nbd-server.c

   1 /*
   2  * Network Block Device - server
   3  *
   4  * Copyright 1996-1998 Pavel Machek, distribute under GPL
   5  *  <pavel@atrey.karlin.mff.cuni.cz>
   6  * Copyright 2001-2004 Wouter Verhelst <wouter@debian.org>
   7  * Copyright 2002 Anton Altaparmakov <aia21@cam.ac.uk>
   8  *
   9  * Version 1.0 - hopefully 64-bit-clean
  10  * Version 1.1 - merging enhancements from Josh Parsons, <josh@coombs.anu.edu.au>
  11  * Version 1.2 - autodetect size of block devices, thanx to Peter T. Breuer" <ptb@it.uc3m.es>
  12  * Version 1.5 - can compile on Unix systems that don't have 64 bit integer
  13  *      type, or don't have 64 bit file offsets by defining FS_32BIT
  14  *      in compile options for nbd-server *only*. This can be done
  15  *      with make FSCHOICE=-DFS_32BIT nbd-server. (I don't have the
  16  *      original autoconf input file, or I would make it a configure
  17  *      option.) Ken Yap <ken@nlc.net.au>.
  18  * Version 1.6 - fix autodetection of block device size and really make 64 bit
  19  *      clean on 32 bit machines. Anton Altaparmakov <aia21@cam.ac.uk>
  20  * Version 2.0 - Version synchronised with client
  21  * Version 2.1 - Reap zombie client processes when they exit. Removed
  22  *      (uncommented) the _IO magic, it's no longer necessary. Wouter
  23  *      Verhelst <wouter@debian.org>
  24  * Version 2.2 - Auto switch to read-only mode (usefull for floppies).
  25  * Version 2.3 - Fixed code so that Large File Support works. This
  26  *      removes the FS_32BIT compile-time directive; define
  27  *      _FILE_OFFSET_BITS=64 and _LARGEFILE_SOURCE if you used to be
  28  *      using FS_32BIT. This will allow you to use files >2GB instead of
  29  *      having to use the -m option. Wouter Verhelst <wouter@debian.org>
  30  * Version 2.4 - Added code to keep track of children, so that we can
  31  *      properly kill them from initscripts. Add a call to daemon(),
  32  *      so that processes don't think they have to wait for us, which is
  33  *      interesting for initscripts as well. Wouter Verhelst
  34  *      <wouter@debian.org>
  35  * Version 2.5 - Bugfix release: forgot to reset child_arraysize to
  36  *      zero after fork()ing, resulting in nbd-server going berserk
  37  *      when it receives a signal with at least one child open. Wouter
  38  *      Verhelst <wouter@debian.org>
  39  * 10/10/2003 - Added socket option SO_KEEPALIVE (sf.net bug 819235);
  40  *      rectified type of mainloop::size_host (sf.net bugs 814435 and
  41  *      817385); close the PID file after writing to it, so that the
  42  *      daemon can actually be found. Wouter Verhelst
  43  *      <wouter@debian.org>
  44  * 10/10/2003 - Size of the data "size_host" was wrong and so was not
  45  *      correctly put in network endianness. Many types were corrected
  46  *      (size_t and off_t instead of int).  <vspaceg@sourceforge.net>
  47  * Version 2.6 - Some code cleanup.
  48  * Version 2.7 - Better build system.
  49  * 11/02/2004 - Doxygenified the source, modularized it a bit. Needs a
  50  *      lot more work, but this is a start. Wouter Verhelst
  51  *      <wouter@debian.org>
  52  * 16/03/2010 - Add IPv6 support.
  53  *      Kitt Tientanopajai <kitt@kitty.in.th>
  54  *      Neutron Soutmun <neo.neutron@gmail.com>
  55  *      Suriya Soutmun <darksolar@gmail.com>
  56  */
  57
  58 /* Includes LFS defines, which defines behaviours of some of the following
  59  * headers, so must come before those */
  60 #include "lfs.h"
  61
  62 #include <sys/types.h>
  63 #include <sys/socket.h>
  64 #include <sys/stat.h>
  65 #include <sys/select.h>         /* select */
  66 #include <sys/wait.h>           /* wait */
  67 #ifdef HAVE_SYS_IOCTL_H
  68 #include <sys/ioctl.h>
  69 #endif
  70 #include <sys/param.h>
  71 #ifdef HAVE_SYS_MOUNT_H
  72 #include <sys/mount.h>          /* For BLKGETSIZE */
  73 #endif
  74 #include <signal.h>             /* sigaction */
  75 #include <errno.h>
  76 #include <netinet/tcp.h>
  77 #include <netinet/in.h>
  78 #include <netdb.h>
  79 #include <syslog.h>
  80 #include <unistd.h>
  81 #include <stdio.h>
  82 #include <stdlib.h>
  83 #include <string.h>
  84 #include <fcntl.h>
  85 #include <arpa/inet.h>
  86 #include <strings.h>
  87 #include <dirent.h>
  88 #include <unistd.h>
  89 #include <getopt.h>
  90 #include <pwd.h>
  91 #include <grp.h>
  92
  93 #include <glib.h>
  94
  95 /* used in cliserv.h, so must come first */
  96 #define MY_NAME "nbd_server"
  97 #include "cliserv.h"
  98
  99 #ifdef WITH_SDP
 100 #include <sdp_inet.h>
 101 #endif
 102
 103 /** Default position of the config file */
 104 #ifndef SYSCONFDIR
 105 #define SYSCONFDIR "/etc"
 106 #endif
 107 #define CFILE SYSCONFDIR "/nbd-server/config"
 108
 109 /** Where our config file actually is */
 110 gchar* config_file_pos;
 111
 112 /** What user we're running as */
 113 gchar* runuser=NULL;
 114 /** What group we're running as */
 115 gchar* rungroup=NULL;
 116 /** whether to export using the old negotiation protocol (port-based) */
 117 gboolean do_oldstyle=FALSE;
 118
 119 /* Whether we should avoid forking */
 120 int dontfork = 0;
 121
 122 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */
 123 #ifdef ISSERVER
 124 #define msg2(a,b) syslog(a,b)
 125 #define msg3(a,b,c) syslog(a,b,c)
 126 #define msg4(a,b,c,d) syslog(a,b,c,d)
 127 #else
 128 #define msg2(a,b) g_message(b)
 129 #define msg3(a,b,c) g_message(b,c)
 130 #define msg4(a,b,c,d) g_message(b,c,d)
 131 #endif
 132
 133 /* Debugging macros */
 134 //#define DODBG
 135 #ifdef DODBG
 136 #define DEBUG( a ) printf( a )
 137 #define DEBUG2( a,b ) printf( a,b )
 138 #define DEBUG3( a,b,c ) printf( a,b,c )
 139 #define DEBUG4( a,b,c,d ) printf( a,b,c,d )
 140 #define DEBUG5( a,b,c,d,e ) printf( a,b,c,d,e )
 141 #else
 142 #define DEBUG( a )
 143 #define DEBUG2( a,b )
 144 #define DEBUG3( a,b,c )
 145 #define DEBUG4( a,b,c,d )
 146 #define DEBUG5( a,b,c,d,e )
 147 #endif
 148 #ifndef PACKAGE_VERSION
 149 #define PACKAGE_VERSION ""
 150 #endif
 151 /**
 152  * The highest value a variable of type off_t can reach. This is a signed
 153  * integer, so set all bits except for the leftmost one.
 154  **/
 155 #define OFFT_MAX ~((off_t)1<<(sizeof(off_t)*8-1))
 156 #define LINELEN 256       /**< Size of static buffer used to read the
 157                                authorization file (yuck) */
 158 #define BUFSIZE ((1024*1024)+sizeof(struct nbd_reply)) /**< Size of buffer that can hold requests */
 159 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
 160 #define F_READONLY 1      /**< flag to tell us a file is readonly */
 161 #define F_MULTIFILE 2     /**< flag to tell us a file is exported using -m */
 162 #define F_COPYONWRITE 4   /**< flag to tell us a file is exported using
 163                             copyonwrite */
 164 #define F_AUTOREADONLY 8  /**< flag to tell us a file is set to autoreadonly */
 165 #define F_SPARSE 16       /**< flag to tell us copyronwrite should use a sparse file */
 166 #define F_SDP 32          /**< flag to tell us the export should be done using the Socket Direct Protocol for RDMA */
 167 #define F_SYNC 64         /**< Whether to fsync() after a write */
 168 #define F_FLUSH 128       /**< Whether server wants FLUSH to be sent by the client */
 169 #define F_FUA 256         /**< Whether server wants FUA to be sent by the client */
 170 #define F_ROTATIONAL 512  /**< Whether server wants the client to implement the elevator algorithm */
 171 GHashTable *children;
 172 char pidfname[256]; /**< name of our PID file */
 173 char pidftemplate[256]; /**< template to be used for the filename of the PID file */
 174 char default_authname[] = SYSCONFDIR "/nbd-server/allow"; /**< default name of allow file */
 175
 176 int modernsock=0;         /**< Socket for the modern handler. Not used
 177                                if a client was only specified on the
 178                                command line; only port used if
 179                                oldstyle is set to false (and then the
 180                                command-line client isn't used, gna gna) */
 181 char* modern_listen;      /**< listenaddr value for modernsock */
 182
 183 /**
 184  * Types of virtuatlization
 185  **/
 186 typedef enum {
 187         VIRT_NONE=0,    /**< No virtualization */
 188         VIRT_IPLIT,     /**< Literal IP address as part of the filename */
 189         VIRT_IPHASH,    /**< Replacing all dots in an ip address by a / before
 190                              doing the same as in IPLIT */
 191         VIRT_CIDR,      /**< Every subnet in its own directory */
 192 } VIRT_STYLE;
 193
 194 /**
 195  * Variables associated with a server.
 196  **/
 197 typedef struct {
 198         gchar* exportname;    /**< (unprocessed) filename of the file we're exporting */
 199         off_t expected_size; /**< size of the exported file as it was told to
 200                                us through configuration */
 201         gchar* listenaddr;   /**< The IP address we're listening on */
 202         unsigned int port;   /**< port we're exporting this file at */
 203         char* authname;      /**< filename of the authorization file */
 204         int flags;           /**< flags associated with this exported file */
 205         int socket;          /**< The socket of this server. */
 206         int socket_family;   /**< family of the socket */
 207         VIRT_STYLE virtstyle;/**< The style of virtualization, if any */
 208         uint8_t cidrlen;     /**< The length of the mask when we use
 209                                   CIDR-style virtualization */
 210         gchar* prerun;       /**< command to be ran after connecting a client,
 211                                   but before starting to serve */
 212         gchar* postrun;      /**< command that will be ran after the client
 213                                   disconnects */
 214         gchar* servename;    /**< name of the export as selected by nbd-client */
 215         int max_connections; /**< maximum number of opened connections */
 216         gchar* transactionlog;/**< filename for transaction log */
 217 } SERVER;
 218
 219 /**
 220  * Variables associated with a client socket.
