Commit e6798f06 authored by Vladimir Sementsov-Ogievskiy's avatar Vladimir Sementsov-Ogievskiy Committed by Eric Blake
Browse files

nbd: generalize usage of nbd_read 



We generally do very similar things around nbd_read: error_prepend
specifying what we have tried to read, and be_to_cpu conversion of
integers.

So, it seems reasonable to move common things to helper functions,
which:
1. simplify code a bit
2. generalize nbd_read error descriptions, all starting with
   "Failed to read"
3. make it more difficult to forget to convert things from BE

Signed-off-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Message-Id: <20190128165830.165170-1-vsementsov@virtuozzo.com>
[eblake: rename macro to DEF_NBD_READ_N and formatting tweaks;
checkpatch has false positive complaint]
Signed-off-by: default avatarEric Blake <eblake@redhat.com>
parent 0ae2d546

block/nbd-client.c

+2 −3
Original line number Diff line number Diff line
@@ -338,10 +338,9 @@ static int nbd_co_receive_offset_data_payload(NBDClientSession *s, 
        return -EINVAL;

    }



    if (nbd_read(s->ioc, &offset, sizeof(offset), errp) < 0) {

    if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) {

        return -EIO;

    }

    be64_to_cpus(&offset);



    data_size = chunk->length - sizeof(offset);

    assert(data_size);
@@ -388,7 +387,7 @@ static coroutine_fn int nbd_co_receive_structured_payload( 
    }



    *payload = g_new(char, len);

    ret = nbd_read(s->ioc, *payload, len, errp);

    ret = nbd_read(s->ioc, *payload, len, "structured payload", errp);

    if (ret < 0) {

        g_free(*payload);

        *payload = NULL;

include/block/nbd.h

+30 −2
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include "qapi/qapi-types-block.h"

#include "io/channel-socket.h"

#include "crypto/tlscreds.h"

#include "qapi/error.h"



/* Handshake phase structs - this struct is passed on the wire */
@@ -336,11 +337,38 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, 
 * Reads @size bytes from @ioc. Returns 0 on success.

 */

static inline int nbd_read(QIOChannel *ioc, void *buffer, size_t size,

                           Error **errp)

                           const char *desc, Error **errp)

{

    return qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;

    int ret = qio_channel_read_all(ioc, buffer, size, errp) < 0 ? -EIO : 0;



    if (ret < 0) {

        if (desc) {

            error_prepend(errp, "Failed to read %s: ", desc);

        }

        return -1;

    }



    return 0;

}



#define DEF_NBD_READ_N(bits)                                            \

static inline int nbd_read##bits(QIOChannel *ioc,                       \

                                 uint##bits##_t *val,                   \

                                 const char *desc, Error **errp)        \

{                                                                       \

    if (nbd_read(ioc, val, sizeof(*val), desc, errp) < 0) {             \

        return -1;                                                      \

    }                                                                   \

    *val = be##bits##_to_cpu(*val);                                     \

    return 0;                                                           \

}



DEF_NBD_READ_N(16) /* Defines nbd_read16(). */

DEF_NBD_READ_N(32) /* Defines nbd_read32(). */

DEF_NBD_READ_N(64) /* Defines nbd_read64(). */



#undef DEF_NBD_READ_N



static inline bool nbd_reply_is_simple(NBDReply *reply)

{

    return reply->magic == NBD_SIMPLE_REPLY_MAGIC;

nbd/client.c

+29 −59
Original line number Diff line number Diff line
@@ -113,8 +113,7 @@ static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt, 
                                    NBDOptionReply *reply, Error **errp)

{

    QEMU_BUILD_BUG_ON(sizeof(*reply) != 20);

    if (nbd_read(ioc, reply, sizeof(*reply), errp) < 0) {

        error_prepend(errp, "failed to read option reply: ");

    if (nbd_read(ioc, reply, sizeof(*reply), "option reply", errp) < 0) {

        nbd_send_opt_abort(ioc);

        return -1;

    }
@@ -166,8 +165,8 @@ static int nbd_handle_reply_err(QIOChannel *ioc, NBDOptionReply *reply, 
            goto cleanup;

