* 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, 2001 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 1.67 2001/05/31 10:30:16 markus Exp $");
+RCSID("$OpenBSD: serverloop.c,v 1.88 2001/12/20 22:50:24 djm Exp $");
#include "xmalloc.h"
#include "packet.h"
/* XXX */
extern Kex *xxx_kex;
+static Authctxt *xxx_authctxt;
static Buffer stdin_buffer; /* Buffer for stdin data. */
static Buffer stdout_buffer; /* Buffer for stdout data. */
static int connection_out; /* Connection to client (output). */
static int connection_closed = 0; /* Connection to client closed. */
static u_int buffer_high; /* "Soft" max buffer size. */
+static int client_alive_timeouts = 0;
/*
* 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 pid_t child_pid; /* Pid of the child. */
-static volatile int child_terminated; /* The child has terminated. */
-static volatile int child_wait_status; /* Status from wait(). */
+static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
-void server_init_dispatch(void);
+/* prototypes */
+static void server_init_dispatch(void);
-int client_alive_timeouts = 0;
-
-void
-sigchld_handler(int sig)
+/*
+ * we write to this pipe if a SIGCHLD is caught in order to avoid
+ * the race between select() and child_terminated
+ */
+static int notify_pipe[2];
+static void
+notify_setup(void)
{
- 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;
+ if (pipe(notify_pipe) < 0) {
+ error("pipe(notify_pipe) failed %s", strerror(errno));
+ } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) ||
+ (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) {
+ error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
+ close(notify_pipe[0]);
+ close(notify_pipe[1]);
+ } else {
+ set_nonblock(notify_pipe[0]);
+ set_nonblock(notify_pipe[1]);
+ return;
}
- signal(SIGCHLD, sigchld_handler);
- errno = save_errno;
+ notify_pipe[0] = -1; /* read end */
+ notify_pipe[1] = -1; /* write end */
}
-void
-sigchld_handler2(int sig)
+static void
+notify_parent(void)
+{
+ if (notify_pipe[1] != -1)
+ write(notify_pipe[1], "", 1);
+}
+static void
+notify_prepare(fd_set *readset)
+{
+ if (notify_pipe[0] != -1)
+ FD_SET(notify_pipe[0], readset);
+}
+static void
+notify_done(fd_set *readset)
+{
+ char c;
+
+ if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
+ while (read(notify_pipe[0], &c, 1) != -1)
+ debug2("notify_done: reading");
+}
+
+static void
+sigchld_handler(int sig)
{
int save_errno = errno;
debug("Received SIGCHLD.");
child_terminated = 1;
- mysignal(SIGCHLD, sigchld_handler2);
+ mysignal(SIGCHLD, sigchld_handler);
+ notify_parent();
errno = save_errno;
}
* Make packets from buffered stderr data, and buffer it for sending
* to the client.
*/
-void
+static void
make_packets_from_stderr_data(void)
{
int len;
* Make packets from buffered stdout data, and buffer it for sending to the
* client.
*/
-void
+static void
make_packets_from_stdout_data(void)
{
int len;
}
}
+static void
+client_alive_check(void)
+{
+ int id;
+
+ /* timeout, check to see how many we have had */
+ if (++client_alive_timeouts > options.client_alive_count_max)
+ packet_disconnect("Timeout, your session not responding.");
+
+ id = channel_find_open();
+ if (id == -1)
+ packet_disconnect("No open channels after timeout!");
+ /*
+ * send a bogus channel request with "wantreply",
+ * we should get back a failure
+ */
+ channel_request_start(id, "keepalive@openssh.com", 1);
+ packet_send();
+}
+
/*
* 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
+static void
wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
- u_int max_time_milliseconds)
+ int *nallocp, u_int max_time_milliseconds)
{
struct timeval tv, *tvp;
int ret;
int client_alive_scheduled = 0;
/*
- * if using client_alive, set the max timeout accordingly,
+ * if using client_alive, set the max timeout accordingly,
* and indicate that this particular timeout was for client
* alive by setting the client_alive_scheduled flag.
*
* this could be randomized somewhat to make traffic
- * analysis more difficult, but we're not doing it yet.
+ * analysis more difficult, but we're not doing it yet.
