[u/mdw/putty] / winnet.c

/*
 * 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 "putty.h"
#include "network.h"
#include "tree234.h"

#define BUFFER_GRANULE 512

struct Socket_tag {
    char *error;
    SOCKET s;
    sk_receiver_t receiver;
    void *private_ptr;
    struct buffer *head, *tail;
    int writable;
    int in_oob, sending_oob;
};

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
    /*
     * We need to have this lengthy enough to hold *any* hostname
     * (including IPv6 reverse...)
     */
    char realhost[8192];
};

struct buffer {
    struct buffer *next;
    int buflen, bufpos;
    char buf[BUFFER_GRANULE];
};

static tree234 *sktree;

static int cmpfortree(void *av, void *bv) {
    Socket a = (Socket)av, b = (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) {
    Socket b = (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;

    /* 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. */
    *canonicalname = ret->realhost;    /* This makes sure we always have a hostname to return. */

    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), ret->realhost,
				     sizeof(ret->realhost), NULL,
				     0, 0) != 0)
		    {
			strncpy(ret->realhost, host,
				sizeof(ret->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(ret->realhost, h->h_name, sizeof(ret->realhost));
#ifdef IPV6
	    }
#endif
	}
#ifdef IPV6
	FreeLibrary(dllWSHIP6);
#endif
    }
    else
    {
        /*
         * Hack inserted to deal with problems with numeric IPs.
         * FIXME: how will this work in IPv6?
         */
        ret->family = AF_INET;
	*canonicalname = host;
    }
    ret->address = ntohl(a);
    return ret;
}

void sk_addr_free(SockAddr addr) {
    sfree(addr);
}

Socket sk_new(SockAddr addr, int port, int privport, sk_receiver_t receiver) {
    SOCKET s;
#ifdef IPV6
    SOCKADDR_IN6 a6;
#endif
    SOCKADDR_IN a;
    DWORD err;
    char *errstr;
    Socket ret;
    extern char *do_select(SOCKET skt, int startup);
    short localport;

    /*
     * Create Socket structure.
     */
    ret = smalloc(sizeof(struct Socket_tag));
    ret->error = NULL;
    ret->receiver = receiver;
    ret->head = ret->tail = NULL;
    ret->writable = 1;		       /* to start with */
    ret->in_oob = FALSE;
    ret->sending_oob = 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 ret;
    }

    /*
     * 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 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);
#ifdef IPV6
    }
    if (connect (s, (addr->family == AF_INET6) ? (struct sockaddr *)&a6 : (struct sockaddr *)&a, (addr->family == AF_INET6) ? sizeof(a6) : sizeof(a)) == SOCKET_ERROR)
#else
	if (connect (s, (struct sockaddr *)&a, sizeof(a)) == SOCKET_ERROR)
#endif
    {
	err = WSAGetLastError();
	ret->error = winsock_error_string(err);
	return 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 ret;
    }

    add234(sktree, ret);

    return ret;
}

void sk_close(Socket s) {
    extern char *do_select(SOCKET skt, int startup);

    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(Socket s) {
    while (s->head) {
	int nsent;
	DWORD err;
        int len, urgentflag;

        if (s->sending_oob) {
            urgentflag = MSG_OOB;
            len = s->sending_oob;
        } else {
            urgentflag = 0;
            len = s->head->buflen - s->head->bufpos;
        }

	nsent = send(s->s, s->head->buf + s->head->bufpos, len, urgentflag);
        noise_ultralight(nsent);
	if (nsent <= 0) {
	    err = (nsent < 0 ? WSAGetLastError() : 0);
	    if (err == WSAEWOULDBLOCK) {
		/* Perfectly normal: we've sent all we can for the moment. */
		s->writable = FALSE;
                return;
	    } else if (nsent == 0 ||
		       err == WSAECONNABORTED ||
		       err == WSAECONNRESET) {
                /*
                 * FIXME. This will have to be done better when we
                 * start managing multiple sockets (e.g. SSH port
                 * forwarding), because if we get CONNRESET while
                 * trying to write a particular forwarded socket
                 * then it isn't necessarily the end of the world.
                 * Ideally I'd like to pass the error code back to
                 * somewhere the next select_result() will see it,
                 * but that might be hard. Perhaps I should pass it
                 * back to be queued in the Windows front end bit.
                 */
                fatalbox(winsock_error_string(err));
	    } else {
		fatalbox(winsock_error_string(err));
	    }
	} else {
	    s->head->bufpos += nsent;
            if (s->sending_oob)
                s->sending_oob -= nsent;
	    if (s->head->bufpos >= s->head->buflen) {
		struct buffer *tmp = s->head;
		s->head = tmp->next;
		sfree(tmp);
		if (!s->head)
		    s->tail = NULL;
	    }
	}
    }
}

