ospfd: add support for suppress_fa

This command will trigger the OSPF forwarding address suppression in
translated type-5 LSAs, causing a NSSA ABR to use 0.0.0.0 as a forwarding
address instead of copying the address from the type-7 LSA

Example: In a topology like: R1 --- R2(ABR) --- R3(ASBR)

R3 is announcing a type-7 LSA that is translated to type-5 by the R2 ABR.
The forwarding address in the type-5 is by default copied from the type-7

    r1# sh ip os da external

                    AS External Link States

      LS age: 6
      Options: 0x2  : *|-|-|-|-|-|E|-
      LS Flags: 0x6
      LS Type: AS-external-LSA
      Link State ID: 3.3.3.3 (External Network Number)
      Advertising Router: 10.0.25.2
      LS Seq Number: 80000001
      Checksum: 0xcf99
      Length: 36

      Network Mask: /32
            Metric Type: 2 (Larger than any link state path)
            TOS: 0
            Metric: 20
            Forward Address: 10.0.23.3    <--- address copied from type-7 lsa
            External Route Tag: 0

    r2# sh ip os database

                    NSSA-external Link States (Area 0.0.0.1 [NSSA])

    Link ID         ADV Router      Age  Seq#       CkSum  Route
    3.3.3.3         10.0.23.3          8 0x80000001 0x431d E2 3.3.3.3/32 [0x0]

                    AS External Link States

    Link ID         ADV Router      Age  Seq#       CkSum  Route
    3.3.3.3         10.0.25.2          0 0x80000001 0xcf99 E2 3.3.3.3/32 [0x0]

    r2# conf t
    r2(config)# router ospf
    r2(config-router)# area 1 nssa suppress-fa
    r2(config-router)# exit
    r2(config)# exit

    r2# sh ip os database

                    NSSA-external Link States (Area 0.0.0.1 [NSSA])

    Link ID         ADV Router      Age  Seq#       CkSum  Route
    3.3.3.3         10.0.23.3         66 0x80000001 0x431d E2 3.3.3.3/32 [0x0]

                    AS External Link States

    Link ID         ADV Router      Age  Seq#       CkSum  Route
    3.3.3.3         10.0.25.2         16 0x80000002 0x0983 E2 3.3.3.3/32 [0x0]

    r1# sh ip os da external

           OSPF Router with ID (11.11.11.11)

                    AS External Link States

      LS age: 34
      Options: 0x2  : *|-|-|-|-|-|E|-
      LS Flags: 0x6
      LS Type: AS-external-LSA
      Link State ID: 3.3.3.3 (External Network Number)
      Advertising Router: 10.0.25.2
      LS Seq Number: 80000002
      Checksum: 0x0983
      Length: 36

      Network Mask: /32
            Metric Type: 2 (Larger than any link state path)
            TOS: 0
            Metric: 20
            Forward Address: 0.0.0.0       <--- address set to 0
            External Route Tag: 0

    r2# conf t
    r2(config)# router ospf
    r2(config-router)# no area 1 nssa suppress-fa
    r2(config-router)# exit

    r1# sh ip os da external

           OSPF Router with ID (11.11.11.11)

                    AS External Link States

      LS age: 1
      Options: 0x2  : *|-|-|-|-|-|E|-
      LS Flags: 0x6
      LS Type: AS-external-LSA
      Link State ID: 3.3.3.3 (External Network Number)
      Advertising Router: 10.0.25.2
      LS Seq Number: 80000003
      Checksum: 0xcb9b
      Length: 36
      Network Mask: /32
            Metric Type: 2 (Larger than any link state path)
            TOS: 0
            Metric: 20
            Forward Address: 0.0.0.0       <--- address set to 0
            External Route Tag: 0

    r2# conf t
    r2(config)# router ospf
    r2(config-router)# no area 1 nssa suppress-fa
    r2(config-router)# exit

    r1# sh ip os da external

           OSPF Router with ID (11.11.11.11)

