/* vms.c

 *

 * Wiretap Library

 * Copyright (c) 2001 by Marc Milgram <ethereal@mmilgram.NOSPAMmail.net>

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 */

/*

 * VMS TCPTRACE

 *

 * DEC/Compaq/HP/VMS Software VMS's TCPIPTRACE/TCPTRACE format is supported.

 * This is the capture program that comes with TCP/IP or UCX as supplied by

 * VMS Software, Hewlett Packard Enterprise/HP, Compaq, or Digital Equipment

 * Corporation.

 *

 * Under UCX 4.x, it is invoked as TCPIPTRACE.  Under TCPIP 5.x, it is invoked

 * as TCPTRACE.

 *

 * TCPTRACE produces an ASCII text based format that has changed slightly over

 * time.

*/

/* Notes:

 *   TCPIPtrace TCP fragments don't have the header line.  So, we are never

 *   to look for that line for the first line of a packet except the first

 *   packet.  This allows us to read fragmented packets.  Define

 *   TCPIPTRACE_FRAGMENTS_HAVE_HEADER_LINE to expect the first line to be

 *   at the start of every packet.

 */

#include "config.h"

#include "vms.h"

#include "wtap_module.h"

#include "file_wrappers.h"

#include <wsutil/strtoi.h>

#include <stdlib.h>

#include <string.h>

/* This module reads the output of the various VMS TCPIP trace utilities

 * such as TCPIPTRACE, TCPTRACE and UCX$TRACE

 *

 * It was initially based on toshiba.c and refined with code from cosine.c

--------------------------------------------------------------------------------

   Example TCPIPTRACE TCPTRACE output data:

   TCPIPtrace full display RCV packet 8 at 10-JUL-2001 14:54:19.56

   IP Version = 4,  IHL = 5,  TOS = 00,   Total Length = 84 = ^x0054

   IP Identifier  = ^x178F,  Flags (0=0,DF=0,MF=0),

         Fragment Offset = 0 = ^x0000,   Calculated Offset = 0 = ^x0000

   IP TTL = 64 = ^x40,  Protocol = 17 = ^x11,  Header Checksum = ^x4C71

   IP Source Address      = 10.12.1.80

   IP Destination Address = 10.12.1.50

   UDP Source Port = 731,   UDP Destination Port = 111

   UDP Header and Datagram Length = 64 = ^x0040,   Checksum = ^xB6C0

   50010C0A   714C1140   00008F17   54000045    0000    E..T....@.Lq...P

   27E54C3C | C0B64000   6F00DB02 | 32010C0A    0010    ...2...o.@..<L.'

   02000000   A0860100   02000000   00000000    0020    ................

   00000000   00000000   00000000   03000000    0030    ................

   06000000   01000000   A5860100   00000000    0040    ................

                                    00000000    0050    ....

--------------------------------------------------------------------------------

   Example UCX$TRACE output data:

    UCX INTERnet trace RCV packet seq # = 1 at 14-MAY-2003 11:32:10.93

   IP Version = 4,  IHL = 5,  TOS = 00,   Total Length = 583 = ^x0247

   IP Identifier  = ^x702E,  Flags (0=0,DF=0,MF=0),

         Fragment Offset = 0 = ^x0000,   Calculated Offset = 0 = ^x0000

   IP TTL = 128 = ^x80,  Protocol = 17 = ^x11,  Header Checksum = ^x70EC

   IP Source Address      = 10.20.4.159

   IP Destination Address = 10.20.4.255

   UDP Source Port = 138,   UDP Destination Port = 138

   UDP Header and Datagram Length = 563 = ^x0233,   Checksum = ^xB913

   9F04140A   70EC1180   0000702E   47020045    0000    E..G.p.....p....

   B1B80E11 | B9133302   8A008A00 | FF04140A    0010    .........3......

