]> andersk Git - openssh.git/blobdiff - serverloop.c
- millert@cvs.openbsd.org 2001/03/04 17:42:28
[openssh.git] / serverloop.c
index 958c9661eb8f7dad60085e5a8bd896441cde59ae..8b1ee99190cb82a12fa8164454f18facc62ed181 100644 (file)
@@ -11,7 +11,7 @@
  * called by a name other than "ssh" or "Secure Shell".
  *
  * SSH2 support by Markus Friedl.
- * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: serverloop.c,v 1.40 2001/01/18 17:00:00 markus Exp $");
+RCSID("$OpenBSD: serverloop.c,v 1.54 2001/03/04 01:46:30 djm Exp $");
 
 #include "xmalloc.h"
-#include "ssh.h"
 #include "packet.h"
 #include "buffer.h"
+#include "log.h"
 #include "servconf.h"
-#include "pty.h"
+#include "sshpty.h"
 #include "channels.h"
-
 #include "compat.h"
+#include "ssh1.h"
 #include "ssh2.h"
 #include "auth.h"
 #include "session.h"
 #include "dispatch.h"
 #include "auth-options.h"
+#include "serverloop.h"
+#include "misc.h"
 
 extern ServerOptions options;
 
@@ -68,10 +70,10 @@ static long fdout_bytes = 0;        /* Number of stdout bytes read from program. */
 static int stdin_eof = 0;      /* EOF message received from client. */
 static int fdout_eof = 0;      /* EOF encountered reading from fdout. */
 static int fderr_eof = 0;      /* EOF encountered readung from fderr. */
+static int fdin_is_tty = 0;    /* fdin points to a tty. */
 static int connection_in;      /* Connection to client (input). */
 static int connection_out;     /* Connection to client (output). */
 static u_int buffer_high;/* "Soft" max buffer size. */
-static int max_fd;             /* Max file descriptor number for select(). */
 
 /*
  * This SIGCHLD kludge is used to detect when the child exits.  The server
@@ -109,7 +111,7 @@ sigchld_handler2(int sig)
        int save_errno = errno;
        debug("Received SIGCHLD.");
        child_terminated = 1;
-       signal(SIGCHLD, sigchld_handler2);
+       mysignal(SIGCHLD, sigchld_handler2);
        errno = save_errno;
 }
 
@@ -118,7 +120,7 @@ sigchld_handler2(int sig)
  * to the client.
  */
 void
-make_packets_from_stderr_data()
+make_packets_from_stderr_data(void)
 {
        int len;
 
@@ -147,7 +149,7 @@ make_packets_from_stderr_data()
  * client.
  */
 void
-make_packets_from_stdout_data()
+make_packets_from_stdout_data(void)
 {
        int len;
 
@@ -161,7 +163,7 @@ make_packets_from_stdout_data()
                } else {
                        /* Keep the packets at reasonable size. */
                        if (len > packet_get_maxsize())
-                               len = packet_get_maxsize();     
+                               len = packet_get_maxsize();
                }
                packet_start(SSH_SMSG_STDOUT_DATA);
                packet_put_string(buffer_ptr(&stdout_buffer), len);
@@ -178,8 +180,8 @@ make_packets_from_stdout_data()
  * for the duration of the wait (0 = infinite).
  */
 void
-wait_until_can_do_something(fd_set * readset, fd_set * writeset,
-                           u_int max_time_milliseconds)
+wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
+    u_int max_time_milliseconds)
 {
        struct timeval tv, *tvp;
        int ret;
@@ -187,14 +189,13 @@ wait_until_can_do_something(fd_set * readset, fd_set * writeset,
        /* When select fails we restart from here. */
 retry_select:
 
-       /* Initialize select() masks. */
-       FD_ZERO(readset);
-       FD_ZERO(writeset);
+       /* Allocate and update select() masks for channel descriptors. */
+       channel_prepare_select(readsetp, writesetp, maxfdp);
 
        if (compat20) {
                /* wrong: bad condition XXX */
                if (channel_not_very_much_buffered_data())
-                       FD_SET(connection_in, readset);
+                       FD_SET(connection_in, *readsetp);
        } else {
                /*
                 * Read packets from the client unless we have too much
@@ -202,37 +203,31 @@ retry_select:
                 */
                if (buffer_len(&stdin_buffer) < buffer_high &&
                    channel_not_very_much_buffered_data())
-                       FD_SET(connection_in, readset);
+                       FD_SET(connection_in, *readsetp);
                /*
                 * If there is not too much data already buffered going to
                 * the client, try to get some more data from the program.
                 */
                if (packet_not_very_much_data_to_write()) {
                        if (!fdout_eof)
-                               FD_SET(fdout, readset);
+                               FD_SET(fdout, *readsetp);
                        if (!fderr_eof)
-                               FD_SET(fderr, readset);
+                               FD_SET(fderr, *readsetp);
                }
                /*
                 * If we have buffered data, try to write some of that data
                 * to the program.
                 */
                if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
-                       FD_SET(fdin, writeset);
+                       FD_SET(fdin, *writesetp);
        }
-       /* Set masks for channel descriptors. */
-       channel_prepare_select(readset, writeset);
 
