WebSockets2 - Embedded WebSockets Experiment

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Embedded WebSockets Experiment

Core/lwIP/core/snmp/asn1_enc.c@0:6dee052a3fa4, 2011-07-26 (annotated)

Committer:: nandgate
Date:: Tue Jul 26 05:30:53 2011 +0000
Revision:: 0:6dee052a3fa4

Who changed what in which revision?

User	Revision	Line number	New contents of line
nandgate	0:6dee052a3fa4	1	/**
nandgate	0:6dee052a3fa4	2	* @file
nandgate	0:6dee052a3fa4	3	* Abstract Syntax Notation One (ISO 8824, 8825) encoding
nandgate	0:6dee052a3fa4	4	*
nandgate	0:6dee052a3fa4	5	* @todo not optimised (yet), favor correctness over speed, favor speed over size
nandgate	0:6dee052a3fa4	6	*/
nandgate	0:6dee052a3fa4	7
nandgate	0:6dee052a3fa4	8	/*
nandgate	0:6dee052a3fa4	9	* Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
nandgate	0:6dee052a3fa4	10	* All rights reserved.
nandgate	0:6dee052a3fa4	11	*
nandgate	0:6dee052a3fa4	12	* Redistribution and use in source and binary forms, with or without modification,
nandgate	0:6dee052a3fa4	13	* are permitted provided that the following conditions are met:
nandgate	0:6dee052a3fa4	14	*
nandgate	0:6dee052a3fa4	15	* 1. Redistributions of source code must retain the above copyright notice,
nandgate	0:6dee052a3fa4	16	* this list of conditions and the following disclaimer.
nandgate	0:6dee052a3fa4	17	* 2. Redistributions in binary form must reproduce the above copyright notice,
nandgate	0:6dee052a3fa4	18	* this list of conditions and the following disclaimer in the documentation
nandgate	0:6dee052a3fa4	19	* and/or other materials provided with the distribution.
nandgate	0:6dee052a3fa4	20	* 3. The name of the author may not be used to endorse or promote products
nandgate	0:6dee052a3fa4	21	* derived from this software without specific prior written permission.
nandgate	0:6dee052a3fa4	22	*
nandgate	0:6dee052a3fa4	23	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
nandgate	0:6dee052a3fa4	24	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
nandgate	0:6dee052a3fa4	25	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
nandgate	0:6dee052a3fa4	26	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
nandgate	0:6dee052a3fa4	27	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
nandgate	0:6dee052a3fa4	28	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
nandgate	0:6dee052a3fa4	29	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
nandgate	0:6dee052a3fa4	30	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
nandgate	0:6dee052a3fa4	31	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
nandgate	0:6dee052a3fa4	32	* OF SUCH DAMAGE.
nandgate	0:6dee052a3fa4	33	*
nandgate	0:6dee052a3fa4	34	* Author: Christiaan Simons <christiaan.simons@axon.tv>
nandgate	0:6dee052a3fa4	35	*/
nandgate	0:6dee052a3fa4	36
nandgate	0:6dee052a3fa4	37	#include "lwip/opt.h"
nandgate	0:6dee052a3fa4	38
nandgate	0:6dee052a3fa4	39	#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
nandgate	0:6dee052a3fa4	40
nandgate	0:6dee052a3fa4	41	#include "lwip/snmp_asn1.h"
nandgate	0:6dee052a3fa4	42
nandgate	0:6dee052a3fa4	43	/**
nandgate	0:6dee052a3fa4	44	* Returns octet count for length.
nandgate	0:6dee052a3fa4	45	*
nandgate	0:6dee052a3fa4	46	* @param length
nandgate	0:6dee052a3fa4	47	* @param octets_needed points to the return value
nandgate	0:6dee052a3fa4	48	*/
nandgate	0:6dee052a3fa4	49	void
nandgate	0:6dee052a3fa4	50	snmp_asn1_enc_length_cnt(u16_t length, u8_t *octets_needed)
nandgate	0:6dee052a3fa4	51	{
nandgate	0:6dee052a3fa4	52	if (length < 0x80U)
nandgate	0:6dee052a3fa4	53	{
nandgate	0:6dee052a3fa4	54	*octets_needed = 1;
nandgate	0:6dee052a3fa4	55	}
nandgate	0:6dee052a3fa4	56	else if (length < 0x100U)
nandgate	0:6dee052a3fa4	57	{
nandgate	0:6dee052a3fa4	58	*octets_needed = 2;
nandgate	0:6dee052a3fa4	59	}
nandgate	0:6dee052a3fa4	60	else
nandgate	0:6dee052a3fa4	61	{
nandgate	0:6dee052a3fa4	62	*octets_needed = 3;
nandgate	0:6dee052a3fa4	63	}
nandgate	0:6dee052a3fa4	64	}
nandgate	0:6dee052a3fa4	65
nandgate	0:6dee052a3fa4	66	/**
nandgate	0:6dee052a3fa4	67	* Returns octet count for an u32_t.
nandgate	0:6dee052a3fa4	68	*
nandgate	0:6dee052a3fa4	69	* @param value
nandgate	0:6dee052a3fa4	70	* @param octets_needed points to the return value
nandgate	0:6dee052a3fa4	71	*
nandgate	0:6dee052a3fa4	72	* @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded
nandgate	0:6dee052a3fa4	73	* as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value
nandgate	0:6dee052a3fa4	74	* of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!!
