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-rw-r--r--Documentation/connector/cn_test.c194
-rw-r--r--Documentation/connector/connector.txt133
-rw-r--r--drivers/Kconfig2
-rw-r--r--drivers/Makefile2
-rw-r--r--drivers/connector/Kconfig13
-rw-r--r--drivers/connector/Makefile3
-rw-r--r--drivers/connector/cn_queue.c173
-rw-r--r--drivers/connector/connector.c486
-rw-r--r--include/linux/connector.h158
-rw-r--r--include/linux/netlink.h1
10 files changed, 1165 insertions, 0 deletions
diff --git a/Documentation/connector/cn_test.c b/Documentation/connector/cn_test.c
new file mode 100644
index 000000000000..b7de82e9c0e0
--- /dev/null
+++ b/Documentation/connector/cn_test.c
@@ -0,0 +1,194 @@
1/*
2 * cn_test.c
3 *
4 * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru>
5 * All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/moduleparam.h>
25#include <linux/skbuff.h>
26#include <linux/timer.h>
27
28#include "connector.h"
29
30static struct cb_id cn_test_id = { 0x123, 0x456 };
31static char cn_test_name[] = "cn_test";
32static struct sock *nls;
33static struct timer_list cn_test_timer;
34
35void cn_test_callback(void *data)
36{
37 struct cn_msg *msg = (struct cn_msg *)data;
38
39 printk("%s: %lu: idx=%x, val=%x, seq=%u, ack=%u, len=%d: %s.\n",
40 __func__, jiffies, msg->id.idx, msg->id.val,
41 msg->seq, msg->ack, msg->len, (char *)msg->data);
42}
43
44static int cn_test_want_notify(void)
45{
46 struct cn_ctl_msg *ctl;
47 struct cn_notify_req *req;
48 struct cn_msg *msg = NULL;
49 int size, size0;
50 struct sk_buff *skb;
51 struct nlmsghdr *nlh;
52 u32 group = 1;
53
54 size0 = sizeof(*msg) + sizeof(*ctl) + 3 * sizeof(*req);
55
56 size = NLMSG_SPACE(size0);
57
58 skb = alloc_skb(size, GFP_ATOMIC);
59 if (!skb) {
60 printk(KERN_ERR "Failed to allocate new skb with size=%u.\n",
61 size);
62
63 return -ENOMEM;
64 }
65
66 nlh = NLMSG_PUT(skb, 0, 0x123, NLMSG_DONE, size - sizeof(*nlh));
67
68 msg = (struct cn_msg *)NLMSG_DATA(nlh);
69
70 memset(msg, 0, size0);
71
72 msg->id.idx = -1;
73 msg->id.val = -1;
74 msg->seq = 0x123;
75 msg->ack = 0x345;
76 msg->len = size0 - sizeof(*msg);
77
78 ctl = (struct cn_ctl_msg *)(msg + 1);
79
80 ctl->idx_notify_num = 1;
81 ctl->val_notify_num = 2;
82 ctl->group = group;
83 ctl->len = msg->len - sizeof(*ctl);
84
85 req = (struct cn_notify_req *)(ctl + 1);
86
87 /*
88 * Idx.
89 */
90 req->first = cn_test_id.idx;
91 req->range = 10;
92
93 /*
94 * Val 0.
95 */
96 req++;
97 req->first = cn_test_id.val;
98 req->range = 10;
99
100 /*
101 * Val 1.
