gsm/sms: Moved utility functions of SMS processing to new gsm0411_utils.c
Written-by: Andreas Eversberg <jolly@eversberg.eu>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/src/gsm/gsm0411_utils.c b/src/gsm/gsm0411_utils.c
new file mode 100644
index 0000000..21938bf
--- /dev/null
+++ b/src/gsm/gsm0411_utils.c
@@ -0,0 +1,306 @@
+/* Point-to-Point (PP) Short Message Service (SMS)
+ * Support on Mobile Radio Interface
+ * 3GPP TS 04.11 version 7.1.0 Release 1998 / ETSI TS 100 942 V7.1.0 */
+
+/* (C) 2008 by Daniel Willmann <daniel@totalueberwachung.de>
+ * (C) 2009 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2010 by On-Waves
+ * (C) 2011 by Andreas Eversberg <jolly@eversberg.eu>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+#include <time.h>
+#include <string.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/logging.h>
+
+#include <osmocom/gsm/gsm48.h>
+#include <osmocom/gsm/protocol/gsm_04_11.h>
+
+#define GSM411_ALLOC_SIZE 1024
+#define GSM411_ALLOC_HEADROOM 128
+
+struct msgb *gsm411_msgb_alloc(void)
+{
+ return msgb_alloc_headroom(GSM411_ALLOC_SIZE, GSM411_ALLOC_HEADROOM,
+ "GSM 04.11");
+}
+
+/* Turn int into semi-octet representation: 98 => 0x89 */
+static uint8_t bcdify(uint8_t value)
+{
+ uint8_t ret;
+
+ ret = value / 10;
+ ret |= (value % 10) << 4;
+
+ return ret;
+}
+
+/* Turn semi-octet representation into int: 0x89 => 98 */
+static uint8_t unbcdify(uint8_t value)
+{
+ uint8_t ret;
+
+ if ((value & 0x0F) > 9 || (value >> 4) > 9)
+ LOGP(DLSMS, LOGL_ERROR,
+ "unbcdify got too big nibble: 0x%02X\n", value);
+
+ ret = (value&0x0F)*10;
+ ret += value>>4;
+
+ return ret;
+}
+
+/* Generate 03.40 TP-SCTS */
+void gsm340_gen_scts(uint8_t *scts, time_t time)
+{
+ struct tm *tm = gmtime(&time);
+
+ *scts++ = bcdify(tm->tm_year % 100);
+ *scts++ = bcdify(tm->tm_mon + 1);
+ *scts++ = bcdify(tm->tm_mday);
+ *scts++ = bcdify(tm->tm_hour);
+ *scts++ = bcdify(tm->tm_min);
+ *scts++ = bcdify(tm->tm_sec);
+ *scts++ = bcdify(0); /* GMT */
+}
+
+/* Decode 03.40 TP-SCTS (into utc/gmt timestamp) */
+time_t gsm340_scts(uint8_t *scts)
+{
+ struct tm tm;
+ uint8_t yr = unbcdify(*scts++);
+ int ofs;
+
+ memset(&tm, 0x00, sizeof(struct tm));
+
+ if (yr <= 80)
+ tm.tm_year = 100 + yr;
+ else
+ tm.tm_year = yr;
+ tm.tm_mon = unbcdify(*scts++) - 1;
+ tm.tm_mday = unbcdify(*scts++);
+ tm.tm_hour = unbcdify(*scts++);
+ tm.tm_min = unbcdify(*scts++);
+ tm.tm_sec = unbcdify(*scts++);
+
+ /* according to gsm 03.40 time zone is
+ "expressed in quarters of an hour" */
+ ofs = unbcdify(*scts++) * 15*60;
+
+ return mktime(&tm) - ofs;
+}
+
+/* Return the default validity period in minutes */
+static unsigned long gsm340_vp_default(void)
+{
+ unsigned long minutes;
+ /* Default validity: two days */
+ minutes = 24 * 60 * 2;
+ return minutes;
+}
+
+/* Decode validity period format 'relative' */
+static unsigned long gsm340_vp_relative(uint8_t *sms_vp)
+{
+ /* Chapter 9.2.3.12.1 */
+ uint8_t vp;
+ unsigned long minutes;
+
+ vp = *(sms_vp);
+ if (vp <= 143)
+ minutes = vp + 1 * 5;
+ else if (vp <= 167)
+ minutes = 12*60 + (vp-143) * 30;
+ else if (vp <= 196)
+ minutes = vp-166 * 60 * 24;
+ else
+ minutes = vp-192 * 60 * 24 * 7;
+ return minutes;
+}
+
+/* Decode validity period format 'absolute' */
+static unsigned long gsm340_vp_absolute(uint8_t *sms_vp)
+{
+ /* Chapter 9.2.3.12.2 */
+ time_t expires, now;
+ unsigned long minutes;
+
+ expires = gsm340_scts(sms_vp);
+ now = time(NULL);
+ if (expires <= now)
+ minutes = 0;
+ else
+ minutes = (expires-now)/60;
+ return minutes;
+}
+
+/* Decode validity period format 'relative in integer representation' */
+static unsigned long gsm340_vp_relative_integer(uint8_t *sms_vp)
+{
+ uint8_t vp;
