/* ip_output.c 6.7 85/03/18 */
#include "../net/route.h"
ip_output(m
, opt
, ro
, flags
)
register struct ip
*ip
= mtod(m
, struct ip
*);
register struct ifnet
*ifp
;
int len
, hlen
= sizeof (struct ip
), off
, error
= 0;
(void) m_free(opt
); /* XXX */
if ((flags
& IP_FORWARDING
) == 0) {
ip
->ip_id
= htons(ip_id
++);
bzero((caddr_t
)ro
, sizeof (*ro
));
dst
= (struct sockaddr_in
*)&ro
->ro_dst
;
dst
->sin_family
= AF_INET
;
dst
->sin_addr
= ip
->ip_dst
;
* If routing to interface only,
* short circuit routing lookup.
if (flags
& IP_ROUTETOIF
) {
ia
= in_iaonnetof(in_netof(ip
->ip_dst
));
} else if ((ro
->ro_rt
->rt_flags
& RTF_UP
) == 0) {
* The old route has gone away; try for a new one.
if (ro
->ro_rt
== 0 || (ifp
= ro
->ro_rt
->rt_ifp
) == 0) {
if (ro
->ro_rt
->rt_flags
& (RTF_GATEWAY
|RTF_HOST
))
dst
= (struct sockaddr_in
*)&ro
->ro_rt
->rt_gateway
;
* Look for broadcast address and
* and verify user is allowed to send
if (in_broadcast(dst
->sin_addr
)) {
if ((ifp
->if_flags
& IFF_BROADCAST
) == 0) {
if ((flags
& IP_ALLOWBROADCAST
) == 0) {
/* don't allow broadcast messages to be fragmented */
if (ip
->ip_len
> ifp
->if_mtu
) {
* If small enough for interface, can just send directly.
if (ip
->ip_len
<= ifp
->if_mtu
) {
ip
->ip_len
= htons((u_short
)ip
->ip_len
);
ip
->ip_off
= htons((u_short
)ip
->ip_off
);
ip
->ip_sum
= in_cksum(m
, hlen
);
error
= (*ifp
->if_output
)(ifp
, m
, (struct sockaddr
*)dst
);
* Too large for interface; fragment if possible.
* Must be able to put at least 8 bytes per fragment.
if (ip
->ip_off
& IP_DF
) {
len
= (ifp
->if_mtu
- hlen
) &~ 7;
* Discard IP header from logical mbuf for m_copy's sake.
* Loop through length of segment, make a copy of each
m
->m_len
-= sizeof (struct ip
);
m
->m_off
+= sizeof (struct ip
);
for (off
= 0; off
< ip
->ip_len
-hlen
; off
+= len
) {
struct mbuf
*mh
= m_get(M_DONTWAIT
, MT_HEADER
);
mh
->m_off
= MMAXOFF
- hlen
;
mhip
= mtod(mh
, struct ip
*);
if (hlen
> sizeof (struct ip
)) {
int olen
= ip_optcopy(ip
, mhip
, off
);
mh
->m_len
= sizeof (struct ip
) + olen
;
mh
->m_len
= sizeof (struct ip
);
if (off
+ len
>= ip
->ip_len
-hlen
)
len
= mhip
->ip_len
= ip
->ip_len
- hlen
- off
;
mhip
->ip_len
+= sizeof (struct ip
);
mhip
->ip_len
= htons((u_short
)mhip
->ip_len
);
mh
->m_next
= m_copy(m
, off
, len
);
error
= ENOBUFS
; /* ??? */
mhip
->ip_off
= htons((u_short
)mhip
->ip_off
);
mhip
->ip_sum
= in_cksum(mh
, hlen
);
if (error
= (*ifp
->if_output
)(ifp
, mh
, (struct sockaddr
*)dst
))
if (ro
== &iproute
&& (flags
& IP_ROUTETOIF
) == 0 && ro
->ro_rt
)
* Copy options from ip to jp.
* If off is 0 all options are copied
* otherwise copy selectively.
register u_char
*cp
, *dp
;
cnt
= (ip
->ip_hl
<< 2) - sizeof (struct ip
);
for (; cnt
> 0; cnt
-= optlen
, cp
+= optlen
) {
if (optlen
> cnt
) /* XXX */
if (off
== 0 || IPOPT_COPIED(opt
)) {
bcopy((caddr_t
)cp
, (caddr_t
)dp
, (unsigned)optlen
);
for (optlen
= dp
- (u_char
*)(jp
+1); optlen
& 0x3; optlen
++)