vde-2/src/vde_plug2tap.c

   1 /* Copyright 2006 Renzo Davoli
   2  * from vde_plug Davoli Gardenghi
   3  * Modified 2010 Renzo Davoli, vdestream added
   4  * Licensed under the GPLv2
   5  */
   6
   7 #include <stdio.h>
   8 #include <fcntl.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11 #include <signal.h>
  12 #include <syslog.h>
  13 #include <errno.h>
  14 #include <string.h>
  15 #include <sys/ioctl.h>
  16 #include <sys/types.h>
  17 #include <sys/stat.h>
  18 #include <stdarg.h>
  19 #include <syslog.h>
  20 #include <libgen.h>
  21 #define _GNU_SOURCE
  22 #include <getopt.h>
  23 #include <limits.h>
  24
  25 #include <config.h>
  26 #include <vde.h>
  27 #include <vdecommon.h>
  28 #include <libvdeplug.h>
  29
  30 #define BUFSIZE 2048
  31
  32 #ifdef VDE_LINUX
  33 #include <net/if.h>
  34 #include <linux/if_tun.h>
  35 #endif
  36
  37 #ifdef VDE_FREEBSD
  38 #include <sys/socket.h>
  39 #include <net/if.h>
  40 #include <net/if_tun.h>
  41 #endif
  42
  43 #if defined(VDE_DARWIN) || defined(VDE_FREEBSD)
  44 #       define TAP_PREFIX "/dev/"
  45 #       if defined HAVE_SYSLIMITS_H
  46 #               include <syslimits.h>
  47 #       elif defined HAVE_SYS_SYSLIMITS_H
  48 #               include <sys/syslimits.h>
  49 #       else
  50 #               error "No syslimits.h found"
  51 #       endif
  52 #endif
  53
  54 VDECONN *conn;
  55 VDESTREAM *vdestream;
  56
  57 char *prog;
  58 int logok;
  59 static char *pidfile = NULL;
  60 static char pidfile_path[PATH_MAX];
  61
  62 void printlog(int priority, const char *format, ...)
  63 {
  64         va_list arg;
  65
  66         va_start (arg, format);
  67
  68         if (logok)
  69                 vsyslog(priority,format,arg);
  70         else {
  71                 fprintf(stderr,"%s: ",prog);
  72                 vfprintf(stderr,format,arg);
  73                 fprintf(stderr,"\n");
  74         }
  75         va_end (arg);
  76 }
  77
  78 static void cleanup(void)
  79 {
  80         if((pidfile != NULL) && unlink(pidfile_path) < 0) {
  81                 printlog(LOG_WARNING,"Couldn't remove pidfile '%s': %s", pidfile, strerror(errno));
  82         }
  83
  84         if (vdestream != NULL)
  85                 vdestream_close(vdestream);
  86         if (conn != NULL)
  87                 vde_close(conn);
  88 }
  89
  90 static void sig_handler(int sig)
  91 {
  92         cleanup();
  93         signal(sig, SIG_DFL);
  94         if (sig == SIGTERM)
  95                 _exit(0);
  96         else
  97                 kill(getpid(), sig);
  98 }
  99
 100 static void setsighandlers()
 101 {
 102         /* setting signal handlers.
 103          * sets clean termination for SIGHUP, SIGINT and SIGTERM, and simply
 104          * ignores all the others signals which could cause termination. */
 105         struct { int sig; const char *name; int ignore; } signals[] = {
 106                 { SIGHUP, "SIGHUP", 0 },
 107                 { SIGINT, "SIGINT", 0 },
 108                 { SIGPIPE, "SIGPIPE", 1 },
 109                 { SIGALRM, "SIGALRM", 1 },
 110                 { SIGTERM, "SIGTERM", 0 },
 111                 { SIGUSR1, "SIGUSR1", 1 },
 112                 { SIGUSR2, "SIGUSR2", 1 },
 113                 { SIGPROF, "SIGPROF", 1 },
 114                 { SIGVTALRM, "SIGVTALRM", 1 },
 115 #ifdef VDE_LINUX
 116                 { SIGPOLL, "SIGPOLL", 1 },
 117 #ifdef SIGSTKFLT
 118                 { SIGSTKFLT, "SIGSTKFLT", 1 },
 119 #endif
 120                 { SIGIO, "SIGIO", 1 },
 121                 { SIGPWR, "SIGPWR", 1 },
 122 #ifdef SIGUNUSED
 123                 { SIGUNUSED, "SIGUNUSED", 1 },
 124 #endif
 125 #endif
 126 #ifdef VDE_DARWIN
 127                 { SIGXCPU, "SIGXCPU", 1 },
 128                 { SIGXFSZ, "SIGXFSZ", 1 },
 129 #endif
 130                 { 0, NULL, 0 }
 131         };
 132
 133         int i;
 134         for(i = 0; signals[i].sig != 0; i++)
 135                 if(signal(signals[i].sig,
 136                                         signals[i].ignore ? SIG_IGN : sig_handler) < 0)
 137                         perror("Setting handler");
 138 }
 139
 140 static void usage(void) {
 141         fprintf(stderr, "Usage: %s [OPTION]... tap_name\n\n", prog);
 142         fprintf(stderr, "  -p, --port=portnum          Port number in the VDE switch\n"
 143                                 "  -g, --group=group           Group for the socket\n"
 144                                         "  -m, --mode=mode             Octal mode for the socket\n"
 145                                         "  -s, --sock=socket           VDE switch control socket or dir\n"
 146                                         "  -d, --daemon                Launch in background\n"
 147                                         "  -P, --pidfile=pidfile       Create pidfile with our PID\n"
