devfsd.c

devfsd 驱动对linux的补丁支持

	free_config ();
	*event_mask = 0;
	return;
    }
    if (num_args < 2)
    {
	SYSLOG (LOG_ERR, "bad config line: \"%s\"\n", line);
	SYSLOG (LOG_ERR, "exiting\n");
	exit (1);
    }
    if ( (strcasecmp (when, "INCLUDE") == 0) ||
	 (strcasecmp (when, "OPTIONAL_INCLUDE") == 0) )
    {
	st_expr_expand (name, STRING_LENGTH, name, get_variable, NULL,
			NULL);
	read_config (name, (toupper (when[0]) == 'I') ? FALSE : TRUE,
		     event_mask);
	return;
    }
    if (strcasecmp (when, "RESTORE") == 0)
    {
	do_restore ( name, strlen (name) );
	return;
    }
    if (num_args < 3)
    {
	SYSLOG (LOG_ERR, "bad config line: \"%s\"\n", line);
	SYSLOG (LOG_ERR, "exiting\n");
	exit (1);
    }
    if ( ( new = malloc (sizeof *new) ) == NULL )
    {
	SYSLOG (LOG_ERR, "error allocating\n");
	SYSLOG (LOG_ERR, "exiting\n");
	exit (1);
    }
    memset (new, 0, sizeof *new);
    for (count = 0; event_types[count].config_name != NULL; ++count)
    {
	if (strcasecmp (when, event_types[count].config_name) != 0) continue;
	new->action.when = event_types[count].type;
	break;
    }
    if (event_types[count].config_name == NULL)
    {
	SYSLOG (LOG_ERR, "bad WHEN in config line: \"%s\"\n", line);
	SYSLOG (LOG_ERR, "exiting\n");
	exit (1);
    }
    if (strcasecmp (what, "PERMISSIONS") == 0)
    {
	char *ptr;

