From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35195) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wrn1L-0001Tt-6i for qemu-devel@nongnu.org; Tue, 03 Jun 2014 07:36:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wrn1F-0007xq-5K for qemu-devel@nongnu.org; Tue, 03 Jun 2014 07:36:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:18840) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wrn1E-0007x2-Se for qemu-devel@nongnu.org; Tue, 03 Jun 2014 07:36:41 -0400 Message-ID: <538DB343.1060006@redhat.com> Date: Tue, 03 Jun 2014 13:36:35 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1401572382-11667-1-git-send-email-kroosec@gmail.com> <1401572382-11667-3-git-send-email-kroosec@gmail.com> In-Reply-To: <1401572382-11667-3-git-send-email-kroosec@gmail.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/3] nbd: Add exports listing support. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Hani Benhabiles , qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, stefanha@redhat.com, mreitz@redhat.com Il 31/05/2014 23:39, Hani Benhabiles ha scritto: > This is added by handling the NBD_OPT_LIST and NBD_OPT_ABORT options. > > NBD_REP_ERR_UNSUP is also sent for unknown NBD option values. > > Signed-off-by: Hani Benhabiles > --- > include/block/nbd.h | 5 ++ > nbd.c | 197 +++++++++++++++++++++++++++++++++++++++++----------- > 2 files changed, 162 insertions(+), 40 deletions(-) > > diff --git a/include/block/nbd.h b/include/block/nbd.h > index 95d52ab..fd7e057 100644 > --- a/include/block/nbd.h > +++ b/include/block/nbd.h > @@ -51,6 +51,11 @@ struct nbd_reply { > /* New-style client flags. */ > #define NBD_FLAG_C_FIXED_NEWSTYLE (1 << 0) /* Fixed newstyle protocol. */ > > +/* Reply types. */ > +#define NBD_REP_ACK (1) /* Data sending finished. */ > +#define NBD_REP_SERVER (2) /* Export description. */ > +#define NBD_REP_ERR_UNSUP ((1 << 31) | 1) /* Unknown option. */ > + > #define NBD_CMD_MASK_COMMAND 0x0000ffff > #define NBD_CMD_FLAG_FUA (1 << 16) > > diff --git a/nbd.c b/nbd.c > index aa2e552..012e5da 100644 > --- a/nbd.c > +++ b/nbd.c > @@ -64,6 +64,7 @@ > #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) > @@ -77,7 +78,9 @@ > #define NBD_SET_TIMEOUT _IO(0xab, 9) > #define NBD_SET_FLAGS _IO(0xab, 10) > > -#define NBD_OPT_EXPORT_NAME (1 << 0) > +#define NBD_OPT_EXPORT_NAME (1) > +#define NBD_OPT_ABORT (2) > +#define NBD_OPT_LIST (3) > > /* Definitions for opaque data types */ > > @@ -215,54 +218,98 @@ static ssize_t write_sync(int fd, void *buffer, size_t size) > > */ > > -static int nbd_receive_options(NBDClient *client) > +static int nbd_send_rep(int csock, uint32_t type, uint32_t opt) > { > - int csock = client->sock; > - char name[256]; > - uint32_t tmp, length; > uint64_t magic; > - int rc; > - > - /* Client sends: > - [ 0 .. 3] client flags > - [ 4 .. 11] NBD_OPTS_MAGIC > - [12 .. 15] NBD_OPT_EXPORT_NAME > - [16 .. 19] length > - [20 .. xx] export name (length bytes) > - */ > + uint32_t len; > > - rc = -EINVAL; > - if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { > - LOG("read failed"); > - goto fail; > + magic = cpu_to_be64(NBD_REP_MAGIC); > + if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { > + LOG("write failed (rep magic)"); > + return -EINVAL; > } > - TRACE("Checking client flags"); > - tmp = be32_to_cpu(tmp); > - if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) { > - LOG("Bad client flags received"); > - goto fail; > + opt = cpu_to_be32(opt); > + if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { > + LOG("write failed (rep opt)"); > + return -EINVAL; > } > - > - if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { > - LOG("read failed"); > - goto fail; > + type = cpu_to_be32(type); > + if (write_sync(csock, &type, sizeof(type)) != sizeof(type)) { > + LOG("write failed (rep type)"); > + return -EINVAL; > } > - TRACE("Checking opts magic"); > - if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) { > - LOG("Bad magic received"); > - goto fail; > + len = cpu_to_be32(0); > + if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) { > + LOG("write failed (rep data length)"); > + return -EINVAL; > } > + return 0; > +} > > - if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { > - LOG("read failed"); > - goto fail; > +static int nbd_send_rep_list(int csock, NBDExport *exp) > +{ > + uint64_t magic, name_len; > + uint32_t