+ unsigned long minutes;
+ vp = *(sms_vp);
+ if (vp == 0) {
+ LOGP(DLSMS, LOGL_ERROR,
+ "reserved relative_integer validity period\n");
+ return gsm340_vp_default();
+ }
+ minutes = vp/60;
+ return minutes;
+}
+
+/* Decode validity period format 'relative in semi-octet representation' */
+static unsigned long gsm340_vp_relative_semioctet(uint8_t *sms_vp)
+{
+ unsigned long minutes;
+ minutes = unbcdify(*sms_vp++)*60; /* hours */
+ minutes += unbcdify(*sms_vp++); /* minutes */
+ minutes += unbcdify(*sms_vp++)/60; /* seconds */
+ return minutes;
+}
+
+/* decode validity period. return minutes */
+unsigned long gsm340_validity_period(uint8_t sms_vpf, uint8_t *sms_vp)
+{
+ uint8_t fi; /* functionality indicator */
+
+ switch (sms_vpf) {
+ case GSM340_TP_VPF_RELATIVE:
+ return gsm340_vp_relative(sms_vp);
+ case GSM340_TP_VPF_ABSOLUTE:
+ return gsm340_vp_absolute(sms_vp);
+ case GSM340_TP_VPF_ENHANCED:
+ /* Chapter 9.2.3.12.3 */
+ fi = *sms_vp++;
+ /* ignore additional fi */
+ if (fi & (1<<7)) sms_vp++;
+ /* read validity period format */
+ switch (fi & 0x7) {
+ case 0x0:
+ return gsm340_vp_default(); /* no vpf specified */
+ case 0x1:
+ return gsm340_vp_relative(sms_vp);
+ case 0x2:
+ return gsm340_vp_relative_integer(sms_vp);
+ case 0x3:
+ return gsm340_vp_relative_semioctet(sms_vp);
+ default:
+ /* The GSM spec says that the SC should reject any
+ unsupported and/or undefined values. FIXME */
+ LOGP(DLSMS, LOGL_ERROR,
+ "Reserved enhanced validity period format\n");
+ return gsm340_vp_default();
+ }
+ case GSM340_TP_VPF_NONE:
+ default:
+ return gsm340_vp_default();
+ }
+}
+
+/* determine coding alphabet dependent on GSM 03.38 Section 4 DCS */
+enum sms_alphabet gsm338_get_sms_alphabet(uint8_t dcs)
+{
+ uint8_t cgbits = dcs >> 4;
+ enum sms_alphabet alpha = DCS_NONE;
+
+ if ((cgbits & 0xc) == 0) {
+ if (cgbits & 2) {
+ LOGP(DLSMS, LOGL_NOTICE,
+ "Compressed SMS not supported yet\n");
+ return 0xffffffff;
+ }
+
+ switch ((dcs >> 2)&0x03) {
+ case 0:
+ alpha = DCS_7BIT_DEFAULT;
+ break;
+ case 1:
+ alpha = DCS_8BIT_DATA;
+ break;
+ case 2:
+ alpha = DCS_UCS2;
+ break;
+ }
+ } else if (cgbits == 0xc || cgbits == 0xd)
+ alpha = DCS_7BIT_DEFAULT;
+ else if (cgbits == 0xe)
+ alpha = DCS_UCS2;
+ else if (cgbits == 0xf) {
+ if (dcs & 4)
+ alpha = DCS_8BIT_DATA;
+ else
+ alpha = DCS_7BIT_DEFAULT;
+ }
+
+ return alpha;
+}
+
+/* generate a TPDU address field compliant with 03.40 sec. 9.1.2.5 */
+int gsm340_gen_oa(uint8_t *oa, unsigned int oa_len, uint8_t type,
+ uint8_t plan, const char *number)
+{
+ int len_in_bytes;
+
+ /* prevent buffer overflows */
+ if (strlen(number) > 20)
+ number = "";
+
+// oa[1] = 0xb9; /* networks-specific number, private numbering plan */
+ oa[1] = 0x80 | (type << 4) | plan;
+
+ len_in_bytes = gsm48_encode_bcd_number(oa, oa_len, 1, number);
+
+ /* GSM 03.40 tells us the length is in 'useful semi-octets' */
+ oa[0] = strlen(number) & 0xff;
+
+ return len_in_bytes;
+}
+
+/* Prefix msg with a RP header */
+int gsm411_push_rp_header(struct msgb *msg, uint8_t rp_msg_type,
+ uint8_t rp_msg_ref)
+{
+ struct gsm411_rp_hdr *rp;
+ uint8_t len = msg->len;
+
+ /* GSM 04.11 RP-DATA header */
+ rp = (struct gsm411_rp_hdr *)msgb_push(msg, sizeof(*rp));
+ rp->len = len + 2;
+ rp->msg_type = rp_msg_type;
+ rp->msg_ref = rp_msg_ref; /* FIXME: Choose randomly */
+
+ return 0;
+}
+
+/* Prefix msg with a 04.08/04.11 CP header */
+int gsm411_push_cp_header(struct msgb *msg, uint8_t proto, uint8_t trans,
+ uint8_t msg_type)
+{
+ struct gsm48_hdr *gh;
+
+ gh = (struct gsm48_hdr *) msgb_push(msg, sizeof(*gh));
+ /* Outgoing needs the highest bit set */
+ gh->proto_discr = proto | (trans << 4);
+ gh->msg_type = msg_type;
+
+ return 0;
+}