Always defer output TCP checksumming until ip_output() (or hardware,

if it exists). Cuts down on code a bit, and we don't need to look at
the routing entry at TCP. Based on NetBSD. UDP case to follow.

3 files changed, 35 insertions, 59 deletions

diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c
index cefbdded6f6..2e548f4552a 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_output.c,v 1.120 2001/06/25 01:21:15 provos Exp $	*/
+/*	$OpenBSD: ip_output.c,v 1.121 2001/06/25 01:59:29 angelos Exp $	*/
 /*	$NetBSD: ip_output.c,v 1.28 1996/02/13 23:43:07 christos Exp $	*/
 
 /*
@@ -64,6 +64,9 @@
 #include <netinet/ip_icmp.h>
 #include <netinet/tcp.h>
 #include <netinet/udp.h>
+#include <netinet/tcp_timer.h>
+#include <netinet/tcp_var.h>
+#include <netinet/udp_var.h>
 
 #ifdef vax
 #include <machine/mtpr.h>
@@ -670,16 +673,18 @@ sendit:
 	}
 #endif
 	/* Catch routing changes wrt. hardware checksumming for TCP or UDP. */
-	if (m->m_pkthdr.csum & M_TCPV4_CSUM_OUT &&
-	    !(ifp->if_capabilities & IFCAP_CSUM_TCPv4)) {
-		in_delayed_cksum(m);
-		m->m_pkthdr.csum &= ~M_TCPV4_CSUM_OUT; /* Clear */
-	}
-
-	if (m->m_pkthdr.csum & M_UDPV4_CSUM_OUT &&
-	    !(ifp->if_capabilities & IFCAP_CSUM_UDPv4)) {
-		in_delayed_cksum(m);
-		m->m_pkthdr.csum &= ~M_UDPV4_CSUM_OUT; /* Clear */
+	if (m->m_pkthdr.csum & M_TCPV4_CSUM_OUT) {
+		if (!(ifp->if_capabilities & IFCAP_CSUM_TCPv4) ||
+		    ifp->if_bridge != NULL) {
+			in_delayed_cksum(m);
+			m->m_pkthdr.csum &= ~M_TCPV4_CSUM_OUT; /* Clear */
+		}
+	} else if (m->m_pkthdr.csum & M_UDPV4_CSUM_OUT) {
+		if (!(ifp->if_capabilities & IFCAP_CSUM_UDPv4) ||
+		    ifp->if_bridge != NULL) {
+			in_delayed_cksum(m);
+			m->m_pkthdr.csum &= ~M_UDPV4_CSUM_OUT; /* Clear */
+		}
 	}
 
 	/*
@@ -696,6 +701,11 @@ sendit:
 			ip->ip_sum = 0;
 			ip->ip_sum = in_cksum(m, hlen);
 		}
+		/* Update relevant hardware checksum stats for TCP/UDP */
+		if (m->m_pkthdr.csum & M_TCPV4_CSUM_OUT)
+			tcpstat.tcps_outhwcsum++;
+		else if (m->m_pkthdr.csum & M_UDPV4_CSUM_OUT)
+			udpstat.udps_outhwcsum++;
 		error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt);
 		goto done;
 	}
@@ -1857,7 +1867,7 @@ in_delayed_cksum(struct mbuf *m)
 
 	ip = mtod(m, struct ip *);
 	offset = ip->ip_hl << 2;
-	csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset);
+	csum = in4_cksum(m, 0, offset, m->m_pkthdr.len - offset);
 	if (csum == 0 && ip->ip_p == IPPROTO_UDP)
 		csum = 0xffff;
 
diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index 0fac61efd0a..d7587bc52e6 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_output.c,v 1.42 2001/06/25 00:11:58 angelos Exp $	*/
+/*	$OpenBSD: tcp_output.c,v 1.43 2001/06/25 01:59:29 angelos Exp $	*/
 /*	$NetBSD: tcp_output.c,v 1.16 1997/06/03 16:17:09 kml Exp $	*/
 
 /*
@@ -226,8 +226,6 @@ tcp_output(tp)
 	u_char opt[MAX_TCPOPTLEN];
 	unsigned int optlen, hdrlen;
 	int idle, sendalot = 0;
-	struct route *ro;
-	struct ifnet *ifp;
 #ifdef TCP_SACK
 	int i, sack_rxmit = 0;
 	struct sackhole *p;
@@ -846,22 +844,6 @@ send:
 		 */
 		tp->snd_up = tp->snd_una;		/* drag it along */
 
