5 # .../dgit-repos-server SUITES KEYRING-AUTH-SPEC DGIT-REPOS-DIR --ssh
7 # .../dgit-repos-server --pre-receive-hook PACKAGE
9 # Invoked as the ssh restricted command
11 # Works like git-receive-pack
13 # SUITES is the name of a file which lists the permissible suites
14 # one per line (#-comments and blank lines ignored)
16 # KEYRING-AUTH-SPEC is a :-separated list of
17 # KEYRING.GPG,AUTH-SPEC
18 # where AUTH-SPEC is one of
25 # - extract the destination repo name
26 # - make a hardlink clone of the destination repo
27 # - provide the destination with a stunt pre-receive hook
28 # - run actual git-receive-pack with that new destination
29 # as a result of this the stunt pre-receive hook runs; it does this:
30 # + understand what refs we are allegedly updating and
31 # check some correspondences:
32 # * we are updating only refs/tags/debian/* and refs/dgit/*
33 # * and only one of each
34 # * and the tag does not already exist
36 # * recover the suite name from the destination refs/dgit/ ref
37 # + disassemble the signed tag into its various fields and signature
39 # * parsing the first line of the tag message to recover
40 # the package name, version and suite
41 # * checking that the package name corresponds to the dest repo name
42 # * checking that the suite name is as recovered above
43 # + verify the signature on the signed tag
44 # and if necessary check that the keyid and package are listed in dm.txt
45 # + check various correspondences:
46 # * the suite is one of those permitted
47 # * the signed tag must refer to a commit
48 # * the signed tag commit must be the refs/dgit value
49 # * the name in the signed tag must correspond to its ref name
50 # * the tag name must be debian/<version> (massaged as needed)
51 # * the signed tag has a suitable name
52 # * the commit is a fast forward
53 # + push the signed tag and new dgit branch to the actual repo
55 # If the destination repo does not already exist, we need to make
56 # sure that we create it reasonably atomically, and also that
57 # we don't every have a destination repo containing no refs at all
58 # (because such a thing causes git-fetch-pack to barf). So then we
59 # do as above, except:
60 # - before starting, we take out our own lock for the destination repo
61 # - we create a prospective new destination repo by making a copy
63 # - we use the prospective new destination repo instead of the
64 # actual new destination repo (since the latter doesn't exist)
65 # - we set up a post-receive hook as well, which
66 # + touches a stamp file
67 # - after git-receive-pack exits, we
68 # + check that the prospective repo contains a tag and head
69 # + rename the prospective destination repo into place
73 # - Temporary working trees and their locks are cleaned up
74 # opportunistically by a program which tries to take each lock and
75 # if successful deletes both the tree and the lockfile
76 # - Prospective working trees and their locks are cleaned up by
77 # a program which tries to take each lock and if successful
78 # deletes any prospective working tree and the lock (but not
79 # of course any actual tree)
80 # - It is forbidden to _remove_ the lockfile without removing
81 # the corresponding temporary tree, as the lockfile is also
82 # a stampfile whose presence indicates that there may be
87 use File::Path qw(rmtree);
89 open DEBUG, ">/dev/null" or die $!;
91 our $package_re = '[0-9a-z][-+.0-9a-z]+';
104 #----- utilities -----
107 print DEBUG "$debug @_\n";
110 sub acquirelock ($$) {
111 my ($lock, $must) = @_;
113 printf DEBUG "$debug locking %s %d\n", $lock, $must;
116 $fh = new IO::File $lock, ">" or die "open $lock: $!";
117 my $ok = flock $fh, $must ? LOCK_EX : (LOCK_EX|LOCK_NB);
119 die "flock $lock: $!" if $must;
120 debug " locking $lock failed";
124 next if $! == ENOENT;
125 die "stat $lock: $!";
127 my $want = (stat _)[1];
129 my $got = (stat _)[1];
130 last if $got == $want;
135 sub acquiretree ($$) {
