fixed and cached offsets - 1st try

diff --git a/hdw-sniff.c b/hdw-sniff.c
index 54e40db..94830b7 100644 (file)
--- a/hdw-sniff.c
+++ b/hdw-sniff.c
@@ -103,7 +103,7 @@ int main(int argc, char *argv[]) {
                FD_ZERO(&pcap_fd_set);
                FD_SET(pcap_fd,&pcap_fd_set);
                fd_set_tv.tv_sec=0;
-               fd_set_tv.tv_usec=500000;
+               fd_set_tv.tv_usec=200000;
 
                if((select(pcap_fd+1,&pcap_fd_set,NULL,NULL,&fd_set_tv)) && (FD_ISSET(pcap_fd,&pcap_fd_set))) pcap_dispatch(pcap_handle,-1,pcap_process,(u_char *)&my_info_struct);
                else if((hop_channel(&my_info_struct,foo_fd))==-1) { 
@@ -125,7 +125,13 @@ void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
        struct ethhdr *e_hdr;
        struct ip *ip_hdr;
        struct info_struct *my_info_struct;
-       int i;
+       int i,p_o,w_o,e_o,i_o;
+       
+       /* cache offsets */
+       p_o=sizeof(struct linux_wlan_ng_prism_hdr);
+       w_o=sizeof(struct ieee802_11_hdr);
+       e_o=sizeof(struct ethhdr);
+       i_o=sizeof(struct ip);
 
        my_info_struct=(struct info_struct *)info;
        ++(my_info_struct->count);
@@ -140,16 +146,17 @@ void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
        /* prism wlan ng headers */
        if((my_info_struct->mmode-0x30==1) && 
                (strncmp(my_info_struct->dev,"wlan",4)==0)) {
-       printf("prism header:\n");
+       printf("prism header: (%d bytes)\n",p_o);
        prism_hdr=(struct linux_wlan_ng_prism_hdr *)package;
        printf("message code/length: %d/%d\n",ntohs(prism_hdr->msgcode),
                                                ntohs(prism_hdr->msglen));
        printf("device: %s\n",prism_hdr->devname);
+       /* skip wlan_ng_prism header */
+       // package=package+p_o;
 
        /* ieee802.11 header */
-       printf("ieee802.11 header:\n");
-       package+=sizeof(struct linux_wlan_ng_prism_hdr);
-       w_hdr=(struct ieee802_11_hdr *)package;
+       printf("ieee802.11 header: (%d bytes)\n",w_o);
+       w_hdr=(struct ieee802_11_hdr *)(package+p_o);
        
        printf("debug:\n");
        for(i=0;i<16;i++) {
@@ -163,13 +170,13 @@ void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
                                                        "ok":"unknown");
        // printf("type: 
        /* skip ieee802.11 header */
-       package=package+sizeof(struct ieee802_11_hdr);
+       // package=package+w_o;
        }
 
        /* ieee802.3 */
        /* ethernet */
        printf("ethernet:\n");
-       e_hdr=(struct ethhdr *)package;
+       e_hdr=(struct ethhdr *)(package+p_o+w_o);
        /* what types ? */
        printf("type = ");
        printf("%x  ",ntohs(e_hdr->h_proto));
@@ -182,7 +189,7 @@ void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
                /* IP ? */
        if(ntohs(e_hdr->h_proto)==ETH_P_IP) {
                printf("ip protocol: ");
-               ip_hdr=(struct ip *)(package+sizeof(struct ethhdr));
+               ip_hdr=(struct ip *)(package+p_o+w_o+e_o);
                printf("version = %x ",ntohs(ip_hdr->ip_v));
                printf("header_length = %x \n",ntohs(ip_hdr->ip_hl));
                printf("service = %x ",ntohs(ip_hdr->ip_tos));
@@ -196,8 +203,8 @@ void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
                                                ntohs(ip_hdr->ip_p));
                printf("chksum: %x\n",ntohs(ip_hdr->ip_sum));
        }
-       printf("all_hex_dump:\n");
-       for(i=sizeof(struct ethhdr);i<pcap_header->caplen;i++)
+       printf("all ethernet dump:\n");
+       for(i=p_o+w_o+e_o;i<pcap_header->caplen;i++)
                printf("%x ",*(package+i));
        printf("\n");
 }