server/socket/lowlevel.c


/*
 * static char *rcsid_sockets_c =
 *    "$Id: lowlevel.c,v 1.12 2005/12/05 23:34:04 akirschbaum Exp $";
 */

/*
    CrossFire, A Multiplayer game for X-windows

    Copyright (C) 1992 Frank Tore Johansen

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    The author can be reached via e-mail to mark@pyramid.com
*/

/**
 * \file
 * Low-level socket-related functions.
 *
 * \date 2003-12-02
 *
 * Contains some base functions that both the client and server
 * can use.  As such, depending what we are being compiled for will
 * determine what we can include.  the client is designed have
 * CFCLIENT defined as part of its compile flags.
 */

#include <global.h>
#include <newclient.h>
#include <sproto.h>

/***********************************************************************
 *
 * SockList functions/utilities
 *
 **********************************************************************/

void SockList_Init(SockList *sl)
{
    sl->len=0;
    sl->buf=NULL;
}

void SockList_AddChar(SockList *sl, char c)
{
    sl->buf[sl->len]=c;
    sl->len++;
}

void SockList_AddShort(SockList *sl, uint16 data)
{
    sl->buf[sl->len++]= (data>>8)&0xff;
    sl->buf[sl->len++] = data & 0xff;
}


void SockList_AddInt(SockList *sl, uint32 data)
{
    sl->buf[sl->len++]= (data>>24)&0xff;
    sl->buf[sl->len++]= (data>>16)&0xff;
    sl->buf[sl->len++]= (data>>8)&0xff;
    sl->buf[sl->len++] = data & 0xff;
}

void SockList_AddInt64(SockList *sl, uint64 data)
{
    sl->buf[sl->len++]= ( char )( (data>>56)&0xff );
    sl->buf[sl->len++]= ( char )( (data>>48)&0xff );
    sl->buf[sl->len++]= ( char )( (data>>40)&0xff );
    sl->buf[sl->len++]= ( char )( (data>>32)&0xff );

    sl->buf[sl->len++]= ( char )( (data>>24)&0xff );
    sl->buf[sl->len++]= ( char )( (data>>16)&0xff );
    sl->buf[sl->len++]= ( char )( (data>>8)&0xff );
    sl->buf[sl->len++] =( char )(  data & 0xff );
}

/* Basically does the reverse of SockList_AddInt, but on
 * strings instead.  Same for the GetShort, but for 16 bits.
 */
int GetInt_String(unsigned char *data)
{
    return ((data[0]<<24) + (data[1]<<16) + (data[2]<<8) + data[3]);
}

short GetShort_String(unsigned char *data) {
    return ((data[0]<<8)+data[1]);
}

/******************************************************************************
 *
 * Start of read routines.
 *
 ******************************************************************************/

/**
 * This reads from fd and puts the data in sl.  We return true if we think
 * we have a full packet, 0 if we have a partial packet.  The only processing
 * we do is remove the intial size value.  len (As passed) is the size of the
 * buffer allocated in the socklist.  We make the assumption the buffer is
 * at least 2 bytes long.
 */
 
int SockList_ReadPacket(int fd, SockList *sl, int len)
{
    int stat,toread;
    extern int errno;

    /* Sanity check - shouldn't happen */
    if (sl->len < 0) {
        abort();
    }
    /* We already have a partial packet */
    if (sl->len<2) {
#ifdef WIN32 /* ***WIN32 SockList_ReadPacket: change read() to recv() */

        stat=recv(fd, sl->buf + sl->len, 2-sl->len,0);

