ProFTPD Developer's Guide: mod_quotatab Structure

ProFTPD Version 1.2

The following data structures are all declared in mod_quotatab.h, but are provided here for ease of cross-reference.

Quota "client" types:

typedef enum {
  all_quota = 10,
  user_quota = 20,
  group_quota = 30,
  class_quota = 40
} quota_type_t;

Quota byte limit types. A "hard" limit is imposed by deleting any file that causes the tally to go over the configured limit. A "soft" limit will allow that file to exist, but will not allow further uploads.

typedef enum {
  hard_limit = 1,
  soft_limit = 2
} quota_limit_type_t;

The quota limit structure:

typedef struct {

  /* Name refers to user, group, or class */
  char name[81];

  quota_type_t quota_type;

  /* Are quotas enforced per session or not? */
  unsigned char quota_per_session;

  /* Are byte quotas hard or soft? */
  quota_limit_type_t quota_limit_type;

  /* Configured bytes limits. */
  double bytes_in_avail;
  double bytes_out_avail;
  double bytes_xfer_avail;

  /* Configured files limits.  These have no "limit type", as they are
   * always hard.
   */
  unsigned long files_in_avail;
  unsigned long files_out_avail;
  unsigned long files_xfer_avail;

} quota_limit_t;

The quota tally structure:

typedef struct {
  char name[81];

  quota_type_t quota_type;

  /* Current bytes tallies. */
  double bytes_in_used;
  double bytes_out_used;
  double bytes_xfer_used;

  /* Current files tallies. */
  unsigned long files_in_used;
  unsigned long files_out_used;
  unsigned long files_xfer_used;

} quota_tally_t;

Quota table type (i.e. limit or tally):

typedef enum {
  type_limit = 100,
  type_tally
} quota_tabtype_t;

Quota display units:

typedef enum {
  byte = 10,
  kilo,
  mega,
  giga
} quota_units_t;

Quota deltas structure. These are used to track the changes in tallies per-operation (e.g. for each APPE, RETR, STOR, or STOU). This structure is useful for some submodules (e.g. mod_quotatab_sql) that are more interested in the deltas, rather than in the current absolute tallies values.

typedef struct {

  /* Deltas of bytes tallies. */
  double bytes_in_delta;
  double bytes_out_delta;
  double bytes_xfer_delta;

  /* Deltas of files tallies. */
  unsigned long files_in_delta;
  unsigned long files_out_delta;
  unsigned long files_xfer_delta;

} quota_deltas_t;

This is just an interim quota table abstraction, to be used until Confstreams are added to the core proftpd code.

typedef struct table_obj {

  /* Memory pool for this object. */
  pool *tab_pool;

  /* Table type, limit or tally. */
  quota_tabtype_t tab_type;

  /* Table handle */
  int tab_handle;

  /* Table "magic" number.  Often used for the verification process. */
  unsigned long tab_magic;

  /* Table record length */
  unsigned int tab_quotalen;

  /* Arbitrary data pointer */
  void *tab_data;

  /* Table I/O routines */
  int (*tab_close)(struct table_obj *);
  int (*tab_create)(struct table_obj *);
  unsigned char (*tab_lookup)(struct table_obj *, const char *, quota_type_t);
  int (*tab_read)(struct table_obj *);
  unsigned char (*tab_verify)(struct table_obj *);
  int (*tab_write)(struct table_obj *);

  /* Table locking routines */
  struct flock tab_lock;
  int (*tab_rlock)(struct table_obj *);
  int (*tab_unlock)(struct table_obj *);
  int (*tab_wlock)(struct table_obj *);

} quota_table_t;

The header file also defines some instances of the above structures that have scope for mod_quotatab and its submodules. These structures are used as the key in-memory storage locations for quota information:

  quota_limit_t quotatab_limit;
  quota_tally_t quotatab_tally;
  quota_deltas_t quotatab_deltas;