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
  49 #if HAVE_NETLINK
  50 #include "nbd-netlink.h"
  51 #include <netlink/netlink.h>
  52 #include <netlink/genl/genl.h>
  53 #include <netlink/genl/ctrl.h>
  54 #endif
  55
  56 #define MY_NAME "nbd_client"
  57 #include "cliserv.h"
  58
  59 #if HAVE_GNUTLS && !defined(NOTLS)
  60 #include "crypto-gnutls.h"
  61 #endif
  62
  63 #include "nbdclt.h"
  64 #include "nbdtab_parser.tab.h"
  65
  66 CLIENT* cur_client;
  67 extern FILE *yyin, *yyout;
  68 bool found_config = false;
  69 bool parse_error = false;
  70
  71 #define SET_PROP(str, member, rval) if(!strcmp(property, str)) { cur_client->member = (rval); return; }
  72 void nbdtab_set_property(char *property, char *val) {
  73         if(found_config) return;
  74         SET_PROP("port", port, val);
  75         SET_PROP("certfile", cert, val);
  76         SET_PROP("keyfile", key, val);
  77         SET_PROP("cacertfile", cacert, val);
  78         SET_PROP("tlshostname", tlshostn, val);
  79         SET_PROP("priority", priority, val);
  80         SET_PROP("bs", bs, strtol(val, NULL, 10));
  81         SET_PROP("timeout", timeout, strtol(val, NULL, 10));
  82         SET_PROP("conns", nconn, strtol(val, NULL, 10));
  83         if(*property != '_') {
  84                 fprintf(stderr, "Warning: unknown option '%s' found in nbdtab file", property);
  85         }
  86 }
  87 #undef SET_PROP
  88
  89 #define SET_FLAG(str, member) if(!strcmp(property, str)) { cur_client->member = true; return; }
  90 void nbdtab_set_flag(char *property) {
  91         if(found_config) return;
  92         SET_FLAG("no_optgo", no_optgo);
  93         SET_FLAG("persist", persist);
  94         SET_FLAG("swap", swap);
  95         SET_FLAG("unix", b_unix);
  96         SET_FLAG("preinit", preinit);
  97         SET_FLAG("tls", tls);
  98         if(*property != '_') {
  99                 fprintf(stderr, "Warning: unknown option '%s' found in nbdtab file", property);
 100         }
 101 }
 102
 103 void nbdtab_commit_line(char *devn, char *hostn, char *exportname) {
 104         if(!strncmp(devn, "/dev/", 5)) {
 105                 devn += 5;
 106         }
 107         if(!strcmp(cur_client->dev, devn)) {
 108                 found_config = true;
 109                 cur_client->hostn = hostn;
 110                 cur_client->name = exportname;
 111         } else {
 112                 if(!found_config) {
 113                         char *tmp = cur_client->dev;
 114                         memset(cur_client, 0, sizeof(CLIENT));
 115                         cur_client->bs = 512;
 116                         cur_client->nconn = 1;
 117                         cur_client->dev = tmp;
 118                 }
 119         }
 120         return;
 121 }
 122
 123 void yyerror(char *msg) {
 124         parse_error = true;
 125         fprintf(stderr, "parse error parsing " SYSCONFDIR "/nbdtab: %s", msg);
 126 }
 127
 128 #undef SET_FLAG
 129
 130 #define NBDC_DO_LIST 1
 131
 132 #if HAVE_NETLINK
 133 static int callback(struct nl_msg *msg, void *arg) {
 134         struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
 135         struct nlattr *msg_attr[NBD_ATTR_MAX + 1];
 136         int ret;
 137         uint32_t index;
 138
 139         ret = nla_parse(msg_attr, NBD_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
 140                         genlmsg_attrlen(gnlh, 0), NULL);
 141         if (ret)
 142                 err("Invalid response from the kernel\n");
 143         if (!msg_attr[NBD_ATTR_INDEX])
 144                 err("Did not receive index from the kernel\n");
 145         index = nla_get_u32(msg_attr[NBD_ATTR_INDEX]);
 146         printf("Connected /dev/nbd%d\n", (int)index);
 147         return NL_OK;
 148 }
 149
 150 static struct nl_sock *get_nbd_socket(int *driver_id) {
 151         struct nl_sock *socket;
 152
 153         socket = nl_socket_alloc();
 154         if (!socket)
 155                 err("Couldn't allocate netlink socket\n");
 156
 157         if (genl_connect(socket))
 158                 err("Couldn't connect to the generic netlink socket\n");
 159         *driver_id = genl_ctrl_resolve(socket, "nbd");
 160         if (*driver_id < 0)
 161                 err("Couldn't resolve the nbd netlink family, make sure the nbd module is loaded and your nbd driver supports the netlink interface.\n");
 162         return socket;
 163 }
 164
 165 static void netlink_configure(int index, int *sockfds, int num_connects,
 166                               u64 size64, int blocksize, uint16_t flags,
 167                               int timeout) {
 168         struct nl_sock *socket;
 169         struct nlattr *sock_attr;
 170         struct nl_msg *msg;
 171         int driver_id, i;
 172
 173         socket = get_nbd_socket(&driver_id);
 174         nl_socket_modify_cb(socket, NL_CB_VALID, NL_CB_CUSTOM, callback, NULL);
 175
 176         msg = nlmsg_alloc();
 177         if (!msg)
 178                 err("Couldn't allocate netlink message\n");
 179         genlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, driver_id, 0, 0,
 180                     NBD_CMD_CONNECT, 0);
 181         if (index >= 0)
 182                 NLA_PUT_U32(msg, NBD_ATTR_INDEX, index);
 183         NLA_PUT_U64(msg, NBD_ATTR_SIZE_BYTES, size64);
 184         NLA_PUT_U64(msg, NBD_ATTR_BLOCK_SIZE_BYTES, blocksize);
 185         NLA_PUT_U64(msg, NBD_ATTR_SERVER_FLAGS, flags);
 186         if (timeout)
 187                 NLA_PUT_U64(msg, NBD_ATTR_TIMEOUT, timeout);
 188
 189         sock_attr = nla_nest_start(msg, NBD_ATTR_SOCKETS);
 190         if (!sock_attr)
 191                 err("Couldn't nest the sockets for our connection\n");
 192         for (i = 0; i < num_connects; i++) {
 193                 struct nlattr *sock_opt;
 194                 sock_opt = nla_nest_start(msg, NBD_SOCK_ITEM);
 195                 if (!sock_opt)
 196                         err("Couldn't nest the sockets for our connection\n");
 197                 NLA_PUT_U32(msg, NBD_SOCK_FD, sockfds[i]);
 198                 nla_nest_end(msg, sock_opt);
 199         }
 200         nla_nest_end(msg, sock_attr);
 201
 202         if (nl_send_sync(socket, msg) < 0)
 203                 err("Failed to setup device, check dmesg\n");
 204         return;
 205 nla_put_failure:
 206         err("Failed to create netlink message\n");
 207 }
 208
 209 static void netlink_disconnect(char *nbddev) {
 210         struct nl_sock *socket;
 211         struct nl_msg *msg;
 212         int driver_id;
 213
 214         int index = -1;
 215         if (nbddev) {
 216                 if (sscanf(nbddev, "/dev/nbd%d", &index) != 1)
 217                         err("Invalid nbd device target\n");
 218         }
 219         if (index < 0)
 220                 err("Invalid nbd device target\n");
 221
 222         socket = get_nbd_socket(&driver_id);
 223
 224         msg = nlmsg_alloc();
 225         if (!msg)
 226                 err("Couldn't allocate netlink message\n");
 227         genlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, driver_id, 0, 0,
 228                     NBD_CMD_DISCONNECT, 0);
 229         NLA_PUT_U32(msg, NBD_ATTR_INDEX, index);
 230         if (nl_send_sync(socket, msg) < 0)
 231                 err("Failed to disconnect device, check dmsg\n");
 232         nl_socket_free(socket);
 233         return;
 234 nla_put_failure:
