Conf: Allowing keyword redefinition

Some tokens are both keywords and symbols. For now, we allow only
specific keywords to be redefined; in future, more of the keywords may
be added to this category.

The redefinable keywords must be specified in any .Y file as follows:

  toksym: THE_KEYWORD ;

See proto/bgp/config.Y for an example.

Also dropped a lot of unused terminals.

13 files changed, 46 insertions, 48 deletions

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index e84e1d9d..11bcdb18 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -709,10 +709,7 @@ cf_lex_symbol(const char *data)
   struct symbol *sym = cf_get_symbol(data);
   cf_lval.s = sym;
 
-  if (sym->class != SYM_VOID)
-    return CF_SYM_KNOWN;
-
-  /* Is it a keyword? */
+  /* Is it a keyword? Prefer the keyword. */
   struct keyword *k = HASH_FIND(kw_hash, KW, data);
   if (k)
   {
@@ -725,9 +722,11 @@ cf_lex_symbol(const char *data)
     }
   }
 
-  /* OK, undefined symbol */
-  cf_lval.s = sym;
-  return CF_SYM_UNDEFINED;
+  /* OK, only a symbol. */
+  if (sym->class == SYM_VOID)
+    return CF_SYM_UNDEFINED;
+  else
+    return CF_SYM_KNOWN;
 }
 
 static void
diff --git a/conf/confbase.Y b/conf/confbase.Y
index 2286b257..8a27c3d5 100644
--- a/conf/confbase.Y
+++ b/conf/confbase.Y
@@ -116,7 +116,7 @@ CF_DECLS
 %type <mls> label_stack_start label_stack
 
 %type <t> text opttext
-%type <s> symbol
+%type <s> symbol symbol_known toksym 
 
 %nonassoc PREFIX_DUMMY
 %left AND OR
@@ -162,7 +162,7 @@ definition:
 expr:
    NUM
  | '(' term ')' { $$ = f_eval_int(f_linearize($2)); }
- | CF_SYM_KNOWN {
+ | symbol_known {
      if ($1->class != (SYM_CONSTANT | T_INT)) cf_error("Number constant expected");
      $$ = SYM_VAL($1).i; }
  ;
@@ -173,7 +173,9 @@ expr_us:
  | expr US { $$ = $1 US_; }
  ;
 
-symbol: CF_SYM_UNDEFINED | CF_SYM_KNOWN ;
+toksym: FROM ;
+symbol: CF_SYM_UNDEFINED | CF_SYM_KNOWN | toksym ;
+symbol_known: CF_SYM_KNOWN | toksym ;
 
 /* Switches */
 
diff --git a/conf/gen_keywords.m4 b/conf/gen_keywords.m4
index 0c1dc545..53226e4d 100644
--- a/conf/gen_keywords.m4
+++ b/conf/gen_keywords.m4
@@ -26,8 +26,7 @@ m4_define(CF_DEFINES, `m4_divert(-1)')
 m4_define(CF_handle_kw, `m4_divert(1){ "m4_translit($1,[[A-Z]],[[a-z]])", $1, NULL },
 m4_divert(-1)')
 m4_define(CF_keywd, `m4_ifdef([[CF_tok_$1]],,[[m4_define([[CF_tok_$1]],1)CF_handle_kw($1)]])')
-m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token[[]]CF_toks
-)DNL')
+m4_define(CF_KEYWORDS, `CF_iterate([[CF_keywd]], [[$@]])DNL')
 
 # CLI commands generate keywords as well
 m4_define(CF_CLI, `CF_KEYWORDS(m4_translit($1, [[ ]], [[,]]))
diff --git a/conf/gen_parser.m4 b/conf/gen_parser.m4
index 5b378a93..af4b1455 100644
--- a/conf/gen_parser.m4
+++ b/conf/gen_parser.m4
@@ -31,7 +31,7 @@ m4_define(CF_iterate, `m4_define([[CF_iter]], m4_defn([[$1]]))CF_itera($2)')
 
