linux32/common/linux32_sysctl.c

/*        $NetBSD: linux32_sysctl.c,v 1.19 2020/03/21 16:28:56 pgoyette Exp $ */

/*-
 * Copyright (c) 2006 Emmanuel Dreyfus, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by Emmanuel Dreyfus
 * 4. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE 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.
 */
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux32_sysctl.c,v 1.19 2020/03/21 16:28:56 pgoyette Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/sysctl.h>
#include <sys/syscallargs.h>
#include <sys/ktrace.h>

#include <compat/netbsd32/netbsd32.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_sysctl.h>
#include <compat/linux/common/linux_ipc.h>
#include <compat/linux/common/linux_sem.h>
#include <compat/linux/linux_syscallargs.h>

#include <compat/linux32/common/linux32_types.h>
#include <compat/linux32/common/linux32_signal.h>
#include <compat/linux32/common/linux32_sysctl.h>
#include <compat/linux32/linux32_syscallargs.h>

char linux32_sysname[128] = "Linux";
char linux32_release[128] = "3.11.6";
char linux32_version[128] = "#1 SMP PREEMPT Thu Oct 24 16:23:02 UTC 2013";

struct sysctlnode linux32_sysctl_root = {
          .sysctl_flags = SYSCTL_VERSION|
              CTLFLAG_ROOT|CTLTYPE_NODE|CTLFLAG_READWRITE,
          .sysctl_num = 0,
          .sysctl_name = "(linux32_root)",
          .sysctl_size = sizeof(struct sysctlnode),
};

extern int linux32_enabled;

/*
 * We need our own sysctllog here because we deal with two
 * separate sysctl trees;  each clog is restricted to a
 * single tree.
 */

static struct sysctllog *linux32_clog;

void
linux32_sysctl_fini(void)
{

          sysctl_teardown(&linux32_clog);
          sysctl_free(&linux32_sysctl_root);
}

SYSCTL_SETUP(linux32_sysctl_init, "linux32 emulation sysctls")
{
          const struct sysctlnode *node = &linux32_sysctl_root;

          sysctl_createv(clog, 0, NULL, NULL,
                           CTLFLAG_PERMANENT,
                           CTLTYPE_NODE, "linux32",
                           SYSCTL_DESCR("Linux 32 bit emulation settings"),
                           NULL, 0, NULL, 0,
                           CTL_EMUL, EMUL_LINUX32, CTL_EOL);
          sysctl_createv(clog, 0, NULL, NULL,
                           CTLFLAG_PERMANENT,
                           CTLTYPE_NODE, "kern",
                           SYSCTL_DESCR("Linux 32 bit kernel emulation settings"),
                           NULL, 0, NULL, 0,
                           CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN, CTL_EOL);

          sysctl_createv(clog, 0, NULL, NULL,
                           CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                           CTLTYPE_STRING, "ostype",
                           SYSCTL_DESCR("Linux 32 bit operating system type"),
                           NULL, 0, linux32_sysname, sizeof(linux32_sysname),
                           CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN,
                           EMUL_LINUX32_KERN_OSTYPE, CTL_EOL);
          sysctl_createv(clog, 0, NULL, NULL,
                           CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                           CTLTYPE_STRING, "osrelease",
                           SYSCTL_DESCR("Linux 32 bit operating system release"),
                           NULL, 0, linux32_release, sizeof(linux32_release),
                           CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN,
                           EMUL_LINUX32_KERN_OSRELEASE, CTL_EOL);
          sysctl_createv(clog, 0, NULL, NULL,
                           CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                           CTLTYPE_STRING, "osversion",
                           SYSCTL_DESCR("Linux 32 bit operating system revision"),
                           NULL, 0, linux32_version, sizeof(linux32_version),
                           CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN,
                           EMUL_LINUX32_KERN_VERSION, CTL_EOL);
          sysctl_createv(clog, 0, NULL, NULL,
                           CTLFLAG_READWRITE,
                           CTLTYPE_INT, "enabled",
                           SYSCTL_DESCR("Linux 32 bit compat enabled."),
                           linux32_sysctl_enable, 0, &linux32_enabled, 0,
                           CTL_EMUL, EMUL_LINUX32, CTL_CREATE, CTL_EOL);

