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 <inttypes.h>
  34 #include <stdio.h>
  35 #include <fcntl.h>
  36 #include <syslog.h>
  37 #include <stdlib.h>
  38 #include <sys/mount.h>
  39 #include <sys/mman.h>
  40 #include <signal.h>
  41 #include <errno.h>
  42 #include <getopt.h>
  43 #include <stdarg.h>
  44 #include <stdbool.h>
  45 #include <time.h>
  46
  47 #include <linux/ioctl.h>
  48 #define MY_NAME "nbd_client"
  49 #include "cliserv.h"
  50
  51 #if HAVE_GNUTLS && !defined(NOTLS)
  52 #include "crypto-gnutls.h"
  53 #endif
  54
  55 #ifdef WITH_SDP
  56 #include <sdp_inet.h>
  57 #endif
  58
  59 #define NBDC_DO_LIST 1
  60
  61 int check_conn(char* devname, int do_print) {
  62         char buf[256];
  63         char* p;
  64         int fd;
  65         int len;
  66
  67         if( (p=strrchr(devname, '/')) ) {
  68                 devname=p+1;
  69         }
  70         if((p=strchr(devname, 'p'))) {
  71                 /* We can't do checks on partitions. */
  72                 *p='\0';
  73         }
  74         snprintf(buf, 256, "/sys/block/%s/pid", devname);
  75         if((fd=open(buf, O_RDONLY))<0) {
  76                 if(errno==ENOENT) {
  77                         return 1;
  78                 } else {
  79                         return 2;
  80                 }
  81         }
  82         len=read(fd, buf, 256);
  83         if(len < 0) {
  84                 perror("could not read from server");
  85                 close(fd);
  86                 return 2;
  87         }
  88         buf[(len < 256) ? len : 255]='\0';
  89         if(do_print) printf("%s\n", buf);
  90         close(fd);
  91         return 0;
  92 }
  93
  94 int opennet(char *name, char* portstr, int sdp) {
  95         int sock;
  96         struct addrinfo hints;
  97         struct addrinfo *ai = NULL;
  98         struct addrinfo *rp = NULL;
  99         int e;
 100
 101         memset(&hints,'\0',sizeof(hints));
 102         hints.ai_family = AF_UNSPEC;
 103         hints.ai_socktype = SOCK_STREAM;
 104         hints.ai_flags = AI_ADDRCONFIG | AI_NUMERICSERV;
 105         hints.ai_protocol = IPPROTO_TCP;
 106
 107         e = getaddrinfo(name, portstr, &hints, &ai);
 108
 109         if(e != 0) {
 110                 fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
 111                 freeaddrinfo(ai);
 112                 return -1;
 113         }
 114
 115         if(sdp) {
 116 #ifdef WITH_SDP
 117                 if (ai->ai_family == AF_INET)
 118                         ai->ai_family = AF_INET_SDP;
 119                 else (ai->ai_family == AF_INET6)
 120                         ai->ai_family = AF_INET6_SDP;
 121 #else
 122                 err("Can't do SDP: I was not compiled with SDP support!");
 123 #endif
 124         }
 125
 126         for(rp = ai; rp != NULL; rp = rp->ai_next) {
 127                 sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 128
 129                 if(sock == -1)
 130                         continue;       /* error */
 131
 132                 if(connect(sock, rp->ai_addr, rp->ai_addrlen) != -1)
 133                         break;          /* success */
 134
 135                 close(sock);
 136         }
 137
 138         if (rp == NULL) {
 139                 err_nonfatal("Socket failed: %m");
 140                 sock = -1;
 141                 goto err;
 142         }
 143
 144         setmysockopt(sock);
 145 err:
 146         freeaddrinfo(ai);
 147         return sock;
 148 }
 149
 150 int openunix(const char *path) {
 151         int sock;
 152         struct sockaddr_un un_addr;
 153         memset(&un_addr, 0, sizeof(un_addr));
 154
 155         un_addr.sun_family = AF_UNIX;
 156         if (strnlen(path, sizeof(un_addr.sun_path)) == sizeof(un_addr.sun_path)) {
 157                 err_nonfatal("UNIX socket path too long");
 158                 return -1;
 159         }
 160
 161         strncpy(un_addr.sun_path, path, sizeof(un_addr.sun_path) - 1);
 162
 163         if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
 164                 err_nonfatal("SOCKET failed");
 165                 return -1;
 166         };
 167
 168         if (connect(sock, &un_addr, sizeof(un_addr)) == -1) {
 169                 err_nonfatal("CONNECT failed");
 170                 close(sock);
 171                 return -1;
 172         }
 173         return sock;
 174 }
 175
 176 void send_request(int sock, uint32_t opt, ssize_t datasize, void* data) {
 177         struct {
 178                 uint64_t magic;
 179                 uint32_t opt;
 180                 uint32_t datasize;
 181         } __attribute__((packed)) header = {
 182                 ntohll(opts_magic),
 183                 ntohl(opt),
 184                 ntohl(datasize),
 185         };
 186         if(datasize < 0) {
 187                 datasize = strlen((char*)data);
 188                 header.datasize = htonl(datasize);
 189         }
 190         writeit(sock, &header, sizeof(header));
 191         if(data != NULL) {
 192                 writeit(sock, data, datasize);
 193         }
 194 }
 195
 196 void send_info_request(int sock, uint32_t opt, int n_reqs, uint16_t* reqs, char* name) {
 197         uint16_t rlen = htons(n_reqs);
 198         uint32_t nlen = htonl(strlen(name));
 199
 200         send_request(sock, opt, sizeof(uint32_t) + strlen(name) + sizeof(uint16_t) + n_reqs * sizeof(uint16_t), NULL);
 201         writeit(sock, &nlen, sizeof(nlen));
 202         writeit(sock, name, strlen(name));
 203         writeit(sock, &rlen, sizeof(rlen));
 204         if(n_reqs > 0) {
 205                 writeit(sock, reqs, n_reqs * sizeof(uint16_t));
 206         }
 207 }
 208
 209 struct reply {
 210         uint64_t magic;
 211         uint32_t opt;
 212         uint32_t reply_type;
 213         uint32_t datasize;
 214         char data[];
 215 } __attribute__((packed));
 216
