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
13 #include <sys/ioctl.h>
14 #include <sys/socket.h>
15 #include <sys/types.h>
17 #include <netinet/tcp.h>
18 #include <netinet/in.h> /* sockaddr_in, htons, in_addr */
19 #include <netdb.h> /* hostent, gethostby*, getservby* */
25 #define MY_NAME "nbd_client"
27 #error I need GCC to work
30 #include <linux/ioctl.h>
33 int opennet(char *name, int port)
36 struct sockaddr_in xaddrin;
37 int xaddrinlen = sizeof(xaddrin);
38 struct hostent *hostn;
40 hostn = gethostbyname(name);
42 err("Gethostname failed: %h\n");
44 if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
45 err("Socket failed: %m");
47 xaddrin.sin_family = AF_INET;
48 xaddrin.sin_port = htons(port);
49 xaddrin.sin_addr.s_addr = *((int *) hostn->h_addr);
50 if ((connect(sock, (struct sockaddr *) &xaddrin, xaddrinlen) < 0))
57 int main(int argc, char *argv[])
59 int port, sock, nbd, one = 1;
62 char buf[256] = "\0\0\0\0\0\0\0\0\0";
71 fprintf(stderr, "Usage: nbd-client [bs=blocksize] host port nbd_device [-swap]\n");
72 fprintf(stderr, "Or : nbd-client -d nbd_device\n");
73 fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n");
74 fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */
75 fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n");
76 fprintf(stderr, "blocksizes other than 1024 without patches\n");
80 ++argv; --argc; /* skip programname */
82 if (strcmp(argv[0], "-d")==0) {
83 nbd = open(argv[1], O_RDWR);
85 err("Can not open NBD: %m");
86 printf("Disconnecting: que, ");
87 if (ioctl(nbd, NBD_CLEAR_QUE)< 0)
88 err("Ioctl failed: %m\n");
89 printf("disconnect, ");
91 if (ioctl(nbd, NBD_DISCONNECT)<0)
92 err("Ioctl failed: %m\n");
95 fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" );
98 if (ioctl(nbd, NBD_CLEAR_SOCK)<0)
99 err("Ioctl failed: %m\n");
104 if (strncmp(argv[0], "bs=", 3)==0) {
105 blocksize=atoi(argv[0]+3);
106 ++argv; --argc; /* skip blocksize */
109 if (argc==0) goto errmsg;
111 ++argv; --argc; /* skip hostname */
113 if (argc==0) goto errmsg;
114 port = atoi(argv[0]);
115 ++argv; --argc; /* skip port */
117 if (argc==0) goto errmsg;
118 sock = opennet(hostname, port);
119 nbd = open(argv[0], O_RDWR);
121 err("Can not open NBD: %m");
122 ++argv; --argc; /* skip device */
124 if (argc>1) goto errmsg;
126 argv=NULL; argc=0; /* don't use it later suddenly */
128 printf("Negotiation: ");
129 if (read(sock, buf, 8) < 0)
131 if (strcmp(buf, INIT_PASSWD))
132 err("INIT_PASSWD bad");
134 if (read(sock, &magic, sizeof(magic)) < 0)
136 magic = ntohll(magic);
137 if (magic != cliserv_magic)
138 err("Not enough cliserv_magic");
141 if (read(sock, &size64, sizeof(size64)) < 0)
142 err("Failed/3: %m\n");
143 size64 = ntohll(size64);
145 #ifdef NBD_SET_SIZE_BLOCKS
146 if ((size64>>10) > (~0UL >> 1)) {
147 printf("size = %luMB", (unsigned long)(size64>>20));
148 err("Exported device is too big for me. Get 64-bit machine :-(\n");
150 printf("size = %luKB", (unsigned long)(size64>>10));
152 if (size64 > (~0UL >> 1)) {
153 printf("size = %luKB", (unsigned long)(size64>>10));
154 err("Exported device is too big. Get 64-bit machine or newer kernel :-(\n");
156 printf("size = %lu", (unsigned long)(size64));
159 if (read(sock, &buf, 128) < 0)
160 err("Failed/4: %m\n");
163 #ifdef NBD_SET_SIZE_BLOCKS
164 if (size64/blocksize > (~0UL >> 1))
165 err("Device too large.\n");
168 if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0)
169 err("Ioctl/1.1a failed: %m\n");
170 size = (unsigned long)(size64/blocksize);
171 if ((er = ioctl(nbd, NBD_SET_SIZE_BLOCKS, size)) < 0)
172 err("Ioctl/1.1b failed: %m\n");
173 fprintf(stderr, "bs=%d, sz=%lu\n", blocksize, size);
176 if (size64 > (~0UL >> 1)) {
177 err("Device too large.\n");
179 size = (unsigned long)size64;
180 if (ioctl(nbd, NBD_SET_SIZE, size) < 0)
181 err("Ioctl/1 failed: %m\n");
185 ioctl(nbd, NBD_CLEAR_SOCK);
186 if (ioctl(nbd, NBD_SET_SOCK, sock) < 0)
187 err("Ioctl/2 failed: %m\n");
191 err("You have to compile me on machine with swapping patch enabled in order to use it later.");
194 if (setsockopt(sock, SOL_SOCKET, SO_SWAPPING, &one, sizeof(int)) < 0)
195 err("Could not enable swapping: %m");
204 if (ioctl(nbd, NBD_DO_IT) < 0)
205 fprintf(stderr, "Kernel call returned: %m");
207 fprintf(stderr, "Kernel call returned.");
208 printf("Closing: que, ");
209 ioctl(nbd, NBD_CLEAR_QUE);
211 ioctl(nbd, NBD_CLEAR_SOCK);