Introduce include/libnetfilter_queue/linux_list.h and src/iftable.c.
These are not exact copies: all tractable checkpatch errors are fixed.
Also complete iftable.c kerneldoc to doxygen translation.
This commit doesn't actually do anything with the new files.
Signed-off-by: Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>
---
Changes in v2:
- This was originally patch 12 of 32
- Update commit message
- Don't copy src/rtnl.c since it's not kept
- Fix checkpatch errors on the fly.
- Finish kerneldoc xlation on the fly (was patch 16 of 32).
include/libnetfilter_queue/linux_list.h | 730 ++++++++++++++++++++++++
src/iftable.c | 355 ++++++++++++
2 files changed, 1085 insertions(+)
create mode 100644 include/libnetfilter_queue/linux_list.h
create mode 100644 src/iftable.c
diff --git a/include/libnetfilter_queue/linux_list.h b/include/libnetfilter_queue/linux_list.h
new file mode 100644
index 0000000..68637c3
--- /dev/null
+++ b/include/libnetfilter_queue/linux_list.h
@@ -0,0 +1,730 @@
+#ifndef _LINUX_LIST_H
+#define _LINUX_LIST_H
+
+#include <stddef.h>
+
+#undef offsetof
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+
+/**
+ * container_of - cast a member of a structure out to the containing structure
+ *
+ * @ptr: the pointer to the member.
+ * @type: the type of the container struct this is embedded in.
+ * @member: the name of the member within the struct.
+ *
+ */
+#define container_of(ptr, type, member) ({ \
+ typeof(((type *)0)->member) *__mptr = (ptr); \
+ (type *)((char *)__mptr - offsetof(type, member)); })
+
+/*
+ * Check at compile time that something is of a particular type.
+ * Always evaluates to 1 so you may use it easily in comparisons.
+ */
+#define typecheck(type, x) \
+({ type __dummy; \
+ typeof(x) __dummy2; \
+ (void)(&__dummy == &__dummy2); \
+ 1; \
+})
+
+#define prefetch(x) ((void)0)
+
+/* empty define to make this work in userspace -HW */
+#ifndef smp_wmb
+#define smp_wmb() /* Comment to placate checkpatch */
+#endif
+
+/*
+ * These are non-NULL pointers that will result in page faults
+ * under normal circumstances, used to verify that nobody uses
+ * non-initialized list entries.
+ */
+#define LIST_POISON1 ((void *) 0x00100100)
+#define LIST_POISON2 ((void *) 0x00200200)
+
+/*
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+struct list_head {
+ struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+ struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+ (ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add(struct list_head *new,
+ struct list_head *prev,
+ struct list_head *next)
+{
+ next->prev = new;
+ new->next = next;
+ new->prev = prev;
+ prev->next = new;
+}
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+ __list_add(new, head, head->next);
+}
+
+/**
+ * list_add_tail - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ */
+static inline void list_add_tail(struct list_head *new, struct list_head *head)
+{
+ __list_add(new, head->prev, head);
+}
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add_rcu(struct list_head *new,
+ struct list_head *prev, struct list_head *next)
+{
+ new->next = next;
+ new->prev = prev;
+ smp_wmb(); /* Comment to placate checkpatch */
+ next->prev = new;
+ prev->next = new;
+}
+
+/**
+ * list_add_rcu - add a new entry to rcu-protected list
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+static inline void list_add_rcu(struct list_head *new, struct list_head *head)
+{
+ __list_add_rcu(new, head, head->next);
+}
+
+/**
+ * list_add_tail_rcu - add a new entry to rcu-protected list
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_tail_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+static inline void list_add_tail_rcu(struct list_head *new,
+ struct list_head *head)
+{
+ __list_add_rcu(new, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_del(struct list_head *prev, struct list_head *next)
+{
+ next->prev = prev;
+ prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is
+ * in an undefined state.
+ */
+static inline void list_del(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+ entry->next = LIST_POISON1;
+ entry->prev = LIST_POISON2;
+}
+
+/**
+ * list_del_rcu - deletes entry from list without re-initialization
+ * @entry: the element to delete from the list.
