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 (not released (yet?)).
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 */
59 #include <sys/types.h>
60 #include <sys/socket.h>
62 #include <sys/wait.h> /* wait */
63 #ifdef HAVE_SYS_IOCTL_H
64 #include <sys/ioctl.h>
66 #include <sys/param.h>
67 #ifdef HAVE_SYS_MOUNT_H
68 #include <sys/mount.h> /* For BLKGETSIZE */
70 #include <signal.h> /* sigaction */
71 #include <netinet/tcp.h>
72 #include <netinet/in.h> /* sockaddr_in, htons, in_addr */
73 #include <netdb.h> /* hostent, gethostby*, getservby* */
80 #include <arpa/inet.h>
86 /* used in cliserv.h, so must come first */
87 #define MY_NAME "nbd_server"
90 /** how much space for child PIDs we have by default. Dynamically
91 allocated, and will be realloc()ed if out of space, so this should
92 probably be fair for most situations. */
93 #define DEFAULT_CHILD_ARRAY 256
95 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */
97 #define msg2(a,b) syslog(a,"%s", b)
98 #define msg3(a,b,c) syslog(a,"%s %s", b,c)
99 #define msg4(a,b,c,d) syslog(a,"%s %s %s", b,c,d)
101 #define msg2(a,b) do { fprintf(stderr,"%s\n", b) ; } while(0)
102 #define msg3(a,b,c) do { fprintf(stderr,"%s %s\n", b,c); } while(0)
103 #define msg4(a,b,c,d) do { fprintf(stderr,"%s %s %s\n", b,c,d); } while(0)
106 /* Debugging macros */
109 #define DEBUG( a ) printf( a )
110 #define DEBUG2( a,b ) printf( a,b )
111 #define DEBUG3( a,b,c ) printf( a,b,c )
114 #define DEBUG2( a,b )
115 #define DEBUG3( a,b,c )
117 #ifndef PACKAGE_VERSION
118 #define PACKAGE_VERSION ""
121 * The highest value a variable of type off_t can reach.
123 /* This is starting to get ugly. If someone knows a better way to find
124 * the maximum value of a signed type *without* relying on overflow
125 * (doing so breaks on 64bit architectures), that would be nice.
127 #define OFFT_MAX (((((off_t)1)<<((sizeof(off_t)-1)*8))-1)<<7)+127
128 #define LINELEN 256 /**< Size of static buffer used to read the
129 authorization file (yuck) */
130 #define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */
131 #define GIGA (1*1024*1024*1024) /**< 1 Gigabyte. Used as hunksize when doing
132 the multiple file thingy */
133 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
134 #define F_READONLY 1 /**< flag to tell us a file is readonly */
135 #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
136 #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using copyonwrite */
137 char difffilename[1024]; /**< filename of the copy-on-write file. Doesn't belong here! */
138 unsigned int timeout = 0; /**< disconnect timeout */
139 int autoreadonly = 0; /**< 1 = switch to readonly if opening readwrite isn't
141 char *auth_file="nbd_server.allow"; /**< authorization file */
142 char exportname2[1024]; /**< File I'm exporting, with virtualhost resolved */
143 off_t lastpoint = (off_t)-1; /**< keep track of where we are in the file, to
144 avoid an lseek if possible */
145 char pagebuf[DIFFPAGESIZE]; /**< when doing copyonwrite, this is
146 used as a temporary buffer to store
147 the exported block in. @todo this is
148 a great example of namespace
149 pollution. Throw it out. */
150 unsigned int port; /**< Port I'm listening at */
151 char *exportname; /**< File I'm exporting */
152 off_t exportsize = OFFT_MAX; /**< length of file I'm exporting */
153 off_t hunksize = OFFT_MAX; /**< size of each exported file in case of -m */
154 int flags = 0; /**< flags associated with this exported file */
155 int export[1024];/**< array of filedescriptors of exported files; only first is
156 used unless -m option is activated */
157 int difffile=-1; /**< filedescriptor for copyonwrite file */
158 u32 difffilelen=0 ; /**< number of pages in difffile */
159 u32 *difmap=NULL ; /**< Determine whether a block is in the original file
160 (difmap[block]==-1) or in the copyonwrite file (in which
161 case it contains the offset where it is to be found in the
162 copyonwrite file). @todo the kernel knows about sparse
163 files, we should use those instead. Should also be off_t
164 instead of u32; copyonwrite is probably broken wrt LFS */
165 char clientname[256] ;
166 int child_arraysize=DEFAULT_CHILD_ARRAY; /**< number of available slots for
168 pid_t *children; /**< child array */
169 char pidfname[256]; /**< name of our PID file */
172 * Variables associated with a copyonwrite server. Not yet used.
