/*
* if_simloop()
*
* This function is to support software emulation of hardware loopback,
* i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
* hear their own broadcasts, we create a copy of the packet that we
* would normally receive via a hardware loopback.
*
* This function expects the packet to include the media header of length hlen.
*/
int
if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen)
{
int isr;
M_ASSERTPKTHDR(m);
m_tag_delete_nonpersistent(m);
m->m_pkthdr.rcvif = ifp;
#if 0
/*
* Let BPF see incoming packet in the following manner:
* - Emulated packet loopback for a simplex interface
* (net/if_ethersubr.c)
* -> passes it to ifp's BPF
* - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c)
* -> not passes it to any BPF
* - Normal packet loopback from myself to myself (net/if_loop.c)
* -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0)
*/
if (hlen > 0) {
if (bpf_peers_present(ifp->if_bpf)) {
bpf_mtap(ifp->if_bpf, m);
}
} else {
if (bpf_peers_present(V_loif->if_bpf)) {
if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) {
/* XXX beware sizeof(af) != 4 */
u_int32_t af1 = af;
/*
* We need to prepend the address family.
*/
bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m);
}
}
}
#endif
/* Strip away media header */
if (hlen > 0) {
m_adj(m, hlen);
#ifndef __NO_STRICT_ALIGNMENT
/*
* Some archs do not like unaligned data, so
* we move data down in the first mbuf.
*/
if (mtod(m, vm_offset_t) & 3) {
KASSERT(hlen >= 3, ("if_simloop: hlen too small"));
bcopy(m->m_data,
(char *)(mtod(m, vm_offset_t)
- (mtod(m, vm_offset_t) & 3)),
m->m_len);
m->m_data -= (mtod(m,vm_offset_t) & 3);
}
#endif
}
/* Deliver to upper layer protocol */
switch (af) {
#ifdef INET
case AF_INET:
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
m->m_flags |= M_LOOP;
isr = NETISR_IPV6;
break;
#endif
#ifdef IPX
case AF_IPX:
isr = NETISR_IPX;
break;
#endif
#ifdef NETATALK
case AF_APPLETALK:
isr = NETISR_ATALK2;
break;
#endif
default:
printf("if_simloop: can't handle af=%d\n", af);
m_freem(m);
return (EAFNOSUPPORT);
}
ifp->if_ipackets++;
ifp->if_ibytes += m->m_pkthdr.len;
netisr_queue(isr, m); /* mbuf is free'd on failure. */
return (0);
}
int
looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct rtentry *rt)
{
pktqueue_t *pktq = NULL;
struct ifqueue *ifq = NULL;
int s, isr = -1;
int csum_flags;
size_t pktlen;
MCLAIM(m, ifp->if_mowner);
KASSERT(KERNEL_LOCKED_P());
if ((m->m_flags & M_PKTHDR) == 0)
panic("looutput: no header mbuf");
if (ifp->if_flags & IFF_LOOPBACK)
bpf_mtap_af(ifp, dst->sa_family, m);
m->m_pkthdr.rcvif = ifp;
if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
m_freem(m);
return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
}
pktlen = m->m_pkthdr.len;
ifp->if_opackets++;
ifp->if_obytes += pktlen;
#ifdef ALTQ
/*
* ALTQ on the loopback interface is just for debugging. It's
* used only for loopback interfaces, not for a simplex interface.
*/
if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
ifp->if_start == lostart) {
struct altq_pktattr pktattr;
int error;
/*
* If the queueing discipline needs packet classification,
* do it before prepending the link headers.
