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NetServices/lwip/core/snmp/asn1_dec.c@0:05ccbd4f84f1, 2013-12-02 (annotated)

Committer:
hendrikvincent
Date:
Mon Dec 02 09:01:23 2013 +0000
Revision:
0:05ccbd4f84f1
eerste programma;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hendrikvincent 0:05ccbd4f84f1 1 /**
hendrikvincent 0:05ccbd4f84f1 2 * @file
hendrikvincent 0:05ccbd4f84f1 3 * Abstract Syntax Notation One (ISO 8824, 8825) decoding
hendrikvincent 0:05ccbd4f84f1 4 *
hendrikvincent 0:05ccbd4f84f1 5 * @todo not optimised (yet), favor correctness over speed, favor speed over size
hendrikvincent 0:05ccbd4f84f1 6 */
hendrikvincent 0:05ccbd4f84f1 7
hendrikvincent 0:05ccbd4f84f1 8 /*
hendrikvincent 0:05ccbd4f84f1 9 * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
hendrikvincent 0:05ccbd4f84f1 10 * All rights reserved.
hendrikvincent 0:05ccbd4f84f1 11 *
hendrikvincent 0:05ccbd4f84f1 12 * Redistribution and use in source and binary forms, with or without modification,
hendrikvincent 0:05ccbd4f84f1 13 * are permitted provided that the following conditions are met:
hendrikvincent 0:05ccbd4f84f1 14 *
hendrikvincent 0:05ccbd4f84f1 15 * 1. Redistributions of source code must retain the above copyright notice,
hendrikvincent 0:05ccbd4f84f1 16 * this list of conditions and the following disclaimer.
hendrikvincent 0:05ccbd4f84f1 17 * 2. Redistributions in binary form must reproduce the above copyright notice,
hendrikvincent 0:05ccbd4f84f1 18 * this list of conditions and the following disclaimer in the documentation
hendrikvincent 0:05ccbd4f84f1 19 * and/or other materials provided with the distribution.
hendrikvincent 0:05ccbd4f84f1 20 * 3. The name of the author may not be used to endorse or promote products
hendrikvincent 0:05ccbd4f84f1 21 * derived from this software without specific prior written permission.
hendrikvincent 0:05ccbd4f84f1 22 *
hendrikvincent 0:05ccbd4f84f1 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
hendrikvincent 0:05ccbd4f84f1 24 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
hendrikvincent 0:05ccbd4f84f1 25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
hendrikvincent 0:05ccbd4f84f1 26 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
hendrikvincent 0:05ccbd4f84f1 27 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
hendrikvincent 0:05ccbd4f84f1 28 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
hendrikvincent 0:05ccbd4f84f1 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
hendrikvincent 0:05ccbd4f84f1 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
hendrikvincent 0:05ccbd4f84f1 31 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
hendrikvincent 0:05ccbd4f84f1 32 * OF SUCH DAMAGE.
hendrikvincent 0:05ccbd4f84f1 33 *
hendrikvincent 0:05ccbd4f84f1 34 * Author: Christiaan Simons <christiaan.simons@axon.tv>
hendrikvincent 0:05ccbd4f84f1 35 */
hendrikvincent 0:05ccbd4f84f1 36
hendrikvincent 0:05ccbd4f84f1 37 #include "lwip/opt.h"
hendrikvincent 0:05ccbd4f84f1 38
hendrikvincent 0:05ccbd4f84f1 39 #if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
hendrikvincent 0:05ccbd4f84f1 40
hendrikvincent 0:05ccbd4f84f1 41 #include "lwip/snmp_asn1.h"
hendrikvincent 0:05ccbd4f84f1 42
hendrikvincent 0:05ccbd4f84f1 43 /**
hendrikvincent 0:05ccbd4f84f1 44 * Retrieves type field from incoming pbuf chain.
hendrikvincent 0:05ccbd4f84f1 45 *
hendrikvincent 0:05ccbd4f84f1 46 * @param p points to a pbuf holding an ASN1 coded type field
hendrikvincent 0:05ccbd4f84f1 47 * @param ofs points to the offset within the pbuf chain of the ASN1 coded type field
hendrikvincent 0:05ccbd4f84f1 48 * @param type return ASN1 type
hendrikvincent 0:05ccbd4f84f1 49 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode
hendrikvincent 0:05ccbd4f84f1 50 */
hendrikvincent 0:05ccbd4f84f1 51 err_t
hendrikvincent 0:05ccbd4f84f1 52 snmp_asn1_dec_type(struct pbuf *p, u16_t ofs, u8_t *type)
hendrikvincent 0:05ccbd4f84f1 53 {
hendrikvincent 0:05ccbd4f84f1 54 u16_t plen, base;
hendrikvincent 0:05ccbd4f84f1 55 u8_t *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 56
hendrikvincent 0:05ccbd4f84f1 57 plen = 0;
hendrikvincent 0:05ccbd4f84f1 58 while (p != NULL)
hendrikvincent 0:05ccbd4f84f1 59 {
hendrikvincent 0:05ccbd4f84f1 60 base = plen;
hendrikvincent 0:05ccbd4f84f1 61 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 62 if (ofs < plen)
hendrikvincent 0:05ccbd4f84f1 63 {
hendrikvincent 0:05ccbd4f84f1 64 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 65 msg_ptr += ofs - base;
hendrikvincent 0:05ccbd4f84f1 66 *type = *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 67 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 68 }
hendrikvincent 0:05ccbd4f84f1 69 p = p->next;
hendrikvincent 0:05ccbd4f84f1 70 }
hendrikvincent 0:05ccbd4f84f1 71 /* p == NULL, ofs >= plen */
hendrikvincent 0:05ccbd4f84f1 72 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 73 }
hendrikvincent 0:05ccbd4f84f1 74
hendrikvincent 0:05ccbd4f84f1 75 /**
hendrikvincent 0:05ccbd4f84f1 76 * Decodes length field from incoming pbuf chain into host length.