175 char* difffilename; /**< filename of the copy-on-write file */
176 int difffile; /**< filedescriptor of copyonwrite file. @todo
177 shouldn't this be an array too? (cfr
178 nbd_server_opts::export) Or make -m and -c
179 mutually exclusive */
180 u32 difffilelen; /**< number of pages in difffile */
181 u32 *difmap; /**< see comment on the global difmap for this one */
185 * Variables associated with a server. Not yet used. @todo modify the code to
186 * use an instance of this struct instead of the heap of global variables.
189 char* exportname; /**< filename of the file we're exporting */
190 unsigned int port; /**< port we're exporting this file at */
191 char* authname; /**< filename of the authorization file */
192 off_t exportsize; /**< size of the file we're exporting */
193 off_t hunksize; /**< size of a hunk of an exported file */
194 int flags; /**< flags associated with this exported file */
195 char* clientname; /**< peer */
196 unsigned int timeout;/**< how long a connection may be idle
198 int export[1024]; /**< array of filedescriptors of exported files;
199 only the first is actually used unless we're
200 doing the multiple file option */
201 cow_opts* cow; /**< only used if (flags | F_COPYONWRITE) (NULL
206 * Check whether a client is allowed to connect. Works with an authorization
207 * file which contains one line per machine, no wildcards.
209 * @param name IP address of client trying to connect (in human-readable form)
210 * @return 0 - authorization refused, 1 - OK
212 int authorized_client(char *name)
218 if ((f=fopen(auth_file,"r"))==NULL) {
219 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
220 auth_file,strerror(errno)) ;
224 while (fgets(line,LINELEN,f)!=NULL) {
225 if (strncmp(line,name,strlen(name))==0) {
235 * Read data from a file descriptor into a buffer
237 * @param f a file descriptor
238 * @param buf a buffer
239 * @param len the number of bytes to be read
241 inline void readit(int f, void *buf, size_t len)
246 if ((res = read(f, buf, len)) <= 0)
247 err("Read failed: %m");
254 * Write data from a buffer into a filedescriptor
256 * @param f a file descriptor
257 * @param buf a buffer containing data
258 * @param len the number of bytes to be written
260 inline void writeit(int f, void *buf, size_t len)
265 if ((res = write(f, buf, len)) <= 0)
266 err("Send failed: %m");
273 * Parse the command line.
