<p>dexter has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/12044">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">gsm0808: add encoder for cause codes and use it<br><br>At the moment the all gsm0808 cause codes are encoded directly using the<br>tlv API directly to put a one byte TLV field. This works ok for most<br>situations where the cause code consists of a single byte. However,<br>gsm0808 specifies a two byte cause code model where cause codes may be<br>extended up to two bytes. Lets implement the encoding over and over<br>again, lets rather have an encoder function we can call.<br><br>- Add an encoder function that can generate single byte and extended<br> cause codeds and makes the length decision automatically.<br><br>- Use only this function to append cause codes<br><br>Change-Id: I71d58fad89502a43532f60717ca022c15c73f8bb<br>---<br>M include/osmocom/gsm/gsm0808_utils.h<br>M src/gsm/gsm0808.c<br>M src/gsm/gsm0808_utils.c<br>3 files changed, 43 insertions(+), 12 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/44/12044/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h</span><br><span>index c5bf280..e1dd11e 100644</span><br><span>--- a/include/osmocom/gsm/gsm0808_utils.h</span><br><span>+++ b/include/osmocom/gsm/gsm0808_utils.h</span><br><span>@@ -77,6 +77,7 @@</span><br><span> int gsm0808_cell_id_u_name(char *buf, size_t buflen,</span><br><span> enum CELL_IDENT id_discr, const union gsm0808_cell_id_u *u);</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+uint8_t gsm0808_enc_cause(struct msgb *msg, uint16_t cause);</span><br><span> uint8_t gsm0808_enc_aoip_trasp_addr(struct msgb *msg,</span><br><span> const struct sockaddr_storage *ss);</span><br><span> int gsm0808_dec_aoip_trasp_addr(struct sockaddr_storage *ss,</span><br><span>diff --git a/src/gsm/gsm0808.c b/src/gsm/gsm0808.c</span><br><span>index 04d786e..3e2d8da 100644</span><br><span>--- a/src/gsm/gsm0808.c</span><br><span>+++ b/src/gsm/gsm0808.c</span><br><span>@@ -144,7 +144,7 @@</span><br><span> return NULL;</span><br><span> </span><br><span> msgb_v_put(msg, BSS_MAP_MSG_RESET);</span><br><span style="color: hsl(0, 100%, 40%);">- msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, &cause);</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm0808_enc_cause(msg, cause);</span><br><span> msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));</span><br><span> </span><br><span> return msg;</span><br><span>@@ -193,7 +193,7 @@</span><br><span> </span><br><span> msg->l3h = msgb_tv_put(msg, BSSAP_MSG_BSS_MANAGEMENT, 4);</span><br><span> msgb_v_put(msg, BSS_MAP_MSG_CLEAR_CMD);</span><br><span style="color: hsl(0, 100%, 40%);">- msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, &cause);</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm0808_enc_cause(msg, cause);</span><br><span> </span><br><span> return msg;</span><br><span> }</span><br><span>@@ -276,7 +276,7 @@</span><br><span> </span><br><span> msgb_v_put(msg, BSS_MAP_MSG_CIPHER_MODE_REJECT);</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, (const uint8_t *)&cause);</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm0808_enc_cause(msg, cause);</span><br><span> </span><br><span> msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));</span><br><span> </span><br><span>@@ -289,18 +289,22 @@</span><br><span> * \returns callee-allocated msgb with BSSMAP Cipher Mode Reject message */</span><br><span> struct msgb *gsm0808_create_cipher_reject_ext(enum gsm0808_cause_class class, uint8_t ext)</span><br><span> {</span><br><span style="color: hsl(0, 100%, 40%);">- uint8_t c[2];</span><br><span style="color: hsl(120, 100%, 40%);">+ uint16_t cause;</span><br><span> struct msgb *msg = msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,</span><br><span> "bssmap: cipher mode reject");</span><br><span> if (!msg)</span><br><span> return NULL;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- c[0] = 0x80 | (class << 4); /* set the high bit to indicate extended cause */</span><br><span style="color: hsl(0, 100%, 40%);">- c[1] = ext;</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Set cause code class in the upper byte */</span><br><span style="color: hsl(120, 100%, 40%);">+ cause = 0x80 | (class << 4);</span><br><span style="color: hsl(120, 100%, 40%);">+ cause = cause << 8;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Set cause code extension in the lower byte */</span><br><span style="color: hsl(120, 100%, 40%);">+ cause |= ext;</span><br><span> </span><br><span> msgb_v_put(msg, BSS_MAP_MSG_CIPHER_MODE_REJECT);</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- msgb_tlv_put(msg, GSM0808_IE_CAUSE, 2, c);</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm0808_enc_cause(msg, cause);</span><br><span> </span><br><span> msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));</span><br><span> </span><br><span>@@ -575,7 +579,7 @@</span><br><span> return