 235         err("Failed to create netlink message\n");
 236 }
 237 #else
 238 static void netlink_configure(int index, int *sockfds, int num_connects,
 239                               u64 size64, int blocksize, uint16_t flags,
 240                               int timeout)
 241 {
 242 }
 243
 244 static void netlink_disconnect(char *nbddev)
 245 {
 246 }
 247 #endif /* HAVE_NETLINK */
 248
 249 int check_conn(char* devname, int do_print) {
 250         char buf[256];
 251         char* p;
 252         int fd;
 253         int len;
 254
 255         if( (p=strrchr(devname, '/')) ) {
 256                 devname=p+1;
 257         }
 258         if((p=strchr(devname, 'p'))) {
 259                 /* We can't do checks on partitions. */
 260                 *p='\0';
 261         }
 262         snprintf(buf, 256, "/sys/block/%s/pid", devname);
 263         if((fd=open(buf, O_RDONLY))<0) {
 264                 if(errno==ENOENT) {
 265                         return 1;
 266                 } else {
 267                         return 2;
 268                 }
 269         }
 270         len=read(fd, buf, 256);
 271         if(len < 0) {
 272                 perror("could not read from server");
 273                 close(fd);
 274                 return 2;
 275         }
 276         buf[(len < 256) ? len : 255]='\0';
 277         if(do_print) printf("%s\n", buf);
 278         close(fd);
 279         return 0;
 280 }
 281
 282 int opennet(char *name, char* portstr) {
 283         int sock;
 284         struct addrinfo hints;
 285         struct addrinfo *ai = NULL;
 286         struct addrinfo *rp = NULL;
 287         int e;
 288
 289         memset(&hints,'\0',sizeof(hints));
 290         hints.ai_family = AF_UNSPEC;
 291         hints.ai_socktype = SOCK_STREAM;
 292         hints.ai_flags = AI_ADDRCONFIG | AI_NUMERICSERV;
 293         hints.ai_protocol = IPPROTO_TCP;
 294
 295         e = getaddrinfo(name, portstr, &hints, &ai);
 296
 297         if(e != 0) {
 298                 fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
 299                 freeaddrinfo(ai);
 300                 return -1;
 301         }
 302
 303         for(rp = ai; rp != NULL; rp = rp->ai_next) {
 304                 sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 305
 306                 if(sock == -1)
 307                         continue;       /* error */
 308
 309                 if(connect(sock, rp->ai_addr, rp->ai_addrlen) != -1)
 310                         break;          /* success */
 311
 312                 close(sock);
 313         }
 314
 315         if (rp == NULL) {
 316                 err_nonfatal("Socket failed: %m");
 317                 sock = -1;
 318                 goto err;
 319         }
 320
 321         setmysockopt(sock);
 322 err:
 323         freeaddrinfo(ai);
 324         return sock;
 325 }
 326
 327 int openunix(const char *path) {
 328         int sock;
 329         struct sockaddr_un un_addr;
 330         memset(&un_addr, 0, sizeof(un_addr));
 331
 332         un_addr.sun_family = AF_UNIX;
 333         if (strnlen(path, sizeof(un_addr.sun_path)) == sizeof(un_addr.sun_path)) {
 334                 err_nonfatal("UNIX socket path too long");
 335                 return -1;
 336         }
 337
 338         strncpy(un_addr.sun_path, path, sizeof(un_addr.sun_path) - 1);
 339
 340         if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
 341                 err_nonfatal("SOCKET failed");
 342                 return -1;
 343         };
 344
 345         if (connect(sock, (struct sockaddr*)&un_addr, sizeof(un_addr)) == -1) {
 346                 err_nonfatal("CONNECT failed");
 347                 close(sock);
 348                 return -1;
 349         }
 350         return sock;
 351 }
 352
 353 void send_request(int sock, uint32_t opt, ssize_t datasize, void* data) {
 354         struct {
 355                 uint64_t magic;
 356                 uint32_t opt;
 357                 uint32_t datasize;
 358         } __attribute__((packed)) header = {
 359                 ntohll(opts_magic),
 360                 ntohl(opt),
 361                 ntohl(datasize),
 362         };
 363         if(datasize < 0) {
 364                 datasize = strlen((char*)data);
 365                 header.datasize = htonl(datasize);
 366         }
 367         writeit(sock, &header, sizeof(header));
 368         if(data != NULL) {
 369                 writeit(sock, data, datasize);
 370         }
 371 }
 372
 373 void send_info_request(int sock, uint32_t opt, int n_reqs, uint16_t* reqs, char* name) {
 374         uint16_t rlen = htons(n_reqs);
 375         uint32_t nlen = htonl(strlen(name));
 376
 377         send_request(sock, opt, sizeof(uint32_t) + strlen(name) + sizeof(uint16_t) + n_reqs * sizeof(uint16_t), NULL);
 378         writeit(sock, &nlen, sizeof(nlen));
 379         writeit(sock, name, strlen(name));
 380         writeit(sock, &rlen, sizeof(rlen));
 381         if(n_reqs > 0) {
 382                 writeit(sock, reqs, n_reqs * sizeof(uint16_t));
 383         }
 384 }
 385
 386 struct reply {
 387         uint64_t magic;
 388         uint32_t opt;
 389         uint32_t reply_type;
 390         uint32_t datasize;
 391         char data[];
 392 } __attribute__((packed));
 393
 394 struct reply* read_reply(int sock) {
 395         struct reply *retval = malloc(sizeof(struct reply));
 396
 397         if (retval == NULL)
 398                 return NULL;
 399
 400         if(readit(sock, retval, sizeof(*retval)) < 0) {
 401                 free(retval);
 402                 return NULL;
 403         }
 404
 405         retval->magic = ntohll(retval->magic);
 406         retval->opt = ntohl(retval->opt);
 407         retval->reply_type = ntohl(retval->reply_type);
 408         retval->datasize = ntohl(retval->datasize);
 409         if (retval->magic != rep_magic) {
 410                 fprintf(stderr, "E: received invalid negotiation magic %" PRIu64 " (expected %" PRIu64 ")", retval->magic, rep_magic);
 411                 exit(EXIT_FAILURE);
 412         }
 413         if (retval->datasize > 0 && retval->datasize < 4096) {
 414                 struct reply *retval_r = realloc(retval, sizeof(struct reply) + retval->datasize);
 415                 if (retval_r == NULL) {
 416                         free(retval);
 417                         return NULL;
 418                 }
 419                 retval = retval_r;
 420                 readit(sock, &(retval->data), retval->datasize);
 421         }
 422         return retval;
 423 }
 424
 425 void ask_list(int sock) {
 426         uint32_t opt_server;
 427         uint32_t len;
 428         uint32_t lenn;
 429         uint32_t reptype;
 430         uint64_t magic;
 431         int rlen;
 432         const int BUF_SIZE = 1024;
 433         char buf[BUF_SIZE];
 434
 435         send_request(sock, NBD_OPT_LIST, 0, NULL);
 436         /* newline, move away from the "Negotiation:" line */
 437         printf("\n");
 438         do {
 439                 memset(buf, 0, 1024);
 440                 if(read(sock, &magic, sizeof(magic)) < 0) {
 441                         err("Reading magic from server: %m");
 442                 }
 443                 if(read(sock, &opt_server, sizeof(opt_server)) < 0) {
 444                         err("Reading option: %m");
 445                 }
 446                 if(read(sock, &reptype, sizeof(reptype)) <0) {