+ *
+ * Note: list_empty on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking the list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_del_rcu()
+ * or list_add_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ *
+ * Note that the caller is not permitted to immediately free
+ * the newly deleted entry. Instead, either synchronize_kernel()
+ * or call_rcu() must be used to defer freeing until an RCU
+ * grace period has elapsed.
+ */
+static inline void list_del_rcu(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+ entry->prev = LIST_POISON2;
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry: the element to delete from the list.
+ */
+static inline void list_del_init(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+ INIT_LIST_HEAD(entry);
+}
+
+/**
+ * list_move - delete from one list and add as another's head
+ * @list: the entry to move
+ * @head: the head that will precede our entry
+ */
+static inline void list_move(struct list_head *list, struct list_head *head)
+{
+ __list_del(list->prev, list->next);
+ list_add(list, head);
+}
+
+/**
+ * list_move_tail - delete from one list and add as another's tail
+ * @list: the entry to move
+ * @head: the head that will follow our entry
+ */
+static inline void list_move_tail(struct list_head *list,
+ struct list_head *head)
+{
+ __list_del(list->prev, list->next);
+ list_add_tail(list, head);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head: the list to test.
+ */
+static inline int list_empty(const struct list_head *head)
+{
+ return head->next == head;
+}
+
+/**
+ * list_empty_careful - tests whether a list is
+ * empty _and_ checks that no other CPU might be
+ * in the process of still modifying either member
+ *
+ * NOTE: using list_empty_careful() without synchronization
+ * can only be safe if the only activity that can happen
+ * to the list entry is list_del_init(). Eg. it cannot be used
+ * if another CPU could re-list_add() it.
+ *
+ * @head: the list to test.
+ */
+static inline int list_empty_careful(const struct list_head *head)
+{
+ struct list_head *next = head->next;
+
+ return (next == head) && (next == head->prev);
+}
+
+static inline void __list_splice(struct list_head *list,
+ struct list_head *head)
+{
+ struct list_head *first = list->next;
+ struct list_head *last = list->prev;
+ struct list_head *at = head->next;
+
+ first->prev = head;
+ head->next = first;
+
+ last->next = at;
+ at->prev = last;
+}
+
+/**
+ * list_splice - join two lists
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static inline void list_splice(struct list_head *list, struct list_head *head)
+{
+ if (!list_empty(list))
+ __list_splice(list, head);
+}
+
+/**
+ * list_splice_init - join two lists and reinitialise the emptied list.
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ *
+ * The list at @list is reinitialised
+ */
+static inline void list_splice_init(struct list_head *list,
+ struct list_head *head)
+{
+ if (!list_empty(list)) {
+ __list_splice(list, head);
+ INIT_LIST_HEAD(list);
+ }
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr: the &struct list_head pointer.
+ * @type: the type of the struct this is embedded in.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+ container_of(ptr, type, member)
+
+/**
+ * list_for_each - iterate over a list
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ */
+#define list_for_each(pos, head) \
+ for (pos = (head)->next, prefetch(pos->next); pos != (head); \
+ pos = pos->next, prefetch(pos->next))
+
+/**
+ * __list_for_each - iterate over a list
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ *
+ * This variant differs from list_for_each() in that it's the
+ * simplest possible list iteration code, no prefetching is done.
+ * Use this for code that knows the list to be very short (empty
+ * or 1 entry) most of the time.
+ */
+#define __list_for_each(pos, head) \
+ for (pos = (head)->next; pos != (head); pos = pos->next)
+
+/**
+ * list_for_each_prev - iterate over a list backwards
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ */
+#define list_for_each_prev(pos, head) \
+ for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
+ pos = pos->prev, prefetch(pos->prev))
+
+/**
+ * list_for_each_safe - iterate over a list safe against removal of list entry
+ * @pos: the &struct list_head to use as a loop counter.
+ * @n: another &struct list_head to use as temporary storage
+ * @head: the head for your list.