 217 struct reply* read_reply(int sock) {
 218         struct reply *retval = malloc(sizeof(struct reply));
 219         readit(sock, retval, sizeof(*retval));
 220         retval->magic = ntohll(retval->magic);
 221         retval->opt = ntohl(retval->opt);
 222         retval->reply_type = ntohl(retval->reply_type);
 223         retval->datasize = ntohl(retval->datasize);
 224         if (retval->magic != rep_magic) {
 225                 fprintf(stderr, "E: received invalid negotiation magic %" PRIu64 " (expected %" PRIu64 ")", retval->magic, rep_magic);
 226                 exit(EXIT_FAILURE);
 227         }
 228         if (retval->datasize > 0) {
 229                 retval = realloc(retval, sizeof(struct reply) + retval->datasize);
 230                 readit(sock, &(retval->data), retval->datasize);
 231         }
 232         return retval;
 233 }
 234
 235 void ask_list(int sock) {
 236         uint32_t opt;
 237         uint32_t opt_server;
 238         uint32_t len;
 239         uint32_t lenn;
 240         uint32_t reptype;
 241         uint64_t magic;
 242         int rlen;
 243         const int BUF_SIZE = 1024;
 244         char buf[BUF_SIZE];
 245
 246         send_request(sock, NBD_OPT_LIST, 0, NULL);
 247         /* newline, move away from the "Negotiation:" line */
 248         printf("\n");
 249         do {
 250                 memset(buf, 0, 1024);
 251                 if(read(sock, &magic, sizeof(magic)) < 0) {
 252                         err("Reading magic from server: %m");
 253                 }
 254                 if(read(sock, &opt_server, sizeof(opt_server)) < 0) {
 255                         err("Reading option: %m");
 256                 }
 257                 if(read(sock, &reptype, sizeof(reptype)) <0) {
 258                         err("Reading reply from server: %m");
 259                 }
 260                 if(read(sock, &len, sizeof(len)) < 0) {
 261                         err("Reading length from server: %m");
 262                 }
 263                 magic=ntohll(magic);
 264                 len=ntohl(len);
 265                 reptype=ntohl(reptype);
 266                 if(magic != rep_magic) {
 267                         err("Not enough magic from server");
 268                 }
 269                 if(reptype & NBD_REP_FLAG_ERROR) {
 270                         switch(reptype) {
 271                                 case NBD_REP_ERR_POLICY:
 272                                         fprintf(stderr, "\nE: listing not allowed by server.\n");
 273                                         break;
 274                                 default:
 275                                         fprintf(stderr, "\nE: unexpected error from server.\n");
 276                                         break;
 277                         }
 278                         if(len > 0 && len < BUF_SIZE) {
 279                                 if((rlen=read(sock, buf, len)) < 0) {
 280                                         fprintf(stderr, "\nE: could not read error message from server\n");
 281                                 } else {
 282                                         buf[rlen] = '\0';
 283                                         fprintf(stderr, "Server said: %s\n", buf);
 284                                 }
 285                         }
 286                         exit(EXIT_FAILURE);
 287                 } else {
 288                         if(reptype != NBD_REP_ACK) {
 289                                 if(reptype != NBD_REP_SERVER) {
 290                                         err("Server sent us a reply we don't understand!");
 291                                 }
 292                                 if(read(sock, &lenn, sizeof(lenn)) < 0) {
 293                                         fprintf(stderr, "\nE: could not read export name length from server\n");
 294                                         exit(EXIT_FAILURE);
 295                                 }
 296                                 lenn=ntohl(lenn);
 297                                 if (lenn >= BUF_SIZE) {
 298                                         fprintf(stderr, "\nE: export name on server too long\n");
 299                                         exit(EXIT_FAILURE);
 300                                 }
 301                                 if(read(sock, buf, lenn) < 0) {
 302                                         fprintf(stderr, "\nE: could not read export name from server\n");
 303                                         exit(EXIT_FAILURE);
 304                                 }
 305                                 buf[lenn] = 0;
 306                                 printf("%s", buf);
 307                                 len -= lenn;
 308                                 len -= sizeof(lenn);
 309                                 if(len > 0) {
 310                                         if(read(sock, buf, len) < 0) {
 311                                                 fprintf(stderr, "\nE: could not read export description from server\n");
 312                                                 exit(EXIT_FAILURE);
 313                                         }
 314                                         buf[len] = 0;
 315                                         printf(": %s\n", buf);
 316                                 } else {
 317                                         printf("\n");
 318                                 }
 319                         }
 320                 }
 321         } while(reptype != NBD_REP_ACK);
 322         send_request(sock, NBD_OPT_ABORT, 0, NULL);
 323 }
 324
 325 void parse_sizes(char *buf, uint64_t *size, uint16_t *flags) {
 326         memcpy(size, buf, sizeof(*size));
 327         *size = ntohll(*size);
 328         buf += sizeof(size);
 329         memcpy(flags, buf, sizeof(*flags));
 330         *flags = ntohs(*flags);
 331
 332         if ((*size>>12) > (uint64_t)~0UL) {
