Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/lib/oid_registry.c

  1 /* ASN.1 Object identifier (OID) registry
  2  *
  3  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
  4  * Written by David Howells (dhowells@redhat.com)
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public Licence
  8  * as published by the Free Software Foundation; either version
  9  * 2 of the Licence, or (at your option) any later version.
 10  */
 11 
 12 #include <linux/module.h>
 13 #include <linux/export.h>
 14 #include <linux/oid_registry.h>
 15 #include <linux/kernel.h>
 16 #include <linux/errno.h>
 17 #include <linux/bug.h>
 18 #include "oid_registry_data.c"
 19 
 20 MODULE_DESCRIPTION("OID Registry");
 21 MODULE_AUTHOR("Red Hat, Inc.");
 22 MODULE_LICENSE("GPL");
 23 
 24 /**
 25  * look_up_OID - Find an OID registration for the specified data
 26  * @data: Binary representation of the OID
 27  * @datasize: Size of the binary representation
 28  */
 29 enum OID look_up_OID(const void *data, size_t datasize)
 30 {
 31         const unsigned char *octets = data;
 32         enum OID oid;
 33         unsigned char xhash;
 34         unsigned i, j, k, hash;
 35         size_t len;
 36 
 37         /* Hash the OID data */
 38         hash = datasize - 1;
 39 
 40         for (i = 0; i < datasize; i++)
 41                 hash += octets[i] * 33;
 42         hash = (hash >> 24) ^ (hash >> 16) ^ (hash >> 8) ^ hash;
 43         hash &= 0xff;
 44 
 45         /* Binary search the OID registry.  OIDs are stored in ascending order
 46          * of hash value then ascending order of size and then in ascending
 47          * order of reverse value.
 48          */
 49         i = 0;
 50         k = OID__NR;
 51         while (i < k) {
 52                 j = (i + k) / 2;
 53 
 54                 xhash = oid_search_table[j].hash;
 55                 if (xhash > hash) {
 56                         k = j;
 57                         continue;
 58                 }
 59                 if (xhash < hash) {
 60                         i = j + 1;
 61                         continue;
 62                 }
 63 
 64                 oid = oid_search_table[j].oid;
 65                 len = oid_index[oid + 1] - oid_index[oid];
 66                 if (len > datasize) {
 67                         k = j;
 68                         continue;
 69                 }
 70                 if (len < datasize) {
 71                         i = j + 1;
 72                         continue;
 73                 }
 74 
 75                 /* Variation is most likely to be at the tail end of the
 76                  * OID, so do the comparison in reverse.
 77                  */
 78                 while (len > 0) {
 79                         unsigned char a = oid_data[oid_index[oid] + --len];
 80                         unsigned char b = octets[len];
 81                         if (a > b) {
 82                                 k = j;
 83                                 goto next;
 84                         }
 85                         if (a < b) {
 86                                 i = j + 1;
 87                                 goto next;
 88                         }
 89                 }
 90                 return oid;
 91         next:
 92                 ;
 93         }
 94 
 95         return OID__NR;
 96 }
 97 EXPORT_SYMBOL_GPL(look_up_OID);
 98 
 99 /*
100  * sprint_OID - Print an Object Identifier into a buffer
101  * @data: The encoded OID to print
102  * @datasize: The size of the encoded OID
103  * @buffer: The buffer to render into
104  * @bufsize: The size of the buffer
105  *
106  * The OID is rendered into the buffer in "a.b.c.d" format and the number of
107  * bytes is returned.  -EBADMSG is returned if the data could not be intepreted
108  * and -ENOBUFS if the buffer was too small.
109  */
110 int sprint_oid(const void *data, size_t datasize, char *buffer, size_t bufsize)
111 {
112         const unsigned char *v = data, *end = v + datasize;
113         unsigned long num;
114         unsigned char n;
115         size_t ret;
116         int count;
117 
118         if (v >= end)
119                 return -EBADMSG;
120 
121         n = *v++;
122         ret = count = snprintf(buffer, bufsize, "%u.%u", n / 40, n % 40);
123         buffer += count;
124         bufsize -= count;
125         if (bufsize == 0)
126                 return -ENOBUFS;
127 
128         while (v < end) {
129                 num = 0;
130                 n = *v++;
131                 if (!(n & 0x80)) {
132                         num = n;
133                 } else {
134                         num = n & 0x7f;
135                         do {
136                                 if (v >= end)
137                                         return -EBADMSG;
138                                 n = *v++;
139                                 num <<= 7;
140                                 num |= n & 0x7f;
141                         } while (n & 0x80);
142                 }
143                 ret += count = snprintf(buffer, bufsize, ".%lu", num);
144                 buffer += count;
145                 bufsize -= count;
146                 if (bufsize == 0)
147                         return -ENOBUFS;
148         }
149 
150         return ret;
151 }
152 EXPORT_SYMBOL_GPL(sprint_oid);
153 
154 /**
155  * sprint_OID - Print an Object Identifier into a buffer
156  * @oid: The OID to print
157  * @buffer: The buffer to render into
158  * @bufsize: The size of the buffer
159  *
160  * The OID is rendered into the buffer in "a.b.c.d" format and the number of
161  * bytes is returned.
162  */
163 int sprint_OID(enum OID oid, char *buffer, size_t bufsize)
164 {
165         int ret;
166 
167         BUG_ON(oid >= OID__NR);
168 
169         ret = sprint_oid(oid_data + oid_index[oid],
170                          oid_index[oid + 1] - oid_index[oid],
171                          buffer, bufsize);
172         BUG_ON(ret == -EBADMSG);
173         return ret;
174 }
175 EXPORT_SYMBOL_GPL(sprint_OID);
176 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us