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-rw-r--r--src/lib/cursor.c461
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diff --git a/src/lib/cursor.c b/src/lib/cursor.c
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+/*
+ * This program is is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 of the
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+/**
+ * $Id$
+ *
+ * @file cursor.c
+ * @brief Functions to iterate over collections of VALUE_PAIRs
+ *
+ * @note Do not modify collections of VALUE_PAIRs pointed to be a cursor
+ * with none fr_cursor_* functions, during the lifetime of that cursor.
+ *
+ * @author Arran Cudbard-Bell <a.cudbardb@freeradius.org>
+ * @copyright 2013-2015 Arran Cudbard-Bell <a.cudbardb@freeradius.org>
+ * @copyright 2013-2015 The FreeRADIUS Server Project.
+ */
+
+#include <freeradius-devel/libradius.h>
+
+/** Internal function to update cursor state
+ *
+ * @param cursor to operate on.
+ * @param vp to set current and found positions to.
+ * @return value passed in as vp.
+ */
+inline static VALUE_PAIR *fr_cursor_update(vp_cursor_t *cursor, VALUE_PAIR *vp)
+{
+ if (!vp) {
+ cursor->next = NULL;
+ cursor->current = NULL;
+
+ return NULL;
+ }
+
+ cursor->next = vp->next;
+ cursor->current = vp;
+ cursor->found = vp;
+
+ return vp;
+}
+
+/** Setup a cursor to iterate over attribute pairs
+ *
+ * @param cursor Where to initialise the cursor (uses existing structure).
+ * @param const_vp to start from.
+ * @return the attribute pointed to by vp.
+ */
+VALUE_PAIR *fr_cursor_init(vp_cursor_t *cursor, VALUE_PAIR * const *const_vp)
+{
+ VALUE_PAIR **vp;
+
+ if (!const_vp || !cursor) {
+ return NULL;
+ }
+
+ memset(cursor, 0, sizeof(*cursor));
+
+ memcpy(&vp, &const_vp, sizeof(vp)); /* stupid const hacks */
+
+ /*
+ * Useful check to see if uninitialised memory is pointed
+ * to by vp
+ */
+#ifndef NDEBUG
+ if (*vp) VERIFY_VP(*vp);
+#endif
+ memcpy(&cursor->first, &vp, sizeof(cursor->first));
+ cursor->current = *cursor->first;
+
+ if (cursor->current) {
+ VERIFY_VP(cursor->current);
+ cursor->next = cursor->current->next;
+ }
+
+ return cursor->current;
+}
+
+/** Copy a cursor
+ *
+ * @param in Cursor to copy.
+ * @param out Where to copy the cursor to.
+ */
+void fr_cursor_copy(vp_cursor_t *out, vp_cursor_t *in)
+{
+ memcpy(out, in, sizeof(*out));
+}
+
+/** Rewind cursor to the start of the list
+ *
+ * @param cursor to operate on.
+ * @return the VALUE_PAIR at the start of the list.
+ */
+VALUE_PAIR *fr_cursor_first(vp_cursor_t *cursor)
+{
+ if (!cursor->first) return NULL;
+
+ cursor->current = *cursor->first;
+
+ if (cursor->current) {
+ VERIFY_VP(cursor->current);
+ cursor->next = cursor->current->next;
+ if (cursor->next) VERIFY_VP(cursor->next);
+ cursor->found = NULL;
+ }
+
+ return cursor->current;
+}
+
+/** Wind cursor to the last pair in the list
+ *
+ * @param cursor to operate on.
+ * @return the VALUE_PAIR at the end of the list.
+ */
+VALUE_PAIR *fr_cursor_last(vp_cursor_t *cursor)
+{
+ if (!cursor->first || !*cursor->first) return NULL;
+
+ /* Need to start at the start */
+ if (!cursor->current) fr_cursor_first(cursor);
+
+ /* Wind to the end */
+ while (cursor->next) fr_cursor_next(cursor);
+
+ return cursor->current;
+}
+
+/** Iterate over a collection of VALUE_PAIRs of a given type in the pairlist
+ *
+ * Find the next attribute of a given type. If no fr_cursor_next_by_* function
+ * has been called on a cursor before, or the previous call returned
+ * NULL, the search will start with the current attribute. Subsequent calls to
+ * fr_cursor_next_by_* functions will start the search from the previously
+ * matched attribute.
+ *
+ * @param cursor to operate on.
+ * @param attr number to match.
+ * @param vendor number to match (0 for none vendor attribute).
+ * @param tag to match. Either a tag number or TAG_ANY to match any tagged or
+ * untagged attribute, TAG_NONE to match attributes without tags.
+ * @return the next matching VALUE_PAIR, or NULL if no VALUE_PAIRs match.
