/*
-
-serverloop.c
-
-Author: Tatu Ylonen <ylo@cs.hut.fi>
-
-Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- All rights reserved
-
-Created: Sun Sep 10 00:30:37 1995 ylo
-
-Server main loop for handling the interactive session.
-
-*/
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ * Server main loop for handling the interactive session.
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ * SSH2 support by Markus Friedl.
+ * 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
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 "includes.h"
+RCSID("$OpenBSD: serverloop.c,v 1.34 2000/10/27 07:32:18 markus Exp $");
+
#include "xmalloc.h"
#include "ssh.h"
#include "packet.h"
#include "buffer.h"
#include "servconf.h"
#include "pty.h"
+#include "channels.h"
+
+#include "compat.h"
+#include "ssh2.h"
+#include "session.h"
+#include "dispatch.h"
+#include "auth-options.h"
+
+extern ServerOptions options;
static Buffer stdin_buffer; /* Buffer for stdin data. */
static Buffer stdout_buffer; /* Buffer for stdout data. */
static unsigned 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
- will exit after that, as soon as forwarded connections have terminated. */
-
-static int child_pid; /* Pid of the child. */
+/*
+ * This SIGCHLD kludge is used to detect when the child exits. The server
+ * will exit after that, as soon as forwarded connections have terminated.
+ *
+ * After SIGCHLD child_has_selected is set to 1 after the first pass
+ * through the wait_until_can_do_something() select(). This ensures
+ * that the child's output gets a chance to drain before it is yanked.
+ */
+
+static pid_t child_pid; /* Pid of the child. */
static volatile int child_terminated; /* The child has terminated. */
+static volatile int child_has_selected; /* Child has had chance to drain. */
static volatile int child_wait_status; /* Status from wait(). */
-void sigchld_handler(int sig)
-{
- int save_errno = errno;
- int wait_pid;
- debug("Received SIGCHLD.");
- wait_pid = wait((int *)&child_wait_status);
- if (wait_pid != -1)
- {
- if (wait_pid != child_pid)
- error("Strange, got SIGCHLD and wait returned pid %d but child is %d",
- wait_pid, child_pid);
- if (WIFEXITED(child_wait_status) ||
- WIFSIGNALED(child_wait_status))
- child_terminated = 1;
- }
- signal(SIGCHLD, sigchld_handler);
- errno = save_errno;
-}
-
-/* Process any buffered packets that have been received from the client. */
+void server_init_dispatch(void);
-void process_buffered_input_packets()
+void
+sigchld_handler(int sig)
{
- int type;
- char *data;
- unsigned int data_len;
- int row, col, xpixel, ypixel;
- int payload_len;
-
- /* Process buffered packets from the client. */
- while ((type = packet_read_poll(&payload_len)) != SSH_MSG_NONE)
- {
- switch (type)
- {
- case SSH_CMSG_STDIN_DATA:
- /* Stdin data from the client. Append it to the buffer. */
- if (fdin == -1)
- break; /* Ignore any data if the client has closed stdin. */
- data = packet_get_string(&data_len);
- packet_integrity_check(payload_len, (4 + data_len), type);
- buffer_append(&stdin_buffer, data, data_len);
- memset(data, 0, data_len);
- xfree(data);
- break;
-
- case SSH_CMSG_EOF:
- /* Eof from the client. The stdin descriptor to the program
- will be closed when all buffered data has drained. */
- debug("EOF received for stdin.");
- packet_integrity_check(payload_len, 0, type);
- stdin_eof = 1;
- break;
-
- case SSH_CMSG_WINDOW_SIZE:
- debug("Window change received.");
- packet_integrity_check(payload_len, 4*4, type);
- row = packet_get_int();
- col = packet_get_int();
- xpixel = packet_get_int();
- ypixel = packet_get_int();
- if (fdin != -1)
- pty_change_window_size(fdin, row, col, xpixel, ypixel);
- break;
-
- case SSH_MSG_PORT_OPEN:
- debug("Received port open request.");
- channel_input_port_open(payload_len);
- break;
-
- case SSH_MSG_CHANNEL_OPEN_CONFIRMATION:
- debug("Received channel open confirmation.");
- packet_integrity_check(payload_len, 4 + 4, type);
- channel_input_open_confirmation();
- break;
-
- case SSH_MSG_CHANNEL_OPEN_FAILURE:
- debug("Received channel open failure.");
- packet_integrity_check(payload_len, 4, type);
- channel_input_open_failure();
- break;
-
- case SSH_MSG_CHANNEL_DATA:
- channel_input_data(payload_len);
- break;
-
- case SSH_MSG_CHANNEL_CLOSE:
- debug("Received channel close.");
- packet_integrity_check(payload_len, 4, type);
- channel_input_close();
- break;
-
- case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION:
- debug("Received channel close confirmation.");
- packet_integrity_check(payload_len, 4, type);
- channel_input_close_confirmation();
- break;
-
- default:
- /* In this phase, any unexpected messages cause a protocol
- error. This is to ease debugging; also, since no
- confirmations are sent messages, unprocessed unknown
- messages could cause strange problems. Any compatible
- protocol extensions must be negotiated before entering the
- interactive session. */
- packet_disconnect("Protocol error during session: type %d",
- type);
+ int save_errno = errno;
+ pid_t wait_pid;
+
+ debug("Received SIGCHLD.");
+ wait_pid = wait((int *) &child_wait_status);
+ if (wait_pid != -1) {
+ if (wait_pid != child_pid)
+ error("Strange, got SIGCHLD and wait returned pid %d but child is %d",
+ wait_pid, child_pid);
+ if (WIFEXITED(child_wait_status) ||
+ WIFSIGNALED(child_wait_status)) {
+ child_terminated = 1;
+ child_has_selected = 0;
+ }
}
- }
+ signal(SIGCHLD, sigchld_handler);
+ errno = save_errno;
+}
+void
+sigchld_handler2(int sig)
+{
+ int save_errno = errno;
+ debug("Received SIGCHLD.");
+ child_terminated = 1;
+ child_has_selected = 0;
+ errno = save_errno;
}
-/* Make packets from buffered stderr data, and buffer it for sending
- to the client. */
-
-void make_packets_from_stderr_data()
+/*
+ * Make packets from buffered stderr data, and buffer it for sending
+ * to the client.
