Allow configuring DSCP on controller and manager connections.

The changes allow the user to specify a separate dscp value for the
controller connection and the manager connection. The value will take
effect on resetting the connections. If no value is specified a default
value of 192 is chosen for each of the connections.

Feature #10074
Requested-by: Rajiv Ramanathan <rramanathan@nicira.com>
Signed-off-by: Mehak Mahajan <mmahajan@nicira.com>

20 files changed, 176 insertions, 62 deletions

diff --git a/lib/jsonrpc.c b/lib/jsonrpc.c
index 09b10711f..fa3362d17 100644
--- a/lib/jsonrpc.c
+++ b/lib/jsonrpc.c
@@ -60,19 +60,20 @@ static void jsonrpc_error(struct jsonrpc *, int error);
 /* This is just the same as stream_open() except that it uses the default
  * JSONRPC ports if none is specified. */
 int
-jsonrpc_stream_open(const char *name, struct stream **streamp)
+jsonrpc_stream_open(const char *name, struct stream **streamp, uint8_t dscp)
 {
     return stream_open_with_default_ports(name, JSONRPC_TCP_PORT,
-                                          JSONRPC_SSL_PORT, streamp);
+                                          JSONRPC_SSL_PORT, streamp,
+                                          dscp);
 }
 
 /* This is just the same as pstream_open() except that it uses the default
  * JSONRPC ports if none is specified. */
 int
-jsonrpc_pstream_open(const char *name, struct pstream **pstreamp)
+jsonrpc_pstream_open(const char *name, struct pstream **pstreamp, uint8_t dscp)
 {
     return pstream_open_with_default_ports(name, JSONRPC_TCP_PORT,
-                                           JSONRPC_SSL_PORT, pstreamp);
+                                           JSONRPC_SSL_PORT, pstreamp, dscp);
 }
 
 /* Returns a new JSON-RPC stream that uses 'stream' for input and output.  The
@@ -825,12 +826,14 @@ jsonrpc_session_connect(struct jsonrpc_session *s)
 
     jsonrpc_session_disconnect(s);
     if (!reconnect_is_passive(s->reconnect)) {
-        error = jsonrpc_stream_open(name, &s->stream);
+        error = jsonrpc_stream_open(name, &s->stream,
+                                    reconnect_get_dscp(s->reconnect));
         if (!error) {
             reconnect_connecting(s->reconnect, time_msec());
         }
     } else {
-        error = s->pstream ? 0 : jsonrpc_pstream_open(name, &s->pstream);
+        error = s->pstream ? 0 : jsonrpc_pstream_open(name, &s->pstream,
+                                        reconnect_get_dscp(s->reconnect));
         if (!error) {
             reconnect_listening(s->reconnect, time_msec());
         }
@@ -1041,3 +1044,10 @@ jsonrpc_session_set_probe_interval(struct jsonrpc_session *s,
 {
     reconnect_set_probe_interval(s->reconnect, probe_interval);
 }
+
+void
+jsonrpc_session_set_dscp(struct jsonrpc_session *s,
+                         uint8_t dscp)
+{
+    reconnect_set_dscp(s->reconnect, dscp);
+}
diff --git a/lib/jsonrpc.h b/lib/jsonrpc.h
index ff04a547e..16131d333 100644
--- a/lib/jsonrpc.h
+++ b/lib/jsonrpc.h
@@ -22,6 +22,7 @@
 
 #include <stdbool.h>
 #include <stddef.h>
+#include "openvswitch/types.h"
 
 struct json;
 struct jsonrpc_msg;
@@ -38,8 +39,8 @@ struct stream;
 #define JSONRPC_TCP_PORT 6632
 #define JSONRPC_SSL_PORT 6632
 
-int jsonrpc_stream_open(const char *name, struct stream **);
-int jsonrpc_pstream_open(const char *name, struct pstream **);
+int jsonrpc_stream_open(const char *name, struct stream **, uint8_t dscp);
+int jsonrpc_pstream_open(const char *name, struct pstream **, uint8_t dscp);
 
 struct jsonrpc *jsonrpc_open(struct stream *);
 void jsonrpc_close(struct jsonrpc *);
@@ -123,5 +124,7 @@ void jsonrpc_session_set_max_backoff(struct jsonrpc_session *,
                                      int max_backofF);
 void jsonrpc_session_set_probe_interval(struct jsonrpc_session *,
                                         int probe_interval);
+void jsonrpc_session_set_dscp(struct jsonrpc_session *,
+                              uint8_t dscp);
 