 # Keywords act as untyped %token
 m4_define(CF_keywd, `m4_ifdef([[CF_tok_$1]],,[[m4_define([[CF_tok_$1]],1)m4_define([[CF_toks]],CF_toks $1)]])')
-m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token[[]]CF_toks
+m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token<s>[[]]CF_toks
 )DNL')
 
 # CLI commands
diff --git a/filter/config.Y b/filter/config.Y
index e24233aa..7dcdb779 100644
--- a/filter/config.Y
+++ b/filter/config.Y
@@ -291,8 +291,8 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
 	LEN, MAXLEN,
 	DATA, DATA1, DATA2,
 	DEFINED,
-	ADD, DELETE, CONTAINS, RESET,
-	PREPEND, FIRST, LAST, LAST_NONAGGREGATED, MATCH,
+	ADD, DELETE, RESET,
+	PREPEND, FIRST, LAST, LAST_NONAGGREGATED,
 	MIN, MAX,
 	EMPTY,
 	FILTER, WHERE, EVAL, ATTRIBUTE,
@@ -357,7 +357,7 @@ custom_attr: ATTRIBUTE type symbol ';' {
 
 conf: bt_test_suite ;
 bt_test_suite:
- BT_TEST_SUITE '(' CF_SYM_KNOWN ',' text ')' {
+ BT_TEST_SUITE '(' symbol_known ',' text ')' {
   cf_assert_symbol($3, SYM_FUNCTION);
   struct f_bt_test_suite *t = cfg_allocz(sizeof(struct f_bt_test_suite));
   t->fn = $3->function;
@@ -370,7 +370,7 @@ bt_test_suite:
 
 conf: bt_test_same ;
 bt_test_same:
- BT_TEST_SAME '(' CF_SYM_KNOWN ',' CF_SYM_KNOWN ',' NUM ')' {
+ BT_TEST_SAME '(' symbol_known ',' symbol_known ',' NUM ')' {
   cf_assert_symbol($3, SYM_FUNCTION);
   cf_assert_symbol($5, SYM_FUNCTION);
   struct f_bt_test_suite *t = cfg_allocz(sizeof(struct f_bt_test_suite));
@@ -448,7 +448,7 @@ function_vars:
 filter_body: function_body ;
 
 filter:
-   CF_SYM_KNOWN {
+   symbol_known {
      cf_assert_symbol($1, SYM_FILTER);
      $$ = $1->filter;
    }
@@ -549,7 +549,7 @@ set_atom:
      if (f_eval(f_linearize($2), &($$)) > F_RETURN) cf_error("Runtime error");
      if (!f_valid_set_type($$.type)) cf_error("Set-incompatible type");
    }
- | CF_SYM_KNOWN {
+ | symbol_known {
      cf_assert_symbol($1, SYM_CONSTANT);
      if (!f_valid_set_type(SYM_TYPE($1))) cf_error("%s: set-incompatible type", $1->name);
      $$ = *$1->val;
@@ -719,7 +719,7 @@ var_list: /* EMPTY */ { $$ = NULL; }
  | var_list ',' term { $$ = $3; $$->next = $1; }
 
 function_call:
-   CF_SYM_KNOWN '(' var_list ')' {
+   symbol_known '(' var_list ')' {
      if ($1->class != SYM_FUNCTION)
        cf_error("You can't call something which is not a function. Really.");
 
@@ -743,7 +743,7 @@ function_call:
    }
  ;
 
