doom-ios/code/prboom/d_ipxgate.c

291 lines
6.7 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <netipx/ipx.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "protocol.h"
#define BACKUPTICS 12
#define NCMD_EXIT 0x80000000
#define NCMD_RETRANSMIT 0x40000000
#define NCMD_SETUP 0x20000000
#define NCMD_KILL 0x10000000 // kill game
#define NCMD_CHECKSUM 0x0fffffff
typedef struct
{
short gameid; // so multiple games can setup at once
short drone;
short nodesfound;
short nodeswanted;
} setupdata_t;
typedef struct
a
{
// High bit is retransmit request.
unsigned checksum;
// Only valid if NCMD_RETRANSMIT.
byte retransmitfrom;
byte starttic;
byte player;
byte numtics;
ticcmd_t cmds[BACKUPTICS];
} doomdata_t;
typedef struct
{
signed int tic;
union altu {
setupdata_t s;
unsigned char data[100];
doomdata_t d;
} u;
} ipxpacket_t;
int nodes;
unsigned short port = 0x869b;
int ipx_socket(void) {
int s = socket(PF_IPX,SOCK_DGRAM,0);
struct sockaddr_ipx sa;
if (s == -1) {
fprintf(stderr,"socket(PF_PIPX): %s\n",strerror(errno));
exit(-1);
}
memset(&sa,0,sizeof(sa));
memset(sa.sipx_node,0xff,sizeof(sa.sipx_node));
sa.sipx_port = htons(port);
if (bind(s,(struct sockaddr*)&sa,sizeof(sa)) == -1) {
fprintf(stderr,"bind(%d): %s\n",port,strerror(errno));
exit(-1);
}
return s;
}
int udp_socket(const char* ip) {
struct sockaddr_in sa;
int s = socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP);
if (s == -1) {
fprintf(stderr,"socket(PF_INET): %s\n", strerror(errno));
exit(-1);
}
sa.sin_family=PF_INET;
inet_aton(ip,&sa.sin_addr);
sa.sin_port = htons(5030);
if (connect(s,(struct sockaddr*)&sa,sizeof sa) == -1) {
fprintf(stderr,"connect(%s:%d): %s\n", ip, 5030, strerror(errno));
exit(-1);
}
return s;
}
static byte ChecksumPacket(const packet_header_t* buffer, size_t len)
{
const byte* p = (void*)buffer;
byte sum = 0;
if (len==0)
return 0;
while (p++, --len)
sum += *p;
return sum;
}
//
// Checksum
//
unsigned NetbufferChecksum (void* p, size_t l)
{
unsigned c;
c = 0x1234567;
l = l/4;
for (int i=0 ; i<l ; i++)
c += ((unsigned *)p)[i] * (i+1);
return c & NCMD_CHECKSUM;
}
int ipxs, udps;
int consoleplayer;
int basetic;
int ExpandTics (int low, int maketic)
{
int delta;
delta = low - (maketic&0xff);
if (delta >= -64 && delta <= 64)
return (maketic&~0xff) + low;
if (delta > 64)
return (maketic&~0xff) - 256 + low;
if (delta < -64)
return (maketic&~0xff) + 256 + low;
fprintf(stderr,"ExpandTics strange value %i at maketic %i\n",low,maketic);
exit(-2);
}
void send_udp_packet(enum packet_type_e type, unsigned tic, void* data, size_t len) {
packet_header_t* p = calloc(sizeof(packet_header_t)+len+1,1);
p->tic = doom_htonl(basetic = tic); p->type = type;
if (!data) {
data = (void*)&consoleplayer; len = 1;
}
memcpy(((char*)p)+sizeof(*p),data,len);
p->checksum = ChecksumPacket(p,sizeof(packet_header_t)+len);
