source: libfaim/tlv.c @ aef17f2

#define FAIM_INTERNAL
#include <aim.h>

static aim_tlv_t *createtlv(void)
{
        aim_tlv_t *newtlv;

        if (!(newtlv = (aim_tlv_t *)malloc(sizeof(aim_tlv_t))))
                return NULL;
        memset(newtlv, 0, sizeof(aim_tlv_t));

        return newtlv;
}

static void freetlv(aim_tlv_t **oldtlv)
{

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

        return;
}

/**
 * aim_readtlvchain - Read a TLV chain from a buffer.
 * @buf: Input buffer
 * @maxlen: Length of input 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_freetlvchain() 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 effecient as the in-place TLV parsing used in a couple places
 * in libfaim.
 *
 */
faim_internal aim_tlvlist_t *aim_readtlvchain(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
                 * theres 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))
                                goto errout;

                        cur = (aim_tlvlist_t *)malloc(sizeof(aim_tlvlist_t));
                        if (!cur)
                                goto errout;

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

                        cur->tlv = createtlv(); 
                        if (!cur->tlv) {
                                free(cur);
                                goto errout;
                        }
                        cur->tlv->type = type;
                        if ((cur->tlv->length = length)) {
                               cur->tlv->value = aimbs_getraw(bs, length);      
                               if (!cur->tlv->value) {
                                       freetlv(&cur->tlv);
                                       free(cur);
                                       goto errout;
                               }
                        }

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

        return list;

errout:
        aim_freetlvchain(&list);
        return NULL;
}

/**
 * aim_freetlvchain - Free a TLV chain structure
 * @list: Chain to be freed
 *
 * 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.
 *
 */
faim_internal void aim_freetlvchain(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;
}

/**
 * aim_counttlvchain - Count the number of TLVs in a chain
 * @list: Chain to be counted
 *
 * Returns the number of TLVs stored in the passed chain.
 *
 */
faim_internal int aim_counttlvchain(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;
}

/**
 * aim_sizetlvchain - Count the number of bytes in a TLV chain
 * @list: Chain to be sized
 *
 * Returns the number of bytes that would be needed to 
 * write the passed TLV chain to a data buffer.
 *
 */
faim_internal int aim_sizetlvchain(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;
}

/**
 * aim_addtlvtochain_str - Add a string to a TLV chain
 * @list: Desination chain (%NULL pointer if empty)
 * @type: TLV type
 * @str: String to add
 * @len: Length of string to add (not including %NULL)
 *
 * Adds the passed string as a TLV element of the passed type
 * to the TLV chain.
 *
 */
faim_internal int aim_addtlvtochain_raw(aim_tlvlist_t **list, const fu16_t t, const fu16_t l, const fu8_t *v)
{
        aim_tlvlist_t *newtlv, *cur;

        if (!list)
                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())) {
                free(newtlv);
                return 0;
        }
        newtlv->tlv->type = t;
        if ((newtlv->tlv->length = l)) {
                newtlv->tlv->value = (fu8_t *)malloc(newtlv->tlv->length);
                memcpy(newtlv->tlv->value, v, newtlv->tlv->length);
        }

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

        return newtlv->tlv->length;
}

/**
 * aim_addtlvtochain8 - Add a 8bit integer to a TLV chain
 * @list: Destination chain
 * @type: TLV type to add
 * @val: Value to add
 *
 * Adds a one-byte unsigned integer to a TLV chain.
 *
 */
faim_internal int aim_addtlvtochain8(aim_tlvlist_t **list, const fu16_t t, const fu8_t v)
{
        fu8_t v8[1];

        aimutil_put8(v8, v);

        return aim_addtlvtochain_raw(list, t, 1, v8);
}

/**
 * aim_addtlvtochain16 - Add a 16bit integer to a TLV chain
 * @list: Destination chain
 * @type: TLV type to add
 * @val: Value to add
 *
 * Adds a two-byte unsigned integer to a TLV chain.
 *
 */
faim_internal int aim_addtlvtochain16(aim_tlvlist_t **list, const fu16_t t, const fu16_t v)
{
        fu8_t v16[2];

        aimutil_put16(v16, v);