102 */
103 req++;
104 req->first = cn_test_id.val + 20;
105 req->range = 10;
106
107 NETLINK_CB(skb).dst_groups = ctl->group;
108 //netlink_broadcast(nls, skb, 0, ctl->group, GFP_ATOMIC);
109 netlink_unicast(nls, skb, 0, 0);
110
111 printk(KERN_INFO "Request was sent. Group=0x%x.\n", ctl->group);
112
113 return 0;
114
115nlmsg_failure:
116 printk(KERN_ERR "Failed to send %u.%u\n", msg->seq, msg->ack);
117 kfree_skb(skb);
118 return -EINVAL;
119}
120
121static u32 cn_test_timer_counter;
122static void cn_test_timer_func(unsigned long __data)
123{
124 struct cn_msg *m;
125 char data[32];
126
127 m = kmalloc(sizeof(*m) + sizeof(data), GFP_ATOMIC);
128 if (m) {
129 memset(m, 0, sizeof(*m) + sizeof(data));
130
131 memcpy(&m->id, &cn_test_id, sizeof(m->id));
132 m->seq = cn_test_timer_counter;
133 m->len = sizeof(data);
134
135 m->len =
136 scnprintf(data, sizeof(data), "counter = %u",
137 cn_test_timer_counter) + 1;
138
139 memcpy(m + 1, data, m->len);
140
141 cn_netlink_send(m, 0, gfp_any());
142 kfree(m);
143 }
144
145 cn_test_timer_counter++;
146
147 mod_timer(&cn_test_timer, jiffies + HZ);
148}
149
150static int cn_test_init(void)
151{
152 int err;
153
154 err = cn_add_callback(&cn_test_id, cn_test_name, cn_test_callback);
155 if (err)
156 goto err_out;
157 cn_test_id.val++;
158 err = cn_add_callback(&cn_test_id, cn_test_name, cn_test_callback);
159 if (err) {
160 cn_del_callback(&cn_test_id);
161 goto err_out;
162 }
163
164 init_timer(&cn_test_timer);
165 cn_test_timer.function = cn_test_timer_func;
166 cn_test_timer.expires = jiffies + HZ;
167 cn_test_timer.data = 0;
168 add_timer(&cn_test_timer);
169
170 return 0;
171
172 err_out:
173 if (nls && nls->sk_socket)
174 sock_release(nls->sk_socket);
175
176 return err;
177}
178
179static void cn_test_fini(void)
180{
181 del_timer_sync(&cn_test_timer);
182 cn_del_callback(&cn_test_id);
183 cn_test_id.val--;
184 cn_del_callback(&cn_test_id);
185 if (nls && nls->sk_socket)
186 sock_release(nls->sk_socket);
187}
188
189module_init(cn_test_init);
190module_exit(cn_test_fini);
191
192MODULE_LICENSE("GPL");
193MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
194MODULE_DESCRIPTION("Connector's test module");
diff --git a/Documentation/connector/connector.txt b/Documentation/connector/connector.txt
new file mode 100644
index 000000000000..54a0a14bfbe3
--- /dev/null
+++ b/Documentation/connector/connector.txt
@@ -0,0 +1,133 @@
1/*****************************************/
2Kernel Connector.
3/*****************************************/
4
5Kernel connector - new netlink based userspace <-> kernel space easy
6to use communication module.
7
8Connector driver adds possibility to connect various agents using
9netlink based network. One must register callback and
10identifier. When driver receives special netlink message with
11appropriate identifier, appropriate callback will be called.
12
13From the userspace point of view it's quite straightforward:
14
15 socket();
16 bind();
17 send();
18 recv();
19
20But if kernelspace want to use full power of such connections, driver
21writer must create special sockets, must know about struct sk_buff
22handling... Connector allows any kernelspace agents to use netlink
23based networking for inter-process communication in a significantly
24easier way:
25
26int cn_add_callback(struct cb_id *id, char *name, void (*callback) (void *));
27void cn_netlink_send(struct cn_msg *msg, u32 __group, int gfp_mask);
28
29struct cb_id
30{
31 __u32 idx;
32 __u32 val;
33};
34
35idx and val are unique identifiers which must be registered in
36connector.h for in-kernel usage. void (*callback) (void *) - is a
37callback function which will be called when message with above idx.val
38will be received by connector core. Argument for that function must
39be dereferenced to struct cn_msg *.
40
41struct cn_msg
42{
43 struct cb_id id;
44
45 __u32 seq;
46 __u32 ack;
47
48 __u32 len; /* Length of the following data */
49 __u8 data[0];
50};
51
52/*****************************************/
53Connector interfaces.
54/*****************************************/
55
56int cn_add_callback(struct cb_id *id, char *name, void (*callback) (void *));
57
58Registers new callback with connector core.
59
60struct cb_id *id - unique connector's user identifier.
61 It must be registered in connector.h for legal in-kernel users.
62char *name - connector's callback symbolic name.
63void (*callback) (void *) - connector's callback.
64 Argument must be dereferenced to struct cn_msg *.
65
66void cn_del_callback(struct cb_id *id);
67
68Unregisters new callback with connector core.
69
70struct cb_id *id - unique connector's user identifier.
71
72void cn_netlink_send(struct cn_msg *msg, u32 __groups, int gfp_mask);
73
74Sends message to the specified groups. It can be safely called from
75any context, but may silently fail under strong memory pressure.
76
77struct cn_msg * - message header(with attached data).
78u32 __group - destination group.
79 If __group is zero, then appropriate group will
80 be searched through all registered connector users,
81 and message will be delivered to the group which was
82 created for user with the same ID as in msg.
83 If __group is not zero, then message will be delivered
84 to the specified group.
85int gfp_mask - GFP mask.
86
87Note: When registering new callback user, connector core assigns
88netlink group to the user which is equal to it's id.idx.
