nbd-client.c

   1 /*
   2  * Open connection for network block device
   3  *
   4  * Copyright 1997,1998 Pavel Machek, distribute under GPL
   5  *  <pavel@atrey.karlin.mff.cuni.cz>
   6  * Copyright (c) 2002 - 2011 Wouter Verhelst <w@uter.be>
   7  *
   8  * Version 1.0 - 64bit issues should be fixed, now
   9  * Version 1.1 - added bs (blocksize) option (Alexey Guzeev, aga@permonline.ru)
  10  * Version 1.2 - I added new option '-d' to send the disconnect request
  11  * Version 2.0 - Version synchronised with server
  12  * Version 2.1 - Check for disconnection before INIT_PASSWD is received
  13  *      to make errormsg a bit more helpful in case the server can't
  14  *      open the exported file.
  15  * 16/03/2010 - Add IPv6 support.
  16  *      Kitt Tientanopajai <kitt@kitty.in.th>
  17  *      Neutron Soutmun <neo.neutron@gmail.com>
  18  *      Suriya Soutmun <darksolar@gmail.com>
  19  */
  20
  21 #include "config.h"
  22 #include "lfs.h"
  23
  24 #include <sys/ioctl.h>
  25 #include <sys/socket.h>
  26 #include <sys/un.h>
  27 #include <sys/types.h>
  28 #include <unistd.h>
  29 #include <netinet/tcp.h>
  30 #include <netinet/in.h>
  31 #include <netdb.h>
  32 #include "netdb-compat.h"
  33 #include <stdio.h>
  34 #include <fcntl.h>
  35 #include <syslog.h>
  36 #include <stdlib.h>
  37 #include <sys/mount.h>
  38 #include <sys/mman.h>
  39 #include <signal.h>
  40 #include <errno.h>
  41 #include <getopt.h>
  42 #include <stdarg.h>
  43 #include <stdbool.h>
  44 #include <time.h>
  45
  46 #include <linux/ioctl.h>
  47 #define MY_NAME "nbd_client"
  48 #include "cliserv.h"
  49
  50 #if HAVE_GNUTLS
  51 #include "crypto-gnutls.h"
  52 #endif
  53
  54 #ifdef WITH_SDP
  55 #include <sdp_inet.h>
  56 #endif
  57
  58 #define NBDC_DO_LIST 1
  59
  60 int check_conn(char* devname, int do_print) {
  61         char buf[256];
  62         char* p;
  63         int fd;
  64         int len;
  65
  66         if( (p=strrchr(devname, '/')) ) {
  67                 devname=p+1;
  68         }
  69         if((p=strchr(devname, 'p'))) {
  70                 /* We can't do checks on partitions. */
  71                 *p='\0';
  72         }
  73         snprintf(buf, 256, "/sys/block/%s/pid", devname);
  74         if((fd=open(buf, O_RDONLY))<0) {
  75                 if(errno==ENOENT) {
  76                         return 1;
  77                 } else {
  78                         return 2;
  79                 }
  80         }
  81         len=read(fd, buf, 256);
  82         if(len < 0) {
  83                 perror("could not read from server");
  84                 close(fd);
  85                 return 2;
  86         }
  87         buf[(len < 256) ? len : 255]='\0';
  88         if(do_print) printf("%s\n", buf);
  89         close(fd);
  90         return 0;
  91 }
  92
  93 int opennet(char *name, char* portstr, int sdp) {
  94         int sock;
  95         struct addrinfo hints;
  96         struct addrinfo *ai = NULL;
  97         struct addrinfo *rp = NULL;
  98         int e;
  99
 100         memset(&hints,'\0',sizeof(hints));
 101         hints.ai_family = AF_UNSPEC;
 102         hints.ai_socktype = SOCK_STREAM;
 103         hints.ai_flags = AI_ADDRCONFIG | AI_NUMERICSERV;
 104         hints.ai_protocol = IPPROTO_TCP;
 105
 106         e = getaddrinfo(name, portstr, &hints, &ai);
 107
 108         if(e != 0) {
 109                 fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
 110                 freeaddrinfo(ai);
 111                 return -1;
 112         }
 113
 114         if(sdp) {
 115 #ifdef WITH_SDP
 116                 if (ai->ai_family == AF_INET)
 117                         ai->ai_family = AF_INET_SDP;
 118                 else (ai->ai_family == AF_INET6)
 119                         ai->ai_family = AF_INET6_SDP;
 120 #else
 121                 err("Can't do SDP: I was not compiled with SDP support!");
 122 #endif
 123         }
 124
 125         for(rp = ai; rp != NULL; rp = rp->ai_next) {
 126                 sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 127
 128                 if(sock == -1)
 129                         continue;       /* error */
 130
 131                 if(connect(sock, rp->ai_addr, rp->ai_addrlen) != -1)
 132                         break;          /* success */
 133
 134                 close(sock);
 135         }
 136
 137         if (rp == NULL) {
 138                 err_nonfatal("Socket failed: %m");
 139                 sock = -1;
 140                 goto err;
 141         }
 142
 143         setmysockopt(sock);
 144 err:
 145         freeaddrinfo(ai);
 146         return sock;
 147 }
 148
 149 int openunix(const char *path) {
 150         int sock;
 151         struct sockaddr_un un_addr;
 152         memset(&un_addr, 0, sizeof(un_addr));
 153
 154         un_addr.sun_family = AF_UNIX;
 155         if (strnlen(path, sizeof(un_addr.sun_path)) == sizeof(un_addr.sun_path)) {
 156                 err_nonfatal("UNIX socket path too long");
 157                 return -1;
 158         }
 159
 160         strncpy(un_addr.sun_path, path, sizeof(un_addr.sun_path) - 1);
 161
 162         if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
 163                 err_nonfatal("SOCKET failed");
 164                 return -1;
 165         };
 166
 167         if (connect(sock, &un_addr, sizeof(un_addr)) == -1) {
 168                 err_nonfatal("CONNECT failed");
 169                 close(sock);
 170                 return -1;
 171         }
 172         return sock;
 173 }
 174
 175 void ask_list(int sock) {
 176         uint32_t opt;
 177         uint32_t opt_server;
 178         uint32_t len;
 179         uint32_t reptype;
