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/*

 * sock.c -- Posix Socket upper layer support module for general posix use

 *

 * Copyright (c) GoAhead Software Inc., 1995-2000. All Rights Reserved.

 */

/******************************** Description *********************************/

/*

 *      Posix Socket Module.  This supports blocking and non-blocking buffered

 *      socket I/O.

 */

/********************************** Includes **********************************/

#include        <string.h>

#include        <stdlib.h>

#if UEMF

        #include        "uemf.h"

#else

        #include        <socket.h>

        #include        <types.h>

        #include        <unistd.h>

        #include        "emfInternal.h"

#endif

/************************************ Locals **********************************/

socket_t        **socketList;                   /* List of open sockets */

int                     socketMax;                              /* Maximum size of socket */

int                     socketHighestFd = -1;   /* Highest socket fd opened */

/***************************** Forward Declarations ***************************/

static int      socketDoOutput(socket_t *sp, char *buf, int toWrite, int *errCode);

static int      tryAlternateSendTo(int sock, char *buf, int toWrite, int i,

                        struct sockaddr *server);

/*********************************** Code *************************************/

/*

 *      Write to a socket. Absorb as much data as the socket can buffer. Block if

 *      the socket is in blocking mode. Returns -1 on error, otherwise the number

 *      of bytes written.

 */

int     socketWrite(int sid, char *buf, int bufsize)

{

        socket_t        *sp;

        ringq_t         *rq;

        int                     len, bytesWritten, room;

        a_assert(buf);

        a_assert(bufsize >= 0);

        if ((sp = socketPtr(sid)) == NULL) {

                return -1;

        }

/*

 *      Loop adding as much data to the output ringq as we can absorb. Initiate a

 *      flush when the ringq is too full and continue. Block in socketFlush if the

 *      socket is in blocking mode.

 */

        rq = &sp->outBuf;

        for (bytesWritten = 0; bufsize > 0; ) {

                if ((room = ringqPutBlkMax(rq)) == 0) {

                        if (socketFlush(sid) < 0) {

                                return -1;

                        }

                        if ((room = ringqPutBlkMax(rq)) == 0) {

                                if (sp->flags & SOCKET_BLOCK) {

#if WIN || CE

                                        int             errCode;

                                        if (! socketWaitForEvent(sp,  FD_WRITE | SOCKET_WRITABLE,

                                                &errCode)) {

                                                return -1;

                                        }

#endif

                                        continue;

                                }

                                break;

                        }

                        continue;

                }

                len = min(room, bufsize);

                ringqPutBlk(rq, (unsigned char *) buf, len);

                bytesWritten += len;

                bufsize -= len;

                buf += len;

        }

        return bytesWritten;

}

/******************************************************************************/

/*

 *      Write a string to a socket

 */

int     socketWriteString(int sid, char_t *buf)

{

 #if UNICODE

        char    *byteBuf;

        int             r, len;

        len = gstrlen(buf);

        byteBuf = ballocUniToAsc(buf, len);

        r = socketWrite(sid, byteBuf, len);

        bfreeSafe(B_L, byteBuf);

        return r;

 #else

        return socketWrite(sid, buf, strlen(buf));

 #endif /* UNICODE */

}

/******************************************************************************/

/*

 *      Read from a socket. Return the number of bytes read if successful. This

 *      may be less than the requested "bufsize" and may be zero. Return -1 for

 *      errors. Return 0 for EOF. Otherwise return the number of bytes read.

 *      If this routine returns zero it indicates an EOF condition.

 *  which can be verified with socketEof()

 *      Note: this ignores the line buffer, so a previous socketGets

 *      which read a partial line may cause a subsequent socketRead to miss some

 *      data. This routine may block if the socket is in blocking mode.

