Differential D6612 Diff 17178 sys/netinet/ip_fastfwd.c

Changeset View

Standalone View

sys/netinet/ip_fastfwd.c

Show First 20 Lines • Show All 99 Lines • ▼ Show 20 Lines
#include <netinet/in.h>		#include <netinet/in.h>
#include <netinet/in_kdtrace.h>		#include <netinet/in_kdtrace.h>
#include <netinet/in_systm.h>		#include <netinet/in_systm.h>
#include <netinet/in_var.h>		#include <netinet/in_var.h>
#include <netinet/ip.h>		#include <netinet/ip.h>
#include <netinet/ip_var.h>		#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>		#include <netinet/ip_icmp.h>
#include <netinet/ip_options.h>		#include <netinet/ip_options.h>
		#include <netinet/tcp.h>

#include <machine/in_cksum.h>		#include <machine/in_cksum.h>

static struct sockaddr_in *		static struct sockaddr_in *
ip_findroute(struct route ro, struct in_addr dest, struct mbuf m)		ip_findroute(struct route ro, struct in_addr dest, struct mbuf m)
{		{
struct sockaddr_in *dst;		struct sockaddr_in *dst;
struct rtentry *rt;		struct rtentry *rt;
Show All 39 Lines
ip_tryforward(struct mbuf *m)		ip_tryforward(struct mbuf *m)
{		{
struct ip *ip;		struct ip *ip;
struct mbuf *m0 = NULL;		struct mbuf *m0 = NULL;
struct route ro;		struct route ro;
struct sockaddr_in *dst = NULL;		struct sockaddr_in *dst = NULL;
struct ifnet *ifp;		struct ifnet *ifp;
struct in_addr odest, dest;		struct in_addr odest, dest;
uint16_t ip_len, ip_off;		uint16_t ip_len, ip_off, tcp_len;
int error = 0;		int error = 0;
int mtu;		int mtu;
struct m_tag *fwd_tag = NULL;		struct m_tag *fwd_tag = NULL;

/*		/*
* Are we active and forwarding packets?		* Are we active and forwarding packets?
*/		*/

▲ Show 20 Lines • Show All 252 Lines • ▼ Show 20 Lines	passout:
/*		/*
* Check if packet fits MTU or if hardware will fragment for us		* Check if packet fits MTU or if hardware will fragment for us
*/		*/
if (ro.ro_rt->rt_mtu)		if (ro.ro_rt->rt_mtu)
mtu = min(ro.ro_rt->rt_mtu, ifp->if_mtu);		mtu = min(ro.ro_rt->rt_mtu, ifp->if_mtu);
else		else
mtu = ifp->if_mtu;		mtu = ifp->if_mtu;

if (ip_len <= mtu) {		/*
		* Allow forwarding TSO packets directly if the outbound
		* interface also supports TSO.
		*
		* This is very important when using VMs to perform intra-host
		* packet routing. Since the packet never hits the wire the
		* TCP segments are not actually generated until it reaches a
		* physical interface, and thus we get to see TSO packets on
		* input.
		*
		* Not doing this means that the backend domain (usually Dom0)
		* would have to perform software TCP segmentation for us, which
		* will introduce a huge performance penalty.
		*/
		if ((m->m_pkthdr.csum_flags & CSUM_TSO) != 0 &&
		ip->ip_p == IPPROTO_TCP) {
		struct tcphdr th;
		gnnUnsubmitted Not Done Inline Actions Minor nit but I'd prefer an extra set of braces around the first clause, before the && gnn: Minor nit but I'd prefer an extra set of braces around the first clause, before the &&

		m_copydata(m, sizeof(struct ip), sizeof(struct tcphdr),
		aeUnsubmitted Not Done Inline Actions It isn't safe. There is no guarantee that mbuf's data will be contiguous more than sizeof(struct ip). ae: It isn't safe. There is no guarantee that mbuf's data will be contiguous more than sizeof…
		roygerAuthorUnsubmitted Not Done Inline Actions What's the proper way to get the TCP payload length then? royger: What's the proper way to get the TCP payload length then?
		aeUnsubmitted Not Done Inline Actions The easiest way is m_copydata() with proper offset. ae: The easiest way is m_copydata() with proper offset.
		roygerAuthorUnsubmitted Done Inline Actions Thanks! Will update the patch shortly unless there are other comments. royger: Thanks! Will update the patch shortly unless there are other comments.
		afedorovUnsubmitted Not Done Inline Actions Is this really safe? sizeof(struct ip) == 20 bytes, but IPv4 header can be up to 60 bytes with options. I think you should use ip.ip_hl field as offset. afedorov: Is this really safe? sizeof(struct ip) == 20 bytes, but IPv4 header can be up to 60 bytes with…
		gallatinUnsubmitted Not Done Inline Actions Or check V_ip_doopts != 0, as the code above rejects packets with options if V_ip_doopts is non-zero. gallatin: Or check V_ip_doopts != 0, as the code above rejects packets with options if V_ip_doopts is non…
		(caddr_t) &th);
		tcp_len = ip_len - (sizeof(struct ip) + (th.th_off << 2));
		}

		if ((ip_len <= mtu) \|\| (ip->ip_p == IPPROTO_TCP &&
		(m->m_pkthdr.csum_flags & CSUM_TSO) != 0 &&
		melifaroUnsubmitted Not Done Inline Actions Can this fancy concatenation of 8 conditions be an inline function? melifaro: Can this fancy concatenation of 8 conditions be an inline function?
		rgrimesUnsubmitted Not Done Inline Actions Why, it isnt used in more than one place? rgrimes: Why, it isnt used in more than one place?
		melifaroUnsubmitted Not Done Inline Actions No, I hope it will improve readability. It will also be easier to attach some comments. melifaro: No, I hope it will improve readability. It will also be easier to attach some comments.
		(ifp->if_hwassist & CSUM_TSO) != 0 &&
		(ifp->if_capenable & IFCAP_TSO4) != 0 &&
		(m->m_pkthdr.tso_segsz <= ifp->if_hw_tsomaxsegsize) &&
		howmany(tcp_len, m->m_pkthdr.tso_segsz) <=
		ifp->if_hw_tsomaxsegcount &&
		tcp_len <= ifp->if_hw_tsomax)) {
/*		/*
* Avoid confusing lower layers.		* Avoid confusing lower layers.
*/		*/
m_clrprotoflags(m);		m_clrprotoflags(m);
/*		/*
* Send off the packet via outgoing interface		* Send off the packet via outgoing interface
*/		*/
IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);		IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
▲ Show 20 Lines • Show All 65 Lines • Show Last 20 Lines