#else
        do {
                stat=read(fd, sl->buf + sl->len, 2-sl->len);
        } while ((stat==-1) && (errno==EINTR));
#endif
        if (stat<0) {
            /* In non blocking mode, EAGAIN is set when there is no
             * data available.
             */
#ifdef WIN32 /* ***WIN32 SockList_ReadPacket: error handling for win32 */
        if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
                if(WSAGetLastError() == WSAECONNRESET)
                        LOG(llevDebug,"Connection closed by client\n");
                else
                {
                        LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
                }
                return -1;      /* kick this user! */
            }
#else
        if (errno != EAGAIN && errno !=EWOULDBLOCK) {
                LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
            }
#endif
            return 0;   /*Error */
        }
        if (stat==0) return -1;
        sl->len += stat;
#ifdef CS_LOGSTATS
        cst_tot.ibytes += stat;
        cst_lst.ibytes += stat;
#endif
        if (stat<2) return 0;   /* Still don't have a full packet */
    }
    /* Figure out how much more data we need to read.  Add 2 from the
     * end of this - size header information is not included.
     */
    toread = 2+(sl->buf[0] << 8) + sl->buf[1] - sl->len;
    if ((toread + sl->len) >= len) {
        LOG(llevError,"SockList_ReadPacket: Want to read more bytes than will fit in buffer (%d>=%d).\n",
             toread + sl->len, len);
        /* Quick hack in case for 'oldsocketmode' input.  If we are
         * closing the socket anyways, then reading this extra 100 bytes
         * shouldn't hurt.
         */
#ifdef WIN32 /* ***win32 SockList_ReadPacket: change read() to recv() */
        recv(fd, sl->buf+2, 100, 0);
#else
        read(fd, sl->buf+2, 100);
#endif /* end win32 */

        /* return error so the socket is closed */
        return -1;
    }
    do {
#ifdef WIN32 /* ***win32 SockList_ReadPacket: change read() to recv() */
        stat = recv(fd, sl->buf+ sl->len, toread, 0);
#else
        do {
            stat = read(fd, sl->buf+ sl->len, toread);
        } while ((stat<0) && (errno==EINTR));
#endif
        if (stat<0) {

#ifdef WIN32 /* ***win32 SockList_ReadPacket: change error handling for win32 */
        if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
                if(WSAGetLastError() == WSAECONNRESET)
                        LOG(llevDebug,"Connection closed by client\n");
                else
                {
                        LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
                }
                return -1;      /* kick this user! */
            }
#else
        if (errno != EAGAIN && errno !=EWOULDBLOCK) {
                LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
            }
#endif
            return 0;   /*Error */
        }
        if (stat==0) return -1;
        sl->len += stat;
#ifdef CS_LOGSTATS
        cst_tot.ibytes += stat;
        cst_lst.ibytes += stat;
#endif
        toread -= stat;
        if (toread==0) return 1;
        if (toread < 0) {
            LOG(llevError,"SockList_ReadPacket: Read more bytes than desired.\n");
            return 1;
        }
    } while (toread>0);
    return 0;
}

/*******************************************************************************
 *
 * Start of write related routines.
 *
 ******************************************************************************/

/**
 * Adds data to a socket buffer for whatever reason.
 *
 * ns is the socket we are adding the data to, buf is the start of the
 * data, and len is the number of bytes to add.
 */

static void add_to_buffer(NewSocket *ns, unsigned char *buf, int len)
{
    int avail, end;

    if ((len+ns->outputbuffer.len)>SOCKETBUFSIZE) {
        LOG(llevDebug,"Socket on fd %d has overrun internal buffer - marking as dead\n",
            ns->fd);
        ns->status = Ns_Dead;
        return;
    }

    /* data + end is where we start putting the new data.  The last byte
     * currently in use is actually data + end -1
     */

    end=ns->outputbuffer.start + ns->outputbuffer.len;
    /* The buffer is already in a wrapped state, so adjust end */
    if (end>=SOCKETBUFSIZE) end-=SOCKETBUFSIZE;
    avail=SOCKETBUFSIZE - end;