89
90/*****************************************/
91Protocol description.
92/*****************************************/
93
94Current offers transport layer with fixed header. Recommended
95protocol which uses such header is following:
96
97msg->seq and msg->ack are used to determine message genealogy. When
98someone sends message it puts there locally unique sequence and random
99acknowledge numbers. Sequence number may be copied into
100nlmsghdr->nlmsg_seq too.
101
102Sequence number is incremented with each message to be sent.
103
104If we expect reply to our message, then sequence number in received
105message MUST be the same as in original message, and acknowledge
106number MUST be the same + 1.
107
108If we receive message and it's sequence number is not equal to one we
109are expecting, then it is new message. If we receive message and it's
110sequence number is the same as one we are expecting, but it's
111acknowledge is not equal acknowledge number in original message + 1,
112then it is new message.
113
114Obviously, protocol header contains above id.
115
116connector allows event notification in the following form: kernel
117driver or userspace process can ask connector to notify it when
118selected id's will be turned on or off(registered or unregistered it's
119callback). It is done by sending special command to connector
120driver(it also registers itself with id={-1, -1}).
121
122As example of usage Documentation/connector now contains cn_test.c -
123testing module which uses connector to request notification and to
124send messages.
125
126/*****************************************/
127Reliability.
128/*****************************************/
129
130Netlink itself is not reliable protocol, that means that messages can
131be lost due to memory pressure or process' receiving queue overflowed,
132so caller is warned must be prepared. That is why struct cn_msg [main
133connector's message header] contains u32 seq and u32 ack fields.
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 46d655fab115..48f446d3c671 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -4,6 +4,8 @@ menu "Device Drivers"
4 4
5source "drivers/base/Kconfig" 5source "drivers/base/Kconfig"
6 6
7source "drivers/connector/Kconfig"
8
7source "drivers/mtd/Kconfig" 9source "drivers/mtd/Kconfig"
8 10
9source "drivers/parport/Kconfig" 11source "drivers/parport/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index 86c8654a0ca9..1a109a6dd953 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -17,6 +17,8 @@ obj-$(CONFIG_PNP) += pnp/
17# default. 17# default.
18obj-y += char/ 18obj-y += char/
19 19
20obj-$(CONFIG_CONNECTOR) += connector/
21
20# i810fb and intelfb depend on char/agp/ 22# i810fb and intelfb depend on char/agp/
21obj-$(CONFIG_FB_I810) += video/i810/ 23obj-$(CONFIG_FB_I810) += video/i810/
22obj-$(CONFIG_FB_INTEL) += video/intelfb/ 24obj-$(CONFIG_FB_INTEL) += video/intelfb/
diff --git a/drivers/connector/Kconfig b/drivers/connector/Kconfig
new file mode 100644
index 000000000000..0bc2059c1e08
--- /dev/null
+++ b/drivers/connector/Kconfig
@@ -0,0 +1,13 @@
1menu "Connector - unified userspace <-> kernelspace linker"
2
3config CONNECTOR
4 tristate "Connector - unified userspace <-> kernelspace linker"
5 depends on NET
6 ---help---
7 This is unified userspace <-> kernelspace connector working on top
8 of the netlink socket protocol.
9
10 Connector support can also be built as a module. If so, the module
11 will be called cn.ko.
12
13endmenu
diff --git a/drivers/connector/Makefile b/drivers/connector/Makefile
new file mode 100644
index 000000000000..12ca79e8234d
--- /dev/null
+++ b/drivers/connector/Makefile
@@ -0,0 +1,3 @@
1obj-$(CONFIG_CONNECTOR) += cn.o
2
3cn-y += cn_queue.o connector.o
diff --git a/drivers/connector/cn_queue.c b/drivers/connector/cn_queue.c
new file mode 100644
index 000000000000..966632182e2d
--- /dev/null
+++ b/drivers/connector/cn_queue.c
@@ -0,0 +1,173 @@
1/*
2 * cn_queue.c
3 *
4 * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru>
5 * All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 */
22
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/list.h>
26#include <linux/workqueue.h>
27#include <linux/spinlock.h>
28#include <linux/slab.h>
29#include <linux/skbuff.h>
30#include <linux/suspend.h>
31#include <linux/connector.h>
32#include <linux/delay.h>
33
