linux/net/ipv4/udp_tunnel_nic.c
Jakub Kicinski 74cc6d182d udp_tunnel: add the ability to share port tables
Unfortunately recent Intel NIC designs share the UDP port table
across netdevs. So far the UDP tunnel port state was maintained
per netdev, we need to extend that to cater to Intel NICs.

Expect NICs to allocate the info structure dynamically and link
to the state from there. All the shared NICs will record port
offload information in the one instance of the table so we need
to make sure that the use count can accommodate larger numbers.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-28 12:50:12 -07:00

974 lines
24 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2020 Facebook Inc.
#include <linux/ethtool_netlink.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <net/udp_tunnel.h>
#include <net/vxlan.h>
enum udp_tunnel_nic_table_entry_flags {
UDP_TUNNEL_NIC_ENTRY_ADD = BIT(0),
UDP_TUNNEL_NIC_ENTRY_DEL = BIT(1),
UDP_TUNNEL_NIC_ENTRY_OP_FAIL = BIT(2),
UDP_TUNNEL_NIC_ENTRY_FROZEN = BIT(3),
};
struct udp_tunnel_nic_table_entry {
__be16 port;
u8 type;
u8 flags;
u16 use_cnt;
#define UDP_TUNNEL_NIC_USE_CNT_MAX U16_MAX
u8 hw_priv;
};
/**
* struct udp_tunnel_nic - UDP tunnel port offload state
* @work: async work for talking to hardware from process context
* @dev: netdev pointer
* @need_sync: at least one port start changed
* @need_replay: space was freed, we need a replay of all ports
* @work_pending: @work is currently scheduled
* @n_tables: number of tables under @entries
* @missed: bitmap of tables which overflown
* @entries: table of tables of ports currently offloaded
*/
struct udp_tunnel_nic {
struct work_struct work;
struct net_device *dev;
u8 need_sync:1;
u8 need_replay:1;
u8 work_pending:1;
unsigned int n_tables;
unsigned long missed;
struct udp_tunnel_nic_table_entry **entries;
};
/* We ensure all work structs are done using driver state, but not the code.
* We need a workqueue we can flush before module gets removed.
*/
static struct workqueue_struct *udp_tunnel_nic_workqueue;
static const char *udp_tunnel_nic_tunnel_type_name(unsigned int type)
{
switch (type) {
case UDP_TUNNEL_TYPE_VXLAN:
return "vxlan";
case UDP_TUNNEL_TYPE_GENEVE:
return "geneve";
case UDP_TUNNEL_TYPE_VXLAN_GPE:
return "vxlan-gpe";
default:
return "unknown";
}
}
static bool
udp_tunnel_nic_entry_is_free(struct udp_tunnel_nic_table_entry *entry)
{
return entry->use_cnt == 0 && !entry->flags;
}
static bool
udp_tunnel_nic_entry_is_present(struct udp_tunnel_nic_table_entry *entry)
{
return entry->use_cnt && !(entry->flags & ~UDP_TUNNEL_NIC_ENTRY_FROZEN);
}
static bool
udp_tunnel_nic_entry_is_frozen(struct udp_tunnel_nic_table_entry *entry)
{
return entry->flags & UDP_TUNNEL_NIC_ENTRY_FROZEN;
}
static void
udp_tunnel_nic_entry_freeze_used(struct udp_tunnel_nic_table_entry *entry)
{
if (!udp_tunnel_nic_entry_is_free(entry))
entry->flags |= UDP_TUNNEL_NIC_ENTRY_FROZEN;
}
static void
udp_tunnel_nic_entry_unfreeze(struct udp_tunnel_nic_table_entry *entry)
{
entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_FROZEN;
}
static bool
udp_tunnel_nic_entry_is_queued(struct udp_tunnel_nic_table_entry *entry)
{
return entry->flags & (UDP_TUNNEL_NIC_ENTRY_ADD |
UDP_TUNNEL_NIC_ENTRY_DEL);
}
static void
udp_tunnel_nic_entry_queue(struct udp_tunnel_nic *utn,
struct udp_tunnel_nic_table_entry *entry,
unsigned int flag)
{
entry->flags |= flag;
utn->need_sync = 1;
}
static void
udp_tunnel_nic_ti_from_entry(struct udp_tunnel_nic_table_entry *entry,
struct udp_tunnel_info *ti)
{
memset(ti, 0, sizeof(*ti));
ti->port = entry->port;
ti->type = entry->type;
ti->hw_priv = entry->hw_priv;
}
static bool
udp_tunnel_nic_is_empty(struct net_device *dev, struct udp_tunnel_nic *utn)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
unsigned int i, j;
for (i = 0; i < utn->n_tables; i++)
for (j = 0; j < info->tables[i].n_entries; j++)
