source: protocols/oscar/im.c @ 1d20e4d

/*
 *  aim_im.c
 *
 *  The routines for sending/receiving Instant Messages.
 *
 *  Note the term ICBM (Inter-Client Basic Message) which blankets
 *  all types of genericly routed through-server messages.  Within
 *  the ICBM types (family 4), a channel is defined.  Each channel
 *  represents a different type of message.  Channel 1 is used for
 *  what would commonly be called an "instant message".  Channel 2
 *  is used for negotiating "rendezvous".  These transactions end in
 *  something more complex happening, such as a chat invitation, or
 *  a file transfer.
 *
 *  In addition to the channel, every ICBM contains a cookie.  For
 *  standard IMs, these are only used for error messages.  However,
 *  the more complex rendezvous messages make suitably more complex
 *  use of this field.
 *
 */

#include <aim.h>
#include "im.h"
#include "info.h"

/*
 * Send an ICBM (instant message).  
 *
 *
 * Possible flags:
 *   AIM_IMFLAGS_AWAY  -- Marks the message as an autoresponse
 *   AIM_IMFLAGS_ACK   -- Requests that the server send an ack
 *                        when the message is received (of type 0x0004/0x000c)
 *   AIM_IMFLAGS_OFFLINE--If destination is offline, store it until they are
 *                        online (probably ICQ only).
 *   AIM_IMFLAGS_UNICODE--Instead of ASCII7, the passed message is
 *                        made up of UNICODE duples.  If you set
 *                        this, you'd better be damn sure you know
 *                        what you're doing.
 *   AIM_IMFLAGS_ISO_8859_1 -- The message contains the ASCII8 subset
 *                        known as ISO-8859-1.  
 *
 * Generally, you should use the lowest encoding possible to send
 * your message.  If you only use basic punctuation and the generic
 * Latin alphabet, use ASCII7 (no flags).  If you happen to use non-ASCII7
 * characters, but they are all clearly defined in ISO-8859-1, then 
 * use that.  Keep in mind that not all characters in the PC ASCII8
 * character set are defined in the ISO standard. For those cases (most
 * notably when the (r) symbol is used), you must use the full UNICODE
 * encoding for your message.  In UNICODE mode, _all_ characters must
 * occupy 16bits, including ones that are not special.  (Remember that
 * the first 128 UNICODE symbols are equivelent to ASCII7, however they
 * must be prefixed with a zero high order byte.)
 *
 * I strongly discourage the use of UNICODE mode, mainly because none
 * of the clients I use can parse those messages (and besides that,
 * wchars are difficult and non-portable to handle in most UNIX environments).
 * If you really need to include special characters, use the HTML UNICODE 
 * entities.  These are of the form &#2026; where 2026 is the hex 
 * representation of the UNICODE index (in this case, UNICODE 
 * "Horizontal Ellipsis", or 133 in in ASCII8).
 *
 * Implementation note:  Since this is one of the most-used functions
 * in all of libfaim, it is written with performance in mind.  As such,
 * it is not as clear as it could be in respect to how this message is
 * supposed to be layed out. Most obviously, tlvlists should be used 
 * instead of writing out the bytes manually. 
 *
 * XXX more precise verification that we never send SNACs larger than 8192
 * XXX check SNAC size for multipart
 *
 */
int aim_send_im_ext(aim_session_t *sess, struct aim_sendimext_args *args)
{
        static const guint8 deffeatures[] = {
                0x01, 0x01, 0x01, 0x02
        };
        aim_conn_t *conn;
        int i, msgtlvlen;
        aim_frame_t *fr;
        aim_snacid_t snacid;

        if (!sess || !(conn = aim_conn_findbygroup(sess, 0x0004)))
                return -EINVAL;

        if (!args)
                return -EINVAL;

        if (args->flags & AIM_IMFLAGS_MULTIPART) {
                if (args->mpmsg->numparts <= 0)
                        return -EINVAL;
        } else {
                if (!args->msg || (args->msglen <= 0))
                        return -EINVAL;

                if (args->msglen >= MAXMSGLEN)
                        return -E2BIG;
        }

        /* Painfully calculate the size of the message TLV */
        msgtlvlen = 1 + 1; /* 0501 */

        if (args->flags & AIM_IMFLAGS_CUSTOMFEATURES)
                msgtlvlen += 2 + args->featureslen;
        else
                msgtlvlen += 2 + sizeof(deffeatures);

        if (args->flags & AIM_IMFLAGS_MULTIPART) {
                aim_mpmsg_section_t *sec;

                for (sec = args->mpmsg->parts; sec; sec = sec->next) {
                        msgtlvlen += 2 /* 0101 */ + 2 /* block len */;
                        msgtlvlen += 4 /* charset */ + sec->datalen;
                }

        } else {
                msgtlvlen += 2 /* 0101 */ + 2 /* block len */;
                msgtlvlen += 4 /* charset */ + args->msglen;
        }


        if (!(fr = aim_tx_new(sess, conn, AIM_FRAMETYPE_FLAP, 0x02, msgtlvlen+128)))
                return -ENOMEM;

        /* XXX should be optional */    
        snacid = aim_cachesnac(sess, 0x0004, 0x0006, 0x0000, args->destsn, strlen(args->destsn)+1);
        aim_putsnac(&fr->data, 0x0004, 0x0006, 0x0000, snacid);

        /* 
         * Generate a random message cookie 
         *
         * We could cache these like we do SNAC IDs.  (In fact, it 
         * might be a good idea.)  In the message error functions, 
         * the 8byte message cookie is returned as well as the 
         * SNAC ID.
         *
         */
        for (i = 0; i < 8; i++)
                aimbs_put8(&fr->data, (guint8) rand());

        /*
         * Channel ID
         */
        aimbs_put16(&fr->data, 0x0001);

        /*
         * Destination SN (prepended with byte length)
         */
        aimbs_put8(&fr->data, strlen(args->destsn));
        aimbs_putraw(&fr->data, (guint8 *)args->destsn, strlen(args->destsn));

        /*
         * Message TLV (type 2).
         */
        aimbs_put16(&fr->data, 0x0002);
        aimbs_put16(&fr->data, msgtlvlen);

