- Use m_getcl() instead of hand allocating.

- Do not calculate constant length values at run time,
  CTASSERT() their sanity.
- Remove superfluous cleaning of mbuf fields after allocation.
- Replace compat macros with function calls.

Sponsored by:	Nginx, Inc.

4 files changed, 51 insertions, 104 deletions

diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index 089dabe..8772779 100644
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -578,25 +578,18 @@ icmp6_input(struct mbuf **mp, int *offp, int proto)
 		if ((n->m_flags & M_EXT) != 0
 		 || n->m_len < off + sizeof(struct icmp6_hdr)) {
 			struct mbuf *n0 = n;
-			const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 			int n0len;
 
+			CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 			n = m_gethdr(M_NOWAIT, n0->m_type);
-			n0len = n0->m_pkthdr.len;	/* save for use below */
-			if (n)
-				M_MOVE_PKTHDR(n, n0);	/* FIB copied. */
-			if (n && maxlen >= MHLEN) {
-				MCLGET(n, M_NOWAIT);
-				if ((n->m_flags & M_EXT) == 0) {
-					m_free(n);
-					n = NULL;
-				}
-			}
 			if (n == NULL) {
 				/* Give up remote */
 				m_freem(n0);
 				break;
 			}
+
+			m_move_pkthdr(n, n0);	/* FIB copied. */
+			n0len = n0->m_pkthdr.len;	/* save for use below */
 			/*
 			 * Copy IPv6 and ICMPv6 only.
 			 */
@@ -683,7 +676,7 @@ icmp6_input(struct mbuf **mp, int *offp, int proto)
 		} else {
 			struct prison *pr;
 			u_char *p;
-			int maxlen, maxhlen, hlen;
+			int maxhlen, hlen;
 
 			/*
 			 * XXX: this combination of flags is pointless,
@@ -694,20 +687,14 @@ icmp6_input(struct mbuf **mp, int *offp, int proto)
 
 			if (code != 0)
 				goto badcode;
-			maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
-			if (maxlen >= MCLBYTES) {
+
+			CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
+			n = m_gethdr(M_NOWAIT, m->m_type);
+			if (n == NULL) {
 				/* Give up remote */
 				break;
 			}
-			n = m_gethdr(M_NOWAIT, m->m_type);
-			if (n && maxlen > MHLEN) {
-				MCLGET(n, M_NOWAIT);
-				if ((n->m_flags & M_EXT) == 0) {
-					m_free(n);
-					n = NULL;
-				}
-			}
-			if (n && !m_dup_pkthdr(n, m, M_NOWAIT)) {
+			if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 				/*
 				 * Previous code did a blind M_COPY_PKTHDR
 				 * and said "just for rcvif".  If true, then
@@ -718,13 +705,8 @@ icmp6_input(struct mbuf **mp, int *offp, int proto)
 				m_free(n);
 				n = NULL;
 			}
-			if (n == NULL) {
-				/* Give up remote */
-				break;
-			}
-			n->m_pkthdr.rcvif = NULL;
-			n->m_len = 0;
-			maxhlen = M_TRAILINGSPACE(n) - maxlen;
+			maxhlen = M_TRAILINGSPACE(n) -
+			    (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 			pr = curthread->td_ucred->cr_prison;
 			mtx_lock(&pr->pr_mtx);
 			hlen = strlen(pr->pr_hostname);
@@ -1494,26 +1476,23 @@ ni6_input(struct mbuf *m, int off)
 		break;
 	}
 
-	/* allocate an mbuf to reply. */
-	n = m_gethdr(M_NOWAIT, m->m_type);
+	/* Allocate an mbuf to reply. */
+	if (replylen > MCLBYTES) {
+		/*
+		 * XXX: should we try to allocate more? But MCLBYTES
+		 * is probably much larger than IPV6_MMTU...
+		 */
+		goto bad;
+	}
+	if (replylen > MHLEN)
+		n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
+	else
+		n = m_gethdr(M_NOWAIT, m->m_type);
 	if (n == NULL) {
 		m_freem(m);
 		return (NULL);
 	}
-	M_MOVE_PKTHDR(n, m); /* just for recvif and FIB */
-	if (replylen > MHLEN) {
-		if (replylen > MCLBYTES) {
-			/*
-			 * XXX: should we try to allocate more? But MCLBYTES
-			 * is probably much larger than IPV6_MMTU...
-			 */
-			goto bad;
-		}
-		MCLGET(n, M_NOWAIT);
-		if ((n->m_flags & M_EXT) == 0) {
-			goto bad;
-		}
-	}
+	m_move_pkthdr(n, m); /* just for recvif and FIB */
 	n->m_pkthdr.len = n->m_len = replylen;
 
 	/* copy mbuf header and IPv6 + Node Information base headers */
diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
index 90a4f4e..e037737 100644
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -506,7 +506,7 @@ ip6_input(struct mbuf *m)
 			return;	/* ENOBUFS */
 		}
 
-		M_MOVE_PKTHDR(n, m);
+		m_move_pkthdr(n, m);
 		m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
 		n->m_len = n->m_pkthdr.len;
 		m_freem(m);
@@ -1662,22 +1662,12 @@ ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
 	else
 		elen = (ip6e.ip6e_len + 1) << 3;
 
