// SPDX-License-Identifier: GPL-2.0-or-later /* * PIM for Quagga * Copyright (C) 2016 Cumulus Networks, Inc. * Daniel Walton */ #include "zebra.h" #include "pimd.h" #include "pim_instance.h" #include "pim_igmp.h" #include "pim_igmpv2.h" #include "pim_igmpv3.h" #include "pim_ssm.h" #include "pim_str.h" #include "pim_time.h" #include "pim_util.h" static void on_trace(const char *label, struct interface *ifp, struct in_addr from) { if (PIM_DEBUG_GM_TRACE) { char from_str[INET_ADDRSTRLEN]; pim_inet4_dump("", from, from_str, sizeof(from_str)); zlog_debug("%s: from %s on %s", label, from_str, ifp->name); } } void igmp_v2_send_query(struct gm_group *group, int fd, const char *ifname, char *query_buf, struct in_addr dst_addr, struct in_addr group_addr, int query_max_response_time_dsec) { ssize_t msg_size = 8; uint8_t max_resp_code; ssize_t sent; struct sockaddr_in to; socklen_t tolen; uint16_t checksum; /* max_resp_code must be non-zero else this will look like an IGMP v1 * query */ /* RFC 2236: 2.2. , v2's is equal to it */ max_resp_code = query_max_response_time_dsec; assert(max_resp_code > 0); query_buf[0] = PIM_IGMP_MEMBERSHIP_QUERY; query_buf[1] = max_resp_code; *(uint16_t *)(query_buf + IGMP_CHECKSUM_OFFSET) = 0; /* for computing checksum */ memcpy(query_buf + 4, &group_addr, sizeof(struct in_addr)); checksum = in_cksum(query_buf, msg_size); *(uint16_t *)(query_buf + IGMP_CHECKSUM_OFFSET) = checksum; if (PIM_DEBUG_GM_PACKETS) { char dst_str[INET_ADDRSTRLEN]; char group_str[INET_ADDRSTRLEN]; pim_inet4_dump("", dst_addr, dst_str, sizeof(dst_str)); pim_inet4_dump("", group_addr, group_str, sizeof(group_str)); zlog_debug("Send IGMPv2 QUERY to %s on %s for group %s", dst_str, ifname, group_str); } memset(&to, 0, sizeof(to)); to.sin_family = AF_INET; to.sin_addr = dst_addr; tolen = sizeof(to); sent = sendto(fd, query_buf, msg_size, MSG_DONTWAIT, (struct sockaddr *)&to, tolen); if (sent != (ssize_t)msg_size) { char dst_str[INET_ADDRSTRLEN]; char group_str[INET_ADDRSTRLEN]; pim_inet4_dump("", dst_addr, dst_str, sizeof(dst_str)); pim_inet4_dump("", group_addr, group_str, sizeof(group_str)); if (sent < 0) { zlog_warn( "Send IGMPv2 QUERY failed due to %s on %s: group=%s msg_size=%zd: errno=%d: %s", dst_str, ifname, group_str, msg_size, errno, safe_strerror(errno)); } else { zlog_warn( "Send IGMPv2 QUERY failed due to %s on %s: group=%s msg_size=%zd: sent=%zd", dst_str, ifname, group_str, msg_size, sent); } return; } } int igmp_v2_recv_report(struct gm_sock *igmp, struct in_addr from, const char *from_str, char *igmp_msg, int igmp_msg_len) { struct interface *ifp = igmp->interface; struct in_addr group_addr; struct pim_interface *pim_ifp; char group_str[INET_ADDRSTRLEN]; on_trace(__func__, igmp->interface, from); pim_ifp = ifp->info; if (igmp->mtrace_only) return 0; if (igmp_msg_len != IGMP_V12_MSG_SIZE) { if (PIM_DEBUG_GM_PACKETS) zlog_debug( "Recv IGMPv2 REPORT from %s on %s: size=%d other than correct=%d", from_str, ifp->name, igmp_msg_len, IGMP_V12_MSG_SIZE); } if (igmp_validate_checksum(igmp_msg, igmp_msg_len) == -1) { zlog_warn( "Recv IGMPv2 REPORT from %s on %s: size=%d with invalid checksum", from_str, ifp->name, igmp_msg_len); return -1; } /* Collecting IGMP Rx stats */ igmp->igmp_stats.report_v2++; memcpy(&group_addr, igmp_msg + 4, sizeof(struct