 #endif /* jsonrpc.h */
diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index a5e6d3663..d2a5c7acc 100644
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -26,7 +26,6 @@
 #include <linux/gen_stats.h>
 #include <linux/if_ether.h>
 #include <linux/if_tun.h>
-#include <linux/ip.h>
 #include <linux/types.h>
 #include <linux/ethtool.h>
 #include <linux/mii.h>
diff --git a/lib/rconn.c b/lib/rconn.c
index f6d85a7bd..56a7e1976 100644
--- a/lib/rconn.c
+++ b/lib/rconn.c
@@ -121,6 +121,7 @@ struct rconn {
      * attempt to the next. */
     ovs_be32 local_ip, remote_ip;
     ovs_be16 remote_port;
+    uint8_t dscp;
 
     /* Messages sent or received are copied to the monitor connections. */
 #define MAX_MONITORS 8
@@ -160,7 +161,7 @@ static bool rconn_logging_connection_attempts__(const struct rconn *);
  * The new rconn is initially unconnected.  Use rconn_connect() or
  * rconn_connect_unreliably() to connect it. */
 struct rconn *
-rconn_create(int probe_interval, int max_backoff)
+rconn_create(int probe_interval, int max_backoff, uint8_t dscp)
 {
     struct rconn *rc = xzalloc(sizeof *rc);
 
@@ -194,6 +195,7 @@ rconn_create(int probe_interval, int max_backoff)
     rc->total_time_connected = 0;
 
     rconn_set_probe_interval(rc, probe_interval);
+    rconn_set_dscp(rc, dscp);
 
     rc->n_monitors = 0;
 
@@ -219,6 +221,12 @@ rconn_get_max_backoff(const struct rconn *rc)
 }
 
 void
+rconn_set_dscp(struct rconn *rc, uint8_t dscp)
+{
+    rc->dscp = dscp;
+}
+
+void
 rconn_set_probe_interval(struct rconn *rc, int probe_interval)
 {
     rc->probe_interval = probe_interval ? MAX(5, probe_interval) : 0;
@@ -335,7 +343,7 @@ reconnect(struct rconn *rc)
         VLOG_INFO("%s: connecting...", rc->name);
     }
     rc->n_attempted_connections++;
-    retval = vconn_open(rc->target, OFP10_VERSION, &rc->vconn);
+    retval = vconn_open(rc->target, OFP10_VERSION, &rc->vconn, rc->dscp);
     if (!retval) {
         rc->remote_ip = vconn_get_remote_ip(rc->vconn);
         rc->local_ip = vconn_get_local_ip(rc->vconn);
diff --git a/lib/rconn.h b/lib/rconn.h
index d0326e65a..eea054f37 100644
--- a/lib/rconn.h
+++ b/lib/rconn.h
@@ -37,8 +37,9 @@
 struct vconn;
 struct rconn_packet_counter;
 
-struct rconn *rconn_create(int inactivity_probe_interval, int max_backoff);
-
+struct rconn *rconn_create(int inactivity_probe_interval,
+			   int max_backoff, uint8_t dscp);
+void rconn_set_dscp(struct rconn *rc, uint8_t dscp);
 void rconn_set_max_backoff(struct rconn *, int max_backoff);
 int rconn_get_max_backoff(const struct rconn *);
 void rconn_set_probe_interval(struct rconn *, int inactivity_probe_interval);
diff --git a/lib/reconnect.c b/lib/reconnect.c
index c16901623..7737fcf7e 100644
--- a/lib/reconnect.c
+++ b/lib/reconnect.c
@@ -54,6 +54,8 @@ struct reconnect {
     bool passive;
     enum vlog_level info;       /* Used for informational messages. */
 
+    uint8_t dscp;
+
     /* State. */
     enum state state;
     long long int state_entered;
@@ -186,6 +188,14 @@ reconnect_get_probe_interval(const struct reconnect *fsm)
     return fsm->probe_interval;
 }
 
+/* Returns the dscp value used for establishing the connection between the
+ * manager and the database. */
+uint8_t
+reconnect_get_dscp(const struct reconnect *fsm)
+{
+    return fsm->dscp;
+}
+
 /* Limits the maximum number of times that 'fsm' will ask the client to try to
  * reconnect to 'max_tries'.  UINT_MAX (the default) means an unlimited number
  * of tries.
@@ -245,6 +255,14 @@ reconnect_set_probe_interval(struct reconnect *fsm, int probe_interval)
     fsm->probe_interval = probe_interval ? MAX(1000, probe_interval) : 0;
 }
 
+/* Sets the dscp value to be used for establishing a connection between the
+ * manager and the database. */
+void
+reconnect_set_dscp(struct reconnect *fsm, uint8_t dscp)
+{
+    fsm->dscp = dscp;
+}
+
 /* Returns true if 'fsm' is in passive mode, false if 'fsm' is in active mode
  * (the default). */
 bool
diff --git a/lib/reconnect.h b/lib/reconnect.h
index 997a03f21..9dfcfd7df 100644
--- a/lib/reconnect.h
+++ b/lib/reconnect.h
@@ -31,6 +31,7 @@
  * revisited later.) */
 
