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https://github.com/Motorhead1991/qemu.git
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Allow QEMU to connect directly to an NBD server, by Laurent Vivier.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4838 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
ths
parent
3b05a8e91b
commit
75818250ba
9 changed files with 413 additions and 77 deletions
213
nbd.c
213
nbd.c
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@ -1,4 +1,4 @@
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/*\
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/*
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* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
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*
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* Network Block Device
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@ -15,7 +15,7 @@
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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\*/
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*/
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#include "nbd.h"
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@ -31,17 +31,21 @@
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#include <arpa/inet.h>
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#include <netdb.h>
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#if defined(QEMU_NBD)
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extern int verbose;
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#else
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static int verbose = 0;
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#endif
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#define TRACE(msg, ...) do { \
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if (verbose) LOG(msg, ## __VA_ARGS__); \
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} while(0)
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#define LOG(msg, ...) do { \
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fprintf(stderr, "%s:%s():L%d: " msg "\n", \
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__FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
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} while(0)
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#define TRACE(msg, ...) do { \
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if (verbose) LOG(msg, ## __VA_ARGS__); \
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} while(0)
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/* This is all part of the "official" NBD API */
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#define NBD_REQUEST_MAGIC 0x25609513
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@ -59,10 +63,10 @@ extern int verbose;
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/* That's all folks */
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#define read_sync(fd, buffer, size) wr_sync(fd, buffer, size, true)
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#define write_sync(fd, buffer, size) wr_sync(fd, buffer, size, false)
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#define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
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#define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false)
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static size_t wr_sync(int fd, void *buffer, size_t size, bool do_read)
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size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
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{
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size_t offset = 0;
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@ -76,7 +80,7 @@ static size_t wr_sync(int fd, void *buffer, size_t size, bool do_read)
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}
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/* recoverable error */
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if (len == -1 && errno == EAGAIN) {
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if (len == -1 && (errno == EAGAIN || errno == EINTR)) {
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continue;
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}
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@ -96,7 +100,7 @@ static size_t wr_sync(int fd, void *buffer, size_t size, bool do_read)
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return offset;
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}
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static int tcp_socket_outgoing(const char *address, uint16_t port)
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int tcp_socket_outgoing(const char *address, uint16_t port)
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{
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int s;
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struct in_addr in;
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@ -404,16 +408,31 @@ int nbd_client(int fd, int csock)
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return ret;
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}
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int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
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off_t *offset, bool readonly, uint8_t *data, int data_size)
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int nbd_send_request(int csock, struct nbd_request *request)
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{
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uint8_t buf[4 + 4 + 8 + 8 + 4];
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cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
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cpu_to_be32w((uint32_t*)(buf + 4), request->type);
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cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
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cpu_to_be64w((uint64_t*)(buf + 16), request->from);
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cpu_to_be32w((uint32_t*)(buf + 24), request->len);
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TRACE("Sending request to client");
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if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
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LOG("writing to socket failed");
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errno = EINVAL;
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return -1;
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}
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return 0;
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}
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static int nbd_receive_request(int csock, struct nbd_request *request)
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{
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uint8_t buf[4 + 4 + 8 + 8 + 4];
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uint32_t magic;
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uint32_t type;
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uint64_t from;
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uint32_t len;
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TRACE("Reading request.");
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if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
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LOG("read failed");
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@ -422,97 +441,158 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
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}
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/* Request
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[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
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[ 4 .. 7] type (0 == READ, 1 == WRITE)
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[ 8 .. 15] handle
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[16 .. 23] from
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[24 .. 27] len
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[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
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[ 4 .. 7] type (0 == READ, 1 == WRITE)
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[ 8 .. 15] handle
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[16 .. 23] from
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[24 .. 27] len
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*/
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magic = be32_to_cpup((uint32_t*)buf);
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type = be32_to_cpup((uint32_t*)(buf + 4));
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from = be64_to_cpup((uint64_t*)(buf + 16));
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len = be32_to_cpup((uint32_t*)(buf + 24));
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request->type = be32_to_cpup((uint32_t*)(buf + 4));
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request->handle = be64_to_cpup((uint64_t*)(buf + 8));
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request->from = be64_to_cpup((uint64_t*)(buf + 16));
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request->len = be32_to_cpup((uint32_t*)(buf + 24));
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TRACE("Got request: "
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"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
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magic, type, from, len);
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magic, request->type, request->from, request->len);
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if (magic != NBD_REQUEST_MAGIC) {
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LOG("invalid magic (got 0x%x)", magic);
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errno = EINVAL;
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return -1;
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}
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}
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if (len > data_size) {
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LOG("len (%u) is larger than max len (%u)",
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len, data_size);
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int nbd_receive_reply(int csock, struct nbd_reply *reply)
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{
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uint8_t buf[4 + 4 + 8];
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uint32_t magic;
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memset(buf, 0xAA, sizeof(buf));
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if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
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LOG("read failed");
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errno = EINVAL;
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return -1;
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}
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if ((from + len) < from) {
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/* Reply
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[ 0 .. 3] magic (NBD_REPLY_MAGIC)
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[ 4 .. 7] error (0 == no error)
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[ 7 .. 15] handle
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*/
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magic = be32_to_cpup((uint32_t*)buf);
