diff options
Diffstat (limited to 'fs/cifs/cifsencrypt.c')
-rw-r--r-- | fs/cifs/cifsencrypt.c | 172 |
1 files changed, 150 insertions, 22 deletions
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c index cbc18b4a9cb2..357bd27a7fd1 100644 --- a/fs/cifs/cifsencrypt.c +++ b/fs/cifs/cifsencrypt.c @@ -24,12 +24,156 @@ #include "../smbfs_common/arc4.h" #include <crypto/aead.h> +/* + * Hash data from a BVEC-type iterator. + */ +static int cifs_shash_bvec(const struct iov_iter *iter, ssize_t maxsize, + struct shash_desc *shash) +{ + const struct bio_vec *bv = iter->bvec; + unsigned long start = iter->iov_offset; + unsigned int i; + void *p; + int ret; + + for (i = 0; i < iter->nr_segs; i++) { + size_t off, len; + + len = bv[i].bv_len; + if (start >= len) { + start -= len; + continue; + } + + len = min_t(size_t, maxsize, len - start); + off = bv[i].bv_offset + start; + + p = kmap_local_page(bv[i].bv_page); + ret = crypto_shash_update(shash, p + off, len); + kunmap_local(p); + if (ret < 0) + return ret; + + maxsize -= len; + if (maxsize <= 0) + break; + start = 0; + } + + return 0; +} + +/* + * Hash data from a KVEC-type iterator. + */ +static int cifs_shash_kvec(const struct iov_iter *iter, ssize_t maxsize, + struct shash_desc *shash) +{ + const struct kvec *kv = iter->kvec; + unsigned long start = iter->iov_offset; + unsigned int i; + int ret; + + for (i = 0; i < iter->nr_segs; i++) { + size_t len; + + len = kv[i].iov_len; + if (start >= len) { + start -= len; + continue; + } + + len = min_t(size_t, maxsize, len - start); + ret = crypto_shash_update(shash, kv[i].iov_base + start, len); + if (ret < 0) + return ret; + maxsize -= len; + + if (maxsize <= 0) + break; + start = 0; + } + + return 0; +} + +/* + * Hash data from an XARRAY-type iterator. + */ +static ssize_t cifs_shash_xarray(const struct iov_iter *iter, ssize_t maxsize, + struct shash_desc *shash) +{ + struct folio *folios[16], *folio; + unsigned int nr, i, j, npages; + loff_t start = iter->xarray_start + iter->iov_offset; + pgoff_t last, index = start / PAGE_SIZE; + ssize_t ret = 0; + size_t len, offset, foffset; + void *p; + + if (maxsize == 0) + return 0; + + last = (start + maxsize - 1) / PAGE_SIZE; + do { + nr = xa_extract(iter->xarray, (void **)folios, index, last, + ARRAY_SIZE(folios), XA_PRESENT); + if (nr == 0) + return -EIO; + + for (i = 0; i < nr; i++) { + folio = folios[i]; + npages = folio_nr_pages(folio); + foffset = start - folio_pos(folio); + offset = foffset % PAGE_SIZE; + for (j = foffset / PAGE_SIZE; j < npages; j++) { + len = min_t(size_t, maxsize, PAGE_SIZE - offset); + p = kmap_local_page(folio_page(folio, j)); + ret = crypto_shash_update(shash, p, len); + kunmap_local(p); + if (ret < 0) + return ret; + maxsize -= len; + if (maxsize <= 0) + return 0; + start += len; + offset = 0; + index++; + } + } + } while (nr == ARRAY_SIZE(folios)); + return 0; +} + +/* + * Pass the data from an iterator into a hash. + */ +static int cifs_shash_iter(const struct iov_iter *iter, size_t maxsize, + struct shash_desc *shash) +{ + if (maxsize == 0) + return 0; + + switch (iov_iter_type(iter)) { + case ITER_BVEC: + return cifs_shash_bvec(iter, maxsize, shash); + case ITER_KVEC: + return cifs_shash_kvec(iter, maxsize, shash); + case ITER_XARRAY: + return cifs_shash_xarray(iter, maxsize, shash); + default: + pr_err("cifs_shash_iter(%u) unsupported\n", iov_iter_type(iter)); + WARN_ON_ONCE(1); + return -EIO; + } +} + int __cifs_calc_signature(struct smb_rqst *rqst, - struct TCP_Server_Info *server, char *signature, - struct shash_desc *shash) + struct TCP_Server_Info *server, char *signature, + struct shash_desc *shash) { int i; - int rc; + ssize_t rc; struct kvec *iov = rqst->rq_iov; int n_vec = rqst->rq_nvec; @@ -61,25 +205,9 @@ int __cifs_calc_signature(struct smb_rqst *rqst, } } - /* now hash over the rq_pages array */ - for (i = 0; i < rqst->rq_npages; i++) { - void *kaddr; - unsigned int len, offset; - - rqst_page_get_length(rqst, i, &len, &offset); - - kaddr = (char *) kmap(rqst->rq_pages[i]) + offset; - - rc = crypto_shash_update(shash, kaddr, len); - if (rc) { - cifs_dbg(VFS, "%s: Could not update with payload\n", - __func__); - kunmap(rqst->rq_pages[i]); - return rc; - } - - kunmap(rqst->rq_pages[i]); - } + rc = cifs_shash_iter(&rqst->rq_iter, iov_iter_count(&rqst->rq_iter), shash); + if (rc < 0) + return rc; rc = crypto_shash_final(shash, signature); if (rc) |