/*
* Check if this packet has an active SA and needs to be dropped instead
* of forwarded.
* Called from ip_input().
* 1 = drop packet, 0 = forward packet.
*/
int
ip_ipsec_fwd(struct mbuf *m)
{
#ifdef IPSEC
struct m_tag *mtag;
struct tdb_ident *tdbi;
struct secpolicy *sp;
int error;
mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
if (mtag != NULL) {
tdbi = (struct tdb_ident *)(mtag + 1);
sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
} else {
sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
IP_FORWARDING, &error);
}
if (sp == NULL) { /* NB: can happen if error */
/*XXX error stat???*/
DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
return 1;
}
/*
* Check security policy against packet attributes.
*/
error = ipsec_in_reject(sp, m);
KEY_FREESP(&sp);
if (error) {
IPSTAT_INC(ips_cantforward);
return 1;
}
#endif /* IPSEC */
return 0;
}
/*
* Check if protocol type doesn't have a further header and do IPSEC
* decryption or reject right now. Protocols with further headers get
* their IPSEC treatment within the protocol specific processing.
* Called from ip6_input().
* 1 = drop packet, 0 = continue processing packet.
*/
int
ip6_ipsec_input(struct mbuf *m, int nxt)
{
#ifdef IPSEC
struct m_tag *mtag;
struct tdb_ident *tdbi;
struct secpolicy *sp;
int s, error;
/*
* enforce IPsec policy checking if we are seeing last header.
* note that we do not visit this with protocols with pcb layer
* code - like udp/tcp/raw ip.
*/
if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
ipsec6_in_reject(m, NULL)) {
/*
* Check if the packet has already had IPsec processing
* done. If so, then just pass it along. This tag gets
* set during AH, ESP, etc. input handling, before the
* packet is returned to the ip input queue for delivery.
*/
mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
s = splnet();
if (mtag != NULL) {
tdbi = (struct tdb_ident *)(mtag + 1);
sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
} else {
sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
IP_FORWARDING, &error);
}
if (sp != NULL) {
/*
* Check security policy against packet attributes.
*/
error = ipsec_in_reject(sp, m);
KEY_FREESP(&sp);
} else {
/* XXX error stat??? */
error = EINVAL;
DPRINTF(("%s: no SP, packet discarded\n", __func__));/*XXX*/
return 1;
}
splx(s);
if (error)
return 1;
}
#endif /* IPSEC */
return 0;
}
/*
*
* Called from ip_output().
* 1 = drop packet, 0 = continue processing packet,
* -1 = packet was reinjected and stop processing packet
*/
int
ip_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error)
{
#ifdef IPSEC
struct secpolicy *sp = NULL;
struct ip *ip = mtod(*m, struct ip *);
struct tdb_ident *tdbi;
struct m_tag *mtag;
int s;
/*
* Check the security policy (SP) for the packet and, if
* required, do IPsec-related processing. There are two
* cases here; the first time a packet is sent through
* it will be untagged and handled by ipsec4_checkpolicy.
* If the packet is resubmitted to ip_output (e.g. after
* AH, ESP, etc. processing), there will be a tag to bypass
* the lookup and related policy checking.
*/
mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
s = splnet();
if (mtag != NULL) {
tdbi = (struct tdb_ident *)(mtag + 1);
sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
if (sp == NULL)
*error = -EINVAL; /* force silent drop */
m_tag_delete(*m, mtag);
} else {
sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
error, inp);
}
/*
* There are four return cases:
* sp != NULL apply IPsec policy
* sp == NULL, error == 0 no IPsec handling needed
* sp == NULL, error == -EINVAL discard packet w/o error
* sp == NULL, error != 0 discard packet, report error
*/
if (sp != NULL) {
/* Loop detection, check if ipsec processing already done */
KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
for (mtag = m_tag_first(*m); mtag != NULL;
mtag = m_tag_next(*m, mtag)) {
if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
continue;
if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
continue;
/*
* Check if policy has an SA associated with it.
* This can happen when an SP has yet to acquire
* an SA; e.g. on first reference. If it occurs,
* then we let ipsec4_process_packet do its thing.
*/
if (sp->req->sav == NULL)
break;
tdbi = (struct tdb_ident *)(mtag + 1);
if (tdbi->spi == sp->req->sav->spi &&
tdbi->proto == sp->req->sav->sah->saidx.proto &&
bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
sizeof (union sockaddr_union)) == 0) {
/*
* No IPsec processing is needed, free
* reference to SP.
*
* NB: null pointer to avoid free at
* done: below.
*/
KEY_FREESP(&sp), sp = NULL;
splx(s);
goto done;
}
}
/*
* Do delayed checksums now because we send before
* this is done in the normal processing path.