 #include <stdbool.h>
+#include "openvswitch/types.h"
 
 struct reconnect *reconnect_create(long long int now);
 void reconnect_destroy(struct reconnect *);
@@ -48,6 +49,7 @@ void reconnect_set_name(struct reconnect *, const char *name);
 int reconnect_get_min_backoff(const struct reconnect *);
 int reconnect_get_max_backoff(const struct reconnect *);
 int reconnect_get_probe_interval(const struct reconnect *);
+uint8_t reconnect_get_dscp(const struct reconnect *);
 
 void reconnect_set_max_tries(struct reconnect *, unsigned int max_tries);
 unsigned int reconnect_get_max_tries(struct reconnect *);
@@ -55,6 +57,7 @@ unsigned int reconnect_get_max_tries(struct reconnect *);
 void reconnect_set_backoff(struct reconnect *,
                            int min_backoff, int max_backoff);
 void reconnect_set_probe_interval(struct reconnect *, int probe_interval);
+void reconnect_set_dscp(struct reconnect *, uint8_t dscp);
 
 bool reconnect_is_passive(const struct reconnect *);
 void reconnect_set_passive(struct reconnect *, bool passive,
diff --git a/lib/socket-util.c b/lib/socket-util.c
index 37f8c9ad4..6554e9721 100644
--- a/lib/socket-util.c
+++ b/lib/socket-util.c
@@ -544,10 +544,13 @@ exit:
  * and stores -1 into '*fdp'.
  *
  * If 'sinp' is non-null, then on success the target address is stored into
- * '*sinp'. */
+ * '*sinp'.
+ *
+ * 'dscp'  If not DSCP_INVALID, its value becomes the DSCP bits in the IP
+ * headers for the new connection. */
 int
 inet_open_active(int style, const char *target, uint16_t default_port,
-                 struct sockaddr_in *sinp, int *fdp)
+                 struct sockaddr_in *sinp, int *fdp, uint8_t dscp)
 {
     struct sockaddr_in sin;
     int fd = -1;
@@ -571,6 +574,17 @@ inet_open_active(int style, const char *target, uint16_t default_port,
         goto exit_close;
     }
 
+    /* The socket options set here ensure that the TOS bits are set during
+     * the connection establishment.  If set after connect(), the handshake
+     * SYN frames will be sent with a TOS of 0. */
+    if (dscp != DSCP_INVALID) {
+        if (setsockopt(fd, IPPROTO_IP, IP_TOS, &dscp, sizeof dscp)) {
+            VLOG_ERR("%s: socket: %s", target, strerror(errno));
+            error = errno;
+            goto exit;
+        }
+    }
+
     /* Connect. */
     error = connect(fd, (struct sockaddr *) &sin, sizeof sin) == 0 ? 0 : errno;
     if (error == EINPROGRESS) {
@@ -663,10 +677,13 @@ exit:
  * negative errno value.
  *
  * If 'sinp' is non-null, then on success the bound address is stored into
- * '*sinp'. */
+ * '*sinp'.
+ *
+ * 'dscp'  If not DSCP_INVALID, its value becomes the DSCP bits in the IP
+ * headers for the new connection. */
 int
 inet_open_passive(int style, const char *target, int default_port,
-                  struct sockaddr_in *sinp)
+                  struct sockaddr_in *sinp, uint8_t dscp)
 {
     struct sockaddr_in sin;
     int fd = 0, error;
@@ -701,6 +718,17 @@ inet_open_passive(int style, const char *target, int default_port,
         goto error;
     }
 
+    /* The socket options set here ensure that the TOS bits are set during
+     * the connection establishment.  If set after connect(), the handshake
+     * SYN frames will be sent with a TOS of 0. */
+    if (dscp != DSCP_INVALID) {
+        if (setsockopt(fd, IPPROTO_IP, IP_TOS, &dscp, sizeof dscp)) {
+            VLOG_ERR("%s: socket: %s", target, strerror(errno));
+            error = errno;
+            goto error;
+        }
+    }
+
     /* Listen. */
     if (style == SOCK_STREAM && listen(fd, 10) < 0) {
         error = errno;
diff --git a/lib/socket-util.h b/lib/socket-util.h
index 422cea9c3..32c61e789 100644
--- a/lib/socket-util.h
+++ b/lib/socket-util.h
@@ -23,6 +23,7 @@
 #include <netinet/in.h>
 #include <stdbool.h>
 #include "openvswitch/types.h"
+#include <netinet/ip.h>
 