 447                         err("Reading reply from server: %m");
 448                 }
 449                 if(read(sock, &len, sizeof(len)) < 0) {
 450                         err("Reading length from server: %m");
 451                 }
 452                 magic=ntohll(magic);
 453                 len=ntohl(len);
 454                 reptype=ntohl(reptype);
 455                 if(magic != rep_magic) {
 456                         err("Not enough magic from server");
 457                 }
 458                 if(reptype & NBD_REP_FLAG_ERROR) {
 459                         switch(reptype) {
 460                                 case NBD_REP_ERR_POLICY:
 461                                         fprintf(stderr, "\nE: listing not allowed by server.\n");
 462                                         break;
 463                                 default:
 464                                         fprintf(stderr, "\nE: unexpected error from server.\n");
 465                                         break;
 466                         }
 467                         if(len > 0 && len < BUF_SIZE) {
 468                                 if((rlen=read(sock, buf, len)) < 0) {
 469                                         fprintf(stderr, "\nE: could not read error message from server\n");
 470                                 } else {
 471                                         buf[rlen] = '\0';
 472                                         fprintf(stderr, "Server said: %s\n", buf);
 473                                 }
 474                         }
 475                         exit(EXIT_FAILURE);
 476                 } else {
 477                         if(reptype != NBD_REP_ACK) {
 478                                 if(reptype != NBD_REP_SERVER) {
 479                                         err("Server sent us a reply we don't understand!");
 480                                 }
 481                                 if(read(sock, &lenn, sizeof(lenn)) < 0) {
 482                                         fprintf(stderr, "\nE: could not read export name length from server\n");
 483                                         exit(EXIT_FAILURE);
 484                                 }
 485                                 lenn=ntohl(lenn);
 486                                 if (lenn >= BUF_SIZE) {
 487                                         fprintf(stderr, "\nE: export name on server too long\n");
 488                                         exit(EXIT_FAILURE);
 489                                 }
 490                                 if(read(sock, buf, lenn) < 0) {
 491                                         fprintf(stderr, "\nE: could not read export name from server\n");
 492                                         exit(EXIT_FAILURE);
 493                                 }
 494                                 buf[lenn] = 0;
 495                                 printf("%s", buf);
 496                                 len -= lenn;
 497                                 len -= sizeof(lenn);
 498                                 if(len > 0) {
 499                                         if(len >= BUF_SIZE) {
 500                                                 fprintf(stderr, "\nE: export description read buffer overflow\n");
 501                                                 exit(EXIT_FAILURE);
 502                                         }
 503                                         if(read(sock, buf, len) < 0) {
 504                                                 fprintf(stderr, "\nE: could not read export description from server\n");
 505                                                 exit(EXIT_FAILURE);
 506                                         }
 507                                         buf[len] = 0;
 508                                         printf(": %s\n", buf);
 509                                 } else {
 510                                         printf("\n");
 511                                 }
 512                         }
 513                 }
 514         } while(reptype != NBD_REP_ACK);
 515         send_request(sock, NBD_OPT_ABORT, 0, NULL);
 516 }
 517
 518 void parse_sizes(char *buf, uint64_t *size, uint16_t *flags) {
 519         memcpy(size, buf, sizeof(*size));
 520         *size = ntohll(*size);
 521         buf += sizeof(*size);
 522         memcpy(flags, buf, sizeof(*flags));
 523         *flags = ntohs(*flags);
 524
 525         if ((*size>>12) > (uint64_t)~0UL) {
 526                 printf("size = %luMB", (unsigned long)(*size>>20));
 527                 err("Exported device is too big for me. Get 64-bit machine :-(\n");
 528         } else {
 529                 printf("size = %luMB", (unsigned long)(*size>>20));
 530         }
 531         printf("\n");
 532 }
 533
 534 void send_opt_exportname(int sock, u64 *rsize64, uint16_t *flags, bool can_opt_go, char* name, uint16_t global_flags) {
 535         send_request(sock, NBD_OPT_EXPORT_NAME, -1, name);
 536         char b[sizeof(*flags) + sizeof(*rsize64)];
 537         if(readit(sock, b, sizeof(b)) < 0 && can_opt_go) {
 538                 err("E: server does not support NBD_OPT_GO and dropped connection after sending NBD_OPT_EXPORT_NAME. Try -g.");
 539         }
 540         parse_sizes(b, rsize64, flags);
 541         if(!(global_flags & NBD_FLAG_NO_ZEROES)) {
 542                 char buf[125];
 543                 readit(sock, buf, 124);
 544         }
 545 }
 546
 547 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, char *priority, bool can_opt_go) {
 548         u64 magic;
 549         uint16_t tmp;
 550         uint16_t global_flags;
 551         char buf[256] = "\0\0\0\0\0\0\0\0\0";
 552         int sock = *sockp;
 553
 554         printf("Negotiation: ");
 555         readit(sock, buf, 8);
 556         if (strcmp(buf, INIT_PASSWD))
 557                 err("INIT_PASSWD bad");
 558         printf(".");
 559         readit(sock, &magic, sizeof(magic));
 560         magic = ntohll(magic);
 561         if (magic != opts_magic) {
 562                 if(magic == cliserv_magic) {
 563                         err("It looks like you're trying to connect to an oldstyle server. This is no longer supported since nbd 3.10.");
 564                 }
 565         }
 566         printf(".");
 567         readit(sock, &tmp, sizeof(uint16_t));
 568         global_flags = ntohs(tmp);
 569         if((needed_flags & global_flags) != needed_flags) {
 570                 /* There's currently really only one reason why this
 571                  * check could possibly fail, but we may need to change
 572                  * this error message in the future... */
 573                 fprintf(stderr, "\nE: Server does not support listing exports\n");
 574                 exit(EXIT_FAILURE);
 575         }
 576
 577         if (global_flags & NBD_FLAG_NO_ZEROES) {
 578                 client_flags |= NBD_FLAG_C_NO_ZEROES;
 579         }
 580         client_flags = htonl(client_flags);
 581         if (write(sock, &client_flags, sizeof(client_flags)) < 0)
 582                 err("Failed/2.1: %m");
 583
 584 #if HAVE_GNUTLS && !defined(NOTLS)
 585         /* TLS */
 586         if (tls) {
 587                 int plainfd[2]; // [0] is used by the proxy, [1] is used by NBD
 588                 tlssession_t *s = NULL;
 589                 int ret;
 590                 uint32_t tmp32;
 591                 uint64_t tmp64;
