connect.c

Linux内核自带的cifs模块

/*
 *   fs/cifs/connect.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2007
 *   Author(s): Steve French ([e-mail])
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <linux/fs.h>
#include <linux/net.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/ipv6.h>
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/version.h>
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0)
#include <linux/mempool.h>
#include <linux/pagevec.h>
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,19)
#include <linux/freezer.h>
#endif /* 2.6.19 */
#endif
#include <linux/kthread.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "ntlmssp.h"
#include "nterr.h"
#include "rfc1002pdu.h"
#include "cn_cifs.h"

#define CIFS_PORT 445
#define RFC1001_PORT 139

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 7)
#define sock_create_kern sock_create
#endif

static DECLARE_COMPLETION(cifsd_complete);

extern void SMBNTencrypt(unsigned char *passwd, unsigned char *c8,
			 unsigned char *p24);

#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0)
extern mempool_t *cifs_req_poolp;
#else /* old 2.4 kernel */
#ifndef PAGEVEC_SIZE
#define PAGEVEC_SIZE 14
#endif
#endif

struct smb_vol {
	char *username;
	char *password;
	char *domainname;
	char *UNC;
	char *UNCip;
	char *in6_addr;  /* ipv6 address as human readable form of in6_addr */
	char *iocharset;  /* local code page for mapping to and from Unicode */
	char source_rfc1001_name[16]; /* netbios name of client */
	char target_rfc1001_name[16]; /* netbios name of server for Win9x/ME */
	uid_t linux_uid;
	gid_t linux_gid;
	mode_t file_mode;
	mode_t dir_mode;
	unsigned secFlg;
	unsigned rw:1;
	unsigned retry:1;
	unsigned intr:1;
	unsigned setuids:1;
	unsigned override_uid:1;
	unsigned override_gid:1;
	unsigned noperm:1;
	unsigned no_psx_acl:1; /* set if posix acl support should be disabled */
	unsigned cifs_acl:1;
	unsigned no_xattr:1;   /* set if xattr (EA) support should be disabled*/
	unsigned server_ino:1; /* use inode numbers from server ie UniqueId */
	unsigned direct_io:1;
	unsigned remap:1;   /* set to remap seven reserved chars in filenames */
	unsigned posix_paths:1;   /* unset to not ask for posix pathnames. */
	unsigned no_linux_ext:1;
	unsigned sfu_emul:1;
	unsigned nullauth:1; /* attempt to authenticate with null user */
	unsigned nocase;     /* request case insensitive filenames */
	unsigned nobrl;      /* disable sending byte range locks to srv */
	unsigned int rsize;
	unsigned int wsize;
	unsigned int sockopt;
	unsigned short int port;
	char *prepath;
};

static int ipv4_connect(struct sockaddr_in *psin_server,
			struct socket **csocket,
			char *netb_name,
			char *server_netb_name);
static int ipv6_connect(struct sockaddr_in6 *psin_server,
			struct socket **csocket);


	/*
	 * cifs tcp session reconnection
	 *
	 * mark tcp session as reconnecting so temporarily locked
	 * mark all smb sessions as reconnecting for tcp session
	 * reconnect tcp session
	 * wake up waiters on reconnection? - (not needed currently)
	 */

static int
cifs_reconnect(struct TCP_Server_Info *server)
{
	int rc = 0;
	struct list_head *tmp;
	struct cifsSesInfo *ses;
	struct cifsTconInfo *tcon;
	struct mid_q_entry *mid_entry;

	spin_lock(&GlobalMid_Lock);
	if (kthread_should_stop()) {
		/* the demux thread will exit normally
		next time through the loop */
		spin_unlock(&GlobalMid_Lock);
		return rc;
	} else
		server->tcpStatus = CifsNeedReconnect;
	spin_unlock(&GlobalMid_Lock);
	server->maxBuf = 0;

	cFYI(1, ("Reconnecting tcp session"));

