/*
 * Copyright (c) 2003 Ben Harris
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
/*
 * mtcpnet.c - MacTCP interface
 */

#if !TARGET_API_MAC_CARBON

#include <MacTypes.h>
#include <Devices.h>
#include <Endian.h>
#include <Folders.h>
#include <MacTCP.h>
#include <MixedMode.h>
#include <Resources.h>

#include <assert.h>

#define DEFINE_PLUG_METHOD_MACROS
#include "putty.h"
#include "network.h"
#include "mac.h"

/*
 * The following structures are documented as being in
 * <AddressXlation.h>, but that isn't shipped with Universal
 * Interfaces, and it's easier to define them here than to require
 * people to download yet another SDK.
 */

static OSErr OpenResolver(char *);
static OSErr CloseResolver(void);

enum {
    OPENRESOLVER = 1,
    CLOSERESOLVER,
    STRTOADDR,
    ADDRTOSTR,
    ENUMCACHE,
    ADDRTONAME,
    HXINFO,
    MXINFO
};

#define NUM_ALT_ADDRS 4

typedef struct hostInfo {
    int rtnCode;
    char cname[255];
    unsigned long addr[NUM_ALT_ADDRS];
};

typedef CALLBACK_API(void, ResultProcPtr)(struct hostInfo *, char *);
typedef STACK_UPP_TYPE(ResultProcPtr) ResultUPP;
enum { uppResultProcInfo = kPascalStackBased
       | STACK_ROUTINE_PARAMETER(1, SIZE_CODE(sizeof(struct hostInfo*)))
       | STACK_ROUTINE_PARAMETER(2, SIZE_CODE(sizeof(char *)))
};
#define NewResultUPP(userRoutine)					\
    (ResultUPP)NewRoutineDescriptor((ProcPtr)(userRoutine),		\
				    uppResultProcInfo,			\
				    GetCurrentArchitecture())
#define DisposeResultUPP(userUPP) DisposeRoutineDescriptor(userUPP)

static OSErr StrToAddr(char *, struct hostInfo *, ResultUPP *, char *);

typedef CALLBACK_API_C(OSErr, OpenResolverProcPtr)(UInt32, char *);
typedef STACK_UPP_TYPE(OpenResolverProcPtr) OpenResolverUPP;
enum { uppOpenResolverProcInfo = kCStackBased
       | RESULT_SIZE(SIZE_CODE(sizeof(OSErr)))
       | STACK_ROUTINE_PARAMETER(1, SIZE_CODE(sizeof(UInt32)))
       | STACK_ROUTINE_PARAMETER(2, SIZE_CODE(sizeof(char*)))
};
#define InvokeOpenResolverUPP(selector, fileName, userUPP)		\
    CALL_TWO_PARAMETER_UPP((userUPP), uppOpenResolverProcInfo,		\
			   (selector), (fileName))

typedef CALLBACK_API_C(OSErr, CloseResolverProcPtr)(UInt32);
typedef STACK_UPP_TYPE(CloseResolverProcPtr) CloseResolverUPP;
enum { uppCloseResolverProcInfo = kCStackBased
       | RESULT_SIZE(SIZE_CODE(sizeof(OSErr)))
       | STACK_ROUTINE_PARAMETER(1, SIZE_CODE(sizeof(UInt32)))
};
#define InvokeCloseResolverUPP(selector, userUPP)			\
    CALL_ONE_PARAMETER_UPP((userUPP), uppCloseResolverProcInfo, (selector))

typedef CALLBACK_API_C(OSErr, StrToAddrProcPtr)(UInt32, char *,
						struct hostInfo *, ResultUPP,
						char *);
typedef STACK_UPP_TYPE(StrToAddrProcPtr) StrToAddrUPP;
enum { uppStrToAddrProcInfo = kCStackBased
       | RESULT_SIZE(SIZE_CODE(sizeof(OSErr)))
       | STACK_ROUTINE_PARAMETER(1, SIZE_CODE(sizeof(UInt32)))
       | STACK_ROUTINE_PARAMETER(2, SIZE_CODE(sizeof(char *)))
       | STACK_ROUTINE_PARAMETER(3, SIZE_CODE(sizeof(struct hostInfo *)))
       | STACK_ROUTINE_PARAMETER(4, SIZE_CODE(sizeof(ResultUPP)))
       | STACK_ROUTINE_PARAMETER(5, SIZE_CODE(sizeof(char *)))
};
#define InvokeStrToAddrUPP(selector, hostName, hostInfoPtr, ResultProc,	\
			   userDataPtr, userUPP)			\
    CALL_FIVE_PARAMETER_UPP((userUPP), uppStrToAddrProcInfo, (selector),\
			    (hostName), (hostInfoPtr), (ResultProc),	\
			    (userDataPtr))
#define StrToAddr(hostName, hostInfoPtr, ResultProc, userDataPtr)	\
    InvokeStrToAddrUPP(STRTOADDR, hostName, hostInfoPtr, ResultProc,	\
		       userDataPtr, (StrToAddrUPP)*mactcp.dnr_handle)

