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 */
150 * Variables associated with a server.
153 char* exportname; /**< (unprocessed) filename of the file we're exporting */
154 off_t hunksize; /**< size of a hunk of an exported file */
155 off_t expected_size; /**< size of the exported file as it was told to
156 us through configuration */
157 unsigned int port; /**< port we're exporting this file at */
158 char* authname; /**< filename of the authorization file */
159 int flags; /**< flags associated with this exported file */
160 unsigned int timeout;/**< how long a connection may be idle
162 int socket; /**< The socket of this server. */
166 * Variables associated with a client socket.
169 off_t exportsize; /**< size of the file we're exporting */
170 char *clientname; /**< peer */
171 char *exportname; /**< (processed) filename of the file we're exporting */
172 int export[1024]; /**< array of filedescriptors of exported files;
173 only the first is actually used unless we're
174 doing the multiple file option */
175 int net; /**< The actual client socket */
176 SERVER *server; /**< The server this client is getting data from */
177 char* difffilename; /**< filename of the copy-on-write file, if any */
178 int difffile; /**< filedescriptor of copyonwrite file. @todo
179 shouldn't this be an array too? (cfr export) Or
180 make -m and -c mutually exclusive */
181 u32 difffilelen; /**< number of pages in difffile */
182 u32 *difmap; /**< see comment on the global difmap for this one */
186 * Check whether a client is allowed to connect. Works with an authorization
187 * file which contains one line per machine, no wildcards.
189 * @param name IP address of client trying to connect (in human-readable form)
190 * @return 0 - authorization refused, 1 - OK
192 int authorized_client(CLIENT *opts) {
197 if ((f=fopen(opts->server->authname,"r"))==NULL) {
198 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
199 opts->server->authname,strerror(errno)) ;
203 while (fgets(line,LINELEN,f)!=NULL) {
204 if (strncmp(line,opts->clientname,strlen(opts->clientname))==0) {
214 * Read data from a file descriptor into a buffer
216 * @param f a file descriptor
217 * @param buf a buffer
218 * @param len the number of bytes to be read
220 inline void readit(int f, void *buf, size_t len) {
224 if ((res = read(f, buf, len)) <= 0)
225 err("Read failed: %m");
232 * Write data from a buffer into a filedescriptor
234 * @param f a file descriptor
235 * @param buf a buffer containing data
236 * @param len the number of bytes to be written
238 inline void writeit(int f, void *buf, size_t len) {
242 if ((res = write(f, buf, len)) <= 0)
243 err("Send failed: %m");
250 * Print out a message about how to use nbd-server. Split out to a separate
251 * function so that we can call it from multiple places
254 printf("This is nbd-server version " VERSION "\n");
255 printf("Usage: port file_to_export [size][kKmM] [-l authorize_file] [-r] [-m] [-c] [-a timeout_sec]\n"
256 "\t-r|--read-only\t\tread only\n"
257 "\t-m|--multi-file\t\tmultiple file\n"
258 "\t-c|--copy-on-write\tcopy on write\n"
259 "\t-l|--authorize-file\tfile with list of hosts that are allowed to\n\t\t\t\tconnect.\n"
260 "\t-a|--idle-time\t\tmaximum idle seconds; server terminates when\n\t\t\t\tidle time exceeded\n\n"
261 "\tif port is set to 0, stdin is used (for running from inetd)\n"
262 "\tif file_to_export contains '%%s', it is substituted with the IP\n"
263 "\t\taddress of the machine trying to connect\n" );
267 * Parse the command line.
