Lorcan Smith
/
Enet_SPI
SNMP agent attached to SPI slave
lwip/core/snmp/asn1_dec.c@0:2a53a4c3238c, 2012-08-13 (annotated)
- Committer:
- lorcansmith
- Date:
- Mon Aug 13 15:07:40 2012 +0000
- Revision:
- 0:2a53a4c3238c
v1.1 release includes ioAlarm traps
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
lorcansmith | 0:2a53a4c3238c | 1 | /** |
lorcansmith | 0:2a53a4c3238c | 2 | * @file |
lorcansmith | 0:2a53a4c3238c | 3 | * Abstract Syntax Notation One (ISO 8824, 8825) decoding |
lorcansmith | 0:2a53a4c3238c | 4 | * |
lorcansmith | 0:2a53a4c3238c | 5 | * @todo not optimised (yet), favor correctness over speed, favor speed over size |
lorcansmith | 0:2a53a4c3238c | 6 | */ |
lorcansmith | 0:2a53a4c3238c | 7 | |
lorcansmith | 0:2a53a4c3238c | 8 | /* |
lorcansmith | 0:2a53a4c3238c | 9 | * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. |
lorcansmith | 0:2a53a4c3238c | 10 | * All rights reserved. |
lorcansmith | 0:2a53a4c3238c | 11 | * |
lorcansmith | 0:2a53a4c3238c | 12 | * Redistribution and use in source and binary forms, with or without modification, |
lorcansmith | 0:2a53a4c3238c | 13 | * are permitted provided that the following conditions are met: |
lorcansmith | 0:2a53a4c3238c | 14 | * |
lorcansmith | 0:2a53a4c3238c | 15 | * 1. Redistributions of source code must retain the above copyright notice, |
lorcansmith | 0:2a53a4c3238c | 16 | * this list of conditions and the following disclaimer. |
lorcansmith | 0:2a53a4c3238c | 17 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
lorcansmith | 0:2a53a4c3238c | 18 | * this list of conditions and the following disclaimer in the documentation |
lorcansmith | 0:2a53a4c3238c | 19 | * and/or other materials provided with the distribution. |
lorcansmith | 0:2a53a4c3238c | 20 | * 3. The name of the author may not be used to endorse or promote products |
lorcansmith | 0:2a53a4c3238c | 21 | * derived from this software without specific prior written permission. |
lorcansmith | 0:2a53a4c3238c | 22 | * |
lorcansmith | 0:2a53a4c3238c | 23 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
lorcansmith | 0:2a53a4c3238c | 24 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
lorcansmith | 0:2a53a4c3238c | 25 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
lorcansmith | 0:2a53a4c3238c | 26 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
lorcansmith | 0:2a53a4c3238c | 27 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
lorcansmith | 0:2a53a4c3238c | 28 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
lorcansmith | 0:2a53a4c3238c | 29 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
lorcansmith | 0:2a53a4c3238c | 30 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
lorcansmith | 0:2a53a4c3238c | 31 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
lorcansmith | 0:2a53a4c3238c | 32 | * OF SUCH DAMAGE. |
lorcansmith | 0:2a53a4c3238c | 33 | * |
lorcansmith | 0:2a53a4c3238c | 34 | * Author: Christiaan Simons <christiaan.simons@axon.tv> |
lorcansmith | 0:2a53a4c3238c | 35 | */ |
lorcansmith | 0:2a53a4c3238c | 36 | |
lorcansmith | 0:2a53a4c3238c | 37 | #include "lwip/opt.h" |
lorcansmith | 0:2a53a4c3238c | 38 | |
lorcansmith | 0:2a53a4c3238c | 39 | #if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */ |
lorcansmith | 0:2a53a4c3238c | 40 | |
lorcansmith | 0:2a53a4c3238c | 41 | #include "lwip/snmp_asn1.h" |
lorcansmith | 0:2a53a4c3238c | 42 | |
lorcansmith | 0:2a53a4c3238c | 43 | /** |
lorcansmith | 0:2a53a4c3238c | 44 | * Retrieves type field from incoming pbuf chain. |
lorcansmith | 0:2a53a4c3238c | 45 | * |
lorcansmith | 0:2a53a4c3238c | 46 | * @param p points to a pbuf holding an ASN1 coded type field |
lorcansmith | 0:2a53a4c3238c | 47 | * @param ofs points to the offset within the pbuf chain of the ASN1 coded type field |
lorcansmith | 0:2a53a4c3238c | 48 | * @param type return ASN1 type |
lorcansmith | 0:2a53a4c3238c | 49 | * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode |
lorcansmith | 0:2a53a4c3238c | 50 | */ |
lorcansmith | 0:2a53a4c3238c | 51 | err_t |
lorcansmith | 0:2a53a4c3238c | 52 | snmp_asn1_dec_type(struct pbuf *p, u16_t ofs, u8_t *type) |
lorcansmith | 0:2a53a4c3238c | 53 | { |
lorcansmith | 0:2a53a4c3238c | 54 | u16_t plen, base; |
lorcansmith | 0:2a53a4c3238c | 55 | u8_t *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 56 | |
lorcansmith | 0:2a53a4c3238c | 57 | plen = 0; |
lorcansmith | 0:2a53a4c3238c | 58 | while (p != NULL) |
lorcansmith | 0:2a53a4c3238c | 59 | { |
lorcansmith | 0:2a53a4c3238c | 60 | base = plen; |
lorcansmith | 0:2a53a4c3238c | 61 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 62 | if (ofs < plen) |
lorcansmith | 0:2a53a4c3238c | 63 | { |
lorcansmith | 0:2a53a4c3238c | 64 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 65 | msg_ptr += ofs - base; |
