usr.bin: Add 'sysctl' program

Signed-off-by: Ian Moffett <ian@osmora.org>

3 files changed, 146 insertions, 0 deletions

diff --git a/usr.bin/Makefile b/usr.bin/Makefile
index d8bf421..47ba752 100644
--- a/usr.bin/Makefile
+++ b/usr.bin/Makefile
@@ -26,3 +26,4 @@ all:
 	make -C oasm/ $(ARGS)
 	make -C oemu/ $(ARGS)
 	make -C dmidump/ $(ARGS)
+	make -C sysctl/ $(ARGS)
diff --git a/usr.bin/sysctl/Makefile b/usr.bin/sysctl/Makefile
new file mode 100644
index 0000000..e32dbc4
--- /dev/null
+++ b/usr.bin/sysctl/Makefile
@@ -0,0 +1,6 @@
+include user.mk
+
+CFILES = $(shell find . -name "*.c")
+
+$(ROOT)/base/usr/bin/sysctl:
+	gcc $(CFILES) -o $@ $(INTERNAL_CFLAGS)
diff --git a/usr.bin/sysctl/sysctl.c b/usr.bin/sysctl/sysctl.c
new file mode 100644
index 0000000..a23bfe8
--- /dev/null
+++ b/usr.bin/sysctl/sysctl.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * 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.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
+ */
+
+#include <sys/sysctl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#define NAME_OSTYPE         "ostype"
+#define NAME_OSRELEASE      "osrelease"
+#define NAME_VERSION        "version"
+#define NAME_VCACHE_TYPE    "vcache_type"
+
+/*
+ * Convert string name to a sysctl name
+ * definition.
+ *
+ * @name: Name to convert
+ *
+ *                Convert to int def
+ *               /
+ *    kern.ostype
+ *         ^^ name
+ *
+ *  --
+ *  Returns a less than zero value on failure
+ *  (e.g., entry not found).
+ */
+static int
+name_to_def(const char *name)
+{
+    switch (*name) {
+    case 'v':
+        if (strcmp(name, NAME_VERSION) == 0) {
+            return KERN_VERSION;
+        }
+
+        if (strcmp(name, NAME_VCACHE_TYPE) == 0) {
+            return KERN_VCACHE_TYPE;
+        }
+
+        return -1;
+    case 'o':
+        if (strcmp(name, NAME_OSTYPE) == 0) {
+            return KERN_OSTYPE;
+        }
+
+        if (strcmp(name, NAME_OSRELEASE) == 0) {
+            return KERN_OSRELEASE;
+        }
+
+        return -1;
+    }
+
+    return -1;
+}
+
+int
+main(int argc, char **argv)
+{
+    struct sysctl_args args;
+    char *var, *p;
+    int type, name, error;
+    size_t oldlen;
+    char buf[128];
+
+    if (argc < 2) {
+        printf("sysctl: usage: sysctl <var>\n");
+        return -1;
+    }
+
+    var = argv[1];
+    p = strtok(var, ".");
+
+    if (p == NULL) {
+        printf("sysctl: bad var\n");
+        return -1;
+    }
+
+    /* TODO: Non kern.* vars */
+    if (strcmp(p, "kern") != 0) {
+        printf("unknown var \"%s\"\n", p);
+        return -1;
+    }
+
+    p = strtok(NULL, ".");
+    if (p == NULL) {
+        printf("sysctl: bad var \"%s\"\n", p);
+        return -1;
+    }
+
+    if ((name = name_to_def(p)) < 0) {
+        printf("sysctl: bad var \"%s\"\n", p);
+        return name;
+    }
+
+    name = name;
+    oldlen = sizeof(buf);
+    args.name = &name;
+    args.nlen = 1;
+    args.oldp = buf;
+    args.oldlenp = &oldlen;
+    args.newp = NULL;
+    args.newlen = 0;
+
+    if ((error = sysctl(&args)) != 0) {
+        printf("sysctl returned %d\n", error);
+        return error;
+    }
+
+    printf("%s\n", buf);
+    return 0;
+}