X-Git-Url: https://git.lttng.org/?p=lttngtop.git;a=blobdiff_plain;f=src%2Fliblttng-live.c;fp=src%2Fliblttng-live.c;h=3207304d1de2ebfbc12e850ae011e25d7bb5c97d;hp=0000000000000000000000000000000000000000;hb=e3db29663b6e995aa707a060266691cce2507437;hpb=6c7065a7d4c9d1a0e4d64201c7aa0b18bf63b255

diff --git a/src/liblttng-live.c b/src/liblttng-live.c
new file mode 100644
index 0000000..3207304
--- /dev/null
+++ b/src/liblttng-live.c
@@ -0,0 +1,995 @@
+/*
+ * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
+ *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#include <babeltrace/ctf/ctf-index.h>
+
+#include <babeltrace/babeltrace.h>
+#include <babeltrace/ctf/events.h>
+#include <babeltrace/ctf/callbacks.h>
+#include <babeltrace/ctf/iterator.h>
+
+/* for packet_index */
+#include <babeltrace/ctf/types.h>
+
+#include <babeltrace/ctf/metadata.h>
+#include <babeltrace/ctf-text/types.h>
+#include <babeltrace/ctf/events-internal.h>
+/*
+#include <formats/ctf/events-private.h>
+replaced with 
+*/
+#include "network-live.h"
+
+#include "liblttng-live.h"
+#include "lttng-viewer.h"
+#include "lttngtop.h"
+
+/*
+ * Memory allocation zeroed
+ */
+#define zmalloc(x) calloc(1, x)
+
+#ifndef max_t
+#define max_t(type, a, b)	\
+	((type) (a) > (type) (b) ? (type) (a) : (type) (b))
+#endif
+
+int lttng_live_connect_viewer(struct lttng_live_ctx *ctx, char *hostname,
+		int port)
+{
+	struct hostent *host;
+	struct sockaddr_in server_addr;
+	int ret;
+
+	host = gethostbyname(hostname);
+	if (!host) {
+		ret = -1;
+		goto end;
+	}
+
+	if ((ctx->control_sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
+		perror("Socket");
+		ret = -1;
+		goto end;
+	}
+
+	server_addr.sin_family = AF_INET;
+	server_addr.sin_port = htons(port);
+	server_addr.sin_addr = *((struct in_addr *) host->h_addr);
+	bzero(&(server_addr.sin_zero), 8);
+
+	if (connect(ctx->control_sock, (struct sockaddr *) &server_addr,
+				sizeof(struct sockaddr)) == -1) {
+		perror("Connect");
+		ret = -1;
+		goto end;
+	}
+
+	ret = 0;
+
+end:
+	return ret;
+}
+
+int lttng_live_establish_connection(struct lttng_live_ctx *ctx)
+{
+	struct lttng_viewer_cmd cmd;
+	struct lttng_viewer_connect connect;
+	int ret;
+	ssize_t ret_len;
+
+	cmd.cmd = htobe32(LTTNG_VIEWER_CONNECT);
+	cmd.data_size = sizeof(connect);
+	cmd.cmd_version = 0;
+
+	connect.viewer_session_id = -1ULL;	/* will be set on recv */
+	connect.major = htobe32(LTTNG_LIVE_MAJOR);
+	connect.minor = htobe32(LTTNG_LIVE_MINOR);
+	connect.type = htobe32(LTTNG_VIEWER_CLIENT_COMMAND);
+
+	do {
+		ret_len = send(ctx->control_sock, &cmd, sizeof(cmd), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending cmd\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(cmd));
+
+	do {
+		ret_len = send(ctx->control_sock, &connect, sizeof(connect), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending version\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(connect));
+
+	do {
+		ret_len = recv(ctx->control_sock, &connect, sizeof(connect), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error receiving version\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(connect));
+
+	printf_verbose("Received viewer session ID : %" PRIu64 "\n",
+			be64toh(connect.viewer_session_id));
+	printf_verbose("Relayd version : %u.%u\n", be32toh(connect.major),
+			be32toh(connect.minor));
+
+	ret = 0;
+
+error:
+	return ret;
+}
+
+int lttng_live_list_sessions(struct lttng_live_ctx *ctx, const char *path)
+{
+	struct lttng_viewer_cmd cmd;
+	struct lttng_viewer_list_sessions list;
+	struct lttng_viewer_session lsession;
+	int i, ret;
+	ssize_t ret_len;
+	int sessions_count;
+
+	cmd.cmd = htobe32(LTTNG_VIEWER_LIST_SESSIONS);
+	cmd.data_size = 0;
+	cmd.cmd_version = 0;
+
+	do {
+		ret_len = send(ctx->control_sock, &cmd, sizeof(cmd), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending cmd\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(cmd));
+
+	do {
