<p>Pau Espin Pedrol has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/11789">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">gsm: Deprecate buggy gsm_arfcn2band API and introduce gsm_arfcn2band_rc<br><br>ARFCNs are values in well defined ranges. Until this patch, ARFCNs not<br>belonging to any band were blindly assigned to DCS1800 by<br>gsm_arfcn2band, causing unnoticed bugs and misconfigurations in<br>osmo-bsc.<br><br>Previous API gsm_arfcn2band cannot accomodate this kind of check easily,<br>so let's deprecate it to tell people to use a new API gsm_arfcn2band_rc<br>which performs this kind of checks and allows callers to log failures,<br>misconfigurations, etc.<br>At the same time, modify implementation of gsm_arfcn2band to abort if an<br>invalid ARFCN is passed, this way users of this API can notice they are<br>passing wrong data to it that most probably will produce unexpected<br>results.<br><br>Related: OS#3063<br>Change-Id: I780d452dcebce385469e32ef2fd844df6033393a<br>---<br>M include/osmocom/gsm/gsm_utils.h<br>M src/gsm/gsm_utils.c<br>M src/gsm/libosmogsm.map<br>M utils/osmo-arfcn.c<br>4 files changed, 56 insertions(+), 24 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/89/11789/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmocom/gsm/gsm_utils.h b/include/osmocom/gsm/gsm_utils.h</span><br><span>index 7eda5b9..fe5903d 100644</span><br><span>--- a/include/osmocom/gsm/gsm_utils.h</span><br><span>+++ b/include/osmocom/gsm/gsm_utils.h</span><br><span>@@ -161,7 +161,8 @@</span><br><span> #define ARFCN_UPLINK 0x4000</span><br><span> #define ARFCN_FLAG_MASK 0xf000 /* Reserve the upper 5 bits for flags */</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">-enum gsm_band gsm_arfcn2band(uint16_t arfcn);</span><br><span style="color: hsl(120, 100%, 40%);">+int gsm_arfcn2band_rc(uint16_t arfcn, enum gsm_band *band);</span><br><span style="color: hsl(120, 100%, 40%);">+enum gsm_band gsm_arfcn2band(uint16_t arfcn) OSMO_DEPRECATED("Use gsm_arfcn2band_rc() instead");</span><br><span> </span><br><span> /* Convert an ARFCN to the frequency in MHz * 10 */</span><br><span> uint16_t gsm_arfcn2freq10(uint16_t arfcn, int uplink);</span><br><span>diff --git a/src/gsm/gsm_utils.c b/src/gsm/gsm_utils.c</span><br><span>index 7e6c794..191e0a5 100644</span><br><span>--- a/src/gsm/gsm_utils.c</span><br><span>+++ b/src/gsm/gsm_utils.c</span><br><span>@@ -709,33 +709,58 @@</span><br><span> /*! Resolve GSM band from ARFCN</span><br><span> * In Osmocom, we use the highest bit of the \a arfcn to indicate PCS</span><br><span> * \param[in] arfcn Osmocom ARFCN, highest bit determines PCS mode</span><br><span style="color: hsl(0, 100%, 40%);">- * \returns GSM Band */</span><br><span style="color: hsl(0, 100%, 40%);">-enum gsm_band gsm_arfcn2band(uint16_t arfcn)</span><br><span style="color: hsl(120, 100%, 40%);">+ * \param[out] band GSM Band containing \arfcn if arfcn is valid, undetermined otherwise</span><br><span style="color: hsl(120, 100%, 40%);">+ * \returns 0 if arfcn is valid and \a band was set, negative on error */</span><br><span style="color: hsl(120, 100%, 40%);">+int gsm_arfcn2band_rc(uint16_t arfcn, enum gsm_band *band)</span><br><span> {</span><br><span> int is_pcs = arfcn & ARFCN_PCS;</span><br><span> </span><br><span> arfcn &= ~ARFCN_FLAG_MASK;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- if (is_pcs)</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_1900;</span><br><span style="color: hsl(0, 100%, 40%);">- else if (arfcn <= 124)</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_900;</span><br><span style="color: hsl(0, 100%, 40%);">- else if (arfcn >= 955 && arfcn <= 1023)</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_900;</span><br><span style="color: hsl(0, 100%, 40%);">- else if (arfcn >= 128 && arfcn <= 251)</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_850;</span><br><span style="color: hsl(0, 100%, 40%);">- else if (arfcn >= 512 && arfcn <= 885)</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_1800;</span><br><span style="color: hsl(0, 100%, 40%);">- else if (arfcn >= 259 && arfcn <= 293)</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_450;</span><br><span style="color: hsl(0, 100%, 40%);">- else if (arfcn >= 306 && arfcn <= 340)</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_480;</span><br><span style="color: hsl(0, 100%, 40%);">- else if (arfcn >= 350 && arfcn <= 425)</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_810;</span><br><span style="color: hsl(0, 100%, 40%);">- else if (arfcn >= 438 && arfcn <= 511)</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_750;</span><br><span style="color: hsl(0, 100%, 40%);">- else</span><br><span style="color: hsl(0, 