1 files changed, 162 insertions, 376 deletions

diff --git a/src/lib/libc/net/rcmd.c b/src/lib/libc/net/rcmd.c
index e0310031b0..d566e0ca4c 100644
--- a/src/lib/libc/net/rcmd.c
+++ b/src/lib/libc/net/rcmd.c
@@ -1,6 +1,5 @@
-/*      $NetBSD: rcmd.c,v 1.12 1995/06/03 22:33:34 mycroft Exp $        */
-
 /*
+ * Copyright (c) 1995, 1996, 1998 Theo de Raadt.  All rights reserved.
  * Copyright (c) 1983, 1993, 1994
  *      The Regents of the University of California.  All rights reserved.
  *
@@ -12,11 +11,7 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *      This product includes software developed by the University of
- *      California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
+ * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
@@ -33,14 +28,6 @@
  * SUCH DAMAGE.
  */
 
-#if defined(LIBC_SCCS) && !defined(lint)
-#if 0
-static char sccsid[] = "@(#)rcmd.c      8.3 (Berkeley) 3/26/94";
-#else
-static char *rcsid = "$NetBSD: rcmd.c,v 1.12 1995/06/03 22:33:34 mycroft Exp $";
-#endif
-#endif /* LIBC_SCCS and not lint */
-
 #include <sys/param.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
@@ -57,35 +44,77 @@ static char *rcsid = "$NetBSD: rcmd.c,v 1.12 1995/06/03 22:33:34 mycroft Exp $";
 #include <stdio.h>
 #include <ctype.h>
 #include <string.h>
+#include <syslog.h>
+#include <stdlib.h>
 
-int     __ivaliduser __P((FILE *, u_long, const char *, const char *));
-static int __icheckhost __P((u_long, const char *));
+int
+rcmd(char **ahost, int rport, const char *locuser, const char *remuser,
+    const char *cmd, int *fd2p)
+{
+        return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
+}
 
 int
-rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
-        char **ahost;
-        u_short rport;
-        const char *locuser, *remuser, *cmd;
-        int *fd2p;
+rcmd_af(char **ahost, int porta, const char *locuser, const char *remuser,
+    const char *cmd, int *fd2p, int af)
 {
-        struct hostent *hp;
-        struct sockaddr_in sin, from;
-        fd_set reads;
-        long oldmask;
+        static char hbuf[MAXHOSTNAMELEN];
+        char pbuf[NI_MAXSERV];
+        struct addrinfo hints, *res, *r;
+        int error;
+        struct sockaddr_storage from;
+        fd_set *readsp = NULL;
+        sigset_t oldmask, mask;
         pid_t pid;
         int s, lport, timo;
-        char c;
+        char c, *p;
+        int refused;
+        in_port_t rport = porta;
+
+        /* call rcmdsh() with specified remote shell if appropriate. */
+        if (!issetugid() && (p = getenv("RSH")) && *p) {
+                struct servent *sp = getservbyname("shell", "tcp");
+
+                if (sp && sp->s_port == rport)
+                        return (rcmdsh(ahost, rport, locuser, remuser,
+                            cmd, p));
+        }
+
+        /* use rsh(1) if non-root and remote port is shell. */
+        if (geteuid()) {
+                struct servent *sp = getservbyname("shell", "tcp");
+
+                if (sp && sp->s_port == rport)
+                        return (rcmdsh(ahost, rport, locuser, remuser,
+                            cmd, NULL));
+        }
 
