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DEFINITIONS
This source file includes following definitions.
- smb_init_request_cache
- smb_destroy_request_cache
- smb_do_alloc_request
- smb_alloc_request
- smb_free_request
- smb_rget
- smb_rput
- smb_setup_bcc
- smb_setup_request
- smb_setup_trans2request
- smb_add_request
- smb_request_send_req
- smb_request_send_server
- find_request
- smb_init_request
- smb_recv_param
- smb_recv_data
- smb_recv_trans2
- smb_request_recv
/*
* request.c
*
* Copyright (C) 2001 by Urban Widmark
*
* Please add a note about your changes to smbfs in the ChangeLog file.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/net.h>
#include <linux/sched.h>
#include <linux/smb_fs.h>
#include <linux/smbno.h>
#include <linux/smb_mount.h>
#include "smb_debug.h"
#include "request.h"
#include "proto.h"
/* #define SMB_SLAB_DEBUG (SLAB_RED_ZONE | SLAB_POISON) */
#define SMB_SLAB_DEBUG 0
/* cache for request structures */
static struct kmem_cache *req_cachep;
static int smb_request_send_req(struct smb_request *req);
/*
/proc/slabinfo:
name, active, num, objsize, active_slabs, num_slaps, #pages
*/
int smb_init_request_cache(void)
{
req_cachep = kmem_cache_create("smb_request",
sizeof(struct smb_request), 0,
SMB_SLAB_DEBUG | SLAB_HWCACHE_ALIGN,
NULL);
if (req_cachep == NULL)
return -ENOMEM;
return 0;
}
void smb_destroy_request_cache(void)
{
kmem_cache_destroy(req_cachep);
}
/*
* Allocate and initialise a request structure
*/
static struct smb_request *smb_do_alloc_request(struct smb_sb_info *server,
int bufsize)
{
struct smb_request *req;
unsigned char *buf = NULL;
req = kmem_cache_zalloc(req_cachep, GFP_KERNEL);
VERBOSE("allocating request: %p\n", req);
if (!req)
goto out;
if (bufsize > 0) {
buf = kmalloc(bufsize, GFP_NOFS);
if (!buf) {
kmem_cache_free(req_cachep, req);
return NULL;
}
}
req->rq_buffer = buf;
req->rq_bufsize = bufsize;
req->rq_server = server;
init_waitqueue_head(&req->rq_wait);
INIT_LIST_HEAD(&req->rq_queue);
atomic_set(&req->rq_count, 1);
out:
return req;
}
struct smb_request *smb_alloc_request(struct smb_sb_info *server, int bufsize)
{
struct smb_request *req = NULL;
for (;;) {
atomic_inc(&server->nr_requests);
if (atomic_read(&server->nr_requests) <= MAX_REQUEST_HARD) {
req = smb_do_alloc_request(server, bufsize);
if (req != NULL)
break;
}
#if 0
/*
* Try to free up at least one request in order to stay
* below the hard limit
*/
if (nfs_try_to_free_pages(server))
continue;
if (fatal_signal_pending(current))
return ERR_PTR(-ERESTARTSYS);
current->policy = SCHED_YIELD;
schedule();
#else
/* FIXME: we want something like nfs does above, but that
requires changes to all callers and can wait. */
break;
#endif
}
return req;
}
static void smb_free_request(struct smb_request *req)
{
atomic_dec(&req->rq_server->nr_requests);
if (req->rq_buffer && !(req->rq_flags & SMB_REQ_STATIC))
kfree(req->rq_buffer);
kfree(req->rq_trans2buffer);
kmem_cache_free(req_cachep, req);
}
/*
* What prevents a rget to race with a rput? The count must never drop to zero
* while it is in use. Only rput if it is ok that it is free'd.
