syscalls: linkat

kernel-src/sys/syscalls/linkat.c

@@ -0,0 +1,61 @@
+#include <kernel/syscalls.h>
+#include <kernel/alloc.h>
+
+
+syscallret_t syscall_linkat(context_t *, int olddirfd, const char *uoldpath, int newdirfd, const char *unewpath, int flags, int type) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	char *oldpath = alloc(strlen(uoldpath) + 1);
+	if (oldpath == NULL) {
+		ret.errno = ENOMEM;
+		return ret;
+	}
+
+	char *newpath = alloc(strlen(unewpath) + 1);
+	if (newpath == NULL) {
+		free(oldpath);
+		ret.errno = ENOMEM;
+		return ret;
+	}
+
+	// TODO safe strcopy
+	strcpy(oldpath, uoldpath);
+	strcpy(newpath, unewpath);
+
+	vnode_t *olddirnode = NULL;
+	file_t *oldfile = NULL;
+	vnode_t *newdirnode = NULL;
+	file_t *newfile = NULL;
+	ret.errno = dirfd_enter(oldpath, olddirfd, &oldfile, &olddirnode);
+
+	if (ret.errno)
+		goto cleanup;
+
+	ret.errno = dirfd_enter(newpath, newdirfd, &newfile, &newdirnode);
+
+	if (ret.errno)
+		goto cleanup;
+
+	vattr_t attr = {
+		.gid = _cpu()->thread->proc->cred.gid,
+		.uid = _cpu()->thread->proc->cred.uid
+	};
+
+	ret.errno = vfs_link(olddirnode, oldpath, newdirnode, newpath, type == 0 ? V_TYPE_REGULAR : V_TYPE_LINK, &attr);
+	ret.ret = ret.errno ? -1 : 0;
+
+	cleanup:
+
+	if (olddirnode)
+		dirfd_leave(olddirnode, oldfile);
+
+	if (newdirnode)
+		dirfd_leave(newdirnode, newfile);
+
+	free(oldpath);
+	free(newpath);
+
+	return ret;
+}