Recognize the "newstyle" protocol and switch to it automatically.
Add options for setting blocksize (-b) and for disconnecting
a nbd device (-d).
Signed-off-by: Elvira Khabirova <lineprin...@altlinux.org>
---
networking/nbd-client.c | 168 +++++++++++++++++++++++++++++++++-------
1 file changed, 140 insertions(+), 28 deletions(-)
diff --git a/networking/nbd-client.c b/networking/nbd-client.c
index bedb01a1c..9e718ff93 100644
--- a/networking/nbd-client.c
+++ b/networking/nbd-client.c
@@ -27,17 +27,17 @@
#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
#define NBD_DISCONNECT _IO(0xab, 8)
#define NBD_SET_TIMEOUT _IO(0xab, 9)
+#define NBD_SET_FLAGS _IO(0xab, 10)
//usage:#define nbdclient_trivial_usage
-//usage: "HOST PORT BLOCKDEV"
+//usage: "{ [-b BLKSIZE] [-N name] HOST PORT | -d } BLOCKDEV"
//usage:#define nbdclient_full_usage "\n\n"
//usage: "Connect to HOST and provide a network block device on BLOCKDEV"
//TODO: more compat with nbd-client version 2.9.13 -
//Usage: nbd-client [bs=blocksize] [timeout=sec] host port nbd_device [-swap]
[-persist] [-nofork]
-//Or : nbd-client -d nbd_device
//Or : nbd-client -c nbd_device
-//Default value for blocksize is 1024 (recommended for ethernet)
+//Default value for blocksize is 4096
//Allowed values for blocksize are 512,1024,2048,4096
//Note, that kernel 2.4.2 and older ones do not work correctly with
//blocksizes other than 1024 without patches
@@ -45,37 +45,90 @@
int nbdclient_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int nbdclient_main(int argc UNUSED_PARAM, char **argv)
{
- unsigned long timeout = 0;
#if BB_MMU
int nofork = 0;
#endif
- char *host, *port, *device;
+ char *host, *port, *device, *name;
+ unsigned blksize, size_blocks;
+ unsigned timeout;
+ unsigned opt;
+
+ uint16_t handshake_flags;
+ uint32_t client_flags = 0;
+
struct nbd_header_t {
uint64_t magic1; // "NBDMAGIC"
- uint64_t magic2; // 0x420281861253 big endian
+ uint64_t magic2; // old style: 0x420281861253 big endian
+ // new style: 0x49484156454F5054 (IHAVEOPT)
+ } nbd_header;
+
+ struct old_nbd_header_t {
uint64_t devsize;
uint32_t flags;
char data[124];
- } nbd_header;
+ } old_nbd_header;
- BUILD_BUG_ON(offsetof(struct nbd_header_t, data) != 8+8+8+4);
+ struct new_nbd_header_t {
+ uint64_t devsize;
+ uint16_t transmission_flags;
+ char data[124];
+ } new_nbd_header;
- // Parse command line stuff (just a stub now)
- if (!argv[1] || !argv[2] || !argv[3] || argv[4])
- bb_show_usage();
+ struct nbd_opt_t {
+ uint64_t magic;
+ uint32_t opt;
+ uint32_t len;
+ } nbd_opts;
+
+ BUILD_BUG_ON(offsetof(struct old_nbd_header_t, data) != 8+4);
+ BUILD_BUG_ON(offsetof(struct new_nbd_header_t, data) != 8+2);
#if !BB_MMU
bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
#endif
- host = argv[1];
- port = argv[2];
- device = argv[3];
+ // Parse args
+ opt = getopt32(argv, "b:+t:+N:d", &blksize, &timeout, &name);
+ argv += optind;
+
+ if (opt & 0x8) {
+ if (argv[0]) {
+ int nbd = xopen(argv[0], O_RDWR);
+ ioctl(nbd, NBD_DISCONNECT);
+ ioctl(nbd, NBD_CLEAR_SOCK);
+ close(nbd);
+ return 0;
+ } else {
+ bb_show_usage();
+ }
+ }
+
+ if (!(opt & 0x1)) {
+ blksize = 4096;
+ }
+
+ if (!(opt & 0x2)) {
+ timeout = 0;
+ }
+
+ if (!(opt & 0x4)) {
+ name = NULL;
+ }
+
+ if (!argv[0] || !argv[1] || !argv[2] || argv[3]) {
+ bb_show_usage();
+ }
+
+ host = argv[0];
+ port = argv[1];
+ device = argv[2];
// Repeat until spanked (-persist behavior)
for (;;) {
int sock, nbd;
int ro;
+ int protover; // 0 for old, 1 for new
+ char *data;
// Make sure the /dev/nbd exists
nbd = xopen(device, O_RDWR);