 int set_nonblocking(int fd);
 int get_max_fds(void);
@@ -46,12 +47,12 @@ int get_null_fd(void);
 bool inet_parse_active(const char *target, uint16_t default_port,
                        struct sockaddr_in *sinp);
 int inet_open_active(int style, const char *target, uint16_t default_port,
-                    struct sockaddr_in *sinp, int *fdp);
+		     struct sockaddr_in *sinp, int *fdp, uint8_t dscp);
 
 bool inet_parse_passive(const char *target, int default_port,
                         struct sockaddr_in *sinp);
 int inet_open_passive(int style, const char *target, int default_port,
-                      struct sockaddr_in *sinp);
+                      struct sockaddr_in *sinp, uint8_t dscp);
 
 int read_fully(int fd, void *, size_t, size_t *bytes_read);
 int write_fully(int fd, const void *, size_t, size_t *bytes_written);
@@ -63,4 +64,14 @@ void xpipe(int fds[2]);
 
 char *describe_fd(int fd);
 
+/* Default value of dscp bits for connection between controller and manager.
+ * Value of IPTOS_PREC_INTERNETCONTROL = 0xc0 which is defined
+ * in <netinet/ip.h> is used.  */
+#define DSCP_DEFAULT IPTOS_PREC_INTERNETCONTROL
+
+/* Invalid dscp value.  If the dscp value will not be used, the dscp value
+ * passed must be invalid.  Set to 0xFF as the TOS bits passed can only be
+ * 6 bits. */
+#define DSCP_INVALID 0xFF
+
 #endif /* socket-util.h */
diff --git a/lib/stream-provider.h b/lib/stream-provider.h
index 03bf777b6..77d0a1060 100644
--- a/lib/stream-provider.h
+++ b/lib/stream-provider.h
@@ -40,6 +40,7 @@ struct stream {
 void stream_init(struct stream *, const struct stream_class *,
                  int connect_status, const char *name);
 void stream_set_remote_ip(struct stream *, ovs_be32 remote_ip);
+void stream_set_dscp(struct stream *, uint8_t dscp);
 void stream_set_remote_port(struct stream *, ovs_be16 remote_port);
 void stream_set_local_ip(struct stream *, ovs_be32 local_ip);
 void stream_set_local_port(struct stream *, ovs_be16 local_port);
@@ -58,6 +59,10 @@ struct stream_class {
      * messages but must not be modified.
      *
      * 'suffix' is a copy of 'name' following the colon and may be modified.
+     * 'dscp' is the DSCP value that the new connection should use in the IP
+     * packets it sends.  (If no DSCP value should be set in the packet, dscp
+     * will be set to DSCP_INVALID.  If no DSCP value is specified, DSCP_DEFAULT
+     * value will be applied.)
      *
      * Returns 0 if successful, otherwise a positive errno value.  If
      * successful, stores a pointer to the new connection in '*streamp'.
@@ -66,7 +71,8 @@ struct stream_class {
      * If the connection cannot be completed immediately, it should return
      * EAGAIN (not EINPROGRESS, as returned by the connect system call) and
      * continue the connection in the background. */
-    int (*open)(const char *name, char *suffix, struct stream **streamp);
+    int (*open)(const char *name, char *suffix, struct stream **streamp,
+                uint8_t dscp);
 
     /* Closes 'stream' and frees associated memory. */
     void (*close)(struct stream *stream);
@@ -150,6 +156,10 @@ struct pstream_class {
      * useful for error messages but must not be modified.
      *
      * 'suffix' is a copy of 'name' following the colon and may be modified.
+     * 'dscp' is the DSCP value that the new connection should use in the IP
+     * packets it sends.  (If no DSCP value should be set in the packet, dscp
+     * will be set to DSCP_INVALID.  If no DSCP value is specified, DSCP_DEFAULT
+     * value will be applied.)
      *
      * Returns 0 if successful, otherwise a positive errno value.  If
      * successful, stores a pointer to the new connection in '*pstreamp'.
@@ -158,7 +168,8 @@ struct pstream_class {
      * completed immediately, it should return EAGAIN (not EINPROGRESS, as
      * returned by the connect system call) and continue the connection in the
      * background. */
-    int (*listen)(const char *name, char *suffix, struct pstream **pstreamp);
+    int (*listen)(const char *name, char *suffix, struct pstream **pstreamp,
+                  uint8_t dscp);
 
