Commit 963b2c7c authored by Ondrej Zajicek (work)'s avatar Ondrej Zajicek (work)
Browse files

BGP: Use proper class in attribute error messages 

Most error messages in attribute processing are in rx/decode step and
these use L_REMOTE log class. But there are few that are in tx/export
step and these should use L_ERR log class.

Use tx-specific macro (REJECT()) in tx/export code and rename field
err_withdraw to err_reject in struct bgp_export_state to ensure that
appropriate error reporting macros are called in proper contexts.
parent 75d01ecc

proto/bgp/attrs.c

+12 −9
Original line number Diff line number Diff line
@@ -45,9 +45,9 @@ 
 *

 * export - Hook that validates and normalizes attribute during export phase.

 * Receives eattr, may modify it (e.g., sort community lists for canonical

 * representation), UNSET() it (e.g., skip empty lists), or WITHDRAW() it if

 * necessary. May assume that eattr has value valid w.r.t. its type, but may be

 * invalid w.r.t. BGP constraints. Optional.

 * representation), UNSET() it (e.g., skip empty lists), or REJECT() the route

 * if necessary. May assume that eattr has value valid w.r.t. its type, but may

 * be invalid w.r.t. BGP constraints. Optional.

 *

 * encode - Hook that converts internal representation to external one during

 * packet writing. Receives eattr and puts it in the buffer (including attribute
@@ -108,6 +108,9 @@ bgp_set_attr(ea_list **attrs, struct linpool *pool, uint code, uint flags, uintp 
#define UNSET(a) \

  ({ a->type = EAF_TYPE_UNDEF; return; })



#define REJECT(msg, args...) \

  ({ log(L_ERR "%s: " msg, s->proto->p.name, ## args); s->err_reject = 1; return; })



#define NEW_BGP		"Discarding %s attribute received from AS4-aware neighbor"

#define BAD_EBGP	"Discarding %s attribute received from EBGP neighbor"

#define BAD_LENGTH	"Malformed %s attribute - invalid length (%u)"
@@ -380,7 +383,7 @@ static void 
bgp_export_origin(struct bgp_export_state *s, eattr *a)

{

  if (a->u.data > 2)

    WITHDRAW(BAD_VALUE, "ORIGIN", a->u.data);

    REJECT(BAD_VALUE, "ORIGIN", a->u.data);

}



static void
@@ -902,20 +905,20 @@ bgp_export_mpls_label_stack(struct bgp_export_state *s, eattr *a) 


  /* Perhaps we should just ignore it? */

  if (!s->mpls)

    WITHDRAW("Unexpected MPLS stack");

    REJECT("Unexpected MPLS stack");



  /* Empty MPLS stack is not allowed */

  if (!lnum)

    WITHDRAW("Malformed MPLS stack - empty");

    REJECT("Malformed MPLS stack - empty");



  /* This is ugly, but we must ensure that labels fit into NLRI field */

  if ((24*lnum + (net_is_vpn(n) ? 64 : 0) + net_pxlen(n)) > 255)

    WITHDRAW("Malformed MPLS stack - too many labels (%u)", lnum);

    REJECT("Malformed MPLS stack - too many labels (%u)", lnum);



  for (uint i = 0; i < lnum; i++)

  {

    if (labels[i] > 0xfffff)

      WITHDRAW("Malformed MPLS stack - invalid label (%u)", labels[i]);

      REJECT("Malformed MPLS stack - invalid label (%u)", labels[i]);



    /* TODO: Check for special-purpose label values? */

  }
@@ -1196,7 +1199,7 @@ bgp_export_attrs(struct bgp_export_state *s, ea_list *attrs) 
  for (i = 0; i < count; i++)

    bgp_export_attr(s, &new->attrs[i], new);



  if (s->err_withdraw)

  if (s->err_reject)

    return NULL;



  return new;

proto/bgp/bgp.h

+1 −1
Original line number Diff line number Diff line
@@ -397,7 +397,7 @@ struct bgp_export_state { 
  int mpls;



  u32 attrs_seen[1];

  uint err_withdraw;

  uint err_reject;

  uint local_next_hop;

};

proto/bgp/packets.c

+8 −5
Original line number Diff line number Diff line
@@ -932,6 +932,9 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, uint len) 
#define WITHDRAW(msg, args...) \

  ({ REPORT(msg, ## args); s->err_withdraw = 1; return; })



#define REJECT(msg, args...)						\

  ({ log(L_ERR "%s: " msg, s->proto->p.name, ## args); s->err_reject = 1; return; })



#define BAD_AFI		"Unexpected AF <%u/%u> in UPDATE"

#define BAD_NEXT_HOP	"Invalid NEXT_HOP attribute"

#define NO_NEXT_HOP	"Missing NEXT_HOP attribute"
@@ -1126,7 +1129,7 @@ bgp_update_next_hop_ip(struct bgp_export_state *s, eattr *a, ea_list **to) 
  /* Check if next hop is valid */

  a = bgp_find_attr(*to, BA_NEXT_HOP);

  if (!a)

    WITHDRAW(NO_NEXT_HOP);

    REJECT(NO_NEXT_HOP);



  ip_addr *nh = (void *) a->u.ptr->data;

  ip_addr peer = s->proto->remote_ip;
@@ -1134,20 +1137,20 @@ bgp_update_next_hop_ip(struct bgp_export_state *s, eattr *a, ea_list **to) 


  /* Forbid zero next hop */

  if (ipa_zero2(nh[0]) && ((len != 32) || ipa_zero(nh[1])))

    WITHDRAW(BAD_NEXT_HOP " - zero address");

    REJECT(BAD_NEXT_HOP " - zero address");



  /* Forbid next hop equal to neighbor IP */

  if (ipa_equal(peer, nh[0]) || ((len == 32) && ipa_equal(peer, nh[1])))

    WITHDRAW(BAD_NEXT_HOP " - neighbor address %I", peer);

    REJECT(BAD_NEXT_HOP " - neighbor address %I", peer);



  /* Forbid next hop with non-matching AF */

  if ((ipa_is_ip4(nh[0]) != bgp_channel_is_ipv4(s->channel)) &&

      !s->channel->ext_next_hop)

    WITHDRAW(BAD_NEXT_HOP MISMATCHED_AF, nh[0], s->channel->desc->name);

    REJECT(BAD_NEXT_HOP MISMATCHED_AF, nh[0], s->channel->desc->name);



  /* Just check if MPLS stack */

  if (s->mpls && !bgp_find_attr(*to, BA_MPLS_LABEL_STACK))

    WITHDRAW(NO_LABEL_STACK);

    REJECT(NO_LABEL_STACK);

}



static uint

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