269 * @todo getopt() is a great thing, and easy to use. Also, we want to
270 * create a configuration file which nbd-server will read. Maybe do (as in,
273 * @param argc the argc argument to main()
274 * @param argv the argv argument to main()
276 SERVER* cmdline(int argc, char *argv[]) {
279 struct option long_options[] = {
280 {"read-only", no_argument, NULL, 'r'},
281 {"multi-file", no_argument, NULL, 'm'},
282 {"copy-on-write", no_argument, NULL, 'c'},
283 {"authorize-file", required_argument, NULL, 'l'},
284 {"idle-time", required_argument, NULL, 'a'},
289 serve=g_malloc(sizeof(SERVER));
290 serve->hunksize=OFFT_MAX;
291 while((c=getopt_long(argc, argv, "a:cl:mr", long_options, &i))>=0) {
294 serve->flags |= F_READONLY;
297 serve->flags |= F_MULTIFILE;
298 serve->hunksize = 1*GIGA;
301 serve->flags |=F_COPYONWRITE;
304 serve->authname=optarg;
307 serve->timeout=strtol(optarg, NULL, 0);
315 /* What's left: the port to export, the name of the to be exported
316 * file, and, optionally, the size of the file, in that order. */
321 serve->port=strtol(argv[i], NULL, 0);
326 serve->exportname = argv[i];
329 size_t last = strlen(argv[i])-1;
330 char suffix = argv[i][last];
331 if (suffix == 'k' || suffix == 'K' ||
332 suffix == 'm' || suffix == 'M')
333 argv[i][last] = '\0';
334 es = (off_t)atol(argv[i]);
342 serve->expected_size = es;
348 * Signal handler for SIGCHLD
349 * @param s the signal we're handling (must be SIGCHLD, or something
352 void sigchld_handler(int s) {
358 while((pid=wait(status)) > 0) {
359 if(WIFEXITED(status)) {
360 msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status));
362 i=g_hash_table_lookup(children, &pid);
364 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld", (long)pid);
366 DEBUG2("Removing %d from the list of children", pid);
367 g_hash_table_remove(children, &pid);
373 * Kill a child. Called from sigterm_handler::g_hash_table_foreach.
376 * @param value the value corresponding to the above key
377 * @param user_data a pointer which we always set to 1, so that we know what
380 void killchild(gpointer key, gpointer value, gpointer user_data) {
382 int *parent=user_data;
389 * Handle SIGTERM and dispatch it to our children
390 * @param s the signal we're handling (must be SIGTERM, or something
391 * is severely wrong).
393 void sigterm_handler(int s) {
397 g_hash_table_foreach(children, killchild, &parent);
407 * Detect the size of a file.
409 * @param export An open filedescriptor
410 * @return the size of the file, or OFFT_MAX if detection was
413 off_t size_autodetect(int export) {
416 struct stat stat_buf;
419 #ifdef HAVE_SYS_MOUNT_H
420 #ifdef HAVE_SYS_IOCTL_H
422 DEBUG("looking for export size with ioctl BLKGETSIZE\n");
423 if (!ioctl(export, BLKGETSIZE, &es32) && es32) {
424 es = (off_t)es32 * (off_t)512;
427 #endif /* BLKGETSIZE */
428 #endif /* HAVE_SYS_IOCTL_H */
429 #endif /* HAVE_SYS_MOUNT_H */
431 DEBUG("looking for export size with fstat\n");
432 stat_buf.st_size = 0;
433 error = fstat(export, &stat_buf);
435 if(stat_buf.st_size > 0)
436 return (off_t)stat_buf.st_size;
438 err("fstat failed: %m");
441 DEBUG("looking for export size with lseek SEEK_END\n");
442 es = lseek(export, (off_t)0, SEEK_END);
443 if (es > ((off_t)0)) {
446 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
449 err("Could not find size of exported block device: %m");
454 * seek to a position in a file, with error handling.
455 * @param handle a filedescriptor
456 * @param a position to seek to
457 * @todo get rid of this; lastpoint is a global variable right now, but it
458 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
461 void myseek(int handle,off_t a) {
462 if (lseek(handle, a, SEEK_SET) < 0) {
463 err("Can not seek locally!\n");
468 * Write an amount of bytes at a given offset to the right file. This
469 * abstracts the write-side of the multiple file option.
471 * @param a The offset where the write should start
472 * @param buf The buffer to write from
473 * @param len The length of buf
474 * @return The number of bytes actually written, or -1 in case of an error
476 int rawexpwrite(off_t a, char *buf, size_t len, CLIENT *client) {
479 myseek(client->export[(int)a/client->server->hunksize],
480 a%client->server->hunksize);
481 res = write(client->export[(int)((off_t)a/(off_t)(client->server->hunksize))], buf, len);
482 return (res < 0 || (size_t)res != len);
486 * Read an amount of bytes at a given offset from the right file. This
487 * abstracts the read-side of the multiple files option.
489 * @param a The offset where the read should start
490 * @param buf A buffer to read into
491 * @param len The size of buf
492 * @return The number of bytes actually read, or -1 in case of an
495 int rawexpread(off_t a, char *buf, size_t len, CLIENT *client) {
498 myseek(client->export[(int)a/client->server->hunksize],
499 a%client->server->hunksize);
500 res = read(client->export[(int)a/client->server->hunksize], buf, len);
501 return (res < 0 || (size_t)res != len);
505 * Read an amount of bytes at a given offset from the right file. This
506 * abstracts the read-side of the copyonwrite stuff, and calls
507 * rawexpread() with the right parameters to do the actual work.
