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-rw-r--r--epan/dissectors/packet-fpp.c952
1 files changed, 952 insertions, 0 deletions
diff --git a/epan/dissectors/packet-fpp.c b/epan/dissectors/packet-fpp.c
new file mode 100644
index 00000000..2f7a82a5
--- /dev/null
+++ b/epan/dissectors/packet-fpp.c
@@ -0,0 +1,952 @@
+/* packet-fpp.c
+ * Routines for IEEE 802.3br Frame Preemption Protocol packet disassembly
+ *
+ * Copyright 2017, Anton Glukhov <anton.a.glukhov@gmail.com>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+
+#include <epan/packet.h>
+#include <wiretap/wtap.h>
+
+#include <epan/expert.h>
+#include <epan/conversation.h>
+#include <wsutil/crc32.h>
+#include <epan/crc32-tvb.h>
+#include <epan/reassemble.h>
+#include <epan/proto_data.h>
+
+void proto_register_fpp(void);
+void proto_reg_handoff_fpp(void);
+
+static int proto_fpp = -1;
+
+static dissector_handle_t fpp_handle;
+
+static int hf_fpp_preamble = -1;
+static int hf_fpp_preamble_pad = -1;
+static int hf_fpp_preamble_smd = -1;
+static int hf_fpp_preamble_frag_count = -1;
+static int hf_fpp_mdata = -1;
+static int hf_fpp_crc32 = -1;
+static int hf_fpp_crc32_status = -1;
+static int hf_fpp_mcrc32 = -1;
+static int hf_fpp_mcrc32_status = -1;
+
+static expert_field ei_fpp_crc32 = EI_INIT;
+static expert_field ei_fpp_mcrc32 = EI_INIT;
+
+static gint ett_fpp = -1;
+static gint ett_fpp_preamble = -1;
+
+static reassembly_table fpp_reassembly_table;
+
+static dissector_handle_t ethl2_handle;
+
+/* Reassembly Data */
+static int hf_fpp_fragments = -1;
+static int hf_fpp_fragment = -1;
+static int hf_fpp_fragment_overlap = -1;
+static int hf_fpp_fragment_overlap_conflicts = -1;
+static int hf_fpp_fragment_multiple_tails = -1;
+static int hf_fpp_fragment_too_long_fragment = -1;
+static int hf_fpp_fragment_error = -1;
+static int hf_fpp_fragment_count = -1;
+static int hf_fpp_reassembled_in = -1;
+static int hf_fpp_reassembled_length = -1;
+static gint ett_fpp_fragment = -1;
+static gint ett_fpp_fragments = -1;
+
+static const fragment_items fpp_frag_items = {
+ /* Fragment subtrees */
+ &ett_fpp_fragment,
+ &ett_fpp_fragments,
+ /* Fragment fields */
+ &hf_fpp_fragments,
+ &hf_fpp_fragment,
+ &hf_fpp_fragment_overlap,
+ &hf_fpp_fragment_overlap_conflicts,
+ &hf_fpp_fragment_multiple_tails,
+ &hf_fpp_fragment_too_long_fragment,
+ &hf_fpp_fragment_error,
+ &hf_fpp_fragment_count,
+ /* Reassembled in field */
+ &hf_fpp_reassembled_in,
+ /* Reassembled length field */
+ &hf_fpp_reassembled_length,
+ /* Reassembled data field */
+ NULL,
+ /* Tag */
+ "fpp fragments"
+};
+
+#define FPP_DEFAULT_PREAMBLE_LENGTH 8
+#define FPP_CRC_LENGTH 4
+
+typedef enum {
+ FPP_Packet_Expess,
+ FPP_Packet_Verify,
+ FPP_Packet_Response,
+ FPP_Packet_Init,
+ FPP_Packet_Cont,
+ FPP_Packet_Invalid,
+} fpp_packet_t;
+
+typedef enum {
+ SMD_Verify = 0x7,
+ SMD_Respond = 0x19,
+ SMD_Express = 0xd5,
+ SMD_PP_Start_0 = 0xe6,
+ SMD_PP_Start_1 = 0x4c,
+ SMD_PP_Start_2 = 0x7f,
+ SMD_PP_Start_3 = 0xb3,
+ FragCount_0 = SMD_PP_Start_0,
+ FragCount_1 = SMD_PP_Start_1,
+ FragCount_2 = SMD_PP_Start_2,
+ FragCount_3 = SMD_PP_Start_3
+} first_delim;
+
+typedef enum {
+ Octet_0x55 = 0x55,
+ SMD_PP_ContFrag_0 = 0x61,
+ SMD_PP_ContFrag_1 = 0x52,
+ SMD_PP_ContFrag_2 = 0x9e,
+ SMD_PP_ContFrag_3 = 0x2a,
+} second_delim;
+
+typedef enum {
+ CRC_CRC,
+ CRC_mCRC,
+ CRC_FALSE
+} fpp_crc_t;
+
+typedef enum {
+ PACKET_DIRECTION_INBOUND = 0x1,
+ PACKET_DIRECTION_OUTBOUND = 0x2,
+ PACKET_DIRECTION_UNKNOWN = 0x0,
+} packet_direction_enum;
+
+/* Packets with correct CRC sum */
