Merge krb4 1.0.4.

8 files changed, 355 insertions, 126 deletions

diff --git a/kerberosIV/src/appl/bsd/rshd.c b/kerberosIV/src/appl/bsd/rshd.c
index 973c20a0e29..7493a6de665 100644
--- a/kerberosIV/src/appl/bsd/rshd.c
+++ b/kerberosIV/src/appl/bsd/rshd.c
@@ -42,7 +42,7 @@
 
 #include "bsd_locl.h"
 
-RCSID("$KTH: rshd.c,v 1.60.2.1 2000/06/23 02:40:54 assar Exp $");
+RCSID("$KTH: rshd.c,v 1.60.2.3 2000/10/18 20:39:12 assar Exp $");
 
 extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */
 extern int __check_rhosts_file;
@@ -435,6 +435,11 @@ doit(struct sockaddr_in *fromp)
 	    close(2);
 	    close(pv[1]);
 
+	    if (s >= FD_SETSIZE || pv[0] >= FD_SETSIZE) {
+		error ("fd too large\n");
+		exit (1);
+	    }
+
 	    FD_ZERO(&readfrom);
 	    FD_SET(s, &readfrom);
 	    FD_SET(pv[0], &readfrom);
@@ -443,6 +448,11 @@ doit(struct sockaddr_in *fromp)
 	    else
 		nfd = s;
 	    if (doencrypt) {
+		if (pv2[1] >= FD_SETSIZE || pv1[0] >= FD_SETSIZE) {
+		    error ("fd too large\n");
+		    exit (1);
+		}
+
 		FD_ZERO(&writeto);
 		FD_SET(pv2[1], &writeto);
 		FD_SET(pv1[0], &readfrom);
diff --git a/kerberosIV/src/appl/bsd/su.c b/kerberosIV/src/appl/bsd/su.c
index e93a2b43ba3..f1d28d58831 100644
--- a/kerberosIV/src/appl/bsd/su.c
+++ b/kerberosIV/src/appl/bsd/su.c
@@ -33,20 +33,20 @@
 
 #include "bsd_locl.h"
 
-RCSID ("$KTH: su.c,v 1.70.2.1 2000/06/23 02:42:28 assar Exp $");
+RCSID ("$KTH: su.c,v 1.70.2.2 2000/12/07 14:04:19 assar Exp $");
 
 #ifdef SYSV_SHADOW
 #include "sysv_shadow.h"
 #endif
 
-static int kerberos (char *username, char *user, int uid);
+static int kerberos (char *username, char *user, char *realm, int uid);
 static int chshell (char *sh);
 static char *ontty (void);
 static int koktologin (char *name, char *realm, char *toname);
 static int chshell (char *sh);
 
 /* Handle '-' option after all the getopt options */
-#define	ARGSTR	"Kflmti:"
+#define	ARGSTR	"Kkflmti:r:"
 
 int destroy_tickets = 0;
 static int use_kerberos = 1;
@@ -63,15 +63,22 @@ main (int argc, char **argv)
     enum { UNSET, YES, NO } iscsh = UNSET;
     char *user, *shell, *avshell, *username, **np;
     char shellbuf[MaxPathLen], avshellbuf[MaxPathLen];
+    char *realm = NULL;
 
     set_progname (argv[0]);
 
