#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <kern/queue.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <net/net_osdep.h>
#define IN6_IFSTAT_STRICT
static void frag6_enq __P((struct ip6asfrag *, struct ip6asfrag *));
static void frag6_deq __P((struct ip6asfrag *));
static void frag6_insque __P((struct ip6q *, struct ip6q *));
static void frag6_remque __P((struct ip6q *));
static void frag6_freef __P((struct ip6q *));
int frag6_doing_reass;
u_int frag6_nfragpackets;
struct ip6q ip6q;
#ifndef __APPLE__
MALLOC_DEFINE(M_FTABLE, "fragment", "fragment reassembly header");
#endif
void
frag6_init()
{
struct timeval tv;
ip6_maxfragpackets = nmbclusters / 4;
microtime(&tv);
ip6_id = random() ^ tv.tv_usec;
ip6q.ip6q_next = ip6q.ip6q_prev = &ip6q;
}
int
frag6_input(mp, offp, proto)
struct mbuf **mp;
int *offp, proto;
{
struct mbuf *m = *mp, *t;
struct ip6_hdr *ip6;
struct ip6_frag *ip6f;
struct ip6q *q6;
struct ip6asfrag *af6, *ip6af, *af6dwn;
int offset = *offp, nxt, i, next;
int first_frag = 0;
int fragoff, frgpartlen;
struct ifnet *dstifp;
#ifdef IN6_IFSTAT_STRICT
static struct route_in6 ro;
struct sockaddr_in6 *dst;
#endif
ip6 = mtod(m, struct ip6_hdr *);
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, offset, sizeof(struct ip6_frag), IPPROTO_DONE);
ip6f = (struct ip6_frag *)((caddr_t)ip6 + offset);
#else
IP6_EXTHDR_GET(ip6f, struct ip6_frag *, m, offset, sizeof(*ip6f));
if (ip6f == NULL)
return IPPROTO_DONE;
#endif
dstifp = NULL;
#ifdef IN6_IFSTAT_STRICT
dst = (struct sockaddr_in6 *)&ro.ro_dst;
if (ro.ro_rt
&& ((ro.ro_rt->rt_flags & RTF_UP) == 0
|| !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_dst))) {
rtfree(ro.ro_rt);
ro.ro_rt = (struct rtentry *)0;
}
if (ro.ro_rt == NULL) {
bzero(dst, sizeof(*dst));
dst->sin6_family = AF_INET6;
dst->sin6_len = sizeof(struct sockaddr_in6);
dst->sin6_addr = ip6->ip6_dst;
}
rtalloc((struct route *)&ro);
if (ro.ro_rt != NULL && ro.ro_rt->rt_ifa != NULL)
dstifp = ((struct in6_ifaddr *)ro.ro_rt->rt_ifa)->ia_ifp;
#else
if ((m->m_flags & M_PKTHDR) != 0)
dstifp = m->m_pkthdr.rcvif;
#endif
if (ip6->ip6_plen == 0) {
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offset);
in6_ifstat_inc(dstifp, ifs6_reass_fail);
return IPPROTO_DONE;
}
if ((ip6f->ip6f_offlg & IP6F_MORE_FRAG) &&
(((ntohs(ip6->ip6_plen) - offset) & 0x7) != 0)) {
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
offsetof(struct ip6_hdr, ip6_plen));
in6_ifstat_inc(dstifp, ifs6_reass_fail);
return IPPROTO_DONE;
}
ip6stat.ip6s_fragments++;
in6_ifstat_inc(dstifp, ifs6_reass_reqd);
offset += sizeof(struct ip6_frag);
frag6_doing_reass = 1;
for (q6 = ip6q.ip6q_next; q6 != &ip6q; q6 = q6->ip6q_next)
if (ip6f->ip6f_ident == q6->ip6q_ident &&
IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &q6->ip6q_src) &&
IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &q6->ip6q_dst))
break;
if (q6 == &ip6q) {
first_frag = 1;
if (ip6_maxfragpackets < 0)
;
else if (frag6_nfragpackets >= (u_int)ip6_maxfragpackets)
goto dropfrag;
frag6_nfragpackets++;
q6 = (struct ip6q *)_MALLOC(sizeof(struct ip6q), M_FTABLE,
M_DONTWAIT);
if (q6 == NULL)
goto dropfrag;
bzero(q6, sizeof(*q6));
frag6_insque(q6, &ip6q);
q6->ip6q_down = q6->ip6q_up = (struct ip6asfrag *)q6;
#ifdef notyet
q6->ip6q_nxtp = (u_char *)nxtp;
#endif
q6->ip6q_ident = ip6f->ip6f_ident;
q6->ip6q_arrive = 0;
q6->ip6q_ttl = IPV6_FRAGTTL;
q6->ip6q_src = ip6->ip6_src;
q6->ip6q_dst = ip6->ip6_dst;
q6->ip6q_unfrglen = -1;
}
fragoff = ntohs(ip6f->ip6f_offlg & IP6F_OFF_MASK);
