xref: /openbmc/linux/net/dccp/ccid.c (revision e105007c)
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 "ccid.h"
15 #include "ccids/lib/tfrc.h"
16 
17 static struct ccid_operations *ccids[] = {
18 	&ccid2_ops,
19 #ifdef CONFIG_IP_DCCP_CCID3
20 	&ccid3_ops,
21 #endif
22 };
23 
24 static struct ccid_operations *ccid_by_number(const u8 id)
25 {
26 	int i;
27 
28 	for (i = 0; i < ARRAY_SIZE(ccids); i++)
29 		if (ccids[i]->ccid_id == id)
30 			return ccids[i];
31 	return NULL;
32 }
33 
34 /* check that up to @array_len members in @ccid_array are supported */
35 bool ccid_support_check(u8 const *ccid_array, u8 array_len)
36 {
37 	while (array_len > 0)
38 		if (ccid_by_number(ccid_array[--array_len]) == NULL)
39 			return false;
40 	return true;
41 }
42 
43 /**
44  * ccid_get_builtin_ccids  -  Populate a list of built-in CCIDs
45  * @ccid_array: pointer to copy into
46  * @array_len: value to return length into
47  * This function allocates memory - caller must see that it is freed after use.
48  */
49 int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len)
50 {
51 	*ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any());
52 	if (*ccid_array == NULL)
53 		return -ENOBUFS;
54 
55 	for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1)
56 		(*ccid_array)[*array_len] = ccids[*array_len]->ccid_id;
57 	return 0;
58 }
59 
60 int ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
61 				  char __user *optval, int __user *optlen)
62 {
63 	u8 *ccid_array, array_len;
64 	int err = 0;
65 
66 	if (len < ARRAY_SIZE(ccids))
67 		return -EINVAL;
68 
69 	if (ccid_get_builtin_ccids(&ccid_array, &array_len))
70 		return -ENOBUFS;
71 
72 	if (put_user(array_len, optlen) ||
73 	    copy_to_user(optval, ccid_array, array_len))
74 		err = -EFAULT;
75 
76 	kfree(ccid_array);
77 	return err;
78 }
79 
80 static struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
81 {
82 	struct kmem_cache *slab;
83 	va_list args;
84 
85 	va_start(args, fmt);
86 	vsnprintf(slab_name_fmt, sizeof(slab_name_fmt), fmt, args);
87 	va_end(args);
88 
89 	slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
90 				 SLAB_HWCACHE_ALIGN, NULL);
91 	return slab;
92 }
93 
94 static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
95 {
96 	if (slab != NULL)
97 		kmem_cache_destroy(slab);
98 }
99 
100 static int ccid_activate(struct ccid_operations *ccid_ops)
101 {
102 	int err = -ENOBUFS;
103 
104 	ccid_ops->ccid_hc_rx_slab =
105 			ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
106 					       ccid_ops->ccid_hc_rx_slab_name,
107 					       "ccid%u_hc_rx_sock",
108 					       ccid_ops->ccid_id);
109 	if (ccid_ops->ccid_hc_rx_slab == NULL)
110 		goto out;
111 
112 	ccid_ops->ccid_hc_tx_slab =
113 			ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
114 					       ccid_ops->ccid_hc_tx_slab_name,
115 					       "ccid%u_hc_tx_sock",
116 					       ccid_ops->ccid_id);
117 	if (ccid_ops->ccid_hc_tx_slab == NULL)
118 		goto out_free_rx_slab;
119 
120 	pr_info("CCID: Activated CCID %d (%s)\n",
121 		ccid_ops->ccid_id, ccid_ops->ccid_name);
122 	err = 0;
123 out:
124 	return err;
125 out_free_rx_slab:
126 	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
127 	ccid_ops->ccid_hc_rx_slab = NULL;
128 	goto out;
129 }
130 
131 static void ccid_deactivate(struct ccid_operations *ccid_ops)
132 {
133 	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
134 	ccid_ops->ccid_hc_tx_slab = NULL;
135 	ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
136 	ccid_ops->ccid_hc_rx_slab = NULL;
137 
138 	pr_info("CCID: Deactivated CCID %d (%s)\n",
139 		ccid_ops->ccid_id, ccid_ops->ccid_name);
140 }
141 
142 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
143 {
144 	struct ccid_operations *ccid_ops = ccid_by_number(id);
145 	struct ccid *ccid = NULL;
146 
147 	if (ccid_ops == NULL)
148 		goto out;
149 
150 	ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
151 				     ccid_ops->ccid_hc_tx_slab, gfp_any());
152 	if (ccid == NULL)
153 		goto out;
154 	ccid->ccid_ops = ccid_ops;
155 	if (rx) {
156 		memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
157 		if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
158 		    ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
159 			goto out_free_ccid;
160 	} else {
161 		memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
162 		if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
163 		    ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
164 			goto out_free_ccid;
165 	}
166 out:
167 	return ccid;
168 out_free_ccid:
169 	kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
170 			ccid_ops->ccid_hc_tx_slab, ccid);
171 	ccid = NULL;
172 	goto out;
173 }
174 
175 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
176 {
177 	if (ccid != NULL) {
178 		if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
179 			ccid->ccid_ops->ccid_hc_rx_exit(sk);
180 		kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
181 	}
182 }
183 
184 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
185 {
186 	if (ccid != NULL) {
187 		if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
188 			ccid->ccid_ops->ccid_hc_tx_exit(sk);
189 		kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
190 	}
191 }
192 
193 int __init ccid_initialize_builtins(void)
194 {
195 	int i, err = tfrc_lib_init();
196 
197 	if (err)
198 		return err;
199 
200 	for (i = 0; i < ARRAY_SIZE(ccids); i++) {
201 		err = ccid_activate(ccids[i]);
202 		if (err)
203 			goto unwind_registrations;
204 	}
205 	return 0;
206 
207 unwind_registrations:
208 	while(--i >= 0)
209 		ccid_deactivate(ccids[i]);
210 	tfrc_lib_exit();
211 	return err;
212 }
213 
214 void ccid_cleanup_builtins(void)
215 {
216 	int i;
217 
218 	for (i = 0; i < ARRAY_SIZE(ccids); i++)
219 		ccid_deactivate(ccids[i]);
220 	tfrc_lib_exit();
221 }
222