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request.c
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request.c
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/*
* Copyright 2016 Jakub Klama <[email protected]>
* All rights reserved
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted providing that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <sys/param.h>
#include <sys/uio.h>
#if defined(__FreeBSD__)
#include <sys/sbuf.h>
#else
#include "sbuf/sbuf.h"
#endif
#include "lib9p.h"
#include "lib9p_impl.h"
#include "fcall.h"
#include "fid.h"
#include "hashtable.h"
#include "log.h"
#include "linux_errno.h"
#include "backend/backend.h"
#include "threadpool.h"
#define N(x) (sizeof(x) / sizeof(x[0]))
static int l9p_dispatch_tversion(struct l9p_request *req);
static int l9p_dispatch_tattach(struct l9p_request *req);
static int l9p_dispatch_tclunk(struct l9p_request *req);
static int l9p_dispatch_tcreate(struct l9p_request *req);
static int l9p_dispatch_topen(struct l9p_request *req);
static int l9p_dispatch_tread(struct l9p_request *req);
static int l9p_dispatch_tremove(struct l9p_request *req);
static int l9p_dispatch_tstat(struct l9p_request *req);
static int l9p_dispatch_twalk(struct l9p_request *req);
static int l9p_dispatch_twrite(struct l9p_request *req);
static int l9p_dispatch_twstat(struct l9p_request *req);
static int l9p_dispatch_tstatfs(struct l9p_request *req);
static int l9p_dispatch_tlopen(struct l9p_request *req);
static int l9p_dispatch_tlcreate(struct l9p_request *req);
static int l9p_dispatch_tsymlink(struct l9p_request *req);
static int l9p_dispatch_tmknod(struct l9p_request *req);
static int l9p_dispatch_trename(struct l9p_request *req);
static int l9p_dispatch_treadlink(struct l9p_request *req);
static int l9p_dispatch_tgetattr(struct l9p_request *req);
static int l9p_dispatch_tsetattr(struct l9p_request *req);
static int l9p_dispatch_txattrwalk(struct l9p_request *req);
static int l9p_dispatch_txattrcreate(struct l9p_request *req);
static int l9p_dispatch_treaddir(struct l9p_request *req);
static int l9p_dispatch_tfsync(struct l9p_request *req);
static int l9p_dispatch_tlock(struct l9p_request *req);
static int l9p_dispatch_tgetlock(struct l9p_request *req);
static int l9p_dispatch_tlink(struct l9p_request *req);
static int l9p_dispatch_tmkdir(struct l9p_request *req);
static int l9p_dispatch_trenameat(struct l9p_request *req);
static int l9p_dispatch_tunlinkat(struct l9p_request *req);
/*
* Each Txxx handler has a "must run" flag. If it is false,
* we check for a flush request before calling the handler.
* If a flush is already requested we can instantly fail the
* request with EINTR.
*
* Tclunk and Tremove must run because they make their fids
* become invalid. Tversion and Tattach should never get
* a flush request applied (it makes no sense as the connection
* is not really running yet), so it should be harmless to
* set them either way, but for now we have them as must-run.
* Flushing a Tflush is not really allowed either so we keep
* these as must-run too (although they run without being done
* threaded anyway).
