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 #include <sys/types.h>
55 #include <sys/socket.h>
57 #include <sys/wait.h> /* wait */
58 #include <sys/ioctl.h>
59 #include <sys/param.h>
60 #include <sys/mount.h> /* For BLKGETSIZE */
61 #include <signal.h> /* sigaction */
62 #include <netinet/tcp.h>
63 #include <netinet/in.h> /* sockaddr_in, htons, in_addr */
64 #include <netdb.h> /* hostent, gethostby*, getservby* */
71 #include <arpa/inet.h>
75 /* used in cliserv.h, so must come first */
76 #define MY_NAME "nbd_server"
79 /** how much space for child PIDs we have by default. Dynamically
80 allocated, and will be realloc()ed if out of space, so this should
81 probably be fair for most situations. */
82 #define DEFAULT_CHILD_ARRAY 256
84 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */
86 #define msg2(a,b) syslog(a,b)
87 #define msg3(a,b,c) syslog(a,b,c)
88 #define msg4(a,b,c,d) syslog(a,b,c,d)
90 #define msg2(a,b) do { fprintf(stderr,b) ; fputs("\n",stderr) ; } while(0)
91 #define msg3(a,b,c) do { fprintf(stderr,b,c); fputs("\n",stderr) ; } while(0)
92 #define msg4(a,b,c,d) do { fprintf(stderr,b,c,d); fputs("\n",stderr) ; } while(0)
95 /* Debugging macros */
98 #define DEBUG( a ) printf( a )
99 #define DEBUG2( a,b ) printf( a,b )
100 #define DEBUG3( a,b,c ) printf( a,b,c )
103 #define DEBUG2( a,b )
104 #define DEBUG3( a,b,c )
106 #ifndef PACKAGE_VERSION
107 #define PACKAGE_VERSION ""
110 * The highest value a variable of type off_t can reach.
112 /* This is starting to get ugly. If someone knows a better way to find
113 * the maximum value of a signed type *without* relying on overflow
114 * (doing so breaks on 64bit architectures), that would be nice.
116 #define OFFT_MAX (((((off_t)1)<<((sizeof(off_t)-1)*8))-1)<<7)+127
117 #define LINELEN 256 /**< Size of static buffer used to read the
118 authorization file (yuck) */
119 #define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */
120 #define GIGA (1*1024*1024*1024) /**< 1 Gigabyte. Used as hunksize when doing
121 the multiple file thingy */
122 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
123 #define F_READONLY 1 /**< flag to tell us a file is readonly */
124 #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
125 #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using copyonwrite */
126 char difffilename[256]; /**< filename of the copy-on-write file. Doesn't belong here! */
127 unsigned int timeout = 0; /**< disconnect timeout */
128 int autoreadonly = 0; /**< 1 = switch to readonly if opening readwrite isn't
130 char *auth_file="nbd_server.allow"; /**< authorization file */
131 char exportname2[1024]; /**< File I'm exporting, with virtualhost resolved */
132 off_t lastpoint = (off_t)-1; /**< keep track of where we are in the file, to
133 avoid an lseek if possible */
134 char pagebuf[DIFFPAGESIZE]; /**< when doing copyonwrite, this is
135 used as a temporary buffer to store
136 the exported block in. @todo this is
137 a great example of namespace
138 pollution. Throw it out. */
139 unsigned int port; /**< Port I'm listening at */
140 char *exportname; /**< File I'm exporting */
141 off_t exportsize = OFFT_MAX; /**< length of file I'm exporting */
142 off_t hunksize = OFFT_MAX; /**< size of each exported file in case of -m */
143 int flags = 0; /**< flags associated with this exported file */
144 int export[1024];/**< array of filedescriptors of exported files; only first is
145 used unless -m option is activated */
146 int difffile=-1; /**< filedescriptor for copyonwrite file */
147 u32 difffilelen=0 ; /**< number of pages in difffile */
148 u32 *difmap=NULL ; /**< Determine whether a block is in the original file
149 (difmap[block]==-1) or in the copyonwrite file (in which
150 case it contains the offset where it is to be found in the
151 copyonwrite file). @todo the kernel knows about sparse
152 files, we should use those instead. Should also be off_t
153 instead of u32; copyonwrite is probably broken wrt LFS */
154 char clientname[256] ;
155 int child_arraysize=DEFAULT_CHILD_ARRAY; /**< number of available slots for
157 pid_t *children; /**< child array */
158 char pidfname[256]; /**< name of our PID file */
161 * Variables associated with a copyonwrite server. Not yet used.
