devfsd.c

devfsd 驱动对linux的补丁支持

    argv[0] = "/sbin/modprobe";
    argv[1] = "-k";
    argv[2] = "-C";
    argv[3] = "/etc/modules.devfs";
    argv[4] = device;
    argv[5] = NULL;
    snprintf (device, sizeof (device), "/dev/%s", info->devname);
    if (trace_level > 1)
	fprintf (stderr, "%s modprobe with name: \"%s\"\n",
		 modprobe ? "Calling" : "Executing", device);
    if (modprobe != NULL)
    {
	char **oldenv = environ;

	environ = env;
	(*modprobe) (5, argv);
	environ = oldenv;
	return;
    }
    switch ( fork () )
    {
      case 0:
	/*  Child  */
	break;
      case -1:
	/*  Error  */
	SYSLOG (LOG_ERR, "error forking\t%s\n", ERRSTRING);
	exit (2);
	/*break;*/
      default:
	/*  Parent  */
	wait (NULL);
	return;
	/*break;*/
    }
    environ = env;
    execvp (argv[0], argv);
    SYSLOG (LOG_ERR, "error execing: \"%s\"\t%s\n", argv[0], ERRSTRING);
    _exit (1);
}   /*  End Function action_modload  */

static void action_execute (const struct devfsd_notify_struct *info,
			    const struct config_entry_struct *entry,
			    const regmatch_t *regexpr, unsigned int numexpr)
/*  [SUMMARY] Execute a programme.
    <info> The devfs change.
    <entry> The config file entry.
    <regexpr> The number of subexpression (start, end) offsets within the
    device name.
    <numexpr> The number of elements within <<regexpr>>.
    [RETURNS] Nothing.
*/
{
    unsigned int count;
    struct get_variable_info gv_info;
    char *argv[MAX_ARGS + 1];
    char largv[MAX_ARGS + 1][STRING_LENGTH];

    gv_info.info = info;
    gv_info.devname = info->devname;
    snprintf (gv_info.devpath, sizeof (gv_info.devpath), "%s/%s",
	      mount_point, info->devname);
    if (trace_level > 1) fprintf (stderr, "Calling %s for \"%s\" | \"%s\":",
				  entry->u.execute.argv[0], info->devname,
				  gv_info.devpath);
    for (count = 0; entry->u.execute.argv[count] != NULL; ++count)
    {
	expand_expression (largv[count], STRING_LENGTH,
			   entry->u.execute.argv[count],
			   get_variable, &gv_info,
			   gv_info.devname, regexpr, numexpr, NULL);
	argv[count] = largv[count];
	if (trace_level > 1) fprintf (stderr, " '%s'", argv[count]);
    }
    if (trace_level > 1) fprintf (stderr, ". i.e. %d arg%s\n",
				  count - 1, (count == 2) ? "" : "s");
    argv[count] = NULL;
    switch ( fork () )
    {
      case 0:
	/*  Child  */
	break;
      case -1:
	/*  Error  */
	SYSLOG (LOG_ERR, "error forking for programme: %s\t%s\n",
		argv[0], ERRSTRING);
	return;
	/*break;*/
      default:
	/*  Parent  */
	wait (NULL);
	return;
	/*break;*/
    }
    execvp (argv[0], argv);
    SYSLOG (LOG_ERR, "error execing: \"%s\"\t%s\n", argv[0], ERRSTRING);
    _exit (1);
}   /*  End Function action_execute  */

static void action_call_function (const struct devfsd_notify_struct *info,
				  const struct config_entry_struct *entry,
				  const regmatch_t *regexpr,
				  unsigned int numexpr)
/*  [SUMMARY] Call a function.
    <info> The devfs change.
    <entry> The config file entry.
    <regexpr> The number of subexpression (start, end) offsets within the
    device name.
    <numexpr> The number of elements within <<regexpr>>.
    [RETURNS] Nothing.
*/
{
    unsigned int count;
    struct get_variable_info gv_info;
    char *argv[MAX_ARGS + 1];
    char largv[MAX_ARGS + 1][STRING_LENGTH];

