forked from osmocom/wireshark
Wrap some tvb_get_ptr calls in crc32c_tvb_offset_calculate().
This eliminates some tvb_get_ptr calls from dissectors, as part of trying to minimize if not eliminate its use in dissectors (it's a bit of what's called an "attractive nuisance", in that users who don't understand what it does - and doesn't! - do may use it in ways that are unsafe, e.g. thinking you can use it to get a null-terminated string from a packet). It also eliminates the possibility of passing one length to tvb_get_ptr() and another to crc32c_calculate(). Change-Id: I8a07168d0bc088b45d607e00c5bb1d98421ebc73 Reviewed-on: https://code.wireshark.org/review/3488 Reviewed-by: Guy Harris <guy@alum.mit.edu>
This commit is contained in:
Guy Harris
parent
c10396dbbf
commit
20c0fffc92
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@ -78,6 +78,17 @@ crc32_ccitt_tvb_offset_seed(tvbuff_t *tvb, guint offset, guint len,
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return ( crc32_ccitt_seed(buf, len, seed) );
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}
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guint32
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crc32c_tvb_offset_calculate(tvbuff_t *tvb, guint offset, guint len, guint32 seed)
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{
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const guint8* buf;
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tvb_ensure_bytes_exist(tvb, offset, len); /* len == -1 not allowed */
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buf = tvb_get_ptr(tvb, offset, len);
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return ( crc32c_calculate(buf, len, seed) );
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}
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/*
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* IEEE 802.x version (Ethernet and 802.11, at least) - byte-swap
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* the result of "crc32()".
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@ -51,6 +51,17 @@ WS_DLL_PUBLIC guint32 crc32_ccitt_tvb_offset(tvbuff_t *tvb, guint offset, guint
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@return The CRC32 CCITT checksum (using the given seed). */
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WS_DLL_PUBLIC guint32 crc32_ccitt_tvb_seed(tvbuff_t *tvb, guint len, guint32 seed);
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/** Compute CRC32C checksum of a tv buffer. If computing the
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* checksum over multiple tv buffers and you want to feed the partial CRC32
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* back in, remember to take the 1's complement of the partial CRC32 first.
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@param tvb The tv buffer containing the data.
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@param offset The offset into the tv buffer.
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@param len The number of bytes to include in the computation.
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@param seed The seed to use.
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@return The CRC32C checksum (using the given seed). */
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WS_DLL_PUBLIC guint32 crc32c_tvb_offset_calculate(tvbuff_t *tvb, guint offset,
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guint len, guint32 seed);
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/** Compute CRC32 CCITT checksum of a tv buffer. If computing the
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* checksum over multiple tv buffers and you want to feed the partial CRC32
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* back in, remember to take the 1's complement of the partial CRC32 first.
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@ -44,6 +44,7 @@
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#include "packet-scsi.h"
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#include <epan/wmem/wmem.h>
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#include <epan/range.h>
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#include <epan/crc32-tvb.h>
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#include <wsutil/crc32.h>
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void proto_register_iscsi(void);
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@ -634,7 +635,7 @@ handleHeaderDigest(iscsi_session_t *iscsi_session, proto_item *ti, tvbuff_t *tvb
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switch(iscsi_session->header_digest){
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case ISCSI_DIGEST_CRC32:
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if(available_bytes >= (headerLen + 4)) {
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guint32 crc = ~crc32c_calculate(tvb_get_ptr(tvb, offset, headerLen), headerLen, CRC32C_PRELOAD);
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guint32 crc = ~crc32c_tvb_offset_calculate(tvb, offset, headerLen, CRC32C_PRELOAD);
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guint32 sent = tvb_get_ntohl(tvb, offset + headerLen);
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if(crc == sent) {
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proto_tree_add_uint_format_value(ti, hf_iscsi_HeaderDigest32, tvb, offset + headerLen, 4, sent, "0x%08x (Good CRC32)", sent);
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@ -657,7 +658,7 @@ handleDataDigest(iscsi_session_t *iscsi_session, proto_item *ti, tvbuff_t *tvb,
