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 "qapi/error.h"
  11 #include "qemu-common.h"
  12
  13 #include "ivshmem-server.h"
  14
  15 #define IVSHMEM_SERVER_DEFAULT_VERBOSE        0
  16 #define IVSHMEM_SERVER_DEFAULT_FOREGROUND     0
  17 #define IVSHMEM_SERVER_DEFAULT_PID_FILE       "/var/run/ivshmem-server.pid"
  18 #define IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "/tmp/ivshmem_socket"
  19 #define IVSHMEM_SERVER_DEFAULT_SHM_PATH       "ivshmem"
  20 #define IVSHMEM_SERVER_DEFAULT_SHM_SIZE       (4*1024*1024)
  21 #define IVSHMEM_SERVER_DEFAULT_N_VECTORS      1
  22
  23 /* used to quit on signal SIGTERM */
  24 static int ivshmem_server_quit;
  25
  26 /* arguments given by the user */
  27 typedef struct IvshmemServerArgs {
  28     bool verbose;
  29     bool foreground;
  30     const char *pid_file;
  31     const char *unix_socket_path;
  32     const char *shm_path;
  33     uint64_t shm_size;
  34     unsigned n_vectors;
  35 } IvshmemServerArgs;
  36
  37 /* show ivshmem_server_usage and exit with given error code */
  38 static void
  39 ivshmem_server_usage(const char *name, int code)
  40 {
  41     fprintf(stderr, "%s [opts]\n", name);
  42     fprintf(stderr, "  -h: show this help\n");
  43     fprintf(stderr, "  -v: verbose mode\n");
  44     fprintf(stderr, "  -F: foreground mode (default is to daemonize)\n");
  45     fprintf(stderr, "  -p <pid_file>: path to the PID file (used in daemon\n"
  46                     "     mode only).\n"
  47                     "     Default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH);
  48     fprintf(stderr, "  -S <unix_socket_path>: path to the unix socket\n"
  49                     "     to listen to.\n"
  50                     "     Default=%s\n", IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH);
  51     fprintf(stderr, "  -m <shm_path>: path to the shared memory.\n"
  52                     "     The path corresponds to a POSIX shm name or a\n"
  53                     "     hugetlbfs mount point.\n"
  54                     "     default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH);
  55     fprintf(stderr, "  -l <size>: size of shared memory in bytes. The suffix\n"
  56                     "     K, M and G can be used (ex: 1K means 1024).\n"
  57                     "     default=%u\n", IVSHMEM_SERVER_DEFAULT_SHM_SIZE);
  58     fprintf(stderr, "  -n <n_vects>: number of vectors.\n"
  59                     "     default=%u\n", IVSHMEM_SERVER_DEFAULT_N_VECTORS);
  60
  61     exit(code);
  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,
  73                        "h"  /* help */
  74                        "v"  /* verbose */
  75                        "F"  /* foreground */
  76                        "p:" /* pid_file */
  77                        "S:" /* unix_socket_path */
  78                        "m:" /* shm_path */
  79                        "l:" /* shm_size */
  80                        "n:" /* n_vectors */
  81                       )) != -1) {
  82
  83         switch (c) {
  84         case 'h': /* help */
  85             ivshmem_server_usage(argv[0], 0);
  86             break;
  87
  88         case 'v': /* verbose */
  89             args->verbose = 1;
  90             break;
  91
  92         case 'F': /* foreground */
  93             args->foreground = 1;
  94             break;
  95
  96         case 'p': /* pid_file */
  97             args->pid_file = optarg;
  98             break;
  99
 100         case 'S': /* unix_socket_path */
 101             args->unix_socket_path = optarg;
 102             break;
 103
 104         case 'm': /* shm_path */
 105             args->shm_path = optarg;
 106             break;
 107
 108         case 'l': /* shm_size */
 109             parse_option_size("shm_size", optarg, &args->shm_size, &err);
 110             if (err) {
 111                 error_report_err(err);
 112                 ivshmem_server_usage(argv[0], 1);
 113             }
 114             break;
 115
 116         case 'n': /* n_vectors */
 117             if (parse_uint_full(optarg, &v, 0) < 0) {
 118                 fprintf(stderr, "cannot parse n_vectors\n");
 119                 ivshmem_server_usage(argv[0], 1);
 120             }
 121             args->n_vectors = v;
 122             break;
 123
 124         default:
 125             ivshmem_server_usage(argv[0], 1);
