Add utility to extract datagrams

diff --git a/src/smsutil.c b/src/smsutil.c
index ff7d106..165fa8b 100644 (file)
--- a/src/smsutil.c
+++ b/src/smsutil.c
@@ -1861,3 +1861,73 @@ gboolean sms_extract_concatenation(const struct sms *sms, int *ref_num,
 
        return TRUE;
 }
+
+/*!
+ * Decodes a list of SMSes that contain a datagram.  The list must be
+ * sorted in order of the sequence number.  This function assumes that
+ * all fragments are coded using 8-bit character set.
+ *
+ * Returns a pointer to a newly allocated array or NULL if the
+ * conversion could not be performed
+ */
+unsigned char *sms_decode_datagram(GSList *sms_list, long *out_len)
+{
+       GSList *l;
+       const struct sms *sms;
+       unsigned char *buf;
+       long len = 0;
+
+       for (l = sms_list; l; l = l->next) {
+               guint8 taken = 0;
+               guint8 udl;
+               const guint8 *ud;
+               struct sms_udh_iter iter;
+
+               sms = l->data;
+
+               ud = sms_extract_common(sms, NULL, NULL, &udl, NULL);
+
+               if (!ud)
+                       return NULL;
+
+               /* Note we do this because we must check whether the UDH
+                * is properly formatted.  If not, the entire UDH is ignored
+                */
+               if (sms_udh_iter_init(sms, &iter))
+                       taken = sms_udh_iter_get_udh_length(&iter) + 1;
+
+               len += udl - taken;
+       }
+
+       /* Data is probably in headers we can't understand */
+       if (len == 0)
+               return NULL;
+
+       buf = g_try_new(unsigned char, len);
+
+       if (!buf)
+               return NULL;
+
+       len = 0;
+       for (l = sms_list; l; l = l->next) {
+               guint8 taken = 0;
+               guint8 udl;
+               const guint8 *ud;
+               struct sms_udh_iter iter;
+
+               sms = l->data;
+
+               ud = sms_extract_common(sms, NULL, NULL, &udl, NULL);
+
+               if (sms_udh_iter_init(sms, &iter))
+                       taken = sms_udh_iter_get_udh_length(&iter) + 1;
+
+               memcpy(buf + len, ud + taken, udl - taken);
+               len += udl - taken;
+       }
+
+       if (out_len)
+               *out_len = len;
+
+       return buf;
+}

diff --git a/src/smsutil.h b/src/smsutil.h
index 9b67977..367e914 100644 (file)
--- a/src/smsutil.h
+++ b/src/smsutil.h
@@ -356,4 +356,6 @@ gboolean sms_mwi_dcs_decode(guint8 dcs, enum sms_mwi_type *type,
 gboolean sms_extract_app_port(const struct sms *sms, int *dst, int *src);
 gboolean sms_extract_concatenation(const struct sms *sms, int *ref_num,
                                        int *max_msgs, int *seq_num);
+
+unsigned char *sms_decode_datagram(GSList *sms_list, long *out_len);
 #endif