diff options
Diffstat (limited to 'pimd/pim_igmp.c')
| -rw-r--r-- | pimd/pim_igmp.c | 1411 |
1 files changed, 1411 insertions, 0 deletions
diff --git a/pimd/pim_igmp.c b/pimd/pim_igmp.c new file mode 100644 index 00000000..e38ac96a --- /dev/null +++ b/pimd/pim_igmp.c @@ -0,0 +1,1411 @@ +/* + PIM for Quagga + Copyright (C) 2008 Everton da Silva Marques + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; see the file COPYING; if not, write to the + Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, + MA 02110-1301 USA + + $QuaggaId: $Format:%an, %ai, %h$ $ +*/ + +#include <zebra.h> + +#include "memory.h" + +#include "pimd.h" +#include "pim_igmp.h" +#include "pim_igmpv3.h" +#include "pim_iface.h" +#include "pim_sock.h" +#include "pim_mroute.h" +#include "pim_str.h" +#include "pim_util.h" +#include "pim_time.h" +#include "pim_zebra.h" + +#define IGMP_GRP_REC_TYPE_MODE_IS_INCLUDE (1) +#define IGMP_GRP_REC_TYPE_MODE_IS_EXCLUDE (2) +#define IGMP_GRP_REC_TYPE_CHANGE_TO_INCLUDE_MODE (3) +#define IGMP_GRP_REC_TYPE_CHANGE_TO_EXCLUDE_MODE (4) +#define IGMP_GRP_REC_TYPE_ALLOW_NEW_SOURCES (5) +#define IGMP_GRP_REC_TYPE_BLOCK_OLD_SOURCES (6) + +static void group_timer_off(struct igmp_group *group); + +static struct igmp_group *find_group_by_addr(struct igmp_sock *igmp, + struct in_addr group_addr); + +static int igmp_sock_open(struct in_addr ifaddr, int ifindex, uint32_t pim_options) +{ + int fd; + int join = 0; + struct in_addr group; + + fd = pim_socket_mcast(IPPROTO_IGMP, ifaddr, 1 /* loop=true */); + if (fd < 0) + return -1; + + if (PIM_IF_TEST_IGMP_LISTEN_ALLROUTERS(pim_options)) { + if (inet_aton(PIM_ALL_ROUTERS, &group)) { + if (!pim_socket_join(fd, group, ifaddr, ifindex)) + ++join; + } + else { + zlog_warn("%s %s: IGMP socket fd=%d interface %s: could not solve %s to group address: errno=%d: %s", + __FILE__, __PRETTY_FUNCTION__, fd, inet_ntoa(ifaddr), + PIM_ALL_ROUTERS, errno, strerror(errno)); + } + } + + /* + IGMP routers periodically send IGMP general queries to AllSystems=224.0.0.1 + IGMP routers must receive general queries for querier election. + */ + if (inet_aton(PIM_ALL_SYSTEMS, &group)) { + if (!pim_socket_join(fd, group, ifaddr, ifindex)) + ++join; + } + else { + zlog_warn("%s %s: IGMP socket fd=%d interface %s: could not solve %s to group address: errno=%d: %s", + __FILE__, __PRETTY_FUNCTION__, fd, inet_ntoa(ifaddr), + PIM_ALL_SYSTEMS, errno, strerror(errno)); + } + + if (inet_aton(PIM_ALL_IGMP_ROUTERS, &group)) { + if (!pim_socket_join(fd, group, ifaddr, ifindex)) { + ++join; + } + } + else { + zlog_warn("%s %s: IGMP socket fd=%d interface %s: could not solve %s to group address: errno=%d: %s", + __FILE__, __PRETTY_FUNCTION__, fd, inet_ntoa(ifaddr), + PIM_ALL_IGMP_ROUTERS, errno, strerror(errno)); + } + + if (!join) { + zlog_err("IGMP socket fd=%d could not join any group on interface address %s", + fd, inet_ntoa(ifaddr)); + close(fd); + fd = -1; + } + + return fd; +} + +#undef IGMP_SOCK_DUMP + +#ifdef IGMP_SOCK_DUMP +static void igmp_sock_dump(array_t *igmp_sock_array) +{ + int size = array_size(igmp_sock_array); + for (int i = 0; i < size; ++i) { + + struct igmp_sock *igmp = array_get(igmp_sock_array, i); + + zlog_debug("%s %s: [%d/%d] igmp_addr=%s fd=%d", + __FILE__, __PRETTY_FUNCTION__, + i, size, + inet_ntoa(igmp->ifaddr), + igmp->fd); + } +} +#endif + +struct igmp_sock *pim_igmp_sock_lookup_ifaddr(struct list *igmp_sock_list, + struct in_addr ifaddr) +{ + struct listnode *sock_node; + struct igmp_sock *igmp; + +#ifdef IGMP_SOCK_DUMP + igmp_sock_dump(igmp_sock_list); +#endif + + for (ALL_LIST_ELEMENTS_RO(igmp_sock_list, sock_node, igmp)) + if (ifaddr.s_addr == igmp->ifaddr.s_addr) + return igmp; + + return 0; +} + +struct igmp_sock *igmp_sock_lookup_by_fd(struct list *igmp_sock_list, + int fd) +{ + struct listnode *sock_node; + struct igmp_sock *igmp; + + for (ALL_LIST_ELEMENTS_RO(igmp_sock_list, sock_node, igmp)) + if (fd == igmp->fd) + return igmp; + + return 0; +} + +static int pim_igmp_other_querier_expire(struct thread *t) +{ + struct igmp_sock *igmp; + + zassert(t); + igmp = THREAD_ARG(t); + zassert(igmp); + + zassert(igmp->t_other_querier_timer); + zassert(!igmp->t_igmp_query_timer); + + if (PIM_DEBUG_IGMP_TRACE) { + char ifaddr_str[100]; + pim_inet4_dump("<ifaddr?>", igmp->ifaddr, ifaddr_str, sizeof(ifaddr_str)); + zlog_debug("%s: Querier %s resuming", + __PRETTY_FUNCTION__, + ifaddr_str); + } + + igmp->t_other_querier_timer = 0; + + /* + We are the current querier, then + re-start sending general queries. + */ + pim_igmp_general_query_on(igmp); + + return 0; +} + +void pim_igmp_other_querier_timer_on(struct igmp_sock *igmp) +{ + long other_querier_present_interval_msec; + struct pim_interface *pim_ifp; + + zassert(igmp); + zassert(igmp->interface); + zassert(igmp->interface->info); + + pim_ifp = igmp->interface->info; + + if (igmp->t_other_querier_timer) { + /* + There is other querier present already, + then reset the other-querier-present timer. + */ + + if (PIM_DEBUG_IGMP_TRACE) { + char ifaddr_str[100]; + pim_inet4_dump("<ifaddr?