| /* |
| * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws> |
| * |
| * Network Block Device |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; under version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include "nbd.h" |
| |
| #include <errno.h> |
| #include <string.h> |
| #ifndef _WIN32 |
| #include <sys/ioctl.h> |
| #endif |
| #if defined(__sun__) || defined(__HAIKU__) |
| #include <sys/ioccom.h> |
| #endif |
| #include <ctype.h> |
| #include <inttypes.h> |
| |
| #include "qemu_socket.h" |
| |
| //#define DEBUG_NBD |
| |
| #ifdef DEBUG_NBD |
| #define TRACE(msg, ...) do { \ |
| LOG(msg, ## __VA_ARGS__); \ |
| } while(0) |
| #else |
| #define TRACE(msg, ...) \ |
| do { } while (0) |
| #endif |
| |
| #define LOG(msg, ...) do { \ |
| fprintf(stderr, "%s:%s():L%d: " msg "\n", \ |
| __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \ |
| } while(0) |
| |
| /* This is all part of the "official" NBD API */ |
| |
| #define NBD_REPLY_SIZE (4 + 4 + 8) |
| #define NBD_REQUEST_MAGIC 0x25609513 |
| #define NBD_REPLY_MAGIC 0x67446698 |
| |
| #define NBD_SET_SOCK _IO(0xab, 0) |
| #define NBD_SET_BLKSIZE _IO(0xab, 1) |
| #define NBD_SET_SIZE _IO(0xab, 2) |
| #define NBD_DO_IT _IO(0xab, 3) |
| #define NBD_CLEAR_SOCK _IO(0xab, 4) |
| #define NBD_CLEAR_QUE _IO(0xab, 5) |
| #define NBD_PRINT_DEBUG _IO(0xab, 6) |
| #define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) |
| #define NBD_DISCONNECT _IO(0xab, 8) |
| |
| #define NBD_OPT_EXPORT_NAME (1 << 0) |
| |
| /* That's all folks */ |
| |
| #define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true) |
| #define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false) |
| |
| size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read) |
| { |
| size_t offset = 0; |
| |
| while (offset < size) { |
| ssize_t len; |
| |
| if (do_read) { |
| len = recv(fd, buffer + offset, size - offset, 0); |
| } else { |
| len = send(fd, buffer + offset, size - offset, 0); |
| } |
| |
| if (len == -1) |
| errno = socket_error(); |
| |
| /* recoverable error */ |
| if (len == -1 && (errno == EAGAIN || errno == EINTR)) { |
| continue; |
| } |
| |
| /* eof */ |
| if (len == 0) { |
| break; |
| } |
| |
| /* unrecoverable error */ |
| if (len == -1) { |
| return 0; |
| } |
| |
| offset += len; |
| } |
| |
| return offset; |
| } |
| |
| static void combine_addr(char *buf, size_t len, const char* address, |
| uint16_t port) |
| { |
| /* If the address-part contains a colon, it's an IPv6 IP so needs [] */ |
| if (strstr(address, ":")) { |
| snprintf(buf, len, "[%s]:%u", address, port); |
| } else { |
| snprintf(buf, len, "%s:%u", address, port); |
| } |
| } |
| |
| int tcp_socket_outgoing(const char *address, uint16_t port) |
| { |
| char address_and_port[128]; |
| combine_addr(address_and_port, 128, address, port); |
| return tcp_socket_outgoing_spec(address_and_port); |
| } |
| |
| int tcp_socket_outgoing_spec(const char *address_and_port) |
| { |
| return inet_connect(address_and_port, SOCK_STREAM); |
| } |
| |
| int tcp_socket_incoming(const char *address, uint16_t port) |
| { |
| char address_and_port[128]; |
| combine_addr(address_and_port, 128, address, port); |
| return tcp_socket_incoming_spec(address_and_port); |
| } |
| |
| int tcp_socket_incoming_spec(const char *address_and_port) |
| { |
| char *ostr = NULL; |
| int olen = 0; |
| return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0); |
| } |
| |
| int unix_socket_incoming(const char *path) |
| { |
| char *ostr = NULL; |
| int olen = 0; |
| |
| return unix_listen(path, ostr, olen); |
| } |
| |
| int unix_socket_outgoing(const char *path) |
| { |
| return unix_connect(path); |
| } |
| |
| /* Basic flow |
| |
| Server Client |
| |
| Negotiate |
| Request |
| Response |
| Request |
| Response |
| ... |
| ... |
| Request (type == 2) |
| */ |
| |
| int nbd_negotiate(int csock, off_t size) |
| { |
| char buf[8 + 8 + 8 + 128]; |
| |
| /* Negotiate |