+ */
+VALUE_PAIR *fr_cursor_next_by_num(vp_cursor_t *cursor, unsigned int attr, unsigned int vendor, int8_t tag)
+{
+ VALUE_PAIR *i;
+
+ if (!cursor->first) return NULL;
+
+ for (i = !cursor->found ? cursor->current : cursor->found->next;
+ i != NULL;
+ i = i->next) {
+ VERIFY_VP(i);
+ if ((i->da->attr == attr) && (i->da->vendor == vendor) &&
+ (!i->da->flags.has_tag || TAG_EQ(tag, i->tag))) {
+ break;
+ }
+ }
+
+ return fr_cursor_update(cursor, i);
+}
+
+/** Iterate over attributes of a given DA in the pairlist
+ *
+ * Find the next attribute of a given type. If no fr_cursor_next_by_* function
+ * has been called on a cursor before, or the previous call returned
+ * NULL, the search will start with the current attribute. Subsequent calls to
+ * fr_cursor_next_by_* functions will start the search from the previously
+ * matched attribute.
+ *
+ * @note DICT_ATTR pointers are compared, not the attribute numbers and vendors.
+ *
+ * @param cursor to operate on.
+ * @param da to match.
+ * @param tag to match. Either a tag number or TAG_ANY to match any tagged or
+ * untagged attribute, TAG_NONE to match attributes without tags.
+ * @return the next matching VALUE_PAIR, or NULL if no VALUE_PAIRs match.
+ */
+VALUE_PAIR *fr_cursor_next_by_da(vp_cursor_t *cursor, DICT_ATTR const *da, int8_t tag)
+{
+ VALUE_PAIR *i;
+
+ if (!cursor->first) return NULL;
+
+ for (i = !cursor->found ? cursor->current : cursor->found->next;
+ i != NULL;
+ i = i->next) {
+ VERIFY_VP(i);
+ if ((i->da == da) &&
+ (!i->da->flags.has_tag || TAG_EQ(tag, i->tag))) {
+ break;
+ }
+ }
+
+ return fr_cursor_update(cursor, i);
+}
+
+/** Advanced the cursor to the next VALUE_PAIR
+ *
+ * @param cursor to operate on.
+ * @return the next VALUE_PAIR, or NULL if no more VALUE_PAIRS in the collection.
+ */
+VALUE_PAIR *fr_cursor_next(vp_cursor_t *cursor)
+{
+ if (!cursor->first) return NULL;
+
+ cursor->current = cursor->next;
+ if (cursor->current) {
+ VERIFY_VP(cursor->current);
+
+ /*
+ * Set this now in case 'current' gets freed before
+ * fr_cursor_next is called again.
+ */
+ cursor->next = cursor->current->next;
+
+ /*
+ * Next call to fr_cursor_next_by_num will start from the current
+ * position in the list, not the last found instance.
+ */
+ cursor->found = NULL;
+ }
+
+ return cursor->current;
+}
+
+/** Return the next VALUE_PAIR without advancing the cursor
+ *
+ * @param cursor to operate on.
+ * @return the next VALUE_PAIR, or NULL if no more VALUE_PAIRS in the collection.
+ */
+VALUE_PAIR *fr_cursor_next_peek(vp_cursor_t *cursor)
+{
+ return cursor->next;
+}
+
+/** Return the VALUE_PAIR the cursor current points to
+ *
+ * @param cursor to operate on.
+ * @return the VALUE_PAIR the cursor currently points to.
+ */
+VALUE_PAIR *fr_cursor_current(vp_cursor_t *cursor)
+{
+ if (cursor->current) VERIFY_VP(cursor->current);
+
+ return cursor->current;
+}
+
+/** Insert a single VALUE_PAIR at the end of the list
+ *
+ * @note Will not advance cursor position to new attribute, but will set cursor
+ * to this attribute, if it's the first one in the list.
+ *
+ * Insert a VALUE_PAIR at the end of the list.
+ *
+ * @param cursor to operate on.
+ * @param vp to insert.
+ */
+void fr_cursor_insert(vp_cursor_t *cursor, VALUE_PAIR *vp)
+{
+ VALUE_PAIR *i;
+
+ if (!fr_assert(cursor->first)) return; /* cursor must have been initialised */
+
+ if (!vp) return;
+
+ VERIFY_VP(vp);
+
+ /*
+ * Only allow one VP to by inserted at a time
+ */
+ vp->next = NULL;
+
+ /*
+ * Cursor was initialised with a pointer to a NULL value_pair
+ */
+ if (!*cursor->first) {
+ *cursor->first = vp;
+ cursor->current = vp;
+
+ return;
+ }
+
+ /*
+ * We don't yet know where the last VALUE_PAIR is
+ *
+ * Assume current is closer to the end of the list and
+ * use that if available.
+ */
+ if (!cursor->last) cursor->last = cursor->current ? cursor->current : *cursor->first;
+
+ VERIFY_VP(cursor->last);
+
+ /*
+ * Wind last to the end of the list.
