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-rw-r--r--networking/nbd-client.c230
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 @@
16#include "libbb.h" 16#include "libbb.h"
17#include <netinet/tcp.h> 17#include <netinet/tcp.h>
18#include <linux/fs.h> 18#include <linux/fs.h>
19#include <getopt.h>
19 20
20#define NBD_SET_SOCK _IO(0xab, 0) 21#define NBD_SET_SOCK _IO(0xab, 0)
21#define NBD_SET_BLKSIZE _IO(0xab, 1) 22#define NBD_SET_BLKSIZE _IO(0xab, 1)
@@ -27,57 +28,144 @@
27#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) 28#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
28#define NBD_DISCONNECT _IO(0xab, 8) 29#define NBD_DISCONNECT _IO(0xab, 8)
29#define NBD_SET_TIMEOUT _IO(0xab, 9) 30#define NBD_SET_TIMEOUT _IO(0xab, 9)
31#define NBD_SET_FLAGS _IO(0xab, 10)
30 32
31//usage:#define nbdclient_trivial_usage 33//usage:#define nbdclient_trivial_usage
32//usage: "HOST PORT BLOCKDEV" 34//usage: "{ [-b BLKSIZE] [-N NAME] [-t SEC] [-p] HOST [PORT] | -d } BLOCKDEV"
33//usage:#define nbdclient_full_usage "\n\n" 35//usage:#define nbdclient_full_usage "\n\n"
34//usage: "Connect to HOST and provide a network block device on BLOCKDEV" 36//usage: "Connect to HOST and provide network block device on BLOCKDEV"
35 37
36//TODO: more compat with nbd-client version 2.9.13 - 38//TODO: more compat with nbd-client version 3.17 -
37//Usage: nbd-client [bs=blocksize] [timeout=sec] host port nbd_device [-swap] [-persist] [-nofork] 39//nbd-client host [ port ] nbd-device [ -connections num ] [ -sdp ] [ -swap ]
38//Or : nbd-client -d nbd_device 40// [ -persist ] [ -nofork ] [ -nonetlink ] [ -systemd-mark ]
39//Or : nbd-client -c nbd_device 41// [ -block-size block size ] [ -timeout seconds ] [ -name name ]
40//Default value for blocksize is 1024 (recommended for ethernet) 42// [ -certfile certfile ] [ -keyfile keyfile ] [ -cacertfile cacertfile ]
43// [ -tlshostname hostname ]
44//nbd-client -unix path nbd-device [ -connections num ] [ -sdp ] [ -swap ]
45// [ -persist ] [ -nofork ] [ -nonetlink ] [ -systemd-mark ]
46// [ -block-size block size ] [ -timeout seconds ] [ -name name ]
47//nbd-client nbd-device
48//nbd-client -d nbd-device
49//nbd-client -c nbd-device
50//nbd-client -l host [ port ]
51//nbd-client [ -netlink ] -l host
52//
53//Default value for blocksize is 4096
41//Allowed values for blocksize are 512,1024,2048,4096 54//Allowed values for blocksize are 512,1024,2048,4096
42//Note, that kernel 2.4.2 and older ones do not work correctly with
43//blocksizes other than 1024 without patches
44 55
45int nbdclient_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 56int nbdclient_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
46int nbdclient_main(int argc UNUSED_PARAM, char **argv) 57int nbdclient_main(int argc, char **argv)
47{ 58{
48 unsigned long timeout = 0;
49#if BB_MMU 59#if BB_MMU
50 int nofork = 0; 60 bool nofork;
51#endif 61#endif
52 char *host, *port, *device; 62 bool opt_d;
63 bool opt_p;
64 const char *host, *port, *device;
65 const char *name;
66 unsigned blksize, size_blocks;
67 unsigned timeout;
68 int ch;
53 struct nbd_header_t { 69 struct nbd_header_t {
54 uint64_t magic1; // "NBDMAGIC" 70 uint64_t magic1; // "NBDMAGIC"
55 uint64_t magic2; // 0x420281861253 big endian 71 uint64_t magic2; // old style: 0x420281861253 big endian
72 // // new style: 0x49484156454F5054 (IHAVEOPT)
73 } nbd_header;
74 struct old_nbd_header_t {
56 uint64_t devsize; 75 uint64_t devsize;
57 uint32_t flags; 76 uint32_t flags;
58 char data[124]; 77 char data[124];
59 } nbd_header; 78 } old_nbd_header;
79 struct new_nbd_header_t {
80 uint64_t devsize;
81 uint16_t transmission_flags;
82 char data[124];
83 } new_nbd_header;
84 struct nbd_opt_t {
85 uint64_t magic;
86 uint32_t opt;
87 uint32_t len;
88 } nbd_opts;
60 89
61 BUILD_BUG_ON(offsetof(struct nbd_header_t, data) != 8+8+8+4); 90 static const struct option long_options[] = {
91 { "block-size", required_argument, NULL, 'b' },
92 { "timeout" , required_argument, NULL, 't' },
93 { "name" , required_argument, NULL, 'n' },
94 { "persist" , no_argument , NULL, 'p' },
95 { NULL }
96 };
62 97
63 // Parse command line stuff (just a stub now) 98 BUILD_BUG_ON(offsetof(struct old_nbd_header_t, data) != 8 + 4);
64 if (!argv[1] || !argv[2] || !argv[3] || argv[4]) 99 BUILD_BUG_ON(offsetof(struct new_nbd_header_t, data) != 8 + 2);
65 bb_show_usage();
66 100
67#if !BB_MMU 101#if !BB_MMU
68 bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv); 102 bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
69#endif 103#endif
70 104
71 host = argv[1]; 105 // Parse args. nbd-client uses stupid "one-dash long options" style :(
72 port = argv[2]; 106 // Even though short forms (-b,-t,-N,-p) exist for all long opts,
73 device = argv[3]; 107 // older manpages only contained long forms, which probably resulted
108 // in many scripts using them.
