blob: a6d983d80576ad3db7960aad67d771370977301f [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/* Multipath TCP
*
* Copyright (c) 2020, Red Hat, Inc.
*/
#define pr_fmt(fmt) "MPTCP: " fmt
#include <linux/inet.h>
#include <linux/kernel.h>
#include <net/tcp.h>
#include <net/netns/generic.h>
#include <net/mptcp.h>
#include <net/genetlink.h>
#include <uapi/linux/mptcp.h>
#include "protocol.h"
#include "mib.h"
/* forward declaration */
static struct genl_family mptcp_genl_family;
static int pm_nl_pernet_id;
struct mptcp_pm_addr_entry {
struct list_head list;
struct mptcp_addr_info addr;
struct rcu_head rcu;
};
struct mptcp_pm_add_entry {
struct list_head list;
struct mptcp_addr_info addr;
struct timer_list add_timer;
struct mptcp_sock *sock;
u8 retrans_times;
};
struct pm_nl_pernet {
/* protects pernet updates */
spinlock_t lock;
struct list_head local_addr_list;
unsigned int addrs;
unsigned int add_addr_signal_max;
unsigned int add_addr_accept_max;
unsigned int local_addr_max;
unsigned int subflows_max;
unsigned int next_id;
};
#define MPTCP_PM_ADDR_MAX 8
#define ADD_ADDR_RETRANS_MAX 3
static bool addresses_equal(const struct mptcp_addr_info *a,
struct mptcp_addr_info *b, bool use_port)
{
bool addr_equals = false;
if (a->family != b->family)
return false;
if (a->family == AF_INET)
addr_equals = a->addr.s_addr == b->addr.s_addr;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
else
addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
#endif
if (!addr_equals)
return false;
if (!use_port)
return true;
return a->port == b->port;
}
static bool address_zero(const struct mptcp_addr_info *addr)
{
struct mptcp_addr_info zero;
memset(&zero, 0, sizeof(zero));
zero.family = addr->family;
return addresses_equal(addr, &zero, false);
}
static void local_address(const struct sock_common *skc,
struct mptcp_addr_info *addr)
{
addr->port = 0;
addr->family = skc->skc_family;
if (addr->family == AF_INET)
addr->addr.s_addr = skc->skc_rcv_saddr;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
else if (addr->family == AF_INET6)
addr->addr6 = skc->skc_v6_rcv_saddr;
#endif
}
static void remote_address(const struct sock_common *skc,
struct mptcp_addr_info *addr)
{
addr->family = skc->skc_family;
addr->port = skc->skc_dport;
if (addr->family == AF_INET)
addr->addr.s_addr = skc->skc_daddr;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
else if (addr->family == AF_INET6)
addr->addr6 = skc->skc_v6_daddr;
#endif
}
static bool lookup_subflow_by_saddr(const struct list_head *list,
struct mptcp_addr_info *saddr)
{
struct mptcp_subflow_context *subflow;
struct mptcp_addr_info cur;
struct sock_common *skc;
list_for_each_entry(subflow, list, node) {
skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
local_address(skc, &cur);
if (addresses_equal(&cur, saddr, false))
return true;
}
return false;
}
static struct mptcp_pm_addr_entry *
select_local_address(const struct pm_nl_pernet *pernet,
struct mptcp_sock *msk)
{
struct mptcp_pm_addr_entry *entry, *ret = NULL;
rcu_read_lock();
__mptcp_flush_join_list(msk);
list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
continue;
/* avoid any address already in use by subflows and
* pending join
*/
if (entry->addr.family == ((struct sock *)msk)->sk_family &&
!lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) {
ret = entry;
break;
}
}
rcu_read_unlock();
return ret;
}
static struct mptcp_pm_addr_entry *
select_signal_address(struct pm_nl_pernet *pernet, unsigned int pos)
{
struct mptcp_pm_addr_entry *entry, *ret = NULL;
int i = 0;
rcu_read_lock();
/* do not keep any additional per socket state, just signal
* the address list in order.
* Note: removal from the local address list during the msk life-cycle
* can lead to additional addresses not being announced.