if (!udp_tunnel_nic_entry_is_free(&utn->entries[i][j]))
return false;
return true;
}
static bool
udp_tunnel_nic_should_replay(struct net_device *dev, struct udp_tunnel_nic *utn)
{
const struct udp_tunnel_nic_table_info *table;
unsigned int i, j;
if (!utn->missed)
return false;
for (i = 0; i < utn->n_tables; i++) {
table = &dev->udp_tunnel_nic_info->tables[i];
if (!test_bit(i, &utn->missed))
continue;
for (j = 0; j < table->n_entries; j++)
if (udp_tunnel_nic_entry_is_free(&utn->entries[i][j]))
return true;
}
return false;
}
static void
__udp_tunnel_nic_get_port(struct net_device *dev, unsigned int table,
unsigned int idx, struct udp_tunnel_info *ti)
{
struct udp_tunnel_nic_table_entry *entry;
struct udp_tunnel_nic *utn;
utn = dev->udp_tunnel_nic;
entry = &utn->entries[table][idx];
if (entry->use_cnt)
udp_tunnel_nic_ti_from_entry(entry, ti);
}
static void
__udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table,
unsigned int idx, u8 priv)
{
dev->udp_tunnel_nic->entries[table][idx].hw_priv = priv;
}
static void
udp_tunnel_nic_entry_update_done(struct udp_tunnel_nic_table_entry *entry,
int err)
{
bool dodgy = entry->flags & UDP_TUNNEL_NIC_ENTRY_OP_FAIL;
WARN_ON_ONCE(entry->flags & UDP_TUNNEL_NIC_ENTRY_ADD &&
entry->flags & UDP_TUNNEL_NIC_ENTRY_DEL);
if (entry->flags & UDP_TUNNEL_NIC_ENTRY_ADD &&
(!err || (err == -EEXIST && dodgy)))
entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_ADD;
if (entry->flags & UDP_TUNNEL_NIC_ENTRY_DEL &&
(!err || (err == -ENOENT && dodgy)))
entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_DEL;
if (!err)
entry->flags &= ~UDP_TUNNEL_NIC_ENTRY_OP_FAIL;
else
entry->flags |= UDP_TUNNEL_NIC_ENTRY_OP_FAIL;
}
static void
udp_tunnel_nic_device_sync_one(struct net_device *dev,
struct udp_tunnel_nic *utn,
unsigned int table, unsigned int idx)
{
struct udp_tunnel_nic_table_entry *entry;
struct udp_tunnel_info ti;
int err;
entry = &utn->entries[table][idx];
if (!udp_tunnel_nic_entry_is_queued(entry))
return;
udp_tunnel_nic_ti_from_entry(entry, &ti);
if (entry->flags & UDP_TUNNEL_NIC_ENTRY_ADD)
err = dev->udp_tunnel_nic_info->set_port(dev, table, idx, &ti);
else
err = dev->udp_tunnel_nic_info->unset_port(dev, table, idx,
&ti);
udp_tunnel_nic_entry_update_done(entry, err);
if (err)
netdev_warn(dev,
"UDP tunnel port sync failed port %d type %s: %d\n",
be16_to_cpu(entry->port),
udp_tunnel_nic_tunnel_type_name(entry->type),
err);
}
static void
udp_tunnel_nic_device_sync_by_port(struct net_device *dev,
struct udp_tunnel_nic *utn)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
unsigned int i, j;
for (i = 0; i < utn->n_tables; i++)
for (j = 0; j < info->tables[i].n_entries; j++)
udp_tunnel_nic_device_sync_one(dev, utn, i, j);
}
static void
udp_tunnel_nic_device_sync_by_table(struct net_device *dev,
struct udp_tunnel_nic *utn)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
unsigned int i, j;
int err;
for (i = 0; i < utn->n_tables; i++) {
/* Find something that needs sync in this table */
for (j = 0; j < info->tables[i].n_entries; j++)
if (udp_tunnel_nic_entry_is_queued(&utn->entries[i][j]))
break;
if (j == info->tables[i].n_entries)
continue;
err = info->sync_table(dev, i);
if (err)
netdev_warn(dev, "UDP tunnel port sync failed for table %d: %d\n",
i, err);
for (j = 0; j < info->tables[i].n_entries; j++) {
struct udp_tunnel_nic_table_entry *entry;
entry = &utn->entries[i][j];
if (udp_tunnel_nic_entry_is_queued(entry))
udp_tunnel_nic_entry_update_done(entry, err);
}
}
}
static void
__udp_tunnel_nic_device_sync(struct net_device *dev, struct udp_tunnel_nic *utn)
{
if (!utn->need_sync)
return;
if (dev->udp_tunnel_nic_info->sync_table)
udp_tunnel_nic_device_sync_by_table(dev, utn);
else
udp_tunnel_nic_device_sync_by_port(dev, utn);
utn->need_sync = 0;
/* Can't replay directly here, in case we come from the tunnel driver's
* notification - trying to replay may deadlock inside tunnel driver.
