*
* Copyright 1996-1998 Pavel Machek, distribute under GPL
* <pavel@atrey.karlin.mff.cuni.cz>
+ * Copyright 2001-2004 Wouter Verhelst <wouter@debian.org>
+ * Copyright 2002 Anton Altaparmakov <aia21@cam.ac.uk>
*
* Version 1.0 - hopefully 64-bit-clean
* Version 1.1 - merging enhancements from Josh Parsons, <josh@coombs.anu.edu.au>
* with make FSCHOICE=-DFS_32BIT nbd-server. (I don't have the
* original autoconf input file, or I would make it a configure
* option.) Ken Yap <ken@nlc.net.au>.
+ * Version 1.6 - fix autodetection of block device size and really make 64 bit
+ * clean on 32 bit machines. Anton Altaparmakov <aia21@cam.ac.uk>
+ * Version 2.0 - Version synchronised with client
+ * Version 2.1 - Reap zombie client processes when they exit. Removed
+ * (uncommented) the _IO magic, it's no longer necessary. Wouter
+ * Verhelst <wouter@debian.org>
+ * Version 2.2 - Auto switch to read-only mode (usefull for floppies).
+ * Version 2.3 - Fixed code so that Large File Support works. This
+ * removes the FS_32BIT compile-time directive; define
+ * _FILE_OFFSET_BITS=64 and _LARGEFILE_SOURCE if you used to be
+ * using FS_32BIT. This will allow you to use files >2GB instead of
+ * having to use the -m option. Wouter Verhelst <wouter@debian.org>
+ * Version 2.4 - Added code to keep track of children, so that we can
+ * properly kill them from initscripts. Add a call to daemon(),
+ * so that processes don't think they have to wait for us, which is
+ * interesting for initscripts as well. Wouter Verhelst
+ * <wouter@debian.org>
+ * Version 2.5 - Bugfix release: forgot to reset child_arraysize to
+ * zero after fork()ing, resulting in nbd-server going berserk
+ * when it receives a signal with at least one child open. Wouter
+ * Verhelst <wouter@debian.org>
+ * 10/10/2003 - Added socket option SO_KEEPALIVE (sf.net bug 819235);
+ * rectified type of mainloop::size_host (sf.net bugs 814435 and
+ * 817385); close the PID file after writing to it, so that the
+ * daemon can actually be found. Wouter Verhelst
+ * <wouter@debian.org>
+ * 10/10/2003 - Size of the data "size_host" was wrong and so was not
+ * correctly put in network endianness. Many types were corrected
+ * (size_t and off_t instead of int). <vspaceg@sourceforge.net>
+ * Version 2.6 - Some code cleanup.
+ * Version 2.7 - Better build system (not released (yet?)).
+ * 11/02/2004 - Doxygenified the source, modularized it a bit. Needs a
+ * lot more work, but this is a start. Wouter Verhelst
+ * <wouter@debian.org>
*/
-#define VERSION "1.5"
-#define GIGA (1*1024*1024*1024)
+/* Includes LFS defines, which defines behaviours of some of the following
+ * headers, so must come before those */
+#include "config.h"
+#include "lfs.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
+#include <sys/wait.h> /* wait */
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+#include <sys/param.h>
+#ifdef HAVE_SYS_MOUNT_H
+#include <sys/mount.h> /* For BLKGETSIZE */
+#endif
+#include <signal.h> /* sigaction */
#include <netinet/tcp.h>
#include <netinet/in.h> /* sockaddr_in, htons, in_addr */
#include <netdb.h> /* hostent, gethostby*, getservby* */
#include <fcntl.h>
#include <arpa/inet.h>
#include <strings.h>
+#include <dirent.h>
-#define _IO(a,b)
-// #define ISSERVER
-#define MY_NAME "nbd_server"
-
-/* Authorization file should contain lines with IP addresses of
- clients authorized to use the server. If it does not exist,
- access is permitted. */
-#define AUTH_FILE "nbd_server.allow"
+#include <glib.h>
+/* used in cliserv.h, so must come first */
+#define MY_NAME "nbd_server"
#include "cliserv.h"
-#undef _IO
-/* Deep magic: ioctl.h defines _IO macro (at least on linux) */
+/** how much space for child PIDs we have by default. Dynamically
+ allocated, and will be realloc()ed if out of space, so this should
+ probably be fair for most situations. */
+#define DEFAULT_CHILD_ARRAY 256
-/* Debugging macros, now nothing goes to syslog unless you say ISSERVER */
+/** Logging macros, now nothing goes to syslog unless you say ISSERVER */
#ifdef ISSERVER
-#define msg2(a,b) syslog(a,b)
-#define msg3(a,b,c) syslog(a,b,c)
-#define msg4(a,b,c,d) syslog(a,b,c,d)
+#define msg2(a,b) syslog(a,"%s", b)
+#define msg3(a,b,c) syslog(a,"%s %s", b,c)
+#define msg4(a,b,c,d) syslog(a,"%s %s %s", b,c,d)
#else
-#define msg2(a,b) do { fprintf(stderr,b) ; fputs("\n",stderr) ; } while(0)
-#define msg3(a,b,c) do { fprintf(stderr,b,c); fputs("\n",stderr) ; } while(0)
-#define msg4(a,b,c,d) do { fprintf(stderr,b,c,d); fputs("\n",stderr) ; } while(0)
+#define msg2(a,b) do { fprintf(stderr,"%s\n", b) ; } while(0)
+#define msg3(a,b,c) do { fprintf(stderr,"%s %s\n", b,c); } while(0)
+#define msg4(a,b,c,d) do { fprintf(stderr,"%s %s %s\n", b,c,d); } while(0)
#endif
-
-#include <sys/ioctl.h>
-#include <sys/mount.h> /* For BLKGETSIZE */
-
-#ifdef FS_32BIT
-typedef u32 fsoffset_t;
-#define htonll htonl
-#define ntohll ntohl
-#else
-typedef u64 fsoffset_t;
-#endif
-
-
+/* Debugging macros */
//#define DODBG
#ifdef DODBG
#define DEBUG( a ) printf( a )
#define DEBUG2( a,b )
#define DEBUG3( a,b,c )
#endif
-
-#if defined(HAVE_LLSEEK) && !defined(sun)
-/* Solaris already has llseek defined in unistd.h */
-extern long long llseek(unsigned int, long long, unsigned int);
+#ifndef PACKAGE_VERSION
+#define PACKAGE_VERSION ""
#endif
-
-void serveconnection(int net) ;
-void set_peername(int net,char *clientname) ;
-
-#define LINELEN 256
-char difffilename[256] ;
-
+/**
+ * The highest value a variable of type off_t can reach.
