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linux/drivers/net/xen-netback/xenbus.c
Kees Cook fad953ce0b treewide: Use array_size() in vzalloc() 
The vzalloc() function has no 2-factor argument form, so multiplication
factors need to be wrapped in array_size(). This patch replaces cases of:

        vzalloc(a * b)

with:
        vzalloc(array_size(a, b))

as well as handling cases of:

        vzalloc(a * b * c)

with:

        vzalloc(array3_size(a, b, c))

This does, however, attempt to ignore constant size factors like:

        vzalloc(4 * 1024)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  vzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  vzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  vzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  vzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
  vzalloc(
-	sizeof(TYPE) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * COUNT_ID
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(THING) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * COUNT_ID
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

  vzalloc(
-	SIZE * COUNT
+	array_size(COUNT, SIZE)
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  vzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  vzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  vzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  vzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  vzalloc(C1 * C2 * C3, ...)
|
  vzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants.
@@
expression E1, E2;
constant C1, C2;
@@

(
  vzalloc(C1 * C2, ...)
|
  vzalloc(
-	E1 * E2
+	array_size(E1, E2)
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00

1217 lines
30 KiB
C
Raw Blame History

/*
* Xenbus code for netif backend
*
* Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
* Copyright (C) 2005 XenSource Ltd
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "common.h"
#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
struct backend_info {
struct xenbus_device *dev;
struct xenvif *vif;
/* This is the state that will be reflected in xenstore when any
* active hotplug script completes.
*/
enum xenbus_state state;
enum xenbus_state frontend_state;
struct xenbus_watch hotplug_status_watch;
u8 have_hotplug_status_watch:1;
const char *hotplug_script;
};
static int connect_data_rings(struct backend_info *be,
struct xenvif_queue *queue);
static void connect(struct backend_info *be);
static int read_xenbus_vif_flags(struct backend_info *be);
static int backend_create_xenvif(struct backend_info *be);
static void unregister_hotplug_status_watch(struct backend_info *be);
static void xen_unregister_watchers(struct xenvif *vif);
static void set_backend_state(struct backend_info *be,
enum xenbus_state state);
#ifdef CONFIG_DEBUG_FS
struct dentry *xen_netback_dbg_root = NULL;
static int xenvif_read_io_ring(struct seq_file *m, void *v)
{
struct xenvif_queue *queue = m->private;
struct xen_netif_tx_back_ring *tx_ring = &queue->tx;
struct xen_netif_rx_back_ring *rx_ring = &queue->rx;
struct netdev_queue *dev_queue;
if (tx_ring->sring) {
struct xen_netif_tx_sring *sring = tx_ring->sring;
seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id,
tx_ring->nr_ents);
seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
sring->req_prod,
sring->req_prod - sring->rsp_prod,
tx_ring->req_cons,
tx_ring->req_cons - sring->rsp_prod,
sring->req_event,
sring->req_event - sring->rsp_prod);
seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n",
sring->rsp_prod,
tx_ring->rsp_prod_pvt,
tx_ring->rsp_prod_pvt - sring->rsp_prod,
sring->rsp_event,
sring->rsp_event - sring->rsp_prod);
seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n",
queue->pending_prod,
queue->pending_cons,
nr_pending_reqs(queue));
seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n",
queue->dealloc_prod,
queue->dealloc_cons,
queue->dealloc_prod - queue->dealloc_cons);
}
if (rx_ring->sring) {
struct xen_netif_rx_sring *sring = rx_ring->sring;
seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents);
seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
sring->req_prod,
sring->req_prod - sring->rsp_prod,
rx_ring->req_cons,
rx_ring->req_cons - sring->rsp_prod,
sring->req_event,
