diff options
Diffstat (limited to 'net/mptcp/pm_netlink.c')
| -rw-r--r-- | net/mptcp/pm_netlink.c | 857 |
1 files changed, 857 insertions, 0 deletions
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c new file mode 100644 index 000000000000..a0ce7f324499 --- /dev/null +++ b/net/mptcp/pm_netlink.c @@ -0,0 +1,857 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Multipath TCP + * + * Copyright (c) 2020, Red Hat, Inc. + */ + +#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" + +/* forward declaration */ +static struct genl_family mptcp_genl_family; + +static int pm_nl_pernet_id; + +struct mptcp_pm_addr_entry { + struct list_head list; + unsigned int flags; + int ifindex; + struct mptcp_addr_info addr; + struct rcu_head rcu; +}; + +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 + +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 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(); + spin_lock_bh(&msk->join_list_lock); + list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { + if (!(entry->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) && + !lookup_subflow_by_saddr(&msk->join_list, &entry->addr)) { + ret = entry; + break; + } + } + spin_unlock_bh(&msk->join_list_lock); + 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->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 void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) +{ + struct sock *sk = (struct sock *)msk; + struct mptcp_pm_addr_entry *local; + struct mptcp_addr_info remote; + struct pm_nl_pernet *pernet; + + pernet = net_generic(sock_net((struct sock *)msk), 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) { + msk->pm.add_addr_signaled++; + mptcp_pm_announce_addr(msk, &local->addr); + } 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->ifindex, + &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; + + 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; + memset(&local, 0, sizeof(local)); + local.family = remote.family; + + spin_unlock_bh(&msk->pm.lock); + __mptcp_subflow_connect((struct sock *)msk, 0, &local, &remote); + spin_lock_bh(&msk->pm.lock); +} + +static bool address_use_port(struct mptcp_pm_addr_entry *entry) +{ + return (entry->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->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) + pernet->add_addr_signal_max++; + if (entry->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 *)msk, &skc_local); + if (addresses_equal(&msk_local, &skc_local, false)) + 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_KERNEL); + if (!entry) + return -ENOMEM; + + entry->flags = 0; + entry->addr = skc_local; + 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] = { .type = NLA_EXACT_LEN, + .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]) + entry->ifindex = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]); + + 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->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 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"); + ret = -EINVAL; + goto out; + } + if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) + pernet->add_addr_signal_max--; + if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) + pernet->local_addr_max--; + + pernet->addrs--; + list_del_rcu(&entry->list); + kfree_rcu(entry, rcu); +out: + spin_unlock_bh(&pernet->lock); + return ret; +} + +static void __flush_addrs(struct pm_nl_pernet *pernet) +{ + while (!list_empty(&pernet->local_addr_list)) { + struct mptcp_pm_addr_entry *cur; + + cur = list_entry(pernet->local_addr_list.next, + struct mptcp_pm_addr_entry, list); + 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); + + spin_lock_bh(&pernet->lock); + __flush_addrs(pernet); + __reset_counters(pernet); + spin_unlock_bh(&pernet->lock); + 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->flags)) + goto nla_put_failure; + if (entry->ifindex && + nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex)) + goto nla_put_failure; + + if (addr->family == AF_INET) + nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4, + addr->addr.s_addr); +#if IS_ENABLED(CONFIG_MPTCP_IPV6) + else if (addr->family == AF_INET6) + nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6); +#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 struct genl_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, + .ops = mptcp_pm_ops, + .n_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) { + /* net is removed from namespace list, can't race with + * other modifiers + */ + __flush_addrs(net_generic(net, pm_nl_pernet_id)); + } +} + +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 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"); +} |