int main(int argc, char **argv) {
int r;
assert(argc==7);
endaddr(&us,argv,1);
endaddr(&them,argv,4);
static const uint8_t mprefix[]={
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x01,
0x01, 0x01, 0x01, 0x01,
};
static const uint8_t msuffix[]={
/* our nonce, fixed he he */
0x8d, 0xf0, 0x3f, 0x35, 0xd6, 0xc8, 0x1f, 0xc0
};
int msglen= (sizeof(mprefix) +
2+strlen(us.name) +
2+strlen(them.name) +
sizeof(msuffix));
uint8_t msg[msglen];
uint8_t *msgp=msg;
#define PREFIXSUFFIX(prefixsuffix) do { \
memcpy(msgp,prefixsuffix,sizeof(prefixsuffix)); \
msgp += sizeof(prefixsuffix); \
}while(0)
PREFIXSUFFIX(mprefix);
endname(&msgp,&us);
endname(&msgp,&them);
PREFIXSUFFIX(msuffix);
assert(msgp == msg+msglen);
struct protoent *proto=getprotobyname("udp");
int fd=socket(AF_INET, SOCK_DGRAM, proto->p_proto);
r=bind(fd,&us.sa,sizeof(us.sin)); if (r) { perror("bind us2"); exit(1); }
for (;;) {
r=sendto(fd,msg,msglen,0,&them.sa,sizeof(them.sin));
if (r < 0) perror("sendto");
r=getchar();
if (r==EOF) {
if (ferror(stdin)) { perror("getchar"); exit(1); }
break;
}
if (r!='\n')
break;
}
exit(0);
}
init_in()
{
int p;
for (p = endaddr(); p < KERNENTRY; p += sizeof (int)) {
if (*(int *)p != ENTRY ||
*(int *)(p + sizeof (int)) != 0 ||
*(int *)(p + sizeof (int) * 2) != 0)
continue;
p += sizeof (int) * 3;
if (bcmp((char *)p, magic, MAGICSIZE) == 0) {
kern_len = *(int *)(p + MAGICSIZE);
bcopy((char *)(p + MAGICSIZE + KERNLENSIZE),
(char *)KERNENTRY, kern_len);
break;
}
}
}
void
init_in()
{
int p;
for (p = endaddr(); p < KERNENTRY; p += sizeof (int)) {
if (*(int *)p != BEBOX_ENTRY ||
*(int *)(p + sizeof (int)) != 0 ||
*(int *)(p + sizeof (int) * 2) != 0)
continue;
p += sizeof (int) * 3;
if (memcmp((char *)p, bebox_magic, BEBOX_MAGICSIZE) == 0) {
kern_len = *(int *)(p + BEBOX_MAGICSIZE);
memcpy((char *)KERNENTRY,
(char *)(p + BEBOX_MAGICSIZE + KERNLENSIZE),
kern_len);
break;
}
}
}