The following commit has been merged in the next branch: commit a8926828bcf3afd9b3f88d7b547bc0b152c8a8d3 Author: Marek Lindner lindner_marek@yahoo.de Date: Tue Feb 1 22:09:31 2011 +0100
batctl: add raw wifi packet decapsulation support
Signed-off-by: Marek Lindner lindner_marek@yahoo.de Signed-off-by: Sven Eckelmann sven@narfation.org
diff --git a/tcpdump.c b/tcpdump.c index dad4049..4443a2a 100644 --- a/tcpdump.c +++ b/tcpdump.c @@ -29,6 +29,7 @@ #include <sys/time.h> #include <arpa/inet.h> #include <net/if.h> +#include <net/if_arp.h> #include <netinet/in.h> #include <netinet/ip.h> #include <netinet/tcp.h> @@ -459,6 +460,75 @@ static void parse_eth_hdr(unsigned char *packet_buff, ssize_t buff_len, int read } }
+static void parse_wifi_hdr(unsigned char *packet_buff, ssize_t buff_len, int read_opt, int time_printed) +{ + struct ether_header *eth_hdr; + struct ieee80211_hdr *wifi_hdr; + unsigned char *shost, *dhost; + uint16_t fc; + int hdr_len; + + if (buff_len <= (ssize_t)PRISM_HEADER_LEN) + return; + + buff_len -= PRISM_HEADER_LEN; + packet_buff += PRISM_HEADER_LEN; + + /* we assume a minimum size of 38 bytes + * (802.11 data frame + LLC) + * before we calculate the real size */ + if (buff_len <= 38) + return; + + wifi_hdr = (struct ieee80211_hdr *)packet_buff; + fc = ntohs(wifi_hdr->frame_control); + + /* not carrying payload */ + if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) + return; + + /* encrypted packet */ + if (fc & IEEE80211_FCTL_PROTECTED) + return; + + shost = wifi_hdr->addr2; + if (fc & IEEE80211_FCTL_FROMDS) + shost = wifi_hdr->addr3; + else if (fc & IEEE80211_FCTL_TODS) + shost = wifi_hdr->addr4; + + dhost = wifi_hdr->addr1; + if (fc & IEEE80211_FCTL_TODS) + dhost = wifi_hdr->addr3; + + hdr_len = 24; + if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS)) + hdr_len = 30; + + if (fc & IEEE80211_STYPE_QOS_DATA) + hdr_len += 2; + + /* LLC */ + hdr_len += 8; + hdr_len -= sizeof(struct ether_header); + + if (buff_len <= hdr_len) + return; + + buff_len -= hdr_len; + packet_buff += hdr_len; + + eth_hdr = (struct ether_header *)packet_buff; + memmove(eth_hdr->ether_shost, shost, ETH_ALEN); + memmove(eth_hdr->ether_dhost, dhost, ETH_ALEN); + + /* printf("parse_wifi_hdr(): ether_type: 0x%04x\n", ntohs(eth_hdr->ether_type)); + printf("parse_wifi_hdr(): shost: %s\n", ether_ntoa_long((struct ether_addr *)eth_hdr->ether_shost)); + printf("parse_wifi_hdr(): dhost: %s\n", ether_ntoa_long((struct ether_addr *)eth_hdr->ether_dhost)); */ + + parse_eth_hdr(packet_buff, buff_len, read_opt, time_printed); +} + int tcpdump(int argc, char **argv) { struct ifreq req; @@ -527,6 +597,27 @@ int tcpdump(int argc, char **argv) memset(&req, 0, sizeof (struct ifreq)); strncpy(req.ifr_name, dump_if->dev, IFNAMSIZ);
+ res = ioctl(dump_if->raw_sock, SIOCGIFHWADDR, &req); + if (res < 0) { + printf("Error - can't create raw socket (SIOCGIFHWADDR): %s\n", strerror(errno)); + close(dump_if->raw_sock); + goto out; + } + + dump_if->hw_type = req.ifr_hwaddr.sa_family; + + switch (dump_if->hw_type) { + case ARPHRD_ETHER: + case ARPHRD_IEEE80211_PRISM: + break; + default: + printf("Error - interface '%s' is of unknown type: %i\n", dump_if->dev, dump_if->hw_type); + goto out; + } + + memset(&req, 0, sizeof (struct ifreq)); + strncpy(req.ifr_name, dump_if->dev, IFNAMSIZ); + res = ioctl(dump_if->raw_sock, SIOCGIFINDEX, &req);
if (res < 0) { @@ -589,7 +680,18 @@ int tcpdump(int argc, char **argv) continue; }
- parse_eth_hdr(packet_buff, read_len, read_opt, 0); + switch (dump_if->hw_type) { + case ARPHRD_ETHER: + parse_eth_hdr(packet_buff, read_len, read_opt, 0); + break; + case ARPHRD_IEEE80211_PRISM: + parse_wifi_hdr(packet_buff, read_len, read_opt, 0); + break; + default: + /* should not happen */ + break; + } + fflush(stdout); }
diff --git a/tcpdump.h b/tcpdump.h index b3ea186..17eaeb0 100644 --- a/tcpdump.h +++ b/tcpdump.h @@ -23,6 +23,10 @@ #include <netpacket/packet.h> #include "list-batman.h"
+#ifndef ARPHRD_IEEE80211_PRISM +#define ARPHRD_IEEE80211_PRISM 802 +#endif + #define DUMP_TYPE_BATOGM 1 #define DUMP_TYPE_BATICMP 2 #define DUMP_TYPE_BATUCAST 4 @@ -31,11 +35,21 @@ #define DUMP_TYPE_BATFRAG 32 #define DUMP_TYPE_NONBAT 64
+#define IEEE80211_FCTL_FTYPE 0x0c00 +#define IEEE80211_FCTL_TODS 0x0001 +#define IEEE80211_FCTL_FROMDS 0x0002 +#define IEEE80211_FCTL_PROTECTED 0x0040 + +#define IEEE80211_FTYPE_DATA 0x0800 + +#define IEEE80211_STYPE_QOS_DATA 0x8000 + struct dump_if { struct list_head list; char *dev; int32_t raw_sock; struct sockaddr_ll addr; + int32_t hw_type; };
struct vlanhdr { @@ -43,4 +57,39 @@ struct vlanhdr { u_int16_t ether_type; } __attribute__ ((packed));
+struct ieee80211_hdr { + u_int16_t frame_control; + u_int16_t duration_id; + u_int8_t addr1[6]; + u_int8_t addr2[6]; + u_int8_t addr3[6]; + u_int16_t seq_ctrl; + u_int8_t addr4[6]; +} __attribute__ ((packed)); + +struct prism_item { + u_int32_t did; + u_int16_t status; + u_int16_t len; + u_int32_t data; +}; + +struct prism_header { + u_int32_t msgcode; + u_int32_t msglen; + u_int8_t devname[16]; + struct prism_item hosttime; + struct prism_item mactime; + struct prism_item channel; + struct prism_item rssi; + struct prism_item sq; + struct prism_item signal; + struct prism_item noise; + struct prism_item rate; + struct prism_item istx; + struct prism_item frmlen; +}; + +#define PRISM_HEADER_LEN sizeof(struct prism_header) + int tcpdump(int argc, char **argv);