kopia lustrzana https://github.com/F5OEO/tstools
117 wiersze
2.8 KiB
C
117 wiersze
2.8 KiB
C
/* ipv4.c */
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/*
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* Routines for dissecting ipv4
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*
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*
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* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is the MPEG TS, PS and ES tools.
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*
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* The Initial Developer of the Original Code is Amino Communications Ltd.
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* Portions created by the Initial Developer are Copyright (C) 2008
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* the Initial Developer. All Rights Reserved.
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*
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* Contributor(s):
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* Richard Watts, Kynesim <rrw@kynesim.co.uk>
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*
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* ***** END LICENSE BLOCK *****
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "ipv4.h"
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#include "misc_fns.h"
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#include <string.h>
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int ipv4_from_payload(const uint8_t *data,
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const uint32_t len,
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ipv4_header_t *out_hdr,
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uint32_t *out_st,
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uint32_t *out_len)
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{
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uint32_t cur_field;
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// Min length of an ipv4 header is 20 bytes (5 words)
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if (len < 20)
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{
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return IPV4_ERR_PKT_TOO_SHORT;
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}
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// Field 0
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cur_field = uint_32_be(&data[0]);
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out_hdr->version = (cur_field >> 28)&0xf;
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out_hdr->hdr_length = (cur_field >> 24)& 0xf;
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out_hdr->serv_type = (cur_field >> 16) & 0xff;
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out_hdr->length = (cur_field) & 0xffff;
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// Field 1
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cur_field = uint_32_be(&data[4]);
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out_hdr->ident = (cur_field >> 16) & 0xffff;
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out_hdr->flags = (cur_field >> 13) & 7;
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out_hdr->frag_offset = (cur_field & 0x1fff);
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// Field 2
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cur_field = uint_32_be(&data[8]);
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out_hdr->ttl = (cur_field >> 24) & 0xff;
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out_hdr->proto = (cur_field >> 16) & 0xff;
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out_hdr->csum = (cur_field) & 0xffff;
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// Field 3 - src address.
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out_hdr->src_addr = uint_32_be(&data[12]);
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// Field 4 - dest address.
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out_hdr->dest_addr = uint_32_be(&data[16]);
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// Now the data ..
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(*out_st) = (out_hdr->hdr_length << 2);
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(*out_len) = len - (out_hdr->hdr_length << 2);
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return 0;
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}
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int ipv4_udp_from_payload(const uint8_t *data,
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const uint32_t len,
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ipv4_udp_header_t *out_hdr,
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uint32_t *out_st,
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uint32_t *out_len)
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{
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uint32_t cur_field;
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// UDP headers are 8 bytes long.
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if (len < 8)
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{
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return IPV4_ERR_PKT_TOO_SHORT;
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}
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cur_field = uint_32_be(&data[0]);
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out_hdr->source_port = (cur_field >> 16)&0xffff;
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out_hdr->dest_port = (cur_field) & 0xffff;
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cur_field = uint_32_be(&data[4]);
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out_hdr->length = (cur_field >> 16) & 0xffff;
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out_hdr->csum = (cur_field) &0xffff;
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(*out_st) = 8;
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(*out_len) = len - 8;
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return 0;
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}
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/* End file */
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