*/
struct l9p_handler {
enum l9p_ftype type;
int (*handler)(struct l9p_request *);
bool must_run;
};
static const struct l9p_handler l9p_handlers_no_version[] = {
{L9P_TVERSION, l9p_dispatch_tversion, true},
};
static const struct l9p_handler l9p_handlers_base[] = {
{L9P_TVERSION, l9p_dispatch_tversion, true},
{L9P_TATTACH, l9p_dispatch_tattach, true},
{L9P_TCLUNK, l9p_dispatch_tclunk, true},
{L9P_TFLUSH, l9p_threadpool_tflush, true},
{L9P_TCREATE, l9p_dispatch_tcreate, false},
{L9P_TOPEN, l9p_dispatch_topen, false},
{L9P_TREAD, l9p_dispatch_tread, false},
{L9P_TWRITE, l9p_dispatch_twrite, false},
{L9P_TREMOVE, l9p_dispatch_tremove, true},
{L9P_TSTAT, l9p_dispatch_tstat, false},
{L9P_TWALK, l9p_dispatch_twalk, false},
{L9P_TWSTAT, l9p_dispatch_twstat, false}
};
static const struct l9p_handler l9p_handlers_dotu[] = {
{L9P_TVERSION, l9p_dispatch_tversion, true},
{L9P_TATTACH, l9p_dispatch_tattach, true},
{L9P_TCLUNK, l9p_dispatch_tclunk, true},
{L9P_TFLUSH, l9p_threadpool_tflush, true},
{L9P_TCREATE, l9p_dispatch_tcreate, false},
{L9P_TOPEN, l9p_dispatch_topen, false},
{L9P_TREAD, l9p_dispatch_tread, false},
{L9P_TWRITE, l9p_dispatch_twrite, false},
{L9P_TREMOVE, l9p_dispatch_tremove, true},
{L9P_TSTAT, l9p_dispatch_tstat, false},
{L9P_TWALK, l9p_dispatch_twalk, false},
{L9P_TWSTAT, l9p_dispatch_twstat, false}
};
static const struct l9p_handler l9p_handlers_dotL[] = {
{L9P_TVERSION, l9p_dispatch_tversion, true},
{L9P_TATTACH, l9p_dispatch_tattach, true},
{L9P_TCLUNK, l9p_dispatch_tclunk, true},
{L9P_TFLUSH, l9p_threadpool_tflush, true},
{L9P_TCREATE, l9p_dispatch_tcreate, false},
{L9P_TOPEN, l9p_dispatch_topen, false},
{L9P_TREAD, l9p_dispatch_tread, false},
{L9P_TWRITE, l9p_dispatch_twrite, false},
{L9P_TREMOVE, l9p_dispatch_tremove, true},
{L9P_TSTAT, l9p_dispatch_tstat, false},
{L9P_TWALK, l9p_dispatch_twalk, false},
{L9P_TWSTAT, l9p_dispatch_twstat, false},
{L9P_TSTATFS, l9p_dispatch_tstatfs, false},
{L9P_TLOPEN, l9p_dispatch_tlopen, false},
{L9P_TLCREATE, l9p_dispatch_tlcreate, false},
{L9P_TSYMLINK, l9p_dispatch_tsymlink, false},
{L9P_TMKNOD, l9p_dispatch_tmknod, false},
{L9P_TRENAME, l9p_dispatch_trename, false},
{L9P_TREADLINK, l9p_dispatch_treadlink, false},
{L9P_TGETATTR, l9p_dispatch_tgetattr, false},
{L9P_TSETATTR, l9p_dispatch_tsetattr, false},
{L9P_TXATTRWALK, l9p_dispatch_txattrwalk, false},
{L9P_TXATTRCREATE, l9p_dispatch_txattrcreate, false},
{L9P_TREADDIR, l9p_dispatch_treaddir, false},
{L9P_TFSYNC, l9p_dispatch_tfsync, false},
{L9P_TLOCK, l9p_dispatch_tlock, true},
{L9P_TGETLOCK, l9p_dispatch_tgetlock, true},
{L9P_TLINK, l9p_dispatch_tlink, false},
{L9P_TMKDIR, l9p_dispatch_tmkdir, false},
{L9P_TRENAMEAT, l9p_dispatch_trenameat, false},
{L9P_TUNLINKAT, l9p_dispatch_tunlinkat, false},
};
/*
* NB: version index 0 is reserved for new connections, and
* is a protocol that handles only L9P_TVERSION. Once we get a
* valid version, we start a new session using its dispatch table.
*/
static const struct {
const char *name;
const struct l9p_handler *handlers;
int n_handlers;
} l9p_versions[] = {
{ "<none>", l9p_handlers_no_version, N(l9p_handlers_no_version) },
{ "9P2000", l9p_handlers_base, N(l9p_handlers_base) },
{ "9P2000.u", l9p_handlers_dotu, N(l9p_handlers_dotu), },
{ "9P2000.L", l9p_handlers_dotL, N(l9p_handlers_dotL), },
};
/*
* Run the appropriate handler for this request.
