1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * net/dccp/ccid.c
4 *
5 * An implementation of the DCCP protocol
6 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
7 *
8 * CCID infrastructure
9 */
10
11 #include <linux/slab.h>
12
13 #include "ccid.h"
14 #include "ccids/lib/tfrc.h"
15
16 static struct ccid_operations *ccids[] = {
17 &ccid2_ops,
18 #ifdef CONFIG_IP_DCCP_CCID3
19 &ccid3_ops,
20 #endif
21 };
22
ccid_by_number(const u8 id)23 static struct ccid_operations *ccid_by_number(const u8 id)
24 {
25 int i;
26
27 for (i = 0; i < ARRAY_SIZE(ccids); i++)
28 if (ccids[i]->ccid_id == id)
29 return ccids[i];
30 return NULL;
31 }
32
33 /* check that up to @array_len members in @ccid_array are supported */
ccid_support_check(u8 const * ccid_array,u8 array_len)34 bool ccid_support_check(u8 const *ccid_array, u8 array_len)
35 {
36 while (array_len > 0)
37 if (ccid_by_number(ccid_array[--array_len]) == NULL)
38 return false;
39 return true;
40 }
41
42 /**
43 * ccid_get_builtin_ccids - Populate a list of built-in CCIDs
44 * @ccid_array: pointer to copy into
45 * @array_len: value to return length into
46 *
47 * This function allocates memory - caller must see that it is freed after use.
48 */
ccid_get_builtin_ccids(u8 ** ccid_array,u8 * array_len)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
ccid_getsockopt_builtin_ccids(struct sock * sk,int len,char __user * optval,int __user * optlen)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 (ccid_get_builtin_ccids(&ccid_array, &array_len))
67 return -ENOBUFS;
68
69 if (put_user(array_len, optlen))
70 err = -EFAULT;
71 else if (len > 0 && copy_to_user(optval, ccid_array,
72 len > array_len ? array_len : len))
73 err = -EFAULT;
74
75 kfree(ccid_array);
76 return err;
77 }
78
ccid_kmem_cache_create(int obj_size,char * slab_name_fmt,const char * fmt,...)79 static __printf(3, 4) struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...)
80 {
81 struct kmem_cache *slab;
82 va_list args;
83
84 va_start(args, fmt);
85 vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args);
86 va_end(args);
87
88 slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0,
89 SLAB_HWCACHE_ALIGN, NULL);
90 return slab;
91 }
92
ccid_kmem_cache_destroy(struct kmem_cache * slab)93 static void ccid_kmem_cache_destroy(struct kmem_cache *slab)
94 {
95 kmem_cache_destroy(slab);
96 }
97
ccid_activate(struct ccid_operations * ccid_ops)98 static int __init ccid_activate(struct ccid_operations *ccid_ops)
99 {
100 int err = -ENOBUFS;
101
102 ccid_ops->ccid_hc_rx_slab =
103 ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size,
104 ccid_ops->ccid_hc_rx_slab_name,
105 "ccid%u_hc_rx_sock",
106 ccid_ops->ccid_id);
107 if (ccid_ops->ccid_hc_rx_slab == NULL)
108 goto out;
109
110 ccid_ops->ccid_hc_tx_slab =
111 ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size,
112 ccid_ops->ccid_hc_tx_slab_name,
113 "ccid%u_hc_tx_sock",
114 ccid_ops->ccid_id);
115 if (ccid_ops->ccid_hc_tx_slab == NULL)
116 goto out_free_rx_slab;
117
118 pr_info("DCCP: Activated CCID %d (%s)\n",
119 ccid_ops->ccid_id, ccid_ops->ccid_name);
120 err = 0;
121 out:
122 return err;
123 out_free_rx_slab:
124 ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
125 ccid_ops->ccid_hc_rx_slab = NULL;
126 goto out;
127 }
128
ccid_deactivate(struct ccid_operations * ccid_ops)129 static void ccid_deactivate(struct ccid_operations *ccid_ops)
130 {
131 ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab);
132 ccid_ops->ccid_hc_tx_slab = NULL;
133 ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
134 ccid_ops->ccid_hc_rx_slab = NULL;
135
136 pr_info("DCCP: Deactivated CCID %d (%s)\n",
137 ccid_ops->ccid_id, ccid_ops->ccid_name);
138 }
139
ccid_new(const u8 id,struct sock * sk,bool rx)140 struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx)
141 {
142 struct ccid_operations *ccid_ops = ccid_by_number(id);
143 struct ccid *ccid = NULL;
144
145 if (ccid_ops == NULL)
146 goto out;
147
148 ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab :
149 ccid_ops->ccid_hc_tx_slab, gfp_any());
150 if (ccid == NULL)
151 goto out;
152 ccid->ccid_ops = ccid_ops;
153 if (rx) {
154 memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size);
155 if (ccid->ccid_ops->ccid_hc_rx_init != NULL &&
156 ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0)
157 goto out_free_ccid;
158 } else {
159 memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size);
160 if (ccid->ccid_ops->ccid_hc_tx_init != NULL &&
161 ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0)
162 goto out_free_ccid;
163 }
164 out:
165 return ccid;
166 out_free_ccid:
167 kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab :
168 ccid_ops->ccid_hc_tx_slab, ccid);
169 ccid = NULL;
170 goto out;
171 }
172
ccid_hc_rx_delete(struct ccid * ccid,struct sock * sk)173 void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk)
174 {
175 if (ccid != NULL) {
176 if (ccid->ccid_ops->ccid_hc_rx_exit != NULL)
177 ccid->ccid_ops->ccid_hc_rx_exit(sk);
178 kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid);
179 }
180 }
181
ccid_hc_tx_delete(struct ccid * ccid,struct sock * sk)182 void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk)
183 {
184 if (ccid != NULL) {
185 if (ccid->ccid_ops->ccid_hc_tx_exit != NULL)
186 ccid->ccid_ops->ccid_hc_tx_exit(sk);
187 kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid);
188 }
189 }
190
ccid_initialize_builtins(void)191 int __init ccid_initialize_builtins(void)
192 {
193 int i, err = tfrc_lib_init();
194
195 if (err)
196 return err;
197
198 for (i = 0; i < ARRAY_SIZE(ccids); i++) {
199 err = ccid_activate(ccids[i]);
200 if (err)
201 goto unwind_registrations;
202 }
203 return 0;
204
205 unwind_registrations:
206 while(--i >= 0)
207 ccid_deactivate(ccids[i]);
208 tfrc_lib_exit();
209 return err;
210 }
211
ccid_cleanup_builtins(void)212 void ccid_cleanup_builtins(void)
213 {
214 int i;
215
216 for (i = 0; i < ARRAY_SIZE(ccids); i++)
217 ccid_deactivate(ccids[i]);
218 tfrc_lib_exit();
219 }
220