qemu/contrib/ivshmem-server/main.c

274 lines
7.7 KiB
C

/*
* Copyright 6WIND S.A., 2014
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* (at your option) any later version. See the COPYING file in the
* top-level directory.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/cutils.h"
#include "ivshmem-server.h"
#define IVSHMEM_SERVER_DEFAULT_VERBOSE 0
#define IVSHMEM_SERVER_DEFAULT_FOREGROUND 0
#define IVSHMEM_SERVER_DEFAULT_PID_FILE "/var/run/ivshmem-server.pid"
#define IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "/tmp/ivshmem_socket"
#define IVSHMEM_SERVER_DEFAULT_SHM_PATH "ivshmem"
#define IVSHMEM_SERVER_DEFAULT_SHM_SIZE (4*1024*1024)
#define IVSHMEM_SERVER_DEFAULT_N_VECTORS 1
/* used to quit on signal SIGTERM */
static int ivshmem_server_quit;
/* arguments given by the user */
typedef struct IvshmemServerArgs {
bool verbose;
bool foreground;
const char *pid_file;
const char *unix_socket_path;
const char *shm_path;
bool use_shm_open;
uint64_t shm_size;
unsigned n_vectors;
} IvshmemServerArgs;
static void
ivshmem_server_usage(const char *progname)
{
printf("Usage: %s [OPTION]...\n"
" -h: show this help\n"
" -v: verbose mode\n"
" -F: foreground mode (default is to daemonize)\n"
" -p <pid-file>: path to the PID file (used in daemon mode only)\n"
" default " IVSHMEM_SERVER_DEFAULT_PID_FILE "\n"
" -S <unix-socket-path>: path to the unix socket to listen to\n"
" default " IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "\n"
" -M <shm-name>: POSIX shared memory object to use\n"
" default " IVSHMEM_SERVER_DEFAULT_SHM_PATH "\n"
" -m <dir-name>: where to create shared memory\n"
" -l <size>: size of shared memory in bytes\n"
" suffixes K, M and G can be used, e.g. 1K means 1024\n"
" default %u\n"
" -n <nvectors>: number of vectors\n"
" default %u\n",
progname, IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
IVSHMEM_SERVER_DEFAULT_N_VECTORS);
}
static void
ivshmem_server_help(const char *progname)
{
fprintf(stderr, "Try '%s -h' for more information.\n", progname);
}
/* parse the program arguments, exit on error */
static void
ivshmem_server_parse_args(IvshmemServerArgs *args, int argc, char *argv[])
{
int c;
unsigned long long v;
Error *err = NULL;
while ((c = getopt(argc, argv, "hvFp:S:m:M:l:n:")) != -1) {
switch (c) {
case 'h': /* help */
ivshmem_server_usage(argv[0]);
exit(0);
break;
case 'v': /* verbose */
args->verbose = 1;
break;
case 'F': /* foreground */
args->foreground = 1;
break;
case 'p': /* pid file */
args->pid_file = optarg;
break;
case 'S': /* unix socket path */
args->unix_socket_path = optarg;
break;
case 'M': /* shm name */
case 'm': /* dir name */
args->shm_path = optarg;
args->use_shm_open = c == 'M';
break;
case 'l': /* shm size */
parse_option_size("shm_size", optarg, &args->shm_size, &err);
if (err) {
error_report_err(err);
ivshmem_server_help(argv[0]);
exit(1);
}
break;
case 'n': /* number of vectors */
if (parse_uint_full(optarg, &v, 0) < 0) {
fprintf(stderr, "cannot parse n_vectors\n");
ivshmem_server_help(argv[0]);
exit(1);
}
args->n_vectors = v;
break;
default:
ivshmem_server_usage(argv[0]);
exit(1);
break;
}
}
if (args->n_vectors > IVSHMEM_SERVER_MAX_VECTORS) {
