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- /* nbd-client.c - network block device client
- *
- * Copyright 2010 Rob Landley <rob@landley.net>
- *
- * Not in SUSv4.
- // This little dance is because a NEWTOY with - in the name tries to do
- // things like prototype "nbd-client_main" which isn't a valid symbol. So
- // we hide the underscore name and OLDTOY the name we want.
- USE_NBD_CLIENT(NEWTOY(nbd_client, "<3>3ns", 0))
- USE_NBD_CLIENT(OLDTOY(nbd-client, nbd_client, TOYFLAG_USR|TOYFLAG_BIN))
- config NBD_CLIENT
- bool "nbd-client"
- depends on TOYBOX_FORK
- default y
- help
- usage: nbd-client [-ns] HOST PORT DEVICE
- -n Do not fork into background
- -s nbd swap support (lock server into memory)
- */
- /* TODO:
- usage: nbd-client [-sSpn] [-b BLKSZ] [-t SECS] [-N name] HOST PORT DEVICE
- -b block size
- -t timeout in seconds
- -S sdp
- -p persist
- -n nofork
- -d DEVICE
- -c DEVICE
- */
- #define FOR_nbd_client
- #include "toys.h"
- #include <linux/nbd.h>
- void nbd_client_main(void)
- {
- int sock = -1, nbd, flags;
- unsigned long timeout = 0;
- char *host=toys.optargs[0], *port=toys.optargs[1], *device=toys.optargs[2];
- uint64_t devsize;
- // Repeat until spanked
- nbd = xopen(device, O_RDWR);
- for (;;) {
- int temp;
- // Find and connect to server
- sock = xconnectany(xgetaddrinfo(host, port, AF_UNSPEC, SOCK_STREAM, 0, 0));
- temp = 1;
- setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &temp, sizeof(int));
- // Read login data
- xreadall(sock, toybuf, 152);
- if (memcmp(toybuf, "NBDMAGIC\x00\x00\x42\x02\x81\x86\x12\x53", 16))
- error_exit("bad login %s:%s", host, port);
- devsize = SWAP_BE64(*(uint64_t *)(toybuf+16));
- flags = SWAP_BE32(*(int *)(toybuf+24));
- // 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;
- xioctl(nbd, BLKROSET, &temp);
- if (timeout && ioctl(nbd, NBD_SET_TIMEOUT, timeout)<0) break;
- if (ioctl(nbd, NBD_SET_SOCK, sock) < 0) break;
- if (toys.optflags & FLAG_s) mlockall(MCL_CURRENT|MCL_FUTURE);
- // Open the device to force reread of the partition table.
- if ((toys.optflags & FLAG_n) || !xfork()) {
- char *s = strrchr(device, '/');
- int i;
- sprintf(toybuf, "/sys/block/%.32s/pid", s ? s+1 : device);
- // Is it up yet? (Give it 10 seconds.)
- for (i=0; i<100; i++) {
- temp = open(toybuf, O_RDONLY);
- if (temp == -1) msleep(100);
- else {
- close(temp);
- break;
- }
- }
- close(open(device, O_RDONLY));
- if (!(toys.optflags & FLAG_n)) exit(0);
- }
- // Daemonize here.
- if (daemon(0,0)) perror_exit("daemonize");
- // Process NBD requests until further notice.
- if (ioctl(nbd, NBD_DO_IT)>=0 || errno==EBADR) break;
- close(sock);
- }
- // Flush queue and exit.
- ioctl(nbd, NBD_CLEAR_QUE);
- ioctl(nbd, NBD_CLEAR_SOCK);
- if (CFG_TOYBOX_FREE) close(nbd);
- }
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