void sk_write(Socket s, char *buf, int len) {
    /*
     * Add the data to the buffer list on the socket.
     */
    if (s->tail && s->tail->buflen < BUFFER_GRANULE) {
	int copylen = min(len, BUFFER_GRANULE - s->tail->buflen);
	memcpy(s->tail->buf + s->tail->buflen, buf, copylen);
	buf += copylen;
	len -= copylen;
	s->tail->buflen += copylen;
    }
    while (len > 0) {
	int grainlen = min(len, BUFFER_GRANULE);
	struct buffer *newbuf;
	newbuf = smalloc(sizeof(struct buffer));
	newbuf->bufpos = 0;
	newbuf->buflen = grainlen;
	memcpy(newbuf->buf, buf, grainlen);
	buf += grainlen;
	len -= grainlen;
	if (s->tail)
	    s->tail->next = newbuf;
	else
	    s->head = s->tail = newbuf;
	newbuf->next = NULL;
	s->tail = newbuf;
    }

    /*
     * Now try sending from the start of the buffer list.
     */
    if (s->writable)
	try_send(s);
}

void sk_write_oob(Socket s, char *buf, int len) {
    /*
     * Replace the buffer list on the socket with the data.
     */
    if (!s->head) {
	s->head = smalloc(sizeof(struct buffer));
    } else {
        struct buffer *walk = s->head->next;
        while (walk) {
            struct buffer *tmp = walk;
            walk = tmp->next;
            sfree(tmp);
        }
    }
    s->head->next = NULL;
    s->tail = s->head;
    s->head->buflen = len;
    memcpy(s->head->buf, buf, len);

    /*
     * Set the Urgent marker.
     */
    s->sending_oob = len;

    /*
     * Now try sending from the start of the buffer list.
     */
    if (s->writable)
	try_send(s);
}

int select_result(WPARAM wParam, LPARAM lParam) {
    int ret;
    DWORD err;
    char buf[BUFFER_GRANULE];
    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
         * receiver function.
         */
        return s->receiver(s, 3, winsock_error_string(err), err);
    }

    noise_ultralight(lParam);

    switch (WSAGETSELECTEVENT(lParam)) {
      case FD_READ:
	ret = recv(s->s, buf, sizeof(buf), 0);
	if (ret < 0) {
	    err = WSAGetLastError();
	    if (err == WSAEWOULDBLOCK) {
		break;
	    }
	}
	if (ret < 0) {
	    return s->receiver(s, 3, winsock_error_string(err), err);
	} else {
            int type = s->in_oob ? 2 : 0;
            s->in_oob = FALSE;
	    return s->receiver(s, type, buf, ret);
	}
	break;
      case FD_OOB:
	/*
	 * Read all data up to the OOB marker, and send it to the
	 * receiver with urgent==1 (OOB pending).
	 */
        atmark = 1;
        s->in_oob = TRUE;
        /* Some WinSock wrappers don't support this call, so we
         * deliberately don't check the return value. If the call
         * fails and does nothing, we will get back atmark==1,
         * which is good enough to keep going at least. */
        ioctlsocket(s->s, SIOCATMARK, &atmark);
        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 s->receiver(s, atmark ? 2 : 1, buf, ret);
        }
        break;
      case FD_WRITE:
	s->writable = 1;
	try_send(s);
	break;
      case FD_CLOSE:
	/* Signal a close on the socket. */
	return s->receiver(s, 0, NULL, 0);
	break;
    }

    return 1;
}

/*
 * Each socket abstraction contains a `void *' private field in
 * which the client can keep state.
 */
void sk_set_private_ptr(Socket s, void *ptr) {
    s->private_ptr = ptr;
}
void *sk_get_private_ptr(Socket s) {
    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;
}
char *sk_socket_error(Socket s) {
    return s->error;
}

