forked from mirrors/linux
2aa1f7a1f4
The current proc connector code has the foll. bugs - if there are more than one listeners for the proc connector messages, and one of them deregisters for listening using PROC_CN_MCAST_IGNORE, they will still get all proc connector messages, as long as there is another listener. Another issue is if one client calls PROC_CN_MCAST_LISTEN, and another one calls PROC_CN_MCAST_IGNORE, then both will end up not getting any messages. This patch adds filtering and drops packet if client has sent PROC_CN_MCAST_IGNORE. This data is stored in the client socket's sk_user_data. In addition, we only increment or decrement proc_event_num_listeners once per client. This fixes the above issues. cn_release is the release function added for NETLINK_CONNECTOR. It uses the newly added netlink_release function added to netlink_sock. It will free sk_user_data. Signed-off-by: Anjali Kulkarni <anjali.k.kulkarni@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
141 lines
4.1 KiB
C
141 lines
4.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* connector.h
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*
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* 2004-2005 Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
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* All rights reserved.
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*/
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#ifndef __CONNECTOR_H
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#define __CONNECTOR_H
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#include <linux/refcount.h>
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#include <linux/list.h>
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#include <linux/workqueue.h>
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#include <net/sock.h>
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#include <uapi/linux/connector.h>
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#define CN_CBQ_NAMELEN 32
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struct cn_queue_dev {
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atomic_t refcnt;
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unsigned char name[CN_CBQ_NAMELEN];
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struct list_head queue_list;
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spinlock_t queue_lock;
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struct sock *nls;
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};
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struct cn_callback_id {
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unsigned char name[CN_CBQ_NAMELEN];
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struct cb_id id;
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};
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struct cn_callback_entry {
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struct list_head callback_entry;
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refcount_t refcnt;
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struct cn_queue_dev *pdev;
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struct cn_callback_id id;
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void (*callback) (struct cn_msg *, struct netlink_skb_parms *);
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u32 seq, group;
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};
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struct cn_dev {
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struct cb_id id;
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u32 seq, groups;
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struct sock *nls;
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struct cn_queue_dev *cbdev;
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};
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/**
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* cn_add_callback() - Registers new callback with connector core.
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*
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* @id: unique connector's user identifier.
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* It must be registered in connector.h for legal
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* in-kernel users.
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* @name: connector's callback symbolic name.
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* @callback: connector's callback.
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* parameters are %cn_msg and the sender's credentials
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*/
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int cn_add_callback(const struct cb_id *id, const char *name,
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void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
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/**
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* cn_del_callback() - Unregisters new callback with connector core.
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*
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* @id: unique connector's user identifier.
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*/
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void cn_del_callback(const struct cb_id *id);
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/**
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* cn_netlink_send_mult - Sends message to the specified groups.
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*
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* @msg: message header(with attached data).
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* @len: Number of @msg to be sent.
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* @portid: destination port.
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* If non-zero the message will be sent to the given port,
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* which should be set to the original sender.
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* @group: destination group.
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* If @portid and @group is zero, then appropriate group will
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* be searched through all registered connector users, and
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* message will be delivered to the group which was created
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* for user with the same ID as in @msg.
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* If @group is not zero, then message will be delivered
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* to the specified group.
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* @gfp_mask: GFP mask.
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* @filter: Filter function to be used at netlink layer.
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* @filter_data:Filter data to be supplied to the filter function
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*
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* It can be safely called from softirq context, but may silently
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* fail under strong memory pressure.
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*
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* If there are no listeners for given group %-ESRCH can be returned.
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*/
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int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid,
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u32 group, gfp_t gfp_mask,
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int (*filter)(struct sock *dsk, struct sk_buff *skb,
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void *data),
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void *filter_data);
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/**
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* cn_netlink_send - Sends message to the specified groups.
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*
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* @msg: message header(with attached data).
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* @portid: destination port.
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* If non-zero the message will be sent to the given port,
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* which should be set to the original sender.
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* @group: destination group.
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* If @portid and @group is zero, then appropriate group will
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* be searched through all registered connector users, and
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* message will be delivered to the group which was created
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* for user with the same ID as in @msg.
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* If @group is not zero, then message will be delivered
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* to the specified group.
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* @gfp_mask: GFP mask.
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*
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* It can be safely called from softirq context, but may silently
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* fail under strong memory pressure.
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*
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* If there are no listeners for given group %-ESRCH can be returned.
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*/
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int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask);
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int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
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const struct cb_id *id,
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void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
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void cn_queue_del_callback(struct cn_queue_dev *dev, const struct cb_id *id);
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void cn_queue_release_callback(struct cn_callback_entry *);
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struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *);
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void cn_queue_free_dev(struct cn_queue_dev *dev);
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int cn_cb_equal(const struct cb_id *, const struct cb_id *);
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#endif /* __CONNECTOR_H */
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