From: Slavomir Kaslev <kaslevs@vmware.com>
To: rostedt@goodmis.org
Cc: linux-trace-devel@vger.kernel.org
Subject: [PATCH v14 09/13] trace-cmd: Add `trace-cmd setup-guest` command
Date: Tue, 17 Sep 2019 16:15:34 +0300 [thread overview]
Message-ID: <20190917131538.31926-10-kaslevs@vmware.com> (raw)
In-Reply-To: <20190917131538.31926-1-kaslevs@vmware.com>
Add `trace-cmd setup-guest` command that creates the necessary FIFOs for tracing
a guest over FIFOs instead of vsockets.
Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
tracecmd/Makefile | 1 +
tracecmd/include/trace-local.h | 6 ++
tracecmd/trace-cmd.c | 1 +
tracecmd/trace-setup-guest.c | 178 +++++++++++++++++++++++++++++++++
tracecmd/trace-usage.c | 8 ++
5 files changed, 194 insertions(+)
create mode 100644 tracecmd/trace-setup-guest.c
diff --git a/tracecmd/Makefile b/tracecmd/Makefile
index fb85e47..29a623b 100644
--- a/tracecmd/Makefile
+++ b/tracecmd/Makefile
@@ -33,6 +33,7 @@ TRACE_CMD_OBJS += trace-usage.o
ifeq ($(VSOCK_DEFINED), 1)
TRACE_CMD_OBJS += trace-agent.o
+TRACE_CMD_OBJS += trace-setup-guest.o
endif
ALL_OBJS := $(TRACE_CMD_OBJS:%.o=$(bdir)/%.o)
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index 00a8e38..4df8686 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -14,6 +14,10 @@
#define TRACE_AGENT_DEFAULT_PORT 823
+#define GUEST_PIPE_NAME "trace-pipe-cpu"
+#define GUEST_DIR_FMT "/var/lib/trace-cmd/virt/%s"
+#define GUEST_FIFO_FMT GUEST_DIR_FMT "/" GUEST_PIPE_NAME "%d"
+
extern int quiet;
/* fix stupid glib guint64 typecasts and printf formats */
@@ -67,6 +71,8 @@ void trace_listen(int argc, char **argv);
void trace_agent(int argc, char **argv);
+void trace_setup_guest(int argc, char **argv);
+
void trace_restore(int argc, char **argv);
void trace_clear(int argc, char **argv);
diff --git a/tracecmd/trace-cmd.c b/tracecmd/trace-cmd.c
index cdaaadf..afc84a8 100644
--- a/tracecmd/trace-cmd.c
+++ b/tracecmd/trace-cmd.c
@@ -84,6 +84,7 @@ struct command commands[] = {
{"listen", trace_listen},
#ifdef VSOCK
{"agent", trace_agent},
+ {"setup-guest", trace_setup_guest},
#endif
{"split", trace_split},
{"restore", trace_restore},
diff --git a/tracecmd/trace-setup-guest.c b/tracecmd/trace-setup-guest.c
new file mode 100644
index 0000000..a6f58dc
--- /dev/null
+++ b/tracecmd/trace-setup-guest.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 VMware Inc, Slavomir Kaslev <kaslevs@vmware.com>
+ *
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <grp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "trace-local.h"
+#include "trace-msg.h"
+
+static int make_dir(const char *path, mode_t mode)
+{
+ char buf[PATH_MAX+2], *p;
+
+ strncpy(buf, path, sizeof(buf));
+ if (buf[PATH_MAX])
+ return -E2BIG;
+
+ for (p = buf; *p; p++) {
+ p += strspn(p, "/");
+ p += strcspn(p, "/");
+ *p = '\0';
+ if (mkdir(buf, mode) < 0 && errno != EEXIST)
+ return -errno;
+ *p = '/';
+ }
+
+ return 0;
+}
+
+static int make_fifo(const char *path, mode_t mode)
+{
+ struct stat st;
+
+ if (!stat(path, &st)) {
+ if (S_ISFIFO(st.st_mode))
+ return 0;
+ return -EEXIST;
+ }
+
+ if (mkfifo(path, mode))
+ return -errno;
+ return 0;
+}
+
+static int make_guest_dir(const char *guest)
+{
+ char path[PATH_MAX];
+
+ snprintf(path, sizeof(path), GUEST_DIR_FMT, guest);
+ return make_dir(path, 0750);
+}
+
+static int make_guest_fifo(const char *guest, int cpu, mode_t mode)
+{
+ static const char *exts[] = {".in", ".out"};
+ char path[PATH_MAX];
+ int i, ret = 0;
+
+ for (i = 0; i < ARRAY_SIZE(exts); i++) {
+ snprintf(path, sizeof(path), GUEST_FIFO_FMT "%s",
+ guest, cpu, exts[i]);
+ ret = make_fifo(path, mode);
+ if (ret < 0)
+ break;
+ }
+
+ return ret;
+}
+
+static int make_guest_fifos(const char *guest, int nr_cpus, mode_t mode)
+{
+ int i, ret = 0;
+ mode_t mask;
+
+ mask = umask(0);
+ for (i = 0; i < nr_cpus; i++) {
+ ret = make_guest_fifo(guest, i, mode);
+ if (ret < 0)
+ break;
+ }
+ umask(mask);
+
+ return ret;
+}
+
