/*
* Open connection for network block device
*
* Copyright 1997,1998 Pavel Machek, distribute under GPL
* <pavel@atrey.karlin.mff.cuni.cz>
*
* Version 1.0 - 64bit issues should be fixed, now
* Version 1.1 - added bs (blocksize) option (Alexey Guzeev, aga@permonline.ru)
* Version 1.2 - I added new option '-d' to send the disconnect request
* Version 2.0 - Version synchronised with server
* Version 2.1 - Check for disconnection before INIT_PASSWD is received
* to make errormsg a bit more helpful in case the server can't
* open the exported file.
*/
#include "config.h"
#include "lfs.h"
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include <netinet/tcp.h>
#include <netinet/in.h> /* sockaddr_in, htons, in_addr */
#include <netdb.h> /* hostent, gethostby*, getservby* */
#include <stdio.h>
#include <fcntl.h>
#include <syslog.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <errno.h>
#ifndef __GNUC__
#error I need GCC to work
#endif
#include <linux/ioctl.h>
#define MY_NAME "nbd_client"
#include "cliserv.h"
int check_conn(char* devname, int do_print) {
char buf[256];
int fd;
int len;
if(!strncmp(devname, "/dev/", 5)) {
devname+=5;
}
snprintf(buf, 256, "/sys/block/%s/pid", devname);
if((fd=open(buf, O_RDONLY))<0) {
if(errno==ENOENT) {
return 1;
} else {
return 2;
}
}
len=read(fd, buf, 256);
buf[len-1]='\0';
if(do_print) printf("%s\n", buf);
return 0;
}
int opennet(char *name, int port, int sdp) {
int sock;
struct sockaddr_in xaddrin;
int xaddrinlen = sizeof(xaddrin);
struct hostent *hostn;
int af;
hostn = gethostbyname(name);
if (!hostn)
err("Gethostname failed: %h\n");
af = AF_INET;
if(sdp) {
#ifdef WITH_SDP
af = AF_INET_SDP;
#else
err("Can't do SDP: I was not compiled with SDP support!");
#endif
}
if ((sock = socket(af, SOCK_STREAM, IPPROTO_TCP)) < 0)
err("Socket failed: %m");
xaddrin.sin_family = af;
xaddrin.sin_port = htons(port);
xaddrin.sin_addr.s_addr = *((int *) hostn->h_addr);
if ((connect(sock, (struct sockaddr *) &xaddrin, xaddrinlen) < 0))
err("Connect: %m");
setmysockopt(sock);
return sock;
}
void negotiate(int sock, u64 *rsize64, u32 *flags) {
u64 magic, size64;
char buf[256] = "\0\0\0\0\0\0\0\0\0";
printf("Negotiation: ");
if (read(sock, buf, 8) < 0)
err("Failed/1: %m");
if (strlen(buf)==0)
err("Server closed connection");
if (strcmp(buf, INIT_PASSWD))
err("INIT_PASSWD bad");
printf(".");
if (read(sock, &magic, sizeof(magic)) < 0)
err("Failed/2: %m");
magic = ntohll(magic);
if (magic != cliserv_magic)
err("Not enough cliserv_magic");
printf(".");
if (read(sock, &size64, sizeof(size64)) < 0)
err("Failed/3: %m\n");
size64 = ntohll(size64);
#ifdef NBD_SET_SIZE_BLOCKS
if ((size64>>10) > (~0UL >> 1)) {
printf("size = %luMB", (unsigned long)(size64>>20));
err("Exported device is too big for me. Get 64-bit machine :-(\n");
} else
printf("size = %luKB", (unsigned long)(size64>>10));
#else
if (size64 > (~0UL >> 1)) {
printf("size = %luKB", (unsigned long)(size64>>10));
err("Exported device is too big. Get 64-bit machine or newer kernel :-(\n");
} else
printf("size = %lu", (unsigned long)(size64));
#endif
if (read(sock, flags, sizeof(*flags)) < 0)
err("Failed/4: %m\n");
*flags = ntohl(*flags);
if (read(sock, &buf, 124) < 0)
err("Failed/5: %m\n");
printf("\n");
*rsize64 = size64;
}
void setsizes(int nbd, u64 size64, int blocksize, u32 flags) {
unsigned long size;
int read_only = (flags & NBD_FLAG_READ_ONLY) ? 1 : 0;
#ifdef NBD_SET_SIZE_BLOCKS
if (size64/blocksize > (~0UL >> 1))
err("Device too large.\n");
else {
int er;
if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0)
err("Ioctl/1.1a failed: %m\n");
size = (unsigned long)(size64/blocksize);
if ((er = ioctl(nbd, NBD_SET_SIZE_BLOCKS, size)) < 0)
err("Ioctl/1.1b failed: %m\n");
fprintf(stderr, "bs=%d, sz=%lu\n", blocksize, size);
}
#else
if (size64 > (~0UL >> 1)) {
err("Device too large.\n");
} else {
size = (unsigned long)size64;
if (ioctl(nbd, NBD_SET_SIZE, size) < 0)
err("Ioctl NBD_SET_SIZE failed: %m\n");
}
#endif
ioctl(nbd, NBD_CLEAR_SOCK);
if (ioctl(nbd, BLKROSET, (unsigned long) &read_only) < 0)
