[ovs-dev,v2,2/4] conntrack: add commands to r/w CT parameters.

diff --git a/lib/conntrack.c b/lib/conntrack.c
index 419cb1d..391d008 100644
--- a/lib/conntrack.c
+++ b/lib/conntrack.c
@@ -67,6 +67,13 @@  enum ct_alg_mode {
     CT_TFTP_MODE,
 };
 
+/* Variable to manage read/write on CT parameters. */
+struct ct_cfg_params {
+    char *cli;      /* Parameter name in human format. */
+    int (*wr)(struct conntrack *, uint32_t);
+    int (*rd)(struct conntrack *, uint32_t *);
+};
+
 static bool conn_key_extract(struct conntrack *, struct dp_packet *,
                              ovs_be16 dl_type, struct conn_lookup_ctx *,
                              uint16_t zone);
@@ -2391,6 +2398,59 @@  conntrack_flush(struct conntrack *ct, const uint16_t *zone)
     return 0;
 }
 
+/* List of parameters that can be read/written at run-time. */
+struct ct_cfg_params cfg_params[] = {};
+
+int
+conntrack_set_param(struct conntrack *ct,
+        const char *set_param)
+{
+    uint32_t max_conn;
+    char buf[16] = "";
+
+    /* Check if the specified param can be managed. */
+    for (int i = 0; i < sizeof(cfg_params) / sizeof(struct ct_cfg_params);
+             i++) {
+        if (!strncmp(set_param, cfg_params[i].cli,
+                strlen(cfg_params[i].cli))) {
+            ovs_strzcpy(buf, cfg_params[i].cli, sizeof(buf) - 1);
+            strncat(buf, "=%"SCNu32, sizeof(buf) - 1 - strlen(buf));
+            if (ovs_scan(set_param, buf, &max_conn)) {
+                return (cfg_params[i].wr
+                        ? cfg_params[i].wr(ct, max_conn)
+                        : EOPNOTSUPP);
+            } else {
+                return EINVAL;
+            }
+        }
+    }
+    /* The entered param didn't match any in the list. */
+    VLOG_WARN("%s parameter is not managed by this command.", set_param);
+
+    return EINVAL;
+}
+
+int
+conntrack_get_param(struct conntrack *ct,
+        const char *get_param, uint32_t *val)
+{
+    /* Check if the specified param can be managed. */
+    for (int i = 0; i < sizeof(cfg_params) / sizeof(struct ct_cfg_params);
+             i++) {
+        if (!strncmp(get_param, cfg_params[i].cli,
+                strlen(cfg_params[i].cli))) {
+
+            return (cfg_params[i].rd
+                    ? cfg_params[i].rd(ct, val)
+                    : EOPNOTSUPP);
+        }
+    }
+    /* The entered param didn't match any in the list. */
+    VLOG_WARN("%s parameter is not managed by this command.", get_param);
+
+    return EINVAL;
+}
+
 /* This function must be called with the ct->resources read lock taken. */
 static struct alg_exp_node *
 expectation_lookup(struct hmap *alg_expectations,
diff --git a/lib/conntrack.h b/lib/conntrack.h
index fbeef1c..4eb9a9a 100644
--- a/lib/conntrack.h
+++ b/lib/conntrack.h
@@ -114,6 +114,9 @@  int conntrack_dump_next(struct conntrack_dump *, struct ct_dpif_entry *);
 int conntrack_dump_done(struct conntrack_dump *);
 
 int conntrack_flush(struct conntrack *, const uint16_t *zone);
+int conntrack_set_param(struct conntrack *, const char *set_param);
+int conntrack_get_param(struct conntrack *, const char *get_param,
+                        uint32_t *val);
 
 /* 'struct ct_lock' is a wrapper for an adaptive mutex.  It's useful to try
  * different types of locks (e.g. spinlocks) */
diff --git a/lib/ct-dpif.c b/lib/ct-dpif.c
index c79e69e..599bc57 100644
--- a/lib/ct-dpif.c
+++ b/lib/ct-dpif.c
@@ -127,6 +127,34 @@  ct_dpif_flush(struct dpif *dpif, const uint16_t *zone)
             : EOPNOTSUPP);
 }
 