in_addr)); if (PIM_DEBUG_GM_PACKETS) { pim_inet4_dump("", group_addr, group_str, sizeof(group_str)); zlog_debug("Recv IGMPv2 REPORT from %s on %s for %s", from_str, ifp->name, group_str); } /* * RFC 4604 * section 2.2.1 * EXCLUDE mode does not apply to SSM addresses, and an SSM-aware router * will ignore MODE_IS_EXCLUDE and CHANGE_TO_EXCLUDE_MODE requests in * the SSM range. */ if (pim_is_grp_ssm(pim_ifp->pim, group_addr)) { if (PIM_DEBUG_GM_PACKETS) { zlog_debug( "Ignoring IGMPv2 group record %pI4 from %s on %s exclude mode in SSM range", &group_addr.s_addr, from_str, ifp->name); } return -1; } /* * RFC 3376 * 7.3.2. In the Presence of Older Version Group Members * * When Group Compatibility Mode is IGMPv2, a router internally * translates the following IGMPv2 messages for that group to their * IGMPv3 equivalents: * * IGMPv2 Message IGMPv3 Equivalent * -------------- ----------------- * Report IS_EX( {} ) * Leave TO_IN( {} ) */ igmpv3_report_isex(igmp, from, group_addr, 0, NULL, 1); return 0; } int igmp_v2_recv_leave(struct gm_sock *igmp, struct ip *ip_hdr, const char *from_str, char *igmp_msg, int igmp_msg_len) { struct interface *ifp = igmp->interface; struct in_addr group_addr; char group_str[INET_ADDRSTRLEN]; struct in_addr from = ip_hdr->ip_src; on_trace(__func__, igmp->interface, from); if (igmp->mtrace_only) return 0; if (igmp_msg_len != IGMP_V12_MSG_SIZE) { if (PIM_DEBUG_GM_PACKETS) zlog_debug( "Recv IGMPv2 LEAVE from %s on %s: size=%d other than correct=%d", from_str, ifp->name, igmp_msg_len, IGMP_V12_MSG_SIZE); } if (igmp_validate_checksum(igmp_msg, igmp_msg_len) == -1) { zlog_warn( "Recv IGMPv2 LEAVE from %s on %s with invalid checksum", from_str, ifp->name); return -1; } memcpy(&group_addr, igmp_msg + 4, sizeof(struct in_addr)); if (PIM_DEBUG_GM_PACKETS) { pim_inet4_dump("", group_addr, group_str, sizeof(group_str)); zlog_debug("Recv IGMPv2 LEAVE from %s on %s for %s", from_str, ifp->name, group_str); } /* * As per RFC 2236, section 9: Message Type Destination Group ------------ ----------------- General Query ALL-SYSTEMS (224.0.0.1) Group-Specific Query The group being queried Membership Report The group being reported Leave Message ALL-ROUTERS (224.0.0.2) Note: in older (i.e., non-standard and now obsolete) versions of IGMPv2, hosts send Leave Messages to the group being left. A router SHOULD accept Leave Messages addressed to the group being left in the interests of backwards compatibility with such hosts. In all cases, however, hosts MUST send to the ALL-ROUTERS address to be compliant with this specification. */ if ((ntohl(ip_hdr->ip_dst.s_addr) != INADDR_ALLRTRS_GROUP) && (ip_hdr->ip_dst.s_addr != group_addr.s_addr)) { if (PIM_DEBUG_GM_EVENTS) zlog_debug( "IGMPv2 Leave message is ignored since received on address other than ALL-ROUTERS or Group-address"); return -1; } /* Collecting IGMP Rx stats */ igmp->igmp_stats.leave_v2++; /* * RFC 3376 * 7.3.2. In the Presence of Older Version Group Members * * When Group Compatibility Mode is IGMPv2, a router internally * translates the following IGMPv2 messages for that group to their * IGMPv3 equivalents: * * IGMPv2 Message IGMPv3 Equivalent * -------------- ----------------- * Report IS_EX( {} ) * Leave TO_IN( {} ) */ igmpv3_report_toin(igmp, from, group_addr, 0, NULL); return 0; }