 592
 593                 send_request(sock, NBD_OPT_STARTTLS, 0, NULL);
 594
 595                 if (read(sock, &tmp64, sizeof(tmp64)) < 0)
 596                         err("Could not read cliserv_magic: %m");
 597                 tmp64 = ntohll(tmp64);
 598                 if (tmp64 != NBD_OPT_REPLY_MAGIC) {
 599                         err("reply magic does not match");
 600                 }
 601                 if (read(sock, &tmp32, sizeof(tmp32)) < 0)
 602                         err("Could not read option type: %m");
 603                 tmp32 = ntohl(tmp32);
 604                 if (tmp32 != NBD_OPT_STARTTLS)
 605                         err("Reply to wrong option");
 606                 if (read(sock, &tmp32, sizeof(tmp32)) < 0)
 607                         err("Could not read option reply type: %m");
 608                 tmp32 = ntohl(tmp32);
 609                 if (tmp32 != NBD_REP_ACK) {
 610                         err("Option reply type != NBD_REP_ACK");
 611                 }
 612                 if (read(sock, &tmp32, sizeof(tmp32)) < 0) err(
 613                         "Could not read option data length: %m");
 614                 tmp32 = ntohl(tmp32);
 615                 if (tmp32 != 0) {
 616                         err("Option reply data length != 0");
 617                 }
 618                 s = tlssession_new(0,
 619                                    keyfile,
 620                                    certfile,
 621                                    cacertfile,
 622                                    tlshostname,
 623                                    priority,
 624                                    !cacertfile || !tlshostname, // insecure flag
 625 #ifdef DODBG
 626                                    1, // debug
 627 #else
 628                                    0, // debug
 629 #endif
 630                                    NULL, // quitfn
 631                                    NULL, // erroutfn
 632                                    NULL // opaque
 633                         );
 634                 if (!s)
 635                         err("Cannot establish TLS session");
 636
 637                 if (socketpair(AF_UNIX, SOCK_STREAM, 0, plainfd) < 0)
 638                         err("Cannot get socket pair");
 639
 640                 if (set_nonblocking(plainfd[0], 0) <0 ||
 641                     set_nonblocking(plainfd[1], 0) <0 ||
 642                     set_nonblocking(sock, 0) <0) {
 643                         close(plainfd[0]);
 644                         close(plainfd[1]);
 645                         err("Cannot set socket options");
 646                 }
 647
 648                 ret = fork();
 649                 if (ret < 0)
 650                         err("Could not fork");
 651                 else if (ret == 0) {
 652                         // we are the child
 653                         if (daemon(0, 0) < 0) {
 654                                 /* no one will see this */
 655                                 fprintf(stderr, "Can't detach from the terminal");
 656                                 exit(1);
 657                         }
 658                         signal (SIGPIPE, SIG_IGN);
 659                         close(plainfd[1]);
 660                         tlssession_mainloop(sock, plainfd[0], s);
 661                         close(sock);
 662                         close(plainfd[0]);
 663                         exit(0);
 664                 }
 665                 close(plainfd[0]);
 666                 close(sock);
 667                 sock = plainfd[1]; /* use the decrypted FD from now on */
 668                 *sockp = sock;
 669         }
 670 #else
 671         if (keyfile) {
 672                 err("TLS requested but support not compiled in");
 673         }
 674 #endif
 675
 676         if(do_opts & NBDC_DO_LIST) {
 677                 ask_list(sock);
 678                 exit(EXIT_SUCCESS);
 679         }
 680
 681         struct reply *rep = NULL;
 682
 683         if(!can_opt_go) {
 684                 send_opt_exportname(sock, rsize64, flags, can_opt_go, name, global_flags);
 685                 return;
 686         }
 687
 688         send_info_request(sock, NBD_OPT_GO, 0, NULL, name);
 689
 690         do {
 691                 if(rep != NULL) free(rep);
 692                 rep = read_reply(sock);
 693                 if(rep == NULL) {
 694                         err("Unable to read reply.");
 695                         exit(EXIT_FAILURE);
 696                 }
 697                 if(rep->reply_type & NBD_REP_FLAG_ERROR) {
 698                         switch(rep->reply_type) {
 699                                 case NBD_REP_ERR_UNSUP:
 700                                         /* server doesn't support NBD_OPT_GO or NBD_OPT_INFO,
 701                                          * fall back to NBD_OPT_EXPORT_NAME */
 702                                         send_opt_exportname(sock, rsize64, flags, can_opt_go, name, global_flags);
 703                                         free(rep);
 704                                         return;
 705                                 case NBD_REP_ERR_POLICY:
 706                                         if(rep->datasize > 0) {
 707                                                 char errstr[1024];
 708                                                 rep->data[rep->datasize - 1] = '\0';
 709                                                 snprintf(errstr, sizeof errstr, "Connection not allowed by server policy. Server said: %s", rep->data);
 710                                                 err(errstr);
 711                                         } else {
 712                                                 err("Connection not allowed by server policy.");
 713                                         }
 714                                         free(rep);
 715                                         exit(EXIT_FAILURE);
 716                                 default:
 717                                         if(rep->datasize > 0) {
 718                                                 char errstr[1024];
 719                                                 rep->data[rep->datasize - 1] = '\0';
 720                                                 snprintf(errstr, sizeof errstr, "Unknown error returned by server. Server said: %s", rep->data);
 721                                                 err(errstr);
 722                                         } else {
 723                                                 err("Unknown error returned by server.");
 724                                         }
 725                                         free(rep);
 726                                         exit(EXIT_FAILURE);
 727                         }
 728                 }
 729                 uint16_t info_type;
 730                 switch(rep->reply_type) {
 731                         case NBD_REP_INFO:
 732                                 memcpy(&info_type, rep->data, 2);
 733                                 info_type = htons(info_type);
 734                                 switch(info_type) {
 735                                         case NBD_INFO_EXPORT:
 736                                                 parse_sizes(rep->data + 2, rsize64, flags);
 737                                                 break;
 738                                         default:
