Commit 526e5c65 authored by Eric Blake's avatar Eric Blake Committed by Paolo Bonzini
Browse files

nbd: Share common reply-sending code in server 



Rather than open-coding NBD_REP_SERVER, reuse the code we
already have by adding a length parameter.  Additionally,
the refactoring will make adding NBD_OPT_GO in a later patch
easier.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Message-Id: <1476469998-28592-7-git-send-email-eblake@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent ed2dd912

nbd/server.c

+27 −25
Original line number Diff line number Diff line
@@ -196,12 +196,15 @@ static ssize_t nbd_negotiate_drop_sync(QIOChannel *ioc, size_t size) 


*/



static int nbd_negotiate_send_rep(QIOChannel *ioc, uint32_t type, uint32_t opt)

/* Send a reply header, including length, but no payload.

 * Return -errno on error, 0 on success. */

static int nbd_negotiate_send_rep_len(QIOChannel *ioc, uint32_t type,

                                      uint32_t opt, uint32_t len)

{

    uint64_t magic;

    uint32_t len;



    TRACE("Reply opt=%" PRIx32 " type=%" PRIx32, type, opt);

    TRACE("Reply opt=%" PRIx32 " type=%" PRIx32 " len=%" PRIu32,

          type, opt, len);



    magic = cpu_to_be64(NBD_REP_MAGIC);

    if (nbd_negotiate_write(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
@@ -218,7 +221,7 @@ static int nbd_negotiate_send_rep(QIOChannel *ioc, uint32_t type, uint32_t opt) 
        LOG("write failed (rep type)");

        return -EINVAL;

    }

    len = cpu_to_be32(0);

    len = cpu_to_be32(len);

    if (nbd_negotiate_write(ioc, &len, sizeof(len)) != sizeof(len)) {

        LOG("write failed (rep data length)");

        return -EINVAL;
@@ -226,37 +229,32 @@ static int nbd_negotiate_send_rep(QIOChannel *ioc, uint32_t type, uint32_t opt) 
    return 0;

}



/* Send a reply header with default 0 length.

 * Return -errno on error, 0 on success. */

static int nbd_negotiate_send_rep(QIOChannel *ioc, uint32_t type, uint32_t opt)

{

    return nbd_negotiate_send_rep_len(ioc, type, opt, 0);

}



/* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.

 * Return -errno on error, 0 on success. */

static int nbd_negotiate_send_rep_list(QIOChannel *ioc, NBDExport *exp)

{

    uint64_t magic;

    size_t name_len, desc_len;

    uint32_t opt, type, len;

    uint32_t len;

    const char *name = exp->name ? exp->name : "";

    const char *desc = exp->description ? exp->description : "";

    int rc;



    TRACE("Advertising export name '%s' description '%s'", name, desc);

    name_len = strlen(name);

    desc_len = strlen(desc);

    magic = cpu_to_be64(NBD_REP_MAGIC);

    if (nbd_negotiate_write(ioc, &magic, sizeof(magic)) != sizeof(magic)) {

        LOG("write failed (magic)");

        return -EINVAL;

     }

    opt = cpu_to_be32(NBD_OPT_LIST);

    if (nbd_negotiate_write(ioc, &opt, sizeof(opt)) != sizeof(opt)) {

        LOG("write failed (opt)");

        return -EINVAL;

    }

    type = cpu_to_be32(NBD_REP_SERVER);

    if (nbd_negotiate_write(ioc, &type, sizeof(type)) != sizeof(type)) {

        LOG("write failed (reply type)");

        return -EINVAL;

    }

    len = cpu_to_be32(name_len + desc_len + sizeof(len));

    if (nbd_negotiate_write(ioc, &len, sizeof(len)) != sizeof(len)) {

        LOG("write failed (length)");

        return -EINVAL;

    len = name_len + desc_len + sizeof(len);

    rc = nbd_negotiate_send_rep_len(ioc, NBD_REP_SERVER, NBD_OPT_LIST, len);

    if (rc < 0) {

        return rc;

    }



    len = cpu_to_be32(name_len);

    if (nbd_negotiate_write(ioc, &len, sizeof(len)) != sizeof(len)) {

        LOG("write failed (name length)");
@@ -273,6 +271,8 @@ static int nbd_negotiate_send_rep_list(QIOChannel *ioc, NBDExport *exp) 
    return 0;

}



/* Process the NBD_OPT_LIST command, with a potential series of replies.

 * Return -errno on error, 0 on success. */

static int nbd_negotiate_handle_list(NBDClient *client, uint32_t length)

{

    NBDExport *exp;
@@ -382,6 +382,8 @@ static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client, 
}





/* Process all NBD_OPT_* client option commands.

 * Return -errno on error, 0 on success. */

static int nbd_negotiate_options(NBDClient *client)

{

    uint32_t flags;