search for: nbd_simple_reply_magic

...st { uint32_t count; /* Request length. */ } __attribute__((packed)); -/* Reply (server -> client). */ -struct reply { - uint32_t magic; /* NBD_REPLY_MAGIC. */ +/* Simple reply (server -> client). */ +struct simple_reply { + uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC. */ uint32_t error; /* NBD_SUCCESS or one of NBD_E*. */ uint64_t handle; /* Opaque handle. */ } __attribute__((packed)); -#define NBD_REQUEST_MAGIC 0x25609513 -#define NBD_REPLY_MAGIC 0x67446698 +/* Structured reply (server -> client). */ +struct structured_re...

.../* Opaque handle. */ uint64_t offset; /* Request offset. */ uint32_t count; /* Request length. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Simple reply (server -> client). */ struct nbd_simple_reply { uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC. */ uint32_t error; /* NBD_SUCCESS or one of NBD_E*. */ uint64_t handle; /* Opaque handle. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Structured reply (server -> client). */ struct nbd_structured_reply { @@ -187,23 +193,23 @@ struct nbd_struct...

...read or memset on structured read */ *fd = -1; - if (read_full (h->fd, &rep, sizeof rep) < 0) + /* magic and handle overlap between simple and structured replies */ + if (read_full (h->fd, &rep, sizeof rep.simple)) return nbd_mark_dead (h); - if (be32toh (rep.magic) != NBD_SIMPLE_REPLY_MAGIC) + switch (be32toh (rep.simple.magic)) { + case NBD_SIMPLE_REPLY_MAGIC: + nbdkit_debug ("received simple reply for cookie %#" PRIx64 ", status %s", + rep.simple.handle, + name_of_nbd_error(be32toh (rep.simple.error))); + error = be32toh...

.../* Opaque handle. */ uint64_t offset; /* Request offset. */ uint32_t count; /* Request length. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Simple reply (server -> client). */ struct nbd_simple_reply { uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC. */ uint32_t error; /* NBD_SUCCESS or one of NBD_E*. */ uint64_t handle; /* Opaque handle. */ -} __attribute__((packed)); +} NBD_ATTRIBUTE_PACKED; /* Structured reply (server -> client). */ struct nbd_structured_reply { @@ -193,23 +193,23 @@ struct nbd_struct...

...C`) C: 16 bits, command flags C: 16 bits, type -C: 64 bits, handle +C: 64 bits, cookie C: 64 bits, offset (unsigned) C: 32 bits, length (unsigned) C: (*length* bytes of data if the request is of type `NBD_CMD_WRITE`) @@ -366,7 +366,7 @@ follows: S: 32 bits, 0x67446698, magic (`NBD_SIMPLE_REPLY_MAGIC`; used to be `NBD_REPLY_MAGIC`) S: 32 bits, error (MAY be zero) -S: 64 bits, handle +S: 64 bits, cookie S: (*length* bytes of data if the request is of type `NBD_CMD_READ` and *error* is zero) @@ -381,7 +381,7 @@ server must initiate a hard disconnect). Second, there is no wa...

...rror) return NBD_ESHUTDOWN; #endif case EOVERFLOW: - return NBD_EOVERFLOW; + if (flag_df) + return NBD_EOVERFLOW; + /* fallthrough */ case EINVAL: default: return NBD_EINVAL; @@ -368,7 +370,7 @@ send_simple_reply (struct connection *conn, reply.magic = htobe32 (NBD_SIMPLE_REPLY_MAGIC); reply.handle = handle; - reply.error = htobe32 (nbd_errno (error)); + reply.error = htobe32 (nbd_errno (error, false)); r = conn->send (conn, &reply, sizeof reply); if (r == -1) { @@ -573,7 +575,8 @@ send_structured_reply_block_status (struct connection *conn, static int sen...