34static void cn_queue_wrapper(void *data)
35{
36 struct cn_callback_entry *cbq = data;
37
38 cbq->cb->callback(cbq->cb->priv);
39 cbq->destruct_data(cbq->ddata);
40 cbq->ddata = NULL;
41}
42
43static struct cn_callback_entry *cn_queue_alloc_callback_entry(struct cn_callback *cb)
44{
45 struct cn_callback_entry *cbq;
46
47 cbq = kzalloc(sizeof(*cbq), GFP_KERNEL);
48 if (!cbq) {
49 printk(KERN_ERR "Failed to create new callback queue.\n");
50 return NULL;
51 }
52
53 cbq->cb = cb;
54 INIT_WORK(&cbq->work, &cn_queue_wrapper, cbq);
55 return cbq;
56}
57
58static void cn_queue_free_callback(struct cn_callback_entry *cbq)
59{
60 cancel_delayed_work(&cbq->work);
61 flush_workqueue(cbq->pdev->cn_queue);
62
63 kfree(cbq);
64}
65
66int cn_cb_equal(struct cb_id *i1, struct cb_id *i2)
67{
68 return ((i1->idx == i2->idx) && (i1->val == i2->val));
69}
70
71int cn_queue_add_callback(struct cn_queue_dev *dev, struct cn_callback *cb)
72{
73 struct cn_callback_entry *cbq, *__cbq;
74 int found = 0;
75
76 cbq = cn_queue_alloc_callback_entry(cb);
77 if (!cbq)
78 return -ENOMEM;
79
80 atomic_inc(&dev->refcnt);
81 cbq->pdev = dev;
82
83 spin_lock_bh(&dev->queue_lock);
84 list_for_each_entry(__cbq, &dev->queue_list, callback_entry) {
85 if (cn_cb_equal(&__cbq->cb->id, &cb->id)) {
86 found = 1;
87 break;
88 }
89 }
90 if (!found)
91 list_add_tail(&cbq->callback_entry, &dev->queue_list);
92 spin_unlock_bh(&dev->queue_lock);
93
94 if (found) {
95 atomic_dec(&dev->refcnt);
96 cn_queue_free_callback(cbq);
97 return -EINVAL;
98 }
99
100 cbq->nls = dev->nls;
101 cbq->seq = 0;
102 cbq->group = cbq->cb->id.idx;
103
104 return 0;
105}
106
107void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id)
108{
109 struct cn_callback_entry *cbq, *n;
110 int found = 0;
111
112 spin_lock_bh(&dev->queue_lock);
113 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) {
114 if (cn_cb_equal(&cbq->cb->id, id)) {
115 list_del(&cbq->callback_entry);
116 found = 1;
117 break;
118 }
119 }
120 spin_unlock_bh(&dev->queue_lock);
121
122 if (found) {
123 cn_queue_free_callback(cbq);
124 atomic_dec_and_test(&dev->refcnt);
125 }
126}
127
128struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *nls)
129{
130 struct cn_queue_dev *dev;
131
132 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
133 if (!dev)
134 return NULL;
135
136 snprintf(dev->name, sizeof(dev->name), "%s", name);
137 atomic_set(&dev->refcnt, 0);
138 INIT_LIST_HEAD(&dev->queue_list);
139 spin_lock_init(&dev->queue_lock);
140
141 dev->nls = nls;
142 dev->netlink_groups = 0;
143
144 dev->cn_queue = create_workqueue(dev->name);
145 if (!dev->cn_queue) {
146 kfree(dev);
147 return NULL;
148 }
149
150 return dev;
151}
152
153void cn_queue_free_dev(struct cn_queue_dev *dev)
154{
155 struct cn_callback_entry *cbq, *n;
156
157 flush_workqueue(dev->cn_queue);
158 destroy_workqueue(dev->cn_queue);
159
160 spin_lock_bh(&dev->queue_lock);
161 list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
162 list_del(&cbq->callback_entry);
163 spin_unlock_bh(&dev->queue_lock);
164
165 while (atomic_read(&dev->refcnt)) {
166 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
167 dev->name, atomic_read(&dev->refcnt));
168 msleep(1000);
169 }
170
171 kfree(dev);
172 dev = NULL;
173}
diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
new file mode 100644
index 000000000000..aaf6d468a8b9
--- /dev/null
+++ b/drivers/connector/connector.c
@@ -0,0 +1,486 @@
1/*
2 * connector.c
3 *
4 * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru>
5 * All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/list.h>
25#include <linux/skbuff.h>
26#include <linux/netlink.h>
27#include <linux/moduleparam.h>
28#include <linux/connector.h>
29
30#include <net/sock.h>
31
32MODULE_LICENSE("GPL");
33MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
34MODULE_DESCRIPTION("Generic userspace <-> kernelspace connector.");
35
36static u32 cn_idx = CN_IDX_CONNECTOR;
37static u32 cn_val = CN_VAL_CONNECTOR;
38
39module_param(cn_idx, uint, 0);
40module_param(cn_val, uint, 0);
41MODULE_PARM_DESC(cn_idx, "Connector's main device idx.");
42MODULE_PARM_DESC(cn_val, "Connector's main device val.");
43
44static DECLARE_MUTEX(notify_lock);
45static LIST_HEAD(notify_list);
46
47static struct cn_dev cdev;
48
49int cn_already_initialized = 0;
50
51/*
52 * msg->seq and msg->ack are used to determine message genealogy.