-symbol_value: CF_SYM_KNOWN
+symbol_value: symbol_known 
   {
     switch ($1->class) {
       case SYM_CONSTANT_RANGE:
@@ -872,7 +872,7 @@ cmd:
  | IF term THEN block ELSE block {
      $$ = f_new_inst(FI_CONDITION, $2, $4, $6);
    }
- | CF_SYM_KNOWN '=' term ';' {
+ | symbol_known '=' term ';' {
      switch ($1->class) {
        case SYM_VARIABLE_RANGE:
 	 $$ = f_new_inst(FI_VAR_SET, $3, $1);
@@ -895,7 +895,7 @@ cmd:
        cf_error( "This static attribute is read-only.");
      $$ = f_new_inst(FI_RTA_SET, $3, $1);
    }
- | UNSET '(' CF_SYM_KNOWN ')' ';' {
+ | UNSET '(' symbol_known ')' ';' {
      if ($3->class != SYM_ATTRIBUTE)
        cf_error("Can't unset %s", $3->name);
      if ($3->attribute->readonly)
@@ -933,11 +933,11 @@ cmd:
       $$ = f_new_inst(FI_SWITCH, $2, build_tree($4));
    }
 
- | CF_SYM_KNOWN '.' EMPTY ';' { $$ = f_generate_empty($1); }
- | CF_SYM_KNOWN '.' PREPEND '(' term ')' ';'   { $$ = f_generate_complex_sym( FI_PATH_PREPEND, $1, $5 ); }
- | CF_SYM_KNOWN '.' ADD '(' term ')' ';'       { $$ = f_generate_complex_sym( FI_CLIST_ADD, $1, $5 ); }
- | CF_SYM_KNOWN '.' DELETE '(' term ')' ';'    { $$ = f_generate_complex_sym( FI_CLIST_DEL, $1, $5 ); }
- | CF_SYM_KNOWN '.' FILTER '(' term ')' ';'    { $$ = f_generate_complex_sym( FI_CLIST_FILTER, $1, $5 ); }
+ | symbol_known '.' EMPTY ';' { $$ = f_generate_empty($1); }
+ | symbol_known '.' PREPEND '(' term ')' ';'   { $$ = f_generate_complex_sym( FI_PATH_PREPEND, $1, $5 ); }
+ | symbol_known '.' ADD '(' term ')' ';'       { $$ = f_generate_complex_sym( FI_CLIST_ADD, $1, $5 ); }
+ | symbol_known '.' DELETE '(' term ')' ';'    { $$ = f_generate_complex_sym( FI_CLIST_DEL, $1, $5 ); }
+ | symbol_known '.' FILTER '(' term ')' ';'    { $$ = f_generate_complex_sym( FI_CLIST_FILTER, $1, $5 ); }
  | BT_ASSERT '(' get_cf_position term get_cf_position ')' ';' { $$ = assert_done($4, $3 + 1, $5 - 1); }
  | BT_CHECK_ASSIGN '(' get_cf_position lvalue get_cf_position ',' term ')' ';' { $$ = assert_assign(&$4, $7, $3 + 1, $5 - 1); }
  ;
@@ -948,7 +948,7 @@ get_cf_position:
 };
 