   46484648   45200000   1D028A00   9F04140A    0020    ...........EHFHF

   43414341   4341434D   454D4546   45454550    0030    PEEEFEMEMCACACAC

--------------------------------------------------------------------------------

   Alternate UCX$TRACE type output data:

   TCPIP INTERnet trace RCV packet seq # = 1 at 23-OCT-1998 15:19:33.29

   IP Version = 4,  IHL = 5,  TOS = 00,   Total Length = 217 = ^x00D9

   IP Identifier  = ^x0065,  Flags (0=0,DF=0,MF=0),

         Fragment Offset = 0 = ^x0000,   Calculated Offset = 0 = ^x0000

   IP TTL = 32 = ^x20,  Protocol = 17 = ^x11,  Header Checksum = ^x8F6C

   IP Source Address      = 16.20.168.93

   IP Destination Address = 16.20.255.255

   UDP Source Port = 138,   UDP Destination Port = 138

   UDP Header and Datagram Length = 197 = ^x00C5,   Checksum = ^x0E77

   5DA81410   8F6C1120   00000065   D9000045    0000    E...awe.....l....]

            | 0E77C500   8A008A00 | FFFF1410    0010    ..........w.

--------------------------------------------------------------------------------

The only difference between the utilities is the Packet header line, primarily

the utility identifier and the packet sequence formats.

There appear to be 2 formats for packet sequencing

Format 1:

 ... packet nn at DD-MMM-YYYY hh:mm:ss.ss

Format 2:

 ... packet seq # = nn at DD-MMM-YYYY hh:mm:ss.ss

If there are other formats then code will have to be written in parse_vms_packet()

to handle them.

--------------------------------------------------------------------------------

 */

/* Magic text to check for VMS-ness of file using possible utility names

 *

 */

#define VMS_HDR_MAGIC_STR1      "TCPIPtrace"

#define VMS_HDR_MAGIC_STR2      "TCPtrace"

#define VMS_HDR_MAGIC_STR3      "INTERnet trace"

/* Magic text for start of packet */

#define VMS_REC_MAGIC_STR1      VMS_HDR_MAGIC_STR1

#define VMS_REC_MAGIC_STR2      VMS_HDR_MAGIC_STR2

#define VMS_REC_MAGIC_STR3      VMS_HDR_MAGIC_STR3

#define VMS_HEADER_LINES_TO_CHECK    200

#define VMS_LINE_LENGTH              240

static bool vms_read(wtap *wth, wtap_rec *rec, int *err,

    char **err_info, int64_t *data_offset);

static bool vms_seek_read(wtap *wth, int64_t seek_off, wtap_rec *rec,

    int *err, char **err_info);

static bool parse_single_hex_dump_line(char* rec, Buffer *buf,

    int in_off, int remaining_bytes);

static bool parse_vms_packet(wtap *wth, FILE_T fh, wtap_rec *rec, int *err,

    char **err_info);

static int vms_file_type_subtype = -1;

void register_vms(void);

#ifdef TCPIPTRACE_FRAGMENTS_HAVE_HEADER_LINE

/* Seeks to the beginning of the next packet, and returns the

   byte offset.  Returns -1 on failure, and sets "*err" to the error

   and sets "*err_info" to null or an additional error string. */

static long vms_seek_next_packet(wtap *wth, int *err, char **err_info)

{

    long cur_off;

    char buf[VMS_LINE_LENGTH];

    while (1) {

        cur_off = file_tell(wth->fh);

        if (cur_off == -1) {

            /* Error */

            *err = file_error(wth->fh, err_info);

            return -1;

        }

        if (file_gets(buf, sizeof(buf), wth->fh) == NULL) {

            /* EOF or error. */

            *err = file_error(wth->fh, err_info);

            break;

        }

        if (strstr(buf, VMS_REC_MAGIC_STR1) ||

            strstr(buf, VMS_REC_MAGIC_STR2) ||

            strstr(buf, VMS_REC_MAGIC_STR2)) {

            (void) g_strlcpy(hdr, buf,VMS_LINE_LENGTH);

            return cur_off;

        }

    }

    return -1;

}

#endif /* TCPIPTRACE_FRAGMENTS_HAVE_HEADER_LINE */

/* Look through the first part of a file to see if this is

 * a VMS trace file.

 *

 * Returns true if it is, false if it isn't or if we get an I/O error;

 * if we get an I/O error, "*err" will be set to a non-zero value and

 * "*err_info will be set to null or an additional error string.

 *

 * Leaves file handle at beginning of line that contains the VMS Magic

 * identifier.

