Move buffers.c out of lib/containers to resolve a circularity.

4 files changed, 0 insertions, 1052 deletions

diff --git a/src/lib/container/.may_include b/src/lib/container/.may_include
index 90de5eda40..76e5843728 100644
--- a/src/lib/container/.may_include
+++ b/src/lib/container/.may_include
@@ -11,8 +11,5 @@ lib/testsupport/testsupport.h
 lib/intmath/*.h
 lib/log/*.h
 
-# XXXX I am unsure about this one. It's only here for buffers.c
-lib/time/*.h
-
 ht.h
 siphash.h
diff --git a/src/lib/container/buffers.c b/src/lib/container/buffers.c
deleted file mode 100644
index 87d782d7ef..0000000000
--- a/src/lib/container/buffers.c
+++ /dev/null
@@ -1,925 +0,0 @@
-/* Copyright (c) 2001 Matej Pfajfar.
- * Copyright (c) 2001-2004, Roger Dingledine.
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2018, The Tor Project, Inc. */
-/* See LICENSE for licensing information */
-
-/**
- * \file buffers.c
- * \brief Implements a generic buffer interface.
- *
- * A buf_t is a (fairly) opaque byte-oriented FIFO that can read to or flush
- * from memory, sockets, file descriptors, TLS connections, or another buf_t.
- * Buffers are implemented as linked lists of memory chunks.
- *
- * All socket-backed and TLS-based connection_t objects have a pair of
- * buffers: one for incoming data, and one for outcoming data.  These are fed
- * and drained from functions in connection.c, trigged by events that are
- * monitored in main.c.
- *
- * This module only handles the buffer implementation itself. To use a buffer
- * with the network, a compressor, or a TLS connection, see the other buffer_*
- * modules.
- **/
-
-#define BUFFERS_PRIVATE
-#include "orconfig.h"
-#include <stddef.h>
-#include "lib/container/buffers.h"
-#include "lib/cc/torint.h"
-#include "lib/log/log.h"
-#include "lib/log/util_bug.h"
-#include "lib/ctime/di_ops.h"
-#include "lib/malloc/malloc.h"
-#include "lib/string/printf.h"
-#include "lib/time/compat_time.h"
-
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
-#include <stdlib.h>
-#include <string.h>
-
-//#define PARANOIA
-
-#ifdef PARANOIA
-/** Helper: If PARANOIA is defined, assert that the buffer in local variable
- * <b>buf</b> is well-formed. */
-#define check() STMT_BEGIN buf_assert_ok(buf); STMT_END
-#else
-#define check() STMT_NIL
-#endif /* defined(PARANOIA) */
-
-/* Implementation notes:
- *
- * After flirting with memmove, and dallying with ring-buffers, we're finally
- * getting up to speed with the 1970s and implementing buffers as a linked
- * list of small chunks.  Each buffer has such a list; data is removed from
- * the head of the list, and added at the tail.  The list is singly linked,
- * and the buffer keeps a pointer to the head and the tail.
- *
- * Every chunk, except the tail, contains at least one byte of data.  Data in
- * each chunk is contiguous.
- *
- * When you need to treat the first N characters on a buffer as a contiguous
- * string, use the buf_pullup function to make them so.  Don't do this more
- * than necessary.
- *
- * The major free Unix kernels have handled buffers like this since, like,
- * forever.
- */
-
-/* Chunk manipulation functions */
-
-#define CHUNK_HEADER_LEN offsetof(chunk_t, mem[0])
-
-/* We leave this many NUL bytes at the end of the buffer. */
-#ifdef DISABLE_MEMORY_SENTINELS
-#define SENTINEL_LEN 0
-#else
-#define SENTINEL_LEN 4
-#endif
-
-/* Header size plus NUL bytes at the end */
-#define CHUNK_OVERHEAD (CHUNK_HEADER_LEN + SENTINEL_LEN)
-
-/** Return the number of bytes needed to allocate a chunk to hold
- * <b>memlen</b> bytes. */
-#define CHUNK_ALLOC_SIZE(memlen) (CHUNK_OVERHEAD + (memlen))
-/** Return the number of usable bytes in a chunk allocated with
- * malloc(<b>memlen</b>). */
-#define CHUNK_SIZE_WITH_ALLOC(memlen) ((memlen) - CHUNK_OVERHEAD)
-
