NetBSD/gnu/dist/postfix/util/dict_mysql.c
2000-05-13 14:50:45 +00:00

555 lines
18 KiB
C

/*++
/* NAME
/* dict_mysql 3
/* SUMMARY
/* dictionary manager interface to db files
/* SYNOPSIS
/* #include <dict.h>
/* #include <dict_mysql.h>
/*
/* DICT *dict_mysql_open(name, dummy, unused_dict_flags)
/* const char *name;
/* int dummy;
/* int unused_dict_flags;
/* DESCRIPTION
/* dict_mysql_open() creates a dictionary of type 'mysql'. This
/* dictionary is an interface for the postfix key->value mappings
/* to mysql. The result is a pointer to the installed dictionary,
/* or a null pointer in case of problems.
/*
/* The mysql dictionary can manage multiple connections to different
/* sql servers on different hosts. It assumes that the underlying data
/* on each host is identical (mirrored) and maintains one connection
/* at any given time. If any connection fails, any other available
/* ones will be opened and used. The intent of this feature is to eliminate
/* a single point of failure for mail systems that would otherwise rely
/* on a single mysql server.
/*
/* Arguments:
/* .IP name
/* The path of the MySQL configuration file. The file encodes a number of
/* pieces of information: username, password, databasename, table,
/* select_field, where_field, and hosts. For example, if you want the map to
/* reference databases of the name "your_db" and execute a query like this:
/* select forw_addr from aliases where alias like '<some username>' against
/* any database called "vmailer_info" located on hosts host1.some.domain and
/* host2.some.domain, logging in as user "vmailer" and password "passwd" then
/* the configuration file should read:
/*
/* user = vmailer
/* password = passwd
/* DBname = vmailer_info
/* table = aliases
/* select_field = forw_addr
/* where_field = alias
/* hosts = host1.some.domain host2.some.domain
/*
/* .IP other_name
/* reference for outside use.
/* .IP unusued_flags
/* unused flags
/* SEE ALSO
/* dict(3) generic dictionary manager
/* AUTHOR(S)
/* Scott Cotton
/* IC Group, Inc.
/* scott@icgroup.com
/*
/* Joshua Marcus
/* IC Group, Inc.
/* josh@icgroup.com
/*--*/
/* System library. */
#include "sys_defs.h"
#ifdef HAS_MYSQL
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <syslog.h>
#include <time.h>
/* Utility library. */
#include "dict.h"
#include "msg.h"
#include "mymalloc.h"
#include "dict_mysql.h"
#include "argv.h"
#include "vstring.h"
/* external declarations */
extern int dict_errno;
/* need some structs to help organize things */
typedef struct {
MYSQL db;
char *hostname;
int stat; /* STATUNTRIED | STATFAIL | STATCUR */
time_t ts; /* used for attempting reconnection
* every so often if a host is down */
} HOST;
typedef struct {
int len_hosts; /* number of hosts */
HOST *db_hosts; /* the hosts on which the databases
* reside */
} PLMYSQL;
typedef struct {
char *username;
char *password;
char *dbname;
char *table;
char *select_field;
char *where_field;
char *additional_conditions;
char **hostnames;
int len_hosts;
} MYSQL_NAME;
typedef struct {
DICT dict;
PLMYSQL *pldb;
MYSQL_NAME *name;
} DICT_MYSQL;
/* internal function declarations */
static PLMYSQL *plmysql_init(char *hostnames[], int);
static MYSQL_RES *plmysql_query(PLMYSQL *, const char *, char *, char *, char *);
static void plmysql_dealloc(PLMYSQL *);
static void plmysql_down_host(HOST *);
static void plmysql_connect_single(HOST *, char *, char *, char *);
static int plmysql_ready_reconn(HOST);
static void dict_mysql_update(DICT *, const char *, const char *);
static const char *dict_mysql_lookup(DICT *, const char *);
DICT *dict_mysql_open(const char *, int, int);
static void dict_mysql_close(DICT *);
static MYSQL_NAME *mysqlname_parse(const char *);
static HOST host_init(char *);
/**********************************************************************
* public interface dict_mysql_lookup
* find database entry return 0 if no alias found, set dict_errno
* on errors to DICT_ERRBO_RETRY and set dict_errno to 0 on success
*********************************************************************/
static const char *dict_mysql_lookup(DICT *dict, const char *name)
{
MYSQL_RES *query_res;
MYSQL_ROW row;
DICT_MYSQL *dict_mysql;
PLMYSQL *pldb;
