From 894ffc95a6cccfe1b5aaf4361312b8939e685dff Mon Sep 17 00:00:00 2001 From: =?utf8?q?S=C5=82awomir=20Demeszko?= Date: Mon, 8 Dec 2014 13:27:33 +0100 Subject: [PATCH] Separation of decoding User Data Header from decoding 7 bit message MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit It is preparation for supporting 8 bit and 16 bit encoding. Moving out this code from decode_7bit_field() allows to reuse it in caller function where other than 7 bit decoding will take place. Signed-off-by: SÅ‚awomir Demeszko --- commands-wms.c | 48 +++++++++++++++++++++++------------------------- 1 file changed, 23 insertions(+), 25 deletions(-) diff --git a/commands-wms.c b/commands-wms.c index 5f159ce..9760d85 100644 --- a/commands-wms.c +++ b/commands-wms.c @@ -158,13 +158,13 @@ pdu_decode_7bit_str(char *dest, const unsigned char *data, int data_len, int bit return len; } -static void decode_udh(const unsigned char *data) +static int decode_udh(const unsigned char *data) { const unsigned char *end; - unsigned int type, len; + unsigned int type, len, udh_len; - len = *(data++); - end = data + len; + udh_len = *(data++); + end = data + udh_len; while (data < end) { const unsigned char *val; @@ -185,29 +185,15 @@ static void decode_udh(const unsigned char *data) break; } } + + return udh_len + 1; } -static void decode_7bit_field(char *name, const unsigned char *data, int data_len, bool udh) +static void decode_7bit_field(char *name, const unsigned char *data, int data_len, int bit_offset) { - const unsigned char *udh_start; - char *dest; - int pos_offset = 0; - - if (udh) { - int len = data[0] + 1; - - udh_start = data; - data += len; - data_len -= len; - pos_offset = len % 7; - } - - dest = blobmsg_alloc_string_buffer(&status, name, 3 * (data_len * 8 / 7) + 2); - pdu_decode_7bit_str(dest, data, data_len, pos_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); blobmsg_add_string_buffer(&status); - - if (udh) - decode_udh(udh_start); } static char *pdu_add_semioctet(char *str, char val) @@ -375,8 +361,20 @@ static void cmd_wms_get_message_cb(struct qmi_dev *qmi, struct qmi_request *req, data += 7; } - cur_len = *(data++); - decode_7bit_field("text", data, end - data, !!(first & 0x40)); + data++; + int bit_offset = 0; + + /* User Data Header */ + if (first & 0x40) { + int udh_len = decode_udh(data); + data += udh_len; + bit_offset = udh_len % 7; + } + + if (data >= end) + goto error; + + decode_7bit_field("text", data, end - data, bit_offset); blobmsg_close_table(&status, c); return; -- 2.30.2