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/*
* (c) BayCom GmbH, http://www.baycom.de, info@baycom.de
*
* See the COPYING file for copyright information and
* how to reach the author.
*
*/
#undef DEBUG
#include "headers.h"
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
int send_mldv2_report (struct intnode *intn, int grec_number, struct in6_addr *mcas, int srcn, struct in6_addr *sources, int mode)
{
unsigned int length;
struct mld_report_packet
{
struct ip6_hdr ip6;
struct ip6_hbh hbh;
struct
{
uint8_t type;
uint8_t length;
uint16_t value;
uint8_t optpad[2];
} routeralert;
struct mld2_report mld2r;
} *packet;
struct mld2_grec *grec = NULL;
struct in6_addr *src = NULL;
int mca_index, src_index;
int count = 0;
//printf("creating multicast listener report packet....\n");
//printf("size src = %d size grec = %d \n",sizeof(*src),sizeof(*grec));
if (intn->mtu < sizeof (*packet)) {
/*
* MTU is too small to support this type of packet
* Should not happen though
*/
dbg ("MTU too small for packet while sending MLDv2 report on interface %s/%u mtu=%u!?\n", intn->name, intn->ifindex, intn->mtu);
return -1;
}
/* Allocate a buffer matching the MTU size of this interface */
packet = (struct mld_report_packet *) malloc (intn->mtu);
if (!packet) {
err ("Cannot get memory for MLD2 report packet, aborting\n");
}
// printf("addr packet = %u \n",packet);
memset (packet, 0, intn->mtu);
/* Create the IPv6 packet */
packet->ip6.ip6_vfc = 0x60;
packet->ip6.ip6_plen = ntohs (sizeof (*packet) - sizeof (packet->ip6));
packet->ip6.ip6_nxt = IPPROTO_HOPOPTS;
packet->ip6.ip6_hlim = 1;
/*
* The source address must be the link-local address
* of the interface we are sending on
*/
memcpy (&packet->ip6.ip6_src, &intn->linklocal, sizeof (packet->ip6.ip6_src));
/* MLDv2 Report -> All IPv6 Multicast Routers (ff02::16) */
packet->ip6.ip6_dst.s6_addr[0] = 0xff;
packet->ip6.ip6_dst.s6_addr[1] = 0x02;
packet->ip6.ip6_dst.s6_addr[15] = 0x16;
/* HopByHop Header Extension */
packet->hbh.ip6h_nxt = IPPROTO_ICMPV6;
packet->hbh.ip6h_len = 0;
/* Router Alert Option */
packet->routeralert.type = 5;
packet->routeralert.length = sizeof (packet->routeralert.value);
packet->routeralert.value = 0; /* MLD ;) */
/* Option Padding */
packet->routeralert.optpad[0] = IP6OPT_PADN;
packet->routeralert.optpad[1] = 0;
/* ICMPv6 MLD Report */
packet->mld2r.type = ICMP6_V2_MEMBERSHIP_REPORT;
//number of multi cast address reocrds
packet->mld2r.ngrec = 0; //grec_number;//htons(1);
length = 0;
count = 0;
for (mca_index = 0; mca_index < grec_number; mca_index++) {
src = NULL;
if (!grec) {
length = sizeof (*packet) + sizeof (*grec) - sizeof (packet->ip6);
//fprintf(stdout,"(grec = %02d) %02d. current report length = %04d MTU: %04d)\n",packet->mld2r.ngrec,mca_index,length+sizeof(packet->ip6),intn->mtu);
if (length + sizeof (packet->ip6) > intn->mtu) {
/* Should not happen! Would mean the MTU is smaller than a standard mld report */
dbg ("No grec and MTU too small for packet while sending MLDv2 report on interface %s/%u mtu=%u!?\n", intn->name, intn->ifindex, intn->mtu);
free (packet);
return (-1);
} else
grec = (struct mld2_grec *) (((char *) packet) + sizeof (*packet));
packet->mld2r.ngrec++;
} else {
if (!src)
length = ((((char *) grec) - ((char *) packet)) + sizeof (*grec) + (sizeof (*src) * (grec->grec_nsrcs))) - sizeof (packet->ip6);
//fprintf(stdout,"\nloop1:(grec = %02d) %02d.length = %04d (Total : %04d MTU: %04d)\n\n", packet->mld2r.ngrec , mca_index,length,(length + sizeof(packet->ip6)), intn->mtu);
if (((length + sizeof (packet->ip6) + sizeof (*grec)) > intn->mtu)) {
/* Take care of endianess */
//fprintf(stdout,"next grec record does not fit... sending... \n");
packet->mld2r.ngrec = htons (packet->mld2r.ngrec);
grec->grec_nsrcs = htons (grec->grec_nsrcs);
/* Calculate and fill in the checksum */
packet->ip6.ip6_plen = htons (length);
packet->mld2r.csum = htons (0);
packet->mld2r.csum = ipv6_checksum (&packet->ip6, IPPROTO_ICMPV6, (uint8_t *) & packet->mld2r, length - sizeof (struct ip6_hbh) - sizeof (packet->routeralert));
count++;
#ifdef DEBUG
dbg ("%04d.Sending2 MLDv2 Report on %s/%u, ngrec=%u, length=%u sources=%u (in last grec)\n", count, intn->name, intn->ifindex, ntohs (packet->mld2r.ngrec), length, ntohs (grec->grec_nsrcs));
