From 2c8f981d93f830c167c811f046b5107cc24b6e1b Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Thu, 19 May 2011 16:22:52 -0400 Subject: [PATCH] cifs: consolidate SendReceive response checks Further consolidate the SendReceive code by moving the checks run over the packet into a separate function that all the SendReceive variants can call. We can also eliminate the check for a receive_len that's too big or too small. cifs_demultiplex_thread already checks that and disconnects the socket if that occurs, while setting the midStatus to MALFORMED. It'll never call this code if that's the case. Finally do a little cleanup. Use "goto out" on errors so that the flow of code in the normal case is more evident. Also switch the logErr variable in map_smb_to_linux_error to a bool. Reviewed-by: Pavel Shilovsky Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifsproto.h | 4 +- fs/cifs/netmisc.c | 2 +- fs/cifs/transport.c | 157 ++++++++++++-------------------------------- 3 files changed, 45 insertions(+), 118 deletions(-) diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index 6e69e06a30b..7aa13111288 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -76,6 +76,8 @@ extern int SendReceive(const unsigned int /* xid */ , struct cifsSesInfo *, int * /* bytes returned */ , const int long_op); extern int SendReceiveNoRsp(const unsigned int xid, struct cifsSesInfo *ses, struct smb_hdr *in_buf, int flags); +extern int cifs_check_receive(struct mid_q_entry *mid, + struct TCP_Server_Info *server, bool log_error); extern int SendReceive2(const unsigned int /* xid */ , struct cifsSesInfo *, struct kvec *, int /* nvec to send */, int * /* type of buf returned */ , const int flags); @@ -99,7 +101,7 @@ extern int cifs_convert_address(struct sockaddr *dst, const char *src, int len); extern int cifs_set_port(struct sockaddr *addr, const unsigned short int port); extern int cifs_fill_sockaddr(struct sockaddr *dst, const char *src, int len, const unsigned short int port); -extern int map_smb_to_linux_error(struct smb_hdr *smb, int logErr); +extern int map_smb_to_linux_error(struct smb_hdr *smb, bool logErr); extern void header_assemble(struct smb_hdr *, char /* command */ , const struct cifsTconInfo *, int /* length of fixed section (word count) in two byte units */); diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c index 79b71c2c7c9..73e47e84b61 100644 --- a/fs/cifs/netmisc.c +++ b/fs/cifs/netmisc.c @@ -836,7 +836,7 @@ ntstatus_to_dos(__u32 ntstatus, __u8 *eclass, __u16 *ecode) } int -map_smb_to_linux_error(struct smb_hdr *smb, int logErr) +map_smb_to_linux_error(struct smb_hdr *smb, bool logErr) { unsigned int i; int rc = -EIO; /* if transport error smb error may not be set */ diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index f2513fb8c39..43633a79942 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -501,6 +501,25 @@ send_nt_cancel(struct TCP_Server_Info *server, struct smb_hdr *in_buf, return rc; } +int +cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server, + bool log_error) +{ + dump_smb(mid->resp_buf, + min_t(u32, 92, be32_to_cpu(mid->resp_buf->smb_buf_length))); + + /* convert the length into a more usable form */ + if (server->secMode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) { + /* FIXME: add code to kill session */ + if (cifs_verify_signature(mid->resp_buf, server, + mid->sequence_number + 1) != 0) + cERROR(1, "Unexpected SMB signature"); + } + + /* BB special case reconnect tid and uid here? */ + return map_smb_to_linux_error(mid->resp_buf, log_error); +} + int SendReceive2(const unsigned int xid, struct cifsSesInfo *ses, struct kvec *iov, int n_vec, int *pRespBufType /* ret */, @@ -508,7 +527,6 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo *ses, { int rc = 0; int long_op; - unsigned int receive_len; struct mid_q_entry *midQ; struct smb_hdr *in_buf = iov[0].iov_base; @@ -605,54 +623,24 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo *ses, return rc; } - receive_len = be32_to_cpu(midQ->resp_buf->smb_buf_length); - - if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) { - cERROR(1, "Frame too large received. Length: %d Xid: %d", - receive_len, xid); + if (!midQ->resp_buf || midQ->midState != MID_RESPONSE_RECEIVED) { rc = -EIO; + cFYI(1, "Bad MID state?"); goto out; } - /* rcvd frame is ok */ + iov[0].iov_base = (char *)midQ->resp_buf; + iov[0].iov_len = be32_to_cpu(midQ->resp_buf->smb_buf_length) + 4; + if (midQ->largeBuf) + *pRespBufType = CIFS_LARGE_BUFFER; + else + *pRespBufType = CIFS_SMALL_BUFFER; - if (midQ->resp_buf && - (midQ->midState == MID_RESPONSE_RECEIVED)) { - - iov[0].iov_base = (char *)midQ->resp_buf; - if (midQ->largeBuf) - *pRespBufType = CIFS_LARGE_BUFFER; - else - *pRespBufType = CIFS_SMALL_BUFFER; - iov[0].iov_len = receive_len + 4; - - dump_smb(midQ->resp_buf, 80); - /* convert the length into a more usable form */ - if ((receive_len > 24) && - (ses->server->secMode & (SECMODE_SIGN_REQUIRED | - SECMODE_SIGN_ENABLED))) { - rc = cifs_verify_signature(midQ->resp_buf, - ses->server, - midQ->sequence_number+1); - if (rc) { - cERROR(1, "Unexpected SMB signature"); - /* BB FIXME add code to kill session */ - } - } - - /* BB special case reconnect tid and uid here? */ - rc = map_smb_to_linux_error(midQ->resp_buf, - flags & CIFS_LOG_ERROR); - - if ((flags & CIFS_NO_RESP) == 0) - midQ->resp_buf = NULL; /* mark it so buf will - not be freed by - delete_mid */ - } else { - rc = -EIO; - cFYI(1, "Bad MID state?"); - } + rc = cifs_check_receive(midQ, ses->server, flags & CIFS_LOG_ERROR); + /* mark it so buf will not be freed by delete_mid */ + if ((flags & CIFS_NO_RESP) == 0) + midQ->resp_buf = NULL; out: delete_mid(midQ); atomic_dec(&ses->server->inFlight); @@ -667,7 +655,6 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses, int *pbytes_returned, const int long_op) { int rc = 0; - unsigned int receive_len; struct mid_q_entry *midQ; if (ses == NULL) { @@ -757,47 +744,16 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses, return rc; } - receive_len = be32_to_cpu(midQ->resp_buf->smb_buf_length); - - if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) { - cERROR(1, "Frame too large received. Length: %d Xid: %d", - receive_len, xid); + if (!midQ->resp_buf || !out_buf || + midQ->midState != MID_RESPONSE_RECEIVED) { rc = -EIO; + cERROR(1, "Bad MID state?"); goto out; } - /* rcvd frame is ok */ - - if (midQ->resp_buf && out_buf - && (midQ->midState == MID_RESPONSE_RECEIVED)) { - out_buf->smb_buf_length = cpu_to_be32(receive_len); - memcpy((char *)out_buf + 4, - (char *)midQ->resp_buf + 4, - receive_len); - - dump_smb(out_buf, 92); - /* convert the length into a more usable form */ - if ((receive_len > 24) && - (ses->server->secMode & (SECMODE_SIGN_REQUIRED | - SECMODE_SIGN_ENABLED))) { - rc = cifs_verify_signature(out_buf, - ses->server, - midQ->sequence_number+1); - if (rc) { - cERROR(1, "Unexpected SMB signature"); - /* BB FIXME add code to kill session */ - } - } - - *pbytes_returned = be32_to_cpu(out_buf->smb_buf_length); - - /* BB special case reconnect tid and uid here? */ - rc = map_smb_to_linux_error(out_buf, 0 /* no log */ ); - } else { - rc = -EIO; - cERROR(1, "Bad MID state?"); - } - + *pbytes_returned = be32_to_cpu(midQ->resp_buf->smb_buf_length); + memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4); + rc = cifs_check_receive(midQ, ses->server, 0); out: delete_mid(midQ); atomic_dec(&ses->server->inFlight); @@ -838,7 +794,6 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, { int rc = 0; int rstart = 0; - unsigned int receive_len; struct mid_q_entry *midQ; struct cifsSesInfo *ses; @@ -961,46 +916,16 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, if (rc != 0) return rc; - receive_len = be32_to_cpu(midQ->resp_buf->smb_buf_length); - if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) { - cERROR(1, "Frame too large received. Length: %d Xid: %d", - receive_len, xid); - rc = -EIO; - goto out; - } - /* rcvd frame is ok */ - - if ((out_buf == NULL) || (midQ->midState != MID_RESPONSE_RECEIVED)) { + if (out_buf == NULL || midQ->midState != MID_RESPONSE_RECEIVED) { rc = -EIO; cERROR(1, "Bad MID state?"); goto out; } - out_buf->smb_buf_length = cpu_to_be32(receive_len); - memcpy((char *)out_buf + 4, - (char *)midQ->resp_buf + 4, - receive_len); - - dump_smb(out_buf, 92); - /* convert the length into a more usable form */ - if ((receive_len > 24) && - (ses->server->secMode & (SECMODE_SIGN_REQUIRED | - SECMODE_SIGN_ENABLED))) { - rc = cifs_verify_signature(out_buf, - ses->server, - midQ->sequence_number+1); - if (rc) { - cERROR(1, "Unexpected SMB signature"); - /* BB FIXME add code to kill session */ - } - } - - *pbytes_returned = be32_to_cpu(out_buf->smb_buf_length); - - /* BB special case reconnect tid and uid here? */ - rc = map_smb_to_linux_error(out_buf, 0 /* no log */ ); - + *pbytes_returned = be32_to_cpu(midQ->resp_buf->smb_buf_length); + memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4); + rc = cifs_check_receive(midQ, ses->server, 0); out: delete_mid(midQ); if (rstart && rc == -EACCES)