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 /** sending macro... not really required */
107 #define SEND writeit( net, &reply, sizeof( reply ));
108 /** error macro... not sure whether we really need this */
109 #define ERROR { reply.error = htonl(-1); SEND; reply.error = 0; lastpoint = -1; }
110 #ifndef PACKAGE_VERSION
111 #define PACKAGE_VERSION ""
114 * The highest value a variable of type off_t can reach.
116 /* This is starting to get ugly. If someone knows a better way to find
117 * the maximum value of a signed type *without* relying on overflow
118 * (doing so breaks on 64bit architectures), that would be nice.
120 #define OFFT_MAX (((((off_t)1)<<((sizeof(off_t)-1)*8))-1)<<7)+127
121 #define LINELEN 256 /**< Size of static buffer used to read the
122 authorization file (yuck) */
123 #define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */
124 #define GIGA (1*1024*1024*1024) /**< 1 Gigabyte. Used as hunksize when doing
125 the multiple file thingy */
126 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
127 #define F_READONLY 1 /**< flag to tell us a file is readonly */
128 #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
129 #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using copyonwrite */
130 char difffilename[256]; /**< filename of the copy-on-write file. Doesn't belong here! */
131 unsigned int timeout = 0; /**< disconnect timeout */
132 int autoreadonly = 0; /**< 1 = switch to readonly if opening readwrite isn't
134 char *auth_file="nbd_server.allow"; /**< authorization file */
135 char exportname2[1024]; /**< File I'm exporting, with virtualhost resolved */
136 off_t lastpoint = (off_t)-1; /**< keep track of where we are in the file, to
137 avoid an lseek if possible */
138 char pagebuf[DIFFPAGESIZE]; /**< when doing copyonwrite, this is
139 used as a temporary buffer to store
140 the exported block in. @todo this is
141 a great example of namespace
142 pollution. Throw it out. */
143 unsigned int port; /**< Port I'm listening at */
144 char *exportname; /**< File I'm exporting */
145 off_t exportsize = OFFT_MAX; /**< length of file I'm exporting */
146 off_t hunksize = OFFT_MAX; /**< size of each exported file in case of -m */
147 int flags = 0; /**< flags associated with this exported file */
148 int export[1024];/**< array of filedescriptors of exported files; only first is
149 used unless -m option is activated */
150 int difffile=-1; /**< filedescriptor for copyonwrite file */
151 u32 difffilelen=0 ; /**< number of pages in difffile */
152 u32 *difmap=NULL ; /**< Determine whether a block is in the original file
153 (difmap[block]==-1) or in the copyonwrite file (in which
154 case it contains the offset where it is to be found in the
155 copyonwrite file). @todo the kernel knows about sparse
156 files, we should use those instead. Should also be off_t
157 instead of u32; copyonwrite is probably broken wrt LFS */
158 char clientname[256] ;
159 int child_arraysize=DEFAULT_CHILD_ARRAY; /**< number of available slots for
161 pid_t *children; /**< child array */
162 char pidfname[256]; /**< name of our PID file */
165 * Variables associated with a copyonwrite server. Not yet used.
167 typedef struct __cow_opts {
168 char* difffilename; /**< filename of the copy-on-write file */
169 int difffile; /**< filedescriptor of copyonwrite file. @todo
170 shouldn't this be an array too? (cfr
171 nbd_server_opts::export) Or make -m and -c
172 mutually exclusive */
173 u32 difffilelen; /**< number of pages in difffile */
174 u32 *difmap; /**< see comment on the global difmap for this one */
178 * Variables associated with a server. Not yet used.
