search for: nbd_max_str

...+ uint32_t len; + uint32_t reply; + + len = be32toh (h->sbuf.or.option_reply.replylen); + reply = be32toh (h->sbuf.or.option_reply.reply); + if (!NBD_REP_IS_ERR (reply)) { + set_error (0, "handshake: unexpected option reply type %d", reply); + return -1; + } + + assert (NBD_MAX_STRING < sizeof h->sbuf.or.payload); + if (len > NBD_MAX_STRING) { + set_error (0, "handshake: option error string too long"); + return -1; + } + + if (len > 0) + debug (h, "handshake: server error message: %.*s", (int) len, + h->sbuf.or.payload....

.....3b5d144e 100644 > --- a/server/protocol-handshake-newstyle.c > +++ b/server/protocol-handshake-newstyle.c > @@ -48,7 +48,7 @@ > #define MAX_NR_OPTIONS 32 > > /* Maximum length of any option data (bytes). */ > -#define MAX_OPTION_LENGTH 4096 > +#define MAX_OPTION_LENGTH (NBD_MAX_STRING * 4) I may have missed it - why was * 4 chosen? Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows insta...

Since the v1 series (0/4, at [1]), I've applied patches 1 and 2, rewritten patch 3 [Forbid NUL in export and context names] into patch 4 here, patch 4 there turned into patch 6 here, and everything else here is new. [1]https://www.redhat.com/archives/libguestfs/2019-September/msg00180.html I don't know if there is a handy reusable function for checking whether a string contains valid

...ocol-handshake-newstyle.c index 34958360..3b5d144e 100644 --- a/server/protocol-handshake-newstyle.c +++ b/server/protocol-handshake-newstyle.c @@ -48,7 +48,7 @@ #define MAX_NR_OPTIONS 32 /* Maximum length of any option data (bytes). */ -#define MAX_OPTION_LENGTH 4096 +#define MAX_OPTION_LENGTH (NBD_MAX_STRING * 4) /* Receive newstyle options. */ static int @@ -255,7 +255,7 @@ negotiate_handshake_newstyle_options (struct connection *conn) uint64_t version; uint32_t option; uint32_t optlen; - char data[MAX_OPTION_LENGTH+1]; + CLEANUP_FREE char *data = NULL; struct nbd_export_name_optio...

I'm still playing with ideas on how to split rstate from wstate (so that we can send a request without waiting for POLLIN to complete a pending reply), but this is some preliminary refactoring I found useful. I also fixed a couple of bugs while in the area (already pushed). There's a question of whether we want nbd_handle to be nearly 5k, or if we should instead keep it small and add one

An incremental improvement on top of listing exports. I still think it's worth experimenting with revisiting how our API for list mode should actually work [1] (so that we can reuse a single connection for both grabbing the list and finally using NBD_OPT_GO), but this change was easier to whip together while still thinking about that. [1]

...N: +#ifdef AF_VSOCK + vsock = true; + break; +#else + fprintf (stderr, "%s: AF_VSOCK is not supported on this platform\n", + program_name); + exit (EXIT_FAILURE); +#endif + case 'e': exportname = optarg; if (strnlen (exportname, NBD_MAX_STRING + 1) > NBD_MAX_STRING) { @@ -826,15 +842,22 @@ start_serving (void) size_t nr_socks; size_t i; - /* If the user has mixed up -p/-U/-s options, then give an error. + /* If the user has mixed up -p/--run/-s/-U/--vsock options, then + * give an error. * * XXX Actually the ser...

v1 was discussed here: https://www.redhat.com/archives/libguestfs/2019-October/thread.html#00100 v2: - Bind to VMADDR_CID_ANY (instead of HOST) and update the documentation accordingly. - Don't bother with SOCK_CLOEXEC fallback path that can never be used. Rich.

...lts of nbd_opt_list. */ - size_t nr_exports; - struct export *exports; + struct command_cb opt_cb; /* Full info mode. */ bool full_info; @@ -186,7 +192,7 @@ struct nbd_handle { union { struct { struct nbd_fixed_new_option_reply_server server; - char str[NBD_MAX_STRING * 2]; /* name and description */ + char str[NBD_MAX_STRING * 2 + 1]; /* name, description, NUL */ } __attribute__((packed)) server; struct nbd_fixed_new_option_reply_info_export export; struct nbd_fixed_new_option_reply_info_block_size block_size; @@ -324,14 +...

...t; + len = be32toh (h->sbuf.or.option_reply.replylen); > + reply = be32toh (h->sbuf.or.option_reply.reply); > + if (!NBD_REP_IS_ERR (reply)) { > + set_error (0, "handshake: unexpected option reply type %d", reply); > + return -1; > + } > + > + assert (NBD_MAX_STRING < sizeof h->sbuf.or.payload); Missing an addition of #include <assert.h>. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org

...server/protocol-handshake-newstyle.c >> +++ b/server/protocol-handshake-newstyle.c >> @@ -48,7 +48,7 @@ >> #define MAX_NR_OPTIONS 32 >> >> /* Maximum length of any option data (bytes). */ >> -#define MAX_OPTION_LENGTH 4096 >> +#define MAX_OPTION_LENGTH (NBD_MAX_STRING * 4) > > I may have missed it - why was * 4 chosen? NBD_OPT_SET_META_CONTEXT allows two strings plus a few glue bytes, so more than 8k of data from a compliant client. 16k is the next power of 2. We can bump it larger if we want, especially since 16k pales in comparison to our 32M l...

