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
 109         *out_id = 0;
 110
 111         /* Look for an existing entry */
 112         lck_mtx_lock(net_str_id_lock);
 113         SLIST_FOREACH(entry, &net_str_id_list, nsi_next) {
 114                 if (strcmp(string, entry->nsi_string) == 0) {
 115                         break;
 116                 }
 117         }
 118
 119         if (entry == NULL) {
 120                 if (create == 0) {
 121                         lck_mtx_unlock(net_str_id_lock);
 122                         return ENOENT;
 123                 }
 124
 125                 entry = kalloc(NET_ID_STR_ENTRY_SIZE(string));
 126                 if (entry == NULL) {
 127                         lck_mtx_unlock(net_str_id_lock);
 128                         return ENOMEM;
 129                 }
 130
 131                 strlcpy(entry->nsi_string, string, strlen(string) + 1);
 132                 entry->nsi_flags = (1 << kind);
 133                 entry->nsi_id = nsi_next_id++;
 134                 nsi_kind_next[kind] = nsi_next_id;
 135                 SLIST_INSERT_HEAD(&net_str_id_list, entry, nsi_next);
 136         } else if ((entry->nsi_flags & (1 << kind)) == 0) {
 137                 if (create == 0) {
 138                         lck_mtx_unlock(net_str_id_lock);
 139                         return ENOENT;
 140                 }
 141                 entry->nsi_flags |= (1 << kind);
 142                 if (entry->nsi_id >= nsi_kind_next[kind]) {
 143                         nsi_kind_next[kind] = entry->nsi_id + 1;
 144                 }
 145         }
 146         lck_mtx_unlock(net_str_id_lock);
 147
 148         *out_id = entry->nsi_id;
 149
 150         return 0;
 151 }
 152
 153
 154 #define ROUNDUP32(a) \
 155         ((a) > 0 ? (1 + (((a) - 1) | (sizeof(uint32_t) - 1))) : sizeof(uint32_t))
 156
 157 int
 158 sysctl_if_family_ids SYSCTL_HANDLER_ARGS /* XXX bad syntax! */
 159 {
 160 #pragma unused(oidp)
 161 #pragma unused(arg1)
 162 #pragma unused(arg2)
 163         errno_t error = 0;
 164         struct net_str_id_entry *entry = NULL;
 165         struct if_family_id *iffmid = NULL;
 166         size_t max_size = 0;
 167
 168         lck_mtx_lock(net_str_id_lock);
 169         SLIST_FOREACH(entry, &net_str_id_list, nsi_next) {
 170                 size_t str_size;
 171                 size_t iffmid_size;
 172
 173                 if ((entry->nsi_flags & (1 << NSI_IF_FAM_ID)) == 0) {
 174                         continue;
 175                 }
 176
 177                 str_size = strlen(entry->nsi_string) + 1;
 178                 iffmid_size = ROUNDUP32(offsetof(struct net_str_id_entry, nsi_string) + str_size);
 179
 180                 if (iffmid_size > max_size) {
 181                         if (iffmid) {
 182                                 _FREE(iffmid, M_TEMP);
 183                         }
 184                         iffmid = _MALLOC(iffmid_size, M_TEMP, M_WAITOK);
 185                         if (iffmid == NULL) {
 186                                 lck_mtx_unlock(net_str_id_lock);
 187                                 error = ENOMEM;
 188                                 goto done;
 189                         }
 190                         max_size = iffmid_size;
 191                 }
 192
 193                 bzero(iffmid, iffmid_size);
 194                 iffmid->iffmid_len = iffmid_size;
 195                 iffmid->iffmid_id = entry->nsi_id;
 196                 strlcpy(iffmid->iffmid_str, entry->nsi_string, str_size);
 197                 error = SYSCTL_OUT(req, iffmid, iffmid_size);
 198                 if (error) {
 199                         lck_mtx_unlock(net_str_id_lock);
 200                         goto done;
 201                 }
 202         }
 203         lck_mtx_unlock(net_str_id_lock);
 204
 205 done:
 206         if (iffmid) {
 207                 _FREE(iffmid, M_TEMP);
 208         }
 209         return error;
 210 }