53 * When someone sends message it puts there locally unique sequence
54 * and random acknowledge numbers. Sequence number may be copied into
55 * nlmsghdr->nlmsg_seq too.
56 *
57 * Sequence number is incremented with each message to be sent.
58 *
59 * If we expect reply to our message then the sequence number in
60 * received message MUST be the same as in original message, and
61 * acknowledge number MUST be the same + 1.
62 *
63 * If we receive a message and its sequence number is not equal to the
64 * one we are expecting then it is a new message.
65 *
66 * If we receive a message and its sequence number is the same as one
67 * we are expecting but it's acknowledgement number is not equal to
68 * the acknowledgement number in the original message + 1, then it is
69 * a new message.
70 *
71 */
72int cn_netlink_send(struct cn_msg *msg, u32 __group, int gfp_mask)
73{
74 struct cn_callback_entry *__cbq;
75 unsigned int size;
76 struct sk_buff *skb;
77 struct nlmsghdr *nlh;
78 struct cn_msg *data;
79 struct cn_dev *dev = &cdev;
80 u32 group = 0;
81 int found = 0;
82
83 if (!__group) {
84 spin_lock_bh(&dev->cbdev->queue_lock);
85 list_for_each_entry(__cbq, &dev->cbdev->queue_list,
86 callback_entry) {
87 if (cn_cb_equal(&__cbq->cb->id, &msg->id)) {
88 found = 1;
89 group = __cbq->group;
90 }
91 }
92 spin_unlock_bh(&dev->cbdev->queue_lock);
93
94 if (!found)
95 return -ENODEV;
96 } else {
97 group = __group;
98 }
99
100 size = NLMSG_SPACE(sizeof(*msg) + msg->len);
101
102 skb = alloc_skb(size, gfp_mask);
103 if (!skb)
104 return -ENOMEM;
105
106 nlh = NLMSG_PUT(skb, 0, msg->seq, NLMSG_DONE, size - sizeof(*nlh));
107
108 data = NLMSG_DATA(nlh);
109
110 memcpy(data, msg, sizeof(*data) + msg->len);
111
112 NETLINK_CB(skb).dst_group = group;
113
114 netlink_broadcast(dev->nls, skb, 0, group, gfp_mask);
115
116 return 0;
117
118nlmsg_failure:
119 kfree_skb(skb);
120 return -EINVAL;
121}
122
123/*
124 * Callback helper - queues work and setup destructor for given data.
125 */
126static int cn_call_callback(struct cn_msg *msg, void (*destruct_data)(void *), void *data)
127{
128 struct cn_callback_entry *__cbq;
129 struct cn_dev *dev = &cdev;
130 int found = 0;
131
132 spin_lock_bh(&dev->cbdev->queue_lock);
133 list_for_each_entry(__cbq, &dev->cbdev->queue_list, callback_entry) {
134 if (cn_cb_equal(&__cbq->cb->id, &msg->id)) {
135 /*
136 * Let's scream if there is some magic and the
137 * data will arrive asynchronously here.
138 * [i.e. netlink messages will be queued].
139 * After the first warning I will fix it
140 * quickly, but now I think it is
141 * impossible. --zbr (2004_04_27).
142 */
143 if (likely(!test_bit(0, &__cbq->work.pending) &&
144 __cbq->ddata == NULL)) {
145 __cbq->cb->priv = msg;
146
147 __cbq->ddata = data;
148 __cbq->destruct_data = destruct_data;
149
150 if (queue_work(dev->cbdev->cn_queue,
151 &__cbq->work))
152 found = 1;
153 } else {
154 printk("%s: cbq->data=%p, "
155 "work->pending=%08lx.\n",
156 __func__, __cbq->ddata,
157 __cbq->work.pending);
158 WARN_ON(1);
159 }
160 break;
161 }
162 }
163 spin_unlock_bh(&dev->cbdev->queue_lock);
164
165 return found ? 0 : -ENODEV;
166}
167
168/*
169 * Skb receive helper - checks skb and msg size and calls callback
170 * helper.
