* Requests except READ, WRITE, IOCTL, INFO, QUERY
DIRECOTRY, CANCEL must consume one credit.
* If client's granted credits are insufficient,
refuse to handle requests.
* Windows server 2016 or later grant up to 8192
credits to clients at once.
* For an asynchronous operation, grant credits
for an interim response and 0 credit for the
final response.
Signed-off-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
---
fs/ksmbd/smb2misc.c | 38 ++++++++++++++------
fs/ksmbd/smb2ops.c | 4 +++
fs/ksmbd/smb2pdu.c | 86 ++++++++++++++++++++-------------------------
3 files changed, 71 insertions(+), 57 deletions(-)
diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c
index 9aa46bb3e10d..cbbea6937816 100644
--- a/fs/ksmbd/smb2misc.c
+++ b/fs/ksmbd/smb2misc.c
@@ -287,11 +287,13 @@ static inline int smb2_ioctl_resp_len(struct smb2_ioctl_req *h)
le32_to_cpu(h->MaxOutputResponse);
}
-static int smb2_validate_credit_charge(struct smb2_hdr *hdr)
+static int smb2_validate_credit_charge(struct ksmbd_conn *conn,
+ struct smb2_hdr *hdr)
{
- int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len;
- int credit_charge = le16_to_cpu(hdr->CreditCharge);
+ unsigned int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len;
+ unsigned short credit_charge = le16_to_cpu(hdr->CreditCharge);
void *__hdr = hdr;
+ int ret;
switch (hdr->Command) {
case SMB2_QUERY_INFO:
@@ -313,21 +315,37 @@ static int smb2_validate_credit_charge(struct smb2_hdr *hdr)
req_len = smb2_ioctl_req_len(__hdr);
expect_resp_len = smb2_ioctl_resp_len(__hdr);
break;
- default:
+ case SMB2_CANCEL:
return 0;
+ default:
+ req_len = 1;
+ break;
}
- credit_charge = max(1, credit_charge);
- max_len = max(req_len, expect_resp_len);
+ credit_charge = max_t(unsigned short, credit_charge, 1);
+ max_len = max_t(unsigned int, req_len, expect_resp_len);
calc_credit_num = DIV_ROUND_UP(max_len, SMB2_MAX_BUFFER_SIZE);
if (credit_charge < calc_credit_num) {
- pr_err("Insufficient credit charge, given: %d, needed: %d\n",
- credit_charge, calc_credit_num);
+ ksmbd_debug(SMB, "Insufficient credit charge, given: %d, needed: %d\n",
+ credit_charge, calc_credit_num);
+ return 1;
+ } else if (credit_charge > conn->max_credits) {
+ ksmbd_debug(SMB, "Too large credit charge: %d\n", credit_charge);
return 1;
}
- return 0;
+ spin_lock(&conn->credits_lock);
+ if (credit_charge <= conn->total_credits) {
+ conn->total_credits -= credit_charge;
+ ret = 0;
+ } else {
+ ksmbd_debug(SMB, "Insufficient credits granted, given: %u, granted: %u\n",
+ credit_charge, conn->total_credits);
+ ret = 1;
+ }
+ spin_unlock(&conn->credits_lock);
+ return ret;
}
int ksmbd_smb2_check_message(struct ksmbd_work *work)
@@ -386,7 +404,7 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work)
}
if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) &&
- smb2_validate_credit_charge(hdr)) {
+ smb2_validate_credit_charge(work->conn, hdr)) {
work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
return 1;
}
diff --git a/fs/ksmbd/smb2ops.c b/fs/ksmbd/smb2ops.c
index 197473871aa4..d7919f95be40 100644
--- a/fs/ksmbd/smb2ops.c
+++ b/fs/ksmbd/smb2ops.c
@@ -203,6 +203,7 @@ void init_smb2_1_server(struct ksmbd_conn *conn)
conn->ops = &smb2_0_server_ops;
conn->cmds = smb2_0_server_cmds;
conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds);
+ conn->total_credits = 1;
conn->max_credits = SMB2_MAX_CREDITS;
conn->signing_algorithm = SIGNING_ALG_HMAC_SHA256;
@@ -221,6 +222,7 @@ void init_smb3_0_server(struct ksmbd_conn *conn)
conn->ops = &smb3_0_server_ops;
conn->cmds = smb2_0_server_cmds;
conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds);
+ conn->total_credits = 1;
conn->max_credits = SMB2_MAX_CREDITS;
conn->signing_algorithm = SIGNING_ALG_AES_CMAC;
@@ -246,6 +248,7 @@ void init_smb3_02_server(struct ksmbd_conn *conn)
conn->ops = &smb3_0_server_ops;
conn->cmds = smb2_0_server_cmds;
conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds);
+ conn->total_credits = 1;
conn->max_credits = SMB2_MAX_CREDITS;
conn->signing_algorithm = SIGNING_ALG_AES_CMAC;
@@ -271,6 +274,7 @@ int init_smb3_11_server(struct ksmbd_conn *conn)
conn->ops = &smb3_11_server_ops;
conn->cmds = smb2_0_server_cmds;
conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds);
+ conn->total_credits = 1;
conn->max_credits = SMB2_MAX_CREDITS;
conn->signing_algorithm = SIGNING_ALG_AES_CMAC;
