* Licensed under the GPL v2. For licencing details see COPYING.
*/
-/** \file user.c uid User and user ID handling. */
+/** \file user.c \brief User and user ID handling. */
#include "adu.h"
#include <dirent.h> /* readdir() */
uint32_t high;
};
+/** Iterate over all uid ranges. */
#define FOR_EACH_UID_RANGE(ur, urs) for (ur = urs; ur->low <= ur->high; ur++)
/** Flags for the user hash table. */
/** Whether this uid should be taken into account. */
UI_FL_ADMISSIBLE = 2,
};
+
/*
* Contains info for each user that owns at least one regular file.
*
/** This is always a power of two. It is set in create_hash_table(). */
static uint32_t uid_hash_table_size;
+/* Array of indices to the entries of \a uid_hash_table. */
+static int *uid_hash_table_sort_idx;
+
/** The number of used slots in the hash table. */
-static uint32_t num_uids = 0;
+static uint32_t num_uids;
/*
* The columns of the per-user tables.
return ret;
}
+/**
+ * Convert the --uid argument to an array of uid ranges.
+ *
+ * \param orig_arg The argument to the --uid option.
+ * \param ur Result pointer.
+ *
+ * Returns Negative on errors. On success, the number of uid ranges
+ * is returned.
+ */
int parse_uid_arg(const char *orig_arg, struct uid_range **ur)
{
char *arg, **argv;
return ret;
}
+/**
+ * Add each given user to the array of admissible users.
+ *
+ * \param users Array of user names to add.
+ * \param num_users Length of \a users.
+ * \param admissible_uids The users which are already admissible.
+ * \param num_uid_ranges The number of intervals of \a admissible_uids.
+ *
+ * For each given user, the function checks whether that user is already
+ * admissible, i.e. its uid is contained in one of the ranges given by \a
+ * admissible_uids. If it is, the function ignores that user. Otherwise, a new
+ * length-one range consisting of that uid only is appended to \a
+ * admissible_uids.
+ *
+ * \return Negative on errors, the new number of uid ranges on success.
+ */
int append_users(char **users, int num_users,
struct uid_range **admissible_uids, int num_uid_ranges)
{
return ret;
}
+/** Iterate over each user in the uid hash table. */
#define FOR_EACH_USER(ui) for (ui = uid_hash_table; ui < \
uid_hash_table + uid_hash_table_size; ui++)
+
+/**
+ * Execute the given function for each admissible user.
+ *
+ * \param func The function to execute.
+ * \param data Arbitrary pointer.
+ *
+ * This function calls \a func for each admissible user in the uid hash table.
+ * The \a data pointer is passed as the second argument to \a func.
+ *
+ * \return As soon as \a func returns a negative value, the loop is terminated
+ * and that negative value is returned. Otherwise, the function returns 1.
+ */
int for_each_admissible_user(int (*func)(struct user_info *, void *),
void *data)
{
- struct user_info *ui;
+ int i;
assert(uid_hash_table);
- FOR_EACH_USER(ui) {
+ for (i = 0; i < uid_hash_table_size; i++) {
int ret;
+ struct user_info *ui = uid_hash_table +
+ uid_hash_table_sort_idx[i];
if (!ui_used(ui) || !ui_admissible(ui))
continue;
void create_hash_table(unsigned bits)
{
+ int i;
+
uid_hash_table_size = 1 << bits;
uid_hash_table = adu_calloc(uid_hash_table_size *
sizeof(struct user_info));
+ uid_hash_table_sort_idx = adu_malloc(uid_hash_table_size * sizeof(int));
+ for (i = 0; i < uid_hash_table_size; i++)
+ uid_hash_table_sort_idx[i] = i;
}
void close_user_tables(void)
}
free(uid_hash_table);
uid_hash_table = NULL;
+ free(uid_hash_table_sort_idx);
+ uid_hash_table_sort_idx = NULL;
}
/*
* We use a hash table of size s=2^uid_hash_bits to map the uids into the
- * interval [0..s]. Hash collisions are treated by open addressing, i.e.
+ * interval [0..s-1]. Hash collisions are treated by open addressing, i.e.
* unused slots in the table are used to store different uids that hash to the
* same slot.
*
* An odd number is sufficient to make sure each entry of the hash table gets
* probed for probe_num between 0 and s-1 because s is a power of two, hence
* the second hash value has never a common divisor with the hash table size.
- * IOW: h is invertible in the ring [0..s].
+ * IOW: h is invertible in the ring [0..s-1].
*/
static uint32_t double_hash(uint32_t uid, uint32_t probe_num)
{
return make_message("%s/uid_list", conf.database_dir_arg);
}
-void sort_hash_table(int (*comp)(const void *, const void *))
+static int (*hash_table_comparator)(struct user_info *a, struct user_info *b);
+
+static int comp_wrapper(const void *a, const void *b)
{
- qsort(uid_hash_table, uid_hash_table_size, sizeof(struct user_info),
- comp);
+ struct user_info *x = uid_hash_table + *(unsigned *)a;
+ struct user_info *y = uid_hash_table + *(unsigned *)b;
+ return hash_table_comparator(x, y);
+}
+
+void sort_hash_table(int (*comp)(struct user_info *, struct user_info *))
+{
+ hash_table_comparator = comp;
+ qsort(uid_hash_table_sort_idx, uid_hash_table_size,
+ sizeof(*uid_hash_table_sort_idx), comp_wrapper);
}
int open_admissible_user_tables(struct uid_range *admissible_uids)
FOR_EACH_USER(ui) {
int ret;
- if (!ui_used(ui)) {
+ if (!ui_used(ui))
continue;
- }
if (!uid_is_admissible(ui->uid, admissible_uids)) {
DEBUG_LOG("uid %u is not admissible\n", ui->uid);
ui->flags &= ~UI_FL_ADMISSIBLE;