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putty-source/plink.c
Jacob Nevins 20f433efac Add a configuration option for TCP keepalives (SO_KEEPALIVE), default off. 
No very good reason, but I've occasionally wanted to frob it to see if it
makes any difference to problems I'm having, and it was easy.

Tested that it does actually cause keepalives on Windows (with tcpdump);
should also work on Unix. Not implemented on Mac (does nothing), but then
neither is TCP_NODELAY.

Quite a big checkin, much of which is adding `keepalive' alongside `nodelay'
in network function calls.

[originally from svn r4309]
2004-06-20 17:07:38 +00:00

781 lines
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/*
* PLink - a Windows command-line (stdin/stdout) variant of PuTTY.
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <stdarg.h>
#define PUTTY_DO_GLOBALS /* actually _define_ globals */
#include "putty.h"
#include "storage.h"
#include "tree234.h"
#define WM_AGENT_CALLBACK (WM_XUSER + 4)
#define MAX_STDIN_BACKLOG 4096
struct agent_callback {
void (*callback)(void *, void *, int);
void *callback_ctx;
void *data;
int len;
};
void fatalbox(char *p, ...)
{
va_list ap;
fprintf(stderr, "FATAL ERROR: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
cleanup_exit(1);
}
void modalfatalbox(char *p, ...)
{
va_list ap;
fprintf(stderr, "FATAL ERROR: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
cleanup_exit(1);
}
void connection_fatal(void *frontend, char *p, ...)
{
va_list ap;
fprintf(stderr, "FATAL ERROR: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
cleanup_exit(1);
}
void cmdline_error(char *p, ...)
{
va_list ap;
fprintf(stderr, "plink: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
exit(1);
}
HANDLE inhandle, outhandle, errhandle;
DWORD orig_console_mode;
WSAEVENT netevent;
static Backend *back;
static void *backhandle;
static Config cfg;
int term_ldisc(Terminal *term, int mode)
{
return FALSE;
}
void ldisc_update(void *frontend, int echo, int edit)
{
/* Update stdin read mode to reflect changes in line discipline. */
DWORD mode;
mode = ENABLE_PROCESSED_INPUT;
if (echo)
mode = mode | ENABLE_ECHO_INPUT;
else
mode = mode & ~ENABLE_ECHO_INPUT;
if (edit)
mode = mode | ENABLE_LINE_INPUT;
else
mode = mode & ~ENABLE_LINE_INPUT;
SetConsoleMode(inhandle, mode);
}
struct input_data {
DWORD len;
char buffer[4096];
HANDLE event, eventback;
};
static DWORD WINAPI stdin_read_thread(void *param)
{
struct input_data *idata = (struct input_data *) param;
HANDLE inhandle;
inhandle = GetStdHandle(STD_INPUT_HANDLE);
while (ReadFile(inhandle, idata->buffer, sizeof(idata->buffer),
&idata->len, NULL) && idata->len > 0) {
SetEvent(idata->event);
WaitForSingleObject(idata->eventback, INFINITE);
}
idata->len = 0;
SetEvent(idata->event);
return 0;
}
struct output_data {
DWORD len, lenwritten;
int writeret;
char *buffer;
int is_stderr, done;
HANDLE event, eventback;
int busy;
};
static DWORD WINAPI stdout_write_thread(void *param)
{
struct output_data *odata = (struct output_data *) param;
HANDLE outhandle, errhandle;
outhandle = GetStdHandle(STD_OUTPUT_HANDLE);
errhandle = GetStdHandle(STD_ERROR_HANDLE);
while (1) {
WaitForSingleObject(odata->eventback, INFINITE);
if (odata->done)
break;
odata->writeret =
WriteFile(odata->is_stderr ? errhandle : outhandle,
odata->buffer, odata->len, &odata->lenwritten, NULL);
SetEvent(odata->event);
}
return 0;
}
bufchain stdout_data, stderr_data;
struct output_data odata, edata;
void try_output(int is_stderr)
{
struct output_data *data = (is_stderr ? &edata : &odata);
void *senddata;
int sendlen;
if (!data->busy) {
bufchain_prefix(is_stderr ? &stderr_data : &stdout_data,
&senddata, &sendlen);
data->buffer = senddata;
data->len = sendlen;
SetEvent(data->eventback);
data->busy = 1;
}
}
int from_backend(void *frontend_handle, int is_stderr,
const char *data, int len)
{
int osize, esize;
if (is_stderr) {
bufchain_add(&stderr_data, data, len);
try_output(1);
} else {
bufchain_add(&stdout_data, data, len);
try_output(0);
}
osize = bufchain_size(&stdout_data);
esize = bufchain_size(&stderr_data);
return osize + esize;
}
static DWORD main_thread_id;
void agent_schedule_callback(void (*callback)(void *, void *, int),
void *callback_ctx, void *data, int len)
{
struct agent_callback *c = snew(struct agent_callback);
c->callback = callback;
c->callback_ctx = callback_ctx;
c->data = data;
c->len = len;
PostThreadMessage(main_thread_id, WM_AGENT_CALLBACK, 0, (LPARAM)c);
}
/*
* Short description of parameters.
