[src/trunk]: src/sys/net80211 Style, and fix two pretty bad mistakes in the c...

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

details:   https://anonhg.NetBSD.org/src/rev/71738310c4c8
branches:  trunk
changeset: 829118:71738310c4c8
user:      maxv <maxv%NetBSD.org@localhost>
date:      Wed Jan 17 17:41:38 2018 +0000

description:
Style, and fix two pretty bad mistakes in the crypto functions:

 * They call M_PREPEND, but don't pass the updated pointer back to the
   caller.

 * They use memmove on the mbuf data, but they don't ensure that the
   area they touch is contiguous.

This fix is not complete, ieee80211_crypto_encap too needs to pass back
the updated pointer. This will be done in another commit.

diffstat:

 sys/net80211/ieee80211_crypto.c      |  83 +++++++++++++++++++++++------------
 sys/net80211/ieee80211_crypto_ccmp.c |  13 +----
 sys/net80211/ieee80211_crypto_tkip.c |  14 +----
 sys/net80211/ieee80211_crypto_wep.c  |  13 +----
 4 files changed, 62 insertions(+), 61 deletions(-)

diffs (truncated from 310 to 300 lines):

diff -r 489a65805742 -r 71738310c4c8 sys/net80211/ieee80211_crypto.c
--- a/sys/net80211/ieee80211_crypto.c   Wed Jan 17 17:22:14 2018 +0000
+++ b/sys/net80211/ieee80211_crypto.c   Wed Jan 17 17:41:38 2018 +0000
@@ -1,5 +1,6 @@
-/*     $NetBSD: ieee80211_crypto.c,v 1.19 2018/01/16 09:04:30 maxv Exp $       */
-/*-
+/*     $NetBSD: ieee80211_crypto.c,v 1.20 2018/01/17 17:41:38 maxv Exp $       */
+
+/*
  * Copyright (c) 2001 Atsushi Onoe
  * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
  * All rights reserved.
@@ -36,7 +37,7 @@
 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto.c,v 1.12 2005/08/08 18:46:35 sam Exp $");
 #endif
 #ifdef __NetBSD__
-__KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto.c,v 1.19 2018/01/16 09:04:30 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto.c,v 1.20 2018/01/17 17:41:38 maxv Exp $");
 #endif
 
 #ifdef _KERNEL_OPT
@@ -68,22 +69,22 @@
 /*
  * Table of registered cipher modules.
  */
-static const struct ieee80211_cipher *ciphers[IEEE80211_CIPHER_MAX];
+static const struct ieee80211_cipher *ciphers[IEEE80211_CIPHER_MAX];
 
 #ifdef INET
 #include <netinet/in.h> 
 #include <net/if_ether.h>
 #endif
 
-static int _ieee80211_crypto_delkey(struct ieee80211com *,
-               struct ieee80211_key *);
+static int _ieee80211_crypto_delkey(struct ieee80211com *,
+    struct ieee80211_key *);
 
 /*
  * Default "null" key management routines.
  */
 static int
 null_key_alloc(struct ieee80211com *ic, const struct ieee80211_key *k,
-       ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
+    ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
 {
        if (!(&ic->ic_nw_keys[0] <= k &&
             k < &ic->ic_nw_keys[IEEE80211_WEP_NKID])) {
@@ -106,20 +107,25 @@
        *rxkeyix = IEEE80211_KEYIX_NONE;        /* XXX maybe *keyix? */
        return 1;
 }
+
 static int
-null_key_delete(struct ieee80211com *ic,
-    const struct ieee80211_key *k)
+null_key_delete(struct ieee80211com *ic, const struct ieee80211_key *k)
 {
        return 1;
 }
-static         int
-null_key_set(struct ieee80211com *ic,
-    const struct ieee80211_key *k,
+
+static int
+null_key_set(struct ieee80211com *ic, const struct ieee80211_key *k,
     const u_int8_t mac[IEEE80211_ADDR_LEN])
 {
        return 1;
 }
-static void null_key_update(struct ieee80211com *ic) {}
+
+static void
+null_key_update(struct ieee80211com *ic)
+{
+       ;
+}
 