 221  **/
 222 typedef struct {
 223         int fhandle;      /**< file descriptor */
 224         off_t startoff;   /**< starting offset of this file */
 225 } FILE_INFO;
 226
 227 typedef struct {
 228         off_t exportsize;    /**< size of the file we're exporting */
 229         char *clientname;    /**< peer */
 230         char *exportname;    /**< (processed) filename of the file we're exporting */
 231         GArray *export;    /**< array of FILE_INFO of exported files;
 232                                array size is always 1 unless we're
 233                                doing the multiple file option */
 234         int net;             /**< The actual client socket */
 235         SERVER *server;      /**< The server this client is getting data from */
 236         char* difffilename;  /**< filename of the copy-on-write file, if any */
 237         int difffile;        /**< filedescriptor of copyonwrite file. @todo
 238                                shouldn't this be an array too? (cfr export) Or
 239                                make -m and -c mutually exclusive */
 240         u32 difffilelen;     /**< number of pages in difffile */
 241         u32 *difmap;         /**< see comment on the global difmap for this one */
 242         gboolean modern;     /**< client was negotiated using modern negotiation protocol */
 243         int transactionlogfd;/**< fd for transaction log */
 244 } CLIENT;
 245
 246 /**
 247  * Type of configuration file values
 248  **/
 249 typedef enum {
 250         PARAM_INT,              /**< This parameter is an integer */
 251         PARAM_STRING,           /**< This parameter is a string */
 252         PARAM_BOOL,             /**< This parameter is a boolean */
 253 } PARAM_TYPE;
 254
 255 /**
 256  * Configuration file values
 257  **/
 258 typedef struct {
 259         gchar *paramname;       /**< Name of the parameter, as it appears in
 260                                   the config file */
 261         gboolean required;      /**< Whether this is a required (as opposed to
 262                                   optional) parameter */
 263         PARAM_TYPE ptype;       /**< Type of the parameter. */
 264         gpointer target;        /**< Pointer to where the data of this
 265                                   parameter should be written. If ptype is
 266                                   PARAM_BOOL, the data is or'ed rather than
 267                                   overwritten. */
 268         gint flagval;           /**< Flag mask for this parameter in case ptype
 269                                   is PARAM_BOOL. */
 270 } PARAM;
 271
 272 /**
 273  * Check whether a client is allowed to connect. Works with an authorization
 274  * file which contains one line per machine, no wildcards.
 275  *
 276  * @param opts The client who's trying to connect.
 277  * @return 0 - authorization refused, 1 - OK
 278  **/
 279 int authorized_client(CLIENT *opts) {
 280         const char *ERRMSG="Invalid entry '%s' in authfile '%s', so, refusing all connections.";
 281         FILE *f ;
 282         char line[LINELEN];
 283         char *tmp;
 284         struct in_addr addr;
 285         struct in_addr client;
 286         struct in_addr cltemp;
 287         int len;
 288
 289         if ((f=fopen(opts->server->authname,"r"))==NULL) {
 290                 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
 291                      opts->server->authname,strerror(errno)) ;
 292                 return 1 ;
 293         }
 294
 295         inet_aton(opts->clientname, &client);
 296         while (fgets(line,LINELEN,f)!=NULL) {
 297                 if((tmp=index(line, '/'))) {
 298                         if(strlen(line)<=tmp-line) {
 299                                 msg4(LOG_CRIT, ERRMSG, line, opts->server->authname);
 300                                 return 0;
 301                         }
 302                         *(tmp++)=0;
 303                         if(!inet_aton(line,&addr)) {
 304                                 msg4(LOG_CRIT, ERRMSG, line, opts->server->authname);
 305                                 return 0;
 306                         }
 307                         len=strtol(tmp, NULL, 0);
 308                         addr.s_addr>>=32-len;
 309                         addr.s_addr<<=32-len;
 310                         memcpy(&cltemp,&client,sizeof(client));
 311                         cltemp.s_addr>>=32-len;
 312                         cltemp.s_addr<<=32-len;
 313                         if(addr.s_addr == cltemp.s_addr) {
 314                                 return 1;
 315                         }
 316                 }
 317                 if (strncmp(line,opts->clientname,strlen(opts->clientname))==0) {
 318                         fclose(f);
 319                         return 1;
 320                 }
 321         }
 322         fclose(f);
 323         return 0;
 324 }
 325
 326 /**
 327  * Read data from a file descriptor into a buffer
 328  *
 329  * @param f a file descriptor
 330  * @param buf a buffer
 331  * @param len the number of bytes to be read
 332  **/
 333 static inline void readit(int f, void *buf, size_t len) {
 334         ssize_t res;
 335         while (len > 0) {
 336                 DEBUG("*");
 337                 if ((res = read(f, buf, len)) <= 0) {
 338                         if(errno != EAGAIN) {
 339                                 err("Read failed: %m");
 340                         }
 341                 } else {
 342                         len -= res;
 343                         buf += res;
 344                 }
 345         }
 346 }
 347
 348 /**
 349  * Write data from a buffer into a filedescriptor
 350  *
 351  * @param f a file descriptor
 352  * @param buf a buffer containing data
 353  * @param len the number of bytes to be written
 354  **/
 355 static inline void writeit(int f, void *buf, size_t len) {
 356         ssize_t res;
 357         while (len > 0) {
 358                 DEBUG("+");
 359                 if ((res = write(f, buf, len)) <= 0)
 360                         err("Send failed: %m");
 361                 len -= res;
 362                 buf += res;
 363         }
 364 }
 365
 366 /**
 367  * Print out a message about how to use nbd-server. Split out to a separate
 368  * function so that we can call it from multiple places
 369  */
 370 void usage() {
 371         printf("This is nbd-server version " VERSION "\n");
 372         printf("Usage: [ip:|ip6@]port file_to_export [size][kKmM] [-l authorize_file] [-r] [-m] [-c] [-C configuration file] [-p PID file name] [-o section name] [-M max connections]\n"
 373                "\t-r|--read-only\t\tread only\n"
 374                "\t-m|--multi-file\t\tmultiple file\n"
 375                "\t-c|--copy-on-write\tcopy on write\n"
 376                "\t-C|--config-file\tspecify an alternate configuration file\n"
 377                "\t-l|--authorize-file\tfile with list of hosts that are allowed to\n\t\t\t\tconnect.\n"
 378                "\t-p|--pid-file\t\tspecify a filename to write our PID to\n"
 379                "\t-o|--output-config\toutput a config file section for what you\n\t\t\t\tspecified on the command line, with the\n\t\t\t\tspecified section name\n"
 380                "\t-M|--max-connections\tspecify the maximum number of opened connections\n\n"
 381                "\tif port is set to 0, stdin is used (for running from inetd)\n"
 382                "\tif file_to_export contains '%%s', it is substituted with the IP\n"
 383                "\t\taddress of the machine trying to connect\n"
 384                "\tif ip is set, it contains the local IP address on which we're listening.\n\tif not, the server will listen on all local IP addresses\n");
 385         printf("Using configuration file %s\n", CFILE);
 386 }
 387
 388 /* Dumps a config file section of the given SERVER*, and exits. */
 389 void dump_section(SERVER* serve, gchar* section_header) {
 390         printf("[%s]\n", section_header);
 391         printf("\texportname = %s\n", serve->exportname);
 392         printf("\tlistenaddr = %s\n", serve->listenaddr);
 393         printf("\tport = %d\n", serve->port);
 394         if(serve->flags & F_READONLY) {
 395                 printf("\treadonly = true\n");
 396         }
 397         if(serve->flags & F_MULTIFILE) {
 398                 printf("\tmultifile = true\n");
 399         }
 400         if(serve->flags & F_COPYONWRITE) {
 401                 printf("\tcopyonwrite = true\n");
 402         }
 403         if(serve->expected_size) {
 404                 printf("\tfilesize = %lld\n", (long long int)serve->expected_size);
 405         }
 406         if(serve->authname) {
 407                 printf("\tauthfile = %s\n", serve->authname);
 408         }
 409         exit(EXIT_SUCCESS);
 410 }
 411
 412 /**
 413  * Parse the command line.
 414  *
 415  * @param argc the argc argument to main()
 416  * @param argv the argv argument to main()
 417  **/
 418 SERVER* cmdline(int argc, char *argv[]) {
 419         int i=0;
 420         int nonspecial=0;
 421         int c;
 422         struct option long_options[] = {
 423                 {"read-only", no_argument, NULL, 'r'},
 424                 {"multi-file", no_argument, NULL, 'm'},
 425                 {"copy-on-write", no_argument, NULL, 'c'},
 426                 {"dont-fork", no_argument, NULL, 'd'},
 427                 {"authorize-file", required_argument, NULL, 'l'},
 428                 {"config-file", required_argument, NULL, 'C'},
 429                 {"pid-file", required_argument, NULL, 'p'},
 430                 {"output-config", required_argument, NULL, 'o'},
 431                 {"max-connection", required_argument, NULL, 'M'},
 432                 {0,0,0,0}
 433         };
 434         SERVER *serve;
 435         off_t es;
 436         size_t last;
 437         char suffix;
 438         gboolean do_output=FALSE;
 439         gchar* section_header="";
 440         gchar** addr_port;
 441
 442         if(argc==1) {
 443                 return NULL;
 444         }
 445         serve=g_new0(SERVER, 1);
 446         serve->authname = g_strdup(default_authname);
 447         serve->virtstyle=VIRT_IPLIT;
 448         while((c=getopt_long(argc, argv, "-C:cdl:mo:rp:M:", long_options, &i))>=0) {
 449                 switch (c) {
 450                 case 1:
 451                         /* non-option argument */
 452                         switch(nonspecial++) {
 453                         case 0:
 454                                 if(strchr(optarg, ':') == strrchr(optarg, ':')) {
 455                                         addr_port=g_strsplit(optarg, ":", 2);
 456
 457                                         /* Check for "@" - maybe user using this separator
 458                                                  for IPv4 address */
 459                                         if(!addr_port[1]) {
 460                                                 g_strfreev(addr_port);
 461                                                 addr_port=g_strsplit(optarg, "@", 2);
 462                                         }
 463                                 } else {
 464                                         addr_port=g_strsplit(optarg, "@", 2);
 465                                 }
 466
 467                                 if(addr_port[1]) {
 468                                         serve->port=strtol(addr_port[1], NULL, 0);
 469                                         serve->listenaddr=g_strdup(addr_port[0]);
 470                                 } else {
 471                                         serve->listenaddr=NULL;
 472                                         serve->port=strtol(addr_port[0], NULL, 0);
 473                                 }
 474                                 g_strfreev(addr_port);
 475                                 break;
 476                         case 1:
 477                                 serve->exportname = g_strdup(optarg);
 478                                 if(serve->exportname[0] != '/') {
 479                                         fprintf(stderr, "E: The to be exported file needs to be an absolute filename!\n");
 480                                         exit(EXIT_FAILURE);
 481                                 }
 482                                 break;
 483                         case 2:
 484                                 last=strlen(optarg)-1;
 485                                 suffix=optarg[last];
 486                                 if (suffix == 'k' || suffix == 'K' ||
 487                                     suffix == 'm' || suffix == 'M')
 488                                         optarg[last] = '\0';