275 * @todo getopt() is a great thing, and easy to use. Also, we want to
276 * create a configuration file which nbd-server will read. Maybe do (as in,
279 * @param argc the argc argument to main()
280 * @param argv the argv argument to main()
282 void cmdline(int argc, char *argv[])
287 printf("This is nbd-server version " VERSION "\n");
288 printf("Usage: port file_to_export [size][kKmM] [-r] [-m] [-c] [-a timeout_sec]\n"
290 " -m multiple file\n"
291 " -c copy on write\n"
292 " -l file with list of hosts that are allowed to connect.\n"
293 " -a maximum idle seconds, terminates when idle time exceeded\n"
294 " if port is set to 0, stdin is used (for running from inetd)\n"
295 " if file_to_export contains '%%s', it is substituted with IP\n"
296 " address of machine trying to connect\n" );
299 port = atoi(argv[1]);
300 for (i = 3; i < argc; i++) {
301 if (*argv[i] == '-') {
302 switch (argv[i][1]) {
307 flags |= F_MULTIFILE;
310 case 'c': flags |=F_COPYONWRITE;
316 fprintf(stderr, "host list file requires an argument");
321 timeout = atoi(argv[i+1]);
324 fprintf(stderr, "timeout requires argument\n");
330 size_t last = strlen(argv[i])-1;
331 char suffix = argv[i][last];
332 if (suffix == 'k' || suffix == 'K' ||
333 suffix == 'm' || suffix == 'M')
334 argv[i][last] = '\0';
335 es = (off_t)atol(argv[i]);
347 exportname = argv[2];
351 * Signal handler for SIGCHLD
352 * @param s the signal we're handling (must be SIGCHLD, or something
355 void sigchld_handler(int s)
362 while((pid=wait(status)) > 0) {
363 if(WIFEXITED(status)) {
364 memset(buf,'\0', 80);
365 snprintf(buf, 79, "%d", WEXITSTATUS(status));
366 msg3(LOG_INFO, "Child exited with ", buf);
368 for(i=0;children[i]!=pid&&i<child_arraysize;i++);
369 if(i>=child_arraysize) {
370 memset(buf, '\0', 80);
371 snprintf(buf, 79, "%ld", (long)pid);
372 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID ", buf);
374 children[i]=(pid_t)0;
375 DEBUG2("Removing %d from the list of children", pid);
381 * Handle SIGTERM and dispatch it to our children
382 * @param s the signal we're handling (must be SIGTERM, or something
383 * is severely wrong).
385 void sigterm_handler(int s) {
389 for(i=0;i<child_arraysize;i++) {
391 kill(children[i], s);
404 * Detect the size of a file.
406 * @param export An open filedescriptor
407 * @return the size of the file, or OFFT_MAX if detection was
410 off_t size_autodetect(int export)
414 struct stat stat_buf;
417 #ifdef HAVE_SYS_MOUNT_H
418 #ifdef HAVE_SYS_IOCTL_H
420 DEBUG("looking for export size with ioctl BLKGETSIZE\n");
421 if (!ioctl(export, BLKGETSIZE, &es32) && es32) {
422 es = (off_t)es32 * (off_t)512;
425 #endif /* BLKGETSIZE */
426 #endif /* HAVE_SYS_IOCTL_H */
427 #endif /* HAVE_SYS_MOUNT_H */
429 DEBUG("looking for export size with fstat\n");
430 stat_buf.st_size = 0;
431 error = fstat(export, &stat_buf);
432 if (!error && stat_buf.st_size > 0) {
433 return (off_t)stat_buf.st_size;
435 err("fstat failed: %m");
438 DEBUG("looking for export size with lseek SEEK_END\n");
439 es = lseek(export, (off_t)0, SEEK_END);
440 if (es > ((off_t)0)) {
443 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
446 err("Could not find size of exported block device: %m");
451 * Seek to a position in a file, unless we're already there.
452 * @param handle a filedescriptor
453 * @param a position to seek to
455 void maybeseek(int handle, off_t a) {
456 if (a < 0 || a > exportsize) {
457 err("Can not happen\n");
459 if (lastpoint != a) {
460 if (lseek(handle, a, SEEK_SET) < 0) {
461 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)
482 maybeseek(export[a/hunksize], a%hunksize);
483 res = write(export[a/hunksize], buf, len);
484 return (res < 0 || (size_t)res != len);
488 * seek to a position in a file, no matter what. Used when using maybeseek is a
489 * bad idea (for instance, because we're reading the copyonwrite file instead
490 * of the exported file).
491 * @param handle a filedescriptor
492 * @param a position to seek to
493 * @todo get rid of this; lastpoint is a global variable right now, but it
494 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
497 void myseek(int handle,off_t a) {
498 if (lseek(handle, a, SEEK_SET) < 0) {
499 err("Can not seek locally!\n");
504 * Read an amount of bytes at a given offset from the right file. This
505 * abstracts the read-side of the multiple files option.