hendrikvincent 0:05ccbd4f84f1 77 *
hendrikvincent 0:05ccbd4f84f1 78 * @param p points to a pbuf holding an ASN1 coded length
hendrikvincent 0:05ccbd4f84f1 79 * @param ofs points to the offset within the pbuf chain of the ASN1 coded length
hendrikvincent 0:05ccbd4f84f1 80 * @param octets_used returns number of octets used by the length code
hendrikvincent 0:05ccbd4f84f1 81 * @param length return host order length, upto 64k
hendrikvincent 0:05ccbd4f84f1 82 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode
hendrikvincent 0:05ccbd4f84f1 83 */
hendrikvincent 0:05ccbd4f84f1 84 err_t
hendrikvincent 0:05ccbd4f84f1 85 snmp_asn1_dec_length(struct pbuf *p, u16_t ofs, u8_t *octets_used, u16_t *length)
hendrikvincent 0:05ccbd4f84f1 86 {
hendrikvincent 0:05ccbd4f84f1 87 u16_t plen, base;
hendrikvincent 0:05ccbd4f84f1 88 u8_t *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 89
hendrikvincent 0:05ccbd4f84f1 90 plen = 0;
hendrikvincent 0:05ccbd4f84f1 91 while (p != NULL)
hendrikvincent 0:05ccbd4f84f1 92 {
hendrikvincent 0:05ccbd4f84f1 93 base = plen;
hendrikvincent 0:05ccbd4f84f1 94 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 95 if (ofs < plen)
hendrikvincent 0:05ccbd4f84f1 96 {
hendrikvincent 0:05ccbd4f84f1 97 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 98 msg_ptr += ofs - base;
hendrikvincent 0:05ccbd4f84f1 99
hendrikvincent 0:05ccbd4f84f1 100 if (*msg_ptr < 0x80)
hendrikvincent 0:05ccbd4f84f1 101 {
hendrikvincent 0:05ccbd4f84f1 102 /* primitive definite length format */
hendrikvincent 0:05ccbd4f84f1 103 *octets_used = 1;
hendrikvincent 0:05ccbd4f84f1 104 *length = *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 105 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 106 }
hendrikvincent 0:05ccbd4f84f1 107 else if (*msg_ptr == 0x80)
hendrikvincent 0:05ccbd4f84f1 108 {
hendrikvincent 0:05ccbd4f84f1 109 /* constructed indefinite length format, termination with two zero octets */
hendrikvincent 0:05ccbd4f84f1 110 u8_t zeros;
hendrikvincent 0:05ccbd4f84f1 111 u8_t i;
hendrikvincent 0:05ccbd4f84f1 112
hendrikvincent 0:05ccbd4f84f1 113 *length = 0;
hendrikvincent 0:05ccbd4f84f1 114 zeros = 0;
hendrikvincent 0:05ccbd4f84f1 115 while (zeros != 2)
hendrikvincent 0:05ccbd4f84f1 116 {
hendrikvincent 0:05ccbd4f84f1 117 i = 2;
hendrikvincent 0:05ccbd4f84f1 118 while (i > 0)
hendrikvincent 0:05ccbd4f84f1 119 {
hendrikvincent 0:05ccbd4f84f1 120 i--;
hendrikvincent 0:05ccbd4f84f1 121 (*length) += 1;
hendrikvincent 0:05ccbd4f84f1 122 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 123 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 124 {
hendrikvincent 0:05ccbd4f84f1 125 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 126 p = p->next;
hendrikvincent 0:05ccbd4f84f1 127 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 128 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 129 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 130 }
hendrikvincent 0:05ccbd4f84f1 131 else
hendrikvincent 0:05ccbd4f84f1 132 {
hendrikvincent 0:05ccbd4f84f1 133 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 134 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 135 }
hendrikvincent 0:05ccbd4f84f1 136 if (*msg_ptr == 0)
hendrikvincent 0:05ccbd4f84f1 137 {
hendrikvincent 0:05ccbd4f84f1 138 zeros++;
hendrikvincent 0:05ccbd4f84f1 139 if (zeros == 2)
hendrikvincent 0:05ccbd4f84f1 140 {
hendrikvincent 0:05ccbd4f84f1 141 /* stop while (i > 0) */
hendrikvincent 0:05ccbd4f84f1 142 i = 0;
hendrikvincent 0:05ccbd4f84f1 143 }
hendrikvincent 0:05ccbd4f84f1 144 }
hendrikvincent 0:05ccbd4f84f1 145 else
hendrikvincent 0:05ccbd4f84f1 146 {
hendrikvincent 0:05ccbd4f84f1 147 zeros = 0;
hendrikvincent 0:05ccbd4f84f1 148 }
hendrikvincent 0:05ccbd4f84f1 149 }
hendrikvincent 0:05ccbd4f84f1 150 }
hendrikvincent 0:05ccbd4f84f1 151 *octets_used = 1;
hendrikvincent 0:05ccbd4f84f1 152 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 153 }
hendrikvincent 0:05ccbd4f84f1 154 else if (*msg_ptr == 0x81)
hendrikvincent 0:05ccbd4f84f1 155 {
hendrikvincent 0:05ccbd4f84f1 156 /* constructed definite length format, one octet */
hendrikvincent 0:05ccbd4f84f1 157 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 158 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 159 {
