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 /* used in cliserv.h, so must come first */
55 #define MY_NAME "nbd_server"
56 /* Includes LFS defines, which defines behaviours of some of the following
57 * headers, so must come before those */
60 #include <sys/types.h>
61 #include <sys/socket.h>
63 #include <sys/wait.h> /* wait */
64 #include <sys/ioctl.h>
65 #include <sys/param.h>
66 #include <sys/mount.h> /* For BLKGETSIZE */
67 #include <signal.h> /* sigaction */
68 #include <netinet/tcp.h>
69 #include <netinet/in.h> /* sockaddr_in, htons, in_addr */
70 #include <netdb.h> /* hostent, gethostby*, getservby* */
77 #include <arpa/inet.h>
81 /** how much space for child PIDs we have by default. Dynamically
82 allocated, and will be realloc()ed if out of space, so this should
83 probably be fair for most situations. */
84 #define DEFAULT_CHILD_ARRAY 256
86 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */
88 #define msg2(a,b) syslog(a,b)
89 #define msg3(a,b,c) syslog(a,b,c)
90 #define msg4(a,b,c,d) syslog(a,b,c,d)
92 #define msg2(a,b) do { fprintf(stderr,b) ; fputs("\n",stderr) ; } while(0)
93 #define msg3(a,b,c) do { fprintf(stderr,b,c); fputs("\n",stderr) ; } while(0)
94 #define msg4(a,b,c,d) do { fprintf(stderr,b,c,d); fputs("\n",stderr) ; } while(0)
97 /* Debugging macros */
100 #define DEBUG( a ) printf( a )
101 #define DEBUG2( a,b ) printf( a,b )
102 #define DEBUG3( a,b,c ) printf( a,b,c )
105 #define DEBUG2( a,b )
106 #define DEBUG3( a,b,c )
108 #ifndef PACKAGE_VERSION
109 #define PACKAGE_VERSION ""
112 * The highest value a variable of type off_t can reach.
114 /* This is starting to get ugly. If someone knows a better way to find
115 * the maximum value of a signed type *without* relying on overflow
116 * (doing so breaks on 64bit architectures), that would be nice.
118 #define OFFT_MAX (((((off_t)1)<<((sizeof(off_t)-1)*8))-1)<<7)+127
119 #define LINELEN 256 /**< Size of static buffer used to read the
120 authorization file (yuck) */
121 #define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */
122 #define GIGA (1*1024*1024*1024) /**< 1 Gigabyte. Used as hunksize when doing
123 the multiple file thingy */
124 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
125 #define F_READONLY 1 /**< flag to tell us a file is readonly */
126 #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
127 #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using copyonwrite */
128 char difffilename[256]; /**< filename of the copy-on-write file. Doesn't belong here! */
129 unsigned int timeout = 0; /**< disconnect timeout */
130 int autoreadonly = 0; /**< 1 = switch to readonly if opening readwrite isn't
132 char *auth_file="nbd_server.allow"; /**< authorization file */
133 char exportname2[1024]; /**< File I'm exporting, with virtualhost resolved */
134 off_t lastpoint = (off_t)-1; /**< keep track of where we are in the file, to
135 avoid an lseek if possible */
136 char pagebuf[DIFFPAGESIZE]; /**< when doing copyonwrite, this is
137 used as a temporary buffer to store
138 the exported block in. @todo this is
139 a great example of namespace
140 pollution. Throw it out. */
141 unsigned int port; /**< Port I'm listening at */
142 char *exportname; /**< File I'm exporting */
143 off_t exportsize = OFFT_MAX; /**< length of file I'm exporting */
144 off_t hunksize = OFFT_MAX; /**< size of each exported file in case of -m */
145 int flags = 0; /**< flags associated with this exported file */
146 int export[1024];/**< array of filedescriptors of exported files; only first is
147 used unless -m option is activated */
148 int difffile=-1; /**< filedescriptor for copyonwrite file */
149 u32 difffilelen=0 ; /**< number of pages in difffile */
150 u32 *difmap=NULL ; /**< Determine whether a block is in the original file
151 (difmap[block]==-1) or in the copyonwrite file (in which
152 case it contains the offset where it is to be found in the
153 copyonwrite file). @todo the kernel knows about sparse
154 files, we should use those instead. Should also be off_t
155 instead of u32; copyonwrite is probably broken wrt LFS */
156 char clientname[256] ;
157 int child_arraysize=DEFAULT_CHILD_ARRAY; /**< number of available slots for
159 pid_t *children; /**< child array */
160 char pidfname[256]; /**< name of our PID file */
163 * Variables associated with a copyonwrite server. Not yet used.
