gprs: Move LLC IE length fix to BSSGP level
This commit moves the fixing code of the length field of the LLC
information element to the BSSGP patching level since that is not a
part of LLC itself.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index b41bedb..d4b5e0e 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -1252,7 +1252,7 @@
}
static void gbprox_patch_llc(struct msgb *msg, uint8_t *llc, size_t llc_len,
- struct gbprox_peer *peer,
+ struct gbprox_peer *peer, int *len_change,
struct gbprox_parse_context *parse_ctx)
{
struct gprs_llc_hdr_parsed ghp = {0};
@@ -1260,7 +1260,6 @@
uint8_t *data;
size_t data_len;
int fcs;
- int len_change = 0;
const char *err_info = NULL;
int err_ctr = -1;
uint32_t tlli = parse_ctx->tlli;
@@ -1311,7 +1310,7 @@
parse_ctx->llc_hdr_parsed = &ghp;
- rc = gbprox_patch_dtap(msg, data, data_len, peer, &len_change, parse_ctx);
+ rc = gbprox_patch_dtap(msg, data, data_len, peer, len_change, parse_ctx);
if (parse_ctx->new_ptmsi &&
(parse_ctx->new_ptmsi | 0xc000) != (tlli | 0xc000) &&
@@ -1325,22 +1324,8 @@
}
if (rc > 0) {
- llc_len += len_change;
- ghp.crc_length += len_change;
-
- /* Fix LLC IE len */
- if (llc[-2] == BSSGP_IE_LLC_PDU && llc[-1] & 0x80) {
- /* most probably a one byte length */
- if (llc_len > 127) {
- err_info = "Cannot increase size";
- err_ctr = GBPROX_PEER_CTR_PATCH_ERR;
- goto patch_error;
- }
- llc[-1] = llc_len | 0x80;
- } else {
- llc[-2] = (llc_len >> 8) & 0x7f;
- llc[-1] = llc_len & 0xff;
- }
+ llc_len += *len_change;
+ ghp.crc_length += *len_change;
/* Fix FCS */
fcs = gprs_llc_fcs(llc, ghp.crc_length);
@@ -1373,6 +1358,8 @@
uint8_t pdu_type;
uint8_t *data;
size_t data_len;
+ const char *err_info = NULL;
+ int err_ctr = -1;
if (!gbcfg.core_mcc && !gbcfg.core_mnc && !gbcfg.core_apn)
return;
@@ -1426,6 +1413,7 @@
uint8_t *llc = (uint8_t *)TLVP_VAL(&tp, BSSGP_IE_LLC_PDU);
size_t llc_len = TLVP_LEN(&tp, BSSGP_IE_LLC_PDU);
struct gbprox_parse_context parse_ctx = {0};
+ int len_change = 0;
parse_ctx.bssgp_tp = &tp;
parse_ctx.bud_hdr = budh;
parse_ctx.tlli = budh ? ntohl(budh->tlli) : 0;
@@ -1436,10 +1424,37 @@
parse_ctx.imsi_len = TLVP_LEN(&tp, BSSGP_IE_IMSI);
}
- gbprox_patch_llc(msg, llc, llc_len, peer, &parse_ctx);
+ gbprox_patch_llc(msg, llc, llc_len, peer, &len_change, &parse_ctx);
+
+ if (len_change) {
+ llc_len += len_change;
+
+ /* Fix LLC IE len */
+ /* TODO: This is a kludge, but the a pointer to the
+ * start of the IE is not available here */
+ if (llc[-2] == BSSGP_IE_LLC_PDU && llc[-1] & 0x80) {
+ /* most probably a one byte length */
+ if (llc_len > 127) {
+ err_info = "Cannot increase size";
+ err_ctr = GBPROX_PEER_CTR_PATCH_ERR;
+ goto patch_error;
+ }
+ llc[-1] = llc_len | 0x80;
+ } else {
+ llc[-2] = (llc_len >> 8) & 0x7f;
+ llc[-1] = llc_len & 0xff;
+ }
+ }
/* Note that the tp struct might contain invalid pointers here
* if the LLC field has changed its size */
}
+ return;
+
+patch_error:
+ OSMO_ASSERT(err_ctr >= 0);
+ rate_ctr_inc(&peer->ctrg->ctr[err_ctr]);
+ LOGP(DGPRS, LOGL_ERROR,
+ "Failed to patch BSSGP message as requested: %s.\n", err_info);
}
/* feed a message down the NS-VC associated with the specified peer */