int
udp6_input(struct mbuf **mp, int *offp, int proto)
{
struct mbuf *m = *mp;
struct ifnet *ifp;
struct ip6_hdr *ip6;
struct udphdr *uh;
struct inpcb *inp;
struct inpcbinfo *pcbinfo;
struct udpcb *up;
int off = *offp;
int cscov_partial;
int plen, ulen;
struct sockaddr_in6 fromsa;
struct m_tag *fwd_tag;
uint16_t uh_sum;
uint8_t nxt;
ifp = m->m_pkthdr.rcvif;
ip6 = mtod(m, struct ip6_hdr *);
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
ip6 = mtod(m, struct ip6_hdr *);
uh = (struct udphdr *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
if (!uh)
return (IPPROTO_DONE);
#endif
UDPSTAT_INC(udps_ipackets);
/*
* Destination port of 0 is illegal, based on RFC768.
*/
if (uh->uh_dport == 0)
goto badunlocked;
plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
ulen = ntohs((u_short)uh->uh_ulen);
nxt = proto;
cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
if (nxt == IPPROTO_UDPLITE) {
/* Zero means checksum over the complete packet. */
if (ulen == 0)
ulen = plen;
if (ulen == plen)
cscov_partial = 0;
if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
/* XXX: What is the right UDPLite MIB counter? */
goto badunlocked;
}
if (uh->uh_sum == 0) {
/* XXX: What is the right UDPLite MIB counter? */
goto badunlocked;
}
} else {
if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
UDPSTAT_INC(udps_badlen);
goto badunlocked;
}
if (uh->uh_sum == 0) {
UDPSTAT_INC(udps_nosum);
goto badunlocked;
}
}
if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
!cscov_partial) {
if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
uh_sum = m->m_pkthdr.csum_data;
else
uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
m->m_pkthdr.csum_data);
uh_sum ^= 0xffff;
} else
uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
if (uh_sum != 0) {
UDPSTAT_INC(udps_badsum);
goto badunlocked;
}
/*
* Construct sockaddr format source address.
*/
init_sin6(&fromsa, m);
fromsa.sin6_port = uh->uh_sport;
pcbinfo = udp_get_inpcbinfo(nxt);
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
struct inpcb *last;
struct inpcbhead *pcblist;
struct ip6_moptions *imo;
INP_INFO_RLOCK(pcbinfo);
/*
* In the event that laddr should be set to the link-local
* address (this happens in RIPng), the multicast address
* specified in the received packet will not match laddr. To
* handle this situation, matching is relaxed if the
* receiving interface is the same as one specified in the
* socket and if the destination multicast address matches
* one of the multicast groups specified in the socket.
*/
/*
* KAME note: traditionally we dropped udpiphdr from mbuf
* here. We need udphdr for IPsec processing so we do that
* later.
*/
pcblist = udp_get_pcblist(nxt);
last = NULL;
LIST_FOREACH(inp, pcblist, inp_list) {
if ((inp->inp_vflag & INP_IPV6) == 0)
continue;
if (inp->inp_lport != uh->uh_dport)
continue;
if (inp->inp_fport != 0 &&
inp->inp_fport != uh->uh_sport)
continue;
if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
&ip6->ip6_dst))
continue;
}
if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
&ip6->ip6_src) ||
inp->inp_fport != uh->uh_sport)
continue;
}
/*
* XXXRW: Because we weren't holding either the inpcb
* or the hash lock when we checked for a match
* before, we should probably recheck now that the
* inpcb lock is (supposed to be) held.
*/
/*
* Handle socket delivery policy for any-source
* and source-specific multicast. [RFC3678]
*/
imo = inp->in6p_moptions;
if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
struct sockaddr_in6 mcaddr;
int blocked;
INP_RLOCK(inp);
bzero(&mcaddr, sizeof(struct sockaddr_in6));
mcaddr.sin6_len = sizeof(struct sockaddr_in6);
mcaddr.sin6_family = AF_INET6;
mcaddr.sin6_addr = ip6->ip6_dst;
blocked = im6o_mc_filter(imo, ifp,
(struct sockaddr *)&mcaddr,
(struct sockaddr *)&fromsa);
if (blocked != MCAST_PASS) {
if (blocked == MCAST_NOTGMEMBER)
IP6STAT_INC(ip6s_notmember);
if (blocked == MCAST_NOTSMEMBER ||
blocked == MCAST_MUTED)
UDPSTAT_INC(udps_filtermcast);
INP_RUNLOCK(inp); /* XXX */
continue;
}
INP_RUNLOCK(inp);
}
if (last != NULL) {
struct mbuf *n;
if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
INP_RLOCK(last);
UDP_PROBE(receive, NULL, last, ip6,
last, uh);
if (udp6_append(last, n, off, &fromsa))
goto inp_lost;
INP_RUNLOCK(last);
}
}
last = inp;
/*
* Don't look for additional matches if this one does
* not have either the SO_REUSEPORT or SO_REUSEADDR
* socket options set. This heuristic avoids
* searching through all pcbs in the common case of a
* non-shared port. It assumes that an application
* will never clear these options after setting them.
