bindresvport related changes

 -changed bindresvport2 to bindresvport_sa
 -merged the man into bindresvport.3

All discussion between Jean-Luc Richier <Jean-Luc.Richier@imag.fr>,
Theo de Raadt <deraadt@cvs.openbsd.org>, itojun, is reflected to
this code. (Actually Theo de Raadt write the code simultaneously as the
discussion change.)

4 files changed, 138 insertions, 75 deletions

diff --git a/lib/libc/net/rcmd.c b/lib/libc/net/rcmd.c
index 8130410..d46410a 100644
--- a/lib/libc/net/rcmd.c
+++ b/lib/libc/net/rcmd.c
@@ -333,8 +333,8 @@ rresvport_af(alport, family)
 	}
 #endif
 	*sport = 0;
-	if (bindresvport2(s, (struct sockaddr *)&ss,
-			  ((struct sockaddr *)&ss)->sa_len) == -1) {
+	if (bindresvport_sa(s, (struct sockaddr *)&ss,
+			    ((struct sockaddr *)&ss)->sa_len) == -1) {
 		(void)_libc_close(s);
 		return (-1);
 	}
diff --git a/lib/libc/rpc/Makefile.inc b/lib/libc/rpc/Makefile.inc
index 472cea7..1ca21c5 100644
--- a/lib/libc/rpc/Makefile.inc
+++ b/lib/libc/rpc/Makefile.inc
@@ -44,13 +44,13 @@ crypt.h: ${RPCDIR}/crypt.x
 #
 
 # MAN1+=	rstat.1
-MAN3+=	bindresvport.3 bindresvport2.3 des_crypt.3 getrpcent.3 getrpcport.3 \
-	publickey.3 rpc.3 \
+MAN3+=	bindresvport.3 des_crypt.3 getrpcent.3 getrpcport.3 publickey.3 rpc.3 \
 	rpc_secure.3 rtime.3
 MAN5+=	publickey.5 rpc.5
 # MAN8+=	rstat_svc.8
 
-MLINKS+=	getrpcent.3 endrpcent.3 \
+MLINKS+=	bindresvport.3 bindresvport_sa.3 \
+		getrpcent.3 endrpcent.3 \
 		getrpcent.3 getrpcbyname.3 \
 		getrpcent.3 getrpcbynumber.3 \
 		getrpcent.3 setrpcent.3 \
diff --git a/lib/libc/rpc/bindresvport.3 b/lib/libc/rpc/bindresvport.3
index 8d1f975..d37aeff 100644
--- a/lib/libc/rpc/bindresvport.3
+++ b/lib/libc/rpc/bindresvport.3
@@ -5,30 +5,99 @@
 .Dt BINDRESVPORT 3
 .Os
 .Sh NAME
-.Nm bindresvport
+.Nm bindresvport ,
+.Nm bindresvport_sa ,
 .Ndbind a socket to a privileged IP port
 .Sh SYNOPSIS
 .Fd #include <sys/types.h>
 .Fd #include <netinet/in.h>
 .Ft int
-.Fn bindresvport "int sd" "struct sockaddr_in **sin"
+.Fn bindresvport "int sd" "struct sockaddr_in *sin"
+.Ft int
+.Fn bindresvport_sa "int sd" "struct sockaddr *sa"
 .Sh DESCRIPTION
 .Nm Bindresvport
-is used to bind a socket descriptor to a privileged
+and
+.Nm Bindresvport_sa
+are used to bind a socket descriptor to a privileged
 .Tn IP
 port, that is, a
 port number in the range 0-1023.
-The routine returns 0 if it is successful,
-otherwise -1 is returned and
-.Va errno
-set to reflect the cause of the error.
 .Pp
 Only root can bind to a privileged port; this call will fail for any
 other users.
 .Pp
+When
+.Va sin
+is not null,
+.Va sin->sin_family
+must be initialized to the address family of the socket, passed by
+.Va sd .
 If the value of sin->sin_port is non-zero
 .Fn bindresvport
 will attempt to use that specific port.  If it fails, it chooses another
 privileged port automatically.
+.Pp
+It is legal to pass null pointer to
+.Va sin .
+In this case, the caller cannot get the port number
+.Fn bindresvport
+has picked.
+.Pp
+Function prototype of
+.Fn bindresvport
+is biased to
+.Dv AF_INET
+socket.
+.Fn bindresvport_sa
+acts exactly the same, with more neutral function prototype.
+Note that both functions behave exactly the same, and
+both support
+.Dv AF_INET6
+sockets as well as
+.Dv AF_INET
+sockets.
+.Sh RETURN VALUES
+.Fn bindresvport
+returns 0 if it is successful, otherwise \-1 is returned and
+.Va errno
+set to reflect the cause of the error.
+.Sh ERRORS
+The
+.Fn bindresvport
+function fails if:
+.Bl -tag -width Er
+.It Bq Er EBADF
+.Fa sd
+is not a valid descriptor.
+.It Bq Er ENOTSOCK
+.Fa sd
+is not a socket.
+.It Bq Er EADDRNOTAVAIL
+The specified address is not available from the local machine.
+.It Bq Er EADDRINUSE
+The specified address is already in use.
+.It Bq Er EINVAL
+The socket is already bound to an address,
+or the socket family and the family of specified address mismatch.
+.It Bq Er EACCES
+The requested address is protected, and the current user
+has inadequate permission to access it.
+.It Bq Er EFAULT
+The
+.Fa name
+parameter is not in a valid part of the user
+address space.
+.It Bq Er ENOBUFS
+Insufficient resources were available in the system
+to perform the operation.
+.It Bq Er EPFNOSUPPORT
+The protocol family has not been configured into the
+system, no implementation for it exists,
+or address family did not match between arguments.
+.El
 .Sh "SEE ALSO"
-.Xr bindresvport2 3
\ No newline at end of file
+.Xr bind 2 ,
+.Xr socket 2 ,
+.Xr rresvport 3 ,
+.Xr rresvport_af 3
diff --git a/lib/libc/rpc/bindresvport.c b/lib/libc/rpc/bindresvport.c
index e8e8c15..fb43eed 100644
--- a/lib/libc/rpc/bindresvport.c
+++ b/lib/libc/rpc/bindresvport.c
@@ -55,95 +55,89 @@ bindresvport(sd, sin)
 	int sd;
 	struct sockaddr_in *sin;
 {
-	struct sockaddr_in myaddr;
-	int sinlen = sizeof(struct sockaddr_in);
-
-	if (sin == (struct sockaddr_in *)0) {
-		sin = &myaddr;
-		memset(sin, 0, sinlen);
-		sin->sin_len = sinlen;
-		sin->sin_family = AF_INET;
-	} else if (sin->sin_family != AF_INET) {
-		errno = EPFNOSUPPORT;
-		return (-1);
-	}
-
-	return (bindresvport2(sd, sin, sinlen));
+	return bindresvport_sa(sd, (struct sockaddr *)sin);
 }
 
