/* sim_ether.c: OS-dependent network routines ------------------------------------------------------------------------------ Copyright (c) 2002-2003, David T. Hittner Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Except as contained in this notice, the name of the author shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the author. ------------------------------------------------------------------------------ This ethernet simulation is based on the PCAP and WinPcap packages. PCAP/WinPcap was chosen as the basis for network code since it is the most "universal" of the various network packages available. Using this style has allowed rapid network development for the major SIMH platforms. Developing a network package specifically for SIMH was rejected due to the time required; the advantage would be a more easily compiled and integrated code set. There are various problems associated with use of ethernet networking, which would be true regardless of the network package used, since there are no universally accepted networking methods. The most serious of these is getting the proper networking package loaded onto the system, since most environments do not come with the network interface packages loaded. The second most serious network issue relates to security. The network simulation needs to simulate operating system level functionality (packet driving). However, the host network programming interfaces tend to operate at the user level of functionality, so getting to the full functionality of the network interface usually requires that the person executing the network code be a privileged user of the host system. See the PCAP/WinPcap documentation for the appropriate host platform if unprivileged use of networking is needed - there may be known workarounds. ------------------------------------------------------------------------------ Modification history: 15-Dec-03 MP polished generic libpcap support. 05-Dec-03 DTH Genericized eth_devices() and #ifdefs 03-Dec-03 MP Added Solaris support 02-Dec-03 DTH Corrected decnet fix to use reflection counting 01-Dec-03 DTH Added BPF source filtering and reflection counting 28-Nov-03 DTH Rewrote eth_devices using universal pcap_findalldevs() 25-Nov-03 DTH Verified DECNET_FIX, reversed ifdef to mainstream code 19-Nov-03 MP Fixed BPF functionality on Linux/BSD. 17-Nov-03 DTH Added xBSD simplification 14-Nov-03 DTH Added #ifdef DECNET_FIX for problematic duplicate detection code 13-Nov-03 DTH Merged in __FreeBSD__ support 21-Oct-03 MP Added enriched packet dumping for debugging 20-Oct-03 MP Added support for multiple ethernet devices on VMS 20-Sep-03 Ankan Add VMS support (Alpha only) 29-Sep-03 MP Changed separator character in eth_fmt_mac to be ":" to format ethernet addresses the way the BPF compile engine wants to see them. Added BPF support to filter packets Added missing printf in eth_close 07-Jun-03 MP Added WIN32 support for DECNET duplicate address detection. 06-Jun-03 MP Fixed formatting of Ethernet Protocol Type in eth_packet_trace 30-May-03 DTH Changed WIN32 to _WIN32 for consistency 07-Mar-03 MP Fixed Linux implementation of PacketGetAdapterNames to also work on Red Hat 6.2-sparc and Debian 3.0r1-sparc. 03-Mar-03 MP Changed logging to be consistent on stdout and sim_log 01-Feb-03 MP Changed type of local variables in eth_packet_trace to conform to the interface needs of eth_mac_fmt wich produces char data instead of unsigned char data. Suggested by the DECC compiler. 15-Jan-03 DTH Corrected PacketGetAdapterNames parameter2 datatype 26-Dec-02 DTH Merged Mark Pizzolato's enhancements with main source Added networking documentation Changed _DEBUG to ETH_DEBUG 20-Dec-02 MP Added display of packet CRC to the eth_packet_trace. This helps distinguish packets with identical lengths and protocols. 