static VSTRING *result;
static VSTRING *query = 0;
int i,
numrows;
char *name_escaped = 0;
dict_mysql = (DICT_MYSQL *) dict;
pldb = dict_mysql->pldb;
/* initialization for query */
query = vstring_alloc(24);
vstring_strcpy(query, "");
if ((name_escaped = (char *) mymalloc((sizeof(char) * (strlen(name) * 2) +1))) == NULL) {
msg_fatal("dict_mysql_lookup: out of memory.");
}
/* prepare the query */
mysql_escape_string(name_escaped, name, (unsigned int) strlen(name));
vstring_sprintf(query, "select %s from %s where %s = '%s' %s", dict_mysql->name->select_field,
dict_mysql->name->table, dict_mysql->name->where_field, name_escaped,
dict_mysql->name->additional_conditions);
if (msg_verbose)
msg_info("dict_mysql_lookup using sql query: %s", vstring_str(query));
/* free mem associated with preparing the query */
myfree(name_escaped);
/* do the query - set dict_errno & cleanup if there's an error */
if ((query_res = plmysql_query(pldb,
vstring_str(query),
dict_mysql->name->dbname,
dict_mysql->name->username,
dict_mysql->name->password)) == 0) {
dict_errno = DICT_ERR_RETRY;
vstring_free(query);
return 0;
}
dict_errno = 0;
/* free the vstring query */
vstring_free(query);
numrows = mysql_num_rows(query_res);
if (msg_verbose)
msg_info("dict_mysql_lookup: retrieved %d rows", numrows);
if (numrows == 0) {
mysql_free_result(query_res);
return 0;
}
if (result == 0)
result = vstring_alloc(10);
vstring_strcpy(result, "");
for (i = 0; i < numrows; i++) {
row = mysql_fetch_row(query_res);
if (msg_verbose > 1)
msg_info("dict_mysql_lookup: retrieved row: %d: %s", i, row[0]);
if (i > 0)
vstring_strcat(result, ",");
vstring_strcat(result, row[0]);
}
mysql_free_result(query_res);
return vstring_str(result);
}
/*
* plmysql_query - process a MySQL query. Return MYSQL_RES* on success.
* On failure, log failure and try other db instances.
* on failure of all db instances, return 0;
* close unnecessary active connections
*/
static MYSQL_RES *plmysql_query(PLMYSQL *PLDB,
const char *query,
char *dbname,
char *username,
char *password)
{
int i;
HOST *host;
MYSQL_RES *res = 0;
for (i = 0; i < PLDB->len_hosts; i++) {
/* can't deal with typing or reading PLDB->db_hosts[i] over & over */
host = &(PLDB->db_hosts[i]);
if (msg_verbose > 1)
msg_info("dict_mysql: trying host %s stat %d, last res %p", host->hostname, host->stat, res);
/* answer already found */
if (res != 0 && host->stat == STATACTIVE) {
msg_info("dict_mysql: closing unnessary connection to %s", host->hostname);
mysql_close(&(host->db)); /* also frees memory, have to
* reallocate it */
host->db = *((MYSQL *) mymalloc(sizeof(MYSQL)));
plmysql_down_host(host);
}
/* try to connect for the first time if we don't have a result yet */
if (res == 0 && host->stat == STATUNTRIED) {
msg_info("dict_mysql: attempting to connect to host %s", host->hostname);
plmysql_connect_single(host, dbname, username, password);
}
/*
* try to reconnect if we don't have an answer and the host had a
* prob in the past and it's time for it to reconnect
*/
if (res == 0 && host->stat == STATFAIL && (plmysql_ready_reconn(*host))) {
msg_warn("dict_mysql: attempting to reconnect to host %s", host->hostname);
plmysql_connect_single(host, dbname, username, password);
}
/*
* if we don't have a result and the current host is marked active,
* try the query. If the query fails, mark the host STATFAIL
*/
if (res == 0 && host->stat == STATACTIVE) {
if (!(mysql_query(&(host->db), query))) {
if ((res = mysql_store_result(&(host->db))) == 0) {
msg_warn("%s", mysql_error(&(host->db)));
plmysql_down_host(host);
} else {
if (msg_verbose)
msg_info("dict_mysql: successful query from host %s", host->hostname);
}
} else {
msg_warn("%s", mysql_error(&(host->db)));
plmysql_down_host(host);
}
}
}
return res;
}
/*
* plmysql_connect_single -
* used to reconnect to a single database when one is down or none is
* connected yet. Log all errors and set the stat field of host accordingly
*/
static void plmysql_connect_single(HOST *host, char *dbname, char *username, char *password)
{
if (mysql_connect(&(host->db), host->hostname, username, password)) {
if (mysql_select_db(&(host->db), dbname) == 0) {