    /* We can all fit it behind the current data without wrapping */
    if (avail >=len ) {
        memcpy(ns->outputbuffer.data + end, buf, len);
    }
    else {
        memcpy(ns->outputbuffer.data + end, buf, avail);
        memcpy(ns->outputbuffer.data, buf+avail, len-avail);
    }
    ns->outputbuffer.len += len;
#if 0
    LOG(llevDebug,"Added %d to output buffer, total length now %d, start=%d\n", len,
        ns->outputbuffer.len, ns->outputbuffer.start);
#endif
}

/**
 * Writes data to socket.
 *
 * When the socket is clear to write, and we have backlogged data, this
 * is called to write it out.
 */
void write_socket_buffer(NewSocket *ns)
{
    int amt, max;

    if (ns->outputbuffer.len==0) {
        LOG(llevDebug,"write_socket_buffer called when there is no data, fd=%d\n",
            ns->fd);
        return;
    }

    do {
        max = SOCKETBUFSIZE - ns->outputbuffer.start;
        if (ns->outputbuffer.len<max) max = ns->outputbuffer.len;

#ifdef WIN32 /* ***win32 write_socket_buffer: change write() to send() */
        amt=send(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max,0);
#else
        do {
            amt=write(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max);
        } while ((amt<0) && (errno==EINTR));
#endif

        if (amt < 0) { /* We got an error */

#ifdef WIN32 /* ***win32 write_socket_buffer: change error handling */
        if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
                LOG(llevError,"New socket write failed (wsb) (%d).\n", WSAGetLastError());
#else
        if (errno !=EWOULDBLOCK) {
                LOG(llevError,"New socket write failed (wsb) (%d: %s).\n",
                    errno, strerror_local(errno));
#endif
                ns->status=Ns_Dead;
                return;
            }
            else { /* EWOULDBLOCK */
                /* can't write it, so store it away. */
                ns->can_write=0;
                return;
            }
        }
        ns->outputbuffer.start += amt;
        /* wrap back to start of buffer */
        if (ns->outputbuffer.start==SOCKETBUFSIZE) ns->outputbuffer.start=0;
        ns->outputbuffer.len -= amt;
#ifdef CS_LOGSTATS
        cst_tot.obytes += amt;
        cst_lst.obytes += amt;
 #endif
    } while (ns->outputbuffer.len>0);
}

/**
 * This writes data to the socket. - It is very low level -
 * all we try and do is write out the data to the socket
 * provided (ns).  buf is the data to write, len is the number
 * of bytes to write.  IT doesn't return anything - rather, it
 * updates the ns structure if we get an  error.
 */
void Write_To_Socket(NewSocket *ns, unsigned char *buf, int len)
{
    int amt=0;
    unsigned char *pos=buf;

    if (ns->status == Ns_Dead || !buf) {
        LOG(llevDebug,"Write_To_Socket called with dead socket\n");
        return;
    }
 
#ifndef __GNU__ /* This caused problems on Hurd */
    if (!ns->can_write) {
        add_to_buffer(ns, buf, len);
        return;
    }
#endif
    /* If we manage to write more than we wanted, take it as a bonus */
    while (len>0) {

#ifdef WIN32 /* ***win32 Write_To_Socket: change write() to send() */
            amt=send(ns->fd, pos, len,0);
#else
        do {
            amt=write(ns->fd, pos, len);
        } while ((amt<0) && (errno==EINTR));
#endif

        if (amt < 0) { /* We got an error */
#ifdef WIN32 /* ***win32 Write_To_Socket: change error handling */
        if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
                LOG(llevError,"New socket write failed WTS (%d).\n",WSAGetLastError());
#else
        if (errno !=EWOULDBLOCK) {
                LOG(llevError,"New socket write failed WTS (%d: %s).\n", /* ---WIN32 */
                    errno, strerror_local(errno));
#endif
                ns->status=Ns_Dead;
                return;
            }
            else { /* EWOULDBLOCK */
                /* can't write it, so store it away. */
                add_to_buffer(ns, pos, len);
                ns->can_write=0;
                return;
            }
        }
        /* amt gets set to 0 above in blocking code, so we do this as
         * an else if to make sure we don't reprocess it.
         */
        else if (amt==0) {
            LOG(llevError,"Write_To_Socket: No data written out.\n");
        }
        len -= amt;
        pos += amt;
#ifdef CS_LOGSTATS
        cst_tot.obytes += amt;
        cst_lst.obytes += amt;
 #endif
    }
}