+ */
+void
+make_packets_from_stderr_data()
{
- int len;
-
- /* Send buffered stderr data to the client. */
- while (buffer_len(&stderr_buffer) > 0 &&
- packet_not_very_much_data_to_write())
- {
- len = buffer_len(&stderr_buffer);
- if (packet_is_interactive())
- {
- if (len > 512)
- len = 512;
+ int len;
+
+ /* Send buffered stderr data to the client. */
+ while (buffer_len(&stderr_buffer) > 0 &&
+ packet_not_very_much_data_to_write()) {
+ len = buffer_len(&stderr_buffer);
+ if (packet_is_interactive()) {
+ if (len > 512)
+ len = 512;
+ } else {
+ /* Keep the packets at reasonable size. */
+ if (len > packet_get_maxsize())
+ len = packet_get_maxsize();
+ }
+ packet_start(SSH_SMSG_STDERR_DATA);
+ packet_put_string(buffer_ptr(&stderr_buffer), len);
+ packet_send();
+ buffer_consume(&stderr_buffer, len);
+ stderr_bytes += len;
}
- else
- {
- if (len > 32768)
- len = 32768; /* Keep the packets at reasonable size. */
- }
- packet_start(SSH_SMSG_STDERR_DATA);
- packet_put_string(buffer_ptr(&stderr_buffer), len);
- packet_send();
- buffer_consume(&stderr_buffer, len);
- stderr_bytes += len;
- }
}
-/* Make packets from buffered stdout data, and buffer it for sending to the
- client. */
-
-void make_packets_from_stdout_data()
+/*
+ * Make packets from buffered stdout data, and buffer it for sending to the
+ * client.
+ */
+void
+make_packets_from_stdout_data()
{
- int len;
-
- /* Send buffered stdout data to the client. */
- while (buffer_len(&stdout_buffer) > 0 &&
- packet_not_very_much_data_to_write())
- {
- len = buffer_len(&stdout_buffer);
- if (packet_is_interactive())
- {
- if (len > 512)
- len = 512;
+ int len;
+
+ /* Send buffered stdout data to the client. */
+ while (buffer_len(&stdout_buffer) > 0 &&
+ packet_not_very_much_data_to_write()) {
+ len = buffer_len(&stdout_buffer);
+ if (packet_is_interactive()) {
+ if (len > 512)
+ len = 512;
+ } else {
+ /* Keep the packets at reasonable size. */
+ if (len > packet_get_maxsize())
+ len = packet_get_maxsize();
+ }
+ packet_start(SSH_SMSG_STDOUT_DATA);
+ packet_put_string(buffer_ptr(&stdout_buffer), len);
+ packet_send();
+ buffer_consume(&stdout_buffer, len);
+ stdout_bytes += len;
}
- else
- {
- if (len > 32768)
- len = 32768; /* Keep the packets at reasonable size. */
- }
- packet_start(SSH_SMSG_STDOUT_DATA);
- packet_put_string(buffer_ptr(&stdout_buffer), len);
- packet_send();
- buffer_consume(&stdout_buffer, len);
- stdout_bytes += len;
- }
}
-/* Sleep in select() until we can do something. This will initialize the
- select masks. Upon return, the masks will indicate which descriptors
- have data or can accept data. Optionally, a maximum time can be specified
- for the duration of the wait (0 = infinite). */
-
-void wait_until_can_do_something(fd_set *readset, fd_set *writeset,
- unsigned int max_time_milliseconds)
+/*
+ * Sleep in select() until we can do something. This will initialize the
+ * select masks. Upon return, the masks will indicate which descriptors
+ * have data or can accept data. Optionally, a maximum time can be specified
+ * for the duration of the wait (0 = infinite).