         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;
-        oldmask = sigblock(sigmask(SIGURG));
+        if (res->ai_canonname) {
+                strlcpy(hbuf, res->ai_canonname, sizeof(hbuf));
+                *ahost = hbuf;
+        } else
+                ; /*XXX*/
+
+        r = res;
+        refused = 0;
+        sigemptyset(&mask);
+        sigaddset(&mask, SIGURG);
+        sigprocmask(SIG_BLOCK, &mask, &oldmask);
         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,
@@ -93,54 +122,84 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
                         else
                                 (void)fprintf(stderr, "rcmd: socket: %s\n",
                                     strerror(errno));
-                        sigsetmask(oldmask);
-                        return (-1);
+                        if (r->ai_next) {
+                                r = r->ai_next;
+                                continue;
+                        } else {
+                                sigprocmask(SIG_SETMASK, &oldmask, NULL);
+                                freeaddrinfo(res);
+                                return (-1);
+                        }
                 }
                 fcntl(s, F_SETOWN, pid);
-                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) {
                         lport--;
                         continue;
                 }
-                if (errno == ECONNREFUSED && timo <= 16) {
-                        (void)sleep(timo);
-                        timo *= 2;
-                        continue;
-                }
-                if (hp->h_addr_list[1] != NULL) {
+                if (errno == ECONNREFUSED)
+                        refused++;
+                if (r->ai_next) {
                         int oerrno = errno;
-
-                        (void)fprintf(stderr, "connect to address %s: ",
-                            inet_ntoa(sin.sin_addr));
+                        char hbuf[NI_MAXHOST];
+                        const int niflags = NI_NUMERICHOST;
+
+                        hbuf[0] = '\0';
+                        if (getnameinfo(r->ai_addr, r->ai_addrlen,
+                            hbuf, sizeof(hbuf), NULL, 0, niflags) != 0)
+                                strlcpy(hbuf, "(invalid)", sizeof hbuf);
+                        (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)
+                                strlcpy(hbuf, "(invalid)", sizeof hbuf);
+                        (void)fprintf(stderr, "Trying %s...\n", hbuf);
                         continue;
                 }
-                (void)fprintf(stderr, "%s: %s\n", hp->h_name, strerror(errno));
-                sigsetmask(oldmask);
+                if (refused && timo <= 16) {
+                        (void)sleep(timo);
+                        timo *= 2;
+                        r = res;
+                        refused = 0;
+                        continue;
+                }
+                (void)fprintf(stderr, "%s: %s\n", res->ai_canonname,
+                    strerror(errno));
+                sigprocmask(SIG_SETMASK, &oldmask, NULL);
+                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()
+         * fail it's first bind, resulting in it choosing a random port.
+         */
         lport--;
+#endif
         if (fd2p == 0) {
                 write(s, "", 1);
                 lport = 0;
         } else {
                 char num[8];
-                int s2 = rresvport(&lport), s3;
-                int len = sizeof(from);
+                int s2 = rresvport_af(&lport, af), s3;
+                socklen_t len = sizeof(from);
+                int fdssize = howmany(MAX(s, s2)+1, NFDBITS) * sizeof(fd_mask);
 
