im.c

oscar message protocol stack

/*
 * Family 0x0004 - Routines for sending/receiving Instant Messages.
 *
 * Note the term ICBM (Inter-Client Basic Message) which blankets
 * all types of generically 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.  Channel 3 is used for chat messages (not in 
 * the same family as these channels).  Channel 4 is used for 
 * various ICQ messages.  Examples are normal messages, URLs, and 
 * old-style authorization.
 *
 * 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.
 *
 * TODO: Split this up into an im.c file an an icbm.c file.  It 
 *       will be beautiful, you'll see.
 *
 *       Need to rename all the mpmsg messages to aim_im_bleh.
 *
 *       Make sure aim_conn_findbygroup is used by all functions.
 */

#define FAIM_INTERNAL
#include <aim.h>

#ifdef _WIN32
#include "win32dep.h"
#endif

/**
 * Add a standard ICBM header to the given bstream with the given 
 * information.
 *
 * @param bs The bstream to write the ICBM header to.
 * @param c c is for cookie, and cookie is for me.
 * @param ch The ICBM channel (1 through 4).
 * @param sn Null-terminated scrizeen nizame.
 * @return The number of bytes written.  It's really not useful.
 */
static int aim_im_puticbm(aim_bstream_t *bs, const fu8_t *c, fu16_t ch, const char *sn)
{
	aimbs_putraw(bs, c, 8);
	aimbs_put16(bs, ch);
	aimbs_put8(bs, strlen(sn));
	aimbs_putraw(bs, sn, strlen(sn));
	return 8+2+1+strlen(sn);
}

/*
 * Takes a msghdr (and a length) and returns a client type
 * code.  Note that this is *only a guess* and has a low likelihood
 * of actually being accurate.
 *
 * Its based on experimental data, with the help of Eric Warmenhoven
 * who seems to have collected a wide variety of different AIM clients.
 *
 *
 * Heres the current collection:
 *  0501 0003 0101 0101 01		AOL Mobile Communicator, WinAIM 1.0.414
 *  0501 0003 0101 0201 01		WinAIM 2.0.847, 2.1.1187, 3.0.1464, 
 *					4.3.2229, 4.4.2286
 *  0501 0004 0101 0102 0101		WinAIM 4.1.2010, libfaim (right here)
 *  0501 0003 0101 02			WinAIM 5
 *  0501 0001 01			iChat x.x, mobile buddies
 *  0501 0001 0101 01			AOL v6.0, CompuServe 2000 v6.0, any TOC client
 *  0501 0002 0106			WinICQ 5.45.1.3777.85
 *
 * Note that in this function, only the feature bytes are tested, since
 * the rest will always be the same.
 *
 */
faim_export fu16_t aim_im_fingerprint(const fu8_t *msghdr, int len)
{
	static const struct {
		fu16_t clientid;
		int len;
		fu8_t data[10];
	} fingerprints[] = {
		/* AOL Mobile Communicator, WinAIM 1.0.414 */
		{ AIM_CLIENTTYPE_MC, 
		  3, {0x01, 0x01, 0x01}},

		/* WinAIM 2.0.847, 2.1.1187, 3.0.1464, 4.3.2229, 4.4.2286 */
		{ AIM_CLIENTTYPE_WINAIM, 
		  3, {0x01, 0x01, 0x02}},

		/* WinAIM 4.1.2010, libfaim */
		{ AIM_CLIENTTYPE_WINAIM41,
		  4, {0x01, 0x01, 0x01, 0x02}},

		/* AOL v6.0, CompuServe 2000 v6.0, any TOC client */
		{ AIM_CLIENTTYPE_AOL_TOC,
		  1, {0x01}},

		{ 0, 0}
	};
	int i;

	if (!msghdr || (len <= 0))
		return AIM_CLIENTTYPE_UNKNOWN;

	for (i = 0; fingerprints[i].len; i++) {
		if (fingerprints[i].len != len)
			continue;
		if (memcmp(fingerprints[i].data, msghdr, fingerprints[i].len) == 0)
			return fingerprints[i].clientid;
	}

	return AIM_CLIENTTYPE_UNKNOWN;
}

/** 
 * Subtype 0x0002 - Set ICBM parameters.
 *
 * I definitely recommend sending this.  If you don't, you'll be stuck
 * with the rather unreasonable defaults.
 * 
 */
faim_export int aim_im_setparams(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;
}

/**
 * Subtype 0x0004 - Request ICBM parameter information.
 *
 */
faim_export int aim_im_reqparams(aim_session_t *sess)
{
	aim_conn_t *conn;

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

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

/**
 * Subtype 0x0005 - Receive parameter information.
 *
 */
static int aim_im_paraminfo(aim_session_t *sess, aim_module_t *mod, aim_frame_t *rx, aim_modsnac_t *snac, aim_bstream_t *bs)
{
	aim_rxcallback_t userfunc;
	struct aim_icbmparameters params;

