From 6df3dfdf18115f5a3ce8477749ecef77a66260c0 Mon Sep 17 00:00:00 2001 From: mjm Date: Wed, 27 Nov 2002 22:34:42 +0000 Subject: added cardmode and sniffer --- (limited to 'noncore/net/wellenreiter/libwellenreiter/source/sniff.cc') diff --git a/noncore/net/wellenreiter/libwellenreiter/source/sniff.cc b/noncore/net/wellenreiter/libwellenreiter/source/sniff.cc new file mode 100644 index 0000000..fedd8fc --- a/dev/null +++ b/noncore/net/wellenreiter/libwellenreiter/source/sniff.cc @@ -0,0 +1,303 @@ +/* + * rfmon mode sniffer + * + * $Id$ + */ + +#include "sniff.hh" +#include "ieee802_11.hh" +#include "extract.hh" +#include "log.hh" + +/* Main function, checks packets */ +void process_packets(const struct pcap_pkthdr *pkthdr, const unsigned char *packet) +{ + unsigned int caplen = pkthdr->caplen; + unsigned int length = pkthdr->len; + u_int16_t fc; + unsigned int HEADER_LENGTH; + + /* pinfo holds all interresting information for us */ + struct packetinfo pinfo; + struct packetinfo *pinfoptr; + pinfoptr=&pinfo; + + pinfoptr->isvalid = 0; + pinfoptr->pktlen = pkthdr->len; + + if (caplen < IEEE802_11_FC_LEN) + { + /* This is a garbage packet, because is does not long enough + to hold a 802.11b header */ + pinfoptr->isvalid = 0; + return; + } + + /* Gets the framecontrol bits (2bytes long) */ + fc = EXTRACT_LE_16BITS(packet); + + HEADER_LENGTH = GetHeaderLength(fc); + + if (caplen < HEADER_LENGTH) + { + /* This is a garbage packet, because it is not long enough + to hold a correct header of its type */ + pinfoptr->isvalid = 0; + return; + } + + /* Decode 802.11b header out of the packet */ + if (decode_80211b_hdr(packet,pinfoptr) == 0) + { + /* Justification of the ofset to further process the packet */ + length -= HEADER_LENGTH; + caplen -= HEADER_LENGTH; + packet += HEADER_LENGTH; + } + else /* Something is wrong,could not be a correct packet */ + return; + + switch (FC_TYPE(fc)) + { + /* Is it a managemnet frame? */ + case T_MGMT: + switch (FC_SUBTYPE(fc)) + { + case ST_BEACON: + if (handle_beacon(fc, packet,pinfoptr) ==0) + { + if (!strcmp(pinfoptr->desthwaddr,"ff:ff:ff:ff:ff:ff") == 0) + { + /* Every beacon must have the broadcast as destination + so it must be a shitti packet */ + pinfoptr->isvalid = 0; + return; + } + + if (pinfoptr->cap_ESS == pinfoptr->cap_IBSS) + { + /* Only one of both are possible, so must be + a noise packet, if this comes up */ + pinfoptr->isvalid = 0; + return; + } + if (pinfoptr->channel < 1 || pinfoptr->channel > 14) + { + /* Only channels between 1 and 14 are possible + others must be noise packets */ + pinfoptr->isvalid = 0; + return; + } + + + /* Here should be the infos to the gui issued */ + if (pinfoptr->cap_ESS == 1 &&pinfoptr->cap_IBSS ==0) + { + printf ("\nHave found an accesspoint:"); + } + else if(pinfoptr->cap_ESS == 0 && pinfoptr->cap_IBSS == 1) + { + printf ("\nHave found an AD-HOC station:"); + + } + if (strcmp (pinfoptr->ssid,NONBROADCASTING) ==0) + { + printf ("\n\tOn a non-broadcasting network"); + } + else + { + printf ("\n\tOn network : %s",pinfoptr->ssid); + } + printf ("\n\tLen SSID : %d",pinfoptr->ssid_len); + printf ("\n\tOn Channel : %d",pinfoptr->channel); + printf ("\n\tEncryption : %s", pinfoptr->cap_WEP ? "ON" : "OFF"); + printf ("\n\tMacaddress : %s",pinfoptr->sndhwaddr); + printf ("\n\tBssid : %s",pinfoptr->bssid); + printf ("\n\tDest : %s\n",pinfoptr->desthwaddr); + } + break; + default: + wl_logerr("Unknown IEEE802.11 frame subtype (%d)", FC_SUBTYPE(fc)); + break; + } /* End of switch over different mgt frame types */ + + break; + + case T_CTRL: + wl_loginfo("Received control frame, not implemented yet"); + break; + + case T_DATA: + wl_loginfo("Received date frame, not implemented yet"); + break; + + default: + wl_logerr("Unknown IEEE802.11 frame type (%d)", FC_TYPE(fc)); + break; + } +} + +/* This decodes the 802.11b frame header out of the 802.11b packet + all the infos is placed into the packetinfo structure */ +int