...e-newstyle.c | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/server/internal.h b/server/internal.h index e6a22f1a..97e417f9 100644 --- a/server/internal.h +++ b/server/internal.h @@ -200,6 +200,7 @@ struct connection { size_t nr_handles; char exportname[NBD_MAX_STRING + 1]; + uint32_t exportnamelen; uint32_t cflags; uint16_t eflags; bool using_tls; diff --git a/server/protocol-handshake-newstyle.c b/server/protocol-handshake-newstyle.c index 3b5d144e..2480d7a3 100644 --- a/server/protocol-handshake-newstyle.c +++ b/server/protocol-handshake-newstyle...

This is a series of patches to libnbd and nbdkit adding AF_VSOCK support. On the host side it allows you to start an nbdkit instance which listens on a virtio-vsock socket: $ ./nbdkit -fv --vsock memory 1G ... nbdkit: debug: bound to vsock 2:10809 On the guest side you can then use libnbd to connect to the server: $ ./run nbdsh -c 'h.connect_vsock(2, 10809)' -c

...eXXtoh or htobeXX when reading or writing + * order, so you must use beXXtoh or htobeXX when reading or writing * these structures. */ +#if defined(__GNUC__) || defined(__clang__) +#define NBD_ATTRIBUTE_PACKED __attribute__((__packed__)) +#else +#define NBD_ATTRIBUTE_PACKED +#endif + #define NBD_MAX_STRING 4096 /* Maximum length of a string field */ /* Old-style handshake. */ @@ -50,7 +56,7 @@ struct nbd_old_handshake { uint16_t gflags; /* global flags */ uint16_t eflags; /* per-export flags */ char zeroes[124]; /* must be sent as zero bytes */ -} __attr...

Necessary when writing a client that wants to avoid unnecessary EINVAL errors from sending unaligned requests. At some point, we may want to add synchronous convenience API wrappers that do request splitting or read-modify-write to obey server constraints while still appearing to the library client as accepting any possible request. But such a wrapper should only be synchronous and not copied to

...lts of nbd_opt_list. */ - size_t nr_exports; - struct export *exports; + struct command_cb opt_cb; /* Full info mode. */ bool full_info; @@ -186,7 +192,7 @@ struct nbd_handle { union { struct { struct nbd_fixed_new_option_reply_server server; - char str[NBD_MAX_STRING * 2]; /* name and description */ + char str[NBD_MAX_STRING * 2 + 1]; /* name, description, NUL */ } __attribute__((packed)) server; struct nbd_fixed_new_option_reply_info_export export; struct nbd_fixed_new_option_reply_info_block_size block_size; @@ -324,14 +...

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

.....3b5d144e 100644 > --- a/server/protocol-handshake-newstyle.c > +++ b/server/protocol-handshake-newstyle.c > @@ -48,7 +48,7 @@ > #define MAX_NR_OPTIONS 32 > > /* Maximum length of any option data (bytes). */ > -#define MAX_OPTION_LENGTH 4096 > +#define MAX_OPTION_LENGTH (NBD_MAX_STRING * 4) > > /* Receive newstyle options. */ > static int > @@ -255,7 +255,7 @@ negotiate_handshake_newstyle_options (struct connection *conn) > uint64_t version; > uint32_t option; > uint32_t optlen; > - char data[MAX_OPTION_LENGTH+1]; > + CLEANUP_FREE char...

...eXXtoh or htobeXX when reading or writing + * order, so you must use beXXtoh or htobeXX when reading or writing * these structures. */ +#if defined(__GNUC__) || defined(__clang__) +#define NBD_ATTRIBUTE_PACKED __attribute__((__packed__)) +#else +#define NBD_ATTRIBUTE_PACKED +#endif + #define NBD_MAX_STRING 4096 /* Maximum length of a string field */ /* Old-style handshake. */ @@ -55,7 +56,7 @@ struct nbd_old_handshake { uint16_t gflags; /* global flags */ uint16_t eflags; /* per-export flags */ char zeroes[124]; /* must be sent as zero bytes */ -} __attr...

.../* -e */ bool foreground; /* -f */ const char *ipaddr; /* -i */ enum log_to log_to = LOG_TO_DEFAULT; /* --log */ @@ -345,13 +344,7 @@ main (int argc, char *argv[]) break; case 'e': - exportname = optarg; - if (strnlen (exportname, NBD_MAX_STRING + 1) > NBD_MAX_STRING) { - nbdkit_error ("export name too long"); - exit (EXIT_FAILURE); - } - /* TODO: Check that name is valid UTF-8? */ - newstyle = true; + /* Does nothing, ignored for compatibility with older nbdkit. */ break; cas...