diff options
Diffstat (limited to 'babeld')
| -rw-r--r-- | babeld/message.c | 84 |
1 files changed, 63 insertions, 21 deletions
diff --git a/babeld/message.c b/babeld/message.c index 0ddfda8d7..8d3ee6f34 100644 --- a/babeld/message.c +++ b/babeld/message.c @@ -398,27 +398,69 @@ parse_packet(const unsigned char *from, struct interface *ifp, format_address(from), ifp->name); /* Nothing right now */ } else if(type == MESSAGE_HELLO) { - unsigned short seqno, interval; - int changed; - unsigned int timestamp = 0; - DO_NTOHS(seqno, message + 4); - DO_NTOHS(interval, message + 6); - debugf(BABEL_DEBUG_COMMON,"Received hello %d (%d) from %s on %s.", - seqno, interval, - format_address(from), ifp->name); - changed = update_neighbour(neigh, seqno, interval); - update_neighbour_metric(neigh, changed); - if(interval > 0) - /* Multiply by 3/2 to allow hellos to expire. */ - schedule_neighbours_check(interval * 15, 0); - /* Sub-TLV handling. */ - if(len > 8) { - if(parse_hello_subtlv(message + 8, len - 6, ×tamp) > 0) { - neigh->hello_send_us = timestamp; - neigh->hello_rtt_receive_time = babel_now; - have_hello_rtt = 1; - } - } + unsigned short seqno, interval, flags; + int changed; + unsigned int timestamp = 0; + +#define BABEL_UNICAST_HELLO 0x8000 + DO_NTOHS(flags, message + 2); + + /* + * RFC 8966 4.6.5 + * All other bits MUST be sent as a 0 and silently + * ignored on reception + */ + if (CHECK_FLAG(flags, ~BABEL_UNICAST_HELLO)) { + debugf(BABEL_DEBUG_COMMON, + "Received Hello from %s on %s that does not have all 0's in the unused section of flags, ignoring", + format_address(from), ifp->name); + continue; + } + + /* + * RFC 8966 Appendix F + * TL;DR -> Please ignore Unicast hellos until FRR's + * BABEL is brought up to date + */ + if (CHECK_FLAG(flags, BABEL_UNICAST_HELLO)) { + debugf(BABEL_DEBUG_COMMON, + "Received Unicast Hello from %s on %s that FRR is not prepared to understand yet", + format_address(from), ifp->name); + continue; + } + + DO_NTOHS(seqno, message + 4); + DO_NTOHS(interval, message + 6); + debugf(BABEL_DEBUG_COMMON, + "Received hello %d (%d) from %s on %s.", seqno, interval, + format_address(from), ifp->name); + + /* + * RFC 8966 Appendix F + * TL;DR -> Please ignore any Hello packets with the interval + * field set to 0 + */ + if (interval == 0) { + debugf(BABEL_DEBUG_COMMON, + "Received hello from %s on %s should be ignored as that this version of FRR does not know how to properly handle interval == 0", + format_address(from), ifp->name); + continue; + } + + changed = update_neighbour(neigh, seqno, interval); + update_neighbour_metric(neigh, changed); + if (interval > 0) + /* Multiply by 3/2 to allow hellos to expire. */ + schedule_neighbours_check(interval * 15, 0); + /* Sub-TLV handling. */ + if (len > 8) { + if (parse_hello_subtlv(message + 8, len - 6, + ×tamp) > 0) { + neigh->hello_send_us = timestamp; + neigh->hello_rtt_receive_time = babel_now; + have_hello_rtt = 1; + } + } } else if(type == MESSAGE_IHU) { unsigned short txcost, interval; unsigned char address[16]; |