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,b)
95 #define msg3(a,b,c) syslog(a,b,c)
96 #define msg4(a,b,c,d) syslog(a,b,c,d)
98 #define msg2(a,b) do { fprintf(stderr,b) ; fputs("\n",stderr) ; } while(0)
99 #define msg3(a,b,c) do { fprintf(stderr,b,c); fputs("\n",stderr) ; } while(0)
100 #define msg4(a,b,c,d) do { fprintf(stderr,b,c,d); fputs("\n",stderr) ; } 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)
359 while((pid=wait(status)) > 0) {
360 if(WIFEXITED(status)) {
361 msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status));
363 for(i=0;children[i]!=pid&&i<child_arraysize;i++);
364 if(i>=child_arraysize) {
365 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld",(long) pid);
367 children[i]=(pid_t)0;
368 DEBUG2("Removing %d from the list of children", pid);
374 * Handle SIGTERM and dispatch it to our children
375 * @param s the signal we're handling (must be SIGTERM, or something
376 * is severely wrong).
378 void sigterm_handler(int s) {
382 for(i=0;i<child_arraysize;i++) {
384 kill(children[i], s);
397 * Detect the size of a file.
399 * @param export An open filedescriptor
400 * @return the size of the file, or OFFT_MAX if detection was
403 off_t size_autodetect(int export)
407 struct stat stat_buf;
410 #ifdef HAVE_SYS_MOUNT_H
411 #ifdef HAVE_SYS_IOCTL_H
413 DEBUG("looking for export size with ioctl BLKGETSIZE\n");
414 if (!ioctl(export, BLKGETSIZE, &es32) && es32) {
415 es = (off_t)es32 * (off_t)512;
418 #endif /* BLKGETSIZE */
419 #endif /* HAVE_SYS_IOCTL_H */
420 #endif /* HAVE_SYS_MOUNT_H */
422 DEBUG("looking for export size with fstat\n");
423 stat_buf.st_size = 0;
424 error = fstat(export, &stat_buf);
425 if (!error && stat_buf.st_size > 0) {
426 return (off_t)stat_buf.st_size;
428 err("fstat failed: %m");
431 DEBUG("looking for export size with lseek SEEK_END\n");
432 es = lseek(export, (off_t)0, SEEK_END);
433 if (es > ((off_t)0)) {
436 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
439 err("Could not find size of exported block device: %m");
444 * Seek to a position in a file, unless we're already there.
445 * @param handle a filedescriptor
446 * @param a position to seek to
448 void maybeseek(int handle, off_t a) {
449 if (a < 0 || a > exportsize) {
450 err("Can not happen\n");
452 if (lastpoint != a) {
453 if (lseek(handle, a, SEEK_SET) < 0) {
454 err("Can not seek locally!\n");
463 * Write an amount of bytes at a given offset to the right file. This
464 * abstracts the write-side of the multiple file option.
466 * @param a The offset where the write should start
467 * @param buf The buffer to write from
468 * @param len The length of buf
469 * @return The number of bytes actually written, or -1 in case of an error
471 int rawexpwrite(off_t a, char *buf, size_t len)
475 maybeseek(export[a/hunksize], a%hunksize);
476 res = write(export[a/hunksize], buf, len);
477 return (res < 0 || (size_t)res != len);
481 * seek to a position in a file, no matter what. Used when using maybeseek is a
482 * bad idea (for instance, because we're reading the copyonwrite file instead
483 * of the exported file).
484 * @param handle a filedescriptor
485 * @param a position to seek to
486 * @todo get rid of this; lastpoint is a global variable right now, but it
487 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
490 void myseek(int handle,off_t a) {
491 if (lseek(handle, a, SEEK_SET) < 0) {
492 err("Can not seek locally!\n");
497 * Read an amount of bytes at a given offset from the right file. This
498 * abstracts the read-side of the multiple files option.
500 * @param a The offset where the read should start
501 * @param buf A buffer to read into
502 * @param len The size of buf
503 * @return The number of bytes actually read, or -1 in case of an
506 int rawexpread(off_t a, char *buf, size_t len)
510 maybeseek(export[a/hunksize], a%hunksize);
511 res = read(export[a/hunksize], buf, len);
512 return (res < 0 || (size_t)res != len);
516 * Read an amount of bytes at a given offset from the right file. This
517 * abstracts the read-side of the copyonwrite stuff, and calls
518 * rawexpread() with the right parameters to do the actual work.
519 * @param a The offset where the read should start
520 * @param buf A buffer to read into
521 * @param len The size of buf
522 * @return The number of bytes actually read, or -1 in case of an error
524 int expread(off_t a, char *buf, size_t len)
527 off_t mapcnt, mapl, maph, pagestart;
529 if (!(flags & F_COPYONWRITE))
530 return rawexpread(a, buf, len);
531 DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
533 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
535 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
536 pagestart=mapcnt*DIFFPAGESIZE;
538 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
539 len : (size_t)DIFFPAGESIZE-offset;
540 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
541 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
542 (unsigned long)difmap[mapcnt]);
543 myseek(difffile, difmap[mapcnt]*DIFFPAGESIZE+offset);
544 if (read(difffile, buf, rdlen) != rdlen) return -1;
545 } else { /* the block is not there */
546 DEBUG2("Page %Lu is not here, we read the original one\n",
547 (unsigned long long)mapcnt);
548 return rawexpread(a, buf, rdlen);
550 len-=rdlen; a+=rdlen; buf+=rdlen;
556 * Write an amount of bytes at a given offset to the right file. This
557 * abstracts the write-side of the copyonwrite option, and calls
558 * rawexpwrite() with the right parameters to do the actual work.
