diff options
author | Craig Gallek <kraig@google.com> | 2015-06-15 11:26:18 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2015-06-15 19:49:22 -0700 |
commit | eb4cb008529ca08e0d8c0fa54e8f739520197a65 (patch) | |
tree | e7f6c004e7e540abba090a618240c6426d2df956 /net | |
parent | 916035ddd3f453a9152db8755dc8a1f53505444c (diff) | |
download | linux-eb4cb008529ca08e0d8c0fa54e8f739520197a65.tar.bz2 |
sock_diag: define destruction multicast groups
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 <kraig@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/core/sock.c | 11 | ||||
-rw-r--r-- | net/core/sock_diag.c | 85 |
2 files changed, 95 insertions, 1 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 7063c329c1b6..1e1fe9a68d83 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -131,6 +131,7 @@ #include <linux/ipsec.h> #include <net/cls_cgroup.h> #include <net/netprio_cgroup.h> +#include <linux/sock_diag.h> #include <linux/filter.h> @@ -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 74dddf84adcd..d79866c5f8bc 100644 --- a/net/core/sock_diag.c +++ b/net/core/sock_diag.c @@ -5,6 +5,9 @@ #include <net/net_namespace.h> #include <linux/module.h> #include <net/sock.h> +#include <linux/kernel.h> +#include <linux/tcp.h> +#include <linux/workqueue.h> #include <linux/inet_diag.h> #include <linux/sock_diag.h> @@ -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); |