tlv.c

oscar message protocol stack

#define FAIM_INTERNAL
#include <aim.h>

static aim_tlv_t *createtlv(fu16_t type, fu16_t length, fu8_t *value)
{
	aim_tlv_t *ret;

	if (!(ret = (aim_tlv_t *)malloc(sizeof(aim_tlv_t))))
		return NULL;
	ret->type = type;
	ret->length = length;
	ret->value = value;

	return ret;
}

static void freetlv(aim_tlv_t **oldtlv)
{

	if (!oldtlv || !*oldtlv)
		return;
	
	free((*oldtlv)->value);
	free(*oldtlv);
	*oldtlv = NULL;

	return;
}

/**
 * Read a TLV chain from a buffer.
 *
 * Reads and parses a series of TLV patterns from a data buffer; the
 * returned structure is manipulatable with the rest of the TLV
 * routines.  When done with a TLV chain, aim_tlvlist_free() should
 * be called to free the dynamic substructures.
 *
 * XXX There should be a flag setable here to have the tlvlist contain
 * bstream references, so that at least the ->value portion of each 
 * element doesn't need to be malloc/memcpy'd.  This could prove to be
 * just as efficient as the in-place TLV parsing used in a couple places
 * in libfaim.
 *
 * @param bs Input bstream
 * @return Return the TLV chain read
 */
faim_internal aim_tlvlist_t *aim_tlvlist_read(aim_bstream_t *bs)
{
	aim_tlvlist_t *list = NULL, *cur;
	
	while (aim_bstream_empty(bs) > 0) {
		fu16_t type, length;

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

#if 0 /* temporarily disabled until I know if they're still doing it or not */
		/*
		 * Okay, so now AOL has decided that any TLV of
		 * type 0x0013 can only be two bytes, despite
		 * what the actual given length is.  So here 
		 * we dump any invalid TLVs of that sort.  Hopefully
		 * there's no special cases to this special case.
		 *   - mid (30jun2000)
		 */
		if ((type == 0x0013) && (length != 0x0002))
			length = 0x0002;
#else
		if (0)
			;
#endif
		else {

			if (length > aim_bstream_empty(bs)) {
				aim_tlvlist_free(&list);
				return NULL;
			}

			cur = (aim_tlvlist_t *)malloc(sizeof(aim_tlvlist_t));
			if (!cur) {
				aim_tlvlist_free(&list);
				return NULL;
			}

			memset(cur, 0, sizeof(aim_tlvlist_t));

			cur->tlv = createtlv(type, length, NULL);
			if (!cur->tlv) {
				free(cur);
				aim_tlvlist_free(&list);
				return NULL;
			}
			if (cur->tlv->length > 0) {
				cur->tlv->value = aimbs_getraw(bs, length);	
				if (!cur->tlv->value) {
					freetlv(&cur->tlv);
					free(cur);
					aim_tlvlist_free(&list);
					return NULL;
				}
			}

			cur->next = list;
			list = cur;
		}
	}

	return list;
}

/**
 * Read a TLV chain from a buffer.
 *
 * Reads and parses a series of TLV patterns from a data buffer; the
 * returned structure is manipulatable with the rest of the TLV
 * routines.  When done with a TLV chain, aim_tlvlist_free() should
 * be called to free the dynamic substructures.
 *
 * XXX There should be a flag setable here to have the tlvlist contain
 * bstream references, so that at least the ->value portion of each 
 * element doesn't need to be malloc/memcpy'd.  This could prove to be
 * just as efficient as the in-place TLV parsing used in a couple places
 * in libfaim.
 *
 * @param bs Input bstream
 * @param num The max number of TLVs that will be read, or -1 if unlimited.  
 *        There are a number of places where you want to read in a tlvchain, 
 *        but the chain is not at the end of the SNAC, and the chain is 
 *        preceded by the number of TLVs.  So you can limit that with this.
 * @return Return the TLV chain read
 */
faim_internal aim_tlvlist_t *aim_tlvlist_readnum(aim_bstream_t *bs, fu16_t num)
{
	aim_tlvlist_t *list = NULL, *cur;

	while ((aim_bstream_empty(bs) > 0) && (num != 0)) {
		fu16_t type, length;

