setting pointers to NULL after free

doc/docs/index.md

@@ -2,28 +2,28 @@
 
 ## What is BlueChi?
 
-BlueChi (formerly known as hirte) is a deterministic multi-node service manager
+BlueChi (formerly known as hirte) is a deterministic multi-node service controller.
 
 BlueChi can manage the states of different services across multiple nodes with a
-focus on highly regulated industries, such as those requiring function safety.
+focus on highly regulated industries, such as those requiring functional safety.
 BlueChi integrates with systemd via its D-Bus API and relays D-Bus messages over
 TCP for multi-nodes support.
 
-On the main node a service called `bluechi-controller` is running. On startup, the manager
+On the main node a service called `bluechi-controller` is running. On startup, the controller
 loads the configuration files which describe all the involved systems
 (called nodes) that are expected to be managed. Each node has a
-unique name that is used to reference it in the manager.
+unique name that is used to reference it in the controller.
 
 On each managed node that is under control of BlueChi a service called `bluechi-agent`
-is running. When the service starts, it connects (via D-Bus over TCP) to the manager
+is running. When the service starts, it connects (via D-Bus over TCP) to the controller
 and registers as available (optionally authenticating). It then receives requests
-from the manager and reports local state changes to it.
+from the controller and reports local state changes to it.
 
 ## Background
 
 BlueChi is built around three components:
 
-* `bluechi-controller` service, running on the primary node, is the primary orchestrator
+* `bluechi-controller` service, running on the primary node, controls all connected nodes
 * `bluechi-agent` services, with one running on each managed node, is the agent
   talking locally to systemd to act on services
 * `bluechictl` command line program, is meant to be used by administrators to test,

src/agent/agent.c

@@ -71,8 +71,8 @@ static void agent_job_op_unref(AgentJobOp *op) {
         }
 
         agent_unref(op->agent);
-        free(op->unit);
-        free(op->method);
+        free_and_null(op->unit);
+        free_and_null(op->method);
         free(op);
 }
 
@@ -290,9 +290,9 @@ static char *make_unit_path(const char *unit) {
 
 static void unit_info_clear(void *item) {
         AgentUnitInfo *info = item;
-        free(info->object_path);
-        free(info->unit);
-        free(info->substate);
+        free_and_null(info->object_path);
+        free_and_null(info->unit);
+        free_and_null(info->substate);
 }
 
 static uint64_t unit_info_hash(const void *item, uint64_t seed0, uint64_t seed1) {
@@ -475,11 +475,11 @@ void agent_unref(Agent *agent) {
 
         hashmap_free(agent->unit_infos);
 
-        free(agent->name);
-        free(agent->host);
-        free(agent->orch_addr);
-        free(agent->api_bus_service_name);
-        free(agent->manager_address);
+        free_and_null(agent->name);
+        free_and_null(agent->host);
+        free_and_null(agent->orch_addr);
+        free_and_null(agent->api_bus_service_name);
+        free_and_null(agent->manager_address);
 
         if (agent->event != NULL) {
                 sd_event_unrefp(&agent->event);
@@ -1766,7 +1766,7 @@ static void job_tracker_free(JobTracker *track) {
         if (track->userdata && track->free_userdata) {
                 track->free_userdata(track->userdata);
         }
-        free(track->job_object_path);
+        free_and_null(track->job_object_path);
         free(track);
 }
 
@@ -1953,7 +1953,7 @@ static int agent_match_unit_new(sd_bus_message *m, void *userdata, UNUSED sd_bus
          */
         info->active_state = UNIT_INACTIVE;
         if (info->substate != NULL) {
-                free(info->substate);
+                free_and_null(info->substate);
         }
         info->substate = strdup("dead");
 
