wireshark/wiretap/busmaster_parser.lemon

%include {

/* busmaster_parser.lemon
 *
 * Wiretap Library
 * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
 *
 * Support for Busmaster log file format
 * Copyright (c) 2019 by Maksim Salau <maksim.salau@gmail.com>
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"
#include <assert.h>
#include <string.h>
#include <wiretap/file_wrappers.h>
#include "busmaster_priv.h"

extern void *BusmasterParserAlloc(void *(*mallocProc)(size_t));
extern void BusmasterParser(void *yyp, int yymajor, token_t yyminor, busmaster_state_t *state);
extern void BusmasterParserFree(void *p, void (*freeProc)(void*));

#if defined(BUSMASTER_DEBUG) || defined(BUSMASTER_PARSER_TRACE)
extern void BusmasterParserTrace(FILE *TraceFILE, char *zTracePrompt);
#undef NDEBUG
#endif

static void merge_msg_data(msg_data_t *dst, const msg_data_t *a, const msg_data_t *b)
{
    dst->length = a->length + b->length;
    memcpy(&dst->data[0], &a->data[0], a->length);
    memcpy(&dst->data[a->length], &b->data[0], b->length);
}

DIAG_OFF(unreachable-code)

}

%name BusmasterParser

%token_prefix TOKEN_

%token_type { token_t }

%token_destructor
{
    (void)state;
    (void)yypParser;
    (void)yypminor;
}

%extra_argument { busmaster_state_t* state }

%syntax_error
{
    (void)yypParser;
    (void)yyminor;

#ifdef BUSMASTER_DEBUG
    const int n = sizeof(yyTokenName) / sizeof(yyTokenName[0]);
    busmaster_debug_printf("%s: got token: %s\n", G_STRFUNC, yyTokenName[yymajor]);
    for (int i = 0; i < n; ++i) {
        int a = yy_find_shift_action((YYCODETYPE)i, yypParser->yytos->stateno);
        if (a < YYNSTATE + YYNRULE) {
            busmaster_debug_printf("%s: possible token: %s\n", G_STRFUNC, yyTokenName[i]);
        }
    }
#endif

    g_free(state->parse_error);
    state->entry_type  = LOG_ENTRY_ERROR;
    state->parse_error = g_strdup_printf("Syntax Error");
    busmaster_debug_printf("%s: Syntax Error\n", G_STRFUNC);
}

%parse_failure
{
    g_free(state->parse_error);
    state->entry_type  = LOG_ENTRY_ERROR;
    state->parse_error = g_strdup("Parse Error");
    busmaster_debug_printf("%s: Parse Error\n", G_STRFUNC);
}

%stack_overflow
{
    g_free(state->parse_error);
    state->entry_type  = LOG_ENTRY_ERROR;
    state->parse_error = g_strdup("Parser stack overflow");
    busmaster_debug_printf("%s: Parser stack overflow\n", G_STRFUNC);
}

%type msg_time { msg_time_t }
%type msg_type { msg_type_t }
%type err_msg_type { msg_type_t }
%type msg_length { guint }
%type msg_id { guint32 }

%type ref_date { msg_date_t }
%type ref_time { msg_time_t }

%type start_time { msg_date_time_t }

%type byte { guint8 }
%type data { msg_data_t }
%type data0 { msg_data_t }
%type data1 { msg_data_t }
%type data2 { msg_data_t }
%type data3 { msg_data_t }
%type data4 { msg_data_t }
%type data5 { msg_data_t }
%type data6 { msg_data_t }
%type data7 { msg_data_t }
%type data8 { msg_data_t }
%type data12 { msg_data_t }
%type data16 { msg_data_t }
%type data20 { msg_data_t }
%type data24 { msg_data_t }
%type data32 { msg_data_t }
%type data48 { msg_data_t }
%type data64 { msg_data_t }

%nonassoc INVALID_CHAR .
%nonassoc INVALID_NUMBER .

%start_symbol entry

entry ::= empty_line .
entry ::= footer_and_header .
entry ::= header .
entry ::= footer .
entry ::= msg .
entry ::= err_msg .
entry ::= j1939_msg .

empty_line ::= .
{
    busmaster_debug_printf("%s: EMPTY\n", G_STRFUNC);
    state->entry_type = LOG_ENTRY_EMPTY;
}

footer_and_header ::= footer ENDL header .
{
    busmaster_debug_printf("%s: FOOTER AND HEADER\n", G_STRFUNC);
    state->entry_type = LOG_ENTRY_FOOTER_AND_HEADER;
}

header ::= version ENDL maybe_lines
           PROTOCOL_TYPE(P) ENDL maybe_lines
           START_SESSION ENDL maybe_lines
           start_time(S) ENDL maybe_lines
           DATA_MODE(D) ENDL maybe_lines
           TIME_MODE(T) ENDL anything .
{
    busmaster_debug_printf("%s: HEADER\n", G_STRFUNC);

    state->entry_type        = LOG_ENTRY_HEADER;
    state->header.start_date = S.date;
    state->header.start_time = S.time;
    state->header.protocol   = (protocol_t)P.v0;
    state->header.data_mode  = (data_mode_t)D.v0;
    state->header.time_mode  = (time_mode_t)T.v0;
}

version ::= HEADER_VER maybe_chars .

