circuit: Implement haproxy

3 files changed, 62 insertions, 1 deletions

diff --git a/src/core/proto/.may_include b/src/core/proto/.may_include
index c1647a5cf9..a66c3f83a6 100644
--- a/src/core/proto/.may_include
+++ b/src/core/proto/.may_include
@@ -4,7 +4,11 @@ orconfig.h
 
 lib/crypt_ops/*.h
 lib/buf/*.h
+lib/malloc/*.h
+lib/string/*.h
+
+lib/net/address.h
 
 trunnel/*.h
 
-core/proto/*.h
\ No newline at end of file
+core/proto/*.h
diff --git a/src/core/proto/proto_haproxy.c b/src/core/proto/proto_haproxy.c
new file mode 100644
index 0000000000..856f2ab152
--- /dev/null
+++ b/src/core/proto/proto_haproxy.c
@@ -0,0 +1,45 @@
+/* Copyright (c) 2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#define PROTO_HAPROXY_PRIVATE
+#include "lib/malloc/malloc.h"
+#include "lib/net/address.h"
+#include "lib/string/printf.h"
+#include "core/proto/proto_haproxy.h"
+
+/** Return a newly allocated PROXY header null-terminated string. Returns NULL
+ * if addr_port->addr is incompatible with the proxy protocol.
+ */
+char *
+haproxy_format_proxy_header_line(const tor_addr_port_t *addr_port)
+{
+  tor_assert(addr_port);
+
+  sa_family_t family = tor_addr_family(&addr_port->addr);
+  const char *family_string = NULL;
+  const char *src_addr_string = NULL;
+
+  switch (family) {
+    case AF_INET:
+      family_string = "TCP4";
+      src_addr_string = "0.0.0.0";
+      break;
+    case AF_INET6:
+      family_string = "TCP6";
+      src_addr_string = "::";
+      break;
+    default:
+      /* Unknown family. */
+      return NULL;
+  }
+
+  char *buf;
+  char addrbuf[TOR_ADDR_BUF_LEN];
+
+  tor_addr_to_str(addrbuf, &addr_port->addr, sizeof(addrbuf), 0);
+
+  tor_asprintf(&buf, "PROXY %s %s %s 0 %d\r\n", family_string, src_addr_string,
+                                                addrbuf, addr_port->port);
+
+  return buf;
+}
diff --git a/src/core/proto/proto_haproxy.h b/src/core/proto/proto_haproxy.h
new file mode 100644
index 0000000000..fd4240f5dd
--- /dev/null
+++ b/src/core/proto/proto_haproxy.h
@@ -0,0 +1,12 @@
+/* Copyright (c) 2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef TOR_PROTO_HAPROXY_H
+#define TOR_PROTO_HAPROXY_H
+
+struct tor_addr_port_t;
+
+char *haproxy_format_proxy_header_line(
+                                    const struct tor_addr_port_t *addr_port);
+
+#endif /* !defined(TOR_PROTO_HAPROXY_H) */