Regarding QNX structures

I need help in replacing Linux sk_buff structure (declared
inlinux/sk_buff.h) to equivalent structure. does anybody have knowledge of
what structure and functions should I use for the same. I need to allocate
the buffer in ISR. linux provides dev_alloc_skb (uses alloc_skb with
GFP_ATOMIC flag) that makes it safe to use in ISR for memory allocation as
it is atomic and does not cause calling process to sleep. I want to know the
equivalents in QNX

Thanks in advance