/**
 * Takes a string of data, and writes it out to the socket. A very handy
 * shortcut function.
 */
void cs_write_string(NewSocket *ns, const char *buf, int len)
{
    SockList sl;

    sl.len = len;
    sl.buf = (unsigned char*)buf;
    Send_With_Handling(ns, &sl);
}


/**
 * Calls Write_To_Socket to send data to the client.
 *
 * The only difference in this function is that we take a SockList
 *, and we prepend the length information.
 */
void Send_With_Handling(NewSocket *ns,SockList  *msg)
{
    unsigned char sbuf[4];

    if (ns->status == Ns_Dead || !msg)
        return;

    if (msg->len >= MAXSOCKBUF) {
        LOG(llevError,"Trying to send a buffer beyond properly size, len =%d\n",
            msg->len);
        /* Almost certainly we've overflowed a buffer, so quite now to make
         * it easier to debug.
         */
        abort();
    }
    sbuf[0] = ((uint32)(msg->len) >> 8) & 0xFF;
    sbuf[1] = ((uint32)(msg->len)) & 0xFF;
    if (ns->status != Ns_Old) 
        Write_To_Socket(ns, sbuf, 2);
    Write_To_Socket(ns, msg->buf, msg->len);
}

/**
 * Takes a string of data, and writes it out to the socket. A very handy
 * shortcut function.
 */
void Write_String_To_Socket(NewSocket *ns, char *buf, int len)
{
    SockList sl;

    sl.len = len;
    sl.buf = (uint8*)buf;
    Send_With_Handling(ns, &sl);
}


/******************************************************************************
 *
 * statistics logging functions.
 *
 ******************************************************************************/

#ifdef CS_LOGSTATS
/* cst_tot is for the life of the server, cst_last is for the last series of
 * stats
 */
CS_Stats cst_tot, cst_lst;

/**
 * Writes out the gathered stats.  We clear cst_lst.
 */
void write_cs_stats(void)
{
    time_t now=time(NULL);

    /* If no connections recently, don't both to log anything */
    if (cst_lst.ibytes==0 && cst_lst.obytes==0) return;