*/
utn->need_replay = udp_tunnel_nic_should_replay(dev, utn);
}
static void
udp_tunnel_nic_device_sync(struct net_device *dev, struct udp_tunnel_nic *utn)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
bool may_sleep;
if (!utn->need_sync)
return;
/* Drivers which sleep in the callback need to update from
* the workqueue, if we come from the tunnel driver's notification.
*/
may_sleep = info->flags & UDP_TUNNEL_NIC_INFO_MAY_SLEEP;
if (!may_sleep)
__udp_tunnel_nic_device_sync(dev, utn);
if (may_sleep || utn->need_replay) {
queue_work(udp_tunnel_nic_workqueue, &utn->work);
utn->work_pending = 1;
}
}
static bool
udp_tunnel_nic_table_is_capable(const struct udp_tunnel_nic_table_info *table,
struct udp_tunnel_info *ti)
{
return table->tunnel_types & ti->type;
}
static bool
udp_tunnel_nic_is_capable(struct net_device *dev, struct udp_tunnel_nic *utn,
struct udp_tunnel_info *ti)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
unsigned int i;
/* Special case IPv4-only NICs */
if (info->flags & UDP_TUNNEL_NIC_INFO_IPV4_ONLY &&
ti->sa_family != AF_INET)
return false;
for (i = 0; i < utn->n_tables; i++)
if (udp_tunnel_nic_table_is_capable(&info->tables[i], ti))
return true;
return false;
}
static int
udp_tunnel_nic_has_collision(struct net_device *dev, struct udp_tunnel_nic *utn,
struct udp_tunnel_info *ti)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
struct udp_tunnel_nic_table_entry *entry;
unsigned int i, j;
for (i = 0; i < utn->n_tables; i++)
for (j = 0; j < info->tables[i].n_entries; j++) {
entry = &utn->entries[i][j];
if (!udp_tunnel_nic_entry_is_free(entry) &&
entry->port == ti->port &&
entry->type != ti->type) {
__set_bit(i, &utn->missed);
return true;
}
}
return false;
}
static void
udp_tunnel_nic_entry_adj(struct udp_tunnel_nic *utn,
unsigned int table, unsigned int idx, int use_cnt_adj)
{
struct udp_tunnel_nic_table_entry *entry = &utn->entries[table][idx];
bool dodgy = entry->flags & UDP_TUNNEL_NIC_ENTRY_OP_FAIL;
unsigned int from, to;
WARN_ON(entry->use_cnt + (u32)use_cnt_adj > U16_MAX);
/* If not going from used to unused or vice versa - all done.
* For dodgy entries make sure we try to sync again (queue the entry).
*/
entry->use_cnt += use_cnt_adj;
if (!dodgy && !entry->use_cnt == !(entry->use_cnt - use_cnt_adj))
return;
/* Cancel the op before it was sent to the device, if possible,
* otherwise we'd need to take special care to issue commands
* in the same order the ports arrived.
