From: Francis Deslauriers <francis.deslauriers@efficios.com>
Date: Sun, 15 Oct 2017 21:06:49 +0000 (-0400)
Subject: Add utils to send file descriptors to the sessiond
X-Git-Tag: v2.11.0-rc1~98
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=a04d53fc9a0dd3a5d6f9be82d475dfec48205ac0;p=lttng-tools.git

Add utils to send file descriptors to the sessiond

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/lib/lttng-ctl/lttng-ctl-helper.h b/src/lib/lttng-ctl/lttng-ctl-helper.h
index 8e9786bc2..9b50aacf7 100644
--- a/src/lib/lttng-ctl/lttng-ctl-helper.h
+++ b/src/lib/lttng-ctl/lttng-ctl-helper.h
@@ -41,22 +41,33 @@ void lttng_ctl_copy_lttng_domain(struct lttng_domain *dst,
  * Return the size of the received data on success or else a negative lttng
  * error code. If buf is NULL, 0 is returned on success.
  */
-int lttng_ctl_ask_sessiond_varlen(struct lttcomm_session_msg *lsm,
+int lttng_ctl_ask_sessiond_fds_varlen(struct lttcomm_session_msg *lsm,
+		const int *fds, size_t nb_fd,
 		const void *vardata, size_t vardata_len,
 		void **user_payload_buf, void **user_cmd_header_buf,
 		size_t *user_cmd_header_len);
 
 /*
- * Calls lttng_ctl_ask_sessiond_varlen() with no expected command header.
+ * Calls lttng_ctl_ask_sessiond_fds_varlen() with no expected command header.
  */
 static inline
 int lttng_ctl_ask_sessiond_varlen_no_cmd_header(struct lttcomm_session_msg *lsm,
 		void *vardata, size_t vardata_len, void **user_payload_buf)
 {
-	return lttng_ctl_ask_sessiond_varlen(lsm, vardata,
+	return lttng_ctl_ask_sessiond_fds_varlen(lsm, NULL, 0, vardata,
 		vardata_len, user_payload_buf, NULL, NULL);
 }
 
+/*
+ * Calls lttng_ctl_ask_sessiond_fds_varlen() with fds and no expected command header.
+ */
+static inline
+int lttng_ctl_ask_sessiond_fds_no_cmd_header(struct lttcomm_session_msg *lsm,
+		const int *fds, size_t nb_fd, void **buf)
+{
+	return lttng_ctl_ask_sessiond_fds_varlen(lsm, fds, nb_fd, NULL,
+		0, NULL, NULL, NULL);
+}
 /*
  * Use this if no variable length data needs to be sent.
  */
diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
index 37b253102..eadb00eda 100644
--- a/src/lib/lttng-ctl/lttng-ctl.c
+++ b/src/lib/lttng-ctl/lttng-ctl.c
@@ -176,6 +176,35 @@ end:
 	return ret;
 }
 
+/*
+ * Send file descriptors to the session daemon.
+ *
+ * On success, returns the number of bytes sent (>=0)
+ * On error, returns -1
+ */
+static int send_session_fds(const int *fds, size_t nb_fd)
+{
+	int ret;
+
+	if (!connected) {
+		ret = -LTTNG_ERR_NO_SESSIOND;
+		goto end;
+	}
+
+	if (!fds || !nb_fd) {
+		ret = 0;
+		goto end;
+	}
+
+	ret = lttcomm_send_fds_unix_sock(sessiond_socket, fds, nb_fd);
+	if (ret < 0) {
+		ret = -LTTNG_ERR_FATAL;
+	}
+
+end:
+	return ret;
+}
+
 /*
  * Receive data from the sessiond socket.
  *
@@ -445,15 +474,16 @@ end:
 
 /*
  * Ask the session daemon a specific command and put the data into buf.
- * Takes extra var. len. data as input to send to the session daemon.
+ * Takes extra var. len. data and file descriptors as input to send to the
+ * session daemon.
  *
  * Return size of data (only payload, not header) or a negative error code.
  */
 LTTNG_HIDDEN
-int lttng_ctl_ask_sessiond_varlen(struct lttcomm_session_msg *lsm,
-		const void *vardata, size_t vardata_len,
-		void **user_payload_buf, void **user_cmd_header_buf,
-		size_t *user_cmd_header_len)
+int lttng_ctl_ask_sessiond_fds_varlen(struct lttcomm_session_msg *lsm,
+		const int *fds, size_t nb_fd, const void *vardata,
+		size_t vardata_len, void **user_payload_buf,
+		void **user_cmd_header_buf, size_t *user_cmd_header_len)
 {
 	int ret;
 	size_t payload_len;
@@ -478,6 +508,13 @@ int lttng_ctl_ask_sessiond_varlen(struct lttcomm_session_msg *lsm,
 		goto end;
 	}
 
+	/* Send fds */
+	ret = send_session_fds(fds, nb_fd);
+	if (ret < 0) {
+		/* Ret value is a valid lttng error code. */
+		goto end;
+	}
+
 	/* Get header from data transmission */
 	ret = recv_data_sessiond(&llm, sizeof(llm));
 	if (ret < 0) {
@@ -1873,8 +1910,8 @@ int lttng_list_events(struct lttng_handle *handle,
 			sizeof(lsm.u.list.channel_name));
 	lttng_ctl_copy_lttng_domain(&lsm.domain, &handle->domain);
 
-	ret = lttng_ctl_ask_sessiond_varlen(&lsm, NULL, 0, (void **) events,
-		(void **) &cmd_header, &cmd_header_len);
+	ret = lttng_ctl_ask_sessiond_fds_varlen(&lsm, NULL, 0, NULL, 0,
+		(void **) events, (void **) &cmd_header, &cmd_header_len);
 	if (ret < 0) {
 		goto error;
 	}