include/linux/netfilter_ipv4/listhelp.h

   1 #ifndef _LISTHELP_H
   2 #define _LISTHELP_H
   3 #include <linux/config.h>
   4 #include <linux/list.h>
   5
   6 /* Header to do more comprehensive job than linux/list.h; assume list
   7    is first entry in structure. */
   8
   9 /* Return pointer to first true entry, if any, or NULL.  A macro
  10    required to allow inlining of cmpfn. */
  11 #define LIST_FIND(head, cmpfn, type, args...)           \
  12 ({                                                      \
  13         const struct list_head *__i, *__j = NULL;       \
  14                                                         \
  15         ASSERT_READ_LOCK(head);                         \
  16         list_for_each(__i, (head))                      \
  17                 if (cmpfn((const type)__i , ## args)) { \
  18                         __j = __i;                      \
  19                         break;                          \
  20                 }                                       \
  21         (type)__j;                                      \
  22 })
  23
  24 #define LIST_FIND_W(head, cmpfn, type, args...)         \
  25 ({                                                      \
  26         const struct list_head *__i, *__j = NULL;       \
  27                                                         \
  28         ASSERT_WRITE_LOCK(head);                        \
  29         list_for_each(__i, (head))                      \
  30                 if (cmpfn((type)__i , ## args)) {       \
  31                         __j = __i;                      \
  32                         break;                          \
  33                 }                                       \
  34         (type)__j;                                      \
  35 })
  36
  37 /* Just like LIST_FIND but we search backwards */
  38 #define LIST_FIND_B(head, cmpfn, type, args...)         \
  39 ({                                                      \
  40         const struct list_head *__i, *__j = NULL;       \
  41                                                         \
  42         ASSERT_READ_LOCK(head);                         \
  43         list_for_each_prev(__i, (head))                 \
  44                 if (cmpfn((const type)__i , ## args)) { \
  45                         __j = __i;                      \
  46                         break;                          \
  47                 }                                       \
  48         (type)__j;                                      \
  49 })
  50
  51 static inline int
  52 __list_cmp_same(const void *p1, const void *p2) { return p1 == p2; }
  53
  54 /* Is this entry in the list? */
  55 static inline int
  56 list_inlist(struct list_head *head, const void *entry)
  57 {
  58         return LIST_FIND(head, __list_cmp_same, void *, entry) != NULL;
  59 }
  60
  61 /* Delete from list. */
  62 #ifdef CONFIG_NETFILTER_DEBUG
  63 #define LIST_DELETE(head, oldentry)                                     \
  64 do {                                                                    \
  65         ASSERT_WRITE_LOCK(head);                                        \
  66         if (!list_inlist(head, oldentry))                               \
  67                 printk("LIST_DELETE: %s:%u `%s'(%p) not in %s.\n",      \
  68                        __FILE__, __LINE__, #oldentry, oldentry, #head); \
  69         else list_del((struct list_head *)oldentry);                    \
  70 } while(0)
  71 #else
  72 #define LIST_DELETE(head, oldentry) list_del((struct list_head *)oldentry)
  73 #endif
  74
  75 /* Append. */
  76 static inline void
  77 list_append(struct list_head *head, void *new)
  78 {
  79         ASSERT_WRITE_LOCK(head);
  80         list_add((new), (head)->prev);
  81 }
  82
  83 /* Prepend. */
  84 static inline void
  85 list_prepend(struct list_head *head, void *new)
  86 {
  87         ASSERT_WRITE_LOCK(head);
  88         list_add(new, head);
  89 }
  90
  91 /* Insert according to ordering function; insert before first true. */
  92 #define LIST_INSERT(head, new, cmpfn)                           \
  93 do {                                                            \
  94         struct list_head *__i;                                  \
  95         ASSERT_WRITE_LOCK(head);                                \
  96         list_for_each(__i, (head))                              \
  97                 if ((new), (typeof (new))__i)                   \
  98                         break;                                  \
  99         list_add((struct list_head *)(new), __i->prev);         \
 100 } while(0)
 101
 102 /* If the field after the list_head is a nul-terminated string, you
 103    can use these functions. */
 104 static inline int __list_cmp_name(const void *i, const char *name)
 105 {
 106         return strcmp(name, i+sizeof(struct list_head)) == 0;
 107 }
 108
 109 /* Returns false if same name already in list, otherwise does insert. */
 110 static inline int
 111 list_named_insert(struct list_head *head, void *new)
 112 {
 113         if (LIST_FIND(head, __list_cmp_name, void *,
 114                       new + sizeof(struct list_head)))
 115                 return 0;
 116         list_prepend(head, new);
 117         return 1;
 118 }
 119
 120 /* Find this named element in the list. */
 121 #define list_named_find(head, name)                     \
 122 LIST_FIND(head, __list_cmp_name, void *, name)
 123
 124 #endif /*_LISTHELP_H*/