+++ /dev/null
-/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
- *
- * lttng-context-hostname.c
- *
- * LTTng hostname context.
- *
- * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- */
-
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/sched.h>
-#include <linux/utsname.h>
-#include <lttng/events.h>
-#include <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;
-
- /*
- * No need to take the RCU read-side lock to read current
- * nsproxy. (documented in nsproxy.h)
- */
- nsproxy = current->nsproxy;
- 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);
- }
-}
-
-static
-void hostname_get_value(struct lttng_ctx_field *field,
- struct lttng_probe_ctx *lttng_probe_ctx,
- union lttng_ctx_value *value)
-{
- struct nsproxy *nsproxy;
- struct uts_namespace *ns;
- char *hostname;
-
- /*
- * No need to take the RCU read-side lock to read current
- * nsproxy. (documented in nsproxy.h)
- */
- nsproxy = current->nsproxy;
- if (nsproxy) {
- ns = nsproxy->uts_ns;
- hostname = ns->name.nodename;
- } else {
- hostname = "";
- }
- value->str = hostname;
-}
-
-static const struct lttng_type hostname_array_elem_type =
- __type_integer(char, 0, 0, -1, __BYTE_ORDER, 10, UTF8);
-
-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_nestable;
- field->event_field.type.u.array_nestable.elem_type =
- &hostname_array_elem_type;
- field->event_field.type.u.array_nestable.length = LTTNG_HOSTNAME_CTX_LEN;
- field->event_field.type.u.array_nestable.alignment = 0;
-
- field->get_size = hostname_get_size;
- field->record = hostname_record;
- field->get_value = hostname_get_value;
- lttng_context_update(*ctx);
- wrapper_vmalloc_sync_mappings();
- return 0;
-}
-EXPORT_SYMBOL_GPL(lttng_add_hostname_to_ctx);