508 * @param a The offset where the read should start
509 * @param buf A buffer to read into
510 * @param len The size of buf
511 * @return The number of bytes actually read, or -1 in case of an error
513 int expread(off_t a, char *buf, size_t len, CLIENT *client) {
515 off_t mapcnt, mapl, maph, pagestart;
517 if (!(client->server->flags & F_COPYONWRITE))
518 return rawexpread(a, buf, len, client);
519 DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
521 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
523 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
524 pagestart=mapcnt*DIFFPAGESIZE;
526 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
527 len : (size_t)DIFFPAGESIZE-offset;
528 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
529 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
530 (unsigned long)(client->difmap[mapcnt]));
531 myseek(client->difffile, client->difmap[mapcnt]*DIFFPAGESIZE+offset);
532 if (read(client->difffile, buf, rdlen) != rdlen) return -1;
533 } else { /* the block is not there */
534 DEBUG2("Page %Lu is not here, we read the original one\n",
535 (unsigned long long)mapcnt);
536 return rawexpread(a, buf, rdlen, client);
538 len-=rdlen; a+=rdlen; buf+=rdlen;
544 * Write an amount of bytes at a given offset to the right file. This
545 * abstracts the write-side of the copyonwrite option, and calls
546 * rawexpwrite() with the right parameters to do the actual work.
548 * @param a The offset where the write should start
549 * @param buf The buffer to write from
550 * @param len The length of buf
551 * @return The number of bytes actually written, or -1 in case of an error
553 int expwrite(off_t a, char *buf, size_t len, CLIENT *client) {
554 char pagebuf[DIFFPAGESIZE];
555 off_t mapcnt,mapl,maph;
560 if (!(client->server->flags & F_COPYONWRITE))
561 return(rawexpwrite(a,buf,len, client));
562 DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
564 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
566 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
567 pagestart=mapcnt*DIFFPAGESIZE ;
569 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
570 len : (size_t)DIFFPAGESIZE-offset;
572 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
573 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
574 (unsigned long)(client->difmap[mapcnt])) ;
575 myseek(client->difffile,
576 client->difmap[mapcnt]*DIFFPAGESIZE+offset);
577 if (write(client->difffile, buf, wrlen) != wrlen) return -1 ;
578 } else { /* the block is not there */
579 myseek(client->difffile,client->difffilelen*DIFFPAGESIZE) ;
580 client->difmap[mapcnt]=client->difffilelen++ ;
581 DEBUG3("Page %Lu is not here, we put it at %lu\n",
582 (unsigned long long)mapcnt,
583 (unsigned long)(client->difmap[mapcnt]));
585 if (rdlen+pagestart%(client->server->hunksize) >
586 (client->server->hunksize))
587 rdlen=client->server->hunksize -
588 (pagestart%client->server->hunksize);
589 if (rawexpread(pagestart, pagebuf, rdlen, client))
591 memcpy(pagebuf+offset,buf,wrlen) ;
592 if (write(client->difffile, pagebuf, DIFFPAGESIZE) !=
596 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
602 * Do the initial negotiation.
604 * @param net A socket to do the negotiation over
606 void negotiate(CLIENT *client) {
610 memset(zeros, 0, 290);
611 if (write(client->net, INIT_PASSWD, 8) < 0)
612 err("Negotiation failed: %m");
613 cliserv_magic = htonll(cliserv_magic);
614 if (write(client->net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
615 err("Negotiation failed: %m");
616 size_host = htonll((u64)(client->exportsize));
617 if (write(client->net, &size_host, 8) < 0)
618 err("Negotiation failed: %m");
619 if (write(client->net, zeros, 128) < 0)
620 err("Negotiation failed: %m");
623 /** sending macro. */
624 #define SEND(net,reply) writeit( net, &reply, sizeof( reply ));
626 #define ERROR(client,reply) { reply.error = htonl(-1); SEND(client->net,reply); reply.error = 0; }
628 * Serve a file to a single client.
630 * @todo This beast needs to be split up in many tiny little manageable
631 * pieces. Preferably with a chainsaw.
