gprs: Use struct to pass context information
Add a struct containing context information from the parts of the
message that have been parsed already. A pointer to this (temporary)
struct is passed to parse/patch functions.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index 412b215..5fcd25a 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -519,6 +519,21 @@
return -1;
}
+struct gbprox_parse_context {
+ /* Pointer to protocol specific parts */
+ struct gsm48_hdr *g48_hdr;
+ struct gprs_llc_hdr_parsed *llc_hdr_parsed;
+ struct tlv_parsed *bssgp_tp;
+ struct bssgp_ud_hdr *bud_hdr;
+
+ /* Extracted information */
+ int to_bss;
+ uint32_t tlli;
+ const uint8_t *imsi;
+ size_t imsi_len;
+ uint32_t new_ptmsi;
+};
+
struct gbprox_tlli_info {
struct llist_head list;
@@ -939,7 +954,8 @@
static int gbprox_patch_gmm_attach_req(struct msgb *msg,
uint8_t *data, size_t data_len,
struct gbprox_peer *peer,
- int to_bss, int *len_change)
+ int *len_change,
+ struct gbprox_parse_context *parse_ctx)
{
uint8_t *value;
size_t value_len;
@@ -964,15 +980,15 @@
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
- gbprox_patch_raid(value, peer, to_bss, "LLC/ATTACH_REQ");
+ gbprox_patch_raid(value, peer, parse_ctx->to_bss, "LLC/ATTACH_REQ");
return 1;
}
static int gbprox_patch_gmm_attach_ack(struct msgb *msg,
uint8_t *data, size_t data_len,
- struct gbprox_peer *peer,
- int to_bss, int *len_change)
+ struct gbprox_peer *peer, int *len_change,
+ struct gbprox_parse_context *parse_ctx)
{
uint8_t *value;
@@ -986,15 +1002,15 @@
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
- gbprox_patch_raid(value, peer, to_bss, "LLC/ATTACH_ACK");
+ gbprox_patch_raid(value, peer, parse_ctx->to_bss, "LLC/ATTACH_ACK");
return 1;
}
static int gbprox_patch_gmm_ra_upd_req(struct msgb *msg,
uint8_t *data, size_t data_len,
- struct gbprox_peer *peer,
- int to_bss, int *len_change)
+ struct gbprox_peer *peer, int *len_change,
+ struct gbprox_parse_context *parse_ctx)
{
uint8_t *value;
@@ -1005,15 +1021,15 @@
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
- gbprox_patch_raid(value, peer, to_bss, "LLC/RA_UPD_REQ");
+ gbprox_patch_raid(value, peer, parse_ctx->to_bss, "LLC/RA_UPD_REQ");
return 1;
}
static int gbprox_patch_gmm_ra_upd_ack(struct msgb *msg,
uint8_t *data, size_t data_len,
- struct gbprox_peer *peer,
- int to_bss, int *len_change)
+ struct gbprox_peer *peer, int *len_change,
+ struct gbprox_parse_context *parse_ctx)
{
uint8_t *value;
@@ -1025,7 +1041,7 @@
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
- gbprox_patch_raid(value, peer, to_bss, "LLC/RA_UPD_ACK");
+ gbprox_patch_raid(value, peer, parse_ctx->to_bss, "LLC/RA_UPD_ACK");
return 1;
@@ -1034,7 +1050,8 @@
static int gbprox_patch_gmm_ptmsi_reall_cmd(struct msgb *msg,
uint8_t *data, size_t data_len,
struct gbprox_peer *peer,
- int to_bss, int *len_change)
+ int *len_change,
+ struct gbprox_parse_context *parse_ctx)
{
uint8_t *value;
size_t value_len;
@@ -1047,15 +1064,15 @@
if (v_fixed_shift(&data, &data_len, 6, &value) <= 0)
return 0;
- gbprox_patch_raid(value, peer, to_bss, "LLC/PTMSI_REALL_CMD");
+ gbprox_patch_raid(value, peer, parse_ctx->to_bss, "LLC/PTMSI_REALL_CMD");
return 1;
}
static int gbprox_patch_gsm_act_pdp_req(struct msgb *msg,
uint8_t *data, size_t data_len,
- struct gbprox_peer *peer,
- int to_bss, int *len_change)
+ struct gbprox_peer *peer, int *len_change,
+ struct gbprox_parse_context *parse_ctx)
{
size_t new_len;
ssize_t old_len;
@@ -1122,8 +1139,8 @@
}
static int gbprox_patch_dtap(struct msgb *msg, uint8_t *data, size_t data_len,
- struct gbprox_peer *peer, int to_bss,
- uint32_t tlli, int *len_change)
+ struct gbprox_peer *peer, int *len_change,