 /*
  * Write-arounds for common operations.
@@ -134,23 +140,21 @@
  * Wrappers for driver key management methods.
  */
 static __inline int
-dev_key_alloc(struct ieee80211com *ic,
-       const struct ieee80211_key *key,
-       ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
+dev_key_alloc(struct ieee80211com *ic, const struct ieee80211_key *key,
+    ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
 {
        return ic->ic_crypto.cs_key_alloc(ic, key, keyix, rxkeyix);
 }
 
 static __inline int
-dev_key_delete(struct ieee80211com *ic,
-       const struct ieee80211_key *key)
+dev_key_delete(struct ieee80211com *ic, const struct ieee80211_key *key)
 {
        return ic->ic_crypto.cs_key_delete(ic, key);
 }
 
 static __inline int
 dev_key_set(struct ieee80211com *ic, const struct ieee80211_key *key,
-       const u_int8_t mac[IEEE80211_ADDR_LEN])
+    const u_int8_t mac[IEEE80211_ADDR_LEN])
 {
        return ic->ic_crypto.cs_key_set(ic, key, mac);
 }
@@ -260,8 +264,8 @@
  *     ieee80211_key_update_end(ic);
  */
 int
-ieee80211_crypto_newkey(struct ieee80211com *ic,
-       int cipher, int flags, struct ieee80211_key *key)
+ieee80211_crypto_newkey(struct ieee80211com *ic, int cipher, int flags,
+    struct ieee80211_key *key)
 {
 #define        N(a)    (sizeof(a) / sizeof(a[0]))
        const struct ieee80211_cipher *cip;
@@ -279,6 +283,7 @@
                return 0;
        }
        cip = ciphers[cipher];
+
        if (cip == NULL) {
                /*
                 * Auto-load cipher module if we have a well-known name
@@ -311,9 +316,10 @@
 
        oflags = key->wk_flags;
        flags &= IEEE80211_KEY_COMMON;
+
        /*
         * If the hardware does not support the cipher then
-        * fallback to a host-based implementation.
+        * fall back to a host-based implementation.
         */
        if ((ic->ic_caps & (1<<cipher)) == 0) {
                IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
@@ -321,6 +327,7 @@
                    __func__, cip->ic_name);
                flags |= IEEE80211_KEY_SWCRYPT;
        }
+
        /*
         * Hardware TKIP with software MIC is an important
         * combination; we handle it by flagging each key,
@@ -473,7 +480,7 @@
 
        ieee80211_key_update_begin(ic);
        for (i = 0; i < IEEE80211_WEP_NKID; i++)
-               (void) _ieee80211_crypto_delkey(ic, &ic->ic_nw_keys[i]);
+               (void)_ieee80211_crypto_delkey(ic, &ic->ic_nw_keys[i]);
        ieee80211_key_update_end(ic);
 }
 
@@ -486,7 +493,7 @@
  */
 int
 ieee80211_crypto_setkey(struct ieee80211com *ic, struct ieee80211_key *key,
-               const u_int8_t macaddr[IEEE80211_ADDR_LEN])
+    const u_int8_t macaddr[IEEE80211_ADDR_LEN])
 {
        const struct ieee80211_cipher *cip = key->wk_cipher;
 
@@ -524,13 +531,14 @@
  * Add privacy headers appropriate for the specified key.
  */
 struct ieee80211_key *
-ieee80211_crypto_encap(struct ieee80211com *ic,
-       struct ieee80211_node *ni, struct mbuf *m)
+ieee80211_crypto_encap(struct ieee80211com *ic, struct ieee80211_node *ni,
+    struct mbuf *m)
 {
        struct ieee80211_key *k;
        struct ieee80211_frame *wh;
        const struct ieee80211_cipher *cip;
-       u_int8_t keyid;
+       u_int8_t keyid, *hdr;
+       int hdrlen;
 
        /*
         * Multicast traffic always uses the multicast key.
@@ -556,6 +564,25 @@
                k = &ni->ni_ucastkey;
        }
        cip = k->wk_cipher;
+
+       /*
+        * The crypto header is added after the IEEE802.11 header. Prepend
+        * the size of the crypto header, and move the IEEE802.11 header back
+        * to the beginning of the mbuf. Ensure everything is contiguous.
+        */
+       hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
+       M_PREPEND(m, cip->ic_header, M_NOWAIT);
+       if (m && m->m_len < hdrlen + cip->ic_header) {
+               m = m_pullup(m, hdrlen + cip->ic_header);
+       }
+       if (m == NULL) {
+               return NULL;
+       }
+       hdr = mtod(m, u_int8_t *);
+       memmove(hdr, hdr + cip->ic_header, hdrlen);
+
+       /* XXX pass the updated pointer back to the caller */
+
        return (cip->ic_encap(k, m, keyid<<6) ? k : NULL);
 }
 
