Allow setting a reconnection delay time after a failed authentication attempt (added min-reauth-time option).

NEWS

@@ -8,6 +8,8 @@
   enable non-openconnect clients to connect. They are enabled with
   the configure option --enable-anyconnect-compat.
 - Allow setting a rate limit on the number of connections.
+- Allow setting a reconnection delay time after a failed authentication
+  attempt (added min-reauth-time option).
 
 * Version 0.0.1 (released 2013-02-20)
 

doc/sample.config

@@ -85,6 +85,10 @@ tls-priorities = "PERFORMANCE:%SERVER_PRECEDENCE"
 # to authentication
 auth-timeout = 40
 
+# The time (in seconds) that a client is not allowed to reconnect after a failed
+# authentication attempt.
+min-reauth-time = 10
+
 # Cookie validity time (in seconds)
 # Once a client is authenticated he's provided a cookie with
 # which he can reconnect. This option sets the maximum lifetime

src/config.c

@@ -176,6 +176,7 @@ unsigned j;
 	READ_NUMERIC("cookie-validity", config->cookie_validity, 1);
 	READ_NUMERIC("auth-timeout", config->auth_timeout, 0);
 	READ_NUMERIC("max-clients", config->max_clients, 0);
+	READ_NUMERIC("min-reauth-time", config->min_reauth_time, 0);
 	READ_NUMERIC("max-same-clients", config->max_same_clients, 0);
 
 	val = optionGetValue(pov, "run-as-user"); \

src/main-auth.c

@@ -261,7 +261,7 @@ unsigned int entries = 1; /* that one */
 	if (s->config->max_same_clients == 0)
 		return 0; /* ok */
 
-	list_for_each(&s->clist->head, ctmp, list) {
+	list_for_each(&s->clist.head, ctmp, list) {
 
 		if (ctmp != proc) {
 			if (strcmp(proc->username, ctmp->username) == 0) {

src/main-misc.c

@@ -111,7 +111,6 @@ int send_udp_fd(main_server_st* s, struct proc_st * proc, int fd)
 int handle_commands(main_server_st *s, struct proc_st* proc)
 {
 	struct iovec iov[2];
-	char buf[128];
 	uint8_t cmd;
 	struct msghdr hdr;
 	struct lease_st *lease;
@@ -123,10 +122,8 @@ int handle_commands(main_server_st *s, struct proc_st* proc)
 		struct cmd_tun_mtu_st tmtu;
 	} cmd_data;
 	int ret, cmd_data_len, e;
-	const char* peer_ip, *group;
+	const char* group;
 
-	peer_ip = human_addr((void*)&proc->remote_addr, proc->remote_addr_len, buf, sizeof(buf));
-	
 	memset(&cmd_data, 0, sizeof(cmd_data));
 	
 	iov[0].iov_base = &cmd;
@@ -142,7 +139,7 @@ int handle_commands(main_server_st *s, struct proc_st* proc)
 	ret = recvmsg( proc->fd, &hdr, 0);
 	if (ret == -1) {
 		e = errno;
-		mslog(s, proc, LOG_ERR, "cannot obtain data from command socket (pid: %d, peer: %s): %s", proc->pid, peer_ip, strerror(e));
+		mslog(s, proc, LOG_ERR, "cannot obtain data from command socket: %s", strerror(e));
 		return -1;
 	}
 
@@ -241,6 +238,8 @@ int handle_commands(main_server_st *s, struct proc_st* proc)
 						mslog(s, proc, LOG_INFO, "user '%s' disconnected due to script", proc->username);
 					}
 				}
+			} else {
+				add_to_ip_ban_list(s, &proc->remote_addr, proc->remote_addr_len);
 			}
 
 			if (ret == 0) {
@@ -275,7 +274,7 @@ int handle_commands(main_server_st *s, struct proc_st* proc)
 				mslog(s, proc, LOG_INFO, "failed authentication attempt for user '%s'", proc->username);
 				ret = send_auth_reply( s, proc, REP_AUTH_FAILED, NULL);
 				if (ret < 0) {
-					mslog(s, proc, LOG_ERR, "could not send reply cmd (pid: %d, peer: %s).", proc->pid, peer_ip);
+					mslog(s, proc, LOG_ERR, "could not send reply cmd.");
 					ret = -2;
 					goto lease_cleanup;
 				}
@@ -301,3 +300,67 @@ lease_cleanup:
 	
