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 *
50 * This function allocates memory - caller must see that it is freed after use.
51 */
52int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
53{
54	*ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
55	if (*ccid_array == NULL)
56		return -ENOBUFS;
57
58	for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
59		(*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
60	return 0;
61}
62
63int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
64				  char __user *optval, int __user *optlen)
65{
66	u8 *ccid_array, array_len;
67	int err = 0;
68
69	if (ccid_get_builtin_ccids(&ccid_array, &array_len))
70		return -ENOBUFS;
71
72	if (put_user(array_len, optlen))
73		err = -EFAULT;
74	else if (len > 0 && copy_to_user(optval, ccid_array,
75					 len > array_len ? array_len : len))
76		err = -EFAULT;
77
78	kfree(ccid_array);
79	return err;
80}
81
82static struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
83{
84	struct kmem_cache *slab;
85	va_list args;
86
87	va_start(args, fmt);
88	vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args);
89	va_end(args);
90
91	slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
92				 SLAB_HWCACHE_ALIGN, NULL);
93	return slab;
94}
95
96static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
97{
98	if (slab != NULL)
99		kmem_cache_destroy(slab);
100}
101
102static int __init ccid_activate(struct ccid_operations *ccid_ops)
103{
104	int err = -ENOBUFS;
105
106	ccid_ops->ccid_hc_rx_slab =
107			ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
108					       ccid_ops->ccid_hc_rx_slab_name,
109					       "ccid%u_hc_rx_sock",
110					       ccid_ops->ccid_id);
111	if (ccid_ops->ccid_hc_rx_slab == NULL)
112		goto out;
113
114	ccid_ops->ccid_hc_tx_slab =
115			ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
116					       ccid_ops->ccid_hc_tx_slab_name,
117					       "ccid%u_hc_tx_sock",
118					       ccid_ops->ccid_id);
119	if (ccid_ops->ccid_hc_tx_slab == NULL)
120		goto out_free_rx_slab;
121
122	pr_info("DCCP: Activated CCID %d (%s)\n",
123		ccid_ops->ccid_id, ccid_ops->ccid_name);
124	err = 0;
125out:
126	return err;
127out_free_rx_slab:
128	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
129	ccid_ops->ccid_hc_rx_slab = NULL;
130	goto out;
131}
132
133static void ccid_deactivate(struct ccid_operations *ccid_ops)
134{
135	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
136	ccid_ops->ccid_hc_tx_slab = NULL;
137	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
138	ccid_ops->ccid_hc_rx_slab = NULL;
139
140	pr_info("DCCP: Deactivated CCID %d (%s)\n",
141		ccid_ops->ccid_id, ccid_ops->ccid_name);
142}
143
144struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
145{
146	struct ccid_operations *ccid_ops = ccid_by_number(id);
147	struct ccid *ccid = NULL;
148
149	if (ccid_ops == NULL)
150		goto out;
151
152	ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
153				     ccid_ops->ccid_hc_tx_slab, gfp_any());
154	if (ccid == NULL)
155		goto out;
156	ccid->ccid_ops = ccid_ops;
157	if (rx) {
158		memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
159		if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
160		    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
161			goto out_free_ccid;
162	} else {
163		memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
164		if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
165		    ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
166			goto out_free_ccid;
167	}
168out:
169	return ccid;
170out_free_ccid:
171	kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
172			ccid_ops->ccid_hc_tx_slab, ccid);
173	ccid = NULL;
174	goto out;
175}
176
177void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
178{
179	if (ccid != NULL) {
180		if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
181			ccid->ccid_ops->ccid_hc_rx_exit(sk);
182		kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
183	}
184}
185
186void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
187{
188	if (ccid != NULL) {
189		if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
190			ccid->ccid_ops->ccid_hc_tx_exit(sk);
191		kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
192	}
193}
194
195int __init ccid_initialize_builtins(void)
196{
197	int i, err = tfrc_lib_init();
198
199	if (err)
200		return err;
201
202	for (i = 0; i < ARRAY_SIZE(ccids); i++) {
203		err = ccid_activate(ccids[i]);
204		if (err)
205			goto unwind_registrations;
206	}
207	return 0;
208
209unwind_registrations:
210	while(--i >= 0)
211		ccid_deactivate(ccids[i]);
212	tfrc_lib_exit();
213	return err;
214}
215
216void ccid_cleanup_builtins(void)
217{
218	int i;
219
220	for (i = 0; i < ARRAY_SIZE(ccids); i++)
221		ccid_deactivate(ccids[i]);
222	tfrc_lib_exit();
223}
224