From: Slavomir Kaslev <kaslevs@vmware.com>
To: linux-trace-devel@vger.kernel.org
Cc: rostedt@goodmis.org, ykaradzhov@vmware.com, tstoyanov@vmware.com
Subject: [PATCH v4 5/8] trace-cmd: Add TRACE_REQ and TRACE_RESP messages
Date: Wed, 16 Jan 2019 15:43:04 +0200 [thread overview]
Message-ID: <20190116134307.4185-6-kaslevs@vmware.com> (raw)
In-Reply-To: <20190116134307.4185-1-kaslevs@vmware.com>
Add TRACE_REQ and TRACE_RESP messages which are used for initiating guest VM
tracing.
Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
include/trace-cmd/trace-cmd.h | 14 +++
tracecmd/trace-msg.c | 206 +++++++++++++++++++++++++++++++++-
2 files changed, 219 insertions(+), 1 deletion(-)
diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 8b43462..238e16b 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -337,6 +337,20 @@ int tracecmd_msg_collect_data(struct tracecmd_msg_handle *msg_handle, int ofd);
bool tracecmd_msg_done(struct tracecmd_msg_handle *msg_handle);
void tracecmd_msg_set_done(struct tracecmd_msg_handle *msg_handle);
+int tracecmd_msg_send_trace_req(struct tracecmd_msg_handle *msg_handle,
+ int argc, char **argv);
+int tracecmd_msg_recv_trace_req(struct tracecmd_msg_handle *msg_handle,
+ int *argc, char ***argv);
+
+int tracecmd_msg_send_trace_resp(struct tracecmd_msg_handle *msg_handle,
+ int nr_cpus, int page_size,
+ unsigned int *ports);
+int tracecmd_msg_recv_trace_resp(struct tracecmd_msg_handle *msg_handle,
+ int *nr_cpus, int *page_size,
+ unsigned int **ports);
+
+int tracecmd_msg_wait_close(struct tracecmd_msg_handle *msg_handle);
+
/* --- Plugin handling --- */
extern struct tep_plugin_option trace_ftrace_options[];
diff --git a/tracecmd/trace-msg.c b/tracecmd/trace-msg.c
index 529ae2a..46b18aa 100644
--- a/tracecmd/trace-msg.c
+++ b/tracecmd/trace-msg.c
@@ -16,6 +16,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
+#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/types.h>
@@ -79,6 +80,16 @@ struct tracecmd_msg_rinit {
be32 cpus;
} __attribute__((packed));
+struct tracecmd_msg_trace_req {
+ be32 flags;
+ be32 argc;
+} __attribute__((packed));
+
+struct tracecmd_msg_trace_resp {
+ be32 cpus;
+ be32 page_size;
+} __attribute__((packed));
+
struct tracecmd_msg_header {
be32 size;
be32 cmd;
@@ -90,7 +101,9 @@ struct tracecmd_msg_header {
C(TINIT, 1, sizeof(struct tracecmd_msg_tinit)), \
C(RINIT, 2, sizeof(struct tracecmd_msg_rinit)), \
C(SEND_DATA, 3, 0), \
- C(FIN_DATA, 4, 0),
+ C(FIN_DATA, 4, 0), \
+ C(TRACE_REQ, 5, sizeof(struct tracecmd_msg_trace_req)), \
+ C(TRACE_RESP, 6, sizeof(struct tracecmd_msg_trace_resp)),
#undef C
#define C(a,b,c) MSG_##a = b
@@ -122,6 +135,8 @@ struct tracecmd_msg {
union {
struct tracecmd_msg_tinit tinit;
struct tracecmd_msg_rinit rinit;
+ struct tracecmd_msg_trace_req trace_req;
+ struct tracecmd_msg_trace_resp trace_resp;
};
union {
struct tracecmd_msg_opt *opt;
@@ -715,3 +730,192 @@ error:
msg_free(&msg);
return ret;
}
+
+static int make_trace_req(struct tracecmd_msg *msg, int argc, char **argv)
+{
+ size_t args_size = 0;
+ char *p;
+ int i;
+
+ for (i = 0; i < argc; i++)
+ args_size += strlen(argv[i]) + 1;
+
+ msg->hdr.size = htonl(ntohl(msg->hdr.size) + args_size);
+ msg->trace_req.argc = htonl(argc);
+ msg->buf = calloc(args_size, 1);
+ if (!msg->buf)
+ return -ENOMEM;
+
+ p = msg->buf;
+ for (i = 0; i < argc; i++)
+ p = stpcpy(p, argv[i]) + 1;
+
+ return 0;
+}
+
+int tracecmd_msg_send_trace_req(struct tracecmd_msg_handle *msg_handle,
+ int argc, char **argv)
+{
+ struct tracecmd_msg msg;
+ int ret;
+
+ tracecmd_msg_init(MSG_TRACE_REQ, &msg);
+ ret = make_trace_req(&msg, argc, argv);
+ if (ret)
+ return ret;
+
+ return tracecmd_msg_send(msg_handle->fd, &msg);
+}
+
+ /*
+ * NOTE: On success, the returned `argv` should be freed with:
+ * free(argv[0]);
+ * free(argv);
+ */
+int tracecmd_msg_recv_trace_req(struct tracecmd_msg_handle *msg_handle,
+ int *argc, char ***argv)
+{
+ struct tracecmd_msg msg;
+ char *p, *buf_end, **args;
+ int i, ret, nr_args;
+ size_t buf_len;
+
+ ret = tracecmd_msg_recv(msg_handle->fd, &msg);
+ if (ret < 0)
+ return ret;
+
+ if (ntohl(msg.hdr.cmd) != MSG_TRACE_REQ)
+ goto out;
+
+ if (ntohl(msg.trace_req.argc) < 0)
+ goto out;
+
+ buf_len = ntohl(msg.hdr.size) - MSG_HDR_LEN - ntohl(msg.hdr.cmd_size);
+ buf_end = (char *)msg.buf + buf_len;
+ p = msg.buf;
+ nr_args = ntohl(msg.trace_req.argc);
+ args = calloc(nr_args, sizeof(*args));
+ if (!args) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ for (i = 0; i < nr_args; i++) {
+ if (p >= buf_end) {
+ ret = -1;
+ free(args);
+ goto out;
+ }
+
+ args[i] = p;
+ p = strchr(p, '\0');
+ p++;
+ }
+
+ /*
+ * On success we're passing msg.buf to the caller through argv[0] so we
+ * reset it here to avoid getting it freed below.
