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[tor-commits] [tor/master] Fix double-closing a stdio stream
commit cfa9ee5fe708539965f46a31b5d2abe4950179af
Author: Steven Murdoch <Steven.Murdoch@xxxxxxxxxxxx>
Date: Thu Sep 1 13:09:38 2011 +0100
Fix double-closing a stdio stream
After a stream reached eof, we fclose it, but then
test_util_spawn_background_partial_read() reads from it again, which causes
an error and thus another fclose(). Some platforms are fine with this, others
(e.g. debian-sid-i386) trigger a double-free() error. The actual code used by
Tor (log_from_pipe() and tor_check_port_forwarding()) handle this case
correctly.
---
src/common/util.c | 18 +++++++++++++-----
src/common/util.h | 3 ++-
src/test/test_util.c | 18 ++++++++++++------
3 files changed, 27 insertions(+), 12 deletions(-)
diff --git a/src/common/util.c b/src/common/util.c
index 7cd9dd8..db6b00f 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -3583,14 +3583,19 @@ tor_read_all_handle(HANDLE h, char *buf, size_t count,
* <b>process</b> is NULL, the function will return immediately if there is
* nothing more to read. Otherwise data will be read until end of file, or
* <b>count</b> bytes are read. Returns the number of bytes read, or -1 on
- * error. */
+ * error. Sets <b>eof</b> to true if <b>eof</b> is not NULL and the end of the
+ * file has been reached. */
ssize_t
tor_read_all_handle(FILE *h, char *buf, size_t count,
- const process_handle_t *process)
+ const process_handle_t *process,
+ int *eof)
{
size_t numread = 0;
char *retval;
+ if (eof)
+ *eof = 0;
+
if (count > SIZE_T_CEILING || count > SSIZE_T_MAX)
return -1;
@@ -3599,7 +3604,10 @@ tor_read_all_handle(FILE *h, char *buf, size_t count,
retval = fgets(buf+numread, (int)(count-numread), h);
if (NULL == retval) {
if (feof(h)) {
+ log_debug(LD_GENERAL, "fgets() reached end of file");
fclose(h);
+ if (eof)
+ *eof = 1;
break;
} else {
if (EAGAIN == errno) {
@@ -3620,7 +3628,7 @@ tor_read_all_handle(FILE *h, char *buf, size_t count,
numread += strlen(retval);
}
- log_debug(LD_GENERAL, "fgets read %d bytes from handle", (int)numread);
+ log_debug(LD_GENERAL, "fgets() read %d bytes from handle", (int)numread);
return (ssize_t)numread;
}
#endif
@@ -3635,7 +3643,7 @@ tor_read_all_from_process_stdout(const process_handle_t *process_handle,
process_handle);
#else
return tor_read_all_handle(process_handle->stdout_handle, buf, count,
- process_handle);
+ process_handle, NULL);
#endif
}
@@ -3649,7 +3657,7 @@ tor_read_all_from_process_stderr(const process_handle_t *process_handle,
process_handle);
#else
return tor_read_all_handle(process_handle->stderr_handle, buf, count,
- process_handle);
+ process_handle, NULL);
#endif
}
diff --git a/src/common/util.h b/src/common/util.h
index 6211267..c8cce39 100644
--- a/src/common/util.h
+++ b/src/common/util.h
@@ -391,7 +391,8 @@ ssize_t tor_read_all_handle(HANDLE h, char *buf, size_t count,
const process_handle_t *process);
#else
ssize_t tor_read_all_handle(FILE *h, char *buf, size_t count,
- const process_handle_t *process);
+ const process_handle_t *process,
+ int *eof);
#endif
ssize_t tor_read_all_from_process_stdout(
const process_handle_t *process_handle, char *buf, size_t count);
diff --git a/src/test/test_util.c b/src/test/test_util.c
index 06c1be3..7faa0ae 100644
--- a/src/test/test_util.c
+++ b/src/test/test_util.c
@@ -1484,7 +1484,7 @@ test_util_spawn_background_partial_read(void *ptr)
const int expected_status = PROCESS_STATUS_RUNNING;
int retval, exit_code;
- ssize_t pos;
+ ssize_t pos = -1;
process_handle_t process_handle;
char stdout_buf[100], stderr_buf[100];
#ifdef MS_WINDOWS
@@ -1499,6 +1499,7 @@ test_util_spawn_background_partial_read(void *ptr)
"DONE\n",
NULL };
const char *expected_err = "ERR\n";
+ int eof = 0;
#endif
int expected_out_ctr;
(void)ptr;
@@ -1517,8 +1518,10 @@ test_util_spawn_background_partial_read(void *ptr)
pos = tor_read_all_handle(process_handle.stdout_pipe, stdout_buf,
sizeof(stdout_buf) - 1, NULL);
#else
+ /* Check that we didn't read the end of file last time */
+ tt_assert(!eof);
pos = tor_read_all_handle(process_handle.stdout_handle, stdout_buf,
- sizeof(stdout_buf) - 1, NULL);
+ sizeof(stdout_buf) - 1, NULL, &eof);
#endif
log_info(LD_GENERAL, "tor_read_all_handle() returned %d", (int)pos);
@@ -1526,7 +1529,7 @@ test_util_spawn_background_partial_read(void *ptr)
if (0 == pos)
continue;
- tt_int_op(pos, >=, 0);
+ tt_int_op(pos, >, 0);
stdout_buf[pos] = '\0';
tt_str_op(stdout_buf, ==, expected_out[expected_out_ctr]);
tt_int_op(pos, ==, strlen(expected_out[expected_out_ctr]));
@@ -1539,10 +1542,13 @@ test_util_spawn_background_partial_read(void *ptr)
sizeof(stdout_buf) - 1,
&process_handle);
#else
- pos = tor_read_all_handle(process_handle.stdout_handle, stdout_buf,
- sizeof(stdout_buf) - 1,
- &process_handle);
+ if (!eof)
+ pos = tor_read_all_handle(process_handle.stdout_handle, stdout_buf,
+ sizeof(stdout_buf) - 1,
+ &process_handle, &eof);
+ tt_assert(eof)
#endif
+ tt_int_op(pos, ==, 0);
/* Check it terminated correctly */
retval = tor_get_exit_code(process_handle, 1, &exit_code);
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