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| -rw-r--r-- | contrib/hooks/update-paranoid | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/contrib/hooks/update-paranoid b/contrib/hooks/update-paranoid new file mode 100644 index 0000000000..5ee1835c80 --- /dev/null +++ b/contrib/hooks/update-paranoid @@ -0,0 +1,284 @@ +#!/usr/bin/perl + +use strict; +use File::Spec; + +$ENV{PATH} = '/opt/git/bin'; +my $acl_git = '/vcs/acls.git'; +my $acl_branch = 'refs/heads/master'; +my $debug = 0; + +=doc +Invoked as: update refname old-sha1 new-sha1 + +This script is run by git-receive-pack once for each ref that the +client is trying to modify. If we exit with a non-zero exit value +then the update for that particular ref is denied, but updates for +other refs in the same run of receive-pack may still be allowed. + +We are run after the objects have been uploaded, but before the +ref is actually modified. We take advantage of that fact when we +look for "new" commits and tags (the new objects won't show up in +`rev-list --all`). + +This script loads and parses the content of the config file +"users/$this_user.acl" from the $acl_branch commit of $acl_git ODB. +The acl file is a git-config style file, but uses a slightly more +restricted syntax as the Perl parser contained within this script +is not nearly as permissive as git-config. + +Example: + + [user] + committer = John Doe <john.doe@example.com> + committer = John R. Doe <john.doe@example.com> + + [repository "acls"] + allow = heads/master + allow = CDUR for heads/jd/ + allow = C for ^tags/v\\d+$ + +For all new commit or tag objects the committer (or tagger) line +within the object must exactly match one of the user.committer +values listed in the acl file ("HEAD:users/$this_user.acl"). + +For a branch to be modified an allow line within the matching +repository section must be matched for both the refname and the +opcode. + +Repository sections are matched on the basename of the repository +(after removing the .git suffix). + +The opcode abbrevations are: + + C: create new ref + D: delete existing ref + U: fast-forward existing ref (no commit loss) + R: rewind/rebase existing ref (commit loss) + +if no opcodes are listed before the "for" keyword then "U" (for +fast-forward update only) is assumed as this is the most common +usage. + +Refnames are matched by always assuming a prefix of "refs/". +This hook forbids pushing or deleting anything not under "refs/". + +Refnames that start with ^ are Perl regular expressions, and the ^ +is kept as part of the regexp. \\ is needed to get just one \, so +\\d expands to \d in Perl. The 3rd allow line above is an example. + +Refnames that don't start with ^ but that end with / are prefix +matches (2nd allow line above); all other refnames are strict +equality matches (1st allow line). + +Anything pushed to "heads/" (ok, really "refs/heads/") must be +a commit. Tags are not permitted here. + +Anything pushed to "tags/" (err, really "refs/tags/") must be an +annotated tag. Commits, blobs, trees, etc. are not permitted here. +Annotated tag signatures aren't checked, nor are they required. + +The special subrepository of 'info/new-commit-check' can +be created and used to allow users to push new commits and +tags from another local repository to this one, even if they +aren't the committer/tagger of those objects. In a nut shell +the info/new-commit-check directory is a Git repository whose +objects/info/alternates file lists this repository and all other +possible sources, and whose refs subdirectory contains symlinks +to this repository's refs subdirectory, and to all other possible +sources refs subdirectories. Yes, this means that you cannot +use packed-refs in those repositories as they won't be resolved +correctly. + +=cut + +my $git_dir = $ENV{GIT_DIR}; +my $new_commit_check = "$git_dir/info/new-commit-check"; +my $ref = $ARGV[0]; +my $old = $ARGV[1]; +my $new = $ARGV[2]; +my $new_type; +my ($this_user) = getpwuid $<; # REAL_USER_ID +my $repository_name; +my %user_committer; +my @allow_rules; + +sub deny ($) { + print STDERR "-Deny- $_[0]\n" if $debug; + print STDERR "\ndenied: $_[0]\n\n"; + exit 1; +} + +sub grant ($) { + print STDERR "-Grant- $_[0]\n" if $debug; + exit 0; +} + +sub info ($) { + print STDERR "-Info- $_[0]\n" if $debug; +} + +sub parse_config ($$) { + my ($data, $fn) = @_; + info "Loading $fn"; + open(I,'-|','git',"--git-dir=$acl_git",'cat-file','blob',$fn); + my $section = ''; + while (<I>) { + chomp; + if (/^\s*$/ || /^\s*#/) { + } elsif (/^\[([a-z]+)\]$/i) { + $section = $1; + } elsif (/^\[([a-z]+)\s+"(.