int pim_pim_packet(struct interface *ifp, uint8_t *buf, size_t len) { struct ip *ip_hdr; size_t ip_hlen; /* ip header length in bytes */ char src_str[100]; char dst_str[100]; uint8_t *pim_msg; int pim_msg_len; uint8_t pim_version; uint8_t pim_type; uint16_t pim_checksum; /* received checksum */ uint16_t checksum; /* computed checksum */ struct pim_neighbor *neigh; if (!ifp->info) { zlog_warn("%s: PIM not enabled on interface %s", __PRETTY_FUNCTION__, ifp->name); return -1; } if (len < sizeof(*ip_hdr)) { zlog_warn("PIM packet size=%zu shorter than minimum=%zu", len, sizeof(*ip_hdr)); return -1; } ip_hdr = (struct ip *) buf; pim_inet4_dump("<src?>", ip_hdr->ip_src, src_str, sizeof(src_str)); pim_inet4_dump("<dst?>", ip_hdr->ip_dst, dst_str, sizeof(dst_str)); ip_hlen = ip_hdr->ip_hl << 2; /* ip_hl gives length in 4-byte words */ if (PIM_DEBUG_PIM_PACKETS) { zlog_debug("Recv IP packet from %s to %s on %s: size=%zu ip_header_size=%zu ip_proto=%d", src_str, dst_str, ifp->name, len, ip_hlen, ip_hdr->ip_p); } if (ip_hdr->ip_p != PIM_IP_PROTO_PIM) { zlog_warn("IP packet protocol=%d is not PIM=%d", ip_hdr->ip_p, PIM_IP_PROTO_PIM); return -1; } if (ip_hlen < PIM_IP_HEADER_MIN_LEN) { zlog_warn("IP packet header size=%zu shorter than minimum=%d", ip_hlen, PIM_IP_HEADER_MIN_LEN); return -1; } if (ip_hlen > PIM_IP_HEADER_MAX_LEN) { zlog_warn("IP packet header size=%zu greater than maximum=%d", ip_hlen, PIM_IP_HEADER_MAX_LEN); return -1; } pim_msg = buf + ip_hlen; pim_msg_len = len - ip_hlen; if (PIM_DEBUG_PIM_PACKETDUMP_RECV) { pim_pkt_dump(__PRETTY_FUNCTION__, pim_msg, pim_msg_len); } if (pim_msg_len < PIM_PIM_MIN_LEN) { zlog_warn("PIM message size=%d shorter than minimum=%d", pim_msg_len, PIM_PIM_MIN_LEN); return -1; } pim_version = PIM_MSG_HDR_GET_VERSION(pim_msg); pim_type = PIM_MSG_HDR_GET_TYPE(pim_msg); if (pim_version != PIM_PROTO_VERSION) { zlog_warn("Ignoring PIM pkt from %s with unsupported version: %d", ifp->name, pim_version); return -1; } /* save received checksum */ pim_checksum = PIM_MSG_HDR_GET_CHECKSUM(pim_msg); /* for computing checksum */ *(uint16_t *) PIM_MSG_HDR_OFFSET_CHECKSUM(pim_msg) = 0; checksum = in_cksum(pim_msg, pim_msg_len); if (checksum != pim_checksum) { zlog_warn("Ignoring PIM pkt from %s with invalid checksum: received=%x calculated=%x", ifp->name, pim_checksum, checksum); return -1; } if (PIM_DEBUG_PIM_PACKETS) { zlog_debug("Recv PIM packet from %s to %s on %s: ttl=%d pim_version=%d pim_type=%d pim_msg_size=%d checksum=%x", src_str, dst_str, ifp->name, ip_hdr->ip_ttl, pim_version, pim_type, pim_msg_len, checksum); } if (pim_type == PIM_MSG_TYPE_REGISTER || pim_type == PIM_MSG_TYPE_REG_STOP || pim_type == PIM_MSG_TYPE_BOOTSTRAP || pim_type == PIM_MSG_TYPE_GRAFT || pim_type == PIM_MSG_TYPE_GRAFT_ACK || pim_type == PIM_MSG_TYPE_CANDIDATE) { if (PIM_DEBUG_PIM_PACKETS) { zlog_debug("Recv