faith translator deamon, from KAME

1 files changed, 298 insertions, 0 deletions

diff --git a/usr.sbin/faithd/tcp.c b/usr.sbin/faithd/tcp.c
new file mode 100644
index 00000000000..c11faea30dd
--- /dev/null
+++ b/usr.sbin/faithd/tcp.c
@@ -0,0 +1,298 @@
+/*
+ * Copyright (C) 1997 and 1998 WIDE Project.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include "faithd.h"
+
+static char tcpbuf[16*1024];
+	/* bigger than MSS and may be lesser than window size */
+static int tblen, tboff, oob_exists;
+static fd_set readfds, writefds, exceptfds;
+static char atmark_buf[2];
+static pid_t cpid = (pid_t)0;
+static pid_t ppid = (pid_t)0;
+static time_t child_lastactive = (time_t)0;
+static time_t parent_lastactive = (time_t)0;
+
+static void sig_ctimeout __P((int));
+static void sig_child __P((int));
+static void notify_inactive __P((void));
+static void notify_active __P((void));
+static void send_data __P((int, int, const char *, int));
+static void relay __P((int, int, const char *, int));
+
+/*
+ * Inactivity timer:
+ * - child side (ppid != 0) will send SIGUSR1 to parent every (FAITH_TIMEOUT/4)
+ *   second if traffic is active.  if traffic is inactive, don't send SIGUSR1.
+ * - parent side (ppid == 0) will check the last SIGUSR1 it have seen.
+ */
+static void
+sig_ctimeout(int sig)
+{
+	/* parent side: record notification from the child */
+	if (dflag)
+		syslog(LOG_DEBUG, "activity timer from child");
+	child_lastactive = time(NULL);
+}
+
+/* parent will terminate if child dies. */
+static void
+sig_child(int sig)
+{
+	int status;
+	pid_t pid;
+
+	pid = wait3(&status, WNOHANG, (struct rusage *)0);
+	if (pid && status)
+		syslog(LOG_WARNING, "child %d exit status 0x%x", pid, status);
+	exit_failure("terminate connection due to child termination");
+}
+
+static void
+notify_inactive()
+{
+	time_t t;
+
+	/* only on parent side... */
+	if (ppid)
+		return;
+
+	/* parent side should check for timeout. */
+	t = time(NULL);
+	if (dflag) {
+		syslog(LOG_DEBUG, "parent side %sactive, child side %sactive",
+			(FAITH_TIMEOUT < t - parent_lastactive) ? "in" : "",
+			(FAITH_TIMEOUT < t - child_lastactive) ? "in" : "");
+	}
+
+	if (FAITH_TIMEOUT < t - child_lastactive
+	 && FAITH_TIMEOUT < t - parent_lastactive) {
+		/* both side timeouted */
+		signal(SIGCHLD, SIG_DFL);
+		kill(cpid, SIGTERM);
+		wait(NULL);
+		exit_failure("connection timeout");
+		/* NOTREACHED */
+	}
+}
+
+static void
+notify_active()
+{
+	if (ppid) {
+		/* child side: notify parent of active traffic */
+		time_t t;
+		t = time(NULL);
+		if (FAITH_TIMEOUT / 4 < t - child_lastactive) {
+			if (kill(ppid, SIGUSR1) < 0) {
+				exit_failure("terminate connection due to parent termination");
+				/* NOTREACHED */
+			}
+			child_lastactive = t;
+		}
+	} else {
+		/* parent side */
+		parent_lastactive = time(NULL);
+	}
+}
+
+static void
+send_data(int s_rcv, int s_snd, const char *service, int direction)
+{
+	int cc;
+
+	if (oob_exists) {
+		cc = send(s_snd, atmark_buf, 1, MSG_OOB);
+		if (cc == -1)
+			goto retry_or_err;
+		oob_exists = 0;
+		FD_SET(s_rcv, &exceptfds);
+	}
+
+	for (; tboff < tblen; tboff += cc) {
+		cc = write(s_snd, tcpbuf + tboff, tblen - tboff);
+		if (cc < 0)
+			goto retry_or_err;
+	}
+#ifdef DEBUG
+	if (tblen) {
+		if (tblen >= sizeof(tcpbuf))
+			tblen = sizeof(tcpbuf) - 1;