*/
static void smb_rget(struct smb_request *req)
{
atomic_inc(&req->rq_count);
}
void smb_rput(struct smb_request *req)
{
if (atomic_dec_and_test(&req->rq_count)) {
list_del_init(&req->rq_queue);
smb_free_request(req);
}
}
/* setup to receive the data part of the SMB */
static int smb_setup_bcc(struct smb_request *req)
{
int result = 0;
req->rq_rlen = smb_len(req->rq_header) + 4 - req->rq_bytes_recvd;
if (req->rq_rlen > req->rq_bufsize) {
PARANOIA("Packet too large %d > %d\n",
req->rq_rlen, req->rq_bufsize);
return -ENOBUFS;
}
req->rq_iov[0].iov_base = req->rq_buffer;
req->rq_iov[0].iov_len = req->rq_rlen;
req->rq_iovlen = 1;
return result;
}
/*
* Prepare a "normal" request structure.
*/
static int smb_setup_request(struct smb_request *req)
{
int len = smb_len(req->rq_header) + 4;
req->rq_slen = len;
/* if we expect a data part in the reply we set the iov's to read it */
if (req->rq_resp_bcc)
req->rq_setup_read = smb_setup_bcc;
/* This tries to support re-using the same request */
req->rq_bytes_sent = 0;
req->rq_rcls = 0;
req->rq_err = 0;
req->rq_errno = 0;
req->rq_fragment = 0;
kfree(req->rq_trans2buffer);
req->rq_trans2buffer = NULL;
return 0;
}
/*
* Prepare a transaction2 request structure
*/
static int smb_setup_trans2request(struct smb_request *req)
{
struct smb_sb_info *server = req->rq_server;
int mparam, mdata;
static unsigned char padding[4];
/* I know the following is very ugly, but I want to build the
smb packet as efficiently as possible. */
const int smb_parameters = 15;
const int header = SMB_HEADER_LEN + 2 * smb_parameters + 2;
const int oparam = ALIGN(header + 3, sizeof(u32));
const int odata = ALIGN(oparam + req->rq_lparm, sizeof(u32));
const int bcc = (req->rq_data ? odata + req->rq_ldata :
oparam + req->rq_lparm) - header;
if ((bcc + oparam) > server->opt.max_xmit)
return -ENOMEM;
smb_setup_header(req, SMBtrans2, smb_parameters, bcc);
/*
* max parameters + max data + max setup == bufsize to make NT4 happy
* and not abort the transfer or split into multiple responses. It also
* makes smbfs happy as handling packets larger than the buffer size
* is extra work.
*
* OS/2 is probably going to hate me for this ...
*/
mparam = SMB_TRANS2_MAX_PARAM;
mdata = req->rq_bufsize - mparam;
mdata = server->opt.max_xmit - mparam - 100;
if (mdata < 1024) {
mdata = 1024;
mparam = 20;
}
#if 0
/* NT/win2k has ~4k max_xmit, so with this we request more than it wants
to return as one SMB. Useful for testing the fragmented trans2
handling. */
mdata = 8192;
#endif
WSET(req->rq_header, smb_tpscnt, req->rq_lparm);
WSET(req->rq_header, smb_tdscnt, req->rq_ldata);
WSET(req->rq_header, smb_mprcnt, mparam);
WSET(req->rq_header, smb_mdrcnt, mdata);
WSET(req->rq_header, smb_msrcnt, 0); /* max setup always 0 ? */
WSET(req->rq_header, smb_flags, 0);
DSET(req->rq_header, smb_timeout, 0);
WSET(req->rq_header, smb_pscnt, req->rq_lparm);
WSET(req->rq_header, smb_psoff, oparam - 4);
WSET(req->rq_header, smb_dscnt, req->rq_ldata);
WSET(req->rq_header, smb_dsoff, req->rq_data ? odata - 4 : 0);
*(req->rq_header + smb_suwcnt) = 0x01; /* setup count */
*(req->rq_header + smb_suwcnt + 1) = 0x00; /* reserved */
WSET(req->rq_header, smb_setup0, req->rq_trans2_command);
req->rq_iovlen = 2;
req->rq_iov[0].iov_base = (void *) req->rq_header;
req->rq_iov[0].iov_len = oparam;
req->rq_iov[1].iov_base = (req->rq_parm==NULL) ? padding : req->rq_parm;
req->rq_iov[1].iov_len = req->rq_lparm;
req->rq_slen = oparam + req->rq_lparm;
if (req->rq_data) {
req->rq_iovlen += 2;
req->rq_iov[2].iov_base = padding;
req->rq_iov[2].iov_len = odata - oparam - req->rq_lparm;
req->rq_iov[3].iov_base = req->rq_data;
req->rq_iov[3].iov_len = req->rq_ldata;
req->rq_slen = odata + req->rq_ldata;
}
/* always a data part for trans2 replies */
req->rq_setup_read = smb_setup_bcc;
return 0;
}
/*
* Add a request and tell smbiod to process it
*/
int smb_add_request(struct smb_request *req)
{
long timeleft;
struct smb_sb_info *server = req->rq_server;
int result = 0;
smb_setup_request(req);
if (req->rq_trans2_command) {
if (req->rq_buffer == NULL) {
PARANOIA("trans2 attempted without response buffer!\n");
return -EIO;
}
result = smb_setup_trans2request(req);
}
if (result < 0)
return result;
#ifdef SMB_DEBUG_PACKET_SIZE
add_xmit_stats(req);
#endif
/* add 'req' to the queue of requests */
if (smb_lock_server_interruptible(server))
return -EINTR;
/*
* Try to send the request as the process. If that fails we queue the
* request and let smbiod send it later.
