1 /* $Id: ipx_udp.c,v 1.10 2004-01-08 16:48:34 schaffner Exp $ */
4 * IPX driver for native Linux TCP/IP networking (UDP implementation)
6 * Contact Jan [Lace] Kratochvil <short@ucw.cz> for assistance
7 * (no "It somehow doesn't work! What should I do?" complaints, please)
8 * Special thanks to Vojtech Pavlik <vojtech@ucw.cz> for testing.
10 * Also you may see KIX - KIX kix out KaliNix (in Linux-Linux only):
11 * http://atrey.karlin.mff.cuni.cz/~short/sw/kix.c.gz
13 * Primarily based on ipx_kali.c - "IPX driver for KaliNix interface"
14 * which is probably mostly by Jay Cotton <jay@kali.net>.
15 * Parts shamelessly stolen from my KIX v0.99.2 and GGN v0.100
19 * 0.99.1 - now the default broadcast list also contains all point-to-point
20 * links with their destination peer addresses
21 * 0.99.2 - commented a bit :-)
22 * - now adds to broadcast list each host it gets some packet from
23 * which is already not covered by local physical ethernet broadcast
24 * - implemented short-signature packet format
25 * - compatibility mode for old D1X releases due to the previous bullet
29 * No network server software is needed, neither KIX nor KaliNIX.
31 * NOTE: with the change to allow the user to choose the network
32 * driver from the game menu, the following is not anymore precise:
33 * the command line argument "-udp" is only necessary to supply udp
36 * Add command line argument "-udp". In default operation D1X will send
37 * broadcasts too all the local interfaces found. But you may also use
38 * additional parameter specified after "-udp" to modify the default
39 * broadcasting style and UDP port numbers binding:
41 * ./d1x -udp [@SHIFT]=HOST_LIST Broadcast ONLY to HOST_LIST
42 * ./d1x -udp [@SHIFT]+HOST_LIST Broadcast both to local ifaces & to HOST_LIST
44 * HOST_LIST is a comma (',') separated list of HOSTs:
45 * HOST is an IPv4 address (so-called quad like 192.168.1.2) or regular hostname
46 * HOST can also be in form 'address:SHIFT'
47 * SHIFT sets the UDP port base offset (e.g. +2), can be used to run multiple
48 * clients on one host simultaneously. This SHIFT has nothing to do
49 * with the dynamic-sockets (PgUP/PgDOWN) option in Descent, it's another
50 * higher-level differentiation option.
55 * - Run D1X to participate in normal local network (Linux only, of course)
57 * ./d1x -udp @1=localhost:2 & ./d1x -udp @2=localhost:1
58 * - Run two clients simultaneously fighting each other (only each other)
60 * ./d1x -udp =192.168.4.255
61 * - Run distant Descent which will participate with remote network
62 * 192.168.4.0 with netmask 255.255.255.0 (broadcast has 192.168.4.255)
63 * - You'll have to also setup hosts in that network accordingly:
64 * ./d1x -udp +UPPER_DISTANT_MACHINE_NAME
76 #include <arpa/inet.h>
77 #include <netinet/in.h> /* for htons & co. */
85 #include <sys/ioctl.h>
86 #include <sys/socket.h>
88 # include <sys/sockio.h>
96 extern unsigned char ipx_MyAddress[10];
100 #define UDP_BASEPORT 28342
101 #define PORTSHIFT_TOLERANCE 0x100
102 #define MAX_PACKETSIZE 8192
104 /* Packet format: first is the signature { 0xD1,'X' } which can be also
105 * { 'D','1','X','u','d','p'} for old-fashioned packets.
106 * Then follows virtual socket number (as changed during PgDOWN/PgUP)
107 * in network-byte-order as 2 bytes (u_short). After such 4/8 byte header
108 * follows raw data as communicated with D1X network core functions.
111 // Length HAS TO BE 6!
112 #define D1Xudp "D1Xudp"
113 // Length HAS TO BE 2!
114 #define D1Xid "\xD1X"
116 static int open_sockets = 0;
117 static int dynamic_socket = 0x401;
118 static const int val_one=1;
120 /* OUR port. Can be changed by "@X[+=]..." argument (X is the shift value)
123 static int baseport=UDP_BASEPORT;
125 /* Have we some old D1X in network and have we to maintain compatibility?