 333                 printf("size = %luMB", (unsigned long)(*size>>20));
 334                 err("Exported device is too big for me. Get 64-bit machine :-(\n");
 335         } else {
 336                 printf("size = %luMB", (unsigned long)(*size>>20));
 337         }
 338         printf("\n");
 339 }
 340
 341 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) {
 342         u64 magic;
 343         uint16_t tmp;
 344         uint16_t global_flags;
 345         char buf[256] = "\0\0\0\0\0\0\0\0\0";
 346         uint32_t opt;
 347         uint32_t namesize;
 348         int sock = *sockp;
 349
 350         printf("Negotiation: ");
 351         readit(sock, buf, 8);
 352         if (strcmp(buf, INIT_PASSWD))
 353                 err("INIT_PASSWD bad");
 354         printf(".");
 355         readit(sock, &magic, sizeof(magic));
 356         magic = ntohll(magic);
 357         if (magic != opts_magic) {
 358                 if(magic == cliserv_magic) {
 359                         err("It looks like you're trying to connect to an oldstyle server. This is no longer supported since nbd 3.10.");
 360                 }
 361         }
 362         printf(".");
 363         readit(sock, &tmp, sizeof(uint16_t));
 364         global_flags = ntohs(tmp);
 365         if((needed_flags & global_flags) != needed_flags) {
 366                 /* There's currently really only one reason why this
 367                  * check could possibly fail, but we may need to change
 368                  * this error message in the future... */
 369                 fprintf(stderr, "\nE: Server does not support listing exports\n");
 370                 exit(EXIT_FAILURE);
 371         }
 372
 373         if (global_flags & NBD_FLAG_NO_ZEROES) {
 374                 client_flags |= NBD_FLAG_C_NO_ZEROES;
 375         }
 376         client_flags = htonl(client_flags);
 377         if (write(sock, &client_flags, sizeof(client_flags)) < 0)
 378                 err("Failed/2.1: %m");
 379
 380 #if HAVE_GNUTLS && !defined(NOTLS)
 381         /* TLS */
 382         if (tls) {
 383                 int plainfd[2]; // [0] is used by the proxy, [1] is used by NBD
 384                 tlssession_t *s = NULL;
 385                 int ret;
 386                 uint32_t tmp32;
 387                 uint64_t tmp64;
 388
 389                 send_request(sock, NBD_OPT_STARTTLS, 0, NULL);
 390
 391                 if (read(sock, &tmp64, sizeof(tmp64)) < 0)
 392                         err("Could not read cliserv_magic: %m");
 393                 tmp64 = ntohll(tmp64);
 394                 if (tmp64 != NBD_OPT_REPLY_MAGIC) {
 395                         err("reply magic does not match");
 396                 }
 397                 if (read(sock, &tmp32, sizeof(tmp32)) < 0)
 398                         err("Could not read option type: %m");
 399                 tmp32 = ntohl(tmp32);
 400                 if (tmp32 != NBD_OPT_STARTTLS)
 401                         err("Reply to wrong option");
 402                 if (read(sock, &tmp32, sizeof(tmp32)) < 0)
 403                         err("Could not read option reply type: %m");
 404                 tmp32 = ntohl(tmp32);
 405                 if (tmp32 != NBD_REP_ACK) {
 406                         err("Option reply type != NBD_REP_ACK");
 407                 }
 408                 if (read(sock, &tmp32, sizeof(tmp32)) < 0) err(
 409                         "Could not read option data length: %m");
 410                 tmp32 = ntohl(tmp32);
 411                 if (tmp32 != 0) {
 412                         err("Option reply data length != 0");
 413                 }
 414                 s = tlssession_new(0,
 415                                    keyfile,
 416                                    certfile,
 417                                    cacertfile,
 418                                    tlshostname,
 419                                    !cacertfile || !tlshostname, // insecure flag
 420 #ifdef DODBG
 421                                    1, // debug
 422 #else
 423                                    0, // debug
 424 #endif
 425                                    NULL, // quitfn
 426                                    NULL, // erroutfn
 427                                    NULL // opaque
 428                         );
 429                 if (!s)
 430                         err("Cannot establish TLS session");
 431
 432                 if (socketpair(AF_UNIX, SOCK_STREAM, 0, plainfd) < 0)
 433                         err("Cannot get socket pair");
 434
 435                 if (set_nonblocking(plainfd[0], 0) <0 ||
 436                     set_nonblocking(plainfd[1], 0) <0 ||
 437                     set_nonblocking(sock, 0) <0) {
 438                         close(plainfd[0]);
 439                         close(plainfd[1]);
 440                         err("Cannot set socket options");
 441                 }
 442
 443                 ret = fork();
 444                 if (ret < 0)
 445                         err("Could not fork");
 446                 else if (ret == 0) {
 447                         // we are the child
 448                         if (daemon(0, 0) < 0) {
 449                                 /* no one will see this */
 450                                 fprintf(stderr, "Can't detach from the terminal");
 451                                 exit(1);
 452                         }
 453                         signal (SIGPIPE, SIG_IGN);
 454                         close(plainfd[1]);
 455                         tlssession_mainloop(sock, plainfd[0], s);
 456                         close(sock);
 457                         close(plainfd[0]);
 458                         exit(0);
 459                 }
 460                 close(plainfd[0]);
 461                 close(sock);
 462                 sock = plainfd[1]; /* use the decrypted FD from now on */
 463                 *sockp = sock;
 464         }
 465 #else