171 */
172static int __cn_rx_skb(struct sk_buff *skb, struct nlmsghdr *nlh)
173{
174 u32 pid, uid, seq, group;
175 struct cn_msg *msg;
176
177 pid = NETLINK_CREDS(skb)->pid;
178 uid = NETLINK_CREDS(skb)->uid;
179 seq = nlh->nlmsg_seq;
180 group = NETLINK_CB((skb)).dst_group;
181 msg = NLMSG_DATA(nlh);
182
183 return cn_call_callback(msg, (void (*)(void *))kfree_skb, skb);
184}
185
186/*
187 * Main netlink receiving function.
188 *
189 * It checks skb and netlink header sizes and calls the skb receive
190 * helper with a shared skb.
191 */
192static void cn_rx_skb(struct sk_buff *__skb)
193{
194 struct nlmsghdr *nlh;
195 u32 len;
196 int err;
197 struct sk_buff *skb;
198
199 skb = skb_get(__skb);
200
201 if (skb->len >= NLMSG_SPACE(0)) {
202 nlh = (struct nlmsghdr *)skb->data;
203
204 if (nlh->nlmsg_len < sizeof(struct cn_msg) ||
205 skb->len < nlh->nlmsg_len ||
206 nlh->nlmsg_len > CONNECTOR_MAX_MSG_SIZE) {
207 kfree_skb(skb);
208 goto out;
209 }
210
211 len = NLMSG_ALIGN(nlh->nlmsg_len);
212 if (len > skb->len)
213 len = skb->len;
214
215 err = __cn_rx_skb(skb, nlh);
216 if (err < 0)
217 kfree_skb(skb);
218 }
219
220out:
221 kfree_skb(__skb);
222}
223
224/*
225 * Netlink socket input callback - dequeues the skbs and calls the
226 * main netlink receiving function.
227 */
228static void cn_input(struct sock *sk, int len)
229{
230 struct sk_buff *skb;
231
232 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL)
233 cn_rx_skb(skb);
234}
235
236/*
237 * Notification routing.
238 *
239 * Gets id and checks if there are notification request for it's idx
240 * and val. If there are such requests notify the listeners with the
241 * given notify event.
242 *
243 */
244static void cn_notify(struct cb_id *id, u32 notify_event)
245{
246 struct cn_ctl_entry *ent;
247
248 down(&notify_lock);
249 list_for_each_entry(ent, &notify_list, notify_entry) {
250 int i;
251 struct cn_notify_req *req;
252 struct cn_ctl_msg *ctl = ent->msg;
253 int idx_found, val_found;
254
255 idx_found = val_found = 0;
256
257 req = (struct cn_notify_req *)ctl->data;
258 for (i = 0; i < ctl->idx_notify_num; ++i, ++req) {
259 if (id->idx >= req->first &&
260 id->idx < req->first + req->range) {
261 idx_found = 1;
262 break;
263 }
264 }
265
266 for (i = 0; i < ctl->val_notify_num; ++i, ++req) {
267 if (id->val >= req->first &&
268 id->val < req->first + req->range) {
269 val_found = 1;
270 break;
271 }
272 }
273
274 if (idx_found && val_found) {
275 struct cn_msg m = { .ack = notify_event, };
276
277 memcpy(&m.id, id, sizeof(m.id));
278 cn_netlink_send(&m, ctl->group, GFP_KERNEL);
279 }
280 }
281 up(&notify_lock);
282}
283
284/*
285 * Callback add routing - adds callback with given ID and name.
286 * If there is registered callback with the same ID it will not be added.
287 *
288 * May sleep.
289 */
290int cn_add_callback(struct cb_id *id, char *name, void (*callback)(void *))
291{
292 int err;
293 struct cn_dev *dev = &cdev;
294 struct cn_callback *cb;
295
296 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
297 if (!cb)
298 return -ENOMEM;
299
300 scnprintf(cb->name, sizeof(cb->name), "%s", name);
301
302 memcpy(&cb->id, id, sizeof(cb->id));
303 cb->callback = callback;
304
305 err = cn_queue_add_callback(dev->cbdev, cb);
306 if (err) {
307 kfree(cb);
308 return err;
309 }
310
311 cn_notify(id, 0);
312
313 return 0;
314}
315
316/*
317 * Callback remove routing - removes callback
318 * with given ID.
319 * If there is no registered callback with given
320 * ID nothing happens.
321 *
322 * May sleep while waiting for reference counter to become zero.
323 */
324void cn_del_callback(struct cb_id *id)
325{
326 struct cn_dev *dev = &cdev;
327
328 cn_queue_del_callback(dev->cbdev, id);
329 cn_notify(id, 1);
330}
331
332/*
333 * Checks two connector's control messages to be the same.
334 * Returns 1 if they are the same or if the first one is corrupted.