hendrikvincent 0:05ccbd4f84f1 160 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 161 p = p->next;
hendrikvincent 0:05ccbd4f84f1 162 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 163 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 164 }
hendrikvincent 0:05ccbd4f84f1 165 else
hendrikvincent 0:05ccbd4f84f1 166 {
hendrikvincent 0:05ccbd4f84f1 167 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 168 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 169 }
hendrikvincent 0:05ccbd4f84f1 170 *length = *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 171 *octets_used = 2;
hendrikvincent 0:05ccbd4f84f1 172 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 173 }
hendrikvincent 0:05ccbd4f84f1 174 else if (*msg_ptr == 0x82)
hendrikvincent 0:05ccbd4f84f1 175 {
hendrikvincent 0:05ccbd4f84f1 176 u8_t i;
hendrikvincent 0:05ccbd4f84f1 177
hendrikvincent 0:05ccbd4f84f1 178 /* constructed definite length format, two octets */
hendrikvincent 0:05ccbd4f84f1 179 i = 2;
hendrikvincent 0:05ccbd4f84f1 180 while (i > 0)
hendrikvincent 0:05ccbd4f84f1 181 {
hendrikvincent 0:05ccbd4f84f1 182 i--;
hendrikvincent 0:05ccbd4f84f1 183 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 184 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 185 {
hendrikvincent 0:05ccbd4f84f1 186 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 187 p = p->next;
hendrikvincent 0:05ccbd4f84f1 188 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 189 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 190 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 191 }
hendrikvincent 0:05ccbd4f84f1 192 else
hendrikvincent 0:05ccbd4f84f1 193 {
hendrikvincent 0:05ccbd4f84f1 194 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 195 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 196 }
hendrikvincent 0:05ccbd4f84f1 197 if (i == 0)
hendrikvincent 0:05ccbd4f84f1 198 {
hendrikvincent 0:05ccbd4f84f1 199 /* least significant length octet */
hendrikvincent 0:05ccbd4f84f1 200 *length |= *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 201 }
hendrikvincent 0:05ccbd4f84f1 202 else
hendrikvincent 0:05ccbd4f84f1 203 {
hendrikvincent 0:05ccbd4f84f1 204 /* most significant length octet */
hendrikvincent 0:05ccbd4f84f1 205 *length = (*msg_ptr) << 8;
hendrikvincent 0:05ccbd4f84f1 206 }
hendrikvincent 0:05ccbd4f84f1 207 }
hendrikvincent 0:05ccbd4f84f1 208 *octets_used = 3;
hendrikvincent 0:05ccbd4f84f1 209 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 210 }
hendrikvincent 0:05ccbd4f84f1 211 else
hendrikvincent 0:05ccbd4f84f1 212 {
hendrikvincent 0:05ccbd4f84f1 213 /* constructed definite length format 3..127 octets, this is too big (>64k) */
hendrikvincent 0:05ccbd4f84f1 214 /** @todo: do we need to accept inefficient codings with many leading zero's? */
hendrikvincent 0:05ccbd4f84f1 215 *octets_used = 1 + ((*msg_ptr) & 0x7f);
hendrikvincent 0:05ccbd4f84f1 216 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 217 }
hendrikvincent 0:05ccbd4f84f1 218 }
hendrikvincent 0:05ccbd4f84f1 219 p = p->next;
hendrikvincent 0:05ccbd4f84f1 220 }
hendrikvincent 0:05ccbd4f84f1 221
hendrikvincent 0:05ccbd4f84f1 222 /* p == NULL, ofs >= plen */
hendrikvincent 0:05ccbd4f84f1 223 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 224 }
hendrikvincent 0:05ccbd4f84f1 225
hendrikvincent 0:05ccbd4f84f1 226 /**
hendrikvincent 0:05ccbd4f84f1 227 * Decodes positive integer (counter, gauge, timeticks) into u32_t.
hendrikvincent 0:05ccbd4f84f1 228 *
hendrikvincent 0:05ccbd4f84f1 229 * @param p points to a pbuf holding an ASN1 coded integer
hendrikvincent 0:05ccbd4f84f1 230 * @param ofs points to the offset within the pbuf chain of the ASN1 coded integer
hendrikvincent 0:05ccbd4f84f1 231 * @param len length of the coded integer field
hendrikvincent 0:05ccbd4f84f1 232 * @param value return host order integer
hendrikvincent 0:05ccbd4f84f1 233 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode
hendrikvincent 0:05ccbd4f84f1 234 *
hendrikvincent 0:05ccbd4f84f1 235 * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded
hendrikvincent 0:05ccbd4f84f1 236 * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value
hendrikvincent 0:05ccbd4f84f1 237 * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!!