+ */
+#define list_for_each_safe(pos, n, head) \
+ for (pos = (head)->next, n = pos->next; pos != (head); \
+ pos = n, n = pos->next)
+
+/**
+ * list_for_each_entry - iterate over list of given type
+ * @pos: the type * to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry(pos, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member), \
+ prefetch(pos->member.next); \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member), \
+ prefetch(pos->member.next))
+
+/**
+ * list_for_each_entry_reverse - iterate backwards over list of given type.
+ * @pos: the type * to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_reverse(pos, head, member) \
+ for (pos = list_entry((head)->prev, typeof(*pos), member), \
+ prefetch(pos->member.prev); \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.prev, typeof(*pos), member), \
+ prefetch(pos->member.prev))
+
+/**
+ * list_prepare_entry - prepare a pos entry for use as a start point in
+ * list_for_each_entry_continue
+ * @pos: the type * to use as a start point
+ * @head: the head of the list
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_prepare_entry(pos, head, member) \
+ ((pos) ? : list_entry(head, typeof(*pos), member))
+
+/**
+ * list_for_each_entry_continue - iterate over list of given type
+ * continuing after existing point
+ * @pos: the type * to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_continue(pos, head, member) \
+ for (pos = list_entry(pos->member.next, typeof(*pos), member), \
+ prefetch(pos->member.next); \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member), \
+ prefetch(pos->member.next))
+
+/**
+ * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @pos: the type * to use as a loop counter.
+ * @n: another type * to use as temporary storage
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe(pos, n, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member), \
+ n = list_entry(pos->member.next, typeof(*pos), member); \
+ &pos->member != (head); \
+ pos = n, n = list_entry(n->member.next, typeof(*n), member))
+
+/**
+ * list_for_each_rcu - iterate over an rcu-protected list
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_rcu(pos, head) \
+ for (pos = (head)->next, prefetch(pos->next); pos != (head); \
+ pos = pos->next, ({ smp_read_barrier_depends(); 0; }), prefetch(pos->next))
+
+#define __list_for_each_rcu(pos, head) \
+ for (pos = (head)->next; pos != (head); \
+ pos = pos->next, ({ smp_read_barrier_depends(); 0; }))
+
+/**
+ * list_for_each_safe_rcu - iterate over an rcu-protected list safe
+ * against removal of list entry
+ * @pos: the &struct list_head to use as a loop counter.
+ * @n: another &struct list_head to use as temporary storage
+ * @head: the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_safe_rcu(pos, n, head) \
+ for (pos = (head)->next, n = pos->next; pos != (head); \
+ pos = n, ({ smp_read_barrier_depends(); 0; }), n = pos->next)
+
+/**
+ * list_for_each_entry_rcu - iterate over rcu list of given type
+ * @pos: the type * to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_entry_rcu(pos, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member), \
+ prefetch(pos->member.next); \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member), \
+ ({ smp_read_barrier_depends(); 0; }), \
+ prefetch(pos->member.next))
+
+
+/**
+ * list_for_each_continue_rcu - iterate over an rcu-protected list
+ * continuing after existing point.
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define list_for_each_continue_rcu(pos, head) \
+ for ((pos) = (pos)->next, prefetch((pos)->next); (pos) != (head); \
+ (pos) = (pos)->next, ({ smp_read_barrier_depends(); 0; }), prefetch((pos)->next))
+
+/*
+ * Double linked lists with a single pointer list head.
+ * Mostly useful for hash tables where the two pointer list head is
+ * too wasteful.
+ * You lose the ability to access the tail in O(1).