>", igmp->ifaddr, ifaddr_str, sizeof(ifaddr_str)); + zlog_debug("Querier %s resetting TIMER event for Other-Querier-Present", + ifaddr_str); + } + + THREAD_OFF(igmp->t_other_querier_timer); + zassert(!igmp->t_other_querier_timer); + } + else { + /* + We are the current querier, then stop sending general queries: + igmp->t_igmp_query_timer = 0; + */ + pim_igmp_general_query_off(igmp); + } + + /* + Since this socket is starting the other-querier-present timer, + there should not be periodic query timer for this socket. + */ + zassert(!igmp->t_igmp_query_timer); + + /* + RFC 3376: 8.5. Other Querier Present Interval + + The Other Querier Present Interval is the length of time that must + pass before a multicast router decides that there is no longer + another multicast router which should be the querier. This value + MUST be ((the Robustness Variable) times (the Query Interval)) plus + (one half of one Query Response Interval). + + other_querier_present_interval_msec = \ + igmp->querier_robustness_variable * \ + 1000 * igmp->querier_query_interval + \ + 100 * (pim_ifp->query_max_response_time_dsec >> 1); + */ + other_querier_present_interval_msec = + PIM_IGMP_OQPI_MSEC(igmp->querier_robustness_variable, + igmp->querier_query_interval, + pim_ifp->igmp_query_max_response_time_dsec); + + if (PIM_DEBUG_IGMP_TRACE) { + char ifaddr_str[100]; + pim_inet4_dump("<ifaddr?>", igmp->ifaddr, ifaddr_str, sizeof(ifaddr_str)); + zlog_debug("Querier %s scheduling %ld.%03ld sec TIMER event for Other-Querier-Present", + ifaddr_str, + other_querier_present_interval_msec / 1000, + other_querier_present_interval_msec % 1000); + } + + THREAD_TIMER_MSEC_ON(master, igmp->t_other_querier_timer, + pim_igmp_other_querier_expire, + igmp, other_querier_present_interval_msec); +} + +void pim_igmp_other_querier_timer_off(struct igmp_sock *igmp) +{ + zassert(igmp); + + if (PIM_DEBUG_IGMP_TRACE) { + if (igmp->t_other_querier_timer) { + char ifaddr_str[100]; + pim_inet4_dump("<ifaddr?>", igmp->ifaddr, ifaddr_str, sizeof(ifaddr_str)); + zlog_debug("IGMP querier %s fd=%d cancelling other-querier-present TIMER event on %s", + ifaddr_str, igmp->fd, igmp->interface->name); + } + } + THREAD_OFF(igmp->t_other_querier_timer); + zassert(!igmp->t_other_querier_timer); +} + +static int recv_igmp_query(struct igmp_sock *igmp, int query_version, + int max_resp_code, + struct in_addr from, const char *from_str, + char *igmp_msg, int igmp_msg_len) +{ + struct interface *ifp; + struct pim_interface *pim_ifp; + uint8_t resv_s_qrv; + uint8_t s_flag; + uint8_t qrv; + struct in_addr group_addr; + uint16_t recv_checksum; + uint16_t checksum; + + group_addr = *(struct in_addr *)(igmp_msg + 4); + + ifp = igmp->interface; + pim_ifp = ifp->info; + + recv_checksum = *(uint16_t *) (igmp_msg + IGMP_V3_CHECKSUM_OFFSET); + + /* for computing checksum */ + *(uint16_t *) (igmp_msg + IGMP_V3_CHECKSUM_OFFSET) = 0; + + checksum = pim_inet_checksum(igmp_msg, igmp_msg_len); + if (checksum != recv_checksum) { + zlog_warn("Recv IGMP query v%d from %s on %s: checksum mismatch: received=%x computed=%x", + query_version, from_str, ifp->name, recv_checksum, checksum); + return -1; + } + + if (PIM_DEBUG_IGMP_PACKETS) { + char group_str[100]; + pim_inet4_dump("<group?>", group_addr, group_str, sizeof(group_str)); + zlog_debug("Recv IGMP query v%d from %s on %s: size=%d checksum=%x group=%s", + query_version, from_str, ifp->name, + igmp_msg_len, checksum, group_str); + } + + /* + RFC 3376: 6.6.2. Querier Election + + When a router receives a query with a lower IP address, it sets + the Other-Querier-Present timer to Other Querier Present Interval + and ceases to send queries on the network if it was the previously + elected querier. + */ + if (ntohl(from.s_addr) < ntohl(igmp->ifaddr.s_addr)) { + + if (PIM_DEBUG_IGMP_TRACE) { + char ifaddr_str[100]; + pim_inet4_dump("<ifaddr?>", igmp->ifaddr, ifaddr_str, sizeof(ifaddr_str)); + zlog_debug("%s: local address %s (%u) lost querier election to %s (%u)", + ifp->name, + ifaddr_str, ntohl(igmp->ifaddr.s_addr), + from_str, ntohl(from.s_addr)); + } + + pim_igmp_other_querier_timer_on(igmp); + } + + /* + RFC 3376: 4.1.6. QRV (Querier's Robustness Variable) + + Routers adopt the QRV value from the most recently received Query + as their own [Robustness Variable] value, unless that most + recently received QRV was zero, in which case the receivers use + the default [Robustness Variable] value specified in section 8.1 + or a statically configured value. + */ + resv_s_qrv = igmp_msg[8]; + qrv = 7 & resv_s_qrv; + igmp->querier_robustness_variable = qrv ? qrv : pim_ifp->igmp_default_robustness_variable; + + /* + RFC 3376: 4.1.7. QQIC (Querier's Query Interval Code) + + Multicast routers that are not the current querier adopt the QQI + value from the most recently received Query as their own [Query + Interval] value, unless that most recently received QQI was zero, + in which case the receiving routers use the default. + */ + if (igmp->t_other_querier_timer) { + /* other querier present */ + uint8_t qqic; + uint16_t qqi; + qqic = igmp_msg[9]; + qqi = igmp_msg_decode8to16(qqic); + igmp->querier_query_interval = qqi ? qqi : pim_ifp->igmp_default_query_interval; + + if (PIM_DEBUG_IGMP_TRACE) { + char ifaddr_str[100]; + pim_inet4_dump("<ifaddr?