| /** |
| * @file |
| * SNMP pbuf stream wrapper implementation (internal API, do not use in client code). |
| */ |
| |
| /* |
| * Copyright (c) 2001-2004 Swedish Institute of Computer Science. |
| * 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. |
| * |
| * This file is part of the lwIP TCP/IP stack. |
| * |
| * Author: 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_pbuf_stream.h" |
| #include "lwip/def.h" |
| #include <string.h> |
| |
| err_t |
| snmp_pbuf_stream_init(struct snmp_pbuf_stream *pbuf_stream, struct pbuf *p, u16_t offset, u16_t length) |
| { |
| pbuf_stream->offset = offset; |
| pbuf_stream->length = length; |
| pbuf_stream->pbuf = p; |
| |
| return ERR_OK; |
| } |
| |
| err_t |
| snmp_pbuf_stream_read(struct snmp_pbuf_stream *pbuf_stream, u8_t *data) |
| { |
| if (pbuf_stream->length == 0) { |
| return ERR_BUF; |
| } |
| |
| if (pbuf_copy_partial(pbuf_stream->pbuf, data, 1, pbuf_stream->offset) == 0) { |
| return ERR_BUF; |
| } |
| |
| pbuf_stream->offset++; |
| pbuf_stream->length--; |
| |
| return ERR_OK; |
| } |
| |
| err_t |
| snmp_pbuf_stream_write(struct snmp_pbuf_stream *pbuf_stream, u8_t data) |
| { |
| return snmp_pbuf_stream_writebuf(pbuf_stream, &data, 1); |
| } |
| |
| err_t |
| snmp_pbuf_stream_writebuf(struct snmp_pbuf_stream *pbuf_stream, const void *buf, u16_t buf_len) |
| { |
| if (pbuf_stream->length < buf_len) { |
| return ERR_BUF; |
| } |
| |
| if (pbuf_take_at(pbuf_stream->pbuf, buf, buf_len, pbuf_stream->offset) != ERR_OK) { |
| return ERR_BUF; |
| } |
| |
| pbuf_stream->offset += buf_len; |
| pbuf_stream->length -= buf_len; |
| |
| return ERR_OK; |
| } |
| |
| err_t |
| snmp_pbuf_stream_writeto(struct snmp_pbuf_stream *pbuf_stream, struct snmp_pbuf_stream *target_pbuf_stream, u16_t len) |
| { |
| |
| if ((pbuf_stream == NULL) || (target_pbuf_stream == NULL)) { |
| return ERR_ARG; |
| } |
| if ((len > pbuf_stream->length) || (len > target_pbuf_stream->length)) { |
| return ERR_ARG; |
| } |
| |
| if (len == 0) { |
| len = LWIP_MIN(pbuf_stream->length, target_pbuf_stream->length); |
| } |
| |
| while (len > 0) { |
| u16_t chunk_len; |
| err_t err; |
| u16_t target_offset; |
| struct pbuf *pbuf = pbuf_skip(pbuf_stream->pbuf, pbuf_stream->offset, &target_offset); |
| |
| if ((pbuf == NULL) || (pbuf->len == 0)) { |
| return ERR_BUF; |
| } |
| |
| chunk_len = LWIP_MIN(len, pbuf->len); |
| err = snmp_pbuf_stream_writebuf(target_pbuf_stream, &((u8_t *)pbuf->payload)[target_offset], chunk_len); |
| if (err != ERR_OK) { |
| return err; |
| } |
| |
| pbuf_stream->offset += chunk_len; |
| pbuf_stream->length -= chunk_len; |
| len -= chunk_len; |
| } |
| |
| return ERR_OK; |
| } |
| |
| err_t |
| snmp_pbuf_stream_seek(struct snmp_pbuf_stream *pbuf_stream, s32_t offset) |
| { |
| if ((offset < 0) || (offset > pbuf_stream->length)) { |
| /* we cannot seek backwards or forward behind stream end */ |
| return ERR_ARG; |
| } |
| |
| pbuf_stream->offset += (u16_t)offset; |
| pbuf_stream->length -= (u16_t)offset; |
| |
| return ERR_OK; |
| } |
| |
| err_t |
| snmp_pbuf_stream_seek_abs(struct snmp_pbuf_stream *pbuf_stream, u32_t offset) |
| { |
| s32_t rel_offset = offset - pbuf_stream->offset; |
| return snmp_pbuf_stream_seek(pbuf_stream, rel_offset); |
| } |
| |
| #endif /* LWIP_SNMP */ |