+		ret_len = recv(ctx->control_sock, &list, sizeof(list), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error receiving session list\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(list));
+
+	sessions_count = be32toh(list.sessions_count);
+	fprintf(stdout, "%u active session(s)%c\n", sessions_count,
+			sessions_count > 0 ? ':' : ' ');
+	for (i = 0; i < sessions_count; i++) {
+		do {
+			ret_len = recv(ctx->control_sock, &lsession, sizeof(lsession), 0);
+		} while (ret_len < 0 && errno == EINTR);
+		if (ret_len < 0) {
+			fprintf(stderr, "[error] Error receiving session\n");
+			ret = ret_len;
+			goto error;
+		}
+		assert(ret_len == sizeof(lsession));
+		lsession.hostname[LTTNG_VIEWER_HOST_NAME_MAX - 1] = '\0';
+		lsession.session_name[LTTNG_VIEWER_NAME_MAX - 1] = '\0';
+
+		fprintf(stdout, "%s/%" PRIu64 " : %s on host %s (timer = %u, "
+				"%u stream(s), %u client(s) connected)\n",
+				path, be64toh(lsession.id),
+				lsession.session_name, lsession.hostname,
+				be32toh(lsession.live_timer),
+				be32toh(lsession.streams),
+				be32toh(lsession.clients));
+	}
+
+	ret = 0;
+
+error:
+	return ret;
+}
+
+int lttng_live_ctf_trace_assign(struct lttng_live_viewer_stream *stream,
+		uint64_t ctf_trace_id)
+{
+	struct lttng_live_ctf_trace *trace;
+	int ret = 0;
+
+	trace = g_hash_table_lookup(stream->session->ctf_traces,
+			(gpointer) ctf_trace_id);
+	if (!trace) {
+		trace = g_new0(struct lttng_live_ctf_trace, 1);
+		trace->ctf_trace_id = ctf_trace_id;
+		trace->streams = g_ptr_array_new();
+		g_hash_table_insert(stream->session->ctf_traces,
+				(gpointer) ctf_trace_id,
+				trace);
+	}
+	if (stream->metadata_flag)
+		trace->metadata_stream = stream;
+
+	stream->ctf_trace = trace;
+	g_ptr_array_add(trace->streams, stream);
+
+	return ret;
+}
+
+int lttng_live_attach_session(struct lttng_live_ctx *ctx, uint64_t id)
+{
+	struct lttng_viewer_cmd cmd;
+	struct lttng_viewer_attach_session_request rq;
+	struct lttng_viewer_attach_session_response rp;
+	struct lttng_viewer_stream stream;
+	int ret, i;
+	ssize_t ret_len;
+
+	cmd.cmd = htobe32(LTTNG_VIEWER_ATTACH_SESSION);
+	cmd.data_size = sizeof(rq);
+	cmd.cmd_version = 0;
+
+	memset(&rq, 0, sizeof(rq));
+	rq.session_id = htobe64(id);
+	// TODO: add cmd line parameter to select seek beginning
+	// rq.seek = htobe32(LTTNG_VIEWER_SEEK_BEGINNING);
+	rq.seek = htobe32(LTTNG_VIEWER_SEEK_LAST);
+
+	do {
+		ret_len = send(ctx->control_sock, &cmd, sizeof(cmd), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending cmd\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(cmd));
+
+	do {
+		ret_len = send(ctx->control_sock, &rq, sizeof(rq), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending attach request\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(rq));
+
+	do {
+		ret_len = recv(ctx->control_sock, &rp, sizeof(rp), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error receiving attach response\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(rp));
+
+	switch(be32toh(rp.status)) {
+	case LTTNG_VIEWER_ATTACH_OK:
+		break;
+	case LTTNG_VIEWER_ATTACH_UNK:
+		ret = -LTTNG_VIEWER_ATTACH_UNK;
+		goto end;
+	case LTTNG_VIEWER_ATTACH_ALREADY:
+		fprintf(stderr, "[error] Already a viewer attached\n");
+		ret = -1;
+		goto end;
+	case LTTNG_VIEWER_ATTACH_NOT_LIVE:
+		fprintf(stderr, "[error] Not a live session\n");
+		ret = -1;
+		goto end;
+	case LTTNG_VIEWER_ATTACH_SEEK_ERR:
+		fprintf(stderr, "[error] Wrong seek parameter\n");
+		ret = -1;
+		goto end;
+	default:
+		fprintf(stderr, "[error] Unknown attach return code %u\n",
+				be32toh(rp.status));
+		ret = -1;
+		goto end;
+	}
+	if (be32toh(rp.status) != LTTNG_VIEWER_ATTACH_OK) {
+		ret = -1;
+		goto end;
+	}
+
+	ctx->session->stream_count = be32toh(rp.streams_count);
+	/*
+	 * When the session is created but not started, we do an active wait
+	 * until it starts. It allows the viewer to start processing the trace
+	 * as soon as the session starts.