lorcansmith | 0:2a53a4c3238c | 66 | *type = *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 67 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 68 | } |
lorcansmith | 0:2a53a4c3238c | 69 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 70 | } |
lorcansmith | 0:2a53a4c3238c | 71 | /* p == NULL, ofs >= plen */ |
lorcansmith | 0:2a53a4c3238c | 72 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 73 | } |
lorcansmith | 0:2a53a4c3238c | 74 | |
lorcansmith | 0:2a53a4c3238c | 75 | /** |
lorcansmith | 0:2a53a4c3238c | 76 | * Decodes length field from incoming pbuf chain into host length. |
lorcansmith | 0:2a53a4c3238c | 77 | * |
lorcansmith | 0:2a53a4c3238c | 78 | * @param p points to a pbuf holding an ASN1 coded length |
lorcansmith | 0:2a53a4c3238c | 79 | * @param ofs points to the offset within the pbuf chain of the ASN1 coded length |
lorcansmith | 0:2a53a4c3238c | 80 | * @param octets_used returns number of octets used by the length code |
lorcansmith | 0:2a53a4c3238c | 81 | * @param length return host order length, upto 64k |
lorcansmith | 0:2a53a4c3238c | 82 | * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode |
lorcansmith | 0:2a53a4c3238c | 83 | */ |
lorcansmith | 0:2a53a4c3238c | 84 | err_t |
lorcansmith | 0:2a53a4c3238c | 85 | snmp_asn1_dec_length(struct pbuf *p, u16_t ofs, u8_t *octets_used, u16_t *length) |
lorcansmith | 0:2a53a4c3238c | 86 | { |
lorcansmith | 0:2a53a4c3238c | 87 | u16_t plen, base; |
lorcansmith | 0:2a53a4c3238c | 88 | u8_t *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 89 | |
lorcansmith | 0:2a53a4c3238c | 90 | plen = 0; |
lorcansmith | 0:2a53a4c3238c | 91 | while (p != NULL) |
lorcansmith | 0:2a53a4c3238c | 92 | { |
lorcansmith | 0:2a53a4c3238c | 93 | base = plen; |
lorcansmith | 0:2a53a4c3238c | 94 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 95 | if (ofs < plen) |
lorcansmith | 0:2a53a4c3238c | 96 | { |
lorcansmith | 0:2a53a4c3238c | 97 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 98 | msg_ptr += ofs - base; |
lorcansmith | 0:2a53a4c3238c | 99 | |
lorcansmith | 0:2a53a4c3238c | 100 | if (*msg_ptr < 0x80) |
lorcansmith | 0:2a53a4c3238c | 101 | { |
lorcansmith | 0:2a53a4c3238c | 102 | /* primitive definite length format */ |
lorcansmith | 0:2a53a4c3238c | 103 | *octets_used = 1; |
lorcansmith | 0:2a53a4c3238c | 104 | *length = *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 105 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 106 | } |
lorcansmith | 0:2a53a4c3238c | 107 | else if (*msg_ptr == 0x80) |
lorcansmith | 0:2a53a4c3238c | 108 | { |
lorcansmith | 0:2a53a4c3238c | 109 | /* constructed indefinite length format, termination with two zero octets */ |
lorcansmith | 0:2a53a4c3238c | 110 | u8_t zeros; |
lorcansmith | 0:2a53a4c3238c | 111 | u8_t i; |
lorcansmith | 0:2a53a4c3238c | 112 | |
lorcansmith | 0:2a53a4c3238c | 113 | *length = 0; |
lorcansmith | 0:2a53a4c3238c | 114 | zeros = 0; |
lorcansmith | 0:2a53a4c3238c | 115 | while (zeros != 2) |
lorcansmith | 0:2a53a4c3238c | 116 | { |
lorcansmith | 0:2a53a4c3238c | 117 | i = 2; |
lorcansmith | 0:2a53a4c3238c | 118 | while (i > 0) |
lorcansmith | 0:2a53a4c3238c | 119 | { |
lorcansmith | 0:2a53a4c3238c | 120 | i--; |
lorcansmith | 0:2a53a4c3238c | 121 | (*length) += 1; |
lorcansmith | 0:2a53a4c3238c | 122 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 123 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 124 | { |
lorcansmith | 0:2a53a4c3238c | 125 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 126 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 127 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 128 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 129 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 130 | } |
lorcansmith | 0:2a53a4c3238c | 131 | else |
lorcansmith | 0:2a53a4c3238c | 132 | { |
lorcansmith | 0:2a53a4c3238c | 133 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 134 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 135 | } |
lorcansmith | 0:2a53a4c3238c | 136 | if (*msg_ptr == 0) |
lorcansmith | 0:2a53a4c3238c | 137 | { |
lorcansmith | 0:2a53a4c3238c | 138 | zeros++; |
lorcansmith | 0:2a53a4c3238c | 139 | if (zeros == 2) |
lorcansmith | 0:2a53a4c3238c | 140 | { |
lorcansmith | 0:2a53a4c3238c | 141 | /* stop while (i > 0) */ |
lorcansmith | 0:2a53a4c3238c | 142 | i = 0; |
lorcansmith | 0:2a53a4c3238c | 143 | } |
lorcansmith | 0:2a53a4c3238c | 144 | } |
lorcansmith | 0:2a53a4c3238c | 145 | else |
lorcansmith | 0:2a53a4c3238c | 146 | { |
lorcansmith | 0:2a53a4c3238c | 147 | zeros = 0; |
lorcansmith | 0:2a53a4c3238c | 148 | } |
lorcansmith | 0:2a53a4c3238c | 149 | } |
lorcansmith | 0:2a53a4c3238c | 150 | } |
