/* * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org> * * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball. */ #include <features.h> #include <alloca.h> #include <assert.h> #include <errno.h> #include <dirent.h> #include <stddef.h> #include <stdint.h> #include <string.h> #include <unistd.h> #include <sys/param.h> #include <sys/types.h> #include <sys/syscall.h> #include <bits/kernel_types.h> #if defined __UCLIBC_HAS_LFS__ && defined __NR_getdents64 # ifndef offsetof # define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) # endif struct kernel_dirent64 { uint64_t d_ino; int64_t d_off; unsigned short d_reclen; unsigned char d_type; char d_name[256]; }; # define __NR___syscall_getdents64 __NR_getdents64 static __inline__ _syscall3(int, __syscall_getdents64, int, fd, unsigned char *, dirp, size_t, count) ssize_t __getdents64 (int fd, char *buf, size_t nbytes) attribute_hidden; ssize_t __getdents64 (int fd, char *buf, size_t nbytes) { struct dirent64 *dp; off64_t last_offset = -1; ssize_t retval; size_t red_nbytes; struct kernel_dirent64 *skdp, *kdp; const size_t size_diff = (offsetof (struct dirent64, d_name) - offsetof (struct kernel_dirent64, d_name)); red_nbytes = MIN (nbytes - ((nbytes / (offsetof (struct dirent64, d_name) + 14)) * size_diff), nbytes - size_diff); dp = (struct dirent64 *) buf; skdp = kdp = alloca (red_nbytes); retval = __syscall_getdents64(fd, (unsigned char *)kdp, red_nbytes); if (retval == -1) return -1; while ((char *) kdp < (char *) skdp + retval) { const size_t alignment = __alignof__ (struct dirent64); /* Since kdp->d_reclen is already aligned for the kernel structure this may compute a value that is bigger than necessary. */ size_t new_reclen = ((kdp->d_reclen + size_diff + alignment - 1) & ~(alignment - 1)); if ((char *) dp + new_reclen > buf + nbytes) { /* Our heuristic failed. We read too many entries. Reset the stream. */ assert (last_offset != -1); lseek64(fd, last_offset, SEEK_SET); if ((char *) dp == buf) { /* The buffer the user passed in is too small to hold even one entry. */ __set_errno (EINVAL); return -1; } break; } last_offset = kdp->d_off; dp->d_ino = kdp->d_ino; dp->d_off = kdp->d_off; dp->d_reclen = new_reclen; dp->d_type = kdp->d_type; memcpy (dp->d_name, kdp->d_name, kdp->d_reclen - offsetof (struct kernel_dirent64, d_name)); dp = (struct dirent64 *) ((char *) dp + new_reclen); kdp = (struct kernel_dirent64 *) (((char *) kdp) + kdp->d_reclen); } return (char *) dp - buf; } #if __WORDSIZE == 64 /* since getdents doesnt give us d_type but getdents64 does, try and * use getdents64 as much as possible */ attribute_hidden strong_alias(__getdents64,__getdents) #endif #endif