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putty/winnet.c

1085 строки
28 KiB
C
Исходник Ответственный История

/*
* Windows networking abstraction.
*
* Due to this clean abstraction it was possible
* to easily implement IPv6 support :)
*
* IPv6 patch 1 (27 October 2000) Jeroen Massar <jeroen@unfix.org>
* - Preliminary hacked IPv6 support.
* - Connecting to IPv6 address (eg fec0:4242:4242:100:2d0:b7ff:fe8f:5d42) works.
* - Connecting to IPv6 hostname (eg heaven.ipv6.unfix.org) works.
* - Compiles as either IPv4 or IPv6.
*
* IPv6 patch 2 (29 October 2000) Jeroen Massar <jeroen@unfix.org>
* - When compiled as IPv6 it also allows connecting to IPv4 hosts.
* - Added some more documentation.
*
* IPv6 patch 3 (18 November 2000) Jeroen Massar <jeroen@unfix.org>
* - It now supports dynamically loading the IPv6 resolver dll's.
* This way we should be able to distribute one (1) binary
* which supports both IPv4 and IPv6.
* - getaddrinfo() and getnameinfo() are loaded dynamicaly if possible.
* - in6addr_any is defined in this file so we don't need to link to wship6.lib
* - The patch is now more unified so that we can still
* remove all IPv6 support by undef'ing IPV6.
* But where it fallsback to IPv4 it uses the IPv4 code which is already in place...
* - Canonical name resolving works.
*
* IPv6 patch 4 (07 January 2001) Jeroen Massar <jeroen@unfix.org>
* - patch against CVS of today, will be submitted to the bugs list
* as a 'cvs diff -u' on Simon's request...
*
*/
/*
* Define IPV6 to have IPv6 on-the-fly-loading support.
* This means that one doesn't have to have an IPv6 stack to use it.
* But if an IPv6 stack is found it is used with a fallback to IPv4.
*/
/* #define IPV6 1 */
#ifdef IPV6
#include <winsock2.h>
#include <ws2tcpip.h>
#include <tpipv6.h>
#else
#include <winsock.h>
#endif
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#define DEFINE_PLUG_METHOD_MACROS
#include "putty.h"
#include "network.h"
#include "tree234.h"
struct Socket_tag {
struct socket_function_table *fn;
/* the above variable absolutely *must* be the first in this structure */
char *error;
SOCKET s;
Plug plug;
void *private_ptr;
bufchain output_data;
int connected;
int writable;
int frozen; /* this causes readability notifications to be ignored */
int frozen_readable; /* this means we missed at least one readability
* notification while we were frozen */
int localhost_only; /* for listening sockets */
char oobdata[1];
int sending_oob;
int oobinline;
int pending_error; /* in case send() returns error */
};
/*
* We used to typedef struct Socket_tag *Socket.
*
* Since we have made the networking abstraction slightly more
* abstract, Socket no longer means a tcp socket (it could mean
* an ssl socket). So now we must use Actual_Socket when we know
* we are talking about a tcp socket.
*/
typedef struct Socket_tag *Actual_Socket;
struct SockAddr_tag {
char *error;
/* address family this belongs to, AF_INET for IPv4, AF_INET6 for IPv6. */
int family;
unsigned long address; /* Address IPv4 style. */
#ifdef IPV6
struct addrinfo *ai; /* Address IPv6 style. */
#endif
};
static tree234 *sktree;
static int cmpfortree(void *av, void *bv)
{
Actual_Socket a = (Actual_Socket) av, b = (Actual_Socket) bv;
unsigned long as = (unsigned long) a->s, bs = (unsigned long) b->s;
if (as < bs)
return -1;
if (as > bs)
return +1;
return 0;
}
static int cmpforsearch(void *av, void *bv)
{
Actual_Socket b = (Actual_Socket) bv;
unsigned long as = (unsigned long) av, bs = (unsigned long) b->s;
if (as < bs)
return -1;
if (as > bs)
return +1;
return 0;
}
void sk_init(void)
{
sktree = newtree234(cmpfortree);
}
char *winsock_error_string(int error)
{
switch (error) {
case WSAEACCES:
return "Network error: Permission denied";
