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.
19 #include <sys/ioctl.h>
20 #include <sys/socket.h>
21 #include <sys/types.h>
23 #include <netinet/tcp.h>
24 #include <netinet/in.h> /* sockaddr_in, htons, in_addr */
25 #include <netdb.h> /* hostent, gethostby*, getservby* */
30 #include <sys/mount.h>
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, int sdp) {
42 struct sockaddr_in xaddrin;
43 int xaddrinlen = sizeof(xaddrin);
44 struct hostent *hostn;
47 hostn = gethostbyname(name);
49 err("Gethostname failed: %h\n");
56 err("Can't do SDP: I was not compiled with SDP support!");
59 if ((sock = socket(af, SOCK_STREAM, IPPROTO_TCP)) < 0)
60 err("Socket failed: %m");
62 xaddrin.sin_family = af;
63 xaddrin.sin_port = htons(port);
64 xaddrin.sin_addr.s_addr = *((int *) hostn->h_addr);
65 if ((connect(sock, (struct sockaddr *) &xaddrin, xaddrinlen) < 0))
72 void negotiate(int sock, u64 *rsize64, u32 *flags) {
74 char buf[256] = "\0\0\0\0\0\0\0\0\0";
76 printf("Negotiation: ");
77 if (read(sock, buf, 8) < 0)
80 err("Server closed connection");
81 if (strcmp(buf, INIT_PASSWD))
82 err("INIT_PASSWD bad");
84 if (read(sock, &magic, sizeof(magic)) < 0)
86 magic = ntohll(magic);
87 if (magic != cliserv_magic)
88 err("Not enough cliserv_magic");
91 if (read(sock, &size64, sizeof(size64)) < 0)
92 err("Failed/3: %m\n");
93 size64 = ntohll(size64);
95 #ifdef NBD_SET_SIZE_BLOCKS
96 if ((size64>>10) > (~0UL >> 1)) {
97 printf("size = %luMB", (unsigned long)(size64>>20));
98 err("Exported device is too big for me. Get 64-bit machine :-(\n");
100 printf("size = %luKB", (unsigned long)(size64>>10));
102 if (size64 > (~0UL >> 1)) {
103 printf("size = %luKB", (unsigned long)(size64>>10));
104 err("Exported device is too big. Get 64-bit machine or newer kernel :-(\n");
106 printf("size = %lu", (unsigned long)(size64));
109 if (read(sock, flags, sizeof(*flags)) < 0)
110 err("Failed/4: %m\n");
111 *flags = ntohl(*flags);
113 if (read(sock, &buf, 124) < 0)
114 err("Failed/5: %m\n");
120 void setsizes(int nbd, u64 size64, int blocksize, u32 flags) {
122 int read_only = (flags & NBD_FLAG_READ_ONLY) ? 1 : 0;
124 #ifdef NBD_SET_SIZE_BLOCKS
125 if (size64/blocksize > (~0UL >> 1))
126 err("Device too large.\n");
129 if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0)
130 err("Ioctl/1.1a failed: %m\n");
131 size = (unsigned long)(size64/blocksize);
132 if ((er = ioctl(nbd, NBD_SET_SIZE_BLOCKS, size)) < 0)
133 err("Ioctl/1.1b failed: %m\n");
134 fprintf(stderr, "bs=%d, sz=%lu\n", blocksize, size);
137 if (size64 > (~0UL >> 1)) {
138 err("Device too large.\n");
140 size = (unsigned long)size64;
141 if (ioctl(nbd, NBD_SET_SIZE, size) < 0)
142 err("Ioctl NBD_SET_SIZE failed: %m\n");
146 ioctl(nbd, NBD_CLEAR_SOCK);
148 if (ioctl(nbd, BLKROSET, (unsigned long) &read_only) < 0)
149 err("Unable to set read-only attribute for device");
152 void set_timeout(int nbd, int timeout) {
153 #ifdef NBD_SET_TIMEOUT
155 if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)timeout) < 0)
156 err("Ioctl NBD_SET_TIMEOUT failed: %m\n");
157 fprintf(stderr, "timeout=%d\n", timeout);