 */

static bool vms_check_file_type(wtap *wth, int *err, char **err_info)

{

    char buf[VMS_LINE_LENGTH];

    unsigned reclen, line;

    int64_t mpos;

    buf[VMS_LINE_LENGTH-1] = '\0';

    for (line = 0; line < VMS_HEADER_LINES_TO_CHECK; line++) {

        mpos = file_tell(wth->fh);

        if (mpos == -1) {

            /* Error. */

            *err = file_error(wth->fh, err_info);

            return false;

        }

        if (file_gets(buf, VMS_LINE_LENGTH, wth->fh) == NULL) {

            /* EOF or error. */

            *err = file_error(wth->fh, err_info);

            return false;

        }

        reclen = (unsigned) strlen(buf);

        if (reclen < strlen(VMS_HDR_MAGIC_STR1) ||

            reclen < strlen(VMS_HDR_MAGIC_STR2) ||

            reclen < strlen(VMS_HDR_MAGIC_STR3)) {

            continue;

        }

        if (strstr(buf, VMS_HDR_MAGIC_STR1) ||

            strstr(buf, VMS_HDR_MAGIC_STR2) ||

            strstr(buf, VMS_HDR_MAGIC_STR3)) {

            /* Go back to the beginning of this line, so we will

             * re-read it. */

            if (file_seek(wth->fh, mpos, SEEK_SET, err) == -1) {

                /* Error. */

                return false;

            }

            return true;

        }

    }

    *err = 0;

    return false;

}

wtap_open_return_val vms_open(wtap *wth, int *err, char **err_info)

{

    /* Look for VMS header */

    if (!vms_check_file_type(wth, err, err_info)) {

        if (*err != 0 && *err != WTAP_ERR_SHORT_READ)

            return WTAP_OPEN_ERROR;

        return WTAP_OPEN_NOT_MINE;

    }

    wth->file_encap = WTAP_ENCAP_RAW_IP;

    wth->file_type_subtype = vms_file_type_subtype;

    wth->snapshot_length = 0; /* not known */

    wth->subtype_read = vms_read;

    wth->subtype_seek_read = vms_seek_read;

    wth->file_tsprec = WTAP_TSPREC_10_MSEC;

    /*

     * Add an IDB; we don't know how many interfaces were

     * involved, so we just say one interface, about which

     * we only know the link-layer type, snapshot length,

     * and time stamp resolution.

     */

    wtap_add_generated_idb(wth);

    return WTAP_OPEN_MINE;

}

/* Find the next packet and parse it; called from wtap_read(). */

static bool vms_read(wtap *wth, wtap_rec *rec, int *err,

    char **err_info, int64_t *data_offset)

{

    int64_t  offset = 0;

    /* Find the next packet */

#ifdef TCPIPTRACE_FRAGMENTS_HAVE_HEADER_LINE

    offset = vms_seek_next_packet(wth, err, err_info);

#else

    offset = file_tell(wth->fh);

#endif

    if (offset < 1) {

        *err = file_error(wth->fh, err_info);

        return false;

    }

    *data_offset = offset;

    /* Parse the packet */

    return parse_vms_packet(wth, wth->fh, rec, err, err_info);

}

/* Used to read packets in random-access fashion */

static bool vms_seek_read(wtap *wth, int64_t seek_off, wtap_rec *rec,

    int *err, char **err_info)

{

    if (file_seek(wth->random_fh, seek_off - 1, SEEK_SET, err) == -1)

        return false;

    if (!parse_vms_packet(wth, wth->random_fh, rec, err, err_info)) {

        if (*err == 0)

            *err = WTAP_ERR_SHORT_READ;

        return false;

    }

    return true;

}

/* isdumpline assumes that dump lines start with some non-alphanumerics

 * followed by 4 hex numbers - each 8 digits long, each hex number followed

 * by 3 spaces.

 */

static int

isdumpline( char *line )

{

    int i, j;

    while (*line && !g_ascii_isalnum(*line))

        line++;

    for (j=0; j<4; j++) {

        for (i=0; i<8; i++, line++)

            if (! g_ascii_isxdigit(*line))

                return false;

        for (i=0; i<3; i++, line++)

            if (*line != ' ')

                return false;

    }

    return g_ascii_isspace(*line);

}

/* Parses a packet record. */

static bool

parse_vms_packet(wtap *wth, FILE_T fh, wtap_rec *rec, int *err, char **err_info)