        /*
         * Features 
         *
         */
        aimbs_put8(&fr->data, 0x05);
        aimbs_put8(&fr->data, 0x01);

        if (args->flags & AIM_IMFLAGS_CUSTOMFEATURES) {
                aimbs_put16(&fr->data, args->featureslen);
                aimbs_putraw(&fr->data, args->features, args->featureslen);
        } else {
                aimbs_put16(&fr->data, sizeof(deffeatures));
                aimbs_putraw(&fr->data, deffeatures, sizeof(deffeatures));
        }

        if (args->flags & AIM_IMFLAGS_MULTIPART) {
                aim_mpmsg_section_t *sec;

                for (sec = args->mpmsg->parts; sec; sec = sec->next) {
                        aimbs_put16(&fr->data, 0x0101);
                        aimbs_put16(&fr->data, sec->datalen + 4);
                        aimbs_put16(&fr->data, sec->charset);
                        aimbs_put16(&fr->data, sec->charsubset);
                        aimbs_putraw(&fr->data, sec->data, sec->datalen);
                }

        } else {

                aimbs_put16(&fr->data, 0x0101);

                /* 
                 * Message block length.
                 */
                aimbs_put16(&fr->data, args->msglen + 0x04);

                /*
                 * Character set.
                 */
                if (args->flags & AIM_IMFLAGS_CUSTOMCHARSET) {

                        aimbs_put16(&fr->data, args->charset);
                        aimbs_put16(&fr->data, args->charsubset);

                } else {
                        if (args->flags & AIM_IMFLAGS_UNICODE)
                                aimbs_put16(&fr->data, 0x0002);
                        else if (args->flags & AIM_IMFLAGS_ISO_8859_1)
                                aimbs_put16(&fr->data, 0x0003);
                        else
                                aimbs_put16(&fr->data, 0x0000);

                        aimbs_put16(&fr->data, 0x0000);
                }

                /*
                 * Message.  Not terminated.
                 */
                aimbs_putraw(&fr->data, (guint8 *)args->msg, args->msglen);
        }

        /*
         * Set the Request Acknowledge flag.  
         */
        if (args->flags & AIM_IMFLAGS_ACK) {
                aimbs_put16(&fr->data, 0x0003);
                aimbs_put16(&fr->data, 0x0000);
        }

        /*
         * Set the Autoresponse flag.
         */
        if (args->flags & AIM_IMFLAGS_AWAY) {
                aimbs_put16(&fr->data, 0x0004);
                aimbs_put16(&fr->data, 0x0000);
        }

        if (args->flags & AIM_IMFLAGS_OFFLINE) {
                aimbs_put16(&fr->data, 0x0006);
                aimbs_put16(&fr->data, 0x0000);
        }

        /*
         * Set the I HAVE A REALLY PURTY ICON flag.
         */
        if (args->flags & AIM_IMFLAGS_HASICON) {
                aimbs_put16(&fr->data, 0x0008);
                aimbs_put16(&fr->data, 0x000c);
                aimbs_put32(&fr->data, args->iconlen);
                aimbs_put16(&fr->data, 0x0001);
                aimbs_put16(&fr->data, args->iconsum);
                aimbs_put32(&fr->data, args->iconstamp);
        }

        /*
         * Set the Buddy Icon Requested flag.
         */
        if (args->flags & AIM_IMFLAGS_BUDDYREQ) {
                aimbs_put16(&fr->data, 0x0009);
                aimbs_put16(&fr->data, 0x0000);
        }

        aim_tx_enqueue(sess, fr);

        if (!(sess->flags & AIM_SESS_FLAGS_DONTTIMEOUTONICBM))
                aim_cleansnacs(sess, 60); /* clean out SNACs over 60sec old */

        return 0;
}

/*
 * Simple wrapper for aim_send_im_ext() 
 *
 * You cannot use aim_send_im if you need the HASICON flag.  You must
 * use aim_send_im_ext directly for that.
 *
 * aim_send_im also cannot be used if you require UNICODE messages, because
 * that requires an explicit message length.  Use aim_send_im_ext().
 *
 */
int aim_send_im(aim_session_t *sess, const char *destsn, guint16 flags, const char *msg)
{
        struct aim_sendimext_args args;

        args.destsn = destsn;
        args.flags = flags;
        args.msg = msg;
        args.msglen = strlen(msg);

        /* Make these don't get set by accident -- they need aim_send_im_ext */
        args.flags &= ~(AIM_IMFLAGS_CUSTOMFEATURES | AIM_IMFLAGS_HASICON | AIM_IMFLAGS_MULTIPART);

        return aim_send_im_ext(sess, &args);
}

/**
 * answers status message requests
 * @param sess the oscar session
 * @param sender the guy whos asking
 * @param cookie message id which we are answering for
 * @param message away message
 * @param state our current away state the way icq requests it (0xE8 for away, 0xE9 occupied, ...)
 * @return 0 if no error
 */
int aim_send_im_ch2_statusmessage(aim_session_t *sess, const char *sender, const guint8 *cookie,
        const char *message, const guint8 state, const guint16 dc)
{
    aim_conn_t *conn;
    aim_frame_t *fr;
    aim_snacid_t snacid;

    if (!sess || !(conn = aim_conn_findbygroup(sess, 0x0004)))
                return -EINVAL;
        
    if (!(fr = aim_tx_new(sess, conn, AIM_FRAMETYPE_FLAP, 0x02, 
                                        10+8+2+1+strlen(sender)+2+0x1d+0x10+9+strlen(message)+1)))
                return -ENOMEM;

    snacid = aim_cachesnac(sess, 0x0004, 0x000b, 0x0000, NULL, 0);
    aim_putsnac(&fr->data, 0x0004, 0x000b, 0x0000, snacid);
    
    aimbs_putraw(&fr->data, cookie, 8);
    
    aimbs_put16(&fr->data, 0x0002); /* channel */
    aimbs_put8(&fr->data, strlen(sender));
    aimbs_putraw(&fr->data, (guint8 *)sender, strlen(sender));

    aimbs_put16(&fr->data, 0x0003); /* reason: channel specific */

    aimbs_putle16(&fr->data, 0x001b); /* length of data SEQ1 */
    aimbs_putle16(&fr->data, 0x0008); /* protocol version */

    aimbs_putle32(&fr->data, 0x0000); /* no plugin -> 16 times 0x00 */ 
    aimbs_putle32(&fr->data, 0x0000); 
    aimbs_putle32(&fr->data, 0x0000); 
    aimbs_putle32(&fr->data, 0x0000);

    aimbs_putle16(&fr->data, 0x0000); /* unknown */
    aimbs_putle32(&fr->data, 0x0003); /* client features */
    aimbs_putle8(&fr->data, 0x00); /* unknown */
    aimbs_putle16(&fr->data, dc); /* Sequence number?  XXX - This should decrement by 1 with each request */
    /* end of SEQ1 */

    aimbs_putle16(&fr->data, 0x000e); /* Length of SEQ2 */
    aimbs_putle16(&fr->data, dc); /* Sequence number? same as above
                                       * XXX - This should decrement by 1 with each request */
    aimbs_putle32(&fr->data, 0x00000000); /* Unknown */
    aimbs_putle32(&fr->data, 0x00000000); /* Unknown */
    aimbs_putle32(&fr->data, 0x00000000); /* Unknown */
    /* end of SEQ2 */

