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