 lvalue:
-   CF_SYM_KNOWN {
+   symbol_known {
       switch ($1->class) {
 	case SYM_VARIABLE_RANGE:
 	  $$ = (struct f_lval) { .type = F_LVAL_VARIABLE, .sym = $1 };
diff --git a/nest/config.Y b/nest/config.Y
index c2913506..c144f0f3 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -118,11 +118,11 @@ CF_KEYWORDS(IPV4, IPV6, VPN4, VPN6, ROA4, ROA6, FLOW4, FLOW6, SADR, MPLS)
 CF_KEYWORDS(RECEIVE, LIMIT, ACTION, WARN, BLOCK, RESTART, DISABLE, KEEP, FILTERED, RPKI)
 CF_KEYWORDS(PASSWORD, KEY, FROM, PASSIVE, TO, ID, EVENTS, PACKETS, PROTOCOLS, CHANNELS, INTERFACES)
 CF_KEYWORDS(ALGORITHM, KEYED, HMAC, MD5, SHA1, SHA256, SHA384, SHA512, BLAKE2S128, BLAKE2S256, BLAKE2B256, BLAKE2B512)
-CF_KEYWORDS(PRIMARY, STATS, COUNT, BY, FOR, IN, COMMANDS, PREEXPORT, NOEXPORT, EXPORTED, GENERATE)
+CF_KEYWORDS(PRIMARY, STATS, COUNT, FOR, IN, COMMANDS, PREEXPORT, NOEXPORT, EXPORTED, GENERATE)
 CF_KEYWORDS(BGP, PASSWORDS, DESCRIPTION)
 CF_KEYWORDS(RELOAD, IN, OUT, MRTDUMP, MESSAGES, RESTRICT, MEMORY, CLASS, DSCP)
 CF_KEYWORDS(TIMEFORMAT, ISO, SHORT, LONG, ROUTE, PROTOCOL, BASE, LOG, S, MS, US)
-CF_KEYWORDS(GRACEFUL, RESTART, WAIT, MAX, FLUSH, AS)
+CF_KEYWORDS(GRACEFUL, RESTART, WAIT, MAX, AS)
 CF_KEYWORDS(MIN, IDLE, RX, TX, INTERVAL, MULTIPLIER, PASSIVE)
 CF_KEYWORDS(CHECK, LINK)
 CF_KEYWORDS(SORTED, TRIE, MIN, MAX, SETTLE, TIME)
@@ -659,7 +659,7 @@ r_args:
      $$->addr = $3;
      $$->addr_mode = RSD_ADDR_IN;
    }
-| r_args TABLE CF_SYM_KNOWN {
+| r_args TABLE symbol_known {
      cf_assert_symbol($3, SYM_TABLE);
      $$ = $1;
      rt_show_add_table($$, $3->table->table);
@@ -704,7 +704,7 @@ r_args:
      $$ = $1;
      $$->filtered = 1;
    }
- | r_args export_mode CF_SYM_KNOWN {
+ | r_args export_mode symbol_known {
      cf_assert_symbol($3, SYM_PROTO);
      struct proto_config *c = (struct proto_config *) $3->proto;
      $$ = $1;
@@ -721,7 +721,7 @@ r_args:
      $$->export_channel = $3;
      $$->tables_defined_by = RSD_TDB_INDIRECT;
    }
- | r_args PROTOCOL CF_SYM_KNOWN {
+ | r_args PROTOCOL symbol_known {
      cf_assert_symbol($3, SYM_PROTO);
      struct proto_config *c = (struct proto_config *) $3->proto;
      $$ = $1;
diff --git a/proto/babel/config.Y b/proto/babel/config.Y
index 82419b20..a4350eed 100644
--- a/proto/babel/config.Y
+++ b/proto/babel/config.Y
@@ -24,7 +24,7 @@ CF_DECLS
 
 CF_KEYWORDS(BABEL, INTERFACE, METRIC, RXCOST, HELLO, UPDATE, INTERVAL, PORT,
 	TYPE, WIRED, WIRELESS, RX, TX, BUFFER, PRIORITY, LENGTH, CHECK, LINK,
-	NEXT, HOP, IPV4, IPV6, BABEL_METRIC, SHOW, INTERFACES, NEIGHBORS,
+	NEXT, HOP, IPV4, IPV6, SHOW, INTERFACES, NEIGHBORS,
 	ENTRIES, RANDOMIZE, ROUTER, ID, AUTHENTICATION, NONE, MAC, PERMISSIVE)
 
 CF_GRAMMAR
diff --git a/proto/bgp/config.Y b/proto/bgp/config.Y
index db261bbb..b4d8b83f 100644
--- a/proto/bgp/config.Y
+++ b/proto/bgp/config.Y
@@ -19,18 +19,17 @@ CF_DECLS
 
 CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY, KEEPALIVE,
 	MULTIHOP, STARTUP, VIA, NEXT, HOP, SELF, DEFAULT, PATH, METRIC, ERROR,
-	START, DELAY, FORGET, WAIT, ENABLE, DISABLE, AFTER, BGP_PATH,
-	BGP_LOCAL_PREF, BGP_MED, BGP_ORIGIN, BGP_NEXT_HOP, BGP_ATOMIC_AGGR,
-	BGP_AGGREGATOR, BGP_COMMUNITY, BGP_EXT_COMMUNITY, BGP_LARGE_COMMUNITY,
+	START, DELAY, FORGET, WAIT, ENABLE, DISABLE, AFTER,
+	BGP_LOCAL_PREF, BGP_MED, 
 	SOURCE, ADDRESS, PASSWORD, RR, RS, CLIENT, CLUSTER, ID, AS4, ADVERTISE,
 	IPV4, CAPABILITIES, LIMIT, PASSIVE, PREFER, OLDER, MISSING, LLADDR,
-	DROP, IGNORE, ROUTE, REFRESH, INTERPRET, COMMUNITIES, BGP_ORIGINATOR_ID,
-	BGP_CLUSTER_LIST, IGP, TABLE, GATEWAY, DIRECT, RECURSIVE, MED, TTL,
+	DROP, IGNORE, ROUTE, REFRESH, INTERPRET, COMMUNITIES,
+	IGP, TABLE, GATEWAY, DIRECT, RECURSIVE, MED, TTL,
 	SECURITY, DETERMINISTIC, SECONDARY, ALLOW, BFD, ADD, PATHS, RX, TX,
 	GRACEFUL, RESTART, AWARE, CHECK, LINK, PORT, EXTENDED, MESSAGES, SETKEY,
 	STRICT, BIND, CONFEDERATION, MEMBER, MULTICAST, FLOW4, FLOW6, LONG,
 	LIVED, STALE, IMPORT, IBGP, EBGP, MANDATORY, INTERNAL, EXTERNAL, SETS,
-	DYNAMIC, RANGE, NAME, DIGITS, BGP_AIGP, AIGP, ORIGINATE, COST, ENFORCE,
+	DYNAMIC, RANGE, NAME, DIGITS, AIGP, ORIGINATE, COST, ENFORCE,
 	FIRST, FREE, VALIDATE, BASE)
 
 %type <i> bgp_nh
@@ -44,6 +43,8 @@ CF_KEYWORDS(CEASE, PREFIX, LIMIT, HIT, ADMINISTRATIVE, SHUTDOWN, RESET, PEER,
 
 CF_GRAMMAR
 
+toksym: BGP_MED | BGP_LOCAL_PREF ;
+
 proto: bgp_proto '}'  ;
 
 bgp_proto_start: proto_start BGP {
diff --git a/proto/ospf/config.Y b/proto/ospf/config.Y
index 136e1dcb..bc3df8db 100644
--- a/proto/ospf/config.Y
+++ b/proto/ospf/config.Y
@@ -190,7 +190,7 @@ ospf_check_auth(void)
 
 CF_DECLS
 
-CF_KEYWORDS(OSPF, V2, V3, OSPF_METRIC1, OSPF_METRIC2, OSPF_TAG, OSPF_ROUTER_ID)
+CF_KEYWORDS(OSPF, V2, V3)
 CF_KEYWORDS(AREA, NEIGHBORS, RFC1583COMPAT, STUB, TICK, COST, COST2, RETRANSMIT)
 CF_KEYWORDS(HELLO, TRANSMIT, PRIORITY, DEAD, TYPE, BROADCAST, BCAST, DEFAULT)
 CF_KEYWORDS(NONBROADCAST, NBMA, POINTOPOINT, PTP, POINTOMULTIPOINT, PTMP)
diff --git a/proto/radv/config.Y b/proto/radv/config.Y
index f40fdcca..fb68d2e5 100644
--- a/proto/radv/config.Y
+++ b/proto/radv/config.Y
@@ -33,7 +33,7 @@ CF_KEYWORDS(RADV, PREFIX, INTERFACE, MIN, MAX, RA, DELAY, INTERVAL, SOLICITED,
 	RETRANS, TIMER, CURRENT, HOP, LIMIT, DEFAULT, VALID, PREFERRED, MULT,
 	LIFETIME, SKIP, ONLINK, AUTONOMOUS, RDNSS, DNSSL, NS, DOMAIN, LOCAL,
 	TRIGGER, SENSITIVE, PREFERENCE, LOW, MEDIUM, HIGH, PROPAGATE, ROUTE,
-	ROUTES, RA_PREFERENCE, RA_LIFETIME)
+	ROUTES)
 
