osmo-trx-ipc

This adds a IPC backend that uses shared memory interface
to communicate with (proprietary) devices.

Requires config file option
dev-args ipc_msock=/path/to/socket
to specify the master socket the ipc backend should connect to.

If UHD is avaialble the ipc-driver-test tool can be used to test the
backend with a uhd device, this was so far only tested with a b2xx.

Change-Id: Ice63d3499026293ade8aad675ff7a883bcdd5756

1 files changed, 259 insertions, 0 deletions

diff --git a/Transceiver52M/device/ipc/ipc_chan.c b/Transceiver52M/device/ipc/ipc_chan.c
new file mode 100644
index 0000000..9e35fb2
--- /dev/null
+++ b/Transceiver52M/device/ipc/ipc_chan.c
@@ -0,0 +1,259 @@
+/*
+* Copyright 2020 sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+* Author: Pau Espin Pedrol <pespin@sysmocom.de>
+*
+* SPDX-License-Identifier: 0BSD
+*
+* Permission to use, copy, modify, and/or distribute this software for any purpose
+* with or without fee is hereby granted.THE SOFTWARE IS PROVIDED "AS IS" AND THE
+* AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR
+* BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+* CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE
+* USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <inttypes.h>
+#include <sys/mman.h>
+#include <sys/stat.h> /* For mode constants */
+#include <fcntl.h> /* For O_* constants */
+
+#include <debug.h>
+#include <osmocom/core/application.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/timer.h>
+
+#include "shm.h"
+#include "ipc-driver-test.h"
+#include "ipc_chan.h"
+#include "ipc_sock.h"
+
+static int ipc_chan_rx(uint8_t msg_type, struct ipc_sk_chan_if *ipc_prim, uint8_t chan_nr)
+{
+	int rc = 0;
+
+	switch (msg_type) {
+	case IPC_IF_MSG_START_REQ:
+		rc = ipc_rx_chan_start_req(&ipc_prim->u.start_req, chan_nr);
+		break;
+	case IPC_IF_MSG_STOP_REQ:
+		rc = ipc_rx_chan_stop_req(&ipc_prim->u.stop_req, chan_nr);
+		break;
+	case IPC_IF_MSG_SETGAIN_REQ:
+		rc = ipc_rx_chan_setgain_req(&ipc_prim->u.set_gain_req, chan_nr);
+		break;
+	case IPC_IF_MSG_SETFREQ_REQ:
+		rc = ipc_rx_chan_setfreq_req(&ipc_prim->u.set_freq_req, chan_nr);
+		break;
+	case IPC_IF_MSG_SETTXATTN_REQ:
+		rc = ipc_rx_chan_settxatten_req(&ipc_prim->u.txatten_req, chan_nr);
+		break;
+	default:
+		LOGP(DDEV, LOGL_ERROR, "Received unknown IPC msg type 0x%02x on chan %d\n", msg_type, chan_nr);
+		rc = -EINVAL;
+	}
+
+	return rc;
+}
+
+static int ipc_chan_sock_read(struct osmo_fd *bfd)
+{
+	struct ipc_sock_state *state = (struct ipc_sock_state *)bfd->data;
+	struct ipc_sk_chan_if *ipc_prim;
+	struct msgb *msg;
+	int rc;
+
+	msg = msgb_alloc(sizeof(*ipc_prim) + 1000, "ipc_chan_sock_rx");
+	if (!msg)
+		return -ENOMEM;
+
+	ipc_prim = (struct ipc_sk_chan_if *)msg->tail;
+
+	rc = recv(bfd->fd, msg->tail, msgb_tailroom(msg), 0);
+	if (rc == 0)
+		goto close;
+
+	if (rc < 0) {
+		if (errno == EAGAIN) {
+			msgb_free(msg);
+			return 0;
+		}
+		goto close;
+	}
+
+	if (rc < (int)sizeof(*ipc_prim)) {
+		LOGP(DDEV, LOGL_ERROR,
+		     "Received %d bytes on Unix Socket, but primitive size "
+		     "is %zu, discarding\n",
+		     rc, sizeof(*ipc_prim));
+		msgb_free(msg);
+		return 0;
+	}
+
+	rc = ipc_chan_rx(ipc_prim->msg_type, ipc_prim, bfd->priv_nr);
+
+	/* as we always synchronously process the message in IPC_rx() and
+	 * its callbacks, we can free the message here. */