lorcansmith | 0:2a53a4c3238c | 151 | *octets_used = 1; |
lorcansmith | 0:2a53a4c3238c | 152 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 153 | } |
lorcansmith | 0:2a53a4c3238c | 154 | else if (*msg_ptr == 0x81) |
lorcansmith | 0:2a53a4c3238c | 155 | { |
lorcansmith | 0:2a53a4c3238c | 156 | /* constructed definite length format, one octet */ |
lorcansmith | 0:2a53a4c3238c | 157 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 158 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 159 | { |
lorcansmith | 0:2a53a4c3238c | 160 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 161 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 162 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 163 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 164 | } |
lorcansmith | 0:2a53a4c3238c | 165 | else |
lorcansmith | 0:2a53a4c3238c | 166 | { |
lorcansmith | 0:2a53a4c3238c | 167 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 168 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 169 | } |
lorcansmith | 0:2a53a4c3238c | 170 | *length = *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 171 | *octets_used = 2; |
lorcansmith | 0:2a53a4c3238c | 172 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 173 | } |
lorcansmith | 0:2a53a4c3238c | 174 | else if (*msg_ptr == 0x82) |
lorcansmith | 0:2a53a4c3238c | 175 | { |
lorcansmith | 0:2a53a4c3238c | 176 | u8_t i; |
lorcansmith | 0:2a53a4c3238c | 177 | |
lorcansmith | 0:2a53a4c3238c | 178 | /* constructed definite length format, two octets */ |
lorcansmith | 0:2a53a4c3238c | 179 | i = 2; |
lorcansmith | 0:2a53a4c3238c | 180 | while (i > 0) |
lorcansmith | 0:2a53a4c3238c | 181 | { |
lorcansmith | 0:2a53a4c3238c | 182 | i--; |
lorcansmith | 0:2a53a4c3238c | 183 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 184 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 185 | { |
lorcansmith | 0:2a53a4c3238c | 186 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 187 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 188 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 189 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 190 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 191 | } |
lorcansmith | 0:2a53a4c3238c | 192 | else |
lorcansmith | 0:2a53a4c3238c | 193 | { |
lorcansmith | 0:2a53a4c3238c | 194 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 195 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 196 | } |
lorcansmith | 0:2a53a4c3238c | 197 | if (i == 0) |
lorcansmith | 0:2a53a4c3238c | 198 | { |
lorcansmith | 0:2a53a4c3238c | 199 | /* least significant length octet */ |
lorcansmith | 0:2a53a4c3238c | 200 | *length |= *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 201 | } |
lorcansmith | 0:2a53a4c3238c | 202 | else |
lorcansmith | 0:2a53a4c3238c | 203 | { |
lorcansmith | 0:2a53a4c3238c | 204 | /* most significant length octet */ |
lorcansmith | 0:2a53a4c3238c | 205 | *length = (*msg_ptr) << 8; |
lorcansmith | 0:2a53a4c3238c | 206 | } |
lorcansmith | 0:2a53a4c3238c | 207 | } |
lorcansmith | 0:2a53a4c3238c | 208 | *octets_used = 3; |
lorcansmith | 0:2a53a4c3238c | 209 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 210 | } |
lorcansmith | 0:2a53a4c3238c | 211 | else |
lorcansmith | 0:2a53a4c3238c | 212 | { |
lorcansmith | 0:2a53a4c3238c | 213 | /* constructed definite length format 3..127 octets, this is too big (>64k) */ |
lorcansmith | 0:2a53a4c3238c | 214 | /** @todo: do we need to accept inefficient codings with many leading zero's? */ |
lorcansmith | 0:2a53a4c3238c | 215 | *octets_used = 1 + ((*msg_ptr) & 0x7f); |
lorcansmith | 0:2a53a4c3238c | 216 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 217 | } |
lorcansmith | 0:2a53a4c3238c | 218 | } |
lorcansmith | 0:2a53a4c3238c | 219 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 220 | } |
lorcansmith | 0:2a53a4c3238c | 221 | |
lorcansmith | 0:2a53a4c3238c | 222 | /* p == NULL, ofs >= plen */ |
lorcansmith | 0:2a53a4c3238c | 223 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 224 | } |
lorcansmith | 0:2a53a4c3238c | 225 | |
lorcansmith | 0:2a53a4c3238c | 226 | /** |
lorcansmith | 0:2a53a4c3238c | 227 | * Decodes positive integer (counter, gauge, timeticks) into u32_t. |
lorcansmith | 0:2a53a4c3238c | 228 | * |
lorcansmith | 0:2a53a4c3238c | 229 | * @param p points to a pbuf holding an ASN1 coded integer |
lorcansmith | 0:2a53a4c3238c | 230 | * @param ofs points to the offset within the pbuf chain of the ASN1 coded integer |
lorcansmith | 0:2a53a4c3238c | 231 | * @param len length of the coded integer field |
lorcansmith | 0:2a53a4c3238c | 232 | * @param value return host order integer |
lorcansmith | 0:2a53a4c3238c | 233 | * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode |
lorcansmith | 0:2a53a4c3238c | 234 | * |
lorcansmith | 0:2a53a4c3238c | 235 | * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded |
lorcansmith | 0:2a53a4c3238c | 236 | * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value |
lorcansmith | 0:2a53a4c3238c | 237 | * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!! |
lorcansmith | 0:2a53a4c3238c | 238 | */ |
lorcansmith | 0:2a53a4c3238c | 239 | err_t |
lorcansmith | 0:2a53a4c3238c | 240 | snmp_asn1_dec_u32t(struct pbuf *p, u16_t ofs, u16_t len, u32_t *value) |
lorcansmith | 0:2a53a4c3238c | 241 | { |
lorcansmith | 0:2a53a4c3238c | 242 | u16_t plen, base; |
lorcansmith | 0:2a53a4c3238c | 243 | u8_t *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 244 | |
lorcansmith | 0:2a53a4c3238c | 245 | plen = 0; |
lorcansmith | 0:2a53a4c3238c | 246 | while (p != NULL) |
lorcansmith | 0:2a53a4c3238c | 247 | { |
lorcansmith | 0:2a53a4c3238c | 248 | base = plen; |
lorcansmith | 0:2a53a4c3238c | 249 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 250 | if (ofs < plen) |
lorcansmith | 0:2a53a4c3238c | 251 | { |
lorcansmith | 0:2a53a4c3238c | 252 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 253 | msg_ptr += ofs - base; |
lorcansmith | 0:2a53a4c3238c | 254 | if ((len > 0) && (len < 6)) |
lorcansmith | 0:2a53a4c3238c | 255 | { |
lorcansmith | 0:2a53a4c3238c | 256 | /* start from zero */ |
lorcansmith | 0:2a53a4c3238c | 257 | *value = 0; |
lorcansmith | 0:2a53a4c3238c | 258 | if (*msg_ptr & 0x80) |
lorcansmith | 0:2a53a4c3238c | 259 | { |
lorcansmith | 0:2a53a4c3238c | 260 | /* negative, expecting zero sign bit! */ |
lorcansmith | 0:2a53a4c3238c | 261 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 262 | } |
lorcansmith | 0:2a53a4c3238c | 263 | else |
lorcansmith | 0:2a53a4c3238c | 264 | { |
lorcansmith | 0:2a53a4c3238c | 265 | /* positive */ |
lorcansmith | 0:2a53a4c3238c | 266 | if ((len > 1) && (*msg_ptr == 0)) |
lorcansmith | 0:2a53a4c3238c | 267 | { |
lorcansmith | 0:2a53a4c3238c | 268 | /* skip leading "sign byte" octet 0x00 */ |
lorcansmith | 0:2a53a4c3238c | 269 | len--; |
lorcansmith | 0:2a53a4c3238c | 270 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 271 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 272 | { |
lorcansmith | 0:2a53a4c3238c | 273 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 274 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 275 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 276 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 277 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 278 | } |
lorcansmith | 0:2a53a4c3238c | 279 | else |
lorcansmith | 0:2a53a4c3238c | 280 | { |
lorcansmith | 0:2a53a4c3238c | 281 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 282 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 283 | } |
lorcansmith | 0:2a53a4c3238c | 284 | } |
lorcansmith | 0:2a53a4c3238c | 285 | } |
lorcansmith | 0:2a53a4c3238c | 286 | /* OR octets with value */ |
lorcansmith | 0:2a53a4c3238c | 287 | while (len > 1) |
lorcansmith | 0:2a53a4c3238c | 288 | { |
lorcansmith | 0:2a53a4c3238c | 289 | len--; |
lorcansmith | 0:2a53a4c3238c | 290 | *value |= *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 291 | *value <<= 8; |
lorcansmith | 0:2a53a4c3238c | 292 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 293 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 294 | { |
lorcansmith | 0:2a53a4c3238c | 295 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 296 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 297 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 298 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 299 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 300 | } |
lorcansmith | 0:2a53a4c3238c | 301 | else |
lorcansmith | 0:2a53a4c3238c | 302 | { |
lorcansmith | 0:2a53a4c3238c | 303 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 304 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 305 | } |
lorcansmith | 0:2a53a4c3238c | 306 | } |
lorcansmith | 0:2a53a4c3238c | 307 | *value |= *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 308 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 309 | } |
lorcansmith | 0:2a53a4c3238c | 310 | else |
lorcansmith | 0:2a53a4c3238c | 311 | { |
lorcansmith | 0:2a53a4c3238c | 312 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 313 | } |
lorcansmith | 0:2a53a4c3238c | 314 | } |
lorcansmith | 0:2a53a4c3238c | 315 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 316 | } |
lorcansmith | 0:2a53a4c3238c | 317 | /* p == NULL, ofs >= plen */ |
lorcansmith | 0:2a53a4c3238c | 318 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 319 | } |
lorcansmith | 0:2a53a4c3238c | 320 | |