507 * @param a The offset where the read should start
508 * @param buf A buffer to read into
509 * @param len The size of buf
510 * @return The number of bytes actually read, or -1 in case of an
513 int rawexpread(off_t a, char *buf, size_t len)
517 maybeseek(export[a/hunksize], a%hunksize);
518 res = read(export[a/hunksize], buf, len);
519 return (res < 0 || (size_t)res != len);
523 * Read an amount of bytes at a given offset from the right file. This
524 * abstracts the read-side of the copyonwrite stuff, and calls
525 * rawexpread() with the right parameters to do the actual work.
526 * @param a The offset where the read should start
527 * @param buf A buffer to read into
528 * @param len The size of buf
529 * @return The number of bytes actually read, or -1 in case of an error
531 int expread(off_t a, char *buf, size_t len)
534 off_t mapcnt, mapl, maph, pagestart;
536 if (!(flags & F_COPYONWRITE))
537 return rawexpread(a, buf, len);
538 DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
540 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
542 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
543 pagestart=mapcnt*DIFFPAGESIZE;
545 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
546 len : (size_t)DIFFPAGESIZE-offset;
547 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
548 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
549 (unsigned long)difmap[mapcnt]);
550 myseek(difffile, difmap[mapcnt]*DIFFPAGESIZE+offset);
551 if (read(difffile, buf, rdlen) != rdlen) return -1;
552 } else { /* the block is not there */
553 DEBUG2("Page %Lu is not here, we read the original one\n",
554 (unsigned long long)mapcnt);
555 return rawexpread(a, buf, rdlen);
557 len-=rdlen; a+=rdlen; buf+=rdlen;
563 * Write an amount of bytes at a given offset to the right file. This
564 * abstracts the write-side of the copyonwrite option, and calls
565 * rawexpwrite() with the right parameters to do the actual work.
567 * @param a The offset where the write should start
568 * @param buf The buffer to write from
569 * @param len The length of buf
570 * @return The number of bytes actually written, or -1 in case of an error
572 int expwrite(off_t a, char *buf, size_t len)
574 off_t mapcnt,mapl,maph ;
579 if (!(flags & F_COPYONWRITE))
580 return(rawexpwrite(a,buf,len));
581 DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
583 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
585 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
586 pagestart=mapcnt*DIFFPAGESIZE ;
588 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
589 len : (size_t)DIFFPAGESIZE-offset;
591 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
592 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
593 (unsigned long)difmap[mapcnt]) ;
594 myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
595 if (write(difffile, buf, wrlen) != wrlen) return -1 ;
596 } else { /* the block is not there */
597 myseek(difffile,difffilelen*DIFFPAGESIZE) ;
598 difmap[mapcnt]=difffilelen++ ;
599 DEBUG3("Page %Lu is not here, we put it at %lu\n",
600 (unsigned long long)mapcnt,
601 (unsigned long)difmap[mapcnt]);
603 if (rdlen+pagestart%hunksize>hunksize)
604 rdlen=hunksize-(pagestart%hunksize) ;
605 if (rawexpread(pagestart,pagebuf,rdlen)) return -1 ;
606 memcpy(pagebuf+offset,buf,wrlen) ;
607 if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
609 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
615 * Do the initial negotiation.
617 * @param net A socket to do the negotiation over
619 void negotiate(int net) {
623 memset(zeros, 0, 290);
624 if (write(net, INIT_PASSWD, 8) < 0)
625 err("Negotiation failed: %m");
626 cliserv_magic = htonll(cliserv_magic);
627 if (write(net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
628 err("Negotiation failed: %m");
629 size_host = htonll((u64)exportsize);
630 if (write(net, &size_host, 8) < 0)
631 err("Negotiation failed: %m");
632 if (write(net, zeros, 128) < 0)
633 err("Negotiation failed: %m");
636 /** sending macro; not really required. Uses variables in the local
637 * scope of mainloop(). Get rid of it. */
638 #define SEND writeit( net, &reply, sizeof( reply ));
639 /** error macro; not sure whether we really need this. Uses variables
640 * in the local scope of mainloop(). Get rid of this beast. */
641 #define ERROR { reply.error = htonl(-1); SEND; reply.error = 0; lastpoint = -1; }
643 * Serve a file to a single client.