    /* CSSTAT is put in so scripts can easily find the line */
    LOG(llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
        ctime(&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
        now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes,
        cst_lst.max_conn, now - cst_lst.time_start);
    cst_lst.ibytes=0;
    cst_lst.obytes=0;
    cst_lst.max_conn=socket_info.nconns;
    cst_lst.time_start=now;
}
#endif
Revision:	1.1
Committed:	Fri Feb 3 07:14:44 2006 UTC (18 years, 3 months ago) by root
Content type:	text/plain
Branch:	MAIN
Branch point for:	UPSTREAM
Log Message:	Initial revision
#	User	Rev	Content
1	root	1.1
2			/*
3			* static char *rcsid_sockets_c =
4			* "$Id: lowlevel.c,v 1.12 2005/12/05 23:34:04 akirschbaum Exp $";
5			*/
6
7			/*
8			CrossFire, A Multiplayer game for X-windows
9
10			Copyright (C) 1992 Frank Tore Johansen
11
12			This program is free software; you can redistribute it and/or modify
13			it under the terms of the GNU General Public License as published by
14			the Free Software Foundation; either version 2 of the License, or
15			(at your option) any later version.
16
17			This program is distributed in the hope that it will be useful,
18			but WITHOUT ANY WARRANTY; without even the implied warranty of
19			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20			GNU General Public License for more details.
21
22			You should have received a copy of the GNU General Public License
23			along with this program; if not, write to the Free Software
24			Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25
26			The author can be reached via e-mail to mark@pyramid.com
27			*/
28
29			/**
30			* \file
31			* Low-level socket-related functions.
32			*
33			* \date 2003-12-02
34			*
35			* Contains some base functions that both the client and server
36			* can use. As such, depending what we are being compiled for will
37			* determine what we can include. the client is designed have
38			* CFCLIENT defined as part of its compile flags.
39			*/
40
41			#include <global.h>
42			#include <newclient.h>
43			#include <sproto.h>
44
45			/***********************************************************************
46			*
47			* SockList functions/utilities
48			*
49			**********************************************************************/
50
51			void SockList_Init(SockList *sl)
52			{
53			sl->len=0;
54			sl->buf=NULL;
55			}
56
57			void SockList_AddChar(SockList *sl, char c)
58			{
59			sl->buf[sl->len]=c;
60			sl->len++;
61			}
62
63			void SockList_AddShort(SockList *sl, uint16 data)
64			{
65			sl->buf[sl->len++]= (data>>8)&0xff;
66			sl->buf[sl->len++] = data & 0xff;
67			}
68
69
70			void SockList_AddInt(SockList *sl, uint32 data)
71			{
72			sl->buf[sl->len++]= (data>>24)&0xff;
73			sl->buf[sl->len++]= (data>>16)&0xff;
74			sl->buf[sl->len++]= (data>>8)&0xff;
75			sl->buf[sl->len++] = data & 0xff;
76			}
77
78			void SockList_AddInt64(SockList *sl, uint64 data)
79			{
80			sl->buf[sl->len++]= ( char )( (data>>56)&0xff );
81			sl->buf[sl->len++]= ( char )( (data>>48)&0xff );
82			sl->buf[sl->len++]= ( char )( (data>>40)&0xff );
83			sl->buf[sl->len++]= ( char )( (data>>32)&0xff );
84
85			sl->buf[sl->len++]= ( char )( (data>>24)&0xff );
86			sl->buf[sl->len++]= ( char )( (data>>16)&0xff );
87			sl->buf[sl->len++]= ( char )( (data>>8)&0xff );
88			sl->buf[sl->len++] =( char )( data & 0xff );
89			}
90
91			/* Basically does the reverse of SockList_AddInt, but on
92			* strings instead. Same for the GetShort, but for 16 bits.
93			*/
94			int GetInt_String(unsigned char *data)
95			{
96			return ((data[0]<<24) + (data[1]<<16) + (data[2]<<8) + data[3]);
97			}
98
99			short GetShort_String(unsigned char *data) {
100			return ((data[0]<<8)+data[1]);
101			}
102
103			/******************************************************************************
104			*
105			* Start of read routines.
106			*
107			******************************************************************************/
108
109			/**