>", igmp->ifaddr, ifaddr_str, sizeof(ifaddr_str)); + zlog_debug("Querier %s new query interval is %s QQI=%u sec (recv QQIC=%02x from %s)", + ifaddr_str, + qqi ? "recv-non-default" : "default", + igmp->querier_query_interval, + qqic, + from_str); + } + } + + /* + RFC 3376: 6.6.1. Timer Updates + + When a router sends or receives a query with a clear Suppress + Router-Side Processing flag, it must update its timers to reflect + the correct timeout values for the group or sources being queried. + + General queries don't trigger timer update. + */ + s_flag = (1 << 3) & resv_s_qrv; + if (!s_flag) { + /* s_flag is clear */ + + if (PIM_INADDR_IS_ANY(group_addr)) { + /* this is a general query */ + + /* log that general query should have the s_flag set */ + zlog_warn("General IGMP query v%d from %s on %s: Router-Side Processing flag is clear", + query_version, from_str, ifp->name); + } + else { + struct igmp_group *group; + + /* this is a non-general query: perform timer updates */ + + group = find_group_by_addr(igmp, group_addr); + if (group) { + int recv_num_sources = ntohs(*(uint16_t *)(igmp_msg + IGMP_V3_NUMSOURCES_OFFSET)); + + /* + RFC 3376: 6.6.1. Timer Updates + Query Q(G,A): Source Timer for sources in A are lowered to LMQT + Query Q(G): Group Timer is lowered to LMQT + */ + if (recv_num_sources < 1) { + /* Query Q(G): Group Timer is lowered to LMQT */ + + igmp_group_timer_lower_to_lmqt(group); + } + else { + /* Query Q(G,A): Source Timer for sources in A are lowered to LMQT */ + + /* Scan sources in query and lower their timers to LMQT */ + struct in_addr *sources = (struct in_addr *)(igmp_msg + IGMP_V3_SOURCES_OFFSET); + for (int i = 0; i < recv_num_sources; ++i) { + struct in_addr src_addr = sources[i]; + struct igmp_source *src = igmp_find_source_by_addr(group, src_addr); + if (src) { + igmp_source_timer_lower_to_lmqt(src); + } + } + } + + } + else { + char group_str[100]; + pim_inet4_dump("<group?>", group_addr, group_str, sizeof(group_str)); + zlog_warn("IGMP query v%d from %s on %s: could not find group %s for timer update", + query_version, from_str, ifp->name, group_str); + } + } + } /* s_flag is clear: timer updates */ + + return 0; +} + +static int igmp_v3_report(struct igmp_sock *igmp, + struct in_addr from, const char *from_str, + char *igmp_msg, int igmp_msg_len) +{ + uint16_t recv_checksum; + uint16_t checksum; + int num_groups; + uint8_t *group_record; + uint8_t *report_pastend = (uint8_t *) igmp_msg + igmp_msg_len; + struct interface *ifp = igmp->interface; + + if (igmp_msg_len < IGMP_V3_MSG_MIN_SIZE) { + zlog_warn("Recv IGMP report v3 from %s on %s: size=%d shorter than minimum=%d", + from_str, ifp->name, igmp_msg_len, IGMP_V3_MSG_MIN_SIZE); + return -1; + } + + recv_checksum = *(uint16_t *) (igmp_msg + IGMP_V3_CHECKSUM_OFFSET); + + /* for computing checksum */ + *(uint16_t *) (igmp_msg + IGMP_V3_CHECKSUM_OFFSET) = 0; + + checksum = pim_inet_checksum(igmp_msg, igmp_msg_len); + if (checksum != recv_checksum) { + zlog_warn("Recv IGMP report v3 from %s on %s: checksum mismatch: received=%x computed=%x", + from_str, ifp->name, recv_checksum, checksum); + return -1; + } + + num_groups = ntohs(*(uint16_t *) (igmp_msg + IGMP_V3_REPORT_NUMGROUPS_OFFSET)); + if (num_groups < 1) { + zlog_warn("Recv IGMP report v3 from %s on %s: missing group records", + from_str, ifp->name); + return -1; + } + + if (PIM_DEBUG_IGMP_PACKETS) { + zlog_debug("Recv IGMP report v3 from %s on %s: size=%d checksum=%x groups=%d", + from_str, ifp->name, igmp_msg_len, checksum, num_groups); + } + + group_record = (uint8_t *) igmp_msg + IGMP_V3_REPORT_GROUPPRECORD_OFFSET; + + /* Scan groups */ + for (int i = 0; i < num_groups; ++i) { + struct in_addr rec_group; + uint8_t *sources; + uint8_t *src; + int rec_type; + int rec_auxdatalen; + int rec_num_sources; + int j; + + if ((group_record + IGMP_V3_GROUP_RECORD_MIN_SIZE) > report_pastend) { + zlog_warn("Recv IGMP report v3 from %s on %s: group record beyond report end", + from_str, ifp->name); + return -1; + } + + rec_type = group_record[IGMP_V3_GROUP_RECORD_TYPE_OFFSET]; + rec_auxdatalen = group_record[IGMP_V3_GROUP_RECORD_AUXDATALEN_OFFSET]; + rec_num_sources = ntohs(* (uint16_t *) (group_record + IGMP_V3_GROUP_RECORD_NUMSOURCES_OFFSET)); + + rec_group = *(struct in_addr *)(group_record + IGMP_V3_GROUP_RECORD_GROUP_OFFSET); + + if (PIM_DEBUG_IGMP_PACKETS) { + zlog_debug("Recv IGMP report v3 from %s on %s: record=%d type=%d auxdatalen=%d sources=%d group=%s", + from_str, ifp->name, i, rec_type, rec_auxdatalen, rec_num_sources, inet_ntoa(rec_group)); + } + + /* Scan sources */ + + sources = group_record + IGMP_V3_GROUP_RECORD_SOURCE_OFFSET; + + for (j = 0, src = sources; j < rec_num_sources; ++j, src += 4) { + + if ((src + 4) > report_pastend) { + zlog_warn("Recv IGMP report v3 from %s on %s: group source beyond report end", + from_str, ifp->name); + return -1; + } + + if (PIM_DEBUG_IGMP_PACKETS) { + char src_str[200]; + + if (!inet_ntop(AF_INET, src, src_str , sizeof(src_str))) + sprintf(src_str, "<source?