+ **/
+/* This is starting to get ugly. If someone knows a better way to find
+ * the maximum value of a signed type *without* relying on overflow
+ * (doing so breaks on 64bit architectures), that would be nice.
+ */
+#define OFFT_MAX (((((off_t)1)<<((sizeof(off_t)-1)*8))-1)<<7)+127
+#define LINELEN 256 /**< Size of static buffer used to read the
+ authorization file (yuck) */
+#define BUFSIZE (1024*1024) /**< Size of buffer that can hold requests */
+#define GIGA (1*1024*1024*1024) /**< 1 Gigabyte. Used as hunksize when doing
+ the multiple file thingy */
+#define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
+#define F_READONLY 1 /**< flag to tell us a file is readonly */
+#define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
+#define F_COPYONWRITE 4 /**< flag to tell us a file is exported using copyonwrite */
+char difffilename[1024]; /**< filename of the copy-on-write file. Doesn't belong here! */
+unsigned int timeout = 0; /**< disconnect timeout */
+int autoreadonly = 0; /**< 1 = switch to readonly if opening readwrite isn't
+ possible */
+char *auth_file="nbd_server.allow"; /**< authorization file */
+char exportname2[1024]; /**< File I'm exporting, with virtualhost resolved */
+off_t lastpoint = (off_t)-1; /**< keep track of where we are in the file, to
+ avoid an lseek if possible */
+char pagebuf[DIFFPAGESIZE]; /**< when doing copyonwrite, this is
+ used as a temporary buffer to store
+ the exported block in. @todo this is
+ a great example of namespace
+ pollution. Throw it out. */
+unsigned int port; /**< Port I'm listening at */
+char *exportname; /**< File I'm exporting */
+off_t exportsize = OFFT_MAX; /**< length of file I'm exporting */
+off_t hunksize = OFFT_MAX; /**< size of each exported file in case of -m */
+int flags = 0; /**< flags associated with this exported file */
+int export[1024];/**< array of filedescriptors of exported files; only first is
+ used unless -m option is activated */
+int difffile=-1; /**< filedescriptor for copyonwrite file */
+u32 difffilelen=0 ; /**< number of pages in difffile */
+u32 *difmap=NULL ; /**< Determine whether a block is in the original file
+ (difmap[block]==-1) or in the copyonwrite file (in which
+ case it contains the offset where it is to be found in the
+ copyonwrite file). @todo the kernel knows about sparse
+ files, we should use those instead. Should also be off_t
+ instead of u32; copyonwrite is probably broken wrt LFS */
+char clientname[256] ;
+int child_arraysize=DEFAULT_CHILD_ARRAY; /**< number of available slots for
+ child array */
+pid_t *children; /**< child array */
+char pidfname[256]; /**< name of our PID file */
+
+/**
+ * Variables associated with a copyonwrite server. Not yet used.
+ **/
+typedef struct {
+ char* difffilename; /**< filename of the copy-on-write file */
+ int difffile; /**< filedescriptor of copyonwrite file. @todo
+ shouldn't this be an array too? (cfr
+ nbd_server_opts::export) Or make -m and -c
+ mutually exclusive */
+ u32 difffilelen; /**< number of pages in difffile */
+ u32 *difmap; /**< see comment on the global difmap for this one */
+} cow_opts;
+
+/**
+ * Variables associated with a server. Not yet used. @todo modify the code to
+ * use an instance of this struct instead of the heap of global variables.
+ **/
+typedef struct {
+ char* exportname; /**< filename of the file we're exporting */
+ unsigned int port; /**< port we're exporting this file at */
+ char* authname; /**< filename of the authorization file */
+ off_t exportsize; /**< size of the file we're exporting */
+ off_t hunksize; /**< size of a hunk of an exported file */
+ int flags; /**< flags associated with this exported file */
+ char* clientname; /**< peer */
+ unsigned int timeout;/**< how long a connection may be idle
+ (0=forever) */
+ int export[1024]; /**< array of filedescriptors of exported files;
+ only the first is actually used unless we're
+ doing the multiple file option */
+ cow_opts* cow; /**< only used if (flags | F_COPYONWRITE) (NULL
+ otherwise) */
+} nbd_server_opts;
+
+/**
+ * Check whether a client is allowed to connect. Works with an authorization
+ * file which contains one line per machine, no wildcards.