     /* Closes 'pstream' and frees associated memory. */
     void (*close)(struct pstream *pstream);
diff --git a/lib/stream-ssl.c b/lib/stream-ssl.c
index 22d4c99ae..5463388ea 100644
--- a/lib/stream-ssl.c
+++ b/lib/stream-ssl.c
@@ -204,8 +204,8 @@ want_to_poll_events(int want)
 
 static int
 new_ssl_stream(const char *name, int fd, enum session_type type,
-              enum ssl_state state, const struct sockaddr_in *remote,
-              struct stream **streamp)
+               enum ssl_state state, const struct sockaddr_in *remote,
+               struct stream **streamp)
 {
     struct sockaddr_in local;
     socklen_t local_len = sizeof local;
@@ -307,7 +307,7 @@ ssl_stream_cast(struct stream *stream)
 }
 
 static int
-ssl_open(const char *name, char *suffix, struct stream **streamp)
+ssl_open(const char *name, char *suffix, struct stream **streamp, uint8_t dscp)
 {
     struct sockaddr_in sin;
     int error, fd;
@@ -317,7 +317,8 @@ ssl_open(const char *name, char *suffix, struct stream **streamp)
         return error;
     }
 
-    error = inet_open_active(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin, &fd);
+    error = inet_open_active(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin, &fd,
+                             dscp);
     if (fd >= 0) {
         int state = error ? STATE_TCP_CONNECTING : STATE_SSL_CONNECTING;
         return new_ssl_stream(name, fd, CLIENT, state, &sin, streamp);
@@ -782,7 +783,8 @@ pssl_pstream_cast(struct pstream *pstream)
 }
 
 static int
-pssl_open(const char *name OVS_UNUSED, char *suffix, struct pstream **pstreamp)
+pssl_open(const char *name OVS_UNUSED, char *suffix, struct pstream **pstreamp,
+          uint8_t dscp)
 {
     struct pssl_pstream *pssl;
     struct sockaddr_in sin;
@@ -795,7 +797,7 @@ pssl_open(const char *name OVS_UNUSED, char *suffix, struct pstream **pstreamp)
         return retval;
     }
 
-    fd = inet_open_passive(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin);
+    fd = inet_open_passive(SOCK_STREAM, suffix, OFP_SSL_PORT, &sin, dscp);
     if (fd < 0) {
         return -fd;
     }
@@ -847,7 +849,7 @@ pssl_accept(struct pstream *pstream, struct stream **new_streamp)
         sprintf(strchr(name, '\0'), ":%"PRIu16, ntohs(sin.sin_port));
     }
     return new_ssl_stream(name, new_fd, SERVER, STATE_SSL_CONNECTING, &sin,
-                         new_streamp);
+                          new_streamp);
 }
 
 static void
diff --git a/lib/stream-tcp.c b/lib/stream-tcp.c
index 052ad8cb5..c7a2ee2e8 100644
--- a/lib/stream-tcp.c
+++ b/lib/stream-tcp.c
@@ -38,7 +38,7 @@ VLOG_DEFINE_THIS_MODULE(stream_tcp);
 
 static int
 new_tcp_stream(const char *name, int fd, int connect_status,
-              const struct sockaddr_in *remote, struct stream **streamp)
+               const struct sockaddr_in *remote, struct stream **streamp)
 {
     struct sockaddr_in local;
     socklen_t local_len = sizeof local;
@@ -70,12 +70,12 @@ new_tcp_stream(const char *name, int fd, int connect_status,
 }
 
 static int
-tcp_open(const char *name, char *suffix, struct stream **streamp)
+tcp_open(const char *name, char *suffix, struct stream **streamp, uint8_t dscp)
 {
     struct sockaddr_in sin;
     int fd, error;
 
-    error = inet_open_active(SOCK_STREAM, suffix, 0, &sin, &fd);
+    error = inet_open_active(SOCK_STREAM, suffix, 0, &sin, &fd, dscp);
     if (fd >= 0) {
         return new_tcp_stream(name, fd, error, &sin, streamp);
     } else {
@@ -102,13 +102,14 @@ static int ptcp_accept(int fd, const struct sockaddr *sa, size_t sa_len,
                        struct stream **streamp);
 
 static int
-ptcp_open(const char *name OVS_UNUSED, char *suffix, struct pstream **pstreamp)
+ptcp_open(const char *name OVS_UNUSED, char *suffix, struct pstream **pstreamp,
+          uint8_t dscp)
 {
     struct sockaddr_in sin;
     char bound_name[128];
     int fd;
 
