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>
84 /* used in cliserv.h, so must come first */
85 #define MY_NAME "nbd_server"
88 /** how much space for child PIDs we have by default. Dynamically
89 allocated, and will be realloc()ed if out of space, so this should
90 probably be fair for most situations. */
91 #define DEFAULT_CHILD_ARRAY 256
93 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */
95 #define msg2(a,b) syslog(a,"%s", b)
96 #define msg3(a,b,c) syslog(a,"%s %s", b,c)
97 #define msg4(a,b,c,d) syslog(a,"%s %s %s", b,c,d)
99 #define msg2(a,b) do { fprintf(stderr,"%s\n", b) ; } while(0)
100 #define msg3(a,b,c) do { fprintf(stderr,"%s %s\n", b,c); } while(0)
101 #define msg4(a,b,c,d) do { fprintf(stderr,"%s %s %s\n", b,c,d); } while(0)
104 /* Debugging macros */
107 #define DEBUG( a ) printf( a )
108 #define DEBUG2( a,b ) printf( a,b )
109 #define DEBUG3( a,b,c ) printf( a,b,c )
112 #define DEBUG2( a,b )
113 #define DEBUG3( a,b,c )
115 #ifndef PACKAGE_VERSION
116 #define PACKAGE_VERSION ""
119 * The highest value a variable of type off_t can reach.
121 /* This is starting to get ugly. If someone knows a better way to find
122 * the maximum value of a signed type *without* relying on overflow
123 * (doing so breaks on 64bit architectures), that would be nice.
125 #define OFFT_MAX (((((off_t)1)<<((sizeof(off_t)-1)*8))-1)<<7)+127
126 #define LINELEN 256 /**< Size of static buffer used to read the
127 authorization file (yuck) */
128 #define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */
129 #define GIGA (1*1024*1024*1024) /**< 1 Gigabyte. Used as hunksize when doing
130 the multiple file thingy */
131 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
132 #define F_READONLY 1 /**< flag to tell us a file is readonly */
133 #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
134 #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using copyonwrite */
135 char difffilename[1024]; /**< filename of the copy-on-write file. Doesn't belong here! */
136 unsigned int timeout = 0; /**< disconnect timeout */
137 int autoreadonly = 0; /**< 1 = switch to readonly if opening readwrite isn't
139 char *auth_file="nbd_server.allow"; /**< authorization file */
140 char exportname2[1024]; /**< File I'm exporting, with virtualhost resolved */
141 off_t lastpoint = (off_t)-1; /**< keep track of where we are in the file, to
142 avoid an lseek if possible */
143 char pagebuf[DIFFPAGESIZE]; /**< when doing copyonwrite, this is
144 used as a temporary buffer to store
145 the exported block in. @todo this is
146 a great example of namespace
147 pollution. Throw it out. */
148 unsigned int port; /**< Port I'm listening at */
149 char *exportname; /**< File I'm exporting */
150 off_t exportsize = OFFT_MAX; /**< length of file I'm exporting */
151 off_t hunksize = OFFT_MAX; /**< size of each exported file in case of -m */
152 int flags = 0; /**< flags associated with this exported file */
153 int export[1024];/**< array of filedescriptors of exported files; only first is
154 used unless -m option is activated */
155 int difffile=-1; /**< filedescriptor for copyonwrite file */
156 u32 difffilelen=0 ; /**< number of pages in difffile */
157 u32 *difmap=NULL ; /**< Determine whether a block is in the original file
158 (difmap[block]==-1) or in the copyonwrite file (in which
159 case it contains the offset where it is to be found in the
160 copyonwrite file). @todo the kernel knows about sparse
161 files, we should use those instead. Should also be off_t
162 instead of u32; copyonwrite is probably broken wrt LFS */
163 char clientname[256] ;
164 int child_arraysize=DEFAULT_CHILD_ARRAY; /**< number of available slots for
166 pid_t *children; /**< child array */
167 char pidfname[256]; /**< name of our PID file */
170 * Variables associated with a copyonwrite server. Not yet used.
173 char* difffilename; /**< filename of the copy-on-write file */
174 int difffile; /**< filedescriptor of copyonwrite file. @todo
175 shouldn't this be an array too? (cfr
176 nbd_server_opts::export) Or make -m and -c
177 mutually exclusive */
178 u32 difffilelen; /**< number of pages in difffile */
179 u32 *difmap; /**< see comment on the global difmap for this one */
183 * Variables associated with a server. Not yet used. @todo modify the code to
184 * use an instance of this struct instead of the heap of global variables.