write(udps,p,sizeof(packet_header_t)+len+1);
}
int connected;
int ipxcounter;
void ipx_receive(int s) {
ipxpacket_t buf;
int rc;
struct sockaddr from;
size_t sl = sizeof(from);
rc = recvfrom(s,&buf,sizeof buf,0,&from,&sl);
if (rc == -1) {
fprintf(stderr,"read(ipx): %s\n", strerror(errno));
exit(-2);
}
if (rc > 0) {
if (buf.tic == -1) {
// Setup packet
if (!connected++) {
connect(s,&from,sl);
send_udp_packet(PKT_INIT,0,NULL,0);
}
} else {
if (buf.u.d.checksum & NCMD_SETUP) {
printf("setup packet, dropped\n");
} else if (buf.u.d.checksum & NCMD_EXIT) {
send_udp_packet(PKT_QUIT,buf.u.d.starttic,NULL,0);
exit(0);
} else if ((buf.u.d.checksum & NCMD_CHECKSUM) == buf.u.d.checksum) {
// No flags, normal game packet
char outbuf[100];
int tics;
outbuf[0] = tics = buf.u.d.numtics;
outbuf[1] = buf.u.d.player;
for (int i=0; i< tics; i++)
TicToRaw(outbuf+2+i*sizeof(ticcmd_t),&buf.u.d.cmds[i]);
send_udp_packet(PKT_TICC, ExpandTics(buf.u.d.starttic, basetic), outbuf, 2+tics*sizeof(ticcmd_t));
}
}
}
}
void udp_receive(int s) {
size_t len = 1024;
packet_header_t *p = malloc(len);
int rc;
rc = read(s,p,len);
if (rc < 0) {
fprintf(stderr,"read(udp): %s\n", strerror(errno));
exit(-2);
}
if (rc > 0) {
switch (p->type) {
case PKT_SETUP:
{
struct setup_packet_s *sinfo = (void*)(p+1);
consoleplayer = sinfo->yourplayer;
send_udp_packet(PKT_GO,0,NULL,0);
write(ipxs,"\xff\xff\xff\xff\x00\x00\x00\x00\x02\x00\x02\x00\x00\x00\x00\x00",16);
}
break;
case PKT_GO:
{
ipxpacket_t pkt;
memset(&pkt,0,sizeof(pkt));
pkt.tic = ipxcounter++;
pkt.u.d.player = consoleplayer^1;
pkt.u.d.starttic = 0;
pkt.u.d.numtics = 0;
pkt.u.d.retransmitfrom = 0;
pkt.u.d.checksum = NetbufferChecksum(&pkt.u.d.retransmitfrom, 4);
write(ipxs,&pkt,16);
}
break;
case PKT_TICS:
{
ipxpacket_t pkt;
int tic = doom_ntohl(p->tic);
byte *pp = (void*)(p+1);
int tics = *pp++;
memset(&pkt,0,sizeof(pkt));
size_t len;
pkt.tic = ipxcounter++;
pkt.u.d.starttic = tic;
pkt.u.d.player = (consoleplayer == 0 ? 1 : 0);
pkt.u.d.numtics = tics;
for (int t=0; t<tics; t++) {
int players = *pp++;
for (int i=0; i<players; i++) {
if (*pp++ == pkt.u.d.player)
RawToTic(&pkt.u.d.cmds[t],pp);
pp += sizeof(ticcmd_t);
}
}
pkt.u.d.retransmitfrom = 0;
len = 12+tics*sizeof(ticcmd_t);
len = (len+7)&0xff8; // round up to next 16
pkt.u.d.checksum = NetbufferChecksum(&pkt.u.d.retransmitfrom, len-8);
write(ipxs,&pkt,len);
}
}
}
}
void loop(int ipxs, int udps) {
for (;;) {
struct timeval wt = {60,0};
fd_set fds;
int rc;
FD_ZERO(&fds);
FD_SET(ipxs,&fds);
FD_SET(udps,&fds);
rc = select(ipxs+udps,&fds,NULL,NULL,&wt);
if (rc < 0) {
fprintf(stderr,"select: %s\n", strerror(errno));
exit(-2);
}
if (rc>0) {
if (FD_ISSET(ipxs,&fds))
ipx_receive(ipxs);
if (FD_ISSET(udps,&fds))
udp_receive(udps);
}
}
}
int main(int argc, char**argv) {
ipxs = ipx_socket();
udps = udp_socket(argv[1]);
loop(ipxs,udps);
return 0;
}