diff options
| -rw-r--r-- | networking/nbd-client.c | 230 |
1 files changed, 186 insertions, 44 deletions
diff --git a/networking/nbd-client.c b/networking/nbd-client.c index bedb01a1c..103756b59 100644 --- a/networking/nbd-client.c +++ b/networking/nbd-client.c @@ -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; } |