struct dsr_opt *dsr_opt_find_opt(struct dsr_pkt *dp, int type)
{
int dsr_len, l;
struct dsr_opt *dopt;
dsr_len = dsr_pkt_opts_len(dp);
l = DSR_OPT_HDR_LEN;
dopt = DSR_GET_OPT(dp->dh.opth);
while (l < dsr_len && (dsr_len - l) > 2) {
if (type == dopt->type)
return dopt;
l += dopt->length + 2;
dopt = DSR_GET_NEXT_OPT(dopt);
}
return NULL;
}
struct dsr_ack_req_opt *NSCLASS
dsr_ack_req_opt_add(struct dsr_pkt *dp, unsigned short id)
{
char *buf = NULL;
int prot = 0, tot_len = 0, ttl = IPDEFTTL;
if (!dp)
return NULL;
/* If we are forwarding a packet and there is already an ACK REQ option,
* we just overwrite the old one. */
if (dp->ack_req_opt) {
buf = (char *)dp->ack_req_opt;
goto end;
}
#ifdef NS2
if (dp->p) {
hdr_cmn *cmh = HDR_CMN(dp->p);
prot = cmh->ptype();
} else
prot = DSR_NO_NEXT_HDR_TYPE;
ttl = dp->nh.iph->ttl();
#else
if (dp->nh.raw) {
tot_len = ntohs(dp->nh.iph->tot_len);
prot = dp->nh.iph->protocol;
ttl = dp->nh.iph->ttl;
}
#endif
if (!dsr_pkt_opts_len(dp)) {
buf =
dsr_pkt_alloc_opts(dp,
DSR_OPT_HDR_LEN + DSR_ACK_REQ_HDR_LEN);
LOG_DBG("Allocating options for ACK REQ\n");
if (!buf)
return NULL;
dsr_build_ip(dp, dp->src, dp->dst, IP_HDR_LEN,
tot_len + DSR_OPT_HDR_LEN + DSR_ACK_REQ_HDR_LEN,
IPPROTO_DSR, ttl);
dp->dh.opth =
dsr_opt_hdr_add(buf, DSR_OPT_HDR_LEN + DSR_ACK_REQ_HDR_LEN,
prot);
if (!dp->dh.opth) {
return NULL;
}
buf += DSR_OPT_HDR_LEN;
} else {
buf = dsr_pkt_alloc_opts_expand(dp, DSR_ACK_REQ_HDR_LEN);
LOG_DBG("Expanding options for ACK REQ p_len=%d\n",
ntohs(dp->dh.opth->p_len));
if (!buf)
return NULL;
dsr_build_ip(dp, dp->src, dp->dst, IP_HDR_LEN,
tot_len + DSR_ACK_REQ_HDR_LEN, IPPROTO_DSR, ttl);
dp->dh.opth =
dsr_opt_hdr_add(dp->dh.raw,
DSR_OPT_HDR_LEN +
ntohs(dp->dh.opth->p_len) +
DSR_ACK_REQ_HDR_LEN, dp->dh.opth->nh);
}
LOG_DBG("Added ACK REQ option id=%u\n", id, ntohs(dp->dh.opth->p_len));
end:
return dsr_ack_req_opt_create(buf, DSR_ACK_REQ_HDR_LEN, id);
}
int dsr_opt_parse(struct dsr_pkt *dp)
{
int dsr_len, l, n = 0;
struct dsr_opt *dopt;
if (!dp)
return -1;
dsr_len = dsr_pkt_opts_len(dp);
l = DSR_OPT_HDR_LEN;
dopt = DSR_GET_OPT(dp->dh.opth); //skip dsr option header
dp->num_rrep_opts = dp->num_rerr_opts = dp->num_rreq_opts = dp->num_ack_opts = 0;
dp->srt_opt = NULL;
dp->ack_req_opt = NULL;
while (l < dsr_len && (dsr_len - l) > 2) {
switch (dopt->type) {
case DSR_OPT_PADN:
break;
case DSR_OPT_RREQ:
if (dp->num_rreq_opts == 0)
dp->rreq_opt = (struct dsr_rreq_opt *)dopt;
#ifndef NS2
else
DEBUG("ERROR: More than one RREQ option!!\n");
#endif
break;
case DSR_OPT_RREP:
if (dp->num_rrep_opts < MAX_RREP_OPTS)
dp->rrep_opt[dp->num_rrep_opts++] = (struct dsr_rrep_opt *)dopt;
#ifndef NS2
else
DEBUG("Maximum RREP opts in one packet reached\n");
#endif
break;
case DSR_OPT_RERR:
if (dp->num_rerr_opts < MAX_RERR_OPTS)
dp->rerr_opt[dp->num_rerr_opts++] = (struct dsr_rerr_opt *)dopt;
#ifndef NS2
else
DEBUG("Maximum RERR opts in one packet reached\n");
#endif
break;
case DSR_OPT_PREV_HOP:
break;
case DSR_OPT_ACK:
if (dp->num_ack_opts < MAX_ACK_OPTS)
dp->ack_opt[dp->num_ack_opts++] = (struct dsr_ack_opt *)dopt;
#ifndef NS2
else
DEBUG("Maximum ACK opts in one packet reached\n");
#endif
break;
case DSR_OPT_SRT:
if (!dp->srt_opt)
dp->srt_opt = (struct dsr_srt_opt *)dopt;
#ifndef NS2
else
DEBUG("More than one source route in packet\n");
#endif
break;
case DSR_OPT_TIMEOUT:
break;
case DSR_OPT_FLOWID:
break;
case DSR_OPT_ACK_REQ:
if (!dp->ack_req_opt)
dp->ack_req_opt = (struct dsr_ack_req_opt *)dopt;