+ */
+
+struct hlist_head {
+ struct hlist_node *first;
+};
+
+struct hlist_node {
+ struct hlist_node *next, **pprev;
+};
+
+#define HLIST_HEAD_INIT { .first = NULL }
+#define HLIST_HEAD(name) struct hlist_head name = { .first = NULL }
+#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
+#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)
+
+static inline int hlist_unhashed(const struct hlist_node *h)
+{
+ return !h->pprev;
+}
+
+static inline int hlist_empty(const struct hlist_head *h)
+{
+ return !h->first;
+}
+
+static inline void __hlist_del(struct hlist_node *n)
+{
+ struct hlist_node *next = n->next;
+ struct hlist_node **pprev = n->pprev;
+ *pprev = next;
+ if (next)
+ next->pprev = pprev;
+}
+
+static inline void hlist_del(struct hlist_node *n)
+{
+ __hlist_del(n);
+ n->next = LIST_POISON1;
+ n->pprev = LIST_POISON2;
+}
+
+/**
+ * hlist_del_rcu - deletes entry from hash list without re-initialization
+ * @n: the element to delete from the hash list.
+ *
+ * Note: list_unhashed() on entry does not return true after this,
+ * the entry is in an undefined state. It is useful for RCU based
+ * lockfree traversal.
+ *
+ * In particular, it means that we can not poison the forward
+ * pointers that may still be used for walking the hash list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_add_head_rcu()
+ * or hlist_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_for_each_entry().
+ */
+static inline void hlist_del_rcu(struct hlist_node *n)
+{
+ __hlist_del(n);
+ n->pprev = LIST_POISON2;
+}
+
+static inline void hlist_del_init(struct hlist_node *n)
+{
+ if (n->pprev) {
+ __hlist_del(n);
+ INIT_HLIST_NODE(n);
+ }
+}
+
+#define hlist_del_rcu_init hlist_del_init
+
+static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
+{
+ struct hlist_node *first = h->first;
+
+ n->next = first;
+ if (first)
+ first->pprev = &n->next;
+ h->first = n;
+ n->pprev = &h->first;
+}
+
+
+/**
+ * hlist_add_head_rcu - adds the specified element to the specified hlist,
+ * while permitting racing traversals.
+ * @n: the element to add to the hash list.
+ * @h: the list to add to.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_add_head_rcu()
+ * or hlist_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_for_each_entry(), but only if smp_read_barrier_depends()
+ * is used to prevent memory-consistency problems on Alpha CPUs.
+ * Regardless of the type of CPU, the list-traversal primitive
+ * must be guarded by rcu_read_lock().
+ *
+ * OK, so why don't we have an hlist_for_each_entry_rcu()???
+ */
+static inline void hlist_add_head_rcu(struct hlist_node *n,
+ struct hlist_head *h)
+{
+ struct hlist_node *first = h->first;
+
+ n->next = first;
+ n->pprev = &h->first;
+ smp_wmb(); /* Comment to placate checkpatch */
+ if (first)
+ first->pprev = &n->next;
+ h->first = n;
+}
+
+/* next must be != NULL */
+static inline void hlist_add_before(struct hlist_node *n,
+ struct hlist_node *next)
+{
+ n->pprev = next->pprev;
+ n->next = next;
+ next->pprev = &n->next;
+ *(n->pprev) = n;
+}
+
+static inline void hlist_add_after(struct hlist_node *n,
+ struct hlist_node *next)
+{
+ next->next = n->next;
+ n->next = next;
+ next->pprev = &n->next;
+
+ if (next->next)
+ next->next->pprev = &next->next;
+}
+
+#define hlist_entry(ptr, type, member) container_of(ptr, type, member)
+
+#define hlist_for_each(pos, head) \
+ for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
+ pos = pos->next)
+
+#define hlist_for_each_safe(pos, n, head) \
+ for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
+ pos = n)
+
+/**
+ * hlist_for_each_entry - iterate over list of given type
+ * @tpos: the type * to use as a loop counter.
+ * @pos: the &struct hlist_node to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry(tpos, pos, head, member) \
+ for (pos = (head)->first; \
+ pos && ({ prefetch(pos->next); 1; }) && \
+ ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \
+ pos = pos->next)
+
+/**
+ * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
+ * @tpos: the type * to use as a loop counter.
+ * @pos: the &struct hlist_node to use as a loop counter.
