+/* sw_flow private data for dummy table entries. */
+struct sw_flow_dummy {
+ struct list_head node;
+
+ /* xxx If per-entry data is needed, define it here. */
+};
+
+struct sw_table_dummy {
+ struct sw_table swt;
+
+ spinlock_t lock;
+ unsigned int max_flows;
+ atomic_t n_flows;
+ struct list_head flows;
+ struct list_head iter_flows;
+ unsigned long int next_serial;
+};
+
+
+static void table_dummy_sfw_destroy(struct sw_flow_dummy *sfw)
+{
+ /* xxx Remove the entry from hardware. If you need to do any other
+ * xxx clean-up associated with the entry, do it here.
+ */
+
+ kfree(sfw);
+}
+
+static void table_dummy_rcu_callback(struct rcu_head *rcu)
+{
+ struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
+
+ spin_lock(&pending_free_lock);
+ if (flow->private) {
+ struct sw_flow_dummy *sfw = flow->private;
+ list_add(&sfw->node, &pending_free_list);
+ flow->private = NULL;
+ }
+ spin_unlock(&pending_free_lock);
+ flow_free(flow);
+}
+
+static void table_dummy_flow_deferred_free(struct sw_flow *flow)
+{
+ call_rcu(&flow->rcu, table_dummy_rcu_callback);
+}
+
+static struct sw_flow *table_dummy_lookup(struct sw_table *swt,
+ const struct sw_flow_key *key)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
+ struct sw_flow *flow;
+ list_for_each_entry (flow, &td->flows, node) {
+ if (flow_matches(&flow->key, key)) {
+ printk("found!\n");
+ return flow;
+ }
+ }
+ return NULL;
+}
+
+static int table_dummy_insert(struct sw_table *swt, struct sw_flow *flow)
+{
+ /* xxx Use a data cache? */
+ flow->private = kzalloc(sizeof(struct sw_flow_dummy), GFP_ATOMIC);
+ if (flow->private == NULL)
+ return 0;
+
+ /* xxx Do whatever needs to be done to insert an entry in hardware.
+ * xxx If the entry can't be inserted, return 0. This stub code
+ * xxx doesn't do anything yet, so we're going to return 0...you
+ * xxx shouldn't.
+ */
+ kfree(flow->private);
+ return 0;
+}
+
+
+static int do_delete(struct sw_table *swt, struct sw_flow *flow)
+{
+ if (flow_del(flow)) {
+ list_del_rcu(&flow->node);
+ table_dummy_flow_deferred_free(flow);
+ return 1;
+ }
+ return 0;
+}
+
+static int table_dummy_delete(struct sw_table *swt,
+ const struct sw_flow_key *key, uint16_t priority, int strict)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
+ struct sw_flow *flow;
+ unsigned int count = 0;
+
+ list_for_each_entry_rcu (flow, &td->flows, node) {
+ if (flow_del_matches(&flow->key, key, strict)
+ && (!strict || (flow->priority == priority)))
+ count += do_delete(swt, flow);
+ }
+ if (count)
+ atomic_sub(count, &td->n_flows);
+ return count;
+}
+
+
+static int table_dummy_timeout(struct datapath *dp, struct sw_table *swt)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
+ struct sw_flow *flow;
+ struct sw_flow_dummy *sfw, *n;
+ int del_count = 0;
+ uint64_t packet_count = 0;
+ int i=0;
+
+ list_for_each_entry_rcu (flow, &td->flows, node) {
+ /* xxx Retrieve the packet count associated with this entry
+ * xxx and store it in "packet_count".
+ */
+
+ if ((packet_count > flow->packet_count)
+ && (flow->max_idle != OFP_FLOW_PERMANENT)) {
+ flow->packet_count = packet_count;
+ flow->timeout = jiffies + HZ * flow->max_idle;
+ }
+
+ if (flow_timeout(flow)) {
+ if (dp->flags & OFPC_SEND_FLOW_EXP) {
+ /* xxx Get byte count */
+ flow->byte_count = 0;
+ dp_send_flow_expired(dp, flow);
+ }
+ del_count += do_delete(swt, flow);
+ }
+ if ((i % 50) == 0) {
+ msleep_interruptible(1);
+ }
+ i++;
+ }
+
+ /* Remove any entries queued for removal */
+ spin_lock_bh(&pending_free_lock);
+ list_for_each_entry_safe (sfw, n, &pending_free_list, node) {
+ list_del(&sfw->node);
+ table_dummy_sfw_destroy(sfw);
+ }
+ spin_unlock_bh(&pending_free_lock);
+
+ if (del_count)
+ atomic_sub(del_count, &td->n_flows);
+ return del_count;
+}
+
+
+static void table_dummy_destroy(struct sw_table *swt)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *)swt;
+
+
+ /* xxx This table is being destroyed, so free any data that you
+ * xxx don't want to leak.