 489                                 es = (off_t)atoll(optarg);
 490                                 switch (suffix) {
 491                                         case 'm':
 492                                         case 'M':  es <<= 10;
 493                                         case 'k':
 494                                         case 'K':  es <<= 10;
 495                                         default :  break;
 496                                 }
 497                                 serve->expected_size = es;
 498                                 break;
 499                         }
 500                         break;
 501                 case 'r':
 502                         serve->flags |= F_READONLY;
 503                         break;
 504                 case 'm':
 505                         serve->flags |= F_MULTIFILE;
 506                         break;
 507                 case 'o':
 508                         do_output = TRUE;
 509                         section_header = g_strdup(optarg);
 510                         break;
 511                 case 'p':
 512                         strncpy(pidftemplate, optarg, 256);
 513                         break;
 514                 case 'c':
 515                         serve->flags |=F_COPYONWRITE;
 516                         break;
 517                 case 'd':
 518                         dontfork = 1;
 519                         break;
 520                 case 'C':
 521                         g_free(config_file_pos);
 522                         config_file_pos=g_strdup(optarg);
 523                         break;
 524                 case 'l':
 525                         g_free(serve->authname);
 526                         serve->authname=g_strdup(optarg);
 527                         break;
 528                 case 'M':
 529                         serve->max_connections = strtol(optarg, NULL, 0);
 530                         break;
 531                 default:
 532                         usage();
 533                         exit(EXIT_FAILURE);
 534                         break;
 535                 }
 536         }
 537         /* What's left: the port to export, the name of the to be exported
 538          * file, and, optionally, the size of the file, in that order. */
 539         if(nonspecial<2) {
 540                 g_free(serve);
 541                 serve=NULL;
 542         } else {
 543                 do_oldstyle = TRUE;
 544         }
 545         if(do_output) {
 546                 if(!serve) {
 547                         g_critical("Need a complete configuration on the command line to output a config file section!");
 548                         exit(EXIT_FAILURE);
 549                 }
 550                 dump_section(serve, section_header);
 551         }
 552         return serve;
 553 }
 554
 555 /**
 556  * Error codes for config file parsing
 557  **/
 558 typedef enum {
 559         CFILE_NOTFOUND,         /**< The configuration file is not found */
 560         CFILE_MISSING_GENERIC,  /**< The (required) group "generic" is missing */
 561         CFILE_KEY_MISSING,      /**< A (required) key is missing */
 562         CFILE_VALUE_INVALID,    /**< A value is syntactically invalid */
 563         CFILE_VALUE_UNSUPPORTED,/**< A value is not supported in this build */
 564         CFILE_PROGERR,          /**< Programmer error */
 565         CFILE_NO_EXPORTS,       /**< A config file was specified that does not
 566                                      define any exports */
 567         CFILE_INCORRECT_PORT,   /**< The reserved port was specified for an
 568                                      old-style export. */
 569 } CFILE_ERRORS;
 570
 571 /**
 572  * Remove a SERVER from memory. Used from the hash table
 573  **/
 574 void remove_server(gpointer s) {
 575         SERVER *server;
 576
 577         server=(SERVER*)s;
 578         g_free(server->exportname);
 579         if(server->authname)
 580                 g_free(server->authname);
 581         if(server->listenaddr)
 582                 g_free(server->listenaddr);
 583         if(server->prerun)
 584                 g_free(server->prerun);
 585         if(server->postrun)
 586                 g_free(server->postrun);
 587         if(server->transactionlog)
 588                 g_free(server->transactionlog);
 589         g_free(server);
 590 }
 591
 592 /**
 593  * duplicate server
 594  * @param s the old server we want to duplicate
 595  * @return new duplicated server
 596  **/
 597 SERVER* dup_serve(SERVER *s) {
 598         SERVER *serve = NULL;
 599
 600         serve=g_new0(SERVER, 1);
 601         if(serve == NULL)
 602                 return NULL;
 603
 604         if(s->exportname)
 605                 serve->exportname = g_strdup(s->exportname);
 606
 607         serve->expected_size = s->expected_size;
 608
 609         if(s->listenaddr)
 610                 serve->listenaddr = g_strdup(s->listenaddr);
 611
 612         serve->port = s->port;
 613
 614         if(s->authname)
 615                 serve->authname = strdup(s->authname);
 616
 617         serve->flags = s->flags;
 618         serve->socket = s->socket;
 619         serve->socket_family = s->socket_family;
 620         serve->virtstyle = s->virtstyle;
 621         serve->cidrlen = s->cidrlen;
 622
 623         if(s->prerun)
 624                 serve->prerun = g_strdup(s->prerun);
 625
 626         if(s->postrun)
 627                 serve->postrun = g_strdup(s->postrun);
 628
 629         if(s->transactionlog)
 630                 serve->transactionlog = g_strdup(s->transactionlog);
 631
 632         if(s->servename)
 633                 serve->servename = g_strdup(s->servename);
 634
 635         serve->max_connections = s->max_connections;
 636
 637         return serve;
 638 }
 639
 640 /**
 641  * append new server to array
 642  * @param s server
 643  * @param a server array
 644  * @return 0 success, -1 error
 645  */
 646 int append_serve(SERVER *s, GArray *a) {
 647         SERVER *ns = NULL;
 648         struct addrinfo hints;
 649         struct addrinfo *ai = NULL;
 650         struct addrinfo *rp = NULL;
 651         char   host[NI_MAXHOST];
 652         gchar  *port = NULL;
 653         int e;
 654         int ret;
 655
 656         if(!s) {
 657                 err("Invalid parsing server");
 658                 return -1;
 659         }
 660
 661         port = g_strdup_printf("%d", s->port);
 662
 663         memset(&hints,'\0',sizeof(hints));
 664         hints.ai_family = AF_UNSPEC;
 665         hints.ai_socktype = SOCK_STREAM;
 666         hints.ai_flags = AI_ADDRCONFIG | AI_PASSIVE;
 667         hints.ai_protocol = IPPROTO_TCP;
 668
 669         e = getaddrinfo(s->listenaddr, port, &hints, &ai);
 670
 671         if (port)
 672                 g_free(port);
 673
 674         if(e == 0) {
 675                 for (rp = ai; rp != NULL; rp = rp->ai_next) {
 676                         e = getnameinfo(rp->ai_addr, rp->ai_addrlen, host, sizeof(host), NULL, 0, NI_NUMERICHOST);
 677
 678                         if (e != 0) { // error
 679                                 fprintf(stderr, "getnameinfo: %s\n", gai_strerror(e));
 680                                 continue;
 681                         }
 682
 683                         // duplicate server and set listenaddr to resolved IP address
 684                         ns = dup_serve (s);
 685                         if (ns) {
 686                                 ns->listenaddr = g_strdup(host);
 687                                 ns->socket_family = rp->ai_family;
 688                                 g_array_append_val(a, *ns);
 689                                 free(ns);
 690                                 ns = NULL;
 691                         }
 692                 }
 693
 694                 ret = 0;
 695         } else {
 696                 fprintf(stderr, "getaddrinfo failed on listen host/address: %s (%s)\n", s->listenaddr ? s->listenaddr : "any", gai_strerror(e));
 697                 ret = -1;
 698         }
 699
 700         if (ai)
 701                 freeaddrinfo(ai);
 702
 703         return ret;
 704 }
 705
 706 /**
 707  * Parse the config file.
 708  *
 709  * @param f the name of the config file
 710  * @param e a GError. @see CFILE_ERRORS for what error values this function can
 711  *      return.
 712  * @return a Array of SERVER* pointers, If the config file is empty or does not
 713  *      exist, returns an empty GHashTable; if the config file contains an
 714  *      error, returns NULL, and e is set appropriately
 715  **/
 716 GArray* parse_cfile(gchar* f, GError** e) {
 717         const char* DEFAULT_ERROR = "Could not parse %s in group %s: %s";
 718         const char* MISSING_REQUIRED_ERROR = "Could not find required value %s in group %s: %s";
 719         SERVER s;
 720         gchar *virtstyle=NULL;
 721         PARAM lp[] = {
 722                 { "exportname", TRUE,   PARAM_STRING,   &(s.exportname),        0 },
 723                 { "port",       TRUE,   PARAM_INT,      &(s.port),              0 },
 724                 { "authfile",   FALSE,  PARAM_STRING,   &(s.authname),          0 },
 725                 { "filesize",   FALSE,  PARAM_INT,      &(s.expected_size),     0 },
 726                 { "virtstyle",  FALSE,  PARAM_STRING,   &(virtstyle),           0 },
 727                 { "prerun",     FALSE,  PARAM_STRING,   &(s.prerun),            0 },
 728                 { "postrun",    FALSE,  PARAM_STRING,   &(s.postrun),           0 },
 729                 { "transactionlog", FALSE, PARAM_STRING, &(s.transactionlog),   0 },
 730                 { "readonly",   FALSE,  PARAM_BOOL,     &(s.flags),             F_READONLY },
 731                 { "multifile",  FALSE,  PARAM_BOOL,     &(s.flags),             F_MULTIFILE },
 732                 { "copyonwrite", FALSE, PARAM_BOOL,     &(s.flags),             F_COPYONWRITE },
 733                 { "sparse_cow", FALSE,  PARAM_BOOL,     &(s.flags),             F_SPARSE },
 734                 { "sdp",        FALSE,  PARAM_BOOL,     &(s.flags),             F_SDP },
 735                 { "sync",       FALSE,  PARAM_BOOL,     &(s.flags),             F_SYNC },
 736                 { "flush",      FALSE,  PARAM_BOOL,     &(s.flags),             F_FLUSH },
 737                 { "fua",        FALSE,  PARAM_BOOL,     &(s.flags),             F_FUA },
 738                 { "rotational", FALSE,  PARAM_BOOL,     &(s.flags),             F_ROTATIONAL },
 739                 { "listenaddr", FALSE,  PARAM_STRING,   &(s.listenaddr),        0 },
 740                 { "maxconnections", FALSE, PARAM_INT,   &(s.max_connections),   0 },
 741         };
 742         const int lp_size=sizeof(lp)/sizeof(PARAM);
 743         PARAM gp[] = {
 744                 { "user",       FALSE, PARAM_STRING,    &runuser,       0 },
 745                 { "group",      FALSE, PARAM_STRING,    &rungroup,      0 },
 746                 { "oldstyle",   FALSE, PARAM_BOOL,      &do_oldstyle,   1 },
 747                 { "listenaddr", FALSE, PARAM_STRING,    &modern_listen, 0 },
 748         };
 749         PARAM* p=gp;
 750         int p_size=sizeof(gp)/sizeof(PARAM);
 751         GKeyFile *cfile;
 752         GError *err = NULL;
 753         const char *err_msg=NULL;
 754         GQuark errdomain;
 755         GArray *retval=NULL;
 756         gchar **groups;
 757         gboolean value;
 758         gchar* startgroup;
 759         gint i;
 760         gint j;
 761
 762         errdomain = g_quark_from_string("parse_cfile");
 763         cfile = g_key_file_new();
 764         retval = g_array_new(FALSE, TRUE, sizeof(SERVER));
 765         if(!g_key_file_load_from_file(cfile, f, G_KEY_FILE_KEEP_COMMENTS |
 766                         G_KEY_FILE_KEEP_TRANSLATIONS, &err)) {
 767                 g_set_error(e, errdomain, CFILE_NOTFOUND, "Could not open config file %s.", f);
 768                 g_key_file_free(cfile);
 769                 return retval;
 770         }
 771         startgroup = g_key_file_get_start_group(cfile);
 772         if(!startgroup || strcmp(startgroup, "generic")) {
 773                 g_set_error(e, errdomain, CFILE_MISSING_GENERIC, "Config file does not contain the [generic] group!");
 774                 g_key_file_free(cfile);
 775                 return NULL;
 776         }
 777         groups = g_key_file_get_groups(cfile, NULL);
 778         for(i=0;groups[i];i++) {
 779                 memset(&s, '\0', sizeof(SERVER));
 780
 781                 /* After the [generic] group, start parsing exports */
 782                 if(i==1) {
 783                         p=lp;
 784                         p_size=lp_size;
 785                 }
 786                 for(j=0;j<p_size;j++) {
