pimd: don't use strcpy

>:(

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

Merge pull request #6248 from donaldsharp/zebra_snmp

some more coverity fixups

Merge pull request #6240 from ton31337/fix/null_bnc_bgp_show_hostname

bgpd: Add a sanitify check for bgp_nexthop_cache against NULL

pimd: if_lookup_by_index can fail handle it appropriately

It is possible that a if_lookup_by_index can return NULL
ensure that we handle this appropriately.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

lib: prefix must be a valid pointer at this point

Coverity does not understand how our CLI works.  Make it
happy that we have tested it's existence

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

ospfd: Fix possible null deref

It is possible that area is null, let's ensure it isn't.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

zebra: in_addr_cmp and `struct prefix` are not happy

Coverity is complaining that we are looking beyond the end
of the pointer.  Why not just use prefix_cmp here?  Since
we are comparing to route_nodes.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

Merge pull request #6247 from FRRouting/nb_conversions

Merge nb_converions branch to master

Merge pull request #6135 from opensourcerouting/cli-node-cleanup

*: clean up the mess that is CLI command nodes

Merge pull request #6239 from ton31337/fix/uint8_t_to_bool_for_any

bgpd, lib: Use bool instead of uint8_t for community/prefix-list "any"

lib: suppress formatting on yang.c module array

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

Merge pull request #5913 from taspelund/evpn_route_type_int

bgpd: Allow 'show bgp l2vpn evpn route type' to use RT number in addition to existing keywords

Merge pull request #6224 from mjstapp/zclient_session_id

lib,zebra: add a session id for zapi sessions

lib: fix style nit in yang_wrappers.c

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

zebra,ldpd: use zapi client session id in LM apis

Use the zapi client session id in the label manager apis;
use the client struct directly in some code. Assign a session
id to ldpd's sync LM zapi session.

Signed-off-by: Mark Stapp <mjs@voltanet.io>

lib,zebra: add a session id for zapi sessions

Distinguish zapi sessions, for daemons who use more than one,
by adding a session id. The tuple of proto + instance is not
adequate to support clients who use multiple zapi sessions.
Include the id in the client show output if it's present. Add
a bit of info about this to the developer doc.

Signed-off-by: Mark Stapp <mjs@voltanet.io>

zebra: add weight to nb conversion

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: add weight in nexthop operational model

add weight field to operational model.
add leafref to nexthopgroup.
format according to yanglint.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

lib: increase xpath maxlen

Certain xpath are well 256 characters, increasing
to 512.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

zebra: add northbound support for zebra interface

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

lib: remove gcc 4.x workaround for nb structure

Remove gcc 4.x workaround for variable size array as gcc
check moved to header file.

In lib/northbound.h : struct frr_yang_module_info made
size 1000 for gcc 4.x, where maximum 1000 nodes can fit.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

zebra: add nb callbacks for zebra if state

This is all stub callbacks autogenrated for
zebra interface state data.

Signed-off-by: chirag Shah <chirag@cumulusnetworks.com>

lib: add interface operational northbound callback

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: update zebra interface model

Modify interface config model
and add zebra specific interface state operational data.

augment /frr-interface:lib/frr-interface:interface:
  +--rw zebra
     +--rw ip-addrs* [address-family ip-prefix]
     |  +--rw address-family    identityref
     |  +--rw ip-prefix         ietf-inet-types:ip-prefix
     |  +--rw label?            string
     |  +--rw ip4-peer?         ietf-inet-types:ipv4-prefix
     +--rw multicast?     boolean
     +--rw link-detect?   boolean
     +--rw shutdown?      boolean
     +--rw bandwidth?     uint32
     +--ro state
        +--ro up-count?      uint16
        +--ro down-count?    uint16
        +--ro zif-type?      identityref
        +--ro ptm-status?    string <disabled>
        +--ro vlan-id?       uint16
        +--ro vni-id?        vni-id-type
        +--ro remote-vtep?   ietf-inet-types:ipv4-address
        +--ro mcast-group?   ietf-routing-types:ipv4-multicast-group-address

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: add operational data to frr-interface model

module: frr-interface
  +--rw lib
     +--rw interface* [name vrf]
        +--rw name           string
        +--rw vrf            frr-vrf:vrf-ref
        +--rw description?   string
        +--ro state
           +--ro if-index?      int32
           +--ro mtu?           uint16
           +--ro mtu6?          uint32
           +--ro speed?         uint32
           +--ro metric?        uint32
           +--ro flags?         if-flags-type
           +--ro type?          identityref
           +--ro phy-address?   ietf-yang-types:mac-address

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: add ietf interface yang model

Add ietf interface yant model.
Also include it in the makefile.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: igmp yang definition

Defined frr-igmp.yang file for IGMP protocol.

