void * z_decomp_alloc (unsigned char * options, int opt_len);
The options pointer points to the a buffer containing the CCP option data for the compression being negotiated. It is formatted according to RFC1979, and describes the window size that we are requesting the peer to use in compressing data to be sent to us.
Returns the pointer to the private state for the decompressor, or NULL if we could not allocate enough memory.