-	/* Put TCP length in pseudo-header */
-	switch (tp->pf) {
-	case 0:	/*default to PF_INET*/
-#ifdef INET
-	case AF_INET:
-		if (len + optlen)
-			mtod(m, struct ipovly *)->ih_len = htons((u_int16_t)(
-				sizeof (struct tcphdr) + optlen + len));
-		break;
-#endif /* INET */
-#ifdef INET6
-	case AF_INET6:
-		break;
-#endif /* INET6 */
-	}
-
 #ifdef TCP_SIGNATURE
 	if (tp->t_flags & TF_SIGNATURE) {
 		MD5_CTX ctx;
@@ -910,7 +892,8 @@ send:
 				ippseudo.ippseudo_dst = ipovly->ih_dst;
 				ippseudo.ippseudo_pad = 0;
 				ippseudo.ippseudo_p   = IPPROTO_TCP;
-				ippseudo.ippseudo_len = ipovly->ih_len;
+				ippseudo.ippseudo_len = ipovly->ih_len + len +
+				    optlen;
 				MD5Update(&ctx, (char *)&ippseudo,
 					sizeof(struct ippseudo));
 				MD5Update(&ctx, mtod(m, caddr_t) +
@@ -951,29 +934,11 @@ send:
 	case 0:	/*default to PF_INET*/
 #ifdef INET
 	case AF_INET:
-		/*
-		 * If we know our route, and the interface supports TCPv4
-		 * checksumming, only compute the pseudoheader.
-		 */
-		ro = &tp->t_inpcb->inp_route;
-		if (ro->ro_rt && (ro->ro_rt->rt_flags & RTF_UP)) {
-			ifp = ro->ro_rt->rt_ifp;
-			if ((ifp->if_capabilities & IFCAP_CSUM_TCPv4) &&
-			    ifp->if_bridge == NULL) {
-				struct ipovly *ipov;
-
-				ipov = mtod(m, struct ipovly *);
-				m->m_pkthdr.csum |= M_TCPV4_CSUM_OUT;
-				tcpstat.tcps_outhwcsum++;
-				th->th_sum = in_cksum_phdr(ipov->ih_src.s_addr,
-				    ipov->ih_dst.s_addr,
-				    htons(sizeof(struct tcphdr) + len +
-					optlen + IPPROTO_TCP));
-				break;
-			}
-		}
-
-		th->th_sum = in_cksum(m, (int)(hdrlen + len));
+		/* Defer checksumming until later (ip_output() or hardware) */
+		m->m_pkthdr.csum |= M_TCPV4_CSUM_OUT;
+		if (len + optlen)
+			th->th_sum = in_cksum_addword(th->th_sum,
+			    htons((u_int16_t)(len + optlen)));
 		break;
 #endif /* INET */
 #ifdef INET6
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 38f4243d42d..50a1e1aaa1c 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_subr.c,v 1.47 2001/06/23 19:02:53 angelos Exp $	*/
+/*	$OpenBSD: tcp_subr.c,v 1.48 2001/06/25 01:59:29 angelos Exp $	*/
 /*	$NetBSD: tcp_subr.c,v 1.22 1996/02/13 23:44:00 christos Exp $	*/
 
 /*
@@ -235,13 +235,15 @@ tcp_template(tp)
 
 			bzero(ipovly->ih_x1, sizeof ipovly->ih_x1);
 			ipovly->ih_pr = IPPROTO_TCP;
-			ipovly->ih_len = htons(sizeof (struct tcpiphdr) -
-				sizeof (struct ip));
+			ipovly->ih_len = htons(sizeof (struct tcphdr));
 			ipovly->ih_src = inp->inp_laddr;
 			ipovly->ih_dst = inp->inp_faddr;
 
 			th = (struct tcphdr *)(mtod(m, caddr_t) +
 				sizeof(struct ip));
+			th->th_sum = in_cksum_phdr(ipovly->ih_src.s_addr,
+			    ipovly->ih_dst.s_addr,
+			    htons(sizeof (struct tcphdr) + IPPROTO_TCP));
 		}
 		break;
 #endif /* INET */
@@ -277,7 +279,6 @@ tcp_template(tp)
 	th->th_off = 5;
 	th->th_flags = 0;
 	th->th_win = 0;
-	th->th_sum = 0;
 	th->th_urp = 0;
 	return (m);
 }