109 blksize = 4096;
110 timeout = 0;
111 name = ""; // use of "" instead of NULL simplifies strlen() later
112 opt_d = opt_p = 0;
113 while ((ch = getopt_long_only(argc, argv, "dN:", long_options, NULL)) != -1) {
114 switch (ch) {
115 case 'p': // -persist
116 opt_p = 1;
117 break;
118 case 'd': // -d
119 opt_d = 1;
120 break;
121 case 'b': // -block-size
122 blksize = xatou(optarg);
123 break;
124 case 't': // -timeout
125 timeout = xatou(optarg);
126 break;
127 case 'N': // -N
128 case 'n': // -name
129 name = optarg;
130 break;
131 default:
132 bb_show_usage();
133 }
134 }
135 argv += optind;
136
137 if (opt_d) { // -d
138 if (argv[0] && !argv[1]) {
139 int nbd = xopen(argv[0], O_RDWR);
140 ioctl(nbd, NBD_DISCONNECT);
141 ioctl(nbd, NBD_CLEAR_SOCK);
142 if (ENABLE_FEATURE_CLEAN_UP)
143 close(nbd);
144 return 0;
145 }
146 bb_show_usage();
147 }
148
149 // Allow only argv[] of: HOST [PORT] BLOCKDEV
150 if (!argv[0] || !argv[1] || (argv[2] && argv[3])) {
151 bb_show_usage();
152 }
74 153
75 // Repeat until spanked (-persist behavior) 154 host = argv[0];
76 for (;;) { 155 port = argv[2] ? argv[1] : "10809";
156 device = argv[2] ? argv[2] : argv[1];
157
158 // Repeat until spanked if -persist
159#if BB_MMU
160 nofork = 0;
161#endif
162 do {
77 int sock, nbd; 163 int sock, nbd;
78 int ro; 164 int ro;
165 int proto_new; // 0 for old, 1 for new
166 char *data;
79 167
80 // Make sure the /dev/nbd exists 168 // Make sure BLOCKDEV exists
81 nbd = xopen(device, O_RDWR); 169 nbd = xopen(device, O_RDWR);
82 170
83 // Find and connect to server 171 // Find and connect to server
@@ -85,40 +173,95 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
85 setsockopt_1(sock, IPPROTO_TCP, TCP_NODELAY); 173 setsockopt_1(sock, IPPROTO_TCP, TCP_NODELAY);
86 174
87 // Log on to the server 175 // Log on to the server
88 xread(sock, &nbd_header, 8+8+8+4 + 124); 176 xread(sock, &nbd_header, 8 + 8);
89 if (memcmp(&nbd_header.magic1, "NBDMAGIC""\x00\x00\x42\x02\x81\x86\x12\x53", 16) != 0) 177 if (memcmp(&nbd_header.magic1, "NBDMAGIC",
178 sizeof(nbd_header.magic1)) != 0
179 ) {
180 bb_error_msg_and_die("login failed");
181 }
182 if (memcmp(&nbd_header.magic2,
183 "\x00\x00\x42\x02\x81\x86\x12\x53",
184 sizeof(nbd_header.magic2)) == 0
185 ) {
186 proto_new = 0;
187 } else if (memcmp(&nbd_header.magic2, "IHAVEOPT", 8) == 0) {
188 proto_new = 1;
189 } else {
90 bb_error_msg_and_die("login failed"); 190 bb_error_msg_and_die("login failed");
191 }
192
193 if (!proto_new) {
194 xread(sock, &old_nbd_header,
195 sizeof(old_nbd_header.devsize) +
196 sizeof(old_nbd_header.flags) +
197 sizeof(old_nbd_header.data));
198 size_blocks = SWAP_BE64(old_nbd_header.devsize) / blksize;
199 ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long) blksize);
200 ioctl(nbd, NBD_SET_SIZE_BLOCKS, size_blocks);
201 ioctl(nbd, NBD_CLEAR_SOCK);
202 ro = !!(old_nbd_header.flags & htons(2));
203 data = old_nbd_header.data;
204 } else {
205 unsigned namelen;
206 uint16_t handshake_flags;
207
208 xread(sock, &handshake_flags, sizeof(handshake_flags));
209 xwrite(sock, &const_int_0, sizeof(const_int_0)); // client_flags
210
211 memcpy(&nbd_opts.magic, "IHAVEOPT",
212 sizeof(nbd_opts.magic));
213 nbd_opts.opt = htonl(1); // NBD_OPT_EXPORT_NAME
214 namelen = strlen(name);
215 nbd_opts.len = htonl(namelen);
216 xwrite(sock, &nbd_opts,
217 sizeof(nbd_opts.magic) +