+    if (getuid() == 0)
+    	use_kerberos = 0;
+
     asme = asthem = fastlogin = 0;
     while ((ch = getopt (argc, argv, ARGSTR)) != -1)
 	switch ((char) ch) {
 	case 'K':
 	    use_kerberos = 0;
 	    break;
+	case 'k':
+	    use_kerberos = 1;
+	    break;
 	case 'f':
 	    fastlogin = 1;
 	    break;
@@ -89,10 +96,13 @@ main (int argc, char **argv)
 	case 'i':
 	    root_inst = optarg;
 	    break;
+	case 'r':
+	    realm = optarg;
+	    break;
 	case '?':
 	default:
 	    fprintf (stderr,
-		     "usage: su [-Kflmt] [-i root-instance] [-] [login]\n");
+		     "usage: su [-Kkflmt] [-i root-instance] [-r realm] [-] [login]\n");
 	    exit (1);
 	}
     /* Don't handle '-' option with getopt */
@@ -150,7 +160,7 @@ main (int argc, char **argv)
 	syslog (LOG_ALERT, "NIS attack, user %s has uid 0", user);
 	errx (1, "unknown login %s", user);
     }
-    if (!use_kerberos || kerberos (username, user, pwd->pw_uid)) {
+    if (!use_kerberos || kerberos (username, user, realm, pwd->pw_uid)) {
 #ifndef PASSWD_FALLBACK
 	errx (1, "won't use /etc/passwd authentication");
 #endif
@@ -226,7 +236,7 @@ main (int argc, char **argv)
     if (setgid (pwd->pw_gid) < 0)
 	err (1, "setgid");
     if (initgroups (user, pwd->pw_gid)) {
-        if (errno == E2BIG)    /* Member of to many groups! */
+        if (errno == E2BIG)    /* Member of too many groups! */
 	    warn("initgroups failed.");
 	else
 	    errx(1, "initgroups failed.");
@@ -337,19 +347,26 @@ ontty (void)
 }
 
 static int
-kerberos (char *username, char *user, int uid)
+kerberos (char *username, char *user, char *lrealm, int uid)
 {
     KTEXT_ST ticket;
     AUTH_DAT authdata;
     struct hostent *hp;
     int kerno;
     u_long faddr;
-    char lrealm[REALM_SZ], krbtkfile[MaxPathLen];
+    char tmp_realm[REALM_SZ], krbtkfile[MaxPathLen];
     char hostname[MaxHostNameLen], savehost[MaxHostNameLen];
+    int n;
+    int allowed = 0;
 
-    if (krb_get_lrealm (lrealm, 1) != KSUCCESS)
-	return (1);
-    if (koktologin (username, lrealm, user) && !uid) {
+    if (lrealm != NULL) {
+	allowed = koktologin (username, lrealm, user) == 0;
+    } else {
+	for (n = 1; !allowed && krb_get_lrealm (tmp_realm, n) == KSUCCESS; ++n)
+	    allowed = koktologin (username, tmp_realm, user) == 0;
+	lrealm = tmp_realm;
+    }
+    if (!allowed && !uid) {
 #ifndef PASSWD_FALLBACK
 	warnx ("not in %s's ACL.", user);
 #endif
@@ -433,7 +450,11 @@ kerberos (char *username, char *user, int uid)
     }
     strlcpy (savehost, krb_get_phost (hostname), sizeof (savehost));
 
-    kerno = krb_mk_req (&ticket, "rcmd", savehost, lrealm, 33);
+    for (n = 1; krb_get_lrealm (tmp_realm, n) == KSUCCESS; ++n) {
+	kerno = krb_mk_req (&ticket, "rcmd", savehost, tmp_realm, 33);
+	if (kerno == 0)
+	    break;
+    }
 
     if (kerno == KDC_PR_UNKNOWN) {
 	warnx ("Warning: TGT not verified.");
diff --git a/kerberosIV/src/appl/ftp/ftpd/ftpd.c b/kerberosIV/src/appl/ftp/ftpd/ftpd.c
index 44bbd5f94c3..6f0ad14dfc9 100644
--- a/kerberosIV/src/appl/ftp/ftpd/ftpd.c
+++ b/kerberosIV/src/appl/ftp/ftpd/ftpd.c
@@ -38,7 +38,7 @@
 #endif
 #include "getarg.h"
 
-RCSID("$KTH: ftpd.c,v 1.131.2.3 2000/06/23 02:49:48 assar Exp $");
+RCSID("$KTH: ftpd.c,v 1.131.2.4 2000/09/26 09:30:26 assar Exp $");
 
 static char version[] = "Version 6.00";
 
diff --git a/kerberosIV/src/appl/telnet/telnetd/telnetd.c b/kerberosIV/src/appl/telnet/telnetd/telnetd.c
index 3e627bc2d4c..73825df7db3 100644
--- a/kerberosIV/src/appl/telnet/telnetd/telnetd.c
+++ b/kerberosIV/src/appl/telnet/telnetd/telnetd.c
@@ -33,7 +33,7 @@
 
 #include "telnetd.h"
 
