nbd: Split nbd.c

We have NBD server code and client code, all mixed in a file. Now split
them into separate files under nbd/, and update MAINTAINERS.

filter_nbd for iotest 083 is updated to keep the log filtered out.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <1452760863-25350-3-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

MAINTAINERS

@@ -1116,8 +1116,9 @@ F: net/netmap.c
 Network Block Device (NBD)
 M: Paolo Bonzini <pbonzini@redhat.com>
 S: Odd Fixes
-F: block/nbd.c
-F: nbd.*
+F: block/nbd*
+F: nbd/
+F: include/block/nbd*
 F: qemu-nbd.c
 T: git git://github.com/bonzini/qemu.git nbd-next
 

Makefile.objs

@@ -8,7 +8,8 @@ util-obj-y += qmp-introspect.o qapi-types.o qapi-visit.o qapi-event.o
 # block-obj-y is code used by both qemu system emulation and qemu-img
 
 block-obj-y = async.o thread-pool.o
-block-obj-y += nbd.o block.o blockjob.o
+block-obj-y += nbd/
+block-obj-y += block.o blockjob.o
 block-obj-y += main-loop.o iohandler.o qemu-timer.o
 block-obj-$(CONFIG_POSIX) += aio-posix.o
 block-obj-$(CONFIG_WIN32) += aio-win32.o