164 char* difffilename; /**< filename of the copy-on-write file */
165 int difffile; /**< filedescriptor of copyonwrite file. @todo
166 shouldn't this be an array too? (cfr
167 nbd_server_opts::export) Or make -m and -c
168 mutually exclusive */
169 u32 difffilelen; /**< number of pages in difffile */
170 u32 *difmap; /**< see comment on the global difmap for this one */
174 * Variables associated with a server. Not yet used. @todo modify the code to
175 * use an instance of this struct instead of the heap of global variables.
178 char* exportname; /**< filename of the file we're exporting */
179 unsigned int port; /**< port we're exporting this file at */
180 char* authname; /**< filename of the authorization file */
181 off_t exportsize; /**< size of the file we're exporting */
182 off_t hunksize; /**< size of a hunk of an exported file */
183 int flags; /**< flags associated with this exported file */
184 char* clientname; /**< peer */
185 unsigned int timeout;/**< how long a connection may be idle
187 int export[1024]; /**< array of filedescriptors of exported files;
188 only the first is actually used unless we're
189 doing the multiple file option */
190 cow_opts* cow; /**< only used if (flags | F_COPYONWRITE) (NULL
195 * Check whether a client is allowed to connect. Works with an authorization
196 * file which contains one line per machine, no wildcards.
198 * @param name IP address of client trying to connect (in human-readable form)
199 * @return 0 - authorization refused, 1 - OK
201 int authorized_client(char *name)
207 if ((f=fopen(auth_file,"r"))==NULL) {
208 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
209 auth_file,strerror(errno)) ;
213 while (fgets(line,LINELEN,f)!=NULL) {
214 if (strncmp(line,name,strlen(name))==0) {
224 * Read data from a file descriptor into a buffer
226 * @param f a file descriptor
227 * @param buf a buffer
228 * @param len the number of bytes to be read
230 inline void readit(int f, void *buf, size_t len)
235 if ((res = read(f, buf, len)) <= 0)
236 err("Read failed: %m");
243 * Write data from a buffer into a filedescriptor
245 * @param f a file descriptor
246 * @param buf a buffer containing data
247 * @param len the number of bytes to be written
249 inline void writeit(int f, void *buf, size_t len)
254 if ((res = write(f, buf, len)) <= 0)
255 err("Send failed: %m");
262 * Parse the command line.
264 * @todo getopt() is a great thing, and easy to use. Also, we want to
265 * create a configuration file which nbd-server will read. Maybe do (as in,
268 * @param argc the argc argument to main()
269 * @param argv the argv argument to main()
271 void cmdline(int argc, char *argv[])
276 printf("This is nbd-server version " VERSION "\n");
277 printf("Usage: port file_to_export [size][kKmM] [-r] [-m] [-c] [-a timeout_sec]\n"
279 " -m multiple file\n"
280 " -c copy on write\n"
281 " -l file with list of hosts that are allowed to connect.\n"
282 " -a maximum idle seconds, terminates when idle time exceeded\n"
283 " if port is set to 0, stdin is used (for running from inetd)\n"
284 " if file_to_export contains '%%s', it is substituted with IP\n"
285 " address of machine trying to connect\n" );
288 port = atoi(argv[1]);
289 for (i = 3; i < argc; i++) {
290 if (*argv[i] == '-') {
291 switch (argv[i][1]) {
296 flags |= F_MULTIFILE;
299 case 'c': flags |=F_COPYONWRITE;
306 fprintf(stderr, "host list file requires an argument");
311 timeout = atoi(argv[i+1]);
314 fprintf(stderr, "timeout requires argument\n");
320 size_t last = strlen(argv[i])-1;
321 char suffix = argv[i][last];
322 if (suffix == 'k' || suffix == 'K' ||
323 suffix == 'm' || suffix == 'M')
324 argv[i][last] = '\0';
325 es = (off_t)atol(argv[i]);
337 exportname = argv[2];
341 * Signal handler for SIGCHLD
342 * @param s the signal we're handling (must be SIGCHLD, or something
345 void sigchld_handler(int s)
351 while((pid=wait(status)) > 0) {
352 if(WIFEXITED(status)) {
353 msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status));
355 for(i=0;children[i]!=pid&&i<child_arraysize;i++);
356 if(i>=child_arraysize) {
357 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld",(long) pid);
359 children[i]=(pid_t)0;
360 DEBUG2("Removing %d from the list of children", pid);
366 * Handle SIGTERM and dispatch it to our children
367 * @param s the signal we're handling (must be SIGTERM, or something
368 * is severely wrong).
