Kernel environment access, preloaded module lookup.

1 files changed, 144 insertions, 0 deletions

diff --git a/sys/kern/subr_module.c b/sys/kern/subr_module.c
new file mode 100644
index 0000000..91730f5
--- /dev/null
+++ b/sys/kern/subr_module.c
@@ -0,0 +1,144 @@
+/*-
+ * Copyright (c) 1998 Michael Smith
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$Id$
+ */
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/systm.h>
+#include <sys/linker.h>
+
+/*
+ * Preloaded module support
+ */
+
+caddr_t	module_metadata;
+
+/*
+ * Search for the preloaded module (name)
+ */
+caddr_t
+module_search_by_name(const char *name)
+{
+    caddr_t	curp;
+    u_int32_t	*hdr;
+    
+    if (module_metadata != NULL) {
+	
+	curp = module_metadata;
+	for (;;) {
+	    hdr = (u_int32_t *)curp;
+	    if (hdr[0] == 0)
+		break;
+
+	    /* Search for a MODINFO_NAME field */
+	    if ((hdr[0] == MODINFO_NAME) &&
+		!strcmp(name, curp + sizeof(u_int32_t) * 2))
+		return(curp);
+
+	    /* skip to next field */
+	    curp += sizeof(u_int32_t) * 2 + hdr[1];
+	}
+    }
+    return(NULL);
+}
+
+/*
+ * Search for the first preloaded module of (type)
+ */
+caddr_t
+module_search_by_type(const char *type)
+{
+    caddr_t	curp, lname;
+    u_int32_t	*hdr;
+
+    if (module_metadata != NULL) {
+
+	curp = module_metadata;
+	lname = NULL;
+	for (;;) {
+	    hdr = (u_int32_t *)curp;
+	    if (hdr[0] == 0)
+		break;
+
+	    /* remember the start of each record */
+	    if (hdr[0] == MODINFO_NAME)
+		lname = curp;
+
+	    /* Search for a MODINFO_TYPE field */
+	    if ((hdr[0] == MODINFO_TYPE) &&
+		!strcmp(type, curp + sizeof(u_int32_t) * 2))
+		return(lname);
+
+	    /* skip to next field */
+	    curp += sizeof(u_int32_t) * 2 + hdr[1];
+	}
+    }
+    return(NULL);
+}
+
+/*
+ * Given a preloaded module handle (mod), return a pointer
+ * to the data for the attribute (inf).
+ */
+caddr_t
+module_search_info(caddr_t mod, int inf)
+{
+    caddr_t	curp;
+    u_int32_t	*hdr;
+    u_int32_t	type = 0;
+
+    curp = mod;
+    for (;;) {
+	hdr = (u_int32_t *)curp;
+	/* end of module data? */
+	if (hdr[0] == 0)
+	    break;
+	/* 
+	 * We give up once we've looped back to what we were looking at 
+	 * first - this should normally be a MODINFO_NAME field.
+	 */
+	if (type == 0) {
+	    type = hdr[0];
+	} else {
+	    if (hdr[0] == type)
+		break;
+	}
+	
+	/* 
+	 * Attribute match? Return pointer to data.
+	 * Consumer may safely assume that size value preceeds	
+	 * data.
+	 */
+	if (hdr[0] == inf)
+	    return(curp + (sizeof(u_int32_t) * 2));
+
+	/* skip to next field */
+	curp += sizeof(u_int32_t) * 2 + hdr[1];
+    }
+    return(NULL);
+}
+