nbd/Makefile.objs

+block-obj-y += server.o client.o common.o

nbd/client.c

+/*
+ *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
+ *
+ *  Network Block Device Client Side
+ *
+ *  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-internal.h"
+
+static int nbd_errno_to_system_errno(int err)
+{
+    switch (err) {
+    case NBD_SUCCESS:
+        return 0;
+    case NBD_EPERM:
+        return EPERM;
+    case NBD_EIO:
+        return EIO;
+    case NBD_ENOMEM:
+        return ENOMEM;
+    case NBD_ENOSPC:
+        return ENOSPC;
+    case NBD_EINVAL:
+    default:
+        return EINVAL;
+    }
+}
+
+/* Definitions for opaque data types */
+
+static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
+
+/* That's all folks */
+
+/* Basic flow for negotiation
+
+   Server         Client
+   Negotiate
+
+   or
+
+   Server         Client
+   Negotiate #1
+                  Option
+   Negotiate #2
+
+   ----
+
+   followed by
+
+   Server         Client
+                  Request
+   Response
+                  Request
+   Response
+                  ...
+   ...
+                  Request (type == 2)
+
+*/
+
+int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
+                          off_t *size, Error **errp)
+{
+    char buf[256];
+    uint64_t magic, s;
+    uint16_t tmp;
+    int rc;
+
+    TRACE("Receiving negotiation.");
+
+    rc = -EINVAL;
+
+    if (read_sync(csock, buf, 8) != 8) {
+        error_setg(errp, "Failed to read data");
+        goto fail;
+    }
+
+    buf[8] = '\0';
+    if (strlen(buf) == 0) {
+        error_setg(errp, "Server connection closed unexpectedly");
+        goto fail;
+    }
+
+    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) {
+        error_setg(errp, "Invalid magic received");
+        goto fail;
+    }
+
+    if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+        error_setg(errp, "Failed to read magic");
+        goto fail;
+    }
+    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 != NBD_OPTS_MAGIC) {
+            if (magic == NBD_CLIENT_MAGIC) {
+                error_setg(errp, "Server does not support export names");
+            } else {
+                error_setg(errp, "Bad magic received");
+            }
+            goto fail;
+        }
+        if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+            error_setg(errp, "Failed to read server flags");
+            goto fail;
+        }
+        *flags = be16_to_cpu(tmp) << 16;
+        /* reserved for future use */
+        if (write_sync(csock, &reserved, sizeof(reserved)) !=
+            sizeof(reserved)) {
+            error_setg(errp, "Failed to read reserved field");
+            goto fail;
+        }
+        /* write the export name */
+        magic = cpu_to_be64(magic);
+        if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+            error_setg(errp, "Failed to send export name magic");
+            goto fail;
+        }
+        opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
+        if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
+            error_setg(errp, "Failed to send export name option number");
+            goto fail;
+        }
+        namesize = cpu_to_be32(strlen(name));
+        if (write_sync(csock, &namesize, sizeof(namesize)) !=
+            sizeof(namesize)) {
+            error_setg(errp, "Failed to send export name length");
+            goto fail;
+        }
+        if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
+            error_setg(errp, "Failed to send export name");
+            goto fail;
+        }
+    } else {
+        TRACE("Checking magic (cli_magic)");
+
+        if (magic != NBD_CLIENT_MAGIC) {
+            if (magic == NBD_OPTS_MAGIC) {
+                error_setg(errp, "Server requires an export name");
+            } else {
+                error_setg(errp, "Bad magic received");
+            }
+            goto fail;
+        }
+    }
+
+    if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) {
+        error_setg(errp, "Failed to read export length");
+        goto fail;
+    }
+    *size = be64_to_cpu(s);
+    TRACE("Size is %" PRIu64, *size);
+
+    if (!name) {
+        if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) {
+            error_setg(errp, "Failed to read export flags");
+            goto fail;
+        }
+        *flags = be32_to_cpup(flags);
+    } else {
+        if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+            error_setg(errp, "Failed to read export flags");
+            goto fail;
+        }
+        *flags |= be16_to_cpu(tmp);
+    }
+    if (read_sync(csock, &buf, 124) != 124) {
+        error_setg(errp, "Failed to read reserved block");
+        goto fail;
+    }
+    rc = 0;
+
+fail:
+    return rc;
+}
+
+#ifdef __linux__
+int nbd_init(int fd, int csock, uint32_t flags, off_t size)
+{
+    TRACE("Setting NBD socket");
+
+    if (ioctl(fd, NBD_SET_SOCK, csock) < 0) {
+        int serrno = errno;
+        LOG("Failed to set NBD socket");
+        return -serrno;
+    }
+
+    TRACE("Setting block size to %lu", (unsigned long)BDRV_SECTOR_SIZE);
+
+    if (ioctl(fd, NBD_SET_BLKSIZE, (size_t)BDRV_SECTOR_SIZE) < 0) {
+        int serrno = errno;
+        LOG("Failed setting NBD block size");
+        return -serrno;
+    }
+
+    TRACE("Setting size to %zd block(s)", (size_t)(size / BDRV_SECTOR_SIZE));
+
+    if (ioctl(fd, NBD_SET_SIZE_BLOCKS, (size_t)(size / BDRV_SECTOR_SIZE)) < 0) {
+        int serrno = errno;
+        LOG("Failed setting size (in blocks)");
+        return -serrno;
+    }
+
+    if (ioctl(fd, NBD_SET_FLAGS, flags) < 0) {
+        if (errno == ENOTTY) {
+            int read_only = (flags & NBD_FLAG_READ_ONLY) != 0;
+            TRACE("Setting readonly attribute");
+
+            if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
+                int serrno = errno;
+                LOG("Failed setting read-only attribute");
+                return -serrno;
+            }
+        } else {
+            int serrno = errno;
+            LOG("Failed setting flags");
+            return -serrno;
+        }
+    }
+
+    TRACE("Negotiation ended");
+
+    return 0;
+}
+
+int nbd_client(int fd)
+{
+    int ret;
+    int serrno;
+
+    TRACE("Doing NBD loop");
+
+    ret = ioctl(fd, NBD_DO_IT);
+    if (ret < 0 && errno == EPIPE) {
+        /* NBD_DO_IT normally returns EPIPE when someone has disconnected
+         * the socket via NBD_DISCONNECT.  We do not want to return 1 in
+         * that case.
+         */
+        ret = 0;
+    }
+    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, uint32_t flags, off_t size)
+{
+    return -ENOTSUP;
+}
+
+int nbd_client(int fd)
+{
+    return -ENOTSUP;
+}
+#endif
+
+ssize_t nbd_send_request(int csock, struct nbd_request *request)
+{
+    uint8_t buf[NBD_REQUEST_SIZE];
+    ssize_t ret;
+
+    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);
+
+    ret = write_sync(csock, buf, sizeof(buf));
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (ret != sizeof(buf)) {
+        LOG("writing to socket failed");
+        return -EINVAL;
+    }
+    return 0;
+}
+
+ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply)
+{
+    uint8_t buf[NBD_REPLY_SIZE];
+    uint32_t magic;
+    ssize_t ret;
+
+    ret = read_sync(csock, buf, sizeof(buf));
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (ret != sizeof(buf)) {
+        LOG("read failed");
+        return -EINVAL;
+    }
+
+    /* 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));
+
+    reply->error = nbd_errno_to_system_errno(reply->error);
+
+    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);
+        return -EINVAL;
+    }
+    return 0;
+}
+