*/
if (use_cnt_adj < 0) {
from = UDP_TUNNEL_NIC_ENTRY_ADD;
to = UDP_TUNNEL_NIC_ENTRY_DEL;
} else {
from = UDP_TUNNEL_NIC_ENTRY_DEL;
to = UDP_TUNNEL_NIC_ENTRY_ADD;
}
if (entry->flags & from) {
entry->flags &= ~from;
if (!dodgy)
return;
}
udp_tunnel_nic_entry_queue(utn, entry, to);
}
static bool
udp_tunnel_nic_entry_try_adj(struct udp_tunnel_nic *utn,
unsigned int table, unsigned int idx,
struct udp_tunnel_info *ti, int use_cnt_adj)
{
struct udp_tunnel_nic_table_entry *entry = &utn->entries[table][idx];
if (udp_tunnel_nic_entry_is_free(entry) ||
entry->port != ti->port ||
entry->type != ti->type)
return false;
if (udp_tunnel_nic_entry_is_frozen(entry))
return true;
udp_tunnel_nic_entry_adj(utn, table, idx, use_cnt_adj);
return true;
}
/* Try to find existing matching entry and adjust its use count, instead of
* adding a new one. Returns true if entry was found. In case of delete the
* entry may have gotten removed in the process, in which case it will be
* queued for removal.
*/
static bool
udp_tunnel_nic_try_existing(struct net_device *dev, struct udp_tunnel_nic *utn,
struct udp_tunnel_info *ti, int use_cnt_adj)
{
const struct udp_tunnel_nic_table_info *table;
unsigned int i, j;
for (i = 0; i < utn->n_tables; i++) {
table = &dev->udp_tunnel_nic_info->tables[i];
if (!udp_tunnel_nic_table_is_capable(table, ti))
continue;
for (j = 0; j < table->n_entries; j++)
if (udp_tunnel_nic_entry_try_adj(utn, i, j, ti,
use_cnt_adj))
return true;
}
return false;
}
static bool
udp_tunnel_nic_add_existing(struct net_device *dev, struct udp_tunnel_nic *utn,
struct udp_tunnel_info *ti)
{
return udp_tunnel_nic_try_existing(dev, utn, ti, +1);
}
static bool
udp_tunnel_nic_del_existing(struct net_device *dev, struct udp_tunnel_nic *utn,
struct udp_tunnel_info *ti)
{
return udp_tunnel_nic_try_existing(dev, utn, ti, -1);
}
static bool
udp_tunnel_nic_add_new(struct net_device *dev, struct udp_tunnel_nic *utn,
struct udp_tunnel_info *ti)
{
const struct udp_tunnel_nic_table_info *table;
unsigned int i, j;
for (i = 0; i < utn->n_tables; i++) {
table = &dev->udp_tunnel_nic_info->tables[i];
if (!udp_tunnel_nic_table_is_capable(table, ti))
continue;
for (j = 0; j < table->n_entries; j++) {
struct udp_tunnel_nic_table_entry *entry;
entry = &utn->entries[i][j];
if (!udp_tunnel_nic_entry_is_free(entry))
continue;
entry->port = ti->port;
entry->type = ti->type;
entry->use_cnt = 1;
udp_tunnel_nic_entry_queue(utn, entry,
UDP_TUNNEL_NIC_ENTRY_ADD);
return true;
}
/* The different table may still fit this port in, but there
* are no devices currently which have multiple tables accepting
* the same tunnel type, and false positives are okay.
*/
__set_bit(i, &utn->missed);
}
return false;
}
static void
__udp_tunnel_nic_add_port(struct net_device *dev, struct udp_tunnel_info *ti)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
struct udp_tunnel_nic *utn;
utn = dev->udp_tunnel_nic;
if (!utn)
return;
if (!netif_running(dev) && info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY)
return;
if (info->flags & UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN &&
ti->port == htons(IANA_VXLAN_UDP_PORT)) {
if (ti->type != UDP_TUNNEL_TYPE_VXLAN)
netdev_warn(dev, "device assumes port 4789 will be used by vxlan tunnels\n");
return;
}
if (!udp_tunnel_nic_is_capable(dev, utn, ti))
return;
/* It may happen that a tunnel of one type is removed and different
* tunnel type tries to reuse its port before the device was informed.
* Rely on utn->missed to re-add this port later.