-#define DEBUG_SENTINEL
-
-#if defined(DEBUG_SENTINEL) && !defined(DISABLE_MEMORY_SENTINELS)
-#define DBG_S(s) s
-#else
-#define DBG_S(s) (void)0
-#endif
-
-#ifdef DISABLE_MEMORY_SENTINELS
-#define CHUNK_SET_SENTINEL(chunk, alloclen) STMT_NIL
-#else
-#define CHUNK_SET_SENTINEL(chunk, alloclen) do {                        \
-    uint8_t *a = (uint8_t*) &(chunk)->mem[(chunk)->memlen];             \
-    DBG_S(uint8_t *b = &((uint8_t*)(chunk))[(alloclen)-SENTINEL_LEN]);  \
-    DBG_S(tor_assert(a == b));                                          \
-    memset(a,0,SENTINEL_LEN);                                           \
-  } while (0)
-#endif /* defined(DISABLE_MEMORY_SENTINELS) */
-
-/** Move all bytes stored in <b>chunk</b> to the front of <b>chunk</b>->mem,
- * to free up space at the end. */
-static inline void
-chunk_repack(chunk_t *chunk)
-{
-  if (chunk->datalen && chunk->data != &chunk->mem[0]) {
-    memmove(chunk->mem, chunk->data, chunk->datalen);
-  }
-  chunk->data = &chunk->mem[0];
-}
-
-/** Keep track of total size of allocated chunks for consistency asserts */
-static size_t total_bytes_allocated_in_chunks = 0;
-static void
-buf_chunk_free_unchecked(chunk_t *chunk)
-{
-  if (!chunk)
-    return;
-#ifdef DEBUG_CHUNK_ALLOC
-  tor_assert(CHUNK_ALLOC_SIZE(chunk->memlen) == chunk->DBG_alloc);
-#endif
-  tor_assert(total_bytes_allocated_in_chunks >=
-             CHUNK_ALLOC_SIZE(chunk->memlen));
-  total_bytes_allocated_in_chunks -= CHUNK_ALLOC_SIZE(chunk->memlen);
-  tor_free(chunk);
-}
-static inline chunk_t *
-chunk_new_with_alloc_size(size_t alloc)
-{
-  chunk_t *ch;
-  ch = tor_malloc(alloc);
-  ch->next = NULL;
-  ch->datalen = 0;
-#ifdef DEBUG_CHUNK_ALLOC
-  ch->DBG_alloc = alloc;
-#endif
-  ch->memlen = CHUNK_SIZE_WITH_ALLOC(alloc);
-  total_bytes_allocated_in_chunks += alloc;
-  ch->data = &ch->mem[0];
-  CHUNK_SET_SENTINEL(ch, alloc);
-  return ch;
-}
-
-/** Expand <b>chunk</b> until it can hold <b>sz</b> bytes, and return a
- * new pointer to <b>chunk</b>.  Old pointers are no longer valid. */
-static inline chunk_t *
-chunk_grow(chunk_t *chunk, size_t sz)
-{
-  off_t offset;
-  const size_t memlen_orig = chunk->memlen;
-  const size_t orig_alloc = CHUNK_ALLOC_SIZE(memlen_orig);
-  const size_t new_alloc = CHUNK_ALLOC_SIZE(sz);
-  tor_assert(sz > chunk->memlen);
-  offset = chunk->data - chunk->mem;
-  chunk = tor_realloc(chunk, new_alloc);
-  chunk->memlen = sz;
-  chunk->data = chunk->mem + offset;
-#ifdef DEBUG_CHUNK_ALLOC
-  tor_assert(chunk->DBG_alloc == orig_alloc);
-  chunk->DBG_alloc = new_alloc;
-#endif
-  total_bytes_allocated_in_chunks += new_alloc - orig_alloc;
-  CHUNK_SET_SENTINEL(chunk, new_alloc);
-  return chunk;
-}
-
-/** Every chunk should take up at least this many bytes. */
-#define MIN_CHUNK_ALLOC 256
-/** No chunk should take up more than this many bytes. */
-#define MAX_CHUNK_ALLOC 65536
-
-/** Return the allocation size we'd like to use to hold <b>target</b>
- * bytes. */
-size_t
-buf_preferred_chunk_size(size_t target)
-{
-  tor_assert(target <= SIZE_T_CEILING - CHUNK_OVERHEAD);
-  if (CHUNK_ALLOC_SIZE(target) >= MAX_CHUNK_ALLOC)
-    return CHUNK_ALLOC_SIZE(target);
-  size_t sz = MIN_CHUNK_ALLOC;
-  while (CHUNK_SIZE_WITH_ALLOC(sz) < target) {
-    sz <<= 1;
-  }
-  return sz;
-}
-
-/** Collapse data from the first N chunks from <b>buf</b> into buf->head,
- * growing it as necessary, until buf->head has the first <b>bytes</b> bytes
- * of data from the buffer, or until buf->head has all the data in <b>buf</b>.
- *
- * Set *<b>head_out</b> to point to the first byte of available data, and
- * *<b>len_out</b> to the number of bytes of data available at
- * *<b>head_out</b>. Note that *<b>len_out</b> may be more or less than
- * <b>bytes</b>, depending on the number of bytes available.
