2 * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
4 * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
15 #include <sys/param.h>
16 #include <sys/types.h>
17 #include <sys/syscall.h>
19 libc_hidden_proto(memcpy)
20 libc_hidden_proto(lseek)
23 # define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
30 unsigned short d_reclen;
34 #define __NR___syscall_getdents __NR_getdents
35 static inline _syscall3(int, __syscall_getdents, int, fd, unsigned char *, kdirp, size_t, count);
37 ssize_t attribute_hidden __getdents (int fd, char *buf, size_t nbytes);
38 ssize_t attribute_hidden __getdents (int fd, char *buf, size_t nbytes)
41 off_t last_offset = -1;
44 struct kernel_dirent *skdp, *kdp;
45 const size_t size_diff = (offsetof (struct dirent, d_name)
46 - offsetof (struct kernel_dirent, d_name));
48 red_nbytes = MIN (nbytes - ((nbytes /
49 (offsetof (struct dirent, d_name) + 14)) * size_diff),
52 dp = (struct dirent *) buf;
53 skdp = kdp = alloca (red_nbytes);
55 retval = __syscall_getdents(fd, (char *)kdp, red_nbytes);
59 while ((char *) kdp < (char *) skdp + retval) {
60 const size_t alignment = __alignof__ (struct dirent);
61 /* Since kdp->d_reclen is already aligned for the kernel structure
62 this may compute a value that is bigger than necessary. */
63 size_t new_reclen = ((kdp->d_reclen + size_diff + alignment - 1)
65 if ((char *) dp + new_reclen > buf + nbytes) {
66 /* Our heuristic failed. We read too many entries. Reset
68 assert (last_offset != -1);
69 lseek(fd, last_offset, SEEK_SET);
71 if ((char *) dp == buf) {
72 /* The buffer the user passed in is too small to hold even
80 last_offset = kdp->d_off;
81 dp->d_ino = kdp->d_ino;
82 dp->d_off = kdp->d_off;
83 dp->d_reclen = new_reclen;
84 dp->d_type = DT_UNKNOWN;
85 memcpy (dp->d_name, kdp->d_name,
86 kdp->d_reclen - offsetof (struct kernel_dirent, d_name));
87 dp = (struct dirent *) ((char *) dp + new_reclen);
88 kdp = (struct kernel_dirent *) (((char *) kdp) + kdp->d_reclen);
90 return (char *) dp - buf;