/* sim_ether.c: OS-dependent network routines ------------------------------------------------------------------------------ Copyright (c) 2002-2004, 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. ------------------------------------------------------------------------------ Supported/Tested Platforms: Windows(NT,2K,XP,2K3) WinPcap V3.0+ Linux libpcap at least 0.9 OpenBSD,FreeBSD,NetBSD libpcap at least 0.9 MAC OS/X libpcap at least 0.9 Solaris Sparc libpcap at least 0.9 Solaris Intel libpcap at least 0.9 AIX ?? HP/UX ?? Compaq Tru64 Unix ?? VMS Alpha/Itanium VMS only, needs VMS libpcap WinPcap is available from: http://winpcap.polito.it/ libpcap for VMS is available from: http://simh.trailing-edge.com/sources/vms-pcap.zip libpcap for other Unix platforms is available at: Current Version: http://www.tcpdump.org/daily/libpcap-current.tar.gz Released Version: http://www.tcpdump.org/release/ Note: You can only use the released version if it is at least version 0.9 We've gotten the tarball, unpacked, built and installed it with: gzip -dc libpcap-current.tar.gz | tar xvf - cd libpcap-directory-name ./configure make make install Note: The "make install" step generally will have to be done as root. This will install libpcap in /usr/local/lib and /usr/local/include It is then important to make sure that you get the just installed libpcap components referenced during your build. This is generally achieved by invoking gcc with: -isystem /usr/local/include -L /usr/local/lib Note: Building for the platforms indicated above, with the indicated libpcap, should automatically leverage the appropriate mechanisms contained here. Things are structured so that it is likely to work for any other as yet untested platform. If it works for you, please let the author know so we can update the table above. If it doesn't work, then the following #define variables can influence the operation on an untested platform. USE_BPF - Determines if this code leverages a libpcap/WinPcap provided bpf packet filtering facility. All tested environments have bpf facilities that work the way we need them to. However a new one might not. undefine this variable to let this code do its own filtering. USE_SETNONBLOCK - Specifies whether the libpcap environment's non-blocking semantics are to be leveraged. This helps to manage the varying behaviours of the kernel packet facilities leveraged by libpcap. USE_READER_THREAD - Specifies that packet reading should be done in the context of a separate thread. The Posix threading APIs are used. This option is less efficient than the default non-threaded approach, but it exists since some platforms don't want to work with nonblocking libpcap semantics. OpenBSD and NetBSD either don't have pthread APIs available, or they are too buggy to be useful. Using the threaded approach may require special compile and/or link time switches (i.e. -lpthread or -pthread, etc.) Consult the documentation for your platform as needed. MUST_DO_SELECT - Specifies that when USE_READER_THREAD is active, that select() should be used to determin when available packets are ready for reading. Otherwise, we depend on the libpcap/kernel packet timeout specified on pcap_open_live. If USE_READER_THREAD is not set, then MUST_DO_SELECT is irrelevant NEED_PCAP_SENDPACKET - Specifies that you are using an older version of libpcap which doesn't provide a pcap_sendpacket API. NOTE: Changing these defines is done in either sim_ether.h OR on the global compiler command line which builds all of the modules included in a simulator. ------------------------------------------------------------------------------ Modification history: 25-Mar-04 MP Revised comments and minor #defines to deal with updated libpcap which now provides pcap_sendpacket on all platforms. 04-Feb-04 MP Returned success/fail status from eth_write to support determining if the current libpcap connection can successfully write packets. Added threaded approach to reading packets since this works better on some platforms (solaris intel) than the inconsistently implemented non-blocking read approach. 04-Feb-04 DTH Converted ETH_DEBUG to sim_debug 13-Jan-04 MP tested and fixed on OpenBSD, NetBS and FreeBSD. 