-RCSID("$KTH: telnetd.c,v 1.58 1999/11/13 06:31:04 assar Exp $");
+RCSID("$KTH: telnetd.c,v 1.58.2.1 2000/10/10 13:12:08 assar Exp $");
 
 #ifdef _SC_CRAY_SECURE_SYS
 #include <sys/sysv.h>
@@ -1008,6 +1008,11 @@ my_telnet(int f, int p, char *host, int level, char *autoname)
 	FD_ZERO(&ibits);
 	FD_ZERO(&obits);
 	FD_ZERO(&xbits);
+
+	if (f >= FD_SETSIZE
+	    || p >= FD_SETSIZE)
+	    fatal(net, "fd too large");
+
 	/*
 	 * Never look for input if there's still
 	 * stuff in the corresponding output buffer
diff --git a/kerberosIV/src/kadmin/admin_server.c b/kerberosIV/src/kadmin/admin_server.c
index d7bb477c265..bf0626c914c 100644
--- a/kerberosIV/src/kadmin/admin_server.c
+++ b/kerberosIV/src/kadmin/admin_server.c
@@ -30,7 +30,7 @@ or implied warranty.
 
 #include "kadm_locl.h"
 
-RCSID("$KTH: admin_server.c,v 1.49 1999/11/13 06:32:19 assar Exp $");
+RCSID("$KTH: admin_server.c,v 1.49.2.2 2000/10/18 20:24:57 assar Exp $");
 
 /* Almost all procs and such need this, so it is global */
 admin_params prm;		/* The command line parameters struct */
@@ -39,8 +39,16 @@ admin_params prm;		/* The command line parameters struct */
 char *acldir = DEFAULT_ACL_DIR;
 static char krbrlm[REALM_SZ];
 
-static unsigned pidarraysize = 0;
-static int *pidarray = NULL;
+#define MAXCHILDREN 100
+
+struct child {
+    pid_t pid;
+    int pipe_fd;
+    int authenticated;
+};
+
+static unsigned nchildren = 0;
+static struct child children[MAXCHILDREN];
 
 static int exit_now = 0;
 
@@ -52,46 +60,26 @@ doexit(int sig)
     SIGRETURN(0);
 }
    
+static sig_atomic_t do_wait;
+
 static
 RETSIGTYPE
 do_child(int sig)
 {
-    int pid;
-    int i, j;
-
-    int status;
-
-    pid = wait(&status);
-
-    /* Reinstall signal handlers for SysV. Must be done *after* wait */
-    signal(SIGCHLD, do_child);
-
-    for (i = 0; i < pidarraysize; i++)
-	if (pidarray[i] == pid) {
-	    /* found it */
-	    for (j = i; j < pidarraysize-1; j++)
-		/* copy others down */
-		pidarray[j] = pidarray[j+1];
-	    pidarraysize--;
-	    if ((WIFEXITED(status) && WEXITSTATUS(status) != 0)
-		|| WIFSIGNALED(status))
-	      krb_log("child %d: termsig %d, retcode %d", pid,
-		  WTERMSIG(status), WEXITSTATUS(status));
-	    SIGRETURN(0);
-	}
-    krb_log("child %d not in list: termsig %d, retcode %d", pid,
-	WTERMSIG(status), WEXITSTATUS(status));
+    do_wait = 1;
     SIGRETURN(0);
 }
 
+
 static void
 kill_children(void)
 {
     int i;
 
-    for (i = 0; i < pidarraysize; i++) {
-	kill(pidarray[i], SIGINT);
-	krb_log("killing child %d", pidarray[i]);
+    for (i = 0; i < nchildren; i++) {
+	kill(children[i].pid, SIGINT);
+	close (children[i].pipe_fd);
+	krb_log("killing child %d", children[i].pid);
     }
 }
 
@@ -117,11 +105,6 @@ clear_secrets(void)
     server_parm.master_key_version = 0L;
 }
 
