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author | Hyunchul Lee <hyc.lee@gmail.com> | 2021-10-07 16:26:58 +0900 |
---|---|---|
committer | Steve French <stfrench@microsoft.com> | 2021-10-13 23:37:19 -0500 |
commit | bf8acc9e10e21c28452dfa067a7d31e6067104b1 (patch) | |
tree | e1b7e8d3fdd4a7382f85277c7ae354bce1f5689a /fs/ksmbd/smb2misc.c | |
parent | f7db8fd03a4bc5baf70ccf8978fe17cb54368b97 (diff) | |
download | lwn-bf8acc9e10e21c28452dfa067a7d31e6067104b1.tar.gz lwn-bf8acc9e10e21c28452dfa067a7d31e6067104b1.zip |
ksmbd: improve credits management
* 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.
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/ksmbd/smb2misc.c')
-rw-r--r-- | fs/ksmbd/smb2misc.c | 38 |
1 files changed, 28 insertions, 10 deletions
diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c index 9edd9c161b27..e7e441c8f050 100644 --- a/fs/ksmbd/smb2misc.c +++ b/fs/ksmbd/smb2misc.c @@ -284,11 +284,13 @@ 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: @@ -310,21 +312,37 @@ 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) @@ -383,7 +401,7 @@ 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; } |