+int
+ct_dpif_set_param(struct dpif *dpif, const char *set_param)
+{
+    if (!set_param) {
+        VLOG_DBG("%s: ct_set_param: no input param", dpif_name(dpif));
+        return EINVAL;
+    }
+    VLOG_DBG("%s: ct_set_param: %s", dpif_name(dpif), set_param);
+
+    return (dpif->dpif_class->ct_set_param
+            ? dpif->dpif_class->ct_set_param(dpif, set_param)
+            : EOPNOTSUPP);
+}
+
+int
+ct_dpif_get_param(struct dpif *dpif, const char *get_param, uint32_t *val)
+{
+    if (!get_param) {
+        VLOG_DBG("%s: ct_get_param: no input param", dpif_name(dpif));
+        return EINVAL;
+    }
+    VLOG_DBG("%s: ct_get_param: %s", dpif_name(dpif), get_param);
+
+    return (dpif->dpif_class->ct_get_param
+            ? dpif->dpif_class->ct_get_param(dpif, get_param, val)
+            : EOPNOTSUPP);
+}
+
 void
 ct_dpif_entry_uninit(struct ct_dpif_entry *entry)
 {
diff --git a/lib/ct-dpif.h b/lib/ct-dpif.h
index d5f9661..92ce3e9 100644
--- a/lib/ct-dpif.h
+++ b/lib/ct-dpif.h
@@ -196,6 +196,8 @@  int ct_dpif_dump_start(struct dpif *, struct ct_dpif_dump_state **,
 int ct_dpif_dump_next(struct ct_dpif_dump_state *, struct ct_dpif_entry *);
 int ct_dpif_dump_done(struct ct_dpif_dump_state *);
 int ct_dpif_flush(struct dpif *, const uint16_t *zone);
+int ct_dpif_set_param(struct dpif *dpif, const char *set_param);
+int ct_dpif_get_param(struct dpif *dpif, const char *get_param, uint32_t *val);
 void ct_dpif_entry_uninit(struct ct_dpif_entry *);
 void ct_dpif_format_entry(const struct ct_dpif_entry *, struct ds *,
                           bool verbose, bool print_stats);
diff --git a/lib/dpctl.c b/lib/dpctl.c
index b6eecf0..5b02951 100644
--- a/lib/dpctl.c
+++ b/lib/dpctl.c
@@ -1589,6 +1589,80 @@  dpctl_ct_bkts(int argc, const char *argv[],
     free(conn_per_bkts);
     return error;
 }
+
+static int
+dpctl_ct_set_param(int argc, const char *argv[],
+        struct dpctl_params *dpctl_p)
+{
+    struct dpif *dpif;
+    char *name;
+    int error;
+
+    /* The datapath name is not a mandatory parameter for this command.
+     * If it is not specified - so argc < 3 - we retrieve it from the
+     * current setup, assuming only one exists. */
+    name = argc == 3 ? xstrdup(argv[1]) : get_one_dp(dpctl_p);
+    if (!name) {
+        return EINVAL;
+    }
+    error = parsed_dpif_open(name, false, &dpif);
+    free(name);
+    if (error) {
+        dpctl_error(dpctl_p, error, "opening datapath");
+        return error;
+    }
+
+    error = ct_dpif_set_param(dpif, argv[argc - 1]);
+
+    if (!error) {
+        dpctl_print(dpctl_p, "Ok");
+    } else {
+        dpctl_print(dpctl_p, "CT set global cfg failed (%s)",
+                        ovs_strerror(error));
+    }
+
+    dpif_close(dpif);
+
+    return error;
+}
+
+static int
+dpctl_ct_get_param(int argc, const char *argv[],
+        struct dpctl_params *dpctl_p)
+{
+    struct dpif *dpif;
+    uint32_t param_val;
+    char *name;
+    int error;
+
+    /* The datapath name is not a mandatory parameter for this command.
+     * If it is not specified - so argc < 3 - we retrieve it from the
+     * current setup, assuming only one exists. */
+    name = argc == 3 ? xstrdup(argv[1]) : get_one_dp(dpctl_p);
+    if (!name) {
+        return EINVAL;
+    }
+    error = parsed_dpif_open(name, false, &dpif);
+    free(name);
+    if (error) {
+        dpctl_error(dpctl_p, error, "opening datapath");
+        return error;
+    }
+
+    error = ct_dpif_get_param(dpif, argv[argc - 1], &param_val);
+
+    if (!error) {
+        dpctl_print(dpctl_p, "Current value: %d", param_val);
+    } else {
+        dpctl_print(dpctl_p, "CT get global cfg failed (%s)",
+                        ovs_strerror(error));
+    }
+
+    dpif_close(dpif);
+
+    return error;
+}
+
 
