ipa: add osmo_ipa_process_msg and remove osmo_ipa_recv_msg

This patch removes osmo_ipa_recv_msg, it performs two syscall invocations
and it's stream generic. Now we use the specific receival function
we want to use (no matter if stream or datagram based) and then we
call osmo_ipa_process_msg to check that the IPA message correct.

6 files changed, 39 insertions, 37 deletions

diff --git a/examples/ipa-stream-client.c b/examples/ipa-stream-client.c
index b771fa3..db1ce62 100644
--- a/examples/ipa-stream-client.c
+++ b/examples/ipa-stream-client.c
@@ -96,7 +96,6 @@ static int connect_cb(struct osmo_stream_cli *conn)
 static int read_cb(struct osmo_stream_cli *conn)
 {
 	struct msgb *msg;
-	struct osmo_fd *ofd = osmo_stream_cli_get_ofd(conn);
 
 	LOGP(DIPATEST, LOGL_DEBUG, "received message from stream\n");
 
@@ -105,10 +104,14 @@ static int read_cb(struct osmo_stream_cli *conn)
 		LOGP(DIPATEST, LOGL_ERROR, "cannot allocate message\n");
 		return 0;
 	}
-	if (osmo_ipa_msg_recv(ofd->fd, msg) <= 0) {
+	if (osmo_stream_cli_recv(conn, msg) <= 0) {
 		LOGP(DIPATEST, LOGL_ERROR, "cannot receive message\n");
 		return 0;
 	}
+	if (osmo_ipa_process_msg(msg) < 0) {
+		LOGP(DIPATEST, LOGL_ERROR, "bad IPA message\n");
+		return 0;
+	}
 
 	int num;
 	struct msg_sent *cur, *tmp, *found = NULL;
diff --git a/examples/ipa-stream-server.c b/examples/ipa-stream-server.c
index 69e0280..c370d5f 100644
--- a/examples/ipa-stream-server.c
+++ b/examples/ipa-stream-server.c
@@ -46,7 +46,6 @@ void sighandler(int foo)
 int read_cb(struct osmo_stream_srv *conn)
 {
 	struct msgb *msg;
-	struct osmo_fd *ofd = osmo_stream_srv_get_ofd(conn);
 
 	LOGP(DSTREAMTEST, LOGL_DEBUG, "received message from stream\n");
 
@@ -55,12 +54,18 @@ int read_cb(struct osmo_stream_srv *conn)
 		LOGP(DSTREAMTEST, LOGL_ERROR, "cannot allocate message\n");
 		return 0;
 	}
-	if (osmo_ipa_msg_recv(ofd->fd, msg) <= 0) {
+	if (osmo_stream_srv_recv(conn, msg) <= 0) {
 		LOGP(DSTREAMTEST, LOGL_ERROR, "cannot receive message\n");
 		osmo_stream_srv_destroy(conn);
 		msgb_free(msg);
 		return 0;
 	}
+	if (osmo_ipa_process_msg(msg) < 0) {
+		LOGP(DSTREAMTEST, LOGL_ERROR, "Bad IPA message\n");
+		msgb_free(msg);
+		return 0;
+	}
+
 	osmo_stream_srv_send(conn, msg);
 	return 0;
 }
diff --git a/include/osmocom/netif/ipa.h b/include/osmocom/netif/ipa.h
index 5c815cd..ea06c22 100644
--- a/include/osmocom/netif/ipa.h
+++ b/include/osmocom/netif/ipa.h
@@ -47,7 +47,8 @@ enum ipaccess_id_tags {
 
 struct msgb *osmo_ipa_msg_alloc(int headroom);
 void osmo_ipa_msg_push_header(struct msgb *msg, uint8_t proto);
-int osmo_ipa_msg_recv(int fd, struct msgb *msg);
+
+int osmo_ipa_process_msg(struct msgb *msg);
 
 struct ipaccess_unit {
 	uint16_t site_id;
diff --git a/src/channel/abis/ipa_stream_client.c b/src/channel/abis/ipa_stream_client.c
index e6565c4..5745e2a 100644
--- a/src/channel/abis/ipa_stream_client.c
+++ b/src/channel/abis/ipa_stream_client.c
@@ -288,7 +288,6 @@ static int read_cb(struct osmo_stream_cli *conn, int type)
 {
 	int ret;
 	struct msgb *msg;
-	struct osmo_fd *ofd = osmo_stream_cli_get_ofd(conn);
 	struct osmo_chan *chan = osmo_stream_cli_get_data(conn);
 	struct chan_abis_ipa_cli *s;
 	struct ipa_head *hh;
@@ -300,8 +299,7 @@ static int read_cb(struct osmo_stream_cli *conn, int type)
 		LOGP(DLINP, LOGL_ERROR, "cannot allocate message\n");
 		return 0;
 	}
-	/* XXX replace with generic stream reader */
-	ret = osmo_ipa_msg_recv(ofd->fd, msg);
+	ret = osmo_stream_cli_recv(conn, msg);
 	if (ret < 0) {
 		LOGP(DLINP, LOGL_ERROR, "cannot receive message\n");
 		msgb_free(msg);
@@ -314,6 +312,12 @@ static int read_cb(struct osmo_stream_cli *conn, int type)
 		return 0;
 	}
 