166 char* difffilename; /**< filename of the copy-on-write file */
167 int difffile; /**< filedescriptor of copyonwrite file. @todo
168 shouldn't this be an array too? (cfr
169 nbd_server_opts::export) Or make -m and -c
170 mutually exclusive */
171 u32 difffilelen; /**< number of pages in difffile */
172 u32 *difmap; /**< see comment on the global difmap for this one */
176 * Variables associated with a server. Not yet used. @todo modify the code to
177 * use an instance of this struct instead of the heap of global variables.
180 char* exportname; /**< filename of the file we're exporting */
181 unsigned int port; /**< port we're exporting this file at */
182 char* authname; /**< filename of the authorization file */
183 off_t exportsize; /**< size of the file we're exporting */
184 off_t hunksize; /**< size of a hunk of an exported file */
185 int flags; /**< flags associated with this exported file */
186 char* clientname; /**< peer */
187 unsigned int timeout;/**< how long a connection may be idle
189 int export[1024]; /**< array of filedescriptors of exported files;
190 only the first is actually used unless we're
191 doing the multiple file option */
192 cow_opts* cow; /**< only used if (flags | F_COPYONWRITE) (NULL
197 * Check whether a client is allowed to connect. Works with an authorization
198 * file which contains one line per machine, no wildcards.
200 * @param name IP address of client trying to connect (in human-readable form)
201 * @return 0 - authorization refused, 1 - OK
203 int authorized_client(char *name)
209 if ((f=fopen(auth_file,"r"))==NULL) {
210 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
211 auth_file,strerror(errno)) ;
215 while (fgets(line,LINELEN,f)!=NULL) {
216 if (strncmp(line,name,strlen(name))==0) {
226 * Read data from a file descriptor into a buffer
228 * @param f a file descriptor
229 * @param buf a buffer
230 * @param len the number of bytes to be read
232 inline void readit(int f, void *buf, size_t len)
237 if ((res = read(f, buf, len)) <= 0)
238 err("Read failed: %m");
245 * Write data from a buffer into a filedescriptor
247 * @param f a file descriptor
248 * @param buf a buffer containing data
249 * @param len the number of bytes to be written
251 inline void writeit(int f, void *buf, size_t len)
256 if ((res = write(f, buf, len)) <= 0)
257 err("Send failed: %m");
264 * Parse the command line.
266 * @todo getopt() is a great thing, and easy to use. Also, we want to
267 * create a configuration file which nbd-server will read. Maybe do (as in,
270 * @param argc the argc argument to main()
271 * @param argv the argv argument to main()
273 void cmdline(int argc, char *argv[])
278 printf("This is nbd-server version " VERSION "\n");
279 printf("Usage: port file_to_export [size][kKmM] [-r] [-m] [-c] [-a timeout_sec]\n"
281 " -m multiple file\n"
282 " -c copy on write\n"
283 " -l file with list of hosts that are allowed to connect.\n"
284 " -a maximum idle seconds, terminates when idle time exceeded\n"
285 " if port is set to 0, stdin is used (for running from inetd)\n"
286 " if file_to_export contains '%%s', it is substituted with IP\n"
287 " address of machine trying to connect\n" );
290 port = atoi(argv[1]);
291 for (i = 3; i < argc; i++) {
292 if (*argv[i] == '-') {
293 switch (argv[i][1]) {
298 flags |= F_MULTIFILE;
301 case 'c': flags |=F_COPYONWRITE;
308 fprintf(stderr, "host list file requires an argument");
313 timeout = atoi(argv[i+1]);
316 fprintf(stderr, "timeout requires argument\n");
322 size_t last = strlen(argv[i])-1;
323 char suffix = argv[i][last];
324 if (suffix == 'k' || suffix == 'K' ||
325 suffix == 'm' || suffix == 'M')
326 argv[i][last] = '\0';
327 es = (off_t)atol(argv[i]);
339 exportname = argv[2];
343 * Signal handler for SIGCHLD
344 * @param s the signal we're handling (must be SIGCHLD, or something
347 void sigchld_handler(int s)
353 while((pid=wait(status)) > 0) {
354 if(WIFEXITED(status)) {
355 msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status));
357 for(i=0;children[i]!=pid&&i<child_arraysize;i++);
358 if(i>=child_arraysize) {
359 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld",(long) pid);
361 children[i]=(pid_t)0;
362 DEBUG2("Removing %d from the list of children", pid);
368 * Handle SIGTERM and dispatch it to our children
369 * @param s the signal we're handling (must be SIGTERM, or something
370 * is severely wrong).
