ovs-vsctl: Check for dirty reads within transactions.

OVSDB is transactional but it does not implement any form of locking.  This
means that read-modify-write operations must verify that the values that
they read are still in place before writing.  This commit adds such
checking.

Bug #2387.
Bug #3856.
Bug #3906.

1 files changed, 63 insertions, 0 deletions

diff --git a/utilities/ovs-vsctl.c b/utilities/ovs-vsctl.c
index f370d6ba4..916ac659a 100644
--- a/utilities/ovs-vsctl.c
+++ b/utilities/ovs-vsctl.c
@@ -507,6 +507,7 @@ struct vsctl_context {
     struct ovsdb_idl_txn *txn;
     struct ovsdb_symbol_table *symtab;
     const struct ovsrec_open_vswitch *ovs;
+    bool verified_ports;
 
     /* A command may set this member to true if some prerequisite is not met
      * and the caller should wait for something to change and then retry. */
@@ -564,6 +565,25 @@ vsctl_context_to_string(const struct vsctl_context *ctx)
     return s;
 }
 
+static void
+verify_ports(struct vsctl_context *ctx)
+{
+    if (!ctx->verified_ports) {
+        const struct ovsrec_bridge *bridge;
+        const struct ovsrec_port *port;
+
+        ovsrec_open_vswitch_verify_bridges(ctx->ovs);
+        OVSREC_BRIDGE_FOR_EACH (bridge, ctx->idl) {
+            ovsrec_bridge_verify_ports(bridge);
+        }
+        OVSREC_PORT_FOR_EACH (port, ctx->idl) {
+            ovsrec_port_verify_interfaces(port);
+        }
+
+        ctx->verified_ports = true;
+    }
+}
+
 static struct vsctl_bridge *
 add_bridge(struct vsctl_info *b,
            struct ovsrec_bridge *br_cfg, const char *name,
@@ -740,6 +760,8 @@ check_conflicts(struct vsctl_info *info, const char *name,
     struct vsctl_iface *iface;
     struct vsctl_port *port;
 
+    verify_ports(info->ctx);
+
     if (shash_find(&info->bridges, name)) {
         vsctl_fatal("%s because a bridge named %s already exists",
                     msg, name);
@@ -767,6 +789,7 @@ find_bridge(struct vsctl_info *info, const char *name, bool must_exist)
     if (must_exist && !br) {
         vsctl_fatal("no bridge named %s", name);
     }
+    ovsrec_open_vswitch_verify_bridges(info->ctx->ovs);
     return br;
 }
 
@@ -790,6 +813,7 @@ find_port(struct vsctl_info *info, const char *name, bool must_exist)
     if (must_exist && !port) {
         vsctl_fatal("no port named %s", name);
     }
+    verify_ports(info->ctx);
     return port;
 }
 
@@ -803,6 +827,7 @@ find_iface(struct vsctl_info *info, const char *name, bool must_exist)
     if (must_exist && !iface) {
         vsctl_fatal("no interface named %s", name);
     }
+    verify_ports(info->ctx);
     return iface;
 }
 
@@ -1202,6 +1227,7 @@ cmd_br_set_external_id(struct vsctl_context *ctx)
                         bridge->br_cfg->n_external_ids,
                         ctx->argv[2], ctx->argc >= 4 ? ctx->argv[3] : NULL,
                         &keys, &values, &n);
+        ovsrec_bridge_verify_external_ids(bridge->br_cfg);
         ovsrec_bridge_set_external_ids(bridge->br_cfg, keys, values, n);
     } else {
         char *key = xasprintf("fake-bridge-%s", ctx->argv[2]);
@@ -1211,6 +1237,7 @@ cmd_br_set_external_id(struct vsctl_context *ctx)
                         port->port_cfg->n_external_ids,
                         key, ctx->argc >= 4 ? ctx->argv[3] : NULL,
                         &keys, &values, &n);
+        ovsrec_port_verify_external_ids(port->port_cfg);
         ovsrec_port_set_external_ids(port->port_cfg, keys, values, n);
         free(key);
     }
@@ -1252,6 +1279,7 @@ cmd_br_get_external_id(struct vsctl_context *ctx)
     get_info(ctx, &info);
     bridge = find_bridge(&info, ctx->argv[1], true);
     if (bridge->br_cfg) {
+        ovsrec_bridge_verify_external_ids(bridge->br_cfg);
         get_external_id(bridge->br_cfg->key_external_ids,
                         bridge->br_cfg->value_external_ids,
                         bridge->br_cfg->n_external_ids,
@@ -1259,6 +1287,7 @@ cmd_br_get_external_id(struct vsctl_context *ctx)
                         &ctx->output);
     } else {
         struct vsctl_port *port = shash_find_data(&info.ports, ctx->argv[1]);
+        ovsrec_port_verify_external_ids(port->port_cfg);
         get_external_id(port->port_cfg->key_external_ids,
                         port->port_cfg->value_external_ids,
                         port->port_cfg->n_external_ids,
@@ -1278,6 +1307,7 @@ cmd_list_ports(struct vsctl_context *ctx)
 
     get_info(ctx, &info);
     br = find_bridge(&info, ctx->argv[1], true);
+    ovsrec_bridge_verify_ports(br->br_cfg ? br->br_cfg : br->parent->br_cfg);
 
     svec_init(&ports);
     SHASH_FOR_EACH (node, &info.ports) {
@@ -1518,6 +1548,7 @@ cmd_list_ifaces(struct vsctl_context *ctx)
 
     get_info(ctx, &info);
     br = find_bridge(&info, ctx->argv[1], true);
+    verify_ports(ctx);
 
