+++ /dev/null
-/**
- * @file
- * Abstract Syntax Notation One (ISO 8824, 8825) encoding
- *
- * @todo not optimised (yet), favor correctness over speed, favor speed over size
- */
-
-/*
- * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modification,
- * are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
- * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
- * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
- * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
- * OF SUCH DAMAGE.
- *
- * Author: Christiaan Simons <christiaan.simons@axon.tv>
- */
-
-#include "lwip/opt.h"
-
-#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
-
-#include "lwip/snmp_asn1.h"
-
-/**
- * Returns octet count for length.
- *
- * @param length
- * @param octets_needed points to the return value
- */
-void
-snmp_asn1_enc_length_cnt(u16_t length, u8_t *octets_needed)
-{
- if (length < 0x80U)
- {
- *octets_needed = 1;
- }
- else if (length < 0x100U)
- {
- *octets_needed = 2;
- }
- else
- {
- *octets_needed = 3;
- }
-}
-
-/**
- * Returns octet count for an u32_t.
- *
- * @param value
- * @param octets_needed points to the return value
- *
- * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded
- * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value
- * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!!
- */
-void
-snmp_asn1_enc_u32t_cnt(u32_t value, u16_t *octets_needed)
-{
- if (value < 0x80UL)
- {
- *octets_needed = 1;
- }
- else if (value < 0x8000UL)
- {
- *octets_needed = 2;
- }
- else if (value < 0x800000UL)
- {
- *octets_needed = 3;
- }
- else if (value < 0x80000000UL)
- {
- *octets_needed = 4;
- }
- else
- {
- *octets_needed = 5;
- }
-}
-
-/**
- * Returns octet count for an s32_t.
- *
- * @param value
- * @param octets_needed points to the return value
- *
- * @note ASN coded integers are _always_ signed.
- */
-void
-snmp_asn1_enc_s32t_cnt(s32_t value, u16_t *octets_needed)
-{
- if (value < 0)
- {
- value = ~value;
- }
- if (value < 0x80L)
- {
- *octets_needed = 1;
- }
- else if (value < 0x8000L)
- {
- *octets_needed = 2;
- }
- else if (value < 0x800000L)
- {
- *octets_needed = 3;
- }
- else
- {
- *octets_needed = 4;
- }
-}
-
-/**
- * Returns octet count for an object identifier.
- *
- * @param ident_len object identifier array length
- * @param ident points to object identifier array
- * @param octets_needed points to the return value
- */
-void
-snmp_asn1_enc_oid_cnt(u8_t ident_len, s32_t *ident, u16_t *octets_needed)
-{
- s32_t sub_id;
- u8_t cnt;
-
- cnt = 0;
- if (ident_len > 1)
- {
- /* compressed prefix in one octet */
- cnt++;
- ident_len -= 2;
- ident += 2;
- }
- while(ident_len > 0)
- {
- ident_len--;
- sub_id = *ident;
-
- sub_id >>= 7;
- cnt++;
- while(sub_id > 0)
- {
- sub_id >>= 7;
- cnt++;
- }
- ident++;
- }
- *octets_needed = cnt;
-}
-
-/**
- * Encodes ASN type field into a pbuf chained ASN1 msg.
- *
- * @param p points to output pbuf to encode value into
- * @param ofs points to the offset within the pbuf chain
- * @param type input ASN1 type
- * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
- */
-err_t
-snmp_asn1_enc_type(struct pbuf *p, u16_t ofs, u8_t type)
-{
- u16_t plen, base;
- u8_t *msg_ptr;
-
- plen = 0;
- while (p != NULL)
- {
- base = plen;
- plen += p->len;
- if (ofs < plen)
- {
- msg_ptr = (u8_t*)p->payload;
- msg_ptr += ofs - base;
- *msg_ptr = type;
- return ERR_OK;
- }
- p = p->next;
- }
- /* p == NULL, ofs >= plen */
- return ERR_ARG;
-}
-
-/**
- * Encodes host order length field into a pbuf chained ASN1 msg.