        }

        msg = g_malloc(reply->length + 1);

        if (nbd_read(ioc, msg, reply->length, errp) < 0) {

            error_prepend(errp, "failed to read option error %" PRIu32

        if (nbd_read(ioc, msg, reply->length, NULL, errp) < 0) {

            error_prepend(errp, "Failed to read option error %" PRIu32

                          " (%s) message: ",

                          reply->type, nbd_rep_lookup(reply->type));

            goto cleanup;
@@ -284,12 +283,10 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description, 
        nbd_send_opt_abort(ioc);

        return -1;

    }

    if (nbd_read(ioc, &namelen, sizeof(namelen), errp) < 0) {

        error_prepend(errp, "failed to read option name length: ");

    if (nbd_read32(ioc, &namelen, "option name length", errp) < 0) {

        nbd_send_opt_abort(ioc);

        return -1;

    }

    namelen = be32_to_cpu(namelen);

    len -= sizeof(namelen);

    if (len < namelen) {

        error_setg(errp, "incorrect option name length");
@@ -298,8 +295,7 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description, 
    }



    local_name = g_malloc(namelen + 1);

    if (nbd_read(ioc, local_name, namelen, errp) < 0) {

        error_prepend(errp, "failed to read export name: ");

    if (nbd_read(ioc, local_name, namelen, "export name", errp) < 0) {

        nbd_send_opt_abort(ioc);

        goto out;

    }
@@ -307,8 +303,7 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description, 
    len -= namelen;

    if (len) {

        local_desc = g_malloc(len + 1);

        if (nbd_read(ioc, local_desc, len, errp) < 0) {

            error_prepend(errp, "failed to read export description: ");

        if (nbd_read(ioc, local_desc, len, "export description", errp) < 0) {

            nbd_send_opt_abort(ioc);

            goto out;

        }
@@ -410,13 +405,11 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt, 
            nbd_send_opt_abort(ioc);

            return -1;

        }

        if (nbd_read(ioc, &type, sizeof(type), errp) < 0) {

            error_prepend(errp, "failed to read info type: ");

        if (nbd_read16(ioc, &type, "info type", errp) < 0) {

            nbd_send_opt_abort(ioc);

            return -1;

        }

        len -= sizeof(type);

        type = be16_to_cpu(type);

        switch (type) {

        case NBD_INFO_EXPORT:

            if (len != sizeof(info->size) + sizeof(info->flags)) {
@@ -425,18 +418,14 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt, 
                nbd_send_opt_abort(ioc);

                return -1;

            }

            if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {

                error_prepend(errp, "failed to read info size: ");

            if (nbd_read64(ioc, &info->size, "info size", errp) < 0) {

                nbd_send_opt_abort(ioc);

                return -1;

            }

            info->size = be64_to_cpu(info->size);

            if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {

                error_prepend(errp, "failed to read info flags: ");

            if (nbd_read16(ioc, &info->flags, "info flags", errp) < 0) {

                nbd_send_opt_abort(ioc);

                return -1;

            }

            info->flags = be16_to_cpu(info->flags);

            trace_nbd_receive_negotiate_size_flags(info->size, info->flags);

            break;
@@ -447,27 +436,23 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt, 
                nbd_send_opt_abort(ioc);

                return -1;

            }

            if (nbd_read(ioc, &info->min_block, sizeof(info->min_block),

            if (nbd_read32(ioc, &info->min_block, "info minimum block size",

                           errp) < 0) {

                error_prepend(errp, "failed to read info minimum block size: ");

                nbd_send_opt_abort(ioc);

                return -1;

            }

            info->min_block = be32_to_cpu(info->min_block);

            if (!is_power_of_2(info->min_block)) {

                error_setg(errp, "server minimum block size %" PRIu32

                           " is not a power of two", info->min_block);

                nbd_send_opt_abort(ioc);

                return -1;

            }

            if (nbd_read(ioc, &info->opt_block, sizeof(info->opt_block),

                         errp) < 0) {

                error_prepend(errp,

                              "failed to read info preferred block size: ");

            if (nbd_read32(ioc, &info->opt_block, "info preferred block size",

                           errp) < 0)

            {

                nbd_send_opt_abort(ioc);

                return -1;

            }

            info->opt_block = be32_to_cpu(info->opt_block);

            if (!is_power_of_2(info->opt_block) ||

                info->opt_block < info->min_block) {

                error_setg(errp, "server preferred block size %" PRIu32
@@ -475,13 +460,12 @@ static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt, 
                nbd_send_opt_abort(ioc);

                return -1;

