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nbd-client: support newstyle protocol, -b, -d, -p, -N

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Recognize the "newstyle" protocol and switch to it automatically.
Add options for setting blocksize (-b) and for disconnecting
a nbd device (-d).

function                                             old     new   delta
nbdclient_main                                       492    1179    +687
static.long_options                                    -      80     +80
print_direc                                          438     457     +19
brctl_main                                          1169    1183     +14
bb_strtoll                                            84      89      +5
packed_usage                                       33082   33066     -16
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 4/1 up/down: 805/-16)           Total: 789 bytes

Signed-off-by: Elvira Khabirova <lineprinter@altlinux.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-10-24 15:51:38 +02:00
parent 3db4e7f84c
commit 4329116b6d
1 changed files with 186 additions and 44 deletions
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230
networking/nbd-client.c
View File

@ -16,6 +16,7 @@
#include "libbb.h" #include "libbb.h"
#include <netinet/tcp.h> #include <netinet/tcp.h>
#include <linux/fs.h> #include <linux/fs.h>
#include <getopt.h>
#define NBD_SET_SOCK _IO(0xab, 0) #define NBD_SET_SOCK _IO(0xab, 0)
#define NBD_SET_BLKSIZE _IO(0xab, 1) #define NBD_SET_BLKSIZE _IO(0xab, 1)
@ -27,57 +28,144 @@
#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) #define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
#define NBD_DISCONNECT _IO(0xab, 8) #define NBD_DISCONNECT _IO(0xab, 8)
#define NBD_SET_TIMEOUT _IO(0xab, 9) #define NBD_SET_TIMEOUT _IO(0xab, 9)
#define NBD_SET_FLAGS _IO(0xab, 10)
//usage:#define nbdclient_trivial_usage //usage:#define nbdclient_trivial_usage
//usage: "HOST PORT BLOCKDEV" //usage: "{ [-b BLKSIZE] [-N NAME] [-t SEC] [-p] HOST [PORT] | -d } BLOCKDEV"
//usage:#define nbdclient_full_usage "\n\n" //usage:#define nbdclient_full_usage "\n\n"
//usage: "Connect to HOST and provide a network block device on BLOCKDEV" //usage: "Connect to HOST and provide network block device on BLOCKDEV"
//TODO: more compat with nbd-client version 2.9.13 - //TODO: more compat with nbd-client version 3.17 -
//Usage: nbd-client [bs=blocksize] [timeout=sec] host port nbd_device [-swap] [-persist] [-nofork] //nbd-client host [ port ] nbd-device [ -connections num ] [ -sdp ] [ -swap ]
//Or : nbd-client -d nbd_device // [ -persist ] [ -nofork ] [ -nonetlink ] [ -systemd-mark ]
//Or : nbd-client -c nbd_device // [ -block-size block size ] [ -timeout seconds ] [ -name name ]
//Default value for blocksize is 1024 (recommended for ethernet) // [ -certfile certfile ] [ -keyfile keyfile ] [ -cacertfile cacertfile ]
// [ -tlshostname hostname ]
//nbd-client -unix path nbd-device [ -connections num ] [ -sdp ] [ -swap ]
// [ -persist ] [ -nofork ] [ -nonetlink ] [ -systemd-mark ]
// [ -block-size block size ] [ -timeout seconds ] [ -name name ]
//nbd-client nbd-device
//nbd-client -d nbd-device
//nbd-client -c nbd-device
//nbd-client -l host [ port ]
//nbd-client [ -netlink ] -l host
//
//Default value for blocksize is 4096
//Allowed values for blocksize are 512,1024,2048,4096 //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
