[OpenWrt-Devel] [PATCH 8/8] generic: platform/mikrotik: support LZOR encoding

Thibaut VARÈNE hacks at slashdirt.org
Fri Apr 3 14:20:56 EDT 2020


Some newer MikroTik RouterBOARD devices use a new encoding scheme
for their WLAN calibration data. This patch provides support for
decoding this new scheme.

Signed-off-by: Thibaut VARÈNE <hacks at slashdirt.org>
---
 .../drivers/platform/mikrotik/rb_hardconfig.c      | 261 ++++++++++++++++++++-
 1 file changed, 260 insertions(+), 1 deletion(-)

diff --git a/target/linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c b/target/linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c
index 567db76e35..97f1e95763 100644
--- a/target/linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c
+++ b/target/linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c
@@ -37,7 +37,7 @@
 
 #include "routerboot.h"
 
-#define RB_HARDCONFIG_VER		"0.01"
+#define RB_HARDCONFIG_VER		"0.02"
 #define PR_PREFIX			"[rb_hardconfig] "
 
 /* ID values for hardware settings */
@@ -76,6 +76,190 @@ static struct kobject *hc_kobj;
 static u8 *hc_buf;		// ro buffer after init(): no locking required
 static size_t hc_buflen;
 
+/*
+ * For LZOR style WLAN data unpacking.
+ * This binary blob is prepended to the data encoded on some devices as
+ * RB_ID_WLAN_DATA, the result is then first decompressed with LZO, and then
+ * finally RLE-decoded.
+ * This binary blob has been extracted from RouterOS by
+ * https://forum.openwrt.org/u/ius
+ */
+static const u8 hc_lzor_prefix[] = {
+	0x00, 0x05, 0x4c, 0x4c, 0x44, 0x00, 0x34, 0xfe,
+	0xfe, 0x34, 0x11, 0x3c, 0x1e, 0x3c, 0x2e, 0x3c,
+	0x4c, 0x34, 0x00, 0x52, 0x62, 0x92, 0xa2, 0xb2,
+	0xc3, 0x2a, 0x14, 0x00, 0x00, 0x05, 0xfe, 0x6a,
+	0x3c, 0x16, 0x32, 0x16, 0x11, 0x1e, 0x12, 0x46,
+	0x32, 0x46, 0x11, 0x4e, 0x12, 0x36, 0x32, 0x36,
+	0x11, 0x3e, 0x12, 0x5a, 0x9a, 0x64, 0x00, 0x04,
+	0xfe, 0x10, 0x3c, 0x00, 0x01, 0x00, 0x00, 0x28,
+	0x0c, 0x00, 0x0f, 0xfe, 0x14, 0x00, 0x24, 0x24,
+	0x23, 0x24, 0x24, 0x23, 0x25, 0x22, 0x21, 0x21,
+	0x23, 0x22, 0x21, 0x22, 0x21, 0x2d, 0x38, 0x00,
