t/lib-git-daemon: add network-protocol helpers

All of our git-protocol tests rely on invoking the client
and having it make a request of a server. That gives a nice
real-world test of how the two behave together, but it
doesn't leave any room for testing how a server might react
to _other_ clients.

Let's add a few test helper functions which can be used to
manually conduct a git-protocol conversation with a remote
git-daemon:

  1. To connect to a remote git-daemon, we need something
     like "netcat". But not everybody will have netcat. And
     even if they do, the behavior with respect to
     half-duplex shutdowns is not portable (openbsd netcat
     has "-N", with others you must rely on "-q 1", which is
     racy).

     Here we provide a "fake_nc" that is capable of doing
     a client-side netcat, with sane half-duplex semantics.
     It relies on perl's IO::Socket::INET. That's been in
     the base distribution since 5.6.0, so it's probably
     available everywhere. But just to be on the safe side,
     we'll add a prereq.

  2. To help tests speak and read pktline, this patch adds
     packetize() and depacketize() functions.

I've put fake_nc() into lib-git-daemon.sh, since that's
really the only server where we'd need to use a network
socket.  Whereas the pktline helpers may be of more general
use, so I've added them to test-lib-functions.sh. Programs
like upload-pack speak pktline, but can talk directly over
stdio without a network socket.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King 2018-01-24 19:58:19 -05:00 коммит произвёл Junio C Hamano
Родитель 550fbcad1c
Коммит 4414a15002
2 изменённых файлов: 58 добавлений и 1 удалений

Просмотреть файл

@ -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"
'

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@ -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;
}
}
}
'
}