187 char* exportname; /**< filename of the file we're exporting */
188 unsigned int port; /**< port we're exporting this file at */
189 char* authname; /**< filename of the authorization file */
190 off_t exportsize; /**< size of the file we're exporting */
191 off_t hunksize; /**< size of a hunk of an exported file */
192 int flags; /**< flags associated with this exported file */
193 char* clientname; /**< peer */
194 unsigned int timeout;/**< how long a connection may be idle
196 int export[1024]; /**< array of filedescriptors of exported files;
197 only the first is actually used unless we're
198 doing the multiple file option */
199 cow_opts* cow; /**< only used if (flags | F_COPYONWRITE) (NULL
204 * Check whether a client is allowed to connect. Works with an authorization
205 * file which contains one line per machine, no wildcards.
207 * @param name IP address of client trying to connect (in human-readable form)
208 * @return 0 - authorization refused, 1 - OK
210 int authorized_client(char *name)
216 if ((f=fopen(auth_file,"r"))==NULL) {
217 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
218 auth_file,strerror(errno)) ;
222 while (fgets(line,LINELEN,f)!=NULL) {
223 if (strncmp(line,name,strlen(name))==0) {
233 * Read data from a file descriptor into a buffer
235 * @param f a file descriptor
236 * @param buf a buffer
237 * @param len the number of bytes to be read
239 inline void readit(int f, void *buf, size_t len)
244 if ((res = read(f, buf, len)) <= 0)
245 err("Read failed: %m");
252 * Write data from a buffer into a filedescriptor
254 * @param f a file descriptor
255 * @param buf a buffer containing data
256 * @param len the number of bytes to be written
258 inline void writeit(int f, void *buf, size_t len)
263 if ((res = write(f, buf, len)) <= 0)
264 err("Send failed: %m");
271 * Parse the command line.
273 * @todo getopt() is a great thing, and easy to use. Also, we want to
274 * create a configuration file which nbd-server will read. Maybe do (as in,
277 * @param argc the argc argument to main()
278 * @param argv the argv argument to main()
280 void cmdline(int argc, char *argv[])
285 printf("This is nbd-server version " VERSION "\n");
286 printf("Usage: port file_to_export [size][kKmM] [-r] [-m] [-c] [-a timeout_sec]\n"
288 " -m multiple file\n"
289 " -c copy on write\n"
290 " -l file with list of hosts that are allowed to connect.\n"
291 " -a maximum idle seconds, terminates when idle time exceeded\n"
292 " if port is set to 0, stdin is used (for running from inetd)\n"
293 " if file_to_export contains '%%s', it is substituted with IP\n"
294 " address of machine trying to connect\n" );
297 port = atoi(argv[1]);
298 for (i = 3; i < argc; i++) {
299 if (*argv[i] == '-') {
300 switch (argv[i][1]) {
305 flags |= F_MULTIFILE;
308 case 'c': flags |=F_COPYONWRITE;
315 fprintf(stderr, "host list file requires an argument");
320 timeout = atoi(argv[i+1]);
323 fprintf(stderr, "timeout requires argument\n");
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]);
346 exportname = argv[2];
350 * Signal handler for SIGCHLD
351 * @param s the signal we're handling (must be SIGCHLD, or something
354 void sigchld_handler(int s)
361 while((pid=wait(status)) > 0) {
362 if(WIFEXITED(status)) {
363 memset(buf,'\0', 80);
364 snprintf(buf, 79, "%d", WEXITSTATUS(status));
365 msg3(LOG_INFO, "Child exited with ", buf);
367 for(i=0;children[i]!=pid&&i<child_arraysize;i++);
368 if(i>=child_arraysize) {
369 memset(buf, '\0', 80);
370 snprintf(buf, 79, "%ld", (long)pid);
371 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID ", buf);
373 children[i]=(pid_t)0;
374 DEBUG2("Removing %d from the list of children", pid);
380 * Handle SIGTERM and dispatch it to our children
381 * @param s the signal we're handling (must be SIGTERM, or something
382 * is severely wrong).
384 void sigterm_handler(int s) {
388 for(i=0;i<child_arraysize;i++) {
390 kill(children[i], s);
403 * Detect the size of a file.
