--- /dev/null
+// 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");
+}
projects / users / hch / configfs.git / commitdiff