05-Dec-02 MP With the goal of draining the input buffer more rapidly changed eth_read to call pcap_dispatch repeatedly until either a timeout returns nothing or a packet allowed by the filter is seen. This more closely reflects how the pcap layer will work when the filtering is actually done by a bpf filter. 31-Oct-02 DTH Added USE_NETWORK conditional Reworked not attached test Added OpenBSD support (from Federico Schwindt) Added ethX detection simplification (from Megan Gentry) Removed sections of temporary code Added parameter validation 23-Oct-02 DTH Beta 5 released 22-Oct-02 DTH Added all_multicast and promiscuous support Fixed not attached behavior 21-Oct-02 DTH Added NetBSD support (from Jason Thorpe) Patched buffer size to make sure entire packet is read in Made 'ethX' check characters passed as well as length Corrected copyright again 16-Oct-02 DTH Beta 4 released Corrected copyright 09-Oct-02 DTH Beta 3 released Added pdp11 write acceleration (from Patrick Caulfield) 08-Oct-02 DTH Beta 2 released Integrated with 2.10-0p4 Added variable vector and copyrights 04-Oct-02 DTH Added linux support (from Patrick Caulfield) 03-Oct-02 DTH Beta version of xq/sim_ether released for SIMH 2.09-11 24-Sep-02 DTH Finished eth_devices, eth_getname 18-Sep-02 DTH Callbacks implemented 13-Sep-02 DTH Basic packet read/write written 20-Aug-02 DTH Created Sim_Ether for O/S independant ethernet implementation ------------------------------------------------------------------------------ */ #include #include "sim_ether.h" #include "sim_sock.h" extern FILE *sim_log; /* make common BSD code a bit easier to read in this file */ /* OS/X seems to define and compile using one of these BSD types */ #if defined(__NetBSD__) || defined (__OpenBSD__) || defined (__FreeBSD__) #define xBSD 1 #endif /* make common winpcap code a bit easier to read in this file */ #if defined(_WIN32) || defined(VMS) #define WIN_PCAP 1 #define HAS_PCAP_SENDPACKET 1 #define PCAP_READ_TIMEOUT -1 #else #define PCAP_READ_TIMEOUT 1 #endif /*============================================================================*/ /* OS-independant ethernet routines */ /*============================================================================*/ void eth_mac_fmt(ETH_MAC* mac, char* buff) { uint8* m = (uint8*) mac; sprintf(buff, "%02X:%02X:%02X:%02X:%02X:%02X", m[0], m[1], m[2], m[3], m[4], m[5]); return; } static const uint32 crcTable[256] = { 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65, 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F, 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D, 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D }; uint32 eth_crc32(uint32 crc, const void* vbuf, size_t len) { const uint32 mask = 0xFFFFFFFF; const unsigned char* buf = (const unsigned char*)vbuf; crc ^= mask; while (0 != len--) crc = (crc >> 8) ^ crcTable[ (crc ^ (*buf++)) & 0xFF ]; return(crc ^ mask); } void eth_packet_trace_ex(ETH_PACK* packet, char* msg, int dmp) { char src[20]; char dst[20]; unsigned short* proto = (unsigned short*) &packet->msg[12]; uint32 crc = eth_crc32(0, packet->msg, packet->len); eth_mac_fmt((ETH_MAC*)&packet->msg[0], dst); eth_mac_fmt((ETH_MAC*)&packet->msg[6], src); printf("Eth: %s dst: %s src: %s proto: 0x%04X len: %d crc: %X\r\n", msg, dst, src, ntohs(*proto), packet->len, crc); if (dmp) { int i, same, group, sidx, oidx; char outbuf[80], strbuf[18]; static char hex[] = "0123456789ABCDEF"; for (i=same=0; ilen; i += 16) { if ((i > 0) && (0 == memcmp(&packet->msg[i], &packet->msg[i-16], 16))) { ++same; continue; } if (same > 0) { printf("%04X thru %04X same as above\r\n", i-(16*same), i-1); same = 0; } group = (((packet->len - i) > 16) ? 