+ *
+ * @param name IP address of client trying to connect (in human-readable form)
+ * @return 0 - authorization refused, 1 - OK
+ **/
int authorized_client(char *name)
-/* 0 - authorization refused, 1 - OK
- authorization file contains one line per machine, no wildcards
-*/
-{ FILE *f ;
+{
+ FILE *f ;
- char line[LINELEN] ;
+ char line[LINELEN] ;
- if ((f=fopen(AUTH_FILE,"r"))==NULL)
- { msg4(LOG_INFO,"Can't open authorization file %s (%s).",
- AUTH_FILE,strerror(errno)) ;
- return 1 ;
- }
+ if ((f=fopen(auth_file,"r"))==NULL) {
+ msg4(LOG_INFO,"Can't open authorization file %s (%s).",
+ auth_file,strerror(errno)) ;
+ return 1 ;
+ }
- while (fgets(line,LINELEN,f)!=NULL) {
- if (strncmp(line,name,strlen(name))==0) { fclose(f) ; return 1 ; }
- }
- fclose(f) ;
- return 0 ;
+ while (fgets(line,LINELEN,f)!=NULL) {
+ if (strncmp(line,name,strlen(name))==0) {
+ fclose(f);
+ return 1;
+ }
+ }
+ fclose(f) ;
+ return 0 ;
}
-
-inline void readit(int f, void *buf, int len)
+/**
+ * Read data from a file descriptor into a buffer
+ *
+ * @param f a file descriptor
+ * @param buf a buffer
+ * @param len the number of bytes to be read
+ **/
+inline void readit(int f, void *buf, size_t len)
{
- int res;
+ ssize_t res;
while (len > 0) {
DEBUG("*");
if ((res = read(f, buf, len)) <= 0)
}
}
-inline void writeit(int f, void *buf, int len)
+/**
+ * Write data from a buffer into a filedescriptor
+ *
+ * @param f a file descriptor
+ * @param buf a buffer containing data
+ * @param len the number of bytes to be written
+ **/
+inline void writeit(int f, void *buf, size_t len)
{
- int res;
+ ssize_t res;
while (len > 0) {
DEBUG("+");
if ((res = write(f, buf, len)) <= 0)
- err("Write failed: %m");
+ err("Send failed: %m");
len -= res;
buf += res;
}
}
-int port; /* Port I'm listening at */
-char *exportname; /* File I'm exporting */
-fsoffset_t exportsize = ~0, hunksize = ~0; /* ...and its length */
-int flags = 0;
-int export[1024];
-int difffile=-1 ;
-u32 difffilelen=0 ; /* number of pages in difffile */
-u32 *difmap=NULL ;
-char clientname[256] ;
-
-
-#define DIFFPAGESIZE 4096 /* diff file uses those chunks */
-
-#define F_READONLY 1
-#define F_MULTIFILE 2
-#define F_COPYONWRITE 4
-
+/**
+ * Parse the command line.
+ *
+ * @todo getopt() is a great thing, and easy to use. Also, we want to
+ * create a configuration file which nbd-server will read. Maybe do (as in,
+ * parse) that here.
+ *
+ * @param argc the argc argument to main()
+ * @param argv the argv argument to main()
+ **/
void cmdline(int argc, char *argv[])
{
int i;
if (argc < 3) {
printf("This is nbd-server version " VERSION "\n");
- printf("Usage: port file_to_export [size][kKmM] [-r] [-m] [-c]\n"
+ printf("Usage: port file_to_export [size][kKmM] [-r] [-m] [-c] [-a timeout_sec]\n"
" -r read only\n"
" -m multiple file\n"
" -c copy on write\n"
+ " -l file with list of hosts that are allowed to connect.\n"
+ " -a maximum idle seconds, terminates when idle time exceeded\n"
" if port is set to 0, stdin is used (for running from inetd)\n"
" if file_to_export contains '%%s', it is substituted with IP\n"
" address of machine trying to connect\n" );
flags |= F_MULTIFILE;
hunksize = 1*GIGA;
break;
- case 'c': flags |=F_COPYONWRITE ;
- break ;
+ case 'c': flags |=F_COPYONWRITE;
+ break;
+ case 'l':
+ free(auth_file);
+ if (i+1<argc) {
+ auth_file=argv[++i];
+ } else {
+ fprintf(stderr, "host list file requires an argument");
+ }
+ break;
+ case 'a':
+ if (i+1<argc) {
+ timeout = atoi(argv[i+1]);
+ i++;
+ } else {
+ fprintf(stderr, "timeout requires argument\n");
+ exit(1);
+ }
}
} else {
- fsoffset_t es;
- int last = strlen(argv[i])-1;
+ off_t es;
+ size_t last = strlen(argv[i])-1;
char suffix = argv[i][last];
if (suffix == 'k' || suffix == 'K' ||
suffix == 'm' || suffix == 'M')
argv[i][last] = '\0';
- es = (fsoffset_t)atol(argv[i]);
+ es = (off_t)atol(argv[i]);
switch (suffix) {
case 'm':
case 'M': es <<= 10;
exportname = argv[2];
}
-void connectme(int port)
+/**
+ * Signal handler for SIGCHLD
+ * @param s the signal we're handling (must be SIGCHLD, or something
+ * is severely wrong)
+ **/
+void sigchld_handler(int s)
{
- struct sockaddr_in addrin;
- int addrinlen = sizeof(addrin);
- int net, sock, newpid;
-#ifndef sun
- int yes=1;
-#else
- char yes='1';
-#endif
+ int* status=NULL;
+ int i;
+ char buf[80];
+ pid_t pid;
+
+ while((pid=wait(status)) > 0) {
+ if(WIFEXITED(status)) {
+ memset(buf,'\0', 80);
+ snprintf(buf, 79, "%d", WEXITSTATUS(status));
+ msg3(LOG_INFO, "Child exited with ", buf);
+ }
+ for(i=0;children[i]!=pid&&i<child_arraysize;i++);
+ if(i>=child_arraysize) {
+ memset(buf, '\0', 80);
+ snprintf(buf, 79, "%ld", (long)pid);
+ msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID ", buf);
+ } else {
+ children[i]=(pid_t)0;
+ DEBUG2("Removing %d from the list of children", pid);
+ }
+ }
+}
- if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
- err("socket: %m");
+/**
+ * Handle SIGTERM and dispatch it to our children
+ * @param s the signal we're handling (must be SIGTERM, or something
+ * is severely wrong).