+ */
+void
+wait_until_can_do_something(fd_set * readset, fd_set * writeset,
+ unsigned int max_time_milliseconds)
{
- struct timeval tv, *tvp;
- int ret;
+ struct timeval tv, *tvp;
+ int ret;
- /* When select fails we restart from here. */
+ /* When select fails we restart from here. */
retry_select:
- /* Initialize select() masks. */
- FD_ZERO(readset);
-
- /* Read packets from the client unless we have too much buffered stdin
- or channel data. */
- if (buffer_len(&stdin_buffer) < 4096 &&
- channel_not_very_much_buffered_data())
- FD_SET(connection_in, readset);
-
- /* 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);
- if (!fderr_eof)
- FD_SET(fderr, readset);
- }
-
- FD_ZERO(writeset);
-
- /* 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);
-
- /* 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);
-
- /* Update the maximum descriptor number if appropriate. */
- if (channel_max_fd() > max_fd)
- max_fd = channel_max_fd();
-
- /* If child has terminated, read as much as is available and then exit. */
- if (child_terminated)
- if (max_time_milliseconds == 0)
- max_time_milliseconds = 100;
-
- if (max_time_milliseconds == 0)
- tvp = NULL;
- else
- {
- tv.tv_sec = max_time_milliseconds / 1000;
- tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
- tvp = &tv;
- }
-
- /* Wait for something to happen, or the timeout to expire. */
- ret = select(max_fd + 1, readset, writeset, NULL, tvp);
-
- if (ret < 0)
- {
- if (errno != EINTR)
- error("select: %.100s", strerror(errno));
- else
- goto retry_select;
- }
-}
+ /* Initialize select() masks. */
+ FD_ZERO(readset);
+ FD_ZERO(writeset);
+
+ if (compat20) {
+ /* wrong: bad condition XXX */
+ if (channel_not_very_much_buffered_data())
+ FD_SET(connection_in, readset);
+ } else {
+ /*
+ * Read packets from the client unless we have too much
+ * buffered stdin or channel data.
+ */
+ if (buffer_len(&stdin_buffer) < buffer_high &&
+ channel_not_very_much_buffered_data())
+ FD_SET(connection_in, readset);
+ /*
+ * 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);
+ if (!fderr_eof)
+ FD_SET(fderr, readset);
+ }
+ /*
+ * 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);
+ }
+ /* 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();
+
+ /*
+ * If child has terminated and there is enough buffer space to read
+ * from it, then read as much as is available and exit.
+ */
+ if (child_terminated && packet_not_very_much_data_to_write())
+ if (max_time_milliseconds == 0)
+ max_time_milliseconds = 100;
+
+ if (max_time_milliseconds == 0)
+ tvp = NULL;
+ else {
+ tv.tv_sec = max_time_milliseconds / 1000;
+ tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
+ tvp = &tv;
+ }
+ if (tvp!=NULL)
+ debug("tvp!=NULL kid %d mili %d", child_terminated, max_time_milliseconds);
-/* Processes input from the client and the program. Input data is stored
- in buffers and processed later. */
+ /* Wait for something to happen, or the timeout to expire. */
+ ret = select(max_fd + 1, readset, writeset, NULL, tvp);
-void process_input(fd_set *readset)
-{
- int len;
- char buf[16384];
-
- /* Read and buffer any input data from the client. */
- if (FD_ISSET(connection_in, readset))
- {
- len = read(connection_in, buf, sizeof(buf));
- if (len == 0)
- fatal("Connection closed by remote host.");
-
- /* There is a kernel bug on Solaris that causes select to sometimes
- wake up even though there is no data available. */
- if (len < 0 && errno == EAGAIN)
- len = 0;
-
- if (len < 0)
- fatal("Read error from remote host: %.100s", strerror(errno));
-
- /* Buffer any received data. */
- packet_process_incoming(buf, len);
- }
-
- /* Read and buffer any available stdout data from the program. */
- if (!fdout_eof && FD_ISSET(fdout, readset))
- {
- len = read(fdout, buf, sizeof(buf));
- if (len <= 0)
- fdout_eof = 1;
- else
- {
- buffer_append(&stdout_buffer, buf, len);
- fdout_bytes += len;
+ if (ret < 0) {
+ if (errno != EINTR)
+ error("select: %.100s", strerror(errno));
+ else
+ goto retry_select;
}
- }
-
- /* Read and buffer any available stderr data from the program. */
- if (!fderr_eof && FD_ISSET(fderr, readset))
- {
- len = read(fderr, buf, sizeof(buf));
- if (len <= 0)
- fderr_eof = 1;
- else
- buffer_append(&stderr_buffer, buf, len);
- }
+
+ if (child_terminated)
+ child_has_selected = 1;
}
-/* Sends data from internal buffers to client program stdin. */
+/*
+ * Processes input from the client and the program. Input data is stored
+ * in buffers and processed later.