        /*
         * If we have buffered packet data going to the client, mark that
         * descriptor.
         */
        if (packet_have_data_to_write())
-               FD_SET(connection_out, writeset);
-
-       /* Update the maximum descriptor number if appropriate. */
-       if (channel_max_fd() > max_fd)
-               max_fd = channel_max_fd();
+               FD_SET(connection_out, *writesetp);
 
        /*
         * If child has terminated and there is enough buffer space to read
@@ -250,10 +245,10 @@ retry_select:
                tvp = &tv;
        }
        if (tvp!=NULL)
-               debug2("tvp!=NULL kid %d mili %d", child_terminated, max_time_milliseconds);
+               debug3("tvp!=NULL kid %d mili %d", child_terminated, max_time_milliseconds);
 
        /* Wait for something to happen, or the timeout to expire. */
-       ret = select(max_fd + 1, readset, writeset, NULL, tvp);
+       ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
 
        if (ret < 0) {
                if (errno != EINTR)
@@ -323,6 +318,7 @@ process_input(fd_set * readset)
 void
 process_output(fd_set * writeset)
 {
+       struct termios tio;
        int len;
 
        /* Write buffered data to program stdin. */
@@ -342,7 +338,17 @@ process_output(fd_set * writeset)
 #endif
                        fdin = -1;
                } else {
-                       /* Successful write.  Consume the data from the buffer. */
+                       /* Successful write. */
+                       if (fdin_is_tty && tcgetattr(fdin, &tio) == 0 &&
+                           !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
+                               /*
+                                * Simulate echo to reduce the impact of
+                                * traffic analysis
+                                */
+                               packet_send_ignore(len);
+                               packet_send();
+                       }
+                       /* Consume the data from the buffer. */
                        buffer_consume(&stdin_buffer, len);
                        /* Update the count of bytes written to the program. */
                        stdin_bytes += len;
@@ -358,7 +364,7 @@ process_output(fd_set * writeset)
  * This is used when the program terminates.
  */
 void
-drain_output()
+drain_output(void)
 {
        /* Send any buffered stdout data to the client. */
        if (buffer_len(&stdout_buffer) > 0) {
@@ -383,7 +389,7 @@ drain_output()
 }
 
 void
-process_buffered_input_packets()
+process_buffered_input_packets(void)
 {
        dispatch_run(DISPATCH_NONBLOCK, NULL, NULL);
 }
@@ -398,7 +404,8 @@ process_buffered_input_packets()
 void
 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 {
-       fd_set readset, writeset;
+       fd_set *readset = NULL, *writeset = NULL;
+       int max_fd;
        int wait_status;        /* Status returned by wait(). */
        pid_t wait_pid;         /* pid returned by wait(). */
        int waiting_termination = 0;    /* Have displayed waiting close message. */
@@ -427,6 +434,9 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
        if (fderr != -1)
                set_nonblock(fderr);
 
+       if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
+               fdin_is_tty = 1;
+
        connection_in = packet_get_connection_in();
        connection_out = packet_get_connection_out();
 
@@ -439,15 +449,11 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
                buffer_high = 64 * 1024;
 
        /* Initialize max_fd to the maximum of the known file descriptors. */
-       max_fd = fdin;
-       if (fdout > max_fd)
-               max_fd = fdout;
-       if (fderr != -1 && fderr > max_fd)
-               max_fd = fderr;
-       if (connection_in > max_fd)
-               max_fd = connection_in;
-       if (connection_out > max_fd)
-               max_fd = connection_out;
+       max_fd = MAX(fdin, fdout);
+       if (fderr != -1)
+               max_fd = MAX(max_fd, fderr);
+       max_fd = MAX(max_fd, connection_in);
+       max_fd = MAX(max_fd, connection_out);
 
