Re: 2.6.x kernels - use of exported symbols/functions

[<threadhead@xxxxxx>]

> I think u are doing something wrong in the
> sk_buff filling. I dont know the problem
> precisely.

well i am doing the sk_buff similar to the filling that is done in ipconfig.c.
check the function i am talking about here:
http://lxr.linux.no/source/net/ipv4/ipconfig.c?v=2.6.1#L674

i did parallel to that, some code that should work with tcp packets.
here is the sample code, that should send packets to the network.

[code]
int function (void)
{
    struct packet_tcp{
	struct iphdr iph;
	struct tcphdr tcph;
    };
    struct pseudo_tcp{
	unsigned long s_addr;
	unsigned long d_addr;
	char zero;
	unsigned char protocol;
	unsigned short length;
    };
    struct pseudo_tcp *pseudo;
    struct in_addr saddr, daddr;
    struct sk_buff *skb;
    struct net_device *list;
    int hh_len;
    struct iphdr *h;
    struct tcphdr *th;
    struct packet_tcp *packetbuffer = (struct packet_tcp *)kmalloc(sizeof(struct packet_tcp), GFP_KERNEL);

    saddr.s_addr = inet_addr("192.168.0.3");
    daddr.s_addr = inet_addr("192.168.0.4");

    pseudo = (struct pseudo_tcp *)(packetbuffer + sizeof(struct iphdr) - sizeof(struct pseudo_tcp));
    pseudo->protocol = IPPROTO_TCP;
    pseudo->length = htons(sizeof(struct tcphdr));
    pseudo->s_addr = saddr.s_addr;
    pseudo->d_addr = daddr.s_addr;
    pseudo->zero = 0;

    list = (struct net_device *)kmalloc(sizeof(struct net_device), GFP_KERNEL);

    for(list=dev_base;list->next != NULL;list = list->next){
	if(strcmp(list->name, devname) == 0){
	    printk("<1>device '%s' found\n", devname);
	    break;
	}
    }
    
    hh_len = LL_RESERVED_SPACE(list);

    /* allocate packet */
    skb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) + hh_len + 15, GFP_KERNEL);
    if(!skb) return -EINVAL;
    skb_reserve(skb, hh_len);
    packetbuffer = (struct packet_tcp *)skb_put(skb, sizeof(struct packet_tcp));
    memset(packetbuffer, 0, sizeof(struct packet_tcp));

    /* constructing ip hdr */
    skb->nh.iph = h = &packetbuffer->iph;
    h->version = 4;
    h->ihl = 5;
    h->tos = 0x0;
    h->tot_len = htons(sizeof(struct packet_tcp));
    h->frag_off = htons(IP_DF); /* 0x4000, don't fragment packet */
    h->ttl = 64;
    h->protocol = IPPROTO_TCP;
    h->daddr = daddr.s_addr;
    h->saddr = saddr.s_addr;
    h->check = ip_fast_csum((unsigned char *)h, h->ihl);

    /* now tcp header */
    skb->h.th = th = &packetbuffer->tcph;
    th->source = htons(12345);
    th->dest = htons(22);
    th->seq = 0xfee1;
    th->ack_seq = htonl(0xdead);
    th->doff = 5;
    th->fin = 1;
    th->syn = 0;
    th->rst = 0;
    th->psh = 0;
    th->ack = 0;
    th->urg = 0;
    th->window = htons(0xeeff);
    th->urg_ptr = 0;
    th->check = csum((unsigned short *)pseudo, sizeof(struct tcphdr) + sizeof(struct pseudo_tcp));
    
    skb->dev = list;
    skb->protocol = htons(ETH_P_IP);

    dev_queue_xmit(skb);

    return -EINVAL;
}
[/code]

thanks for the effort

and best regards
threadhead
______________________________________________________________________________
Extra-Konto: 2,50 %* Zinsen p. a. ab dem ersten Euro! Nur hier mit 25
Euro-Tankgutschein & ExtraPrämie! https://extrakonto.web.de/?mc=021110


--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive:       http://mail.nl.linux.org/kernelnewbies/
FAQ:           http://kernelnewbies.org/faq/