+	0x0c, 0x25, 0x25, 0x24, 0x25, 0x25, 0x24, 0x23,
+	0x22, 0x21, 0x20, 0x23, 0x21, 0x21, 0x22, 0x21,
+	0x2d, 0x38, 0x00, 0x28, 0xb0, 0x00, 0x00, 0x22,
+	0x00, 0x00, 0xc0, 0xfe, 0x03, 0x00, 0xc0, 0x00,
+	0x62, 0xff, 0x62, 0xff, 0xfe, 0x06, 0x00, 0xbb,
+	0xff, 0xba, 0xff, 0xfe, 0x08, 0x00, 0x9e, 0xff,
+	0xfe, 0x0a, 0x00, 0x53, 0xff, 0xfe, 0x02, 0x00,
+	0x20, 0xff, 0xb1, 0xfe, 0xfe, 0xb2, 0xfe, 0xfe,
+	0xed, 0xfe, 0xfe, 0xfe, 0x04, 0x00, 0x3a, 0xff,
+	0x3a, 0xff, 0xde, 0xfd, 0x5f, 0x04, 0x33, 0xff,
+	0x4c, 0x74, 0x03, 0x05, 0x05, 0xff, 0x6d, 0xfe,
+	0xfe, 0x6d, 0xfe, 0xfe, 0xaf, 0x08, 0x63, 0xff,
+	0x64, 0x6f, 0x08, 0xac, 0xff, 0xbf, 0x6d, 0x08,
+	0x7a, 0x6d, 0x08, 0x96, 0x74, 0x04, 0x00, 0x08,
+	0x79, 0xff, 0xda, 0xfe, 0xfe, 0xdb, 0xfe, 0xfe,
+	0x56, 0xff, 0xfe, 0x04, 0x00, 0x5e, 0xff, 0x5e,
+	0xff, 0x6c, 0xfe, 0xfe, 0xfe, 0x06, 0x00, 0x41,
+	0xff, 0x7f, 0x74, 0x03, 0x00, 0x11, 0x44, 0xff,
+	0xa9, 0xfe, 0xfe, 0xa9, 0xfe, 0xfe, 0xa5, 0x8f,
+	0x01, 0x00, 0x08, 0x01, 0x01, 0x02, 0x04, 0x08,
+	0x02, 0x04, 0x08, 0x08, 0x01, 0x01, 0xfe, 0x22,
+	0x00, 0x4c, 0x60, 0x64, 0x8c, 0x90, 0xd0, 0xd4,
+	0xd8, 0x5c, 0x10, 0x09, 0xd8, 0xff, 0xb0, 0xff,
+	0x00, 0x00, 0xba, 0xff, 0x14, 0x00, 0xba, 0xff,
+	0x64, 0x00, 0x00, 0x08, 0xfe, 0x06, 0x00, 0x74,
+	0xff, 0x42, 0xff, 0xce, 0xff, 0x60, 0xff, 0x0a,
+	0x00, 0xb4, 0x00, 0xa0, 0x00, 0xa0, 0xfe, 0x07,
+	0x00, 0x0a, 0x00, 0xb0, 0xff, 0x96, 0x4d, 0x00,
+	0x56, 0x57, 0x18, 0xa6, 0xff, 0x92, 0x70, 0x11,
+	0x00, 0x12, 0x90, 0x90, 0x76, 0x5a, 0x54, 0x54,
+	0x4c, 0x46, 0x38, 0x00, 0x10, 0x10, 0x08, 0xfe,
+	0x05, 0x00, 0x38, 0x29, 0x25, 0x23, 0x22, 0x22,
+	0x1f, 0x00, 0x00, 0x00, 0xf6, 0xe1, 0xdd, 0xf8,
+	0xfe, 0x00, 0xfe, 0x15, 0x00, 0x00, 0xd0, 0x02,
+	0x74, 0x02, 0x08, 0xf8, 0xe5, 0xde, 0x02, 0x04,
+	0x04, 0xfd, 0x00, 0x00, 0x00, 0x07, 0x50, 0x2d,
+	0x01, 0x90, 0x90, 0x76, 0x60, 0xb0, 0x07, 0x07,
+	0x0c, 0x0c, 0x04, 0xfe, 0x05, 0x00, 0x66, 0x66,
+	0x5a, 0x56, 0xbc, 0x01, 0x06, 0xfc, 0xfc, 0xf1,
+	0xfe, 0x07, 0x00, 0x24, 0x95, 0x70, 0x64, 0x18,
+	0x06, 0x2c, 0xff, 0xb5, 0xfe, 0xfe, 0xb5, 0xfe,