{

    char    line[VMS_LINE_LENGTH + 1];

    int     num_items_scanned;

    bool have_pkt_len = false;

    uint32_t pkt_len = 0;

    int     pktnum;

    int     csec = 101;

    struct tm tm;

    char mon[4] = {'J', 'A', 'N', 0};

    char   *p;

    const char *endp;

    static const char months[] = "JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC";

    uint32_t i;

    int     offset = 0;

    tm.tm_year = 1970;

    tm.tm_mon = 0;

    tm.tm_mday = 1;

    tm.tm_hour = 1;

    tm.tm_min = 1;

    tm.tm_sec = 1;

    /* Skip lines until one starts with a hex number */

    do {

        if (file_gets(line, VMS_LINE_LENGTH, fh) == NULL) {

            *err = file_error(fh, err_info);

            if ((*err == 0) && (csec != 101)) {

                *err = WTAP_ERR_SHORT_READ;

            }

            return false;

        }

        line[VMS_LINE_LENGTH] = '\0';

        if ((csec == 101) && (p = strstr(line, "packet ")) != NULL

            && (! strstr(line, "could not save "))) {

            /* Find text in line starting with "packet ". */

            /* First look for the Format 1 type sequencing */

            num_items_scanned = sscanf(p,

                                       "packet %9d at %2d-%3s-%4d %2d:%2d:%2d.%9d",

                                       &pktnum, &tm.tm_mday, mon,

                                       &tm.tm_year, &tm.tm_hour,

                                       &tm.tm_min, &tm.tm_sec, &csec);

            /* Next look for the Format 2 type sequencing */

            if (num_items_scanned != 8) {

              num_items_scanned = sscanf(p,

                                         "packet seq # = %9d at %2d-%3s-%4d %2d:%2d:%2d.%9d",

                                         &pktnum, &tm.tm_mday, mon,

                                         &tm.tm_year, &tm.tm_hour,

                                         &tm.tm_min, &tm.tm_sec, &csec);

            }

            /* if unknown format then exit with error        */

            /* We will need to add code to handle new format */

            if (num_items_scanned != 8) {

                *err = WTAP_ERR_BAD_FILE;

                *err_info = g_strdup("vms: header line not valid");

                return false;

            }

        }

        if ( (! have_pkt_len) && (p = strstr(line, "Length "))) {

            p += sizeof("Length ");

            while (*p && ! g_ascii_isdigit(*p))

                p++;

            if ( !*p ) {

                *err = WTAP_ERR_BAD_FILE;

                *err_info = g_strdup("vms: Length field not valid");

                return false;

            }

            if (!ws_strtou32(p, &endp, &pkt_len) || (*endp != '\0' && !g_ascii_isspace(*endp))) {

                *err = WTAP_ERR_BAD_FILE;

                *err_info = ws_strdup_printf("vms: Length field '%s' not valid", p);

                return false;

            }

            have_pkt_len = true;

            break;

        }

    } while (! isdumpline(line));

    if (! have_pkt_len) {

        *err = WTAP_ERR_BAD_FILE;

        *err_info = ws_strdup_printf("vms: Length field not found");

        return false;

    }

    if (pkt_len > WTAP_MAX_PACKET_SIZE_STANDARD) {

        /*

         * Probably a corrupt capture file; return an error,

         * so that our caller doesn't blow up trying to allocate

         * space for an immensely-large packet.

         */

        *err = WTAP_ERR_BAD_FILE;

        *err_info = ws_strdup_printf("vms: File has %u-byte packet, bigger than maximum of %u",

                                    pkt_len, WTAP_MAX_PACKET_SIZE_STANDARD);

        return false;

    }

    p = strstr(months, mon);

    if (p)

        tm.tm_mon = (int) (p - months) / 3;

    tm.tm_year -= 1900;

    tm.tm_isdst = -1;

    wtap_setup_packet_rec(rec, wth->file_encap);

    rec->block = wtap_block_create(WTAP_BLOCK_PACKET);

    rec->presence_flags = WTAP_HAS_TS;

    rec->ts.secs = mktime(&tm);

    rec->ts.nsecs = csec * 10000000;

    rec->rec_header.packet_header.caplen = pkt_len;

    rec->rec_header.packet_header.len = pkt_len;

    /* Make sure we have enough room for the packet */

    ws_buffer_assure_space(&rec->data, pkt_len);

    /* Convert the ASCII hex dump to binary data */

    for (i = 0; i < pkt_len; i += 16) {

        if (file_gets(line, VMS_LINE_LENGTH, fh) == NULL) {

            *err = file_error(fh, err_info);

            if (*err == 0) {

                *err = WTAP_ERR_SHORT_READ;

