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;
}
/*
* Open and initialize the igmp socket, and fill in the non-changing
* IP header fields in the output packet buffer.
*/
void initIgmp() {
struct ip *ip;
recv_buf = malloc(RECV_BUF_SIZE);
send_buf = malloc(RECV_BUF_SIZE);
k_hdr_include(true); /* include IP header when sending */
k_set_rcvbuf(256*1024,48*1024); /* lots of input buffering */
k_set_ttl(1); /* restrict multicasts to one hop */
k_set_loop(false); /* disable multicast loopback */
ip = (struct ip *)send_buf;
memset(ip, 0, sizeof(struct ip));
/*
* Fields zeroed that aren't filled in later:
* - IP ID (let the kernel fill it in)
* - Offset (we don't send fragments)
* - Checksum (let the kernel fill it in)
*/
ip->ip_v = IPVERSION;
ip->ip_hl = (sizeof(struct ip) + 4) >> 2; /* +4 for Router Alert option */
ip->ip_tos = 0xc0; /* Internet Control */
ip->ip_ttl = MAXTTL; /* applies to unicasts only */
ip->ip_p = IPPROTO_IGMP;
allhosts_group = htonl(INADDR_ALLHOSTS_GROUP);
allrouters_group = htonl(INADDR_ALLRTRS_GROUP);
alligmp3_group = htonl(INADDR_ALLIGMPV3_GROUP);
}
/*
* Open and initialize the igmp socket, and fill in the non-changing
* IP header fields in the output packet buffer.
*/
void init_igmp(void)
{
struct ip *ip;
recv_buf = malloc(RECV_BUF_SIZE);
send_buf = malloc(RECV_BUF_SIZE);
if ((igmp_socket = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP)) < 0)
logit(LOG_ERR, errno, "IGMP socket");
k_hdr_include(TRUE); /* include IP header when sending */
k_set_rcvbuf(256*1024,48*1024); /* lots of input buffering */
k_set_ttl(1); /* restrict multicasts to one hop */
k_set_loop(FALSE); /* disable multicast loopback */
ip = (struct ip *)send_buf;
memset(ip, 0, sizeof(struct ip));
/*
* Fields zeroed that aren't filled in later:
* - IP ID (let the kernel fill it in)
* - Offset (we don't send fragments)
* - Checksum (let the kernel fill it in)
*/
ip->ip_v = IPVERSION;
ip->ip_hl = sizeof(struct ip) >> 2;
ip->ip_tos = 0xc0; /* Internet Control */
ip->ip_ttl = MAXTTL; /* applies to unicasts only */
ip->ip_p = IPPROTO_IGMP;
allhosts_group = htonl(INADDR_ALLHOSTS_GROUP);
dvmrp_group = htonl(INADDR_DVMRP_GROUP);
allrtrs_group = htonl(INADDR_ALLRTRS_GROUP);
}
/*
* 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));
}
/*
* 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)));
}
/*
* Open and initialize the igmp socket, and fill in the non-changing
* IP header fields in the output packet buffer.