+static const value_string preemptive_delim_desc[] = {
+ { SMD_PP_Start_0, "[Non-fragmented packet: SMD-S0]" },
+ { SMD_PP_Start_1, "[Non-fragmented packet: SMD-S1]" },
+ { SMD_PP_Start_2, "[Non-fragmented packet: SMD-S2]" },
+ { SMD_PP_Start_3, "[Non-fragmented packet: SMD-S3]" },
+ { 0x0, NULL }
+};
+
+/* Packets with correct mCRC sum */
+static const value_string initial_delim_desc[] = {
+ { SMD_PP_Start_0, "[Initial fragment: SMD-S0]" },
+ { SMD_PP_Start_1, "[Initial fragment: SMD-S1]" },
+ { SMD_PP_Start_2, "[Initial fragment: SMD-S2]" },
+ { SMD_PP_Start_3, "[Initial fragment: SMD-S3]" },
+ { 0x0, NULL }
+};
+
+/* Packets with incorrect checksum */
+static const value_string corrupted_delim_desc[] = {
+ { SMD_PP_Start_0, "[Corrupted fragment: SMD-S0]" },
+ { SMD_PP_Start_1, "[Corrupted fragment: SMD-S1]" },
+ { SMD_PP_Start_2, "[Corrupted fragment: SMD-S2]" },
+ { SMD_PP_Start_3, "[Corrupted fragment: SMD-S3]" },
+ { 0x0, NULL }
+};
+
+static const value_string continuation_delim_desc[] = {
+ { SMD_PP_ContFrag_0, "[Continuation fragment: SMD-C0]" },
+ { SMD_PP_ContFrag_1, "[Continuation fragment: SMD-C1]" },
+ { SMD_PP_ContFrag_2, "[Continuation fragment: SMD-C2]" },
+ { SMD_PP_ContFrag_3, "[Continuation fragment: SMD-C3]" },
+ { 0x0, NULL }
+};
+
+static const value_string frag_count_delim_desc[] = {
+ { FragCount_0, "[#0]"},
+ { FragCount_1, "[#1]"},
+ { FragCount_2, "[#2]"},
+ { FragCount_3, "[#3]"},
+ { 0x0, NULL }
+};
+
+static const value_string delim_desc[] = {
+ { SMD_Verify, "[SMD-V]" },
+ { SMD_Respond, "[SMD-R]" },
+ { SMD_Express, "[SMD-E]" },
+ { SMD_PP_Start_0, "[SMD-S0]" },
+ { SMD_PP_Start_1, "[SMD-S1]" },
+ { SMD_PP_Start_2, "[SMD-S2]" },
+ { SMD_PP_Start_3, "[SMD-S3]" },
+ { SMD_PP_ContFrag_0, "[SMD-C0]" },
+ { SMD_PP_ContFrag_1, "[SMD-C1]" },
+ { SMD_PP_ContFrag_2, "[SMD-C2]" },
+ { SMD_PP_ContFrag_3, "[SMD-C3]" },
+ { 0x0, NULL }
+};
+
+static guint32
+get_preamble_length(tvbuff_t *tvb) {
+
+ guint32 offset = 0;
+
+ if( 0x50 == tvb_get_guint8(tvb, offset) )
+ {
+ //First octet contains preamble alignment bits. Ignore it.
+ offset = 1;
+ }
+
+ while( tvb_get_guint8(tvb, offset) == Octet_0x55 && ( offset + 2 < tvb_reported_length(tvb) ) )
+ {
+ offset++;
+ }
+
+ guint8 smd1 = tvb_get_guint8(tvb, offset);
+
+ switch (smd1) {
+ case SMD_PP_Start_0:
+ case SMD_PP_Start_1:
+ case SMD_PP_Start_2:
+ case SMD_PP_Start_3:
+ case SMD_Verify:
+ case SMD_Respond:
+ case SMD_Express:
+ return offset + 1;
+ case SMD_PP_ContFrag_0:
+ case SMD_PP_ContFrag_1:
+ case SMD_PP_ContFrag_2:
+ case SMD_PP_ContFrag_3:
+ return offset + 2;
+ default:
+ return FPP_DEFAULT_PREAMBLE_LENGTH;
+ }
+}
+
+static fpp_crc_t
+get_crc_stat(tvbuff_t *tvb, guint32 crc, guint32 mcrc) {
+ fpp_crc_t crc_val;
+ guint32 received_crc = tvb_get_guint32(tvb, tvb_reported_length(tvb) - FPP_CRC_LENGTH, ENC_BIG_ENDIAN);
+
+ if (received_crc == crc) {
+ crc_val = CRC_CRC;
+ } else if (received_crc == mcrc) {
+ crc_val = CRC_mCRC;
+ } else {
+ crc_val = CRC_FALSE;
+ }
+ return crc_val;
+}
+
+static fpp_crc_t
+get_express_crc_stat(tvbuff_t *tvb, guint32 express_crc) {
+ fpp_crc_t crc_val;
+ guint32 received_crc = tvb_get_guint32(tvb, tvb_reported_length(tvb) - FPP_CRC_LENGTH, ENC_BIG_ENDIAN);
+
+ if (received_crc == express_crc) {
+ crc_val = CRC_CRC;
+ } else {
+ crc_val = CRC_FALSE;
+ }
+ return crc_val;
+}
+
+static fpp_packet_t
+get_packet_type(tvbuff_t *tvb) {
+ /* function analyze a packet based on preamble and ignore crc */
+
+ guint32 offset = 0;
+
+ if( 0x50 == tvb_get_guint8(tvb, offset) )
+ {
+ //First octet contains preamble alignment bits. Ignore it.
