bsd/net/net_str_id.c

   1 /*
   2  * Copyright (c) 2008,2011 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <sys/types.h>
  30 #include <kern/locks.h>
  31 #include <kern/kalloc.h>
  32 #include <sys/errno.h>
  33 #include <sys/sysctl.h>
  34 #include <sys/malloc.h>
  35 #include <sys/socket.h>
  36 #include <libkern/OSAtomic.h>
  37 #include <libkern/libkern.h>
  38 #include <net/if.h>
  39 #include <net/if_mib.h>
  40 #include <string.h>
  41
  42 #include "net/net_str_id.h"
  43
  44 #define NET_ID_STR_ENTRY_SIZE(__str) \
  45         ((size_t)&(((struct net_str_id_entry*)0)->nsi_string[0]) + \
  46         strlen(__str) + 1)
  47
  48 #define FIRST_NET_STR_ID                                1000
  49 static SLIST_HEAD(,net_str_id_entry)    net_str_id_list = {NULL};
  50 decl_lck_mtx_data(static, net_str_id_lock_data);
  51 static lck_mtx_t        *net_str_id_lock = &net_str_id_lock_data;
  52
  53 static u_int32_t nsi_kind_next[NSI_MAX_KIND] = { FIRST_NET_STR_ID, FIRST_NET_STR_ID, FIRST_NET_STR_ID };
  54 static u_int32_t nsi_next_id = FIRST_NET_STR_ID;
  55
  56 extern int sysctl_if_family_ids SYSCTL_HANDLER_ARGS;
  57
  58 SYSCTL_DECL(_net_link_generic_system);
  59
  60 SYSCTL_PROC(_net_link_generic_system, OID_AUTO, if_family_ids, CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
  61         0, 0, sysctl_if_family_ids, "S, if_family_id", "Interface Family ID table");
  62
  63 __private_extern__ void
  64 net_str_id_init(void)
  65 {
  66         lck_grp_attr_t  *grp_attrib = NULL;
  67         lck_attr_t              *lck_attrb = NULL;
  68         lck_grp_t               *lck_group = NULL;
  69
  70         grp_attrib = lck_grp_attr_alloc_init();
  71         lck_group = lck_grp_alloc_init("mbuf_tag_allocate_id", grp_attrib);
  72         lck_grp_attr_free(grp_attrib);
  73         lck_attrb = lck_attr_alloc_init();
  74
  75         lck_mtx_init(net_str_id_lock, lck_group, lck_attrb);
  76
  77         lck_grp_free(lck_group);
  78         lck_attr_free(lck_attrb);
  79 }
  80
  81 __private_extern__ void
  82 net_str_id_first_last(u_int32_t *first, u_int32_t *last, u_int32_t kind)
  83 {
  84         *first = FIRST_NET_STR_ID;
  85
  86         switch (kind) {
  87                 case NSI_MBUF_TAG:
  88                 case NSI_VENDOR_CODE:
  89                 case NSI_IF_FAM_ID:
  90                         *last = nsi_kind_next[kind] - 1;
  91                         break;
  92                 default:
  93                         *last = FIRST_NET_STR_ID - 1;
  94                         break;
  95         }
  96 }
  97
  98 __private_extern__ errno_t
  99 net_str_id_find_internal(const char     *string, u_int32_t *out_id,
 100                                                   u_int32_t     kind, int create)
 101 {
 102         struct net_str_id_entry                 *entry = NULL;
 103
 104
 105         if (string == NULL || out_id == NULL || kind >= NSI_MAX_KIND)
 106                 return EINVAL;
 107
 108         *out_id = 0;
 109
 110         /* Look for an existing entry */
 111         lck_mtx_lock(net_str_id_lock);
 112         SLIST_FOREACH(entry, &net_str_id_list, nsi_next) {
 113                 if (strcmp(string, entry->nsi_string) == 0) {
 114                         break;
 115                 }
 116         }
 117
 118         if (entry == NULL) {
 119                 if (create == 0) {
 120                         lck_mtx_unlock(net_str_id_lock);
 121                         return ENOENT;
 122                 }
 123
 124                 entry = kalloc(NET_ID_STR_ENTRY_SIZE(string));
 125                 if (entry == NULL) {
 126                         lck_mtx_unlock(net_str_id_lock);
 127                         return ENOMEM;
 128                 }
 129
 130                 strlcpy(entry->nsi_string, string, strlen(string) + 1);
 131                 entry->nsi_flags = (1 << kind);
 132                 entry->nsi_id = nsi_next_id++;
 133                 nsi_kind_next[kind] = nsi_next_id;
 134                 SLIST_INSERT_HEAD(&net_str_id_list, entry, nsi_next);
 135         } else if ((entry->nsi_flags & (1 << kind)) == 0) {
 136                 if (create == 0) {
 137                         lck_mtx_unlock(net_str_id_lock);
 138                         return ENOENT;
 139                 }
 140                 entry->nsi_flags |= (1 << kind);
 141                 if (entry->nsi_id >= nsi_kind_next[kind])
 142                         nsi_kind_next[kind] = entry->nsi_id + 1;
 143         }
 144         lck_mtx_unlock(net_str_id_lock);
 145
 146         *out_id = entry->nsi_id;
 147
 148         return 0;
 149 }
 150
 151
 152 #define ROUNDUP32(a) \
 153         ((a) > 0 ? (1 + (((a) - 1) | (sizeof(uint32_t) - 1))) : sizeof(uint32_t))
 154
 155 int
 156 sysctl_if_family_ids SYSCTL_HANDLER_ARGS /* XXX bad syntax! */
 157 {
 158 #pragma unused(oidp)
 159 #pragma unused(arg1)
 160 #pragma unused(arg2)
 161         errno_t error = 0;
 162         struct net_str_id_entry *entry = NULL;
 163         struct if_family_id *iffmid = NULL;
 164         size_t max_size = 0;
 165
 166         lck_mtx_lock(net_str_id_lock);
 167         SLIST_FOREACH(entry, &net_str_id_list, nsi_next) {
 168                 size_t str_size;
 169                 size_t iffmid_size;
 170
 171                 if ((entry->nsi_flags & (1 << NSI_IF_FAM_ID)) == 0)
 172                         continue;
 173
 174                 str_size = strlen(entry->nsi_string) + 1;
 175                 iffmid_size = ROUNDUP32(offsetof(struct net_str_id_entry, nsi_string) + str_size);
 176
 177                 if (iffmid_size > max_size) {
 178                         if (iffmid)
 179                                 _FREE(iffmid, M_TEMP);
 180                         iffmid = _MALLOC(iffmid_size, M_TEMP, M_WAITOK);
 181                         if (iffmid == NULL) {
 182                                 lck_mtx_unlock(net_str_id_lock);
 183                                 error = ENOMEM;
 184                                 goto done;
 185                         }
 186                         max_size = iffmid_size;
 187                 }
 188
 189                 bzero(iffmid, iffmid_size);
 190                 iffmid->iffmid_len = iffmid_size;
 191                 iffmid->iffmid_id = entry->nsi_id;
 192                 strlcpy(iffmid->iffmid_str, entry->nsi_string, str_size);
 193         error = SYSCTL_OUT(req, iffmid, iffmid_size);
 194         if (error) {
 195                         lck_mtx_unlock(net_str_id_lock);
 196                         goto done;
 197         }
 198
 199         }
 200         lck_mtx_unlock(net_str_id_lock);
 201
 202 done:
 203         if (iffmid)
 204                 _FREE(iffmid, M_TEMP);
 205         return error;
 206 }