fprintf(stderr, "too many requested vectors (max is %d)\n",
IVSHMEM_SERVER_MAX_VECTORS);
ivshmem_server_help(argv[0]);
exit(1);
}
if (args->verbose == 1 && args->foreground == 0) {
fprintf(stderr, "cannot use verbose in daemon mode\n");
ivshmem_server_help(argv[0]);
exit(1);
}
}
/* wait for events on listening server unix socket and connected client
* sockets */
static int
ivshmem_server_poll_events(IvshmemServer *server)
{
fd_set fds;
int ret = 0, maxfd;
while (!ivshmem_server_quit) {
FD_ZERO(&fds);
maxfd = 0;
ivshmem_server_get_fds(server, &fds, &maxfd);
ret = select(maxfd, &fds, NULL, NULL, NULL);
if (ret < 0) {
if (errno == EINTR) {
continue;
}
fprintf(stderr, "select error: %s\n", strerror(errno));
break;
}
if (ret == 0) {
continue;
}
if (ivshmem_server_handle_fds(server, &fds, maxfd) < 0) {
fprintf(stderr, "ivshmem_server_handle_fds() failed\n");
break;
}
}
return ret;
}
static void
ivshmem_server_quit_cb(int signum)
{
ivshmem_server_quit = 1;
}
int
main(int argc, char *argv[])
{
IvshmemServer server;
struct sigaction sa, sa_quit;
IvshmemServerArgs args = {
.verbose = IVSHMEM_SERVER_DEFAULT_VERBOSE,
.foreground = IVSHMEM_SERVER_DEFAULT_FOREGROUND,
.pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE,
.unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH,
.shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH,
.use_shm_open = true,
.shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
.n_vectors = IVSHMEM_SERVER_DEFAULT_N_VECTORS,
};
int ret = 1;
/*
* Do not remove this notice without adding proper error handling!
* Start with handling ivshmem_server_send_one_msg() failure.
*/
printf("*** Example code, do not use in production ***\n");
/* parse arguments, will exit on error */
ivshmem_server_parse_args(&args, argc, argv);
/* Ignore SIGPIPE, see this link for more info:
* http://www.mail-archive.com/libevent-users@monkey.org/msg01606.html */
sa.sa_handler = SIG_IGN;
sa.sa_flags = 0;
if (sigemptyset(&sa.sa_mask) == -1 ||
sigaction(SIGPIPE, &sa, 0) == -1) {
perror("failed to ignore SIGPIPE; sigaction");
goto err;
}
sa_quit.sa_handler = ivshmem_server_quit_cb;
sa_quit.sa_flags = 0;
if (sigemptyset(&sa_quit.sa_mask) == -1 ||
sigaction(SIGTERM, &sa_quit, 0) == -1) {
perror("failed to add SIGTERM handler; sigaction");
goto err;
}
/* init the ivshms structure */
if (ivshmem_server_init(&server, args.unix_socket_path,
args.shm_path, args.use_shm_open,
args.shm_size, args.n_vectors, args.verbose) < 0) {
fprintf(stderr, "cannot init server\n");
goto err;
}
/* start the ivshmem server (open shm & unix socket) */
if (ivshmem_server_start(&server) < 0) {
fprintf(stderr, "cannot bind\n");
goto err;
}
/* daemonize if asked to */
if (!args.foreground) {
FILE *fp;
if (qemu_daemon(1, 1) < 0) {
fprintf(stderr, "cannot daemonize: %s\n", strerror(errno));
goto err_close;
}
/* write pid file */
fp = fopen(args.pid_file, "w");
if (fp == NULL) {
fprintf(stderr, "cannot write pid file: %s\n", strerror(errno));
goto err_close;
}
fprintf(fp, "%d\n", (int) getpid());
fclose(fp);
}
ivshmem_server_poll_events(&server);
fprintf(stdout, "server disconnected\n");
ret = 0;
err_close:
ivshmem_server_close(&server);
err:
return ret;
}