*/
/* FIXME: each server has a number on the maximum number of parallel
requests. 10, 50 or so. We should not allow more requests to be
active. */
if (server->mid > 0xf000)
server->mid = 0;
req->rq_mid = server->mid++;
WSET(req->rq_header, smb_mid, req->rq_mid);
result = 0;
if (server->state == CONN_VALID) {
if (list_empty(&server->xmitq))
result = smb_request_send_req(req);
if (result < 0) {
/* Connection lost? */
server->conn_error = result;
server->state = CONN_INVALID;
}
}
if (result != 1)
list_add_tail(&req->rq_queue, &server->xmitq);
smb_rget(req);
if (server->state != CONN_VALID)
smbiod_retry(server);
smb_unlock_server(server);
smbiod_wake_up();
timeleft = wait_event_interruptible_timeout(req->rq_wait,
req->rq_flags & SMB_REQ_RECEIVED, 30*HZ);
if (!timeleft || signal_pending(current)) {
/*
* On timeout or on interrupt we want to try and remove the
* request from the recvq/xmitq.
* First check if the request is still part of a queue. (May
* have been removed by some error condition)
*/
smb_lock_server(server);
if (!list_empty(&req->rq_queue)) {
list_del_init(&req->rq_queue);
smb_rput(req);
}
smb_unlock_server(server);
}
if (!timeleft) {
PARANOIA("request [%p, mid=%d] timed out!\n",
req, req->rq_mid);
VERBOSE("smb_com: %02x\n", *(req->rq_header + smb_com));
VERBOSE("smb_rcls: %02x\n", *(req->rq_header + smb_rcls));
VERBOSE("smb_flg: %02x\n", *(req->rq_header + smb_flg));
VERBOSE("smb_tid: %04x\n", WVAL(req->rq_header, smb_tid));
VERBOSE("smb_pid: %04x\n", WVAL(req->rq_header, smb_pid));
VERBOSE("smb_uid: %04x\n", WVAL(req->rq_header, smb_uid));
VERBOSE("smb_mid: %04x\n", WVAL(req->rq_header, smb_mid));
VERBOSE("smb_wct: %02x\n", *(req->rq_header + smb_wct));
req->rq_rcls = ERRSRV;
req->rq_err = ERRtimeout;
/* Just in case it was "stuck" */
smbiod_wake_up();
}
VERBOSE("woke up, rcls=%d\n", req->rq_rcls);
if (req->rq_rcls != 0)
req->rq_errno = smb_errno(req);
if (signal_pending(current))
req->rq_errno = -ERESTARTSYS;
return req->rq_errno;
}
/*
* Send a request and place it on the recvq if successfully sent.
* Must be called with the server lock held.