nbd/common.c

+/*
+ *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
+ *
+ *  Network Block Device Common Code
+ *
+ *  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-internal.h"
+
+ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
+{
+    size_t offset = 0;
+    int err;
+
+    if (qemu_in_coroutine()) {
+        if (do_read) {
+            return qemu_co_recv(fd, buffer, size);
+        } else {
+            return qemu_co_send(fd, buffer, size);
+        }
+    }
+
+    while (offset < size) {
+        ssize_t len;
+
+        if (do_read) {
+            len = qemu_recv(fd, buffer + offset, size - offset, 0);
+        } else {
+            len = send(fd, buffer + offset, size - offset, 0);
+        }
+
+        if (len < 0) {
+            err = socket_error();
+
+            /* recoverable error */
+            if (err == EINTR || (offset > 0 && (err == EAGAIN || err == EWOULDBLOCK))) {
+                continue;
+            }
+
+            /* unrecoverable error */
+            return -err;
+        }
+
+        /* eof */
+        if (len == 0) {
+            break;
+        }
+
+        offset += len;
+    }
+
+    return offset;
+}

nbd/nbd-internal.h

+/*
+ * NBD Internal Declarations
+ *
+ * Copyright (C) 2016 Red Hat, Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef NBD_INTERNAL_H
+#define NBD_INTERNAL_H
+#include "block/nbd.h"
+#include "sysemu/block-backend.h"
+
+#include "qemu/coroutine.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>
+
+#ifdef __linux__
+#include <linux/fs.h>
+#endif
+
+#include "qemu/sockets.h"
+#include "qemu/queue.h"
+#include "qemu/main-loop.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.
+ *
+ * The most up-to-date documentation is available at:
+ * https://github.com/yoe/nbd/blob/master/doc/proto.txt
+ */
+
+#define NBD_REQUEST_SIZE        (4 + 4 + 8 + 8 + 4)
+#define NBD_REPLY_SIZE          (4 + 4 + 8)
+#define NBD_REQUEST_MAGIC       0x25609513
+#define NBD_REPLY_MAGIC         0x67446698
+#define NBD_OPTS_MAGIC          0x49484156454F5054LL
+#define NBD_CLIENT_MAGIC        0x0000420281861253LL
+#define NBD_REP_MAGIC           0x3e889045565a9LL
+
+#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_SET_TIMEOUT         _IO(0xab, 9)
+#define NBD_SET_FLAGS           _IO(0xab, 10)
+
+#define NBD_OPT_EXPORT_NAME     (1)
+#define NBD_OPT_ABORT           (2)
+#define NBD_OPT_LIST            (3)
+
+/* NBD errors are based on errno numbers, so there is a 1:1 mapping,
+ * but only a limited set of errno values is specified in the protocol.
+ * Everything else is squashed to EINVAL.
+ */
+#define NBD_SUCCESS    0
+#define NBD_EPERM      1
+#define NBD_EIO        5
+#define NBD_ENOMEM     12
+#define NBD_EINVAL     22
+#define NBD_ENOSPC     28
+
+static inline ssize_t read_sync(int fd, void *buffer, size_t size)
+{
+    /* Sockets are kept in blocking mode in the negotiation phase.  After
+     * that, a non-readable socket simply means that another thread stole
+     * our request/reply.  Synchronization is done with recv_coroutine, so
+     * that this is coroutine-safe.
+     */
+    return nbd_wr_sync(fd, buffer, size, true);
+}
+
+static inline ssize_t write_sync(int fd, void *buffer, size_t size)
+{
+    int ret;
+    do {
+        /* For writes, we do expect the socket to be writable.  */
+        ret = nbd_wr_sync(fd, buffer, size, false);
+    } while (ret == -EAGAIN);
+    return ret;
+}
+
+#endif

tests/qemu-iotests/083

@@ -55,7 +55,7 @@ filter_nbd() {
 	# callbacks sometimes, making them unreliable.
 	#
 	# Filter out the TCP port number since this changes between runs.
-	sed -e 's#^.*nbd\.c:.*##g' \
+	sed -e 's#^.*nbd/.*\.c:.*##g' \
 	    -e 's#nbd:127\.0\.0\.1:[^:]*:#nbd:127\.0\.0\.1:PORT:#g' \
             -e 's#\(exportname=foo\|PORT\): Failed to .*$#\1#'
 }