[lttng-modules.git] / lttng-context-net-ns.c

/* 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 <wrapper/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_all();
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_net_ns_to_ctx);

#endif
Commit	Line	Data
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
a6cf40a4 MJ	2	*
	3	* lttng-context-net-ns.c
	4	*
	5	* LTTng net namespace context.
	6	*
	7	* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	8	* 2019 Michael Jeanson <mjeanson@efficios.com>
	9	*
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/slab.h>
	14	#include <linux/sched.h>
7b1edb4c	15	#include <linux/nsproxy.h>
a6cf40a4 MJ	16	#include <net/net_namespace.h>
	17	#include <lttng-events.h>
	18	#include <wrapper/ringbuffer/frontend_types.h>
	19	#include <wrapper/vmalloc.h>
	20	#include <wrapper/namespace.h>
	21	#include <lttng-tracer.h>
	22
	23	#if defined(CONFIG_NET_NS) && \
	24	(LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
	25
	26	static
	27	size_t net_ns_get_size(size_t offset)
	28	{
	29	size_t size = 0;
	30
	31	size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int));
	32	size += sizeof(unsigned int);
	33	return size;
	34	}
	35
	36	static
	37	void net_ns_record(struct lttng_ctx_field *field,
	38	struct lib_ring_buffer_ctx *ctx,
	39	struct lttng_channel *chan)
	40	{
	41	unsigned int net_ns_inum = 0;
	42
	43	/*
	44	* nsproxy can be NULL when scheduled out of exit.
	45	*
	46	* As documented in 'linux/nsproxy.h' namespaces access rules, no
	47	* precautions should be taken when accessing the current task's
	48	* namespaces, just dereference the pointers.
	49	*/
	50	if (current->nsproxy)
	51	net_ns_inum = current->nsproxy->net_ns->lttng_ns_inum;
	52
	53	lib_ring_buffer_align_ctx(ctx, lttng_alignof(net_ns_inum));
	54	chan->ops->event_write(ctx, &net_ns_inum, sizeof(net_ns_inum));
	55	}
	56
	57	static
	58	void net_ns_get_value(struct lttng_ctx_field *field,
	59	struct lttng_probe_ctx *lttng_probe_ctx,
	60	union lttng_ctx_value *value)
	61	{
	62	unsigned int net_ns_inum = 0;
	63
	64	/*
	65	* nsproxy can be NULL when scheduled out of exit.
	66	*
	67	* As documented in 'linux/nsproxy.h' namespaces access rules, no
	68	* precautions should be taken when accessing the current task's
	69	* namespaces, just dereference the pointers.
	70	*/
	71	if (current->nsproxy)
	72	net_ns_inum = current->nsproxy->net_ns->lttng_ns_inum;
	73
	74	value->s64 = net_ns_inum;
	75	}
	76
	77	int lttng_add_net_ns_to_ctx(struct lttng_ctx **ctx)
	78	{
	79	struct lttng_ctx_field *field;
80
81	field = lttng_append_context(ctx);
82	if (!field)
83	return -ENOMEM;
84	if (lttng_find_context(*ctx, "net_ns")) {
85	lttng_remove_context_field(ctx, field);
86	return -EEXIST;
87	}
88	field->event_field.name = "net_ns";
89	field->event_field.type.atype = atype_integer;
ceabb767 MD	90	field->event_field.type.u.integer.size = sizeof(unsigned int) * CHAR_BIT;
	91	field->event_field.type.u.integer.alignment = lttng_alignof(unsigned int) * CHAR_BIT;
	92	field->event_field.type.u.integer.signedness = lttng_is_signed_type(unsigned int);
	93	field->event_field.type.u.integer.reverse_byte_order = 0;
	94	field->event_field.type.u.integer.base = 10;
	95	field->event_field.type.u.integer.encoding = lttng_encode_none;
a6cf40a4 MJ	96	field->get_size = net_ns_get_size;
	97	field->record = net_ns_record;
	98	field->get_value = net_ns_get_value;
	99	lttng_context_update(*ctx);
	100	wrapper_vmalloc_sync_all();
	101	return 0;
	102	}
	103	EXPORT_SYMBOL_GPL(lttng_add_net_ns_to_ctx);
	104
	105	#endif