Hi Mat, Mat Martineau 于2020年12月4日周五 上午9:36写道： > > On Mon, 30 Nov 2020, Geliang Tang wrote: > > > This patch created a listening socket when an address with a port-number > > is added by PM netlink. Then binded the new port to the socket, and > > listened for the connection. > > > > Signed-off-by: Geliang Tang > > --- > > net/mptcp/pm_netlink.c | 58 ++++++++++++++++++++++++++++++++++++++++++ > > net/mptcp/protocol.c | 2 +- > > net/mptcp/protocol.h | 3 +++ > > net/mptcp/subflow.c | 4 +-- > > 4 files changed, 64 insertions(+), 3 deletions(-) > > > > diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c > > index 5151cfcd6962..c296927bf167 100644 > > --- a/net/mptcp/pm_netlink.c > > +++ b/net/mptcp/pm_netlink.c > > @@ -26,6 +26,7 @@ struct mptcp_pm_addr_entry { > > struct list_head list; > > struct mptcp_addr_info addr; > > struct rcu_head rcu; > > + struct socket *lsk; > > Two things to fix up: > > Non-zero lsk is not released everywhere mptcp_pm_addr_entry structs are > freed. I'll add the following releasing code in mptcp_nl_cmd_del_addr and __flush_addrs in v8: if (entry->lsk) sock_release(entry->lsk); But as I mentioned on my last letter, there is a deadlock warning when releasing this listening socket. > > lsk is not initialized in mptcp_pm_nl_get_local_id() > I'll add the following code in mptcp_pm_nl_get_local_id in v8: entry->lsk = NULL; > > }; > > > > struct mptcp_pm_add_entry { > > @@ -732,6 +733,53 @@ 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_pm_nl_create_listen_socket(struct sock *sk, > > + struct mptcp_pm_addr_entry *entry) > > +{ > > + struct sockaddr_storage addr; > > + struct mptcp_sock *msk; > > + struct socket *ssock; > > + int backlog = 20; > > Any comment on the choice of '20' here? Could it be too small for a high > connection rate, or worth a sysctl? I'll change it to '1024' in v8, since on the textbook UNPv3, 1024 is always used as the 2nd argument to listen(): int backlog = 1024; -Geliang > > Thanks, > > Mat > > > + int err; > > + > > + err = sock_create_kern(sock_net(sk), entry->addr.family, > > + SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk); > > + if (err) > > + return err; > > + > > + msk = mptcp_sk(entry->lsk->sk); > > + if (!msk) { > > + err = -EINVAL; > > + goto out; > > + } > > + > > + ssock = __mptcp_nmpc_socket(msk); > > + if (!ssock) { > > + err = -EINVAL; > > + goto out; > > + } > > + > > + mptcp_info2sockaddr(&entry->addr, &addr); > > + err = kernel_bind(ssock, (struct sockaddr *)&addr, > > + sizeof(struct sockaddr_in)); > > + if (err) { > > + pr_warn("kernel_bind error, err=%d", err); > > + goto out; > > + } > > + > > + err = kernel_listen(ssock, backlog); > > + if (err) { > > + pr_warn("kernel_listen error, err=%d", err); > > + goto out; > > + } > > + > > + return 0; > > + > > +out: > > + sock_release(entry->lsk); > > + return err; > > +} > > + > > static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info) > > { > > struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; > > @@ -750,9 +798,19 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info) > > } > > > > *entry = addr; > > + if (entry->addr.port) { > > + ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry); > > + if (ret) { > > + GENL_SET_ERR_MSG(info, "create listen socket error"); > > + kfree(entry); > > + return ret; > > + } > > + } > > ret = mptcp_pm_nl_append_new_local_addr(pernet, entry); > > if (ret < 0) { > > GENL_SET_ERR_MSG(info, "too many addresses or duplicate one"); > > + if (entry->lsk) > > + sock_release(entry->lsk); > > kfree(entry); > > return ret; > > } > > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > > index 4c36969873b9..5e464dfc0f6f 100644 > > --- a/net/mptcp/protocol.c > > +++ b/net/mptcp/protocol.c > > @@ -49,7 +49,7 @@ static void __mptcp_check_send_data_fin(struct sock *sk); > > * completed yet or has failed, return the subflow socket. > > * Otherwise return NULL. > > */ > > -static struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk) > > +struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk) > > { > > if (!msk->subflow || READ_ONCE(msk->can_ack)) > > return NULL; > > diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h > > index 9d8f01aac91c..ec179f3a6b4b 100644 > > --- a/net/mptcp/protocol.h > > +++ b/net/mptcp/protocol.h > > @@ -466,11 +466,14 @@ void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how); > > void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, > > struct mptcp_subflow_context *subflow); > > void mptcp_subflow_reset(struct sock *ssk); > > +struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk); > > > > /* called with sk socket lock held */ > > int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, > > const struct mptcp_addr_info *remote); > > int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock); > > +void mptcp_info2sockaddr(const struct mptcp_addr_info *info, > > + struct sockaddr_storage *addr); > > > > static inline void mptcp_subflow_tcp_fallback(struct sock *sk, > > struct mptcp_subflow_context *ctx) > > diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c > > index 96c585f003f8..43cc5e2c3234 100644 > > --- a/net/mptcp/subflow.c > > +++ b/net/mptcp/subflow.c > > @@ -1035,8 +1035,8 @@ void mptcpv6_handle_mapped(struct sock *sk, bool mapped) > > } > > #endif > > > > -static void mptcp_info2sockaddr(const struct mptcp_addr_info *info, > > - struct sockaddr_storage *addr) > > +void mptcp_info2sockaddr(const struct mptcp_addr_info *info, > > + struct sockaddr_storage *addr) > > { > > memset(addr, 0, sizeof(*addr)); > > addr->ss_family = info->family; > > -- > > 2.26.2 > > -- > Mat Martineau > Intel