diff options
Diffstat (limited to 'pptpd-1.3.3/bcrelay.c')
| -rw-r--r-- | pptpd-1.3.3/bcrelay.c | 1014 |
1 files changed, 0 insertions, 1014 deletions
diff --git a/pptpd-1.3.3/bcrelay.c b/pptpd-1.3.3/bcrelay.c deleted file mode 100644 index b345795..0000000 --- a/pptpd-1.3.3/bcrelay.c +++ /dev/null @@ -1,1014 +0,0 @@ -// A broadcast packet repeater. This packet repeater (currently designed for -// udp packets) will listen for broadcast packets. -// When it receives the packets, it will then re-broadcast the packet. -// -// Written by TheyCallMeLuc(at)yahoo.com.au -// I accept no responsiblity for the function of this program if you -// choose to use it. -// Modified for Poptop by Richard de Vroede <r.devroede@linvision.com> -// Ditto on the no responsibility. -// -// Rewritten by Norbert van Bolhuis <norbert@vanbolhuis.demon.nl> bcrelay (v1.0+) -// now supports/does: -// 1) Relaying from PPP (VPN tunnel) interfaces, hereby creating a virtual -// LAN (w.r.t. UDP broadcasts) for VPN clients and ethernet PCs -// belonging/matching the subnet portion of the VPN IP addresses. -// So now broadcasting to/from all systems of the VPN has been implemented. -// Note that bcrelay v0.5 only relayed from LAN to VPN clients. -// It doesn't matter whether the systems on the VPN are on the LAN of the -// VPN server or have a VPN/PPTP connection (over the internet) to the VPN -// server. Broadcasts will always be relayed to/from all given interfaces. And -// as long as the subnet portion of the IP addresses of the systems on the VPN -// matches, the VPN server will be able to route properly. This means all -// networking applications/games that rely on a UDP broadcast from one or -// more PPP (VPN tunnel) interfaces will now see eachother and work over -// the VPN. -// Note that it depends on the networking application/game and whoever -// acts as application/game server/host who is sending (UPD) broadcasts -// and who is listening. -// 2) UDP broadcasts received on a PPP interface (VPN tunnel) sometimes -// don't carry the VPN IP address which pptpd provisioned. I've seen -// this happening on a WinXP SP1 box, especially when the application -// responsible for the UDP broadcasts isn't aware of the PPP interface. -// In this case it just uses the LAN IP src address for the IP src -// address of the inner (GRE encapsulated) IP packet. This breaks -// the "virtual LAN" and therefore bcrelay, as of this version, changes -// the src IP address to the VPN IP address (which pptpd provisioned) -// before relaying. -// 3) To avoid a UDP broadcast loop, bcrelay changes the IP TTL and the -// UDP checksum (to 1 and 0 respectively) of the UDP broadcasts it relays. -// No relaying will be done for UDP broadcasts with IP TTL=1 and UDP -// checksum=0. Could also (mis)use IP identification for this, but IP TTL -// and UDP chksum combination is expected to work fine. -// 4) bcrelay v0.5 forgot to update IP/UDP checksum when it changed the -// dest. IP address (e.g. from 192.168.1.255 to 255.255.255.255). -// Of course as of this version bcrelay always updates the IP/UDP -// checksum since the IP TTL and src IP address will change also. -// 5) Enhanced the (syslog) debugging capabilities. By default bcrelay will -// show what it is doing. Bcrelay will syslog the IP interfaces it tries -// to read/relay UDP broadcasts from/to. These interfaces are called -// the 'active interfaces', bcrelay will syslog the initial set of active -// interfaces and whenever the set changes. Currently there is no difference -// between an incoming interface (given with -i) and an outgoing interface -// (given with -o), so bcrelay won't show this attribute. Also, bcrelay will -// syslog a successfully relayed UDP broadcast, including the UDP port numbers, -// the incoming interface and the interface(s) to which it was successfully -// relayed. The (new) -n option allows to suppress syslog tracing. -// If -n is given, bcrelay shows/syslogs nothing, except fatal error -// messages. -// -// This software is completely free. You can use and/or modify this -// software to your hearts content. You are free to redistribute it as -// long as it is accompanied with the source and my credit is