+	 */
+	if (ctx->session->stream_count == 0) {
+		ret = 0;
+		goto end;
+	}
+	printf_verbose("Waiting for %" PRIu64 " streams:\n",
+		ctx->session->stream_count);
+	ctx->session->streams = g_new0(struct lttng_live_viewer_stream,
+			ctx->session->stream_count);
+	for (i = 0; i < be32toh(rp.streams_count); i++) {
+		do {
+			ret_len = recv(ctx->control_sock, &stream, sizeof(stream), 0);
+		} while (ret_len < 0 && errno == EINTR);
+		if (ret_len < 0) {
+			fprintf(stderr, "[error] Error receiving stream\n");
+			ret = ret_len;
+			goto error;
+		}
+		assert(ret_len == sizeof(stream));
+		stream.path_name[LTTNG_VIEWER_PATH_MAX - 1] = '\0';
+		stream.channel_name[LTTNG_VIEWER_NAME_MAX - 1] = '\0';
+
+		printf_verbose("    stream %" PRIu64 " : %s/%s\n",
+				be64toh(stream.id), stream.path_name,
+				stream.channel_name);
+		ctx->session->streams[i].id = be64toh(stream.id);
+		ctx->session->streams[i].session = ctx->session;
+
+		ctx->session->streams[i].first_read = 1;
+		ctx->session->streams[i].mmap_size = 0;
+
+		if (be32toh(stream.metadata_flag)) {
+			char *path;
+
+			path = strdup(LTTNG_METADATA_PATH_TEMPLATE);
+			if (!path) {
+				perror("strdup");
+				ret = -1;
+				goto error;
+			}
+			if (!mkdtemp(path)) {
+				perror("mkdtemp");
+				free(path);
+				ret = -1;
+				goto error;
+			}
+			ctx->session->streams[i].metadata_flag = 1;
+			snprintf(ctx->session->streams[i].path,
+					sizeof(ctx->session->streams[i].path),
+					"%s/%s", path,
+					stream.channel_name);
+			ret = open(ctx->session->streams[i].path,
+					O_WRONLY | O_CREAT | O_TRUNC,
+					S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+			if (ret < 0) {
+				perror("open");
+				free(path);
+				goto error;
+			}
+			ctx->session->streams[i].fd = ret;
+			free(path);
+		}
+		ret = lttng_live_ctf_trace_assign(&ctx->session->streams[i],
+				be64toh(stream.ctf_trace_id));
+		if (ret < 0) {
+			goto error;
+		}
+
+	}
+	ret = 0;
+
+end:
+error:
+	return ret;
+}
+
+static
+int get_data_packet(struct lttng_live_ctx *ctx,
+		struct ctf_stream_pos *pos,
+		struct lttng_live_viewer_stream *stream, uint64_t offset,
+		uint64_t len)
+{
+	struct lttng_viewer_cmd cmd;
+	struct lttng_viewer_get_packet rq;
+	struct lttng_viewer_trace_packet rp;
+	ssize_t ret_len;
+	int ret;
+
+	cmd.cmd = htobe32(LTTNG_VIEWER_GET_PACKET);
+	cmd.data_size = sizeof(rq);
+	cmd.cmd_version = 0;
+
+	memset(&rq, 0, sizeof(rq));
+	rq.stream_id = htobe64(stream->id);
+	/* Already in big endian. */
+	rq.offset = offset;
+	rq.len = htobe32(len);
+
+	do {
+		ret_len = send(ctx->control_sock, &cmd, sizeof(cmd), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending cmd\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(cmd));
