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 */
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>
83 /* used in cliserv.h, so must come first */
84 #define MY_NAME "nbd_server"
87 /** how much space for child PIDs we have by default. Dynamically
88 allocated, and will be realloc()ed if out of space, so this should
89 probably be fair for most situations. */
90 #define DEFAULT_CHILD_ARRAY 256
92 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */
94 #define msg2(a,b) syslog(a,"%s", b)
95 #define msg3(a,b,c) syslog(a,"%s %s", b,c)
96 #define msg4(a,b,c,d) syslog(a,"%s %s %s", b,c,d)
98 #define msg2(a,b) do { fprintf(stderr,"%s\n", b) ; } while(0)
99 #define msg3(a,b,c) do { fprintf(stderr,"%s %s\n", b,c); } while(0)
100 #define msg4(a,b,c,d) do { fprintf(stderr,"%s %s %s\n", b,c,d); } while(0)
103 /* Debugging macros */
106 #define DEBUG( a ) printf( a )
107 #define DEBUG2( a,b ) printf( a,b )
108 #define DEBUG3( a,b,c ) printf( a,b,c )
111 #define DEBUG2( a,b )
112 #define DEBUG3( a,b,c )
114 #ifndef PACKAGE_VERSION
115 #define PACKAGE_VERSION ""
118 * The highest value a variable of type off_t can reach.
120 /* This is starting to get ugly. If someone knows a better way to find
121 * the maximum value of a signed type *without* relying on overflow
122 * (doing so breaks on 64bit architectures), that would be nice.
124 #define OFFT_MAX (((((off_t)1)<<((sizeof(off_t)-1)*8))-1)<<7)+127
125 #define LINELEN 256 /**< Size of static buffer used to read the
126 authorization file (yuck) */
127 #define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */
128 #define GIGA (1*1024*1024*1024) /**< 1 Gigabyte. Used as hunksize when doing
129 the multiple file thingy */
130 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
131 #define F_READONLY 1 /**< flag to tell us a file is readonly */
132 #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
133 #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using copyonwrite */
134 char difffilename[1024]; /**< filename of the copy-on-write file. Doesn't belong here! */
135 unsigned int timeout = 0; /**< disconnect timeout */
136 int autoreadonly = 0; /**< 1 = switch to readonly if opening readwrite isn't
138 char *auth_file="nbd_server.allow"; /**< authorization file */
139 char exportname2[1024]; /**< File I'm exporting, with virtualhost resolved */
140 off_t lastpoint = (off_t)-1; /**< keep track of where we are in the file, to
141 avoid an lseek if possible */
142 char pagebuf[DIFFPAGESIZE]; /**< when doing copyonwrite, this is
143 used as a temporary buffer to store
144 the exported block in. @todo this is
145 a great example of namespace
146 pollution. Throw it out. */
147 unsigned int port; /**< Port I'm listening at */
148 char *exportname; /**< File I'm exporting */
149 off_t exportsize = OFFT_MAX; /**< length of file I'm exporting */
150 off_t hunksize = OFFT_MAX; /**< size of each exported file in case of -m */
151 int flags = 0; /**< flags associated with this exported file */
152 int export[1024];/**< array of filedescriptors of exported files; only first is
153 used unless -m option is activated */
154 int difffile=-1; /**< filedescriptor for copyonwrite file */
155 u32 difffilelen=0 ; /**< number of pages in difffile */
156 u32 *difmap=NULL ; /**< Determine whether a block is in the original file
157 (difmap[block]==-1) or in the copyonwrite file (in which
158 case it contains the offset where it is to be found in the
159 copyonwrite file). @todo the kernel knows about sparse
160 files, we should use those instead. Should also be off_t
161 instead of u32; copyonwrite is probably broken wrt LFS */
162 char clientname[256] ;
163 int child_arraysize=DEFAULT_CHILD_ARRAY; /**< number of available slots for
165 pid_t *children; /**< child array */
166 char pidfname[256]; /**< name of our PID file */
169 * Variables associated with a copyonwrite server. Not yet used.
172 char* difffilename; /**< filename of the copy-on-write file */
173 int difffile; /**< filedescriptor of copyonwrite file. @todo
174 shouldn't this be an array too? (cfr
175 nbd_server_opts::export) Or make -m and -c
176 mutually exclusive */
177 u32 difffilelen; /**< number of pages in difffile */
178 u32 *difmap; /**< see comment on the global difmap for this one */
182 * Variables associated with a server. Not yet used. @todo modify the code to
183 * use an instance of this struct instead of the heap of global variables.
