diff options
Diffstat (limited to 'lib/libc/net/rcmd.c')
| -rw-r--r-- | lib/libc/net/rcmd.c | 733 |
1 files changed, 733 insertions, 0 deletions
diff --git a/lib/libc/net/rcmd.c b/lib/libc/net/rcmd.c new file mode 100644 index 000000000000..7b92f0816261 --- /dev/null +++ b/lib/libc/net/rcmd.c @@ -0,0 +1,733 @@ +/* + * 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. + * 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/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "namespace.h" +#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 <stdlib.h> +#include <unistd.h> +#include <pwd.h> +#include <errno.h> +#include <stdio.h> +#include <ctype.h> +#include <string.h> +#include <rpc/rpc.h> +#ifdef YP +#include <rpcsvc/yp_prot.h> +#include <rpcsvc/ypclnt.h> +#endif +#include <arpa/nameser.h> +#include "un-namespace.h" +#include "libc_private.h" + +extern int innetgr( const char *, const char *, const char *, const char * ); + +#define max(a, b) ((a > b) ? a : b) + +int __ivaliduser(FILE *, u_int32_t, const char *, const char *); +int __ivaliduser_af(FILE *,const void *, const char *, const char *, int, int); +int __ivaliduser_sa(FILE *, const struct sockaddr *, socklen_t, const char *, + const char *); +static int __icheckhost(const struct sockaddr *, socklen_t, const char *); + +char paddr[NI_MAXHOST]; + +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_af(char **ahost, int rport, const char *locuser, const char *remuser, + const char *cmd, int *fd2p, int af) +{ + struct addrinfo hints, *res, *ai; + struct sockaddr_storage from; + fd_set reads; + sigset_t oldmask, newmask; + pid_t pid; + int s, aport, lport, timo, error; + char c, *p; + int refused, nres; + char num[8]; + static char canonnamebuf[MAXDNAME]; /* is it proper here? */ + + /* call rcmdsh() with specified remote shell if appropriate. */ + if (!issetugid() && (p = getenv("RSH"))) { + 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(); + + memset(&hints, 0, sizeof(hints)); + hints.ai_flags = AI_CANONNAME; + hints.ai_family = af; + hints.ai_socktype = SOCK_STREAM; + hints.ai_protocol = 0; + (void)snprintf(num, sizeof(num), "%d", ntohs(rport)); + error = getaddrinfo(*ahost, num, &hints, &res); + if (error) { + fprintf(stderr, "rcmd: getaddrinfo: %s\n", + gai_strerror(error)); + if (error == EAI_SYSTEM) + fprintf(stderr, "rcmd: getaddrinfo: %s\n", + strerror(errno)); + return (-1); + } + + if (res->ai_canonname + && strlen(res->ai_canonname) + 1 < sizeof(canonnamebuf)) { + strncpy(canonnamebuf, res->ai_canonname, sizeof(canonnamebuf)); + *ahost = canonnamebuf; + } + nres = 0; + for (ai = res; ai; ai = ai->ai_next) + nres++; + ai = res; + refused = 0; + sigemptyset(&newmask); + sigaddset(&newmask, SIGURG); + __libc_sigprocmask(SIG_BLOCK, (const sigset_t *)&newmask, &oldmask); + for (timo = 1, lport = IPPORT_RESERVED - 1;;) { + s = rresvport_af(&lport, ai->ai_family); + if (s < 0) { + if (errno != EAGAIN && ai->ai_next) { + ai = ai->ai_next; + continue; + } + if (errno == EAGAIN) + (void)fprintf(stderr, + "rcmd: socket: All ports in use\n"); + else + (void)fprintf(stderr, "rcmd: socket: %s\n", + strerror(errno)); + freeaddrinfo(res); + __libc_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, + NULL); + return (-1); + } + _fcntl(s, F_SETOWN, pid); + if (_connect(s, ai->ai_addr, ai->ai_addrlen) >= 0) + break; + (void)_close(s); + if (errno == EADDRINUSE) { + lport--; + continue; + } + if (errno == ECONNREFUSED) + refused = 1; + if (ai->ai_next == NULL && (!refused || timo > 16)) { + (void)fprintf(stderr, "%s: %s\n", + *ahost, strerror(errno)); + freeaddrinfo(res); + __libc_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, + NULL); + return (-1); + } + if (nres > 1) { + int oerrno = errno; + + getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr, + sizeof(paddr), NULL, 0, NI_NUMERICHOST); + (void)fprintf(stderr, "connect to address %s: ", + paddr); + errno = oerrno; + perror(0); + } + if ((ai = ai->ai_next) == NULL) { + /* refused && timo <= 16 */ + struct timespec time_to_sleep, time_remaining; + + time_to_sleep.tv_sec = timo; + time_to_sleep.tv_nsec = 0; + (void)_nanosleep(&time_to_sleep, &time_remaining); + timo *= 2; + ai = res; + refused = 0; + } + if (nres > 1) { + getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr, + sizeof(paddr), NULL, 0, NI_NUMERICHOST); + fprintf(stderr, "Trying %s...