Add implementation for SCPI over TCP.

hardware/common/Makefile.am

@@ -22,10 +22,10 @@ SUBDIRS = dmm
 # Local lib, this is NOT meant to be installed!
 noinst_LTLIBRARIES = libsigrok_hw_common.la
 
-libsigrok_hw_common_la_SOURCES =
+libsigrok_hw_common_la_SOURCES = scpi.c scpi_tcp.c
 
 if NEED_SERIAL
-libsigrok_hw_common_la_SOURCES += serial.c scpi.c scpi_serial.c scpi_usbtmc.c
+libsigrok_hw_common_la_SOURCES += serial.c scpi_serial.c scpi_usbtmc.c
 endif
 
 if NEED_USB

hardware/common/scpi_tcp.c

@@ -0,0 +1,214 @@
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2013 Martin Ling <martin-sigrok@earth.li>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
+
+#include <glib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <errno.h>
+
+/* Message logging helpers with subsystem-specific prefix string. */
+#define LOG_PREFIX "scpi_tcp: "
+#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
+#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
+#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
+#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
+#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
+
+struct scpi_tcp {
+	char *address;
+	char *port;
+	int socket;
+};
+
+SR_PRIV int scpi_tcp_open(void *priv)
+{
+	struct scpi_tcp *tcp = priv;
+	struct addrinfo hints;
+	struct addrinfo *results, *res;
+	int err;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_protocol = IPPROTO_TCP;
+
+	err = getaddrinfo(tcp->address, tcp->port, &hints, &results);
+
+	if (err) {
+		sr_err("Address lookup failed: %s:%d: %s", tcp->address, tcp->port,
+			gai_strerror(err));
+		return SR_ERR;
+	}
+
+	for (res = results; res; res = res->ai_next) {
+		if ((tcp->socket = socket(res->ai_family, res->ai_socktype,
+						res->ai_protocol)) < 0)
+			continue;
+		if (connect(tcp->socket, res->ai_addr, res->ai_addrlen) != 0) {
+			close(tcp->socket);
+			tcp->socket = -1;
+			continue;
+		}
+		break;
+	}
+
+	freeaddrinfo(results);
+
+	if (tcp->socket < 0) {
+		sr_err("Failed to connect to %s:%s: %s", tcp->address, tcp->port,
+				strerror(errno));
+		return SR_ERR;
+	}
+
+	return SR_OK;
+}
+
+SR_PRIV int scpi_tcp_source_add(void *priv, int events, int timeout,
+			sr_receive_data_callback_t cb, void *cb_data)
+{
+	struct scpi_tcp *tcp = priv;
+
+	return sr_source_add(tcp->socket, events, timeout, cb, cb_data);
+}
+
+SR_PRIV int scpi_tcp_source_remove(void *priv)
+{
+	struct scpi_tcp *tcp = priv;
+
+	return sr_source_remove(tcp->socket);
+}
+
+SR_PRIV int scpi_tcp_send(void *priv, const char *command)
+{
+	struct scpi_tcp *tcp = priv;
+	int len, out;
+
+	len = strlen(command);
+	out = send(tcp->socket, command, len, 0);
+
+	if (out < 0) {
+		sr_err("Send error: %s", strerror(errno));
+		return SR_ERR;
+	}
+
+	if (out < len) {
+		sr_dbg("Only sent %d/%d bytes of SCPI command: '%s'.", out,
+		       len, command);
+	}
+
+	sr_spew("Successfully sent SCPI command: '%s'.", command);
+
+	return SR_OK;
+}
+
+SR_PRIV int scpi_tcp_receive(void *priv, char **scpi_response)
+{
+	struct scpi_tcp *tcp = priv;
+	GString *response;
+	char buf[256];
+	int len;
+
+	response = g_string_sized_new(1024);
+
+	len = recv(tcp->socket, buf, sizeof(buf), 0);
+
+	if (len < 0) {
+		sr_err("Receive error: %s", strerror(errno));
+		g_string_free(response, TRUE);
+		return SR_ERR;
+	}
+
+	response = g_string_append_len(response, buf, len);
+
+	*scpi_response = response->str;
+
+	sr_dbg("SCPI response received (length %d): '%.50s'",
+	       response->len, response->str);
+
+	g_string_free(response, FALSE);
+
+	return SR_OK;
+}
+
+SR_PRIV int scpi_tcp_read(void *priv, char *buf, int maxlen)
+{
+	struct scpi_tcp *tcp = priv;
+	int len;
+
+	len = recv(tcp->socket, buf, maxlen, 0);
+
+	if (len < 0) {
+		sr_err("Receive error: %s", strerror(errno));
+		return SR_ERR;
+	}
+
+	return len;
+}
+
+SR_PRIV int scpi_tcp_close(void *priv)
+{
+	struct scpi_tcp *tcp = priv;
+
+	if (close(tcp->socket) < 0)
+		return SR_ERR;
+
+	return SR_OK;
+}
+
+SR_PRIV void scpi_tcp_free(void *priv)
+{
+	struct scpi_tcp *tcp = priv;
+
+	g_free(tcp->address);
+	g_free(tcp->port);
+	g_free(tcp);
+}
+
+SR_PRIV struct sr_scpi_dev_inst *scpi_tcp_dev_inst_new(const char *address,
+		const char *port)
+{
+	struct sr_scpi_dev_inst *scpi;
+	struct scpi_tcp *tcp;
+
+	scpi = g_malloc(sizeof(struct sr_scpi_dev_inst));
+	tcp = g_malloc0(sizeof(struct scpi_tcp));
+
+	tcp->address = g_strdup(address);
+	tcp->port = g_strdup(port);
+	tcp->socket = -1;
+
+	scpi->open = scpi_tcp_open;
+	scpi->source_add = scpi_tcp_source_add;
+	scpi->source_remove = scpi_tcp_source_remove;
+	scpi->send = scpi_tcp_send;
+	scpi->receive = scpi_tcp_receive;
+	scpi->read = scpi_tcp_read;
+	scpi->close = scpi_tcp_close;
+	scpi->free = scpi_tcp_free;
+	scpi->priv = tcp;
+
+	return scpi;
+}

libsigrok-internal.h

@@ -336,6 +336,11 @@ SR_PRIV struct sr_scpi_dev_inst *scpi_serial_dev_inst_new(const char *port,
 		        const char *serialcomm);
 #endif
 
+/*--- hardware/common/scpi_tcp.c --------------------------------------------*/
+
+SR_PRIV struct sr_scpi_dev_inst *scpi_tcp_dev_inst_new(const char *address,
+			const char *port);
+
 /*--- hardware/common/scpi_usbtmc.c -----------------------------------------*/
 
 SR_PRIV struct sr_scpi_dev_inst *scpi_usbtmc_dev_inst_new(const char *device);