sring->req_event - sring->rsp_prod);
seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n",
sring->rsp_prod,
rx_ring->rsp_prod_pvt,
rx_ring->rsp_prod_pvt - sring->rsp_prod,
sring->rsp_event,
sring->rsp_event - sring->rsp_prod);
}
seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n"
"Credit timer_pending: %d, credit: %lu, usec: %lu\n"
"remaining: %lu, expires: %lu, now: %lu\n",
queue->napi.state, queue->napi.weight,
skb_queue_len(&queue->tx_queue),
timer_pending(&queue->credit_timeout),
queue->credit_bytes,
queue->credit_usec,
queue->remaining_credit,
queue->credit_timeout.expires,
jiffies);
dev_queue = netdev_get_tx_queue(queue->vif->dev, queue->id);
seq_printf(m, "\nRx internal queue: len %u max %u pkts %u %s\n",
queue->rx_queue_len, queue->rx_queue_max,
skb_queue_len(&queue->rx_queue),
netif_tx_queue_stopped(dev_queue) ? "stopped" : "running");
return 0;
}
#define XENVIF_KICK_STR "kick"
#define BUFFER_SIZE 32
static ssize_t
xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
loff_t *ppos)
{
struct xenvif_queue *queue =
((struct seq_file *)filp->private_data)->private;
int len;
char write[BUFFER_SIZE];
/* don't allow partial writes and check the length */
if (*ppos != 0)
return 0;
if (count >= sizeof(write))
return -ENOSPC;
len = simple_write_to_buffer(write,
sizeof(write) - 1,
ppos,
buf,
count);
if (len < 0)
return len;
write[len] = '\0';
if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1))
xenvif_interrupt(0, (void *)queue);
else {
pr_warn("Unknown command to io_ring_q%d. Available: kick\n",
queue->id);
count = -EINVAL;
}
return count;
}
static int xenvif_io_ring_open(struct inode *inode, struct file *filp)
{
int ret;
void *queue = NULL;
if (inode->i_private)
queue = inode->i_private;
ret = single_open(filp, xenvif_read_io_ring, queue);
filp->f_mode |= FMODE_PWRITE;
return ret;
}
static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
.owner = THIS_MODULE,
.open = xenvif_io_ring_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = xenvif_write_io_ring,
};
static int xenvif_read_ctrl(struct seq_file *m, void *v)
{
struct xenvif *vif = m->private;
xenvif_dump_hash_info(vif, m);
return 0;
}
static int xenvif_ctrl_open(struct inode *inode, struct file *filp)
{
return single_open(filp, xenvif_read_ctrl, inode->i_private);
}
static const struct file_operations xenvif_dbg_ctrl_ops_fops = {
.owner = THIS_MODULE,
.open = xenvif_ctrl_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void xenvif_debugfs_addif(struct xenvif *vif)
{
struct dentry *pfile;
int i;
if (IS_ERR_OR_NULL(xen_netback_dbg_root))
return;
vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
xen_netback_dbg_root);
if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
for (i = 0; i < vif->num_queues; ++i) {
char filename[sizeof("io_ring_q") + 4];
snprintf(filename, sizeof(filename), "io_ring_q%d", i);
pfile = debugfs_create_file(filename,
0600,
vif->xenvif_dbg_root,
&vif->queues[i],
&xenvif_dbg_io_ring_ops_fops);
if (IS_ERR_OR_NULL(pfile))
pr_warn("Creation of io_ring file returned %ld!\n",
PTR_ERR(pfile));
}
if (vif->ctrl_irq) {
pfile = debugfs_create_file("ctrl",
0400,
vif->xenvif_dbg_root,
vif,
&xenvif_dbg_ctrl_ops_fops);
if (IS_ERR_OR_NULL(pfile))
pr_warn("Creation of ctrl file returned %ld!\n",
PTR_ERR(pfile));
}
} else
netdev_warn(vif->dev,
"Creation of vif debugfs dir returned %ld!\n",
PTR_ERR(vif->xenvif_dbg_root));
}
static void xenvif_debugfs_delif(struct xenvif *vif)
{
if (IS_ERR_OR_NULL(xen_netback_dbg_root))
return;
if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
debugfs_remove_recursive(vif->xenvif_dbg_root);
vif->xenvif_dbg_root = NULL;
}
#endif /* CONFIG_DEBUG_FS */
static int netback_remove(struct xenbus_device *dev)
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
set_backend_state(be, XenbusStateClosed);
unregister_hotplug_status_watch(be);
if (be->vif) {
kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
xen_unregister_watchers(be->vif);
xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
xenvif_free(be->vif);
be->vif = NULL;
}
kfree(be->hotplug_script);
kfree(be);
dev_set_drvdata(&dev->dev, NULL);
return 0;
}
/**
* Entry point to this code when a new device is created. Allocate the basic
* structures and switch to InitWait.