    /* now for the real fun */
    aimbs_putle8(&fr->data, state); /* away state */
    aimbs_putle8(&fr->data, 0x03); /* msg-flag: 03 for states */
    aimbs_putle16(&fr->data, 0x0000); /* status code ? */
    aimbs_putle16(&fr->data, 0x0000); /* priority code */
    aimbs_putle16(&fr->data, strlen(message) + 1); /* message length + termination */
    aimbs_putraw(&fr->data, (guint8 *) message, strlen(message) + 1); /* null terminated string */
    
    aim_tx_enqueue(sess, fr);


    return 0;
}


static int outgoingim(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_bstream_t *bs)
{
        int i, ret = 0;
        aim_rxcallback_t userfunc;
        guint16 channel;
        aim_tlvlist_t *tlvlist;
        char *sn;
        int snlen;
        guint16 icbmflags = 0;
        guint8 flag1 = 0, flag2 = 0;
        char *msg = NULL;
        aim_tlv_t *msgblock;

        /* ICBM Cookie. */
        for (i = 0; i < 8; i++)
                aimbs_get8(bs);

        /* Channel ID */
        channel = aimbs_get16(bs);

        if (channel != 0x01) {
                imcb_error(sess->aux_data, "icbm: ICBM received on unsupported channel.  Ignoring.");
                return 0;
        }

        snlen = aimbs_get8(bs);
        sn = aimbs_getstr(bs, snlen);

        tlvlist = aim_readtlvchain(bs);

        if (aim_gettlv(tlvlist, 0x0003, 1))
                icbmflags |= AIM_IMFLAGS_ACK;
        if (aim_gettlv(tlvlist, 0x0004, 1))
                icbmflags |= AIM_IMFLAGS_AWAY;

        if ((msgblock = aim_gettlv(tlvlist, 0x0002, 1))) {
                aim_bstream_t mbs;
                int featurelen, msglen;

                aim_bstream_init(&mbs, msgblock->value, msgblock->length);

                aimbs_get8(&mbs);
                aimbs_get8(&mbs);
                for (featurelen = aimbs_get16(&mbs); featurelen; featurelen--)
                        aimbs_get8(&mbs);
                aimbs_get8(&mbs);
                aimbs_get8(&mbs);

                msglen = aimbs_get16(&mbs) - 4; /* final block length */

                flag1 = aimbs_get16(&mbs);
                flag2 = aimbs_get16(&mbs);

                msg = aimbs_getstr(&mbs, msglen);
        }

        if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                ret = userfunc(sess, rx, channel, sn, msg, icbmflags, flag1, flag2);

        g_free(sn);
        aim_freetlvchain(&tlvlist);

        return ret;
}

/*
 * Ahh, the joys of nearly ridiculous over-engineering.
 *
 * Not only do AIM ICBM's support multiple channels.  Not only do they
 * support multiple character sets.  But they support multiple character 
 * sets / encodings within the same ICBM.
 *
 * These multipart messages allow for complex space savings techniques, which
 * seem utterly unnecessary by today's standards.  In fact, there is only
 * one client still in popular use that still uses this method: AOL for the
 * Macintosh, Version 5.0.  Obscure, yes, I know.  
 *
 * In modern (non-"legacy") clients, if the user tries to send a character
 * that is not ISO-8859-1 or ASCII, the client will send the entire message
 * as UNICODE, meaning that every character in the message will occupy the
 * full 16 bit UNICODE field, even if the high order byte would be zero.
 * Multipart messages prevent this wasted space by allowing the client to
 * only send the characters in UNICODE that need to be sent that way, and
 * the rest of the message can be sent in whatever the native character 
 * set is (probably ASCII).
 *
 * An important note is that sections will be displayed in the order that
 * they appear in the ICBM.  There is no facility for merging or rearranging
 * sections at run time.  So if you have, say, ASCII then UNICODE then ASCII,
 * you must supply two ASCII sections with a UNICODE in the middle, and incur
 * the associated overhead.
 *
 * Normally I would have laughed and given a firm 'no' to supporting this
 * seldom-used feature, but something is attracting me to it.  In the future,
 * it may be possible to abuse this to send mixed-media messages to other
 * open source clients (like encryption or something) -- see faimtest for
 * examples of how to do this.
 *
 * I would definitly recommend avoiding this feature unless you really
 * know what you are doing, and/or you have something neat to do with it.
 *
 */
int aim_mpmsg_init(aim_session_t *sess, aim_mpmsg_t *mpm)
{

        memset(mpm, 0, sizeof(aim_mpmsg_t));

        return 0;
}

static int mpmsg_addsection(aim_session_t *sess, aim_mpmsg_t *mpm, guint16 charset, guint16 charsubset, guint8 *data, guint16 datalen)
{
        aim_mpmsg_section_t *sec; 
        
        if (!(sec = g_new0(aim_mpmsg_section_t,1)))
                return -1;

        sec->charset = charset;
        sec->charsubset = charsubset;
        sec->data = data;
        sec->datalen = datalen;
        sec->next = NULL;

        if (!mpm->parts)
                mpm->parts = sec;
        else {
                aim_mpmsg_section_t *cur;

                for (cur = mpm->parts; cur->next; cur = cur->next)
                        ;
                cur->next = sec;
        }

        mpm->numparts++;

        return 0;
}

void aim_mpmsg_free(aim_session_t *sess, aim_mpmsg_t *mpm)
{
        aim_mpmsg_section_t *cur;

        for (cur = mpm->parts; cur; ) {
                aim_mpmsg_section_t *tmp;
                