370 void sigterm_handler(int s) {
374 for(i=0;i<child_arraysize;i++) {
376 kill(children[i], s);
389 * Detect the size of a file.
391 * @param export An open filedescriptor
392 * @return the size of the file, or OFFT_MAX if detection was
395 off_t size_autodetect(int export)
399 struct stat stat_buf;
402 DEBUG("looking for export size with lseek SEEK_END\n");
403 es = lseek(export, (off_t)0, SEEK_END);
404 if (es > ((off_t)0)) {
407 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
410 DEBUG("looking for export size with fstat\n");
411 stat_buf.st_size = 0;
412 error = fstat(export, &stat_buf);
413 if (!error && stat_buf.st_size > 0) {
414 return (off_t)stat_buf.st_size;
416 err("fstat failed: %m");
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;
426 err("Could not find size of exported block device: %m");
431 * Seek to a position in a file, unless we're already there.
432 * @param handle a filedescriptor
433 * @param a position to seek to
435 void maybeseek(int handle, off_t a) {
436 if (a < 0 || a > exportsize) {
437 err("Can not happen\n");
439 if (lastpoint != a) {
440 if (lseek(handle, a, SEEK_SET) < 0) {
441 err("Can not seek locally!\n");
450 * Write an amount of bytes at a given offset to the right file. This
451 * abstracts the write-side of the multiple file option.
453 * @param a The offset where the write should start
454 * @param buf The buffer to write from
455 * @param len The length of buf
456 * @return The number of bytes actually written, or -1 in case of an error
458 int rawexpwrite(off_t a, char *buf, size_t len)
462 maybeseek(export[a/hunksize], a%hunksize);
463 res = write(export[a/hunksize], buf, len);
464 return (res < 0 || (size_t)res != len);
468 * seek to a position in a file, no matter what. Used when using maybeseek is a
469 * bad idea (for instance, because we're reading the copyonwrite file instead
470 * of the exported file).
471 * @param handle a filedescriptor
472 * @param a position to seek to
473 * @todo get rid of this; lastpoint is a global variable right now, but it
474 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
477 void myseek(int handle,off_t a) {
478 if (lseek(handle, a, SEEK_SET) < 0) {
479 err("Can not seek locally!\n");
484 * Read an amount of bytes at a given offset from the right file. This
485 * abstracts the read-side of the multiple files option.
487 * @param a The offset where the read should start
488 * @param buf A buffer to read into
489 * @param len The size of buf
490 * @return The number of bytes actually read, or -1 in case of an
493 int rawexpread(off_t a, char *buf, size_t len)
497 maybeseek(export[a/hunksize], a%hunksize);
498 res = read(export[a/hunksize], buf, len);
499 return (res < 0 || (size_t)res != len);
503 * Read an amount of bytes at a given offset from the right file. This
504 * abstracts the read-side of the copyonwrite stuff, and calls
505 * rawexpread() with the right parameters to do the actual work.
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 error
511 int expread(off_t a, char *buf, size_t len)
514 off_t mapcnt, mapl, maph, pagestart;
516 if (!(flags & F_COPYONWRITE))
517 return rawexpread(a, buf, len);
518 DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
520 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
522 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
523 pagestart=mapcnt*DIFFPAGESIZE;
525 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
526 len : (size_t)DIFFPAGESIZE-offset;
527 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
528 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
529 (unsigned long)difmap[mapcnt]);
530 myseek(difffile, difmap[mapcnt]*DIFFPAGESIZE+offset);
531 if (read(difffile, buf, rdlen) != rdlen) return -1;
532 } else { /* the block is not there */
533 DEBUG2("Page %Lu is not here, we read the original one\n",
534 (unsigned long long)mapcnt);
535 return rawexpread(a, buf, rdlen);
537 len-=rdlen; a+=rdlen; buf+=rdlen;
543 * Write an amount of bytes at a given offset to the right file. This
544 * abstracts the write-side of the copyonwrite option, and calls
545 * rawexpwrite() with the right parameters to do the actual work.
