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4329116b6

Denys Vlasenko
Denys Vlasenko
2018-10-24
SUCCESS Duration: 148s

Subject

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

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Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

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Commit Diff GitHub →

networking/nbd-client.c +186 -44
networking/nbd-client.c+186 -44
@@ -16,6 +16,7 @@
#include "libbb.h"
#include <netinet/tcp.h>
#include <linux/fs.h>
+#include <getopt.h>
#define NBD_SET_SOCK _IO(0xab, 0)
#define NBD_SET_BLKSIZE _IO(0xab, 1)
@@ -27,57 +28,144 @@
#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] [-t SEC] [-p] HOST [PORT] | -d } BLOCKDEV"
//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 -
-//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)
+//TODO: more compat with nbd-client version 3.17 -
+//nbd-client host [ port ] nbd-device [ -connections num ] [ -sdp ] [ -swap ]
+// [ -persist ] [ -nofork ] [ -nonetlink ] [ -systemd-mark ]
+// [ -block-size block size ] [ -timeout seconds ] [ -name name ]
+// [ -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
-//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 UNUSED_PARAM, char **argv)
+int nbdclient_main(int argc, char **argv)
{
- unsigned long timeout = 0;
#if BB_MMU
- int nofork = 0;
+ bool nofork;
#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 {
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;
+ 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)
- if (!argv[1] || !argv[2] || !argv[3] || argv[4])
- bb_show_usage();
+ 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. nbd-client uses stupid "one-dash long options" style :(
+ // Even though short forms (-b,-t,-N,-p) exist for all long opts,
+ // 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;
+
+ if (opt_d) { // -d
+ 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();
+ }
- // Repeat until spanked (-persist behavior)
- for (;;) {
+ 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 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);
// 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);
// 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
+ ) {
+ proto_new = 0;
+ } else if (memcmp(&nbd_header.magic2, "IHAVEOPT", 8) == 0) {
+ proto_new = 1;
+ } else {
bb_error_msg_and_die("login failed");
+ }
+
+ if (!proto_new) {
+ 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 = !!(old_nbd_header.flags & htons(2));
+ data = old_nbd_header.data;
+ } else {
+ unsigned namelen;
+ uint16_t handshake_flags;
+
+ xread(sock, &handshake_flags, sizeof(handshake_flags));
+ xwrite(sock, &const_int_0, sizeof(const_int_0)); // client_flags
+
+ 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);
- // 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);
+ 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 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)
+ 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))
- bb_perror_msg_and_die("NBD_SET_SOCK");
+ }
+ }
- // if (swap) mlockall(MCL_CURRENT|MCL_FUTURE);
+ if (ioctl(nbd, NBD_SET_SOCK, sock)) {
+ bb_perror_msg_and_die("NBD_SET_SOCK");
+ }
+ //if (swap) mlockall(MCL_CURRENT|MCL_FUTURE);
#if BB_MMU
// Open the device to force reread of the partition table.
// Need to do it in a separate process, since open(device)
// needs some other process to sit in ioctl(nbd, NBD_DO_IT).
if (fork() == 0) {
+ /* child */
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);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(fd);
break;
}
sleep(1);
@@ -133,7 +276,6 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
nofork = 1;
}
#endif
-
// This turns us (the process that calls this ioctl)
// into a dedicated NBD request handler.
// We block here for a long time.
@@ -148,7 +290,7 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
close(sock);
close(nbd);
- }
+ } while (opt_p);
return 0;
}