+/*
+ * Bind a socket to a privileged port for whatever protocol.
+ */
 int
-bindresvport2(sd, sa, addrlen)
+bindresvport_sa(sd, sa)
 	int sd;
 	struct sockaddr *sa;
-	socklen_t addrlen;
 {
-	int on, old, error, level, optname;
-	u_short port;
+	int old, error, af;
+	struct sockaddr_storage myaddr;
+	struct sockaddr_in *sin;
+	struct sockaddr_in6 *sin6;
+	int proto, portrange, portlow;
+	u_int16_t port;
+	int salen;
 
 	if (sa == NULL) {
-		errno = EINVAL;
-		return (-1);
-	}
-	switch (sa->sa_family) {
-	case AF_INET:
-		port = ntohs(((struct sockaddr_in *)sa)->sin_port);
-		level = IPPROTO_IP;
-		optname = IP_PORTRANGE;
-		on = IP_PORTRANGE_LOW;
-		break;
-#ifdef INET6
-	case AF_INET6:
-		port = ntohs(((struct sockaddr_in6 *)sa)->sin6_port);
-		level = IPPROTO_IPV6;
-		optname = IPV6_PORTRANGE;
-		on = IPV6_PORTRANGE_LOW;
-		break;
-#endif
-	default:
-		errno = EAFNOSUPPORT;
+		salen = sizeof(myaddr);
+		sa = (struct sockaddr *)&myaddr;
+
+		if (getsockname(sd, sa, &salen) == -1)
+			return -1;	/* errno is correctly set */
+
+		af = sa->sa_family;
+		memset(&myaddr, 0, salen);
+	} else
+		af = sa->sa_family;
+
+	if (af == AF_INET) {
+		proto = IPPROTO_IP;
+		portrange = IP_PORTRANGE;
+		portlow = IP_PORTRANGE_LOW;
+		sin = (struct sockaddr_in *)sa;
+		salen = sizeof(struct sockaddr_in);
+		port = sin->sin_port;
+	} else if (af == AF_INET6) {
+		proto = IPPROTO_IPV6;
+		portrange = IPV6_PORTRANGE;
+		portlow = IPV6_PORTRANGE_LOW;
+		sin6 = (struct sockaddr_in6 *)sa;
+		salen = sizeof(struct sockaddr_in6);
+		port = sin6->sin6_port;
+	} else {
+		errno = EPFNOSUPPORT;
 		return (-1);
 	}
+	sa->sa_family = af;
+	sa->sa_len = salen;
 
 	if (port == 0) {
 		int oldlen = sizeof(old);
-		error = getsockopt(sd, level, optname, &old, &oldlen);
+
+		error = getsockopt(sd, proto, portrange, &old, &oldlen);
 		if (error < 0)
-			return(error);
+			return (error);
 
-		error = setsockopt(sd, level, optname, &on, sizeof(on));
+		error = setsockopt(sd, proto, portrange, &portlow,
+		    sizeof(portlow));
 		if (error < 0)
-			return(error);
+			return (error);
 	}
 
-	error = bind(sd, sa, addrlen);
+	error = bind(sd, sa, salen);
 
-	switch (sa->sa_family) {
-	case AF_INET:
-		port = ntohs(((struct sockaddr_in *)sa)->sin_port);
-		break;
-#ifdef INET6
-	case AF_INET6:
-		port = ntohs(((struct sockaddr_in6 *)sa)->sin6_port);
-		break;
-#endif
-	default: /* shoud not match here */
-		errno = EAFNOSUPPORT;
-		return (-1);
-	}
 	if (port == 0) {
 		int saved_errno = errno;
 
 		if (error) {
-			if (setsockopt(sd, level, optname,
-			    &old, sizeof(old)) < 0)
+			if (setsockopt(sd, proto, portrange, &old,
+			    sizeof(old)) < 0)
 				errno = saved_errno;
 			return (error);
 		}
 
-		/* Hmm, what did the kernel assign... */
-		if (getsockname(sd, (struct sockaddr *)sa, &addrlen) < 0)
-			errno = saved_errno;
-		return (error);
+		if (sa != (struct sockaddr *)&myaddr) {
+			/* Hmm, what did the kernel assign... */
+			if (getsockname(sd, sa, &salen) < 0)
+				errno = saved_errno;
+			return (error);
+		}
 	}
 	return (error);
 }