aboutsummaryrefslogtreecommitdiffstats
path: root/net/dccp/ccid.c
blob: ff16e9df196972fef0c097c3aa464438a2ad556b (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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
/*
 *  net/dccp/ccid.c
 *
 *  An implementation of the DCCP protocol
 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 *
 *  CCID infrastructure
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License version 2 as
 *	published by the Free Software Foundation.
 */

#include "ccid.h"
#include "ccids/lib/tfrc.h"

static struct ccid_operations *ccids[] = {
	&ccid2_ops,
#ifdef CONFIG_IP_DCCP_CCID3
	&ccid3_ops,
#endif
};

static struct ccid_operations *ccid_by_number(const u8 id)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(ccids); i++)
		if (ccids[i]->ccid_id == id)
			return ccids[i];
	return NULL;
}

/* check that up to @array_len members in @ccid_array are supported */
bool ccid_support_check(u8 const *ccid_array, u8 array_len)
{
	while (array_len > 0)
		if (ccid_by_number(ccid_array[--array_len]) == NULL)
			return false;
	return true;
}

/**
 * ccid_get_builtin_ccids  -  Populate a list of built-in CCIDs
 * @ccid_array: pointer to copy into
 * @array_len: value to return length into
 * This function allocates memory - caller must see that it is freed after use.
 */
int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
{
	*ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
	if (*ccid_array == NULL)
		return -ENOBUFS;

	for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
		(*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
	return 0;
}

int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
				  char __user *optval, int __user *optlen)
{
	u8 *ccid_array, array_len;
	int err = 0;

	if (len < ARRAY_SIZE(ccids))
		return -EINVAL;

	if (ccid_get_builtin_ccids(&ccid_array, &array_len))
		return -ENOBUFS;

	if (put_user(array_len, optlen) ||
	    copy_to_user(optval, ccid_array, array_len))
		err = -EFAULT;

	kfree(ccid_array);
	return err;
}

static struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
{
	struct kmem_cache *slab;
	va_list args;

	va_start(args, fmt);
	vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args);
	va_end(args);

	slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
				 SLAB_HWCACHE_ALIGN, NULL);
	return slab;
}

static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
{
	if (slab != NULL)
		kmem_cache_destroy(slab);
}

static int ccid_activate(struct ccid_operations *ccid_ops)
{
	int err = -ENOBUFS;

	ccid_ops->ccid_hc_rx_slab =
			ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
					       ccid_ops->ccid_hc_rx_slab_name,
					       "ccid%u_hc_rx_sock",
					       ccid_ops->ccid_id);
	if (ccid_ops->ccid_hc_rx_slab == NULL)
		goto out;

	ccid_ops->ccid_hc_tx_slab =
			ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
					       ccid_ops->ccid_hc_tx_slab_name,
					       "ccid%u_hc_tx_sock",
					       ccid_ops->ccid_id);
	if (ccid_ops->ccid_hc_tx_slab == NULL)
		goto out_free_rx_slab;

	pr_info("CCID: Activated CCID %d (%s)\n",
		ccid_ops->ccid_id, ccid_ops->ccid_name);
	err = 0;
out:
	return err;
out_free_rx_slab:
	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
	ccid_ops->ccid_hc_rx_slab = NULL;
	goto out;
}

static void ccid_deactivate(struct ccid_operations *ccid_ops)
{
	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
	ccid_ops->ccid_hc_tx_slab = NULL;
	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
	ccid_ops->ccid_hc_rx_slab = NULL;

	pr_info("CCID: Deactivated CCID %d (%s)\n",
		ccid_ops->ccid_id, ccid_ops->ccid_name);
}

struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
{
	struct ccid_operations *ccid_ops = ccid_by_number(id);
	struct ccid *ccid = NULL;

	if (ccid_ops == NULL)
		goto out;

	ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
				     ccid_ops->ccid_hc_tx_slab, gfp_any());
	if (ccid == NULL)
		goto out;
	ccid->ccid_ops = ccid_ops;
	if (rx) {
		memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
		if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
		    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
			goto out_free_ccid;
	} else {
		memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
		if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
		    ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
			goto out_free_ccid;
	}
out:
	return ccid;
out_free_ccid:
	kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
			ccid_ops->ccid_hc_tx_slab, ccid);
	ccid = NULL;
	goto out;
}

void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
{
	if (ccid != NULL) {
		if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
			ccid->ccid_ops->ccid_hc_rx_exit(sk);
		kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
	}
}

void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
{
	if (ccid != NULL) {
		if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
			ccid->ccid_ops->ccid_hc_tx_exit(sk);
		kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
	}
}

int __init ccid_initialize_builtins(void)
{
	int i, err = tfrc_lib_init();

	if (err)
		return err;

	for (i = 0; i < ARRAY_SIZE(ccids); i++) {
		err = ccid_activate(ccids[i]);
		if (err)
			goto unwind_registrations;
	}
	return 0;

unwind_registrations:
	while(--i >= 0)
		ccid_deactivate(ccids[i]);
	tfrc_lib_exit();
	return err;
}

void ccid_cleanup_builtins(void)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(ccids); i++)
		ccid_deactivate(ccids[i]);
	tfrc_lib_exit();
}