mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-13 03:36:48 +07:00
a3ea269b8b
In order to open up the possibility to internally transform a BPF program
into an alternative and possibly non-trivial reversible representation, we
need to keep the original BPF program around, so that it can be passed back
to user space w/o the need of a complex decoder.
The reason for that use case resides in commit a8fc927780
("sk-filter:
Add ability to get socket filter program (v2)"), that is, the ability
to retrieve the currently attached BPF filter from a given socket used
mainly by the checkpoint-restore project, for example.
Therefore, we add two helpers sk_{store,release}_orig_filter for taking
care of that. In the sk_unattached_filter_create() case, there's no such
possibility/requirement to retrieve a loaded BPF program. Therefore, we
can spare us the work in that case.
This approach will simplify and slightly speed up both, sk_get_filter()
and sock_diag_put_filterinfo() handlers as we won't need to successively
decode filters anymore through sk_decode_filter(). As we still need
sk_decode_filter() later on, we're keeping it around.
Joint work with Alexei Starovoitov.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
232 lines
5.5 KiB
C
232 lines
5.5 KiB
C
#include <linux/mutex.h>
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#include <linux/socket.h>
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#include <linux/skbuff.h>
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#include <net/netlink.h>
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#include <net/net_namespace.h>
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#include <linux/module.h>
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#include <net/sock.h>
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#include <linux/inet_diag.h>
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#include <linux/sock_diag.h>
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static const struct sock_diag_handler *sock_diag_handlers[AF_MAX];
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static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
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static DEFINE_MUTEX(sock_diag_table_mutex);
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int sock_diag_check_cookie(void *sk, __u32 *cookie)
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{
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if ((cookie[0] != INET_DIAG_NOCOOKIE ||
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cookie[1] != INET_DIAG_NOCOOKIE) &&
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((u32)(unsigned long)sk != cookie[0] ||
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(u32)((((unsigned long)sk) >> 31) >> 1) != cookie[1]))
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return -ESTALE;
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else
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return 0;
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}
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EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
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void sock_diag_save_cookie(void *sk, __u32 *cookie)
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{
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cookie[0] = (u32)(unsigned long)sk;
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cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1);
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}
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EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
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int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
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{
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u32 mem[SK_MEMINFO_VARS];
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mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
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mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
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mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
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mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
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mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
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mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
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mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
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mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
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return nla_put(skb, attrtype, sizeof(mem), &mem);
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}
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EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
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int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk,
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struct sk_buff *skb, int attrtype)
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{
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struct sock_fprog_kern *fprog;
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struct sk_filter *filter;
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struct nlattr *attr;
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unsigned int flen;
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int err = 0;
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if (!ns_capable(user_ns, CAP_NET_ADMIN)) {
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nla_reserve(skb, attrtype, 0);
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return 0;
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}
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rcu_read_lock();
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filter = rcu_dereference(sk->sk_filter);
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if (!filter)
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goto out;
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fprog = filter->orig_prog;
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flen = sk_filter_proglen(fprog);
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attr = nla_reserve(skb, attrtype, flen);
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if (attr == NULL) {
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err = -EMSGSIZE;
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goto out;
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}
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memcpy(nla_data(attr), fprog->filter, flen);
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out:
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rcu_read_unlock();
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return err;
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}
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EXPORT_SYMBOL(sock_diag_put_filterinfo);
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void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
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{
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mutex_lock(&sock_diag_table_mutex);
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inet_rcv_compat = fn;
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mutex_unlock(&sock_diag_table_mutex);
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}
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EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
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void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
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{
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mutex_lock(&sock_diag_table_mutex);
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inet_rcv_compat = NULL;
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mutex_unlock(&sock_diag_table_mutex);
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}
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EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
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int sock_diag_register(const struct sock_diag_handler *hndl)
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{
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int err = 0;
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if (hndl->family >= AF_MAX)
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return -EINVAL;
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mutex_lock(&sock_diag_table_mutex);
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if (sock_diag_handlers[hndl->family])
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err = -EBUSY;
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else
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sock_diag_handlers[hndl->family] = hndl;
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mutex_unlock(&sock_diag_table_mutex);
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return err;
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}
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EXPORT_SYMBOL_GPL(sock_diag_register);
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void sock_diag_unregister(const struct sock_diag_handler *hnld)
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{
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int family = hnld->family;
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if (family >= AF_MAX)
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return;
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mutex_lock(&sock_diag_table_mutex);
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BUG_ON(sock_diag_handlers[family] != hnld);
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sock_diag_handlers[family] = NULL;
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mutex_unlock(&sock_diag_table_mutex);
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}
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EXPORT_SYMBOL_GPL(sock_diag_unregister);
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static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
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{
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int err;
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struct sock_diag_req *req = nlmsg_data(nlh);
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const struct sock_diag_handler *hndl;
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if (nlmsg_len(nlh) < sizeof(*req))
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return -EINVAL;
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if (req->sdiag_family >= AF_MAX)
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return -EINVAL;
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if (sock_diag_handlers[req->sdiag_family] == NULL)
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request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
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NETLINK_SOCK_DIAG, req->sdiag_family);
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mutex_lock(&sock_diag_table_mutex);
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hndl = sock_diag_handlers[req->sdiag_family];
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if (hndl == NULL)
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err = -ENOENT;
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else
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err = hndl->dump(skb, nlh);
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mutex_unlock(&sock_diag_table_mutex);
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return err;
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}
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static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
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{
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int ret;
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switch (nlh->nlmsg_type) {
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case TCPDIAG_GETSOCK:
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case DCCPDIAG_GETSOCK:
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if (inet_rcv_compat == NULL)
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request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
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NETLINK_SOCK_DIAG, AF_INET);
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mutex_lock(&sock_diag_table_mutex);
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if (inet_rcv_compat != NULL)
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ret = inet_rcv_compat(skb, nlh);
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else
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ret = -EOPNOTSUPP;
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mutex_unlock(&sock_diag_table_mutex);
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return ret;
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case SOCK_DIAG_BY_FAMILY:
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return __sock_diag_rcv_msg(skb, nlh);
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default:
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return -EINVAL;
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}
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}
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static DEFINE_MUTEX(sock_diag_mutex);
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static void sock_diag_rcv(struct sk_buff *skb)
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{
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mutex_lock(&sock_diag_mutex);
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netlink_rcv_skb(skb, &sock_diag_rcv_msg);
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mutex_unlock(&sock_diag_mutex);
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}
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static int __net_init diag_net_init(struct net *net)
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{
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struct netlink_kernel_cfg cfg = {
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.input = sock_diag_rcv,
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};
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net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
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return net->diag_nlsk == NULL ? -ENOMEM : 0;
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}
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static void __net_exit diag_net_exit(struct net *net)
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{
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netlink_kernel_release(net->diag_nlsk);
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net->diag_nlsk = NULL;
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}
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static struct pernet_operations diag_net_ops = {
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.init = diag_net_init,
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.exit = diag_net_exit,
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};
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static int __init sock_diag_init(void)
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{
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return register_pernet_subsys(&diag_net_ops);
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}
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static void __exit sock_diag_exit(void)
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{
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unregister_pernet_subsys(&diag_net_ops);
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}
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module_init(sock_diag_init);
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module_exit(sock_diag_exit);
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);
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