typedef CALLBACK_API_C(OSErr, AddrToStrProcPtr)(UInt32, unsigned long, char *);
typedef STACK_UPP_TYPE(AddrToStrProcPtr) AddrToStrUPP;
enum { uppAddrToStrProcInfo = kCStackBased
       | RESULT_SIZE(SIZE_CODE(sizeof(OSErr)))
       | STACK_ROUTINE_PARAMETER(1, SIZE_CODE(sizeof(UInt32)))
       | STACK_ROUTINE_PARAMETER(2, SIZE_CODE(sizeof(unsigned long)))
       | STACK_ROUTINE_PARAMETER(3, SIZE_CODE(sizeof(char *)))
};
#define InvokeAddrToStrUPP(selector, addr, addrStr, userUPP)		\
    CALL_THREE_PARAMETER_UPP((userUPP), uppAddrToStrProcInfo, (selector),\
			     (addr), (addrStr))
#define AddrToStr(addr, addrStr)					\
    InvokeAddrToStrUPP(ADDRTOSTR, addr, addrStr,			\
		       (AddrToStrUPP)*mactcp.dnr_handle)

/* End of AddressXlation.h bits */

/* TCP connection states, mysteriously missing from <MacTCP.h> */
#define TCPS_CLOSED		0
#define TCPS_LISTEN		2
#define TCPS_SYN_RECEIVED	4
#define TCPS_SYN_SENT		6
#define TCPS_ESTABLISHED	8
#define TCPS_FIN_WAIT_1		10
#define TCPS_FIN_WAIT_2		12
#define TCPS_CLOSE_WAIT		14
#define TCPS_CLOSING		16
#define TCPS_LAST_ACK		18
#define TCPS_TIME_WAIT		20

struct Socket_tag {
    struct socket_function_table *fn;
    /* the above variable absolutely *must* be the first in this structure */
    StreamPtr s;
    OSErr err;
    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 oobpending;		       /* is there OOB data available to read? */
    int oobinline;
    int pending_error;		       /* in case send() returns error */
    int listener;
    struct Socket_tag *next;
    struct Socket_tag **prev;
};

/*
 * 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 {
    int resolved;
    struct hostInfo hostinfo;
    char hostname[512];
};

/* Global variables */
static struct {
    Handle dnr_handle;
    int initialised;
    short refnum;
    ProcessSerialNumber self;
    Actual_Socket socklist;
} mactcp;

static pascal void mactcp_lookupdone(struct hostInfo *hi, char *cookie);
static pascal void mactcp_asr(StreamPtr, unsigned short, Ptr, unsigned short,
			      struct ICMPReport *);
static Plug mactcp_plug(Socket, Plug);
static void mactcp_flush(Socket);
static void mactcp_close(Socket);
static int mactcp_write(Socket, char const *, int);
static int mactcp_write_oob(Socket, char const*, int);
static void mactcp_set_private_ptr(Socket, void *);
static void *mactcp_get_private_ptr(Socket);
static const char *mactcp_socket_error(Socket);
static void mactcp_set_frozen(Socket, int);

static void mactcp_recv(Actual_Socket s, size_t len);

/*
 * Initialise MacTCP.
 * This should be called once before any TCP connection is opened.
 */

OSErr mactcp_init(void)
{
    OSErr err;

    /*
     * IM:Devices describes a convoluted way of finding a spare unit
     * number to open a driver on before calling OpenDriver.  Happily,
     * the MacTCP INIT ensures that .IPP is already open (and hence
     * has a valid unit number already) so we don't need to go through
     * all that.  (MacTCP Programmer's Guide p6)
     */
    err = OpenDriver("\p.IPP", &mactcp.refnum);
    if (err != noErr) return err;
    err = OpenResolver(NULL);
    if (err != noErr) return err;

    mactcp.initialised = TRUE;
    return noErr;
}

void mactcp_cleanup(void)
{
    Actual_Socket s, next;

