2 * Network Block Device - server
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>
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
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
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
54 /* Includes LFS defines, which defines behaviours of some of the following
55 * headers, so must come before those */
58 #include <sys/types.h>
59 #include <sys/socket.h>
61 #include <sys/wait.h> /* wait */
62 #ifdef HAVE_SYS_IOCTL_H
63 #include <sys/ioctl.h>
65 #include <sys/param.h>
66 #ifdef HAVE_SYS_MOUNT_H
67 #include <sys/mount.h> /* For BLKGETSIZE */
69 #include <signal.h> /* sigaction */
70 #include <netinet/tcp.h>
71 #include <netinet/in.h> /* sockaddr_in, htons, in_addr */
72 #include <netdb.h> /* hostent, gethostby*, getservby* */
79 #include <arpa/inet.h>
87 /* used in cliserv.h, so must come first */
88 #define MY_NAME "nbd_server"
91 /** how much space for child PIDs we have by default. Dynamically
92 allocated, and will be realloc()ed if out of space, so this should
93 probably be fair for most situations. */
94 #define DEFAULT_CHILD_ARRAY 256
96 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */
98 #define msg2(a,b) syslog(a,b)
99 #define msg3(a,b,c) syslog(a,b,c)
100 #define msg4(a,b,c,d) syslog(a,b,c,d)
102 #define msg2(a,b) g_message(b)
103 #define msg3(a,b,c) g_message(b,c)
104 #define msg4(a,b,c,d) g_message(b,c,d)
107 /* Debugging macros */
110 #define DEBUG( a ) printf( a )
111 #define DEBUG2( a,b ) printf( a,b )
112 #define DEBUG3( a,b,c ) printf( a,b,c )
115 #define DEBUG2( a,b )
116 #define DEBUG3( a,b,c )
118 #ifndef PACKAGE_VERSION
119 #define PACKAGE_VERSION ""
122 * The highest value a variable of type off_t can reach.
124 /* This is starting to get ugly. If someone knows a better way to find
125 * the maximum value of a signed type *without* relying on overflow
126 * (doing so breaks on 64bit architectures), that would be nice.
128 * Actually, do we need this at all? Can't we just say '0 is autodetect', and
129 * live with it? Or better yet, use an extra flag, or so?
130 * Answer: yes, we need it, as the hunksize is defined to this when the
131 * multiple file thingy isn't used.
133 #define OFFT_MAX (((((off_t)1)<<((sizeof(off_t)-1)*8))-1)<<7)+127
134 #define LINELEN 256 /**< Size of static buffer used to read the
135 authorization file (yuck) */
136 #define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */
137 #define GIGA (1*1024*1024*1024) /**< 1 Gigabyte. Used as hunksize when doing
138 the multiple file thingy. @todo: make this a
139 configuration option. */
140 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
141 #define F_READONLY 1 /**< flag to tell us a file is readonly */
142 #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
143 #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using
145 #define F_AUTOREADONLY 8 /**< flag to tell us a file is set to autoreadonly */
146 GHashTable *children;
147 char pidfname[256]; /**< name of our PID file */
148 char default_authname[] = "/etc/nbd_server.allow"; /**< default name of allow file */
151 * Variables associated with a server.
154 char* exportname; /**< (unprocessed) filename of the file we're exporting */
155 off_t hunksize; /**< size of a hunk of an exported file */
156 off_t expected_size; /**< size of the exported file as it was told to
157 us through configuration */
158 unsigned int port; /**< port we're exporting this file at */
159 char* authname; /**< filename of the authorization file */
160 int flags; /**< flags associated with this exported file */
161 unsigned int timeout;/**< how long a connection may be idle
163 int socket; /**< The socket of this server. */
167 * Variables associated with a client socket.
170 off_t exportsize; /**< size of the file we're exporting */
171 char *clientname; /**< peer */
172 char *exportname; /**< (processed) filename of the file we're exporting */
173 int export[1024]; /**< array of filedescriptors of exported files;
174 only the first is actually used unless we're
175 doing the multiple file option */
176 int net; /**< The actual client socket */
177 SERVER *server; /**< The server this client is getting data from */
178 char* difffilename; /**< filename of the copy-on-write file, if any */
179 int difffile; /**< filedescriptor of copyonwrite file. @todo
180 shouldn't this be an array too? (cfr export) Or
181 make -m and -c mutually exclusive */
182 u32 difffilelen; /**< number of pages in difffile */
183 u32 *difmap; /**< see comment on the global difmap for this one */
187 * Check whether a client is allowed to connect. Works with an authorization
188 * file which contains one line per machine, no wildcards.