@@ -1984,8 +1984,7 @@ static int agent_match_unit_removed(sd_bus_message *m, void *userdata, UNUSED sd
 
         info->loaded = false;
         info->active_state = _UNIT_ACTIVE_STATE_INVALID;
-        free(info->substate);
-        info->substate = NULL;
+        free_and_null(info->substate);
 
         if (info->subscribed || agent->wildcard_subscription_active) {
                 /* Forward the event */
@@ -2088,7 +2087,7 @@ int agent_init_units(Agent *agent, sd_bus_message *m) {
                         info->loaded = true;
                         info->active_state = active_state_from_string(active_state);
                         if (info->substate != NULL) {
-                                free(info->substate);
+                                free_and_null(info->substate);
                         }
                         info->substate = strdup(sub_state);
                 }
@@ -2486,8 +2485,7 @@ static bool agent_reconnect(Agent *agent) {
         // resolve FQDN again in case the system changed
         // e.g. bluechi controller has been migrated to a different host
         if (agent->orch_addr != NULL) {
-                free(agent->orch_addr);
-                agent->orch_addr = NULL;
+                free_and_null(agent->orch_addr);
         }
         if (!ensure_orch_address(agent)) {
                 return false;

src/agent/proxy.c

@@ -263,10 +263,10 @@ void proxy_service_unref(ProxyService *proxy) {
         sd_bus_message_unrefp(&proxy->request_message);
         sd_bus_slot_unrefp(&proxy->export_slot);
 
-        free(proxy->node_name);
-        free(proxy->unit_name);
-        free(proxy->local_service_name);
-        free(proxy->object_path);
+        free_and_null(proxy->node_name);
+        free_and_null(proxy->unit_name);
+        free_and_null(proxy->local_service_name);
+        free_and_null(proxy->object_path);
         free(proxy);
 }
 

src/client/client.c

@@ -42,7 +42,7 @@ void client_unref(Client *client) {
                 sd_bus_unrefp(&client->api_bus);
         }
         if (client->object_path != NULL) {
-                free(client->object_path);
+                free_and_null(client->object_path);
         }
 
         free(client);

src/client/method_monitor.c

@@ -372,11 +372,10 @@ static void node_unref(Node *node) {
         }
 
         if (node->connection != NULL) {
-                free(node->connection->name);
-                free(node->connection->node_path);
-                free(node->connection->state);
-                free(node->connection);
-                node->connection = NULL;
+                free_and_null(node->connection->name);
+                free_and_null(node->connection->node_path);
+                free_and_null(node->connection->state);
+                free_and_null(node->connection);
         }
 
         if (node->nodes != NULL) {

src/libbluechi/bus/utils.c

@@ -133,16 +133,16 @@ void unit_unref(UnitInfo *unit) {
                 return;
         }
 
-        free(unit->node);
-        free(unit->id);
-        free(unit->description);
-        free(unit->load_state);
-        free(unit->active_state);
-        free(unit->sub_state);
-        free(unit->following);
-        free(unit->unit_path);
-        free(unit->job_type);
-        free(unit->job_path);
+        free_and_null(unit->node);
+        free_and_null(unit->id);
+        free_and_null(unit->description);
+        free_and_null(unit->load_state);
+        free_and_null(unit->active_state);
+        free_and_null(unit->sub_state);
+        free_and_null(unit->following);
+        free_and_null(unit->unit_path);
+        free_and_null(unit->job_type);
+        free_and_null(unit->job_path);
 
         free(unit);
 }

src/libbluechi/common/cfg.c

@@ -33,9 +33,9 @@ static int option_compare(const void *a, const void *b, UNUSED void *udata) {
 
 static void option_destroy(void *item) {
         struct config_option *option = item;
-        free(option->section);
-        free(option->name);
-        free(option->value);
+        free_and_null(option->section);
+        free_and_null(option->name);
+        free_and_null(option->value);
 }
 
 static uint64_t option_hash(const void *item, uint64_t seed0, uint64_t seed1) {
@@ -114,8 +114,8 @@ int cfg_copy_overwrite(struct config *src, struct config *dst) {
 
 void cfg_dispose(struct config *config) {
         hashmap_free(config->cfg_store);
-        free(config->default_section);
-        free(config);
+        free_and_null(config->default_section);
+        free_and_null(config);
 }
 
 int cfg_load_complete_configuration(
@@ -291,7 +291,7 @@ int cfg_set_default_section(struct config *config, const char *section_name) {
         if (section_copy == NULL) {
                 return -ENOMEM;
         }
-        free(config->default_section);
+        free_and_null(config->default_section);
         config->default_section = section_copy;
 
         return 0;
@@ -338,9 +338,9 @@ int cfg_s_set_value(
         }
 
         if (replaced != NULL) {
-                free(replaced->section);
-                free(replaced->name);
-                free(replaced->value);
+                free_and_null(replaced->section);
+                free_and_null(replaced->name);
+                free_and_null(replaced->value);
         }
         return 0;
 }

src/libbluechi/common/common.h

@@ -37,6 +37,12 @@ static inline void freep(void *p) {
         free(*(void **) p);
 }
 