-    fd = inet_open_passive(SOCK_STREAM, suffix, -1, &sin);
+    fd = inet_open_passive(SOCK_STREAM, suffix, -1, &sin, dscp);
     if (fd < 0) {
         return -fd;
     }
diff --git a/lib/stream-unix.c b/lib/stream-unix.c
index d2e8e8238..a9d76f257 100644
--- a/lib/stream-unix.c
+++ b/lib/stream-unix.c
@@ -40,7 +40,8 @@ VLOG_DEFINE_THIS_MODULE(stream_unix);
 /* Active UNIX socket. */
 
 static int
-unix_open(const char *name, char *suffix, struct stream **streamp)
+unix_open(const char *name, char *suffix, struct stream **streamp,
+          uint8_t dscp OVS_UNUSED)
 {
     const char *connect_path = suffix;
     int fd;
@@ -73,7 +74,7 @@ static int punix_accept(int fd, const struct sockaddr *sa, size_t sa_len,
 
 static int
 punix_open(const char *name OVS_UNUSED, char *suffix,
-           struct pstream **pstreamp)
+           struct pstream **pstreamp, uint8_t dscp OVS_UNUSED)
 {
     int fd, error;
 
diff --git a/lib/stream.c b/lib/stream.c
index 066de4e87..2f418c42a 100644
--- a/lib/stream.c
+++ b/lib/stream.c
@@ -194,7 +194,7 @@ stream_verify_name(const char *name)
  * stores a pointer to the new connection in '*streamp', otherwise a null
  * pointer.  */
 int
-stream_open(const char *name, struct stream **streamp)
+stream_open(const char *name, struct stream **streamp, uint8_t dscp)
 {
     const struct stream_class *class;
     struct stream *stream;
@@ -211,7 +211,7 @@ stream_open(const char *name, struct stream **streamp)
 
     /* Call class's "open" function. */
     suffix_copy = xstrdup(strchr(name, ':') + 1);
-    error = class->open(name, suffix_copy, &stream);
+    error = class->open(name, suffix_copy, &stream, dscp);
     free(suffix_copy);
     if (error) {
         goto error;
@@ -497,7 +497,7 @@ pstream_verify_name(const char *name)
  * stores a pointer to the new connection in '*pstreamp', otherwise a null
  * pointer.  */
 int
-pstream_open(const char *name, struct pstream **pstreamp)
+pstream_open(const char *name, struct pstream **pstreamp, uint8_t dscp)
 {
     const struct pstream_class *class;
     struct pstream *pstream;
@@ -514,7 +514,7 @@ pstream_open(const char *name, struct pstream **pstreamp)
 
     /* Call class's "open" function. */
     suffix_copy = xstrdup(strchr(name, ':') + 1);
-    error = class->listen(name, suffix_copy, &pstream);
+    error = class->listen(name, suffix_copy, &pstream, dscp);
     free(suffix_copy);
     if (error) {
         goto error;
@@ -682,7 +682,8 @@ int
 stream_open_with_default_ports(const char *name_,
                                uint16_t default_tcp_port,
                                uint16_t default_ssl_port,
-                               struct stream **streamp)
+                               struct stream **streamp,
+                               uint8_t dscp)
 {
     char *name;
     int error;
@@ -694,7 +695,7 @@ stream_open_with_default_ports(const char *name_,
     } else {
         name = xstrdup(name_);
     }
-    error = stream_open(name, streamp);
+    error = stream_open(name, streamp, dscp);
     free(name);
 
     return error;
@@ -707,7 +708,8 @@ int
 pstream_open_with_default_ports(const char *name_,
                                 uint16_t default_ptcp_port,
                                 uint16_t default_pssl_port,
-                                struct pstream **pstreamp)
+                                struct pstream **pstreamp,
+                                uint8_t dscp)
 {
     char *name;
     int error;
@@ -719,7 +721,7 @@ pstream_open_with_default_ports(const char *name_,
     } else {
         name = xstrdup(name_);
     }
-    error = pstream_open(name, pstreamp);
+    error = pstream_open(name, pstreamp, dscp);
     free(name);
 
     return error;
diff --git a/lib/stream.h b/lib/stream.h
index 5c111f999..c1f3adb6b 100644
--- a/lib/stream.h
+++ b/lib/stream.h
@@ -32,7 +32,7 @@ void stream_usage(const char *name, bool active, bool passive, bool bootstrap);
 
 /* Bidirectional byte streams. */
 int stream_verify_name(const char *name);
-int stream_open(const char *name, struct stream **);
+int stream_open(const char *name, struct stream **, uint8_t dscp);
 int stream_open_block(int error, struct stream **);
 void stream_close(struct stream *);
 const char *stream_get_name(const struct stream *);
@@ -59,7 +59,7 @@ void stream_send_wait(struct stream *);
 
