Add faccessat(2).

libc/Makefile

@@ -138,6 +138,7 @@ execvp.o \
 _exit.o \
 _Exit.o \
 exit.o \
+faccessat.o \
 fchmod.o \
 fcloseall.o \
 fcntl.o \

libc/faccessat.cpp

@@ -0,0 +1,34 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2012.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    faccessat.cpp
+    Check real user's permissions for a file
+
+*******************************************************************************/
+
+#include <sys/syscall.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+DEFN_SYSCALL4(int, sys_faccessat, SYSCALL_FACCESSAT, int, const char*, int, int);
+
+extern "C" int faccessat(int dirfd, const char* path, int mode, int flags)
+{
+	return sys_faccessat(dirfd, path, mode, flags);
+}

libc/include/unistd.h

@@ -92,7 +92,6 @@ size_t confstr(int, char*, size_t);
 char* crypt(const char*, const char*);
 char* ctermid(char*);
 void encrypt(char [64], int);
-int faccessat(int, const char*, int, int);
 int fchdir(int);
 int fchown(int, uid_t, gid_t);
 int fchownat(int, const char*, uid_t, gid_t, int);
@@ -161,6 +160,7 @@ int execv(const char*, char* const []);
 int execve(const char*, char* const [], char* const []);
 int execvp(const char*, char* const []);
 pid_t fork(void);
+int faccessat(int, const char*, int, int);
 int ftruncate(int, off_t);
 char* getcwd(char*, size_t);
 char* get_current_dir_name(void);

sortix/include/sortix/fcntl.h

@@ -56,6 +56,8 @@ __BEGIN_DECLS
 
 #define AT_FDCWD (-100)
 #define AT_REMOVEDIR (1<<0)
+#define AT_EACCESS (1<<1)
+#define AT_SYMLINK_NOFOLLOW (1<<2)
 
 __END_DECLS
 

sortix/include/sortix/syscallnum.h

@@ -83,6 +83,7 @@
 #define SYSCALL_LINK 59
 #define SYSCALL_DUP2 60
 #define SYSCALL_UNLINKAT 61
-#define SYSCALL_MAX_NUM 62 /* index of highest constant + 1 */
+#define SYSCALL_FACCESSAT 62
+#define SYSCALL_MAX_NUM 63 /* index of highest constant + 1 */
 
 #endif

sortix/io.cpp

@@ -158,19 +158,27 @@ static int sys_open(const char* path, int flags, mode_t mode)
 }
 
 // TODO: This is a hack! Stat the file in some manner and check permissions.
-static int sys_access(const char* path, int /*mode*/)
+static int sys_faccessat(int dirfd, const char* path, int /*mode*/, int flags)
 {
+	if ( flags )
+		return errno = ENOSYS, -1;
 	char* pathcopy = GetStringFromUser(path);
 	if ( !pathcopy )
 		return -1;
 	ioctx_t ctx; SetupUserIOCtx(&ctx);
 	const char* relpath = pathcopy;
-	Ref<Descriptor> from = PrepareLookup(&relpath);
+	Ref<Descriptor> from = PrepareLookup(&relpath, dirfd);
+	if ( !from ) { delete[] pathcopy; return -1; }
 	Ref<Descriptor> desc = from->open(&ctx, relpath, O_RDONLY);
 	delete[] pathcopy;
 	return desc ? 0 : -1;
 }
 
+static int sys_access(const char* path, int mode)
+{
+	return sys_faccessat(AT_FDCWD, path, mode, 0);
+}
+
 static int sys_unlinkat(int dirfd, const char* path, int flags)
 {
 	char* pathcopy = GetStringFromUser(path);
@@ -429,6 +437,7 @@ void Init()
 	Syscall::Register(SYSCALL_CLOSE, (void*) sys_close);
 	Syscall::Register(SYSCALL_DUP, (void*) sys_dup);
 	Syscall::Register(SYSCALL_DUP2, (void*) sys_dup2);
+	Syscall::Register(SYSCALL_FACCESSAT, (void*) sys_faccessat);
 	Syscall::Register(SYSCALL_FCNTL, (void*) sys_fcntl);
 	Syscall::Register(SYSCALL_FSTATAT, (void*) sys_fstatat);
 	Syscall::Register(SYSCALL_FSTAT, (void*) sys_fstat);