crosh: Permit SSH-ing to IPv6 addresses.

bin/crosh

 #!/bin/dash
 # Copyright (c) 2009-2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 TRY_BASH=1
 if echo "$@" | grep -q -- "--dash"; then
   TRY_BASH=0
 fi
 
 # NOTE: This script *almost* works in dash.  Unfortunately, dash is missing
 # the 'history' builtin and readline support is missing from the 'read'
 # builtin.
 #
 # Please test that any changes continue to work in dash by running
 # '/build/board-name/bin/dash crosh --dash' before checking them in.
 
 if type "history" 2>/dev/null | grep -q "shell builtin"; then
   IS_BASH=1
 else
   IS_BASH=0
 fi
 
-# The terminal seems to come up with a bogus notion of its geometry.  Calling
-# reset works around the problem.
-reset

[Daniel Erat, 2011/01/28 22:36:53]

This shouldn't be needed now that we're using rxvt-unicode instead of aterm or
xterm.

[rginda, 2011/02/02 23:07:43]

Cool, that reset took forever.

-
 if [ "$TRY_BASH" = "1" -a "$IS_BASH" != "1" -a -x "/bin/bash" ]; then
   # Relaunch in bash if we can.
   exec /bin/bash $0 "$@"
 fi
 
 #
 # Please keep the help text in alphabetical order!
 #
 HELP='
  enterprise_ca_approve [--allow-self-signed] <url>
   Approve an enterprise certificate authority.  The <url> option should be
   an http or https url to your enterprise Certificate Authority in PEM
   format.  This CA will be used to validate the signature of an enterprise
   policy extension.
 
   If the --allow-self-signed option is provided, then you may provide a self
   signed CA.  Use this only if you are certain of the source of the CA.
 
  enterprise_ca_disapprove
   Remove a previously approved enterprise certificate authority.
- 
+
  exit
   Exit crosh.
 
  ff_debug [<tag_expr>] [--help] [--list_valid_tags] [--reset]
   Add and remove flimflam debugging tags.
 
  help
   Display this help.
 
  modem <command> [args...]
   Interact with the 3G modem. Run "modem help" for detailed help.
 
  network_logging <wifi | cellular | ethernet>
-  A function that enables a predefined set of tags useful for 
+  A function that enables a predefined set of tags useful for
   debugging the specified device.
 
  network_diag
   A function that performs a suite of network diagnostics.  Saves a copy
   of the output to your download directory.
 
  ping [-c count] [-i interval] [-n] [-s packet-size] [-W wait-time] <destination>
   Send ICMP ECHO_REQUEST packets to a network host.  If <destination> is "gw"
   then the next hop gateway for the default route is used.
 
@@ skipping 96 matching lines @@
     echo "Missing required parameter: user"
     return
   elif ! check_username "$user"; then
     echo "Invalid user: $user"
     return
   fi
 
   if [ -z "$host" ]; then
     echo "Missing required parameter: host"
     return
-  elif ! check_hostname "$host"; then
+  elif ! check_hostname "$host" && ! check_ipv6 "$host"; then
     echo "Invalid host: $host"
     return
   fi
 
   if [ ! -z "$port" ]; then
     if ! check_digits "$port"; then
       echo "Invalid port: $port"
       return
     fi
   fi
@@ skipping 88 matching lines @@
 }
 
 cmd_network_logging(){
   if [ -n "$1" ]; then
     case "$1" in
       "wifi")
         echo; /usr/bin/ff_debug service+wifi+inet+device+manager
         echo; /usr/bin/wpa_debug msgdump
         ;;
       "cellular")
-        echo; /usr/bin/ff_debug service+modem+device+manager  
-        echo; /usr/bin/wpa_debug info 
+        echo; /usr/bin/ff_debug service+modem+device+manager
+        echo; /usr/bin/wpa_debug info
         ;;
       "ethernet")
-        echo; /usr/bin/ff_debug service+ethernet+device+manager  
+        echo; /usr/bin/ff_debug service+ethernet+device+manager
         echo; /usr/bin/wpa_debug info
         ;;
       "--help")
         echo "Usage: network_logging <wifi | cellular | ethernet>"
         ;;
       *)
         echo "Invalid parameter $1"
         ;;
     esac
   else
@@ skipping 141 matching lines @@
   fi
 
   if ! type "cmd_$command" 2>/dev/null | head -1 | grep -q "function"; then
     echo "Unknown command: '$command'"
   else
     command="cmd_$command"
     $command $params
   fi
 }
 
-# Checks that a given string starts with an alphanumeric, and contains only
-# alphanumeric, '.' or '-' characters
+# Checks that a given string looks like a hostname or IPv4 address (starts
+# with an alphanumeric and contains only alphanumeric, '.', or '-'
+# characters).
 check_hostname() {
-  expr "$1" : '^[[:alnum:]][[:alnum:].\-]*$' > /dev/null
+  expr "$1" : '^[[:alnum:]][-[:alnum:].]*$' > /dev/null
+}
+
+# Checks that a given string could plausibly be an IPv6 address
+# (hexadecimal, ':', and '.' characters only, followed by an optional zone
+# index consisting of a '%' and a device name).
+check_ipv6() {
+  echo "$1" | /bin/grep -E -q '^[0-9a-fA-F:.]+(%[a-z0-9]+)?$'

[Daniel Erat, 2011/01/28 22:36:53]

I finally gave up on expr's poorly-documented regular expression syntax and
switched to grep -E.  Let me know if you think this will cause problems -- I'm
happy to switch back to expr if you can suggest a roughly equivalent regexp, but
nothing that I tried worked:

  ^[0-9a-fA-F:.]\{1,\}\(%[[:alnum:]]\{1,\}\)\?$

 }
 
 # Checks that a given string starts with an alphanumeric, and contains only
 # alphanumeric and zero or more of ":.~%$^\-"
 check_username() {
   expr "$1" : '^[[:alnum:]][[:alnum:]:.~%$^\-]*$' > /dev/null
 }
 
 check_digits() {
   expr "$1" : '^[[:digit:]]*$' > /dev/null
@@ skipping 19 matching lines @@
   done
 }
 
 INPUTRC="$(dirname "$0")/inputrc.crosh"
 HISTFILE="$HOME/.crosh_history"
 shell_history -r $HISTFILE
 
 repl
 
 shell_history -w $HISTFILE