* It's our caller's responsibility to respond.
*/
int
l9p_dispatch_request(struct l9p_request *req)
{
struct l9p_connection *conn;
#if defined(L9P_DEBUG)
struct sbuf *sb;
#endif
size_t i, n;
const struct l9p_handler *handlers, *hp;
bool flush_requested;
conn = req->lr_conn;
flush_requested = req->lr_flushstate == L9P_FLUSH_REQUESTED_PRE_START;
handlers = l9p_versions[conn->lc_version].handlers;
n = (size_t)l9p_versions[conn->lc_version].n_handlers;
for (hp = handlers, i = 0; i < n; hp++, i++)
if (req->lr_req.hdr.type == hp->type)
goto found;
hp = NULL;
found:
#if defined(L9P_DEBUG)
sb = sbuf_new_auto();
if (flush_requested) {
sbuf_cat(sb, "FLUSH requested pre-dispatch");
if (hp != NULL && hp->must_run)
sbuf_cat(sb, ", but must run");
sbuf_cat(sb, ": ");
}
l9p_describe_fcall(&req->lr_req, conn->lc_version, sb);
sbuf_finish(sb);
L9P_LOG(L9P_DEBUG, "%s", sbuf_data(sb));
sbuf_delete(sb);
#endif
if (hp != NULL) {
if (!flush_requested || hp->must_run)
return (hp->handler(req));
return (EINTR);
}
L9P_LOG(L9P_WARNING, "unknown request of type %d",
req->lr_req.hdr.type);
return (ENOSYS);
}
/*
* Translate BSD errno to 9P2000/9P2000.u errno.
*/
static inline int
e29p(int errnum)
{
static int const table[] = {
[ENOTEMPTY] = EPERM,
[EDQUOT] = EPERM,
[ENOSYS] = EPERM, /* ??? */
};
if ((size_t)errnum < N(table) && table[errnum] != 0)
return (table[errnum]);
if (errnum <= ERANGE)
return (errnum);
return (EIO); /* ??? */
}
/*
* Translate BSD errno to Linux errno.
*/
static inline int
e2linux(int errnum)
{
static int const table[] = {
[EDEADLK] = LINUX_EDEADLK,
[EAGAIN] = LINUX_EAGAIN,
[EINPROGRESS] = LINUX_EINPROGRESS,
[EALREADY] = LINUX_EALREADY,
[ENOTSOCK] = LINUX_ENOTSOCK,
[EDESTADDRREQ] = LINUX_EDESTADDRREQ,
[EMSGSIZE] = LINUX_EMSGSIZE,
[EPROTOTYPE] = LINUX_EPROTOTYPE,
[ENOPROTOOPT] = LINUX_ENOPROTOOPT,
[EPROTONOSUPPORT] = LINUX_EPROTONOSUPPORT,
[ESOCKTNOSUPPORT] = LINUX_ESOCKTNOSUPPORT,
[EOPNOTSUPP] = LINUX_EOPNOTSUPP,
[EPFNOSUPPORT] = LINUX_EPFNOSUPPORT,
[EAFNOSUPPORT] = LINUX_EAFNOSUPPORT,
[EADDRINUSE] = LINUX_EADDRINUSE,
[EADDRNOTAVAIL] = LINUX_EADDRNOTAVAIL,
[ENETDOWN] = LINUX_ENETDOWN,
[ENETUNREACH] = LINUX_ENETUNREACH,
[ENETRESET] = LINUX_ENETRESET,
[ECONNABORTED] = LINUX_ECONNABORTED,
[ECONNRESET] = LINUX_ECONNRESET,
[ENOBUFS] = LINUX_ENOBUFS,
[EISCONN] = LINUX_EISCONN,
[ENOTCONN] = LINUX_ENOTCONN,
[ESHUTDOWN] = LINUX_ESHUTDOWN,
[ETOOMANYREFS] = LINUX_ETOOMANYREFS,
[ETIMEDOUT] = LINUX_ETIMEDOUT,
[ECONNREFUSED] = LINUX_ECONNREFUSED,
[ELOOP] = LINUX_ELOOP,
[ENAMETOOLONG] = LINUX_ENAMETOOLONG,
[EHOSTDOWN] = LINUX_EHOSTDOWN,
[EHOSTUNREACH] = LINUX_EHOSTUNREACH,
[ENOTEMPTY] = LINUX_ENOTEMPTY,
[EPROCLIM] = LINUX_EAGAIN,
[EUSERS] = LINUX_EUSERS,
[EDQUOT] = LINUX_EDQUOT,
[ESTALE] = LINUX_ESTALE,
[EREMOTE] = LINUX_EREMOTE,
/* EBADRPC = unmappable? */
/* ERPCMISMATCH = unmappable? */
/* EPROGUNAVAIL = unmappable? */
/* EPROGMISMATCH = unmappable? */
