Add link(2).

libc/Makefile

@@ -161,6 +161,7 @@ ioleast.o \
 isatty.o \
 kernelinfo.o \
 kill.o \
+link.o \
 localeconv.o \
 lseek.o \
 memstat.o \

libc/include/unistd.h

@@ -115,7 +115,6 @@ pid_t getpgrp(void);
 pid_t getsid(pid_t);
 uid_t getuid(void);
 int lchown(const char*, uid_t, gid_t);
-int link(const char*, const char*);
 int linkat(int, const char*, int, const char*, int);
 int lockf(int, int, off_t);
 int nice(int);
@@ -169,6 +168,7 @@ char* get_current_dir_name(void);
 pid_t getpid(void);
 pid_t getppid(void);
 int isatty(int);
+int link(const char*, const char*);
 off_t lseek(int, off_t, int);
 int pipe(int [2]);
 ssize_t pread(int, void*, size_t, off_t);

libc/link.cpp

@@ -0,0 +1,33 @@
+/*******************************************************************************
+
+    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/>.
+
+    link.cpp
+    Give a new name to a file.
+
+*******************************************************************************/
+
+#include <sys/syscall.h>
+#include <unistd.h>
+
+DEFN_SYSCALL2(int, sys_link, SYSCALL_LINK, const char*, const char*);
+
+extern "C" int link(const char* oldpath, const char* newpath)
+{
+	return sys_link(oldpath, newpath);
+}

sortix/include/sortix/syscallnum.h

@@ -80,6 +80,7 @@
 #define SYSCALL_FSTATAT 56
 #define SYSCALL_CHMOD 57
 #define SYSCALL_CHOWN 58
-#define SYSCALL_MAX_NUM 59 /* index of highest constant + 1 */
+#define SYSCALL_LINK 59
+#define SYSCALL_MAX_NUM 60 /* index of highest constant + 1 */
 
 #endif

sortix/io.cpp

@@ -349,6 +349,37 @@ static int sys_chmod(const char* path, mode_t mode)
 	return desc->chmod(&ctx, mode);
 }
 
+static int sys_link(const char* oldpath, const char* newpath)
+{
+	ioctx_t ctx; SetupUserIOCtx(&ctx);
+
+	char* newpathcopy = GetStringFromUser(newpath);
+	if ( !newpathcopy )
+		return -1;
+	const char* newrelpath = newpathcopy;
+	Ref<Descriptor> newfrom(PrepareLookup(&newrelpath));
+
+	char* final_elem;
+	Ref<Descriptor> dir = OpenDirContainingPath(&ctx, newfrom, newpathcopy,
+	                                            &final_elem);
+	delete[] newpathcopy;
+	if ( !dir )
+		return -1;
+
+	char* oldpathcopy = GetStringFromUser(oldpath);
+	if ( !oldpathcopy ) { delete[] final_elem; return -1; }
+	const char* oldrelpath = oldpathcopy;
+	Ref<Descriptor> oldfrom(PrepareLookup(&oldrelpath));
+
+	Ref<Descriptor> file = oldfrom->open(&ctx, oldrelpath, O_RDONLY);
+	delete[] oldpathcopy;
+	if ( !file ) { delete[] final_elem; return -1; }
+
+	int ret = dir->link(&ctx, final_elem, file);
+	delete[] final_elem;
+	return ret;
+}
+
 static int sys_settermmode(int fd, unsigned mode)
 {
 	Ref<Descriptor> desc = CurrentProcess()->GetDescriptor(fd);
@@ -399,6 +430,7 @@ void Init()
 	Syscall::Register(SYSCALL_FTRUNCATE, (void*) sys_ftruncate);
 	Syscall::Register(SYSCALL_GETTERMMODE, (void*) sys_gettermmode);
 	Syscall::Register(SYSCALL_ISATTY, (void*) sys_isatty);
+	Syscall::Register(SYSCALL_LINK, (void*) sys_link);
 	Syscall::Register(SYSCALL_MKDIR, (void*) sys_mkdir);
 	Syscall::Register(SYSCALL_OPENAT, (void*) sys_openat);
 	Syscall::Register(SYSCALL_OPEN, (void*) sys_open);