This implements enough of the BSDI extensions to the net-2 ogetkerninfo()

syscall to allow applications linked against their libc's uname() to
work.  Netscape 1.1N being a prime example, which prints:
"uname() failed. cant tell what system we're running on".
This change is a little ugly, but that's mainly because of the "interesting"
semantics of the BSDI extension.
Since ogetkerninfo() is only enabled by COMPAT_43, Netscape will only
be affected on kernels with that option (eg: "GENERIC")
Reviewed by:	davidg

sys/kern/kern_sysctl.c

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_sysctl.c	8.4 (Berkeley) 4/14/94
- * $Id: kern_sysctl.c,v 1.24 1995/05/12 19:17:31 wollman Exp $
+ * $Id: kern_sysctl.c,v 1.25 1995/05/30 08:05:46 rgrimes Exp $
  */
 
 /*
@@ -767,6 +767,53 @@ fill_eproc(p, ep)
 #define	KINFO_LOADAVG		(5<<8)
 #define	KINFO_CLOCKRATE		(6<<8)
 
+/* Non-standard BSDI extension - only present on their 4.3 net-2 releases */
+#define	KINFO_BSDI_SYSINFO	(101<<8)
+
+/*
+ * XXX this is bloat, but I hope it's better here than on the potentially
+ * limited kernel stack...  -Peter
+ */
+
+struct {
+	int	bsdi_machine;		/* "i386" on BSD/386 */
+/*      ^^^ this is an offset to the string, relative to the struct start */
+	char	*pad0;
+	long	pad1;
+	long	pad2;
+	long	pad3;
+	u_long	pad4;
+	u_long	pad5;
+	u_long	pad6;
+
+	int	bsdi_ostype;		/* "BSD/386" on BSD/386 */
+	int	bsdi_osrelease;		/* "1.1" on BSD/386 */
+	long	pad7;
+	long	pad8;
+	char	*pad9;
+
+	long	pad10;
+	long	pad11;
+	int	pad12;
+	long	pad13;
+	quad_t	pad14;
+	long	pad15;
+
+	struct	timeval pad16;
+	/* we dont set this, because BSDI's uname used gethostname() instead */
+	int	bsdi_hostname;		/* hostname on BSD/386 */
+
+	/* the actual string data is appended here */
+
+} bsdi_si;
+/*
+ * this data is appended to the end of the bsdi_si structure during copyout.
+ * The "char *" offsets are relative to the base of the bsdi_si struct.
+ * This contains "FreeBSD\02.0-BUILT-nnnnnn\0i386\0", and these strings
+ * should not exceed the length of the buffer here... (or else!! :-)
+ */
+char bsdi_strings[80];	/* It had better be less than this! */
+
 struct getkerninfo_args {
 	int	op;
 	char	*where;
@@ -830,6 +877,70 @@ ogetkerninfo(p, uap, retval)
 		error = kern_sysctl(name, 1, uap->where, &size, NULL, 0, p);
 		break;
 
+	case KINFO_BSDI_SYSINFO: {
+		/*
+		 * this is pretty crude, but it's just enough for uname()
+		 * from BSDI's 1.x libc to work.
+		 *
+		 * In particular, it doesn't return the same results when
+		 * the supplied buffer is too small.  BSDI's version apparently
+		 * will return the amount copied, and set the *size to how
+		 * much was needed.  The emulation framework here isn't capable
+		 * of that, so we just set both to the amount copied.
+		 * BSDI's 2.x product apparently fails with ENOMEM in this
+		 * scenario.
+		 */
+
+		u_int needed;
+		u_int left;
+		char *s;
+
+		bzero((char *)&bsdi_si, sizeof(bsdi_si));
+		bzero(bsdi_strings, sizeof(bsdi_strings));
+
+		s = bsdi_strings;
+
+		bsdi_si.bsdi_ostype = (s - bsdi_strings) + sizeof(bsdi_si);
+		strcpy(s, ostype);
+		s += strlen(s) + 1;
+
+		bsdi_si.bsdi_osrelease = (s - bsdi_strings) + sizeof(bsdi_si);
+		strcpy(s, osrelease);
+		s += strlen(s) + 1;
+
+		bsdi_si.bsdi_machine = (s - bsdi_strings) + sizeof(bsdi_si);
+		strcpy(s, machine);
+		s += strlen(s) + 1;
+
+		needed = sizeof(bsdi_si) + (s - bsdi_strings);
+
+		if (uap->where == NULL) {
+			/* process is asking how much buffer to supply.. */
+			size = needed;
+			error = 0;
+			break;
+		}
+
+
+		/* if too much buffer supplied, trim it down */
+		if (size > needed)
+			size = needed;
+
+		/* how much of the buffer is remaining */
+		left = size;
+
+		if ((error = copyout((char *)&bsdi_si, uap->where, left)) != 0)
+			break;
+
+		/* is there any point in continuing? */
+		if (left > sizeof(bsdi_si)) {
+			left -= sizeof(bsdi_si);
+			error = copyout(&bsdi_strings,
+					uap->where + sizeof(bsdi_si), left);
+		}
+		break;
+	}
+
 	default:
 		return (EOPNOTSUPP);
 	}