*/
if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
in_delayed_cksum(*m);
(*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
}
#ifdef SCTP
if ((*m)->m_pkthdr.csum_flags & CSUM_SCTP) {
sctp_delayed_cksum(*m, (uint32_t)(ip->ip_hl << 2));
(*m)->m_pkthdr.csum_flags &= ~CSUM_SCTP;
}
#endif
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
/* NB: callee frees mbuf */
*error = ipsec4_process_packet(*m, sp->req, *flags, 0);
if (*error == EJUSTRETURN) {
/*
* We had a SP with a level of 'use' and no SA. We
* will just continue to process the packet without
* IPsec processing and return without error.
*/
*error = 0;
ip->ip_len = ntohs(ip->ip_len);
ip->ip_off = ntohs(ip->ip_off);
goto done;
}
/*
* Preserve KAME behaviour: ENOENT can be returned
* when an SA acquire is in progress. Don't propagate
* this to user-level; it confuses applications.
*
* XXX this will go away when the SADB is redone.
*/
if (*error == ENOENT)
*error = 0;
splx(s);
goto reinjected;
} else { /* sp == NULL */
splx(s);
if (*error != 0) {
/*
* Hack: -EINVAL is used to signal that a packet
* should be silently discarded. This is typically
* because we asked key management for an SA and
* it was delayed (e.g. kicked up to IKE).
*/
if (*error == -EINVAL)
*error = 0;
goto bad;
} else {
/* No IPsec processing for this packet. */
}
}
done:
if (sp != NULL)
KEY_FREESP(&sp);
return 0;
reinjected:
if (sp != NULL)
KEY_FREESP(&sp);
return -1;
bad:
if (sp != NULL)
KEY_FREESP(&sp);
return 1;
#endif /* IPSEC */
return 0;
}
int
ip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error,
struct ifnet **ifp, struct secpolicy **sp)
{
#ifdef IPSEC
struct tdb_ident *tdbi;
struct m_tag *mtag;
/* XXX int s; */
if (sp == NULL)
return 1;
mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
if (mtag != NULL) {
tdbi = (struct tdb_ident *)(mtag + 1);
*sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
if (*sp == NULL)
*error = -EINVAL; /* force silent drop */
m_tag_delete(*m, mtag);
} else {
*sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
error, inp);
}
/*
* There are four return cases:
* sp != NULL apply IPsec policy
* sp == NULL, error == 0 no IPsec handling needed
* sp == NULL, error == -EINVAL discard packet w/o error
* sp == NULL, error != 0 discard packet, report error
*/
if (*sp != NULL) {
/* Loop detection, check if ipsec processing already done */
KASSERT((*sp)->req != NULL, ("ip_output: no ipsec request"));
for (mtag = m_tag_first(*m); mtag != NULL;
mtag = m_tag_next(*m, mtag)) {
if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
continue;
if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
continue;
/*
* Check if policy has an SA associated with it.
* This can happen when an SP has yet to acquire
* an SA; e.g. on first reference. If it occurs,
* then we let ipsec4_process_packet do its thing.
*/
if ((*sp)->req->sav == NULL)
break;
tdbi = (struct tdb_ident *)(mtag + 1);
if (tdbi->spi == (*sp)->req->sav->spi &&
tdbi->proto == (*sp)->req->sav->sah->saidx.proto &&
bcmp(&tdbi->dst, &(*sp)->req->sav->sah->saidx.dst,
sizeof (union sockaddr_union)) == 0) {
/*
* No IPsec processing is needed, free
* reference to SP.
*
* NB: null pointer to avoid free at
* done: below.
*/
KEY_FREESP(sp), *sp = NULL;
/* XXX splx(s); */
goto done;
}
}
/*
* Do delayed checksums now because we send before
* this is done in the normal processing path.
*/
if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
ipseclog((LOG_DEBUG,
"%s: we do not support IPv4 over IPv6", __func__));
#ifdef INET
in_delayed_cksum(*m);
#endif
(*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
}
/*
* Preserve KAME behaviour: ENOENT can be returned
* when an SA acquire is in progress. Don't propagate
* this to user-level; it confuses applications.
*
* XXX this will go away when the SADB is redone.
*/
if (*error == ENOENT)
*error = 0;
goto do_ipsec;
} else { /* sp == NULL */
if (*error != 0) {
/*
* Hack: -EINVAL is used to signal that a packet
* should be silently discarded. This is typically
* because we asked key management for an SA and
* it was delayed (e.g. kicked up to IKE).
*/
if (*error == -EINVAL)
*error = 0;
goto bad;
} else {
/* No IPsec processing for this packet. */
}
}
done:
return 0;
do_ipsec:
return -1;
bad:
return 1;
#endif /* IPSEC */
return 0;
}