Using smbget to download files recursively (-R). 

If smbget found that a file is already existed in the destination, 
smbget would said 'File exists', return early, and 'newname' allocated 
memory is never freed, this is found by valgrind.

patch will follow.

# valgrind --leak-check=full --show-leak-kinds=definite smbget -R -U${ac}%${pw} smb://${ip}/src
==13050== Memcheck, a memory error detector
==13050== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==13050== Using Valgrind-3.12.0 and LibVEX; rerun with -h for copyright info
==13050== Command: smbget -R -Ujones%${pw} smb://127.0.0.1/src
==13050==
Using workgroup WORKGROUP, user jones
Can't open file: File exists
Failed to download /file: File exists
==13050==
==13050== HEAP SUMMARY:
==13050==     in use at exit: 121,424 bytes in 263 blocks
==13050==   total heap usage: 5,466 allocs, 5,203 frees, 927,883 bytes allocated
==13050==
==13050== 6 bytes in 1 blocks are definitely lost in loss record 6 of 151
==13050==    at 0x4C28B15: malloc (in /root/bin/valgrind-3.12.0/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==13050==    by 0x5B7E9D7: vasprintf (vasprintf.c:76)
==13050==    by 0x5B5D2C6: asprintf (asprintf.c:35)
==13050==    by 0x10BC29: smb_download_dir (smbget.c:211)
==13050==    by 0x10A549: main (smbget.c:1037)
==13050==
... <cut> ...