*/
if ((last->inp_socket->so_options &
(SO_REUSEPORT|SO_REUSEADDR)) == 0)
break;
}
if (last == NULL) {
/*
* No matching pcb found; discard datagram. (No need
* to send an ICMP Port Unreachable for a broadcast
* or multicast datgram.)
*/
UDPSTAT_INC(udps_noport);
UDPSTAT_INC(udps_noportmcast);
goto badheadlocked;
}
INP_RLOCK(last);
INP_INFO_RUNLOCK(pcbinfo);
UDP_PROBE(receive, NULL, last, ip6, last, uh);
if (udp6_append(last, m, off, &fromsa) == 0)
INP_RUNLOCK(last);
inp_lost:
return (IPPROTO_DONE);
}
/*
* Locate pcb for datagram.
*/
/*
* Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
*/
if ((m->m_flags & M_IP6_NEXTHOP) &&
(fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
struct sockaddr_in6 *next_hop6;
next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
/*
* Transparently forwarded. Pretend to be the destination.
* Already got one like this?
*/
inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
if (!inp) {
/*
* It's new. Try to find the ambushing socket.
* Because we've rewritten the destination address,
* any hardware-generated hash is ignored.
*/
inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
uh->uh_sport, &next_hop6->sin6_addr,
next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
uh->uh_dport, INPLOOKUP_WILDCARD |
INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
}
/* Remove the tag from the packet. We don't need it anymore. */
m_tag_delete(m, fwd_tag);
m->m_flags &= ~M_IP6_NEXTHOP;
} else
inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
m->m_pkthdr.rcvif, m);
if (inp == NULL) {
if (udp_log_in_vain) {
char ip6bufs[INET6_ADDRSTRLEN];
char ip6bufd[INET6_ADDRSTRLEN];
log(LOG_INFO,
"Connection attempt to UDP [%s]:%d from [%s]:%d\n",
ip6_sprintf(ip6bufd, &ip6->ip6_dst),
ntohs(uh->uh_dport),
ip6_sprintf(ip6bufs, &ip6->ip6_src),
ntohs(uh->uh_sport));
}
UDPSTAT_INC(udps_noport);
if (m->m_flags & M_MCAST) {
printf("UDP6: M_MCAST is set in a unicast packet.\n");
UDPSTAT_INC(udps_noportmcast);
goto badunlocked;
}
if (V_udp_blackhole)
goto badunlocked;
if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
goto badunlocked;
icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
return (IPPROTO_DONE);
}
INP_RLOCK_ASSERT(inp);
up = intoudpcb(inp);
if (cscov_partial) {
if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
INP_RUNLOCK(inp);
m_freem(m);
return (IPPROTO_DONE);
}
}
UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
if (udp6_append(inp, m, off, &fromsa) == 0)
INP_RUNLOCK(inp);
return (IPPROTO_DONE);
badheadlocked:
INP_INFO_RUNLOCK(pcbinfo);
badunlocked:
if (m)
m_freem(m);
return (IPPROTO_DONE);
}
static int
udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
struct mbuf *control, struct thread *td)
{
u_int32_t ulen = m->m_pkthdr.len;
u_int32_t plen = sizeof(struct udphdr) + ulen;
struct ip6_hdr *ip6;
struct udphdr *udp6;
struct in6_addr *laddr, *faddr, in6a;
struct sockaddr_in6 *sin6 = NULL;
int cscov_partial = 0;
int scope_ambiguous = 0;
u_short fport;
int error = 0;
uint8_t nxt;
uint16_t cscov = 0;
struct ip6_pktopts *optp, opt;
int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
int flags;
struct sockaddr_in6 tmp;
INP_WLOCK_ASSERT(inp);
INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
if (addr6) {
/* addr6 has been validated in udp6_send(). */
sin6 = (struct sockaddr_in6 *)addr6;
/* protect *sin6 from overwrites */
tmp = *sin6;
sin6 = &tmp;
/*
* Application should provide a proper zone ID or the use of
* default zone IDs should be enabled. Unfortunately, some
* applications do not behave as it should, so we need a
* workaround. Even if an appropriate ID is not determined,
* we'll see if we can determine the outgoing interface. If we
* can, determine the zone ID based on the interface below.
*/
if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
scope_ambiguous = 1;
if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
return (error);
}
nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
IPPROTO_UDP : IPPROTO_UDPLITE;
if (control) {
if ((error = ip6_setpktopts(control, &opt,
inp->in6p_outputopts, td->td_ucred, nxt)) != 0)
goto release;
optp = &opt;
} else
optp = inp->in6p_outputopts;
if (sin6) {
faddr = &sin6->sin6_addr;
/*
* Since we saw no essential reason for calling in_pcbconnect,
* we get rid of such kind of logic, and call in6_selectsrc
* and in6_pcbsetport in order to fill in the local address
* and the local port.