16 : (packet->len - i)); for (sidx=oidx=0; sidxmsg[i+sidx]>>4)&0xf]; outbuf[oidx++] = hex[packet->msg[i+sidx]&0xf]; if (isprint(packet->msg[i+sidx])) strbuf[sidx] = packet->msg[i+sidx]; else strbuf[sidx] = '.'; } outbuf[oidx] = '\0'; strbuf[sidx] = '\0'; printf("%04X%-48s %s\r\n", i, outbuf, strbuf); } if (same > 0) printf("%04X thru %04X same as above\r\n", i-(16*same), packet->len-1); } } void eth_packet_trace(ETH_PACK* packet, char* msg) { eth_packet_trace_ex(packet, msg, packet->len > 1514); } char* eth_getname(int number, char* name) { #define ETH_SUPPORTED_DEVICES 10 ETH_LIST list[ETH_SUPPORTED_DEVICES]; int count = eth_devices(ETH_SUPPORTED_DEVICES, list); if (count < number) return 0; strcpy(name, list[number].name); return name; } void eth_zero(ETH_DEV* dev) { /* set all members to NULL OR 0 */ memset(dev, 0, sizeof(ETH_DEV)); dev->reflections = -1; /* not established yet */ } /*============================================================================*/ /* Non-implemented versions */ /*============================================================================*/ #if !defined (USE_NETWORK) t_stat eth_open (ETH_DEV* dev, char* name) {return SCPE_NOFNC;} t_stat eth_close (ETH_DEV* dev) {return SCPE_NOFNC;} t_stat eth_write (ETH_DEV* dev, ETH_PACK* packet, ETH_PCALLBACK routine) {return SCPE_NOFNC;} t_stat eth_read (ETH_DEV* dev, ETH_PACK* packet, ETH_PCALLBACK routine) {return SCPE_NOFNC;} t_stat eth_filter (ETH_DEV* dev, int addr_count, ETH_MAC* addresses, ETH_BOOL all_multicast, ETH_BOOL promiscuous) {return SCPE_NOFNC;} int eth_devices (int max, ETH_LIST* dev) {return 0;} #else /* endif unimplemented */ /*============================================================================*/ /* WIN32, Linux, and xBSD routines use WinPcap and libpcap packages */ /* OpenVMS Alpha uses a WinPcap port and an associated execlet */ /*============================================================================*/ #include #include #ifdef xBSD #include #endif /* xBSD */ #if !defined (HAS_PCAP_SENDPACKET) /* libpcap has no function to write a packet, so we need to implement pcap_sendpacket() for compatibility with the WinPcap base code. Return value: 0=Success, -1=Failure */ int pcap_sendpacket(pcap_t* handle, u_char* msg, int len) { #if defined (linux) return (send(pcap_fileno(handle), msg, len, 0) == len)? 0 : -1; #else return (write(pcap_fileno(handle), msg, len) == len)? 0 : -1; #endif /* linux */ } #endif /* !HAS_PCAP_SENDPACKET */ t_stat eth_open(ETH_DEV* dev, char* name) { const int bufsz = (BUFSIZ < ETH_MAX_PACKET) ? ETH_MAX_PACKET : BUFSIZ; char errbuf[PCAP_ERRBUF_SIZE]; char temp[1024]; char* savname = name; int num; char* msg; /* initialize device */ eth_zero(dev); /* translate name of type "ethX" to real device name */ if ((strlen(name) == 4) && (tolower(name[0]) == 'e') && (tolower(name[1]) == 't') && (tolower(name[2]) == 'h') && isdigit(name[3]) ) { num = atoi(&name[3]); savname = eth_getname(num, temp); } /* attempt to connect device */ memset(errbuf, 0, sizeof(errbuf)); dev->handle = (void*) pcap_open_live(savname, bufsz, ETH_PROMISC, PCAP_READ_TIMEOUT, errbuf); if (!dev->handle) { /* can't open device */ msg = "Eth: pcap_open_live error - %s\r\n"; printf (msg, errbuf); if (sim_log) fprintf (sim_log, msg, errbuf); return SCPE_OPENERR; } else { msg = "Eth: opened %s\r\n"; printf (msg, savname); if (sim_log) fprintf (sim_log, msg, savname); } /* save name of device */ dev->name = malloc(strlen(savname)+1); strcpy(dev->name, savname); #if defined (xBSD) /* Tell the kernel that the header is fully-formed when it gets it. This is required in order to fake the src address. */ { int one = 1; ioctl(pcap_fileno(dev->handle), BIOCSHDRCMPLT, &one); } #endif /* xBSD */ #if !defined (WIN_PCAP) /* set ethernet device non-blocking so pcap_dispatch() doesn't hang */ if (pcap_setnonblock (dev->handle, 1, errbuf) == -1) { msg = "Eth: Failed to set non-blocking: %s\r\n"; printf (msg, errbuf); if (sim_log) fprintf (sim_log, msg, errbuf); } #endif return SCPE_OK; } t_stat eth_close(ETH_DEV* dev) { char* msg = "Eth: closed %s\r\n"; /* make sure device exists */ if (!dev) return SCPE_UNATT; /* close the device */ pcap_close(dev->handle); printf (msg, dev->name); if (sim_log) fprintf (sim_log, msg, dev->name); /* clean up the mess */ free(dev->name); eth_zero(dev); return SCPE_OK; } t_stat eth_reflect(ETH_DEV* dev, ETH_MAC mac) { ETH_PACK send, recv; t_stat status; int i; /* build a packet */ memset (&send, 0, sizeof(ETH_PACK)); send.len = ETH_MIN_PACKET; /* minimum packet size */ memcpy(&send.msg[0], mac, sizeof(ETH_MAC)); /* target address */ memcpy(&send.msg[6], mac, sizeof(ETH_MAC)); /* source address */ send.msg[12] = 0x90; /* loopback packet type */ for (i=14; ireflections = 0; do { memset (&recv, 0, sizeof(ETH_PACK)); status = eth_read (dev, &recv, NULL); if (memcmp(send.msg, recv.msg, ETH_MIN_PACKET)== 0) dev->reflections++; } while (recv.len > 0); #ifdef ETH_DEBUG { char* msg = "Eth: reflections = %d\r\n"; printf (msg, dev->reflections); if (sim_log) fprintf (sim_log, msg, dev->reflections); } #endif return dev->reflections; } t_stat eth_write(ETH_DEV* dev, ETH_PACK* packet, ETH_PCALLBACK routine) { int status = 1; /* default to failure */ /* make sure device exists */ if (!dev) return SCPE_UNATT; /* make sure packet exists */ if (!packet) return SCPE_ARG; /* make sure packet is acceptable length */ if ((packet->len >= ETH_MIN_PACKET) && (packet->len <= ETH_MAX_PACKET)) { /* dispatch write request (synchronous; no need to save write info to dev) */ #ifdef ETH_DEBUG eth_packet_trace (packet, "writing"); #endif status = pcap_sendpacket((pcap_t*)dev->handle, (u_char*)packet->msg, packet->len); /* detect sending of decnet loopback packet */ if ((status == 0) && DECNET_SELF_FRAME(dev->decnet_addr, packet->msg)) dev->decnet_self_sent += dev->reflections; } /* if packet->len */ /* call optional write callback function */ if (routine) (routine)(status); return SCPE_OK; } void eth_callback(u_char* info, const struct pcap_pkthdr* header, const u_char* data) { ETH_DEV* dev = (ETH_DEV*) info; int to_me = 1; /* detect sending of decnet loopback packet */ if (DECNET_SELF_FRAME(dev->decnet_addr, data)) { /* lower reflection count - if already zero, pass it on */ if (dev->decnet_self_sent > 0) { dev->decnet_self_sent--; to_me = 0; } } if (to_me) { /* set data in passed read packet */ dev->read_packet->len = header->len; memcpy(dev->read_packet->msg, data, header->len); #ifdef ETH_DEBUG eth_packet_trace (dev->read_packet, "reading"); #endif /* call optional read callback function */ if (dev->read_callback) (dev->read_callback)(0); } } t_stat eth_read(ETH_DEV* dev, ETH_PACK* packet, ETH_PCALLBACK routine) { int status; /* make sure device exists */ if (!dev) return SCPE_UNATT; /* make sure packet exists */ if (!packet) return SCPE_ARG; /* set read packet */ dev->read_packet = packet; packet->len = 0; /* set optional callback routine */ dev->read_callback = routine; /* dispatch read request to either receive a filtered packet or timeout */ do { status = pcap_dispatch((pcap_t*)dev->handle, 1, ð_callback, (u_char*)dev); } while ((status) && (0 == packet->len)); return SCPE_OK; } t_stat eth_filter(ETH_DEV* dev, int addr_count, ETH_MAC* addresses, ETH_BOOL all_multicast, ETH_BOOL promiscuous) { int i; bpf_u_int32 bpf_subnet, bpf_netmask; char buf[110+66*ETH_FILTER_MAX]; char errbuf[PCAP_ERRBUF_SIZE]; struct bpf_program bpf; char mac[20]; char* buf2; char* msg; t_stat status; /* make sure device exists */ if (!dev) return SCPE_UNATT; /* filter count OK? */ if ((addr_count < 0) || (addr_count > ETH_FILTER_MAX)) return SCPE_ARG; else if (!addresses) return SCPE_ARG; /* clear filter array */ memset(dev->filter_address, 0, sizeof(dev->filter_address)); /* set new filter addresses */ for (i = 0; i < addr_count; i++) memcpy(dev->filter_address[i], addresses[i], sizeof(ETH_MAC)); /* store other flags */ dev->all_multicast = all_multicast; dev->promiscuous = promiscuous; #ifdef ETH_DEBUG printf("Eth: Filter Set\r\n"); for (i = 0; i < addr_count; i++) { char mac[20]; eth_mac_fmt(&dev->filter_address[i], mac); printf(" Addr[%d]: %s\r\n", i, mac); } printf("%s%s\r\n", dev->all_multicast ? " All Multicast\r\n" : "", dev->promiscuous ? " Promiscuous\r\n" : ""); #endif /* test reflections */ if (dev->reflections == -1) status = eth_reflect(dev, dev->filter_address[0]); /* setup BPF filters and other fields to minimize packet delivery */ strcpy(buf, ""); /* construct destination filters - since the real ethernet interface was set into promiscuous mode by eth_open(), we need to filter out the packets that our simulated interface doesn't want. */ if (!dev->promiscuous) { for (i = 0; i < addr_count; i++) { eth_mac_fmt(&dev->filter_address[i], mac); if (!strstr(buf, mac)) /* eliminate duplicates */ sprintf(&buf[strlen(buf)], "%s(ether dst %s)", (*buf) ? " or " : "", mac); } if (dev->all_multicast) sprintf(&buf[strlen(buf)], "%s(ether multicast)", (*buf) ? " or " : ""); } /* construct source filters - this prevents packets from being reflected back by systems where WinPcap and libpcap cause packet reflections. Note that some systems do not reflect packets at all. This *assumes* that the simulated NIC will not send out packets with multicast source fields. */ if ((addr_count > 0) && (dev->reflections > 0)) { if (strlen(buf) > 0) sprintf(&buf[strlen(buf)], " and "); sprintf (&buf[strlen(buf)], "not ("); buf2 = &buf[strlen(buf)]; for (i = 0; i < addr_count; i++) { if (dev->filter_address[i][0] & 0x01) continue; /* skip multicast addresses */ eth_mac_fmt(&dev->filter_address[i], mac); if (!strstr(buf2, mac)) /* eliminate duplicates */ sprintf(&buf2[strlen(buf2)], "%s(ether src %s)", (*buf2) ? " or " : "", mac); } sprintf (&buf[strlen(buf)], ")"); } /* When starting, DECnet sends out a packet with the source and destination addresses set to the same value as the DECnet MAC address. This packet is designed to find and help diagnose DECnet address conflicts. Normally, this packet would not be seen by the sender, only by the other machine that has the same DECnet address. If the ethernet subsystem is reflecting packets, DECnet will fail to start if it sees the reflected packet, since it thinks another system is using this DECnet address. We have to let these packets through, so that if another machine has the same DECnet address that we can detect it. Both eth_write() and eth_callback() help by checking the reflection count - eth_write() adds the reflection count to dev->decnet_self_sent, and eth_callback() check the value - if the dev->decnet_self_sent count is zero, then the packet has come from another machine with the same address, and needs to be passed on to the simulated machine. */ memset(dev->decnet_addr, 0, sizeof(ETH_MAC)); /* check