	new->action.what = AC_PERMISSIONS;
	/*  Get user and group  */
	if ( ( ptr = strchr (p[0], '.') ) == NULL )
	{
	    SYSLOG (LOG_ERR, "missing '.' character in: \"%s\"\n", p[0]);
	    SYSLOG (LOG_ERR, "exiting\n");
	    exit (1);
	}
	*ptr++ = '\0';
	new->u.permissions.uid = get_uid (p[0]);
	new->u.permissions.gid = get_gid (ptr);
	/*  Get mode  */
	new->u.permissions.mode = get_mode (p[1]);
    }
    else if (strcasecmp (what, "MODLOAD") == 0) new->action.what = AC_MODLOAD;
    else if (strcasecmp (what, "EXECUTE") == 0)
    {
	new->action.what = AC_EXECUTE;
	num_args -= 3;
	if (strstr (p[0], "modprobe") != NULL)
	{   /*  Bitch and moan  */
	    SYSLOG (LOG_NOTICE,
		    "Use MODLOAD action instead of EXECUTE modprobe!\n");
	    exit (1);
	}
	for (count = 0; count < num_args; ++count)
	{
	    if ( ( new->u.execute.argv[count] = strdup (p[count]) ) == NULL )
	    {
		SYSLOG (LOG_ERR, "error allocating\n");
		SYSLOG (LOG_ERR, "exiting\n");
		exit (1);
	    }
	}
	new->u.execute.argv[num_args] = NULL;
    }
    else if ( (strcasecmp (what, "MFUNCTION") == 0) ||
	      (strcasecmp (what, "CFUNCTION") == 0) )
    {
	new->action.what = (strcasecmp (what, "MFUNCTION") == 0) ?
	    AC_MFUNCTION : AC_CFUNCTION;
	num_args -= 3;
	if (num_args < 2)
	{
	    SYSLOG (LOG_ERR, "missing path and function in \"%s\"\n",line);
	    exit (1);
	}
	if ( ( new->u.function.so = get_shared_object (p[0]) ) == NULL )
	{
	    SYSLOG (LOG_ERR, "error loading: \"%s\"\t%s\n", p[0], dlerror () );
	    exit (1);
	}
	new->u.function.func.m =
	    dlsym_nofail (p[0], new->u.function.so->handle, p[1]);
	--num_args;
	for (count = 0; count < num_args; ++count)
	{
	    if ( ( new->u.function.argv[count] = strdup (p[count + 1]) )
		 == NULL )
	    {
		SYSLOG (LOG_ERR, "error allocating\n");
		SYSLOG (LOG_ERR, "exiting\n");
		exit (1);
	    }
	}
	new->u.function.argv[num_args] = NULL;
    }
    else if (strcasecmp (what, "COPY") == 0)
    {
	new->action.what = AC_COPY;
	num_args -= 3;
	if (num_args != 2)
	{
	    SYSLOG (LOG_ERR, "missing path and function in \"%s\"\n", line);
	    exit (1);
	}
	if ( ( new->u.copy.source = strdup (p[0]) ) == NULL )
	{
	    SYSLOG (LOG_ERR, "error allocating source string\n");
	    SYSLOG (LOG_ERR, "exiting\n");
	    exit (1);
	}
	if ( ( new->u.copy.destination = strdup (p[1]) ) == NULL )
	{
	    SYSLOG (LOG_ERR, "error allocating destination string\n");
	    SYSLOG (LOG_ERR, "exiting\n");
	    exit (1);
	}
    }
    else if (strcasecmp (what, "IGNORE") == 0) new->action.what = AC_IGNORE;
    else if (strcasecmp (what, "MKOLDCOMPAT") == 0)
	new->action.what = AC_MKOLDCOMPAT;
    else if (strcasecmp (what, "MKNEWCOMPAT") == 0)
	new->action.what = AC_MKNEWCOMPAT;
    else if (strcasecmp (what, "RMOLDCOMPAT") == 0)
	new->action.what = AC_RMOLDCOMPAT;
    else if (strcasecmp (what, "RMNEWCOMPAT") == 0)
	new->action.what = AC_RMNEWCOMPAT;
    else
    {
	SYSLOG (LOG_ERR, "bad WHAT in config line: \"%s\"\n", line);
	SYSLOG (LOG_ERR, "exiting\n");
	exit (1);
    }
    if ( ( err = regcomp (&new->preg, name, REG_EXTENDED) ) != 0 )
    {
	regerror (err, &new->preg, tmp, STRING_LENGTH);
	SYSLOG (LOG_ERR, "error compiling regexp: \"%s\"\t%s\n", name,tmp);
	SYSLOG (LOG_ERR, "exiting\n");
	exit (1);
    }
    *event_mask |= 1 << new->action.when;
    new->next = NULL;
    if (first_config == NULL) first_config = new;
    else last_config->next = new;
    last_config = new;
}   /*  End Function process_config_line   */

static void *dlsym_nofail (const char *file, void *handle, char *symbol)
{
    void *result = dlsym (handle, symbol);
    if (result == NULL)
    {
	SYSLOG (LOG_ERR, "symbol: \"%s\" not found in %s\n", symbol, file);
	exit (1);
    }
    return (result);
}   /*  End Function dlsym_nofail  */

static void load_libnsl (void)
{
#ifdef LIBNSL  /*  It comes from a shared object  */
    void *libnsl_handle;

    libnsl_handle = dlopen (LIBNSL, RTLD_LAZY);
    if (libnsl_handle == NULL)
    {
        SYSLOG ( LOG_ERR, "read map: unable to open %s: %s",
		 LIBNSL, dlerror() );
	exit (1);
    }
    my_yp_all = dlsym_nofail (LIBNSL, libnsl_handle, "yp_all");
    my_yp_get_default_domain =
        dlsym_nofail (LIBNSL, libnsl_handle, "yp_get_default_domain");
#else  /*  It's built-in the C library  */
    my_yp_all = yp_all;
    my_yp_get_default_domain = yp_get_default_domain;
#endif
}   /*  End Function load_libnsl  */

