server/socket/lowlevel.c


/*
 * static char *rcsid_sockets_c =
 *    "$Id$";
 */

/*
    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>

#ifdef __linux__
# include <sys/types.h>
# include <sys/socket.h>
# include <netinet/in.h>
# include <netinet/tcp.h>
#endif

void Socket_Flush (NewSocket *ns)
{
#ifdef __linux__
  int val;
  val = 0; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
  val = 1; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
#endif
}

/***********************************************************************
 *
 * 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:	1.2
Committed:	Sun May 21 23:46:39 2006 UTC (20 years, 3 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.1:	+17 -1 lines
Log Message:	Problem: server sends out 2 tcp packets per command (e.g. a 2-byte packet + a 10 byte packet for a small map1a command). Solution: rewrite that thing Workaround: on linux, uncork and cork again just before sleeping for the next tick, that solves the problem without hackery or rewriting it. This cuts the # of packets send by at least one half.
#	User	Rev	Content
1	root	1.1
2			/*
3			* static char *rcsid_sockets_c =
4	root	1.2	* "$Id$";
5	root	1.1	*/
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	root	1.2	#ifdef __linux__
46			# include <sys/types.h>
47			# include <sys/socket.h>
48			# include <netinet/in.h>
49			# include <netinet/tcp.h>
50			#endif
51
52			void Socket_Flush (NewSocket *ns)
53			{
54			#ifdef __linux__
55			int val;
56			val = 0; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
57			val = 1; setsockopt (ns->fd, IPPROTO_TCP, TCP_CORK, &val, sizeof (val));
58			#endif
59			}
60
61	root	1.1	/***********************************************************************
62			*
63			* SockList functions/utilities
64			*
65			**********************************************************************/
66
67			void SockList_Init(SockList *sl)
68			{
69			sl->len=0;
70			sl->buf=NULL;
71			}
72
73			void SockList_AddChar(SockList *sl, char c)
74			{
75			sl->buf[sl->len]=c;
76			sl->len++;
77			}
78
79			void SockList_AddShort(SockList *sl, uint16 data)
80			{
81			sl->buf[sl->len++]= (data>>8)&0xff;
82			sl->buf[sl->len++] = data & 0xff;
83			}
84
85
86			void SockList_AddInt(SockList *sl, uint32 data)
87			{
88			sl->buf[sl->len++]= (data>>24)&0xff;
89			sl->buf[sl->len++]= (data>>16)&0xff;
90			sl->buf[sl->len++]= (data>>8)&0xff;
91			sl->buf[sl->len++] = data & 0xff;
92			}
93
94			void SockList_AddInt64(SockList *sl, uint64 data)
95			{
96			sl->buf[sl->len++]= ( char )( (data>>56)&0xff );
97			sl->buf[sl->len++]= ( char )( (data>>48)&0xff );
98			sl->buf[sl->len++]= ( char )( (data>>40)&0xff );
99			sl->buf[sl->len++]= ( char )( (data>>32)&0xff );
100
101			sl->buf[sl->len++]= ( char )( (data>>24)&0xff );
102			sl->buf[sl->len++]= ( char )( (data>>16)&0xff );
103			sl->buf[sl->len++]= ( char )( (data>>8)&0xff );
104			sl->buf[sl->len++] =( char )( data & 0xff );
105			}
106
107			/* Basically does the reverse of SockList_AddInt, but on
108			* strings instead. Same for the GetShort, but for 16 bits.
109			*/
110			int GetInt_String(unsigned char *data)
111			{
112			return ((data[0]<<24) + (data[1]<<16) + (data[2]<<8) + data[3]);
113			}
114
115			short GetShort_String(unsigned char *data) {
116			return ((data[0]<<8)+data[1]);
117			}
118
119			/******************************************************************************
120			*
121			* Start of read routines.
122			*
123			******************************************************************************/
124
125			/**
126			* This reads from fd and puts the data in sl. We return true if we think
127			* we have a full packet, 0 if we have a partial packet. The only processing
128			* we do is remove the intial size value. len (As passed) is the size of the
129			* buffer allocated in the socklist. We make the assumption the buffer is
130			* at least 2 bytes long.
