mi: fix get_log_page chunked offset check

In our get_log_page helper, we're incorrectly checking the requested
chunk offset against the chunk len, rather than the overall length -
this means we can't query anything but the first chunk.

This change fixes this to check against the overall length instead, and
adds an additional check to ensure we're not requesting more than the
full data size.

We also add a testcase for the chunking code.

Reported-by: Hao Jiang <[email protected]>
Signed-off-by: Jeremy Kerr <[email protected]>

Author: jk-ozlabs

src/nvme/mi.c

@@ -498,7 +498,7 @@ static int __nvme_mi_admin_get_log(nvme_mi_ctrl_t ctrl,
 		return -1;
 	}
 
-	if (offset < 0 || offset >= len) {
+	if (offset < 0 || offset >= args->len || offset + len > args->len) {
 		errno = EINVAL;
 		return -1;
 	}

test/mi.c

@@ -1699,6 +1699,86 @@ static void test_admin_sanitize_nvm(struct nvme_mi_ep *ep)
 	assert(!rc);
 }
 
+/* test that we set the correct offset and size on get_log() calls that
+ * are split into multiple requests */
+struct log_data {
+	int n;
+};
+
+static int test_admin_get_log_split_cb(struct nvme_mi_ep *ep,
+				       struct nvme_mi_req *req,
+				       struct nvme_mi_resp *resp,
+				       void *data)
+{
+	struct log_data *ldata = data;
+	uint32_t len, off;
+	__u8 *rq_hdr;
+
+	assert(req->data_len == 0);
+
+	rq_hdr = (__u8 *)req->hdr;
+
+	assert(rq_hdr[4] == nvme_admin_get_log_page);
+
+	/* from the MI message's DOFST/DLEN fields */
+	off = rq_hdr[31] << 24 | rq_hdr[30] << 16 | rq_hdr[29] << 8 | rq_hdr[28];
+	len = rq_hdr[35] << 24 | rq_hdr[34] << 16 | rq_hdr[33] << 8 | rq_hdr[32];
+
+	/* we should have a full-sized start and middle, and a short end */
+	switch (ldata->n) {
+	case 0:
+		assert(len == 4096);
+		assert(off == 0);
+		break;
+	case 1:
+		assert(len == 4096);
+		assert(off == 4096);
+		break;
+	case 2:
+		assert(len == 4);
+		assert(off == 4096 * 2);
+		break;
+	default:
+		assert(0);
+	}
+
+	/* ensure we've sized the expected response correctly */
+	assert(resp->data_len == len);
+	memset(resp->data, ldata->n & 0xff, len);
+
+	test_transport_resp_calc_mic(resp);
+
+	ldata->n++;
+
+	return 0;
+}
+
+static void test_admin_get_log_split(struct nvme_mi_ep *ep)
+{
+	unsigned char buf[4096 * 2 + 4];
+	struct nvme_get_log_args args;
+	struct log_data ldata;
+	nvme_mi_ctrl_t ctrl;
+	int rc;
+
+	ldata.n = 0;
+	test_set_transport_callback(ep, test_admin_get_log_split_cb, &ldata);
+
+	ctrl = nvme_mi_init_ctrl(ep, 5);
+
+	args.args_size = sizeof(args);
+	args.lid = 1;
+	args.log = buf;
+	args.len = sizeof(buf);
+
+	rc = nvme_mi_admin_get_log(ctrl, &args);
+
+	assert(!rc);
+
+	/* we should have sent three commands */
+	assert(ldata.n == 3);
+}
+
 #define DEFINE_TEST(name) { #name, test_ ## name }
 struct test {
 	const char *name;
@@ -1738,6 +1818,7 @@ struct test {
 	DEFINE_TEST(admin_fw_commit),
 	DEFINE_TEST(admin_format_nvm),
 	DEFINE_TEST(admin_sanitize_nvm),
+	DEFINE_TEST(admin_get_log_split),
 };
 
 static void run_test(struct test *test, FILE *logfd, nvme_mi_ep_t ep)