136 my ($tree, $must) = @_;
137 my $fh = acquirelock("$tree.lock", $must);
146 my $tmpdir = "$dgitrepos/_tmp";
147 return if mkdir $tmpdir;
148 return if $! == EEXIST;
154 my $w = $ENV{'DGIT_DRS_WORK'}; # we are in stunthook
156 open REJ, ">", "$w/drs-reject" or die $!;
157 print REJ $why, "\n" or die $!;
160 die "dgit-repos-server: reject: $why\n";
166 local $Data::Dumper::Indent = 0;
167 local $Data::Dumper::Terse = 1;
168 debug "|".Dumper(\@_);
176 die "@_ $? $!" if $r;
179 #----- git-receive-pack -----
181 sub fixmissing__git_receive_pack () {
183 $destrepo = "$dgitrepos/_tmp/${package}_prospective";
184 acquiretree($destrepo, 1);
185 my $template = "$dgitrepos/_template";
186 debug "fixmissing copy tempalate $template -> $destrepo";
187 my $r = system qw(cp -a --), $template, $destrepo;
188 !$r or die "create new repo failed failed: $r $!";
191 sub makeworkingclone () {
193 $workrepo = "$dgitrepos/_tmp/${package}_incoming$$";
194 acquiretree($workrepo, 1);
195 runcmd qw(git clone -l -q --mirror), $destrepo, $workrepo;
198 sub setupstunthook () {
199 my $prerecv = "$workrepo/hooks/pre-receive";
200 my $fh = new IO::File $prerecv, O_WRONLY|O_CREAT|O_TRUNC, 0777
201 or die "$prerecv: $!";
202 print $fh <<END or die "$prerecv: $!";
205 exec $0 --pre-receive-hook $package
207 close $fh or die "$prerecv: $!";
208 $ENV{'DGIT_DRS_WORK'}= $workrepo;
209 $ENV{'DGIT_DRS_DEST'}= $destrepo;
210 debug " stunt hook set up $prerecv";
213 sub maybeinstallprospective () {
214 return if $destrepo eq $realdestrepo;
216 if (open REJ, "<", "$workrepo/drs-reject") {
217 $!=0; my $why = <REJ>;
218 chomp $why or die $!;
221 $!==&ENOENT or die $!;
224 debug " show-ref ($destrepo) ...";
226 my $child = open SR, "-|";
227 defined $child or die $!;
229 chdir $destrepo or die $!;
230 exec qw(git show-ref);
233 my %got = qw(tag 0 head 0);
236 debug " show-refs| $_";
237 s/^\S*[1-9a-f]\S* (\S+)$/$1/ or die;
239 m{^refs/tags/} ? 'tag' :
240 m{^refs/dgit/} ? 'head' :
244 $!=0; $?=0; close SR or $?==256 or die "$? $!";
246 debug "installprospective ?";
247 die Dumper(\%got)." -- missing refs in new repo"
248 if grep { !$_ } values %got;
250 debug "install $destrepo => $realdestrepo";
251 rename $destrepo, $realdestrepo or die $!;
252 remove "$destrepo.lock" or die $!;
255 sub main__git_receive_pack () {
258 runcmd qw(git receive-pack), $workrepo;
259 maybeinstallprospective();
262 #----- stunt post-receive hook -----
264 our ($tagname, $tagval, $suite, $oldcommit, $commit);
265 our ($version, %tagh);
268 debug " updates ...";
272 m/^(\S+) (\S+) (\S+)$/ or die "$_ ?";
273 my ($old, $sha1, $refname) = ($1, $2, $3);
274 if ($refname =~ m{^refs/tags/(?=debian/)}) {
275 die if defined $tagname;
278 reject "tag $tagname already exists -".
279 " not replacing previously-pushed version"
281 } elsif ($refname =~ m{^refs/dgit/}) {
282 die if defined $suite;
290 STDIN->error and die $!;
292 die unless defined $tagname;
293 die unless defined $suite;
294 debug " updates ok.";
298 debug " parsetag...";
299 open PT, ">dgit-tmp/plaintext" or die $!;
300 open DS, ">dgit-tmp/plaintext.asc" or die $!;
301 open T, "-|", qw(git cat-file tag), $tagval or die $!;
303 $!=0; $_=<T>; defined or die $!;
305 if (m/^(\S+) (.*)/) {
306 push @{ $tagh{$1} }, $2;
313 $!=0; $_=<T>; defined or die $!;
314 m/^($package_re) release (\S+) for \S+ \((\S+)\) \[dgit\]$/ or
315 reject "tag message not in expected format";
317 die unless $1 eq $package;
319 die "$3 != $suite " unless $3 eq $suite;
323 $!=0; $_=<T>; defined or die $!;
324 last if m/^-----BEGIN PGP/;
334 debug " parsetag ok.";
337 sub checksig_keyring ($) {
338 my ($keyringfile) = @_;
339 # returns primary-keyid if signed by a key in this keyring
341 # or dies on other errors
345 debug " checksig keyring $keyringfile...";
347 open P, "-|", (qw(gpgv --status-fd=1 --keyring),
349 qw(dgit-tmp/plaintext.asc dgit-tmp/plaintext))
353 next unless s/^\[GNUPG:\]: //;
355 debug " checksig| $_";
356 my @l = split / /, $_;