            }

            if (nbd_read(ioc, &info->max_block, sizeof(info->max_block),

                         errp) < 0) {

                error_prepend(errp, "failed to read info maximum block size: ");

            if (nbd_read32(ioc, &info->max_block, "info maximum block size",

                           errp) < 0)

            {

                nbd_send_opt_abort(ioc);

                return -1;

            }

            info->max_block = be32_to_cpu(info->max_block);

            if (info->max_block < info->min_block) {

                error_setg(errp, "server maximum block size %" PRIu32

                           " is not valid", info->max_block);
@@ -731,14 +715,13 @@ static int nbd_receive_one_meta_context(QIOChannel *ioc, 
        return -1;

    }



    if (nbd_read(ioc, &local_id, sizeof(local_id), errp) < 0) {

    if (nbd_read32(ioc, &local_id, "context id", errp) < 0) {

        return -1;

    }

    local_id = be32_to_cpu(local_id);



    reply.length -= sizeof(local_id);

    local_name = g_malloc(reply.length + 1);

    if (nbd_read(ioc, local_name, reply.length, errp) < 0) {

    if (nbd_read(ioc, local_name, reply.length, "context name", errp) < 0) {

        g_free(local_name);

        return -1;

    }
@@ -896,11 +879,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
        return -EINVAL;

    }



    if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {

        error_prepend(errp, "Failed to read initial magic: ");

    if (nbd_read64(ioc, &magic, "initial magic", errp) < 0) {

        return -EINVAL;

    }

    magic = be64_to_cpu(magic);

    trace_nbd_receive_negotiate_magic(magic);



    if (magic != NBD_INIT_MAGIC) {
@@ -908,11 +889,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
        return -EINVAL;

    }



    if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {

        error_prepend(errp, "Failed to read server magic: ");

    if (nbd_read64(ioc, &magic, "server magic", errp) < 0) {

        return -EINVAL;

    }

    magic = be64_to_cpu(magic);

    trace_nbd_receive_negotiate_magic(magic);



    if (magic == NBD_OPTS_MAGIC) {
@@ -920,11 +899,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
        uint16_t globalflags;

        bool fixedNewStyle = false;



        if (nbd_read(ioc, &globalflags, sizeof(globalflags), errp) < 0) {

            error_prepend(errp, "Failed to read server flags: ");

        if (nbd_read16(ioc, &globalflags, "server flags", errp) < 0) {

            return -EINVAL;

        }

        globalflags = be16_to_cpu(globalflags);

        trace_nbd_receive_negotiate_server_flags(globalflags);

        if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {

            fixedNewStyle = true;
@@ -992,17 +969,13 @@ static int nbd_negotiate_finish_oldstyle(QIOChannel *ioc, NBDExportInfo *info, 
{

    uint32_t oldflags;



    if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {

        error_prepend(errp, "Failed to read export length: ");

    if (nbd_read64(ioc, &info->size, "export length", errp) < 0) {

        return -EINVAL;

    }

    info->size = be64_to_cpu(info->size);



    if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {

        error_prepend(errp, "Failed to read export flags: ");

    if (nbd_read32(ioc, &oldflags, "export flags", errp) < 0) {

        return -EINVAL;

    }

    oldflags = be32_to_cpu(oldflags);

    if (oldflags & ~0xffff) {

        error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);

        return -EINVAL;
@@ -1079,17 +1052,13 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
        }



        /* Read the response */

        if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {

            error_prepend(errp, "Failed to read export length: ");

        if (nbd_read64(ioc, &info->size, "export length", errp) < 0) {

            return -EINVAL;

        }

        info->size = be64_to_cpu(info->size);



        if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {

            error_prepend(errp, "Failed to read export flags: ");

        if (nbd_read16(ioc, &info->flags, "export flags", errp) < 0) {

            return -EINVAL;

        }

        info->flags = be16_to_cpu(info->flags);

        break;

    case 0: /* oldstyle, parse length and flags */

        if (*info->name) {
@@ -1379,7 +1348,7 @@ static int nbd_receive_simple_reply(QIOChannel *ioc, NBDSimpleReply *reply, 
    assert(reply->magic == NBD_SIMPLE_REPLY_MAGIC);



    ret = nbd_read(ioc, (uint8_t *)reply + sizeof(reply->magic),

                   sizeof(*reply) - sizeof(reply->magic), errp);

                   sizeof(*reply) - sizeof(reply->magic), "reply", errp);

    if (ret < 0) {

        return ret;