- */
-void
-buf_pullup(buf_t *buf, size_t bytes, const char **head_out, size_t *len_out)
-{
-  chunk_t *dest, *src;
-  size_t capacity;
-  if (!buf->head) {
-    *head_out = NULL;
-    *len_out = 0;
-    return;
-  }
-
-  check();
-  if (buf->datalen < bytes)
-    bytes = buf->datalen;
-
-  capacity = bytes;
-  if (buf->head->datalen >= bytes) {
-    *head_out = buf->head->data;
-    *len_out = buf->head->datalen;
-    return;
-  }
-
-  if (buf->head->memlen >= capacity) {
-    /* We don't need to grow the first chunk, but we might need to repack it.*/
-    size_t needed = capacity - buf->head->datalen;
-    if (CHUNK_REMAINING_CAPACITY(buf->head) < needed)
-      chunk_repack(buf->head);
-    tor_assert(CHUNK_REMAINING_CAPACITY(buf->head) >= needed);
-  } else {
-    chunk_t *newhead;
-    size_t newsize;
-    /* We need to grow the chunk. */
-    chunk_repack(buf->head);
-    newsize = CHUNK_SIZE_WITH_ALLOC(buf_preferred_chunk_size(capacity));
-    newhead = chunk_grow(buf->head, newsize);
-    tor_assert(newhead->memlen >= capacity);
-    if (newhead != buf->head) {
-      if (buf->tail == buf->head)
-        buf->tail = newhead;
-      buf->head = newhead;
-    }
-  }
-
-  dest = buf->head;
-  while (dest->datalen < bytes) {
-    size_t n = bytes - dest->datalen;
-    src = dest->next;
-    tor_assert(src);
-    if (n >= src->datalen) {
-      memcpy(CHUNK_WRITE_PTR(dest), src->data, src->datalen);
-      dest->datalen += src->datalen;
-      dest->next = src->next;
-      if (buf->tail == src)
-        buf->tail = dest;
-      buf_chunk_free_unchecked(src);
-    } else {
-      memcpy(CHUNK_WRITE_PTR(dest), src->data, n);
-      dest->datalen += n;
-      src->data += n;
-      src->datalen -= n;
-      tor_assert(dest->datalen == bytes);
-    }
-  }
-
-  check();
-  *head_out = buf->head->data;
-  *len_out = buf->head->datalen;
-}
-
-#ifdef TOR_UNIT_TESTS
-/* Write sz bytes from cp into a newly allocated buffer buf.
- * Returns NULL when passed a NULL cp or zero sz.
- * Asserts on failure: only for use in unit tests.
- * buf must be freed using buf_free(). */
-buf_t *
-buf_new_with_data(const char *cp, size_t sz)
-{
-  /* Validate arguments */
-  if (!cp || sz <= 0) {
-    return NULL;
-  }
-
-  tor_assert(sz < SSIZE_T_CEILING);
-
-  /* Allocate a buffer */
-  buf_t *buf = buf_new_with_capacity(sz);
-  tor_assert(buf);
-  buf_assert_ok(buf);
-  tor_assert(!buf->head);
-
-  /* Allocate a chunk that is sz bytes long */
-  buf->head = chunk_new_with_alloc_size(CHUNK_ALLOC_SIZE(sz));
-  buf->tail = buf->head;
-  tor_assert(buf->head);
-  buf_assert_ok(buf);
-  tor_assert(buf_allocation(buf) >= sz);
-
-  /* Copy the data and size the buffers */
-  tor_assert(sz <= buf_slack(buf));
-  tor_assert(sz <= CHUNK_REMAINING_CAPACITY(buf->head));
-  memcpy(&buf->head->mem[0], cp, sz);
-  buf->datalen = sz;
-  buf->head->datalen = sz;
-  buf->head->data = &buf->head->mem[0];
-  buf_assert_ok(buf);
-
-  /* Make sure everything is large enough */
-  tor_assert(buf_allocation(buf) >= sz);
-  tor_assert(buf_allocation(buf) >= buf_datalen(buf) + buf_slack(buf));
-  /* Does the buffer implementation allocate more than the requested size?
-   * (for example, by rounding up). If so, these checks will fail. */
-  tor_assert(buf_datalen(buf) == sz);
-  tor_assert(buf_slack(buf) == 0);
-
-  return buf;
-}
-#endif /* defined(TOR_UNIT_TESTS) */
-
-/** Remove the first <b>n</b> bytes from buf. */
-void
-buf_drain(buf_t *buf, size_t n)
-{
-  tor_assert(buf->datalen >= n);
-  while (n) {
-    tor_assert(buf->head);
-    if (buf->head->datalen > n) {
-      buf->head->datalen -= n;
-      buf->head->data += n;
-      buf->datalen -= n;
-      return;
-    } else {
-      chunk_t *victim = buf->head;
-      n -= victim->datalen;
-      buf->datalen -= victim->datalen;
-      buf->head = victim->next;
-      if (buf->tail == victim)
-        buf->tail = NULL;
-      buf_chunk_free_unchecked(victim);
-    }
-  }
-  check();
-}
-
-/** Create and return a new buf with default chunk capacity <b>size</b>.