 /* Passive streams: listeners for incoming stream connections. */
 int pstream_verify_name(const char *name);
-int pstream_open(const char *name, struct pstream **);
+int pstream_open(const char *name, struct pstream **, uint8_t dscp);
 const char *pstream_get_name(const struct pstream *);
 void pstream_close(struct pstream *);
 int pstream_accept(struct pstream *, struct stream **);
@@ -71,11 +71,13 @@ void pstream_wait(struct pstream *);
 int stream_open_with_default_ports(const char *name,
                                    uint16_t default_tcp_port,
                                    uint16_t default_ssl_port,
-                                   struct stream **);
+                                   struct stream **,
+                                   uint8_t dscp);
 int pstream_open_with_default_ports(const char *name,
                                     uint16_t default_ptcp_port,
                                     uint16_t default_pssl_port,
-                                    struct pstream **);
+                                    struct pstream **,
+                                    uint8_t dscp);
 bool stream_parse_target_with_default_ports(const char *target,
                                            uint16_t default_tcp_port,
                                            uint16_t default_ssl_port,
diff --git a/lib/unixctl.c b/lib/unixctl.c
index d8974c9e4..e40f17314 100644
--- a/lib/unixctl.c
+++ b/lib/unixctl.c
@@ -221,7 +221,7 @@ unixctl_server_create(const char *path, struct unixctl_server **serverp)
                                program_name, (long int) getpid());
     }
 
-    error = pstream_open(punix_path, &listener);
+    error = pstream_open(punix_path, &listener, DSCP_INVALID);
     if (error) {
         ovs_error(error, "could not initialize control socket %s", punix_path);
         goto exit;
@@ -422,7 +422,8 @@ unixctl_client_create(const char *path, struct jsonrpc **client)
 
     abs_path = abs_file_name(ovs_rundir(), path);
     unix_path = xasprintf("unix:%s", abs_path);
-    error = stream_open_block(stream_open(unix_path, &stream), &stream);
+    error = stream_open_block(stream_open(unix_path, &stream, DSCP_DEFAULT),
+                              &stream);
     free(unix_path);
     free(abs_path);
 
diff --git a/lib/vconn-provider.h b/lib/vconn-provider.h
index 682a593c8..43d2072e2 100644
--- a/lib/vconn-provider.h
+++ b/lib/vconn-provider.h
@@ -62,6 +62,10 @@ struct vconn_class {
      * useful for error messages but must not be modified.
      *
      * 'suffix' is a copy of 'name' following the colon and may be modified.
+     * 'dscp' is the DSCP value that the new connection should use in the IP
+     * packets it sends.  (If no DSCP value should be set in the packet, dscp
+     * will be set to DSCP_INVALID.  If no DSCP value is specified, DSCP_DEFAULT
+     * value will be applied.)
      *
      * Returns 0 if successful, otherwise a positive errno value.  If
      * successful, stores a pointer to the new connection in '*vconnp'.
@@ -70,7 +74,8 @@ struct vconn_class {
      * If the connection cannot be completed immediately, it should return
      * EAGAIN (not EINPROGRESS, as returned by the connect system call) and
      * continue the connection in the background. */
-    int (*open)(const char *name, char *suffix, struct vconn **vconnp);
+    int (*open)(const char *name, char *suffix, struct vconn **vconnp,
+                uint8_t dscp);
 
     /* Closes 'vconn' and frees associated memory. */
     void (*close)(struct vconn *vconn);
@@ -149,6 +154,10 @@ struct pvconn_class {
      * is useful for error messages but must not be modified.
      *
      * 'suffix' is a copy of 'name' following the colon and may be modified.
+     * 'dscp' is the DSCP value that the new connection should use in the IP
+     * packets it sends.  (If no DSCP value should be set in the packet, dscp
+     * will be set to DSCP_INVALID.  If no DSCP value is specified, DSCP_DEFAULT
+     * value will be applied.)
      *
      * Returns 0 if successful, otherwise a positive errno value.  If
      * successful, stores a pointer to the new connection in '*pvconnp'.
@@ -157,7 +166,8 @@ struct pvconn_class {
      * completed immediately, it should return EAGAIN (not EINPROGRESS, as
      * returned by the connect system call) and continue the connection in the
      * background. */
-    int (*listen)(const char *name, char *suffix, struct pvconn **pvconnp);
+    int (*listen)(const char *name, char *suffix, struct pvconn **pvconnp,
+                  uint8_t dscp);
 
