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Subject[PATCH trace-cmd V5 2/6] trace-cmd/listen: Introduce trace-msg protocol (protocol v2)
From
Date
Introduce new trace-msg protocol (protocol V2) for more
flexible messaging. V1 protocol which is currently used
by trace-cmd server and client, is based on a simple
text messages. It is impossible to extend the protocol
without breaking backward compatibility. The V2 protocol
introduced by this patch is a binary message-based protocol
and it is able to extend by just adding message tags.

<How to test>
[1] Backward compatibility checks
We need to test backward compatibility of this patch for old
trace-cmds(client/server). So, this patch was tested for [2]
command checks in following 3 types:

<client> <server>
new old
old new
new new

[2] Command checks
- server (common)
# trace-cmd listen -p 12345

1) record
- client
# trace-cmd record -e sched -N <server IP>:12345
^C

2) record + multiple buffers
- client
# trace-cmd record -B foo -e sched -N <server IP>:12345
^C

3) extract
- client
# ./trace-cmd start -e sched
# sleep 5
# ./trace-cmd stop
# ./trace-cmd extract -N <server IP>:12345

4) extract + snapshot
- client
# ./trace-cmd start -e sched
# sleep 5
# ./trace-cmd snapshot -s
# ./trace-cmd stop
# ./trace-cmd extract -N <server IP>:12345 -s

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

---
Changes in V5: Client sends "-1V2\0<MAGIC_NUMBER>\00" instead of
"V2\0<MAGIC_NUMBER>\0" not to make old server create
zero length file.
Also add a protocol documentation.
Cleanup source code.
Change meaningless loop in tracecmd_msg_collect_metadata().
Changes in V4: Fix some typos, cleanups and rebase for current trace-cmd-v2.4
Change the argument of tracecmd_msg_recv()
Changes in V3: Change the license of trace-msg.c to LGPL v2.1
Changes in V2: Regacy protocol support in order to keep backward compatibility
---
Documentation/Protocol.txt | 119 ++++++++
Makefile | 2
trace-cmd.h | 11 +
trace-listen.c | 84 ++++-
trace-msg.c | 682 ++++++++++++++++++++++++++++++++++++++++++++
trace-msg.h | 27 ++
trace-output.c | 4
trace-record.c | 91 +++++-
8 files changed, 980 insertions(+), 40 deletions(-)
create mode 100644 Documentation/Protocol.txt
create mode 100644 trace-msg.c
create mode 100644 trace-msg.h

diff --git a/Documentation/Protocol.txt b/Documentation/Protocol.txt
new file mode 100644
index 0000000..49f7766
--- /dev/null
+++ b/Documentation/Protocol.txt
@@ -0,0 +1,119 @@
+Trace-cmd Protocols
+===================
+
+Index
+=====
+1. What is the trace-cmd protocol?
+2. Trace-cmd Protocol V1 (Obsolete)
+3. Trace-cmd Protocol V2
+
+
+1. What is the trace-cmd protocol?
+==================================
+ Trace-cmd can run as a remote-trace agent(server) and a client, which
+communicate over network and passing the trace data. Trace-cmd protocol
+is used for the communication between the server and the client.
+ There are 2 versions of the trace-cmd protocol. V1 protocol was simple
+text-based but hard to extend. On the other hand, V2 protocol is message
+based and extensible.
+
+
+2. Trace-cmd Protocol V1 (Obsolete)
+========================
+
+The old trace-cmd which supports V1 protocol works as follows;
+
+ <server(local)> <client(remote)>
+ listen to socket fd
+ connect to socket fd
+ accept the client
+ send "tracecmd"
+ +------------> receive "tracecmd"
+ check "tracecmd"
+ send cpus
+ receive cpus <------------+
+ print "cpus=XXX"
+ send pagesize
+ |
+ receive pagesize <--------+
+ print "pagesize=XXX"
+ send options
+ |
+ receive options <---------+
+ understand options
+ send port_array
+ +------------> receive port_array
+ understand port_array
+ send meta data
+ receive meta data <-------+
+ record meta data
+ (snip)
+ read block
+ --- start sending trace data on child processes ---
+
+ --- When client finishes sending trace data ---
+ close(socket fd)
+ read size = 0
+ close(socket fd)
+
+All messages are unstructured character strings and the messaging
+order and contents are fixed. It is impossible to extend the
+protocol without breaking the compatibility.
+
+
+3. Trace-cmd Protocol V2
+========================
+
+From the protocol V2, the structured binary message "trace-msg" is
+introduced as the communication protocol.
+
+ <server> <client>
+ listen to socket fd
+ connect to socket fd
+ accept the client
+ send "tracecmd"
+ +------------> receive "tracecmd"
+ check "tracecmd"
+ send "-1V2\0<MAGIC_NUMBER>\0" as the v2 protocol
+ receive "-1V2" <----------+
+ check "-1V2"
+ check <MAGIC_NUMBER>
+ send "V2"
+ +---------------> receive "V2"
+ check "V2"
+ send MSG_TINIT with cpus, pagesize and options
+ receive MSG_TINIT <-------+
+ perse the parameters
+ send MSG_RINIT with port_array
+ +----------------> receive MSG_RINIT
+ get port_array
+ send meta data(MSG_SENDMETA)
+ receive MSG_SENDMETA <----+
+ record meta data
+ (snip)
+ send a message to finish sending meta data
+ | (MSG_FINMETA)
+ receive MSG_FINMETA <-----+
+ read block
+ --- start sending trace data on child processes ---
+
+ --- When client finishes sending trace data ---
+ send MSG_CLOSE
+ receive MSG_CLOSE <-------+
+ close(socket fd) close(socket fd)
+
+In this version, after the client checks "tracecmd", it sends
+"-1V2\0<MAGIC_NUMBER>\0". This is for the backward compatibility.
+When the newer client tries to connect to the old server and sends
+this string to the server, the old server parses it to get the
+number of CPUs. Since "-1V2" actually becomes -1 and this is a
+wrong value, the server refuses the client. Then, the client gets
+a connection error because the server is old, so it can try to
+connect with V1 protocol again.
+
+On the other hand, if new server gets a connection from an old
+client, it can easily check whether the client uses V1 protocol
+or not by checking the first message from the client. If client
+sends a positive number, it should be a V1 protocol client.
+
+
diff --git a/Makefile b/Makefile
index cbe0eb9..9977528 100644
--- a/Makefile
+++ b/Makefile
@@ -318,7 +318,7 @@ KERNEL_SHARK_OBJS = $(TRACE_VIEW_OBJS) $(TRACE_GRAPH_OBJS) $(TRACE_GUI_OBJS) \
PEVENT_LIB_OBJS = event-parse.o trace-seq.o parse-filter.o parse-utils.o
TCMD_LIB_OBJS = $(PEVENT_LIB_OBJS) trace-util.o trace-input.o trace-ftrace.o \
trace-output.o trace-recorder.o trace-restore.o trace-usage.o \
- trace-blk-hack.o kbuffer-parse.o event-plugin.o
+ trace-blk-hack.o kbuffer-parse.o event-plugin.o trace-msg.o

