source: trunk/server/common/oursrc/execsys/svnproxy.pl @ 1337

Last change on this file since 1337 was 903, checked in by andersk, 14 years ago
Replace {svnproxy,gitproxy} select() loop with a poll() loop, to catch closed output handles. This should prevent the gitproxy deadlock on errors.
  • Property svn:executable set to *
File size: 4.5 KB
Line 
1#!/usr/bin/perl
2#
3# svnproxy: Wrapper around svnserve for Subversion virtual hosting.
4# version 1.1, released 2008-12-28
5# Copyright © 2008 Anders Kaseorg <andersk@mit.edu>
6#
7# This program is free software; you can redistribute it and/or
8# modify it under the terms of the GNU General Public License
9# as published by the Free Software Foundation; either version 2
10# of the License, or (at your option) any later version.
11#
12# This program is distributed in the hope that it will be useful,
13# but WITHOUT ANY WARRANTY; without even the implied warranty of
14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15# GNU General Public License for more details.
16#
17# You should have received a copy of the GNU General Public License
18# along with this program; if not, write to the Free Software
19# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
20
21use strict;
22use warnings;
23use IPC::Open2;
24use Errno qw(EINTR);
25use IO::Poll qw(POLLIN POLLOUT POLLHUP);
26
27# Read the initial greeting from a dummy svnserve process.
28my $pid = open(IN, '-|');
29defined $pid or die "$0: open: $!";
30if ($pid == 0) {
31    close(STDIN) or die "$0: close: $!";
32    exec('svnserve', '-i') or die "$0: exec svnproxy: $!";
33}
34my $greeting = '';
35for (;;) {
36    my $n = sysread(IN, my $buf, 4096);
37    next if $n < 0 and $! == EINTR;
38    $n >= 0 or die "$0: read: $!";
39    last if $n == 0;
40    $greeting .= $buf;
41}
42
43# Send the greeting to the client.
44my $buf = $greeting;
45while ($buf ne '') {
46    my $n = syswrite(STDOUT, $buf);
47    next if $n < 0 and $! == EINTR;
48    $n >= 0 or die "$0: write: $!";
49    $buf = substr($buf, $n);
50}
51close(IN) or die "$0: close: $!";
52waitpid(-1, 0) or die "$0: waitpid: $!";
53
54# Receive the response from the client, and parse out the URL.
55my $url;
56my $response = '';
57for (;;) {
58    my $n = sysread(STDIN, my $buf, 4096);
59    next if $n < 0 and $! == EINTR;
60    $n >= 0 or die "$0: read: $!";
61    $n > 0 or die "$0: unexpected response from client";
62    $response .= $buf;
63    my $url_len;
64    if (($url_len) = $response =~ m/^\(\s\S+\s\(\s[^)]*\)\s(\d+):/ and
65        length($') >= $url_len) {
66        $url = substr($', 0, $url_len);
67        last;
68    } elsif ($response !~ m/^(?:\((?:\s(?:\S+(?:\s(?:\((?:\s(?:[^)]*(?:\)(?:\s(?:\d+:?)?)?)?)?)?)?)?)?)?)?$/) {
69        die "$0: unexpected response from client";
70    }
71}
72
73# Now start the real svnserve based on the URL.
74$pid = open2(\*IN, \*OUT, '/usr/local/sbin/ldapize.pl', $url) or die "$0: open: $!";
75
76# Read the greeting, expecting it to be identical to the dummy greeting.
77while ($greeting ne '') {
78    my $n = sysread(IN, my $buf, length($greeting));
79    next if $n < 0 and $! == EINTR;
80    $n >= 0 or die "$0: read: $!";
81    $n > 0 or die "$0: svnserve unexpectedly closed connection";
82    $greeting =~ s/^\Q$buf\E// or die "$0: unexpected greeting from svnserve";
83}
84
85# Finally, go into a select loop to transfer the remaining data
86# (STDIN -> OUT, IN -> STDOUT), including the client's response to svnserve.
87my ($cbuf, $sbuf) = ($response, '');
88my $poll = new IO::Poll;
89$poll->mask(\*STDOUT => POLLHUP);
90$poll->mask(\*OUT => POLLOUT);
91$poll->remove(\*STDIN);
92$poll->mask(\*IN => POLLIN);
93while ($poll->handles()) {
94    my $n = $poll->poll();
95    next if $n < 0 and $! == EINTR;
96    $n >= 0 or die "select: $!";
97    if ($poll->events(\*STDIN)) {
98        my $n = sysread(STDIN, $cbuf, 4096);
99        next if $n < 0 and $! == EINTR;
100        $n >= 0 or die "read: $!";
101        $poll->remove(\*STDIN);
102        $poll->mask(\*OUT => POLLOUT);
103    } elsif ($poll->events(\*IN)) {
104        my $n = sysread(IN, $sbuf, 4096);
105        next if $n < 0 and $! == EINTR;
106        $n >= 0 or die "read: $!";
107        $poll->remove(\*IN);
108        $poll->mask(\*STDOUT => POLLOUT);
109    } elsif ($poll->events(\*STDOUT) & POLLOUT && $sbuf ne '') {
110        my $n = syswrite(STDOUT, $sbuf);
111        next if $n < 0 and $! == EINTR;
112        $n >= 0 or die "write: $!";
113        $sbuf = substr($sbuf, $n);
114        if ($sbuf eq '') {
115            $poll->mask(\*STDOUT => POLLHUP);
116            $poll->mask(\*IN => POLLIN);
117        }
118    } elsif ($poll->events(\*STDOUT)) {
119        $poll->remove(\*STDOUT);
120        $poll->remove(\*IN);
121        close(STDOUT) or die "close: $!";
122        close(IN) or die "close: $!";
123    } elsif ($poll->events(\*OUT) & POLLOUT && $cbuf ne '') {
124        my $n = syswrite(OUT, $cbuf);
125        next if $n < 0 and $! == EINTR;
126        $n >= 0 or die "write: $!";
127        $cbuf = substr($cbuf, $n);
128        if ($cbuf eq '') {
129            $poll->mask(\*OUT => POLLHUP);
130            $poll->mask(\*STDIN => POLLIN);
131        }
132    } elsif ($poll->events(\*OUT)) {
133        $poll->remove(\*OUT);
134        $poll->remove(\*STDIN);
135        close(OUT) or die "close: $!";
136        close(STDIN) or die "close: $!";
137    }
138}
139
140while (waitpid($pid, 0) == -1 && $! == EINTR) { }
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