bsdinstall: ssh lockout protection

[allanjude]

Summary

Remind the user to add a user to the wheel group if they enable SSH.
SSH login as root is disabled by default, if no user is added to the wheel
group then it will not be possible to su to root.

[eadler]

usr.sbin/bsdinstall/scripts/auto

452

quotes

usr.sbin/bsdinstall/scripts/wheelinvite

38

nit: add quotes around these vars

[dteske]

usr.sbin/bsdinstall/scripts/auto

450

Opening brace on next line plz

453

[ "$WHEEL_MEMBERS" = "wheel:*:0:root" ] || return

Allows you to reduce the level indentation

455

[ "$SSH_ENABLE" = YES ] || return

Allows you to reduce the level indentation

456

Not needed.

Line 34 reads:
f_include $BSDCFG_SHARE/dialog.subr

In dialog.subr, line 2182 in f_dialog_init() function reads:
eval exec $DIALOG_TERMINAL_PASSTHRU_FD\>\&1

For reference, line 47 of dialog.subr reads:
: ${DIALOG_TERMINAL_PASSTHRU_FD:=${TERMINAL_STDOUT_PASSTHRU:-3}}

And finally, lines 2334 to 2337 of dialog.subr read:
case "$DIALOG_SELF_INITIALIZE" in
""|0|[Nn][Oo]|[Oo][Ff][Ff]|[Ff][Aa][Ll][Ss][Ee]) : do nothing ;;
*) f_dialog_init
esac

And for reference, line 91 of dialog.subr reads:
: ${DIALOG_SELF_INITIALIZE=1}

So when you include dialog.subr, unless you have set DIALOG_SELF_INITIALIZE to NULL, 0, NO, Off, or False (all case insensitive), file descriptor 3 (the default unless you modify either TERMINAL_STDOUT_PASSTHRU or DIALOG_TERMINAL_PASSTHRU_FD) is already dup'd to the active stdout for sub-shells to use.

Action-item: remove this line.

457

WHEEL_QUESTION=$( $DIALOG \

--backtitle "FreeBSD Installer" \

Use $DIALOG not dialog. Put all options on own for diff reduction should options change.

458

Move --no-cancel to own line. Move --menu to own line.

459

Don't rely on auto-sizing, use f_dialog_menu_size() from dialog.subr to get an appropriately sized dialog. See wlanconfig in same directory for example.

462

The "1" in "1>3" is unnecessary. Also, best to use the predefined variable for the pre-created file descriptor (below):

2>&1 >&$DIALOG_TERMINAL_PASSTHRU_FD

463

Do not close this file descriptor. In a future release when the namespace is conflated, this will do harm to the other modules that expect this file descriptor to be active.

Action item: remove this line.

472

wheelinvite should be dialog based

475

Switch to fallback.

*) # Continue anyway

483–485

f_interactive && check_wheel

usr.sbin/bsdinstall/scripts/wheelinvite

29–35

Why not dialog based?