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mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-10 09:58:01 +00:00
putty-source/plink.c
Simon Tatham c171bb0a2c Fix a subtle bug affecting multiple-socket handling in Plink. (Was
interfering with X forwarding.)
Details of bug: the event object used as the target of
WSAEventSelect is created in such a way that it is automatically
reset when it releases a thread from WaitFor*Objects. Subsequently,
a read on the first socket in the list causes another network event
if not all the available data was read; thus the event object is set
again. Then, WSAEnumNetworkEvents is called again for the _second_
socket, and is passed the network event, which it therefore resets.
So an event has been dropped, and things only get restarted when
some more data arrives on the first socket.

[originally from svn r888]
2001-01-23 10:19:17 +00:00

588 lines
19 KiB
C

/*
* PLink - a command-line (stdin/stdout) variant of PuTTY.
*/
#ifndef AUTO_WINSOCK
#include <winsock2.h>
#endif
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#define PUTTY_DO_GLOBALS /* actually _define_ globals */
#include "putty.h"
#include "storage.h"
#include "tree234.h"
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);
WSACleanup();
exit(1);
}
void connection_fatal (char *p, ...) {
va_list ap;
fprintf(stderr, "FATAL ERROR: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
WSACleanup();
exit(1);
}
static char *password = NULL;
void logevent(char *string) { }
void verify_ssh_host_key(char *host, int port, char *keytype,
char *keystr, char *fingerprint) {
int ret;
HANDLE hin;
DWORD savemode, i;
static const char absentmsg[] =
"The server's host key is not cached in the registry. You\n"
"have no guarantee that the server is the computer you\n"
"think it is.\n"
"The server's key fingerprint is:\n"
"%s\n"
"If you trust this host, enter \"y\" to add the key to\n"
"PuTTY's cache and carry on connecting.\n"
"If you do not trust this host, enter \"n\" to abandon the\n"
"connection.\n"
"Continue connecting? (y/n) ";
static const char wrongmsg[] =
"WARNING - POTENTIAL SECURITY BREACH!\n"
"The server's host key does not match the one PuTTY has\n"
"cached in the registry. This means that either the\n"
"server administrator has changed the host key, or you\n"
"have actually connected to another computer pretending\n"
"to be the server.\n"
"The new key fingerprint is:\n"
"%s\n"
"If you were expecting this change and trust the new key,\n"
"enter \"y\" to update PuTTY's cache and continue connecting.\n"
"If you want to carry on connecting but without updating\n"
"the cache, enter \"n\".\n"
"If you want to abandon the connection completely, press\n"
"Return to cancel. Pressing Return is the ONLY guaranteed\n"
"safe choice.\n"
"Update cached key? (y/n, Return cancels connection) ";
static const char abandoned[] = "Connection abandoned.\n";
char line[32];
/*
* Verify the key against the registry.
*/
ret = verify_host_key(host, port, keytype, keystr);
if (ret == 0) /* success - key matched OK */
return;
if (ret == 2) /* key was different */
fprintf(stderr, wrongmsg, fingerprint);
if (ret == 1) /* key was absent */
fprintf(stderr, absentmsg, fingerprint);
hin = GetStdHandle(STD_INPUT_HANDLE);
GetConsoleMode(hin, &savemode);
SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
ReadFile(hin, line, sizeof(line)-1, &i, NULL);
SetConsoleMode(hin, savemode);
if (ret == 2) { /* key was different */
if (line[0] != '\0' && line[0] != '\r' && line[0] != '\n') {
if (line[0] == 'y' || line[0] == 'Y')
store_host_key(host, port, keytype, keystr);
} else {
fprintf(stderr, abandoned);
exit(0);
}
}
if (ret == 1) { /* key was absent */
if (line[0] == 'y' || line[0] == 'Y')
store_host_key(host, port, keytype, keystr);
else {
fprintf(stderr, abandoned);
exit(0);
}
}
}
HANDLE outhandle, errhandle;
DWORD orig_console_mode;
WSAEVENT netevent;
void begin_session(void) {
if (!cfg.ldisc_term)
SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), ENABLE_PROCESSED_INPUT);
else
SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), orig_console_mode);
}
void from_backend(int is_stderr, char *data, int len) {
int pos;
DWORD ret;
HANDLE h = (is_stderr ? errhandle : outhandle);
pos = 0;
while (pos < len) {
if (!WriteFile(h, data+pos, len-pos, &ret, NULL))
return; /* give up in panic */
pos += ret;
}
}
struct input_data {
DWORD len;
char buffer[4096];
HANDLE event, eventback;
};
static int get_password(const char *prompt, char *str, int maxlen)
{
HANDLE hin, hout;
DWORD savemode, i;
if (password) {
static int tried_once = 0;
if (tried_once) {
return 0;
} else {
strncpy(str, password, maxlen);
str[maxlen-1] = '\0';
tried_once = 1;
return 1;
}
}
hin = GetStdHandle(STD_INPUT_HANDLE);
hout = GetStdHandle(STD_OUTPUT_HANDLE);
if (hin == INVALID_HANDLE_VALUE || hout == INVALID_HANDLE_VALUE) {
fprintf(stderr, "Cannot get standard input/output handles");
return 0;
}
GetConsoleMode(hin, &savemode);
SetConsoleMode(hin, (savemode & (~ENABLE_ECHO_INPUT)) |
ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT);
WriteFile(hout, prompt, strlen(prompt), &i, NULL);
ReadFile(hin, str, maxlen-1, &i, NULL);
SetConsoleMode(hin, savemode);
if ((int)i > maxlen) i = maxlen-1; else i = i - 2;
str[i] = '\0';
WriteFile(hout, "\r\n", 2, &i, NULL);
return 1;
}
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;
}
/*
* 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("Options:\n");
printf(" -v show verbose messages\n");
printf(" -ssh force use of ssh protocol\n");
printf(" -P port connect to specified port\n");
printf(" -pw passw login with specified password\n");
exit(1);
}
char *do_select(SOCKET skt, int startup) {
int events;
if (startup) {
events = FD_READ | FD_WRITE | FD_OOB | FD_CLOSE;
} else {
events = 0;
}
if (WSAEventSelect (skt, netevent, events) == SOCKET_ERROR) {
switch (WSAGetLastError()) {
case WSAENETDOWN: return "Network is down";
default: return "WSAAsyncSelect(): unknown error";
}
}
return NULL;
}
int main(int argc, char **argv) {
WSADATA wsadata;
WORD winsock_ver;
WSAEVENT stdinevent;
HANDLE handles[2];
DWORD threadid;
struct input_data idata;
int sending;
int portnumber = -1;
SOCKET *sklist;
int skcount, sksize;
int connopen;
ssh_get_password = get_password;
sklist = NULL; skcount = sksize = 0;
flags = FLAG_STDERR;
/*
* Process the command line.
*/
do_defaults(NULL, &cfg);
default_protocol = cfg.protocol;
default_port = cfg.port;
{
/*
* 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 == '-') {
if (!strcmp(p, "-ssh")) {
default_protocol = cfg.protocol = PROT_SSH;
default_port = cfg.port = 22;
} else if (!strcmp(p, "-telnet")) {
default_protocol = cfg.protocol = PROT_TELNET;
default_port = cfg.port = 23;
} else if (!strcmp(p, "-raw")) {
default_protocol = cfg.protocol = PROT_RAW;
} else if (!strcmp(p, "-v")) {
flags |= FLAG_VERBOSE;
} else if (!strcmp(p, "-log")) {
logfile = "putty.log";
} else if (!strcmp(p, "-pw") && argc > 1) {
--argc, password = *++argv;
} else if (!strcmp(p, "-l") && argc > 1) {
char *username;
--argc, username = *++argv;
strncpy(cfg.username, username, sizeof(cfg.username));
cfg.username[sizeof(cfg.username)-1] = '\0';
} else if (!strcmp(p, "-P") && argc > 1) {
--argc, portnumber = atoi(*++argv);
}
} 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 = 22;
} else
cfg = cfg2;
} 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 = 22;
}
}
} else {
int len = sizeof(cfg.remote_cmd) - 1;
char *cp = cfg.remote_cmd;
int len2;
strncpy(cp, p, len); cp[len] = '\0';
len2 = strlen(cp); len -= len2; cp += len2;
while (--argc) {
if (len > 0)
len--, *cp++ = ' ';
strncpy(cp, *++argv, len); cp[len] = '\0';
len2 = strlen(cp); len -= len2; cp += len2;
}
cfg.nopty = TRUE; /* command => no terminal */
cfg.ldisc_term = TRUE; /* use stdin like a line buffer */
break; /* done with cmdline */
}
}
}
if (!*cfg.host) {
usage();
}
if (!*cfg.remote_cmd)
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;
/*
* Initialise WinSock.