maybe_chars ::= .
maybe_chars ::= maybe_chars HEADER_CHAR .

maybe_lines ::= .
maybe_lines ::= maybe_lines maybe_chars ENDL .

anything ::= .
anything ::= anything HEADER_CHAR .
anything ::= anything ENDL .

start_time(R) ::= START_TIME ref_date(D) ref_time(T) .
{
    R.date = D;
    R.time = T;
}

footer ::= end_time ENDL STOP_SESSION .
{
    busmaster_debug_printf("%s: FOOTER\n", G_STRFUNC);
    state->entry_type = LOG_ENTRY_FOOTER;
}

end_time ::= END_TIME ref_date ref_time .

/* <Time><Tx/Rx><Channel><CAN ID><Type><DLC><DataBytes> */
msg ::= msg_time(msg_time) MSG_DIR INT msg_id(msg_id) msg_type(msg_type) msg_length(msg_length) data(msg_data) .
{
    msg_t msg;

    /* DLC is always in DEC mode, thus we need to fix the value
     * if it was read initially as HEX. */
    if (state->header.data_mode == DATA_MODE_HEX)
    {
        msg_length = (msg_length / 16) * 10 + (msg_length % 16);
    }

    /* Fix data in RTR frames. Data may not be present,
     * but length field is set. */
    if (msg_type == MSG_TYPE_STD_RTR ||
        msg_type == MSG_TYPE_EXT_RTR)
    {
        memset(&msg_data, 0, sizeof(msg_data));
        msg_data.length = msg_length;
    }

    msg.timestamp = msg_time;
    msg.id        = msg_id;
    msg.type      = msg_type;
    msg.data      = msg_data;

    busmaster_debug_printf("%s: MSG\n", G_STRFUNC);

    state->msg = msg;
    state->entry_type = LOG_ENTRY_MSG;
}

/* <Time><Tx/Rx><Channel><CAN ID><Type><Text> */
err_msg ::= msg_time(msg_time) MSG_DIR INT INT err_msg_type(msg_type) .
{
    msg_t msg;

    msg.timestamp   = msg_time;
    msg.id          = 0;
    msg.type        = msg_type;
    msg.data.length = CAN_MAX_DLEN;

    memset(msg.data.data, 0, sizeof(msg.data.data));

    busmaster_debug_printf("%s: ERR MSG\n", G_STRFUNC);

    state->msg = msg;
    state->entry_type = LOG_ENTRY_MSG;
}

/* <Time><Channel><CAN ID><PGN><Type><Source Node><Destination Node><Priority><Tx/Rx><DLC><DataBytes> */
j1939_msg ::= msg_time(msg_time) INT msg_id(msg_id) INT J1939_MSG_TYPE INT INT INT MSG_DIR msg_length data(msg_data) .
{
    msg_t msg;

    msg.timestamp = msg_time;
    msg.id        = msg_id;
    msg.type      = MSG_TYPE_EXT;
    msg.data      = msg_data;

    busmaster_debug_printf("%s: J1939 MSG\n", G_STRFUNC);

    state->msg = msg;
    state->entry_type = LOG_ENTRY_MSG;
}

ref_date(R) ::= INT(D) COLON INT(M) COLON INT(Y) .
{
    R.year  = (guint)Y.v0;
    R.month = (guint)M.v0;
    R.day   = (guint)D.v0;
}

ref_time(R) ::= INT(H) COLON INT(M) COLON INT(S) COLON INT(U) .
{
    R.hours   = (guint)H.v0;
    R.minutes = (guint)M.v0;
    R.seconds = (guint)S.v0;
    R.micros  = (guint)U.v0 * 1000;
}

msg_time(R) ::= MSG_TIME(M) .
{
    R.hours   = (guint)M.v0;
    R.minutes = (guint)M.v1;
    R.seconds = (guint)M.v2;
    R.micros  = (guint)M.v3 * 100;
}