547 * @param a The offset where the write should start
548 * @param buf The buffer to write from
549 * @param len The length of buf
550 * @return The number of bytes actually written, or -1 in case of an error
552 int expwrite(off_t a, char *buf, size_t len)
554 off_t mapcnt,mapl,maph ;
559 if (!(flags & F_COPYONWRITE))
560 return(rawexpwrite(a,buf,len));
561 DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
563 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
565 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
566 pagestart=mapcnt*DIFFPAGESIZE ;
568 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
569 len : (size_t)DIFFPAGESIZE-offset;
571 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
572 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
573 (unsigned long)difmap[mapcnt]) ;
574 myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
575 if (write(difffile, buf, wrlen) != wrlen) return -1 ;
576 } else { /* the block is not there */
577 myseek(difffile,difffilelen*DIFFPAGESIZE) ;
578 difmap[mapcnt]=difffilelen++ ;
579 DEBUG3("Page %Lu is not here, we put it at %lu\n",
580 (unsigned long long)mapcnt,
581 (unsigned long)difmap[mapcnt]);
583 if (rdlen+pagestart%hunksize>hunksize)
584 rdlen=hunksize-(pagestart%hunksize) ;
585 if (rawexpread(pagestart,pagebuf,rdlen)) return -1 ;
586 memcpy(pagebuf+offset,buf,wrlen) ;
587 if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
589 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
595 * Do the initial negotiation.
597 * @param net A socket to do the negotiation over
599 void negotiate(int net) {
603 memset(zeros, 0, 290);
604 if (write(net, INIT_PASSWD, 8) < 0)
605 err("Negotiation failed: %m");
606 cliserv_magic = htonll(cliserv_magic);
607 if (write(net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
608 err("Negotiation failed: %m");
609 size_host = htonll((u64)exportsize);
610 if (write(net, &size_host, 8) < 0)
611 err("Negotiation failed: %m");
612 if (write(net, zeros, 128) < 0)
613 err("Negotiation failed: %m");
616 /** sending macro; not really required. Uses variables in the local
617 * scope of mainloop(). Get rid of it. */
618 #define SEND writeit( net, &reply, sizeof( reply ));
619 /** error macro; not sure whether we really need this. Uses variables
620 * in the local scope of mainloop(). Get rid of this beast. */
621 #define ERROR { reply.error = htonl(-1); SEND; reply.error = 0; lastpoint = -1; }
623 * Serve a file to a single client.
625 * @todo This beast needs to be split up in many tiny little manageable
626 * pieces. Preferably with a chainsaw.
628 * @param net A network socket, connected to an nbd client
631 int mainloop(int net)
633 struct nbd_request request;
634 struct nbd_reply reply;
639 DEBUG("Entering request loop!\n");
640 reply.magic = htonl(NBD_REPLY_MAGIC);
651 readit(net, &request, sizeof(request));
652 request.from = ntohll(request.from);
653 request.type = ntohl(request.type);
655 if (request.type==NBD_CMD_DISC) { /* Disconnect request */
656 if (difmap) free(difmap) ;
658 close(difffile) ; unlink(difffilename) ; }
659 err("Disconnect request received.") ;
662 len = ntohl(request.len);
664 if (request.magic != htonl(NBD_REQUEST_MAGIC))
665 err("Not enough magic.");
667 err("Request too big!");
669 printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
670 "READ", (unsigned long long)request.from,
671 (unsigned long long)request.from / 512, len);
673 memcpy(reply.handle, request.handle, sizeof(reply.handle));
674 if ((request.from + len) > (OFFT_MAX)) {
675 DEBUG("[Number too large!]");
680 if (((ssize_t)((off_t)request.from + len) > exportsize) ||
681 ((flags & F_READONLY) && request.type)) {
687 if (request.type==1) { /* WRITE */
688 DEBUG("wr: net->buf, ");
689 readit(net, buf, len);
691 if ((autoreadonly == 1) || expwrite(request.from, buf, len)) {
692 DEBUG("Write failed: %m" );
704 if (expread(request.from, buf + sizeof(struct nbd_reply), len)) {
706 DEBUG("Read failed: %m");
713 memcpy(buf, &reply, sizeof(struct nbd_reply));
714 writeit(net, buf, len + sizeof(struct nbd_reply));
720 * Split a single exportfile into multiple ones, if that was asked.
721 * @return 0 on success, -1 on failure
723 int splitexport(void) {
726 for (i=0; i<exportsize; i+=hunksize) {
727 char exportname3[1024];
729 sprintf(exportname3, exportname2, i/hunksize);
730 printf( "Opening %s\n", exportname3 );
731 if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) {
732 /* Read WRITE ACCESS was requested by media is only read only */
735 if ((export[i/hunksize] = open(exportname3, O_RDONLY)) == -1)
736 err("Could not open exported file: %m");
740 if (flags & F_COPYONWRITE) {
741 sprintf(difffilename,"%s-%s-%d.diff",exportname2,clientname,
743 msg3(LOG_INFO,"About to create map and diff file %s",difffilename) ;
744 difffile=open(difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
745 if (difffile<0) err("Could not create diff file (%m)") ;
746 if ((difmap=calloc(exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
747 err("Could not allocate memory") ;
748 for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
755 * Serve a connection.