/*
 * For Plink: enumerate all sockets currently active.
 */
SOCKET first_socket(enum234 *e) {
    Socket s = first234(sktree, e);
    return s ? s->s : INVALID_SOCKET;
}
SOCKET next_socket(enum234 *e) {
    Socket s = next234(e);
    return s ? s->s : INVALID_SOCKET;
}
Commit	Line	Data
2f75bae1	1	/*
2f75bae1	2	* Windows networking abstraction.
c4d8e107	3	*
	4	* Due to this clean abstraction it was possible
	5	* to easily implement IPv6 support :)
	6	*
	7	* IPv6 patch 1 (27 October 2000) Jeroen Massar <jeroen@unfix.org>
	8	* - Preliminary hacked IPv6 support.
	9	* - Connecting to IPv6 address (eg fec0:4242:4242:100:2d0:b7ff:fe8f:5d42) works.
	10	* - Connecting to IPv6 hostname (eg heaven.ipv6.unfix.org) works.
	11	* - Compiles as either IPv4 or IPv6.
	12	*
	13	* IPv6 patch 2 (29 October 2000) Jeroen Massar <jeroen@unfix.org>
	14	* - When compiled as IPv6 it also allows connecting to IPv4 hosts.
	15	* - Added some more documentation.
	16	*
	17	* IPv6 patch 3 (18 November 2000) Jeroen Massar <jeroen@unfix.org>
	18	* - It now supports dynamically loading the IPv6 resolver dll's.
	19	* This way we should be able to distribute one (1) binary
	20	* which supports both IPv4 and IPv6.
	21	* - getaddrinfo() and getnameinfo() are loaded dynamicaly if possible.
	22	* - in6addr_any is defined in this file so we don't need to link to wship6.lib
	23	* - The patch is now more unified so that we can still
	24	* remove all IPv6 support by undef'ing IPV6.
	25	* But where it fallsback to IPv4 it uses the IPv4 code which is already in place...
	26	* - Canonical name resolving works.
	27	*
	28	* IPv6 patch 4 (07 January 2001) Jeroen Massar <jeroen@unfix.org>
	29	* - patch against CVS of today, will be submitted to the bugs list
	30	* as a 'cvs diff -u' on Simon's request...
	31	*
2f75bae1	32	*/
2f75bae1	33
c4d8e107	34	/*
	35	* Define IPV6 to have IPv6 on-the-fly-loading support.
	36	* This means that one doesn't have to have an IPv6 stack to use it.
	37	* But if an IPv6 stack is found it is used with a fallback to IPv4.
	38	*/
	39	/* #define IPV6 1 */
	40
	41	#ifdef IPV6
	42	#include <winsock2.h>
	43	#include <ws2tcpip.h>
	44	#include <tpipv6.h>
	45	#else
2f75bae1	46	#include <winsock.h>
c4d8e107	47	#endif
c4d8e107	48	#include <windows.h>
2f75bae1	49	#include <stdio.h>
49bad831	50	#include <stdlib.h>
2f75bae1	51
	52	#include "putty.h"
	53	#include "network.h"
	54	#include "tree234.h"
	55
	56	#define BUFFER_GRANULE 512
	57
	58	struct Socket_tag {
	59	char *error;
	60	SOCKET s;
	61	sk_receiver_t receiver;
	62	void *private_ptr;
	63	struct buffer head, tail;
	64	int writable;
	65	int in_oob, sending_oob;
	66	};
	67
	68	struct SockAddr_tag {
	69	char *error;
c4d8e107	70	/* address family this belongs to, AF_INET for IPv4, AF_INET6 for IPv6. */
	71	int family;
	72	unsigned long address; /* Address IPv4 style. */
	73	#ifdef IPV6
	74	struct addrinfo ai; / Address IPv6 style. */
	75	#endif
	76	/*
	77	* We need to have this lengthy enough to hold any hostname
	78	* (including IPv6 reverse...)
	79	*/
	80	char realhost[8192];
2f75bae1	81	};
	82
	83	struct buffer {
	84	struct buffer *next;
	85	int buflen, bufpos;
	86	char buf[BUFFER_GRANULE];
	87	};
	88
	89	static tree234 *sktree;
	90
	91	static int cmpfortree(void av, void bv) {
	92	Socket a = (Socket)av, b = (Socket)bv;
	93	unsigned long as = (unsigned long)a->s, bs = (unsigned long)b->s;
	94	if (as < bs) return -1;
	95	if (as > bs) return +1;
	96	return 0;
	97	}
	98
	99	static int cmpforsearch(void av, void bv) {
	100	Socket b = (Socket)bv;