+
+	do {
+		ret_len = send(ctx->control_sock, &rq, sizeof(rq), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending get_data_packet request\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(rq));
+
+	do {
+		ret_len = recv(ctx->control_sock, &rp, sizeof(rp), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error receiving data response\n");
+		ret = ret_len;
+		goto error;
+	}
+	if (ret_len != sizeof(rp)) {
+		fprintf(stderr, "[error] get_data_packet: expected %" PRId64
+				", received %" PRId64 "\n", ret_len,
+				sizeof(rp));
+		ret = -1;
+		goto error;
+	}
+
+	rp.flags = be32toh(rp.flags);
+
+	switch (be32toh(rp.status)) {
+	case LTTNG_VIEWER_GET_PACKET_OK:
+		len = be32toh(rp.len);
+		printf_verbose("get_data_packet: Ok, packet size : %" PRIu64
+				"\n", len);
+		break;
+	case LTTNG_VIEWER_GET_PACKET_RETRY:
+		printf_verbose("get_data_packet: retry\n");
+		ret = -1;
+		goto end;
+	case LTTNG_VIEWER_GET_PACKET_ERR:
+		if (rp.flags & LTTNG_VIEWER_FLAG_NEW_METADATA) {
+			printf_verbose("get_data_packet: new metadata needed\n");
+			ret = 0;
+			goto end;
+		}
+		fprintf(stderr, "[error] get_data_packet: error\n");
+		ret = -1;
+		goto end;
+	case LTTNG_VIEWER_GET_PACKET_EOF:
+		ret = -2;
+		goto error;
+	default:
+		printf_verbose("get_data_packet: unknown\n");
+		assert(0);
+		ret = -1;
+		goto end;
+	}
+
+	if (len <= 0) {
+		ret = -1;
+		goto end;
+	}
+
+	if (len > stream->mmap_size) {
+		uint64_t new_size;
+
+		new_size = max_t(uint64_t, len, stream->mmap_size << 1);
+		if (pos->base_mma) {
+			/* unmap old base */
+			ret = munmap_align(pos->base_mma);
+			if (ret) {
+				fprintf(stderr, "[error] Unable to unmap old base: %s.\n",
+					strerror(errno));
+				ret = -1;
+				goto error;
+			}
+			pos->base_mma = NULL;
+		}
+		pos->base_mma = mmap_align(new_size,
+				PROT_READ | PROT_WRITE,
+				MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+		if (pos->base_mma == MAP_FAILED) {
+			fprintf(stderr, "[error] mmap error %s.\n",
+				strerror(errno));
+			pos->base_mma = NULL;
+			ret = -1;
+			goto error;
+		}
+
+		stream->mmap_size = new_size;
+		printf_verbose("Expanding stream mmap size to %" PRIu64 " bytes\n",
+				stream->mmap_size);
+	}
+
+	do {
+		ret_len = recv(ctx->control_sock,
+			mmap_align_addr(pos->base_mma), len,
+			MSG_WAITALL);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error receiving trace packet\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == len);
+
+end:
+error:
+	return ret;
+}
+
+/*
+ * Return number of metadata bytes written or a negative value on error.