131			*/
132
133			int SockList_ReadPacket(int fd, SockList *sl, int len)
134			{
135			int stat,toread;
136			extern int errno;
137
138			/* Sanity check - shouldn't happen */
139			if (sl->len < 0) {
140			abort();
141			}
142			/* We already have a partial packet */
143			if (sl->len<2) {
144			#ifdef WIN32 /* **WIN32 SockList_ReadPacket: change read() to recv() /
145
146			stat=recv(fd, sl->buf + sl->len, 2-sl->len,0);
147
148			#else
149			do {
150			stat=read(fd, sl->buf + sl->len, 2-sl->len);
151			} while ((stat==-1) && (errno==EINTR));
152			#endif
153			if (stat<0) {
154			/* In non blocking mode, EAGAIN is set when there is no
155			* data available.
156			*/
157			#ifdef WIN32 /* **WIN32 SockList_ReadPacket: error handling for win32 /
158			if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
159			if(WSAGetLastError() == WSAECONNRESET)
160			LOG(llevDebug,"Connection closed by client\n");
161			else
162			{
163			LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
164			}
165			return -1; /* kick this user! */
166			}
167			#else
168			if (errno != EAGAIN && errno !=EWOULDBLOCK) {
169			LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
170			}
171			#endif
172			return 0; /Error /
173			}
174			if (stat==0) return -1;
175			sl->len += stat;
176			#ifdef CS_LOGSTATS
177			cst_tot.ibytes += stat;
178			cst_lst.ibytes += stat;
179			#endif
180			if (stat<2) return 0; /* Still don't have a full packet */
181			}
182			/* Figure out how much more data we need to read. Add 2 from the
183			* end of this - size header information is not included.
184			*/
185			toread = 2+(sl->buf[0] << 8) + sl->buf[1] - sl->len;
186			if ((toread + sl->len) >= len) {
187			LOG(llevError,"SockList_ReadPacket: Want to read more bytes than will fit in buffer (%d>=%d).\n",
188			toread + sl->len, len);
189			/* Quick hack in case for 'oldsocketmode' input. If we are
190			* closing the socket anyways, then reading this extra 100 bytes
191			* shouldn't hurt.
192			*/
193			#ifdef WIN32 /* **win32 SockList_ReadPacket: change read() to recv() /
194			recv(fd, sl->buf+2, 100, 0);
195			#else
196			read(fd, sl->buf+2, 100);
197			#endif /* end win32 */
198
199			/* return error so the socket is closed */
200			return -1;
201			}
202			do {
203			#ifdef WIN32 /* **win32 SockList_ReadPacket: change read() to recv() /
204			stat = recv(fd, sl->buf+ sl->len, toread, 0);
205			#else
206			do {
207			stat = read(fd, sl->buf+ sl->len, toread);
208			} while ((stat<0) && (errno==EINTR));
209			#endif
210			if (stat<0) {
211
212			#ifdef WIN32 /* **win32 SockList_ReadPacket: change error handling for win32 /
213			if ((stat==-1) && WSAGetLastError() !=WSAEWOULDBLOCK) {
214			if(WSAGetLastError() == WSAECONNRESET)
215			LOG(llevDebug,"Connection closed by client\n");
216			else
217			{
218			LOG(llevDebug,"ReadPacket got error %d, returning 0\n",WSAGetLastError());
219			}
220			return -1; /* kick this user! */
221			}
222			#else
223			if (errno != EAGAIN && errno !=EWOULDBLOCK) {
224			LOG(llevDebug, "ReadPacket got error %s, returning 0\n", strerror_local(errno));
225			}
226			#endif
227			return 0; /Error /
228			}
229			if (stat==0) return -1;
230			sl->len += stat;
231			#ifdef CS_LOGSTATS
232			cst_tot.ibytes += stat;
233			cst_lst.ibytes += stat;
234			#endif
235			toread -= stat;
236			if (toread==0) return 1;
237			if (toread < 0) {
238			LOG(llevError,"SockList_ReadPacket: Read more bytes than desired.\n");
239			return 1;
240			}
241			} while (toread>0);
242			return 0;
243			}
244
245			/*******************************************************************************
246			*
247			* Start of write related routines.
248			*
249			******************************************************************************/
250
251			/**
252			* Adds data to a socket buffer for whatever reason.
253			*
254			* ns is the socket we are adding the data to, buf is the start of the
255			* data, and len is the number of bytes to add.