msg_info("dict_mysql: successful connection to host %s", host->hostname);
host->stat = STATACTIVE;
} else {
plmysql_down_host(host);
msg_warn("%s", mysql_error(&(host->db)));
}
} else {
plmysql_down_host(host);
msg_warn("%s", mysql_error(&(host->db)));
}
}
/*
* plmysql_down_host - mark a HOST down update ts if marked down
* for the first time so that we'll know when to retry the connection
*/
static void plmysql_down_host(HOST *host)
{
if (host->stat != STATFAIL) {
host->ts = time(&(host->ts));
host->stat = STATFAIL;
}
}
/*
* plmysql_ready_reconn -
* given a downed HOST, return whether or not it should retry connection
*/
static int plmysql_ready_reconn(HOST host)
{
time_t t;
long now;
now = (long) time(&t);
if (msg_verbose > 1) {
msg_info("dict_mysql: plmysql_ready_reconn(): now is %d", now);
msg_info("dict_mysql: plmysql_ready_reconn(): ts is %d", (long) host.ts);
msg_info("dict_mysql: plmysql_ready_reconn(): RETRY_CONN_INTV is %d", RETRY_CONN_INTV);
if ((now - ((long) host.ts)) >= RETRY_CONN_INTV) {
msg_info("dict_mysql: plymsql_ready_reconn(): returning TRUE");
return 1;
} else {
msg_info("dict_mysql: plymsql_ready_reconn(): returning FALSE");
return 0;
}
} else {
if ((now - ((long) host.ts)) >= RETRY_CONN_INTV)
return 1;
return 0;
}
}
/**********************************************************************
* public interface dict_mysql_open
* create association with database with appropriate values
* parse the map's config file
* allocate memory
**********************************************************************/
DICT *dict_mysql_open(const char *name, int unused_flags, int unused_dict_flags)
{
DICT_MYSQL *dict_mysql;
int connections;
dict_mysql = (DICT_MYSQL *) mymalloc(sizeof(DICT_MYSQL));
dict_mysql->dict.lookup = dict_mysql_lookup;
dict_mysql->dict.update = dict_mysql_update;
dict_mysql->dict.close = dict_mysql_close;
dict_mysql->dict.fd = -1; /* there's no file descriptor
* for locking */
dict_mysql->name = (MYSQL_NAME *) mymalloc(sizeof(MYSQL_NAME));
dict_mysql->name = mysqlname_parse(name);
dict_mysql->pldb = plmysql_init(dict_mysql->name->hostnames,
dict_mysql->name->len_hosts);
if (dict_mysql->pldb == NULL)
msg_fatal("couldn't intialize pldb!\n");
dict_register(name, (DICT *) dict_mysql);
return &dict_mysql->dict;
}
/* mysqlname_parse - parse mysql configuration file */
static MYSQL_NAME *mysqlname_parse(const char *mysqlcf_path)
{
int i;
char *nameval;
char *hosts;
MYSQL_NAME *name = (MYSQL_NAME *) mymalloc(sizeof(MYSQL_NAME));
ARGV *hosts_argv;
VSTRING *opt_dict_name;
/*
* setup a dict containing info in the mysql cf file. the dict has a
* name, and a path. The name must be distinct from the path, or the
* dict interface gets confused. The name must be distinct for two
* different paths, or the configuration info will cache across different
* mysql maps, which can be confusing.
*/
opt_dict_name = vstring_alloc(64);
vstring_sprintf(opt_dict_name, "mysql opt dict %s", mysqlcf_path);
dict_load_file(vstring_str(opt_dict_name), mysqlcf_path);
/* mysql username lookup */
if ((nameval = (char *) dict_lookup(vstring_str(opt_dict_name), "user")) == NULL)
name->username = mystrdup("");
else
name->username = mystrdup(nameval);
if (msg_verbose)
msg_info("mysqlname_parse(): set username to '%s'", name->username);
/* password lookup */
if ((nameval = (char *) dict_lookup(vstring_str(opt_dict_name), "password")) == NULL)
name->password = mystrdup("");
else
name->password = mystrdup(nameval);
if (msg_verbose)
msg_info("mysqlname_parse(): set password to '%s'", name->password);
/* database name lookup */
if ((nameval = (char *) dict_lookup(vstring_str(opt_dict_name), "dbname")) == NULL)
msg_fatal("%s: mysql options file does not include database name", mysqlcf_path);
else
name->dbname = mystrdup(nameval);
if (msg_verbose)
msg_info("mysqlname_parse(): set database name to '%s'", name->dbname);
/* table lookup */
if ((nameval = (char *) dict_lookup(vstring_str(opt_dict_name), "table")) == NULL)
msg_fatal("%s: mysql options file does not include table name", mysqlcf_path);
else
name->table = mystrdup(nameval);
if (msg_verbose)
msg_info("mysqlname_parse(): set table name to '%s'", name->table);
/* select field lookup */