 787                         g_assert(p[j].target != NULL);
 788                         g_assert(p[j].ptype==PARAM_INT||p[j].ptype==PARAM_STRING||p[j].ptype==PARAM_BOOL);
 789                         switch(p[j].ptype) {
 790                                 case PARAM_INT:
 791                                         *((gint*)p[j].target) =
 792                                                 g_key_file_get_integer(cfile,
 793                                                                 groups[i],
 794                                                                 p[j].paramname,
 795                                                                 &err);
 796                                         break;
 797                                 case PARAM_STRING:
 798                                         *((gchar**)p[j].target) =
 799                                                 g_key_file_get_string(cfile,
 800                                                                 groups[i],
 801                                                                 p[j].paramname,
 802                                                                 &err);
 803                                         break;
 804                                 case PARAM_BOOL:
 805                                         value = g_key_file_get_boolean(cfile,
 806                                                         groups[i],
 807                                                         p[j].paramname, &err);
 808                                         if(!err) {
 809                                                 if(value) {
 810                                                         *((gint*)p[j].target) |= p[j].flagval;
 811                                                 } else {
 812                                                         *((gint*)p[j].target) &= ~(p[j].flagval);
 813                                                 }
 814                                         }
 815                                         break;
 816                         }
 817                         if(!strcmp(p[j].paramname, "port") && !strcmp(p[j].target, NBD_DEFAULT_PORT)) {
 818                                 g_set_error(e, errdomain, CFILE_INCORRECT_PORT, "Config file specifies default port for oldstyle export");
 819                                 g_key_file_free(cfile);
 820                                 return NULL;
 821                         }
 822                         if(err) {
 823                                 if(err->code == G_KEY_FILE_ERROR_KEY_NOT_FOUND) {
 824                                         if(!p[j].required) {
 825                                                 /* Ignore not-found error for optional values */
 826                                                 g_clear_error(&err);
 827                                                 continue;
 828                                         } else {
 829                                                 err_msg = MISSING_REQUIRED_ERROR;
 830                                         }
 831                                 } else {
 832                                         err_msg = DEFAULT_ERROR;
 833                                 }
 834                                 g_set_error(e, errdomain, CFILE_VALUE_INVALID, err_msg, p[j].paramname, groups[i], err->message);
 835                                 g_array_free(retval, TRUE);
 836                                 g_error_free(err);
 837                                 g_key_file_free(cfile);
 838                                 return NULL;
 839                         }
 840                 }
 841                 if(virtstyle) {
 842                         if(!strncmp(virtstyle, "none", 4)) {
 843                                 s.virtstyle=VIRT_NONE;
 844                         } else if(!strncmp(virtstyle, "ipliteral", 9)) {
 845                                 s.virtstyle=VIRT_IPLIT;
 846                         } else if(!strncmp(virtstyle, "iphash", 6)) {
 847                                 s.virtstyle=VIRT_IPHASH;
 848                         } else if(!strncmp(virtstyle, "cidrhash", 8)) {
 849                                 s.virtstyle=VIRT_CIDR;
 850                                 if(strlen(virtstyle)<10) {
 851                                         g_set_error(e, errdomain, CFILE_VALUE_INVALID, "Invalid value %s for parameter virtstyle in group %s: missing length", virtstyle, groups[i]);
 852                                         g_array_free(retval, TRUE);
 853                                         g_key_file_free(cfile);
 854                                         return NULL;
 855                                 }
 856                                 s.cidrlen=strtol(virtstyle+8, NULL, 0);
 857                         } else {
 858                                 g_set_error(e, errdomain, CFILE_VALUE_INVALID, "Invalid value %s for parameter virtstyle in group %s", virtstyle, groups[i]);
 859                                 g_array_free(retval, TRUE);
 860                                 g_key_file_free(cfile);
 861                                 return NULL;
 862                         }
 863                         if(s.port && !do_oldstyle) {
 864                                 g_warning("A port was specified, but oldstyle exports were not requested. This may not do what you expect.");
 865                                 g_warning("Please read 'man 5 nbd-server' and search for oldstyle for more info");
 866                         }
 867                 } else {
 868                         s.virtstyle=VIRT_IPLIT;
 869                 }
 870                 /* Don't need to free this, it's not our string */
 871                 virtstyle=NULL;
 872                 /* Don't append values for the [generic] group */
 873                 if(i>0) {
 874                         s.socket_family = AF_UNSPEC;
 875                         s.servename = groups[i];
 876
 877                         append_serve(&s, retval);
 878                 } else {
 879                         if(!do_oldstyle) {
 880                                 lp[1].required = 0;
 881                         }
 882                 }
 883 #ifndef WITH_SDP
 884                 if(s.flags & F_SDP) {
 885                         g_set_error(e, errdomain, CFILE_VALUE_UNSUPPORTED, "This nbd-server was built without support for SDP, yet group %s uses it", groups[i]);
 886                         g_array_free(retval, TRUE);
 887                         g_key_file_free(cfile);
 888                         return NULL;
 889                 }
 890 #endif
 891         }
 892         if(i==1) {
 893                 g_set_error(e, errdomain, CFILE_NO_EXPORTS, "The config file does not specify any exports");
 894         }
 895         g_key_file_free(cfile);
 896         return retval;
 897 }
 898
 899 /**
 900  * Signal handler for SIGCHLD
 901  * @param s the signal we're handling (must be SIGCHLD, or something
 902  * is severely wrong)
 903  **/
 904 void sigchld_handler(int s) {
 905         int status;
 906         int* i;
 907         pid_t pid;
 908
 909         while((pid=waitpid(-1, &status, WNOHANG)) > 0) {
 910                 if(WIFEXITED(status)) {
 911                         msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status));
 912                 }
 913                 i=g_hash_table_lookup(children, &pid);
 914                 if(!i) {
 915                         msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld", (long)pid);
 916                 } else {
 917                         DEBUG2("Removing %d from the list of children", pid);
 918                         g_hash_table_remove(children, &pid);
 919                 }
 920         }
 921 }
 922
 923 /**
 924  * Kill a child. Called from sigterm_handler::g_hash_table_foreach.
 925  *
 926  * @param key the key
 927  * @param value the value corresponding to the above key
 928  * @param user_data a pointer which we always set to 1, so that we know what
 929  * will happen next.
 930  **/
 931 void killchild(gpointer key, gpointer value, gpointer user_data) {
 932         pid_t *pid=value;
 933         int *parent=user_data;
 934
 935         kill(*pid, SIGTERM);
 936         *parent=1;
 937 }
 938
 939 /**
 940  * Handle SIGTERM and dispatch it to our children
 941  * @param s the signal we're handling (must be SIGTERM, or something
 942  * is severely wrong).
 943  **/
 944 void sigterm_handler(int s) {
 945         int parent=0;
 946
 947         g_hash_table_foreach(children, killchild, &parent);
 948
 949         if(parent) {
 950                 unlink(pidfname);
 951         }
 952
 953         exit(EXIT_SUCCESS);
 954 }
 955
 956 /**
 957  * Detect the size of a file.
 958  *
 959  * @param fhandle An open filedescriptor
 960  * @return the size of the file, or OFFT_MAX if detection was
 961  * impossible.
 962  **/
 963 off_t size_autodetect(int fhandle) {
 964         off_t es;
 965         u64 bytes;
 966         struct stat stat_buf;
 967         int error;
 968
 969 #ifdef HAVE_SYS_MOUNT_H
 970 #ifdef HAVE_SYS_IOCTL_H
 971 #ifdef BLKGETSIZE64
 972         DEBUG("looking for export size with ioctl BLKGETSIZE64\n");
 973         if (!ioctl(fhandle, BLKGETSIZE64, &bytes) && bytes) {
 974                 return (off_t)bytes;
 975         }
 976 #endif /* BLKGETSIZE64 */
 977 #endif /* HAVE_SYS_IOCTL_H */
 978 #endif /* HAVE_SYS_MOUNT_H */
 979
 980         DEBUG("looking for fhandle size with fstat\n");
 981         stat_buf.st_size = 0;
 982         error = fstat(fhandle, &stat_buf);
 983         if (!error) {
 984                 if(stat_buf.st_size > 0)
 985                         return (off_t)stat_buf.st_size;
 986         } else {
 987                 err("fstat failed: %m");
 988         }
 989
 990         DEBUG("looking for fhandle size with lseek SEEK_END\n");
 991         es = lseek(fhandle, (off_t)0, SEEK_END);
 992         if (es > ((off_t)0)) {
 993                 return es;
 994         } else {
 995                 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
 996         }
 997
 998         err("Could not find size of exported block device: %m");
 999         return OFFT_MAX;
1000 }
1001
1002 /**
1003  * Get the file handle and offset, given an export offset.
1004  *
1005  * @param export An array of export files
1006  * @param a The offset to get corresponding file/offset for
1007  * @param fhandle [out] File descriptor
1008  * @param foffset [out] Offset into fhandle
1009  * @param maxbytes [out] Tells how many bytes can be read/written
1010  * from fhandle starting at foffset (0 if there is no limit)
1011  * @return 0 on success, -1 on failure
1012  **/
1013 int get_filepos(GArray* export, off_t a, int* fhandle, off_t* foffset, size_t* maxbytes ) {
1014         /* Negative offset not allowed */
1015         if(a < 0)
1016                 return -1;
1017
1018         /* Binary search for last file with starting offset <= a */
1019         FILE_INFO fi;
1020         int start = 0;
1021         int end = export->len - 1;
1022         while( start <= end ) {
1023                 int mid = (start + end) / 2;
1024                 fi = g_array_index(export, FILE_INFO, mid);
1025                 if( fi.startoff < a ) {
1026                         start = mid + 1;
1027                 } else if( fi.startoff > a ) {
1028                         end = mid - 1;
1029                 } else {
1030                         start = end = mid;
1031                         break;
1032                 }
1033         }
1034
1035         /* end should never go negative, since first startoff is 0 and a >= 0 */
1036         g_assert(end >= 0);
1037
1038         fi = g_array_index(export, FILE_INFO, end);
1039         *fhandle = fi.fhandle;
1040         *foffset = a - fi.startoff;
1041         *maxbytes = 0;
1042         if( end+1 < export->len ) {
1043                 FILE_INFO fi_next = g_array_index(export, FILE_INFO, end+1);
1044                 *maxbytes = fi_next.startoff - a;
1045         }
1046
1047         return 0;
1048 }
1049
1050 /**
1051  * seek to a position in a file, with error handling.
1052  * @param handle a filedescriptor
1053  * @param a position to seek to
1054  * @todo get rid of this; lastpoint is a global variable right now, but it
1055  * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
1056  * easier.
1057  **/
1058 void myseek(int handle,off_t a) {
1059         if (lseek(handle, a, SEEK_SET) < 0) {
1060                 err("Can not seek locally!\n");
1061         }
1062 }
1063
1064 /**
1065  * Write an amount of bytes at a given offset to the right file. This
1066  * abstracts the write-side of the multiple file option.
