X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/8a13b73762073376faf12d2b8b2d763eeb7def70..4f483d7dc3ca3e5a8ac5145cdc54a67819dea48e:/usr/src/sys/netinet/ip_input.c

diff --git a/usr/src/sys/netinet/ip_input.c b/usr/src/sys/netinet/ip_input.c
index 014e589cbd..04fc07c13f 100644
--- a/usr/src/sys/netinet/ip_input.c
+++ b/usr/src/sys/netinet/ip_input.c
@@ -1,4 +1,4 @@
-/* ip_input.c 1.19 81/11/26 */
+/*	ip_input.c	1.38	82/03/31	*/
 
 #include "../h/param.h"
 #include "../h/systm.h"
@@ -15,9 +15,12 @@
 #include "../net/tcp.h"
 
 u_char	ip_protox[IPPROTO_MAX];
+int	ipqmaxlen = IFQ_MAXLEN;
+struct	ifnet *ifinet;			/* first inet interface */
 
 /*
- * Ip initialization.
+ * IP initialization: fill in IP protocol switch table.
+ * All protocols not implemented in kernel go to raw IP protocol handler.
  */
 ip_init()
 {
@@ -36,14 +39,15 @@ COUNT(IP_INIT);
 			ip_protox[pr->pr_protocol] = pr - protosw;
 	ipq.next = ipq.prev = &ipq;
 	ip_id = time & 0xffff;
+	ipintrq.ifq_maxlen = ipqmaxlen;
+	ifinet = if_ifwithaf(AF_INET);
 }
 
 u_char	ipcksum = 1;
 struct	ip *ip_reass();
-
-/*
- * Ip input routines.
- */
+int	ipforwarding = 1;
+int	ipprintfs = 0;
+struct	sockaddr_in ipaddr = { AF_INET };
 
 /*
  * Ip input routine.  Checksum and byte swap header.  If fragmented
@@ -54,7 +58,7 @@ ipintr()
 {
 	register struct ip *ip;
 	register struct mbuf *m;
-	struct mbuf *m0;
+	struct mbuf *m0, *mopt;
 	register int i;
 	register struct ipq *fp;
 	int hlen, s;
@@ -70,26 +74,30 @@ next:
 	splx(s);
 	if (m == 0)
 		return;
-	if (m->m_len < sizeof (struct ip) &&
-	    m_pullup(m, sizeof (struct ip)) == 0)
-		goto bad;
+	if ((m->m_off > MMAXOFF || m->m_len < sizeof (struct ip)) &&
+	    (m = m_pullup(m, sizeof (struct ip))) == 0)
+		return;
 	ip = mtod(m, struct ip *);
-	if ((hlen = ip->ip_hl << 2) > m->m_len &&
-	    m_pullup(m, hlen) == 0)
-		goto bad;
+	if ((hlen = ip->ip_hl << 2) > m->m_len) {
+		if ((m = m_pullup(m, hlen)) == 0)
+			return;
+		ip = mtod(m, struct ip *);
+	}
 	if (ipcksum)
-		if ((ip->ip_sum = in_cksum(m, hlen)) != 0xffff) {
-			printf("ip_sum %x\n", ip->ip_sum);
+		if (ip->ip_sum = in_cksum(m, hlen)) {
+			printf("ip_sum %x\n", ip->ip_sum);	/* XXX */
 			ipstat.ips_badsum++;
 			goto bad;
 		}
 
+#if vax
 	/*
 	 * Convert fields to host representation.
 	 */
 	ip->ip_len = ntohs((u_short)ip->ip_len);
 	ip->ip_id = ntohs(ip->ip_id);
 	ip->ip_off = ntohs((u_short)ip->ip_off);
+#endif
 