*/
- if (max_time_milliseconds == 0 && options.client_alive_interval) {
+ if (compat20 &&
+ max_time_milliseconds == 0 && options.client_alive_interval) {
client_alive_scheduled = 1;
max_time_milliseconds = options.client_alive_interval * 1000;
- } else
- client_alive_scheduled = 0;
-
- /* When select fails we restart from here. */
-retry_select:
+ }
/* Allocate and update select() masks for channel descriptors. */
- channel_prepare_select(readsetp, writesetp, maxfdp, 0);
+ channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0);
if (compat20) {
+#if 0
/* wrong: bad condition XXX */
if (channel_not_very_much_buffered_data())
- FD_SET(connection_in, *readsetp);
+#endif
+ FD_SET(connection_in, *readsetp);
} else {
/*
* Read packets from the client unless we have too much
if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
FD_SET(fdin, *writesetp);
}
+ notify_prepare(*readsetp);
/*
* If we have buffered packet data going to the client, mark that
tvp = &tv;
}
if (tvp!=NULL)
- debug3("tvp!=NULL kid %d mili %d", child_terminated, max_time_milliseconds);
+ debug3("tvp!=NULL kid %d mili %d", (int) child_terminated,
+ max_time_milliseconds);
/* Wait for something to happen, or the timeout to expire. */
ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
if (ret == -1) {
+ memset(*readsetp, 0, *nallocp);
+ memset(*writesetp, 0, *nallocp);
if (errno != EINTR)
error("select: %.100s", strerror(errno));
- else
- goto retry_select;
- }
- if (ret == 0 && client_alive_scheduled) {
- /* timeout, check to see how many we have had */
- client_alive_timeouts++;
+ } else if (ret == 0 && client_alive_scheduled)
+ client_alive_check();
- if (client_alive_timeouts > options.client_alive_count_max ) {
- packet_disconnect(
- "Timeout, your session not responding.");
- } else {
- /*
- * send a bogus channel request with "wantreply"
- * we should get back a failure
- */
- int id;
-
- id = channel_find_open();
- if (id != -1) {
- channel_request_start(id,
- "keepalive@openssh.com", 1);
- packet_send();
- } else
- packet_disconnect(
- "No open channels after timeout!");
- }
- }
+ notify_done(*readsetp);
}
/*
* Processes input from the client and the program. Input data is stored
* in buffers and processed later.
*/
-void
+static void
process_input(fd_set * readset)
{
int len;
/*
* Sends data from internal buffers to client program stdin.
*/
-void
+static void
process_output(fd_set * writeset)
{
struct termios tio;
+ u_char *data;
+ u_int dlen;
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));
+ data = buffer_ptr(&stdin_buffer);
+ dlen = buffer_len(&stdin_buffer);
+ len = write(fdin, data, dlen);
if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
/* do nothing */
} else if (len <= 0) {
fdin = -1;
} else {
/* Successful write. */
- if (fdin_is_tty && tcgetattr(fdin, &tio) == 0 &&
+ if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
+ tcgetattr(fdin, &tio) == 0 &&
!(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
/*
* Simulate echo to reduce the impact of
* Wait until all buffered output has been sent to the client.
* This is used when the program terminates.
*/
-void
+static void
drain_output(void)
{
/* Send any buffered stdout data to the client. */
packet_write_wait();
}
-void
+static void
process_buffered_input_packets(void)
{
dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL);
server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
{
fd_set *readset = NULL, *writeset = NULL;
- int max_fd;
+ int max_fd = 0, nalloc = 0;
int wait_status; /* Status returned by wait(). */
pid_t wait_pid; /* pid returned by wait(). */
int waiting_termination = 0; /* Have displayed waiting close message. */
debug("Entering interactive session.");
/* Initialize the SIGCHLD kludge. */
- child_pid = pid;
child_terminated = 0;
- signal(SIGCHLD, sigchld_handler);
+ mysignal(SIGCHLD, sigchld_handler);
/* Initialize our global variables. */
fdin = fdin_arg;
connection_in = packet_get_connection_in();
connection_out = packet_get_connection_out();
+ notify_setup();
+
previous_stdout_buffer_bytes = 0;
/* Set approximate I/O buffer size. */
else
buffer_high = 64 * 1024;
+#if 0
/* Initialize max_fd to the maximum of the known file descriptors. */
- max_fd = MAX(fdin, fdout);
+ max_fd = MAX(connection_in, connection_out);
+ max_fd = MAX(max_fd, fdin);
+ max_fd = MAX(max_fd, fdout);
if (fderr != -1)
max_fd = MAX(max_fd, fderr);
- max_fd = MAX(max_fd, connection_in);
- max_fd = MAX(max_fd, connection_out);
+#endif
/* Initialize Initialize buffers. */
buffer_init(&stdin_buffer);
xfree(cp);
}
}
+ max_fd = MAX(connection_in, connection_out);
+ max_fd = MAX(max_fd, fdin);
+ max_fd = MAX(max_fd, fdout);
+ max_fd = MAX(max_fd, fderr);
+ max_fd = MAX(max_fd, notify_pipe[0]);
+
/* Sleep in select() until we can do something. */
wait_until_can_do_something(&readset, &writeset, &max_fd,
- max_time_milliseconds);
+ &nalloc, max_time_milliseconds);
/* Process any channel events. */
channel_after_select(readset, writeset);