1067  *
1068  * @param a The offset where the write should start
1069  * @param buf The buffer to write from
1070  * @param len The length of buf
1071  * @param client The client we're serving for
1072  * @return The number of bytes actually written, or -1 in case of an error
1073  **/
1074 ssize_t rawexpwrite(off_t a, char *buf, size_t len, CLIENT *client, int fua) {
1075         int fhandle;
1076         off_t foffset;
1077         size_t maxbytes;
1078         ssize_t retval;
1079
1080         if(get_filepos(client->export, a, &fhandle, &foffset, &maxbytes))
1081                 return -1;
1082         if(maxbytes && len > maxbytes)
1083                 len = maxbytes;
1084
1085         DEBUG5("(WRITE to fd %d offset %llu len %u fua %d), ", fhandle, foffset, len, fua);
1086
1087         myseek(fhandle, foffset);
1088         retval = write(fhandle, buf, len);
1089         if(client->server->flags & F_SYNC) {
1090                 fsync(fhandle);
1091         } else if (fua) {
1092 #ifdef USE_SYNC_FILE_RANGE
1093                 sync_file_range(fhandle, foffset, len,
1094                                 SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE |
1095                                 SYNC_FILE_RANGE_WAIT_AFTER);
1096 #else
1097                 fdatasync(fhandle);
1098 #endif
1099         }
1100         return retval;
1101 }
1102
1103 /**
1104  * Call rawexpwrite repeatedly until all data has been written.
1105  * @return 0 on success, nonzero on failure
1106  **/
1107 int rawexpwrite_fully(off_t a, char *buf, size_t len, CLIENT *client, int fua) {
1108         ssize_t ret=0;
1109
1110         while(len > 0 && (ret=rawexpwrite(a, buf, len, client, fua)) > 0 ) {
1111                 a += ret;
1112                 buf += ret;
1113                 len -= ret;
1114         }
1115         return (ret < 0 || len != 0);
1116 }
1117
1118 /**
1119  * Read an amount of bytes at a given offset from the right file. This
1120  * abstracts the read-side of the multiple files option.
1121  *
1122  * @param a The offset where the read should start
1123  * @param buf A buffer to read into
1124  * @param len The size of buf
1125  * @param client The client we're serving for
1126  * @return The number of bytes actually read, or -1 in case of an
1127  * error.
1128  **/
1129 ssize_t rawexpread(off_t a, char *buf, size_t len, CLIENT *client) {
1130         int fhandle;
1131         off_t foffset;
1132         size_t maxbytes;
1133
1134         if(get_filepos(client->export, a, &fhandle, &foffset, &maxbytes))
1135                 return -1;
1136         if(maxbytes && len > maxbytes)
1137                 len = maxbytes;
1138
1139         DEBUG4("(READ from fd %d offset %llu len %u), ", fhandle, foffset, len);
1140
1141         myseek(fhandle, foffset);
1142         return read(fhandle, buf, len);
1143 }
1144
1145 /**
1146  * Call rawexpread repeatedly until all data has been read.
1147  * @return 0 on success, nonzero on failure
1148  **/
1149 int rawexpread_fully(off_t a, char *buf, size_t len, CLIENT *client) {
1150         ssize_t ret=0;
1151
1152         while(len > 0 && (ret=rawexpread(a, buf, len, client)) > 0 ) {
1153                 a += ret;
1154                 buf += ret;
1155                 len -= ret;
1156         }
1157         return (ret < 0 || len != 0);
1158 }
1159
1160 /**
1161  * Read an amount of bytes at a given offset from the right file. This
1162  * abstracts the read-side of the copyonwrite stuff, and calls
1163  * rawexpread() with the right parameters to do the actual work.
1164  * @param a The offset where the read should start
1165  * @param buf A buffer to read into
1166  * @param len The size of buf
1167  * @param client The client we're going to read for
1168  * @return 0 on success, nonzero on failure
1169  **/
1170 int expread(off_t a, char *buf, size_t len, CLIENT *client) {
1171         off_t rdlen, offset;
1172         off_t mapcnt, mapl, maph, pagestart;
1173
1174         if (!(client->server->flags & F_COPYONWRITE))
1175                 return(rawexpread_fully(a, buf, len, client));
1176         DEBUG3("Asked to read %d bytes at %llu.\n", len, (unsigned long long)a);
1177
1178         mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
1179
1180         for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
1181                 pagestart=mapcnt*DIFFPAGESIZE;
1182                 offset=a-pagestart;
1183                 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
1184                         len : (size_t)DIFFPAGESIZE-offset;
1185                 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
1186                         DEBUG3("Page %llu is at %lu\n", (unsigned long long)mapcnt,
1187                                (unsigned long)(client->difmap[mapcnt]));
1188                         myseek(client->difffile, client->difmap[mapcnt]*DIFFPAGESIZE+offset);
1189                         if (read(client->difffile, buf, rdlen) != rdlen) return -1;
1190                 } else { /* the block is not there */
1191                         DEBUG2("Page %llu is not here, we read the original one\n",
1192                                (unsigned long long)mapcnt);
1193                         if(rawexpread_fully(a, buf, rdlen, client)) return -1;
1194                 }
1195                 len-=rdlen; a+=rdlen; buf+=rdlen;
1196         }
1197         return 0;
1198 }
1199
1200 /**
1201  * Write an amount of bytes at a given offset to the right file. This
1202  * abstracts the write-side of the copyonwrite option, and calls
1203  * rawexpwrite() with the right parameters to do the actual work.
1204  *
1205  * @param a The offset where the write should start
1206  * @param buf The buffer to write from
1207  * @param len The length of buf
1208  * @param client The client we're going to write for.
1209  * @return 0 on success, nonzero on failure
1210  **/
1211 int expwrite(off_t a, char *buf, size_t len, CLIENT *client, int fua) {
1212         char pagebuf[DIFFPAGESIZE];
1213         off_t mapcnt,mapl,maph;
1214         off_t wrlen,rdlen;
1215         off_t pagestart;
1216         off_t offset;
1217
1218         if (!(client->server->flags & F_COPYONWRITE))
1219                 return(rawexpwrite_fully(a, buf, len, client, fua));
1220         DEBUG3("Asked to write %d bytes at %llu.\n", len, (unsigned long long)a);
1221
1222         mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
1223
1224         for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
1225                 pagestart=mapcnt*DIFFPAGESIZE ;
1226                 offset=a-pagestart ;
1227                 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
1228                         len : (size_t)DIFFPAGESIZE-offset;
1229
1230                 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
1231                         DEBUG3("Page %llu is at %lu\n", (unsigned long long)mapcnt,
1232                                (unsigned long)(client->difmap[mapcnt])) ;
1233                         myseek(client->difffile,
1234                                         client->difmap[mapcnt]*DIFFPAGESIZE+offset);
1235                         if (write(client->difffile, buf, wrlen) != wrlen) return -1 ;
1236                 } else { /* the block is not there */
1237                         myseek(client->difffile,client->difffilelen*DIFFPAGESIZE) ;
1238                         client->difmap[mapcnt]=(client->server->flags&F_SPARSE)?mapcnt:client->difffilelen++;
1239                         DEBUG3("Page %llu is not here, we put it at %lu\n",
1240                                (unsigned long long)mapcnt,
1241                                (unsigned long)(client->difmap[mapcnt]));
1242                         rdlen=DIFFPAGESIZE ;
1243                         if (rawexpread_fully(pagestart, pagebuf, rdlen, client))
1244                                 return -1;
1245                         memcpy(pagebuf+offset,buf,wrlen) ;
1246                         if (write(client->difffile, pagebuf, DIFFPAGESIZE) !=
1247                                         DIFFPAGESIZE)
1248                                 return -1;
1249                 }
1250                 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
1251         }
1252         if (client->server->flags & F_SYNC) {
1253                 fsync(client->difffile);
1254         } else if (fua) {
1255                 /* open question: would it be cheaper to do multiple sync_file_ranges?
1256                    as we iterate through the above?
1257                  */
1258                 fdatasync(client->difffile);
1259         }
1260         return 0;
1261 }
1262
1263 int expflush(CLIENT *client) {
1264         int fhandle;
1265         off_t foffset;
1266         size_t maxbytes;
1267         gint i;
1268
1269         if (client->server->flags & F_COPYONWRITE) {
1270                 return fsync(client->difffile);
1271         }
1272
1273         for (i = 0; i < client->export->len; i++) {
1274                 FILE_INFO fi = g_array_index(client->export, FILE_INFO, i);
1275                 if (fsync(fi.fhandle) < 0)
1276                         return -1;
1277         }
1278
1279         return 0;
1280 }
1281
1282 /**
1283  * Do the initial negotiation.
1284  *
1285  * @param client The client we're negotiating with.
1286  **/
1287 CLIENT* negotiate(int net, CLIENT *client, GArray* servers) {
1288         char zeros[128];
1289         uint64_t size_host;
1290         uint32_t flags = NBD_FLAG_HAS_FLAGS;
1291         uint16_t smallflags = 0;
1292         uint64_t magic;
1293
1294         memset(zeros, '\0', sizeof(zeros));
1295         if(!client || !client->modern) {
1296                 /* common */
1297                 if (write(net, INIT_PASSWD, 8) < 0) {
1298                         err_nonfatal("Negotiation failed: %m");
1299                         if(client)
1300                                 exit(EXIT_FAILURE);
1301                 }
1302                 if(!client || client->modern) {
1303                         /* modern */
1304                         magic = htonll(opts_magic);
1305                 } else {
1306                         /* oldstyle */
1307                         magic = htonll(cliserv_magic);
1308                 }
1309                 if (write(net, &magic, sizeof(magic)) < 0) {
1310                         err_nonfatal("Negotiation failed: %m");
1311                         if(client)
1312                                 exit(EXIT_FAILURE);
1313                 }
1314         }
1315         if(!client) {
1316                 /* modern */
1317                 uint32_t reserved;
1318                 uint32_t opt;
1319                 uint32_t namelen;
1320                 char* name;
1321                 int i;
1322
1323                 if(!servers)
1324                         err("programmer error");
1325                 if (write(net, &smallflags, sizeof(uint16_t)) < 0)
1326                         err("Negotiation failed: %m");
1327                 if (read(net, &reserved, sizeof(reserved)) < 0)
1328                         err("Negotiation failed: %m");
1329                 if (read(net, &magic, sizeof(magic)) < 0)
1330                         err("Negotiation failed: %m");
1331                 magic = ntohll(magic);
1332                 if(magic != opts_magic) {
1333                         close(net);
1334                         return NULL;
1335                 }
1336                 if (read(net, &opt, sizeof(opt)) < 0)
1337                         err("Negotiation failed: %m");
1338                 opt = ntohl(opt);
1339                 if(opt != NBD_OPT_EXPORT_NAME) {
1340                         close(net);
1341                         return NULL;
1342                 }
1343                 if (read(net, &namelen, sizeof(namelen)) < 0)
1344                         err("Negotiation failed: %m");
1345                 namelen = ntohl(namelen);
1346                 name = malloc(namelen+1);
1347                 name[namelen]=0;
1348                 if (read(net, name, namelen) < 0)
1349                         err("Negotiation failed: %m");
1350                 for(i=0; i<servers->len; i++) {
1351                         SERVER* serve = &(g_array_index(servers, SERVER, i));
1352                         if(!strcmp(serve->servename, name)) {
1353                                 CLIENT* client = g_new0(CLIENT, 1);
1354                                 client->server = serve;
1355                                 client->exportsize = OFFT_MAX;
1356                                 client->net = net;
1357                                 client->modern = TRUE;
1358                                 client->transactionlogfd = -1;
1359                                 free(name);
1360                                 return client;
1361                         }
1362                 }
1363                 free(name);
1364                 return NULL;
1365         }
1366         /* common */
1367         size_host = htonll((u64)(client->exportsize));
1368         if (write(net, &size_host, 8) < 0)
1369                 err("Negotiation failed: %m");
1370         if (client->server->flags & F_READONLY)
1371                 flags |= NBD_FLAG_READ_ONLY;
1372         if (client->server->flags & F_FLUSH)
1373                 flags |= NBD_FLAG_SEND_FLUSH;
1374         if (client->server->flags & F_FUA)
1375                 flags |= NBD_FLAG_SEND_FUA;
1376         if (client->server->flags & F_ROTATIONAL)
1377                 flags |= NBD_FLAG_ROTATIONAL;
1378         if (!client->modern) {
1379                 /* oldstyle */
1380                 flags = htonl(flags);
1381                 if (write(client->net, &flags, 4) < 0)
1382                         err("Negotiation failed: %m");
1383         } else {
1384                 /* modern */
1385                 smallflags = (uint16_t)(flags & ~((uint16_t)0));
1386                 smallflags = htons(smallflags);
1387                 if (write(client->net, &smallflags, sizeof(smallflags)) < 0) {
1388                         err("Negotiation failed: %m");
1389                 }
1390         }
1391         /* common */
1392         if (write(client->net, zeros, 124) < 0)
1393                 err("Negotiation failed: %m");
1394         return NULL;
1395 }
1396
1397 /** sending macro. */
1398 #define SEND(net,reply) { writeit( net, &reply, sizeof( reply )); \
1399         if (client->transactionlogfd != -1) \
1400                 writeit(client->transactionlogfd, &reply, sizeof(reply)); }
1401 /** error macro. */
1402 #define ERROR(client,reply,errcode) { reply.error = htonl(errcode); SEND(client->net,reply); reply.error = 0; }
1403 /**
1404  * Serve a file to a single client.