                    AS External Link States

      LS age: 1
      Options: 0x2  : *|-|-|-|-|-|E|-
      LS Flags: 0x6
      LS Type: AS-external-LSA
      Link State ID: 3.3.3.3 (External Network Number)
      Advertising Router: 10.0.25.2
      LS Seq Number: 80000003
      Checksum: 0xcb9b
      Length: 36

      Network Mask: /32
            Metric Type: 2 (Larger than any link state path)
            TOS: 0
            Metric: 20
            Forward Address: 10.0.23.3    <--- address copied from type-7 lsa
            External Route Tag: 0

Signed-off-by: ckishimo <carles.kishimoto@gmail.com>
This commit is contained in:
ckishimo 2020-11-02 06:28:52 -08:00 committed by Carles Kishimoto Bisbe
parent d71494e6a4
commit c317eddbce
6 changed files with 126 additions and 9 deletions

View File

@ -675,7 +675,8 @@ static int ospf_abr_translate_nssa(struct ospf_area *area, struct ospf_lsa *lsa)
* originate translated LSA
*/
if (ospf_translated_nssa_originate(area->ospf, lsa) == NULL) {
if (ospf_translated_nssa_originate(area->ospf, lsa, old)
== NULL) {
if (IS_DEBUG_OSPF_NSSA)
zlog_debug(
"ospf_abr_translate_nssa(): Could not translate Type-7 for %pI4 to Type-5",

View File

@ -1765,7 +1765,14 @@ static struct ospf_lsa *ospf_lsa_translated_nssa_new(struct ospf *ospf,
/* copy over Type-7 data to new */
extnew->e[0].tos = ext->e[0].tos;
extnew->e[0].route_tag = ext->e[0].route_tag;
extnew->e[0].fwd_addr.s_addr = ext->e[0].fwd_addr.s_addr;
if (type7->area->suppress_fa) {
extnew->e[0].fwd_addr.s_addr = 0;
if (IS_DEBUG_OSPF_NSSA)
zlog_debug(
"ospf_lsa_translated_nssa_new(): Suppress forwarding address for %pI4",
&ei.p.prefix);
} else
extnew->e[0].fwd_addr.s_addr = ext->e[0].fwd_addr.s_addr;
new->data->ls_seqnum = type7->data->ls_seqnum;
/* add translated flag, checksum and lock new lsa */
@ -1777,7 +1784,8 @@ static struct ospf_lsa *ospf_lsa_translated_nssa_new(struct ospf *ospf,
/* Originate Translated Type-5 for supplied Type-7 NSSA LSA */
struct ospf_lsa *ospf_translated_nssa_originate(struct ospf *ospf,
struct ospf_lsa *type7)
struct ospf_lsa *type7,
struct ospf_lsa *type5)
{
struct ospf_lsa *new;
struct as_external_lsa *extnew;
@ -1796,6 +1804,10 @@ struct ospf_lsa *ospf_translated_nssa_originate(struct ospf *ospf,
extnew = (struct as_external_lsa *)new->data;
/* Update LSA sequence number from translated Type-5 LSA */
if (type5)
new->data->ls_seqnum = lsa_seqnum_increment(type5);
if ((new = ospf_lsa_install(ospf, NULL, new)) == NULL) {
flog_warn(EC_OSPF_LSA_INSTALL_FAILURE,
"%s: Could not install LSA id %pI4", __func__,
@ -1823,6 +1835,8 @@ struct ospf_lsa *ospf_translated_nssa_refresh(struct ospf *ospf,
struct ospf_lsa *type5)
{
struct ospf_lsa *new = NULL;
struct as_external_lsa *extold = NULL;
uint32_t ls_seqnum = 0;
/* Sanity checks. */
assert(type7 || type5);
@ -1887,6 +1901,12 @@ struct ospf_lsa *ospf_translated_nssa_refresh(struct ospf *ospf,
return NULL;
}
extold = (struct as_external_lsa *)type5->data;
if (type7->area->suppress_fa == 1) {
if (extold->e[0].fwd_addr.s_addr == 0)
ls_seqnum = ntohl(type5->data->ls_seqnum);
}
/* Delete LSA from neighbor retransmit-list. */
ospf_ls_retransmit_delete_nbr_as(ospf, type5);
@ -1899,6 +1919,11 @@ struct ospf_lsa *ospf_translated_nssa_refresh(struct ospf *ospf,
return NULL;
}
if (type7->area->suppress_fa == 1) {
if (extold->e[0].fwd_addr.s_addr == 0)
new->data->ls_seqnum = htonl(ls_seqnum + 1);
}
if (!(new = ospf_lsa_install(ospf, NULL, new))) {
flog_warn(
EC_OSPF_LSA_INSTALL_FAILURE,