lorcansmith | 0:2a53a4c3238c | 321 | /** |
lorcansmith | 0:2a53a4c3238c | 322 | * Decodes integer into s32_t. |
lorcansmith | 0:2a53a4c3238c | 323 | * |
lorcansmith | 0:2a53a4c3238c | 324 | * @param p points to a pbuf holding an ASN1 coded integer |
lorcansmith | 0:2a53a4c3238c | 325 | * @param ofs points to the offset within the pbuf chain of the ASN1 coded integer |
lorcansmith | 0:2a53a4c3238c | 326 | * @param len length of the coded integer field |
lorcansmith | 0:2a53a4c3238c | 327 | * @param value return host order integer |
lorcansmith | 0:2a53a4c3238c | 328 | * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode |
lorcansmith | 0:2a53a4c3238c | 329 | * |
lorcansmith | 0:2a53a4c3238c | 330 | * @note ASN coded integers are _always_ signed! |
lorcansmith | 0:2a53a4c3238c | 331 | */ |
lorcansmith | 0:2a53a4c3238c | 332 | err_t |
lorcansmith | 0:2a53a4c3238c | 333 | snmp_asn1_dec_s32t(struct pbuf *p, u16_t ofs, u16_t len, s32_t *value) |
lorcansmith | 0:2a53a4c3238c | 334 | { |
lorcansmith | 0:2a53a4c3238c | 335 | u16_t plen, base; |
lorcansmith | 0:2a53a4c3238c | 336 | u8_t *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 337 | #if BYTE_ORDER == LITTLE_ENDIAN |
lorcansmith | 0:2a53a4c3238c | 338 | u8_t *lsb_ptr = (u8_t*)value; |
lorcansmith | 0:2a53a4c3238c | 339 | #endif |
lorcansmith | 0:2a53a4c3238c | 340 | #if BYTE_ORDER == BIG_ENDIAN |
lorcansmith | 0:2a53a4c3238c | 341 | u8_t *lsb_ptr = (u8_t*)value + sizeof(s32_t) - 1; |
lorcansmith | 0:2a53a4c3238c | 342 | #endif |
lorcansmith | 0:2a53a4c3238c | 343 | u8_t sign; |
lorcansmith | 0:2a53a4c3238c | 344 | |
lorcansmith | 0:2a53a4c3238c | 345 | plen = 0; |
lorcansmith | 0:2a53a4c3238c | 346 | while (p != NULL) |
lorcansmith | 0:2a53a4c3238c | 347 | { |
lorcansmith | 0:2a53a4c3238c | 348 | base = plen; |
lorcansmith | 0:2a53a4c3238c | 349 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 350 | if (ofs < plen) |
lorcansmith | 0:2a53a4c3238c | 351 | { |
lorcansmith | 0:2a53a4c3238c | 352 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 353 | msg_ptr += ofs - base; |
lorcansmith | 0:2a53a4c3238c | 354 | if ((len > 0) && (len < 5)) |
lorcansmith | 0:2a53a4c3238c | 355 | { |
lorcansmith | 0:2a53a4c3238c | 356 | if (*msg_ptr & 0x80) |
lorcansmith | 0:2a53a4c3238c | 357 | { |
lorcansmith | 0:2a53a4c3238c | 358 | /* negative, start from -1 */ |
lorcansmith | 0:2a53a4c3238c | 359 | *value = -1; |
lorcansmith | 0:2a53a4c3238c | 360 | sign = 1; |
lorcansmith | 0:2a53a4c3238c | 361 | } |
lorcansmith | 0:2a53a4c3238c | 362 | else |
lorcansmith | 0:2a53a4c3238c | 363 | { |
lorcansmith | 0:2a53a4c3238c | 364 | /* positive, start from 0 */ |
lorcansmith | 0:2a53a4c3238c | 365 | *value = 0; |
lorcansmith | 0:2a53a4c3238c | 366 | sign = 0; |
lorcansmith | 0:2a53a4c3238c | 367 | } |
lorcansmith | 0:2a53a4c3238c | 368 | /* OR/AND octets with value */ |
lorcansmith | 0:2a53a4c3238c | 369 | while (len > 1) |
lorcansmith | 0:2a53a4c3238c | 370 | { |
lorcansmith | 0:2a53a4c3238c | 371 | len--; |
lorcansmith | 0:2a53a4c3238c | 372 | if (sign) |
lorcansmith | 0:2a53a4c3238c | 373 | { |
lorcansmith | 0:2a53a4c3238c | 374 | *lsb_ptr &= *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 375 | *value <<= 8; |
lorcansmith | 0:2a53a4c3238c | 376 | *lsb_ptr |= 255; |
lorcansmith | 0:2a53a4c3238c | 377 | } |
lorcansmith | 0:2a53a4c3238c | 378 | else |
lorcansmith | 0:2a53a4c3238c | 379 | { |
lorcansmith | 0:2a53a4c3238c | 380 | *lsb_ptr |= *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 381 | *value <<= 8; |
lorcansmith | 0:2a53a4c3238c | 382 | } |
lorcansmith | 0:2a53a4c3238c | 383 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 384 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 385 | { |
lorcansmith | 0:2a53a4c3238c | 386 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 387 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 388 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 389 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 390 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 391 | } |
lorcansmith | 0:2a53a4c3238c | 392 | else |
lorcansmith | 0:2a53a4c3238c | 393 | { |
lorcansmith | 0:2a53a4c3238c | 394 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 395 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 396 | } |
lorcansmith | 0:2a53a4c3238c | 397 | } |
lorcansmith | 0:2a53a4c3238c | 398 | if (sign) |
lorcansmith | 0:2a53a4c3238c | 399 | { |
lorcansmith | 0:2a53a4c3238c | 400 | *lsb_ptr &= *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 401 | } |
lorcansmith | 0:2a53a4c3238c | 402 | else |
lorcansmith | 0:2a53a4c3238c | 403 | { |
lorcansmith | 0:2a53a4c3238c | 404 | *lsb_ptr |= *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 405 | } |
