* 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 1.56 2001/04/04 14:34:58 markus 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"
+#include "kex.h"
+
+extern ServerOptions options;
+
+/* XXX */
+extern Kex *xxx_kex;
static Buffer stdin_buffer; /* Buffer for stdin data. */
static Buffer stdout_buffer; /* Buffer for stdout data. */
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 unsigned int buffer_high;/* "Soft" max buffer size. */
-static int max_fd; /* Max file descriptor number for select(). */
+static u_int buffer_high;/* "Soft" max buffer size. */
/*
* 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 server_init_dispatch(void);
if (WIFEXITED(child_wait_status) ||
WIFSIGNALED(child_wait_status))
child_terminated = 1;
- child_has_selected = 0;
}
signal(SIGCHLD, sigchld_handler);
errno = save_errno;
int save_errno = errno;
debug("Received SIGCHLD.");
child_terminated = 1;
- child_has_selected = 0;
+ mysignal(SIGCHLD, sigchld_handler2);
errno = save_errno;
}
* to the client.
*/
void
-make_packets_from_stderr_data()
+make_packets_from_stderr_data(void)
{
int len;
* client.
*/
void
-make_packets_from_stdout_data()
+make_packets_from_stdout_data(void)
{
int len;
} 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);
* 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)
+wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
+ u_int max_time_milliseconds)
{
struct timeval tv, *tvp;
int ret;
/* 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
*/
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
tvp = &tv;
}
if (tvp!=NULL)
- debug("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)
else
goto retry_select;
}
-
- if (child_terminated)
- child_has_selected = 1;
}
/*
void
process_output(fd_set * writeset)
{
+ struct termios tio;
int len;
/* Write buffered data to program stdin. */
#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;
* 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) {
}
void
-process_buffered_input_packets()
+process_buffered_input_packets(void)
{
- dispatch_run(DISPATCH_NONBLOCK, NULL, NULL);
+ dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
}
/*
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. */
- unsigned int max_time_milliseconds;
- unsigned int previous_stdout_buffer_bytes;
- unsigned int stdout_buffer_bytes;
+ u_int max_time_milliseconds;
+ u_int previous_stdout_buffer_bytes;
+ u_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);
/* Initialize our global variables. */
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();
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);
* 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 (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
+ buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
if (!channel_still_open())
break;
if (!waiting_termination) {
}
}
/* 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. */
/* Wait for the child to exit. Get its exit status. */
wait_pid = wait(&wait_status);
- if (wait_pid < 0) {
+ if (wait_pid == -1) {
/*
* It is possible that the wait was handled by SIGCHLD
* handler. This may result in either: this call
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);
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 (;;) {
}
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;
- signal(SIGCHLD, sigchld_handler2);
}
- channel_after_select(&readset, &writeset);
- if (child_terminated && child_has_selected)
- break;
- 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);
server_input_stdin_data(int type, int plen, void *ctxt)
{
char *data;
- unsigned int data_len;
+ u_int data_len;
/* Stdin data from the client. Append it to the buffer. */
/* Ignore any data if the client has closed stdin. */
pty_change_window_size(fdin, row, col, xpixel, ypixel);
}
-int
-input_direct_tcpip(void)
+Channel *
+server_request_direct_tcpip(char *ctype)
{
- int sock;
+ int sock, newch;
char *target, *originator;
int target_port, originator_port;
originator_port = packet_get_int();
packet_done();
- debug("open direct-tcpip: from %s port %d to %s port %d",
+ debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
originator, originator_port, target, target_port);
/* XXX check permission */
- if (no_port_forwarding_flag) {
- 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,
+ return NULL;
+ newch = channel_new(ctype, SSH_CHANNEL_CONNECTING,
sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
- CHAN_TCP_PACKET_DEFAULT, 0, xstrdup("direct-tcpip"));
+ CHAN_TCP_PACKET_DEFAULT, 0, xstrdup("direct-tcpip"), 1);
+ return (newch >= 0) ? channel_lookup(newch) : NULL;
+}
+
+Channel *
+server_request_session(char *ctype)
+{
+ int newch;
+
+ debug("input_session_request");
+ 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.
