Example #1
0
static bool
parse_action(struct action_context *ctx)
{
    if (ctx->lexer->token.type != LEX_T_ID) {
        action_syntax_error(ctx, NULL);
        return false;
    }

    enum lex_type lookahead = lexer_lookahead(ctx->lexer);
    if (lookahead == LEX_T_EQUALS || lookahead == LEX_T_EXCHANGE
        || lookahead == LEX_T_LSQUARE) {
        parse_set_action(ctx);
    } else if (lexer_match_id(ctx->lexer, "next")) {
        parse_next_action(ctx);
    } else if (lexer_match_id(ctx->lexer, "output")) {
        emit_resubmit(ctx, ctx->ap->output_ptable);
    } else if (lexer_match_id(ctx->lexer, "ip.ttl")) {
        if (lexer_match(ctx->lexer, LEX_T_DECREMENT)) {
            add_prerequisite(ctx, "ip");
            ofpact_put_DEC_TTL(ctx->ofpacts);
        } else {
            action_syntax_error(ctx, "expecting `--'");
        }
    } else if (lexer_match_id(ctx->lexer, "ct_next")) {
        emit_ct(ctx, true, false);
    } else if (lexer_match_id(ctx->lexer, "ct_commit")) {
        emit_ct(ctx, false, true);
    } else {
        action_syntax_error(ctx, "expecting action");
    }
    if (!lexer_match(ctx->lexer, LEX_T_SEMICOLON)) {
        action_syntax_error(ctx, "expecting ';'");
    }
    return !ctx->error;
}
Example #2
0
static void
parse_actions(struct action_context *ctx)
{
    /* "drop;" by itself is a valid (empty) set of actions, but it can't be
     * combined with other actions because that doesn't make sense. */
    if (ctx->lexer->token.type == LEX_T_ID
        && !strcmp(ctx->lexer->token.s, "drop")
        && lexer_lookahead(ctx->lexer) == LEX_T_SEMICOLON) {
        lexer_get(ctx->lexer);  /* Skip "drop". */
        lexer_get(ctx->lexer);  /* Skip ";". */
        if (ctx->lexer->token.type != LEX_T_END) {
            action_syntax_error(ctx, "expecting end of input");
        }
        return;
    }

    while (ctx->lexer->token.type != LEX_T_END) {
        if (ctx->lexer->token.type != LEX_T_ID) {
            action_syntax_error(ctx, NULL);
            break;
        }

        enum lex_type lookahead = lexer_lookahead(ctx->lexer);
        if (lookahead == LEX_T_EQUALS || lookahead == LEX_T_EXCHANGE
            || lookahead == LEX_T_LSQUARE) {
            parse_set_action(ctx);
        } else if (lexer_match_id(ctx->lexer, "next")) {
            parse_next_action(ctx);
        } else if (lexer_match_id(ctx->lexer, "output")) {
            emit_resubmit(ctx, ctx->output_ptable);
        } else if (lexer_match_id(ctx->lexer, "ip4.ttl")) {
            if (lexer_match(ctx->lexer, LEX_T_DECREMENT)) {
                struct expr *e = expr_parse_string("ip4", ctx->symtab,
                                                   &ctx->error);
                ctx->prereqs = expr_combine(EXPR_T_AND, ctx->prereqs, e);
                ofpact_put_DEC_TTL(ctx->ofpacts);
            } else {
                action_syntax_error(ctx, "expecting `--'");
            }
        } else if (lexer_match_id(ctx->lexer, "ct_next")) {
            emit_ct(ctx, true, false);
        } else if (lexer_match_id(ctx->lexer, "ct_commit")) {
            emit_ct(ctx, false, true);
        } else {
            action_syntax_error(ctx, "expecting action");
        }
        if (!lexer_match(ctx->lexer, LEX_T_SEMICOLON)) {
            action_syntax_error(ctx, "expecting ';'");
        }
        if (ctx->error) {
            return;
        }
    }
}