 466         if (keyfile) {
 467                 err("TLS requested but support not compiled in");
 468         }
 469 #endif
 470
 471         if(do_opts & NBDC_DO_LIST) {
 472                 ask_list(sock);
 473                 exit(EXIT_SUCCESS);
 474         }
 475
 476         send_info_request(sock, NBD_OPT_GO, 0, NULL, name);
 477
 478         struct reply *rep = NULL;
 479
 480         do {
 481                 if(rep != NULL) free(rep);
 482                 rep = read_reply(sock);
 483                 if(rep->reply_type & NBD_REP_FLAG_ERROR) {
 484                         if(rep->reply_type == NBD_REP_ERR_UNSUP) {
 485                                 free(rep);
 486                                 /* server doesn't support NBD_OPT_GO or NBD_OPT_INFO,
 487                                  * fall back to NBD_OPT_EXPORT_NAME */
 488                                 send_request(sock, NBD_OPT_EXPORT_NAME, -1, name);
 489                                 char b[sizeof(*flags) + sizeof(*rsize64)];
 490                                 readit(sock, b, sizeof(b));
 491                                 parse_sizes(b, rsize64, flags);
 492                                 if(!(global_flags & NBD_FLAG_NO_ZEROES)) {
 493                                         readit(sock, buf, 124);
 494                                 }
 495                                 return;
 496                         } else {
 497                                 err("Unknown error in reply to NBD_OPT_GO; cannot continue");
 498                                 exit(EXIT_FAILURE);
 499                         }
 500                 }
 501                 uint16_t info_type;
 502                 switch(rep->reply_type) {
 503                         case NBD_REP_INFO:
 504                                 memcpy(&info_type, rep->data, 2);
 505                                 info_type = htons(info_type);
 506                                 switch(info_type) {
 507                                         case NBD_INFO_EXPORT:
 508                                                 parse_sizes(rep->data + 2, rsize64, flags);
 509                                                 break;
 510                                         default:
 511                                                 // ignore these, don't need them
 512                                                 break;
 513                                 }
 514                                 break;
 515                         case NBD_REP_ACK:
 516                                 break;
 517                         default:
 518                                 err_nonfatal("Unknown reply to NBD_OPT_GO received");
 519                 }
 520         } while(rep->reply_type != NBD_REP_ACK);
 521         free(rep);
 522 }
 523
 524 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) {
 525         int fd = open(SYSCONFDIR "/nbdtab", O_RDONLY);
 526         bool retval = false;
 527         if(fd < 0) {
 528                 fprintf(stderr, "while opening %s: ", SYSCONFDIR "/nbdtab");
 529                 perror("could not open config file");
 530                 goto out;
 531         }
 532         off_t size = lseek(fd, 0, SEEK_END);
 533         lseek(fd, 0, SEEK_SET);
 534         void *data = NULL;
 535         char *fsep = "\n\t# ";
 536         char *lsep = "\n#";
 537
 538         if(size < 0) {
 539                 perror("E: mmap'ing nbdtab");
 540                 exit(EXIT_FAILURE);
 541         }
 542
 543         data = mmap(NULL, (size_t)size, PROT_READ, MAP_SHARED, fd, 0);
 544         if(!strncmp(cfgname, "/dev/", 5)) {
 545                 cfgname += 5;
 546         }
 547         char *loc = strstr((const char*)data, cfgname);
 548         if(!loc) {
 549                 goto out;
 550         }
 551         size_t l = strlen(cfgname) + 6;
 552         *dev_ptr = malloc(l);
 553         snprintf(*dev_ptr, l, "/dev/%s", cfgname);
 554
 555         size_t line_len, field_len, ws_len;
 556 #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; }
 557 #define MOVE_NEXT line_len -= field_len + ws_len; loc += field_len + ws_len
 558         // find length of line
 559         line_len = strcspn(loc, lsep);
 560         // first field is the device node name, which we already know, so skip it
 561         CHECK_LEN;
 562         MOVE_NEXT;
 563         // next field is the hostname
 564         CHECK_LEN;
 565         *hostn_ptr = strndup(loc, field_len);
 566         MOVE_NEXT;
 567         // third field is the export name
 568         CHECK_LEN;
 569         *name_ptr = strndup(loc, field_len);
 570         if(ws_len + field_len > line_len) {
 571                 // optional last field is not there, so return success
 572                 retval = true;
 573                 goto out;
 574         }
 575         MOVE_NEXT;
 576         CHECK_LEN;
 577 #undef CHECK_LEN
 578 #undef MOVE_NEXT
 579         // fourth field is the options field, a comma-separated field of options
 580         do {
 581                 if(!strncmp(loc, "conns=", 6)) {
 582                         *num_conns = (int)strtol(loc+6, &loc, 0);
 583                         goto next;
 584                 }
 585                 if(!strncmp(loc, "bs=", 3)) {
 586                         *bs = (int)strtol(loc+3, &loc, 0);
 587                         goto next;
 588                 }
 589                 if(!strncmp(loc, "timeout=", 8)) {
 590                         *timeout = (int)strtol(loc+8, &loc, 0);
 591                         goto next;
 592                 }
 593                 if(!strncmp(loc, "port=", 5)) {
 594                         *port = strndup(loc+5, strcspn(loc+5, ","));
 595                         goto next;
 596                 }
 597                 if(!strncmp(loc, "persist", 7)) {
 598                         loc += 7;
 599                         *persist = 1;
 600                         goto next;
 601                 }