*/
static int netback_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
const char *message;
struct xenbus_transaction xbt;
int err;
int sg;
const char *script;
struct backend_info *be = kzalloc(sizeof(struct backend_info),
GFP_KERNEL);
if (!be) {
xenbus_dev_fatal(dev, -ENOMEM,
"allocating backend structure");
return -ENOMEM;
}
be->dev = dev;
dev_set_drvdata(&dev->dev, be);
be->state = XenbusStateInitialising;
err = xenbus_switch_state(dev, XenbusStateInitialising);
if (err)
goto fail;
sg = 1;
do {
err = xenbus_transaction_start(&xbt);
if (err) {
xenbus_dev_fatal(dev, err, "starting transaction");
goto fail;
}
err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
if (err) {
message = "writing feature-sg";
goto abort_transaction;
}
err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
"%d", sg);
if (err) {
message = "writing feature-gso-tcpv4";
goto abort_transaction;
}
err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
"%d", sg);
if (err) {
message = "writing feature-gso-tcpv6";
goto abort_transaction;
}
/* We support partial checksum setup for IPv6 packets */
err = xenbus_printf(xbt, dev->nodename,
"feature-ipv6-csum-offload",
"%d", 1);
if (err) {
message = "writing feature-ipv6-csum-offload";
goto abort_transaction;
}
/* We support rx-copy path. */
err = xenbus_printf(xbt, dev->nodename,
"feature-rx-copy", "%d", 1);
if (err) {
message = "writing feature-rx-copy";
goto abort_transaction;
}
/*
* We don't support rx-flip path (except old guests who don't
* grok this feature flag).
*/
err = xenbus_printf(xbt, dev->nodename,
"feature-rx-flip", "%d", 0);
if (err) {
message = "writing feature-rx-flip";
goto abort_transaction;
}
/* We support dynamic multicast-control. */
err = xenbus_printf(xbt, dev->nodename,
"feature-multicast-control", "%d", 1);
if (err) {
message = "writing feature-multicast-control";
goto abort_transaction;
}
err = xenbus_printf(xbt, dev->nodename,
"feature-dynamic-multicast-control",
"%d", 1);
if (err) {
message = "writing feature-dynamic-multicast-control";
goto abort_transaction;
}
err = xenbus_transaction_end(xbt, 0);
} while (err == -EAGAIN);
if (err) {
xenbus_dev_fatal(dev, err, "completing transaction");
goto fail;
}
/*
* Split event channels support, this is optional so it is not
* put inside the above loop.
*/
err = xenbus_printf(XBT_NIL, dev->nodename,
"feature-split-event-channels",
"%u", separate_tx_rx_irq);
if (err)
pr_debug("Error writing feature-split-event-channels\n");
/* Multi-queue support: This is an optional feature. */
err = xenbus_printf(XBT_NIL, dev->nodename,
"multi-queue-max-queues", "%u", xenvif_max_queues);
if (err)
pr_debug("Error writing multi-queue-max-queues\n");
err = xenbus_printf(XBT_NIL, dev->nodename,
"feature-ctrl-ring",
"%u", true);
if (err)
pr_debug("Error writing feature-ctrl-ring\n");
script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
if (IS_ERR(script)) {
err = PTR_ERR(script);
xenbus_dev_fatal(dev, err, "reading script");
goto fail;
}
be->hotplug_script = script;
/* This kicks hotplug scripts, so do it immediately. */
err = backend_create_xenvif(be);
if (err)
goto fail;
return 0;
abort_transaction:
xenbus_transaction_end(xbt, 1);
xenbus_dev_fatal(dev, err, "%s", message);
fail:
pr_debug("failed\n");
netback_remove(dev);
return err;
}
/*
* Handle the creation of the hotplug script environment. We add the script
* and vif variables to the environment, for the benefit of the vif-* hotplug
* scripts.
*/
static int netback_uevent(struct xenbus_device *xdev,
struct kobj_uevent_env *env)
{
struct backend_info *be = dev_get_drvdata(&xdev->dev);
if (!be)
return 0;
if (add_uevent_var(env, "script=%s", be->hotplug_script))
return -ENOMEM;
if (!be->vif)
return 0;
return add_uevent_var(env, "vif=%s", be->vif->dev->name);
}
static int backend_create_xenvif(struct backend_info *be)
{
int err;
long handle;
struct xenbus_device *dev = be->dev;
struct xenvif *vif;
if (be->vif != NULL)
return 0;
err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
if (err != 1) {
xenbus_dev_fatal(dev, err, "reading handle");
return (err < 0) ? err : -EINVAL;
}
vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
if (IS_ERR(vif)) {
err = PTR_ERR(vif);
xenbus_dev_fatal(dev, err, "creating interface");
return err;
}
be->vif = vif;
kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
return 0;
}
static void backend_disconnect(struct backend_info *be)
{
struct xenvif *vif = be->vif;
if (vif) {
unsigned int num_queues = vif->num_queues;
unsigned int queue_index;
xen_unregister_watchers(vif);
#ifdef CONFIG_DEBUG_FS
xenvif_debugfs_delif(vif);
#endif /* CONFIG_DEBUG_FS */
xenvif_disconnect_data(vif);
/* At this point some of the handlers may still be active
* so we need to have additional synchronization here.