#ifndef NS2
else
DEBUG("More than one ACK REQ in packet\n");
#endif
break;
case DSR_OPT_PAD1:
l++;
dopt++;
continue;
#ifndef NS2
default:
DEBUG("Unknown DSR option type=%d\n", dopt->type);
#endif
}
l += dopt->length + 2;
dopt = DSR_GET_NEXT_OPT(dopt);
n++;
}
return n;
}
int NSCLASS dsr_opt_recv(struct dsr_pkt *dp)
{
int dsr_len, l;
int action = 0;
struct dsr_opt *dopt;
struct in_addr myaddr;
if (!dp)
return DSR_PKT_ERROR;
myaddr = my_addr();
/* Packet for us ? */
if (dp->dst.s_addr == myaddr.s_addr && dp->payload_len != 0)
action |= DSR_PKT_DELIVER;
dsr_len = dsr_pkt_opts_len(dp);
l = DSR_OPT_HDR_LEN;
dopt = DSR_GET_OPT(dp->dh.opth);
//DEBUG("Parsing DSR packet l=%d dsr_len=%d\n", l, dsr_len);
while (l < dsr_len && (dsr_len - l) > 2) {
//DEBUG("dsr_len=%d l=%d\n", dsr_len, l);
switch (dopt->type) {
case DSR_OPT_PADN:
break;
case DSR_OPT_RREQ:
if (dp->flags & PKT_PROMISC_RECV)
break;
action |= dsr_rreq_opt_recv(dp, (struct dsr_rreq_opt *)dopt);
break;
case DSR_OPT_RREP:
/* We should probably allow promisuously
* receiving RREPs */
if (dp->flags & PKT_PROMISC_RECV)
break;
action |= dsr_rrep_opt_recv(dp, (struct dsr_rrep_opt *)dopt);
break;
case DSR_OPT_RERR:
if (dp->flags & PKT_PROMISC_RECV)
break;
if (dp->num_rerr_opts < MAX_RERR_OPTS) {
action |=
dsr_rerr_opt_recv(dp, (struct dsr_rerr_opt *)dopt);
}
break;
case DSR_OPT_PREV_HOP:
break;
case DSR_OPT_ACK:
if (dp->flags & PKT_PROMISC_RECV)
break;
if (dp->num_ack_opts < MAX_ACK_OPTS) {
dp->ack_opt[dp->num_ack_opts++] =
(struct dsr_ack_opt *)dopt;
action |=
dsr_ack_opt_recv((struct dsr_ack_opt *)
dopt);
}
break;
case DSR_OPT_SRT:
action |= dsr_srt_opt_recv(dp, (struct dsr_srt_opt *)dopt);
break;
case DSR_OPT_TIMEOUT:
break;
case DSR_OPT_FLOWID:
break;
case DSR_OPT_ACK_REQ:
action |=
dsr_ack_req_opt_recv(dp, (struct dsr_ack_req_opt *)
dopt);
break;
case DSR_OPT_PAD1:
l++;
dopt++;
continue;
default:
DEBUG("Unknown DSR option type=%d\n", dopt->type);
}
l += dopt->length + 2;
dopt = DSR_GET_NEXT_OPT(dopt);
}
return action;
}
struct sk_buff *dsr_skb_create(struct dsr_pkt *dp, struct net_device *dev)
{
struct sk_buff *skb;
char *buf;
int ip_len;
int tot_len;
int dsr_opts_len = dsr_pkt_opts_len(dp);
ip_len = dp->nh.iph->ihl << 2;
tot_len = ip_len + dsr_opts_len + dp->payload_len;
DEBUG("ip_len=%d dsr_opts_len=%d payload_len=%d tot_len=%d\n",
ip_len, dsr_opts_len, dp->payload_len, tot_len);
#ifdef KERNEL26
skb = alloc_skb(tot_len + LL_RESERVED_SPACE(dev), GFP_ATOMIC);
#else
skb = alloc_skb(dev->hard_header_len + 15 + tot_len, GFP_ATOMIC);
#endif
if (!skb) {
DEBUG("alloc_skb failed\n");
return NULL;
}
SKB_SET_MAC_HDR(skb, 0);
/* We align to 16 bytes, for ethernet: 2 bytes + 14 bytes
* header. This will move the skb->data pointer forward. */
#ifdef KERNEL26
skb_reserve(skb, LL_RESERVED_SPACE(dev));
#else
skb_reserve(skb, (dev->hard_header_len + 15) & ~15);
#endif
SKB_SET_NETWORK_HDR(skb, 0);
skb->dev = dev;
skb->protocol = htons(ETH_P_IP);
/* Copy in all the headers in the right order */
buf = skb_put(skb, tot_len);
memcpy(buf, dp->nh.raw, ip_len);
/* For some reason the checksum has to be recalculated here, at least
* when there is a record route IP option */
ip_send_check((struct iphdr *)buf);
buf += ip_len;
/* Add DSR header if it exists */
if (dsr_opts_len) {
memcpy(buf, dp->dh.raw, dsr_opts_len);
buf += dsr_opts_len;
}
/* Add payload */
if (dp->payload_len && dp->payload)
memcpy(buf, dp->payload, dp->payload_len);
return skb;
}