357 if ($l[0] eq 'NO_PUBKEY') {
359 } elsif ($l[0] eq 'VALIDSIG') {
361 $sigtype eq '00' or reject "signature is not of type 00!";
363 die unless defined $ok;
369 debug sprintf " checksig ok=%d", !!$ok;
374 sub dm_txt_check ($$) {
375 my ($keyid, $dmtxtfn) = @_;
376 debug " dm_txt_check $keyid $dmtxtfn";
377 open DT, '<', $dmtxtfn or die "$dmtxtfn $!";
379 m/^fingerprint:\s+$keyid$/oi
382 or reject "key $keyid missing Allow section in permissions!";
387 or reject "package $package not allowed for key $keyid";
392 debug " dm_txt_check allow| $_";
393 foreach my $p (split /\s+/) {
394 if ($p eq $package) {
396 debug " dm_txt_check ok";
401 DT->error and die $!;
403 reject "key $keyid not in permissions list although in keyring!";
407 foreach my $kas (split /:/, $keyrings) {
408 debug "verifytag $kas...";
409 $kas =~ s/^([^,]+),// or die;
410 my $keyid = checksig_keyring $1;
411 if (defined $keyid) {
412 if ($kas =~ m/^a$/) {
413 debug "verifytag a ok";
415 } elsif ($kas =~ m/^m([^,]+)$/) {
416 dm_txt_check($keyid, $1);
417 debug "verifytag m ok";
424 reject "key not found in keyrings";
429 open SUITES, "<", $suitesfile or die $!;
435 return if $_ eq $suite;
437 die $! if SUITES->error;
438 reject "unknown suite";
444 tagh1('type') eq 'commit' or die;
445 tagh1('object') eq $commit or die;
446 tagh1('tag') eq $tagname or die;
451 debug "translated version $v";
452 $tagname eq "debian/$v" or die;
454 # check that our ref is being fast-forwarded
455 debug "oldcommit $oldcommit";
456 if ($oldcommit =~ m/[^0]/) {
457 $?=0; $!=0; my $mb = `git merge-base $commit $oldcommit`;
459 $mb eq $oldcommit or reject "not fast forward on dgit branch";
464 my @cmd = (qw(git send-pack), $destrepo,
465 "$commit:refs/dgit/$suite",
466 "$tagval:refs/tags/$tagname");
470 !$r or die "onward push failed: $r $!";
475 print Dumper(\$ENV{GIT_DIR});
476 chdir $workrepo or die "chdir $workrepo: $!";
477 mkdir "dgit-tmp" or $!==EEXIST or die $!;
483 debug "stunthook done.";
486 #----- git-upload-pack -----
488 sub fixmissing__git_upload_pack () {
489 $destrepo = "$dgitrepos/_empty";
490 my $lfh = acquiretree($destrepo,1);
491 return if stat $destrepo;
492 die $! unless $!==ENOENT;
493 rmtree "$destrepo.new";
495 runcmd qw(git init --bare --quiet), "$destrepo.new";
496 rename "$destrepo.new", $destrepo or die $!;
497 unlink "$destrepo.lock" or die $!;
501 sub main__git_upload_pack () {
502 runcmd qw(git upload-pack), $destrepo;
505 #----- arg parsing and main program -----
514 sub parseargsdispatch () {
517 delete $ENV{'GIT_DIR'}; # if not run via ssh, our parent git process
518 delete $ENV{'GIT_PREFIX'}; # sets these and they mess things up
520 if ($ENV{'DGIT_DRS_DEBUG'}) {
522 open DEBUG, ">&STDERR" or die $!;
525 if ($ARGV[0] eq '--pre-receive-hook') {
526 if ($debug) { $debug.="="; }
529 $package = shift @ARGV;
530 defined($suitesfile = $ENV{'DGIT_DRS_SUITES'}) or die;
531 defined($workrepo = $ENV{'DGIT_DRS_WORK'}) or die;
532 defined($destrepo = $ENV{'DGIT_DRS_DEST'}) or die;
533 defined($keyrings = $ENV{'DGIT_DRS_KEYRINGS'}) or die $!;
534 open STDOUT, ">&STDERR" or die $!;
539 $ENV{'DGIT_DRS_SUITES'} = argval();
540 $ENV{'DGIT_DRS_KEYRINGS'} = argval();
541 $dgitrepos = argval();
543 die unless @ARGV==1 && $ARGV[0] eq '--ssh';
545 my $cmd = $ENV{'SSH_ORIGINAL_COMMAND'};
555 or reject "command string not understood";
558 $realdestrepo = "$dgitrepos/$package.git";
562 my $mainfunc = $main::{"main__$funcn"};
564 reject "unknown method" unless $mainfunc;
566 if (stat $realdestrepo) {
567 $destrepo = $realdestrepo;
569 $! == ENOENT or die "stat dest repo $destrepo: $!";
570 debug " fixmissing $funcn";
571 my $fixfunc = $main::{"fixmissing__$funcn"};
575 debug " running main $funcn";
580 while (my $fh = pop @lockfhs) { close $fh; }
585 if (!chdir "$dgitrepos/_tmp") {
586 $!==ENOENT or die $!;
589 foreach my $lf (<*.lock>) {
591 $tree =~ s/\.lock$//;
592 next unless acquiretree($tree, 0);
593 remove $lf or warn $!;