| Current File : //root/postfix-3.2.0/src/global/dynamicmaps.c |
/*++
/* NAME
/* dynamicmaps 3
/* SUMMARY
/* load dictionaries dynamically
/* SYNOPSIS
/* #include <dynamicmaps.h>
/*
/* void dymap_init(const char *conf_path, const char *plugin_dir)
/* DESCRIPTION
/* This module reads the dynamicmaps.cf file and performs
/* run-time loading of Postfix dictionaries. Each dynamicmaps.cf
/* entry specifies the name of a dictionary type, the pathname
/* of a shared-library object, the name of a "dict_open"
/* function for access to individual dictionary entries, and
/* optionally the name of a "mkmap_open" function for bulk-mode
/* dictionary creation. Plugins may be specified with a relative
/* pathname.
/*
/* A dictionary may be installed without editing the file
/* dynamicmaps.cf, by placing a configuration file under the
/* directory dynamicmaps.cf.d, with the same format as
/* dynamicmaps.cf.
/*
/* dymap_init() reads the specified configuration file which
/* is in dynamicmaps.cf format, and hooks itself into the
/* dict_open(), dict_mapnames(), and mkmap_open() functions.
/*
/* dymap_init() may be called multiple times during a process
/* lifetime, but it will not "unload" dictionaries that have
/* already been linked into the process address space, nor
/* will it hide their dictionaries types from later "open"
/* requests.
/*
/* Arguments:
/* .IP conf_path
/* Pathname for the dynamicmaps configuration file.
/* .IP plugin_dir
/* Default directory for plugins with a relative pathname.
/* SEE ALSO
/* load_lib(3) low-level run-time linker adapter
/* DIAGNOSTICS
/* Fatal errors: memory allocation problem, dictionary or
/* dictionary function not available. Panic: invalid use.
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* LaMont Jones
/* Hewlett-Packard Company
/* 3404 Harmony Road
/* Fort Collins, CO 80528, USA
/*
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/*
* System library.
*/
#include <sys_defs.h>
#include <sys/stat.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
/*
* Utility library.
*/
#include <msg.h>
#include <mymalloc.h>
#include <htable.h>
#include <argv.h>
#include <dict.h>
#include <load_lib.h>
#include <vstring.h>
#include <vstream.h>
#include <vstring_vstream.h>
#include <stringops.h>
#include <split_at.h>
#include <scan_dir.h>
/*
* Global library.
*/
#include <mkmap.h>
#include <dynamicmaps.h>
#ifdef USE_DYNAMIC_MAPS
/*
* Contents of one dynamicmaps.cf entry.
*/
typedef struct {
char *soname; /* shared-object file name */
char *dict_name; /* dict_xx_open() function name */
char *mkmap_name; /* mkmap_xx_open() function name */
} DYMAP_INFO;
static HTABLE *dymap_info;
static int dymap_hooks_done = 0;
static DICT_OPEN_EXTEND_FN saved_dict_open_hook = 0;
static MKMAP_OPEN_EXTEND_FN saved_mkmap_open_hook = 0;
static DICT_MAPNAMES_EXTEND_FN saved_dict_mapnames_hook = 0;
#define STREQ(x, y) (strcmp((x), (y)) == 0)
/* dymap_dict_lookup - look up "dict_foo_open" function */
static DICT_OPEN_FN dymap_dict_lookup(const char *dict_type)
{
struct stat st;
LIB_FN fn[2];
DICT_OPEN_FN dict_open_fn;
DYMAP_INFO *dp;
/*
* Respect the hook nesting order.
*/
if (saved_dict_open_hook != 0
&& (dict_open_fn = saved_dict_open_hook(dict_type)) != 0)
return (dict_open_fn);
/*
* Allow for graceful degradation when a database is unavailable. This
* allows Postfix daemon processes to continue handling email with
* reduced functionality.