*/
static int smb_request_send_req(struct smb_request *req)
{
struct smb_sb_info *server = req->rq_server;
int result;
if (req->rq_bytes_sent == 0) {
WSET(req->rq_header, smb_tid, server->opt.tid);
WSET(req->rq_header, smb_pid, 1);
WSET(req->rq_header, smb_uid, server->opt.server_uid);
}
result = smb_send_request(req);
if (result < 0 && result != -EAGAIN)
goto out;
result = 0;
if (!(req->rq_flags & SMB_REQ_TRANSMITTED))
goto out;
list_move_tail(&req->rq_queue, &server->recvq);
result = 1;
out:
return result;
}
/*
* Sends one request for this server. (smbiod)
* Must be called with the server lock held.
* Returns: <0 on error
* 0 if no request could be completely sent
* 1 if all data for one request was sent
*/
int smb_request_send_server(struct smb_sb_info *server)
{
struct list_head *head;
struct smb_request *req;
int result;
if (server->state != CONN_VALID)
return 0;
/* dequeue first request, if any */
req = NULL;
head = server->xmitq.next;
if (head != &server->xmitq) {
req = list_entry(head, struct smb_request, rq_queue);
}
if (!req)
return 0;
result = smb_request_send_req(req);
if (result < 0) {
server->conn_error = result;
list_move(&req->rq_queue, &server->xmitq);
result = -EIO;
goto out;
}
out:
return result;
}
/*
* Try to find a request matching this "mid". Typically the first entry will
* be the matching one.
*/
static struct smb_request *find_request(struct smb_sb_info *server, int mid)
{
struct list_head *tmp;
struct smb_request *req = NULL;
list_for_each(tmp, &server->recvq) {
req = list_entry(tmp, struct smb_request, rq_queue);
if (req->rq_mid == mid) {
break;
}
req = NULL;
}
if (!req) {
VERBOSE("received reply with mid %d but no request!\n",
WVAL(server->header, smb_mid));
server->rstate = SMB_RECV_DROP;
}
return req;
}
/*
* Called when we have read the smb header and believe this is a response.
*/
static int smb_init_request(struct smb_sb_info *server, struct smb_request *req)
{
int hdrlen, wct;
memcpy(req->rq_header, server->header, SMB_HEADER_LEN);
wct = *(req->rq_header + smb_wct);
if (wct > 20) {
PARANOIA("wct too large, %d > 20\n", wct);
server->rstate = SMB_RECV_DROP;
return 0;
}
req->rq_resp_wct = wct;
hdrlen = SMB_HEADER_LEN + wct*2 + 2;
VERBOSE("header length: %d smb_wct: %2d\n", hdrlen, wct);
req->rq_bytes_recvd = SMB_HEADER_LEN;
req->rq_rlen = hdrlen;
req->rq_iov[0].iov_base = req->rq_header;
req->rq_iov[0].iov_len = hdrlen;
req->rq_iovlen = 1;
server->rstate = SMB_RECV_PARAM;
#ifdef SMB_DEBUG_PACKET_SIZE
add_recv_stats(smb_len(server->header));
#endif
return 0;
}
/*
* Reads the SMB parameters
*/
static int smb_recv_param(struct smb_sb_info *server, struct smb_request *req)
{
int result;
result = smb_receive(server, req);
if (result < 0)
return result;
if (req->rq_bytes_recvd < req->rq_rlen)
return 0;
VERBOSE("result: %d smb_bcc: %04x\n", result,
WVAL(req->rq_header, SMB_HEADER_LEN +
(*(req->rq_header + smb_wct) * 2)));
result = 0;
req->rq_iov[0].iov_base = NULL;
req->rq_rlen = 0;
if (req->rq_callback)
req->rq_callback(req);
else if (req->rq_setup_read)
result = req->rq_setup_read(req);
if (result < 0) {
server->rstate = SMB_RECV_DROP;
return result;
}
server->rstate = req->rq_rlen > 0 ? SMB_RECV_DATA : SMB_RECV_END;
req->rq_bytes_recvd = 0; // recvd out of the iov
VERBOSE("rlen: %d\n", req->rq_rlen);
if (req->rq_rlen < 0) {
PARANOIA("Parameters read beyond end of packet!\n");
server->rstate = SMB_RECV_END;
return -EIO;
}
return 0;
