r82: Stop using global variables.
authoryoe <yoe>
Thu, 14 Oct 2004 18:12:09 +0000 (18:12 +0000)
committeryoe <yoe>
Thu, 14 Oct 2004 18:12:09 +0000 (18:12 +0000)
UNTESTED CODE. DO NOT USE THIS. Instead, use a file release, or code from the
release_2_7 branch.

Of course, if you want to help me fix bugs, that's always welcome... ;-)

nbd-server.c

index 0bff357..2566800 100644 (file)
@@ -45,7 +45,7 @@
  *     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?)).
+ * Version 2.7 - Better build system.
  * 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>
@@ -80,6 +80,8 @@
 #include <arpa/inet.h>
 #include <strings.h>
 #include <dirent.h>
+#include <unistd.h>
+#include <getopt.h>
 
 #include <glib.h>
 
 #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,"%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)
+#define msg2(a,b) g_message(a,b)
+#define msg3(a,b,c) g_message(a,b,c)
+#define msg4(a,b,c,d) g_message(a,b,c,d)
 #endif
 
 /* Debugging macros */
 /* 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.
+ *
+ * Actually, do we need this at all? Can't we just say '0 is autodetect', and
+ * live with it? Or better yet, use an extra flag, or so?
  */
 #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
 #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 */
+#define F_AUTOREADONLY 8  /**< flag to tell us a file is set to autoreadonly */
+//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 */
@@ -169,38 +175,43 @@ pid_t *children; /**< child array */
 char pidfname[256]; /**< name of our PID file */
 
 /**
- * Variables associated with a copyonwrite server. Not yet used.
+ * Variables associated with a server.
  **/
 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;
+       char* exportname;    /**< (unprocessed) filename of the file we're exporting */
+       off_t hunksize;      /**< size of a hunk of an exported file */
+       off_t expected_size; /**< size of the exported file as it was told to
+                              us through configuration */
+       unsigned int port;   /**< port we're exporting this file at */
+       char* authname;      /**< filename of the authorization file */
+       int flags;           /**< flags associated with this exported file */
+       unsigned int timeout;/**< how long a connection may be idle
+                              (0=forever) */
+} SERVER;
 
 /**
- * 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.
+ * Variables associated with a client socket.
  **/
 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) */
+       char *clientname;    /**< peer */
+       char *exportname;    /**< (processed) filename of the file we're exporting */
        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;
+       int lastpoint;       /**< For keeping track of where we are in a file.
+                              This code is BUGGY currently, at least in
+                              combination with the multiple file option. */
+       int net;             /**< The actual client socket */
+       SERVER *server;      /**< The server this client is getting data from */
+       char* difffilename;  /**< filename of the copy-on-write file, if any */
+       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 */
+} CLIENT;
 
 /**
  * Check whether a client is allowed to connect. Works with an authorization
@@ -209,20 +220,19 @@ typedef struct {
  * @param name IP address of client trying to connect (in human-readable form)
  * @return 0 - authorization refused, 1 - OK
  **/
-int authorized_client(char *name)
-{
+int authorized_client(CLIENT *opts) {
        FILE *f ;
    
-       char line[LINELEN] ; 
+       char line[LINELEN]; 
 
-       if ((f=fopen(auth_file,"r"))==NULL) {
+       if ((f=fopen(opts->server->authname,"r"))==NULL) {
                msg4(LOG_INFO,"Can't open authorization file %s (%s).",
-                    auth_file,strerror(errno)) ;
+                    opts->server->authname,strerror(errno)) ;
                return 1 ; 
        }
   
        while (fgets(line,LINELEN,f)!=NULL) {
-               if (strncmp(line,name,strlen(name))==0) {
+               if (strncmp(line,opts->clientname,strlen(opts->clientname))==0) {
                        fclose(f);
                        return 1;
                }
@@ -270,6 +280,23 @@ inline void writeit(int f, void *buf, size_t len)
 }
 