 	/*
 	 * Check that the amount of data in the buffers
@@ -98,12 +106,17 @@ next:
 	 * Drop packet if shorter than we expect.
 	 */
 	i = 0;
-	for (m0 = m; m != NULL; m = m->m_next)
+	m0 = m;
+	for (; m != NULL; m = m->m_next) {
+		if (m->m_free) panic("ipinput already free");
 		i += m->m_len;
+	}
 	m = m0;
 	if (i != ip->ip_len) {
-		if (i < ip->ip_len)
+		if (i < ip->ip_len) {
+			ipstat.ips_tooshort++;
 			goto bad;
+		}
 		m_adj(m, ip->ip_len - i);
 	}
 
@@ -113,16 +126,44 @@ next:
 	 */
 	if (hlen > sizeof (struct ip))
 		ip_dooptions(ip);
-	if (ifnet && ip->ip_dst.s_addr != ifnet->if_addr.s_addr &&
-	    if_ifwithaddr(ip->ip_dst) == 0) {
-		if (--ip->ip_ttl == 0) {
+
+	/*
+	 * Fast check on the first internet
+	 * interface in the list.
+	 */
+	if (ifinet) {
+		struct sockaddr_in *sin;
+
+		sin = (struct sockaddr_in *)&ifinet->if_addr;
+		if (sin->sin_addr.s_addr == ip->ip_dst.s_addr)
+			goto ours;
+		if ((ifinet->if_flags & IFF_BROADCAST) &&
+		    sin->sin_addr.s_addr == ip->ip_dst.s_addr)
+			goto ours;
+	}
+	ipaddr.sin_addr = ip->ip_dst;
+	if (if_ifwithaddr((struct sockaddr *)&ipaddr) == 0) {
+		if (ipprintfs)
+			printf("forward: src %x dst %x ttl %x\n", ip->ip_src,
+				ip->ip_dst, ip->ip_ttl);
+		if (ipforwarding == 0)
+			goto bad;
+		if (ip->ip_ttl < IPTTLDEC) {
 			icmp_error(ip, ICMP_TIMXCEED, 0);
 			goto next;
 		}
-		ip_output(dtom(ip), (struct mbuf *)0);
+		ip->ip_ttl -= IPTTLDEC;
+		mopt = m_get(M_DONTWAIT);
+		if (mopt == 0)
+			goto bad;
+		ip_stripoptions(ip, mopt);
+
+		/* last 0 here means no directed broadcast */
+		(void) ip_output(m0, mopt, 0, 0);
 		goto next;
 	}
 
+ours:
 	/*
 	 * Look for queue of fragments
 	 * of this datagram.
@@ -201,7 +242,7 @@ COUNT(IP_REASS);
 	 * If first fragment to arrive, create a reassembly queue.
 	 */
 	if (fp == 0) {
-		if ((t = m_get(1)) == NULL)
+		if ((t = m_get(M_WAIT)) == NULL)
 			goto dropfrag;
 		t->m_off = MMINOFF;
 		fp = mtod(t, struct ipq *);
@@ -212,6 +253,8 @@ COUNT(IP_REASS);
 		fp->ipq_next = fp->ipq_prev = (struct ipasfrag *)fp;
 		fp->ipq_src = ((struct ip *)ip)->ip_src;
 		fp->ipq_dst = ((struct ip *)ip)->ip_dst;
+		q = (struct ipasfrag *)fp;
+		goto insert;
 	}
 
 	/*
@@ -245,6 +288,7 @@ COUNT(IP_REASS);
 		i = (ip->ip_off + ip->ip_len) - q->ip_off;
 		if (i < q->ip_len) {
 			q->ip_len -= i;
+			q->ip_off += i;
 			m_adj(dtom(q), i);
 			break;
 		}
@@ -253,6 +297,7 @@ COUNT(IP_REASS);
 		ip_deq(q->ipf_prev);
 	}
 