	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;
}

/**
 * Subtype 0x0006 - 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).
 *
 * 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 equivalent 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
 *
 */
faim_export int aim_im_sendch1_ext(aim_session_t *sess, struct aim_sendimext_args *args)
{
	aim_conn_t *conn;
	aim_frame_t *fr;
	aim_snacid_t snacid;
	fu8_t ck[8];
	int i, msgtlvlen;
	static const fu8_t deffeatures[] = { 0x01, 0x01, 0x01, 0x02 };

	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++)
		ck[i] = (fu8_t)rand();

	/* ICBM header */
	aim_im_puticbm(&fr->data, ck, 0x0001, args->destsn);

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

	/* Features TLV (type 0x0501) */
	aimbs_put16(&fr->data, 0x0501);
	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;

		/* Insert each message part in a TLV (type 0x0101) */
		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 {

		/* Insert message text in a TLV (type 0x0101) */
		aimbs_put16(&fr->data, 0x0101);

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

		/* Character set */
		aimbs_put16(&fr->data, args->charset);
		aimbs_put16(&fr->data, args->charsubset);

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

	/* Set the Autoresponse flag */
	if (args->flags & AIM_IMFLAGS_AWAY) {
		aimbs_put16(&fr->data, 0x0004);
		aimbs_put16(&fr->data, 0x0000);
	} else if (args->flags & AIM_IMFLAGS_ACK) {
		/* Set the Request Acknowledge flag */
		aimbs_put16(&fr->data, 0x0003);
		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.
	 * XXX - This should really only be sent on initial 
	 * IMs and when you change your icon.
	 */
	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.
	 * XXX - Every time?  Surely not...
	 */
	if (args->flags & AIM_IMFLAGS_BUDDYREQ) {
		aimbs_put16(&fr->data, 0x0009);
		aimbs_put16(&fr->data, 0x0000);
	}

	aim_tx_enqueue(sess, fr);

	/* clean out SNACs over 60sec old */
	aim_cleansnacs(sess, 60);

	return 0;
}

/*
 * Simple wrapper for aim_im_sendch1_ext() 
 *
 * You cannot use aim_send_im if you need the HASICON flag.  You must
 * use aim_im_sendch1_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_im_sendch1_ext().
 *
 */
faim_export int aim_im_sendch1(aim_session_t *sess, const char *sn, fu16_t flags, const char *msg)
{
	struct aim_sendimext_args args;

	args.destsn = sn;
	args.flags = flags;
	args.msg = msg;
	args.msglen = strlen(msg);
	args.charset = 0x0000;
	args.charsubset = 0x0000;

	/* Make these don't get set by accident -- they need aim_im_sendch1_ext */
	args.flags &= ~(AIM_IMFLAGS_CUSTOMFEATURES | AIM_IMFLAGS_HASICON | AIM_IMFLAGS_MULTIPART);

	return aim_im_sendch1_ext(sess, &args);
}

/*
 * Subtype 0x0006 - Send a chat invitation.
 */
faim_export int aim_im_sendch2_chatinvite(aim_session_t *sess, const char *sn, const char *msg, fu16_t exchange, const char *roomname, fu16_t instance)
{
	aim_conn_t *conn;
	aim_frame_t *fr;
	aim_snacid_t snacid;
	int i;
	aim_msgcookie_t *cookie;
	struct aim_invite_priv *priv;
	fu8_t ck[8];
	aim_tlvlist_t *otl = NULL, *itl = NULL;
	fu8_t *hdr;
	int hdrlen;
	aim_bstream_t hdrbs;
	
	if (!sess || !(conn = aim_conn_findbygroup(sess, 0x0004)))
		return -EINVAL;

	if (!sn || !msg || !roomname)
		return -EINVAL;

	for (i = 0; i < 8; i++)
		ck[i] = (fu8_t)rand();

	if (!(fr = aim_tx_new(sess, conn, AIM_FRAMETYPE_FLAP, 0x02, 1152+strlen(sn)+strlen(roomname)+strlen(msg))))
		return -ENOMEM;

	snacid = aim_cachesnac(sess, 0x0004, 0x0006, 0x0000, sn, strlen(sn)+1);
	aim_putsnac(&fr->data, 0x0004, 0x0006, 0x0000, snacid);

	/* XXX should be uncached by an unwritten 'invite accept' handler */
	if ((priv = malloc(sizeof(struct aim_invite_priv)))) {
		priv->sn = strdup(sn);
		priv->roomname = strdup(roomname);
		priv->exchange = exchange;
		priv->instance = instance;
	}

	if ((cookie = aim_mkcookie(ck, AIM_COOKIETYPE_INVITE, priv)))
		aim_cachecookie(sess, cookie);
	else
		free(priv);

	/* ICBM Header */
	aimbs_putraw(&fr->data, ck, 8); /* Cookie */