X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/5e7f63f0bf98f9d7baab80430535d02915ade88c..c8fa85b23bfebc68f0ab2e0464937f5ee4a8bf69:/support/deny-rsync

diff --git a/support/deny-rsync b/support/deny-rsync
index c563186c..1993e3aa 100755
--- a/support/deny-rsync
+++ b/support/deny-rsync
@@ -1,31 +1,36 @@
 #!/bin/bash
-# deny-rsync [message]: send an rsync-protocol error message
+# Send an error message via the rsync-protocol to a non-daemon client rsync.
+#
+# Usage:  deny-rsync "message"
 
 protocol_version=29
 exit_code=4 # same as a daemon that refuses an option
 
-# byte_escape 29 ==> \035
+# e.g. byte_escape 29 => \035
 function byte_escape {
-    octbyte="000$(bc <<<"obase=8; $1")"
-    echo -n "\\${octbyte: -3}"
+    echo -ne "\\0$(printf "%o" $1)"
 }
 
 msg="$1"
-if [ "${#msg}" -gt 255 ]; then
-    # message is too long for this naive script to handle
-    msg="${msg:0:252}..."
+if [ "${#msg}" -gt 254 ]; then
+    # truncate a message that is too long for this naive script to handle
+    msg="${msg:0:251}..."
 fi
+msglen=$(( ${#msg} + 1 )) # add 1 for the newline we append below
 
-# send protocol version
+# Send protocol version.  All numbers are LSB-first 4-byte ints.
 echo -ne "$(byte_escape $protocol_version)\\000\\000\\000"
 
-# send checksum seed
+# Send a zero checksum seed.
 echo -ne "\\000\\000\\000\\000"
 
-# the following is equivalent to rwrite(FERROR, $msg)
-# message header: length 17; MPLEX_BASE + code FERROR
-echo -ne "$(byte_escape ${#msg})\\000\\000\\010"
-# data
-echo -n "$msg"
+# The following is equivalent to rprintf(FERROR_XFER, "%s\n", $msg).
+# 1. Message header: ((MPLEX_BASE + FERROR_XFER) << 24) + $msglen.
+echo -ne "$(byte_escape $msglen)\\000\\000\\010"
+# 2. The actual data.
+echo -E "$msg"
+
+# Make sure the client gets our message, not a write failure.
+sleep 1
 
 exit $exit_code