Add O_PATH support for flistxattr()
A continuation of commit 2825f10b7f61558c264231a536cf3affc0d84204.
Add O_PATH compatibility support for flistxattr(). This allows
a process to list out all the extended attributes associated with
O_PATH file descriptors.
Change-Id: Ie2285ac7ad2e4eac427ddba6c2d182d41b130f75
diff --git a/libc/Android.mk b/libc/Android.mk
index 620f438..868d159 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -130,6 +130,7 @@
bionic/fchmodat.cpp \
bionic/ffs.cpp \
bionic/fgetxattr.cpp \
+ bionic/flistxattr.cpp \
bionic/flockfile.cpp \
bionic/fpclassify.cpp \
bionic/fsetxattr.cpp \
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 4890b89..23cc3b6 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -124,7 +124,7 @@
void sync(void) all
int ___fsetxattr:fsetxattr(int, const char*, const void*, size_t, int) all
ssize_t ___fgetxattr:fgetxattr(int, const char*, void*, size_t) all
-ssize_t flistxattr(int, char*, size_t) all
+ssize_t ___flistxattr:flistxattr(int, char*, size_t) all
int fremovexattr(int, const char*) all
int __getdents64:getdents64(unsigned int, struct dirent*, unsigned int) arm,arm64,mips,mips64,x86,x86_64
diff --git a/libc/arch-arm/syscalls/flistxattr.S b/libc/arch-arm/syscalls/___flistxattr.S
similarity index 81%
rename from libc/arch-arm/syscalls/flistxattr.S
rename to libc/arch-arm/syscalls/___flistxattr.S
index ee09295..8ae8b7e 100644
--- a/libc/arch-arm/syscalls/flistxattr.S
+++ b/libc/arch-arm/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
mov ip, r7
ldr r7, =__NR_flistxattr
swi #0
@@ -11,4 +11,5 @@
bxls lr
neg r0, r0
b __set_errno_internal
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-arm64/syscalls/flistxattr.S b/libc/arch-arm64/syscalls/___flistxattr.S
similarity index 78%
rename from libc/arch-arm64/syscalls/flistxattr.S
rename to libc/arch-arm64/syscalls/___flistxattr.S
index 8921bb4..02c8478 100644
--- a/libc/arch-arm64/syscalls/flistxattr.S
+++ b/libc/arch-arm64/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
mov x8, __NR_flistxattr
svc #0
@@ -11,4 +11,5 @@
b.hi __set_errno_internal
ret
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-mips/syscalls/flistxattr.S b/libc/arch-mips/syscalls/___flistxattr.S
similarity index 81%
rename from libc/arch-mips/syscalls/flistxattr.S
rename to libc/arch-mips/syscalls/___flistxattr.S
index 0b71532..5a4a53d 100644
--- a/libc/arch-mips/syscalls/flistxattr.S
+++ b/libc/arch-mips/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
.set noreorder
.cpload t9
li v0, __NR_flistxattr
@@ -16,4 +16,5 @@
j t9
nop
.set reorder
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-mips64/syscalls/flistxattr.S b/libc/arch-mips64/syscalls/___flistxattr.S
similarity index 85%
rename from libc/arch-mips64/syscalls/flistxattr.S
rename to libc/arch-mips64/syscalls/___flistxattr.S
index 1d5b1b0..586bcf7 100644
--- a/libc/arch-mips64/syscalls/flistxattr.S
+++ b/libc/arch-mips64/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
.set push
.set noreorder
li v0, __NR_flistxattr
@@ -22,4 +22,5 @@
j t9
move ra, t0
.set pop
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-x86/syscalls/flistxattr.S b/libc/arch-x86/syscalls/___flistxattr.S
