Getting ethernet dest hw_addr
Hi,
i want to write a packet handler for redirecting ethernet packets from an input
device to an output device. actually my problem is to get the dest hw addr from
the computer physically connected to mine.
the only way seems to restrict on ip packets since it seems that routing and
arp needs to be used. so i tried to use ip_route_output_key which fills
skb->dst. Unfortunately i don't have any idea how to get the needed addr from
there. Below is a piece of code showing what i want to do.
Can anyone help me, please?
The favorite way would be to get the addr without limiting to ip...
Thanks and bye
Matthias
static int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct
packet_type *pt) {
struct sk_buff *o_skb = skb_clone(skb, GFP_ATOMIC);
struct iphdr *iph = o_skb->nh.iph;
struct tcphdr *th = (struct tcphdr *) ((char *) o_skb->h.th + (iph->ihl <<
2));
//prevent OS for handling packet
skb->pkt_type = PACKET_OTHERHOST;
if (iph->saddr == ext_addr) { //out->in
//modify header
iph->saddr = gw_int_addr;
iph->daddr = int_addr;
o_skb->dev = devs[2];
} else if (iph->saddr == int_addr) { //in->out
//modify header
iph->saddr = gw_ext_addr;
iph->daddr = ext_addr;
o_skb->dev = devs[1];
} else {
return 0;
}
//route packet
struct flowi flow = {
.nl_u = {
.ip4_u = {
.saddr = iph->saddr,
.daddr = iph->daddr,
.tos = RT_TOS(iph->tos)
}
},
.proto = iph->protocol
};
struct rtable *rt;
ip_route_output_key(, );
o_skb->dst = &(rt->u.dst);
//ip checksum
...works
//broadcast paket to dev -> no dest ethernet addr needed
o_skb->dev->hard_header(
o_skb,
o_skb->dev,
ntohs(o_skb->protocol),
o_skb->dst->neighbour->ha, //destination hw addr needed - seems to be
wrong!
o_skb->dev->dev_addr,
o_skb->len
);
//send packet
o_skb->pkt_type = PACKET_OUTGOING;
dev_queue_xmit(o_skb);
kfree_skb(o_skb);
return 0;
}
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Getting ethernet dest hw_addr
Hi,
i want to write a packet handler for redirecting ethernet packets from an input
device to an output device. actually my problem is to get the dest hw addr from
the computer physically connected to mine.
the only way seems to restrict on ip packets since it seems that routing and
arp needs to be used. so i tried to use ip_route_output_key which fills
skb-dst. Unfortunately i don't have any idea how to get the needed addr from
there. Below is a piece of code showing what i want to do.
Can anyone help me, please?
The favorite way would be to get the addr without limiting to ip...
Thanks and bye
Matthias
static int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct
packet_type *pt) {
struct sk_buff *o_skb = skb_clone(skb, GFP_ATOMIC);
struct iphdr *iph = o_skb-nh.iph;
struct tcphdr *th = (struct tcphdr *) ((char *) o_skb-h.th + (iph-ihl
2));
//prevent OS for handling packet
skb-pkt_type = PACKET_OTHERHOST;
if (iph-saddr == ext_addr) { //out-in
//modify header
iph-saddr = gw_int_addr;
iph-daddr = int_addr;
o_skb-dev = devs[2];
} else if (iph-saddr == int_addr) { //in-out
//modify header
iph-saddr = gw_ext_addr;
iph-daddr = ext_addr;
o_skb-dev = devs[1];
} else {
return 0;
}
//route packet
struct flowi flow = {
.nl_u = {
.ip4_u = {
.saddr = iph-saddr,
.daddr = iph-daddr,
.tos = RT_TOS(iph-tos)
}
},
.proto = iph-protocol
};
struct rtable *rt;
ip_route_output_key(rt, flow);
o_skb-dst = (rt-u.dst);
//ip checksum
...works
//broadcast paket to dev - no dest ethernet addr needed
o_skb-dev-hard_header(
o_skb,
o_skb-dev,
ntohs(o_skb-protocol),
o_skb-dst-neighbour-ha, //destination hw addr needed - seems to be
wrong!
