xref: /openbmc/qemu/contrib/ivshmem-server/main.c (revision 9af9e0fe)
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 *errp = 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, &errp);
108             if (errp) {
109                 error_report_err(errp);
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 }
262