+ */
+void
+process_input(fd_set * readset)
+{
+ int len;
+ char buf[16384];
+
+ /* Read and buffer any input data from the client. */
+ if (FD_ISSET(connection_in, readset)) {
+ len = read(connection_in, buf, sizeof(buf));
+ if (len == 0) {
+ verbose("Connection closed by remote host.");
+ fatal_cleanup();
+ } else if (len < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ verbose("Read error from remote host: %.100s", strerror(errno));
+ fatal_cleanup();
+ }
+ } else {
+ /* Buffer any received data. */
+ packet_process_incoming(buf, len);
+ }
+ }
+ if (compat20)
+ return;
+
+ /* Read and buffer any available stdout data from the program. */
+ if (!fdout_eof && FD_ISSET(fdout, readset)) {
+ len = read(fdout, buf, sizeof(buf));
+ if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
+ /* do nothing */
+ } else if (len <= 0) {
+ fdout_eof = 1;
+ } else {
+ buffer_append(&stdout_buffer, buf, len);
+ fdout_bytes += len;
+ }
+ }
+ /* Read and buffer any available stderr data from the program. */
+ if (!fderr_eof && FD_ISSET(fderr, readset)) {
+ len = read(fderr, buf, sizeof(buf));
+ if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
+ /* do nothing */
+ } else if (len <= 0) {
+ fderr_eof = 1;
+ } else {
+ buffer_append(&stderr_buffer, buf, len);
+ }
+ }
+}
-void process_output(fd_set *writeset)
+/*
+ * Sends data from internal buffers to client program stdin.
+ */
+void
+process_output(fd_set * writeset)
{
- int len;
-
- /* Write buffered data to program stdin. */
- if (fdin != -1 && FD_ISSET(fdin, writeset))
- {
- len = write(fdin, buffer_ptr(&stdin_buffer),
- buffer_len(&stdin_buffer));
- if (len <= 0)
- {
+ int len;
+
+ /* Write buffered data to program stdin. */
+ if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
+ len = write(fdin, buffer_ptr(&stdin_buffer),
+ buffer_len(&stdin_buffer));
+ if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
+ /* do nothing */
+ } else if (len <= 0) {
#ifdef USE_PIPES
- close(fdin);
+ close(fdin);
#else
- if (fdout == -1)
- close(fdin);
- else
- shutdown(fdin, SHUT_WR); /* We will no longer send. */
+ if (fdin != fdout)
+ close(fdin);
+ else
+ shutdown(fdin, SHUT_WR); /* We will no longer send. */
#endif
- fdin = -1;
- }
- else
- {
- /* Successful write. Consume the data from the buffer. */
- buffer_consume(&stdin_buffer, len);
- /* Update the count of bytes written to the program. */
- stdin_bytes += len;
+ fdin = -1;
+ } else {
+ /* Successful write. Consume the data from the buffer. */
+ buffer_consume(&stdin_buffer, len);
+ /* Update the count of bytes written to the program. */
+ stdin_bytes += len;
+ }
}
- }
-
- /* Send any buffered packet data to the client. */
- if (FD_ISSET(connection_out, writeset))
- packet_write_poll();
+ /* Send any buffered packet data to the client. */
+ if (FD_ISSET(connection_out, writeset))
+ packet_write_poll();
}
-/* Wait until all buffered output has been sent to the client.
- This is used when the program terminates. */
-
-void drain_output()
+/*
+ * Wait until all buffered output has been sent to the client.
+ * This is used when the program terminates.
+ */
+void
+drain_output()
{
- /* Send any buffered stdout data to the client. */
- if (buffer_len(&stdout_buffer) > 0)
- {
- packet_start(SSH_SMSG_STDOUT_DATA);
- packet_put_string(buffer_ptr(&stdout_buffer),
- buffer_len(&stdout_buffer));
- packet_send();
- /* Update the count of sent bytes. */
- stdout_bytes += buffer_len(&stdout_buffer);
- }
-
- /* Send any buffered stderr data to the client. */
- if (buffer_len(&stderr_buffer) > 0)
- {
- packet_start(SSH_SMSG_STDERR_DATA);
- packet_put_string(buffer_ptr(&stderr_buffer),
- buffer_len(&stderr_buffer));
- packet_send();
- /* Update the count of sent bytes. */
- stderr_bytes += buffer_len(&stderr_buffer);
- }
-
- /* Wait until all buffered data has been written to the client. */
- packet_write_wait();
+ /* Send any buffered stdout data to the client. */
+ if (buffer_len(&stdout_buffer) > 0) {
+ packet_start(SSH_SMSG_STDOUT_DATA);
+ packet_put_string(buffer_ptr(&stdout_buffer),
+ buffer_len(&stdout_buffer));
+ packet_send();
+ /* Update the count of sent bytes. */
+ stdout_bytes += buffer_len(&stdout_buffer);
+ }
+ /* Send any buffered stderr data to the client. */
+ if (buffer_len(&stderr_buffer) > 0) {
+ packet_start(SSH_SMSG_STDERR_DATA);
+ packet_put_string(buffer_ptr(&stderr_buffer),
+ buffer_len(&stderr_buffer));
+ packet_send();
+ /* Update the count of sent bytes. */
+ stderr_bytes += buffer_len(&stderr_buffer);
+ }
+ /* Wait until all buffered data has been written to the client. */
+ packet_write_wait();
}
-/* Performs the interactive session. This handles data transmission between
- the client and the program. Note that the notion of stdin, stdout, and
- stderr in this function is sort of reversed: this function writes to
- stdin (of the child program), and reads from stdout and stderr (of the
- child program). */
+void
+process_buffered_input_packets()
+{
+ dispatch_run(DISPATCH_NONBLOCK, NULL, NULL);
+}
-void server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg)
+/*
+ * Performs the interactive session. This handles data transmission between
+ * the client and the program. Note that the notion of stdin, stdout, and
+ * stderr in this function is sort of reversed: this function writes to
+ * stdin (of the child program), and reads from stdout and stderr (of the
+ * child program).
