How to print packet info of a specific IP address in netfilter using C?












0















I'm using this code to print some packet info about "all" received and sent packets from all IP addresses. How do I only print packet info of a specific IP address?



this is part of the code:



{
struct ethhdr *eth;
struct iphdr *ip_header;

eth = (struct ethhdr*)skb_mac_header(skb);
ip_header = (struct iphdr *)skb_network_header(skb);

if (HOST_IP_ADDR == ip_header->saddr)
return NF_ACCEPT;

printk("NF_IP_LOCAL_IN hook:n");
printk("src mac %pM, dst mac %pMn", eth->h_source, eth->h_dest);
printk("src IP addr:=%pI4n", &ip_header->saddr);
return NF_ACCEPT;
}









share|improve this question


















  • 1





    Something along the line of if (the ip address == the ip address you want) {print the stuff}?

    – immibis
    Nov 20 '18 at 4:47











  • I tried this option and also I used strcmp, both of them gives errors.

    – Xi N
    Nov 20 '18 at 12:39











  • if (HOST_IP_ADDR == ip_header->saddr) looks like an IP address comparison to me. So you know how to compare IP addresses.

    – immibis
    Nov 20 '18 at 20:44











  • I would like to capture packet info for specific address, my VM has around 10 IP. I assign those IPs statically and I need a way to compare

    – Xi N
    Nov 21 '18 at 1:38
















0















I'm using this code to print some packet info about "all" received and sent packets from all IP addresses. How do I only print packet info of a specific IP address?



this is part of the code:



{
struct ethhdr *eth;
struct iphdr *ip_header;

eth = (struct ethhdr*)skb_mac_header(skb);
ip_header = (struct iphdr *)skb_network_header(skb);

if (HOST_IP_ADDR == ip_header->saddr)
return NF_ACCEPT;

printk("NF_IP_LOCAL_IN hook:n");
printk("src mac %pM, dst mac %pMn", eth->h_source, eth->h_dest);
printk("src IP addr:=%pI4n", &ip_header->saddr);
return NF_ACCEPT;
}









share|improve this question


















  • 1





    Something along the line of if (the ip address == the ip address you want) {print the stuff}?

    – immibis
    Nov 20 '18 at 4:47











  • I tried this option and also I used strcmp, both of them gives errors.

    – Xi N
    Nov 20 '18 at 12:39











  • if (HOST_IP_ADDR == ip_header->saddr) looks like an IP address comparison to me. So you know how to compare IP addresses.

    – immibis
    Nov 20 '18 at 20:44











  • I would like to capture packet info for specific address, my VM has around 10 IP. I assign those IPs statically and I need a way to compare

    – Xi N
    Nov 21 '18 at 1:38














0












0








0








I'm using this code to print some packet info about "all" received and sent packets from all IP addresses. How do I only print packet info of a specific IP address?



this is part of the code:



{
struct ethhdr *eth;
struct iphdr *ip_header;

eth = (struct ethhdr*)skb_mac_header(skb);
ip_header = (struct iphdr *)skb_network_header(skb);

if (HOST_IP_ADDR == ip_header->saddr)
return NF_ACCEPT;

printk("NF_IP_LOCAL_IN hook:n");
printk("src mac %pM, dst mac %pMn", eth->h_source, eth->h_dest);
printk("src IP addr:=%pI4n", &ip_header->saddr);
return NF_ACCEPT;
}









share|improve this question














I'm using this code to print some packet info about "all" received and sent packets from all IP addresses. How do I only print packet info of a specific IP address?



this is part of the code:



{
struct ethhdr *eth;
struct iphdr *ip_header;

eth = (struct ethhdr*)skb_mac_header(skb);
ip_header = (struct iphdr *)skb_network_header(skb);

if (HOST_IP_ADDR == ip_header->saddr)
return NF_ACCEPT;

printk("NF_IP_LOCAL_IN hook:n");
printk("src mac %pM, dst mac %pMn", eth->h_source, eth->h_dest);
printk("src IP addr:=%pI4n", &ip_header->saddr);
return NF_ACCEPT;
}






c hook netfilter






share|improve this question













share|improve this question











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share|improve this question










asked Nov 20 '18 at 4:22









Xi NXi N

154




154








  • 1





    Something along the line of if (the ip address == the ip address you want) {print the stuff}?

    – immibis
    Nov 20 '18 at 4:47











  • I tried this option and also I used strcmp, both of them gives errors.

    – Xi N
    Nov 20 '18 at 12:39











  • if (HOST_IP_ADDR == ip_header->saddr) looks like an IP address comparison to me. So you know how to compare IP addresses.

    – immibis
    Nov 20 '18 at 20:44











  • I would like to capture packet info for specific address, my VM has around 10 IP. I assign those IPs statically and I need a way to compare

    – Xi N
    Nov 21 '18 at 1:38














  • 1





    Something along the line of if (the ip address == the ip address you want) {print the stuff}?

    – immibis
    Nov 20 '18 at 4:47











  • I tried this option and also I used strcmp, both of them gives errors.

    – Xi N
    Nov 20 '18 at 12:39











  • if (HOST_IP_ADDR == ip_header->saddr) looks like an IP address comparison to me. So you know how to compare IP addresses.

    – immibis
    Nov 20 '18 at 20:44











  • I would like to capture packet info for specific address, my VM has around 10 IP. I assign those IPs statically and I need a way to compare

    – Xi N
    Nov 21 '18 at 1:38








1




1





Something along the line of if (the ip address == the ip address you want) {print the stuff}?

– immibis
Nov 20 '18 at 4:47





Something along the line of if (the ip address == the ip address you want) {print the stuff}?

– immibis
Nov 20 '18 at 4:47













I tried this option and also I used strcmp, both of them gives errors.

– Xi N
Nov 20 '18 at 12:39





I tried this option and also I used strcmp, both of them gives errors.

– Xi N
Nov 20 '18 at 12:39













if (HOST_IP_ADDR == ip_header->saddr) looks like an IP address comparison to me. So you know how to compare IP addresses.

– immibis
Nov 20 '18 at 20:44





if (HOST_IP_ADDR == ip_header->saddr) looks like an IP address comparison to me. So you know how to compare IP addresses.

– immibis
Nov 20 '18 at 20:44













I would like to capture packet info for specific address, my VM has around 10 IP. I assign those IPs statically and I need a way to compare

– Xi N
Nov 21 '18 at 1:38





I would like to capture packet info for specific address, my VM has around 10 IP. I assign those IPs statically and I need a way to compare

– Xi N
Nov 21 '18 at 1:38












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