included. - -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif - -#ifdef __linux__ -#define _GNU_SOURCE 1 /* strdup() prototype, broken arpa/inet.h */ -#endif - -#ifdef __svr4__ -#define __EXTENSIONS__ 1 /* strdup() prototype */ -#endif - -#ifdef __sgi__ -#define _XOPEN_SOURCE 500 /* strdup() prototype */ -#endif - -#include <fcntl.h> -#include <stdio.h> -#include <stdlib.h> -#include <netdb.h> -#include <unistd.h> -#include <string.h> -#include <libgen.h> -#include <time.h> -#include <sys/time.h> -#include <regex.h> -#include <net/if.h> -#include <sys/ioctl.h> -#include <sys/socket.h> -#include <sys/types.h> -#include <netinet/in.h> -#include <netpacket/packet.h> -#include <net/ethernet.h> -#include <netinet/ip.h> -#include <netinet/udp.h> -#include <netinet/tcp.h> -#include <dirent.h> - -#include "defaults.h" -#include "our_syslog.h" -#include "our_getopt.h" - -//#define VERSION "1.0" - -/* uncomment if you compile this without poptop's configure script */ -//#define HAVE_FORK - -/* - * Value-return macros to fields in the IP PDU header - */ -#define IP_IPPDU_IHL(ippdu) (*(unsigned char *)(ippdu) & 0x0F) -#define IP_IPPDU_PROTO(ippdu) (*((unsigned char *)(ippdu) + 9) & 0xFF) - -/* - * Pointer macros to fields in the IP PDU header - */ -#define IP_IPPDU_CHECKSUM_MSB_PTR(ippdu) ((unsigned char *)(ippdu) + 10 ) -#define IP_IPPDU_CHECKSUM_LSB_PTR(ippdu) ((unsigned char *)(ippdu) + 11 ) - -/* - * Pointer macros to fields in the UDP PDU header - */ -#define IP_UDPPDU_CHECKSUM_MSB_PTR(udppdu) ((unsigned char *)(udppdu) + 6 ) -#define IP_UDPPDU_CHECKSUM_LSB_PTR(udppdu) ((unsigned char *)(udppdu) + 7 ) - -#define MAXIF 255 // Maximum interfaces to use -#define MAX_SELECT_WAIT 3 // Maximum time (in secs) to wait for input on the socket/interfaces - // A time-out triggers the discovery of new interfaces. -#define MAX_NODISCOVER_IFS 12 // Maximum time (in secs) to elaps before a discovery of new - // interfaces is triggered. Only when a packet keeps coming in - // (this prevents a select time-out) a variable initialized with - // this #define becomes 0 and a rediscovery of the interfaces is - // triggered. -#define MAX_IFLOGTOSTR 16 - -/* Local function prototypes */ -static void showusage(char *prog); -static void showversion(); -#ifndef HAVE_DAEMON -static void my_daemon(int argc, char **argv); -#endif -static void mainloop(int argc, char **argv); - -struct packet { - struct iphdr ip; - struct udphdr udp; - char data[ETHERMTU]; -}; - - -/* - * struct that keeps track of the interfaces of the system - * selected upon usage by bcrelay (with -i and -o option). - * An array of this struct is returned by discoverActiveInterfaces. - * This array is reset (filled from scratch) each time - * discoverActiveInterfaces is called. - */ -struct iflist { -//Fix 3mar2003 - //char index; - int index; - u_int32_t bcast; - char ifname[16+1]; - unsigned long ifaddr; - unsigned long ifdstaddr; - unsigned long flags1; -}; - -#define IFLIST_FLAGS1_IF_IS_ETH 0x00000001 -#define IFLIST_FLAGS1_IF_IS_PPP 0x00000002 -#define IFLIST_FLAGS1_IF_IS_UNKNOWN 0x00000004 -#define IFLIST_FLAGS1_CHANGED_INNER_SADDR 0x00010000 - - -/* - * struct that keeps track of the socket fd's for every interface - * that is in use (and thus present in iflist). - * Two permanent arrays of this struct are used, one for the - * previous/old list and one for the current list. - */ -struct ifsnr { - int sock_nr; - int ifindex; -}; - -static void copy_ifsnr(struct ifsnr *from, struct ifsnr *to); -static int find_sock_nr(struct ifsnr *l, int ifidx); -struct iflist *discoverActiveInterfaces(int s); -void ip_update_checksum(unsigned char *ippdu); -static char *IpProtToString( unsigned char prot ); -static char *iflistToString( struct iflist *ifp ); -static char *iflistLogIToString( struct iflist *ifp, int idx, struct ifsnr *ifnr ); -static char *iflistLogRToString( struct iflist *ifp, int idx, struct ifsnr *ifnr ); -static void bind_to_iface(int fd, int ifindex); - -/* - * This global variable determines whether NVBCR_PRINTF actually - * displays something. While developping v1.0, NVBCR_PRINTF were - * printf and a lot of tracing/logging/debugging was done with these. - * Of course, by default these 'info' messages