- */
-buf_t *
-buf_new_with_capacity(size_t size)
-{
-  buf_t *b = buf_new();
-  b->default_chunk_size = buf_preferred_chunk_size(size);
-  return b;
-}
-
-/** Allocate and return a new buffer with default capacity. */
-buf_t *
-buf_new(void)
-{
-  buf_t *buf = tor_malloc_zero(sizeof(buf_t));
-  buf->magic = BUFFER_MAGIC;
-  buf->default_chunk_size = 4096;
-  return buf;
-}
-
-size_t
-buf_get_default_chunk_size(const buf_t *buf)
-{
-  return buf->default_chunk_size;
-}
-
-/** Remove all data from <b>buf</b>. */
-void
-buf_clear(buf_t *buf)
-{
-  chunk_t *chunk, *next;
-  buf->datalen = 0;
-  for (chunk = buf->head; chunk; chunk = next) {
-    next = chunk->next;
-    buf_chunk_free_unchecked(chunk);
-  }
-  buf->head = buf->tail = NULL;
-}
-
-/** Return the number of bytes stored in <b>buf</b> */
-MOCK_IMPL(size_t,
-buf_datalen, (const buf_t *buf))
-{
-  return buf->datalen;
-}
-
-/** Return the total length of all chunks used in <b>buf</b>. */
-size_t
-buf_allocation(const buf_t *buf)
-{
-  size_t total = 0;
-  const chunk_t *chunk;
-  for (chunk = buf->head; chunk; chunk = chunk->next) {
-    total += CHUNK_ALLOC_SIZE(chunk->memlen);
-  }
-  return total;
-}
-
-/** Return the number of bytes that can be added to <b>buf</b> without
- * performing any additional allocation. */
-size_t
-buf_slack(const buf_t *buf)
-{
-  if (!buf->tail)
-    return 0;
-  else
-    return CHUNK_REMAINING_CAPACITY(buf->tail);
-}
-
-/** Release storage held by <b>buf</b>. */
-void
-buf_free_(buf_t *buf)
-{
-  if (!buf)
-    return;
-
-  buf_clear(buf);
-  buf->magic = 0xdeadbeef;
-  tor_free(buf);
-}
-
-/** Return a new copy of <b>in_chunk</b> */
-static chunk_t *
-chunk_copy(const chunk_t *in_chunk)
-{
-  chunk_t *newch = tor_memdup(in_chunk, CHUNK_ALLOC_SIZE(in_chunk->memlen));
-  total_bytes_allocated_in_chunks += CHUNK_ALLOC_SIZE(in_chunk->memlen);
-#ifdef DEBUG_CHUNK_ALLOC
-  newch->DBG_alloc = CHUNK_ALLOC_SIZE(in_chunk->memlen);
-#endif
-  newch->next = NULL;
-  if (in_chunk->data) {
-    off_t offset = in_chunk->data - in_chunk->mem;
-    newch->data = newch->mem + offset;
-  }
-  return newch;
-}
-
-/** Return a new copy of <b>buf</b> */
-buf_t *
-buf_copy(const buf_t *buf)
-{
-  chunk_t *ch;
-  buf_t *out = buf_new();
-  out->default_chunk_size = buf->default_chunk_size;
-  for (ch = buf->head; ch; ch = ch->next) {
-    chunk_t *newch = chunk_copy(ch);
-    if (out->tail) {
-      out->tail->next = newch;
-      out->tail = newch;
-    } else {
-      out->head = out->tail = newch;
-    }
-  }
-  out->datalen = buf->datalen;
-  return out;
-}
-
-/** Append a new chunk with enough capacity to hold <b>capacity</b> bytes to
- * the tail of <b>buf</b>.  If <b>capped</b>, don't allocate a chunk bigger
- * than MAX_CHUNK_ALLOC. */
-chunk_t *
-buf_add_chunk_with_capacity(buf_t *buf, size_t capacity, int capped)
-{
-  chunk_t *chunk;
-
-  if (CHUNK_ALLOC_SIZE(capacity) < buf->default_chunk_size) {
-    chunk = chunk_new_with_alloc_size(buf->default_chunk_size);
-  } else if (capped && CHUNK_ALLOC_SIZE(capacity) > MAX_CHUNK_ALLOC) {
-    chunk = chunk_new_with_alloc_size(MAX_CHUNK_ALLOC);
-  } else {
-    chunk = chunk_new_with_alloc_size(buf_preferred_chunk_size(capacity));
-  }
-
-  chunk->inserted_time = monotime_coarse_get_stamp();
-
-  if (buf->tail) {
-    tor_assert(buf->head);
-    buf->tail->next = chunk;
-    buf->tail = chunk;
-  } else {
-    tor_assert(!buf->head);
-    buf->head = buf->tail = chunk;
-  }
-  check();
-  return chunk;
-}
-
-/** Return the age of the oldest chunk in the buffer <b>buf</b>, in
- * timestamp units.  Requires the current monotonic timestamp as its
- * input <b>now</b>.
- */
-uint32_t
-buf_get_oldest_chunk_timestamp(const buf_t *buf, uint32_t now)
-{
-  if (buf->head) {
-    return now - buf->head->inserted_time;
-  } else {
-    return 0;
-  }
-}
-
-size_t
-buf_get_total_allocation(void)
-{
-  return total_bytes_allocated_in_chunks;
-}
-
-/** Append <b>string_len</b> bytes from <b>string</b> to the end of
- * <b>buf</b>.
- *
- * Return the new length of the buffer on success, -1 on failure.