-#ifdef DEBUG
-#define cleanexit(code) {kerb_fini(); return;}
-#endif
-
-#ifndef DEBUG
 static void
 cleanexit(int val)
 {
@@ -129,10 +112,21 @@ cleanexit(int val)
     clear_secrets();
     exit(val);
 }
-#endif
+
+static RETSIGTYPE
+sigalrm(int sig)
+{
+    cleanexit(1);
+}
+
+/*
+ * handle the client on the socket `fd' from `who'
+ * `signal_fd' is a pipe on which to signal when the user has been
+ * authenticated
+ */
 
 static void
-process_client(int fd, struct sockaddr_in *who)
+process_client(int fd, struct sockaddr_in *who, int signal_fd)
 {
     u_char *dat;
     int dat_len;
@@ -142,6 +136,13 @@ process_client(int fd, struct sockaddr_in *who)
     des_cblock skey;
     int more;
     int status;
+    int authenticated = 0;
+
+    /* make this connection time-out after 1 second if the user has
+       not managed one transaction succesfully in kadm_ser_in */
+
+    signal(SIGALRM, sigalrm);
+    alarm(2);
 
 #if defined(SO_KEEPALIVE) && defined(HAVE_SETSOCKOPT)
     {
@@ -230,8 +231,19 @@ process_client(int fd, struct sockaddr_in *who)
     	if (exit_now) {
 	    cleanexit(0);
 	}
-	if ((retval = kadm_ser_in(&dat, &dat_len, errpkt)) != KADM_SUCCESS)
+	retval = kadm_ser_in(&dat, &dat_len, errpkt);
+
+	if (retval == KADM_SUCCESS) {
+	    if (!authenticated) {
+		unsigned char one = 1;
+
+		authenticated = 1;
+		alarm (0);
+		write (signal_fd, &one, 1);
+	    }
+	} else {
 	    krb_log("processing request: %s", error_message(retval));
+	}
     
 	/* kadm_ser_in did the processing and returned stuff in
 	   dat & dat_len , return the appropriate data */
@@ -255,6 +267,175 @@ process_client(int fd, struct sockaddr_in *who)
     /*NOTREACHED*/
 }
 