 /**
+ * Print out a message about how to use nbd-server. Split out to a separate
+ * function so that we can call it from multiple places
+ */
+void usage() {
+       printf("This is nbd-server version " VERSION "\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" );
+}
+
+/**
  * Parse the command line.
  *
  * @todo getopt() is a great thing, and easy to use. Also, we want to
@@ -279,72 +306,74 @@ inline void writeit(int f, void *buf, size_t len)
  * @param argc the argc argument to main()
  * @param argv the argv argument to main()
  **/
-void cmdline(int argc, char *argv[])
-{
+SERVER* 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] [-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" );
+       int c;
+       struct option long_options[] = {
+               {"read-only", no_argument, NULL, 'r'},
+               {"multi-file", no_argument, NULL, 'm'},
+               {"copy-on-write", no_argument, NULL, 'c'},
+               {"authorize-file", required_argument, NULL, 'l'},
+               {"idle-time", required_argument, NULL, 'a'},
+               {0,0,0,0}
+       };
+       SERVER *serve;
+
+       serve=g_malloc(sizeof(SERVER));
+       while((c=getopt_long(argc, argv, "a:cl:mr", long_options, &i))>=0) {
+               switch (c) {
+               case 'r':
+                       serve->flags |= F_READONLY;
+                       break;
+               case 'm':
+                       serve->flags |= F_MULTIFILE;
+                       serve->hunksize = 1*GIGA;
+                       break;
+               case 'c': 
+                       serve->flags |=F_COPYONWRITE;
+                       break;
+               case 'l':
+                       serve->authname=optarg;
+                       break;
+               case 'a': 
+                       serve->timeout=strtol(optarg, NULL, 0);
+                       break;
+               default:
+                       usage();
+                       exit(0);
+                       break;
+               }
+       }
+       /* What's left: the port to export, the name of the to be exported
+        * file, and, optionally, the size of the file, in that order. */
+       if(++i>argc) {
+               usage();
+               exit(0);
+       } 
+       serve->port=strtol(argv[i], NULL, 0);
+       if(++i>argc) {
+               usage();
                exit(0);
        }
-       port = atoi(argv[1]);
-       for (i = 3; i < argc; i++) {
-               if (*argv[i] == '-') {
-                       switch (argv[i][1]) {
-                       case 'r':
-                               flags |= F_READONLY;
-                               break;
+       serve->exportname = argv[i];
+       if(++i<=argc) {
+               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 = (off_t)atol(argv[i]);
+               switch (suffix) {
                        case 'm':
-                               flags |= F_MULTIFILE;
-                               hunksize = 1*GIGA;
-                               break;
-                       case 'c': flags |=F_COPYONWRITE;
-                               break;
-                       case 'l':
-                               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 {
-                       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 = (off_t)atol(argv[i]);
-                       switch (suffix) {
-                               case 'm':
-                               case 'M':  es <<= 10;
-                               case 'k':
-                               case 'K':  es <<= 10;
-                               default :  break;
-                       }
-                       exportsize = es;
+                       case 'M':  es <<= 10;
+                       case 'k':
+                       case 'K':  es <<= 10;
+                       default :  break;
                }
+               serve->expected_size = es;
        }
-
-       exportname = argv[2];
+       return serve;
 }
 
 /**
@@ -451,16 +480,17 @@ off_t size_autodetect(int export)
  * Seek to a position in a file, unless we're already there.
  * @param handle a filedescriptor
  * @param a position to seek to
+ * @param client the client we're working for
  **/
-void maybeseek(int handle, off_t a) {
-       if (a < 0 || a > exportsize) {
+void maybeseek(int handle, off_t a, CLIENT* client) {
+       if (a < 0 || a > client->exportsize) {
                err("Can not happen\n");
        }
-       if (lastpoint != a) {
+       if (client->lastpoint != a) {
                if (lseek(handle, a, SEEK_SET) < 0) {
                        err("Can not seek locally!\n");
                }
-               lastpoint = a;
+               client->lastpoint = a;
        } else {
                DEBUG("S");
        }
@@ -475,12 +505,13 @@ void maybeseek(int handle, off_t a) {
  * @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)
+int rawexpwrite(off_t a, char *buf, size_t len, CLIENT *client)
 {
        ssize_t res;
 
-       maybeseek(export[a/hunksize], a%hunksize);
-       res = write(export[a/hunksize], buf, len);
+       maybeseek(client->export[a/client->server->hunksize],
+                       a%client->server->hunksize, client);
+       res = write(client->export[a/client->server->hunksize], buf, len);
        return (res < 0 || (size_t)res != len);
 }
 
@@ -510,12 +541,13 @@ void myseek(int handle,off_t a) {
  * @return The number of bytes actually read, or -1 in case of an
  * error.
  **/
-int rawexpread(off_t a, char *buf, size_t len)
+int rawexpread(off_t a, char *buf, size_t len, CLIENT *client)
 {
        ssize_t res;
 