560 * @param a The offset where the write should start
561 * @param buf The buffer to write from
562 * @param len The length of buf
563 * @return The number of bytes actually written, or -1 in case of an error
565 int expwrite(off_t a, char *buf, size_t len)
567 off_t mapcnt,mapl,maph ;
572 if (!(flags & F_COPYONWRITE))
573 return(rawexpwrite(a,buf,len));
574 DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
576 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
578 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
579 pagestart=mapcnt*DIFFPAGESIZE ;
581 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
582 len : (size_t)DIFFPAGESIZE-offset;
584 if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
585 DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
586 (unsigned long)difmap[mapcnt]) ;
587 myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
588 if (write(difffile, buf, wrlen) != wrlen) return -1 ;
589 } else { /* the block is not there */
590 myseek(difffile,difffilelen*DIFFPAGESIZE) ;
591 difmap[mapcnt]=difffilelen++ ;
592 DEBUG3("Page %Lu is not here, we put it at %lu\n",
593 (unsigned long long)mapcnt,
594 (unsigned long)difmap[mapcnt]);
596 if (rdlen+pagestart%hunksize>hunksize)
597 rdlen=hunksize-(pagestart%hunksize) ;
598 if (rawexpread(pagestart,pagebuf,rdlen)) return -1 ;
599 memcpy(pagebuf+offset,buf,wrlen) ;
600 if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
602 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
608 * Do the initial negotiation.
610 * @param net A socket to do the negotiation over
612 void negotiate(int net) {
616 memset(zeros, 0, 290);
617 if (write(net, INIT_PASSWD, 8) < 0)
618 err("Negotiation failed: %m");
619 cliserv_magic = htonll(cliserv_magic);
620 if (write(net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
621 err("Negotiation failed: %m");
622 size_host = htonll((u64)exportsize);
623 if (write(net, &size_host, 8) < 0)
624 err("Negotiation failed: %m");
625 if (write(net, zeros, 128) < 0)
626 err("Negotiation failed: %m");
629 /** sending macro; not really required. Uses variables in the local
630 * scope of mainloop(). Get rid of it. */
631 #define SEND writeit( net, &reply, sizeof( reply ));
632 /** error macro; not sure whether we really need this. Uses variables
633 * in the local scope of mainloop(). Get rid of this beast. */
634 #define ERROR { reply.error = htonl(-1); SEND; reply.error = 0; lastpoint = -1; }
636 * Serve a file to a single client.
638 * @todo This beast needs to be split up in many tiny little manageable
639 * pieces. Preferably with a chainsaw.
641 * @param net A network socket, connected to an nbd client
644 int mainloop(int net)
646 struct nbd_request request;
647 struct nbd_reply reply;
652 DEBUG("Entering request loop!\n");
653 reply.magic = htonl(NBD_REPLY_MAGIC);
664 readit(net, &request, sizeof(request));
665 request.from = ntohll(request.from);
666 request.type = ntohl(request.type);
668 if (request.type==NBD_CMD_DISC) { /* Disconnect request */
669 if (difmap) free(difmap) ;
671 close(difffile) ; unlink(difffilename) ; }
672 err("Disconnect request received.") ;
675 len = ntohl(request.len);
677 if (request.magic != htonl(NBD_REQUEST_MAGIC))
678 err("Not enough magic.");
680 err("Request too big!");
682 printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
683 "READ", (unsigned long long)request.from,
684 (unsigned long long)request.from / 512, len);
686 memcpy(reply.handle, request.handle, sizeof(reply.handle));
687 if ((request.from + len) > (OFFT_MAX)) {
688 DEBUG("[Number too large!]");
693 if (((ssize_t)((off_t)request.from + len) > exportsize) ||
694 ((flags & F_READONLY) && request.type)) {
700 if (request.type==1) { /* WRITE */
701 DEBUG("wr: net->buf, ");
702 readit(net, buf, len);
704 if ((autoreadonly == 1) || expwrite(request.from, buf, len)) {
705 DEBUG("Write failed: %m" );
717 if (expread(request.from, buf + sizeof(struct nbd_reply), len)) {
719 DEBUG("Read failed: %m");
726 memcpy(buf, &reply, sizeof(struct nbd_reply));
727 writeit(net, buf, len + sizeof(struct nbd_reply));
733 * Split a single exportfile into multiple ones, if that was asked.
