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--- 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
|
