gsm0808: fix AoIP speech codec element parser/generator
The implementation of the parser/generator for the speech codec
information element slightly wrong, making it impossible to use
it properly.
(See also: 3GPP TS 48.008, 3.2.2.103)
Change-Id: Idabb0f9620659557672e1c6b90c75481192e5c89
diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c
index bdd02e5..60fb91c 100644
--- a/src/gsm/gsm0808_utils.c
+++ b/src/gsm/gsm0808_utils.c
@@ -151,6 +151,32 @@
/* See also 3GPP TS 48.008 3.2.2.103 Speech Codec List */
uint8_t header = 0;
uint8_t *old_tail;
+ bool type_extended;
+
+ /* Note: Extended codec types are codec types that require 8 instead
+ * of 4 bit to fully specify the selected codec. In the following,
+ * we check if we work with an extended type or not. We also check
+ * if the codec type is valid at all. */
+ switch(sc->type) {
+ case GSM0808_SCT_FR1:
+ case GSM0808_SCT_FR2:
+ case GSM0808_SCT_FR3:
+ case GSM0808_SCT_FR4:
+ case GSM0808_SCT_FR5:
+ case GSM0808_SCT_HR1:
+ case GSM0808_SCT_HR3:
+ case GSM0808_SCT_HR4:
+ case GSM0808_SCT_HR6:
+ type_extended = false;
+ break;
+ case GSM0808_SCT_CSD:
+ type_extended = true;
+ break;
+ default:
+ /* Invalid codec type specified */
+ OSMO_ASSERT(false);
+ break;
+ }
old_tail = msg->tail;
@@ -162,20 +188,37 @@
header |= (1 << 5);
if (sc->tf)
header |= (1 << 4);
- if (sc->type_extended) {
+
+ if (type_extended) {
header |= 0x0f;
msgb_put_u8(msg, header);
+ msgb_put_u8(msg, sc->type);
} else {
OSMO_ASSERT(sc->type < 0x0f);
header |= sc->type;
msgb_put_u8(msg, header);
- return (uint8_t) (msg->tail - old_tail);
}
- msgb_put_u8(msg, sc->type);
-
- if (sc->cfg_present)
+ /* Note: Whether a configuration is present or not depends on the
+ * selected codec type. If present, it can either consist of one
+ * or two octets, depending on the codec type */
+ switch (sc->type) {
+ case GSM0808_SCT_FR3:
+ case GSM0808_SCT_HR3:
+ case GSM0808_SCT_HR6:
msgb_put_u16(msg, sc->cfg);
+ break;
+ case GSM0808_SCT_FR4:
+ case GSM0808_SCT_FR5:
+ case GSM0808_SCT_HR4:
+ case GSM0808_SCT_CSD:
+ OSMO_ASSERT((sc->cfg & 0xff00) == 0)
+ msgb_put_u8(msg, (uint8_t) sc->cfg & 0xff);
+ break;
+ default:
+ OSMO_ASSERT(sc->cfg == 0);
+ break;
+ }
return (uint8_t) (msg->tail - old_tail);
}
@@ -244,21 +287,42 @@
if ((header & 0x0F) != 0x0F) {
sc->type = (header & 0x0F);
- return (int)(elem - old_elem);
+ } else {
+ sc->type = *elem;
+ elem++;
+ len--;
}
- sc->type = *elem;
- elem++;
- len--;
-
- sc->type_extended = true;
-
- if (len < 2)
- return (int)(elem - old_elem);
-
- sc->cfg = osmo_load16be(elem);
- elem += 2;
- sc->cfg_present = true;
+ /* Note: Whether a configuration is present or not depends on the
+ * selected codec type. If present, it can either consist of one or
+ * two octets depending on the codec type */
+ switch (sc->type) {
+ case GSM0808_SCT_FR1:
+ case GSM0808_SCT_FR2:
+ case GSM0808_SCT_HR1:
+ break;
+ case GSM0808_SCT_HR4:
+ case GSM0808_SCT_CSD:
+ case GSM0808_SCT_FR4:
+ case GSM0808_SCT_FR5:
+ if (len < 1)
+ return -EINVAL;
+ sc->cfg = *elem;
+ elem++;
+ break;
+ case GSM0808_SCT_FR3:
+ case GSM0808_SCT_HR3:
+ case GSM0808_SCT_HR6:
+ if (len < 2)
+ return -EINVAL;
+ sc->cfg = osmo_load16be(elem);
+ elem += 2;
+ break;
+ default:
+ /* Invalid codec type => malformed speech codec element! */
+ return -EINVAL;
+ break;
+ }
return (int)(elem - old_elem);
}