 *

 */

int     socketRead(int sid, char *buf, int bufsize)

{

        socket_t        *sp;

        ringq_t         *rq;

        int                     len, room, errCode, bytesRead;

        a_assert(buf);

        a_assert(bufsize > 0);

        if ((sp = socketPtr(sid)) == NULL) {

                return -1;

        }

        if (sp->flags & SOCKET_EOF) {

                return 0;

        }

        rq = &sp->inBuf;

        for (bytesRead = 0; bufsize > 0; ) {

                len = min(ringqLen(rq), bufsize);

                if (len <= 0) {

/*

 *                      if blocking mode and already have data, exit now or it may block

 *                      forever.

 */

                        if ((sp->flags & SOCKET_BLOCK) &&

                                (bytesRead > 0)) {

                                break;

                        }

/*

 *                      This flush is critical for readers of datagram packets. If the

 *                      buffer is not big enough to read the whole datagram in one hit,

 *                      the recvfrom call will fail.

 */

                        ringqFlush(rq);

                        room = ringqPutBlkMax(rq);

                        len = socketGetInput(sid, (char *) rq->endp, room, &errCode);

                        if (len < 0) {

                                if (errCode == EWOULDBLOCK) {

                                        if ((sp->flags & SOCKET_BLOCK) &&

                                                (bytesRead ==  0)) {

                                                continue;

                                        }

                                        if (bytesRead >= 0) {

                                                return bytesRead;

                                        }

                                }

                                return -1;

                        } else if (len == 0) {

/*

 *                              If bytesRead is 0, this is EOF since socketRead should never

 *                              be called unless there is data yet to be read.  Set the flag.

 *                              Then pass back the number of bytes read.

 */

                                if (bytesRead == 0) {

                                        sp->flags |= SOCKET_EOF;

                                }

                                return bytesRead;

                        }

                        ringqPutBlkAdj(rq, len);

                        len = min(len, bufsize);

                }

                memcpy(&buf[bytesRead], rq->servp, len);

                ringqGetBlkAdj(rq, len);

                bufsize -= len;

                bytesRead += len;

        }

        return bytesRead;

}

/******************************************************************************/

/*

 *      Get a string from a socket. This returns data in *buf in a malloced string

 *      after trimming the '\n'. If there is zero bytes returned, *buf will be set

 *      to NULL. If doing non-blocking I/O, it returns -1 for error, EOF or when

 *      no complete line yet read. If doing blocking I/O, it will block until an

 *      entire line is read. If a partial line is read socketInputBuffered or

 *      socketEof can be used to distinguish between EOF and partial line still

 *      buffered. This routine eats and ignores carriage returns.

 */

int     socketGets(int sid, char_t **buf)

{

        socket_t        *sp;

        ringq_t         *lq;

        char            c;

        int                     rc, len;

        a_assert(buf);

        *buf = NULL;

        if ((sp = socketPtr(sid)) == NULL) {

                return -1;

        }

        lq = &sp->lineBuf;

        while (1) {

                if ((rc = socketRead(sid, &c, 1)) < 0) {

                        return rc;

                }

                if (rc == 0) {

/*

 *                      If there is a partial line and we are at EOF, pretend we saw a '\n'

 */

                        if (ringqLen(lq) > 0 && (sp->flags & SOCKET_EOF)) {

                                c = '\n';

                        } else {

                                return -1;

                        }

                }

/*

 *              If a newline is seen, return the data excluding the new line to the

 *              caller. If carriage return is seen, just eat it.

 */

                if (c == '\n') {

                        len = ringqLen(lq);

                        if (len > 0) {

                                *buf = ballocAscToUni(lq->servp, len);

                        } else {

                                *buf = NULL;

                        }

                        ringqFlush(lq);

                        return len;

                } else if (c == '\r') {

                        continue;

                }

                ringqPutcA(lq, c);

        }

        return 0;

}

/******************************************************************************/

/*

 *      Flush the socket. Block if the socket is in blocking mode.

 *      This will return -1 on errors and 0 if successful.