                tmp = cur->next;
                g_free(cur->data);
                g_free(cur);
                cur = tmp;
        }
        
        mpm->numparts = 0;
        mpm->parts = NULL;

        return;
}

/*
 * Start by building the multipart structures, then pick the first 
 * human-readable section and stuff it into args->msg so no one gets
 * suspicious.
 *
 */
static int incomingim_ch1_parsemsgs(aim_session_t *sess, guint8 *data, int len, struct aim_incomingim_ch1_args *args)
{
        static const guint16 charsetpri[] = {
                0x0000, /* ASCII first */
                0x0003, /* then ISO-8859-1 */
                0x0002, /* UNICODE as last resort */
        };
        static const int charsetpricount = 3;
        int i;
        aim_bstream_t mbs;
        aim_mpmsg_section_t *sec;

        aim_bstream_init(&mbs, data, len);

        while (aim_bstream_empty(&mbs)) {
                guint16 msglen, flag1, flag2;
                char *msgbuf;

                aimbs_get8(&mbs); /* 01 */
                aimbs_get8(&mbs); /* 01 */

                /* Message string length, including character set info. */
                msglen = aimbs_get16(&mbs);

                /* Character set info */
                flag1 = aimbs_get16(&mbs);
                flag2 = aimbs_get16(&mbs);

                /* Message. */
                msglen -= 4;

                /*
                 * For now, we don't care what the encoding is.  Just copy
                 * it into a multipart struct and deal with it later. However,
                 * always pad the ending with a NULL.  This makes it easier
                 * to treat ASCII sections as strings.  It won't matter for
                 * UNICODE or binary data, as you should never read past
                 * the specified data length, which will not include the pad.
                 *
                 * XXX There's an API bug here.  For sending, the UNICODE is
                 * given in host byte order (aim_mpmsg_addunicode), but here
                 * the received messages are given in network byte order.
                 *
                 */
                msgbuf = aimbs_getstr(&mbs, msglen);
                mpmsg_addsection(sess, &args->mpmsg, flag1, flag2, (guint8 *)msgbuf, (guint16) msglen);

        } /* while */

        args->icbmflags |= AIM_IMFLAGS_MULTIPART; /* always set */

        /*
         * Clients that support multiparts should never use args->msg, as it
         * will point to an arbitrary section.
         *
         * Here, we attempt to provide clients that do not support multipart
         * messages with something to look at -- hopefully a human-readable
         * string.  But, failing that, a UNICODE message, or nothing at all.
         *
         * Which means that even if args->msg is NULL, it does not mean the
         * message was blank.
         *
         */
        for (i = 0; i < charsetpricount; i++) {
                for (sec = args->mpmsg.parts; sec; sec = sec->next) {

                        if (sec->charset != charsetpri[i])
                                continue;

                        /* Great. We found one.  Fill it in. */
                        args->charset = sec->charset;
                        args->charsubset = sec->charsubset;
                        args->icbmflags |= AIM_IMFLAGS_CUSTOMCHARSET;

                        /* Set up the simple flags */
                        if (args->charset == 0x0000)
                                ; /* ASCII */
                        else if (args->charset == 0x0002)
                                args->icbmflags |= AIM_IMFLAGS_UNICODE;
                        else if (args->charset == 0x0003)
                                args->icbmflags |= AIM_IMFLAGS_ISO_8859_1;
                        else if (args->charset == 0xffff)
                                ; /* no encoding (yeep!) */

                        if (args->charsubset == 0x0000)
                                ; /* standard subencoding? */
                        else if (args->charsubset == 0x000b)
                                args->icbmflags |= AIM_IMFLAGS_SUBENC_MACINTOSH;
                        else if (args->charsubset == 0xffff)
                                ; /* no subencoding */
#if 0
                        /* XXX this isn't really necesary... */ 
                        if (    ((args.flag1 != 0x0000) &&
                                 (args.flag1 != 0x0002) &&
                                 (args.flag1 != 0x0003) &&
                                 (args.flag1 != 0xffff)) ||
                                ((args.flag2 != 0x0000) &&
                                 (args.flag2 != 0x000b) &&
                                 (args.flag2 != 0xffff))) {
                                faimdprintf(sess, 0, "icbm: **warning: encoding flags are being used! {%04x, %04x}\n", args.flag1, args.flag2);
                        }
#endif

                        args->msg = (char *)sec->data;
                        args->msglen = sec->datalen;

                        return 0;
                }
        }

        /* No human-readable sections found.  Oh well. */
        args->charset = args->charsubset = 0xffff;
        args->msg = NULL;
        args->msglen = 0;

        return 0;
}

static int incomingim_ch1(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, guint16 channel, aim_userinfo_t *userinfo, aim_bstream_t *bs, guint8 *cookie)
{
        guint16 type, length;
        aim_rxcallback_t userfunc;
        int ret = 0;
        struct aim_incomingim_ch1_args args;
        int endpos;

        memset(&args, 0, sizeof(args));

        aim_mpmsg_init(sess, &args.mpmsg);

        /*
         * This used to be done using tlvchains.  For performance reasons,
         * I've changed it to process the TLVs in-place.  This avoids lots
         * of per-IM memory allocations.
         */
        while (aim_bstream_empty(bs)) {

                type = aimbs_get16(bs);
                length = aimbs_get16(bs);

                endpos = aim_bstream_curpos(bs) + length;

                if (type == 0x0002) { /* Message Block */

                        /*
                         * This TLV consists of the following:
                         *   - 0501 -- Unknown
                         *   - Features: Don't know how to interpret these
                         *   - 0101 -- Unknown
                         *   - Message
                         *
                         */

                        aimbs_get8(bs); /* 05 */
                        aimbs_get8(bs); /* 01 */

                        args.featureslen = aimbs_get16(bs);
                        /* XXX XXX this is all evil! */
                        args.features = bs->data + bs->offset;
                        aim_bstream_advance(bs, args.featureslen);
                        args.icbmflags |= AIM_IMFLAGS_CUSTOMFEATURES;

                        /*
                         * The rest of the TLV contains one or more message
                         * blocks...
                         */
                        incomingim_ch1_parsemsgs(sess, bs->data + bs->offset /* XXX evil!!! */, length - 2 - 2 - args.featureslen, &args);

                } else if (type == 0x0003) { /* Server Ack Requested */

                        args.icbmflags |= AIM_IMFLAGS_ACK;