*/
list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
continue;
if (i++ == pos) {
ret = entry;
break;
}
}
rcu_read_unlock();
return ret;
}
static void check_work_pending(struct mptcp_sock *msk)
{
if (msk->pm.add_addr_signaled == msk->pm.add_addr_signal_max &&
(msk->pm.local_addr_used == msk->pm.local_addr_max ||
msk->pm.subflows == msk->pm.subflows_max))
WRITE_ONCE(msk->pm.work_pending, false);
}
static struct mptcp_pm_add_entry *
lookup_anno_list_by_saddr(struct mptcp_sock *msk,
struct mptcp_addr_info *addr)
{
struct mptcp_pm_add_entry *entry;
list_for_each_entry(entry, &msk->pm.anno_list, list) {
if (addresses_equal(&entry->addr, addr, false))
return entry;
}
return NULL;
}
static void mptcp_pm_add_timer(struct timer_list *timer)
{
struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
struct mptcp_sock *msk = entry->sock;
struct sock *sk = (struct sock *)msk;
pr_debug("msk=%p", msk);
if (!msk)
return;
if (inet_sk_state_load(sk) == TCP_CLOSE)
return;
if (!entry->addr.id)
return;
if (mptcp_pm_should_add_signal(msk)) {
sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
goto out;
}
spin_lock_bh(&msk->pm.lock);
if (!mptcp_pm_should_add_signal(msk)) {
pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
mptcp_pm_announce_addr(msk, &entry->addr, false, entry->addr.port);
mptcp_pm_add_addr_send_ack(msk);
entry->retrans_times++;
}
if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
sk_reset_timer(sk, timer,
jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
spin_unlock_bh(&msk->pm.lock);
out:
__sock_put(sk);
}
struct mptcp_pm_add_entry *
mptcp_pm_del_add_timer(struct mptcp_sock *msk,
struct mptcp_addr_info *addr)
{
struct mptcp_pm_add_entry *entry;
struct sock *sk = (struct sock *)msk;
spin_lock_bh(&msk->pm.lock);
entry = lookup_anno_list_by_saddr(msk, addr);
if (entry)
entry->retrans_times = ADD_ADDR_RETRANS_MAX;
spin_unlock_bh(&msk->pm.lock);
if (entry)
sk_stop_timer_sync(sk, &entry->add_timer);
return entry;
}
static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
struct mptcp_pm_addr_entry *entry)
{
struct mptcp_pm_add_entry *add_entry = NULL;
struct sock *sk = (struct sock *)msk;
struct net *net = sock_net(sk);
if (lookup_anno_list_by_saddr(msk, &entry->addr))
return false;
add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
if (!add_entry)
return false;
list_add(&add_entry->list, &msk->pm.anno_list);
add_entry->addr = entry->addr;
add_entry->sock = msk;
add_entry->retrans_times = 0;
timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
sk_reset_timer(sk, &add_entry->add_timer,
jiffies + mptcp_get_add_addr_timeout(net));
return true;
}
void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
{
struct mptcp_pm_add_entry *entry, *tmp;
struct sock *sk = (struct sock *)msk;
LIST_HEAD(free_list);
pr_debug("msk=%p", msk);
spin_lock_bh(&msk->pm.lock);
list_splice_init(&msk->pm.anno_list, &free_list);
spin_unlock_bh(&msk->pm.lock);
list_for_each_entry_safe(entry, tmp, &free_list, list) {
sk_stop_timer_sync(sk, &entry->add_timer);
kfree(entry);
}
}
static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
{
struct mptcp_addr_info remote = { 0 };
struct sock *sk = (struct sock *)msk;
struct mptcp_pm_addr_entry *local;
struct pm_nl_pernet *pernet;
pernet = net_generic(sock_net(sk), pm_nl_pernet_id);
pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
msk->pm.local_addr_used, msk->pm.local_addr_max,
msk->pm.add_addr_signaled, msk->pm.add_addr_signal_max,
msk->pm.subflows, msk->pm.subflows_max);
/* check first for announce */
if (msk->pm.add_addr_signaled < msk->pm.add_addr_signal_max) {
local = select_signal_address(pernet,
msk->pm.add_addr_signaled);
if (local) {
if (mptcp_pm_alloc_anno_list(msk, local)) {
msk->pm.add_addr_signaled++;
mptcp_pm_announce_addr(msk, &local->addr, false, local->addr.port);
mptcp_pm_nl_add_addr_send_ack(msk);
}
} else {
/* pick failed, avoid fourther attempts later */