 602                 if(!strncmp(loc, "swap", 4)) {
 603                         *swap = 1;
 604                         loc += 4;
 605                         goto next;
 606                 }
 607                 if(!strncmp(loc, "sdp", 3)) {
 608                         *sdp = 1;
 609                         loc += 3;
 610                         goto next;
 611                 }
 612                 if(!strncmp(loc, "unix", 4)) {
 613                         *b_unix = 1;
 614                         loc += 4;
 615                         goto next;
 616                 }
 617                 if(!strncmp(loc, "certfile=", 9)) {
 618                         *certfile = strndup(loc+9, strcspn(loc+9, ","));
 619                         goto next;
 620                 }
 621                 if(!strncmp(loc, "keyfile=", 8)) {
 622                         *keyfile = strndup(loc+8, strcspn(loc+8, ","));
 623                         goto next;
 624                 }
 625                 if(!strncmp(loc, "cacertfile=", 11)) {
 626                         *cacertfile = strndup(loc+11, strcspn(loc+11, ","));
 627                         goto next;
 628                 }
 629                 if(!strncmp(loc, "tlshostname=", 9)) {
 630                         *tlshostname = strndup(loc+9, strcspn(loc+9, ","));
 631                         goto next;
 632                 }
 633                 // skip unknown options, with a warning unless they start with a '_'
 634                 l = strcspn(loc, ",");
 635                 if(*loc != '_') {
 636                         char* s = strndup(loc, l);
 637                         fprintf(stderr, "Warning: unknown option '%s' found in nbdtab file", s);
 638                         free(s);
 639                 }
 640                 loc += l;
 641 next:
 642                 if(*loc == ',') {
 643                         loc++;
 644                 }
 645         } while(strcspn(loc, lsep) > 0);
 646         retval = true;
 647 out:
 648         if(data != NULL) {
 649                 munmap(data, size);
 650         }
 651         if(fd >= 0) {
 652                 close(fd);
 653         }
 654         return retval;
 655 }
 656
 657 void setsizes(int nbd, u64 size64, int blocksize, u32 flags) {
 658         unsigned long size;
 659         int read_only = (flags & NBD_FLAG_READ_ONLY) ? 1 : 0;
 660
 661         if (size64>>12 > (uint64_t)~0UL)
 662                 err("Device too large.\n");
 663         else {
 664                 int tmp_blocksize = 4096;
 665                 if (size64 / (u64)blocksize <= (uint64_t)~0UL)
 666                         tmp_blocksize = blocksize;
 667                 if (ioctl(nbd, NBD_SET_BLKSIZE, tmp_blocksize) < 0) {
 668                         fprintf(stderr, "Failed to set blocksize %d\n",
 669                                 tmp_blocksize);
 670                         err("Ioctl/1.1a failed: %m\n");
 671                 }
 672                 size = (unsigned long)(size64 / (u64)tmp_blocksize);
 673                 if (ioctl(nbd, NBD_SET_SIZE_BLOCKS, size) < 0)
 674                         err("Ioctl/1.1b failed: %m\n");
 675                 if (tmp_blocksize != blocksize) {
 676                         if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0) {
 677                                 fprintf(stderr, "Failed to set blocksize %d\n",
 678                                         blocksize);
 679                                 err("Ioctl/1.1c failed: %m\n");
 680                         }
 681                 }
 682                 fprintf(stderr, "bs=%d, sz=%" PRIu64 " bytes\n", blocksize, (u64)tmp_blocksize * size);
 683         }
 684
 685         ioctl(nbd, NBD_CLEAR_SOCK);
 686
 687         /* ignore error as kernel may not support */
 688         ioctl(nbd, NBD_SET_FLAGS, (unsigned long) flags);
 689
 690         if (ioctl(nbd, BLKROSET, (unsigned long) &read_only) < 0)
 691                 err("Unable to set read-only attribute for device");
 692 }
 693
 694 void set_timeout(int nbd, int timeout) {
 695         if (timeout) {
 696                 if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)timeout) < 0)
 697                         err("Ioctl NBD_SET_TIMEOUT failed: %m\n");
 698                 fprintf(stderr, "timeout=%d\n", timeout);
 699         }
 700 }
 701
 702 void finish_sock(int sock, int nbd, int swap) {
 703         if (ioctl(nbd, NBD_SET_SOCK, sock) < 0) {
 704                 if (errno == EBUSY)
 705                         err("Kernel doesn't support multiple connections\n");
 706                 else
 707                         err("Ioctl NBD_SET_SOCK failed: %m\n");
 708         }
 709
 710 #ifndef __ANDROID__
 711         if (swap)
 712                 mlockall(MCL_CURRENT | MCL_FUTURE);
 713 #endif
 714 }
 715
 716 static int
 717 oom_adjust(const char *file, const char *value)
 718 {
 719         int fd, rc;
 720         size_t len;
 721
 722         fd = open(file, O_WRONLY);
 723         if (fd < 0)
 724                 return -1;
 725         len = strlen(value);
 726         rc = write(fd, value, len) != (ssize_t) len;
 727         close(fd);
 728         return rc ? -1 : 0;
 729 }
 730
 731 void usage(char* errmsg, ...) {
 732         if(errmsg) {
 733                 char tmp[256];
 734                 va_list ap;
 735                 va_start(ap, errmsg);
 736                 snprintf(tmp, 256, "ERROR: %s\n\n", errmsg);
 737                 vfprintf(stderr, tmp, ap);
 738                 va_end(ap);
 739         } else {
 740                 fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION);
 741         }
 742         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");
 743         fprintf(stderr, "Or   : nbd-client -u (with same arguments as above)\n");
 744         fprintf(stderr, "Or   : nbd-client nbdX\n");
 745         fprintf(stderr, "Or   : nbd-client -d nbd_device\n");