}
/*
* Reads the SMB data
*/
static int smb_recv_data(struct smb_sb_info *server, struct smb_request *req)
{
int result;
result = smb_receive(server, req);
if (result < 0)
goto out;
if (req->rq_bytes_recvd < req->rq_rlen)
goto out;
server->rstate = SMB_RECV_END;
out:
VERBOSE("result: %d\n", result);
return result;
}
/*
* Receive a transaction2 response
* Return: 0 if the response has been fully read
* 1 if there are further "fragments" to read
* <0 if there is an error
*/
static int smb_recv_trans2(struct smb_sb_info *server, struct smb_request *req)
{
unsigned char *inbuf;
unsigned int parm_disp, parm_offset, parm_count, parm_tot;
unsigned int data_disp, data_offset, data_count, data_tot;
int hdrlen = SMB_HEADER_LEN + req->rq_resp_wct*2 - 2;
VERBOSE("handling trans2\n");
inbuf = req->rq_header;
data_tot = WVAL(inbuf, smb_tdrcnt);
parm_tot = WVAL(inbuf, smb_tprcnt);
parm_disp = WVAL(inbuf, smb_prdisp);
parm_offset = WVAL(inbuf, smb_proff);
parm_count = WVAL(inbuf, smb_prcnt);
data_disp = WVAL(inbuf, smb_drdisp);
data_offset = WVAL(inbuf, smb_droff);
data_count = WVAL(inbuf, smb_drcnt);
/* Modify offset for the split header/buffer we use */
if (data_count || data_offset) {
if (unlikely(data_offset < hdrlen))
goto out_bad_data;
else
data_offset -= hdrlen;
}
if (parm_count || parm_offset) {
if (unlikely(parm_offset < hdrlen))
goto out_bad_parm;
else
parm_offset -= hdrlen;
}
if (parm_count == parm_tot && data_count == data_tot) {
/*
* This packet has all the trans2 data.
*
* We setup the request so that this will be the common
* case. It may be a server error to not return a
* response that fits.
*/
VERBOSE("single trans2 response "
"dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
data_count, parm_count,
data_offset, parm_offset);
req->rq_ldata = data_count;
req->rq_lparm = parm_count;
req->rq_data = req->rq_buffer + data_offset;
req->rq_parm = req->rq_buffer + parm_offset;
if (unlikely(parm_offset + parm_count > req->rq_rlen))
goto out_bad_parm;
if (unlikely(data_offset + data_count > req->rq_rlen))
goto out_bad_data;
return 0;
}
VERBOSE("multi trans2 response "
"frag=%d, dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
req->rq_fragment,
data_count, parm_count,
data_offset, parm_offset);
if (!req->rq_fragment) {
int buf_len;
/* We got the first trans2 fragment */
req->rq_fragment = 1;
req->rq_total_data = data_tot;
req->rq_total_parm = parm_tot;
req->rq_ldata = 0;
req->rq_lparm = 0;
buf_len = data_tot + parm_tot;
if (buf_len > SMB_MAX_PACKET_SIZE)
goto out_too_long;
req->rq_trans2bufsize = buf_len;
req->rq_trans2buffer = kzalloc(buf_len, GFP_NOFS);
if (!req->rq_trans2buffer)
goto out_no_mem;
req->rq_parm = req->rq_trans2buffer;
req->rq_data = req->rq_trans2buffer + parm_tot;
} else if (unlikely(req->rq_total_data < data_tot ||
req->rq_total_parm < parm_tot))
goto out_data_grew;
if (unlikely(parm_disp + parm_count > req->rq_total_parm ||
parm_offset + parm_count > req->rq_rlen))
goto out_bad_parm;
if (unlikely(data_disp + data_count > req->rq_total_data ||
data_offset + data_count > req->rq_rlen))
goto out_bad_data;
inbuf = req->rq_buffer;
memcpy(req->rq_parm + parm_disp, inbuf + parm_offset, parm_count);
memcpy(req->rq_data + data_disp, inbuf + data_offset, data_count);
req->rq_ldata += data_count;
req->rq_lparm += parm_count;
/*
* Check whether we've received all of the data. Note that
* we use the packet totals -- total lengths might shrink!
