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-common.h"
  10
  11 #include "ivshmem-server.h"
  12
  13 #define IVSHMEM_SERVER_DEFAULT_VERBOSE        0
  14 #define IVSHMEM_SERVER_DEFAULT_FOREGROUND     0
  15 #define IVSHMEM_SERVER_DEFAULT_PID_FILE       "/var/run/ivshmem-server.pid"
  16 #define IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "/tmp/ivshmem_socket"
  17 #define IVSHMEM_SERVER_DEFAULT_SHM_PATH       "ivshmem"
  18 #define IVSHMEM_SERVER_DEFAULT_SHM_SIZE       (4*1024*1024)
  19 #define IVSHMEM_SERVER_DEFAULT_N_VECTORS      1
  20
  21 /* used to quit on signal SIGTERM */
  22 static int ivshmem_server_quit;
  23
  24 /* arguments given by the user */
  25 typedef struct IvshmemServerArgs {
  26     bool verbose;
  27     bool foreground;
  28     const char *pid_file;
  29     const char *unix_socket_path;
  30     const char *shm_path;
  31     uint64_t shm_size;
  32     unsigned n_vectors;
  33 } IvshmemServerArgs;
  34
  35 /* show ivshmem_server_usage and exit with given error code */
  36 static void
  37 ivshmem_server_usage(const char *name, int code)
  38 {
  39     fprintf(stderr, "%s [opts]\n", name);
  40     fprintf(stderr, "  -h: show this help\n");
  41     fprintf(stderr, "  -v: verbose mode\n");
  42     fprintf(stderr, "  -F: foreground mode (default is to daemonize)\n");
  43     fprintf(stderr, "  -p <pid_file>: path to the PID file (used in daemon\n"
  44                     "     mode only).\n"
  45                     "     Default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH);
  46     fprintf(stderr, "  -S <unix_socket_path>: path to the unix socket\n"
  47                     "     to listen to.\n"
  48                     "     Default=%s\n", IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH);
  49     fprintf(stderr, "  -m <shm_path>: path to the shared memory.\n"
  50                     "     The path corresponds to a POSIX shm name or a\n"
  51                     "     hugetlbfs mount point.\n"
  52                     "     default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH);
  53     fprintf(stderr, "  -l <size>: size of shared memory in bytes. The suffix\n"
  54                     "     K, M and G can be used (ex: 1K means 1024).\n"
  55                     "     default=%u\n", IVSHMEM_SERVER_DEFAULT_SHM_SIZE);
  56     fprintf(stderr, "  -n <n_vects>: number of vectors.\n"
  57                     "     default=%u\n", IVSHMEM_SERVER_DEFAULT_N_VECTORS);
  58
  59     exit(code);
  60 }
  61
  62 /* parse the program arguments, exit on error */
  63 static void
  64 ivshmem_server_parse_args(IvshmemServerArgs *args, int argc, char *argv[])
  65 {
  66     int c;
  67     unsigned long long v;
  68     Error *err = NULL;
  69
  70     while ((c = getopt(argc, argv,
  71                        "h"  /* help */
  72                        "v"  /* verbose */
  73                        "F"  /* foreground */
  74                        "p:" /* pid_file */
  75                        "S:" /* unix_socket_path */
  76                        "m:" /* shm_path */
  77                        "l:" /* shm_size */
  78                        "n:" /* n_vectors */
  79                       )) != -1) {
  80
  81         switch (c) {
  82         case 'h': /* help */
  83             ivshmem_server_usage(argv[0], 0);
  84             break;
  85
  86         case 'v': /* verbose */
  87             args->verbose = 1;
  88             break;
  89
  90         case 'F': /* foreground */
  91             args->foreground = 1;
  92             break;
  93
  94         case 'p': /* pid_file */
  95             args->pid_file = optarg;
  96             break;
  97
  98         case 'S': /* unix_socket_path */
  99             args->unix_socket_path = optarg;
 100             break;
 101
 102         case 'm': /* shm_path */
 103             args->shm_path = optarg;
 104             break;
 105
 106         case 'l': /* shm_size */
 107             parse_option_size("shm_size", optarg, &args->shm_size, &err);
 108             if (err) {
 109                 error_report_err(err);
 110                 ivshmem_server_usage(argv[0], 1);
 111             }
 112             break;
 113
 114         case 'n': /* n_vectors */
 115             if (parse_uint_full(optarg, &v, 0) < 0) {
 116                 fprintf(stderr, "cannot parse n_vectors\n");
 117                 ivshmem_server_usage(argv[0], 1);
 118             }
 119             args->n_vectors = v;
