+ my %proxies;
+
+ if (defined $for_url) {
+ # We know which URL we're going to fetch, so we can choose
+ # whether it's going to go through a proxy or not.
+ #
+ # We reimplement http_proxy, https_proxy and no_proxy here, so
+ # that we are not relying on LWP implementing them exactly the
+ # same way we do.
+
+ eval q{use URI};
+ error($@) if $@;
+
+ my $proxy;
+ my $uri = URI->new($for_url);
+
+ if ($uri->scheme eq 'http') {
+ $proxy = $ENV{http_proxy};
+ # HTTP_PROXY is deliberately not implemented
+ # because the HTTP_* namespace is also used by CGI
+ }
+ elsif ($uri->scheme eq 'https') {
+ $proxy = $ENV{https_proxy};
+ $proxy = $ENV{HTTPS_PROXY} unless defined $proxy;
+ }
+ else {
+ $proxy = undef;
+ }
+
+ foreach my $var (qw(no_proxy NO_PROXY)) {
+ my $no_proxy = $ENV{$var};
+ if (defined $no_proxy) {
+ foreach my $domain (split /\s*,\s*/, $no_proxy) {
+ if ($domain =~ s/^\*?\.//) {
+ # no_proxy="*.example.com" or
+ # ".example.com": match suffix
+ # against .example.com
+ if ($uri->host =~ m/(^|\.)\Q$domain\E$/i) {
+ $proxy = undef;
+ }
+ }
+ else {
+ # no_proxy="example.com":
+ # match exactly example.com
+ if (lc $uri->host eq lc $domain) {
+ $proxy = undef;
+ }
+ }
+ }
+ }
+ }
+
+ if (defined $proxy) {
+ $proxies{$uri->scheme} = $proxy;
+ # Paranoia: make sure we can't bypass the proxy
+ $args{protocols_allowed} = [$uri->scheme];
+ }
+ }
+ else {
+ # The plugin doesn't know yet which URL(s) it's going to
+ # fetch, so we have to make some conservative assumptions.
+ my $http_proxy = $ENV{http_proxy};
+ my $https_proxy = $ENV{https_proxy};
+ $https_proxy = $ENV{HTTPS_PROXY} unless defined $https_proxy;
+
+ # We don't respect no_proxy here: if we are not using the
+ # paranoid user-agent, then we need to give the proxy the
+ # opportunity to reject undesirable requests.
+
+ # If we have one, we need the other: otherwise, neither
+ # LWPx::ParanoidAgent nor the proxy would have the
+ # opportunity to filter requests for the other protocol.
+ if (defined $https_proxy && defined $http_proxy) {
+ %proxies = (http => $http_proxy, https => $https_proxy);
+ }
+ elsif (defined $https_proxy) {
+ %proxies = (http => $https_proxy, https => $https_proxy);
+ }
+ elsif (defined $http_proxy) {
+ %proxies = (http => $http_proxy, https => $http_proxy);
+ }
+
+ }
+
+ if (scalar keys %proxies) {
+ # The configured proxy is responsible for deciding which
+ # URLs are acceptable to fetch and which URLs are not.
+ my $ua = LWP::UserAgent->new(%args);
+ foreach my $scheme (@{$ua->protocols_allowed}) {
+ unless ($proxies{$scheme}) {
+ error "internal error: $scheme is allowed but has no proxy";
+ }
+ }
+ # We can't pass the proxies in %args because that only
+ # works since LWP 6.24.
+ foreach my $scheme (keys %proxies) {
+ $ua->proxy($scheme, $proxies{$scheme});
+ }
+ return $ua;
+ }
+
+ eval q{use LWPx::ParanoidAgent};
+ if ($@) {
+ print STDERR "warning: installing LWPx::ParanoidAgent is recommended\n";
+ return LWP::UserAgent->new(%args);
+ }
+ return LWPx::ParanoidAgent->new(%args);