190 * @param name IP address of client trying to connect (in human-readable form)
191 * @return 0 - authorization refused, 1 - OK
193 int authorized_client(CLIENT *opts) {
198 if ((f=fopen(opts->server->authname,"r"))==NULL) {
199 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
200 opts->server->authname,strerror(errno)) ;
204 while (fgets(line,LINELEN,f)!=NULL) {
205 if (strncmp(line,opts->clientname,strlen(opts->clientname))==0) {
215 * Read data from a file descriptor into a buffer
217 * @param f a file descriptor
218 * @param buf a buffer
219 * @param len the number of bytes to be read
221 inline void readit(int f, void *buf, size_t len) {
225 if ((res = read(f, buf, len)) <= 0)
226 err("Read failed: %m");
233 * Write data from a buffer into a filedescriptor
235 * @param f a file descriptor
236 * @param buf a buffer containing data
237 * @param len the number of bytes to be written
239 inline void writeit(int f, void *buf, size_t len) {
243 if ((res = write(f, buf, len)) <= 0)
244 err("Send failed: %m");
251 * Print out a message about how to use nbd-server. Split out to a separate
252 * function so that we can call it from multiple places
255 printf("This is nbd-server version " VERSION "\n");
256 printf("Usage: port file_to_export [size][kKmM] [-l authorize_file] [-r] [-m] [-c] [-a timeout_sec]\n"
257 "\t-r|--read-only\t\tread only\n"
258 "\t-m|--multi-file\t\tmultiple file\n"
259 "\t-c|--copy-on-write\tcopy on write\n"
260 "\t-l|--authorize-file\tfile with list of hosts that are allowed to\n\t\t\t\tconnect.\n"
261 "\t-a|--idle-time\t\tmaximum idle seconds; server terminates when\n\t\t\t\tidle time exceeded\n\n"
262 "\tif port is set to 0, stdin is used (for running from inetd)\n"
263 "\tif file_to_export contains '%%s', it is substituted with the IP\n"
264 "\t\taddress of the machine trying to connect\n" );
268 * Parse the command line.
270 * @todo getopt() is a great thing, and easy to use. Also, we want to
271 * create a configuration file which nbd-server will read. Maybe do (as in,
274 * @param argc the argc argument to main()
275 * @param argv the argv argument to main()
277 SERVER* cmdline(int argc, char *argv[]) {
280 struct option long_options[] = {
281 {"read-only", no_argument, NULL, 'r'},
282 {"multi-file", no_argument, NULL, 'm'},
283 {"copy-on-write", no_argument, NULL, 'c'},
284 {"authorize-file", required_argument, NULL, 'l'},
285 {"idle-time", required_argument, NULL, 'a'},
290 serve=g_malloc(sizeof(SERVER));
291 serve->hunksize=OFFT_MAX;
292 while((c=getopt_long(argc, argv, "a:cl:mr", long_options, &i))>=0) {
295 serve->flags |= F_READONLY;
298 serve->flags |= F_MULTIFILE;
299 serve->hunksize = 1*GIGA;
300 serve->authname = default_authname;
303 serve->flags |=F_COPYONWRITE;
306 serve->authname=optarg;
309 serve->timeout=strtol(optarg, NULL, 0);
317 /* What's left: the port to export, the name of the to be exported
318 * file, and, optionally, the size of the file, in that order. */
323 serve->port=strtol(argv[i], NULL, 0);
328 serve->exportname = argv[i];
331 size_t last = strlen(argv[i])-1;
332 char suffix = argv[i][last];
333 if (suffix == 'k' || suffix == 'K' ||
334 suffix == 'm' || suffix == 'M')
335 argv[i][last] = '\0';
336 es = (off_t)atol(argv[i]);
344 serve->expected_size = es;
350 * Signal handler for SIGCHLD
351 * @param s the signal we're handling (must be SIGCHLD, or something
354 void sigchld_handler(int s) {
360 while((pid=wait(status)) > 0) {
361 if(WIFEXITED(status)) {
362 msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status));
364 i=g_hash_table_lookup(children, &pid);
366 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld", (long)pid);
368 DEBUG2("Removing %d from the list of children", pid);
369 g_hash_table_remove(children, &pid);
375 * Kill a child. Called from sigterm_handler::g_hash_table_foreach.
