kernel: syscall: Add SYS_sysctl syscall

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

4 files changed, 94 insertions, 0 deletions

diff --git a/sys/include/sys/syscall.h b/sys/include/sys/syscall.h
index b9e1d09..e93c0ce 100644
--- a/sys/include/sys/syscall.h
+++ b/sys/include/sys/syscall.h
@@ -41,6 +41,7 @@
 #define SYS_read    3
 #define SYS_close   4
 #define SYS_stat    5
+#define SYS_sysctl  6
 
 #if defined(_KERNEL)
 /* Syscall return value and arg type */
diff --git a/sys/include/sys/sysctl.h b/sys/include/sys/sysctl.h
index 364d8e5..0f1df26 100644
--- a/sys/include/sys/sysctl.h
+++ b/sys/include/sys/sysctl.h
@@ -31,6 +31,9 @@
 #define _SYS_SYSCTL_H_
 
 #include <sys/types.h>
+#if defined(_KERNEL)
+#include <sys/syscall.h>
+#endif
 #include <sys/param.h>
 
 #define KERN_OSTYPE         0
@@ -55,6 +58,8 @@ struct sysctl_entry {
     int optype;
     void *data;
 };
+
+scret_t sys_sysctl(struct syscall_args *scargs);
 #endif  /* _KERNEL */
 
 /*
diff --git a/sys/kern/kern_syscall.c b/sys/kern/kern_syscall.c
index f4d9cb8..2d3d6ea 100644
--- a/sys/kern/kern_syscall.c
+++ b/sys/kern/kern_syscall.c
@@ -28,6 +28,7 @@
  */
 
 #include <sys/syscall.h>
+#include <sys/sysctl.h>
 #include <sys/types.h>
 #include <sys/proc.h>
 #include <sys/vfs.h>
@@ -39,6 +40,7 @@ scret_t(*g_sctab[])(struct syscall_args *) = {
     sys_read,   /* SYS_read */
     sys_close,  /* SYS_close */
     sys_stat,   /* SYS_stat */
+    sys_sysctl, /* SYS_sysctl */
 };
 
 const size_t MAX_SYSCALLS = NELEM(g_sctab);
diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index 970bc70..3d0b118 100644
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -28,7 +28,9 @@
  */
 
 #include <sys/sysctl.h>
+#include <sys/syscall.h>
 #include <sys/errno.h>
+#include <sys/systm.h>
 #include <vm/dynalloc.h>
 #include <string.h>
 
@@ -46,6 +48,76 @@ static struct sysctl_entry common_kerntab[] = {
     [KERN_VERSION] = { KERN_VERSION, SYSCTL_OPTYPE_STR, &hyra_version },
 };
 
+/*
+ * Helper for sys_sysctl()
+ */
+static int
+do_sysctl(struct sysctl_args *args)
+{
+    struct sysctl_args new_args;
+    size_t name_len, oldlenp;
+    int *name = NULL;
+    void *oldp = NULL, *newp = NULL;
+    int retval = 0;
+
+    if (args->oldlenp == NULL) {
+        return -EINVAL;
+    }
+
+    name_len = args->nlen;
+    retval = copyin(args->oldlenp, &oldlenp, sizeof(oldlenp));
+    if (retval != 0) {
+        goto done;
+    }
+
+    /* Copy in newp if it is set */
+    if (args->newp == NULL) {
+        newp = NULL;
+    } else {
+        newp = dynalloc(args->newlen);
+        retval = copyin(args->newp, newp, args->newlen);
+    }
+
+    if (retval != 0) {
+        goto done;
+    }
+
+    name = dynalloc(name_len * sizeof(int));
+    retval = copyin(args->name, name, name_len * sizeof(int));
+    if (retval != 0) {
+        return retval;
+    }
+
+    oldp = dynalloc(oldlenp);
+    retval = copyin(args->oldp, oldp, oldlenp);
+    if (retval != 0) {
+        return retval;
+    }
+
+    /* Prepare the arguments for the sysctl call */
+    new_args.name = name;
+    new_args.nlen = name_len;
+    new_args.oldp = oldp;
+    new_args.oldlenp = &oldlenp;
+    new_args.newp = newp;
+
+    retval = sysctl(&new_args);
+    if (retval != 0) {
+        goto done;
+    }
+
+    copyout(oldp, args->oldp, oldlenp);
+done:
+    if (name != NULL)
+        dynfree(name);
+    if (newp != NULL)
+        dynfree(newp);
+    if (oldp != NULL)
+        dynfree(oldp);
+
+    return retval;
+}
+
 int
 sysctl(struct sysctl_args *args)
 {
@@ -96,3 +168,17 @@ sysctl(struct sysctl_args *args)
     memcpy(args->oldp, tmp_str, oldlen);
     return (len > oldlen) ? -ENOMEM : 0;
 }
+
+scret_t
+sys_sysctl(struct syscall_args *scargs)
+{
+    struct sysctl_args args;
+    int error;
+
+    error = copyin((void *)scargs->arg0, &args, sizeof(args));
+    if (error != 0) {
+        return error;
+    }
+
+    return do_sysctl(&args);
+}