1405  *
1406  * @todo This beast needs to be split up in many tiny little manageable
1407  * pieces. Preferably with a chainsaw.
1408  *
1409  * @param client The client we're going to serve to.
1410  * @return when the client disconnects
1411  **/
1412 int mainloop(CLIENT *client) {
1413         struct nbd_request request;
1414         struct nbd_reply reply;
1415         gboolean go_on=TRUE;
1416 #ifdef DODBG
1417         int i = 0;
1418 #endif
1419         negotiate(client->net, client, NULL);
1420         DEBUG("Entering request loop!\n");
1421         reply.magic = htonl(NBD_REPLY_MAGIC);
1422         reply.error = 0;
1423         while (go_on) {
1424                 char buf[BUFSIZE];
1425                 char* p;
1426                 size_t len;
1427                 size_t currlen;
1428                 size_t writelen;
1429                 uint16_t command;
1430 #ifdef DODBG
1431                 i++;
1432                 printf("%d: ", i);
1433 #endif
1434                 readit(client->net, &request, sizeof(request));
1435                 if (client->transactionlogfd != -1)
1436                         writeit(client->transactionlogfd, &request, sizeof(request));
1437
1438                 request.from = ntohll(request.from);
1439                 request.type = ntohl(request.type);
1440                 command = request.type & NBD_CMD_MASK_COMMAND;
1441
1442                 if (command==NBD_CMD_DISC) {
1443                         msg2(LOG_INFO, "Disconnect request received.");
1444                         if (client->server->flags & F_COPYONWRITE) {
1445                                 if (client->difmap) g_free(client->difmap) ;
1446                                 close(client->difffile);
1447                                 unlink(client->difffilename);
1448                                 free(client->difffilename);
1449                         }
1450                         go_on=FALSE;
1451                         continue;
1452                 }
1453
1454                 len = ntohl(request.len);
1455
1456                 if (request.magic != htonl(NBD_REQUEST_MAGIC))
1457                         err("Not enough magic.");
1458                 if (len > BUFSIZE - sizeof(struct nbd_reply)) {
1459                         currlen = BUFSIZE - sizeof(struct nbd_reply);
1460                         msg2(LOG_INFO, "oversized request (this is not a problem)");
1461                 } else {
1462                         currlen = len;
1463                 }
1464 #ifdef DODBG
1465                 printf("%s from %llu (%llu) len %d, ", command ? "WRITE" :
1466                                 "READ", (unsigned long long)request.from,
1467                                 (unsigned long long)request.from / 512, len);
1468 #endif
1469                 memcpy(reply.handle, request.handle, sizeof(reply.handle));
1470
1471                 if ((command==NBD_CMD_WRITE) || (command==NBD_CMD_READ)) {
1472                         if ((request.from + len) > (OFFT_MAX)) {
1473                                 DEBUG("[Number too large!]");
1474                                 ERROR(client, reply, EINVAL);
1475                                 continue;
1476                         }
1477
1478                         if (((ssize_t)((off_t)request.from + len) > client->exportsize)) {
1479                                 DEBUG("[RANGE!]");
1480                                 ERROR(client, reply, EINVAL);
1481                                 continue;
1482                         }
1483                 }
1484
1485                 if (command==NBD_CMD_WRITE) {
1486                         DEBUG("wr: net->buf, ");
1487                         while(len > 0) {
1488                                 readit(client->net, buf, currlen);
1489                                 DEBUG("buf->exp, ");
1490                                 if ((client->server->flags & F_READONLY) ||
1491                                     (client->server->flags & F_AUTOREADONLY)) {
1492                                         DEBUG("[WRITE to READONLY!]");
1493                                         ERROR(client, reply, EPERM);
1494                                         continue;
1495                                 }
1496                                 if (expwrite(request.from, buf, len, client,
1497                                              request.type & NBD_CMD_FLAG_FUA)) {
1498                                         DEBUG("Write failed: %m" );
1499                                         ERROR(client, reply, errno);
1500                                         continue;
1501                                 }
1502                                 SEND(client->net, reply);
1503                                 DEBUG("OK!\n");
1504                                 len -= currlen;
1505                                 currlen = (len < BUFSIZE) ? len : BUFSIZE;
1506                         }
1507                         continue;
1508                 }
1509
1510                 if (command==NBD_CMD_FLUSH) {
1511                         DEBUG("fl: ");
1512                         if (expflush(client)) {
1513                                 DEBUG("Flush failed: %m");
1514                                 ERROR(client, reply, errno);
1515                                 continue;
1516                         }
1517                         SEND(client->net, reply);
1518                         DEBUG("OK!\n");
1519                         continue;
1520                 }
1521
1522                 if (command==NBD_CMD_READ) {
1523                         DEBUG("exp->buf, ");
1524                         memcpy(buf, &reply, sizeof(struct nbd_reply));
1525                         if (client->transactionlogfd != -1)
1526                                 writeit(client->transactionlogfd, &reply, sizeof(reply));
1527                         p = buf + sizeof(struct nbd_reply);
1528                         writelen = currlen + sizeof(struct nbd_reply);
1529                         while(len > 0) {
1530                                 if (expread(request.from, p, currlen, client)) {
1531                                         DEBUG("Read failed: %m");
1532                                         ERROR(client, reply, errno);
1533                                         continue;
1534                                 }
1535
1536                                 DEBUG("buf->net, ");
1537                                 writeit(client->net, buf, writelen);
1538                                 len -= currlen;
1539                                 request.from += currlen;
1540                                 currlen = (len < BUFSIZE) ? len : BUFSIZE;
1541                                 p = buf;
1542                                 writelen = currlen;
1543                         }
1544                         DEBUG("OK!\n");
1545                         continue;
1546                 }
1547
1548                 DEBUG ("Ignoring unknown command\n");
1549         }
1550         return 0;
1551 }
1552
1553 /**
1554  * Set up client export array, which is an array of FILE_INFO.
1555  * Also, split a single exportfile into multiple ones, if that was asked.
1556  * @param client information on the client which we want to setup export for
1557  **/
1558 void setupexport(CLIENT* client) {
1559         int i;
1560         off_t laststartoff = 0, lastsize = 0;
1561         int multifile = (client->server->flags & F_MULTIFILE);
1562
1563         client->export = g_array_new(TRUE, TRUE, sizeof(FILE_INFO));
1564
1565         /* If multi-file, open as many files as we can.
1566          * If not, open exactly one file.
1567          * Calculate file sizes as we go to get total size. */
1568         for(i=0; ; i++) {
1569                 FILE_INFO fi;
1570                 gchar *tmpname;
1571                 gchar* error_string;
1572                 mode_t mode = (client->server->flags & F_READONLY) ? O_RDONLY : O_RDWR;
1573
1574                 if(multifile) {
1575                         tmpname=g_strdup_printf("%s.%d", client->exportname, i);
1576                 } else {
1577                         tmpname=g_strdup(client->exportname);
1578                 }
1579                 DEBUG2( "Opening %s\n", tmpname );
1580                 fi.fhandle = open(tmpname, mode);
1581                 if(fi.fhandle == -1 && mode == O_RDWR) {
1582                         /* Try again because maybe media was read-only */
1583                         fi.fhandle = open(tmpname, O_RDONLY);
1584                         if(fi.fhandle != -1) {
1585                                 /* Opening the base file in copyonwrite mode is
1586                                  * okay */
1587                                 if(!(client->server->flags & F_COPYONWRITE)) {
1588                                         client->server->flags |= F_AUTOREADONLY;
1589                                         client->server->flags |= F_READONLY;
1590                                 }
1591                         }
1592                 }
1593                 if(fi.fhandle == -1) {
1594                         if(multifile && i>0)
1595                                 break;
1596                         error_string=g_strdup_printf(
1597                                 "Could not open exported file %s: %%m",
1598                                 tmpname);
1599                         err(error_string);
1600                 }
1601                 fi.startoff = laststartoff + lastsize;
1602                 g_array_append_val(client->export, fi);
1603                 g_free(tmpname);
1604
1605                 /* Starting offset and size of this file will be used to
1606                  * calculate starting offset of next file */
1607                 laststartoff = fi.startoff;
1608                 lastsize = size_autodetect(fi.fhandle);
1609
1610                 if(!multifile)
1611                         break;
1612         }
1613
1614         /* Set export size to total calculated size */
1615         client->exportsize = laststartoff + lastsize;
1616
1617         /* Export size may be overridden */
1618         if(client->server->expected_size) {
1619                 /* desired size must be <= total calculated size */
1620                 if(client->server->expected_size > client->exportsize) {
1621                         err("Size of exported file is too big\n");
1622                 }
1623
1624                 client->exportsize = client->server->expected_size;
1625         }
1626
1627         msg3(LOG_INFO, "Size of exported file/device is %llu", (unsigned long long)client->exportsize);
1628         if(multifile) {
1629                 msg3(LOG_INFO, "Total number of files: %d", i);
1630         }
1631 }
1632
1633 int copyonwrite_prepare(CLIENT* client) {
1634         off_t i;
1635         if ((client->difffilename = malloc(1024))==NULL)
1636                 err("Failed to allocate string for diff file name");
1637         snprintf(client->difffilename, 1024, "%s-%s-%d.diff",client->exportname,client->clientname,
1638                 (int)getpid()) ;
1639         client->difffilename[1023]='\0';
1640         msg3(LOG_INFO,"About to create map and diff file %s",client->difffilename) ;
1641         client->difffile=open(client->difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
1642         if (client->difffile<0) err("Could not create diff file (%m)") ;
1643         if ((client->difmap=calloc(client->exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
1644                 err("Could not allocate memory") ;
1645         for (i=0;i<client->exportsize/DIFFPAGESIZE;i++) client->difmap[i]=(u32)-1 ;
1646
1647         return 0;
1648 }
1649
1650 /**
1651  * Run a command. This is used for the ``prerun'' and ``postrun'' config file
1652  * options
1653  *
1654  * @param command the command to be ran. Read from the config file
1655  * @param file the file name we're about to export
1656  **/
1657 int do_run(gchar* command, gchar* file) {
1658         gchar* cmd;
1659         int retval=0;
1660
1661         if(command && *command) {
1662                 cmd = g_strdup_printf(command, file);
1663                 retval=system(cmd);
1664                 g_free(cmd);
1665         }
1666         return retval;
1667 }
1668
1669 /**
1670  * Serve a connection.