I'm hoping to implement .extents for the nbd plugin; this is a prerequisite. I'm not sure about patch 3 - if we like it, I'll squash it to 2, if we don't, I think we are okay just dropping it. I'm also wondering if we have to worry about malicious plugins that don't populate the entire .pread buffer in an effort to get nbdkit to expose portions of the heap; my patch 7 loses

Updated based on other changes that have happened in the meantime: - rely more on cleanup.h (throughout) - split structured read for easier review (patch 2 and 3 were combined in v1) - rely on nbdkit not leaking a server's partial answer (patch 3) - add tests (patch 5) - other bug fixes I found while testing it - drop EOVERFLOW patch for now; it will be separate once upstream NBD protocol

...buf; > uint32_t count; > @@ -353,7 +353,7 @@ nbd_reply_raw (struct handle *h, int *fd) > *fd = -1; > if (read_full (h->fd, &rep, sizeof rep) < 0) > return nbd_mark_dead (h); > - if (be32toh (rep.magic) != NBD_REPLY_MAGIC) > + if (be32toh (rep.magic) != NBD_SIMPLE_REPLY_MAGIC) > return nbd_mark_dead (h); > nbdkit_debug ("received reply for cookie %#" PRIx64 ", status %s", > rep.handle, name_of_nbd_error(be32toh (rep.error))); Teaching the nbd plugin to negotiate structured replies as the client is obviously a separa...

...r/protocol.c +++ b/server/protocol.c @@ -393,12 +393,13 @@ send_simple_reply (struct connection *conn, ACQUIRE_LOCK_FOR_CURRENT_SCOPE (&conn->write_lock); struct simple_reply reply; int r; + int f = (cmd == NBD_CMD_READ && !error) ? SEND_MORE : 0; reply.magic = htobe32 (NBD_SIMPLE_REPLY_MAGIC); reply.handle = handle; reply.error = htobe32 (nbd_errno (error, false)); - r = conn->send (conn, &reply, sizeof reply, 0); + r = conn->send (conn, &reply, sizeof reply, f); if (r == -1) { nbdkit_error ("write reply: %s: %m", name_of_nbd_cmd (cmd)); re...

...(r == -1) { /* This should never happen because when we enter this state we @@ -69,16 +71,16 @@ return 0; REPLY.CHECK_SIMPLE_OR_STRUCTURED_REPLY: + struct command_in_flight *cmd; uint32_t magic; + uint64_t handle; magic = be32toh (h->sbuf.simple_reply.magic); if (magic == NBD_SIMPLE_REPLY_MAGIC) { SET_NEXT_STATE (%SIMPLE_REPLY.START); - return 0; } else if (magic == NBD_STRUCTURED_REPLY_MAGIC) { SET_NEXT_STATE (%STRUCTURED_REPLY.START); - return 0; } else { SET_NEXT_STATE (%.DEAD); /* We've probably lost synchronization. */ @@ -86,6 +88,29 @@ retu...

...y request other than `NBD_CMD_READ`, -but only if the reply has no data payload. The message looks as -follows: +but only if the reply has no data payload. If extended headers have +been negotiated, a simple reply MUST NOT be used. The message looks +as follows: S: 32 bits, 0x67446698, magic (`NBD_SIMPLE_REPLY_MAGIC`; used to be `NBD_REPLY_MAGIC`) S: 32 bits, error (MAY be zero) -S: 64 bits, handle +S: 64 bits, handle (MUST match the request) S: (*length* bytes of data if the request is of type `NBD_CMD_READ` and *error* is zero) @@ -416,9 +473,9 @@ on the chunks received. A structured...

We should have only one NBD protocol file. Let's make nbdkit's version the canonical one, and use it in libnbd. Rich.

