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-rw-r--r--fs/cifs/transport.c283
1 files changed, 197 insertions, 86 deletions
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index d9b639b95fa8..2126ab185045 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -27,6 +27,8 @@
#include <linux/net.h>
#include <linux/delay.h>
#include <linux/freezer.h>
+#include <linux/tcp.h>
+#include <linux/highmem.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <linux/mempool.h>
@@ -109,8 +111,8 @@ DeleteMidQEntry(struct mid_q_entry *midEntry)
mempool_free(midEntry, cifs_mid_poolp);
}
-static void
-delete_mid(struct mid_q_entry *mid)
+void
+cifs_delete_mid(struct mid_q_entry *mid)
{
spin_lock(&GlobalMid_Lock);
list_del(&mid->qhead);
@@ -119,18 +121,29 @@ delete_mid(struct mid_q_entry *mid)
DeleteMidQEntry(mid);
}
+/*
+ * smb_send_kvec - send an array of kvecs to the server
+ * @server: Server to send the data to
+ * @iov: Pointer to array of kvecs
+ * @n_vec: length of kvec array
+ * @sent: amount of data sent on socket is stored here
+ *
+ * Our basic "send data to server" function. Should be called with srv_mutex
+ * held. The caller is responsible for handling the results.
+ */
static int
-smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
+smb_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec,
+ size_t *sent)
{
int rc = 0;
int i = 0;
struct msghdr smb_msg;
- unsigned int len = iov[0].iov_len;
- unsigned int total_len;
- int first_vec = 0;
- unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
+ unsigned int remaining;
+ size_t first_vec = 0;
struct socket *ssocket = server->ssocket;
+ *sent = 0;
+
if (ssocket == NULL)
return -ENOTSOCK; /* BB eventually add reconnect code here */
@@ -143,56 +156,60 @@ smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
else
smb_msg.msg_flags = MSG_NOSIGNAL;
- total_len = 0;
+ remaining = 0;
for (i = 0; i < n_vec; i++)
- total_len += iov[i].iov_len;
-
- cFYI(1, "Sending smb: total_len %d", total_len);
- dump_smb(iov[0].iov_base, len);
+ remaining += iov[i].iov_len;
i = 0;
- while (total_len) {
+ while (remaining) {
+ /*
+ * If blocking send, we try 3 times, since each can block
+ * for 5 seconds. For nonblocking we have to try more
+ * but wait increasing amounts of time allowing time for
+ * socket to clear. The overall time we wait in either
+ * case to send on the socket is about 15 seconds.
+ * Similarly we wait for 15 seconds for a response from
+ * the server in SendReceive[2] for the server to send
+ * a response back for most types of requests (except
+ * SMB Write past end of file which can be slow, and
+ * blocking lock operations). NFS waits slightly longer
+ * than CIFS, but this can make it take longer for
+ * nonresponsive servers to be detected and 15 seconds
+ * is more than enough time for modern networks to
+ * send a packet. In most cases if we fail to send
+ * after the retries we will kill the socket and
+ * reconnect which may clear the network problem.
+ */
rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
- n_vec - first_vec, total_len);
- if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
+ n_vec - first_vec, remaining);
+ if (rc == -ENOSPC || rc == -EAGAIN) {
i++;
- /*
- * If blocking send we try 3 times, since each can block
- * for 5 seconds. For nonblocking we have to try more
- * but wait increasing amounts of time allowing time for
- * socket to clear. The overall time we wait in either
- * case to send on the socket is about 15 seconds.
- * Similarly we wait for 15 seconds for a response from
- * the server in SendReceive[2] for the server to send
- * a response back for most types of requests (except
- * SMB Write past end of file which can be slow, and
- * blocking lock operations). NFS waits slightly longer
- * than CIFS, but this can make it take longer for
- * nonresponsive servers to be detected and 15 seconds
- * is more than enough time for modern networks to
- * send a packet. In most cases if we fail to send
- * after the retries we will kill the socket and
- * reconnect which may clear the network problem.
- */
- if ((i >= 14) || (!server->noblocksnd && (i > 2))) {
- cERROR(1, "sends on sock %p stuck for 15 seconds",
- ssocket);
+ if (i >= 14 || (!server->noblocksnd && (i > 2))) {
+ cERROR(1, "sends on sock %p stuck for 15 "
+ "seconds", ssocket);
rc = -EAGAIN;
break;
}
msleep(1 << i);
continue;
}
+
if (rc < 0)
break;
- if (rc == total_len) {
- total_len = 0;
+ /* send was at least partially successful */
+ *sent += rc;
+
+ if (rc == remaining) {
+ remaining = 0;
break;
- } else if (rc > total_len) {
- cERROR(1, "sent %d requested %d", rc, total_len);
+ }
+
+ if (rc > remaining) {
+ cERROR(1, "sent %d requested %d", rc, remaining);
break;
}
+
if (rc == 0) {
/* should never happen, letting socket clear before
retrying is our only obvious option here */
@@ -200,7 +217,9 @@ smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
msleep(500);
continue;
}
- total_len -= rc;
+
+ remaining -= rc;
+
/* the line below resets i */
for (i = first_vec; i < n_vec; i++) {
if (iov[i].iov_len) {
@@ -215,16 +234,97 @@ smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
}
}
}
+
i = 0; /* in case we get ENOSPC on the next send */
+ rc = 0;
}
+ return rc;
+}
+
+/**
+ * rqst_page_to_kvec - Turn a slot in the smb_rqst page array into a kvec
+ * @rqst: pointer to smb_rqst
+ * @idx: index into the array of the page
+ * @iov: pointer to struct kvec that will hold the result
+ *
+ * Helper function to convert a slot in the rqst->rq_pages array into a kvec.
