From 10093a9249e3c197991a37e15a0de4e617c6bb6b Mon Sep 17 00:00:00 2001 From: =?utf8?q?S=C5=82awomir=20Demeszko?= Date: Mon, 8 Dec 2014 19:05:25 +0100 Subject: [PATCH] Fix character "@" added at end of received messages MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If 7 bit message encoded on 8 bit cells has one last bit occupying whole byte it need to be padded with 7 zero bits. To not mistake these last 7 bits with a character with code 0 (@) we need to check length from User Data Length field and not rely on actual length of received data. An example can be message "abcdefg" encoded as "61 f1 98 5c 36 9f 01", it is decoded as "abcdefg@". Signed-off-by: SÅ‚awomir Demeszko --- commands-wms.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/commands-wms.c b/commands-wms.c index 74f50aa..47d4d76 100644 --- a/commands-wms.c +++ b/commands-wms.c @@ -1,5 +1,8 @@ #include "qmi-message.h" +#define MIN(a,b) (((a)<(b))?(a):(b)) +#define CEILDIV(x,y) (((x) + (y) - 1) / (y)) + static void cmd_wms_list_messages_cb(struct qmi_dev *qmi, struct qmi_request *req, struct qmi_msg *msg) { struct qmi_wms_list_messages_response res; @@ -191,8 +194,9 @@ static int decode_udh(const unsigned char *data) static void decode_7bit_field(char *name, const unsigned char *data, int data_len, int bit_offset) { - char *dest = blobmsg_alloc_string_buffer(&status, name, 3 * (data_len * 8 / 7) + 2); - pdu_decode_7bit_str(dest, data, data_len, bit_offset); + char *dest = blobmsg_alloc_string_buffer(&status, name, 3 * data_len + 2); + pdu_decode_7bit_str(dest, data, CEILDIV(data_len * 7, 8), bit_offset); + dest[data_len] = 0; blobmsg_add_string_buffer(&status); } @@ -366,12 +370,13 @@ static void cmd_wms_get_message_cb(struct qmi_dev *qmi, struct qmi_request *req, data += 7; } - data++; + int message_len = *(data++); + int udh_len = 0; int bit_offset = 0; /* User Data Header */ if (first & 0x40) { - int udh_len = decode_udh(data); + udh_len = decode_udh(data); data += udh_len; bit_offset = udh_len % 7; } @@ -382,15 +387,19 @@ static void cmd_wms_get_message_cb(struct qmi_dev *qmi, struct qmi_request *req, switch(dcs & 0x0c) { case 0x00: /* 7 bit GSM alphabet */ - decode_7bit_field("text", data, end - data, bit_offset); + message_len = message_len - CEILDIV(udh_len * 8, 7); + message_len = MIN(message_len, CEILDIV((end - data) * 8, 7)); + decode_7bit_field("text", data, message_len, bit_offset); break; case 0x04: /* 8 bit data */ - blobmsg_add_hex(&status, "data", data, end - data); + message_len = MIN(message_len - udh_len, end - data); + blobmsg_add_hex(&status, "data", data, message_len); break; case 0x08: /* 16 bit UCS-2 string */ - blobmsg_add_hex(&status, "ucs-2", data, end - data); + message_len = MIN(message_len - udh_len, end - data); + blobmsg_add_hex(&status, "ucs-2", data, message_len); break; default: goto error; -- 2.25.1