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openflow/switch/datapath.c
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/* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
* Junior University
*
* We are making the OpenFlow specification and associated documentation
* (Software) available for public use and benefit with the expectation
* that others will use, modify and enhance the Software and contribute
* those enhancements back to the community. However, since we would
* like to make the Software available for broadest use, with as few
* restrictions as possible permission is hereby granted, free of
* charge, to any person obtaining a copy of this Software to deal in
* the Software under the copyrights without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* The name and trademarks of copyright holder(s) may NOT be used in
* advertising or publicity pertaining to the Software or any
* derivatives without specific, written prior permission.
*/
#include "datapath.h"
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "buffer.h"
#include "chain.h"
#include "flow.h"
#include "netdev.h"
#include "packets.h"
#include "poll-loop.h"
#include "rconn.h"
#include "vconn.h"
#include "table.h"
#include "xtoxll.h"
#define THIS_MODULE VLM_datapath
#include "vlog.h"
#define BRIDGE_PORT_NO_FLOOD 0x00000001
/* Capabilities supported by this implementation. */
#define OFP_SUPPORTED_CAPABILITIES (OFPC_MULTI_PHY_TX)
/* Actions supported by this implementation. */
#define OFP_SUPPORTED_ACTIONS ( (1 << OFPAT_OUTPUT) \
| (1 << OFPAT_SET_DL_VLAN) \
| (1 << OFPAT_SET_DL_SRC) \
| (1 << OFPAT_SET_DL_DST) \
| (1 << OFPAT_SET_NW_SRC) \
| (1 << OFPAT_SET_NW_DST) \
| (1 << OFPAT_SET_TP_SRC) \
| (1 << OFPAT_SET_TP_DST) )
struct sw_port {
uint32_t flags;
struct datapath *dp;
struct netdev *netdev;
struct list node; /* Element in datapath.ports. */
unsigned long long int rx_count, tx_count, drop_count;
};
/* A connection to a controller or a management device. */
struct remote {
struct list node;
struct rconn *rconn;
};
/* The origin of a received OpenFlow message, to enable sending a reply. */
struct sender {
struct remote *remote; /* The device that sent the message. */
uint32_t xid; /* The OpenFlow transaction ID. */
};
struct datapath {
/* Remote connections. */
struct remote *controller; /* Connection to controller. */
struct list remotes; /* All connections (including controller). */
struct vconn *listen_vconn;
time_t last_timeout;
/* Unique identifier for this datapath */
uint64_t id;
struct sw_chain *chain; /* Forwarding rules. */
struct ofp_switch_config config;
/* Switch ports. */
struct sw_port ports[OFPP_MAX];
struct list port_list; /* List of ports, for flooding. */
};
static struct remote *remote_create(struct datapath *, struct rconn *);
static void remote_run(struct datapath *, struct remote *);
static void remote_wait(struct remote *);
static void remote_destroy(struct remote *);
void dp_output_port(struct datapath *, struct buffer *,
int in_port, int out_port);
void dp_update_port_flags(struct datapath *dp, const struct ofp_phy_port *opp);
void dp_output_control(struct datapath *, struct buffer *, int in_port,
size_t max_len, int reason);
static void send_flow_expired(struct datapath *, struct sw_flow *);
static void send_port_status(struct sw_port *p, uint8_t status);
static void del_switch_port(struct sw_port *p);
static void execute_actions(struct datapath *, struct buffer *,
int in_port, const struct sw_flow_key *,
const struct ofp_action *, int n_actions);
static void modify_vlan(struct buffer *buffer, const struct sw_flow_key *key,
const struct ofp_action *a);
static void modify_nh(struct buffer *buffer, uint16_t eth_proto,
uint8_t nw_proto, const struct ofp_action *a);
static void modify_th(struct buffer *buffer, uint16_t eth_proto,
uint8_t nw_proto, const struct ofp_action *a);
/* Buffers are identified to userspace by a 31-bit opaque ID. We divide the ID
* into a buffer number (low bits) and a cookie (high bits). The buffer number
* is an index into an array of buffers. The cookie distinguishes between
* different packets that have occupied a single buffer. Thus, the more
* buffers we have, the lower-quality the cookie... */
#define PKT_BUFFER_BITS 8
#define N_PKT_BUFFERS (1 << PKT_BUFFER_BITS)
#define PKT_BUFFER_MASK (N_PKT_BUFFERS - 1)
#define PKT_COOKIE_BITS (32 - PKT_BUFFER_BITS)
void fwd_port_input(struct datapath *, struct buffer *, int in_port);
int fwd_control_input(struct datapath *, const struct sender *,
const void *, size_t);
uint32_t save_buffer(struct buffer *);
static struct buffer *retrieve_buffer(uint32_t id);
static void discard_buffer(uint32_t id);
static int port_no(struct datapath *dp, struct sw_port *p)
{
assert(p >= dp->ports && p < &dp->ports[ARRAY_SIZE(dp->ports)]);
return p - dp->ports;
}
/* Generates a unique datapath id. It incorporates the datapath index
* and a hardware address, if available. If not, it generates a random
* one.
