/*
* Send an UDP packet from port sport to host ``daddr''
* and port ``dport''. The arguments are in host byte order.
*/
int
udp_send(port_t sport, ipaddr_t daddr, port_t dport, void *data, int len)
{
static unsigned short ipid = 1;
udphdr_t *up;
char *msg;
int rv, udplen;
pseudohdr_t ph;
extern ipaddr_t my_ipaddr;
if (!my_ipaddr && !ip_init())
return -1;
if (extra_info())
{
printf("udp_send(%d, %s, %d, %p, %d)\n", sport, inet_ntoa(daddr), dport, data, len);
}
udplen = len + sizeof(udphdr_t);
if ((msg = malloc(align(udplen))) == NULL) {
printf("%s, %d: malloc failed\n", __LINE__, __FILE__);
return -1;
}
up = (udphdr_t *) msg;
up->uh_sport = htons(sport);
up->uh_dport = htons(dport);
up->uh_len = htons(udplen);
up->uh_sum = 0;
memcpy(msg + sizeof(udphdr_t), data, len);
/* compute UDP checksum */
ph.ph_src = my_ipaddr;
ph.ph_dst = daddr;
ph.ph_zero = 0;
ph.ph_p = IP_PROTO_UDP;
ph.ph_len = up->uh_len;
up->uh_sum = ~inet_checksum(&ph, sizeof(ph));
if (udplen & 1)
msg[udplen] = '\0';
up->uh_sum = inet_checksum(up, align(udplen));
if (up->uh_sum == 0)
up->uh_sum = 0xFFFF;
rv = ip_send(daddr, IP_PROTO_UDP, ipid++, msg, udplen);
free(msg);
/* return rv; */
return len;
}
int
tcp_opt_apply(void *d, struct pktq *pktq, struct rule **next_rule)
{
struct tcp_opt *opt = (struct tcp_opt *)d;
struct pkt *pkt;
size_t len;
TAILQ_FOREACH(pkt, pktq, pkt_next) {
uint16_t eth_type = htons(pkt->pkt_eth->eth_type);
len = inet_add_option(eth_type, pkt->pkt_ip,
sizeof(pkt->pkt_data) - ETH_HDR_LEN,
IP_PROTO_TCP, opt, opt->opt_len);
if (len > 0) {
pkt->pkt_end += len;
pkt_decorate(pkt);
inet_checksum(eth_type, pkt->pkt_ip, pkt->pkt_end - pkt->pkt_eth_data);
}
}