- */
-int
-buf_add(buf_t *buf, const char *string, size_t string_len)
-{
-  if (!string_len)
-    return (int)buf->datalen;
-  check();
-
-  if (BUG(buf->datalen >= INT_MAX))
-    return -1;
-  if (BUG(buf->datalen >= INT_MAX - string_len))
-    return -1;
-
-  while (string_len) {
-    size_t copy;
-    if (!buf->tail || !CHUNK_REMAINING_CAPACITY(buf->tail))
-      buf_add_chunk_with_capacity(buf, string_len, 1);
-
-    copy = CHUNK_REMAINING_CAPACITY(buf->tail);
-    if (copy > string_len)
-      copy = string_len;
-    memcpy(CHUNK_WRITE_PTR(buf->tail), string, copy);
-    string_len -= copy;
-    string += copy;
-    buf->datalen += copy;
-    buf->tail->datalen += copy;
-  }
-
-  check();
-  tor_assert(buf->datalen < INT_MAX);
-  return (int)buf->datalen;
-}
-
-/** Add a nul-terminated <b>string</b> to <b>buf</b>, not including the
- * terminating NUL. */
-void
-buf_add_string(buf_t *buf, const char *string)
-{
-  buf_add(buf, string, strlen(string));
-}
-
-/** As tor_snprintf, but write the results into a buf_t */
-void
-buf_add_printf(buf_t *buf, const char *format, ...)
-{
-  va_list ap;
-  va_start(ap,format);
-  buf_add_vprintf(buf, format, ap);
-  va_end(ap);
-}
-
-/** As tor_vsnprintf, but write the results into a buf_t. */
-void
-buf_add_vprintf(buf_t *buf, const char *format, va_list args)
-{
-  /* XXXX Faster implementations are easy enough, but let's optimize later */
-  char *tmp;
-  tor_vasprintf(&tmp, format, args);
-  buf_add(buf, tmp, strlen(tmp));
-  tor_free(tmp);
-}
-
-/** Return a heap-allocated string containing the contents of <b>buf</b>, plus
- * a NUL byte. If <b>sz_out</b> is provided, set *<b>sz_out</b> to the length
- * of the returned string, not including the terminating NUL. */
-char *
-buf_extract(buf_t *buf, size_t *sz_out)
-{
-  tor_assert(buf);
-
-  size_t sz = buf_datalen(buf);
-  char *result;
-  result = tor_malloc(sz+1);
-  buf_peek(buf, result, sz);
-  result[sz] = 0;
-  if (sz_out)
-    *sz_out = sz;
-  return result;
-}
-
-/** Helper: copy the first <b>string_len</b> bytes from <b>buf</b>
- * onto <b>string</b>.
- */
-void
-buf_peek(const buf_t *buf, char *string, size_t string_len)
-{
-  chunk_t *chunk;
-
-  tor_assert(string);
-  /* make sure we don't ask for too much */
-  tor_assert(string_len <= buf->datalen);
-  /* buf_assert_ok(buf); */
-
-  chunk = buf->head;
-  while (string_len) {
-    size_t copy = string_len;
-    tor_assert(chunk);
-    if (chunk->datalen < copy)
-      copy = chunk->datalen;
-    memcpy(string, chunk->data, copy);
-    string_len -= copy;
-    string += copy;
-    chunk = chunk->next;
-  }
-}
-
-/** Remove <b>string_len</b> bytes from the front of <b>buf</b>, and store
- * them into <b>string</b>.  Return the new buffer size.  <b>string_len</b>
- * must be \<= the number of bytes on the buffer.
- */
-int
-buf_get_bytes(buf_t *buf, char *string, size_t string_len)
-{
-  /* There must be string_len bytes in buf; write them onto string,
-   * then memmove buf back (that is, remove them from buf).
-   *
-   * Return the number of bytes still on the buffer. */
-
-  check();
-  buf_peek(buf, string, string_len);
-  buf_drain(buf, string_len);
-  check();
-  tor_assert(buf->datalen < INT_MAX);
-  return (int)buf->datalen;
-}
-
-/** Move up to *<b>buf_flushlen</b> bytes from <b>buf_in</b> to
- * <b>buf_out</b>, and modify *<b>buf_flushlen</b> appropriately.
- * Return the number of bytes actually copied.
- */
-int
-buf_move_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen)
-{
-  /* We can do way better here, but this doesn't turn up in any profiles. */
-  char b[4096];
-  size_t cp, len;
-
-  if (BUG(buf_out->datalen >= INT_MAX))
-    return -1;
-  if (BUG(buf_out->datalen >= INT_MAX - *buf_flushlen))
-    return -1;
-
-  len = *buf_flushlen;
-  if (len > buf_in->datalen)
-    len = buf_in->datalen;
-
-  cp = len; /* Remember the number of bytes we intend to copy. */
-  tor_assert(cp < INT_MAX);
-  while (len) {
-    /* This isn't the most efficient implementation one could imagine, since
-     * it does two copies instead of 1, but I kinda doubt that this will be
-     * critical path. */
-    size_t n = len > sizeof(b) ? sizeof(b) : len;
-    buf_get_bytes(buf_in, b, n);
-    buf_add(buf_out, b, n);
-    len -= n;
-  }
-  *buf_flushlen -= cp;
-  return (int)cp;
-}
-
-/** Moves all data from <b>buf_in</b> to <b>buf_out</b>, without copying.
