/* ip_output.c 1.37 82/10/13 */
#include "../h/socketvar.h"
#include "../netinet/in.h"
#include "../netinet/in_systm.h"
#include "../netinet/ip.h"
#include "../netinet/ip_var.h"
#include "../net/route.h"
ip_output(m
, opt
, ro
, allowbroadcast
)
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 */
ip
->ip_id
= htons(ip_id
++);
bzero((caddr_t
)ro
, sizeof (*ro
));
ro
->ro_dst
.sa_family
= AF_INET
;
((struct sockaddr_in
*)&ro
->ro_dst
)->sin_addr
= ip
->ip_dst
;
* If routing to interface only, short circuit routing lookup.
/* check ifp is AF_INET??? */
ifp
= if_ifonnetof(IN_NETOF(ip
->ip_dst
));
if (ro
->ro_rt
== 0 || (ifp
= ro
->ro_rt
->rt_ifp
) == 0)
if (ro
->ro_rt
->rt_flags
& RTF_GATEWAY
)
dst
= &ro
->ro_rt
->rt_gateway
;
* If source address not specified yet, use address
if (ip
->ip_src
.s_addr
== 0)
((struct sockaddr_in
*)&ifp
->if_addr
)->sin_addr
.s_addr
;
* Have interface for packet. Allow
* broadcasts only by authorized users.
if (!allowbroadcast
&& (ifp
->if_flags
& IFF_BROADCAST
)) {
sin
= (struct sockaddr_in
*)&ifp
->if_broadaddr
;
if (sin
->sin_addr
.s_addr
== ip
->ip_dst
.s_addr
) {
* 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
, 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
);
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
, dst
))
printf("no route to %x (from %x, len %d)\n",
ip
->ip_dst
.s_addr
, ip
->ip_src
.s_addr
, ip
->ip_len
);
if (ro
== &iproute
&& 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
++)