757 * @todo allow for multithreading, perhaps use libevent.
759 * @param net A network socket connected to an nbd client
761 void serveconnection(int net) {
763 if (exportsize == OFFT_MAX) {
764 exportsize = size_autodetect(export[0]);
766 if (exportsize > OFFT_MAX) {
767 err("Size of exported file is too big\n");
770 msg3(LOG_INFO, "size of exported file/device is %Lu",
771 (unsigned long long)exportsize);
779 * Find the name of the file we have to serve. This will use sprintf()
780 * to put the IP address of the client inside a filename containing
781 * "%s". That name is then written to exportname2
783 * @param net A socket connected to an nbd client
784 * @param clientname a buffer which must be at least 255+1 bytes long;
785 * the IP address (in human-readable format) will be copied in there.
787 void set_peername(int net,char *clientname)
789 struct sockaddr_in addrin;
790 int addrinlen = sizeof( addrin );
793 if (getpeername( net, (struct sockaddr *) &addrin, &addrinlen ) < 0)
794 err("getsockname failed: %m");
795 peername = inet_ntoa(addrin.sin_addr);
796 sprintf(exportname2, exportname, peername);
798 msg4(LOG_INFO, "connect from %s, assigned file is %s",
799 peername, exportname2);
800 strncpy(clientname,peername,255) ;
804 * Connect the socket, and start to serve. This function will fork()
805 * if a connection from an authorized client is received, and will
808 * @todo modularize this giant beast. Preferably with a chainsaw. Also,
809 * it has no business starting mainloop(); it should connect, and be
812 * @param port the port where we will listen
814 void connectme(unsigned int port)
816 struct sockaddr_in addrin;
818 int addrinlen = sizeof(addrin);
819 int net, sock, newpid, i;
833 snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", port);
834 pidf=fopen(pidfname, "w");
836 fprintf(pidf,"%d", (int)getpid());
840 fprintf(stderr, "Not fatal; continuing");
844 #endif /* NODAEMON */
846 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
849 /* lose the pesky "Address already in use" error message */
850 if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
851 err("setsockopt SO_REUSEADDR");
853 if (setsockopt(sock,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
854 err("setsockopt SO_KEEPALIVE");
857 DEBUG("Waiting for connections... bind, ");
858 addrin.sin_family = AF_INET;
859 addrin.sin_port = htons(port);
860 addrin.sin_addr.s_addr = 0;
861 if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
864 if (listen(sock, 1) < 0)
867 sa.sa_handler = sigchld_handler;
868 sigemptyset(&sa.sa_mask);
869 sa.sa_flags = SA_RESTART;
870 if(sigaction(SIGCHLD, &sa, NULL) == -1)
871 err("sigaction: %m");
872 sa.sa_handler = sigterm_handler;
873 sigemptyset(&sa.sa_mask);
874 sa.sa_flags = SA_RESTART;
875 if(sigaction(SIGTERM, &sa, NULL) == -1)
876 err("sigaction: %m");
877 children=malloc(sizeof(pid_t)*child_arraysize);
878 memset(children, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
879 for(;;) { /* infinite loop */
880 if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
883 set_peername(net,clientname);
884 if (!authorized_client(clientname)) {
885 msg2(LOG_INFO,"Unauthorized client") ;
889 msg2(LOG_INFO,"Authorized client") ;
890 for(i=0;children[i]&&i<child_arraysize;i++);
891 if(i>=child_arraysize) {
894 ptr=realloc(children, sizeof(pid_t)*child_arraysize);
897 memset(children+child_arraysize, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
899 child_arraysize+=DEFAULT_CHILD_ARRAY;
901 msg2(LOG_INFO,"Not enough memory to store child PID");
907 if ((children[i]=fork())<0) {
908 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
912 if (children[i]>0) { /* parent */
913 close(net) ; continue ; }
919 msg2(LOG_INFO,"Starting to serve") ;
920 serveconnection(net) ;
925 * Main entry point...
927 int main(int argc, char *argv[])
929 if (sizeof( struct nbd_request )!=28) {
930 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
936 if (!port) return 1 ;
937 connectme(port); /* serve infinitely */