126 * FIXME: Following scenario is braindead:
127 * A (NEW) , B (OLD) , C (NEW)
128 * host A) We start new D1X. A-newcomm, B-none , C-none
129 * host B) We start OLD D1X. A-newcomm, B-oldcomm, C-none
130 * Now host A hears host B and switches: A-oldcomm, B-oldcomm, C-none
131 * host C) We start new D1X. A-oldcomm, B-oldcomm, C-newcomm
132 * Now host C hears host A/B and switches: A-oldcomm, B-oldcomm, C-oldcomm
133 * Now host B finishes: A-oldcomm, B-none , C-oldcomm
135 * But right now we have hosts A and C, both new code equipped but
136 * communicating wastefully by the OLD protocol! Bummer.
139 static char compatibility=0;
141 static int have_empty_address() {
143 for (i = 0; i < 10 && !ipx_MyAddress[i]; i++) ;
147 #define MSGHDR "IPX_udp: "
149 static void msg(const char *fmt,...)
152 fputs(MSGHDR,stdout);
159 static void chk(void *p)
162 msg("FATAL: Virtual memory exhausted!");
166 #define FAIL(m...) do { msg(#m); return -1; } while (0)
168 /* Find as much as MAX_BRDINTERFACES during local iface autoconfiguration.
169 * Note that more interfaces can be added during manual configuration
170 * or host-received-packet autoconfiguration
173 #define MAX_BRDINTERFACES 16
175 /* We require the interface to be UP and RUNNING to accept it.
178 #define IF_REQFLAGS (IFF_UP|IFF_RUNNING)
180 /* We reject any interfaces declared as LOOPBACK type.
182 #define IF_NOTFLAGS (IFF_LOOPBACK)
184 static struct sockaddr_in *broads,broadmasks[MAX_BRDINTERFACES];
185 static int broadnum,masksnum,broadsize;
187 /* We'll check whether the "broads" array of destination addresses is now
188 * full and so needs expanding.
191 static void chkbroadsize(void)
193 if (broadnum<broadsize) return;
194 broadsize=broadsize?broadsize*2:8;
195 chk(broads=realloc(broads,sizeof(*broads)*broadsize));
198 /* This function is called during init and has to grab all system interfaces
199 * and collect their broadcast-destination addresses (and their netmasks).
200 * Typically it founds only one ethernet card and so returns address in
201 * the style "192.168.1.255" with netmask "255.255.255.0".
202 * Broadcast addresses are filled into "broads", netmasks to "broadmasks".
205 /* Stolen from my GGN */
206 static int addiflist(void)
208 unsigned cnt=MAX_BRDINTERFACES,i,j;
209 struct ifconf ifconf;
211 struct sockaddr_in *sinp,*sinmp;
214 if ((sock=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP))<0)
215 FAIL("Creating socket() failure during broadcast detection: %m");
218 if (ioctl(sock,SIOCGIFCOUNT,&cnt))
219 { /* msg("Getting iterface count error: %m"); */ }
224 chk(ifconf.ifc_req=alloca((ifconf.ifc_len=cnt*sizeof(struct ifreq))));
225 if (ioctl(sock,SIOCGIFCONF,&ifconf)||ifconf.ifc_len%sizeof(struct ifreq)) {
227 FAIL("ioctl(SIOCGIFCONF) failure during broadcast detection: %m");
229 cnt=ifconf.ifc_len/sizeof(struct ifreq);
230 chk(broads=malloc(cnt*sizeof(*broads)));
232 for (i=j=0;i<cnt;i++) {