*/
if (udp_tunnel_nic_has_collision(dev, utn, ti))
return;
if (!udp_tunnel_nic_add_existing(dev, utn, ti))
udp_tunnel_nic_add_new(dev, utn, ti);
udp_tunnel_nic_device_sync(dev, utn);
}
static void
__udp_tunnel_nic_del_port(struct net_device *dev, struct udp_tunnel_info *ti)
{
struct udp_tunnel_nic *utn;
utn = dev->udp_tunnel_nic;
if (!utn)
return;
if (!udp_tunnel_nic_is_capable(dev, utn, ti))
return;
udp_tunnel_nic_del_existing(dev, utn, ti);
udp_tunnel_nic_device_sync(dev, utn);
}
static void __udp_tunnel_nic_reset_ntf(struct net_device *dev)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
struct udp_tunnel_nic *utn;
unsigned int i, j;
ASSERT_RTNL();
utn = dev->udp_tunnel_nic;
if (!utn)
return;
utn->need_sync = false;
for (i = 0; i < utn->n_tables; i++)
for (j = 0; j < info->tables[i].n_entries; j++) {
struct udp_tunnel_nic_table_entry *entry;
entry = &utn->entries[i][j];
entry->flags &= ~(UDP_TUNNEL_NIC_ENTRY_DEL |
UDP_TUNNEL_NIC_ENTRY_OP_FAIL);
/* We don't release rtnl across ops */
WARN_ON(entry->flags & UDP_TUNNEL_NIC_ENTRY_FROZEN);
if (!entry->use_cnt)
continue;
udp_tunnel_nic_entry_queue(utn, entry,
UDP_TUNNEL_NIC_ENTRY_ADD);
}
__udp_tunnel_nic_device_sync(dev, utn);
}
static size_t
__udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
struct udp_tunnel_nic *utn;
unsigned int j;
size_t size;
utn = dev->udp_tunnel_nic;
if (!utn)
return 0;
size = 0;
for (j = 0; j < info->tables[table].n_entries; j++) {
if (!udp_tunnel_nic_entry_is_present(&utn->entries[table][j]))
continue;
size += nla_total_size(0) + /* _TABLE_ENTRY */
nla_total_size(sizeof(__be16)) + /* _ENTRY_PORT */
nla_total_size(sizeof(u32)); /* _ENTRY_TYPE */
}
return size;
}
static int
__udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
struct sk_buff *skb)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
struct udp_tunnel_nic *utn;
struct nlattr *nest;
unsigned int j;
utn = dev->udp_tunnel_nic;
if (!utn)
return 0;
for (j = 0; j < info->tables[table].n_entries; j++) {
if (!udp_tunnel_nic_entry_is_present(&utn->entries[table][j]))
continue;
nest = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY);
if (nla_put_be16(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT,
utn->entries[table][j].port) ||
nla_put_u32(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE,
ilog2(utn->entries[table][j].type)))
goto err_cancel;
nla_nest_end(skb, nest);
}
return 0;
err_cancel:
nla_nest_cancel(skb, nest);
return -EMSGSIZE;
}
static const struct udp_tunnel_nic_ops __udp_tunnel_nic_ops = {
.get_port = __udp_tunnel_nic_get_port,
.set_port_priv = __udp_tunnel_nic_set_port_priv,
.add_port = __udp_tunnel_nic_add_port,
.del_port = __udp_tunnel_nic_del_port,
.reset_ntf = __udp_tunnel_nic_reset_ntf,
.dump_size = __udp_tunnel_nic_dump_size,
.dump_write = __udp_tunnel_nic_dump_write,
};
static void
udp_tunnel_nic_flush(struct net_device *dev, struct udp_tunnel_nic *utn)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
unsigned int i, j;
for (i = 0; i < utn->n_tables; i++)
for (j = 0; j < info->tables[i].n_entries; j++) {
int adj_cnt = -utn->entries[i][j].use_cnt;
if (adj_cnt)
udp_tunnel_nic_entry_adj(utn, i, j, adj_cnt);
}
__udp_tunnel_nic_device_sync(dev, utn);
for (i = 0; i < utn->n_tables; i++)
memset(utn->entries[i], 0, array_size(info->tables[i].n_entries,
sizeof(**utn->entries)));
WARN_ON(utn->need_sync);
utn->need_replay = 0;
}
static void
udp_tunnel_nic_replay(struct net_device *dev, struct udp_tunnel_nic *utn)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
struct udp_tunnel_nic_shared_node *node;
unsigned int i, j;
/* Freeze all the ports we are already tracking so that the replay
* does not double up the refcount.