                 if (s2 < 0)
                         goto bad;
+                readsp = (fd_set *)malloc(fdssize);
+                if (readsp == NULL) {
+                        close(s2);
+                        goto bad;
+                }
                 listen(s2, 1);
                 (void)snprintf(num, sizeof(num), "%d", lport);
                 if (write(s, num, strlen(num)+1) != strlen(num)+1) {
@@ -150,12 +209,13 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
                         (void)close(s2);
                         goto bad;
                 }
-                FD_ZERO(&reads);
-                FD_SET(s, &reads);
-                FD_SET(s2, &reads);
+again:
+                bzero(readsp, fdssize);
+                FD_SET(s, readsp);
+                FD_SET(s2, readsp);
                 errno = 0;
-                if (select(MAX(s, s2) + 1, &reads, 0, 0, 0) < 1 ||
-                    !FD_ISSET(s2, &reads)) {
+                if (select(MAX(s, s2) + 1, readsp, 0, 0, 0) < 1 ||
+                    !FD_ISSET(s2, readsp)) {
                         if (errno != 0)
                                 (void)fprintf(stderr,
                                     "rcmd: select (setting up stderr): %s\n",
@@ -167,21 +227,48 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
                         goto bad;
                 }
                 s3 = accept(s2, (struct sockaddr *)&from, &len);
-                (void)close(s2);
                 if (s3 < 0) {
                         (void)fprintf(stderr,
                             "rcmd: accept: %s\n", strerror(errno));
                         lport = 0;
+                        close(s2);
                         goto bad;
                 }
+
+                /*
+                 * XXX careful for ftp bounce attacks. If discovered, shut them
+                 * down and check for the real auxiliary channel to connect.
+                 */
+                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);
+
                 *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);
@@ -200,318 +287,17 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
                 }
                 goto bad2;
         }
-        sigsetmask(oldmask);
+        sigprocmask(SIG_SETMASK, &oldmask, NULL);
+        free(readsp);
         return (s);
 bad2:
         if (lport)
                 (void)close(*fd2p);
 bad:
+        if (readsp)
+                free(readsp);
         (void)close(s);
-        sigsetmask(oldmask);
-        return (-1);
-}
-
-int
-rresvport(alport)
-        int *alport;
-{
-        struct sockaddr_in sin;
-        int s;
-
-        sin.sin_len = sizeof(struct sockaddr_in);
-        sin.sin_family = AF_INET;
-        sin.sin_addr.s_addr = INADDR_ANY;
-        s = socket(AF_INET, SOCK_STREAM, 0);
-        if (s < 0)
-                return (-1);
-        for (;;) {
-                sin.sin_port = htons((u_short)*alport);
-                if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
-                        return (s);
-                if (errno != EADDRINUSE) {
-                        (void)close(s);
-                        return (-1);
-                }
-                (*alport)--;
-                if (*alport == IPPORT_RESERVED/2) {
-                        (void)close(s);
-                        errno = EAGAIN;         /* close */
-                        return (-1);
-                }
-        }
-}
-
-int     __check_rhosts_file = 1;
-char    *__rcmd_errstr;
-
-int
-ruserok(rhost, superuser, ruser, luser)
-        const char *rhost, *ruser, *luser;
-        int superuser;
-{
-        struct hostent *hp;
-        char **ap;
-        int i;
-#define MAXADDRS        35
-        u_long addrs[MAXADDRS + 1];
-
-        if ((hp = gethostbyname(rhost)) == NULL)
-                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(addrs[i], superuser, ruser, luser) == 0)
-                        return (0);
-        return (-1);
-}
-
-/*
- * New .rhosts strategy: We are passed an ip address. We spin through
- * hosts.equiv and .rhosts looking for a match. When the .rhosts only
- * has ip addresses, we don't have to trust a nameserver.  When it
- * contains hostnames, we spin through the list of addresses the nameserver
- * gives us and look for a match.
- *
- * Returns 0 if ok, -1 if not ok.
- */
-int
-iruserok(raddr, superuser, ruser, luser)
-        u_long raddr;
-        int superuser;
-        const char *ruser, *luser;
-{
-        register char *cp;
-        struct stat sbuf;
-        struct passwd *pwd;
-        FILE *hostf;
-        uid_t uid;
-        int first;
-        char pbuf[MAXPATHLEN];
-
-        first = 1;
-        hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r");
-again:
-        if (hostf) {
-                if (__ivaliduser(hostf, raddr, luser, ruser) == 0) {
-                        (void)fclose(hostf);
-                        return (0);
-                }
-                (void)fclose(hostf);
-        }
-        if (first == 1 && (__check_rhosts_file || superuser)) {
-                first = 0;
-                if ((pwd = getpwnam(luser)) == NULL)
-                        return (-1);
-                (void)strcpy(pbuf, pwd->pw_dir);
-                (void)strcat(pbuf, "/.rhosts");
-
-                /*
-                 * Change effective uid while opening .rhosts.  If root and
-                 * reading an NFS mounted file system, can't read files that
-                 * are protected read/write owner only.
-                 */
-                uid = geteuid();
-                (void)seteuid(pwd->pw_uid);
-                hostf = fopen(pbuf, "r");
-                (void)seteuid(uid);
-
-                if (hostf == NULL)
-                        return (-1);
-                /*
-                 * If not a regular file, or is owned by someone other than
-                 * user or root or if writeable by anyone but the owner, quit.
-                 */
-                cp = NULL;
-                if (lstat(pbuf, &sbuf) < 0)
-                        cp = ".rhosts lstat failed";
-                else if (!S_ISREG(sbuf.st_mode))
-                        cp = ".rhosts not regular file";
-                else if (fstat(fileno(hostf), &sbuf) < 0)
-                        cp = ".rhosts fstat failed";
-                else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid)
-                        cp = "bad .rhosts owner";
-                else if (sbuf.st_mode & (S_IWGRP|S_IWOTH))
-                        cp = ".rhosts writeable by other than owner";
-                /* If there were any problems, quit. */
-                if (cp) {
-                        __rcmd_errstr = cp;
-                        (void)fclose(hostf);
-                        return (-1);
-                }
-                goto again;
-        }
+        sigprocmask(SIG_SETMASK, &oldmask, NULL);
         return (-1);
 }
 
