Hello All,
I have attached the code snippet for extending tproxy to support sctp
functionality.
For the socket lookup I use:
struct sock *nf_tproxy_get_sock_sctp4(const struct sk_buff *skb){
struct sctp_association *asoc;
union sctp_addr *saddr , *daddr;
struct sctp_transport **transport;
struct sctphdr *sh;
struct sock *sk;
void *temp;
void *temp1;
memset(saddr,0,sizeof(saddr));
memset(daddr,0,sizeof(daddr));
saddr->v4.sin_family = AF_INET;
daddr->v4.sin_family = AF_INET;
sh = sctp_hdr(skb);
temp=&ip_hdr(skb)->saddr;
temp1=&ip_hdr(skb)->daddr;
memcpy(&saddr->v4.sin_addr.s_addr,temp, sizeof(struct in_addr));
memcpy(&daddr->v4.sin_addr.s_addr,temp1, sizeof(struct in_addr));
asoc = __sctp_get_association(saddr, daddr, transport);
if (!asoc)
sk=NULL;
sk = asoc->base.sk;
return sk;
}
This function I plan to invoke from both xt_TPROXY.c and xt_socket.c for
sctp instead of the existing function for tcp and udp.
if(iph->protocol == IPPROTO_TCP || iph->protocol == IPPROTO_UDP){
sk = nf_tproxy_get_sock_v4(dev_net(skb->dev), iph->protocol,
iph->saddr, tgi->laddr ? tgi->laddr :
iph->daddr,
hp->source, tgi->lport ? tgi->lport :
hp->dest,
par->in, true);
}
else
if(iph->protocol == IPPROTO_SCTP){
sk = nf_tproxy_get_sock_sctp4(skb);
}
Have I missed out any condition during the socket lookup ?
What about the icmp support?Can I just reuse the existing functionality by
adding sctp to the list of protocols?
Thanks and Regards,
Maria