diff options
Diffstat (limited to 'fs/cifs/smb2transport.c')
| -rw-r--r-- | fs/cifs/smb2transport.c | 607 | 
1 files changed, 607 insertions, 0 deletions
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c new file mode 100644 index 00000000000..59c748ce872 --- /dev/null +++ b/fs/cifs/smb2transport.c @@ -0,0 +1,607 @@ +/* + *   fs/cifs/smb2transport.c + * + *   Copyright (C) International Business Machines  Corp., 2002, 2011 + *                 Etersoft, 2012 + *   Author(s): Steve French (sfrench@us.ibm.com) + *              Jeremy Allison (jra@samba.org) 2006 + *              Pavel Shilovsky (pshilovsky@samba.org) 2012 + * + *   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/list.h> +#include <linux/wait.h> +#include <linux/net.h> +#include <linux/delay.h> +#include <linux/uaccess.h> +#include <asm/processor.h> +#include <linux/mempool.h> +#include <linux/highmem.h> +#include "smb2pdu.h" +#include "cifsglob.h" +#include "cifsproto.h" +#include "smb2proto.h" +#include "cifs_debug.h" +#include "smb2status.h" +#include "smb2glob.h" + +static int +smb2_crypto_shash_allocate(struct TCP_Server_Info *server) +{ +	int rc; +	unsigned int size; + +	if (server->secmech.sdeschmacsha256 != NULL) +		return 0; /* already allocated */ + +	server->secmech.hmacsha256 = crypto_alloc_shash("hmac(sha256)", 0, 0); +	if (IS_ERR(server->secmech.hmacsha256)) { +		cifs_dbg(VFS, "could not allocate crypto hmacsha256\n"); +		rc = PTR_ERR(server->secmech.hmacsha256); +		server->secmech.hmacsha256 = NULL; +		return rc; +	} + +	size = sizeof(struct shash_desc) + +			crypto_shash_descsize(server->secmech.hmacsha256); +	server->secmech.sdeschmacsha256 = kmalloc(size, GFP_KERNEL); +	if (!server->secmech.sdeschmacsha256) { +		crypto_free_shash(server->secmech.hmacsha256); +		server->secmech.hmacsha256 = NULL; +		return -ENOMEM; +	} +	server->secmech.sdeschmacsha256->shash.tfm = server->secmech.hmacsha256; +	server->secmech.sdeschmacsha256->shash.flags = 0x0; + +	return 0; +} + +static int +smb3_crypto_shash_allocate(struct TCP_Server_Info *server) +{ +	unsigned int size; +	int rc; + +	if (server->secmech.sdesccmacaes != NULL) +		return 0;  /* already allocated */ + +	rc = smb2_crypto_shash_allocate(server); +	if (rc) +		return rc; + +	server->secmech.cmacaes = crypto_alloc_shash("cmac(aes)", 0, 0); +	if (IS_ERR(server->secmech.cmacaes)) { +		cifs_dbg(VFS, "could not allocate crypto cmac-aes"); +		kfree(server->secmech.sdeschmacsha256); +		server->secmech.sdeschmacsha256 = NULL; +		crypto_free_shash(server->secmech.hmacsha256); +		server->secmech.hmacsha256 = NULL; +		rc = PTR_ERR(server->secmech.cmacaes); +		server->secmech.cmacaes = NULL; +		return rc; +	} + +	size = sizeof(struct shash_desc) + +			crypto_shash_descsize(server->secmech.cmacaes); +	server->secmech.sdesccmacaes = kmalloc(size, GFP_KERNEL); +	if (!server->secmech.sdesccmacaes) { +		cifs_dbg(VFS, "%s: Can't alloc cmacaes\n", __func__); +		kfree(server->secmech.sdeschmacsha256); +		server->secmech.sdeschmacsha256 = NULL; +		crypto_free_shash(server->secmech.hmacsha256); +		crypto_free_shash(server->secmech.cmacaes); +		server->secmech.hmacsha256 = NULL; +		server->secmech.cmacaes = NULL; +		return -ENOMEM; +	} +	server->secmech.sdesccmacaes->shash.tfm = server->secmech.cmacaes; +	server->secmech.sdesccmacaes->shash.flags = 0x0; + +	return 0; +} + +static struct cifs_ses * +smb2_find_smb_ses(struct smb2_hdr *smb2hdr, struct TCP_Server_Info *server) +{ +	struct cifs_ses *ses; + +	spin_lock(&cifs_tcp_ses_lock); +	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { +		if (ses->Suid != smb2hdr->SessionId) +			continue; +		spin_unlock(&cifs_tcp_ses_lock); +		return ses; +	} +	spin_unlock(&cifs_tcp_ses_lock); + +	return NULL; +} + + +int +smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) +{ +	int i, rc; +	unsigned char smb2_signature[SMB2_HMACSHA256_SIZE]; +	unsigned char *sigptr = smb2_signature; +	struct kvec *iov = rqst->rq_iov; +	int n_vec = rqst->rq_nvec; +	struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base; +	