        /* Initialize Initialize buffers. */
        buffer_init(&stdin_buffer);
@@ -534,18 +540,22 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
                        }
                }
                /* Sleep in select() until we can do something. */
-               wait_until_can_do_something(&readset, &writeset,
-                                           max_time_milliseconds);
+               wait_until_can_do_something(&readset, &writeset, &max_fd,
+                   max_time_milliseconds);
 
                /* Process any channel events. */
-               channel_after_select(&readset, &writeset);
+               channel_after_select(readset, writeset);
 
                /* Process input from the client and from program stdout/stderr. */
-               process_input(&readset);
+               process_input(readset);
 
                /* Process output to the client and to program stdin. */
-               process_output(&writeset);
+               process_output(writeset);
        }
+       if (readset)
+               xfree(readset);
+       if (writeset)
+               xfree(writeset);
 
        /* Cleanup and termination code. */
 
@@ -636,21 +646,22 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 void
 server_loop2(void)
 {
-       fd_set readset, writeset;
+       fd_set *readset = NULL, *writeset = NULL;
+       int max_fd;
        int had_channel = 0;
        int status;
        pid_t pid;
 
        debug("Entering interactive session for SSH2.");
 
-       signal(SIGCHLD, sigchld_handler2);
+       mysignal(SIGCHLD, sigchld_handler2);
        signal(SIGPIPE, SIG_IGN);
        child_terminated = 0;
        connection_in = packet_get_connection_in();
        connection_out = packet_get_connection_out();
-       max_fd = connection_in;
-       if (connection_out > max_fd)
-               max_fd = connection_out;
+
+       max_fd = MAX(connection_in, connection_out);
+
        server_init_dispatch();
 
        for (;;) {
@@ -663,16 +674,21 @@ server_loop2(void)
                }
                if (packet_not_very_much_data_to_write())
                        channel_output_poll();
-               wait_until_can_do_something(&readset, &writeset, 0);
+               wait_until_can_do_something(&readset, &writeset, &max_fd, 0);
                if (child_terminated) {
                        while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
                                session_close_by_pid(pid, status);
                        child_terminated = 0;
                }
-               channel_after_select(&readset, &writeset);
-               process_input(&readset);
-               process_output(&writeset);
+               channel_after_select(readset, writeset);
+               process_input(readset);
+               process_output(writeset);
        }
+       if (readset)
+               xfree(readset);
+       if (writeset)
+               xfree(writeset);
+
        signal(SIGCHLD, SIG_DFL);
        while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
                session_close_by_pid(pid, status);
@@ -831,7 +847,7 @@ server_input_channel_open(int type, int plen, void *ctxt)
        xfree(ctype);
 }
 
-void 
+void
 server_input_global_request(int type, int plen, void *ctxt)
 {
        char *rtype;
@@ -841,7 +857,7 @@ server_input_global_request(int type, int plen, void *ctxt)
        rtype = packet_get_string(NULL);
        want_reply = packet_get_char();
        debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
-       
+
        if (strcmp(rtype, "tcpip-forward") == 0) {
                struct passwd *pw;
                char *listen_address;
@@ -863,12 +879,11 @@ server_input_global_request(int type, int plen, void *ctxt)
                        packet_send_debug("Server has disabled port forwarding.");
                } else {
                        /* Start listening on the port */
-                       channel_request_forwarding(
+                       success = channel_request_forwarding(
                            listen_address, listen_port,
                            /*unspec host_to_connect*/ "<unspec host>",
                            /*unspec port_to_connect*/ 0,
                            options.gateway_ports, /*remote*/ 1);
-                       success = 1;
                }
                xfree(listen_address);
        }
@@ -882,7 +897,7 @@ server_input_global_request(int type, int plen, void *ctxt)
 }
 
 void
-server_init_dispatch_20()
+server_init_dispatch_20(void)
 {
        debug("server_init_dispatch_20");
        dispatch_init(&dispatch_protocol_error);
@@ -898,7 +913,7 @@ server_init_dispatch_20()
        dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
 }
 void
-server_init_dispatch_13()
+server_init_dispatch_13(void)
 {
        debug("server_init_dispatch_13");
        dispatch_init(NULL);
@@ -913,7 +928,7 @@ server_init_dispatch_13()
        dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
 }
 void
-server_init_dispatch_15()
+server_init_dispatch_15(void)
 {
        server_init_dispatch_13();
        debug("server_init_dispatch_15");
@@ -921,7 +936,7 @@ server_init_dispatch_15()
        dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
 }
 void
-server_init_dispatch()
+server_init_dispatch(void)
 {
        if (compat20)
                server_init_dispatch_20();
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