confd: Add support for dependency tracking between modules

Author: mattiaswal

src/confd/src/core.c

@@ -93,17 +93,139 @@ int core_post_hook(sr_session_ctx_t *session, uint32_t sub_id, const char *modul
 	return SR_ERR_OK;
 }
 
+static confd_dependency_t add_dependencies(struct lyd_node **diff, const char *xpath, const char *value)
+{
+	struct lyd_node *new_node = NULL;
+	struct lyd_node *target = NULL;
+	struct lyd_node *root = NULL;
+	int rc;
+
+	if (!lydx_get_xpathf(*diff, "%s", xpath)) {
+		/* Create the path, potentially creating a new tree */
+		rc = lyd_new_path(NULL, LYD_CTX(*diff), xpath, value, LYD_NEW_PATH_UPDATE, &new_node);
+		if (rc != LY_SUCCESS || !new_node) {
+			ERROR("lyd_new_path failed with rc=%d", rc);
+			return CONFD_DEP_ERROR;
+		}
+
+		root = new_node;
+		while (root->parent)
+			root = lyd_parent(root);
+
+		rc = lyd_merge_siblings(diff, root, LYD_MERGE_DESTRUCT);
+		if (rc != LY_SUCCESS) {
+			ERROR("lyd_merge_siblings failed with rc=%d", rc);
+			lyd_free_tree(root);
+			return CONFD_DEP_ERROR;
+		}
+
+		target = lydx_get_xpathf(*diff, "%s", xpath);
+		if (target) {
+			lyd_new_meta(LYD_CTX(target), target, NULL,
+				     "yang:operation", "replace", false, NULL);
+		} else {
+			return CONFD_DEP_ERROR;
+		}
+
+		return CONFD_DEP_ADDED;
+	}
+
+	return CONFD_DEP_DONE;
+}
+
+static confd_dependency_t handle_dependencies(struct lyd_node **diff, struct lyd_node *config)
+{
+	struct lyd_node *dkeys, *dkey, *hostname;
+	confd_dependency_t result = CONFD_DEP_DONE;
+	const char *key_name;
+
+	dkeys = lydx_get_descendant(*diff, "keystore", "symmetric-keys", "symmetric-key", NULL);
+
+	LYX_LIST_FOR_EACH(dkeys, dkey, "symmetric-key") {
+		struct ly_set *ifaces;
+		uint32_t i;
+
+		key_name = lydx_get_cattr(dkey, "name");
+		ifaces = lydx_find_xpathf(config, "/ietf-interfaces:interfaces/interface[infix-interfaces:wifi/secret='%s']", key_name);
+		if (ifaces && ifaces->count > 0) {
+			for (i = 0; i < ifaces->count; i++) {
+				struct lyd_node *iface = ifaces->dnodes[i];
+				const char *ifname;
+				char xpath[256];
+				ifname = lydx_get_cattr(iface, "name");
+				snprintf(xpath, sizeof(xpath), "/ietf-interfaces:interfaces/interface[name='%s']/infix-interfaces:wifi/secret", ifname);
+				result = add_dependencies(diff, xpath, key_name);
+				if (result == CONFD_DEP_ERROR) {
+					ERROR("Failed to add wifi node to diff for interface %s", ifname);
+					ly_set_free(ifaces, NULL);
+					return result;
+				}
+			}
+			ly_set_free(ifaces, NULL);
+		}
+	}
+
+	dkeys = lydx_get_descendant(*diff, "keystore", "asymmetric-keys", "asymmetric-key", NULL);
+	LYX_LIST_FOR_EACH(dkeys, dkey, "asymmetric-key") {
+		struct ly_set *hostkeys;
+		uint32_t i;
+
+		key_name = lydx_get_cattr(dkey, "name");
+		hostkeys = lydx_find_xpathf(config, "/infix-services:ssh/hostkey[.='%s']", key_name);
+		if (hostkeys && hostkeys->count > 0) {
+			for (i = 0; i < hostkeys->count; i++) {
+				char xpath[256];
+				snprintf(xpath, sizeof(xpath), "/infix-services:ssh/hostkey[.='%s']", key_name);
+				result = add_dependencies(diff, xpath, key_name);
+				if (result == CONFD_DEP_ERROR) {
+					ERROR("Failed to add ssh hostkey to diff for key %s", key_name);
+					ly_set_free(hostkeys, NULL);
+					return result;
+				}
+			}
+			ly_set_free(hostkeys, NULL);
+		}
+	}
+
+	hostname = lydx_get_xpathf(*diff, "/ietf-system:system/hostname");
+	if (hostname) {
+		struct lyd_node *mdns, *dhcp_server;
+
+		dhcp_server = lydx_get_xpathf(config, "/infix-dhcp-server:dhcp-server/enabled");
+		if(dhcp_server && lydx_is_enabled(dhcp_server, "enabled")) {
+			result = add_dependencies(diff, "/infix-dhcp-server:dhcp-server/enabled", "true");
+			if (result == CONFD_DEP_ERROR) {
+				ERROR("Failed to add dhcp-server to diff on hostname change");
+				return result;
+			}
+		}
+		mdns = lydx_get_xpathf(config, "/infix-services:mdns");
+		if (mdns && lydx_is_enabled(mdns, "enabled")) {
+			result = add_dependencies(diff, "/infix-services:mdns/enabled", "true");
+			if (result == CONFD_DEP_ERROR) {
+				ERROR("Failed to add mdns to diff on hostname change");
+				return result;
+			}
+		}
+	}
+
+	return result;
+}
+
 static int change_cb(sr_session_ctx_t *session, uint32_t sub_id, const char *module_name,
 		     const char *xpath, sr_event_t event, uint32_t request_id, void *_confd)
 {
+<<<<<<< HEAD
       struct confd *confd = _confd;
       char *output = NULL;
       struct lyd_node *diff = NULL, *config = NULL;
       sr_data_t *cfg = NULL;
-
+      confd_dependency_t result;
       int rc = SR_ERR_OK;
       static uint32_t last_id = 0;
       static uint32_t last_event = -1;
+	int max_dep = 10;
+
       if (request_id == last_id && last_event == event)
 	      return SR_ERR_OK;
       last_id = request_id;
@@ -121,28 +243,34 @@ static int change_cb(sr_session_ctx_t *session, uint32_t sub_id, const char *mod
 