case WSAEADDRINUSE:
return "Network error: Address already in use";
case WSAEADDRNOTAVAIL:
return "Network error: Cannot assign requested address";
case WSAEAFNOSUPPORT:
return
"Network error: Address family not supported by protocol family";
case WSAEALREADY:
return "Network error: Operation already in progress";
case WSAECONNABORTED:
return "Network error: Software caused connection abort";
case WSAECONNREFUSED:
return "Network error: Connection refused";
case WSAECONNRESET:
return "Network error: Connection reset by peer";
case WSAEDESTADDRREQ:
return "Network error: Destination address required";
case WSAEFAULT:
return "Network error: Bad address";
case WSAEHOSTDOWN:
return "Network error: Host is down";
case WSAEHOSTUNREACH:
return "Network error: No route to host";
case WSAEINPROGRESS:
return "Network error: Operation now in progress";
case WSAEINTR:
return "Network error: Interrupted function call";
case WSAEINVAL:
return "Network error: Invalid argument";
case WSAEISCONN:
return "Network error: Socket is already connected";
case WSAEMFILE:
return "Network error: Too many open files";
case WSAEMSGSIZE:
return "Network error: Message too long";
case WSAENETDOWN:
return "Network error: Network is down";
case WSAENETRESET:
return "Network error: Network dropped connection on reset";
case WSAENETUNREACH:
return "Network error: Network is unreachable";
case WSAENOBUFS:
return "Network error: No buffer space available";
case WSAENOPROTOOPT:
return "Network error: Bad protocol option";
case WSAENOTCONN:
return "Network error: Socket is not connected";
case WSAENOTSOCK:
return "Network error: Socket operation on non-socket";
case WSAEOPNOTSUPP:
return "Network error: Operation not supported";
case WSAEPFNOSUPPORT:
return "Network error: Protocol family not supported";
case WSAEPROCLIM:
return "Network error: Too many processes";
case WSAEPROTONOSUPPORT:
return "Network error: Protocol not supported";
case WSAEPROTOTYPE:
return "Network error: Protocol wrong type for socket";
case WSAESHUTDOWN:
return "Network error: Cannot send after socket shutdown";
case WSAESOCKTNOSUPPORT:
return "Network error: Socket type not supported";
case WSAETIMEDOUT:
return "Network error: Connection timed out";
case WSAEWOULDBLOCK:
return "Network error: Resource temporarily unavailable";
case WSAEDISCON:
return "Network error: Graceful shutdown in progress";
default:
return "Unknown network error";
}
}
SockAddr sk_namelookup(char *host, char **canonicalname)
{
SockAddr ret = smalloc(sizeof(struct SockAddr_tag));
unsigned long a;
struct hostent *h = NULL;
char realhost[8192];
/* Clear the structure and default to IPv4. */
memset(ret, 0, sizeof(struct SockAddr_tag));
ret->family = 0; /* We set this one when we have resolved the host. */
*realhost = '\0';
if ((a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
#ifdef IPV6
/* Try to get the getaddrinfo() function from wship6.dll */
/* This way one doesn't need to have IPv6 dll's to use PuTTY and
* it will fallback to IPv4. */
typedef int (CALLBACK * FGETADDRINFO) (const char *nodename,
const char *servname,
const struct addrinfo *
hints,
struct addrinfo ** res);
FGETADDRINFO fGetAddrInfo = NULL;
HINSTANCE dllWSHIP6 = LoadLibrary("wship6.dll");
if (dllWSHIP6)
fGetAddrInfo = (FGETADDRINFO) GetProcAddress(dllWSHIP6,
"getaddrinfo");
/*
* Use fGetAddrInfo when it's available (which usually also
* means IPv6 is installed...)
*/
if (fGetAddrInfo) {
/*debug(("Resolving \"%s\" with getaddrinfo() (IPv4+IPv6 capable)...\n", host)); */
if (fGetAddrInfo(host, NULL, NULL, &ret->ai) == 0)
ret->family = ret->ai->ai_family;
} else
#endif
{
/*
* Otherwise use the IPv4-only gethostbyname...
* (NOTE: we don't use gethostbyname as a
* fallback!)