have been turned off - * now. Enable by setting variable to 1. Note that output will only - * appear in non-daemon mode (see also NVBCR_PRINTF). - */ -static int do_org_info_printfs = 0; - -static int vnologging = 0; -static int vdaemon = 0; - -#define NVBCR_PRINTF( args ) \ - if ((vdaemon == 0) && (do_org_info_printfs == 1)) printf args - -static char interfaces[32]; -static char log_interfaces[MAX_IFLOGTOSTR*MAXIF]; -static char log_relayed[(MAX_IFLOGTOSTR-1)*MAXIF+81]; -static char *ipsec = ""; - -static void showusage(char *prog) -{ - printf("\nBCrelay v%s\n\n", VERSION); - printf("A broadcast packet repeater. This packet repeater (currently designed for udp packets) will listen\n"); - printf(" for broadcast packets. When it receives the packets, it will then re-broadcast the packet.\n\n"); - printf("Usage: %s [options], where options are:\n\n", prog); - printf(" [-d] [--daemon] Run as daemon.\n"); - printf(" [-h] [--help] Displays this help message.\n"); - printf(" [-i] [--incoming <ifin>] Defines from which interface broadcasts will be relayed.\n"); - printf(" [-n] [--nolog] No logging/tracing to /var/log/messages.\n"); - printf(" [-o] [--outgoing <ifout>] Defines to which interface broadcasts will be relayed.\n"); - printf(" [-s] [--ipsec <arg>] Defines an ipsec tunnel to be relayed to.\n"); - printf(" Since ipsec tunnels terminate on the same interface, we need to define the broadcast\n"); - printf(" address of the other end-point of the tunnel. This is done as ipsec0:x.x.x.255\n"); - printf(" [-v] [--version] Displays the BCrelay version number.\n"); - printf("\nLog messages and debugging go to syslog as DAEMON.\n\n"); - printf("\nInterfaces can be specified as regexpressions, ie. ppp[0-9]+\n\n"); -} - -static void showversion() -{ - printf("BCrelay v%s\n", VERSION); -} - -#ifndef HAVE_DAEMON -static void my_daemon(int argc, char **argv) -{ - pid_t pid; -#ifndef BCRELAY_BIN -/* Need a smart way to locate the binary -rdv */ -#define BCRELAY_BIN argv[0] -#endif -#ifndef HAVE_FORK - /* need to use vfork - eg, uClinux */ - char **new_argv; - extern char **environ; - int minusd=0; - int i; - int fdr; - - /* Strip -d option */ - new_argv = malloc((argc) * sizeof(char **)); - fdr = open("/dev/null", O_RDONLY); - new_argv[0] = BCRELAY_BIN; - for (i = 1; argv[i] != NULL; i++) { - if (fdr != 0) { dup2(fdr, 0); close(fdr); } - if ( (strcmp(argv[i],"-d")) == 0 ) { - minusd=1; - } - if (minusd) { - new_argv[i] = argv[i+1]; - } else { - new_argv[i] = argv[i]; - } - } - syslog(LOG_DEBUG, "Option parse OK, re-execing as daemon"); - fflush(stderr); - if ((pid = vfork()) == 0) { - if (setsid() < 0) { /* shouldn't fail */ - syslog(LOG_ERR, "Setsid failed!"); - _exit(1); - } - chdir("/"); - umask(0); - /* execve only returns on an error */ - execve(BCRELAY_BIN, new_argv, environ); - exit(1); - } else if (pid > 0) { - syslog(LOG_DEBUG, "Success re-execing as daemon!"); - exit(0); - } else { - syslog(LOG_ERR, "Error vforking"); - exit(1); - } -#else - pid=fork(); - if (pid<0) { syslog(LOG_ERR, "Error forking"); _exit(1); } - if (pid>0) { syslog(LOG_DEBUG, "Parent exits"); _exit(0); } - if (pid==0) { syslog(LOG_DEBUG, "Running as child"); } - /* child (daemon) continues */ - if (setsid() < 0) { /* shouldn't fail */ - syslog(LOG_ERR, "Setsid failed!"); - _exit(1); - } - chdir("/"); -#endif -} -#endif - -int main(int argc, char **argv) { - regex_t preg; - /* command line options */ - int c; - char *ifout = ""; - char *ifin = ""; - -#ifndef BCRELAY - fprintf(stderr, - "bcrelay: pptpd was compiled without support for bcrelay, exiting.\n" - " run configure --with-bcrelay, make, and install.\n"); - exit(1); -#endif - - /* open a connection to the syslog daemon */ - openlog("bcrelay", LOG_PID, PPTP_FACILITY); - - while (1) { - int option_index = 0; - - static struct option long_options[] = - { - {"nolog", 0, 0, 0}, - {"daemon", 0, 0, 0}, - {"help", 0, 0, 0}, - {"incoming", 1, 0, 0}, - {"outgoing", 1, 0, 0}, - {"ipsec", 1, 0, 0}, - {"version", 0, 0, 0}, - {0, 0, 0, 0} - }; - - c = getopt_long(argc, argv, "ndhi:o:s:v", long_options, &option_index); - if (c == -1) - break; - /* convert long options to short form */ - if (c == 0) - c = "ndhiosv"[option_index]; - switch (c) { - case 'n': - vnologging = 1; - break; - case 'd': - vdaemon = 1; - break; - case 'h': - showusage(argv[0]); - return 0; - case 'i': - ifin = strdup(optarg); - break; - case 'o': - ifout = strdup(optarg); - break; - case 's': - ipsec = strdup(optarg); - // Validate the ipsec parameters - regcomp(&preg, "ipsec[0-9]+:[0-9]+.