233 if (ioctl(sock,SIOCGIFFLAGS,ifconf.ifc_req+i)) {
235 FAIL("ioctl(udp,\"%s\",SIOCGIFFLAGS) error: %m",ifconf.ifc_req[i].ifr_name);
237 if (((ifconf.ifc_req[i].ifr_flags&IF_REQFLAGS)!=IF_REQFLAGS)||
238 (ifconf.ifc_req[i].ifr_flags&IF_NOTFLAGS))
240 if (ioctl(sock,(ifconf.ifc_req[i].ifr_flags&IFF_BROADCAST?SIOCGIFBRDADDR:SIOCGIFDSTADDR),ifconf.ifc_req+i)) {
242 FAIL("ioctl(udp,\"%s\",SIOCGIF{DST/BRD}ADDR) error: %m",ifconf.ifc_req[i].ifr_name);
245 sinp = (struct sockaddr_in *)&ifconf.ifc_req[i].ifr_broadaddr;
246 #if 0 // old, not portable code
247 sinmp = (struct sockaddr_in *)&ifconf.ifc_req[i].ifr_netmask;
248 #else // portable code
249 if (ioctl(sock, SIOCGIFNETMASK, ifconf.ifc_req+i)) {
251 FAIL("ioctl(udp,\"%s\",SIOCGIFNETMASK) error: %m", ifconf.ifc_req[i].ifr_name);
253 sinmp = (struct sockaddr_in *)&ifconf.ifc_req[i].ifr_addr;
255 if (sinp->sin_family!=AF_INET || sinmp->sin_family!=AF_INET) continue;
257 broads[j].sin_port=UDP_BASEPORT; //FIXME: No possibility to override from cmdline
258 broadmasks[j]=*sinmp;
266 #define addreq(a,b) ((a).sin_port==(b).sin_port&&(a).sin_addr.s_addr==(b).sin_addr.s_addr)
268 /* Previous function addiflist() can (and probably will) report multiple
269 * same addresses. On some Linux boxes is present both device "eth0" and
270 * "dummy0" with the same IP addreesses - we'll filter it here.
273 static void unifyiflist(void)
277 for (s=0;s<broadnum;s++) {
279 if (addreq(broads[s],broads[i])) break;
280 if (i>=s) broads[d++]=broads[s];
285 static unsigned char qhbuf[6];
287 /* Parse PORTSHIFT numeric parameter
290 static void portshift(const char *cs)
293 unsigned short ports=0;
296 if (port<-PORTSHIFT_TOLERANCE || port>+PORTSHIFT_TOLERANCE)
297 msg("Invalid portshift in \"%s\", tolerance is +/-%d",cs,PORTSHIFT_TOLERANCE);
298 else ports=htons(port);
299 memcpy(qhbuf+4,&ports,2);
302 /* Do hostname resolve on name "buf" and return the address in buffer "qhbuf".
304 static unsigned char *queryhost(char *buf)
310 if ((s=strrchr(buf,':'))) {
315 else memset(qhbuf+4,0,2);
316 he=gethostbyname((char *)buf);
319 msg("Error resolving my hostname \"%s\"",buf);
322 if (he->h_addrtype!=AF_INET || he->h_length!=4) {
323 msg("Error parsing resolved my hostname \"%s\"",buf);
326 if (!*he->h_addr_list) {
327 msg("My resolved hostname \"%s\" address list empty",buf);
330 memcpy(qhbuf,(*he->h_addr_list),4);
334 /* Dump raw form of IP address/port by fancy output to user
336 static void dumpraddr(unsigned char *a)
339 printf("[%u.%u.%u.%u]",a[0],a[1],a[2],a[3]);
340 port=(signed short)ntohs(*(unsigned short *)(a+4));
341 if (port) printf(":%+d",port);
344 /* Like dumpraddr() but for structure "sockaddr_in"
347 static void dumpaddr(struct sockaddr_in *sin)
349 unsigned short ports;
351 memcpy(qhbuf+0,&sin->sin_addr,4);
352 ports=htons(((short)ntohs(sin->sin_port))-UDP_BASEPORT);
353 memcpy(qhbuf+4,&ports,2);
357 /* Startup... Uninteresting parsing...
