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.
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/select.h> /* select */
62 #include <sys/wait.h> /* wait */
63 #ifdef HAVE_SYS_IOCTL_H
64 #include <sys/ioctl.h>
66 #include <sys/param.h>
67 #ifdef HAVE_SYS_MOUNT_H
68 #include <sys/mount.h> /* For BLKGETSIZE */
70 #include <signal.h> /* sigaction */
72 #include <netinet/tcp.h>
73 #include <netinet/in.h> /* sockaddr_in, htons, in_addr */
74 #include <netdb.h> /* hostent, gethostby*, getservby* */
81 #include <arpa/inet.h>
91 /* used in cliserv.h, so must come first */
92 #define MY_NAME "nbd_server"
95 /** Default position of the config file */
97 #define SYSCONFDIR "/etc"
99 #define CFILE SYSCONFDIR "/nbd-server/config"
101 /** Where our config file actually is */
102 gchar* config_file_pos;
104 /** What user we're running as */
106 /** What group we're running as */
107 gchar* rungroup=NULL;
109 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */
111 #define msg2(a,b) syslog(a,b)
112 #define msg3(a,b,c) syslog(a,b,c)
113 #define msg4(a,b,c,d) syslog(a,b,c,d)
115 #define msg2(a,b) g_message(b)
116 #define msg3(a,b,c) g_message(b,c)
117 #define msg4(a,b,c,d) g_message(b,c,d)
120 /* Debugging macros */
123 #define DEBUG( a ) printf( a )
124 #define DEBUG2( a,b ) printf( a,b )
125 #define DEBUG3( a,b,c ) printf( a,b,c )
126 #define DEBUG4( a,b,c,d ) printf( a,b,c,d )
129 #define DEBUG2( a,b )
130 #define DEBUG3( a,b,c )
131 #define DEBUG4( a,b,c,d )
133 #ifndef PACKAGE_VERSION
134 #define PACKAGE_VERSION ""
137 * The highest value a variable of type off_t can reach. This is a signed
138 * integer, so set all bits except for the leftmost one.
140 #define OFFT_MAX ~((off_t)1<<(sizeof(off_t)*8-1))
141 #define LINELEN 256 /**< Size of static buffer used to read the
142 authorization file (yuck) */
143 #define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */
144 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
145 #define F_READONLY 1 /**< flag to tell us a file is readonly */
146 #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
147 #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using
149 #define F_AUTOREADONLY 8 /**< flag to tell us a file is set to autoreadonly */
150 #define F_SPARSE 16 /**< flag to tell us copyronwrite should use a sparse file */
151 #define F_SDP 32 /**< flag to tell us the export should be done using the Socket Direct Protocol for RDMA */
152 GHashTable *children;
153 char pidfname[256]; /**< name of our PID file */
154 char pidftemplate[256]; /**< template to be used for the filename of the PID file */
155 char default_authname[] = SYSCONFDIR "/nbd-server/allow"; /**< default name of allow file */
158 * Types of virtuatlization
161 VIRT_NONE=0, /**< No virtualization */
162 VIRT_IPLIT, /**< Literal IP address as part of the filename */
163 VIRT_IPHASH, /**< Replacing all dots in an ip address by a / before
164 doing the same as in IPLIT */
165 VIRT_CIDR, /**< Every subnet in its own directory */
169 * Variables associated with a server.
172 gchar* exportname; /**< (unprocessed) filename of the file we're exporting */
173 off_t expected_size; /**< size of the exported file as it was told to
174 us through configuration */
175 gchar* listenaddr; /**< The IP address we're listening on */
176 unsigned int port; /**< port we're exporting this file at */
177 char* authname; /**< filename of the authorization file */
178 int flags; /**< flags associated with this exported file */
179 unsigned int timeout;/**< how long a connection may be idle
181 int socket; /**< The socket of this server. */
182 VIRT_STYLE virtstyle;/**< The style of virtualization, if any */
183 uint8_t cidrlen; /**< The length of the mask when we use
184 CIDR-style virtualization */
185 gchar* prerun; /**< command to be ran after connecting a client,
186 but before starting to serve */
187 gchar* postrun; /**< command that will be ran after the client
192 * Variables associated with a client socket.
195 int fhandle; /**< file descriptor */
196 off_t startoff; /**< starting offset of this file */
200 off_t exportsize; /**< size of the file we're exporting */
201 char *clientname; /**< peer */
202 char *exportname; /**< (processed) filename of the file we're exporting */
203 GArray *export; /**< array of FILE_INFO of exported files;
204 array size is always 1 unless we're
205 doing the multiple file option */
206 int net; /**< The actual client socket */
207 SERVER *server; /**< The server this client is getting data from */
208 char* difffilename; /**< filename of the copy-on-write file, if any */
209 int difffile; /**< filedescriptor of copyonwrite file. @todo
210 shouldn't this be an array too? (cfr export) Or
211 make -m and -c mutually exclusive */
212 u32 difffilelen; /**< number of pages in difffile */
213 u32 *difmap; /**< see comment on the global difmap for this one */
217 * Type of configuration file values
220 PARAM_INT, /**< This parameter is an integer */
221 PARAM_STRING, /**< This parameter is a string */
222 PARAM_BOOL, /**< This parameter is a boolean */
226 * Configuration file values
229 gchar *paramname; /**< Name of the parameter, as it appears in
231 gboolean required; /**< Whether this is a required (as opposed to
232 optional) parameter */
233 PARAM_TYPE ptype; /**< Type of the parameter. */
234 gpointer target; /**< Pointer to where the data of this
235 parameter should be written. If ptype is
236 PARAM_BOOL, the data is or'ed rather than
238 gint flagval; /**< Flag mask for this parameter in case ptype
243 * Check whether a client is allowed to connect. Works with an authorization
244 * file which contains one line per machine, no wildcards.
246 * @param opts The client who's trying to connect.
