[src/trunk]: src/sys/netipsec Make sure the mbufs in the input path (only the...

[drochner <drochner%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/55dd59c7bc17
branches:  trunk
changeset: 773054:55dd59c7bc17
user:      drochner <drochner%NetBSD.org@localhost>
date:      Wed Jan 25 20:31:23 2012 +0000

description:
Make sure the mbufs in the input path (only the parts which we are going
to modify in the AH case) are writable/non-shared.
This addresses PR kern/33162 by Jeff Rizzo, and replaces the insufficient
patch from that time by a radical solution.
(The PR's problem had been worked around by rev.1.3 of xennetback_xenbus.c,
so it needs a network driver modification to reproduce it.)
Being here, clarify a bit of ipcomp -- uncompression is done in-place,
the header must be removed explicitly.

diffstat:

 sys/netipsec/xform_ah.c     |  18 +++++++++++++-----
 sys/netipsec/xform_esp.c    |  26 ++++++++++++++------------
 sys/netipsec/xform_ipcomp.c |  19 +++++++++++++++----
 3 files changed, 42 insertions(+), 21 deletions(-)

diffs (160 lines):

diff -r 057db4bc3b66 -r 55dd59c7bc17 sys/netipsec/xform_ah.c
--- a/sys/netipsec/xform_ah.c   Wed Jan 25 20:18:04 2012 +0000
+++ b/sys/netipsec/xform_ah.c   Wed Jan 25 20:31:23 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xform_ah.c,v 1.35 2012/01/24 21:57:03 drochner Exp $   */
+/*     $NetBSD: xform_ah.c,v 1.36 2012/01/25 20:31:23 drochner Exp $   */
 /*     $FreeBSD: src/sys/netipsec/xform_ah.c,v 1.1.4.1 2003/01/24 05:11:36 sam Exp $   */
 /*     $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */
 /*
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xform_ah.c,v 1.35 2012/01/24 21:57:03 drochner Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xform_ah.c,v 1.36 2012/01/25 20:31:23 drochner Exp $");
 
 #include "opt_inet.h"
 #ifdef __FreeBSD__
@@ -641,7 +641,7 @@
        struct tdb_crypto *tc;
        struct m_tag *mtag;
        struct newah *ah;
-       int hl, rplen, authsize;
+       int hl, rplen, authsize, error;
 
        struct cryptodesc *crda;
        struct cryptop *crp;
@@ -746,10 +746,18 @@
                return ENOBUFS;
        }
 
+       error = m_makewritable(&m, 0, skip + rplen + authsize, M_NOWAIT);
+       if (error) {
+               m_freem(m);
+               DPRINTF(("ah_input: failed to copyback_cow\n"));
+               AH_STATINC(AH_STAT_HDROPS);
+               free(tc, M_XDATA);
+               crypto_freereq(crp);
+               return error;
+       }
+
        /* Only save information if crypto processing is needed. */
        if (mtag == NULL) {
-               int error;
-
                /*
                 * Save the authenticator, the skipped portion of the packet,
                 * and the AH header.
diff -r 057db4bc3b66 -r 55dd59c7bc17 sys/netipsec/xform_esp.c
--- a/sys/netipsec/xform_esp.c  Wed Jan 25 20:18:04 2012 +0000
+++ b/sys/netipsec/xform_esp.c  Wed Jan 25 20:31:23 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xform_esp.c,v 1.39 2011/08/31 18:31:04 plunky Exp $    */
+/*     $NetBSD: xform_esp.c,v 1.40 2012/01/25 20:31:23 drochner Exp $  */
 /*     $FreeBSD: src/sys/netipsec/xform_esp.c,v 1.2.2.1 2003/01/24 05:11:36 sam Exp $  */
 /*     $OpenBSD: ip_esp.c,v 1.69 2001/06/26 06:18:59 angelos Exp $ */
 