/* EPROCUNAVAIL = unmappable? */
[ENOLCK] = LINUX_ENOLCK,
[ENOSYS] = LINUX_ENOSYS,
/* EFTYPE = unmappable? */
/* EAUTH = unmappable? */
/* ENEEDAUTH = unmappable? */
[EIDRM] = LINUX_EIDRM,
[ENOMSG] = LINUX_ENOMSG,
[EOVERFLOW] = LINUX_EOVERFLOW,
[ECANCELED] = LINUX_ECANCELED,
[EILSEQ] = LINUX_EILSEQ,
/* EDOOFUS = unmappable? */
[EBADMSG] = LINUX_EBADMSG,
[EMULTIHOP] = LINUX_EMULTIHOP,
[ENOLINK] = LINUX_ENOLINK,
[EPROTO] = LINUX_EPROTO,
/* ENOTCAPABLE = unmappable? */
#ifdef ECAPMODE
[ECAPMODE] = EPERM,
#endif
#ifdef ENOTRECOVERABLE
[ENOTRECOVERABLE] = LINUX_ENOTRECOVERABLE,
#endif
#ifdef EOWNERDEAD
[EOWNERDEAD] = LINUX_EOWNERDEAD,
#endif
};
/*
* In case we want to return a raw Linux errno, allow negative
* values a la Linux kernel internals.
*
* Values up to ERANGE are shared across systems (see
* linux_errno.h), except for EAGAIN.
*/
if (errnum < 0)
return (-errnum);
if ((size_t)errnum < N(table) && table[errnum] != 0)
return (table[errnum]);
if (errnum <= ERANGE)
return (errnum);
L9P_LOG(L9P_WARNING, "cannot map errno %d to anything reasonable",
errnum);
return (LINUX_ENOTRECOVERABLE); /* ??? */
}
/*
* Send response to request, or possibly just drop request.
* We also need to know whether to remove the request from
* the tag hash table.
*/
void
l9p_respond(struct l9p_request *req, bool drop, bool rmtag)
{
struct l9p_connection *conn = req->lr_conn;
size_t iosize;
#if defined(L9P_DEBUG)
struct sbuf *sb;
const char *ftype;
#endif
int error;
req->lr_resp.hdr.tag = req->lr_req.hdr.tag;
error = req->lr_error;
if (error == 0)
req->lr_resp.hdr.type = req->lr_req.hdr.type + 1;
else {
if (conn->lc_version == L9P_2000L) {
req->lr_resp.hdr.type = L9P_RLERROR;
req->lr_resp.error.errnum = (uint32_t)e2linux(error);
} else {
req->lr_resp.hdr.type = L9P_RERROR;
req->lr_resp.error.ename = strerror(error);
req->lr_resp.error.errnum = (uint32_t)e29p(error);
}
}
#if defined(L9P_DEBUG)
sb = sbuf_new_auto();
l9p_describe_fcall(&req->lr_resp, conn->lc_version, sb);
sbuf_finish(sb);
switch (req->lr_flushstate) {
case L9P_FLUSH_NONE:
ftype = "";
break;
case L9P_FLUSH_REQUESTED_PRE_START:
ftype = "FLUSH requested pre-dispatch: ";
break;
case L9P_FLUSH_REQUESTED_POST_START:
ftype = "FLUSH requested while running: ";
break;
case L9P_FLUSH_TOOLATE:
ftype = "FLUSH requested too late: ";
break;
}
L9P_LOG(L9P_DEBUG, "%s%s%s",
drop ? "DROP: " : "", ftype, sbuf_data(sb));
sbuf_delete(sb);
#endif
error = drop ? 0 :
l9p_pufcall(&req->lr_resp_msg, &req->lr_resp, conn->lc_version);
if (rmtag)
ht_remove(&conn->lc_requests, req->lr_req.hdr.tag);
if (error != 0) {
L9P_LOG(L9P_ERROR, "cannot pack response");
drop = true;
}
if (drop) {
conn->lc_lt.lt_drop_response(req,
req->lr_resp_msg.lm_iov, req->lr_resp_msg.lm_niov,
conn->lc_lt.lt_aux);
} else {
iosize = req->lr_resp_msg.lm_size;
/*
* Include I/O size in calculation for Rread and
* Rreaddir responses.