        return aim_addtlvtochain_raw(list, t, 2, v16);
}

/**
 * aim_addtlvtochain32 - Add a 32bit integer to a TLV chain
 * @list: Destination chain
 * @type: TLV type to add
 * @val: Value to add
 *
 * Adds a four-byte unsigned integer to a TLV chain.
 *
 */
faim_internal int aim_addtlvtochain32(aim_tlvlist_t **list, const fu16_t t, const fu32_t v)
{
        fu8_t v32[4];

        aimutil_put32(v32, v);

        return aim_addtlvtochain_raw(list, t, 4, v32);
}

/**
 * aim_addtlvtochain_caps - Add a capability block to a TLV chain
 * @list: Destination chain
 * @type: TLV type to add
 * @caps: Bitfield of capability flags to send
 *
 * 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_VOICE       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
 *
 */
faim_internal int aim_addtlvtochain_caps(aim_tlvlist_t **list, const fu16_t t, 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_addtlvtochain_raw(list, t, aim_bstream_curpos(&bs), buf);
}

faim_internal int aim_addtlvtochain_userinfo(aim_tlvlist_t **list, fu16_t type, aim_userinfo_t *ui)
{
        fu8_t buf[1024]; /* bleh */
        aim_bstream_t bs;

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

        aim_putuserinfo(&bs, ui);

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

/**
 * aim_addtlvtochain_noval - Add a blank TLV to a TLV chain
 * @list: Destination chain
 * @type: TLV type to add
 *
 * Adds a TLV with a zero length to a TLV chain.
 *
 */
faim_internal int aim_addtlvtochain_noval(aim_tlvlist_t **list, const fu16_t t)
{
        return aim_addtlvtochain_raw(list, t, 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.
 *
 */
faim_internal int aim_addtlvtochain_frozentlvlist(aim_tlvlist_t **list, fu16_t type, aim_tlvlist_t **tl)
{
        fu8_t *buf;
        int buflen;
        aim_bstream_t bs;

        buflen = aim_sizetlvchain(tl);

        if (buflen <= 0)
                return 0;

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

        aim_bstream_init(&bs, buf, buflen);

        aim_writetlvchain(&bs, tl);

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

        free(buf);

        return buflen;
}

/**
 * aim_writetlvchain - Write a TLV chain into a data buffer.
 * @buf: Destination buffer
 * @buflen: Maximum number of bytes that will be written to buffer
 * @list: Source TLV chain
 *
 * Copies a TLV chain into a raw data buffer, writing only the number
 * of bytes specified. This operation does not free the chain; 
 * aim_freetlvchain() must still be called to free up the memory used
 * by the chain structures.
 *
 * XXX clean this up, make better use of bstreams 
 */
faim_internal int aim_writetlvchain(aim_bstream_t *bs, aim_tlvlist_t **list)
{
        int goodbuflen;
        aim_tlvlist_t *cur;

        /* do an initial run to test total length */
        for (cur = *list, goodbuflen = 0; cur; cur = cur->next) {
                goodbuflen += 2 + 2; /* type + len */
                goodbuflen += cur->tlv->length;
        }

        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 */
}


/**
 * aim_gettlv - Grab the Nth TLV of type type in the TLV list list.
 * @list: Source chain
 * @type: Requested TLV type
 * @nth: Index of TLV of type to get
 *
 * 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.
 *
 */
faim_internal aim_tlv_t *aim_gettlv(aim_tlvlist_t *list, const fu16_t t, const int n)
{
        aim_tlvlist_t *cur;
        int i;

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

        return NULL;
}

/**
 * aim_gettlv_str - Retrieve the Nth TLV in chain as a string.
 * @list: Source TLV chain
 * @type: TLV type to search for
 * @nth: Index of TLV to return
 *
 * Same as aim_gettlv(), except that the return value is a %NULL-
 * terminated string instead of an aim_tlv_t.  This is a 
 * dynamic buffer and must be freed by the caller.
 *
 */
faim_internal char *aim_gettlv_str(aim_tlvlist_t *list, const fu16_t t, const int n)
{
        aim_tlv_t *tlv;
        char *newstr;

        if (!(tlv = aim_gettlv(list, t, n)))
                return NULL;