+ * The page will be kmapped and the address placed into iov_base. The length
+ * will then be adjusted according to the ptailoff.
+ */
+void
+cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx,
+ struct kvec *iov)
+{
+ /*
+ * FIXME: We could avoid this kmap altogether if we used
+ * kernel_sendpage instead of kernel_sendmsg. That will only
+ * work if signing is disabled though as sendpage inlines the
+ * page directly into the fraglist. If userspace modifies the
+ * page after we calculate the signature, then the server will
+ * reject it and may break the connection. kernel_sendmsg does
+ * an extra copy of the data and avoids that issue.
+ */
+ iov->iov_base = kmap(rqst->rq_pages[idx]);
+
+ /* if last page, don't send beyond this offset into page */
+ if (idx == (rqst->rq_npages - 1))
+ iov->iov_len = rqst->rq_tailsz;
+ else
+ iov->iov_len = rqst->rq_pagesz;
+}
+
+static int
+smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
+{
+ int rc;
+ struct kvec *iov = rqst->rq_iov;
+ int n_vec = rqst->rq_nvec;
+ unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
+ unsigned int i;
+ size_t total_len = 0, sent;
+ struct socket *ssocket = server->ssocket;
+ int val = 1;
+
+ cFYI(1, "Sending smb: smb_len=%u", smb_buf_length);
+ dump_smb(iov[0].iov_base, iov[0].iov_len);
+
+ /* cork the socket */
+ kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
+ (char *)&val, sizeof(val));
+
+ rc = smb_send_kvec(server, iov, n_vec, &sent);
+ if (rc < 0)
+ goto uncork;
+
+ total_len += sent;
+
+ /* now walk the page array and send each page in it */
+ for (i = 0; i < rqst->rq_npages; i++) {
+ struct kvec p_iov;
+
+ cifs_rqst_page_to_kvec(rqst, i, &p_iov);
+ rc = smb_send_kvec(server, &p_iov, 1, &sent);
+ kunmap(rqst->rq_pages[i]);
+ if (rc < 0)
+ break;
+
+ total_len += sent;
+ }
+
+uncork:
+ /* uncork it */
+ val = 0;
+ kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
+ (char *)&val, sizeof(val));
if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
- cFYI(1, "partial send (%d remaining), terminating session",
- total_len);
- /* If we have only sent part of an SMB then the next SMB
- could be taken as the remainder of this one. We need
- to kill the socket so the server throws away the partial
- SMB */
+ cFYI(1, "partial send (wanted=%u sent=%zu): terminating "
+ "session", smb_buf_length + 4, total_len);
+ /*
+ * If we have only sent part of an SMB then the next SMB could
+ * be taken as the remainder of this one. We need to kill the
+ * socket so the server throws away the partial SMB
+ */
server->tcpStatus = CifsNeedReconnect;
}
@@ -236,6 +336,15 @@ smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
return rc;
}
+static int
+smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
+{
+ struct smb_rqst rqst = { .rq_iov = iov,
+ .rq_nvec = n_vec };
+
+ return smb_send_rqst(server, &rqst);
+}
+
int
smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
unsigned int smb_buf_length)
@@ -345,12 +454,11 @@ wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
return 0;
}
-int
-cifs_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov,
- unsigned int nvec, struct mid_q_entry **ret_mid)
+struct mid_q_entry *
+cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
{
int rc;
- struct smb_hdr *hdr = (struct smb_hdr *)iov[0].iov_base;
+ struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
struct mid_q_entry *mid;
/* enable signing if server requires it */
@@ -359,16 +467,15 @@ cifs_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov,
mid = AllocMidQEntry(hdr, server);
if (mid == NULL)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
- rc = cifs_sign_smbv(iov, nvec, server, &mid->sequence_number);
+ rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
if (rc) {
DeleteMidQEntry(mid);
- return rc;
+ return ERR_PTR(rc);
}
- *ret_mid = mid;
- return 0;
+ return mid;
}
/*
@@ -376,9 +483,9 @@ cifs_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov,
* the result. Caller is responsible for dealing with timeouts.