180 typedef struct __nbd_server_opts {
181 char* exportname; /**< filename of the file we're exporting */
182 unsigned int port; /**< port we're exporting this file at */
183 char* authname; /**< filename of the authorization file */
184 off_t exportsize; /**< size of the file we're exporting */
185 off_t hunksize; /**< size of a hunk of an exported file */
186 int flags; /**< flags associated with this exported file */
187 char* clientname; /**< peer */
188 unsigned int timeout;/**< how long a connection may be idle
190 int export[1024]; /**< array of filedescriptors of exported files;
191 only the first is actually used unless we're
192 doing the multiple file option */
193 cow_opts* cow; /**< only used if (flags | F_COPYONWRITE) */
197 * Check whether a client is allowed to connect. Works with an
198 * authorization file which contains one line per machine, no
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.
269 * @param argc the argc argument to main()
270 * @param argv the argv argument to main()
272 void cmdline(int argc, char *argv[])
277 printf("This is nbd-server version " VERSION "\n");
278 printf("Usage: port file_to_export [size][kKmM] [-r] [-m] [-c] [-a timeout_sec]\n"
280 " -m multiple file\n"
281 " -c copy on write\n"
282 " -l file with list of hosts that are allowed to connect.\n"
283 " -a maximum idle seconds, terminates when idle time exceeded\n"
284 " if port is set to 0, stdin is used (for running from inetd)\n"
285 " if file_to_export contains '%%s', it is substituted with IP\n"
286 " address of machine trying to connect\n" );
289 port = atoi(argv[1]);
290 for (i = 3; i < argc; i++) {
291 if (*argv[i] == '-') {
292 switch (argv[i][1]) {
297 flags |= F_MULTIFILE;
300 case 'c': flags |=F_COPYONWRITE;
307 fprintf(stderr, "host list file requires an argument");
312 timeout = atoi(argv[i+1]);
315 fprintf(stderr, "timeout requires argument\n");
321 size_t last = strlen(argv[i])-1;
322 char suffix = argv[i][last];
323 if (suffix == 'k' || suffix == 'K' ||
324 suffix == 'm' || suffix == 'M')
325 argv[i][last] = '\0';
326 es = (off_t)atol(argv[i]);
338 exportname = argv[2];
342 * Signal handler for SIGCHLD
343 * @param s the signal we're handling (must be SIGCHLD, or something
346 void sigchld_handler(int s)
352 while((pid=wait(status)) > 0) {
353 if(WIFEXITED(status)) {
354 msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status));
356 for(i=0;children[i]!=pid&&i<child_arraysize;i++);
357 if(i>=child_arraysize) {
358 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld",(long) pid);
360 children[i]=(pid_t)0;
361 DEBUG2("Removing %d from the list of children", pid);
367 * Handle SIGTERM and dispatch it to our children
368 * @param s the signal we're handling (must be SIGTERM, or something
369 * is severely wrong).
371 void sigterm_handler(int s) {
375 for(i=0;i<child_arraysize;i++) {
377 kill(children[i], s);
390 * Detect the size of a file.
392 * @param export An open filedescriptor
393 * @return the size of the file, or OFFT_MAX if detection was
396 off_t size_autodetect(int export)
400 struct stat stat_buf;
403 DEBUG("looking for export size with lseek SEEK_END\n");
404 es = lseek(export, (off_t)0, SEEK_END);
405 if (es > ((off_t)0)) {
408 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
411 DEBUG("looking for export size with fstat\n");
412 stat_buf.st_size = 0;
413 error = fstat(export, &stat_buf);
414 if (!error && stat_buf.st_size > 0) {
415 return (off_t)stat_buf.st_size;
417 err("fstat failed: %m");
421 DEBUG("looking for export size with ioctl BLKGETSIZE\n");
422 if (!ioctl(export, BLKGETSIZE, &es32) && es32) {
423 es = (off_t)es32 * (off_t)512;
427 err("Could not find size of exported block device: %m");
432 * Seek to a position in a file, unless we're already there.
433 * @param handle a filedescriptor
434 * @param a position to seek to
436 void maybeseek(int handle, off_t a) {
437 if (a < 0 || a > exportsize) {
438 err("Can not happen\n");
440 if (lastpoint != a) {
441 if (lseek(handle, a, SEEK_SET) < 0) {
442 err("Can not seek locally!\n");
451 * Write an amount of bytes at a given offset to the right file. This
452 * abstracts the write-side of the multiple file option.