*/
if (ret->family == 0) {
/*debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); */
if ( (h = gethostbyname(host)) )
ret->family = AF_INET;
}
}
/*debug(("Done resolving...(family is %d) AF_INET = %d, AF_INET6 = %d\n", ret->family, AF_INET, AF_INET6)); */
if (ret->family == 0) {
DWORD err = WSAGetLastError();
ret->error = (err == WSAENETDOWN ? "Network is down" :
err ==
WSAHOST_NOT_FOUND ? "Host does not exist" : err
== WSATRY_AGAIN ? "Host not found" :
#ifdef IPV6
fGetAddrInfo ? "getaddrinfo: unknown error" :
#endif
"gethostbyname: unknown error");
#ifdef DEBUG
{
LPVOID lpMsgBuf;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS, NULL, err,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) & lpMsgBuf, 0, NULL);
/*debug(("Error %ld: %s (h=%lx)\n", err, lpMsgBuf, h)); */
/* Free the buffer. */
LocalFree(lpMsgBuf);
}
#endif
} else {
ret->error = NULL;
#ifdef IPV6
/* If we got an address info use that... */
if (ret->ai) {
typedef int (CALLBACK * FGETNAMEINFO)
(const struct sockaddr FAR * sa, socklen_t salen,
char FAR * host, size_t hostlen, char FAR * serv,
size_t servlen, int flags);
FGETNAMEINFO fGetNameInfo = NULL;
/* Are we in IPv4 fallback mode? */
/* We put the IPv4 address into the a variable so we can further-on use the IPv4 code... */
if (ret->family == AF_INET)
memcpy(&a,
(char *) &((SOCKADDR_IN *) ret->ai->
ai_addr)->sin_addr, sizeof(a));
/* Now let's find that canonicalname... */
if ((dllWSHIP6)
&& (fGetNameInfo =
(FGETNAMEINFO) GetProcAddress(dllWSHIP6,
"getnameinfo"))) {
if (fGetNameInfo
((struct sockaddr *) ret->ai->ai_addr,
ret->family ==
AF_INET ? sizeof(SOCKADDR_IN) :
sizeof(SOCKADDR_IN6), realhost,
sizeof(realhost), NULL, 0, 0) != 0) {
strncpy(realhost, host, sizeof(realhost));
}
}
}
/* We used the IPv4-only gethostbyname()... */
else
#endif
{
memcpy(&a, h->h_addr, sizeof(a));
/* This way we are always sure the h->h_name is valid :) */
strncpy(realhost, h->h_name, sizeof(realhost));
}
}
#ifdef IPV6
FreeLibrary(dllWSHIP6);
#endif
} else {
/*
* This must be a numeric IPv4 address because it caused a
* success return from inet_addr.
*/
ret->family = AF_INET;
strncpy(realhost, host, sizeof(realhost));
}
ret->address = ntohl(a);
realhost[lenof(realhost)-1] = '\0';
*canonicalname = smalloc(1+strlen(realhost));
strcpy(*canonicalname, realhost);
return ret;
}
void sk_getaddr(SockAddr addr, char *buf, int buflen)
{
#ifdef IPV6
if (addr->family == AF_INET) {
#endif
struct in_addr a;
a.s_addr = htonl(addr->address);
strncpy(buf, inet_ntoa(a), buflen);
#ifdef IPV6
} else {
FIXME; /* I don't know how to get a text form of an IPv6 address. */
}
#endif
}
void sk_addr_free(SockAddr addr)
{
sfree(addr);
}
static Plug sk_tcp_plug(Socket sock, Plug p)
{
Actual_Socket s = (Actual_Socket) sock;
Plug ret = s->plug;
if (p)
s->plug = p;
return ret;
}
static void sk_tcp_flush(Socket s)
{
/*
* We send data to the socket as soon as we can anyway,
* so we don't need to do anything here. :-)
*/
}
static void sk_tcp_close(Socket s);
static int sk_tcp_write(Socket s, char *data, int len);
static int sk_tcp_write_oob(Socket s, char *data, int len);
static char *sk_tcp_socket_error(Socket s);
extern char *do_select(SOCKET skt, int startup);
Socket sk_register(void *sock, Plug plug)
{
static struct socket_function_table fn_table = {
sk_tcp_plug,
sk_tcp_close,
sk_tcp_write,
sk_tcp_write_oob,
sk_tcp_flush,
sk_tcp_socket_error
};
DWORD err;
char *errstr;
Actual_Socket ret;
/*
* Create Socket structure.
