VPP-ites,
I am delving into the world of static routes. I am clearly missing
some basic information and would like some help understanding
how static routes work.
For starters, I'm a little unclear on what exactly these items are,
or what they represent or hold, and their relationship to each other:
- VRF index / VRF id
- Table id
- FIB index / FIB id
The only place I can find that even defines "VRF" is on this wiki page:
https://wiki.fd.io/view/VPP/What_is_VPP%3F
(Yeah, the final %3F is needed.)
And even that is in passing:
Some of the functionality that a routing application can create includes:
o Virtual Routing and Forwarding (VRF) tables (in the thousands)
How is a VRF created/deleted/managed? I don't see an obvious API call
that looks like it would create/delete one:
$ git grep -i vrf | grep add_del
src/plugins/nat/nat64.c:nat64_add_del_pool_addr (ip4_address_t * addr,
u32 vrf_id, u8 is_add)
src/plugins/nat/nat64.c:nat64_add_del_prefix (ip6_address_t * prefix,
u8 plen, u32 vrf_id, u8 is_add)
src/plugins/nat/nat64.h:int nat64_add_del_pool_addr (ip4_address_t *
addr, u32 vrf_id, u8 is_add);
src/plugins/nat/nat64.h:int nat64_add_del_prefix (ip6_address_t *
prefix, u8 plen, u32 vrf_id,
src/plugins/nat/nat64_cli.c: rv = nat64_add_del_pool_addr
(&this_addr, vrf_id, is_add);
src/plugins/nat/nat64_cli.c: rv = nat64_add_del_prefix (&prefix, (u8)
plen, vrf_id, is_add);
src/plugins/nat/nat_api.c: if ((rv = nat64_add_del_pool_addr
(&this_addr, vrf_id, mp->is_add)))
src/plugins/nat/nat_api.c: s = format (0, "SCRIPT:
nat64_add_del_prefix %U/%u vrf_id %u %s\n",
src/vat/api_format.c:_(oam_add_del, "src <ip4-address> dst
<ip4-address> [vrf <n>] [del]") \
src/vat/api_format.c:_(one_eid_table_add_del_map, "[del] vni <vni> vrf
<vrf>") \
src/vat/api_format.c:_(lisp_eid_table_add_del_map, "[del] vni <vni>
vrf <vrf>") \
test/test_nat.py:
self.vapi.nat64_add_del_pool_addr_range(self.vrf1_nat_addr_n,
test/test_nat.py:
self.vapi.nat64_add_del_pool_addr_range(self.vrf1_nat_addr_n,
test/test_nat.py: self.vapi.nat64_add_del_prefix(vrf1_pref64_n,
test/vpp_papi_provider.py: def nat64_add_del_prefix(self, prefix,
plen, vrf_id=0, is_add=1):
Tables, on the other hand, can be created/deleted:
src/vnet/ip/ip.api:autoreply define ip_table_add_del
src/vnet/ip/ip_api.c:_(IP_TABLE_ADD_DEL, ip_table_add_del)
\
src/vnet/ip/ip_api.c:vl_api_ip_table_add_del_t_handler
(vl_api_ip_table_add_del_t * mp)
Is this the right "table"?
What is the lifetime management of a table? When is it OK to delete one?
Does it have to come into existence before any thing references the Table Id?
Or is it OK to have a dangling Table Id pointer for a while?
What happens if you use the API to delete it and there are lingering referrers?
But let's face it "table" is very generic. What kind of table is
that? And there
is no better name for it than "table"? Wait. Don't answer yet.
Let's check at
the API definition first:
/** \brief Add / del table request
A table can be added multiple times, but need be
deleted only once.
@param client_index - opaque cookie to identify the sender
@param context - sender context, to match reply w/ request
@param is_ipv6 - V4 or V6 table
@param table_id - table ID associated with the route
This table ID will apply to both the unicast
and mlticast FIBs.
*/
autoreply define ip_table_add_del
{
u32 client_index;
u32 context;
u32 table_id;
u8 is_ipv6;
u8 is_add;
};
But still, no clue what the table is, what it manages, what it holds,
what abstraction
it provides. Nothing.
Is it really an arbitrary "Table" of anything you want? Are these
used for several (?)
unrelated items and a generic "Table" is really appropriate?
It appears that a "table id" can sometimes be a FIB table id:
/** \brief IP FIB table response
@param table_id - IP fib table id
But clearly they are not the same:
src/vnet/dhcp/dhcp_proxy.h: * @brief The FIB index (not the
external Table-ID) in which the server
src/vnet/dhcp/dhcp_proxy.h: * @brief The FIB index (not the
external Table-ID) in which the client
OK. Let's turn to some commands for help or insight.
NAT wants VRF ids:
VLIB_CLI_COMMAND (add_address_command, static) = {
.path = "nat44 add address",
.short_help = "nat44 add addresses <ip4-range-start> [- <ip4-range-end>] "
"[tenant-vrf <vrf-id>] [del]",
VLIB_CLI_COMMAND (add_static_mapping_command, static) = {
.path = "nat44 add static mapping",
.function = add_static_mapping_command_fn,
.short_help =
"nat44 add static mapping local tcp|udp|icmp <addr> [<port>]
external <addr> [<port>] [vrf <table-id>] [del]",
};
Ooo! Look at that penultimate bit: [vrf <table-id>]
So. Is a "table id" the same thing as a "VRF id"?
I find no discussion or description of any of this in any of the wiki,
nor in the online docs.fd.io,
nor in the VPP source repo itself. What am I missing?
Any help?
Thanks,
jdl
_______________________________________________
vpp-dev mailing list
vpp-dev@lists.fd.io
https://lists.fd.io/mailman/listinfo/vpp-dev