-       maybeseek(export[a/hunksize], a%hunksize);
-       res = read(export[a/hunksize], buf, len);
+       maybeseek(client->export[a/client->server->hunksize],
+                       a%client->server->hunksize, client);
+       res = read(client->export[a/client->server->hunksize], buf, len);
        return (res < 0 || (size_t)res != len);
 }
 
@@ -528,13 +560,13 @@ int rawexpread(off_t a, char *buf, size_t len)
  * @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)
+int expread(off_t a, char *buf, size_t len, CLIENT *client)
 {
        off_t rdlen, offset;
        off_t mapcnt, mapl, maph, pagestart;
  
-       if (!(flags & F_COPYONWRITE))
-               return rawexpread(a, buf, len);
+       if (!(client->server->flags & F_COPYONWRITE))
+               return rawexpread(a, buf, len, client);
        DEBUG3("Asked to read %d bytes at %Lu.\n", len, (unsigned long long)a);
 
        mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
@@ -544,15 +576,15 @@ int expread(off_t a, char *buf, size_t len)
                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 */
+               if (client->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;
+                       myseek(client->difffile, client->difmap[mapcnt]*DIFFPAGESIZE+offset);
+                       if (read(client->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);
+                       return rawexpread(a, buf, rdlen, client);
                }
                len-=rdlen; a+=rdlen; buf+=rdlen;
        }
@@ -569,15 +601,15 @@ int expread(off_t a, char *buf, size_t len)
  * @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)
-{
-       off_t mapcnt,mapl,maph ;
-       off_t wrlen,rdlen ; 
-       off_t pagestart ;
-       off_t offset ;
-
-       if (!(flags & F_COPYONWRITE))
-               return(rawexpwrite(a,buf,len)); 
+int expwrite(off_t a, char *buf, size_t len, CLIENT *client) {
+       char pagebuf[DIFFPAGESIZE];
+       off_t mapcnt,mapl,maph;
+       off_t wrlen,rdlen; 
+       off_t pagestart;
+       off_t offset;
+
+       if (!(client->server->flags & F_COPYONWRITE))
+               return(rawexpwrite(a,buf,len, client)); 
        DEBUG3("Asked to write %d bytes at %Lu.\n", len, (unsigned long long)a);
 
        mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
@@ -588,23 +620,29 @@ int expwrite(off_t a, char *buf, size_t len)
                wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
                        len : (size_t)DIFFPAGESIZE-offset;
 
-               if (difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
+               if (client->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 ;
+                       myseek(client->difffile,
+                                       client->difmap[mapcnt]*DIFFPAGESIZE+offset);
+                       if (write(client->difffile, buf, wrlen) != wrlen) return -1 ;
                } else { /* the block is not there */
-                       myseek(difffile,difffilelen*DIFFPAGESIZE) ;
-                       difmap[mapcnt]=difffilelen++ ;
+                       myseek(client->difffile,client->difffilelen*DIFFPAGESIZE) ;
+                       client->difmap[mapcnt]=client->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 ;
+                       if (rdlen+pagestart%(client->server->hunksize) >
+                                       (client->server->hunksize)) 
+                               rdlen=client->server->hunksize -
+                                       (pagestart%client->server->hunksize);
+                       if (rawexpread(pagestart, pagebuf, rdlen, client))
+                               return -1;
                        memcpy(pagebuf+offset,buf,wrlen) ;
-                       if (write(difffile,pagebuf,DIFFPAGESIZE)!=DIFFPAGESIZE) return -1 ;
+                       if (write(client->difffile, pagebuf, DIFFPAGESIZE) !=
+                                       DIFFPAGESIZE)
+                               return -1;
                }                                                   
                len-=wrlen ; a+=wrlen ; buf+=wrlen ;
        }
@@ -616,29 +654,27 @@ int expwrite(off_t a, char *buf, size_t len)
  *
  * @param net A socket to do the negotiation over
  **/
-void negotiate(int net) {
+void negotiate(CLIENT *client) {
        char zeros[300];
        u64 size_host;
 
