smsc_cimd2.c

The Kannel Open Source WAP and SMS gateway works as both an SMS gateway, for implementing keyword b

                                dlen - negative, gw_isdigit)) {
            warning(0, "CIMD2[%s]: packet has '%s' parameter with non-integer contents", 
                    octstr_get_cstr(conn->id),
                    parameters[i].name);
            errors++;
        }
        if (octstr_parse_long(&value, data, dpos, 10) >= 0 &&
            (value < parameters[i].minval || value > parameters[i].maxval)) {
            warning(0, "CIMD2[%s]: packet has '%s' parameter out of range (value %ld, min %d, max %d)",
                    octstr_get_cstr(conn->id),
                    parameters[i].name, value,
                    parameters[i].minval, parameters[i].maxval);
            errors++;
        }
        break;
    case P_TIME:
        if (!octstr_check_range(data, dpos, dlen, gw_isdigit)) {
            warning(0, "CIMD2[%s]: packet has '%s' parameter with non-digit contents", 
                    octstr_get_cstr(conn->id),
                    parameters[i].name);
            errors++;
        }
        break;
    case P_ADDRESS:
        if (!octstr_check_range(data, dpos, dlen, isphonedigit)) {
            warning(0, "CIMD2[%s]: packet has '%s' parameter with non phone number contents", 
                    octstr_get_cstr(conn->id),
                    parameters[i].name);
            errors++;
        }
        break;
    case P_HEX:
        if (!octstr_check_range(data, dpos, dlen, gw_isxdigit)) {
            warning(0, "CIMD2[%s]: packet has '%s' parameter with non-hex contents", 
                    octstr_get_cstr(conn->id),
                    parameters[i].name);
            errors++;
        }
        if (dlen % 2 != 0) {
            warning(0, "CIMD2[%s]: packet has odd-length '%s' parameter", 
                    octstr_get_cstr(conn->id),
                    parameters[i].name);
            errors++;
        }
        break;
    case P_SMS:
    case P_STRING:  /* nothing to check */
        break;
    }

    if (errors > 0)
        return -1;
    return 0;
}


/* Check the packet against the CIMD 2 spec, generating log entries as
 * necessary. Return -1 if anything was wrong, otherwise 0. */
/* TODO: Check if parameters found actually belong in the packet type */
static int packet_check(struct packet *packet, SMSCConn *conn)
{
    int errors = 0;
    long pos, len, next;
    Octstr *data;

    gw_assert(packet != NULL);
    data = packet->data;

    if (octstr_search_char(data, 0, 0) >= 0) {
        /* CIMD2 spec does not allow NUL bytes in a packet */
        warning(0, "CIMD2[%s]: packet contains NULs",
                octstr_get_cstr(conn->id));
        errors++;
    }

    /* Assume the packet starts with STX and ends with ETX,
     * because we parsed it that way in the first place. */

    errors += (packet_check_header(packet,conn) < 0);

    /* Parameters are separated by tabs.  After the last parameter
     * there is a tab, an optional two-digit checksum, and the ETX.
     * Check each parameter in turn, by skipping from tab to tab.
     */
    len = octstr_len(data);
    /* Start at the first tab, wherever it is, so that we can still
     * check parameters if the header was weird. */
    pos = octstr_search_char(data, TAB, 0);
    for ( ; pos >= 0; pos = next) {
        next = octstr_search_char(data, TAB, pos + 1);
        if (next >= 0) {
            errors += (packet_check_parameter(packet, pos, next - pos, conn) < 0);
        } else {
            /* Check if the checksum has the right format.  Don't
             * check the sum itself here, that will be done in a
             * separate call later. */
            /* There are two valid formats: TAB ETX (no checksum)
             * and TAB digit digit ETX.  We already know the TAB
             * and the ETX are there. */
            if (!(octstr_len(data) - pos == 2 ||
                  (octstr_len(data) - pos == 4 &&
                   octstr_check_range(data, pos + 1, 2, gw_isxdigit)))) {
                warning(0, "CIMD2[%s]: packet checksum in wrong format",
                        octstr_get_cstr(conn->id));
                errors++;
            }
        }
    }


    if (errors > 0) {
        octstr_dump(packet->data, 0);
        return -1;
    }

    return 0;
}

static void packet_check_can_receive(struct packet *packet, SMSCConn *conn)
{
    gw_assert(packet != NULL);

    if (!operation_can_receive(packet->operation)) {
        Octstr *name = operation_name(packet->operation);
        warning(0, "CIMD2[%s]: SMSC sent us %s request",
                octstr_get_cstr(conn->id),
                octstr_get_cstr(name));
        octstr_destroy(name);
    }
}