+ */
+static
+int get_new_metadata(struct lttng_live_ctx *ctx,
+		struct lttng_live_viewer_stream *viewer_stream,
+		uint64_t *metadata_len)
+{
+	uint64_t len = 0;
+	int ret;
+	struct lttng_viewer_cmd cmd;
+	struct lttng_viewer_get_metadata rq;
+	struct lttng_viewer_metadata_packet rp;
+	struct lttng_live_viewer_stream *metadata_stream;
+	char *data = NULL;
+	ssize_t ret_len;
+
+	cmd.cmd = htobe32(LTTNG_VIEWER_GET_METADATA);
+	cmd.data_size = sizeof(rq);
+	cmd.cmd_version = 0;
+
+	metadata_stream = viewer_stream->ctf_trace->metadata_stream;
+	rq.stream_id = htobe64(metadata_stream->id);
+
+	do {
+		ret_len = send(ctx->control_sock, &cmd, sizeof(cmd), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending cmd\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(cmd));
+
+	do {
+		ret_len = send(ctx->control_sock, &rq, sizeof(rq), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending get_metadata request\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(rq));
+
+	do {
+		ret_len = recv(ctx->control_sock, &rp, sizeof(rp), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error receiving metadata response\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(rp));
+
+	switch (be32toh(rp.status)) {
+		case LTTNG_VIEWER_METADATA_OK:
+			printf_verbose("get_metadata : OK\n");
+			break;
+		case LTTNG_VIEWER_NO_NEW_METADATA:
+			printf_verbose("get_metadata : NO NEW\n");
+			ret = -1;
+			goto end;
+		case LTTNG_VIEWER_METADATA_ERR:
+			printf_verbose("get_metadata : ERR\n");
+			ret = -1;
+			goto end;
+		default:
+			printf_verbose("get_metadata : UNKNOWN\n");
+			ret = -1;
+			goto end;
+	}
+
+	len = be64toh(rp.len);
+	printf_verbose("Writing %" PRIu64" bytes to metadata\n", len);
+	if (len <= 0) {
+		ret = -1;
+		goto end;
+	}
+
+	data = zmalloc(len);
+	if (!data) {
+		perror("relay data zmalloc");
+		ret = -1;
+		goto error;
+	}
+	do {
+		ret_len = recv(ctx->control_sock, data, len, MSG_WAITALL);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error receiving trace packet\n");
+		ret = ret_len;
+		free(data);
+		goto error;
+	}
+	assert(ret_len == len);
+
+	do {
+		ret_len = write(metadata_stream->fd, data, len);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		free(data);
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == len);
+
+	free(data);
+
+	*metadata_len = len;
+	ret = 0;
+end:
+error:
+	return ret;
+}
+
+/*
+ * Get one index for a stream.
+ *
+ * Returns 0 on success or a negative value on error.
+ */
+static
+int get_next_index(struct lttng_live_ctx *ctx,
+		struct lttng_live_viewer_stream *viewer_stream,
+		struct packet_index *index)
+{
+	struct lttng_viewer_cmd cmd;
+	struct lttng_viewer_get_next_index rq;
+	struct lttng_viewer_index rp;
+	int ret;
+	uint64_t metadata_len;
+	ssize_t ret_len;
+
+	cmd.cmd = htobe32(LTTNG_VIEWER_GET_NEXT_INDEX);
+	cmd.data_size = sizeof(rq);
+	cmd.cmd_version = 0;
+
+	memset(&rq, 0, sizeof(rq));
+	rq.stream_id = htobe64(viewer_stream->id);
+
+retry:
+	do {
+		ret_len = send(ctx->control_sock, &cmd, sizeof(cmd), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending cmd\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(cmd));
+
+	do {
+		ret_len = send(ctx->control_sock, &rq, sizeof(rq), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error sending get_next_index request\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(rq));
+
+	do {
+		ret_len = recv(ctx->control_sock, &rp, sizeof(rp), 0);
+	} while (ret_len < 0 && errno == EINTR);
+	if (ret_len < 0) {
+		fprintf(stderr, "[error] Error receiving index response\n");
+		ret = ret_len;
+		goto error;
+	}
+	assert(ret_len == sizeof(rp));
+
+	rp.flags = be32toh(rp.flags);
+
+	switch (be32toh(rp.status)) {
+	case LTTNG_VIEWER_INDEX_INACTIVE:
+		printf_verbose("get_next_index: inactive\n");