*/
static uint64_t
gen_datapath_id(void)
{
/* Choose a random datapath id. */
uint64_t id = 0;
int i;
srand(time(0));
for (i = 0; i < ETH_ADDR_LEN; i++) {
id |= (uint64_t)(rand() & 0xff) << (8*(ETH_ADDR_LEN-1 - i));
}
return id;
}
int
dp_new(struct datapath **dp_, uint64_t dpid, struct rconn *rconn)
{
struct datapath *dp;
dp = calloc(1, sizeof *dp);
if (!dp) {
return ENOMEM;
}
dp->last_timeout = time(0);
list_init(&dp->remotes);
dp->controller = remote_create(dp, rconn);
dp->listen_vconn = NULL;
dp->id = dpid <= UINT64_C(0xffffffffffff) ? dpid : gen_datapath_id();
dp->chain = chain_create();
if (!dp->chain) {
VLOG_ERR("could not create chain");
free(dp);
return ENOMEM;
}
list_init(&dp->port_list);
dp->config.flags = 0;
dp->config.miss_send_len = htons(OFP_DEFAULT_MISS_SEND_LEN);
*dp_ = dp;
return 0;
}
int
dp_add_port(struct datapath *dp, const char *name)
{
struct netdev *netdev;
struct sw_port *p;
int error;
error = netdev_open(name, &netdev);
if (error) {
return error;
}
for (p = dp->ports; ; p++) {
if (p >= &dp->ports[ARRAY_SIZE(dp->ports)]) {
return EXFULL;
} else if (!p->netdev) {
break;
}
}
p->dp = dp;
p->netdev = netdev;
p->tx_count = 0;
p->rx_count = 0;
p->drop_count = 0;
list_push_back(&dp->port_list, &p->node);
/* Notify the ctlpath that this port has been added */
send_port_status(p, OFPPR_ADD);
return 0;
}
void
dp_add_listen_vconn(struct datapath *dp, struct vconn *listen_vconn)
{
assert(!dp->listen_vconn);
dp->listen_vconn = listen_vconn;
}
void
dp_run(struct datapath *dp)
{
time_t now = time(0);
struct sw_port *p, *pn;
struct remote *r, *rn;
struct buffer *buffer = NULL;
if (now != dp->last_timeout) {
struct list deleted = LIST_INITIALIZER(&deleted);
struct sw_flow *f, *n;
chain_timeout(dp->chain, &deleted);
LIST_FOR_EACH_SAFE (f, n, struct sw_flow, node, &deleted) {
send_flow_expired(dp, f);
list_remove(&f->node);
flow_free(f);
}
dp->last_timeout = now;
}
poll_timer_wait(1000);
LIST_FOR_EACH_SAFE (p, pn, struct sw_port, node, &dp->port_list) {
int error;
if (!buffer) {
/* Allocate buffer with some headroom to add headers in forwarding
* to the controller or adding a vlan tag, plus an extra 2 bytes to
* allow IP headers to be aligned on a 4-byte boundary. */
const int headroom = 128 + 2;
const int hard_header = VLAN_ETH_HEADER_LEN;
const int mtu = netdev_get_mtu(p->netdev);
buffer = buffer_new(headroom + hard_header + mtu);
buffer->data += headroom;
}
error = netdev_recv(p->netdev, buffer);
if (!error) {
p->rx_count++;
fwd_port_input(dp, buffer, port_no(dp, p));
buffer = NULL;
} else if (error != EAGAIN) {
VLOG_ERR("Error receiving data from %s: %s",
netdev_get_name(p->netdev), strerror(error));
del_switch_port(p);
}
}
buffer_delete(buffer);
/* Talk to remotes. */
LIST_FOR_EACH_SAFE (r, rn, struct remote, node, &dp->remotes) {
remote_run(dp, r);
}
if (dp->listen_vconn) {
for (;;) {
struct vconn *new_vconn;
int retval;
retval = vconn_accept(dp->listen_vconn, &new_vconn);
if (retval) {
if (retval != EAGAIN) {
VLOG_WARN("accept failed (%s)", strerror(retval));
}
break;
}
remote_create(dp, rconn_new_from_vconn("passive", 128, new_vconn));
}
}
}
static void
remote_run(struct datapath *dp, struct remote *r)
{
int i;
rconn_run(r->rconn);
/* Process a number of commands from the remote, but cap them at a
* reasonable number so that other processing doesn't starve. */
for (i = 0; i < 50; i++) {
struct buffer *buffer;
struct ofp_header *oh;
buffer = rconn_recv(r->rconn);
if (!buffer) {
break;
}
if (buffer->size >= sizeof *oh) {
struct sender sender;
oh = buffer->data;
sender.remote = r;
sender.xid = oh->xid;
fwd_control_input(dp, &sender, buffer->data, buffer->size);
} else {
VLOG_WARN("received too-short OpenFlow message");
}
buffer_delete(buffer);
}
if (!rconn_is_alive(r->rconn)) {
remote_destroy(r);
}
}
static void
remote_wait(struct remote *r)
{
rconn_run_wait(r->rconn);
rconn_recv_wait(r->rconn);
}
static void
remote_destroy(struct remote *r)
{
if (r) {
list_remove(&r->node);
rconn_destroy(r->rconn);
free(r);
}
}
static struct remote *
remote_create(struct datapath *dp, struct rconn *rconn)
{
struct remote *remote = xmalloc(sizeof *remote);
list_push_back(&dp->remotes, &remote->node);
remote->rconn = rconn;
return remote;
}
void
dp_wait(struct datapath *dp)
{
struct sw_port *p;
struct remote *r;
LIST_FOR_EACH (p, struct sw_port, node, &dp->port_list) {
netdev_recv_wait(p->netdev);