110			* This reads from fd and puts the data in sl. We return true if we think
111			* we have a full packet, 0 if we have a partial packet. The only processing
112			* we do is remove the intial size value. len (As passed) is the size of the
113			* buffer allocated in the socklist. We make the assumption the buffer is
114			* at least 2 bytes long.
115			*/
116
117			int SockList_ReadPacket(int fd, SockList *sl, int len)
118			{
119			int stat,toread;
120			extern int errno;
121
122			/* Sanity check - shouldn't happen */
123			if (sl->len < 0) {
124			abort();
125			}
126			/* We already have a partial packet */
127			if (sl->len<2) {
128			#ifdef WIN32 /* **WIN32 SockList_ReadPacket: change read() to recv() /
129
130			stat=recv(fd, sl->buf + sl->len, 2-sl->len,0);
131
132			#else
133			do {
134			stat=read(fd, sl->buf + sl->len, 2-sl->len);
135			} while ((stat==-1) && (errno==EINTR));
136			#endif
137			if (stat<0) {
138			/* In non blocking mode, EAGAIN is set when there is no
139			* data available.
140			*/
141			#ifdef WIN32 /* **WIN32 SockList_ReadPacket: error handling for win32 /
142			if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
143			if(WSAGetLastError() == WSAECONNRESET)
144			LOG(llevDebug,"Connection closed by client\n");
145			else
146			{
147			LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
148			}
149			return -1; /* kick this user! */
150			}
151			#else
152			if (errno != EAGAIN && errno !=EWOULDBLOCK) {
153			LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
154			}
155			#endif
156			return 0; /Error /
157			}
158			if (stat==0) return -1;
159			sl->len += stat;
160			#ifdef CS_LOGSTATS
161			cst_tot.ibytes += stat;
162			cst_lst.ibytes += stat;
163			#endif
164			if (stat<2) return 0; /* Still don't have a full packet */
165			}
166			/* Figure out how much more data we need to read. Add 2 from the
167			* end of this - size header information is not included.
168			*/
169			toread = 2+(sl->buf[0] << 8) + sl->buf[1] - sl->len;
170			if ((toread + sl->len) >= len) {
171			LOG(llevError,"SockList_ReadPacket: Want to read more bytes than will fit in buffer (%d>=%d).\n",
172			toread + sl->len, len);
173			/* Quick hack in case for 'oldsocketmode' input. If we are
174			* closing the socket anyways, then reading this extra 100 bytes
175			* shouldn't hurt.
176			*/
177			#ifdef WIN32 /* **win32 SockList_ReadPacket: change read() to recv() /
178			recv(fd, sl->buf+2, 100, 0);
179			#else
180			read(fd, sl->buf+2, 100);
181			#endif /* end win32 */
182
183			/* return error so the socket is closed */
184			return -1;
185			}
186			do {
187			#ifdef WIN32 /* **win32 SockList_ReadPacket: change read() to recv() /
188			stat = recv(fd, sl->buf+ sl->len, toread, 0);
189			#else
190			do {
191			stat = read(fd, sl->buf+ sl->len, toread);
192			} while ((stat<0) && (errno==EINTR));
193			#endif
194			if (stat<0) {
195
196			#ifdef WIN32 /* **win32 SockList_ReadPacket: change error handling for win32 /
197			if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
198			if(WSAGetLastError() == WSAECONNRESET)
199			LOG(llevDebug,"Connection closed by client\n");
200			else
201			{
202			LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
203			}
204			return -1; /* kick this user! */
205			}
206			#else
207			if (errno != EAGAIN && errno !=EWOULDBLOCK) {
208			LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
209			}
210			#endif
211			return 0; /Error /
212			}
213			if (stat==0) return -1;
214			sl->len += stat;
215			#ifdef CS_LOGSTATS
216			cst_tot.ibytes += stat;
217			cst_lst.ibytes += stat;
218			#endif
219			toread -= stat;
220			if (toread==0) return 1;
221			if (toread < 0) {
222			LOG(llevError,"SockList_ReadPacket: Read more bytes than desired.\n");
223			return 1;
224			}
225			} while (toread>0);
226			return 0;
227			}
228
229			/*******************************************************************************
230			*
231			* Start of write related routines.
232			*
