Re: install.sub: ieee80211_{scan,config}: Allow quoted SSIDs

[Klemens Nanni]

On Mon, Jul 03, 2017 at 12:45:32AM +0200, Klemens Nanni wrote:

Thanks for looking into it.

On Sun, Jul 02, 2017 at 04:32:43PM +0000, Robert Peichaer wrote:

ieee80211_scan()
- Extract the needed information (nwid, bssid) using a very specific
  sed expression. Any line, not matching this expr is ignored.

- Remove leading and trailing double-quotes in case of nwids with
  spaces.

I had the ugly case of an empty SSID in reach while testing this so I
intentionally left double quotes in place within WLANLIST so that
the list presented to the user wouldn't look broken, e.g.
        "my wifi" chan 1 bssid ...
        "" chan 2 bssid ...
as opposed to
        my wifi chan 1 bssid ...
         chan 2 bssid ...

I'd also leave unqouting to the routine that actually requires it
instead of the function that just provides the list.

- Write nwid and bssid into WLANLIST as '<nwid><space>(<bssid>)'.

Writing the simple format directly to cache seems like a good idea
instead of just cutting ^nwid first here and .*$ somewhere else.

ieee80211_config()
- just print WLANLIST using ieee80211_scan() if the user chooses
  '?' which has the right format already

- in case the user selects an entry from WLANLIST using a number,
  remove the '<space>(<bssid>)' part from the line, resulting in
  the nwid (without double-quotes)

- using the quote() function with the ifconfig command ensures,
  that the nwid is quoted properly with single-quotes in case it
  contains spaces

This is not needed as "$_nwid" will even work if _nwid='my "wifi'.

- using the quote() function when writing the nwid to the hostname.if
  files ensures that the nwid is quoted properly with single-quotes
  in case it contains spaces

The parse_hn_line() function in netstart does handle quoted nwids
properly when processing the hostname.if config lines as far as I
can see.

Yes, it does. But it chokes on SSIDs containing a literal " for example.


Here is an updated diff taking above considerations into account.

Note how ([[:xdigit:]:]*)$ when picking the answer must not be
simplified to (.*)$ as this would fail on SSIDs like "my (hidden) wifi".

Feedback/OK?

That patch was mangled, sorry. Here it goes again.

Index: install.sub
===================================================================
RCS file: /cvs/src/distrib/miniroot/install.sub,v
retrieving revision 1.1019
diff -u -p -r1.1019 install.sub
--- install.sub 2 Jul 2017 12:45:43 -0000       1.1019
+++ install.sub 4 Jul 2017 20:43:56 -0000
@@ -1060,10 +1060,9 @@ v6_config() {
# Perform an 802.11 network scan on interface $1.
# The result is cached in $WLANLIST.
ieee80211_scan() {
-       # N.B. Skipping quoted nwid's for now.
        [[ -f $WLANLIST ]] ||
                ifconfig $1 scan |
-               sed -n 's/^             nwid \([^"]\)/\1/p' >$WLANLIST
+                       sed -n 's/^[[:space:]]*nwid \(.*\) chan [0-9]* bssid 
\([[:xdigit:]:]*\).*/\1 (\2)/p' >$WLANLIST
        cat $WLANLIST
}

@@ -1082,12 +1081,12 @@ ieee80211_config() {
                ask_until "Access point? (ESSID, 'any', list# or '?')" "any"
                case "$resp" in
                +([0-9]))
-                       _nwid=$(ieee80211_scan $_if | sed -n "${resp}s/ .*//p")
+                       _nwid=$(ieee80211_scan $_if |
+                               sed -n ${resp}'{s/ ([[:xdigit:]:]*)$//p;q;}')
                        [[ -z $_nwid ]] && echo "There is no line $resp."
+                       [[ $_nwid = \"*\" ]] && _nwid=${_nwid#\"} 
_nwid=${_nwid%\"}
                        ;;
-               \?)     ieee80211_scan $_if |
-                               sed -n 's/^\([^ ]*\) chan .* bssid \([^ ]*\) 
.*$/       \1 (\2)/p' |
-                               cat -n | more -c
+               \?)     ieee80211_scan $_if | cat -n | more -c
                        ;;
                *)      _nwid=$resp
                        ;;