1671  *
1672  * @todo allow for multithreading, perhaps use libevent. Not just yet, though;
1673  * follow the road map.
1674  *
1675  * @param client a connected client
1676  **/
1677 void serveconnection(CLIENT *client) {
1678         if (client->server->transactionlog && (client->transactionlogfd == -1))
1679         {
1680                 if (-1 == (client->transactionlogfd = open(client->server->transactionlog,
1681                                                            O_WRONLY | O_CREAT,
1682                                                            S_IRUSR | S_IWUSR)))
1683                         g_warning("Could not open transaction log %s",
1684                                   client->server->transactionlog);
1685         }
1686
1687         if(do_run(client->server->prerun, client->exportname)) {
1688                 exit(EXIT_FAILURE);
1689         }
1690         setupexport(client);
1691
1692         if (client->server->flags & F_COPYONWRITE) {
1693                 copyonwrite_prepare(client);
1694         }
1695
1696         setmysockopt(client->net);
1697
1698         mainloop(client);
1699         do_run(client->server->postrun, client->exportname);
1700
1701         if (-1 != client->transactionlogfd)
1702         {
1703                 close(client->transactionlogfd);
1704                 client->transactionlogfd = -1;
1705         }
1706 }
1707
1708 /**
1709  * Find the name of the file we have to serve. This will use g_strdup_printf
1710  * to put the IP address of the client inside a filename containing
1711  * "%s" (in the form as specified by the "virtstyle" option). That name
1712  * is then written to client->exportname.
1713  *
1714  * @param net A socket connected to an nbd client
1715  * @param client information about the client. The IP address in human-readable
1716  * format will be written to a new char* buffer, the address of which will be
1717  * stored in client->clientname.
1718  **/
1719 void set_peername(int net, CLIENT *client) {
1720         struct sockaddr_storage addrin;
1721         struct sockaddr_storage netaddr;
1722         struct sockaddr_in  *netaddr4 = NULL;
1723         struct sockaddr_in6 *netaddr6 = NULL;
1724         size_t addrinlen = sizeof( addrin );
1725         struct addrinfo hints;
1726         struct addrinfo *ai = NULL;
1727         char peername[NI_MAXHOST];
1728         char netname[NI_MAXHOST];
1729         char *tmp = NULL;
1730         int i;
1731         int e;
1732         int shift;
1733
1734         if (getpeername(net, (struct sockaddr *) &addrin, (socklen_t *)&addrinlen) < 0)
1735                 err("getsockname failed: %m");
1736
1737         getnameinfo((struct sockaddr *)&addrin, (socklen_t)addrinlen,
1738                 peername, sizeof (peername), NULL, 0, NI_NUMERICHOST);
1739
1740         memset(&hints, '\0', sizeof (hints));
1741         hints.ai_flags = AI_ADDRCONFIG;
1742         e = getaddrinfo(peername, NULL, &hints, &ai);
1743
1744         if(e != 0) {
1745                 fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
1746                 freeaddrinfo(ai);
1747                 return;
1748         }
1749
1750         switch(client->server->virtstyle) {
1751                 case VIRT_NONE:
1752                         client->exportname=g_strdup(client->server->exportname);
1753                         break;
1754                 case VIRT_IPHASH:
1755                         for(i=0;i<strlen(peername);i++) {
1756                                 if(peername[i]=='.') {
1757                                         peername[i]='/';
1758                                 }
1759                         }
1760                 case VIRT_IPLIT:
1761                         client->exportname=g_strdup_printf(client->server->exportname, peername);
1762                         break;
1763                 case VIRT_CIDR:
1764                         memcpy(&netaddr, &addrin, addrinlen);
1765                         if(ai->ai_family == AF_INET) {
1766                                 netaddr4 = (struct sockaddr_in *)&netaddr;
1767                                 (netaddr4->sin_addr).s_addr>>=32-(client->server->cidrlen);
1768                                 (netaddr4->sin_addr).s_addr<<=32-(client->server->cidrlen);
1769
1770                                 getnameinfo((struct sockaddr *) netaddr4, (socklen_t) addrinlen,
1771                                                         netname, sizeof (netname), NULL, 0, NI_NUMERICHOST);
1772                                 tmp=g_strdup_printf("%s/%s", netname, peername);
1773                         }else if(ai->ai_family == AF_INET6) {
1774                                 netaddr6 = (struct sockaddr_in6 *)&netaddr;
1775
1776                                 shift = 128-(client->server->cidrlen);
1777                                 i = 3;
1778                                 while(shift >= 32) {
1779                                         ((netaddr6->sin6_addr).s6_addr32[i])=0;
1780                                         shift-=32;
1781                                         i--;
1782                                 }
1783                                 (netaddr6->sin6_addr).s6_addr32[i]>>=shift;
1784                                 (netaddr6->sin6_addr).s6_addr32[i]<<=shift;
1785
1786                                 getnameinfo((struct sockaddr *)netaddr6, (socklen_t)addrinlen,
1787                                             netname, sizeof(netname), NULL, 0, NI_NUMERICHOST);
1788                                 tmp=g_strdup_printf("%s/%s", netname, peername);
1789                         }
1790
1791                         if(tmp != NULL)
1792                           client->exportname=g_strdup_printf(client->server->exportname, tmp);
1793
1794                         break;
1795         }
1796
1797         freeaddrinfo(ai);
1798         msg4(LOG_INFO, "connect from %s, assigned file is %s",
1799              peername, client->exportname);
1800         client->clientname=g_strdup(peername);
1801 }
1802
1803 /**
1804  * Destroy a pid_t*
1805  * @param data a pointer to pid_t which should be freed
1806  **/
1807 void destroy_pid_t(gpointer data) {
1808         g_free(data);
1809 }
1810
1811 /**
1812  * Loop through the available servers, and serve them. Never returns.
1813  **/
1814 int serveloop(GArray* servers) {
1815         struct sockaddr_storage addrin;
1816         socklen_t addrinlen=sizeof(addrin);
1817         int i;
1818         int max;
1819         int sock;
1820         fd_set mset;
1821         fd_set rset;
1822
1823         /*
1824          * Set up the master fd_set. The set of descriptors we need
1825          * to select() for never changes anyway and it buys us a *lot*
1826          * of time to only build this once. However, if we ever choose
1827          * to not fork() for clients anymore, we may have to revisit
1828          * this.
1829          */
1830         max=0;
1831         FD_ZERO(&mset);
1832         for(i=0;i<servers->len;i++) {
1833                 if((sock=(g_array_index(servers, SERVER, i)).socket)) {
1834                         FD_SET(sock, &mset);
1835                         max=sock>max?sock:max;
1836                 }
1837         }
1838         if(modernsock) {
1839                 FD_SET(modernsock, &mset);
1840                 max=modernsock>max?modernsock:max;
1841         }
1842         for(;;) {
1843                 CLIENT *client = NULL;
1844                 pid_t *pid;
1845
1846                 memcpy(&rset, &mset, sizeof(fd_set));
1847                 if(select(max+1, &rset, NULL, NULL, NULL)>0) {
1848                         int net = 0;
1849                         SERVER* serve=NULL;
1850
1851                         DEBUG("accept, ");
1852                         if(FD_ISSET(modernsock, &rset)) {
1853                                 if((net=accept(modernsock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
1854                                         err("accept: %m");
1855                                 client = negotiate(net, NULL, servers);
1856                                 if(!client) {
1857                                         err_nonfatal("negotiation failed");
1858                                         close(net);
1859                                         net=0;
1860                                         continue;
1861                                 }
1862                                 serve = client->server;
1863                         }
1864                         for(i=0;i<servers->len && !net;i++) {
1865                                 serve=&(g_array_index(servers, SERVER, i));
1866                                 if(FD_ISSET(serve->socket, &rset)) {
1867                                         if ((net=accept(serve->socket, (struct sockaddr *) &addrin, &addrinlen)) < 0)
1868                                                 err("accept: %m");
1869                                 }
1870                         }
1871                         if(net) {
1872                                 int sock_flags;
1873
1874                                 if(serve->max_connections > 0 &&
1875                                    g_hash_table_size(children) >= serve->max_connections) {
1876                                         msg2(LOG_INFO, "Max connections reached");
1877                                         close(net);
1878                                         continue;
1879                                 }
1880                                 if((sock_flags = fcntl(net, F_GETFL, 0))==-1) {
1881                                         err("fcntl F_GETFL");
1882                                 }
1883                                 if(fcntl(net, F_SETFL, sock_flags &~O_NONBLOCK)==-1) {
1884                                         err("fcntl F_SETFL ~O_NONBLOCK");
1885                                 }
1886                                 if(!client) {
1887                                         client = g_new0(CLIENT, 1);
1888                                         client->server=serve;
1889                                         client->exportsize=OFFT_MAX;
1890                                         client->net=net;
1891                                         client->transactionlogfd = -1;
1892                                 }
1893                                 set_peername(net, client);
1894                                 if (!authorized_client(client)) {
1895                                         msg2(LOG_INFO,"Unauthorized client") ;
1896                                         close(net);
1897                                         continue;
1898                                 }
1899                                 msg2(LOG_INFO,"Authorized client") ;
1900                                 pid=g_malloc(sizeof(pid_t));
1901
1902                                 if (!dontfork) {
1903                                         if ((*pid=fork())<0) {
1904                                                 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
1905                                                 close(net);
1906                                                 continue;
1907                                         }
1908                                         if (*pid>0) { /* parent */
1909                                                 close(net);
1910                                                 g_hash_table_insert(children, pid, pid);
1911                                                 continue;
1912                                         }
1913                                         /* child */
1914                                         g_hash_table_destroy(children);
1915                                         for(i=0;i<servers->len;i++) {
1916                                                 serve=&g_array_index(servers, SERVER, i);
1917                                                 close(serve->socket);
1918                                         }
1919                                         /* FALSE does not free the
1920                                            actual data. This is required,
1921                                            because the client has a
1922                                            direct reference into that
1923                                            data, and otherwise we get a
1924                                            segfault... */
1925                                         g_array_free(servers, FALSE);
1926                                 }
1927
1928                                 msg2(LOG_INFO,"Starting to serve");
1929                                 serveconnection(client);
1930                                 exit(EXIT_SUCCESS);
1931                         }
1932                 }
1933         }
1934 }
1935
1936 void dosockopts(int socket) {
1937 #ifndef sun
1938         int yes=1;
1939 #else
1940         char yes='1';
1941 #endif /* sun */
1942         int sock_flags;
1943
1944         /* lose the pesky "Address already in use" error message */
1945         if (setsockopt(socket,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
1946                 err("setsockopt SO_REUSEADDR");
1947         }
1948         if (setsockopt(socket,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
1949                 err("setsockopt SO_KEEPALIVE");
1950         }
1951
1952         /* make the listening socket non-blocking */
1953         if ((sock_flags = fcntl(socket, F_GETFL, 0)) == -1) {
1954                 err("fcntl F_GETFL");
1955         }
1956         if (fcntl(socket, F_SETFL, sock_flags | O_NONBLOCK) == -1) {
1957                 err("fcntl F_SETFL O_NONBLOCK");
1958         }
1959 }
1960
1961 /**
1962  * Connect a server's socket.