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

        return newstr;
}

/**
 * aim_gettlv8 - Retrieve the Nth TLV in chain as a 8bit integer.
 * @list: Source TLV chain
 * @type: TLV type to search for
 * @nth: Index of TLV to return
 *
 * Same as aim_gettlv(), except that the return value is a 
 * 8bit integer instead of an aim_tlv_t. 
 *
 */
faim_internal fu8_t aim_gettlv8(aim_tlvlist_t *list, const fu16_t t, const int n)
{
        aim_tlv_t *tlv;

        if (!(tlv = aim_gettlv(list, t, n)))
                return 0; /* erm */
        return aimutil_get8(tlv->value);
}

/**
 * aim_gettlv16 - Retrieve the Nth TLV in chain as a 16bit integer.
 * @list: Source TLV chain
 * @type: TLV type to search for
 * @nth: Index of TLV to return
 *
 * Same as aim_gettlv(), except that the return value is a 
 * 16bit integer instead of an aim_tlv_t. 
 *
 */
faim_internal fu16_t aim_gettlv16(aim_tlvlist_t *list, const fu16_t t, const int n)
{
        aim_tlv_t *tlv;

        if (!(tlv = aim_gettlv(list, t, n)))
                return 0; /* erm */
        return aimutil_get16(tlv->value);
}

/**
 * aim_gettlv32 - Retrieve the Nth TLV in chain as a 32bit integer.
 * @list: Source TLV chain
 * @type: TLV type to search for
 * @nth: Index of TLV to return
 *
 * Same as aim_gettlv(), except that the return value is a 
 * 32bit integer instead of an aim_tlv_t. 
 *
 */
faim_internal fu32_t aim_gettlv32(aim_tlvlist_t *list, const fu16_t t, const int n)
{
        aim_tlv_t *tlv;

        if (!(tlv = aim_gettlv(list, t, n)))
                return 0; /* erm */
        return aimutil_get32(tlv->value);
}

#if 0
/**
 * aim_puttlv_8 - Write a one-byte TLV.
 * @buf: Destination buffer
 * @t: TLV type
 * @v: Value
 *
 * Writes a TLV with a one-byte integer value portion.
 *
 */
faim_export int aim_puttlv_8(fu8_t *buf, const fu16_t t, const fu8_t v)
{
        fu8_t v8[1];

        aimutil_put8(v8, v);

        return aim_puttlv_raw(buf, t, 1, v8);
}

/**
 * aim_puttlv_16 - Write a two-byte TLV.
 * @buf: Destination buffer
 * @t: TLV type
 * @v: Value
 *
 * Writes a TLV with a two-byte integer value portion.
 *
 */
faim_export int aim_puttlv_16(fu8_t *buf, const fu16_t t, const fu16_t v)
{
        fu8_t v16[2];

        aimutil_put16(v16, v);

        return aim_puttlv_raw(buf, t, 2, v16);
}


/**
 * aim_puttlv_32 - Write a four-byte TLV.
 * @buf: Destination buffer
 * @t: TLV type
 * @v: Value
 *
 * Writes a TLV with a four-byte integer value portion.
 *
 */
faim_export int aim_puttlv_32(fu8_t *buf, const fu16_t t, const fu32_t v)
{
        fu8_t v32[4];

        aimutil_put32(v32, v);

        return aim_puttlv_raw(buf, t, 4, v32);
}

/**
 * aim_puttlv_raw - Write a raw TLV.
 * @buf: Destination buffer
 * @t: TLV type
 * @l: Length of string
 * @v: String to write
 *
 * Writes a TLV with a raw value portion.  (Only the first @l
 * bytes of the passed buffer will be written, which should not
 * include a terminating NULL.)
 *
 */
faim_export int aim_puttlv_raw(fu8_t *buf, const fu16_t t, const fu16_t l, const fu8_t *v)
{
        int i;

        i = aimutil_put16(buf, t);
        i += aimutil_put16(buf+i, l);
        if (l)
                memcpy(buf+i, v, l);
        i += l;

        return i;
}
#endif