decode_80211b_hdr(const u_char *p,struct packetinfo *ppinfo) +{ + const struct mgmt_header_t *mgthdr = (const struct mgmt_header_t *) p; + ppinfo->fcsubtype = FC_SUBTYPE(mgthdr->fc); + + /* Get the sender, bssid and dest mac address */ + etheraddr_string(mgthdr->bssid,ppinfo->bssid); + etheraddr_string(mgthdr->da,ppinfo->desthwaddr); + etheraddr_string(mgthdr->sa,ppinfo->sndhwaddr); + ppinfo->fc_wep = FC_WEP(mgthdr->fc); + return 0; +} + + +void etheraddr_string(register const u_char *ep, char *text) +{ + static char hex[] = "0123456789abcdef"; + register unsigned int i, j; + register char *cp; + char buf[sizeof("00:00:00:00:00:00")]; + cp = buf; + if ((j = *ep >> 4) != 0) + *cp++ = hex[j]; + *cp++ = hex[*ep++ & 0xf]; + for (i = 5; (int)--i >= 0;) { + *cp++ = ':'; + if ((j = *ep >> 4) != 0) + *cp++ = hex[j]; + *cp++ = hex[*ep++ & 0xf]; + } + *cp = '\0'; + strcpy(text,buf); +} + +/* beacon handler */ +int handle_beacon(u_int16_t fc, const u_char *p,struct packetinfo *ppinfo) +{ + struct mgmt_body_t pbody; + int offset = 0; + + /* Get the static informations out of the packet */ + memset(&pbody, 0, sizeof(pbody)); + memcpy(&pbody.timestamp, p, 8); + offset += 8; + pbody.beacon_interval = EXTRACT_LE_16BITS(p+offset); + offset += 2; + pbody.capability_info = EXTRACT_LE_16BITS(p+offset); + offset += 2; + + /* Gets the different flags out of the capabilities */ + ppinfo->cap_ESS = CAPABILITY_ESS(pbody.capability_info); + ppinfo->cap_IBSS = CAPABILITY_IBSS(pbody.capability_info); + ppinfo->cap_WEP = CAPABILITY_PRIVACY(pbody.capability_info); + + /* Gets the tagged elements out of the packets */ + while (offset + 1 < ppinfo->pktlen) + { + switch (*(p + offset)) + { + case E_SSID: + memcpy(&(pbody.ssid),p+offset,2); offset += 2; + if (pbody.ssid.length > 0) + { + memcpy(&(pbody.ssid.ssid),p+offset,pbody.ssid.length); offset += pbody.ssid.length; + pbody.ssid.ssid[pbody.ssid.length]='\0'; + if (strcmp((char *)pbody.ssid.ssid,"")==0) + ppinfo->ssid = NONBROADCASTING; + else + ppinfo->ssid = (char *)pbody.ssid.ssid; + ppinfo->ssid_len = pbody.ssid.length; + } + break; + + case E_CHALLENGE: + memcpy(&(pbody.challenge),p+offset,2); offset += 2; + if (pbody.challenge.length > 0) + { + memcpy(&(pbody.challenge.text),p+offset,pbody.challenge.length); offset += pbody.challenge.length; + pbody.challenge.text[pbody.challenge.length]='\0'; + } + break; + case E_RATES: + memcpy(&(pbody.rates),p+offset,2); offset += 2; + if (pbody.rates.length > 0) + { + memcpy(&(pbody.rates.rate),p+offset,pbody.rates.length); offset += pbody.rates.length; + } + break; + case E_DS: + memcpy(&(pbody.ds),p+offset,3); offset +=3; + ppinfo->channel = pbody.ds.channel; + break; + case E_CF: + memcpy(&(pbody.cf),p+offset,8); offset +=8; + break; + case E_TIM: + memcpy(&(pbody.tim),p+offset,2); offset +=2; + memcpy(&(pbody.tim.count),p+offset,3); offset +=3; + if ((pbody.tim.length -3) > 0) + { + memcpy((pbody.tim.bitmap),p+(pbody.tim.length -3),(pbody.tim.length -3)); + offset += pbody.tim.length -3; + } + break; + default: + + offset+= *(p+offset+1) + 2; + break; + } /* end of switch*/ + } /* end of for loop */ + return 0; + +} /* End of handle_beacon */ + + +int GetHeaderLength(u_int16_t fc) +{ + int iLength=0; + + switch (FC_TYPE(fc)) + { + case T_MGMT: + iLength = MGMT_HEADER_LEN; + break; + case T_CTRL: + switch (FC_SUBTYPE(fc)) + { + case CTRL_PS_POLL: + iLength = CTRL_PS_POLL_LEN; + break; + case CTRL_RTS: + iLength = CTRL_RTS_LEN; + break; + case CTRL_CTS: + iLength = CTRL_CTS_LEN; + break; + case CTRL_ACK: + iLength = CTRL_ACK_LEN; + break; + case CTRL_CF_END: + iLength = CTRL_END_LEN; + break; + case CTRL_END_ACK: + iLength = CTRL_END_ACK_LEN; + break; + default: + iLength = 0; + break; + } + break; + case T_DATA: + if (FC_TO_DS(fc) && FC_FROM_DS(fc)) + iLength = 30; + else + iLength = 24; + break; + default: + wl_logerr("unknown IEEE802.11 frame type (%d)", FC_TYPE(fc)); + break; + } + return iLength; +} -- cgit v0.9.0.2