Co-authored-by: Sarita Patra <saritap@vmware.com>
Co-authored-by: Santosh P K <sapk@vmware.com>
Signed-off-by: Sarita Patra <saritap@vmware.com>

lib: yang wrapper nexthop type to str

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

lib: add yang wrapper for type empty

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

zebra: stub changes to assimilate re into rib nb

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: zebra rib model add route entry

FRR rib model need to accomodate route entries for
a given destination prefix.

Add a list of route entry under the list of prefix.

+--rw ribs
   +--rw rib* [afi-safi-name table-id]
      +--rw table-id         uint32
      +--rw afi-safi-name    identityref
      +--ro route* [prefix]
         +--ro prefix         ietf-inet-types:ip-prefix
         +--ro route-entry* [protocol]
            +--ro protocol           frr-route-types:frr-route-types-v4
            +--ro instance?          uint16
            +--ro distance?          uint8
            +--ro metric?            uint32
            +--ro tag?               uint32
            +--ro selected?          empty
            +--ro installed?         empty
            +--ro failed?            empty
            +--ro queued?            empty
            +--ro internal-flags?    int32
            +--ro internal-status?   int32
            +--ro uptime?            ietf-yang-types:date-and-time
            +--ro nexthop-group* [name]
               +--ro name            string
               +--ro frr-nexthops
                  +--ro nexthop* [nh-type gateway interface]
                     +--ro nh-type             frr-nexthop:nexthop-type
                     +--ro vrf?                frr-vrf:vrf-ref
                     +--ro gateway             frr-nexthop:optional-ip-address
                     +--ro interface           frr-interface:interface-ref
                     +--ro bh-type?            frr-nexthop:blackhole-type
                     +--ro onlink?             boolean <false>
                     +--ro mpls-label-stack
                     |  +--ro entry* [id]
                     |     +--ro id               uint8
                     |     +--ro label?           ietf-routing-types:mpls-label
                     |     +--ro ttl?             uint8
                     |     +--ro traffic-class?   uint8
                     +--ro duplicate?          empty
                     +--ro recursive?          empty
                     +--ro active?             empty
                     +--ro fib?                empty

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: zebra rib model remove grouping for ip route

Grouping is referencing leaves outside the grouping
from where it is used. Removing it and defining leaves
at the used place.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

zebra: convert clear evpn dup addr command to nb

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

zebra: nb rpc cb for clear evpn dup addr cmd

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

zebra: clear dup detect cleanup for nb conversion

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

lib:api to convert mac to yang object

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

zebra: nb callbacks support

Definition of the northbound callbacks
and associated YANG data paths for zebra.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: add zebra model in makefile

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

*: frr nexthop yang in makefile

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: zebra rib operational model

augment /frr-vrf:lib/frr-vrf:vrf:
  +--rw ribs
     +--rw rib* [afi-safi-name table-id]
        +--rw table-id         uint32
        +--rw afi-safi-name    identityref
        +--ro route* [prefix]
           +--ro prefix             ietf-inet-types:ip-prefix
           +--ro protocol?          frr-route-types:frr-route-types-v4
           +--ro protocol-v6?       frr-route-types:frr-route-types-v6
           +--ro vrf?               frr-vrf:vrf-ref
           +--ro distance?          uint8
           +--ro metric?            uint32
           +--ro tag?               uint32
           +--ro selected?          empty
           +--ro installed?         empty
           +--ro failed?            empty
           +--ro queued?            empty
           +--ro internal-flags?    int32
           +--ro internal-status?   int32
           +--ro uptime?            ietf-yang-types:date-and-time
           +--ro nexthop-group* [name]
              +--ro name            string
              +--ro frr-nexthops
                 +--ro nexthop* [nh-type gateway interface]
                    +--ro nh-type             frr-nexthop:nexthop-type
                    +--ro vrf?                frr-vrf:vrf-ref
                    +--ro gateway             frr-nexthop:optional-ip-address
                    +--ro interface           frr-interface:interface-ref
                    +--ro bh-type?            frr-nexthop:blackhole-type
                    +--ro onlink?             boolean <false>
                    +--ro mpls-label-stack
                    |  +--ro entry* [id]
                    |     +--ro id               uint8
                    |     +--ro label?           ietf-routing-types:mpls-label
                    |     +--ro ttl?             uint8
                    |     +--ro traffic-class?   uint8
                    +--ro duplicate?          empty
                    +--ro recursive?          empty
                    +--ro active?             empty
                    +--ro fib?                empty