o_skb-dev-dev_addr,
o_skb-len
);
//send packet
o_skb-pkt_type = PACKET_OUTGOING;
dev_queue_xmit(o_skb);
kfree_skb(o_skb);
return 0;
}
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Resending ethernet packets to direct neighbours
Hi, i have a pc with five ethernet devices onto and want to resend ethernet packets coming in from one device to four direct neighbours (distance 1). Therefore i have installed a packet handler receiving skbs. Now i have the following questions: 1) is it enough to change the skb->dev to the output device, rebuild the ethernet header and call dev_queue_xmit()? 2) how to i get the destination ethernet address of the physically direct neighbour within the packet handler? I believe, that i have to use the neighour caches but have not idea how... Any help would be appreciated! Bye Matthias - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Resending ethernet packets to direct neighbours
Hi, i have a pc with five ethernet devices onto and want to resend ethernet packets coming in from one device to four direct neighbours (distance 1). Therefore i have installed a packet handler receiving skbs. Now i have the following questions: 1) is it enough to change the skb-dev to the output device, rebuild the ethernet header and call dev_queue_xmit()? 2) how to i get the destination ethernet address of the physically direct neighbour within the packet handler? I believe, that i have to use the neighour caches but have not idea how... Any help would be appreciated! Bye Matthias - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
RE: Writing data > PAGESIZE into kernel with proc fs
On Tue, Mar 08, 2005 at 20:05:42 +0100, Weber Matthias wrote:
>> is there any chance to signal an EOF when writing data to kernel via proc
>> fs? >> Actually if the length of data is N*PAGE_SIZE it seems not to be
>> detectable.
>> I followed up the "struct file" but haven't found anything that helped...
> End-of-file is signified by closing the file. As usual.
Having only this struct describing an proc entry, i have no idea on how to
detect when the file is closed. For this i expect to register a callback
function but where and how?
struct proc_dir_entry {
unsigned int low_ino;
unsigned short namelen;
const char *name;
mode_t mode;
nlink_t nlink;
uid_t uid;
gid_t gid;
unsigned long size;
struct inode_operations * proc_iops;
struct file_operations * proc_fops;
get_info_t *get_info;
struct module *owner;
struct proc_dir_entry *next, *parent, *subdir;
void *data;
read_proc_t *read_proc;
write_proc_t *write_proc;
atomic_t count; /* use count */
int deleted;/* delete flag */
};
Thanks,
Matthias
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
RE: Writing data PAGESIZE into kernel with proc fs
On Tue, Mar 08, 2005 at 20:05:42 +0100, Weber Matthias wrote:
is there any chance to signal an EOF when writing data to kernel via proc
fs? Actually if the length of data is N*PAGE_SIZE it seems not to be
detectable.
I followed up the struct file but haven't found anything that helped...
End-of-file is signified by closing the file. As usual.
Having only this struct describing an proc entry, i have no idea on how to
detect when the file is closed. For this i expect to register a callback
function but where and how?
struct proc_dir_entry {
unsigned int low_ino;
unsigned short namelen;
const char *name;
mode_t mode;
nlink_t nlink;
uid_t uid;
gid_t gid;
unsigned long size;
struct inode_operations * proc_iops;
struct file_operations * proc_fops;
get_info_t *get_info;
struct module *owner;
struct proc_dir_entry *next, *parent, *subdir;
void *data;
read_proc_t *read_proc;
write_proc_t *write_proc;
atomic_t count; /* use count */
int deleted;/* delete flag */
};
Thanks,
Matthias
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Writing data > PAGESIZE into kernel with proc fs
Hi, is there any chance to signal an EOF when writing data to kernel via proc fs? Actually if the length of data is N*PAGE_SIZE it seems not to be detectable. I followed up the "struct file" but haven't found anything that helped... Any help would be appreciated! Bye Matthias - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Writing data PAGESIZE into kernel with proc fs
Hi, is there any chance to signal an EOF when writing data to kernel via proc fs? Actually if the length of data is N*PAGE_SIZE it seems not to be detectable. I followed up the struct file but haven't found anything that helped... Any help would be appreciated! Bye Matthias - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
