Make it possible to use IP_TTL and IP_TOS setsockopt(2) options

on certain types of SOCK_RAW sockets.  Also, use the ip.ttl MIB
variable instead of MAXTTL constant as the default time-to-live
value for outgoing IP packets all over the place, as we already
do this for TCP and UDP.

Reviewed by:	wollman

share/man/man4/ip.4

@@ -32,9 +32,9 @@
 .\"     @(#)ip.4	8.2 (Berkeley) 11/30/93
 .\" $FreeBSD$
 .\"
-.Dd November 30, 1993
+.Dd March 3, 2001
 .Dt IP 4
-.Os BSD 4.2
+.Os
 .Sh NAME
 .Nm ip
 .Nd Internet Protocol
@@ -100,9 +100,9 @@ may be used to set the type-of-service and time-to-live
 fields in the 
 .Tn IP 
 header for 
-.Dv SOCK_STREAM 
-and 
-.Dv SOCK_DGRAM 
+.Dv SOCK_STREAM , SOCK_DGRAM ,
+and certain types of
+.Dv SOCK_RAW
 sockets.
 For example,
 .Bd -literal
@@ -355,7 +355,7 @@ setsockopt(s, IPPROTO_IP, IP_HDRINCL, &hincl, sizeof(hincl));
 .Ed
 .Pp
 Unlike previous 
-.Tn BSD 
+.Bx 
 releases, the program must set all
 the fields of the IP header, including the following:
 .Bd -literal

sys/netinet/ip_icmp.c

@@ -638,7 +638,7 @@ icmp_reflect(m)
 		ia = TAILQ_FIRST(&in_ifaddrhead);
 	t = IA_SIN(ia)->sin_addr;
 	ip->ip_src = t;
-	ip->ip_ttl = MAXTTL;
+	ip->ip_ttl = ip_defttl;
 
 	if (optlen > 0) {
 		register u_char *cp;

sys/netinet/raw_ip.c

@@ -197,13 +197,13 @@ rip_output(m, so, dst)
 		}
 		M_PREPEND(m, sizeof(struct ip), M_TRYWAIT);
 		ip = mtod(m, struct ip *);
-		ip->ip_tos = 0;
+		ip->ip_tos = inp->inp_ip_tos;
 		ip->ip_off = 0;
 		ip->ip_p = inp->inp_ip_p;
 		ip->ip_len = m->m_pkthdr.len;
 		ip->ip_src = inp->inp_laddr;
 		ip->ip_dst.s_addr = dst;
-		ip->ip_ttl = MAXTTL;
+		ip->ip_ttl = inp->inp_ip_ttl;
 	} else {
 		if (m->m_pkthdr.len > IP_MAXPACKET) {
 			m_freem(m);
@@ -458,6 +458,7 @@ rip_attach(struct socket *so, int proto, struct proc *p)
 	inp = (struct inpcb *)so->so_pcb;
 	inp->inp_vflag |= INP_IPV4;
 	inp->inp_ip_p = proto;
+	inp->inp_ip_ttl = ip_defttl;
 #ifdef IPSEC
 	error = ipsec_init_policy(so, &inp->inp_sp);
 	if (error != 0) {