    gv_info.info = info;
    gv_info.devname = info->devname;
    snprintf (gv_info.devpath, sizeof (gv_info.devpath), "%s/%s",
	      mount_point, info->devname);
    if (trace_level > 1)
	fprintf (stderr, "Calling %s in %s for \"%s\" | \"%s\":",
		 entry->u.function.argv[0], entry->u.function.so->name,
		 info->devname, gv_info.devpath);
    argv[0] = (char *) entry->u.function.so->name;
    for (count = 1; entry->u.function.argv[count] != NULL; ++count)
    {
	if (strcmp (entry->u.function.argv[count], "EVENT") == 0)
	    argv[count] = (char *) info;
	else
	{
	    expand_expression (largv[count], STRING_LENGTH,
			       entry->u.function.argv[count], get_variable,
			       &gv_info, gv_info.devname, regexpr, numexpr,
			       NULL);
	    argv[count] = largv[count];
	    if (trace_level > 1) fprintf (stderr, " '%s'", argv[count]);
	}
    }
    if (trace_level > 1) fprintf (stderr, ". i.e. %d arg%s\n",
				  count - 1, (count == 2) ? "" : "s");
    argv[count] = NULL;
    if (entry->action.what == AC_MFUNCTION)
    {
	if ( (*entry->u.function.func.m) (count, argv) == 0 )
	    return;
    }
    else
    {
	if ( (*entry->u.function.func.c) (argv[1], argv[2], argv[3], argv[4],
					  argv[5]) == 0 ) return;
    }
    SYSLOG (LOG_ERR, "error calling: \"%s\" in \"%s\"\n",
	    entry->u.function.argv[0], argv[0]);
}   /*  End Function action_call_function  */

static void action_copy (const struct devfsd_notify_struct *info,
			 const struct config_entry_struct *entry,
                         const regmatch_t *regexpr, unsigned int numexpr)
/*  [SUMMARY] Copy permissions.
    <info> The devfs change.
    <entry> The config file entry.
    <regexpr> This list of subexpression (start, end) offsets within the
    device name.
    <numexpr> The number of elements in <<regexpr>>.  
    [RETURNS] Nothing.
*/
{
    mode_t new_mode;
    struct get_variable_info gv_info;
    struct stat source_stat, dest_stat;
    char source[STRING_LENGTH], destination[STRING_LENGTH];

    if ( (info->type == DEVFSD_NOTIFY_CHANGE) && S_ISLNK (info->mode) ) return;
    gv_info.info = info;
    gv_info.devname = info->devname;
    snprintf (gv_info.devpath, sizeof (gv_info.devpath), "%s/%s",
	      mount_point, info->devname);
    expand_expression (source, STRING_LENGTH, entry->u.copy.source,
		       get_variable, &gv_info, gv_info.devname,
		       regexpr, numexpr, NULL);
    expand_expression (destination, STRING_LENGTH, entry->u.copy.destination,
		       get_variable, &gv_info, gv_info.devname,
		       regexpr, numexpr, NULL);
    if (trace_level > 1)
	fprintf (stderr, "Copying %s to %s for \"%s\" | \"%s\"\n",
		 source, destination, info->devname, gv_info.devpath);
    if ( !make_dir_tree (destination) )
    {
	SYSLOG (LOG_ERR, "error making tree for: \"%s\"\n", destination);
	return;
    }
    if (lstat (source, &source_stat) != 0) return;
    if (lstat (destination, &dest_stat) != 0) dest_stat.st_mode = 0;
    new_mode = source_stat.st_mode & ~S_ISVTX;
    if (info->type == DEVFSD_NOTIFY_CREATE) new_mode |= S_ISVTX;
    else if ( (info->type == DEVFSD_NOTIFY_CHANGE) &&
	      (dest_stat.st_mode & S_ISVTX) ) new_mode |= S_ISVTX;
    if ( !copy_inode (destination, &dest_stat, new_mode, source,&source_stat) )
	SYSLOG (LOG_ERR, "error copying: \"%s\" to \"%s\"\n",
		source, destination);
}   /*  End Function action_copy  */

static void action_compat (const struct devfsd_notify_struct *info,
			   unsigned int action)
/*  [SUMMARY] Process a compatibility request.
    <info> The devfs change.
    <action> The action to take.
    [RETURNS] Nothing.
*/
{
    const char *compat_name = NULL;
    const char *dest_name = info->devname;
    char *ptr;
    char compat_buf[STRING_LENGTH], dest_buf[STRING_LENGTH];
    static char function_name[] = "action_compat";