 739                                                 // ignore these, don't need them
 740                                                 break;
 741                                 }
 742                                 break;
 743                         case NBD_REP_ACK:
 744                                 break;
 745                         default:
 746                                 err_nonfatal("Unknown reply to NBD_OPT_GO received, ignoring");
 747                 }
 748         } while(rep->reply_type != NBD_REP_ACK);
 749         free(rep);
 750 }
 751
 752 bool get_from_config(char* cfgname, char** name_ptr, char** dev_ptr, char** hostn_ptr, int* bs, int* timeout, int* persist, int* swap, int* b_unix, char**port, int* num_conns, char **certfile, char **keyfile, char **cacertfile, char **tlshostname, char **priority, bool *can_opt_go) {
 753         bool retval = false;
 754         cur_client = calloc(sizeof(CLIENT), 1);
 755         cur_client->bs = 512;
 756         cur_client->nconn = 1;
 757         cur_client->port = NBD_DEFAULT_PORT;
 758         yyin = fopen(SYSCONFDIR "/nbdtab", "r");
 759         yyout = fopen("/dev/null", "w");
 760
 761         if(!strncmp(cfgname, "/dev/", 5)) {
 762                 cfgname += 5;
 763         }
 764         cur_client->dev = cfgname;
 765         if(yyin == NULL) {
 766                 fprintf(stderr, "while opening %s: ", SYSCONFDIR "/nbdtab");
 767                 perror("could not open config file");
 768                 goto out;
 769         }
 770         yyparse();
 771
 772         if(!found_config || parse_error) {
 773                 goto out;
 774         }
 775         *name_ptr = cur_client->name;
 776         *dev_ptr = calloc(strlen(cur_client->dev) + 6, 1);
 777         if (!*dev_ptr) {
 778                 goto out;
 779         }
 780         snprintf(*dev_ptr, strlen(cur_client->dev) + 6, "/dev/%s", cur_client->dev);
 781         *hostn_ptr = cur_client->hostn;
 782         *bs = cur_client->bs;
 783         *timeout = cur_client->timeout;
 784         *persist = cur_client->persist ? 1 : 0;
 785         *swap = cur_client->swap ? 1 : 0;
 786         *b_unix = cur_client->b_unix ? 1 : 0;
 787         *port = cur_client->port;
 788         *num_conns = cur_client->nconn;
 789         *certfile = cur_client->cert;
 790         *keyfile = cur_client->key;
 791         *cacertfile = cur_client->cacert;
 792         *tlshostname = cur_client->tlshostn;
 793         *priority = cur_client->priority;
 794         *can_opt_go = !(cur_client->no_optgo);
 795
 796         retval = true;
 797 out:
 798         if(yyin != NULL) {
 799                 fclose(yyin);
 800         }
 801         if(yyout != NULL) {
 802                 fclose(yyout);
 803         }
 804         return retval;
 805 }
 806
 807 void setsizes(int nbd, u64 size64, int blocksize, u32 flags) {
 808         unsigned long size;
 809         int read_only = (flags & NBD_FLAG_READ_ONLY) ? 1 : 0;
 810
 811         if (size64>>12 > (uint64_t)~0UL)
 812                 err("Device too large.\n");
 813         else {
 814                 int tmp_blocksize = 4096;
 815                 if (size64 / (u64)blocksize <= (uint64_t)~0UL)
 816                         tmp_blocksize = blocksize;
 817                 if (ioctl(nbd, NBD_SET_BLKSIZE, tmp_blocksize) < 0) {
 818                         fprintf(stderr, "Failed to set blocksize %d\n",
 819                                 tmp_blocksize);
 820                         err("Ioctl/1.1a failed: %m\n");
 821                 }
 822                 size = (unsigned long)(size64 / (u64)tmp_blocksize);
 823                 if (ioctl(nbd, NBD_SET_SIZE_BLOCKS, size) < 0)
 824                         err("Ioctl/1.1b failed: %m\n");
 825                 if (tmp_blocksize != blocksize) {
 826                         if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0) {
 827                                 fprintf(stderr, "Failed to set blocksize %d\n",
 828                                         blocksize);
 829                                 err("Ioctl/1.1c failed: %m\n");
 830                         }
 831                 }
 832                 fprintf(stderr, "bs=%d, sz=%" PRIu64 " bytes\n", blocksize, (u64)tmp_blocksize * size);
 833         }
 834
 835         ioctl(nbd, NBD_CLEAR_SOCK);
 836
 837         /* ignore error as kernel may not support */
 838         ioctl(nbd, NBD_SET_FLAGS, (unsigned long) flags);
 839
 840         if (ioctl(nbd, BLKROSET, (unsigned long) &read_only) < 0)
 841                 err("Unable to set read-only attribute for device");
 842 }
 843
 844 void set_timeout(int nbd, int timeout) {
 845         if (timeout) {
 846                 if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)timeout) < 0)
 847                         err("Ioctl NBD_SET_TIMEOUT failed: %m\n");
 848                 fprintf(stderr, "timeout=%d\n", timeout);
 849         }
 850 }
 851
 852 void finish_sock(int sock, int nbd, int swap) {
 853         if (ioctl(nbd, NBD_SET_SOCK, sock) < 0) {
 854                 if (errno == EBUSY)
 855                         err("Kernel doesn't support multiple connections\n");
 856                 else
 857                         err("Ioctl NBD_SET_SOCK failed: %m\n");
 858         }
 859
 860 #ifndef __ANDROID__
 861         if (swap)
 862                 mlockall(MCL_CURRENT | MCL_FUTURE);
 863 #endif
 864 }
 865
 866 static int
 867 oom_adjust(const char *file, const char *value)
 868 {
 869         int fd, rc;
 870         size_t len;
 871
 872         fd = open(file, O_WRONLY);
 873         if (fd < 0)
 874                 return -1;
 875         len = strlen(value);
 876         rc = write(fd, value, len) != (ssize_t) len;
 877         close(fd);
 878         return rc ? -1 : 0;
 879 }
 880
 881 void usage(char* errmsg, ...) {
 882         if(errmsg) {
 883                 char tmp[256];
 884                 va_list ap;
 885                 va_start(ap, errmsg);
 886                 snprintf(tmp, 256, "ERROR: %s\n\n", errmsg);
 887                 vfprintf(stderr, tmp, ap);
 888                 va_end(ap);
 889         } else {
 890                 fprintf(stderr, "%s version %s\n", PROG_NAME, PACKAGE_VERSION);
 891         }
 892 #if HAVE_NETLINK
 893         fprintf(stderr, "Usage: nbd-client -name|-N name host [port] nbd_device\n\t[-block-size|-b block size] [-timeout|-t timeout] [-swap|-s]\n\t[-persist|-p] [-nofork|-n] [-systemd-mark|-m] [-nonetlink|-L]\n\t[-readonly|-R] [-size|-B bytes] [-preinit|-P]\n");
 894 #else
 895         fprintf(stderr, "Usage: nbd-client -name|-N name host [port] nbd_device\n\t[-block-size|-b block size] [-timeout|-t timeout] [-swap|-s]\n\t[-persist|-p] [-nofork|-n] [-systemd-mark|-m]\n\t[-readonly|-R] [-size|-B bytes] [-preinit|-P]\n");
 896 #endif
 897         fprintf(stderr, "Or   : nbd-client -u (with same arguments as above)\n");
 898         fprintf(stderr, "Or   : nbd-client nbdX\n");
 899         fprintf(stderr, "Or   : nbd-client -d nbd_device\n");
 900         fprintf(stderr, "Or   : nbd-client -c nbd_device\n");
 901         fprintf(stderr, "Or   : nbd-client -h|--help\n");
 902         fprintf(stderr, "Or   : nbd-client -l|--list host\n");
 903         fprintf(stderr, "Or   : nbd-client -V|--version\n");
 904 #if HAVE_GNUTLS && !defined(NOTLS)
 905         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\t[-y|-priority gnutls-priority-string]\n");