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index dcf907738610..6df0b0759d3f 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -295,22 +295,6 @@ int init_smb2_neg_rsp(struct ksmbd_work *work)
return 0;
}
-static int smb2_consume_credit_charge(struct ksmbd_work *work,
- unsigned short credit_charge)
-{
- struct ksmbd_conn *conn = work->conn;
- unsigned int rsp_credits = 1;
-
- if (!conn->total_credits)
- return 0;
-
- if (credit_charge > 0)
- rsp_credits = credit_charge;
-
- conn->total_credits -= rsp_credits;
- return rsp_credits;
-}
-
/**
* smb2_set_rsp_credits() - set number of credits in response buffer
* @work: smb work containing smb response buffer
@@ -320,48 +304,51 @@ int smb2_set_rsp_credits(struct ksmbd_work *work)
struct smb2_hdr *req_hdr = ksmbd_req_buf_next(work);
struct smb2_hdr *hdr = ksmbd_resp_buf_next(work);
struct ksmbd_conn *conn = work->conn;
- unsigned short credits_requested = le16_to_cpu(req_hdr->CreditRequest);
- unsigned short credit_charge = 1, credits_granted = 0;
- unsigned short aux_max, aux_credits, min_credits;
- int rsp_credit_charge;
+ unsigned short credits_requested;
+ unsigned short credit_charge, credits_granted = 0;
+ unsigned short aux_max, aux_credits;
- if (hdr->Command == SMB2_CANCEL)
- goto out;
+ if (work->send_no_response)
+ return 0;
- /* get default minimum credits by shifting maximum credits by 4 */
- min_credits = conn->max_credits >> 4;
+ hdr->CreditCharge = req_hdr->CreditCharge;
- if (conn->total_credits >= conn->max_credits) {
+ if (conn->total_credits > conn->max_credits) {
+ hdr->CreditRequest = 0;
pr_err("Total credits overflow: %d\n", conn->total_credits);
- conn->total_credits = min_credits;
- }
-
- rsp_credit_charge =
- smb2_consume_credit_charge(work, le16_to_cpu(req_hdr->CreditCharge));
- if (rsp_credit_charge < 0)
return -EINVAL;
+ }
- hdr->CreditCharge = cpu_to_le16(rsp_credit_charge);
+ credit_charge = max_t(unsigned short,
+ le16_to_cpu(req_hdr->CreditCharge), 1);
+ credits_requested = max_t(unsigned short,
+ le16_to_cpu(req_hdr->CreditRequest), 1);
- if (credits_requested > 0) {
+ /* We must grant 0 credit for the final response of an asynchronous
+ * operation.
+ */
+ if ((hdr->Flags & SMB2_FLAGS_ASYNC_COMMAND) && !work->multiRsp) {
+ credits_granted = 0;
+ } else {
+ /* according to smb2.credits smbtorture, Windows server
+ * 2016 or later grant up to 8192 credits at one.
+ */
aux_credits = credits_requested - 1;
- aux_max = 32;
if (hdr->Command == SMB2_NEGOTIATE)
aux_max = 0;
- aux_credits = (aux_credits < aux_max) ? aux_credits : aux_max;
- credits_granted = aux_credits + credit_charge;
+ else
+ aux_max = conn->max_credits - credit_charge;
+ aux_credits = min_t(unsigned short, aux_credits, aux_max);
+ credits_granted = credit_charge + aux_credits;
+
+ if (conn->max_credits - conn->total_credits < credits_granted)
+ credits_granted = conn->max_credits -
+ conn->total_credits;
- /* if credits granted per client is getting bigger than default
- * minimum credits then we should wrap it up within the limits.
- */
- if ((conn->total_credits + credits_granted) > min_credits)
- credits_granted = min_credits - conn->total_credits;
/*
* TODO: Need to adjuct CreditRequest value according to
* current cpu load
*/
- } else if (conn->total_credits == 0) {
- credits_granted = 1;
}
conn->total_credits += credits_granted;
@@ -371,7 +358,6 @@ int smb2_set_rsp_credits(struct ksmbd_work *work)
/* Update CreditRequest in last request */
hdr->CreditRequest = cpu_to_le16(work->credits_granted);
}
-out:
ksmbd_debug(SMB,
"credits: requested[%d] granted[%d] total_granted[%d]\n",
credits_requested, credits_granted,
@@ -692,13 +678,18 @@ int setup_async_work(struct ksmbd_work *work, void (*fn)(void **), void **arg)
void smb2_send_interim_resp(struct ksmbd_work *work, __le32 status)
{
- struct smb2_hdr *rsp_hdr;
+ struct smb2_hdr *rsp_hdr = work->response_buf;
+
+ work->multiRsp = 1;
+ if (status != STATUS_CANCELLED) {
+ spin_lock(&work->conn->credits_lock);
+ smb2_set_rsp_credits(work);
+ spin_unlock(&work->conn->credits_lock);
+ }
- rsp_hdr = work->response_buf;
smb2_set_err_rsp(work);
rsp_hdr->Status = status;
- work->multiRsp = 1;
ksmbd_conn_write(work);
rsp_hdr->Status = 0;
work->multiRsp = 0;
@@ -1233,6 +1224,7 @@ int smb2_handle_negotiate(struct ksmbd_work *work)
conn->srv_sec_mode = le16_to_cpu(rsp->SecurityMode);
ksmbd_conn_set_need_negotiate(work);
+ conn->total_credits = 0;
err_out:
if (rc < 0)
--
2.25.1