*/
static void usage(void)
{
printf("PuTTY Link: command-line connection utility\n");
printf("%s\n", ver);
printf("Usage: plink [options] [user@]host [command]\n");
printf(" (\"host\" can also be a PuTTY saved session name)\n");
printf("Options:\n");
printf(" -V print version information\n");
printf(" -v show verbose messages\n");
printf(" -load sessname Load settings from saved session\n");
printf(" -ssh -telnet -rlogin -raw\n");
printf(" force use of a particular protocol (default SSH)\n");
printf(" -P port connect to specified port\n");
printf(" -l user connect with specified username\n");
printf(" -m file read remote command(s) from file\n");
printf(" -batch disable all interactive prompts\n");
printf("The following options only apply to SSH connections:\n");
printf(" -pw passw login with specified password\n");
printf(" -D [listen-IP:]listen-port\n");
printf(" Dynamic SOCKS-based port forwarding\n");
printf(" -L [listen-IP:]listen-port:host:port\n");
printf(" Forward local port to remote address\n");
printf(" -R [listen-IP:]listen-port:host:port\n");
printf(" Forward remote port to local address\n");
printf(" -X -x enable / disable X11 forwarding\n");
printf(" -A -a enable / disable agent forwarding\n");
printf(" -t -T enable / disable pty allocation\n");
printf(" -1 -2 force use of particular protocol version\n");
printf(" -C enable compression\n");
printf(" -i key private key file for authentication\n");
printf(" -s remote command is an SSH subsystem (SSH-2 only)\n");
exit(1);
}
static void version(void)
{
printf("plink: %s\n", ver);
exit(1);
}
char *do_select(SOCKET skt, int startup)
{
int events;
if (startup) {
events = (FD_CONNECT | FD_READ | FD_WRITE |
FD_OOB | FD_CLOSE | FD_ACCEPT);
} else {
events = 0;
}
if (p_WSAEventSelect(skt, netevent, events) == SOCKET_ERROR) {
switch (p_WSAGetLastError()) {
case WSAENETDOWN:
return "Network is down";
default:
return "WSAEventSelect(): unknown error";
}
}
return NULL;
}
int main(int argc, char **argv)
{
WSAEVENT stdinevent, stdoutevent, stderrevent;
HANDLE handles[4];
DWORD in_threadid, out_threadid, err_threadid;
struct input_data idata;
int reading;
int sending;
int portnumber = -1;
SOCKET *sklist;
int skcount, sksize;
int connopen;
int exitcode;
int errors;
int use_subsystem = 0;
ssh_get_line = console_get_line;
sklist = NULL;
skcount = sksize = 0;
/*
* Initialise port and protocol to sensible defaults. (These
* will be overridden by more or less anything.)
*/
default_protocol = PROT_SSH;
default_port = 22;
flags = FLAG_STDERR;
/*
* Process the command line.
*/
do_defaults(NULL, &cfg);
default_protocol = cfg.protocol;
default_port = cfg.port;
errors = 0;
{
/*
* Override the default protocol if PLINK_PROTOCOL is set.
*/
char *p = getenv("PLINK_PROTOCOL");
int i;
if (p) {
for (i = 0; backends[i].backend != NULL; i++) {
if (!strcmp(backends[i].name, p)) {
default_protocol = cfg.protocol = backends[i].protocol;
default_port = cfg.port =
backends[i].backend->default_port;
break;
}
}
}
}
while (--argc) {
char *p = *++argv;
if (*p == '-') {
int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
1, &cfg);
if (ret == -2) {
fprintf(stderr,
"plink: option \"%s\" requires an argument\n", p);
errors = 1;
} else if (ret == 2) {
--argc, ++argv;
} else if (ret == 1) {
continue;
} else if (!strcmp(p, "-batch")) {
console_batch_mode = 1;
} else if (!strcmp(p, "-s")) {
/* Save status to write to cfg later. */
use_subsystem = 1;
} else if (!strcmp(p, "-V")) {
version();
} else {
fprintf(stderr, "plink: unknown option \"%s\"\n", p);
errors = 1;
}
} else if (*p) {
if (!*cfg.host) {
char *q = p;
/*
* If the hostname starts with "telnet:", set the
* protocol to Telnet and process the string as a
* Telnet URL.