| [ 0 .. 7] passwd ("NBDMAGIC") |
| [ 8 .. 15] magic (0x00420281861253) |
| [16 .. 23] size |
| [24 .. 151] reserved (0) |
| */ |
| |
| TRACE("Beginning negotiation."); |
| memcpy(buf, "NBDMAGIC", 8); |
| cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL); |
| cpu_to_be64w((uint64_t*)(buf + 16), size); |
| memset(buf + 24, 0, 128); |
| |
| if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| LOG("write failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| TRACE("Negotation succeeded."); |
| |
| return 0; |
| } |
| |
| int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, |
| off_t *size, size_t *blocksize) |
| { |
| char buf[256]; |
| uint64_t magic, s; |
| uint16_t tmp; |
| |
| TRACE("Receiving negotation."); |
| |
| if (read_sync(csock, buf, 8) != 8) { |
| LOG("read failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| buf[8] = '\0'; |
| if (strlen(buf) == 0) { |
| LOG("server connection closed"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| TRACE("Magic is %c%c%c%c%c%c%c%c", |
| qemu_isprint(buf[0]) ? buf[0] : '.', |
| qemu_isprint(buf[1]) ? buf[1] : '.', |
| qemu_isprint(buf[2]) ? buf[2] : '.', |
| qemu_isprint(buf[3]) ? buf[3] : '.', |
| qemu_isprint(buf[4]) ? buf[4] : '.', |
| qemu_isprint(buf[5]) ? buf[5] : '.', |
| qemu_isprint(buf[6]) ? buf[6] : '.', |
| qemu_isprint(buf[7]) ? buf[7] : '.'); |
| |
| if (memcmp(buf, "NBDMAGIC", 8) != 0) { |
| LOG("Invalid magic received"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
| LOG("read failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| magic = be64_to_cpu(magic); |
| TRACE("Magic is 0x%" PRIx64, magic); |
| |
| if (name) { |
| uint32_t reserved = 0; |
| uint32_t opt; |
| uint32_t namesize; |
| |
| TRACE("Checking magic (opts_magic)"); |
| if (magic != 0x49484156454F5054LL) { |
| LOG("Bad magic received"); |
| errno = EINVAL; |
| return -1; |
| } |
| if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
| LOG("flags read failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| *flags = be16_to_cpu(tmp) << 16; |
| /* reserved for future use */ |
| if (write_sync(csock, &reserved, sizeof(reserved)) != |
| sizeof(reserved)) { |
| LOG("write failed (reserved)"); |
| errno = EINVAL; |
| return -1; |
| } |
| /* write the export name */ |
| magic = cpu_to_be64(magic); |
| if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
| LOG("write failed (magic)"); |
| errno = EINVAL; |
| return -1; |
| } |
| opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); |
| if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { |
| LOG("write failed (opt)"); |
| errno = EINVAL; |
| return -1; |
| } |
| namesize = cpu_to_be32(strlen(name)); |
| if (write_sync(csock, &namesize, sizeof(namesize)) != |
| sizeof(namesize)) { |
| LOG("write failed (namesize)"); |
| errno = EINVAL; |
| return -1; |
| } |
| if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) { |
| LOG("write failed (name)"); |
| errno = EINVAL; |
| return -1; |
| } |
| } else { |
| TRACE("Checking magic (cli_magic)"); |
| |
| if (magic != 0x00420281861253LL) { |
| LOG("Bad magic received"); |
| errno = EINVAL; |
| return -1; |
| } |
| } |
| |
| if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) { |
| LOG("read failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| *size = be64_to_cpu(s); |
| *blocksize = 1024; |
| TRACE("Size is %" PRIu64, *size); |
| |
| if (!name) { |
| if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) { |
| LOG("read failed (flags)"); |
| errno = EINVAL; |
| return -1; |
| } |
| *flags = be32_to_cpup(flags); |
| } else { |
| if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
| LOG("read failed (tmp)"); |
| errno = EINVAL; |
| return -1; |
| } |
| *flags |= be32_to_cpu(tmp); |
| } |
| if (read_sync(csock, &buf, 124) != 124) { |
| LOG("read failed (buf)"); |
| errno = EINVAL; |
| return -1; |
| } |
| return 0; |
| } |
| |
| #ifndef _WIN32 |
| int nbd_init(int fd, int csock, off_t size, size_t blocksize) |
