diff options
Diffstat (limited to 'fs/cifs/smb2ops.c')
-rw-r--r-- | fs/cifs/smb2ops.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index ef8b2a8..54b4935 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -20,6 +20,8 @@ #include <linux/pagemap.h> #include <linux/vfs.h> #include <linux/falloc.h> +#include <linux/scatterlist.h> +#include <crypto/aead.h> #include "cifsglob.h" #include "smb2pdu.h" #include "smb2proto.h" @@ -1547,6 +1549,256 @@ smb2_dir_needs_close(struct cifsFileInfo *cfile) return !cfile->invalidHandle; } +static void +fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, struct smb_rqst *old_rq) +{ + struct smb2_sync_hdr *shdr = + (struct smb2_sync_hdr *)old_rq->rq_iov[1].iov_base; + unsigned int orig_len = get_rfc1002_length(old_rq->rq_iov[0].iov_base); + + memset(tr_hdr, 0, sizeof(struct smb2_transform_hdr)); + tr_hdr->ProtocolId = SMB2_TRANSFORM_PROTO_NUM; + tr_hdr->OriginalMessageSize = cpu_to_le32(orig_len); + tr_hdr->Flags = cpu_to_le16(0x01); + get_random_bytes(&tr_hdr->Nonce, SMB3_AES128CMM_NONCE); + memcpy(&tr_hdr->SessionId, &shdr->SessionId, 8); + inc_rfc1001_len(tr_hdr, sizeof(struct smb2_transform_hdr) - 4); + inc_rfc1001_len(tr_hdr, orig_len); +} + +static struct scatterlist * +init_sg(struct smb_rqst *rqst, u8 *sign) +{ + unsigned int sg_len = rqst->rq_nvec + rqst->rq_npages + 1; + unsigned int assoc_data_len = sizeof(struct smb2_transform_hdr) - 24; + struct scatterlist *sg; + unsigned int i; + unsigned int j; + + sg = kmalloc_array(sg_len, sizeof(struct scatterlist), GFP_KERNEL); + if (!sg) + return NULL; + + sg_init_table(sg, sg_len); + sg_set_buf(&sg[0], rqst->rq_iov[0].iov_base + 24, assoc_data_len); + for (i = 1; i < rqst->rq_nvec; i++) + sg_set_buf(&sg[i], rqst->rq_iov[i].iov_base, + rqst->rq_iov[i].iov_len); + for (j = 0; i < sg_len - 1; i++, j++) { + unsigned int len = (j < rqst->rq_npages - 1) ? rqst->rq_pagesz + : rqst->rq_tailsz; + sg_set_page(&sg[i], rqst->rq_pages[j], len, 0); + } + sg_set_buf(&sg[sg_len - 1], sign, SMB2_SIGNATURE_SIZE); + return sg; +} + +struct cifs_crypt_result { + int err; + struct completion completion; +}; + +static void cifs_crypt_complete(struct crypto_async_request *req, int err) +{ + struct cifs_crypt_result *res = req->data; + + if (err == -EINPROGRESS) + return; + + res->err = err; + complete(&res->completion); +} + +/* + * Encrypt or decrypt @rqst message. @rqst has the following format: + * iov[0] - transform header (associate data), + * iov[1-N] and pages - data to encrypt. + * On success return encrypted data in iov[1-N] and pages, leave iov[0] + * untouched. + */ +static int +crypt_message(struct TCP_Server_Info *server, struct smb_rqst *rqst, int enc) +{ + struct smb2_transform_hdr *tr_hdr = + (struct smb2_transform_hdr *)rqst->rq_iov[0].iov_base; + unsigned int assoc_data_len = sizeof(struct smb2_transform_hdr) - 24; + struct cifs_ses *ses; + int rc = 0; + struct scatterlist *sg; + u8 sign[SMB2_SIGNATURE_SIZE] = {}; + struct aead_request *req; + char *iv; + unsigned int iv_len; + struct cifs_crypt_result result = {0, }; + struct crypto_aead *tfm; + unsigned int crypt_len = le32_to_cpu(tr_hdr->OriginalMessageSize); + + init_completion(&result.completion); + + ses = smb2_find_smb_ses(server, tr_hdr->SessionId); + if (!ses) { + cifs_dbg(VFS, "%s: Could not find session\n", __func__); + return 0; + } + + rc = smb3_crypto_aead_allocate(server); + if (rc) { + cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__); + return rc; + } + + tfm = enc ? server->secmech.ccmaesencrypt : + server->secmech.ccmaesdecrypt; + rc = crypto_aead_setkey(tfm, enc ? ses->smb3encryptionkey : + ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE); + if (rc) { + cifs_dbg(VFS, "%s: Failed to set aead key %d\n", __func__, rc); + return rc; + } + + rc = crypto_aead_setauthsize(tfm, SMB2_SIGNATURE_SIZE); + if (rc) { + cifs_dbg(VFS, "%s: Failed to set authsize %d\n", __func__, rc); + return rc; + } + + req = aead_request_alloc(tfm, GFP_KERNEL); + if (!req) { + cifs_dbg(VFS, "%s: Failed to alloc aead request", __func__); + return -ENOMEM; + } + + if (!enc) { + memcpy(sign, &tr_hdr->Signature, SMB2_SIGNATURE_SIZE); + crypt_len += SMB2_SIGNATURE_SIZE; + } + + sg = init_sg(rqst, sign); + if (!sg) { + cifs_dbg(VFS, "%s: Failed to init sg %d", __func__, rc); + goto free_req; + } + + iv_len = crypto_aead_ivsize(tfm); + iv = kzalloc(iv_len, GFP_KERNEL); + if (!iv) { + cifs_dbg(VFS, "%s: Failed to alloc IV", __func__); + goto free_sg; + } + iv[0] = 3; + memcpy(iv + 1, (char *)tr_hdr->Nonce, SMB3_AES128CMM_NONCE); + + aead_request_set_crypt(req, sg, sg, crypt_len, iv); + aead_request_set_ad(req, assoc_data_len); + + aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, + cifs_crypt_complete, &result); + + rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req); + + if (rc == -EINPROGRESS || rc == -EBUSY) { + wait_for_completion(&result.completion); + rc = result.err; + } + + if (!rc && enc) + memcpy(&tr_hdr->Signature, sign, SMB2_SIGNATURE_SIZE); + + kfree(iv); +free_sg: + kfree(sg); +free_req: + kfree(req); + return rc; +} + +static int +smb3_init_transform_rq(struct TCP_Server_Info *server, struct smb_rqst *new_rq, + struct smb_rqst *old_rq) +{ + struct kvec *iov; + struct page **pages; + struct smb2_transform_hdr *tr_hdr; + unsigned int npages = old_rq->rq_npages; + int i; + int rc = -ENOMEM; + + pages = kmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); + if (!pages) + return rc; + + new_rq->rq_pages = pages; + new_rq->rq_npages = old_rq->rq_npages; + new_rq->rq_pagesz = old_rq->rq_pagesz; + new_rq->rq_tailsz = old_rq->rq_tailsz; + + for (i = 0; i < npages; i++) { + pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM); + if (!pages[i]) + goto err_free_pages; + } + + iov = kmalloc_array(old_rq->rq_nvec, sizeof(struct kvec), GFP_KERNEL); + if (!iov) + goto err_free_pages; + + /* copy all iovs from the old except the 1st one (rfc1002 length) */ + memcpy(&iov[1], &old_rq->rq_iov[1], + sizeof(struct kvec) * (old_rq->rq_nvec - 1)); + new_rq->rq_iov = iov; + new_rq->rq_nvec = old_rq->rq_nvec; + + tr_hdr = kmalloc(sizeof(struct smb2_transform_hdr), GFP_KERNEL); + if (!tr_hdr) + goto err_free_iov; + + /* fill the 1st iov with a transform header */ + fill_transform_hdr(tr_hdr, old_rq); + new_rq->rq_iov[0].iov_base = tr_hdr; + new_rq->rq_iov[0].iov_len = sizeof(struct smb2_transform_hdr); + + /* copy pages form the old */ + for (i = 0; i < npages; i++) { + char *dst = kmap(new_rq->rq_pages[i]); + char *src = kmap(old_rq->rq_pages[i]); + unsigned int len = (i < npages - 1) ? new_rq->rq_pagesz : + new_rq->rq_tailsz; + memcpy(dst, src, len); + kunmap(new_rq->rq_pages[i]); + kunmap(old_rq->rq_pages[i]); + } + + rc = crypt_message(server, new_rq, 1); + cifs_dbg(FYI, "encrypt message returned %d", rc); + if (rc) + goto err_free_tr_hdr; + + return rc; + +err_free_tr_hdr: + kfree(tr_hdr); +err_free_iov: + kfree(iov); +err_free_pages: + for (i = i - 1; i >= 0; i--) + put_page(pages[i]); + kfree(pages); + return rc; +} + +static void +smb3_free_transform_rq(struct smb_rqst *rqst) +{ + int i = rqst->rq_npages - 1; + + for (; i >= 0; i--) + put_page(rqst->rq_pages[i]); + kfree(rqst->rq_pages); + /* free transform header */ + kfree(rqst->rq_iov[0].iov_base); + kfree(rqst->rq_iov); +} + struct smb_version_operations smb20_operations = { .compare_fids = smb2_compare_fids, .setup_request = smb2_setup_request, @@ -1793,6 +2045,8 @@ struct smb_version_operations smb30_operations = { .dir_needs_close = smb2_dir_needs_close, .fallocate = smb3_fallocate, .enum_snapshots = smb3_enum_snapshots, + .init_transform_rq = smb3_init_transform_rq, + .free_transform_rq = smb3_free_transform_rq, }; #ifdef CONFIG_CIFS_SMB311 @@ -1881,6 +2135,8 @@ struct smb_version_operations smb311_operations = { .dir_needs_close = smb2_dir_needs_close, .fallocate = smb3_fallocate, .enum_snapshots = smb3_enum_snapshots, + .init_transform_rq = smb3_init_transform_rq, + .free_transform_rq = smb3_free_transform_rq, }; #endif /* CIFS_SMB311 */ |