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reply->error = be32_to_cpup((uint32_t*)(buf + 4));
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reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
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TRACE("Got reply: "
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"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
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magic, reply->error, reply->handle);
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if (magic != NBD_REPLY_MAGIC) {
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LOG("invalid magic (got 0x%x)", magic);
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errno = EINVAL;
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return -1;
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}
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return 0;
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}
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static int nbd_send_reply(int csock, struct nbd_reply *reply)
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{
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uint8_t buf[4 + 4 + 8];
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/* Reply
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[ 0 .. 3] magic (NBD_REPLY_MAGIC)
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[ 4 .. 7] error (0 == no error)
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[ 7 .. 15] handle
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*/
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cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
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cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
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cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
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TRACE("Sending response to client");
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if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
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LOG("writing to socket failed");
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errno = EINVAL;
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return -1;
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}
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return 0;
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}
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int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
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off_t *offset, bool readonly, uint8_t *data, int data_size)
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{
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struct nbd_request request;
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struct nbd_reply reply;
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TRACE("Reading request.");
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if (nbd_receive_request(csock, &request) == -1)
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return -1;
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if (request.len > data_size) {
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LOG("len (%u) is larger than max len (%u)",
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request.len, data_size);
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errno = EINVAL;
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return -1;
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}
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if ((request.from + request.len) < request.from) {
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LOG("integer overflow detected! "
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"you're probably being attacked");
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errno = EINVAL;
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return -1;
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}
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if ((from + len) > size) {
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if ((request.from + request.len) > size) {
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LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
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", Offset: %" PRIu64 "\n",
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from, len, size, dev_offset);
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request.from, request.len, size, dev_offset);
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LOG("requested operation past EOF--bad client?");
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errno = EINVAL;
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return -1;
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}
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/* Reply
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[ 0 .. 3] magic (NBD_REPLY_MAGIC)
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[ 4 .. 7] error (0 == no error)
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[ 7 .. 15] handle
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*/
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cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
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cpu_to_be32w((uint32_t*)(buf + 4), 0);
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TRACE("Decoding type");
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switch (type) {
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case 0:
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reply.handle = request.handle;
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reply.error = 0;
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switch (request.type) {
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case NBD_CMD_READ:
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TRACE("Request type is READ");
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if (bdrv_read(bs, (from + dev_offset) / 512, data, len / 512) == -1) {
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if (bdrv_read(bs, (request.from + dev_offset) / 512, data,
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request.len / 512) == -1) {
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LOG("reading from file failed");
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errno = EINVAL;
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return -1;
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}
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*offset += len;
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*offset += request.len;
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TRACE("Read %u byte(s)", len);
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TRACE("Read %u byte(s)", request.len);
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TRACE("Sending OK response");
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if (write_sync(csock, buf, 16) != 16) {
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LOG("writing to socket failed");
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errno = EINVAL;
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if (nbd_send_reply(csock, &reply) == -1)
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return -1;
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}
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TRACE("Sending data to client");
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if (write_sync(csock, data, len) != len) {
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if (write_sync(csock, data, request.len) != request.len) {
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LOG("writing to socket failed");
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errno = EINVAL;
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return -1;
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}
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break;
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case 1:
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case NBD_CMD_WRITE:
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TRACE("Request type is WRITE");
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TRACE("Reading %u byte(s)", len);
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TRACE("Reading %u byte(s)", request.len);
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if (read_sync(csock, data, len) != len) {
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if (read_sync(csock, data, request.len) != request.len) {
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LOG("reading from socket failed");
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errno = EINVAL;
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return -1;
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@ -520,34 +600,29 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
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if (readonly) {
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TRACE("Server is read-only, return error");
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cpu_to_be32w((uint32_t*)(buf + 4), 1);
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reply.error = 1;
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} else {
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TRACE("Writing to device");
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if (bdrv_write(bs, (from + dev_offset) / 512, data, len / 512) == -1) {
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if (bdrv_write(bs, (request.from + dev_offset) / 512,
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data, request.len / 512) == -1) {
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LOG("writing to file failed");
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errno = EINVAL;
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return -1;
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}
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*offset += len;
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*offset += request.len;
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}
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TRACE("Sending response to client");
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if (write_sync(csock, buf, 16) != 16) {
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LOG("writing to socket failed");
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errno = EINVAL;
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if (nbd_send_reply(csock, &reply) == -1)
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return -1;
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}
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break;
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case 2:
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case NBD_CMD_DISC:
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TRACE("Request type is DISCONNECT");
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errno = 0;
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return 1;
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default:
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LOG("invalid request type (%u) received", type);
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LOG("invalid request type (%u) received", request.type);
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errno = EINVAL;
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return -1;
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}
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