+ **/
+void sigterm_handler(int s) {
+ int i;
+ int parent=0;
- /* lose the pesky "Address already in use" error message */
- if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
- err("setsockopt");
+ for(i=0;i<child_arraysize;i++) {
+ if(children[i]) {
+ kill(children[i], s);
+ parent=1;
+ }
}
- DEBUG("Waiting for connections... bind, ");
- addrin.sin_family = AF_INET;
- addrin.sin_port = htons(port);
- addrin.sin_addr.s_addr = 0;
- if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
- err("bind: %m");
- DEBUG("listen, ");
- if (listen(sock, 1) < 0)
- err("listen: %m");
- DEBUG("accept, ");
- for(;;) { /* infinite loop */
- if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
- err("accept: %m");
-
- set_peername(net,clientname) ;
- if (!authorized_client(clientname)) {
- msg2(LOG_INFO,"Unauthorized client") ;
- close(net) ;
- continue ;
- }
- msg2(LOG_INFO,"Authorized client") ;
- if ((newpid=fork())<0) {
- msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
- close(net) ;
- continue ;
- }
- if (newpid>0) { /* parent */
- close(net) ; continue ; }
- /* child */
- close(sock) ;
- msg2(LOG_INFO,"Starting to serve") ;
- serveconnection(net) ;
+ if(parent) {
+ unlink(pidfname);
}
+
+ exit(0);
}
-#define SEND writeit( net, &reply, sizeof( reply ));
-#define ERROR { reply.error = htonl(-1); SEND; reply.error = 0; lastpoint = -1; }
+/**
+ * Detect the size of a file.
+ *
+ * @param export An open filedescriptor
+ * @return the size of the file, or OFFT_MAX if detection was
+ * impossible.
+ **/
+off_t size_autodetect(int export)
+{
+ off_t es;
+ u32 es32;
+ struct stat stat_buf;
+ int error;
-fsoffset_t lastpoint = -1;
+#ifdef HAVE_SYS_MOUNT_H
+#ifdef HAVE_SYS_IOCTL_H
+#ifdef BLKGETSIZE
+ DEBUG("looking for export size with ioctl BLKGETSIZE\n");
+ if (!ioctl(export, BLKGETSIZE, &es32) && es32) {
+ es = (off_t)es32 * (off_t)512;
+ return es;
+ }
+#endif /* BLKGETSIZE */
+#endif /* HAVE_SYS_IOCTL_H */
+#endif /* HAVE_SYS_MOUNT_H */
+
+ DEBUG("looking for export size with fstat\n");
+ stat_buf.st_size = 0;
+ error = fstat(export, &stat_buf);
+ if (!error && stat_buf.st_size > 0) {
+ return (off_t)stat_buf.st_size;
+ } else {
+ err("fstat failed: %m");
+ }
-void maybeseek(int handle, fsoffset_t a)
-{
- if (a > exportsize)
+ DEBUG("looking for export size with lseek SEEK_END\n");
+ es = lseek(export, (off_t)0, SEEK_END);
+ if (es > ((off_t)0)) {
+ return es;
+ } else {
+ DEBUG2("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
+ }
+
+ err("Could not find size of exported block device: %m");
+ return OFFT_MAX;
+}
+
+/**
+ * Seek to a position in a file, unless we're already there.
+ * @param handle a filedescriptor
+ * @param a position to seek to
+ **/
+void maybeseek(int handle, off_t a) {
+ if (a < 0 || a > exportsize) {
err("Can not happen\n");
+ }
if (lastpoint != a) {
-#if defined(HAVE_LLSEEK) && !defined(FS_32BIT)
- if (llseek(handle, a, SEEK_SET) < 0)
-#else
- if (lseek(handle, (long)a, SEEK_SET) < 0)
-#endif
+ if (lseek(handle, a, SEEK_SET) < 0) {
err("Can not seek locally!\n");
+ }
lastpoint = a;
} else {
- DEBUG("@");
+ DEBUG("S");
}
}
-void myseek(int handle,fsoffset_t a)
+/**
+ * Write an amount of bytes at a given offset to the right file. This
+ * abstracts the write-side of the multiple file option.