247 * @return 0 - authorization refused, 1 - OK
249 int authorized_client(CLIENT *opts) {
250 const char *ERRMSG="Invalid entry '%s' in authfile '%s', so, refusing all connections.";
255 struct in_addr client;
256 struct in_addr cltemp;
259 if ((f=fopen(opts->server->authname,"r"))==NULL) {
260 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
261 opts->server->authname,strerror(errno)) ;
265 inet_aton(opts->clientname, &client);
266 while (fgets(line,LINELEN,f)!=NULL) {
267 if((tmp=index(line, '/'))) {
268 if(strlen(line)<=tmp-line) {
269 msg4(LOG_CRIT, ERRMSG, line, opts->server->authname);
273 if(inet_aton(line,&addr)) {
274 msg4(LOG_CRIT, ERRMSG, line, opts->server->authname);
277 len=strtol(tmp, NULL, 0);
278 addr.s_addr>>=32-len;
279 addr.s_addr<<=32-len;
280 memcpy(&cltemp,&client,sizeof(client));
281 cltemp.s_addr>>=32-len;
282 cltemp.s_addr<<=32-len;
283 if(addr.s_addr == cltemp.s_addr) {
287 if (strncmp(line,opts->clientname,strlen(opts->clientname))==0) {
297 * Read data from a file descriptor into a buffer
299 * @param f a file descriptor
300 * @param buf a buffer
301 * @param len the number of bytes to be read
303 inline void readit(int f, void *buf, size_t len) {
307 if ((res = read(f, buf, len)) <= 0)
308 err("Read failed: %m");
315 * Write data from a buffer into a filedescriptor
317 * @param f a file descriptor
318 * @param buf a buffer containing data
319 * @param len the number of bytes to be written
321 inline void writeit(int f, void *buf, size_t len) {
325 if ((res = write(f, buf, len)) <= 0)
326 err("Send failed: %m");
333 * Print out a message about how to use nbd-server. Split out to a separate
334 * function so that we can call it from multiple places
337 printf("This is nbd-server version " VERSION "\n");
338 printf("Usage: [ip:]port file_to_export [size][kKmM] [-l authorize_file] [-r] [-m] [-c] [-a timeout_sec] [-C configuration file] [-p PID file name] [-o section name]\n"
339 "\t-r|--read-only\t\tread only\n"
340 "\t-m|--multi-file\t\tmultiple file\n"
341 "\t-c|--copy-on-write\tcopy on write\n"
342 "\t-C|--config-file\tspecify an alternate configuration file\n"
343 "\t-l|--authorize-file\tfile with list of hosts that are allowed to\n\t\t\t\tconnect.\n"
344 "\t-a|--idle-time\t\tmaximum idle seconds; server terminates when\n\t\t\t\tidle time exceeded\n"
345 "\t-p|--pid-file\t\tspecify a filename to write our PID to\n"
346 "\t-o|--output-config\toutput a config file section for what you\n\t\t\t\tspecified on the command line, with the\n\t\t\t\tspecified section name\n\n"
347 "\tif port is set to 0, stdin is used (for running from inetd)\n"
348 "\tif file_to_export contains '%%s', it is substituted with the IP\n"
349 "\t\taddress of the machine trying to connect\n"
350 "\tif ip is set, it contains the local IP address on which we're listening.\n\tif not, the server will listen on all local IP addresses\n");
351 printf("Using configuration file %s\n", CFILE);
354 /* Dumps a config file section of the given SERVER*, and exits. */
355 void dump_section(SERVER* serve, gchar* section_header) {
356 printf("[%s]\n", section_header);
357 printf("\texportname = %s\n", serve->exportname);
358 printf("\tlistenaddr = %s\n", serve->listenaddr);
359 printf("\tport = %d\n", serve->port);
360 if(serve->flags & F_READONLY) {
361 printf("\treadonly = true\n");
363 if(serve->flags & F_MULTIFILE) {
364 printf("\tmultifile = true\n");
366 if(serve->flags & F_COPYONWRITE) {
367 printf("\tcopyonwrite = true\n");
369 if(serve->expected_size) {
370 printf("\tfilesize = %lld\n", (long long int)serve->expected_size);
372 if(serve->authname) {
373 printf("\tauthfile = %s\n", serve->authname);
376 printf("\ttimeout = %d\n", serve->timeout);
382 * Parse the command line.
384 * @param argc the argc argument to main()
385 * @param argv the argv argument to main()
387 SERVER* cmdline(int argc, char *argv[]) {
391 struct option long_options[] = {
392 {"read-only", no_argument, NULL, 'r'},
393 {"multi-file", no_argument, NULL, 'm'},
394 {"copy-on-write", no_argument, NULL, 'c'},
395 {"authorize-file", required_argument, NULL, 'l'},
396 {"idle-time", required_argument, NULL, 'a'},
397 {"config-file", required_argument, NULL, 'C'},
398 {"pid-file", required_argument, NULL, 'p'},
399 {"output-config", required_argument, NULL, 'o'},
406 gboolean do_output=FALSE;
407 gchar* section_header="";
413 serve=g_new0(SERVER, 1);
414 serve->authname = g_strdup(default_authname);
415 serve->virtstyle=VIRT_IPLIT;
416 while((c=getopt_long(argc, argv, "-a:C:cl:mo:rp:", long_options, &i))>=0) {
419 /* non-option argument */
420 switch(nonspecial++) {
422 addr_port=g_strsplit(optarg, ":", 2);
424 serve->port=strtol(addr_port[1], NULL, 0);
425 serve->listenaddr=g_strdup(addr_port[0]);
427 serve->listenaddr=g_strdup("0.0.0.0");
428 serve->port=strtol(addr_port[0], NULL, 0);
430 g_strfreev(addr_port);
433 serve->exportname = g_strdup(optarg);
434 if(serve->exportname[0] != '/') {
435 fprintf(stderr, "E: The to be exported file needs to be an absolute filename!\n");
440 last=strlen(optarg)-1;
442 if (suffix == 'k' || suffix == 'K' ||
443 suffix == 'm' || suffix == 'M')
445 es = (off_t)atol(optarg);
453 serve->expected_size = es;
458 serve->flags |= F_READONLY;
461 serve->flags |= F_MULTIFILE;
465 section_header = g_strdup(optarg);
468 strncpy(pidftemplate, optarg, 256);
471 serve->flags |=F_COPYONWRITE;
474 g_free(config_file_pos);
475 config_file_pos=g_strdup(optarg);
478 g_free(serve->authname);
479 serve->authname=g_strdup(optarg);
482 serve->timeout=strtol(optarg, NULL, 0);
490 /* What's left: the port to export, the name of the to be exported
491 * file, and, optionally, the size of the file, in that order. */
498 g_critical("Need a complete configuration on the command line to output a config file section!");
501 dump_section(serve, section_header);
507 * Error codes for config file parsing
510 CFILE_NOTFOUND, /**< The configuration file is not found */
511 CFILE_MISSING_GENERIC, /**< The (required) group "generic" is missing */
512 CFILE_KEY_MISSING, /**< A (required) key is missing */
513 CFILE_VALUE_INVALID, /**< A value is syntactically invalid */
514 CFILE_VALUE_UNSUPPORTED,/**< A value is not supported in this build */
515 CFILE_PROGERR /**< Programmer error */
519 * Remove a SERVER from memory. Used from the hash table
521 void remove_server(gpointer s) {
525 g_free(server->exportname);
527 g_free(server->authname);
532 * Parse the config file.