+ */
+void
+server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
{
- int wait_status, wait_pid; /* Status and pid returned by wait(). */
- int waiting_termination = 0; /* Have displayed waiting close message. */
- unsigned int max_time_milliseconds;
- unsigned int previous_stdout_buffer_bytes;
- unsigned int stdout_buffer_bytes;
- int type;
-
- debug("Entering interactive session.");
-
- /* Initialize the SIGCHLD kludge. */
- child_pid = pid;
- child_terminated = 0;
- signal(SIGCHLD, sigchld_handler);
-
- /* Initialize our global variables. */
- fdin = fdin_arg;
- fdout = fdout_arg;
- fderr = fderr_arg;
- connection_in = packet_get_connection_in();
- connection_out = packet_get_connection_out();
-
- previous_stdout_buffer_bytes = 0;
-
- /* Set approximate I/O buffer size. */
- if (packet_is_interactive())
- buffer_high = 4096;
- else
- 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;
-
- /* Initialize Initialize buffers. */
- buffer_init(&stdin_buffer);
- buffer_init(&stdout_buffer);
- buffer_init(&stderr_buffer);
-
- /* If we have no separate fderr (which is the case when we have a pty - there
- we cannot make difference between data sent to stdout and stderr),
- indicate that we have seen an EOF from stderr. This way we don\'t
- need to check the descriptor everywhere. */
- if (fderr == -1)
- fderr_eof = 1;
-
- /* Main loop of the server for the interactive session mode. */
- for (;;)
- {
- fd_set readset, writeset;
-
- /* Process buffered packets from the client. */
- process_buffered_input_packets();
-
- /* If we have received eof, and there is no more pending input data,
- cause a real eof by closing fdin. */
- if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0)
- {
+ fd_set readset, writeset;
+ int wait_status; /* Status returned by wait(). */
+ pid_t wait_pid; /* pid returned by wait(). */
+ int waiting_termination = 0; /* Have displayed waiting close message. */
+ unsigned int max_time_milliseconds;
+ unsigned int previous_stdout_buffer_bytes;
+ unsigned int stdout_buffer_bytes;
+ int type;
+
+ debug("Entering interactive session.");
+
+ /* Initialize the SIGCHLD kludge. */
+ child_pid = pid;
+ child_terminated = 0;
+ child_has_selected = 0;
+ signal(SIGCHLD, sigchld_handler);
+ signal(SIGPIPE, SIG_IGN);
+
+ /* Initialize our global variables. */
+ fdin = fdin_arg;
+ fdout = fdout_arg;
+ fderr = fderr_arg;
+
+ /* nonblocking IO */
+ set_nonblock(fdin);
+ set_nonblock(fdout);
+ /* we don't have stderr for interactive terminal sessions, see below */
+ if (fderr != -1)
+ set_nonblock(fderr);
+
+ connection_in = packet_get_connection_in();
+ connection_out = packet_get_connection_out();
+
+ previous_stdout_buffer_bytes = 0;
+
+ /* Set approximate I/O buffer size. */
+ if (packet_is_interactive())
+ buffer_high = 4096;
+ else
+ 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;
+
+ /* Initialize Initialize buffers. */
+ buffer_init(&stdin_buffer);
+ buffer_init(&stdout_buffer);
+ buffer_init(&stderr_buffer);
+
+ /*
+ * If we have no separate fderr (which is the case when we have a pty
+ * - there we cannot make difference between data sent to stdout and
+ * stderr), indicate that we have seen an EOF from stderr. This way
+ * we don\'t need to check the descriptor everywhere.
+ */
+ if (fderr == -1)
+ fderr_eof = 1;
+
+ server_init_dispatch();
+
+ /* Main loop of the server for the interactive session mode. */
+ for (;;) {
+
+ /* Process buffered packets from the client. */
+ process_buffered_input_packets();
+
+ /*
+ * If we have received eof, and there is no more pending
+ * input data, cause a real eof by closing fdin.
+ */
+ if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
#ifdef USE_PIPES
- close(fdin);
+ close(fdin);
#else
- if (fdout == -1)
- close(fdin);
- else
- shutdown(fdin, SHUT_WR); /* We will no longer send. */
+ if (fdin != fdout)
+ close(fdin);
+ else
+ shutdown(fdin, SHUT_WR); /* We will no longer send. */
#endif
- fdin = -1;
+ fdin = -1;
+ }
+ /* Make packets from buffered stderr data to send to the client. */
+ make_packets_from_stderr_data();
+
+ /*
+ * Make packets from buffered stdout data to send to the
+ * client. If there is very little to send, this arranges to
+ * not send them now, but to wait a short while to see if we
+ * are getting more data. This is necessary, as some systems
+ * wake up readers from a pty after each separate character.