 180         uint64_t magic;
 181         int rlen;
 182         const int BUF_SIZE = 1024;
 183         char buf[BUF_SIZE];
 184
 185         magic = ntohll(opts_magic);
 186         if (write(sock, &magic, sizeof(magic)) < 0)
 187                 err("Failed/2.2: %m");
 188
 189         /* Ask for the list */
 190         opt = htonl(NBD_OPT_LIST);
 191         if(write(sock, &opt, sizeof(opt)) < 0) {
 192                 err("writing list option failed: %m");
 193         }
 194         /* Send the length (zero) */
 195         len = htonl(0);
 196         if(write(sock, &len, sizeof(len)) < 0) {
 197                 err("writing length failed: %m");
 198         }
 199         /* newline, move away from the "Negotiation:" line */
 200         printf("\n");
 201         do {
 202                 memset(buf, 0, 1024);
 203                 if(read(sock, &magic, sizeof(magic)) < 0) {
 204                         err("Reading magic from server: %m");
 205                 }
 206                 if(read(sock, &opt_server, sizeof(opt_server)) < 0) {
 207                         err("Reading option: %m");
 208                 }
 209                 if(read(sock, &reptype, sizeof(reptype)) <0) {
 210                         err("Reading reply from server: %m");
 211                 }
 212                 if(read(sock, &len, sizeof(len)) < 0) {
 213                         err("Reading length from server: %m");
 214                 }
 215                 magic=ntohll(magic);
 216                 len=ntohl(len);
 217                 reptype=ntohl(reptype);
 218                 if(magic != rep_magic) {
 219                         err("Not enough magic from server");
 220                 }
 221                 if(reptype & NBD_REP_FLAG_ERROR) {
 222                         switch(reptype) {
 223                                 case NBD_REP_ERR_POLICY:
 224                                         fprintf(stderr, "\nE: listing not allowed by server.\n");
 225                                         break;
 226                                 default:
 227                                         fprintf(stderr, "\nE: unexpected error from server.\n");
 228                                         break;
 229                         }
 230                         if(len > 0 && len < BUF_SIZE) {
 231                                 if((rlen=read(sock, buf, len)) < 0) {
 232                                         fprintf(stderr, "\nE: could not read error message from server\n");
 233                                 } else {
 234                                         buf[rlen] = '\0';
 235                                         fprintf(stderr, "Server said: %s\n", buf);
 236                                 }
 237                         }
 238                         exit(EXIT_FAILURE);
 239                 } else {
 240                         if(len) {
 241                                 if(reptype != NBD_REP_SERVER) {
 242                                         err("Server sent us a reply we don't understand!");
 243                                 }
 244                                 if(read(sock, &len, sizeof(len)) < 0) {
 245                                         fprintf(stderr, "\nE: could not read export name length from server\n");
 246                                         exit(EXIT_FAILURE);
 247                                 }
 248                                 len=ntohl(len);
 249                                 if (len >= BUF_SIZE) {
 250                                         fprintf(stderr, "\nE: export name on server too long\n");
 251                                         exit(EXIT_FAILURE);
 252                                 }
 253                                 if(read(sock, buf, len) < 0) {
 254                                         fprintf(stderr, "\nE: could not read export name from server\n");
 255                                         exit(EXIT_FAILURE);
 256                                 }
 257                                 buf[len] = 0;
 258                                 printf("%s\n", buf);
 259                         }
 260                 }
 261         } while(reptype != NBD_REP_ACK);
 262         opt=htonl(NBD_OPT_ABORT);
 263         len=htonl(0);
 264         magic=htonll(opts_magic);
 265         if (write(sock, &magic, sizeof(magic)) < 0)
 266                 err("Failed/2.2: %m");
 267         if (write(sock, &opt, sizeof(opt)) < 0)
 268                 err("Failed writing abort");
 269         if (write(sock, &len, sizeof(len)) < 0)
 270                 err("Failed writing length");
 271 }
 272
 273 void negotiate(int *sockp, u64 *rsize64, uint16_t *flags, char* name, uint32_t needed_flags, uint32_t client_flags, uint32_t do_opts, char *certfile, char *keyfile, char *cacertfile, char *tlshostname, bool tls) {
 274         u64 magic, size64;
 275         uint16_t tmp;
 276         uint16_t global_flags;
 277         char buf[256] = "\0\0\0\0\0\0\0\0\0";
 278         uint32_t opt;
 279         uint32_t namesize;
 280         int sock = *sockp;
 281
 282         printf("Negotiation: ");
 283         readit(sock, buf, 8);
 284         if (strcmp(buf, INIT_PASSWD))
 285                 err("INIT_PASSWD bad");
 286         printf(".");
 287         readit(sock, &magic, sizeof(magic));
 288         magic = ntohll(magic);
 289         if (magic != opts_magic) {
 290                 if(magic == cliserv_magic) {
 291                         err("It looks like you're trying to connect to an oldstyle server. This is no longer supported since nbd 3.10.");
 292                 }
 293         }
 294         printf(".");
 295         readit(sock, &tmp, sizeof(uint16_t));