msk->pm.local_addr_used = msk->pm.add_addr_signal_max;
}
check_work_pending(msk);
}
/* check if should create a new subflow */
if (msk->pm.local_addr_used < msk->pm.local_addr_max &&
msk->pm.subflows < msk->pm.subflows_max) {
remote_address((struct sock_common *)sk, &remote);
local = select_local_address(pernet, msk);
if (local) {
msk->pm.local_addr_used++;
msk->pm.subflows++;
check_work_pending(msk);
spin_unlock_bh(&msk->pm.lock);
__mptcp_subflow_connect(sk, &local->addr, &remote);
spin_lock_bh(&msk->pm.lock);
return;
}
/* lookup failed, avoid fourther attempts later */
msk->pm.local_addr_used = msk->pm.local_addr_max;
check_work_pending(msk);
}
}
void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
{
mptcp_pm_create_subflow_or_signal_addr(msk);
}
void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
{
mptcp_pm_create_subflow_or_signal_addr(msk);
}
void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
{
struct sock *sk = (struct sock *)msk;
struct mptcp_addr_info remote;
struct mptcp_addr_info local;
bool use_port = false;
pr_debug("accepted %d:%d remote family %d",
msk->pm.add_addr_accepted, msk->pm.add_addr_accept_max,
msk->pm.remote.family);
msk->pm.add_addr_accepted++;
msk->pm.subflows++;
if (msk->pm.add_addr_accepted >= msk->pm.add_addr_accept_max ||
msk->pm.subflows >= msk->pm.subflows_max)
WRITE_ONCE(msk->pm.accept_addr, false);
/* connect to the specified remote address, using whatever
* local address the routing configuration will pick.
*/
remote = msk->pm.remote;
if (!remote.port)
remote.port = sk->sk_dport;
else
use_port = true;
memset(&local, 0, sizeof(local));
local.family = remote.family;
spin_unlock_bh(&msk->pm.lock);
__mptcp_subflow_connect(sk, &local, &remote);
spin_lock_bh(&msk->pm.lock);
mptcp_pm_announce_addr(msk, &remote, true, use_port);
mptcp_pm_nl_add_addr_send_ack(msk);
}
void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk)
{
struct mptcp_subflow_context *subflow;
if (!mptcp_pm_should_add_signal_ipv6(msk) &&
!mptcp_pm_should_add_signal_port(msk))
return;
__mptcp_flush_join_list(msk);
subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node);
if (subflow) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
u8 add_addr;
spin_unlock_bh(&msk->pm.lock);
if (mptcp_pm_should_add_signal_ipv6(msk))
pr_debug("send ack for add_addr6");
if (mptcp_pm_should_add_signal_port(msk))
pr_debug("send ack for add_addr_port");
lock_sock(ssk);
tcp_send_ack(ssk);
release_sock(ssk);
spin_lock_bh(&msk->pm.lock);
add_addr = READ_ONCE(msk->pm.addr_signal);
if (mptcp_pm_should_add_signal_ipv6(msk))
add_addr &= ~BIT(MPTCP_ADD_ADDR_IPV6);
if (mptcp_pm_should_add_signal_port(msk))
add_addr &= ~BIT(MPTCP_ADD_ADDR_PORT);
WRITE_ONCE(msk->pm.addr_signal, add_addr);
}
}
void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
{
struct mptcp_subflow_context *subflow, *tmp;
struct sock *sk = (struct sock *)msk;
pr_debug("address rm_id %d", msk->pm.rm_id);
if (!msk->pm.rm_id)
return;
if (list_empty(&msk->conn_list))
return;
list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
if (msk->pm.rm_id != subflow->remote_id)
continue;
spin_unlock_bh(&msk->pm.lock);
mptcp_subflow_shutdown(sk, ssk, how);
__mptcp_close_ssk(sk, ssk, subflow);
spin_lock_bh(&msk->pm.lock);
msk->pm.add_addr_accepted--;
msk->pm.subflows--;
WRITE_ONCE(msk->pm.accept_addr, true);
__MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMADDR);
break;
}
}
void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id)
{
struct mptcp_subflow_context *subflow, *tmp;
struct sock *sk = (struct sock *)msk;
pr_debug("subflow rm_id %d", rm_id);
if (!rm_id)
return;
if (list_empty(&msk->conn_list))
return;
list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
if (rm_id != subflow->local_id)
continue;
spin_unlock_bh(&msk->pm.lock);
mptcp_subflow_shutdown(sk, ssk, how);
__mptcp_close_ssk(sk, ssk, subflow);
spin_lock_bh(&msk->pm.lock);