*/
int
-cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
- unsigned int nvec, mid_receive_t *receive,
- mid_callback_t *callback, void *cbdata, const int flags)
+cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
+ mid_receive_t *receive, mid_callback_t *callback,
+ void *cbdata, const int flags)
{
int rc, timeout, optype;
struct mid_q_entry *mid;
@@ -391,12 +498,12 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
return rc;
mutex_lock(&server->srv_mutex);
- rc = server->ops->setup_async_request(server, iov, nvec, &mid);
- if (rc) {
+ mid = server->ops->setup_async_request(server, rqst);
+ if (IS_ERR(mid)) {
mutex_unlock(&server->srv_mutex);
add_credits(server, 1, optype);
wake_up(&server->request_q);
- return rc;
+ return PTR_ERR(mid);
}
mid->receive = receive;
@@ -411,7 +518,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
cifs_in_send_inc(server);
- rc = smb_sendv(server, iov, nvec);
+ rc = smb_send_rqst(server, rqst);
cifs_in_send_dec(server);
cifs_save_when_sent(mid);
mutex_unlock(&server->srv_mutex);
@@ -419,7 +526,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
if (rc == 0)
return 0;
- delete_mid(mid);
+ cifs_delete_mid(mid);
add_credits(server, 1, optype);
wake_up(&server->request_q);
return rc;
@@ -504,11 +611,13 @@ cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
struct kvec iov;
int rc = 0;
+ struct smb_rqst rqst = { .rq_iov = &iov,
+ .rq_nvec = 1 };
iov.iov_base = mid->resp_buf;
iov.iov_len = len;
/* FIXME: add code to kill session */
- rc = cifs_verify_signature(&iov, 1, server,
+ rc = cifs_verify_signature(&rqst, server,
mid->sequence_number + 1);
if (rc)
cERROR(1, "SMB signature verification returned error = "
@@ -519,22 +628,22 @@ cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
return map_smb_to_linux_error(mid->resp_buf, log_error);
}
-int
-cifs_setup_request(struct cifs_ses *ses, struct kvec *iov,
- unsigned int nvec, struct mid_q_entry **ret_mid)
+struct mid_q_entry *
+cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
{
int rc;
- struct smb_hdr *hdr = (struct smb_hdr *)iov[0].iov_base;
+ struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
struct mid_q_entry *mid;
rc = allocate_mid(ses, hdr, &mid);
if (rc)
- return rc;
- rc = cifs_sign_smbv(iov, nvec, ses->server, &mid->sequence_number);
- if (rc)
- delete_mid(mid);
- *ret_mid = mid;
- return rc;
+ return ERR_PTR(rc);
+ rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
+ if (rc) {
+ cifs_delete_mid(mid);
+ return ERR_PTR(rc);
+ }
+ return mid;
}
int
@@ -547,6 +656,8 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
struct mid_q_entry *midQ;
char *buf = iov[0].iov_base;
unsigned int credits = 1;
+ struct smb_rqst rqst = { .rq_iov = iov,
+ .rq_nvec = n_vec };
timeout = flags & CIFS_TIMEOUT_MASK;
optype = flags & CIFS_OP_MASK;
@@ -584,13 +695,13 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
mutex_lock(&ses->server->srv_mutex);
- rc = ses->server->ops->setup_request(ses, iov, n_vec, &midQ);
- if (rc) {
+ midQ = ses->server->ops->setup_request(ses, &rqst);
+ if (IS_ERR(midQ)) {
mutex_unlock(&ses->server->srv_mutex);
cifs_small_buf_release(buf);
/* Update # of requests on wire to server */
add_credits(ses->server, 1, optype);
- return rc;
+ return PTR_ERR(midQ);
}
midQ->mid_state = MID_REQUEST_SUBMITTED;
@@ -652,11 +763,11 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
rc = ses->server->ops->check_receive(midQ, ses->server,
flags & CIFS_LOG_ERROR);
- /* mark it so buf will not be freed by delete_mid */
+ /* mark it so buf will not be freed by cifs_delete_mid */
if ((flags & CIFS_NO_RESP) == 0)
midQ->resp_buf = NULL;
out:
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
add_credits(ses->server, credits, optype);
return rc;
@@ -762,7 +873,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
rc = cifs_check_receive(midQ, ses->server, 0);
out:
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
add_credits(ses->server, 1, 0);
return rc;
@@ -846,7 +957,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
if (rc) {
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
mutex_unlock(&ses->server->srv_mutex);
return rc;
}
@@ -859,7 +970,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
mutex_unlock(&ses->server->srv_mutex);
if (rc < 0) {
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
return rc;
}
@@ -880,7 +991,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
blocking lock to return. */
rc = send_cancel(ses->server, in_buf, midQ);
if (rc) {
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
return rc;
}
} else {
@@ -892,7 +1003,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
/* If we get -ENOLCK back the lock may have
already been removed. Don't exit in this case. */
if (rc && rc != -ENOLCK) {
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
return rc;
}
}
@@ -929,7 +1040,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
rc = cifs_check_receive(midQ, ses->server, 0);
out:
- delete_mid(midQ);
+ cifs_delete_mid(midQ);
if (rstart && rc == -EACCES)
return -ERESTARTSYS;
return rc;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.