256			*/
257
258			static void add_to_buffer(NewSocket ns, unsigned char buf, int len)
259			{
260			int avail, end;
261
262			if ((len+ns->outputbuffer.len)>SOCKETBUFSIZE) {
263			LOG(llevDebug,"Socket on fd %d has overrun internal buffer - marking as dead\n",
264			ns->fd);
265			ns->status = Ns_Dead;
266			return;
267			}
268
269			/* data + end is where we start putting the new data. The last byte
270			* currently in use is actually data + end -1
271			*/
272
273			end=ns->outputbuffer.start + ns->outputbuffer.len;
274			/* The buffer is already in a wrapped state, so adjust end */
275			if (end>=SOCKETBUFSIZE) end-=SOCKETBUFSIZE;
276			avail=SOCKETBUFSIZE - end;
277
278			/* We can all fit it behind the current data without wrapping */
279			if (avail >=len ) {
280			memcpy(ns->outputbuffer.data + end, buf, len);
281			}
282			else {
283			memcpy(ns->outputbuffer.data + end, buf, avail);
284			memcpy(ns->outputbuffer.data, buf+avail, len-avail);
285			}
286			ns->outputbuffer.len += len;
287			#if 0
288			LOG(llevDebug,"Added %d to output buffer, total length now %d, start=%d\n", len,
289			ns->outputbuffer.len, ns->outputbuffer.start);
290			#endif
291			}
292
293			/**
294			* Writes data to socket.
295			*
296			* When the socket is clear to write, and we have backlogged data, this
297			* is called to write it out.
298			*/
299			void write_socket_buffer(NewSocket *ns)
300			{
301			int amt, max;
302
303			if (ns->outputbuffer.len==0) {
304			LOG(llevDebug,"write_socket_buffer called when there is no data, fd=%d\n",
305			ns->fd);
306			return;
307			}
308
309			do {
310			max = SOCKETBUFSIZE - ns->outputbuffer.start;
311			if (ns->outputbuffer.len<max) max = ns->outputbuffer.len;
312
313			#ifdef WIN32 /* **win32 write_socket_buffer: change write() to send() /
314			amt=send(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max,0);
315			#else
316			do {
317			amt=write(ns->fd, ns->outputbuffer.data + ns->outputbuffer.start, max);
318			} while ((amt<0) && (errno==EINTR));
319			#endif
320
321			if (amt < 0) { /* We got an error */
322
323			#ifdef WIN32 /* **win32 write_socket_buffer: change error handling /
324			if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
325			LOG(llevError,"New socket write failed (wsb) (%d).\n", WSAGetLastError());
326			#else
327			if (errno !=EWOULDBLOCK) {
328			LOG(llevError,"New socket write failed (wsb) (%d: %s).\n",
329			errno, strerror_local(errno));
330			#endif
331			ns->status=Ns_Dead;
332			return;
333			}
334			else { /* EWOULDBLOCK */
335			/* can't write it, so store it away. */
336			ns->can_write=0;
337			return;
338			}
339			}
340			ns->outputbuffer.start += amt;
341			/* wrap back to start of buffer */
342			if (ns->outputbuffer.start==SOCKETBUFSIZE) ns->outputbuffer.start=0;
343			ns->outputbuffer.len -= amt;
344			#ifdef CS_LOGSTATS
345			cst_tot.obytes += amt;
346			cst_lst.obytes += amt;
347			#endif
348			} while (ns->outputbuffer.len>0);
349			}
350
351			/**
352			* This writes data to the socket. - It is very low level -
353			* all we try and do is write out the data to the socket
354			* provided (ns). buf is the data to write, len is the number
355			* of bytes to write. IT doesn't return anything - rather, it
356			* updates the ns structure if we get an error.