                } else if (type == 0x0004) { /* Message is Auto Response */

                        args.icbmflags |= AIM_IMFLAGS_AWAY;

                } else if (type == 0x0006) { /* Message was received offline. */

                        /* XXX not sure if this actually gets sent. */
                        args.icbmflags |= AIM_IMFLAGS_OFFLINE;

                } else if (type == 0x0008) { /* I-HAVE-A-REALLY-PURTY-ICON Flag */

                        args.iconlen = aimbs_get32(bs);
                        aimbs_get16(bs); /* 0x0001 */
                        args.iconsum = aimbs_get16(bs);
                        args.iconstamp = aimbs_get32(bs);

                        /*
                         * This looks to be a client bug.  MacAIM 4.3 will
                         * send this tag, but with all zero values, in the
                         * first message of a conversation. This makes no
                         * sense whatsoever, so I'm going to say its a bug.
                         *
                         * You really shouldn't advertise a zero-length icon
                         * anyway.
                         * 
                         */
                        if (args.iconlen)
                                args.icbmflags |= AIM_IMFLAGS_HASICON;

                } else if (type == 0x0009) {

                        args.icbmflags |= AIM_IMFLAGS_BUDDYREQ;

                } else if (type == 0x0017) {

                        args.extdatalen = length;
                        args.extdata = aimbs_getraw(bs, args.extdatalen);

                } else {
                        // imcb_error(sess->aux_data, "Unknown TLV encountered");
                }

                /*
                 * This is here to protect ourselves from ourselves.  That
                 * is, if something above doesn't completly parse its value
                 * section, or, worse, overparses it, this will set the
                 * stream where it needs to be in order to land on the next
                 * TLV when the loop continues.
                 *
                 */
                aim_bstream_setpos(bs, endpos);
        }


        if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                ret = userfunc(sess, rx, channel, userinfo, &args);

        aim_mpmsg_free(sess, &args.mpmsg);
        g_free(args.extdata);

        return ret;
}


static void incomingim_ch2_chat_free(aim_session_t *sess, struct aim_incomingim_ch2_args *args)
{

        /* XXX aim_chat_roominfo_free() */
        g_free(args->info.chat.roominfo.name);

        return;
}

static void incomingim_ch2_chat(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_userinfo_t *userinfo, struct aim_incomingim_ch2_args *args, aim_bstream_t *servdata)
{

        /*
         * Chat room info.
         */
        if (servdata)
                aim_chat_readroominfo(servdata, &args->info.chat.roominfo);

        args->destructor = (void *)incomingim_ch2_chat_free;

        return;
}

static void incomingim_ch2_icqserverrelay_free(aim_session_t *sess, struct aim_incomingim_ch2_args *args)
{

        g_free((char *)args->info.rtfmsg.rtfmsg);

        return;
}

/*
 * The relationship between AIM_CAPS_ICQSERVERRELAY and AIM_CAPS_ICQRTF is 
 * kind of odd. This sends the client ICQRTF since that is all that I've seen
 * SERVERRELAY used for.
 *
 * Note that this is all little-endian.  Cringe.
 *
 * This cap is used for auto status message replies, too [ft]
 *
 */
static void incomingim_ch2_icqserverrelay(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_userinfo_t *userinfo, struct aim_incomingim_ch2_args *args, aim_bstream_t *servdata)
{
        guint16 hdrlen, msglen, dc;
        guint8 msgtype;
    guint8 *plugin;
    int i = 0, tmp = 0;
    struct im_connection *ic = sess->aux_data;

    /* at the moment we just can deal with requests, not with cancel or accept */
    if (args->status != 0) return;

        hdrlen = aimbs_getle16(servdata);

    aim_bstream_advance(servdata, 0x02); /* protocol version */
    plugin = aimbs_getraw(servdata, 0x10); /* following data is a message or 
                                              something plugin specific */
    /* as there is no plugin handling, just skip the rest */
    aim_bstream_advance(servdata, hdrlen - 0x12);

        hdrlen = aimbs_getle16(servdata);
    dc = aimbs_getle16(servdata); /* save the sequence number */
        aim_bstream_advance(servdata, hdrlen - 0x02);

    /* TODO is it a message or something for a plugin? */
    for (i = 0; i < 0x10; i++) {
        tmp |= plugin[i];
    }

    if (!tmp) { /* message follows */

        msgtype = aimbs_getle8(servdata);
        aimbs_getle8(servdata); /* msgflags */

        aim_bstream_advance(servdata, 0x04); /* status code and priority code */

        msglen = aimbs_getle16(servdata); /* message string length */
        args->info.rtfmsg.rtfmsg = aimbs_getstr(servdata, msglen);

        switch(msgtype) {
            case AIM_MTYPE_PLAIN:

                args->info.rtfmsg.fgcolor = aimbs_getle32(servdata);
                args->info.rtfmsg.bgcolor = aimbs_getle32(servdata);

                hdrlen = aimbs_getle32(servdata);
                aim_bstream_advance(servdata, hdrlen);

                /* XXX This is such a hack. */
                args->reqclass = AIM_CAPS_ICQRTF;
                break;

            case AIM_MTYPE_AUTOAWAY: 
            case AIM_MTYPE_AUTOBUSY:
            case AIM_MTYPE_AUTONA:
            case AIM_MTYPE_AUTODND:
            case AIM_MTYPE_AUTOFFC:
            case 0x9c:  /* ICQ 5 seems to send this */
                aim_send_im_ch2_statusmessage(sess, userinfo->sn, args->cookie,
                        ic->away ? ic->away : "", sess->aim_icq_state, dc);
                break;

        }
    } /* message or plugin specific */

    g_free(plugin);
        args->destructor = (void *)incomingim_ch2_icqserverrelay_free;

        return;
}

typedef void (*ch2_args_destructor_t)(aim_session_t *sess, struct aim_incomingim_ch2_args *args);

static int incomingim_ch2(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, guint16 channel, aim_userinfo_t *userinfo, aim_tlvlist_t *tlvlist, guint8 *cookie)
{
        aim_rxcallback_t userfunc;
        aim_tlv_t *block1, *servdatatlv;
        aim_tlvlist_t *list2;
        struct aim_incomingim_ch2_args args;
        aim_bstream_t bbs, sdbs, *sdbsptr = NULL;
        guint8 *cookie2;
        int ret = 0;

        char clientip1[30] = {""};
        char clientip2[30] = {""};
        char verifiedip[30] = {""};

        memset(&args, 0, sizeof(args));