     svec_init(&ifaces);
     SHASH_FOR_EACH (node, &info.ifaces) {
@@ -1547,6 +1578,19 @@ cmd_iface_to_br(struct vsctl_context *ctx)
 }
 
 static void
+verify_controllers(struct ovsrec_bridge *bridge)
+{
+    if (bridge) {
+        size_t i;
+
+        ovsrec_bridge_verify_controller(bridge);
+        for (i = 0; i < bridge->n_controller; i++) {
+            ovsrec_controller_verify_target(bridge->controller[i]);
+        }
+    }
+}
+
+static void
 cmd_get_controller(struct vsctl_context *ctx)
 {
     struct vsctl_info info;
@@ -1556,6 +1600,7 @@ cmd_get_controller(struct vsctl_context *ctx)
 
     get_info(ctx, &info);
     br = find_bridge(&info, ctx->argv[1], true);
+    verify_controllers(br->br_cfg);
 
     /* Print the targets in sorted order for reproducibility. */
     svec_init(&targets);
@@ -1591,6 +1636,7 @@ cmd_del_controller(struct vsctl_context *ctx)
 
     get_info(ctx, &info);
     br = find_real_bridge(&info, ctx->argv[1], true);
+    verify_controllers(br->br_cfg);
 
     if (br->ctrl) {
         delete_controllers(br->ctrl, br->n_ctrl);
@@ -1625,6 +1671,7 @@ cmd_set_controller(struct vsctl_context *ctx)
 
     get_info(ctx, &info);
     br = find_real_bridge(&info, ctx->argv[1], true);
+    verify_controllers(br->br_cfg);
 
     delete_controllers(br->ctrl, br->n_ctrl);
 
@@ -1645,6 +1692,9 @@ cmd_get_fail_mode(struct vsctl_context *ctx)
     get_info(ctx, &info);
     br = find_bridge(&info, ctx->argv[1], true);
 
+    if (br->br_cfg) {
+        ovsrec_bridge_verify_fail_mode(br->br_cfg);
+    }
     if (br->fail_mode && strlen(br->fail_mode)) {
         ds_put_format(&ctx->output, "%s\n", br->fail_mode);
     }
@@ -1690,7 +1740,13 @@ cmd_get_ssl(struct vsctl_context *ctx)
 {
     struct ovsrec_ssl *ssl = ctx->ovs->ssl;
 
+    ovsrec_open_vswitch_verify_ssl(ctx->ovs);
     if (ssl) {
+        ovsrec_ssl_verify_private_key(ssl);
+        ovsrec_ssl_verify_certificate(ssl);
+        ovsrec_ssl_verify_ca_cert(ssl);
+        ovsrec_ssl_verify_bootstrap_ca_cert(ssl);
+
         ds_put_format(&ctx->output, "Private key: %s\n", ssl->private_key);
         ds_put_format(&ctx->output, "Certificate: %s\n", ssl->certificate);
         ds_put_format(&ctx->output, "CA Certificate: %s\n", ssl->ca_cert);
@@ -1705,6 +1761,7 @@ cmd_del_ssl(struct vsctl_context *ctx)
     struct ovsrec_ssl *ssl = ctx->ovs->ssl;
 
     if (ssl) {
+        ovsrec_open_vswitch_verify_ssl(ctx->ovs);
         ovsrec_ssl_delete(ssl);
         ovsrec_open_vswitch_set_ssl(ctx->ovs, NULL);
     }
@@ -1716,6 +1773,7 @@ cmd_set_ssl(struct vsctl_context *ctx)
     bool bootstrap = shash_find(&ctx->options, "--bootstrap");
     struct ovsrec_ssl *ssl = ctx->ovs->ssl;
 
+    ovsrec_open_vswitch_verify_ssl(ctx->ovs);
     if (ssl) {
         ovsrec_ssl_delete(ssl);
     }
@@ -1900,6 +1958,7 @@ get_row_by_id(struct vsctl_context *ctx, const struct vsctl_table_class *table,
     if (id->uuid_column) {
         const struct ovsdb_datum *uuid;
 
+        ovsdb_idl_txn_verify(referrer, id->uuid_column);
         uuid = ovsdb_idl_get(referrer, id->uuid_column,
                              OVSDB_TYPE_UUID, OVSDB_TYPE_VOID);
         if (uuid->n == 1) {
@@ -2173,6 +2232,7 @@ cmd_get(struct vsctl_context *ctx)
                                             &column, &key_string,
                                             NULL, NULL, 0, NULL));
 
+        ovsdb_idl_txn_verify(row, column);
         datum = ovsdb_idl_read(row, column);
         if (key_string) {
             union ovsdb_atom key;
@@ -2365,6 +2425,7 @@ cmd_add(struct vsctl_context *ctx)
                     type->value.type == OVSDB_TYPE_VOID ? "values" : "pairs",
                     column->name, table->class->name, type->n_max);
     }
+    ovsdb_idl_txn_verify(row, column);
     ovsdb_idl_txn_write(row, column, &old);
 }
 
@@ -2413,6 +2474,7 @@ cmd_remove(struct vsctl_context *ctx)
                     type->value.type == OVSDB_TYPE_VOID ? "values" : "pairs",
                     column->name, table->class->name, type->n_min);
     }
+    ovsdb_idl_txn_verify(row, column);
     ovsdb_idl_txn_write(row, column, &old);
 }
 
@@ -2653,6 +2715,7 @@ vsctl_context_init(struct vsctl_context *ctx, struct vsctl_command *command,
     ctx->txn = txn;
     ctx->ovs = ovs;
     ctx->symtab = symtab;
+    ctx->verified_ports = false;
 
     ctx->try_again = false;
 }