*/
vif->num_queues = 0;
synchronize_net();
for (queue_index = 0; queue_index < num_queues; ++queue_index)
xenvif_deinit_queue(&vif->queues[queue_index]);
vfree(vif->queues);
vif->queues = NULL;
xenvif_disconnect_ctrl(vif);
}
}
static void backend_connect(struct backend_info *be)
{
if (be->vif)
connect(be);
}
static inline void backend_switch_state(struct backend_info *be,
enum xenbus_state state)
{
struct xenbus_device *dev = be->dev;
pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
be->state = state;
/* If we are waiting for a hotplug script then defer the
* actual xenbus state change.
*/
if (!be->have_hotplug_status_watch)
xenbus_switch_state(dev, state);
}
/* Handle backend state transitions:
*
* The backend state starts in Initialising and the following transitions are
* allowed.
*
* Initialising -> InitWait -> Connected
* \
* \ ^ \ |
* \ | \ |
* \ | \ |
* \ | \ |
* \ | \ |
* \ | \ |
* V | V V
*
* Closed <-> Closing
*
* The state argument specifies the eventual state of the backend and the
* function transitions to that state via the shortest path.
*/
static void set_backend_state(struct backend_info *be,
enum xenbus_state state)
{
while (be->state != state) {
switch (be->state) {
case XenbusStateInitialising:
switch (state) {
case XenbusStateInitWait:
case XenbusStateConnected:
case XenbusStateClosing:
backend_switch_state(be, XenbusStateInitWait);
break;
case XenbusStateClosed:
backend_switch_state(be, XenbusStateClosed);
break;
default:
BUG();
}
break;
case XenbusStateClosed:
switch (state) {
case XenbusStateInitWait:
case XenbusStateConnected:
backend_switch_state(be, XenbusStateInitWait);
break;
case XenbusStateClosing:
backend_switch_state(be, XenbusStateClosing);
break;
default:
BUG();
}
break;
case XenbusStateInitWait:
switch (state) {
case XenbusStateConnected:
backend_connect(be);
backend_switch_state(be, XenbusStateConnected);
break;
case XenbusStateClosing:
case XenbusStateClosed:
backend_switch_state(be, XenbusStateClosing);
break;
default:
BUG();
}
break;
case XenbusStateConnected:
switch (state) {
case XenbusStateInitWait:
case XenbusStateClosing:
case XenbusStateClosed:
backend_disconnect(be);
backend_switch_state(be, XenbusStateClosing);
break;
default:
BUG();
}
break;
case XenbusStateClosing:
switch (state) {
case XenbusStateInitWait:
case XenbusStateConnected:
case XenbusStateClosed:
backend_switch_state(be, XenbusStateClosed);
break;
default:
BUG();
}
break;
default:
BUG();
}
}
}
/**
* Callback received when the frontend's state changes.