PLUGIN_OBJS =
PLUGIN_OBJS += plugin_jbd2.o
diff --git a/trace-cmd.h b/trace-cmd.h
index 92b4ff2..f65f29e 100644
--- a/trace-cmd.h
+++ b/trace-cmd.h
@@ -248,6 +248,17 @@ void tracecmd_stop_recording(struct tracecmd_recorder *recorder);
void tracecmd_stat_cpu(struct trace_seq *s, int cpu);
long tracecmd_flush_recording(struct tracecmd_recorder *recorder);

+/* for clients */
+int tracecmd_msg_send_init_data(int fd);
+int tracecmd_msg_metadata_send(int fd, char *buf, int size);
+int tracecmd_msg_finish_sending_metadata(int fd);
+void tracecmd_msg_send_close_msg(void);
+
+/* for server */
+int tracecmd_msg_initial_setting(int fd, int *cpus, int *pagesize);
+int tracecmd_msg_send_port_array(int fd, int total_cpus, int *ports);
+int tracecmd_msg_collect_metadata(int ifd, int ofd);
+
/* --- Plugin handling --- */
extern struct plugin_option trace_ftrace_options[];

diff --git a/trace-listen.c b/trace-listen.c
index 18672b0..17ab184 100644
--- a/trace-listen.c
+++ b/trace-listen.c
@@ -33,6 +33,7 @@
#include <errno.h>

#include "trace-local.h"
+#include "trace-msg.h"

#define MAX_OPTION_SIZE 4096

@@ -45,10 +46,10 @@ static FILE *logfp;

static int debug;

-static int use_tcp;
-
static int backlog = 5;

+static int proto_ver;
+
#define TEMP_FILE_STR "%s.%s:%s.cpu%d", output_file, host, port, cpu
static char *get_temp_file(const char *host, const char *port, int cpu)
{
@@ -112,7 +113,6 @@ static int process_option(char *option)
return 0;
}

-static int done;
static void finish(int sig)
{
done = 1;
@@ -144,7 +144,7 @@ static void __plog(const char *prefix, const char *fmt, va_list ap,
fprintf(fp, "%.*s", r, buf);
}

-static void plog(const char *fmt, ...)
+void plog(const char *fmt, ...)
{
va_list ap;

@@ -153,7 +153,7 @@ static void plog(const char *fmt, ...)
va_end(ap);
}

-static void pdie(const char *fmt, ...)
+void pdie(const char *fmt, ...)
{
va_list ap;
char *str = "";
@@ -305,25 +305,15 @@ static int open_udp(const char *node, const char *port, int *pid,
return num_port;
}