*/
if ((dp = (DYMAP_INFO *) htable_find(dymap_info, dict_type)) == 0)
return (0);
if (stat(dp->soname, &st) < 0) {
msg_warn("unsupported dictionary type: %s (%s: %m)",
dict_type, dp->soname);
return (0);
}
if (st.st_uid != 0 || (st.st_mode & (S_IWGRP | S_IWOTH)) != 0) {
msg_warn("unsupported dictionary type: %s "
"(%s: file is owned or writable by non-root users)",
dict_type, dp->soname);
return (0);
}
fn[0].name = dp->dict_name;
fn[1].name = 0;
load_library_symbols(dp->soname, fn, (LIB_DP *) 0);
return ((DICT_OPEN_FN) fn[0].fptr);
}
/* dymap_mkmap_lookup - look up "mkmap_foo_open" function */
static MKMAP_OPEN_FN dymap_mkmap_lookup(const char *dict_type)
{
struct stat st;
LIB_FN fn[2];
MKMAP_OPEN_FN mkmap_open_fn;
DYMAP_INFO *dp;
/*
* Respect the hook nesting order.
*/
if (saved_mkmap_open_hook != 0
&& (mkmap_open_fn = saved_mkmap_open_hook(dict_type)) != 0)
return (mkmap_open_fn);
/*
* All errors are fatal. If the postmap(1) or postalias(1) command can't
* create the requested database, then graceful degradation is not
* useful.
*/
if ((dp = (DYMAP_INFO *) htable_find(dymap_info, dict_type)) == 0)
msg_fatal("unsupported dictionary type: %s. "
"Is the postfix-%s package installed?",
dict_type, dict_type);
if (!dp->mkmap_name)
msg_fatal("unsupported dictionary type: %s does not support "
"bulk-mode creation.", dict_type);
if (stat(dp->soname, &st) < 0)
msg_fatal("unsupported dictionary type: %s (%s: %m). "
"Is the postfix-%s package installed?",
dict_type, dp->soname, dict_type);
if (st.st_uid != 0 || (st.st_mode & (S_IWGRP | S_IWOTH)) != 0)
msg_fatal("unsupported dictionary type: %s "
"(%s: file is owned or writable by non-root users)",
dict_type, dp->soname);
fn[0].name = dp->mkmap_name;
fn[1].name = 0;
load_library_symbols(dp->soname, fn, (LIB_DP *) 0);
return ((MKMAP_OPEN_FN) fn[0].fptr);
}
/* dymap_list - enumerate dynamically-linked database type names */
static void dymap_list(ARGV *map_names)
{
HTABLE_INFO **ht_list, **ht;
/*
* Respect the hook nesting order.
*/
if (saved_dict_mapnames_hook != 0)
saved_dict_mapnames_hook(map_names);
for (ht_list = ht = htable_list(dymap_info); *ht != 0; ht++)
argv_add(map_names, ht[0]->key, ARGV_END);
myfree((void *) ht_list);
}
/* dymap_entry_alloc - allocate dynamicmaps.cf entry */
static DYMAP_INFO *dymap_entry_alloc(char **argv)
{
DYMAP_INFO *dp;
dp = (DYMAP_INFO *) mymalloc(sizeof(*dp));
dp->soname = mystrdup(argv[0]);
dp->dict_name = mystrdup(argv[1]);
dp->mkmap_name = argv[2] ? mystrdup(argv[2]) : 0;
return (dp);
}
/* dymap_entry_free - htable(3) call-back to destroy dynamicmaps.cf entry */
static void dymap_entry_free(void *ptr)
{
DYMAP_INFO *dp = (DYMAP_INFO *) ptr;
myfree(dp->soname);
myfree(dp->dict_name);
if (dp->mkmap_name)
myfree(dp->mkmap_name);
myfree((void *) dp);
}
/* dymap_read_conf - read dynamicmaps.cf-like file */
static void dymap_read_conf(const char *path, const char *path_base)
{
VSTREAM *fp;
VSTRING *buf;
char *cp;
ARGV *argv;
int linenum = 0;
struct stat st;
/*
* Silently ignore a missing dynamicmaps.cf file, but be explicit about
* problems when the file does exist.
