Move several code blocks to separate functions:
1) buffer allocations,
2) rfc1002 header check,
3) read whole smb message from socket,
4) find mid owner.
Signed-off-by: Pavel Shilovsky <piastry@xxxxxxxxx>
---
fs/cifs/cifs_debug.c | 1 -
fs/cifs/connect.c | 440 ++++++++++++++++++++++++++++----------------------
2 files changed, 247 insertions(+), 194 deletions(-)
diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 2fe3cf1..c4fc68a 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -66,7 +66,6 @@ void cifs_dump_detail(struct smb_hdr *smb)
cERROR(1, "smb buf %p len %d", smb, smbCalcSize(smb));
}
-
void cifs_dump_mids(struct TCP_Server_Info *server)
{
struct list_head *tmp;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index fb31c2c..23addcb 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -317,24 +317,234 @@ requeue_echo:
queue_delayed_work(system_nrt_wq, &server->echo, SMB_ECHO_INTERVAL);
}
+static struct mid_q_entry *
+find_cifs_owner(struct TCP_Server_Info *server, struct smb_hdr *buf,
+ int *length, bool isLargeBuf, bool *isMultiRsp, char **pbigbuf)
+{
+ struct list_head *tmp, *tmp2;
+ struct mid_q_entry *mid_entry = NULL;
+
+ spin_lock(&GlobalMid_Lock);
+ list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
+ mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
+
+ if (mid_entry->mid != buf->Mid ||
+ mid_entry->midState != MID_REQUEST_SUBMITTED ||
+ mid_entry->command != buf->Command) {
+ mid_entry = NULL;
+ continue;
+ }
+
+ if (*length == 0 && check2ndT2(buf, server->maxBuf) > 0) {
+ /* We have a multipart transact2 resp */
+ *isMultiRsp = true;
+ if (mid_entry->resp_buf) {
+ /* merge response - fix up 1st*/
+ *length = coalesce_t2(buf, mid_entry->resp_buf);
+ if (*length > 0) {
+ *length = 0;
+ mid_entry->multiRsp = true;
+ break;
+ } else {
+ /* all parts received or
+ * packet is malformed
+ */
+ mid_entry->multiEnd = true;
+ goto multi_t2_fnd;
+ }
+ } else {
+ if (!isLargeBuf) {
+ /*
+ * FIXME: switch to already
+ * allocated largebuf?
+ */
+ cERROR(1, "1st trans2 resp "
+ "needs bigbuf");
+ } else {
+ /* Have first buffer */
+ mid_entry->resp_buf = buf;
+ mid_entry->largeBuf = true;
+ *pbigbuf = NULL;
+ }
+ }
+ break;
+ }
+ mid_entry->resp_buf = buf;
+ mid_entry->largeBuf = isLargeBuf;
+multi_t2_fnd:
+ if (*length == 0)
+ mid_entry->midState = MID_RESPONSE_RECEIVED;
+ else
+ mid_entry->midState = MID_RESPONSE_MALFORMED;
+#ifdef CONFIG_CIFS_STATS2
+ mid_entry->when_received = jiffies;
+#endif
+ list_del_init(&mid_entry->qhead);
+ break;
+ }
+ spin_unlock(&GlobalMid_Lock);
+
+ return mid_entry;
+}
+
+static int
+check_rfc1002_header(struct TCP_Server_Info *server, char *buf, int length,
+ unsigned int pdu_length, struct socket **psocket)
+{
+ char temp = *buf;
+
+ /*
+ * The first byte big endian of the length field,
+ * is actually not part of the length but the type
+ * with the most common, zero, as regular data.