err("Unable to set read-only attribute for device");
}
void set_timeout(int nbd, int timeout) {
#ifdef NBD_SET_TIMEOUT
if (timeout) {
if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)timeout) < 0)
err("Ioctl NBD_SET_TIMEOUT failed: %m\n");
fprintf(stderr, "timeout=%d\n", timeout);
}
#endif
}
void finish_sock(int sock, int nbd, int swap) {
if (ioctl(nbd, NBD_SET_SOCK, sock) < 0)
err("Ioctl NBD_SET_SOCK failed: %m\n");
#ifndef SO_SWAPPING
if (swap)
err("You have to compile me on machine with swapping patch enabled in order to use it later.");
#else
if (swap)
if (setsockopt(sock, SOL_SOCKET, SO_SWAPPING, &one, sizeof(int)) < 0)
err("Could not enable swapping: %m");
#endif
}
int main(int argc, char *argv[]) {
int port, sock, nbd;
int blocksize=1024;
char *hostname, *nbddev;
int swap=0;
int cont=0;
int timeout=0;
int sdp=0;
u64 size64;
u32 flags;
logging();
if (argc < 3) {
errmsg:
fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION);
fprintf(stderr, "Usage: nbd-client [bs=blocksize] [timeout=sec] host port nbd_device [-swap] [-persist]\n");
fprintf(stderr, "Or : nbd-client -d nbd_device\n");
fprintf(stderr, "Or : nbd-client -c nbd_device\n");
fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n");
fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
fprintf(stderr, "blocksizes other than 1024 without patches\n");
return 1;
}
++argv; --argc; /* skip programname */
if (strcmp(argv[0], "-d")==0) {
nbd = open(argv[1], O_RDWR);
if (nbd < 0)
err("Can not open NBD: %m");
printf("Disconnecting: que, ");
if (ioctl(nbd, NBD_CLEAR_QUE)< 0)
err("Ioctl failed: %m\n");
printf("disconnect, ");
#ifdef NBD_DISCONNECT
if (ioctl(nbd, NBD_DISCONNECT)<0)
err("Ioctl failed: %m\n");
printf("sock, ");
#else
fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" );
exit(1);
#endif
if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
err("Ioctl failed: %m\n");
printf("done\n");
return 0;
}
if(strcmp(argv[0], "-c")==0) {
return check_conn(argv[1], 1);
}
if (strncmp(argv[0], "bs=", 3)==0) {
blocksize=atoi(argv[0]+3);
++argv; --argc; /* skip blocksize */
}
if (strncmp(argv[0], "timeout=", 8)==0) {
timeout=atoi(argv[0]+8);
++argv; --argc; /* skip timeout */
}
if (argc==0) goto errmsg;
hostname=argv[0];
++argv; --argc; /* skip hostname */
if (argc==0) goto errmsg;
port = atoi(argv[0]);
++argv; --argc; /* skip port */
if (argc==0) goto errmsg;
nbddev = argv[0];
nbd = open(nbddev, O_RDWR);
if (nbd < 0)
err("Can not open NBD: %m");
++argv; --argc; /* skip device */
if (argc>3) goto errmsg;
if (argc) {
if(strncmp(argv[0], "-swap", 5)==0) {
swap=1;
++argv;--argc;
}
}
if (argc) {
if(strncmp(argv[0], "-persist", 8)==0) {
cont=1;
++argv;--argc;
}
}
if (argc) {
if(strncmp(argv[0], "-sdp", 4)==0) {
sdp=1;
++argv;--argc;
}
}
if(argc) goto errmsg;
sock = opennet(hostname, port, sdp);
argv=NULL; argc=0; /* don't use it later suddenly */
negotiate(sock, &size64, &flags);
setsizes(nbd, size64, blocksize, flags);
set_timeout(nbd, timeout);
finish_sock(sock, nbd, swap);
/* Go daemon */
chdir("/");
do {
#ifndef NOFORK
if (fork()) {
while(check_conn(nbddev, 0)) {
sleep(1);
}
open(nbddev, O_RDONLY);
exit(0);
}
#endif
if (ioctl(nbd, NBD_DO_IT) < 0) {
fprintf(stderr, "Kernel call returned: %m");
if(errno==EBADR) {
/* The user probably did 'nbd-client -d' on us.
* quit */
cont=0;
} else {
if(cont) {
u64 new_size;
u32 new_flags;
fprintf(stderr, " Reconnecting\n");
close(sock); close(nbd);
sock = opennet(hostname, port, sdp);
nbd = open(nbddev, O_RDWR);
negotiate(sock, &new_size, &new_flags);
if (size64 != new_size) {
err("Size of the device changed. Bye");
}
setsizes(nbd, size64, blocksize,
new_flags);
set_timeout(nbd, timeout);
finish_sock(sock,nbd,swap);
}
}
} else {
/* We're on 2.4. It's not clearly defined what exactly
* happened at this point. Probably best to quit, now
*/
fprintf(stderr, "Kernel call returned.");
cont=0;
}
} while(cont);
printf("Closing: que, ");
ioctl(nbd, NBD_CLEAR_QUE);
printf("sock, ");
ioctl(nbd, NBD_CLEAR_SOCK);
printf("done\n");
return 0;
}