NULL;</span><br><span> </span><br><span> msgb_v_put(msg, BSS_MAP_MSG_ASSIGMENT_FAILURE);</span><br><span style="color: hsl(0, 100%, 40%);">- msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, &cause);</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm0808_enc_cause(msg, cause);</span><br><span> </span><br><span> /* RR cause 3.2.2.22 */</span><br><span> if (rr_cause)</span><br><span>@@ -617,7 +621,7 @@</span><br><span> return NULL;</span><br><span> </span><br><span> msgb_v_put(msg, BSS_MAP_MSG_CLEAR_RQST);</span><br><span style="color: hsl(0, 100%, 40%);">- msgb_tlv_put(msg, GSM0808_IE_CAUSE, 1, &cause);</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm0808_enc_cause(msg, cause);</span><br><span> msg->l3h = msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));</span><br><span> </span><br><span> return msg;</span><br><span>@@ -754,7 +758,7 @@</span><br><span> msgb_v_put(msg, BSS_MAP_MSG_HANDOVER_REQUIRED);</span><br><span> </span><br><span> /* Cause, 3.2.2.5 */</span><br><span style="color: hsl(0, 100%, 40%);">- msgb_tlv_put(msg, GSM0808_IE_CAUSE, params->cause & 0x80? 2 : 1, (const uint8_t*)¶ms->cause);</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm0808_enc_cause(msg, params->cause);</span><br><span> </span><br><span> /* Cell Identifier List, 3.2.2.27 */</span><br><span> gsm0808_enc_cell_id_list2(msg, ¶ms->cil);</span><br><span>@@ -879,7 +883,7 @@</span><br><span> msgb_v_put(msg, BSS_MAP_MSG_HANDOVER_FAILURE);</span><br><span> </span><br><span> /* Cause, 3.2.2.5 */</span><br><span style="color: hsl(0, 100%, 40%);">- msgb_tlv_put(msg, GSM0808_IE_CAUSE, params->cause & 0x80? 2 : 1, (const uint8_t*)¶ms->cause);</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm0808_enc_cause(msg, params->cause);</span><br><span> </span><br><span> /* RR Cause, 3.2.2.22 */</span><br><span> if (params->rr_cause_present)</span><br><span>@@ -910,7 +914,7 @@</span><br><span> msgb_v_put(msg, BSS_MAP_MSG_HANDOVER_PERFORMED);</span><br><span> </span><br><span> /* Cause, 3.2.2.5 */</span><br><span style="color: hsl(0, 100%, 40%);">- msgb_tlv_put(msg, GSM0808_IE_CAUSE, gsm0808_cause_ext(params->cause) ? 2 : 1, (const uint8_t *)¶ms->cause);</span><br><span style="color: hsl(120, 100%, 40%);">+ gsm0808_enc_cause(msg, params->cause);</span><br><span> </span><br><span> /* Cell Identifier, 3.2.2.17 */</span><br><span> gsm0808_enc_cell_id(msg, ¶ms->cell_id);</span><br><span>diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c</span><br><span>index c58d828..1252857 100644</span><br><span>--- a/src/gsm/gsm0808_utils.c</span><br><span>+++ b/src/gsm/gsm0808_utils.c</span><br><span>@@ -48,6 +48,32 @@</span><br><span> * \file gsm0808_utils.c</span><br><span> */</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+/*! Encode TS 08.08 AoIP Cause IE</span><br><span style="color: hsl(120, 100%, 40%);">+ * \param[out] msg Message Buffer to which to append IE</span><br><span style="color: hsl(120, 100%, 40%);">+ * \param[in] cause Cause code to be used in IE</span><br><span style="color: hsl(120, 100%, 40%);">+ * \returns number of bytes added to \a msg */</span><br><span style="color: hsl(120, 100%, 40%);">+uint8_t gsm0808_enc_cause(struct msgb *msg, uint16_t cause)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ /* See also 3GPP TS 48.008 3.2.2.5 Cause */</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t *old_tail;</span><br><span style="color: hsl(120, 100%, 40%);">+ bool extended;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t buf[2];</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ old_tail = msg->tail;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ extended = gsm0808_cause_ext(cause >> 8);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (extended) {</span><br><span style="color: hsl(120, 100%, 40%);">+ buf[1] = (uint8_t) (cause & 0xff);</span><br><span style="color: hsl(120, 100%, 40%);">+ buf[0] = (uint8_t) ((cause >> 8) & 0xff);</span><br><span style="color: hsl(120, 100%, 40%);">+ } else</span><br><span style="color: hsl(120, 100%, 40%);">+ buf[0] = (uint8_t) (cause & 0xff);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ msgb_tlv_put(msg, GSM0808_IE_CAUSE, extended ? 2 : 1, buf);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ return (uint8_t) (msg->tail - old_tail);</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /*! Encode TS 08.08 AoIP transport address IE</span><br><span> * \param[out] msg Message Buffer to which to append IE</span><br><span> * \param[in] ss Socket Address to be used in IE</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/12044">change 12044</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/12044"/><meta itemprop="name" content="View Change"/></div></div>
<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: I71d58fad89502a43532f60717ca022c15c73f8bb </div>
<div style="display:none"> Gerrit-Change-Number: 12044 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: dexter <pmaier@sysmocom.de> </div>