-static int communicate_with_client(int fd, int *cpus, int *pagesize)
+/* Setup client who is using the v1 protocol */
+static int client_initial_setting(int fd, char *buf, int *cpus, int *pagesize)
{
- char buf[BUFSIZ];
char *option;
int options;
int size;
int n, s, t, i;

- /* Let the client know what we are */
- write(fd, "tracecmd", 8);
-
- /* read back the CPU count */
- n = read_string(fd, buf, BUFSIZ);
- if (n == BUFSIZ)
- /** ERROR **/
- return -1;
-
*cpus = atoi(buf);
-
plog("cpus=%d\n", *cpus);
if (*cpus < 0)
return -1;
@@ -376,6 +366,41 @@ static int communicate_with_client(int fd, int *cpus, int *pagesize)
return -1;
}

+ return 0;
+}
+
+static int communicate_with_client(int fd, int *cpus, int *pagesize)
+{
+ char buf[BUFSIZ];
+ int n;
+
+ /* Let the client know what we are */
+ write(fd, "tracecmd", 8);
+
+ /* read back the CPU count */
+ n = read_string(fd, buf, BUFSIZ);
+ if (n == BUFSIZ)
+ /** ERROR **/
+ return -1;
+
+ /* Is the client using the new protocol? */
+ if (memcmp(buf, "-1V2", 4) == 0) {
+ read(fd, buf, sizeof(V2_MAGIC));
+ if (memcmp(buf, V2_MAGIC, strlen(V2_MAGIC)) != 0) {
+ plog("Invalid magic number %s", buf);
+ return -1;
+ }
+ proto_ver = V2_PROTOCOL;
+
+ /* Let the client know we use v2 protocol */
+ write(fd, "V2", 2);
+
+ /* read the CPU count, the page size, and options */
+ if (tracecmd_msg_initial_setting(fd, cpus, pagesize) < 0)
+ return -1;
+ } else if (client_initial_setting(fd, buf, cpus, pagesize) < 0)
+ return -1;
+
if (use_tcp)
plog("Using TCP for live connection\n");

@@ -442,14 +467,20 @@ static int *create_all_readers(int cpus, const char *node, const char *port,
start_port = udp_port + 1;
}

- /* send the client a comma deliminated set of port numbers */
- for (cpu = 0; cpu < cpus; cpu++) {
- snprintf(buf, BUFSIZ, "%s%d",
- cpu ? "," : "", port_array[cpu]);
- write(fd, buf, strlen(buf));
+ if (proto_ver == V2_PROTOCOL) {
+ /* send set of port numbers to the client */
+ if (tracecmd_msg_send_port_array(fd, cpus, port_array) < 0)
+ goto out_free;
+ } else {
+ /* send the client a comma deliminated set of port numbers */
+ for (cpu = 0; cpu < cpus; cpu++) {
+ snprintf(buf, BUFSIZ, "%s%d",
+ cpu ? "," : "", port_array[cpu]);
+ write(fd, buf, strlen(buf));
+ }
+ /* end with null terminator */
+ write(fd, "\0", 1);
}
- /* end with null terminator */
- write(fd, "\0", 1);

return pid_array;

@@ -528,7 +559,10 @@ static void process_client(const char *node, const char *port, int fd)
return;

/* Now we are ready to start reading data from the client */
- collect_metadata_from_client(fd, ofd);
+ if (proto_ver == V2_PROTOCOL)
+ tracecmd_msg_collect_metadata(fd, ofd);
+ else
+ collect_metadata_from_client(fd, ofd);