*/
ret = smalloc(sizeof(struct Socket_tag));
ret->fn = &fn_table;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->writable = 1; /* to start with */
ret->sending_oob = 0;
ret->frozen = 1;
ret->frozen_readable = 0;
ret->localhost_only = 0; /* unused, but best init anyway */
ret->pending_error = 0;
ret->s = (SOCKET)sock;
if (ret->s == INVALID_SOCKET) {
err = WSAGetLastError();
ret->error = winsock_error_string(err);
return (Socket) ret;
}
ret->oobinline = 0;
/* Set up a select mechanism. This could be an AsyncSelect on a
* window, or an EventSelect on an event object. */
errstr = do_select(ret->s, 1);
if (errstr) {
ret->error = errstr;
return (Socket) ret;
}
add234(sktree, ret);
return (Socket) ret;
}
Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
Plug plug)
{
static struct socket_function_table fn_table = {
sk_tcp_plug,
sk_tcp_close,
sk_tcp_write,
sk_tcp_write_oob,
sk_tcp_flush,
sk_tcp_socket_error
};
SOCKET s;
#ifdef IPV6
SOCKADDR_IN6 a6;
#endif
SOCKADDR_IN a;
DWORD err;
char *errstr;
Actual_Socket ret;
short localport;
/*
* Create Socket structure.
*/
ret = smalloc(sizeof(struct Socket_tag));
ret->fn = &fn_table;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->connected = 0; /* to start with */
ret->writable = 0; /* to start with */
ret->sending_oob = 0;
ret->frozen = 0;
ret->frozen_readable = 0;
ret->localhost_only = 0; /* unused, but best init anyway */
ret->pending_error = 0;
/*
* Open socket.
*/
s = socket(addr->family, SOCK_STREAM, 0);
ret->s = s;
if (s == INVALID_SOCKET) {
err = WSAGetLastError();
ret->error = winsock_error_string(err);
return (Socket) ret;
}
ret->oobinline = oobinline;
if (oobinline) {
BOOL b = TRUE;
setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b));
}
/*
* Bind to local address.
*/
if (privport)
localport = 1023; /* count from 1023 downwards */
else
localport = 0; /* just use port 0 (ie winsock picks) */
/* Loop round trying to bind */
while (1) {
int retcode;
#ifdef IPV6
if (addr->family == AF_INET6) {
memset(&a6, 0, sizeof(a6));
a6.sin6_family = AF_INET6;
/*a6.sin6_addr = in6addr_any; *//* == 0 */
a6.sin6_port = htons(localport);
} else
#endif
{
a.sin_family = AF_INET;
a.sin_addr.s_addr = htonl(INADDR_ANY);
a.sin_port = htons(localport);
}
#ifdef IPV6
retcode = bind(s, (addr->family == AF_INET6 ?
(struct sockaddr *) &a6 :
(struct sockaddr *) &a),
(addr->family ==
AF_INET6 ? sizeof(a6) : sizeof(a)));
#else
retcode = bind(s, (struct sockaddr *) &a, sizeof(a));
#endif
if (retcode != SOCKET_ERROR) {
err = 0;
break; /* done */
} else {
err = WSAGetLastError();
if (err != WSAEADDRINUSE) /* failed, for a bad reason */
break;
}
if (localport == 0)
break; /* we're only looping once */
localport--;
if (localport == 0)
break; /* we might have got to the end */
}
if (err) {
ret->error = winsock_error_string(err);
return (Socket) ret;
}
/*
* Connect to remote address.
*/
#ifdef IPV6
if (addr->family == AF_INET6) {
memset(&a, 0, sizeof(a));
a6.sin6_family = AF_INET6;
a6.sin6_port = htons((short) port);
a6.sin6_addr =
((struct sockaddr_in6 *) addr->ai->ai_addr)->sin6_addr;
} else
#endif
{
a.sin_family = AF_INET;
a.sin_addr.s_addr = htonl(addr->address);
a.sin_port = htons((short) port);
}
/* Set up a select mechanism. This could be an AsyncSelect on a
* window, or an EventSelect on an event object. */
errstr = do_select(s, 1);
if (errstr) {
ret->error = errstr;
return (Socket) ret;
}
if ((
#ifdef IPV6
connect(s, ((addr->family == AF_INET6) ?
(struct sockaddr *) &a6 : (struct sockaddr *) &a),
(addr->family == AF_INET6) ? sizeof(a6) : sizeof(a))
#else
connect(s, (struct sockaddr *) &a, sizeof(a))
#endif
) == SOCKET_ERROR) {
err = WSAGetLastError();
/*
* We expect a potential EWOULDBLOCK here, because the
* chances are the front end has done a select for
* FD_CONNECT, so that connect() will complete
* asynchronously.
