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     uint64_t shm_size;
  33     unsigned n_vectors;
  34 } IvshmemServerArgs;
  35
  36 /* show ivshmem_server_usage and exit with given error code */
  37 static void
  38 ivshmem_server_usage(const char *name, int code)
  39 {
  40     fprintf(stderr, "%s [opts]\n", name);
  41     fprintf(stderr, "  -h: show this help\n");
  42     fprintf(stderr, "  -v: verbose mode\n");
  43     fprintf(stderr, "  -F: foreground mode (default is to daemonize)\n");
  44     fprintf(stderr, "  -p <pid_file>: path to the PID file (used in daemon\n"
  45                     "     mode only).\n"
  46                     "     Default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH);
  47     fprintf(stderr, "  -S <unix_socket_path>: path to the unix socket\n"
  48                     "     to listen to.\n"
  49                     "     Default=%s\n", IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH);
  50     fprintf(stderr, "  -m <shm_path>: path to the shared memory.\n"
  51                     "     The path corresponds to a POSIX shm name or a\n"
  52                     "     hugetlbfs mount point.\n"
  53                     "     default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH);
  54     fprintf(stderr, "  -l <size>: size of shared memory in bytes. The suffix\n"
  55                     "     K, M and G can be used (ex: 1K means 1024).\n"
  56                     "     default=%u\n", IVSHMEM_SERVER_DEFAULT_SHM_SIZE);
  57     fprintf(stderr, "  -n <n_vects>: number of vectors.\n"
  58                     "     default=%u\n", IVSHMEM_SERVER_DEFAULT_N_VECTORS);
  59
  60     exit(code);
  61 }
  62
  63 /* parse the program arguments, exit on error */
  64 static void
  65 ivshmem_server_parse_args(IvshmemServerArgs *args, int argc, char *argv[])
  66 {
  67     int c;
  68     unsigned long long v;
  69     Error *err = NULL;
  70
  71     while ((c = getopt(argc, argv,
  72                        "h"  /* help */
  73                        "v"  /* verbose */
  74                        "F"  /* foreground */
  75                        "p:" /* pid_file */
  76                        "S:" /* unix_socket_path */
  77                        "m:" /* shm_path */
  78                        "l:" /* shm_size */
  79                        "n:" /* n_vectors */
  80                       )) != -1) {
  81
  82         switch (c) {
  83         case 'h': /* help */
  84             ivshmem_server_usage(argv[0], 0);
  85             break;
  86
  87         case 'v': /* verbose */
  88             args->verbose = 1;
  89             break;
  90
  91         case 'F': /* foreground */
  92             args->foreground = 1;
  93             break;
  94
  95         case 'p': /* pid_file */
  96             args->pid_file = optarg;
  97             break;
  98
  99         case 'S': /* unix_socket_path */
 100             args->unix_socket_path = optarg;
 101             break;
 102
 103         case 'm': /* shm_path */
 104             args->shm_path = optarg;
 105             break;
 106
 107         case 'l': /* shm_size */
 108             parse_option_size("shm_size", optarg, &args->shm_size, &err);
 109             if (err) {
 110                 error_report_err(err);
 111                 ivshmem_server_usage(argv[0], 1);
 112             }
 113             break;
 114
 115         case 'n': /* n_vectors */
 116             if (parse_uint_full(optarg, &v, 0) < 0) {
 117                 fprintf(stderr, "cannot parse n_vectors\n");
 118                 ivshmem_server_usage(argv[0], 1);
 119             }
 120             args->n_vectors = v;
 121             break;
 122
 123         default:
 124             ivshmem_server_usage(argv[0], 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_usage(argv[0], 1);
 133     }
 134
 135     if (args->verbose == 1 && args->foreground == 0) {
 136         fprintf(stderr, "cannot use verbose in daemon mode\n");
 137         ivshmem_server_usage(argv[0], 1);
 138     }
 139 }
 140
 141 /* wait for events on listening server unix socket and connected client
 142  * sockets */
 143 static int
 144 ivshmem_server_poll_events(IvshmemServer *server)
 145 {
 146     fd_set fds;
 147     int ret = 0, maxfd;
 148
 149     while (!ivshmem_server_quit) {
 150
 151         FD_ZERO(&fds);
 152         maxfd = 0;
 153         ivshmem_server_get_fds(server, &fds, &maxfd);
 154
 155         ret = select(maxfd, &fds, NULL, NULL, NULL);
 156
 157         if (ret < 0) {
 158             if (errno == EINTR) {
 159                 continue;
 160             }
 161
 162             fprintf(stderr, "select error: %s\n", strerror(errno));
 163             break;
 164         }
 165         if (ret == 0) {
 166             continue;
 167         }
 168
 169         if (ivshmem_server_handle_fds(server, &fds, maxfd) < 0) {
 170             fprintf(stderr, "ivshmem_server_handle_fds() failed\n");
 171             break;
 172         }
 173     }
 174
 175     return ret;
 176 }
 177
 178 static void
 179 ivshmem_server_quit_cb(int signum)
 180 {
 181     ivshmem_server_quit = 1;
 182 }
 183
 184 int
 185 main(int argc, char *argv[])
 186 {
 187     IvshmemServer server;
 188     struct sigaction sa, sa_quit;
 189     IvshmemServerArgs args = {
 190         .verbose = IVSHMEM_SERVER_DEFAULT_VERBOSE,
 191         .foreground = IVSHMEM_SERVER_DEFAULT_FOREGROUND,
 192         .pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE,
 193         .unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH,
 194         .shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH,
 195         .shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
 196         .n_vectors = IVSHMEM_SERVER_DEFAULT_N_VECTORS,
 197     };
 198     int ret = 1;
 199
 200     /* parse arguments, will exit on error */
 201     ivshmem_server_parse_args(&args, argc, argv);
 202
 203     /* Ignore SIGPIPE, see this link for more info:
 204      * http://www.mail-archive.com/libevent-users@monkey.org/msg01606.html */
 205     sa.sa_handler = SIG_IGN;
 206     sa.sa_flags = 0;
 207     if (sigemptyset(&sa.sa_mask) == -1 ||
 208         sigaction(SIGPIPE, &sa, 0) == -1) {
 209         perror("failed to ignore SIGPIPE; sigaction");
 210         goto err;
 211     }
 212
 213     sa_quit.sa_handler = ivshmem_server_quit_cb;
 214     sa_quit.sa_flags = 0;
 215     if (sigemptyset(&sa_quit.sa_mask) == -1 ||
 216         sigaction(SIGTERM, &sa_quit, 0) == -1) {
 217         perror("failed to add SIGTERM handler; sigaction");
 218         goto err;
 219     }
 220
 221     /* init the ivshms structure */
 222     if (ivshmem_server_init(&server, args.unix_socket_path, args.shm_path,
 223                             args.shm_size, args.n_vectors, args.verbose) < 0) {
 224         fprintf(stderr, "cannot init server\n");
 225         goto err;
 226     }
 227
 228     /* start the ivshmem server (open shm & unix socket) */
 229     if (ivshmem_server_start(&server) < 0) {
 230         fprintf(stderr, "cannot bind\n");
 231         goto err;
 232     }
 233
 234     /* daemonize if asked to */
 235     if (!args.foreground) {
 236         FILE *fp;
 237
 238         if (qemu_daemon(1, 1) < 0) {
 239             fprintf(stderr, "cannot daemonize: %s\n", strerror(errno));
 240             goto err_close;
 241         }
 242
 243         /* write pid file */
 244         fp = fopen(args.pid_file, "w");
 245         if (fp == NULL) {
 246             fprintf(stderr, "cannot write pid file: %s\n", strerror(errno));
 247             goto err_close;
 248         }
 249
 250         fprintf(fp, "%d\n", (int) getpid());
 251         fclose(fp);
 252     }
 253
 254     ivshmem_server_poll_events(&server);
 255     fprintf(stdout, "server disconnected\n");
 256     ret = 0;
 257
 258 err_close:
 259     ivshmem_server_close(&server);
 260 err:
 261     return ret;
 262 }