View File

@ -341,11 +341,12 @@ extern char link_info_set(struct stream **s, struct in_addr id,
extern struct in_addr ospf_get_nssa_ip(struct ospf_area *);
extern int ospf_translated_nssa_compare(struct ospf_lsa *, struct ospf_lsa *);
extern struct ospf_lsa *ospf_translated_nssa_refresh(struct ospf *,
struct ospf_lsa *,
struct ospf_lsa *);
extern struct ospf_lsa *ospf_translated_nssa_originate(struct ospf *,
struct ospf_lsa *);
extern struct ospf_lsa *ospf_translated_nssa_refresh(struct ospf *ospf,
struct ospf_lsa *type7,
struct ospf_lsa *type5);
extern struct ospf_lsa *ospf_translated_nssa_originate(struct ospf *ospf,
struct ospf_lsa *type7,
struct ospf_lsa *type5);
extern void ospf_flush_lsa_from_area(struct ospf *ospf, struct in_addr area_id,
int type);
#endif /* _ZEBRA_OSPF_LSA_H */

View File

@ -1574,6 +1574,58 @@ DEFUN (ospf_area_nssa,
return ospf_area_nssa_cmd_handler(vty, argc, argv, 0, 0);
}
DEFUN(ospf_area_nssa_suppress_fa, ospf_area_nssa_suppress_fa_cmd,
"area <A.B.C.D|(0-4294967295)> nssa suppress-fa",
"OSPF area parameters\n"
"OSPF area ID in IP address format\n"
"OSPF area ID as a decimal value\n"
"Configure OSPF area as nssa\n"
"Suppress forwarding address\n")
{
int idx_ipv4_number = 1;
struct in_addr area_id;
int format;
VTY_DECLVAR_INSTANCE_CONTEXT(ospf, ospf);
VTY_GET_OSPF_AREA_ID_NO_BB("NSSA", area_id, format,
argv[idx_ipv4_number]->arg);
ospf_area_display_format_set(ospf, ospf_area_get(ospf, area_id),
format);
ospf_area_nssa_suppress_fa_set(ospf, area_id);
ospf_schedule_abr_task(ospf);
return CMD_SUCCESS;
}
DEFUN(no_ospf_area_nssa_suppress_fa, no_ospf_area_nssa_suppress_fa_cmd,
"no area <A.B.C.D|(0-4294967295)> nssa suppress-fa",
NO_STR
"OSPF area parameters\n"
"OSPF area ID in IP address format\n"
"OSPF area ID as a decimal value\n"
"Configure OSPF area as nssa\n"
"Suppress forwarding address\n")
{
int idx_ipv4_number = 2;
struct in_addr area_id;
int format;
VTY_DECLVAR_INSTANCE_CONTEXT(ospf, ospf);
VTY_GET_OSPF_AREA_ID_NO_BB("nssa", area_id, format,
argv[idx_ipv4_number]->arg);
ospf_area_display_format_set(ospf, ospf_area_get(ospf, area_id),
format);
ospf_area_nssa_suppress_fa_unset(ospf, area_id);
ospf_schedule_abr_task(ospf);
return CMD_SUCCESS;
}
DEFUN (ospf_area_nssa_no_summary,
ospf_area_nssa_no_summary_cmd,
"area <A.B.C.D|(0-4294967295)> nssa no-summary",
@ -11823,6 +11875,10 @@ static int config_write_ospf_area(struct vty *vty, struct ospf *ospf)
vty_out(vty,
" area %s nssa no-summary\n",
buf);
if (area->suppress_fa)
vty_out(vty,
" area %s nssa suppress-fa\n",
buf);
}
if (area->default_cost != 1)
@ -12684,6 +12740,8 @@ void ospf_vty_init(void)
install_element(OSPF_NODE, &ospf_area_nssa_translate_cmd);
install_element(OSPF_NODE, &ospf_area_nssa_no_summary_cmd);
install_element(OSPF_NODE, &no_ospf_area_nssa_no_summary_cmd);
install_element(OSPF_NODE, &ospf_area_nssa_suppress_fa_cmd);
install_element(OSPF_NODE, &no_ospf_area_nssa_suppress_fa_cmd);
install_element(OSPF_NODE, &no_ospf_area_nssa_cmd);
install_element(OSPF_NODE, &ospf_area_default_cost_cmd);