PIM packet type %d which is not currently understood", pim_type); } return -1; } if (pim_type == PIM_MSG_TYPE_HELLO) { int result = pim_hello_recv(ifp, ip_hdr->ip_src, pim_msg + PIM_MSG_HEADER_LEN, pim_msg_len - PIM_MSG_HEADER_LEN); return result; } neigh = pim_neighbor_find(ifp, ip_hdr->ip_src); if (!neigh) { zlog_warn("%s %s: non-hello PIM message type=%d from non-neighbor %s on %s", __FILE__, __PRETTY_FUNCTION__, pim_type, src_str, ifp->name); return -1; } switch (pim_type) { case PIM_MSG_TYPE_JOIN_PRUNE: return pim_joinprune_recv(ifp, neigh, ip_hdr->ip_src, pim_msg + PIM_MSG_HEADER_LEN, pim_msg_len - PIM_MSG_HEADER_LEN); case PIM_MSG_TYPE_ASSERT: return pim_assert_recv(ifp, neigh, ip_hdr->ip_src, pim_msg + PIM_MSG_HEADER_LEN, pim_msg_len - PIM_MSG_HEADER_LEN); default: zlog_warn("%s %s: unsupported PIM message type=%d from %s on %s", __FILE__, __PRETTY_FUNCTION__, pim_type, src_str, ifp->name); } return -1; }
int pim_hello_recv(struct interface *ifp, struct in_addr src_addr, uint8_t *tlv_buf, int tlv_buf_size) { struct pim_interface *pim_ifp; struct pim_neighbor *neigh; uint8_t *tlv_curr; uint8_t *tlv_pastend; pim_hello_options hello_options = 0; /* bit array recording options found */ uint16_t hello_option_holdtime = 0; uint16_t hello_option_propagation_delay = 0; uint16_t hello_option_override_interval = 0; uint32_t hello_option_dr_priority = 0; uint32_t hello_option_generation_id = 0; struct list *hello_option_addr_list = 0; if (PIM_DEBUG_PIM_HELLO) on_trace(__PRETTY_FUNCTION__, ifp, src_addr); pim_ifp = ifp->info; zassert(pim_ifp); ++pim_ifp->pim_ifstat_hello_recv; /* Parse PIM hello TLVs */ zassert(tlv_buf_size >= 0); tlv_curr = tlv_buf; tlv_pastend = tlv_buf + tlv_buf_size; while (tlv_curr < tlv_pastend) { uint16_t option_type; uint16_t option_len; int remain = tlv_pastend - tlv_curr; if (remain < PIM_TLV_MIN_SIZE) { if (PIM_DEBUG_PIM_HELLO) { char src_str[INET_ADDRSTRLEN]; pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str)); zlog_debug( "%s: short PIM hello TLV size=%d < min=%d from %s on interface %s", __PRETTY_FUNCTION__, remain, PIM_TLV_MIN_SIZE, src_str, ifp->name); } FREE_ADDR_LIST_THEN_RETURN(-1); } option_type = PIM_TLV_GET_TYPE(tlv_curr); tlv_curr += PIM_TLV_TYPE_SIZE; option_len = PIM_TLV_GET_LENGTH(tlv_curr); tlv_curr += PIM_TLV_LENGTH_SIZE; if ((tlv_curr + option_len) > tlv_pastend) { if (PIM_DEBUG_PIM_HELLO) { char src_str[INET_ADDRSTRLEN]; pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str)); zlog_debug( "%s: long PIM hello TLV type=%d length=%d > left=%td from %s on interface %s", __PRETTY_FUNCTION__, option_type, option_len, tlv_pastend - tlv_curr, src_str, ifp->name); } FREE_ADDR_LIST_THEN_RETURN(-2); } if (PIM_DEBUG_PIM_HELLO) { char src_str[INET_ADDRSTRLEN]; pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str)); zlog_debug( "%s: parse left_size=%d: PIM