+ */
+ msg.buf = NULL;
+ *argc = nr_args;
+ *argv = args;
+ ret = 0;
+
+out:
+ msg_free(&msg);
+ return ret;
+}
+
+static int make_trace_resp(struct tracecmd_msg *msg,
+ int page_size, int nr_cpus, unsigned int *ports)
+{
+ int ports_size = nr_cpus * sizeof(*msg->port_array);
+ int i;
+
+ msg->hdr.size = htonl(ntohl(msg->hdr.size) + ports_size);
+ msg->trace_resp.cpus = htonl(nr_cpus);
+ msg->trace_resp.page_size = htonl(page_size);
+
+ msg->port_array = malloc(ports_size);
+ if (!msg->port_array)
+ return -ENOMEM;
+
+ for (i = 0; i < nr_cpus; i++)
+ msg->port_array[i] = htonl(ports[i]);
+
+ return 0;
+}
+
+int tracecmd_msg_send_trace_resp(struct tracecmd_msg_handle *msg_handle,
+ int nr_cpus, int page_size,
+ unsigned int *ports)
+{
+ struct tracecmd_msg msg;
+ int ret;
+
+ tracecmd_msg_init(MSG_TRACE_RESP, &msg);
+ ret = make_trace_resp(&msg, page_size, nr_cpus, ports);
+ if (ret < 0)
+ return ret;
+
+ return tracecmd_msg_send(msg_handle->fd, &msg);
+}
+
+int tracecmd_msg_recv_trace_resp(struct tracecmd_msg_handle *msg_handle,
+ int *nr_cpus, int *page_size,
+ unsigned int **ports)
+{
+ struct tracecmd_msg msg;
+ size_t buf_len;
+ int i, ret;
+
+ ret = tracecmd_msg_recv(msg_handle->fd, &msg);
+ if (ret < 0)
+ return ret;
+
+ if (ntohl(msg.hdr.cmd) != MSG_TRACE_RESP) {
+ ret = -1;
+ goto out;
+ }
+
+ buf_len = ntohl(msg.hdr.size) - MSG_HDR_LEN - ntohl(msg.hdr.cmd_size);
+ if (buf_len <= 0 ||
+ buf_len != sizeof(*msg.port_array) * ntohl(msg.trace_resp.cpus)) {
+ ret = -1;
+ goto out;
+ }
+
+ *nr_cpus = ntohl(msg.trace_resp.cpus);
+ *page_size = ntohl(msg.trace_resp.page_size);
+ *ports = calloc(*nr_cpus, sizeof(**ports));
+ if (!*ports) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ for (i = 0; i < *nr_cpus; i++)
+ (*ports)[i] = ntohl(msg.port_array[i]);
+
+ ret = 0;
+
+out:
+ msg_free(&msg);
+ return ret;
+}
+
+int tracecmd_msg_wait_close(struct tracecmd_msg_handle *msg_handle)
+{
+ struct tracecmd_msg msg;
+ int ret;
+
+ memset(&msg, 0, sizeof(msg));
+ for (;;) {
+ ret = tracecmd_msg_wait_for_msg(msg_handle->fd, &msg);
+ msg_free(&msg);
+
+ if (ret == -ECONNABORTED)
+ return 0;
+ if (ret < 0)
+ return ret;
+ }
+
+ return -1;
+}
--
2.19.1
next prev parent reply other threads:[~2019-01-16 13:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-16 13:42 [PATCH v4 0/8] Add VM kernel tracing over vsock sockets Slavomir Kaslev
2019-01-16 13:43 ` [PATCH v4 1/8] trace-cmd: Minor refactoring Slavomir Kaslev
2019-01-16 13:43 ` [PATCH v4 2/8] trace-cmd: Detect if vsock sockets are available Slavomir Kaslev
2019-01-16 13:43 ` [PATCH v4 3/8] trace-cmd: Add tracecmd_create_recorder_virt function Slavomir Kaslev
2019-01-16 13:43 ` [PATCH v4 4/8] trace-cmd: Use unsigned int for trace-cmd client ports Slavomir Kaslev
2019-01-16 13:43 ` Slavomir Kaslev [this message]
2019-01-16 14:19 ` [PATCH v4 5/8] trace-cmd: Add TRACE_REQ and TRACE_RESP messages Steven Rostedt
2019-01-16 13:43 ` [PATCH v4 6/8] trace-cmd: Add buffer instance flags for tracing in guest and agent context Slavomir Kaslev
2019-01-16 13:43 ` [PATCH v4 7/8] trace-cmd: Add VM kernel tracing over vsock sockets transport Slavomir Kaslev
2019-01-16 13:43 ` [PATCH v4 8/8] trace-cmd: Use splice(2) for vsock sockets if available Slavomir Kaslev
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