add IPv6-ready rcmd() friends.

	rcmd(): IPv4 only
	rcmd_af(): af independent
	ruserok(): af independent
	iruserok(): IPv4 only
	iruserok_sa(): af independent

3 files changed, 264 insertions, 80 deletions

diff --git a/src/lib/libc/net/Makefile.inc b/src/lib/libc/net/Makefile.inc
index 447a96f1e1..7174d68220 100644
--- a/src/lib/libc/net/Makefile.inc
+++ b/src/lib/libc/net/Makefile.inc
@@ -1,4 +1,4 @@
-#       $OpenBSD: Makefile.inc,v 1.27 1999/12/16 21:30:34 deraadt Exp $
+#       $OpenBSD: Makefile.inc,v 1.28 2000/01/27 05:18:46 itojun Exp $
 
 # net sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_ARCH}/net ${LIBCSRCDIR}/net
@@ -65,7 +65,7 @@ MLINKS+=link_addr.3 link_ntoa.3
 MLINKS+=ipx.3 ipx_addr.3 ipx.3 ipx_ntoa.3
 MLINKS+=ns.3 ns_addr.3 ns.3 ns_ntoa.3
 MLINKS+=rcmd.3 iruserok.3 rcmd.3 rresvport.3 rcmd.3 ruserok.3 \
-        rcmd.3 rresvport_af.3
+        rcmd.3 rresvport_af.3 rcmd.3 rcmd_af.3 rcmd.3 iruserok_sa.3
 MLINKS+=resolver.3 dn_comp.3 resolver.3 dn_expand.3 resolver.3 res_init.3 \
         resolver.3 res_mkquery.3 resolver.3 res_send.3 resolver.3 res_query.3 \
         resolver.3 res_search.3
diff --git a/src/lib/libc/net/rcmd.3 b/src/lib/libc/net/rcmd.3
index fa7be72c8d..6df614b419 100644
--- a/src/lib/libc/net/rcmd.3
+++ b/src/lib/libc/net/rcmd.3
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: rcmd.3,v 1.16 2000/01/26 06:22:52 deraadt Exp $
+.\"     $OpenBSD: rcmd.3,v 1.17 2000/01/27 05:18:47 itojun Exp $
 .\"
 .\" Copyright (c) 1983, 1991, 1993
 .\"     The Regents of the University of California.  All rights reserved.
@@ -36,16 +36,20 @@
 .Os
 .Sh NAME
 .Nm rcmd ,
+.Nm rcmd_af ,
 .Nm rresvport ,
 .Nm rresvport_af ,
 .Nm iruserok ,
-.Nm ruserok
+.Nm ruserok ,
+.Nm iruserok_sa
 .Nd routines for returning a stream to a remote command
 .Sh SYNOPSIS
 .Fd #include <unistd.h>
 .Ft int
 .Fn rcmd "char **ahost" "int inport" "const char *locuser" "const char *remuser" "const char *cmd" "int *fd2p"
 .Ft int
+.Fn rcmd_af "char **ahost" "int inport" "const char *locuser" "const char *remuser" "const char *cmd" "int *fd2p" "int af"
+.Ft int
 .Fn rresvport "int *port"
 .Ft int
 .Fn rresvport_af "int *port" "int af"
@@ -53,6 +57,8 @@
 .Fn iruserok "u_int32_t raddr" "int superuser" "const char *ruser" "const char *luser"
 .Ft int
 .Fn ruserok "const char *rhost" "int superuser" "const char *ruser" "const char *luser"
+.Ft int
+.Fn iruserok_sa "const void *sa" "int salen" "int superuser" "const char *ruser"
 .Sh DESCRIPTION
 The
 .Fn rcmd
@@ -74,6 +80,12 @@ will invoke
 .Xr rcmdsh 3
 to run the command via
 .Xr rsh 1 .
+While
+.Fn rcmd
+can handle IPv4 cases only,
+the
+.Fn rcmd_af
+function can handle other cases as well.
 The
 .Fn rresvport
 and
@@ -92,6 +104,9 @@ All four functions are present in the same file and are used
 by the
 .Xr rshd 8
 server (among others).
+.Fn iruserok_sa
+is an address family independent variant of
+.Fn iruserok .
 .Pp
 The
 .Fn rcmd
@@ -142,6 +157,14 @@ Note that if the user is not the super-user,
 .Fa fd2p
 must be 0.
 .Pp
+.Fn rcmd_af
+takes address family in the last argument.
+If the last argument is
+.Dv PF_UNSPEC ,
+interpretation of
+.Fa *ahost
+will obey the underlying address resolution like DNS.
+.Pp
 The protocol is described in detail in
 .Xr rshd 8 .
 .Pp
@@ -200,6 +223,22 @@ If the IP address of the remote host is known,
 should be used in preference to
 .Fn ruserok ,
 as it does not require trusting the DNS server for the remote host's domain.
+.Pp
+While
+.Fn iruserok
+can handle IPv4 addresses only,
+.Fn iruserok_sa
+and
+.Fn ruserok
+can handle other address families as well, like IPv6.
+The first argument of
+.Fn iruserok_sa
+is typed as
+.Fa "void *"
+to avoid dependency between
+.Aq Li unistd.h
+and
+.Aq Li sys/socket.h .
 .Sh DIAGNOSTICS
 The
 .Fn rcmd
diff --git a/src/lib/libc/net/rcmd.c b/src/lib/libc/net/rcmd.c
index bd920faadb..79892bd5a1 100644
--- a/src/lib/libc/net/rcmd.c
+++ b/src/lib/libc/net/rcmd.c
@@ -34,7 +34,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char *rcsid = "$OpenBSD: rcmd.c,v 1.32 1999/12/16 21:30:34 deraadt Exp $";
+static char *rcsid = "$OpenBSD: rcmd.c,v 1.33 2000/01/27 05:18:47 itojun Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/param.h>
@@ -58,8 +58,9 @@ static char *rcsid = "$OpenBSD: rcmd.c,v 1.32 1999/12/16 21:30:34 deraadt Exp $"
 #include <netgroup.h>
 