msk->pm.local_addr_used--;
msk->pm.subflows--;
__MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
break;
}
}
static bool address_use_port(struct mptcp_pm_addr_entry *entry)
{
return (entry->addr.flags &
(MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
MPTCP_PM_ADDR_FLAG_SIGNAL;
}
static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
struct mptcp_pm_addr_entry *entry)
{
struct mptcp_pm_addr_entry *cur;
int ret = -EINVAL;
spin_lock_bh(&pernet->lock);
/* to keep the code simple, don't do IDR-like allocation for address ID,
* just bail when we exceed limits
*/
if (pernet->next_id > 255)
goto out;
if (pernet->addrs >= MPTCP_PM_ADDR_MAX)
goto out;
/* do not insert duplicate address, differentiate on port only
* singled addresses
*/
list_for_each_entry(cur, &pernet->local_addr_list, list) {
if (addresses_equal(&cur->addr, &entry->addr,
address_use_port(entry) &&
address_use_port(cur)))
goto out;
}
if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)
pernet->add_addr_signal_max++;
if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
pernet->local_addr_max++;
entry->addr.id = pernet->next_id++;
pernet->addrs++;
list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
ret = entry->addr.id;
out:
spin_unlock_bh(&pernet->lock);
return ret;
}
int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
{
struct mptcp_pm_addr_entry *entry;
struct mptcp_addr_info skc_local;
struct mptcp_addr_info msk_local;
struct pm_nl_pernet *pernet;
int ret = -1;
if (WARN_ON_ONCE(!msk))
return -1;
/* The 0 ID mapping is defined by the first subflow, copied into the msk
* addr
*/
local_address((struct sock_common *)msk, &msk_local);
local_address((struct sock_common *)skc, &skc_local);
if (addresses_equal(&msk_local, &skc_local, false))
return 0;
if (address_zero(&skc_local))
return 0;
pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
rcu_read_lock();
list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
if (addresses_equal(&entry->addr, &skc_local, false)) {
ret = entry->addr.id;
break;
}
}
rcu_read_unlock();
if (ret >= 0)
return ret;
/* address not found, add to local list */
entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
if (!entry)
return -ENOMEM;
entry->addr = skc_local;
entry->addr.ifindex = 0;
entry->addr.flags = 0;
ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
if (ret < 0)
kfree(entry);
return ret;
}
void mptcp_pm_nl_data_init(struct mptcp_sock *msk)
{
struct mptcp_pm_data *pm = &msk->pm;
struct pm_nl_pernet *pernet;
bool subflows;
pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
pm->add_addr_signal_max = READ_ONCE(pernet->add_addr_signal_max);
pm->add_addr_accept_max = READ_ONCE(pernet->add_addr_accept_max);
pm->local_addr_max = READ_ONCE(pernet->local_addr_max);
pm->subflows_max = READ_ONCE(pernet->subflows_max);
subflows = !!pm->subflows_max;
WRITE_ONCE(pm->work_pending, (!!pm->local_addr_max && subflows) ||
!!pm->add_addr_signal_max);
WRITE_ONCE(pm->accept_addr, !!pm->add_addr_accept_max && subflows);
WRITE_ONCE(pm->accept_subflow, subflows);
}
#define MPTCP_PM_CMD_GRP_OFFSET 0
static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
[MPTCP_PM_CMD_GRP_OFFSET] = { .name = MPTCP_PM_CMD_GRP_NAME, },
};
static const struct nla_policy
mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
[MPTCP_PM_ADDR_ATTR_FAMILY] = { .type = NLA_U16, },
[MPTCP_PM_ADDR_ATTR_ID] = { .type = NLA_U8, },
[MPTCP_PM_ADDR_ATTR_ADDR4] = { .type = NLA_U32, },
[MPTCP_PM_ADDR_ATTR_ADDR6] =
NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
[MPTCP_PM_ADDR_ATTR_PORT] = { .type = NLA_U16 },
[MPTCP_PM_ADDR_ATTR_FLAGS] = { .type = NLA_U32 },
[MPTCP_PM_ADDR_ATTR_IF_IDX] = { .type = NLA_S32 },
};
static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
[MPTCP_PM_ATTR_ADDR] =
NLA_POLICY_NESTED(mptcp_pm_addr_policy),
[MPTCP_PM_ATTR_RCV_ADD_ADDRS] = { .type = NLA_U32, },