 148                                         "  -h, --help                  This help\n");
 149         exit(-1);
 150 }
 151
 152 #ifdef VDE_LINUX
 153 int open_tap(char *dev)
 154 {
 155         struct ifreq ifr;
 156         int fd;
 157
 158         if((fd = open("/dev/net/tun", O_RDWR)) < 0){
 159                 printlog(LOG_ERR,"Failed to open /dev/net/tun %s",strerror(errno));
 160                 return(-1);
 161         }
 162         memset(&ifr, 0, sizeof(ifr));
 163         ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
 164         strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name) - 1);
 165         /*printf("dev=\"%s\", ifr.ifr_name=\"%s\"\n", ifr.ifr_name, dev);*/
 166         if(ioctl(fd, TUNSETIFF, (void *) &ifr) < 0){
 167                 printlog(LOG_ERR,"TUNSETIFF failed %s",strerror(errno));
 168                 close(fd);
 169                 return(-1);
 170         }
 171         return(fd);
 172 }
 173 #endif
 174
 175 #if defined(VDE_DARWIN) || defined(VDE_FREEBSD)
 176 int open_tap(char *dev)
 177 {
 178         int fd;
 179         int prefixlen = strlen(TAP_PREFIX);
 180         char *path = NULL;
 181         if (*dev == '/')
 182                 fd=open(dev, O_RDWR);
 183         else
 184         {
 185                 path = malloc(strlen(dev) + prefixlen + 1);
 186                 if (path != NULL)
 187                 {
 188                         snprintf(path, strlen(dev) + prefixlen + 1, "%s%s", TAP_PREFIX, dev);
 189                         fd=open(path, O_RDWR);
 190                         free(path);
 191                 }
 192                 else
 193                         fd = -1;
 194         }
 195
 196         if (fd < 0)
 197         {
 198                 printlog(LOG_ERR,"Failed to open tap device %s: %s", (*dev == '/') ? dev : path, strerror(errno));
 199                 return(-1);
 200         }
 201         return fd;
 202 }
 203 #endif
 204
 205 unsigned char bufin[BUFSIZE];
 206
 207 static void save_pidfile()
 208 {
 209         if(pidfile[0] != '/')
 210                 strncat(pidfile_path, pidfile, PATH_MAX - strlen(pidfile_path));
 211         else
 212                 strcpy(pidfile_path, pidfile);
 213
 214         int fd = open(pidfile_path,
 215                         O_WRONLY | O_CREAT | O_EXCL,
 216                         S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 217         FILE *f;
 218
 219         if(fd == -1) {
 220                 printlog(LOG_ERR, "Error in pidfile creation: %s", strerror(errno));
 221                 exit(1);
 222         }
 223
 224         if((f = fdopen(fd, "w")) == NULL) {
 225                 printlog(LOG_ERR, "Error in FILE* construction: %s", strerror(errno));
 226                 exit(1);
 227         }
 228
 229         if(fprintf(f, "%ld\n", (long int)getpid()) <= 0) {
 230                 printlog(LOG_ERR, "Error in writing pidfile");
 231                 exit(1);
 232         }
 233
 234         fclose(f);
 235 }
 236
 237 static ssize_t vde_plug2tap_recv(void *opaque, void *buf, size_t count)
 238 {
 239         int *tapfdp=opaque;
 240         return write(*tapfdp,buf,count);
 241 }
 242
 243 int main(int argc, char **argv)
 244 {
 245         static char *sockname=NULL;
 246         static char *tapname=NULL;
 247         int daemonize=0;
 248         int tapfd;
 249         register ssize_t nx;
 250         struct vde_open_args open_args={.port=0,.group=NULL,.mode=0700};
 251         int c;
 252         static struct pollfd pollv[]={{0,POLLIN|POLLHUP},
 253                 {0,POLLIN|POLLHUP},
 254                 {0,POLLIN|POLLHUP}};
 255         int npollv;
 256
 257         prog=argv[0];
 258         while (1) {
 259                 int option_index = 0;
 260
 261                 static struct option long_options[] = {
 262                         {"sock", 1, 0, 's'},
 263                         {"port", 1, 0, 'p'},
 264                         {"help",0,0,'h'},
 265                         {"mod",1,0,'m'},
 266                         {"group",1,0,'g'},
 267                         {"daemon",0,0,'d'},
 268                         {"pidfile", 1, 0, 'P'},
 269                         {0, 0, 0, 0}
 270                 };
 271                 c = GETOPT_LONG (argc, argv, "hdP:p:s:m:g:",
 272                                 long_options, &option_index);
 273                 if (c == -1)
 274                         break;
 275
 276                 switch (c) {
 277                         case 'p':
 278                                 open_args.port=atoi(optarg);
 279                                 if (open_args.port <= 0)
 280                                         usage(); //implies exit
 281                                 break;
 282
 283                         case 'h':