          sysctl_createv(&linux32_clog, 0, &node, &node,
                           CTLFLAG_PERMANENT,
                           CTLTYPE_NODE, "kern", NULL,
                           NULL, 0, NULL, 0,
                           LINUX_CTL_KERN, CTL_EOL);

          sysctl_createv(&linux32_clog, 0, &node, NULL,
                           CTLFLAG_PERMANENT,
                           CTLTYPE_STRING, "ostype", NULL,
                           NULL, 0, linux32_sysname, sizeof(linux32_sysname),
                           LINUX_KERN_OSTYPE, CTL_EOL);
          sysctl_createv(&linux32_clog, 0, &node, NULL,
                           CTLFLAG_PERMANENT,
                           CTLTYPE_STRING, "osrelease", NULL,
                           NULL, 0, linux32_release, sizeof(linux32_release),
                           LINUX_KERN_OSRELEASE, CTL_EOL);
          sysctl_createv(&linux32_clog, 0, &node, NULL,
                           CTLFLAG_PERMANENT,
                           CTLTYPE_STRING, "version", NULL,
                           NULL, 0, linux32_version, sizeof(linux32_version),
                           LINUX_KERN_VERSION, CTL_EOL);

          linux32_sysctl_root.sysctl_flags &= ~CTLFLAG_READWRITE;
}

int
linux32_sys___sysctl(struct lwp *l, const struct linux32_sys___sysctl_args *uap, register_t *retval)
{
          /* {
                    syscallarg(linux32___sysctlp_t) lsp;
          } */
          struct linux32_sysctl ls32;
          int name[CTL_MAXNAME];
          size_t savelen;
          netbsd32_size_t oldlen32;
          size_t oldlen;
          int error;

          /*
           * Read sysctl arguments
           */
          if ((error = copyin(SCARG_P32(uap, lsp), &ls32, sizeof(ls32))) != 0)
                    return error;

          /*
           * Read oldlen
           */
          if (NETBSD32PTR64(ls32.oldlenp) != NULL) {
                    if ((error = copyin(NETBSD32PTR64(ls32.oldlenp),
                        &oldlen32, sizeof(oldlen32))) != 0)
                              return error;
          } else {
                    oldlen32 = 0;
          }

          savelen = (size_t)oldlen32;

          /*
           * Sanity check nlen
           */
          if ((ls32.nlen > CTL_MAXNAME) || (ls32.nlen < 1))
                    return ENOTDIR;

          /*
           * Read the sysctl name
           */
          if ((error = copyin(NETBSD32PTR64(ls32.name), &name,
             ls32.nlen * sizeof(int))) != 0)
                    return error;

          ktrmib(name, ls32.nlen);
          /*
           * First try linux32 tree, then linux tree
           */
          oldlen = (size_t)oldlen32;
          sysctl_lock(NETBSD32PTR64(ls32.newval) != NULL);
          error = sysctl_dispatch(name, ls32.nlen,
                                        NETBSD32PTR64(ls32.oldval), &oldlen,
                                        NETBSD32PTR64(ls32.newval), ls32.newlen,
                                        name, l, &linux32_sysctl_root);
          oldlen32 = (netbsd32_size_t)oldlen;
          sysctl_unlock();

          /*
           * Check for oldlen overflow (not likely, but who knows...)
           */
          if (oldlen != oldlen32) {
#ifdef DEBUG_LINUX
                    printf("%s: oldlen32 = %d, oldlen = %ld\n",
                        __func__, oldlen32, oldlen);
#endif
                    return EINVAL;
          }

          /*
           * set caller's oldlen, even if we got an error
           */
          if (NETBSD32PTR64(ls32.oldlenp)) {
                    int nerror;

                    nerror = copyout(&oldlen32,
                        NETBSD32PTR64(ls32.oldlenp), sizeof(oldlen32));

                    if (error == 0)
                              error = nerror;
          }

          /*
           * oldlen was too short
           */
          if ((error == 0) &&
              (NETBSD32PTR64(ls32.oldval) != NULL) &&
              (savelen < oldlen32))
                    error = ENOMEM;

          return error;
}