+	0xfe, 0xe2, 0x8c, 0x24, 0x02, 0x2f, 0xff, 0x2f,
+	0xff, 0xb4, 0x78, 0x02, 0x05, 0x73, 0xff, 0xed,
+	0xfe, 0xfe, 0x4f, 0xff, 0x36, 0x74, 0x1e, 0x09,
+	0x4f, 0xff, 0x50, 0xff, 0xfe, 0x16, 0x00, 0x70,
+	0xac, 0x70, 0x8e, 0xac, 0x40, 0x0e, 0x01, 0x70,
+	0x7f, 0x8e, 0xac, 0x6c, 0x00, 0x0b, 0xfe, 0x02,
+	0x00, 0xfe, 0x0a, 0x2c, 0x2a, 0x2a, 0x28, 0x26,
+	0x1e, 0x1e, 0xfe, 0x02, 0x20, 0x65, 0x20, 0x00,
+	0x00, 0x05, 0x12, 0x00, 0x11, 0x1e, 0x11, 0x11,
+	0x41, 0x1e, 0x41, 0x11, 0x31, 0x1e, 0x31, 0x11,
+	0x70, 0x75, 0x7a, 0x7f, 0x84, 0x89, 0x8e, 0x93,
+	0x98, 0x30, 0x20, 0x00, 0x02, 0x00, 0xfe, 0x06,
+	0x3c, 0xbc, 0x32, 0x0c, 0x00, 0x00, 0x2a, 0x12,
+	0x1e, 0x12, 0x2e, 0x12, 0xcc, 0x12, 0x11, 0x1a,
+	0x1e, 0x1a, 0x2e, 0x1a, 0x4c, 0x10, 0x1e, 0x10,
+	0x11, 0x18, 0x1e, 0x42, 0x1e, 0x42, 0x2e, 0x42,
+	0xcc, 0x42, 0x11, 0x4a, 0x1e, 0x4a, 0x2e, 0x4a,
+	0x4c, 0x40, 0x1e, 0x40, 0x11, 0x48, 0x1e, 0x32,
+	0x1e, 0x32, 0x2e, 0x32, 0xcc, 0x32, 0x11, 0x3a,
+	0x1e, 0x3a, 0x2e, 0x3a, 0x4c, 0x30, 0x1e, 0x30,
+	0x11, 0x38, 0x1e, 0x27, 0x9a, 0x01, 0x9d, 0xa2,
+	0x2f, 0x28, 0x00, 0x00, 0x46, 0xde, 0xc4, 0xbf,
+	0xa6, 0x9d, 0x81, 0x7b, 0x5c, 0x61, 0x40, 0xc7,
+	0xc0, 0xae, 0xa9, 0x8c, 0x83, 0x6a, 0x62, 0x50,
+	0x3e, 0xce, 0xc2, 0xae, 0xa3, 0x8c, 0x7b, 0x6a,
+	0x5a, 0x50, 0x35, 0xd7, 0xc2, 0xb7, 0xa4, 0x95,
+	0x7e, 0x72, 0x5a, 0x59, 0x37, 0xfe, 0x02, 0xf8,
+	0x8c, 0x95, 0x90, 0x8f, 0x00, 0xd7, 0xc0, 0xb7,
+	0xa2, 0x95, 0x7b, 0x72, 0x56, 0x59, 0x32, 0xc7,
+	0xc3, 0xae, 0xad, 0x8c, 0x85, 0x6a, 0x63, 0x50,
+	0x3e, 0xce, 0xc3, 0xae, 0xa4, 0x8c, 0x7c, 0x6a,
+	0x59, 0x50, 0x34, 0xd7, 0xc2, 0xb7, 0xa5, 0x95,
+	0x7e, 0x72, 0x59, 0x59, 0x36, 0xfc, 0x05, 0x00,
+	0x02, 0xce, 0xc5, 0xae, 0xa5, 0x95, 0x83, 0x72,
+	0x5c, 0x59, 0x36, 0xbf, 0xc6, 0xa5, 0xab, 0x8c,
+	0x8c, 0x6a, 0x67, 0x50, 0x41, 0x64, 0x07, 0x00,
+	0x02, 0x95, 0x8c, 0x72, 0x65, 0x59, 0x3f, 0xce,
+	0xc7, 0xae, 0xa8, 0x95, 0x86, 0x72, 0x5f, 0x59,
+	0x39, 0xfe, 0x02, 0xf8, 0x8b, 0x7c, 0x0b, 0x09,
+	0xb7, 0xc2, 0x9d, 0xa4, 0x83, 0x85, 0x6a, 0x6b,
+	0x50, 0x44, 0xb7, 0xc1, 0x64, 0x01, 0x00, 0x06,
