src/or/buffers.h

   1 /* Copyright (c) 2001 Matej Pfajfar.
   2  * Copyright (c) 2001-2004, Roger Dingledine.
   3  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   4  * Copyright (c) 2007-2016, The Tor Project, Inc. */
   5 /* See LICENSE for licensing information */
   6
   7 /**
   8  * \file buffers.h
   9  * \brief Header file for buffers.c.
  10  **/
  11
  12 #ifndef TOR_BUFFERS_H
  13 #define TOR_BUFFERS_H
  14
  15 #include "testsupport.h"
  16
  17 buf_t *buf_new(void);
  18 buf_t *buf_new_with_capacity(size_t size);
  19 size_t buf_get_default_chunk_size(const buf_t *buf);
  20 void buf_free(buf_t *buf);
  21 void buf_clear(buf_t *buf);
  22 buf_t *buf_copy(const buf_t *buf);
  23
  24 MOCK_DECL(size_t, buf_datalen, (const buf_t *buf));
  25 size_t buf_allocation(const buf_t *buf);
  26 size_t buf_slack(const buf_t *buf);
  27
  28 uint32_t buf_get_oldest_chunk_timestamp(const buf_t *buf, uint32_t now);
  29 size_t buf_get_total_allocation(void);
  30
  31 int read_to_buf(tor_socket_t s, size_t at_most, buf_t *buf, int *reached_eof,
  32                 int *socket_error);
  33 int read_to_buf_tls(tor_tls_t *tls, size_t at_most, buf_t *buf);
  34
  35 int flush_buf(tor_socket_t s, buf_t *buf, size_t sz, size_t *buf_flushlen);
  36 int flush_buf_tls(tor_tls_t *tls, buf_t *buf, size_t sz, size_t *buf_flushlen);
  37
  38 int write_to_buf(const char *string, size_t string_len, buf_t *buf);
  39 int write_to_buf_zlib(buf_t *buf, tor_zlib_state_t *state,
  40                       const char *data, size_t data_len, int done);
  41 int move_buf_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen);
  42 int fetch_from_buf(char *string, size_t string_len, buf_t *buf);
  43 int fetch_var_cell_from_buf(buf_t *buf, var_cell_t **out, int linkproto);
  44 int fetch_from_buf_http(buf_t *buf,
  45                         char **headers_out, size_t max_headerlen,
  46                         char **body_out, size_t *body_used, size_t max_bodylen,
  47                         int force_complete);
  48 socks_request_t *socks_request_new(void);
  49 void socks_request_free(socks_request_t *req);
  50 int fetch_from_buf_socks(buf_t *buf, socks_request_t *req,
  51                          int log_sockstype, int safe_socks);
  52 int fetch_from_buf_socks_client(buf_t *buf, int state, char **reason);
  53 int fetch_from_buf_line(buf_t *buf, char *data_out, size_t *data_len);
  54
  55 int peek_buf_has_control0_command(buf_t *buf);
  56
  57 int fetch_ext_or_command_from_buf(buf_t *buf, ext_or_cmd_t **out);
  58
  59 int buf_set_to_copy(buf_t **output,
  60                     const buf_t *input);
  61
  62 void assert_buf_ok(buf_t *buf);
  63
  64 #ifdef BUFFERS_PRIVATE
  65 STATIC int buf_find_string_offset(const buf_t *buf, const char *s, size_t n);
  66 STATIC void buf_pullup(buf_t *buf, size_t bytes);
  67 void buf_get_first_chunk_data(const buf_t *buf, const char **cp, size_t *sz);
  68 STATIC size_t preferred_chunk_size(size_t target);
  69
  70 #define DEBUG_CHUNK_ALLOC
  71 /** A single chunk on a buffer. */
  72 typedef struct chunk_t {
  73   struct chunk_t *next; /**< The next chunk on the buffer. */
  74   size_t datalen; /**< The number of bytes stored in this chunk */
  75   size_t memlen; /**< The number of usable bytes of storage in <b>mem</b>. */
  76 #ifdef DEBUG_CHUNK_ALLOC
  77   size_t DBG_alloc;
  78 #endif
  79   char *data; /**< A pointer to the first byte of data stored in <b>mem</b>. */
  80   uint32_t inserted_time; /**< Timestamp in truncated ms since epoch
  81                            * when this chunk was inserted. */
  82   char mem[FLEXIBLE_ARRAY_MEMBER]; /**< The actual memory used for storage in
  83                 * this chunk. */
  84 } chunk_t;
  85
  86 /** Magic value for buf_t.magic, to catch pointer errors. */
  87 #define BUFFER_MAGIC 0xB0FFF312u
  88 /** A resizeable buffer, optimized for reading and writing. */
  89 struct buf_t {
  90   uint32_t magic; /**< Magic cookie for debugging: Must be set to
  91                    *   BUFFER_MAGIC. */
  92   size_t datalen; /**< How many bytes is this buffer holding right now? */
  93   size_t default_chunk_size; /**< Don't allocate any chunks smaller than
  94                               * this for this buffer. */
  95   chunk_t *head; /**< First chunk in the list, or NULL for none. */
  96   chunk_t *tail; /**< Last chunk in the list, or NULL for none. */
  97 };
  98 #endif
  99
 100 #endif
 101