| { |
| TRACE("Setting block size to %lu", (unsigned long)blocksize); |
| |
| if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) { |
| int serrno = errno; |
| LOG("Failed setting NBD block size"); |
| errno = serrno; |
| return -1; |
| } |
| |
| TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize)); |
| |
| if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) { |
| int serrno = errno; |
| LOG("Failed setting size (in blocks)"); |
| errno = serrno; |
| return -1; |
| } |
| |
| TRACE("Clearing NBD socket"); |
| |
| if (ioctl(fd, NBD_CLEAR_SOCK) == -1) { |
| int serrno = errno; |
| LOG("Failed clearing NBD socket"); |
| errno = serrno; |
| return -1; |
| } |
| |
| TRACE("Setting NBD socket"); |
| |
| if (ioctl(fd, NBD_SET_SOCK, csock) == -1) { |
| int serrno = errno; |
| LOG("Failed to set NBD socket"); |
| errno = serrno; |
| return -1; |
| } |
| |
| TRACE("Negotiation ended"); |
| |
| return 0; |
| } |
| |
| int nbd_disconnect(int fd) |
| { |
| ioctl(fd, NBD_CLEAR_QUE); |
| ioctl(fd, NBD_DISCONNECT); |
| ioctl(fd, NBD_CLEAR_SOCK); |
| return 0; |
| } |
| |
| int nbd_client(int fd) |
| { |
| int ret; |
| int serrno; |
| |
| TRACE("Doing NBD loop"); |
| |
| ret = ioctl(fd, NBD_DO_IT); |
| serrno = errno; |
| |
| TRACE("NBD loop returned %d: %s", ret, strerror(serrno)); |
| |
| TRACE("Clearing NBD queue"); |
| ioctl(fd, NBD_CLEAR_QUE); |
| |
| TRACE("Clearing NBD socket"); |
| ioctl(fd, NBD_CLEAR_SOCK); |
| |
| errno = serrno; |
| return ret; |
| } |
| #else |
| int nbd_init(int fd, int csock, off_t size, size_t blocksize) |
| { |
| errno = ENOTSUP; |
| return -1; |
| } |
| |
| int nbd_disconnect(int fd) |
| { |
| errno = ENOTSUP; |
| return -1; |
| } |
| |
| int nbd_client(int fd) |
| { |
| errno = ENOTSUP; |
| return -1; |
| } |
| #endif |
| |
| int nbd_send_request(int csock, struct nbd_request *request) |
| { |
| uint8_t buf[4 + 4 + 8 + 8 + 4]; |
| |
| cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); |
| cpu_to_be32w((uint32_t*)(buf + 4), request->type); |
| cpu_to_be64w((uint64_t*)(buf + 8), request->handle); |
| cpu_to_be64w((uint64_t*)(buf + 16), request->from); |
| cpu_to_be32w((uint32_t*)(buf + 24), request->len); |
| |
| TRACE("Sending request to client: " |
| "{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", |
| request->from, request->len, request->handle, request->type); |
| |
| if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| LOG("writing to socket failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| return 0; |
| } |
| |
| static int nbd_receive_request(int csock, struct nbd_request *request) |
| { |
| uint8_t buf[4 + 4 + 8 + 8 + 4]; |
| uint32_t magic; |
| |
| if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| LOG("read failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| /* Request |
| [ 0 .. 3] magic (NBD_REQUEST_MAGIC) |
| [ 4 .. 7] type (0 == READ, 1 == WRITE) |
| [ 8 .. 15] handle |
| [16 .. 23] from |
| [24 .. 27] len |
| */ |
| |
| magic = be32_to_cpup((uint32_t*)buf); |
| request->type = be32_to_cpup((uint32_t*)(buf + 4)); |
| request->handle = be64_to_cpup((uint64_t*)(buf + 8)); |
| request->from = be64_to_cpup((uint64_t*)(buf + 16)); |
| request->len = be32_to_cpup((uint32_t*)(buf + 24)); |
| |
| TRACE("Got request: " |
| "{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", |
| magic, request->type, request->from, request->len); |
| |
| if (magic != NBD_REQUEST_MAGIC) { |
| LOG("invalid magic (got 0x%x)", magic); |
| errno = EINVAL; |
| return -1; |
| } |
| return 0; |
| } |
| |
| int nbd_receive_reply(int csock, struct nbd_reply *reply) |
| { |
| uint8_t buf[NBD_REPLY_SIZE]; |
| uint32_t magic; |
| |
| memset(buf, 0xAA, sizeof(buf)); |
| |
| if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| LOG("read failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| /* Reply |
| [ 0 .. 3] magic (NBD_REPLY_MAGIC) |
| [ 4 .. 7] error (0 == no error) |
| [ 7 .. 15] handle |
| */ |
| |
