fix segmentation fault

k9982874 · k9982874 · commit 19c2ece76354 · 2019-05-18T13:48:49.000+08:00
diff --git a/ipset/ipset.c b/ipset/ipset.c
@@ -33,6 +33,23 @@ static int error_response(struct module_qstate* qstate, int id, int rcode) {
 	return 0;
 }
 
+static struct mnl_socket * open_mnl_socket() {
+	struct mnl_socket *mnl;
+
+	mnl = mnl_socket_open(NETLINK_NETFILTER);
+	if (!mnl) {
+		log_err("ipset: could not open netfilter.");
+		return NULL;
+	}
+
+	if (mnl_socket_bind(mnl, 0, MNL_SOCKET_AUTOPID) < 0) {
+		mnl_socket_close(mnl);
+		log_err("ipset: could not bind netfilter.");
+		return NULL;
+	}
+	return mnl;
+}
+
 static int add_to_ipset(struct mnl_socket *mnl, const char *setname, const void *ipaddr, int af) {
 	struct nlmsghdr *nlh;
 	struct nfgenmsg *nfg;
@@ -98,8 +115,14 @@ static int ipset_update(struct module_env *env, struct dns_msg *return_msg, stru
 	uint8_t *rr_data;
 
 	mnl = (struct mnl_socket *)ie->mnl;
-	if (mnl == NULL) {
-		return -1;
+	if (!mnl) {
+		// retry to create mnl socket
+		mnl = open_mnl_socket();
+		if (!mnl) {
+			return -1;
+		}
+
+		ie->mnl = mnl;
 	}
 
 	for (i = 0; i < return_msg->rep->rrset_count; ++i) {
@@ -119,7 +142,7 @@ static int ipset_update(struct module_env *env, struct dns_msg *return_msg, stru
 			}
 		}
 
-		if (setname != NULL) {
+		if (setname) {
 			dlen = sldns_wire2str_dname_buf(rrset->rk.dname, rrset->rk.dname_len, dname, BUFF_LEN);
 			if (dlen == 0) {
 				log_err("bad domain name");
@@ -146,6 +169,9 @@ static int ipset_update(struct module_env *env, struct dns_msg *return_msg, stru
 								ret = add_to_ipset(mnl, setname, rr_data + 2, af);
 								if (ret < 0) {
 									log_err("ipset: could not add %s into %s", dname, setname);
+
+									mnl_socket_close(mnl);
+									ie->mnl = NULL;
 									break;
 								}
 							}
@@ -154,58 +180,48 @@ static int ipset_update(struct module_env *env, struct dns_msg *return_msg, stru
 					}
 				}
 			}
-	        }
+		}
 	}
 
 	return 0;
 }
 
 int ipset_init(struct module_env* env, int id) {
-	struct mnl_socket *mnl;
+	struct ipset_env *ipset_env;
 
-	struct ipset_env *ipset_env = (struct ipset_env *)calloc(1,
-		sizeof(struct ipset_env));
-	if(!ipset_env) {
+	ipset_env = (struct ipset_env *)calloc(1, sizeof(struct ipset_env));
+	if (!ipset_env) {
 		log_err("malloc failure");
 		return 0;
 	}
-	env->modinfo[id] = (void*)ipset_env;
+
+	env->modinfo[id] = (void *)ipset_env;
+
+	ipset_env->mnl == NULL;
 
 	ipset_env->name_v4 = env->cfg->ipset_name_v4;
 	ipset_env->name_v6 = env->cfg->ipset_name_v6;
 
-	ipset_env->v4_enabled = (ipset_env->name_v4 == NULL) || (strlen(ipset_env->name_v4) == 0) ? 0 : 1;
-	ipset_env->v6_enabled = (ipset_env->name_v6 == NULL) || (strlen(ipset_env->name_v6) == 0) ? 0 : 1;
+	ipset_env->v4_enabled = !ipset_env->name_v4 || (strlen(ipset_env->name_v4) == 0) ? 0 : 1;
+	ipset_env->v6_enabled = !ipset_env->name_v6 || (strlen(ipset_env->name_v6) == 0) ? 0 : 1;
 
 	if ((ipset_env->v4_enabled < 1) && (ipset_env->v6_enabled < 1)) {
 		log_err("ipset: set name no configuration?");
 		return 0;
 	}
 
-	mnl = mnl_socket_open(NETLINK_NETFILTER);
-	if (mnl <= 0) {
-		log_err("ipset: could not open netfilter.");
-		return 0;
-	}
-
-	if (mnl_socket_bind(mnl, 0, MNL_SOCKET_AUTOPID) < 0) {
-		mnl_socket_close(mnl);
-		log_err("ipset: could not bind netfilter.");
-		return 0;
-	}
-
-	ipset_env->mnl = mnl;
-
 	return 1;
 }
 
 void ipset_deinit(struct module_env *env, int id) {
 	struct mnl_socket *mnl;
+	struct ipset_env *ipset_env;
 