[MPTCP_PM_ATTR_SUBFLOWS] = { .type = NLA_U32, },
};
static int mptcp_pm_family_to_addr(int family)
{
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
if (family == AF_INET6)
return MPTCP_PM_ADDR_ATTR_ADDR6;
#endif
return MPTCP_PM_ADDR_ATTR_ADDR4;
}
static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
bool require_family,
struct mptcp_pm_addr_entry *entry)
{
struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
int err, addr_addr;
if (!attr) {
GENL_SET_ERR_MSG(info, "missing address info");
return -EINVAL;
}
/* no validation needed - was already done via nested policy */
err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
mptcp_pm_addr_policy, info->extack);
if (err)
return err;
memset(entry, 0, sizeof(*entry));
if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
if (!require_family)
goto skip_family;
NL_SET_ERR_MSG_ATTR(info->extack, attr,
"missing family");
return -EINVAL;
}
entry->addr.family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
if (entry->addr.family != AF_INET
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
&& entry->addr.family != AF_INET6
#endif
) {
NL_SET_ERR_MSG_ATTR(info->extack, attr,
"unknown address family");
return -EINVAL;
}
addr_addr = mptcp_pm_family_to_addr(entry->addr.family);
if (!tb[addr_addr]) {
NL_SET_ERR_MSG_ATTR(info->extack, attr,
"missing address data");
return -EINVAL;
}
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
if (entry->addr.family == AF_INET6)
entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]);
else
#endif
entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]);
skip_family:
if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
entry->addr.ifindex = val;
}
if (tb[MPTCP_PM_ADDR_ATTR_ID])
entry->addr.id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
entry->addr.flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
return 0;
}
static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
{
return net_generic(genl_info_net(info), pm_nl_pernet_id);
}
static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
{
struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
struct mptcp_pm_addr_entry addr, *entry;
int ret;
ret = mptcp_pm_parse_addr(attr, info, true, &addr);
if (ret < 0)
return ret;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry) {
GENL_SET_ERR_MSG(info, "can't allocate addr");
return -ENOMEM;
}
*entry = addr;
ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
if (ret < 0) {
GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
kfree(entry);
return ret;
}
return 0;
}
static struct mptcp_pm_addr_entry *
__lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
{
struct mptcp_pm_addr_entry *entry;
list_for_each_entry(entry, &pernet->local_addr_list, list) {
if (entry->addr.id == id)
return entry;
}
return NULL;
}
static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
struct mptcp_addr_info *addr)
{
struct mptcp_pm_add_entry *entry;
entry = mptcp_pm_del_add_timer(msk, addr);
if (entry) {
list_del(&entry->list);
kfree(entry);
return true;
}
return false;
}
static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
struct mptcp_addr_info *addr,
bool force)
{
bool ret;
ret = remove_anno_list_by_saddr(msk, addr);
if (ret || force) {
spin_lock_bh(&msk->pm.lock);
mptcp_pm_remove_addr(msk, addr->id);
spin_unlock_bh(&msk->pm.lock);
}
return ret;
}
static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
struct mptcp_addr_info *addr)
{
struct mptcp_sock *msk;
long s_slot = 0, s_num = 0;
pr_debug("remove_id=%d", addr->id);
while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
struct sock *sk = (struct sock *)msk;
bool remove_subflow;
if (list_empty(&msk->conn_list)) {
mptcp_pm_remove_anno_addr(msk, addr, false);
goto next;
}
lock_sock(sk);
remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
mptcp_pm_remove_anno_addr(msk, addr, remove_subflow);
if (remove_subflow)
mptcp_pm_remove_subflow(msk, addr->id);