lorcansmith | 0:2a53a4c3238c | 406 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 407 | } |
lorcansmith | 0:2a53a4c3238c | 408 | else |
lorcansmith | 0:2a53a4c3238c | 409 | { |
lorcansmith | 0:2a53a4c3238c | 410 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 411 | } |
lorcansmith | 0:2a53a4c3238c | 412 | } |
lorcansmith | 0:2a53a4c3238c | 413 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 414 | } |
lorcansmith | 0:2a53a4c3238c | 415 | /* p == NULL, ofs >= plen */ |
lorcansmith | 0:2a53a4c3238c | 416 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 417 | } |
lorcansmith | 0:2a53a4c3238c | 418 | |
lorcansmith | 0:2a53a4c3238c | 419 | /** |
lorcansmith | 0:2a53a4c3238c | 420 | * Decodes object identifier from incoming message into array of s32_t. |
lorcansmith | 0:2a53a4c3238c | 421 | * |
lorcansmith | 0:2a53a4c3238c | 422 | * @param p points to a pbuf holding an ASN1 coded object identifier |
lorcansmith | 0:2a53a4c3238c | 423 | * @param ofs points to the offset within the pbuf chain of the ASN1 coded object identifier |
lorcansmith | 0:2a53a4c3238c | 424 | * @param len length of the coded object identifier |
lorcansmith | 0:2a53a4c3238c | 425 | * @param oid return object identifier struct |
lorcansmith | 0:2a53a4c3238c | 426 | * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode |
lorcansmith | 0:2a53a4c3238c | 427 | */ |
lorcansmith | 0:2a53a4c3238c | 428 | err_t |
lorcansmith | 0:2a53a4c3238c | 429 | snmp_asn1_dec_oid(struct pbuf *p, u16_t ofs, u16_t len, struct snmp_obj_id *oid) |
lorcansmith | 0:2a53a4c3238c | 430 | { |
lorcansmith | 0:2a53a4c3238c | 431 | u16_t plen, base; |
lorcansmith | 0:2a53a4c3238c | 432 | u8_t *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 433 | s32_t *oid_ptr; |
lorcansmith | 0:2a53a4c3238c | 434 | |
lorcansmith | 0:2a53a4c3238c | 435 | plen = 0; |
lorcansmith | 0:2a53a4c3238c | 436 | while (p != NULL) |
lorcansmith | 0:2a53a4c3238c | 437 | { |
lorcansmith | 0:2a53a4c3238c | 438 | base = plen; |
lorcansmith | 0:2a53a4c3238c | 439 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 440 | if (ofs < plen) |
lorcansmith | 0:2a53a4c3238c | 441 | { |
lorcansmith | 0:2a53a4c3238c | 442 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 443 | msg_ptr += ofs - base; |
lorcansmith | 0:2a53a4c3238c | 444 | |
lorcansmith | 0:2a53a4c3238c | 445 | oid->len = 0; |
lorcansmith | 0:2a53a4c3238c | 446 | oid_ptr = &oid->id[0]; |
lorcansmith | 0:2a53a4c3238c | 447 | if (len > 0) |
lorcansmith | 0:2a53a4c3238c | 448 | { |
lorcansmith | 0:2a53a4c3238c | 449 | /* first compressed octet */ |
lorcansmith | 0:2a53a4c3238c | 450 | if (*msg_ptr == 0x2B) |
lorcansmith | 0:2a53a4c3238c | 451 | { |
lorcansmith | 0:2a53a4c3238c | 452 | /* (most) common case 1.3 (iso.org) */ |
lorcansmith | 0:2a53a4c3238c | 453 | *oid_ptr = 1; |
lorcansmith | 0:2a53a4c3238c | 454 | oid_ptr++; |
lorcansmith | 0:2a53a4c3238c | 455 | *oid_ptr = 3; |
lorcansmith | 0:2a53a4c3238c | 456 | oid_ptr++; |
lorcansmith | 0:2a53a4c3238c | 457 | } |
lorcansmith | 0:2a53a4c3238c | 458 | else if (*msg_ptr < 40) |
lorcansmith | 0:2a53a4c3238c | 459 | { |
lorcansmith | 0:2a53a4c3238c | 460 | *oid_ptr = 0; |
lorcansmith | 0:2a53a4c3238c | 461 | oid_ptr++; |
lorcansmith | 0:2a53a4c3238c | 462 | *oid_ptr = *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 463 | oid_ptr++; |
lorcansmith | 0:2a53a4c3238c | 464 | } |
lorcansmith | 0:2a53a4c3238c | 465 | else if (*msg_ptr < 80) |
lorcansmith | 0:2a53a4c3238c | 466 | { |
lorcansmith | 0:2a53a4c3238c | 467 | *oid_ptr = 1; |
lorcansmith | 0:2a53a4c3238c | 468 | oid_ptr++; |
lorcansmith | 0:2a53a4c3238c | 469 | *oid_ptr = (*msg_ptr) - 40; |
lorcansmith | 0:2a53a4c3238c | 470 | oid_ptr++; |
lorcansmith | 0:2a53a4c3238c | 471 | } |
lorcansmith | 0:2a53a4c3238c | 472 | else |
lorcansmith | 0:2a53a4c3238c | 473 | { |
lorcansmith | 0:2a53a4c3238c | 474 | *oid_ptr = 2; |
lorcansmith | 0:2a53a4c3238c | 475 | oid_ptr++; |
lorcansmith | 0:2a53a4c3238c | 476 | *oid_ptr = (*msg_ptr) - 80; |
lorcansmith | 0:2a53a4c3238c | 477 | oid_ptr++; |
lorcansmith | 0:2a53a4c3238c | 478 | } |
lorcansmith | 0:2a53a4c3238c | 479 | oid->len = 2; |
lorcansmith | 0:2a53a4c3238c | 480 | } |
lorcansmith | 0:2a53a4c3238c | 481 | else |
lorcansmith | 0:2a53a4c3238c | 482 | { |
lorcansmith | 0:2a53a4c3238c | 483 | /* accepting zero length identifiers e.g. for |
lorcansmith | 0:2a53a4c3238c | 484 | getnext operation. uncommon but valid */ |
lorcansmith | 0:2a53a4c3238c | 485 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 486 | } |
lorcansmith | 0:2a53a4c3238c | 487 | len--; |
lorcansmith | 0:2a53a4c3238c | 488 | if (len > 0) |
lorcansmith | 0:2a53a4c3238c | 489 | { |