09-Jan-04 MP removed the BIOCSHDRCMPLT ioctl() for OS/X 05-Jan-04 DTH Added eth_mac_scan 30-Dec-03 DTH Cleaned up queue routines, added no network support message 26-Dec-03 DTH Added ethernet show and queue functions from pdp11_xq 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; /*============================================================================*/ /* OS-independant ethernet routines */ /*============================================================================*/ t_stat eth_mac_scan (ETH_MAC* mac, char* strmac) { int i, j; short int num; char cptr[18]; int len = strlen(strmac); const ETH_MAC zeros = {0,0,0,0,0,0}; const ETH_MAC ones = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; ETH_MAC newmac; /* format of string must be 6 double-digit hex bytes with valid separators ideally, this mac scanner could allow more flexible formatting later */ if (len != 17) return SCPE_ARG; /* copy string to local storage for mangling */ strcpy(cptr, strmac); /* make sure byte separators are OK */ for (i=2; i> 8) ^ crcTable[ (crc ^ (*buf++)) & 0xFF ]; return(crc ^ mask); } void eth_packet_trace_ex(ETH_DEV* dev, const uint8 *msg, int len, char* txt, int dmp) { if (dev->dptr->dctrl & dev->dbit) { char src[20]; char dst[20]; unsigned short* proto = (unsigned short*) &msg[12]; uint32 crc = eth_crc32(0, msg, len); eth_mac_fmt((ETH_MAC*)&msg[0], dst); eth_mac_fmt((ETH_MAC*)&msg[6], src); sim_debug(dev->dbit, dev->dptr, "%s dst: %s src: %s proto: 0x%04X len: %d crc: %X\n", txt, dst, src, ntohs(*proto), len, crc); if (dmp) { int i, same, group, sidx, oidx; char outbuf[80], strbuf[18]; static char hex[] = "0123456789ABCDEF"; for (i=same=0; i 0) && (0 == memcmp(&msg[i], &msg[i-16], 16))) { ++same; continue; } if (same > 0) { sim_debug(dev->dbit, dev->dptr, "%04X thru %04X same as above\r\n", i-(16*same), i-1); same = 0; } group = (((len - i) > 16) ? 16 : (len - i)); for (sidx=oidx=0; sidx>4)&0xf]; outbuf[oidx++] = hex[msg[i+sidx]&0xf]; if (isprint(msg[i+sidx])) strbuf[sidx] = msg[i+sidx]; else strbuf[sidx] = '.'; } outbuf[oidx] = '\0'; strbuf[sidx] = '\0'; sim_debug(dev->dbit, dev->dptr, "%04X%-48s %s\r\n", i, outbuf, strbuf); } if (same > 0) sim_debug(dev->dbit, dev->dptr, "%04X thru %04X same as above\r\n", i-(16*same), len-1); } } } void eth_packet_trace(ETH_DEV* dev, const uint8 *msg, int len, char* txt) { eth_packet_trace_ex(dev, msg, len, txt, len > ETH_MAX_PACKET); } char* eth_getname(int number, char* name) { ETH_LIST list[ETH_MAX_DEVICE]; int count = eth_devices(ETH_MAX_DEVICE, 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 */ } t_stat eth_show (FILE* st, UNIT* uptr, int32 val, void* desc) { ETH_LIST list[ETH_MAX_DEVICE]; int number = eth_devices(ETH_MAX_DEVICE, list); fprintf(st, "ETH devices:\n"); if (number == -1) fprintf(st, " network support not available in simulator\n"); else if (number == 0) fprintf(st, " no network devices are available\n"); else { int i, min, len; for (i=0, min=0; i min) min = len; for (i=0; iitem) { size_t size = sizeof(struct eth_item) * max; que->max = max; que->item = malloc(size); if (que->item) { /* init dynamic memory */ memset(que->item, 0, size); } else { /* failed to allocate memory */ char* msg = "EthQ: failed to allocate dynamic queue[%d]\r\n"; printf(msg, max); if (sim_log) fprintf(sim_log, msg, max); return SCPE_MEM; }; }; return SCPE_OK; } void ethq_clear(ETH_QUE* que) { /* clear packet array */ memset(que->item, 0, sizeof(struct eth_item) * que->max); /* clear rest of structure */ que->count = que->head = que->tail = que->loss = que->high = 0; } void ethq_remove(ETH_QUE* que) { struct eth_item* item = &que->item[que->head]; if (que->count) { memset(item, 0, sizeof(struct eth_item)); if (++que->head == que->max) que->head = 0; que->count--; } } void ethq_insert(ETH_QUE* que, int32 type, ETH_PACK* pack, int32 status) { struct eth_item* item; /* if queue empty, set pointers to beginning */ if (!que->count) { que->head = 0; que->tail = -1; } /* find new tail of the circular queue */ if (++que->tail == que->max) que->tail = 0; if (++que->count > que->max) { que->count = que->max; /* lose oldest packet */ if (++que->head == que->max) que->head = 0; que->loss++; } if (que->count > que->high) que->high = que->count; /* set information in (new) tail item */ item = &que->item[que->tail]; item->type = type; item->packet.len = pack->len; item->packet.used = 0; memcpy(item->packet.msg, pack->msg, pack->len); item->packet.status = status; } /*============================================================================*/ /* Non-implemented versions */ /*============================================================================*/ #if !defined (USE_NETWORK) t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit) {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 -1;} #else /* endif unimplemented */ /*============================================================================*/ /* WIN32, Linux, and xBSD routines use WinPcap and libpcap packages */ /* OpenVMS Alpha uses a WinPcap port and an associated execlet */ /*============================================================================*/ #if defined (xBSD) && !defined(__APPLE__) #include #include #endif /* xBSD */ #include #include /* Some platforms have always had pcap_sendpacket */ #if defined(_WIN32) || defined(VMS) #define HAS_PCAP_SENDPACKET 1 #else /* The latest libpcap and WinPcap all have pcap_sendpacket */ #if !defined (NEED_PCAP_SENDPACKET) #define HAS_PCAP_SENDPACKET 1 #endif #endif #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, const 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 */ #if defined (USE_READER_THREAD) #include void eth_callback(u_char* info, const struct pcap_pkthdr* header, const u_char* data); static void * _eth_reader(void *arg) { ETH_DEV* volatile dev = (ETH_DEV*)arg; int status; struct timeval timeout; timeout.tv_sec = 0; timeout.tv_usec = 200*1000; sim_debug(dev->dbit, dev->dptr, "Reader Thread Starting\n"); while (dev->handle) { #if defined (MUST_DO_SELECT) int sel_ret; fd_set setl; FD_ZERO(&setl); FD_SET(pcap_get_selectable_fd((pcap_t *)dev->handle), &setl); sel_ret = select(1+pcap_get_selectable_fd((pcap_t *)dev->handle), &setl, NULL, NULL, &timeout); if (sel_ret < 0 && errno != EINTR) break; if (sel_ret > 0) { /* dispatch read request queue available packets */ status = pcap_dispatch((pcap_t*)dev->handle, -1, ð_callback, (u_char*)dev); } #else /* dispatch read request queue available packets */ status = pcap_dispatch((pcap_t*)dev->handle, 1, ð_callback, (u_char*)dev); #endif } sim_debug(dev->dbit, dev->dptr, "Reader Thread Exiting\n"); return NULL; } #endif t_stat eth_open(ETH_DEV* dev, char* name, DEVICE* dptr, uint32 dbit) { 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); /* save debugging information */ dev->dptr = dptr; dev->dbit = dbit; #if !defined(HAS_PCAP_SENDPACKET) && defined (xBSD) && !defined (__APPLE__) /* 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 (USE_READER_THREAD) { pthread_attr_t attr; ethq_init (&dev->read_queue, 200); /* initialize FIFO queue */ pthread_mutex_init (&dev->lock, NULL); pthread_attr_init(&attr); pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM); pthread_create (&dev->reader_thread, &attr, _eth_reader, (void *)dev); pthread_attr_destroy(&attr); } #else /* !defined (USE_READER_THREAD */ #ifdef USE_SETNONBLOCK /* 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 #endif /* !defined (USE_READER_THREAD */ return SCPE_OK; } t_stat eth_close(ETH_DEV* dev) { char* msg = "Eth: closed %s\r\n"; pcap_t *pcap; /* make sure device exists */ if (!dev) return SCPE_UNATT; /* close the device */ pcap = (pcap_t *)dev->handle; dev->handle = NULL; pcap_close(pcap); printf (msg, dev->name); if (sim_log) fprintf (sim_log, msg, dev->name); #if defined (USE_READER_THREAD) pthread_join (dev->reader_thread, NULL); #endif /* 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; struct timeval delay; /* 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; eth_filter(dev, 1, (ETH_MAC *)mac, 0, 0); /* send the packet */ status = eth_write (dev, &send, NULL); if (status != SCPE_OK) { char *msg; msg = "Eth: Error Transmitting packet: %s\r\n" "You may need to run as root, or install a libpcap version\r\n" "which is at least 0.9 from www.tcpdump.org\r\n"; printf(msg, strerror(errno)); if (sim_log) fprintf (sim_log, msg, strerror(errno)); return status; } /* if/when we have a sim_os_msleep() we'll use it here instead of this select() */ delay.tv_sec = 0; delay.tv_usec = 