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);
+ stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
/* Free and clear the buffers. */
buffer_free(&stdin_buffer);
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 == -1) {
- /*
- * 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);
- }
+ channel_free_all();
/* We no longer want our SIGCHLD handler to be called. */
- signal(SIGCHLD, SIG_DFL);
+ mysignal(SIGCHLD, SIG_DFL);
+
+ wait_pid = waitpid(-1, &wait_status, child_terminated ? WNOHANG : 0);
+ if (wait_pid == -1)
+ packet_disconnect("wait: %.100s", strerror(errno));
+ else if (wait_pid != pid)
+ error("Strange, wait returned pid %d, expected %d",
+ wait_pid, pid);
/* Check if it exited normally. */
if (WIFEXITED(wait_status)) {
/* NOTREACHED */
}
+static void
+collect_children(void)
+{
+ pid_t pid;
+ sigset_t oset, nset;
+ int status;
+
+ /* block SIGCHLD while we check for dead children */
+ sigemptyset(&nset);
+ sigaddset(&nset, SIGCHLD);
+ sigprocmask(SIG_BLOCK, &nset, &oset);
+ if (child_terminated) {
+ while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
+ session_close_by_pid(pid, status);
+ child_terminated = 0;
+ }
+ sigprocmask(SIG_SETMASK, &oset, NULL);
+}
+
void
-server_loop2(void)
+server_loop2(Authctxt *authctxt)
{
fd_set *readset = NULL, *writeset = NULL;
- int rekeying = 0, max_fd, status;
- pid_t pid;
+ int rekeying = 0, max_fd, nalloc = 0;
debug("Entering interactive session for SSH2.");
- mysignal(SIGCHLD, sigchld_handler2);
+ mysignal(SIGCHLD, sigchld_handler);
child_terminated = 0;
connection_in = packet_get_connection_in();
connection_out = packet_get_connection_out();
+ notify_setup();
+
max_fd = MAX(connection_in, connection_out);
+ max_fd = MAX(max_fd, notify_pipe[0]);
+
+ xxx_authctxt = authctxt;
server_init_dispatch();
if (!rekeying && packet_not_very_much_data_to_write())
channel_output_poll();
wait_until_can_do_something(&readset, &writeset, &max_fd,
- rekeying);
- if (child_terminated) {
- while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
- session_close_by_pid(pid, status);
- child_terminated = 0;
- }
+ &nalloc, 0);
+
+ collect_children();
if (!rekeying)
channel_after_select(readset, writeset);
process_input(readset);
break;
process_output(writeset);
}
+ collect_children();
+
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);
- channel_stop_listening();
+ /* free all channels, no more reads and writes */
+ channel_free_all();
+
+ /* free remaining sessions, e.g. remove wtmp entries */
+ session_destroy_all();
}
-void
-server_input_channel_failure(int type, int plen, void *ctxt)
+static void
+server_input_channel_failure(int type, int plen, u_int32_t seq, void *ctxt)
{
debug("Got CHANNEL_FAILURE for keepalive");
- /*
+ /*
* reset timeout, since we got a sane answer from the client.
* even if this was generated by something other than
* the bogus CHANNEL_REQUEST we send for keepalives.
*/
- client_alive_timeouts = 0;
+ client_alive_timeouts = 0;
}
-void
-server_input_stdin_data(int type, int plen, void *ctxt)
+static void
+server_input_stdin_data(int type, int plen, u_int32_t seq, void *ctxt)
{
char *data;
u_int data_len;
xfree(data);
}
-void
-server_input_eof(int type, int plen, void *ctxt)
+static void
+server_input_eof(int type, int plen, u_int32_t seq, void *ctxt)
{
/*
* Eof from the client. The stdin descriptor to the
stdin_eof = 1;
}
-void
-server_input_window_size(int type, int plen, void *ctxt)
+static void
+server_input_window_size(int type, int plen, u_int32_t seq, void *ctxt)
{
int row = packet_get_int();
int col = packet_get_int();
pty_change_window_size(fdin, row, col, xpixel, ypixel);
}
-Channel *
+static Channel *
server_request_direct_tcpip(char *ctype)
{
Channel *c;
return c;
}
-Channel *
+static Channel *
server_request_session(char *ctype)
{
Channel *c;
error("server_request_session: channel_new failed");
return NULL;
}
- if (session_open(c->self) != 1) {
+ if (session_open(xxx_authctxt, c->self) != 1) {
debug("session open failed, free channel %d", c->self);
channel_free(c);
return NULL;
return c;
}
-void
-server_input_channel_open(int type, int plen, void *ctxt)
+static void
+server_input_channel_open(int type, int plen, u_int32_t seq, void *ctxt)
{
Channel *c = NULL;
char *ctype;
xfree(ctype);
}
-void
-server_input_global_request(int type, int plen, void *ctxt)
+static void
+server_input_global_request(int type, int plen, u_int32_t seq, void *ctxt)
{
char *rtype;
int want_reply;
xfree(rtype);
}
-void
+static void
server_init_dispatch_20(void)
{
debug("server_init_dispatch_20");
/* rekeying */
dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
}
-void
+static void
server_init_dispatch_13(void)
{
debug("server_init_dispatch_13");
dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
}
-void
+static void
server_init_dispatch_15(void)
{
server_init_dispatch_13();
dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
}
-void
+static void
server_init_dispatch(void)
{
if (compat20)
else
server_init_dispatch_15();
}
-
andersk / openssh.git / blobdiff