     /* Closes 'pvconn' and frees associated memory. */
     void (*close)(struct pvconn *pvconn);
diff --git a/lib/vconn-stream.c b/lib/vconn-stream.c
index a9890b594..03e588185 100644
--- a/lib/vconn-stream.c
+++ b/lib/vconn-stream.c
@@ -78,13 +78,13 @@ vconn_stream_new(struct stream *stream, int connect_status)
  * Returns 0 if successful, otherwise a positive errno value. */
 static int
 vconn_stream_open(const char *name, char *suffix OVS_UNUSED,
-                  struct vconn **vconnp)
+                  struct vconn **vconnp, uint8_t dscp)
 {
     struct stream *stream;
     int error;
 
     error = stream_open_with_default_ports(name, OFP_TCP_PORT, OFP_SSL_PORT,
-                                           &stream);
+                                           &stream, dscp);
     if (!error) {
         error = stream_connect(stream);
         if (!error || error == EAGAIN) {
@@ -311,14 +311,14 @@ pvconn_pstream_cast(struct pvconn *pvconn)
  * implementation never fails.) */
 static int
 pvconn_pstream_listen(const char *name, char *suffix OVS_UNUSED,
-                      struct pvconn **pvconnp)
+                      struct pvconn **pvconnp, uint8_t dscp)
 {
     struct pvconn_pstream *ps;
     struct pstream *pstream;
     int error;
 
     error = pstream_open_with_default_ports(name, OFP_TCP_PORT, OFP_SSL_PORT,
-                                            &pstream);
+                                            &pstream, dscp);
     if (error) {
         return error;
     }
diff --git a/lib/vconn.c b/lib/vconn.c
index f0be46a3d..4d04c8338 100644
--- a/lib/vconn.c
+++ b/lib/vconn.c
@@ -38,6 +38,7 @@
 #include "random.h"
 #include "util.h"
 #include "vlog.h"
+#include "socket-util.h"
 
 VLOG_DEFINE_THIS_MODULE(vconn);
 
@@ -219,7 +220,8 @@ vconn_verify_name(const char *name)
  * stores a pointer to the new connection in '*vconnp', otherwise a null
  * pointer.  */
 int
-vconn_open(const char *name, int min_version, struct vconn **vconnp)
+vconn_open(const char *name, int min_version, struct vconn **vconnp,
+           uint8_t dscp)
 {
     struct vconn_class *class;
     struct vconn *vconn;
@@ -237,7 +239,7 @@ vconn_open(const char *name, int min_version, struct vconn **vconnp)
 
     /* Call class's "open" function. */
     suffix_copy = xstrdup(strchr(name, ':') + 1);
-    error = class->open(name, suffix_copy, &vconn);
+    error = class->open(name, suffix_copy, &vconn, dscp);
     free(suffix_copy);
     if (error) {
         goto error;
@@ -282,7 +284,7 @@ vconn_open_block(const char *name, int min_version, struct vconn **vconnp)
 
     fatal_signal_run();
 
-    error = vconn_open(name, min_version, &vconn);
+    error = vconn_open(name, min_version, &vconn, DSCP_DEFAULT);
     if (!error) {
         while ((error = vconn_connect(vconn)) == EAGAIN) {
             vconn_run(vconn);
@@ -899,7 +901,7 @@ pvconn_verify_name(const char *name)
  * stores a pointer to the new connection in '*pvconnp', otherwise a null
  * pointer.  */
 int
-pvconn_open(const char *name, struct pvconn **pvconnp)
+pvconn_open(const char *name, struct pvconn **pvconnp, uint8_t dscp)
 {
     struct pvconn_class *class;
     struct pvconn *pvconn;
@@ -916,7 +918,7 @@ pvconn_open(const char *name, struct pvconn **pvconnp)
 
     /* Call class's "open" function. */
     suffix_copy = xstrdup(strchr(name, ':') + 1);
-    error = class->listen(name, suffix_copy, &pvconn);
+    error = class->listen(name, suffix_copy, &pvconn, dscp);
     free(suffix_copy);
     if (error) {
         goto error;
diff --git a/lib/vconn.h b/lib/vconn.h
index 516e2d3a8..59713275e 100644
--- a/lib/vconn.h
+++ b/lib/vconn.h
@@ -33,7 +33,8 @@ void vconn_usage(bool active, bool passive, bool bootstrap);
 
 /* Active vconns: virtual connections to OpenFlow devices. */
 int vconn_verify_name(const char *name);
-int vconn_open(const char *name, int min_version, struct vconn **);
+int vconn_open(const char *name, int min_version,
+               struct vconn **, uint8_t dscp);
 void vconn_close(struct vconn *);
 const char *vconn_get_name(const struct vconn *);
 ovs_be32 vconn_get_remote_ip(const struct vconn *);
@@ -69,7 +70,7 @@ void vconn_send_wait(struct vconn *);
 
 /* Passive vconns: virtual listeners for incoming OpenFlow connections. */
 int pvconn_verify_name(const char *name);
-int pvconn_open(const char *name, struct pvconn **);
+int pvconn_open(const char *name, struct pvconn **, uint8_t dscp);
 const char *pvconn_get_name(const struct pvconn *);
 void pvconn_close(struct pvconn *);
 int pvconn_accept(struct pvconn *, int min_version, struct vconn **);