*/
static void frontend_changed(struct xenbus_device *dev,
enum xenbus_state frontend_state)
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
be->frontend_state = frontend_state;
switch (frontend_state) {
case XenbusStateInitialising:
set_backend_state(be, XenbusStateInitWait);
break;
case XenbusStateInitialised:
break;
case XenbusStateConnected:
set_backend_state(be, XenbusStateConnected);
break;
case XenbusStateClosing:
set_backend_state(be, XenbusStateClosing);
break;
case XenbusStateClosed:
set_backend_state(be, XenbusStateClosed);
if (xenbus_dev_is_online(dev))
break;
/* fall through if not online */
case XenbusStateUnknown:
set_backend_state(be, XenbusStateClosed);
device_unregister(&dev->dev);
break;
default:
xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
frontend_state);
break;
}
}
static void xen_net_read_rate(struct xenbus_device *dev,
unsigned long *bytes, unsigned long *usec)
{
char *s, *e;
unsigned long b, u;
char *ratestr;
/* Default to unlimited bandwidth. */
*bytes = ~0UL;
*usec = 0;
ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
if (IS_ERR(ratestr))
return;
s = ratestr;
b = simple_strtoul(s, &e, 10);
if ((s == e) || (*e != ','))
goto fail;
s = e + 1;
u = simple_strtoul(s, &e, 10);
if ((s == e) || (*e != '\0'))
goto fail;
*bytes = b;
*usec = u;
kfree(ratestr);
return;
fail:
pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
kfree(ratestr);
}
static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
{
char *s, *e, *macstr;
int i;
macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
if (IS_ERR(macstr))
return PTR_ERR(macstr);
for (i = 0; i < ETH_ALEN; i++) {
mac[i] = simple_strtoul(s, &e, 16);
if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
kfree(macstr);
return -ENOENT;
}
s = e+1;
}
kfree(macstr);
return 0;
}
static void xen_net_rate_changed(struct xenbus_watch *watch,
const char *path, const char *token)
{
struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
unsigned long credit_bytes;
unsigned long credit_usec;
unsigned int queue_index;
xen_net_read_rate(dev, &credit_bytes, &credit_usec);
for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {
struct xenvif_queue *queue = &vif->queues[queue_index];
queue->credit_bytes = credit_bytes;
queue->credit_usec = credit_usec;
if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&
queue->remaining_credit > queue->credit_bytes) {
queue->remaining_credit = queue->credit_bytes;
}
}
}
static int xen_register_credit_watch(struct xenbus_device *dev,
struct xenvif *vif)
{
int err = 0;
char *node;
unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");
if (vif->credit_watch.node)
return -EADDRINUSE;
node = kmalloc(maxlen, GFP_KERNEL);
if (!node)
return -ENOMEM;
snprintf(node, maxlen, "%s/rate", dev->nodename);
vif->credit_watch.node = node;
vif->credit_watch.callback = xen_net_rate_changed;
err = register_xenbus_watch(&vif->credit_watch);
if (err) {
pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
kfree(node);
vif->credit_watch.node = NULL;
vif->credit_watch.callback = NULL;
}
return err;
}
static void xen_unregister_credit_watch(struct xenvif *vif)
{
if (vif->credit_watch.node) {
unregister_xenbus_watch(&vif->credit_watch);
kfree(vif->credit_watch.node);
vif->credit_watch.node = NULL;
}
}
static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
const char *path, const char *token)
{
struct xenvif *vif = container_of(watch, struct xenvif,
mcast_ctrl_watch);
struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
vif->multicast_control = !!xenbus_read_unsigned(dev->otherend,
"request-multicast-control", 0);
}
static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
struct xenvif *vif)
{
int err = 0;
char *node;
unsigned maxlen = strlen(dev->otherend) +
sizeof("/request-multicast-control");
if (vif->mcast_ctrl_watch.node) {
pr_err_ratelimited("Watch is already registered\n");
return -EADDRINUSE;
}
node = kmalloc(maxlen, GFP_KERNEL);
if (!node) {
pr_err("Failed to allocate memory for watch\n");
return -ENOMEM;
}
snprintf(node, maxlen, "%s/request-multicast-control",
dev->otherend);
vif->mcast_ctrl_watch.node = node;
vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed;
err = register_xenbus_watch(&vif->mcast_ctrl_watch);
if (err) {
pr_err("Failed to set watcher %s\n",
vif->mcast_ctrl_watch.node);
kfree(node);
vif->mcast_ctrl_watch.node = NULL;
vif->mcast_ctrl_watch.callback = NULL;
}
return err;
}
static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif)
