Commit 1e8721e2 authored by Ondrej Zajicek (work)'s avatar Ondrej Zajicek (work)
Browse files

Babel: Parse flags in Hello TLV 

RFC6126bis introduces a flags field for the Hello TLV, and adds a unicast flag
that is used to signify that a hello was sent as unicast. This adds parsing of
the flags field and ignores such unicast hellos, which preserves compatibility
until we can add a proper implementation of the unicast hello mechanism.

Thanks to Toke Hoiland-Jorgensen for the patch.
parent 9ba4b4a6

proto/babel/packets.c

+14 −5
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ struct babel_tlv_ack { 
struct babel_tlv_hello {

  u8 type;

  u8 length;

  u16 reserved;

  u16 flags;

  u16 seqno;

  u16 interval;

} PACKED;
@@ -104,8 +104,12 @@ struct babel_tlv_seqno_request { 
} PACKED;





#define BABEL_FLAG_DEF_PREFIX	0x80

#define BABEL_FLAG_ROUTER_ID	0x40

/* Hello flags */

#define BABEL_HF_UNICAST	0x8000



/* Update flags */

#define BABEL_UF_DEF_PREFIX	0x80

#define BABEL_UF_ROUTER_ID	0x40





struct babel_parse_state {
@@ -310,6 +314,11 @@ babel_read_hello(struct babel_tlv *hdr, union babel_msg *m, 
  struct babel_tlv_hello *tlv = (void *) hdr;

  struct babel_msg_hello *msg = &m->hello;



  /* We currently don't support unicast Hello */

  u16 flags = get_u16(&tlv->flags);

  if (flags & BABEL_HF_UNICAST)

    return PARSE_IGNORE;



  msg->type = BABEL_TLV_HELLO;

  msg->seqno = get_u16(&tlv->seqno);

  msg->interval = get_time16(&tlv->interval);
@@ -500,13 +509,13 @@ babel_read_update(struct babel_tlv *hdr, union babel_msg *m, 
    msg->plen = tlv->plen;

    msg->prefix = ipa_from_ip6(get_ip6(buf));



    if (tlv->flags & BABEL_FLAG_DEF_PREFIX)

    if (tlv->flags & BABEL_UF_DEF_PREFIX)

    {

      put_ip6(state->def_ip6_prefix, msg->prefix);

      state->def_ip6_prefix_seen = 1;

    }



    if (tlv->flags & BABEL_FLAG_ROUTER_ID)

    if (tlv->flags & BABEL_UF_ROUTER_ID)

    {

      state->router_id = ((u64) _I2(msg->prefix)) << 32 | _I3(msg->prefix);

      state->router_id_seen = 1;

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