postconf_dbms.c

[詳解]

/*++
/* NAME
/*  postconf_dbms 3
/* SUMMARY
/*  legacy support for database-defined main.cf parameter names
/* SYNOPSIS
/*  #include <postconf.h>
/*
/*  void    pcf_register_dbms_parameters(param_value, flag_parameter,
/*                  local_scope)
/*  const char *param_value;
/*  const char *(flag_parameter) (const char *, int, PCF_MASTER_ENT *);
/*  PCF_MASTER_ENT *local_scope;
/* DESCRIPTION
/*  This module implements legacy support for database configuration
/*  where main.cf parameter names are generated by prepending
/*  the database name to a database-defined suffix.
/*
/*  Arguments:
/* .IP param_value
/*  A parameter value to be searched for "type:table" strings.
/*  When a database type is found that supports legacy-style
/*  configuration, the table name is combined with each of the
/*  database-defined suffixes to generate candidate parameter
/*  names for that database type; if the table name specifies
/*  a client configuration file, that file is scanned for unused
/*  parameter settings.
/* .IP flag_parameter
/*  A function that takes as arguments a candidate parameter
/*  name, parameter flags, and a PCF_MASTER_ENT pointer.  The
/*  function will flag the parameter as "used" if it has a
/*  "name=value" entry in the local or global namespace.
/* .IP local_scope
/*  The local namespace.
/* DIAGNOSTICS
/*  No explicit diagnostics.
/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*
/*  Wietse Venema
/*  Google, Inc.
/*  111 8th Avenue
/*  New York, NY 10011, USA
/*--*/

/* System library. */

#include <sys_defs.h>
#include <sys/stat.h>
#include <errno.h>
#include <string.h>

/* Utility library. */

#include <stringops.h>
#include <split_at.h>
#include <mac_expand.h>
#include <dict.h>
#include <msg.h>
#include <mymalloc.h>

/* Global library. */

#include <mail_conf.h>
#include <mail_params.h>
#include <dict_ht.h>
#include <dict_proxy.h>
#include <dict_ldap.h>
#include <dict_mysql.h>
#include <dict_pgsql.h>
#include <dict_sqlite.h>
#include <dict_memcache.h>

/* Application-specific. */

#include <postconf.h>

 /*
  * SLMs.
  */
#define STR(x)  vstring_str(x)

#ifdef LEGACY_DBMS_SUPPORT

 /*
  * The legacy database interface automagically instantiates a list of
  * parameters by prepending the table name to database-specific suffixes.
  */

/* See ldap_table(5). */

static const char *pcf_ldap_suffixes[] = {
#include "pcf_ldap_suffixes.h"
    0,
};

/* See mysql_table(5). */

static const char *pcf_mysql_suffixes[] = {
#include "pcf_mysql_suffixes.h"
    0,
};

/* See pgsql_table(5). */

static const char *pcf_pgsql_suffixes[] = {
#include "pcf_pgsql_suffixes.h"
    0,
};

/* See sqlite_table(5). */

static const char *pcf_sqlite_suffixes[] = {
#include "pcf_sqlite_suffixes.h"
    0,
};

/* See memcache_table(5). */

static const char *pcf_memcache_suffixes[] = {
#include "pcf_memcache_suffixes.h"
    0,
};

 /*
  * Bundle up the database types and their suffix lists.
  */
typedef struct {
    const char *db_type;
    const char **db_suffixes;
} PCF_DBMS_INFO;

static const PCF_DBMS_INFO pcf_dbms_info[] = {
    DICT_TYPE_LDAP, pcf_ldap_suffixes,
    DICT_TYPE_MYSQL, pcf_mysql_suffixes,
    DICT_TYPE_PGSQL, pcf_pgsql_suffixes,
    DICT_TYPE_SQLITE, pcf_sqlite_suffixes,
    DICT_TYPE_MEMCACHE, pcf_memcache_suffixes,
    0,
};

/* pcf_check_dbms_client - look for unused names in client configuration */

static void pcf_check_dbms_client(const PCF_DBMS_INFO *dp, const char *cf_file)
{
    DICT   *dict;
    VSTREAM *fp;
    const char **cpp;
    const char *name;
    const char *value;
    char   *dict_spec;
    int     dir;

    /*
     * We read each database client configuration file into its own
     * dictionary, and nag only the first time that a file is visited.
     */
    dict_spec = concatenate(dp->db_type, ":", cf_file, (char *) 0);
    if ((dict = dict_handle(dict_spec)) == 0) {
    struct stat st;

    /*
     * Populate the dictionary with settings in this database client
     * configuration file. Don't die if a file can't be opened - some
     * files may contain passwords and should not be world-readable.
     * Note: dict_load_fp() nags about duplicate pameter settings.
     */
    dict = dict_ht_open(dict_spec, O_CREAT | O_RDWR, 0);
    dict_register(dict_spec, dict);
    if ((fp = vstream_fopen(cf_file, O_RDONLY, 0)) == 0) {
        if (errno != EACCES)
        msg_warn("open \"%s\" configuration \"%s\": %m",
             dp->db_type, cf_file);
        myfree(dict_spec);
        return;
    }
    if (fstat(vstream_fileno(fp), &st) == 0 && !S_ISREG(st.st_mode)) {
        msg_warn("open \"%s\" configuration \"%s\": not a regular file",
             dp->db_type, cf_file);
        myfree(dict_spec);
        (void) vstream_fclose(fp);
        return;
    }
    dict_load_fp(dict_spec, fp);
    if (vstream_fclose(fp)) {
        msg_warn("read \"%s\" configuration \"%s\": %m",
             dp->db_type, cf_file);
        myfree(dict_spec);
        return;
    }