233			******************************************************************************/
234
235			/**
236			* Adds data to a socket buffer for whatever reason.
237			*
238			* ns is the socket we are adding the data to, buf is the start of the
239			* data, and len is the number of bytes to add.
240			*/
241
242			static void add_to_buffer(NewSocket ns, unsigned char buf, int len)
243			{
244			int avail, end;
245
246			if ((len+ns->outputbuffer.len)>SOCKETBUFSIZE) {
247			LOG(llevDebug,"Socket on fd %d has overrun internal buffer - marking as dead\n",
248			ns->fd);
249			ns->status = Ns_Dead;
250			return;
251			}
252
253			/* data + end is where we start putting the new data. The last byte
254			* currently in use is actually data + end -1
255			*/
256
257			end=ns->outputbuffer.start + ns->outputbuffer.len;
258			/* The buffer is already in a wrapped state, so adjust end */
259			if (end>=SOCKETBUFSIZE) end-=SOCKETBUFSIZE;
260			avail=SOCKETBUFSIZE - end;
261
262			/* We can all fit it behind the current data without wrapping */
263			if (avail >=len ) {
264			memcpy(ns->outputbuffer.data + end, buf, len);
265			}
266			else {
267			memcpy(ns->outputbuffer.data + end, buf, avail);
268			memcpy(ns->outputbuffer.data, buf+avail, len-avail);
269			}
270			ns->outputbuffer.len += len;
271			#if 0
272			LOG(llevDebug,"Added %d to output buffer, total length now %d, start=%d\n", len,
273			ns->outputbuffer.len, ns->outputbuffer.start);
274			#endif
275			}
276
277			/**
278			* Writes data to socket.
279			*
280			* When the socket is clear to write, and we have backlogged data, this
281			* is called to write it out.
282			*/
283			void write_socket_buffer(NewSocket *ns)
284			{
285			int amt, max;
286
287			if (ns->outputbuffer.len==0) {
288			LOG(llevDebug,"write_socket_buffer called when there is no data, fd=%d\n",
289			ns->fd);
290			return;
291			}
292
293			do {
294			max = SOCKETBUFSIZE - ns->outputbuffer.start;
295			if (ns->outputbuffer.len<max) max = ns->outputbuffer.len;
296
297			#ifdef WIN32 /* **win32 write_socket_buffer: change write() to send() /
298			amt=send(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max,0);
299			#else
300			do {
301			amt=write(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max);
302			} while ((amt<0) && (errno==EINTR));
303			#endif
304
305			if (amt < 0) { /* We got an error */
306
307			#ifdef WIN32 /* **win32 write_socket_buffer: change error handling /
308			if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
309			LOG(llevError,"New socket write failed (wsb) (%d).\n", WSAGetLastError());
310			#else
311			if (errno !=EWOULDBLOCK) {
312			LOG(llevError,"New socket write failed (wsb) (%d: %s).\n",
313			errno, strerror_local(errno));
314			#endif
315			ns->status=Ns_Dead;
316			return;
317			}
318			else { /* EWOULDBLOCK */
319			/* can't write it, so store it away. */
320			ns->can_write=0;
321			return;
322			}
323			}
324			ns->outputbuffer.start += amt;
325			/* wrap back to start of buffer */
326			if (ns->outputbuffer.start==SOCKETBUFSIZE) ns->outputbuffer.start=0;
327			ns->outputbuffer.len -= amt;
328			#ifdef CS_LOGSTATS
329			cst_tot.obytes += amt;
330			cst_lst.obytes += amt;
331			#endif
332			} while (ns->outputbuffer.len>0);
333			}
334
335			/**
336			* This writes data to the socket. - It is very low level -
337			* all we try and do is write out the data to the socket
338			* provided (ns). buf is the data to write, len is the number
339			* of bytes to write. IT doesn't return anything - rather, it
340			* updates the ns structure if we get an error.
341			*/
342			void Write_To_Socket(NewSocket ns, unsigned char buf, int len)
343			{
344			int amt=0;
345			unsigned char *pos=buf;
346
347			if (ns->status == Ns_Dead \|\| !buf) {
348			LOG(llevDebug,"Write_To_Socket called with dead socket\n");
349			return;
350			}
351
352			#ifndef __GNU__ /* This caused problems on Hurd */
353			if (!ns->can_write) {
354			add_to_buffer(ns, buf, len);
355			return;
356			}