nandgate	0:6dee052a3fa4	75	*/
nandgate	0:6dee052a3fa4	76	void
nandgate	0:6dee052a3fa4	77	snmp_asn1_enc_u32t_cnt(u32_t value, u16_t *octets_needed)
nandgate	0:6dee052a3fa4	78	{
nandgate	0:6dee052a3fa4	79	if (value < 0x80UL)
nandgate	0:6dee052a3fa4	80	{
nandgate	0:6dee052a3fa4	81	*octets_needed = 1;
nandgate	0:6dee052a3fa4	82	}
nandgate	0:6dee052a3fa4	83	else if (value < 0x8000UL)
nandgate	0:6dee052a3fa4	84	{
nandgate	0:6dee052a3fa4	85	*octets_needed = 2;
nandgate	0:6dee052a3fa4	86	}
nandgate	0:6dee052a3fa4	87	else if (value < 0x800000UL)
nandgate	0:6dee052a3fa4	88	{
nandgate	0:6dee052a3fa4	89	*octets_needed = 3;
nandgate	0:6dee052a3fa4	90	}
nandgate	0:6dee052a3fa4	91	else if (value < 0x80000000UL)
nandgate	0:6dee052a3fa4	92	{
nandgate	0:6dee052a3fa4	93	*octets_needed = 4;
nandgate	0:6dee052a3fa4	94	}
nandgate	0:6dee052a3fa4	95	else
nandgate	0:6dee052a3fa4	96	{
nandgate	0:6dee052a3fa4	97	*octets_needed = 5;
nandgate	0:6dee052a3fa4	98	}
nandgate	0:6dee052a3fa4	99	}
nandgate	0:6dee052a3fa4	100
nandgate	0:6dee052a3fa4	101	/**
nandgate	0:6dee052a3fa4	102	* Returns octet count for an s32_t.
nandgate	0:6dee052a3fa4	103	*
nandgate	0:6dee052a3fa4	104	* @param value
nandgate	0:6dee052a3fa4	105	* @param octets_needed points to the return value
nandgate	0:6dee052a3fa4	106	*
nandgate	0:6dee052a3fa4	107	* @note ASN coded integers are _always_ signed.
nandgate	0:6dee052a3fa4	108	*/
nandgate	0:6dee052a3fa4	109	void
nandgate	0:6dee052a3fa4	110	snmp_asn1_enc_s32t_cnt(s32_t value, u16_t *octets_needed)
nandgate	0:6dee052a3fa4	111	{
nandgate	0:6dee052a3fa4	112	if (value < 0)
nandgate	0:6dee052a3fa4	113	{
nandgate	0:6dee052a3fa4	114	value = ~value;
nandgate	0:6dee052a3fa4	115	}
nandgate	0:6dee052a3fa4	116	if (value < 0x80L)
nandgate	0:6dee052a3fa4	117	{
nandgate	0:6dee052a3fa4	118	*octets_needed = 1;
nandgate	0:6dee052a3fa4	119	}
nandgate	0:6dee052a3fa4	120	else if (value < 0x8000L)
nandgate	0:6dee052a3fa4	121	{
nandgate	0:6dee052a3fa4	122	*octets_needed = 2;
nandgate	0:6dee052a3fa4	123	}
nandgate	0:6dee052a3fa4	124	else if (value < 0x800000L)
nandgate	0:6dee052a3fa4	125	{
nandgate	0:6dee052a3fa4	126	*octets_needed = 3;
nandgate	0:6dee052a3fa4	127	}
nandgate	0:6dee052a3fa4	128	else
nandgate	0:6dee052a3fa4	129	{
nandgate	0:6dee052a3fa4	130	*octets_needed = 4;
nandgate	0:6dee052a3fa4	131	}
nandgate	0:6dee052a3fa4	132	}
nandgate	0:6dee052a3fa4	133
nandgate	0:6dee052a3fa4	134	/**
nandgate	0:6dee052a3fa4	135	* Returns octet count for an object identifier.