454 * @param a The offset where the write should start
455 * @param buf The buffer to write from
456 * @param len The length of buf
457 * @return The number of bytes actually written, or -1 in case of an error
459 int rawexpwrite(off_t a, char *buf, size_t len)
463 maybeseek(export[a/hunksize], a%hunksize);
464 res = write(export[a/hunksize], buf, len);
465 return (res < 0 || (size_t)res != len);
469 * seek to a position in a file, no matter what. Used when using maybeseek is a
470 * bad idea (for instance, because we're reading the copyonwrite file instead
471 * of the exported file)
472 * @param handle a filedescriptor
473 * @param a position to seek to
475 void myseek(int handle,off_t a) {
476 if (lseek(handle, a, SEEK_SET) < 0) {
477 err("Can not seek locally!\n");
482 * Read an amount of bytes at a given offset from the right file. This
483 * abstracts the read-side of the multiple files option.
485 * @param a The offset where the read should start
486 * @param buf A buffer to read into
487 * @param len The size of buf
488 * @return The number of bytes actually read, or -1 in case of an
491 int rawexpread(off_t a, char *buf, size_t len)
495 maybeseek(export[a/hunksize], a%hunksize);
496 res = read(export[a/hunksize], buf, len);
497 return (res < 0 || (size_t)res != len);
501 * Read an amount of bytes at a given offset from the right file. This
502 * abstracts the read-side of the copyonwrite stuff, and calls
503 * rawexpread() with the right parameters to do the actual work.
504 * @param a The offset where the read should start
505 * @param buf A buffer to read into
506 * @param len The size of buf
507 * @return The number of bytes actually read, or -1 in case of an error
509 int expread(off_t a, char *buf, size_t len)
512 off_t mapcnt, mapl, maph, pagestart;
514 if (!(flags & F_COPYONWRITE))
515 return rawexpread(a, buf, len);
516 DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
518 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
520 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
521 pagestart=mapcnt*DIFFPAGESIZE;
523 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
524 len : (size_t)DIFFPAGESIZE-offset;
525 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
526 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
527 (unsigned long)difmap[mapcnt]);
528 myseek(difffile, difmap[mapcnt]*DIFFPAGESIZE+offset);
529 if (read(difffile, buf, rdlen) != rdlen) return -1;
530 } else { /* the block is not there */
531 DEBUG2("Page %Lu is not here, we read the original one\n",
532 (unsigned long long)mapcnt);
533 return rawexpread(a, buf, rdlen);
535 len-=rdlen; a+=rdlen; buf+=rdlen;
541 * Write an amount of bytes at a given offset to the right file. This
542 * abstracts the write-side of the copyonwrite option, and calls
543 * rawexpwrite() with the right parameters to do the actual work.
545 * @param a The offset where the write should start
546 * @param buf The buffer to write from
547 * @param len The length of buf
548 * @return The number of bytes actually written, or -1 in case of an error
550 int expwrite(off_t a, char *buf, size_t len)
552 off_t mapcnt,mapl,maph ;
557 if (!(flags & F_COPYONWRITE))
558 return(rawexpwrite(a,buf,len));
559 DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
561 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
563 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
564 pagestart=mapcnt*DIFFPAGESIZE ;
566 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
567 len : (size_t)DIFFPAGESIZE-offset;
569 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
570 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
571 (unsigned long)difmap[mapcnt]) ;
572 myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
573 if (write(difffile, buf, wrlen) != wrlen) return -1 ;
574 } else { /* the block is not there */
575 myseek(difffile,difffilelen*DIFFPAGESIZE) ;
576 difmap[mapcnt]=difffilelen++ ;
577 DEBUG3("Page %Lu is not here, we put it at %lu\n",
578 (unsigned long long)mapcnt,
579 (unsigned long)difmap[mapcnt]);
581 if (rdlen+pagestart%hunksize>hunksize)
582 rdlen=hunksize-(pagestart%hunksize) ;
583 if (rawexpread(pagestart,pagebuf,rdlen)) return -1 ;
584 memcpy(pagebuf+offset,buf,wrlen) ;
585 if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
587 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
593 * Do the initial negotiation.