opt, type, len; > + > + name_len = strlen(exp->name); > + magic = cpu_to_be64(NBD_REP_MAGIC); > + if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { > + LOG("write failed (magic)"); > + return -EINVAL; > } > - TRACE("Checking option"); > - if (tmp != be32_to_cpu(NBD_OPT_EXPORT_NAME)) { > - LOG("Bad option received"); > - goto fail; > + opt = cpu_to_be32(NBD_OPT_LIST); > + if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { > + LOG("write failed (opt)"); > + return -EINVAL; > + } > + type = cpu_to_be32(NBD_REP_SERVER); > + if (write_sync(csock, &type, sizeof(type)) != sizeof(type)) { > + LOG("write failed (reply type)"); > + return -EINVAL; > + } > + len = cpu_to_be32(name_len + sizeof(len)); > + if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) { > + LOG("write failed (length)"); > + return -EINVAL; > + } > + len = cpu_to_be32(name_len); > + if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) { > + LOG("write failed (length)"); > + return -EINVAL; > + } > + if (write_sync(csock, exp->name, name_len) != name_len) { > + LOG("write failed (buffer)"); > + return -EINVAL; > + } > + return 0; > +} > + > +static int nbd_send_list(NBDClient *client) > +{ > + int csock; > + NBDExport *exp; > + > + csock = client->sock; > + /* For each export, send a NBD_REP_SERVER reply. */ > + QTAILQ_FOREACH(exp, &exports, next) { > + if (nbd_send_rep_list(csock, exp)) { > + return -EINVAL; > + } > } > + /* Finish with a NBD_REP_ACK. */ > + return nbd_send_rep(csock, NBD_REP_ACK, NBD_OPT_LIST); > +} > + > +static int nbd_handle_export_name(NBDClient *client) > +{ > + int rc = -EINVAL, csock = client->sock; > + char name[256]; > + uint32_t length; > > + /* Client sends: > + [16 .. 19] length > + [20 .. xx] export name (length bytes) > + */ > if (read_sync(csock, &length, sizeof(length)) != sizeof(length)) { > LOG("read failed"); > goto fail; > @@ -287,8 +334,76 @@ static int nbd_receive_options(NBDClient *client) > > QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); > nbd_export_get(client->exp); > + rc = 0; > +fail: > + return rc; > +} > + > +static int nbd_receive_options(NBDClient *client) > +{ > + int rc = -EINVAL; > > - TRACE("Option negotiation succeeded."); > + while (1) { > + int csock = client->sock; > + uint32_t tmp; > + uint64_t magic; > + > + /* Client sends: > + [ 0 .. 3] client flags > + [ 4 .. 11] NBD_OPTS_MAGIC > + [12 .. 15] NBD option > + ... Rest of request > + */ > + > + if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { > + LOG("read failed"); > + goto fail; > + } > + TRACE("Checking client flags"); > + tmp = be32_to_cpu(tmp); > + if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) { > + LOG("Bad client flags received"); > + goto fail; > + } > + > + if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { > + LOG("read failed"); > + goto fail; > + } > + TRACE("Checking opts magic"); > + if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) { > + LOG("Bad magic received"); > + goto fail; > + } > + > + if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { > + LOG("read failed"); > + goto fail; > + } > + > + TRACE("Checking option"); > + switch (be32_to_cpu(tmp)) { > + case NBD_OPT_LIST: > + if (nbd_send_list(client) < 0) { > + return -EINVAL; > + } > + break; You can just do "return nbd_send_list(client);" here. You probably should also rename the function to nbd_handle_list. > + case NBD_OPT_ABORT: > + return 1; > + > + case NBD_OPT_EXPORT_NAME: > + return nbd_handle_export_name(client); Part of this patch belongs in patch 1. This one should only add nbd_send_rep_list, nbd_handle_list and the NBD_OPT_LIST case. Paolo > + default: > + tmp = be32_to_cpu(tmp); > + LOG("Unsupported option 0x%x", tmp); > + if (nbd_send_rep(client->sock, NBD_REP_ERR_UNSUP, tmp)) { > + return -EINVAL; > + } > + return 1; > + } > + } > rc = 0; > fail: > return rc; > @@ -351,6 +466,8 @@ static int nbd_send_negotiate(NBDClient *client) > if (rc < 0) { > LOG("option negotiation failed"); > goto fail; > + } else if (rc > 0) { > + goto fail; > } > > assert ((client->exp->nbdflags & ~65535) == 0); > @@ -1175,7 +1292,7 @@ NBDClient *nbd_client_new(NBDExport *exp, int csock, > client->refcount = 1; > client->exp = exp; > client->sock = csock; > - if (nbd_send_negotiate(client) < 0) { > + if (nbd_send_negotiate(client)) { > g_free(client); > return NULL; > } >