+ *
+ * @param a The offset where the write should start
+ * @param buf The buffer to write from
+ * @param len The length of buf
+ * @return The number of bytes actually written, or -1 in case of an error
+ **/
+int rawexpwrite(off_t a, char *buf, size_t len)
{
-#if HAVE_LLSEEK && !defined(FS_32BIT)
- if (llseek(handle, a, SEEK_SET) < 0)
-#else
- if (lseek(handle, (long)a, SEEK_SET) < 0)
-#endif
- err("Can not seek locally!\n");
-}
-
-char pagebuf[DIFFPAGESIZE] ;
-
+ ssize_t res;
-int rawexpread(fsoffset_t a, char *buf, int len)
-{
- maybeseek(export[a/hunksize], a%hunksize);
- return (read(export[a/hunksize], buf, len) != len);
+ maybeseek(export[a/hunksize], a%hunksize);
+ res = write(export[a/hunksize], buf, len);
+ return (res < 0 || (size_t)res != len);
}
-int expread(fsoffset_t a, char *buf, int len)
-{ int rdlen ; fsoffset_t mapcnt,mapl,maph ;
- fsoffset_t pagestart; int offset ;
-
- if (flags & F_COPYONWRITE) {
- DEBUG3("Asked to read %d bytes at %lu.\n",len,(unsigned long)a) ;
-
- mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
-
- for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
- pagestart=mapcnt*DIFFPAGESIZE ;
- offset=a-pagestart ;
- rdlen=(len<DIFFPAGESIZE-offset) ? len : DIFFPAGESIZE-offset ;
- if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
- DEBUG3("Page %d is at %ld\n",(int)mapcnt,(long int)difmap[mapcnt]) ;
- myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
- if (read(difffile, buf, rdlen) != rdlen) return -1 ;
- } else { /* the block is not there */
- DEBUG2("Page %d is not here, we read the original one\n",
- (int)mapcnt) ;
- if (rawexpread(a,buf,rdlen)) return -1 ;
- }
- len-=rdlen ; a+=rdlen ; buf+=rdlen ;
- }
- } else return rawexpread(a,buf,len) ;
- return 0 ;
+/**
+ * seek to a position in a file, no matter what. Used when using maybeseek is a
+ * bad idea (for instance, because we're reading the copyonwrite file instead
+ * of the exported file).
+ * @param handle a filedescriptor
+ * @param a position to seek to
+ * @todo get rid of this; lastpoint is a global variable right now, but it
+ * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
+ * easier.
+ **/
+void myseek(int handle,off_t a) {
+ if (lseek(handle, a, SEEK_SET) < 0) {
+ err("Can not seek locally!\n");
+ }
}
-int rawexpwrite(fsoffset_t a, char *buf, int len)
+/**
+ * Read an amount of bytes at a given offset from the right file. This
+ * abstracts the read-side of the multiple files option.
+ *
+ * @param a The offset where the read should start
+ * @param buf A buffer to read into
+ * @param len The size of buf
+ * @return The number of bytes actually read, or -1 in case of an
+ * error.
+ **/
+int rawexpread(off_t a, char *buf, size_t len)
{
+ ssize_t res;
+
maybeseek(export[a/hunksize], a%hunksize);
- return (write(export[a/hunksize], buf, len) != len);
+ res = read(export[a/hunksize], buf, len);
+ return (res < 0 || (size_t)res != len);
}
-
-int expwrite(fsoffset_t a, char *buf, int len)
-{ u32 mapcnt,mapl,maph ; int wrlen,rdlen ;
- fsoffset_t pagestart ; int offset ;
-
- if (flags & F_COPYONWRITE) {
- DEBUG3("Asked to write %d bytes at %lu.\n",len,(unsigned long)a) ;
-
- mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
-
- for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
- pagestart=mapcnt*DIFFPAGESIZE ;
- offset=a-pagestart ;
- wrlen=(len<DIFFPAGESIZE-offset) ? len : DIFFPAGESIZE-offset ;
-
- if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
- DEBUG3("Page %d is at %ld\n",mapcnt,(long)difmap[mapcnt]) ;
- myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
- if (write(difffile, buf, wrlen) != wrlen) return -1 ;
- } else { /* the block is not there */
- myseek(difffile,difffilelen*DIFFPAGESIZE) ;
- difmap[mapcnt]=difffilelen++ ;
- DEBUG3("Page %d is not here, we put it at %ld\n",
- mapcnt,(long)difmap[mapcnt]) ;
-
- rdlen=DIFFPAGESIZE ;
- if (rdlen+pagestart%hunksize>hunksize)
- rdlen=hunksize-(pagestart%hunksize) ;
- if (rawexpread(pagestart,pagebuf,rdlen)) return -1 ;
- memcpy(pagebuf+offset,buf,wrlen) ;
- if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
- }
- len-=wrlen ; a+=wrlen ; buf+=wrlen ;
- }
- } else return(rawexpwrite(a,buf,len));
- return 0 ;
+/**
+ * Read an amount of bytes at a given offset from the right file. This
+ * abstracts the read-side of the copyonwrite stuff, and calls
+ * rawexpread() with the right parameters to do the actual work.