534 * @param f the name of the config file
535 * @param e a GError. @see CFILE_ERRORS for what error values this function can
537 * @return a Array of SERVER* pointers, If the config file is empty or does not
538 * exist, returns an empty GHashTable; if the config file contains an
539 * error, returns NULL, and e is set appropriately
541 GArray* parse_cfile(gchar* f, GError** e) {
542 const char* DEFAULT_ERROR = "Could not parse %s in group %s: %s";
543 const char* MISSING_REQUIRED_ERROR = "Could not find required value %s in group %s: %s";
545 gchar *virtstyle=NULL;
547 { "exportname", TRUE, PARAM_STRING, NULL, 0 },
548 { "port", TRUE, PARAM_INT, NULL, 0 },
549 { "authfile", FALSE, PARAM_STRING, NULL, 0 },
550 { "timeout", FALSE, PARAM_INT, NULL, 0 },
551 { "filesize", FALSE, PARAM_INT, NULL, 0 },
552 { "virtstyle", FALSE, PARAM_STRING, NULL, 0 },
553 { "prerun", FALSE, PARAM_STRING, NULL, 0 },
554 { "postrun", FALSE, PARAM_STRING, NULL, 0 },
555 { "readonly", FALSE, PARAM_BOOL, NULL, F_READONLY },
556 { "multifile", FALSE, PARAM_BOOL, NULL, F_MULTIFILE },
557 { "copyonwrite", FALSE, PARAM_BOOL, NULL, F_COPYONWRITE },
558 { "sparse_cow", FALSE, PARAM_BOOL, NULL, F_SPARSE },
559 { "sdp", FALSE, PARAM_BOOL, NULL, F_SDP },
560 { "listenaddr", FALSE, PARAM_STRING, NULL, 0 },
562 const int lp_size=sizeof(lp)/sizeof(PARAM);
564 { "user", FALSE, PARAM_STRING, &runuser, 0 },
565 { "group", FALSE, PARAM_STRING, &rungroup, 0 },
568 int p_size=sizeof(gp)/sizeof(PARAM);
571 const char *err_msg=NULL;
580 errdomain = g_quark_from_string("parse_cfile");
581 cfile = g_key_file_new();
582 retval = g_array_new(FALSE, TRUE, sizeof(SERVER));
583 if(!g_key_file_load_from_file(cfile, f, G_KEY_FILE_KEEP_COMMENTS |
584 G_KEY_FILE_KEEP_TRANSLATIONS, &err)) {
585 g_set_error(e, errdomain, CFILE_NOTFOUND, "Could not open config file.");
586 g_key_file_free(cfile);
589 startgroup = g_key_file_get_start_group(cfile);
590 if(!startgroup || strcmp(startgroup, "generic")) {
591 g_set_error(e, errdomain, CFILE_MISSING_GENERIC, "Config file does not contain the [generic] group!");
592 g_key_file_free(cfile);
595 groups = g_key_file_get_groups(cfile, NULL);
596 for(i=0;groups[i];i++) {
597 memset(&s, '\0', sizeof(SERVER));
598 lp[0].target=&(s.exportname);
599 lp[1].target=&(s.port);
600 lp[2].target=&(s.authname);
601 lp[3].target=&(s.timeout);
602 lp[4].target=&(s.expected_size);
603 lp[5].target=&(virtstyle);
604 lp[6].target=&(s.prerun);
605 lp[7].target=&(s.postrun);
606 lp[8].target=lp[9].target=lp[10].target=
607 lp[11].target=lp[12].target=&(s.flags);
608 lp[13].target=&(s.listenaddr);
610 /* After the [generic] group, start parsing exports */
615 for(j=0;j<p_size;j++) {
616 g_assert(p[j].target != NULL);
617 g_assert(p[j].ptype==PARAM_INT||p[j].ptype==PARAM_STRING||p[j].ptype==PARAM_BOOL);
620 *((gint*)p[j].target) =
621 g_key_file_get_integer(cfile,
627 *((gchar**)p[j].target) =
628 g_key_file_get_string(cfile,
634 value = g_key_file_get_boolean(cfile,
636 p[j].paramname, &err);
639 *((gint*)p[j].target) |= p[j].flagval;
641 *((gint*)p[j].target) &= ~(p[j].flagval);
647 if(err->code == G_KEY_FILE_ERROR_KEY_NOT_FOUND) {
649 /* Ignore not-found error for optional values */
653 err_msg = MISSING_REQUIRED_ERROR;
656 err_msg = DEFAULT_ERROR;
658 g_set_error(e, errdomain, CFILE_VALUE_INVALID, err_msg, p[j].paramname, groups[i], err->message);
659 g_array_free(retval, TRUE);
661 g_key_file_free(cfile);
666 if(!strncmp(virtstyle, "none", 4)) {
667 s.virtstyle=VIRT_NONE;
668 } else if(!strncmp(virtstyle, "ipliteral", 9)) {
669 s.virtstyle=VIRT_IPLIT;
670 } else if(!strncmp(virtstyle, "iphash", 6)) {
671 s.virtstyle=VIRT_IPHASH;
672 } else if(!strncmp(virtstyle, "cidrhash", 8)) {
673 s.virtstyle=VIRT_CIDR;
674 if(strlen(virtstyle)<10) {
675 g_set_error(e, errdomain, CFILE_VALUE_INVALID, "Invalid value %s for parameter virtstyle in group %s: missing length", virtstyle, groups[i]);
676 g_array_free(retval, TRUE);
677 g_key_file_free(cfile);
680 s.cidrlen=strtol(virtstyle+8, NULL, 0);
682 g_set_error(e, errdomain, CFILE_VALUE_INVALID, "Invalid value %s for parameter virtstyle in group %s", virtstyle, groups[i]);
683 g_array_free(retval, TRUE);