nandgate	0:6dee052a3fa4	136	*
nandgate	0:6dee052a3fa4	137	* @param ident_len object identifier array length
nandgate	0:6dee052a3fa4	138	* @param ident points to object identifier array
nandgate	0:6dee052a3fa4	139	* @param octets_needed points to the return value
nandgate	0:6dee052a3fa4	140	*/
nandgate	0:6dee052a3fa4	141	void
nandgate	0:6dee052a3fa4	142	snmp_asn1_enc_oid_cnt(u8_t ident_len, s32_t ident, u16_t octets_needed)
nandgate	0:6dee052a3fa4	143	{
nandgate	0:6dee052a3fa4	144	s32_t sub_id;
nandgate	0:6dee052a3fa4	145	u8_t cnt;
nandgate	0:6dee052a3fa4	146
nandgate	0:6dee052a3fa4	147	cnt = 0;
nandgate	0:6dee052a3fa4	148	if (ident_len > 1)
nandgate	0:6dee052a3fa4	149	{
nandgate	0:6dee052a3fa4	150	/* compressed prefix in one octet */
nandgate	0:6dee052a3fa4	151	cnt++;
nandgate	0:6dee052a3fa4	152	ident_len -= 2;
nandgate	0:6dee052a3fa4	153	ident += 2;
nandgate	0:6dee052a3fa4	154	}
nandgate	0:6dee052a3fa4	155	while(ident_len > 0)
nandgate	0:6dee052a3fa4	156	{
nandgate	0:6dee052a3fa4	157	ident_len--;
nandgate	0:6dee052a3fa4	158	sub_id = *ident;
nandgate	0:6dee052a3fa4	159
nandgate	0:6dee052a3fa4	160	sub_id >>= 7;
nandgate	0:6dee052a3fa4	161	cnt++;
nandgate	0:6dee052a3fa4	162	while(sub_id > 0)
nandgate	0:6dee052a3fa4	163	{
nandgate	0:6dee052a3fa4	164	sub_id >>= 7;
nandgate	0:6dee052a3fa4	165	cnt++;
nandgate	0:6dee052a3fa4	166	}
nandgate	0:6dee052a3fa4	167	ident++;
nandgate	0:6dee052a3fa4	168	}
nandgate	0:6dee052a3fa4	169	*octets_needed = cnt;
nandgate	0:6dee052a3fa4	170	}
nandgate	0:6dee052a3fa4	171
nandgate	0:6dee052a3fa4	172	/**
nandgate	0:6dee052a3fa4	173	* Encodes ASN type field into a pbuf chained ASN1 msg.
nandgate	0:6dee052a3fa4	174	*
nandgate	0:6dee052a3fa4	175	* @param p points to output pbuf to encode value into
nandgate	0:6dee052a3fa4	176	* @param ofs points to the offset within the pbuf chain
nandgate	0:6dee052a3fa4	177	* @param type input ASN1 type
nandgate	0:6dee052a3fa4	178	* @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
nandgate	0:6dee052a3fa4	179	*/
nandgate	0:6dee052a3fa4	180	err_t
nandgate	0:6dee052a3fa4	181	snmp_asn1_enc_type(struct pbuf *p, u16_t ofs, u8_t type)
nandgate	0:6dee052a3fa4	182	{
nandgate	0:6dee052a3fa4	183	u16_t plen, base;
nandgate	0:6dee052a3fa4	184	u8_t *msg_ptr;
nandgate	0:6dee052a3fa4	185
nandgate	0:6dee052a3fa4	186	plen = 0;
nandgate	0:6dee052a3fa4	187	while (p != NULL)
nandgate	0:6dee052a3fa4	188	{
nandgate	0:6dee052a3fa4	189	base = plen;
nandgate	0:6dee052a3fa4	190	plen += p->len;
nandgate	0:6dee052a3fa4	191	if (ofs < plen)
nandgate	0:6dee052a3fa4	192	{
nandgate	0:6dee052a3fa4	193	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	194	msg_ptr += ofs - base;
nandgate	0:6dee052a3fa4	195	*msg_ptr = type;
nandgate	0:6dee052a3fa4	196	return ERR_OK;
nandgate	0:6dee052a3fa4	197	}
nandgate	0:6dee052a3fa4	198	p = p->next;
nandgate	0:6dee052a3fa4	199	}
nandgate	0:6dee052a3fa4	200	/* p == NULL, ofs >= plen */
nandgate	0:6dee052a3fa4	201	return ERR_ARG;
nandgate	0:6dee052a3fa4	202	}
nandgate	0:6dee052a3fa4	203
nandgate	0:6dee052a3fa4	204	/**
nandgate	0:6dee052a3fa4	205	* Encodes host order length field into a pbuf chained ASN1 msg.
