From 42ad13ca342ae47b39d9a825ef4cd4341a438fd6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Niels=20M=C3=B6ller?= Date: Mon, 4 Mar 2002 21:39:57 +0100 Subject: [PATCH] New files. A lexer and a recursive-descent parser for config files. Rev: src/parse_config.c:1.1 Rev: src/parse_config.h:1.1 --- src/parse_config.c | 356 +++++++++++++++++++++++++++++++++++++++++++++ src/parse_config.h | 55 +++++++ 2 files changed, 411 insertions(+) create mode 100644 src/parse_config.c create mode 100644 src/parse_config.h diff --git a/src/parse_config.c b/src/parse_config.c new file mode 100644 index 00000000..ee17f764 --- /dev/null +++ b/src/parse_config.c @@ -0,0 +1,356 @@ +/* parse_config.c + * + * $id$ + * + * Parsing of configuration files. */ + +#include "parse_config.h" + +#include "format.h" +#include "parse.h" +#include "werror.h" +#include "xalloc.h" + +#include +#include + +#define BUFFER (&(self->buffer)) + +#include "parse_macros.h" + +#include "parse_config.c.x" + +/* GABA: + (class + (name config_setting) + (vars + (next object config_setting) + (type . "enum config_type") + (value string))) +*/ + +/* GABA: + (class + (name config_host) + (vars + (next object config_host) + (name string) + (settings object config_setting))) +*/ + +/* GABA: + (class + (name config_group) + (vars + (next object config_group) + (name string) + ; Group settings + (settings object config_setting) + (hosts object config_host))) +*/ + +enum token_type + { TOK_EOF, TOK_BEGIN_GROUP, TOK_END_GROUP, TOK_STRING, TOK_ERROR }; + +/* FIXME: Keep track of linenumber */ +struct tokenizer +{ + struct simple_buffer buffer; + enum token_type type; + unsigned token_length; + const char *token; +}; + +static void +tokenizer_init(struct tokenizer *self, + unsigned length, const unsigned char *data) +{ + simple_buffer_init(&self->buffer, length, data); +} + +static enum token_type +next_token(struct tokenizer *self) +{ + /* FIXME: Share a char-class table with sexp_parser.c. */ + static const char char_class[0x100] = + { + /* HT, LF, VT, FF, CR */ + 0,0,0,0,0,0,0,0,0,1,1,1,1,1,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + /* SPACE */ + 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + /* '{', '}' */ + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,2,0,2,0,0, + + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + }; +#define IS_SPACE(c) (char_class[c] & 1) +#define IS_SEPARATOR(c) (char_class[c] & 3) + while (LEFT && IS_SPACE(*HERE)) + ADVANCE(1); + + if (!LEFT) + self->type = TOK_EOF; + else switch(*HERE) + { + case '{': + self->type = TOK_BEGIN_GROUP; + ADVANCE(1); + break; + case '}': + self->type = TOK_END_GROUP; + ADVANCE(1); + break; + default: + { + unsigned i; + self->token = HERE; + + for (i = 0; itoken_length = i; + ADVANCE(i); + } + } + return self->type; +} + +/* Can only be called if self->type == TOK_STRING */ +static int +looking_at(struct tokenizer *self, const char *word) +{ + unsigned length = strlen(word); + + return (length == self->token_length + && !memcmp(self->token, word, length)); +} + +static struct lsh_string * +parse_word(struct tokenizer *self) +{ + struct lsh_string *s; + if (self->type != TOK_STRING) + return NULL; + + s = ssh_format("%ls", self->token_length, self->token); + next_token(self); + return s; +} + +static struct config_setting * +parse_setting(struct tokenizer *self, struct config_setting *settings) +{ + struct lsh_string *s; + enum config_type type; + if (looking_at(self, "address")) + type = CONFIG_ADDRESS; + else if (looking_at(self, "user")) + type = CONFIG_USER; + else + return NULL; + + next_token(self); + s = parse_word(self); + if (!s) + return NULL; + + { + /* Push new object on the list */ + NEW(config_setting, n); + n->next = settings; + settings = n; + } + + settings->type = type; + settings->value = s; + + return settings; +} + +static struct config_setting * +parse_host_settings(struct tokenizer *self) +{ + struct config_setting *settings = NULL; + + while (self->type == TOK_STRING) + { + settings = parse_setting(self, settings); + if (!settings) + return NULL; + } + return settings; +} + +static int +parse_token(struct tokenizer *self, enum