diff options
author | Pedro Martelletto <pedro@cvs.openbsd.org> | 2006-08-04 12:35:58 +0000 |
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committer | Pedro Martelletto <pedro@cvs.openbsd.org> | 2006-08-04 12:35:58 +0000 |
commit | 29d4b9c33e298d700a526b9c4a65dd4a49c5945f (patch) | |
tree | 8a00f7e5df0197450859334279fb6fda0cc563d2 /sys/nfs | |
parent | 8e8fe6daa4a7b238cd227f2b3a5f4f487517664f (diff) |
Fix up mbuf length and do 64-bit alignment where needed, joint work
with Nicholas Marriott <nicm__@ntlworld.com>, closes PR 5036
Diffstat (limited to 'sys/nfs')
-rw-r--r-- | sys/nfs/nfs_socket.c | 59 |
1 files changed, 54 insertions, 5 deletions
diff --git a/sys/nfs/nfs_socket.c b/sys/nfs/nfs_socket.c index 77fa523d219..74b88487179 100644 --- a/sys/nfs/nfs_socket.c +++ b/sys/nfs/nfs_socket.c @@ -1,4 +1,4 @@ -/* $OpenBSD: nfs_socket.c,v 1.43 2006/01/24 15:06:41 aaron Exp $ */ +/* $OpenBSD: nfs_socket.c,v 1.44 2006/08/04 12:35:57 pedro Exp $ */ /* $NetBSD: nfs_socket.c,v 1.27 1996/04/15 20:20:00 thorpej Exp $ */ /* @@ -133,6 +133,7 @@ int nfsrtton = 0; struct nfsrtt nfsrtt; void nfs_realign(struct mbuf **, int); +void nfs_realign_fixup(struct mbuf *, struct mbuf *, unsigned int *); unsigned int nfs_realign_test = 0; unsigned int nfs_realign_count = 0; @@ -1454,20 +1455,60 @@ nfs_rcvunlock(flagp) } /* - * NFS parsing code requires 32-bit alignment + * Auxiliary routine to align the length of mbuf copies made with m_copyback(). + */ +void +nfs_realign_fixup(struct mbuf *m, struct mbuf *n, unsigned int *off) +{ + size_t padding; + + /* + * The maximum number of bytes that m_copyback() places in a mbuf is + * always an aligned quantity, so realign happens at the chain's tail. + */ + while (n->m_next != NULL) + n = n->m_next; + + /* + * Pad from the next elements in the source chain. Loop until the + * destination chain is aligned, or the end of the source is reached. + */ + do { + m = m->m_next; + if (m == NULL) + return; + + padding = min(ALIGN(n->m_len) - n->m_len, m->m_len); + if (padding > M_TRAILINGSPACE(n)) + panic("nfs_realign_fixup: no memory to pad to"); + + bcopy(mtod(m, void *), mtod(n, char *) + n->m_len, padding); + + n->m_len += padding; + m_adj(m, padding); + *off += padding; + + } while (!ALIGNED_POINTER(n->m_len, void *)); +} + +/* + * The NFS RPC parsing code uses the data address and the length of mbuf + * structures to calculate on-memory addresses. This function makes sure these + * parameters are correctly aligned. */ void nfs_realign(struct mbuf **pm, int hsiz) { struct mbuf *m; struct mbuf *n = NULL; - int off = 0; + unsigned int off = 0; ++nfs_realign_test; while ((m = *pm) != NULL) { - if ((m->m_len & 0x3) || (mtod(m, long) & 0x3)) { + if (!ALIGNED_POINTER(m->m_data, void *) || + !ALIGNED_POINTER(m->m_len, void *)) { MGET(n, M_WAIT, MT_DATA); - if (m->m_len >= MINCLSIZE) { + if (ALIGN(m->m_len) >= MINCLSIZE) { MCLGET(n, M_WAIT); } n->m_len = 0; @@ -1483,6 +1524,14 @@ nfs_realign(struct mbuf **pm, int hsiz) ++nfs_realign_count; while (m) { m_copyback(n, off, m->m_len, mtod(m, caddr_t)); + + /* + * If an unaligned amount of memory was copied, fix up + * the last mbuf created by m_copyback(). + */ + if (!ALIGNED_POINTER(m->m_len, void *)) + nfs_realign_fixup(m, n, &off); + off += m->m_len; m = m->m_next; } |