 284                                 usage(); //implies exit
 285                                 break;
 286
 287                         case 's':
 288                                 sockname=strdup(optarg);
 289                                 break;
 290
 291                         case 'm':
 292                                 sscanf(optarg,"%o",(unsigned int *)&(open_args.mode));
 293                                 break;
 294
 295                         case 'g':
 296                                 open_args.group=strdup(optarg);
 297                                 break;
 298
 299                         case 'd':
 300                                 daemonize=1;
 301                                 break;
 302
 303                         case 'P':
 304                                 pidfile=strdup(optarg);
 305                                 break;
 306
 307                         default:
 308                                 usage(); //implies exit
 309                 }
 310         }
 311
 312         if (daemonize) {
 313                 openlog(basename(prog), LOG_PID, 0);
 314                 logok=1;
 315                 syslog(LOG_INFO,"VDE_PLUG2TAP started");
 316         }
 317         /* saves current path in pidfile_path, because otherwise with daemonize() we
 318          * forget it */
 319         if(getcwd(pidfile_path, PATH_MAX-1) == NULL) {
 320                 printlog(LOG_ERR, "getcwd: %s", strerror(errno));
 321                 exit(1);
 322         }
 323         strcat(pidfile_path, "/");
 324         if (daemonize && daemon(0, 0)) {
 325                 printlog(LOG_ERR,"daemon: %s",strerror(errno));
 326                 exit(1);
 327         }
 328
 329         /* once here, we're sure we're the true process which will continue as a
 330          * server: save PID file if needed */
 331         if(pidfile) save_pidfile();
 332
 333         if (optind < argc)
 334                 tapname=argv[optind];
 335         else
 336                 usage(); // implies exit
 337
 338         atexit(cleanup);
 339         setsighandlers();
 340
 341         tapfd=open_tap(tapname);
 342         if(tapfd<0)
 343                 exit(1);
 344         pollv[0].fd=tapfd;
 345
 346         if (sockname==NULL || strcmp(sockname,"-") != 0) {
 347                 conn=vde_open(sockname,"vde_plug2tap:",&open_args);
 348                 if (conn == NULL) {
 349                         printlog(LOG_ERR,"vde_open %s: %s",sockname?sockname:"DEF_SWITCH",strerror(errno));
 350                         exit(1);
 351                 }
 352                 pollv[1].fd=vde_datafd(conn);
 353                 pollv[2].fd=vde_ctlfd(conn);
 354                 npollv=3;
 355         } else {
 356                 vdestream=vdestream_open(&tapfd,STDOUT_FILENO,vde_plug2tap_recv,NULL);
 357                 if (vdestream == NULL)
 358                         exit(1);
 359                 pollv[1].fd=STDIN_FILENO;
 360                 npollv=2;
 361         }
 362
 363         for(;;) {
 364                 poll(pollv,3,-1);
 365                 if ((pollv[0].revents | pollv[1].revents | pollv[2].revents) & POLLHUP ||
 366                                 (npollv > 2 && pollv[2].revents & POLLIN))
 367                         break;
 368                 if (pollv[0].revents & POLLIN) {
 369                         nx=read(tapfd,bufin,sizeof(bufin));
 370                         /* if POLLIN but not data it means that the stream has been
 371                          * closed at the other end */
 372                         //fprintf(stderr,"%s: RECV %d %x %x \n",prog,nx,bufin[0],bufin[1]);
 373                         if (nx<=0)
 374                                 break;
 375                         if (conn != NULL)
 376                                 vde_send(conn,bufin,nx,0);
 377                         else
 378                                 vdestream_send(vdestream, bufin, nx);
 379                 }
 380                 if (pollv[1].revents & POLLIN) {
 381                         if (conn != NULL) {
 382                                 nx=vde_recv(conn,bufin,sizeof(bufin),0);
 383                                 if (nx<=0)
 384                                         break;
 385                                 write(tapfd,bufin,nx);
 386                         } else {
 387                                 nx=read(STDIN_FILENO,bufin,sizeof(bufin));
 388                                 if (nx<=0)
 389                                         break;
 390                                 vdestream_recv(vdestream,bufin,nx);
 391                         }
 392                         //fprintf(stderr,"%s: SENT %d %x %x \n",prog,nx,bufin[0],bufin[1]);
 393                 }
 394
 395         }
 396         return(0);
 397 }