    /*
     * Remove all known database client parameters from this dictionary,
     * then report the remaining ones as "unused". We use ad-hoc logging
     * code, because a database client parameter namespace is unlike the
     * parameter namespaces in main.cf or master.cf.
     */
    for (cpp = dp->db_suffixes; *cpp; cpp++)
        (void) dict_del(dict, *cpp);
    for (dir = DICT_SEQ_FUN_FIRST;
         dict->sequence(dict, dir, &name, &value) == DICT_STAT_SUCCESS;
         dir = DICT_SEQ_FUN_NEXT)
        msg_warn("%s: unused parameter: %s=%s", dict_spec, name, value);
    }
    myfree(dict_spec);
}

/* pcf_register_dbms_helper - parse one possible database type:name */

static void pcf_register_dbms_helper(char *str_value,
         const char *(flag_parameter) (const char *, int, PCF_MASTER_ENT *),
                             PCF_MASTER_ENT *local_scope)
{
    const PCF_DBMS_INFO *dp;
    char   *db_type;
    char   *prefix;
    static VSTRING *candidate = 0;
    const char **cpp;
    char   *err;

    /*
     * Naive parsing. We don't really know if this substring specifies a
     * database or some other text.
     */
    while ((db_type = mystrtokq(&str_value, CHARS_COMMA_SP, CHARS_BRACE)) != 0) {

    /*
     * Skip over "proxy:" maptypes, to emulate the proxymap(8) server's
     * behavior when opening a local database configuration file.
     */
    while ((prefix = split_at(db_type, ':')) != 0
           && strcmp(db_type, DICT_TYPE_PROXY) == 0)
        db_type = prefix;

    if (prefix == 0)
        continue;

    /*
     * Look for database:prefix where the prefix is an absolute pathname.
     * Then, report unknown database client configuration parameters.
     * 
     * XXX What about a pathname beginning with '.'? This supposedly is
     * relative to the queue directory, which is the default directory
     * for all Postfix daemon processes. This would also have to handle
     * the case that the queue is not yet created.
     */
    if (*prefix == '/') {
        for (dp = pcf_dbms_info; dp->db_type != 0; dp++) {
        if (strcmp(db_type, dp->db_type) == 0) {
            pcf_check_dbms_client(dp, prefix);
            break;
        }
        }
        continue;
    }

    /*
     * Look for database:prefix where the prefix is not a pathname and
     * the database is a known type. Synthesize candidate parameter names
     * from the user-defined prefix and from the database-defined suffix
     * list, and see if those parameters have a "name=value" entry in the
     * local or global namespace.
     */
    if (*prefix != '.') {
        if (*prefix == CHARS_BRACE[0]) {
        if ((err = extpar(&prefix, CHARS_BRACE, EXTPAR_FLAG_NONE)) != 0) {
            /* XXX Encapsulate this in pcf_warn() function. */
            if (local_scope)
            msg_warn("%s:%s: %s",
                 MASTER_CONF_FILE, local_scope->name_space,
                 err);
            else
            msg_warn("%s: %s", MAIN_CONF_FILE, err);
            myfree(err);
        }
        pcf_register_dbms_helper(prefix, flag_parameter,
                     local_scope);
        } else {
        for (dp = pcf_dbms_info; dp->db_type != 0; dp++) {
            if (strcmp(db_type, dp->db_type) == 0) {
            for (cpp = dp->db_suffixes; *cpp; cpp++) {
                vstring_sprintf(candidate ? candidate :
                        (candidate = vstring_alloc(30)),
                        "%s_%s", prefix, *cpp);
                flag_parameter(STR(candidate),
                  PCF_PARAM_FLAG_DBMS | PCF_PARAM_FLAG_USER,
                       local_scope);
            }
            break;
            }
        }
        }
    }
    }
}

/* pcf_register_dbms_parameters - look for database_type:prefix_name */

void    pcf_register_dbms_parameters(const char *param_value,
         const char *(flag_parameter) (const char *, int, PCF_MASTER_ENT *),
                             PCF_MASTER_ENT *local_scope)
{
    char   *bufp;
    static VSTRING *buffer = 0;

    /*
     * XXX This does not examine both sides of conditional macro expansion,
     * and may expand the "wrong" conditional macros. This is the best we can
     * do for legacy database configuration support.
     */
    if (buffer == 0)
    buffer = vstring_alloc(100);
    bufp = pcf_expand_parameter_value(buffer, PCF_SHOW_EVAL, param_value,
                      local_scope);
    pcf_register_dbms_helper(bufp, flag_parameter, local_scope);
}

#endif