186 char* exportname; /**< filename of the file we're exporting */
187 unsigned int port; /**< port we're exporting this file at */
188 char* authname; /**< filename of the authorization file */
189 off_t exportsize; /**< size of the file we're exporting */
190 off_t hunksize; /**< size of a hunk of an exported file */
191 int flags; /**< flags associated with this exported file */
192 char* clientname; /**< peer */
193 unsigned int timeout;/**< how long a connection may be idle
195 int export[1024]; /**< array of filedescriptors of exported files;
196 only the first is actually used unless we're
197 doing the multiple file option */
198 cow_opts* cow; /**< only used if (flags | F_COPYONWRITE) (NULL
203 * Check whether a client is allowed to connect. Works with an authorization
204 * file which contains one line per machine, no wildcards.
206 * @param name IP address of client trying to connect (in human-readable form)
207 * @return 0 - authorization refused, 1 - OK
209 int authorized_client(char *name)
215 if ((f=fopen(auth_file,"r"))==NULL) {
216 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
217 auth_file,strerror(errno)) ;
221 while (fgets(line,LINELEN,f)!=NULL) {
222 if (strncmp(line,name,strlen(name))==0) {
232 * Read data from a file descriptor into a buffer
234 * @param f a file descriptor
235 * @param buf a buffer
236 * @param len the number of bytes to be read
238 inline void readit(int f, void *buf, size_t len)
243 if ((res = read(f, buf, len)) <= 0)
244 err("Read failed: %m");
251 * Write data from a buffer into a filedescriptor
253 * @param f a file descriptor
254 * @param buf a buffer containing data
255 * @param len the number of bytes to be written
257 inline void writeit(int f, void *buf, size_t len)
262 if ((res = write(f, buf, len)) <= 0)
263 err("Send failed: %m");
270 * Parse the command line.
272 * @todo getopt() is a great thing, and easy to use. Also, we want to
273 * create a configuration file which nbd-server will read. Maybe do (as in,
276 * @param argc the argc argument to main()
277 * @param argv the argv argument to main()
279 void cmdline(int argc, char *argv[])
284 printf("This is nbd-server version " VERSION "\n");
285 printf("Usage: port file_to_export [size][kKmM] [-r] [-m] [-c] [-a timeout_sec]\n"
287 " -m multiple file\n"
288 " -c copy on write\n"
289 " -l file with list of hosts that are allowed to connect.\n"
290 " -a maximum idle seconds, terminates when idle time exceeded\n"
291 " if port is set to 0, stdin is used (for running from inetd)\n"
292 " if file_to_export contains '%%s', it is substituted with IP\n"
293 " address of machine trying to connect\n" );
296 port = atoi(argv[1]);
297 for (i = 3; i < argc; i++) {
298 if (*argv[i] == '-') {
299 switch (argv[i][1]) {
304 flags |= F_MULTIFILE;
307 case 'c': flags |=F_COPYONWRITE;
314 fprintf(stderr, "host list file requires an argument");
319 timeout = atoi(argv[i+1]);
322 fprintf(stderr, "timeout requires argument\n");
328 size_t last = strlen(argv[i])-1;
329 char suffix = argv[i][last];
330 if (suffix == 'k' || suffix == 'K' ||
331 suffix == 'm' || suffix == 'M')
332 argv[i][last] = '\0';
333 es = (off_t)atol(argv[i]);
345 exportname = argv[2];
349 * Signal handler for SIGCHLD
350 * @param s the signal we're handling (must be SIGCHLD, or something
353 void sigchld_handler(int s)
360 while((pid=wait(status)) > 0) {
361 if(WIFEXITED(status)) {
362 memset(buf,'\0', 80);
363 snprintf(buf, 79, "%d", WEXITSTATUS(status));
364 msg3(LOG_INFO, "Child exited with ", buf);
366 for(i=0;children[i]!=pid&&i<child_arraysize;i++);
367 if(i>=child_arraysize) {
368 memset(buf, '\0', 80);
369 snprintf(buf, 79, "%ld", (long)pid);
370 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID ", buf);
372 children[i]=(pid_t)0;
373 DEBUG2("Removing %d from the list of children", pid);
379 * Handle SIGTERM and dispatch it to our children
380 * @param s the signal we're handling (must be SIGTERM, or something
381 * is severely wrong).
383 void sigterm_handler(int s) {
387 for(i=0;i<child_arraysize;i++) {
389 kill(children[i], s);
402 * Detect the size of a file.