- */
-void
-buf_move_all(buf_t *buf_out, buf_t *buf_in)
-{
-  tor_assert(buf_out);
-  if (!buf_in)
-    return;
-
-  if (buf_out->head == NULL) {
-    buf_out->head = buf_in->head;
-    buf_out->tail = buf_in->tail;
-  } else {
-    buf_out->tail->next = buf_in->head;
-    buf_out->tail = buf_in->tail;
-  }
-
-  buf_out->datalen += buf_in->datalen;
-  buf_in->head = buf_in->tail = NULL;
-  buf_in->datalen = 0;
-}
-
-/** Internal structure: represents a position in a buffer. */
-typedef struct buf_pos_t {
-  const chunk_t *chunk; /**< Which chunk are we pointing to? */
-  int pos;/**< Which character inside the chunk's data are we pointing to? */
-  size_t chunk_pos; /**< Total length of all previous chunks. */
-} buf_pos_t;
-
-/** Initialize <b>out</b> to point to the first character of <b>buf</b>.*/
-static void
-buf_pos_init(const buf_t *buf, buf_pos_t *out)
-{
-  out->chunk = buf->head;
-  out->pos = 0;
-  out->chunk_pos = 0;
-}
-
-/** Advance <b>out</b> to the first appearance of <b>ch</b> at the current
- * position of <b>out</b>, or later.  Return -1 if no instances are found;
- * otherwise returns the absolute position of the character. */
-static off_t
-buf_find_pos_of_char(char ch, buf_pos_t *out)
-{
-  const chunk_t *chunk;
-  int pos;
-  tor_assert(out);
-  if (out->chunk) {
-    if (out->chunk->datalen) {
-      tor_assert(out->pos < (off_t)out->chunk->datalen);
-    } else {
-      tor_assert(out->pos == 0);
-    }
-  }
-  pos = out->pos;
-  for (chunk = out->chunk; chunk; chunk = chunk->next) {
-    char *cp = memchr(chunk->data+pos, ch, chunk->datalen - pos);
-    if (cp) {
-      out->chunk = chunk;
-      tor_assert(cp - chunk->data < INT_MAX);
-      out->pos = (int)(cp - chunk->data);
-      return out->chunk_pos + out->pos;
-    } else {
-      out->chunk_pos += chunk->datalen;
-      pos = 0;
-    }
-  }
-  return -1;
-}
-
-/** Advance <b>pos</b> by a single character, if there are any more characters
- * in the buffer.  Returns 0 on success, -1 on failure. */
-static inline int
-buf_pos_inc(buf_pos_t *pos)
-{
-  ++pos->pos;
-  if (pos->pos == (off_t)pos->chunk->datalen) {
-    if (!pos->chunk->next)
-      return -1;
-    pos->chunk_pos += pos->chunk->datalen;
-    pos->chunk = pos->chunk->next;
-    pos->pos = 0;
-  }
-  return 0;
-}
-
-/** Return true iff the <b>n</b>-character string in <b>s</b> appears
- * (verbatim) at <b>pos</b>. */
-static int
-buf_matches_at_pos(const buf_pos_t *pos, const char *s, size_t n)
-{
-  buf_pos_t p;
-  if (!n)
-    return 1;
-
-  memcpy(&p, pos, sizeof(p));
-
-  while (1) {
-    char ch = p.chunk->data[p.pos];
-    if (ch != *s)
-      return 0;
-    ++s;
-    /* If we're out of characters that don't match, we match.  Check this
-     * _before_ we test incrementing pos, in case we're at the end of the
-     * string. */
-    if (--n == 0)
-      return 1;
-    if (buf_pos_inc(&p)<0)
-      return 0;
-  }
-}
-
-/** Return the first position in <b>buf</b> at which the <b>n</b>-character
- * string <b>s</b> occurs, or -1 if it does not occur. */
-int
-buf_find_string_offset(const buf_t *buf, const char *s, size_t n)
-{
-  buf_pos_t pos;
-  buf_pos_init(buf, &pos);
-  while (buf_find_pos_of_char(*s, &pos) >= 0) {
-    if (buf_matches_at_pos(&pos, s, n)) {
-      tor_assert(pos.chunk_pos + pos.pos < INT_MAX);
-      return (int)(pos.chunk_pos + pos.pos);
-    } else {
-      if (buf_pos_inc(&pos)<0)
-        return -1;
-    }
-  }
-  return -1;
-}
-
-/** Return 1 iff <b>buf</b> starts with <b>cmd</b>. <b>cmd</b> must be a null
- * terminated string, of no more than PEEK_BUF_STARTSWITH_MAX bytes. */
-int
-buf_peek_startswith(const buf_t *buf, const char *cmd)
-{
-  char tmp[PEEK_BUF_STARTSWITH_MAX];
-  size_t clen = strlen(cmd);
-  if (clen == 0)
-    return 1;
-  if (BUG(clen > sizeof(tmp)))
-    return 0;
-  if (buf->datalen < clen)
-    return 0;
-  buf_peek(buf, tmp, clen);
-  return fast_memeq(tmp, cmd, clen);
-}
-
-/** Return the index within <b>buf</b> at which <b>ch</b> first appears,
- * or -1 if <b>ch</b> does not appear on buf. */
-static off_t
-buf_find_offset_of_char(buf_t *buf, char ch)
-{
-  chunk_t *chunk;
-  off_t offset = 0;
-  for (chunk = buf->head; chunk; chunk = chunk->next) {
-    char *cp = memchr(chunk->data, ch, chunk->datalen);
-    if (cp)
-      return offset + (cp - chunk->data);
-    else
-      offset += chunk->datalen;
-  }
-  return -1;
-}
-
-/** Try to read a single LF-terminated line from <b>buf</b>, and write it
- * (including the LF), NUL-terminated, into the *<b>data_len</b> byte buffer
- * at <b>data_out</b>.  Set *<b>data_len</b> to the number of bytes in the
- * line, not counting the terminating NUL.  Return 1 if we read a whole line,
- * return 0 if we don't have a whole line yet, and return -1 if the line
- * length exceeds *<b>data_len</b>.