/* wait a little to let our readers finish reading */
sleep(1);
diff --git a/trace-msg.c b/trace-msg.c
new file mode 100644
index 0000000..a97222c
--- /dev/null
+++ b/trace-msg.c
@@ -0,0 +1,682 @@
+/*
+ * trace-msg.c : define message protocol for communication between clients and
+ * a server
+ *
+ * Copyright (C) 2013 Hitachi, Ltd.
+ * Created by Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License (not later!)
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, see <http://www.gnu.org/licenses>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <errno.h>
+#include <poll.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/types.h>
+#include <linux/types.h>
+
+#include "trace-cmd-local.h"
+#include "trace-msg.h"
+
+typedef __u32 u32;
+typedef __be32 be32;
+
+#define TRACECMD_MSG_MAX_LEN BUFSIZ
+
+ /* size + cmd */
+#define TRACECMD_MSG_HDR_LEN ((sizeof(be32)) + (sizeof(be32)))
+
+ /* + size of the metadata */
+#define TRACECMD_MSG_META_MIN_LEN \
+ ((TRACECMD_MSG_HDR_LEN) + (sizeof(be32)))
+
+ /* - header size for error msg */
+#define TRACECMD_MSG_META_MAX_LEN \
+((TRACECMD_MSG_MAX_LEN) - (TRACECMD_MSG_META_MIN_LEN) - TRACECMD_MSG_HDR_LEN)
+
+ /* size + opt_cmd + size of str */
+#define TRACECMD_OPT_MIN_LEN \
+ ((sizeof(be32)) + (sizeof(be32)) + (sizeof(be32)))
+
+
+#define CPU_MAX 256
+
+/* for both client and server */
+bool use_tcp;
+int cpu_count;
+
+/* for client */
+static int psfd;
+unsigned int page_size;
+int *client_ports;
+bool send_metadata;
+
+/* for server */
+static int *port_array;
+bool done;
+
+struct tracecmd_msg_str {
+ be32 size;
+ char *buf;
+} __attribute__((packed));
+
+struct tracecmd_msg_opt {
+ be32 size;
+ be32 opt_cmd;
+ struct tracecmd_msg_str str;
+};
+
+struct tracecmd_msg_tinit {
+ be32 cpus;
+ be32 page_size;
+ be32 opt_num;
+ struct tracecmd_msg_opt *opt;
+} __attribute__((packed));
+
+struct tracecmd_msg_rinit {
+ be32 cpus;
+ be32 port_array[CPU_MAX];
+} __attribute__((packed));
+
+struct tracecmd_msg_meta {
+ struct tracecmd_msg_str str;
+};
+
+struct tracecmd_msg_error {
+ be32 size;
+ be32 cmd;
+ union {
+ struct tracecmd_msg_tinit tinit;
+ struct tracecmd_msg_rinit rinit;
+ struct tracecmd_msg_meta meta;
+ } data;
+} __attribute__((packed));
+
+enum tracecmd_msg_cmd {
+ MSG_CLOSE = 1,
+ MSG_TINIT = 4,
+ MSG_RINIT = 5,
+ MSG_SENDMETA = 6,
+ MSG_FINMETA = 7,
+};
+
+struct tracecmd_msg {
+ be32 size;
+ be32 cmd;
+ union {
+ struct tracecmd_msg_tinit tinit;
+ struct tracecmd_msg_rinit rinit;
+ struct tracecmd_msg_meta meta;
+ struct tracecmd_msg_error err;
+ } data;
+} __attribute__((packed));
+
+struct tracecmd_msg *errmsg;
+
+static ssize_t msg_do_write_check(int fd, struct tracecmd_msg *msg)
+{
+ return __do_write_check(fd, msg, ntohl(msg->size));
+}
+
+static void tracecmd_msg_init(u32 cmd, u32 len, struct tracecmd_msg *msg)
+{
+ memset(msg, 0, len);
+ msg->size = htonl(len);
+ msg->cmd = htonl(cmd);
+}
+
+static int tracecmd_msg_alloc(u32 cmd, u32 len, struct tracecmd_msg **msg)
+{
+ len += TRACECMD_MSG_HDR_LEN;
+ *msg = malloc(len);
+ if (!*msg)
+ return -ENOMEM;
+
+ tracecmd_msg_init(cmd, len, *msg);
+ return 0;
+}
+
+static void bufcpy(void *dest, u32 offset, const void *buf, u32 buflen)
+{
+ memcpy(dest+offset, buf, buflen);
+}
+
+enum msg_opt_command {
+ MSGOPT_USETCP = 1,
+};
+
+static int add_option_to_tinit(u32 cmd, const char *buf,
+ struct tracecmd_msg *msg, int offset)
+{
+ struct tracecmd_msg_opt *opt;
+ u32 len = TRACECMD_OPT_MIN_LEN;
+ u32 buflen = 0;
+
+ if (buf) {
+ buflen = strlen(buf);
+ len += buflen;
+ }
+