50*1000; select(0, NULL, NULL, NULL, &delay); /* make sure things settle into the read path */ /* empty the read queue and count the reflections */ 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); sim_debug(dev->dbit, dev->dptr, "Reflections = %d\n", dev->reflections); 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)) { eth_packet_trace (dev, packet->msg, packet->len, "writing"); /* dispatch write request (synchronous; no need to save write info to dev) */ 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 ((status == 0) ? SCPE_OK : SCPE_IOERR); } void eth_callback(u_char* info, const struct pcap_pkthdr* header, const u_char* data) { ETH_DEV* dev = (ETH_DEV*) info; #ifdef USE_BPF int to_me = 1; #else /* !USE_BPF */ int to_me = 0; int from_me = 0; int i; #ifdef ETH_DEBUG // eth_packet_trace (dev, data, header->len, "received"); #endif for (i = 0; i < dev->addr_count; i++) { if (memcmp(data, dev->filter_address[i], 6) == 0) to_me = 1; if (memcmp(&data[6], dev->filter_address[i], 6) == 0) from_me = 1; } /* all multicast mode? */ if (dev->all_multicast && (data[0] & 0x01)) to_me = 1; /* promiscuous mode? */ if (dev->promiscuous) to_me = 1; #endif /* USE_BPF */ /* 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; } #ifndef USE_BPF else from_me = 0; #endif } #ifdef USE_BPF if (to_me) { #else /* !USE_BPF */ if (to_me && !from_me) { #endif #if defined (USE_READER_THREAD) ETH_PACK tmp_packet; /* set data in passed read packet */ tmp_packet.len = header->len; memcpy(tmp_packet.msg, data, header->len); eth_packet_trace (dev, tmp_packet.msg, tmp_packet.len, "rcvqd"); pthread_mutex_lock (&dev->lock); ethq_insert(&dev->read_queue, 2, &tmp_packet, 0); pthread_mutex_unlock (&dev->lock); #else /* set data in passed read packet */ dev->read_packet->len = header->len; memcpy(dev->read_packet->msg, data, header->len); eth_packet_trace (dev, dev->read_packet->msg, dev->read_packet->len, "reading"); /* call optional read callback function */ if (dev->read_callback) (dev->read_callback)(0); #endif } } 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; #if !defined (USE_READER_THREAD) /* 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)); #else /* USE_READER_THREAD */ status = 0; pthread_mutex_lock (&dev->lock); if (dev->read_queue.count > 0) { ETH_ITEM* item = &dev->read_queue.item[dev->read_queue.head]; packet->len = item->packet.len; memcpy(packet->msg, item->packet.msg, packet->len); if (routine) routine(status); ethq_remove(&dev->read_queue); } pthread_mutex_unlock (&dev->lock); #endif 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]; char mac[20]; char* buf2; t_stat status; #ifdef USE_BPF struct bpf_program bpf; char* msg; #endif /* 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; /* set new filter addresses */ for (i = 0; i < addr_count; i++) memcpy(dev->filter_address[i], addresses[i], sizeof(ETH_MAC)); dev->addr_count = addr_count; /* store other flags */ dev->all_multicast = all_multicast; dev->promiscuous = promiscuous; /* print out filter information if debugging */ if (dev->dptr->dctrl & dev->dbit) { sim_debug(dev->dbit, dev->dptr, "Filter Set\n"); for (i = 0; i < addr_count; i++) { char mac[20]; eth_mac_fmt(&dev->filter_address[i], mac); sim_debug(dev->dbit, dev->dptr, " Addr[%d]: %s\n", i, mac); } if (dev->all_multicast) sim_debug(dev->dbit, dev->dptr, "All Multicast\n"); if (dev->promiscuous) sim_debug(dev->dbit, dev->dptr, "Promiscuous\n"); } /* 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; } } } sim_debug(dev->dbit, dev->dptr, "BPF string is: |%s|\n", buf); /* get netmask, which is required for compiling */ if (pcap_lookupnet(dev->handle, &bpf_subnet, &bpf_netmask, errbuf)<0) { bpf_netmask = 0; } #ifdef USE_BPF /* 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 { #ifdef USE_SETNONBLOCK /* set file non-blocking */ status = pcap_setnonblock (dev->handle, 1, errbuf); #endif /* USE_SETNONBLOCK */ } pcap_freecode(&bpf); } #endif /* USE_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. 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) { pcap_t* conn; int i, j, datalink; char errbuf[PCAP_ERRBUF_SIZE]; for (i=0; inext) { 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); } #endif /* 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 */