/* $Header: nip.c,v 1.7 89/05/11 14:27:15 mar Exp $ */ #include #include #include "ether.h" extern int cksum(); /* flags for the nipinfo structure: */ #define NI_NETADDR 0x01 #define NI_NETMASK 0x02 #define NI_BROADCAST 0x04 #define NI_LOWEST 0x08 #define NI_HIGHEST 0x10 #define NI_RECOMMEND 0x20 #define NI_GATEWAY 0x40 /* actual packet format */ struct nip_pkt { struct et_hdr np_et; /* with 2 bytes of pad at the front */ byte np_source[6]; unss np_checksum; unss np_opcode; unss np_version; unsl np_netaddress; unsl np_netmask; unsl np_broadcast; unsl np_lowest; unsl np_highest; unsl np_recommend; unsl np_gateway; }; /* Opcodes */ /* ethernet type code for NIP */ #ifdef BIG_ENDIAN #define ETHERTYPE_NIP 0x0801 #define NIP_REQUEST 1 #define NIP_RESPONSE 2 #define NIP_VERSION 1 #else #define ETHERTYPE_NIP 0x0108 #define NIP_REQUEST 0x100 #define NIP_RESPONSE 0x200 #define NIP_VERSION 0x100 #endif static struct nip_pkt pkt; static char in_buf[2+2048]; /* 2048 byte buffer (2 byte padding) */ struct nip_pkt *nip_get(addr) unsl addr; { register int i, j, len; register struct nip_pkt *ipkt = (struct nip_pkt *)in_buf; bzero(&pkt, sizeof(pkt)); etadcpy(etmyaddr, pkt.np_source); etadcpy(etmyaddr, pkt.np_et.et_src); etadcpy(etbroad, pkt.np_et.et_dst); #ifdef DEBUG printf("NIP\n"); #endif pkt.np_et.et_type = ETHERTYPE_NIP; pkt.np_opcode = NIP_REQUEST; pkt.np_version = NIP_VERSION; pkt.np_checksum = (unsigned short)~cksum(pkt.np_source, (sizeof (struct nip_pkt) - sizeof (struct et_hdr))>>1, 0); for (j = 0; j < 5; j++) { et_write (pkt.np_et.et_dst, sizeof(pkt)-2); for (i=0; i < 1000; i++) { if ((len = et_read (in_buf+2, 2048)) >= (sizeof (pkt) - 2)) { if ((ipkt->np_et.et_type != ETHERTYPE_NIP) || (ipkt->np_version != NIP_VERSION) || (ipkt->np_opcode != NIP_RESPONSE)) continue; if (ipkt->np_checksum && (unss)~cksum(&ipkt->np_source[0], (sizeof (struct nip_pkt) - sizeof (struct et_hdr))>>1, 0)) { continue; } goto got_reply; } } } #ifdef ATHENA_INSTALL printf("Unable to talk to any other machines, is the ethernet connected?\n"); #else printf("Timeout\n"); #endif return(0); got_reply: printf ("\nnetaddress "); print_ip_addr(ipkt->np_netaddress); printf ("\nnetmask "); print_ip_addr(ipkt->np_netmask); printf ("\nbroadcast "); print_ip_addr(ipkt->np_broadcast); printf ("\ngateway "); print_ip_addr(ipkt->np_gateway); printf ("\nlowest "); print_ip_addr(ipkt->np_lowest); printf ("\nhighest "); print_ip_addr(ipkt->np_highest); if (ipkt->np_recommend) { printf ("\nrecommend "); print_ip_addr(ipkt->np_recommend); } printf ("\n"); return (ipkt); } char eth[6]; nip_verify (address, defend) unsl address; int defend; { struct adr adr; struct adr *padr2 = (struct adr *)in_buf; int i, j, cc; #ifdef DEBUG printf("verifying address "); print_ip_addr(address); printf("\n"); #endif bzero (&adr, sizeof(adr)); etadcpy (etbroad, adr.ar_et.et_dst); etadcpy (etmyaddr, adr.ar_et.et_src); adr.ar_et.et_type = ETHER_ARP; adr.ar_hd = ETHER_HTYPE; adr.ar_pro = ETHER_IP; adr.ar_hln = ETHER_HLEN; adr.ar_pln = 4; adr.ar_op = ARP_REQ; etadcpy(etmyaddr, adr.ar_sha); ipadcpy (&address, adr.ar_tpa); if (defend) ipadcpy (&address, adr.ar_spa); for (i=0 ; i < 5; i++) { et_write (&adr.ar_et.et_dst[0], sizeof (struct adr)-2); for (j=0; j < 500; j++) { /* * We need to be able to answer our own ARP * requests, so we use net_read() after we * initialize our IP address. */ if (defend) cc = net_read (&padr2->ar_et.et_dst[0], sizeof(in_buf)-2); else cc = et_read (&padr2->ar_et.et_dst[0], sizeof(in_buf)-2); if (cc = 0) continue; if (padr2->ar_et.et_type != ETHER_ARP) continue; if (padr2->ar_op != ARP_REP) continue; if (bcmp(padr2->ar_spa, &address, 4)) continue; print_ip_addr(address); printf (" not verified\n"); return 0; } } #ifdef DEBUG printf("address not in use.\n"); #endif return 1; } nip_set_address(addr) long addr; { register struct nip_pkt *np; long address, low, high; long count = 0; extern long gateway; np = nip_get(addr); if (np == 0 && addr) { printf("No, NIP response, "); address = addr; /* Set network information based on the specified address */ gateway = net_mask = 0; switch((swabl(addr) & 0xE0000000)) { case 0xE0000000: printf("Address "); print_ip_addr(addr); printf(" is not a class A, B, or C network address\n"); break; /* Class C networks */ case 0xC0000000: net_mask = 0xFFFFFF00; break; /* Class B networks */ case 0xA0000000: case 0x80000000: net_mask = 0xFFFF0000; break; /* Class A networks */ default: switch ((unsb)(swabl(addr)>>24)) { case 18: net_mask = 0xFFFF0000; break; default: net_mask = 0xFF000000; break; } break; } goto gotit; } if (np == 0) { printf("Unable to find an address to use.\n"); return(1); } low = np->np_lowest; high = np->np_highest; net_mask = np->np_netmask; if (np->np_gateway) gateway = np->np_gateway; if (addr) { address = addr; if (addr & np->np_netmask != np->np_netaddress) { printf("Address "); print_ip_addr(addr); printf(" is not on this network!\n"); } else if (nip_verify(address, 0)) goto gotit; } if (np->np_recommend) { address = np->np_recommend; if (nip_verify (address, 0)) goto gotit; } lostit: low = swabl(low); high = swabl(high); for (; count < high - low; count++) { address = hash (etmyaddr, low, high, count); if (nip_verify (address, 0)) goto gotit; } printf("Unable to find an address to use.\n"); return(1); gotit: printf("IP address is "); print_ip_addr(address); printf("\n"); in_me = address; if (!nip_verify (address, 1)) { printf ("Somebody else did, too\n"); in_me = 0; goto lostit; } #ifdef DEBUG printf("On the air.\n"); #endif return(0); } hash(pa, low, high, x) byte *pa; long low, high; int x; { unsl tmp; /* * Hash based on the manufacturer-assigned * half of the ethernet address. */ tmp = pa[3] + x * pa[4] + pa[5]; if (pa[4] == 0) tmp += x; tmp %= high - low; return swabl(low + tmp); }