 120             break;
 121
 122         default:
 123             ivshmem_server_usage(argv[0], 1);
 124             break;
 125         }
 126     }
 127
 128     if (args->n_vectors > IVSHMEM_SERVER_MAX_VECTORS) {
 129         fprintf(stderr, "too many requested vectors (max is %d)\n",
 130                 IVSHMEM_SERVER_MAX_VECTORS);
 131         ivshmem_server_usage(argv[0], 1);
 132     }
 133
 134     if (args->verbose == 1 && args->foreground == 0) {
 135         fprintf(stderr, "cannot use verbose in daemon mode\n");
 136         ivshmem_server_usage(argv[0], 1);
 137     }
 138 }
 139
 140 /* wait for events on listening server unix socket and connected client
 141  * sockets */
 142 static int
 143 ivshmem_server_poll_events(IvshmemServer *server)
 144 {
 145     fd_set fds;
 146     int ret = 0, maxfd;
 147
 148     while (!ivshmem_server_quit) {
 149
 150         FD_ZERO(&fds);
 151         maxfd = 0;
 152         ivshmem_server_get_fds(server, &fds, &maxfd);
 153
 154         ret = select(maxfd, &fds, NULL, NULL, NULL);
 155
 156         if (ret < 0) {
 157             if (errno == EINTR) {
 158                 continue;
 159             }
 160
 161             fprintf(stderr, "select error: %s\n", strerror(errno));
 162             break;
 163         }
 164         if (ret == 0) {
 165             continue;
 166         }
 167
 168         if (ivshmem_server_handle_fds(server, &fds, maxfd) < 0) {
 169             fprintf(stderr, "ivshmem_server_handle_fds() failed\n");
 170             break;
 171         }
 172     }
 173
 174     return ret;
 175 }
 176
 177 static void
 178 ivshmem_server_quit_cb(int signum)
 179 {
 180     ivshmem_server_quit = 1;
 181 }
 182
 183 int
 184 main(int argc, char *argv[])
 185 {
 186     IvshmemServer server;
 187     struct sigaction sa, sa_quit;
 188     IvshmemServerArgs args = {
 189         .verbose = IVSHMEM_SERVER_DEFAULT_VERBOSE,
 190         .foreground = IVSHMEM_SERVER_DEFAULT_FOREGROUND,
 191         .pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE,
 192         .unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH,
 193         .shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH,
 194         .shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
 195         .n_vectors = IVSHMEM_SERVER_DEFAULT_N_VECTORS,
 196     };
 197     int ret = 1;
 198
 199     /* parse arguments, will exit on error */
 200     ivshmem_server_parse_args(&args, argc, argv);
 201
 202     /* Ignore SIGPIPE, see this link for more info:
 203      * http://www.mail-archive.com/libevent-users@monkey.org/msg01606.html */
 204     sa.sa_handler = SIG_IGN;
 205     sa.sa_flags = 0;
 206     if (sigemptyset(&sa.sa_mask) == -1 ||
 207         sigaction(SIGPIPE, &sa, 0) == -1) {
 208         perror("failed to ignore SIGPIPE; sigaction");
 209         goto err;
 210     }
 211
 212     sa_quit.sa_handler = ivshmem_server_quit_cb;
 213     sa_quit.sa_flags = 0;
 214     if (sigemptyset(&sa_quit.sa_mask) == -1 ||
 215         sigaction(SIGTERM, &sa_quit, 0) == -1) {
 216         perror("failed to add SIGTERM handler; sigaction");
 217         goto err;
 218     }
 219
 220     /* init the ivshms structure */
 221     if (ivshmem_server_init(&server, args.unix_socket_path, args.shm_path,
 222                             args.shm_size, args.n_vectors, args.verbose) < 0) {
 223         fprintf(stderr, "cannot init server\n");
 224         goto err;
 225     }
 226
 227     /* start the ivshmem server (open shm & unix socket) */
 228     if (ivshmem_server_start(&server) < 0) {
 229         fprintf(stderr, "cannot bind\n");
 230         goto err;
 231     }
 232
 233     /* daemonize if asked to */
 234     if (!args.foreground) {
 235         FILE *fp;
 236
 237         if (qemu_daemon(1, 1) < 0) {
 238             fprintf(stderr, "cannot daemonize: %s\n", strerror(errno));
 239             goto err_close;
 240         }
 241
 242         /* write pid file */
 243         fp = fopen(args.pid_file, "w");
 244         if (fp == NULL) {
 245             fprintf(stderr, "cannot write pid file: %s\n", strerror(errno));
 246             goto err_close;
 247         }
 248
 249         fprintf(fp, "%d\n", (int) getpid());
 250         fclose(fp);
 251     }
 252
 253     ivshmem_server_poll_events(&server);
 254     fprintf(stdout, "server disconnected\n");
 255     ret = 0;
 256
 257 err_close:
 258     ivshmem_server_close(&server);
 259 err:
 260     return ret;
 261 }