378 * @param value the value corresponding to the above key
379 * @param user_data a pointer which we always set to 1, so that we know what
382 void killchild(gpointer key, gpointer value, gpointer user_data) {
384 int *parent=user_data;
391 * Handle SIGTERM and dispatch it to our children
392 * @param s the signal we're handling (must be SIGTERM, or something
393 * is severely wrong).
395 void sigterm_handler(int s) {
399 g_hash_table_foreach(children, killchild, &parent);
409 * Detect the size of a file.
411 * @param export An open filedescriptor
412 * @return the size of the file, or OFFT_MAX if detection was
415 off_t size_autodetect(int export) {
418 struct stat stat_buf;
421 #ifdef HAVE_SYS_MOUNT_H
422 #ifdef HAVE_SYS_IOCTL_H
424 DEBUG("looking for export size with ioctl BLKGETSIZE\n");
425 if (!ioctl(export, BLKGETSIZE, &es32) && es32) {
426 es = (off_t)es32 * (off_t)512;
429 #endif /* BLKGETSIZE */
430 #endif /* HAVE_SYS_IOCTL_H */
431 #endif /* HAVE_SYS_MOUNT_H */
433 DEBUG("looking for export size with fstat\n");
434 stat_buf.st_size = 0;
435 error = fstat(export, &stat_buf);
437 if(stat_buf.st_size > 0)
438 return (off_t)stat_buf.st_size;
440 err("fstat failed: %m");
443 DEBUG("looking for export size with lseek SEEK_END\n");
444 es = lseek(export, (off_t)0, SEEK_END);
445 if (es > ((off_t)0)) {
448 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
451 err("Could not find size of exported block device: %m");
456 * seek to a position in a file, with error handling.
457 * @param handle a filedescriptor
458 * @param a position to seek to
459 * @todo get rid of this; lastpoint is a global variable right now, but it
460 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
463 void myseek(int handle,off_t a) {
464 if (lseek(handle, a, SEEK_SET) < 0) {
465 err("Can not seek locally!\n");
470 * Write an amount of bytes at a given offset to the right file. This
471 * abstracts the write-side of the multiple file option.
473 * @param a The offset where the write should start
474 * @param buf The buffer to write from
475 * @param len The length of buf
476 * @return The number of bytes actually written, or -1 in case of an error
478 int rawexpwrite(off_t a, char *buf, size_t len, CLIENT *client) {
481 myseek(client->export[(int)a/client->server->hunksize],
482 a%client->server->hunksize);
483 res = write(client->export[(int)((off_t)a/(off_t)(client->server->hunksize))], buf, len);
484 return (res < 0 || (size_t)res != len);
488 * Read an amount of bytes at a given offset from the right file. This
489 * abstracts the read-side of the multiple files option.
491 * @param a The offset where the read should start
492 * @param buf A buffer to read into
493 * @param len The size of buf
494 * @return The number of bytes actually read, or -1 in case of an
497 int rawexpread(off_t a, char *buf, size_t len, CLIENT *client) {
500 myseek(client->export[(int)a/client->server->hunksize],
501 a%client->server->hunksize);
502 res = read(client->export[(int)a/client->server->hunksize], buf, len);
503 return (res < 0 || (size_t)res != len);
507 * Read an amount of bytes at a given offset from the right file. This
508 * abstracts the read-side of the copyonwrite stuff, and calls
509 * rawexpread() with the right parameters to do the actual work.
510 * @param a The offset where the read should start
511 * @param buf A buffer to read into
512 * @param len The size of buf
513 * @return The number of bytes actually read, or -1 in case of an error
515 int expread(off_t a, char *buf, size_t len, CLIENT *client) {
517 off_t mapcnt, mapl, maph, pagestart;
519 if (!(client->server->flags & F_COPYONWRITE))
520 return rawexpread(a, buf, len, client);
521 DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
523 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
525 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
526 pagestart=mapcnt*DIFFPAGESIZE;
528 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
529 len : (size_t)DIFFPAGESIZE-offset;
530 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
531 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
532 (unsigned long)(client->difmap[mapcnt]));
533 myseek(client->difffile, client->difmap[mapcnt]*DIFFPAGESIZE+offset);
534 if (read(client->difffile, buf, rdlen) != rdlen) return -1;
535 } else { /* the block is not there */
536 DEBUG2("Page %Lu is not here, we read the original one\n",
537 (unsigned long long)mapcnt);
538 return rawexpread(a, buf, rdlen, client);
540 len-=rdlen; a+=rdlen; buf+=rdlen;
546 * Write an amount of bytes at a given offset to the right file. This
547 * abstracts the write-side of the copyonwrite option, and calls
548 * rawexpwrite() with the right parameters to do the actual work.
