diff options
Diffstat (limited to 'openbsc/src')
-rw-r--r-- | openbsc/src/nat/bsc_nat_utils.c | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/openbsc/src/nat/bsc_nat_utils.c b/openbsc/src/nat/bsc_nat_utils.c index 674de4184..dc18cffec 100644 --- a/openbsc/src/nat/bsc_nat_utils.c +++ b/openbsc/src/nat/bsc_nat_utils.c @@ -549,6 +549,25 @@ int bsc_nat_filter_sccp_cr(struct bsc_connection *bsc, struct msgb *msg, } } +struct gsm48_hdr *bsc_unpack_dtap(struct bsc_nat_parsed *parsed, + struct msgb *msg, uint32_t *len) +{ + /* gsm_type is actually the size of the dtap */ + *len = parsed->gsm_type; + if (*len < msgb_l3len(msg) - 3) { + LOGP(DNAT, LOGL_ERROR, "Not enough space for DTAP.\n"); + return NULL; + } + + if (*len < sizeof(struct gsm48_hdr)) { + LOGP(DNAT, LOGL_ERROR, "GSM48 header does not fit.\n"); + return NULL; + } + + msg->l4h = &msg->l3h[3]; + return (struct gsm48_hdr *) msg->l4h; +} + int bsc_nat_filter_dt(struct bsc_connection *bsc, struct msgb *msg, struct sccp_connections *con, struct bsc_nat_parsed *parsed) { @@ -563,20 +582,9 @@ int bsc_nat_filter_dt(struct bsc_connection *bsc, struct msgb *msg, if (parsed->bssap != BSSAP_MSG_DTAP) return 0; - /* gsm_type is actually the size of the dtap */ - len = parsed->gsm_type; - if (len < msgb_l3len(msg) - 3) { - LOGP(DNAT, LOGL_ERROR, "Not enough space for DTAP.\n"); + hdr48 = bsc_unpack_dtap(parsed, msg, &len); + if (!hdr48) return -1; - } - - if (len < sizeof(*hdr48)) { - LOGP(DNAT, LOGL_ERROR, "GSM48 header does not fit.\n"); - return -1; - } - - msg->l4h = &msg->l3h[3]; - hdr48 = (struct gsm48_hdr *) msg->l4h; msg_type = hdr48->msg_type & 0xbf; if (hdr48->proto_discr == GSM48_PDISC_MM && |