}
LIST_FOR_EACH (r, struct remote, node, &dp->remotes) {
remote_wait(r);
}
if (dp->listen_vconn) {
vconn_accept_wait(dp->listen_vconn);
}
}
/* Delete 'p' from switch. */
static void
del_switch_port(struct sw_port *p)
{
send_port_status(p, OFPPR_DELETE);
netdev_close(p->netdev);
p->netdev = NULL;
list_remove(&p->node);
}
void
dp_destroy(struct datapath *dp)
{
struct sw_port *p, *n;
if (!dp) {
return;
}
LIST_FOR_EACH_SAFE (p, n, struct sw_port, node, &dp->port_list) {
del_switch_port(p);
}
chain_destroy(dp->chain);
free(dp);
}
static int
flood(struct datapath *dp, struct buffer *buffer, int in_port)
{
struct sw_port *p;
int prev_port;
prev_port = -1;
LIST_FOR_EACH (p, struct sw_port, node, &dp->port_list) {
if (port_no(dp, p) == in_port || p->flags & BRIDGE_PORT_NO_FLOOD) {
continue;
}
if (prev_port != -1) {
dp_output_port(dp, buffer_clone(buffer), in_port, prev_port);
}
prev_port = port_no(dp, p);
}
if (prev_port != -1)
dp_output_port(dp, buffer, in_port, prev_port);
else
buffer_delete(buffer);
return 0;
}
void
output_packet(struct datapath *dp, struct buffer *buffer, int out_port)
{
if (out_port >= 0 && out_port < OFPP_MAX) {
struct sw_port *p = &dp->ports[out_port];
if (p->netdev != NULL) {
if (!netdev_send(p->netdev, buffer)) {
p->tx_count++;
} else {
p->drop_count++;
}
return;
}
}
buffer_delete(buffer);
/* FIXME: ratelimit */
VLOG_DBG("can't forward to bad port %d\n", out_port);
}
/* Takes ownership of 'buffer' and transmits it to 'out_port' on 'dp'.
*/
void
dp_output_port(struct datapath *dp, struct buffer *buffer,
int in_port, int out_port)
{
assert(buffer);
if (out_port == OFPP_FLOOD) {
flood(dp, buffer, in_port);
} else if (out_port == OFPP_CONTROLLER) {
dp_output_control(dp, buffer, in_port, 0, OFPR_ACTION);
} else if (out_port == OFPP_TABLE) {
struct sw_flow_key key;
struct sw_flow *flow;
key.wildcards = 0;
flow_extract(buffer, in_port, &key.flow);
flow = chain_lookup(dp->chain, &key);
if (flow != NULL) {
flow_used(flow, buffer);
execute_actions(dp, buffer, in_port, &key,
flow->actions, flow->n_actions);
}
} else {
output_packet(dp, buffer, out_port);
}
}
static void *
alloc_openflow_buffer(struct datapath *dp, size_t openflow_len, uint8_t type,
const struct sender *sender, struct buffer **bufferp)
{
struct buffer *buffer;
struct ofp_header *oh;
buffer = *bufferp = buffer_new(openflow_len);
oh = buffer_put_uninit(buffer, openflow_len);
oh->version = OFP_VERSION;
oh->type = type;
oh->length = 0; /* Filled in by send_openflow_buffer(). */
oh->xid = sender ? sender->xid : 0;
return oh;
}
static int
send_openflow_buffer(struct datapath *dp, struct buffer *buffer,
const struct sender *sender)
{
struct remote *remote = sender ? sender->remote : dp->controller;
struct rconn *rconn = remote->rconn;
struct ofp_header *oh;
int retval;
oh = buffer_at_assert(buffer, 0, sizeof *oh);
oh->length = htons(buffer->size);
retval = rconn_send(rconn, buffer);
if (retval) {
VLOG_WARN("send to %s failed: %s",
rconn_get_name(rconn), strerror(retval));
buffer_delete(buffer);
}
return retval;
}
/* Takes ownership of 'buffer' and transmits it to 'dp''s controller. If the
* packet can be saved in a buffer, then only the first max_len bytes of
* 'buffer' are sent; otherwise, all of 'buffer' is sent. 'reason' indicates
* why 'buffer' is being sent. 'max_len' sets the maximum number of bytes that
* the caller wants to be sent; a value of 0 indicates the entire packet should
* be sent. */
void
dp_output_control(struct datapath *dp, struct buffer *buffer, int in_port,
size_t max_len, int reason)
{
struct ofp_packet_in *opi;
size_t total_len;
uint32_t buffer_id;
buffer_id = save_buffer(buffer);
total_len = buffer->size;
if (buffer_id != UINT32_MAX && buffer->size > max_len) {
buffer->size = max_len;
}
opi = buffer_push_uninit(buffer, offsetof(struct ofp_packet_in, data));
opi->header.version = OFP_VERSION;
opi->header.type = OFPT_PACKET_IN;
opi->header.length = htons(buffer->size);
opi->header.xid = htonl(0);
opi->buffer_id = htonl(buffer_id);
opi->total_len = htons(total_len);
opi->in_port = htons(in_port);
opi->reason = reason;
opi->pad = 0;
send_openflow_buffer(dp, buffer, NULL);
}
static void fill_port_desc(struct datapath *dp, struct sw_port *p,
struct ofp_phy_port *desc)
{
desc->port_no = htons(port_no(dp, p));
strncpy((char *) desc->name, netdev_get_name(p->netdev),
sizeof desc->name);
desc->name[sizeof desc->name - 1] = '\0';