+ offset = 1;
+ }
+
+ while( tvb_get_guint8(tvb, offset) == Octet_0x55 && ( offset + 2 < tvb_reported_length(tvb) ) )
+ {
+ offset++;
+ }
+
+ guint8 smd1 = tvb_get_guint8(tvb, offset);
+ guint8 smd2 = tvb_get_guint8(tvb, offset + 1);
+
+ switch (smd1) {
+ case SMD_PP_Start_0:
+ case SMD_PP_Start_1:
+ case SMD_PP_Start_2:
+ case SMD_PP_Start_3:
+ return FPP_Packet_Init;
+ case SMD_Verify:
+ return FPP_Packet_Verify;
+ case SMD_Respond:
+ return FPP_Packet_Response;
+ case SMD_Express:
+ return FPP_Packet_Expess;
+ case SMD_PP_ContFrag_0:
+ case SMD_PP_ContFrag_1:
+ case SMD_PP_ContFrag_2:
+ case SMD_PP_ContFrag_3:
+ switch (smd2) {
+ case FragCount_0:
+ case FragCount_1:
+ case FragCount_2:
+ case FragCount_3:
+ return FPP_Packet_Cont;
+ default:
+ return FPP_Packet_Invalid;
+ }
+ default:
+ return FPP_Packet_Invalid;
+ }
+
+ return FPP_Packet_Invalid;
+}
+
+static void
+col_fstr_process(tvbuff_t *tvb, packet_info *pinfo, fpp_crc_t crc_val) {
+ guint preamble_length = get_preamble_length( tvb );
+
+ switch( get_packet_type(tvb) ) {
+ case FPP_Packet_Expess:
+ col_add_str(pinfo->cinfo, COL_INFO, "[Express]");
+ break;
+ case FPP_Packet_Verify:
+ col_add_str(pinfo->cinfo, COL_INFO, "[Verify]");
+ break;
+ case FPP_Packet_Response:
+ col_add_str(pinfo->cinfo, COL_INFO, "[Respond]");
+ break;
+ case FPP_Packet_Init:
+ if (crc_val == CRC_CRC)
+ col_add_fstr(pinfo->cinfo, COL_INFO, "%s", try_val_to_str(tvb_get_guint8(tvb, preamble_length-1), preemptive_delim_desc));
+ else if (crc_val == CRC_mCRC)
+ col_add_fstr(pinfo->cinfo, COL_INFO, "%s", try_val_to_str(tvb_get_guint8(tvb, preamble_length-1), initial_delim_desc));
+ else
+ col_add_fstr(pinfo->cinfo, COL_INFO, "%s", try_val_to_str(tvb_get_guint8(tvb, preamble_length-1), corrupted_delim_desc));
+ break;
+ case FPP_Packet_Cont:
+ col_add_fstr(pinfo->cinfo, COL_INFO, "%s %s", try_val_to_str(tvb_get_guint8(tvb, preamble_length-2), continuation_delim_desc),
+ try_val_to_str(tvb_get_guint8(tvb, preamble_length-1), frag_count_delim_desc));
+ break;
+ default:
+ break;
+ }
+}
+
+struct _fpp_ctx_t {
+ gboolean preemption;
+ guint8 frame_cnt;
+ guint8 frag_cnt;
+ guint32 size;
+ guint32 crc;
+ wmem_map_t *crc_history;
+};
+
+typedef struct _fpp_ctx_t fpp_ctx_t;
+
+static packet_direction_enum
+get_packet_direction(packet_info *pinfo) {
+ switch (pinfo->p2p_dir) {
+ case P2P_DIR_RECV:
+ return PACKET_DIRECTION_INBOUND;
+ case P2P_DIR_SENT:
+ return PACKET_DIRECTION_OUTBOUND;
+ default:
+ return PACKET_DIRECTION_UNKNOWN;
+ }
+}
+
+static void
+init_fpp_ctx(struct _fpp_ctx_t *ctx, guint8 frame_cnt, guint32 crc) {
+ ctx->preemption = TRUE;
+ ctx->frame_cnt = frame_cnt;
+ ctx->frag_cnt = FragCount_3;
+ ctx->size = 0;
+ ctx->crc = crc;
+ ctx->crc_history = wmem_map_new(wmem_epan_scope(), g_int_hash, g_int_equal);
+}
+
+static guint8
+frag_cnt_next(guint8 cur_num) {
+ switch(cur_num) {
+ case FragCount_0:
+ return FragCount_1;
+ case FragCount_1:
+ return FragCount_2;
+ case FragCount_2:
+ return FragCount_3;
+ case FragCount_3:
+ default:
+ return FragCount_0;
+ }
+}
+
+static guint8
+get_cont_by_start(guint8 start_cnt) {
+ if (start_cnt == SMD_PP_Start_0)
+ return SMD_PP_ContFrag_0;
+ else if (start_cnt == SMD_PP_Start_1)
+ return SMD_PP_ContFrag_1;
+ else if (start_cnt == SMD_PP_Start_2)
+ return SMD_PP_ContFrag_2;
+ else if (start_cnt == SMD_PP_Start_3)
+ return SMD_PP_ContFrag_3;
+ else
+ return SMD_PP_ContFrag_0;
+}
+
+struct _fpp_pdata_t {
+ /* struct for future possible usage */
+ guint32 offset;
+};
+
+typedef struct _fpp_pdata_t fpp_pdata_t;
+
+static void
+drop_conversation(conversation_t *conv) {
+ fpp_ctx_t *ctx;
+ ctx = (fpp_ctx_t*)conversation_get_proto_data(conv, proto_fpp);
+ if (ctx != NULL) {
+ wmem_free(wmem_file_scope(), ctx);
+ }
+ conversation_delete_proto_data(conv, proto_fpp);