360 int ipx_udp_GetMyAddress(void) {
366 if (!have_empty_address())
369 if (!((i=FindArg("-udp")) && (s=Args[i+1]) && (*s=='=' || *s=='+' || *s=='@'))) s=NULL;
371 if (gethostname(buf,sizeof(buf))) FAIL("Error getting my hostname");
372 if (!(queryhost(buf))) FAIL("Querying my own hostname \"%s\"",buf);
374 if (s) while (*s=='@') {
376 while (isdigit(*s)) s++;
379 memset(ipx_MyAddress+0,0,4);
380 memcpy(ipx_MyAddress+4,qhbuf,6);
381 baseport+=(short)ntohs(*(unsigned short *)(qhbuf+4));
383 if (!s || (s && !*s)) addiflist();
385 if (*s=='+') addiflist();
388 struct sockaddr_in *sin;
389 while (isspace(*s)) s++;
391 for (s2=s;*s2 && *s2!=',';s2++);
392 chk(ns=malloc(s2-s+1));
395 if (!queryhost(ns)) msg("Ignored broadcast-destination \"%s\" as being invalid",ns);
398 sin=broads+(broadnum++);
399 sin->sin_family=AF_INET;
400 memcpy(&sin->sin_addr,qhbuf+0,4);
401 sin->sin_port=htons(((short)ntohs(*(unsigned short *)(qhbuf+4)))+UDP_BASEPORT);
408 printf(MSGHDR "Using TCP/IP address ");
409 dumpraddr(ipx_MyAddress+4);
412 printf(MSGHDR "Using %u broadcast-dest%s:",broadnum,(broadnum==1?"":"s"));
413 for (i=0;i<broadnum;i++) {
423 /* We should probably avoid such insanity here as during PgUP/PgDOWN
424 * (virtual port number change) we wastefully destroy/create the same
425 * socket here (binded always to "baseport"). FIXME.
426 * "open_sockets" can be only 0 or 1 anyway.
429 static int ipx_udp_OpenSocket(ipx_socket_t *sk, int port) {
430 struct sockaddr_in sin;
433 if (have_empty_address())
434 if (ipx_udp_GetMyAddress() < 0) FAIL("Error getting my address");
436 msg("OpenSocket on D1X socket port %d",port);
439 port = dynamic_socket++;
441 if ((sk->fd = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP)) < 0) {
443 FAIL("socket() creation failed on port %d: %m",port);
445 if (setsockopt(sk->fd,SOL_SOCKET,SO_BROADCAST,&val_one,sizeof(val_one))) {
446 if (close(sk->fd)) msg("close() failed during error recovery: %m");
448 FAIL("setsockopt(SO_BROADCAST) failed: %m");
450 sin.sin_family=AF_INET;
451 sin.sin_addr.s_addr=htonl(INADDR_ANY);
452 sin.sin_port=htons(baseport);
453 if (bind(sk->fd,(struct sockaddr *)&sin,sizeof(sin))) {
454 if (close(sk->fd)) msg("close() failed during error recovery: %m");
456 FAIL("bind() to UDP port %d failed: %m",baseport);
464 /* The same comment as in previous "ipx_udp_OpenSocket"...
467 static void ipx_udp_CloseSocket(ipx_socket_t *mysock) {
469 msg("close w/o open");
472 msg("CloseSocket on D1X socket port %d",mysock->socket);
473 if (close(mysock->fd))
474 msg("close() failed on CloseSocket D1X socket port %d: %m",mysock->socket);
476 if (--open_sockets) {
477 msg("(closesocket) %d sockets left", open_sockets);
482 /* Here we'll send the packet to our host. If it is unicast packet, send
483 * it to IP address/port as retrieved from IPX address. Otherwise (broadcast)
484 * we'll repeat the same data to each host in our broadcasting list.