+static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gid)
+{
+ gid_t save_egid;
+ int ret;
+
+ if (gid != -1) {
+ save_egid = getegid();
+ ret = setegid(gid);
+ if (ret < 0)
+ pdie("failed to set effective group ID");
+ }
+
+ ret = make_guest_dir(guest);
+ if (ret < 0)
+ pdie("failed to create guest directory for %s", guest);
+
+ ret = make_guest_fifos(guest, nr_cpus, mode);
+ if (ret < 0)
+ pdie("failed to create FIFOs for %s", guest);
+
+ if (gid != -1) {
+ ret = setegid(save_egid);
+ if (ret < 0)
+ pdie("failed to restore effective group ID");
+ }
+}
+
+void trace_setup_guest(int argc, char **argv)
+{
+ struct group *group;
+ mode_t mode = 0660;
+ int nr_cpus = -1;
+ gid_t gid = -1;
+ char *guest;
+
+ if (argc < 2)
+ usage(argv);
+
+ if (strcmp(argv[1], "setup-guest") != 0)
+ usage(argv);
+
+ for (;;) {
+ int c, option_index = 0;
+ static struct option long_options[] = {
+ {"help", no_argument, NULL, '?'},
+ {NULL, 0, NULL, 0}
+ };
+
+ c = getopt_long(argc-1, argv+1, "+hc:p:g:",
+ long_options, &option_index);
+ if (c == -1)
+ break;
+ switch (c) {
+ case 'h':
+ usage(argv);
+ break;
+ case 'c':
+ nr_cpus = atoi(optarg);
+ break;
+ case 'p':
+ mode = strtol(optarg, NULL, 8);
+ break;
+ case 'g':
+ group = getgrnam(optarg);
+ if (!group)
+ pdie("group %s does not exist", optarg);
+ gid = group->gr_gid;
+ break;
+ default:
+ usage(argv);
+ }
+ }
+
+ if (optind != argc-2)
+ usage(argv);
+
+ guest = argv[optind+1];
+
+ if (nr_cpus <= 0)
+ pdie("invalid number of cpus for guest %s", guest);
+
+ do_setup_guest(guest, nr_cpus, mode, gid);
+}
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index da17df7..2caff0e 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -248,6 +248,14 @@ static struct usage_help usage_help[] = {
" -p port number to listen on.\n"
" -D run in daemon mode.\n"
},
+ {
+ "setup-guest",
+ "create FIFOs for tracing guest VMs",
+ " %s setup-guest -c cpus[-p perm][-g group] guest\n"
+ " -c number of guest virtual CPUs\n"
+ " -p FIFOs permissions (default: 0660)\n"
+ " -g FIFOs group owner\n"
+ },
#endif
{
"list",
--
2.20.1
next prev parent reply other threads:[~2019-09-17 13:15 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-17 13:15 [PATCH v14 00/13] Add VM kernel tracing over vsockets and FIFOs Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 01/13] trace-cmd: Make ports unsigned int Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 02/13] trace-cmd: Detect if vsockets are available Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 03/13] trace-cmd: Add tracecmd_create_recorder_virt() function Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 04/13] trace-cmd: Add VM tracing protocol messages Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 05/13] trace-cmd: Add buffer instance flags for tracing in guest and agent context Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 06/13] trace-cmd: Add VM kernel tracing over vsockets transport Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 07/13] trace-cmd: Use splice(2) for vsockets if available Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 08/13] trace-cmd: Switch stop recording signal to SIGUSR1 Slavomir Kaslev
2019-09-17 13:15 ` Slavomir Kaslev [this message]
2019-09-17 13:15 ` [PATCH v14 10/13] trace-cmd: Try to autodetect number of guest CPUs in setup-guest if not specified Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 11/13] trace-cmd: Add setup-guest flag for attaching FIFOs to the guest VM config Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 12/13] trace-cmd: Add VM kernel tracing over FIFO transport Slavomir Kaslev
2019-09-17 13:15 ` [PATCH v14 13/13] trace-cmd: Add support for tracing VMware Workstation VMs by name Slavomir Kaslev
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190917131538.31926-10-kaslevs@vmware.com \
--to=kaslevs@vmware.com \
--cc=linux-trace-devel@vger.kernel.org \
--cc=rostedt@goodmis.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.