/*
* Call build_igmp() to build an IGMP message in the output packet buffer.
* Then send the message from the interface with IP address 'src' to
* destination 'dst'.
*/
void sendIgmp(uint32_t src, uint32_t dst, int type, int code, uint32_t group, int datalen) {
struct sockaddr_in sdst;
int setloop = 0, setigmpsource = 0;
buildIgmp(src, dst, type, code, group, datalen);
if (IN_MULTICAST(ntohl(dst))) {
k_set_if(src);
setigmpsource = 1;
if (type != IGMP_DVMRP || dst == allhosts_group) {
setloop = 1;
k_set_loop(true);
}
}
memset(&sdst, 0, sizeof(sdst));
sdst.sin_family = AF_INET;
#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
sdst.sin_len = sizeof(sdst);
#endif
sdst.sin_addr.s_addr = dst;
if (sendto(MRouterFD, send_buf,
IP_HEADER_RAOPT_LEN + IGMP_MINLEN + datalen, 0,
(struct sockaddr *)&sdst, sizeof(sdst)) < 0) {
if (errno == ENETDOWN)
my_log(LOG_ERR, errno, "Sender VIF was down.");
else
my_log(LOG_INFO, errno,
"sendto to %s on %s",
inetFmt(dst, s1), inetFmt(src, s2));
}
if(setigmpsource) {
if (setloop) {
k_set_loop(false);
}
// Restore original...
k_set_if(INADDR_ANY);
}
my_log(LOG_DEBUG, 0, "SENT %s from %-15s to %s",
igmpPacketKind(type, code), src == INADDR_ANY ? "INADDR_ANY" :
inetFmt(src, s1), inetFmt(dst, s2));
}
int pimdm_output(char *buf,u_int32 src,u_int32 dst,int type,int length)
{//提供缓存，源、目的、类型和长度，发送PIM报文
struct sockaddr_in sockdst;
struct ip *ip;
struct pim *pim;
int sendlen;
int setloop=0;
ip=(struct ip*)buf;
ip->ip_v=4;
ip->ip_hl=(sizeof(struct ip)>>2);
ip->ip_tos=0;
ip->ip_id=0;
ip->ip_off=0;
ip->ip_p=IPPROTO_PIM;
ip->ip_sum=0;
ip->ip_len=sizeof(struct ip)+sizeof(struct pim)+length;
ip->ip_src.s_addr=src;
ip->ip_dst.s_addr=dst;
ip->ip_ttl=1;
sendlen=ip->ip_len;
pim=(struct pim *)(buf+sizeof(struct ip));
pim->pim_type=type;
pim->pim_vers=2;
pim->pim_cksum=0;
pim->pim_cksum=inet_cksum((u_int16 *)pim,sizeof(struct pim)+length);
if(IN_MULTICAST(ntohl(dst)))
{
k_set_if(pimsocket,src);
setloop=1;
k_set_loop(pimsocket,1);
}
bzero((void *)&sockdst,sizeof(sockdst));
sockdst.sin_family=AF_INET;
sockdst.sin_len=sizeof(sockdst);
sockdst.sin_addr.s_addr=dst;
if (sendto(pimsocket,pim_send_buf,sendlen,0,(struct sockaddr *)&sockdst,sizeof(sockdst))<0)
{
if (setloop)
k_set_loop(pimsocket,0);
return 0;
}
if (setloop)
k_set_loop(pimsocket,0);
return 1;
}
/*
* Call build_igmp() to build an IGMP message in the output packet buffer.
* Then send the message from the interface with IP address 'src' to
* destination 'dst'.
*/
void send_igmp(u_int32 src, u_int32 dst, int type, int code, u_int32 group, int datalen)
{
struct sockaddr_in sdst;
int setloop = 0;
size_t len;
len = build_igmp(src, dst, type, code, group, datalen);
if (IN_MULTICAST(ntohl(dst))) {
k_set_if(src);
if (type != IGMP_DVMRP || dst == allhosts_group) {
setloop = 1;
k_set_loop(TRUE);
}
}
memset(&sdst, 0, sizeof(sdst));
sdst.sin_family = AF_INET;
#ifdef HAVE_SA_LEN
sdst.sin_len = sizeof(sdst);
#endif
sdst.sin_addr.s_addr = dst;
if (sendto(igmp_socket, send_buf, len, 0, (struct sockaddr *)&sdst, sizeof(sdst)) < 0) {
if (errno == ENETDOWN)
check_vif_state();
else
logit(igmp_log_level(type, code), errno,
"sendto to %s on %s",
inet_fmt(dst, s1, sizeof(s1)), inet_fmt(src, s2, sizeof(s2)));
}
if (setloop)
k_set_loop(FALSE);
IF_DEBUG(DEBUG_PKT|igmp_debug_kind(type, code))
logit(LOG_DEBUG, 0, "SENT %s from %-15s to %s",
igmp_packet_kind(type, code), src == INADDR_ANY ? "INADDR_ANY" :
inet_fmt(src, s1, sizeof(s1)), inet_fmt(dst, s2, sizeof(s2)));
}