+ */
+ if (temp == (char) RFC1002_SESSION_KEEP_ALIVE) {
+ return 1;
+ } else if (temp == (char)RFC1002_POSITIVE_SESSION_RESPONSE) {
+ cFYI(1, "Good RFC 1002 session rsp");
+ return 1;
+ } else if (temp == (char)RFC1002_NEGATIVE_SESSION_RESPONSE) {
+ /* we get this from Windows 98 instead of
+ an error on SMB negprot response */
+ cFYI(1, "Negative RFC1002 Session Response Error 0x%x)",
+ pdu_length);
+ /* give server a second to clean up */
+ msleep(1000);
+ /* always try 445 first on reconnect since we get NACK
+ * on some if we ever connected to port 139 (the NACK
+ * is since we do not begin with RFC1001 session
+ * initialize frame)
+ */
+ cifs_set_port((struct sockaddr *)
+ &server->dstaddr, CIFS_PORT);
+ cifs_reconnect(server);
+ *psocket = server->ssocket;
+ wake_up(&server->response_q);
+ return 1;
+ } else if (temp != (char) 0) {
+ cERROR(1, "Unknown RFC 1002 frame");
+ cifs_dump_mem(" Received Data: ", buf, length);
+ cifs_reconnect(server);
+ *psocket = server->ssocket;
+ return 1;
+ }
+
+ /* else we have an SMB response */
+ if ((pdu_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) ||
+ (pdu_length < sizeof(struct smb_hdr) - 1 - 4)) {
+ cERROR(1, "Invalid size SMB length %d pdu_length %d",
+ length, pdu_length+4);
+ cifs_reconnect(server);
+ *psocket = server->ssocket;
+ wake_up(&server->response_q);
+ return 1;
+ }
+
+ return 0;
+}
+
+static int
+allocate_bufs(char **pbigbuf, char **psmallbuf, unsigned int size,
+ bool isLargeBuf)
+{
+ char *bigbuf = *pbigbuf, *smallbuf = *psmallbuf;
+
+ if (bigbuf == NULL) {
+ bigbuf = (char *)cifs_buf_get();
+ if (!bigbuf) {
+ cERROR(1, "No memory for large SMB response");
+ msleep(3000);
+ /* retry will check if exiting */
+ return 1;
+ }
+ } else if (isLargeBuf) {
+ /* we are reusing a dirty large buf, clear its start */
+ memset(bigbuf, 0, size);
+ }
+
+ if (smallbuf == NULL) {
+ smallbuf = (char *)cifs_small_buf_get();
+ if (!smallbuf) {
+ cERROR(1, "No memory for SMB response");
+ msleep(1000);
+ /* retry will check if exiting */
+ return 1;
+ }
+ /* beginning of smb buffer is cleared in our buf_get */
+ } else /* if existing small buf clear beginning */
+ memset(smallbuf, 0, size);
+
+ *pbigbuf = bigbuf;
+ *psmallbuf = smallbuf;
+
+ return 0;
+}
+
+static int
+read_from_socket(struct TCP_Server_Info *server, unsigned int pdu_length,
+ struct socket **psocket, struct msghdr *smb_msg,
+ struct kvec *iov, unsigned int *ptotal_read)
+{
+ int length, rc = 0;
+ unsigned int total_read;
+
+ for (total_read = 0; total_read < pdu_length;
+ total_read += length) {
+ length = kernel_recvmsg(*psocket, smb_msg, iov, 1,
+ pdu_length - total_read, 0);
+ if (server->tcpStatus == CifsExiting) {
+ /* then will exit */
+ rc = 2;
+ break;
+ } else if (server->tcpStatus == CifsNeedReconnect) {
+ cifs_reconnect(server);
+ *psocket = server->ssocket;
+ /* Reconnect wakes up rspns q */
+ /* Now we will reread sock */
+ rc = 1;
+ break;
+ } else if (length == -ERESTARTSYS ||
+ length == -EAGAIN ||
+ length == -EINTR) {
+ /*
+ * Minimum sleep to prevent looping,
+ * allowing socket to clear and app
+ * threads to set tcpStatus
+ * CifsNeedReconnect if server hung.