*/
for (i = 0; i < utn->n_tables; i++)
for (j = 0; j < info->tables[i].n_entries; j++)
udp_tunnel_nic_entry_freeze_used(&utn->entries[i][j]);
utn->missed = 0;
utn->need_replay = 0;
if (!info->shared) {
udp_tunnel_get_rx_info(dev);
} else {
list_for_each_entry(node, &info->shared->devices, list)
udp_tunnel_get_rx_info(node->dev);
}
for (i = 0; i < utn->n_tables; i++)
for (j = 0; j < info->tables[i].n_entries; j++)
udp_tunnel_nic_entry_unfreeze(&utn->entries[i][j]);
}
static void udp_tunnel_nic_device_sync_work(struct work_struct *work)
{
struct udp_tunnel_nic *utn =
container_of(work, struct udp_tunnel_nic, work);
rtnl_lock();
utn->work_pending = 0;
__udp_tunnel_nic_device_sync(utn->dev, utn);
if (utn->need_replay)
udp_tunnel_nic_replay(utn->dev, utn);
rtnl_unlock();
}
static struct udp_tunnel_nic *
udp_tunnel_nic_alloc(const struct udp_tunnel_nic_info *info,
unsigned int n_tables)
{
struct udp_tunnel_nic *utn;
unsigned int i;
utn = kzalloc(sizeof(*utn), GFP_KERNEL);
if (!utn)
return NULL;
utn->n_tables = n_tables;
INIT_WORK(&utn->work, udp_tunnel_nic_device_sync_work);
utn->entries = kmalloc_array(n_tables, sizeof(void *), GFP_KERNEL);
if (!utn->entries)
goto err_free_utn;
for (i = 0; i < n_tables; i++) {
utn->entries[i] = kcalloc(info->tables[i].n_entries,
sizeof(*utn->entries[i]), GFP_KERNEL);
if (!utn->entries[i])
goto err_free_prev_entries;
}
return utn;
err_free_prev_entries:
while (i--)
kfree(utn->entries[i]);
kfree(utn->entries);
err_free_utn:
kfree(utn);
return NULL;
}
static void udp_tunnel_nic_free(struct udp_tunnel_nic *utn)
{
unsigned int i;
for (i = 0; i < utn->n_tables; i++)
kfree(utn->entries[i]);
kfree(utn->entries);
kfree(utn);
}
static int udp_tunnel_nic_register(struct net_device *dev)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
struct udp_tunnel_nic_shared_node *node = NULL;
struct udp_tunnel_nic *utn;
unsigned int n_tables, i;
BUILD_BUG_ON(sizeof(utn->missed) * BITS_PER_BYTE <
UDP_TUNNEL_NIC_MAX_TABLES);
/* Expect use count of at most 2 (IPv4, IPv6) per device */
BUILD_BUG_ON(UDP_TUNNEL_NIC_USE_CNT_MAX <
UDP_TUNNEL_NIC_MAX_SHARING_DEVICES * 2);
/* Check that the driver info is sane */
if (WARN_ON(!info->set_port != !info->unset_port) ||
WARN_ON(!info->set_port == !info->sync_table) ||
WARN_ON(!info->tables[0].n_entries))
return -EINVAL;
if (WARN_ON(info->shared &&
info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY))
return -EINVAL;
n_tables = 1;
for (i = 1; i < UDP_TUNNEL_NIC_MAX_TABLES; i++) {
if (!info->tables[i].n_entries)
continue;
n_tables++;
if (WARN_ON(!info->tables[i - 1].n_entries))
return -EINVAL;
}
/* Create UDP tunnel state structures */
if (info->shared) {
node = kzalloc(sizeof(*node), GFP_KERNEL);
if (!node)
return -ENOMEM;
node->dev = dev;
}
if (info->shared && info->shared->udp_tunnel_nic_info) {
utn = info->shared->udp_tunnel_nic_info;
} else {
utn = udp_tunnel_nic_alloc(info, n_tables);
if (!utn) {
kfree(node);
return -ENOMEM;
}
}
if (info->shared) {
if (!info->shared->udp_tunnel_nic_info) {
INIT_LIST_HEAD(&info->shared->devices);
info->shared->udp_tunnel_nic_info = utn;
}
list_add_tail(&node->list, &info->shared->devices);
}
utn->dev = dev;
dev_hold(dev);
dev->udp_tunnel_nic = utn;
if (!(info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY))
udp_tunnel_get_rx_info(dev);
return 0;
}
static void
udp_tunnel_nic_unregister(struct net_device *dev, struct udp_tunnel_nic *utn)
{
const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
/* For a shared table remove this dev from the list of sharing devices
* and if there are other devices just detach.
