libip: Provide iplocalonifc() and ipremoteonifc() functions

These functions are analog to devip's functions
of the same name.

This is mainly to maintain consistent naming...

sys/include/ip.h

@@ -171,6 +171,8 @@ int	equivip4(uchar*, uchar*);
 int	equivip6(uchar*, uchar*);
 
 Ipifc*	readipifc(char*, Ipifc*, int);
+Iplifc*	iplocalonifc(Ipifc *, uchar *);
+Iplifc*	ipremoteonifc(Ipifc *, uchar *);
 
 void	hnputv(void*, uvlong);
 void	hnputl(void*, uint);

sys/man/2/ip

@@ -1,6 +1,6 @@
 .TH IP 2
 .SH NAME
-eipfmt, parseip, parseipmask, parseipandmask, v4parseip, parseether, myipaddr, myetheraddr, maskip, equivip4, equivip6, defmask, isv4, v4tov6, v6tov4, nhgetv, nhgetl, nhgets, hnputv, hnputl, hnputs, ptclbsum, readipifc \- Internet Protocol addressing
+eipfmt, parseip, parseipmask, parseipandmask, v4parseip, parseether, myipaddr, myetheraddr, maskip, equivip4, equivip6, defmask, isv4, v4tov6, v6tov4, nhgetv, nhgetl, nhgets, hnputv, hnputl, hnputs, ptclbsum, readipifc, iplocalonifc, ipremoteonifc \- Internet Protocol addressing
 .SH SYNOPSIS
 .B #include <u.h>
 .br
@@ -78,6 +78,12 @@ ushort	ptclbsum(uchar *a, int n)
 Ipifc*	readipifc(char *net, Ipifc *ifc, int index)
 .PP
 .B
+Iplifc*	iplocalonifc(Ipifc *ifc, uchar *ip)
+.PP
+.B
+Iplifc*	ipremoteonifc(Ipifc *ifc, uchar *ip)
+.PP
+.B
 uchar	IPv4bcast[IPaddrlen];
 .PP
 .B
@@ -372,6 +378,33 @@ is
 if the network is multipoint or
 the remote address if the network is
 point to point.
+.PP
+.I Iplocalonifc
+looks up the first local address structure
+that matches
+.I ip
+on the interface
+.IR ifc .
+E.g.
+.I ip
+is one of our local ip addresses on
+.IR ifc .
+.I Ipremoteonifc
+returns the first local address structure
+with a subnet that
+.I ip
+is a member of.
+E.g.
+.I ip
+is a directly reachable remote address on
+.IR ifc .
+Both
+.I iplocalonifc
+and
+.I ipremoteonifc
+return
+.B nil
+when no local address structrue is found.
 .SH SOURCE
 .B /sys/src/libip
 .SH SEE ALSO

sys/src/cmd/auth/secureidcheck.c

@@ -325,22 +325,6 @@ logPacket(Packet *p)
 	syslog(0, AUTHLOG, "%s", pbuf);
 }
 
-static uchar*
-getipv4addr(void)
-{
-	Ipifc *nifc;
-	Iplifc *lifc;
-	static Ipifc *ifc;
-
-	ifc = readipifc("/net", ifc, -1);
-	for(nifc = ifc; nifc; nifc = nifc->next)
-		for(lifc = nifc->lifc; lifc; lifc = lifc->next)
-			if (ipcmp(lifc->ip, IPnoaddr) != 0 &&
-			    ipcmp(lifc->ip, v4prefix) != 0)
-				return lifc->ip;
-	return nil;
-}
-
 extern Ndb *db;
 