release_sock(sk);
next:
sock_put(sk);
cond_resched();
}
return 0;
}
static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
{
struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
struct mptcp_pm_addr_entry addr, *entry;
int ret;
ret = mptcp_pm_parse_addr(attr, info, false, &addr);
if (ret < 0)
return ret;
spin_lock_bh(&pernet->lock);
entry = __lookup_addr_by_id(pernet, addr.addr.id);
if (!entry) {
GENL_SET_ERR_MSG(info, "address not found");
spin_unlock_bh(&pernet->lock);
return -EINVAL;
}
if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)
pernet->add_addr_signal_max--;
if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
pernet->local_addr_max--;
pernet->addrs--;
list_del_rcu(&entry->list);
spin_unlock_bh(&pernet->lock);
mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), &entry->addr);
kfree_rcu(entry, rcu);
return ret;
}
static void __flush_addrs(struct net *net, struct list_head *list)
{
while (!list_empty(list)) {
struct mptcp_pm_addr_entry *cur;
cur = list_entry(list->next,
struct mptcp_pm_addr_entry, list);
mptcp_nl_remove_subflow_and_signal_addr(net, &cur->addr);
list_del_rcu(&cur->list);
kfree_rcu(cur, rcu);
}
}
static void __reset_counters(struct pm_nl_pernet *pernet)
{
pernet->add_addr_signal_max = 0;
pernet->add_addr_accept_max = 0;
pernet->local_addr_max = 0;
pernet->addrs = 0;
}
static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
{
struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
LIST_HEAD(free_list);
spin_lock_bh(&pernet->lock);
list_splice_init(&pernet->local_addr_list, &free_list);
__reset_counters(pernet);
spin_unlock_bh(&pernet->lock);
__flush_addrs(sock_net(skb->sk), &free_list);
return 0;
}
static int mptcp_nl_fill_addr(struct sk_buff *skb,
struct mptcp_pm_addr_entry *entry)
{
struct mptcp_addr_info *addr = &entry->addr;
struct nlattr *attr;
attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
if (!attr)
return -EMSGSIZE;
if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
goto nla_put_failure;
if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
goto nla_put_failure;
if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->addr.flags))
goto nla_put_failure;
if (entry->addr.ifindex &&
nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->addr.ifindex))
goto nla_put_failure;
if (addr->family == AF_INET &&
nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
addr->addr.s_addr))
goto nla_put_failure;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
else if (addr->family == AF_INET6 &&
nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
goto nla_put_failure;
#endif
nla_nest_end(skb, attr);
return 0;
nla_put_failure:
nla_nest_cancel(skb, attr);
return -EMSGSIZE;
}
static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
{
struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
struct mptcp_pm_addr_entry addr, *entry;
struct sk_buff *msg;
void *reply;
int ret;
ret = mptcp_pm_parse_addr(attr, info, false, &addr);
if (ret < 0)
return ret;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
info->genlhdr->cmd);
if (!reply) {
GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
ret = -EMSGSIZE;
goto fail;
}
spin_lock_bh(&pernet->lock);
entry = __lookup_addr_by_id(pernet, addr.addr.id);
if (!entry) {
GENL_SET_ERR_MSG(info, "address not found");
ret = -EINVAL;
goto unlock_fail;
}
ret = mptcp_nl_fill_addr(msg, entry);
if (ret)
goto unlock_fail;
genlmsg_end(msg, reply);
ret = genlmsg_reply(msg, info);
spin_unlock_bh(&pernet->lock);
return ret;
unlock_fail:
spin_unlock_bh(&pernet->lock);
fail:
nlmsg_free(msg);
return ret;
}
static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
struct netlink_callback *cb)
{
struct net *net = sock_net(msg->sk);
struct mptcp_pm_addr_entry *entry;
struct pm_nl_pernet *pernet;
int id = cb->args[0];
void *hdr;
pernet = net_generic(net, pm_nl_pernet_id);
spin_lock_bh(&pernet->lock);