+		memset(index, 0, sizeof(struct packet_index));
+		index->timestamp_end = be64toh(rp.timestamp_end);
+		break;
+	case LTTNG_VIEWER_INDEX_OK:
+		printf_verbose("get_next_index: Ok, need metadata update : %u\n",
+				rp.flags & LTTNG_VIEWER_FLAG_NEW_METADATA);
+		index->offset = be64toh(rp.offset);
+		index->packet_size = be64toh(rp.packet_size);
+		index->content_size = be64toh(rp.content_size);
+		index->timestamp_begin = be64toh(rp.timestamp_begin);
+		index->timestamp_end = be64toh(rp.timestamp_end);
+		index->events_discarded = be64toh(rp.events_discarded);
+
+		if (rp.flags & LTTNG_VIEWER_FLAG_NEW_METADATA) {
+			printf_verbose("get_next_index: new metadata needed\n");
+			ret = get_new_metadata(ctx, viewer_stream,
+					&metadata_len);
+			if (ret < 0) {
+				goto error;
+			}
+		}
+		break;
+	case LTTNG_VIEWER_INDEX_RETRY:
+		printf_verbose("get_next_index: retry\n");
+		sleep(1);
+		goto retry;
+	case LTTNG_VIEWER_INDEX_HUP:
+		printf_verbose("get_next_index: stream hung up\n");
+		viewer_stream->id = -1ULL;
+		viewer_stream->fd = -1;
+		index->offset = EOF;
+		break;
+	case LTTNG_VIEWER_INDEX_ERR:
+		fprintf(stderr, "[error] get_next_index: error\n");
+		ret = -1;
+		goto error;
+	default:
+		fprintf(stderr, "[error] get_next_index: unkwown value\n");
+		ret = -1;
+		goto error;
+	}
+
+	ret = 0;
+
+error:
+	return ret;
+}
+
+void ctf_live_packet_seek(struct bt_stream_pos *stream_pos, size_t index,
+		int whence)
+{
+	struct ctf_stream_pos *pos;
+	struct ctf_file_stream *file_stream;
+	struct packet_index packet_index;
+	struct lttng_live_viewer_stream *viewer_stream;
+	struct lttng_live_session *session;
+	int ret;
+
+retry:
+	pos = ctf_pos(stream_pos);
+	file_stream = container_of(pos, struct ctf_file_stream, pos);
+	viewer_stream = (struct lttng_live_viewer_stream *) pos->priv;
+	session = viewer_stream->session;
+
+	printf_verbose("get_next_index for stream %" PRIu64 "\n", viewer_stream->id);
+	ret = get_next_index(session->ctx, viewer_stream, &packet_index);
+	if (ret < 0) {
+		pos->offset = EOF;
+		fprintf(stderr, "[error] get_next_index failed\n");
+		return;
+	}
+
+	pos->packet_size = packet_index.packet_size;
+	pos->content_size = packet_index.content_size;
+	pos->mmap_base_offset = 0;
+	if (packet_index.offset == EOF) {
+		pos->offset = EOF;
+	} else {
+		pos->offset = 0;
+	}
+
+	if (packet_index.content_size == 0) {
+		file_stream->parent.cycles_timestamp = packet_index.timestamp_end;
+		file_stream->parent.real_timestamp = ctf_get_real_timestamp(
+				&file_stream->parent, packet_index.timestamp_end);
+	} else {
+		file_stream->parent.cycles_timestamp = packet_index.timestamp_begin;
+		file_stream->parent.real_timestamp = ctf_get_real_timestamp(
+				&file_stream->parent, packet_index.timestamp_begin);
+	}
+
+	if (pos->packet_size == 0 || pos->offset == EOF) {
+		goto end;
+	}
+
+	printf_verbose("get_data_packet for stream %" PRIu64 "\n",
+			viewer_stream->id);
+	ret = get_data_packet(session->ctx, pos, viewer_stream,
+			be64toh(packet_index.offset),
+			packet_index.packet_size / CHAR_BIT);
+	if (ret == -2) {
+		goto retry;
+	} else if (ret < 0) {
+		pos->offset = EOF;
+		fprintf(stderr, "[error] get_data_packet failed\n");
+		return;
+	}
+
+	printf_verbose("Index received : packet_size : %" PRIu64
+			", offset %" PRIu64 ", content_size %" PRIu64
+			", timestamp_end : %" PRIu64 "\n",
+			packet_index.packet_size, packet_index.offset,
+			packet_index.content_size, packet_index.timestamp_end);
+
+	/* update trace_packet_header and stream_packet_context */
+	if (pos->prot != PROT_WRITE && file_stream->parent.trace_packet_header) {
+		/* Read packet header */
+		ret = generic_rw(&pos->parent, &file_stream->parent.trace_packet_header->p);
+		if (ret) {
+			pos->offset = EOF;