{
if (vif->mcast_ctrl_watch.node) {
unregister_xenbus_watch(&vif->mcast_ctrl_watch);
kfree(vif->mcast_ctrl_watch.node);
vif->mcast_ctrl_watch.node = NULL;
}
}
static void xen_register_watchers(struct xenbus_device *dev,
struct xenvif *vif)
{
xen_register_credit_watch(dev, vif);
xen_register_mcast_ctrl_watch(dev, vif);
}
static void xen_unregister_watchers(struct xenvif *vif)
{
xen_unregister_mcast_ctrl_watch(vif);
xen_unregister_credit_watch(vif);
}
static void unregister_hotplug_status_watch(struct backend_info *be)
{
if (be->have_hotplug_status_watch) {
unregister_xenbus_watch(&be->hotplug_status_watch);
kfree(be->hotplug_status_watch.node);
}
be->have_hotplug_status_watch = 0;
}
static void hotplug_status_changed(struct xenbus_watch *watch,
const char *path,
const char *token)
{
struct backend_info *be = container_of(watch,
struct backend_info,
hotplug_status_watch);
char *str;
unsigned int len;
str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
if (IS_ERR(str))
return;
if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
/* Complete any pending state change */
xenbus_switch_state(be->dev, be->state);
/* Not interested in this watch anymore. */
unregister_hotplug_status_watch(be);
}
kfree(str);
}
static int connect_ctrl_ring(struct backend_info *be)
{
struct xenbus_device *dev = be->dev;
struct xenvif *vif = be->vif;
unsigned int val;
grant_ref_t ring_ref;
unsigned int evtchn;
int err;
err = xenbus_scanf(XBT_NIL, dev->otherend,
"ctrl-ring-ref", "%u", &val);
if (err < 0)
goto done; /* The frontend does not have a control ring */
ring_ref = val;
err = xenbus_scanf(XBT_NIL, dev->otherend,
"event-channel-ctrl", "%u", &val);
if (err < 0) {
xenbus_dev_fatal(dev, err,
"reading %s/event-channel-ctrl",
dev->otherend);
goto fail;
}
evtchn = val;
err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
if (err) {
xenbus_dev_fatal(dev, err,
"mapping shared-frame %u port %u",
ring_ref, evtchn);
goto fail;
}
done:
return 0;
fail:
return err;
}
static void connect(struct backend_info *be)
{
int err;
struct xenbus_device *dev = be->dev;
unsigned long credit_bytes, credit_usec;
unsigned int queue_index;
unsigned int requested_num_queues;
struct xenvif_queue *queue;
/* Check whether the frontend requested multiple queues
* and read the number requested.
*/
requested_num_queues = xenbus_read_unsigned(dev->otherend,
"multi-queue-num-queues", 1);
if (requested_num_queues > xenvif_max_queues) {
/* buggy or malicious guest */
xenbus_dev_fatal(dev, -EINVAL,
"guest requested %u queues, exceeding the maximum of %u.",
requested_num_queues, xenvif_max_queues);
return;
}
err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
if (err) {
xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
return;
}
xen_net_read_rate(dev, &credit_bytes, &credit_usec);
xen_unregister_watchers(be->vif);
xen_register_watchers(dev, be->vif);
read_xenbus_vif_flags(be);
err = connect_ctrl_ring(be);
if (err) {
xenbus_dev_fatal(dev, err, "connecting control ring");
return;
}
/* Use the number of queues requested by the frontend */
be->vif->queues = vzalloc(array_size(requested_num_queues,
sizeof(struct xenvif_queue)));
if (!be->vif->queues) {
xenbus_dev_fatal(dev, -ENOMEM,
"allocating queues");
return;
}
be->vif->num_queues = requested_num_queues;
be->vif->stalled_queues = requested_num_queues;
for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
queue = &be->vif->queues[queue_index];
queue->vif = be->vif;
queue->id = queue_index;
snprintf(queue->name, sizeof(queue->name), "%s-q%u",
be->vif->dev->name, queue->id);
err = xenvif_init_queue(queue);
if (err) {
/* xenvif_init_queue() cleans up after itself on
* failure, but we need to clean up any previously
* initialised queues. Set num_queues to i so that
* earlier queues can be destroyed using the regular
* disconnect logic.
*/
be->vif->num_queues = queue_index;
goto err;
}
queue->credit_bytes = credit_bytes;
queue->remaining_credit = credit_bytes;
queue->credit_usec = credit_usec;
err = connect_data_rings(be, queue);
if (err) {
/* connect_data_rings() cleans up after itself on
* failure, but we need to clean up after
* xenvif_init_queue() here, and also clean up any
* previously initialised queues.
*/
xenvif_deinit_queue(queue);
be->vif->num_queues = queue_index;
goto err;
}
}
#ifdef CONFIG_DEBUG_FS
xenvif_debugfs_addif(be->vif);
#endif /* CONFIG_DEBUG_FS */
/* Initialisation completed, tell core driver the number of
* active queues.