 /* Undocumented commands for unit testing. */
 
@@ -1885,6 +1959,8 @@  static const struct dpctl_command all_commands[] = {
     { "ct-stats-show", "[dp] [zone=N] [verbose]",
       0, 3, dpctl_ct_stats_show, DP_RO },
     { "ct-bkts", "[dp] [gt=N]", 0, 2, dpctl_ct_bkts, DP_RO },
+    { "ct-set-glbl-cfg", "[dp] param=..", 1, 2, dpctl_ct_set_param, DP_RW },
+    { "ct-get-glbl-cfg", "[dp] param", 1, 2, dpctl_ct_get_param, DP_RO },
     { "help", "", 0, INT_MAX, dpctl_help, DP_RO },
     { "list-commands", "", 0, INT_MAX, dpctl_list_commands, DP_RO },
 
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index ca74df8..8fda2a9 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -5689,6 +5689,23 @@  dpif_netdev_ct_flush(struct dpif *dpif, const uint16_t *zone)
     return conntrack_flush(&dp->conntrack, zone);
 }
 
+static int
+dpif_netdev_ct_set_param(struct dpif *dpif, const char *set_param)
+{
+    struct dp_netdev *dp = get_dp_netdev(dpif);
+
+    return conntrack_set_param(&dp->conntrack, set_param);
+}
+
+static int
+dpif_netdev_ct_get_param(struct dpif *dpif, const char *get_param,
+                         uint32_t *val)
+{
+    struct dp_netdev *dp = get_dp_netdev(dpif);
+
+    return conntrack_get_param(&dp->conntrack, get_param, val);
+}
+
 const struct dpif_class dpif_netdev_class = {
     "netdev",
     dpif_netdev_init,
@@ -5734,6 +5751,8 @@  const struct dpif_class dpif_netdev_class = {
     dpif_netdev_ct_dump_next,
     dpif_netdev_ct_dump_done,
     dpif_netdev_ct_flush,
+    dpif_netdev_ct_set_param,
+    dpif_netdev_ct_get_param,
     dpif_netdev_meter_get_features,
     dpif_netdev_meter_set,
     dpif_netdev_meter_get,
diff --git a/lib/dpif-netlink.c b/lib/dpif-netlink.c
index 29001fb..0945fad 100644
--- a/lib/dpif-netlink.c
+++ b/lib/dpif-netlink.c
@@ -2986,6 +2986,8 @@  const struct dpif_class dpif_netlink_class = {
     dpif_netlink_ct_dump_next,
     dpif_netlink_ct_dump_done,
     dpif_netlink_ct_flush,
+    NULL,                       /* ct_set_param */
+    NULL,                       /* ct_get_param */
     dpif_netlink_meter_get_features,
     dpif_netlink_meter_set,
     dpif_netlink_meter_get,
diff --git a/lib/dpif-provider.h b/lib/dpif-provider.h
index 1d82a09..262b2e0 100644
--- a/lib/dpif-provider.h
+++ b/lib/dpif-provider.h
@@ -427,6 +427,10 @@  struct dpif_class {
     /* Flushes the connection tracking tables. If 'zone' is not NULL,
      * only deletes connections in '*zone'. */
     int (*ct_flush)(struct dpif *, const uint16_t *zone);
+    /* Set a value to a connection tracking working parameter. */
+    int (*ct_set_param)(struct dpif *, const char *set_param);
+    /* Read the current value of a connection tracking working parameter. */
+    int (*ct_get_param)(struct dpif *, const char *get_param, uint32_t *val);
 
     /* Meters */