684 g_key_file_free(cfile);
688 s.virtstyle=VIRT_IPLIT;
690 /* Don't need to free this, it's not our string */
692 /* Don't append values for the [generic] group */
695 s.listenaddr = g_strdup("0.0.0.0");
697 g_array_append_val(retval, s);
700 if(s.flags & F_SDP) {
701 g_set_error(e, errdomain, CFILE_VALUE_UNSUPPORTED, "This nbd-server was built without support for SDP, yet group %s uses it", groups[i]);
702 g_array_free(retval, TRUE);
703 g_key_file_free(cfile);
712 * Signal handler for SIGCHLD
713 * @param s the signal we're handling (must be SIGCHLD, or something
716 void sigchld_handler(int s) {
721 while((pid=waitpid(-1, &status, WNOHANG)) > 0) {
722 if(WIFEXITED(status)) {
723 msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status));
725 i=g_hash_table_lookup(children, &pid);
727 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld", (long)pid);
729 DEBUG2("Removing %d from the list of children", pid);
730 g_hash_table_remove(children, &pid);
736 * Kill a child. Called from sigterm_handler::g_hash_table_foreach.
739 * @param value the value corresponding to the above key
740 * @param user_data a pointer which we always set to 1, so that we know what
743 void killchild(gpointer key, gpointer value, gpointer user_data) {
745 int *parent=user_data;
752 * Handle SIGTERM and dispatch it to our children
753 * @param s the signal we're handling (must be SIGTERM, or something
754 * is severely wrong).
756 void sigterm_handler(int s) {
759 g_hash_table_foreach(children, killchild, &parent);
769 * Detect the size of a file.
771 * @param fhandle An open filedescriptor
772 * @return the size of the file, or OFFT_MAX if detection was
775 off_t size_autodetect(int fhandle) {
777 unsigned long sectors;
778 struct stat stat_buf;
781 #ifdef HAVE_SYS_MOUNT_H
782 #ifdef HAVE_SYS_IOCTL_H
784 DEBUG("looking for export size with ioctl BLKGETSIZE\n");
785 if (!ioctl(fhandle, BLKGETSIZE, §ors) && sectors) {
786 es = (off_t)sectors * (off_t)512;
789 #endif /* BLKGETSIZE */
790 #endif /* HAVE_SYS_IOCTL_H */
791 #endif /* HAVE_SYS_MOUNT_H */
793 DEBUG("looking for fhandle size with fstat\n");
794 stat_buf.st_size = 0;
795 error = fstat(fhandle, &stat_buf);
797 if(stat_buf.st_size > 0)
798 return (off_t)stat_buf.st_size;
800 err("fstat failed: %m");
803 DEBUG("looking for fhandle size with lseek SEEK_END\n");
804 es = lseek(fhandle, (off_t)0, SEEK_END);
805 if (es > ((off_t)0)) {
808 DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
811 err("Could not find size of exported block device: %m");
816 * Get the file handle and offset, given an export offset.
818 * @param export An array of export files
819 * @param a The offset to get corresponding file/offset for
820 * @param fhandle [out] File descriptor
821 * @param foffset [out] Offset into fhandle
822 * @param maxbytes [out] Tells how many bytes can be read/written
823 * from fhandle starting at foffset (0 if there is no limit)
824 * @return 0 on success, -1 on failure
826 int get_filepos(GArray* export, off_t a, int* fhandle, off_t* foffset, size_t* maxbytes ) {
827 /* Negative offset not allowed */
831 /* Binary search for last file with starting offset <= a */
834 int end = export->len - 1;
835 while( start <= end ) {
836 int mid = (start + end) / 2;
837 fi = g_array_index(export, FILE_INFO, mid);
838 if( fi.startoff < a ) {
840 } else if( fi.startoff > a ) {
848 /* end should never go negative, since first startoff is 0 and a >= 0 */
851 fi = g_array_index(export, FILE_INFO, end);
852 *fhandle = fi.fhandle;
853 *foffset = a - fi.startoff;
855 if( end+1 < export->len ) {
856 FILE_INFO fi_next = g_array_index(export, FILE_INFO, end+1);
857 *maxbytes = fi_next.startoff - a;
864 * seek to a position in a file, with error handling.
865 * @param handle a filedescriptor
866 * @param a position to seek to
867 * @todo get rid of this; lastpoint is a global variable right now, but it
868 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
871 void myseek(int handle,off_t a) {
872 if (lseek(handle, a, SEEK_SET) < 0) {
873 err("Can not seek locally!\n");
878 * Write an amount of bytes at a given offset to the right file. This
879 * abstracts the write-side of the multiple file option.