 /* returns 0 on success, error message on failure */
@@ -350,7 +334,7 @@ secureidcheck(char *user, char *response)
 	char *radiussecret = nil;
 	char *rv = "authentication failed";
 	char dest[3*IPaddrlen+20], ruser[64];
-	uchar *ip;
+	uchar ip[IPaddrlen];
 	uchar x[16];
 	ulong u[4];
 	Ndbs s;
@@ -394,11 +378,14 @@ secureidcheck(char *user, char *response)
 		goto out;
 	shared.s = (uchar*)radiussecret;
 	shared.len = strlen(radiussecret);
-	ip = getipv4addr();
-	if(ip == nil){
+	if(myipaddr(ip, "/net") < 0){
 		syslog(0, AUTHLOG, "no interfaces: %r");
 		goto out;
 	}
+	if(!isv4(ip)){
+		syslog(0, AUTHLOG, "no ipv4 address");
+		goto out;
+	}
 	if(setAttribute(req, R_NASIPAddress, ip + IPv4off, 4) < 0)
 		goto out;
 

sys/src/cmd/ip/dhcp6d.c

@@ -103,29 +103,12 @@ static Ipifc*
 findifc(char *net, uchar ip[IPaddrlen])
 {
 	Ipifc *ifc;
-	Iplifc *lifc;
 
 	ipifcs = readipifc(net, ipifcs, -1);
-	for(ifc = ipifcs; ifc != nil; ifc = ifc->next)
-		for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next)
-			if(ipcmp(lifc->ip, ip) == 0)
-				return ifc;
-
-	return nil;
-}
-
-static Iplifc*
-localonifc(Ipifc *ifc, uchar ip[IPaddrlen])
-{
-	Iplifc *lifc;
-	uchar net[IPaddrlen];
-
-	for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next){
-		maskip(ip, lifc->mask, net);
-		if(ipcmp(net, lifc->net) == 0)
-			return lifc;
+	for(ifc = ipifcs; ifc != nil; ifc = ifc->next){
+		if(iplocalonifc(ifc, ip) != nil)
+			return ifc;
 	}
-
 	return nil;
 }
 
@@ -364,8 +347,7 @@ main(int argc, char *argv[])
 			continue;
 		if((r->ifc = findifc(netmtpt, r->udp->ifcaddr)) == nil)
 			continue;
-		lifc = localonifc(r->ifc, r->udp->raddr);
-		if(lifc == nil)
+		if((lifc = ipremoteonifc(r->ifc, r->udp->raddr)) == nil)
 			continue;
 
 		memmove(obuf, ibuf, Udphdrsize);

sys/src/cmd/ip/dhcpd/dat.h

@@ -73,7 +73,6 @@ extern int	lookup(Bootp*, Info*, Info*);
 extern int	lookupip(uchar*, char*, char*, Info*, int);
 extern void	lookupname(char*, int, Ndbtuple*);
 extern Ipifc*	findifc(uchar*);
-extern Iplifc*	localonifc(uchar*, Ipifc*);
 extern void	localip(uchar*, uchar*, Ipifc*);
 extern int	lookupserver(char*, uchar**, int, Ndbtuple *t);
 extern Ndbtuple* lookupinfo(uchar *ipaddr, char **attr, int n);

sys/src/cmd/ip/dhcpd/db.c

@@ -177,23 +177,15 @@ syncbinding(Binding *b, int returnfd)
 extern int
 samenet(uchar *ip, Info *iip)
 {
-	uchar x[IPaddrlen];
+	uchar net[IPaddrlen];
 
 	/* directly connected, check local networks */
-	if(iip->ifc != nil){
-		Iplifc *lifc;
-
-		for(lifc = iip->ifc->lifc; lifc != nil; lifc = lifc->next){
-			maskip(lifc->mask, ip, x);
-			if(ipcmp(x, lifc->net) == 0)
-				return 1;
-		}
-		return 0;
-	}
+	if(iip->ifc != nil)
+		return ipremoteonifc(iip->ifc, ip) != nil;
 
 	/* relay agent, check upstream network */
-	maskip(iip->ipmask, ip, x);
-	return ipcmp(x, iip->ipnet) == 0;
+	maskip(ip, iip->ipmask, net);
+	return ipcmp(net, iip->ipnet) == 0;
 }
 