357			#endif
358			/* If we manage to write more than we wanted, take it as a bonus */
359			while (len>0) {
360
361			#ifdef WIN32 /* **win32 Write_To_Socket: change write() to send() /
362			amt=send(ns->fd, pos, len,0);
363			#else
364			do {
365			amt=write(ns->fd, pos, len);
366			} while ((amt<0) && (errno==EINTR));
367			#endif
368
369			if (amt < 0) { /* We got an error */
370			#ifdef WIN32 /* **win32 Write_To_Socket: change error handling /
371			if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
372			LOG(llevError,"New socket write failed WTS (%d).\n",WSAGetLastError());
373			#else
374			if (errno !=EWOULDBLOCK) {
375			LOG(llevError,"New socket write failed WTS (%d: %s).\n", /* ---WIN32 */
376			errno, strerror_local(errno));
377			#endif
378			ns->status=Ns_Dead;
379			return;
380			}
381			else { /* EWOULDBLOCK */
382			/* can't write it, so store it away. */
383			add_to_buffer(ns, pos, len);
384			ns->can_write=0;
385			return;
386			}
387			}
388			/* amt gets set to 0 above in blocking code, so we do this as
389			* an else if to make sure we don't reprocess it.
390			*/
391			else if (amt==0) {
392			LOG(llevError,"Write_To_Socket: No data written out.\n");
393			}
394			len -= amt;
395			pos += amt;
396			#ifdef CS_LOGSTATS
397			cst_tot.obytes += amt;
398			cst_lst.obytes += amt;
399			#endif
400			}
401			}
402
403
404			/**
405			* Takes a string of data, and writes it out to the socket. A very handy
406			* shortcut function.
407			*/
408			void cs_write_string(NewSocket ns, const char buf, int len)
409			{
410			SockList sl;
411
412			sl.len = len;
413			sl.buf = (unsigned char*)buf;
414			Send_With_Handling(ns, &sl);
415			}
416
417
418			/**
419			* Calls Write_To_Socket to send data to the client.
420			*
421			* The only difference in this function is that we take a SockList
422			*, and we prepend the length information.
423			*/
424			void Send_With_Handling(NewSocket ns,SockList msg)
425			{
426			unsigned char sbuf[4];
427
428			if (ns->status == Ns_Dead \|\| !msg)
429			return;
430
431			if (msg->len >= MAXSOCKBUF) {
432			LOG(llevError,"Trying to send a buffer beyond properly size, len =%d\n",
433			msg->len);
434			/* Almost certainly we've overflowed a buffer, so quite now to make
435			* it easier to debug.
436			*/
437			abort();
438			}
439			sbuf[0] = ((uint32)(msg->len) >> 8) & 0xFF;
440			sbuf[1] = ((uint32)(msg->len)) & 0xFF;
441			if (ns->status != Ns_Old)
442			Write_To_Socket(ns, sbuf, 2);
443			Write_To_Socket(ns, msg->buf, msg->len);
444			}
445
446			/**
447			* Takes a string of data, and writes it out to the socket. A very handy
448			* shortcut function.
449			*/
450			void Write_String_To_Socket(NewSocket ns, char buf, int len)
451			{
452			SockList sl;
453
454			sl.len = len;
455			sl.buf = (uint8*)buf;
456			Send_With_Handling(ns, &sl);
457			}
458
459
460			/******************************************************************************
461			*
462			* statistics logging functions.
463			*
464			******************************************************************************/
465
466			#ifdef CS_LOGSTATS
467			/* cst_tot is for the life of the server, cst_last is for the last series of
468			* stats
469			*/
470			CS_Stats cst_tot, cst_lst;
471
472			/**
473			* Writes out the gathered stats. We clear cst_lst.
474			*/
475			void write_cs_stats(void)
476			{
477			time_t now=time(NULL);
478
479			/* If no connections recently, don't both to log anything */
480			if (cst_lst.ibytes==0 && cst_lst.obytes==0) return;
481
482			/* CSSTAT is put in so scripts can easily find the line */
483			LOG(llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
484			ctime(&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
485			now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes,
486			cst_lst.max_conn, now - cst_lst.time_start);
487			cst_lst.ibytes=0;
488			cst_lst.obytes=0;
489			cst_lst.max_conn=socket_info.nconns;
490			cst_lst.time_start=now;
491			}
492			#endif