Commit ed36b704 authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo
Browse files

perf daemon: Add server socket support 



Add support to create a server socket that listens for client commands
and processes them.

This patch adds only the core support, all commands using this
functionality are coming in the following patches.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-5-jolsa@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 5631d100

tools/perf/builtin-daemon.c

+116 −1
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <internal/lib.h>

#include <subcmd/parse-options.h>

#include <api/fd/array.h>

#include <linux/limits.h>

#include <linux/string.h>

#include <string.h>

#include <signal.h>

#include <stdlib.h>

#include <stdio.h>

#include <unistd.h>

#include <errno.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/un.h>

#include <poll.h>

#include "builtin.h"

#include "perf.h"

#include "debug.h"
@@ -37,6 +44,92 @@ static void sig_handler(int sig __maybe_unused) 
	done = true;

}



static int setup_server_socket(struct daemon *daemon)

{

	struct sockaddr_un addr;

	char path[PATH_MAX];

	int fd = socket(AF_UNIX, SOCK_STREAM, 0);



	if (fd < 0) {

		fprintf(stderr, "socket: %s\n", strerror(errno));

		return -1;

	}



	if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {

		perror("failed: fcntl FD_CLOEXEC");

		close(fd);

		return -1;

	}



	scnprintf(path, sizeof(path), "%s/control", daemon->base);



	if (strlen(path) + 1 >= sizeof(addr.sun_path)) {

		pr_err("failed: control path too long '%s'\n", path);

		close(fd);

		return -1;

	}



	memset(&addr, 0, sizeof(addr));

	addr.sun_family = AF_UNIX;



	strlcpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);

	unlink(path);



	if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {

		perror("failed: bind");

		close(fd);

		return -1;

	}



	if (listen(fd, 1) == -1) {

		perror("failed: listen");

		close(fd);

		return -1;

	}



	return fd;

}



union cmd {

	int cmd;

};



static int handle_server_socket(struct daemon *daemon __maybe_unused, int sock_fd)

{

	int ret = -1, fd;

	FILE *out = NULL;

	union cmd cmd;



	fd = accept(sock_fd, NULL, NULL);

	if (fd < 0) {

		perror("failed: accept");

		return -1;

	}



	if (sizeof(cmd) != readn(fd, &cmd, sizeof(cmd))) {

		perror("failed: read");

		goto out;

	}



	out = fdopen(fd, "w");

	if (!out) {

		perror("failed: fdopen");

		goto out;

	}



	switch (cmd.cmd) {

	default:

		break;

	}



	fclose(out);

out:

	/* If out is defined, then fd is closed via fclose. */

	if (!out)

		close(fd);

	return ret;

}



static void daemon__exit(struct daemon *daemon)

{

	free(daemon->config_real);
@@ -77,6 +170,9 @@ static int __cmd_start(struct daemon *daemon, struct option parent_options[], 
		OPT_PARENT(parent_options),

		OPT_END()

	};

	int sock_fd = -1;

	int sock_pos;

	struct fdarray fda;

	int err = 0;



	argc = parse_options(argc, argv, start_options, daemon_usage, 0);
@@ -93,15 +189,34 @@ static int __cmd_start(struct daemon *daemon, struct option parent_options[], 


	pr_info("daemon started (pid %d)\n", getpid());



	fdarray__init(&fda, 1);



	sock_fd = setup_server_socket(daemon);

	if (sock_fd < 0)

		goto out;



	sock_pos = fdarray__add(&fda, sock_fd, POLLIN|POLLERR|POLLHUP, 0);

	if (sock_pos < 0)

		goto out;



	signal(SIGINT, sig_handler);

	signal(SIGTERM, sig_handler);



	while (!done && !err) {

		sleep(1);

		if (fdarray__poll(&fda, -1)) {

			if (fda.entries[sock_pos].revents & POLLIN)

				err = handle_server_socket(daemon, sock_fd);

		}

	}



out:

	fdarray__exit(&fda);



	daemon__exit(daemon);



	if (sock_fd != -1)

		close(sock_fd);



	pr_info("daemon exited\n");

	fclose(daemon->out);

	return err;