    /*  First construct compatibility name  */
    switch (action)
    {
      case AC_MKOLDCOMPAT:
      case AC_RMOLDCOMPAT:
	compat_name = get_old_name (info->devname, info->namelen, compat_buf,
				    info->major, info->minor);
	break;
      case AC_MKNEWCOMPAT:
      case AC_RMNEWCOMPAT:
	if (strncmp (info->devname, "scsi/", 5) == 0)
	{
	    int mode, host, bus, target, lun;

	    sscanf (info->devname + 5, "host%d/bus%d/target%d/lun%d/",
		    &host, &bus, &target, &lun);
	    compat_name = compat_buf;
	    snprintf (dest_buf, sizeof (dest_buf), "../%s", info->devname);
	    dest_name = dest_buf;
	    if (strncmp (ptr = (strrchr (info->devname, '/') + 1), "mt", 2)
		== 0)
	    {
		char rewind = info->devname[info->namelen - 1];

		if (rewind != 'n') rewind = '\0';
		switch (ptr[2])
		{
		  default:
		    mode = 0;
		    break;
		  case 'l':
		    mode = 1;
		    break;
		  case 'm':
		    mode = 2;
		    break;
		  case 'a':
		    mode = 3;
		    break;
		}
		sprintf (compat_buf, "st/c%db%dt%du%dm%d%c",
			 host, bus, target, lun, mode, rewind);
	    }
	    else if (strcmp (info->devname + info->namelen - 7,"generic") == 0)
		sprintf (compat_buf, "sg/c%db%dt%du%d",
			 host, bus, target, lun);
	    else if (strcmp (info->devname + info->namelen - 2, "cd") == 0)
		sprintf (compat_buf, "sr/c%db%dt%du%d",
			 host, bus, target, lun);
	    else if (strcmp (info->devname + info->namelen - 4, "disc") == 0)
		sprintf (compat_buf, "sd/c%db%dt%du%d",
			 host, bus, target, lun);
	    else if (strncmp (ptr = (strrchr (info->devname, '/') + 1), "part",
			      4) == 0)
		sprintf ( compat_buf, "sd/c%db%dt%du%dp%d",
			  host, bus, target, lun, atoi (ptr + 4) );
	    else compat_name = NULL;
	}
	else if (strncmp (info->devname, "ide/host", 8) == 0)
	{
	    int host, bus, target, lun;

	    sscanf (info->devname + 4, "host%d/bus%d/target%d/lun%d/",
		    &host, &bus, &target, &lun);
	    compat_name = compat_buf;
	    snprintf (dest_buf, sizeof (dest_buf), "../%s", info->devname + 4);
	    dest_name = dest_buf;
	    if (strcmp (info->devname + info->namelen - 4, "disc") == 0)
		sprintf (compat_buf, "ide/hd/c%db%dt%du%d",
			 host, bus, target, lun);
	    else if (strncmp (ptr = (strrchr (info->devname, '/') + 1), "part",
			      4) == 0)
		sprintf ( compat_buf, "ide/hd/c%db%dt%du%dp%d",
			  host, bus, target, lun, atoi (ptr + 4) );
	    else if (strcmp (info->devname + info->namelen - 2, "cd") == 0)
		sprintf (compat_buf, "ide/cd/c%db%dt%du%d",
			 host, bus, target,lun);
	    else if (strncmp (ptr = (strrchr (info->devname, '/') + 1), "mt",
			      2) == 0)
		snprintf (compat_buf, sizeof (compat_buf),
			  "ide/mt/c%db%dt%du%d%s",
			  host, bus, target, lun, ptr + 2);
	    else compat_name = NULL;
	}
	break;
    }
    if (compat_name == NULL) return;
    /*  Now decide what to do with it  */
    switch (action)
    {
      case AC_MKOLDCOMPAT:
      case AC_MKNEWCOMPAT:
	if (mksymlink (dest_name, compat_name) == 0)
	    if (trace_level > 1)
		fprintf (stderr, "made symlink: \"%s\" for dev: %u,%u\n",
			compat_name, info->major, info->minor);
	break;
      case AC_RMOLDCOMPAT:
      case AC_RMNEWCOMPAT:
	if (unlink (compat_name) != 0)
	{
	    SYSLOG (LOG_ERR, "%s: error unlinking: \"%s\"\t%s\n",
		    function_name, compat_name, ERRSTRING);
	}
	else if (trace_level > 1)
	    fprintf (stderr, "unlinked: \"%s\"\n", compat_name);
	break;
    }
}   /*  End Function action_compat  */