>"); + + zlog_debug("Recv IGMP report v3 from %s on %s: record=%d group=%s source=%s", + from_str, ifp->name, i, inet_ntoa(rec_group), src_str); + } + } /* for (sources) */ + + switch (rec_type) { + case IGMP_GRP_REC_TYPE_MODE_IS_INCLUDE: + igmpv3_report_isin(igmp, from, rec_group, rec_num_sources, (struct in_addr *) sources); + break; + case IGMP_GRP_REC_TYPE_MODE_IS_EXCLUDE: + igmpv3_report_isex(igmp, from, rec_group, rec_num_sources, (struct in_addr *) sources); + break; + case IGMP_GRP_REC_TYPE_CHANGE_TO_INCLUDE_MODE: + igmpv3_report_toin(igmp, from, rec_group, rec_num_sources, (struct in_addr *) sources); + break; + case IGMP_GRP_REC_TYPE_CHANGE_TO_EXCLUDE_MODE: + igmpv3_report_toex(igmp, from, rec_group, rec_num_sources, (struct in_addr *) sources); + break; + case IGMP_GRP_REC_TYPE_ALLOW_NEW_SOURCES: + igmpv3_report_allow(igmp, from, rec_group, rec_num_sources, (struct in_addr *) sources); + break; + case IGMP_GRP_REC_TYPE_BLOCK_OLD_SOURCES: + igmpv3_report_block(igmp, from, rec_group, rec_num_sources, (struct in_addr *) sources); + break; + default: + zlog_warn("Recv IGMP report v3 from %s on %s: unknown record type: type=%d", + from_str, ifp->name, rec_type); + } + + group_record += 8 + (rec_num_sources << 2) + (rec_auxdatalen << 2); + + } /* for (group records) */ + + return 0; +} + +static void on_trace(const char *label, + struct interface *ifp, struct in_addr from) +{ + if (PIM_DEBUG_IGMP_TRACE) { + char from_str[100]; + pim_inet4_dump("<from?>", from, from_str, sizeof(from_str)); + zlog_debug("%s: from %s on %s", + label, from_str, ifp->name); + } +} + +static int igmp_v2_report(struct igmp_sock *igmp, + struct in_addr from, const char *from_str, + char *igmp_msg, int igmp_msg_len) +{ + struct interface *ifp = igmp->interface; + struct igmp_group *group; + struct in_addr group_addr; + + on_trace(__PRETTY_FUNCTION__, igmp->interface, from); + + if (igmp_msg_len != IGMP_V12_MSG_SIZE) { + zlog_warn("Recv IGMP report v2 from %s on %s: size=%d other than correct=%d", + from_str, ifp->name, igmp_msg_len, IGMP_V12_MSG_SIZE); + return -1; + } + + if (PIM_DEBUG_IGMP_TRACE) { + zlog_warn("%s %s: FIXME WRITEME", + __FILE__, __PRETTY_FUNCTION__); + } + + group_addr = *(struct in_addr *)(igmp_msg + 4); + + /* non-existant group is created as INCLUDE {empty} */ + group = igmp_add_group_by_addr(igmp, group_addr, ifp->name); + if (!group) { + return -1; + } + + group->last_igmp_v2_report_dsec = pim_time_monotonic_dsec(); + + return 0; +} + +static int igmp_v2_leave(struct igmp_sock *igmp, + struct in_addr from, const char *from_str, + char *igmp_msg, int igmp_msg_len) +{ + struct interface *ifp = igmp->interface; + + on_trace(__PRETTY_FUNCTION__, igmp->interface, from); + + if (igmp_msg_len != IGMP_V12_MSG_SIZE) { + zlog_warn("Recv IGMP leave v2 from %s on %s: size=%d other than correct=%d", + from_str, ifp->name, igmp_msg_len, IGMP_V12_MSG_SIZE); + return -1; + } + + if (PIM_DEBUG_IGMP_TRACE) { + zlog_warn("%s %s: FIXME WRITEME", + __FILE__, __PRETTY_FUNCTION__); + } + + return 0; +} + +static int igmp_v1_report(struct igmp_sock *igmp, + struct in_addr from, const char *from_str, + char *igmp_msg, int igmp_msg_len) +{ + struct interface *ifp = igmp->interface; + struct igmp_group *group; + struct in_addr group_addr; + + on_trace(__PRETTY_FUNCTION__, igmp->interface, from); + + if (igmp_msg_len != IGMP_V12_MSG_SIZE) { + zlog_warn("Recv IGMP report v1 from %s on %s: size=%d other than correct=%d", + from_str, ifp->name, igmp_msg_len, IGMP_V12_MSG_SIZE); + return -1; + } + + if (PIM_DEBUG_IGMP_TRACE) { + zlog_warn("%s %s: FIXME WRITEME", + __FILE__, __PRETTY_FUNCTION__); + } + + group_addr = *(struct in_addr *)(igmp_msg + 4); + + /* non-existant group is created as INCLUDE {empty} */ + group = igmp_add_group_by_addr(igmp, group_addr, ifp->name); + if (!group) { + return -1; + } + + group->last_igmp_v1_report_dsec = pim_time_monotonic_dsec(); + + return 0; +} + +int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len) +{ + struct ip *ip_hdr; + size_t ip_hlen; /* ip header length in bytes */ + char *igmp_msg; + int igmp_msg_len; + int msg_type; + char from_str[100]; + char to_str[100]; + + if (len < sizeof(*ip_hdr)) { + zlog_warn("IGMP packet size=%d shorter than minimum=%d", + len, sizeof(*ip_hdr)); + return -1; + } + + ip_hdr = (struct ip *) buf; + + pim_inet4_dump("<src?