/* Table of known error codes */
static struct
{
    int code;
    unsigned char *text;
}
cimd2_errors[] = {
    { 0, "No error" },
    { 1, "Unexpected operation" },
    { 2, "Syntax error" },
    { 3, "Unsupported parameter error" },
    { 4, "Connection to message center lost" },
    { 5, "No response from message center" },
    { 6, "General system error" },
    { 7, "Cannot find information" },
    { 8, "Parameter formatting error" },
    { 9, "Requested operation failed" },
    /* LOGIN error codes */
    { 100, "Invalid login" },
    { 101, "Incorrect access type" },
    { 102, "Too many users with this login id" },
    { 103, "Login refused by message center" },
    /* SUBMIT MESSAGE error codes */
    { 300, "Incorrect destination address" },
    { 301, "Incorrect number of destination addresses" },
    { 302, "Syntax error in user data parameter" },
    { 303, "Incorrect bin/head/normal user data parameter combination" },
    { 304, "Incorrect data coding scheme parameter usage" },
    { 305, "Incorrect validity period parameters usage" },
    { 306, "Incorrect originator address usage" },
    { 307, "Incorrect pid paramterer usage" },
    { 308, "Incorrect first delivery parameter usage" },
    { 309, "Incorrect reply path usage" },
    { 310, "Incorrect status report request parameter usage" },
    { 311, "Incorrect cancel enabled parameter usage" },
    { 312, "Incorrect priority parameter usage" },
    { 313, "Incorrect tariff class parameter usage" },
    { 314, "Incorrect service description parameter usage" },
    { 315, "Incorrect transport type parameter usage" },
    { 316, "Incorrect message type parameter usage" },
    { 318, "Incorrect mms parameter usage" },
    { 319, "Incorrect operation timer parameter usage" },
    /* ENQUIRE MESSAGE STATUS error codes */
    { 400, "Incorrect address parameter usage" },
    { 401, "Incorrect scts parameter usage" },
    /* DELIVERY REQUEST error codes */
    { 500, "Incorrect scts parameter usage" },
    { 501, "Incorrect mode parameter usage" },
    { 502, "Incorrect parameter combination" },
    /* CANCEL MESSAGE error codes */
    { 600, "Incorrect scts parameter usage" },
    { 601, "Incorrect address parameter usage" },
    { 602, "Incorrect mode parameter usage" },
    { 603, "Incorrect parameter combination" },
    /* SET error codes */
    { 800, "Changing password failed" },
    { 801, "Changing password not allowed" },
    /* GET error codes */
    { 900, "Unsupported item requested" },
    { -1, NULL }
};

static int packet_display_error(struct packet *packet, SMSCConn *conn)
{
    int code;
    Octstr *text = NULL;
    Octstr *opname = NULL;

    code = packet_get_int_parm(packet, P_ERROR_CODE);
    text = packet_get_string_parm(packet, P_ERROR_TEXT);

    if (code <= 0) {
        octstr_destroy(text);
        return 0;
    }

    if (text == NULL) {
        /* No error text.  Try to find it in the table. */
        int i;
        for (i = 0; cimd2_errors[i].text != NULL; i++) {
            if (cimd2_errors[i].code == code) {
                text = octstr_create(cimd2_errors[i].text);
                break;
            }
        }
    }

    if (text == NULL) {
        /* Still no error text.  Make one up. */
        text = octstr_create("Unknown error");
    }

    opname = operation_name(packet->operation);
    error(0, "CIMD2[%s]: %s contained error message:",
          octstr_get_cstr(conn->id),
          octstr_get_cstr(opname));
    error(0, "code %03d: %s", code, octstr_get_cstr(text));
    octstr_destroy(opname);
    octstr_destroy(text);
    return code;
}

/* Table of special combinations, for convert_gsm_to_latin1. */
/* Each cimd1, cimd2 pair is mapped to a character in the GSM default
 * character set. */
static const struct
{
    unsigned char cimd1, cimd2;
    unsigned char gsm;
}
cimd_combinations[] = {
    { 'O', 'a', 0 },     /* @ */
    { 'L', '-', 1 },     /* Pounds sterling */
    { 'Y', '-', 3 },     /* Yen */
    { 'e', '`', 4 },     /* egrave */
    { 'e', '\'', 5 },    /* eacute */
    { 'u', '`', 6 },     /* ugrave */
    { 'i', '`', 7 },     /* igrave */
    { 'o', '`', 8 },     /* ograve */
    { 'C', ',', 9 },     /* C cedilla */
    { 'O', '/', 11 },    /* Oslash */
    { 'o', '/', 12 },    /* oslash */
    { 'A', '*', 14 },    /* Aring */
    { 'a', '*', 15 },    /* aring */
    { 'g', 'd', 16 },    /* greek delta */
    { '-', '-', 17 },    /* underscore */
    { 'g', 'f', 18 },    /* greek phi */
    { 'g', 'g', 19 },    /* greek gamma */
    { 'g', 'l', 20 },    /* greek lambda */
    { 'g', 'o', 21 },    /* greek omega */
    { 'g', 'p', 22 },    /* greek pi */
    { 'g', 'i', 23 },    /* greek psi */
    { 'g', 's', 24 },    /* greek sigma */
    { 'g', 't', 25 },    /* greek theta */
    { 'g', 'x', 26 },    /* greek xi */
    { 'X', 'X', 27 },    /* escape */
    { 'A', 'E', 28 },    /* AE ligature */
    { 'a', 'e', 29 },    /* ae ligature */
    { 's', 's', 30 },    /* german double s */
    { 'E', '\'', 31 },   /* Eacute */
    { 'q', 'q', '"' },
    { 'o', 'x', 36 },    /* international currency symbol */
    { '!', '!', 64 },    /* inverted ! */
    { 'A', '"', 91 },    /* Adieresis */
    { 'O', '"', 92 },    /* Odieresis */
    { 'N', '~', 93 },    /* N tilde */
    { 'U', '"', 94 },    /* Udieresis */
    { 's', 'o', 95 },    /* section mark */
    { '?', '?', 96 },    /* inverted ? */
    { 'a', '"', 123 },   /* adieresis */
    { 'o', '"', 124 },   /* odieresis */
    { 'n', '~', 125 },   /* n tilde */
    { 'u', '"', 126 },   /* udieresis */
    { 'a', '`', 127 },   /* agrave */
    { 0, 0, 0 }
};