*/
if (req->lr_resp.hdr.type == L9P_RREAD ||
req->lr_resp.hdr.type == L9P_RREADDIR)
iosize += req->lr_resp.io.count;
conn->lc_lt.lt_send_response(req,
req->lr_resp_msg.lm_iov, req->lr_resp_msg.lm_niov,
iosize, conn->lc_lt.lt_aux);
}
l9p_freefcall(&req->lr_req);
l9p_freefcall(&req->lr_resp);
free(req);
}
/*
* This allows a caller to iterate through the data in a
* read or write request (creating the data if packing,
* scanning through it if unpacking). This is used for
* writing readdir entries, so mode should be L9P_PACK
* (but we allow L9P_UNPACK so that debug code can also scan
* through the data later, if desired).
*
* This relies on the Tread op having positioned the request's
* iov to the beginning of the data buffer (note the l9p_seek_iov
* in l9p_dispatch_tread).
*/
void
l9p_init_msg(struct l9p_message *msg, struct l9p_request *req,
enum l9p_pack_mode mode)
{
msg->lm_size = 0;
msg->lm_mode = mode;
msg->lm_cursor_iov = 0;
msg->lm_cursor_offset = 0;
msg->lm_niov = req->lr_data_niov;
memcpy(msg->lm_iov, req->lr_data_iov,
sizeof (struct iovec) * req->lr_data_niov);
}
enum fid_lookup_flags {
F_REQUIRE_OPEN = 0x01, /* require that the file be marked OPEN */
F_REQUIRE_DIR = 0x02, /* require that the file be marked ISDIR */
F_REQUIRE_XATTR = 0x04, /* require that the file be marked XATTR */
F_REQUIRE_AUTH = 0x08, /* require that the fid be marked AUTH */
F_FORBID_OPEN = 0x10, /* forbid that the file be marked OPEN */
F_FORBID_DIR = 0x20, /* forbid that the file be marked ISDIR */
F_FORBID_XATTR = 0x40, /* forbid that the file be marked XATTR */
F_ALLOW_AUTH = 0x80, /* allow that the fid be marked AUTH */
};
/*
* Look up a fid. It must correspond to a valid file, else we return
* the given errno (some "not a valid fid" calls must return EIO and
* some must return EINVAL and qemu returns ENOENT in other cases and
* so on, so we just provide a general "return this error number").
*
* Callers may also set constraints: fid must be (or not be) open,
* must be (or not be) a directory, must be (or not be) an xattr.
*
* Only one op has a fid that *must* be an auth fid. Most ops forbid
* auth fids So instead of FORBID we have ALLOW here and the default
* is FORBID.
*/
static inline int
fid_lookup(struct l9p_connection *conn, uint32_t fid, int err, int flags,
struct l9p_fid **afile)
{
struct l9p_fid *file;
file = ht_find(&conn->lc_files, fid);
if (file == NULL)
return (err);
/*
* As soon as we go multithreaded / async, this
* assert has to become "return EINVAL" or "return err".
*
* We may also need a way to mark a fid as
* "in async op" (valid for some purposes, but cannot be
* used elsewhere until async op is completed or aborted).