lorcansmith | 0:2a53a4c3238c | 490 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 491 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 492 | { |
lorcansmith | 0:2a53a4c3238c | 493 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 494 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 495 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 496 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 497 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 498 | } |
lorcansmith | 0:2a53a4c3238c | 499 | else |
lorcansmith | 0:2a53a4c3238c | 500 | { |
lorcansmith | 0:2a53a4c3238c | 501 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 502 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 503 | } |
lorcansmith | 0:2a53a4c3238c | 504 | } |
lorcansmith | 0:2a53a4c3238c | 505 | while ((len > 0) && (oid->len < LWIP_SNMP_OBJ_ID_LEN)) |
lorcansmith | 0:2a53a4c3238c | 506 | { |
lorcansmith | 0:2a53a4c3238c | 507 | /* sub-identifier uses multiple octets */ |
lorcansmith | 0:2a53a4c3238c | 508 | if (*msg_ptr & 0x80) |
lorcansmith | 0:2a53a4c3238c | 509 | { |
lorcansmith | 0:2a53a4c3238c | 510 | s32_t sub_id = 0; |
lorcansmith | 0:2a53a4c3238c | 511 | |
lorcansmith | 0:2a53a4c3238c | 512 | while ((*msg_ptr & 0x80) && (len > 1)) |
lorcansmith | 0:2a53a4c3238c | 513 | { |
lorcansmith | 0:2a53a4c3238c | 514 | len--; |
lorcansmith | 0:2a53a4c3238c | 515 | sub_id = (sub_id << 7) + (*msg_ptr & ~0x80); |
lorcansmith | 0:2a53a4c3238c | 516 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 517 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 518 | { |
lorcansmith | 0:2a53a4c3238c | 519 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 520 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 521 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 522 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 523 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 524 | } |
lorcansmith | 0:2a53a4c3238c | 525 | else |
lorcansmith | 0:2a53a4c3238c | 526 | { |
lorcansmith | 0:2a53a4c3238c | 527 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 528 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 529 | } |
lorcansmith | 0:2a53a4c3238c | 530 | } |
lorcansmith | 0:2a53a4c3238c | 531 | if (!(*msg_ptr & 0x80) && (len > 0)) |
lorcansmith | 0:2a53a4c3238c | 532 | { |
lorcansmith | 0:2a53a4c3238c | 533 | /* last octet sub-identifier */ |
lorcansmith | 0:2a53a4c3238c | 534 | len--; |
lorcansmith | 0:2a53a4c3238c | 535 | sub_id = (sub_id << 7) + *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 536 | *oid_ptr = sub_id; |
lorcansmith | 0:2a53a4c3238c | 537 | } |
lorcansmith | 0:2a53a4c3238c | 538 | } |
lorcansmith | 0:2a53a4c3238c | 539 | else |
lorcansmith | 0:2a53a4c3238c | 540 | { |
lorcansmith | 0:2a53a4c3238c | 541 | /* !(*msg_ptr & 0x80) sub-identifier uses single octet */ |
lorcansmith | 0:2a53a4c3238c | 542 | len--; |
lorcansmith | 0:2a53a4c3238c | 543 | *oid_ptr = *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 544 | // LWIP_DEBUGF(SNMP_MSG_DEBUG, ("\r\nsnmp_asn1_dec_oid . %d length left %d\r\n", *oid_ptr, len)); |
lorcansmith | 0:2a53a4c3238c | 545 | } |
lorcansmith | 0:2a53a4c3238c | 546 | if (len > 0) |
lorcansmith | 0:2a53a4c3238c | 547 | { |
lorcansmith | 0:2a53a4c3238c | 548 | /* remaining oid bytes available ... */ |
lorcansmith | 0:2a53a4c3238c | 549 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 550 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 551 | { |
lorcansmith | 0:2a53a4c3238c | 552 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 553 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 554 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 555 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 556 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 557 | } |
lorcansmith | 0:2a53a4c3238c | 558 | else |
lorcansmith | 0:2a53a4c3238c | 559 | { |
lorcansmith | 0:2a53a4c3238c | 560 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 561 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 562 | } |
lorcansmith | 0:2a53a4c3238c | 563 | } |
lorcansmith | 0:2a53a4c3238c | 564 | oid_ptr++; |
lorcansmith | 0:2a53a4c3238c | 565 | oid->len++; |
lorcansmith | 0:2a53a4c3238c | 566 | } |
lorcansmith | 0:2a53a4c3238c | 567 | if (len == 0) |
lorcansmith | 0:2a53a4c3238c | 568 | { |
lorcansmith | 0:2a53a4c3238c | 569 | /* len == 0, end of oid */ |
lorcansmith | 0:2a53a4c3238c | 570 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 571 | } |
lorcansmith | 0:2a53a4c3238c | 572 | else |
lorcansmith | 0:2a53a4c3238c | 573 | { |
lorcansmith | 0:2a53a4c3238c | 574 | /* len > 0, oid->len == LWIP_SNMP_OBJ_ID_LEN or malformed encoding */ |
lorcansmith | 0:2a53a4c3238c | 575 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("\r\nsnmp_asn1_dec_oid end ERR\r\n")); |