*/
if (sin6->sin6_port == 0) {
error = EADDRNOTAVAIL;
goto release;
}
if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
/* how about ::ffff:0.0.0.0 case? */
error = EISCONN;
goto release;
}
fport = sin6->sin6_port; /* allow 0 port */
if (IN6_IS_ADDR_V4MAPPED(faddr)) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
/*
* I believe we should explicitly discard the
* packet when mapped addresses are disabled,
* rather than send the packet as an IPv6 one.
* If we chose the latter approach, the packet
* might be sent out on the wire based on the
* default route, the situation which we'd
* probably want to avoid.
* (20010421 [email protected])
*/
error = EINVAL;
goto release;
}
if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
!IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
/*
* when remote addr is an IPv4-mapped address,
* local addr should not be an IPv6 address,
* since you cannot determine how to map IPv6
* source address to IPv4.
*/
error = EINVAL;
goto release;
}
af = AF_INET;
}
if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
error = in6_selectsrc_socket(sin6, optp, inp,
td->td_ucred, scope_ambiguous, &in6a, NULL);
if (error)
goto release;
laddr = &in6a;
} else
laddr = &inp->in6p_laddr; /* XXX */
if (laddr == NULL) {
if (error == 0)
error = EADDRNOTAVAIL;
goto release;
}
if (inp->inp_lport == 0 &&
(error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
/* Undo an address bind that may have occurred. */
inp->in6p_laddr = in6addr_any;
goto release;
}
} else {
if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
error = ENOTCONN;
goto release;
}
if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
/*
* XXX: this case would happen when the
* application sets the V6ONLY flag after
* connecting the foreign address.
* Such applications should be fixed,
* so we bark here.
*/
log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
"option was set for a connected socket\n");
error = EINVAL;
goto release;
} else
af = AF_INET;
}
laddr = &inp->in6p_laddr;
faddr = &inp->in6p_faddr;
fport = inp->inp_fport;
}
if (af == AF_INET)
hlen = sizeof(struct ip);
/*
* Calculate data length and get a mbuf
* for UDP and IP6 headers.
*/
M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
if (m == NULL) {
error = ENOBUFS;
goto release;
}
/*
* Stuff checksum and output datagram.
*/
udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
udp6->uh_dport = fport;
if (nxt == IPPROTO_UDPLITE) {
struct udpcb *up;
up = intoudpcb(inp);
cscov = up->u_txcslen;
if (cscov >= plen)
cscov = 0;
udp6->uh_ulen = htons(cscov);
/*
* For UDP-Lite, checksum coverage length of zero means
* the entire UDPLite packet is covered by the checksum.
*/
cscov_partial = (cscov == 0) ? 0 : 1;
} else if (plen <= 0xffff)
udp6->uh_ulen = htons((u_short)plen);
else
udp6->uh_ulen = 0;
udp6->uh_sum = 0;
switch (af) {
case AF_INET6:
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_flow = inp->inp_flow & IPV6_FLOWINFO_MASK;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
ip6->ip6_plen = htons((u_short)plen);
ip6->ip6_nxt = nxt;
ip6->ip6_hlim = in6_selecthlim(inp, NULL);
ip6->ip6_src = *laddr;
ip6->ip6_dst = *faddr;
if (cscov_partial) {
if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
sizeof(struct ip6_hdr), plen, cscov)) == 0)
udp6->uh_sum = 0xffff;
} else {
udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
}
#ifdef RSS
{
uint32_t hash_val, hash_type;
uint8_t pr;
pr = inp->inp_socket->so_proto->pr_protocol;
/*
* Calculate an appropriate RSS hash for UDP and
* UDP Lite.
*
* The called function will take care of figuring out
* whether a 2-tuple or 4-tuple hash is required based
* on the currently configured scheme.
*
* Later later on connected socket values should be
* cached in the inpcb and reused, rather than constantly
* re-calculating it.
*
* UDP Lite is a different protocol number and will
* likely end up being hashed as a 2-tuple until
* RSS / NICs grow UDP Lite protocol awareness.
*/
if (rss_proto_software_hash_v6(faddr, laddr, fport,
inp->inp_lport, pr, &hash_val, &hash_type) == 0) {
m->m_pkthdr.flowid = hash_val;
M_HASHTYPE_SET(m, hash_type);
}
}
#endif
flags = 0;
#ifdef RSS
/*
* Don't override with the inp cached flowid.
*
* Until the whole UDP path is vetted, it may actually
* be incorrect.
*/
flags |= IP_NODEFAULTFLOWID;
#endif
UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
UDPSTAT_INC(udps_opackets);
error = ip6_output(m, optp, &inp->inp_route6, flags,
inp->in6p_moptions, NULL, inp);
break;
case AF_INET:
error = EAFNOSUPPORT;
goto release;
}
goto releaseopt;
release:
m_freem(m);
releaseopt:
if (control) {
ip6_clearpktopts(&opt, -1);
m_freem(control);
}
return (error);
}
/*
* off is an offset where TCP/UDP/ICMP6 header starts.
* len is a total length of a transport segment.
* (e.g. TCP header + TCP payload)
*/
int
in6_cksum(u_int8_t *ip6hdr, u_int8_t nxt, u_int32_t off, u_int32_t len)
{
return (in6_cksum_partial(ip6hdr, nxt, off, len, len));
}