335 */
336static int cn_ctl_msg_equals(struct cn_ctl_msg *m1, struct cn_ctl_msg *m2)
337{
338 int i;
339 struct cn_notify_req *req1, *req2;
340
341 if (m1->idx_notify_num != m2->idx_notify_num)
342 return 0;
343
344 if (m1->val_notify_num != m2->val_notify_num)
345 return 0;
346
347 if (m1->len != m2->len)
348 return 0;
349
350 if ((m1->idx_notify_num + m1->val_notify_num) * sizeof(*req1) !=
351 m1->len)
352 return 1;
353
354 req1 = (struct cn_notify_req *)m1->data;
355 req2 = (struct cn_notify_req *)m2->data;
356
357 for (i = 0; i < m1->idx_notify_num; ++i) {
358 if (req1->first != req2->first || req1->range != req2->range)
359 return 0;
360 req1++;
361 req2++;
362 }
363
364 for (i = 0; i < m1->val_notify_num; ++i) {
365 if (req1->first != req2->first || req1->range != req2->range)
366 return 0;
367 req1++;
368 req2++;
369 }
370
371 return 1;
372}
373
374/*
375 * Main connector device's callback.
376 *
377 * Used for notification of a request's processing.
378 */
379static void cn_callback(void *data)
380{
381 struct cn_msg *msg = data;
382 struct cn_ctl_msg *ctl;
383 struct cn_ctl_entry *ent;
384 u32 size;
385
386 if (msg->len < sizeof(*ctl))
387 return;
388
389 ctl = (struct cn_ctl_msg *)msg->data;
390
391 size = (sizeof(*ctl) + ((ctl->idx_notify_num +
392 ctl->val_notify_num) *
393 sizeof(struct cn_notify_req)));
394
395 if (msg->len != size)
396 return;
397
398 if (ctl->len + sizeof(*ctl) != msg->len)
399 return;
400
401 /*
402 * Remove notification.
403 */
404 if (ctl->group == 0) {
405 struct cn_ctl_entry *n;
406
407 down(&notify_lock);
408 list_for_each_entry_safe(ent, n, &notify_list, notify_entry) {
409 if (cn_ctl_msg_equals(ent->msg, ctl)) {
410 list_del(&ent->notify_entry);
411 kfree(ent);
412 }
413 }
414 up(&notify_lock);
415
416 return;
417 }
418
419 size += sizeof(*ent);
420
421 ent = kzalloc(size, GFP_KERNEL);
422 if (!ent)
423 return;
424
425 ent->msg = (struct cn_ctl_msg *)(ent + 1);
426
427 memcpy(ent->msg, ctl, size - sizeof(*ent));
428
429 down(&notify_lock);
430 list_add(&ent->notify_entry, &notify_list);
431 up(&notify_lock);
432}
433
434static int __init cn_init(void)
435{
436 struct cn_dev *dev = &cdev;
437 int err;
438
439 dev->input = cn_input;
440 dev->id.idx = cn_idx;
441 dev->id.val = cn_val;
442
443 dev->nls = netlink_kernel_create(NETLINK_CONNECTOR,
444 CN_NETLINK_USERS + 0xf,
445 dev->input, THIS_MODULE);
446 if (!dev->nls)
447 return -EIO;
448
449 dev->cbdev = cn_queue_alloc_dev("cqueue", dev->nls);
450 if (!dev->cbdev) {
451 if (dev->nls->sk_socket)
452 sock_release(dev->nls->sk_socket);
453 return -EINVAL;
454 }
455
456 err = cn_add_callback(&dev->id, "connector", &cn_callback);
457 if (err) {
458 cn_queue_free_dev(dev->cbdev);
459 if (dev->nls->sk_socket)
460 sock_release(dev->nls->sk_socket);
461 return -EINVAL;
462 }
463
464 cn_already_initialized = 1;
465
466 return 0;
467}
468
469static void __exit cn_fini(void)
470{
471 struct cn_dev *dev = &cdev;
472
473 cn_already_initialized = 0;
474
475 cn_del_callback(&dev->id);
476 cn_queue_free_dev(dev->cbdev);
477 if (dev->nls->sk_socket)
478 sock_release(dev->nls->sk_socket);
479}
480
481module_init(cn_init);
482module_exit(cn_fini);
483
484EXPORT_SYMBOL_GPL(cn_add_callback);
485EXPORT_SYMBOL_GPL(cn_del_callback);
486EXPORT_SYMBOL_GPL(cn_netlink_send);
diff --git a/include/linux/connector.h b/include/linux/connector.h
new file mode 100644
index 000000000000..96de26301f84
--- /dev/null
+++ b/include/linux/connector.h
@@ -0,0 +1,158 @@
1/*
2 * connector.h
3 *
4 * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru>
5 * All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#ifndef __CONNECTOR_H
23#define __CONNECTOR_H
24
25#include <asm/types.h>
26
27#define CN_IDX_CONNECTOR 0xffffffff
28#define CN_VAL_CONNECTOR 0xffffffff
29
30#define CN_NETLINK_USERS 1
31
32/*
33 * Maximum connector's message size.