+ */
+ usleep_range(1000, 2000);
+ length = 0;
+ continue;
+ } else if (length <= 0) {
+ cERROR(1, "Received no data, expecting %d",
+ pdu_length - total_read);
+ cifs_reconnect(server);
+ *psocket = server->ssocket;
+ rc = 1;
+ break;
+ }
+ }
+
+ *ptotal_read = total_read;
+ return 0;
+}
+
static int
cifs_demultiplex_thread(struct TCP_Server_Info *server)
{
int length;
unsigned int pdu_length, total_read;
+ char *buf = NULL, *smallbuf = NULL, *bigbuf = NULL;
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, *tmp2;
struct task_struct *task_to_wake = NULL;
struct mid_q_entry *mid_entry;
- char temp;
bool isLargeBuf = false;
bool isMultiRsp;
- int reconnect;
+ int rc;
current->flags |= PF_MEMALLOC;
cFYI(1, "Demultiplex PID: %d", task_pid_nr(current));
@@ -348,35 +558,17 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
while (server->tcpStatus != CifsExiting) {
if (try_to_freeze())
continue;
- 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));
+ rc = allocate_bufs(&bigbuf, &smallbuf, sizeof(struct smb_hdr),
+ isLargeBuf);
+ if (rc)
+ continue;
isLargeBuf = false;
isMultiRsp = false;
- smb_buffer = smallbuf;
- iov.iov_base = smb_buffer;
+ smb_buffer = (struct smb_hdr *)smallbuf;
+ buf = smallbuf;
+ iov.iov_base = smallbuf;
iov.iov_len = 4;
smb_msg.msg_control = NULL;
smb_msg.msg_controllen = 0;
@@ -414,8 +606,7 @@ incomplete_rcv:
allowing socket to clear and app threads to set
tcpStatus CifsNeedReconnect if server hung */
if (pdu_length < 4) {
- iov.iov_base = (4 - pdu_length) +
- (char *)smb_buffer;
+ iov.iov_base = (4 - pdu_length) + buf;
iov.iov_len = pdu_length;
smb_msg.msg_control = NULL;
smb_msg.msg_controllen = 0;
@@ -440,114 +631,42 @@ incomplete_rcv:
/* The right amount was read from socket - 4 bytes */
/* so we can now interpret the length field */
- /* the first byte big endian of the length field,
- is actually not part of the length but the type
- with the most common, zero, as regular data */
- temp = *((char *) smb_buffer);
-
- /* Note that FC 1001 length is big endian on the wire,
- but we convert it here so it is always manipulated
- as host byte order */
+ /*
+ * Note that FC 1001 length is big endian on the wire,
+ * but we convert it here so it is always manipulated
+ * as host byte order
+ */
pdu_length = be32_to_cpu(smb_buffer->smb_buf_length);
-
- cFYI(1, "rfc1002 length 0x%x", pdu_length+4);
-
- if (temp == (char) RFC1002_SESSION_KEEP_ALIVE) {
- continue;
- } else if (temp == (char)RFC1002_POSITIVE_SESSION_RESPONSE) {
- cFYI(1, "Good RFC 1002 session rsp");
- continue;
- } else if (temp == (char)RFC1002_NEGATIVE_SESSION_RESPONSE) {
- /* we get this from Windows 98 instead of
- an error on SMB negprot response */
- cFYI(1, "Negative RFC1002 Session Response Error 0x%x)",
- pdu_length);
- /* give server a second to clean up */
- msleep(1000);
- /* always try 445 first on reconnect since we get NACK
- * on some if we ever connected to port 139 (the NACK
- * is since we do not begin with RFC1001 session
- * initialize frame)
- */
- cifs_set_port((struct sockaddr *)
- &server->dstaddr, CIFS_PORT);
- cifs_reconnect(server);
- csocket = server->ssocket;
- wake_up(&server->response_q);
- continue;
- } else if (temp != (char) 0) {
- cERROR(1, "Unknown RFC 1002 frame");
- cifs_dump_mem(" Received Data: ", (char *)smb_buffer,
- length);
- cifs_reconnect(server);
- csocket = server->ssocket;
- continue;
- }
-
- /* else we have an SMB response */
- if ((pdu_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) ||
- (pdu_length < sizeof(struct smb_hdr) - 1 - 4)) {
- cERROR(1, "Invalid size SMB length %d pdu_length %d",
- length, pdu_length+4);
- cifs_reconnect(server);
- csocket = server->ssocket;
- wake_up(&server->response_q);
+ rc = check_rfc1002_header(server, buf, length, pdu_length,
+ &csocket);
+ if (rc)
continue;
- }
- /* else length ok */
- reconnect = 0;
+ cFYI(1, "rfc1002 length 0x%x", pdu_length+4);
if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
isLargeBuf = true;