hendrikvincent 0:05ccbd4f84f1 238 */
hendrikvincent 0:05ccbd4f84f1 239 err_t
hendrikvincent 0:05ccbd4f84f1 240 snmp_asn1_dec_u32t(struct pbuf *p, u16_t ofs, u16_t len, u32_t *value)
hendrikvincent 0:05ccbd4f84f1 241 {
hendrikvincent 0:05ccbd4f84f1 242 u16_t plen, base;
hendrikvincent 0:05ccbd4f84f1 243 u8_t *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 244
hendrikvincent 0:05ccbd4f84f1 245 plen = 0;
hendrikvincent 0:05ccbd4f84f1 246 while (p != NULL)
hendrikvincent 0:05ccbd4f84f1 247 {
hendrikvincent 0:05ccbd4f84f1 248 base = plen;
hendrikvincent 0:05ccbd4f84f1 249 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 250 if (ofs < plen)
hendrikvincent 0:05ccbd4f84f1 251 {
hendrikvincent 0:05ccbd4f84f1 252 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 253 msg_ptr += ofs - base;
hendrikvincent 0:05ccbd4f84f1 254 if ((len > 0) && (len < 6))
hendrikvincent 0:05ccbd4f84f1 255 {
hendrikvincent 0:05ccbd4f84f1 256 /* start from zero */
hendrikvincent 0:05ccbd4f84f1 257 *value = 0;
hendrikvincent 0:05ccbd4f84f1 258 if (*msg_ptr & 0x80)
hendrikvincent 0:05ccbd4f84f1 259 {
hendrikvincent 0:05ccbd4f84f1 260 /* negative, expecting zero sign bit! */
hendrikvincent 0:05ccbd4f84f1 261 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 262 }
hendrikvincent 0:05ccbd4f84f1 263 else
hendrikvincent 0:05ccbd4f84f1 264 {
hendrikvincent 0:05ccbd4f84f1 265 /* positive */
hendrikvincent 0:05ccbd4f84f1 266 if ((len > 1) && (*msg_ptr == 0))
hendrikvincent 0:05ccbd4f84f1 267 {
hendrikvincent 0:05ccbd4f84f1 268 /* skip leading "sign byte" octet 0x00 */
hendrikvincent 0:05ccbd4f84f1 269 len--;
hendrikvincent 0:05ccbd4f84f1 270 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 271 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 272 {
hendrikvincent 0:05ccbd4f84f1 273 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 274 p = p->next;
hendrikvincent 0:05ccbd4f84f1 275 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 276 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 277 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 278 }
hendrikvincent 0:05ccbd4f84f1 279 else
hendrikvincent 0:05ccbd4f84f1 280 {
hendrikvincent 0:05ccbd4f84f1 281 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 282 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 283 }
hendrikvincent 0:05ccbd4f84f1 284 }
hendrikvincent 0:05ccbd4f84f1 285 }
hendrikvincent 0:05ccbd4f84f1 286 /* OR octets with value */
hendrikvincent 0:05ccbd4f84f1 287 while (len > 1)
hendrikvincent 0:05ccbd4f84f1 288 {
hendrikvincent 0:05ccbd4f84f1 289 len--;
hendrikvincent 0:05ccbd4f84f1 290 *value |= *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 291 *value <<= 8;
hendrikvincent 0:05ccbd4f84f1 292 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 293 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 294 {
hendrikvincent 0:05ccbd4f84f1 295 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 296 p = p->next;
hendrikvincent 0:05ccbd4f84f1 297 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 298 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 299 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 300 }
hendrikvincent 0:05ccbd4f84f1 301 else
hendrikvincent 0:05ccbd4f84f1 302 {
hendrikvincent 0:05ccbd4f84f1 303 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 304 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 305 }
hendrikvincent 0:05ccbd4f84f1 306 }
hendrikvincent 0:05ccbd4f84f1 307 *value |= *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 308 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 309 }
hendrikvincent 0:05ccbd4f84f1 310 else
hendrikvincent 0:05ccbd4f84f1 311 {
hendrikvincent 0:05ccbd4f84f1 312 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 313 }
hendrikvincent 0:05ccbd4f84f1 314 }
hendrikvincent 0:05ccbd4f84f1 315 p = p->next;
hendrikvincent 0:05ccbd4f84f1 316 }
hendrikvincent 0:05ccbd4f84f1 317 /* p == NULL, ofs >= plen */
hendrikvincent 0:05ccbd4f84f1 318 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 319 }
hendrikvincent 0:05ccbd4f84f1 320
hendrikvincent 0:05ccbd4f84f1 321 /**
hendrikvincent 0:05ccbd4f84f1 322 * Decodes integer into s32_t.
hendrikvincent 0:05ccbd4f84f1 323 *
hendrikvincent 0:05ccbd4f84f1 324 * @param p points to a pbuf holding an ASN1 coded integer
hendrikvincent 0:05ccbd4f84f1 325 * @param ofs points to the offset within the pbuf chain of the ASN1 coded integer
hendrikvincent 0:05ccbd4f84f1 326 * @param len length of the coded integer field
hendrikvincent 0:05ccbd4f84f1 327 * @param value return host order integer
hendrikvincent 0:05ccbd4f84f1 328 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode
hendrikvincent 0:05ccbd4f84f1 329 *
hendrikvincent 0:05ccbd4f84f1 330 * @note ASN coded integers are _always_ signed!