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: revert leafref to get interface cmd working

Unable to access interface command:
root@bharat:~/stash/libyang/build# dpkg-query -W | grep libyang
libyang-dev 0.16.105-3~ubuntu18.04.1
libyang0.16 0.16.105-3~ubuntu18.04.1
root@bharat:~/stash/libyang/build# vtysh
bharat# config t
bharat(config)# interface lo
% Configuration failed: validation error.

Please check the logs for more details.

Logfile:
2020/03/21 16:48:55 ZEBRA: libyang: Leafref
"/frr-vrf:lib/frr-vrf:vrf/frr-vrf:name" of value "default"
points to a non-existing leaf.
(/frr-interface:lib/interface[name='lo'][vrf='default']/vrf)
2020/03/21 16:48:55 ZEBRA: [EC 100663337]
nb_candidate_commit_prepare: failed to validate
candidate configuration

CI system failure:
2020/03/21 18:53:18 ZEBRA: libyang: Leafref
"/frr-vrf:lib/frr-vrf:vrf/frr-vrf:name" of value "default"
points to a non-existing leaf.
(/frr-interface:lib/interface[name='r1-eth0'][vrf='default']/vrf)
2020/03/21 18:53:18 ZEBRA: [EC 100663337] nb_candidate_commit_prepare:
failed to validate candidate configuration
2020/03/21 18:53:18 ZEBRA: libyang: Leafref
"/frr-vrf:lib/frr-vrf:vrf/frr-vrf:name" of value "default"
points to a non-existing leaf.
(/frr-interface:lib/interface[name='r1-eth1'][vrf='default']/vrf)

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

lib: convert vrf cmd to northbound config callback

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

*: include vrf northbound module in init

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

lib: vrf northbound callbacks

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

lib: yang defination for basic frr-routing

Yang files for basic frr-routing used by other
daemons like staticd and pim

Co-authored-by: Santosh P K <sapk@vmware.com>
Co-authored-by: vishaldhingra <vdhingra@vmware.com>
Signed-off-by: vishaldhingra <vdhingra@vmware.com>

Merge pull request #5451 from opensourcerouting/rcu-log

logging subsystem rewrite

staticd: yang defination

Yang files for staticd to use northbound APIs

Co-authored-by: Santosh P K <sapk@vmware.com>
Co-authored-by: vishaldhingra <vdhingra@vmware.com>
Signed-off-by: vishaldhingra <vdhingra@vmware.com>

lib: FRR next-hop yang data model.

A common nexthop and group nexthop yang data model
for all protocols in FRR.

Co-authored-by: Santosh P K <sapk@vmware.com>
Co-authored-by: Vishaldhingra <vdhingra@vmware.com>
Signed-off-by: Santosh P K <sapk@vmware.com>

yang: add vrf ref to interface model

module: frr-interface
  +--rw lib
     +--rw interface* [name vrf]
        +--rw name           string
        +--rw vrf            frr-vrf:vrf-ref
        +--rw description?   string

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

*: add frr-vrf yang module in makefile

lib: Adding frr-vrf yang module to common place
so it can be accessed from all frr modules.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

yang: add vrf model

module: frr-vrf
  +--rw lib
     +--rw vrf* [name]
        +--rw name      string
        +--ro id?       uint32
        +--ro active?   boolean <false>
        +--rw netns {netns}?
           +--rw name?   string

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

bgpd: Add a sanitify check for bgp_nexthop_cache against NULL

In real world sometimes happens that bgp_nexthop_cache is NULL. Avoid
segfaulting when using `show [ip] bgp ...` CLI commands.

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>

Merge pull request #6238 from donaldsharp/test_evpn_vxlan_cleanup

tests: Cleanup bgp config for evpn vxlan topotest

bgpd, lib: Use bool instead of uint8_t for community/prefix-list "any"

That's only 0/1, useful to use just a bool for that.

