Undefined paths and clists should use typed f_val with empty adata
instead of just void f_val. Use common initializer to handle both
variables and eattrs.
- Extend method descriptors with type signature
- Daisy chain method descriptors for the same symbol
- Dispatch methods for same symbol based on type signature
- Split add/delete/filter operations to multiple methods
- Replace ad-hoc dispatch of old-style syntax with scope-based dispatch
- Also change method->arg_num to count initial arg
It still needs some improvements, like better handling of untyped
expressions and better error reporting when no dispatch can be done.
The multiple dispatch could also be extended to dispatch regular
function-like expressions in a uniform way.
Methods can now be called as x.m(y), as long as x can have its type
inferred in config time. If used as a command, it modifies the object,
if used as a value, it keeps the original object intact.
Also functions add(x,y), delete(x,y), filter(x,y) and prepend(x,y) now
spit a warning and are considered deprecated.
It's also possible to call a method on a constant, see filter/test.conf
for examples like bgp_path = +empty+.prepend(1).
Inside instruction definitions (filter/f-inst.c), a METHOD_CONSTRUCTOR()
call is added, which registers the instruction as a method for the type
of its first argument. Each type has its own method symbol table and
filter parser switches between them based on the inferred type of the
object calling the method.
Also FI_CLIST_(ADD|DELETE|FILTER) instructions have been split to allow
for this method dispatch. With type inference, it's now possible.
The previous approach (use VOID constant for variable initialization)
failed due to dynamic type check failure.
Thanks to Alexander Zubkov <green@qrator.net> for the bugreport.
- Rename BYTESTRING lexem to BYTETEXT, not to collide with 'bytestring' type name
- Add bytestring type with id T_BYTESTRING (0x2c)
- Add from_hex() filter function to create bytestring from hex string
- Add filter test cases for bytestring type
Minor changes by committer.
Add static route attribute to set onlink flag for route next hop. Can be
used to build a dynamically routed IP-in-IP overlay network. Usage:
ifname = "tunl0";
onlink = true;
gw = bgp_next_hop;
Most branching instructions (FI_CONDITION, FI_AND, FI_OR) linearize its
branches in a recursive way, while FI_SWITCH branches are linearized
from parser even before the switch instruction is allocated.
Change linearization of FI_SWITCH branches to make it similar to other
branching instructions. This also fixes an issue with constant
switch evaluation, where linearized branch is mistaken for
non-linearized during switch construction.
Thanks to Jiten Kumar Pathy for the bugreport.
For loops allow to iterate over elements in compound data like BGP paths
or community lists. The syntax is:
for [ <type> ] <variable> in <expr> do <command-body>
Allow variable declarations mixed with code, also in nested blocks with
proper scoping, and with variable initializers. E.g:
function fn(int a)
{
int b;
int c = 10;
if a > 20 then
{
b = 30;
int d = c * 2;
print a, b, c, d;
}
string s = "Hello";
}
When f_line is done, we have to pop the stack frame. The old code just
removed nominal number of args/vars. Change it to use stored ventry value
modified by number of returned values. This allows to allocate variables
on a stack frame during execution of f_lines instead of just at start.
But we need to know the number of returned values for a f_line. It is 1
for term, 0 for cmd. Store that to f_line during linearization.
Direct recursion almost worked, just crashed on function signature check.
Split function parsing such that function signature is saved before
function body is processed. Recursive calls are marked so they can be
avoided during f_same() and similar code walking.
Also, include tower of hanoi solver as a test case.
Add literal for empty set [], which works both for tree-based sets
and prefix sets by using existing constant promotion mechanism.
Minor changes by committer.
All instructions with a return value (i.e. expressions, ones with
non-zero outval, third argument in INST()) should declare their return
type. Check that automatically by M4 macros.
Set outval of FI_RETURN to 0. The instruction adds one value to stack,
but syntactically it is a statement, not an expression.
Add fake return type declaration to FI_CALL, otherwise the automatic
check would fail builds.
Pass instructions of function call arguments as vararg arguments to
FI_CALL instruction constructor and move necessary magic from parser
code to interpreter / instruction code.
Add operators .min and .max to find minumum or maximum element in sets
of types: clist, eclist, lclist. Example usage:
bgp_community.min
bgp_ext_community.max
filter(bgp_large_community, [(as1, as2, *)]).min
Signed-off-by: Alexander Zubkov <green@qrator.net>
Add support to set or read outgoing MPLS labels using filters. Currently
this supports the addition of one label per route for the first next hop.
Minor changes by committer.
Broken detection of top-level case caused crash when return was called
from top-of-stack position. It should behave as reject/accept.
Thanks to Damian Zaremba for the bugreport.
Add 'weight' route attribute that allows to get and set ECMP weight of
nexthops. Similar to 'gw' attribute, it is limited to the first nexthop,
but it is useful for handling BGP multipath, where an ECMP route is
merged from multiple regular routes.
Implement regex-like '+' operator in BGP path masks to match previous
path mask item multiple times. This is useful as ASNs may appear
multiple times in paths due to path prepending for traffic engineering
purposes.
Do not apply dynamic type check for second argument of AND/OR, as it is
not evaluated immediately like regular argument would be.
Thanks to Mikael for the bugreport.