msg_id(R) ::= INT(V) .
{
    R = (guint)V.v0;
}

msg_length(R) ::= INT(V) .
{
    R = (guint)V.v0;
}

msg_type(R) ::= MSG_TYPE(V) .
{
    R = (msg_type_t)V.v0;
}

err_msg_type(R) ::= ERR_MSG_TYPE(V) .
{
    R = (msg_type_t)V.v0;
}

data(R) ::= data0(A) .  { R = A; }
data(R) ::= data1(A) .  { R = A; }
data(R) ::= data2(A) .  { R = A; }
data(R) ::= data3(A) .  { R = A; }
data(R) ::= data4(A) .  { R = A; }
data(R) ::= data5(A) .  { R = A; }
data(R) ::= data6(A) .  { R = A; }
data(R) ::= data7(A) .  { R = A; }
data(R) ::= data8(A) .  { R = A; }
data(R) ::= data12(A) . { R = A; }
data(R) ::= data16(A) . { R = A; }
data(R) ::= data20(A) . { R = A; }
data(R) ::= data24(A) . { R = A; }
data(R) ::= data32(A) . { R = A; }
data(R) ::= data48(A) . { R = A; }
data(R) ::= data64(A) . { R = A; }

byte(R) ::= INT(A) .
{
    R = (guint8)A.v0;
}

data0(R) ::= .
{
    R.length = 0;
}

data1(R) ::= byte(A) .
{
    R.length  = 1;
    R.data[0] = A;
}

data2(R) ::= byte(A) byte(B) .
{
    R.length  = 2;
    R.data[0] = A;
    R.data[1] = B;
}

data3(R) ::= byte(A) byte(B) byte(C) .
{
    R.length  = 3;
    R.data[0] = A;
    R.data[1] = B;
    R.data[2] = C;
}

data4(R) ::= byte(A) byte(B) byte(C) byte(D) .
{
    R.length  = 4;
    R.data[0] = A;
    R.data[1] = B;
    R.data[2] = C;
    R.data[3] = D;
}

data5(R)  ::= data4(A)  data1(B) .  { merge_msg_data(&R, &A, &B); }
data6(R)  ::= data4(A)  data2(B) .  { merge_msg_data(&R, &A, &B); }
data7(R)  ::= data4(A)  data3(B) .  { merge_msg_data(&R, &A, &B); }
data8(R)  ::= data4(A)  data4(B) .  { merge_msg_data(&R, &A, &B); }
data12(R) ::= data8(A)  data4(B) .  { merge_msg_data(&R, &A, &B); }
data16(R) ::= data8(A)  data8(B) .  { merge_msg_data(&R, &A, &B); }
data20(R) ::= data16(A) data4(B) .  { merge_msg_data(&R, &A, &B); }
data24(R) ::= data16(A) data8(B) .  { merge_msg_data(&R, &A, &B); }
data32(R) ::= data16(A) data16(B) . { merge_msg_data(&R, &A, &B); }
data48(R) ::= data32(A) data16(B) . { merge_msg_data(&R, &A, &B); }
data64(R) ::= data32(A) data32(B) . { merge_msg_data(&R, &A, &B); }

%code {

DIAG_ON(unreachable-code)

#include "busmaster_scanner_lex.h"
#include "busmaster_parser.h"

gboolean
run_busmaster_parser(busmaster_state_t *state,
                     int               *err, gchar **err_info)
{
    int       lex_code;
    yyscan_t  scanner;
    void     *parser;

    state->entry_type  = LOG_ENTRY_NONE;
    state->parse_error = NULL;
    state->err         = 0;
    state->err_info    = NULL;

    if (busmaster_lex_init_extra(state, &scanner) != 0)
    {
        *err      = errno;
        *err_info = g_strdup(g_strerror(errno));
        return FALSE;
    }

    parser = BusmasterParserAlloc(g_malloc);

#ifdef BUSMASTER_PARSER_TRACE
    BusmasterParserTrace(stdout, "BusmasterParser >> ");
#endif

    busmaster_debug_printf("%s: Starting parsing of the line\n", G_STRFUNC);

    do
    {
        lex_code = busmaster_lex(scanner);

#ifdef BUSMASTER_DEBUG
        if (lex_code)
            busmaster_debug_printf("%s: Feeding %s '%s'\n",
                                   G_STRFUNC, yyTokenName[lex_code],
                                   busmaster_get_text(scanner));
        else
            busmaster_debug_printf("%s: Feeding %s\n",
                                   G_STRFUNC, yyTokenName[lex_code]);
#endif

        BusmasterParser(parser, lex_code, state->token, state);

        if (state->err || state->err_info || state->parse_error)
            break;
    }
    while (lex_code);

    busmaster_debug_printf("%s: Done (%d)\n", G_STRFUNC, lex_code);

    BusmasterParserFree(parser, g_free);
    busmaster_lex_destroy(scanner);

    if (state->err || state->err_info || state->parse_error)
    {
        if (state->err_info)
        {
            *err_info = state->err_info;
            g_free(state->parse_error);
        }
        else
        {
            *err_info = state->parse_error;
        }

        if (state->err)
            *err = state->err;
        else
            *err = WTAP_ERR_BAD_FILE;

        return FALSE;
    }

    return TRUE;
}

}