405 * @param export An open filedescriptor
406 * @return the size of the file, or OFFT_MAX if detection was
409 off_t size_autodetect(int export)
413 struct stat stat_buf;
416 #ifdef HAVE_SYS_MOUNT_H
417 #ifdef HAVE_SYS_IOCTL_H
419 DEBUG("looking for export size with ioctl BLKGETSIZE\n");
420 if (!ioctl(export, BLKGETSIZE, &es32) && es32) {
421 es = (off_t)es32 * (off_t)512;
424 #endif /* BLKGETSIZE */
425 #endif /* HAVE_SYS_IOCTL_H */
426 #endif /* HAVE_SYS_MOUNT_H */
428 DEBUG("looking for export size with fstat\n");
429 stat_buf.st_size = 0;
430 error = fstat(export, &stat_buf);
431 if (!error && stat_buf.st_size > 0) {
432 return (off_t)stat_buf.st_size;
434 err("fstat failed: %m");
437 DEBUG("looking for export size with lseek SEEK_END\n");
438 es = lseek(export, (off_t)0, SEEK_END);
439 if (es > ((off_t)0)) {
442 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
445 err("Could not find size of exported block device: %m");
450 * Seek to a position in a file, unless we're already there.
451 * @param handle a filedescriptor
452 * @param a position to seek to
454 void maybeseek(int handle, off_t a) {
455 if (a < 0 || a > exportsize) {
456 err("Can not happen\n");
458 if (lastpoint != a) {
459 if (lseek(handle, a, SEEK_SET) < 0) {
460 err("Can not seek locally!\n");
469 * Write an amount of bytes at a given offset to the right file. This
470 * abstracts the write-side of the multiple file option.
472 * @param a The offset where the write should start
473 * @param buf The buffer to write from
474 * @param len The length of buf
475 * @return The number of bytes actually written, or -1 in case of an error
477 int rawexpwrite(off_t a, char *buf, size_t len)
481 maybeseek(export[a/hunksize], a%hunksize);
482 res = write(export[a/hunksize], buf, len);
483 return (res < 0 || (size_t)res != len);
487 * seek to a position in a file, no matter what. Used when using maybeseek is a
488 * bad idea (for instance, because we're reading the copyonwrite file instead
489 * of the exported file).
490 * @param handle a filedescriptor
491 * @param a position to seek to
492 * @todo get rid of this; lastpoint is a global variable right now, but it
493 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
496 void myseek(int handle,off_t a) {
497 if (lseek(handle, a, SEEK_SET) < 0) {
498 err("Can not seek locally!\n");
503 * Read an amount of bytes at a given offset from the right file. This
504 * abstracts the read-side of the multiple files option.
506 * @param a The offset where the read should start
507 * @param buf A buffer to read into
508 * @param len The size of buf
509 * @return The number of bytes actually read, or -1 in case of an
512 int rawexpread(off_t a, char *buf, size_t len)
516 maybeseek(export[a/hunksize], a%hunksize);
517 res = read(export[a/hunksize], buf, len);
518 return (res < 0 || (size_t)res != len);
522 * Read an amount of bytes at a given offset from the right file. This
523 * abstracts the read-side of the copyonwrite stuff, and calls
524 * rawexpread() with the right parameters to do the actual work.
525 * @param a The offset where the read should start
526 * @param buf A buffer to read into
527 * @param len The size of buf
528 * @return The number of bytes actually read, or -1 in case of an error
530 int expread(off_t a, char *buf, size_t len)
533 off_t mapcnt, mapl, maph, pagestart;
535 if (!(flags & F_COPYONWRITE))
536 return rawexpread(a, buf, len);
537 DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
539 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
541 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
542 pagestart=mapcnt*DIFFPAGESIZE;
544 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
545 len : (size_t)DIFFPAGESIZE-offset;
546 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
547 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
548 (unsigned long)difmap[mapcnt]);
549 myseek(difffile, difmap[mapcnt]*DIFFPAGESIZE+offset);
550 if (read(difffile, buf, rdlen) != rdlen) return -1;
551 } else { /* the block is not there */
552 DEBUG2("Page %Lu is not here, we read the original one\n",
553 (unsigned long long)mapcnt);
554 return rawexpread(a, buf, rdlen);
556 len-=rdlen; a+=rdlen; buf+=rdlen;
562 * Write an amount of bytes at a given offset to the right file. This
563 * abstracts the write-side of the copyonwrite option, and calls
564 * rawexpwrite() with the right parameters to do the actual work.