+ opt = malloc(len);
+ if (!opt)
+ return -ENOMEM;
+
+ opt->size = htonl(len);
+ opt->opt_cmd = htonl(cmd);
+ opt->str.size = htonl(buflen);
+
+ if (buf)
+ bufcpy(opt, TRACECMD_OPT_MIN_LEN, buf, buflen);
+
+ /* add option to msg */
+ bufcpy(msg, offset, opt, ntohl(opt->size));
+
+ free(opt);
+ return len;
+}
+
+static int add_options_to_tinit(struct tracecmd_msg *msg)
+{
+ int offset = offsetof(struct tracecmd_msg, data.tinit.opt);
+ int ret;
+
+ if (use_tcp) {
+ ret = add_option_to_tinit(MSGOPT_USETCP, NULL, msg, offset);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int make_tinit(struct tracecmd_msg *msg)
+{
+ int opt_num = 0;
+ int ret = 0;
+
+ if (use_tcp)
+ opt_num++;
+
+ if (opt_num) {
+ ret = add_options_to_tinit(msg);
+ if (ret < 0)
+ return ret;
+ }
+
+ msg->data.tinit.cpus = htonl(cpu_count);
+ msg->data.tinit.page_size = htonl(page_size);
+ msg->data.tinit.opt_num = htonl(opt_num);
+
+ return 0;
+}
+
+static int make_rinit(struct tracecmd_msg *msg)
+{
+ int i;
+ u32 offset = TRACECMD_MSG_HDR_LEN;
+ be32 port;
+
+ msg->data.rinit.cpus = htonl(cpu_count);
+
+ for (i = 0; i < cpu_count; i++) {
+ /* + rrqports->cpus or rrqports->port_array[i] */
+ offset += sizeof(be32);
+ port = htonl(port_array[i]);
+ bufcpy(msg, offset, &port, sizeof(be32) * cpu_count);
+ }
+
+ return 0;
+}
+
+static u32 tracecmd_msg_get_body_length(u32 cmd)
+{
+ struct tracecmd_msg *msg;
+ u32 len = 0;
+
+ switch (cmd) {
+ case MSG_TINIT:
+ len = sizeof(msg->data.tinit.cpus)
+ + sizeof(msg->data.tinit.page_size)
+ + sizeof(msg->data.tinit.opt_num);
+
+ /*
+ * If we are using IPV4 and our page size is greater than
+ * or equal to 64K, we need to punt and use TCP. :-(
+ */
+
+ /* TODO, test for ipv4 */
+ if (page_size >= UDP_MAX_PACKET) {
+ warning("page size too big for UDP using TCP in live read");
+ use_tcp = true;
+ }
+
+ if (use_tcp)
+ len += TRACECMD_OPT_MIN_LEN;
+
+ return len;
+ case MSG_RINIT:
+ return sizeof(msg->data.rinit.cpus)
+ + sizeof(msg->data.rinit.port_array);
+ case MSG_SENDMETA:
+ return TRACECMD_MSG_MAX_LEN - TRACECMD_MSG_HDR_LEN;
+ case MSG_CLOSE:
+ case MSG_FINMETA:
+ break;
+ }
+
+ return 0;
+}
+
+static int tracecmd_msg_make_body(u32 cmd, struct tracecmd_msg *msg)
+{
+ switch (cmd) {
+ case MSG_TINIT:
+ return make_tinit(msg);
+ case MSG_RINIT:
+ return make_rinit(msg);
+ case MSG_CLOSE:
+ case MSG_SENDMETA: /* meta data is not stored here. */
+ case MSG_FINMETA:
+ break;
+ }
+
+ return 0;
+}
+
+static int tracecmd_msg_create(u32 cmd, struct tracecmd_msg **msg)
+{
+ u32 len = 0;
+ int ret = 0;
+
+ len = tracecmd_msg_get_body_length(cmd);
+ if (len > (TRACECMD_MSG_MAX_LEN - TRACECMD_MSG_HDR_LEN)) {
+ plog("Exceed maximum message size cmd=%d\n", cmd);
+ return -EINVAL;
+ }
+
+ ret = tracecmd_msg_alloc(cmd, len, msg);
+ if (ret < 0)
+ return ret;
+
+ ret = tracecmd_msg_make_body(cmd, *msg);
+ if (ret < 0)
+ free(*msg);
+
+ return ret;
+}
+
+static int tracecmd_msg_send(int fd, u32 cmd)
+{
+ struct tracecmd_msg *msg = NULL;
+ int ret = 0;
+
+ if (cmd > MSG_FINMETA) {
+ plog("Unsupported command: %d\n", cmd);
+ return -EINVAL;
+ }
+
+ ret = tracecmd_msg_create(cmd, &msg);
+ if (ret < 0)
+ return ret;
+
+ ret = msg_do_write_check(fd, msg);
+ if (ret < 0)
+ ret = -ECOMM;
+
+ free(msg);
+ return ret;
+}
+
+static int tracecmd_msg_read_extra(int fd, void *buf, u32 size, int *n)
+{
+ int r = 0;
+
+ do {
+ r = read(fd, buf + *n, size);
+ if (r < 0) {
+ if (errno == EINTR)
+ continue;
+ return -errno;
+ } else if (!r)
+ return -ENOTCONN;
+ size -= r;
+ *n += r;
+ } while (size);
+
+ return 0;
+}
+
+/*