if ((nameval = (char *) dict_lookup(vstring_str(opt_dict_name), "select_field")) == NULL)
msg_fatal("%s: mysql options file does not include select field", mysqlcf_path);
else
name->select_field = mystrdup(nameval);
if (msg_verbose)
msg_info("mysqlname_parse(): set select_field to '%s'", name->select_field);
/* where field lookup */
if ((nameval = (char *) dict_lookup(vstring_str(opt_dict_name), "where_field")) == NULL)
msg_fatal("%s: mysql options file does not include where field", mysqlcf_path);
else
name->where_field = mystrdup(nameval);
if (msg_verbose)
msg_info("mysqlname_parse(): set where_field to '%s'", name->where_field);
/* additional conditions */
if ((nameval = (char *) dict_lookup(vstring_str(opt_dict_name), "additional_conditions")) == NULL)
name->additional_conditions = mystrdup("");
else
name->additional_conditions = mystrdup(nameval);
if (msg_verbose)
msg_info("mysqlname_parse(): set additional_conditions to '%s'", name->additional_conditions);
/* mysql server hosts */
if ((nameval = (char *) dict_lookup(vstring_str(opt_dict_name), "hosts")) == NULL)
hosts = mystrdup("");
else
hosts = mystrdup(nameval);
/* coo argv interface */
hosts_argv = argv_split(hosts, " ");
argv_terminate(hosts_argv);
if (hosts_argv->argc == 0) { /* no hosts specified,
* default to 'localhost' */
msg_info("mysqlname_parse(): no hostnames specified, defaulting to 'localhost'");
name->len_hosts = 1;
name->hostnames = (char **) mymalloc(sizeof(char *));
name->hostnames[0] = mystrdup("localhost");
} else {
name->len_hosts = hosts_argv->argc;
name->hostnames = (char **) mymalloc((sizeof(char *)) * name->len_hosts);
i = 0;
for (i = 0; hosts_argv->argv[i] != NULL; i++) {
name->hostnames[i] = mystrdup(hosts_argv->argv[i]);
if (msg_verbose)
msg_info("mysqlname_parse(): adding host '%s' to list of mysql server hosts",
name->hostnames[i]);
}
}
myfree(hosts);
vstring_free(opt_dict_name);
argv_free(hosts_argv);
return name;
}
/*
* plmysql_init - initalize a MYSQL database.
* Return NULL on failure, or a PLMYSQL * on success.
*/
static PLMYSQL *plmysql_init(char *hostnames[],
int len_hosts)
{
PLMYSQL *PLDB;
MYSQL *dbs;
int i;
HOST host;
if ((PLDB = (PLMYSQL *) mymalloc(sizeof(PLMYSQL))) == NULL) {
msg_fatal("mymalloc of pldb failed");
}
PLDB->len_hosts = len_hosts;
if ((PLDB->db_hosts = (HOST *) mymalloc(sizeof(HOST) * len_hosts)) == NULL)
return NULL;
for (i = 0; i < len_hosts; i++) {
PLDB->db_hosts[i] = host_init(hostnames[i]);
}
return PLDB;
}
/* host_init - initialize HOST structure */
static HOST host_init(char *hostname)
{
int stat;
MYSQL db;
time_t ts;
HOST host;
host.stat = STATUNTRIED;
host.hostname = hostname;
host.db = db;
host.ts = ts;
return host;
}
/**********************************************************************
* public interface dict_mysql_close
* unregister, disassociate from database, freeing appropriate memory
**********************************************************************/
static void dict_mysql_close(DICT *dict)
{
int i;
DICT_MYSQL *dict_mysql = (DICT_MYSQL *) dict;
plmysql_dealloc(dict_mysql->pldb);
myfree(dict_mysql->name->username);
myfree(dict_mysql->name->password);
myfree(dict_mysql->name->dbname);
myfree(dict_mysql->name->table);
myfree(dict_mysql->name->select_field);
myfree(dict_mysql->name->where_field);
myfree(dict_mysql->name->additional_conditions);
for (i = 0; i < dict_mysql->name->len_hosts; i++) {
myfree(dict_mysql->name->hostnames[i]);
}
myfree((char *) dict_mysql->name);
}
/* plmysql_dealloc - free memory associated with PLMYSQL close databases */
static void plmysql_dealloc(PLMYSQL *PLDB)
{
int i;
for (i = 0; i < PLDB->len_hosts; i++) {
mysql_close(&(PLDB->db_hosts[i].db));
myfree(PLDB->db_hosts[i].hostname);
}
myfree((char *) PLDB->db_hosts);
myfree((char *) (PLDB));
}
/**********************************************************************
* public interface dict_mysql_update - add or update table entry
*
*********************************************************************/
static void dict_mysql_update(DICT *dict, const char *unused_name, const char *unused_value)
{
DICT_MYSQL *dict_mysql = (DICT_MYSQL *) dict;
msg_fatal("dict_mysql_update: attempt to update mysql database");
}
#endif