-/*
- * XXX
- * Don't make static, used by lpd(8).
- *
- * Returns 0 if ok, -1 if not ok.
- */
-int
-__ivaliduser(hostf, raddr, luser, ruser)
-        FILE *hostf;
-        u_long raddr;
-        const char *luser, *ruser;
-{
-        register char *user, *p;
-        int ch;
-        char buf[MAXHOSTNAMELEN + 128];         /* host + login */
-        const char *auser, *ahost;
-        int hostok, userok;
-        char rhost[MAXHOSTNAMELEN];
-        struct hostent *hp;
-        char domain[MAXHOSTNAMELEN];
-
-        getdomainname(domain, sizeof(domain));
-
-        while (fgets(buf, sizeof(buf), hostf)) {
-                p = buf;
-                /* Skip lines that are too long. */
-                if (strchr(p, '\n') == NULL) {
-                        while ((ch = getc(hostf)) != '\n' && ch != EOF);
-                        continue;
-                }
-                while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
-                        *p = isupper(*p) ? tolower(*p) : *p;
-                        p++;
-                }
-                if (*p == ' ' || *p == '\t') {
-                        *p++ = '\0';
-                        while (*p == ' ' || *p == '\t')
-                                p++;
-                        user = p;
-                        while (*p != '\n' && *p != ' ' &&
-                            *p != '\t' && *p != '\0')
-                                p++;
-                } else
-                        user = p;
-                *p = '\0';
-
-                if (p == buf)
-                        continue;
-
-                auser = *user ? user : luser;
-                ahost = buf;
-
-                if ((hp = gethostbyaddr((char *) &raddr,
-                                        sizeof(raddr), AF_INET)) == NULL) {
-                        abort();
-                        return -1;
-                }
-                (void) strncpy(rhost, hp->h_name, sizeof(rhost));
-                rhost[sizeof(rhost) - 1] = '\0';
-
-                if (ahost[0] == '+')
-                        switch (ahost[1]) {
-                        case '\0':
-                                hostok = 1;
-                                break;
-
-                        case '@':
-                                hostok = innetgr(&ahost[2], rhost, NULL,
-                                                 domain);
-                                break;
-
-                        default:
-                                hostok = __icheckhost(raddr, &ahost[1]);
-                                break;
-                        }
-                else if (ahost[0] == '-')
-                        switch (ahost[1]) {
-                        case '\0':
-                                hostok = -1;
-                                break;
-
-                        case '@':
-                                hostok = -innetgr(&ahost[2], rhost, NULL,
-                                                  domain);
-                                break;
-
-                        default:
-                                hostok = -__icheckhost(raddr, &ahost[1]);
-                                break;
-                        }
-                else
-                        hostok = __icheckhost(raddr, ahost);
-
-
-                if (auser[0] == '+')
-                        switch (auser[1]) {
-                        case '\0':
-                                userok = 1;
-                                break;
-
-                        case '@':
-                                userok = innetgr(&auser[2], NULL, ruser,
-                                                 domain);
-                                break;
-
-                        default:
-                                userok = strcmp(ruser, &auser[1]) == 0;
-                                break;
-                        }
-                else if (auser[0] == '-')
-                        switch (auser[1]) {
-                        case '\0':
-                                userok = -1;
-                                break;
-
-                        case '@':
-                                userok = -innetgr(&auser[2], NULL, ruser,
-                                                  domain);
-                                break;
-
-                        default:
-                                userok = -(strcmp(ruser, &auser[1]) == 0);
-                                break;
-                        }
-                else
-                        userok = strcmp(ruser, auser) == 0;
-
-                /* Check if one component did not match */
-                if (hostok == 0 || userok == 0)
-                        continue;
-
-                /* Check if we got a forbidden pair */
-                if (userok == -1 || hostok == -1)
-                        return -1;
-
-                /* Check if we got a valid pair */
-                if (hostok == 1 && userok == 1)
-                        return 0;
-        }
-        return -1;
-}
-
-/*
- * Returns "true" if match, 0 if no match.
- */
-static int
-__icheckhost(raddr, lhost)
-        u_long raddr;
-        const char *lhost;
-{
-        register struct hostent *hp;
-        register u_long laddr;
-        register char **pp;
-
-        /* Try for raw ip address first. */
-        if (isdigit(*lhost) && (long)(laddr = inet_addr(lhost)) != -1)
-                return (raddr == laddr);
-
-        /* Better be a hostname. */
-        if ((hp = gethostbyname(lhost)) == NULL)
-                return (0);
-
-        /* Spin through ip addresses. */
-        for (pp = hp->h_addr_list; *pp; ++pp)
-                if (!bcmp(&raddr, *pp, sizeof(u_long)))
-                        return (1);
-
-        /* No match. */
-        return (0);
-}