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>
34 #error I need GCC to work
37 #include <linux/ioctl.h>
38 #define MY_NAME "nbd_client"
41 int check_conn(char* devname, int do_print) {
45 if(!strncmp(devname, "/dev/", 5)) {
48 snprintf(buf, 256, "/sys/block/%s/pid", devname);
49 if((fd=open(buf, O_RDONLY))<0) {
56 len=read(fd, buf, 256);
58 if(do_print) printf("%s\n", buf);
62 int opennet(char *name, int port, int sdp) {
64 struct sockaddr_in xaddrin;
65 int xaddrinlen = sizeof(xaddrin);
66 struct hostent *hostn;
69 hostn = gethostbyname(name);
71 err("Gethostname failed: %h\n");
78 err("Can't do SDP: I was not compiled with SDP support!");
81 if ((sock = socket(af, SOCK_STREAM, IPPROTO_TCP)) < 0)
82 err("Socket failed: %m");
84 xaddrin.sin_family = af;
85 xaddrin.sin_port = htons(port);
86 xaddrin.sin_addr.s_addr = *((int *) hostn->h_addr);
87 if ((connect(sock, (struct sockaddr *) &xaddrin, xaddrinlen) < 0))
94 void negotiate(int sock, u64 *rsize64, u32 *flags) {
96 char buf[256] = "\0\0\0\0\0\0\0\0\0";
98 printf("Negotiation: ");
99 if (read(sock, buf, 8) < 0)
102 err("Server closed connection");
103 if (strcmp(buf, INIT_PASSWD))
104 err("INIT_PASSWD bad");
106 if (read(sock, &magic, sizeof(magic)) < 0)
108 magic = ntohll(magic);
109 if (magic != cliserv_magic)
110 err("Not enough cliserv_magic");
113 if (read(sock, &size64, sizeof(size64)) < 0)
114 err("Failed/3: %m\n");
115 size64 = ntohll(size64);
117 #ifdef NBD_SET_SIZE_BLOCKS
118 if ((size64>>10) > (~0UL >> 1)) {
119 printf("size = %luMB", (unsigned long)(size64>>20));
120 err("Exported device is too big for me. Get 64-bit machine :-(\n");
122 printf("size = %luKB", (unsigned long)(size64>>10));
124 if (size64 > (~0UL >> 1)) {
125 printf("size = %luKB", (unsigned long)(size64>>10));
126 err("Exported device is too big. Get 64-bit machine or newer kernel :-(\n");
128 printf("size = %lu", (unsigned long)(size64));
131 if (read(sock, flags, sizeof(*flags)) < 0)
132 err("Failed/4: %m\n");
133 *flags = ntohl(*flags);
135 if (read(sock, &buf, 124) < 0)
136 err("Failed/5: %m\n");
142 void setsizes(int nbd, u64 size64, int blocksize, u32 flags) {
144 int read_only = (flags & NBD_FLAG_READ_ONLY) ? 1 : 0;
146 #ifdef NBD_SET_SIZE_BLOCKS
147 if (size64/blocksize > (~0UL >> 1))
148 err("Device too large.\n");
151 if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0)
152 err("Ioctl/1.1a failed: %m\n");
153 size = (unsigned long)(size64/blocksize);
154 if ((er = ioctl(nbd, NBD_SET_SIZE_BLOCKS, size)) < 0)
155 err("Ioctl/1.1b failed: %m\n");
156 fprintf(stderr, "bs=%d, sz=%lu\n", blocksize, size);
159 if (size64 > (~0UL >> 1)) {
160 err("Device too large.\n");
162 size = (unsigned long)size64;
163 if (ioctl(nbd, NBD_SET_SIZE, size) < 0)
164 err("Ioctl NBD_SET_SIZE failed: %m\n");
168 ioctl(nbd, NBD_CLEAR_SOCK);
170 if (ioctl(nbd, BLKROSET, (unsigned long) &read_only) < 0)
171 err("Unable to set read-only attribute for device");
174 void set_timeout(int nbd, int timeout) {
175 #ifdef NBD_SET_TIMEOUT
177 if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)timeout) < 0)
178 err("Ioctl NBD_SET_TIMEOUT failed: %m\n");
179 fprintf(stderr, "timeout=%d\n", timeout);
184 void finish_sock(int sock, int nbd, int swap) {
185 if (ioctl(nbd, NBD_SET_SOCK, sock) < 0)