-	MGET(n, M_NOWAIT, MT_DATA);
-	if (n && elen >= MLEN) {
-		MCLGET(n, M_NOWAIT);
-		if ((n->m_flags & M_EXT) == 0) {
-			m_free(n);
-			n = NULL;
-		}
-	}
-	if (!n)
-		return NULL;
-
-	n->m_len = 0;
-	if (elen >= M_TRAILINGSPACE(n)) {
-		m_free(n);
+	if (elen > MLEN)
+		n = m_getcl(M_NOWAIT, MT_DATA, 0);
+	else
+		n = m_get(M_NOWAIT, MT_DATA);
+	if (n == NULL)
 		return NULL;
-	}
 
 	m_copydata(m, off, elen, mtod(n, caddr_t));
 	n->m_len = elen;
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index cb1feab..e5042d2 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -1219,17 +1219,12 @@ ip6_copyexthdr(struct mbuf **mp, caddr_t hdr, int hlen)
 	if (hlen > MCLBYTES)
 		return (ENOBUFS); /* XXX */
 
-	MGET(m, M_NOWAIT, MT_DATA);
-	if (!m)
+	if (hlen > MLEN)
+		m = m_getcl(M_NOWAIT, MT_DATA, 0);
+	else
+		m = m_get(M_NOWAIT, MT_DATA);
+	if (m == NULL)
 		return (ENOBUFS);
-
-	if (hlen > MLEN) {
-		MCLGET(m, M_NOWAIT);
-		if ((m->m_flags & M_EXT) == 0) {
-			m_free(m);
-			return (ENOBUFS);
-		}
-	}
 	m->m_len = hlen;
 	if (hdr)
 		bcopy(hdr, mtod(m, caddr_t), hlen);
@@ -1257,8 +1252,8 @@ ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
 	 * Otherwise, use it to store the options.
 	 */
 	if (exthdrs->ip6e_hbh == 0) {
-		MGET(mopt, M_NOWAIT, MT_DATA);
-		if (mopt == 0)
+		mopt = m_get(M_NOWAIT, MT_DATA);
+		if (mopt == NULL)
 			return (ENOBUFS);
 		mopt->m_len = JUMBOOPTLEN;
 		optbuf = mtod(mopt, u_char *);
@@ -1289,15 +1284,8 @@ ip6_insert_jumboopt(struct ip6_exthdrs *exthdrs, u_int32_t plen)
 			 * As a consequence, we must always prepare a cluster
 			 * at this point.
 			 */
-			MGET(n, M_NOWAIT, MT_DATA);
-			if (n) {
-				MCLGET(n, M_NOWAIT);
-				if ((n->m_flags & M_EXT) == 0) {
-					m_freem(n);
-					n = NULL;
-				}
-			}
-			if (!n)
+			n = m_getcl(M_NOWAIT, MT_DATA, 0);
+			if (n == NULL)
 				return (ENOBUFS);
 			n->m_len = oldoptlen + JUMBOOPTLEN;
 			bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
@@ -1366,8 +1354,8 @@ ip6_insertfraghdr(struct mbuf *m0, struct mbuf *m, int hlen,
 		/* allocate a new mbuf for the fragment header */
 		struct mbuf *mfrg;
 
-		MGET(mfrg, M_NOWAIT, MT_DATA);
-		if (mfrg == 0)
+		mfrg = m_get(M_NOWAIT, MT_DATA);
+		if (mfrg == NULL)
 			return (ENOBUFS);
 		mfrg->m_len = sizeof(struct ip6_frag);
 		*frghdrp = mtod(mfrg, struct ip6_frag *);
@@ -3047,7 +3035,7 @@ ip6_splithdr(struct mbuf *m, struct ip6_exthdrs *exthdrs)
 			m_freem(m);
 			return ENOBUFS;
 		}
-		M_MOVE_PKTHDR(mh, m);
+		m_move_pkthdr(mh, m);
 		MH_ALIGN(mh, sizeof(*ip6));
 		m->m_len -= sizeof(*ip6);
 		m->m_data += sizeof(*ip6);
diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c
index 7fe75bf..532c9b8 100644
--- a/sys/netinet6/nd6_nbr.c
+++ b/sys/netinet6/nd6_nbr.c
@@ -419,17 +419,12 @@ nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6,
 		return;
 	}
 
-	MGETHDR(m, M_NOWAIT, MT_DATA);
-	if (m && max_linkhdr + maxlen >= MHLEN) {
-		MCLGET(m, M_NOWAIT);
-		if ((m->m_flags & M_EXT) == 0) {
-			m_free(m);
-			m = NULL;
-		}
-	}
+	if (max_linkhdr + maxlen > MHLEN)
+		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
+	else
+		m = m_gethdr(M_NOWAIT, MT_DATA);
 	if (m == NULL)
 		return;
-	m->m_pkthdr.rcvif = NULL;
 
 	bzero(&ro, sizeof(ro));
 
@@ -997,17 +992,12 @@ nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
 		return;
 	}
 
-	MGETHDR(m, M_NOWAIT, MT_DATA);
-	if (m && max_linkhdr + maxlen >= MHLEN) {
-		MCLGET(m, M_NOWAIT);
-		if ((m->m_flags & M_EXT) == 0) {
-			m_free(m);
-			m = NULL;
-		}
-	}
+	if (max_linkhdr + maxlen > MHLEN)
+		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
+	else
+		m = m_gethdr(M_NOWAIT, MT_DATA);
 	if (m == NULL)
 		return;
-	m->m_pkthdr.rcvif = NULL;
 	M_SETFIB(m, fibnum);
 
 	if (IN6_IS_ADDR_MULTICAST(&daddr6)) {