lib/ofpbuf.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef OFPBUF_H
  18 #define OFPBUF_H 1
  19
  20 #include <stddef.h>
  21 #include <stdint.h>
  22 #include "list.h"
  23 #include "util.h"
  24
  25 #ifdef  __cplusplus
  26 extern "C" {
  27 #endif
  28
  29 enum ofpbuf_source {
  30     OFPBUF_MALLOC,              /* Obtained via malloc(). */
  31     OFPBUF_STACK,               /* Un-movable stack space or static buffer. */
  32     OFPBUF_STUB                 /* Starts on stack, may expand into heap. */
  33 };
  34
  35 /* Buffer for holding arbitrary data.  An ofpbuf is automatically reallocated
  36  * as necessary if it grows too large for the available memory. */
  37 struct ofpbuf {
  38     void *base;                 /* First byte of allocated space. */
  39     size_t allocated;           /* Number of bytes allocated. */
  40     enum ofpbuf_source source;  /* Source of memory allocated as 'base'. */
  41
  42     void *data;                 /* First byte actually in use. */
  43     size_t size;                /* Number of bytes in use. */
  44
  45     void *l2;                   /* Link-level header. */
  46     void *l3;                   /* Network-level header. */
  47     void *l4;                   /* Transport-level header. */
  48     void *l7;                   /* Application data. */
  49
  50     struct list list_node;      /* Private list element for use by owner. */
  51     void *private_p;            /* Private pointer for use by owner. */
  52 };
  53
  54 /* Declares NAME as a SIZE-byte array aligned properly for storing any kind of
  55  * data.  For use with ofpbuf_use_stack(). */
  56 #define OFPBUF_STACK_BUFFER(NAME, SIZE) uint64_t NAME[DIV_ROUND_UP(SIZE, 8)]
  57
  58 void ofpbuf_use(struct ofpbuf *, void *, size_t);
  59 void ofpbuf_use_stack(struct ofpbuf *, void *, size_t);
  60 void ofpbuf_use_stub(struct ofpbuf *, void *, size_t);
  61 void ofpbuf_use_const(struct ofpbuf *, const void *, size_t);
  62
  63 void ofpbuf_init(struct ofpbuf *, size_t);
  64 void ofpbuf_uninit(struct ofpbuf *);
  65 void *ofpbuf_get_uninit_pointer(struct ofpbuf *);
  66 void ofpbuf_reinit(struct ofpbuf *, size_t);
  67
  68 struct ofpbuf *ofpbuf_new(size_t);
  69 struct ofpbuf *ofpbuf_new_with_headroom(size_t, size_t headroom);
  70 struct ofpbuf *ofpbuf_clone(const struct ofpbuf *);
  71 struct ofpbuf *ofpbuf_clone_with_headroom(const struct ofpbuf *,
  72                                           size_t headroom);
  73 struct ofpbuf *ofpbuf_clone_data(const void *, size_t);
  74 struct ofpbuf *ofpbuf_clone_data_with_headroom(const void *, size_t,
  75                                                size_t headroom);
  76 void ofpbuf_delete(struct ofpbuf *);
  77
  78 void *ofpbuf_at(const struct ofpbuf *, size_t offset, size_t size);
  79 void *ofpbuf_at_assert(const struct ofpbuf *, size_t offset, size_t size);
  80 void *ofpbuf_tail(const struct ofpbuf *);
  81 void *ofpbuf_end(const struct ofpbuf *);
  82
  83 void *ofpbuf_put_uninit(struct ofpbuf *, size_t);
  84 void *ofpbuf_put_zeros(struct ofpbuf *, size_t);
  85 void *ofpbuf_put(struct ofpbuf *, const void *, size_t);
  86 char *ofpbuf_put_hex(struct ofpbuf *, const char *s, size_t *n);
  87 void ofpbuf_reserve(struct ofpbuf *, size_t);
  88 void *ofpbuf_push_uninit(struct ofpbuf *b, size_t);
  89 void *ofpbuf_push_zeros(struct ofpbuf *, size_t);
  90 void *ofpbuf_push(struct ofpbuf *b, const void *, size_t);
  91
  92 size_t ofpbuf_headroom(const struct ofpbuf *);
  93 size_t ofpbuf_tailroom(const struct ofpbuf *);
  94 void ofpbuf_prealloc_headroom(struct ofpbuf *, size_t);
  95 void ofpbuf_prealloc_tailroom(struct ofpbuf *, size_t);
  96 void ofpbuf_trim(struct ofpbuf *);
  97 void ofpbuf_padto(struct ofpbuf *, size_t);
  98
  99 void ofpbuf_clear(struct ofpbuf *);
 100 void *ofpbuf_pull(struct ofpbuf *, size_t);
 101 void *ofpbuf_try_pull(struct ofpbuf *, size_t);
 102
 103 void *ofpbuf_steal_data(struct ofpbuf *);
 104
 105 char *ofpbuf_to_string(const struct ofpbuf *, size_t maxbytes);
 106
 107 static inline struct ofpbuf *ofpbuf_from_list(const struct list *list)
 108 {
 109     return CONTAINER_OF(list, struct ofpbuf, list_node);
 110 }
 111 void ofpbuf_list_delete(struct list *);
 112
 113 #ifdef  __cplusplus
 114 }
 115 #endif
 116
 117 #endif /* ofpbuf.h */