X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-context-hostname.c;fp=lttng-context-hostname.c;h=e38340b72ec7bf53f8272ddacac5cf7434212498;hb=975da2c003441a8a16a36947e9500237c197e91b;hp=0000000000000000000000000000000000000000;hpb=90fffd13d9803770838eab195e4f091753cbc7b5;p=lttng-modules.git

diff --git a/lttng-context-hostname.c b/lttng-context-hostname.c
new file mode 100644
index 00000000..e38340b7
--- /dev/null
+++ b/lttng-context-hostname.c
@@ -0,0 +1,97 @@
+/*
+ * lttng-context-hostname.c
+ *
+ * LTTng hostname context.
+ *
+ * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/utsname.h>
+#include "lttng-events.h"
+#include "wrapper/ringbuffer/frontend_types.h"
+#include "wrapper/vmalloc.h"
+#include "lttng-tracer.h"
+
+#define LTTNG_HOSTNAME_CTX_LEN	(__NEW_UTS_LEN + 1)
+
+static
+size_t hostname_get_size(size_t offset)
+{
+	size_t size = 0;
+
+	size += LTTNG_HOSTNAME_CTX_LEN;
+	return size;
+}
+
+static
+void hostname_record(struct lttng_ctx_field *field,
+		 struct lib_ring_buffer_ctx *ctx,
+		 struct lttng_channel *chan)
+{
+	struct nsproxy *nsproxy;
+	struct uts_namespace *ns;
+	char *hostname;
+
+	rcu_read_lock();
+	nsproxy = task_nsproxy(current);
+	if (nsproxy) {
+		ns = nsproxy->uts_ns;
+		hostname = ns->name.nodename;
+		chan->ops->event_write(ctx, hostname,
+				LTTNG_HOSTNAME_CTX_LEN);
+	} else {
+		chan->ops->event_memset(ctx, 0,
+				LTTNG_HOSTNAME_CTX_LEN);
+	}
+	rcu_read_unlock();
+}
+
+int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx)
+{
+	struct lttng_ctx_field *field;
+
+	field = lttng_append_context(ctx);
+	if (!field)
+		return -ENOMEM;
+	if (lttng_find_context(*ctx, "hostname")) {
+		lttng_remove_context_field(ctx, field);
+		return -EEXIST;
+	}
+	field->event_field.name = "hostname";
+	field->event_field.type.atype = atype_array;
+	field->event_field.type.u.array.elem_type.atype = atype_integer;
+	field->event_field.type.u.array.elem_type.u.basic.integer.size = sizeof(char) * CHAR_BIT;
+	field->event_field.type.u.array.elem_type.u.basic.integer.alignment = lttng_alignof(char) * CHAR_BIT;
+	field->event_field.type.u.array.elem_type.u.basic.integer.signedness = is_signed_type(char);
+	field->event_field.type.u.array.elem_type.u.basic.integer.reverse_byte_order = 0;
+	field->event_field.type.u.array.elem_type.u.basic.integer.base = 10;
+	field->event_field.type.u.array.elem_type.u.basic.integer.encoding = lttng_encode_UTF8;
+	field->event_field.type.u.array.length = LTTNG_HOSTNAME_CTX_LEN;
+
+	field->get_size = hostname_get_size;
+	field->record = hostname_record;
+	wrapper_vmalloc_sync_all();
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lttng_add_hostname_to_ctx);
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");