372 void sigterm_handler(int s) {
376 for(i=0;i<child_arraysize;i++) {
378 kill(children[i], s);
391 * Detect the size of a file.
393 * @param export An open filedescriptor
394 * @return the size of the file, or OFFT_MAX if detection was
397 off_t size_autodetect(int export)
401 struct stat stat_buf;
404 DEBUG("looking for export size with lseek SEEK_END\n");
405 es = lseek(export, (off_t)0, SEEK_END);
406 if (es > ((off_t)0)) {
409 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
412 DEBUG("looking for export size with fstat\n");
413 stat_buf.st_size = 0;
414 error = fstat(export, &stat_buf);
415 if (!error && stat_buf.st_size > 0) {
416 return (off_t)stat_buf.st_size;
418 err("fstat failed: %m");
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;
428 err("Could not find size of exported block device: %m");
433 * Seek to a position in a file, unless we're already there.
434 * @param handle a filedescriptor
435 * @param a position to seek to
437 void maybeseek(int handle, off_t a) {
438 if (a < 0 || a > exportsize) {
439 err("Can not happen\n");
441 if (lastpoint != a) {
442 if (lseek(handle, a, SEEK_SET) < 0) {
443 err("Can not seek locally!\n");
452 * Write an amount of bytes at a given offset to the right file. This
453 * abstracts the write-side of the multiple file option.
455 * @param a The offset where the write should start
456 * @param buf The buffer to write from
457 * @param len The length of buf
458 * @return The number of bytes actually written, or -1 in case of an error
460 int rawexpwrite(off_t a, char *buf, size_t len)
464 maybeseek(export[a/hunksize], a%hunksize);
465 res = write(export[a/hunksize], buf, len);
466 return (res < 0 || (size_t)res != len);
470 * seek to a position in a file, no matter what. Used when using maybeseek is a
471 * bad idea (for instance, because we're reading the copyonwrite file instead
472 * of the exported file).
473 * @param handle a filedescriptor
474 * @param a position to seek to
475 * @todo get rid of this; lastpoint is a global variable right now, but it
476 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
479 void myseek(int handle,off_t a) {
480 if (lseek(handle, a, SEEK_SET) < 0) {
481 err("Can not seek locally!\n");
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)
499 maybeseek(export[a/hunksize], a%hunksize);
500 res = read(export[a/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)
516 off_t mapcnt, mapl, maph, pagestart;
518 if (!(flags & F_COPYONWRITE))
519 return rawexpread(a, buf, len);
520 DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
522 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
524 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
525 pagestart=mapcnt*DIFFPAGESIZE;
527 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
528 len : (size_t)DIFFPAGESIZE-offset;
529 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
530 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
531 (unsigned long)difmap[mapcnt]);
532 myseek(difffile, difmap[mapcnt]*DIFFPAGESIZE+offset);
533 if (read(difffile, buf, rdlen) != rdlen) return -1;
534 } else { /* the block is not there */
535 DEBUG2("Page %Lu is not here, we read the original one\n",
536 (unsigned long long)mapcnt);
537 return rawexpread(a, buf, rdlen);
539 len-=rdlen; a+=rdlen; buf+=rdlen;
545 * Write an amount of bytes at a given offset to the right file. This
546 * abstracts the write-side of the copyonwrite option, and calls
547 * rawexpwrite() with the right parameters to do the actual work.