*/
if (info->shared) {
struct udp_tunnel_nic_shared_node *node, *first;
list_for_each_entry(node, &info->shared->devices, list)
if (node->dev == dev)
break;
if (node->dev != dev)
return;
list_del(&node->list);
kfree(node);
first = list_first_entry_or_null(&info->shared->devices,
typeof(*first), list);
if (first) {
udp_tunnel_drop_rx_info(dev);
utn->dev = first->dev;
goto release_dev;
}
info->shared->udp_tunnel_nic_info = NULL;
}
/* Flush before we check work, so we don't waste time adding entries
* from the work which we will boot immediately.
*/
udp_tunnel_nic_flush(dev, utn);
/* Wait for the work to be done using the state, netdev core will
* retry unregister until we give up our reference on this device.
*/
if (utn->work_pending)
return;
udp_tunnel_nic_free(utn);
release_dev:
dev->udp_tunnel_nic = NULL;
dev_put(dev);
}
static int
udp_tunnel_nic_netdevice_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
const struct udp_tunnel_nic_info *info;
struct udp_tunnel_nic *utn;
info = dev->udp_tunnel_nic_info;
if (!info)
return NOTIFY_DONE;
if (event == NETDEV_REGISTER) {
int err;
err = udp_tunnel_nic_register(dev);
if (err)
netdev_WARN(dev, "failed to register for UDP tunnel offloads: %d", err);
return notifier_from_errno(err);
}
/* All other events will need the udp_tunnel_nic state */
utn = dev->udp_tunnel_nic;
if (!utn)
return NOTIFY_DONE;
if (event == NETDEV_UNREGISTER) {
udp_tunnel_nic_unregister(dev, utn);
return NOTIFY_OK;
}
/* All other events only matter if NIC has to be programmed open */
if (!(info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY))
return NOTIFY_DONE;
if (event == NETDEV_UP) {
WARN_ON(!udp_tunnel_nic_is_empty(dev, utn));
udp_tunnel_get_rx_info(dev);
return NOTIFY_OK;
}
if (event == NETDEV_GOING_DOWN) {
udp_tunnel_nic_flush(dev, utn);
return NOTIFY_OK;
}
return NOTIFY_DONE;
}
static struct notifier_block udp_tunnel_nic_notifier_block __read_mostly = {
.notifier_call = udp_tunnel_nic_netdevice_event,
};
static int __init udp_tunnel_nic_init_module(void)
{
int err;
udp_tunnel_nic_workqueue = alloc_workqueue("udp_tunnel_nic", 0, 0);
if (!udp_tunnel_nic_workqueue)
return -ENOMEM;
rtnl_lock();
udp_tunnel_nic_ops = &__udp_tunnel_nic_ops;
rtnl_unlock();
err = register_netdevice_notifier(&udp_tunnel_nic_notifier_block);
if (err)
goto err_unset_ops;
return 0;
err_unset_ops:
rtnl_lock();
udp_tunnel_nic_ops = NULL;
rtnl_unlock();
destroy_workqueue(udp_tunnel_nic_workqueue);
return err;
}
late_initcall(udp_tunnel_nic_init_module);
static void __exit udp_tunnel_nic_cleanup_module(void)
{
unregister_netdevice_notifier(&udp_tunnel_nic_notifier_block);
rtnl_lock();
udp_tunnel_nic_ops = NULL;
rtnl_unlock();
destroy_workqueue(udp_tunnel_nic_workqueue);
}
module_exit(udp_tunnel_nic_cleanup_module);
MODULE_LICENSE("GPL");