*/
if (!strncmp(q, "telnet:", 7)) {
char c;
q += 7;
if (q[0] == '/' && q[1] == '/')
q += 2;
cfg.protocol = PROT_TELNET;
p = q;
while (*p && *p != ':' && *p != '/')
p++;
c = *p;
if (*p)
*p++ = '\0';
if (c == ':')
cfg.port = atoi(p);
else
cfg.port = -1;
strncpy(cfg.host, q, sizeof(cfg.host) - 1);
cfg.host[sizeof(cfg.host) - 1] = '\0';
} else {
char *r;
/*
* Before we process the [user@]host string, we
* first check for the presence of a protocol
* prefix (a protocol name followed by ",").
*/
r = strchr(p, ',');
if (r) {
int i, j;
for (i = 0; backends[i].backend != NULL; i++) {
j = strlen(backends[i].name);
if (j == r - p &&
!memcmp(backends[i].name, p, j)) {
default_protocol = cfg.protocol =
backends[i].protocol;
portnumber =
backends[i].backend->default_port;
p = r + 1;
break;
}
}
}
/*
* Three cases. Either (a) there's a nonzero
* length string followed by an @, in which
* case that's user and the remainder is host.
* Or (b) there's only one string, not counting
* a potential initial @, and it exists in the
* saved-sessions database. Or (c) only one
* string and it _doesn't_ exist in the
* database.
*/
r = strrchr(p, '@');
if (r == p)
p++, r = NULL; /* discount initial @ */
if (r == NULL) {
/*
* One string.
*/
Config cfg2;
do_defaults(p, &cfg2);
if (cfg2.host[0] == '\0') {
/* No settings for this host; use defaults */
strncpy(cfg.host, p, sizeof(cfg.host) - 1);
cfg.host[sizeof(cfg.host) - 1] = '\0';
cfg.port = default_port;
} else {
cfg = cfg2;
cfg.remote_cmd_ptr = cfg.remote_cmd;
}
} else {
*r++ = '\0';
strncpy(cfg.username, p, sizeof(cfg.username) - 1);
cfg.username[sizeof(cfg.username) - 1] = '\0';
strncpy(cfg.host, r, sizeof(cfg.host) - 1);
cfg.host[sizeof(cfg.host) - 1] = '\0';
cfg.port = default_port;
}
}
} else {
char *command;
int cmdlen, cmdsize;
cmdlen = cmdsize = 0;
command = NULL;
while (argc) {
while (*p) {
if (cmdlen >= cmdsize) {
cmdsize = cmdlen + 512;
command = sresize(command, cmdsize, char);
}
command[cmdlen++]=*p++;
}
if (cmdlen >= cmdsize) {
cmdsize = cmdlen + 512;
command = sresize(command, cmdsize, char);
}
command[cmdlen++]=' '; /* always add trailing space */
if (--argc) p = *++argv;
}
if (cmdlen) command[--cmdlen]='\0';
/* change trailing blank to NUL */
cfg.remote_cmd_ptr = command;
cfg.remote_cmd_ptr2 = NULL;
cfg.nopty = TRUE; /* command => no terminal */
break; /* done with cmdline */
}
}
}
if (errors)
return 1;
if (!*cfg.host) {
usage();
}
/*
* Trim leading whitespace off the hostname if it's there.
*/
{
int space = strspn(cfg.host, " \t");
memmove(cfg.host, cfg.host+space, 1+strlen(cfg.host)-space);
}
/* See if host is of the form user@host */
if (cfg.host[0] != '\0') {
char *atsign = strchr(cfg.host, '@');
/* Make sure we're not overflowing the user field */
if (atsign) {
if (atsign - cfg.host < sizeof cfg.username) {
strncpy(cfg.username, cfg.host, atsign - cfg.host);
cfg.username[atsign - cfg.host] = '\0';
}
memmove(cfg.host, atsign + 1, 1 + strlen(atsign + 1));
}
}
/*
* Perform command-line overrides on session configuration.
*/
cmdline_run_saved(&cfg);
/*
* Apply subsystem status.
*/
if (use_subsystem)
cfg.ssh_subsys = TRUE;
/*
* Trim a colon suffix off the hostname if it's there.