549 * @param a The offset where the write should start
550 * @param buf The buffer to write from
551 * @param len The length of buf
552 * @return The number of bytes actually written, or -1 in case of an error
554 int expwrite(off_t a, char *buf, size_t len)
556 off_t mapcnt,mapl,maph ;
561 if (!(flags & F_COPYONWRITE))
562 return(rawexpwrite(a,buf,len));
563 DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
565 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
567 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
568 pagestart=mapcnt*DIFFPAGESIZE ;
570 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
571 len : (size_t)DIFFPAGESIZE-offset;
573 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
574 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
575 (unsigned long)difmap[mapcnt]) ;
576 myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
577 if (write(difffile, buf, wrlen) != wrlen) return -1 ;
578 } else { /* the block is not there */
579 myseek(difffile,difffilelen*DIFFPAGESIZE) ;
580 difmap[mapcnt]=difffilelen++ ;
581 DEBUG3("Page %Lu is not here, we put it at %lu\n",
582 (unsigned long long)mapcnt,
583 (unsigned long)difmap[mapcnt]);
585 if (rdlen+pagestart%hunksize>hunksize)
586 rdlen=hunksize-(pagestart%hunksize) ;
587 if (rawexpread(pagestart,pagebuf,rdlen)) return -1 ;
588 memcpy(pagebuf+offset,buf,wrlen) ;
589 if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
591 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
597 * Do the initial negotiation.
599 * @param net A socket to do the negotiation over
601 void negotiate(int net) {
605 memset(zeros, 0, 290);
606 if (write(net, INIT_PASSWD, 8) < 0)
607 err("Negotiation failed: %m");
608 cliserv_magic = htonll(cliserv_magic);
609 if (write(net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
610 err("Negotiation failed: %m");
611 size_host = htonll((u64)exportsize);
612 if (write(net, &size_host, 8) < 0)
613 err("Negotiation failed: %m");
614 if (write(net, zeros, 128) < 0)
615 err("Negotiation failed: %m");
618 /** sending macro; not really required. Uses variables in the local
619 * scope of mainloop(). Get rid of it. */
620 #define SEND writeit( net, &reply, sizeof( reply ));
621 /** error macro; not sure whether we really need this. Uses variables
622 * in the local scope of mainloop(). Get rid of this beast. */
623 #define ERROR { reply.error = htonl(-1); SEND; reply.error = 0; lastpoint = -1; }
625 * Serve a file to a single client.
627 * @todo This beast needs to be split up in many tiny little manageable
628 * pieces. Preferably with a chainsaw.
630 * @param net A network socket, connected to an nbd client
633 int mainloop(int net)
635 struct nbd_request request;
636 struct nbd_reply reply;
641 DEBUG("Entering request loop!\n");
642 reply.magic = htonl(NBD_REPLY_MAGIC);
653 readit(net, &request, sizeof(request));
654 request.from = ntohll(request.from);
655 request.type = ntohl(request.type);
657 if (request.type==NBD_CMD_DISC) { /* Disconnect request */
658 if (difmap) free(difmap) ;
660 close(difffile) ; unlink(difffilename) ; }
661 err("Disconnect request received.") ;
664 len = ntohl(request.len);
666 if (request.magic != htonl(NBD_REQUEST_MAGIC))
667 err("Not enough magic.");
669 err("Request too big!");
671 printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
672 "READ", (unsigned long long)request.from,
673 (unsigned long long)request.from / 512, len);
675 memcpy(reply.handle, request.handle, sizeof(reply.handle));
676 if ((request.from + len) > (OFFT_MAX)) {
677 DEBUG("[Number too large!]");
682 if (((ssize_t)((off_t)request.from + len) > exportsize) ||
683 ((flags & F_READONLY) && request.type)) {
689 if (request.type==1) { /* WRITE */
690 DEBUG("wr: net->buf, ");
691 readit(net, buf, len);
693 if ((autoreadonly == 1) || expwrite(request.from, buf, len)) {
694 DEBUG("Write failed: %m" );
706 if (expread(request.from, buf + sizeof(struct nbd_reply), len)) {
708 DEBUG("Read failed: %m");
715 memcpy(buf, &reply, sizeof(struct nbd_reply));
716 writeit(net, buf, len + sizeof(struct nbd_reply));
722 * Split a single exportfile into multiple ones, if that was asked.
723 * @return 0 on success, -1 on failure
725 int splitexport(void) {
728 for (i=0; i<exportsize; i+=hunksize) {
729 char exportname3[1024];
731 sprintf(exportname3, exportname2, i/hunksize);
732 printf( "Opening %s\n", exportname3 );
733 if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) {
734 /* Read WRITE ACCESS was requested by media is only read only */
737 if ((export[i/hunksize] = open(exportname3, O_RDONLY)) == -1)
738 err("Could not open exported file: %m");
742 if (flags & F_COPYONWRITE) {
743 sprintf(difffilename,"%s-%s-%d.diff",exportname2,clientname,
745 msg3(LOG_INFO,"About to create map and diff file %s",difffilename) ;
746 difffile=open(difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
747 if (difffile<0) err("Could not create diff file (%m)") ;
748 if ((difmap=calloc(exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
749 err("Could not allocate memory") ;
750 for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
757 * Serve a connection.