+static void
+accept_client (int admin_fd)
+{
+    int pipe_fd[2];
+    int addrlen;
+    struct sockaddr_in peer;
+    pid_t pid;
+    int peer_fd;
+
+    /* using up the maximum number of children, try to get rid
+       of one unauthenticated one */
+
+    if (nchildren >= MAXCHILDREN) {
+	int i, nunauth = 0;
+	int victim;
+
+	for (;;) {
+	    for (i = 0; i < nchildren; ++i)
+		if (children[i].authenticated == 0)
+		    ++nunauth;
+	    if (nunauth == 0)
+		return;
+
+	    victim = rand() % nchildren;
+	    if (children[victim].authenticated == 0) {
+		kill(children[victim].pid, SIGINT);
+		close(children[victim].pipe_fd);
+		for (i = victim; i < nchildren; ++i)
+		    children[i] = children[i + 1];
+		--nchildren;
+		break;
+	    }
+	}
+    }
+
+    /* accept the conn */
+    addrlen = sizeof(peer);
+    peer_fd = accept(admin_fd, (struct sockaddr *)&peer, &addrlen);
+    if (peer_fd < 0) {
+	krb_log("accept: %s",error_message(errno));
+	return;
+    }
+    if (pipe (pipe_fd) < 0) {
+	krb_log ("pipe: %s", error_message(errno));
+	return;
+    }
+
+    if (pipe_fd[0] >= FD_SETSIZE
+	|| pipe_fd[1] >= FD_SETSIZE) {
+	krb_log ("pipe fds too large");
+	close (pipe_fd[0]);
+	close (pipe_fd[1]);
+	return;
+    }
+
+    pid = fork ();
+
+    if (pid < 0) {
+	krb_log ("fork: %s", error_message(errno));
+	close (pipe_fd[0]);
+	close (pipe_fd[1]);
+	return;
+    }
+
+    if (pid != 0) {
+	/* parent */
+	/* fork succeded: keep tabs on child */
+	close(peer_fd);
+	children[nchildren].pid     = pid;
+	children[nchildren].pipe_fd = pipe_fd[0];
+	children[nchildren].authenticated = 0;
+	++nchildren;
+	close (pipe_fd[1]);
+
+    } else {
+	int i;
+
+	/* child */
+	close(admin_fd);
+	close(pipe_fd[0]);
+
+	for (i = 0; i < nchildren; ++i)
+	    close (children[i].pipe_fd);
+
+	/*
+	 * If we are multihomed we need to figure out which
+	 * local address that is used this time since it is
+	 * used in "direction" comparison.
+	 */
+	getsockname(peer_fd,
+		    (struct sockaddr *)&server_parm.admin_addr,
+		    &addrlen);
+	/* do stuff */
+	process_client (peer_fd, &peer, pipe_fd[1]);
+    }
+}
+
+/*
+ * handle data signaled from child `child' kadmind
+ */
+
+static void
+handle_child_signal (int child)
+{
+    int ret;
+    unsigned char data[1];
+
+    ret = read (children[child].pipe_fd, data, 1);
+    if (ret < 0) {
+	if (errno != EINTR)
+	    krb_log ("read from child %d: %s", child,
+		     error_message(errno));
+	return;
+    }
+    if (ret == 0) {
+	close (children[child].pipe_fd);
+	children[child].pipe_fd = -1;
+	return;
+    }
+    if (data)
+	children[child].authenticated = 1;
+}
+
+/*
+ * handle dead children
+ */
+
+static void
+handle_sigchld (void)
+{
+    pid_t pid;
+    int status;
+    int i, j;
+
+    for (;;) {
+	int found = 0;
+
+	pid = waitpid(-1, &status, WNOHANG|WUNTRACED);
+	if (pid == 0 || (pid < 0 && errno == ECHILD))
+	    break;
+	if (pid < 0) {
+	    krb_log("waitpid: %s", error_message(errno));
+	    break;
+	}
+	for (i = 0; i < nchildren; i++)
+	    if (children[i].pid == pid) {
+		/* found it */
+		close(children[i].pipe_fd);
+		for (j = i; j < nchildren; j++)
+		    /* copy others down */
+		    children[j] = children[j+1];
+		--nchildren;
+#if 0
+		if ((WIFEXITED(status) && WEXITSTATUS(status) != 0)
+		    || WIFSIGNALED(status))
+		    krb_log("child %d: termsig %d, retcode %d", pid,
+			    WTERMSIG(status), WEXITSTATUS(status));
+#endif
+		found = 1;
+	    }
+#if 0
+	if (!found)
+	    krb_log("child %d not in list: termsig %d, retcode %d", pid,
+		    WTERMSIG(status), WEXITSTATUS(status));
+#endif
+    }
+    do_wait = 0;
+}
+
 /*
 kadm_listen
 listen on the admin servers port for a request
@@ -262,12 +443,9 @@ listen on the admin servers port for a request
 static int
 kadm_listen(void)
 {
+    int found;
     int admin_fd;
-    int peer_fd;
-    struct pollfd pfd[1];
-    struct sockaddr_in peer;
-    int addrlen;
-    int pid;
+    fd_set readfds;
 
     signal(SIGINT, doexit);
     signal(SIGTERM, doexit);
@@ -281,9 +459,15 @@ kadm_listen(void)
 
     if ((admin_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
 	return KADM_NO_SOCK;
+
+    if (admin_fd >= FD_SETSIZE) {
+	krb_log("admin_fd too big");
+	return KADM_NO_BIND;
+    }
+	
 #if defined(SO_REUSEADDR) && defined(HAVE_SETSOCKOPT)
     {
-      int one=1;
+      int one = 1;
       setsockopt(admin_fd, SOL_SOCKET, SO_REUSEADDR, (void *)&one,
 		 sizeof(one));
     }
@@ -291,73 +475,43 @@ kadm_listen(void)
     if (bind(admin_fd, (struct sockaddr *)&server_parm.admin_addr,
 	     sizeof(struct sockaddr_in)) < 0)
 	return KADM_NO_BIND;
-    listen(admin_fd, 1);
-
-    pfd[0].fd = admin_fd;
-    pfd[0].events = POLLIN;
+    if (listen(admin_fd, SOMAXCONN) < 0)
+	return KADM_NO_BIND;
 