 	      config = cfg->tree;
       }
-
-      // For logging: Write to file instead of using ERROR() to avoid truncation
-      if (diff) {
-          FILE *f = fopen("/tmp/sysrepo_diff.json", "w");
-          if (f) {
-              lyd_print_file(f, diff, LYD_JSON,
-                            LYD_PRINT_WITHSIBLINGS | LYD_PRINT_WD_ALL);
-              fclose(f);
-              ERROR("req_id=%u event=%d module=%s - Full diff written to /tmp/sysrepo_diff.json",
-                    request_id, event, module_name);
-          } else {
-              // Fallback: print to memory but limit what we log
-              lyd_print_mem(&output, diff, LYD_JSON, LYD_PRINT_WITHSIBLINGS);
-              if (output) {
-                  // Only log first 500 chars to avoid truncation
-                  ERROR("req_id=%u event=%d module=%s - Diff (truncated): %.500s...",
-                        request_id, event, module_name, output);
-                  free(output);
-              }
-          }
+      while ((result = handle_dependencies(&diff, config)) != CONFD_DEP_DONE) {
+	      if (result == CONFD_DEP_ERROR) {
+		      ERROR("Failed to add dependencies");
+		      break;
+	      }
       }
 
+		config = cfg->tree;
+		while ((result = handle_dependencies(&diff, config)) != CONFD_DEP_DONE) {
+			if (max_dep == 0) {
+				ERROR("Max dependency depth reached");
+				return SR_ERR_INTERNAL;
+			}
+			if (result == CONFD_DEP_ERROR) {
+				ERROR("Failed to add dependencies");
+				return SR_ERR_INTERNAL;
+			}
+			max_dep--;
+		}
+#if 0
+		/* Debug: print diff to file */
+		FILE *f = fopen("/tmp/confd-diff.json", "w");
+		if (f) {
+			lyd_print_file(f, diff, LYD_JSON, LYD_PRINT_WITHSIBLINGS);
+			fclose(f);
+		}
+#endif
+	}
       /* ietf-interfaces */
       ietf_interfaces_change(session, config, diff, event, confd);
 

src/confd/src/core.h

@@ -24,6 +24,7 @@
 
 #include <jansson.h>
 
+#include <srx/lyx.h>
 #include <srx/common.h>
 #include <srx/helpers.h>
 #include <srx/systemv.h>
@@ -100,6 +101,11 @@ static inline char *xpath_base(const char *xpath)
 
 	return path;
 }
+typedef enum {
+	CONFD_DEP_DONE = 0,
+	CONFD_DEP_ADDED = 1,
+	CONFD_DEP_ERROR = 2
+} confd_dependency_t;
 
 #define REGISTER_CHANGE(s,m,x,f,c,a,u)				\
 	if ((rc = register_change(s, m, x, f, c, a, u)))	\