645 * @todo This beast needs to be split up in many tiny little manageable
646 * pieces. Preferably with a chainsaw.
648 * @param net A network socket, connected to an nbd client
651 int mainloop(int net)
653 struct nbd_request request;
654 struct nbd_reply reply;
659 DEBUG("Entering request loop!\n");
660 reply.magic = htonl(NBD_REPLY_MAGIC);
671 readit(net, &request, sizeof(request));
672 request.from = ntohll(request.from);
673 request.type = ntohl(request.type);
675 if (request.type==NBD_CMD_DISC) { /* Disconnect request */
676 if (difmap) free(difmap) ;
678 close(difffile) ; unlink(difffilename) ; }
679 err("Disconnect request received.") ;
682 len = ntohl(request.len);
684 if (request.magic != htonl(NBD_REQUEST_MAGIC))
685 err("Not enough magic.");
687 err("Request too big!");
689 printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
690 "READ", (unsigned long long)request.from,
691 (unsigned long long)request.from / 512, len);
693 memcpy(reply.handle, request.handle, sizeof(reply.handle));
694 if ((request.from + len) > (OFFT_MAX)) {
695 DEBUG("[Number too large!]");
700 if (((ssize_t)((off_t)request.from + len) > exportsize) ||
701 ((flags & F_READONLY) && request.type)) {
707 if (request.type==1) { /* WRITE */
708 DEBUG("wr: net->buf, ");
709 readit(net, buf, len);
711 if ((autoreadonly == 1) || expwrite(request.from, buf, len)) {
712 DEBUG("Write failed: %m" );
724 if (expread(request.from, buf + sizeof(struct nbd_reply), len)) {
726 DEBUG("Read failed: %m");
733 memcpy(buf, &reply, sizeof(struct nbd_reply));
734 writeit(net, buf, len + sizeof(struct nbd_reply));
740 * Split a single exportfile into multiple ones, if that was asked.
741 * @return 0 on success, -1 on failure
743 int splitexport(void) {
746 for (i=0; i<exportsize; i+=hunksize) {
747 char exportname3[1024];
749 if(flags & F_MULTIFILE) {
750 snprintf(exportname3, 1024, "%s.%d", exportname2, (int)(i/hunksize));
752 strncpy(exportname3, exportname2, 1024);
754 exportname3[1023]='\0';
755 DEBUG2( "Opening %s\n", exportname3 );
756 if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) {
757 /* Read WRITE ACCESS was requested by media is only read only */
760 if ((export[i/hunksize] = open(exportname3, O_RDONLY)) == -1)
761 err("Could not open exported file: %m");
765 if (flags & F_COPYONWRITE) {
766 snprintf(difffilename, 1024, "%s-%s-%d.diff",exportname2,clientname,
768 difffilename[1023]='\0';
769 msg3(LOG_INFO,"About to create map and diff file %s",difffilename) ;
770 difffile=open(difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
771 if (difffile<0) err("Could not create diff file (%m)") ;
772 if ((difmap=calloc(exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
773 err("Could not allocate memory") ;
774 for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
781 * Serve a connection.
783 * @todo allow for multithreading, perhaps use libevent.
785 * @param net A network socket connected to an nbd client
787 void serveconnection(int net) {
790 if (exportsize == OFFT_MAX) {
791 exportsize = size_autodetect(export[0]);
793 if (exportsize > OFFT_MAX) {
794 err("Size of exported file is too big\n");
797 memset(buf, '\0', 80);
798 snprintf(buf, 79, "%Lu", (unsigned long long)exportsize);
799 msg3(LOG_INFO, "size of exported file/device is ", buf);
808 * Find the name of the file we have to serve. This will use snprintf()
809 * to put the IP address of the client inside a filename containing
810 * "%s". That name is then written to exportname2
812 * @param net A socket connected to an nbd client
813 * @param clientname a buffer which must be at least 255+1 bytes long;
814 * the IP address (in human-readable format) will be copied in there.