 746         fprintf(stderr, "Or   : nbd-client -c nbd_device\n");
 747         fprintf(stderr, "Or   : nbd-client -h|--help\n");
 748         fprintf(stderr, "Or   : nbd-client -l|--list host\n");
 749 #if HAVE_GNUTLS && !defined(NOTLS)
 750         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");
 751 #endif
 752         fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n");
 753         fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
 754         fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
 755         fprintf(stderr, "blocksizes other than 1024 without patches\n");
 756         fprintf(stderr, "Default value for port is 10809. Note that port must always be numeric\n");
 757 }
 758
 759 void disconnect(char* device) {
 760         int nbd = open(device, O_RDWR);
 761
 762         if (nbd < 0)
 763                 err("Cannot open NBD: %m\nPlease ensure the 'nbd' module is loaded.");
 764         printf("disconnect, ");
 765         if (ioctl(nbd, NBD_DISCONNECT)<0)
 766                 err("Ioctl failed: %m\n");
 767         printf("sock, ");
 768         if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
 769                 err("Ioctl failed: %m\n");
 770         printf("done\n");
 771 }
 772
 773 int main(int argc, char *argv[]) {
 774         char* port=NBD_DEFAULT_PORT;
 775         int sock, nbd;
 776         int blocksize=1024;
 777         char *hostname=NULL;
 778         char *nbddev=NULL;
 779         int swap=0;
 780         int cont=0;
 781         int timeout=0;
 782         int sdp=0;
 783         int G_GNUC_UNUSED nofork=0; // if -dNOFORK
 784         pid_t main_pid;
 785         u64 size64;
 786         uint16_t flags = 0;
 787         int c;
 788         int nonspecial=0;
 789         int b_unix=0;
 790         char* name="";
 791         uint16_t needed_flags=0;
 792         uint32_t cflags=NBD_FLAG_C_FIXED_NEWSTYLE;
 793         uint32_t opts=0;
 794         sigset_t block, old;
 795         char *certfile = NULL;
 796         char *keyfile = NULL;
 797         char *cacertfile = NULL;
 798         char *tlshostname = NULL;
 799         bool tls = false;
 800         struct sigaction sa;
 801         int num_connections = 1;
 802         struct option long_options[] = {
 803                 { "block-size", required_argument, NULL, 'b' },
 804                 { "check", required_argument, NULL, 'c' },
 805                 { "connections", required_argument, NULL, 'C'},
 806                 { "disconnect", required_argument, NULL, 'd' },
 807                 { "help", no_argument, NULL, 'h' },
 808                 { "list", no_argument, NULL, 'l' },
 809                 { "name", required_argument, NULL, 'N' },
 810                 { "nofork", no_argument, NULL, 'n' },
 811                 { "persist", no_argument, NULL, 'p' },
 812                 { "sdp", no_argument, NULL, 'S' },
 813                 { "swap", no_argument, NULL, 's' },
 814                 { "systemd-mark", no_argument, NULL, 'm' },
 815                 { "timeout", required_argument, NULL, 't' },
 816                 { "unix", no_argument, NULL, 'u' },
 817                 { "certfile", required_argument, NULL, 'F' },
 818                 { "keyfile", required_argument, NULL, 'K' },
 819                 { "cacertfile", required_argument, NULL, 'A' },
 820                 { "tlshostname", required_argument, NULL, 'H' },
 821                 { "enable-tls", no_argument, NULL, 'x' },
 822                 { 0, 0, 0, 0 },
 823         };
 824         int i;
 825
 826         logging(MY_NAME);
 827
 828 #if HAVE_GNUTLS && !defined(NOTLS)
 829         tlssession_init();
 830 #endif
 831
 832         while((c=getopt_long_only(argc, argv, "-b:c:d:hlnN:pSst:uC:K:A:H:x", long_options, NULL))>=0) {
 833                 switch(c) {
 834                 case 1:
 835                         // non-option argument
 836                         if(strchr(optarg, '=')) {
 837                                 // old-style 'bs=' or 'timeout='
 838                                 // argument
 839                                 fprintf(stderr, "WARNING: old-style command-line argument encountered. This is deprecated.\n");
 840                                 if(!strncmp(optarg, "bs=", 3)) {
 841                                         optarg+=3;
 842                                         goto blocksize;
 843                                 }
 844                                 if(!strncmp(optarg, "timeout=", 8)) {
 845                                         optarg+=8;
 846                                         goto timeout;
 847                                 }
 848                                 usage("unknown option %s encountered", optarg);
 849                                 exit(EXIT_FAILURE);
 850                         }
 851                         switch(nonspecial++) {
 852                                 case 0:
 853                                         // host
 854                                         hostname=optarg;
 855                                         break;
 856                                 case 1:
 857                                         // port
 858                                         if(!strtol(optarg, NULL, 0)) {
 859                                                 // not parseable as a number, assume it's the device
 860                                                 nbddev = optarg;
 861                                                 nonspecial++;
 862                                         } else {
 863                                                 port = optarg;
 864                                         }
 865                                         break;
 866                                 case 2:
 867                                         // device
 868                                         nbddev = optarg;
 869                                         break;