 126             break;
 127         }
 128     }
 129
 130     if (args->n_vectors > IVSHMEM_SERVER_MAX_VECTORS) {
 131         fprintf(stderr, "too many requested vectors (max is %d)\n",
 132                 IVSHMEM_SERVER_MAX_VECTORS);
 133         ivshmem_server_usage(argv[0], 1);
 134     }
 135
 136     if (args->verbose == 1 && args->foreground == 0) {
 137         fprintf(stderr, "cannot use verbose in daemon mode\n");
 138         ivshmem_server_usage(argv[0], 1);
 139     }
 140 }
 141
 142 /* wait for events on listening server unix socket and connected client
 143  * sockets */
 144 static int
 145 ivshmem_server_poll_events(IvshmemServer *server)
 146 {
 147     fd_set fds;
 148     int ret = 0, maxfd;
 149
 150     while (!ivshmem_server_quit) {
 151
 152         FD_ZERO(&fds);
 153         maxfd = 0;
 154         ivshmem_server_get_fds(server, &fds, &maxfd);
 155
 156         ret = select(maxfd, &fds, NULL, NULL, NULL);
 157
 158         if (ret < 0) {
 159             if (errno == EINTR) {
 160                 continue;
 161             }
 162
 163             fprintf(stderr, "select error: %s\n", strerror(errno));
 164             break;
 165         }
 166         if (ret == 0) {
 167             continue;
 168         }
 169
 170         if (ivshmem_server_handle_fds(server, &fds, maxfd) < 0) {
 171             fprintf(stderr, "ivshmem_server_handle_fds() failed\n");
 172             break;
 173         }
 174     }
 175
 176     return ret;
 177 }
 178
 179 static void
 180 ivshmem_server_quit_cb(int signum)
 181 {
 182     ivshmem_server_quit = 1;
 183 }
 184
 185 int
 186 main(int argc, char *argv[])
 187 {
 188     IvshmemServer server;
 189     struct sigaction sa, sa_quit;
 190     IvshmemServerArgs args = {
 191         .verbose = IVSHMEM_SERVER_DEFAULT_VERBOSE,
 192         .foreground = IVSHMEM_SERVER_DEFAULT_FOREGROUND,
 193         .pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE,
 194         .unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH,
 195         .shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH,
 196         .shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
 197         .n_vectors = IVSHMEM_SERVER_DEFAULT_N_VECTORS,
 198     };
 199     int ret = 1;
 200
 201     /* parse arguments, will exit on error */
 202     ivshmem_server_parse_args(&args, argc, argv);
 203
 204     /* Ignore SIGPIPE, see this link for more info:
 205      * http://www.mail-archive.com/libevent-users@monkey.org/msg01606.html */
 206     sa.sa_handler = SIG_IGN;
 207     sa.sa_flags = 0;
 208     if (sigemptyset(&sa.sa_mask) == -1 ||
 209         sigaction(SIGPIPE, &sa, 0) == -1) {
 210         perror("failed to ignore SIGPIPE; sigaction");
 211         goto err;
 212     }
 213
 214     sa_quit.sa_handler = ivshmem_server_quit_cb;
 215     sa_quit.sa_flags = 0;
 216     if (sigemptyset(&sa_quit.sa_mask) == -1 ||
 217         sigaction(SIGTERM, &sa_quit, 0) == -1) {
 218         perror("failed to add SIGTERM handler; sigaction");
 219         goto err;
 220     }
 221
 222     /* init the ivshms structure */
 223     if (ivshmem_server_init(&server, args.unix_socket_path, args.shm_path,
 224                             args.shm_size, args.n_vectors, args.verbose) < 0) {
 225         fprintf(stderr, "cannot init server\n");
 226         goto err;
 227     }
 228
 229     /* start the ivshmem server (open shm & unix socket) */
 230     if (ivshmem_server_start(&server) < 0) {
 231         fprintf(stderr, "cannot bind\n");
 232         goto err;
 233     }
 234
 235     /* daemonize if asked to */
 236     if (!args.foreground) {
 237         FILE *fp;
 238
 239         if (qemu_daemon(1, 1) < 0) {
 240             fprintf(stderr, "cannot daemonize: %s\n", strerror(errno));
 241             goto err_close;
 242         }
 243
 244         /* write pid file */
 245         fp = fopen(args.pid_file, "w");
 246         if (fp == NULL) {
 247             fprintf(stderr, "cannot write pid file: %s\n", strerror(errno));
 248             goto err_close;
 249         }
 250
 251         fprintf(fp, "%d\n", (int) getpid());
 252         fclose(fp);
 253     }
 254
 255     ivshmem_server_poll_events(&server);
 256     fprintf(stdout, "server disconnected\n");
 257     ret = 0;
 258
 259 err_close:
 260     ivshmem_server_close(&server);
 261 err:
 262     return ret;
 263 }