cbsp: Fix endless loop iteration when decoding cell list IEs
The CBSP code assumed that gsm0808_decode_cell_id_u() would return
the number of bytes it has consumed/parsed. But it actually always
returns '0', whcih makes us run in an endless loop :(
Change-Id: I5758af4ec11a827d4b888a3a16c4ec22de90a7d6
diff --git a/src/gsm/cbsp.c b/src/gsm/cbsp.c
index 84b9235..c13be61 100644
--- a/src/gsm/cbsp.c
+++ b/src/gsm/cbsp.c
@@ -515,7 +515,7 @@
osmo_cbsp_errstr = "cell list: error decoding cell_id_union";
return rc;
}
- cur += rc;
+ cur += gsm0808_cell_id_size(cl->id_discr);
llist_add_tail(&ent->list, &cl->list);
}
return 0;
@@ -538,7 +538,7 @@
osmo_cbsp_errstr = "fail list: error decoding cell_id_union";
return rc;
}
- cur += rc;
+ cur += gsm0808_cell_id_size(ent->id_discr);
ent->cause = *cur++;
llist_add_tail(&ent->list, fl);
}
@@ -562,7 +562,7 @@
osmo_cbsp_errstr = "load list: error decoding cell_id_union";
return rc;
}
- cur += rc;
+ cur += gsm0808_cell_id_size(ll->id_discr);
if (cur + 2 > buf + len) {
talloc_free(ent);
osmo_cbsp_errstr = "load list: truncated IE";
@@ -592,7 +592,7 @@
osmo_cbsp_errstr = "completed list: error decoding cell_id_union";
return rc;
}
- cur += rc;
+ cur += gsm0808_cell_id_size(cl->id_discr);
if (cur + 3 > buf + len) {
talloc_free(ent);
osmo_cbsp_errstr = "completed list: truncated IE";
diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c
index 364a04f..7416d8f 100644
--- a/src/gsm/gsm0808_utils.c
+++ b/src/gsm/gsm0808_utils.c
@@ -767,6 +767,27 @@
return (int)(elem - old_elem);
}
+/* Return the size of the value part of a cell identifier of given type */
+int gsm0808_cell_id_size(enum CELL_IDENT discr)
+{
+ switch (discr) {
+ case CELL_IDENT_WHOLE_GLOBAL:
+ return 7;
+ case CELL_IDENT_LAC_AND_CI:
+ return 4;
+ case CELL_IDENT_CI:
+ return 2;
+ case CELL_IDENT_LAI_AND_LAC:
+ return 5;
+ case CELL_IDENT_LAC:
+ return 2;
+ case CELL_IDENT_BSS:
+ case CELL_IDENT_NO_CELL:
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
/*! Decode a single GSM 08.08 Cell ID list element payload
* \param[out] out caller-provided output union
* \param[in] discr Cell ID discriminator describing type to be decoded