int nbdclient_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int nbdclient_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int nbdclient_main(int argc UNUSED_PARAM, char **argv) int nbdclient_main(int argc, char **argv)
{ {
unsigned long timeout = 0;
#if BB_MMU #if BB_MMU
int nofork = 0; bool nofork;
#endif #endif
char *host, *port, *device; bool opt_d;
bool opt_p;
const char *host, *port, *device;
const char *name;
unsigned blksize, size_blocks;
unsigned timeout;
int ch;
struct nbd_header_t { struct nbd_header_t {
uint64_t magic1; // "NBDMAGIC" 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; uint64_t devsize;
uint32_t flags; uint32_t flags;
char data[124]; char data[124];
} nbd_header; } old_nbd_header;
struct new_nbd_header_t {
uint64_t devsize;
uint16_t transmission_flags;
char data[124];
} new_nbd_header;
struct nbd_opt_t {
uint64_t magic;
uint32_t opt;
uint32_t len;
} nbd_opts;
BUILD_BUG_ON(offsetof(struct nbd_header_t, data) != 8+8+8+4); static const struct option long_options[] = {
{ "block-size", required_argument, NULL, 'b' },
{ "timeout" , required_argument, NULL, 't' },
{ "name" , required_argument, NULL, 'n' },
{ "persist" , no_argument , NULL, 'p' },
{ NULL }
};
// Parse command line stuff (just a stub now) BUILD_BUG_ON(offsetof(struct old_nbd_header_t, data) != 8 + 4);
if (!argv[1] || !argv[2] || !argv[3] || argv[4]) BUILD_BUG_ON(offsetof(struct new_nbd_header_t, data) != 8 + 2);
bb_show_usage();
#if !BB_MMU #if !BB_MMU
bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv); bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
#endif #endif
host = argv[1]; // Parse args. nbd-client uses stupid "one-dash long options" style :(
port = argv[2]; // Even though short forms (-b,-t,-N,-p) exist for all long opts,
device = argv[3]; // older manpages only contained long forms, which probably resulted
// in many scripts using them.
blksize = 4096;
timeout = 0;
name = ""; // use of "" instead of NULL simplifies strlen() later
opt_d = opt_p = 0;
while ((ch = getopt_long_only(argc, argv, "dN:", long_options, NULL)) != -1) {
switch (ch) {
case 'p': // -persist
opt_p = 1;
break;
case 'd': // -d
opt_d = 1;
break;
case 'b': // -block-size
blksize = xatou(optarg);
break;
case 't': // -timeout
timeout = xatou(optarg);
break;
case 'N': // -N
case 'n': // -name
name = optarg;
break;
default:
bb_show_usage();
}
}
argv += optind;
// Repeat until spanked (-persist behavior) if (opt_d) { // -d
for (;;) { if (argv[0] && !argv[1]) {
int nbd = xopen(argv[0], O_RDWR);
ioctl(nbd, NBD_DISCONNECT);
ioctl(nbd, NBD_CLEAR_SOCK);
if (ENABLE_FEATURE_CLEAN_UP)
close(nbd);
return 0;
}
bb_show_usage();
}
// Allow only argv[] of: HOST [PORT] BLOCKDEV
if (!argv[0] || !argv[1] || (argv[2] && argv[3])) {
bb_show_usage();
}
host = argv[0];
port = argv[2] ? argv[1] : "10809";
device = argv[2] ? argv[2] : argv[1];
// Repeat until spanked if -persist
#if BB_MMU
nofork = 0;
#endif
do {
int sock, nbd; int sock, nbd;
int ro; int ro;
int proto_new; // 0 for old, 1 for new
char *data;
// Make sure the /dev/nbd exists // Make sure BLOCKDEV exists
nbd = xopen(device, O_RDWR); nbd = xopen(device, O_RDWR);
// Find and connect to server // Find and connect to server
@ -85,40 +173,95 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
setsockopt_1(sock, IPPROTO_TCP, TCP_NODELAY); setsockopt_1(sock, IPPROTO_TCP, TCP_NODELAY);