+}
+
+static void
+drop_fragments(packet_info *pinfo) {
+ tvbuff_t *tvbuf;
+ guint interface_id;
+ packet_direction_enum packet_direction = get_packet_direction(pinfo);
+
+ if (pinfo->rec->presence_flags & WTAP_HAS_INTERFACE_ID)
+ interface_id = pinfo->rec->rec_header.packet_header.interface_id;
+ else
+ interface_id = 0;
+ interface_id = interface_id << 0x2;
+ tvbuf = fragment_delete(&fpp_reassembly_table, pinfo, interface_id | packet_direction, NULL);
+
+ if (tvbuf != NULL) {
+ tvb_free(tvbuf);
+ }
+}
+
+static tvbuff_t*
+dissect_preemption(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
+ fpp_packet_t pck_type;
+
+ guint preamble_length = get_preamble_length( tvb );
+ guint preamble_bit_length = preamble_length * 8;
+ gboolean preamble_unaligned = FALSE;
+
+ guint8 smd1 = tvb_get_guint8(tvb, preamble_length - 2);
+ guint8 smd2 = tvb_get_guint8(tvb, preamble_length - 1);
+
+ guint crc_offset = tvb_reported_length(tvb) - FPP_CRC_LENGTH;
+ gint frag_size = tvb_reported_length(tvb) - preamble_length - FPP_CRC_LENGTH;
+
+ /* Reassembly parameters. */
+ tvbuff_t *new_tvb = NULL;
+ fragment_head *frag_data;
+ gboolean save_fragmented;
+ conversation_t *conv;
+ fpp_ctx_t *ctx;
+ guint interface_id;
+ packet_direction_enum packet_direction = get_packet_direction(pinfo);
+ fpp_crc_t crc_val;
+
+ /* mCRC calculations needs previous crc */
+ guint32 crc, mcrc, prev_crc;
+
+ if (pinfo->rec->presence_flags & WTAP_HAS_INTERFACE_ID)
+ interface_id = pinfo->rec->rec_header.packet_header.interface_id;
+ else
+ interface_id = 0;
+ interface_id = interface_id << 0x2;
+
+ /* Create a tree for the preamble. */
+ proto_item *ti_preamble = proto_tree_add_item(tree, hf_fpp_preamble, tvb, 0, preamble_length, ENC_NA);
+
+ if( 0x50 == tvb_get_guint8(tvb, 0) )
+ {
+ //First octet contains preamble alignment bits.
+ preamble_bit_length -= 4;
+ preamble_unaligned = TRUE;
+ }
+
+ if( preamble_bit_length == FPP_DEFAULT_PREAMBLE_LENGTH * 8 ) {
+ proto_item_append_text(ti_preamble, " [Preamble length: Normal]" );
+ } else if( preamble_bit_length < FPP_DEFAULT_PREAMBLE_LENGTH * 8 ) {
+ proto_item_append_text(ti_preamble, " [Preamble length: Shortened by %d bits]", FPP_DEFAULT_PREAMBLE_LENGTH * 8 - preamble_bit_length );
+ } else if( preamble_bit_length > FPP_DEFAULT_PREAMBLE_LENGTH * 8 ) {
+ proto_item_append_text(ti_preamble, " [Preamble length: Lengthened by %d bits]", preamble_bit_length - FPP_DEFAULT_PREAMBLE_LENGTH * 8 );
+ }
+
+ proto_tree_add_item(tree, hf_fpp_mdata, tvb, preamble_length, frag_size, ENC_NA);
+
+ proto_tree *fpp_preamble_tree = proto_item_add_subtree(ti_preamble, ett_fpp_preamble);
+
+ if( preamble_unaligned ) {
+ proto_tree_add_item(fpp_preamble_tree, hf_fpp_preamble_pad, tvb, 0, 1, ENC_BIG_ENDIAN);
+ }
+
+ pck_type = get_packet_type(tvb);
+
+ if(pck_type == FPP_Packet_Cont)
+ {
+ proto_item *ti_smd = proto_tree_add_item(fpp_preamble_tree, hf_fpp_preamble_smd, tvb, preamble_length - 2, 1, ENC_BIG_ENDIAN);
+ proto_item *ti_fragcnt = proto_tree_add_item(fpp_preamble_tree, hf_fpp_preamble_frag_count, tvb, preamble_length - 1, 1, ENC_BIG_ENDIAN);
+ proto_item_append_text(ti_smd, " %s", try_val_to_str(tvb_get_guint8(tvb, preamble_length-2), delim_desc) );
+ proto_item_append_text(ti_fragcnt, " %s", try_val_to_str(tvb_get_guint8(tvb, preamble_length-1), frag_count_delim_desc) );
+ }
+ else
+ {
+ proto_item *ti_smd = proto_tree_add_item(fpp_preamble_tree, hf_fpp_preamble_smd, tvb, preamble_length - 1, 1, ENC_BIG_ENDIAN);
+ proto_item_append_text(ti_smd, " %s", try_val_to_str(tvb_get_guint8(tvb, preamble_length-1), delim_desc) );
+ }
+
+ prev_crc = 0;
+ conv = find_conversation_by_id(pinfo->num, CONVERSATION_NONE, interface_id | packet_direction);
+ /* Create a conversation at every SMD-S fragment.
