X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=src%2Flttng-context-net-ns.c;fp=src%2Flttng-context-net-ns.c;h=879a61bd45dd71ef8c5ef0c972024f97cfb0bf00;hb=cfa6cc1d0f01c2cfcc1a679abf3a6572d411c309;hp=0000000000000000000000000000000000000000;hpb=cd4486798c2b046ea93b89439cd705e93c40b349;p=deliverable%2Flttng-modules.git

diff --git a/src/lttng-context-net-ns.c b/src/lttng-context-net-ns.c
new file mode 100644
index 00000000..879a61bd
--- /dev/null
+++ b/src/lttng-context-net-ns.c
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
+ *
+ * lttng-context-net-ns.c
+ *
+ * LTTng net namespace context.
+ *
+ * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *               2019 Michael Jeanson <mjeanson@efficios.com>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
+#include <lttng/events.h>
+#include <ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <wrapper/namespace.h>
+#include <lttng/tracer.h>
+
+#if defined(CONFIG_NET_NS) && \
+	(LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
+
+static
+size_t net_ns_get_size(size_t offset)
+{
+	size_t size = 0;
+
+	size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int));
+	size += sizeof(unsigned int);
+	return size;
+}
+
+static
+void net_ns_record(struct lttng_ctx_field *field,
+		 struct lib_ring_buffer_ctx *ctx,
+		 struct lttng_channel *chan)
+{
+	unsigned int net_ns_inum = 0;
+
+	/*
+	 * nsproxy can be NULL when scheduled out of exit.
+	 *
+	 * As documented in 'linux/nsproxy.h' namespaces access rules, no
+	 * precautions should be taken when accessing the current task's
+	 * namespaces, just dereference the pointers.
+	 */
+	if (current->nsproxy)
+		net_ns_inum = current->nsproxy->net_ns->lttng_ns_inum;
+
+	lib_ring_buffer_align_ctx(ctx, lttng_alignof(net_ns_inum));
+	chan->ops->event_write(ctx, &net_ns_inum, sizeof(net_ns_inum));
+}
+
+static
+void net_ns_get_value(struct lttng_ctx_field *field,
+		struct lttng_probe_ctx *lttng_probe_ctx,
+		union lttng_ctx_value *value)
+{
+	unsigned int net_ns_inum = 0;
+
+	/*
+	 * nsproxy can be NULL when scheduled out of exit.
+	 *
+	 * As documented in 'linux/nsproxy.h' namespaces access rules, no
+	 * precautions should be taken when accessing the current task's
+	 * namespaces, just dereference the pointers.
+	 */
+	if (current->nsproxy)
+		net_ns_inum = current->nsproxy->net_ns->lttng_ns_inum;
+
+	value->s64 = net_ns_inum;
+}
+
+int lttng_add_net_ns_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, "net_ns")) {
+		lttng_remove_context_field(ctx, field);
+		return -EEXIST;
+	}
+	field->event_field.name = "net_ns";
+	field->event_field.type.atype = atype_integer;
+	field->event_field.type.u.integer.size = sizeof(unsigned int) * CHAR_BIT;
+	field->event_field.type.u.integer.alignment = lttng_alignof(unsigned int) * CHAR_BIT;
+	field->event_field.type.u.integer.signedness = lttng_is_signed_type(unsigned int);
+	field->event_field.type.u.integer.reverse_byte_order = 0;
+	field->event_field.type.u.integer.base = 10;
+	field->event_field.type.u.integer.encoding = lttng_encode_none;
+	field->get_size = net_ns_get_size;
+	field->record = net_ns_record;
+	field->get_value = net_ns_get_value;
+	lttng_context_update(*ctx);
+	wrapper_vmalloc_sync_mappings();
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lttng_add_net_ns_to_ctx);
+
+#endif