 CF_ENUM(T_ENUM_RA_PREFERENCE, RA_PREF_, LOW, MEDIUM, HIGH)
 
diff --git a/proto/rip/config.Y b/proto/rip/config.Y
index 234e9029..3c0973b1 100644
--- a/proto/rip/config.Y
+++ b/proto/rip/config.Y
@@ -37,7 +37,7 @@ CF_KEYWORDS(RIP, NG, ECMP, LIMIT, WEIGHT, INFINITY, METRIC, UPDATE, TIMEOUT,
 	    PASSIVE, VERSION, SPLIT, HORIZON, POISON, REVERSE, CHECK, ZERO,
 	    TIME, BFD, AUTHENTICATION, NONE, PLAINTEXT, CRYPTOGRAPHIC, MD5,
 	    TTL, SECURITY, RX, TX, BUFFER, LENGTH, PRIORITY, ONLY, LINK,
-	    DEMAND, CIRCUIT, RIP_METRIC, RIP_TAG)
+	    DEMAND, CIRCUIT)
 
 %type <i> rip_variant rip_auth
 
diff --git a/sysdep/linux/netlink.Y b/sysdep/linux/netlink.Y
index 17e17789..7ba8c7c9 100644
--- a/sysdep/linux/netlink.Y
+++ b/sysdep/linux/netlink.Y
@@ -11,9 +11,6 @@ CF_HDR
 CF_DECLS
 
 CF_KEYWORDS(KERNEL, TABLE, METRIC, NETLINK, RX, BUFFER,
-	    KRT_PREFSRC, KRT_REALM, KRT_SCOPE, KRT_MTU, KRT_WINDOW,
-	    KRT_RTT, KRT_RTTVAR, KRT_SSTRESH, KRT_CWND, KRT_ADVMSS, KRT_REORDERING,
-	    KRT_HOPLIMIT, KRT_INITCWND, KRT_RTO_MIN, KRT_INITRWND, KRT_QUICKACK,
 	    KRT_LOCK_MTU, KRT_LOCK_WINDOW, KRT_LOCK_RTT, KRT_LOCK_RTTVAR,
 	    KRT_LOCK_SSTRESH, KRT_LOCK_CWND, KRT_LOCK_ADVMSS, KRT_LOCK_REORDERING,
 	    KRT_LOCK_HOPLIMIT, KRT_LOCK_RTO_MIN, KRT_FEATURE_ECN, KRT_FEATURE_ALLFRAG)
diff --git a/sysdep/unix/krt.Y b/sysdep/unix/krt.Y
index 9300e9c8..4ce9a328 100644
--- a/sysdep/unix/krt.Y
+++ b/sysdep/unix/krt.Y
@@ -29,7 +29,7 @@ kif_set_preferred(ip_addr ip)
 
 CF_DECLS
 
-CF_KEYWORDS(KERNEL, PERSIST, SCAN, TIME, LEARN, DEVICE, ROUTES, GRACEFUL, RESTART, KRT_SOURCE, KRT_METRIC, MERGE, PATHS)
+CF_KEYWORDS(KERNEL, PERSIST, SCAN, TIME, LEARN, DEVICE, ROUTES, GRACEFUL, RESTART, MERGE, PATHS)
 CF_KEYWORDS(INTERFACE, PREFERRED)
 
 %type <i> kern_mp_limit