diff options
Diffstat (limited to 'thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmp_asn1.c')
| -rw-r--r-- | thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmp_asn1.c | 749 |
1 files changed, 749 insertions, 0 deletions
diff --git a/thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmp_asn1.c b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmp_asn1.c new file mode 100644 index 0000000..f35b760 --- /dev/null +++ b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmp_asn1.c @@ -0,0 +1,749 @@ +/** + * @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> + * Martin Hentschel <info@cl-soft.de> + */ + +#include "lwip/apps/snmp_opts.h" + +#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */ + +#include "snmp_asn1.h" + +#define PBUF_OP_EXEC(code) \ + if ((code) != ERR_OK) { \ + return ERR_BUF; \ + } + +/** + * Encodes a TLV into a pbuf stream. + * + * @param pbuf_stream points to a pbuf stream + * @param tlv TLV to encode + * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode + */ +err_t +snmp_ans1_enc_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tlv) +{ + u8_t data; + u8_t length_bytes_required; + + /* write type */ + if ((tlv->type & SNMP_ASN1_DATATYPE_MASK) == SNMP_ASN1_DATATYPE_EXTENDED) { + /* extended format is not used by SNMP so we do not accept those values */ + return ERR_ARG; + } + if (tlv->type_len != 0) { + /* any other value as auto is not accepted for type (we always use one byte because extended syntax is prohibited) */ + return ERR_ARG; + } + + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, tlv->type)); + tlv->type_len = 1; + + /* write length */ + if (tlv->value_len <= 127) { + length_bytes_required = 1; + } else if (tlv->value_len <= 255) { + length_bytes_required = 2; + } else { + length_bytes_required = 3; + } + + /* check for forced min length */ + if (tlv->length_len > 0) { + if (tlv->length_len < length_bytes_required) { + /* unable to code requested length in requested number of bytes */ + return ERR_ARG; + } + + length_bytes_required = tlv->length_len; + } else { + tlv->length_len = length_bytes_required; + } + + if (length_bytes_required > 1) { + /* multi byte representation required */ + length_bytes_required--; + data = 0x80 | length_bytes_required; /* extended length definition, 1 length byte follows */ + + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, data)); + + while (length_bytes_required > 1) { + if (length_bytes_required == 2) { + /* append high byte */ + data = (u8_t)(tlv->value_len >> 8); + } else { + /* append leading 0x00 */ + data = 0x00; + } + + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, data)); + length_bytes_required--; + } + } + + /* append low byte */ + data = (u8_t)(tlv->value_len & 0xFF); + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, data)); + + return ERR_OK; +} + +/** + * Encodes raw data (octet string, opaque) into a pbuf chained ASN1 msg. + * + * @param pbuf_stream points to a pbuf stream + * @param raw_len raw data length + * @param raw points raw data + * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode + */ +err_t +snmp_asn1_enc_raw(struct snmp_pbuf_stream* pbuf_stream, const u8_t *raw, u16_t raw_len) +{ + PBUF_OP_EXEC(snmp_pbuf_stream_writebuf(pbuf_stream, raw, raw_len)); + + return ERR_OK; +} + +/** + * Encodes u32_t (counter, gauge, timeticks) into a pbuf chained ASN1 msg. + * + * @param pbuf_stream points to a pbuf stream + * @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 successful, ERR_ARG if we can't (or won't) encode + * + * @see snmp_asn1_enc_u32t_cnt() + */ +err_t +snmp_asn1_enc_u32t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, u32_t value) +{ + if (octets_needed > 5) { + return ERR_ARG; + } + if (octets_needed == 5) { + /* not enough bits in 'value' add leading 0x00 */ + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, 0x00)); + octets_needed--; + } + + while (octets_needed > 1) { + octets_needed--; + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(value >> (octets_needed << 3)))); + } + + /* (only) one least significant octet */ + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)value)); + + return ERR_OK; +} + +/** + * Encodes u64_t (counter64) into a pbuf chained ASN1 msg. + * + * @param pbuf_stream points to a pbuf stream + * @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 successful, ERR_ARG if we can't (or won't) encode + * + * @see snmp_asn1_enc_u64t_cnt() + */ +err_t +snmp_asn1_enc_u64t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, const u32_t* value) +{ + if (octets_needed > 9) { + return ERR_ARG; + } + if (octets_needed == 9) { + /* not enough bits in 'value' add leading 0x00 */ + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, 0x00)); + octets_needed--; + } + + while (octets_needed > 4) { + octets_needed--; + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(*value >> ((octets_needed-4) << 3)))); + } + + /* skip to low u32 */ + value++; + + while (octets_needed > 1) { + octets_needed--; + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(*value >> (octets_needed << 3)))); + } + + /* always write at least one octet (also in case of value == 0) */ + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(*value))); + + return ERR_OK; +} + +/** + * Encodes s32_t integer into a pbuf chained ASN1 msg. + * + * @param pbuf_stream points to a pbuf stream + * @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 successful, ERR_ARG if we can't (or won't) encode + * + * @see snmp_asn1_enc_s32t_cnt() + */ +err_t +snmp_asn1_enc_s32t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, s32_t value) +{ + while (octets_needed > 1) { + octets_needed--; + + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(value >> (octets_needed << 3)))); + } + + /* (only) one least significant octet */ + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)value)); + + return ERR_OK; +} + +/** + * Encodes object identifier into a pbuf chained ASN1 msg. + * + * @param pbuf_stream points to a pbuf stream + * @param oid points to object identifier array + * @param oid_len object identifier array length + * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode + */ +err_t +snmp_asn1_enc_oid(struct snmp_pbuf_stream* pbuf_stream, const u32_t *oid, u16_t oid_len) +{ + if (oid_len > 1) { + /* write compressed first two sub id's */ + u32_t compressed_byte = ((oid[0] * 40) + oid[1]); + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)compressed_byte)); + oid_len -= 2; + oid += 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 (oid_len > 0) { + u32_t sub_id; + u8_t shift, tail; + + oid_len--; + sub_id = *oid; + tail = 0; + shift = 28; + while (shift > 0) { + u8_t code; + + code = (u8_t)(sub_id >> shift); + if ((code != 0) || (tail != 0)) { + tail = 1; + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, code | 0x80)); + } + shift -= 7; + } + PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)sub_id & 0x7F)); + + /* proceed to next sub-identifier */ + oid++; + } + return ERR_OK; +} + +/** + * Returns octet count for length. + * + * @param length parameter 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 value to be encoded + * @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 u64_t. + * + * @param value value to be encoded + * @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_u64t_cnt(const u32_t *value, u16_t *octets_needed) +{ + /* check if high u32 is 0 */ + if (*value == 0x00) { + /* only low u32 is important */ + value++; + snmp_asn1_enc_u32t_cnt(*value, octets_needed); + } else { + /* low u32 does not matter for length determination */ + snmp_asn1_enc_u32t_cnt(*value, octets_needed); + *octets_needed = *octets_needed + 4; /* add the 4 bytes of low u32 */ + } +} + +/** + * Returns octet count for an s32_t. + * + * @param value value to be encoded + * @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 oid points to object identifier array + * @param oid_len object identifier array length + * @param octets_needed points to the return