34 */
35#define CONNECTOR_MAX_MSG_SIZE 1024
36
37/*
38 * idx and val are unique identifiers which
39 * are used for message routing and
40 * must be registered in connector.h for in-kernel usage.
41 */
42
43struct cb_id {
44 __u32 idx;
45 __u32 val;
46};
47
48struct cn_msg {
49 struct cb_id id;
50
51 __u32 seq;
52 __u32 ack;
53
54 __u16 len; /* Length of the following data */
55 __u16 flags;
56 __u8 data[0];
57};
58
59/*
60 * Notify structure - requests notification about
61 * registering/unregistering idx/val in range [first, first+range].
62 */
63struct cn_notify_req {
64 __u32 first;
65 __u32 range;
66};
67
68/*
69 * Main notification control message
70 * *_notify_num - number of appropriate cn_notify_req structures after
71 * this struct.
72 * group - notification receiver's idx.
73 * len - total length of the attached data.
74 */
75struct cn_ctl_msg {
76 __u32 idx_notify_num;
77 __u32 val_notify_num;
78 __u32 group;
79 __u32 len;
80 __u8 data[0];
81};
82
83#ifdef __KERNEL__
84
85#include <asm/atomic.h>
86
87#include <linux/list.h>
88#include <linux/workqueue.h>
89
90#include <net/sock.h>
91
92#define CN_CBQ_NAMELEN 32
93
94struct cn_queue_dev {
95 atomic_t refcnt;
96 unsigned char name[CN_CBQ_NAMELEN];
97
98 struct workqueue_struct *cn_queue;
99
100 struct list_head queue_list;
101 spinlock_t queue_lock;
102
103 int netlink_groups;
104 struct sock *nls;
105};
106
107struct cn_callback {
108 unsigned char name[CN_CBQ_NAMELEN];
109
110 struct cb_id id;
111 void (*callback) (void *);
112 void *priv;
113};
114
115struct cn_callback_entry {
116 struct list_head callback_entry;
117 struct cn_callback *cb;
118 struct work_struct work;
119 struct cn_queue_dev *pdev;
120
121 void (*destruct_data) (void *);
122 void *ddata;
123
124 int seq, group;
125 struct sock *nls;
126};
127
128struct cn_ctl_entry {
129 struct list_head notify_entry;
130 struct cn_ctl_msg *msg;
131};
132
133struct cn_dev {
134 struct cb_id id;
135
136 u32 seq, groups;
137 struct sock *nls;
138 void (*input) (struct sock * sk, int len);
139
140 struct cn_queue_dev *cbdev;
141};
142
143int cn_add_callback(struct cb_id *, char *, void (*callback) (void *));
144void cn_del_callback(struct cb_id *);
145int cn_netlink_send(struct cn_msg *, u32, int);
146
147int cn_queue_add_callback(struct cn_queue_dev *dev, struct cn_callback *cb);
148void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id);
149
150struct cn_queue_dev *cn_queue_alloc_dev(char *name, struct sock *);
151void cn_queue_free_dev(struct cn_queue_dev *dev);
152
153int cn_cb_equal(struct cb_id *, struct cb_id *);
154
155extern int cn_already_initialized;
156
157#endif /* __KERNEL__ */
158#endif /* __CONNECTOR_H */
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 167518668936..7bbd25970c9e 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -15,6 +15,7 @@
15#define NETLINK_ISCSI 8 /* Open-iSCSI */ 15#define NETLINK_ISCSI 8 /* Open-iSCSI */
16#define NETLINK_AUDIT 9 /* auditing */ 16#define NETLINK_AUDIT 9 /* auditing */
17#define NETLINK_FIB_LOOKUP 10 17#define NETLINK_FIB_LOOKUP 10
18#define NETLINK_CONNECTOR 11
18#define NETLINK_NETFILTER 12 /* netfilter subsystem */ 19#define NETLINK_NETFILTER 12 /* netfilter subsystem */
19#define NETLINK_IP6_FW 13 20#define NETLINK_IP6_FW 13
20#define NETLINK_DNRTMSG 14 /* DECnet routing messages */ 21#define NETLINK_DNRTMSG 14 /* DECnet routing messages */
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-10 11:48:46 -0500