	/* before reconnecting the tcp session, mark the smb session (uid)
		and the tid bad so they are not used until reconnected */
	read_lock(&GlobalSMBSeslock);
	list_for_each(tmp, &GlobalSMBSessionList) {
		ses = list_entry(tmp, struct cifsSesInfo, cifsSessionList);
		if (ses->server) {
			if (ses->server == server) {
				ses->status = CifsNeedReconnect;
				ses->ipc_tid = 0;
			}
		}
		/* else tcp and smb sessions need reconnection */
	}
	list_for_each(tmp, &GlobalTreeConnectionList) {
		tcon = list_entry(tmp, struct cifsTconInfo, cifsConnectionList);
		if ((tcon) && (tcon->ses) && (tcon->ses->server == server))
			tcon->tidStatus = CifsNeedReconnect;
	}
	read_unlock(&GlobalSMBSeslock);
	/* do not want to be sending data on a socket we are freeing */
	down(&server->tcpSem);
	if (server->ssocket) {
		cFYI(1, ("State: 0x%x Flags: 0x%lx", server->ssocket->state,
			server->ssocket->flags));
		server->ssocket->ops->shutdown(server->ssocket, SEND_SHUTDOWN);
		cFYI(1, ("Post shutdown state: 0x%x Flags: 0x%lx",
			server->ssocket->state,
			server->ssocket->flags));
		sock_release(server->ssocket);
		server->ssocket = NULL;
	}

	spin_lock(&GlobalMid_Lock);
	list_for_each(tmp, &server->pending_mid_q) {
		mid_entry = list_entry(tmp, struct
					mid_q_entry,
					qhead);
		if (mid_entry) {
			if (mid_entry->midState == MID_REQUEST_SUBMITTED) {
				/* Mark other intransit requests as needing
				   retry so we do not immediately mark the
				   session bad again (ie after we reconnect
				   below) as they timeout too */
				mid_entry->midState = MID_RETRY_NEEDED;
			}
		}
	}
	spin_unlock(&GlobalMid_Lock);
	up(&server->tcpSem);

	while ((!kthread_should_stop()) && (server->tcpStatus != CifsGood)) {
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 12)
		try_to_freeze();
#endif
		if (server->protocolType == IPV6) {
			rc = ipv6_connect(&server->addr.sockAddr6,
					  &server->ssocket);
		} else {
			rc = ipv4_connect(&server->addr.sockAddr,
					&server->ssocket,
					server->workstation_RFC1001_name,
					server->server_RFC1001_name);
		}
		if (rc) {
			cFYI(1, ("reconnect error %d", rc));
			msleep(3000);
		} else {
			atomic_inc(&tcpSesReconnectCount);
			spin_lock(&GlobalMid_Lock);
			if (!kthread_should_stop())
				server->tcpStatus = CifsGood;
			server->sequence_number = 0;
			spin_unlock(&GlobalMid_Lock);
	/*		atomic_set(&server->inFlight,0);*/
			wake_up(&server->response_q);
		}
	}
	return rc;
}

/*
	return codes:
		0 	not a transact2, or all data present
		>0 	transact2 with that much data missing
		-EINVAL = invalid transact2

 */
static int check2ndT2(struct smb_hdr *pSMB, unsigned int maxBufSize)
{
	struct smb_t2_rsp *pSMBt;
	int total_data_size;
	int data_in_this_rsp;
	int remaining;

	if (pSMB->Command != SMB_COM_TRANSACTION2)
		return 0;

	/* check for plausible wct, bcc and t2 data and parm sizes */
	/* check for parm and data offset going beyond end of smb */
	if (pSMB->WordCount != 10) { /* coalesce_t2 depends on this */
		cFYI(1, ("invalid transact2 word count"));
		return -EINVAL;
	}

	pSMBt = (struct smb_t2_rsp *)pSMB;

	total_data_size = le16_to_cpu(pSMBt->t2_rsp.TotalDataCount);
	data_in_this_rsp = le16_to_cpu(pSMBt->t2_rsp.DataCount);

	remaining = total_data_size - data_in_this_rsp;

	if (remaining == 0)
		return 0;
	else if (remaining < 0) {
		cFYI(1, ("total data %d smaller than data in frame %d",
			total_data_size, data_in_this_rsp));
		return -EINVAL;
	} else {
		cFYI(1, ("missing %d bytes from transact2, check next response",
			remaining));
		if (total_data_size > maxBufSize) {
			cERROR(1, ("TotalDataSize %d is over maximum buffer %d",
				total_data_size, maxBufSize));
			return -EINVAL;
		}
		return remaining;
	}
}

static int coalesce_t2(struct smb_hdr *psecond, struct smb_hdr *pTargetSMB)
{
	struct smb_t2_rsp *pSMB2 = (struct smb_t2_rsp *)psecond;
	struct smb_t2_rsp *pSMBt  = (struct smb_t2_rsp *)pTargetSMB;
	int total_data_size;
	int total_in_buf;
	int remaining;
	int total_in_buf2;
	char *data_area_of_target;
	char *data_area_of_buf2;
	__u16 byte_count;

	total_data_size = le16_to_cpu(pSMBt->t2_rsp.TotalDataCount);

	if (total_data_size != le16_to_cpu(pSMB2->t2_rsp.TotalDataCount)) {
		cFYI(1, ("total data size of primary and secondary t2 differ"));
	}

	total_in_buf = le16_to_cpu(pSMBt->t2_rsp.DataCount);

	remaining = total_data_size - total_in_buf;

	if (remaining < 0)
		return -EINVAL;

	if (remaining == 0) /* nothing to do, ignore */
		return 0;

	total_in_buf2 = le16_to_cpu(pSMB2->t2_rsp.DataCount);
	if (remaining < total_in_buf2) {
		cFYI(1, ("transact2 2nd response contains too much data"));
	}