+ * Read header information of msg first, then read all data
+ */
+static int tracecmd_msg_recv(int fd, struct tracecmd_msg *msg)
+{
+ u32 size = 0;
+ int n = 0;
+ int ret;
+
+ ret = tracecmd_msg_read_extra(fd, msg, TRACECMD_MSG_HDR_LEN, &n);
+ if (ret < 0)
+ return ret;
+
+ size = ntohl(msg->size);
+ if (size > TRACECMD_MSG_MAX_LEN)
+ /* too big */
+ goto error;
+ else if (size < TRACECMD_MSG_HDR_LEN)
+ /* too small */
+ goto error;
+ else if (size > TRACECMD_MSG_HDR_LEN) {
+ size -= TRACECMD_MSG_HDR_LEN;
+ return tracecmd_msg_read_extra(fd, msg, size, &n);
+ }
+
+ return 0;
+error:
+ plog("Receive an invalid message(size=%d)\n", size);
+ return -ENOMSG;
+}
+
+static void *tracecmd_msg_buf_access(struct tracecmd_msg *msg, int offset)
+{
+ return (void *)msg + offset;
+}
+
+static int tracecmd_msg_wait_for_msg(int fd, struct tracecmd_msg *msg)
+{
+ u32 cmd;
+ int ret;
+
+ ret = tracecmd_msg_recv(fd, msg);
+ if (ret < 0)
+ return ret;
+
+ cmd = ntohl(msg->cmd);
+ if (cmd == MSG_CLOSE)
+ return -ECONNABORTED;
+
+ return 0;
+}
+
+static int tracecmd_msg_send_and_wait_for_msg(int fd, u32 cmd, struct tracecmd_msg *msg)
+{
+ int ret;
+
+ ret = tracecmd_msg_send(fd, cmd);
+ if (ret < 0)
+ return ret;
+
+ ret = tracecmd_msg_wait_for_msg(fd, msg);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+int tracecmd_msg_send_init_data(int fd)
+{
+ char buf[TRACECMD_MSG_MAX_LEN];
+ struct tracecmd_msg *msg;
+ int i, cpus;
+ int ret;
+
+ msg = (struct tracecmd_msg *)buf;
+ ret = tracecmd_msg_send_and_wait_for_msg(fd, MSG_TINIT, msg);
+ if (ret < 0)
+ return ret;
+
+ cpus = ntohl(msg->data.rinit.cpus);
+ client_ports = malloc_or_die(sizeof(int) * cpus);
+ for (i = 0; i < cpus; i++)
+ client_ports[i] = ntohl(msg->data.rinit.port_array[i]);
+
+ /* Next, send meta data */
+ send_metadata = true;
+
+ return 0;
+}
+
+static bool process_option(struct tracecmd_msg_opt *opt)
+{
+ /* currently the only option we have is to us TCP */
+ if (ntohl(opt->opt_cmd) == MSGOPT_USETCP) {
+ use_tcp = true;
+ return true;
+ }
+ return false;
+}
+
+static void error_operation_for_server(struct tracecmd_msg *msg)
+{
+ u32 cmd;
+
+ cmd = ntohl(msg->cmd);
+
+ warning("Message: cmd=%d size=%d\n", cmd, ntohl(msg->size));
+}
+
+#define MAX_OPTION_SIZE 4096
+
+int tracecmd_msg_initial_setting(int fd, int *cpus, int *pagesize)
+{
+ struct tracecmd_msg *msg;
+ struct tracecmd_msg_opt *opt;
+ char buf[TRACECMD_MSG_MAX_LEN];
+ int offset = offsetof(struct tracecmd_msg, data.tinit.opt);
+ int options, i, s;
+ int ret;
+ u32 size = 0;
+ u32 cmd;
+
+ msg = (struct tracecmd_msg *)buf;
+ ret = tracecmd_msg_recv(fd, msg);
+ if (ret < 0)
+ return ret;
+
+ cmd = ntohl(msg->cmd);
+ if (cmd != MSG_TINIT) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ *cpus = ntohl(msg->data.tinit.cpus);
+ plog("cpus=%d\n", *cpus);
+ if (*cpus < 0) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ *pagesize = ntohl(msg->data.tinit.page_size);
+ plog("pagesize=%d\n", *pagesize);
+ if (*pagesize <= 0) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ options = ntohl(msg->data.tinit.opt_num);
+ for (i = 0; i < options; i++) {
+ offset += size;
+ opt = tracecmd_msg_buf_access(msg, offset);
+ size = ntohl(opt->size);
+ /* prevent a client from killing us */
+ if (size > MAX_OPTION_SIZE) {
+ plog("Exceed MAX_OPTION_SIZE\n");
+ ret = -EINVAL;
+ goto error;
+ }
+ s = process_option(opt);
+ /* do we understand this option? */
+ if (!s) {
+ plog("Cannot understand(%d:%d:%d)\n",
+ i, ntohl(opt->size), ntohl(opt->opt_cmd));
+ ret = -EINVAL;
+ goto error;
+ }
+ }
+