 296         global_flags = ntohs(tmp);
 297         if((needed_flags & global_flags) != needed_flags) {
 298                 /* There's currently really only one reason why this
 299                  * check could possibly fail, but we may need to change
 300                  * this error message in the future... */
 301                 fprintf(stderr, "\nE: Server does not support listing exports\n");
 302                 exit(EXIT_FAILURE);
 303         }
 304
 305         if (global_flags & NBD_FLAG_NO_ZEROES) {
 306                 client_flags |= NBD_FLAG_C_NO_ZEROES;
 307         }
 308         client_flags = htonl(client_flags);
 309         if (write(sock, &client_flags, sizeof(client_flags)) < 0)
 310                 err("Failed/2.1: %m");
 311
 312 #if HAVE_GNUTLS
 313         /* TLS */
 314         if (tls) {
 315                 int plainfd[2]; // [0] is used by the proxy, [1] is used by NBD
 316                 tlssession_t *s = NULL;
 317                 int ret;
 318                 uint32_t tmp32;
 319                 uint64_t tmp64;
 320
 321                 /* magic */
 322                 tmp64 = htonll(opts_magic);
 323                 if (write(sock, &tmp64, sizeof(tmp64)) < 0)
 324                         err( "Could not write magic: %m");
 325                 /* starttls */
 326                 tmp32 = htonl(NBD_OPT_STARTTLS);
 327                 if (write(sock, &tmp32, sizeof(tmp32)) < 0)
 328                         err("Could not write option: %m");
 329                 /* length of data */
 330                 tmp32 = htonl(0);
 331                 if (write(sock, &tmp32, sizeof(tmp32)) < 0)
 332                         err("Could not write option length: %m");
 333
 334                 if (read(sock, &tmp64, sizeof(tmp64)) < 0)
 335                         err("Could not read cliserv_magic: %m");
 336                 tmp64 = ntohll(tmp64);
 337                 if (tmp64 != NBD_OPT_REPLY_MAGIC) {
 338                         err("reply magic does not match");
 339                 }
 340                 if (read(sock, &tmp32, sizeof(tmp32)) < 0)
 341                         err("Could not read option type: %m");
 342                 tmp32 = ntohl(tmp32);
 343                 if (tmp32 != NBD_OPT_STARTTLS)
 344                         err("Reply to wrong option");
 345                 if (read(sock, &tmp32, sizeof(tmp32)) < 0)
 346                         err("Could not read option reply type: %m");
 347                 tmp32 = ntohl(tmp32);
 348                 if (tmp32 != NBD_REP_ACK) {
 349                         err("Option reply type != NBD_REP_ACK");
 350                 }
 351                 if (read(sock, &tmp32, sizeof(tmp32)) < 0) err(
 352                         "Could not read option data length: %m");
 353                 tmp32 = ntohl(tmp32);
 354                 if (tmp32 != 0) {
 355                         err("Option reply data length != 0");
 356                 }
 357                 s = tlssession_new(0,
 358                                    keyfile,
 359                                    certfile,
 360                                    cacertfile,
 361                                    tlshostname,
 362                                    !cacertfile || !tlshostname, // insecure flag
 363 #ifdef DODBG
 364                                    1, // debug
 365 #else
 366                                    0, // debug
 367 #endif
 368                                    NULL, // quitfn
 369                                    NULL, // erroutfn
 370                                    NULL // opaque
 371                         );
 372                 if (!s)
 373                         err("Cannot establish TLS session");
 374
 375                 if (socketpair(AF_UNIX, SOCK_STREAM, 0, plainfd) < 0)
 376                         err("Cannot get socket pair");
 377
 378                 if (set_nonblocking(plainfd[0], 0) <0 ||
 379                     set_nonblocking(plainfd[1], 0) <0 ||
 380                     set_nonblocking(sock, 0) <0) {
 381                         close(plainfd[0]);
 382                         close(plainfd[1]);
 383                         err("Cannot set socket options");
 384                 }
 385
 386                 ret = fork();
 387                 if (ret < 0)
 388                         err("Could not fork");
 389                 else if (ret == 0) {
 390                         // we are the child
 391                         if (daemon(0, 0) < 0) {
 392                                 /* no one will see this */
 393                                 fprintf(stderr, "Can't detach from the terminal");
 394                                 exit(1);
 395                         }
 396                         signal (SIGPIPE, SIG_IGN);
 397                         close(plainfd[1]);
 398                         tlssession_mainloop(sock, plainfd[0], s);
 399                         close(sock);
 400                         close(plainfd[0]);
 401                         exit(0);
 402                 }
 403                 close(plainfd[0]);
 404                 close(sock);
 405                 sock = plainfd[1]; /* use the decrypted FD from now on */
 406                 *sockp = sock;
 407         }
 408 #else
 409         if (keyfile) {
 410                 err("TLS requested but support not compiled in");
 411         }
 412 #endif
 413
 414         if(do_opts & NBDC_DO_LIST) {
 415                 ask_list(sock);
 416                 exit(EXIT_SUCCESS);
 417         }
 418
 419         /* Write the export name that we're after */
 420         magic = htonll(opts_magic);
 421         if (write(sock, &magic, sizeof(magic)) < 0)