*/
if ( err != WSAEWOULDBLOCK ) {
ret->error = winsock_error_string(err);
return (Socket) ret;
}
} else {
/*
* If we _don't_ get EWOULDBLOCK, the connect has completed
* and we should set the socket as writable.
*/
ret->writable = 1;
}
add234(sktree, ret);
return (Socket) ret;
}
Socket sk_newlistener(int port, Plug plug, int local_host_only)
{
static struct socket_function_table fn_table = {
sk_tcp_plug,
sk_tcp_close,
sk_tcp_write,
sk_tcp_write_oob,
sk_tcp_flush,
sk_tcp_socket_error
};
SOCKET s;
#ifdef IPV6
SOCKADDR_IN6 a6;
#endif
SOCKADDR_IN a;
DWORD err;
char *errstr;
Actual_Socket ret;
int retcode;
int on = 1;
/*
* Create Socket structure.
*/
ret = smalloc(sizeof(struct Socket_tag));
ret->fn = &fn_table;
ret->error = NULL;
ret->plug = plug;
bufchain_init(&ret->output_data);
ret->writable = 0; /* to start with */
ret->sending_oob = 0;
ret->frozen = 0;
ret->frozen_readable = 0;
ret->localhost_only = local_host_only;
ret->pending_error = 0;
/*
* Open socket.
*/
s = socket(AF_INET, SOCK_STREAM, 0);
ret->s = s;
if (s == INVALID_SOCKET) {
err = WSAGetLastError();
ret->error = winsock_error_string(err);
return (Socket) ret;
}
ret->oobinline = 0;
setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
#ifdef IPV6
if (addr->family == AF_INET6) {
memset(&a6, 0, sizeof(a6));
a6.sin6_family = AF_INET6;
if (local_host_only)
a6.sin6_addr = in6addr_loopback;
else
a6.sin6_addr = in6addr_any;
a6.sin6_port = htons(port);
} else
#endif
{
a.sin_family = AF_INET;
if (local_host_only)
a.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
else
a.sin_addr.s_addr = htonl(INADDR_ANY);
a.sin_port = htons((short)port);
}
#ifdef IPV6
retcode = bind(s, (addr->family == AF_INET6 ?
(struct sockaddr *) &a6 :
(struct sockaddr *) &a),
(addr->family ==
AF_INET6 ? sizeof(a6) : sizeof(a)));
#else
retcode = bind(s, (struct sockaddr *) &a, sizeof(a));
#endif
if (retcode != SOCKET_ERROR) {
err = 0;
} else {
err = WSAGetLastError();
}
if (err) {
ret->error = winsock_error_string(err);
return (Socket) ret;
}
if (listen(s, SOMAXCONN) == SOCKET_ERROR) {
closesocket(s);
ret->error = winsock_error_string(err);
return (Socket) ret;
}
/* Set up a select mechanism. This could be an AsyncSelect on a
* window, or an EventSelect on an event object. */
errstr = do_select(s, 1);
if (errstr) {
ret->error = errstr;
return (Socket) ret;
}
add234(sktree, ret);
return (Socket) ret;
}
static void sk_tcp_close(Socket sock)
{
extern char *do_select(SOCKET skt, int startup);
Actual_Socket s = (Actual_Socket) sock;
del234(sktree, s);
do_select(s->s, 0);
closesocket(s->s);
sfree(s);
}
/*
* The function which tries to send on a socket once it's deemed
* writable.
*/
void try_send(Actual_Socket s)
{
while (s->sending_oob || bufchain_size(&s->output_data) > 0) {
int nsent;
DWORD err;
void *data;
int len, urgentflag;
if (s->sending_oob) {
urgentflag = MSG_OOB;
len = s->sending_oob;
data = &s->oobdata;
} else {
urgentflag = 0;
bufchain_prefix(&s->output_data, &data, &len);
}
nsent = send(s->s, data, len, urgentflag);
noise_ultralight(nsent);
if (nsent <= 0) {
err = (nsent < 0 ? WSAGetLastError() : 0);
if ((err < WSABASEERR && nsent < 0) || err == WSAEWOULDBLOCK) {
/*
* Perfectly normal: we've sent all we can for the moment.