+ * @member: the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_continue(tpos, pos, member) \
+ for (pos = (pos)->next; \
+ pos && ({ prefetch(pos->next); 1; }) && \
+ ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \
+ pos = pos->next)
+
+/**
+ * hlist_for_each_entry_from - iterate over a hlist continuing from existing point
+ * @tpos: the type * to use as a loop counter.
+ * @pos: the &struct hlist_node to use as a loop counter.
+ * @member: the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_from(tpos, pos, member) \
+ for (; pos && ({ prefetch(pos->next); 1; }) && \
+ ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \
+ pos = pos->next)
+
+/**
+ * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @tpos: the type * to use as a loop counter.
+ * @pos: the &struct hlist_node to use as a loop counter.
+ * @n: another &struct hlist_node to use as temporary storage
+ * @head: the head for your list.
+ * @member: the name of the hlist_node within the struct.
+ */
+#define hlist_for_each_entry_safe(tpos, pos, n, head, member) \
+ for (pos = (head)->first; \
+ pos && ({ n = pos->next; 1; }) && \
+ ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \
+ pos = n)
+
+/**
+ * hlist_for_each_entry_rcu - iterate over rcu list of given type
+ * @pos: the type * to use as a loop counter.
+ * @pos: the &struct hlist_node to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the hlist_node within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as hlist_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define hlist_for_each_entry_rcu(tpos, pos, head, member) \
+ for (pos = (head)->first; \
+ pos && ({ prefetch(pos->next); 1; }) && \
+ ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \
+ pos = pos->next, ({ smp_read_barrier_depends(); 0; }))
+
+#endif
diff --git a/src/iftable.c b/src/iftable.c
new file mode 100644
index 0000000..4673001
--- /dev/null
+++ b/src/iftable.c
@@ -0,0 +1,355 @@
+/* iftable - table of network interfaces
+ *
+ * (C) 2004 by Astaro AG, written by Harald Welte <hwelte@xxxxxxxxxx>
+ * (C) 2008 by Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
+ * (C) 2024 by Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>
+ *
+ * This software is Free Software and licensed under GNU GPLv2+.
+ */
+
+/* IFINDEX handling */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <assert.h>
+
+#include <linux/netdevice.h>
+
+#include <libnfnetlink/libnfnetlink.h>
+#include "rtnl.h"
+#include "linux_list.h"
+
+/**
+ * \defgroup iftable Functions to manage a table of network interfaces
+ * These functions maintain a database of the name and flags of each
+ * network interface.
+ * @{
+ */
+
+struct ifindex_node {
+ struct list_head head;
+
+ uint32_t index;
+ uint32_t type;
+ uint32_t alen;
+ uint32_t flags;
+ char addr[8];
+ char name[16];
+};
+
+struct nlif_handle {
+ struct list_head ifindex_hash[16];
+ struct rtnl_handle *rtnl_handle;
+ struct rtnl_handler ifadd_handler;
+ struct rtnl_handler ifdel_handler;
+};
+
+/* iftable_add - Add/Update an entry to/in the interface table
+ * \param n: netlink message header of a RTM_NEWLINK message
+ * \param arg: not used
+ *
+ * This function adds/updates an entry in the intrface table.
+ * Returns -1 on error, 1 on success.