 422                 err("Failed/2.2: %m");
 423
 424         opt = ntohl(NBD_OPT_EXPORT_NAME);
 425         if (write(sock, &opt, sizeof(opt)) < 0)
 426                 err("Failed/2.3: %m");
 427         namesize = (u32)strlen(name);
 428         namesize = ntohl(namesize);
 429         if (write(sock, &namesize, sizeof(namesize)) < 0)
 430                 err("Failed/2.4: %m");
 431         if (write(sock, name, strlen(name)) < 0)
 432                 err("Failed/2.4: %m");
 433
 434         readit(sock, &size64, sizeof(size64));
 435         size64 = ntohll(size64);
 436
 437         if ((size64>>12) > (uint64_t)~0UL) {
 438                 printf("size = %luMB", (unsigned long)(size64>>20));
 439                 err("Exported device is too big for me. Get 64-bit machine :-(\n");
 440         } else
 441                 printf("size = %luMB", (unsigned long)(size64>>20));
 442
 443         readit(sock, &tmp, sizeof(tmp));
 444         *flags = (uint32_t)ntohs(tmp);
 445
 446         if (!(global_flags & NBD_FLAG_NO_ZEROES)) {
 447                 readit(sock, &buf, 124);
 448         }
 449         printf("\n");
 450
 451         *rsize64 = size64;
 452 }
 453
 454 bool get_from_config(char* cfgname, char** name_ptr, char** dev_ptr, char** hostn_ptr, int* bs, int* timeout, int* persist, int* swap, int* sdp, int* b_unix, char**port, int* num_conns, char **certfile, char **keyfile, char **cacertfile, char **tlshostname) {
 455         int fd = open(SYSCONFDIR "/nbdtab", O_RDONLY);
 456         bool retval = false;
 457         if(fd < 0) {
 458                 fprintf(stderr, "while opening %s: ", SYSCONFDIR "/nbdtab");
 459                 perror("could not open config file");
 460                 goto out;
 461         }
 462         off_t size = lseek(fd, 0, SEEK_END);
 463         lseek(fd, 0, SEEK_SET);
 464         void *data = NULL;
 465         char *fsep = "\n\t# ";
 466         char *lsep = "\n#";
 467
 468         if(size < 0) {
 469                 perror("E: mmap'ing nbdtab");
 470                 exit(EXIT_FAILURE);
 471         }
 472
 473         data = mmap(NULL, (size_t)size, PROT_READ, MAP_SHARED, fd, 0);
 474         if(!strncmp(cfgname, "/dev/", 5)) {
 475                 cfgname += 5;
 476         }
 477         char *loc = strstr((const char*)data, cfgname);
 478         if(!loc) {
 479                 goto out;
 480         }
 481         size_t l = strlen(cfgname) + 6;
 482         *dev_ptr = malloc(l);
 483         snprintf(*dev_ptr, l, "/dev/%s", cfgname);
 484
 485         size_t line_len, field_len, ws_len;
 486 #define CHECK_LEN field_len = strcspn(loc, fsep); ws_len = strspn(loc+field_len, fsep); if(field_len > line_len || line_len <= 0) { goto out; }
 487 #define MOVE_NEXT line_len -= field_len + ws_len; loc += field_len + ws_len
 488         // find length of line
 489         line_len = strcspn(loc, lsep);
 490         // first field is the device node name, which we already know, so skip it
 491         CHECK_LEN;
 492         MOVE_NEXT;
 493         // next field is the hostname
 494         CHECK_LEN;
 495         *hostn_ptr = strndup(loc, field_len);
 496         MOVE_NEXT;
 497         // third field is the export name
 498         CHECK_LEN;
 499         *name_ptr = strndup(loc, field_len);
 500         if(ws_len + field_len > line_len) {
 501                 // optional last field is not there, so return success
 502                 retval = true;
 503                 goto out;
 504         }
 505         MOVE_NEXT;
 506         CHECK_LEN;
 507 #undef CHECK_LEN
 508 #undef MOVE_NEXT
 509         // fourth field is the options field, a comma-separated field of options
 510         do {
 511                 if(!strncmp(loc, "conns=", 6)) {
 512                         *num_conns = (int)strtol(loc+6, &loc, 0);
 513                         goto next;
 514                 }
 515                 if(!strncmp(loc, "bs=", 3)) {
 516                         *bs = (int)strtol(loc+3, &loc, 0);
 517                         goto next;
 518                 }
 519                 if(!strncmp(loc, "timeout=", 8)) {
 520                         *timeout = (int)strtol(loc+8, &loc, 0);
 521                         goto next;
 522                 }
 523                 if(!strncmp(loc, "port=", 5)) {
 524                         *port = strndup(loc+5, strcspn(loc+5, ","));
 525                         goto next;
 526                 }
 527                 if(!strncmp(loc, "persist", 7)) {
 528                         loc += 7;
 529                         *persist = 1;
 530                         goto next;
 531                 }
 532                 if(!strncmp(loc, "swap", 4)) {
 533                         *swap = 1;
 534                         loc += 4;
 535                         goto next;
 536                 }
 537                 if(!strncmp(loc, "sdp", 3)) {
 538                         *sdp = 1;
 539                         loc += 3;
 540                         goto next;
 541                 }
 542                 if(!strncmp(loc, "unix", 4)) {
 543                         *b_unix = 1;
 544                         loc += 4;
 545                         goto next;
 546                 }
 547                 if(!strncmp(loc, "certfile=", 9)) {
 548                         *certfile = strndup(loc+9, strcspn(loc+9, ","));
 549                         goto next;
 550                 }
 551                 if(!strncmp(loc, "keyfile=", 8)) {
 552                         *keyfile = strndup(loc+8, strcspn(loc+8, ","));
 553                         goto next;
 554                 }
 555                 if(!strncmp(loc, "cacertfile=", 11)) {
 556                         *cacertfile = strndup(loc+11, strcspn(loc+11, ","));