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>

tests: Cleanup bgp config for evpn vxlan topotest

The bgp configuration for the vxlan topotest mixed
and matched some configuration that does not belong
for an IBGP setup.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

lib: #define FRR_CMD_NODE_20200416

... requested by Lou.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

vtysh: use parent_node for vtysh_exit()

Cleaning up the whole mess of "exit" and "quit" commands that follows is
left for a rainy day :(

Signed-off-by: David Lamparter <equinox@diac24.net>

*: add ->node_exit to struct cmd_node

Rather than doing a f*gly hack for the RPKI code, let's do an on-exit
hook in cmd_node.  Also allows replacing some special-casing in the vty
code.

Signed-off-by: David Lamparter <equinox@diac24.net>

zebra: fix FPM node reusing VTY_NODE

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

*: move CLI node names to cmd_node->name

And again for the name.  Why on earth would we centralize this, just so
people can forget to update it?

Signed-off-by: David Lamparter <equinox@diac24.net>

*: move CLI parent data to cmd_node->parent_node

Same as before, instead of shoving this into a big central list we can
just put the parent node in cmd_node.

Signed-off-by: David Lamparter <equinox@diac24.net>

*: remove second parameter on install_node()

There is really no reason to not put this in the cmd_node.

And while we're add it, rename from pointless ".func" to ".config_write".

[v2: fix forgotten ldpd config_write]

Signed-off-by: David Lamparter <equinox@diac24.net>

*: remove cmd_node->vtysh

The only nodes that have this as 0 don't have a "->func" anyway, so the
entire thing is really just pointless.

Signed-off-by: David Lamparter <equinox@diac24.net>

*: clean up cmd_node initializers

... and use named assignments everywhere (so I can change the struct.)

Signed-off-by: David Lamparter <equinox@diac24.net>

Merge pull request #6237 from ton31337/fix/show_hostname_in_bgp

bgpd: Show hostname in `show [ip] bgp ...` only if nexthop is connected

tests: Check if the right next-hop is shown (bgp_show_ip_bgp_fqdn)

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>

bgpd: Show hostname in `show [ip] bgp ...` only if nexthop is connected

The problem is when using kinda such topologies:
(192.168.1.1/32) r1 <-- eBGP --> r2 <-- iBGP --> r3

Looking at r3's nexthop for 192.168.1.1/32 we have it as r2, but really
it MUST be r1.

Checking if the nexthop is connected solves the problem even for cases
when route-reflectors are used.

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>

Merge pull request #6232 from ton31337/fix/validate_lcommunities

bgpd: Validate all large communities if specified more per line

Merge pull request #6229 from donaldsharp/netlink_request_fixup

zebra: Modify netlink_request to statisfy coverity

bgpd: Validate all large communities if specified more per line

```
(config)# bgp large-community-list standard FRR-1 permit 1:1:1:1
% Malformed community-list value
(config)# bgp large-community-list standard FRR-1 permit 1:1:1 1:2
% Malformed community-list value
(config)# bgp large-community-list standard FRR-1 permit 1:1:1 1:2 3:3:2
% Malformed community-list value
(config)# bgp large-community-list standard FRR-1 permit 1:1:1 1:2 3:3:2 0:0:0
% Malformed community-list value
(config)# bgp large-community-list standard FRR-1 permit 0:0:1231321231414
% Malformed community-list value
(config)# bgp large-community-list standard FRR-1 permit 1:1:1 1:2:3 3:3:2 0:0:
% Malformed community-list value
(config)# bgp large-community-list standard FRR-1 permit 1:1:1 1:2:3 3:3:2 0:2:3
(config)# bgp large-community-list standard FRR-1 permit 1:1:1 1:2:3 3:3:2
(config)#
```

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>

Merge pull request #6230 from donaldsharp/nhrp_json_silliness

nhrpd: Actually allow json output

Merge pull request #6226 from LabNConsulting/ziemba/ldpd-fix-md5key-length

ldpd: ldp_vty_neighbor_password(): fix auth.md5key_len calculation

nhrpd: Actually allow json output

Add the correct pointer check to see if we should
be doing json output.

Discovered by SA.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

zebra: Modify netlink_request to statisfy coverity

The netlink_request function takes a `struct nlmsghdr *`
pointer from a common pattern that we use:

struct {
struct nlmsghdr n;
struct fib_rule_hdr frh;
char buf[NL_PKT_BUF_SIZE];
} req;

We were calling it `netlink_request(Socket, &req.n)`

The problem here is that coverity, rightly so, sees that
we access the data after the nlmsghdr in netlink_request and
tells us we have an read beyond end of the structure.  While
we know we haven't mangled anything up here because of manual
inspection coverity doesn't have this knowledge implicitly.

