aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gud/MobiCoreKernelApi/main.c
blob: a3e2e623ccaf229087fdee77ca12e52addc33a68 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
#include <linux/module.h>
#include <linux/init.h>

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/netlink.h>
#include <linux/kthread.h>
#include <net/sock.h>

#include <linux/list.h>

#include "connection.h"
#include "common.h"

#define MC_DAEMON_NETLINK  17

struct mcKernelApiCtx
{
	struct sock *sk;
	struct list_head peers;
	atomic_t counter;
};

struct mcKernelApiCtx* modCtx = NULL;

/*----------------------------------------------------------------------------*/
/* get a unique ID */
unsigned int mcapi_unique_id(
	void
)
{
	return (unsigned int)atomic_inc_return(
		&(modCtx->counter));
}


//------------------------------------------------------------------------------
static connection_t* mcapi_find_connection(
	uint32_t seq
)
{
	connection_t *tmp;
	struct list_head *pos;

	// Get session_t for sessionId
	list_for_each(pos, &modCtx->peers) {
		tmp=list_entry(pos, connection_t, list);
		if (tmp->sequenceMagic == seq) {
			return tmp;
		}
	}

	return NULL;
}

//------------------------------------------------------------------------------
void mcapi_insert_connection(
	connection_t *connection
)
{
	list_add_tail(&(connection->list), &(modCtx->peers));
	connection->socketDescriptor = modCtx->sk;
}

void mcapi_remove_connection(
	uint32_t seq
)
{
	connection_t *tmp;
	struct list_head *pos, *q;

	// Delete all session objects. Usually this should not be needed as
	// closeDevice() requires that all sessions have been closed before.
	list_for_each_safe(pos, q, &modCtx->peers) {
		tmp=list_entry(pos, connection_t, list);
		if (tmp->sequenceMagic == seq) {
			list_del(pos);
			break;
		}
	}
}

//------------------------------------------------------------------------------
static int mcapi_process(
	struct sk_buff *skb,
	struct nlmsghdr *nlh
)
{
	connection_t *c;
	int	length;
	int		seq;
	pid_t	pid;

	pid = nlh->nlmsg_pid;
	length = nlh->nlmsg_len;
	seq = nlh->nlmsg_seq;
	MCDRV_DBG_VERBOSE("nlmsg len %d type %d pid 0x%X seq %d\n",
		   length, nlh->nlmsg_type, pid, seq );

	c = mcapi_find_connection(seq);
	if(!c){
		MCDRV_ERROR("Invalid incomming connection - seq=%u!", seq);
		return -1;
	}

	// Pass the buffer to the appropriate connection
	connection_process(c, skb);

	return 0;
}

//------------------------------------------------------------------------------
static void mcapi_callback(
	struct sk_buff *skb
)
{
	struct nlmsghdr *nlh = nlmsg_hdr(skb);
	int len = skb->len;
	int err = 0;

	while (NLMSG_OK(nlh, len)) {
		err = mcapi_process(skb, nlh);

		/* if err or if this message says it wants a response */
		if (err || (nlh->nlmsg_flags & NLM_F_ACK))
			netlink_ack(skb, nlh, err);

		nlh = NLMSG_NEXT(nlh, len);
	}
}

//------------------------------------------------------------------------------
static int __init mcapi_init(void)
{
	printk(KERN_INFO "Mobicore API module initialized!\n");

	modCtx = kzalloc(sizeof(struct mcKernelApiCtx), GFP_KERNEL);

	/* start kernel thread */
	modCtx->sk = netlink_kernel_create(&init_net, MC_DAEMON_NETLINK, 0,
					mcapi_callback, NULL, THIS_MODULE);

	if (!modCtx->sk) {
		MCDRV_ERROR("register of recieve handler failed");
		kfree(modCtx);
		return -EFAULT;
	}

	INIT_LIST_HEAD(&modCtx->peers);
	return 0;
}

static void __exit mcapi_exit(void)
{
	printk(KERN_INFO "Unloading Mobicore API module.\n");

	if (modCtx->sk != NULL)
	{
		netlink_kernel_release(modCtx->sk);
		modCtx->sk = NULL;
	}
	kfree(modCtx);
	modCtx = NULL;
}

module_init(mcapi_init);
module_exit(mcapi_exit);

MODULE_AUTHOR("Giesecke & Devrient GmbH");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("MobiCore API driver");