*
* (Some WinSock send() implementations can return
* <0 but leave no sensible error indication -
* WSAGetLastError() is called but returns zero or
* a small number - so we check that case and treat
* it just like WSAEWOULDBLOCK.)
*/
s->writable = FALSE;
return;
} else if (nsent == 0 ||
err == WSAECONNABORTED || err == WSAECONNRESET) {
/*
* If send() returns CONNABORTED or CONNRESET, we
* unfortunately can't just call plug_closing(),
* because it's quite likely that we're currently
* _in_ a call from the code we'd be calling back
* to, so we'd have to make half the SSH code
* reentrant. Instead we flag a pending error on
* the socket, to be dealt with (by calling
* plug_closing()) at some suitable future moment.
*/
s->pending_error = err;
return;
} else {
fatalbox(winsock_error_string(err));
}
} else {
if (s->sending_oob) {
if (nsent < len) {
memmove(s->oobdata, s->oobdata+nsent, len-nsent);
s->sending_oob = len - nsent;
} else {
s->sending_oob = 0;
}
} else {
bufchain_consume(&s->output_data, nsent);
}
}
}
}
static int sk_tcp_write(Socket sock, char *buf, int len)
{
Actual_Socket s = (Actual_Socket) sock;
/*
* Add the data to the buffer list on the socket.
*/
bufchain_add(&s->output_data, buf, len);
/*
* Now try sending from the start of the buffer list.
*/
if (s->writable)
try_send(s);
return bufchain_size(&s->output_data);
}
static int sk_tcp_write_oob(Socket sock, char *buf, int len)
{
Actual_Socket s = (Actual_Socket) sock;
/*
* Replace the buffer list on the socket with the data.
*/
bufchain_clear(&s->output_data);
assert(len <= sizeof(s->oobdata));
memcpy(s->oobdata, buf, len);
s->sending_oob = len;
/*
* Now try sending from the start of the buffer list.
*/
if (s->writable)
try_send(s);
return s->sending_oob;
}
int select_result(WPARAM wParam, LPARAM lParam)
{
int ret, open;
DWORD err;
char buf[20480]; /* nice big buffer for plenty of speed */
Actual_Socket s;
u_long atmark;
/* wParam is the socket itself */
s = find234(sktree, (void *) wParam, cmpforsearch);
if (!s)
return 1; /* boggle */
if ((err = WSAGETSELECTERROR(lParam)) != 0) {
/*
* An error has occurred on this socket. Pass it to the
* plug.
*/
return plug_closing(s->plug, winsock_error_string(err), err, 0);
}
noise_ultralight(lParam);
switch (WSAGETSELECTEVENT(lParam)) {
case FD_CONNECT:
s->connected = s->writable = 1;
break;
case FD_READ:
/* In the case the socket is still frozen, we don't even bother */
if (s->frozen) {
s->frozen_readable = 1;
break;
}
/*
* We have received data on the socket. For an oobinline
* socket, this might be data _before_ an urgent pointer,
* in which case we send it to the back end with type==1
* (data prior to urgent).
*/
if (s->oobinline) {
atmark = 1;
ioctlsocket(s->s, SIOCATMARK, &atmark);
/*
* Avoid checking the return value from ioctlsocket(),
* on the grounds that some WinSock wrappers don't
* support it. If it does nothing, we get atmark==1,
* which is equivalent to `no OOB pending', so the
* effect will be to non-OOB-ify any OOB data.
*/
} else
atmark = 1;
ret = recv(s->s, buf, sizeof(buf), 0);
noise_ultralight(ret);
if (ret < 0) {
err = WSAGetLastError();
if (err == WSAEWOULDBLOCK) {
break;
}
}
if (ret < 0) {
return plug_closing(s->plug, winsock_error_string(err), err,
0);
} else if (0 == ret) {
return plug_closing(s->plug, NULL, 0, 0);
} else {
return plug_receive(s->plug, atmark ? 0 : 1, buf, ret);
}
break;
case FD_OOB:
/*
* This will only happen on a non-oobinline socket. It
* indicates that we can immediately perform an OOB read
* and get back OOB data, which we will send to the back
* end with type==2 (urgent data).