+insert:
 	/*
 	 * Stick new segment in its place;
 	 * check for complete reassembly.
@@ -275,8 +320,12 @@ COUNT(IP_REASS);
 	t = m->m_next;
 	m->m_next = 0;
 	m_cat(m, t);
-	while ((q = q->ipf_next) != (struct ipasfrag *)fp)
-		m_cat(m, dtom(q));
+	q = q->ipf_next;
+	while (q != (struct ipasfrag *)fp) {
+		t = dtom(q);
+		q = q->ipf_next;
+		m_cat(m, t);
+	}
 
 	/*
 	 * Create header for new ip packet by
@@ -359,7 +408,12 @@ ip_slowtimo()
 	int s = splnet();
 
 COUNT(IP_SLOWTIMO);
-	for (fp = ipq.next; fp != &ipq; )
+	fp = ipq.next;
+	if (fp == 0) {
+		splx(s);
+		return;
+	}
+	while (fp != &ipq)
 		if (--fp->ipq_ttl == 0)
 			fp = ip_freef(fp);
 		else
@@ -422,7 +476,8 @@ COUNT(IP_DOOPTIONS);
 			if (cp[2] < 4 || cp[2] > optlen - (sizeof (long) - 1))
 				break;
 			sin = (struct in_addr *)(cp + cp[2]);
-			ifp = if_ifwithaddr(*sin);
+			ipaddr.sin_addr = *sin;
+			ifp = if_ifwithaddr((struct sockaddr *)&ipaddr);
 			if (ifp == 0) {
 				if (opt == IPOPT_SSRR)
 					goto bad;
@@ -433,7 +488,8 @@ COUNT(IP_DOOPTIONS);
 			if (cp[2] > optlen - (sizeof (long) - 1))
 				break;
 			ip->ip_dst = sin[1];
-			if (opt == IPOPT_SSRR && if_ifonnetof(ip->ip_dst)==0)
+			if (opt == IPOPT_SSRR &&
+			    if_ifonnetof(ip->ip_dst.s_net) == 0)
 				goto bad;
 			break;
 
@@ -455,12 +511,14 @@ COUNT(IP_DOOPTIONS);
 			case IPOPT_TS_TSANDADDR:
 				if (ipt->ipt_ptr + 8 > ipt->ipt_len)
 					goto bad;
-				/* stamp with ``first'' interface address */
-				*sin++ = ifnet->if_addr;
+				if (ifinet == 0)
+					goto bad;	/* ??? */
+				*sin++ = ((struct sockaddr_in *)&ifinet->if_addr)->sin_addr;
 				break;
 
 			case IPOPT_TS_PRESPEC:
-				if (if_ifwithaddr(*sin) == 0)
+				ipaddr.sin_addr = *sin;
+				if (if_ifwithaddr((struct sockaddr *)&ipaddr) == 0)
 					continue;
 				if (ipt->ipt_ptr + 8 > ipt->ipt_len)
 					goto bad;
@@ -486,9 +544,9 @@ bad:
  * Second argument is buffer to which options
  * will be moved, and return value is their length.
  */
-ip_stripoptions(ip, cp)
+ip_stripoptions(ip, mopt)
 	struct ip *ip;
-	char *cp;
+	struct mbuf *mopt;
 {
 	register int i;
 	register struct mbuf *m;
@@ -498,9 +556,12 @@ COUNT(IP_STRIPOPTIONS);
 	olen = (ip->ip_hl<<2) - sizeof (struct ip);
 	m = dtom(ip);
 	ip++;
-	if (cp)
-		bcopy((caddr_t)ip, cp, (unsigned)olen);
+	if (mopt) {
+		mopt->m_len = olen;
+		mopt->m_off = MMINOFF;
+		bcopy((caddr_t)ip, mtod(m, caddr_t), (unsigned)olen);
+	}
 	i = m->m_len - (sizeof (struct ip) + olen);
 	bcopy((caddr_t)ip+olen, (caddr_t)ip, (unsigned)i);
-	m->m_len -= i;
+	m->m_len -= olen;
 }