token_type type) +{ + if (self->type == type) + { + next_token(self); + return 1; + } + else + return 0; +} + +static struct config_host * +parse_hosts(struct tokenizer *self, struct config_host *hosts) +{ + while (self->type == TOK_STRING) + { + { + /* Push new object on the list */ + NEW(config_host, n); + n->next = hosts; + hosts = n; + } + hosts->name = parse_word(self); + assert(hosts->name); + if (self->type == TOK_BEGIN_GROUP) + { + hosts->settings = parse_host_settings(self); + if (!parse_token(self, TOK_END_GROUP)) + return NULL; + } + } + return hosts; +} + +#if 0 +static struct config_setting * +parse_group(struct tokenizer *self) +{ + struct config_setting *settings = NULL; + + while (self->type == TOK_STRING) + { + struct lsh_string *s; + { + /* Push new object on the list */ + NEW(config_setting, n); + n->next = settings; + settings = n; + } + if (looking_at(self, "address")) + settings->type = CONFIG_ADDRESS; + else if (looking_at(self, "user")) + settings->type = CONFIG_USER; + else if (looking_at(self, "hosts")) + + else + return NULL; + + next_token(self); + if (self->type != TOK_STRING) + return NULL; + + s = parse_word(self); + if (!s) + return NULL; + settings->value = s; + } + return settings; +} +#endif + +static struct config_group * +parse_groups(struct tokenizer *self) +{ + struct config_group *groups = NULL; + while (self->type != TOK_EOF) + { + { + /* Push new object on the list */ + NEW(config_group, n); + n->next = groups; + groups = n; + } + /* Name is optional */ + groups->name = parse_word(self); + groups->settings = NULL; + groups->hosts = NULL; + + if (!parse_token(self, TOK_BEGIN_GROUP)) + return NULL; + + while (self->type != TOK_END_GROUP) + { + if (looking_at(self, "hosts")) + { + groups->hosts = parse_hosts(self, groups->hosts); + if (!groups->hosts) + return NULL; + } + else + { + groups->settings = parse_setting(self, groups->settings); + if (!groups->settings) + return NULL; + } + } + if (!parse_token(self, TOK_END_GROUP)) + return NULL; + } + return groups; +} + +struct config_group * +config_parse_string(const struct lsh_string *s) +{ + struct tokenizer t; + tokenizer_init(&t, s->length, s->data); + next_token(&t); + + return parse_groups(&t); +} + + +int +config_lookup_host(const struct config_group *groups, + const char *host, + struct config_match *match) +{ + unsigned length = strlen(host); + int found = 0; + + for (; groups; groups = groups->next) + { + const struct config_host *hosts; + for (hosts = groups->hosts; hosts; hosts = hosts->next) + if (lsh_string_eq_l(hosts->name, length, host)) + { + if (found) + { + werror("Ambigous host name `%z' in configuration.\n"); + return 1; + } + else + { + found = 1; + match->group = groups->settings; + match->host = hosts->settings; + } + } + } + return found; +} + +const struct lsh_string * +config_get_setting(enum config_type type, + const struct config_match *match) +{ + const struct config_setting *p; + + for (p = match->host; p; p = p->next) + if (p->type == type) + return p->value; + + for (p = match->group; p; p = p->next) + if (p->type == type) + return p->value; + + return NULL; +} diff --git a/src/parse_config.h b/src/parse_config.h new file mode 100644 index 00000000..07aef6e3 --- /dev/null +++ b/src/parse_config.h @@ -0,0 +1,55 @@ +/* parse_config.h + * + * $id$ + * + * Parsing of configuration files. */ + +/* lsh, an implementation of the ssh protocol + * + * Copyright (C) 2002 Niels Möller + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef LSH_PARSE_CONFIG_H_INCLUDED +#define LSH_PARSE_CONFIG_H_INCLUDED + +#include "lsh.h" + +enum config_type + { CONFIG_ADDRESS, CONFIG_USER }; + +struct config_setting; +struct config_group; + +struct config_group * +config_parse_string(const struct lsh_string *s); + +struct config_match +{ + const struct config_setting *group; + const struct config_setting *host; +}; + +int +config_lookup_host(const struct config_group *config, + const char *host, + struct config_match *match); + +const struct lsh_string * +config_get_setting(enum config_type type, + const struct config_match *match); + +#endif /* LSH_PARSE_CONFIG_H_INCLUDED */ -- GitLab