memcpy(desc->hw_addr, netdev_get_etheraddr(p->netdev), ETH_ADDR_LEN);
desc->flags = htonl(p->flags);
desc->features = htonl(netdev_get_features(p->netdev));
desc->speed = htonl(netdev_get_speed(p->netdev));
}
static void
dp_send_features_reply(struct datapath *dp, const struct sender *sender)
{
struct buffer *buffer;
struct ofp_switch_features *ofr;
struct sw_port *p;
ofr = alloc_openflow_buffer(dp, sizeof *ofr, OFPT_FEATURES_REPLY,
sender, &buffer);
ofr->datapath_id = htonll(dp->id);
ofr->n_exact = htonl(2 * TABLE_HASH_MAX_FLOWS);
ofr->n_compression = 0; /* Not supported */
ofr->n_general = htonl(TABLE_LINEAR_MAX_FLOWS);
ofr->buffer_mb = htonl(UINT32_MAX);
ofr->n_buffers = htonl(N_PKT_BUFFERS);
ofr->capabilities = htonl(OFP_SUPPORTED_CAPABILITIES);
ofr->actions = htonl(OFP_SUPPORTED_ACTIONS);
LIST_FOR_EACH (p, struct sw_port, node, &dp->port_list) {
struct ofp_phy_port *opp = buffer_put_uninit(buffer, sizeof *opp);
memset(opp, 0, sizeof *opp);
fill_port_desc(dp, p, opp);
}
send_openflow_buffer(dp, buffer, sender);
}
void
dp_update_port_flags(struct datapath *dp, const struct ofp_phy_port *opp)
{
struct sw_port *p;
p = &dp->ports[htons(opp->port_no)];
/* Make sure the port id hasn't changed since this was sent */
if (!p || memcmp(opp->hw_addr, netdev_get_etheraddr(p->netdev),
ETH_ADDR_LEN) != 0)
return;
p->flags = htonl(opp->flags);
}
static void
send_port_status(struct sw_port *p, uint8_t status)
{
struct buffer *buffer;
struct ofp_port_status *ops;
ops = alloc_openflow_buffer(p->dp, sizeof *ops, OFPT_PORT_STATUS, NULL,
&buffer);
ops->reason = status;
fill_port_desc(p->dp, p, &ops->desc);
send_openflow_buffer(p->dp, buffer, NULL);
}
void
send_flow_expired(struct datapath *dp, struct sw_flow *flow)
{
struct buffer *buffer;
struct ofp_flow_expired *ofe;
ofe = alloc_openflow_buffer(dp, sizeof *ofe, OFPT_FLOW_EXPIRED, NULL,
&buffer);
flow_fill_match(&ofe->match, &flow->key);
ofe->duration = htonl(flow->timeout - flow->max_idle - flow->created);
ofe->packet_count = htonll(flow->packet_count);
ofe->byte_count = htonll(flow->byte_count);
send_openflow_buffer(dp, buffer, NULL);
}
void
dp_send_error_msg(struct datapath *dp, const struct sender *sender,
uint16_t type, uint16_t code, const uint8_t *data, size_t len)
{
struct buffer *buffer;
struct ofp_error_msg *oem;
oem = alloc_openflow_buffer(dp, sizeof(*oem)+len, OFPT_ERROR_MSG,
sender, &buffer);
oem->type = htons(type);
oem->code = htons(code);
memcpy(oem->data, data, len);
send_openflow_buffer(dp, buffer, sender);
}
static void
fill_flow_stats(struct ofp_flow_stats *ofs, struct sw_flow *flow,
int table_idx, time_t now)
{
ofs->match.wildcards = htons(flow->key.wildcards);
ofs->match.in_port = flow->key.flow.in_port;
memcpy(ofs->match.dl_src, flow->key.flow.dl_src, ETH_ADDR_LEN);
memcpy(ofs->match.dl_dst, flow->key.flow.dl_dst, ETH_ADDR_LEN);
ofs->match.dl_vlan = flow->key.flow.dl_vlan;
ofs->match.dl_type = flow->key.flow.dl_type;
ofs->match.nw_src = flow->key.flow.nw_src;
ofs->match.nw_dst = flow->key.flow.nw_dst;
ofs->match.nw_proto = flow->key.flow.nw_proto;
memset(ofs->match.pad, 0, sizeof ofs->match.pad);
ofs->match.tp_src = flow->key.flow.tp_src;
ofs->match.tp_dst = flow->key.flow.tp_dst;
ofs->duration = htonl(now - flow->created);
ofs->priority = htons(flow->priority);
ofs->table_id = table_idx;
ofs->packet_count = htonll(flow->packet_count);
ofs->byte_count = htonll(flow->byte_count);
}
int
dp_send_flow_stats(struct datapath *dp, const struct sender *sender,
const struct ofp_match *match)
{
struct buffer *buffer;
struct ofp_flow_stats_reply *fsr;
size_t header_size, fudge, flow_size;
struct sw_flow_key match_key;
int table_idx, n_flows, max_flows;
time_t now;
header_size = offsetof(struct ofp_flow_stats_reply, flows);
fudge = 128;
flow_size = sizeof fsr->flows[0];
max_flows = (65536 - header_size - fudge) / flow_size;
fsr = alloc_openflow_buffer(dp, header_size,
OFPT_FLOW_STATS_REPLY, sender, &buffer);
n_flows = 0;
flow_extract_match(&match_key, match);
now = time(0);
for (table_idx = 0; table_idx < dp->chain->n_tables; table_idx++) {
struct sw_table *table = dp->chain->tables[table_idx];
struct swt_iterator iter;
if (n_flows >= max_flows) {
break;
}
if (!table->iterator(table, &iter)) {
printf("iterator failed for table %d\n", table_idx);
continue;
}
for (; iter.flow; table->iterator_next(&iter)) {