value + */ +void +snmp_asn1_enc_oid_cnt(const u32_t *oid, u16_t oid_len, u16_t *octets_needed) +{ + u32_t sub_id; + + *octets_needed = 0; + if (oid_len > 1) { + /* compressed prefix in one octet */ + (*octets_needed)++; + oid_len -= 2; + oid += 2; + } + while (oid_len > 0) { + oid_len--; + sub_id = *oid; + + sub_id >>= 7; + (*octets_needed)++; + while (sub_id > 0) { + sub_id >>= 7; + (*octets_needed)++; + } + oid++; + } +} + +/** + * Decodes a TLV from a pbuf stream. + * + * @param pbuf_stream points to a pbuf stream + * @param tlv returns decoded TLV + * @return ERR_OK if successful, ERR_VAL if we can't decode + */ +err_t +snmp_asn1_dec_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tlv) +{ + u8_t data; + + /* decode type first */ + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + tlv->type = data; + + if ((tlv->type & SNMP_ASN1_DATATYPE_MASK) == SNMP_ASN1_DATATYPE_EXTENDED) { + /* extended format is not used by SNMP so we do not accept those values */ + return ERR_VAL; + } + tlv->type_len = 1; + + /* now, decode length */ + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + + if (data < 0x80) { /* short form */ + tlv->length_len = 1; + tlv->value_len = data; + } else if (data > 0x80) { /* long form */ + u8_t length_bytes = data - 0x80; + tlv->length_len = length_bytes + 1; /* this byte + defined number of length bytes following */ + tlv->value_len = 0; + + while (length_bytes > 0) { + /* we only support up to u16.maxvalue-1 (2 bytes) but have to accept leading zero bytes */ + if (tlv->value_len > 0xFF) { + return ERR_VAL; + } + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + tlv->value_len <<= 8; + tlv->value_len |= data; + + /* take care for special value used for indefinite length */ + if (tlv->value_len == 0xFFFF) { + return ERR_VAL; + } + + length_bytes--; + } + } else { /* data == 0x80 indefinite length form */ + /* (not allowed for SNMP; RFC 1157, 3.2.2) */ + return ERR_VAL; + } + + return ERR_OK; +} + +/** + * Decodes positive integer (counter, gauge, timeticks) into u32_t. + * + * @param pbuf_stream points to a pbuf stream + * @param len length of the coded integer field + * @param value return host order integer + * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode + * + * @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!! + */ +err_t +snmp_asn1_dec_u32t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t *value) +{ + u8_t data; + + if ((len > 0) && (len <= 5)) { + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + + /* expecting sign bit to be zero, only unsigned please! */ + if (((len == 5) && (data == 0x00)) || ((len < 5) && ((data & 0x80) == 0))) { + *value = data; + len--; + + while (len > 0) { + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + len--; + + *value <<= 8; + *value |= data; + } + + return ERR_OK; + } + } + + return ERR_VAL; +} + +/** + * Decodes large positive integer (counter64) into 2x u32_t. + * + * @param pbuf_stream points to a pbuf stream + * @param len length of the coded integer field + * @param value return host order integer + * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode + * + * @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!! + */ +err_t +snmp_asn1_dec_u64t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t *value) +{ + u8_t data; + + if (len <= 4) { + /* high u32 is 0 */ + *value = 0; + /* directly skip to low u32 */ + value++; + } + + if ((len > 0) && (len <= 9)) { + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + + /* expecting sign bit to be zero, only unsigned please! */ + if (((len == 9) && (data == 0x00)) || ((len < 9) && ((data & 0x80) == 0))) { + *value = data; + len--; + + while (len > 0) { + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + + if (len == 4) { + /* skip to low u32 */ + value++; + *value = 0; + } else { + *value <<= 8; + } + + *value |= data; + len--; + } + + return ERR_OK; + } + } + + return ERR_VAL; +} + +/** + * Decodes integer into s32_t. + * + * @param pbuf_stream points to a