diff --git a/t/lib-git-daemon.sh b/t/lib-git-daemon.sh
index 9612cccefb..edbea2d986 100644
--- a/t/lib-git-daemon.sh
+++ b/t/lib-git-daemon.sh
@@ -32,7 +32,8 @@ LIB_GIT_DAEMON_PORT=${LIB_GIT_DAEMON_PORT-${this_test#t}}
 
 GIT_DAEMON_PID=
 GIT_DAEMON_DOCUMENT_ROOT_PATH="$PWD"/repo
-GIT_DAEMON_URL=git://127.0.0.1:$LIB_GIT_DAEMON_PORT
+GIT_DAEMON_HOST_PORT=127.0.0.1:$LIB_GIT_DAEMON_PORT
+GIT_DAEMON_URL=git://$GIT_DAEMON_HOST_PORT
 
 start_git_daemon() {
 	if test -n "$GIT_DAEMON_PID"
@@ -98,3 +99,25 @@ stop_git_daemon() {
 	GIT_DAEMON_PID=
 	rm -f git_daemon_output
 }
+
+# A stripped-down version of a netcat client, that connects to a "host:port"
+# given in $1, sends its stdin followed by EOF, then dumps the response (until
+# EOF) to stdout.
+fake_nc() {
+	if ! test_declared_prereq FAKENC
+	then
+		echo >&4 "fake_nc: need to declare FAKENC prerequisite"
+		return 127
+	fi
+	perl -Mstrict -MIO::Socket::INET -e '
+		my $s = IO::Socket::INET->new(shift)
+			or die "unable to open socket: $!";
+		print $s <STDIN>;
+		$s->shutdown(1);
+		print <$s>;
+	' "$@"
+}
+
+test_lazy_prereq FAKENC '
+	perl -MIO::Socket::INET -e "exit 0"
+'
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 1701fe2a06..a679b02a1c 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -1020,3 +1020,37 @@ nongit () {
 		"$@"
 	)
 }
+
+# convert stdin to pktline representation; note that empty input becomes an
+# empty packet, not a flush packet (for that you can just print 0000 yourself).
+packetize() {
+	cat >packetize.tmp &&
+	len=$(wc -c <packetize.tmp) &&
+	printf '%04x%s' "$(($len + 4))" &&
+	cat packetize.tmp &&
+	rm -f packetize.tmp
+}
+
+# Parse the input as a series of pktlines, writing the result to stdout.
+# Sideband markers are removed automatically, and the output is routed to
+# stderr if appropriate.
+#
+# NUL bytes are converted to "\\0" for ease of parsing with text tools.
+depacketize () {
+	perl -e '
+		while (read(STDIN, $len, 4) == 4) {
+			if ($len eq "0000") {
+				print "FLUSH\n";
+			} else {
+				read(STDIN, $buf, hex($len) - 4);
+				$buf =~ s/\0/\\0/g;
+				if ($buf =~ s/^[\x2\x3]//) {
+					print STDERR $buf;
+				} else {
+					$buf =~ s/^\x1//;
+					print $buf;
+				}
+			}
+		}
+	'
+}