for decnet address in filters */ if ((addr_count) && (dev->reflections > 0)) { for (i = 0; i < addr_count; i++) { eth_mac_fmt(&dev->filter_address[i], mac); if (memcmp(mac, "AA:00:04", 8) == 0) { memcpy(dev->decnet_addr, &dev->filter_address[i], sizeof(ETH_MAC)); /* let packets through where dst and src are the same as our decnet address */ sprintf (&buf[strlen(buf)], " or ((ether dst %s) and (ether src %s))", mac, mac); break; } } } #ifdef ETH_DEBUG msg = "Eth: BPF string is: |%s|\r\n"; printf (msg, buf); if (sim_log) fprintf (sim_log, msg, buf); #endif /* get netmask, which is required for compiling */ if (pcap_lookupnet(dev->handle, &bpf_subnet, &bpf_netmask, errbuf)<0) { bpf_netmask = 0; } /* compile filter string */ if ((status = pcap_compile(dev->handle, &bpf, buf, 1, bpf_netmask)) < 0) { sprintf(errbuf, "%s", pcap_geterr(dev->handle)); msg = "Eth: pcap_compile error: %s\r\n"; printf(msg, errbuf); if (sim_log) fprintf (sim_log, msg, errbuf); /* show erroneous BPF string */ msg = "Eth: BPF string is: |%s|\r\n"; printf (msg, buf); if (sim_log) fprintf (sim_log, msg, buf); } else { /* apply compiled filter string */ if ((status = pcap_setfilter(dev->handle, &bpf)) < 0) { sprintf(errbuf, "%s", pcap_geterr(dev->handle)); msg = "Eth: pcap_setfilter error: %s\r\n"; printf(msg, errbuf); if (sim_log) fprintf (sim_log, msg, errbuf); } else { #if !defined (WIN_PCAP) /* set file non-blocking */ status = pcap_setnonblock (dev->handle, 1, errbuf); #endif } pcap_freecode(&bpf); } return SCPE_OK; } /* The libpcap provided API pcap_findalldevs() on most platforms, will leverage the getifaddrs() API if it is available in preference to alternate platform specific methods of determining the interface list. A limitation of getifaddrs() is that it returns only interfaces which have associated addresses. This may not include all of the interesting interfaces that we are interested in since a host may have dedicated interfaces for a simulator, which is otherwise unused by the host. One could hand craft the the build of libpcap to specifically use alternate methods to implement pcap_findalldevs(). However, this can get tricky, and would then result in a sort of deviant libpcap. Additionally, we're really only interested in Ethernet LAN type interfaces here. It would be nice if the flags provided by pcap_if_t actually told us if an interface was a Point to Point or a LAN interface and if it was an ethernet. This isn't implemented anywhere. This routine exists to allow platform specific code to validate and/or extend the set of available interfaces to include any that are not returned by pcap_findalldevs. */ int eth_host_devices(int used, int max, ETH_LIST* list) { return used; } int eth_devices(int max, ETH_LIST* list) { pcap_if_t* alldevs; pcap_if_t* dev; int i; char errbuf[PCAP_ERRBUF_SIZE]; /* retrieve the device list */ if (pcap_findalldevs(&alldevs, errbuf) == -1) { char* msg = "Eth: error in pcap_findalldevs: %s\r\n"; printf (msg, errbuf); if (sim_log) fprintf (sim_log, msg, errbuf); } else { /* copy device list into the passed structure */ for (i=0, dev=alldevs; dev; dev=dev->next) { if ((dev->flags & PCAP_IF_LOOPBACK) || (!strcmp("any", dev->name))) continue; list[i].num = i; sprintf(list[i].name, "%s", dev->name); if (dev->description) sprintf(list[i].desc, "%s", dev->description); else sprintf(list[i].desc, "%s", "No description available"); if (i++ >= max) break; } /* free device list */ pcap_freealldevs(alldevs); } /* Add any host specific devices and/or validate those already found */ i = eth_host_devices(i, max, list); /* return device count */ return i; } #endif /* USE_NETWORK */