From 9654b1416ee82fc7f9b09beb7cb284f7775f280b Mon Sep 17 00:00:00 2001 From: "Ondrej Zajicek (work)" Date: Wed, 9 Mar 2022 02:32:29 +0100 Subject: [PATCH] Filter: Improve handling of stack frames in filter bytecode 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. --- conf/confbase.Y | 4 ++-- filter/config.Y | 14 +++++++------- filter/decl.m4 | 6 ++++-- filter/f-inst.c | 8 ++++---- filter/f-inst.h | 7 ++++--- filter/f-util.c | 2 +- filter/filter.c | 3 +-- nest/config.Y | 4 ++-- proto/static/config.Y | 2 +- 9 files changed, 26 insertions(+), 24 deletions(-) diff --git a/conf/confbase.Y b/conf/confbase.Y index aa35f882..4599521c 100644 --- a/conf/confbase.Y +++ b/conf/confbase.Y @@ -153,14 +153,14 @@ conf: definition ; definition: DEFINE symbol '=' term ';' { struct f_val *val = cfg_allocz(sizeof(struct f_val)); - if (f_eval(f_linearize($4), cfg_mem, val) > F_RETURN) cf_error("Runtime error"); + if (f_eval(f_linearize($4, 1), cfg_mem, val) > F_RETURN) cf_error("Runtime error"); cf_define_symbol($2, SYM_CONSTANT | val->type, val, val); } ; expr: NUM - | '(' term ')' { $$ = f_eval_int(f_linearize($2)); } + | '(' term ')' { $$ = f_eval_int(f_linearize($2, 1)); } | CF_SYM_KNOWN { if ($1->class != (SYM_CONSTANT | T_INT)) cf_error("Number constant expected"); $$ = SYM_VAL($1).i; } diff --git a/filter/config.Y b/filter/config.Y index a3acf245..b67ca925 100644 --- a/filter/config.Y +++ b/filter/config.Y @@ -329,7 +329,7 @@ filter_def: conf: filter_eval ; filter_eval: - EVAL term { f_eval_int(f_linearize($2)); } + EVAL term { f_eval_int(f_linearize($2, 1)); } ; conf: custom_attr ; @@ -453,7 +453,7 @@ where_filter: function_body: function_vars '{' cmds '}' { - $$ = f_linearize($3); + $$ = f_linearize($3, 0); $$->vars = $1; } ; @@ -537,7 +537,7 @@ set_atom: | VPN_RD { $$.type = T_RD; $$.val.ec = $1; } | ENUM { $$.type = pair_a($1); $$.val.i = pair_b($1); } | '(' term ')' { - if (f_eval(f_linearize($2), cfg_mem, &($$)) > F_RETURN) cf_error("Runtime error"); + if (f_eval(f_linearize($2, 1), cfg_mem, &($$)) > F_RETURN) cf_error("Runtime error"); if (!f_valid_set_type($$.type)) cf_error("Set-incompatible type"); } | CF_SYM_KNOWN { @@ -549,13 +549,13 @@ set_atom: switch_atom: NUM { $$.type = T_INT; $$.val.i = $1; } - | '(' term ')' { $$.type = T_INT; $$.val.i = f_eval_int(f_linearize($2)); } + | '(' term ')' { $$.type = T_INT; $$.val.i = f_eval_int(f_linearize($2, 1)); } | fipa { $$ = $1; } | ENUM { $$.type = pair_a($1); $$.val.i = pair_b($1); } ; cnum: - term { $$ = f_eval_int(f_linearize($1)); } + term { $$ = f_eval_int(f_linearize($1, 1)); } pair_item: '(' cnum ',' cnum ')' { $$ = f_new_pair_item($2, $2, $4, $4); } @@ -642,7 +642,7 @@ switch_body: /* EMPTY */ { $$ = NULL; } | switch_body switch_items ':' cmds { /* Fill data fields */ struct f_tree *t; - struct f_line *line = f_linearize($4); + struct f_line *line = f_linearize($4, 0); for (t = $2; t; t = t->left) t->data = line; $$ = f_merge_items($1, $2); @@ -651,7 +651,7 @@ switch_body: /* EMPTY */ { $$ = NULL; } struct f_tree *t = f_new_tree(); t->from.type = t->to.type = T_VOID; t->right = t; - t->data = f_linearize($3); + t->data = f_linearize($3, 0); $$ = f_merge_items($1, t); } ; diff --git a/filter/decl.m4 b/filter/decl.m4 index 3d118e34..4c56cd9c 100644 --- a/filter/decl.m4 +++ b/filter/decl.m4 @@ -216,7 +216,7 @@ whati->f$1 = f$1; FID_DUMP_BODY()m4_dnl f_dump_line(item->fl$1, indent + 1); FID_LINEARIZE_BODY()m4_dnl -item->fl$1 = f_linearize(whati->f$1); +item->fl$1 = f_linearize(whati->f$1, $2); FID_SAME_BODY()m4_dnl if (!f_same(f1->fl$1, f2->fl$1)) return 0; FID_ITERATE_BODY()m4_dnl @@ -568,7 +568,7 @@ FID_WR_PUT(8) } struct f_line * -f_linearize_concat(const struct f_inst * const inst[], uint count) +f_linearize_concat(const struct f_inst * const inst[], uint count, uint results) { uint len = 0; for (uint i=0; ilen = linearize(out, inst[i], out->len); + out->results = results; + #ifdef LOCAL_DEBUG f_dump_line(out, 0); #endif diff --git a/filter/f-inst.c b/filter/f-inst.c index e75b5e01..5b8310c3 100644 --- a/filter/f-inst.c +++ b/filter/f-inst.c @@ -64,7 +64,7 @@ * m4_dnl ARG_ANY(num); argument with no type check accessible by v1, v2, v3 * m4_dnl ARG_TYPE(num, type); just declare the type of argument * m4_dnl VARARG; variable-length argument list; accessible by vv(i) and whati->varcount - * m4_dnl LINE(num, unused); this argument has to be converted to its own f_line + * m4_dnl LINE(num, out); this argument has to be converted to its own f_line * m4_dnl SYMBOL; symbol handed from config * m4_dnl STATIC_ATTR; static attribute definition * m4_dnl DYNAMIC_ATTR; dynamic attribute definition @@ -298,7 +298,7 @@ RESULT_TYPE(T_BOOL); if (v1.val.i) - LINE(2,0); + LINE(2,1); else RESULT_VAL(v1); } @@ -308,7 +308,7 @@ RESULT_TYPE(T_BOOL); if (!v1.val.i) - LINE(2,0); + LINE(2,1); else RESULT_VAL(v1); } @@ -536,7 +536,7 @@ if (v1.val.i) LINE(2,0); else - LINE(3,1); + LINE(3,0); } INST(FI_PRINT, 0, 0) { diff --git a/filter/f-inst.h b/filter/f-inst.h index 58563c79..e35f71c6 100644 --- a/filter/f-inst.h +++ b/filter/f-inst.h @@ -46,14 +46,15 @@ struct f_line { uint len; /* Line length */ u8 args; /* Function: Args required */ u8 vars; + u8 results; /* Results left on stack: cmd -> 0, term -> 1 */ struct f_arg *arg_list; struct f_line_item items[0]; /* The items themselves */ }; /* Convert the f_inst infix tree to the f_line structures */ -struct f_line *f_linearize_concat(const struct f_inst * const inst[], uint count); -static inline struct f_line *f_linearize(const struct f_inst *root) -{ return f_linearize_concat(&root, 1); } +struct f_line *f_linearize_concat(const struct f_inst * const inst[], uint count, uint results); +static inline struct f_line *f_linearize(const struct f_inst *root, uint results) +{ return f_linearize_concat(&root, 1, results); } void f_dump_line(const struct f_line *, uint indent); diff --git a/filter/f-util.c b/filter/f-util.c index 410999a6..fdb314b5 100644 --- a/filter/f-util.c +++ b/filter/f-util.c @@ -37,7 +37,7 @@ struct filter *f_new_where(struct f_inst *where) f_new_inst(FI_DIE, F_REJECT)); struct filter *f = cfg_allocz(sizeof(struct filter)); - f->root = f_linearize(cond); + f->root = f_linearize(cond, 0); return f; } diff --git a/filter/filter.c b/filter/filter.c index e505d570..20a380dc 100644 --- a/filter/filter.c +++ b/filter/filter.c @@ -215,8 +215,7 @@ interpret(struct filter_state *fs, const struct f_line *line, struct f_val *val) } /* End of current line. Drop local variables before exiting. */ - fstk->vcnt -= curline.line->vars; - fstk->vcnt -= curline.line->args; + fstk->vcnt = curline.ventry + curline.line->results; fstk->ecnt--; } diff --git a/nest/config.Y b/nest/config.Y index 72bc7930..bb6c4352 100644 --- a/nest/config.Y +++ b/nest/config.Y @@ -165,7 +165,7 @@ rtrid: idval: NUM { $$ = $1; } - | '(' term ')' { $$ = f_eval_int(f_linearize($2)); } + | '(' term ')' { $$ = f_eval_int(f_linearize($2, 1)); } | IP4 { $$ = ip4_to_u32($1); } | CF_SYM_KNOWN { if ($1->class == (SYM_CONSTANT | T_INT) || $1->class == (SYM_CONSTANT | T_QUAD)) @@ -858,7 +858,7 @@ CF_CLI(DUMP FILTER ALL,,, [[Dump all filters in linearized form]]) { filters_dump_all(); cli_msg(0, ""); } ; CF_CLI(EVAL, term, , [[Evaluate an expression]]) -{ cmd_eval(f_linearize($2)); } ; +{ cmd_eval(f_linearize($2, 1)); } ; CF_CLI_HELP(ECHO, ..., [[Control echoing of log messages]]) CF_CLI(ECHO, echo_mask echo_size, (all | off | { debug|trace|info|remote|warning|error|auth [, ...] }) [], [[Control echoing of log messages]]) { diff --git a/proto/static/config.Y b/proto/static/config.Y index 41e10dbf..9d26ee82 100644 --- a/proto/static/config.Y +++ b/proto/static/config.Y @@ -40,7 +40,7 @@ static_route_finish(void) if (net_type_match(this_srt->net, NB_DEST) == !this_srt->dest) cf_error("Unexpected or missing nexthop/type"); - this_srt->cmds = f_linearize(this_srt_cmds); + this_srt->cmds = f_linearize(this_srt_cmds, 0); } CF_DECLS