if (fragoff == 0) {
q6->ip6q_unfrglen = offset - sizeof(struct ip6_hdr)
- sizeof(struct ip6_frag);
q6->ip6q_nxt = ip6f->ip6f_nxt;
}
frgpartlen = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen) - offset;
if (q6->ip6q_unfrglen >= 0) {
if (q6->ip6q_unfrglen + fragoff + frgpartlen > IPV6_MAXPACKET) {
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
offset - sizeof(struct ip6_frag) +
offsetof(struct ip6_frag, ip6f_offlg));
frag6_doing_reass = 0;
return(IPPROTO_DONE);
}
}
else if (fragoff + frgpartlen > IPV6_MAXPACKET) {
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
offset - sizeof(struct ip6_frag) +
offsetof(struct ip6_frag, ip6f_offlg));
frag6_doing_reass = 0;
return(IPPROTO_DONE);
}
if (fragoff == 0) {
for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
af6 = af6dwn) {
af6dwn = af6->ip6af_down;
if (q6->ip6q_unfrglen + af6->ip6af_off + af6->ip6af_frglen >
IPV6_MAXPACKET) {
struct mbuf *merr = IP6_REASS_MBUF(af6);
struct ip6_hdr *ip6err;
int erroff = af6->ip6af_offset;
frag6_deq(af6);
FREE(af6, M_FTABLE);
ip6err = mtod(merr, struct ip6_hdr *);
ip6err->ip6_src = q6->ip6q_src;
ip6err->ip6_dst = q6->ip6q_dst;
icmp6_error(merr, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff - sizeof(struct ip6_frag) +
offsetof(struct ip6_frag, ip6f_offlg));
}
}
}
ip6af = (struct ip6asfrag *)_MALLOC(sizeof(struct ip6asfrag), M_FTABLE,
M_DONTWAIT);
if (ip6af == NULL)
goto dropfrag;
bzero(ip6af, sizeof(*ip6af));
ip6af->ip6af_head = ip6->ip6_flow;
ip6af->ip6af_len = ip6->ip6_plen;
ip6af->ip6af_nxt = ip6->ip6_nxt;
ip6af->ip6af_hlim = ip6->ip6_hlim;
ip6af->ip6af_mff = ip6f->ip6f_offlg & IP6F_MORE_FRAG;
ip6af->ip6af_off = fragoff;
ip6af->ip6af_frglen = frgpartlen;
ip6af->ip6af_offset = offset;
IP6_REASS_MBUF(ip6af) = m;
if (first_frag) {
af6 = (struct ip6asfrag *)q6;
goto insert;
}
for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
af6 = af6->ip6af_down)
if (af6->ip6af_off > ip6af->ip6af_off)
break;
#if 0
if (af6->ip6af_up != (struct ip6asfrag *)q6) {
i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen
- ip6af->ip6af_off;
if (i > 0) {
if (i >= ip6af->ip6af_frglen)
goto dropfrag;
m_adj(IP6_REASS_MBUF(ip6af), i);
ip6af->ip6af_off += i;
ip6af->ip6af_frglen -= i;
}
}
while (af6 != (struct ip6asfrag *)q6 &&
ip6af->ip6af_off + ip6af->ip6af_frglen > af6->ip6af_off) {
i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off;
if (i < af6->ip6af_frglen) {
af6->ip6af_frglen -= i;
af6->ip6af_off += i;
m_adj(IP6_REASS_MBUF(af6), i);
break;
}
af6 = af6->ip6af_down;
m_freem(IP6_REASS_MBUF(af6->ip6af_up));
frag6_deq(af6->ip6af_up);
}
#else
if (af6->ip6af_up != (struct ip6asfrag *)q6) {
i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen
- ip6af->ip6af_off;
if (i > 0) {
#if 0
log(LOG_ERR, "%d bytes of a fragment from %s "
"overlaps the previous fragment\n",
i, ip6_sprintf(&q6->ip6q_src));
#endif
FREE(ip6af, M_FTABLE);
goto dropfrag;
}
}
if (af6 != (struct ip6asfrag *)q6) {
i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off;
if (i > 0) {
#if 0
log(LOG_ERR, "%d bytes of a fragment from %s "
"overlaps the succeeding fragment",
i, ip6_sprintf(&q6->ip6q_src));
#endif
FREE(ip6af, M_FTABLE);
goto dropfrag;
}
}
#endif
insert:
frag6_enq(ip6af, af6->ip6af_up);
#if 0
if (q6 != ip6q.ip6q_next) {
frag6_remque(q6);
frag6_insque(q6, &ip6q);
}
#endif
next = 0;
for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
af6 = af6->ip6af_down) {
if (af6->ip6af_off != next) {
frag6_doing_reass = 0;
return IPPROTO_DONE;
}
next += af6->ip6af_frglen;