        memset(zeros, 0, 290);
-       if (write(net, INIT_PASSWD, 8) < 0)
+       if (write(client->net, INIT_PASSWD, 8) < 0)
                err("Negotiation failed: %m");
        cliserv_magic = htonll(cliserv_magic);
-       if (write(net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
+       if (write(client->net, &cliserv_magic, sizeof(cliserv_magic)) < 0)
                err("Negotiation failed: %m");
-       size_host = htonll((u64)exportsize);
-       if (write(net, &size_host, 8) < 0)
+       size_host = htonll((u64)(client->exportsize));
+       if (write(client->net, &size_host, 8) < 0)
                err("Negotiation failed: %m");
-       if (write(net, zeros, 128) < 0)
+       if (write(client->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; }
+/** sending macro. */
+#define SEND(net,reply) writeit( net, &reply, sizeof( reply ));
+/** error macro. */
+#define ERROR(client,reply) { reply.error = htonl(-1); SEND(client->net,reply); reply.error = 0; client->lastpoint = -1; }
 /**
  * Serve a file to a single client.
  *
@@ -648,14 +684,14 @@ void negotiate(int net) {
  * @param net A network socket, connected to an nbd client
  * @return never
  **/
-int mainloop(int net)
+int mainloop(CLIENT *client)
 {
        struct nbd_request request;
        struct nbd_reply reply;
 #ifdef DODBG
        int i = 0;
 #endif
-       negotiate(net);
+       negotiate(client);
        DEBUG("Entering request loop!\n");
        reply.magic = htonl(NBD_REPLY_MAGIC);
        reply.error = 0;
@@ -666,16 +702,16 @@ int mainloop(int net)
                i++;
                printf("%d: ", i);
 #endif
-               if (timeout) 
-                       alarm(timeout);
-               readit(net, &request, sizeof(request));
+               if (client->server->timeout) 
+                       alarm(client->server->timeout);
+               readit(client->net, &request, sizeof(request));
                request.from = ntohll(request.from);
                request.type = ntohl(request.type);
 
                if (request.type==NBD_CMD_DISC) { /* Disconnect request */
-                 if (difmap) free(difmap) ;
-                  if (difffile>=0) { 
-                     close(difffile) ; unlink(difffilename) ; }
+                 if (client->difmap) free(client->difmap) ;
+                  if (client->difffile>=0) { 
+                     close(client->difffile) ; unlink(client->difffilename) ; }
                  err("Disconnect request received.") ;
                }
 
@@ -693,45 +729,47 @@ int mainloop(int net)
                memcpy(reply.handle, request.handle, sizeof(reply.handle));
                if ((request.from + len) > (OFFT_MAX)) {
                  DEBUG("[Number too large!]");
-                 ERROR;
+                 ERROR(client, reply);
                  continue;
                }
 
-               if (((ssize_t)((off_t)request.from + len) > exportsize) ||
-                   ((flags & F_READONLY) && request.type)) {
+               if (((ssize_t)((off_t)request.from + len) > client->exportsize) ||
+                   ((client->server->flags & F_READONLY) && request.type)) {
                        DEBUG("[RANGE!]");
-                       ERROR;
+                       ERROR(client, reply);
                        continue;
                }
 
                if (request.type==1) {  /* WRITE */
                        DEBUG("wr: net->buf, ");
-                       readit(net, buf, len);
+                       readit(client->net, buf, len);
                        DEBUG("buf->exp, ");
-                       if ((autoreadonly == 1) || expwrite(request.from, buf, len)) {
+                       if ((client->server->flags & F_AUTOREADONLY) ||
+                                       expwrite(request.from, buf, len,
+                                               client)) {
                                DEBUG("Write failed: %m" );
-                               ERROR;
+                               ERROR(client, reply);
                                continue;
                        }
-                       lastpoint += len;
-                       SEND;
+                       client->lastpoint += len;
+                       SEND(client->net, reply);
                        DEBUG("OK!\n");
                        continue;
                }
                /* READ */
 
                DEBUG("exp->buf, ");
-               if (expread(request.from, buf + sizeof(struct nbd_reply), len)) {
-                       lastpoint = -1;
+               if (expread(request.from, buf + sizeof(struct nbd_reply), len, client)) {
+                       client->lastpoint = -1;
                        DEBUG("Read failed: %m");
-                       ERROR;
+                       ERROR(client, reply);
                        continue;
                }
-               lastpoint += len;
+               client->lastpoint += len;
 
                DEBUG("buf->net, ");
                memcpy(buf, &reply, sizeof(struct nbd_reply));
-               writeit(net, buf, len + sizeof(struct nbd_reply));
+               writeit(client->net, buf, len + sizeof(struct nbd_reply));
                DEBUG("OK!\n");
        }
 }
@@ -739,39 +777,45 @@ int mainloop(int net)
 /**
  * Split a single exportfile into multiple ones, if that was asked.
  * @return 0 on success, -1 on failure
+ * @param client information on the client which we want to split
  **/
-int splitexport(void) {
-       off_t i ;
+int splitexport(CLIENT* client) {
+       off_t i;
 