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

		if (length > aim_bstream_empty(bs)) {
			aim_tlvlist_free(&list);
			return NULL;
		}

		cur = (aim_tlvlist_t *)malloc(sizeof(aim_tlvlist_t));
		if (!cur) {
			aim_tlvlist_free(&list);
			return NULL;
		}

		memset(cur, 0, sizeof(aim_tlvlist_t));

		cur->tlv = createtlv(type, length, NULL);
		if (!cur->tlv) {
			free(cur);
			aim_tlvlist_free(&list);
			return NULL;
		}
		if (cur->tlv->length > 0) {
			cur->tlv->value = aimbs_getraw(bs, length);
			if (!cur->tlv->value) {
				freetlv(&cur->tlv);
				free(cur);
				aim_tlvlist_free(&list);
				return NULL;
			}
		}

		if (num > 0)
			num--;
		cur->next = list;
		list = cur;
	}

	return list;
}

/**
 * Read a TLV chain from a buffer.
 *
 * Reads and parses a series of TLV patterns from a data buffer; the
 * returned structure is manipulatable with the rest of the TLV
 * routines.  When done with a TLV chain, aim_tlvlist_free() should
 * be called to free the dynamic substructures.
 *
 * XXX There should be a flag setable here to have the tlvlist contain
 * bstream references, so that at least the ->value portion of each 
 * element doesn't need to be malloc/memcpy'd.  This could prove to be
 * just as efficient as the in-place TLV parsing used in a couple places
 * in libfaim.
 *
 * @param bs Input bstream
 * @param len The max length in bytes that will be read.
 *        There are a number of places where you want to read in a tlvchain, 
 *        but the chain is not at the end of the SNAC, and the chain is 
 *        preceded by the length of the TLVs.  So you can limit that with this.
 * @return Return the TLV chain read
 */
faim_internal aim_tlvlist_t *aim_tlvlist_readlen(aim_bstream_t *bs, fu16_t len)
{
	aim_tlvlist_t *list = NULL, *cur;

	while ((aim_bstream_empty(bs) > 0) && (len > 0)) {
		fu16_t type, length;

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

		if (length > aim_bstream_empty(bs)) {
			aim_tlvlist_free(&list);
			return NULL;
		}

		cur = (aim_tlvlist_t *)malloc(sizeof(aim_tlvlist_t));
		if (!cur) {
			aim_tlvlist_free(&list);
			return NULL;
		}

		memset(cur, 0, sizeof(aim_tlvlist_t));

		cur->tlv = createtlv(type, length, NULL);
		if (!cur->tlv) {
			free(cur);
			aim_tlvlist_free(&list);
			return NULL;
		}
		if (cur->tlv->length > 0) {
			cur->tlv->value = aimbs_getraw(bs, length);
			if (!cur->tlv->value) {
				freetlv(&cur->tlv);
				free(cur);
				aim_tlvlist_free(&list);
				return NULL;
			}
		}

		len -= aim_tlvlist_size(&cur);
		cur->next = list;
		list = cur;
	}

	return list;
}

/**
 * Duplicate a TLV chain.
 * This is pretty self explanatory.
 *
 * @param orig The TLV chain you want to make a copy of.
 * @return A newly allocated TLV chain.
 */
faim_internal aim_tlvlist_t *aim_tlvlist_copy(aim_tlvlist_t *orig)
{
	aim_tlvlist_t *new = NULL;

	while (orig) {
		aim_tlvlist_add_raw(&new, orig->tlv->type, orig->tlv->length, orig->tlv->value);
		orig = orig->next;
	}

	return new;
}

/*
 * Compare two TLV lists for equality.  This probably is not the most 
 * efficient way to do this.
 *
 * @param one One of the TLV chains to compare.
 * @param two The other TLV chain to compare.
 * @return Return 0 if the lists are the same, return 1 if they are different.
 */
faim_internal int aim_tlvlist_cmp(aim_tlvlist_t *one, aim_tlvlist_t *two)
{
	aim_bstream_t bs1, bs2;