881 * @param a The offset where the write should start
882 * @param buf The buffer to write from
883 * @param len The length of buf
884 * @param client The client we're serving for
885 * @return The number of bytes actually written, or -1 in case of an error
887 ssize_t rawexpwrite(off_t a, char *buf, size_t len, CLIENT *client) {
892 if(get_filepos(client->export, a, &fhandle, &foffset, &maxbytes))
894 if(maxbytes && len > maxbytes)
897 DEBUG4("(WRITE to fd %d offset %llu len %u), ", fhandle, foffset, len);
899 myseek(fhandle, foffset);
900 return write(fhandle, buf, len);
904 * Call rawexpwrite repeatedly until all data has been written.
905 * @return 0 on success, nonzero on failure
907 int rawexpwrite_fully(off_t a, char *buf, size_t len, CLIENT *client) {
910 while(len > 0 && (ret=rawexpwrite(a, buf, len, client)) > 0 ) {
915 return (ret < 0 || len != 0);
919 * Read an amount of bytes at a given offset from the right file. This
920 * abstracts the read-side of the multiple files option.
922 * @param a The offset where the read should start
923 * @param buf A buffer to read into
924 * @param len The size of buf
925 * @param client The client we're serving for
926 * @return The number of bytes actually read, or -1 in case of an
929 ssize_t rawexpread(off_t a, char *buf, size_t len, CLIENT *client) {
934 if(get_filepos(client->export, a, &fhandle, &foffset, &maxbytes))
936 if(maxbytes && len > maxbytes)
939 DEBUG4("(READ from fd %d offset %llu len %u), ", fhandle, foffset, len);
941 myseek(fhandle, foffset);
942 return read(fhandle, buf, len);
946 * Call rawexpread repeatedly until all data has been read.
947 * @return 0 on success, nonzero on failure
949 int rawexpread_fully(off_t a, char *buf, size_t len, CLIENT *client) {
952 while(len > 0 && (ret=rawexpread(a, buf, len, client)) > 0 ) {
957 return (ret < 0 || len != 0);
961 * Read an amount of bytes at a given offset from the right file. This
962 * abstracts the read-side of the copyonwrite stuff, and calls
963 * rawexpread() with the right parameters to do the actual work.
964 * @param a The offset where the read should start
965 * @param buf A buffer to read into
966 * @param len The size of buf
967 * @param client The client we're going to read for
968 * @return 0 on success, nonzero on failure
970 int expread(off_t a, char *buf, size_t len, CLIENT *client) {
972 off_t mapcnt, mapl, maph, pagestart;
974 if (!(client->server->flags & F_COPYONWRITE))
975 return(rawexpread_fully(a, buf, len, client));
976 DEBUG3("Asked to read %d bytes at %llu.\n", len, (unsigned long long)a);
978 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
980 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
981 pagestart=mapcnt*DIFFPAGESIZE;
983 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
984 len : (size_t)DIFFPAGESIZE-offset;
985 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
986 DEBUG3("Page %llu is at %lu\n", (unsigned long long)mapcnt,
987 (unsigned long)(client->difmap[mapcnt]));
988 myseek(client->difffile, client->difmap[mapcnt]*DIFFPAGESIZE+offset);
989 if (read(client->difffile, buf, rdlen) != rdlen) return -1;
990 } else { /* the block is not there */
991 DEBUG2("Page %llu is not here, we read the original one\n",
992 (unsigned long long)mapcnt);
993 if(rawexpread_fully(a, buf, rdlen, client)) return -1;
995 len-=rdlen; a+=rdlen; buf+=rdlen;
1001 * Write an amount of bytes at a given offset to the right file. This
1002 * abstracts the write-side of the copyonwrite option, and calls
1003 * rawexpwrite() with the right parameters to do the actual work.
1005 * @param a The offset where the write should start
1006 * @param buf The buffer to write from
1007 * @param len The length of buf
1008 * @param client The client we're going to write for.
1009 * @return 0 on success, nonzero on failure
1011 int expwrite(off_t a, char *buf, size_t len, CLIENT *client) {
1012 char pagebuf[DIFFPAGESIZE];
1013 off_t mapcnt,mapl,maph;
1018 if (!(client->server->flags & F_COPYONWRITE))
1019 return(rawexpwrite_fully(a, buf, len, client));
1020 DEBUG3("Asked to write %d bytes at %llu.\n", len, (unsigned long long)a);
1022 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
1024 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
1025 pagestart=mapcnt*DIFFPAGESIZE ;
1026 offset=a-pagestart ;
1027 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
1028 len : (size_t)DIFFPAGESIZE-offset;
1030 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
1031 DEBUG3("Page %llu is at %lu\n", (unsigned long long)mapcnt,
1032 (unsigned long)(client->difmap[mapcnt])) ;
1033 myseek(client->difffile,
1034 client->difmap[mapcnt]*DIFFPAGESIZE+offset);
1035 if (write(client->difffile, buf, wrlen) != wrlen) return -1 ;
1036 } else { /* the block is not there */
1037 myseek(client->difffile,client->difffilelen*DIFFPAGESIZE) ;
1038 client->difmap[mapcnt]=(client->server->flags&F_SPARSE)?mapcnt:client->difffilelen++;
1039 DEBUG3("Page %llu is not here, we put it at %lu\n",
1040 (unsigned long long)mapcnt,
1041 (unsigned long)(client->difmap[mapcnt]));
1042 rdlen=DIFFPAGESIZE ;
1043 if (rawexpread_fully(pagestart, pagebuf, rdlen, client))
1045 memcpy(pagebuf+offset,buf,wrlen) ;
1046 if (write(client->difffile, pagebuf, DIFFPAGESIZE) !=
1050 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
1056 * Do the initial negotiation.
1058 * @param client The client we're negotiating with.