*
* For now, this serves for bug-detecting.
*/
assert(l9p_fid_isvalid(file));
/*
* Note that we're inline expanded and flags is constant,
* so unnecessary tests just drop out entirely.
*/
if ((flags & F_REQUIRE_OPEN) && !l9p_fid_isopen(file))
return (EINVAL);
if ((flags & F_FORBID_OPEN) && l9p_fid_isopen(file))
return (EINVAL);
if ((flags & F_REQUIRE_DIR) && !l9p_fid_isdir(file))
return (ENOTDIR);
if ((flags & F_FORBID_DIR) && l9p_fid_isdir(file))
return (EISDIR);
if ((flags & F_REQUIRE_XATTR) && !l9p_fid_isxattr(file))
return (EINVAL);
if ((flags & F_FORBID_XATTR) && l9p_fid_isxattr(file))
return (EINVAL);
if (l9p_fid_isauth(file)) {
if ((flags & (F_REQUIRE_AUTH | F_ALLOW_AUTH)) == 0)
return (EINVAL);
} else if (flags & F_REQUIRE_AUTH)
return (EINVAL);
*afile = file;
return (0);
}
/*
* Append variable-size stat object and adjust io count.
* Returns 0 if the entire stat object was packed, -1 if not.
* A fully packed object updates the request's io count.
*
* Caller must use their own private l9p_message object since
* a partially packed object will leave the message object in
* a useless state.
*
* Frees the stat object.
*/
int
l9p_pack_stat(struct l9p_message *msg, struct l9p_request *req,
struct l9p_stat *st)
{
struct l9p_connection *conn = req->lr_conn;
uint16_t size = l9p_sizeof_stat(st, conn->lc_version);
int ret = 0;
assert(msg->lm_mode == L9P_PACK);
if (req->lr_resp.io.count + size > req->lr_req.io.count ||
l9p_pustat(msg, st, conn->lc_version) < 0)
ret = -1;
else
req->lr_resp.io.count += size;
l9p_freestat(st);
return (ret);
}
static int
l9p_dispatch_tversion(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_server *server = conn->lc_server;
enum l9p_version remote_version = L9P_INVALID_VERSION;
size_t i;
const char *remote_version_name;
for (i = 0; i < N(l9p_versions); i++) {
if (strcmp(req->lr_req.version.version,
l9p_versions[i].name) == 0) {
remote_version = (enum l9p_version)i;
break;
}
}
if (remote_version == L9P_INVALID_VERSION) {
L9P_LOG(L9P_ERROR, "unsupported remote version: %s",
req->lr_req.version.version);
return (ENOSYS);
}
remote_version_name = l9p_versions[remote_version].name;
L9P_LOG(L9P_INFO, "remote version: %s", remote_version_name);
L9P_LOG(L9P_INFO, "local version: %s",
l9p_versions[server->ls_max_version].name);
conn->lc_version = MIN(remote_version, server->ls_max_version);
conn->lc_msize = MIN(req->lr_req.version.msize, conn->lc_msize);
conn->lc_max_io_size = conn->lc_msize - 24;
req->lr_resp.version.version = strdup(remote_version_name);
req->lr_resp.version.msize = conn->lc_msize;
return (0);
}
static int
l9p_dispatch_tattach(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/*
* We still don't have Tauth yet, but let's code this part
* anyway.
*
* Look up the auth fid first since if it fails we can just
* return immediately.
*/
if (req->lr_req.tattach.afid != L9P_NOFID) {
error = fid_lookup(conn, req->lr_req.tattach.afid, EINVAL,
F_REQUIRE_AUTH, &req->lr_fid2);
if (error)
return (error);
} else
req->lr_fid2 = NULL;
fid = l9p_connection_alloc_fid(conn, req->lr_req.hdr.fid);
if (fid == NULL)
return (EINVAL);
be = conn->lc_server->ls_backend;
req->lr_fid = fid;
/* For backend convenience, set NONUNAME on 9P2000. */
if (conn->lc_version == L9P_2000)
req->lr_req.tattach.n_uname = L9P_NONUNAME;
error = be->attach(be->softc, req);
/*
* On success, fid becomes valid; on failure, disconnect.
