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>
18 #include <bits/kernel_types.h>
20 /* With newer versions of linux, the getdents syscall returns d_type
21 * information after the name field.
23 * See __ASSUME_GETDENTS32_D_TYPE in glibc's kernel-features.h for specific
24 * version / arch details.
28 # define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
35 unsigned short int d_reclen;
39 ssize_t __getdents (int fd, char *buf, size_t nbytes) attribute_hidden;
41 #define __NR___syscall_getdents __NR_getdents
42 static inline _syscall3(int, __syscall_getdents, int, fd, unsigned char *, kdirp, size_t, count);
44 #ifdef __ASSUME_GETDENTS32_D_TYPE
45 ssize_t __getdents (int fd, char *buf, size_t nbytes)
49 retval = __syscall_getdents(fd, (unsigned char *)buf, nbytes);
51 /* The kernel added the d_type value after the name. Change
55 struct kernel_dirent k;
57 } *kbuf = (void *) buf;
59 while ((char *) kbuf < buf + retval) {
60 char d_type = *((char *) kbuf + kbuf->k.d_reclen - 1);
61 memmove (kbuf->u.d_name, kbuf->k.d_name,
62 strlen (kbuf->k.d_name) + 1);
63 kbuf->u.d_type = d_type;
65 kbuf = (void *) ((char *) kbuf + kbuf->k.d_reclen);
72 #elif ! defined __UCLIBC_HAS_LFS__ || ! defined __NR_getdents64
74 /* Experimentally off - libc_hidden_proto(memcpy) */
75 libc_hidden_proto(lseek)
77 ssize_t __getdents (int fd, char *buf, size_t nbytes)
80 off_t last_offset = -1;
83 struct kernel_dirent *skdp, *kdp;
84 const size_t size_diff = (offsetof (struct dirent, d_name)
85 - offsetof (struct kernel_dirent, d_name));
87 red_nbytes = MIN (nbytes - ((nbytes /
88 (offsetof (struct dirent, d_name) + 14)) * size_diff),
91 dp = (struct dirent *) buf;
92 skdp = kdp = alloca (red_nbytes);
94 retval = __syscall_getdents(fd, (unsigned char *)kdp, red_nbytes);
98 while ((char *) kdp < (char *) skdp + retval) {
99 const size_t alignment = __alignof__ (struct dirent);
100 /* Since kdp->d_reclen is already aligned for the kernel structure
101 this may compute a value that is bigger than necessary. */
102 size_t new_reclen = ((kdp->d_reclen + size_diff + alignment - 1)
104 if ((char *) dp + new_reclen > buf + nbytes) {
105 /* Our heuristic failed. We read too many entries. Reset
107 assert (last_offset != -1);
108 lseek(fd, last_offset, SEEK_SET);
110 if ((char *) dp == buf) {
111 /* The buffer the user passed in is too small to hold even
113 __set_errno (EINVAL);
119 last_offset = kdp->d_off;
120 dp->d_ino = kdp->d_ino;
121 dp->d_off = kdp->d_off;
122 dp->d_reclen = new_reclen;
123 dp->d_type = DT_UNKNOWN;
124 memcpy (dp->d_name, kdp->d_name,
125 kdp->d_reclen - offsetof (struct kernel_dirent, d_name));
126 dp = (struct dirent *) ((char *) dp + new_reclen);
127 kdp = (struct kernel_dirent *) (((char *) kdp) + kdp->d_reclen);
129 return (char *) dp - buf;
132 #if defined __UCLIBC_HAS_LFS__ && ! defined __NR_getdents64
133 attribute_hidden strong_alias(__getdents,__getdents64)
136 #elif __WORDSIZE == 32
138 /* Experimentally off - libc_hidden_proto(memmove) */
140 extern __typeof(__getdents) __getdents64 attribute_hidden;
141 ssize_t __getdents (int fd, char *buf, size_t nbytes)
144 struct dirent64 *dp64;
145 ssize_t ret = __getdents64 (fd, buf, nbytes);
150 dp64 = (struct dirent64 *) buf;
152 while ((void *) dp64 < (void *) buf) {
153 dp = (struct dirent *) dp64;
154 dp->d_ino = dp64->d_ino;
155 dp->d_off = dp64->d_off;
156 dp->d_reclen = dp64->d_reclen;
157 dp->d_type = dp64->d_type;
158 memmove (dp->d_name, dp64->d_name, dp->d_reclen - offsetof (struct dirent64, d_name));
159 memmove (dp64, dp, dp->d_reclen);
160 dp64 = ((void *) dp64) + dp->d_reclen;