Move code that does payload realigment to a new routine, ieee80211_realign,

so it can be reused.  While here rewrite the logic to always use a single mbuf.

Reviewed by:	rpaulo
Approved by:	re (kib)

4 files changed, 44 insertions, 48 deletions

diff --git a/sys/net80211/ieee80211_freebsd.c b/sys/net80211/ieee80211_freebsd.c
index ee3022f..51a86fd 100644
--- a/sys/net80211/ieee80211_freebsd.c
+++ b/sys/net80211/ieee80211_freebsd.c
@@ -53,6 +53,7 @@ __FBSDID("$FreeBSD$");
 #include <net/route.h>
 
 #include <net80211/ieee80211_var.h>
+#include <net80211/ieee80211_input.h>
 
 SYSCTL_NODE(_net, OID_AUTO, wlan, CTLFLAG_RD, 0, "IEEE 80211 parameters");
 
@@ -408,6 +409,43 @@ ieee80211_getmgtframe(uint8_t **frm, int headroom, int pktlen)
 	return m;
 }
 
+/*
+ * Re-align the payload in the mbuf.  This is mainly used (right now)
+ * to handle IP header alignment requirements on certain architectures.
+ */
+struct mbuf *
+ieee80211_realign(struct ieee80211vap *vap, struct mbuf *m, size_t align)
+{
+	int pktlen, space;
+	struct mbuf *n;
+
+	pktlen = m->m_pkthdr.len;
+	space = pktlen + align;
+	if (space < MINCLSIZE)
+		n = m_gethdr(M_DONTWAIT, MT_DATA);
+	else {
+		n = m_getjcl(M_DONTWAIT, MT_DATA, M_PKTHDR,
+		    space <= MCLBYTES ?     MCLBYTES :
+#if MJUMPAGESIZE != MCLBYTES
+		    space <= MJUMPAGESIZE ? MJUMPAGESIZE :
+#endif
+		    space <= MJUM9BYTES ?   MJUM9BYTES : MJUM16BYTES);
+	}
+	if (__predict_true(n != NULL)) {
+		m_move_pkthdr(n, m);
+		n->m_data = (caddr_t)(ALIGN(n->m_data + align) - align);
+		m_copydata(m, 0, pktlen, mtod(n, caddr_t));
+		n->m_len = pktlen;
+	} else {
+		IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY,
+		    mtod(m, const struct ieee80211_frame *), NULL,
+		    "%s", "no mbuf to realign");
+		vap->iv_stats.is_rx_badalign++;
+	}
+	m_freem(m);
+	return n;
+}
+
 int
 ieee80211_add_callback(struct mbuf *m,
 	void (*func)(struct ieee80211_node *, void *, int), void *arg)
diff --git a/sys/net80211/ieee80211_input.c b/sys/net80211/ieee80211_input.c
index 8209d2e..b2b6368 100644
--- a/sys/net80211/ieee80211_input.c
+++ b/sys/net80211/ieee80211_input.c
@@ -285,53 +285,9 @@ ieee80211_decap(struct ieee80211vap *vap, struct mbuf *m, int hdrlen)
 	}
 #ifdef ALIGNED_POINTER
 	if (!ALIGNED_POINTER(mtod(m, caddr_t) + sizeof(*eh), uint32_t)) {
-		struct mbuf *n, *n0, **np;
-		caddr_t newdata;
-		int off, pktlen;
-
-		n0 = NULL;
-		np = &n0;
-		off = 0;
-		pktlen = m->m_pkthdr.len;
-		while (pktlen > off) {
-			if (n0 == NULL) {
-				MGETHDR(n, M_DONTWAIT, MT_DATA);
-				if (n == NULL) {
-					m_freem(m);
-					return NULL;
-				}
-				M_MOVE_PKTHDR(n, m);
-				n->m_len = MHLEN;
-			} else {
-				MGET(n, M_DONTWAIT, MT_DATA);
-				if (n == NULL) {
-					m_freem(m);
-					m_freem(n0);
-					return NULL;
-				}
-				n->m_len = MLEN;
-			}
-			if (pktlen - off >= MINCLSIZE) {
-				MCLGET(n, M_DONTWAIT);
-				if (n->m_flags & M_EXT)
-					n->m_len = n->m_ext.ext_size;
-			}
-			if (n0 == NULL) {
-				newdata =
-				    (caddr_t)ALIGN(n->m_data + sizeof(*eh)) -
-				    sizeof(*eh);
-				n->m_len -= newdata - n->m_data;
-				n->m_data = newdata;
-			}
-			if (n->m_len > pktlen - off)
-				n->m_len = pktlen - off;
-			m_copydata(m, off, n->m_len, mtod(n, caddr_t));
-			off += n->m_len;
-			*np = n;
-			np = &n->m_next;
-		}
-		m_freem(m);
-		m = n0;
+		m = ieee80211_realign(vap, m, sizeof(*eh));
+		if (m == NULL)
+			return NULL;
 	}
 #endif /* ALIGNED_POINTER */
 	if (llc != NULL) {
diff --git a/sys/net80211/ieee80211_input.h b/sys/net80211/ieee80211_input.h
index f19b934..5b38ddd 100644
--- a/sys/net80211/ieee80211_input.h
+++ b/sys/net80211/ieee80211_input.h
@@ -146,6 +146,7 @@ void	ieee80211_deliver_data(struct ieee80211vap *,
 		struct ieee80211_node *, struct mbuf *);
 struct mbuf *ieee80211_defrag(struct ieee80211_node *,
 		struct mbuf *, int);
+struct mbuf *ieee80211_realign(struct ieee80211vap *, struct mbuf *, size_t);
 struct mbuf *ieee80211_decap(struct ieee80211vap *, struct mbuf *, int);
 struct mbuf *ieee80211_decap1(struct mbuf *, int *);
 int	ieee80211_setup_rates(struct ieee80211_node *ni,
diff --git a/sys/net80211/ieee80211_ioctl.h b/sys/net80211/ieee80211_ioctl.h
index 723d3da..8105990 100644
--- a/sys/net80211/ieee80211_ioctl.h
+++ b/sys/net80211/ieee80211_ioctl.h
@@ -235,8 +235,9 @@ struct ieee80211_stats {
 	uint32_t	is_hwmp_wrongseq;	/* wrong hwmp seq no. */
 	uint32_t	is_hwmp_rootreqs;	/* root PREQs sent */
 	uint32_t	is_hwmp_rootrann;	/* root RANNs sent */
+	uint32_t	is_rx_badalign;		/* dropped 'cuz misaligned */
 
-	uint32_t	is_spare[16];
+	uint32_t	is_spare[15];
 };
 
 /*