tlv.c

oscar message protocol stack

/**
 * Add a four byte integer to a TLV chain.
 *
 * @param list Destination chain.
 * @param type TLV type to add.
 * @param value Value to add.
 * @return The size of the value added.
 */
faim_internal int aim_tlvlist_add_32(aim_tlvlist_t **list, const fu16_t type, const fu32_t value)
{
	fu8_t v32[4];

	aimutil_put32(v32, value);

	return aim_tlvlist_add_raw(list, type, 4, v32);
}

/**
 * Adds a block of capability blocks to a TLV chain. The bitfield
 * passed in should be a bitwise %OR of any of the %AIM_CAPS constants:
 *
 *     %AIM_CAPS_BUDDYICON   Supports Buddy Icons
 *     %AIM_CAPS_TALK        Supports Voice Chat
 *     %AIM_CAPS_IMIMAGE     Supports DirectIM/IMImage
 *     %AIM_CAPS_CHAT        Supports Chat
 *     %AIM_CAPS_GETFILE     Supports Get File functions
 *     %AIM_CAPS_SENDFILE    Supports Send File functions
 *
 * @param list Destination chain
 * @param type TLV type to add
 * @param caps Bitfield of capability flags to send
 * @return The size of the value added.
 */
faim_internal int aim_tlvlist_add_caps(aim_tlvlist_t **list, const fu16_t type, const fu32_t caps)
{
	fu8_t buf[16*16]; /* XXX icky fixed length buffer */
	aim_bstream_t bs;

	if (!caps)
		return 0; /* nothing there anyway */

	aim_bstream_init(&bs, buf, sizeof(buf));

	aim_putcap(&bs, caps);

	return aim_tlvlist_add_raw(list, type, aim_bstream_curpos(&bs), buf);
}

/**
 * Adds the given userinfo struct to a TLV chain.
 *
 * @param list Destination chain.
 * @param type TLV type to add.
 * @return The size of the value added.
 */
faim_internal int aim_tlvlist_add_userinfo(aim_tlvlist_t **list, fu16_t type, aim_userinfo_t *userinfo)
{
	fu8_t buf[1024]; /* bleh */
	aim_bstream_t bs;

	aim_bstream_init(&bs, buf, sizeof(buf));

	aim_putuserinfo(&bs, userinfo);

	return aim_tlvlist_add_raw(list, type, aim_bstream_curpos(&bs), buf);
}

/**
 * Adds the given chatroom info to a TLV chain.
 *
 * @param list Destination chain.
 * @param type TLV type to add.
 * @param roomname The name of the chat.
 * @param instance The instance.
 * @return The size of the value added.
 */
faim_internal int aim_tlvlist_add_chatroom(aim_tlvlist_t **list, fu16_t type, fu16_t exchange, const char *roomname, fu16_t instance)
{
	fu8_t *buf;
	int len;
	aim_bstream_t bs;

	len = 2 + 1 + strlen(roomname) + 2;
	
	if (!(buf = malloc(len)))
		return 0;

	aim_bstream_init(&bs, buf, len);

	aimbs_put16(&bs, exchange);
	aimbs_put8(&bs, strlen(roomname));
	aimbs_putraw(&bs, roomname, strlen(roomname));
	aimbs_put16(&bs, instance);

	len = aim_tlvlist_add_raw(list, type, aim_bstream_curpos(&bs), buf);

	free(buf);

	return len;
}

/**
 * Adds a TLV with a zero length to a TLV chain.
 *
 * @param list Destination chain.
 * @param type TLV type to add.
 * @return The size of the value added.
 */
faim_internal int aim_tlvlist_add_noval(aim_tlvlist_t **list, const fu16_t type)
{
	return aim_tlvlist_add_raw(list, type, 0, NULL);
}

/*
 * Note that the inner TLV chain will not be modifiable as a tlvchain once
 * it is written using this.  Or rather, it can be, but updates won't be
 * made to this.
 *
 * XXX should probably support sublists for real.
 * 
 * This is so neat.
 *
 * @param list Destination chain.
 * @param type TLV type to add.
 * @param t1 The TLV chain you want to write.
 * @return The number of bytes written to the destination TLV chain.
 *         0 is returned if there was an error or if the destination
 *         TLV chain has length 0.
 */
faim_internal int aim_tlvlist_add_frozentlvlist(aim_tlvlist_t **list, fu16_t type, aim_tlvlist_t **tl)
{
	fu8_t *buf;
	int buflen;
	aim_bstream_t bs;

	buflen = aim_tlvlist_size(tl);

	if (buflen <= 0)
		return 0;

	if (!(buf = malloc(buflen)))
		return 0;

	aim_bstream_init(&bs, buf, buflen);

	aim_tlvlist_write(&bs, tl);

