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>
19 #include <bits/kernel-features.h>
21 #if !(defined __UCLIBC_HAS_LFS__ && defined __NR_getdents64 && __WORDSIZE == 64)
22 /* If the condition above is met, __getdents is defined as an alias
23 * for __getdents64 (see getdents64.c). Otherwise...
26 /* With newer versions of linux, the getdents syscall returns d_type
27 * information after the name field.
29 * See __ASSUME_GETDENTS32_D_TYPE in glibc's kernel-features.h for specific
30 * version / arch details.
34 # define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
41 unsigned short int d_reclen;
45 ssize_t __getdents (int fd, char *buf, size_t nbytes) attribute_hidden;
47 #define __NR___syscall_getdents __NR_getdents
48 static __always_inline _syscall3(int, __syscall_getdents, int, fd, unsigned char *, kdirp, size_t, count)
50 #if defined __ASSUME_GETDENTS32_D_TYPE
52 ssize_t __getdents (int fd, char *buf, size_t nbytes)
56 retval = __syscall_getdents(fd, (unsigned char *)buf, nbytes);
58 /* The kernel added the d_type value after the name. Change
62 struct kernel_dirent k;
64 } *kbuf = (void *) buf;
66 while ((char *) kbuf < buf + retval) {
67 char d_type = *((char *) kbuf + kbuf->k.d_reclen - 1);
68 memmove (kbuf->u.d_name, kbuf->k.d_name,
69 strlen (kbuf->k.d_name) + 1);
70 kbuf->u.d_type = d_type;
72 kbuf = (void *) ((char *) kbuf + kbuf->k.d_reclen);
79 #elif ! defined __UCLIBC_HAS_LFS__ || ! defined __NR_getdents64
81 ssize_t __getdents (int fd, char *buf, size_t nbytes)
84 off_t last_offset = -1;
87 struct kernel_dirent *skdp, *kdp;
88 const size_t size_diff = (offsetof (struct dirent, d_name)
89 - offsetof (struct kernel_dirent, d_name));
91 red_nbytes = MIN (nbytes - ((nbytes /
92 (offsetof (struct dirent, d_name) + 14)) * size_diff),
95 dp = (struct dirent *) buf;
96 skdp = kdp = alloca (red_nbytes);
98 retval = __syscall_getdents(fd, (unsigned char *)kdp, red_nbytes);
102 while ((char *) kdp < (char *) skdp + retval) {
103 const size_t alignment = __alignof__ (struct dirent);
104 /* Since kdp->d_reclen is already aligned for the kernel structure
105 this may compute a value that is bigger than necessary. */
106 size_t new_reclen = ((kdp->d_reclen + size_diff + alignment - 1)
108 if ((char *) dp + new_reclen > buf + nbytes) {
109 /* Our heuristic failed. We read too many entries. Reset
111 assert (last_offset != -1);
112 lseek(fd, last_offset, SEEK_SET);
114 if ((char *) dp == buf) {
115 /* The buffer the user passed in is too small to hold even
117 __set_errno (EINVAL);
123 last_offset = kdp->d_off;
124 dp->d_ino = kdp->d_ino;
125 dp->d_off = kdp->d_off;
126 dp->d_reclen = new_reclen;
127 dp->d_type = DT_UNKNOWN;
128 memcpy (dp->d_name, kdp->d_name,
129 kdp->d_reclen - offsetof (struct kernel_dirent, d_name));
130 dp = (struct dirent *) ((char *) dp + new_reclen);
131 kdp = (struct kernel_dirent *) (((char *) kdp) + kdp->d_reclen);
133 return (char *) dp - buf;
136 #if defined __UCLIBC_HAS_LFS__ && ! defined __NR_getdents64
137 attribute_hidden strong_alias(__getdents,__getdents64)
140 #elif __WORDSIZE == 32
142 extern __typeof(__getdents) __getdents64 attribute_hidden;
143 ssize_t __getdents (int fd, char *buf, size_t nbytes)
146 struct dirent64 *dp64;
147 ssize_t ret = __getdents64 (fd, buf, nbytes);
152 dp64 = (struct dirent64 *) buf;
154 while ((void *) dp64 < (void *) buf) {
155 dp = (struct dirent *) dp64;
156 dp->d_ino = dp64->d_ino;
157 dp->d_off = dp64->d_off;
158 dp->d_reclen = dp64->d_reclen;
159 dp->d_type = dp64->d_type;
160 memmove (dp->d_name, dp64->d_name, dp->d_reclen - offsetof (struct dirent64, d_name));
161 memmove (dp64, dp, dp->d_reclen);
162 dp64 = ((void *) dp64) + dp->d_reclen;