*/
void init_igmp(void)
{
struct ip *ip;
char *router_alert;
igmp_recv_buf = calloc(1, RECV_BUF_SIZE);
igmp_send_buf = calloc(1, SEND_BUF_SIZE);
if (!igmp_recv_buf || !igmp_send_buf)
logit(LOG_ERR, 0, "Ran out of memory in init_igmp()");
if ((igmp_socket = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP)) < 0)
logit(LOG_ERR, errno, "Failed creating IGMP socket in init_igmp()");
k_hdr_include(igmp_socket, TRUE); /* include IP header when sending */
k_set_sndbuf(igmp_socket, SO_SEND_BUF_SIZE_MAX,
SO_SEND_BUF_SIZE_MIN); /* lots of output buffering */
k_set_rcvbuf(igmp_socket, SO_RECV_BUF_SIZE_MAX,
SO_RECV_BUF_SIZE_MIN); /* lots of input buffering */
k_set_ttl(igmp_socket, MINTTL); /* restrict multicasts to one hop */
k_set_loop(igmp_socket, FALSE); /* disable multicast loopback */
ip = (struct ip *)igmp_send_buf;
memset(ip, 0, IP_IGMP_HEADER_LEN);
ip->ip_v = IPVERSION;
ip->ip_hl = IP_IGMP_HEADER_LEN >> 2;
ip->ip_tos = 0xc0; /* Internet Control */
ip->ip_id = 0; /* let kernel fill in */
ip->ip_off = 0;
ip->ip_ttl = MAXTTL; /* applies to unicasts only */
ip->ip_p = IPPROTO_IGMP;
ip->ip_sum = 0; /* let kernel fill in */
/* Enable RFC2113 IP Router Alert. Per spec this is required to
* force certain routers/switches to inspect this frame. */
router_alert = igmp_send_buf + sizeof(struct ip);
router_alert[0] = IPOPT_RA;
router_alert[1] = 4;
router_alert[2] = 0;
router_alert[3] = 0;
/* Everywhere in the daemon we use network-byte-order */
allhosts_group = htonl(INADDR_ALLHOSTS_GROUP);
allrouters_group = htonl(INADDR_ALLRTRS_GROUP);
allreports_group = htonl(INADDR_ALLRPTS_GROUP);
if (register_input_handler(igmp_socket, igmp_read) < 0)
logit(LOG_ERR, 0, "Failed registering igmp_read() as an input handler in init_igmp()");
}
void init_pim()
{//初始化
allpimrouters=htonl(INADDR_ALLPIM_ROUTERS_GROUP);
pim_receive_buf=malloc(64*1024);
pim_send_buf=malloc(64*1024);
if((pimsocket=socket(AF_INET,SOCK_RAW,IPPROTO_PIM))<0)
log(LOG_ERR,"igmp socket create failed!");
k_hdr_include(pimsocket,1);//发送的时候包括IP头部
k_set_rcvbuf(pimsocket,256*1024,48*1024);
k_set_ttl(pimsocket,1);//设置IGMP报文的TTL为1
k_set_loop(pimsocket,0);//决定发送的多点广播包不应该被回送
if(register_input_handler(pimsocket,pim_input)<0)
log(LOG_ERR,"Couldn't register pim_input as an input handler");
}
/*
* Setup raw kernel socket for PIM protocol and send/receive buffers.
*/
void init_pim(void)
{
struct ip *ip;
/* Setup the PIM raw socket */
if ((pim_socket = socket(AF_INET, SOCK_RAW, IPPROTO_PIM)) < 0)
logit(LOG_ERR, errno, "Failed creating PIM socket");
k_hdr_include(pim_socket, TRUE); /* include IP header when sending */
k_set_sndbuf(pim_socket, SO_SEND_BUF_SIZE_MAX,
SO_SEND_BUF_SIZE_MIN); /* lots of output buffering */
k_set_rcvbuf(pim_socket, SO_RECV_BUF_SIZE_MAX,
SO_RECV_BUF_SIZE_MIN); /* lots of input buffering */
k_set_ttl(pim_socket, MINTTL); /* restrict multicasts to one hop */
k_set_loop(pim_socket, FALSE); /* disable multicast loopback */
allpimrouters_group = htonl(INADDR_ALL_PIM_ROUTERS);
pim_recv_buf = calloc(1, RECV_BUF_SIZE);
pim_send_buf = calloc(1, SEND_BUF_SIZE);
if (!pim_recv_buf || !pim_send_buf)
logit(LOG_ERR, 0, "Ran out of memory in init_pim()");
/* One time setup in the buffers */
ip = (struct ip *)pim_send_buf;
memset(ip, 0, sizeof(*ip));
ip->ip_v = IPVERSION;
ip->ip_hl = (sizeof(struct ip) >> 2);
ip->ip_tos = 0; /* TODO: setup?? */
ip->ip_id = 0; /* Make sure to update ID field, maybe fragmenting below */
ip->ip_off = 0;
ip->ip_p = IPPROTO_PIM;
ip->ip_sum = 0; /* let kernel fill in */
if (register_input_handler(pim_socket, pim_read) < 0)
logit(LOG_ERR, 0, "Failed registering pim_read() as an input handler");
/* Initialize the building Join/Prune messages working area */
build_jp_message_pool = (build_jp_message_t *)NULL;
build_jp_message_pool_counter = 0;
}