>", ip_hdr->ip_src, from_str , sizeof(from_str)); + pim_inet4_dump("<dst?>", ip_hdr->ip_dst, to_str , sizeof(to_str)); + + ip_hlen = ip_hdr->ip_hl << 2; /* ip_hl gives length in 4-byte words */ + + if (PIM_DEBUG_IGMP_PACKETS) { + zlog_debug("Recv IP packet from %s to %s on %s: size=%d ip_header_size=%d ip_proto=%d", + from_str, to_str, igmp->interface->name, len, ip_hlen, ip_hdr->ip_p); + } + + if (ip_hdr->ip_p != PIM_IP_PROTO_IGMP) { + zlog_warn("IP packet protocol=%d is not IGMP=%d", + ip_hdr->ip_p, PIM_IP_PROTO_IGMP); + return -1; + } + + if (ip_hlen < PIM_IP_HEADER_MIN_LEN) { + zlog_warn("IP packet header size=%d 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=%d greater than maximum=%d", + ip_hlen, PIM_IP_HEADER_MAX_LEN); + return -1; + } + + igmp_msg = buf + ip_hlen; + msg_type = *igmp_msg; + igmp_msg_len = len - ip_hlen; + + if (PIM_DEBUG_IGMP_PACKETS) { + zlog_debug("Recv IGMP packet from %s to %s on %s: ttl=%d msg_type=%d msg_size=%d", + from_str, to_str, igmp->interface->name, ip_hdr->ip_ttl, msg_type, + igmp_msg_len); + } + + if (igmp_msg_len < PIM_IGMP_MIN_LEN) { + zlog_warn("IGMP message size=%d shorter than minimum=%d", + igmp_msg_len, PIM_IGMP_MIN_LEN); + return -1; + } + + switch (msg_type) { + case PIM_IGMP_MEMBERSHIP_QUERY: + { + int max_resp_code = igmp_msg[1]; + int query_version; + + /* + RFC 3376: 7.1. Query Version Distinctions + IGMPv1 Query: length = 8 octets AND Max Resp Code field is zero + IGMPv2 Query: length = 8 octets AND Max Resp Code field is non-zero + IGMPv3 Query: length >= 12 octets + */ + + if (igmp_msg_len == 8) { + query_version = max_resp_code ? 2 : 1; + } + else if (igmp_msg_len >= 12) { + query_version = 3; + } + else { + zlog_warn("Unknown IGMP query version"); + return -1; + } + + return recv_igmp_query(igmp, query_version, max_resp_code, + ip_hdr->ip_src, from_str, + igmp_msg, igmp_msg_len); + } + + case PIM_IGMP_V3_MEMBERSHIP_REPORT: + return igmp_v3_report(igmp, ip_hdr->ip_src, from_str, + igmp_msg, igmp_msg_len); + + case PIM_IGMP_V2_MEMBERSHIP_REPORT: + return igmp_v2_report(igmp, ip_hdr->ip_src, from_str, + igmp_msg, igmp_msg_len); + + case PIM_IGMP_V1_MEMBERSHIP_REPORT: + return igmp_v1_report(igmp, ip_hdr->ip_src, from_str, + igmp_msg, igmp_msg_len); + + case PIM_IGMP_V2_LEAVE_GROUP: + return igmp_v2_leave(igmp, ip_hdr->ip_src, from_str, + igmp_msg, igmp_msg_len); + } + + zlog_warn("Ignoring unsupported IGMP message type: %d", msg_type); + + return -1; +} + +static int pim_igmp_general_query(struct thread *t); + +void pim_igmp_general_query_on(struct igmp_sock *igmp) +{ + struct pim_interface *pim_ifp; + int startup_mode; + int query_interval; + + zassert(igmp); + zassert(igmp->interface); + + /* + Since this socket is starting as querier, + there should not exist a timer for other-querier-present. + */ + zassert(!igmp->t_other_querier_timer); + pim_ifp = igmp->interface->info; + zassert(pim_ifp); + + /* + RFC 3376: 8.6. Startup Query Interval + + The Startup Query Interval is the interval between General Queries + sent by a Querier on startup. Default: 1/4 the Query Interval. + */ + startup_mode = igmp->startup_query_count > 0; + if (startup_mode) { + --igmp->startup_query_count; + + /* query_interval = pim_ifp->igmp_default_query_interval >> 2; */ + query_interval = PIM_IGMP_SQI(pim_ifp->igmp_default_query_interval); + } + else { + query_interval = igmp->querier_query_interval; + } + + if (PIM_DEBUG_IGMP_TRACE) { + char ifaddr_str[100]; + pim_inet4_dump("<ifaddr?>", igmp->ifaddr, ifaddr_str, sizeof(ifaddr_str)); + zlog_debug("Querier %s scheduling %d-second (%s) TIMER event for IGMP query on fd=%d", + ifaddr_str, + query_interval, + startup_mode ? "startup" : "non-startup", + igmp->fd); + } + igmp->t_igmp_query_timer = 0; + zassert(!igmp->t_igmp_query_timer); + THREAD_TIMER_ON(master, igmp->t_igmp_query_timer, + pim_igmp_general_query, + igmp, query_interval); +} + +void pim_igmp_general_query_off(struct igmp_sock *igmp) +{ + zassert(igmp); + + if (PIM_DEBUG_IGMP_TRACE) { + if (igmp->t_igmp_query_timer) { + char ifaddr_str[100]; + pim_inet4_dump("<ifaddr?>", igmp->ifaddr, ifaddr_str, sizeof(ifaddr_str)); + zlog_debug("IGMP querier %s fd=%d cancelling query TIMER event on %s", + ifaddr_str, igmp->fd, igmp->interface->name); + } + } + THREAD_OFF(igmp->t_igmp_query_timer); + zassert(!igmp->t_igmp_query_timer); +} + +/* Issue IGMP general query */ +static int pim_igmp_general_query(struct thread *t) +{ + char query_buf[PIM_IGMP_BUFSIZE_WRITE]; + struct igmp_sock *igmp; + struct in_addr dst_addr; + struct in_addr group_addr; + struct pim_interface *pim_ifp; + + zassert(t); + + igmp = THREAD_ARG(t); + + zassert(igmp); + zassert(igmp->interface); + zassert(igmp->interface->info); + + pim_ifp = igmp->interface->info; + + /* + RFC3376: 4.1.12. IP Destination Addresses for Queries + + In IGMPv3, General Queries are sent with an IP destination address + of 224.0.0.1, the all-systems multicast address. Group-Specific + and Group-and-Source-Specific Queries are sent with an IP + destination address equal to the multicast address of interest. + */ + + dst_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); + group_addr.s_addr = PIM_NET_INADDR_ANY; + + if (PIM_DEBUG_IGMP_TRACE) { + char querier_str[100]; + char dst_str[100]; + pim_inet4_dump("<querier?