| magic = be32_to_cpup((uint32_t*)buf); |
| reply->error = be32_to_cpup((uint32_t*)(buf + 4)); |
| reply->handle = be64_to_cpup((uint64_t*)(buf + 8)); |
| |
| TRACE("Got reply: " |
| "{ magic = 0x%x, .error = %d, handle = %" PRIu64" }", |
| magic, reply->error, reply->handle); |
| |
| if (magic != NBD_REPLY_MAGIC) { |
| LOG("invalid magic (got 0x%x)", magic); |
| errno = EINVAL; |
| return -1; |
| } |
| return 0; |
| } |
| |
| static int nbd_send_reply(int csock, struct nbd_reply *reply) |
| { |
| uint8_t buf[4 + 4 + 8]; |
| |
| /* Reply |
| [ 0 .. 3] magic (NBD_REPLY_MAGIC) |
| [ 4 .. 7] error (0 == no error) |
| [ 7 .. 15] handle |
| */ |
| cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC); |
| cpu_to_be32w((uint32_t*)(buf + 4), reply->error); |
| cpu_to_be64w((uint64_t*)(buf + 8), reply->handle); |
| |
| TRACE("Sending response to client"); |
| |
| if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| LOG("writing to socket failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| return 0; |
| } |
| |
| int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, |
| off_t *offset, bool readonly, uint8_t *data, int data_size) |
| { |
| struct nbd_request request; |
| struct nbd_reply reply; |
| |
| TRACE("Reading request."); |
| |
| if (nbd_receive_request(csock, &request) == -1) |
| return -1; |
| |
| if (request.len + NBD_REPLY_SIZE > data_size) { |
| LOG("len (%u) is larger than max len (%u)", |
| request.len + NBD_REPLY_SIZE, data_size); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| if ((request.from + request.len) < request.from) { |
| LOG("integer overflow detected! " |
| "you're probably being attacked"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| if ((request.from + request.len) > size) { |
| LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 |
| ", Offset: %" PRIu64 "\n", |
| request.from, request.len, (uint64_t)size, dev_offset); |
| LOG("requested operation past EOF--bad client?"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| TRACE("Decoding type"); |
| |
| reply.handle = request.handle; |
| reply.error = 0; |
| |
| switch (request.type) { |
| case NBD_CMD_READ: |
| TRACE("Request type is READ"); |
| |
| if (bdrv_read(bs, (request.from + dev_offset) / 512, |
| data + NBD_REPLY_SIZE, |
| request.len / 512) == -1) { |
| LOG("reading from file failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| *offset += request.len; |
| |
| TRACE("Read %u byte(s)", request.len); |
| |
| /* Reply |
| [ 0 .. 3] magic (NBD_REPLY_MAGIC) |
| [ 4 .. 7] error (0 == no error) |
| [ 7 .. 15] handle |
| */ |
| |
| cpu_to_be32w((uint32_t*)data, NBD_REPLY_MAGIC); |
| cpu_to_be32w((uint32_t*)(data + 4), reply.error); |
| cpu_to_be64w((uint64_t*)(data + 8), reply.handle); |
| |
| TRACE("Sending data to client"); |
| |
| if (write_sync(csock, data, |
| request.len + NBD_REPLY_SIZE) != |
| request.len + NBD_REPLY_SIZE) { |
| LOG("writing to socket failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| break; |
| case NBD_CMD_WRITE: |
| TRACE("Request type is WRITE"); |
| |
| TRACE("Reading %u byte(s)", request.len); |
| |
| if (read_sync(csock, data, request.len) != request.len) { |
| LOG("reading from socket failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| if (readonly) { |
| TRACE("Server is read-only, return error"); |
| reply.error = 1; |
| } else { |
| TRACE("Writing to device"); |
| |
| if (bdrv_write(bs, (request.from + dev_offset) / 512, |
| data, request.len / 512) == -1) { |
| LOG("writing to file failed"); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| *offset += request.len; |
| } |
| |
| if (nbd_send_reply(csock, &reply) == -1) |
| return -1; |
| break; |
| case NBD_CMD_DISC: |
| TRACE("Request type is DISCONNECT"); |
| errno = 0; |
| return 1; |
| default: |
| LOG("invalid request type (%u) received", request.type); |
| errno = EINVAL; |
| return -1; |
| } |
| |
| TRACE("Request/Reply complete"); |
| |
| return 0; |
| } |
