| /* 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>3ns", TOYFLAG_USR|TOYFLAG_BIN)) |
| |
| config NBD_CLIENT |
| bool "nbd-client" |
| default n |
| help |
| usage: nbd-client [-ns] HOST PORT DEVICE |
| |
| -n Do not fork into background |
| -s nbd swap support (lock server into memory) |
| */ |
| |
| /* |
| 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" |
| |
| #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; |
| |
| // Repeat until spanked |
| |
| nbd = xopen(device, O_RDWR); |
| 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; |
| close(sock); |
| } |
| freeaddrinfo(addr); |
| |
| if (!p) perror_exit("%s:%s", host, port); |
| |
| 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. |
| |
| 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); |
| } |