	101	unsigned long as = (unsigned long)av, bs = (unsigned long)b->s;
	102	if (as < bs) return -1;
	103	if (as > bs) return +1;
	104	return 0;
	105	}
	106
	107	void sk_init(void) {
	108	sktree = newtree234(cmpfortree);
	109	}
	110
e74fbad9	111	char *winsock_error_string(int error) {
	112	switch (error) {
	113	case WSAEACCES: return "Network error: Permission denied";
	114	case WSAEADDRINUSE: return "Network error: Address already in use";
	115	case WSAEADDRNOTAVAIL: return "Network error: Cannot assign requested address";
	116	case WSAEAFNOSUPPORT: return "Network error: Address family not supported by protocol family";
	117	case WSAEALREADY: return "Network error: Operation already in progress";
	118	case WSAECONNABORTED: return "Network error: Software caused connection abort";
	119	case WSAECONNREFUSED: return "Network error: Connection refused";
	120	case WSAECONNRESET: return "Network error: Connection reset by peer";
	121	case WSAEDESTADDRREQ: return "Network error: Destination address required";
	122	case WSAEFAULT: return "Network error: Bad address";
	123	case WSAEHOSTDOWN: return "Network error: Host is down";
	124	case WSAEHOSTUNREACH: return "Network error: No route to host";
	125	case WSAEINPROGRESS: return "Network error: Operation now in progress";
	126	case WSAEINTR: return "Network error: Interrupted function call";
	127	case WSAEINVAL: return "Network error: Invalid argument";
	128	case WSAEISCONN: return "Network error: Socket is already connected";
	129	case WSAEMFILE: return "Network error: Too many open files";
	130	case WSAEMSGSIZE: return "Network error: Message too long";
	131	case WSAENETDOWN: return "Network error: Network is down";
	132	case WSAENETRESET: return "Network error: Network dropped connection on reset";
	133	case WSAENETUNREACH: return "Network error: Network is unreachable";
	134	case WSAENOBUFS: return "Network error: No buffer space available";
	135	case WSAENOPROTOOPT: return "Network error: Bad protocol option";
	136	case WSAENOTCONN: return "Network error: Socket is not connected";
	137	case WSAENOTSOCK: return "Network error: Socket operation on non-socket";
	138	case WSAEOPNOTSUPP: return "Network error: Operation not supported";
	139	case WSAEPFNOSUPPORT: return "Network error: Protocol family not supported";
	140	case WSAEPROCLIM: return "Network error: Too many processes";
	141	case WSAEPROTONOSUPPORT: return "Network error: Protocol not supported";
	142	case WSAEPROTOTYPE: return "Network error: Protocol wrong type for socket";
	143	case WSAESHUTDOWN: return "Network error: Cannot send after socket shutdown";
	144	case WSAESOCKTNOSUPPORT: return "Network error: Socket type not supported";
	145	case WSAETIMEDOUT: return "Network error: Connection timed out";
	146	case WSAEWOULDBLOCK: return "Network error: Resource temporarily unavailable";
	147	case WSAEDISCON: return "Network error: Graceful shutdown in progress";
	148	default: return "Unknown network error";
	149	}
	150	}
	151
c4d8e107	152	SockAddr sk_namelookup(char host, char *canonicalname)
c4d8e107	153	{
2f75bae1	154	SockAddr ret = smalloc(sizeof(struct SockAddr_tag));
2f75bae1	155	unsigned long a;
c4d8e107	156	struct hostent *h = NULL;
2f75bae1	157
c4d8e107	158	/* Clear the structure and default to IPv4. */
	159	memset(ret, 0, sizeof(struct SockAddr_tag));
	160	ret->family = 0; /* We set this one when we have resolved the host. */
	161	canonicalname = ret->realhost; / This makes sure we always have a hostname to return. */
	162
	163	if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE)