 557                         goto next;
 558                 }
 559                 if(!strncmp(loc, "tlshostname=", 9)) {
 560                         *tlshostname = strndup(loc+9, strcspn(loc+9, ","));
 561                         goto next;
 562                 }
 563                 // skip unknown options, with a warning unless they start with a '_'
 564                 l = strcspn(loc, ",");
 565                 if(*loc != '_') {
 566                         char* s = strndup(loc, l);
 567                         fprintf(stderr, "Warning: unknown option '%s' found in nbdtab file", s);
 568                         free(s);
 569                 }
 570                 loc += l;
 571 next:
 572                 if(*loc == ',') {
 573                         loc++;
 574                 }
 575         } while(strcspn(loc, lsep) > 0);
 576         retval = true;
 577 out:
 578         if(data != NULL) {
 579                 munmap(data, size);
 580         }
 581         if(fd >= 0) {
 582                 close(fd);
 583         }
 584         return retval;
 585 }
 586
 587 void setsizes(int nbd, u64 size64, int blocksize, u32 flags) {
 588         unsigned long size;
 589         int read_only = (flags & NBD_FLAG_READ_ONLY) ? 1 : 0;
 590
 591         if (size64>>12 > (uint64_t)~0UL)
 592                 err("Device too large.\n");
 593         else {
 594                 int tmp_blocksize = 4096;
 595                 if (size64 / (u64)blocksize <= (uint64_t)~0UL)
 596                         tmp_blocksize = blocksize;
 597                 if (ioctl(nbd, NBD_SET_BLKSIZE, tmp_blocksize) < 0) {
 598                         fprintf(stderr, "Failed to set blocksize %d\n",
 599                                 tmp_blocksize);
 600                         err("Ioctl/1.1a failed: %m\n");
 601                 }
 602                 size = (unsigned long)(size64 / (u64)tmp_blocksize);
 603                 if (ioctl(nbd, NBD_SET_SIZE_BLOCKS, size) < 0)
 604                         err("Ioctl/1.1b failed: %m\n");
 605                 if (tmp_blocksize != blocksize) {
 606                         if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0) {
 607                                 fprintf(stderr, "Failed to set blocksize %d\n",
 608                                         blocksize);
 609                                 err("Ioctl/1.1c failed: %m\n");
 610                         }
 611                 }
 612                 fprintf(stderr, "bs=%d, sz=%llu bytes\n", blocksize, (u64)tmp_blocksize * size);
 613         }
 614
 615         ioctl(nbd, NBD_CLEAR_SOCK);
 616
 617         /* ignore error as kernel may not support */
 618         ioctl(nbd, NBD_SET_FLAGS, (unsigned long) flags);
 619
 620         if (ioctl(nbd, BLKROSET, (unsigned long) &read_only) < 0)
 621                 err("Unable to set read-only attribute for device");
 622 }
 623
 624 void set_timeout(int nbd, int timeout) {
 625         if (timeout) {
 626                 if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)timeout) < 0)
 627                         err("Ioctl NBD_SET_TIMEOUT failed: %m\n");
 628                 fprintf(stderr, "timeout=%d\n", timeout);
 629         }
 630 }
 631
 632 void finish_sock(int sock, int nbd, int swap) {
 633         if (ioctl(nbd, NBD_SET_SOCK, sock) < 0) {
 634                 if (errno == EBUSY)
 635                         err("Kernel doesn't support multiple connections\n");
 636                 else
 637                         err("Ioctl NBD_SET_SOCK failed: %m\n");
 638         }
 639
 640 #ifndef __ANDROID__
 641         if (swap)
 642                 mlockall(MCL_CURRENT | MCL_FUTURE);
 643 #endif
 644 }
 645
 646 static int
 647 oom_adjust(const char *file, const char *value)
 648 {
 649         int fd, rc;
 650         size_t len;
 651
 652         fd = open(file, O_WRONLY);
 653         if (fd < 0)
 654                 return -1;
 655         len = strlen(value);
 656         rc = write(fd, value, len) != (ssize_t) len;
 657         close(fd);
 658         return rc ? -1 : 0;
 659 }
 660
 661 void usage(char* errmsg, ...) {
 662         if(errmsg) {
 663                 char tmp[256];
 664                 va_list ap;
 665                 va_start(ap, errmsg);
 666                 snprintf(tmp, 256, "ERROR: %s\n\n", errmsg);
 667                 vfprintf(stderr, tmp, ap);
 668                 va_end(ap);
 669         } else {
 670                 fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION);
 671         }
 672         fprintf(stderr, "Usage: nbd-client -name|-N name host [port] nbd_device\n\t[-block-size|-b block size] [-timeout|-t timeout] [-swap|-s] [-sdp|-S]\n\t[-persist|-p] [-nofork|-n] [-systemd-mark|-m]\n");
 673         fprintf(stderr, "Or   : nbd-client -u (with same arguments as above)\n");
 674         fprintf(stderr, "Or   : nbd-client nbdX\n");
 675         fprintf(stderr, "Or   : nbd-client -d nbd_device\n");
 676         fprintf(stderr, "Or   : nbd-client -c nbd_device\n");
 677         fprintf(stderr, "Or   : nbd-client -h|--help\n");
 678         fprintf(stderr, "Or   : nbd-client -l|--list host\n");
 679 #if HAVE_GNUTLS
 680         fprintf(stderr, "All commands that connect to a host also take:\n\t[-F|-certfile certfile] [-K|-keyfile keyfile]\n\t[-A|-cacertfile cacertfile] [-H|-tlshostname hostname] [-x|-enable-tls]\n");
 681 #endif
 682         fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n");
 683         fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
 684         fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
 685         fprintf(stderr, "blocksizes other than 1024 without patches\n");
