freebsd-ports/security/openssh/files/patch-an

--- sshd.c.orig	Wed May  3 19:21:49 2000
+++ sshd.c	Fri May 12 07:11:43 2000
@@ -49,6 +49,13 @@
 int deny_severity = LOG_WARNING;
 #endif /* LIBWRAP */
 
+#ifdef __FreeBSD__
+#include <libutil.h>
+#include <poll.h>
+#include <syslog.h>
+#include <time.h>
+#endif /* __FreeBSD__ */
+
 #ifndef O_NOCTTY
 #define O_NOCTTY	0
 #endif
@@ -134,6 +141,32 @@
 unsigned char *session_id2 = NULL;
 int session_id2_len = 0;
 
+/* These are used to implement connections_per_period. */
+struct magic_connection {
+		struct timeval connections_begin;
+		unsigned int connections_this_period;
+} *magic_connections;
+/* Magic number, too!  TODO: this doesn't have to be static. */
+const size_t MAGIC_CONNECTIONS_SIZE = 1;
+
+static __inline int
+magic_hash(struct sockaddr_storage *sa) {
+
+	return 0;
+}
+
+static __inline struct timeval
+timevaldiff(struct timeval *tv1, struct timeval *tv2) {
+	struct timeval diff;
+	int carry;
+
+	carry = tv1->tv_usec > tv2->tv_usec;
+	diff.tv_sec = tv2->tv_sec - tv1->tv_sec - (carry ? 0 : 1);
+	diff.tv_usec = tv2->tv_usec - tv1->tv_usec + (carry ? 1000000 : 0);
+
+	return diff;
+}
+
 /* Prototypes for various functions defined later in this file. */
 void do_ssh1_kex();
 void do_ssh2_kex();
@@ -418,6 +451,7 @@
 	int opt, sock_in = 0, sock_out = 0, newsock, i, fdsetsz, on = 1;
 	pid_t pid;
 	socklen_t fromlen;
+ 	int connections_per_period_exceeded = 0;
 	int silent = 0;
 	fd_set *fdset;
 	struct sockaddr_storage from;
@@ -763,6 +797,12 @@
 		fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
 		fdset = (fd_set *)xmalloc(fdsetsz);
 
+		/* Initialize the magic_connections table.  It's magical! */
+		magic_connections = calloc(MAGIC_CONNECTIONS_SIZE,
+		    sizeof(struct magic_connection));
+		if (magic_connections == NULL)
+			fatal("calloc: %s", strerror(errno));
+
 		/*
 		 * Stay listening for connections until the system crashes or
 		 * the daemon is killed with a signal.
@@ -794,9 +834,31 @@
 				error("newsock del O_NONBLOCK: %s", strerror(errno));
 				continue;
 			}
+			if (options.connections_per_period != 0) {
+				struct timeval diff, connections_end;
+				struct magic_connection *mc;
+
+				(void)gettimeofday(&connections_end, NULL);
+				mc = &magic_connections[magic_hash(&from)];
+				diff = timevaldiff(&mc->connections_begin, &connections_end);
+				if (diff.tv_sec >= options.connections_period) {
+					/*
+					 * Slide the window forward only after completely
+					 * leaving it.
+					 */
+					mc->connections_begin = connections_end;
+					mc->connections_this_period = 1;
+				} else {
+					if (++mc->connections_this_period >
+					    options.connections_per_period)
+						connections_per_period_exceeded = 1;
+				}
+			}
+					
 			/*
-			 * Got connection.  Fork a child to handle it, unless
-			 * we are in debugging mode.
+			 * Got connection.  Fork a child to handle it unless
+			 * we are in debugging mode or the maximum number of
+			 * connections per period has been exceeded.
 			 */
 			if (debug_flag) {
 				/*
@@ -810,6 +872,12 @@
 				sock_out = newsock;
 				pid = getpid();
 				break;
+			} else if (connections_per_period_exceeded) {
+				log("Connection rate limit of %u/%us has been exceeded; "
+				    "dropping connection from %s.",
+				    options.connections_per_period, options.connections_period,
+				    ntop);
+				connections_per_period_exceeded = 0;
 			} else {
 				/*
 				 * Normal production daemon.  Fork, and have