>", igmp->ifaddr, querier_str, + sizeof(querier_str)); + pim_inet4_dump("<dst?>", dst_addr, dst_str, sizeof(dst_str)); + zlog_debug("Querier %s issuing IGMP general query to %s on %s", + querier_str, dst_str, igmp->interface->name); + } + + pim_igmp_send_membership_query(0 /* igmp_group */, + igmp->fd, + igmp->interface->name, + query_buf, + sizeof(query_buf), + 0 /* num_sources */, + dst_addr, + group_addr, + pim_ifp->igmp_query_max_response_time_dsec, + 1 /* s_flag: always set for general queries */, + igmp->querier_robustness_variable, + igmp->querier_query_interval); + + pim_igmp_general_query_on(igmp); + + return 0; +} + +static int pim_igmp_read(struct thread *t); + +static void igmp_read_on(struct igmp_sock *igmp) +{ + zassert(igmp); + + if (PIM_DEBUG_IGMP_TRACE) { + zlog_debug("Scheduling READ event on IGMP socket fd=%d", + igmp->fd); + } + igmp->t_igmp_read = 0; + zassert(!igmp->t_igmp_read); + THREAD_READ_ON(master, igmp->t_igmp_read, pim_igmp_read, igmp, igmp->fd); +} + +static int pim_igmp_read(struct thread *t) +{ + struct igmp_sock *igmp; + int fd; + struct sockaddr_in from; + struct sockaddr_in to; + socklen_t fromlen = sizeof(from); + socklen_t tolen = sizeof(to); + char buf[PIM_IGMP_BUFSIZE_READ]; + int len; + int ifindex = -1; + int result = -1; /* defaults to bad */ + + zassert(t); + + igmp = THREAD_ARG(t); + + zassert(igmp); + + fd = THREAD_FD(t); + + zassert(fd == igmp->fd); + + len = pim_socket_recvfromto(fd, buf, sizeof(buf), + &from, &fromlen, + &to, &tolen, + &ifindex); + if (len < 0) { + zlog_warn("Failure receiving IP IGMP packet on fd=%d: errno=%d: %s", + fd, errno, strerror(errno)); + goto done; + } + + if (PIM_DEBUG_IGMP_PACKETS) { + char from_str[100]; + char to_str[100]; + + if (!inet_ntop(AF_INET, &from.sin_addr, from_str, sizeof(from_str))) + sprintf(from_str, "<from?>"); + if (!inet_ntop(AF_INET, &to.sin_addr, to_str, sizeof(to_str))) + sprintf(to_str, "<to?>"); + + zlog_debug("Recv IP IGMP pkt size=%d from %s to %s on fd=%d on ifindex=%d (sock_ifindex=%d)", + len, from_str, to_str, fd, ifindex, igmp->interface->ifindex); + } + +#ifdef PIM_CHECK_RECV_IFINDEX_SANITY + /* ifindex sanity check */ + if (ifindex != (int) igmp->interface->ifindex) { + char from_str[100]; + char to_str[100]; + struct interface *ifp; + + if (!inet_ntop(AF_INET, &from.sin_addr, from_str , sizeof(from_str))) + sprintf(from_str, "<from?>"); + if (!inet_ntop(AF_INET, &to.sin_addr, to_str , sizeof(to_str))) + sprintf(to_str, "<to?>"); + + ifp = if_lookup_by_index(ifindex); + if (ifp) { + zassert(ifindex == (int) ifp->ifindex); + } + +#ifdef PIM_REPORT_RECV_IFINDEX_MISMATCH + zlog_warn("Interface mismatch: recv IGMP pkt from %s to %s on fd=%d: recv_ifindex=%d (%s) sock_ifindex=%d (%s)", + from_str, to_str, fd, + ifindex, ifp ? ifp->name : "<if-notfound>", + igmp->interface->ifindex, igmp->interface->name); +#endif + goto done; + } +#endif + + if (pim_igmp_packet(igmp, buf, len)) { + goto done; + } + + result = 0; /* good */ + + done: + igmp_read_on(igmp); + + return result; +} + +static void sock_close(struct igmp_sock *igmp) +{ + pim_igmp_other_querier_timer_off(igmp); + pim_igmp_general_query_off(igmp); + + if (PIM_DEBUG_IGMP_TRACE) { + if (igmp->t_igmp_read) { + zlog_debug("Cancelling READ event on IGMP socket %s fd=%d on interface %s", + inet_ntoa(igmp->ifaddr), igmp->fd, + igmp->interface->name); + } + } + THREAD_OFF(igmp->t_igmp_read); + zassert(!igmp->t_igmp_read); + + if (close(igmp->fd)) { + zlog_err("Failure closing IGMP socket %s fd=%d on interface %s: errno=%d: %s", + inet_ntoa(igmp->ifaddr), igmp->fd, igmp->interface->name, + errno, strerror(errno)); + } + + if (PIM_DEBUG_IGMP_TRACE) { + zlog_debug("Deleted IGMP socket %s fd=%d on interface %s", + inet_ntoa(igmp->ifaddr), igmp->fd, igmp->interface->name); + } +} + +void igmp_startup_mode_on(struct igmp_sock *igmp) +{ + struct pim_interface *pim_ifp; + + pim_ifp = igmp->interface->info; + + /* + RFC 3376: 8.7. Startup Query Count + + The Startup Query Count is the number of Queries sent out on + startup, separated by the Startup Query Interval. Default: the + Robustness Variable. + */ + igmp->startup_query_count = igmp->querier_robustness_variable; + + /* + Since we're (re)starting, reset QQI to default Query Interval + */ + igmp->querier_query_interval = pim_ifp->igmp_default_query_interval; +} + +static void igmp_group_free(struct igmp_group *group) +{ + zassert(!group->t_group_query_retransmit_timer); + zassert(!group->t_group_timer); + zassert(group->group_source_list); + zassert(!listcount(group->group_source_list)); + + list_free(group->group_source_list); + + XFREE(MTYPE_PIM_IGMP_GROUP, group); +} + +static void igmp_group_delete(struct igmp_group *group) +{ + struct listnode *src_node; + struct listnode *src_nextnode; + struct igmp_source *src; + + if (PIM_DEBUG_IGMP_TRACE) { + char group_str[100]; + pim_inet4_dump("<group?