Fix valgrind reported leak

src/mctpd.c

@@ -958,7 +958,14 @@ static int cb_listen_monitor(sd_event_source *s, int sd, uint32_t revents,
 		case MCTP_NL_DEL_LINK:
 		{
 			// Local addresses have already been deleted with DEL_EID
-			rc = del_interface(c->link_userdata);
+			if (c->link_userdata) {
+				rc = del_interface(c->link_userdata);
+			} else {
+				// Would have expected to have seen it in previous
+				// MCTP_NL_ADD_LINK or setup_nets().
+				rc = -ENOENT;
+				bug_warn("delete unconfigured interface %d", c->ifindex);
+			}
 			any_error |= (rc < 0);
 		}
 		break;
@@ -1378,12 +1385,10 @@ static int add_peer(struct ctx *ctx, const dest_phys *dest, mctp_eid_t eid,
 		return -ENOMEM;
 
 	// Allocate the peer itself
-	peer = malloc(sizeof(*peer));
+	peer = calloc(1, sizeof(*peer));
 	if (!peer)
 		return -ENOMEM;
 
-	memset(peer, 0, sizeof(*peer));
-
 	// Add it to our peers array
 	tmp = realloc(ctx->peers, (ctx->num_peers + 1) * sizeof(*ctx->peers));
 	if (!tmp)
@@ -1474,12 +1479,17 @@ static int remove_peer(struct peer *peer)
 	memmove(ctx->peers + idx, ctx->peers + idx + 1,
 		(ctx->num_peers - idx) * sizeof(struct peer *));
 
-	tmp = realloc(ctx->peers, ctx->num_peers * sizeof(struct peer *));
-	if (!tmp && ctx->num_peers) {
-		warn("%s: peer realloc(reduce!) failed", __func__);
-		// we'll re-try on next add/remove
+	if (ctx->num_peers > 0) {
+		tmp = realloc(ctx->peers, ctx->num_peers * sizeof(struct peer *));
+		if (!tmp) {
+			warn("%s: peer realloc(reduce!) failed", __func__);
+			// we'll re-try on next add/remove
+		} else {
+			ctx->peers = tmp;
+		}
 	} else {
-		ctx->peers = tmp;
+		free(ctx->peers);
+		ctx->peers = NULL;
 	}
 
 	free(peer);
@@ -1494,6 +1504,9 @@ static void free_peers(struct ctx *ctx)
 		free(peer->message_types);
 		free(peer->uuid);
 		free(peer->path);
+		sd_bus_slot_unref(peer->slot_obmc_endpoint);
+		sd_bus_slot_unref(peer->slot_cc_endpoint);
+		sd_bus_slot_unref(peer->slot_uuid);
 		free(peer);
 	}
 
@@ -3245,6 +3258,13 @@ static int prune_old_nets(struct ctx *ctx)
 	return 0;
 }
 
+static void free_link(struct link *link) {
+	sd_bus_slot_unref(link->slot_iface);
+	sd_bus_slot_unref(link->slot_busowner);
+	free(link->path);
+	free(link);
+}
+
 // Removes remote peers associated with an old interface.
 // Note that this link has already been removed from ctx->nl */
 static int del_interface(struct link *link)
@@ -3269,17 +3289,28 @@ static int del_interface(struct link *link)
 		warnx("Failed to remove D-Bus interface of ifindex %d",
 		      link->ifindex);
 	prune_old_nets(ctx);
+	free_link(link);
 
-	sd_bus_slot_unref(link->slot_iface);
-	link->slot_iface = NULL;
-	sd_bus_slot_unref(link->slot_busowner);
-	link->slot_busowner = NULL;
-
-	free(link->path);
-	free(link);
 	return 0;
 }
 
+// For program termination cleanup
+static void free_links(struct ctx *ctx)
+{
+	size_t num;
+	int* ifs;
+
+	ifs = mctp_nl_if_list(ctx->nl, &num);
+	for (size_t i = 0; i < num; i++) {
+		struct link* link = mctp_nl_get_link_userdata(ctx->nl, ifs[i]);
+		mctp_nl_set_link_userdata(ctx->nl, ifs[i], NULL);
+		if (link) {
+			free_link(link);
+		}
+	}
+	free(ifs);
+}
+
 // Moves remote peers from old->new net.
 static int change_net_interface(struct ctx *ctx, int ifindex, uint32_t old_net)
 {
@@ -3480,12 +3511,11 @@ static int add_net(struct ctx *ctx, uint32_t net_id)
 		return -EEXIST;
 	}
 
-	net = malloc(sizeof(*net));
+	net = calloc(1, sizeof(*net));
 	if (!net) {
 		warn("failed to allocate net");
 		return -ENOMEM;
 	}
-	memset(net, 0, sizeof(*net));
 
 	// Initialise the new entry
 	net->net = net_id;
@@ -3865,13 +3895,13 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	sd_bus_flush(ctx->bus);
-	sd_bus_close(ctx->bus);
-
-	mctp_nl_close(ctx->nl);
+	sd_bus_flush_close_unrefp(&ctx->bus);
 
+	free_links(ctx);
 	free_peers(ctx);
 	free_nets(ctx);
 
+	mctp_nl_close(ctx->nl);
+
 	return 0;
 }