 870                                 default:
 871                                         usage("too many non-option arguments specified");
 872                                         exit(EXIT_FAILURE);
 873                         }
 874                         break;
 875                 case 'b':
 876                       blocksize:
 877                         blocksize=(int)strtol(optarg, NULL, 0);
 878                         break;
 879                 case 'c':
 880                         return check_conn(optarg, 1);
 881                 case 'C':
 882                         num_connections = (int)strtol(optarg, NULL, 0);
 883                         break;
 884                 case 'd':
 885                         disconnect(optarg);
 886                         exit(EXIT_SUCCESS);
 887                 case 'h':
 888                         usage(NULL);
 889                         exit(EXIT_SUCCESS);
 890                 case 'l':
 891                         needed_flags |= NBD_FLAG_FIXED_NEWSTYLE;
 892                         opts |= NBDC_DO_LIST;
 893                         nbddev="";
 894                         break;
 895                 case 'm':
 896                         argv[0][0] = '@';
 897                         break;
 898                 case 'n':
 899                         nofork=1;
 900                         break;
 901                 case 'N':
 902                         name=optarg;
 903                         break;
 904                 case 'p':
 905                         cont=1;
 906                         break;
 907                 case 's':
 908                         swap=1;
 909                         break;
 910                 case 'S':
 911                         sdp=1;
 912                         break;
 913                 case 't':
 914                       timeout:
 915                         timeout=strtol(optarg, NULL, 0);
 916                         break;
 917                 case 'u':
 918                         b_unix = 1;
 919                         break;
 920 #if HAVE_GNUTLS && !defined(NOTLS)
 921                 case 'x':
 922                         tls = true;
 923                         break;
 924                 case 'F':
 925                         certfile=strdup(optarg);
 926                         break;
 927                 case 'K':
 928                         keyfile=strdup(optarg);
 929                         break;
 930                 case 'A':
 931                         cacertfile=strdup(optarg);
 932                         break;
 933                 case 'H':
 934                         tlshostname=strdup(optarg);
 935                         break;
 936 #else
 937                 case 'F':
 938                 case 'K':
 939                 case 'H':
 940                 case 'A':
 941                         fprintf(stderr, "E: TLS support not compiled in\n");
 942                         exit(EXIT_FAILURE);
 943 #endif
 944                 default:
 945                         fprintf(stderr, "E: option eaten by 42 mice\n");
 946                         exit(EXIT_FAILURE);
 947                 }
 948         }
 949
 950 #ifdef __ANDROID__
 951   if (swap)
 952     err("swap option unsupported on Android because mlockall is unsupported.");
 953 #endif
 954         if(hostname) {
 955                 if((!name || !nbddev) && !(opts & NBDC_DO_LIST)) {
 956                         if(!strncmp(hostname, "nbd", 3) || !strncmp(hostname, "/dev/nbd", 8)) {
 957                                 if(!get_from_config(hostname, &name, &nbddev, &hostname, &blocksize, &timeout, &cont, &swap, &sdp, &b_unix, &port, &num_connections, &certfile, &keyfile, &cacertfile, &hostname)) {
 958                                         usage("no valid configuration for specified device found", hostname);
 959                                         exit(EXIT_FAILURE);
 960                                 }
 961                         } else {
 962                                 usage("not enough information specified, and argument didn't look like an nbd device");
 963                                 exit(EXIT_FAILURE);
 964                         }
 965                 }
 966         } else {
 967                 usage("no information specified");
 968                 exit(EXIT_FAILURE);
 969         }
 970
 971         if (keyfile && !certfile)
 972                 certfile = strdup(keyfile);
 973
 974         if (certfile != NULL || keyfile != NULL || cacertfile != NULL || tlshostname != NULL) {
 975                 tls = true;
 976         }
 977
 978         if (!tlshostname && hostname)
 979                 tlshostname = strdup(hostname);
 980
 981         if(strlen(name)==0 && !(opts & NBDC_DO_LIST)) {
 982                 printf("Warning: the oldstyle protocol is no longer supported.\nThis method now uses the newstyle protocol with a default export\n");
 983         }
 984
 985         if(!opts & NBDC_DO_LIST) {
 986                 nbd = open(nbddev, O_RDWR);
 987                 if (nbd < 0)
 988                         err("Cannot open NBD: %m\nPlease ensure the 'nbd' module is loaded.");
 989         }
 990
 991         for (i = 0; i < num_connections; i++) {
 992                 if (b_unix)
 993                         sock = openunix(hostname);
 994                 else
 995                         sock = opennet(hostname, port, sdp);
 996                 if (sock < 0)
 997                         exit(EXIT_FAILURE);
 998
 999                 negotiate(&sock, &size64, &flags, name, needed_flags, cflags, opts, certfile, keyfile, cacertfile, tlshostname, tls);
1000                 if (i == 0) {
1001                         setsizes(nbd, size64, blocksize, flags);
1002                         set_timeout(nbd, timeout);
1003                 }
1004                 finish_sock(sock, nbd, swap);
1005                 if (swap) {