- */
-int
-buf_get_line(buf_t *buf, char *data_out, size_t *data_len)
-{
-  size_t sz;
-  off_t offset;
-
-  if (!buf->head)
-    return 0;
-
-  offset = buf_find_offset_of_char(buf, '\n');
-  if (offset < 0)
-    return 0;
-  sz = (size_t) offset;
-  if (sz+2 > *data_len) {
-    *data_len = sz + 2;
-    return -1;
-  }
-  buf_get_bytes(buf, data_out, sz+1);
-  data_out[sz+1] = '\0';
-  *data_len = sz+1;
-  return 1;
-}
-
-/** Set *<b>output</b> to contain a copy of the data in *<b>input</b> */
-int
-buf_set_to_copy(buf_t **output,
-                const buf_t *input)
-{
-  if (*output)
-    buf_free(*output);
-  *output = buf_copy(input);
-  return 0;
-}
-
-/** Log an error and exit if <b>buf</b> is corrupted.
- */
-void
-buf_assert_ok(buf_t *buf)
-{
-  tor_assert(buf);
-  tor_assert(buf->magic == BUFFER_MAGIC);
-
-  if (! buf->head) {
-    tor_assert(!buf->tail);
-    tor_assert(buf->datalen == 0);
-  } else {
-    chunk_t *ch;
-    size_t total = 0;
-    tor_assert(buf->tail);
-    for (ch = buf->head; ch; ch = ch->next) {
-      total += ch->datalen;
-      tor_assert(ch->datalen <= ch->memlen);
-      tor_assert(ch->data >= &ch->mem[0]);
-      tor_assert(ch->data <= &ch->mem[0]+ch->memlen);
-      if (ch->data == &ch->mem[0]+ch->memlen) {
-        /* LCOV_EXCL_START */
-        static int warned = 0;
-        if (! warned) {
-          log_warn(LD_BUG, "Invariant violation in buf.c related to #15083");
-          warned = 1;
-        }
-        /* LCOV_EXCL_STOP */
-      }
-      tor_assert(ch->data+ch->datalen <= &ch->mem[0] + ch->memlen);
-      if (!ch->next)
-        tor_assert(ch == buf->tail);
-    }
-    tor_assert(buf->datalen == total);
-  }
-}
diff --git a/src/lib/container/buffers.h b/src/lib/container/buffers.h
deleted file mode 100644
index c48f83cfc7..0000000000
--- a/src/lib/container/buffers.h
+++ /dev/null
@@ -1,122 +0,0 @@
-/* Copyright (c) 2001 Matej Pfajfar.
- * Copyright (c) 2001-2004, Roger Dingledine.
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2018, The Tor Project, Inc. */
-/* See LICENSE for licensing information */
-
-/**
- * \file buffers.h
- *
- * \brief Header file for buffers.c.
- **/
-
-#ifndef TOR_BUFFERS_H
-#define TOR_BUFFERS_H
-
-#include "lib/cc/compat_compiler.h"
-#include "lib/cc/torint.h"
-#include "lib/testsupport/testsupport.h"
-
-#include <stdarg.h>
-
-typedef struct buf_t buf_t;
-
-buf_t *buf_new(void);
-buf_t *buf_new_with_capacity(size_t size);
-size_t buf_get_default_chunk_size(const buf_t *buf);
-void buf_free_(buf_t *buf);
-#define buf_free(b) FREE_AND_NULL(buf_t, buf_free_, (b))
-void buf_clear(buf_t *buf);
-buf_t *buf_copy(const buf_t *buf);
-
-MOCK_DECL(size_t, buf_datalen, (const buf_t *buf));
-size_t buf_allocation(const buf_t *buf);
-size_t buf_slack(const buf_t *buf);
-
-uint32_t buf_get_oldest_chunk_timestamp(const buf_t *buf, uint32_t now);
-size_t buf_get_total_allocation(void);
-
-int buf_add(buf_t *buf, const char *string, size_t string_len);
-void buf_add_string(buf_t *buf, const char *string);
-void buf_add_printf(buf_t *buf, const char *format, ...)