+ Find the conversation for every SMD-C fragment.*/
+ if (pck_type == FPP_Packet_Init) {
+ /* will be used for seeding the crc calculation */
+ if (!PINFO_FD_VISITED(pinfo)) {
+ conv = conversation_new_by_id(pinfo->num, CONVERSATION_NONE, interface_id | packet_direction);
+ /* XXX Is this needed? */
+ find_conversation_pinfo(pinfo, 0);
+ }
+ }
+ else if (pck_type == FPP_Packet_Cont && conv) {
+ ctx = (fpp_ctx_t *)conversation_get_proto_data(conv, proto_fpp);
+ if (ctx) {
+ if (!PINFO_FD_VISITED(pinfo)) {
+ if ((ctx->preemption) && (ctx->frame_cnt == smd1) && (frag_cnt_next(ctx->frag_cnt) == smd2)) {
+ prev_crc = ctx->crc;
+ }
+ /* create a copy of frame number and previous crc and store in crc_history */
+ guint32 *copy_of_pinfo_num = wmem_new(wmem_epan_scope(), guint32);
+ guint32 *copy_of_prev_crc = wmem_new(wmem_epan_scope(), guint32);
+ *copy_of_pinfo_num = pinfo->num;
+ *copy_of_prev_crc = prev_crc;
+ wmem_map_insert(ctx->crc_history, copy_of_pinfo_num, copy_of_prev_crc);
+ }
+ else {
+ prev_crc = *(guint32 *)wmem_map_lookup(ctx->crc_history, &pinfo->num);
+ }
+ }
+ }
+
+ crc = GUINT32_SWAP_LE_BE(crc32_ccitt_tvb_offset_seed(tvb, preamble_length, frag_size, GUINT32_SWAP_LE_BE(prev_crc) ^ 0xffffffff));
+ mcrc = crc ^ 0xffff0000;
+ crc_val = get_crc_stat(tvb, crc, mcrc); /* might be crc if last part or mcrc if continuation */
+
+ /* fill column Info */
+ col_fstr_process(tvb, pinfo, crc_val);
+
+ if (pck_type == FPP_Packet_Init) {
+ /* Add data to this new conversation during first iteration*/
+ if (conv && !PINFO_FD_VISITED(pinfo)) {
+ ctx = wmem_new(wmem_file_scope(), struct _fpp_ctx_t);
+ init_fpp_ctx(ctx, get_cont_by_start(smd2), crc);
+ ctx->size = frag_size;
+ conversation_add_proto_data(conv, proto_fpp, ctx);
+ }
+
+ if (crc_val == CRC_CRC) {
+ /* Non-fragmented packet
+ end of continuation */
+ drop_fragments(pinfo);
+
+ if (conv && !PINFO_FD_VISITED(pinfo)) {
+ drop_conversation(conv);
+ }
+
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_crc32, hf_fpp_crc32_status, &ei_fpp_crc32, pinfo, crc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+
+ return tvb_new_subset_length(tvb, preamble_length, frag_size);
+ }
+ else if (crc_val == CRC_mCRC) {
+ /* First fragment */
+ drop_fragments(pinfo);
+
+ frag_data = fragment_add_check(&fpp_reassembly_table,
+ tvb, preamble_length, pinfo, interface_id | packet_direction, NULL,
+ 0, frag_size, TRUE);
+
+ set_address_tvb(&pinfo->dl_dst, AT_ETHER, 6, tvb, 8);
+ set_address_tvb(&pinfo->dst, AT_ETHER, 6, tvb, 8);
+ set_address_tvb(&pinfo->dl_src, AT_ETHER, 6, tvb, 14);
+ set_address_tvb(&pinfo->src, AT_ETHER, 6, tvb, 14);
+
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_mcrc32, hf_fpp_mcrc32_status, &ei_fpp_mcrc32, pinfo, mcrc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+
+ if (frag_data != NULL) {
+ col_append_frame_number(pinfo, COL_INFO, " [Reassembled in #%u]", frag_data->reassembled_in);
+ process_reassembled_data(tvb, preamble_length, pinfo,
+ "Reassembled FPP", frag_data, &fpp_frag_items,
+ NULL, tree);
+ }
+ } else {
+ /* Possibly first fragment */
+ drop_fragments(pinfo);
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_mcrc32, hf_fpp_mcrc32_status, &ei_fpp_mcrc32, pinfo, mcrc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+ }
+ } else if (pck_type == FPP_Packet_Cont) {
+ if (crc_val == CRC_mCRC) {
+ /* Continuation fragment */
+ /* Update data of this conversation */
+ if (!PINFO_FD_VISITED(pinfo) && conv) {
+ ctx = (fpp_ctx_t*)conversation_get_proto_data(conv, proto_fpp);
+ if (ctx) {
+ fpp_pdata_t *fpp_pdata = wmem_new(wmem_file_scope(), fpp_pdata_t);
+ fpp_pdata->offset = ctx->size;
+ p_add_proto_data(wmem_file_scope(), pinfo, proto_fpp, interface_id | packet_direction, fpp_pdata);
+
+ ctx->size += frag_size;
+ ctx->frag_cnt = smd2;
+ ctx->crc = crc;
+ }
+ }
+
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_mcrc32, hf_fpp_mcrc32_status, &ei_fpp_mcrc32, pinfo, mcrc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+
+ fpp_pdata_t *fpp_pdata = (fpp_pdata_t *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fpp, interface_id | packet_direction);
+ if (fpp_pdata) {
+ frag_data = fragment_add_check(&fpp_reassembly_table,
+ tvb, preamble_length, pinfo, interface_id | packet_direction, NULL,