memcpy(bigbuf, smallbuf, 4);
- smb_buffer = bigbuf;
+ smb_buffer = (struct smb_hdr *)bigbuf;
+ buf = bigbuf;
}
- length = 0;
- iov.iov_base = 4 + (char *)smb_buffer;
+
+ iov.iov_base = 4 + buf;
iov.iov_len = pdu_length;
- for (total_read = 0; total_read < pdu_length;
- total_read += length) {
- length = kernel_recvmsg(csocket, &smb_msg, &iov, 1,
- pdu_length - total_read, 0);
- if (server->tcpStatus == CifsExiting) {
- /* then will exit */
- reconnect = 2;
- break;
- } else if (server->tcpStatus == CifsNeedReconnect) {
- cifs_reconnect(server);
- csocket = server->ssocket;
- /* Reconnect wakes up rspns q */
- /* Now we will reread sock */
- reconnect = 1;
- break;
- } else if (length == -ERESTARTSYS ||
- length == -EAGAIN ||
- length == -EINTR) {
- msleep(1); /* minimum sleep to prevent looping,
- allowing socket to clear and app
- threads to set tcpStatus
- CifsNeedReconnect if server hung*/
- length = 0;
- continue;
- } else if (length <= 0) {
- cERROR(1, "Received no data, expecting %d",
- pdu_length - total_read);
- cifs_reconnect(server);
- csocket = server->ssocket;
- reconnect = 1;
- break;
- }
- }
- if (reconnect == 2)
+ rc = read_from_socket(server, pdu_length, &csocket, &smb_msg,
+ &iov, &total_read);
+ if (rc == 2)
break;
- else if (reconnect == 1)
+ else if (rc == 1)
continue;
total_read += 4; /* account for rfc1002 hdr */
dump_smb(smb_buffer, total_read);
+ server->lstrp = jiffies;
+ length = 0;
+
/*
* We know that we received enough to get to the MID as we
* checked the pdu_length earlier. Now check to see
@@ -559,75 +678,11 @@ incomplete_rcv:
*/
length = checkSMB(smb_buffer, smb_buffer->Mid, total_read);
if (length != 0)
- cifs_dump_mem("Bad SMB: ", smb_buffer,
- min_t(unsigned int, total_read, 48));
-
- mid_entry = NULL;
- server->lstrp = jiffies;
-
- spin_lock(&GlobalMid_Lock);
- list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
- mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
-
- if (mid_entry->mid != smb_buffer->Mid ||
- mid_entry->midState != MID_REQUEST_SUBMITTED ||
- mid_entry->command != smb_buffer->Command) {
- mid_entry = NULL;
- continue;
- }
-
- if (length == 0 &&
- check2ndT2(smb_buffer, server->maxBuf) > 0) {
- /* We have a multipart transact2 resp */
- isMultiRsp = true;
- if (mid_entry->resp_buf) {
- /* merge response - fix up 1st*/
- length = coalesce_t2(smb_buffer,
- mid_entry->resp_buf);
- if (length > 0) {
- length = 0;
- mid_entry->multiRsp = true;
- break;
- } else {
- /* all parts received or
- * packet is malformed
- */
- mid_entry->multiEnd = true;
- goto multi_t2_fnd;
- }
- } else {
- if (!isLargeBuf) {
- /*
- * FIXME: switch to already
- * allocated largebuf?
- */
- cERROR(1, "1st trans2 resp "
- "needs bigbuf");
- } else {
- /* Have first buffer */
- mid_entry->resp_buf =
- smb_buffer;
- mid_entry->largeBuf = true;
- bigbuf = NULL;
- }
- }
- break;
- }
- mid_entry->resp_buf = smb_buffer;
- mid_entry->largeBuf = isLargeBuf;
-multi_t2_fnd:
- if (length == 0)
- mid_entry->midState = MID_RESPONSE_RECEIVED;
- else
- mid_entry->midState = MID_RESPONSE_MALFORMED;
-#ifdef CONFIG_CIFS_STATS2
- mid_entry->when_received = jiffies;
-#endif
- list_del_init(&mid_entry->qhead);
- break;
- }
- spin_unlock(&GlobalMid_Lock);
+ cifs_dump_mem("Bad SMB: ", buf,
+ min_t(unsigned int, total_read, 48));
+ mid_entry = find_cifs_owner(server, smb_buffer, &length,
+ isLargeBuf, &isMultiRsp, &bigbuf);
if (mid_entry != NULL) {
mid_entry->callback(mid_entry);
/* Was previous buf put in mpx struct for multi-rsp? */
@@ -645,13 +700,12 @@ multi_t2_fnd:
!isMultiRsp) {
cERROR(1, "No task to wake, unknown frame received! "
"NumMids %d", atomic_read(&midCount));
- cifs_dump_mem("Received Data is: ", (char *)smb_buffer,
+ cifs_dump_mem("Received Data is: ", buf,
sizeof(struct smb_hdr));
#ifdef CONFIG_CIFS_DEBUG2
cifs_dump_detail(smb_buffer);
cifs_dump_mids(server);
#endif /* CIFS_DEBUG2 */
-
}
} /* end while !EXITING */
--
1.7.1
--
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