So let's modify the code call to netlink_request to pass in the
void pointer of the req structure itself, cast to the appropriate
data structure in the function and do the right thing.  Hopefully
the coverity SA will be happy and we can move on with our life.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

Merge pull request #6154 from donaldsharp/check_interface_working

tests: Add a route-map test to ensure it accepts an unknown intf name

ldpd: ldp_vty_neighbor_password(): fix auth.md5key_len calculation

Per issue #6202

Very long passwords (>79 chars) get truncated: save truncated
length in nbrp->auth.md5key_len instead of original length.

Signed-off-by: G. Paul Ziemba <paulz@labn.net>

doc: Add doc for `show bgp l2vpn evpn route type`

Add documentation for this command and its RT filters.

Signed-off-by: Trey Aspelund <taspelund@cumulusnetworks.com>

bgpd: Add int args to `show bgp evpn route type`

This adds numeric keywords to 'show bgp l2vpn evpn route type'.

Signed-off-by: Trey Aspelund <taspelund@cumulusnetworks.com>

Merge pull request #6225 from qlyoung/fix-zebra-counter-printf-specifiers

zebra: use %u for unsigned when printing counters

Merge pull request #6214 from opensourcerouting/bfdd-debug

bfdd: code/logging/debug improvements

bgpd: Fix typos in `show bgp evpn route type`

This fixes unnecessary whitespaces and makes capitalization
match for route type help strings.

Signed-off-by: Trey Aspelund <taspelund@cumulusnetworks.com>

Merge pull request #6211 from mjstapp/fix_zebra_cov

zebra: fix some coverity SA warnings

Merge pull request #5510 from opensourcerouting/dplane-fpm-netlink

zebra: netlink FPM interface using zebra data plane

zebra: use %u for unsigned when printing counters

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

Merge pull request #5812 from pguibert6WIND/bgp_stats_all

Bgp stats all

Merge pull request #6218 from qlyoung/fix-ospf-router-lsa-missing-length-check

ospfd: router LSA link info missing length check

zebra: fix hash_backet typo in data plane FPM

Implement the fix made in `master` to the remain pieces of code in the
data plane FPM module.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: hide verbose data plane FPM log messages

To enable them just configure `debug zebra fpm`.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: fix some formatting/style issues

* Break lines longer than 80 columns.
* Remove space after '('.
* Use '%pIX' instead of 'inet_ntop'.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: data plane FPM add support RMAC VNI

Store VNI information in the data plane context so we can use it to
build the FPM netlink update with that information later.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: fix style on data plane FPM module

*   Use 32bit atomic instead of 64bit.
*   Don't use semicolon at the end of macros.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

build: fix data plane FPM netlink module

Changes:

*   Let the package builder scripts know that we have a new module that
    needs to be taken care of.
*   Include the frr atomic header to avoid undeclared atomic operations.
*   Disable build on *BSDs because the code is using some zebra netlink
    functions only available for Linux.
*   Move data plane FPM module outside old FPM automake definition.
*   Fix atomic usage for Ubuntu 14.04 (always use explicit).

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: use atomic operations in FPM

FPM has a thread to encode and enqueue output buffer that might compete
with zebra RIB/RMAC walk on startup, so lets use atomic operations to
make sure we are not getting statistic/counters wrong.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: queue data plane context for FPM

Enqueue all contexts inside FPM to avoid losing updates and to move all
processing to the FPM thread.

This helps in situations with huge amount of routes (e.g. BGP peer
flapping with a million routes).

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: improve FPM output buffer handling

Add counters to debug the output buffer usage and pull down its data
when the remote receiver is slow (so we get more space for writes).

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: simplify FPM buffer full detection

Remove code duplication and document hardcoded values.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: implement FPM counters

Add commands to show and reset FPM counters.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: CLI commands for new FPM interface

Add commands to enable/disable and configure FPM.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: data plane FPM RMAC walk code

Implement the code that walks the RMAC to send routes that are already
inside installed in the OS.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

zebra: adapt and export rmac netlink functions

Those functions are going to be used by the new data plane plugin for
netlink FPM.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>