*/
if ((fp = vstream_fopen(path, O_RDONLY, 0)) != 0) {
if (fstat(vstream_fileno(fp), &st) < 0)
msg_fatal("%s: fstat failed; %m", path);
if (st.st_uid != 0 || (st.st_mode & (S_IWGRP | S_IWOTH)) != 0) {
msg_warn("%s: file is owned or writable by non-root users"
" -- skipping this file", path);
} else {
buf = vstring_alloc(100);
while (vstring_get_nonl(buf, fp) != VSTREAM_EOF) {
cp = vstring_str(buf);
linenum++;
if (*cp == '#' || *cp == '\0')
continue;
argv = argv_split(cp, " \t");
if (argv->argc != 3 && argv->argc != 4)
msg_fatal("%s, line %d: Expected \"dict-type .so-name dict"
"-function [mkmap-function]\"", path, linenum);
if (!ISALNUM(argv->argv[0][0]))
msg_fatal("%s, line %d: unsupported syntax \"%s\"",
path, linenum, argv->argv[0]);
if (argv->argv[1][0] != '/') {
cp = concatenate(path_base, "/", argv->argv[1], (char *) 0);
argv_replace_one(argv, 1, cp);
myfree(cp);
}
if (htable_locate(dymap_info, argv->argv[0]) != 0)
msg_warn("%s: ignoring duplicate entry for \"%s\"",
path, argv->argv[0]);
else
htable_enter(dymap_info, argv->argv[0],
(void *) dymap_entry_alloc(argv->argv + 1));
argv_free(argv);
}
vstring_free(buf);
/*
* Once-only: hook into the dict_open(3) and mkmap_open(3)
* infrastructure,
*/
if (dymap_hooks_done == 0) {
dymap_hooks_done = 1;
saved_dict_open_hook = dict_open_extend(dymap_dict_lookup);
saved_mkmap_open_hook = mkmap_open_extend(dymap_mkmap_lookup);
saved_dict_mapnames_hook = dict_mapnames_extend(dymap_list);
}
}
vstream_fclose(fp);
} else if (errno != ENOENT) {
msg_fatal("%s: file open failed: %m", path);
}
}
/* dymap_init - initialize dictionary type to soname etc. mapping */
void dymap_init(const char *conf_path, const char *plugin_dir)
{
static const char myname[] = "dymap_init";
SCAN_DIR *dir;
char *conf_path_d;
const char *conf_name;
VSTRING *sub_conf_path;
/*
* Reload dynamicsmaps.cf, but don't reload already-loaded plugins.
*/
if (dymap_info != 0)
htable_free(dymap_info, dymap_entry_free);
dymap_info = htable_create(3);
/*
* Read dynamicmaps.cf.
*/
dymap_read_conf(conf_path, plugin_dir);
/*
* Read dynamicmaps.cf.d/filename entries.
*/
conf_path_d = concatenate(conf_path, ".d", (char *) 0);
if (access(conf_path_d, R_OK | X_OK) == 0
&& (dir = scan_dir_open(conf_path_d)) != 0) {
sub_conf_path = vstring_alloc(100);
while ((conf_name = scan_dir_next(dir)) != 0) {
vstring_sprintf(sub_conf_path, "%s/%s", conf_path_d, conf_name);
dymap_read_conf(vstring_str(sub_conf_path), plugin_dir);
}
if (errno != 0)
/* Don't crash all programs - degrade gracefully. */
msg_warn("%s: directory read error: %m", conf_path_d);
scan_dir_close(dir);
vstring_free(sub_conf_path);
} else if (errno != ENOENT) {
/* Don't crash all programs - degrade gracefully. */
msg_warn("%s: directory open failed: %m", conf_path_d);
}
myfree(conf_path_d);
/*
* Future proofing, in case someone "improves" the code. We can't hook
* into other functions without initializing our private lookup table.
*/
if (dymap_hooks_done != 0 && dymap_info == 0)
msg_panic("%s: post-condition botch", myname);
}
#endif