+			fprintf(stderr, "[error] trace packet header read failed\n");
+			goto end;
+		}
+	}
+	if (pos->prot != PROT_WRITE && file_stream->parent.stream_packet_context) {
+		/* Read packet context */
+		ret = generic_rw(&pos->parent, &file_stream->parent.stream_packet_context->p);
+		if (ret) {
+			pos->offset = EOF;
+			fprintf(stderr, "[error] stream packet context read failed\n");
+			goto end;
+		}
+	}
+	pos->data_offset = pos->offset;
+
+end:
+	return;
+}
+
+static int del_traces(gpointer key, gpointer value, gpointer user_data)
+{
+	struct bt_context *bt_ctx = user_data;
+	struct lttng_live_ctf_trace *trace = value;
+	int ret;
+
+	ret = bt_context_remove_trace(bt_ctx, trace->trace_id);
+	if (ret < 0)
+		fprintf(stderr, "[error] removing trace from context\n");
+
+	/* remove the key/value pair from the HT. */
+	return 1;
+}
+
+static void add_traces(gpointer key, gpointer value, gpointer user_data)
+{
+	int i, ret, total_metadata = 0;
+	uint64_t metadata_len;
+	struct bt_context *bt_ctx = user_data;
+	struct lttng_live_ctf_trace *trace = value;
+	struct lttng_live_viewer_stream *stream;
+	struct bt_mmap_stream *new_mmap_stream;
+	struct bt_mmap_stream_list mmap_list;
+	struct lttng_live_ctx *ctx = NULL;
+
+	BT_INIT_LIST_HEAD(&mmap_list.head);
+
+	for (i = 0; i < trace->streams->len; i++) {
+		stream = g_ptr_array_index(trace->streams, i);
+		ctx = stream->session->ctx;
+
+		if (!stream->metadata_flag) {
+			new_mmap_stream = zmalloc(sizeof(struct bt_mmap_stream));
+			new_mmap_stream->priv = (void *) stream;
+			new_mmap_stream->fd = -1;
+			bt_list_add(&new_mmap_stream->list, &mmap_list.head);
+		} else {
+			/* Get all possible metadata before starting */
+			do {
+				ret = get_new_metadata(ctx, stream,
+						&metadata_len);
+				if (ret == 0) {
+					total_metadata += metadata_len;
+				}
+			} while (ret == 0 || total_metadata == 0);
+			trace->metadata_fp = fopen(stream->path, "r");
+		}
+	}
+
+	if (!trace->metadata_fp) {
+		fprintf(stderr, "[error] No metadata stream opened\n");
+		goto end_free;
+	}
+
+	ret = bt_context_add_trace(bt_ctx, NULL, "ctf",
+			ctf_live_packet_seek, &mmap_list, trace->metadata_fp);
+	if (ret < 0) {
+		fprintf(stderr, "[error] Error adding trace\n");
+		goto end_free;
+	}
+	trace->trace_id = ret;
+
+	goto end;
+
+end_free:
+	bt_context_put(bt_ctx);
+end:
+	return;
+}
+
+void lttng_live_read(struct lttng_live_ctx *ctx, uint64_t session_id)
+{
+	int ret, active_session = 0;
+	struct bt_context *bt_ctx;
+
+	bt_ctx = bt_context_create();
+	if (!bt_ctx) {
+		fprintf(stderr, "[error] bt_context_create allocation\n");
+		goto end;
+	}
+
+	/*
+	 * As long as the session is active, we try to reattach to it,
+	 * even if all the streams get closed.
+	 */
+//	do {
+		do {
+			ret = lttng_live_attach_session(ctx, session_id);
+			printf_verbose("Attaching session returns %d\n", ret);
+			if (ret < 0) {
+				if (ret == -LTTNG_VIEWER_ATTACH_UNK) {
+					if (active_session)
+						goto end_free;
+					fprintf(stderr, "[error] Unknown "
+							"session ID\n");
+				}
+				goto end_free;
+			} else {
+				active_session = 1;
+			}
+		} while (ctx->session->stream_count == 0);
+
+		g_hash_table_foreach(ctx->session->ctf_traces, add_traces, bt_ctx);
+
+		ret = check_requirements(bt_ctx);
+		if (ret < 0) {
+			fprintf(stderr, "[error] some mandatory contexts "
+					"were missing, exiting.\n");
+			goto end;
+		}
+
+		if (!opt_textdump) {
+			pthread_create(&display_thread, NULL, ncurses_display,
+					(void *) NULL);
+			pthread_create(&timer_thread, NULL, refresh_thread,
+					(void *) NULL);
+		}
+
+		iter_trace(bt_ctx);
+
+		g_hash_table_foreach_remove(ctx->session->ctf_traces, del_traces, bt_ctx);
+//	} while (active_session);
+
+end_free:
+	bt_context_put(bt_ctx);
+end:
+	return;
+}