 686         fprintf(stderr, "Default value for port is 10809. Note that port must always be numeric\n");
 687 }
 688
 689 void disconnect(char* device) {
 690         int nbd = open(device, O_RDWR);
 691
 692         if (nbd < 0)
 693                 err("Cannot open NBD: %m\nPlease ensure the 'nbd' module is loaded.");
 694         printf("disconnect, ");
 695         if (ioctl(nbd, NBD_DISCONNECT)<0)
 696                 err("Ioctl failed: %m\n");
 697         printf("sock, ");
 698         if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
 699                 err("Ioctl failed: %m\n");
 700         printf("done\n");
 701 }
 702
 703 int main(int argc, char *argv[]) {
 704         char* port=NBD_DEFAULT_PORT;
 705         int sock, nbd;
 706         int blocksize=1024;
 707         char *hostname=NULL;
 708         char *nbddev=NULL;
 709         int swap=0;
 710         int cont=0;
 711         int timeout=0;
 712         int sdp=0;
 713         int G_GNUC_UNUSED nofork=0; // if -dNOFORK
 714         pid_t main_pid;
 715         u64 size64;
 716         uint16_t flags = 0;
 717         int c;
 718         int nonspecial=0;
 719         int b_unix=0;
 720         char* name="";
 721         uint16_t needed_flags=0;
 722         uint32_t cflags=NBD_FLAG_C_FIXED_NEWSTYLE;
 723         uint32_t opts=0;
 724         sigset_t block, old;
 725         char *certfile = NULL;
 726         char *keyfile = NULL;
 727         char *cacertfile = NULL;
 728         char *tlshostname = NULL;
 729         bool tls = false;
 730         struct sigaction sa;
 731         int num_connections = 1;
 732         struct option long_options[] = {
 733                 { "block-size", required_argument, NULL, 'b' },
 734                 { "check", required_argument, NULL, 'c' },
 735                 { "connections", required_argument, NULL, 'C'},
 736                 { "disconnect", required_argument, NULL, 'd' },
 737                 { "help", no_argument, NULL, 'h' },
 738                 { "list", no_argument, NULL, 'l' },
 739                 { "name", required_argument, NULL, 'N' },
 740                 { "nofork", no_argument, NULL, 'n' },
 741                 { "persist", no_argument, NULL, 'p' },
 742                 { "sdp", no_argument, NULL, 'S' },
 743                 { "swap", no_argument, NULL, 's' },
 744                 { "systemd-mark", no_argument, NULL, 'm' },
 745                 { "timeout", required_argument, NULL, 't' },
 746                 { "unix", no_argument, NULL, 'u' },
 747                 { "certfile", required_argument, NULL, 'F' },
 748                 { "keyfile", required_argument, NULL, 'K' },
 749                 { "cacertfile", required_argument, NULL, 'A' },
 750                 { "tlshostname", required_argument, NULL, 'H' },
 751                 { "enable-tls", no_argument, NULL, 'x' },
 752                 { 0, 0, 0, 0 },
 753         };
 754         int i;
 755
 756         logging(MY_NAME);
 757
 758 #if HAVE_GNUTLS
 759         tlssession_init();
 760 #endif
 761
 762         while((c=getopt_long_only(argc, argv, "-b:c:d:hlnN:pSst:uC:K:A:H:x", long_options, NULL))>=0) {
 763                 switch(c) {
 764                 case 1:
 765                         // non-option argument
 766                         if(strchr(optarg, '=')) {
 767                                 // old-style 'bs=' or 'timeout='
 768                                 // argument
 769                                 fprintf(stderr, "WARNING: old-style command-line argument encountered. This is deprecated.\n");
 770                                 if(!strncmp(optarg, "bs=", 3)) {
 771                                         optarg+=3;
 772                                         goto blocksize;
 773                                 }
 774                                 if(!strncmp(optarg, "timeout=", 8)) {
 775                                         optarg+=8;
 776                                         goto timeout;
 777                                 }
 778                                 usage("unknown option %s encountered", optarg);
 779                                 exit(EXIT_FAILURE);
 780                         }
 781                         switch(nonspecial++) {
 782                                 case 0:
 783                                         // host
 784                                         hostname=optarg;
 785                                         break;
 786                                 case 1:
 787                                         // port
 788                                         if(!strtol(optarg, NULL, 0)) {
 789                                                 // not parseable as a number, assume it's the device
 790                                                 nbddev = optarg;
 791                                                 nonspecial++;
 792                                         } else {
 793                                                 port = optarg;
 794                                         }
 795                                         break;
 796                                 case 2:
 797                                         // device
 798                                         nbddev = optarg;
 799                                         break;
 800                                 default:
 801                                         usage("too many non-option arguments specified");
 802                                         exit(EXIT_FAILURE);
 803                         }
 804                         break;
 805                 case 'b':
 806                       blocksize:
 807                         blocksize=(int)strtol(optarg, NULL, 0);
 808                         break;