     for (;;) {				/* loop nearly forever */
+	int i;
+	int maxfd = -1;
+
 	if (exit_now) {
 	    clear_secrets();
 	    kill_children();
 	    return(0);
 	}
-	if (poll(pfd, 1, -1) < 0) {
+	if (do_wait)
+	    handle_sigchld ();
+
+	FD_ZERO(&readfds);
+	FD_SET(admin_fd, &readfds);
+	maxfd = max(maxfd, admin_fd);
+	for (i = 0; i < nchildren; ++i)
+	    if (children[i].pipe_fd >= 0) {
+		FD_SET(children[i].pipe_fd, &readfds);
+		maxfd = max(maxfd, children[i].pipe_fd);
+	    }
+
+	found = select(maxfd + 1, &readfds, NULL, NULL, NULL);
+	if (found < 0) {
 	    if (errno != EINTR)
-		krb_log("poll: %s",error_message(errno));
+		krb_log("select: %s",error_message(errno));
 	    continue;
 	}
-	if (pfd[0].revents & POLLIN) {
-	    /* accept the conn */
-	    addrlen = sizeof(peer);
-	    if ((peer_fd = accept(admin_fd, (struct sockaddr *)&peer,
-				  &addrlen)) < 0) {
-		krb_log("accept: %s",error_message(errno));
-		continue;
+	if (FD_ISSET(admin_fd, &readfds)) 
+	    accept_client (admin_fd);
+	for (i = 0; i < nchildren; ++i)
+	    if (children[i].pipe_fd >= 0
+		&& FD_ISSET(children[i].pipe_fd, &readfds)) {
+		handle_child_signal (i);
 	    }
-#ifndef DEBUG
-	    /* if you want a sep daemon for each server */
-	    if ((pid = fork())) {
-		void *tmp;
-
-		/* parent */
-		if (pid < 0) {
-		    krb_log("fork: %s",error_message(errno));
-		    close(peer_fd);
-		    continue;
-		}
-		/* fork succeded: keep tabs on child */
-		close(peer_fd);
-		tmp = realloc(pidarray,
-			      (pidarraysize + 1) * sizeof(*pidarray));
-		if(tmp == NULL) {
-		    krb_log ("malloc: no memory. pid %u on its own",
-			     (unsigned)pid);
-		} else {
-		    pidarray = tmp;
-		    pidarray[pidarraysize++] = pid;
-		}
-	    } else {
-		/* child */
-		close(admin_fd);
-#endif /* DEBUG */
-		/*
-		 * If we are multihomed we need to figure out which
-		 * local address that is used this time since it is
-		 * used in "direction" comparison.
-		 */
-		getsockname(peer_fd,
-			    (struct sockaddr *)&server_parm.admin_addr,
-			    &addrlen);
-		/* do stuff */
-		process_client (peer_fd, &peer);
-#ifndef DEBUG
-	    }
-#endif
-	} else {
-	    krb_log("something else woke me up!");
-	    return(0);
-	}
     }
     /*NOTREACHED*/
 }
diff --git a/kerberosIV/src/kuser/klist.c b/kerberosIV/src/kuser/klist.c
index 2ee1c525990..33b5cf1adaa 100644
--- a/kerberosIV/src/kuser/klist.c
+++ b/kerberosIV/src/kuser/klist.c
@@ -22,7 +22,7 @@
 
 #include <parse_time.h>
 
-RCSID("$KTH: klist.c,v 1.44.2.2 1999/12/07 00:20:43 assar Exp $");
+RCSID("$KTH: klist.c,v 1.44.2.3 2000/10/18 20:38:29 assar Exp $");
 
 static int option_verbose = 0;
 
diff --git a/kerberosIV/src/man/kinit.1 b/kerberosIV/src/man/kinit.1
index babb22e057f..62eb984359b 100644
--- a/kerberosIV/src/man/kinit.1
+++ b/kerberosIV/src/man/kinit.1
@@ -1,4 +1,4 @@
-.\" $Id: kinit.1,v 1.3 2000/03/30 09:26:50 hin Exp $
+.\" $KTH: kinit.1,v 1.4.4.1 2000/10/10 13:26:51 assar Exp $
 .\" Copyright 1989 by the Massachusetts Institute of Technology.
 .\"
 .\" For copying and distribution information,
diff --git a/kerberosIV/src/server/kerberos.c b/kerberosIV/src/server/kerberos.c
index 8598e46ee9f..f68c9f66b34 100644
--- a/kerberosIV/src/server/kerberos.c
+++ b/kerberosIV/src/server/kerberos.c
@@ -9,7 +9,13 @@
 #include "config.h"
 #include "protos.h"
 