nandgate	0:6dee052a3fa4	206	*
nandgate	0:6dee052a3fa4	207	* @param p points to output pbuf to encode length into
nandgate	0:6dee052a3fa4	208	* @param ofs points to the offset within the pbuf chain
nandgate	0:6dee052a3fa4	209	* @param length is the host order length to be encoded
nandgate	0:6dee052a3fa4	210	* @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
nandgate	0:6dee052a3fa4	211	*/
nandgate	0:6dee052a3fa4	212	err_t
nandgate	0:6dee052a3fa4	213	snmp_asn1_enc_length(struct pbuf *p, u16_t ofs, u16_t length)
nandgate	0:6dee052a3fa4	214	{
nandgate	0:6dee052a3fa4	215	u16_t plen, base;
nandgate	0:6dee052a3fa4	216	u8_t *msg_ptr;
nandgate	0:6dee052a3fa4	217
nandgate	0:6dee052a3fa4	218	plen = 0;
nandgate	0:6dee052a3fa4	219	while (p != NULL)
nandgate	0:6dee052a3fa4	220	{
nandgate	0:6dee052a3fa4	221	base = plen;
nandgate	0:6dee052a3fa4	222	plen += p->len;
nandgate	0:6dee052a3fa4	223	if (ofs < plen)
nandgate	0:6dee052a3fa4	224	{
nandgate	0:6dee052a3fa4	225	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	226	msg_ptr += ofs - base;
nandgate	0:6dee052a3fa4	227
nandgate	0:6dee052a3fa4	228	if (length < 0x80)
nandgate	0:6dee052a3fa4	229	{
nandgate	0:6dee052a3fa4	230	*msg_ptr = length;
nandgate	0:6dee052a3fa4	231	return ERR_OK;
nandgate	0:6dee052a3fa4	232	}
nandgate	0:6dee052a3fa4	233	else if (length < 0x100)
nandgate	0:6dee052a3fa4	234	{
nandgate	0:6dee052a3fa4	235	*msg_ptr = 0x81;
nandgate	0:6dee052a3fa4	236	ofs += 1;
nandgate	0:6dee052a3fa4	237	if (ofs >= plen)
nandgate	0:6dee052a3fa4	238	{
nandgate	0:6dee052a3fa4	239	/* next octet in next pbuf */
nandgate	0:6dee052a3fa4	240	p = p->next;
nandgate	0:6dee052a3fa4	241	if (p == NULL) { return ERR_ARG; }
nandgate	0:6dee052a3fa4	242	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	243	}
nandgate	0:6dee052a3fa4	244	else
nandgate	0:6dee052a3fa4	245	{
nandgate	0:6dee052a3fa4	246	/* next octet in same pbuf */
nandgate	0:6dee052a3fa4	247	msg_ptr++;
nandgate	0:6dee052a3fa4	248	}
nandgate	0:6dee052a3fa4	249	*msg_ptr = length;
nandgate	0:6dee052a3fa4	250	return ERR_OK;
nandgate	0:6dee052a3fa4	251	}
nandgate	0:6dee052a3fa4	252	else
nandgate	0:6dee052a3fa4	253	{
nandgate	0:6dee052a3fa4	254	u8_t i;
nandgate	0:6dee052a3fa4	255
nandgate	0:6dee052a3fa4	256	/* length >= 0x100 && length <= 0xFFFF */
nandgate	0:6dee052a3fa4	257	*msg_ptr = 0x82;
nandgate	0:6dee052a3fa4	258	i = 2;
nandgate	0:6dee052a3fa4	259	while (i > 0)
nandgate	0:6dee052a3fa4	260	{
nandgate	0:6dee052a3fa4	261	i--;
nandgate	0:6dee052a3fa4	262	ofs += 1;
nandgate	0:6dee052a3fa4	263	if (ofs >= plen)
nandgate	0:6dee052a3fa4	264	{
nandgate	0:6dee052a3fa4	265	/* next octet in next pbuf */
nandgate	0:6dee052a3fa4	266	p = p->next;
nandgate	0:6dee052a3fa4	267	if (p == NULL) { return ERR_ARG; }
nandgate	0:6dee052a3fa4	268	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	269	plen += p->len;
nandgate	0:6dee052a3fa4	270	}
nandgate	0:6dee052a3fa4	271	else
nandgate	0:6dee052a3fa4	272	{
nandgate	0:6dee052a3fa4	273	/* next octet in same pbuf */
nandgate	0:6dee052a3fa4	274	msg_ptr++;
nandgate	0:6dee052a3fa4	275	}
nandgate	0:6dee052a3fa4	276	if (i == 0)
nandgate	0:6dee052a3fa4	277	{
nandgate	0:6dee052a3fa4	278	/* least significant length octet */
nandgate	0:6dee052a3fa4	279	*msg_ptr = length;
nandgate	0:6dee052a3fa4	280	}
nandgate	0:6dee052a3fa4	281	else
nandgate	0:6dee052a3fa4	282	{
nandgate	0:6dee052a3fa4	283	/* most significant length octet */
nandgate	0:6dee052a3fa4	284	*msg_ptr = length >> 8;
nandgate	0:6dee052a3fa4	285	}
nandgate	0:6dee052a3fa4	286	}
nandgate	0:6dee052a3fa4	287	return ERR_OK;
nandgate	0:6dee052a3fa4	288	}
nandgate	0:6dee052a3fa4	289	}
nandgate	0:6dee052a3fa4	290	p = p->next;
nandgate	0:6dee052a3fa4	291	}
nandgate	0:6dee052a3fa4	292	/* p == NULL, ofs >= plen */
nandgate	0:6dee052a3fa4	293	return ERR_ARG;
nandgate	0:6dee052a3fa4	294	}
nandgate	0:6dee052a3fa4	295
nandgate	0:6dee052a3fa4	296	/**
nandgate	0:6dee052a3fa4	297	* Encodes u32_t (counter, gauge, timeticks) into a pbuf chained ASN1 msg.
