diff options
Diffstat (limited to 'inet/rcmd.c')
| -rw-r--r-- | inet/rcmd.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/inet/rcmd.c b/inet/rcmd.c new file mode 100644 index 0000000..e5b28c6 --- /dev/null +++ b/inet/rcmd.c @@ -0,0 +1,414 @@ +/* + * Copyright (c) 1983, 1993, 1994 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 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 + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)rcmd.c 8.3 (Berkeley) 3/26/94"; +#endif /* LIBC_SCCS and not lint */ + +#include <sys/param.h> +#include <sys/socket.h> +#include <sys/stat.h> + +#include <netinet/in.h> +#include <arpa/inet.h> + +#include <signal.h> +#include <fcntl.h> +#include <netdb.h> +#include <unistd.h> +#include <pwd.h> +#include <errno.h> +#include <stdio.h> +#include <ctype.h> +#include <string.h> + +int __ivaliduser __P((FILE *, u_long, const char *, const char *)); +static int __icheckhost __P((u_long, char *)); + +int +rcmd(ahost, rport, locuser, remuser, cmd, fd2p) + char **ahost; + u_short rport; + const char *locuser, *remuser, *cmd; + int *fd2p; +{ + struct hostent *hp; + struct sockaddr_in sin, from; + fd_set reads; + long oldmask; + pid_t pid; + int s, lport, timo; + char c; + + pid = getpid(); + hp = gethostbyname(*ahost); + if (hp == NULL) { + herror(*ahost); + return (-1); + } + *ahost = hp->h_name; + oldmask = sigblock(sigmask(SIGURG)); + for (timo = 1, lport = IPPORT_RESERVED - 1;;) { + s = rresvport(&lport); + if (s < 0) { + if (errno == EAGAIN) + (void)fprintf(stderr, + "rcmd: socket: All ports in use\n"); + else + (void)fprintf(stderr, "rcmd: socket: %s\n", + strerror(errno)); + sigsetmask(oldmask); + return (-1); + } + fcntl(s, F_SETOWN, pid); + sin.sin_family = hp->h_addrtype; + bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length); + sin.sin_port = rport; + if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 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) { + int oerrno = errno; + + (void)fprintf(stderr, "connect to address %s: ", + inet_ntoa(sin.sin_addr)); + 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)); + continue; + } + (void)fprintf(stderr, "%s: %s\n", hp->h_name, strerror(errno)); + sigsetmask(oldmask); + return (-1); + } + lport--; + if (fd2p == 0) { + write(s, "", 1); + lport = 0; + } else { + char num[8]; + int s2 = rresvport(&lport), s3; + int len = sizeof(from); + + if (s2 < 0) + goto bad; + listen(s2, 1); + (void)snprintf(num, sizeof(num), "%d", lport); + if (write(s, num, strlen(num)+1) != strlen(num)+1) { + (void)fprintf(stderr, + "rcmd: write (setting up stderr): %s\n", + strerror(errno)); + (void)close(s2); + goto bad; + } + FD_ZERO(&reads); + FD_SET(s, &reads); + FD_SET(s2, &reads); + errno = 0; + if (select(1 + (s > s2 ? s : s2), &reads, 0, 0, 0) < 1 || + !FD_ISSET(s2, &reads)) { + if (errno != 0) + (void)fprintf(stderr, + "rcmd: select (setting up stderr): %s\n", + strerror(errno)); + else + (void)fprintf(stderr, + "select: protocol failure in circuit setup\n"); + (void)close(s2); + 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; + goto bad; + } + *fd2p = s3; + from.sin_port = ntohs((u_short)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; + } + } + (void)write(s, locuser, strlen(locuser)+1); + (void)write(s, remuser, strlen(remuser)+1); + (void)write(s, cmd, strlen(cmd)+1); + if (read(s, &c, 1) != 1) { + (void)fprintf(stderr, + "rcmd: %s: %s\n", *ahost, strerror(errno)); + goto bad2; + } + if (c != 0) { + while (read(s, &c, 1) == 1) { + (void)write(STDERR_FILENO, &c, 1); + if (c == '\n') + break; + } + goto bad2; + } + sigsetmask(oldmask); + return (s); +bad2: + if (lport) + (void)close(*fd2p); +bad: + (void)close(s); + sigsetmask(oldmask); + return (-1); +} + +int +rresvport(alport) + int *alport; +{ + struct sockaddr_in sin; + int s; + + 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; + u_long addr; + char **ap; + + if ((hp = gethostbyname(rhost)) == NULL) + return (-1); + for (ap = hp->h_addr_list; *ap; ++ap) { + bcopy(*ap, &addr, sizeof(addr)); + if (iruserok(addr, 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; + + 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)) { + char *pbuf; + size_t dirlen; + + first = 0; + if ((pwd = getpwnam(luser)) == NULL) + return (-1); + + dirlen = strlen (pwd->pw_dir); + pbuf = alloca (dirlen + sizeof "/.rhosts"); + memcpy (pbuf, pwd->pw_dir, dirlen); + memcpy (pbuf + dirlen, "/.rhosts", sizeof "/.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; + } + 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 = NULL; + size_t bufsize = 0; + ssize_t nread; + + while ((nread = getline (&buf, &bufsize, hostf)) > 0) { + buf[bufsize - 1] = '\0'; /* Make sure it's terminated. */ + p = buf; + 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 (__icheckhost(raddr, buf) && + strcmp(ruser, *user ? user : luser) == 0) { + free (buf); + return (0); + } + } + free (buf); + return (-1); +} + +/* + * Returns "true" if match, 0 if no match. + */ +static int +__icheckhost(raddr, lhost) + u_long raddr; + register 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); +} |