595 * @param net A socket to do the negotiation over
597 void negotiate(int net) {
601 memset(zeros, 0, 290);
602 if (write(net, INIT_PASSWD, 8) < 0)
603 err("Negotiation failed: %m");
604 cliserv_magic = htonll(cliserv_magic);
605 if (write(net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
606 err("Negotiation failed: %m");
607 size_host = htonll((u64)exportsize);
608 if (write(net, &size_host, 8) < 0)
609 err("Negotiation failed: %m");
610 if (write(net, zeros, 128) < 0)
611 err("Negotiation failed: %m");
615 * Serve a file to a single client.
617 * @todo This beast needs to be split up in many tiny little manageable
618 * pieces. Preferably with a chainsaw.
620 * @param net A network socket, connected to an nbd client
623 int mainloop(int net)
625 struct nbd_request request;
626 struct nbd_reply reply;
631 DEBUG("Entering request loop!\n");
632 reply.magic = htonl(NBD_REPLY_MAGIC);
643 readit(net, &request, sizeof(request));
644 request.from = ntohll(request.from);
645 request.type = ntohl(request.type);
647 if (request.type==NBD_CMD_DISC) { /* Disconnect request */
648 if (difmap) free(difmap) ;
650 close(difffile) ; unlink(difffilename) ; }
651 err("Disconnect request received.") ;
654 len = ntohl(request.len);
656 if (request.magic != htonl(NBD_REQUEST_MAGIC))
657 err("Not enough magic.");
659 err("Request too big!");
661 printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
662 "READ", (unsigned long long)request.from,
663 (unsigned long long)request.from / 512, len);
665 memcpy(reply.handle, request.handle, sizeof(reply.handle));
666 if ((request.from + len) > (OFFT_MAX)) {
667 DEBUG("[Number too large!]");
672 if (((ssize_t)((off_t)request.from + len) > exportsize) ||
673 ((flags & F_READONLY) && request.type)) {
679 if (request.type==1) { /* WRITE */
680 DEBUG("wr: net->buf, ");
681 readit(net, buf, len);
683 if ((autoreadonly == 1) || expwrite(request.from, buf, len)) {
684 DEBUG("Write failed: %m" );
696 if (expread(request.from, buf + sizeof(struct nbd_reply), len)) {
698 DEBUG("Read failed: %m");
705 memcpy(buf, &reply, sizeof(struct nbd_reply));
706 writeit(net, buf, len + sizeof(struct nbd_reply));
712 * Split a single exportfile into multiple ones, if that was asked.
713 * @return 0 on success, -1 on failure
715 int splitexport(void) {
718 for (i=0; i<exportsize; i+=hunksize) {
719 char exportname3[1024];
721 sprintf(exportname3, exportname2, i/hunksize);
722 printf( "Opening %s\n", exportname3 );
723 if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) {
724 /* Read WRITE ACCESS was requested by media is only read only */
727 if ((export[i/hunksize] = open(exportname3, O_RDONLY)) == -1)
728 err("Could not open exported file: %m");
732 if (flags & F_COPYONWRITE) {
733 sprintf(difffilename,"%s-%s-%d.diff",exportname2,clientname,
735 msg3(LOG_INFO,"About to create map and diff file %s",difffilename) ;
736 difffile=open(difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
737 if (difffile<0) err("Could not create diff file (%m)") ;
738 if ((difmap=calloc(exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
739 err("Could not allocate memory") ;
740 for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
747 * Serve a connection.
749 * @todo allow for multithreading, perhaps use libevent.