*/
cfg.host[strcspn(cfg.host, ":")] = '\0';
/*
* Remove any remaining whitespace from the hostname.
*/
{
int p1 = 0, p2 = 0;
while (cfg.host[p2] != '\0') {
if (cfg.host[p2] != ' ' && cfg.host[p2] != '\t') {
cfg.host[p1] = cfg.host[p2];
p1++;
}
p2++;
}
cfg.host[p1] = '\0';
}
if (!*cfg.remote_cmd_ptr)
flags |= FLAG_INTERACTIVE;
/*
* Select protocol. This is farmed out into a table in a
* separate file to enable an ssh-free variant.
*/
{
int i;
back = NULL;
for (i = 0; backends[i].backend != NULL; i++)
if (backends[i].protocol == cfg.protocol) {
back = backends[i].backend;
break;
}
if (back == NULL) {
fprintf(stderr,
"Internal fault: Unsupported protocol found\n");
return 1;
}
}
/*
* Select port.
*/
if (portnumber != -1)
cfg.port = portnumber;
sk_init();
if (p_WSAEventSelect == NULL) {
fprintf(stderr, "Plink requires WinSock 2\n");
return 1;
}
/*
* Start up the connection.
*/
netevent = CreateEvent(NULL, FALSE, FALSE, NULL);
{
const char *error;
char *realhost;
/* nodelay is only useful if stdin is a character device (console) */
int nodelay = cfg.tcp_nodelay &&
(GetFileType(GetStdHandle(STD_INPUT_HANDLE)) == FILE_TYPE_CHAR);
error = back->init(NULL, &backhandle, &cfg, cfg.host, cfg.port,
&realhost, nodelay, cfg.tcp_keepalives);
if (error) {
fprintf(stderr, "Unable to open connection:\n%s", error);
return 1;
}
logctx = log_init(NULL, &cfg);
back->provide_logctx(backhandle, logctx);
console_provide_logctx(logctx);
sfree(realhost);
}
connopen = 1;
stdinevent = CreateEvent(NULL, FALSE, FALSE, NULL);
stdoutevent = CreateEvent(NULL, FALSE, FALSE, NULL);
stderrevent = CreateEvent(NULL, FALSE, FALSE, NULL);
inhandle = GetStdHandle(STD_INPUT_HANDLE);
outhandle = GetStdHandle(STD_OUTPUT_HANDLE);
errhandle = GetStdHandle(STD_ERROR_HANDLE);
GetConsoleMode(inhandle, &orig_console_mode);
SetConsoleMode(inhandle, ENABLE_PROCESSED_INPUT);
main_thread_id = GetCurrentThreadId();
/*
* Turn off ECHO and LINE input modes. We don't care if this
* call fails, because we know we aren't necessarily running in
* a console.
*/
handles[0] = netevent;
handles[1] = stdinevent;
handles[2] = stdoutevent;
handles[3] = stderrevent;
sending = FALSE;
/*
* Create spare threads to write to stdout and stderr, so we
* can arrange asynchronous writes.
*/
odata.event = stdoutevent;
odata.eventback = CreateEvent(NULL, FALSE, FALSE, NULL);
odata.is_stderr = 0;
odata.busy = odata.done = 0;
if (!CreateThread(NULL, 0, stdout_write_thread,
&odata, 0, &out_threadid)) {
fprintf(stderr, "Unable to create output thread\n");
cleanup_exit(1);
}
edata.event = stderrevent;
edata.eventback = CreateEvent(NULL, FALSE, FALSE, NULL);
edata.is_stderr = 1;
edata.busy = edata.done = 0;
if (!CreateThread(NULL, 0, stdout_write_thread,
&edata, 0, &err_threadid)) {
fprintf(stderr, "Unable to create error output thread\n");
cleanup_exit(1);
}
while (1) {
int n;
if (!sending && back->sendok(backhandle)) {
/*
* Create a separate thread to read from stdin. This is
* a total pain, but I can't find another way to do it:
*
* - an overlapped ReadFile or ReadFileEx just doesn't
* happen; we get failure from ReadFileEx, and
* ReadFile blocks despite being given an OVERLAPPED
* structure. Perhaps we can't do overlapped reads
* on consoles. WHY THE HELL NOT?
*
* - WaitForMultipleObjects(netevent, console) doesn't
* work, because it signals the console when
* _anything_ happens, including mouse motions and
* other things that don't cause data to be readable
* - so we're back to ReadFile blocking.