1060 void negotiate(CLIENT *client) {
1063 u32 flags = NBD_FLAG_HAS_FLAGS;
1065 memset(zeros, '\0', sizeof(zeros));
1066 if (write(client->net, INIT_PASSWD, 8) < 0)
1067 err("Negotiation failed: %m");
1068 cliserv_magic = htonll(cliserv_magic);
1069 if (write(client->net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
1070 err("Negotiation failed: %m");
1071 size_host = htonll((u64)(client->exportsize));
1072 if (write(client->net, &size_host, 8) < 0)
1073 err("Negotiation failed: %m");
1074 if (client->server->flags & F_READONLY)
1075 flags |= NBD_FLAG_READ_ONLY;
1076 flags = htonl(flags);
1077 if (write(client->net, &flags, 4) < 0)
1078 err("Negotiation failed: %m");
1079 if (write(client->net, zeros, 124) < 0)
1080 err("Negotiation failed: %m");
1083 /** sending macro. */
1084 #define SEND(net,reply) writeit( net, &reply, sizeof( reply ));
1086 #define ERROR(client,reply,errcode) { reply.error = htonl(errcode); SEND(client->net,reply); reply.error = 0; }
1088 * Serve a file to a single client.
1090 * @todo This beast needs to be split up in many tiny little manageable
1091 * pieces. Preferably with a chainsaw.
1093 * @param client The client we're going to serve to.
1094 * @return when the client disconnects
1096 int mainloop(CLIENT *client) {
1097 struct nbd_request request;
1098 struct nbd_reply reply;
1099 gboolean go_on=TRUE;
1104 DEBUG("Entering request loop!\n");
1105 reply.magic = htonl(NBD_REPLY_MAGIC);
1114 if (client->server->timeout)
1115 alarm(client->server->timeout);
1116 readit(client->net, &request, sizeof(request));
1117 request.from = ntohll(request.from);
1118 request.type = ntohl(request.type);
1120 if (request.type==NBD_CMD_DISC) {
1121 msg2(LOG_INFO, "Disconnect request received.");
1122 if (client->server->flags & F_COPYONWRITE) {
1123 if (client->difmap) g_free(client->difmap) ;
1124 close(client->difffile);
1125 unlink(client->difffilename);
1126 free(client->difffilename);
1132 len = ntohl(request.len);
1134 if (request.magic != htonl(NBD_REQUEST_MAGIC))
1135 err("Not enough magic.");
1136 if (len > BUFSIZE + sizeof(struct nbd_reply))
1137 err("Request too big!");
1139 printf("%s from %llu (%llu) len %d, ", request.type ? "WRITE" :
1140 "READ", (unsigned long long)request.from,
1141 (unsigned long long)request.from / 512, len);
1143 memcpy(reply.handle, request.handle, sizeof(reply.handle));
1144 if ((request.from + len) > (OFFT_MAX)) {
1145 DEBUG("[Number too large!]");
1146 ERROR(client, reply, EINVAL);
1150 if (((ssize_t)((off_t)request.from + len) > client->exportsize)) {
1152 ERROR(client, reply, EINVAL);
1156 if (request.type==NBD_CMD_WRITE) {
1157 DEBUG("wr: net->buf, ");
1158 readit(client->net, buf, len);
1159 DEBUG("buf->exp, ");
1160 if ((client->server->flags & F_READONLY) ||
1161 (client->server->flags & F_AUTOREADONLY)) {
1162 DEBUG("[WRITE to READONLY!]");
1163 ERROR(client, reply, EPERM);
1166 if (expwrite(request.from, buf, len, client)) {
1167 DEBUG("Write failed: %m" );
1168 ERROR(client, reply, errno);
1171 SEND(client->net, reply);
1177 DEBUG("exp->buf, ");
1178 if (expread(request.from, buf + sizeof(struct nbd_reply), len, client)) {
1179 DEBUG("Read failed: %m");
1180 ERROR(client, reply, errno);
1184 DEBUG("buf->net, ");
1185 memcpy(buf, &reply, sizeof(struct nbd_reply));
1186 writeit(client->net, buf, len + sizeof(struct nbd_reply));
1193 * Set up client export array, which is an array of FILE_INFO.
1194 * Also, split a single exportfile into multiple ones, if that was asked.
1195 * @param client information on the client which we want to setup export for
1197 void setupexport(CLIENT* client) {
1199 off_t laststartoff = 0, lastsize = 0;
1200 int multifile = (client->server->flags & F_MULTIFILE);
1202 client->export = g_array_new(TRUE, TRUE, sizeof(FILE_INFO));
1204 /* If multi-file, open as many files as we can.
1205 * If not, open exactly one file.