751 * @param net A network socket connected to an nbd client
753 void serveconnection(int net) {
755 if (exportsize == OFFT_MAX) {
756 exportsize = size_autodetect(export[0]);
758 if (exportsize > OFFT_MAX) {
759 err("Size of exported file is too big\n");
762 msg3(LOG_INFO, "size of exported file/device is %Lu",
763 (unsigned long long)exportsize);
771 * Find the name of the file we have to serve. This will use sprintf()
772 * to put the IP address of the client inside a filename containing
773 * "%s". That name is then written to exportname2
775 * @param net A socket connected to an nbd client
776 * @param clientname a buffer which must be at least 255+1 bytes long;
777 * the IP address (in human-readable format) will be copied in there.
779 void set_peername(int net,char *clientname)
781 struct sockaddr_in addrin;
782 int addrinlen = sizeof( addrin );
785 if (getpeername( net, (struct sockaddr *) &addrin, &addrinlen ) < 0)
786 err("getsockname failed: %m");
787 peername = inet_ntoa(addrin.sin_addr);
788 sprintf(exportname2, exportname, peername);
790 msg4(LOG_INFO, "connect from %s, assigned file is %s",
791 peername, exportname2);
792 strncpy(clientname,peername,255) ;
796 * Connect the socket, and start to serve. This function will fork()
797 * if a connection from an authorized client is received, and will
800 * @todo modularize this giant beast. Preferably with a chainsaw. Also,
801 * it has no business starting mainloop(); it should connect, and be
804 * @param port the port where we will listen
806 void connectme(unsigned int port)
808 struct sockaddr_in addrin;
810 int addrinlen = sizeof(addrin);
811 int net, sock, newpid, i;
825 snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", port);
826 pidf=fopen(pidfname, "w");
828 fprintf(pidf,"%d", (int)getpid());
832 fprintf(stderr, "Not fatal; continuing");
836 #endif /* NODAEMON */
838 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
841 /* lose the pesky "Address already in use" error message */
842 if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
843 err("setsockopt SO_REUSEADDR");
845 if (setsockopt(sock,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
846 err("setsockopt SO_KEEPALIVE");
849 DEBUG("Waiting for connections... bind, ");
850 addrin.sin_family = AF_INET;
851 addrin.sin_port = htons(port);
852 addrin.sin_addr.s_addr = 0;
853 if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
856 if (listen(sock, 1) < 0)
859 sa.sa_handler = sigchld_handler;
860 sigemptyset(&sa.sa_mask);
861 sa.sa_flags = SA_RESTART;
862 if(sigaction(SIGCHLD, &sa, NULL) == -1)
863 err("sigaction: %m");
864 sa.sa_handler = sigterm_handler;
865 sigemptyset(&sa.sa_mask);
866 sa.sa_flags = SA_RESTART;
867 if(sigaction(SIGTERM, &sa, NULL) == -1)
868 err("sigaction: %m");
869 children=malloc(sizeof(pid_t)*child_arraysize);
870 memset(children, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
871 for(;;) { /* infinite loop */
872 if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
875 set_peername(net,clientname);
876 if (!authorized_client(clientname)) {
877 msg2(LOG_INFO,"Unauthorized client") ;
881 msg2(LOG_INFO,"Authorized client") ;
882 for(i=0;children[i]&&i<child_arraysize;i++);
883 if(i>=child_arraysize) {
886 ptr=realloc(children, sizeof(pid_t)*child_arraysize);
889 memset(children+child_arraysize, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
891 child_arraysize+=DEFAULT_CHILD_ARRAY;
893 msg2(LOG_INFO,"Not enough memory to store child PID");
899 if ((children[i]=fork())<0) {
900 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
904 if (children[i]>0) { /* parent */
905 close(net) ; continue ; }
911 msg2(LOG_INFO,"Starting to serve") ;
912 serveconnection(net) ;
917 * Main entry point...
919 int main(int argc, char *argv[])
921 if (sizeof( struct nbd_request )!=28) {
922 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
928 if (!port) return 1 ;
929 connectme(port); /* serve infinitely */