+	0x61, 0x5d, 0x48, 0x3d, 0xae, 0xc4, 0x9d, 0xad,
+	0x7b, 0x85, 0x61, 0x66, 0x48, 0x46, 0xae, 0xc3,
+	0x95, 0xa3, 0x72, 0x7c, 0x59, 0x56, 0x38, 0x31,
+	0x7c, 0x0b, 0x00, 0x0c, 0x96, 0x91, 0x8f, 0x00,
+	0xb7, 0xc0, 0xa5, 0xab, 0x8c, 0x8a, 0x6a, 0x64,
+	0x50, 0x3c, 0xb7, 0xc0, 0x9d, 0xa0, 0x83, 0x80,
+	0x6a, 0x64, 0x50, 0x3d, 0xb7, 0xc5, 0x9d, 0xa5,
+	0x83, 0x87, 0x6c, 0x08, 0x07, 0xae, 0xc0, 0x9d,
+	0xa8, 0x83, 0x88, 0x6a, 0x6d, 0x50, 0x46, 0xfc,
+	0x05, 0x00, 0x16, 0xbf, 0xc0, 0xa5, 0xa2, 0x8c,
+	0x7f, 0x6a, 0x57, 0x50, 0x2f, 0xb7, 0xc7, 0xa5,
+	0xb1, 0x8c, 0x8e, 0x72, 0x6d, 0x59, 0x45, 0xbf,
+	0xc6, 0xa5, 0xa8, 0x8c, 0x87, 0x6a, 0x5f, 0x50,
+	0x37, 0xbf, 0xc2, 0xa5, 0xa4, 0x8c, 0x83, 0x6a,
+	0x5c, 0x50, 0x34, 0xbc, 0x05, 0x00, 0x0e, 0x90,
+	0x00, 0xc7, 0xc2, 0xae, 0xaa, 0x95, 0x82, 0x7b,
+	0x60, 0x61, 0x3f, 0xb7, 0xc6, 0xa5, 0xb1, 0x8c,
+	0x8d, 0x72, 0x6b, 0x61, 0x51, 0xbf, 0xc4, 0xa5,
+	0xa5, 0x8c, 0x82, 0x72, 0x61, 0x59, 0x39, 0x6c,
+	0x26, 0x03, 0x95, 0x82, 0x7b, 0x61, 0x61, 0x40,
+	0xfc, 0x05, 0x00, 0x00, 0x7e, 0xd7, 0xc3, 0xb7,
+	0xa8, 0x9d, 0x80, 0x83, 0x5d, 0x6a, 0x3f, 0xbf,
+	0xc7, 0xa5, 0xa8, 0x8c, 0x84, 0x72, 0x60, 0x61,
+	0x46, 0xbf, 0xc2, 0xae, 0xb0, 0x9d, 0x92, 0x83,
+	0x6f, 0x6a, 0x50, 0xd7, 0xc3, 0xb7, 0xa7, 0x9d,
+	0x80, 0x83, 0x5e, 0x6a, 0x40, 0xfe, 0x02, 0xf8,
+	0x8d, 0x96, 0x90, 0x90, 0xfe, 0x05, 0x00, 0x8a,
+	0xc4, 0x63, 0xb8, 0x3c, 0xa6, 0x29, 0x97, 0x16,
+	0x81, 0x84, 0xb7, 0x5b, 0xa9, 0x33, 0x94, 0x1e,
+	0x83, 0x11, 0x70, 0xb8, 0xc2, 0x70, 0xb1, 0x4d,
+	0xa3, 0x2a, 0x8d, 0x1b, 0x7b, 0xa8, 0xbc, 0x68,
+	0xab, 0x47, 0x9d, 0x27, 0x87, 0x18, 0x75, 0xae,
+	0xc6, 0x7d, 0xbb, 0x4d, 0xaa, 0x1c, 0x84, 0x11,
+	0x72, 0xa3, 0xbb, 0x6e, 0xad, 0x3c, 0x97, 0x24,
+	0x85, 0x16, 0x71, 0x80, 0xb2, 0x57, 0xa4, 0x30,
+	0x8e, 0x1c, 0x7c, 0x10, 0x68, 0xbb, 0xbd, 0x75,
+	0xac, 0x4f, 0x9e, 0x2b, 0x87, 0x1a, 0x76, 0x96,
+	0xc5, 0x5e, 0xb5, 0x3e, 0xa5, 0x1f, 0x8c, 0x12,
+	0x7a, 0xc1, 0xc6, 0x42, 0x9f, 0x27, 0x8c, 0x16,
+	0x77, 0x0f, 0x67, 0x9d, 0xbc, 0x68, 0xad, 0x36,
+	0x95, 0x20, 0x83, 0x11, 0x6d, 0x9b, 0xb8, 0x67,