1206 * Calculate file sizes as we go to get total size. */
1210 mode_t mode = (client->server->flags & F_READONLY) ? O_RDONLY : O_RDWR;
1213 tmpname=g_strdup_printf("%s.%d", client->exportname, i);
1215 tmpname=g_strdup(client->exportname);
1217 DEBUG2( "Opening %s\n", tmpname );
1218 fi.fhandle = open(tmpname, mode);
1219 if(fi.fhandle == -1 && mode == O_RDWR) {
1220 /* Try again because maybe media was read-only */
1221 fi.fhandle = open(tmpname, O_RDONLY);
1222 if(fi.fhandle != -1) {
1223 /* Opening the base file in copyonwrite mode is
1225 if(!(client->server->flags & F_COPYONWRITE)) {
1226 client->server->flags |= F_AUTOREADONLY;
1227 client->server->flags |= F_READONLY;
1231 if(fi.fhandle == -1) {
1232 if(multifile && i>0)
1234 err("Could not open exported file: %m");
1236 fi.startoff = laststartoff + lastsize;
1237 g_array_append_val(client->export, fi);
1240 /* Starting offset and size of this file will be used to
1241 * calculate starting offset of next file */
1242 laststartoff = fi.startoff;
1243 lastsize = size_autodetect(fi.fhandle);
1249 /* Set export size to total calculated size */
1250 client->exportsize = laststartoff + lastsize;
1252 /* Export size may be overridden */
1253 if(client->server->expected_size) {
1254 /* desired size must be <= total calculated size */
1255 if(client->server->expected_size > client->exportsize) {
1256 err("Size of exported file is too big\n");
1259 client->exportsize = client->server->expected_size;
1262 msg3(LOG_INFO, "Size of exported file/device is %llu", (unsigned long long)client->exportsize);
1264 msg3(LOG_INFO, "Total number of files: %d", i);
1268 int copyonwrite_prepare(CLIENT* client) {
1270 if ((client->difffilename = malloc(1024))==NULL)
1271 err("Failed to allocate string for diff file name");
1272 snprintf(client->difffilename, 1024, "%s-%s-%d.diff",client->exportname,client->clientname,
1274 client->difffilename[1023]='\0';
1275 msg3(LOG_INFO,"About to create map and diff file %s",client->difffilename) ;
1276 client->difffile=open(client->difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
1277 if (client->difffile<0) err("Could not create diff file (%m)") ;
1278 if ((client->difmap=calloc(client->exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
1279 err("Could not allocate memory") ;
1280 for (i=0;i<client->exportsize/DIFFPAGESIZE;i++) client->difmap[i]=(u32)-1 ;
1286 * Run a command. This is used for the ``prerun'' and ``postrun'' config file
1289 * @param command the command to be ran. Read from the config file
1290 * @param file the file name we're about to export
1292 int do_run(gchar* command, gchar* file) {
1296 if(command && *command) {
1297 cmd = g_strdup_printf(command, file);
1305 * Serve a connection.
1307 * @todo allow for multithreading, perhaps use libevent. Not just yet, though;
1308 * follow the road map.
1310 * @param client a connected client
1312 void serveconnection(CLIENT *client) {
1313 if(do_run(client->server->prerun, client->exportname)) {
1316 setupexport(client);
1318 if (client->server->flags & F_COPYONWRITE) {
1319 copyonwrite_prepare(client);
1322 setmysockopt(client->net);
1325 do_run(client->server->postrun, client->exportname);
1329 * Find the name of the file we have to serve. This will use g_strdup_printf
1330 * to put the IP address of the client inside a filename containing
1331 * "%s" (in the form as specified by the "virtstyle" option). That name
1332 * is then written to client->exportname.
1334 * @param net A socket connected to an nbd client
1335 * @param client information about the client. The IP address in human-readable
1336 * format will be written to a new char* buffer, the address of which will be
1337 * stored in client->clientname.
1339 void set_peername(int net, CLIENT *client) {
1340 struct sockaddr_in addrin;
1341 struct sockaddr_in netaddr;
1342 size_t addrinlen = sizeof( addrin );
1348 if (getpeername(net, (struct sockaddr *) &addrin, (socklen_t *)&addrinlen) < 0)
1349 err("getsockname failed: %m");
1350 peername = g_strdup(inet_ntoa(addrin.sin_addr));
1351 switch(client->server->virtstyle) {
1353 client->exportname=g_strdup(client->server->exportname);
1356 for(i=0;i<strlen(peername);i++) {
1357 if(peername[i]=='.') {
1362 client->exportname=g_strdup_printf(client->server->exportname, peername);
1365 memcpy(&netaddr, &addrin, addrinlen);
1366 netaddr.sin_addr.s_addr>>=32-(client->server->cidrlen);
1367 netaddr.sin_addr.s_addr<<=32-(client->server->cidrlen);
1368 netname = inet_ntoa(netaddr.sin_addr);
1369 tmp=g_strdup_printf("%s/%s", netname, peername);
1370 client->exportname=g_strdup_printf(client->server->exportname, tmp);
1374 msg4(LOG_INFO, "connect from %s, assigned file is %s",
1375 peername, client->exportname);
1376 client->clientname=g_strdup(peername);
1382 * @param data a pointer to pid_t which should be freed
1384 void destroy_pid_t(gpointer data) {
1389 * Loop through the available servers, and serve them. Never returns.
1391 int serveloop(GArray* servers) {
1392 struct sockaddr_in addrin;
1393 socklen_t addrinlen=sizeof(addrin);
1402 * Set up the master fd_set. The set of descriptors we need
1403 * to select() for never changes anyway and it buys us a *lot*
1404 * of time to only build this once. However, if we ever choose
1405 * to not fork() for clients anymore, we may have to revisit
1410 for(i=0;i<servers->len;i++) {
1411 sock=(g_array_index(servers, SERVER, i)).socket;
1412 FD_SET(sock, &mset);
1413 max=sock>max?sock:max;
1420 memcpy(&rset, &mset, sizeof(fd_set));
1421 if(select(max+1, &rset, NULL, NULL, NULL)>0) {
1423 for(i=0;i<servers->len;i++) {
1424 serve=&(g_array_index(servers, SERVER, i));
1425 if(FD_ISSET(serve->socket, &rset)) {
1427 if ((net=accept(serve->socket, (struct sockaddr *) &addrin, &addrinlen)) < 0)
1430 if((sock_flags = fcntl(net, F_GETFL, 0))==-1) {
1431 err("fcntl F_GETFL");
1433 if(fcntl(net, F_SETFL, sock_flags &~O_NONBLOCK)==-1) {
1434 err("fcntl F_SETFL ~O_NONBLOCK");
1436 client = g_malloc(sizeof(CLIENT));
1437 client->server=serve;
1438 client->exportsize=OFFT_MAX;
1440 set_peername(net, client);
1441 if (!authorized_client(client)) {
1442 msg2(LOG_INFO,"Unauthorized client") ;
1446 msg2(LOG_INFO,"Authorized client") ;
1447 pid=g_malloc(sizeof(pid_t));
1449 if ((*pid=fork())<0) {
1450 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
1454 if (*pid>0) { /* parent */
1456 g_hash_table_insert(children, pid, pid);
1460 g_hash_table_destroy(children);
1461 for(i=0;i<servers->len;i++) {
1462 serve=&g_array_index(servers, SERVER, i);
1463 close(serve->socket);
1465 /* FALSE does not free the
1466 actual data. This is required,
1467 because the client has a
1468 direct reference into that
1469 data, and otherwise we get a
1471 g_array_free(servers, FALSE);
1473 msg2(LOG_INFO,"Starting to serve");
1474 serveconnection(client);
1483 * Connect a server's socket.