        /*
         * There's another block of TLVs embedded in the type 5 here. 
         */
        block1 = aim_gettlv(tlvlist, 0x0005, 1);
        aim_bstream_init(&bbs, block1->value, block1->length);

        /*
         * First two bytes represent the status of the connection.
         *
         * 0 is a request, 1 is a deny (?), 2 is an accept
         */ 
        args.status = aimbs_get16(&bbs);

        /*
         * Next comes the cookie.  Should match the ICBM cookie.
         */
        cookie2 = aimbs_getraw(&bbs, 8);
        if (memcmp(cookie, cookie2, 8) != 0) 
                imcb_error(sess->aux_data, "rend: warning cookies don't match!");
        memcpy(args.cookie, cookie2, 8);
        g_free(cookie2);

        /*
         * The next 16bytes are a capability block so we can
         * identify what type of rendezvous this is.
         */
        args.reqclass = aim_getcap(sess, &bbs, 0x10);

        /* 
         * What follows may be TLVs or nothing, depending on the
         * purpose of the message.
         *
         * Ack packets for instance have nothing more to them.
         */
        list2 = aim_readtlvchain(&bbs);

        /*
         * IP address from the perspective of the client.
         */
        if (aim_gettlv(list2, 0x0002, 1)) {
                aim_tlv_t *iptlv;

                iptlv = aim_gettlv(list2, 0x0002, 1);

                g_snprintf(clientip1, sizeof(clientip1), "%d.%d.%d.%d",
                                aimutil_get8(iptlv->value+0),
                                aimutil_get8(iptlv->value+1),
                                aimutil_get8(iptlv->value+2),
                                aimutil_get8(iptlv->value+3));
        }

        /*
         * Secondary IP address from the perspective of the client.
         */
        if (aim_gettlv(list2, 0x0003, 1)) {
                aim_tlv_t *iptlv;

                iptlv = aim_gettlv(list2, 0x0003, 1);

                g_snprintf(clientip2, sizeof(clientip2), "%d.%d.%d.%d",
                                aimutil_get8(iptlv->value+0),
                                aimutil_get8(iptlv->value+1),
                                aimutil_get8(iptlv->value+2),
                                aimutil_get8(iptlv->value+3));
        }

        /*
         * Verified IP address (from the perspective of Oscar).
         *
         * This is added by the server.
         */
        if (aim_gettlv(list2, 0x0004, 1)) {
                aim_tlv_t *iptlv;

                iptlv = aim_gettlv(list2, 0x0004, 1);

                g_snprintf(verifiedip, sizeof(verifiedip), "%d.%d.%d.%d",
                                aimutil_get8(iptlv->value+0),
                                aimutil_get8(iptlv->value+1),
                                aimutil_get8(iptlv->value+2),
                                aimutil_get8(iptlv->value+3));
        }

        /*
         * Port number for something.
         */
        if (aim_gettlv(list2, 0x0005, 1))
                args.port = aim_gettlv16(list2, 0x0005, 1);

        /*
         * Error code.
         */
        if (aim_gettlv(list2, 0x000b, 1))
                args.errorcode = aim_gettlv16(list2, 0x000b, 1);

        /*
         * Invitation message / chat description.
         */
        if (aim_gettlv(list2, 0x000c, 1))
                args.msg = aim_gettlv_str(list2, 0x000c, 1);

        /*
         * Character set.
         */
        if (aim_gettlv(list2, 0x000d, 1))
                args.encoding = aim_gettlv_str(list2, 0x000d, 1);
        
        /*
         * Language.
         */
        if (aim_gettlv(list2, 0x000e, 1))
                args.language = aim_gettlv_str(list2, 0x000e, 1);

        /* Unknown -- two bytes = 0x0001 */
        if (aim_gettlv(list2, 0x000a, 1))
                ;

        /* Unknown -- no value */
        if (aim_gettlv(list2, 0x000f, 1))
                ;

        if (strlen(clientip1))
                args.clientip = (char *)clientip1;
        if (strlen(clientip2))
                args.clientip2 = (char *)clientip2;
        if (strlen(verifiedip))
                args.verifiedip = (char *)verifiedip;

        /*
         * This is must be present in PROPOSALs, but will probably not
         * exist in CANCELs and ACCEPTs.
         *
         * Service Data blocks are module-specific in format.
         */
        if ((servdatatlv = aim_gettlv(list2, 0x2711 /* 10001 */, 1))) {

                aim_bstream_init(&sdbs, servdatatlv->value, servdatatlv->length);
                sdbsptr = &sdbs;
        }

        if (args.reqclass & AIM_CAPS_ICQSERVERRELAY)
                incomingim_ch2_icqserverrelay(sess, mod, rx, snac, userinfo, &args, sdbsptr);
        else if (args.reqclass & AIM_CAPS_CHAT)
                incomingim_ch2_chat(sess, mod, rx, snac, userinfo, &args, sdbsptr);


        if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                ret = userfunc(sess, rx, channel, userinfo, &args);


        if (args.destructor)
                ((ch2_args_destructor_t)args.destructor)(sess, &args);

        g_free((char *)args.msg);
        g_free((char *)args.encoding);
        g_free((char *)args.language);

        aim_freetlvchain(&list2);

        return ret;
}

static int incomingim_ch4(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, guint16 channel, aim_userinfo_t *userinfo, aim_tlvlist_t *tlvlist, guint8 *cookie)
{
        aim_bstream_t meat;
        aim_rxcallback_t userfunc;
        aim_tlv_t *block;
        struct aim_incomingim_ch4_args args;
        int ret = 0;

        /*
         * Make a bstream for the meaty part.  Yum.  Meat.
         */
        if (!(block = aim_gettlv(tlvlist, 0x0005, 1)))
                return -1;
        aim_bstream_init(&meat, block->value, block->length);

        args.uin = aimbs_getle32(&meat);
        args.type = aimbs_getle16(&meat);
        args.msg = (char *)aimbs_getraw(&meat, aimbs_getle16(&meat));

        if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                ret = userfunc(sess, rx, channel, userinfo, &args);

        g_free(args.msg);

        return ret;
}

/*
 * It can easily be said that parsing ICBMs is THE single
 * most difficult thing to do in the in AIM protocol.  In
 * fact, I think I just did say that.
 *
 * Below is the best damned solution I've come up with
 * over the past sixteen months of battling with it. This
 * can parse both away and normal messages from every client
 * I have access to.  Its not fast, its not clean.  But it works.
 *
 */
static int incomingim(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_bstream_t *bs)
{
        int i, ret = 0;
        guint8 cookie[8];
        guint16 channel;
        aim_userinfo_t userinfo;

        memset(&userinfo, 0x00, sizeof(aim_userinfo_t));