+	if (osmo_ipa_process_msg(msg) < 0) {
+		LOGP(DLINP, LOGL_ERROR, "Bad IPA message\n");
+		msgb_free(msg);
+		return -EIO;
+	}
+
 	hh = (struct ipa_head *) msg->data;
 	if (hh->proto == IPAC_PROTO_IPACCESS) {
 		abis_ipa_cli_rcvmsg(chan, conn, msg, type);
diff --git a/src/channel/abis/ipa_stream_server.c b/src/channel/abis/ipa_stream_server.c
index a47b0f6..21a82f8 100644
--- a/src/channel/abis/ipa_stream_server.c
+++ b/src/channel/abis/ipa_stream_server.c
@@ -341,7 +341,6 @@ static int read_cb(struct osmo_stream_srv *conn, int type)
 {
 	int ret;
 	struct msgb *msg;
-	struct osmo_fd *ofd = osmo_stream_srv_get_ofd(conn);
 	struct osmo_ipa_unit *unit = osmo_stream_srv_get_data(conn);
 	struct chan_abis_ipa_srv_conn *inst;
 	struct ipa_head *hh;
@@ -353,7 +352,7 @@ static int read_cb(struct osmo_stream_srv *conn, int type)
 		LOGP(DLINP, LOGL_ERROR, "cannot allocate message\n");
 		return 0;
 	}
-	ret = osmo_ipa_msg_recv(ofd->fd, msg);
+	ret = osmo_stream_srv_recv(conn, msg);
 	if (ret < 0) {
 		LOGP(DLINP, LOGL_ERROR, "cannot receive message\n");
 		msgb_free(msg);
@@ -369,7 +368,11 @@ static int read_cb(struct osmo_stream_srv *conn, int type)
 
 		return 0;
 	}
-	/* XXX: missing IPA message validation */
+	ret = osmo_ipa_process_msg(msg);
+	if (ret < 0) {
+		LOGP(DLINP, LOGL_ERROR, "invalid IPA message\n");
+		msgb_free(msg);
+	}
 
 	hh = (struct ipa_head *) msg->data;
 	if (hh->proto == IPAC_PROTO_IPACCESS) {
diff --git a/src/ipa.c b/src/ipa.c
index 955ae84..e5305cf 100644
--- a/src/ipa.c
+++ b/src/ipa.c
@@ -88,41 +88,27 @@ void osmo_ipa_msg_push_header(struct msgb *msg, uint8_t proto)
 	hh->len = htons(msgb_l2len(msg));
 }
 
-int osmo_ipa_msg_recv(int fd, struct msgb *msg)
+int osmo_ipa_process_msg(struct msgb *msg)
 {
 	struct ipa_head *hh;
-	int len, ret;
+	int len;
 
-	/* first read our 3-byte header */
-	hh = (struct ipa_head *) msg->data;
-	ret = recv(fd, msg->data, sizeof(*hh), 0);
-	if (ret <= 0) {
-		return ret;
-	} else if (ret != sizeof(*hh)) {
-		LOGP(DLINP, LOGL_ERROR, "too small message received\n");
+	if (msg->len < sizeof(struct ipa_head)) {
+		LOGP(DLINP, LOGL_ERROR, "too small IPA message\n");
 		return -EIO;
 	}
-	msgb_put(msg, ret);
-
-	/* then read the length as specified in header */
-	msg->l2h = msg->data + sizeof(*hh);
-	len = ntohs(hh->len);
+	hh = (struct ipa_head *) msg->data;
 
-	if (len < 0 || IPA_ALLOC_SIZE < len + sizeof(*hh)) {
-		LOGP(DLINP, LOGL_ERROR, "bad message length of %d bytes, "
-					"received %d bytes\n", len, ret);
+	len = sizeof(struct ipa_head) + ntohs(hh->len);
+	if (len > msg->len) {
+		LOGP(DLINP, LOGL_ERROR, "bad IPA message header "
+					"hdrlen=%u < datalen=%u\n",
+					len, msg->len);
 		return -EIO;
 	}
+	msg->l2h = msg->data + sizeof(*hh);
 
-	ret = recv(fd, msg->l2h, len, 0);
-	if (ret <= 0) {
-		return ret;
-	} else if (ret < len) {
-		LOGP(DLINP, LOGL_ERROR, "trunked message received\n");
-		return -EIO;
-	}
-	msgb_put(msg, ret);
-	return ret;
+	return 0;
 }
 
 int osmo_ipa_idtag_parse(struct tlv_parsed *dec, unsigned char *buf, int len)