>", group->group_addr, group_str, sizeof(group_str)); + zlog_debug("Deleting IGMP group %s from socket %d interface %s", + group_str, + group->group_igmp_sock->fd, + group->group_igmp_sock->interface->name); + } + + for (ALL_LIST_ELEMENTS(group->group_source_list, src_node, src_nextnode, src)) { + igmp_source_delete(src); + } + + if (group->t_group_query_retransmit_timer) { + THREAD_OFF(group->t_group_query_retransmit_timer); + zassert(!group->t_group_query_retransmit_timer); + } + + group_timer_off(group); + listnode_delete(group->group_igmp_sock->igmp_group_list, group); + igmp_group_free(group); +} + +void igmp_group_delete_empty_include(struct igmp_group *group) +{ + zassert(!group->group_filtermode_isexcl); + zassert(!listcount(group->group_source_list)); + + igmp_group_delete(group); +} + +void igmp_sock_free(struct igmp_sock *igmp) +{ + zassert(!igmp->t_igmp_read); + zassert(!igmp->t_igmp_query_timer); + zassert(!igmp->t_other_querier_timer); + zassert(igmp->igmp_group_list); + zassert(!listcount(igmp->igmp_group_list)); + + list_free(igmp->igmp_group_list); + + XFREE(MTYPE_PIM_IGMP_SOCKET, igmp); +} + +void igmp_sock_delete(struct igmp_sock *igmp) +{ + struct pim_interface *pim_ifp; + struct listnode *grp_node; + struct listnode *grp_nextnode; + struct igmp_group *grp; + + for (ALL_LIST_ELEMENTS(igmp->igmp_group_list, grp_node, grp_nextnode, grp)) { + igmp_group_delete(grp); + } + + sock_close(igmp); + + pim_ifp = igmp->interface->info; + + listnode_delete(pim_ifp->igmp_socket_list, igmp); + + igmp_sock_free(igmp); +} + +static struct igmp_sock *igmp_sock_new(int fd, + struct in_addr ifaddr, + struct interface *ifp) +{ + struct pim_interface *pim_ifp; + struct igmp_sock *igmp; + + pim_ifp = ifp->info; + + if (PIM_DEBUG_IGMP_TRACE) { + zlog_debug("Creating IGMP socket fd=%d for address %s on interface %s", + fd, inet_ntoa(ifaddr), ifp->name); + } + + igmp = XMALLOC(MTYPE_PIM_IGMP_SOCKET, sizeof(*igmp)); + if (!igmp) { + zlog_warn("%s %s: XMALLOC() failure", + __FILE__, __PRETTY_FUNCTION__); + return 0; + } + + igmp->igmp_group_list = list_new(); + if (!igmp->igmp_group_list) { + zlog_err("%s %s: failure: igmp_group_list = list_new()", + __FILE__, __PRETTY_FUNCTION__); + return 0; + } + igmp->igmp_group_list->del = (void (*)(void *)) igmp_group_free; + + igmp->fd = fd; + igmp->interface = ifp; + igmp->ifaddr = ifaddr; + igmp->t_igmp_read = 0; + igmp->t_igmp_query_timer = 0; + igmp->t_other_querier_timer = 0; /* no other querier present */ + igmp->querier_robustness_variable = pim_ifp->igmp_default_robustness_variable; + igmp->sock_creation = pim_time_monotonic_sec(); + + /* + igmp_startup_mode_on() will reset QQI: + + igmp->querier_query_interval = pim_ifp->igmp_default_query_interval; + */ + igmp_startup_mode_on(igmp); + + igmp_read_on(igmp); + pim_igmp_general_query_on(igmp); + + return igmp; +} + +struct igmp_sock *pim_igmp_sock_add(struct list *igmp_sock_list, + struct in_addr ifaddr, + struct interface *ifp) +{ + struct pim_interface *pim_ifp; + struct igmp_sock *igmp; + int fd; + + pim_ifp = ifp->info; + + fd = igmp_sock_open(ifaddr, ifp->ifindex, pim_ifp->options); + if (fd < 0) { + zlog_warn("Could not open IGMP socket for %s on %s", + inet_ntoa(ifaddr), ifp->name); + return 0; + } + + igmp = igmp_sock_new(fd, ifaddr, ifp); + if (!igmp) { + zlog_err("%s %s: igmp_sock_new() failure", + __FILE__, __PRETTY_FUNCTION__); + close(fd); + return 0; + } + + listnode_add(igmp_sock_list, igmp); + +#ifdef IGMP_SOCK_DUMP + igmp_sock_dump(igmp_sock_array); +#endif + + return igmp; +} + +/* + RFC 3376: 6.5. Switching Router Filter-Modes + + When a router's filter-mode for a group is EXCLUDE and the group + timer expires, the router filter-mode for the group transitions to + INCLUDE. + + A router uses source records with running source timers as its state + for the switch to a filter-mode of INCLUDE. If there are any source + records with source timers greater than zero (i.e., requested to be + forwarded), a router switches to filter-mode of INCLUDE using those + source records. Source records whose timers are zero (from the + previous EXCLUDE mode) are deleted. + */ +static int igmp_group_timer(struct thread *t) +{ + struct igmp_group *group; + + zassert(t); + group = THREAD_ARG(t); + zassert(group); + + if (PIM_DEBUG_IGMP_TRACE) { + char group_str[100]; + pim_inet4_dump("<group?