        /*
         * Read ICBM Cookie.  And throw away.
         */
        for (i = 0; i < 8; i++)
                cookie[i] = aimbs_get8(bs);

        /*
         * Channel ID.
         *
         * Channel 0x0001 is the message channel.  There are 
         * other channels for things called "rendevous"
         * which represent chat and some of the other new
         * features of AIM2/3/3.5. 
         *
         * Channel 0x0002 is the Rendevous channel, which
         * is where Chat Invitiations and various client-client
         * connection negotiations come from.
         *
         * Channel 0x0004 is used for ICQ authorization, or 
         * possibly any system notice.
         *
         */
        channel = aimbs_get16(bs);

        /*
         * Extract the standard user info block.
         *
         * Note that although this contains TLVs that appear contiguous
         * with the TLVs read below, they are two different pieces.  The
         * userinfo block contains the number of TLVs that contain user
         * information, the rest are not even though there is no seperation.
         * aim_extractuserinfo() returns the number of bytes used by the
         * userinfo tlvs, so you can start reading the rest of them right
         * afterward.  
         *
         * That also means that TLV types can be duplicated between the
         * userinfo block and the rest of the message, however there should
         * never be two TLVs of the same type in one block.
         * 
         */
        aim_extractuserinfo(sess, bs, &userinfo);

        /*
         * From here on, its depends on what channel we're on.
         *
         * Technically all channels have a TLV list have this, however,
         * for the common channel 1 case, in-place parsing is used for
         * performance reasons (less memory allocation).
         */
        if (channel == 1) {

                ret = incomingim_ch1(sess, mod, rx, snac, channel, &userinfo, bs, cookie);

        } else if (channel == 2) {
                aim_tlvlist_t *tlvlist;

                /*
                 * Read block of TLVs (not including the userinfo data).  All 
                 * further data is derived from what is parsed here.
                 */
                tlvlist = aim_readtlvchain(bs);

                ret = incomingim_ch2(sess, mod, rx, snac, channel, &userinfo, tlvlist, cookie);

                aim_freetlvchain(&tlvlist);

        } else if (channel == 4) {
                aim_tlvlist_t *tlvlist;

                tlvlist = aim_readtlvchain(bs);
                ret = incomingim_ch4(sess, mod, rx, snac, channel, &userinfo, tlvlist, cookie);
                aim_freetlvchain(&tlvlist);

        } else {

                imcb_error(sess->aux_data, "ICBM received on an unsupported channel.  Ignoring.");

                return 0;
        }

        return ret;
}

/*
 * aim_reqicbmparaminfo()
 *
 * Request ICBM parameter information.
 *
 */
int aim_reqicbmparams(aim_session_t *sess)
{
        aim_conn_t *conn;

        if (!sess || !(conn = aim_conn_findbygroup(sess, 0x0004)))
                return -EINVAL;

        return aim_genericreq_n(sess, conn, 0x0004, 0x0004);
}

/*
 *
 * I definitly recommend sending this.  If you don't, you'll be stuck
 * with the rather unreasonable defaults.  You don't want those.  Send this.
 * 
 */
int aim_seticbmparam(aim_session_t *sess, struct aim_icbmparameters *params)
{
        aim_conn_t *conn;
        aim_frame_t *fr;
        aim_snacid_t snacid;

        if (!sess || !(conn = aim_conn_findbygroup(sess, 0x0004)))
                return -EINVAL;

        if (!params)
                return -EINVAL;

        if (!(fr = aim_tx_new(sess, conn, AIM_FRAMETYPE_FLAP, 0x02, 10+16)))
                return -ENOMEM;

        snacid = aim_cachesnac(sess, 0x0004, 0x0002, 0x0000, NULL, 0);
        aim_putsnac(&fr->data, 0x0004, 0x0002, 0x0000, snacid);

        /* This is read-only (see Parameter Reply). Must be set to zero here. */
        aimbs_put16(&fr->data, 0x0000);

        /* These are all read-write */
        aimbs_put32(&fr->data, params->flags); 
        aimbs_put16(&fr->data, params->maxmsglen);
        aimbs_put16(&fr->data, params->maxsenderwarn); 
        aimbs_put16(&fr->data, params->maxrecverwarn); 
        aimbs_put32(&fr->data, params->minmsginterval);

        aim_tx_enqueue(sess, fr);

        return 0;
}

static int paraminfo(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_bstream_t *bs)
{
        struct aim_icbmparameters params;
        aim_rxcallback_t userfunc;

        params.maxchan = aimbs_get16(bs);
        params.flags = aimbs_get32(bs);
        params.maxmsglen = aimbs_get16(bs);
        params.maxsenderwarn = aimbs_get16(bs);
        params.maxrecverwarn = aimbs_get16(bs);
        params.minmsginterval = aimbs_get32(bs);
        
        if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                return userfunc(sess, rx, &params);

        return 0;
}

static int missedcall(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_bstream_t *bs)
{
        int ret = 0;
        aim_rxcallback_t userfunc;
        guint16 channel, nummissed, reason;
        aim_userinfo_t userinfo;

        while (aim_bstream_empty(bs)) { 

                channel = aimbs_get16(bs);
                aim_extractuserinfo(sess, bs, &userinfo);
                nummissed = aimbs_get16(bs);
                reason = aimbs_get16(bs);

                if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                         ret = userfunc(sess, rx, channel, &userinfo, nummissed, reason);
        }

        return ret;
}

/*
 * Receive the response from an ICQ status message request.  This contains the 
 * ICQ status message.  Go figure.
 */
static int clientautoresp(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_bstream_t *bs)
{
        int ret = 0;
        aim_rxcallback_t userfunc;
        guint16 channel, reason;
        char *sn;
        guint8 *ck, snlen;

        ck = aimbs_getraw(bs, 8);
        channel = aimbs_get16(bs);
        snlen = aimbs_get8(bs);
        sn = aimbs_getstr(bs, snlen);
        reason = aimbs_get16(bs);

        switch (reason) {
                case 0x0003: { /* ICQ status message.  Maybe other stuff too, you never know with these people. */
                        guint8 statusmsgtype, *msg;
                        guint16 len;
                        guint32 state;