    }
@@ -1404,7 +1373,8 @@ static int nbd_receive_structured_reply_chunk(QIOChannel *ioc, 
    assert(chunk->magic == NBD_STRUCTURED_REPLY_MAGIC);



    ret = nbd_read(ioc, (uint8_t *)chunk + sizeof(chunk->magic),

                   sizeof(*chunk) - sizeof(chunk->magic), errp);

                   sizeof(*chunk) - sizeof(chunk->magic), "structured chunk",

                   errp);

    if (ret < 0) {

        return ret;

    }

nbd/common.c

+1 −1
Original line number Diff line number Diff line
@@ -31,7 +31,7 @@ int nbd_drop(QIOChannel *ioc, size_t size, Error **errp) 
    buffer = sizeof(small) >= size ? small : g_malloc(MIN(65536, size));

    while (size > 0) {

        ssize_t count = MIN(65536, size);

        ret = nbd_read(ioc, buffer, MIN(65536, size), errp);

        ret = nbd_read(ioc, buffer, MIN(65536, size), NULL, errp);



        if (ret < 0) {

            goto cleanup;

nbd/server.c

+9 −18
Original line number Diff line number Diff line
@@ -438,8 +438,7 @@ static int nbd_negotiate_handle_export_name(NBDClient *client, 
        error_setg(errp, "Bad length received");

        return -EINVAL;

    }

    if (nbd_read(client->ioc, name, client->optlen, errp) < 0) {

        error_prepend(errp, "read failed: ");

    if (nbd_read(client->ioc, name, client->optlen, "export name", errp) < 0) {

        return -EIO;

    }

    name[client->optlen] = '\0';
@@ -1046,11 +1045,9 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, 
        ...           Rest of request

    */



    if (nbd_read(client->ioc, &flags, sizeof(flags), errp) < 0) {

        error_prepend(errp, "read failed: ");

    if (nbd_read32(client->ioc, &flags, "flags", errp) < 0) {

        return -EIO;

    }

    flags = be32_to_cpu(flags);

    trace_nbd_negotiate_options_flags(flags);

    if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) {

        fixedNewstyle = true;
@@ -1070,30 +1067,23 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, 
        uint32_t option, length;

        uint64_t magic;



        if (nbd_read(client->ioc, &magic, sizeof(magic), errp) < 0) {

            error_prepend(errp, "read failed: ");

        if (nbd_read64(client->ioc, &magic, "opts magic", errp) < 0) {

            return -EINVAL;

        }

        magic = be64_to_cpu(magic);

        trace_nbd_negotiate_options_check_magic(magic);

        if (magic != NBD_OPTS_MAGIC) {

            error_setg(errp, "Bad magic received");

            return -EINVAL;

        }



        if (nbd_read(client->ioc, &option,

                     sizeof(option), errp) < 0) {

            error_prepend(errp, "read failed: ");

        if (nbd_read32(client->ioc, &option, "option", errp) < 0) {

            return -EINVAL;

        }

        option = be32_to_cpu(option);

        client->opt = option;



        if (nbd_read(client->ioc, &length, sizeof(length), errp) < 0) {

            error_prepend(errp, "read failed: ");

        if (nbd_read32(client->ioc, &length, "option length", errp) < 0) {

            return -EINVAL;

        }

        length = be32_to_cpu(length);

        assert(!client->optlen);

        client->optlen = length;
@@ -1306,7 +1296,7 @@ static int nbd_receive_request(QIOChannel *ioc, NBDRequest *request, 
    uint32_t magic;

    int ret;



    ret = nbd_read(ioc, buf, sizeof(buf), errp);

    ret = nbd_read(ioc, buf, sizeof(buf), "request", errp);

    if (ret < 0) {

        return ret;

    }
@@ -2111,8 +2101,9 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, 
        }

    }

    if (request->type == NBD_CMD_WRITE) {

        if (nbd_read(client->ioc, req->data, request->len, errp) < 0) {

            error_prepend(errp, "reading from socket failed: ");

        if (nbd_read(client->ioc, req->data, request->len, "CMD_WRITE data",

                     errp) < 0)

        {

            return -EIO;

        }

        req->complete = true;