int
ipcomp4_input(struct mbuf **mp, int *offp, int proto)
{
struct mbuf *m;
int off;
m = *mp;
off = *offp;
mp = NULL;
ipsec4_common_input(m, off, IPPROTO_IPCOMP);
return (IPPROTO_DONE);
}
int
ah4_input(struct mbuf **mp, int *offp, int proto)
{
struct mbuf *m;
int off;
m = *mp;
off = *offp;
*mp = NULL;
ipsec4_common_input(m, off, IPPROTO_AH);
return (IPPROTO_DONE);
}
/*
* Potentially decap ESP in UDP frame. Check for an ESP header
* and optional marker; if present, strip the UDP header and
* push the result through IPSec.
*
* Returns mbuf to be processed (potentially re-allocated) or
* NULL if consumed and/or processed.
*/
static struct mbuf *
udp4_espdecap(struct inpcb *inp, struct mbuf *m, int off)
{
size_t minlen, payload, skip, iphlen;
caddr_t data;
struct udpcb *up;
struct m_tag *tag;
struct udphdr *udphdr;
struct ip *ip;
INP_RLOCK_ASSERT(inp);
/*
* Pull up data so the longest case is contiguous:
* IP/UDP hdr + non ESP marker + ESP hdr.
*/
minlen = off + sizeof(uint64_t) + sizeof(struct esp);
if (minlen > m->m_pkthdr.len)
minlen = m->m_pkthdr.len;
if ((m = m_pullup(m, minlen)) == NULL) {
IPSECSTAT_INC(ips_in_inval);
return (NULL); /* Bypass caller processing. */
}
data = mtod(m, caddr_t); /* Points to ip header. */
payload = m->m_len - off; /* Size of payload. */
if (payload == 1 && data[off] == '\xff')
return (m); /* NB: keepalive packet, no decap. */
up = intoudpcb(inp);
KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
KASSERT((up->u_flags & UF_ESPINUDP_ALL) != 0,
("u_flags 0x%x", up->u_flags));
/*
* Check that the payload is large enough to hold an
* ESP header and compute the amount of data to remove.
*
* NB: the caller has already done a pullup for us.
* XXX can we assume alignment and eliminate bcopys?
*/
if (up->u_flags & UF_ESPINUDP_NON_IKE) {
/*
* draft-ietf-ipsec-nat-t-ike-0[01].txt and
* draft-ietf-ipsec-udp-encaps-(00/)01.txt, ignoring
* possible AH mode non-IKE marker+non-ESP marker
* from draft-ietf-ipsec-udp-encaps-00.txt.
*/
uint64_t marker;
if (payload <= sizeof(uint64_t) + sizeof(struct esp))
return (m); /* NB: no decap. */
bcopy(data + off, &marker, sizeof(uint64_t));
if (marker != 0) /* Non-IKE marker. */
return (m); /* NB: no decap. */
skip = sizeof(uint64_t) + sizeof(struct udphdr);
} else {
uint32_t spi;
if (payload <= sizeof(struct esp)) {
IPSECSTAT_INC(ips_in_inval);
m_freem(m);
return (NULL); /* Discard. */
}
bcopy(data + off, &spi, sizeof(uint32_t));
if (spi == 0) /* Non-ESP marker. */
return (m); /* NB: no decap. */
skip = sizeof(struct udphdr);
}
/*
* Setup a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
* the UDP ports. This is required if we want to select
* the right SPD for multiple hosts behind same NAT.
*
* NB: ports are maintained in network byte order everywhere
* in the NAT-T code.
*/
tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
2 * sizeof(uint16_t), M_NOWAIT);
if (tag == NULL) {
IPSECSTAT_INC(ips_in_nomem);
m_freem(m);
return (NULL); /* Discard. */
}
iphlen = off - sizeof(struct udphdr);
udphdr = (struct udphdr *)(data + iphlen);
((uint16_t *)(tag + 1))[0] = udphdr->uh_sport;
((uint16_t *)(tag + 1))[1] = udphdr->uh_dport;
m_tag_prepend(m, tag);
/*
* Remove the UDP header (and possibly the non ESP marker)
* IP header length is iphlen
* Before:
* <--- off --->
* +----+------+-----+
* | IP | UDP | ESP |
* +----+------+-----+
* <-skip->
* After:
* +----+-----+
* | IP | ESP |
* +----+-----+
* <-skip->
*/
ovbcopy(data, data + skip, iphlen);
m_adj(m, skip);
ip = mtod(m, struct ip *);
ip->ip_len = htons(ntohs(ip->ip_len) - skip);
ip->ip_p = IPPROTO_ESP;
/*
* We cannot yet update the cksums so clear any
* h/w cksum flags as they are no longer valid.
*/
if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
(void) ipsec4_common_input(m, iphlen, ip->ip_p);
return (NULL); /* NB: consumed, bypass processing. */
}
void
ipcomp4_input(struct mbuf *m, int off)
{
ipsec4_common_input(m, off, IPPROTO_IPCOMP);
}
void
esp4_input(struct mbuf *m, int off)
{
ipsec4_common_input(m, off, IPPROTO_ESP);
}
void
ah4_input(struct mbuf *m, int off)
{
ipsec4_common_input(m, off, IPPROTO_AH);
}