	164	{
	165	#ifdef IPV6
	166
	167	/* Try to get the getaddrinfo() function from wship6.dll */
	168	/* This way one doesn't need to have IPv6 dll's to use PuTTY and
	169	* it will fallback to IPv4. */
	170	typedef int (CALLBACK* FGETADDRINFO)(const char *nodename,
	171	const char *servname,
	172	const struct addrinfo *hints,
	173	struct addrinfo **res);
	174	FGETADDRINFO fGetAddrInfo = NULL;
	175
	176	HINSTANCE dllWSHIP6 = LoadLibrary("wship6.dll");
	177	if (dllWSHIP6)
	178	fGetAddrInfo = (FGETADDRINFO)GetProcAddress(dllWSHIP6,
	179	"getaddrinfo");
	180
	181	/*
	182	* Use fGetAddrInfo when it's available (which usually also
	183	* means IPv6 is installed...)
	184	*/
	185	if (fGetAddrInfo)
	186	{
	187	/debug(("Resolving \"%s\" with getaddrinfo() (IPv4+IPv6 capable)...\n", host)); /
	188	if (fGetAddrInfo(host, NULL, NULL, &ret->ai) == 0)
	189	ret->family = ret->ai->ai_family;
	190	}
	191	else
	192	#endif
	193	/*
	194	* Otherwise use the IPv4-only gethostbyname...
	195	* (NOTE: we don't use gethostbyname as a
	196	* fallback!)
	197	*/
	198	if (ret->family == 0)
	199	{
	200	/debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); /
	201	if (h = gethostbyname(host)) ret->family = AF_INET;
	202	}
	203	/debug(("Done resolving...(family is %d) AF_INET = %d, AF_INET6 = %d\n", ret->family, AF_INET, AF_INET6)); /
	204
	205	if (ret->family == 0)
	206	{
2f75bae1	207	DWORD err = WSAGetLastError();
c4d8e107	208	ret->error = (err == WSAENETDOWN ? "Network is down" :
	209	err == WSAHOST_NOT_FOUND ? "Host does not exist" :
	210	err == WSATRY_AGAIN ? "Host not found" :
	211	#ifdef IPV6
	212	fGetAddrInfo ? "getaddrinfo: unknown error" :
	213	#endif
	214	"gethostbyname: unknown error");
	215	#ifdef DEBUG
	216	{
	217	LPVOID lpMsgBuf;
	218	FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER \| FORMAT_MESSAGE_FROM_SYSTEM \| FORMAT_MESSAGE_IGNORE_INSERTS, NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR)&lpMsgBuf, 0, NULL);
bc51302a	219	/debug(("Error %ld: %s (h=%lx)\n", err, lpMsgBuf, h));/
c4d8e107	220	/* Free the buffer. */
	221	LocalFree(lpMsgBuf);
	222	}
	223	#endif
2f75bae1	224	}
c4d8e107	225	else
	226	{
	227	ret->error = NULL;
	228
	229	#ifdef IPV6
	230	/* If we got an address info use that... */
	231	if (ret->ai)
	232	{
	233	typedef int (CALLBACK* FGETNAMEINFO)
	234	(const struct sockaddr FAR *sa, socklen_t salen,
	235	char FAR * host, size_t hostlen, char FAR * serv,
	236	size_t servlen, int flags);
	237	FGETNAMEINFO fGetNameInfo = NULL;
	238
	239	/* Are we in IPv4 fallback mode? */
	240	/* We put the IPv4 address into the a variable so we can further-on use the IPv4 code... */
	241	if (ret->family == AF_INET)
	242	memcpy(&a, (char )&((SOCKADDR_IN )ret->ai->ai_addr)->sin_addr, sizeof(a));
	243
	244	/* Now let's find that canonicalname... */
	245	if ((dllWSHIP6) && (fGetNameInfo = (FGETNAMEINFO)GetProcAddress(dllWSHIP6, "getnameinfo")))
	246	{
	247	if (fGetNameInfo((struct sockaddr *)ret->ai->ai_addr,
	248	ret->family == AF_INET ?
	249	sizeof(SOCKADDR_IN) :
	250	sizeof(SOCKADDR_IN6), ret->realhost,
	251	sizeof(ret->realhost), NULL,
	252	0, 0) != 0)
	253	{
	254	strncpy(ret->realhost, host,
	255	sizeof(ret->realhost));
	256	}
	257	}
	258	}
	259	/* We used the IPv4-only gethostbyname()... */
	260	else
	261	{
	262	#endif
	263	memcpy(&a, h->h_addr, sizeof(a));
	264	/* This way we are always sure the h->h_name is valid :) */
	265	strncpy(ret->realhost, h->h_name, sizeof(ret->realhost));
	266	#ifdef IPV6
	267	}
	268	#endif
	269	}
	270	#ifdef IPV6
	271	FreeLibrary(dllWSHIP6);
