From 53f0df512fb13a5c1b9609a001f9afd5114f2991 Mon Sep 17 00:00:00 2001
From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?=
 <jeremie.galarneau@efficios.com>
Date: Tue, 26 Jan 2016 22:48:21 -0500
Subject: [PATCH] Add app context support to ust-ctl protocol
MIME-Version: 1.0
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Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 include/lttng/ust-abi.h   |  6 ++++
 include/lttng/ust-ctl.h   | 13 ++++++-
 liblttng-ust-ctl/ustctl.c | 74 +++++++++++++++++++++++++++++++++------
 3 files changed, 81 insertions(+), 12 deletions(-)

diff --git a/include/lttng/ust-abi.h b/include/lttng/ust-abi.h
index 126e6124..8cae00e6 100644
--- a/include/lttng/ust-abi.h
+++ b/include/lttng/ust-abi.h
@@ -140,6 +140,7 @@ enum lttng_ust_context_type {
 	LTTNG_UST_CONTEXT_IP			= 4,
 	LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER	= 5,
 	LTTNG_UST_CONTEXT_CPU_ID		= 6,
+	LTTNG_UST_CONTEXT_APP_CONTEXT		= 7,
 };
 
 struct lttng_ust_perf_counter_ctx {
@@ -156,6 +157,11 @@ struct lttng_ust_context {
 
 	union {
 		struct lttng_ust_perf_counter_ctx perf_counter;
+		struct {
+			/* Includes trailing '\0'. */
+			uint32_t provider_name_len;
+			uint32_t ctx_name_len;
+		} app_ctx;
 		char padding[LTTNG_UST_CONTEXT_PADDING2];
 	} u;
 } LTTNG_PACKED;
diff --git a/include/lttng/ust-ctl.h b/include/lttng/ust-ctl.h
index 916eb280..d3c50c5c 100644
--- a/include/lttng/ust-ctl.h
+++ b/include/lttng/ust-ctl.h
@@ -59,6 +59,17 @@ struct ustctl_consumer_channel_attr {
  * API used by sessiond.
  */
 
+struct lttng_ust_context_attr {
+	enum lttng_ust_context_type ctx;
+	union {
+		struct lttng_ust_perf_counter_ctx perf_counter;
+		struct {
+			char *provider_name;
+			char *ctx_name;
+		} app_ctx;
+	} u;
+};
+
 /*
  * Error values: all the following functions return:
  * >= 0: Success (LTTNG_UST_OK)
@@ -69,7 +80,7 @@ int ustctl_create_session(int sock);
 int ustctl_create_event(int sock, struct lttng_ust_event *ev,
 		struct lttng_ust_object_data *channel_data,
 		struct lttng_ust_object_data **event_data);
-int ustctl_add_context(int sock, struct lttng_ust_context *ctx,
+int ustctl_add_context(int sock, struct lttng_ust_context_attr *ctx,
 		struct lttng_ust_object_data *obj_data,
 		struct lttng_ust_object_data **context_data);
 int ustctl_set_filter(int sock, struct lttng_ust_filter_bytecode *bytecode,
diff --git a/liblttng-ust-ctl/ustctl.c b/liblttng-ust-ctl/ustctl.c
index bbf47381..10fb9c49 100644
--- a/liblttng-ust-ctl/ustctl.c
+++ b/liblttng-ust-ctl/ustctl.c
@@ -212,34 +212,86 @@ int ustctl_create_event(int sock, struct lttng_ust_event *ev,
 	return 0;
 }
 
-int ustctl_add_context(int sock, struct lttng_ust_context *ctx,
+int ustctl_add_context(int sock, struct lttng_ust_context_attr *ctx,
 		struct lttng_ust_object_data *obj_data,
 		struct lttng_ust_object_data **_context_data)
 {
 	struct ustcomm_ust_msg lum;
 	struct ustcomm_ust_reply lur;
-	struct lttng_ust_object_data *context_data;
+	struct lttng_ust_object_data *context_data = NULL;
+	char *buf = NULL;
+	size_t len;
 	int ret;
 
-	if (!obj_data || !_context_data)
-		return -EINVAL;
+	if (!obj_data || !_context_data) {
+		ret = -EINVAL;
+		goto end;
+	}
 
 	context_data = zmalloc(sizeof(*context_data));
-	if (!context_data)
-		return -ENOMEM;
+	if (!context_data) {
+		ret = -ENOMEM;
+		goto end;
+	}
 	context_data->type = LTTNG_UST_OBJECT_TYPE_CONTEXT;
 	memset(&lum, 0, sizeof(lum));
 	lum.handle = obj_data->handle;
 	lum.cmd = LTTNG_UST_CONTEXT;
-	lum.u.context = *ctx;
-	ret = ustcomm_send_app_cmd(sock, &lum, &lur);
-	if (ret) {
-		free(context_data);
-		return ret;
+
+	lum.u.context.ctx = ctx->ctx;
+	switch (ctx->ctx) {
+	case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
+		lum.u.context.u.perf_counter = ctx->u.perf_counter;
+		break;
+	case LTTNG_UST_CONTEXT_APP_CONTEXT:
+	{
+		size_t provider_name_len = strlen(
+				ctx->u.app_ctx.provider_name) + 1;
+		size_t ctx_name_len = strlen(ctx->u.app_ctx.ctx_name) + 1;
+
+		lum.u.context.u.app_ctx.provider_name_len = provider_name_len;
+		lum.u.context.u.app_ctx.ctx_name_len = ctx_name_len;
+
+		len = provider_name_len + ctx_name_len;
+		buf = zmalloc(len);
+		if (!buf) {
+			ret = -ENOMEM;
+			goto end;
+		}
+		memcpy(buf, ctx->u.app_ctx.provider_name,
+				provider_name_len);
+		memcpy(buf + provider_name_len, ctx->u.app_ctx.ctx_name,
+				ctx_name_len);
+		break;
+	}
+	default:
+		break;
+	}
+	ret = ustcomm_send_app_msg(sock, &lum);
+	if (ret)
+		goto end;
+	if (buf) {
+		/* send var len ctx_name */
+		ret = ustcomm_send_unix_sock(sock, buf, len);
+		if (ret < 0) {
+			goto end;
+		}
+		if (ret != len) {
+			ret = -EINVAL;
+			goto end;
+		}
+	}
+	ret = ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
+	if (ret < 0) {
+		goto end;
 	}
 	context_data->handle = -1;
 	DBG("Context created successfully");
 	*_context_data = context_data;
+	context_data = NULL;
+end:
+	free(context_data);
+	free(buf);
 	return ret;
 }
 
-- 
2.34.1