    /*
     * Eventually, PuTTY should close down each session as it exits,
     * so there should be no sockets left when we get here.  Still,
     * better safe than sorry.
     *
     * XXX What about in-flight aync I/O (when we support that)?
     */
    for (s = mactcp.socklist; s != NULL; s = next) {
	next = s->next; /* s is about to vanish */
	mactcp_close(&s->fn);
    }

    /*
     * When we get async DNS, we have to wait for any outstanding
     * requests to complete here before exiting.
     */
    CloseResolver();
    mactcp.initialised = FALSE;
}

static ResultUPP mactcp_lookupdone_upp;

SockAddr mactcp_namelookup(char const *host, char **canonicalname)
{
    SockAddr ret = snew(struct SockAddr_tag);
    OSErr err;
    volatile int done = FALSE;
    char *realhost;
    int realhostlen;

    /* Clear the structure. */
    memset(ret, 0, sizeof(struct SockAddr_tag));
    if (mactcp_lookupdone_upp == NULL)
	mactcp_lookupdone_upp = NewResultUPP(&mactcp_lookupdone);
    /* Casting away const -- hope StrToAddr is sensible */
    err = StrToAddr((char *)host, &ret->hostinfo, mactcp_lookupdone_upp,
		    (char *)&done);
    /*
     * PuTTY expects DNS lookups to be synchronous (see bug
     * "async-dns"), so we pretend they are.
     */
    if (err == cacheFault)
	while (!done)
	    continue;
    ret->resolved = TRUE;
    
    if (ret->hostinfo.rtnCode == noErr) {
	realhost = ret->hostinfo.cname;
	/* MacTCP puts trailing dots on canonical names. */
	realhostlen = strlen(realhost);
	if (realhost[realhostlen - 1] == '.')
	    realhost[realhostlen - 1] = '\0';
    } else
	realhost = "";
    *canonicalname = snewn(1 + strlen(realhost), char);
    strcpy(*canonicalname, realhost);
    return ret;
}

static pascal void mactcp_lookupdone(struct hostInfo *hi, char *cookie)
{
    volatile int *donep = (int *)cookie;

    *donep = TRUE;
}

SockAddr mactcp_nonamelookup(char const *host)
{
    SockAddr ret = snew(struct SockAddr_tag);

    ret->resolved = FALSE;
    ret->hostinfo.rtnCode = noErr;
    ret->hostname[0] = '\0';
    strncat(ret->hostname, host, lenof(ret->hostname) - 1);
    return ret;
}

void mactcp_getaddr(SockAddr addr, char *buf, int buflen)
{
    char mybuf[16];
    OSErr err;

    if (addr->resolved) {
	/* XXX only return first address */
	err = AddrToStr(addr->hostinfo.addr[0], mybuf);
	buf[0] = '\0';
	if (err != noErr)
	    strncat(buf, mybuf, buflen - 1);
    } else {
	buf[0] = '\0';
	strncat(buf, addr->hostname, buflen - 1);
    }
}

/* I think "local" here really means "loopback" */

int mactcp_hostname_is_local(char *name)
{

    return !strcmp(name, "localhost");
}

int mactcp_address_is_local(SockAddr addr)
{
    int i;

    if (addr->resolved)
	for (i = 0; i < NUM_ALT_ADDRS; i++)
	    if (addr->hostinfo.addr[i] & 0xff000000 == 0x7f000000)
		return TRUE;
    return FALSE;
}

int mactcp_addrtype(SockAddr addr)
{

    if (addr->resolved)
	return ADDRTYPE_IPV4;
    return ADDRTYPE_NAME;
}

void mactcp_addrcopy(SockAddr addr, char *buf)
{

    /* XXX only return first address */
    memcpy(buf, &addr->hostinfo.addr[0], 4);
}

void mactcp_addr_free(SockAddr addr)
{

    sfree(addr);
}

static Plug mactcp_plug(Socket sock, Plug p)
{
    Actual_Socket s = (Actual_Socket) sock;
    Plug ret = s->plug;

    if (p)
	s->plug = p;
    return ret;
}

static void mactcp_flush(Socket s)
{

    fatalbox("mactcp_flush");
}

Socket mactcp_register(void *sock, Plug plug)
{

    fatalbox("mactcp_register");
}

static TCPNotifyUPP mactcp_asr_upp;

Socket mactcp_new(SockAddr addr, int port, int privport, int oobinline,
	      int nodelay, int keepalive, Plug plug)
{
    static struct socket_function_table fn_table = {
	mactcp_plug,
	mactcp_close,
	mactcp_write,
	mactcp_write_oob,
	mactcp_flush,
	mactcp_set_private_ptr,
	mactcp_get_private_ptr,