218 sizeof(nbd_opts.opt) +
219 sizeof(nbd_opts.len));
220 xwrite(sock, name, namelen);
91 221
92 // Set 4k block size. Everything uses that these days 222 xread(sock, &new_nbd_header,
93 ioctl(nbd, NBD_SET_BLKSIZE, 4096); 223 sizeof(new_nbd_header.devsize) +
94 ioctl(nbd, NBD_SET_SIZE_BLOCKS, SWAP_BE64(nbd_header.devsize) / 4096); 224 sizeof(new_nbd_header.transmission_flags) +
95 ioctl(nbd, NBD_CLEAR_SOCK); 225 sizeof(new_nbd_header.data));
226 size_blocks = SWAP_BE64(new_nbd_header.devsize) / blksize;
227 ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long) blksize);
228 ioctl(nbd, NBD_SET_SIZE_BLOCKS, size_blocks);
229 ioctl(nbd, NBD_CLEAR_SOCK);
230 ioctl(nbd, NBD_SET_FLAGS,
231 ntohs(new_nbd_header.transmission_flags));
232 ro = !!(new_nbd_header.transmission_flags & htons(2));
233 data = new_nbd_header.data;
234 }
96 235
97 // If the sucker was exported read only, respect that locally 236 if (ioctl(nbd, BLKROSET, &ro) < 0) {
98 ro = (nbd_header.flags & SWAP_BE32(2)) / SWAP_BE32(2);
99 if (ioctl(nbd, BLKROSET, &ro) < 0)
100 bb_perror_msg_and_die("BLKROSET"); 237 bb_perror_msg_and_die("BLKROSET");
238 }
101 239
102 if (timeout) 240 if (timeout) {
103 if (ioctl(nbd, NBD_SET_TIMEOUT, timeout)) 241 if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long) timeout)) {
104 bb_perror_msg_and_die("NBD_SET_TIMEOUT"); 242 bb_perror_msg_and_die("NBD_SET_TIMEOUT");
105 if (ioctl(nbd, NBD_SET_SOCK, sock)) 243 }
106 bb_perror_msg_and_die("NBD_SET_SOCK"); 244 }
107 245
108 // if (swap) mlockall(MCL_CURRENT|MCL_FUTURE); 246 if (ioctl(nbd, NBD_SET_SOCK, sock)) {
247 bb_perror_msg_and_die("NBD_SET_SOCK");
248 }
109 249
250 //if (swap) mlockall(MCL_CURRENT|MCL_FUTURE);
110#if BB_MMU 251#if BB_MMU
111 // Open the device to force reread of the partition table. 252 // Open the device to force reread of the partition table.
112 // Need to do it in a separate process, since open(device) 253 // Need to do it in a separate process, since open(device)
113 // needs some other process to sit in ioctl(nbd, NBD_DO_IT). 254 // needs some other process to sit in ioctl(nbd, NBD_DO_IT).
114 if (fork() == 0) { 255 if (fork() == 0) {
256 /* child */
115 char *s = strrchr(device, '/'); 257 char *s = strrchr(device, '/');
116 sprintf(nbd_header.data, "/sys/block/%.32s/pid", s ? s + 1 : device); 258 sprintf(data, "/sys/block/%.32s/pid", s ? s + 1 : device);
117 // Is it up yet? 259 // Is it up yet?
118 for (;;) { 260 for (;;) {
119 int fd = open(nbd_header.data, O_RDONLY); 261 int fd = open(data, O_RDONLY);
120 if (fd >= 0) { 262 if (fd >= 0) {
121 //close(fd); 263 if (ENABLE_FEATURE_CLEAN_UP)
264 close(fd);
122 break; 265 break;
123 } 266 }
124 sleep(1); 267 sleep(1);
@@ -133,7 +276,6 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
133 nofork = 1; 276 nofork = 1;
134 } 277 }
135#endif 278#endif
136
137 // This turns us (the process that calls this ioctl) 279 // This turns us (the process that calls this ioctl)
138 // into a dedicated NBD request handler. 280 // into a dedicated NBD request handler.
139 // We block here for a long time. 281 // We block here for a long time.
@@ -148,7 +290,7 @@ int nbdclient_main(int argc UNUSED_PARAM, char **argv)
148 290
149 close(sock); 291 close(sock);
150 close(nbd); 292 close(nbd);
151 } 293 } while (opt_p);
152 294
153 return 0; 295 return 0;
154} 296}
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