+	    	tcpbuf[tblen] = '\0';
+		syslog(LOG_DEBUG, "from %s (%dbytes): %s",
+		       direction == 1 ? "client" : "server", tblen, tcpbuf);
+	}
+#endif /* DEBUG */
+	tblen = 0; tboff = 0;
+	FD_CLR(s_snd, &writefds);
+	FD_SET(s_rcv, &readfds);
+	return;
+    retry_or_err:
+	if (errno != EAGAIN)
+		exit_failure("writing relay data failed: %s", ERRSTR);
+	FD_SET(s_snd, &writefds);
+}
+
+static void
+relay(int s_rcv, int s_snd, const char *service, int direction)
+{
+	int atmark, error, maxfd;
+	struct timeval tv;
+	fd_set oreadfds, owritefds, oexceptfds;
+
+	FD_ZERO(&readfds);
+	FD_ZERO(&writefds);
+	FD_ZERO(&exceptfds);
+	fcntl(s_snd, F_SETFD, O_NONBLOCK);
+	oreadfds = readfds; owritefds = writefds; oexceptfds = exceptfds;
+	FD_SET(s_rcv, &readfds); FD_SET(s_rcv, &exceptfds);
+	oob_exists = 0;
+	maxfd = (s_rcv > s_snd) ? s_rcv : s_snd;
+
+	for (;;) {
+		tv.tv_sec = FAITH_TIMEOUT / 4;
+		tv.tv_usec = 0;
+		oreadfds = readfds;
+		owritefds = writefds;
+		oexceptfds = exceptfds;
+		error = select(maxfd + 1, &readfds, &writefds, &exceptfds, &tv);
+		if (error == -1) {
+			if (errno == EINTR)
+				continue;
+			exit_failure("select: %s", ERRSTR);
+		} else if (error == 0) {
+			readfds = oreadfds;
+			writefds = owritefds;
+			exceptfds = oexceptfds;
+			notify_inactive();
+			continue;
+		}
+
+		/* activity notification */
+		notify_active();
+
+		if (FD_ISSET(s_rcv, &exceptfds)) {
+			error = ioctl(s_rcv, SIOCATMARK, &atmark);
+			if (error != -1 && atmark == 1) {
+				int cc;
+			    oob_read_retry:
+				cc = read(s_rcv, atmark_buf, 1);
+				if (cc == 1) {
+					FD_CLR(s_rcv, &exceptfds);
+					FD_SET(s_snd, &writefds);
+					oob_exists = 1;
+				} else if (cc == -1) {
+					if (errno == EINTR)
+						goto oob_read_retry;
+					exit_failure("reading oob data failed"
+						     ": %s",
+						     ERRSTR);
+				}
+			}
+		}
+		if (FD_ISSET(s_rcv, &readfds)) {
+		    relaydata_read_retry:
+			tblen = read(s_rcv, tcpbuf, sizeof(tcpbuf));
+			tboff = 0;
+
+			switch (tblen) {
+			case -1:
+				if (errno == EINTR)
+					goto relaydata_read_retry;
+				exit_failure("reading relay data failed: %s",
+					     ERRSTR);
+				/* NOTREACHED */
+			case 0:
+				/* to close opposite-direction relay process */
+				shutdown(s_snd, 0);
+
+				close(s_rcv);
+				close(s_snd);
+				exit_success("terminating %s relay", service);
+				/* NOTREACHED */
+			default:
+				FD_CLR(s_rcv, &readfds);
+				FD_SET(s_snd, &writefds);
+				break;
+			}
+		}
+		if (FD_ISSET(s_snd, &writefds))
+			send_data(s_rcv, s_snd, service, direction);
+	}
+}
+
+void
+tcp_relay(int s_src, int s_dst, const char *service)
+{
+	syslog(LOG_INFO, "starting %s relay", service);
+
+	child_lastactive = parent_lastactive = time(NULL);
+
+	cpid = fork();
+	switch (cpid) {
+	case -1:
+		exit_failure("tcp_relay: can't fork grand child: %s", ERRSTR);
+		/* NOTREACHED */
+	case 0:
+		/* child process: relay going traffic */
+		ppid = getppid();
+		/* this is child so reopen log */
+		closelog();
+		openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
+		relay(s_src, s_dst, service, 1);
+		/* NOTREACHED */
+	default:
+		/* parent process: relay coming traffic */
+		ppid = (pid_t)0;
+		signal(SIGUSR1, sig_ctimeout);
+		signal(SIGCHLD, sig_child);
+		relay(s_dst, s_src, service, 0);
+		/* NOTREACHED */
+	}
+}