list_for_each_entry(entry, &pernet->local_addr_list, list) {
if (entry->addr.id <= id)
continue;
hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, &mptcp_genl_family,
NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
if (!hdr)
break;
if (mptcp_nl_fill_addr(msg, entry) < 0) {
genlmsg_cancel(msg, hdr);
break;
}
id = entry->addr.id;
genlmsg_end(msg, hdr);
}
spin_unlock_bh(&pernet->lock);
cb->args[0] = id;
return msg->len;
}
static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
{
struct nlattr *attr = info->attrs[id];
if (!attr)
return 0;
*limit = nla_get_u32(attr);
if (*limit > MPTCP_PM_ADDR_MAX) {
GENL_SET_ERR_MSG(info, "limit greater than maximum");
return -EINVAL;
}
return 0;
}
static int
mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
{
struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
unsigned int rcv_addrs, subflows;
int ret;
spin_lock_bh(&pernet->lock);
rcv_addrs = pernet->add_addr_accept_max;
ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
if (ret)
goto unlock;
subflows = pernet->subflows_max;
ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
if (ret)
goto unlock;
WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
WRITE_ONCE(pernet->subflows_max, subflows);
unlock:
spin_unlock_bh(&pernet->lock);
return ret;
}
static int
mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
{
struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
struct sk_buff *msg;
void *reply;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
MPTCP_PM_CMD_GET_LIMITS);
if (!reply)
goto fail;
if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
READ_ONCE(pernet->add_addr_accept_max)))
goto fail;
if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
READ_ONCE(pernet->subflows_max)))
goto fail;
genlmsg_end(msg, reply);
return genlmsg_reply(msg, info);
fail:
GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
nlmsg_free(msg);
return -EMSGSIZE;
}
static const struct genl_small_ops mptcp_pm_ops[] = {
{
.cmd = MPTCP_PM_CMD_ADD_ADDR,
.doit = mptcp_nl_cmd_add_addr,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = MPTCP_PM_CMD_DEL_ADDR,
.doit = mptcp_nl_cmd_del_addr,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = MPTCP_PM_CMD_FLUSH_ADDRS,
.doit = mptcp_nl_cmd_flush_addrs,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = MPTCP_PM_CMD_GET_ADDR,
.doit = mptcp_nl_cmd_get_addr,
.dumpit = mptcp_nl_cmd_dump_addrs,
},
{
.cmd = MPTCP_PM_CMD_SET_LIMITS,
.doit = mptcp_nl_cmd_set_limits,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = MPTCP_PM_CMD_GET_LIMITS,
.doit = mptcp_nl_cmd_get_limits,
},
};
static struct genl_family mptcp_genl_family __ro_after_init = {
.name = MPTCP_PM_NAME,
.version = MPTCP_PM_VER,
.maxattr = MPTCP_PM_ATTR_MAX,
.policy = mptcp_pm_policy,
.netnsok = true,
.module = THIS_MODULE,
.small_ops = mptcp_pm_ops,
.n_small_ops = ARRAY_SIZE(mptcp_pm_ops),
.mcgrps = mptcp_pm_mcgrps,
.n_mcgrps = ARRAY_SIZE(mptcp_pm_mcgrps),
};
static int __net_init pm_nl_init_net(struct net *net)
{
struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
__reset_counters(pernet);
pernet->next_id = 1;
spin_lock_init(&pernet->lock);
return 0;
}
static void __net_exit pm_nl_exit_net(struct list_head *net_list)
{
struct net *net;
list_for_each_entry(net, net_list, exit_list) {
struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
/* net is removed from namespace list, can't race with
* other modifiers
*/
__flush_addrs(net, &pernet->local_addr_list);
}
}
static struct pernet_operations mptcp_pm_pernet_ops = {
.init = pm_nl_init_net,
.exit_batch = pm_nl_exit_net,
.id = &pm_nl_pernet_id,
.size = sizeof(struct pm_nl_pernet),
};
void __init mptcp_pm_nl_init(void)
{
if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
panic("Failed to register MPTCP PM pernet subsystem.\n");
if (genl_register_family(&mptcp_genl_family))
panic("Failed to register MPTCP PM netlink family\n");
}