if (flow_matches(&match_key, &iter.flow->key)) {
struct ofp_flow_stats *ofs = buffer_put_uninit(buffer,
sizeof *ofs);
fill_flow_stats(ofs, iter.flow, table_idx, now);
if (++n_flows >= max_flows) {
break;
}
}
}
table->iterator_destroy(&iter);
}
return send_openflow_buffer(dp, buffer, sender);
}
int
dp_send_port_stats(struct datapath *dp, const struct sender *sender)
{
struct buffer *buffer;
struct ofp_port_stats_reply *psr;
struct sw_port *p;
psr = alloc_openflow_buffer(dp, offsetof(struct ofp_port_stats_reply,
ports),
OFPT_PORT_STATS_REPLY, sender, &buffer);
LIST_FOR_EACH (p, struct sw_port, node, &dp->port_list) {
struct ofp_port_stats *ps = buffer_put_uninit(buffer, sizeof *ps);
ps->port_no = htons(port_no(dp, p));
memset(ps->pad, 0, sizeof ps->pad);
ps->rx_count = htonll(p->rx_count);
ps->tx_count = htonll(p->tx_count);
ps->drop_count = htonll(p->drop_count);
}
return send_openflow_buffer(dp, buffer, sender);
}
int
dp_send_table_stats(struct datapath *dp, const struct sender *sender)
{
struct buffer *buffer;
struct ofp_table_stats_reply *tsr;
int i;
tsr = alloc_openflow_buffer(dp, offsetof(struct ofp_table_stats_reply,
tables),
OFPT_TABLE_STATS_REPLY, sender, &buffer);
for (i = 0; i < dp->chain->n_tables; i++) {
struct ofp_table_stats *ots = buffer_put_uninit(buffer, sizeof *ots);
struct sw_table_stats stats;
dp->chain->tables[i]->stats(dp->chain->tables[i], &stats);
strncpy(ots->name, stats.name, sizeof ots->name);
ots->table_id = i;
ots->pad[0] = ots->pad[1] = 0;
ots->max_entries = htonl(stats.max_flows);
ots->active_count = htonl(stats.n_flows);
ots->matched_count = htonll(0); /* FIXME */
}
return send_openflow_buffer(dp, buffer, sender);
}
/* 'buffer' was received on 'in_port', a physical switch port between 0 and
* OFPP_MAX. Process it according to 'chain'. */
void fwd_port_input(struct datapath *dp, struct buffer *buffer, int in_port)
{
struct sw_flow_key key;
struct sw_flow *flow;
key.wildcards = 0;
flow_extract(buffer, in_port, &key.flow);
flow = chain_lookup(dp->chain, &key);
if (flow != NULL) {
flow_used(flow, buffer);
execute_actions(dp, buffer, in_port, &key,
flow->actions, flow->n_actions);
} else {
dp_output_control(dp, buffer, in_port, ntohs(dp->config.miss_send_len),
OFPR_NO_MATCH);
}
}
static void
do_output(struct datapath *dp, struct buffer *buffer, int in_port,
size_t max_len, int out_port)
{
if (out_port != OFPP_CONTROLLER) {
dp_output_port(dp, buffer, in_port, out_port);
} else {
dp_output_control(dp, buffer, in_port, max_len, OFPR_ACTION);
}
}
static void
execute_actions(struct datapath *dp, struct buffer *buffer,
int in_port, const struct sw_flow_key *key,
const struct ofp_action *actions, int n_actions)
{
/* Every output action needs a separate clone of 'buffer', but the common
* case is just a single output action, so that doing a clone and then
* freeing the original buffer is wasteful. So the following code is
* slightly obscure just to avoid that. */
int prev_port;
size_t max_len=0; /* Initialze to make compiler happy */
uint16_t eth_proto;
int i;
prev_port = -1;
eth_proto = ntohs(key->flow.dl_type);
for (i = 0; i < n_actions; i++) {
const struct ofp_action *a = &actions[i];
struct eth_header *eh = buffer->l2;
if (prev_port != -1) {
do_output(dp, buffer_clone(buffer), in_port, max_len, prev_port);
prev_port = -1;
}
switch (ntohs(a->type)) {
case OFPAT_OUTPUT:
prev_port = ntohs(a->arg.output.port);
max_len = ntohs(a->arg.output.max_len);
break;
case OFPAT_SET_DL_VLAN:
modify_vlan(buffer, key, a);
break;
case OFPAT_SET_DL_SRC:
memcpy(eh->eth_src, a->arg.dl_addr, sizeof eh->eth_src);
break;
case OFPAT_SET_DL_DST:
memcpy(eh->eth_dst, a->arg.dl_addr, sizeof eh->eth_dst);
break;
case OFPAT_SET_NW_SRC:
case OFPAT_SET_NW_DST:
modify_nh(buffer, eth_proto, key->flow.nw_proto, a);
break;
case OFPAT_SET_TP_SRC:
case OFPAT_SET_TP_DST:
modify_th(buffer, eth_proto, key->flow.nw_proto, a);
break;
default:
NOT_REACHED();
}
}
if (prev_port != -1)
do_output(dp, buffer, in_port, max_len, prev_port);
else
buffer_delete(buffer);
}
/* Returns the new checksum for a packet in which the checksum field previously
* contained 'old_csum' and in which a field that contained 'old_u16' was
* changed to contain 'new_u16'. */
static uint16_t
recalc_csum16(uint16_t old_csum, uint16_t old_u16, uint16_t new_u16)
{
/* Ones-complement arithmetic is endian-independent, so this code does not
* use htons() or ntohs().
