<p>Neels Hofmeyr has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/12154">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">gsm48_mi_to_string: use osmo_bcd2str(), fix some corner cases<br><br>By using osmo_bcd2str(), ensure that the resulting string is always nul<br>terminated, and always return strlen()+1 whether truncated or not.<br><br>Still keep up the previous return value style, even if that isn't consistent at<br>all.<br><br>The difference between IMSI/IMEI and TMSI return values remains and is not part<br>of this patch.<br><br>Change-Id: I1b51b72a721e1cc9d69796b804ebda741ff0f36b<br>---<br>M src/gsm/gsm48.c<br>M tests/gsm0408/gsm0408_test.c<br>M tests/gsm0408/gsm0408_test.ok<br>3 files changed, 22 insertions(+), 28 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/54/12154/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/gsm/gsm48.c b/src/gsm/gsm48.c</span><br><span>index e684a3c..df4b4c1 100644</span><br><span>--- a/src/gsm/gsm48.c</span><br><span>+++ b/src/gsm/gsm48.c</span><br><span>@@ -650,7 +650,7 @@</span><br><span> int gsm48_mi_to_string(char *string, const int str_len, const uint8_t *mi,</span><br><span> const int mi_len)</span><br><span> {</span><br><span style="color: hsl(0, 100%, 40%);">- int i;</span><br><span style="color: hsl(120, 100%, 40%);">+ int rc;</span><br><span> uint8_t mi_type;</span><br><span> char *str_cur = string;</span><br><span> uint32_t tmsi;</span><br><span>@@ -670,17 +670,15 @@</span><br><span> case GSM_MI_TYPE_IMSI:</span><br><span> case GSM_MI_TYPE_IMEI:</span><br><span> case GSM_MI_TYPE_IMEISV:</span><br><span style="color: hsl(0, 100%, 40%);">- *str_cur++ = osmo_bcd2char(mi[0] >> 4);</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- for (i = 1; i < mi_len; i++) {</span><br><span style="color: hsl(0, 100%, 40%);">- if (str_cur + 2 >= string + str_len)</span><br><span style="color: hsl(0, 100%, 40%);">- return str_cur - string;</span><br><span style="color: hsl(0, 100%, 40%);">- *str_cur++ = osmo_bcd2char(mi[i] & 0xf);</span><br><span style="color: hsl(0, 100%, 40%);">- /* skip last nibble in last input byte when GSM_EVEN */</span><br><span style="color: hsl(0, 100%, 40%);">- if( (i != mi_len-1) || (mi[0] & GSM_MI_ODD))</span><br><span style="color: hsl(0, 100%, 40%);">- *str_cur++ = osmo_bcd2char(mi[i] >> 4);</span><br><span style="color: hsl(0, 100%, 40%);">- }</span><br><span style="color: hsl(0, 100%, 40%);">- break;</span><br><span style="color: hsl(120, 100%, 40%);">+ rc = osmo_bcd2str(string, str_len, mi,</span><br><span style="color: hsl(120, 100%, 40%);">+ 1, mi_len * 2 - ((mi[0] & GSM_MI_ODD) ? 0 : 1));</span><br><span style="color: hsl(120, 100%, 40%);">+ /* osmo_bcd2str() returns snprintf style strlen(), this returns bytes written. */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (rc < str_len)</span><br><span style="color: hsl(120, 100%, 40%);">+ return rc + 1;</span><br><span style="color: hsl(120, 100%, 40%);">+ else if (!str_len)</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ else</span><br><span style="color: hsl(120, 100%, 40%);">+ return strlen(string) + 1;</span><br><span> default:</span><br><span> break;</span><br><span> }</span><br><span>diff --git a/tests/gsm0408/gsm0408_test.c b/tests/gsm0408/gsm0408_test.c</span><br><span>index d38969b..7dbb97d 100644</span><br><span>--- a/tests/gsm0408/gsm0408_test.c</span><br><span>+++ b/tests/gsm0408/gsm0408_test.c</span><br><span>@@ -393,7 +393,6 @@</span><br><span> .expect_mi_tlv_hex = "170449322453",</span><br><span> .str_size = 4,</span><br><span> .expect_str = "423",</span><br><span style="color: hsl(0, 100%, 40%);">- .expect_rc = 3, /* exception: on truncation, gsm48_mi_to_string() returns strlen(), not bytes! */</span><br><span> },</span><br><span> {</span><br><span> .mi_type = GSM_MI_TYPE_IMEI,</span><br><span>@@ -421,7 +420,6 @@</span><br><span> .expect_mi_tlv_hex = "170a937856341290785634f2",</span><br><span> .str_size = 16,</span><br><span> .expect_str = "987654321098765",</span><br><span style="color: hsl(0, 100%, 40%);">- .expect_rc = 15, /* exception: on truncation, gsm48_mi_to_string() returns strlen(), not bytes! */</span><br><span> },</span><br><span> {</span><br><span> /* gsm48 