// Log on to the server // Log on to the server
xread(sock, &nbd_header, 8+8+8+4 + 124); xread(sock, &nbd_header, 8 + 8);
if (memcmp(&nbd_header.magic1, "NBDMAGIC""\x00\x00\x42\x02\x81\x86\x12\x53", 16) != 0) if (memcmp(&nbd_header.magic1, "NBDMAGIC",
sizeof(nbd_header.magic1)) != 0
) {
bb_error_msg_and_die("login failed"); 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
) {
proto_new = 0;
} else if (memcmp(&nbd_header.magic2, "IHAVEOPT", 8) == 0) {
proto_new = 1;
} else {
bb_error_msg_and_die("login failed");
}
// Set 4k block size. Everything uses that these days if (!proto_new) {
ioctl(nbd, NBD_SET_BLKSIZE, 4096); xread(sock, &old_nbd_header,
ioctl(nbd, NBD_SET_SIZE_BLOCKS, SWAP_BE64(nbd_header.devsize) / 4096); sizeof(old_nbd_header.devsize) +
ioctl(nbd, NBD_CLEAR_SOCK); 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 = !!(old_nbd_header.flags & htons(2));
data = old_nbd_header.data;
} else {
unsigned namelen;
uint16_t handshake_flags;
// If the sucker was exported read only, respect that locally xread(sock, &handshake_flags, sizeof(handshake_flags));
ro = (nbd_header.flags & SWAP_BE32(2)) / SWAP_BE32(2); xwrite(sock, &const_int_0, sizeof(const_int_0)); // client_flags
if (ioctl(nbd, BLKROSET, &ro) < 0)
memcpy(&nbd_opts.magic, "IHAVEOPT",
sizeof(nbd_opts.magic));
nbd_opts.opt = htonl(1); // NBD_OPT_EXPORT_NAME
namelen = strlen(name);
nbd_opts.len = htonl(namelen);
xwrite(sock, &nbd_opts,
sizeof(nbd_opts.magic) +
sizeof(nbd_opts.opt) +
sizeof(nbd_opts.len));
xwrite(sock, name, namelen);
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 = !!(new_nbd_header.transmission_flags & htons(2));
data = new_nbd_header.data;
}
if (ioctl(nbd, BLKROSET, &ro) < 0) {
bb_perror_msg_and_die("BLKROSET"); bb_perror_msg_and_die("BLKROSET");
}
if (timeout) if (timeout) {
if (ioctl(nbd, NBD_SET_TIMEOUT, timeout)) if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long) timeout)) {
bb_perror_msg_and_die("NBD_SET_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"); bb_perror_msg_and_die("NBD_SET_SOCK");
}
// if (swap) mlockall(MCL_CURRENT|MCL_FUTURE); //if (swap) mlockall(MCL_CURRENT|MCL_FUTURE);
#if BB_MMU #if BB_MMU
// Open the device to force reread of the partition table. // Open the device to force reread of the partition table.
// Need to do it in a separate process, since open(device) // Need to do it in a separate process, since open(device)
// needs some other process to sit in ioctl(nbd, NBD_DO_IT). // needs some other process to sit in ioctl(nbd, NBD_DO_IT).
if (fork() == 0) { if (fork() == 0) {
/* child */
char *s = strrchr(device, '/'); 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? // Is it up yet?
for (;;) { for (;;) {
int fd = open(nbd_header.data, O_RDONLY); int fd = open(data, O_RDONLY);
if (fd >= 0) { if (fd >= 0) {
//close(fd); if (ENABLE_FEATURE_CLEAN_UP)
close(fd);
break; break;
} }
sleep(1); sleep(1);
@ -133,7 +276,6 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
nofork = 1; nofork = 1;
} }
#endif #endif
// This turns us (the process that calls this ioctl) // This turns us (the process that calls this ioctl)
// into a dedicated NBD request handler. // into a dedicated NBD request handler.
// We block here for a long time. // We block here for a long time.
@ -148,7 +290,7 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
close(sock); close(sock);
close(nbd); close(nbd);
} } while (opt_p);
return 0; return 0;
} }