566 * @param a The offset where the write should start
567 * @param buf The buffer to write from
568 * @param len The length of buf
569 * @return The number of bytes actually written, or -1 in case of an error
571 int expwrite(off_t a, char *buf, size_t len)
573 off_t mapcnt,mapl,maph ;
578 if (!(flags & F_COPYONWRITE))
579 return(rawexpwrite(a,buf,len));
580 DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
582 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
584 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
585 pagestart=mapcnt*DIFFPAGESIZE ;
587 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
588 len : (size_t)DIFFPAGESIZE-offset;
590 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
591 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
592 (unsigned long)difmap[mapcnt]) ;
593 myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
594 if (write(difffile, buf, wrlen) != wrlen) return -1 ;
595 } else { /* the block is not there */
596 myseek(difffile,difffilelen*DIFFPAGESIZE) ;
597 difmap[mapcnt]=difffilelen++ ;
598 DEBUG3("Page %Lu is not here, we put it at %lu\n",
599 (unsigned long long)mapcnt,
600 (unsigned long)difmap[mapcnt]);
602 if (rdlen+pagestart%hunksize>hunksize)
603 rdlen=hunksize-(pagestart%hunksize) ;
604 if (rawexpread(pagestart,pagebuf,rdlen)) return -1 ;
605 memcpy(pagebuf+offset,buf,wrlen) ;
606 if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
608 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
614 * Do the initial negotiation.
616 * @param net A socket to do the negotiation over
618 void negotiate(int net) {
622 memset(zeros, 0, 290);
623 if (write(net, INIT_PASSWD, 8) < 0)
624 err("Negotiation failed: %m");
625 cliserv_magic = htonll(cliserv_magic);
626 if (write(net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
627 err("Negotiation failed: %m");
628 size_host = htonll((u64)exportsize);
629 if (write(net, &size_host, 8) < 0)
630 err("Negotiation failed: %m");
631 if (write(net, zeros, 128) < 0)
632 err("Negotiation failed: %m");
635 /** sending macro; not really required. Uses variables in the local
636 * scope of mainloop(). Get rid of it. */
637 #define SEND writeit( net, &reply, sizeof( reply ));
638 /** error macro; not sure whether we really need this. Uses variables
639 * in the local scope of mainloop(). Get rid of this beast. */
640 #define ERROR { reply.error = htonl(-1); SEND; reply.error = 0; lastpoint = -1; }
642 * Serve a file to a single client.
644 * @todo This beast needs to be split up in many tiny little manageable
645 * pieces. Preferably with a chainsaw.
647 * @param net A network socket, connected to an nbd client
650 int mainloop(int net)
652 struct nbd_request request;
653 struct nbd_reply reply;
658 DEBUG("Entering request loop!\n");
659 reply.magic = htonl(NBD_REPLY_MAGIC);
670 readit(net, &request, sizeof(request));
671 request.from = ntohll(request.from);
672 request.type = ntohl(request.type);
674 if (request.type==NBD_CMD_DISC) { /* Disconnect request */
675 if (difmap) free(difmap) ;
677 close(difffile) ; unlink(difffilename) ; }
678 err("Disconnect request received.") ;
681 len = ntohl(request.len);
683 if (request.magic != htonl(NBD_REQUEST_MAGIC))
684 err("Not enough magic.");
686 err("Request too big!");
688 printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
689 "READ", (unsigned long long)request.from,
690 (unsigned long long)request.from / 512, len);
692 memcpy(reply.handle, request.handle, sizeof(reply.handle));
693 if ((request.from + len) > (OFFT_MAX)) {
694 DEBUG("[Number too large!]");
699 if (((ssize_t)((off_t)request.from + len) > exportsize) ||
700 ((flags & F_READONLY) && request.type)) {
706 if (request.type==1) { /* WRITE */
707 DEBUG("wr: net->buf, ");
708 readit(net, buf, len);
710 if ((autoreadonly == 1) || expwrite(request.from, buf, len)) {
711 DEBUG("Write failed: %m" );
723 if (expread(request.from, buf + sizeof(struct nbd_reply), len)) {
725 DEBUG("Read failed: %m");
732 memcpy(buf, &reply, sizeof(struct nbd_reply));
733 writeit(net, buf, len + sizeof(struct nbd_reply));
739 * Split a single exportfile into multiple ones, if that was asked.
740 * @return 0 on success, -1 on failure
742 int splitexport(void) {
745 for (i=0; i<exportsize; i+=hunksize) {
746 char exportname3[1024];
748 if(flags & F_MULTIFILE) {
749 snprintf(exportname3, 1024, "%s.%d", exportname2, (int)(i/hunksize));
751 strncpy(exportname3, exportname2, 1024);
753 exportname3[1023]='\0';
754 printf( "Opening %s\n", exportname3 );
755 if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) {
756 /* Read WRITE ACCESS was requested by media is only read only */
759 if ((export[i/hunksize] = open(exportname3, O_RDONLY)) == -1)
760 err("Could not open exported file: %m");
764 if (flags & F_COPYONWRITE) {
765 snprintf(difffilename, 1024, "%s-%s-%d.diff",exportname2,clientname,
767 difffilename[1023]='\0';
768 msg3(LOG_INFO,"About to create map and diff file %s",difffilename) ;
769 difffile=open(difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
770 if (difffile<0) err("Could not create diff file (%m)") ;
771 if ((difmap=calloc(exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
772 err("Could not allocate memory") ;
773 for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
780 * Serve a connection.