+ * @param a The offset where the read should start
+ * @param buf A buffer to read into
+ * @param len The size of buf
+ * @return The number of bytes actually read, or -1 in case of an error
+ **/
+int expread(off_t a, char *buf, size_t len)
+{
+ off_t rdlen, offset;
+ off_t mapcnt, mapl, maph, pagestart;
+
+ if (!(flags & F_COPYONWRITE))
+ return rawexpread(a, buf, len);
+ DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
+
+ mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
+
+ for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
+ pagestart=mapcnt*DIFFPAGESIZE;
+ offset=a-pagestart;
+ rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
+ len : (size_t)DIFFPAGESIZE-offset;
+ if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
+ DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
+ (unsigned long)difmap[mapcnt]);
+ myseek(difffile, difmap[mapcnt]*DIFFPAGESIZE+offset);
+ if (read(difffile, buf, rdlen) != rdlen) return -1;
+ } else { /* the block is not there */
+ DEBUG2("Page %Lu is not here, we read the original one\n",
+ (unsigned long long)mapcnt);
+ return rawexpread(a, buf, rdlen);
+ }
+ len-=rdlen; a+=rdlen; buf+=rdlen;
+ }
+ return 0;
}
-int mainloop(int net)
+/**
+ * Write an amount of bytes at a given offset to the right file. This
+ * abstracts the write-side of the copyonwrite option, and calls
+ * rawexpwrite() with the right parameters to do the actual work.
+ *
+ * @param a The offset where the write should start
+ * @param buf The buffer to write from
+ * @param len The length of buf
+ * @return The number of bytes actually written, or -1 in case of an error
+ **/
+int expwrite(off_t a, char *buf, size_t len)
{
- struct nbd_request request;
- struct nbd_reply reply;
+ off_t mapcnt,mapl,maph ;
+ off_t wrlen,rdlen ;
+ off_t pagestart ;
+ off_t offset ;
+
+ if (!(flags & F_COPYONWRITE))
+ return(rawexpwrite(a,buf,len));
+ DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
+
+ mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
+
+ for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
+ pagestart=mapcnt*DIFFPAGESIZE ;
+ offset=a-pagestart ;
+ wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
+ len : (size_t)DIFFPAGESIZE-offset;
+
+ if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
+ DEBUG3("Page %Lu is at %lu\n", (unsigned long long)mapcnt,
+ (unsigned long)difmap[mapcnt]) ;
+ myseek(difffile,difmap[mapcnt]*DIFFPAGESIZE+offset) ;
+ if (write(difffile, buf, wrlen) != wrlen) return -1 ;
+ } else { /* the block is not there */
+ myseek(difffile,difffilelen*DIFFPAGESIZE) ;
+ difmap[mapcnt]=difffilelen++ ;
+ DEBUG3("Page %Lu is not here, we put it at %lu\n",
+ (unsigned long long)mapcnt,
+ (unsigned long)difmap[mapcnt]);
+ rdlen=DIFFPAGESIZE ;
+ if (rdlen+pagestart%hunksize>hunksize)
+ rdlen=hunksize-(pagestart%hunksize) ;
+ if (rawexpread(pagestart,pagebuf,rdlen)) return -1 ;
+ memcpy(pagebuf+offset,buf,wrlen) ;
+ if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
+ }
+ len-=wrlen ; a+=wrlen ; buf+=wrlen ;
+ }
+ return 0;
+}
+
+/**
+ * Do the initial negotiation.
+ *
+ * @param net A socket to do the negotiation over
+ **/
+void negotiate(int net) {
char zeros[300];
- int i = 0;
- fsoffset_t size_host;
+ u64 size_host;
memset(zeros, 0, 290);
if (write(net, INIT_PASSWD, 8) < 0)
err("Negotiation failed: %m");
-#ifndef FS_32BIT
cliserv_magic = htonll(cliserv_magic);
-#endif
if (write(net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
err("Negotiation failed: %m");
- size_host = htonll(exportsize);
-#ifdef FS_32BIT
- if (write(net, zeros, 4) < 0 || write(net, &size_host, 4) < 0)
-#else
+ size_host = htonll((u64)exportsize);
if (write(net, &size_host, 8) < 0)
-#endif
err("Negotiation failed: %m");
if (write(net, zeros, 128) < 0)
err("Negotiation failed: %m");
+}
+/** sending macro; not really required. Uses variables in the local
+ * scope of mainloop(). Get rid of it. */
+#define SEND writeit( net, &reply, sizeof( reply ));
+/** error macro; not sure whether we really need this. Uses variables
+ * in the local scope of mainloop(). Get rid of this beast. */
+#define ERROR { reply.error = htonl(-1); SEND; reply.error = 0; lastpoint = -1; }
+/**
+ * Serve a file to a single client.
+ *
+ * @todo This beast needs to be split up in many tiny little manageable
+ * pieces. Preferably with a chainsaw.
