contrib/ivshmem-server/main.c

   1 /*
   2  * Copyright 6WIND S.A., 2014
   3  *
   4  * This work is licensed under the terms of the GNU GPL, version 2 or
   5  * (at your option) any later version.  See the COPYING file in the
   6  * top-level directory.
   7  */
   8
   9 #include "qemu/osdep.h"
  10 #include "qemu-common.h"
  11
  12 #include "ivshmem-server.h"
  13
  14 #define IVSHMEM_SERVER_DEFAULT_VERBOSE        0
  15 #define IVSHMEM_SERVER_DEFAULT_FOREGROUND     0
  16 #define IVSHMEM_SERVER_DEFAULT_PID_FILE       "/var/run/ivshmem-server.pid"
  17 #define IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "/tmp/ivshmem_socket"
  18 #define IVSHMEM_SERVER_DEFAULT_SHM_PATH       "ivshmem"
  19 #define IVSHMEM_SERVER_DEFAULT_SHM_SIZE       (4*1024*1024)
  20 #define IVSHMEM_SERVER_DEFAULT_N_VECTORS      1
  21
  22 /* used to quit on signal SIGTERM */
  23 static int ivshmem_server_quit;
  24
  25 /* arguments given by the user */
  26 typedef struct IvshmemServerArgs {
  27     bool verbose;
  28     bool foreground;
  29     const char *pid_file;
  30     const char *unix_socket_path;
  31     const char *shm_path;
  32     bool use_shm_open;
  33     uint64_t shm_size;
  34     unsigned n_vectors;
  35 } IvshmemServerArgs;
  36
  37 static void
  38 ivshmem_server_usage(const char *progname)
  39 {
  40     printf("Usage: %s [OPTION]...\n"
  41            "  -h: show this help\n"
  42            "  -v: verbose mode\n"
  43            "  -F: foreground mode (default is to daemonize)\n"
  44            "  -p <pid-file>: path to the PID file (used in daemon mode only)\n"
  45            "     default " IVSHMEM_SERVER_DEFAULT_PID_FILE "\n"
  46            "  -S <unix-socket-path>: path to the unix socket to listen to\n"
  47            "     default " IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "\n"
  48            "  -M <shm-name>: POSIX shared memory object to use\n"
  49            "     default " IVSHMEM_SERVER_DEFAULT_SHM_PATH "\n"
  50            "  -m <dir-name>: where to create shared memory\n"
  51            "  -l <size>: size of shared memory in bytes\n"
  52            "     suffixes K, M and G can be used, e.g. 1K means 1024\n"
  53            "     default %u\n"
  54            "  -n <nvectors>: number of vectors\n"
  55            "     default %u\n",
  56            progname, IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
  57            IVSHMEM_SERVER_DEFAULT_N_VECTORS);
  58 }
  59
  60 static void
  61 ivshmem_server_help(const char *progname)
  62 {
  63     fprintf(stderr, "Try '%s -h' for more information.\n", progname);
  64 }
  65
  66 /* parse the program arguments, exit on error */
  67 static void
  68 ivshmem_server_parse_args(IvshmemServerArgs *args, int argc, char *argv[])
  69 {
  70     int c;
  71     unsigned long long v;
  72     Error *err = NULL;
  73
  74     while ((c = getopt(argc, argv, "hvFp:S:m:M:l:n:")) != -1) {
  75
  76         switch (c) {
  77         case 'h': /* help */
  78             ivshmem_server_usage(argv[0]);
  79             exit(0);
  80             break;
  81
  82         case 'v': /* verbose */
  83             args->verbose = 1;
  84             break;
  85
  86         case 'F': /* foreground */
  87             args->foreground = 1;
  88             break;
  89
  90         case 'p': /* pid file */
  91             args->pid_file = optarg;
  92             break;
  93
  94         case 'S': /* unix socket path */
  95             args->unix_socket_path = optarg;
  96             break;
  97
  98         case 'M': /* shm name */
  99         case 'm': /* dir name */
 100             args->shm_path = optarg;
 101             args->use_shm_open = c == 'M';
 102             break;
 103
 104         case 'l': /* shm size */
 105             parse_option_size("shm_size", optarg, &args->shm_size, &err);
 106             if (err) {
 107                 error_report_err(err);
 108                 ivshmem_server_help(argv[0]);
 109                 exit(1);
 110             }
 111             break;
 112
 113         case 'n': /* number of vectors */
 114             if (parse_uint_full(optarg, &v, 0) < 0) {
 115                 fprintf(stderr, "cannot parse n_vectors\n");
 116                 ivshmem_server_help(argv[0]);
 117                 exit(1);
 118             }
 119             args->n_vectors = v;
 120             break;
 121
 122         default:
 123             ivshmem_server_usage(argv[0]);
 124             exit(1);
 125             break;
 126         }
 127     }
 128
 129     if (args->n_vectors > IVSHMEM_SERVER_MAX_VECTORS) {