 	return 0;
 }
+
+int check_if_banned(main_server_st* s, struct sockaddr_storage *addr, socklen_t addr_len)
+{
+time_t now = time(0);
+struct banned_st *btmp, *bpos;
+
+	if (s->config->min_reauth_time == 0)
+		return 0;
+
+	list_for_each_safe(&s->ban_list.head, btmp, bpos, list) {
+		if (now-btmp->failed_time > s->config->min_reauth_time) {
+			/* invalid entry. Clean it up */
+			list_del(&btmp->list);
+			free(btmp);
+		}
+					
+		if (SA_IN_SIZE(btmp->addr_len) == SA_IN_SIZE(addr_len) &&
+			memcmp(SA_IN_P_GENERIC(&btmp->addr, btmp->addr_len), 
+				SA_IN_P_GENERIC(addr, addr_len), 
+				SA_IN_SIZE(btmp->addr_len)) == 0) {
+			return -1;
+		}
+	}
+	
+	return 0;
+}
+
+
+void expire_banned(main_server_st* s)
+{
+time_t now = time(0);
+struct banned_st *btmp, *bpos;
+
+	if (s->config->min_reauth_time == 0)
+		return;
+
+	list_for_each_safe(&s->ban_list.head, btmp, bpos, list) {
+		if (now-btmp->failed_time > s->config->min_reauth_time) {
+			/* invalid entry. Clean it up */
+			list_del(&btmp->list);
+			free(btmp);
+		}
+	}
+
+	return;
+}
+
+void add_to_ip_ban_list(main_server_st* s, struct sockaddr_storage *addr, socklen_t addr_len)
+{
+struct banned_st *btmp;
+
+	if (s->config->min_reauth_time == 0)
+		return;
+
+	btmp = malloc(sizeof(*btmp));
+	if (btmp == NULL)
+		return;
+	
+	btmp->failed_time = time(0);
+	memcpy(&btmp->addr, addr, addr_len);
+	btmp->addr_len = addr_len;
+	
+	list_add(&s->ban_list.head, &(btmp->list));
+}

src/main.c

@@ -350,25 +350,32 @@ static void drop_privileges(main_server_st* s)
 	}
 }
 
-/* clears the server llist and clist. To be used after fork() */
+/* clears the server llist and clist. To be used after fork().
+ * It frees unused memory and descriptors.
+ */
 void clear_lists(main_server_st *s)
 {
 	struct listener_st *ltmp, *lpos;
 	struct proc_st *ctmp, *cpos;
+	struct banned_st *btmp, *bpos;
 
-	list_for_each_safe(&s->llist->head, ltmp, lpos, list) {
+	list_for_each_safe(&s->llist.head, ltmp, lpos, list) {
 		close(ltmp->fd);
 		list_del(&ltmp->list);
-		s->llist->total--;
+		s->llist.total--;
 	}
 
-	list_for_each_safe(&s->clist->head, ctmp, cpos, list) {
+	list_for_each_safe(&s->clist.head, ctmp, cpos, list) {
 		if (ctmp->fd >= 0)
 			close(ctmp->fd);
 		list_del(&ctmp->list);
-		s->clist->total--;
+		s->clist.total--;
 	}
-	
+
+	list_for_each_safe(&s->ban_list.head, btmp, bpos, list) {
+		list_del(&btmp->list);
+	}
+
 	tls_cache_deinit(s->tls_db);
 }
 
@@ -376,7 +383,7 @@ static void kill_children(main_server_st* s)
 {
 	struct proc_st *ctmp;
 