	/* find end of first SMB data area */
	data_area_of_target = (char *)&pSMBt->hdr.Protocol +
				le16_to_cpu(pSMBt->t2_rsp.DataOffset);
	/* validate target area */

	data_area_of_buf2 = (char *) &pSMB2->hdr.Protocol +
					le16_to_cpu(pSMB2->t2_rsp.DataOffset);

	data_area_of_target += total_in_buf;

	/* copy second buffer into end of first buffer */
	memcpy(data_area_of_target, data_area_of_buf2, total_in_buf2);
	total_in_buf += total_in_buf2;
	pSMBt->t2_rsp.DataCount = cpu_to_le16(total_in_buf);
	byte_count = le16_to_cpu(BCC_LE(pTargetSMB));
	byte_count += total_in_buf2;
	BCC_LE(pTargetSMB) = cpu_to_le16(byte_count);

	byte_count = pTargetSMB->smb_buf_length;
	byte_count += total_in_buf2;

	/* BB also add check that we are not beyond maximum buffer size */

	pTargetSMB->smb_buf_length = byte_count;

	if (remaining == total_in_buf2) {
		cFYI(1, ("found the last secondary response"));
		return 0; /* we are done */
	} else /* more responses to go */
		return 1;

}

static int
cifs_demultiplex_thread(struct TCP_Server_Info *server)
{
	int length;
	unsigned int pdu_length, total_read;
	struct smb_hdr *smb_buffer = NULL;
	struct smb_hdr *bigbuf = NULL;
	struct smb_hdr *smallbuf = NULL;
	struct msghdr smb_msg;
	struct kvec iov;
	struct socket *csocket = server->ssocket;
	struct list_head *tmp;
	struct cifsSesInfo *ses;
	struct task_struct *task_to_wake = NULL;
	struct mid_q_entry *mid_entry;
	char temp;
	int isLargeBuf = FALSE;
	int isMultiRsp;
	int reconnect;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 8)
	mm_segment_t temp_fs;
#endif

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 5, 0)
	daemonize();
	sprintf(current->comm,"cifsd");
#endif

	current->flags |= PF_MEMALLOC;
	server->tsk = current;	/* save process info to wake at shutdown */
	cFYI(1, ("Demultiplex PID: %d", current->pid));
	write_lock(&GlobalSMBSeslock);
	atomic_inc(&tcpSesAllocCount);
	length = tcpSesAllocCount.counter;
	write_unlock(&GlobalSMBSeslock);
	complete(&cifsd_complete);
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 10)
	if (length  > 1)
		mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
				GFP_KERNEL);
#endif

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 8)
	temp_fs = get_fs();	/* we must turn off socket api parm checking */
	set_fs(get_ds());
#elif LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 22)
	set_freezable();
#endif

	while (!kthread_should_stop()) {
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 12)
		if (try_to_freeze())
			continue;
#endif
		if (bigbuf == NULL) {
			bigbuf = cifs_buf_get();
			if (!bigbuf) {
				cERROR(1, ("No memory for large SMB response"));
				msleep(3000);
				/* retry will check if exiting */
				continue;
			}
		} else if (isLargeBuf) {
			/* we are reusing a dirty large buf, clear its start */
			memset(bigbuf, 0, sizeof(struct smb_hdr));
		}

		if (smallbuf == NULL) {
			smallbuf = cifs_small_buf_get();
			if (!smallbuf) {
				cERROR(1, ("No memory for SMB response"));
				msleep(1000);
				/* retry will check if exiting */
				continue;
			}
			/* beginning of smb buffer is cleared in our buf_get */
		} else /* if existing small buf clear beginning */
			memset(smallbuf, 0, sizeof(struct smb_hdr));

		isLargeBuf = FALSE;
		isMultiRsp = FALSE;
		smb_buffer = smallbuf;
		iov.iov_base = smb_buffer;
		iov.iov_len = 4;
		smb_msg.msg_control = NULL;