+ return 0;
+
+error:
+ error_operation_for_server(msg);
+ return ret;
+}
+
+int tracecmd_msg_send_port_array(int fd, int total_cpus, int *ports)
+{
+ int ret;
+
+ cpu_count = total_cpus;
+ port_array = ports;
+
+ ret = tracecmd_msg_send(fd, MSG_RINIT);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+void tracecmd_msg_send_close_msg(void)
+{
+ tracecmd_msg_send(psfd, MSG_CLOSE);
+}
+
+static void make_meta(const char *buf, int buflen, struct tracecmd_msg *msg)
+{
+ int offset = offsetof(struct tracecmd_msg, data.meta.str.buf);
+
+ msg->data.meta.str.size = htonl(buflen);
+ bufcpy(msg, offset, buf, buflen);
+}
+
+int tracecmd_msg_metadata_send(int fd, char *buf, int size)
+{
+ struct tracecmd_msg *msg;
+ int n, len;
+ int ret;
+ int count = 0;
+
+ ret = tracecmd_msg_create(MSG_SENDMETA, &msg);
+ if (ret < 0)
+ return ret;
+
+ n = size;
+ do {
+ if (n > TRACECMD_MSG_META_MAX_LEN) {
+ make_meta(buf+count, TRACECMD_MSG_META_MAX_LEN, msg);
+ n -= TRACECMD_MSG_META_MAX_LEN;
+ count += TRACECMD_MSG_META_MAX_LEN;
+ } else {
+ make_meta(buf+count, n, msg);
+ /*
+ * TRACECMD_MSG_META_MAX_LEN is stored in msg->size,
+ * so update the size to the correct value.
+ */
+ len = TRACECMD_MSG_META_MIN_LEN + n;
+ msg->size = htonl(len);
+ n = 0;
+ }
+
+ ret = msg_do_write_check(fd, msg);
+ if (ret < 0)
+ break;
+ } while (n);
+
+ free(msg);
+ return ret;
+}
+
+int tracecmd_msg_finish_sending_metadata(int fd)
+{
+ int ret;
+
+ ret = tracecmd_msg_send(fd, MSG_FINMETA);
+ if (ret < 0)
+ return ret;
+
+ /* psfd will be used for closing */
+ psfd = fd;
+ return 0;
+}
+
+int tracecmd_msg_collect_metadata(int ifd, int ofd)
+{
+ struct tracecmd_msg *msg;
+ char buf[TRACECMD_MSG_MAX_LEN];
+ u32 s, t, n, cmd;
+ int offset = TRACECMD_MSG_META_MIN_LEN;
+ int ret;
+
+ msg = (struct tracecmd_msg *)buf;
+
+ do {
+ ret = tracecmd_msg_recv(ifd, msg);
+ if (ret < 0) {
+ warning("reading client");
+ return ret;
+ }
+
+ cmd = ntohl(msg->cmd);
+ if (cmd == MSG_FINMETA) {
+ /* Finish receiving meta data */
+ break;
+ } else if (cmd != MSG_SENDMETA)
+ goto error;
+
+ n = ntohl(msg->data.meta.str.size);
+ t = n;
+ s = 0;
+ do {
+ s = write(ofd, buf+s+offset, t);
+ if (s < 0) {
+ if (errno == EINTR)
+ continue;
+ warning("writing to file");
+ return -errno;
+ }
+ t -= s;
+ s = n - t;
+ } while (t);
+ } while (!done);
+
+ /* check the finish message of the client */
+ if (!done) {
+ ret = tracecmd_msg_recv(ifd, msg);
+ if (ret < 0) {
+ warning("reading client");
+ return ret;
+ }
+
+ msg = (struct tracecmd_msg *)buf;
+ cmd = ntohl(msg->cmd);
+ if (cmd != MSG_CLOSE) {
+ warning("Not accept the message %d", ntohl(msg->cmd));
+ ret = -EINVAL;
+ goto error;
+ }
+ /* Finish this connection */
+ }
+
+ return 0;
+
+error:
+ error_operation_for_server(msg);
+ return ret;
+}
diff --git a/trace-msg.h b/trace-msg.h
new file mode 100644
index 0000000..b23e72b
--- /dev/null
+++ b/trace-msg.h
@@ -0,0 +1,27 @@
+#ifndef _TRACE_MSG_H_
+#define _TRACE_MSG_H_
+
+#include <stdbool.h>
+
+#define UDP_MAX_PACKET (65536 - 20)
+#define V2_MAGIC "677768\0"
+
+#define V1_PROTOCOL 1
+#define V2_PROTOCOL 2
+
+/* for both client and server */
+extern bool use_tcp;
+extern int cpu_count;
+
+/* for client */
+extern unsigned int page_size;
+extern int *client_ports;
+extern bool send_metadata;
+
+/* for server */
+extern bool done;
+
+void plog(const char *fmt, ...);
+void pdie(const char *fmt, ...);
+
+#endif /* _TRACE_MSG_H_ */
diff --git a/trace-output.c b/trace-output.c
index b033baa..4661870 100644
--- a/trace-output.c
+++ b/trace-output.c
@@ -37,6 +37,7 @@