+	msgb_free(msg);
+
+	return rc;
+
+close:
+	msgb_free(msg);
+	ipc_sock_close(state);
+	return -1;
+}
+
+int ipc_chan_sock_send(struct msgb *msg, uint8_t chan_nr)
+{
+	struct ipc_sock_state *state = global_ctrl_socks[chan_nr];
+	struct osmo_fd *conn_bfd;
+
+	if (!state)
+		return -EINVAL;
+
+	if (!state) {
+		LOGP(DDEV, LOGL_INFO,
+		     "IPC socket not created, "
+		     "dropping message\n");
+		msgb_free(msg);
+		return -EINVAL;
+	}
+	conn_bfd = &state->conn_bfd;
+	if (conn_bfd->fd <= 0) {
+		LOGP(DDEV, LOGL_NOTICE,
+		     "IPC socket not connected, "
+		     "dropping message\n");
+		msgb_free(msg);
+		return -EIO;
+	}
+	msgb_enqueue(&state->upqueue, msg);
+	conn_bfd->when |= BSC_FD_WRITE;
+
+	return 0;
+}
+
+static int ipc_chan_sock_write(struct osmo_fd *bfd)
+{
+	struct ipc_sock_state *state = (struct ipc_sock_state *)bfd->data;
+	int rc;
+
+	while (!llist_empty(&state->upqueue)) {
+		struct msgb *msg, *msg2;
+		struct ipc_sk_chan_if *ipc_prim;
+
+		/* peek at the beginning of the queue */
+		msg = llist_entry(state->upqueue.next, struct msgb, list);
+		ipc_prim = (struct ipc_sk_chan_if *)msg->data;
+
+		bfd->when &= ~BSC_FD_WRITE;
+
+		/* bug hunter 8-): maybe someone forgot msgb_put(...) ? */
+		if (!msgb_length(msg)) {
+			LOGP(DDEV, LOGL_ERROR,
+			     "message type (%d) with ZERO "
+			     "bytes!\n",
+			     ipc_prim->msg_type);
+			goto dontsend;
+		}
+
+		/* try to send it over the socket */
+		rc = write(bfd->fd, msgb_data(msg), msgb_length(msg));
+		if (rc == 0)
+			goto close;
+		if (rc < 0) {
+			if (errno == EAGAIN) {
+				bfd->when |= BSC_FD_WRITE;
+				break;
+			}
+			goto close;
+		}
+
+	dontsend:
+		/* _after_ we send it, we can dequeue */
+		msg2 = msgb_dequeue(&state->upqueue);
+		assert(msg == msg2);
+		msgb_free(msg);
+	}
+	return 0;
+
+close:
+	ipc_sock_close(state);
+	return -1;
+}
+
+static int ipc_chan_sock_cb(struct osmo_fd *bfd, unsigned int flags)
+{
+	int rc = 0;
+
+	if (flags & BSC_FD_READ)
+		rc = ipc_chan_sock_read(bfd);
+	if (rc < 0)
+		return rc;
+
+	if (flags & BSC_FD_WRITE)
+		rc = ipc_chan_sock_write(bfd);
+
+	return rc;
+}
+
+int ipc_chan_sock_accept(struct osmo_fd *bfd, unsigned int flags)
+{
+	struct ipc_sock_state *state = (struct ipc_sock_state *)bfd->data;
+	struct osmo_fd *conn_bfd = &state->conn_bfd;
+	struct sockaddr_un un_addr;
+	socklen_t len;
+	int rc;
+
+	len = sizeof(un_addr);
+	rc = accept(bfd->fd, (struct sockaddr *)&un_addr, &len);
+	if (rc < 0) {
+		LOGP(DDEV, LOGL_ERROR, "Failed to accept a new connection\n");
+		return -1;
+	}
+
+	if (conn_bfd->fd >= 0) {
+		LOGP(DDEV, LOGL_NOTICE,
+		     "osmo-trx connects but we already have "
+		     "another active connection ?!?\n");
+		/* We already have one IPC connected, this is all we support */
+		state->listen_bfd.when &= ~BSC_FD_READ;
+		close(rc);
+		return 0;
+	}
+
+	conn_bfd->fd = rc;
+	conn_bfd->when = BSC_FD_READ;
+	conn_bfd->cb = ipc_chan_sock_cb;
+	conn_bfd->data = state;
+
+	/* copy chan nr, required for proper bfd<->chan # mapping */
+	conn_bfd->priv_nr = bfd->priv_nr;
+
+	if (osmo_fd_register(conn_bfd) != 0) {
+		LOGP(DDEV, LOGL_ERROR,
+		     "Failed to register new connection "
+		     "fd\n");
+		close(conn_bfd->fd);
+		conn_bfd->fd = -1;
+		return -1;
+	}
+
+	LOGP(DDEV, LOGL_NOTICE, "Unix socket connected to external osmo-trx\n");
+
+	return 0;
+}