550 * @param a The offset where the write should start
551 * @param buf The buffer to write from
552 * @param len The length of buf
553 * @return The number of bytes actually written, or -1 in case of an error
555 int expwrite(off_t a, char *buf, size_t len, CLIENT *client) {
556 char pagebuf[DIFFPAGESIZE];
557 off_t mapcnt,mapl,maph;
562 if (!(client->server->flags & F_COPYONWRITE))
563 return(rawexpwrite(a,buf,len, client));
564 DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
566 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
568 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
569 pagestart=mapcnt*DIFFPAGESIZE ;
571 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
572 len : (size_t)DIFFPAGESIZE-offset;
574 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
575 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
576 (unsigned long)(client->difmap[mapcnt])) ;
577 myseek(client->difffile,
578 client->difmap[mapcnt]*DIFFPAGESIZE+offset);
579 if (write(client->difffile, buf, wrlen) != wrlen) return -1 ;
580 } else { /* the block is not there */
581 myseek(client->difffile,client->difffilelen*DIFFPAGESIZE) ;
582 client->difmap[mapcnt]=client->difffilelen++ ;
583 DEBUG3("Page %Lu is not here, we put it at %lu\n",
584 (unsigned long long)mapcnt,
585 (unsigned long)(client->difmap[mapcnt]));
587 if (rdlen+pagestart%(client->server->hunksize) >
588 (client->server->hunksize))
589 rdlen=client->server->hunksize -
590 (pagestart%client->server->hunksize);
591 if (rawexpread(pagestart, pagebuf, rdlen, client))
593 memcpy(pagebuf+offset,buf,wrlen) ;
594 if (write(client->difffile, pagebuf, DIFFPAGESIZE) !=
598 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
604 * Do the initial negotiation.
606 * @param net A socket to do the negotiation over
608 void negotiate(CLIENT *client) {
612 memset(zeros, 0, 290);
613 if (write(client->net, INIT_PASSWD, 8) < 0)
614 err("Negotiation failed: %m");
615 cliserv_magic = htonll(cliserv_magic);
616 if (write(client->net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
617 err("Negotiation failed: %m");
618 size_host = htonll((u64)(client->exportsize));
619 if (write(client->net, &size_host, 8) < 0)
620 err("Negotiation failed: %m");
621 if (write(client->net, zeros, 128) < 0)
622 err("Negotiation failed: %m");
625 /** sending macro. */
626 #define SEND(net,reply) writeit( net, &reply, sizeof( reply ));
628 #define ERROR(client,reply) { reply.error = htonl(-1); SEND(client->net,reply); reply.error = 0; }
630 * Serve a file to a single client.
632 * @todo This beast needs to be split up in many tiny little manageable
633 * pieces. Preferably with a chainsaw.