*
* See RFC 1624 for formula and explanation. */
uint16_t hc_complement = ~old_csum;
uint16_t m_complement = ~old_u16;
uint16_t m_prime = new_u16;
uint32_t sum = hc_complement + m_complement + m_prime;
uint16_t hc_prime_complement = sum + (sum >> 16);
return ~hc_prime_complement;
}
/* Returns the new checksum for a packet in which the checksum field previously
* contained 'old_csum' and in which a field that contained 'old_u32' was
* changed to contain 'new_u32'. */
static uint16_t
recalc_csum32(uint16_t old_csum, uint32_t old_u32, uint32_t new_u32)
{
return recalc_csum16(recalc_csum16(old_csum, old_u32, new_u32),
old_u32 >> 16, new_u32 >> 16);
}
static void modify_nh(struct buffer *buffer, uint16_t eth_proto,
uint8_t nw_proto, const struct ofp_action *a)
{
if (eth_proto == ETH_TYPE_IP) {
struct ip_header *nh = buffer->l3;
uint32_t new, *field;
new = a->arg.nw_addr;
field = a->type == OFPAT_SET_NW_SRC ? &nh->ip_src : &nh->ip_dst;
if (nw_proto == IP_TYPE_TCP) {
struct tcp_header *th = buffer->l4;
th->tcp_csum = recalc_csum32(th->tcp_csum, *field, new);
} else if (nw_proto == IP_TYPE_UDP) {
struct udp_header *th = buffer->l4;
if (th->udp_csum) {
th->udp_csum = recalc_csum32(th->udp_csum, *field, new);
if (!th->udp_csum) {
th->udp_csum = 0xffff;
}
}
}
nh->ip_csum = recalc_csum32(nh->ip_csum, *field, new);
*field = new;
}
}
static void modify_th(struct buffer *buffer, uint16_t eth_proto,
uint8_t nw_proto, const struct ofp_action *a)
{
if (eth_proto == ETH_TYPE_IP) {
uint16_t new, *field;
new = a->arg.tp;
if (nw_proto == IP_TYPE_TCP) {
struct tcp_header *th = buffer->l4;
field = a->type == OFPAT_SET_TP_SRC ? &th->tcp_src : &th->tcp_dst;
th->tcp_csum = recalc_csum16(th->tcp_csum, *field, new);
*field = new;
} else if (nw_proto == IP_TYPE_UDP) {
struct udp_header *th = buffer->l4;
field = a->type == OFPAT_SET_TP_SRC ? &th->udp_src : &th->udp_dst;
th->udp_csum = recalc_csum16(th->udp_csum, *field, new);
*field = new;
}
}
}
static void
modify_vlan(struct buffer *buffer,
const struct sw_flow_key *key, const struct ofp_action *a)
{
uint16_t new_id = a->arg.vlan_id;
struct vlan_eth_header *veh;
if (new_id != OFP_VLAN_NONE) {
if (key->flow.dl_vlan != htons(OFP_VLAN_NONE)) {
/* Modify vlan id, but maintain other TCI values */
veh = buffer->l2;
veh->veth_tci &= ~htons(VLAN_VID);
veh->veth_tci |= htons(new_id);
} else {
/* Insert new vlan id. */
struct eth_header *eh = buffer->l2;
struct vlan_eth_header tmp;
memcpy(tmp.veth_dst, eh->eth_dst, ETH_ADDR_LEN);
memcpy(tmp.veth_src, eh->eth_src, ETH_ADDR_LEN);
tmp.veth_type = htons(ETH_TYPE_VLAN);
tmp.veth_tci = new_id;
tmp.veth_next_type = eh->eth_type;
veh = buffer_push_uninit(buffer, VLAN_HEADER_LEN);
memcpy(veh, &tmp, sizeof tmp);
buffer->l2 -= VLAN_HEADER_LEN;
}
} else {
/* Remove an existing vlan header if it exists */
veh = buffer->l2;
if (veh->veth_type == htons(ETH_TYPE_VLAN)) {
struct eth_header tmp;
memcpy(tmp.eth_dst, veh->veth_dst, ETH_ADDR_LEN);
memcpy(tmp.eth_src, veh->veth_src, ETH_ADDR_LEN);
tmp.eth_type = veh->veth_next_type;
buffer->size -= VLAN_HEADER_LEN;
buffer->data += VLAN_HEADER_LEN;
buffer->l2 += VLAN_HEADER_LEN;
memcpy(buffer->data, &tmp, sizeof tmp);
}
}
}
static int
recv_features_request(struct datapath *dp, const struct sender *sender,
const void *msg)
{
dp_send_features_reply(dp, sender);
return 0;
}
static int
recv_get_config_request(struct datapath *dp, const struct sender *sender,
const void *msg)
{
struct buffer *buffer;
struct ofp_switch_config *osc;
osc = alloc_openflow_buffer(dp, sizeof *osc, OFPT_GET_CONFIG_REPLY,
sender, &buffer);
assert(sizeof *osc == sizeof dp->config);
memcpy(((char *)osc) + sizeof osc->header,
((char *)&dp->config) + sizeof dp->config.header,
sizeof dp->config - sizeof dp->config.header);
return send_openflow_buffer(dp, buffer, sender);
}
static int
recv_set_config(struct datapath *dp, const struct sender *sender UNUSED,
const void *msg)
{
const struct ofp_switch_config *osc = msg;