- *
- * @param p points to output pbuf to encode length into
- * @param ofs points to the offset within the pbuf chain
- * @param length is the host order length to be encoded
- * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
- */
-err_t
-snmp_asn1_enc_length(struct pbuf *p, u16_t ofs, u16_t length)
-{
- u16_t plen, base;
- u8_t *msg_ptr;
-
- plen = 0;
- while (p != NULL)
- {
- base = plen;
- plen += p->len;
- if (ofs < plen)
- {
- msg_ptr = (u8_t*)p->payload;
- msg_ptr += ofs - base;
-
- if (length < 0x80)
- {
- *msg_ptr = (u8_t)length;
- return ERR_OK;
- }
- else if (length < 0x100)
- {
- *msg_ptr = 0x81;
- ofs += 1;
- if (ofs >= plen)
- {
- /* next octet in next pbuf */
- p = p->next;
- if (p == NULL) { return ERR_ARG; }
- msg_ptr = (u8_t*)p->payload;
- }
- else
- {
- /* next octet in same pbuf */
- msg_ptr++;
- }
- *msg_ptr = (u8_t)length;
- return ERR_OK;
- }
- else
- {
- u8_t i;
-
- /* length >= 0x100 && length <= 0xFFFF */
- *msg_ptr = 0x82;
- i = 2;
- while (i > 0)
- {
- i--;
- ofs += 1;
- if (ofs >= plen)
- {
- /* next octet in next pbuf */
- p = p->next;
- if (p == NULL) { return ERR_ARG; }
- msg_ptr = (u8_t*)p->payload;
- plen += p->len;
- }
- else
- {
- /* next octet in same pbuf */
- msg_ptr++;
- }
- if (i == 0)
- {
- /* least significant length octet */
- *msg_ptr = (u8_t)length;
- }
- else
- {
- /* most significant length octet */
- *msg_ptr = (u8_t)(length >> 8);
- }
- }
- return ERR_OK;
- }
- }
- p = p->next;
- }
- /* p == NULL, ofs >= plen */
- return ERR_ARG;
-}
-
-/**
- * Encodes u32_t (counter, gauge, timeticks) into a pbuf chained ASN1 msg.
- *
- * @param p points to output pbuf to encode value into
- * @param ofs points to the offset within the pbuf chain
- * @param octets_needed encoding length (from snmp_asn1_enc_u32t_cnt())
- * @param value is the host order u32_t value to be encoded
- * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
- *
- * @see snmp_asn1_enc_u32t_cnt()
- */
-err_t
-snmp_asn1_enc_u32t(struct pbuf *p, u16_t ofs, u16_t octets_needed, u32_t value)
-{
- u16_t plen, base;
- u8_t *msg_ptr;
-
- plen = 0;
- while (p != NULL)
- {
- base = plen;
- plen += p->len;
- if (ofs < plen)
- {
- msg_ptr = (u8_t*)p->payload;
- msg_ptr += ofs - base;
-
- if (octets_needed == 5)
- {
- /* not enough bits in 'value' add leading 0x00 */
- octets_needed--;
- *msg_ptr = 0x00;
- ofs += 1;
- if (ofs >= plen)
- {
- /* next octet in next pbuf */
- p = p->next;
- if (p == NULL) { return ERR_ARG; }
- msg_ptr = (u8_t*)p->payload;
- plen += p->len;
- }
- else
- {
- /* next octet in same pbuf */
- msg_ptr++;
- }
- }
- while (octets_needed > 1)
- {
- octets_needed--;
- *msg_ptr = (u8_t)(value >> (octets_needed << 3));
- ofs += 1;
- if (ofs >= plen)
- {
- /* next octet in next pbuf */
- p = p->next;
- if (p == NULL) { return ERR_ARG; }
- msg_ptr = (u8_t*)p->payload;
- plen += p->len;
- }
- else
- {
- /* next octet in same pbuf */
- msg_ptr++;
- }
- }
- /* (only) one least significant octet */
- *msg_ptr = (u8_t)value;
- return ERR_OK;
- }
- p = p->next;
- }
- /* p == NULL, ofs >= plen */
- return ERR_ARG;
-}
-
-/**
- * Encodes s32_t integer into a pbuf chained ASN1 msg.
- *
- * @param p points to output pbuf to encode value into
- * @param ofs points to the offset within the pbuf chain
- * @param octets_needed encoding length (from snmp_asn1_enc_s32t_cnt())
- * @param value is the host order s32_t value to be encoded
- * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
- *
- * @see snmp_asn1_enc_s32t_cnt()
- */
-err_t
-snmp_asn1_enc_s32t(struct pbuf *p, u16_t ofs, u16_t octets_needed, s32_t value)
-{
- u16_t plen, base;
- u8_t *msg_ptr;
-
- plen = 0;
- while (p != NULL)
- {
- base = plen;
- plen += p->len;
- if (ofs < plen)
- {
- msg_ptr = (u8_t*)p->payload;
- msg_ptr += ofs - base;
-
- while (octets_needed > 1)
- {
- octets_needed--;
- *msg_ptr = (u8_t)(value >> (octets_needed << 3));
- ofs += 1;
- if (ofs >= plen)
- {
- /* next octet in next pbuf */
- p = p->next;
- if (p == NULL) { return ERR_ARG; }
- msg_ptr = (u8_t*)p->payload;
- plen += p->len;
- }
- else
- {
- /* next octet in same pbuf */
- msg_ptr++;
- }
- }
- /* (only) one least significant octet */
- *msg_ptr = (u8_t)value;
- return ERR_OK;
- }
- p = p->next;
- }
- /* p == NULL, ofs >= plen */
- return ERR_ARG;
-}
-
-/**
- * Encodes object identifier into a pbuf chained ASN1 msg.