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switch (iscsi_session->data_digest){
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case ISCSI_DIGEST_CRC32:
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if(available_bytes >= (dataLen + 4)) {
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guint32 crc = ~crc32c_calculate(tvb_get_ptr(tvb, offset, dataLen), dataLen, CRC32C_PRELOAD);
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guint32 crc = ~crc32c_tvb_offset_calculate(tvb, offset, dataLen, CRC32C_PRELOAD);
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guint32 sent = tvb_get_ntohl(tvb, offset + dataLen);
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if(crc == sent) {
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proto_tree_add_uint_format_value(ti, hf_iscsi_DataDigest32, tvb, offset + dataLen, 4, sent, "0x%08x (Good CRC32)", sent);
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@ -2357,7 +2358,7 @@ dissect_iscsi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean chec
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(iscsi_session->header_digest == ISCSI_DIGEST_AUTO)) {
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guint32 crc;
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/* we have enough data to test if HeaderDigest is enabled */
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crc= ~crc32c_calculate(tvb_get_ptr(tvb, offset, 48+ahsLen*4), 48+ahsLen*4, CRC32C_PRELOAD);
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crc= ~crc32c_tvb_offset_calculate(tvb, offset, 48+ahsLen*4, CRC32C_PRELOAD);
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if(crc==tvb_get_ntohl(tvb,48+ahsLen*4)){
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iscsi_session->header_digest = ISCSI_DIGEST_CRC32;
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} else {
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@ -2390,7 +2391,7 @@ dissect_iscsi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean chec
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(iscsi_session->data_digest == ISCSI_DIGEST_AUTO)) {
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guint32 crc;
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/* we have enough data to test if DataDigest is enabled */
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crc = ~crc32c_calculate(tvb_get_ptr(tvb, data_segment_offset, data_segment_len_padded), data_segment_len_padded, CRC32C_PRELOAD);
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crc = ~crc32c_tvb_offset_calculate(tvb, data_segment_offset, data_segment_len_padded, CRC32C_PRELOAD);
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if (crc == tvb_get_ntohl(tvb, data_segment_offset + data_segment_len_padded)) {
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iscsi_session->data_digest = ISCSI_DIGEST_CRC32;
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} else {
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@ -32,6 +32,7 @@
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#include <epan/conversation.h>
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#include <epan/dissectors/packet-tcp.h>
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#include <epan/expert.h>
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#include <epan/crc32-tvb.h>
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#include <wsutil/crc32.h>
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void proto_register_mpa(void);
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@ -581,8 +582,7 @@ dissect_fpdu_crc(tvbuff_t *tvb, proto_tree *tree, mpa_state_t *state,
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if (state->crc) {
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crc = ~crc32c_calculate(tvb_get_ptr(tvb, 0, length), length,
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CRC32C_PRELOAD);
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crc = ~crc32c_tvb_offset_calculate(tvb, 0, length, CRC32C_PRELOAD);
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sent_crc = tvb_get_ntohl(tvb, offset); /* crc start offset */
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@ -31,6 +31,7 @@
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#include <epan/packet.h>
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#include <epan/strutil.h>
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#include <epan/wmem/wmem.h>
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#include <epan/crc32-tvb.h>
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#include <wsutil/crc32.h>
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#include "packet-rtp.h"
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#include "packet-rtcp.h"
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@ -420,7 +421,7 @@ dissect_zrtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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}
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sent_crc = tvb_get_ntohl(tvb, msg_offset+checksum_offset);
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calc_crc = ~crc32c_calculate(tvb_get_ptr(tvb, 0, msg_offset+checksum_offset), msg_offset+checksum_offset, CRC32C_PRELOAD);
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calc_crc = ~crc32c_tvb_offset_calculate(tvb, 0, msg_offset+checksum_offset, CRC32C_PRELOAD);
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if (sent_crc == calc_crc) {
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ti = proto_tree_add_uint_format_value(zrtp_tree, hf_zrtp_checksum, tvb, msg_offset+checksum_offset, 4, sent_crc,
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