 int     __ivaliduser __P((FILE *, in_addr_t, const char *, const char *));
-static int __icheckhost __P((u_int32_t, const char *));
-static char *__gethostloop __P((u_int32_t));
+int     __ivaliduser_sa __P((FILE *, struct sockaddr *, const char *, const char *));
+static int __icheckhost __P((struct sockaddr *, const char *));
+static char *__gethostloop __P((struct sockaddr *));
 
 int
 rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
@@ -68,8 +69,22 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
         const char *locuser, *remuser, *cmd;
         int *fd2p;
 {
-        struct hostent *hp;
-        struct sockaddr_in sin, from;
+        return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
+}
+
+int
+rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, af)
+        char **ahost;
+        in_port_t rport;
+        const char *locuser, *remuser, *cmd;
+        int *fd2p;
+        int af;
+{
+        static char hbuf[MAXHOSTNAMELEN];
+        char pbuf[NI_MAXSERV];
+        struct addrinfo hints, *res, *r;
+        int error;
+        struct sockaddr_storage from;
         fd_set *readsp = NULL;
         int oldmask;
         pid_t pid;
@@ -95,16 +110,29 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
         }
 
         pid = getpid();
-        hp = gethostbyname(*ahost);
-        if (hp == NULL) {
-                herror(*ahost);
+        snprintf(pbuf, sizeof(pbuf), "%u", ntohs(rport));
+        memset(&hints, 0, sizeof(hints));
+        hints.ai_family = af;
+        hints.ai_socktype = SOCK_STREAM;
+        hints.ai_flags = AI_CANONNAME;
+        error = getaddrinfo(*ahost, pbuf, &hints, &res);
+        if (error) {
+#if 0
+                warnx("%s: %s", *ahost, gai_strerror(error));
+#endif
                 return (-1);
         }
-        *ahost = hp->h_name;
-
+        if (res->ai_canonname) {
+                strncpy(hbuf, res->ai_canonname, sizeof(hbuf) - 1);
+                hbuf[sizeof(hbuf) - 1] = '\0';
+                *ahost = hbuf;
+        } else
+                ; /*XXX*/
+
+        r = res;
         oldmask = sigblock(sigmask(SIGURG));
         for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
-                s = rresvport(&lport);
+                s = rresvport_af(&lport, r->ai_family);
                 if (s < 0) {
                         if (errno == EAGAIN)
                                 (void)fprintf(stderr,
@@ -113,15 +141,11 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
                                 (void)fprintf(stderr, "rcmd: socket: %s\n",
                                     strerror(errno));
                         sigsetmask(oldmask);
+                        freeaddrinfo(res);
                         return (-1);
                 }
                 fcntl(s, F_SETOWN, pid);
-                bzero(&sin, sizeof sin);
-                sin.sin_len = sizeof(struct sockaddr_in);
-                sin.sin_family = hp->h_addrtype;
-                sin.sin_port = rport;
-                bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length);
-                if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
+                if (connect(s, r->ai_addr, r->ai_addrlen) >= 0)
                         break;
                 (void)close(s);
                 if (errno == EADDRINUSE) {
@@ -133,23 +157,39 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
                         timo *= 2;
                         continue;
                 }
-                if (hp->h_addr_list[1] != NULL) {
+                if (r->ai_next) {
                         int oerrno = errno;
+                        char hbuf[NI_MAXHOST];
+#ifdef NI_WITHSCOPEID
+                        const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID;
+#else
+                        const int niflags = NI_NUMERICHOST;
+#endif
 