 809                 case 'c':
 810                         return check_conn(optarg, 1);
 811                 case 'C':
 812                         num_connections = (int)strtol(optarg, NULL, 0);
 813                         break;
 814                 case 'd':
 815                         disconnect(optarg);
 816                         exit(EXIT_SUCCESS);
 817                 case 'h':
 818                         usage(NULL);
 819                         exit(EXIT_SUCCESS);
 820                 case 'l':
 821                         needed_flags |= NBD_FLAG_FIXED_NEWSTYLE;
 822                         opts |= NBDC_DO_LIST;
 823                         nbddev="";
 824                         break;
 825                 case 'm':
 826                         argv[0][0] = '@';
 827                         break;
 828                 case 'n':
 829                         nofork=1;
 830                         break;
 831                 case 'N':
 832                         name=optarg;
 833                         break;
 834                 case 'p':
 835                         cont=1;
 836                         break;
 837                 case 's':
 838                         swap=1;
 839                         break;
 840                 case 'S':
 841                         sdp=1;
 842                         break;
 843                 case 't':
 844                       timeout:
 845                         timeout=strtol(optarg, NULL, 0);
 846                         break;
 847                 case 'u':
 848                         b_unix = 1;
 849                         break;
 850 #if HAVE_GNUTLS
 851                 case 'x':
 852                         tls = true;
 853                         break;
 854                 case 'F':
 855                         certfile=strdup(optarg);
 856                         break;
 857                 case 'K':
 858                         keyfile=strdup(optarg);
 859                         break;
 860                 case 'A':
 861                         cacertfile=strdup(optarg);
 862                         break;
 863                 case 'H':
 864                         tlshostname=strdup(optarg);
 865                         break;
 866 #else
 867                 case 'F':
 868                 case 'K':
 869                 case 'H':
 870                 case 'A':
 871                         fprintf(stderr, "E: TLS support not compiled in\n");
 872                         exit(EXIT_FAILURE);
 873 #endif
 874                 default:
 875                         fprintf(stderr, "E: option eaten by 42 mice\n");
 876                         exit(EXIT_FAILURE);
 877                 }
 878         }
 879
 880 #ifdef __ANDROID__
 881   if (swap)
 882     err("swap option unsupported on Android because mlockall is unsupported.");
 883 #endif
 884         if(hostname) {
 885                 if((!name || !nbddev) && !(opts & NBDC_DO_LIST)) {
 886                         if(!strncmp(hostname, "nbd", 3) || !strncmp(hostname, "/dev/nbd", 8)) {
 887                                 if(!get_from_config(hostname, &name, &nbddev, &hostname, &blocksize, &timeout, &cont, &swap, &sdp, &b_unix, &port, &num_connections, &certfile, &keyfile, &cacertfile, &hostname)) {
 888                                         usage("no valid configuration for specified device found", hostname);
 889                                         exit(EXIT_FAILURE);
 890                                 }
 891                         } else {
 892                                 usage("not enough information specified, and argument didn't look like an nbd device");
 893                                 exit(EXIT_FAILURE);
 894                         }
 895                 }
 896         } else {
 897                 usage("no information specified");
 898                 exit(EXIT_FAILURE);
 899         }
 900
 901         if (keyfile && !certfile)
 902                 certfile = strdup(keyfile);
 903
 904         if (certfile != NULL || keyfile != NULL || cacertfile != NULL || tlshostname != NULL) {
 905                 tls = true;
 906         }
 907
 908         if (!tlshostname && hostname)
 909                 tlshostname = strdup(hostname);
 910
 911         if(strlen(name)==0 && !(opts & NBDC_DO_LIST)) {
 912                 printf("Warning: the oldstyle protocol is no longer supported.\nThis method now uses the newstyle protocol with a default export\n");
 913         }
 914
 915         if(!opts & NBDC_DO_LIST) {
 916                 nbd = open(nbddev, O_RDWR);
 917                 if (nbd < 0)
 918                         err("Cannot open NBD: %m\nPlease ensure the 'nbd' module is loaded.");
 919         }
 920
 921         for (i = 0; i < num_connections; i++) {
 922                 if (b_unix)
 923                         sock = openunix(hostname);
 924                 else
 925                         sock = opennet(hostname, port, sdp);
 926                 if (sock < 0)
 927                         exit(EXIT_FAILURE);
 928
 929                 negotiate(&sock, &size64, &flags, name, needed_flags, cflags, opts, certfile, keyfile, cacertfile, tlshostname, tls);
 930                 if (i == 0) {
 931                         setsizes(nbd, size64, blocksize, flags);
 932                         set_timeout(nbd, timeout);
 933                 }
 934                 finish_sock(sock, nbd, swap);
 935                 if (swap) {
 936                         if (keyfile)
 937                                 fprintf(stderr, "Warning: using swap and TLS is prone to deadlock\n");
 938                         /* try linux >= 2.6.36 interface first */
