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53569322 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-only |
53569322 MD |
3 | * |
4 | * Copyright (C) 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
c0c0989a | 6 | * LTTng UST application context provider. |
53569322 MD |
7 | */ |
8 | ||
3fbec7dc | 9 | #define _LGPL_SOURCE |
b4051ad8 | 10 | #include <stddef.h> |
fb31eb73 | 11 | #include <stdint.h> |
53569322 MD |
12 | #include <sys/types.h> |
13 | #include <unistd.h> | |
fb31eb73 | 14 | |
9d315d6d | 15 | #include <common/ust-context-provider.h> |
d8d2416d | 16 | |
fc80554e | 17 | #include "context-internal.h" |
53569322 | 18 | #include "lttng-tracer-core.h" |
e58e5ad5 | 19 | #include "common/jhash.h" |
d8d2416d | 20 | #include "context-provider-internal.h" |
9d315d6d | 21 | #include "common/macros.h" |
53569322 | 22 | |
4e48b5d2 MD |
23 | struct lttng_ust_registered_context_provider { |
24 | const struct lttng_ust_context_provider *provider; | |
25 | ||
26 | struct cds_hlist_node node; | |
27 | }; | |
28 | ||
f26f2f9b MD |
29 | struct lttng_ust_app_ctx { |
30 | char *name; | |
31 | struct lttng_ust_event_field *event_field; | |
32 | struct lttng_ust_type_common *type; | |
33 | }; | |
34 | ||
53569322 MD |
35 | #define CONTEXT_PROVIDER_HT_BITS 12 |
36 | #define CONTEXT_PROVIDER_HT_SIZE (1U << CONTEXT_PROVIDER_HT_BITS) | |
37 | struct context_provider_ht { | |
38 | struct cds_hlist_head table[CONTEXT_PROVIDER_HT_SIZE]; | |
39 | }; | |
40 | ||
41 | static struct context_provider_ht context_provider_ht; | |
42 | ||
4e48b5d2 | 43 | static const struct lttng_ust_context_provider * |
53569322 MD |
44 | lookup_provider_by_name(const char *name) |
45 | { | |
46 | struct cds_hlist_head *head; | |
47 | struct cds_hlist_node *node; | |
4e48b5d2 | 48 | struct lttng_ust_registered_context_provider *reg_provider; |
53569322 MD |
49 | uint32_t hash; |
50 | const char *end; | |
51 | size_t len; | |
52 | ||
53 | /* Lookup using everything before first ':' as key. */ | |
54 | end = strchr(name, ':'); | |
55 | if (end) | |
56 | len = end - name; | |
57 | else | |
58 | len = strlen(name); | |
59 | hash = jhash(name, len, 0); | |
60 | head = &context_provider_ht.table[hash & (CONTEXT_PROVIDER_HT_SIZE - 1)]; | |
4e48b5d2 MD |
61 | cds_hlist_for_each_entry(reg_provider, node, head, node) { |
62 | if (!strncmp(reg_provider->provider->name, name, len)) | |
63 | return reg_provider->provider; | |
53569322 MD |
64 | } |
65 | return NULL; | |
66 | } | |
67 | ||
4e48b5d2 | 68 | struct lttng_ust_registered_context_provider *lttng_ust_context_provider_register(struct lttng_ust_context_provider *provider) |
53569322 | 69 | { |
4e48b5d2 | 70 | struct lttng_ust_registered_context_provider *reg_provider = NULL; |
53569322 MD |
71 | struct cds_hlist_head *head; |
72 | size_t name_len = strlen(provider->name); | |
73 | uint32_t hash; | |
53569322 | 74 | |
a9fd951a | 75 | lttng_ust_alloc_tls(); |
c362addf | 76 | |
53569322 | 77 | /* Provider name starts with "$app.". */ |
fe94775b | 78 | if (strncmp("$app.", provider->name, strlen("$app.")) != 0) |
4e48b5d2 | 79 | return NULL; |
8b05d0d4 | 80 | /* Provider name cannot contain a colon character. */ |
53569322 | 81 | if (strchr(provider->name, ':')) |
4e48b5d2 MD |
82 | return NULL; |
83 | if (ust_lock()) | |
53569322 | 84 | goto end; |
4e48b5d2 | 85 | if (lookup_provider_by_name(provider->name)) |
53569322 | 86 | goto end; |
4e48b5d2 MD |
87 | reg_provider = zmalloc(sizeof(struct lttng_ust_registered_context_provider)); |
88 | if (!reg_provider) | |
89 | goto end; | |
90 | reg_provider->provider = provider; | |
53569322 MD |
91 | hash = jhash(provider->name, name_len, 0); |
92 | head = &context_provider_ht.table[hash & (CONTEXT_PROVIDER_HT_SIZE - 1)]; | |
4e48b5d2 | 93 | cds_hlist_add_head(®_provider->node, head); |
d8d2416d | 94 | |
53569322 MD |
95 | lttng_ust_context_set_session_provider(provider->name, |
96 | provider->get_size, provider->record, | |
4e48b5d2 | 97 | provider->get_value, provider->priv); |
d8d2416d FD |
98 | |
99 | lttng_ust_context_set_event_notifier_group_provider(provider->name, | |
100 | provider->get_size, provider->record, | |
4e48b5d2 | 101 | provider->get_value, provider->priv); |
53569322 MD |
102 | end: |
103 | ust_unlock(); | |
4e48b5d2 | 104 | return reg_provider; |
53569322 MD |
105 | } |
106 | ||
4e48b5d2 | 107 | void lttng_ust_context_provider_unregister(struct lttng_ust_registered_context_provider *reg_provider) |