633 * @param net A network socket, connected to an nbd client
636 int mainloop(CLIENT *client) {
637 struct nbd_request request;
638 struct nbd_reply reply;
644 DEBUG("Entering request loop!\n");
645 reply.magic = htonl(NBD_REPLY_MAGIC);
654 if (client->server->timeout)
655 alarm(client->server->timeout);
656 readit(client->net, &request, sizeof(request));
657 request.from = ntohll(request.from);
658 request.type = ntohl(request.type);
660 if (request.type==NBD_CMD_DISC) {
661 msg2(LOG_INFO, "Disconnect request received.");
662 if (client->difmap) g_free(client->difmap) ;
663 if (client->difffile>=0) {
664 close(client->difffile);
665 unlink(client->difffilename);
671 len = ntohl(request.len);
673 if (request.magic != htonl(NBD_REQUEST_MAGIC))
674 err("Not enough magic.");
676 err("Request too big!");
678 printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
679 "READ", (unsigned long long)request.from,
680 (unsigned long long)request.from / 512, len);
682 memcpy(reply.handle, request.handle, sizeof(reply.handle));
683 if ((request.from + len) > (OFFT_MAX)) {
684 DEBUG("[Number too large!]");
685 ERROR(client, reply);
689 if (((ssize_t)((off_t)request.from + len) > client->exportsize) ||
690 ((client->server->flags & F_READONLY) && request.type)) {
692 ERROR(client, reply);
696 if (request.type==NBD_CMD_WRITE) {
697 DEBUG("wr: net->buf, ");
698 readit(client->net, buf, len);
700 if ((client->server->flags & F_AUTOREADONLY) ||
701 expwrite(request.from, buf, len,
703 DEBUG("Write failed: %m" );
704 ERROR(client, reply);
707 SEND(client->net, reply);
714 if (expread(request.from, buf + sizeof(struct nbd_reply), len, client)) {
715 DEBUG("Read failed: %m");
716 ERROR(client, reply);
721 memcpy(buf, &reply, sizeof(struct nbd_reply));
722 writeit(client->net, buf, len + sizeof(struct nbd_reply));
728 * Split a single exportfile into multiple ones, if that was asked.
729 * @return 0 on success, -1 on failure
730 * @param client information on the client which we want to split
732 int splitexport(CLIENT* client) {
735 for (i=0; i<client->exportsize; i+=client->server->hunksize) {
738 if(client->server->flags & F_MULTIFILE) {
739 tmpname=g_strdup_printf("%s.%d", client->exportname,
740 (int)(i/client->server->hunksize));
742 tmpname=g_strdup(client->exportname);
744 DEBUG2( "Opening %s\n", tmpname );
745 if ((client->export[ i/ client->server->hunksize ] =
746 open(tmpname, (client->server->flags &
747 F_READONLY) ? O_RDONLY
749 /* Read WRITE ACCESS was requested by media is only read only */
750 client->server->flags |= F_AUTOREADONLY;
751 client->server->flags |= F_READONLY;
752 if ((client->export[i/client->server->hunksize] =
753 open(tmpname, O_RDONLY)) == -1)
754 err("Could not open exported file: %m");
759 if (client->server->flags & F_COPYONWRITE) {
760 snprintf(client->difffilename, 1024, "%s-%s-%d.diff",client->exportname,client->clientname,
762 client->difffilename[1023]='\0';
763 msg3(LOG_INFO,"About to create map and diff file %s",client->difffilename) ;
764 client->difffile=open(client->difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
765 if (client->difffile<0) err("Could not create diff file (%m)") ;
766 if ((client->difmap=calloc(client->exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
767 err("Could not allocate memory") ;
768 for (i=0;i<client->exportsize/DIFFPAGESIZE;i++) client->difmap[i]=(u32)-1 ;
775 * Serve a connection.
777 * @todo allow for multithreading, perhaps use libevent. Not just yet, though;
778 * follow the road map.
780 * @param net A network socket connected to an nbd client
782 void serveconnection(CLIENT *client) {
786 if (!client->server->expected_size) {
787 client->exportsize = size_autodetect(client->export[0]);
789 /* Perhaps we should check first. Not now. */
790 client->exportsize = client->server->expected_size;
792 if (client->exportsize > OFFT_MAX) {
793 /* uhm, well... In a parallel universe, this *might* be
795 err("Size of exported file is too big\n");
798 msg3(LOG_INFO, "size of exported file/device is %Lu", (unsigned long long)client->exportsize);
801 setmysockopt(client->net);
807 * Find the name of the file we have to serve. This will use g_strdup_printf
808 * to put the IP address of the client inside a filename containing
809 * "%s". That name is then written to client->exportname.
811 * @param net A socket connected to an nbd client
812 * @param client information about the client. The IP address in human-readable
813 * format will be written to a new char* buffer, the address of which will be
814 * stored in client->clientname.