-       for (i=0; i<exportsize; i+=hunksize) {
-               char exportname3[1024];
+       for (i=0; i<client->exportsize; i+=client->server->hunksize) {
+               char tmpname[1024];
 
-               if(flags & F_MULTIFILE) {
-                       snprintf(exportname3, 1024, "%s.%d", exportname2, (int)(i/hunksize));
+               if(client->server->flags & F_MULTIFILE) {
+                       snprintf(tmpname, 1024, "%s.%d", client->exportname,
+                                       (int)(i/client->server->hunksize));
                } else {
-                       strncpy(exportname3, exportname2, 1024);
+                       strncpy(client->exportname, client->server->exportname, 1024);
                }
-               exportname3[1023]='\0';
-               DEBUG2( "Opening %s\n", exportname3 );
-               if ((export[i/hunksize] = open(exportname3, (flags & F_READONLY) ? O_RDONLY : O_RDWR)) == -1) {
+               tmpname[1023]='\0';
+               DEBUG2( "Opening %s\n", tmpname );
+               if ((client->export[ i/ client->server->hunksize ] =
+                                       open(tmpname, (client->server->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) 
+                       client->server->flags |= F_AUTOREADONLY;
+                       client->server->flags |= F_READONLY;
+                       if ((client->export[i/client->server->hunksize] =
+                                               open(tmpname, O_RDONLY)) == -1) 
                                err("Could not open exported file: %m");
                }
        }
 
-       if (flags & F_COPYONWRITE) {
-               snprintf(difffilename, 1024, "%s-%s-%d.diff",exportname2,clientname,
+       if (client->server->flags & F_COPYONWRITE) {
+               snprintf(client->difffilename, 1024, "%s-%s-%d.diff",client->exportname,client->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)
+               client->difffilename[1023]='\0';
+               msg3(LOG_INFO,"About to create map and diff file %s",client->difffilename) ;
+               client->difffile=open(client->difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
+               if (client->difffile<0) err("Could not create diff file (%m)") ;
+               if ((client->difmap=calloc(client->exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
                        err("Could not allocate memory") ;
-               for (i=0;i<exportsize/DIFFPAGESIZE;i++) difmap[i]=(u32)-1 ;
+               for (i=0;i<client->exportsize/DIFFPAGESIZE;i++) client->difmap[i]=(u32)-1 ;
        }
 
        return 0;
@@ -784,24 +828,29 @@ int splitexport(void) {
  *
  * @param net A network socket connected to an nbd client
  **/
-void serveconnection(int net) {
+void serveconnection(CLIENT *client) {
        char buf[80];
-       splitexport();
-       if (exportsize == OFFT_MAX) {
-               exportsize = size_autodetect(export[0]);
+       splitexport(client);
+       if (!client->server->expected_size) {
+               client->exportsize = size_autodetect(client->export[0]);
+       } else {
+               /* Perhaps we should check first. Not now. */
+               client->exportsize = client->server->expected_size;
        }
-       if (exportsize > OFFT_MAX) {
+       if (client->exportsize > OFFT_MAX) {
+               /* uhm, well... In a parallel universe, this *might* be
+                * possible... */
                err("Size of exported file is too big\n");
        }
        else {
                memset(buf, '\0', 80);
-               snprintf(buf, 79, "%Lu", (unsigned long long)exportsize);
+               snprintf(buf, 79, "%Lu", (unsigned long long)client->exportsize);
                msg3(LOG_INFO, "size of exported file/device is ", buf);
        }
 
-       setmysockopt(net);
+       setmysockopt(client->net);
 
-       mainloop(net);
+       mainloop(client);
 }
 
 /**
@@ -810,23 +859,24 @@ void serveconnection(int net) {
  * "%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.
+ * @param client information about the client. The IP address in human-readable
+ * format will be written to a new char* buffer, the address of which will be
+ * stored in client->clientname.
  **/
-void set_peername(int net,char *clientname)
-{
+void set_peername(int net, CLIENT *client) {
        struct sockaddr_in addrin;
        int addrinlen = sizeof( addrin );
        char *peername ;
 
