www: workaround for malformed NNTP links

Some linkifiers to create invalid HTTP links when it sees a
link intended for NNTP services.  This means we may see links
to news.public-inbox.org/inbox.comp.mail.public-inbox.meta
point to "http://" on port 80 instead of 119.  Try to
redirect users to http://public-inbox.org/meta/ in this case.

1 files changed, 41 insertions, 26 deletions

diff --git a/lib/PublicInbox/WWW.pm b/lib/PublicInbox/WWW.pm
index 83729273..fd092803 100644
--- a/lib/PublicInbox/WWW.pm
+++ b/lib/PublicInbox/WWW.pm
@@ -45,7 +45,7 @@ sub call {
         if ($method eq 'POST' &&
                  $path_info =~ m!$LISTNAME_RE/(git-upload-pack)\z!) {
                 my $path = $2;
-                return (invalid_list($ctx, $1) ||
+                return (invalid_list($self, $ctx, $1) ||
                         serve_git($cgi, $ctx->{git}, $path));
         }
         elsif ($method !~ /\AGET|HEAD\z/) {
@@ -56,18 +56,19 @@ sub call {
         if ($path_info eq '/') {
                 r404();
         } elsif ($path_info =~ m!$LISTNAME_RE\z!o) {
-                invalid_list($ctx, $1) || r301($ctx, $1);
+                invalid_list($self, $ctx, $1) || r301($ctx, $1);
         } elsif ($path_info =~ m!$LISTNAME_RE(?:/|/index\.html)?\z!o) {
-                invalid_list($ctx, $1) || get_index($ctx);
+                invalid_list($self, $ctx, $1) || get_index($ctx);
         } elsif ($path_info =~ m!$LISTNAME_RE/(?:atom\.xml|new\.atom)\z!o) {
-                invalid_list($ctx, $1) || get_atom($ctx);
+                invalid_list($self, $ctx, $1) || get_atom($ctx);
 
         } elsif ($path_info =~ m!$LISTNAME_RE/
                                 ($PublicInbox::GitHTTPBackend::ANY)\z!ox) {
                 my $path = $2;
-                invalid_list($ctx, $1) || serve_git($cgi, $ctx->{git}, $path);
+                invalid_list($self, $ctx, $1) ||
+                        serve_git($cgi, $ctx->{git}, $path);
         } elsif ($path_info =~ m!$LISTNAME_RE/$MID_RE/$END_RE\z!o) {
-                msg_page($ctx, $1, $2, $3);
+                msg_page($self, $ctx, $1, $2, $3);
 
         # in case people leave off the trailing slash:
         } elsif ($path_info =~ m!$LISTNAME_RE/$MID_RE/(f|T|t|R)\z!o) {
@@ -80,7 +81,7 @@ sub call {
                 r301($ctx, $1, $2);
 
         } else {
-                legacy_redirects($ctx, $path_info);
+                legacy_redirects($self, $ctx, $path_info);
         }
 }
 
@@ -118,7 +119,7 @@ sub r { [ $_[0], ['Content-Type' => 'text/plain'], [ join(' ', @_, "\n") ] ] }
 
 # returns undef if valid, array ref response if invalid
 sub invalid_list {
-        my ($ctx, $listname) = @_;
+        my ($self, $ctx, $listname, $mid) = @_;
         my $git_dir = $ctx->{pi_config}->get($listname, "mainrepo");
         if (defined $git_dir) {
                 $ctx->{git_dir} = $git_dir;
@@ -126,17 +127,23 @@ sub invalid_list {
                 $ctx->{listname} = $listname;
                 return;
         }
-        r404();
+
+        # sometimes linkifiers (not ours!) screw up automatic link
+        # generation and link things intended for nntp:// to https?://,
+        # so try to infer links and redirect them to the appropriate
+        # list URL.
+        $self->news_www->call($ctx->{cgi}->{env});
 }
 
 # returns undef if valid, array ref response if invalid
 sub invalid_list_mid {
-        my ($ctx, $listname, $mid) = @_;
-        my $ret = invalid_list($ctx, $listname, $mid);
+        my ($self, $ctx, $listname, $mid) = @_;
+        my $ret = invalid_list($self, $ctx, $listname, $mid);
         return $ret if $ret;
 
         $ctx->{mid} = $mid = uri_unescape($mid);
         if ($mid =~ /\A[a-f0-9]{40}\z/) {
+                # this is horiffically wasteful for legacy URLs:
                 if ($mid = mid2blob($ctx)) {
                         require Email::Simple;
                         use PublicInbox::MID qw/mid_clean/;
@@ -339,7 +346,7 @@ sub get_thread_atom {
 }
 
 sub legacy_redirects {
-        my ($ctx, $path_info) = @_;
+        my ($self, $ctx, $path_info) = @_;
 
         # single-message pages
         if ($path_info =~ m!$LISTNAME_RE/m/(\S+)/\z!o) {
@@ -384,13 +391,13 @@ sub legacy_redirects {
         # some Message-IDs have slashes in them and the HTTP server
         # may try to be clever and unescape them :<
         } elsif ($path_info =~ m!$LISTNAME_RE/(\S+/\S+)/$END_RE\z!o) {
-                msg_page($ctx, $1, $2, $3);
+                msg_page($self, $ctx, $1, $2, $3);
 
         # in case people leave off the trailing slash:
         } elsif ($path_info =~ m!$LISTNAME_RE/(\S+/\S+)/(f|T|t)\z!o) {
                 r301($ctx, $1, $2, $3 eq 't' ? 't/#u' : $3);
         } else {
-                r404();
+                $self->news_www->call($ctx->{cgi}->{env});
         }
 }
 
@@ -410,18 +417,18 @@ sub r301 {
 }
 
 sub msg_page {
-        my ($ctx, $list, $mid, $e) = @_;
-        unless (invalid_list_mid($ctx, $list, $mid)) {
-                '' eq $e and return get_mid_html($ctx);
-                't/' eq $e and return get_thread($ctx);
-                't.atom' eq $e and return get_thread_atom($ctx);
-                't.mbox' eq $e and return get_thread_mbox($ctx);
-                't.mbox.gz' eq $e and return get_thread_mbox($ctx, '.gz');
-                'T/' eq $e and return get_thread($ctx, 1);
-                'raw' eq $e and return get_mid_txt($ctx);
-                'f/' eq $e and return get_full_html($ctx);
-                'R/' eq $e and return get_reply_html($ctx);
-        }
+        my ($self, $ctx, $list, $mid, $e) = @_;
+        my $ret;
+        $ret = invalid_list_mid($self, $ctx, $list, $mid) and return $ret;
+        '' eq $e and return get_mid_html($ctx);
+        't/' eq $e and return get_thread($ctx);
+        't.atom' eq $e and return get_thread_atom($ctx);
+        't.mbox' eq $e and return get_thread_mbox($ctx);
+        't.mbox.gz' eq $e and return get_thread_mbox($ctx, '.gz');
+        'T/' eq $e and return get_thread($ctx, 1);
+        'raw' eq $e and return get_mid_txt($ctx);
+        'f/' eq $e and return get_full_html($ctx);
+        'R/' eq $e and return get_reply_html($ctx);
         r404($ctx);
 }
 
@@ -430,4 +437,12 @@ sub serve_git {
         PublicInbox::GitHTTPBackend::serve($cgi, $git, $path);
 }
 
+sub news_www {
+        my ($self) = @_;
+        my $nw = $self->{news_www};
+        return $nw if $nw;
+        require PublicInbox::NewsWWW;
+        $self->{news_www} = PublicInbox::NewsWWW->new($self->{pi_config});
+}
+
 1;