404 * @param export An open filedescriptor
405 * @return the size of the file, or OFFT_MAX if detection was
408 off_t size_autodetect(int export)
412 struct stat stat_buf;
415 #ifdef HAVE_SYS_MOUNT_H
416 #ifdef HAVE_SYS_IOCTL_H
418 DEBUG("looking for export size with ioctl BLKGETSIZE\n");
419 if (!ioctl(export, BLKGETSIZE, &es32) && es32) {
420 es = (off_t)es32 * (off_t)512;
423 #endif /* BLKGETSIZE */
424 #endif /* HAVE_SYS_IOCTL_H */
425 #endif /* HAVE_SYS_MOUNT_H */
427 DEBUG("looking for export size with fstat\n");
428 stat_buf.st_size = 0;
429 error = fstat(export, &stat_buf);
430 if (!error && stat_buf.st_size > 0) {
431 return (off_t)stat_buf.st_size;
433 err("fstat failed: %m");
436 DEBUG("looking for export size with lseek SEEK_END\n");
437 es = lseek(export, (off_t)0, SEEK_END);
438 if (es > ((off_t)0)) {
441 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
444 err("Could not find size of exported block device: %m");
449 * Seek to a position in a file, unless we're already there.
450 * @param handle a filedescriptor
451 * @param a position to seek to
453 void maybeseek(int handle, off_t a) {
454 if (a < 0 || a > exportsize) {
455 err("Can not happen\n");
457 if (lastpoint != a) {
458 if (lseek(handle, a, SEEK_SET) < 0) {
459 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)
480 maybeseek(export[a/hunksize], a%hunksize);
481 res = write(export[a/hunksize], buf, len);
482 return (res < 0 || (size_t)res != len);
486 * seek to a position in a file, no matter what. Used when using maybeseek is a
487 * bad idea (for instance, because we're reading the copyonwrite file instead
488 * of the exported file).
489 * @param handle a filedescriptor
490 * @param a position to seek to
491 * @todo get rid of this; lastpoint is a global variable right now, but it
492 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
495 void myseek(int handle,off_t a) {
496 if (lseek(handle, a, SEEK_SET) < 0) {
497 err("Can not seek locally!\n");
502 * Read an amount of bytes at a given offset from the right file. This
503 * abstracts the read-side of the multiple files option.
505 * @param a The offset where the read should start
506 * @param buf A buffer to read into
507 * @param len The size of buf
508 * @return The number of bytes actually read, or -1 in case of an
511 int rawexpread(off_t a, char *buf, size_t len)
515 maybeseek(export[a/hunksize], a%hunksize);
516 res = read(export[a/hunksize], buf, len);
517 return (res < 0 || (size_t)res != len);
521 * Read an amount of bytes at a given offset from the right file. This
522 * abstracts the read-side of the copyonwrite stuff, and calls
523 * rawexpread() with the right parameters to do the actual work.
524 * @param a The offset where the read should start
525 * @param buf A buffer to read into
526 * @param len The size of buf
527 * @return The number of bytes actually read, or -1 in case of an error
529 int expread(off_t a, char *buf, size_t len)
532 off_t mapcnt, mapl, maph, pagestart;
534 if (!(flags & F_COPYONWRITE))
535 return rawexpread(a, buf, len);
536 DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
538 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
540 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
541 pagestart=mapcnt*DIFFPAGESIZE;
543 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
544 len : (size_t)DIFFPAGESIZE-offset;
545 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
546 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
547 (unsigned long)difmap[mapcnt]);
548 myseek(difffile, difmap[mapcnt]*DIFFPAGESIZE+offset);
549 if (read(difffile, buf, rdlen) != rdlen) return -1;
550 } else { /* the block is not there */
551 DEBUG2("Page %Lu is not here, we read the original one\n",
552 (unsigned long long)mapcnt);
553 return rawexpread(a, buf, rdlen);
555 len-=rdlen; a+=rdlen; buf+=rdlen;
561 * Write an amount of bytes at a given offset to the right file. This
562 * abstracts the write-side of the copyonwrite option, and calls
563 * rawexpwrite() with the right parameters to do the actual work.