+ */
+
+
+ if (td) {
+ while (!list_empty(&td->flows)) {
+ struct sw_flow *flow = list_entry(td->flows.next,
+ struct sw_flow, node);
+ list_del(&flow->node);
+ flow_free(flow);
+ }
+ kfree(td);
+ }
+}
+
+static int table_dummy_iterate(struct sw_table *swt,
+ const struct sw_flow_key *key,
+ struct sw_table_position *position,
+ int (*callback)(struct sw_flow *, void *),
+ void *private)
+{
+ struct sw_table_dummy *tl = (struct sw_table_dummy *) swt;
+ struct sw_flow *flow;
+ unsigned long start;
+
+ start = ~position->private[0];
+ list_for_each_entry_rcu (flow, &tl->iter_flows, iter_node) {
+ if (flow->serial <= start && flow_matches(key, &flow->key)) {
+ int error = callback(flow, private);
+ if (error) {
+ position->private[0] = ~flow->serial;
+ return error;
+ }
+ }
+ }
+ return 0;
+}
+
+static void table_dummy_stats(struct sw_table *swt,
+ struct sw_table_stats *stats)
+{
+ struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
+ stats->name = "dummy";
+ stats->n_flows = atomic_read(&td->n_flows);
+ stats->max_flows = td->max_flows;
+}
+
+
+static struct sw_table *table_dummy_create(void)
+{
+ struct sw_table_dummy *td;
+ struct sw_table *swt;
+
+ td = kzalloc(sizeof *td, GFP_KERNEL);
+ if (td == NULL)
+ return NULL;
+
+ swt = &td->swt;
+ swt->lookup = table_dummy_lookup;
+ swt->insert = table_dummy_insert;
+ swt->delete = table_dummy_delete;
+ swt->timeout = table_dummy_timeout;
+ swt->destroy = table_dummy_destroy;
+ swt->iterate = table_dummy_iterate;
+ swt->stats = table_dummy_stats;
+
+ td->max_flows = DUMMY_MAX_FLOW;
+ atomic_set(&td->n_flows, 0);
+ INIT_LIST_HEAD(&td->flows);
+ spin_lock_init(&td->lock);
+
+ INIT_LIST_HEAD(&pending_free_list);
+ spin_lock_init(&pending_free_lock);
+
+ return swt;
+}
+
+static int __init dummy_init(void)
+{
+ return chain_set_hw_hook(table_dummy_create, THIS_MODULE);
+}
+module_init(dummy_init);
+
+static void dummy_cleanup(void)
+{
+ chain_clear_hw_hook();
+}
+module_exit(dummy_cleanup);
+
+MODULE_DESCRIPTION("Dummy hardware table driver");
+MODULE_AUTHOR("Copyright (c) 2007, 2008 The Board of Trustees of The Leland Stanford Junior University");
+MODULE_LICENSE("GPL");
include $(srcdir)/../Modules.mk
include $(srcdir)/Modules.mk
+include @HW_TABLES@
default:
distclean: clean
include $(srcdir)/../Modules.mk
include $(srcdir)/Modules.mk
+include @HW_TABLES@
EXTRA_CFLAGS := -DVERSION=\"$(VERSION)\"
EXTRA_CFLAGS += -I$(srcdir)/..
include $(srcdir)/../Modules.mk
include $(srcdir)/Modules.mk
+include @HW_TABLES@
default: $(all_sources)
$(all_sources):
#include <linux/module.h>
EXPORT_SYMBOL(flow_alloc);
-EXPORT_SYMBOL(flow_free);
EXPORT_SYMBOL(flow_cache);
EXPORT_SYMBOL(table_hash_create);
projects / openvswitch / commitdiff