816 void set_peername(int net, CLIENT *client) {
817 struct sockaddr_in addrin;
818 int addrinlen = sizeof( addrin );
821 if (getpeername(net, (struct sockaddr *) &addrin, (socklen_t *)&addrinlen) < 0)
822 err("getsockname failed: %m");
823 peername = inet_ntoa(addrin.sin_addr);
824 client->exportname=g_strdup_printf(client->server->exportname, peername);
826 msg4(LOG_INFO, "connect from %s, assigned file is %s",
827 peername, client->exportname);
828 client->clientname=g_strdup(peername);
833 * @param data a pointer to pid_t which should be freed
835 void destroy_pid_t(gpointer data) {
840 * Go daemon (unless we specified at compile time that we didn't want this)
841 * @param serve the first server of our configuration. If its port is zero,
842 * then do not daemonize, because we're doing inetd then.
844 #if !defined(NODAEMON) && !defined(NOFORK)
845 void daemonize(SERVER* serve) {
852 snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", serve->port);
853 pidf=fopen(pidfname, "w");
855 fprintf(pidf,"%d", (int)getpid());
859 fprintf(stderr, "Not fatal; continuing");
864 #define daemonize(serve)
865 #endif /* !defined(NODAEMON) && !defined(NOFORK) */
868 * Connect a server's socket.
870 * @todo modularize this giant beast. Preferably with a chainsaw. Also,
871 * it has no business starting mainloop(), through serveconnection(); it
872 * should connect, and be done with it.
874 * @param serve the server we want to connect.
876 void setup_serve(SERVER* serve) {
877 struct sockaddr_in addrin;
879 int addrinlen = sizeof(addrin);
887 if ((serve->socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
890 /* lose the pesky "Address already in use" error message */
891 if (setsockopt(serve->socket,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
892 err("setsockopt SO_REUSEADDR");
894 if (setsockopt(serve->socket,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
895 err("setsockopt SO_KEEPALIVE");
898 DEBUG("Waiting for connections... bind, ");
899 addrin.sin_family = AF_INET;
900 addrin.sin_port = htons(serve->port);
901 addrin.sin_addr.s_addr = 0;
902 if (bind(serve->socket, (struct sockaddr *) &addrin, addrinlen) < 0)
905 if (listen(serve->socket, 1) < 0)
907 sa.sa_handler = sigchld_handler;
908 sigemptyset(&sa.sa_mask);
909 sa.sa_flags = SA_RESTART;
910 if(sigaction(SIGCHLD, &sa, NULL) == -1)
911 err("sigaction: %m");
912 sa.sa_handler = sigterm_handler;
913 sigemptyset(&sa.sa_mask);
914 sa.sa_flags = SA_RESTART;
915 if(sigaction(SIGTERM, &sa, NULL) == -1)
916 err("sigaction: %m");
917 children=g_hash_table_new_full(g_int_hash, g_int_equal, NULL, destroy_pid_t);
921 * Loop through the available servers, and serve them.
924 int serveloop(SERVER* serve) {
925 struct sockaddr_in addrin;
926 int addrinlen=sizeof(addrin);
933 if ((net = accept(serve->socket, (struct sockaddr *) &addrin, &addrinlen)) < 0)
936 client = g_malloc(sizeof(CLIENT));
937 client->server=serve;
938 client->exportsize=OFFT_MAX;
940 set_peername(net, client);
941 if (!authorized_client(client)) {
942 msg2(LOG_INFO,"Unauthorized client") ;
946 msg2(LOG_INFO,"Authorized client") ;
947 pid=g_malloc(sizeof(pid_t));
949 if ((*pid=fork())<0) {
950 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
954 if (*pid>0) { /* parent */
956 g_hash_table_insert(children, pid, pid);
960 g_hash_table_destroy(children);
961 close(serve->socket) ;
963 msg2(LOG_INFO,"Starting to serve") ;
964 serveconnection(client);
969 * Main entry point...
971 int main(int argc, char *argv[]) {
975 if (sizeof( struct nbd_request )!=28) {
976 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
981 serve=cmdline(argc, argv);
982 servers=g_array_new(TRUE, FALSE, sizeof(SERVER*));
984 if (!(serve->port)) {
987 /* You really should define ISSERVER if you're going to use
988 * inetd mode, but if you don't, closing stdout and stderr
989 * (which inetd had connected to the client socket) will let it
993 open("/dev/null", O_WRONLY);
994 open("/dev/null", O_WRONLY);
996 client=g_malloc(sizeof(CLIENT));
997 client->server=serve;
999 client->exportsize=OFFT_MAX;
1000 set_peername(0,client);
1001 serveconnection(client);