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) 2007-2013, 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 void buf_shrink(buf_t *buf);
  24 size_t buf_shrink_freelists(int free_all);
  25 void buf_dump_freelist_sizes(int severity);
  26
  27 size_t buf_datalen(const buf_t *buf);
  28 size_t buf_allocation(const buf_t *buf);
  29 size_t buf_slack(const buf_t *buf);
  30
  31 uint32_t buf_get_oldest_chunk_timestamp(const buf_t *buf, uint32_t now);
  32 size_t buf_get_total_allocation(void);
  33
  34 int read_to_buf(tor_socket_t s, size_t at_most, buf_t *buf, int *reached_eof,
  35                 int *socket_error);
  36 int read_to_buf_tls(tor_tls_t *tls, size_t at_most, buf_t *buf);
  37
  38 int flush_buf(tor_socket_t s, buf_t *buf, size_t sz, size_t *buf_flushlen);
  39 int flush_buf_tls(tor_tls_t *tls, buf_t *buf, size_t sz, size_t *buf_flushlen);
  40
  41 int write_to_buf(const char *string, size_t string_len, buf_t *buf);
  42 int write_to_buf_zlib(buf_t *buf, tor_zlib_state_t *state,
  43                       const char *data, size_t data_len, int done);
  44 int move_buf_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen);
  45 int fetch_from_buf(char *string, size_t string_len, buf_t *buf);
  46 int fetch_var_cell_from_buf(buf_t *buf, var_cell_t **out, int linkproto);
  47 int fetch_from_buf_http(buf_t *buf,
  48                         char **headers_out, size_t max_headerlen,
  49                         char **body_out, size_t *body_used, size_t max_bodylen,
  50                         int force_complete);
  51 socks_request_t *socks_request_new(void);
  52 void socks_request_free(socks_request_t *req);
  53 int fetch_from_buf_socks(buf_t *buf, socks_request_t *req,
  54                          int log_sockstype, int safe_socks);
  55 int fetch_from_buf_socks_client(buf_t *buf, int state, char **reason);
  56 int fetch_from_buf_line(buf_t *buf, char *data_out, size_t *data_len);
  57
  58 int peek_buf_has_control0_command(buf_t *buf);
  59
  60 int fetch_ext_or_command_from_buf(buf_t *buf, ext_or_cmd_t **out);
  61
  62 #ifdef USE_BUFFEREVENTS
  63 int fetch_var_cell_from_evbuffer(struct evbuffer *buf, var_cell_t **out,
  64                                  int linkproto);
  65 int fetch_from_evbuffer_socks(struct evbuffer *buf, socks_request_t *req,
  66                               int log_sockstype, int safe_socks);
  67 int fetch_from_evbuffer_socks_client(struct evbuffer *buf, int state,
  68                                      char **reason);
  69 int fetch_from_evbuffer_http(struct evbuffer *buf,
  70                         char **headers_out, size_t max_headerlen,
  71                         char **body_out, size_t *body_used, size_t max_bodylen,
  72                         int force_complete);
  73 int peek_evbuffer_has_control0_command(struct evbuffer *buf);
  74 int write_to_evbuffer_zlib(struct evbuffer *buf, tor_zlib_state_t *state,
  75                            const char *data, size_t data_len,
  76                            int done);
  77 int fetch_ext_or_command_from_evbuffer(struct evbuffer *buf,
  78                                        ext_or_cmd_t **out);
  79 #endif
  80
  81 #ifdef USE_BUFFEREVENTS
  82 #define generic_buffer_new() evbuffer_new()
  83 #define generic_buffer_len(b) evbuffer_get_length((b))
  84 #define generic_buffer_add(b,dat,len) evbuffer_add((b),(dat),(len))
  85 #define generic_buffer_get(b,buf,buflen) evbuffer_remove((b),(buf),(buflen))
  86 #define generic_buffer_clear(b) evbuffer_drain((b), evbuffer_get_length((b)))
  87 #define generic_buffer_free(b) evbuffer_free((b))
  88 #define generic_buffer_fetch_ext_or_cmd(b, out) \
  89   fetch_ext_or_command_from_evbuffer((b), (out))
  90 #else
  91 #define generic_buffer_new() buf_new()
  92 #define generic_buffer_len(b) buf_datalen((b))
  93 #define generic_buffer_add(b,dat,len) write_to_buf((dat),(len),(b))
  94 #define generic_buffer_get(b,buf,buflen) fetch_from_buf((buf),(buflen),(b))
  95 #define generic_buffer_clear(b) buf_clear((b))
  96 #define generic_buffer_free(b) buf_free((b))
  97 #define generic_buffer_fetch_ext_or_cmd(b, out) \
  98   fetch_ext_or_command_from_buf((b), (out))
  99 #endif
 100 int generic_buffer_set_to_copy(generic_buffer_t **output,
 101                                const generic_buffer_t *input);
 102
 103 void assert_buf_ok(buf_t *buf);
 104
 105 #ifdef BUFFERS_PRIVATE
 106 STATIC int buf_find_string_offset(const buf_t *buf, const char *s, size_t n);
 107 STATIC void buf_pullup(buf_t *buf, size_t bytes, int nulterminate);
 108 void buf_get_first_chunk_data(const buf_t *buf, const char **cp, size_t *sz);
 109
 110 #define DEBUG_CHUNK_ALLOC
 111 /** A single chunk on a buffer or in a freelist. */
 112 typedef struct chunk_t {
 113   struct chunk_t *next; /**< The next chunk on the buffer or freelist. */
 114   size_t datalen; /**< The number of bytes stored in this chunk */
 115   size_t memlen; /**< The number of usable bytes of storage in <b>mem</b>. */
 116 #ifdef DEBUG_CHUNK_ALLOC
 117   size_t DBG_alloc;
 118 #endif
 119   char *data; /**< A pointer to the first byte of data stored in <b>mem</b>. */
 120   uint32_t inserted_time; /**< Timestamp in truncated ms since epoch
 121                            * when this chunk was inserted. */
 122   char mem[FLEXIBLE_ARRAY_MEMBER]; /**< The actual memory used for storage in
 123                 * this chunk. */
 124 } chunk_t;
 125
 126 /** Magic value for buf_t.magic, to catch pointer errors. */
 127 #define BUFFER_MAGIC 0xB0FFF312u
 128 /** A resizeable buffer, optimized for reading and writing. */
 129 struct buf_t {
 130   uint32_t magic; /**< Magic cookie for debugging: Must be set to
 131                    *   BUFFER_MAGIC. */
 132   size_t datalen; /**< How many bytes is this buffer holding right now? */
 133   size_t default_chunk_size; /**< Don't allocate any chunks smaller than
 134                               * this for this buffer. */
 135   chunk_t *head; /**< First chunk in the list, or NULL for none. */
 136   chunk_t *tail; /**< Last chunk in the list, or NULL for none. */
 137 };
 138 #endif
 139
 140 #endif
 141