+ */
+static int iftable_add(struct nlmsghdr *n, void *arg)
+{
+ unsigned int hash, found = 0;
+ struct ifinfomsg *ifi_msg = NLMSG_DATA(n);
+ struct ifindex_node *this;
+ struct rtattr *cb[IFLA_MAX+1];
+ struct nlif_handle *h = arg;
+
+ if (n->nlmsg_type != RTM_NEWLINK)
+ return -1;
+
+ if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi_msg)))
+ return -1;
+
+ rtnl_parse_rtattr(cb, IFLA_MAX, IFLA_RTA(ifi_msg), IFLA_PAYLOAD(n));
+
+ if (!cb[IFLA_IFNAME])
+ return -1;
+
+ hash = ifi_msg->ifi_index & 0xF;
+ list_for_each_entry(this, &h->ifindex_hash[hash], head) {
+ if (this->index == ifi_msg->ifi_index) {
+ found = 1;
+ break;
+ }
+ }
+
+ if (!found) {
+ this = malloc(sizeof(*this));
+ if (!this)
+ return -1;
+
+ this->index = ifi_msg->ifi_index;
+ }
+
+ this->type = ifi_msg->ifi_type;
+ this->flags = ifi_msg->ifi_flags;
+ if (cb[IFLA_ADDRESS]) {
+ unsigned int alen;
+
+ this->alen = alen = RTA_PAYLOAD(cb[IFLA_ADDRESS]);
+ if (alen > sizeof(this->addr))
+ alen = sizeof(this->addr);
+ memcpy(this->addr, RTA_DATA(cb[IFLA_ADDRESS]), alen);
+ } else {
+ this->alen = 0;
+ memset(this->addr, 0, sizeof(this->addr));
+ }
+ strcpy(this->name, RTA_DATA(cb[IFLA_IFNAME]));
+
+ if (!found)
+ list_add(&this->head, &h->ifindex_hash[hash]);
+
+ return 1;
+}
+
+/* iftable_del - Delete an entry from the interface table
+ * \param n: netlink message header of a RTM_DELLINK nlmsg
+ * \param arg: not used
+ *
+ * Delete an entry from the interface table.
+ * Returns -1 on error, 0 if no matching entry was found or 1 on success.
+ */
+static int iftable_del(struct nlmsghdr *n, void *arg)
+{
+ struct ifinfomsg *ifi_msg = NLMSG_DATA(n);
+ struct rtattr *cb[IFLA_MAX+1];
+ struct nlif_handle *h = arg;
+ struct ifindex_node *this, *tmp;
+ unsigned int hash;
+
+ if (n->nlmsg_type != RTM_DELLINK)
+ return -1;
+
+ if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi_msg)))
+ return -1;
+
+ rtnl_parse_rtattr(cb, IFLA_MAX, IFLA_RTA(ifi_msg), IFLA_PAYLOAD(n));
+
+ hash = ifi_msg->ifi_index & 0xF;
+ list_for_each_entry_safe(this, tmp, &h->ifindex_hash[hash], head) {
+ if (this->index == ifi_msg->ifi_index) {
+ list_del(&this->head);
+ free(this);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * nlif_index2name - get the name for an ifindex
+ *
+ * \param h pointer to nlif_handle created by nlif_open()
+ * \param index ifindex to be resolved
+ * \param name interface name, pass a buffer of IFNAMSIZ size
+ * \return -1 on error, 1 on success
+ */
+int nlif_index2name(struct nlif_handle *h,
+ unsigned int index,
+ char *name)
+{
+ unsigned int hash;
+ struct ifindex_node *this;
+
+ assert(h != NULL);
+ assert(name != NULL);
+
+ if (index == 0) {
+ strcpy(name, "*");
+ return 1;
+ }
+
+ hash = index & 0xF;
+ list_for_each_entry(this, &h->ifindex_hash[hash], head) {
+ if (this->index == index) {
+ strcpy(name, this->name);
+ return 1;
+ }
+ }
+
+ errno = ENOENT;
+ return -1;
+}
+
+/**
+ * nlif_get_ifflags - get the flags for an ifindex
+ *
+ * \param h pointer to nlif_handle created by nlif_open()
+ * \param index ifindex to be resolved
+ * \param flags pointer to variable used to store the interface flags
+ * \return -1 on error, 1 on success
+ */
+int nlif_get_ifflags(const struct nlif_handle *h,