sendpacket6 (intn, (const struct ip6_hdr *) packet, length + sizeof (packet->ip6));
#endif
/* Increase ICMP sent statistics */
g_conf->stat_icmp_sent++;
intn->stat_icmp_sent++;
/* Reset the MLDv2 struct */
packet->mld2r.ngrec = 0;
grec = (struct mld2_grec *) (((char *) packet) + sizeof (*packet));
} else {
//next grec
grec->grec_nsrcs = htons (grec->grec_nsrcs);
grec = (struct mld2_grec *) (((char *) grec) + sizeof (*grec) + (sizeof (*src) * ntohs (grec->grec_nsrcs)));
}
packet->mld2r.ngrec++;
}
//Copy MCA to record
memcpy (&grec->grec_mca, mcas + mca_index, sizeof (grec->grec_mca));
/* Zero sources upto now */
grec->grec_nsrcs = 0;
/* 0 Sources -> Exclude those */
grec->grec_type = MLD2_MODE_IS_EXCLUDE;
if (mode) {
grec->grec_type = mode;
}
/* Nothing added yet */
for (src_index = 0; src_index < srcn || (!srcn && src_index == 0); src_index++) {
//check for duplicate source reocrds and any address
/* Packet with at least one grec and one or more src's, excluding ip6 header */
length = (((char *) grec) - ((char *) packet)) + sizeof (*grec) + (sizeof (*src) * (grec->grec_nsrcs)) - sizeof (packet->ip6);
//fprintf(stdout,"loop2:(grec = %02d) %02d.length = %04d (Total : %04d MTU: %04d)\n", packet->mld2r.ngrec,mca_index,length,(length + sizeof(packet->ip6)),intn->mtu);
/* Would adding it not fit? -> Send it out */
if (((length + sizeof (packet->ip6) + sizeof (*src)) > (intn->mtu)) && srcn) {
//fprintf(stdout,"next source addr. does not fit... sending... \n");
//fprintf(stdout,"src_index = %d grec->grec_nsrcs = %d \n",src_index,grec->grec_nsrcs);
/* Take care of endianess */
packet->mld2r.ngrec = htons (packet->mld2r.ngrec);
grec->grec_nsrcs = htons (grec->grec_nsrcs);
/* Calculate and fill in the checksum */
packet->ip6.ip6_plen = htons (length);
packet->mld2r.csum = htons (0);
packet->mld2r.csum = ipv6_checksum (&packet->ip6, IPPROTO_ICMPV6, (uint8_t *) & packet->mld2r, length - sizeof (struct ip6_hbh) - sizeof (packet->routeralert));
count++;
dbg ("%04d.Sending2 MLDv2 Report on %s/%u, ngrec=%u, length=%u sources=%u (in last grec)\n", count, intn->name, intn->ifindex, ntohs (packet->mld2r.ngrec), length, ntohs (grec->grec_nsrcs));
sendpacket6 (intn, (const struct ip6_hdr *) packet, length + sizeof (packet->ip6));
/* Increase ICMP sent statistics */
g_conf->stat_icmp_sent++;
intn->stat_icmp_sent++;
/* Reset the MLDv2 struct */
packet->mld2r.ngrec = 0;
src = NULL;
grec = NULL;
//if not IS_EX or TO EXCLUDE_MODE splitting must be done
break;
}
/* Only add non-:: addresses */
if (!srcn)
break;
if (!IN6_IS_ADDR_UNSPECIFIED (sources + src_index) && srcn) {
/* First/Next address */
src = (struct in6_addr *) (((char *) grec) + sizeof (*grec) + (sizeof (*src) * grec->grec_nsrcs));
/* An additional source */
grec->grec_nsrcs++;
if (mode) {
grec->grec_type = mode; //MLD2_MODE_IS_EXCLUDE;
}
/* Append the source address */
memcpy (src, sources + src_index, sizeof (*src));
}
}
}
//fprintf(stdout,"done\n");
if (packet->mld2r.ngrec == 0) {
//fprintf(stdout,"All data sent !!!!!!\n");
free (packet);
packet = NULL;
return (1);
}
/* Take care of endianess */
length = (((char *) grec) - ((char *) packet) + sizeof (*grec) + (sizeof (*src) * (grec->grec_nsrcs)) - sizeof (packet->ip6));
packet->mld2r.ngrec = htons (packet->mld2r.ngrec);
grec->grec_nsrcs = htons (grec->grec_nsrcs);
/* Calculate and fill in the checksum */
packet->ip6.ip6_plen = htons (length);
packet->mld2r.csum = htons (0);
packet->mld2r.csum = ipv6_checksum (&packet->ip6, IPPROTO_ICMPV6, (uint8_t *) & packet->mld2r, length - sizeof (struct ip6_hbh) - sizeof (packet->routeralert));
count++;
dbg ("%04d.Sending2 MLDv2 Report on %s/%u, ngrec=%u, length=%u sources=%u (in last grec)\n", count, intn->name, intn->ifindex, ntohs (packet->mld2r.ngrec), length, ntohs (grec->grec_nsrcs));
sendpacket6 (intn, (const struct ip6_hdr *) packet, length + sizeof (packet->ip6));
/* Increase ICMP sent statistics */
g_conf->stat_icmp_sent++;
intn->stat_icmp_sent++;
free (packet);
//fprintf(stdout,"Total ICMP packets sent = %llu\n", intn->stat_icmp_sent );
return 0;
}
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