357			*/
358			void Write_To_Socket(NewSocket ns, unsigned char buf, int len)
359			{
360			int amt=0;
361			unsigned char *pos=buf;
362
363			if (ns->status == Ns_Dead \|\| !buf) {
364			LOG(llevDebug,"Write_To_Socket called with dead socket\n");
365			return;
366			}
367
368			#ifndef __GNU__ /* This caused problems on Hurd */
369			if (!ns->can_write) {
370			add_to_buffer(ns, buf, len);
371			return;
372			}
373			#endif
374			/* If we manage to write more than we wanted, take it as a bonus */
375			while (len>0) {
376
377			#ifdef WIN32 /* **win32 Write_To_Socket: change write() to send() /
378			amt=send(ns->fd, pos, len,0);
379			#else
380			do {
381			amt=write(ns->fd, pos, len);
382			} while ((amt<0) && (errno==EINTR));
383			#endif
384
385			if (amt < 0) { /* We got an error */
386			#ifdef WIN32 /* **win32 Write_To_Socket: change error handling /
387			if (amt == -1 && WSAGetLastError() !=WSAEWOULDBLOCK) {
388			LOG(llevError,"New socket write failed WTS (%d).\n",WSAGetLastError());
389			#else
390			if (errno !=EWOULDBLOCK) {
391			LOG(llevError,"New socket write failed WTS (%d: %s).\n", /* ---WIN32 */
392			errno, strerror_local(errno));
393			#endif
394			ns->status=Ns_Dead;
395			return;
396			}
397			else { /* EWOULDBLOCK */
398			/* can't write it, so store it away. */
399			add_to_buffer(ns, pos, len);
400			ns->can_write=0;
401			return;
402			}
403			}
404			/* amt gets set to 0 above in blocking code, so we do this as
405			* an else if to make sure we don't reprocess it.
406			*/
407			else if (amt==0) {
408			LOG(llevError,"Write_To_Socket: No data written out.\n");
409			}
410			len -= amt;
411			pos += amt;
412			#ifdef CS_LOGSTATS
413			cst_tot.obytes += amt;
414			cst_lst.obytes += amt;
415			#endif
416			}
417			}
418
419
420			/**
421			* Takes a string of data, and writes it out to the socket. A very handy
422			* shortcut function.
423			*/
424			void cs_write_string(NewSocket ns, const char buf, int len)
425			{
426			SockList sl;
427
428			sl.len = len;
429			sl.buf = (unsigned char*)buf;
430			Send_With_Handling(ns, &sl);
431			}
432
433
434			/**
435			* Calls Write_To_Socket to send data to the client.
436			*
437			* The only difference in this function is that we take a SockList
438			*, and we prepend the length information.
439			*/
440			void Send_With_Handling(NewSocket ns,SockList msg)
441			{
442			unsigned char sbuf[4];
443
444			if (ns->status == Ns_Dead \|\| !msg)
445			return;
446
447			if (msg->len >= MAXSOCKBUF) {
448			LOG(llevError,"Trying to send a buffer beyond properly size, len =%d\n",
449			msg->len);
450			/* Almost certainly we've overflowed a buffer, so quite now to make
451			* it easier to debug.
452			*/
453			abort();
454			}
455			sbuf[0] = ((uint32)(msg->len) >> 8) & 0xFF;
456			sbuf[1] = ((uint32)(msg->len)) & 0xFF;
457			if (ns->status != Ns_Old)
458			Write_To_Socket(ns, sbuf, 2);
459			Write_To_Socket(ns, msg->buf, msg->len);
460			}
461
462			/**
463			* Takes a string of data, and writes it out to the socket. A very handy
464			* shortcut function.
465			*/
466			void Write_String_To_Socket(NewSocket ns, char buf, int len)
467			{
468			SockList sl;
469
470			sl.len = len;
471			sl.buf = (uint8*)buf;
472			Send_With_Handling(ns, &sl);
473			}
474
475
476			/******************************************************************************
477			*
478			* statistics logging functions.
479			*
480			******************************************************************************/
481
482			#ifdef CS_LOGSTATS
483			/* cst_tot is for the life of the server, cst_last is for the last series of
484			* stats
485			*/
486			CS_Stats cst_tot, cst_lst;
487
488			/**
489			* Writes out the gathered stats. We clear cst_lst.
490			*/
491			void write_cs_stats(void)
492			{
493			time_t now=time(NULL);
494
495			/* If no connections recently, don't both to log anything */
496			if (cst_lst.ibytes==0 && cst_lst.obytes==0) return;
497
498			/* CSSTAT is put in so scripts can easily find the line */
499			LOG(llevInfo, "CSSTAT: %.16s tot %d %d %d %d inc %d %d %d %d\n",
500			ctime(&now), cst_tot.ibytes, cst_tot.obytes, cst_tot.max_conn,
501			now - cst_tot.time_start, cst_lst.ibytes, cst_lst.obytes,
502			cst_lst.max_conn, now - cst_lst.time_start);
503			cst_lst.ibytes=0;
504			cst_lst.obytes=0;
505			cst_lst.max_conn=socket_info.nconns;
506			cst_lst.time_start=now;
507			}
508			#endif