+ struct gbprox_parse_context *parse_ctx)
{
struct gsm48_hdr *g48h;
@@ -1140,13 +1157,13 @@
case GSM48_MT_GMM_ATTACH_REQ:
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_ATTACH_REQS]);
return gbprox_patch_gmm_attach_req(msg, data, data_len,
- peer, to_bss, len_change);
+ peer, len_change, parse_ctx);
case GSM48_MT_GMM_ATTACH_ACK:
if (!patching_is_enabled(GBPROX_PATCH_LLC_ATTACH))
break;
return gbprox_patch_gmm_attach_ack(msg, data, data_len,
- peer, to_bss, len_change);
+ peer, len_change, parse_ctx);
case GSM48_MT_GMM_ATTACH_REJ:
rate_ctr_inc(&peer->ctrg->ctr[GBPROX_PEER_CTR_ATTACH_REJS]);
@@ -1156,33 +1173,34 @@
if (!patching_is_enabled(GBPROX_PATCH_LLC_GMM))
break;
return gbprox_patch_gmm_ra_upd_req(msg, data, data_len,
- peer, to_bss, len_change);
+ peer, len_change, parse_ctx);
case GSM48_MT_GMM_RA_UPD_ACK:
if (!patching_is_enabled(GBPROX_PATCH_LLC_GMM))
break;
return gbprox_patch_gmm_ra_upd_ack(msg, data, data_len,
- peer, to_bss, len_change);
+ peer, len_change, parse_ctx);
case GSM48_MT_GMM_PTMSI_REALL_CMD:
if (!patching_is_enabled(GBPROX_PATCH_LLC_GMM))
break;
return gbprox_patch_gmm_ptmsi_reall_cmd(msg, data, data_len,
- peer, to_bss, len_change);
+ peer, len_change,
+ parse_ctx);
case GSM48_MT_GSM_ACT_PDP_REQ:
if (!patching_is_enabled(GBPROX_PATCH_LLC_GSM))
break;
if (gbcfg.core_apn == NULL)
break;
- if (!gbprox_check_tlli(peer, tlli))
+ if (!gbprox_check_tlli(peer, parse_ctx->tlli))
break;
return gbprox_patch_gsm_act_pdp_req(msg, data, data_len,
- peer, to_bss, len_change);
+ peer, len_change, parse_ctx);
case GSM48_MT_GMM_DETACH_ACK:
case GSM48_MT_GMM_DETACH_REQ:
- gbprox_unregister_tlli(peer, tlli);
+ gbprox_unregister_tlli(peer, parse_ctx->tlli);
break;
default:
@@ -1193,9 +1211,8 @@
}
static void gbprox_patch_llc(struct msgb *msg, uint8_t *llc, size_t llc_len,
- struct gbprox_peer *peer, int to_bss,
- struct bssgp_ud_hdr *budh,
- struct tlv_parsed *bssgp_tp)
+ struct gbprox_peer *peer,
+ struct gbprox_parse_context *parse_ctx)
{
struct gprs_llc_hdr_parsed ghp = {0};
int rc;
@@ -1205,7 +1222,7 @@
int len_change = 0;
const char *err_info = NULL;
int err_ctr = -1;
- uint32_t tlli = budh ? ntohl(budh->tlli) : 0;
+ uint32_t tlli = parse_ctx->tlli;
/* parse LLC */
rc = gprs_llc_hdr_parse(&ghp, llc, llc_len);
@@ -1225,11 +1242,9 @@
if (ghp.sapi != GPRS_SAPI_GMM)
return;
- if (gbcfg.core_apn && to_bss && tlli &&
- TLVP_PRESENT(bssgp_tp, BSSGP_IE_IMSI))
+ if (gbcfg.core_apn && parse_ctx->to_bss && tlli && parse_ctx->imsi)
gbprox_register_tlli(peer, tlli,
- TLVP_VAL(bssgp_tp, BSSGP_IE_IMSI),
- TLVP_LEN(bssgp_tp, BSSGP_IE_IMSI));
+ parse_ctx->imsi, parse_ctx->imsi_len);
if (ghp.cmd != GPRS_LLC_UI)
return;
@@ -1253,8 +1268,9 @@
data = ghp.data;
data_len = ghp.data_len;
- rc = gbprox_patch_dtap(msg, data, data_len, peer, to_bss,
- tlli, &len_change);
+ parse_ctx->llc_hdr_parsed = &ghp;
+
+ rc = gbprox_patch_dtap(msg, data, data_len, peer, &len_change, parse_ctx);
if (rc > 0) {
llc_len += len_change;
@@ -1357,7 +1373,18 @@
patching_is_enabled(GBPROX_PATCH_LLC_ATTACH_REQ)) {
uint8_t *llc = (uint8_t *)TLVP_VAL(&tp, BSSGP_IE_LLC_PDU);
size_t llc_len = TLVP_LEN(&tp, BSSGP_IE_LLC_PDU);
- gbprox_patch_llc(msg, llc, llc_len, peer, to_bss, budh, &tp);
+ struct gbprox_parse_context parse_ctx = {0};
+ parse_ctx.bssgp_tp = &tp;
+ parse_ctx.bud_hdr = budh;
+ parse_ctx.tlli = budh ? ntohl(budh->tlli) : 0;
+ parse_ctx.to_bss = to_bss;
+
+ if (TLVP_PRESENT(&tp, BSSGP_IE_IMSI)) {
+ parse_ctx.imsi = TLVP_VAL(&tp, BSSGP_IE_IMSI);
+ parse_ctx.imsi_len = TLVP_LEN(&tp, BSSGP_IE_IMSI);
+ }
+
+ gbprox_patch_llc(msg, llc, llc_len, peer, &parse_ctx);
/* Note that the tp struct might contain invalid pointers here
* if the LLC field has changed its size */
}