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xform_esp.c,v 1.39 2011/08/31 18:31:04 plunky Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xform_esp.c,v 1.40 2012/01/25 20:31:23 drochner Exp $");
 
 #include "opt_inet.h"
 #ifdef __FreeBSD__
@@ -297,7 +297,7 @@
        const struct enc_xform *espx;
        struct tdb_ident *tdbi;
        struct tdb_crypto *tc;
-       int plen, alen, hlen;
+       int plen, alen, hlen, error;
        struct m_tag *mtag;
        struct newesp *esp;
 
@@ -398,6 +398,16 @@
                return ENOBUFS;
        }
 
+       error = m_makewritable(&m, 0, m->m_pkthdr.len, M_NOWAIT);
+       if (error) {
+               m_freem(m);
+               free(tc, M_XDATA);
+               crypto_freereq(crp);
+               DPRINTF(("esp_input: m_makewritable failed\n"));
+               ESP_STATINC(ESP_STAT_CRYPTO);
+               return error;
+       }
+
        tc->tc_ptr = mtag;
 
        if (esph) {
@@ -681,15 +691,7 @@
        m_adj(m, -(lastthree[1] + 2));
 
        /* Restore the Next Protocol field */
-       m = m_copyback_cow(m, protoff, sizeof (u_int8_t), lastthree + 2,
-                          M_DONTWAIT);
-
-       if (m == NULL) {
-               ESP_STATINC(ESP_STAT_CRYPTO);
-               DPRINTF(("esp_input_cb: failed to allocate mbuf\n"));
-               error = ENOBUFS;
-               goto bad;
-       }
+       m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
 
        IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
 
diff -r 057db4bc3b66 -r 55dd59c7bc17 sys/netipsec/xform_ipcomp.c
--- a/sys/netipsec/xform_ipcomp.c       Wed Jan 25 20:18:04 2012 +0000
+++ b/sys/netipsec/xform_ipcomp.c       Wed Jan 25 20:31:23 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xform_ipcomp.c,v 1.28 2011/05/06 21:48:46 drochner Exp $       */
+/*     $NetBSD: xform_ipcomp.c,v 1.29 2012/01/25 20:31:23 drochner Exp $       */
 /*     $FreeBSD: src/sys/netipsec/xform_ipcomp.c,v 1.1.4.1 2003/01/24 05:11:36 sam Exp $       */
 /* $OpenBSD: ip_ipcomp.c,v 1.1 2001/07/05 12:08:52 jjbg Exp $ */
 
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xform_ipcomp.c,v 1.28 2011/05/06 21:48:46 drochner Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xform_ipcomp.c,v 1.29 2012/01/25 20:31:23 drochner Exp $");
 
 /* IP payload compression protocol (IPComp), see RFC 2393 */
 #include "opt_inet.h"
@@ -152,7 +152,7 @@
        struct tdb_crypto *tc;
        struct cryptodesc *crdc;
        struct cryptop *crp;
-       int hlen = IPCOMP_HLENGTH;
+       int error, hlen = IPCOMP_HLENGTH;
 
        IPSEC_SPLASSERT_SOFTNET("ipcomp_input");
 
@@ -173,11 +173,22 @@
                IPCOMP_STATINC(IPCOMP_STAT_CRYPTO);
                return ENOBUFS;
        }
+
+       error = m_makewritable(&m, 0, m->m_pkthdr.len, M_NOWAIT);
+       if (error) {
+               DPRINTF(("ipcomp_input: m_makewritable failed\n"));
+               m_freem(m);
+               free(tc, M_XDATA);
+               crypto_freereq(crp);
+               IPCOMP_STATINC(IPCOMP_STAT_CRYPTO);
+               return error;
+       }
+
        crdc = crp->crp_desc;
 
        crdc->crd_skip = skip + hlen;
        crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
-       crdc->crd_inject = skip;
+       crdc->crd_inject = 0; /* unused */
 
        tc->tc_ptr = 0;