* It certainly *should* be a directory here...
*/
if (error == 0) {
l9p_fid_setvalid(fid);
if (req->lr_resp.rattach.qid.type & L9P_QTDIR)
l9p_fid_setdir(fid);
} else
l9p_connection_remove_fid(conn, fid);
return (error);
}
static int
l9p_dispatch_tclunk(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/* Note that clunk is the only way to dispose of an auth fid. */
error = fid_lookup(conn, req->lr_req.hdr.fid, ENOENT,
F_ALLOW_AUTH, &fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
l9p_fid_unsetvalid(fid);
/*
* If it's an xattr fid there must, by definition, be an
* xattrclunk. The xattrclunk function can only be NULL if
* xattrwalk and xattrcreate are NULL or always return error.
*
* Q: do we want to allow async xattrclunk in case of very
* large xattr create? This will make things difficult,
* so probably not.
*/
if (l9p_fid_isxattr(fid))
error = be->xattrclunk(be->softc, fid);
else
error = be->clunk(be->softc, fid);
/* fid is now gone regardless of any error return */
l9p_connection_remove_fid(conn, fid);
return (error);
}
static int
l9p_dispatch_tcreate(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
uint32_t dmperm;
int error;
/* Incoming fid must represent a directory that has not been opened. */
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL,
F_REQUIRE_DIR | F_FORBID_OPEN, &req->lr_fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
dmperm = req->lr_req.tcreate.perm;
#define MKDIR_OR_SIMILAR \
(L9P_DMDIR | L9P_DMSYMLINK | L9P_DMNAMEDPIPE | L9P_DMSOCKET | L9P_DMDEVICE)
/*
* TODO:
* - check new file name
* - break out different kinds of create (file vs mkdir etc)
* - add async file-create (leaves req->lr_fid in limbo)
*
* A successful file-create changes the fid into an open file.
*/
error = be->create(be->softc, req);
if (error == 0 && (dmperm & MKDIR_OR_SIMILAR) == 0) {
l9p_fid_unsetdir(req->lr_fid);
l9p_fid_setopen(req->lr_fid);
}
return (error);
}
static int
l9p_dispatch_topen(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
int error;
error = fid_lookup(conn, req->lr_req.hdr.fid, ENOENT,
F_FORBID_OPEN | F_FORBID_XATTR, &req->lr_fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
/*
* TODO:
* - add async open (leaves req->lr_fid in limbo)
*/
error = be->open(be->softc, req);
if (error == 0)
l9p_fid_setopen(req->lr_fid);
return (error);
}
static int
l9p_dispatch_tread(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/* Xattr fids are not open, so we need our own tests. */
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL, 0, &req->lr_fid);
if (error)
return (error);
/*
* Adjust so that writing messages (packing data) starts
* right after the count field in the response.
*
* size[4] + Rread[1] + tag[2] + count[4] = 11
*/
l9p_seek_iov(req->lr_resp_msg.lm_iov, req->lr_resp_msg.lm_niov,
req->lr_data_iov, &req->lr_data_niov, 11);
/*
* If it's an xattr fid there must, by definition, be an
* xattrread. The xattrread function can only be NULL if
* xattrwalk and xattrcreate are NULL or always return error.
*
* TODO:
* separate out directory-read
* allow async read
*/
be = conn->lc_server->ls_backend;
fid = req->lr_fid;
if (l9p_fid_isxattr(fid)) {
error = be->xattrread(be->softc, req);
} else if (l9p_fid_isopen(fid)) {
error = be->read(be->softc, req);
} else {
error = EINVAL;
}
return (error);
}
static int
l9p_dispatch_tremove(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/*
* ?? Should we allow Tremove on auth fids? If so, do
* we pretend it is just a Tclunk?
