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)
43 struct sockaddr_in xaddrin;
44 int xaddrinlen = sizeof(xaddrin);
45 struct hostent *hostn;
47 hostn = gethostbyname(name);
49 err("Gethostname failed: %h\n");
51 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
52 err("Socket failed: %m");
54 xaddrin.sin_family = AF_INET;
55 xaddrin.sin_port = htons(port);
56 xaddrin.sin_addr.s_addr = *((int *) hostn->h_addr);
57 if ((connect(sock, (struct sockaddr *) &xaddrin, xaddrinlen) < 0))
64 int main(int argc, char *argv[])
69 char buf[256] = "\0\0\0\0\0\0\0\0\0";
78 fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION);
79 fprintf(stderr, "Usage: nbd-client [bs=blocksize] host port nbd_device [-swap]\n");
80 fprintf(stderr, "Or : nbd-client -d nbd_device\n");
81 fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n");
82 fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
83 fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
84 fprintf(stderr, "blocksizes other than 1024 without patches\n");
88 ++argv; --argc; /* skip programname */
90 if (strcmp(argv[0], "-d")==0) {
91 nbd = open(argv[1], O_RDWR);
93 err("Can not open NBD: %m");
94 printf("Disconnecting: que, ");
95 if (ioctl(nbd, NBD_CLEAR_QUE)< 0)
96 err("Ioctl failed: %m\n");
97 printf("disconnect, ");
99 if (ioctl(nbd, NBD_DISCONNECT)<0)
100 err("Ioctl failed: %m\n");
103 fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" );
106 if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
107 err("Ioctl failed: %m\n");
112 if (strncmp(argv[0], "bs=", 3)==0) {
113 blocksize=atoi(argv[0]+3);
114 ++argv; --argc; /* skip blocksize */
117 if (argc==0) goto errmsg;
119 ++argv; --argc; /* skip hostname */
121 if (argc==0) goto errmsg;
122 port = atoi(argv[0]);
123 ++argv; --argc; /* skip port */
125 if (argc==0) goto errmsg;
126 sock = opennet(hostname, port);
127 nbd = open(argv[0], O_RDWR);
129 err("Can not open NBD: %m");
130 ++argv; --argc; /* skip device */
132 if (argc>1) goto errmsg;
134 argv=NULL; argc=0; /* don't use it later suddenly */
136 printf("Negotiation: ");
137 if (read(sock, buf, 8) < 0)
140 err("Server closed connection");
141 if (strcmp(buf, INIT_PASSWD))
142 err("INIT_PASSWD bad");
144 if (read(sock, &magic, sizeof(magic)) < 0)
146 magic = ntohll(magic);
147 if (magic != cliserv_magic)
148 err("Not enough cliserv_magic");
151 if (read(sock, &size64, sizeof(size64)) < 0)
152 err("Failed/3: %m\n");
153 size64 = ntohll(size64);
155 #ifdef NBD_SET_SIZE_BLOCKS
156 if ((size64>>10) > (~0UL >> 1)) {
157 printf("size = %luMB", (unsigned long)(size64>>20));
158 err("Exported device is too big for me. Get 64-bit machine :-(\n");
160 printf("size = %luKB", (unsigned long)(size64>>10));
162 if (size64 > (~0UL >> 1)) {
163 printf("size = %luKB", (unsigned long)(size64>>10));
164 err("Exported device is too big. Get 64-bit machine or newer kernel :-(\n");
166 printf("size = %lu", (unsigned long)(size64));
169 if (read(sock, &buf, 128) < 0)
170 err("Failed/4: %m\n");
173 #ifdef NBD_SET_SIZE_BLOCKS
174 if (size64/blocksize > (~0UL >> 1))
175 err("Device too large.\n");
178 if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0)
179 err("Ioctl/1.1a failed: %m\n");
180 size = (unsigned long)(size64/blocksize);
181 if ((er = ioctl(nbd, NBD_SET_SIZE_BLOCKS, size)) < 0)
182 err("Ioctl/1.1b failed: %m\n");
183 fprintf(stderr, "bs=%d, sz=%lu\n", blocksize, size);
186 if (size64 > (~0UL >> 1)) {
187 err("Device too large.\n");
189 size = (unsigned long)size64;
190 if (ioctl(nbd, NBD_SET_SIZE, size) < 0)
191 err("Ioctl/1 failed: %m\n");
195 ioctl(nbd, NBD_CLEAR_SOCK);
196 if (ioctl(nbd, NBD_SET_SOCK, sock) < 0)
197 err("Ioctl/2 failed: %m\n");
201 err("You have to compile me on machine with swapping patch enabled in order to use it later.");
204 if (setsockopt(sock, SOL_SOCKET, SO_SWAPPING, &one, sizeof(int)) < 0)
205 err("Could not enable swapping: %m");
214 if (ioctl(nbd, NBD_DO_IT) < 0)
215 fprintf(stderr, "Kernel call returned: %m");
217 fprintf(stderr, "Kernel call returned.");
218 printf("Closing: que, ");
219 ioctl(nbd, NBD_CLEAR_QUE);
221 ioctl(nbd, NBD_CLEAR_SOCK);