	aim_tlvlist_add_raw(list, type, aim_bstream_curpos(&bs), buf);

	free(buf);

	return buflen;
}

/**
 * Substitute a TLV of a given type with a new TLV of the same type.  If 
 * you attempt to replace a TLV that does not exist, this function will 
 * just add a new TLV as if you called aim_tlvlist_add_raw().
 *
 * @param list Desination chain (%NULL pointer if empty).
 * @param type TLV type.
 * @param length Length of string to add (not including %NULL).
 * @param value String to add.
 * @return The length of the TLV.
 */
faim_internal int aim_tlvlist_replace_raw(aim_tlvlist_t **list, const fu16_t type, const fu16_t length, const fu8_t *value)
{
	aim_tlvlist_t *cur;

	if (list == NULL)
		return 0;

	for (cur = *list; ((cur != NULL) && (cur->tlv->type != type)); cur = cur->next);
	if (cur == NULL)
		return aim_tlvlist_add_raw(list, type, length, value);

	free(cur->tlv->value);
	cur->tlv->length = length;
	if (cur->tlv->length > 0) {
		cur->tlv->value = (fu8_t *)malloc(cur->tlv->length);
		memcpy(cur->tlv->value, value, cur->tlv->length);
	} else
		cur->tlv->value = NULL;

	return cur->tlv->length;
}

/**
 * Substitute a TLV of a given type with a new TLV of the same type.  If 
 * you attempt to replace a TLV that does not exist, this function will 
 * just add a new TLV as if you called aim_tlvlist_add_raw().
 *
 * @param list Desination chain (%NULL pointer if empty).
 * @param type TLV type.
 * @return The length of the TLV.
 */
faim_internal int aim_tlvlist_replace_noval(aim_tlvlist_t **list, const fu16_t type)
{
	return aim_tlvlist_replace_raw(list, type, 0, NULL);
}

/**
 * Substitute a TLV of a given type with a new TLV of the same type.  If 
 * you attempt to replace a TLV that does not exist, this function will 
 * just add a new TLV as if you called aim_tlvlist_add_raw().
 *
 * @param list Desination chain (%NULL pointer if empty).
 * @param type TLV type.
 * @param value 8 bit value to add.
 * @return The length of the TLV.
 */
faim_internal int aim_tlvlist_replace_8(aim_tlvlist_t **list, const fu16_t type, const fu8_t value)
{
	fu8_t v8[1];

	aimutil_put8(v8, value);

	return aim_tlvlist_replace_raw(list, type, 1, v8);
}

/**
 * Substitute a TLV of a given type with a new TLV of the same type.  If 
 * you attempt to replace a TLV that does not exist, this function will 
 * just add a new TLV as if you called aim_tlvlist_add_raw().
 *
 * @param list Desination chain (%NULL pointer if empty).
 * @param type TLV type.
 * @param value 32 bit value to add.
 * @return The length of the TLV.
 */
faim_internal int aim_tlvlist_replace_32(aim_tlvlist_t **list, const fu16_t type, const fu32_t value)
{
	fu8_t v32[4];

	aimutil_put32(v32, value);

	return aim_tlvlist_replace_raw(list, type, 4, v32);
}

/**
 * Remove a TLV of a given type.  If you attempt to remove a TLV that 
 * does not exist, nothing happens.
 *
 * @param list Desination chain (%NULL pointer if empty).
 * @param type TLV type.
 */
faim_internal void aim_tlvlist_remove(aim_tlvlist_t **list, const fu16_t type)
{
	aim_tlvlist_t *del;

	if (!list || !(*list))
		return;

	/* Remove the item from the list */
	if ((*list)->tlv->type == type) {
		del = *list;
		*list = (*list)->next;
	} else {
		aim_tlvlist_t *cur;
		for (cur=*list; (cur->next && (cur->next->tlv->type!=type)); cur=cur->next);
		if (!cur->next)
			return;
		del = cur->next;
		cur->next = del->next;
	}

	/* Free the removed item */
	free(del->tlv->value);
	free(del->tlv);
	free(del);
}

/**
 * Write a TLV chain into a data buffer.
 *
 * Copies a TLV chain into a raw data buffer, writing only the number
 * of bytes specified. This operation does not free the chain; 
 * aim_tlvlist_free() must still be called to free up the memory used
 * by the chain structures.
 *
 * XXX clean this up, make better use of bstreams 
 *
 * @param bs Input bstream
 * @param list Source TLV chain
 * @return Return 0 if the destination bstream is too small.
 */
faim_internal int aim_tlvlist_write(aim_bstream_t *bs, aim_tlvlist_t **list)
{
	int goodbuflen;
	aim_tlvlist_t *cur;