hello TLV type=%d length=%d from %s on %s", __PRETTY_FUNCTION__, remain, option_type, option_len, src_str, ifp->name); } switch (option_type) { case PIM_MSG_OPTION_TYPE_HOLDTIME: if (pim_tlv_parse_holdtime(ifp->name, src_addr, &hello_options, &hello_option_holdtime, option_len, tlv_curr)) { FREE_ADDR_LIST_THEN_RETURN(-3); } break; case PIM_MSG_OPTION_TYPE_LAN_PRUNE_DELAY: if (pim_tlv_parse_lan_prune_delay( ifp->name, src_addr, &hello_options, &hello_option_propagation_delay, &hello_option_override_interval, option_len, tlv_curr)) { FREE_ADDR_LIST_THEN_RETURN(-4); } break; case PIM_MSG_OPTION_TYPE_DR_PRIORITY: if (pim_tlv_parse_dr_priority(ifp->name, src_addr, &hello_options, &hello_option_dr_priority, option_len, tlv_curr)) { FREE_ADDR_LIST_THEN_RETURN(-5); } break; case PIM_MSG_OPTION_TYPE_GENERATION_ID: if (pim_tlv_parse_generation_id( ifp->name, src_addr, &hello_options, &hello_option_generation_id, option_len, tlv_curr)) { FREE_ADDR_LIST_THEN_RETURN(-6); } break; case PIM_MSG_OPTION_TYPE_ADDRESS_LIST: if (pim_tlv_parse_addr_list(ifp->name, src_addr, &hello_options, &hello_option_addr_list, option_len, tlv_curr)) { return -7; } break; case PIM_MSG_OPTION_TYPE_DM_STATE_REFRESH: if (PIM_DEBUG_PIM_HELLO) { char src_str[INET_ADDRSTRLEN]; pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str)); zlog_debug( "%s: ignoring PIM hello dense-mode state refresh TLV option type=%d length=%d from %s on interface %s", __PRETTY_FUNCTION__, option_type, option_len, src_str, ifp->name); } break; default: if (PIM_DEBUG_PIM_HELLO) { char src_str[INET_ADDRSTRLEN]; pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str)); zlog_debug( "%s: ignoring unknown PIM hello TLV type=%d length=%d from %s on interface %s", __PRETTY_FUNCTION__, option_type, option_len, src_str, ifp->name); } } tlv_curr += option_len; } /* Check received PIM hello options */ if (PIM_DEBUG_PIM_HELLO) { tlv_trace_uint16(__PRETTY_FUNCTION__, "holdtime", ifp->name, src_addr, PIM_OPTION_IS_SET(hello_options, PIM_OPTION_MASK_HOLDTIME), hello_option_holdtime); tlv_trace_uint16( __PRETTY_FUNCTION__, "propagation_delay", ifp->name, src_addr, PIM_OPTION_IS_SET(hello_options, PIM_OPTION_MASK_LAN_PRUNE_DELAY), hello_option_propagation_delay); tlv_trace_uint16( __PRETTY_FUNCTION__, "override_interval", ifp->name, src_addr, PIM_OPTION_IS_SET(hello_options, PIM_OPTION_MASK_LAN_PRUNE_DELAY), hello_option_override_interval); tlv_trace_bool( __PRETTY_FUNCTION__, "can_disable_join_suppression", ifp->name, src_addr, PIM_OPTION_IS_SET(hello_options, PIM_OPTION_MASK_LAN_PRUNE_DELAY), PIM_OPTION_IS_SET( hello_options, PIM_OPTION_MASK_CAN_DISABLE_JOIN_SUPPRESSION)); tlv_trace_uint32(__PRETTY_FUNCTION__, "dr_priority", ifp->name, src_addr, PIM_OPTION_IS_SET(hello_options, PIM_OPTION_MASK_DR_PRIORITY), hello_option_dr_priority); tlv_trace_uint32_hex( __PRETTY_FUNCTION__, "generation_id", ifp->name, src_addr, PIM_OPTION_IS_SET(hello_options, PIM_OPTION_MASK_GENERATION_ID), hello_option_generation_id); tlv_trace_list(__PRETTY_FUNCTION__, "address_list", ifp->name, src_addr, PIM_OPTION_IS_SET(hello_options, PIM_OPTION_MASK_ADDRESS_LIST), hello_option_addr_list); } if (!PIM_OPTION_IS_SET(hello_options, PIM_OPTION_MASK_HOLDTIME)) { if (PIM_DEBUG_PIM_HELLO) { char src_str[INET_ADDRSTRLEN]; pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str)); zlog_debug( "%s: PIM hello missing holdtime from %s on interface %s", __PRETTY_FUNCTION__, src_str, ifp->name); } } /* New neighbor? */ neigh = pim_neighbor_find(ifp, src_addr); if (!neigh) { /* Add as new neighbor */ neigh = pim_neighbor_add( ifp, src_addr, hello_options, hello_option_holdtime, hello_option_propagation_delay, hello_option_override_interval, hello_option_dr_priority, hello_option_generation_id, hello_option_addr_list, PIM_NEIGHBOR_SEND_DELAY); if (!neigh) { if (PIM_DEBUG_PIM_HELLO) { char src_str[INET_ADDRSTRLEN]; pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str)); zlog_warn( "%s: failure creating PIM neighbor %s on interface %s", __PRETTY_FUNCTION__, src_str, ifp->name); } FREE_ADDR_LIST_THEN_RETURN(-8); } /* actual addr list has been saved under neighbor */ return 0; } /* Received generation ID ? */ if (PIM_OPTION_IS_SET(hello_options, PIM_OPTION_MASK_GENERATION_ID)) { /* GenID mismatch ? */ if (!PIM_OPTION_IS_SET(neigh->hello_options, PIM_OPTION_MASK_GENERATION_ID) || (hello_option_generation_id != neigh->generation_id)) { /* GenID mismatch, then replace neighbor */ if (PIM_DEBUG_PIM_HELLO) { char src_str[INET_ADDRSTRLEN]; pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str)); zlog_debug( "%s: GenId mismatch new=%08x old=%08x: replacing neighbor %s on %s", __PRETTY_FUNCTION__, hello_option_generation_id, neigh->generation_id, src_str, ifp->name); } pim_upstream_rpf_genid_changed(pim_ifp->pim, neigh->source_addr); pim_neighbor_delete(ifp, neigh, "GenID mismatch"); neigh = pim_neighbor_add(ifp, src_addr, hello_options, hello_option_holdtime, hello_option_propagation_delay, hello_option_override_interval, hello_option_dr_priority, hello_option_generation_id, hello_option_addr_list, PIM_NEIGHBOR_SEND_NOW); if (!neigh) { if (PIM_DEBUG_PIM_HELLO) { char src_str[INET_ADDRSTRLEN]; pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str)); zlog_debug( "%s: failure re-creating PIM neighbor %s on interface %s", __PRETTY_FUNCTION__, src_str, ifp->name); } FREE_ADDR_LIST_THEN_RETURN(-9); } /* actual addr list is saved under neighbor */ return 0; } /* GenId mismatch: replace neighbor */ } /* GenId received */ /* Update existing neighbor */ pim_neighbor_update(neigh, hello_options, hello_option_holdtime, hello_option_dr_priority, hello_option_addr_list); /* actual addr list is saved under neighbor */ return 0; }