@@ -85,25 +138,84 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
setsockopt_1(sock, IPPROTO_TCP, TCP_NODELAY);
// Log on to the server
- xread(sock, &nbd_header, 8+8+8+4 + 124);
- if (memcmp(&nbd_header.magic1,
"NBDMAGIC""\x00\x00\x42\x02\x81\x86\x12\x53", 16) != 0)
+ xread(sock, &nbd_header, 8+8);
+ if (memcmp(&nbd_header.magic1, "NBDMAGIC",
+ sizeof(nbd_header.magic1)) != 0
+ ) {
+ bb_error_msg_and_die("login failed");
+ }
+
+ if (memcmp(&nbd_header.magic2,
+ "\x00\x00\x42\x02\x81\x86\x12\x53",
+ sizeof(nbd_header.magic2)) == 0
+ ) {
+ protover = 0;
+ } else if (memcmp(&nbd_header.magic2, "IHAVEOPT", 8) == 0) {
+ protover = 1;
+ } else {
bb_error_msg_and_die("login failed");
+ }
- // Set 4k block size. Everything uses that these days
- ioctl(nbd, NBD_SET_BLKSIZE, 4096);
- ioctl(nbd, NBD_SET_SIZE_BLOCKS, SWAP_BE64(nbd_header.devsize) /
4096);
- ioctl(nbd, NBD_CLEAR_SOCK);
+ if (protover == 0) {
+ xread(sock, &old_nbd_header,
+ sizeof(old_nbd_header.devsize) +
+ sizeof(old_nbd_header.flags) +
+ sizeof(old_nbd_header.data));
+ size_blocks = SWAP_BE64(old_nbd_header.devsize) /
blksize;
+ ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long) blksize);
+ ioctl(nbd, NBD_SET_SIZE_BLOCKS, size_blocks);
+ ioctl(nbd, NBD_CLEAR_SOCK);
+ ro = !!(ntohl(old_nbd_header.flags) & 0x2);
+ data = old_nbd_header.data;
+ } else {
+ xread(sock, &handshake_flags, sizeof(handshake_flags));
+ xwrite(sock, &client_flags, sizeof(client_flags));
- // If the sucker was exported read only, respect that locally
- ro = (nbd_header.flags & SWAP_BE32(2)) / SWAP_BE32(2);
- if (ioctl(nbd, BLKROSET, &ro) < 0)
+ memcpy(&nbd_opts.magic, "IHAVEOPT",
+ sizeof(nbd_opts.magic));
+ nbd_opts.opt = htonl(0x1); // NBD_OPT_EXPORT_NAME
+ if (!name) {
+ nbd_opts.len = 0;
+ xwrite(sock, &nbd_opts,
+ sizeof(nbd_opts.magic) +
+ sizeof(nbd_opts.opt) +
+ sizeof(nbd_opts.len));
+ } else {
+ nbd_opts.len = htonl(strlen(name));
+ xwrite(sock, &nbd_opts,
+ sizeof(nbd_opts.magic) +
+ sizeof(nbd_opts.opt) +
+ sizeof(nbd_opts.len));
+ xwrite(sock, name, strlen(name));
+ }
+
+ xread(sock, &new_nbd_header,
+ sizeof(new_nbd_header.devsize) +
+ sizeof(new_nbd_header.transmission_flags) +
+ sizeof(new_nbd_header.data));
+ size_blocks = SWAP_BE64(new_nbd_header.devsize) /
blksize;
+ ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long) blksize);
+ ioctl(nbd, NBD_SET_SIZE_BLOCKS, size_blocks);
+ ioctl(nbd, NBD_CLEAR_SOCK);
+ ioctl(nbd, NBD_SET_FLAGS,
+ ntohs(new_nbd_header.transmission_flags));
+ ro = !!(ntohs(new_nbd_header.transmission_flags) & 0x2);
+ data = new_nbd_header.data;
+ }
+
+ if (ioctl(nbd, BLKROSET, &ro) < 0) {
bb_perror_msg_and_die("BLKROSET");
+ }
- if (timeout)
- if (ioctl(nbd, NBD_SET_TIMEOUT, timeout))
+ if (timeout) {
+ if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)
timeout)) {
bb_perror_msg_and_die("NBD_SET_TIMEOUT");
- if (ioctl(nbd, NBD_SET_SOCK, sock))
+ }
+ }
+
+ if (ioctl(nbd, NBD_SET_SOCK, sock)) {
bb_perror_msg_and_die("NBD_SET_SOCK");
+ }
// if (swap) mlockall(MCL_CURRENT|MCL_FUTURE);
@@ -113,10 +225,10 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
// needs some other process to sit in ioctl(nbd, NBD_DO_IT).
if (fork() == 0) {
char *s = strrchr(device, '/');
- sprintf(nbd_header.data, "/sys/block/%.32s/pid", s ? s
+ 1 : device);
+ sprintf(data, "/sys/block/%.32s/pid", s ? s + 1 :
device);
// Is it up yet?
for (;;) {
- int fd = open(nbd_header.data, O_RDONLY);
+ int fd = open(data, O_RDONLY);
if (fd >= 0) {
//close(fd);
break;
--
2.19.0
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