Add backtrace-based error path testing mechanism

The new TEST_FAIL and GET_FAIL control interface commands can be used
similarly to the earlier TEST_ALLOC_FAIL/GET_ALLOC_FAIL design. The new
version is more generic framework allowing any function to be annotated
for failure testing with the TEST_FAIL() macro. This mechanism is only
available in builds with CONFIG_WPA_TRACE_BFD=y and
CONFIG_TESTING_OPTIONS=y. For other builds, the TEST_FAIL() macro is
defined to return 0 to allow the compiler to remove the test code from
normal production builds.

As the first test site, allow os_get_random() to be marked for failing
based on call backtrace.

Signed-off-by: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2015-06-28 21:35:43 +03:00
parent 0937ea746b
commit 2da525651d
4 changed files with 170 additions and 0 deletions

View File

@ -1746,6 +1746,45 @@ static int hostapd_ctrl_get_alloc_fail(struct hostapd_data *hapd,
#endif /* WPA_TRACE_BFD */
}
static int hostapd_ctrl_test_fail(struct hostapd_data *hapd, char *cmd)
{
#ifdef WPA_TRACE_BFD
extern char wpa_trace_test_fail_func[256];
extern unsigned int wpa_trace_test_fail_after;
char *pos;
wpa_trace_test_fail_after = atoi(cmd);
pos = os_strchr(cmd, ':');
if (pos) {
pos++;
os_strlcpy(wpa_trace_test_fail_func, pos,
sizeof(wpa_trace_test_fail_func));
} else {
wpa_trace_test_fail_after = 0;
}
return 0;
#else /* WPA_TRACE_BFD */
return -1;
#endif /* WPA_TRACE_BFD */
}
static int hostapd_ctrl_get_fail(struct hostapd_data *hapd,
char *buf, size_t buflen)
{
#ifdef WPA_TRACE_BFD
extern char wpa_trace_test_fail_func[256];
extern unsigned int wpa_trace_test_fail_after;
return os_snprintf(buf, buflen, "%u:%s", wpa_trace_test_fail_after,
wpa_trace_test_fail_func);
#else /* WPA_TRACE_BFD */
return -1;
#endif /* WPA_TRACE_BFD */
}
#endif /* CONFIG_TESTING_OPTIONS */
@ -2079,6 +2118,11 @@ static void hostapd_ctrl_iface_receive(int sock, void *eloop_ctx,
} else if (os_strcmp(buf, "GET_ALLOC_FAIL") == 0) {
reply_len = hostapd_ctrl_get_alloc_fail(hapd, reply,
reply_size);
} else if (os_strncmp(buf, "TEST_FAIL ", 10) == 0) {
if (hostapd_ctrl_test_fail(hapd, buf + 10) < 0)
reply_len = -1;
} else if (os_strcmp(buf, "GET_FAIL") == 0) {
reply_len = hostapd_ctrl_get_fail(hapd, reply, reply_size);
#endif /* CONFIG_TESTING_OPTIONS */
} else if (os_strncmp(buf, "CHAN_SWITCH ", 12) == 0) {
if (hostapd_ctrl_iface_chan_switch(hapd->iface, buf + 12))

View File

@ -646,4 +646,12 @@ int os_exec(const char *program, const char *arg, int wait_completion);
#define strcpy OS_DO_NOT_USE_strcpy
#endif /* OS_REJECT_C_LIB_FUNCTIONS */
#if defined(WPA_TRACE_BFD) && defined(CONFIG_TESTING_OPTIONS)
#define TEST_FAIL() testing_test_fail()
int testing_test_fail(void);
#else
#define TEST_FAIL() 0
#endif
#endif /* OS_H */