struct cifs_ses *ses; + +	ses = smb2_find_smb_ses(smb2_pdu, server); +	if (!ses) { +		cifs_dbg(VFS, "%s: Could not find session\n", __func__); +		return 0; +	} + +	memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE); +	memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE); + +	rc = smb2_crypto_shash_allocate(server); +	if (rc) { +		cifs_dbg(VFS, "%s: shah256 alloc failed\n", __func__); +		return rc; +	} + +	rc = crypto_shash_setkey(server->secmech.hmacsha256, +		ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not update with response\n", __func__); +		return rc; +	} + +	rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not init sha256", __func__); +		return rc; +	} + +	for (i = 0; i < n_vec; i++) { +		if (iov[i].iov_len == 0) +			continue; +		if (iov[i].iov_base == NULL) { +			cifs_dbg(VFS, "null iovec entry\n"); +			return -EIO; +		} +		/* +		 * The first entry includes a length field (which does not get +		 * signed that occupies the first 4 bytes before the header). +		 */ +		if (i == 0) { +			if (iov[0].iov_len <= 8) /* cmd field at offset 9 */ +				break; /* nothing to sign or corrupt header */ +			rc = +			crypto_shash_update( +				&server->secmech.sdeschmacsha256->shash, +				iov[i].iov_base + 4, iov[i].iov_len - 4); +		} else { +			rc = +			crypto_shash_update( +				&server->secmech.sdeschmacsha256->shash, +				iov[i].iov_base, iov[i].iov_len); +		} +		if (rc) { +			cifs_dbg(VFS, "%s: Could not update with payload\n", +				 __func__); +			return rc; +		} +	} + +	/* now hash over the rq_pages array */ +	for (i = 0; i < rqst->rq_npages; i++) { +		struct kvec p_iov; + +		cifs_rqst_page_to_kvec(rqst, i, &p_iov); +		crypto_shash_update(&server->secmech.sdeschmacsha256->shash, +					p_iov.iov_base, p_iov.iov_len); +		kunmap(rqst->rq_pages[i]); +	} + +	rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash, +				sigptr); +	if (rc) +		cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__); + +	memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE); + +	return rc; +} + +int +generate_smb3signingkey(struct cifs_ses *ses) +{ +	unsigned char zero = 0x0; +	__u8 i[4] = {0, 0, 0, 1}; +	__u8 L[4] = {0, 0, 0, 128}; +	int rc = 0; +	unsigned char prfhash[SMB2_HMACSHA256_SIZE]; +	unsigned char *hashptr = prfhash; + +	memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE); +	memset(ses->smb3signingkey, 0x0, SMB3_SIGNKEY_SIZE); + +	rc = smb3_crypto_shash_allocate(ses->server); +	if (rc) { +		cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__); +		goto smb3signkey_ret; +	} + +	rc = crypto_shash_setkey(ses->server->secmech.hmacsha256, +		ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not set with session key\n", __func__); +		goto smb3signkey_ret; +	} + +	rc = crypto_shash_init(&ses->server->secmech.sdeschmacsha256->shash); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__); +		goto smb3signkey_ret; +	} + +	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash, +				i, 4); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not update with n\n", __func__); +		goto smb3signkey_ret; +	} + +	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash, +				"SMB2AESCMAC", 12); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not update with label\n", __func__); +		goto smb3signkey_ret; +	} + +	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash, +				&zero, 1); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not update with zero\n", __func__); +		goto smb3signkey_ret; +	} + +	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash, +				"SmbSign", 8); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not update with context\n", __func__); +		goto smb3signkey_ret; +	} + +	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash, +				L, 4); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not update with L\n", __func__); +		goto smb3signkey_ret; +	} + +	rc = crypto_shash_final(&ses->server->secmech.sdeschmacsha256->shash, +				hashptr); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__); +		