*/
idata.event = stdinevent;
idata.eventback = CreateEvent(NULL, FALSE, FALSE, NULL);
if (!CreateThread(NULL, 0, stdin_read_thread,
&idata, 0, &in_threadid)) {
fprintf(stderr, "Unable to create input thread\n");
cleanup_exit(1);
}
sending = TRUE;
}
n = MsgWaitForMultipleObjects(4, handles, FALSE, INFINITE,
QS_POSTMESSAGE);
if (n == 0) {
WSANETWORKEVENTS things;
SOCKET socket;
extern SOCKET first_socket(int *), next_socket(int *);
extern int select_result(WPARAM, LPARAM);
int i, socketstate;
/*
* We must not call select_result() for any socket
* until we have finished enumerating within the tree.
* This is because select_result() may close the socket
* and modify the tree.
*/
/* Count the active sockets. */
i = 0;
for (socket = first_socket(&socketstate);
socket != INVALID_SOCKET;
socket = next_socket(&socketstate)) i++;
/* Expand the buffer if necessary. */
if (i > sksize) {
sksize = i + 16;
sklist = sresize(sklist, sksize, SOCKET);
}
/* Retrieve the sockets into sklist. */
skcount = 0;
for (socket = first_socket(&socketstate);
socket != INVALID_SOCKET;
socket = next_socket(&socketstate)) {
sklist[skcount++] = socket;
}
/* Now we're done enumerating; go through the list. */
for (i = 0; i < skcount; i++) {
WPARAM wp;
socket = sklist[i];
wp = (WPARAM) socket;
if (!p_WSAEnumNetworkEvents(socket, NULL, &things)) {
static const struct { int bit, mask; } eventtypes[] = {
{FD_CONNECT_BIT, FD_CONNECT},
{FD_READ_BIT, FD_READ},
{FD_CLOSE_BIT, FD_CLOSE},
{FD_OOB_BIT, FD_OOB},
{FD_WRITE_BIT, FD_WRITE},
{FD_ACCEPT_BIT, FD_ACCEPT},
};
int e;
noise_ultralight(socket);
noise_ultralight(things.lNetworkEvents);
for (e = 0; e < lenof(eventtypes); e++)
if (things.lNetworkEvents & eventtypes[e].mask) {
LPARAM lp;
int err = things.iErrorCode[eventtypes[e].bit];
lp = WSAMAKESELECTREPLY(eventtypes[e].mask, err);
connopen &= select_result(wp, lp);
}
}
}
} else if (n == 1) {
reading = 0;
noise_ultralight(idata.len);
if (connopen && back->socket(backhandle) != NULL) {
if (idata.len > 0) {
back->send(backhandle, idata.buffer, idata.len);
} else {
back->special(backhandle, TS_EOF);
}
}
} else if (n == 2) {
odata.busy = 0;
if (!odata.writeret) {
fprintf(stderr, "Unable to write to standard output\n");
cleanup_exit(0);
}
bufchain_consume(&stdout_data, odata.lenwritten);
if (bufchain_size(&stdout_data) > 0)
try_output(0);
if (connopen && back->socket(backhandle) != NULL) {
back->unthrottle(backhandle, bufchain_size(&stdout_data) +
bufchain_size(&stderr_data));
}
} else if (n == 3) {
edata.busy = 0;
if (!edata.writeret) {
fprintf(stderr, "Unable to write to standard output\n");
cleanup_exit(0);
}
bufchain_consume(&stderr_data, edata.lenwritten);
if (bufchain_size(&stderr_data) > 0)
try_output(1);
if (connopen && back->socket(backhandle) != NULL) {
back->unthrottle(backhandle, bufchain_size(&stdout_data) +
bufchain_size(&stderr_data));
}
} else if (n == 4) {
MSG msg;
while (PeekMessage(&msg, INVALID_HANDLE_VALUE,
WM_AGENT_CALLBACK, WM_AGENT_CALLBACK,
PM_REMOVE)) {
struct agent_callback *c = (struct agent_callback *)msg.lParam;
c->callback(c->callback_ctx, c->data, c->len);
sfree(c);
}
}
if (!reading && back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
SetEvent(idata.eventback);
reading = 1;
}
if ((!connopen || back->socket(backhandle) == NULL) &&
bufchain_size(&stdout_data) == 0 &&
bufchain_size(&stderr_data) == 0)
break; /* we closed the connection */
}
exitcode = back->exitcode(backhandle);
if (exitcode < 0) {
fprintf(stderr, "Remote process exit code unavailable\n");
exitcode = 1; /* this is an error condition */
}
cleanup_exit(exitcode);
return 0; /* placate compiler warning */
}
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