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0db4dcafe5
In that function the "length" parameter means off-the-wire length, that is, the length declared inside the outer header. The "caplen" parameter means the amount of bytes actually available in the captured packet. gre_print_0() and the functions modelled after it passed the value of "length" instead of the value of "caplen", this could make ether_print() access beyond the memory allocated for the captured packet. Brian Carpenter had demonstrated this for the OTV case. Fix the involved functions that call ether_print() to pass the correct value and leave a comment to dismiss "caplen" later as its value can be reliably derived from the other ether_print() parameters.
75 lines
2.2 KiB
C
75 lines
2.2 KiB
C
/*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that: (1) source code
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* distributions retain the above copyright notice and this paragraph
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* in its entirety, and (2) distributions including binary code include
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* the above copyright notice and this paragraph in its entirety in
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* the documentation or other materials provided with the distribution.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND
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* WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
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* LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE.
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*
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* Original code by Francesco Fondelli (francesco dot fondelli, gmail dot com)
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*/
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/* \summary: Virtual eXtensible Local Area Network (VXLAN) printer */
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/* specification: RFC 7348 */
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <netdissect-stdinc.h>
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#include "netdissect.h"
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#include "extract.h"
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static const char tstr[] = " [|VXLAN]";
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#define VXLAN_HDR_LEN 8
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/*
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* VXLAN header, RFC7348
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* Virtual eXtensible Local Area Network (VXLAN): A Framework
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* for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks
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*
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* |R|R|R|R|I|R|R|R| Reserved |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | VXLAN Network Identifier (VNI) | Reserved |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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void
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vxlan_print(netdissect_options *ndo, const u_char *bp, u_int len)
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{
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uint8_t flags;
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uint32_t vni;
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if (len < VXLAN_HDR_LEN)
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goto trunc;
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ND_TCHECK2(*bp, VXLAN_HDR_LEN);
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flags = *bp;
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bp += 4;
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vni = EXTRACT_24BITS(bp);
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bp += 4;
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ND_PRINT((ndo, "VXLAN, "));
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ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
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ND_PRINT((ndo, "vni %u\n", vni));
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ether_print(ndo, bp, len - VXLAN_HDR_LEN, ndo->ndo_snapend - bp, NULL, NULL);
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return;
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trunc:
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ND_PRINT((ndo, "%s", tstr));
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}
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