-	list_for_each(&s->clist->head, ctmp, list) {
+	list_for_each(&s->clist.head, ctmp, list) {
 		if (ctmp->pid != -1) {
 			kill(ctmp->pid, SIGTERM);
 			user_disconnected(s, ctmp);
@@ -455,7 +462,7 @@ int connected = 0;
 	session_id = &buffer[RECORD_PAYLOAD_POS+HANDSHAKE_SESSION_ID_POS+1];
 
 	/* search for the IP and the session ID in all procs */
-	list_for_each(&s->clist->head, ctmp, list) {
+	list_for_each(&s->clist.head, ctmp, list) {
 
 		if (session_id_size == ctmp->session_id_size &&
 			memcmp(session_id, ctmp->session_id, session_id_size) == 0) {
@@ -519,6 +526,7 @@ static void check_other_work(main_server_st *s)
 		mslog(s, NULL, LOG_INFO, "Performing maintainance");
 		expire_tls_sessions(s);
 		expire_cookies(s);
+		expire_banned(s);
 		alarm(MAINTAINANCE_TIME(s));
 	}
 		
@@ -548,8 +556,6 @@ static int check_tcp_wrapper(int fd)
 int main(int argc, char** argv)
 {
 	int fd, pid, e;
-	struct listen_list_st llist;
-	struct proc_list_st clist;
 	struct listener_st *ltmp;
 	struct proc_st *ctmp, *cpos;
 	struct tun_st tun;
@@ -564,7 +570,8 @@ int main(int argc, char** argv)
 
 	memset(&s, 0, sizeof(s));
 
-	list_head_init(&clist.head);
+	list_head_init(&s.clist.head);
+	list_head_init(&s.ban_list.head);
 	tun_st_init(&tun);
 	tls_cache_init(&s.tls_db);
 
@@ -594,8 +601,6 @@ int main(int argc, char** argv)
 
 	s.config = &config;
 	s.tun = &tun;
-	s.llist = &llist;
-	s.clist = &clist;
 
 	ret = cookie_db_init(&s);
 	if (ret < 0) {
@@ -604,7 +609,7 @@ int main(int argc, char** argv)
 	}
 	
 	/* Listen to network ports */
-	ret = listen_ports(&config, &llist, config.name);
+	ret = listen_ports(&config, &s.llist, config.name);
 	if (ret < 0) {
 		fprintf(stderr, "Cannot listen to specified ports\n");
 		exit(1);
@@ -645,7 +650,7 @@ int main(int argc, char** argv)
 		/* initialize select */
 		FD_ZERO(&rd);
 
-		list_for_each(&llist.head, ltmp, list) {
+		list_for_each(&s.llist.head, ltmp, list) {
 			if (ltmp->fd == -1) continue;
 
 			val = fcntl(ltmp->fd, F_GETFL, 0);
@@ -661,7 +666,7 @@ int main(int argc, char** argv)
 			n = MAX(n, ltmp->fd);
 		}
 
-		list_for_each(&clist.head, ctmp, list) {
+		list_for_each(&s.clist.head, ctmp, list) {
 			FD_SET(ctmp->fd, &rd);
 			n = MAX(n, ctmp->fd);
 		}
@@ -680,7 +685,7 @@ int main(int argc, char** argv)
 		}
 
 		/* Check for new connections to accept */
-		list_for_each(&llist.head, ltmp, list) {
+		list_for_each(&s.llist.head, ltmp, list) {
 			set = FD_ISSET(ltmp->fd, &rd);
 			if (set && ltmp->socktype == SOCK_STREAM) {
 				/* connection on TCP port */
@@ -693,6 +698,15 @@ int main(int argc, char** argv)
 				}
 				set_cloexec_flag (fd, 1);
 				
+				/* Check if the client is on the banned list */
+				ret = check_if_banned(&s, &ws.remote_addr, ws.remote_addr_len);
+				if (ret < 0) {
+					/* banned */
+					close(fd);
+					mslog(&s, NULL, LOG_INFO, "dropping client connection due to a previous failed authentication attempt");
+					break;
+				}
+
 				if (config.max_clients > 0 && active_clients >= config.max_clients) {
 					close(fd);
 					mslog(&s, NULL, LOG_INFO, "Reached maximum client limit (active: %u)", active_clients);
@@ -756,7 +770,7 @@ fork_failed:
 					ctmp->fd = cmd_fd[0];
 					set_cloexec_flag (cmd_fd[0], 1);
 