            }

            return false;

        }

        line[VMS_LINE_LENGTH] = '\0';

        if (i == 0) {

            while (! isdumpline(line)) { /* advance to start of hex data */

                if (file_gets(line, VMS_LINE_LENGTH, fh) == NULL) {

                    *err = file_error(fh, err_info);

                    if (*err == 0) {

                        *err = WTAP_ERR_SHORT_READ;

                    }

                    return false;

                }

                line[VMS_LINE_LENGTH] = '\0';

            }

            while (line[offset] && !g_ascii_isxdigit(line[offset]))

                offset++;

        }

        if (!parse_single_hex_dump_line(line, &rec->data,

                                        offset, pkt_len - i)) {

            *err = WTAP_ERR_BAD_FILE;

            *err_info = g_strdup("vms: hex dump not valid");

            return false;

        }

    }

    /* Avoid TCPIPTRACE-W-BUFFERSFUL, TCPIPtrace could not save n packets.

     * errors.

     *

     * XXX - when we support packet drop report information in the

     * Wiretap API, we should parse those lines and return "n" as

     * a packet drop count. */

    if (!file_gets(line, VMS_LINE_LENGTH, fh)) {

        *err = file_error(fh, err_info);

        if (*err == 0) {

            /* There is no next line, so there's no "TCPIPtrace could not

             * save n packets" line; not an error. */

            return true;

        }

        return false;

    }

    return true;

}

/*

          1         2         3         4

0123456789012345678901234567890123456789012345

   50010C0A   A34C0640   00009017   2C000045    0000    E..,....@.L....P

   00000000   14945E52   0A00DC02 | 32010C0A    0010    ...2....R^......

       0000 | B4050402   00003496   00020260    0020    `....4........

*/

#define START_POS    7

#define HEX_LENGTH    ((8 * 4) + 7) /* eight clumps of 4 bytes with 7 inner spaces */

/* Take a string representing one line from a hex dump and converts the

 * text to binary data. We check the printed offset with the offset

 * we are passed to validate the record. We place the bytes in the buffer

 * at the specified offset.

 *

 * Returns true if good hex dump, false if bad.

 */

static bool

parse_single_hex_dump_line(char* rec, Buffer *buf, int in_off,

                           int remaining_bytes) {

    int        i;

    char        *s;

    unsigned long value;

    static const int offsets[16] = {39,37,35,33,28,26,24,22,17,15,13,11,6,4,2,0};

    char lbuf[3] = {0,0,0};

    uint8_t *pd;

    /* Get the byte_offset directly from the record */

    s = rec;

    value = strtoul(s + 45 + in_off, NULL, 16);    /* XXX - error check? */

    if (value != ws_buffer_length(buf)) {

        return false;

    }

    if (remaining_bytes > 16)

        remaining_bytes = 16;

    /* Read the octets right to left, as that is how they are displayed

     * in VMS.

     */

    pd = ws_buffer_end_ptr(buf);

    for (i = 0; i < remaining_bytes; i++) {

        lbuf[0] = rec[offsets[i] + in_off];

        lbuf[1] = rec[offsets[i] + 1 + in_off];

        pd[i] = (uint8_t) strtoul(lbuf, NULL, 16);

    }

    ws_buffer_increase_length(buf, remaining_bytes);

    return true;

}

static const struct supported_block_type vms_blocks_supported[] = {

    /*

     * We support packet blocks, with no comments or other options.

     */

    { WTAP_BLOCK_PACKET, MULTIPLE_BLOCKS_SUPPORTED, NO_OPTIONS_SUPPORTED }

};

static const struct file_type_subtype_info vms_info = {

    "TCPIPtrace (VMS)", "tcpiptrace", "txt", NULL,

    false, BLOCKS_SUPPORTED(vms_blocks_supported),

    NULL, NULL, NULL

};

void register_vms(void)

{

    vms_file_type_subtype = wtap_register_file_type_subtype(&vms_info);

    /*

     * Register name for backwards compatibility with the

     * wtap_filetypes table in Lua.

     */

    wtap_register_backwards_compatibility_lua_name("VMS",

                                                   vms_file_type_subtype);

}

/*

 * 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=true:

 */