-                        (void)fprintf(stderr, "connect to address %s: ",
-                            inet_ntoa(sin.sin_addr));
+                        hbuf[0] = '\0';
+                        if (getnameinfo(r->ai_addr, r->ai_addrlen,
+                            hbuf, sizeof(hbuf), NULL, 0, niflags) != 0)
+                                strcpy(hbuf, "(invalid)");
+                        (void)fprintf(stderr, "connect to address %s: ", hbuf);
                         errno = oerrno;
                         perror(0);
-                        hp->h_addr_list++;
-                        bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length);
-                        (void)fprintf(stderr, "Trying %s...\n",
-                            inet_ntoa(sin.sin_addr));
+                        r = r->ai_next;
+                        hbuf[0] = '\0';
+                        if (getnameinfo(r->ai_addr, r->ai_addrlen,
+                            hbuf, sizeof(hbuf), NULL, 0, niflags) != 0)
+                                strcpy(hbuf, "(invalid)");
+                        (void)fprintf(stderr, "Trying %s...\n", hbuf);
                         continue;
                 }
-                (void)fprintf(stderr, "%s: %s\n", hp->h_name, strerror(errno));
+                (void)fprintf(stderr, "%s: %s\n", res->ai_canonname,
+                    strerror(errno));
                 sigsetmask(oldmask);
+                freeaddrinfo(res);
                 return (-1);
         }
+        /* given "af" can be PF_UNSPEC, we need the real af for "s" */
+        af = r->ai_family;
+        freeaddrinfo(res);
 #if 0
         /*
          * try to rresvport() to the same port. This will make rresvport()
@@ -162,7 +202,7 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
                 lport = 0;
         } else {
                 char num[8];
-                int s2 = rresvport(&lport), s3;
+                int s2 = rresvport_af(&lport, af), s3;
                 int len = sizeof(from);
                 int fdssize = howmany(MAX(s, s2)+1, NFDBITS) * sizeof(fd_mask);
 
@@ -202,9 +242,18 @@ again:
                  * XXX careful for ftp bounce attacks. If discovered, shut them
                  * down and check for the real auxiliary channel to connect.
                  */
-                if (from.sin_family == AF_INET && from.sin_port == htons(20)) {
+                switch (from.ss_family) {
+                case AF_INET:
+                case AF_INET6:
+                        if (getnameinfo((struct sockaddr *)&from, len,
+                            NULL, 0, num, sizeof(num), NI_NUMERICSERV) == 0 &&
+                            atoi(num) != 20) {
+                                break;
+                        }
                         close(s3);
                         goto again;
+                default:
+                        break;
                 }
                 (void)close(s2);
                 if (s3 < 0) {
@@ -214,13 +263,20 @@ again:
                         goto bad;
                 }
                 *fd2p = s3;
-                from.sin_port = ntohs(from.sin_port);
-                if (from.sin_family != AF_INET ||
-                    from.sin_port >= IPPORT_RESERVED ||
-                    from.sin_port < IPPORT_RESERVED / 2) {
-                        (void)fprintf(stderr,
-                            "socket: protocol failure in circuit setup.\n");
-                        goto bad2;
+                switch (from.ss_family) {
+                case AF_INET:
+                case AF_INET6:
+                        if (getnameinfo((struct sockaddr *)&from, len,
+                            NULL, 0, num, sizeof(num), NI_NUMERICSERV) != 0 ||
+                            (atoi(num) >= IPPORT_RESERVED ||
+                             atoi(num) < IPPORT_RESERVED / 2)) {
+                                (void)fprintf(stderr,
+                                    "socket: protocol failure in circuit setup.\n");
+                                goto bad2;
+                        }
+                        break;
+                default:
+                        break;
                 }
         }
         (void)write(s, locuser, strlen(locuser)+1);
@@ -261,21 +317,24 @@ ruserok(rhost, superuser, ruser, luser)
         const char *rhost, *ruser, *luser;
         int superuser;
 {
-        struct hostent *hp;
-        char **ap;
-        int i;
-#define MAXADDRS        35
-        u_int32_t addrs[MAXADDRS + 1];
-
-        if ((hp = gethostbyname(rhost)) == NULL)
+        struct addrinfo hints, *res, *r;
+        int error;
+
+        memset(&hints, 0, sizeof(hints));
+        hints.ai_family = PF_UNSPEC;
+        hints.ai_socktype = SOCK_DGRAM; /*dummy*/
+        error = getaddrinfo(rhost, "0", &hints, &res);
+        if (error)
                 return (-1);
-        for (i = 0, ap = hp->h_addr_list; *ap && i < MAXADDRS; ++ap, ++i)
-                bcopy(*ap, &addrs[i], sizeof(addrs[i]));
-        addrs[i] = 0;
 
