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130 lines
3.7 KiB
130 lines
3.7 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Linux WiMAX |
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* Mappping of generic netlink family IDs to net devices |
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* |
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* Copyright (C) 2005-2006 Intel Corporation <[email protected]> |
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* Inaky Perez-Gonzalez <[email protected]> |
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* |
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* We assign a single generic netlink family ID to each device (to |
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* simplify lookup). |
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* |
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* We need a way to map family ID to a wimax_dev pointer. |
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* |
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* The idea is to use a very simple lookup. Using a netlink attribute |
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* with (for example) the interface name implies a heavier search over |
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* all the network devices; seemed kind of a waste given that we know |
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* we are looking for a WiMAX device and that most systems will have |
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* just a single WiMAX adapter. |
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* |
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* We put all the WiMAX devices in the system in a linked list and |
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* match the generic link family ID against the list. |
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* |
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* By using a linked list, the case of a single adapter in the system |
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* becomes (almost) no overhead, while still working for many more. If |
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* it ever goes beyond two, I'll be surprised. |
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*/ |
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#include <linux/device.h> |
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#include <net/genetlink.h> |
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#include <linux/netdevice.h> |
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#include <linux/list.h> |
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#include <linux/wimax.h> |
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#include "wimax-internal.h" |
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#define D_SUBMODULE id_table |
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#include "debug-levels.h" |
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static DEFINE_SPINLOCK(wimax_id_table_lock); |
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static struct list_head wimax_id_table = LIST_HEAD_INIT(wimax_id_table); |
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/* |
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* wimax_id_table_add - add a gennetlink familiy ID / wimax_dev mapping |
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* |
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* @wimax_dev: WiMAX device descriptor to associate to the Generic |
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* Netlink family ID. |
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* |
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* Look for an empty spot in the ID table; if none found, double the |
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* table's size and get the first spot. |
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*/ |
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void wimax_id_table_add(struct wimax_dev *wimax_dev) |
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{ |
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d_fnstart(3, NULL, "(wimax_dev %p)\n", wimax_dev); |
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spin_lock(&wimax_id_table_lock); |
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list_add(&wimax_dev->id_table_node, &wimax_id_table); |
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spin_unlock(&wimax_id_table_lock); |
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d_fnend(3, NULL, "(wimax_dev %p)\n", wimax_dev); |
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} |
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/* |
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* wimax_get_netdev_by_info - lookup a wimax_dev from the gennetlink info |
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* |
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* The generic netlink family ID has been filled out in the |
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* nlmsghdr->nlmsg_type field, so we pull it from there, look it up in |
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* the mapping table and reference the wimax_dev. |
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* |
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* When done, the reference should be dropped with |
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* 'dev_put(wimax_dev->net_dev)'. |
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*/ |
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struct wimax_dev *wimax_dev_get_by_genl_info( |
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struct genl_info *info, int ifindex) |
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{ |
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struct wimax_dev *wimax_dev = NULL; |
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d_fnstart(3, NULL, "(info %p ifindex %d)\n", info, ifindex); |
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spin_lock(&wimax_id_table_lock); |
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list_for_each_entry(wimax_dev, &wimax_id_table, id_table_node) { |
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if (wimax_dev->net_dev->ifindex == ifindex) { |
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dev_hold(wimax_dev->net_dev); |
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goto found; |
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} |
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} |
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wimax_dev = NULL; |
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d_printf(1, NULL, "wimax: no devices found with ifindex %d\n", |
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ifindex); |
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found: |
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spin_unlock(&wimax_id_table_lock); |
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d_fnend(3, NULL, "(info %p ifindex %d) = %p\n", |
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info, ifindex, wimax_dev); |
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return wimax_dev; |
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} |
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/* |
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* wimax_id_table_rm - Remove a gennetlink familiy ID / wimax_dev mapping |
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* |
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* @id: family ID to remove from the table |
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*/ |
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void wimax_id_table_rm(struct wimax_dev *wimax_dev) |
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{ |
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spin_lock(&wimax_id_table_lock); |
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list_del_init(&wimax_dev->id_table_node); |
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spin_unlock(&wimax_id_table_lock); |
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} |
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/* |
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* Release the gennetlink family id / mapping table |
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* |
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* On debug, verify that the table is empty upon removal. We want the |
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* code always compiled, to ensure it doesn't bit rot. It will be |
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* compiled out if CONFIG_BUG is disabled. |
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*/ |
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void wimax_id_table_release(void) |
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{ |
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struct wimax_dev *wimax_dev; |
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#ifndef CONFIG_BUG |
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return; |
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#endif |
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spin_lock(&wimax_id_table_lock); |
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list_for_each_entry(wimax_dev, &wimax_id_table, id_table_node) { |
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pr_err("BUG: %s wimax_dev %p ifindex %d not cleared\n", |
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__func__, wimax_dev, wimax_dev->net_dev->ifindex); |
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WARN_ON(1); |
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} |
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spin_unlock(&wimax_id_table_lock); |
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}
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