treats TMSI as decimal string */</span><br><span>diff --git a/tests/gsm0408/gsm0408_test.ok b/tests/gsm0408/gsm0408_test.ok</span><br><span>index 1dc4249..2db58de 100644</span><br><span>--- a/tests/gsm0408/gsm0408_test.ok</span><br><span>+++ b/tests/gsm0408/gsm0408_test.ok</span><br><span>@@ -23,8 +23,7 @@</span><br><span> -> MI-str="4234235" rc=8</span><br><span> - IMSI 4234235</span><br><span> -> MI-TLV-hex='170449322453'</span><br><span style="color: hsl(0, 100%, 40%);">- -> MI-str="423" rc=3</span><br><span style="color: hsl(0, 100%, 40%);">- ERROR: resulting string is not explicitly nul terminated</span><br><span style="color: hsl(120, 100%, 40%);">+ -> MI-str="423" rc=4</span><br><span> - IMEI 123456789012345</span><br><span> -> MI-TLV-hex='17081a32547698103254'</span><br><span> -> MI-str="123456789012345" rc=16</span><br><span>@@ -39,8 +38,7 @@</span><br><span> -> MI-str="987654321098765432" rc=19</span><br><span> - IMEI-SV 987654321098765432</span><br><span> -> MI-TLV-hex='170a937856341290785634f2'</span><br><span style="color: hsl(0, 100%, 40%);">- -> MI-str="987654321098765" rc=15</span><br><span style="color: hsl(0, 100%, 40%);">- ERROR: resulting string is not explicitly nul terminated</span><br><span style="color: hsl(120, 100%, 40%);">+ -> MI-str="987654321098765" rc=16</span><br><span> - TMSI 305419896</span><br><span> -> MI-TLV-hex='1705f412345678'</span><br><span> -> MI-str="305419896" rc=9</span><br><span>@@ -66,14 +64,14 @@</span><br><span> Decoding zero length Mobile Identities</span><br><span> - MI type: IMSI</span><br><span> - writing to zero-length string:</span><br><span style="color: hsl(0, 100%, 40%);">- rc=1</span><br><span style="color: hsl(0, 100%, 40%);">- ERROR: Wrote to invalid memory!</span><br><span style="color: hsl(120, 100%, 40%);">+ rc=0</span><br><span style="color: hsl(120, 100%, 40%);">+ nothing written</span><br><span> - writing to 1-byte-length string:</span><br><span> rc=1</span><br><span style="color: hsl(0, 100%, 40%);">- ERROR: Wrote unexpected string "1!!!!"</span><br><span style="color: hsl(120, 100%, 40%);">+ returned empty string</span><br><span> - decode zero-length mi:</span><br><span style="color: hsl(0, 100%, 40%);">- rc=2</span><br><span style="color: hsl(0, 100%, 40%);">- ERROR: expected empty string, got output string: "1"</span><br><span style="color: hsl(120, 100%, 40%);">+ rc=1</span><br><span style="color: hsl(120, 100%, 40%);">+ returned empty string</span><br><span> - MI type: TMSI</span><br><span> - writing to zero-length string:</span><br><span> rc=1</span><br><span>@@ -96,14 +94,14 @@</span><br><span> returned empty string</span><br><span> - MI type: IMSI | GSM_MI_ODD</span><br><span> - writing to zero-length string:</span><br><span style="color: hsl(0, 100%, 40%);">- rc=1</span><br><span style="color: hsl(0, 100%, 40%);">- ERROR: Wrote to invalid memory!</span><br><span style="color: hsl(120, 100%, 40%);">+ rc=0</span><br><span style="color: hsl(120, 100%, 40%);">+ nothing written</span><br><span> - writing to 1-byte-length string:</span><br><span> rc=1</span><br><span style="color: hsl(0, 100%, 40%);">- ERROR: Wrote unexpected string "1!!!!"</span><br><span style="color: hsl(120, 100%, 40%);">+ returned empty string</span><br><span> - decode zero-length mi:</span><br><span style="color: hsl(0, 100%, 40%);">- rc=2</span><br><span style="color: hsl(0, 100%, 40%);">- ERROR: expected empty string, got output string: "1"</span><br><span style="color: hsl(120, 100%, 40%);">+ rc=1</span><br><span style="color: hsl(120, 100%, 40%);">+ returned empty string</span><br><span> - MI type: TMSI | GSM_MI_ODD</span><br><span> - writing to zero-length string:</span><br><span> rc=1</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/12154">change 12154</a>. 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<div style="display:none"> Gerrit-Project: libosmocore </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>
<div style="display:none"> Gerrit-Change-Id: I1b51b72a721e1cc9d69796b804ebda741ff0f36b </div>
<div style="display:none"> Gerrit-Change-Number: 12154 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: Neels Hofmeyr <nhofmeyr@sysmocom.de> </div>