-        for (i = 0; i < MAXADDRS && addrs[i]; i++)
-                if (iruserok((in_addr_t)addrs[i], superuser, ruser, luser) == 0)
+        for (r = res; r; r = r->ai_next) {
+                if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser,
+                    luser) == 0) {
+                        freeaddrinfo(res);
                         return (0);
+                }
+        }
+        freeaddrinfo(res);
         return (-1);
 }
 
@@ -294,6 +353,24 @@ iruserok(raddr, superuser, ruser, luser)
         int superuser;
         const char *ruser, *luser;
 {
+        struct sockaddr_in sin;
+
+        memset(&sin, 0, sizeof(sin));
+        sin.sin_family = AF_INET;
+        sin.sin_len = sizeof(struct sockaddr_in);
+        memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
+        return iruserok_sa(&sin, sizeof(struct sockaddr_in), superuser, ruser,
+                    luser);
+}
+
+int
+iruserok_sa(raddr, rlen, superuser, ruser, luser)
+        const void *raddr;
+        int rlen;
+        int superuser;
+        const char *ruser, *luser;
+{
+        struct sockaddr *sa;
         register char *cp;
         struct stat sbuf;
         struct passwd *pwd;
@@ -302,11 +379,15 @@ iruserok(raddr, superuser, ruser, luser)
         int first;
         char pbuf[MAXPATHLEN];
 
+        sa = (struct sockaddr *)raddr;
+#ifdef lint
+        rlen = rlen;
+#endif
         first = 1;
         hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r");
 again:
         if (hostf) {
-                if (__ivaliduser(hostf, raddr, luser, ruser) == 0) {
+                if (__ivaliduser_sa(hostf, sa, luser, ruser) == 0) {
                         (void)fclose(hostf);
                         return (0);
                 }
@@ -369,13 +450,27 @@ __ivaliduser(hostf, raddrl, luser, ruser)
         in_addr_t raddrl;
         const char *luser, *ruser;
 {
+        struct sockaddr_in sin;
+
+        memset(&sin, 0, sizeof(sin));
+        sin.sin_family = AF_INET;
+        sin.sin_len = sizeof(struct sockaddr_in);
+        memcpy(&sin.sin_addr, &raddrl, sizeof(sin.sin_addr));
+        return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, luser, ruser);
+}
+
+int
+__ivaliduser_sa(hostf, raddr, luser, ruser)
+        FILE *hostf;
+        struct sockaddr *raddr;
+        const char *luser, *ruser;
+{
         register char *user, *p;
         char *buf;
         const char *auser, *ahost;
         int hostok, userok;
         char *rhost = (char *)-1;
         char domain[MAXHOSTNAMELEN];
-        u_int32_t raddr = (u_int32_t)raddrl;
         size_t buflen;
 