>", group->group_addr, group_str, sizeof(group_str)); + zlog_debug("%s: Timer for group %s on interface %s", + __PRETTY_FUNCTION__, + group_str, group->group_igmp_sock->interface->name); + } + + zassert(group->group_filtermode_isexcl); + + group->t_group_timer = 0; + group->group_filtermode_isexcl = 0; + + /* Any source (*,G) is forwarded only if mode is EXCLUDE {empty} */ + igmp_anysource_forward_stop(group); + + igmp_source_delete_expired(group->group_source_list); + + zassert(!group->t_group_timer); + zassert(!group->group_filtermode_isexcl); + + /* + RFC 3376: 6.2.2. Definition of Group Timers + + If there are no more source records for the group, delete group + record. + */ + if (listcount(group->group_source_list) < 1) { + igmp_group_delete_empty_include(group); + } + + return 0; +} + +static void group_timer_off(struct igmp_group *group) +{ + if (!group->t_group_timer) + return; + + if (PIM_DEBUG_IGMP_TRACE) { + char group_str[100]; + pim_inet4_dump("<group?>", group->group_addr, group_str, sizeof(group_str)); + zlog_debug("Cancelling TIMER event for group %s on %s", + group_str, group->group_igmp_sock->interface->name); + } + + THREAD_OFF(group->t_group_timer); + zassert(!group->t_group_timer); +} + +void igmp_group_timer_on(struct igmp_group *group, + long interval_msec, const char *ifname) +{ + group_timer_off(group); + + if (PIM_DEBUG_IGMP_EVENTS) { + char group_str[100]; + pim_inet4_dump("<group?>", group->group_addr, group_str, sizeof(group_str)); + zlog_debug("Scheduling %ld.%03ld sec TIMER event for group %s on %s", + interval_msec / 1000, + interval_msec % 1000, + group_str, ifname); + } + + /* + RFC 3376: 6.2.2. Definition of Group Timers + + The group timer is only used when a group is in EXCLUDE mode and + it represents the time for the *filter-mode* of the group to + expire and switch to INCLUDE mode. + */ + zassert(group->group_filtermode_isexcl); + + THREAD_TIMER_MSEC_ON(master, group->t_group_timer, + igmp_group_timer, + group, interval_msec); +} + +static struct igmp_group *find_group_by_addr(struct igmp_sock *igmp, + struct in_addr group_addr) +{ + struct igmp_group *group; + struct listnode *node; + + for (ALL_LIST_ELEMENTS_RO(igmp->igmp_group_list, node, group)) + if (group_addr.s_addr == group->group_addr.s_addr) + return group; + + return 0; +} + +struct igmp_group *igmp_add_group_by_addr(struct igmp_sock *igmp, + struct in_addr group_addr, + const char *ifname) +{ + struct igmp_group *group; + + group = find_group_by_addr(igmp, group_addr); + if (group) { + return group; + } + + /* + Non-existant group is created as INCLUDE {empty}: + + RFC 3376 - 5.1. Action on Change of Interface State + + If no interface state existed for that multicast address before + the change (i.e., the change consisted of creating a new + per-interface record), or if no state exists after the change + (i.e., the change consisted of deleting a per-interface record), + then the "non-existent" state is considered to have a filter mode + of INCLUDE and an empty source list. + */ + + group = XMALLOC(MTYPE_PIM_IGMP_GROUP, sizeof(*group)); + if (!group) { + zlog_warn("%s %s: XMALLOC() failure", + __FILE__, __PRETTY_FUNCTION__); + return 0; /* error, not found, could not create */ + } + + group->group_source_list = list_new(); + if (!group->group_source_list) { + zlog_warn("%s %s: list_new() failure", + __FILE__, __PRETTY_FUNCTION__); + XFREE(MTYPE_PIM_IGMP_GROUP, group); /* discard group */ + return 0; /* error, not found, could not initialize */ + } + group->group_source_list->del = (void (*)(void *)) igmp_source_free; + + group->t_group_timer = 0; + group->t_group_query_retransmit_timer = 0; + group->group_specific_query_retransmit_count = 0; + group->group_addr = group_addr; + group->group_igmp_sock = igmp; + group->last_igmp_v1_report_dsec = -1; + group->last_igmp_v2_report_dsec = -1; + group->group_creation = pim_time_monotonic_sec(); + + /* initialize new group as INCLUDE {empty} */ + group->group_filtermode_isexcl = 0; /* 0=INCLUDE, 1=EXCLUDE */ + + listnode_add(igmp->igmp_group_list, group); + + if (PIM_DEBUG_IGMP_TRACE) { + char group_str[100]; + pim_inet4_dump("<group?>", group->group_addr, group_str, sizeof(group_str)); + zlog_debug("Creating new IGMP group %s on socket %d interface %s", + group_str, group->group_igmp_sock->fd, ifname); + } + + /* + RFC 3376: 6.2.2. Definition of Group Timers + + The group timer is only used when a group is in EXCLUDE mode and + it represents the time for the *filter-mode* of the group to + expire and switch to INCLUDE mode. + */ + zassert(!group->group_filtermode_isexcl); /* INCLUDE mode */ + zassert(!group->t_group_timer); /* group timer == 0 */ + + /* Any source (*,G) is forwarded only if mode is EXCLUDE {empty} */ + igmp_anysource_forward_stop(group); + + return group; +} |