734 * @return 0 on success, -1 on failure
736 int splitexport(void) {
739 for (i=0; i<exportsize; i+=hunksize) {
740 char exportname3[1024];
742 snprintf(exportname3, 1024, "%s.%d", exportname2, (int)i/hunksize);
743 exportname3[1023]='\0';
744 printf( "Opening %s\n", exportname3 );
745 if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) {
746 /* Read WRITE ACCESS was requested by media is only read only */
749 if ((export[i/hunksize] = open(exportname3, O_RDONLY)) == -1)
750 err("Could not open exported file: %m");
754 if (flags & F_COPYONWRITE) {
755 snprintf(difffilename, 1024, "%s-%s-%d.diff",exportname2,clientname,
757 difffilename[1023]='\0';
758 msg3(LOG_INFO,"About to create map and diff file %s",difffilename) ;
759 difffile=open(difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
760 if (difffile<0) err("Could not create diff file (%m)") ;
761 if ((difmap=calloc(exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
762 err("Could not allocate memory") ;
763 for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
770 * Serve a connection.
772 * @todo allow for multithreading, perhaps use libevent.
774 * @param net A network socket connected to an nbd client
776 void serveconnection(int net) {
778 if (exportsize == OFFT_MAX) {
779 exportsize = size_autodetect(export[0]);
781 if (exportsize > OFFT_MAX) {
782 err("Size of exported file is too big\n");
785 msg3(LOG_INFO, "size of exported file/device is %Lu",
786 (unsigned long long)exportsize);
794 * Find the name of the file we have to serve. This will use snprintf()
795 * to put the IP address of the client inside a filename containing
796 * "%s". That name is then written to exportname2
798 * @param net A socket connected to an nbd client
799 * @param clientname a buffer which must be at least 255+1 bytes long;
800 * the IP address (in human-readable format) will be copied in there.
802 void set_peername(int net,char *clientname)
804 struct sockaddr_in addrin;
805 int addrinlen = sizeof( addrin );
808 if (getpeername( net, (struct sockaddr *) &addrin, &addrinlen ) < 0)
809 err("getsockname failed: %m");
810 peername = inet_ntoa(addrin.sin_addr);
811 snprintf(exportname2, 1024, exportname, peername);
812 exportname2[1023]='\0';
814 msg4(LOG_INFO, "connect from %s, assigned file is %s",
815 peername, exportname2);
816 strncpy(clientname,peername,255) ;
820 * Connect the socket, and start to serve. This function will fork()
821 * if a connection from an authorized client is received, and will
824 * @todo modularize this giant beast. Preferably with a chainsaw. Also,
825 * it has no business starting mainloop(); it should connect, and be
828 * @param port the port where we will listen
830 void connectme(unsigned int port)
832 struct sockaddr_in addrin;
834 int addrinlen = sizeof(addrin);
835 int net, sock, newpid, i;
849 snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", port);
850 pidf=fopen(pidfname, "w");
852 fprintf(pidf,"%d", (int)getpid());
856 fprintf(stderr, "Not fatal; continuing");
860 #endif /* NODAEMON */
862 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
865 /* lose the pesky "Address already in use" error message */
866 if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
867 err("setsockopt SO_REUSEADDR");
869 if (setsockopt(sock,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
870 err("setsockopt SO_KEEPALIVE");
873 DEBUG("Waiting for connections... bind, ");
874 addrin.sin_family = AF_INET;
875 addrin.sin_port = htons(port);
876 addrin.sin_addr.s_addr = 0;
877 if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
880 if (listen(sock, 1) < 0)
883 sa.sa_handler = sigchld_handler;
884 sigemptyset(&sa.sa_mask);
885 sa.sa_flags = SA_RESTART;
886 if(sigaction(SIGCHLD, &sa, NULL) == -1)
887 err("sigaction: %m");
888 sa.sa_handler = sigterm_handler;
889 sigemptyset(&sa.sa_mask);
890 sa.sa_flags = SA_RESTART;
891 if(sigaction(SIGTERM, &sa, NULL) == -1)
892 err("sigaction: %m");
893 children=malloc(sizeof(pid_t)*child_arraysize);
894 memset(children, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
895 for(;;) { /* infinite loop */
896 if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
899 set_peername(net,clientname);
900 if (!authorized_client(clientname)) {
901 msg2(LOG_INFO,"Unauthorized client") ;
905 msg2(LOG_INFO,"Authorized client") ;
906 for(i=0;children[i]&&i<child_arraysize;i++);
907 if(i>=child_arraysize) {
910 ptr=realloc(children, sizeof(pid_t)*child_arraysize);
913 memset(children+child_arraysize, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
915 child_arraysize+=DEFAULT_CHILD_ARRAY;
917 msg2(LOG_INFO,"Not enough memory to store child PID");
923 if ((children[i]=fork())<0) {
924 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
928 if (children[i]>0) { /* parent */
929 close(net) ; continue ; }
935 msg2(LOG_INFO,"Starting to serve") ;
936 serveconnection(net) ;
941 * Main entry point...
943 int main(int argc, char *argv[])
945 if (sizeof( struct nbd_request )!=28) {
946 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
952 if (!port) return 1 ;
953 connectme(port); /* serve infinitely */