+ *
+ * @param net A network socket, connected to an nbd client
+ * @return never
+ **/
+int mainloop(int net)
+{
+ struct nbd_request request;
+ struct nbd_reply reply;
+#ifdef DODBG
+ int i = 0;
+#endif
+ negotiate(net);
DEBUG("Entering request loop!\n");
reply.magic = htonl(NBD_REPLY_MAGIC);
reply.error = 0;
while (1) {
-#define BUFSIZE (1024*1024)
char buf[BUFSIZE];
- int len;
-
+ size_t len;
#ifdef DODBG
i++;
printf("%d: ", i);
#endif
-
+ if (timeout)
+ alarm(timeout);
readit(net, &request, sizeof(request));
request.from = ntohll(request.from);
request.type = ntohl(request.type);
- if (request.type==2) { /* Disconnect request */
+ if (request.type==NBD_CMD_DISC) { /* Disconnect request */
if (difmap) free(difmap) ;
if (difffile>=0) {
close(difffile) ; unlink(difffilename) ; }
if (len > BUFSIZE)
err("Request too big!");
#ifdef DODBG
- printf("%s from %d (%d) len %d, ", (request.type ? "WRITE" : "READ"),
- (int) request.from, (int) request.from / 512, len);
+ printf("%s from %Lu (%Lu) len %d, ", request.type ? "WRITE" :
+ "READ", (unsigned long long)request.from,
+ (unsigned long long)request.from / 512, len);
#endif
memcpy(reply.handle, request.handle, sizeof(reply.handle));
- if (((request.from + len) > exportsize) ||
+ if ((request.from + len) > (OFFT_MAX)) {
+ DEBUG("[Number too large!]");
+ ERROR;
+ continue;
+ }
+
+ if (((ssize_t)((off_t)request.from + len) > exportsize) ||
((flags & F_READONLY) && request.type)) {
DEBUG("[RANGE!]");
ERROR;
continue;
}
+
if (request.type==1) { /* WRITE */
DEBUG("wr: net->buf, ");
readit(net, buf, len);
DEBUG("buf->exp, ");
- if (expwrite(request.from, buf, len)) {
+ if ((autoreadonly == 1) || expwrite(request.from, buf, len)) {
DEBUG("Write failed: %m" );
ERROR;
continue;
}
lastpoint += len;
SEND;
+ DEBUG("OK!\n");
continue;
}
/* READ */
}
}
-char exportname2[1024];
+/**
+ * Split a single exportfile into multiple ones, if that was asked.
+ * @return 0 on success, -1 on failure
+ **/
+int splitexport(void) {
+ off_t i ;
+
+ for (i=0; i<exportsize; i+=hunksize) {
+ char exportname3[1024];
+
+ if(flags & F_MULTIFILE) {
+ snprintf(exportname3, 1024, "%s.%d", exportname2, (int)(i/hunksize));
+ } else {
+ strncpy(exportname3, exportname2, 1024);
+ }
+ exportname3[1023]='\0';
+ printf( "Opening %s\n", exportname3 );
+ if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) {
+ /* Read WRITE ACCESS was requested by media is only read only */
+ autoreadonly = 1;
+ flags |= F_READONLY;
+ if ((export[i/hunksize] = open(exportname3, O_RDONLY)) == -1)
+ err("Could not open exported file: %m");
+ }
+ }
+
+ if (flags & F_COPYONWRITE) {
+ snprintf(difffilename, 1024, "%s-%s-%d.diff",exportname2,clientname,
+ (int)getpid()) ;
+ difffilename[1023]='\0';
+ msg3(LOG_INFO,"About to create map and diff file %s",difffilename) ;
+ difffile=open(difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
+ if (difffile<0) err("Could not create diff file (%m)") ;
+ if ((difmap=calloc(exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
+ err("Could not allocate memory") ;
+ for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
+ }
+
+ return 0;
+}
+
+/**
+ * Serve a connection.
+ *
+ * @todo allow for multithreading, perhaps use libevent.
+ *
+ * @param net A network socket connected to an nbd client
+ **/
+void serveconnection(int net) {
+ char buf[80];
+ splitexport();
+ if (exportsize == OFFT_MAX) {
+ exportsize = size_autodetect(export[0]);
+ }
+ if (exportsize > OFFT_MAX) {
+ err("Size of exported file is too big\n");
+ }
+ else {
+ memset(buf, '\0', 80);
+ snprintf(buf, 79, "%Lu", (unsigned long long)exportsize);
+ msg3(LOG_INFO, "size of exported file/device is ", buf);
+ }
+
+ setmysockopt(net);
+ mainloop(net);
+}
+
+/**
+ * Find the name of the file we have to serve. This will use snprintf()
+ * to put the IP address of the client inside a filename containing
+ * "%s". That name is then written to exportname2
+ *
+ * @param net A socket connected to an nbd client
+ * @param clientname a buffer which must be at least 255+1 bytes long;
+ * the IP address (in human-readable format) will be copied in there.
+ **/
void set_peername(int net,char *clientname)
{
struct sockaddr_in addrin;
if (getpeername( net, (struct sockaddr *) &addrin, &addrinlen ) < 0)
err("getsockname failed: %m");
peername = inet_ntoa(addrin.sin_addr);
- sprintf(exportname2, exportname, peername);
+ snprintf(exportname2, 1024, exportname, peername);
+ exportname2[1023]='\0';
- msg4(LOG_INFO, "connect from %s, assigned file is %s", peername, exportname2);
+ msg4(LOG_INFO, "connect from %s, assigned file is %s",
+ peername, exportname2);
strncpy(clientname,peername,255) ;
}
-fsoffset_t size_autodetect(int export)
+/**
+ * Connect the socket, and start to serve. This function will fork()
+ * if a connection from an authorized client is received, and will
+ * start mainloop().
+ *
+ * @todo modularize this giant beast. Preferably with a chainsaw. Also,
+ * it has no business starting mainloop(); it should connect, and be
+ * done with it.