static void do_restore (const char *dirname, int rootlen)
/*  [SUMMARY] Restore state from a directory.
    <dirname> The directory containing the backing store.
    <rootlen> The length of the root of the state directory hierarchy.
    [RETURNS] Nothing.
*/
{
    DIR *dp;
    struct dirent *de;

    if ( ( dp = opendir (dirname) ) == NULL )
    {
	SYSLOG (LOG_ERR, "Error opening directory \"%s\"\t%s\n",
		dirname, ERRSTRING);
	return;
    }
    while ( (de = readdir (dp) ) != NULL )
    {
	mode_t new_mode;
	struct stat source_stat, dest_stat;
	char spath[STRING_LENGTH], dpath[STRING_LENGTH];

	if ( (strcmp (de->d_name, ".") == 0) ||
	     (strcmp (de->d_name, "..") == 0) ) continue;
	snprintf (spath, sizeof spath, "%s/%s", dirname, de->d_name);
	if (lstat (spath, &source_stat) != 0)
	{
	    SYSLOG (LOG_ERR, "Error lstat(2)ing file \"%s\"\t%s\n",
		    spath, ERRSTRING);
	    continue;
	}
	snprintf (dpath, sizeof dpath, "%s%s", mount_point, spath + rootlen);
	if (lstat (dpath, &dest_stat) != 0) dest_stat.st_mode = 0;
	new_mode = source_stat.st_mode & ~S_ISVTX;
	if ( S_ISLNK (source_stat.st_mode) || (source_stat.st_mode & S_ISVTX) )
	    copy_inode (dpath, &dest_stat, new_mode, spath, &source_stat);
	if ( S_ISDIR (source_stat.st_mode) ) do_restore (spath, rootlen);
    }
    closedir (dp);
}   /*  End Function do_restore  */

static flag copy_inode (const char *destpath, const struct stat *dest_stat,
			mode_t new_mode,
			const char *sourcepath, const struct stat *source_stat)
/*  [SUMMARY] Copy an inode.
    <destpath> The destination path. An existing inode may be deleted.
    <dest_stat> The destination stat(2) information.
    <new_mode> The desired new mode for the destination.
    <sourcepath> The source path.
    <source_stat> The source stat(2) information.
    [RETURNS] TRUE on success, else FALSE.
*/
{
    if ( (source_stat->st_mode & S_IFMT) == (dest_stat->st_mode & S_IFMT) )
    {
	/*  Same type  */
	if ( S_ISLNK (source_stat->st_mode) )
	{
	    int source_len, dest_len;
	    char source_link[STRING_LENGTH], dest_link[STRING_LENGTH];

	    if ( ( source_len = readlink (sourcepath, source_link,
					  STRING_LENGTH - 1) ) < 0 )
		return (FALSE);
	    source_link[source_len] = '\0';
	    if ( ( dest_len = readlink (destpath, dest_link,
					STRING_LENGTH - 1) ) < 0 )
		return (FALSE);
	    dest_link[dest_len] = '\0';
	    if ( (source_len != dest_len) ||
		 (strcmp (source_link, dest_link) != 0) )
	    {
		unlink (destpath);
		symlink (source_link, destpath);
	    }
	    return (TRUE);
	}   /*  Else not a symlink  */
	if (new_mode != dest_stat->st_mode)
	    chmod (destpath, new_mode & ~S_IFMT);
	if ( (source_stat->st_uid != dest_stat->st_uid) ||
	     (source_stat->st_gid != dest_stat->st_gid) )
	    chown (destpath, source_stat->st_uid, source_stat->st_gid);
	return (TRUE);
    }
    /*  Different types: unlink and create  */