diff options
Diffstat (limited to 'crypto/scatterwalk.c')
| -rw-r--r-- | crypto/scatterwalk.c | 248 |
1 files changed, 0 insertions, 248 deletions
diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c index b95e5974e327..be0e24843806 100644 --- a/crypto/scatterwalk.c +++ b/crypto/scatterwalk.c @@ -10,25 +10,10 @@ */ #include <crypto/scatterwalk.h> -#include <linux/crypto.h> -#include <linux/errno.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/scatterlist.h> -#include <linux/slab.h> - -enum { - SKCIPHER_WALK_SLOW = 1 << 0, - SKCIPHER_WALK_COPY = 1 << 1, - SKCIPHER_WALK_DIFF = 1 << 2, - SKCIPHER_WALK_SLEEP = 1 << 3, -}; - -static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk) -{ - return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC; -} void scatterwalk_skip(struct scatter_walk *walk, unsigned int nbytes) { @@ -217,236 +202,3 @@ struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2], return dst; } EXPORT_SYMBOL_GPL(scatterwalk_ffwd); - -static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize) -{ - unsigned alignmask = walk->alignmask; - unsigned n; - void *buffer; - - if (!walk->buffer) - walk->buffer = walk->page; - buffer = walk->buffer; - if (!buffer) { - /* Min size for a buffer of bsize bytes aligned to alignmask */ - n = bsize + (alignmask & ~(crypto_tfm_ctx_alignment() - 1)); - - buffer = kzalloc(n, skcipher_walk_gfp(walk)); - if (!buffer) - return skcipher_walk_done(walk, -ENOMEM); - walk->buffer = buffer; - } - - buffer = PTR_ALIGN(buffer, alignmask + 1); - memcpy_from_scatterwalk(buffer, &walk->in, bsize); - walk->out.__addr = buffer; - walk->in.__addr = walk->out.addr; - - walk->nbytes = bsize; - walk->flags |= SKCIPHER_WALK_SLOW; - - return 0; -} - -static int skcipher_next_copy(struct skcipher_walk *walk) -{ - void *tmp = walk->page; - - scatterwalk_map(&walk->in); - memcpy(tmp, walk->in.addr, walk->nbytes); - scatterwalk_unmap(&walk->in); - /* - * walk->in is advanced later when the number of bytes actually - * processed (which might be less than walk->nbytes) is known. - */ - - walk->in.__addr = tmp; - walk->out.__addr = tmp; - return 0; -} - -static int skcipher_next_fast(struct skcipher_walk *walk) -{ - unsigned long diff; - - diff = offset_in_page(walk->in.offset) - - offset_in_page(walk->out.offset); - diff |= (u8 *)(sg_page(walk->in.sg) + (walk->in.offset >> PAGE_SHIFT)) - - (u8 *)(sg_page(walk->out.sg) + (walk->out.offset >> PAGE_SHIFT)); - - scatterwalk_map(&walk->out); - walk->in.__addr = walk->out.__addr; - - if (diff) { - walk->flags |= SKCIPHER_WALK_DIFF; - scatterwalk_map(&walk->in); - } - - return 0; -} - -static int skcipher_walk_next(struct skcipher_walk *walk) -{ - unsigned int bsize; - unsigned int n; - - n = walk->total; - bsize = min(walk->stride, max(n, walk->blocksize)); - n = scatterwalk_clamp(&walk->in, n); - n = scatterwalk_clamp(&walk->out, n); - - if (unlikely(n < bsize)) { - if (unlikely(walk->total < walk->blocksize)) - return skcipher_walk_done(walk, -EINVAL); - -slow_path: - return skcipher_next_slow(walk, bsize); - } - walk->nbytes = n; - - if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) { - if (!walk->page) { - gfp_t gfp = skcipher_walk_gfp(walk); - - walk->page = (void *)__get_free_page(gfp); - if (!walk->page) - goto slow_path; - } - walk->flags |= SKCIPHER_WALK_COPY; - return skcipher_next_copy(walk); - } - - return skcipher_next_fast(walk); -} - -static int skcipher_copy_iv(struct skcipher_walk *walk) -{ - unsigned alignmask = walk->alignmask; - unsigned ivsize = walk->ivsize; - unsigned aligned_stride = ALIGN(walk->stride, alignmask + 1); - unsigned size; - u8 *iv; - - /* Min size for a buffer of stride + ivsize, aligned to alignmask */ - size = aligned_stride + ivsize + - (alignmask & ~(crypto_tfm_ctx_alignment() - 1)); - - walk->buffer = kmalloc(size, skcipher_walk_gfp(walk)); - if (!walk->buffer) - return -ENOMEM; - - iv = PTR_ALIGN(walk->buffer, alignmask + 1) + aligned_stride; - - walk->iv = memcpy(iv, walk->iv, walk->ivsize); - return 0; -} - -int skcipher_walk_first(struct skcipher_walk *walk, bool atomic) -{ - if (WARN_ON_ONCE(in_hardirq())) - return -EDEADLK; - - walk->flags = atomic ? 0 : SKCIPHER_WALK_SLEEP; - - walk->buffer = NULL; - if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { - int err = skcipher_copy_iv(walk); - if (err) - return err; - } - - walk->page = NULL; - - return skcipher_walk_next(walk); -} -EXPORT_SYMBOL_GPL(skcipher_walk_first); - -/** - * skcipher_walk_done() - finish one step of a skcipher_walk - * @walk: the skcipher_walk - * @res: number of bytes *not* processed (>= 0) from walk->nbytes, - * or a -errno value to terminate the walk due to an error - * - * This function cleans up after one step of walking through the source and - * destination scatterlists, and advances to the next step if applicable. - * walk->nbytes is set to the number of bytes available in the next step, - * walk->total is set to the new total number of bytes remaining, and - * walk->{src,dst}.virt.addr is set to the next pair of data pointers. If there - * is no more data, or if an error occurred (i.e. -errno return), then - * walk->nbytes and walk->total are set to 0 and all resources owned by the - * skcipher_walk are freed. - * - * Return: 0 or a -errno value. If @res was a -errno value then it will be - * returned, but other errors may occur too. - */ -int skcipher_walk_done(struct skcipher_walk *walk, int res) -{ - unsigned int n = walk->nbytes; /* num bytes processed this step */ - unsigned int total = 0; /* new total remaining */ - - if (!n) - goto finish; - - if (likely(res >= 0)) { - n -= res; /* subtract num bytes *not* processed */ - total = walk->total - n; - } - - if (likely(!(walk->flags & (SKCIPHER_WALK_SLOW | - SKCIPHER_WALK_COPY | - SKCIPHER_WALK_DIFF)))) { - scatterwalk_advance(&walk->in, n); - } else if (walk->flags & SKCIPHER_WALK_DIFF) { - scatterwalk_done_src(&walk->in, n); - } else if (walk->flags & SKCIPHER_WALK_COPY) { - scatterwalk_advance(&walk->in, n); - scatterwalk_map(&walk->out); - memcpy(walk->out.addr, walk->page, n); - } else { /* SKCIPHER_WALK_SLOW */ - if (res > 0) { - /* - * Didn't process all bytes. Either the algorithm is - * broken, or this was the last step and it turned out - * the message wasn't evenly divisible into blocks but - * the algorithm requires it. - */ - res = -EINVAL; - total = 0; - } else - memcpy_to_scatterwalk(&walk->out, walk->out.addr, n); - goto dst_done; - } - - scatterwalk_done_dst(&walk->out, n); -dst_done: - - if (res > 0) - res = 0; - - walk->total = total; - walk->nbytes = 0; - - if (total) { - if (walk->flags & SKCIPHER_WALK_SLEEP) - cond_resched(); - walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY | - SKCIPHER_WALK_DIFF); - return skcipher_walk_next(walk); - } - -finish: - /* Short-circuit for the common/fast path. */ - if (!((unsigned long)walk->buffer | (unsigned long)walk->page)) - goto out; - - if (walk->iv != walk->oiv) - memcpy(walk->oiv, walk->iv, walk->ivsize); - if (walk->buffer != walk->page) - kfree(walk->buffer); - if (walk->page) - free_page((unsigned long)walk->page); - -out: - return res; -} -EXPORT_SYMBOL_GPL(skcipher_walk_done); |