*)"\]$/i) { + $section = "$1.$2"; + } elsif (/^\s*([a-z][a-z0-9]+)\s*=\s*(.*?)\s*$/i) { + push @{$data->{"$section.$1"}}, $2; + } else { + deny "bad config file line $. in $fn"; + } + } + close I; +} + +sub all_new_committers () { + local $ENV{GIT_DIR} = $git_dir; + $ENV{GIT_DIR} = $new_commit_check if -d $new_commit_check; + + info "Getting committers of new commits."; + my %used; + open(T,'-|','git','rev-list','--pretty=raw',$new,'--not','--all'); + while (<T>) { + next unless s/^committer //; + chop; + s/>.*$/>/; + info "Found $_." unless $used{$_}++; + } + close T; + info "No new commits." unless %used; + keys %used; +} + +sub all_new_taggers () { + my %exists; + open(T,'-|','git','for-each-ref','--format=%(objectname)','refs/tags'); + while (<T>) { + chop; + $exists{$_} = 1; + } + close T; + + info "Getting taggers of new tags."; + my %used; + my $obj = $new; + my $obj_type = $new_type; + while ($obj_type eq 'tag') { + last if $exists{$obj}; + $obj_type = ''; + open(T,'-|','git','cat-file','tag',$obj); + while (<T>) { + chop; + if (/^object ([a-z0-9]{40})$/) { + $obj = $1; + } elsif (/^type (.+)$/) { + $obj_type = $1; + } elsif (s/^tagger //) { + s/>.*$/>/; + info "Found $_." unless $used{$_}++; + last; + } + } + close T; + } + info "No new tags." unless %used; + keys %used; +} + +sub check_committers (@) { + my @bad; + foreach (@_) { push @bad, $_ unless $user_committer{$_}; } + if (@bad) { + print STDERR "\n"; + print STDERR "You are not $_.\n" foreach (sort @bad); + deny "You cannot push changes not committed by you."; + } +} + +sub git_value (@) { + open(T,'-|','git',@_); local $_ = <T>; chop; close T; + $_; +} + +deny "No GIT_DIR inherited from caller" unless $git_dir; +deny "Need a ref name" unless $ref; +deny "Refusing funny ref $ref" unless $ref =~ s,^refs/,,; +deny "Bad old value $old" unless $old =~ /^[a-z0-9]{40}$/; +deny "Bad new value $new" unless $new =~ /^[a-z0-9]{40}$/; +deny "Cannot determine who you are." unless $this_user; + +$repository_name = File::Spec->rel2abs($git_dir); +$repository_name =~ m,/([^/]+)(?:\.git|/\.git)$,; +$repository_name = $1; +info "Updating in '$repository_name'."; + +my $op; +if ($old =~ /^0{40}$/) { $op = 'C'; } +elsif ($new =~ /^0{40}$/) { $op = 'D'; } +else { $op = 'R'; } + +# This is really an update (fast-forward) if the +# merge base of $old and $new is $old. +# +$op = 'U' if ($op eq 'R' + && $ref =~ m,^heads/, + && $old eq git_value('merge-base',$old,$new)); + +# Load the user's ACL file. +{ + my %data = ('user.committer' => []); + parse_config(\%data, "$acl_branch:users/$this_user.acl"); + %user_committer = map {$_ => $_} @{$data{'user.committer'}}; + my $rules = $data{"repository.$repository_name.allow"} || []; + foreach (@$rules) { + if (/^([CDRU ]+)\s+for\s+([^\s]+)$/) { + my $ops = $1; + my $ref = $2; + $ops =~ s/ //g; + $ref =~ s/\\\\/\\/g; + push @allow_rules, [$ops, $ref]; + } elsif (/^for\s+([^\s]+)$/) { + # Mentioned, but nothing granted? + } elsif (/^[^\s]+$/) { + s/\\\\/\\/g; + push @allow_rules, ['U', $_]; + } + } +} + +if ($op ne 'D') { + $new_type = git_value('cat-file','-t',$new); + + if ($ref =~ m,^heads/,) { + deny "$ref must be a commit." unless $new_type eq 'commit'; + } elsif ($ref =~ m,^tags/,) { + deny "$ref must be an annotated tag." unless $new_type eq 'tag'; + } + + check_committers (all_new_committers); + check_committers (all_new_taggers) if $new_type eq 'tag'; +} + +info "$this_user wants $op for $ref"; +foreach my $acl_entry (@allow_rules) { + my ($acl_ops, $acl_n) = @$acl_entry; + next unless $acl_ops =~ /^[CDRU]+$/; # Uhh.... shouldn't happen. + next unless $acl_n; + next unless $op =~ /^[$acl_ops]$/; + + grant "Allowed by: $acl_ops for $acl_n" + if ( + ($acl_n eq $ref) + || ($acl_n =~ m,/$, && substr($ref,0,length $acl_n) eq $acl_n) + || ($acl_n =~ m,^\^, && $ref =~ m:$acl_n:) + ); +} +close A; +deny "You are not permitted to $op $ref"; |