+ *
+ * @param port the port where we will listen
+ **/
+void connectme(unsigned int port)
{
- fsoffset_t es;
- DEBUG("looking for export size with lseek SEEK_END\n");
- if ((int)(es = lseek(export, 0, SEEK_END)) == -1 || es == 0) {
- struct stat stat_buf;
- int error;
- DEBUG("looking for export size with fstat\n");
- stat_buf.st_size = 0;
- if ((error = fstat(export, &stat_buf)) == -1 || stat_buf.st_size == 0 ) {
- DEBUG("looking for export size with ioctl BLKGETSIZE\n");
-#ifdef BLKGETSIZE
- if(ioctl(export, BLKGETSIZE, &es) || es == 0) {
+ struct sockaddr_in addrin;
+ struct sigaction sa;
+ int addrinlen = sizeof(addrin);
+ int net, sock, newpid, i;
+#ifndef sun
+ int yes=1;
#else
- if(1){
-#endif
- err("Could not find size of exported block device: %m");
+ char yes='1';
+#endif /* sun */
+#ifndef NODAEMON
+#ifndef NOFORK
+ FILE*pidf;
+
+ if(port) {
+ if(daemon(0,0)<0) {
+ err("daemon");
+ }
+ snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", port);
+ pidf=fopen(pidfname, "w");
+ if(pidf) {
+ fprintf(pidf,"%d", (int)getpid());
+ fclose(pidf);
+ } else {
+ perror("fopen");
+ fprintf(stderr, "Not fatal; continuing");
+ }
+ }
+#endif /* NOFORK */
+#endif /* NODAEMON */
+
+ if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
+ err("socket: %m");
+
+ /* lose the pesky "Address already in use" error message */
+ if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
+ err("setsockopt SO_REUSEADDR");
+ }
+ if (setsockopt(sock,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
+ err("setsockopt SO_KEEPALIVE");
+ }
+
+ DEBUG("Waiting for connections... bind, ");
+ addrin.sin_family = AF_INET;
+ addrin.sin_port = htons(port);
+ addrin.sin_addr.s_addr = 0;
+ if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
+ err("bind: %m");
+ DEBUG("listen, ");
+ if (listen(sock, 1) < 0)
+ err("listen: %m");
+ DEBUG("accept, ");
+ sa.sa_handler = sigchld_handler;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_RESTART;
+ if(sigaction(SIGCHLD, &sa, NULL) == -1)
+ err("sigaction: %m");
+ sa.sa_handler = sigterm_handler;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_RESTART;
+ if(sigaction(SIGTERM, &sa, NULL) == -1)
+ err("sigaction: %m");
+ children=malloc(sizeof(pid_t)*child_arraysize);
+ memset(children, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
+ for(;;) { /* infinite loop */
+ if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
+ err("accept: %m");
+
+ set_peername(net,clientname);
+ if (!authorized_client(clientname)) {
+ msg2(LOG_INFO,"Unauthorized client") ;
+ close(net) ;
+ continue ;
+ }
+ msg2(LOG_INFO,"Authorized client") ;
+ for(i=0;children[i]&&i<child_arraysize;i++);
+ if(i>=child_arraysize) {
+ pid_t*ptr;
+
+ ptr=realloc(children, sizeof(pid_t)*child_arraysize);
+ if(ptr) {
+ children=ptr;
+ memset(children+child_arraysize, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
+ i=child_arraysize+1;
+ child_arraysize+=DEFAULT_CHILD_ARRAY;
} else {
- es *= 512; /* assume blocksize 512 */
+ msg2(LOG_INFO,"Not enough memory to store child PID");
+ close(net);
+ continue;
}
- } else {
- es = stat_buf.st_size;
}
+#ifndef NOFORK
+ if ((children[i]=fork())<0) {
+ msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
+ close(net) ;
+ continue ;
+ }
+ if (children[i]>0) { /* parent */
+ close(net) ; continue ; }
+ /* child */
+ realloc(children,0);
+ child_arraysize=0;
+ close(sock) ;
+#endif // NOFORK
+ msg2(LOG_INFO,"Starting to serve") ;
+ serveconnection(net) ;
}
- return es;
}
+/**
+ * Main entry point...
+ **/
int main(int argc, char *argv[])
{
- int net;
- fsoffset_t i;
-
if (sizeof( struct nbd_request )!=28) {
fprintf(stderr,"Bad size of structure. Alignment problems?\n");
exit(-1) ;
return 0 ;
}
-
-void serveconnection(int net)
-{
- u64 i ;
-
- for (i=0; i<exportsize; i+=hunksize) {
- char exportname3[1024];
-
- sprintf(exportname3, exportname2, i/hunksize);
- printf( "Opening %s\n", exportname3 );
- if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1)
- err("Could not open exported file: %m");
- }
-
- if (exportsize == (u64)~0) {
- exportsize = size_autodetect(export[0]);
- }
- if (exportsize > (~0UL >> 1))
-#ifdef HAVE_LLSEEK
- if ((exportsize >> 10) > (~0UL >> 1))
- msg3(LOG_INFO, "size of exported file/device is %luMB",
- (unsigned long)(exportsize >> 20));
- else
- msg3(LOG_INFO, "size of exported file/device is %luKB",
- (unsigned long)(exportsize >> 10));
-#else
- err("Size of exported file is too big\n");
-#endif
- else
- msg3(LOG_INFO, "size of exported file/device is %lu",
- (unsigned long)exportsize);
-
- if (flags & F_COPYONWRITE) {
- sprintf(difffilename,"%s-%s-%d.diff",exportname2,clientname,
- (int)getpid()) ;
- msg3(LOG_INFO,"About to create map and diff file %s",difffilename) ;
- difffile=open(difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
- if (difffile<0) err("Could not create diff file (%m)") ;
- if ((difmap=calloc(exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
- err("Could not allocate memory") ;
- for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
- }
-
- setmysockopt(net);
-
- mainloop(net);
-}
projects / nbd.git / blobdiff