100%, 40%);">- return GSM_BAND_1800;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (is_pcs) {</span><br><span style="color: hsl(120, 100%, 40%);">+ *band = GSM_BAND_1900;</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (arfcn <= 124) {</span><br><span style="color: hsl(120, 100%, 40%);">+ *band = GSM_BAND_900;</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (arfcn >= 955 && arfcn <= 1023) {</span><br><span style="color: hsl(120, 100%, 40%);">+ *band = GSM_BAND_900;</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (arfcn >= 128 && arfcn <= 251) {</span><br><span style="color: hsl(120, 100%, 40%);">+ *band = GSM_BAND_850;</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (arfcn >= 512 && arfcn <= 885) {</span><br><span style="color: hsl(120, 100%, 40%);">+ *band = GSM_BAND_1800;</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (arfcn >= 259 && arfcn <= 293) {</span><br><span style="color: hsl(120, 100%, 40%);">+ *band = GSM_BAND_450;</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (arfcn >= 306 && arfcn <= 340) {</span><br><span style="color: hsl(120, 100%, 40%);">+ *band = GSM_BAND_480;</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (arfcn >= 350 && arfcn <= 425) {</span><br><span style="color: hsl(120, 100%, 40%);">+ *band = GSM_BAND_810;</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (arfcn >= 438 && arfcn <= 511) {</span><br><span style="color: hsl(120, 100%, 40%);">+ *band = GSM_BAND_750;</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ return -1;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+/*! Resolve GSM band from ARFCN, aborts process on invalid ARFCN</span><br><span style="color: hsl(120, 100%, 40%);">+ * In Osmocom, we use the highest bit of the \a arfcn to indicate PCS.</span><br><span style="color: hsl(120, 100%, 40%);">+ * DEPRECATED: Use gsm_arfcn2band_rc instead.</span><br><span style="color: hsl(120, 100%, 40%);">+ * \param[in] arfcn Osmocom ARFCN, highest bit determines PCS mode</span><br><span style="color: hsl(120, 100%, 40%);">+ * \returns GSM Band if ARFCN is valid (part of any valid band), aborts otherwise */</span><br><span style="color: hsl(120, 100%, 40%);">+enum gsm_band gsm_arfcn2band(uint16_t arfcn)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ enum gsm_band band;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (gsm_arfcn2band_rc(arfcn, &band) == 0)</span><br><span style="color: hsl(120, 100%, 40%);">+ return band;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_panic("%s:%d Invalid arfcn %" PRIu16 " passed to gsm_arfcn2band\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ __FILE__, __LINE__, arfcn);</span><br><span> }</span><br><span> </span><br><span> struct gsm_freq_range {</span><br><span>diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map</span><br><span>index 4813e13..74a9d8e 100644</span><br><span>--- a/src/gsm/libosmogsm.map</span><br><span>+++ b/src/gsm/libosmogsm.map</span><br><span>@@ -346,6 +346,7 @@</span><br><span> gsm_7bit_encode_n;</span><br><span> gsm_7bit_encode_n_ussd;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+gsm_arfcn2band_rc;</span><br><span> gsm_arfcn2band;</span><br><span> gsm_arfcn2freq10;</span><br><span> gsm_freq102arfcn;</span><br><span>diff --git a/utils/osmo-arfcn.c b/utils/osmo-arfcn.c</span><br><span>index 61108f8..7d3c16a 100644</span><br><span>--- a/utils/osmo-arfcn.c</span><br><span>+++ b/utils/osmo-arfcn.c</span><br><span>@@ -62,6 +62,7 @@</span><br><span> static int freq2arfcn(int freq10, int uplink)</span><br><span> {</span><br><span> uint16_t arfcn;</span><br><span style="color: hsl(120, 100%, 40%);">+ enum gsm_band band;</span><br><span> </span><br><span> if (uplink != 0 && uplink != 1) {</span><br><span> fprintf(stderr, "Need to specify uplink or downlink\n");</span><br><span>@@ -75,8 +76,12 @@</span><br><span> return -EINVAL;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ if (gsm_arfcn2band_rc(arfcn, &band) < 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ fprintf(stderr, "ARFCN contains no valid band\n");</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> printf("%s: ARFCN %4d\n",</span><br><span style="color: hsl(0, 100%, 40%);">- gsm_band_name(gsm_arfcn2band(arfcn)),</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm_band_name(band),</span><br><span> arfcn & ~ARFCN_FLAG_MASK);</span><br><span> return 0;</span><br><span> }</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/11789">change 11789</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: I780d452dcebce385469e32ef2fd844df6033393a </div>
<div style="display:none"> Gerrit-Change-Number: 11789 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: Pau Espin Pedrol <pespin@sysmocom.de> </div>