void
handle_ether(const u_char * pkt, int len, void *userdata)
{
struct ether_header *e = (struct ether_header *)pkt;
unsigned short etype;
if (len < ETHER_HDR_LEN)
return;
etype = nptohs(&e->ether_type);
if (callback_ether)
if (0 != callback_ether(pkt, len, userdata))
return;
pkt += ETHER_HDR_LEN;
len -= ETHER_HDR_LEN;
if (ETHERTYPE_8021Q == etype) {
unsigned short vlan = nptohs((unsigned short *) pkt);
if (callback_vlan)
if (0 != callback_vlan(vlan, userdata))
return;
etype = nptohs((unsigned short *)(pkt + 2));
pkt += 4;
len -= 4;
}
if (len < 0)
return;
/* fprintf(stderr, "Ethernet packet of len %d ethertype %#04x\n", len, etype); */
if (is_ethertype_ip(etype)) {
handle_ip((struct ip *)pkt, len, userdata);
}
}
void
handle_ppp(const u_char * pkt, int len, void *userdata)
{
char buf[PCAP_SNAPLEN];
unsigned short proto;
if (len < 2)
return NULL;
if (*pkt == PPP_ADDRESS_VAL && *(pkt + 1) == PPP_CONTROL_VAL) {
pkt += 2; /* ACFC not used */
len -= 2;
}
if (len < 2)
return NULL;
if (*pkt % 2) {
proto = *pkt; /* PFC is used */
pkt++;
len--;
} else {
proto = nptohs(pkt);
pkt += 2;
len -= 2;
}
if (is_ethertype_ip(proto))
handle_ip((struct ip *)pkt, len, userdata);
}
dns_message *
handle_ether(const u_char * pkt, int len)
{
char buf[PCAP_SNAPLEN];
struct ether_header *e = (void *) pkt;
unsigned short etype = ntohs(e->ether_type);
if (len < ETHER_HDR_LEN)
return NULL;
pkt += ETHER_HDR_LEN;
len -= ETHER_HDR_LEN;
if (ETHERTYPE_8021Q == etype) {
if (!match_vlan(pkt))
return NULL;
etype = ntohs(*(unsigned short *) (pkt + 2));
pkt += 4;
len -= 4;
}
if (len < 0)
return NULL;
if (is_ethertype_ip(etype)) {
memcpy(buf, pkt, len);
return handle_ip((struct ip *) buf, len);
}
return NULL;
}
dns_message *
handle_ppp(const u_char * pkt, int len)
{
char buf[PCAP_SNAPLEN];
unsigned short us;
unsigned short proto;
if (len < 2)
return NULL;
if (*pkt == PPP_ADDRESS_VAL && *(pkt + 1) == PPP_CONTROL_VAL) {
pkt += 2; /* ACFC not used */
len -= 2;
}
if (len < 2)
return NULL;
if (*pkt % 2) {
proto = *pkt; /* PFC is used */
pkt++;
len--;
} else {
memcpy(&us, pkt, sizeof(us));
proto = ntohs(us);
pkt += 2;
len -= 2;
}
if (is_ethertype_ip(proto)) {
memcpy(buf, pkt, len);
return handle_ip((struct ip *) buf, len);
}
return NULL;
}
void
handle_gre(const u_char * gre, int len, void *userdata)
{
int grelen = 4;
unsigned short flags = nptohs(gre);
unsigned short etype = nptohs(gre + 2);
if (len < grelen)
return;
if (callback_gre)
callback_gre(gre, len, userdata);
if (flags & 0x0001) /* checksum present? */
grelen += 4;
if (flags & 0x0004) /* key present? */
grelen += 4;
if (flags & 0x0008) /* sequence number present? */
grelen += 4;
if (is_ethertype_ip(etype))
handle_ip((struct ip *) (gre + grelen), len - grelen, userdata);
}
