From cd4484ab068678edfa9335a1c6d7c91b93793970 Mon Sep 17 00:00:00 2001
From: David Lamparter <equinox@diac24.net>
Date: Sat, 1 Jun 2013 00:00:46 +0200
Subject: socketcan v0

---
 cethcan/socketcan.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 cethcan/socketcan.c

(limited to 'cethcan/socketcan.c')

diff --git a/cethcan/socketcan.c b/cethcan/socketcan.c
new file mode 100644
index 0000000..d73ed45
--- /dev/null
+++ b/cethcan/socketcan.c
@@ -0,0 +1,134 @@
+#include "cethcan.h"
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+
+#include <net/if.h>
+#include <linux/can.h>
+#include <linux/can/raw.h>
+
+struct socan {
+	struct can_user *u;
+	struct event *ev;
+
+	char *ifname;
+	int ifindex;
+
+	int sock;
+};
+
+static void socan_handler(void *arg, struct can_message *msg)
+{
+	struct socan *sc = arg;
+	lprintf("%s: TX not implemented", sc->u->name);
+}
+
+static void socan_event(int sock, short event, void *arg)
+{
+	struct socan *sc = arg;
+	struct can_message msg;
+	union {
+		struct sockaddr_can can;
+		struct sockaddr_storage ss;
+		struct sockaddr su;
+	} canaddr;
+	socklen_t addrlen = sizeof(canaddr);
+	struct canfd_frame frame;
+
+	if (event & EV_READ) {
+		ssize_t rlen = recvfrom(sc->sock, &frame, sizeof(frame),
+			MSG_TRUNC, &canaddr.su, &addrlen);
+		if (rlen > 0) {
+#if 0
+			if (1) {
+				lprintf("got %zd bytes", rlen);
+				char pbuffer[16 * 3 + 1];
+				for (size_t i = 0; i < (size_t)rlen; i++) {
+					size_t j = i % 16;
+					sprintf(pbuffer + (3 * j), " %02x", buf.raw[i]);
+					if (j == 15)
+						lprintf(">>%s", pbuffer);
+				}
+				if ((rlen % 16) != 15)
+					lprintf(">>%s", pbuffer);
+			}
+#endif
+			if (frame.can_id & CAN_EFF_FLAG)
+				msg.daddr = 0x00080000
+					| (frame.can_id & 0x0003ffff)
+					| ((frame.can_id & 0x1ffc0000) << 3);
+			else
+				msg.daddr = (frame.can_id & 0x7ff) << 21;
+			msg.dlc = frame.len;
+			if (msg.dlc > 8)
+				msg.dlc = 8;
+			memcpy(msg.bytes, frame.data, msg.dlc);
+			can_broadcast(sc->u, &msg);
+		}
+	}
+}
+
+int socan_init(json_t *config)
+{
+	struct socan *sc;
+	const char *iface;
+	int ifindex;
+	int on = 1;
+	struct sockaddr_can addr;
+
+	if (!json_is_object(config)) {
+		lprintf("socketcan config must be an object/dictionary");
+		return 1;
+	}
+	if (!json_is_string(json_object_get(config, "interface"))) {
+		lprintf("socketcan config must have an 'interface' key");
+		return 1;
+	}
+	iface = json_string_value(json_object_get(config, "interface"));
+	ifindex = if_nametoindex(iface);
+
+	if (ifindex == 0) {
+		lprintf("socketcan interface '%s' error: %s",
+			iface, strerror(errno));
+		return 1;
+	}
+
+	sc = calloc(sizeof(*sc), 1);
+	sc->ifname = strdup(iface);
+	sc->ifindex = ifindex;
+
+	sc->sock = socket(PF_CAN, SOCK_RAW, CAN_RAW);
+	if (sc->sock == -1) {
+		lprintf("socketcan interface '%s' socket() error: %s",
+			iface, strerror(errno));
+		free(sc);
+		return 1;
+	}
+	if (setsockopt(sc->sock, SOL_CAN_RAW, CAN_RAW_FD_FRAMES,
+		&on, sizeof(on))) {
+		lprintf("socketcan interface '%s' raw_fd_frames error: %s",
+			iface, strerror(errno));
+		return 1;
+	}
+/*	if (setsockopt(sc->sock, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on))) {
+		lprintf("socketcan interface '%s' so_timestamp error: %s",
+			iface, strerror(errno));
+		return 1;
+	} */
+
+	addr.can_family = AF_CAN;
+	addr.can_ifindex = ifindex;
+	if (bind(sc->sock, (struct sockaddr *)&addr, sizeof(addr))) {
+		lprintf("socketcan interface '%s' bind error: %s",
+			iface, strerror(errno));
+		return 1;
+	}
+
+	sc->u = can_register_alloc(sc, socan_handler, "socketcan[%s]", iface);
+	sc->ev = event_new(ev_base, sc->sock, EV_READ | EV_PERSIST,
+		socan_event, sc);
+	event_add(sc->ev, NULL);
+
+	return 0;
+}
-- 
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