                        len = aimbs_getle16(bs); /* Should be 0x001b */
                        aim_bstream_advance(bs, len); /* Unknown */

                        len = aimbs_getle16(bs); /* Should be 0x000e */
                        aim_bstream_advance(bs, len); /* Unknown */

                        statusmsgtype = aimbs_getle8(bs);
                        switch (statusmsgtype) {
                                case 0xe8:
                                        state = AIM_ICQ_STATE_AWAY;
                                        break;
                                case 0xe9:
                                        state = AIM_ICQ_STATE_AWAY | AIM_ICQ_STATE_BUSY;
                                        break;
                                case 0xea:
                                        state = AIM_ICQ_STATE_AWAY | AIM_ICQ_STATE_OUT;
                                        break;
                                case 0xeb:
                                        state = AIM_ICQ_STATE_AWAY | AIM_ICQ_STATE_DND | AIM_ICQ_STATE_BUSY;
                                        break;
                                case 0xec:
                                        state = AIM_ICQ_STATE_CHAT;
                                        break;
                                default:
                                        state = 0;
                                        break;
                        }

                        aimbs_getle8(bs); /* Unknown - 0x03 Maybe this means this is an auto-reply */
                        aimbs_getle16(bs); /* Unknown - 0x0000 */
                        aimbs_getle16(bs); /* Unknown - 0x0000 */

                        len = aimbs_getle16(bs);
                        msg = aimbs_getraw(bs, len);

                        if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                                ret = userfunc(sess, rx, channel, sn, reason, state, msg);

                        g_free(msg);
                } break;

                default: {
                        if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                                ret = userfunc(sess, rx, channel, sn, reason);
                } break;
        } /* end switch */

        g_free(ck);
        g_free(sn);

        return ret;
}

static int msgack(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_bstream_t *bs)
{
        aim_rxcallback_t userfunc;
        guint16 type;
        guint8 snlen, *ck;
        char *sn;
        int ret = 0;

        ck = aimbs_getraw(bs, 8);
        type = aimbs_get16(bs);
        snlen = aimbs_get8(bs);
        sn = aimbs_getstr(bs, snlen);

        if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                ret = userfunc(sess, rx, type, sn);

        g_free(sn);
        g_free(ck);

        return ret;
}

/*
 * Subtype 0x0014 - Send a mini typing notification (mtn) packet.
 *
 * This is supported by winaim5 and newer, MacAIM bleh and newer, iChat bleh and newer, 
 * and Gaim 0.60 and newer.
 *
 */
int aim_im_sendmtn(aim_session_t *sess, guint16 type1, const char *sn, guint16 type2)
{
        aim_conn_t *conn;
        aim_frame_t *fr;
        aim_snacid_t snacid;

        if (!sess || !(conn = aim_conn_findbygroup(sess, 0x0002)))
                return -EINVAL;

        if (!sn)
                return -EINVAL;

        if (!(fr = aim_tx_new(sess, conn, AIM_FRAMETYPE_FLAP, 0x02, 10+11+strlen(sn)+2)))
                return -ENOMEM;

        snacid = aim_cachesnac(sess, 0x0004, 0x0014, 0x0000, NULL, 0);
        aim_putsnac(&fr->data, 0x0004, 0x0014, 0x0000, snacid);

        /*
         * 8 days of light
         * Er, that is to say, 8 bytes of 0's
         */
        aimbs_put16(&fr->data, 0x0000);
        aimbs_put16(&fr->data, 0x0000);
        aimbs_put16(&fr->data, 0x0000);
        aimbs_put16(&fr->data, 0x0000);

        /*
         * Type 1 (should be 0x0001 for mtn)
         */
        aimbs_put16(&fr->data, type1);

        /*
         * Dest sn
         */
        aimbs_put8(&fr->data, strlen(sn));
        aimbs_putraw(&fr->data, (const guint8*)sn, strlen(sn));

        /*
         * Type 2 (should be 0x0000, 0x0001, or 0x0002 for mtn)
         */
        aimbs_put16(&fr->data, type2);

        aim_tx_enqueue(sess, fr);

        return 0;
}

/*
 * Subtype 0x0014 - Receive a mini typing notification (mtn) packet.
 *
 * This is supported by winaim5 and newer, MacAIM bleh and newer, iChat bleh and newer, 
 * and Gaim 0.60 and newer.
 *
 */
static int mtn_receive(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_bstream_t *bs)
{
        int ret = 0;
        aim_rxcallback_t userfunc;
        char *sn;
        guint8 snlen;
        guint16 type1, type2;

        aim_bstream_advance(bs, 8); /* Unknown - All 0's */
        type1 = aimbs_get16(bs);
        snlen = aimbs_get8(bs);
        sn = aimbs_getstr(bs, snlen);
        type2 = aimbs_get16(bs);

        if ((userfunc = aim_callhandler(sess, rx->conn, snac->family, snac->subtype)))
                ret = userfunc(sess, rx, type1, sn, type2);

        g_free(sn);

        return ret;
}

static int snachandler(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_bstream_t *bs)
{

        if (snac->subtype == 0x0005)
                return paraminfo(sess, mod, rx, snac, bs);
        else if (snac->subtype == 0x0006)
                return outgoingim(sess, mod, rx, snac, bs);
        else if (snac->subtype == 0x0007)
                return incomingim(sess, mod, rx, snac, bs);
        else if (snac->subtype == 0x000a)
                return missedcall(sess, mod, rx, snac, bs);
        else if (snac->subtype == 0x000b)
                return clientautoresp(sess, mod, rx, snac, bs);
        else if (snac->subtype == 0x000c)
                return msgack(sess, mod, rx, snac, bs);
        else if (snac->subtype == 0x0014)
                return mtn_receive(sess, mod, rx, snac, bs);

        return 0;
}

int msg_modfirst(aim_session_t *sess, aim_module_t *mod)
{

        mod->family = 0x0004;
        mod->version = 0x0001;
        mod->toolid = 0x0110;
        mod->toolversion = 0x0629;
        mod->flags = 0;
        strncpy(mod->name, "messaging", sizeof(mod->name));
        mod->snachandler = snachandler;

        return 0;
}