2 * Open connection for network block device
4 * Copyright 1997,1998 Pavel Machek, distribute under GPL
5 * <pavel@atrey.karlin.mff.cuni.cz>
7 * Version 1.0 - 64bit issues should be fixed, now
8 * Version 1.1 - added bs (blocksize) option (Alexey Guzeev, aga@permonline.ru)
9 * Version 1.2 - I added new option '-d' to send the disconnect request
10 * Version 2.0 - Version synchronised with server
11 * Version 2.1 - Check for disconnection before INIT_PASSWD is received
12 * to make errormsg a bit more helpful in case the server can't
13 * open the exported file.
20 #include <sys/ioctl.h>
21 #include <sys/socket.h>
22 #include <sys/types.h>
24 #include <netinet/tcp.h>
25 #include <netinet/in.h> /* sockaddr_in, htons, in_addr */
26 #include <netdb.h> /* hostent, gethostby*, getservby* */
33 #error I need GCC to work
36 #include <linux/ioctl.h>
37 #define MY_NAME "nbd_client"
40 int opennet(char *name, int port) {
42 struct sockaddr_in xaddrin;
43 int xaddrinlen = sizeof(xaddrin);
44 struct hostent *hostn;
46 hostn = gethostbyname(name);
48 err("Gethostname failed: %h\n");
50 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
51 err("Socket failed: %m");
53 xaddrin.sin_family = AF_INET;
54 xaddrin.sin_port = htons(port);
55 xaddrin.sin_addr.s_addr = *((int *) hostn->h_addr);
56 if ((connect(sock, (struct sockaddr *) &xaddrin, xaddrinlen) < 0))
63 u64 negotiate(int sock, int blocksize) {
65 char buf[256] = "\0\0\0\0\0\0\0\0\0";
67 printf("Negotiation: ");
68 if (read(sock, buf, 8) < 0)
71 err("Server closed connection");
72 if (strcmp(buf, INIT_PASSWD))
73 err("INIT_PASSWD bad");
75 if (read(sock, &magic, sizeof(magic)) < 0)
77 magic = ntohll(magic);
78 if (magic != cliserv_magic)
79 err("Not enough cliserv_magic");
82 if (read(sock, &size64, sizeof(size64)) < 0)
83 err("Failed/3: %m\n");
84 size64 = ntohll(size64);
86 #ifdef NBD_SET_SIZE_BLOCKS
87 if ((size64>>10) > (~0UL >> 1)) {
88 printf("size = %luMB", (unsigned long)(size64>>20));
89 err("Exported device is too big for me. Get 64-bit machine :-(\n");
91 printf("size = %luKB", (unsigned long)(size64>>10));
93 if (size64 > (~0UL >> 1)) {
94 printf("size = %luKB", (unsigned long)(size64>>10));
95 err("Exported device is too big. Get 64-bit machine or newer kernel :-(\n");
97 printf("size = %lu", (unsigned long)(size64));
100 if (read(sock, &buf, 128) < 0)
101 err("Failed/4: %m\n");
107 void setsizes(int nbd, u64 size64, int blocksize) {
110 #ifdef NBD_SET_SIZE_BLOCKS
111 if (size64/blocksize > (~0UL >> 1))
112 err("Device too large.\n");
115 if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0)
116 err("Ioctl/1.1a failed: %m\n");
117 size = (unsigned long)(size64/blocksize);
118 if ((er = ioctl(nbd, NBD_SET_SIZE_BLOCKS, size)) < 0)
119 err("Ioctl/1.1b failed: %m\n");
120 fprintf(stderr, "bs=%d, sz=%lu\n", blocksize, size);
123 if (size64 > (~0UL >> 1)) {
124 err("Device too large.\n");
126 size = (unsigned long)size64;
127 if (ioctl(nbd, NBD_SET_SIZE, size) < 0)
128 err("Ioctl NBD_SET_SIZE failed: %m\n");
132 ioctl(nbd, NBD_CLEAR_SOCK);
135 void finish_sock(int sock, int nbd, int swap) {
136 if (ioctl(nbd, NBD_SET_SOCK, sock) < 0)
137 err("Ioctl NBD_SET_SOCK failed: %m\n");
141 err("You have to compile me on machine with swapping patch enabled in order to use it later.");
144 if (setsockopt(sock, SOL_SOCKET, SO_SWAPPING, &one, sizeof(int)) < 0)
145 err("Could not enable swapping: %m");
149 int main(int argc, char *argv[]) {
152 char *hostname, *nbddev;
161 fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION);
162 fprintf(stderr, "Usage: nbd-client [bs=blocksize] host port nbd_device [-swap] [-persist]\n");
163 fprintf(stderr, "Or : nbd-client -d nbd_device\n");
164 fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n");
165 fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
166 fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
167 fprintf(stderr, "blocksizes other than 1024 without patches\n");
171 ++argv; --argc; /* skip programname */
173 if (strcmp(argv[0], "-d")==0) {
174 nbd = open(argv[1], O_RDWR);
176 err("Can not open NBD: %m");
177 printf("Disconnecting: que, ");
178 if (ioctl(nbd, NBD_CLEAR_QUE)< 0)
179 err("Ioctl failed: %m\n");
180 printf("disconnect, ");
181 #ifdef NBD_DISCONNECT
182 if (ioctl(nbd, NBD_DISCONNECT)<0)
183 err("Ioctl failed: %m\n");
186 fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" );
189 if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
190 err("Ioctl failed: %m\n");
195 if (strncmp(argv[0], "bs=", 3)==0) {
196 blocksize=atoi(argv[0]+3);
197 ++argv; --argc; /* skip blocksize */
200 if (argc==0) goto errmsg;
202 ++argv; --argc; /* skip hostname */
204 if (argc==0) goto errmsg;
205 port = atoi(argv[0]);
206 ++argv; --argc; /* skip port */
208 if (argc==0) goto errmsg;
209 sock = opennet(hostname, port);
211 nbd = open(nbddev, O_RDWR);
213 err("Can not open NBD: %m");
214 ++argv; --argc; /* skip device */
216 if (argc>2) goto errmsg;
218 if(strncmp(argv[0], "-swap", 5)==0) {
224 if(strncmp(argv[0], "-persist", 8)==0) {
229 argv=NULL; argc=0; /* don't use it later suddenly */
231 size64 = negotiate(sock, blocksize);
232 setsizes(nbd, size64, blocksize);
233 finish_sock(sock, nbd, swap);
244 if (ioctl(nbd, NBD_DO_IT) < 0) {
245 fprintf(stderr, "Kernel call returned: %m");
247 /* The user probably did 'nbd-client -d' on us.
252 fprintf(stderr, " Reconnecting\n");
253 close(sock); close(nbd);
254 sock = opennet(hostname, port);
255 nbd = open(nbddev, O_RDWR);
256 if(size64!=negotiate(sock,blocksize)) {
257 err("Size of the device changed. Bye");
259 setsizes(nbd, size64, blocksize);
260 finish_sock(sock,nbd,swap);
264 /* We're on 2.4. It's not clearly defined what exactly
265 * happened at this point. Probably best to quit, now
267 fprintf(stderr, "Kernel call returned.");
271 printf("Closing: que, ");
272 ioctl(nbd, NBD_CLEAR_QUE);
274 ioctl(nbd, NBD_CLEAR_SOCK);