66 files changed, 15542 insertions, 1 deletions
diff --git a/src/pppoe-sniff.c b/src/pppoe-sniff.c new file mode 100755 index 0000000..1569857 --- a/dev/null +++ b/src/pppoe-sniff.c @@ -0,0 +1,266 @@ +/*********************************************************************** +* +* pppoe-sniff.c +* +* Sniff a network for likely-looking PPPoE frames and deduce the value +* to supply to PPPOE_EXTRA in /etc/ppp/pppoe.conf. USE AT YOUR OWN RISK. +* +* Copyright (C) 2000 by Roaring Penguin Software Inc. +* +* This program may be distributed according to the terms of the GNU +* General Public License, version 2 or (at your option) any later version. +* +* LIC: GPL +* +***********************************************************************/ + +static char const RCSID[] = +"$Id$"; + +#include "pppoe.h" + +#ifdef HAVE_GETOPT_H +#include <getopt.h> +#endif + +#include <errno.h> +#include <unistd.h> +#include <string.h> +#include <stdlib.h> + +#ifdef USE_DLPI +#include <sys/dlpi.h> +/* function declarations */ +void dlpromisconreq( int fd, u_long level); +void dlokack(int fd, char *bufp); +#endif + +/* Default interface if no -I option given */ +#define DEFAULT_IF "eth0" + +/* Global vars */ +int SeenPADR = 0; +int SeenSess = 0; +UINT16_t SessType, DiscType; + +char *IfName = NULL; /* Interface name */ +char *ServiceName = NULL; /* Service name */ + +/********************************************************************** +*%FUNCTION: parsePADRTags +*%ARGUMENTS: +* type -- tag type +* len -- tag length +* data -- tag data +* extra -- extra user data. +*%RETURNS: +* Nothing +*%DESCRIPTION: +* Picks interesting tags out of a PADR packet +***********************************************************************/ +void +parsePADRTags(UINT16_t type, UINT16_t len, unsigned char *data, + void *extra) +{ + switch(type) { + case TAG_SERVICE_NAME: + ServiceName = malloc(len+1); + if (ServiceName) { + memcpy(ServiceName, data, len); + ServiceName[len] = 0; + } + break; + } +} + +/********************************************************************** +*%FUNCTION: fatalSys +*%ARGUMENTS: +* str -- error message +*%RETURNS: +* Nothing +*%DESCRIPTION: +* Prints a message plus the errno value to stderr and exits. +***********************************************************************/ +void +fatalSys(char const *str) +{ + char buf[1024]; + sprintf(buf, "%.256s: %.256s", str, strerror(errno)); + printErr(buf); + exit(1); +} + +/********************************************************************** +*%FUNCTION: rp_fatal +*%ARGUMENTS: +* str -- error message +*%RETURNS: +* Nothing +*%DESCRIPTION: +* Prints a message to stderr and syslog and exits. +***********************************************************************/ +void +rp_fatal(char const *str) +{ + printErr(str); + exit(1); +} + +/********************************************************************** +*%FUNCTION: usage +*%ARGUMENTS: +* argv0 -- program name +*%RETURNS: +* Nothing +*%DESCRIPTION: +* Prints usage information and exits. +***********************************************************************/ +void +usage(char const *argv0) +{ + fprintf(stderr, "Usage: %s [options]\n", argv0); + fprintf(stderr, "Options:\n"); + fprintf(stderr, " -I if_name -- Specify interface (default %s.)\n", + DEFAULT_IF); + fprintf(stderr, " -V -- Print version and exit.\n"); + fprintf(stderr, "\nPPPoE Version %s, Copyright (C) 2000 Roaring Penguin Software Inc.\n", VERSION); + fprintf(stderr, "PPPoE comes with ABSOLUTELY NO WARRANTY.\n"); + fprintf(stderr, "This is free software, and you are welcome to redistribute it under the terms\n"); + fprintf(stderr, "of the GNU General Public License, version 2 or any later version.