816 void set_peername(int net,char *clientname)
818 struct sockaddr_in addrin;
819 int addrinlen = sizeof( addrin );
822 if (getpeername( net, (struct sockaddr *) &addrin, &addrinlen ) < 0)
823 err("getsockname failed: %m");
824 peername = inet_ntoa(addrin.sin_addr);
825 snprintf(exportname2, 1024, exportname, peername);
826 exportname2[1023]='\0';
828 msg4(LOG_INFO, "connect from %s, assigned file is %s",
829 peername, exportname2);
830 strncpy(clientname,peername,255) ;
834 * Connect the socket, and start to serve. This function will fork()
835 * if a connection from an authorized client is received, and will
838 * @todo modularize this giant beast. Preferably with a chainsaw. Also,
839 * it has no business starting mainloop(); it should connect, and be
842 * @param port the port where we will listen
844 void connectme(unsigned int port)
846 struct sockaddr_in addrin;
848 int addrinlen = sizeof(addrin);
849 int net, sock, newpid, i;
863 snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", port);
864 pidf=fopen(pidfname, "w");
866 fprintf(pidf,"%d", (int)getpid());
870 fprintf(stderr, "Not fatal; continuing");
874 #endif /* NODAEMON */
876 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
879 /* lose the pesky "Address already in use" error message */
880 if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
881 err("setsockopt SO_REUSEADDR");
883 if (setsockopt(sock,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
884 err("setsockopt SO_KEEPALIVE");
887 DEBUG("Waiting for connections... bind, ");
888 addrin.sin_family = AF_INET;
889 addrin.sin_port = htons(port);
890 addrin.sin_addr.s_addr = 0;
891 if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
894 if (listen(sock, 1) < 0)
897 sa.sa_handler = sigchld_handler;
898 sigemptyset(&sa.sa_mask);
899 sa.sa_flags = SA_RESTART;
900 if(sigaction(SIGCHLD, &sa, NULL) == -1)
901 err("sigaction: %m");
902 sa.sa_handler = sigterm_handler;
903 sigemptyset(&sa.sa_mask);
904 sa.sa_flags = SA_RESTART;
905 if(sigaction(SIGTERM, &sa, NULL) == -1)
906 err("sigaction: %m");
907 children=malloc(sizeof(pid_t)*child_arraysize);
908 memset(children, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
909 for(;;) { /* infinite loop */
910 if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
913 set_peername(net,clientname);
914 if (!authorized_client(clientname)) {
915 msg2(LOG_INFO,"Unauthorized client") ;
919 msg2(LOG_INFO,"Authorized client") ;
920 for(i=0;children[i]&&i<child_arraysize;i++);
921 if(i>=child_arraysize) {
924 ptr=realloc(children, sizeof(pid_t)*child_arraysize);
927 memset(children+child_arraysize, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
929 child_arraysize+=DEFAULT_CHILD_ARRAY;
931 msg2(LOG_INFO,"Not enough memory to store child PID");
937 if ((children[i]=fork())<0) {
938 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
942 if (children[i]>0) { /* parent */
943 close(net) ; continue ; }
949 msg2(LOG_INFO,"Starting to serve") ;
950 serveconnection(net) ;
955 * Main entry point...
957 int main(int argc, char *argv[])
959 if (sizeof( struct nbd_request )!=28) {
960 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
968 /* You really should define ISSERVER if you're going to use inetd
969 * mode, but if you don't, closing stdout and stderr (which inetd
970 * had connected to the client socket) will let it work. */
973 open("/dev/null", O_WRONLY);
974 open("/dev/null", O_WRONLY);
976 set_peername(0,clientname);
980 connectme(port); /* serve infinitely */