*/
IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
if (m == NULL)
return (ENOBUFS);
*(mtod(m, uint32_t *)) = dst->sa_family;
s = splnet();
IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
(*ifp->if_start)(ifp);
splx(s);
return (error);
}
#endif /* ALTQ */
m_tag_delete_nonpersistent(m);
#ifdef MPLS
if (rt != NULL && rt_gettag(rt) != NULL &&
rt_gettag(rt)->sa_family == AF_MPLS &&
(m->m_flags & (M_MCAST | M_BCAST)) == 0) {
union mpls_shim msh;
msh.s_addr = MPLS_GETSADDR(rt);
if (msh.shim.label != MPLS_LABEL_IMPLNULL) {
ifq = &mplsintrq;
isr = NETISR_MPLS;
}
}
if (isr != NETISR_MPLS)
#endif
switch (dst->sa_family) {
#ifdef INET
case AF_INET:
csum_flags = m->m_pkthdr.csum_flags;
KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0);
if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
ip_undefer_csum(m, 0, csum_flags);
}
m->m_pkthdr.csum_flags = 0;
pktq = ip_pktq;
break;
#endif
#ifdef INET6
case AF_INET6:
csum_flags = m->m_pkthdr.csum_flags;
KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0);
if (csum_flags != 0 &&
IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
ip6_undefer_csum(m, 0, csum_flags);
}
m->m_pkthdr.csum_flags = 0;
m->m_flags |= M_LOOP;
pktq = ip6_pktq;
break;
#endif
#ifdef IPX
case AF_IPX:
ifq = &ipxintrq;
isr = NETISR_IPX;
break;
#endif
#ifdef NETATALK
case AF_APPLETALK:
ifq = &atintrq2;
isr = NETISR_ATALK;
break;
#endif
default:
printf("%s: can't handle af%d\n", ifp->if_xname,
dst->sa_family);
m_freem(m);
return (EAFNOSUPPORT);
}
s = splnet();
if (__predict_true(pktq)) {
int error = 0;
if (__predict_true(pktq_enqueue(pktq, m, 0))) {
ifp->if_ipackets++;
ifp->if_ibytes += pktlen;
} else {
m_freem(m);
error = ENOBUFS;
}
splx(s);
return error;
}
if (IF_QFULL(ifq)) {
IF_DROP(ifq);
m_freem(m);
splx(s);
return (ENOBUFS);
}
IF_ENQUEUE(ifq, m);
schednetisr(isr);
ifp->if_ipackets++;
ifp->if_ibytes += m->m_pkthdr.len;
splx(s);
return (0);
}
int
looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct rtentry *rt)
{
int s, isr;
struct ifqueue *ifq = NULL;
MCLAIM(m, ifp->if_mowner);
if ((m->m_flags & M_PKTHDR) == 0)
panic("looutput: no header mbuf");
#if NBPFILTER > 0
if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK))
bpf_mtap_af(ifp->if_bpf, dst->sa_family, m);
#endif
m->m_pkthdr.rcvif = ifp;
if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
m_freem(m);
return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
}
ifp->if_opackets++;
ifp->if_obytes += m->m_pkthdr.len;
#ifdef ALTQ
/*
* ALTQ on the loopback interface is just for debugging. It's
* used only for loopback interfaces, not for a simplex interface.
*/
if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
ifp->if_start == lostart) {
struct altq_pktattr pktattr;
int error;
/*
* If the queueing discipline needs packet classification,
* do it before prepending the link headers.
*/
IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
if (m == NULL)
return (ENOBUFS);
*(mtod(m, uint32_t *)) = dst->sa_family;
s = splnet();
IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
(*ifp->if_start)(ifp);
splx(s);
return (error);
}
#endif /* ALTQ */
m_tag_delete_nonpersistent(m);
switch (dst->sa_family) {
#ifdef INET
case AF_INET:
ifq = &ipintrq;
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
m->m_flags |= M_LOOP;
ifq = &ip6intrq;
isr = NETISR_IPV6;
break;
#endif
#ifdef ISO
case AF_ISO:
ifq = &clnlintrq;
isr = NETISR_ISO;
break;
#endif
#ifdef IPX
case AF_IPX:
ifq = &ipxintrq;
isr = NETISR_IPX;
break;
#endif
#ifdef NETATALK
case AF_APPLETALK:
ifq = &atintrq2;
isr = NETISR_ATALK;
break;
#endif
default:
printf("%s: can't handle af%d\n", ifp->if_xname,
dst->sa_family);
m_freem(m);
return (EAFNOSUPPORT);
}
s = splnet();
if (IF_QFULL(ifq)) {
IF_DROP(ifq);
m_freem(m);
splx(s);
return (ENOBUFS);
}
IF_ENQUEUE(ifq, m);
// schednetisr(isr);
ifp->if_ipackets++;
ifp->if_ibytes += m->m_pkthdr.len;
splx(s);
return (0);
}