+ fpp_pdata->offset, frag_size, TRUE);
+ if (frag_data != NULL) {
+ col_append_frame_number(pinfo, COL_INFO, " [Reassembled in #%u]", frag_data->reassembled_in);
+ process_reassembled_data(tvb, preamble_length, pinfo,
+ "Reassembled FPP", frag_data, &fpp_frag_items,
+ NULL, tree);
+ }
+ } else {
+ drop_fragments(pinfo);
+ }
+ } else if (crc_val == CRC_CRC) {
+ /* Suppose that the last fragment dissected
+ 1. preemption is active
+ 2. check frame count and frag count values
+ After these steps check crc of entire reassembled frame
+ */
+ if (conv) {
+ ctx = (fpp_ctx_t*)conversation_get_proto_data(conv, proto_fpp);
+ if ((ctx) && (ctx->preemption) && (ctx->frame_cnt == smd1) && (frag_cnt_next(ctx->frag_cnt) == smd2)) {
+ fpp_pdata_t *fpp_pdata = wmem_new(wmem_file_scope(), fpp_pdata_t);
+ if (!PINFO_FD_VISITED(pinfo)) {
+ fpp_pdata->offset = ctx->size;
+ p_add_proto_data(wmem_file_scope(), pinfo, proto_fpp, interface_id | packet_direction, fpp_pdata);
+ }
+ }
+ }
+
+ fpp_pdata_t *fpp_pdata = (fpp_pdata_t *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fpp, interface_id | packet_direction);
+ if (fpp_pdata) {
+ save_fragmented = pinfo->fragmented;
+ pinfo->fragmented = TRUE;
+ frag_data = fragment_add_check(&fpp_reassembly_table,
+ tvb, preamble_length, pinfo, interface_id | packet_direction, NULL,
+ fpp_pdata->offset, frag_size, FALSE);
+ // Attempt reassembly.
+ new_tvb = process_reassembled_data(tvb, preamble_length, pinfo,
+ "Reassembled FPP", frag_data, &fpp_frag_items,
+ NULL, tree);
+ pinfo->fragmented = save_fragmented;
+ } else {
+ drop_fragments(pinfo);
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_mcrc32, hf_fpp_mcrc32_status, &ei_fpp_mcrc32, pinfo, mcrc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+ }
+
+ if (new_tvb) {
+ /* Reassembly was successful; return the completed datagram. */
+ guint32 reassembled_crc = GUINT32_SWAP_LE_BE(crc32_ccitt_tvb_offset(new_tvb, 0, tvb_reported_length(new_tvb)));
+
+ /* Reassembly frame takes place regardless of whether the check sum was correct or not. */
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_crc32, -1, &ei_fpp_crc32, pinfo, reassembled_crc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+
+ return new_tvb;
+ } else {
+ /* Reassembly was unsuccessful; show this fragment. This may
+ just mean that we don't yet have all the fragments, so
+ we should not just continue dissecting. */
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_mcrc32, hf_fpp_mcrc32_status, &ei_fpp_mcrc32, pinfo, crc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+ return NULL;
+ }
+ } else {
+ /* Invalid packet */
+ if (!PINFO_FD_VISITED(pinfo) && conv) {
+ ctx = (fpp_ctx_t *)conversation_get_proto_data(conv, proto_fpp);
+ if (ctx) {
+ fpp_pdata_t *fpp_pdata = wmem_new(wmem_file_scope(), fpp_pdata_t);
+ fpp_pdata->offset = ctx->size;
+ p_add_proto_data(wmem_file_scope(), pinfo, proto_fpp, interface_id | packet_direction, fpp_pdata);
+
+ ctx->size += frag_size;
+ ctx->frag_cnt = smd2;
+ ctx->crc = crc;
+ }
+ }
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_mcrc32, hf_fpp_mcrc32_status, &ei_fpp_mcrc32, pinfo, mcrc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+ }
+
+ } else if (pck_type == FPP_Packet_Verify) {
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_mcrc32, -1, &ei_fpp_mcrc32, pinfo, mcrc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+ } else if (pck_type == FPP_Packet_Response) {
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_mcrc32, hf_fpp_mcrc32_status, &ei_fpp_mcrc32, pinfo, mcrc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+ }
+
+ return NULL;
+}
+
+static tvbuff_t *
+dissect_express(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 crc, fpp_crc_t crc_val) {
+
+ guint crc_offset = tvb_reported_length(tvb) - FPP_CRC_LENGTH;
+ guint offset = 0;
+ guint preamble_length = get_preamble_length( tvb );
+ guint preamble_bit_length = preamble_length * 8;
+ gboolean preamble_unaligned = FALSE;
+ guint pdu_data_len = tvb_reported_length(tvb) - preamble_length - FPP_CRC_LENGTH;
+
+
+ proto_item *ti_preamble = proto_tree_add_item(tree, hf_fpp_preamble, tvb, offset, preamble_length, ENC_NA);
+ offset += preamble_length;
+
+ if( 0x50 == tvb_get_guint8(tvb, 0) )
+ {
+ //First octet contains preamble alignment bits.