759 * @todo allow for multithreading, perhaps use libevent.
761 * @param net A network socket connected to an nbd client
763 void serveconnection(int net) {
765 if (exportsize == OFFT_MAX) {
766 exportsize = size_autodetect(export[0]);
768 if (exportsize > OFFT_MAX) {
769 err("Size of exported file is too big\n");
772 msg3(LOG_INFO, "size of exported file/device is %Lu",
773 (unsigned long long)exportsize);
781 * Find the name of the file we have to serve. This will use sprintf()
782 * to put the IP address of the client inside a filename containing
783 * "%s". That name is then written to exportname2
785 * @param net A socket connected to an nbd client
786 * @param clientname a buffer which must be at least 255+1 bytes long;
787 * the IP address (in human-readable format) will be copied in there.
789 void set_peername(int net,char *clientname)
791 struct sockaddr_in addrin;
792 int addrinlen = sizeof( addrin );
795 if (getpeername( net, (struct sockaddr *) &addrin, &addrinlen ) < 0)
796 err("getsockname failed: %m");
797 peername = inet_ntoa(addrin.sin_addr);
798 sprintf(exportname2, exportname, peername);
800 msg4(LOG_INFO, "connect from %s, assigned file is %s",
801 peername, exportname2);
802 strncpy(clientname,peername,255) ;
806 * Connect the socket, and start to serve. This function will fork()
807 * if a connection from an authorized client is received, and will
810 * @todo modularize this giant beast. Preferably with a chainsaw. Also,
811 * it has no business starting mainloop(); it should connect, and be
814 * @param port the port where we will listen
816 void connectme(unsigned int port)
818 struct sockaddr_in addrin;
820 int addrinlen = sizeof(addrin);
821 int net, sock, newpid, i;
835 snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", port);
836 pidf=fopen(pidfname, "w");
838 fprintf(pidf,"%d", (int)getpid());
842 fprintf(stderr, "Not fatal; continuing");
846 #endif /* NODAEMON */
848 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
851 /* lose the pesky "Address already in use" error message */
852 if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
853 err("setsockopt SO_REUSEADDR");
855 if (setsockopt(sock,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
856 err("setsockopt SO_KEEPALIVE");
859 DEBUG("Waiting for connections... bind, ");
860 addrin.sin_family = AF_INET;
861 addrin.sin_port = htons(port);
862 addrin.sin_addr.s_addr = 0;
863 if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
866 if (listen(sock, 1) < 0)
869 sa.sa_handler = sigchld_handler;
870 sigemptyset(&sa.sa_mask);
871 sa.sa_flags = SA_RESTART;
872 if(sigaction(SIGCHLD, &sa, NULL) == -1)
873 err("sigaction: %m");
874 sa.sa_handler = sigterm_handler;
875 sigemptyset(&sa.sa_mask);
876 sa.sa_flags = SA_RESTART;
877 if(sigaction(SIGTERM, &sa, NULL) == -1)
878 err("sigaction: %m");
879 children=malloc(sizeof(pid_t)*child_arraysize);
880 memset(children, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
881 for(;;) { /* infinite loop */
882 if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
885 set_peername(net,clientname);
886 if (!authorized_client(clientname)) {
887 msg2(LOG_INFO,"Unauthorized client") ;
891 msg2(LOG_INFO,"Authorized client") ;
892 for(i=0;children[i]&&i<child_arraysize;i++);
893 if(i>=child_arraysize) {
896 ptr=realloc(children, sizeof(pid_t)*child_arraysize);
899 memset(children+child_arraysize, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
901 child_arraysize+=DEFAULT_CHILD_ARRAY;
903 msg2(LOG_INFO,"Not enough memory to store child PID");
909 if ((children[i]=fork())<0) {
910 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
914 if (children[i]>0) { /* parent */
915 close(net) ; continue ; }
921 msg2(LOG_INFO,"Starting to serve") ;
922 serveconnection(net) ;
927 * Main entry point...
929 int main(int argc, char *argv[])
931 if (sizeof( struct nbd_request )!=28) {
932 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
938 if (!port) return 1 ;
939 connectme(port); /* serve infinitely */