+	0xa8, 0x34, 0x90, 0x1f, 0x7c, 0x10, 0x67, 0x9e,
+	0xc9, 0x6a, 0xbb, 0x37, 0xa4, 0x20, 0x90, 0x11,
+	0x7b, 0xc6, 0xc8, 0x47, 0xa4, 0x2a, 0x90, 0x18,
+	0x7b, 0x10, 0x6c, 0xae, 0xc4, 0x5d, 0xad, 0x37,
+	0x9a, 0x1f, 0x85, 0x13, 0x75, 0x70, 0xad, 0x42,
+	0x99, 0x25, 0x84, 0x17, 0x74, 0x0b, 0x56, 0x87,
+	0xc8, 0x57, 0xb8, 0x2b, 0x9e, 0x19, 0x8a, 0x0d,
+	0x74, 0xa7, 0xc8, 0x6e, 0xb9, 0x36, 0xa0, 0x1f,
+	0x8b, 0x11, 0x75, 0x94, 0xbe, 0x4b, 0xa5, 0x2a,
+	0x92, 0x18, 0x7c, 0x0f, 0x6b, 0xaf, 0xc0, 0x58,
+	0xa8, 0x34, 0x94, 0x1d, 0x7d, 0x12, 0x6d, 0x82,
+	0xc0, 0x52, 0xb0, 0x25, 0x94, 0x14, 0x7f, 0x0c,
+	0x68, 0x84, 0xbf, 0x3e, 0xa4, 0x22, 0x8e, 0x10,
+	0x76, 0x0b, 0x65, 0x88, 0xb6, 0x42, 0x9b, 0x26,
+	0x87, 0x14, 0x70, 0x0c, 0x5f, 0xc5, 0xc2, 0x3e,
+	0x97, 0x23, 0x83, 0x13, 0x6c, 0x0c, 0x5c, 0xb1,
+	0xc9, 0x76, 0xbc, 0x4a, 0xaa, 0x20, 0x8d, 0x12,
+	0x78, 0x93, 0xbf, 0x46, 0xa3, 0x26, 0x8d, 0x14,
+	0x74, 0x0c, 0x62, 0xc8, 0xc4, 0x3b, 0x97, 0x21,
+	0x82, 0x11, 0x6a, 0x0a, 0x59, 0xa3, 0xb9, 0x68,
+	0xa9, 0x30, 0x8d, 0x1a, 0x78, 0x0f, 0x61, 0xa0,
+	0xc9, 0x73, 0xbe, 0x50, 0xb1, 0x30, 0x9f, 0x14,
+	0x80, 0x83, 0xb7, 0x3c, 0x9a, 0x20, 0x84, 0x0e,
+	0x6a, 0x0a, 0x57, 0xac, 0xc2, 0x68, 0xb0, 0x2e,
+	0x92, 0x19, 0x7c, 0x0d, 0x63, 0x93, 0xbe, 0x62,
+	0xb0, 0x3c, 0x9e, 0x1a, 0x80, 0x0e, 0x6b, 0xbb,
+	0x02, 0xa0, 0x02, 0xa0, 0x02, 0x6f, 0x00, 0x75,
+	0x00, 0x75, 0x00, 0x00, 0x00, 0xad, 0x02, 0xb3,
+	0x02, 0x6f, 0x00, 0x87, 0x00, 0x85, 0xfe, 0x03,
+	0x00, 0xc2, 0x02, 0x82, 0x4d, 0x92, 0x6e, 0x4d,
+	0xb1, 0xa8, 0x84, 0x01, 0x00, 0x07, 0x7e, 0x00,
+	0xa8, 0x02, 0xa4, 0x02, 0xa4, 0x02, 0xa2, 0x00,
+	0xa6, 0x00, 0xa6, 0x00, 0x00, 0x00, 0xb4, 0x02,
+	0xb4, 0x02, 0x92, 0x00, 0x96, 0x00, 0x96, 0x46,
+	0x04, 0xb0, 0x02, 0x64, 0x02, 0x0a, 0x8c, 0x00,
+	0x90, 0x02, 0x98, 0x02, 0x98, 0x02, 0x0e, 0x01,
+	0x11, 0x01, 0x11, 0x50, 0xc3, 0x08, 0x88, 0x02,
+	0x88, 0x02, 0x19, 0x01, 0x02, 0x01, 0x02, 0x01,
+	0xf3, 0x2d, 0x00, 0x00
+};
+
 /* Array of known hw_options bits with human-friendly parsing */
 static struct hc_hwopt {
 	const u32 bit;
@@ -288,6 +472,75 @@ fail:
 	return ret;
 }
 
