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/* vi: set sw=4 ts=4:
*
* nbd-client.c - network block device client
*
* Copyright 2010 Rob Landley <rob@landley.net>
*
* Not in SUSv4.
USE_NBD_CLIENT(NEWTOY(nbd_client, "<3>3", TOYFLAG_USR|TOYFLAG_BIN))
config NBD_CLIENT
bool "nbd-client"
default n
help
Usage: nbd-client [-sSpn] [-b BLKSZ] [-t SECS] [-N name] HOST PORT DEVICE
-b block size
-t timeout in seconds
-s swap
-S sdp
-p persist
-n nofork
-d DEVICE
-c DEVICE
*/
#define FOR_nbd_client
#include "toys.h"
//#include <errno.h>
//#include <fcntl.h>
//#include <limits.h>
#include <netdb.h>
//#include <stdint.h>
//#include <stdio.h>
//#include <stdlib.h>
//#include <string.h>
//#include <unistd.h>
#include <netinet/tcp.h>
//#include <sys/ioctl.h>
//#include <sys/mount.h>
//#include <sys/types.h>
//#include <sys/socket.h>
//#include <sys/stat.h>
#define NBD_SET_SOCK _IO(0xab, 0)
#define NBD_SET_BLKSIZE _IO(0xab, 1)
#define NBD_SET_SIZE _IO(0xab, 2)
#define NBD_DO_IT _IO(0xab, 3)
#define NBD_CLEAR_SOCK _IO(0xab, 4)
#define NBD_CLEAR_QUEUE _IO(0xab, 5)
#define NBD_PRINT_DEBUG _IO(0xab, 6)
#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
#define NBD_DISCONNECT _IO(0xab, 8)
#define NBD_SET_TIMEOUT _IO(0xab, 9)
void nbd_client_main(void)
{
int sock = -1, nbd, flags;
unsigned long timeout = 0;
struct addrinfo *addr, *p;
char *host=toys.optargs[0], *port=toys.optargs[1], *device=toys.optargs[2];
uint64_t devsize;
char data[124];
// Parse command line stuff (just a stub now)
// Make sure the /dev/nbd exists.
if (0>(nbd = open(device, O_RDWR))) {
fprintf(stderr, "Can't open '%s'\n", device);
exit(1);
}
// Repeat until spanked
for (;;) {
int temp;
struct addrinfo hints;
// Find and connect to server
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
if (getaddrinfo(host, port, &hints, &addr)) addr = 0;
for (p = addr; p; p = p->ai_next) {
sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
if (-1 != connect(sock, p->ai_addr, p->ai_addrlen)) break;
}
freeaddrinfo(addr);
if (!p) {
fprintf(stderr, "Can't connect '%s' port '%s'\n", host, port);
exit(1);
}
temp = 1;
setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &temp, sizeof(int));
// Log on to the server. (Todo: one big 8+8+8+4+124=152 read)
if (read(sock, data, 8) != 8 || memcmp(data, "NBDMAGIC", 8)
|| read(sock, &devsize, 8) != 8
|| SWAP_BE64(devsize) != 0x420281861253LL
|| read(sock, &devsize, 8) != 8 || read(sock, &flags, 4) != 4
|| read(sock, data, 124) != 124)
{
fprintf(stderr, "Login fail\n");
exit(1);
}
devsize = SWAP_BE64(devsize);
flags = SWAP_BE32(flags);
// Set 4k block size. Everything uses that these days.
ioctl(nbd, NBD_SET_BLKSIZE, 4096);
ioctl(nbd, NBD_SET_SIZE_BLOCKS, devsize/4096);
ioctl(nbd, NBD_CLEAR_SOCK);
// If the sucker was exported read only, respect that locally.
temp = (flags & 2) ? 1 : 0;
if (ioctl(nbd, BLKROSET, &temp)<0) {
fprintf(stderr, "Login fail\n");
exit(1);
}
if (timeout && ioctl(nbd, NBD_SET_TIMEOUT, timeout)<0) break;
if (ioctl(nbd, NBD_SET_SOCK, sock) < 0) break;
// if (swap) mlockall(MCL_CURRENT|MCL_FUTURE);
// Open the device to force reread of the partition table.
if (!fork()) {
char *s = strrchr(device, '/');
sprintf(data, "/sys/block/%.32s/pid", s ? s+1 : device);
// Is it up yet?
for (;;) {
temp = open(data, O_RDONLY);
if (temp == -1) sleep(1);
else {
close(temp);
break;
}
}
close(open(device, O_RDONLY));
exit(0);
}
// Daemonize here.
daemon(0,0);
// Process NBD requests until further notice.
if (ioctl(nbd, NBD_DO_IT)>=0 || errno==EBADR) break;
close(sock);
close(nbd);
}
// Flush queue and exit.
ioctl(nbd, NBD_CLEAR_QUEUE);
ioctl(nbd, NBD_CLEAR_SOCK);
exit(0);
}
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