nandgate	0:6dee052a3fa4	298	*
nandgate	0:6dee052a3fa4	299	* @param p points to output pbuf to encode value into
nandgate	0:6dee052a3fa4	300	* @param ofs points to the offset within the pbuf chain
nandgate	0:6dee052a3fa4	301	* @param octets_needed encoding length (from snmp_asn1_enc_u32t_cnt())
nandgate	0:6dee052a3fa4	302	* @param value is the host order u32_t value to be encoded
nandgate	0:6dee052a3fa4	303	* @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
nandgate	0:6dee052a3fa4	304	*
nandgate	0:6dee052a3fa4	305	* @see snmp_asn1_enc_u32t_cnt()
nandgate	0:6dee052a3fa4	306	*/
nandgate	0:6dee052a3fa4	307	err_t
nandgate	0:6dee052a3fa4	308	snmp_asn1_enc_u32t(struct pbuf *p, u16_t ofs, u8_t octets_needed, u32_t value)
nandgate	0:6dee052a3fa4	309	{
nandgate	0:6dee052a3fa4	310	u16_t plen, base;
nandgate	0:6dee052a3fa4	311	u8_t *msg_ptr;
nandgate	0:6dee052a3fa4	312
nandgate	0:6dee052a3fa4	313	plen = 0;
nandgate	0:6dee052a3fa4	314	while (p != NULL)
nandgate	0:6dee052a3fa4	315	{
nandgate	0:6dee052a3fa4	316	base = plen;
nandgate	0:6dee052a3fa4	317	plen += p->len;
nandgate	0:6dee052a3fa4	318	if (ofs < plen)
nandgate	0:6dee052a3fa4	319	{
nandgate	0:6dee052a3fa4	320	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	321	msg_ptr += ofs - base;
nandgate	0:6dee052a3fa4	322
nandgate	0:6dee052a3fa4	323	if (octets_needed == 5)
nandgate	0:6dee052a3fa4	324	{
nandgate	0:6dee052a3fa4	325	/* not enough bits in 'value' add leading 0x00 */
nandgate	0:6dee052a3fa4	326	octets_needed--;
nandgate	0:6dee052a3fa4	327	*msg_ptr = 0x00;
nandgate	0:6dee052a3fa4	328	ofs += 1;
nandgate	0:6dee052a3fa4	329	if (ofs >= plen)
nandgate	0:6dee052a3fa4	330	{
nandgate	0:6dee052a3fa4	331	/* next octet in next pbuf */
nandgate	0:6dee052a3fa4	332	p = p->next;
nandgate	0:6dee052a3fa4	333	if (p == NULL) { return ERR_ARG; }
nandgate	0:6dee052a3fa4	334	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	335	plen += p->len;
nandgate	0:6dee052a3fa4	336	}
nandgate	0:6dee052a3fa4	337	else
nandgate	0:6dee052a3fa4	338	{
nandgate	0:6dee052a3fa4	339	/* next octet in same pbuf */
nandgate	0:6dee052a3fa4	340	msg_ptr++;
nandgate	0:6dee052a3fa4	341	}
nandgate	0:6dee052a3fa4	342	}
nandgate	0:6dee052a3fa4	343	while (octets_needed > 1)
nandgate	0:6dee052a3fa4	344	{
nandgate	0:6dee052a3fa4	345	octets_needed--;
nandgate	0:6dee052a3fa4	346	*msg_ptr = value >> (octets_needed << 3);
nandgate	0:6dee052a3fa4	347	ofs += 1;
nandgate	0:6dee052a3fa4	348	if (ofs >= plen)
nandgate	0:6dee052a3fa4	349	{
nandgate	0:6dee052a3fa4	350	/* next octet in next pbuf */
nandgate	0:6dee052a3fa4	351	p = p->next;
nandgate	0:6dee052a3fa4	352	if (p == NULL) { return ERR_ARG; }
nandgate	0:6dee052a3fa4	353	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	354	plen += p->len;
nandgate	0:6dee052a3fa4	355	}
nandgate	0:6dee052a3fa4	356	else
nandgate	0:6dee052a3fa4	357	{
nandgate	0:6dee052a3fa4	358	/* next octet in same pbuf */
nandgate	0:6dee052a3fa4	359	msg_ptr++;
nandgate	0:6dee052a3fa4	360	}
nandgate	0:6dee052a3fa4	361	}
nandgate	0:6dee052a3fa4	362	/* (only) one least significant octet */
nandgate	0:6dee052a3fa4	363	*msg_ptr = value;
nandgate	0:6dee052a3fa4	364	return ERR_OK;
nandgate	0:6dee052a3fa4	365	}
nandgate	0:6dee052a3fa4	366	p = p->next;
nandgate	0:6dee052a3fa4	367	}
nandgate	0:6dee052a3fa4	368	/* p == NULL, ofs >= plen */
nandgate	0:6dee052a3fa4	369	return ERR_ARG;
nandgate	0:6dee052a3fa4	370	}
nandgate	0:6dee052a3fa4	371
nandgate	0:6dee052a3fa4	372	/**
nandgate	0:6dee052a3fa4	373	* Encodes s32_t integer into a pbuf chained ASN1 msg.