pbuf stream + * @param len length of the coded integer field + * @param value return host order integer + * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode + * + * @note ASN coded integers are _always_ signed! + */ +err_t +snmp_asn1_dec_s32t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, s32_t *value) +{ +#if BYTE_ORDER == LITTLE_ENDIAN + u8_t *lsb_ptr = (u8_t*)value; +#endif +#if BYTE_ORDER == BIG_ENDIAN + u8_t *lsb_ptr = (u8_t*)value + sizeof(s32_t) - 1; +#endif + u8_t sign; + u8_t data; + + if ((len > 0) && (len < 5)) { + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + len--; + + if (data & 0x80) { + /* negative, start from -1 */ + *value = -1; + sign = 1; + *lsb_ptr &= data; + } else { + /* positive, start from 0 */ + *value = 0; + sign = 0; + *lsb_ptr |= data; + } + + /* OR/AND octets with value */ + while (len > 0) { + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + len--; + +#if BYTE_ORDER == LITTLE_ENDIAN + *value <<= 8; +#endif +#if BYTE_ORDER == BIG_ENDIAN + *value >>= 8; +#endif + + if (sign) { + *lsb_ptr |= 255; + *lsb_ptr &= data; + } else { + *lsb_ptr |= data; + } + } + + return ERR_OK; + } + + return ERR_VAL; +} + +/** + * Decodes object identifier from incoming message into array of u32_t. + * + * @param pbuf_stream points to a pbuf stream + * @param len length of the coded object identifier + * @param oid return decoded object identifier + * @param oid_len return decoded object identifier length + * @param oid_max_len size of oid buffer + * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode + */ +err_t +snmp_asn1_dec_oid(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t* oid, u8_t* oid_len, u8_t oid_max_len) +{ + u32_t *oid_ptr; + u8_t data; + + *oid_len = 0; + oid_ptr = oid; + if (len > 0) { + if (oid_max_len < 2) { + return ERR_MEM; + } + + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + len--; + + /* first compressed octet */ + if (data == 0x2B) { + /* (most) common case 1.3 (iso.org) */ + *oid_ptr = 1; + oid_ptr++; + *oid_ptr = 3; + oid_ptr++; + } else if (data < 40) { + *oid_ptr = 0; + oid_ptr++; + *oid_ptr = data; + oid_ptr++; + } else if (data < 80) { + *oid_ptr = 1; + oid_ptr++; + *oid_ptr = data - 40; + oid_ptr++; + } else { + *oid_ptr = 2; + oid_ptr++; + *oid_ptr = data - 80; + oid_ptr++; + } + *oid_len = 2; + } else { + /* accepting zero length identifiers e.g. for getnext operation. uncommon but valid */ + return ERR_OK; + } + + while ((len > 0) && (*oid_len < oid_max_len)) { + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + len--; + + if ((data & 0x80) == 0x00) { + /* sub-identifier uses single octet */ + *oid_ptr = data; + } else { + /* sub-identifier uses multiple octets */ + u32_t sub_id = (data & ~0x80); + while ((len > 0) && ((data & 0x80) != 0)) { + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data)); + len--; + + sub_id = (sub_id << 7) + (data & ~0x80); + } + + if ((data & 0x80) != 0) { + /* "more bytes following" bit still set at end of len */ + return ERR_VAL; + } + *oid_ptr = sub_id; + } + oid_ptr++; + (*oid_len)++; + } + + if (len > 0) { + /* OID to long to fit in our buffer */ + return ERR_MEM; + } + + return ERR_OK; +} + +/** + * Decodes (copies) raw data (ip-addresses, octet strings, opaque encoding) + * from incoming message into array. + * + * @param pbuf_stream points to a pbuf stream + * @param len length of the coded raw data (zero is valid, e.g. empty string!) + * @param buf return raw bytes + * @param buf_len returns length of the raw return value + * @param buf_max_len buffer size + * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode + */ +err_t +snmp_asn1_dec_raw(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u8_t *buf, u16_t* buf_len, u16_t buf_max_len) +{ + if (len > buf_max_len) { + /* not enough dst space */ + return ERR_MEM; + } + *buf_len = len; + + while (len > 0) { + PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, buf)); + buf++; + len--; + } + + return ERR_OK; +} + +#endif /* LWIP_SNMP */ |