 939                         if (oom_adjust("/proc/self/oom_score_adj", "-1000")) {
 940                                 /* fall back to linux <= 2.6.35 interface */
 941                                 oom_adjust("/proc/self/oom_adj", "-17");
 942                         }
 943                 }
 944         }
 945
 946         /* Go daemon */
 947
 948 #ifndef NOFORK
 949         if(!nofork) {
 950                 if (daemon(0,0) < 0)
 951                         err("Cannot detach from terminal");
 952         }
 953
 954         memset(&sa, 0, sizeof(sa));
 955         sa.sa_handler = SIG_IGN;
 956         sigaction(SIGCHLD, &sa, NULL);
 957 #endif
 958         /* For child to check its parent */
 959         main_pid = getpid();
 960         do {
 961 #ifndef NOFORK
 962
 963                 sigfillset(&block);
 964                 sigdelset(&block, SIGKILL);
 965                 sigdelset(&block, SIGTERM);
 966                 sigdelset(&block, SIGPIPE);
 967                 sigprocmask(SIG_SETMASK, &block, &old);
 968
 969                 if (!fork()) {
 970                         /* Due to a race, the kernel NBD driver cannot
 971                          * call for a reread of the partition table
 972                          * in the handling of the NBD_DO_IT ioctl().
 973                          * Therefore, this is done in the first open()
 974                          * of the device. We therefore make sure that
 975                          * the device is opened at least once after the
 976                          * connection was made. This has to be done in a
 977                          * separate process, since the NBD_DO_IT ioctl()
 978                          * does not return until the NBD device has
 979                          * disconnected.
 980                          */
 981                         struct timespec req = {
 982                                 .tv_sec = 0,
 983                                 .tv_nsec = 100000000,
 984                         };
 985                         while(check_conn(nbddev, 0)) {
 986                                 if (main_pid != getppid()) {
 987                                         /* check_conn() will not return 0 when nbd disconnected
 988                                          * and parent exited during this loop. So the child has to
 989                                          * explicitly check parent identity and exit if parent
 990                                          * exited */
 991                                         exit(0);
 992                                 }
 993                                 nanosleep(&req, NULL);
 994                         }
 995                         open(nbddev, O_RDONLY);
 996                         exit(0);
 997                 }
 998 #endif
 999
1000                 if (ioctl(nbd, NBD_DO_IT) < 0) {
1001                         int error = errno;
1002                         fprintf(stderr, "nbd,%d: Kernel call returned: %d", main_pid, error);
1003                         if(error==EBADR) {
1004                                 /* The user probably did 'nbd-client -d' on us.
1005                                  * quit */
1006                                 cont=0;
1007                         } else {
1008                                 if(cont) {
1009                                         u64 new_size;
1010                                         uint16_t new_flags;
1011
1012                                         close(sock); close(nbd);
1013                                         for (;;) {
1014                                                 fprintf(stderr, " Reconnecting\n");
1015                                                 if (b_unix)
1016                                                         sock = openunix(hostname);
1017                                                 else
1018                                                         sock = opennet(hostname, port, sdp);
1019                                                 if (sock >= 0)
1020                                                         break;
1021                                                 sleep (1);
1022                                         }
1023                                         nbd = open(nbddev, O_RDWR);
1024                                         if (nbd < 0)
1025                                                 err("Cannot open NBD: %m");
1026                                         negotiate(&sock, &new_size, &new_flags, name, needed_flags, cflags, opts, certfile, keyfile, cacertfile, tlshostname, tls);
1027                                         if (size64 != new_size) {
1028                                                 err("Size of the device changed. Bye");
1029                                         }
1030                                         setsizes(nbd, size64, blocksize,
1031                                                                 new_flags);
1032
1033                                         set_timeout(nbd, timeout);
1034                                         finish_sock(sock,nbd,swap);
1035                                 }
1036                         }
1037                 } else {
1038                         /* We're on 2.4. It's not clearly defined what exactly
1039                          * happened at this point. Probably best to quit, now
1040                          */
1041                         fprintf(stderr, "Kernel call returned.");
1042                         cont=0;
1043                 }
1044         } while(cont);
1045         printf("sock, ");
1046         ioctl(nbd, NBD_CLEAR_SOCK);
1047         printf("done\n");
1048         return 0;
1049 }