+ */
+ if (cursor->last->next) {
+ for (i = cursor->last; i; i = i->next) {
+ VERIFY_VP(i);
+ cursor->last = i;
+ }
+ }
+
+ /*
+ * Either current was never set, or something iterated to the
+ * end of the attribute list. In both cases the newly inserted
+ * VALUE_PAIR should be set as the current VALUE_PAIR.
+ */
+ if (!cursor->current) cursor->current = vp;
+
+ /*
+ * Add the VALUE_PAIR to the end of the list
+ */
+ cursor->last->next = vp;
+ cursor->last = vp; /* Wind it forward a little more */
+
+ /*
+ * If the next pointer was NULL, and the VALUE_PAIR
+ * just added has a next pointer value, set the cursor's next
+ * pointer to the VALUE_PAIR's next pointer.
+ */
+ if (!cursor->next) cursor->next = cursor->current->next;
+}
+
+/** Merges multiple VALUE_PAIR into the cursor
+ *
+ * Add multiple VALUE_PAIR from add to cursor.
+ *
+ * @param cursor to insert VALUE_PAIRs with
+ * @param add one or more VALUE_PAIRs (may be NULL, which results in noop).
+ */
+void fr_cursor_merge(vp_cursor_t *cursor, VALUE_PAIR *add)
+{
+ vp_cursor_t from;
+ VALUE_PAIR *vp;
+
+ if (!add) return;
+
+ if (!fr_assert(cursor->first)) return; /* cursor must have been initialised */
+
+ for (vp = fr_cursor_init(&from, &add);
+ vp;
+ vp = fr_cursor_next(&from)) {
+ fr_cursor_insert(cursor, vp);
+ }
+}
+
+/** Remove the current pair
+ *
+ * @todo this is really inefficient and should be fixed...
+ *
+ * The current VP will be set to the one before the VP being removed,
+ * this is so the commonly used check and remove loop (below) works
+ * as expected.
+ @code {.c}
+ for (vp = fr_cursor_init(&cursor, head);
+ vp;
+ vp = fr_cursor_next(&cursor) {
+ if (<condition>) {
+ vp = fr_cursor_remove(&cursor);
+ talloc_free(vp);
+ }
+ }
+ @endcode
+ *
+ * @param cursor to remove the current pair from.
+ * @return NULL on error, else the VALUE_PAIR that was just removed.
+ */
+VALUE_PAIR *fr_cursor_remove(vp_cursor_t *cursor)
+{
+ VALUE_PAIR *vp, *before;
+
+ if (!fr_assert(cursor->first)) return NULL; /* cursor must have been initialised */
+
+ vp = cursor->current;
+ if (!vp) return NULL;
+
+ /*
+ * Where VP is head of the list
+ */
+ if (*(cursor->first) == vp) {
+ *(cursor->first) = vp->next;
+ cursor->current = vp->next;
+ cursor->next = vp->next ? vp->next->next : NULL;
+ before = NULL;
+ goto fixup;
+ }
+
+ /*
+ * Where VP is not head of the list
+ */
+ before = *(cursor->first);
+ if (!before) return NULL;
+
+ /*
+ * Find the VP immediately preceding the one being removed
+ */
+ while (before->next != vp) before = before->next;
+
+ cursor->next = before->next = vp->next; /* close the gap */
+ cursor->current = before; /* current jumps back one, but this is usually desirable */
+
+fixup:
+ vp->next = NULL; /* limit scope of fr_pair_list_free() */
+
+ /*
+ * Fixup cursor->found if we removed the VP it was referring to,
+ * and point to the previous one.
+ */
+ if (vp == cursor->found) cursor->found = before;
+
+ /*
+ * Fixup cursor->last if we removed the VP it was referring to
+ */
+ if (vp == cursor->last) cursor->last = cursor->current;
+ return vp;
+}
+
+/** Replace the current pair
+ *
+ * @todo this is really inefficient and should be fixed...
+ *
+ * @param cursor to replace the current pair in.
+ * @param new VALUE_PAIR to insert.
+ * @return NULL on error, else the VALUE_PAIR we just replaced.
+ */
+VALUE_PAIR *fr_cursor_replace(vp_cursor_t *cursor, VALUE_PAIR *new)
+{
+ VALUE_PAIR *vp, **last;
+
+ if (!fr_assert(cursor->first)) return NULL; /* cursor must have been initialised */
+
+ vp = cursor->current;
+ if (!vp) {
+ *cursor->first = new;
+ return NULL;
+ }
+
+ last = cursor->first;
+ while (*last != vp) {
+ last = &(*last)->next;
+ }
+
+ fr_cursor_next(cursor); /* Advance the cursor past the one were about to replace */
+
+ *last = new;
+ new->next = vp->next;
+ vp->next = NULL;
+
+ return vp;
+}
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