qcdm: fix endian issues for BE platforms

And add a testcase for packet encapsulation to ensure we don't
have further endian issues in the future.

4 files changed, 33 insertions, 5 deletions

diff --git a/libqcdm/src/utils.c b/libqcdm/src/utils.c
index 9b9ac5f0..b5815482 100644
--- a/libqcdm/src/utils.c
+++ b/libqcdm/src/utils.c
@@ -194,7 +194,8 @@ dm_encapsulate_buffer (char *inbuf,
     g_return_val_if_fail (inbuf_len >= cmd_len + 2, 0); /* space for CRC */
     g_return_val_if_fail (outbuf != NULL, 0);
 
-    crc = GUINT16_TO_LE (crc16 (inbuf, cmd_len));
+    /* Add the CRC */
+    crc = crc16 (inbuf, cmd_len);
     inbuf[cmd_len++] = crc & 0xFF;
     inbuf[cmd_len++] = (crc >> 8) & 0xFF;
 
@@ -296,8 +297,9 @@ dm_decapsulate_buffer (const char *inbuf,
 
     /* Check the CRC of the packet's data */
     crc = crc16 (outbuf, unesc_len - 2);
-    pkt_crc = *((guint16 *) &outbuf[unesc_len - 2]);
-    if (crc != GUINT_FROM_LE (pkt_crc)) {
+    pkt_crc = outbuf[unesc_len - 2] & 0xFF;
+    pkt_crc |= (outbuf[unesc_len - 1] & 0xFF) << 8;
+    if (crc != pkt_crc) {
         *out_used = pkt_len + 1; /* packet + CRC + 0x7E */
         return FALSE;
     }
diff --git a/libqcdm/tests/test-qcdm-utils.c b/libqcdm/tests/test-qcdm-utils.c
index 34de8394..27ec8d61 100644
--- a/libqcdm/tests/test-qcdm-utils.c
+++ b/libqcdm/tests/test-qcdm-utils.c
@@ -21,7 +21,7 @@
 #include "test-qcdm-utils.h"
 #include "utils.h"
 
-static const char inbuf[] = {
+static const char decap_inbuf[] = {
     0x40, 0x03, 0x00, 0x01, 0x00, 0x19, 0xf0, 0x00, 0x16, 0x00, 0x21, 0x00,
     0x1c, 0x00, 0xd8, 0x00, 0x3f, 0x00, 0x56, 0x01, 0x3f, 0x00, 0x15, 0x00,
     0x1a, 0x00, 0x11, 0x01, 0x3f, 0x00, 0x92, 0x01, 0x3f, 0x00, 0x39, 0x00,
@@ -52,7 +52,7 @@ test_utils_decapsulate_buffer (void *f, void *data)
     gsize used = 0;
     gboolean more = FALSE;
 
-    success = dm_decapsulate_buffer (inbuf, sizeof (inbuf),
+    success = dm_decapsulate_buffer (decap_inbuf, sizeof (decap_inbuf),
                                      outbuf, sizeof (outbuf),
                                      &decap_len, &used, &more);
     g_assert (success);
@@ -61,3 +61,26 @@ test_utils_decapsulate_buffer (void *f, void *data)
     g_assert (more == FALSE);
 }
 
+
+static const char encap_outbuf[] = {
+    0x4b, 0x05, 0x08, 0x00, 0x01, 0xdd, 0x7e
+};
+
+void
+test_utils_encapsulate_buffer (void *f, void *data)
+{
+    char cmdbuf[10];
+    char outbuf[512];
+    gsize encap_len = 0;
+
+    cmdbuf[0] = 0x4B;   /* DIAG_CMD_SUBSYS */
+    cmdbuf[1] = 0x05;   /* DIAG_SUBSYS_HDR */
+    cmdbuf[2] = 0x08;   /* first byte of DIAG_SUBSYS_HDR_STATE_INFO in LE */
+    cmdbuf[3] = 0x00;   /* second byte of DIAG_SUBSYS_HDR_STATE_INFO in LE */
+
+    encap_len = dm_encapsulate_buffer (cmdbuf, 4, sizeof (cmdbuf),
+                                       &outbuf[0], sizeof (outbuf));
+    g_assert (encap_len == sizeof (encap_outbuf));
+    g_assert (memcmp (outbuf, encap_outbuf, encap_len) == 0);
+}
+
diff --git a/libqcdm/tests/test-qcdm-utils.h b/libqcdm/tests/test-qcdm-utils.h
index 767a72ae..80386664 100644
--- a/libqcdm/tests/test-qcdm-utils.h
+++ b/libqcdm/tests/test-qcdm-utils.h
@@ -20,5 +20,7 @@
 
 void test_utils_decapsulate_buffer (void *f, void *data);
 
+void test_utils_encapsulate_buffer (void *f, void *data);
+
 #endif  /* TEST_QCDM_UTILS_H */
 
diff --git a/libqcdm/tests/test-qcdm.c b/libqcdm/tests/test-qcdm.c
index 0a6801fb..d17e8085 100644
--- a/libqcdm/tests/test-qcdm.c
+++ b/libqcdm/tests/test-qcdm.c
@@ -84,6 +84,7 @@ int main (int argc, char **argv)
     g_test_suite_add (suite, TESTCASE (test_escape2, NULL));
     g_test_suite_add (suite, TESTCASE (test_escape_unescape, NULL));
     g_test_suite_add (suite, TESTCASE (test_utils_decapsulate_buffer, NULL));
+    g_test_suite_add (suite, TESTCASE (test_utils_encapsulate_buffer, NULL));
     g_test_suite_add (suite, TESTCASE (test_result_string, NULL));
     g_test_suite_add (suite, TESTCASE (test_result_uint32, NULL));
     g_test_suite_add (suite, TESTCASE (test_result_uint8, NULL));