+ */
+ newch = channel_new(ctype, SSH_CHANNEL_LARVAL,
+ -1, -1, -1, 0, CHAN_SES_PACKET_DEFAULT,
+ 0, xstrdup("server-session"), 1);
+ if (session_open(newch) == 1) {
+ channel_register_callback(newch, SSH2_MSG_CHANNEL_REQUEST,
+ session_input_channel_req, (void *)0);
+ channel_register_cleanup(newch, session_close_by_channel);
+ return channel_lookup(newch);
+ } else {
+ debug("session open failed, free channel %d", newch);
+ channel_free(newch);
+ }
+ return NULL;
}
void
{
Channel *c = NULL;
char *ctype;
- int id;
- unsigned int len;
+ u_int len;
int rchan;
int rmaxpack;
int rwindow;
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"));
- 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);
- }
+ c = server_request_session(ctype);
} else if (strcmp(ctype, "direct-tcpip") == 0) {
- id = input_direct_tcpip();
- if (id >= 0)
- c = channel_lookup(id);
+ c = server_request_direct_tcpip(ctype);
}
if (c != NULL) {
- debug("confirm %s", ctype);
+ debug("server_input_channel_open: confirm %s", ctype);
c->remote_id = rchan;
c->remote_window = rwindow;
c->remote_maxpacket = rmaxpack;
packet_put_int(c->local_maxpacket);
packet_send();
} else {
- debug("failure %s", ctype);
+ debug("server_input_channel_open: failure %s", ctype);
packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
packet_put_int(rchan);
packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
}
void
-server_init_dispatch_20()
+server_input_global_request(int type, int plen, void *ctxt)
+{
+ char *rtype;
+ int want_reply;
+ int success = 0;
+
+ rtype = packet_get_string(NULL);
+ want_reply = packet_get_char();
+ debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
+
+ /* -R style forwarding */
+ if (strcmp(rtype, "tcpip-forward") == 0) {
+ struct passwd *pw;
+ char *listen_address;
+ u_short listen_port;
+
+ pw = auth_get_user();
+ if (pw == NULL)
+ fatal("server_input_global_request: no user");
+ listen_address = packet_get_string(NULL); /* XXX currently ignored */
+ listen_port = (u_short)packet_get_int();
+ debug("server_input_global_request: tcpip-forward listen %s port %d",
+ listen_address, listen_port);
+
+ /* check permissions */
+ if (!options.allow_tcp_forwarding ||
+ no_port_forwarding_flag ||
+ (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)) {
+ success = 0;
+ packet_send_debug("Server has disabled port forwarding.");
+ } else {
+ /* Start listening on the port */
+ success = channel_request_forwarding(
+ listen_address, listen_port,
+ /*unspec host_to_connect*/ "<unspec host>",
+ /*unspec port_to_connect*/ 0,
+ options.gateway_ports, /*remote*/ 1);
+ }
+ xfree(listen_address);
+ }
+ if (want_reply) {
+ packet_start(success ?
+ SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
+ packet_send();
+ packet_write_wait();
+ }
+ xfree(rtype);
+}
+
+void
+server_init_dispatch_20(void)
{
debug("server_init_dispatch_20");
dispatch_init(&dispatch_protocol_error);
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);
+ dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
+
+ /* rekeying */
+ dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
}
void
-server_init_dispatch_13()
+server_init_dispatch_13(void)
{
debug("server_init_dispatch_13");
dispatch_init(NULL);
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");
dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
}
void
-server_init_dispatch()
+server_init_dispatch(void)
{
if (compat20)
server_init_dispatch_20();
andersk / openssh.git / blobdiff