+ preamble_bit_length -= 4;
+ preamble_unaligned = TRUE;
+ }
+
+ if( preamble_bit_length == FPP_DEFAULT_PREAMBLE_LENGTH * 8 ) {
+ proto_item_append_text(ti_preamble, " [Preamble length: Normal]" );
+ } else if( preamble_bit_length < FPP_DEFAULT_PREAMBLE_LENGTH * 8 ) {
+ proto_item_append_text(ti_preamble, " [Preamble length: Shortened by %d bits]", FPP_DEFAULT_PREAMBLE_LENGTH * 8 - preamble_bit_length );
+ } else if( preamble_bit_length > FPP_DEFAULT_PREAMBLE_LENGTH * 8 ) {
+ proto_item_append_text(ti_preamble, " [Preamble length: Lengthened by %d bits]", preamble_bit_length - FPP_DEFAULT_PREAMBLE_LENGTH * 8 );
+ }
+
+
+ proto_tree_add_item(tree, hf_fpp_mdata, tvb, offset, pdu_data_len, ENC_NA);
+
+ proto_tree *fpp_preamble_tree = proto_item_add_subtree(ti_preamble, ett_fpp_preamble);
+
+ if( preamble_unaligned ) {
+ proto_tree_add_item(fpp_preamble_tree, hf_fpp_preamble_pad, tvb, 0, 1, ENC_BIG_ENDIAN);
+ }
+ proto_item *ti_smd = proto_tree_add_item(fpp_preamble_tree, hf_fpp_preamble_smd, tvb, preamble_length - 1, 1, ENC_BIG_ENDIAN);
+ proto_item_append_text(ti_smd, " [SMD-E]" );
+
+ proto_tree_add_checksum(tree, tvb, crc_offset, hf_fpp_crc32, hf_fpp_crc32_status, &ei_fpp_crc32, pinfo, crc, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+
+ if (crc_val == CRC_CRC) {
+ return tvb_new_subset_length(tvb, preamble_length, pdu_data_len);
+ }
+ return NULL;
+}
+
+static int
+dissect_fpp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
+{
+ guint32 express_crc;
+ fpp_crc_t crc_val;
+ tvbuff_t *next = tvb;
+ guint preamble_length = get_preamble_length( tvb );
+ guint pdu_data_len = tvb_reported_length(tvb) - preamble_length - FPP_CRC_LENGTH;
+
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "FPP");
+ col_clear(pinfo->cinfo,COL_INFO);
+
+ proto_item *ti = proto_tree_add_item(tree, proto_fpp, tvb, 0, -1, ENC_NA);
+
+ proto_tree *fpp_tree = proto_item_add_subtree(ti, ett_fpp);
+
+ switch (get_packet_type(tvb)) {
+ case FPP_Packet_Expess:
+ /* this is the old crc calculation which is only valid for express frames */
+ express_crc = GUINT32_SWAP_LE_BE(crc32_ccitt_tvb_offset(tvb, preamble_length, pdu_data_len));
+
+ /* is express_crc valid */
+ crc_val = get_express_crc_stat(tvb, express_crc);
+
+ /* fill column Info */
+ col_fstr_process(tvb, pinfo, crc_val);
+
+ next = dissect_express(tvb, pinfo, fpp_tree, express_crc, crc_val);
+ break;
+ case FPP_Packet_Init:
+ case FPP_Packet_Cont:
+ case FPP_Packet_Verify:
+ case FPP_Packet_Response:
+ next = dissect_preemption(tvb, pinfo, fpp_tree);
+ break;
+ default:
+ break;
+ }
+
+ if (next) {
+ call_dissector(ethl2_handle, next, pinfo, tree);
+ } else {
+ tvbuff_t *new_tvb = tvb_new_subset_length(tvb, preamble_length, pdu_data_len);
+ call_data_dissector(new_tvb, pinfo, tree);
+ }
+ return tvb_captured_length(tvb);
+}
+
+void
+proto_register_fpp(void)
+{
+ static hf_register_info hf[] = {
+ { &hf_fpp_preamble,
+ { "Preamble", "fpp.preamble",
+ FT_BYTES, BASE_NONE,
+ NULL, 0x0,
+ NULL, HFILL }
+ },
+ { &hf_fpp_preamble_pad,
+ { "Alignment padding, not part of frame", "fpp.preamble.pad",
+ FT_UINT8, BASE_HEX,
+ NULL, 0x0F,
+ NULL, HFILL }
+ },
+ { &hf_fpp_preamble_smd,
+ { "SMD", "fpp.preamble.smd",
+ FT_UINT8, BASE_HEX,
+ NULL, 0x0,
+ NULL, HFILL }
+ },
+ { &hf_fpp_preamble_frag_count,
+ { "Fragment count", "fpp.preamble.frag_count",
+ FT_UINT8, BASE_HEX,
+ NULL, 0x0,
+ NULL, HFILL }
+ },