nandgate	0:6dee052a3fa4	374	*
nandgate	0:6dee052a3fa4	375	* @param p points to output pbuf to encode value into
nandgate	0:6dee052a3fa4	376	* @param ofs points to the offset within the pbuf chain
nandgate	0:6dee052a3fa4	377	* @param octets_needed encoding length (from snmp_asn1_enc_s32t_cnt())
nandgate	0:6dee052a3fa4	378	* @param value is the host order s32_t value to be encoded
nandgate	0:6dee052a3fa4	379	* @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
nandgate	0:6dee052a3fa4	380	*
nandgate	0:6dee052a3fa4	381	* @see snmp_asn1_enc_s32t_cnt()
nandgate	0:6dee052a3fa4	382	*/
nandgate	0:6dee052a3fa4	383	err_t
nandgate	0:6dee052a3fa4	384	snmp_asn1_enc_s32t(struct pbuf *p, u16_t ofs, u8_t octets_needed, s32_t value)
nandgate	0:6dee052a3fa4	385	{
nandgate	0:6dee052a3fa4	386	u16_t plen, base;
nandgate	0:6dee052a3fa4	387	u8_t *msg_ptr;
nandgate	0:6dee052a3fa4	388
nandgate	0:6dee052a3fa4	389	plen = 0;
nandgate	0:6dee052a3fa4	390	while (p != NULL)
nandgate	0:6dee052a3fa4	391	{
nandgate	0:6dee052a3fa4	392	base = plen;
nandgate	0:6dee052a3fa4	393	plen += p->len;
nandgate	0:6dee052a3fa4	394	if (ofs < plen)
nandgate	0:6dee052a3fa4	395	{
nandgate	0:6dee052a3fa4	396	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	397	msg_ptr += ofs - base;
nandgate	0:6dee052a3fa4	398
nandgate	0:6dee052a3fa4	399	while (octets_needed > 1)
nandgate	0:6dee052a3fa4	400	{
nandgate	0:6dee052a3fa4	401	octets_needed--;
nandgate	0:6dee052a3fa4	402	*msg_ptr = value >> (octets_needed << 3);
nandgate	0:6dee052a3fa4	403	ofs += 1;
nandgate	0:6dee052a3fa4	404	if (ofs >= plen)
nandgate	0:6dee052a3fa4	405	{
nandgate	0:6dee052a3fa4	406	/* next octet in next pbuf */
nandgate	0:6dee052a3fa4	407	p = p->next;
nandgate	0:6dee052a3fa4	408	if (p == NULL) { return ERR_ARG; }
nandgate	0:6dee052a3fa4	409	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	410	plen += p->len;
nandgate	0:6dee052a3fa4	411	}
nandgate	0:6dee052a3fa4	412	else
nandgate	0:6dee052a3fa4	413	{
nandgate	0:6dee052a3fa4	414	/* next octet in same pbuf */
nandgate	0:6dee052a3fa4	415	msg_ptr++;
nandgate	0:6dee052a3fa4	416	}
nandgate	0:6dee052a3fa4	417	}
nandgate	0:6dee052a3fa4	418	/* (only) one least significant octet */
nandgate	0:6dee052a3fa4	419	*msg_ptr = value;
nandgate	0:6dee052a3fa4	420	return ERR_OK;
nandgate	0:6dee052a3fa4	421	}
nandgate	0:6dee052a3fa4	422	p = p->next;
nandgate	0:6dee052a3fa4	423	}
nandgate	0:6dee052a3fa4	424	/* p == NULL, ofs >= plen */
nandgate	0:6dee052a3fa4	425	return ERR_ARG;
nandgate	0:6dee052a3fa4	426	}
nandgate	0:6dee052a3fa4	427
nandgate	0:6dee052a3fa4	428	/**
nandgate	0:6dee052a3fa4	429	* Encodes object identifier into a pbuf chained ASN1 msg.
nandgate	0:6dee052a3fa4	430	*
nandgate	0:6dee052a3fa4	431	* @param p points to output pbuf to encode oid into
nandgate	0:6dee052a3fa4	432	* @param ofs points to the offset within the pbuf chain
nandgate	0:6dee052a3fa4	433	* @param ident_len object identifier array length
nandgate	0:6dee052a3fa4	434	* @param ident points to object identifier array
nandgate	0:6dee052a3fa4	435	* @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
nandgate	0:6dee052a3fa4	436	*/
nandgate	0:6dee052a3fa4	437	err_t
nandgate	0:6dee052a3fa4	438	snmp_asn1_enc_oid(struct pbuf p, u16_t ofs, u8_t ident_len, s32_t ident)
nandgate	0:6dee052a3fa4	439	{
nandgate	0:6dee052a3fa4	440	u16_t plen, base;
nandgate	0:6dee052a3fa4	441	u8_t *msg_ptr;
nandgate	0:6dee052a3fa4	442
nandgate	0:6dee052a3fa4	443	plen = 0;
nandgate	0:6dee052a3fa4	444	while (p != NULL)
nandgate	0:6dee052a3fa4	445	{
nandgate	0:6dee052a3fa4	446	base = plen;
nandgate	0:6dee052a3fa4	447	plen += p->len;
nandgate	0:6dee052a3fa4	448	if (ofs < plen)
nandgate	0:6dee052a3fa4	449	{
nandgate	0:6dee052a3fa4	450	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	451	msg_ptr += ofs - base;
nandgate	0:6dee052a3fa4	452
nandgate	0:6dee052a3fa4	453	if (ident_len > 1)
nandgate	0:6dee052a3fa4	454	{
nandgate	0:6dee052a3fa4	455	if ((ident[0] == 1) && (ident[1] == 3))
nandgate	0:6dee052a3fa4	456	{
nandgate	0:6dee052a3fa4	457	/* compressed (most common) prefix .iso.org */
nandgate	0:6dee052a3fa4	458	*msg_ptr = 0x2b;