static int process_yp_line (int instatus, char *inkey, int inkeylen,
			    char *inval, int invallen, char *indata)
{
    if (instatus != YP_TRUE) return (instatus);
    if (invallen > 0) process_config_line (inval, (unsigned long *) indata);
    return (0);
}   /*  End Function process_yp_line  */

static flag do_servicing (int fd, unsigned long event_mask)
/*  [SUMMARY] Service devfs changes until a signal is received.
    <fd> The open control file.
    <event_mask> The event mask.
    [RETURNS] TRUE if SIGHUP was caught, else FALSE.
*/
{
    ssize_t bytes;
    struct devfsd_notify_struct info;
    unsigned long tmp_event_mask;

    /*  Tell devfs what events we care about  */
    tmp_event_mask = event_mask;
    /*  May need to trap inode creates to watch for syslogd(8) starting  */
    if (!syslog_is_open && !no_syslog)
    {
	tmp_event_mask |= 1 << DEVFSD_NOTIFY_CREATE;
    }
    if (ioctl (fd, DEVFSDIOC_SET_EVENT_MASK, tmp_event_mask) != 0)
    {
	SYSLOG (LOG_ERR, "error setting event mask\t%s\n", ERRSTRING);
	exit (1);
    }
    while (!caught_signal)
    {
	errno = 0;
	bytes = read (fd, (char *) &info, sizeof info);
	if (caught_signal) break;      /*  Must test for this first     */
	if (errno == EINTR) continue;  /*  Yes, the order is important  */
	if (bytes < 1) break;
	/*  Special trap for "/dev/log" creation  */
	if (!syslog_is_open && !no_syslog &&
	    (info.type == DEVFSD_NOTIFY_CREATE) &&
	    (strcmp (info.devname, "log") == 0) )
	{
	    /*  Open syslog, now that "/dev/log" exists  */
	    do_open_syslog ();
	    if (ioctl (fd, DEVFSDIOC_SET_EVENT_MASK, event_mask) != 0)
	    {
		SYSLOG (LOG_ERR, "error setting event mask\t%s\n", ERRSTRING);
		exit (1);
	    }
	}
	service_name (&info);
    }
    if (caught_signal)
    {
	flag c_sighup = caught_sighup;

	caught_signal = FALSE;
	caught_sighup = FALSE;
	return (c_sighup);
    }
    SYSLOG (LOG_ERR, "Error reading control file\t%s\n", ERRSTRING);
    exit (1);
}   /*  End Function do_servicing  */

static void service_name (const struct devfsd_notify_struct *info)
/*  [SUMMARY] Service a single devfs change.
    <info> The devfs change.
    [RETURNS] Nothing.
*/
{
    unsigned int n;
    regmatch_t mbuf[MAX_SUBEXPR];
    struct config_entry_struct *entry;

    if (info->overrun_count > 0)
	SYSLOG (LOG_ERR, "%u events have been lost!\n", info->overrun_count);
    if (trace_level > 2) fprintf (stderr, "Looking for \"%s\" (%d)\n",
				  info->devname, info->type);
    /*  Discard lookups on "/dev/log" and "/dev/initctl"  */
    if (info->type == DEVFSD_NOTIFY_LOOKUP)
    {
	if ( (strcmp (info->devname, "log") == 0) ||
	     (strcmp (info->devname, "initctl") == 0) ) return;
    }
    for (entry = first_config; entry != NULL; entry = entry->next)
    {
	if (trace_level > 3) fprintf (stderr, "\t\tProcess \"%s\" (%d)\n",
				      info->devname, entry->action.when);
	/*  First check if action matches the type, then check if name matches
	 */
	if (info->type != entry->action.when) continue;
	if (regexec (&entry->preg, info->devname, MAX_SUBEXPR, mbuf, 0) != 0)
	    continue;
	for (n = 0; (n < MAX_SUBEXPR) && (mbuf[n].rm_so != -1); ++n);
	switch (entry->action.what)
	{
	  case AC_PERMISSIONS:
	    action_permissions (info, entry);
	    break;
	  case AC_MODLOAD:
	    action_modload (info, entry);
	    break;
	  case AC_EXECUTE:
	    action_execute (info, entry, mbuf, n);
	    break;
	  case AC_MFUNCTION:
	  case AC_CFUNCTION:
	    action_call_function (info, entry, mbuf, n);
	    break;
	  case AC_COPY:
	    action_copy (info, entry, mbuf, n);
	    break;
	  case AC_IGNORE:
	    return;
	    /*break;*/
	  case AC_MKOLDCOMPAT:
	  case AC_MKNEWCOMPAT:
	  case AC_RMOLDCOMPAT:
	  case AC_RMNEWCOMPAT:
	    action_compat (info, entry->action.what);
	    break;
	  default:
	    SYSLOG (LOG_ERR, "Unknown action type: %u\n", entry->action.what);
	    exit (1);
	    /*break;*/
	}
    }
}   /*  End Function service_name  */