162 void finish_sock(int sock, int nbd, int swap) {
163 if (ioctl(nbd, NBD_SET_SOCK, sock) < 0)
164 err("Ioctl NBD_SET_SOCK failed: %m\n");
168 err("You have to compile me on machine with swapping patch enabled in order to use it later.");
171 if (setsockopt(sock, SOL_SOCKET, SO_SWAPPING, &one, sizeof(int)) < 0)
172 err("Could not enable swapping: %m");
176 int main(int argc, char *argv[]) {
179 char *hostname, *nbddev;
191 fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION);
192 fprintf(stderr, "Usage: nbd-client [bs=blocksize] [timeout=sec] host port nbd_device [-swap] [-persist]\n");
193 fprintf(stderr, "Or : nbd-client -d nbd_device\n");
194 fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n");
195 fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
196 fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
197 fprintf(stderr, "blocksizes other than 1024 without patches\n");
201 ++argv; --argc; /* skip programname */
203 if (strcmp(argv[0], "-d")==0) {
204 nbd = open(argv[1], O_RDWR);
206 err("Can not open NBD: %m");
207 printf("Disconnecting: que, ");
208 if (ioctl(nbd, NBD_CLEAR_QUE)< 0)
209 err("Ioctl failed: %m\n");
210 printf("disconnect, ");
211 #ifdef NBD_DISCONNECT
212 if (ioctl(nbd, NBD_DISCONNECT)<0)
213 err("Ioctl failed: %m\n");
216 fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" );
219 if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
220 err("Ioctl failed: %m\n");
225 if (strncmp(argv[0], "bs=", 3)==0) {
226 blocksize=atoi(argv[0]+3);
227 ++argv; --argc; /* skip blocksize */
230 if (strncmp(argv[0], "timeout=", 8)==0) {
231 timeout=atoi(argv[0]+8);
232 ++argv; --argc; /* skip timeout */
235 if (argc==0) goto errmsg;
237 ++argv; --argc; /* skip hostname */
239 if (argc==0) goto errmsg;
240 port = atoi(argv[0]);
241 ++argv; --argc; /* skip port */
243 if (argc==0) goto errmsg;
245 nbd = open(nbddev, O_RDWR);
247 err("Can not open NBD: %m");
248 ++argv; --argc; /* skip device */
250 if (argc>3) goto errmsg;
252 if(strncmp(argv[0], "-swap", 5)==0) {
258 if(strncmp(argv[0], "-persist", 8)==0) {
264 if(strncmp(argv[0], "-sdp", 4)==0) {
269 if(argc) goto errmsg;
270 sock = opennet(hostname, port, sdp);
271 argv=NULL; argc=0; /* don't use it later suddenly */
273 negotiate(sock, &size64, &flags);
274 setsizes(nbd, size64, blocksize, flags);
275 set_timeout(nbd, timeout);
276 finish_sock(sock, nbd, swap);
287 if (ioctl(nbd, NBD_DO_IT) < 0) {
288 fprintf(stderr, "Kernel call returned: %m");
290 /* The user probably did 'nbd-client -d' on us.
298 fprintf(stderr, " Reconnecting\n");
299 close(sock); close(nbd);
300 sock = opennet(hostname, port, sdp);
301 nbd = open(nbddev, O_RDWR);
302 negotiate(sock, &new_size, &new_flags);
303 if (size64 != new_size) {
304 err("Size of the device changed. Bye");
306 setsizes(nbd, size64, blocksize,
309 set_timeout(nbd, timeout);
310 finish_sock(sock,nbd,swap);
314 /* We're on 2.4. It's not clearly defined what exactly
315 * happened at this point. Probably best to quit, now
317 fprintf(stderr, "Kernel call returned.");
321 printf("Closing: que, ");
322 ioctl(nbd, NBD_CLEAR_QUE);
324 ioctl(nbd, NBD_CLEAR_SOCK);