From mboxrd@z Thu Jan 1 00:00:00 1970 From: Craig Gallek Subject: [PATCH net-next 1/3] sock_diag: define destruction multicast groups Date: Mon, 15 Jun 2015 11:26:18 -0400 Message-ID: <1434381980-20588-2-git-send-email-kraig@google.com> References: <1434381980-20588-1-git-send-email-kraig@google.com> Cc: edumazet@google.com, mleitner@redhat.com, stephen@networkplumber.org, davem@davemloft.net, ebiederm@xmission.net, tgraf@suug.ch, xemul@openvz.org, Craig Gallek To: netdev@vger.kernel.org Return-path: Received: from mail-yh0-f51.google.com ([209.85.213.51]:36807 "EHLO mail-yh0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754166AbbFOP1U (ORCPT ); Mon, 15 Jun 2015 11:27:20 -0400 Received: by yhan67 with SMTP id n67so45022998yha.3 for ; Mon, 15 Jun 2015 08:27:19 -0700 (PDT) In-Reply-To: <1434381980-20588-1-git-send-email-kraig@google.com> Sender: netdev-owner@vger.kernel.org List-ID: These groups will contain socket-destruction events for AF_INET/AF_INET6, IPPROTO_TCP/IPPROTO_UDP. Near the end of socket destruction, a check for listeners is performed. In the presence of a listener, rather than completely cleanup the socket, a unit of work will be added to a private work queue which will first broadcast information about the socket and then finish the cleanup operation. Signed-off-by: Craig Gallek --- include/linux/sock_diag.h | 42 +++++++++++++++++++++ include/net/sock.h | 1 + include/uapi/linux/sock_diag.h | 10 +++++ net/core/sock.c | 11 +++++- net/core/sock_diag.c | 85 ++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 148 insertions(+), 1 deletion(-) diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h index 083ac38..fddebc6 100644 --- a/include/linux/sock_diag.h +++ b/include/linux/sock_diag.h @@ -1,7 +1,10 @@ #ifndef __SOCK_DIAG_H__ #define __SOCK_DIAG_H__ +#include #include +#include +#include #include struct sk_buff; @@ -11,6 +14,7 @@ struct sock; struct sock_diag_handler { __u8 family; int (*dump)(struct sk_buff *skb, struct nlmsghdr *nlh); + int (*get_info)(struct sk_buff *skb, struct sock *sk); }; int sock_diag_register(const struct sock_diag_handler *h); @@ -26,4 +30,42 @@ int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attr); int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk, struct sk_buff *skb, int attrtype); +static inline +enum sknetlink_groups sock_diag_destroy_group(const struct sock *sk) +{ + switch (sk->sk_family) { + case AF_INET: + switch (sk->sk_protocol) { + case IPPROTO_TCP: + return SKNLGRP_INET_TCP_DESTROY; + case IPPROTO_UDP: + return SKNLGRP_INET_UDP_DESTROY; + default: + return SKNLGRP_NONE; + } + case AF_INET6: + switch (sk->sk_protocol) { + case IPPROTO_TCP: + return SKNLGRP_INET6_TCP_DESTROY; + case IPPROTO_UDP: + return SKNLGRP_INET6_UDP_DESTROY; + default: + return SKNLGRP_NONE; + } + default: + return SKNLGRP_NONE; + } +} + +static inline +bool sock_diag_has_destroy_listeners(const struct sock *sk) +{ + const struct net *n = sock_net(sk); + const enum sknetlink_groups group = sock_diag_destroy_group(sk); + + return group != SKNLGRP_NONE && n->diag_nlsk && + netlink_has_listeners(n->diag_nlsk, group); +} +void sock_diag_broadcast_destroy(struct sock *sk); + #endif diff --git a/include/net/sock.h b/include/net/sock.h index 26c1c31..3e82586 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1518,6 +1518,7 @@ static inline void unlock_sock_fast(struct sock *sk, bool slow) struct sock *sk_alloc(struct net *net, int family, gfp_t priority, struct proto *prot, int kern); void sk_free(struct sock *sk); +void sk_destruct(struct sock *sk); struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority); struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force, diff --git a/include/uapi/linux/sock_diag.h b/include/uapi/linux/sock_diag.h index b00e29e..49230d3 100644 --- a/include/uapi/linux/sock_diag.h +++ b/include/uapi/linux/sock_diag.h @@ -23,4 +23,14 @@ enum { SK_MEMINFO_VARS, }; +enum sknetlink_groups { + SKNLGRP_NONE, + SKNLGRP_INET_TCP_DESTROY, + SKNLGRP_INET_UDP_DESTROY, + SKNLGRP_INET6_TCP_DESTROY, + SKNLGRP_INET6_UDP_DESTROY, + __SKNLGRP_MAX, +}; +#define SKNLGRP_MAX (__SKNLGRP_MAX - 1) + #endif /* _UAPI__SOCK_DIAG_H__ */ diff --git a/net/core/sock.c b/net/core/sock.c index 7063c32..1e1fe9a 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -131,6 +131,7 @@ #include #include #include +#include #include @@ -1423,7 +1424,7 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority, } EXPORT_SYMBOL(sk_alloc); -static void __sk_free(struct sock *sk) +void sk_destruct(struct sock *sk) { struct sk_filter *filter; @@ -1451,6 +1452,14 @@ static void __sk_free(struct sock *sk) sk_prot_free(sk->sk_prot_creator, sk); } +static void __sk_free(struct sock *sk) +{ + if (unlikely(sock_diag_has_destroy_listeners(sk))) + sock_diag_broadcast_destroy(sk); + else + sk_destruct(sk); +} + void sk_free(struct sock *sk) { /* diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c index 74dddf8..d79866c 100644 --- a/net/core/sock_diag.c +++ b/net/core/sock_diag.c @@ -5,6 +5,9 @@ #include #include #include +#include +#include +#include #include #include @@ -12,6 +15,7 @@ static const struct sock_diag_handler *sock_diag_handlers[AF_MAX]; static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh); static DEFINE_MUTEX(sock_diag_table_mutex); +static struct workqueue_struct *broadcast_wq; static u64 sock_gen_cookie(struct sock *sk) { @@ -101,6 +105,62 @@ out: } EXPORT_SYMBOL(sock_diag_put_filterinfo); +struct broadcast_sk { + struct sock *sk; + struct work_struct work; +}; + +static size_t sock_diag_nlmsg_size(void) +{ + return NLMSG_ALIGN(sizeof(struct inet_diag_msg) + + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */ + + nla_total_size(sizeof(struct tcp_info))); /* INET_DIAG_INFO */ +} + +static void sock_diag_broadcast_destroy_work(struct work_struct *work) +{ + struct broadcast_sk *bsk = + container_of(work, struct broadcast_sk, work); + struct sock *sk = bsk->sk; + const struct sock_diag_handler *hndl; + struct sk_buff *skb; + const enum sknetlink_groups group = sock_diag_destroy_group(sk); + int err = -1; + + WARN_ON(group == SKNLGRP_NONE); + + skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL); + if (!skb) + goto out; + + mutex_lock(&sock_diag_table_mutex); + hndl = sock_diag_handlers[sk->sk_family]; + if (hndl && hndl->get_info) + err = hndl->get_info(skb, sk); + mutex_unlock(&sock_diag_table_mutex); + + if (!err) + nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group, + GFP_KERNEL); + else + kfree_skb(skb); +out: + sk_destruct(sk); + kfree(bsk); +} + +void sock_diag_broadcast_destroy(struct sock *sk) +{ + /* Note, this function is often called from an interrupt context. */ + struct broadcast_sk *bsk = + kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC); + if (!bsk) + return sk_destruct(sk); + bsk->sk = sk; + INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work); + queue_work(broadcast_wq, &bsk->work); +} + void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) { mutex_lock(&sock_diag_table_mutex); @@ -211,10 +271,32 @@ static void sock_diag_rcv(struct sk_buff *skb) mutex_unlock(&sock_diag_mutex); } +static int sock_diag_bind(struct net *net, int group) +{ + switch (group) { + case SKNLGRP_INET_TCP_DESTROY: + case SKNLGRP_INET_UDP_DESTROY: + if (!sock_diag_handlers[AF_INET]) + request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, + NETLINK_SOCK_DIAG, AF_INET); + break; + case SKNLGRP_INET6_TCP_DESTROY: + case SKNLGRP_INET6_UDP_DESTROY: + if (!sock_diag_handlers[AF_INET6]) + request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, + NETLINK_SOCK_DIAG, AF_INET); + break; + } + return 0; +} + static int __net_init diag_net_init(struct net *net) { struct netlink_kernel_cfg cfg = { + .groups = SKNLGRP_MAX, .input = sock_diag_rcv, + .bind = sock_diag_bind, + .flags = NL_CFG_F_NONROOT_RECV, }; net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg); @@ -234,12 +316,15 @@ static struct pernet_operations diag_net_ops = { static int __init sock_diag_init(void) { + broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0); + BUG_ON(!broadcast_wq); return register_pernet_subsys(&diag_net_ops); } static void __exit sock_diag_exit(void) { unregister_pernet_subsys(&diag_net_ops); + destroy_workqueue(broadcast_wq); } module_init(sock_diag_init); -- 2.2.0.rc0.207.ga3a616c