*/
winsock_ver = MAKEWORD(2, 0);
if (WSAStartup(winsock_ver, &wsadata)) {
MessageBox(NULL, "Unable to initialise WinSock", "WinSock Error",
MB_OK | MB_ICONEXCLAMATION);
return 1;
}
if (LOBYTE(wsadata.wVersion) != 2 || HIBYTE(wsadata.wVersion) != 0) {
MessageBox(NULL, "WinSock version is incompatible with 2.0",
"WinSock Error", MB_OK | MB_ICONEXCLAMATION);
WSACleanup();
return 1;
}
sk_init();
/*
* Start up the connection.
*/
netevent = CreateEvent(NULL, FALSE, FALSE, NULL);
{
char *error;
char *realhost;
error = back->init (cfg.host, cfg.port, &realhost);
if (error) {
fprintf(stderr, "Unable to open connection:\n%s", error);
return 1;
}
}
connopen = 1;
stdinevent = CreateEvent(NULL, FALSE, FALSE, NULL);
GetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), &orig_console_mode);
SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), ENABLE_PROCESSED_INPUT);
outhandle = GetStdHandle(STD_OUTPUT_HANDLE);
errhandle = GetStdHandle(STD_ERROR_HANDLE);
/*
* 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;
sending = FALSE;
while (1) {
int n;
if (!sending && back->sendok()) {
/*
* 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, &threadid)) {
fprintf(stderr, "Unable to create second thread\n");
exit(1);
}
sending = TRUE;
}
n = WaitForMultipleObjects(2, handles, FALSE, INFINITE);
if (n == 0) {
WSANETWORKEVENTS things;
enum234 e;
SOCKET socket;
extern SOCKET first_socket(enum234 *), next_socket(enum234 *);
extern int select_result(WPARAM, LPARAM);
int i;
/*
* 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(&e); socket != INVALID_SOCKET;
socket = next_socket(&e))
i++;
/* Expand the buffer if necessary. */
if (i > sksize) {
sksize = i+16;
sklist = srealloc(sklist, sksize * sizeof(*sklist));
}
/* Retrieve the sockets into sklist. */
skcount = 0;
for (socket = first_socket(&e); socket != INVALID_SOCKET;
socket = next_socket(&e)) {
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 (!WSAEnumNetworkEvents(socket, NULL, &things)) {
noise_ultralight(socket);
noise_ultralight(things.lNetworkEvents);
if (things.lNetworkEvents & FD_READ)
connopen &= select_result(wp, (LPARAM)FD_READ);
if (things.lNetworkEvents & FD_CLOSE)
connopen &= select_result(wp, (LPARAM)FD_CLOSE);
if (things.lNetworkEvents & FD_OOB)
connopen &= select_result(wp, (LPARAM)FD_OOB);
if (things.lNetworkEvents & FD_WRITE)
connopen &= select_result(wp, (LPARAM)FD_WRITE);
}
}
} else if (n == 1) {
noise_ultralight(idata.len);
if (idata.len > 0) {
back->send(idata.buffer, idata.len);
} else {
back->special(TS_EOF);
}
SetEvent(idata.eventback);
}
if (!connopen || back->socket() == NULL)
break; /* we closed the connection */
}
WSACleanup();
return 0;
}