1006                         if (keyfile)
1007                                 fprintf(stderr, "Warning: using swap and TLS is prone to deadlock\n");
1008                         /* try linux >= 2.6.36 interface first */
1009                         if (oom_adjust("/proc/self/oom_score_adj", "-1000")) {
1010                                 /* fall back to linux <= 2.6.35 interface */
1011                                 oom_adjust("/proc/self/oom_adj", "-17");
1012                         }
1013                 }
1014         }
1015
1016         /* Go daemon */
1017
1018 #ifndef NOFORK
1019         if(!nofork) {
1020                 if (daemon(0,0) < 0)
1021                         err("Cannot detach from terminal");
1022         }
1023
1024         memset(&sa, 0, sizeof(sa));
1025         sa.sa_handler = SIG_IGN;
1026         sigaction(SIGCHLD, &sa, NULL);
1027 #endif
1028         /* For child to check its parent */
1029         main_pid = getpid();
1030         do {
1031 #ifndef NOFORK
1032
1033                 sigfillset(&block);
1034                 sigdelset(&block, SIGKILL);
1035                 sigdelset(&block, SIGTERM);
1036                 sigdelset(&block, SIGPIPE);
1037                 sigprocmask(SIG_SETMASK, &block, &old);
1038
1039                 if (!fork()) {
1040                         /* Due to a race, the kernel NBD driver cannot
1041                          * call for a reread of the partition table
1042                          * in the handling of the NBD_DO_IT ioctl().
1043                          * Therefore, this is done in the first open()
1044                          * of the device. We therefore make sure that
1045                          * the device is opened at least once after the
1046                          * connection was made. This has to be done in a
1047                          * separate process, since the NBD_DO_IT ioctl()
1048                          * does not return until the NBD device has
1049                          * disconnected.
1050                          */
1051                         struct timespec req = {
1052                                 .tv_sec = 0,
1053                                 .tv_nsec = 100000000,
1054                         };
1055                         while(check_conn(nbddev, 0)) {
1056                                 if (main_pid != getppid()) {
1057                                         /* check_conn() will not return 0 when nbd disconnected
1058                                          * and parent exited during this loop. So the child has to
1059                                          * explicitly check parent identity and exit if parent
1060                                          * exited */
1061                                         exit(0);
1062                                 }
1063                                 nanosleep(&req, NULL);
1064                         }
1065                         open(nbddev, O_RDONLY);
1066                         exit(0);
1067                 }
1068 #endif
1069
1070                 if (ioctl(nbd, NBD_DO_IT) < 0) {
1071                         int error = errno;
1072                         fprintf(stderr, "nbd,%d: Kernel call returned: %d", main_pid, error);
1073                         if(error==EBADR) {
1074                                 /* The user probably did 'nbd-client -d' on us.
1075                                  * quit */
1076                                 cont=0;
1077                         } else {
1078                                 if(cont) {
1079                                         u64 new_size;
1080                                         uint16_t new_flags;
1081
1082                                         close(sock); close(nbd);
1083                                         for (;;) {
1084                                                 fprintf(stderr, " Reconnecting\n");
1085                                                 if (b_unix)
1086                                                         sock = openunix(hostname);
1087                                                 else
1088                                                         sock = opennet(hostname, port, sdp);
1089                                                 if (sock >= 0)
1090                                                         break;
1091                                                 sleep (1);
1092                                         }
1093                                         nbd = open(nbddev, O_RDWR);
1094                                         if (nbd < 0)
1095                                                 err("Cannot open NBD: %m");
1096                                         negotiate(&sock, &new_size, &new_flags, name, needed_flags, cflags, opts, certfile, keyfile, cacertfile, tlshostname, tls);
1097                                         if (size64 != new_size) {
1098                                                 err("Size of the device changed. Bye");
1099                                         }
1100                                         setsizes(nbd, size64, blocksize,
1101                                                                 new_flags);
1102
1103                                         set_timeout(nbd, timeout);
1104                                         finish_sock(sock,nbd,swap);
1105                                 }
1106                         }
1107                 } else {
1108                         /* We're on 2.4. It's not clearly defined what exactly
1109                          * happened at this point. Probably best to quit, now
1110                          */
1111                         fprintf(stderr, "Kernel call returned.");
1112                         cont=0;
1113                 }
1114         } while(cont);
1115         printf("sock, ");
1116         ioctl(nbd, NBD_CLEAR_SOCK);
1117         printf("done\n");
1118         return 0;
1119 }