From 6617790c18e4048671d64d03212cfe84b960f376 Mon Sep 17 00:00:00 2001
From: murgatroid99 <mlumish@google.com>
Date: Tue, 18 Jul 2017 18:00:38 -0700
Subject: [PATCH] Add SO_REUSEPORT support to uv iomgr code

---
 src/core/lib/iomgr/sockaddr_utils.c |  5 +++++
 src/core/lib/iomgr/sockaddr_utils.h |  2 ++
 src/core/lib/iomgr/tcp_server_uv.c  | 14 +++++++++++++-
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/core/lib/iomgr/sockaddr_utils.c b/src/core/lib/iomgr/sockaddr_utils.c
index 99dc2f1c78a..3f4145d104e 100644
--- a/src/core/lib/iomgr/sockaddr_utils.c
+++ b/src/core/lib/iomgr/sockaddr_utils.c
@@ -220,6 +220,11 @@ const char *grpc_sockaddr_get_uri_scheme(
   return NULL;
 }
 
+int grpc_sockaddr_get_family(const grpc_resolved_address *resolved_addr) {
+  const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
+  return addr->sa_family;
+}
+
 int grpc_sockaddr_get_port(const grpc_resolved_address *resolved_addr) {
   const struct sockaddr *addr = (const struct sockaddr *)resolved_addr->addr;
   switch (addr->sa_family) {
diff --git a/src/core/lib/iomgr/sockaddr_utils.h b/src/core/lib/iomgr/sockaddr_utils.h
index 7692b969f2b..a589a197054 100644
--- a/src/core/lib/iomgr/sockaddr_utils.h
+++ b/src/core/lib/iomgr/sockaddr_utils.h
@@ -75,4 +75,6 @@ char *grpc_sockaddr_to_uri(const grpc_resolved_address *addr);
 /* Returns the URI scheme corresponding to \a addr */
 const char *grpc_sockaddr_get_uri_scheme(const grpc_resolved_address *addr);
 
+int grpc_sockaddr_get_family(const grpc_resolved_address *resolved_addr);
+
 #endif /* GRPC_CORE_LIB_IOMGR_SOCKADDR_UTILS_H */
diff --git a/src/core/lib/iomgr/tcp_server_uv.c b/src/core/lib/iomgr/tcp_server_uv.c
index 2ab836cc34d..079c9135796 100644
--- a/src/core/lib/iomgr/tcp_server_uv.c
+++ b/src/core/lib/iomgr/tcp_server_uv.c
@@ -316,6 +316,7 @@ grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s,
   unsigned port_index = 0;
   int status;
   grpc_error *error = GRPC_ERROR_NONE;
+  int family;
 
   if (s->tail != NULL) {
     port_index = s->tail->port_index + 1;
@@ -353,7 +354,18 @@ grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s,
   }
 
   handle = gpr_malloc(sizeof(uv_tcp_t));
-  status = uv_tcp_init(uv_default_loop(), handle);
+
+  family = grpc_sockaddr_get_family(addr);
+  status = uv_tcp_init_ex(uv_default_loop(), handle, (unsigned int)family);
+#if defined(GPR_LINUX) && defined(SO_REUSEPORT)
+  if (family == AF_INET || family == AF_INET6) {
+    int fd;
+    uv_fileno((uv_handle_t *)handle, &fd);
+    int enable = 1;
+    setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &enable, sizeof(enable));
+  }
+#endif /* GPR_LINUX && SO_REUSEPORT */
+
   if (status == 0) {
     error = add_socket_to_server(s, handle, addr, port_index, &sp);
   } else {