From f7db7a691c3f532cf60886312459f2baea755283 Mon Sep 17 00:00:00 2001
From: Shawn Landden <shawnlandden@gmail.com>
Date: Mon, 8 Jul 2013 18:28:14 +0000
Subject: [PATCH] basic SO_REUSEPORT support

---
 man/systemd.socket.xml | 11 +++++++++++
 src/core/dbus-socket.c |  2 ++
 src/core/socket.c      | 11 +++++++++++
 src/core/socket.h      |  1 +
 src/shared/missing.h   |  4 ++++
 5 files changed, 29 insertions(+)

diff --git a/man/systemd.socket.xml b/man/systemd.socket.xml
index 0a2d86996..2e1fb7cea 100644
--- a/man/systemd.socket.xml
+++ b/man/systemd.socket.xml
@@ -504,6 +504,17 @@
                                 for details.</para></listitem>
                         </varlistentry>
 
+                        <varlistentry>
+                                <term><varname>ReusePort=</varname></term>
+                                <listitem><para>Takes a boolean
+                                value. If true allows multiple bind()s
+                                to this TCP or UDP port.  This
+                                controls the SO_REUSEPORT socket
+                                option.  See
+                                <citerefentry><refentrytitle>socket</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+                                for details.</para></listitem>
+                        </varlistentry>
+
                         <varlistentry>
                                 <term><varname>SmackLabel=</varname></term>
                                 <term><varname>SmackLabelIPIn=</varname></term>
diff --git a/src/core/dbus-socket.c b/src/core/dbus-socket.c
index da317edb8..30c4b6302 100644
--- a/src/core/dbus-socket.c
+++ b/src/core/dbus-socket.c
@@ -67,6 +67,7 @@
         "  <property name=\"MessageQueueMessageSize\" type=\"x\" access=\"read\"/>\n" \
         "  <property name=\"Listen\" type=\"a(ss)\" access=\"read\"/>\n"    \
         "  <property name=\"Result\" type=\"s\" access=\"read\"/>\n"    \
+        "  <property name=\"ReusePort\" type=\"b\" access=\"read\"/>\n" \
         "  <property name=\"SmackLabel\" type=\"s\" access=\"read\"/>\n" \
         "  <property name=\"SmackLabelIPIn\" type=\"s\" access=\"read\"/>\n" \
         "  <property name=\"SmackLabelIPOut\" type=\"s\" access=\"read\"/>\n" \
@@ -194,6 +195,7 @@ static const BusProperty bus_socket_properties[] = {
         { "MessageQueueMaxMessages", bus_property_append_long, "x", offsetof(Socket, mq_maxmsg)       },
         { "MessageQueueMessageSize", bus_property_append_long, "x", offsetof(Socket, mq_msgsize)      },
         { "Result",         bus_socket_append_socket_result,   "s", offsetof(Socket, result)          },
+        { "ReusePort",      bus_property_append_bool,          "b", offsetof(Socket, reuseport)       },
         { "SmackLabel",     bus_property_append_string,        "s", offsetof(Socket, smack),          true },
         { "SmackLabelIPIn", bus_property_append_string,        "s", offsetof(Socket, smack_ip_in),    true },
         { "SmackLabelIPOut",bus_property_append_string,        "s", offsetof(Socket, smack_ip_out),   true },
diff --git a/src/core/socket.c b/src/core/socket.c
index 2def0c9ea..cf88bae9d 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -536,6 +536,11 @@ static void socket_dump(Unit *u, FILE *f, const char *prefix) {
                         "%sMessageQueueMessageSize: %li\n",
                         prefix, s->mq_msgsize);
 
+        if (s->reuseport)
+                fprintf(f,
+                        "%sReusePort: %s\n",
+                         prefix, yes_no(s->reuseport));
+
         if (s->smack)
                 fprintf(f,
                         "%sSmackLabel: %s\n",
@@ -792,6 +797,12 @@ static void socket_apply_socket_options(Socket *s, int fd) {
                 if (setsockopt(fd, SOL_TCP, TCP_CONGESTION, s->tcp_congestion, strlen(s->tcp_congestion)+1) < 0)
                         log_warning_unit(UNIT(s)->id, "TCP_CONGESTION failed: %m");
 
+        if (s->reuseport) {
+                int b = s->reuseport;
+                if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &b, sizeof(b)))
+                        log_warning_unit(UNIT(s)->id, "SO_REUSEPORT failed: %m");
+        }
+
 #ifdef HAVE_SMACK
         if (s->smack_ip_in)
                 if (fsetxattr(fd, "security.SMACK64IPIN", s->smack_ip_in, strlen(s->smack_ip_in), 0) < 0)
diff --git a/src/core/socket.h b/src/core/socket.h
index 15942c1c9..8f9dfdbfb 100644
--- a/src/core/socket.h
+++ b/src/core/socket.h
@@ -144,6 +144,7 @@ struct Socket {
         size_t pipe_size;
         char *bind_to_device;
         char *tcp_congestion;
+        bool reuseport;
         long mq_maxmsg;
         long mq_msgsize;
 
diff --git a/src/shared/missing.h b/src/shared/missing.h
index 24a8392b2..534b3ccd4 100644
--- a/src/shared/missing.h
+++ b/src/shared/missing.h
@@ -266,3 +266,7 @@ static inline int name_to_handle_at(int fd, const char *name, struct file_handle
 #ifndef TFD_TIMER_CANCEL_ON_SET
 #define TFD_TIMER_CANCEL_ON_SET (1 << 1)
 #endif
+
+#ifndef SO_REUSEPORT
+#define SO_REUSEPORT 15
+#endif
-- 
2.30.2