	/* do an initial run to test total length */
	goodbuflen = aim_tlvlist_size(list);

	if (goodbuflen > aim_bstream_empty(bs))
		return 0; /* not enough buffer */

	/* do the real write-out */
	for (cur = *list; cur; cur = cur->next) {
		aimbs_put16(bs, cur->tlv->type);
		aimbs_put16(bs, cur->tlv->length);
		if (cur->tlv->length)
			aimbs_putraw(bs, cur->tlv->value, cur->tlv->length);
	}

	return 1; /* XXX this is a nonsensical return */
}


/**
 * Grab the Nth TLV of type type in the TLV list list.
 *
 * Returns a pointer to an aim_tlv_t of the specified type; 
 * %NULL on error.  The @nth parameter is specified starting at %1.
 * In most cases, there will be no more than one TLV of any type
 * in a chain.
 *
 * @param list Source chain.
 * @param type Requested TLV type.
 * @param nth Index of TLV of type to get.
 * @return The TLV you were looking for, or NULL if one could not be found.
 */
faim_internal aim_tlv_t *aim_tlv_gettlv(aim_tlvlist_t *list, const fu16_t type, const int nth)
{
	aim_tlvlist_t *cur;
	int i;

	for (cur = list, i = 0; cur; cur = cur->next) {
		if (cur && cur->tlv) {
			if (cur->tlv->type == type)
				i++;
			if (i >= nth)
				return cur->tlv;
		}
	}

	return NULL;
}

/**
 * Get the length of the data of the nth TLV in the given TLV chain.
 *
 * @param list Source chain.
 * @param type Requested TLV type.
 * @param nth Index of TLV of type to get.
 * @return The length of the data in this TLV, or -1 if the TLV could not be
 *         found.  Unless -1 is returned, this value will be 2 bytes.
 */
faim_internal int aim_tlv_getlength(aim_tlvlist_t *list, const fu16_t type, const int nth)
{
	aim_tlvlist_t *cur;
	int i;

	for (cur = list, i = 0; cur; cur = cur->next) {
		if (cur && cur->tlv) {
			if (cur->tlv->type == type)
				i++;
			if (i >= nth)
				return cur->tlv->length;
		}
	}

	return -1;
}

/**
 * Retrieve the data from the nth TLV in the given TLV chain as a string.
 *
 * @param list Source TLV chain.
 * @param type TLV type to search for.
 * @param nth Index of TLV to return.
 * @return The value of the TLV you were looking for, or NULL if one could 
 *         not be found.  This is a dynamic buffer and must be freed by the 
 *         caller.
 */
faim_internal char *aim_tlv_getstr(aim_tlvlist_t *list, const fu16_t type, const int nth)
{
	aim_tlv_t *tlv;
	char *newstr;

	if (!(tlv = aim_tlv_gettlv(list, type, nth)))
		return NULL;

	newstr = (char *) malloc(tlv->length + 1);
	memcpy(newstr, tlv->value, tlv->length);
	newstr[tlv->length] = '\0';

	return newstr;
}

/**
 * Retrieve the data from the nth TLV in the given TLV chain as an 8bit 
 * integer.
 *
 * @param list Source TLV chain.
 * @param type TLV type to search for.
 * @param nth Index of TLV to return.
 * @return The value the TLV you were looking for, or 0 if one could 
 *         not be found.
 */
faim_internal fu8_t aim_tlv_get8(aim_tlvlist_t *list, const fu16_t type, const int nth)
{
	aim_tlv_t *tlv;

	if (!(tlv = aim_tlv_gettlv(list, type, nth)))
		return 0; /* erm */
	return aimutil_get8(tlv->value);
}

/**
 * Retrieve the data from the nth TLV in the given TLV chain as a 16bit 
 * integer.
 *
 * @param list Source TLV chain.
 * @param type TLV type to search for.
 * @param nth Index of TLV to return.
 * @return The value the TLV you were looking for, or 0 if one could 
 *         not be found.
 */
faim_internal fu16_t aim_tlv_get16(aim_tlvlist_t *list, const fu16_t type, const int nth)
{
	aim_tlv_t *tlv;

	if (!(tlv = aim_tlv_gettlv(list, type, nth)))
		return 0; /* erm */
	return aimutil_get16(tlv->value);
}

/**
 * Retrieve the data from the nth TLV in the given TLV chain as a 32bit 
 * integer.
 *
 * @param list Source TLV chain.
 * @param type TLV type to search for.
 * @param nth Index of TLV to return.
 * @return The value the TLV you were looking for, or 0 if one could 
 *         not be found.
 */
faim_internal fu32_t aim_tlv_get32(aim_tlvlist_t *list, const fu16_t type, const int nth)
{
	aim_tlv_t *tlv;

	if (!(tlv = aim_tlv_gettlv(list, type, nth)))
		return 0; /* erm */
	return aimutil_get32(tlv->value);
}