View File

@ -1672,6 +1672,7 @@ int ospf_area_nssa_set(struct ospf *ospf, struct in_addr area_id)
/* set NSSA area defaults */
area->no_summary = 0;
area->suppress_fa = 0;
area->NSSATranslatorRole = OSPF_NSSA_ROLE_CANDIDATE;
area->NSSATranslatorState = OSPF_NSSA_TRANSLATE_DISABLED;
area->NSSATranslatorStabilityInterval =
@ -1693,6 +1694,7 @@ int ospf_area_nssa_unset(struct ospf *ospf, struct in_addr area_id, int argc)
ospf->anyNSSA--;
/* set NSSA area defaults */
area->no_summary = 0;
area->suppress_fa = 0;
area->NSSATranslatorRole = OSPF_NSSA_ROLE_CANDIDATE;
area->NSSATranslatorState = OSPF_NSSA_TRANSLATE_DISABLED;
area->NSSATranslatorStabilityInterval =
@ -1708,6 +1710,32 @@ int ospf_area_nssa_unset(struct ospf *ospf, struct in_addr area_id, int argc)
return 1;
}
int ospf_area_nssa_suppress_fa_set(struct ospf *ospf, struct in_addr area_id)
{
struct ospf_area *area;
area = ospf_area_lookup_by_area_id(ospf, area_id);
if (area == NULL)
return 0;
area->suppress_fa = 1;
return 1;
}
int ospf_area_nssa_suppress_fa_unset(struct ospf *ospf, struct in_addr area_id)
{
struct ospf_area *area;
area = ospf_area_lookup_by_area_id(ospf, area_id);
if (area == NULL)
return 0;
area->suppress_fa = 0;
return 1;
}
int ospf_area_nssa_translator_role_set(struct ospf *ospf,
struct in_addr area_id, int role)
{

View File

@ -476,7 +476,7 @@ struct ospf_area {
int shortcut_capability; /* Other ABRs agree on S-bit */
uint32_t default_cost; /* StubDefaultCost. */
int auth_type; /* Authentication type. */
int suppress_fa; /* Suppress forwarding address in NSSA ABR */
uint8_t NSSATranslatorRole; /* NSSA configured role */
#define OSPF_NSSA_ROLE_NEVER 0
@ -668,6 +668,10 @@ extern int ospf_area_no_summary_set(struct ospf *, struct in_addr);
extern int ospf_area_no_summary_unset(struct ospf *, struct in_addr);
extern int ospf_area_nssa_set(struct ospf *, struct in_addr);
extern int ospf_area_nssa_unset(struct ospf *, struct in_addr, int);
extern int ospf_area_nssa_suppress_fa_set(struct ospf *ospf,
struct in_addr area_id);
extern int ospf_area_nssa_suppress_fa_unset(struct ospf *ospf,
struct in_addr area_id);
extern int ospf_area_nssa_translator_role_set(struct ospf *, struct in_addr,
int);
extern int ospf_area_export_list_set(struct ospf *, struct ospf_area *,