/* mmap() replacement for Windows * * Author: Mike Frysinger <vapier@gentoo.org> * Placed into the public domain */ /* References: * CreateFileMapping: http://msdn.microsoft.com/en-us/library/aa366537(VS.85).aspx * CloseHandle: http://msdn.microsoft.com/en-us/library/ms724211(VS.85).aspx * MapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366761(VS.85).aspx * UnmapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366882(VS.85).aspx */ #include <io.h> #include <windows.h> #include <sys/types.h> #define PROT_READ 0x1 #define PROT_WRITE 0x2 /* This flag is only available in WinXP+ */ #ifdef FILE_MAP_EXECUTE #define PROT_EXEC 0x4 #else #define PROT_EXEC 0x0 #define FILE_MAP_EXECUTE 0 #endif #define MAP_SHARED 0x01 #define MAP_PRIVATE 0x02 #define MAP_ANONYMOUS 0x20 #define MAP_ANON MAP_ANONYMOUS #define MAP_FAILED ((void *) -1) #ifdef __USE_FILE_OFFSET64 # define DWORD_HI(x) (x >> 32) # define DWORD_LO(x) ((x) & 0xffffffff) #else # define DWORD_HI(x) (0) # define DWORD_LO(x) (x) #endif static void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset) { if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)) return MAP_FAILED; if (fd == -1) { if (!(flags & MAP_ANON) || offset) return MAP_FAILED; } else if (flags & MAP_ANON) return MAP_FAILED; DWORD flProtect; if (prot & PROT_WRITE) { if (prot & PROT_EXEC) flProtect = PAGE_EXECUTE_READWRITE; else flProtect = PAGE_READWRITE; } else if (prot & PROT_EXEC) { if (prot & PROT_READ) flProtect = PAGE_EXECUTE_READ; else if (prot & PROT_EXEC) flProtect = PAGE_EXECUTE; } else flProtect = PAGE_READONLY; off_t end = length + offset; HANDLE mmap_fd, h; if (fd == -1) mmap_fd = INVALID_HANDLE_VALUE; else mmap_fd = (HANDLE)_get_osfhandle(fd); h = CreateFileMapping(mmap_fd, NULL, flProtect, DWORD_HI(end), DWORD_LO(end), NULL); if (h == NULL) return MAP_FAILED; DWORD dwDesiredAccess; if (prot & PROT_WRITE) dwDesiredAccess = FILE_MAP_WRITE; else dwDesiredAccess = FILE_MAP_READ; if (prot & PROT_EXEC) dwDesiredAccess |= FILE_MAP_EXECUTE; if (flags & MAP_PRIVATE) dwDesiredAccess |= FILE_MAP_COPY; void *ret = MapViewOfFile(h, dwDesiredAccess, DWORD_HI(offset), DWORD_LO(offset), length); if (ret == NULL) { CloseHandle(h); ret = MAP_FAILED; } return ret; } static void munmap(void *addr, size_t length) { UnmapViewOfFile(addr); /* ruh-ro, we leaked handle from CreateFileMapping() ... */ } #undef DWORD_HI #undef DWORD_LO