Move wrapper/ringbuffer to include/ringbuffer
[lttng-modules.git] / lttng-context-net-ns.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
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>
15 #include <linux/nsproxy.h>
16 #include <net/net_namespace.h>
17 #include <lttng-events.h>
18 #include <include/ringbuffer/frontend_types.h>
19 #include <lttng-tracer.h>
20
21 #if defined(CONFIG_NET_NS)
22
23 static
24 size_t net_ns_get_size(size_t offset)
25 {
26 size_t size = 0;
27
28 size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int));
29 size += sizeof(unsigned int);
30 return size;
31 }
32
33 static
34 void net_ns_record(struct lttng_ctx_field *field,
35 struct lib_ring_buffer_ctx *ctx,
36 struct lttng_channel *chan)
37 {
38 unsigned int net_ns_inum = 0;
39
40 /*
41 * nsproxy can be NULL when scheduled out of exit.
42 *
43 * As documented in 'linux/nsproxy.h' namespaces access rules, no
44 * precautions should be taken when accessing the current task's
45 * namespaces, just dereference the pointers.
46 */
47 if (current->nsproxy)
48 net_ns_inum = current->nsproxy->net_ns->ns.inum;
49
50 lib_ring_buffer_align_ctx(ctx, lttng_alignof(net_ns_inum));
51 chan->ops->event_write(ctx, &net_ns_inum, sizeof(net_ns_inum));
52 }
53
54 static
55 void net_ns_get_value(struct lttng_ctx_field *field,
56 struct lttng_probe_ctx *lttng_probe_ctx,
57 union lttng_ctx_value *value)
58 {
59 unsigned int net_ns_inum = 0;
60
61 /*
62 * nsproxy can be NULL when scheduled out of exit.
63 *
64 * As documented in 'linux/nsproxy.h' namespaces access rules, no
65 * precautions should be taken when accessing the current task's
66 * namespaces, just dereference the pointers.
67 */
68 if (current->nsproxy)
69 net_ns_inum = current->nsproxy->net_ns->ns.inum;
70
71 value->s64 = net_ns_inum;
72 }
73
74 int lttng_add_net_ns_to_ctx(struct lttng_ctx **ctx)
75 {
76 struct lttng_ctx_field *field;
77
78 field = lttng_append_context(ctx);
79 if (!field)
80 return -ENOMEM;
81 if (lttng_find_context(*ctx, "net_ns")) {
82 lttng_remove_context_field(ctx, field);
83 return -EEXIST;
84 }
85 field->event_field.name = "net_ns";
86 field->event_field.type.atype = atype_integer;
87 field->event_field.type.u.integer.size = sizeof(unsigned int) * CHAR_BIT;
88 field->event_field.type.u.integer.alignment = lttng_alignof(unsigned int) * CHAR_BIT;
89 field->event_field.type.u.integer.signedness = lttng_is_signed_type(unsigned int);
90 field->event_field.type.u.integer.reverse_byte_order = 0;
91 field->event_field.type.u.integer.base = 10;
92 field->event_field.type.u.integer.encoding = lttng_encode_none;
93 field->get_size = net_ns_get_size;
94 field->record = net_ns_record;
95 field->get_value = net_ns_get_value;
96 lttng_context_update(*ctx);
97 return 0;
98 }
99 EXPORT_SYMBOL_GPL(lttng_add_net_ns_to_ctx);
100
101 #endif
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