1 files changed, 137 insertions, 0 deletions
diff --git a/usr/src/lib/brand/lx/lx_brand/common/sysctl.c b/usr/src/lib/brand/lx/lx_brand/common/sysctl.c
new file mode 100644
index 0000000000..262a9c3830
--- /dev/null
+++ b/usr/src/lib/brand/lx/lx_brand/common/sysctl.c
@@ -0,0 +1,137 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ * Copyright 2014 Joyent, Inc.  All rights reserved.
+ */
+
+#include <alloca.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/lx_syscall.h>
+#include <sys/lx_misc.h>
+#include <sys/lx_debug.h>
+
+/*
+ * sysctl() implementation.  The full set of possible values is incredibly
+ * large; we only implement the bare minimum here, namely basic kernel
+ * information.
+ *
+ * For the moment, we also print out debugging messages if the application
+ * attempts to write or access any other values, so we can tell if we are not
+ * supporting something we should be.
+ */
+
+struct lx_sysctl_args {
+	int *name;
+	int nlen;
+	void *oldval;
+	size_t *oldlenp;
+	void *newval;
+	size_t newlen;
+};
+
+#define	LX_CTL_KERN		1
+
+#define	LX_KERN_OSTYPE		1
+#define	LX_KERN_OSRELEASE	2
+#define	LX_KERN_OSREV		3
+#define	LX_KERN_VERSION		4
+
+long
+lx_sysctl(uintptr_t raw)
+{
+	struct lx_sysctl_args args;
+	int name[2];
+	size_t oldlen;
+	char *namebuf;
+
+	if (uucopy((void *)raw, &args, sizeof (args)) < 0)
+		return (-EFAULT);
+
+	/*
+	 * We only allow [ CTL_KERN, KERN_* ] pairs, so reject anything that
+	 * doesn't have exactly two values starting with LX_CTL_KERN.
+	 */
+	if (args.nlen != 2)
+		return (-ENOTDIR);
+
+	if (uucopy(args.name, name, sizeof (name)) < 0)
+		return (-EFAULT);
+
+	if (name[0] != LX_CTL_KERN) {
+		lx_debug("sysctl: read of [%d, %d] unsupported",
+		    name[0], name[1]);
+		return (-ENOTDIR);
+	}
+
+	/* We don't support writing new sysctl values. */
+	if ((args.newval != NULL) || (args.newlen != 0)) {
+		lx_debug("sysctl: write of [%d, %d] unsupported",
+		    name[0], name[1]);
+		return (-EPERM);
+	}
+
+	/*
+	 * It may seem silly, but passing in a NULL oldval pointer and not
+	 * writing any new values is a perfectly legal thing to do and should
+	 * succeed.
+	 */
+	if (args.oldval == NULL)
+		return (0);
+
+	/*
+	 * Likewise, Linux specifies that setting a non-NULL oldval but a
+	 * zero *oldlenp should result in an errno of EFAULT.
+	 */
+	if ((uucopy(args.oldlenp, &oldlen, sizeof (oldlen)) < 0) ||
+	    (oldlen == 0))
+		return (-EFAULT);
+
+	namebuf = SAFE_ALLOCA(oldlen);
+	if (namebuf == NULL)
+		return (-ENOMEM);
+
+	switch (name[1]) {
+	case LX_KERN_OSTYPE:
+		(void) strlcpy(namebuf, LX_UNAME_SYSNAME, oldlen);
+		break;
+	case LX_KERN_OSRELEASE:
+		(void) strlcpy(namebuf, lx_release, oldlen);
+		break;
+	case LX_KERN_VERSION:
+		(void) strlcpy(namebuf, LX_UNAME_VERSION, oldlen);
+		break;
+	default:
+		lx_debug("sysctl: read of [CTL_KERN, %d] unsupported", name[1]);
+		return (-ENOTDIR);
+	}
+
+	oldlen = strlen(namebuf);
+
+	if ((uucopy(namebuf, args.oldval, oldlen) < 0) ||
+	    (uucopy(&oldlen, args.oldlenp, sizeof (oldlen)) < 0))
+		return (-EFAULT);
+
+	return (0);
+}