565 * @param a The offset where the write should start
566 * @param buf The buffer to write from
567 * @param len The length of buf
568 * @return The number of bytes actually written, or -1 in case of an error
570 int expwrite(off_t a, char *buf, size_t len)
572 off_t mapcnt,mapl,maph ;
577 if (!(flags & F_COPYONWRITE))
578 return(rawexpwrite(a,buf,len));
579 DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
581 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
583 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
584 pagestart=mapcnt*DIFFPAGESIZE ;
586 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
587 len : (size_t)DIFFPAGESIZE-offset;
589 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
590 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
591 (unsigned long)difmap[mapcnt]) ;
592 myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
593 if (write(difffile, buf, wrlen) != wrlen) return -1 ;
594 } else { /* the block is not there */
595 myseek(difffile,difffilelen*DIFFPAGESIZE) ;
596 difmap[mapcnt]=difffilelen++ ;
597 DEBUG3("Page %Lu is not here, we put it at %lu\n",
598 (unsigned long long)mapcnt,
599 (unsigned long)difmap[mapcnt]);
601 if (rdlen+pagestart%hunksize>hunksize)
602 rdlen=hunksize-(pagestart%hunksize) ;
603 if (rawexpread(pagestart,pagebuf,rdlen)) return -1 ;
604 memcpy(pagebuf+offset,buf,wrlen) ;
605 if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
607 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
613 * Do the initial negotiation.
615 * @param net A socket to do the negotiation over
617 void negotiate(int net) {
621 memset(zeros, 0, 290);
622 if (write(net, INIT_PASSWD, 8) < 0)
623 err("Negotiation failed: %m");
624 cliserv_magic = htonll(cliserv_magic);
625 if (write(net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
626 err("Negotiation failed: %m");
627 size_host = htonll((u64)exportsize);
628 if (write(net, &size_host, 8) < 0)
629 err("Negotiation failed: %m");
630 if (write(net, zeros, 128) < 0)
631 err("Negotiation failed: %m");
634 /** sending macro; not really required. Uses variables in the local
635 * scope of mainloop(). Get rid of it. */
636 #define SEND writeit( net, &reply, sizeof( reply ));
637 /** error macro; not sure whether we really need this. Uses variables
638 * in the local scope of mainloop(). Get rid of this beast. */
639 #define ERROR { reply.error = htonl(-1); SEND; reply.error = 0; lastpoint = -1; }
641 * Serve a file to a single client.
643 * @todo This beast needs to be split up in many tiny little manageable
644 * pieces. Preferably with a chainsaw.
646 * @param net A network socket, connected to an nbd client
649 int mainloop(int net)
651 struct nbd_request request;
652 struct nbd_reply reply;
657 DEBUG("Entering request loop!\n");
658 reply.magic = htonl(NBD_REPLY_MAGIC);
669 readit(net, &request, sizeof(request));
670 request.from = ntohll(request.from);
671 request.type = ntohl(request.type);
673 if (request.type==NBD_CMD_DISC) { /* Disconnect request */
674 if (difmap) free(difmap) ;
676 close(difffile) ; unlink(difffilename) ; }
677 err("Disconnect request received.") ;
680 len = ntohl(request.len);
682 if (request.magic != htonl(NBD_REQUEST_MAGIC))
683 err("Not enough magic.");
685 err("Request too big!");
687 printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
688 "READ", (unsigned long long)request.from,
689 (unsigned long long)request.from / 512, len);
691 memcpy(reply.handle, request.handle, sizeof(reply.handle));
692 if ((request.from + len) > (OFFT_MAX)) {
693 DEBUG("[Number too large!]");
698 if (((ssize_t)((off_t)request.from + len) > exportsize) ||
699 ((flags & F_READONLY) && request.type)) {
705 if (request.type==1) { /* WRITE */
706 DEBUG("wr: net->buf, ");
707 readit(net, buf, len);
709 if ((autoreadonly == 1) || expwrite(request.from, buf, len)) {
710 DEBUG("Write failed: %m" );
722 if (expread(request.from, buf + sizeof(struct nbd_reply), len)) {
724 DEBUG("Read failed: %m");
731 memcpy(buf, &reply, sizeof(struct nbd_reply));
732 writeit(net, buf, len + sizeof(struct nbd_reply));
738 * Split a single exportfile into multiple ones, if that was asked.
739 * @return 0 on success, -1 on failure
741 int splitexport(void) {
744 for (i=0; i<exportsize; i+=hunksize) {
745 char exportname3[1024];
747 snprintf(exportname3, 1024, "%s.%d", exportname2, (int)(i/hunksize));
748 exportname3[1023]='\0';
749 printf( "Opening %s\n", exportname3 );
750 if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) {
751 /* Read WRITE ACCESS was requested by media is only read only */
754 if ((export[i/hunksize] = open(exportname3, O_RDONLY)) == -1)
755 err("Could not open exported file: %m");
759 if (flags & F_COPYONWRITE) {
760 snprintf(difffilename, 1024, "%s-%s-%d.diff",exportname2,clientname,
762 difffilename[1023]='\0';
763 msg3(LOG_INFO,"About to create map and diff file %s",difffilename) ;
764 difffile=open(difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
765 if (difffile<0) err("Could not create diff file (%m)") ;
766 if ((difmap=calloc(exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
767 err("Could not allocate memory") ;
768 for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
775 * Serve a connection.
