Enable ioctl() in the "rw" request, to support FIONREAD/FIONBIO easier

for the stdio/libevent usage case.  Further ioctl commands are narrowly
checked as before.
ok djm guenther semarie

diff --git a/sys/kern/kern_tame.c b/sys/kern/kern_tame.c
index fcd30e6..0b0f095 100644 (file)
--- a/sys/kern/kern_tame.c
+++ b/sys/kern/kern_tame.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_tame.c,v 1.57 2015/10/04 17:55:21 deraadt Exp $  */
+/*     $OpenBSD: kern_tame.c,v 1.58 2015/10/06 05:42:12 deraadt Exp $  */
 
 /*
  * Copyright (c) 2015 Nicholas Marriott <nicm@openbsd.org>
@@ -140,7 +140,8 @@ const u_int tame_syscalls[SYS_MAXSYSCALL] = {
        [SYS_setresgid] = TAME_PROC,
        [SYS_setresuid] = TAME_PROC,
 
-       [SYS_ioctl] = TAME_IOCTL,               /* very limited subset */
+       /* FIONREAD/FIONBIO, plus further checks in tame_ioctl_check() */
+       [SYS_ioctl] = TAME_RW | TAME_IOCTL,
 
        [SYS_getentropy] = TAME_MALLOC,
        [SYS_madvise] = TAME_MALLOC,
@@ -974,78 +975,65 @@ tame_ioctl_check(struct proc *p, long com, void *v)
        if ((p->p_p->ps_flags & PS_TAMED) == 0)
                return (0);
 
-       if (fp == NULL)
-               return (EBADF);
-       vp = (struct vnode *)fp->f_data;
-
-       switch (com) {
-
        /*
-        * This is a set of "get" info ioctls at the top layer.  Hopefully
-        * a safe list, since they are used a lot.
+        * The ioctl's which are always allowed.
         */
-       case FIOCLEX:
-       case FIONCLEX:
+       switch (com) {
        case FIONREAD:
        case FIONBIO:
-       case FIOGETOWN:
                return (0);
-       case FIOASYNC:
-       case FIOSETOWN:
-               return (EPERM);
-
-       /* tty subsystem */
-       case TIOCGETA:
-       case TIOCGPGRP:
-       case TIOCGWINSZ:        /* various programs */
-       case TIOCSTI:           /* ksh? csh? */
-               if (fp->f_type == DTYPE_VNODE && (vp->v_flag & VISTTY))
-                       return (0);
-               break;
-
-       default:
-               break;
        }
 
-       if ((p->p_p->ps_tame & TAME_IOCTL) == 0)
-               return (EPERM);
+       if (fp == NULL)
+               return (EBADF);
+       vp = (struct vnode *)fp->f_data;
 
        /*
         * Further sets of ioctl become available, but are checked a
         * bit more carefully against the vnode.
         */
-
-       switch (com) {
-       case BIOCGSTATS:        /* bpf: tcpdump privsep on ^C */
-               if (fp->f_type == DTYPE_VNODE &&
-                   fp->f_ops->fo_ioctl == vn_ioctl)
+       if ((p->p_p->ps_tame & TAME_IOCTL)) {
+               switch (com) {
+               case FIOCLEX:
+               case FIONCLEX:
+               case FIOASYNC:
+               case FIOSETOWN:
+               case FIOGETOWN:
                        return (0);
-               break;
-
-       case TIOCSETAF:         /* tcsetattr TCSAFLUSH, script */
-               if (fp->f_type == DTYPE_VNODE && (vp->v_flag & VISTTY))
-                       return (0);
-               break;
-
-
-       case MTIOCGET:
-       case MTIOCTOP:
-               /* for pax(1) and such, checking tapes... */
-               if (fp->f_type == DTYPE_VNODE &&
-                   (vp->v_type == VCHR || vp->v_type == VBLK))
-                       return (0);
-               break;
-
-       case SIOCGIFGROUP:
-               if ((p->p_p->ps_tame & TAME_INET) &&
-                   fp->f_type == DTYPE_SOCKET)
-                       return (0);
-               break;
-
-       default:
-               printf("tame: ioctl %lx\n", com);
-               break;
+               case TIOCGETA:
+               case TIOCGPGRP:
+               case TIOCGWINSZ:        /* various programs */
+               case TIOCSTI:           /* ksh? csh? */
+               case TIOCSBRK:          /* cu */
+               case TIOCCDTR:          /* cu */
+                       if (fp->f_type == DTYPE_VNODE && (vp->v_flag & VISTTY))
+                               return (0);
+                       break;
+               case BIOCGSTATS:        /* bpf: tcpdump privsep on ^C */
+                       if (fp->f_type == DTYPE_VNODE &&
+                           fp->f_ops->fo_ioctl == vn_ioctl)
+                               return (0);
+                       break;
+               case TIOCSETAF:         /* tcsetattr TCSAFLUSH, script */
+                       if (fp->f_type == DTYPE_VNODE && (vp->v_flag & VISTTY))
+                               return (0);
+                       break;
+               case MTIOCGET:
+               case MTIOCTOP:
+                       /* for pax(1) and such, checking tapes... */
+                       if (fp->f_type == DTYPE_VNODE &&
+                           (vp->v_type == VCHR || vp->v_type == VBLK))
+                               return (0);
+                       break;
+               case SIOCGIFGROUP:
+                       if ((p->p_p->ps_tame & TAME_INET) &&
+                           fp->f_type == DTYPE_SOCKET)
+                               return (0);
+                       break;
+               }
        }
+
+       printf("tame: ioctl %lx\n", com);
        return (EPERM);
 }