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 19 static struct ccid_operations *ccids[] = { 20 &ccid2_ops, 21 #ifdef CONFIG_IP_DCCP_CCID3 22 &ccid3_ops, 23 #endif 24 }; 25 26 static 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 */ 37 bool 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 */ 52 int 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 63 int 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 82 static 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 96 static void ccid_kmem_cache_destroy(struct kmem_cache *slab) 97 { 98 if (slab != NULL) 99 kmem_cache_destroy(slab); 100 } 101 102 static 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; 125 out: 126 return err; 127 out_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 } 132 133 static 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 } 143 144 struct 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 } 168 out: 169 return ccid; 170 out_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 } 176 177 void 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 } 185 186 void 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 } 194 195 int __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; 208 209 unwind_registrations: 210 while(--i >= 0) 211 ccid_deactivate(ccids[i]); 212 tfrc_lib_exit(); 213 return err; 214 } 215 216 void 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