782 * @todo allow for multithreading, perhaps use libevent.
784 * @param net A network socket connected to an nbd client
786 void serveconnection(int net) {
789 if (exportsize == OFFT_MAX) {
790 exportsize = size_autodetect(export[0]);
792 if (exportsize > OFFT_MAX) {
793 err("Size of exported file is too big\n");
796 memset(buf, '\0', 80);
797 snprintf(buf, 79, "%Lu", (unsigned long long)exportsize);
798 msg3(LOG_INFO, "size of exported file/device is ", buf);
807 * Find the name of the file we have to serve. This will use snprintf()
808 * to put the IP address of the client inside a filename containing
809 * "%s". That name is then written to exportname2
811 * @param net A socket connected to an nbd client
812 * @param clientname a buffer which must be at least 255+1 bytes long;
813 * the IP address (in human-readable format) will be copied in there.
815 void set_peername(int net,char *clientname)
817 struct sockaddr_in addrin;
818 int addrinlen = sizeof( addrin );
821 if (getpeername( net, (struct sockaddr *) &addrin, &addrinlen ) < 0)
822 err("getsockname failed: %m");
823 peername = inet_ntoa(addrin.sin_addr);
824 snprintf(exportname2, 1024, exportname, peername);
825 exportname2[1023]='\0';
827 msg4(LOG_INFO, "connect from %s, assigned file is %s",
828 peername, exportname2);
829 strncpy(clientname,peername,255) ;
833 * Connect the socket, and start to serve. This function will fork()
834 * if a connection from an authorized client is received, and will
837 * @todo modularize this giant beast. Preferably with a chainsaw. Also,
838 * it has no business starting mainloop(); it should connect, and be
841 * @param port the port where we will listen
843 void connectme(unsigned int port)
845 struct sockaddr_in addrin;
847 int addrinlen = sizeof(addrin);
848 int net, sock, newpid, i;
862 snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", port);
863 pidf=fopen(pidfname, "w");
865 fprintf(pidf,"%d", (int)getpid());
869 fprintf(stderr, "Not fatal; continuing");
873 #endif /* NODAEMON */
875 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
878 /* lose the pesky "Address already in use" error message */
879 if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
880 err("setsockopt SO_REUSEADDR");
882 if (setsockopt(sock,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
883 err("setsockopt SO_KEEPALIVE");
886 DEBUG("Waiting for connections... bind, ");
887 addrin.sin_family = AF_INET;
888 addrin.sin_port = htons(port);
889 addrin.sin_addr.s_addr = 0;
890 if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
893 if (listen(sock, 1) < 0)
896 sa.sa_handler = sigchld_handler;
897 sigemptyset(&sa.sa_mask);
898 sa.sa_flags = SA_RESTART;
899 if(sigaction(SIGCHLD, &sa, NULL) == -1)
900 err("sigaction: %m");
901 sa.sa_handler = sigterm_handler;
902 sigemptyset(&sa.sa_mask);
903 sa.sa_flags = SA_RESTART;
904 if(sigaction(SIGTERM, &sa, NULL) == -1)
905 err("sigaction: %m");
906 children=malloc(sizeof(pid_t)*child_arraysize);
907 memset(children, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
908 for(;;) { /* infinite loop */
909 if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
912 set_peername(net,clientname);
913 if (!authorized_client(clientname)) {
914 msg2(LOG_INFO,"Unauthorized client") ;
918 msg2(LOG_INFO,"Authorized client") ;
919 for(i=0;children[i]&&i<child_arraysize;i++);
920 if(i>=child_arraysize) {
923 ptr=realloc(children, sizeof(pid_t)*child_arraysize);
926 memset(children+child_arraysize, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
928 child_arraysize+=DEFAULT_CHILD_ARRAY;
930 msg2(LOG_INFO,"Not enough memory to store child PID");
936 if ((children[i]=fork())<0) {
937 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
941 if (children[i]>0) { /* parent */
942 close(net) ; continue ; }
948 msg2(LOG_INFO,"Starting to serve") ;
949 serveconnection(net) ;
954 * Main entry point...
956 int main(int argc, char *argv[])
958 if (sizeof( struct nbd_request )!=28) {
959 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
965 if (!port) return 1 ;
966 connectme(port); /* serve infinitely */