[0-9]+.[0-9]+.255", REG_EXTENDED); - if (regexec(&preg, ipsec, 0, NULL, 0)) { - syslog(LOG_INFO,"Bad syntax: %s", ipsec); - fprintf(stderr, "\nBad syntax: %s\n", ipsec); - showusage(argv[0]); - return 0; - } else { - regfree(&preg); - break; - } - case 'v': - showversion(); - return 0; - default: - showusage(argv[0]); - return 1; - } - } - if (ifin == "") { - syslog(LOG_INFO,"Incoming interface required!"); - showusage(argv[0]); - _exit(1); - } - if (ifout == "" && ipsec == "") { - syslog(LOG_INFO,"Listen-mode or outgoing or IPsec interface required!"); - showusage(argv[0]); - _exit(1); - } else { - sprintf(interfaces,"%s|%s", ifin, ifout); - } - - // If specified, become Daemon. - if (vdaemon) { -#if HAVE_DAEMON - closelog(); - freopen("/dev/null", "r", stdin); - /* set noclose, we want stdout/stderr still attached if we can */ - daemon(0, 1); - /* returns to child only */ - /* pid will have changed */ - openlog("bcrelay", LOG_PID, PPTP_FACILITY); -#else /* !HAVE_DAEMON */ - my_daemon(argc, argv); - /* returns to child if !HAVE_FORK - * never returns if HAVE_FORK (re-execs without -d) - */ -#endif - } else { - syslog(LOG_INFO, "Running as child\n"); - } - mainloop(argc,argv); - _exit(0); -} - -static void mainloop(int argc, char **argv) -{ - socklen_t salen = sizeof(struct sockaddr_ll); - int i, s, rcg, j, no_discifs_cntr, ifs_change; - int logstr_cntr; - struct iflist *iflist = NULL; // Initialised after the 1st packet - struct sockaddr_ll sa; - struct packet *ipp_p; - char *udppdu; // FIXME: warning: pointer targets in assignment differ in signedness - fd_set sock_set; - struct timeval time_2_wait; - static struct ifsnr old_ifsnr[MAXIF+1]; // Old iflist to socket fd's mapping list - static struct ifsnr cur_ifsnr[MAXIF+1]; // Current iflist to socket fd's mapping list - unsigned char buf[1518]; - char *logstr = ""; - - no_discifs_cntr = MAX_NODISCOVER_IFS; - ifs_change = 0; - - /* - * Open general ethernet socket, only used to discover interfaces. - */ - if ((s = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL))) < 0) - syslog(LOG_INFO,"%s: Error creating socket", *argv); - - - /* - * Discover interfaces (initial set) and create a dedicated socket bound to the interface - */ - memset(old_ifsnr, -1, sizeof(old_ifsnr)); - memset(cur_ifsnr, -1, sizeof(cur_ifsnr)); - iflist = discoverActiveInterfaces(s); - for (i=0; iflist[i].index; ++i) { - if ((cur_ifsnr[i].sock_nr = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL))) < 0) { - syslog(LOG_ERR, "mainloop: Error, socket error! (rv=%d, errno=%d)", cur_ifsnr[i].sock_nr, errno); - exit(1); - } - bind_to_iface(cur_ifsnr[i].sock_nr, iflist[i].index); - cur_ifsnr[i].ifindex = iflist[i].index; - } - NVBCR_PRINTF(("Displaying INITIAL active interfaces..\n")); - if (vnologging == 0) { - logstr = log_interfaces; - logstr_cntr = sprintf(logstr, "Initial active interfaces: "); - logstr += logstr_cntr; - } - for (i = 0; iflist[i].index; i++) - { - NVBCR_PRINTF(("\t\tactive interface number: %d, if=(%s), sock_nr=%d\n", i, iflistToString(&(iflist[i])), cur_ifsnr[i].sock_nr)); - if (vnologging == 0) { - logstr_cntr = sprintf(logstr, "%s ", iflistLogIToString(&(iflist[i]), i, &(cur_ifsnr[i]))); - logstr += logstr_cntr; - } - } - if (vnologging == 0) syslog(LOG_INFO, "%s", log_interfaces); - - // Main loop - while (1) - { - - /* - * Check all (interface) sockets for incoming packets - */ - FD_ZERO(&sock_set); - for (i=0; iflist[i].index; ++i) - { - if (cur_ifsnr[i].sock_nr >= 0) { - FD_SET(cur_ifsnr[i].sock_nr, &sock_set); - } - } - - /* - * Don't wait more than MAX_SELECT_WAIT seconds - */ - time_2_wait.tv_sec = MAX_SELECT_WAIT; - time_2_wait.tv_usec = 0L; - - /* select on sockets */ - rcg = select(MAXIF, &sock_set, (fd_set *) NULL,(fd_set *) NULL, &time_2_wait); - - if (rcg < 0) - { - syslog(LOG_ERR, "Error, select error! (rv=%d, errno=%d)", rcg, errno); - exit(1); - } - - if (rcg == 0) - { - /* TimeOut, rediscover interfaces */ - NVBCR_PRINTF(("Select timeout, rediscover interfaces\n")); - copy_ifsnr(cur_ifsnr, old_ifsnr); - memset(cur_ifsnr, -1, sizeof(cur_ifsnr)); - iflist = discoverActiveInterfaces(s); - /* - * Build new cur_ifsnr list. - * Make iflist[i] correspond with cur_ifsnr[i], so iflist[i].index == cur_ifsnr[i].ifindex - * The old list (old_ifsnr) is used to compare. - */ - for (i=0; iflist[i].index; ++i) { - /* check to see if it is a NEW interface */ - int fsnr = find_sock_nr(old_ifsnr, iflist[i].index); - if (fsnr == -1) { - /* found new interface, open dedicated socket and bind it to the interface */ - if ((cur_ifsnr[i].sock_nr = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL))) < 0) { - syslog(LOG_ERR, "mainloop: Error, socket error! (rv=%d, errno=%d)", cur_ifsnr[i].sock_nr, errno); - exit(1); - } - bind_to_iface(cur_ifsnr[i].sock_nr, iflist[i].index); - ifs_change = 1; - } - else - { - /* - * not a new interface, socket already openen, interface already - * bound. Update cur_ifsnr. - */ - cur_ifsnr[i].sock_nr = fsnr; - } - cur_ifsnr[i].ifindex = iflist[i].index; - } - /* Close disappeared interfaces */ - for (i=0; i<MAXIF; ++i) - { - if ((old_ifsnr[i].sock_nr != -1) && (old_ifsnr[i].ifindex != -1) && - (find_sock_nr(cur_ifsnr, old_ifsnr[i].ifindex) == -1)) { - NVBCR_PRINTF(("Closing an interface (it disappeared), namely: (s_nr=%d, ifidx=%d)\n", old_ifsnr[i].sock_nr, old_ifsnr[i].ifindex)); - close(old_ifsnr[i].sock_nr); - old_ifsnr[i].sock_nr = -1; - old_ifsnr[i].ifindex = -1; - ifs_change = 1; - } - } - if (ifs_change == 1) - { - NVBCR_PRINTF(("Active interface set changed --> displaying current active interfaces..\n")); - if (vnologging == 0) { - logstr = log_interfaces; - logstr_cntr = sprintf(logstr, "Active interface set changed to: "); - logstr += logstr_cntr; - } - for (i = 0; iflist[i].index; i++) - { - NVBCR_PRINTF(("\t\tactive interface number: %d, if=(%s), sock_nr=%d\n", i, iflistToString(&(iflist[i])), cur_ifsnr[i].sock_nr)); - if (vnologging == 0) { - logstr_cntr = sprintf(logstr, "%s ", iflistLogIToString(&(iflist[i]), i, &(cur_ifsnr[i]))); - logstr += logstr_cntr; - } - } - if (vnologging == 0) syslog(LOG_INFO, "%s", log_interfaces); - ifs_change = 0; - } - continue; - } - - if (rcg > 0) - { - /* rcg interfaces have pending input */ - for (i=0; ((iflist[i].index != 0) && (rcg > 0)); ++i) - { - if ((cur_ifsnr[i].sock_nr != -1) && (FD_ISSET(cur_ifsnr[i].sock_nr,&sock_set))) - { - /* Valid socket number and pending input, let's read */ - int rlen = read(cur_ifsnr[i].sock_nr, buf, sizeof(buf)); - ipp_p = (struct packet *)&(buf[0]); - NVBCR_PRINTF(("IP_Packet=(tot_len=%d, id=%02x%02x, ttl=%d, prot=%s, src_ip=%d.%d.%d.%d, dst_ip=%d.%d.%d.%d) (on if: %d/%d) ", ntohs(ipp_p->ip.tot_len), (ntohs(ipp_p->ip.id))>>8, (ntohs(ipp_p->ip.id))&0x00ff, ipp_p->ip.ttl, IpProtToString(ipp_p->ip.protocol), (ntohl(ipp_p->ip.saddr))>>24, ((ntohl(ipp_p->ip.saddr))&0x00ff0000)>>16, ((ntohl(ipp_p->ip.saddr))&0x0000ff00)>>8, (ntohl(ipp_p->ip.saddr))&0x000000ff, (ntohl(ipp_p->ip.daddr))>>24, ((ntohl(ipp_p->ip.daddr))&0x00ff0000)>>16, ((ntohl(ipp_p->ip.daddr))&0x0000ff00)>>8, (ntohl(ipp_p->ip.daddr))&0x000000ff, i, iflist[i].index)); - rcg -= 1; - - if ( (ipp_p->ip.protocol == IPPROTO_UDP) && - (((ntohl(ipp_p->ip.daddr)) & 0x000000ff) == 0x000000ff) && - (ipp_p->ip.ttl != 1) && - (!((*IP_UDPPDU_CHECKSUM_MSB_PTR((unsigned char *)ipp_p+(4*ipp_p->ip.ihl)) == 0) && - (*IP_UDPPDU_CHECKSUM_LSB_PTR((unsigned char *)ipp_p+(4*ipp_p->ip.ihl)) == 0))) ) - { - int nrsent; - int ifindex_to_exclude = iflist[i].index; - - NVBCR_PRINTF(("is an UDP BROADCAST (dstPort=%d, srcPort=%d) (with TTL!=1 and UDP_CHKSUM!