186 err("Ioctl NBD_SET_SOCK failed: %m\n");
190 err("You have to compile me on machine with swapping patch enabled in order to use it later.");
193 if (setsockopt(sock, SOL_SOCKET, SO_SWAPPING, &one, sizeof(int)) < 0)
194 err("Could not enable swapping: %m");
198 int main(int argc, char *argv[]) {
201 char *hostname, *nbddev;
213 fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION);
214 fprintf(stderr, "Usage: nbd-client [bs=blocksize] [timeout=sec] host port nbd_device [-swap] [-persist]\n");
215 fprintf(stderr, "Or : nbd-client -d nbd_device\n");
216 fprintf(stderr, "Or : nbd-client -c nbd_device\n");
217 fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n");
218 fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
219 fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
220 fprintf(stderr, "blocksizes other than 1024 without patches\n");
224 ++argv; --argc; /* skip programname */
226 if (strcmp(argv[0], "-d")==0) {
227 nbd = open(argv[1], O_RDWR);
229 err("Can not open NBD: %m");
230 printf("Disconnecting: que, ");
231 if (ioctl(nbd, NBD_CLEAR_QUE)< 0)
232 err("Ioctl failed: %m\n");
233 printf("disconnect, ");
234 #ifdef NBD_DISCONNECT
235 if (ioctl(nbd, NBD_DISCONNECT)<0)
236 err("Ioctl failed: %m\n");
239 fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" );
242 if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
243 err("Ioctl failed: %m\n");
247 if(strcmp(argv[0], "-c")==0) {
248 return check_conn(argv[1], 1);
251 if (strncmp(argv[0], "bs=", 3)==0) {
252 blocksize=atoi(argv[0]+3);
253 ++argv; --argc; /* skip blocksize */
256 if (strncmp(argv[0], "timeout=", 8)==0) {
257 timeout=atoi(argv[0]+8);
258 ++argv; --argc; /* skip timeout */
261 if (argc==0) goto errmsg;
263 ++argv; --argc; /* skip hostname */
265 if (argc==0) goto errmsg;
266 port = atoi(argv[0]);
267 ++argv; --argc; /* skip port */
269 if (argc==0) goto errmsg;
271 nbd = open(nbddev, O_RDWR);
273 err("Can not open NBD: %m");
274 ++argv; --argc; /* skip device */
276 if (argc>3) goto errmsg;
278 if(strncmp(argv[0], "-swap", 5)==0) {
284 if(strncmp(argv[0], "-persist", 8)==0) {
290 if(strncmp(argv[0], "-sdp", 4)==0) {
295 if(argc) goto errmsg;
296 sock = opennet(hostname, port, sdp);
297 argv=NULL; argc=0; /* don't use it later suddenly */
299 negotiate(sock, &size64, &flags);
300 setsizes(nbd, size64, blocksize, flags);
301 set_timeout(nbd, timeout);
302 finish_sock(sock, nbd, swap);
310 while(check_conn(nbddev, 0)) {
313 open(nbddev, O_RDONLY);
318 if (ioctl(nbd, NBD_DO_IT) < 0) {
319 fprintf(stderr, "Kernel call returned: %m");
321 /* The user probably did 'nbd-client -d' on us.
329 fprintf(stderr, " Reconnecting\n");
330 close(sock); close(nbd);
331 sock = opennet(hostname, port, sdp);
332 nbd = open(nbddev, O_RDWR);
333 negotiate(sock, &new_size, &new_flags);
334 if (size64 != new_size) {
335 err("Size of the device changed. Bye");
337 setsizes(nbd, size64, blocksize,
340 set_timeout(nbd, timeout);
341 finish_sock(sock,nbd,swap);
345 /* We're on 2.4. It's not clearly defined what exactly
346 * happened at this point. Probably best to quit, now
348 fprintf(stderr, "Kernel call returned.");
352 printf("Closing: que, ");
353 ioctl(nbd, NBD_CLEAR_QUE);
355 ioctl(nbd, NBD_CLEAR_SOCK);