dp->config = *osc;
return 0;
}
static int
recv_packet_out(struct datapath *dp, const struct sender *sender UNUSED,
const void *msg)
{
const struct ofp_packet_out *opo = msg;
if (ntohl(opo->buffer_id) == (uint32_t) -1) {
/* FIXME: can we avoid copying data here? */
int data_len = ntohs(opo->header.length) - sizeof *opo;
struct buffer *buffer = buffer_new(data_len);
buffer_put(buffer, opo->u.data, data_len);
dp_output_port(dp, buffer,
ntohs(opo->in_port), ntohs(opo->out_port));
} else {
struct sw_flow_key key;
struct buffer *buffer;
int n_acts;
buffer = retrieve_buffer(ntohl(opo->buffer_id));
if (!buffer) {
return -ESRCH;
}
n_acts = (ntohs(opo->header.length) - sizeof *opo)
/ sizeof *opo->u.actions;
flow_extract(buffer, ntohs(opo->in_port), &key.flow);
execute_actions(dp, buffer, ntohs(opo->in_port),
&key, opo->u.actions, n_acts);
}
return 0;
}
static int
recv_port_mod(struct datapath *dp, const struct sender *sender UNUSED,
const void *msg)
{
const struct ofp_port_mod *opm = msg;
dp_update_port_flags(dp, &opm->desc);
return 0;
}
static int
add_flow(struct datapath *dp, const struct ofp_flow_mod *ofm)
{
int error = -ENOMEM;
int n_acts;
int i;
struct sw_flow *flow;
/* Check number of actions. */
n_acts = (ntohs(ofm->header.length) - sizeof *ofm) / sizeof *ofm->actions;
if (n_acts > MAX_ACTIONS) {
error = -E2BIG;
goto error;
}
/* To prevent loops, make sure there's no action to send to the
* OFP_TABLE virtual port.
*/
for (i=0; i<n_acts; i++) {
const struct ofp_action *a = &ofm->actions[i];
if (a->type == htons(OFPAT_OUTPUT)
&& a->arg.output.port == htons(OFPP_TABLE)) {
/* xxx Send fancy new error message? */
goto error;
}
}
/* Allocate memory. */
flow = flow_alloc(n_acts);
if (flow == NULL)
goto error;
/* Fill out flow. */
flow_extract_match(&flow->key, &ofm->match);
flow->max_idle = ntohs(ofm->max_idle);
flow->priority = ntohs(ofm->priority);
flow->timeout = time(0) + flow->max_idle; /* FIXME */
flow->n_actions = n_acts;
flow->created = time(0); /* FIXME */
flow->byte_count = 0;
flow->packet_count = 0;
memcpy(flow->actions, ofm->actions, n_acts * sizeof *flow->actions);
/* Act. */
error = chain_insert(dp->chain, flow);
if (error) {
goto error_free_flow;
}
error = 0;
if (ntohl(ofm->buffer_id) != UINT32_MAX) {
struct buffer *buffer = retrieve_buffer(ntohl(ofm->buffer_id));
if (buffer) {
struct sw_flow_key key;
uint16_t in_port = ntohs(ofm->match.in_port);
flow_used(flow, buffer);
flow_extract(buffer, in_port, &key.flow);
execute_actions(dp, buffer, in_port, &key, ofm->actions, n_acts);
} else {
error = -ESRCH;
}
}
return error;
error_free_flow:
flow_free(flow);
error:
if (ntohl(ofm->buffer_id) != (uint32_t) -1)
discard_buffer(ntohl(ofm->buffer_id));
return error;
}
static int
recv_flow(struct datapath *dp, const struct sender *sender UNUSED,
const void *msg)
{
const struct ofp_flow_mod *ofm = msg;
uint16_t command = ntohs(ofm->command);
if (command == OFPFC_ADD) {
return add_flow(dp, ofm);
} else if (command == OFPFC_DELETE) {
struct sw_flow_key key;
flow_extract_match(&key, &ofm->match);
return chain_delete(dp->chain, &key, 0, 0) ? 0 : -ESRCH;
} else if (command == OFPFC_DELETE_STRICT) {
struct sw_flow_key key;
flow_extract_match(&key, &ofm->match);
return chain_delete(dp->chain, &key,
ntohs(ofm->priority), 1) ? 0 : -ESRCH;
} else {
return -ENODEV;
}
}
static int
recv_flow_stats_request(struct datapath *dp, const struct sender *sender,
const void *msg)
{
const struct ofp_flow_stats_request *fsr = msg;
if (fsr->type == OFPFS_INDIV) {
return dp_send_flow_stats(dp, sender, &fsr->match);
} else {
/* FIXME */
return -ENOSYS;
}
}
static int
recv_port_stats_request(struct datapath *dp, const struct sender *sender,
const void *msg)
{
return dp_send_port_stats(dp, sender);
}
static int
recv_table_stats_request(struct datapath *dp, const struct sender *sender,
const void *msg)
{
return dp_send_table_stats(dp, sender);
}
/* 'msg', which is 'length' bytes long, was received from the control path.