1485 * @param serve the server we want to connect.
1487 void setup_serve(SERVER *serve) {
1488 struct sockaddr_in addrin;
1489 struct sigaction sa;
1490 int addrinlen = sizeof(addrin);
1501 if ((serve->flags) && F_SDP) {
1505 if ((serve->socket = socket(af, SOCK_STREAM, IPPROTO_TCP)) < 0)
1508 /* lose the pesky "Address already in use" error message */
1509 if (setsockopt(serve->socket,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
1510 err("setsockopt SO_REUSEADDR");
1512 if (setsockopt(serve->socket,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
1513 err("setsockopt SO_KEEPALIVE");
1516 /* make the listening socket non-blocking */
1517 if ((sock_flags = fcntl(serve->socket, F_GETFL, 0)) == -1) {
1518 err("fcntl F_GETFL");
1520 if (fcntl(serve->socket, F_SETFL, sock_flags | O_NONBLOCK) == -1) {
1521 err("fcntl F_SETFL O_NONBLOCK");
1524 DEBUG("Waiting for connections... bind, ");
1525 addrin.sin_family = AF_INET;
1527 if(serve->flags & F_SDP) {
1528 addrin.sin_family = AF_INET_SDP;
1531 addrin.sin_port = htons(serve->port);
1532 if(!inet_aton(serve->listenaddr, &(addrin.sin_addr)))
1533 err("could not parse listen address");
1534 if (bind(serve->socket, (struct sockaddr *) &addrin, addrinlen) < 0)
1537 if (listen(serve->socket, 1) < 0)
1539 sa.sa_handler = sigchld_handler;
1540 sigemptyset(&sa.sa_mask);
1541 sa.sa_flags = SA_RESTART;
1542 if(sigaction(SIGCHLD, &sa, NULL) == -1)
1543 err("sigaction: %m");
1544 sa.sa_handler = sigterm_handler;
1545 sigemptyset(&sa.sa_mask);
1546 sa.sa_flags = SA_RESTART;
1547 if(sigaction(SIGTERM, &sa, NULL) == -1)
1548 err("sigaction: %m");
1552 * Connect our servers.
1554 void setup_servers(GArray* servers) {
1557 for(i=0;i<servers->len;i++) {
1558 setup_serve(&(g_array_index(servers, SERVER, i)));
1560 children=g_hash_table_new_full(g_int_hash, g_int_equal, NULL, destroy_pid_t);
1564 * Go daemon (unless we specified at compile time that we didn't want this)
1565 * @param serve the first server of our configuration. If its port is zero,
1566 * then do not daemonize, because we're doing inetd then. This parameter
1567 * is only used to create a PID file of the form
1568 * /var/run/nbd-server.<port>.pid; it's not modified in any way.
1570 #if !defined(NODAEMON) && !defined(NOFORK)
1571 void daemonize(SERVER* serve) {
1574 if(serve && !(serve->port)) {
1580 if(!*pidftemplate) {
1582 strncpy(pidftemplate, "/var/run/nbd-server.%d.pid", 255);
1584 strncpy(pidftemplate, "/var/run/nbd-server.pid", 255);
1587 snprintf(pidfname, 255, pidftemplate, serve ? serve->port : 0);
1588 pidf=fopen(pidfname, "w");
1590 fprintf(pidf,"%d\n", (int)getpid());
1594 fprintf(stderr, "Not fatal; continuing");
1598 #define daemonize(serve)
1599 #endif /* !defined(NODAEMON) && !defined(NOFORK) */
1602 * Everything beyond this point (in the file) is run in non-daemon mode.
1603 * The stuff above daemonize() isn't.
1606 void serve_err(SERVER* serve, const char* msg) G_GNUC_NORETURN;
1608 void serve_err(SERVER* serve, const char* msg) {
1609 g_message("Export of %s on port %d failed:", serve->exportname,
1615 * Set up user-ID and/or group-ID
1617 void dousers(void) {
1621 gr=getgrnam(rungroup);
1623 g_message("Invalid group name: %s", rungroup);
1626 if(setgid(gr->gr_gid)<0) {
1627 g_message("Could not set GID: %s", strerror(errno));
1632 pw=getpwnam(runuser);
1634 g_message("Invalid user name: %s", runuser);
1637 if(setuid(pw->pw_uid)<0) {
1638 g_message("Could not set UID: %s", strerror(errno));
1645 * Main entry point...
1647 int main(int argc, char *argv[]) {
1652 if (sizeof( struct nbd_request )!=28) {
1653 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
1654 exit(EXIT_FAILURE) ;
1657 memset(pidftemplate, '\0', 256);
1660 config_file_pos = g_strdup(CFILE);
1661 serve=cmdline(argc, argv);
1662 servers = parse_cfile(config_file_pos, &err);
1663 if(!servers || !servers->len) {
1664 g_warning("Could not parse config file: %s",
1665 err ? err->message : "Unknown error");
1668 g_array_append_val(servers, *serve);
1670 if (!(serve->port)) {
1673 /* You really should define ISSERVER if you're going to use
1674 * inetd mode, but if you don't, closing stdout and stderr
1675 * (which inetd had connected to the client socket) will let it
1679 open("/dev/null", O_WRONLY);
1680 open("/dev/null", O_WRONLY);
1682 client=g_malloc(sizeof(CLIENT));
1683 client->server=serve;
1685 client->exportsize=OFFT_MAX;
1686 set_peername(0,client);
1687 serveconnection(client);
1691 if((!serve) && (!servers||!servers->len)) {
1692 g_message("Nothing to do! Bye!");
1696 setup_servers(servers);