...OVERFLOW: > - return NBD_EOVERFLOW; > + if (flag_df) > + return NBD_EOVERFLOW; > + /* fallthrough */ > case EINVAL: > default: > return NBD_EINVAL; > @@ -368,7 +370,7 @@ send_simple_reply (struct connection *conn, > > reply.magic = htobe32 (NBD_SIMPLE_REPLY_MAGIC); > reply.handle = handle; > - reply.error = htobe32 (nbd_errno (error)); > + reply.error = htobe32 (nbd_errno (error, false)); > > r = conn->send (conn, &reply, sizeof reply); > if (r == -1) { > @@ -573,7 +575,8 @@ send_structured_reply_block_status (struct...

...nt16_t flags; /* Request flags. */ uint16_t type; /* Request type. */ @@ -161,14 +174,14 @@ struct request { } __attribute__((packed)); /* Simple reply (server -> client). */ -struct simple_reply { +struct nbd_simple_reply { uint32_t magic; /* NBD_SIMPLE_REPLY_MAGIC. */ uint32_t error; /* NBD_SUCCESS or one of NBD_E*. */ uint64_t handle; /* Opaque handle. */ } __attribute__((packed)); /* Structured reply (server -> client). */ -struct structured_reply { +struct nbd_structured_reply { uint32_t magic; /* N...

Patch 1 played with an early draft of Rich's Fedora 30 libnbd package: https://bugzilla.redhat.com/show_bug.cgi?id=1713767#c17 Note that comment 21 provides a newer package 0.1.1-1 with a different API; and that libnbd has more unreleased API changes in the pipeline (whether that will be called 0.2 or 0.1.2); so we'll have to tweak things based on what is actually available in distros.

libnbd-0.1.2-1 is now available in Fedora 29/30 updates-testing, although it was not compiled against libxml2 so it lacks uri support (I ended up testing patch 4 with a self-built libnbd). Diffs since v1 - rebase to master, bump from libnbd 0.1 to 0.1.2, add URI support, better timing results Still not done - patch 5 needs associated tests Eric Blake (5): nbd: Check for libnbd nbd:

...uint64_t handle, uint16_t cmd, + uint64_t handle, uint16_t cmd, uint16_t flags, const char *buf, uint32_t count, uint32_t error) { @@ -413,7 +440,7 @@ send_simple_reply (struct connection *conn, reply.magic = htobe32 (NBD_SIMPLE_REPLY_MAGIC); reply.handle = handle; - reply.error = htobe32 (nbd_errno (error, false)); + reply.error = htobe32 (nbd_errno (error, flags)); r = conn->send (conn, &reply, sizeof reply, f); if (r == -1) { @@ -640,7 +667,7 @@ send_structured_reply_error (struct connection *conn, } /* Se...

.../ - uint16_t errlen; - - *trans_out = NULL; - /* magic and handle overlap between simple and structured replies */ - if (read_full (h->fd, &rep, sizeof rep.simple)) - return nbdplug_mark_dead (h); - rep.simple.magic = be32toh (rep.simple.magic); - switch (rep.simple.magic) { - case NBD_SIMPLE_REPLY_MAGIC: - nbdkit_debug ("received simple reply for cookie %#" PRIx64 ", status %s", - rep.simple.handle, - name_of_nbd_error (be32toh (rep.simple.error))); - error = be32toh (rep.simple.error); - break; - case NBD_STRUCTURED_REPLY_MAGIC: -...

.../ - uint16_t errlen; - - *trans_out = NULL; - /* magic and handle overlap between simple and structured replies */ - if (read_full (h->fd, &rep, sizeof rep.simple)) - return nbdplug_mark_dead (h); - rep.simple.magic = be32toh (rep.simple.magic); - switch (rep.simple.magic) { - case NBD_SIMPLE_REPLY_MAGIC: - nbdkit_debug ("received simple reply for cookie %#" PRIx64 ", status %s", - rep.simple.handle, - name_of_nbd_error (be32toh (rep.simple.error))); - error = be32toh (rep.simple.error); - break; - case NBD_STRUCTURED_REPLY_MAGIC: -...