*/
rtnl_lock();
netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
rtnl_unlock();
xenvif_carrier_on(be->vif);
unregister_hotplug_status_watch(be);
err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
hotplug_status_changed,
"%s/%s", dev->nodename, "hotplug-status");
if (!err)
be->have_hotplug_status_watch = 1;
netif_tx_wake_all_queues(be->vif->dev);
return;
err:
if (be->vif->num_queues > 0)
xenvif_disconnect_data(be->vif); /* Clean up existing queues */
for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index)
xenvif_deinit_queue(&be->vif->queues[queue_index]);
vfree(be->vif->queues);
be->vif->queues = NULL;
be->vif->num_queues = 0;
xenvif_disconnect_ctrl(be->vif);
return;
}
static int connect_data_rings(struct backend_info *be,
struct xenvif_queue *queue)
{
struct xenbus_device *dev = be->dev;
unsigned int num_queues = queue->vif->num_queues;
unsigned long tx_ring_ref, rx_ring_ref;
unsigned int tx_evtchn, rx_evtchn;
int err;
char *xspath;
size_t xspathsize;
const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
/* If the frontend requested 1 queue, or we have fallen back
* to single queue due to lack of frontend support for multi-
* queue, expect the remaining XenStore keys in the toplevel
* directory. Otherwise, expect them in a subdirectory called
* queue-N.
*/
if (num_queues == 1) {
xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
if (!xspath) {
xenbus_dev_fatal(dev, -ENOMEM,
"reading ring references");
return -ENOMEM;
}
strcpy(xspath, dev->otherend);
} else {
xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
xspath = kzalloc(xspathsize, GFP_KERNEL);
if (!xspath) {
xenbus_dev_fatal(dev, -ENOMEM,
"reading ring references");
return -ENOMEM;
}
snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
queue->id);
}
err = xenbus_gather(XBT_NIL, xspath,
"tx-ring-ref", "%lu", &tx_ring_ref,
"rx-ring-ref", "%lu", &rx_ring_ref, NULL);
if (err) {
xenbus_dev_fatal(dev, err,
"reading %s/ring-ref",
xspath);
goto err;
}
/* Try split event channels first, then single event channel. */
err = xenbus_gather(XBT_NIL, xspath,
"event-channel-tx", "%u", &tx_evtchn,
"event-channel-rx", "%u", &rx_evtchn, NULL);
if (err < 0) {
err = xenbus_scanf(XBT_NIL, xspath,
"event-channel", "%u", &tx_evtchn);
if (err < 0) {
xenbus_dev_fatal(dev, err,
"reading %s/event-channel(-tx/rx)",
xspath);
goto err;
}
rx_evtchn = tx_evtchn;
}
/* Map the shared frame, irq etc. */
err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
tx_evtchn, rx_evtchn);
if (err) {
xenbus_dev_fatal(dev, err,
"mapping shared-frames %lu/%lu port tx %u rx %u",
tx_ring_ref, rx_ring_ref,
tx_evtchn, rx_evtchn);
goto err;
}
err = 0;
err: /* Regular return falls through with err == 0 */
kfree(xspath);
return err;
}
static int read_xenbus_vif_flags(struct backend_info *be)
{
struct xenvif *vif = be->vif;
struct xenbus_device *dev = be->dev;
unsigned int rx_copy;
int err;
err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
&rx_copy);
if (err == -ENOENT) {
err = 0;
rx_copy = 0;
}
if (err < 0) {
xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
dev->otherend);
return err;
}
if (!rx_copy)
return -EOPNOTSUPP;
if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) {
/* - Reduce drain timeout to poll more frequently for
* Rx requests.
* - Disable Rx stall detection.
*/
be->vif->drain_timeout = msecs_to_jiffies(30);
be->vif->stall_timeout = 0;
}
vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0);
vif->gso_mask = 0;
if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0))
vif->gso_mask |= GSO_BIT(TCPV4);
if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0))
vif->gso_mask |= GSO_BIT(TCPV6);
vif->ip_csum = !xenbus_read_unsigned(dev->otherend,
"feature-no-csum-offload", 0);
vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
"feature-ipv6-csum-offload", 0);
return 0;
}
static const struct xenbus_device_id netback_ids[] = {
{ "vif" },
{ "" }
};
static struct xenbus_driver netback_driver = {
.ids = netback_ids,
.probe = netback_probe,
.remove = netback_remove,
.uevent = netback_uevent,
.otherend_changed = frontend_changed,
};
int xenvif_xenbus_init(void)
{
return xenbus_register_backend(&netback_driver);
}
void xenvif_xenbus_fini(void)
{
return xenbus_unregister_driver(&netback_driver);
}
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