-       if (getpeername( net, (struct sockaddr *) &addrin, &addrinlen ) < 0)
+       client->clientname=g_malloc(256);
+       if (getpeername(net, (struct sockaddr *) &addrin, (socklen_t *)&addrinlen) < 0)
                err("getsockname failed: %m");
        peername = inet_ntoa(addrin.sin_addr);
-       snprintf(exportname2, 1024, exportname, peername);
-       exportname2[1023]='\0';
+       snprintf(client->exportname, 1024, client->server->exportname, peername);
+       client->exportname[1023]='\0';
 
        msg4(LOG_INFO, "connect from %s, assigned file is %s", 
-            peername, exportname2);
+            peername, client->exportname);
        strncpy(clientname,peername,255) ;
 }
 
@@ -841,8 +891,7 @@ void set_peername(int net,char *clientname)
  *
  * @param port the port where we will listen
  **/
-void connectme(unsigned int port)
-{
+void connectme(SERVER* serve) {
        struct sockaddr_in addrin;
        struct sigaction sa;
        int addrinlen = sizeof(addrin);
@@ -856,11 +905,11 @@ void connectme(unsigned int port)
 #ifndef NOFORK
        FILE*pidf;
 
-       if(port) {
+       if((serve->port)) {
                if(daemon(0,0)<0) {
                        err("daemon");
                }
-               snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", port);
+               snprintf(pidfname, sizeof(char)*255, "/var/run/nbd-server.%d.pid", serve->port);
                pidf=fopen(pidfname, "w");
                if(pidf) {
                        fprintf(pidf,"%d", (int)getpid());
@@ -886,7 +935,7 @@ void connectme(unsigned int port)
 
        DEBUG("Waiting for connections... bind, ");
        addrin.sin_family = AF_INET;
-       addrin.sin_port = htons(port);
+       addrin.sin_port = htons(serve->port);
        addrin.sin_addr.s_addr = 0;
        if (bind(sock, (struct sockaddr *) &addrin, addrinlen) < 0)
                err("bind: %m");
@@ -904,14 +953,18 @@ void connectme(unsigned int port)
        sa.sa_flags = SA_RESTART;
        if(sigaction(SIGTERM, &sa, NULL) == -1)
                err("sigaction: %m");
-       children=malloc(sizeof(pid_t)*child_arraysize);
+       children=g_malloc(sizeof(pid_t)*child_arraysize);
        memset(children, 0, sizeof(pid_t)*DEFAULT_CHILD_ARRAY);
        for(;;) { /* infinite loop */
+               CLIENT *client;
                if ((net = accept(sock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
                        err("accept: %m");
-               
-               set_peername(net,clientname);
-               if (!authorized_client(clientname)) {
+
+               client = g_malloc(sizeof(CLIENT));
+               client->server=serve;
+               client->net=net;
+               set_peername(net, client);
+               if (!authorized_client(client)) {
                        msg2(LOG_INFO,"Unauthorized client") ;
                        close(net) ;
                        continue ;
@@ -947,37 +1000,41 @@ void connectme(unsigned int port)
                close(sock) ;
 #endif // NOFORK
                msg2(LOG_INFO,"Starting to serve") ;
-               serveconnection(net) ;        
+               serveconnection(client);
        }
 }
 
 /**
  * Main entry point...
  **/
-int main(int argc, char *argv[])
-{
+int main(int argc, char *argv[]) {
+       SERVER* serve;
        if (sizeof( struct nbd_request )!=28) {
                fprintf(stderr,"Bad size of structure. Alignment problems?\n");
                exit(-1) ;
        }
        logging();
-       cmdline(argc, argv);
+       serve=cmdline(argc, argv);
        
-       if (!port) {
+       if (!(serve->port)) {
+               CLIENT *client;
 #ifndef ISSERVER
-          /* You really should define ISSERVER if you're going to use inetd
-           * mode, but if you don't, closing stdout and stderr (which inetd
-           * had connected to the client socket) will let it work. */
-          close(1);
-          close(2);
-          open("/dev/null", O_WRONLY);
-          open("/dev/null", O_WRONLY);
+               /* You really should define ISSERVER if you're going to use inetd
+                * mode, but if you don't, closing stdout and stderr (which inetd
+                * had connected to the client socket) will let it work. */
+               close(1);
+               close(2);
+               open("/dev/null", O_WRONLY);
+               open("/dev/null", O_WRONLY);
 #endif
-          set_peername(0,clientname);
-          serveconnection(0);
-          return 0;
+               client=g_malloc(sizeof(CLIENT));
+               client->server=serve;
+               client->net=0;
+               set_peername(0,client);
+               serveconnection(0);
+               return 0;
         }
-       connectme(port); /* serve infinitely */
+       connectme(serve); /* serve infinitely */
        return 0 ;
 }