+ unsigned int index,
+ unsigned int *flags)
+{
+ unsigned int hash;
+ struct ifindex_node *this;
+
+ assert(h != NULL);
+ assert(flags != NULL);
+
+ if (index == 0) {
+ errno = ENOENT;
+ return -1;
+ }
+
+ hash = index & 0xF;
+ list_for_each_entry(this, &h->ifindex_hash[hash], head) {
+ if (this->index == index) {
+ *flags = this->flags;
+ return 1;
+ }
+ }
+ errno = ENOENT;
+ return -1;
+}
+
+/**
+ * nlif_open - initialize interface table
+ *
+ * Initialize rtnl interface and interface table
+ * Call this before any nlif_* function
+ *
+ * \return file descriptor to netlink socket
+ */
+struct nlif_handle *nlif_open(void)
+{
+ int i;
+ struct nlif_handle *h;
+
+ h = calloc(1, sizeof(struct nlif_handle));
+ if (h == NULL)
+ goto err;
+
+ for (i = 0; i < 16; i++)
+ INIT_LIST_HEAD(&h->ifindex_hash[i]);
+
+ h->ifadd_handler.nlmsg_type = RTM_NEWLINK;
+ h->ifadd_handler.handlefn = iftable_add;
+ h->ifadd_handler.arg = h;
+ h->ifdel_handler.nlmsg_type = RTM_DELLINK;
+ h->ifdel_handler.handlefn = iftable_del;
+ h->ifdel_handler.arg = h;
+
+ h->rtnl_handle = rtnl_open();
+ if (h->rtnl_handle == NULL)
+ goto err;
+
+ if (rtnl_handler_register(h->rtnl_handle, &h->ifadd_handler) < 0)
+ goto err_close;
+
+ if (rtnl_handler_register(h->rtnl_handle, &h->ifdel_handler) < 0)
+ goto err_unregister;
+
+ return h;
+
+err_unregister:
+ rtnl_handler_unregister(h->rtnl_handle, &h->ifadd_handler);
+err_close:
+ rtnl_close(h->rtnl_handle);
+ free(h);
+err:
+ return NULL;
+}
+
+/**
+ * nlif_close - free all resources associated with the interface table
+ *
+ * \param h pointer to nlif_handle created by nlif_open()
+ */
+void nlif_close(struct nlif_handle *h)
+{
+ int i;
+ struct ifindex_node *this, *tmp;
+
+ assert(h != NULL);
+
+ rtnl_handler_unregister(h->rtnl_handle, &h->ifadd_handler);
+ rtnl_handler_unregister(h->rtnl_handle, &h->ifdel_handler);
+ rtnl_close(h->rtnl_handle);
+
+ for (i = 0; i < 16; i++) {
+ list_for_each_entry_safe(this, tmp, &h->ifindex_hash[i], head) {
+ list_del(&this->head);
+ free(this);
+ }
+ }
+
+ free(h);
+ h = NULL; /* bugtrap */
+}
+
+/**
+ * nlif_catch - receive message from netlink and update interface table
+ *
+ * FIXME - elaborate a bit
+ *
+ * \param h pointer to nlif_handle created by nlif_open()
+ * \return 0 if OK
+ */
+int nlif_catch(struct nlif_handle *h)
+{
+ assert(h != NULL);
+
+ if (h->rtnl_handle)
+ return rtnl_receive(h->rtnl_handle);
+
+ return -1;
+}
+
+static int nlif_catch_multi(struct nlif_handle *h)
+{
+ assert(h != NULL);
+
+ if (h->rtnl_handle)
+ return rtnl_receive_multi(h->rtnl_handle);
+
+ return -1;
+}
+
+/**
+ * nlif_query - request a dump of interfaces available in the system
+ * \param h: pointer to a valid nlif_handler
+ */
+int nlif_query(struct nlif_handle *h)
+{
+ assert(h != NULL);
+
+ if (rtnl_dump_type(h->rtnl_handle, RTM_GETLINK) < 0)
+ return -1;
+
+ return nlif_catch_multi(h);
+}
+
+/**
+ * nlif_fd - get file descriptor for the netlink socket
+ *
+ * \param h pointer to nlif_handle created by nlif_open()
+ * \return The fd or -1 if there's an error
+ */
+int nlif_fd(struct nlif_handle *h)
+{
+ assert(h != NULL);
+
+ if (h->rtnl_handle)
+ return h->rtnl_handle->rtnl_fd;
+
+ return -1;
+}
+
+/**
+ * @}
+ */
--
2.35.8