=0)\n\n", - ntohs(ipp_p->udp.dest), ntohs(ipp_p->udp.source))); - if (vnologging == 0) { - logstr = log_relayed; - logstr_cntr = sprintf(logstr, "UDP_BroadCast(sp=%d,dp=%d) from: %s relayed to: ", ntohs(ipp_p->udp.source), - ntohs(ipp_p->udp.dest), iflistLogRToString(&(iflist[i]), i, &(cur_ifsnr[i]))); - logstr += logstr_cntr; - } - - /* going to relay a broadcast packet on all the other interfaces */ - for (j=0; iflist[j].index; ++j) - { - int prepare_ipp = 0; // Changing the incoming UDP broadcast needs to be done once - - if (iflist[j].index != ifindex_to_exclude) - { - NVBCR_PRINTF(("Going to sent UDP Broadcast on interface: %s, sock_nr=%d\n", iflistToString(&(iflist[j])), cur_ifsnr[j].sock_nr)); - - memset(&sa, 0, salen); - - sa.sll_family = AF_PACKET; - sa.sll_ifindex = iflist[j].index; /* Must be the SIOCGIFINDEX number */ - // Set the outgoing hardware address to 1's. True Broadcast - sa.sll_addr[0] = sa.sll_addr[1] = sa.sll_addr[2] = sa.sll_addr[3] = 0xff; - sa.sll_addr[4] = sa.sll_addr[5] = sa.sll_addr[6] = sa.sll_addr[7] = 0xff; - sa.sll_halen = 6; - - /* - * htons(ETH_P_IP) is necessary otherwise sendto will - * succeed but no packet is actually sent on the wire (this - * was the case for PPP interfaces, for ETH interfaces an unknown - * LAN frame is sent if htons(ETH_P_IP) is not set as protocol). - */ - sa.sll_protocol = htons(ETH_P_IP); /* ETH_P_PPP_MP */ - - if (prepare_ipp == 0) { - // change TimeToLive to 1, This is to avoid loops, bcrelay will *NOT* relay - // anything with TTL==1. - ipp_p->ip.ttl = 1; - - // The CRC gets broken here when sending over ipsec tunnels but that - // should not matter as we reassemble the packet at the other end. - ipp_p->ip.daddr = iflist[j].bcast; - - // check IP srcAddr (on some winXP boxes it is found to be - // different from the configured ppp address). - // Only do this for PPP interfaces. - if ((iflist[i].flags1 & IFLIST_FLAGS1_IF_IS_PPP) && - (ntohl(ipp_p->ip.saddr) != iflist[i].ifdstaddr)) - { - ipp_p->ip.saddr = htonl(iflist[i].ifdstaddr); - iflist[i].flags1 |= IFLIST_FLAGS1_CHANGED_INNER_SADDR; - } - - // Update IP checkSum (TTL and src/dest IP Address might have changed) - ip_update_checksum((unsigned char *)ipp_p); - /* Disable upper layer checksum */ - udppdu = (unsigned char *)ipp_p + (4 * ipp_p->ip.ihl); - *IP_UDPPDU_CHECKSUM_MSB_PTR(udppdu) = (unsigned char)0; - *IP_UDPPDU_CHECKSUM_LSB_PTR(udppdu) = (unsigned char)0; - - prepare_ipp = 1; - } - - /* - * The beauty of sending IP packets on a PACKET socket of type SOCK_DGRAM is that - * there is no need to concern about the physical/link layer header because it is - * filled in automatically (based on the contents of sa). - */ - if ((nrsent = sendto(cur_ifsnr[j].sock_nr, ipp_p, rlen, MSG_DONTWAIT|MSG_TRYHARD, (struct sockaddr *)&sa, salen)) < 0) - { - if (errno == ENETDOWN) { - syslog(LOG_NOTICE, "ignored ENETDOWN from sendto(), a network interface was going down?"); - } else if (errno == ENXIO) { - syslog(LOG_NOTICE, "ignored ENXIO from sendto(), a network interface went down?"); - } else if (errno == ENOBUFS) { - syslog(LOG_NOTICE, "ignored ENOBUFS from sendto(), temporary shortage of buffer memory"); - } else { - syslog(LOG_ERR, "mainloop: Error, sendto failed! (rv=%d, errno=%d)", nrsent, errno); - exit(1); - } - } - NVBCR_PRINTF(("Successfully relayed %d bytes \n", nrsent)); - if (vnologging == 0) { - logstr_cntr = sprintf(logstr, "%s ", iflistLogRToString(&(iflist[j]), j, &(cur_ifsnr[j]))); - logstr += logstr_cntr; - } - } - } - if (vnologging == 0) syslog(LOG_INFO, "%s", log_relayed); - } else { - NVBCR_PRINTF(("is NOT an UDP BROADCAST (with TTL!=1 and UDP_CHKSUM!=0)\n\n")); - } - } - } - /* - * Don't forget to discover new interfaces if we keep getting - * incoming packets (on an already discovered interface). - */ - if (no_discifs_cntr == 0) - { - no_discifs_cntr = MAX_NODISCOVER_IFS; - - /* no_discifs_cntr became 0, rediscover interfaces */ - NVBCR_PRINTF(("no_discifs_cntr became 0, rediscover interfaces\n")); - copy_ifsnr(cur_ifsnr, old_ifsnr); - memset(cur_ifsnr, -1, sizeof(cur_ifsnr)); - iflist = discoverActiveInterfaces(s); - /* - * Build new cur_ifsnr list. - * Make iflist[i] correspond with cur_ifsnr[i], so iflist[i].index == cur_ifsnr[i].ifindex - * The old list (old_ifsnr) is used to compare. - */ - for (i=0; iflist[i].index; ++i) { - /* check to see if it is a NEW interface */ - int fsnr = find_sock_nr(old_ifsnr, iflist[i].index); - if (fsnr == -1) { - /* found new interface, open dedicated socket and bind it to the interface */ - if ((cur_ifsnr[i].sock_nr = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL))) < 0) { - syslog(LOG_ERR, "mainloop: Error, socket