hendrikvincent 0:05ccbd4f84f1 331 */
hendrikvincent 0:05ccbd4f84f1 332 err_t
hendrikvincent 0:05ccbd4f84f1 333 snmp_asn1_dec_s32t(struct pbuf *p, u16_t ofs, u16_t len, s32_t *value)
hendrikvincent 0:05ccbd4f84f1 334 {
hendrikvincent 0:05ccbd4f84f1 335 u16_t plen, base;
hendrikvincent 0:05ccbd4f84f1 336 u8_t *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 337 #if BYTE_ORDER == LITTLE_ENDIAN
hendrikvincent 0:05ccbd4f84f1 338 u8_t *lsb_ptr = (u8_t*)value;
hendrikvincent 0:05ccbd4f84f1 339 #endif
hendrikvincent 0:05ccbd4f84f1 340 #if BYTE_ORDER == BIG_ENDIAN
hendrikvincent 0:05ccbd4f84f1 341 u8_t *lsb_ptr = (u8_t*)value + sizeof(s32_t) - 1;
hendrikvincent 0:05ccbd4f84f1 342 #endif
hendrikvincent 0:05ccbd4f84f1 343 u8_t sign;
hendrikvincent 0:05ccbd4f84f1 344
hendrikvincent 0:05ccbd4f84f1 345 plen = 0;
hendrikvincent 0:05ccbd4f84f1 346 while (p != NULL)
hendrikvincent 0:05ccbd4f84f1 347 {
hendrikvincent 0:05ccbd4f84f1 348 base = plen;
hendrikvincent 0:05ccbd4f84f1 349 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 350 if (ofs < plen)
hendrikvincent 0:05ccbd4f84f1 351 {
hendrikvincent 0:05ccbd4f84f1 352 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 353 msg_ptr += ofs - base;
hendrikvincent 0:05ccbd4f84f1 354 if ((len > 0) && (len < 5))
hendrikvincent 0:05ccbd4f84f1 355 {
hendrikvincent 0:05ccbd4f84f1 356 if (*msg_ptr & 0x80)
hendrikvincent 0:05ccbd4f84f1 357 {
hendrikvincent 0:05ccbd4f84f1 358 /* negative, start from -1 */
hendrikvincent 0:05ccbd4f84f1 359 *value = -1;
hendrikvincent 0:05ccbd4f84f1 360 sign = 1;
hendrikvincent 0:05ccbd4f84f1 361 }
hendrikvincent 0:05ccbd4f84f1 362 else
hendrikvincent 0:05ccbd4f84f1 363 {
hendrikvincent 0:05ccbd4f84f1 364 /* positive, start from 0 */
hendrikvincent 0:05ccbd4f84f1 365 *value = 0;
hendrikvincent 0:05ccbd4f84f1 366 sign = 0;
hendrikvincent 0:05ccbd4f84f1 367 }
hendrikvincent 0:05ccbd4f84f1 368 /* OR/AND octets with value */
hendrikvincent 0:05ccbd4f84f1 369 while (len > 1)
hendrikvincent 0:05ccbd4f84f1 370 {
hendrikvincent 0:05ccbd4f84f1 371 len--;
hendrikvincent 0:05ccbd4f84f1 372 if (sign)
hendrikvincent 0:05ccbd4f84f1 373 {
hendrikvincent 0:05ccbd4f84f1 374 *lsb_ptr &= *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 375 *value <<= 8;
hendrikvincent 0:05ccbd4f84f1 376 *lsb_ptr |= 255;
hendrikvincent 0:05ccbd4f84f1 377 }
hendrikvincent 0:05ccbd4f84f1 378 else
hendrikvincent 0:05ccbd4f84f1 379 {
hendrikvincent 0:05ccbd4f84f1 380 *lsb_ptr |= *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 381 *value <<= 8;
hendrikvincent 0:05ccbd4f84f1 382 }
hendrikvincent 0:05ccbd4f84f1 383 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 384 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 385 {
hendrikvincent 0:05ccbd4f84f1 386 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 387 p = p->next;
hendrikvincent 0:05ccbd4f84f1 388 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 389 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 390 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 391 }
hendrikvincent 0:05ccbd4f84f1 392 else
hendrikvincent 0:05ccbd4f84f1 393 {
hendrikvincent 0:05ccbd4f84f1 394 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 395 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 396 }
hendrikvincent 0:05ccbd4f84f1 397 }
hendrikvincent 0:05ccbd4f84f1 398 if (sign)
hendrikvincent 0:05ccbd4f84f1 399 {
hendrikvincent 0:05ccbd4f84f1 400 *lsb_ptr &= *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 401 }
hendrikvincent 0:05ccbd4f84f1 402 else
hendrikvincent 0:05ccbd4f84f1 403 {
hendrikvincent 0:05ccbd4f84f1 404 *lsb_ptr |= *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 405 }
hendrikvincent 0:05ccbd4f84f1 406 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 407 }
hendrikvincent 0:05ccbd4f84f1 408 else
hendrikvincent 0:05ccbd4f84f1 409 {
hendrikvincent 0:05ccbd4f84f1 410 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 411 }
hendrikvincent 0:05ccbd4f84f1 412 }
hendrikvincent 0:05ccbd4f84f1 413 p = p->next;
hendrikvincent 0:05ccbd4f84f1 414 }
hendrikvincent 0:05ccbd4f84f1 415 /* p == NULL, ofs >= plen */
hendrikvincent 0:05ccbd4f84f1 416 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 417 }
hendrikvincent 0:05ccbd4f84f1 418
hendrikvincent 0:05ccbd4f84f1 419 /**
hendrikvincent 0:05ccbd4f84f1 420 * Decodes object identifier from incoming message into array of s32_t.