nandgate	0:6dee052a3fa4	459	}
nandgate	0:6dee052a3fa4	460	else
nandgate	0:6dee052a3fa4	461	{
nandgate	0:6dee052a3fa4	462	/* calculate prefix */
nandgate	0:6dee052a3fa4	463	msg_ptr = (ident[0] 40) + ident[1];
nandgate	0:6dee052a3fa4	464	}
nandgate	0:6dee052a3fa4	465	ofs += 1;
nandgate	0:6dee052a3fa4	466	if (ofs >= plen)
nandgate	0:6dee052a3fa4	467	{
nandgate	0:6dee052a3fa4	468	/* next octet in next pbuf */
nandgate	0:6dee052a3fa4	469	p = p->next;
nandgate	0:6dee052a3fa4	470	if (p == NULL) { return ERR_ARG; }
nandgate	0:6dee052a3fa4	471	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	472	plen += p->len;
nandgate	0:6dee052a3fa4	473	}
nandgate	0:6dee052a3fa4	474	else
nandgate	0:6dee052a3fa4	475	{
nandgate	0:6dee052a3fa4	476	/* next octet in same pbuf */
nandgate	0:6dee052a3fa4	477	msg_ptr++;
nandgate	0:6dee052a3fa4	478	}
nandgate	0:6dee052a3fa4	479	ident_len -= 2;
nandgate	0:6dee052a3fa4	480	ident += 2;
nandgate	0:6dee052a3fa4	481	}
nandgate	0:6dee052a3fa4	482	else
nandgate	0:6dee052a3fa4	483	{
nandgate	0:6dee052a3fa4	484	/* @bug: allow empty varbinds for symmetry (we must decode them for getnext), allow partial compression?? */
nandgate	0:6dee052a3fa4	485	/* ident_len <= 1, at least we need zeroDotZero (0.0) (ident_len == 2) */
nandgate	0:6dee052a3fa4	486	return ERR_ARG;
nandgate	0:6dee052a3fa4	487	}
nandgate	0:6dee052a3fa4	488	while (ident_len > 0)
nandgate	0:6dee052a3fa4	489	{
nandgate	0:6dee052a3fa4	490	s32_t sub_id;
nandgate	0:6dee052a3fa4	491	u8_t shift, tail;
nandgate	0:6dee052a3fa4	492
nandgate	0:6dee052a3fa4	493	ident_len--;
nandgate	0:6dee052a3fa4	494	sub_id = *ident;
nandgate	0:6dee052a3fa4	495	tail = 0;
nandgate	0:6dee052a3fa4	496	shift = 28;
nandgate	0:6dee052a3fa4	497	while(shift > 0)
nandgate	0:6dee052a3fa4	498	{
nandgate	0:6dee052a3fa4	499	u8_t code;
nandgate	0:6dee052a3fa4	500
nandgate	0:6dee052a3fa4	501	code = sub_id >> shift;
nandgate	0:6dee052a3fa4	502	if ((code != 0) \|\| (tail != 0))
nandgate	0:6dee052a3fa4	503	{
nandgate	0:6dee052a3fa4	504	tail = 1;
nandgate	0:6dee052a3fa4	505	*msg_ptr = code \| 0x80;
nandgate	0:6dee052a3fa4	506	ofs += 1;
nandgate	0:6dee052a3fa4	507	if (ofs >= plen)
nandgate	0:6dee052a3fa4	508	{
nandgate	0:6dee052a3fa4	509	/* next octet in next pbuf */
nandgate	0:6dee052a3fa4	510	p = p->next;
nandgate	0:6dee052a3fa4	511	if (p == NULL) { return ERR_ARG; }
nandgate	0:6dee052a3fa4	512	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	513	plen += p->len;
nandgate	0:6dee052a3fa4	514	}
nandgate	0:6dee052a3fa4	515	else
nandgate	0:6dee052a3fa4	516	{
nandgate	0:6dee052a3fa4	517	/* next octet in same pbuf */
nandgate	0:6dee052a3fa4	518	msg_ptr++;
nandgate	0:6dee052a3fa4	519	}
nandgate	0:6dee052a3fa4	520	}
nandgate	0:6dee052a3fa4	521	shift -= 7;
nandgate	0:6dee052a3fa4	522	}
nandgate	0:6dee052a3fa4	523	*msg_ptr = (u8_t)sub_id & 0x7F;
nandgate	0:6dee052a3fa4	524	if (ident_len > 0)
nandgate	0:6dee052a3fa4	525	{
nandgate	0:6dee052a3fa4	526	ofs += 1;
nandgate	0:6dee052a3fa4	527	if (ofs >= plen)
nandgate	0:6dee052a3fa4	528	{
nandgate	0:6dee052a3fa4	529	/* next octet in next pbuf */
nandgate	0:6dee052a3fa4	530	p = p->next;
nandgate	0:6dee052a3fa4	531	if (p == NULL) { return ERR_ARG; }
nandgate	0:6dee052a3fa4	532	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	533	plen += p->len;
nandgate	0:6dee052a3fa4	534	}
nandgate	0:6dee052a3fa4	535	else
nandgate	0:6dee052a3fa4	536	{
nandgate	0:6dee052a3fa4	537	/* next octet in same pbuf */
nandgate	0:6dee052a3fa4	538	msg_ptr++;
nandgate	0:6dee052a3fa4	539	}
nandgate	0:6dee052a3fa4	540	}
nandgate	0:6dee052a3fa4	541	/* proceed to next sub-identifier */
nandgate	0:6dee052a3fa4	542	ident++;
nandgate	0:6dee052a3fa4	543	}
nandgate	0:6dee052a3fa4	544	return ERR_OK;
nandgate	0:6dee052a3fa4	545	}
nandgate	0:6dee052a3fa4	546	p = p->next;
nandgate	0:6dee052a3fa4	547	}
nandgate	0:6dee052a3fa4	548	/* p == NULL, ofs >= plen */
nandgate	0:6dee052a3fa4	549	return ERR_ARG;
nandgate	0:6dee052a3fa4	550	}
nandgate	0:6dee052a3fa4	551
nandgate	0:6dee052a3fa4	552	/**
nandgate	0:6dee052a3fa4	553	* Encodes raw data (octet string, opaque) into a pbuf chained ASN1 msg.