*/
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL, 0, &fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
l9p_fid_unsetvalid(fid);
error = be->remove(be->softc, fid);
/* fid is now gone regardless of any error return */
l9p_connection_remove_fid(conn, fid);
return (error);
}
static int
l9p_dispatch_tstat(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/* Allow Tstat on auth fid? Seems harmless enough... */
error = fid_lookup(conn, req->lr_req.hdr.fid, ENOENT,
F_ALLOW_AUTH, &fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
req->lr_fid = fid;
error = be->stat(be->softc, req);
if (error == 0) {
if (l9p_fid_isauth(fid))
req->lr_resp.rstat.stat.qid.type |= L9P_QTAUTH;
/* should we check req->lr_resp.rstat.qid.type L9P_QTDIR bit? */
if (req->lr_resp.rstat.stat.qid.type &= L9P_QTDIR)
l9p_fid_setdir(fid);
else
l9p_fid_unsetdir(fid);
}
return (error);
}
static int
l9p_dispatch_twalk(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid, *newfid;
uint16_t n;
int error;
/* Can forbid XATTR, but cannot require DIR. */
error = fid_lookup(conn, req->lr_req.hdr.fid, ENOENT,
F_FORBID_XATTR, &fid);
if (error)
return (error);
if (req->lr_req.twalk.hdr.fid != req->lr_req.twalk.newfid) {
newfid = l9p_connection_alloc_fid(conn,
req->lr_req.twalk.newfid);
if (newfid == NULL)
return (EINVAL);
} else
newfid = fid;
be = conn->lc_server->ls_backend;
req->lr_fid = fid;
req->lr_newfid = newfid;
error = be->walk(be->softc, req);
/*
* If newfid == fid, then fid itself has (potentially) changed,
* but is still valid. Otherwise set newfid valid on
* success, and destroy it on error.
*/
if (newfid != fid) {
if (error == 0)
l9p_fid_setvalid(newfid);
else
l9p_connection_remove_fid(conn, newfid);
}
/*
* If we walked any name elements, the last (n-1'th) qid
* has the type (dir vs file) for the new fid. Otherwise
* the type of newfid is the same as fid. Of course, if
* n==0 and fid==newfid, fid is already set up correctly
* as the whole thing was a big no-op, but it's safe to
* copy its dir bit to itself.
*/
if (error == 0) {
n = req->lr_resp.rwalk.nwqid;
if (n > 0) {
if (req->lr_resp.rwalk.wqid[n - 1].type & L9P_QTDIR)
l9p_fid_setdir(newfid);
} else {
if (l9p_fid_isdir(fid))
l9p_fid_setdir(newfid);
}
}
return (error);
}
static int
l9p_dispatch_twrite(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/* Cannot require open due to xattr write, but can forbid dir. */
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL,
F_FORBID_DIR, &req->lr_fid);
if (error)
return (error);
/*
* Adjust to point to the data to be written (a la
* l9p_dispatch_tread, but we're pointing into the request
* buffer rather than the response):
*
* size[4] + Twrite[1] + tag[2] + fid[4] + offset[8] + count[4] = 23
*/
l9p_seek_iov(req->lr_req_msg.lm_iov, req->lr_req_msg.lm_niov,
req->lr_data_iov, &req->lr_data_niov, 23);
/*
* Unlike read, write and xattrwrite are optional (for R/O fs).
*
* TODO:
* allow async write
*/
be = conn->lc_server->ls_backend;
fid = req->lr_fid;
if (l9p_fid_isxattr(fid)) {
error = be->xattrwrite != NULL ?
be->xattrwrite(be->softc, req) : ENOSYS;
} else if (l9p_fid_isopen(fid)) {
error = be->write != NULL ?
be->write(be->softc, req) : ENOSYS;
} else {
error = EINVAL;
}
return (error);
}
static int
l9p_dispatch_twstat(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
int error;
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL,
F_FORBID_XATTR, &req->lr_fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
error = be->wstat != NULL ? be->wstat(be->softc, req) : ENOSYS;
return (error);
}
static int
l9p_dispatch_tstatfs(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
int error;
/* Should we allow statfs on auth fids? */
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL, 0, &req->lr_fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
error = be->statfs(be->softc, req);
return (error);
}
static int
l9p_dispatch_tlopen(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
int error;