1/*
2 *  net/dccp/ccid.c
3 *
4 *  An implementation of the DCCP protocol
5 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
7 *  CCID infrastructure
8 *
9 *	This program is free software; you can redistribute it and/or modify it
10 *	under the terms of the GNU General Public License version 2 as
11 *	published by the Free Software Foundation.
12 */
13
14#include <linux/slab.h>
15
16#include "ccid.h"
17#include "ccids/lib/tfrc.h"
18
19static struct ccid_operations *ccids[] = {
20	&ccid2_ops,
21#ifdef CONFIG_IP_DCCP_CCID3
22	&ccid3_ops,
23#endif
24};
25
26static struct ccid_operations *ccid_by_number(const u8 id)
27{
28	int i;
29
30	for (i = 0; i < ARRAY_SIZE(ccids); i++)
31		if (ccids[i]->ccid_id == id)
32			return ccids[i];
33	return NULL;
34}
35
36/* check that up to @array_len members in @ccid_array are supported */
37bool ccid_support_check(u8 const *ccid_array, u8 array_len)
38{
39	while (array_len > 0)
40		if (ccid_by_number(ccid_array[--array_len]) == NULL)
41			return false;
42	return true;
43}
44
45/**
46 * ccid_get_builtin_ccids  -  Populate a list of built-in CCIDs
47 * @ccid_array: pointer to copy into
48 * @array_len: value to return length into
49 * This function allocates memory - caller must see that it is freed after use.
50 */
51int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
52{
53	*ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
54	if (*ccid_array == NULL)
55		return -ENOBUFS;
56
57	for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
58		(*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
59	return 0;
60}
61
62int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
63				  char __user *optval, int __user *optlen)
64{
65	u8 *ccid_array, array_len;
66	int err = 0;
67
68	if (ccid_get_builtin_ccids(&ccid_array, &array_len))
69		return -ENOBUFS;
70
71	if (put_user(array_len, optlen))
72		err = -EFAULT;
73	else if (len > 0 && copy_to_user(optval, ccid_array,
74					 len > array_len ? array_len : len))
75		err = -EFAULT;
76
77	kfree(ccid_array);
78	return err;
79}
80
81static struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
82{
83	struct kmem_cache *slab;
84	va_list args;
85
86	va_start(args, fmt);
87	vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args);
88	va_end(args);
89
90	slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
91				 SLAB_HWCACHE_ALIGN, NULL);
92	return slab;
93}
94
95static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
96{
97	if (slab != NULL)
98		kmem_cache_destroy(slab);
99}
100
101static int ccid_activate(struct ccid_operations *ccid_ops)
102{
103	int err = -ENOBUFS;
104
105	ccid_ops->ccid_hc_rx_slab =
106			ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
107					       ccid_ops->ccid_hc_rx_slab_name,
108					       "ccid%u_hc_rx_sock",
109					       ccid_ops->ccid_id);
110	if (ccid_ops->ccid_hc_rx_slab == NULL)
111		goto out;
112
113	ccid_ops->ccid_hc_tx_slab =
114			ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
115					       ccid_ops->ccid_hc_tx_slab_name,
116					       "ccid%u_hc_tx_sock",
117					       ccid_ops->ccid_id);
118	if (ccid_ops->ccid_hc_tx_slab == NULL)
119		goto out_free_rx_slab;
120
121	pr_info("CCID: Activated CCID %d (%s)\n",
122		ccid_ops->ccid_id, ccid_ops->ccid_name);
123	err = 0;
124out:
125	return err;
126out_free_rx_slab:
127	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
128	ccid_ops->ccid_hc_rx_slab = NULL;
129	goto out;
130}
131
132static void ccid_deactivate(struct ccid_operations *ccid_ops)
133{
134	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
135	ccid_ops->ccid_hc_tx_slab = NULL;
136	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
137	ccid_ops->ccid_hc_rx_slab = NULL;
138
139	pr_info("CCID: Deactivated CCID %d (%s)\n",
140		ccid_ops->ccid_id, ccid_ops->ccid_name);
141}
142
143struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
144{
145	struct ccid_operations *ccid_ops = ccid_by_number(id);
146	struct ccid *ccid = NULL;
147
148	if (ccid_ops == NULL)
149		goto out;
150
151	ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
152				     ccid_ops->ccid_hc_tx_slab, gfp_any());
153	if (ccid == NULL)
154		goto out;
155	ccid->ccid_ops = ccid_ops;
156	if (rx) {
157		memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
158		if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
159		    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
160			goto out_free_ccid;
161	} else {
162		memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
163		if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
164		    ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
165			goto out_free_ccid;
166	}
167out:
168	return ccid;
169out_free_ccid:
170	kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
171			ccid_ops->ccid_hc_tx_slab, ccid);
172	ccid = NULL;
173	goto out;
174}
175
176void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
177{
178	if (ccid != NULL) {
179		if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
180			ccid->ccid_ops->ccid_hc_rx_exit(sk);
181		kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
182	}
183}
184
185void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
186{
187	if (ccid != NULL) {
188		if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
189			ccid->ccid_ops->ccid_hc_tx_exit(sk);
190		kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
191	}
192}
193
194int __init ccid_initialize_builtins(void)
195{
196	int i, err = tfrc_lib_init();
197
198	if (err)
199		return err;
200
201	for (i = 0; i < ARRAY_SIZE(ccids); i++) {
202		err = ccid_activate(ccids[i]);
203		if (err)
204			goto unwind_registrations;
205	}
206	return 0;
207
208unwind_registrations:
209	while(--i >= 0)
210		ccid_deactivate(ccids[i]);
211	tfrc_lib_exit();
212	return err;
213}
214
215void ccid_cleanup_builtins(void)
216{
217	int i;
218
219	for (i = 0; i < ARRAY_SIZE(ccids); i++)
220		ccid_deactivate(ccids[i]);
221	tfrc_lib_exit();
222}
223