nandgate	0:6dee052a3fa4	554	*
nandgate	0:6dee052a3fa4	555	* @param p points to output pbuf to encode raw data into
nandgate	0:6dee052a3fa4	556	* @param ofs points to the offset within the pbuf chain
nandgate	0:6dee052a3fa4	557	* @param raw_len raw data length
nandgate	0:6dee052a3fa4	558	* @param raw points raw data
nandgate	0:6dee052a3fa4	559	* @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
nandgate	0:6dee052a3fa4	560	*/
nandgate	0:6dee052a3fa4	561	err_t
nandgate	0:6dee052a3fa4	562	snmp_asn1_enc_raw(struct pbuf p, u16_t ofs, u8_t raw_len, u8_t raw)
nandgate	0:6dee052a3fa4	563	{
nandgate	0:6dee052a3fa4	564	u16_t plen, base;
nandgate	0:6dee052a3fa4	565	u8_t *msg_ptr;
nandgate	0:6dee052a3fa4	566
nandgate	0:6dee052a3fa4	567	plen = 0;
nandgate	0:6dee052a3fa4	568	while (p != NULL)
nandgate	0:6dee052a3fa4	569	{
nandgate	0:6dee052a3fa4	570	base = plen;
nandgate	0:6dee052a3fa4	571	plen += p->len;
nandgate	0:6dee052a3fa4	572	if (ofs < plen)
nandgate	0:6dee052a3fa4	573	{
nandgate	0:6dee052a3fa4	574	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	575	msg_ptr += ofs - base;
nandgate	0:6dee052a3fa4	576
nandgate	0:6dee052a3fa4	577	while (raw_len > 1)
nandgate	0:6dee052a3fa4	578	{
nandgate	0:6dee052a3fa4	579	/* copy raw_len - 1 octets */
nandgate	0:6dee052a3fa4	580	raw_len--;
nandgate	0:6dee052a3fa4	581	msg_ptr = raw;
nandgate	0:6dee052a3fa4	582	raw++;
nandgate	0:6dee052a3fa4	583	ofs += 1;
nandgate	0:6dee052a3fa4	584	if (ofs >= plen)
nandgate	0:6dee052a3fa4	585	{
nandgate	0:6dee052a3fa4	586	/* next octet in next pbuf */
nandgate	0:6dee052a3fa4	587	p = p->next;
nandgate	0:6dee052a3fa4	588	if (p == NULL) { return ERR_ARG; }
nandgate	0:6dee052a3fa4	589	msg_ptr = p->payload;
nandgate	0:6dee052a3fa4	590	plen += p->len;
nandgate	0:6dee052a3fa4	591	}
nandgate	0:6dee052a3fa4	592	else
nandgate	0:6dee052a3fa4	593	{
nandgate	0:6dee052a3fa4	594	/* next octet in same pbuf */
nandgate	0:6dee052a3fa4	595	msg_ptr++;
nandgate	0:6dee052a3fa4	596	}
nandgate	0:6dee052a3fa4	597	}
nandgate	0:6dee052a3fa4	598	if (raw_len > 0)
nandgate	0:6dee052a3fa4	599	{
nandgate	0:6dee052a3fa4	600	/* copy last or single octet */
nandgate	0:6dee052a3fa4	601	msg_ptr = raw;
nandgate	0:6dee052a3fa4	602	}
nandgate	0:6dee052a3fa4	603	return ERR_OK;
nandgate	0:6dee052a3fa4	604	}
nandgate	0:6dee052a3fa4	605	p = p->next;
nandgate	0:6dee052a3fa4	606	}
nandgate	0:6dee052a3fa4	607	/* p == NULL, ofs >= plen */
nandgate	0:6dee052a3fa4	608	return ERR_ARG;
nandgate	0:6dee052a3fa4	609	}
nandgate	0:6dee052a3fa4	610
nandgate	0:6dee052a3fa4	611	#endif /* LWIP_SNMP */

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	26 Jul 2011
Imports:	159
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	2
Followers:	9

Core/lwIP/core/snmp/asn1_enc.c@0:6dee052a3fa4, 2011-07-26 (annotated)

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