diff options
| -rw-r--r-- | toys/pending/nbd_client.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/toys/pending/nbd_client.c b/toys/pending/nbd_client.c new file mode 100644 index 00000000..0465eea1 --- /dev/null +++ b/toys/pending/nbd_client.c @@ -0,0 +1,166 @@ +/* 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); +} |