-					list_add(&clist.head, &(ctmp->list));
+					list_add(&s.clist.head, &(ctmp->list));
 					active_clients++;
 				}
 				close(cmd_fd[1]);
@@ -777,7 +791,7 @@ fork_failed:
 		}
 
 		/* Check for any pending commands */
-		list_for_each_safe(&clist.head, ctmp, cpos, list) {
+		list_for_each_safe(&s.clist.head, ctmp, cpos, list) {
 			if (FD_ISSET(ctmp->fd, &rd)) {
 				ret = handle_commands(&s, ctmp);
 				if (ret < 0) {

src/main.h

@@ -62,6 +62,17 @@ struct proc_list_st {
 	unsigned int total;
 };
 
+struct banned_st {
+	struct list_node list;
+	time_t failed_time;	/* The time authentication failed */
+	struct sockaddr_storage addr; /* local socket address */
+	socklen_t addr_len;
+};
+
+struct ban_list_st {
+	struct list_head head;
+};
+
 typedef struct main_server_st {
 	struct cfg_st *config;
 	struct tun_st *tun;
@@ -71,8 +82,9 @@ typedef struct main_server_st {
 	/* tls credentials */
 	struct tls_st creds;
 
-	struct listen_list_st* llist;
+	struct listen_list_st llist;
-	struct proc_list_st* clist;
+	struct proc_list_st clist;
+	struct ban_list_st ban_list;
 } main_server_st;
 
 void clear_lists(main_server_st *s);
@@ -117,4 +129,8 @@ int handle_auth_req(main_server_st *s, struct proc_st* proc,
 
 int check_multiple_users(main_server_st *s, struct proc_st* proc);
 
+void add_to_ip_ban_list(main_server_st* s, struct sockaddr_storage *addr, socklen_t addr_len);
+void expire_banned(main_server_st* s);
+int check_if_banned(main_server_st* s, struct sockaddr_storage *addr, socklen_t addr_len);
+
 #endif

src/ocserv-args.c

@@ -2,7 +2,7 @@
  *  
  *  DO NOT EDIT THIS FILE   (ocserv-args.c)
  *  
- *  It has been AutoGen-ed  March  4, 2013 at 06:18:05 AM by AutoGen 5.16
+ *  It has been AutoGen-ed  March  4, 2013 at 07:36:47 PM by AutoGen 5.16
  *  From the definitions    ocserv-args.def
  *  and the template file   options
  *

src/ocserv-args.def

@@ -150,6 +150,10 @@ tls-priorities = "PERFORMANCE:%SERVER_PRECEDENCE"
 # to authentication
 auth-timeout = 40
 
+# The time (in seconds) that a client is not allowed to reconnect after a failed
+# authentication attempt.
+min-reauth-time = 2
+
 # Cookie validity time (in seconds)
 # Once a client is authenticated he's provided a cookie with
 # which he can reconnect. This option sets the maximum lifetime

src/ocserv-args.h

@@ -2,7 +2,7 @@
  *  
  *  DO NOT EDIT THIS FILE   (ocserv-args.h)
  *  
- *  It has been AutoGen-ed  March  4, 2013 at 06:18:05 AM by AutoGen 5.16
+ *  It has been AutoGen-ed  March  4, 2013 at 07:36:47 PM by AutoGen 5.16
  *  From the definitions    ocserv-args.def
  *  and the template file   options
  *

src/vpn.h

@@ -72,6 +72,7 @@ struct cfg_st {
 	char *chroot_dir;	/* where the xml files are served from */
 	char *banner;
 	time_t cookie_validity;	/* in seconds */
+	time_t min_reauth_time;	/* after a failed auth, how soon one can reauthenticate -> in seconds */
 	unsigned auth_timeout; /* timeout of HTTP auth */
 	unsigned keepalive;
 	unsigned dpd;