goto smb3signkey_ret; +	} + +	memcpy(ses->smb3signingkey, hashptr, SMB3_SIGNKEY_SIZE); + +smb3signkey_ret: +	return rc; +} + +int +smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) +{ +	int i; +	int rc = 0; +	unsigned char smb3_signature[SMB2_CMACAES_SIZE]; +	unsigned char *sigptr = smb3_signature; +	struct kvec *iov = rqst->rq_iov; +	int n_vec = rqst->rq_nvec; +	struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base; +	struct cifs_ses *ses; + +	ses = smb2_find_smb_ses(smb2_pdu, server); +	if (!ses) { +		cifs_dbg(VFS, "%s: Could not find session\n", __func__); +		return 0; +	} + +	memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE); +	memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE); + +	rc = crypto_shash_setkey(server->secmech.cmacaes, +		ses->smb3signingkey, SMB2_CMACAES_SIZE); + +	if (rc) { +		cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__); +		return rc; +	} + +	/* +	 * we already allocate sdesccmacaes when we init smb3 signing key, +	 * so unlike smb2 case we do not have to check here if secmech are +	 * initialized +	 */ +	rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash); +	if (rc) { +		cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__); +		return rc; +	} + +	for (i = 0; i < n_vec; i++) { +		if (iov[i].iov_len == 0) +			continue; +		if (iov[i].iov_base == NULL) { +			cifs_dbg(VFS, "null iovec entry"); +			return -EIO; +		} +		/* +		 * The first entry includes a length field (which does not get +		 * signed that occupies the first 4 bytes before the header). +		 */ +		if (i == 0) { +			if (iov[0].iov_len <= 8) /* cmd field at offset 9 */ +				break; /* nothing to sign or corrupt header */ +			rc = +			crypto_shash_update( +				&server->secmech.sdesccmacaes->shash, +				iov[i].iov_base + 4, iov[i].iov_len - 4); +		} else { +			rc = +			crypto_shash_update( +				&server->secmech.sdesccmacaes->shash, +				iov[i].iov_base, iov[i].iov_len); +		} +		if (rc) { +			cifs_dbg(VFS, "%s: Couldn't update cmac aes with payload\n", +							__func__); +			return rc; +		} +	} + +	/* now hash over the rq_pages array */ +	for (i = 0; i < rqst->rq_npages; i++) { +		struct kvec p_iov; + +		cifs_rqst_page_to_kvec(rqst, i, &p_iov); +		crypto_shash_update(&server->secmech.sdesccmacaes->shash, +					p_iov.iov_base, p_iov.iov_len); +		kunmap(rqst->rq_pages[i]); +	} + +	rc = crypto_shash_final(&server->secmech.sdesccmacaes->shash, +						sigptr); +	if (rc) +		cifs_dbg(VFS, "%s: Could not generate cmac aes\n", __func__); + +	memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE); + +	return rc; +} + +/* must be called with server->srv_mutex held */ +static int +smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server) +{ +	int rc = 0; +	struct smb2_hdr *smb2_pdu = rqst->rq_iov[0].iov_base; + +	if (!(smb2_pdu->Flags & SMB2_FLAGS_SIGNED) || +	    server->tcpStatus == CifsNeedNegotiate) +		return rc; + +	if (!server->session_estab) { +		strncpy(smb2_pdu->Signature, "BSRSPYL", 8); +		return rc; +	} + +	rc = server->ops->calc_signature(rqst, server); + +	return rc; +} + +int +smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) +{ +	unsigned int rc; +	char server_response_sig[16]; +	struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)rqst->rq_iov[0].iov_base; + +	if ((smb2_pdu->Command == SMB2_NEGOTIATE) || +	    (smb2_pdu->Command == SMB2_SESSION_SETUP) || +	    (smb2_pdu->Command == SMB2_OPLOCK_BREAK) || +	    (!server->session_estab)) +		return 0; + +	/* +	 * BB what if signatures are supposed to be on for session but +	 * server does not send one? BB +	 */ + +	/* Do not need to verify session setups with signature "BSRSPYL " */ +	if (memcmp(smb2_pdu->Signature, "BSRSPYL ", 8) == 0) +		cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n", +			 smb2_pdu->Command); + +	/* +	 * Save off the origiginal signature so we can modify the smb and check +	 * our calculated signature against what the server sent. +	 */ +	memcpy(server_response_sig, smb2_pdu->Signature, SMB2_SIGNATURE_SIZE); + +	