}
if (af6->ip6af_up->ip6af_mff) {
frag6_doing_reass = 0;
return IPPROTO_DONE;
}
ip6af = q6->ip6q_down;
t = m = IP6_REASS_MBUF(ip6af);
af6 = ip6af->ip6af_down;
frag6_deq(ip6af);
while (af6 != (struct ip6asfrag *)q6) {
af6dwn = af6->ip6af_down;
frag6_deq(af6);
while (t->m_next)
t = t->m_next;
t->m_next = IP6_REASS_MBUF(af6);
m_adj(t->m_next, af6->ip6af_offset);
FREE(af6, M_FTABLE);
af6 = af6dwn;
}
offset = ip6af->ip6af_offset - sizeof(struct ip6_frag);
FREE(ip6af, M_FTABLE);
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_plen = htons((u_short)next + offset - sizeof(struct ip6_hdr));
ip6->ip6_src = q6->ip6q_src;
ip6->ip6_dst = q6->ip6q_dst;
nxt = q6->ip6q_nxt;
#if notyet
*q6->ip6q_nxtp = (u_char)(nxt & 0xff);
#endif
if (offset < m->m_len) {
ovbcopy((caddr_t)ip6, (caddr_t)ip6 + sizeof(struct ip6_frag),
offset);
m->m_data += sizeof(struct ip6_frag);
m->m_len -= sizeof(struct ip6_frag);
} else {
if ((t = m_split(m, offset, M_DONTWAIT)) == NULL) {
frag6_remque(q6);
FREE(q6, M_FTABLE);
frag6_nfragpackets--;
goto dropfrag;
}
m_adj(t, sizeof(struct ip6_frag));
m_cat(m, t);
}
{
char *prvnxtp = ip6_get_prevhdr(m, offset);
*prvnxtp = nxt;
}
frag6_remque(q6);
FREE(q6, M_FTABLE);
frag6_nfragpackets--;
if (m->m_flags & M_PKTHDR) {
int plen = 0;
for (t = m; t; t = t->m_next)
plen += t->m_len;
m->m_pkthdr.len = plen;
}
ip6stat.ip6s_reassembled++;
in6_ifstat_inc(dstifp, ifs6_reass_ok);
*mp = m;
*offp = offset;
frag6_doing_reass = 0;
return nxt;
dropfrag:
in6_ifstat_inc(dstifp, ifs6_reass_fail);
ip6stat.ip6s_fragdropped++;
m_freem(m);
frag6_doing_reass = 0;
return IPPROTO_DONE;
}
void
frag6_freef(q6)
struct ip6q *q6;
{
struct ip6asfrag *af6, *down6;
for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
af6 = down6) {
struct mbuf *m = IP6_REASS_MBUF(af6);
down6 = af6->ip6af_down;
frag6_deq(af6);
if (af6->ip6af_off == 0) {
struct ip6_hdr *ip6;
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_src = q6->ip6q_src;
ip6->ip6_dst = q6->ip6q_dst;
icmp6_error(m, ICMP6_TIME_EXCEEDED,
ICMP6_TIME_EXCEED_REASSEMBLY, 0);
} else
m_freem(m);
FREE(af6, M_FTABLE);
}
frag6_remque(q6);
FREE(q6, M_FTABLE);
frag6_nfragpackets--;
}
void
frag6_enq(af6, up6)
struct ip6asfrag *af6, *up6;
{
af6->ip6af_up = up6;
af6->ip6af_down = up6->ip6af_down;
up6->ip6af_down->ip6af_up = af6;
up6->ip6af_down = af6;
}
void
frag6_deq(af6)
struct ip6asfrag *af6;
{
af6->ip6af_up->ip6af_down = af6->ip6af_down;
af6->ip6af_down->ip6af_up = af6->ip6af_up;
}
void
frag6_insque(new, old)
struct ip6q *new, *old;
{
new->ip6q_prev = old;
new->ip6q_next = old->ip6q_next;
old->ip6q_next->ip6q_prev= new;
old->ip6q_next = new;
}
void
frag6_remque(p6)
struct ip6q *p6;
{
p6->ip6q_prev->ip6q_next = p6->ip6q_next;
p6->ip6q_next->ip6q_prev = p6->ip6q_prev;
}
void
frag6_slowtimo()
{
struct ip6q *q6;
int s = splnet();
frag6_doing_reass = 1;
q6 = ip6q.ip6q_next;
if (q6)
while (q6 != &ip6q) {
--q6->ip6q_ttl;
q6 = q6->ip6q_next;
if (q6->ip6q_prev->ip6q_ttl == 0) {
ip6stat.ip6s_fragtimeout++;
frag6_freef(q6->ip6q_prev);
}
}
while (frag6_nfragpackets > (u_int)ip6_maxfragpackets &&
ip6q.ip6q_prev) {
ip6stat.ip6s_fragoverflow++;
frag6_freef(ip6q.ip6q_prev);
}
frag6_doing_reass = 0;
#if 0
if (ip6_forward_rt.ro_rt) {
rtfree(ip6_forward_rt.ro_rt);
ip6_forward_rt.ro_rt = 0;
}
if (ipsrcchk_rt.ro_rt) {
rtfree(ipsrcchk_rt.ro_rt);
ipsrcchk_rt.ro_rt = 0;
}
#endif
splx(s);
}
void
frag6_drain()
{
if (frag6_doing_reass)
return;
while (ip6q.ip6q_next != &ip6q) {
ip6stat.ip6s_fragdropped++;
frag6_freef(ip6q.ip6q_next);
}
}