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 | |
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 */ |
34 | bool ccid_support_check(u8 const *ccid_array, u8 array_len) |
35 | { |
36 | while (array_len > 0) |
37 | if (ccid_by_number(id: 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 | */ |
49 | int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len) |
50 | { |
51 | *ccid_array = kmalloc(ARRAY_SIZE(ccids), flags: 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 (ccid_get_builtin_ccids(ccid_array: &ccid_array, array_len: &array_len)) |
67 | return -ENOBUFS; |
68 | |
69 | if (put_user(array_len, optlen)) |
70 | err = -EFAULT; |
71 | else if (len > 0 && copy_to_user(to: optval, from: ccid_array, |
72 | n: len > array_len ? array_len : len)) |
73 | err = -EFAULT; |
74 | |
75 | kfree(objp: ccid_array); |
76 | return err; |
77 | } |
78 | |
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(buf: slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args); |
86 | va_end(args); |
87 | |
88 | slab = kmem_cache_create(name: slab_name_fmt, size: sizeof(struct ccid) + obj_size, align: 0, |
89 | SLAB_HWCACHE_ALIGN, NULL); |
90 | return slab; |
91 | } |
92 | |
93 | static void ccid_kmem_cache_destroy(struct kmem_cache *slab) |
94 | { |
95 | kmem_cache_destroy(s: slab); |
96 | } |
97 | |
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(obj_size: ccid_ops->ccid_hc_rx_obj_size, |
104 | slab_name_fmt: ccid_ops->ccid_hc_rx_slab_name, |
105 | fmt: "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(obj_size: ccid_ops->ccid_hc_tx_obj_size, |
112 | slab_name_fmt: ccid_ops->ccid_hc_tx_slab_name, |
113 | fmt: "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(slab: ccid_ops->ccid_hc_rx_slab); |
125 | ccid_ops->ccid_hc_rx_slab = NULL; |
126 | goto out; |
127 | } |
128 | |
129 | static void ccid_deactivate(struct ccid_operations *ccid_ops) |
130 | { |
131 | ccid_kmem_cache_destroy(slab: ccid_ops->ccid_hc_tx_slab); |
132 | ccid_ops->ccid_hc_tx_slab = NULL; |
133 | ccid_kmem_cache_destroy(slab: 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 | |
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(cachep: rx ? ccid_ops->ccid_hc_rx_slab : |
149 | ccid_ops->ccid_hc_tx_slab, flags: 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(s: rx ? ccid_ops->ccid_hc_rx_slab : |
168 | ccid_ops->ccid_hc_tx_slab, objp: ccid); |
169 | ccid = NULL; |
170 | goto out; |
171 | } |
172 | |
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(s: ccid->ccid_ops->ccid_hc_rx_slab, objp: ccid); |
179 | } |
180 | } |
181 | |
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(s: ccid->ccid_ops->ccid_hc_tx_slab, objp: ccid); |
188 | } |
189 | } |
190 | |
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(ccid_ops: ccids[i]); |
200 | if (err) |
201 | goto unwind_registrations; |
202 | } |
203 | return 0; |
204 | |
205 | unwind_registrations: |
206 | while(--i >= 0) |
207 | ccid_deactivate(ccid_ops: ccids[i]); |
208 | tfrc_lib_exit(); |
209 | return err; |
210 | } |
211 | |
212 | void ccid_cleanup_builtins(void) |
213 | { |
214 | int i; |
215 | |
216 | for (i = 0; i < ARRAY_SIZE(ccids); i++) |
217 | ccid_deactivate(ccid_ops: ccids[i]); |
218 | tfrc_lib_exit(); |
219 | } |
220 | |