[osmo-bts PATCH 2/5] moved out the ipa header sanity check in check_oml_msg

[Alvaro Neira Ayuso]

From: Álvaro Neira Ayuso <anayuso at sysmocom.de>

I have split the function check_oml_msg, in two functions. One for
checking if the ipa header is well-formed and in check_oml_msg,
I have removed this code for using in the future the function
check_oml_msg for passing a sanity check to oml message without
ipa header.

Signed-off-by: Alvaro Neira Ayuso <anayuso at sysmocom.de>
---
 src/osmo-bts-sysmo/main.c  |   11 +++++++++-
 src/osmo-bts-sysmo/utils.c |   50 ++++++++++++++++++++++++--------------------
 src/osmo-bts-sysmo/utils.h |    1 +
 3 files changed, 38 insertions(+), 24 deletions(-)

diff --git a/src/osmo-bts-sysmo/main.c b/src/osmo-bts-sysmo/main.c
index bd6a181..797f174 100644
--- a/src/osmo-bts-sysmo/main.c
+++ b/src/osmo-bts-sysmo/main.c
@@ -317,7 +317,16 @@ static int read_sock(struct osmo_fd *fd, unsigned int what)
 
 	msgb_put(msg, rc);
 
-	if (check_oml_msg(msg) < 0) {
+	rc = check_ipa_header(msg);
+	if (rc < 0) {
+		LOGP(DL1C, LOGL_ERROR, "Malformed receive message: Ipa hdr\n");
+		goto err;
+	}
+
+	msgb_pull(msg, sizeof(struct ipaccess_head));
+
+	rc = check_oml_msg(msg);
+	if (rc < 0) {
 		LOGP(DL1C, LOGL_ERROR, "Malformed receive message\n");
 		goto err;
 	}
diff --git a/src/osmo-bts-sysmo/utils.c b/src/osmo-bts-sysmo/utils.c
index 2da1228..1fa5796 100644
--- a/src/osmo-bts-sysmo/utils.c
+++ b/src/osmo-bts-sysmo/utils.c
@@ -181,33 +181,10 @@ void prepend_oml_ipa_header(struct msgb *msg)
 
 int check_oml_msg(struct msgb *msg)
 {
-	struct ipaccess_head *hh;
 	struct abis_om_hdr *omh;
 	int abis_oml_hdr_len;
 	char label_id[255];
 
-	if (msg->len < sizeof(struct ipaccess_head)) {
-		LOGP(DL1C, LOGL_ERROR, "Ipa header insufficient space %d %d\n",
-					msg->len, sizeof(struct ipaccess_head));
-		return -1;
-	}
-
-	hh = (struct ipaccess_head *)msg->data;
-
-	if (hh->proto != IPAC_PROTO_OML) {
-		LOGP(DL1C, LOGL_ERROR, "Incorrect ipa header protocol %x %x\n",
-		     hh->proto, IPAC_PROTO_OML);
-		return -1;
-	}
-
-	if (ntohs(hh->len) != msg->len - sizeof(struct ipaccess_head)) {
-		LOGP(DL1C, LOGL_ERROR, "Incorrect ipa header msg size %d %d\n",
-		     ntohs(hh->len), msg->len - sizeof(struct ipaccess_head));
-		return -1;
-	}
-
-	msgb_pull(msg, sizeof(struct ipaccess_head));
-
 	abis_oml_hdr_len = sizeof(struct abis_om_hdr);
 
 	if (msg->len < abis_oml_hdr_len) {
@@ -287,6 +264,33 @@ int check_oml_msg(struct msgb *msg)
 	return 0;
 }
 
+int check_ipa_header(struct msgb *msg)
+{
+	struct ipaccess_head *hh;
+
+	if (msg->len < sizeof(struct ipaccess_head)) {
+		LOGP(DL1C, LOGL_ERROR, "Ipa header insufficient space %d %d\n",
+					msg->len, sizeof(struct ipaccess_head));
+		return -1;
+	}
+
+	hh = (struct ipaccess_head *)msg->data;
+
+	if (hh->proto != IPAC_PROTO_OML) {
+		LOGP(DL1C, LOGL_ERROR, "Incorrect ipa header protocol %x %x\n",
+		     hh->proto, IPAC_PROTO_OML);
+		return -1;
+	}
+
+	if (ntohs(hh->len) != msg->len - sizeof(struct ipaccess_head)) {
+		LOGP(DL1C, LOGL_ERROR, "Incorrect ipa header msg size %d %d\n",
+		     ntohs(hh->len), msg->len - sizeof(struct ipaccess_head));
+		return -1;
+	}
+
+	return 0;
+}
+
 int add_manufacturer_id_label(struct msgb *msg, int manuf_type_id)
 {
 	uint8_t *manuf;
diff --git a/src/osmo-bts-sysmo/utils.h b/src/osmo-bts-sysmo/utils.h
index 85a5e88..4f2293a 100644
--- a/src/osmo-bts-sysmo/utils.h
+++ b/src/osmo-bts-sysmo/utils.h
@@ -29,4 +29,5 @@ int add_manufacturer_id_label(struct msgb *msg, int manuf_type_id);
 void prepend_oml_ipa_header(struct msgb *msg);
 
 int check_oml_msg(struct msgb *msg);
+int check_ipa_header(struct msgb *msg);
 #endif
-- 
1.7.10.4