hendrikvincent 0:05ccbd4f84f1 421 *
hendrikvincent 0:05ccbd4f84f1 422 * @param p points to a pbuf holding an ASN1 coded object identifier
hendrikvincent 0:05ccbd4f84f1 423 * @param ofs points to the offset within the pbuf chain of the ASN1 coded object identifier
hendrikvincent 0:05ccbd4f84f1 424 * @param len length of the coded object identifier
hendrikvincent 0:05ccbd4f84f1 425 * @param oid return object identifier struct
hendrikvincent 0:05ccbd4f84f1 426 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode
hendrikvincent 0:05ccbd4f84f1 427 */
hendrikvincent 0:05ccbd4f84f1 428 err_t
hendrikvincent 0:05ccbd4f84f1 429 snmp_asn1_dec_oid(struct pbuf *p, u16_t ofs, u16_t len, struct snmp_obj_id *oid)
hendrikvincent 0:05ccbd4f84f1 430 {
hendrikvincent 0:05ccbd4f84f1 431 u16_t plen, base;
hendrikvincent 0:05ccbd4f84f1 432 u8_t *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 433 s32_t *oid_ptr;
hendrikvincent 0:05ccbd4f84f1 434
hendrikvincent 0:05ccbd4f84f1 435 plen = 0;
hendrikvincent 0:05ccbd4f84f1 436 while (p != NULL)
hendrikvincent 0:05ccbd4f84f1 437 {
hendrikvincent 0:05ccbd4f84f1 438 base = plen;
hendrikvincent 0:05ccbd4f84f1 439 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 440 if (ofs < plen)
hendrikvincent 0:05ccbd4f84f1 441 {
hendrikvincent 0:05ccbd4f84f1 442 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 443 msg_ptr += ofs - base;
hendrikvincent 0:05ccbd4f84f1 444
hendrikvincent 0:05ccbd4f84f1 445 oid->len = 0;
hendrikvincent 0:05ccbd4f84f1 446 oid_ptr = &oid->id[0];
hendrikvincent 0:05ccbd4f84f1 447 if (len > 0)
hendrikvincent 0:05ccbd4f84f1 448 {
hendrikvincent 0:05ccbd4f84f1 449 /* first compressed octet */
hendrikvincent 0:05ccbd4f84f1 450 if (*msg_ptr == 0x2B)
hendrikvincent 0:05ccbd4f84f1 451 {
hendrikvincent 0:05ccbd4f84f1 452 /* (most) common case 1.3 (iso.org) */
hendrikvincent 0:05ccbd4f84f1 453 *oid_ptr = 1;
hendrikvincent 0:05ccbd4f84f1 454 oid_ptr++;
hendrikvincent 0:05ccbd4f84f1 455 *oid_ptr = 3;
hendrikvincent 0:05ccbd4f84f1 456 oid_ptr++;
hendrikvincent 0:05ccbd4f84f1 457 }
hendrikvincent 0:05ccbd4f84f1 458 else if (*msg_ptr < 40)
hendrikvincent 0:05ccbd4f84f1 459 {
hendrikvincent 0:05ccbd4f84f1 460 *oid_ptr = 0;
hendrikvincent 0:05ccbd4f84f1 461 oid_ptr++;
hendrikvincent 0:05ccbd4f84f1 462 *oid_ptr = *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 463 oid_ptr++;
hendrikvincent 0:05ccbd4f84f1 464 }
hendrikvincent 0:05ccbd4f84f1 465 else if (*msg_ptr < 80)
hendrikvincent 0:05ccbd4f84f1 466 {
hendrikvincent 0:05ccbd4f84f1 467 *oid_ptr = 1;
hendrikvincent 0:05ccbd4f84f1 468 oid_ptr++;
hendrikvincent 0:05ccbd4f84f1 469 *oid_ptr = (*msg_ptr) - 40;
hendrikvincent 0:05ccbd4f84f1 470 oid_ptr++;
hendrikvincent 0:05ccbd4f84f1 471 }
hendrikvincent 0:05ccbd4f84f1 472 else
hendrikvincent 0:05ccbd4f84f1 473 {
hendrikvincent 0:05ccbd4f84f1 474 *oid_ptr = 2;
hendrikvincent 0:05ccbd4f84f1 475 oid_ptr++;
hendrikvincent 0:05ccbd4f84f1 476 *oid_ptr = (*msg_ptr) - 80;
hendrikvincent 0:05ccbd4f84f1 477 oid_ptr++;
hendrikvincent 0:05ccbd4f84f1 478 }
hendrikvincent 0:05ccbd4f84f1 479 oid->len = 2;
hendrikvincent 0:05ccbd4f84f1 480 }
hendrikvincent 0:05ccbd4f84f1 481 else
hendrikvincent 0:05ccbd4f84f1 482 {
hendrikvincent 0:05ccbd4f84f1 483 /* accepting zero length identifiers e.g. for
hendrikvincent 0:05ccbd4f84f1 484 getnext operation. uncommon but valid */
hendrikvincent 0:05ccbd4f84f1 485 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 486 }
hendrikvincent 0:05ccbd4f84f1 487 len--;
hendrikvincent 0:05ccbd4f84f1 488 if (len > 0)
hendrikvincent 0:05ccbd4f84f1 489 {
hendrikvincent 0:05ccbd4f84f1 490 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 491 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 492 {
hendrikvincent 0:05ccbd4f84f1 493 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 494 p = p->next;
hendrikvincent 0:05ccbd4f84f1 495 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 496 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 497 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 498 }
hendrikvincent 0:05ccbd4f84f1 499 else
hendrikvincent 0:05ccbd4f84f1 500 {
hendrikvincent 0:05ccbd4f84f1 501 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 502 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 503 }