777 * @todo allow for multithreading, perhaps use libevent.
779 * @param net A network socket connected to an nbd client
781 void serveconnection(int net) {
784 if (exportsize == OFFT_MAX) {
785 exportsize = size_autodetect(export[0]);
787 if (exportsize > OFFT_MAX) {
788 err("Size of exported file is too big\n");
791 memset(buf, '\0', 80);
792 snprintf(buf, 79, "%Lu", (unsigned long long)exportsize);
793 msg3(LOG_INFO, "size of exported file/device is ", buf);
802 * Find the name of the file we have to serve. This will use snprintf()
803 * to put the IP address of the client inside a filename containing
804 * "%s". That name is then written to exportname2
806 * @param net A socket connected to an nbd client
807 * @param clientname a buffer which must be at least 255+1 bytes long;
808 * the IP address (in human-readable format) will be copied in there.
810 void set_peername(int net,char *clientname)
812 struct sockaddr_in addrin;
813 int addrinlen = sizeof( addrin );
816 if (getpeername( net, (struct sockaddr *) &addrin, &addrinlen ) < 0)
817 err("getsockname failed: %m");
818 peername = inet_ntoa(addrin.sin_addr);
819 snprintf(exportname2, 1024, exportname, peername);
820 exportname2[1023]='\0';
822 msg4(LOG_INFO, "connect from %s, assigned file is %s",
823 peername, exportname2);
824 strncpy(clientname,peername,255) ;
828 * Connect the socket, and start to serve. This function will fork()
829 * if a connection from an authorized client is received, and will
832 * @todo modularize this giant beast. Preferably with a chainsaw. Also,
833 * it has no business starting mainloop(); it should connect, and be
836 * @param port the port where we will listen
838 void connectme(unsigned int port)
840 struct sockaddr_in addrin;
842 int addrinlen = sizeof(addrin);
843 int net, sock, newpid, i;
857 snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", port);
858 pidf=fopen(pidfname, "w");
860 fprintf(pidf,"%d", (int)getpid());
864 fprintf(stderr, "Not fatal; continuing");
868 #endif /* NODAEMON */
870 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
873 /* lose the pesky "Address already in use" error message */
874 if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
875 err("setsockopt SO_REUSEADDR");
877 if (setsockopt(sock,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
878 err("setsockopt SO_KEEPALIVE");
881 DEBUG("Waiting for connections... bind, ");
882 addrin.sin_family = AF_INET;
883 addrin.sin_port = htons(port);
884 addrin.sin_addr.s_addr = 0;
885 if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
888 if (listen(sock, 1) < 0)
891 sa.sa_handler = sigchld_handler;
892 sigemptyset(&sa.sa_mask);
893 sa.sa_flags = SA_RESTART;
894 if(sigaction(SIGCHLD, &sa, NULL) == -1)
895 err("sigaction: %m");
896 sa.sa_handler = sigterm_handler;
897 sigemptyset(&sa.sa_mask);
898 sa.sa_flags = SA_RESTART;
899 if(sigaction(SIGTERM, &sa, NULL) == -1)
900 err("sigaction: %m");
901 children=malloc(sizeof(pid_t)*child_arraysize);
902 memset(children, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
903 for(;;) { /* infinite loop */
904 if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
907 set_peername(net,clientname);
908 if (!authorized_client(clientname)) {
909 msg2(LOG_INFO,"Unauthorized client") ;
913 msg2(LOG_INFO,"Authorized client") ;
914 for(i=0;children[i]&&i<child_arraysize;i++);
915 if(i>=child_arraysize) {
918 ptr=realloc(children, sizeof(pid_t)*child_arraysize);
921 memset(children+child_arraysize, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
923 child_arraysize+=DEFAULT_CHILD_ARRAY;
925 msg2(LOG_INFO,"Not enough memory to store child PID");
931 if ((children[i]=fork())<0) {
932 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
936 if (children[i]>0) { /* parent */
937 close(net) ; continue ; }
943 msg2(LOG_INFO,"Starting to serve") ;
944 serveconnection(net) ;
949 * Main entry point...
951 int main(int argc, char *argv[])
953 if (sizeof( struct nbd_request )!=28) {
954 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
960 if (!port) return 1 ;
961 connectme(port); /* serve infinitely */