I've been able to locate the .text section of the module, knowing the base address of that section and its size how would I be able to find the other segments of the DLL, like .rdata, .data, .bss, etc. 
Finding other segments of a manually mapped DLL having found the .text segment
dll
You'll make 2 assumptions: all virtual memory allocations are done with 4k (0x1000) incremental.text section will (in most cases) be places after the PE headerSo, your goal would be to find the DLL's PE header and parse it to find all the parameters of the other sections, assuming they are present. Using above assumptions, you would:Decrement your known base address by 0x1000Check that this new address is valid (i.e VirtualQuery)Check for presence of MZ signature starting the address from (1)If found, parse the header and you can calculate the offsets based on the header data - you already know where .text located, extrapolate for other sections the same way.Repeat for reasonable amount of times till you find the header.