X-Git-Url: http://git.tuebingen.mpg.de/?p=adu.git;a=blobdiff_plain;f=user.c;h=8959c847b0b2069c76965850fc2acc07a8cfa097;hp=497af156905862fda844d81d832deb2ac39702d7;hb=4e757d60f7642c61e09a20a2a1de442b23208966;hpb=f140630786827b6405f62a4a8871a48a64325cc5

diff --git a/user.c b/user.c
index 497af15..8959c84 100644
--- a/user.c
+++ b/user.c
@@ -4,7 +4,7 @@
  * 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() */
@@ -29,6 +29,7 @@ struct uid_range {
 	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. */
@@ -38,6 +39,7 @@ enum uid_info_flags {
 	/** Whether this uid should be taken into account. */
 	UI_FL_ADMISSIBLE = 2,
 };
+
 /*
  * Contains info for each user that owns at least one regular file.
  *
@@ -50,8 +52,11 @@ static struct user_info *uid_hash_table;
 /** 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.
@@ -141,6 +146,15 @@ out:
 	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;
@@ -189,6 +203,22 @@ out:
 	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)
 {
@@ -246,7 +276,7 @@ static int open_user_table(struct user_info *ui, int create)
 	if (pw && pw->pw_name)
 		ui->pw_name = adu_strdup(pw->pw_name);
 
-	DEBUG_LOG("opening table for uid %u\n", (unsigned)ui->uid);
+	INFO_LOG("opening table for uid %u\n", (unsigned)ui->uid);
 	if (create) {
 		ret = osl(osl_create_table(ui->desc));
 		if (ret < 0)
@@ -270,17 +300,33 @@ err:
 	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;
@@ -296,9 +342,14 @@ int for_each_admissible_user(int (*func)(struct user_info *, void *),
 
 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)
@@ -312,7 +363,7 @@ void close_user_tables(void)
 			continue;
 		if (!ui->table)
 			continue;
-		DEBUG_LOG("closing user table for uid %u\n", (unsigned)ui->uid);
+		INFO_LOG("closing user table for uid %u\n", (unsigned)ui->uid);
 		ret = osl(osl_close_table(ui->table, OSL_MARK_CLEAN));
 		if (ret < 0)
 			ERROR_LOG("failed to close user table %u: %s\n",
@@ -330,11 +381,13 @@ 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.
  *
@@ -346,7 +399,7 @@ void close_user_tables(void)
  * 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)
 {
@@ -387,13 +440,49 @@ static char *get_uid_list_name(void)
 	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)
+{
+	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 *))
 {
-	qsort(uid_hash_table, uid_hash_table_size, sizeof(struct user_info),
-		comp);
+	hash_table_comparator = comp;
+	qsort(uid_hash_table_sort_idx, uid_hash_table_size,
+		sizeof(*uid_hash_table_sort_idx), comp_wrapper);
 }
 
-int read_uid_file(struct uid_range *admissible_uids)
+int open_admissible_user_tables(struct uid_range *admissible_uids)
+{
+	struct user_info *ui;
+
+	assert(uid_hash_table);
+	DEBUG_LOG("size: %d\n", uid_hash_table_size);
+	FOR_EACH_USER(ui) {
+		int ret;
+
+		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;
+			continue;
+		}
+		ui->flags |= UI_FL_ADMISSIBLE;
+		if (ui->table)
+			continue;
+		ret = open_user_table(ui, 0);
+		if (ret < 0)
+			return ret;
+	}
+	return 1;
+}
+
+int read_uid_file(void)
 {
 	size_t size;
 	uint32_t n;
@@ -423,17 +512,11 @@ int read_uid_file(struct uid_range *admissible_uids)
 		assert(ui);
 		if (ui_used(ui)) { /* impossible */
 			ERROR_LOG("duplicate user id!?\n");
-			ret =-EFAULT;
+			ret = -EFAULT;
 			goto out;
 		}
 		ui->uid = uid;
 		ui->flags |= UI_FL_SLOT_USED;
-		if (!uid_is_admissible(uid, admissible_uids))
-			continue;
-		ui->flags |= UI_FL_ADMISSIBLE;
-		ret = open_user_table(ui, 0);
-		if (ret < 0)
-			return ret;
 	}
 	ret = 1;
 out: