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 static void
  37 ivshmem_server_usage(const char *progname)
  38 {
  39     printf("Usage: %s [OPTION]...\n"
  40            "  -h: show this help\n"
  41            "  -v: verbose mode\n"
  42            "  -F: foreground mode (default is to daemonize)\n"
  43            "  -p <pid-file>: path to the PID file (used in daemon mode only)\n"
  44            "     default " IVSHMEM_SERVER_DEFAULT_PID_FILE "\n"
  45            "  -S <unix-socket-path>: path to the unix socket to listen to\n"
  46            "     default " IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "\n"
  47            "  -m <shm-path>: POSIX shared memory object name or a hugetlbfs mount point\n"
  48            "     default " IVSHMEM_SERVER_DEFAULT_SHM_PATH "\n"
  49            "  -l <size>: size of shared memory in bytes\n"
  50            "     suffixes K, M and G can be used, e.g. 1K means 1024\n"
  51            "     default %u\n"
  52            "  -n <nvectors>: number of vectors\n"
  53            "     default %u\n",
  54            progname, IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
  55            IVSHMEM_SERVER_DEFAULT_N_VECTORS);
  56 }
  57
  58 static void
  59 ivshmem_server_help(const char *progname)
  60 {
  61     fprintf(stderr, "Try '%s -h' for more information.\n", progname);
  62 }
  63
  64 /* parse the program arguments, exit on error */
  65 static void
  66 ivshmem_server_parse_args(IvshmemServerArgs *args, int argc, char *argv[])
  67 {
  68     int c;
  69     unsigned long long v;
  70     Error *err = NULL;
  71
  72     while ((c = getopt(argc, argv, "hvFp:S:m:l:n:")) != -1) {
  73
  74         switch (c) {
  75         case 'h': /* help */
  76             ivshmem_server_usage(argv[0]);
  77             exit(0);
  78             break;
  79
  80         case 'v': /* verbose */
  81             args->verbose = 1;
  82             break;
  83
  84         case 'F': /* foreground */
  85             args->foreground = 1;
  86             break;
  87
  88         case 'p': /* pid file */
  89             args->pid_file = optarg;
  90             break;
  91
  92         case 'S': /* unix socket path */
  93             args->unix_socket_path = optarg;
  94             break;
  95
  96         case 'm': /* shm path */
  97             args->shm_path = optarg;
  98             break;
  99
 100         case 'l': /* shm size */
 101             parse_option_size("shm_size", optarg, &args->shm_size, &err);
 102             if (err) {
 103                 error_report_err(err);
 104                 ivshmem_server_help(argv[0]);
 105                 exit(1);
 106             }
 107             break;
 108
 109         case 'n': /* number of vectors */
 110             if (parse_uint_full(optarg, &v, 0) < 0) {
 111                 fprintf(stderr, "cannot parse n_vectors\n");
 112                 ivshmem_server_help(argv[0]);
 113                 exit(1);
 114             }
 115             args->n_vectors = v;
 116             break;
 117
 118         default:
 119             ivshmem_server_usage(argv[0]);
 120             exit(1);
 121             break;
 122         }
 123     }
 124
 125     if (args->n_vectors > IVSHMEM_SERVER_MAX_VECTORS) {
 126         fprintf(stderr, "too many requested vectors (max is %d)\n",
 127                 IVSHMEM_SERVER_MAX_VECTORS);
 128         ivshmem_server_help(argv[0]);
 129         exit(1);
 130     }
 131
 132     if (args->verbose == 1 && args->foreground == 0) {
 133         fprintf(stderr, "cannot use verbose in daemon mode\n");
 134         ivshmem_server_help(argv[0]);
 135         exit(1);
 136     }
 137 }
 138
 139 /* wait for events on listening server unix socket and connected client
 140  * sockets */
 141 static int
 142 ivshmem_server_poll_events(IvshmemServer *server)
 143 {
 144     fd_set fds;
 145     int ret = 0, maxfd;
 146
 147     while (!ivshmem_server_quit) {
 148
 149         FD_ZERO(&fds);
 150         maxfd = 0;
 151         ivshmem_server_get_fds(server, &fds, &maxfd);
 152
 153         ret = select(maxfd, &fds, NULL, NULL, NULL);
 154
 155         if (ret < 0) {
 156             if (errno == EINTR) {
 157                 continue;
 158             }
 159
 160             fprintf(stderr, "select error: %s\n", strerror(errno));
 161             break;
 162         }
 163         if (ret == 0) {
 164             continue;
 165         }
 166
 167         if (ivshmem_server_handle_fds(server, &fds, maxfd) < 0) {
 168             fprintf(stderr, "ivshmem_server_handle_fds() failed\n");
 169             break;
 170         }
 171     }
 172
 173     return ret;
 174 }
 175
 176 static void
 177 ivshmem_server_quit_cb(int signum)
 178 {
 179     ivshmem_server_quit = 1;
 180 }
 181
 182 int
 183 main(int argc, char *argv[])
 184 {
 185     IvshmemServer server;
 186     struct sigaction sa, sa_quit;
 187     IvshmemServerArgs args = {
 188         .verbose = IVSHMEM_SERVER_DEFAULT_VERBOSE,
 189         .foreground = IVSHMEM_SERVER_DEFAULT_FOREGROUND,
 190         .pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE,
 191         .unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH,
 192         .shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH,
 193         .shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
 194         .n_vectors = IVSHMEM_SERVER_DEFAULT_N_VECTORS,
 195     };
 196     int ret = 1;
 197
 198     /* parse arguments, will exit on error */
 199     ivshmem_server_parse_args(&args, argc, argv);
 200
 201     /* Ignore SIGPIPE, see this link for more info:
 202      * http://www.mail-archive.com/libevent-users@monkey.org/msg01606.html */
 203     sa.sa_handler = SIG_IGN;
 204     sa.sa_flags = 0;
 205     if (sigemptyset(&sa.sa_mask) == -1 ||
 206         sigaction(SIGPIPE, &sa, 0) == -1) {
 207         perror("failed to ignore SIGPIPE; sigaction");
 208         goto err;
 209     }
 210
 211     sa_quit.sa_handler = ivshmem_server_quit_cb;
 212     sa_quit.sa_flags = 0;
 213     if (sigemptyset(&sa_quit.sa_mask) == -1 ||
 214         sigaction(SIGTERM, &sa_quit, 0) == -1) {
 215         perror("failed to add SIGTERM handler; sigaction");
 216         goto err;
 217     }
 218
 219     /* init the ivshms structure */
 220     if (ivshmem_server_init(&server, args.unix_socket_path, args.shm_path,
 221                             args.shm_size, args.n_vectors, args.verbose) < 0) {
 222         fprintf(stderr, "cannot init server\n");
 223         goto err;
 224     }
 225
 226     /* start the ivshmem server (open shm & unix socket) */
 227     if (ivshmem_server_start(&server) < 0) {
 228         fprintf(stderr, "cannot bind\n");
 229         goto err;
 230     }
 231
 232     /* daemonize if asked to */
 233     if (!args.foreground) {
 234         FILE *fp;
 235
 236         if (qemu_daemon(1, 1) < 0) {
 237             fprintf(stderr, "cannot daemonize: %s\n", strerror(errno));
 238             goto err_close;
 239         }
 240
 241         /* write pid file */
 242         fp = fopen(args.pid_file, "w");
 243         if (fp == NULL) {
 244             fprintf(stderr, "cannot write pid file: %s\n", strerror(errno));
 245             goto err_close;
 246         }
 247
 248         fprintf(fp, "%d\n", (int) getpid());
 249         fclose(fp);
 250     }
 251
 252     ivshmem_server_poll_events(&server);
 253     fprintf(stdout, "server disconnected\n");
 254     ret = 0;
 255
 256 err_close:
 257     ivshmem_server_close(&server);
 258 err:
 259     return ret;
 260 }