1 files changed, 51 insertions, 3 deletions

diff --git a/transport.c b/transport.c
index 2d51348f3f..37e4f5e42c 100644
--- a/transport.c
+++ b/transport.c
@@ -15,6 +15,7 @@
 #include "submodule.h"
 #include "string-list.h"
 #include "sha1-array.h"
+#include "sigchain.h"
 
 /* rsync support */
 
@@ -915,6 +916,42 @@ static int external_specification_len(const char *url)
 	return strchr(url, ':') - url;
 }
 
+static const struct string_list *protocol_whitelist(void)
+{
+	static int enabled = -1;
+	static struct string_list allowed = STRING_LIST_INIT_DUP;
+
+	if (enabled < 0) {
+		const char *v = getenv("GIT_ALLOW_PROTOCOL");
+		if (v) {
+			string_list_split(&allowed, v, ':', -1);
+			string_list_sort(&allowed);
+			enabled = 1;
+		} else {
+			enabled = 0;
+		}
+	}
+
+	return enabled ? &allowed : NULL;
+}
+
+int is_transport_allowed(const char *type)
+{
+	const struct string_list *allowed = protocol_whitelist();
+	return !allowed || string_list_has_string(allowed, type);
+}
+
+void transport_check_allowed(const char *type)
+{
+	if (!is_transport_allowed(type))
+		die("transport '%s' not allowed", type);
+}
+
+int transport_restrict_protocols(void)
+{
+	return !!protocol_whitelist();
+}
+
 struct transport *transport_get(struct remote *remote, const char *url)
 {
 	const char *helper;
@@ -946,12 +983,14 @@ struct transport *transport_get(struct remote *remote, const char *url)
 	if (helper) {
 		transport_helper_init(ret, helper);
 	} else if (starts_with(url, "rsync:")) {
+		transport_check_allowed("rsync");
 		ret->get_refs_list = get_refs_via_rsync;
 		ret->fetch = fetch_objs_via_rsync;
 		ret->push = rsync_transport_push;
 		ret->smart_options = NULL;
 	} else if (url_is_local_not_ssh(url) && is_file(url) && is_bundle(url, 1)) {
 		struct bundle_transport_data *data = xcalloc(1, sizeof(*data));
+		transport_check_allowed("file");
 		ret->data = data;
 		ret->get_refs_list = get_refs_from_bundle;
 		ret->fetch = fetch_refs_from_bundle;
@@ -963,7 +1002,10 @@ struct transport *transport_get(struct remote *remote, const char *url)
 		|| starts_with(url, "ssh://")
 		|| starts_with(url, "git+ssh://")
 		|| starts_with(url, "ssh+git://")) {
-		/* These are builtin smart transports. */
+		/*
+		 * These are builtin smart transports; "allowed" transports
+		 * will be checked individually in git_connect.
+		 */
 		struct git_transport_data *data = xcalloc(1, sizeof(*data));
 		ret->data = data;
 		ret->set_option = NULL;
@@ -1085,6 +1127,8 @@ static int run_pre_push_hook(struct transport *transport,
 		return -1;
 	}
 
+	sigchain_push(SIGPIPE, SIG_IGN);
+
 	strbuf_init(&buf, 256);
 
 	for (r = remote_refs; r; r = r->next) {
@@ -1098,8 +1142,10 @@ static int run_pre_push_hook(struct transport *transport,
 			 r->peer_ref->name, sha1_to_hex(r->new_sha1),
 			 r->name, sha1_to_hex(r->old_sha1));
 
-		if (write_in_full(proc.in, buf.buf, buf.len) != buf.len) {
-			ret = -1;
+		if (write_in_full(proc.in, buf.buf, buf.len) < 0) {
+			/* We do not mind if a hook does not read all refs. */
+			if (errno != EPIPE)
+				ret = -1;
 			break;
 		}
 	}
@@ -1110,6 +1156,8 @@ static int run_pre_push_hook(struct transport *transport,
 	if (!ret)
 		ret = x;
 
+	sigchain_pop(SIGPIPE);
+
 	x = finish_command(&proc);
 	if (!ret)
 		ret = x;