	272	#endif
	273	}
	274	else
	275	{
9d47d0ea	276	/*
	277	* Hack inserted to deal with problems with numeric IPs.
	278	* FIXME: how will this work in IPv6?
	279	*/
	280	ret->family = AF_INET;
2f75bae1	281	*canonicalname = host;
	282	}
	283	ret->address = ntohl(a);
2f75bae1	284	return ret;
	285	}
	286
	287	void sk_addr_free(SockAddr addr) {
	288	sfree(addr);
	289	}
	290
c91409da	291	Socket sk_new(SockAddr addr, int port, int privport, sk_receiver_t receiver) {
2f75bae1	292	SOCKET s;
c4d8e107	293	#ifdef IPV6
	294	SOCKADDR_IN6 a6;
	295	#endif
2f75bae1	296	SOCKADDR_IN a;
	297	DWORD err;
	298	char *errstr;
	299	Socket ret;
	300	extern char *do_select(SOCKET skt, int startup);
c91409da	301	short localport;
2f75bae1	302
	303	/*
	304	* Create Socket structure.
	305	*/
	306	ret = smalloc(sizeof(struct Socket_tag));
	307	ret->error = NULL;
	308	ret->receiver = receiver;
	309	ret->head = ret->tail = NULL;
	310	ret->writable = 1; /* to start with */
	311	ret->in_oob = FALSE;
33232c8f	312	ret->sending_oob = 0;
2f75bae1	313
	314	/*
	315	* Open socket.
	316	*/
c4d8e107	317	s = socket(addr->family, SOCK_STREAM, 0);
2f75bae1	318	ret->s = s;
	319
	320	if (s == INVALID_SOCKET) {
	321	err = WSAGetLastError();
e74fbad9	322	ret->error = winsock_error_string(err);
2f75bae1	323	return ret;
	324	}
	325
	326	/*
	327	* Bind to local address.
	328	*/
c91409da	329	if (privport)
c91409da	330	localport = 1023; /* count from 1023 downwards */
c4d8e107	331	else
c91409da	332	localport = 0; /* just use port 0 (ie winsock picks) */
	333
	334	/* Loop round trying to bind */
	335	while (1) {
	336	int retcode;
	337
	338	#ifdef IPV6
	339	if (addr->family == AF_INET6)
	340	{
	341	memset(&a6,0,sizeof(a6));
	342	a6.sin6_family = AF_INET6;
	343	/a6.sin6_addr = in6addr_any;/ /* == 0 */
	344	a6.sin6_port = htons(localport);
	345	}
	346	else
	347	{
c4d8e107	348	#endif
c91409da	349	a.sin_family = AF_INET;
	350	a.sin_addr.s_addr = htonl(INADDR_ANY);
	351	a.sin_port = htons(localport);
c4d8e107	352	#ifdef IPV6
c91409da	353	}
	354	retcode = bind (s, (addr->family == AF_INET6 ?
	355	(struct sockaddr *)&a6 :
	356	(struct sockaddr *)&a),
	357	(addr->family == AF_INET6 ? sizeof(a6) : sizeof(a)));
c4d8e107	358	#else
c91409da	359	retcode = bind (s, (struct sockaddr *)&a, sizeof(a));
c4d8e107	360	#endif
c91409da	361	if (retcode != SOCKET_ERROR) {
	362	err = 0;
	363	break; /* done */
	364	} else {
	365	err = WSAGetLastError();
	366	if (err != WSAEADDRINUSE) /* failed, for a bad reason */
	367	break;
	368	}
	369
	370	if (localport == 0)
	371	break; /* we're only looping once */
	372	localport--;
	373	if (localport == 0)
	374	break; /* we might have got to the end */
	375	}
	376
	377	if (err)
c4d8e107	378	{
c4d8e107	379	ret->error = winsock_error_string(err);
2f75bae1	380	return ret;
	381	}
	382
	383	/*
	384	* Connect to remote address.
	385	*/
c4d8e107	386	#ifdef IPV6
	387	if (addr->family == AF_INET6)
	388	{
	389	memset(&a,0,sizeof(a));
	390	a6.sin6_family = AF_INET6;
	391	a6.sin6_port = htons((short)port);
	392	a6.sin6_addr = ((struct sockaddr_in6 *)addr->ai->ai_addr)->sin6_addr;
	393	}
	394	else
	395	{
	396	#endif
	397	a.sin_family = AF_INET;
	398	a.sin_addr.s_addr = htonl(addr->address);
	399	a.sin_port = htons((short)port);
	400	#ifdef IPV6
	401	}
	402	if (connect (s, (addr->family == AF_INET6) ? (struct sockaddr )&a6 : (struct sockaddr )&a, (addr->family == AF_INET6) ? sizeof(a6) : sizeof(a)) == SOCKET_ERROR)
	403	#else
	404	if (connect (s, (struct sockaddr *)&a, sizeof(a)) == SOCKET_ERROR)
	405	#endif
	406	{