lorcansmith | 0:2a53a4c3238c | 576 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 577 | } |
lorcansmith | 0:2a53a4c3238c | 578 | |
lorcansmith | 0:2a53a4c3238c | 579 | } |
lorcansmith | 0:2a53a4c3238c | 580 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 581 | } |
lorcansmith | 0:2a53a4c3238c | 582 | /* p == NULL, ofs >= plen */ |
lorcansmith | 0:2a53a4c3238c | 583 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 584 | } |
lorcansmith | 0:2a53a4c3238c | 585 | |
lorcansmith | 0:2a53a4c3238c | 586 | /** |
lorcansmith | 0:2a53a4c3238c | 587 | * Decodes (copies) raw data (ip-addresses, octet strings, opaque encoding) |
lorcansmith | 0:2a53a4c3238c | 588 | * from incoming message into array. |
lorcansmith | 0:2a53a4c3238c | 589 | * |
lorcansmith | 0:2a53a4c3238c | 590 | * @param p points to a pbuf holding an ASN1 coded raw data |
lorcansmith | 0:2a53a4c3238c | 591 | * @param ofs points to the offset within the pbuf chain of the ASN1 coded raw data |
lorcansmith | 0:2a53a4c3238c | 592 | * @param len length of the coded raw data (zero is valid, e.g. empty string!) |
lorcansmith | 0:2a53a4c3238c | 593 | * @param raw_len length of the raw return value |
lorcansmith | 0:2a53a4c3238c | 594 | * @param raw return raw bytes |
lorcansmith | 0:2a53a4c3238c | 595 | * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) decode |
lorcansmith | 0:2a53a4c3238c | 596 | */ |
lorcansmith | 0:2a53a4c3238c | 597 | err_t |
lorcansmith | 0:2a53a4c3238c | 598 | snmp_asn1_dec_raw(struct pbuf *p, u16_t ofs, u16_t len, u16_t raw_len, u8_t *raw) |
lorcansmith | 0:2a53a4c3238c | 599 | { |
lorcansmith | 0:2a53a4c3238c | 600 | u16_t plen, base; |
lorcansmith | 0:2a53a4c3238c | 601 | u8_t *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 602 | |
lorcansmith | 0:2a53a4c3238c | 603 | if (len > 0) |
lorcansmith | 0:2a53a4c3238c | 604 | { |
lorcansmith | 0:2a53a4c3238c | 605 | plen = 0; |
lorcansmith | 0:2a53a4c3238c | 606 | while (p != NULL) |
lorcansmith | 0:2a53a4c3238c | 607 | { |
lorcansmith | 0:2a53a4c3238c | 608 | base = plen; |
lorcansmith | 0:2a53a4c3238c | 609 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 610 | if (ofs < plen) |
lorcansmith | 0:2a53a4c3238c | 611 | { |
lorcansmith | 0:2a53a4c3238c | 612 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 613 | msg_ptr += ofs - base; |
lorcansmith | 0:2a53a4c3238c | 614 | if (raw_len >= len) |
lorcansmith | 0:2a53a4c3238c | 615 | { |
lorcansmith | 0:2a53a4c3238c | 616 | while (len > 1) |
lorcansmith | 0:2a53a4c3238c | 617 | { |
lorcansmith | 0:2a53a4c3238c | 618 | /* copy len - 1 octets */ |
lorcansmith | 0:2a53a4c3238c | 619 | len--; |
lorcansmith | 0:2a53a4c3238c | 620 | *raw = *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 621 | raw++; |
lorcansmith | 0:2a53a4c3238c | 622 | ofs += 1; |
lorcansmith | 0:2a53a4c3238c | 623 | if (ofs >= plen) |
lorcansmith | 0:2a53a4c3238c | 624 | { |
lorcansmith | 0:2a53a4c3238c | 625 | /* next octet in next pbuf */ |
lorcansmith | 0:2a53a4c3238c | 626 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 627 | if (p == NULL) { return ERR_ARG; } |
lorcansmith | 0:2a53a4c3238c | 628 | msg_ptr = (u8_t*)p->payload; |
lorcansmith | 0:2a53a4c3238c | 629 | plen += p->len; |
lorcansmith | 0:2a53a4c3238c | 630 | } |
lorcansmith | 0:2a53a4c3238c | 631 | else |
lorcansmith | 0:2a53a4c3238c | 632 | { |
lorcansmith | 0:2a53a4c3238c | 633 | /* next octet in same pbuf */ |
lorcansmith | 0:2a53a4c3238c | 634 | msg_ptr++; |
lorcansmith | 0:2a53a4c3238c | 635 | } |
lorcansmith | 0:2a53a4c3238c | 636 | } |
lorcansmith | 0:2a53a4c3238c | 637 | /* copy last octet */ |
lorcansmith | 0:2a53a4c3238c | 638 | *raw = *msg_ptr; |
lorcansmith | 0:2a53a4c3238c | 639 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 640 | } |
lorcansmith | 0:2a53a4c3238c | 641 | else |
lorcansmith | 0:2a53a4c3238c | 642 | { |
lorcansmith | 0:2a53a4c3238c | 643 | /* raw_len < len, not enough dst space */ |
lorcansmith | 0:2a53a4c3238c | 644 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 645 | } |
lorcansmith | 0:2a53a4c3238c | 646 | } |
lorcansmith | 0:2a53a4c3238c | 647 | p = p->next; |
lorcansmith | 0:2a53a4c3238c | 648 | } |
lorcansmith | 0:2a53a4c3238c | 649 | /* p == NULL, ofs >= plen */ |
lorcansmith | 0:2a53a4c3238c | 650 | return ERR_ARG; |
lorcansmith | 0:2a53a4c3238c | 651 | } |
lorcansmith | 0:2a53a4c3238c | 652 | else |
lorcansmith | 0:2a53a4c3238c | 653 | { |
lorcansmith | 0:2a53a4c3238c | 654 | /* len == 0, empty string */ |
lorcansmith | 0:2a53a4c3238c | 655 | return ERR_OK; |
lorcansmith | 0:2a53a4c3238c | 656 | } |
lorcansmith | 0:2a53a4c3238c | 657 | } |
lorcansmith | 0:2a53a4c3238c | 658 | |
lorcansmith | 0:2a53a4c3238c | 659 | #endif /* LWIP_SNMP */ |