error! (rv=%d, errno=%d)", cur_ifsnr[i].sock_nr, errno); - exit(1); - } - bind_to_iface(cur_ifsnr[i].sock_nr, iflist[i].index); - ifs_change = 1; - } - else - { - /* - * not a new interface, socket already openen, interface already - * bound. Update cur_ifsnr. - */ - cur_ifsnr[i].sock_nr = fsnr; - } - cur_ifsnr[i].ifindex = iflist[i].index; - } - /* Close disappeared interfaces */ - for (i=0; i<MAXIF; ++i) - { - if ((old_ifsnr[i].sock_nr != -1) && (old_ifsnr[i].ifindex != -1) && - (find_sock_nr(cur_ifsnr, old_ifsnr[i].ifindex) == -1)) { - NVBCR_PRINTF(("Closing an interface (it disappeared), namely: (s_nr=%d, ifidx=%d)\n", old_ifsnr[i].sock_nr, old_ifsnr[i].ifindex)); - close(old_ifsnr[i].sock_nr); - old_ifsnr[i].sock_nr = -1; - old_ifsnr[i].ifindex = -1; - ifs_change = 1; - } - } - if (ifs_change == 1) - { - NVBCR_PRINTF(("Active interface set changed --> displaying current active interfaces..\n")); - if (vnologging == 0) { - logstr = log_interfaces; - logstr_cntr = sprintf(logstr, "Active interface set changed to: "); - logstr += logstr_cntr; - } - for (i = 0; iflist[i].index; i++) - { - NVBCR_PRINTF(("\t\tactive interface number: %d, if=(%s), sock_nr=%d\n", i, iflistToString(&(iflist[i])), cur_ifsnr[i].sock_nr)); - if (vnologging == 0) { - logstr_cntr = sprintf(logstr, "%s ", iflistLogIToString(&(iflist[i]), i, &(cur_ifsnr[i]))); - logstr += logstr_cntr; - } - } - if (vnologging == 0) syslog(LOG_INFO, "%s", log_interfaces); - ifs_change = 0; - } - } - else - { - no_discifs_cntr -= MAX_SELECT_WAIT; - } - } - } -} - -// Discover active interfaces -struct iflist * -discoverActiveInterfaces(int s) { - static struct iflist iflist[MAXIF+1]; // Allow for MAXIF interfaces - static struct ifconf ifs; - int i, j, cntr = 0; - regex_t preg; - struct ifreq ifrflags, ifr; - struct sockaddr_in *sin; - - /* Reset iflist */ - memset(iflist, 0, sizeof(iflist)); - /* Reset ifs */ - memset(&ifs, 0, sizeof(ifs)); - - //regcomp(&preg, argv[1], REG_ICASE|REG_EXTENDED); - regcomp(&preg, interfaces, REG_ICASE|REG_EXTENDED); - ifs.ifc_len = MAXIF*sizeof(struct ifreq); - ifs.ifc_req = malloc(ifs.ifc_len); - ioctl(s, SIOCGIFCONF, &ifs); // Discover active interfaces - for (i = 0; i * sizeof(struct ifreq) < ifs.ifc_len && cntr < MAXIF; i++) - { - if (regexec(&preg, ifs.ifc_req[i].ifr_name, 0, NULL, 0) == 0) { - - /* - * Get interface flags and check status and type. - * Only if interface is up it will be used. - */ - memset(&ifrflags, 0, sizeof(ifrflags)); - strncpy(ifrflags.ifr_name, ifs.ifc_req[i].ifr_name, strlen(ifs.ifc_req[i].ifr_name)); - if (ioctl(s, SIOCGIFFLAGS, &ifrflags) < 0) { - syslog(LOG_ERR, "discoverActiveInterfaces: Error, SIOCGIFFLAGS Failed! (errno=%d)", errno); - exit(1); - } - - if (ifrflags.ifr_flags & IFF_UP) - { - /* - * Get interface index - */ - ioctl(s, SIOCGIFINDEX, &ifs.ifc_req[i]); -//Fix 3mar2003 - //iflist[cntr].index = (char)ifs.ifc_req[i].ifr_ifindex; - iflist[cntr].index = ifs.ifc_req[i].ifr_ifindex; - - /* - * Get interface name - */ - for (j=0; (j<sizeof(iflist[cntr].ifname) && j<strlen(ifs.ifc_req[i].ifr_ifrn.ifrn_name)); ++j) - iflist[cntr].ifname[j] = ifs.ifc_req[i].ifr_ifrn.ifrn_name[j]; - iflist[cntr].ifname[j+1] = '\0'; - - /* - * Get local IP address - */ - memset(&ifr, 0, sizeof(ifr)); - ifr.ifr_addr.sa_family = AF_INET; - (void)strncpy(ifr.ifr_name, iflist[cntr].ifname, strlen(iflist[cntr].ifname)+1); - if (ioctl(s, SIOCGIFADDR, (char *)&ifr) < 0) { - syslog(LOG_ERR, "discoverActiveInterfaces: Error, SIOCGIFADDR Failed! (errno=%d)", errno); - exit(1); - } - sin = (struct sockaddr_in *)&ifr.ifr_addr; - iflist[cntr].ifaddr = ntohl(sin->sin_addr.s_addr); - - iflist[cntr].flags1 = 0; - - if (ifrflags.ifr_flags & IFF_POINTOPOINT) { - /* - * Get remote IP address (only for PPP interfaces) - */ - memset(&ifr, 0, sizeof(ifr)); - ifr.ifr_addr.sa_family = AF_INET; - (void)strncpy(ifr.ifr_name, iflist[cntr].ifname, strlen(iflist[cntr].ifname)+1); - if (ioctl(s, SIOCGIFDSTADDR, (char *)&ifr) < 0) { - syslog(LOG_ERR, "discoverActiveInterfaces: Error, SIOCGIFDSTADDR Failed! (errno=%d)", errno); - exit(1); - } - sin = (struct sockaddr_in *)&ifr.ifr_addr; - iflist[cntr].ifdstaddr = ntohl(sin->sin_addr.s_addr); - - iflist[cntr].flags1 |= IFLIST_FLAGS1_IF_IS_PPP; - iflist[cntr].bcast = INADDR_BROADCAST; - } - else if (ifrflags.ifr_flags & IFF_BROADCAST) - { - iflist[cntr].ifdstaddr = 0; - iflist[cntr].flags1 |= IFLIST_FLAGS1_IF_IS_ETH; - iflist[cntr].bcast = INADDR_BROADCAST; - } - else - { - iflist[cntr].ifdstaddr = 0; - iflist[cntr].flags1 |= IFLIST_FLAGS1_IF_IS_UNKNOWN; - iflist[cntr].bcast = INADDR_BROADCAST; - } - - cntr++; - } - // IPSEC tunnels are a fun one. We must change the destination address - // so that it will be routed to the correct tunnel end point. - // We can define several tunnel end points for the same ipsec interface. - } else if (ipsec != "" && strncmp(ifs.ifc_req[i].ifr_name, "ipsec", 5) == 0) { - if (strncmp(ifs.ifc_req[i].ifr_name, ipsec, 6) == 0) { - struct hostent *hp = gethostbyname(ipsec+7); - ioctl(s, SIOCGIFINDEX, &ifs.ifc_req[i]); - iflist[cntr].index = ifs.ifc_req[i].ifr_ifindex; /* Store the SIOCGIFINDEX number */ - memcpy(&(iflist[cntr++].bcast), hp->h_addr, sizeof(u_int32_t)); - } - } - } - - iflist[cntr].index = 0; // Terminate list - free(ifs.ifc_req); // Stop that leak. - regfree(&preg); - - return iflist; -} - - - -unsigned int ip_compute_checksum(unsigned char *ippdu, int hlen) -{ - unsigned int sum = 0, temp; - unsigned char *p; - unsigned char cs_msb; - unsigned char cs_lsb; - - /* Save original checksum */ - cs_msb = *IP_IPPDU_CHECKSUM_MSB_PTR(ippdu); - cs_lsb = *IP_IPPDU_CHECKSUM_LSB_PTR(ippdu); - - *IP_IPPDU_CHECKSUM_MSB_PTR(ippdu) = 0; - *IP_IPPDU_CHECKSUM_LSB_PTR(ippdu) = 0; - - p = ippdu; - hlen /= 2; /* We'll compute taking two bytes a a time */ - while(hlen--) { sum += ((*p * 256) + *(p + 1)); p += 2; } - while ((temp = (sum >> 16))) { sum = (temp + (sum & 0xFFFF)); } - - /* Restore original checksum */ - *IP_IPPDU_CHECKSUM_MSB_PTR(ippdu) = cs_msb; - *IP_IPPDU_CHECKSUM_LSB_PTR(ippdu) = cs_lsb; - - return(~sum & 0xFFFF); -} - -void ip_update_checksum(unsigned char *ippdu) -{ - unsigned int cs; - - cs = ip_compute_checksum(ippdu, 4 * IP_IPPDU_IHL(ippdu)); - - *IP_IPPDU_CHECKSUM_MSB_PTR(ippdu) = (unsigned char)((cs >> 8) & 0xFF); - *IP_IPPDU_CHECKSUM_LSB_PTR(ippdu) = (unsigned char)(cs & 0xFF); -} - - -static char *IpProtToString( unsigned char prot ) -{ - switch( prot ) - { - case 0x11: - return "UDP"; - case 0x6: - return "TCP"; - case 0x2f: - return "GRE"; - case 0x1: - return "ICMP"; - default: - return "???"; - } -} - -static char *iflistToString( struct iflist *ifp ) -{ - static char str_tr[80+1]; - - sprintf(str_tr, "index=%d, ifname=%s, ifaddr=%ld.%ld.%ld.%ld, ifdstaddr=%ld.%ld.%ld.%ld, flags1=0x%04lx", - ifp->index, ifp->ifname, - (ifp->ifaddr)>>24, ((ifp->ifaddr)&0x00ff0000)>>16, ((ifp->ifaddr)&0x0000ff00)>>8, (ifp->ifaddr)&0x000000ff, - (ifp->ifdstaddr)>>24, ((ifp->ifdstaddr)&0x00ff0000)>>16, ((ifp->ifdstaddr)&0x0000ff00)>>8, - (ifp->ifdstaddr)&0x000000ff, ifp->flags1); - - return str_tr; -} - -static char *iflistLogRToString( struct iflist *ifp, int idx, struct ifsnr *ifnr ) -{ - static char str_tr[MAX_IFLOGTOSTR]; /* - * This makes function: 1) non-reentrant (doesn't matter). - * 2) not useable multiple times by (s)printf. - */ - sprintf(str_tr, "%s", ifp->ifname); - return str_tr; -} - -static char *iflistLogIToString( struct iflist *ifp, int idx, struct ifsnr *ifnr ) -{ - static char str_tr[MAX_IFLOGTOSTR]; /* - * This makes function: 1) non-reentrant (doesn't matter). - * 2) not useable multiple times by (s)printf. - */ - sprintf(str_tr, "%s(%d/%d/%d)", ifp->ifname, idx, ifp->index, ifnr->sock_nr); - return str_tr; -} - -static void bind_to_iface(int fd, int ifindex) -{ - struct sockaddr_ll sll; - - memset(&sll, 0, sizeof(sll)); - sll.sll_family = AF_PACKET; - sll.sll_ifindex = ifindex; - sll.sll_protocol = htons(ETH_P_ALL); - - if (bind(fd, (struct sockaddr *) &sll, sizeof(sll)) == -1) { - syslog(LOG_ERR, "bind_to_iface: Error, bind failed! (rv=-1, errno=%d)", errno); - exit(1); - } -} - -static void copy_ifsnr(struct ifsnr *from, struct ifsnr *to) -{ - int i; - - for (i=0; i<MAXIF; ++i) - { - to[i].sock_nr = from[i].sock_nr; - to[i].ifindex = from[i].ifindex; - } -} - -static int find_sock_nr(struct ifsnr *l, int ifidx) -{ - int i; - - for (i=0; i<MAXIF; ++i) - if (l[i].ifindex == ifidx) return l[i].sock_nr; - /* not found */ - return -1; -} - |