+ { &hf_fpp_mdata,
+ { "mData", "fpp.mdata",
+ FT_BYTES, BASE_NONE,
+ NULL, 0x0,
+ NULL, HFILL }
+ },
+ { &hf_fpp_crc32,
+ { "CRC", "fpp.crc32",
+ FT_UINT32, BASE_HEX,
+ NULL, 0x0,
+ NULL, HFILL }
+ },
+ { &hf_fpp_crc32_status,
+ { "Checksum Status", "fpp.checksum.status",
+ FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x0,
+ NULL, HFILL
+ },
+ },
+ { &hf_fpp_mcrc32,
+ { "mCRC", "fpp.mcrc32",
+ FT_UINT32, BASE_HEX,
+ NULL, 0x0,
+ NULL, HFILL }
+ },
+ { &hf_fpp_mcrc32_status,
+ { "Checksum Status", "fpp.checksum.status",
+ FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x0,
+ NULL, HFILL
+ },
+ },
+
+ /* Reassembly fields. */
+ { &hf_fpp_fragments,
+ { "Message fragments", "fpp.fragments",
+ FT_NONE, BASE_NONE, NULL, 0x00, NULL, HFILL }},
+ { &hf_fpp_fragment,
+ { "Message fragment", "fpp.fragment",
+ FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL }},
+ { &hf_fpp_fragment_overlap,
+ { "Message fragment overlap", "fpp.fragment.overlap",
+ FT_BOOLEAN, BASE_NONE, NULL, 0x00, NULL, HFILL }},
+ { &hf_fpp_fragment_overlap_conflicts,
+ { "Message fragment overlapping with conflicting data", "fpp.fragment.overlap.conflicts",
+ FT_BOOLEAN, BASE_NONE, NULL, 0x00, NULL, HFILL }},
+ { &hf_fpp_fragment_multiple_tails,
+ { "Message has multiple tail fragments", "fpp.fragment.multiple_tails",
+ FT_BOOLEAN, BASE_NONE, NULL, 0x00, NULL, HFILL }},
+ { &hf_fpp_fragment_too_long_fragment,
+ { "Message fragment too long", "fpp.fragment.too_long_fragment",
+ FT_BOOLEAN, BASE_NONE, NULL, 0x00, NULL, HFILL }},
+ { &hf_fpp_fragment_error,
+ { "Message defragmentation error", "fpp.fragment.error",
+ FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL }},
+ { &hf_fpp_fragment_count,
+ { "Message fragment count", "fpp.fragment.count",
+ FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL }},
+ { &hf_fpp_reassembled_in,
+ { "Reassembled in", "fpp.reassembled.in",
+ FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL }},
+ { &hf_fpp_reassembled_length,
+ { "Reassembled fpp length", "fpp.reassembled.length",
+ FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL }},
+ };
+
+ /* Setup protocol subtree array */
+ static gint *ett[] = {
+ &ett_fpp,
+ &ett_fpp_preamble,
+ /* Reassembly subtrees. */
+ &ett_fpp_fragment,
+ &ett_fpp_fragments
+ };
+
+ static ei_register_info ei[] = {
+ { &ei_fpp_mcrc32,
+ { "fpp.mcrc32_bad", PI_CHECKSUM, PI_ERROR,
+ "Bad mCRC checksum", EXPFILL }
+ },
+ { &ei_fpp_crc32,
+ { "fpp.crc32_bad", PI_CHECKSUM, PI_ERROR,
+ "Bad CRC checksum", EXPFILL }
+ },
+ };
+
+ expert_module_t* expert_fpp;
+
+ proto_fpp = proto_register_protocol (
+ "IEEE 802.3br Frame Preemption Protocol",
+ "Frame Preemption Protocol",
+ "fpp"
+ );
+
+ proto_register_field_array(proto_fpp, hf, array_length(hf));
+ proto_register_subtree_array(ett, array_length(ett));
+ expert_fpp = expert_register_protocol(proto_fpp);
+ expert_register_field_array(expert_fpp, ei, array_length(ei));
+
+ reassembly_table_register(&fpp_reassembly_table, &addresses_reassembly_table_functions);
+
+ fpp_handle = register_dissector("fpp", dissect_fpp, proto_fpp);
+}
+
+void
+proto_reg_handoff_fpp(void)
+{
+ dissector_add_uint("wtap_encap", WTAP_ENCAP_ETHERNET_MPACKET, fpp_handle);
+
+ ethl2_handle = find_dissector_add_dependency("eth_withoutfcs", proto_fpp);
+}
+
+/*
+ * Editor modelines - https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=false:
+ */