 130         fprintf(stderr, "too many requested vectors (max is %d)\n",
 131                 IVSHMEM_SERVER_MAX_VECTORS);
 132         ivshmem_server_help(argv[0]);
 133         exit(1);
 134     }
 135
 136     if (args->verbose == 1 && args->foreground == 0) {
 137         fprintf(stderr, "cannot use verbose in daemon mode\n");
 138         ivshmem_server_help(argv[0]);
 139         exit(1);
 140     }
 141 }
 142
 143 /* wait for events on listening server unix socket and connected client
 144  * sockets */
 145 static int
 146 ivshmem_server_poll_events(IvshmemServer *server)
 147 {
 148     fd_set fds;
 149     int ret = 0, maxfd;
 150
 151     while (!ivshmem_server_quit) {
 152
 153         FD_ZERO(&fds);
 154         maxfd = 0;
 155         ivshmem_server_get_fds(server, &fds, &maxfd);
 156
 157         ret = select(maxfd, &fds, NULL, NULL, NULL);
 158
 159         if (ret < 0) {
 160             if (errno == EINTR) {
 161                 continue;
 162             }
 163
 164             fprintf(stderr, "select error: %s\n", strerror(errno));
 165             break;
 166         }
 167         if (ret == 0) {
 168             continue;
 169         }
 170
 171         if (ivshmem_server_handle_fds(server, &fds, maxfd) < 0) {
 172             fprintf(stderr, "ivshmem_server_handle_fds() failed\n");
 173             break;
 174         }
 175     }
 176
 177     return ret;
 178 }
 179
 180 static void
 181 ivshmem_server_quit_cb(int signum)
 182 {
 183     ivshmem_server_quit = 1;
 184 }
 185
 186 int
 187 main(int argc, char *argv[])
 188 {
 189     IvshmemServer server;
 190     struct sigaction sa, sa_quit;
 191     IvshmemServerArgs args = {
 192         .verbose = IVSHMEM_SERVER_DEFAULT_VERBOSE,
 193         .foreground = IVSHMEM_SERVER_DEFAULT_FOREGROUND,
 194         .pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE,
 195         .unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH,
 196         .shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH,
 197         .use_shm_open = true,
 198         .shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
 199         .n_vectors = IVSHMEM_SERVER_DEFAULT_N_VECTORS,
 200     };
 201     int ret = 1;
 202
 203     /*
 204      * Do not remove this notice without adding proper error handling!
 205      * Start with handling ivshmem_server_send_one_msg() failure.
 206      */
 207     printf("*** Example code, do not use in production ***\n");
 208
 209     /* parse arguments, will exit on error */
 210     ivshmem_server_parse_args(&args, argc, argv);
 211
 212     /* Ignore SIGPIPE, see this link for more info:
 213      * http://www.mail-archive.com/libevent-users@monkey.org/msg01606.html */
 214     sa.sa_handler = SIG_IGN;
 215     sa.sa_flags = 0;
 216     if (sigemptyset(&sa.sa_mask) == -1 ||
 217         sigaction(SIGPIPE, &sa, 0) == -1) {
 218         perror("failed to ignore SIGPIPE; sigaction");
 219         goto err;
 220     }
 221
 222     sa_quit.sa_handler = ivshmem_server_quit_cb;
 223     sa_quit.sa_flags = 0;
 224     if (sigemptyset(&sa_quit.sa_mask) == -1 ||
 225         sigaction(SIGTERM, &sa_quit, 0) == -1) {
 226         perror("failed to add SIGTERM handler; sigaction");
 227         goto err;
 228     }
 229
 230     /* init the ivshms structure */
 231     if (ivshmem_server_init(&server, args.unix_socket_path,
 232                             args.shm_path, args.use_shm_open,
 233                             args.shm_size, args.n_vectors, args.verbose) < 0) {
 234         fprintf(stderr, "cannot init server\n");
 235         goto err;
 236     }
 237
 238     /* start the ivshmem server (open shm & unix socket) */
 239     if (ivshmem_server_start(&server) < 0) {
 240         fprintf(stderr, "cannot bind\n");
 241         goto err;
 242     }
 243
 244     /* daemonize if asked to */
 245     if (!args.foreground) {
 246         FILE *fp;
 247
 248         if (qemu_daemon(1, 1) < 0) {
 249             fprintf(stderr, "cannot daemonize: %s\n", strerror(errno));
 250             goto err_close;
 251         }
 252
 253         /* write pid file */
 254         fp = fopen(args.pid_file, "w");
 255         if (fp == NULL) {
 256             fprintf(stderr, "cannot write pid file: %s\n", strerror(errno));
 257             goto err_close;
 258         }
 259
 260         fprintf(fp, "%d\n", (int) getpid());
 261         fclose(fp);
 262     }
 263
 264     ivshmem_server_poll_events(&server);
 265     fprintf(stdout, "server disconnected\n");
 266     ret = 0;
 267
 268 err_close:
 269     ivshmem_server_close(&server);
 270 err:
 271     return ret;
 272 }