similarity index 90%
rename from libc/arch-x86/syscalls/flistxattr.S
rename to libc/arch-x86/syscalls/___flistxattr.S
index fc81a37..a67967b 100644
--- a/libc/arch-x86/syscalls/flistxattr.S
+++ b/libc/arch-x86/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
pushl %ebx
.cfi_def_cfa_offset 8
.cfi_rel_offset ebx, 0
@@ -28,4 +28,5 @@
popl %ecx
popl %ebx
ret
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-x86_64/syscalls/flistxattr.S b/libc/arch-x86_64/syscalls/___flistxattr.S
similarity index 80%
rename from libc/arch-x86_64/syscalls/flistxattr.S
rename to libc/arch-x86_64/syscalls/___flistxattr.S
index aa02db1..b4695cc 100644
--- a/libc/arch-x86_64/syscalls/flistxattr.S
+++ b/libc/arch-x86_64/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
movl $__NR_flistxattr, %eax
syscall
cmpq $-MAX_ERRNO, %rax
@@ -12,4 +12,5 @@
call __set_errno_internal
1:
ret
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/bionic/flistxattr.cpp b/libc/bionic/flistxattr.cpp
new file mode 100644
index 0000000..05a96d2
--- /dev/null
+++ b/libc/bionic/flistxattr.cpp
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/xattr.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+
+extern "C" ssize_t ___flistxattr(int, char*, size_t);
+
+ssize_t flistxattr(int fd, char *list, size_t size) {
+ int saved_errno = errno;
+ ssize_t result = ___flistxattr(fd, list, size);
+
+ if ((result != -1) || (errno != EBADF)) {
+ return result;
+ }
+
+ // fd could be an O_PATH file descriptor, and the kernel
+ // may not directly support fgetxattr() on such a file descriptor.
+ // Use /proc/self/fd instead to emulate this support.
+ int fd_flag = fcntl(fd, F_GETFL);
+ if ((fd_flag == -1) || ((fd_flag & O_PATH) == 0)) {
+ errno = EBADF;
+ return -1;
+ }
+
+ char buf[40];
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
+ errno = saved_errno;
+ return listxattr(buf, list, size);
+}
diff --git a/tests/sys_xattr_test.cpp b/tests/sys_xattr_test.cpp
index 1842682..113ec26 100644
--- a/tests/sys_xattr_test.cpp
+++ b/tests/sys_xattr_test.cpp
@@ -80,6 +80,7 @@
ASSERT_EQ(-1, res);
ASSERT_EQ(EBADF, errno);
#endif
+ close(fd);
}
TEST(sys_xattr, fsetxattr_with_opath_toosmall) {
@@ -97,4 +98,32 @@
ASSERT_EQ(-1, res);
ASSERT_EQ(EBADF, errno);
#endif
+ close(fd);
+}
+
+TEST(sys_xattr, flistattr) {
+ TemporaryFile tf;
+ char buf[65536]; // 64kB is max possible xattr list size. See "man 7 xattr".
+ ASSERT_EQ(0, fsetxattr(tf.fd, "user.foo", "bar", 4, 0));
+ ssize_t result = flistxattr(tf.fd, buf, sizeof(buf));
+ ASSERT_TRUE(result >= 9);
+ ASSERT_TRUE(memmem(buf, sizeof(buf), "user.foo", 9) != NULL);
+}
+
+TEST(sys_xattr, flistattr_opath) {
+ TemporaryFile tf;
+ char buf[65536]; // 64kB is max possible xattr list size. See "man 7 xattr".
+ ASSERT_EQ(0, fsetxattr(tf.fd, "user.foo", "bar", 4, 0));
+ int fd = open(tf.filename, O_PATH);
+ ASSERT_NE(-1, fd);
+ ssize_t res = flistxattr(fd, buf, sizeof(buf));
+#if defined(__BIONIC__)
+ ASSERT_TRUE(res >= 9);
+ ASSERT_TRUE(static_cast<size_t>(res) <= sizeof(buf));
+ ASSERT_TRUE(memmem(buf, res, "user.foo", 9) != NULL);
+#else
+ ASSERT_EQ(-1, res);
+ ASSERT_EQ(EBADF, errno);
+#endif
+ close(fd);
}