 */

int socketFlush(int sid)

{

        socket_t        *sp;

        ringq_t         *rq;

        int                     len, bytesWritten, errCode;

        if ((sp = socketPtr(sid)) == NULL) {

                return -1;

        }

        rq = &sp->outBuf;

/*

 *      Set the background flushing flag which socketEventProc will check to

 *      continue the flush.

 */

        if (! (sp->flags & SOCKET_BLOCK)) {

                sp->flags |= SOCKET_FLUSHING;

        }

/*

 *      Break from loop if not blocking after initiating output. If we are blocking

 *      we wait for a write event.

 */

        while (ringqLen(rq) > 0) {

                len = ringqGetBlkMax(&sp->outBuf);

                bytesWritten = socketDoOutput(sp, (char*) rq->servp, len, &errCode);

                if (bytesWritten < 0) {

                        if (errCode == EINTR) {

                                continue;

                        } else if (errCode == EWOULDBLOCK || errCode == EAGAIN) {

#if WIN || CE

                                if (sp->flags & SOCKET_BLOCK) {

                                        int             errCode;

                                        if (! socketWaitForEvent(sp,  FD_WRITE | SOCKET_WRITABLE,

                                                &errCode)) {

                                                return -1;

                                        }

                                        continue;

                                }

#endif

/*

 *                              Ensure we get a FD_WRITE message when the socket can absorb

 *                              more data (non-blocking only.) Store the user's mask if we

 *                              haven't done it already.

 */

                                if (sp->saveMask < 0 ) {

                                        sp->saveMask = sp->handlerMask;

                                        socketRegisterInterest(sp,

                                        sp->handlerMask | SOCKET_WRITABLE);

                                }

                                return 0;

                        }

                        return -1;

                }

                ringqGetBlkAdj(rq, bytesWritten);

        }

/*

 *      If the buffer is empty, reset the ringq pointers to point to the start

 *      of the buffer. This is essential to ensure that datagrams get written

 *      in one single I/O operation.

 */

        if (ringqLen(rq) == 0) {

                ringqFlush(rq);

        }

/*

 *      Restore the users mask if it was saved by the non-blocking code above.

 *      Note: saveMask = -1 if empty. socketRegisterInterest will set handlerMask

 */

        if (sp->saveMask >= 0) {

                socketRegisterInterest(sp, sp->saveMask);

                sp->saveMask = -1;

        }

        sp->flags &= ~SOCKET_FLUSHING;

        return 0;

}

/******************************************************************************/

/*

 *      Return the count of input characters buffered. We look at both the line

 *      buffer and the input (raw) buffer. Return -1 on error or EOF.

 */

int socketInputBuffered(int sid)

{

        socket_t        *sp;

        if ((sp = socketPtr(sid)) == NULL) {

                return -1;

        }

        if (socketEof(sid)) {

                return -1;

        }

        return ringqLen(&sp->lineBuf) + ringqLen(&sp->inBuf);

}

/******************************************************************************/

/*

 *      Return true if EOF

 */

int socketEof(int sid)

{

        socket_t        *sp;

        if ((sp = socketPtr(sid)) == NULL) {

                return -1;

        }

        return sp->flags & SOCKET_EOF;

}

/******************************************************************************/

/*

 *      Return the number of bytes the socket can absorb without blocking

 */

int socketCanWrite(int sid)

{

        socket_t        *sp;

        if ((sp = socketPtr(sid)) == NULL) {

                return -1;

        }

        return sp->outBuf.buflen - ringqLen(&sp->outBuf) - 1;

}

/******************************************************************************/

/*

 *      Add one to allow the user to write exactly SOCKET_BUFSIZ

 */

void socketSetBufferSize(int sid, int in, int line, int out)

{

        socket_t        *sp;

        if ((sp = socketPtr(sid)) == NULL) {

                return;