+ */
+ max_time_milliseconds = 0;
+ stdout_buffer_bytes = buffer_len(&stdout_buffer);
+ if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
+ stdout_buffer_bytes != previous_stdout_buffer_bytes) {
+ /* try again after a while */
+ max_time_milliseconds = 10;
+ } else {
+ /* Send it now. */
+ make_packets_from_stdout_data();
+ }
+ previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
+
+ /* Send channel data to the client. */
+ if (packet_not_very_much_data_to_write())
+ channel_output_poll();
+
+ /*
+ * Bail out of the loop if the program has closed its output
+ * descriptors, and we have no more data to send to the
+ * client, and there is no pending buffered data.
+ */
+ if (((fdout_eof && fderr_eof) ||
+ (child_terminated && child_has_selected)) &&
+ !packet_have_data_to_write() &&
+ (buffer_len(&stdout_buffer) == 0) &&
+ (buffer_len(&stderr_buffer) == 0)) {
+ if (!channel_still_open())
+ break;
+ if (!waiting_termination) {
+ const char *s = "Waiting for forwarded connections to terminate...\r\n";
+ char *cp;
+ waiting_termination = 1;
+ buffer_append(&stderr_buffer, s, strlen(s));
+
+ /* Display list of open channels. */
+ cp = channel_open_message();
+ buffer_append(&stderr_buffer, cp, strlen(cp));
+ xfree(cp);
+ }
+ }
+ /* Sleep in select() until we can do something. */
+ wait_until_can_do_something(&readset, &writeset,
+ max_time_milliseconds);
+
+ /* Process any channel events. */
+ channel_after_select(&readset, &writeset);
+
+ /* Process input from the client and from program stdout/stderr. */
+ process_input(&readset);
+
+ /* Process output to the client and to program stdin. */
+ process_output(&writeset);
+ }
+
+ /* Cleanup and termination code. */
+
+ /* Wait until all output has been sent to the client. */
+ drain_output();
+
+ debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
+ stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
+
+ /* Free and clear the buffers. */
+ buffer_free(&stdin_buffer);
+ buffer_free(&stdout_buffer);
+ buffer_free(&stderr_buffer);
+
+ /* Close the file descriptors. */
+ if (fdout != -1)
+ close(fdout);
+ fdout = -1;
+ fdout_eof = 1;
+ if (fderr != -1)
+ close(fderr);
+ fderr = -1;
+ fderr_eof = 1;
+ if (fdin != -1)
+ close(fdin);
+ fdin = -1;
+
+ /* Stop listening for channels; this removes unix domain sockets. */
+ channel_stop_listening();
+
+ /* Wait for the child to exit. Get its exit status. */
+ wait_pid = wait(&wait_status);
+ if (wait_pid < 0) {
+ /*
+ * It is possible that the wait was handled by SIGCHLD
+ * handler. This may result in either: this call
+ * returning with EINTR, or: this call returning ECHILD.
+ */
+ if (child_terminated)
+ wait_status = child_wait_status;
+ else
+ packet_disconnect("wait: %.100s", strerror(errno));
+ } else {
+ /* Check if it matches the process we forked. */
+ if (wait_pid != pid)
+ error("Strange, wait returned pid %d, expected %d",
+ wait_pid, pid);
}
- /* Make packets from buffered stderr data to send to the client. */
- make_packets_from_stderr_data();
-
- /* Make packets from buffered stdout data to send to the client.
- If there is very little to send, this arranges to not send them
- now, but to wait a short while to see if we are getting more data.
- This is necessary, as some systems wake up readers from a pty after
- each separate character. */
- max_time_milliseconds = 0;
- stdout_buffer_bytes = buffer_len(&stdout_buffer);
- if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
- stdout_buffer_bytes != previous_stdout_buffer_bytes)
- max_time_milliseconds = 10; /* try again after a while */
- else
- make_packets_from_stdout_data(); /* Send it now. */
- previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
-
- /* Send channel data to the client. */
- if (packet_not_very_much_data_to_write())
- channel_output_poll();
-
- /* Bail out of the loop if the program has closed its output descriptors,
- and we have no more data to send to the client, and there is no
- pending buffered data. */
- if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
- buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0)
- {
- if (!channel_still_open())
- goto quit;
- if (!waiting_termination)
- {
- const char *s =
- "Waiting for forwarded connections to terminate...\r\n";
- char *cp;
- waiting_termination = 1;
- buffer_append(&stderr_buffer, s, strlen(s));
-
- /* Display list of open channels. */
- cp = channel_open_message();
- buffer_append(&stderr_buffer, cp, strlen(cp));
- xfree(cp);
- }
+ /* We no longer want our SIGCHLD handler to be called. */
+ signal(SIGCHLD, SIG_DFL);
+
+ /* Check if it exited normally. */
+ if (WIFEXITED(wait_status)) {
+ /* Yes, normal exit. Get exit status and send it to the client. */
+ debug("Command exited with status %d.", WEXITSTATUS(wait_status));
+ packet_start(SSH_SMSG_EXITSTATUS);
+ packet_put_int(WEXITSTATUS(wait_status));
+ packet_send();
+ packet_write_wait();
+
+ /*
+ * Wait for exit confirmation. Note that there might be
+ * other packets coming before it; however, the program has
+ * already died so we just ignore them. The client is
+ * supposed to respond with the confirmation when it receives
+ * the exit status.