	if (aim_tlvlist_size(&one) != aim_tlvlist_size(&two))
		return 1;

	aim_bstream_init(&bs1, ((fu8_t *)malloc(aim_tlvlist_size(&one)*sizeof(fu8_t))), aim_tlvlist_size(&one));
	aim_bstream_init(&bs2, ((fu8_t *)malloc(aim_tlvlist_size(&two)*sizeof(fu8_t))), aim_tlvlist_size(&two));

	aim_tlvlist_write(&bs1, &one);
	aim_tlvlist_write(&bs2, &two);

	if (memcmp(bs1.data, bs2.data, bs1.len)) {
		free(bs1.data);
		free(bs2.data);
		return 1;
	}

	free(bs1.data);
	free(bs2.data);

	return 0;
}

/**
 * Free a TLV chain structure
 *
 * Walks the list of TLVs in the passed TLV chain and
 * frees each one. Note that any references to this data
 * should be removed before calling this.
 *
 * @param list Chain to be freed
 */
faim_internal void aim_tlvlist_free(aim_tlvlist_t **list)
{
	aim_tlvlist_t *cur;

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

	for (cur = *list; cur; ) {
		aim_tlvlist_t *tmp;
		
		freetlv(&cur->tlv);

		tmp = cur->next;
		free(cur);
		cur = tmp;
	}

	list = NULL;

	return;
}

/**
 * Count the number of TLVs in a chain.
 *
 * @param list Chain to be counted.
 * @return The number of TLVs stored in the passed chain.
 */
faim_internal int aim_tlvlist_count(aim_tlvlist_t **list)
{
	aim_tlvlist_t *cur;
	int count;

	if (!list || !*list)
		return 0;

	for (cur = *list, count = 0; cur; cur = cur->next)
		count++;

	return count;
}

/**
 * Count the number of bytes in a TLV chain.
 *
 * @param list Chain to be sized
 * @return The number of bytes that would be needed to 
 *         write the passed TLV chain to a data buffer.
 */
faim_internal int aim_tlvlist_size(aim_tlvlist_t **list)
{
	aim_tlvlist_t *cur;
	int size;

	if (!list || !*list)
		return 0;

	for (cur = *list, size = 0; cur; cur = cur->next)
		size += (4 + cur->tlv->length);

	return size;
}

/**
 * Adds the passed string as a TLV element of the passed type
 * to the TLV chain.
 *
 * @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 size of the value added.
 */
faim_internal int aim_tlvlist_add_raw(aim_tlvlist_t **list, const fu16_t type, const fu16_t length, const fu8_t *value)
{
	aim_tlvlist_t *newtlv, *cur;

	if (list == NULL)
		return 0;

	if (!(newtlv = (aim_tlvlist_t *)malloc(sizeof(aim_tlvlist_t))))
		return 0;
	memset(newtlv, 0x00, sizeof(aim_tlvlist_t));

	if (!(newtlv->tlv = createtlv(type, length, NULL))) {
		free(newtlv);
		return 0;
	}
	if (newtlv->tlv->length > 0) {
		newtlv->tlv->value = (fu8_t *)malloc(newtlv->tlv->length);
		memcpy(newtlv->tlv->value, value, newtlv->tlv->length);
	}

	if (!*list)
		*list = newtlv;
	else {
		for(cur = *list; cur->next; cur = cur->next)
			;
		cur->next = newtlv;
	}

	return newtlv->tlv->length;
}

/**
 * Add a one 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_8(aim_tlvlist_t **list, const fu16_t type, const fu8_t value)
{
	fu8_t v8[1];

	aimutil_put8(v8, value);

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

/**
 * Add a two 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_16(aim_tlvlist_t **list, const fu16_t type, const fu16_t value)
{
	fu8_t v16[2];

	aimutil_put16(v16, value);

	return aim_tlvlist_add_raw(list, type, 2, v16);
}