commit fca91a7793f24fc5f2d043167317fd47dd58f1ed Author: teor teor2345@gmail.com Date: Tue Dec 13 19:13:57 2016 -0500

for fuzzing: Add a function to make a buf with given contents

(Teor wrote the code, nick extracted it into a smaller patch.) --- src/or/buffers.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ src/or/buffers.h | 3 +++ 2 files changed, 51 insertions(+)

diff --git a/src/or/buffers.c b/src/or/buffers.c index 8981fd2..58ce573 100644 --- a/src/or/buffers.c +++ b/src/or/buffers.c @@ -281,6 +281,7 @@ buf_pullup(buf_t *buf, size_t bytes) }

#ifdef TOR_UNIT_TESTS +/* Return the data from the first chunk of buf in cp, and its length in sz. */ void buf_get_first_chunk_data(const buf_t *buf, const char **cp, size_t *sz) { @@ -292,6 +293,53 @@ buf_get_first_chunk_data(const buf_t *buf, const char **cp, size_t *sz) *sz = buf->head->datalen; } } + +/* 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); + assert_buf_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); + assert_buf_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]; + assert_buf_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

/** Remove the first <b>n</b> bytes from buf. */ diff --git a/src/or/buffers.h b/src/or/buffers.h index 52b21d5..08d9471 100644 --- a/src/or/buffers.h +++ b/src/or/buffers.h @@ -64,7 +64,10 @@ void assert_buf_ok(buf_t *buf); #ifdef BUFFERS_PRIVATE STATIC int buf_find_string_offset(const buf_t *buf, const char *s, size_t n); STATIC void buf_pullup(buf_t *buf, size_t bytes); +#ifdef TOR_UNIT_TESTS void buf_get_first_chunk_data(const buf_t *buf, const char **cp, size_t *sz); +buf_t *buf_new_with_data(const char *cp, size_t sz); +#endif STATIC size_t preferred_chunk_size(size_t target);

#define DEBUG_CHUNK_ALLOC