- *
- * @param p points to output pbuf to encode oid into
- * @param ofs points to the offset within the pbuf chain
- * @param ident_len object identifier array length
- * @param ident points to object identifier array
- * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
- */
-err_t
-snmp_asn1_enc_oid(struct pbuf *p, u16_t ofs, u8_t ident_len, s32_t *ident)
-{
- u16_t plen, base;
- u8_t *msg_ptr;
-
- plen = 0;
- while (p != NULL)
- {
- base = plen;
- plen += p->len;
- if (ofs < plen)
- {
- msg_ptr = (u8_t*)p->payload;
- msg_ptr += ofs - base;
-
- if (ident_len > 1)
- {
- if ((ident[0] == 1) && (ident[1] == 3))
- {
- /* compressed (most common) prefix .iso.org */
- *msg_ptr = 0x2b;
- }
- else
- {
- /* calculate prefix */
- *msg_ptr = (u8_t)((ident[0] * 40) + ident[1]);
- }
- ofs += 1;
- if (ofs >= plen)
- {
- /* next octet in next pbuf */
- p = p->next;
- if (p == NULL) { return ERR_ARG; }
- msg_ptr = (u8_t*)p->payload;
- plen += p->len;
- }
- else
- {
- /* next octet in same pbuf */
- msg_ptr++;
- }
- ident_len -= 2;
- ident += 2;
- }
- else
- {
-/* @bug: allow empty varbinds for symmetry (we must decode them for getnext), allow partial compression?? */
- /* ident_len <= 1, at least we need zeroDotZero (0.0) (ident_len == 2) */
- return ERR_ARG;
- }
- while (ident_len > 0)
- {
- s32_t sub_id;
- u8_t shift, tail;
-
- ident_len--;
- sub_id = *ident;
- tail = 0;
- shift = 28;
- while(shift > 0)
- {
- u8_t code;
-
- code = (u8_t)(sub_id >> shift);
- if ((code != 0) || (tail != 0))
- {
- tail = 1;
- *msg_ptr = code | 0x80;
- ofs += 1;
- if (ofs >= plen)
- {
- /* next octet in next pbuf */
- p = p->next;
- if (p == NULL) { return ERR_ARG; }
- msg_ptr = (u8_t*)p->payload;
- plen += p->len;
- }
- else
- {
- /* next octet in same pbuf */
- msg_ptr++;
- }
- }
- shift -= 7;
- }
- *msg_ptr = (u8_t)sub_id & 0x7F;
- if (ident_len > 0)
- {
- ofs += 1;
- if (ofs >= plen)
- {
- /* next octet in next pbuf */
- p = p->next;
- if (p == NULL) { return ERR_ARG; }
- msg_ptr = (u8_t*)p->payload;
- plen += p->len;
- }
- else
- {
- /* next octet in same pbuf */
- msg_ptr++;
- }
- }
- /* proceed to next sub-identifier */
- ident++;
- }
- return ERR_OK;
- }
- p = p->next;
- }
- /* p == NULL, ofs >= plen */
- return ERR_ARG;
-}
-
-/**
- * Encodes raw data (octet string, opaque) into a pbuf chained ASN1 msg.
- *
- * @param p points to output pbuf to encode raw data into
- * @param ofs points to the offset within the pbuf chain
- * @param raw_len raw data length
- * @param raw points raw data
- * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
- */
-err_t
-snmp_asn1_enc_raw(struct pbuf *p, u16_t ofs, u16_t raw_len, u8_t *raw)
-{
- u16_t plen, base;
- u8_t *msg_ptr;
-
- plen = 0;
- while (p != NULL)
- {
- base = plen;
- plen += p->len;
- if (ofs < plen)
- {
- msg_ptr = (u8_t*)p->payload;
- msg_ptr += ofs - base;
-
- while (raw_len > 1)
- {
- /* copy raw_len - 1 octets */
- raw_len--;
- *msg_ptr = *raw;
- raw++;
- ofs += 1;
- if (ofs >= plen)
- {
- /* next octet in next pbuf */
- p = p->next;
- if (p == NULL) { return ERR_ARG; }
- msg_ptr = (u8_t*)p->payload;
- plen += p->len;
- }
- else
- {
- /* next octet in same pbuf */
- msg_ptr++;
- }
- }
- if (raw_len > 0)
- {
- /* copy last or single octet */
- *msg_ptr = *raw;
- }
- return ERR_OK;
- }
- p = p->next;
- }
- /* p == NULL, ofs >= plen */
- return ERR_ARG;
-}
-
-#endif /* LWIP_SNMP */
projects / reactos.git / blobdiff