 906 #endif
 907         fprintf(stderr, "Default value for blocksize is 512\n");
 908         fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
 909         fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
 910         fprintf(stderr, "blocksizes other than 1024 without patches\n");
 911         fprintf(stderr, "Default value for port is 10809. Note that port must always be numeric\n");
 912         fprintf(stderr, "Bug reports and general discussion should go to %s\n", PACKAGE_BUGREPORT);
 913 }
 914
 915 void disconnect(char* device) {
 916         int nbd = open(device, O_RDWR);
 917
 918         if (nbd < 0)
 919                 err("Cannot open NBD: %m\nPlease ensure the 'nbd' module is loaded.");
 920         printf("disconnect, ");
 921         if (ioctl(nbd, NBD_DISCONNECT)<0)
 922                 err("Ioctl failed: %m\n");
 923         printf("sock, ");
 924         if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
 925                 err("Ioctl failed: %m\n");
 926         printf("done\n");
 927         close(nbd);
 928 }
 929
 930 static const char *short_opts = "-B:b:c:d:gH:hlnN:PpRSst:uVxy:"
 931 #if HAVE_NETLINK
 932         "L"
 933 #endif
 934 #if HAVE_GNUTLS
 935         "A:C:F:K:"
 936 #endif
 937         ;
 938
 939 int main(int argc, char *argv[]) {
 940         char* port=NBD_DEFAULT_PORT;
 941         int sock, nbd;
 942         int blocksize=512;
 943         char *hostname=NULL;
 944         char *nbddev=NULL;
 945         int swap=0;
 946         int cont=0;
 947         int timeout=0;
 948         int G_GNUC_UNUSED nofork=0; // if -dNOFORK
 949         pid_t main_pid;
 950         u64 size64 = 0;
 951         u64 force_size64 = 0;
 952         uint16_t flags = 0;
 953         bool force_read_only = false;
 954         bool preinit = false;
 955         int c;
 956         int nonspecial=0;
 957         int b_unix=0;
 958         char* name="";
 959         uint16_t needed_flags=0;
 960         uint32_t cflags=NBD_FLAG_C_FIXED_NEWSTYLE;
 961         uint32_t opts=0;
 962         sigset_t block, old;
 963         char *certfile = NULL;
 964         char *keyfile = NULL;
 965         char *cacertfile = NULL;
 966         char *tlshostname = NULL;
 967         char *priority = NULL;
 968         bool tls = false;
 969         struct sigaction sa;
 970         int num_connections = 1;
 971         int netlink = HAVE_NETLINK;
 972         int need_disconnect = 0;
 973         int *sockfds;
 974         struct option long_options[] = {
 975                 { "cacertfile", required_argument, NULL, 'A' },
 976                 { "block-size", required_argument, NULL, 'b' },
 977                 { "size", required_argument, NULL, 'B' },
 978                 { "check", required_argument, NULL, 'c' },
 979                 { "connections", required_argument, NULL, 'C'},
 980                 { "disconnect", required_argument, NULL, 'd' },
 981                 { "certfile", required_argument, NULL, 'F' },
 982                 { "no-optgo", no_argument, NULL, 'g' },
 983                 { "help", no_argument, NULL, 'h' },
 984                 { "tlshostname", required_argument, NULL, 'H' },
 985                 { "keyfile", required_argument, NULL, 'K' },
 986                 { "list", no_argument, NULL, 'l' },
 987 #if HAVE_NETLINK
 988                 { "nonetlink", no_argument, NULL, 'L' },
 989 #endif
 990                 { "systemd-mark", no_argument, NULL, 'm' },
 991                 { "nofork", no_argument, NULL, 'n' },
 992                 { "name", required_argument, NULL, 'N' },
 993                 { "persist", no_argument, NULL, 'p' },
 994                 { "preinit", no_argument, NULL, 'P' },
 995                 { "readonly", no_argument, NULL, 'R' },
 996                 { "swap", no_argument, NULL, 's' },
 997                 { "timeout", required_argument, NULL, 't' },
 998                 { "unix", no_argument, NULL, 'u' },
 999                 { "version", no_argument, NULL, 'V' },
1000                 { "enable-tls", no_argument, NULL, 'x' },
1001                 { "priority", required_argument, NULL, 'y' },
1002                 { 0, 0, 0, 0 },
1003         };
1004         int i;
1005         bool can_opt_go = true;
1006
1007         logging(MY_NAME);
1008
1009 #if HAVE_GNUTLS && !defined(NOTLS)
1010         tlssession_init();
1011 #endif
1012
1013         while((c=getopt_long_only(argc, argv, short_opts, long_options, NULL))>=0) {
1014                 switch(c) {
1015                 case 1:
1016                         // non-option argument
1017                         if(strchr(optarg, '=')) {
1018                                 // old-style 'bs=' or 'timeout='
1019                                 // argument
1020                                 fprintf(stderr, "WARNING: old-style command-line argument encountered. This is deprecated.\n");
1021                                 if(!strncmp(optarg, "bs=", 3)) {
1022                                         optarg+=3;
1023                                         goto blocksize;
1024                                 }
1025                                 if(!strncmp(optarg, "timeout=", 8)) {
1026                                         optarg+=8;
1027                                         goto timeout;
1028                                 }
1029                                 usage("unknown option %s encountered", optarg);
1030                                 exit(EXIT_FAILURE);
1031                         }
1032                         switch(nonspecial++) {
1033                                 case 0:
1034                                         // host
1035                                         hostname=optarg;
1036                                         break;
1037                                 case 1:
1038                                         // port
1039                                         if(!strtol(optarg, NULL, 0)) {
1040                                                 // not parseable as a number, assume it's the device
1041                                                 nbddev = optarg;
1042                                                 nonspecial++;
1043                                         } else {
1044                                                 port = optarg;
1045                                         }
1046                                         break;
1047                                 case 2:
1048                                         // device
1049                                         nbddev = optarg;
1050                                         break;
1051                                 default:
1052                                         usage("too many non-option arguments specified");
1053                                         exit(EXIT_FAILURE);
1054                         }
1055                         break;
1056                 case 'b':
1057                       blocksize:
1058                         blocksize=(int)strtol(optarg, NULL, 0);
1059                         if(blocksize == 0 || (blocksize % 512) != 0) {
1060                                 fprintf(stderr, "E: blocksize is not a multiple of 512! This is not allowed\n");
1061                                 exit(EXIT_FAILURE);
1062                         }
1063                         break;
1064                 case 'B':