static void action_permissions (const struct devfsd_notify_struct *info,
				const struct config_entry_struct *entry)
/*  [SUMMARY] Update permissions for a device entry.
    <info> The devfs change.
    <entry> The config file entry.
    [RETURNS] Nothing.
*/
{
    mode_t new_mode;
    struct stat statbuf;

    if (stat (info->devname, &statbuf) != 0)
    {
	SYSLOG (LOG_ERR, "error stat(2)ing: \"%s\"\t%s\n",
		info->devname, ERRSTRING);
	return;
    }
    new_mode = (statbuf.st_mode & S_IFMT) |
	(entry->u.permissions.mode & ~S_IFMT);
    if (trace_level > 2)
	fprintf (stderr,
		 "\tupdate permissions for \"%s\" from %05o to %05o, user.group from %d.%d to %d.%d\n",
		 info->devname, info->mode, new_mode, info->uid, info->gid,
		 entry->u.permissions.uid, entry->u.permissions.gid);
    if (new_mode != statbuf.st_mode)
    {
	if (chmod (info->devname, new_mode) != 0)
	{
	    SYSLOG (LOG_ERR, "error changing mode for: \"%s\"\t%s\n",
		    info->devname, ERRSTRING);
	    return;
	}
	if (trace_level > 2) fprintf (stderr,"Set permission %05o on \"%s\"\n",
				      new_mode, info->devname);
    }
    if ( (entry->u.permissions.uid != statbuf.st_uid) ||
	 (entry->u.permissions.gid != statbuf.st_gid) )
    {
	if (chown (info->devname, entry->u.permissions.uid,
		   entry->u.permissions.gid) != 0)
	{
	    SYSLOG (LOG_ERR, "error changing owner for: \"%s\"\t%s\n",
		    info->devname, ERRSTRING);
	    return;
	}
	if (trace_level > 2)
	    fprintf (stderr, "Set user.group %d.%d on \"%s\"\n",
		     entry->u.permissions.uid, entry->u.permissions.gid,
		     info->devname);
    }
}   /*  End Function action_permissions  */

static void action_modload (const struct devfsd_notify_struct *info,
			    const struct config_entry_struct *entry)
/*  [SUMMARY] Load a module.
    <info> The devfs change.
    <entry> The config file entry.
    [RETURNS] Nothing.
*/
{
    char *argv[6];
    char device[STRING_LENGTH];
    char *env[4] = {"HOME=/", "TERM=linux",  /*  Safe mode environment  */
		    "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL};
    static int (*modprobe) (int argc, char **argv) = NULL;
    static flag first_time = TRUE;

    if (first_time)
    {
	void *lib;

	first_time = FALSE;
	if ( ( lib = dlopen ("/lib/modutils.so", RTLD_NOW) ) != NULL )
	{
	    if ( ( modprobe = dlsym (lib, "modprobe") ) == NULL )
		SYSLOG(LOG_ERR, "/lib/modutils.so doesn't contain modprobe()");
	}
	else if (trace_level > 1)
	    fprintf (stderr, "/lib/modutils.so load failure: %s\n",dlerror() );
    }