2f75bae1	407	err = WSAGetLastError();
c4d8e107	408	ret->error = winsock_error_string(err);
2f75bae1	409	return ret;
	410	}
	411
	412	/* Set up a select mechanism. This could be an AsyncSelect on a
	413	* window, or an EventSelect on an event object. */
	414	errstr = do_select(s, 1);
	415	if (errstr) {
	416	ret->error = errstr;
	417	return ret;
	418	}
	419
	420	add234(sktree, ret);
	421
	422	return ret;
	423	}
	424
	425	void sk_close(Socket s) {
9c964e85	426	extern char *do_select(SOCKET skt, int startup);
9c964e85	427
2f75bae1	428	del234(sktree, s);
	429	do_select(s->s, 0);
	430	closesocket(s->s);
dcbde236	431	sfree(s);
2f75bae1	432	}
2f75bae1	433
2f75bae1	434	/*
	435	* The function which tries to send on a socket once it's deemed
	436	* writable.
	437	*/
	438	void try_send(Socket s) {
	439	while (s->head) {
	440	int nsent;
	441	DWORD err;
	442	int len, urgentflag;
	443
	444	if (s->sending_oob) {
	445	urgentflag = MSG_OOB;
	446	len = s->sending_oob;
	447	} else {
	448	urgentflag = 0;
	449	len = s->head->buflen - s->head->bufpos;
	450	}
	451
	452	nsent = send(s->s, s->head->buf + s->head->bufpos, len, urgentflag);
7d6ee6ff	453	noise_ultralight(nsent);
2f75bae1	454	if (nsent <= 0) {
	455	err = (nsent < 0 ? WSAGetLastError() : 0);
	456	if (err == WSAEWOULDBLOCK) {
	457	/* Perfectly normal: we've sent all we can for the moment. */
	458	s->writable = FALSE;
	459	return;
	460	} else if (nsent == 0 \|\|
	461	err == WSAECONNABORTED \|\|
	462	err == WSAECONNRESET) {
	463	/*
	464	* FIXME. This will have to be done better when we
	465	* start managing multiple sockets (e.g. SSH port
	466	* forwarding), because if we get CONNRESET while
	467	* trying to write a particular forwarded socket
	468	* then it isn't necessarily the end of the world.
	469	* Ideally I'd like to pass the error code back to
	470	* somewhere the next select_result() will see it,
	471	* but that might be hard. Perhaps I should pass it
	472	* back to be queued in the Windows front end bit.
	473	*/
	474	fatalbox(winsock_error_string(err));
	475	} else {
	476	fatalbox(winsock_error_string(err));
	477	}
	478	} else {
	479	s->head->bufpos += nsent;
	480	if (s->sending_oob)
	481	s->sending_oob -= nsent;
	482	if (s->head->bufpos >= s->head->buflen) {
	483	struct buffer *tmp = s->head;
	484	s->head = tmp->next;
dcbde236	485	sfree(tmp);
2f75bae1	486	if (!s->head)
	487	s->tail = NULL;
	488	}
	489	}
	490	}
	491	}
	492
	493	void sk_write(Socket s, char *buf, int len) {
	494	/*
	495	* Add the data to the buffer list on the socket.
	496	*/
	497	if (s->tail && s->tail->buflen < BUFFER_GRANULE) {
	498	int copylen = min(len, BUFFER_GRANULE - s->tail->buflen);
	499	memcpy(s->tail->buf + s->tail->buflen, buf, copylen);
	500	buf += copylen;
	501	len -= copylen;
	502	s->tail->buflen += copylen;
	503	}
	504	while (len > 0) {
	505	int grainlen = min(len, BUFFER_GRANULE);
	506	struct buffer *newbuf;
	507	newbuf = smalloc(sizeof(struct buffer));
	508	newbuf->bufpos = 0;
	509	newbuf->buflen = grainlen;
	510	memcpy(newbuf->buf, buf, grainlen);
	511	buf += grainlen;
	512	len -= grainlen;
	513	if (s->tail)
	514	s->tail->next = newbuf;
	515	else
	516	s->head = s->tail = newbuf;
	517	newbuf->next = NULL;
	518	s->tail = newbuf;
	519	}
	520
	521	/*
	522	* Now try sending from the start of the buffer list.
	523	*/
	524	if (s->writable)
	525	try_send(s);
	526	}
	527
	528	void sk_write_oob(Socket s, char *buf, int len) {
	529	/*
	530	* Replace the buffer list on the socket with the data.
	531	*/
	532	if (!s->head) {
	533	s->head = smalloc(sizeof(struct buffer));