-  CHECK_PRINTF(2, 3);
-void buf_add_vprintf(buf_t *buf, const char *format, va_list args)
-  CHECK_PRINTF(2, 0);
-int buf_move_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen);
-void buf_move_all(buf_t *buf_out, buf_t *buf_in);
-void buf_peek(const buf_t *buf, char *string, size_t string_len);
-void buf_drain(buf_t *buf, size_t n);
-int buf_get_bytes(buf_t *buf, char *string, size_t string_len);
-int buf_get_line(buf_t *buf, char *data_out, size_t *data_len);
-
-#define PEEK_BUF_STARTSWITH_MAX 16
-int buf_peek_startswith(const buf_t *buf, const char *cmd);
-
-int buf_set_to_copy(buf_t **output,
-                    const buf_t *input);
-
-void buf_assert_ok(buf_t *buf);
-
-int buf_find_string_offset(const buf_t *buf, const char *s, size_t n);
-void buf_pullup(buf_t *buf, size_t bytes,
-                const char **head_out, size_t *len_out);
-char *buf_extract(buf_t *buf, size_t *sz_out);
-
-#ifdef BUFFERS_PRIVATE
-#ifdef TOR_UNIT_TESTS
-buf_t *buf_new_with_data(const char *cp, size_t sz);
-#endif
-size_t buf_preferred_chunk_size(size_t target);
-
-#define DEBUG_CHUNK_ALLOC
-/** A single chunk on a buffer. */
-typedef struct chunk_t {
-  struct chunk_t *next; /**< The next chunk on the buffer. */
-  size_t datalen; /**< The number of bytes stored in this chunk */
-  size_t memlen; /**< The number of usable bytes of storage in <b>mem</b>. */
-#ifdef DEBUG_CHUNK_ALLOC
-  size_t DBG_alloc;
-#endif
-  char *data; /**< A pointer to the first byte of data stored in <b>mem</b>. */
-  uint32_t inserted_time; /**< Timestamp when this chunk was inserted. */
-  char mem[FLEXIBLE_ARRAY_MEMBER]; /**< The actual memory used for storage in
-                * this chunk. */
-} chunk_t;
-
-/** Magic value for buf_t.magic, to catch pointer errors. */
-#define BUFFER_MAGIC 0xB0FFF312u
-/** A resizeable buffer, optimized for reading and writing. */
-struct buf_t {
-  uint32_t magic; /**< Magic cookie for debugging: Must be set to
-                   *   BUFFER_MAGIC. */
-  size_t datalen; /**< How many bytes is this buffer holding right now? */
-  size_t default_chunk_size; /**< Don't allocate any chunks smaller than
-                              * this for this buffer. */
-  chunk_t *head; /**< First chunk in the list, or NULL for none. */
-  chunk_t *tail; /**< Last chunk in the list, or NULL for none. */
-};
-
-chunk_t *buf_add_chunk_with_capacity(buf_t *buf, size_t capacity, int capped);
-/** If a read onto the end of a chunk would be smaller than this number, then
- * just start a new chunk. */
-#define MIN_READ_LEN 8
-
-/** Return the number of bytes that can be written onto <b>chunk</b> without
- * running out of space. */
-static inline size_t
-CHUNK_REMAINING_CAPACITY(const chunk_t *chunk)
-{
-  return (chunk->mem + chunk->memlen) - (chunk->data + chunk->datalen);
-}
-
-/** Return the next character in <b>chunk</b> onto which data can be appended.
- * If the chunk is full, this might be off the end of chunk->mem. */
-static inline char *
-CHUNK_WRITE_PTR(chunk_t *chunk)
-{
-  return chunk->data + chunk->datalen;
-}
-
-#endif /* defined(BUFFERS_PRIVATE) */
-
-#endif /* !defined(TOR_BUFFERS_H) */
diff --git a/src/lib/container/include.am b/src/lib/container/include.am
index e6492098b5..032e4033da 100644
--- a/src/lib/container/include.am
+++ b/src/lib/container/include.am
@@ -7,7 +7,6 @@ endif
 
 src_lib_libtor_container_a_SOURCES =			\
 	src/lib/container/bloomfilt.c			\
-	src/lib/container/buffers.c			\
 	src/lib/container/map.c				\
 	src/lib/container/order.c			\
 	src/lib/container/smartlist.c
@@ -20,7 +19,6 @@ src_lib_libtor_container_testing_a_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
 noinst_HEADERS +=					\
 	src/lib/container/bitarray.h			\
 	src/lib/container/bloomfilt.h			\
-	src/lib/container/buffers.h			\
 	src/lib/container/handles.h			\
 	src/lib/container/map.h				\
 	src/lib/container/order.h			\