* Apply it to 'chain'. */
int
fwd_control_input(struct datapath *dp, const struct sender *sender,
const void *msg, size_t length)
{
struct openflow_packet {
size_t min_size;
int (*handler)(struct datapath *, const struct sender *, const void *);
};
static const struct openflow_packet packets[] = {
[OFPT_FEATURES_REQUEST] = {
sizeof (struct ofp_header),
recv_features_request,
},
[OFPT_GET_CONFIG_REQUEST] = {
sizeof (struct ofp_header),
recv_get_config_request,
},
[OFPT_SET_CONFIG] = {
sizeof (struct ofp_switch_config),
recv_set_config,
},
[OFPT_PACKET_OUT] = {
sizeof (struct ofp_packet_out),
recv_packet_out,
},
[OFPT_FLOW_MOD] = {
sizeof (struct ofp_flow_mod),
recv_flow,
},
[OFPT_PORT_MOD] = {
sizeof (struct ofp_port_mod),
recv_port_mod,
},
[OFPT_FLOW_STATS_REQUEST] = {
sizeof (struct ofp_flow_stats_request),
recv_flow_stats_request,
},
[OFPT_PORT_STATS_REQUEST] = {
sizeof (struct ofp_port_stats_request),
recv_port_stats_request,
},
[OFPT_TABLE_STATS_REQUEST] = {
sizeof (struct ofp_table_stats_request),
recv_table_stats_request,
},
};
const struct openflow_packet *pkt;
struct ofp_header *oh;
oh = (struct ofp_header *) msg;
if (oh->version != OFP_VERSION || oh->type >= ARRAY_SIZE(packets)
|| ntohs(oh->length) > length)
return -EINVAL;
pkt = &packets[oh->type];
if (!pkt->handler)
return -ENOSYS;
if (length < pkt->min_size)
return -EFAULT;
return pkt->handler(dp, sender, msg);
}
/* Packet buffering. */
#define OVERWRITE_SECS 1
struct packet_buffer {
struct buffer *buffer;
uint32_t cookie;
time_t timeout;
};
static struct packet_buffer buffers[N_PKT_BUFFERS];
static unsigned int buffer_idx;
uint32_t save_buffer(struct buffer *buffer)
{
struct packet_buffer *p;
uint32_t id;
buffer_idx = (buffer_idx + 1) & PKT_BUFFER_MASK;
p = &buffers[buffer_idx];
if (p->buffer) {
/* Don't buffer packet if existing entry is less than
* OVERWRITE_SECS old. */
if (time(0) < p->timeout) { /* FIXME */
return -1;
} else {
buffer_delete(p->buffer);
}
}
/* Don't use maximum cookie value since the all-bits-1 id is
* special. */
if (++p->cookie >= (1u << PKT_COOKIE_BITS) - 1)
p->cookie = 0;
p->buffer = buffer_clone(buffer); /* FIXME */
p->timeout = time(0) + OVERWRITE_SECS; /* FIXME */
id = buffer_idx | (p->cookie << PKT_BUFFER_BITS);
return id;
}
static struct buffer *retrieve_buffer(uint32_t id)
{
struct buffer *buffer = NULL;
struct packet_buffer *p;
p = &buffers[id & PKT_BUFFER_MASK];
if (p->cookie == id >> PKT_BUFFER_BITS) {
buffer = p->buffer;
p->buffer = NULL;
} else {
printf("cookie mismatch: %x != %x\n",
id >> PKT_BUFFER_BITS, p->cookie);
}
return buffer;
}
static void discard_buffer(uint32_t id)
{
struct packet_buffer *p;
p = &buffers[id & PKT_BUFFER_MASK];
if (p->cookie == id >> PKT_BUFFER_BITS) {
buffer_delete(p->buffer);
p->buffer = NULL;
}
}
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