635 * @param net A network socket, connected to an nbd client
638 int mainloop(CLIENT *client) {
639 struct nbd_request request;
640 struct nbd_reply reply;
646 DEBUG("Entering request loop!\n");
647 reply.magic = htonl(NBD_REPLY_MAGIC);
656 if (client->server->timeout)
657 alarm(client->server->timeout);
658 readit(client->net, &request, sizeof(request));
659 request.from = ntohll(request.from);
660 request.type = ntohl(request.type);
662 if (request.type==NBD_CMD_DISC) {
663 msg2(LOG_INFO, "Disconnect request received.");
664 if (client->difmap) g_free(client->difmap) ;
665 if (client->difffile>=0) {
666 close(client->difffile);
667 unlink(client->difffilename);
673 len = ntohl(request.len);
675 if (request.magic != htonl(NBD_REQUEST_MAGIC))
676 err("Not enough magic.");
678 err("Request too big!");
680 printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
681 "READ", (unsigned long long)request.from,
682 (unsigned long long)request.from / 512, len);
684 memcpy(reply.handle, request.handle, sizeof(reply.handle));
685 if ((request.from + len) > (OFFT_MAX)) {
686 DEBUG("[Number too large!]");
687 ERROR(client, reply);
691 if (((ssize_t)((off_t)request.from + len) > client->exportsize) ||
692 ((client->server->flags & F_READONLY) && request.type)) {
694 ERROR(client, reply);
698 if (request.type==NBD_CMD_WRITE) {
699 DEBUG("wr: net->buf, ");
700 readit(client->net, buf, len);
702 if ((client->server->flags & F_AUTOREADONLY) ||
703 expwrite(request.from, buf, len,
705 DEBUG("Write failed: %m" );
706 ERROR(client, reply);
709 SEND(client->net, reply);
716 if (expread(request.from, buf + sizeof(struct nbd_reply), len, client)) {
717 DEBUG("Read failed: %m");
718 ERROR(client, reply);
723 memcpy(buf, &reply, sizeof(struct nbd_reply));
724 writeit(client->net, buf, len + sizeof(struct nbd_reply));
730 * Split a single exportfile into multiple ones, if that was asked.
731 * @return 0 on success, -1 on failure
732 * @param client information on the client which we want to split
734 int splitexport(CLIENT* client) {
737 for (i=0; i<client->exportsize; i+=client->server->hunksize) {
740 if(client->server->flags & F_MULTIFILE) {
741 tmpname=g_strdup_printf("%s.%d", client->exportname,
742 (int)(i/client->server->hunksize));
744 tmpname=g_strdup(client->exportname);
746 DEBUG2( "Opening %s\n", tmpname );
747 if ((client->export[ i/ client->server->hunksize ] =
748 open(tmpname, (client->server->flags &
749 F_READONLY) ? O_RDONLY
751 /* Read WRITE ACCESS was requested by media is only read only */
752 client->server->flags |= F_AUTOREADONLY;
753 client->server->flags |= F_READONLY;
754 if ((client->export[i/client->server->hunksize] =
755 open(tmpname, O_RDONLY)) == -1)
756 err("Could not open exported file: %m");
761 if (client->server->flags & F_COPYONWRITE) {
762 snprintf(client->difffilename, 1024, "%s-%s-%d.diff",client->exportname,client->clientname,
764 client->difffilename[1023]='\0';
765 msg3(LOG_INFO,"About to create map and diff file %s",client->difffilename) ;
766 client->difffile=open(client->difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
767 if (client->difffile<0) err("Could not create diff file (%m)") ;
768 if ((client->difmap=calloc(client->exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
769 err("Could not allocate memory") ;
770 for (i=0;i<client->exportsize/DIFFPAGESIZE;i++) client->difmap[i]=(u32)-1 ;
777 * Serve a connection.
779 * @todo allow for multithreading, perhaps use libevent. Not just yet, though;
780 * follow the road map.
782 * @param net A network socket connected to an nbd client
784 void serveconnection(CLIENT *client) {
788 if (!client->server->expected_size) {
789 client->exportsize = size_autodetect(client->export[0]);
791 /* Perhaps we should check first. Not now. */
792 client->exportsize = client->server->expected_size;
794 if (client->exportsize > OFFT_MAX) {
795 /* uhm, well... In a parallel universe, this *might* be
797 err("Size of exported file is too big\n");
800 msg3(LOG_INFO, "size of exported file/device is %Lu", (unsigned long long)client->exportsize);
803 setmysockopt(client->net);
809 * Find the name of the file we have to serve. This will use g_strdup_printf
810 * to put the IP address of the client inside a filename containing
811 * "%s". That name is then written to client->exportname.
813 * @param net A socket connected to an nbd client
814 * @param client information about the client. The IP address in human-readable
815 * format will be written to a new char* buffer, the address of which will be
816 * stored in client->clientname.