	534	} else {
	535	struct buffer *walk = s->head->next;
	536	while (walk) {
	537	struct buffer *tmp = walk;
	538	walk = tmp->next;
dcbde236	539	sfree(tmp);
2f75bae1	540	}
	541	}
	542	s->head->next = NULL;
	543	s->tail = s->head;
	544	s->head->buflen = len;
	545	memcpy(s->head->buf, buf, len);
	546
	547	/*
	548	* Set the Urgent marker.
	549	*/
	550	s->sending_oob = len;
	551
	552	/*
	553	* Now try sending from the start of the buffer list.
	554	*/
	555	if (s->writable)
	556	try_send(s);
	557	}
	558
	559	int select_result(WPARAM wParam, LPARAM lParam) {
	560	int ret;
	561	DWORD err;
	562	char buf[BUFFER_GRANULE];
	563	Socket s;
49bad831	564	u_long atmark;
2f75bae1	565
	566	/* wParam is the socket itself */
	567	s = find234(sktree, (void *)wParam, cmpforsearch);
	568	if (!s)
	569	return 1; /* boggle */
	570
	571	if ((err = WSAGETSELECTERROR(lParam)) != 0) {
2c94fd1c	572	/*
	573	* An error has occurred on this socket. Pass it to the
	574	* receiver function.
	575	*/
	576	return s->receiver(s, 3, winsock_error_string(err), err);
2f75bae1	577	}
2f75bae1	578
7d6ee6ff	579	noise_ultralight(lParam);
7d6ee6ff	580
2f75bae1	581	switch (WSAGETSELECTEVENT(lParam)) {
	582	case FD_READ:
	583	ret = recv(s->s, buf, sizeof(buf), 0);
	584	if (ret < 0) {
	585	err = WSAGetLastError();
	586	if (err == WSAEWOULDBLOCK) {
	587	break;
	588	}
	589	}
	590	if (ret < 0) {
2c94fd1c	591	return s->receiver(s, 3, winsock_error_string(err), err);
2f75bae1	592	} else {
	593	int type = s->in_oob ? 2 : 0;
	594	s->in_oob = FALSE;
	595	return s->receiver(s, type, buf, ret);
	596	}
	597	break;
	598	case FD_OOB:
	599	/*
	600	* Read all data up to the OOB marker, and send it to the
	601	* receiver with urgent==1 (OOB pending).
	602	*/
	603	atmark = 1;
	604	s->in_oob = TRUE;
	605	/* Some WinSock wrappers don't support this call, so we
	606	* deliberately don't check the return value. If the call
	607	* fails and does nothing, we will get back atmark==1,
	608	* which is good enough to keep going at least. */
	609	ioctlsocket(s->s, SIOCATMARK, &atmark);
	610	ret = recv(s->s, buf, sizeof(buf), MSG_OOB);
7d6ee6ff	611	noise_ultralight(ret);
2f75bae1	612	if (ret <= 0) {
	613	fatalbox(ret == 0 ? "Internal networking trouble" :
	614	winsock_error_string(WSAGetLastError()));
	615	} else {
	616	return s->receiver(s, atmark ? 2 : 1, buf, ret);
	617	}
	618	break;
	619	case FD_WRITE:
	620	s->writable = 1;
	621	try_send(s);
	622	break;
	623	case FD_CLOSE:
	624	/* Signal a close on the socket. */
	625	return s->receiver(s, 0, NULL, 0);
	626	break;
	627	}
	628
	629	return 1;
	630	}
	631
	632	/*
	633	* Each socket abstraction contains a `void *' private field in
	634	* which the client can keep state.
	635	*/
	636	void sk_set_private_ptr(Socket s, void *ptr) {
	637	s->private_ptr = ptr;
	638	}
	639	void *sk_get_private_ptr(Socket s) {
	640	return s->private_ptr;
	641	}
	642
	643	/*
	644	* Special error values are returned from sk_namelookup and sk_new
	645	* if there's a problem. These functions extract an error message,
	646	* or return NULL if there's no problem.
	647	*/
	648	char *sk_addr_error(SockAddr addr) {
	649	return addr->error;
	650	}
	651	char *sk_socket_error(Socket s) {
	652	return s->error;
	653	}
	654
	655	/*
	656	* For Plink: enumerate all sockets currently active.
	657	*/
	658	SOCKET first_socket(enum234 *e) {
	659	Socket s = first234(sktree, e);
	660	return s ? s->s : INVALID_SOCKET;
	661	}
	662	SOCKET next_socket(enum234 *e) {
	663	Socket s = next234(e);
	664	return s ? s->s : INVALID_SOCKET;
	665	}