hendrikvincent 0:05ccbd4f84f1 504 }
hendrikvincent 0:05ccbd4f84f1 505 while ((len > 0) && (oid->len < LWIP_SNMP_OBJ_ID_LEN))
hendrikvincent 0:05ccbd4f84f1 506 {
hendrikvincent 0:05ccbd4f84f1 507 /* sub-identifier uses multiple octets */
hendrikvincent 0:05ccbd4f84f1 508 if (*msg_ptr & 0x80)
hendrikvincent 0:05ccbd4f84f1 509 {
hendrikvincent 0:05ccbd4f84f1 510 s32_t sub_id = 0;
hendrikvincent 0:05ccbd4f84f1 511
hendrikvincent 0:05ccbd4f84f1 512 while ((*msg_ptr & 0x80) && (len > 1))
hendrikvincent 0:05ccbd4f84f1 513 {
hendrikvincent 0:05ccbd4f84f1 514 len--;
hendrikvincent 0:05ccbd4f84f1 515 sub_id = (sub_id << 7) + (*msg_ptr & ~0x80);
hendrikvincent 0:05ccbd4f84f1 516 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 517 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 518 {
hendrikvincent 0:05ccbd4f84f1 519 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 520 p = p->next;
hendrikvincent 0:05ccbd4f84f1 521 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 522 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 523 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 524 }
hendrikvincent 0:05ccbd4f84f1 525 else
hendrikvincent 0:05ccbd4f84f1 526 {
hendrikvincent 0:05ccbd4f84f1 527 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 528 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 529 }
hendrikvincent 0:05ccbd4f84f1 530 }
hendrikvincent 0:05ccbd4f84f1 531 if (!(*msg_ptr & 0x80) && (len > 0))
hendrikvincent 0:05ccbd4f84f1 532 {
hendrikvincent 0:05ccbd4f84f1 533 /* last octet sub-identifier */
hendrikvincent 0:05ccbd4f84f1 534 len--;
hendrikvincent 0:05ccbd4f84f1 535 sub_id = (sub_id << 7) + *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 536 *oid_ptr = sub_id;
hendrikvincent 0:05ccbd4f84f1 537 }
hendrikvincent 0:05ccbd4f84f1 538 }
hendrikvincent 0:05ccbd4f84f1 539 else
hendrikvincent 0:05ccbd4f84f1 540 {
hendrikvincent 0:05ccbd4f84f1 541 /* !(*msg_ptr & 0x80) sub-identifier uses single octet */
hendrikvincent 0:05ccbd4f84f1 542 len--;
hendrikvincent 0:05ccbd4f84f1 543 *oid_ptr = *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 544 }
hendrikvincent 0:05ccbd4f84f1 545 if (len > 0)
hendrikvincent 0:05ccbd4f84f1 546 {
hendrikvincent 0:05ccbd4f84f1 547 /* remaining oid bytes available ... */
hendrikvincent 0:05ccbd4f84f1 548 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 549 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 550 {
hendrikvincent 0:05ccbd4f84f1 551 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 552 p = p->next;
hendrikvincent 0:05ccbd4f84f1 553 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 554 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 555 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 556 }
hendrikvincent 0:05ccbd4f84f1 557 else
hendrikvincent 0:05ccbd4f84f1 558 {
hendrikvincent 0:05ccbd4f84f1 559 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 560 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 561 }
hendrikvincent 0:05ccbd4f84f1 562 }
hendrikvincent 0:05ccbd4f84f1 563 oid_ptr++;
hendrikvincent 0:05ccbd4f84f1 564 oid->len++;
hendrikvincent 0:05ccbd4f84f1 565 }
hendrikvincent 0:05ccbd4f84f1 566 if (len == 0)
hendrikvincent 0:05ccbd4f84f1 567 {
hendrikvincent 0:05ccbd4f84f1 568 /* len == 0, end of oid */
hendrikvincent 0:05ccbd4f84f1 569 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 570 }
hendrikvincent 0:05ccbd4f84f1 571 else
hendrikvincent 0:05ccbd4f84f1 572 {
hendrikvincent 0:05ccbd4f84f1 573 /* len > 0, oid->len == LWIP_SNMP_OBJ_ID_LEN or malformed encoding */
hendrikvincent 0:05ccbd4f84f1 574 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 575 }
hendrikvincent 0:05ccbd4f84f1 576
hendrikvincent 0:05ccbd4f84f1 577 }
hendrikvincent 0:05ccbd4f84f1 578 p = p->next;
hendrikvincent 0:05ccbd4f84f1 579 }
hendrikvincent 0:05ccbd4f84f1 580 /* p == NULL, ofs >= plen */
hendrikvincent 0:05ccbd4f84f1 581 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 582 }
hendrikvincent 0:05ccbd4f84f1 583
hendrikvincent 0:05ccbd4f84f1 584 /**
hendrikvincent 0:05ccbd4f84f1 585 * Decodes (copies) raw data (ip-addresses, octet strings, opaque encoding)
hendrikvincent 0:05ccbd4f84f1 586 * from incoming message into array.