818 void set_peername(int net, CLIENT *client) {
819 struct sockaddr_in addrin;
820 int addrinlen = sizeof( addrin );
823 if (getpeername(net, (struct sockaddr *) &addrin, (socklen_t *)&addrinlen) < 0)
824 err("getsockname failed: %m");
825 peername = inet_ntoa(addrin.sin_addr);
826 client->exportname=g_strdup_printf(client->server->exportname, peername);
828 msg4(LOG_INFO, "connect from %s, assigned file is %s",
829 peername, client->exportname);
830 client->clientname=g_strdup(peername);
835 * @param data a pointer to pid_t which should be freed
837 void destroy_pid_t(gpointer data) {
842 * Go daemon (unless we specified at compile time that we didn't want this)
843 * @param serve the first server of our configuration. If its port is zero,
844 * then do not daemonize, because we're doing inetd then.
846 #if !defined(NODAEMON) && !defined(NOFORK)
847 void daemonize(SERVER* serve) {
854 snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", serve->port);
855 pidf=fopen(pidfname, "w");
857 fprintf(pidf,"%d", (int)getpid());
861 fprintf(stderr, "Not fatal; continuing");
866 #define daemonize(serve)
867 #endif /* !defined(NODAEMON) && !defined(NOFORK) */
870 * Connect a server's socket.
872 * @todo modularize this giant beast. Preferably with a chainsaw. Also,
873 * it has no business starting mainloop(), through serveconnection(); it
874 * should connect, and be done with it.
876 * @param serve the server we want to connect.
878 void setup_serve(SERVER* serve) {
879 struct sockaddr_in addrin;
881 int addrinlen = sizeof(addrin);
889 if ((serve->socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
892 /* lose the pesky "Address already in use" error message */
893 if (setsockopt(serve->socket,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
894 err("setsockopt SO_REUSEADDR");
896 if (setsockopt(serve->socket,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
897 err("setsockopt SO_KEEPALIVE");
900 DEBUG("Waiting for connections... bind, ");
901 addrin.sin_family = AF_INET;
902 addrin.sin_port = htons(serve->port);
903 addrin.sin_addr.s_addr = 0;
904 if (bind(serve->socket, (struct sockaddr *) &addrin, addrinlen) < 0)
907 if (listen(serve->socket, 1) < 0)
909 sa.sa_handler = sigchld_handler;
910 sigemptyset(&sa.sa_mask);
911 sa.sa_flags = SA_RESTART;
912 if(sigaction(SIGCHLD, &sa, NULL) == -1)
913 err("sigaction: %m");
914 sa.sa_handler = sigterm_handler;
915 sigemptyset(&sa.sa_mask);
916 sa.sa_flags = SA_RESTART;
917 if(sigaction(SIGTERM, &sa, NULL) == -1)
918 err("sigaction: %m");
919 children=g_hash_table_new_full(g_int_hash, g_int_equal, NULL, destroy_pid_t);
923 * Loop through the available servers, and serve them.
925 * Actually, right now we only handle one server. Will change that for
928 int serveloop(SERVER* serve) {
929 struct sockaddr_in addrin;
930 int addrinlen=sizeof(addrin);
937 if ((net = accept(serve->socket, (struct sockaddr *) &addrin, &addrinlen)) < 0)
940 client = g_malloc(sizeof(CLIENT));
941 client->server=serve;
942 client->exportsize=OFFT_MAX;
944 set_peername(net, client);
945 if (!authorized_client(client)) {
946 msg2(LOG_INFO,"Unauthorized client") ;
950 msg2(LOG_INFO,"Authorized client") ;
951 pid=g_malloc(sizeof(pid_t));
953 if ((*pid=fork())<0) {
954 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
958 if (*pid>0) { /* parent */
960 g_hash_table_insert(children, pid, pid);
964 g_hash_table_destroy(children);
965 close(serve->socket) ;
967 msg2(LOG_INFO,"Starting to serve") ;
968 serveconnection(client);
973 * Main entry point...
975 int main(int argc, char *argv[]) {
979 if (sizeof( struct nbd_request )!=28) {
980 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
985 serve=cmdline(argc, argv);
986 servers=g_array_new(TRUE, FALSE, sizeof(SERVER*));
988 if (!(serve->port)) {
991 /* You really should define ISSERVER if you're going to use
992 * inetd mode, but if you don't, closing stdout and stderr
993 * (which inetd had connected to the client socket) will let it
997 open("/dev/null", O_WRONLY);
998 open("/dev/null", O_WRONLY);
1000 client=g_malloc(sizeof(CLIENT));
1001 client->server=serve;
1003 client->exportsize=OFFT_MAX;
1004 set_peername(0,client);
1005 serveconnection(client);