@@ -570,7 +597,7 @@
  */
 struct ieee80211_key *
 ieee80211_crypto_decap(struct ieee80211com *ic,
-       struct ieee80211_node *ni, struct mbuf **mp, int hdrlen)
+    struct ieee80211_node *ni, struct mbuf **mp, int hdrlen)
 {
        const struct ieee80211_cipher *cip;
        struct ieee80211_key *k;
diff -r 489a65805742 -r 71738310c4c8 sys/net80211/ieee80211_crypto_ccmp.c
--- a/sys/net80211/ieee80211_crypto_ccmp.c      Wed Jan 17 17:22:14 2018 +0000
+++ b/sys/net80211/ieee80211_crypto_ccmp.c      Wed Jan 17 17:41:38 2018 +0000
@@ -34,7 +34,7 @@
 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto_ccmp.c,v 1.7 2005/07/11 03:06:23 sam Exp $");
 #endif
 #ifdef __NetBSD__
-__KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_ccmp.c,v 1.11 2014/10/18 08:33:29 snj Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_ccmp.c,v 1.12 2018/01/17 17:41:38 maxv Exp $");
 #endif
 
 /*
@@ -148,16 +148,7 @@
        int hdrlen;
 
        hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
-
-       /*
-        * Copy down 802.11 header and add the IV, KeyID, and ExtIV.
-        */
-       M_PREPEND(m, ccmp.ic_header, M_NOWAIT);
-       if (m == NULL)
-               return 0;
-       ivp = mtod(m, u_int8_t *);
-       ovbcopy(ivp + ccmp.ic_header, ivp, hdrlen);
-       ivp += hdrlen;
+       ivp = mtod(m, u_int8_t *) + hdrlen;
 
        k->wk_keytsc++;         /* XXX wrap at 48 bits */
        ivp[0] = k->wk_keytsc >> 0;             /* PN0 */
diff -r 489a65805742 -r 71738310c4c8 sys/net80211/ieee80211_crypto_tkip.c
--- a/sys/net80211/ieee80211_crypto_tkip.c      Wed Jan 17 17:22:14 2018 +0000
+++ b/sys/net80211/ieee80211_crypto_tkip.c      Wed Jan 17 17:41:38 2018 +0000
@@ -34,7 +34,7 @@
 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto_tkip.c,v 1.10 2005/08/08 18:46:35 sam Exp $");
 #endif
 #ifdef __NetBSD__
-__KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_tkip.c,v 1.12 2014/10/18 08:33:29 snj Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_tkip.c,v 1.13 2018/01/17 17:41:38 maxv Exp $");
 #endif
 
 /*
@@ -175,17 +175,9 @@
                ic->ic_stats.is_crypto_tkipcm++;
                return 0;
        }
+
        hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
-
-       /*
-        * Copy down 802.11 header and add the IV, KeyID, and ExtIV.
-        */
-       M_PREPEND(m, tkip.ic_header, M_NOWAIT);
-       if (m == NULL)
-               return 0;
-       ivp = mtod(m, u_int8_t *);
-       memmove(ivp, ivp + tkip.ic_header, hdrlen);
-       ivp += hdrlen;
+       ivp = mtod(m, u_int8_t *) + hdrlen;
 
        ivp[0] = k->wk_keytsc >> 8;             /* TSC1 */
        ivp[1] = (ivp[0] | 0x20) & 0x7f;        /* WEP seed */
diff -r 489a65805742 -r 71738310c4c8 sys/net80211/ieee80211_crypto_wep.c
--- a/sys/net80211/ieee80211_crypto_wep.c       Wed Jan 17 17:22:14 2018 +0000
+++ b/sys/net80211/ieee80211_crypto_wep.c       Wed Jan 17 17:41:38 2018 +0000
@@ -34,7 +34,7 @@
 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto_wep.c,v 1.7 2005/06/10 16:11:24 sam Exp $");
 #endif
 #ifdef __NetBSD__
-__KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_wep.c,v 1.9 2016/10/09 14:50:20 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_wep.c,v 1.10 2018/01/17 17:41:38 maxv Exp $");
 #endif
 
 /*
@@ -132,16 +132,7 @@
        int hdrlen;
 
        hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
-
-       /*
-        * Copy down 802.11 header and add the IV + KeyID.
-        */