53569322 | 108 | { |
a9fd951a | 109 | lttng_ust_alloc_tls(); |
c362addf | 110 | |
53569322 MD |
111 | if (ust_lock()) |
112 | goto end; | |
4e48b5d2 | 113 | lttng_ust_context_set_session_provider(reg_provider->provider->name, |
ce7352a2 | 114 | lttng_ust_dummy_get_size, lttng_ust_dummy_record, |
4e48b5d2 | 115 | lttng_ust_dummy_get_value, NULL); |
d8d2416d | 116 | |
4e48b5d2 | 117 | lttng_ust_context_set_event_notifier_group_provider(reg_provider->provider->name, |
d8d2416d | 118 | lttng_ust_dummy_get_size, lttng_ust_dummy_record, |
4e48b5d2 | 119 | lttng_ust_dummy_get_value, NULL); |
d8d2416d | 120 | |
4e48b5d2 | 121 | cds_hlist_del(®_provider->node); |
53569322 MD |
122 | end: |
123 | ust_unlock(); | |
4e48b5d2 | 124 | free(reg_provider); |
53569322 MD |
125 | } |
126 | ||
f26f2f9b MD |
127 | static void destroy_app_ctx(void *priv) |
128 | { | |
129 | struct lttng_ust_app_ctx *app_ctx = (struct lttng_ust_app_ctx *) priv; | |
130 | ||
131 | free(app_ctx->name); | |
132 | free(app_ctx->event_field); | |
133 | free(app_ctx->type); | |
134 | free(app_ctx); | |
135 | } | |
136 | ||
53569322 MD |
137 | /* |
138 | * Called with ust mutex held. | |
139 | * Add application context to array of context, even if the application | |
140 | * context is not currently loaded by application. It will then use the | |
141 | * dummy callbacks in that case. | |
142 | * Always performed before tracing is started, since it modifies | |
143 | * metadata describing the context. | |
144 | */ | |
145 | int lttng_ust_add_app_context_to_ctx_rcu(const char *name, | |
daacdbfc | 146 | struct lttng_ust_ctx **ctx) |
53569322 | 147 | { |
4e48b5d2 | 148 | const struct lttng_ust_context_provider *provider; |
f26f2f9b | 149 | struct lttng_ust_ctx_field new_field = { 0 }; |
4e48b5d2 MD |
150 | struct lttng_ust_event_field *event_field = NULL; |
151 | struct lttng_ust_type_common *type = NULL; | |
f26f2f9b MD |
152 | struct lttng_ust_app_ctx *app_ctx = NULL; |
153 | char *ctx_name; | |
53569322 MD |
154 | int ret; |
155 | ||
156 | if (*ctx && lttng_find_context(*ctx, name)) | |
157 | return -EEXIST; | |
4e48b5d2 MD |
158 | event_field = zmalloc(sizeof(struct lttng_ust_event_field)); |
159 | if (!event_field) { | |
daacdbfc MD |
160 | ret = -ENOMEM; |
161 | goto error_event_field_alloc; | |
162 | } | |
f26f2f9b MD |
163 | ctx_name = strdup(name); |
164 | if (!ctx_name) { | |
daacdbfc MD |
165 | ret = -ENOMEM; |
166 | goto error_field_name_alloc; | |
167 | } | |
4e48b5d2 MD |
168 | type = zmalloc(sizeof(struct lttng_ust_type_common)); |
169 | if (!type) { | |
a084756d MD |
170 | ret = -ENOMEM; |
171 | goto error_field_type_alloc; | |
172 | } | |
f26f2f9b MD |
173 | app_ctx = zmalloc(sizeof(struct lttng_ust_app_ctx)); |
174 | if (!app_ctx) { | |
175 | ret = -ENOMEM; | |
176 | goto error_app_ctx_alloc; | |
177 | } | |
178 | event_field->name = ctx_name; | |
4e48b5d2 MD |
179 | type->type = lttng_ust_type_dynamic; |
180 | event_field->type = type; | |
f26f2f9b | 181 | new_field.event_field = event_field; |
53569322 MD |
182 | /* |
183 | * If provider is not found, we add the context anyway, but | |
184 | * it will provide a dummy context. | |
185 | */ | |
186 | provider = lookup_provider_by_name(name); | |
187 | if (provider) { | |
f26f2f9b MD |
188 | new_field.get_size = provider->get_size; |
189 | new_field.record = provider->record; | |
190 | new_field.get_value = provider->get_value; | |
53569322 | 191 | } else { |
f26f2f9b MD |
192 | new_field.get_size = lttng_ust_dummy_get_size; |
193 | new_field.record = lttng_ust_dummy_record; | |
194 | new_field.get_value = lttng_ust_dummy_get_value; | |
53569322 | 195 | } |
f26f2f9b MD |
196 | new_field.destroy = destroy_app_ctx; |
197 | new_field.priv = app_ctx; | |
daacdbfc MD |
198 | /* |
199 | * For application context, add it by expanding | |
f26f2f9b | 200 | * ctx array. |
daacdbfc | 201 | */ |
f26f2f9b | 202 | ret = lttng_ust_context_append_rcu(ctx, &new_field); |
53569322 | 203 | if (ret) { |
f26f2f9b | 204 | destroy_app_ctx(app_ctx); |
53569322 MD |
205 | return ret; |
206 | } | |
207 | return 0; | |
daacdbfc | 208 | |
f26f2f9b MD |
209 | error_app_ctx_alloc: |
210 | free(type); | |
a084756d | 211 | error_field_type_alloc: |
f26f2f9b | 212 | free(ctx_name); |
daacdbfc | 213 | error_field_name_alloc: |
4e48b5d2 | 214 | free(event_field); |
daacdbfc | 215 | error_event_field_alloc: |
daacdbfc | 216 | return ret; |
53569322 | 217 | } |