From 7a5ca8648b6a3ecd359bc3029b2988de452494e9 Mon Sep 17 00:00:00 2001 From: bellard Date: Tue, 27 May 2008 21:13:40 +0000 Subject: qemu-nbd tool (Anthony Liguori) git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4596 c046a42c-6fe2-441c-8c8c-71466251a162 --- nbd.c | 500 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 500 insertions(+) create mode 100644 nbd.c (limited to 'nbd.c') diff --git a/nbd.c b/nbd.c new file mode 100644 index 000000000..fcf033929 --- /dev/null +++ b/nbd.c @@ -0,0 +1,500 @@ +/*\ + * Copyright (C) 2005 Anthony Liguori + * + * 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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +\*/ + +#include "nbd.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +extern int verbose; + +#define LOG(msg, ...) do { \ + fprintf(stderr, "%s:%s():L%d: " msg "\n", \ + __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \ +} while(0) + +#define TRACE(msg, ...) do { \ + if (verbose) LOG(msg, ## __VA_ARGS__); \ +} while(0) + +/* This is all part of the "official" NBD API */ + +#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) + +/* That's all folks */ + +#define read_sync(fd, buffer, size) wr_sync(fd, buffer, size, true) +#define write_sync(fd, buffer, size) wr_sync(fd, buffer, size, false) + +static size_t 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 = read(fd, buffer + offset, size - offset); + } else { + len = write(fd, buffer + offset, size - offset); + } + + /* recoverable error */ + if (len == -1 && errno == EAGAIN) { + continue; + } + + /* eof */ + if (len == 0) { + break; + } + + /* unrecoverable error */ + if (len == -1) { + return 0; + } + + offset += len; + } + + return offset; +} + +static int tcp_socket_outgoing(const char *address, uint16_t port) +{ + int s; + struct in_addr in; + struct sockaddr_in addr; + int serrno; + + s = socket(PF_INET, SOCK_STREAM, 0); + if (s == -1) { + return -1; + } + + if (inet_aton(address, &in) == 0) { + struct hostent *ent; + + ent = gethostbyname(address); + if (ent == NULL) { + goto error; + } + + memcpy(&in, ent->h_addr, sizeof(in)); + } + + addr.sin_family = AF_INET; + addr.sin_port = htons(port); + memcpy(&addr.sin_addr.s_addr, &in, sizeof(in)); + + if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) { + goto error; + } + + return s; +error: + serrno = errno; + close(s); + errno = serrno; + return -1; +} + +int tcp_socket_incoming(const char *address, uint16_t port) +{ + int s; + struct in_addr in; + struct sockaddr_in addr; + int serrno; + int opt; + + s = socket(PF_INET, SOCK_STREAM, 0); + if (s == -1) { + return -1; + } + + if (inet_aton(address, &in) == 0) { + struct hostent *ent; + + ent = gethostbyname(address); + if (ent == NULL) { + goto error; + } + + memcpy(&in, ent->h_addr, sizeof(in)); + } + + addr.sin_family = AF_INET; + addr.sin_port = htons(port); + memcpy(&addr.sin_addr.s_addr, &in, sizeof(in)); + + opt = 1; + if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1) { + goto error; + } + + if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) { + goto error; + } + + if (listen(s, 128) == -1) { + goto error; + } + + return s; +error: + serrno = errno; + close(s); + errno = serrno; + return -1; +} + +/* Basic flow + + Server Client + + Negotiate + Request + Response + Request + Response + ... + ... + Request (type == 2) +*/ + +int nbd_negotiate(BlockDriverState *bs, 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 fd, int csock) +{ + char buf[8 + 8 + 8 + 128]; + uint64_t magic; + off_t size; + size_t blocksize; + + TRACE("Receiving negotation."); + + if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { + LOG("read failed"); + errno = EINVAL; + return -1; + } + + magic = be64_to_cpup((uint64_t*)(buf + 8)); + size = be64_to_cpup((uint64_t*)(buf + 16)); + blocksize = 1024; + + TRACE("Magic is %c%c%c%c%c%c%c%c", + isprint(buf[0]) ? buf[0] : '.', + isprint(buf[1]) ? buf[1] : '.', + isprint(buf[2]) ? buf[2] : '.', + isprint(buf[3]) ? buf[3] : '.', + isprint(buf[4]) ? buf[4] : '.', + isprint(buf[5]) ? buf[5] : '.', + isprint(buf[6]) ? buf[6] : '.', + isprint(buf[7]) ? buf[7] : '.'); + TRACE("Magic is 0x%" PRIx64, magic); + TRACE("Size is %" PRIu64, size); + + if (memcmp(buf, "NBDMAGIC", 8) != 0) { + LOG("Invalid magic received"); + errno = EINVAL; + return -1; + } + + TRACE("Checking magic"); + + if (magic != 0x00420281861253LL) { + LOG("Bad magic received"); + errno = EINVAL; + return -1; + } + + 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 %llu block(s)", + (unsigned long long)(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 csock) +{ + 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; +} + +int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, off_t *offset, bool readonly) +{ +#ifndef _REENTRANT + static uint8_t data[1024 * 1024]; // keep this off of the stack +#else + uint8_t data[1024 * 1024]; +#endif + uint8_t buf[4 + 4 + 8 + 8 + 4]; + uint32_t magic; + uint32_t type; + uint64_t from; + uint32_t len; + + TRACE("Reading request."); + + 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); + type = be32_to_cpup((uint32_t*)(buf + 4)); + from = be64_to_cpup((uint64_t*)(buf + 16)); + len = be32_to_cpup((uint32_t*)(buf + 24)); + + TRACE("Got request: " + "{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", + magic, type, from, len); + + + if (magic != NBD_REQUEST_MAGIC) { + LOG("invalid magic (got 0x%x)", magic); + errno = EINVAL; + return -1; + } + + if (len > sizeof(data)) { + LOG("len (%u) is larger than max len (%lu)", + len, sizeof(data)); + errno = EINVAL; + return -1; + } + + if ((from + len) < from) { + LOG("integer overflow detected! " + "you're probably being attacked"); + errno = EINVAL; + return -1; + } + + if ((from + len) > size) { + LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 + ", Offset: %" PRIu64 "\n", + from, len, size, dev_offset); + LOG("requested operation past EOF--bad client?"); + errno = EINVAL; + return -1; + } + + /* 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), 0); + + TRACE("Decoding type"); + + switch (type) { + case 0: + TRACE("Request type is READ"); + + if (bdrv_read(bs, (from + dev_offset) / 512, data, len / 512) == -1) { + LOG("reading from file failed"); + errno = EINVAL; + return -1; + } + *offset += len; + + TRACE("Read %u byte(s)", len); + + TRACE("Sending OK response"); + + if (write_sync(csock, buf, 16) != 16) { + LOG("writing to socket failed"); + errno = EINVAL; + return -1; + } + + TRACE("Sending data to client"); + + if (write_sync(csock, data, len) != len) { + LOG("writing to socket failed"); + errno = EINVAL; + return -1; + } + break; + case 1: + TRACE("Request type is WRITE"); + + TRACE("Reading %u byte(s)", len); + + if (read_sync(csock, data, len) != len) { + LOG("reading from socket failed"); + errno = EINVAL; + return -1; + } + + if (readonly) { + TRACE("Server is read-only, return error"); + + cpu_to_be32w((uint32_t*)(buf + 4), 1); + } else { + TRACE("Writing to device"); + + if (bdrv_write(bs, (from + dev_offset) / 512, data, len / 512) == -1) { + LOG("writing to file failed"); + errno = EINVAL; + return -1; + } + + *offset += len; + } + + TRACE("Sending response to client"); + + if (write_sync(csock, buf, 16) != 16) { + LOG("writing to socket failed"); + errno = EINVAL; + return -1; + } + break; + case 2: + TRACE("Request type is DISCONNECT"); + errno = 0; + return 1; + default: + LOG("invalid request type (%u) received", type); + errno = EINVAL; + return -1; + } + + TRACE("Request/Reply complete"); + + return 0; +} -- cgit v1.2.3