hendrikvincent 0:05ccbd4f84f1 587 *
hendrikvincent 0:05ccbd4f84f1 588 * @param p points to a pbuf holding an ASN1 coded raw data
hendrikvincent 0:05ccbd4f84f1 589 * @param ofs points to the offset within the pbuf chain of the ASN1 coded raw data
hendrikvincent 0:05ccbd4f84f1 590 * @param len length of the coded raw data (zero is valid, e.g. empty string!)
hendrikvincent 0:05ccbd4f84f1 591 * @param raw_len length of the raw return value
hendrikvincent 0:05ccbd4f84f1 592 * @param raw return raw bytes
hendrikvincent 0:05ccbd4f84f1 593 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode
hendrikvincent 0:05ccbd4f84f1 594 */
hendrikvincent 0:05ccbd4f84f1 595 err_t
hendrikvincent 0:05ccbd4f84f1 596 snmp_asn1_dec_raw(struct pbuf *p, u16_t ofs, u16_t len, u16_t raw_len, u8_t *raw)
hendrikvincent 0:05ccbd4f84f1 597 {
hendrikvincent 0:05ccbd4f84f1 598 u16_t plen, base;
hendrikvincent 0:05ccbd4f84f1 599 u8_t *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 600
hendrikvincent 0:05ccbd4f84f1 601 if (len > 0)
hendrikvincent 0:05ccbd4f84f1 602 {
hendrikvincent 0:05ccbd4f84f1 603 plen = 0;
hendrikvincent 0:05ccbd4f84f1 604 while (p != NULL)
hendrikvincent 0:05ccbd4f84f1 605 {
hendrikvincent 0:05ccbd4f84f1 606 base = plen;
hendrikvincent 0:05ccbd4f84f1 607 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 608 if (ofs < plen)
hendrikvincent 0:05ccbd4f84f1 609 {
hendrikvincent 0:05ccbd4f84f1 610 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 611 msg_ptr += ofs - base;
hendrikvincent 0:05ccbd4f84f1 612 if (raw_len >= len)
hendrikvincent 0:05ccbd4f84f1 613 {
hendrikvincent 0:05ccbd4f84f1 614 while (len > 1)
hendrikvincent 0:05ccbd4f84f1 615 {
hendrikvincent 0:05ccbd4f84f1 616 /* copy len - 1 octets */
hendrikvincent 0:05ccbd4f84f1 617 len--;
hendrikvincent 0:05ccbd4f84f1 618 *raw = *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 619 raw++;
hendrikvincent 0:05ccbd4f84f1 620 ofs += 1;
hendrikvincent 0:05ccbd4f84f1 621 if (ofs >= plen)
hendrikvincent 0:05ccbd4f84f1 622 {
hendrikvincent 0:05ccbd4f84f1 623 /* next octet in next pbuf */
hendrikvincent 0:05ccbd4f84f1 624 p = p->next;
hendrikvincent 0:05ccbd4f84f1 625 if (p == NULL) { return ERR_ARG; }
hendrikvincent 0:05ccbd4f84f1 626 msg_ptr = (u8_t*)p->payload;
hendrikvincent 0:05ccbd4f84f1 627 plen += p->len;
hendrikvincent 0:05ccbd4f84f1 628 }
hendrikvincent 0:05ccbd4f84f1 629 else
hendrikvincent 0:05ccbd4f84f1 630 {
hendrikvincent 0:05ccbd4f84f1 631 /* next octet in same pbuf */
hendrikvincent 0:05ccbd4f84f1 632 msg_ptr++;
hendrikvincent 0:05ccbd4f84f1 633 }
hendrikvincent 0:05ccbd4f84f1 634 }
hendrikvincent 0:05ccbd4f84f1 635 /* copy last octet */
hendrikvincent 0:05ccbd4f84f1 636 *raw = *msg_ptr;
hendrikvincent 0:05ccbd4f84f1 637 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 638 }
hendrikvincent 0:05ccbd4f84f1 639 else
hendrikvincent 0:05ccbd4f84f1 640 {
hendrikvincent 0:05ccbd4f84f1 641 /* raw_len < len, not enough dst space */
hendrikvincent 0:05ccbd4f84f1 642 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 643 }
hendrikvincent 0:05ccbd4f84f1 644 }
hendrikvincent 0:05ccbd4f84f1 645 p = p->next;
hendrikvincent 0:05ccbd4f84f1 646 }
hendrikvincent 0:05ccbd4f84f1 647 /* p == NULL, ofs >= plen */
hendrikvincent 0:05ccbd4f84f1 648 return ERR_ARG;
hendrikvincent 0:05ccbd4f84f1 649 }
hendrikvincent 0:05ccbd4f84f1 650 else
hendrikvincent 0:05ccbd4f84f1 651 {
hendrikvincent 0:05ccbd4f84f1 652 /* len == 0, empty string */
hendrikvincent 0:05ccbd4f84f1 653 return ERR_OK;
hendrikvincent 0:05ccbd4f84f1 654 }
hendrikvincent 0:05ccbd4f84f1 655 }
hendrikvincent 0:05ccbd4f84f1 656
hendrikvincent 0:05ccbd4f84f1 657 #endif /* LWIP_SNMP */