1963  *
1964  * @param serve the server we want to connect.
1965  **/
1966 int setup_serve(SERVER *serve) {
1967         struct addrinfo hints;
1968         struct addrinfo *ai = NULL;
1969         gchar *port = NULL;
1970         int e;
1971
1972         if(!do_oldstyle) {
1973                 return serve->servename ? 1 : 0;
1974         }
1975         memset(&hints,'\0',sizeof(hints));
1976         hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG | AI_NUMERICSERV;
1977         hints.ai_socktype = SOCK_STREAM;
1978         hints.ai_family = serve->socket_family;
1979
1980         port = g_strdup_printf ("%d", serve->port);
1981         if (port == NULL)
1982                 return 0;
1983
1984         e = getaddrinfo(serve->listenaddr,port,&hints,&ai);
1985
1986         g_free(port);
1987
1988         if(e != 0) {
1989                 fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
1990                 serve->socket = -1;
1991                 freeaddrinfo(ai);
1992                 exit(EXIT_FAILURE);
1993         }
1994
1995         if(serve->socket_family == AF_UNSPEC)
1996                 serve->socket_family = ai->ai_family;
1997
1998 #ifdef WITH_SDP
1999         if ((serve->flags) && F_SDP) {
2000                 if (ai->ai_family == AF_INET)
2001                         ai->ai_family = AF_INET_SDP;
2002                 else (ai->ai_family == AF_INET6)
2003                         ai->ai_family = AF_INET6_SDP;
2004         }
2005 #endif
2006         if ((serve->socket = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol)) < 0)
2007                 err("socket: %m");
2008
2009         dosockopts(serve->socket);
2010
2011         DEBUG("Waiting for connections... bind, ");
2012         e = bind(serve->socket, ai->ai_addr, ai->ai_addrlen);
2013         if (e != 0 && errno != EADDRINUSE)
2014                 err("bind: %m");
2015         DEBUG("listen, ");
2016         if (listen(serve->socket, 1) < 0)
2017                 err("listen: %m");
2018
2019         freeaddrinfo (ai);
2020         if(serve->servename) {
2021                 return 1;
2022         } else {
2023                 return 0;
2024         }
2025 }
2026
2027 void open_modern(void) {
2028         struct addrinfo hints;
2029         struct addrinfo* ai = NULL;
2030         struct sock_flags;
2031         int e;
2032
2033         memset(&hints, '\0', sizeof(hints));
2034         hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
2035         hints.ai_socktype = SOCK_STREAM;
2036         hints.ai_family = AF_UNSPEC;
2037         hints.ai_protocol = IPPROTO_TCP;
2038         e = getaddrinfo(modern_listen, NBD_DEFAULT_PORT, &hints, &ai);
2039         if(e != 0) {
2040                 fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
2041                 exit(EXIT_FAILURE);
2042         }
2043         if((modernsock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol))<0) {
2044                 err("socket: %m");
2045         }
2046
2047         dosockopts(modernsock);
2048
2049         if(bind(modernsock, ai->ai_addr, ai->ai_addrlen)) {
2050                 err("bind: %m");
2051         }
2052         if(listen(modernsock, 10) <0) {
2053                 err("listen: %m");
2054         }
2055
2056         freeaddrinfo(ai);
2057 }
2058
2059 /**
2060  * Connect our servers.
2061  **/
2062 void setup_servers(GArray* servers) {
2063         int i;
2064         struct sigaction sa;
2065         int want_modern=0;
2066
2067         for(i=0;i<servers->len;i++) {
2068                 want_modern |= setup_serve(&(g_array_index(servers, SERVER, i)));
2069         }
2070         if(want_modern) {
2071                 open_modern();
2072         }
2073         children=g_hash_table_new_full(g_int_hash, g_int_equal, NULL, destroy_pid_t);
2074
2075         sa.sa_handler = sigchld_handler;
2076         sigemptyset(&sa.sa_mask);
2077         sa.sa_flags = SA_RESTART;
2078         if(sigaction(SIGCHLD, &sa, NULL) == -1)
2079                 err("sigaction: %m");
2080         sa.sa_handler = sigterm_handler;
2081         sigemptyset(&sa.sa_mask);
2082         sa.sa_flags = SA_RESTART;
2083         if(sigaction(SIGTERM, &sa, NULL) == -1)
2084                 err("sigaction: %m");
2085 }
2086
2087 /**
2088  * Go daemon (unless we specified at compile time that we didn't want this)
2089  * @param serve the first server of our configuration. If its port is zero,
2090  *      then do not daemonize, because we're doing inetd then. This parameter
2091  *      is only used to create a PID file of the form
2092  *      /var/run/nbd-server.&lt;port&gt;.pid; it's not modified in any way.
2093  **/
2094 #if !defined(NODAEMON)
2095 void daemonize(SERVER* serve) {
2096         FILE*pidf;
2097
2098         if(serve && !(serve->port)) {
2099                 return;
2100         }
2101         if(daemon(0,0)<0) {
2102                 err("daemon");
2103         }
2104         if(!*pidftemplate) {
2105                 if(serve) {
2106                         strncpy(pidftemplate, "/var/run/nbd-server.%d.pid", 255);
2107                 } else {
2108                         strncpy(pidftemplate, "/var/run/nbd-server.pid", 255);
2109                 }
2110         }
2111         snprintf(pidfname, 255, pidftemplate, serve ? serve->port : 0);
2112         pidf=fopen(pidfname, "w");
2113         if(pidf) {
2114                 fprintf(pidf,"%d\n", (int)getpid());
2115                 fclose(pidf);
2116         } else {
2117                 perror("fopen");
2118                 fprintf(stderr, "Not fatal; continuing");
2119         }
2120 }
2121 #else
2122 #define daemonize(serve)
2123 #endif /* !defined(NODAEMON) */
2124
2125 /*
2126  * Everything beyond this point (in the file) is run in non-daemon mode.
2127  * The stuff above daemonize() isn't.
2128  */
2129
2130 void serve_err(SERVER* serve, const char* msg) G_GNUC_NORETURN;
2131
2132 void serve_err(SERVER* serve, const char* msg) {
2133         g_message("Export of %s on port %d failed:", serve->exportname,
2134                         serve->port);
2135         err(msg);
2136 }
2137
2138 /**
2139  * Set up user-ID and/or group-ID
2140  **/
2141 void dousers(void) {
2142         struct passwd *pw;
2143         struct group *gr;
2144         gchar* str;
2145         if(rungroup) {
2146                 gr=getgrnam(rungroup);
2147                 if(!gr) {
2148                         str = g_strdup_printf("Invalid group name: %s", rungroup);
2149                         err(str);
2150                 }
2151                 if(setgid(gr->gr_gid)<0) {
2152                         err("Could not set GID: %m");
2153                 }
2154         }
2155         if(runuser) {
2156                 pw=getpwnam(runuser);
2157                 if(!pw) {
2158                         str = g_strdup_printf("Invalid user name: %s", runuser);
2159                         err(str);
2160                 }
2161                 if(setuid(pw->pw_uid)<0) {
2162                         err("Could not set UID: %m");
2163                 }
2164         }
2165 }
2166
2167 #ifndef ISSERVER
2168 void glib_message_syslog_redirect(const gchar *log_domain,
2169                                   GLogLevelFlags log_level,
2170                                   const gchar *message,
2171                                   gpointer user_data)
2172 {
2173     int level=LOG_DEBUG;
2174
2175     switch( log_level )
2176     {
2177       case G_LOG_FLAG_FATAL:
2178       case G_LOG_LEVEL_CRITICAL:
2179       case G_LOG_LEVEL_ERROR:
2180         level=LOG_ERR;
2181         break;
2182       case G_LOG_LEVEL_WARNING:
2183         level=LOG_WARNING;
2184         break;
2185       case G_LOG_LEVEL_MESSAGE:
2186       case G_LOG_LEVEL_INFO:
2187         level=LOG_INFO;
2188         break;
2189       case G_LOG_LEVEL_DEBUG:
2190         level=LOG_DEBUG;
2191       default:
2192         level=LOG_ERR;
2193     }
2194     syslog(level, "%s", message);
2195 }
2196 #endif
2197
2198 /**
2199  * Main entry point...
2200  **/
2201 int main(int argc, char *argv[]) {
2202         SERVER *serve;
2203         GArray *servers;
2204         GError *err=NULL;
2205
2206         if (sizeof( struct nbd_request )!=28) {
2207                 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
2208                 exit(EXIT_FAILURE) ;
2209         }
2210
2211         memset(pidftemplate, '\0', 256);
2212
2213         logging();
2214         config_file_pos = g_strdup(CFILE);
2215         serve=cmdline(argc, argv);
2216         servers = parse_cfile(config_file_pos, &err);
2217
2218         if(serve) {
2219                 serve->socket_family = AF_UNSPEC;
2220
2221                 append_serve(serve, servers);
2222
2223                 if (!(serve->port)) {
2224                         CLIENT *client;
2225 #ifndef ISSERVER
2226                         /* You really should define ISSERVER if you're going to use
2227                          * inetd mode, but if you don't, closing stdout and stderr
2228                          * (which inetd had connected to the client socket) will let it
2229                          * work. */
2230                         close(1);
2231                         close(2);
2232                         open("/dev/null", O_WRONLY);
2233                         open("/dev/null", O_WRONLY);
2234                         g_log_set_default_handler( glib_message_syslog_redirect, NULL );
2235 #endif
2236                         client=g_malloc(sizeof(CLIENT));
2237                         client->server=serve;
2238                         client->net=0;
2239                         client->exportsize=OFFT_MAX;
2240                         set_peername(0,client);
2241                         serveconnection(client);
2242                         return 0;
2243                 }
2244         }
2245
2246         if(!servers || !servers->len) {
2247                 if(err && !(err->domain == g_quark_from_string("parse_cfile")
2248                                 && err->code == CFILE_NOTFOUND)) {
2249                         g_warning("Could not parse config file: %s",
2250                                         err ? err->message : "Unknown error");
2251                 }
2252         }
2253         if(serve) {
2254                 g_warning("Specifying an export on the command line is deprecated.");
2255                 g_warning("Please use a configuration file instead.");
2256         }
2257
2258         if((!serve) && (!servers||!servers->len)) {
2259                 g_message("No configured exports; quitting.");
2260                 exit(EXIT_FAILURE);
2261         }
2262         if (!dontfork)
2263                 daemonize(serve);
2264         setup_servers(servers);
2265         dousers();
2266         serveloop(servers);
2267         return 0 ;
2268 }