1065                         force_size64=(u64)strtoull(optarg, NULL, 0);
1066                         if(force_size64 == 0) {
1067                                 fprintf(stderr, "E: Invalid size\n");
1068                                 exit(EXIT_FAILURE);
1069                         }
1070                         break;
1071                 case 'c':
1072                         return check_conn(optarg, 1);
1073                 case 'C':
1074                         num_connections = (int)strtol(optarg, NULL, 0);
1075                         break;
1076                 case 'd':
1077                         need_disconnect = 1;
1078                         nbddev = strdup(optarg);
1079                         break;
1080                 case 'g':
1081                         can_opt_go = false;
1082                         break;
1083                 case 'h':
1084                         usage(NULL);
1085                         exit(EXIT_SUCCESS);
1086                 case 'l':
1087                         needed_flags |= NBD_FLAG_FIXED_NEWSTYLE;
1088                         opts |= NBDC_DO_LIST;
1089                         nbddev="";
1090                         break;
1091 #if HAVE_NETLINK
1092                 case 'L':
1093                         netlink = 0;
1094                         break;
1095 #endif
1096                 case 'm':
1097                         argv[0][0] = '@';
1098                         break;
1099                 case 'n':
1100                         nofork=1;
1101                         break;
1102                 case 'N':
1103                         name=optarg;
1104                         break;
1105                 case 'p':
1106                         cont=1;
1107                         break;
1108                 case 'P':
1109                         preinit = true;
1110                         break;
1111                 case 'R':
1112                         force_read_only = true;
1113                         break;
1114                 case 's':
1115                         swap=1;
1116                         break;
1117                 case 't':
1118                       timeout:
1119                         timeout=strtol(optarg, NULL, 0);
1120                         break;
1121                 case 'u':
1122                         b_unix = 1;
1123                         break;
1124                 case 'V':
1125                         printf("This is %s, from %s\n", PROG_NAME, PACKAGE_STRING);
1126                         return 0;
1127 #if HAVE_GNUTLS && !defined(NOTLS)
1128                 case 'x':
1129                         tls = true;
1130                         break;
1131                 case 'F':
1132                         certfile=strdup(optarg);
1133                         break;
1134                 case 'K':
1135                         keyfile=strdup(optarg);
1136                         break;
1137                 case 'A':
1138                         cacertfile=strdup(optarg);
1139                         break;
1140                 case 'H':
1141                         tlshostname=strdup(optarg);
1142                         break;
1143                 case 'y':
1144                                     priority=strdup(optarg);
1145                                     break;
1146 #else
1147                 case 'F':
1148                 case 'K':
1149                 case 'H':
1150                 case 'A':
1151                         case 'y':
1152                         fprintf(stderr, "E: TLS support not compiled in\n");
1153                         exit(EXIT_FAILURE);
1154 #endif
1155                 default:
1156                         fprintf(stderr, "E: option eaten by 42 mice\n");
1157                         exit(EXIT_FAILURE);
1158                 }
1159         }
1160
1161         if (need_disconnect) {
1162                 if (netlink)
1163                         netlink_disconnect(nbddev);
1164                 else
1165                         disconnect(nbddev);
1166                 exit(EXIT_SUCCESS);
1167         }
1168 #ifdef __ANDROID__
1169   if (swap)
1170     err("swap option unsupported on Android because mlockall is unsupported.");
1171 #endif
1172         if(hostname) {
1173                 if((!name || !nbddev) && !(opts & NBDC_DO_LIST)) {
1174                         if(!strncmp(hostname, "nbd", 3) || !strncmp(hostname, "/dev/nbd", 8)) {
1175                                 if(!get_from_config(hostname, &name, &nbddev, &hostname, &blocksize, &timeout, &cont, &swap, &b_unix, &port, &num_connections, &certfile, &keyfile, &cacertfile, &tlshostname, &priority, &can_opt_go)) {
1176                                         usage("no valid configuration for specified device found", hostname);
1177                                         exit(EXIT_FAILURE);
1178                                 }
1179                         } else if (!netlink) {
1180                                 usage("not enough information specified, and argument didn't look like an nbd device");
1181                                 exit(EXIT_FAILURE);
1182                         }
1183                 }
1184         } else {
1185                 usage("no information specified");
1186                 exit(EXIT_FAILURE);
1187         }
1188
1189         if (keyfile && !certfile)
1190                 certfile = strdup(keyfile);
1191
1192         if (certfile != NULL || keyfile != NULL || cacertfile != NULL || tlshostname != NULL) {
1193                 tls = true;
1194         }
1195
1196         if (preinit) {
1197                 if (tls) {
1198                         fprintf(stderr, "E: preinit connection cannot be used with TLS\n");
1199                         exit(EXIT_FAILURE);
1200                 }
1201                 if (!force_size64) {
1202                         fprintf(stderr, "E: preinit connection requires specifying size\n");
1203                         exit(EXIT_FAILURE);
1204                 }
1205         }
1206
1207         if (!tlshostname && hostname && !b_unix)
1208                 tlshostname = strdup(hostname);
1209
1210         if (netlink)
1211                 nofork = 1;
1212
1213         if((force_size64 % blocksize) != 0) {
1214                 fprintf(stderr, "E: size (%" PRIu64 " bytes) is not a multiple of blocksize (%d)!\n", force_size64, blocksize);
1215                 exit(EXIT_FAILURE);
1216         }
1217
1218         if(strlen(name)==0 && !(opts & NBDC_DO_LIST)) {
1219                 printf("Warning: the oldstyle protocol is no longer supported.\nThis method now uses the newstyle protocol with a default export\n");
1220         }
1221
1222         if(!(opts & NBDC_DO_LIST) && !netlink) {
1223                 nbd = open(nbddev, O_RDWR);
1224                 if (nbd < 0)
1225                         err("Cannot open NBD: %m\nPlease ensure the 'nbd' module is loaded.");
1226         }
1227
1228         if (netlink) {
1229                 sockfds = malloc(sizeof(int) * num_connections);
1230                 if (!sockfds)
1231                         err("Cannot allocate the socket fd's array");
1232         }
1233
1234         for (i = 0; i < num_connections; i++) {
1235                 if (b_unix)
1236                         sock = openunix(hostname);
1237                 else
1238                         sock = opennet(hostname, port);
1239                 if (sock < 0)