        }

        if (in >= 0) {

                ringqClose(&sp->inBuf);

                in++;

                ringqOpen(&sp->inBuf, in, in);

        }

        if (line >= 0) {

                ringqClose(&sp->lineBuf);

                line++;

                ringqOpen(&sp->lineBuf, line, line);

        }

        if (out >= 0) {

                ringqClose(&sp->outBuf);

                out++;

                ringqOpen(&sp->outBuf, out, out);

        }

}

/******************************************************************************/

/*

 *      Create a user handler for this socket. The handler called whenever there

 *      is an event of interest as defined by handlerMask (SOCKET_READABLE, ...)

 */

void socketCreateHandler(int sid, int handlerMask, socketHandler_t handler,

                int data)

{

        socket_t        *sp;

        if ((sp = socketPtr(sid)) == NULL) {

                return;

        }

        sp->handler = handler;

        sp->handler_data = data;

        socketRegisterInterest(sp, handlerMask);

}

/******************************************************************************/

/*

 *      Delete a handler

 */

void socketDeleteHandler(int sid)

{

        socket_t        *sp;

        if ((sp = socketPtr(sid)) == NULL) {

                return;

        }

        sp->handler = NULL;

        socketRegisterInterest(sp, 0);

}

/******************************************************************************/

/*

 *      Socket output procedure. Return -1 on errors otherwise return the number

 *      of bytes written.

 */

static int socketDoOutput(socket_t *sp, char *buf, int toWrite, int *errCode)

{

        struct sockaddr_in      server;

        int                                     bytes;

        a_assert(sp);

        a_assert(buf);

        a_assert(toWrite > 0);

        a_assert(errCode);

        *errCode = 0;

#if WIN || CE

        if ((sp->flags & SOCKET_ASYNC)

                        && ! socketWaitForEvent(sp,  FD_CONNECT, errCode)) {

                return -1;

        }

#endif

/*

 *      Write the data

 */

        if (sp->flags & SOCKET_BROADCAST) {

                server.sin_family = AF_INET;

#if UEMF || LITTLEFOOT

                server.sin_addr.s_addr = INADDR_BROADCAST;

#else

                server.sin_addr.s_addr = inet_addr(basicGetBroadcastAddress());

#endif

                server.sin_port = htons((short)(sp->port & 0xFFFF));

                if ((bytes = sendto(sp->sock, buf, toWrite, 0,

                        (struct sockaddr *) &server, sizeof(server))) < 0) {

                        bytes = tryAlternateSendTo(sp->sock, buf, toWrite, 0,

                        (struct sockaddr *) &server);

                }

        } else if (sp->flags & SOCKET_DATAGRAM) {

                server.sin_family = AF_INET;

                server.sin_addr.s_addr = inet_addr(sp->host);

                server.sin_port = htons((short)(sp->port & 0xFFFF));

                bytes = sendto(sp->sock, buf, toWrite, 0,

                        (struct sockaddr *) &server, sizeof(server));

        } else {

                bytes = send(sp->sock, buf, toWrite, 0);

        }

        if (bytes < 0) {

                *errCode = socketGetError();

#if WIN || CE 

                sp->currentEvents &= ~FD_WRITE;

#endif

                return -1;

        } else if (bytes == 0 && bytes != toWrite) {

                *errCode = EWOULDBLOCK;

#if WIN || CE

                sp->currentEvents &= ~FD_WRITE;

#endif

                return -1;

        }

/*

 *      Ensure we get to write some more data real soon if the socket can absorb

 *      more data

 */

#if !UEMF

#if WIN 

        if (sp->interestEvents & FD_WRITE) {

                emfTime_t blockTime = { 0, 0 };

                emfSetMaxBlockTime(&blockTime);

        }

#endif /* WIN */

#endif

        return bytes;

}

/******************************************************************************/

/*

 *              If the sendto failed, swap the first two bytes in the

 *              sockaddr structure.  This is a kludge due to a change in

 *              VxWorks between versions 5.3 and 5.4, but we want the

 *              product to run on either.