*/
if (req->rq_ldata >= data_tot && req->rq_lparm >= parm_tot) {
req->rq_ldata = data_tot;
req->rq_lparm = parm_tot;
return 0;
}
return 1;
out_too_long:
printk(KERN_ERR "smb_trans2: data/param too long, data=%u, parm=%u\n",
data_tot, parm_tot);
goto out_EIO;
out_no_mem:
printk(KERN_ERR "smb_trans2: couldn't allocate data area of %d bytes\n",
req->rq_trans2bufsize);
req->rq_errno = -ENOMEM;
goto out;
out_data_grew:
printk(KERN_ERR "smb_trans2: data/params grew!\n");
goto out_EIO;
out_bad_parm:
printk(KERN_ERR "smb_trans2: invalid parms, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
parm_disp, parm_count, parm_tot, parm_offset);
goto out_EIO;
out_bad_data:
printk(KERN_ERR "smb_trans2: invalid data, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
data_disp, data_count, data_tot, data_offset);
out_EIO:
req->rq_errno = -EIO;
out:
return req->rq_errno;
}
/*
* State machine for receiving responses. We handle the fact that we can't
* read the full response in one try by having states telling us how much we
* have read.
*
* Must be called with the server lock held (only called from smbiod).
*
* Return: <0 on error
*/
int smb_request_recv(struct smb_sb_info *server)
{
struct smb_request *req = NULL;
int result = 0;
if (smb_recv_available(server) <= 0)
return 0;
VERBOSE("state: %d\n", server->rstate);
switch (server->rstate) {
case SMB_RECV_DROP:
result = smb_receive_drop(server);
if (result < 0)
break;
if (server->rstate == SMB_RECV_DROP)
break;
server->rstate = SMB_RECV_START;
/* fallthrough */
case SMB_RECV_START:
server->smb_read = 0;
server->rstate = SMB_RECV_HEADER;
/* fallthrough */
case SMB_RECV_HEADER:
result = smb_receive_header(server);
if (result < 0)
break;
if (server->rstate == SMB_RECV_HEADER)
break;
if (! (*(server->header + smb_flg) & SMB_FLAGS_REPLY) ) {
server->rstate = SMB_RECV_REQUEST;
break;
}
if (server->rstate != SMB_RECV_HCOMPLETE)
break;
/* fallthrough */
case SMB_RECV_HCOMPLETE:
req = find_request(server, WVAL(server->header, smb_mid));
if (!req)
break;
smb_init_request(server, req);
req->rq_rcls = *(req->rq_header + smb_rcls);
req->rq_err = WVAL(req->rq_header, smb_err);
if (server->rstate != SMB_RECV_PARAM)
break;
/* fallthrough */
case SMB_RECV_PARAM:
if (!req)
req = find_request(server,WVAL(server->header,smb_mid));
if (!req)
break;
result = smb_recv_param(server, req);
if (result < 0)
break;
if (server->rstate != SMB_RECV_DATA)
break;
/* fallthrough */
case SMB_RECV_DATA:
if (!req)
req = find_request(server,WVAL(server->header,smb_mid));
if (!req)
break;
result = smb_recv_data(server, req);
if (result < 0)
break;
break;
/* We should never be called with any of these states */
case SMB_RECV_END:
case SMB_RECV_REQUEST:
BUG();
}
if (result < 0) {
/* We saw an error */
return result;
}
if (server->rstate != SMB_RECV_END)
return 0;
result = 0;
if (req->rq_trans2_command && req->rq_rcls == SUCCESS)
result = smb_recv_trans2(server, req);
/*
* Response completely read. Drop any extra bytes sent by the server.
* (Yes, servers sometimes add extra bytes to responses)
*/
VERBOSE("smb_len: %d smb_read: %d\n",
server->smb_len, server->smb_read);
if (server->smb_read < server->smb_len)
smb_receive_drop(server);
server->rstate = SMB_RECV_START;
if (!result) {
list_del_init(&req->rq_queue);
req->rq_flags |= SMB_REQ_RECEIVED;
smb_rput(req);
wake_up_interruptible(&req->rq_wait);
}
return 0;
}