add logread tool

1 files changed, 199 insertions, 0 deletions

diff --git a/logread.c b/logread.c
new file mode 100644
index 0000000..b7f9ebe
--- /dev/null
+++ b/logread.c
@@ -0,0 +1,199 @@
+/*
+ * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * 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.
+ */
+
+#include <time.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include <libubox/blobmsg_json.h>
+#include <libubox/uloop.h>
+#include "libubus.h"
+
+enum {
+	LOG_MSG,
+	LOG_ID,
+	LOG_PRIO,
+	LOG_SOURCE,
+	LOG_TIME,
+	__LOG_MAX
+};
+
+static const struct blobmsg_policy log_policy[] = {
+	[LOG_MSG] = { .name = "msg", .type = BLOBMSG_TYPE_STRING },
+	[LOG_ID] = { .name = "id", .type = BLOBMSG_TYPE_INT32 },
+	[LOG_PRIO] = { .name = "priority", .type = BLOBMSG_TYPE_INT32 },
+	[LOG_SOURCE] = { .name = "source", .type = BLOBMSG_TYPE_INT32 },
+	[LOG_TIME] = { .name = "time", .type = BLOBMSG_TYPE_INT64 },
+};
+
+enum {
+	WATCH_ID,
+	WATCH_COUNTER,
+	__WATCH_MAX
+};
+
+static struct ubus_subscriber log_event;
+
+static void log_handle_remove(struct ubus_context *ctx, struct ubus_subscriber *s,
+			uint32_t id)
+{
+	fprintf(stderr, "Object %08x went away\n", id);
+}
+
+static int log_notify(struct ubus_context *ctx, struct ubus_object *obj,
+			struct ubus_request_data *req, const char *method,
+			struct blob_attr *msg)
+{
+	struct blob_attr *tb[__LOG_MAX];
+	char *str;
+	time_t t;
+	char *c;
+
+	blobmsg_parse(log_policy, ARRAY_SIZE(log_policy), tb, blob_data(msg), blob_len(msg));
+	if (!tb[LOG_ID] || !tb[LOG_PRIO] || !tb[LOG_SOURCE] || !tb[LOG_TIME])
+		return 1;
+
+	t = blobmsg_get_u64(tb[LOG_TIME]) / 1000;
+	c = ctime(&t);
+	c[strlen(c) - 1] = '\0';
+	str = blobmsg_format_json(msg, true);
+	printf("%s - %s: %s\n",
+		c, (blobmsg_get_u32(tb[LOG_SOURCE])) ? ("syslog") : ("kernel"), method);
+	free(str);
+
+	return 0;
+}
+
+static void follow_log(struct ubus_context *ctx, int id)
+{
+	int ret;
+
+	uloop_init();
+	ubus_add_uloop(ctx);
+
+	log_event.remove_cb = log_handle_remove;
+	log_event.cb = log_notify;
+	ret = ubus_register_subscriber(ctx, &log_event);
+	if (ret)
+		fprintf(stderr, "Failed to add watch handler: %s\n", ubus_strerror(ret));
+
+	ret = ubus_subscribe(ctx, &log_event, id);
+	if (ret)
+		fprintf(stderr, "Failed to add watch handler: %s\n", ubus_strerror(ret));
+
+	uloop_run();
+	ubus_free(ctx);
+	uloop_done();
+}
+
+enum {
+	READ_LINE,
+	__READ_MAX
+};
+
+static const struct blobmsg_policy read_policy[] = {
+	[READ_LINE] = { .name = "lines", .type = BLOBMSG_TYPE_ARRAY },
+};
+
+static void read_cb(struct ubus_request *req, int type, struct blob_attr *msg)
+{
+	struct blob_attr *cur;
+	struct blob_attr *_tb[__READ_MAX];
+	time_t t;
+	int rem;
+
+	if (!msg)
+		return;
+
+	blobmsg_parse(read_policy, ARRAY_SIZE(read_policy), _tb, blob_data(msg), blob_len(msg));
+	if (!_tb[READ_LINE])
+		return;
+	blobmsg_for_each_attr(cur, _tb[READ_LINE], rem) {
+		struct blob_attr *tb[__LOG_MAX];
+		char *c;
+
+		if (blobmsg_type(cur) != BLOBMSG_TYPE_TABLE)
+			continue;
+
+		blobmsg_parse(log_policy, ARRAY_SIZE(log_policy), tb, blobmsg_data(cur), blobmsg_data_len(cur));
+		if (!tb[LOG_MSG] || !tb[LOG_ID] || !tb[LOG_PRIO] || !tb[LOG_SOURCE] || !tb[LOG_TIME])
+			continue;
+
+		t = blobmsg_get_u64(tb[LOG_TIME]) / 1000;
+		c = ctime(&t);
+		c[strlen(c) - 1] = '\0';
+		printf("%s - %s: %s\n",
+			c, (blobmsg_get_u32(tb[LOG_SOURCE])) ? ("syslog") : ("kernel"),
+			blobmsg_get_string(tb[LOG_MSG]));
+	}
+}
+
+static int usage(const char *prog)
+{
+	fprintf(stderr, "Usage: %s [options]\n"
+		"Options:\n"
+		"    -s <path>		Path to ubus socket\n"
+		"    -l	<count>		Got only the last 'count' messages\n"
+		"    -f			Follow log messages\n"
+		"\n", prog);
+	return 1;
+}
+
+int main(int argc, char **argv)
+{
+	struct ubus_context *ctx;
+	uint32_t id;
+	const char *ubus_socket = NULL;
+	int ch, ret, subscribe = 0, lines = 0;
+	static struct blob_buf b;
+
+	while ((ch = getopt(argc, argv, "fs:l:")) != -1) {
+		switch (ch) {
+		case 's':
+			ubus_socket = optarg;
+			break;
+		case 'f':
+			subscribe = 1;
+			break;
+		case 'l':
+			lines = atoi(optarg);
+			break;
+		default:
+			usage(*argv);
+			break;
+		}
+	}
+
+	ctx = ubus_connect(ubus_socket);
+	if (!ctx) {
+		fprintf(stderr, "Failed to connect to ubus\n");
+		return -1;
+	}
+
+	ret = ubus_lookup_id(ctx, "log", &id);
+	if (ret)
+		fprintf(stderr, "Failed to find log object: %s\n", ubus_strerror(ret));
+
+	if (!subscribe || lines) {
+		blob_buf_init(&b, 0);
+		if (lines)
+			blobmsg_add_u32(&b, "lines", lines);
+		ubus_invoke(ctx, id, "read", b.head, read_cb, 0, 3000);
+	}
+
+	if (subscribe)
+		follow_log(ctx, id);
+
+	return 0;
+}