         getdomainname(domain, sizeof(domain));
@@ -509,27 +604,54 @@ bail:
 /*
  * Returns "true" if match, 0 if no match.  If we do not find any
  * semblance of an A->PTR->A loop, allow a simple #.#.#.# match to work.
+ *
+ * NI_WITHSCOPEID is useful for comparing sin6_scope_id portion
+ * if af == AF_INET6.
  */
 static int
 __icheckhost(raddr, lhost)
-        u_int32_t raddr;
+        struct sockaddr *raddr;
         const char *lhost;
 {
-        register struct hostent *hp;
-        register char **pp;
-        struct in_addr in;
-
-        hp = gethostbyname(lhost);
-        if (hp != NULL) {
-                /* Spin through ip addresses. */
-                for (pp = hp->h_addr_list; *pp; ++pp)
-                        if (!bcmp(&raddr, *pp, sizeof(raddr)))
-                                return (1);
+        struct addrinfo hints, *res, *r;
+        char h1[NI_MAXHOST], h2[NI_MAXHOST];
+        int error;
+#ifdef NI_WITHSCOPEID
+        const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID;
+#else
+        const int niflags = NI_NUMERICHOST;
+#endif
+
+        h1[0] = '\0';
+        if (getnameinfo(raddr, raddr->sa_len, h1, sizeof(h1), NULL, 0,
+            niflags) != 0)
+                return (0);
+
+        /* Resolve laddr into sockaddr */
+        memset(&hints, 0, sizeof(hints));
+        hints.ai_family = raddr->sa_family;
+        hints.ai_socktype = SOCK_DGRAM; /*dummy*/
+        res = NULL;
+        error = getaddrinfo(lhost, "0", &hints, &res);
+        if (error)
+                return (0);
+
+        /*
+         * Try string comparisons between raddr and laddr.
+         */
+        for (r = res; r; r = r->ai_next) {
+                h2[0] = '\0';
+                if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2),
+                    NULL, 0, niflags) != 0)
+                        continue;
+                if (strcmp(h1, h2) == 0) {
+                        freeaddrinfo(res);
+                        return (1);
+                }
         }
 
-        in.s_addr = raddr;
-        if (strcmp(lhost, inet_ntoa(in)) == 0)
-                return (1);
+        /* No match. */
+        freeaddrinfo(res);
         return (0);
 }
 
@@ -537,39 +659,62 @@ __icheckhost(raddr, lhost)
  * Return the hostname associated with the supplied address.
  * Do a reverse lookup as well for security. If a loop cannot
  * be found, pack the result of inet_ntoa() into the string.
+ *
+ * NI_WITHSCOPEID is useful for comparing sin6_scope_id portion
+ * if af == AF_INET6.
  */
 static char *
 __gethostloop(raddr)
-        u_int32_t raddr;
+        struct sockaddr *raddr;
 {
-        static char remotehost[MAXHOSTNAMELEN];
-        struct hostent *hp;
-        struct in_addr in;
+        static char remotehost[NI_MAXHOST];
+        char h1[NI_MAXHOST], h2[NI_MAXHOST];
+        struct addrinfo hints, *res, *r;
+        int error;
+#ifdef NI_WITHSCOPEID
+        const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID;
+#else
+        const int niflags = NI_NUMERICHOST;
+#endif
 
-        hp = gethostbyaddr((char *) &raddr, sizeof(raddr), AF_INET);
-        if (hp == NULL)
+        h1[0] = remotehost[0] = '\0';
+        if (getnameinfo(raddr, raddr->sa_len, remotehost, sizeof(remotehost),
+            NULL, 0, NI_NAMEREQD) != 0)
+                return (NULL);
+        if (getnameinfo(raddr, raddr->sa_len, h1, sizeof(h1), NULL, 0,
+            niflags) != 0)
                 return (NULL);
 
         /*
          * Look up the name and check that the supplied
          * address is in the list
          */
-        strncpy(remotehost, hp->h_name, sizeof(remotehost) - 1);
-        remotehost[sizeof(remotehost) - 1] = '\0';
-        hp = gethostbyname(remotehost);
-        if (hp == NULL)
+        memset(&hints, 0, sizeof(hints));
+        hints.ai_family = raddr->sa_family;
+        hints.ai_socktype = SOCK_DGRAM; /*dummy*/
+        hints.ai_flags = AI_CANONNAME;
+        res = NULL;
+        error = getaddrinfo(remotehost, "0", &hints, &res);
+        if (error)
                 return (NULL);
 
-        for (; hp->h_addr_list[0] != NULL; hp->h_addr_list++)
-                if (!bcmp(hp->h_addr_list[0], (caddr_t)&raddr, sizeof(raddr)))
+        for (r = res; r; r = r->ai_next) {
+                h2[0] = '\0';
+                if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2),
+                    NULL, 0, niflags) != 0)
+                        continue;
+                if (strcmp(h1, h2) == 0) {
+                        freeaddrinfo(res);
                         return (remotehost);
+                }
+        }
 
         /*
          * either the DNS adminstrator has made a configuration
          * mistake, or someone has attempted to spoof us
          */
-        in.s_addr = raddr;
         syslog(LOG_NOTICE, "rcmd: address %s not listed for host %s",
-            inet_ntoa(in), hp->h_name);
+            h1, res->ai_canonname ? res->ai_canonname : remotehost);
+        freeaddrinfo(res);
         return (NULL);
 }