\n"); + fprintf(stderr, "http://www.roaringpenguin.com\n"); + exit(0); +} + +#if !defined(USE_LINUX_PACKET) && !defined(USE_DLPI) + +int +main() +{ + fprintf(stderr, "Sorry, pppoe-sniff works only on Linux.\n"); + return 1; +} + +#else + +/********************************************************************** +*%FUNCTION: main +*%ARGUMENTS: +* argc, argv -- count and values of command-line arguments +*%RETURNS: +* Nothing +*%DESCRIPTION: +* Main program +***********************************************************************/ +int +main(int argc, char *argv[]) +{ + int opt; + int sock; + PPPoEPacket pkt; + int size; +#ifdef USE_DLPI + long buf[MAXDLBUF]; +#endif + + if (getuid() != geteuid() || + getgid() != getegid()) { + fprintf(stderr, "SECURITY WARNING: pppoe-sniff will NOT run suid or sgid. Fix your installation.\n"); + exit(1); + } + + while((opt = getopt(argc, argv, "I:V")) != -1) { + switch(opt) { + case 'I': + SET_STRING(IfName, optarg); + break; + case 'V': + printf("pppoe-sniff: Roaring Penguin PPPoE Version %s\n", VERSION); + exit(0); + default: + usage(argv[0]); + } + } + + /* Pick a default interface name */ + if (!IfName) { + IfName = DEFAULT_IF; + } + + /* Open the interface */ +#ifdef USE_DLPI + sock = openInterface(IfName, Eth_PPPOE_Discovery, NULL); + dlpromisconreq(sock, DL_PROMISC_PHYS); + dlokack(sock, (char *)buf); + dlpromisconreq(sock, DL_PROMISC_SAP); + dlokack(sock, (char *)buf); +#else + + sock = openInterface(IfName, ETH_P_ALL, NULL); + +#endif + + /* We assume interface is in promiscuous mode -- use ifconfig to + ensure this */ + fprintf(stderr, "Sniffing for PADR. Start your connection on another machine...\n"); + while (!SeenPADR) { + if (receivePacket(sock, &pkt, &size) < 0) continue; + if (ntohs(pkt.length) + HDR_SIZE > (unsigned int)size) continue; + if (pkt.ver != 1 || pkt.type != 1) continue; + if (pkt.code != CODE_PADR) continue; + + /* Looks promising... parse it */ + if (parsePacket(&pkt, parsePADRTags, NULL) < 0) { + continue; + } + DiscType = ntohs(pkt.ethHdr.h_proto); + fprintf(stderr, "\nExcellent! Sniffed a likely-looking PADR.\n"); + break; + } + + while (!SeenSess) { + if (receivePacket(sock, &pkt, &size) < 0) continue; + if (ntohs(pkt.length) + HDR_SIZE > (unsigned int)size) continue; + if (pkt.ver != 1 || pkt.type != 1) continue; + if (pkt.code != CODE_SESS) continue; + + /* Cool! */ + SessType = ntohs(pkt.ethHdr.h_proto); + break; + } + + fprintf(stderr, "Wonderful! Sniffed a likely-looking session packet.\n"); + if ((ServiceName == NULL || *ServiceName == 0) && + DiscType == ETH_PPPOE_DISCOVERY && + SessType == ETH_PPPOE_SESSION) { + fprintf(stderr, "\nGreat! It looks like a standard PPPoE service.\nYou should not need anything special in the configuration file.\n"); + return 0; + } + + fprintf(stderr, "\nOK, looks like you need something special in the configuration file.\nTry this:\n\n"); + if (ServiceName != NULL && *ServiceName != 0) { + fprintf(stderr, "SERVICENAME='%s'\n", ServiceName); + } + if (DiscType != ETH_PPPOE_DISCOVERY || SessType != ETH_PPPOE_SESSION) { + fprintf(stderr, " PPPOE_EXTRA='-f %x:%x'\n", DiscType, SessType); + } + return 0; +} + +#endif +/********************************************************************** +*%FUNCTION: sysErr +*%ARGUMENTS: +* str -- error message +*%RETURNS: +* Nothing +*%DESCRIPTION: +* Prints a message plus the errno value to syslog. +***********************************************************************/ +void +sysErr(char const *str) +{ + char buf[1024]; + sprintf(buf, "%.256s: %.256s", str, strerror(errno)); + printErr(buf); +} |