/*
* Construct an IGMP message in the output packet buffer. The caller may
* have already placed data in that buffer, of length 'datalen'.
*/
void buildIgmp(uint32_t src, uint32_t dst, int type, int code, uint32_t group, int datalen) {
struct ip *ip;
struct igmp *igmp;
extern int curttl;
ip = (struct ip *)send_buf;
ip->ip_src.s_addr = src;
ip->ip_dst.s_addr = dst;
ip_set_len(ip, IP_HEADER_RAOPT_LEN + IGMP_MINLEN + datalen);
if (IN_MULTICAST(ntohl(dst))) {
ip->ip_ttl = curttl;
} else {
ip->ip_ttl = MAXTTL;
}
/* Add Router Alert option */
((u_char*)send_buf+MIN_IP_HEADER_LEN)[0] = IPOPT_RA;
((u_char*)send_buf+MIN_IP_HEADER_LEN)[1] = 0x04;
((u_char*)send_buf+MIN_IP_HEADER_LEN)[2] = 0x00;
((u_char*)send_buf+MIN_IP_HEADER_LEN)[3] = 0x00;
igmp = (struct igmp *)(send_buf + IP_HEADER_RAOPT_LEN);
igmp->igmp_type = type;
igmp->igmp_code = code;
igmp->igmp_group.s_addr = group;
igmp->igmp_cksum = 0;
igmp->igmp_cksum = inetChksum((u_short *)igmp,
IP_HEADER_RAOPT_LEN + datalen);
}
/** @internal @This fills ipv4/udp headers for RAW sockets
*
* @param upipe description structure of the pipe
* @param dgram raw datagram
* @param ipsrc source ip address
* @param ipdst destination ip address
* @param portsrc source port address
* @param portdst destination port address
* @param ttl datagram time-to-live
* @param tos type of service
* @param payload length
*/
static void upipe_udp_raw_fill_headers(struct upipe *upipe,
uint8_t *header,
in_addr_t ipsrc, in_addr_t ipdst,
uint16_t portsrc, uint16_t portdst,
uint8_t ttl, uint8_t tos, uint16_t len)
{
ip_set_version(header, 4);
ip_set_ihl(header, 5);
ip_set_tos(header, tos);
ip_set_len(header, len + UDP_HEADER_SIZE + IP_HEADER_MINSIZE);
ip_set_id(header, 0);
ip_set_flag_reserved(header, 0);
ip_set_flag_mf(header, 0);
ip_set_flag_df(header, 0);
ip_set_frag_offset(header, 0);
ip_set_ttl(header, ttl);
ip_set_proto(header, IPPROTO_UDP);
ip_set_cksum(header, 0);
ip_set_srcaddr(header, ntohl(ipsrc));
ip_set_dstaddr(header, ntohl(ipdst));
header += IP_HEADER_MINSIZE;
udp_set_srcport(header, portsrc);
udp_set_dstport(header, portdst);
udp_set_len(header, len + UDP_HEADER_SIZE);
udp_set_cksum(header, 0);
}
void udp_raw_set_len(uint8_t *raw_header, uint16_t len)
{
uint16_t iplen = len + UDP_HEADER_SIZE + IP_HEADER_MINSIZE;
#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__APPLE__)
iplen = htons(iplen);
#endif
ip_set_len(raw_header, iplen);
raw_header += IP_HEADER_MINSIZE;
udp_set_len(raw_header, len + UDP_HEADER_SIZE);
}