memset(smb2_pdu->Signature, 0, SMB2_SIGNATURE_SIZE); + +	mutex_lock(&server->srv_mutex); +	rc = server->ops->calc_signature(rqst, server); +	mutex_unlock(&server->srv_mutex); + +	if (rc) +		return rc; + +	if (memcmp(server_response_sig, smb2_pdu->Signature, +		   SMB2_SIGNATURE_SIZE)) +		return -EACCES; +	else +		return 0; +} + +/* + * Set message id for the request. Should be called after wait_for_free_request + * and when srv_mutex is held. + */ +static inline void +smb2_seq_num_into_buf(struct TCP_Server_Info *server, struct smb2_hdr *hdr) +{ +	hdr->MessageId = get_next_mid64(server); +} + +static struct mid_q_entry * +smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer, +		     struct TCP_Server_Info *server) +{ +	struct mid_q_entry *temp; + +	if (server == NULL) { +		cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n"); +		return NULL; +	} + +	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS); +	if (temp == NULL) +		return temp; +	else { +		memset(temp, 0, sizeof(struct mid_q_entry)); +		temp->mid = smb_buffer->MessageId;	/* always LE */ +		temp->pid = current->pid; +		temp->command = smb_buffer->Command;	/* Always LE */ +		temp->when_alloc = jiffies; +		temp->server = server; + +		/* +		 * The default is for the mid to be synchronous, so the +		 * default callback just wakes up the current task. +		 */ +		temp->callback = cifs_wake_up_task; +		temp->callback_data = current; +	} + +	atomic_inc(&midCount); +	temp->mid_state = MID_REQUEST_ALLOCATED; +	return temp; +} + +static int +smb2_get_mid_entry(struct cifs_ses *ses, struct smb2_hdr *buf, +		   struct mid_q_entry **mid) +{ +	if (ses->server->tcpStatus == CifsExiting) +		return -ENOENT; + +	if (ses->server->tcpStatus == CifsNeedReconnect) { +		cifs_dbg(FYI, "tcp session dead - return to caller to retry\n"); +		return -EAGAIN; +	} + +	if (ses->status == CifsNew) { +		if ((buf->Command != SMB2_SESSION_SETUP) && +		    (buf->Command != SMB2_NEGOTIATE)) +			return -EAGAIN; +		/* else ok - we are setting up session */ +	} + +	if (ses->status == CifsExiting) { +		if (buf->Command != SMB2_LOGOFF) +			return -EAGAIN; +		/* else ok - we are shutting down the session */ +	} + +	*mid = smb2_mid_entry_alloc(buf, ses->server); +	if (*mid == NULL) +		return -ENOMEM; +	spin_lock(&GlobalMid_Lock); +	list_add_tail(&(*mid)->qhead, &ses->server->pending_mid_q); +	spin_unlock(&GlobalMid_Lock); +	return 0; +} + +int +smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server, +		   bool log_error) +{ +	unsigned int len = get_rfc1002_length(mid->resp_buf); +	struct kvec iov; +	struct smb_rqst rqst = { .rq_iov = &iov, +				 .rq_nvec = 1 }; + +	iov.iov_base = (char *)mid->resp_buf; +	iov.iov_len = get_rfc1002_length(mid->resp_buf) + 4; + +	dump_smb(mid->resp_buf, min_t(u32, 80, len)); +	/* convert the length into a more usable form */ +	if (len > 24 && server->sign) { +		int rc; + +		rc = smb2_verify_signature(&rqst, server); +		if (rc) +			cifs_dbg(VFS, "SMB signature verification returned error = %d\n", +				 rc); +	} + +	return map_smb2_to_linux_error(mid->resp_buf, log_error); +} + +struct mid_q_entry * +smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst) +{ +	int rc; +	struct smb2_hdr *hdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base; +	struct mid_q_entry *mid; + +	smb2_seq_num_into_buf(ses->server, hdr); + +	rc = smb2_get_mid_entry(ses, hdr, &mid); +	if (rc) +		return ERR_PTR(rc); +	rc = smb2_sign_rqst(rqst, ses->server); +	if (rc) { +		cifs_delete_mid(mid); +		return ERR_PTR(rc); +	} +	return mid; +} + +struct mid_q_entry * +smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst) +{ +	int rc; +	struct smb2_hdr *hdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base; +	struct mid_q_entry *mid; + +	smb2_seq_num_into_buf(server, hdr); + +	mid = smb2_mid_entry_alloc(hdr, server); +	if (mid == NULL) +		return ERR_PTR(-ENOMEM); + +	rc = smb2_sign_rqst(rqst, server); +	if (rc) { +		DeleteMidQEntry(mid); +		return ERR_PTR(rc); +	} + +	return mid; +}  | 