/* Convert text in the CIMD2 User Data format to the GSM default
 * character set.
 * CIMD2 allows 8-bit characters in this format; they map directly
 * to the corresponding ISO-8859-1 characters.  Since we are heading
 * toward that character set in the end, we don't bother converting
 * those to GSM. */
static void convert_cimd2_to_gsm(Octstr *text, SMSCConn *conn)
{
    long pos, len;
    int cimd1, cimd2;
    int c;
    int i;

    /* CIMD2 uses four single-character mappings that do not map
     * to themselves:
     * '@' from 64 to 0, '$' from 36 to 2, ']' from 93 to 14 (A-ring),
     * and '}' from 125 to 15 (a-ring).
     * Other than those, we only have to worry about the escape
     * sequences introduced by _ (underscore).
     */

    len = octstr_len(text);
    for (pos = 0; pos < len; pos++) {
        c = octstr_get_char(text, pos);
        if (c == '@')
            octstr_set_char(text, pos, 0);
        else if (c == '$')
            octstr_set_char(text, pos, 2);
        else if (c == ']')
            octstr_set_char(text, pos, 14);
        else if (c == '}')
            octstr_set_char(text, pos, 15);
        else if (c == '_' && pos + 2 < len) {
            cimd1 = octstr_get_char(text, pos + 1);
            cimd2 = octstr_get_char(text, pos + 2);
            for (i = 0; cimd_combinations[i].cimd1 != 0; i++) {
                if (cimd_combinations[i].cimd1 == cimd1 &&
                    cimd_combinations[i].cimd2 == cimd2)
                    break;
            }
            if (cimd_combinations[i].cimd1 == 0)
                warning(0, "CIMD2[%s]: Encountered unknown "
                        "escape code _%c%c, ignoring.",
                        octstr_get_cstr(conn->id),
                        cimd1, cimd2);
            else {
                octstr_delete(text, pos, 2);
                octstr_set_char(text, pos, cimd_combinations[i].gsm);
                len = octstr_len(text);
            }
        }
    }
}


/* Convert text in the GSM default character set to the CIMD2 User Data
 * format, which is a representation of the GSM default character set
 * in the lower 7 bits of ISO-8859-1.  (8-bit characters are also
 * allowed, but it's just as easy not to use them.) */
static void convert_gsm_to_cimd2(Octstr *text)
{
    long pos, len;

    len = octstr_len(text);
    for (pos = 0; pos < len; pos++) {
        int c, i;

        c = octstr_get_char(text, pos);
        /* If c is not in the GSM alphabet at this point,
         * the caller did something badly wrong. */
        gw_assert(c >= 0);
        gw_assert(c < 128);

        for (i = 0; cimd_combinations[i].cimd1 != 0; i++) {
            if (cimd_combinations[i].gsm == c)
                break;
        }

        if (cimd_combinations[i].gsm == c) {
            /* Escape sequence */
            octstr_insert_data(text, pos, "_ ", 2);
            pos += 2;
            len += 2;
            octstr_set_char(text, pos - 1, cimd_combinations[i].cimd1);
            octstr_set_char(text, pos, cimd_combinations[i].cimd2);
        } else if (c == 2) {
            /* The dollar sign is the only GSM character that
            	 * does not have a CIMD escape sequence and does not
             * map to itself. */
            octstr_set_char(text, pos, '$');
        }
    }
}


/***************************************************************************/
/* Packet encoding functions.  They do not allow the creation of invalid   */
/* CIMD 2 packets.                                                         */
/***************************************************************************/

/* Build a new packet struct with this operation code and sequence number. */
static struct packet *packet_create(int operation, int seq)
{
    struct packet *packet;