-	struct ipset_env* ipset_env;
-	if(!env || !env->modinfo[id])
+	if (!env || !env->modinfo[id]) {
 		return;
-	ipset_env = (struct ipset_env*)env->modinfo[id];
+	}
+
+	ipset_env = (struct ipset_env *)env->modinfo[id];
 
 	mnl = (struct mnl_socket *)ipset_env->mnl;
 	if (mnl) {
@@ -218,11 +234,13 @@ void ipset_deinit(struct module_env *env, int id) {
 }
 
 static int ipset_new(struct module_qstate* qstate, int id) {
-	struct ipset_qstate* iq = (struct ipset_qstate*)regional_alloc(
+	struct ipset_qstate *iq = (struct ipset_qstate *)regional_alloc(
 		qstate->region, sizeof(struct ipset_qstate));
 	qstate->minfo[id] = iq;
-	if(!iq)
+	if (!iq) {
 		return 0;
+	}
+
 	memset(iq, 0, sizeof(*iq));
 	/* initialise it */
 	/* TODO */
@@ -236,42 +254,47 @@ void ipset_operate(struct module_qstate *qstate, enum module_ev event, int id,
 	struct ipset_qstate *iq = (struct ipset_qstate *)qstate->minfo[id];
 	verbose(VERB_QUERY, "ipset[module %d] operate: extstate:%s event:%s",
 		id, strextstate(qstate->ext_state[id]), strmodulevent(event));
-	if(iq) log_query_info(VERB_QUERY, "ipset operate: query",
-		&qstate->qinfo);
+	if (iq) {
+		log_query_info(VERB_QUERY, "ipset operate: query", &qstate->qinfo);
+	}
 
 	/* perform ipset state machine */
-	if((event == module_event_new || event == module_event_pass) &&
-		iq == NULL) {
-		if(!ipset_new(qstate, id)) {
+	if ((event == module_event_new || event == module_event_pass) && !iq) {
+		if (!ipset_new(qstate, id)) {
 			(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 			return;
 		}
 		iq = (struct ipset_qstate*)qstate->minfo[id];
 	}
 
-	if(iq && (event == module_event_pass || event == module_event_new)) {
+	if (iq && (event == module_event_pass || event == module_event_new)) {
 		qstate->ext_state[id] = module_wait_module;
 		return;
 	}
 
-	if(iq && (event == module_event_moddone)) {
-		ipset_update(qstate->env, qstate->return_msg, ie);
+	if (iq && (event == module_event_moddone)) {
+		if (qstate->return_msg && qstate->return_msg->rep) {
+			ipset_update(qstate->env, qstate->return_msg, ie);
+		}
 		qstate->ext_state[id] = module_finished;
 		return;
 	}
-	if(iq && outbound) {
+
+	if (iq && outbound) {
 		/* ipset does not need to process responses at this time
 		 * ignore it.
 		ipset_process_response(qstate, iq, ie, id, outbound, event);
 		*/
 		return;
 	}
-	if(event == module_event_error) {
+
+	if (event == module_event_error) {
 		verbose(VERB_ALGO, "got called with event error, giving up");
 		(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 		return;
 	}
-	if(!iq && (event == module_event_moddone)) {
+
+	if (!iq && (event == module_event_moddone)) {
 		/* during priming, module done but we never started */
 		qstate->ext_state[id] = module_finished;
 		return;
@@ -281,25 +304,26 @@ void ipset_operate(struct module_qstate *qstate, enum module_ev event, int id,
 	(void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
 }
 
-void ipset_inform_super(struct module_qstate* ATTR_UNUSED(qstate),
-	int ATTR_UNUSED(id), struct module_qstate* ATTR_UNUSED(super)) {
+void ipset_inform_super(struct module_qstate *ATTR_UNUSED(qstate),
+	int ATTR_UNUSED(id), struct module_qstate *ATTR_UNUSED(super)) {
 	/* ipset does not use subordinate requests at this time */
 	verbose(VERB_ALGO, "ipset inform_super was called");
 }
 
-void ipset_clear(struct module_qstate* qstate, int id) {
-	struct cachedb_qstate* iq;
-	if(!qstate)
+void ipset_clear(struct module_qstate *qstate, int id) {
+	struct cachedb_qstate *iq;
+	if (!qstate) {
 		return;
-	iq = (struct cachedb_qstate*)qstate->minfo[id];
-	if(iq) {
+	}
+	iq = (struct cachedb_qstate *)qstate->minfo[id];
+	if (iq) {
 		/* free contents of iq */
 		/* TODO */
 	}
 	qstate->minfo[id] = NULL;
 }
 
-size_t ipset_get_mem(struct module_env* env, int id) {
+size_t ipset_get_mem(struct module_env *env, int id) {
 	struct ipset_env *ie = (struct ipset_env *)env->modinfo[id];
 	if (!ie) {
 		return 0;
@@ -320,4 +344,3 @@ struct module_func_block * ipset_get_funcblock(void) {
 	return &ipset_block;
 }
 
-