-RCSID("$KTH: kerberos.c,v 1.87.2.1 2000/06/23 03:14:04 assar Exp $");
+RCSID("$KTH: kerberos.c,v 1.87.2.3 2000/10/18 20:24:13 assar Exp $");
+
+/*
+ * If support for really large numbers of network interfaces is
+ * desired, define FD_SETSIZE to some suitable value.
+ */
+#define FD_SETSIZE (4*1024)
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -560,8 +566,8 @@ mksocket(struct descr *d, struct in_addr addr, int type,
     if ((sock = socket(AF_INET, type, 0)) < 0)
 	err (1, "socket");
     if (sock >= FD_SETSIZE) {
-	errno = EMFILE;
-        errx(1, "aborting: too many descriptors");
+        errno = EMFILE;
+	errx(1, "Aborting: too many descriptors");
     }
 #if defined(SO_REUSEADDR) && defined(HAVE_SETSOCKOPT)
     if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on,
@@ -976,13 +982,24 @@ read_socket(struct descr *n)
     }
 }
 
+static fd_set readfds;
+
 static void
-loop(struct descr *fds, int nfds)
+loop(struct descr *fds, int base_nfds)
 {
+    int nfds = base_nfds;
+    int max_tcp = min(FD_SETSIZE, getdtablesize()) - fds[base_nfds - 1].s;
+    if (max_tcp <= 10) {
+        errno = EMFILE;
+ 	errx(1, "Aborting: too many descriptors");
+    }
+    max_tcp -= 10;		/* We need a few extra for DB, logs, etc. */
+    if (max_tcp > 100) max_tcp = 100; /* Keep to some sane limit. */
+
     for (;;) {
 	int ret;
-        fd_set readfds;
 	struct timeval tv;
+	int next_timeout = 10;	/* In seconds */
 	int maxfd = 0;
 	struct descr *n, *minfree;
 	int accepted; /* accept at most one socket per `round' */
@@ -1005,12 +1022,15 @@ loop(struct descr *fds, int nfds)
 	    }
 	    FD_SET(n->s, &readfds);
 	    maxfd = max(maxfd, n->s);
+	    next_timeout = min(next_timeout, tv.tv_sec - n->timeout);
 	}
 	/* add more space for sockets */
-	if(minfree == NULL){
+	if (minfree == NULL && nfds < base_nfds + max_tcp) {
 	    int i = nfds;
 	    struct descr *new;
 	    nfds *=2;
+	    if (nfds > base_nfds + max_tcp)
+	        nfds = base_nfds + max_tcp;
 	    new = realloc(fds, sizeof(struct descr) * nfds);
 	    if(new){
 		fds = new;
@@ -1018,7 +1038,27 @@ loop(struct descr *fds, int nfds)
 		for(; i < nfds; i++) fds[i].s = -1;
 	    }
 	}
-	ret = select(maxfd + 1, &readfds, 0, 0, 0);
+	if (minfree == NULL) {
+	    /*
+	     * We are possibly the subject of a DOS attack, pick a TCP
+	     * connection at random and drop it.
+	     */
+	    int r = rand() % (nfds - base_nfds);
+	    r = r + base_nfds;
+	    FD_CLR(fds[r].s, &readfds);
+	    close(fds[r].s);
+	    fds[r].s = -1;
+	    minfree = &fds[r];
+	}
+	if (next_timeout < 0) next_timeout = 0;
+	tv.tv_sec = next_timeout;
+	tv.tv_usec = 0;
+	ret = select(maxfd + 1, &readfds, 0, 0, &tv);
+	if (ret < 0) {
+	    if (errno != EINTR)
+	        klog(L_KRB_PERR, "select: %s", strerror(errno));
+	  continue;
+	}
 	accepted = 0;
 	for (n = fds; n < fds + nfds; n++){
 	    if(n->s < 0) continue;
@@ -1031,7 +1071,6 @@ loop(struct descr *fds, int nfds)
 		    accepted = 1;
 		    s = accept(n->s, NULL, 0);
 		    if (minfree == NULL || s >= FD_SETSIZE) {
-			kerb_err_reply(s, NULL, KFAILURE, "Out of memory");
 			close(s);
 		    }else{
 			minfree->s = s;