#include "trace-cmd-local.h"
#include "list.h"
+#include "trace-msg.h"
#include "version.h"

/* We can't depend on the host size for size_t, all must be 64 bit */
@@ -82,6 +83,9 @@ struct list_event_system {
static stsize_t
do_write_check(struct tracecmd_output *handle, void *data, tsize_t size)
{
+ if (send_metadata)
+ return tracecmd_msg_metadata_send(handle->fd, data, size);
+
return __do_write_check(handle->fd, data, size);
}

diff --git a/trace-record.c b/trace-record.c
index a3a07e1..19711df 100644
--- a/trace-record.c
+++ b/trace-record.c
@@ -45,6 +45,7 @@
#include <errno.h>

#include "trace-local.h"
+#include "trace-msg.h"

#define _STR(x) #x
#define STR(x) _STR(x)
@@ -59,25 +60,17 @@
#define STAMP "stamp"
#define FUNC_STACK_TRACE "func_stack_trace"

-#define UDP_MAX_PACKET (65536 - 20)
-
static int rt_prio;

-static int use_tcp;
-
-static unsigned int page_size;
-
static const char *output_file = "trace.dat";

static int latency;
static int sleep_time = 1000;
-static int cpu_count;
static int recorder_threads;
static int *pids;
static int buffers;

static char *host;
-static int *client_ports;
static int sfd;
static struct tracecmd_output *network_handle;

@@ -99,6 +92,7 @@ static unsigned recorder_flags;
/* Try a few times to get an accurate date */
static int date2ts_tries = 5;

+static int proto_ver = V2_PROTOCOL;
static struct func_list *graph_funcs;

static int func_stack;
@@ -1821,20 +1815,26 @@ static int create_recorder(struct buffer_instance *instance, int cpu, int extrac
exit(0);
}

-static void communicate_with_listener(int fd)
+static void check_first_msg_from_server(int fd)
{
char buf[BUFSIZ];
- ssize_t n;
- int cpu, i;

- n = read(fd, buf, 8);
+ read(fd, buf, 8);

/* Make sure the server is the tracecmd server */
if (memcmp(buf, "tracecmd", 8) != 0)
die("server not tracecmd server");
+}

- /* write the number of CPUs we have (in ASCII) */
+static void communicate_with_listener_v1(int fd)
+{
+ char buf[BUFSIZ];
+ ssize_t n;
+ int cpu, i;
+
+ check_first_msg_from_server(fd);

+ /* write the number of CPUs we have (in ASCII) */
sprintf(buf, "%d", cpu_count);

/* include \0 */
@@ -1889,6 +1889,52 @@ static void communicate_with_listener(int fd)
}
}

+static void communicate_with_listener_v2(int fd)
+{
+ if (tracecmd_msg_send_init_data(fd) < 0)
+ die("Cannot communicate with server");
+}
+
+static void check_protocol_version(int fd)
+{
+ char buf[BUFSIZ];
+ int ret;
+
+ check_first_msg_from_server(fd);
+
+ /*
+ * Write dummy CPU number(-1) in order to make old server not create
+ * zero length file, the protocol version(V2), the magic number,
+ * and the dummy option(0) (in ASCII). The client understands whether
+ * the client uses the v2 protocol or not by checking a reply message
+ * from the server. If the message is "V2", the server uses v2
+ * protocol. On the other hands, if the message is just number strings,
+ * the server returned port numbers. So, in that time, the client
+ * understands the server uses the v1 protocol. However, the old server
+ * tells the client port numbers after reading cpu_count, page_size,
+ * and option. So, we add the dummy number (the magic number and 0
+ * option) to the first client message.
+ */
+ ret = write(fd, "-1V2\0"V2_MAGIC"\0", strlen(V2_MAGIC)+6);
+ if (ret < 0)
+ die("Cannot send initial message");
+
+ /* read a reply message */
+ ret = read(fd, buf, BUFSIZ);
+ if (ret < 0) {
+ if (errno == ECONNRESET) {
+ /* the server uses the v1 protocol, so we'll use it */
+ proto_ver = V1_PROTOCOL;
+ plog("Use the v1 protocol\n");
+ } else
+ die("Cannot read initial message");
+ } else {
+ if (memcmp(buf, "V2", 2) != 0)
+ die("Cannot handle the protocol %s", buf);
+ /* OK, let's use v2 protocol */
+ }
+}
+
static void setup_network(void)
{
struct addrinfo hints;
@@ -1916,6 +1962,7 @@ static void setup_network(void)
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;

+again:
s = getaddrinfo(server, port, &hints, &result);
if (s != 0)
die("getaddrinfo: %s", gai_strerror(s));
@@ -1936,16 +1983,32 @@ static void setup_network(void)

freeaddrinfo(result);

- communicate_with_listener(sfd);
+ if (proto_ver == V2_PROTOCOL) {
+ check_protocol_version(sfd);
+ if (proto_ver == V1_PROTOCOL) {
+ /* reconnect to the server for using the v1 protocol */
+ close(sfd);
+ goto again;
+ }
+ communicate_with_listener_v2(sfd);
+ }
+
+ if (proto_ver == V1_PROTOCOL)
+ communicate_with_listener_v1(sfd);

/* Now create the handle through this socket */
network_handle = tracecmd_create_init_fd_glob(sfd, listed_events);

+ if (proto_ver == V2_PROTOCOL)
+ tracecmd_msg_finish_sending_metadata(sfd);
+
/* OK, we are all set, let'r rip! */
}

static void finish_network(void)
{
+ if (proto_ver == V2_PROTOCOL)
+ tracecmd_msg_send_close_msg();
close(sfd);
free(host);
}



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