+/*
+ * If the RB_ID_WLAN_DATA payload starts with RB_MAGIC_LZOR, then past
+ * that magic number is a payload that must be appended to the hc_lzor_prefix,
+ * the resulting blob is LZO-compressed. In the LZO decompression result,
+ * the RB_MAGIC_ERD magic number (aligned) must be located. Following that
+ * magic, there is a routerboot tag node (id 0x1) locating the RLE-encoded
+ * calibration data payload.
+ */
+static int hc_wlan_data_unpack_lzor(const u8 *inbuf, size_t inlen,
+				    void *outbuf, size_t *outlen)
+{
+	size_t templen;
+	u16 rle_ofs, rle_len;
+	u8 *tempbuf;
+	int ret;
+
+	templen = inlen + sizeof(hc_lzor_prefix);
+	if (templen > *outlen)
+		return -EFBIG;
+
+	/* Temporary buffer same size as the outbuf */
+	tempbuf = kmalloc(*outlen, GFP_KERNEL);
+	if (!outbuf)
+		return -ENOMEM;
+
+	/* Concatenate into the outbuf */
+	memcpy(outbuf, hc_lzor_prefix, sizeof(hc_lzor_prefix));
+	memcpy(outbuf + sizeof(hc_lzor_prefix), inbuf, inlen);
+
+	/* LZO-decompress templen bytes of outbuf into the tempbuf */
+	ret = lzo1x_decompress_safe(outbuf, templen, tempbuf, outlen);
+	if (ret) {
+		pr_debug(PR_PREFIX "LZO decompression error (%d)\n", ret);
+		goto fail;
+	}
+	templen = *outlen;
+
+	/* post decompression we have a blob (possibly byproduct of
+	 * the lzo dictionary). We need to find the RB_MAGIC_ERD. The
+	 * magic number seems to be aligned in the decompression output.
+	 */
+
+	while (RB_MAGIC_ERD != *(u32 *)tempbuf) {
+		tempbuf += 4;
+		templen -= 4;
+	}
+
+	/* Past magic. Look for tag node */
+	ret = routerboot_tag_find(tempbuf, templen, 0x1, &rle_ofs, &rle_len);
+	if (ret) {
+		pr_debug(PR_PREFIX "RLE data not found\n");
+		goto fail;
+	}
+
+	if (rle_len > templen) {
+		pr_debug(PR_PREFIX "Invalid RLE data length\n");
+		goto fail;
+	}
+
+	/* RLE-decode tempbuf back into the outbuf */
+	ret = routerboot_rle_decode(tempbuf+rle_ofs, rle_len, outbuf, outlen);
+	if (ret)
+		pr_debug(PR_PREFIX "RLE decoding error (%d)\n", ret);
+
+fail:
+	kfree(tempbuf);
+	return ret;
+}
+
 static int hc_wlan_data_unpack(const size_t tofs, size_t tlen,
 			       void *outbuf, size_t *outlen)
 {
@@ -304,6 +557,12 @@ static int hc_wlan_data_unpack(const size_t tofs, size_t tlen,
 
 	ret = -ENODATA;
 	switch (magic) {
+	case RB_MAGIC_LZOR:
+		/* Skip magic */
+		lbuf += sizeof(magic);
+		tlen -= sizeof(magic);
+		ret = hc_wlan_data_unpack_lzor(lbuf, tlen, outbuf, outlen);
+		break;
 	case RB_MAGIC_ERD:
 		/* Skip magic */
 		lbuf += sizeof(magic);
-- 
2.11.0


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