+ */
+ do {
+ int plen;
+ type = packet_read(&plen);
+ }
+ while (type != SSH_CMSG_EXIT_CONFIRMATION);
+
+ debug("Received exit confirmation.");
+ return;
}
+ /* Check if the program terminated due to a signal. */
+ if (WIFSIGNALED(wait_status))
+ packet_disconnect("Command terminated on signal %d.",
+ WTERMSIG(wait_status));
+
+ /* Some weird exit cause. Just exit. */
+ packet_disconnect("wait returned status %04x.", wait_status);
+ /* NOTREACHED */
+}
- /* Sleep in select() until we can do something. */
- wait_until_can_do_something(&readset, &writeset,
- max_time_milliseconds);
-
- /* Process any channel events. */
- channel_after_select(&readset, &writeset);
-
- /* Process input from the client and from program stdout/stderr. */
- process_input(&readset);
-
- /* Process output to the client and to program stdin. */
- process_output(&writeset);
- }
-
- quit:
- /* Cleanup and termination code. */
-
- /* Wait until all output has been sent to the client. */
- drain_output();
-
- debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
- stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
-
- /* Free and clear the buffers. */
- buffer_free(&stdin_buffer);
- buffer_free(&stdout_buffer);
- buffer_free(&stderr_buffer);
-
- /* Close the file descriptors. */
- if (fdout != -1)
- close(fdout);
- fdout = -1;
- fdout_eof = 1;
- if (fderr != -1)
- close(fderr);
- fderr = -1;
- fderr_eof = 1;
- if (fdin != -1)
- close(fdin);
- fdin = -1;
-
- /* Stop listening for channels; this removes unix domain sockets. */
- channel_stop_listening();
-
- /* Wait for the child to exit. Get its exit status. */
- wait_pid = wait(&wait_status);
- if (wait_pid < 0)
- {
- /* It is possible that the wait was handled by SIGCHLD handler. This
- may result in either: this call returning with EINTR, or: this
- call returning ECHILD. */
- if (child_terminated)
- wait_status = child_wait_status;
- else
- packet_disconnect("wait: %.100s", strerror(errno));
- }
- else
- {
- /* Check if it matches the process we forked. */
- if (wait_pid != pid)
- error("Strange, wait returned pid %d, expected %d", wait_pid, pid);
- }
-
- /* We no longer want our SIGCHLD handler to be called. */
- signal(SIGCHLD, SIG_DFL);
-
- /* Check if it exited normally. */
- if (WIFEXITED(wait_status))
- {
- /* Yes, normal exit. Get exit status and send it to the client. */
- debug("Command exited with status %d.", WEXITSTATUS(wait_status));
- packet_start(SSH_SMSG_EXITSTATUS);
- packet_put_int(WEXITSTATUS(wait_status));
- packet_send();
- packet_write_wait();
-
- /* Wait for exit confirmation. Note that there might be other
- packets coming before it; however, the program has already died
- so we just ignore them. The client is supposed to respond with
- the confirmation when it receives the exit status. */
- do
- {
- int plen;
- type = packet_read(&plen);
+void
+server_loop2(void)
+{
+ fd_set readset, writeset;
+ int had_channel = 0;
+ int status;
+ pid_t pid;
+
+ debug("Entering interactive session for SSH2.");
+
+ signal(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;
+ server_init_dispatch();
+
+ for (;;) {
+ process_buffered_input_packets();
+ if (!had_channel && channel_still_open())
+ had_channel = 1;
+ if (had_channel && !channel_still_open()) {
+ debug("!channel_still_open.");
+ break;
+ }
+ if (packet_not_very_much_data_to_write())
+ channel_output_poll();
+ wait_until_can_do_something(&readset, &writeset, 0);
+ if (child_terminated && child_has_selected) {
+ /* XXX: race - assumes only one child has terminated */
+ while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
+ session_close_by_pid(pid, status);
+ child_terminated = 0;
+ child_has_selected = 0;
+ signal(SIGCHLD, sigchld_handler2);
+ }
+ channel_after_select(&readset, &writeset);
+ process_input(&readset);
+ process_output(&writeset);
}
- while (type != SSH_CMSG_EXIT_CONFIRMATION);
+ signal(SIGCHLD, SIG_DFL);
+ while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
+ session_close_by_pid(pid, status);
+ channel_stop_listening();
+}
+
+void
+server_input_stdin_data(int type, int plen, void *ctxt)
+{
+ char *data;
+ unsigned int data_len;
+
+ /* Stdin data from the client. Append it to the buffer. */
+ /* Ignore any data if the client has closed stdin. */
+ if (fdin == -1)
+ return;
+ data = packet_get_string(&data_len);
+ packet_integrity_check(plen, (4 + data_len), type);
+ buffer_append(&stdin_buffer, data, data_len);
+ memset(data, 0, data_len);
+ xfree(data);
+}
- debug("Received exit confirmation.");
- return;
- }
+void
+server_input_eof(int type, int plen, void *ctxt)
+{
+ /*
+ * Eof from the client. The stdin descriptor to the
+ * program will be closed when all buffered data has
+ * drained.