 */

static int tryAlternateSendTo(int sock, char *buf, int toWrite, int i,

                        struct sockaddr *server)

{

#if VXWORKS

        char *ptr;

        ptr = (char *)server;

        *ptr = *(ptr+1);

        *(ptr+1) = 0;

        return sendto(sock, buf, toWrite, i, server, sizeof(struct sockaddr));

#else

        return -1;

#endif /* VXWORKS */

}

/******************************************************************************/

/*

 *      Allocate a new socket structure

 */

int socketAlloc(char *host, int port, socketAccept_t accept, int flags)

{

        socket_t        *sp;

        int                     sid;

        if ((sid = hAllocEntry((void***) &socketList, &socketMax,

                        sizeof(socket_t))) < 0) {

                return -1;

        }

        sp = socketList[sid];

        sp->sid = sid;

        sp->accept = accept;

        sp->port = port;

        sp->fileHandle = -1;

        sp->saveMask = -1;

        if (host) {

                strncpy(sp->host, host, sizeof(sp->host));

        }

/*

 *      Preserve only specified flags from the callers open

 */

        a_assert((flags & ~(SOCKET_BROADCAST|SOCKET_DATAGRAM|SOCKET_BLOCK|

                                                SOCKET_LISTENING)) == 0);

        sp->flags = flags & (SOCKET_BROADCAST | SOCKET_DATAGRAM | SOCKET_BLOCK|

                                                SOCKET_LISTENING);

/*

 *      Add one to allow the user to write exactly SOCKET_BUFSIZ

 */

        ringqOpen(&sp->inBuf, SOCKET_BUFSIZ, SOCKET_BUFSIZ);

        ringqOpen(&sp->outBuf, SOCKET_BUFSIZ + 1, SOCKET_BUFSIZ + 1);

        ringqOpen(&sp->lineBuf, SOCKET_BUFSIZ, -1);

        return sid;

}

/******************************************************************************/

/*

 *      Free a socket structure

 */

void socketFree(int sid)

{

        socket_t        *sp;

        char_t          buf[256];

        int                     i;

        if ((sp = socketPtr(sid)) == NULL) {

                return;

        }

/*

 *      To close a socket, remove any registered interests, set it to

 *      non-blocking so that the recv which follows won't block, do a

 *      shutdown on it so peers on the other end will receive a FIN,

 *      then read any data not yet retrieved from the receive buffer,

 *      and finally close it.  If these steps are not all performed

 *      RESETs may be sent to the other end causing problems.

 */

        socketRegisterInterest(sp, 0);

        if (sp->sock >= 0) {

                socketSetBlock(sid, 0);

                if (shutdown(sp->sock, 1) >= 0) {

                        recv(sp->sock, buf, sizeof(buf), 0);

                }

#if WIN || CE

                closesocket(sp->sock);

#else

                close(sp->sock);

#endif

        }

        ringqClose(&sp->inBuf);

        ringqClose(&sp->outBuf);

        ringqClose(&sp->lineBuf);

        bfree(B_L, sp);

        socketMax = hFree((void***) &socketList, sid);

/*

 *      Calculate the new highest socket number

 */

        socketHighestFd = -1;

        for (i = 0; i < socketMax; i++) {

                if ((sp = socketList[i]) == NULL) {

                        continue;

                }

                socketHighestFd = max(socketHighestFd, sp->sock);

        }

}

/******************************************************************************/

/*

 *      Validate a socket handle

 */

socket_t *socketPtr(int sid)

{

        if (sid < 0 || sid >= socketMax || socketList[sid] == NULL) {

                a_assert(NULL);

                errno = EBADF;

                return NULL;

        }

        a_assert(socketList[sid]);

        return socketList[sid];

}

/******************************************************************************/

/*