*/
ret = recv(s->s, buf, sizeof(buf), MSG_OOB);
noise_ultralight(ret);
if (ret <= 0) {
fatalbox(ret == 0 ? "Internal networking trouble" :
winsock_error_string(WSAGetLastError()));
} else {
return plug_receive(s->plug, 2, buf, ret);
}
break;
case FD_WRITE:
{
int bufsize_before, bufsize_after;
s->writable = 1;
bufsize_before = s->sending_oob + bufchain_size(&s->output_data);
try_send(s);
bufsize_after = s->sending_oob + bufchain_size(&s->output_data);
if (bufsize_after < bufsize_before)
plug_sent(s->plug, bufsize_after);
}
break;
case FD_CLOSE:
/* Signal a close on the socket. First read any outstanding data. */
open = 1;
do {
ret = recv(s->s, buf, sizeof(buf), 0);
if (ret < 0) {
err = WSAGetLastError();
if (err == WSAEWOULDBLOCK)
break;
return plug_closing(s->plug, winsock_error_string(err),
err, 0);
} else {
if (ret)
open &= plug_receive(s->plug, 0, buf, ret);
else
open &= plug_closing(s->plug, NULL, 0, 0);
}
} while (ret > 0);
return open;
case FD_ACCEPT:
{
struct sockaddr_in isa;
int addrlen = sizeof(struct sockaddr_in);
SOCKET t; /* socket of connection */
memset(&isa, 0, sizeof(struct sockaddr_in));
err = 0;
t = accept(s->s,&isa,&addrlen);
if (t == INVALID_SOCKET)
{
err = WSAGetLastError();
if (err == WSATRY_AGAIN)
break;
}
if (s->localhost_only &&
ntohl(isa.sin_addr.s_addr) != INADDR_LOOPBACK) {
closesocket(t); /* dodgy WinSock let nonlocal through */
} else if (plug_accepting(s->plug, (void*)t)) {
closesocket(t); /* denied or error */
}
}
}
return 1;
}
/*
* Deal with socket errors detected in try_send().
*/
void net_pending_errors(void)
{
int i;
Actual_Socket s;
/*
* This might be a fiddly business, because it's just possible
* that handling a pending error on one socket might cause
* others to be closed. (I can't think of any reason this might
* happen in current SSH implementation, but to maintain
* generality of this network layer I'll assume the worst.)
*
* So what we'll do is search the socket list for _one_ socket
* with a pending error, and then handle it, and then search
* the list again _from the beginning_. Repeat until we make a
* pass with no socket errors present. That way we are
* protected against the socket list changing under our feet.
*/
do {
for (i = 0; (s = index234(sktree, i)) != NULL; i++) {
if (s->pending_error) {
/*
* An error has occurred on this socket. Pass it to the
* plug.
*/
plug_closing(s->plug,
winsock_error_string(s->pending_error),
s->pending_error, 0);
break;
}
}
} while (s);
}
/*
* Each socket abstraction contains a `void *' private field in
* which the client can keep state.
*/
void sk_set_private_ptr(Socket sock, void *ptr)
{
Actual_Socket s = (Actual_Socket) sock;
s->private_ptr = ptr;
}
void *sk_get_private_ptr(Socket sock)
{
Actual_Socket s = (Actual_Socket) sock;
return s->private_ptr;
}
/*
* Special error values are returned from sk_namelookup and sk_new
* if there's a problem. These functions extract an error message,
* or return NULL if there's no problem.
*/
char *sk_addr_error(SockAddr addr)
{
return addr->error;
}
static char *sk_tcp_socket_error(Socket sock)
{
Actual_Socket s = (Actual_Socket) sock;
return s->error;
}
void sk_set_frozen(Socket sock, int is_frozen)
{
Actual_Socket s = (Actual_Socket) sock;
if (s->frozen == is_frozen)
return;
s->frozen = is_frozen;
if (!is_frozen && s->frozen_readable) {
char c;
recv(s->s, &c, 1, MSG_PEEK);
}
s->frozen_readable = 0;
}
/*
* For Plink: enumerate all sockets currently active.
*/
SOCKET first_socket(int *state)
{
Actual_Socket s;
*state = 0;
s = index234(sktree, (*state)++);
return s ? s->s : INVALID_SOCKET;
}
SOCKET next_socket(int *state)
{
Actual_Socket s = index234(sktree, (*state)++);
return s ? s->s : INVALID_SOCKET;
}
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