View File

@ -226,6 +226,9 @@ int os_get_random(unsigned char *buf, size_t len)
FILE *f;
size_t rc;
if (TEST_FAIL())
return -1;
f = fopen("/dev/urandom", "rb");
if (f == NULL) {
printf("Could not open /dev/urandom.\n");
@ -548,6 +551,78 @@ static int testing_fail_alloc(void)
return 0;
}
char wpa_trace_test_fail_func[256] = { 0 };
unsigned int wpa_trace_test_fail_after;
int testing_test_fail(void)
{
const char *func[WPA_TRACE_LEN];
size_t i, res, len;
char *pos, *next;
int match;
if (!wpa_trace_test_fail_after)
return 0;
res = wpa_trace_calling_func(func, WPA_TRACE_LEN);
i = 0;
if (i < res && os_strcmp(func[i], __func__) == 0)
i++;
pos = wpa_trace_test_fail_func;
match = 0;
while (i < res) {
int allow_skip = 1;
int maybe = 0;
if (*pos == '=') {
allow_skip = 0;
pos++;
} else if (*pos == '?') {
maybe = 1;
pos++;
}
next = os_strchr(pos, ';');
if (next)
len = next - pos;
else
len = os_strlen(pos);
if (os_memcmp(pos, func[i], len) != 0) {
if (maybe && next) {
pos = next + 1;
continue;
}
if (allow_skip) {
i++;
continue;
}
return 0;
}
if (!next) {
match = 1;
break;
}
pos = next + 1;
i++;
}
if (!match)
return 0;
wpa_trace_test_fail_after--;
if (wpa_trace_test_fail_after == 0) {
wpa_printf(MSG_INFO, "TESTING: fail at %s",
wpa_trace_test_fail_func);
for (i = 0; i < res; i++)
wpa_printf(MSG_INFO, "backtrace[%d] = %s",
(int) i, func[i]);
return 1;
}
return 0;
}
#else
static inline int testing_fail_alloc(void)

View File

@ -7562,6 +7562,44 @@ static int wpas_ctrl_get_alloc_fail(struct wpa_supplicant *wpa_s,
#endif /* WPA_TRACE_BFD */
}
static int wpas_ctrl_test_fail(struct wpa_supplicant *wpa_s, char *cmd)
{
#ifdef WPA_TRACE_BFD
extern char wpa_trace_test_fail_func[256];
extern unsigned int wpa_trace_test_fail_after;
char *pos;
wpa_trace_test_fail_after = atoi(cmd);
pos = os_strchr(cmd, ':');
if (pos) {
pos++;
os_strlcpy(wpa_trace_test_fail_func, pos,
sizeof(wpa_trace_test_fail_func));
} else {
wpa_trace_test_fail_after = 0;
}
return 0;
#else /* WPA_TRACE_BFD */
return -1;
#endif /* WPA_TRACE_BFD */
}
static int wpas_ctrl_get_fail(struct wpa_supplicant *wpa_s,
char *buf, size_t buflen)
{
#ifdef WPA_TRACE_BFD
extern char wpa_trace_test_fail_func[256];
extern unsigned int wpa_trace_test_fail_after;
return os_snprintf(buf, buflen, "%u:%s", wpa_trace_test_fail_after,
wpa_trace_test_fail_func);
#else /* WPA_TRACE_BFD */
return -1;
#endif /* WPA_TRACE_BFD */
}
#endif /* CONFIG_TESTING_OPTIONS */
@ -8579,6 +8617,11 @@ char * wpa_supplicant_ctrl_iface_process(struct wpa_supplicant *wpa_s,
reply_len = -1;
} else if (os_strcmp(buf, "GET_ALLOC_FAIL") == 0) {
reply_len = wpas_ctrl_get_alloc_fail(wpa_s, reply, reply_size);
} else if (os_strncmp(buf, "TEST_FAIL ", 10) == 0) {
if (wpas_ctrl_test_fail(wpa_s, buf + 10) < 0)
reply_len = -1;
} else if (os_strcmp(buf, "GET_FAIL") == 0) {
reply_len = wpas_ctrl_get_fail(wpa_s, reply, reply_size);
#endif /* CONFIG_TESTING_OPTIONS */
} else if (os_strncmp(buf, "VENDOR_ELEM_ADD ", 16) == 0) {
if (wpas_ctrl_vendor_elem_add(wpa_s, buf + 16) < 0)