+ */
+ debug("EOF received for stdin.");
+ packet_integrity_check(plen, 0, type);
+ stdin_eof = 1;
+}
+
+void
+server_input_window_size(int type, int plen, void *ctxt)
+{
+ int row = packet_get_int();
+ int col = packet_get_int();
+ int xpixel = packet_get_int();
+ int ypixel = packet_get_int();
+
+ debug("Window change received.");
+ packet_integrity_check(plen, 4 * 4, type);
+ if (fdin != -1)
+ pty_change_window_size(fdin, row, col, xpixel, ypixel);
+}
- /* Check if the program terminated due to a signal. */
- if (WIFSIGNALED(wait_status))
- packet_disconnect("Command terminated on signal %d.",
- WTERMSIG(wait_status));
+int
+input_direct_tcpip(void)
+{
+ int sock;
+ char *target, *originator;
+ int target_port, originator_port;
+
+ target = packet_get_string(NULL);
+ target_port = packet_get_int();
+ originator = packet_get_string(NULL);
+ originator_port = packet_get_int();
+ packet_done();
+
+ debug("open direct-tcpip: from %s port %d to %s port %d",
+ originator, originator_port, target, target_port);
+
+ /* XXX check permission */
+ if (no_port_forwarding_flag || !options.allow_tcp_forwarding) {
+ xfree(target);
+ xfree(originator);
+ return -1;
+ }
+ sock = channel_connect_to(target, target_port);
+ xfree(target);
+ xfree(originator);
+ if (sock < 0)
+ return -1;
+ return channel_new("direct-tcpip", SSH_CHANNEL_OPEN,
+ sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
+ CHAN_TCP_PACKET_DEFAULT, 0, xstrdup("direct-tcpip"), 1);
+}
- /* Some weird exit cause. Just exit. */
- packet_disconnect("wait returned status %04x.", wait_status);
- /*NOTREACHED*/
+void
+server_input_channel_open(int type, int plen, void *ctxt)
+{
+ Channel *c = NULL;
+ char *ctype;
+ int id;
+ unsigned int len;
+ int rchan;
+ int rmaxpack;
+ int rwindow;
+
+ ctype = packet_get_string(&len);
+ rchan = packet_get_int();
+ rwindow = packet_get_int();
+ rmaxpack = packet_get_int();
+
+ debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
+ ctype, rchan, rwindow, rmaxpack);
+
+ if (strcmp(ctype, "session") == 0) {
+ debug("open session");
+ packet_done();
+ /*
+ * A server session has no fd to read or write
+ * until a CHANNEL_REQUEST for a shell is made,
+ * so we set the type to SSH_CHANNEL_LARVAL.
+ * Additionally, a callback for handling all
+ * CHANNEL_REQUEST messages is registered.
+ */
+ id = channel_new(ctype, SSH_CHANNEL_LARVAL,
+ -1, -1, -1, 0, CHAN_SES_PACKET_DEFAULT,
+ 0, xstrdup("server-session"), 1);
+ if (session_open(id) == 1) {
+ channel_register_callback(id, SSH2_MSG_CHANNEL_REQUEST,
+ session_input_channel_req, (void *)0);
+ channel_register_cleanup(id, session_close_by_channel);
+ c = channel_lookup(id);
+ } else {
+ debug("session open failed, free channel %d", id);
+ channel_free(id);
+ }
+ } else if (strcmp(ctype, "direct-tcpip") == 0) {
+ id = input_direct_tcpip();
+ if (id >= 0)
+ c = channel_lookup(id);
+ }
+ if (c != NULL) {
+ debug("confirm %s", ctype);
+ c->remote_id = rchan;
+ c->remote_window = rwindow;
+ c->remote_maxpacket = rmaxpack;
+
+ packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
+ packet_put_int(c->remote_id);
+ packet_put_int(c->self);
+ packet_put_int(c->local_window);
+ packet_put_int(c->local_maxpacket);
+ packet_send();
+ } else {
+ debug("failure %s", ctype);
+ packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(rchan);
+ packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
+ packet_put_cstring("bla bla");
+ packet_put_cstring("");
+ packet_send();
+ }
+ xfree(ctype);
}
+void
+server_init_dispatch_20()
+{
+ debug("server_init_dispatch_20");
+ dispatch_init(&dispatch_protocol_error);
+ dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
+ dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
+ dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
+ dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
+ dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
+ dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
+ dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
+ dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &channel_input_channel_request);
+ dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
+}
+void
+server_init_dispatch_13()
+{
+ debug("server_init_dispatch_13");
+ dispatch_init(NULL);
+ dispatch_set(SSH_CMSG_EOF, &server_input_eof);
+ dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
+ dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
+ dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
+ dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
+ dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
+ dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
+}
+void
+server_init_dispatch_15()
+{
+ server_init_dispatch_13();
+ debug("server_init_dispatch_15");
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
+}
+void
+server_init_dispatch()
+{
+ if (compat20)
+ server_init_dispatch_20();
+ else if (compat13)
+ server_init_dispatch_13();
+ else
+ server_init_dispatch_15();
+}
andersk / openssh.git / blobdiff