1240                         exit(EXIT_FAILURE);
1241
1242                 if (!preinit)
1243                         negotiate(&sock, &size64, &flags, name, needed_flags, cflags, opts, certfile, keyfile, cacertfile, tlshostname, tls, priority, can_opt_go);
1244                 if (force_read_only)
1245                         flags |= NBD_FLAG_READ_ONLY;
1246                 if (force_size64)
1247                         size64 = force_size64;
1248                 if (netlink) {
1249                         sockfds[i] = sock;
1250                         continue;
1251                 }
1252
1253                 if (i == 0) {
1254                         setsizes(nbd, size64, blocksize, flags);
1255                         set_timeout(nbd, timeout);
1256                 }
1257                 finish_sock(sock, nbd, swap);
1258                 if (swap) {
1259                         if (keyfile)
1260                                 fprintf(stderr, "Warning: using swap and TLS is prone to deadlock\n");
1261                         /* try linux >= 2.6.36 interface first */
1262                         if (oom_adjust("/proc/self/oom_score_adj", "-1000")) {
1263                                 /* fall back to linux <= 2.6.35 interface */
1264                                 oom_adjust("/proc/self/oom_adj", "-17");
1265                         }
1266                 }
1267         }
1268
1269         if (netlink) {
1270                 int index = -1;
1271                 if (nbddev) {
1272                         if (sscanf(nbddev, "/dev/nbd%d", &index) != 1)
1273                                 err("Invalid nbd device target\n");
1274                 }
1275                 netlink_configure(index, sockfds, num_connections,
1276                                   size64, blocksize, flags, timeout);
1277                 return 0;
1278         }
1279         /* Go daemon */
1280
1281 #ifndef NOFORK
1282         if(!nofork) {
1283                 if (daemon(0,0) < 0)
1284                         err("Cannot detach from terminal");
1285         }
1286
1287         memset(&sa, 0, sizeof(sa));
1288         sa.sa_handler = SIG_IGN;
1289         sigaction(SIGCHLD, &sa, NULL);
1290 #endif
1291         /* For child to check its parent */
1292         main_pid = getpid();
1293         do {
1294 #ifndef NOFORK
1295
1296                 sigfillset(&block);
1297                 sigdelset(&block, SIGKILL);
1298                 sigdelset(&block, SIGTERM);
1299                 sigdelset(&block, SIGPIPE);
1300                 sigprocmask(SIG_SETMASK, &block, &old);
1301
1302                 if (!fork()) {
1303                         /* Due to a race, the kernel NBD driver cannot
1304                          * call for a reread of the partition table
1305                          * in the handling of the NBD_DO_IT ioctl().
1306                          * Therefore, this is done in the first open()
1307                          * of the device. We therefore make sure that
1308                          * the device is opened at least once after the
1309                          * connection was made. This has to be done in a
1310                          * separate process, since the NBD_DO_IT ioctl()
1311                          * does not return until the NBD device has
1312                          * disconnected.
1313                          */
1314                         struct timespec req = {
1315                                 .tv_sec = 0,
1316                                 .tv_nsec = 100000000,
1317                         };
1318                         while(check_conn(nbddev, 0)) {
1319                                 if (main_pid != getppid()) {
1320                                         /* check_conn() will not return 0 when nbd disconnected
1321                                          * and parent exited during this loop. So the child has to
1322                                          * explicitly check parent identity and exit if parent
1323                                          * exited */
1324                                         exit(0);
1325                                 }
1326                                 nanosleep(&req, NULL);
1327                         }
1328                         if(open(nbddev, O_RDONLY) < 0) {
1329                                 perror("could not open device for updating partition table");
1330                         }
1331                         exit(0);
1332                 }
1333 #endif
1334
1335                 if (ioctl(nbd, NBD_DO_IT) < 0) {
1336                         int error = errno;
1337                         fprintf(stderr, "nbd,%d: Kernel call returned: %s\n", main_pid, strerror(errno));
1338                         if(error==EBADR) {
1339                                 /* The user probably did 'nbd-client -d' on us.
1340                                  * quit */
1341                                 cont=0;
1342                         } else {
1343                                 if(cont) {
1344                                         u64 new_size;
1345                                         uint16_t new_flags;
1346
1347                                         close(sock); close(nbd);
1348                                         for (;;) {
1349                                                 fprintf(stderr, " Reconnecting\n");
1350                                                 if (b_unix)
1351                                                         sock = openunix(hostname);
1352                                                 else
1353                                                         sock = opennet(hostname, port);
1354                                                 if (sock >= 0)
1355                                                         break;
1356                                                 sleep (1);
1357                                         }
1358                                         nbd = open(nbddev, O_RDWR);
1359                                         if (nbd < 0)
1360                                                 err("Cannot open NBD: %m");
1361                                         negotiate(&sock, &new_size, &new_flags, name, needed_flags, cflags, opts, certfile, keyfile, cacertfile, tlshostname, tls, priority, can_opt_go);
1362                                         if (size64 != new_size) {
1363                                                 err("Size of the device changed. Bye");
1364                                         }
1365                                         setsizes(nbd, size64, blocksize,
1366                                                                 new_flags);
1367
1368                                         set_timeout(nbd, timeout);
1369                                         finish_sock(sock,nbd,swap);
1370                                 }
1371                         }
1372                 } else {
1373                         /* We're on 2.4. It's not clearly defined what exactly
1374                          * happened at this point. Probably best to quit, now
1375                          */
1376                         fprintf(stderr, "Kernel call returned.\n");
1377                         cont=0;
1378                 }
1379         } while(cont);
1380         printf("sock, ");
1381         ioctl(nbd, NBD_CLEAR_SOCK);
1382         printf("done\n");
1383         return 0;
1384 }