/*
* m_pullup2() works like m_pullup, save that len can be <= MCLBYTES.
* m_pullup2() only works on values of len such that MHLEN < len <= MCLBYTES,
* it calls m_pullup() for values <= MHLEN. It also only coagulates the
* reqested number of bytes. (For those of us who expect unwieldly option
* headers.
*
* KEBE SAYS: Remember that dtom() calls with data in clusters does not work!
*/
struct mbuf *
m_pullup2(struct mbuf *n, int len)
{
struct mbuf *m;
int count;
if (len <= MHLEN)
return m_pullup(n, len);
if ((n->m_flags & M_EXT) != 0 &&
n->m_data + len < &n->m_data[MCLBYTES] && n->m_next) {
if (n->m_len >= len)
return (n);
m = n;
n = n->m_next;
len -= m->m_len;
} else {
if (len > MCLBYTES)
goto bad;
MGET(m, M_DONTWAIT, n->m_type);
if (m == NULL)
goto bad;
MCLGET(m, M_DONTWAIT);
if ((m->m_flags & M_EXT) == 0)
goto bad;
m->m_len = 0;
if (n->m_flags & M_PKTHDR) {
/* Too many adverse side effects. */
/* M_MOVE_PKTHDR(m, n); */
m->m_flags = (n->m_flags & M_COPYFLAGS) |
M_EXT | M_CLUSTER;
M_MOVE_HDR(m, n);
/* n->m_data is cool. */
}
}
do {
count = min(len, n->m_len);
bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
(unsigned)count);
len -= count;
m->m_len += count;
n->m_len -= count;
if (n->m_len)
n->m_data += count;
else
n = m_free(n);
} while (len > 0 && n);
if (len > 0) {
(void)m_free(m);
goto bad;
}
m->m_next = n;
return (m);
bad:
m_freem(n);
MPFail++;
return (NULL);
}
int
gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
struct rtentry *rt)
{
int error = 0;
struct gre_softc *sc = (struct gre_softc *) (ifp->if_softc);
struct greip *gh = NULL;
struct ip *inp = NULL;
u_int8_t ip_tos = 0;
u_int16_t etype = 0;
struct mobile_h mob_h;
struct m_tag *mtag;
if ((ifp->if_flags & IFF_UP) == 0 ||
sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
m_freem(m);
error = ENETDOWN;
goto end;
}
#ifdef DIAGNOSTIC
if (ifp->if_rdomain != rtable_l2(m->m_pkthdr.rdomain)) {
printf("%s: trying to send packet on wrong domain. "
"if %d vs. mbuf %d, AF %d\n", ifp->if_xname,
ifp->if_rdomain, rtable_l2(m->m_pkthdr.rdomain),
dst->sa_family);
}
#endif
/* Try to limit infinite recursion through misconfiguration. */
for (mtag = m_tag_find(m, PACKET_TAG_GRE, NULL); mtag;
mtag = m_tag_find(m, PACKET_TAG_GRE, mtag)) {
if (!bcmp((caddr_t)(mtag + 1), &ifp, sizeof(struct ifnet *))) {
IF_DROP(&ifp->if_snd);
m_freem(m);
error = EIO;
goto end;
}
}
mtag = m_tag_get(PACKET_TAG_GRE, sizeof(struct ifnet *), M_NOWAIT);
if (mtag == NULL) {
IF_DROP(&ifp->if_snd);
m_freem(m);
error = ENOBUFS;
goto end;
}
bcopy(&ifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *));
m_tag_prepend(m, mtag);
m->m_flags &= ~(M_BCAST|M_MCAST);
#if NBPFILTER > 0
if (ifp->if_bpf)
bpf_mtap_af(ifp->if_bpf, dst->sa_family, m, BPF_DIRECTION_OUT);
#endif
if (sc->g_proto == IPPROTO_MOBILE) {
if (ip_mobile_allow == 0) {
IF_DROP(&ifp->if_snd);
m_freem(m);
error = EACCES;
goto end;
}
if (dst->sa_family == AF_INET) {
struct mbuf *m0;
int msiz;
/*
* Make sure the complete IP header (with options)
* is in the first mbuf.
*/
if (m->m_len < sizeof(struct ip)) {
m = m_pullup(m, sizeof(struct ip));
if (m == NULL) {
IF_DROP(&ifp->if_snd);
error = ENOBUFS;
goto end;
} else
inp = mtod(m, struct ip *);
if (m->m_len < inp->ip_hl << 2) {
m = m_pullup(m, inp->ip_hl << 2);
if (m == NULL) {
IF_DROP(&ifp->if_snd);
error = ENOBUFS;
goto end;
}
}
}
inp = mtod(m, struct ip *);
bzero(&mob_h, MOB_H_SIZ_L);
mob_h.proto = (inp->ip_p) << 8;
mob_h.odst = inp->ip_dst.s_addr;
inp->ip_dst.s_addr = sc->g_dst.s_addr;
/*
* If the packet comes from our host, we only change
* the destination address in the IP header.
* Otherwise we need to save and change the source.
*/
if (inp->ip_src.s_addr == sc->g_src.s_addr) {
msiz = MOB_H_SIZ_S;
} else {
mob_h.proto |= MOB_H_SBIT;
mob_h.osrc = inp->ip_src.s_addr;
inp->ip_src.s_addr = sc->g_src.s_addr;
msiz = MOB_H_SIZ_L;
}
HTONS(mob_h.proto);
mob_h.hcrc = gre_in_cksum((u_int16_t *) &mob_h, msiz);
/* Squeeze in the mobility header */
if ((m->m_data - msiz) < m->m_pktdat) {
/* Need new mbuf */
MGETHDR(m0, M_DONTWAIT, MT_HEADER);
if (m0 == NULL) {
IF_DROP(&ifp->if_snd);
m_freem(m);
error = ENOBUFS;
goto end;
}
M_MOVE_HDR(m0, m);
m0->m_len = msiz + (inp->ip_hl << 2);
m0->m_data += max_linkhdr;
m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
m->m_data += inp->ip_hl << 2;
m->m_len -= inp->ip_hl << 2;
bcopy((caddr_t) inp, mtod(m0, caddr_t),
sizeof(struct ip));
m0->m_next = m;
m = m0;
} else { /* we have some space left in the old one */
m->m_data -= msiz;
m->m_len += msiz;
m->m_pkthdr.len += msiz;
bcopy(inp, mtod(m, caddr_t),
inp->ip_hl << 2);
}
/* Copy Mobility header */
inp = mtod(m, struct ip *);
bcopy(&mob_h, (caddr_t)(inp + 1), (unsigned) msiz);
inp->ip_len = htons(ntohs(inp->ip_len) + msiz);
} else { /* AF_INET */