 /*

sys/src/cmd/ip/dhcpd/dhcpd.c

@@ -350,7 +350,8 @@ proto(Req *rp, int n)
 		rp->gii.ifc = nil;
 	} else {
 		/* no gateway, directly connected */
-		if(ipcmp(rp->up->laddr, IPv4bcast) != 0 && localonifc(rp->up->laddr, rp->ifc) == nil){
+		if(ipcmp(rp->up->laddr, IPv4bcast) != 0
+		&& ipremoteonifc(rp->ifc, rp->up->laddr) == nil){
 			warning("wrong network %I->%I on %s",
 				rp->up->raddr, rp->up->laddr, rp->ifc->dev);
 			return;
@@ -1135,7 +1136,7 @@ miscoptions(Req *rp, uchar *ip)
 		maskopt(rp, OBmask, rp->ii.ipmask);
 	else if(validip(rp->gii.ipmask))
 		maskopt(rp, OBmask, rp->gii.ipmask);
-	else if((lifc = localonifc(ip, rp->ifc)) != nil)
+	else if((lifc = ipremoteonifc(rp->ifc, ip)) != nil)
 		maskopt(rp, OBmask, lifc->mask);
 
 	if(validip(rp->ii.gwip)){

sys/src/cmd/ip/dhcpd/ndb.c

@@ -37,29 +37,10 @@ Ipifc*
 findifc(uchar *ip)
 {
 	Ipifc *ifc;
-	Iplifc *lifc;
 
 	for(ifc = ipifcs; ifc != nil; ifc = ifc->next){
-		for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next)
-			if(ipcmp(ip, lifc->ip) == 0)
-				return ifc;
-	}
-	return nil;
-}
-
-Iplifc*
-localonifc(uchar *ip, Ipifc *ifc)
-{
-	uchar x[IPaddrlen];
-	Iplifc *lifc;
-
-	if(ifc == nil)
-		return nil;
-
-	for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next){
-		maskip(ip, lifc->mask, x);
-		if(ipcmp(x, lifc->net) == 0)
-			return lifc;
+		if(iplocalonifc(ifc, ip) != nil)
+			return ifc;
 	}
 	return nil;
 }
@@ -69,13 +50,12 @@ localip(uchar *laddr, uchar *raddr, Ipifc *ifc)
 {
 	Iplifc *lifc;
 
-	if((lifc = localonifc(raddr, ifc)) != nil)
+	if((lifc = ipremoteonifc(ifc, raddr)) != nil)
 		ipmove(laddr, lifc->ip);
 	else if(ipcmp(laddr, IPv4bcast) == 0)
 		ipmove(laddr, IPnoaddr);
 }
 
-
 static void
 setipaddr(uchar *addr, char *ip)
 {

sys/src/cmd/ip/ipconfig/main.c

@@ -297,15 +297,10 @@ findmyifc(void)
 int
 myip(Ipifc *ifc, uchar *ip)
 {
-	Iplifc *lifc;
-
 	for(; ifc != nil; ifc = ifc->next) {
-		for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next){
-			if(ipcmp(ip, lifc->ip) == 0)
-				return 1;
-		}
+		if(iplocalonifc(ifc, ip) != nil)
+			return 1;
 	}
-
 	return 0;
 }
 

sys/src/cmd/ndb/dblookup.c

@@ -900,15 +900,12 @@ int
 myip(uchar *ip)
 {
 	Ipifc *ifc;
-	Iplifc *lifc;
 
 	qlock(&ipifclock);
 	for(ifc = ipifcs; ifc != nil; ifc = ifc->next){
-		for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next){
-			if(ipcmp(ip, lifc->ip) == 0){
-				qunlock(&ipifclock);
-				return 1;
-			}
+		if(iplocalonifc(ifc, ip) != nil){
+			qunlock(&ipifclock);
+			return 1;
 		}
 	}
 	qunlock(&ipifclock);

sys/src/libip/mkfile

@@ -12,6 +12,8 @@ OFILES=\
 	bo.$O\
 	readipifc.$O\
 	ipaux.$O\
+	iplocalonifc.$O\
+	ipremoteonifc.$O\
 	ptclbsum.$O\
 
 HFILES=\