+// NOLINTBEGIN(bugprone-macro-parentheses)
+#define free_and_null(ptr) \
+        free(ptr);         \
+        ptr = NULL;
+// NOLINTEND(bugprone-macro-parentheses)
+
 typedef void (*free_func_t)(void *ptr);
 
 #define malloc0(n) (calloc(1, (n) ?: 1))

src/manager/job.c

@@ -84,9 +84,9 @@ void job_unref(Job *job) {
 
         sd_bus_slot_unrefp(&job->export_slot);
 
-        free(job->object_path);
-        free(job->unit);
-        free(job->type);
+        free_and_null(job->object_path);
+        free_and_null(job->unit);
+        free_and_null(job->type);
         free(job);
 }
 

src/manager/manager.c

@@ -96,7 +96,7 @@ void manager_unref(Manager *manager) {
 
         sd_event_unrefp(&manager->event);
 
-        free(manager->api_bus_service_name);
+        free_and_null(manager->api_bus_service_name);
 
         sd_event_source_unrefp(&manager->node_connection_source);
 

src/manager/monitor.c

@@ -85,12 +85,12 @@ void subscription_unref(Subscription *subscription) {
         SubscribedUnit *next_su = NULL;
         LIST_FOREACH_SAFE(units, su, next_su, subscription->subscribed_units) {
                 LIST_REMOVE(units, subscription->subscribed_units, su);
-                free(su->name);
-                free(su);
+                free_and_null(su->name);
+                free_and_null(su);
         }
 
-        free(subscription->node);
-        free(subscription);
+        free_and_null(subscription->node);
+        free_and_null(subscription);
 }
 
 
@@ -163,9 +163,9 @@ void monitor_unref(Monitor *monitor) {
         }
 
         sd_bus_slot_unrefp(&monitor->export_slot);
-        free(monitor->object_path);
-        free(monitor->client);
-        free(monitor);
+        free_and_null(monitor->object_path);
+        free_and_null(monitor->client);
+        free_and_null(monitor);
 }
 
 bool monitor_export(Monitor *monitor) {

src/manager/node.c

@@ -85,8 +85,8 @@ struct ProxyDependency {
 };
 
 static void proxy_dependency_free(struct ProxyDependency *dep) {
-        free(dep->unit_name);
-        free(dep);
+        free_and_null(dep->unit_name);
+        free_and_null(dep);
 }
 
 typedef struct UnitSubscription UnitSubscription;
@@ -110,8 +110,8 @@ typedef struct {
 
 static void unit_subscriptions_clear(void *item) {
         UnitSubscriptions *usubs = item;
-        free(usubs->unit);
-        free(usubs->substate);
+        free_and_null(usubs->unit);
+        free_and_null(usubs->substate);
         assert(LIST_IS_EMPTY(usubs->subs));
 }
 
@@ -201,8 +201,8 @@ void node_unref(Node *node) {
         node_unset_agent_bus(node);
         hashmap_free(node->unit_subscriptions);
 
-        free(node->name);
-        free(node->object_path);
+        free_and_null(node->name);
+        free_and_null(node->object_path);
         free(node);
 }
 
@@ -1669,7 +1669,7 @@ void node_unsubscribe(Node *node, Subscription *sub) {
                 }
 
                 LIST_REMOVE(subs, usubs->subs, found);
-                free(found);
+                free_and_null(found);
 
                 if (LIST_IS_EMPTY(usubs->subs)) {
                         /* Last subscription for this unit, tell agent */

src/manager/proxy_monitor.c

@@ -78,8 +78,8 @@ void proxy_monitor_unref(ProxyMonitor *monitor) {
                 subscription_unref(monitor->subscription);
         }
 
-        free(monitor->unit_name);
-        free(monitor->proxy_object_path);
+        free_and_null(monitor->unit_name);
+        free_and_null(monitor->proxy_object_path);
         free(monitor);
 }