487 static int ipx_udp_SendPacket(ipx_socket_t *mysock, IPXPacket_t *IPXHeader,
488 u_char *data, int dataLen) {
489 struct sockaddr_in toaddr,*dest;
495 msg("SendPacket enter, dataLen=%d",dataLen);
497 if (dataLen<0 || dataLen>MAX_PACKETSIZE) return -1;
498 chk(buf=alloca(8+dataLen));
499 if (compatibility) memcpy(buf+0,D1Xudp,6),buf+=6;
500 else memcpy(buf+0,D1Xid ,2),buf+=2;
501 memcpy(buf+0,IPXHeader->Destination.Socket,2);
502 memcpy(buf+2,data,dataLen);
504 toaddr.sin_family=AF_INET;
505 memcpy(&toaddr.sin_addr,IPXHeader->Destination.Node+0,4);
506 toaddr.sin_port=htons(((short)ntohs(*(unsigned short *)(IPXHeader->Destination.Node+4)))+UDP_BASEPORT);
508 for (bcast=(toaddr.sin_addr.s_addr==htonl(INADDR_BROADCAST)?0:-1);bcast<broadnum;bcast++) {
509 if (bcast>=0) dest=broads+bcast;
513 printf(MSGHDR "sendto((%d),Node=[4] %02X %02X,Socket=%02X %02X,s_port=%u,",
515 IPXHeader->Destination.Node [4],IPXHeader->Destination.Node [5],
516 IPXHeader->Destination.Socket[0],IPXHeader->Destination.Socket[1],
517 ntohs(dest->sin_port));
521 i=sendto(mysock->fd,buf-(compatibility?6:2),(compatibility?8:4)+dataLen,
522 0,(struct sockaddr *)dest,sizeof(*dest));
523 if (bcast==-1) return (i<8?-1:i-8);
528 /* Here we will receive new packet to the given buffer. Both formats of packets
529 * are supported, we fallback to old format when first obsolete packet is seen.
530 * If the (valid) packet is received from unknown host, we will add it to our
531 * broadcasting list. FIXME: For now such autoconfigured hosts are NEVER removed.
534 static int ipx_udp_ReceivePacket(ipx_socket_t *s, char *outbuf, int outbufsize,
535 struct ipx_recv_data *rd) {
537 struct sockaddr_in fromaddr;
538 int fromaddrsize=sizeof(fromaddr);
539 unsigned short ports;
543 if ((size=recvfrom(s->fd,outbuf,outbufsize,0,(struct sockaddr *)&fromaddr,&fromaddrsize))<0)
546 printf(MSGHDR "recvfrom((%d-8=%d),",size,size-8);
550 if (fromaddr.sin_family!=AF_INET) return -1;
551 if (size<4) return -1;
552 if (memcmp(outbuf+0,D1Xid,2)) {
553 if (size<8 || memcmp(outbuf+0,D1Xudp,6)) return -1;
554 if (!compatibility) {
556 fputs(MSGHDR "Received obsolete packet from ",stdout);
558 puts(", upgrade that machine.\n" MSGHDR "Turning on compatibility mode...");
564 /* Lace: (dst_socket & src_socket) should be network-byte-order by comment in include/ipx_drv.h */
565 /* This behaviour presented here is broken. It is not used anywhere, so why bother? */
566 rd->src_socket = ntohs(*(unsigned short *)(outbuf+offs));
567 if (rd->src_socket != s->socket) {
569 msg(" - pkt was dropped (dst=%d,my=%d)",rd->src_socket,s->socket);
573 rd->dst_socket = s->socket;
575 // check if we already have sender of this packet in broadcast list
576 for (i=0;i<broadnum;i++) {
578 if (addreq(fromaddr,broads[i])) break;
581 if (fromaddr.sin_port==broads[i].sin_port
582 &&( fromaddr.sin_addr.s_addr & broadmasks[i].sin_addr.s_addr)
583 ==(broads[i].sin_addr.s_addr & broadmasks[i].sin_addr.s_addr)) break;
586 if (i>=broadnum) { // we don't have sender of this packet in our broadcast list
588 broads[broadnum++]=fromaddr;
589 fputs(MSGHDR "Adding host ",stdout);
591 puts(" to broadcasting address list");
594 memmove(outbuf,outbuf+offs+2,size-(offs+2));
597 memcpy(rd->src_node+0,&fromaddr.sin_addr,4);
598 ports=htons(ntohs(fromaddr.sin_port)-UDP_BASEPORT);
599 memcpy(rd->src_node+4,&ports,2);
600 memset(rd->src_network, 0, 4);
603 printf(MSGHDR "ReceivePacket: size=%d,from=",size);
604 dumpraddr(rd->src_node);
611 struct ipx_driver ipx_udp = {
612 ipx_udp_GetMyAddress,
616 ipx_udp_ReceivePacket,
617 ipx_general_PacketReady,
618 NULL, // InitNetgameAuxData
619 NULL, // HandleNetgameAuxData
620 NULL, // HandleLeaveGame
621 NULL // SendGamePacket