/*
* Broadcast a RARP request (i.e. who knows who I am)
*/
static ssize_t
rarpsend(struct iodesc *d, void *pkt, size_t len)
{
#ifdef RARP_DEBUG
if (debug)
printf("rarpsend: called\n");
#endif
return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP));
}
/*
* sends an IP packet, if it's alredy constructed
*/
static ssize_t
_sendip(struct iodesc * d, struct ip * ip, size_t len)
{
u_char *ea;
if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 ||
netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask)) {
ea = arpwhohas(d, ip->ip_dst);
} else {
ea = arpwhohas(d, gateip);
}
return sendether(d, ip, len, ea, ETHERTYPE_IP);
}
/*
* Convert an ARP request into a reply and send it.
* Notes: Re-uses buffer. Pad to length = 46.
*/
void
arp_reply(struct iodesc *d, void *pkt)
{
struct ether_arp *arp = pkt;
if (arp->arp_hrd != htons(ARPHRD_ETHER) ||
arp->arp_pro != htons(ETHERTYPE_IP) ||
arp->arp_hln != sizeof(arp->arp_sha) ||
arp->arp_pln != sizeof(arp->arp_spa) )
{
#ifdef ARP_DEBUG
if (debug)
printf("arp_reply: bad hrd/pro/hln/pln\n");
#endif
return;
}
if (arp->arp_op != htons(ARPOP_REQUEST)) {
#ifdef ARP_DEBUG
if (debug)
printf("arp_reply: not request!\n");
#endif
return;
}
/* If we are not the target, ignore the request. */
if (bcmp(arp->arp_tpa, &d->myip, sizeof(arp->arp_tpa)))
return;
#ifdef ARP_DEBUG
if (debug) {
printf("arp_reply: to %s\n", ether_sprintf(arp->arp_sha));
}
#endif
arp->arp_op = htons(ARPOP_REPLY);
/* source becomes target */
bcopy(arp->arp_sha, arp->arp_tha, sizeof(arp->arp_tha));
bcopy(arp->arp_spa, arp->arp_tpa, sizeof(arp->arp_tpa));
/* here becomes source */
bcopy(d->myea, arp->arp_sha, sizeof(arp->arp_sha));
bcopy(&d->myip, arp->arp_spa, sizeof(arp->arp_spa));
/*
* No need to get fancy here. If the send fails, the
* requestor will just ask again.
*/
(void) sendether(d, pkt, sizeof(*arp) + 18,
arp->arp_tha, ETHERTYPE_ARP);
}
/* Caller must leave room for ethernet, ip and udp headers in front!! */
ssize_t
sendudp(struct iodesc *d, void *pkt, size_t len)
{
ssize_t cc;
struct ip *ip;
struct udpiphdr *ui;
struct udphdr *uh;
u_char *ea;
struct ip tip;
#ifdef NET_DEBUG
if (debug) {
printf("sendudp: d=%x called.\n", (u_int)d);
if (d) {
printf("saddr: %s:%d",
inet_ntoa(d->myip), ntohs(d->myport));
printf(" daddr: %s:%d\n",
inet_ntoa(d->destip), ntohs(d->destport));
}
}
#endif
uh = (struct udphdr *)pkt - 1;
ip = (struct ip *)uh - 1;
len += sizeof(*ip) + sizeof(*uh);
bzero(ip, sizeof(*ip) + sizeof(*uh));
ip->ip_v = IPVERSION; /* half-char */
ip->ip_hl = sizeof(*ip) >> 2; /* half-char */
ip->ip_len = htons(len);
ip->ip_p = IPPROTO_UDP; /* char */
ip->ip_ttl = IP_TTL; /* char */
ip->ip_src = d->myip;
ip->ip_dst = d->destip;
ip->ip_sum = in_cksum(ip, sizeof(*ip)); /* short, but special */
uh->uh_sport = d->myport;
uh->uh_dport = d->destport;
uh->uh_ulen = htons(len - sizeof(*ip));
/* Calculate checksum (must save and restore ip header) */
tip = *ip;
ui = (struct udpiphdr *)ip;
bzero(ui->ui_x1, sizeof(ui->ui_x1));
ui->ui_len = uh->uh_ulen;
uh->uh_sum = in_cksum(ui, len);
*ip = tip;
if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 ||
netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask))
ea = arpwhohas(d, ip->ip_dst);
else
ea = arpwhohas(d, gateip);
cc = sendether(d, ip, len, ea, ETHERTYPE_IP);
if (cc < 0)
return (-1);
if ((size_t)cc != len)
panic("sendudp: bad write (%d != %d)", cc, len);
return (cc - (sizeof(*ip) + sizeof(*uh)));
}