\n", paddr); + } + } + lport--; + if (fd2p == NULL) { + _write(s, "", 1); + lport = 0; + } else { + int s2 = rresvport_af(&lport, ai->ai_family), s3; + socklen_t len = ai->ai_addrlen; + int nfds; + + 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; + } + nfds = max(s, s2)+1; + if(nfds > FD_SETSIZE) { + fprintf(stderr, "rcmd: too many files\n"); + (void)_close(s2); + goto bad; + } +again: + FD_ZERO(&reads); + FD_SET(s, &reads); + FD_SET(s2, &reads); + errno = 0; + if (_select(nfds, &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); + switch (from.ss_family) { + case AF_INET: + aport = ntohs(((struct sockaddr_in *)&from)->sin_port); + break; +#ifdef INET6 + case AF_INET6: + aport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port); + break; +#endif + default: + aport = 0; /* error */ + break; + } + /* + * XXX careful for ftp bounce attacks. If discovered, shut them + * down and check for the real auxiliary channel to connect. + */ + if (aport == 20) { + _close(s3); + goto again; + } + (void)_close(s2); + if (s3 < 0) { + (void)fprintf(stderr, + "rcmd: accept: %s\n", strerror(errno)); + lport = 0; + goto bad; + } + *fd2p = s3; + if (aport >= IPPORT_RESERVED || aport < 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; + } + __libc_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL); + freeaddrinfo(res); + return (s); +bad2: + if (lport) + (void)_close(*fd2p); +bad: + (void)_close(s); + __libc_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL); + freeaddrinfo(res); + return (-1); +} + +int +rresvport(int *port) +{ + return rresvport_af(port, AF_INET); +} + +int +rresvport_af(int *alport, int family) +{ + int s; + struct sockaddr_storage ss; + u_short *sport; + + memset(&ss, 0, sizeof(ss)); + ss.ss_family = family; + switch (family) { + case AF_INET: + ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in); + sport = &((struct sockaddr_in *)&ss)->sin_port; + ((struct sockaddr_in *)&ss)->sin_addr.s_addr = INADDR_ANY; + break; +#ifdef INET6 + case AF_INET6: + ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in6); + sport = &((struct sockaddr_in6 *)&ss)->sin6_port; + ((struct sockaddr_in6 *)&ss)->sin6_addr = in6addr_any; + break; +#endif + default: + errno = EAFNOSUPPORT; + return -1; + } + + s = _socket(ss.ss_family, SOCK_STREAM, 0); + if (s < 0) + return (-1); +#if 0 /* compat_exact_traditional_rresvport_semantics */ + 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); + } +#endif + *sport = 0; + if (bindresvport_sa(s, (struct sockaddr *)&ss) == -1) { + (void)_close(s); + return (-1); + } + *alport = (int)ntohs(*sport); + return (s); +} + +int __check_rhosts_file = 1; +char *__rcmd_errstr; + +int +ruserok(const char *rhost, int superuser, const char *ruser, const char *luser) +{ + 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 (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); +} + +/* + * 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(unsigned long raddr, int superuser, const char *ruser, const char *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((struct sockaddr *)&sin, sin.sin_len, superuser, + ruser, luser); +} + +/* + * AF independent extension of iruserok. + * + * Returns 0 if ok, -1 if not ok. + */ +int +iruserok_sa(const void *ra, int rlen, int superuser, const char *ruser, + const char *luser) +{ + char *cp; + struct stat sbuf; + struct passwd *pwd; + FILE *hostf; + uid_t uid; + int first; + char pbuf[MAXPATHLEN]; + const struct sockaddr *raddr; + struct sockaddr_storage ss; + + /* avoid alignment issue */ + if (rlen > sizeof(ss)) + return(-1); + memcpy(&ss, ra, rlen); + raddr = (struct sockaddr *)&ss; + + first = 1; + hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "re"); +again: + if (hostf) { + if (__ivaliduser_sa(hostf, raddr, rlen, 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, "re"); + (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(FILE *hostf, u_int32_t raddr, const char *luser, const char *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, &raddr, sizeof(sin.sin_addr)); + return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len, + luser, ruser); +} + +/* + * Returns 0 if ok, -1 if not ok. + * + * XXX obsolete API. + */ +int +__ivaliduser_af(FILE *hostf, const void *raddr, const char *luser, + const char *ruser, int af, int len) +{ + struct sockaddr *sa = NULL; + struct sockaddr_in *sin = NULL; +#ifdef INET6 + struct sockaddr_in6 *sin6 = NULL; +#endif + struct sockaddr_storage ss; + + memset(&ss, 0, sizeof(ss)); + switch (af) { + case AF_INET: + if (len != sizeof(sin->sin_addr)) + return -1; + sin = (struct sockaddr_in *)&ss; + sin->sin_family = AF_INET; + sin->sin_len = sizeof(struct sockaddr_in); + memcpy(&sin->sin_addr, raddr, sizeof(sin->sin_addr)); + break; +#ifdef INET6 + case AF_INET6: + if (len != sizeof(sin6->sin6_addr)) + return -1; + /* you will lose scope info */ + sin6 = (struct sockaddr_in6 *)&ss; + sin6->sin6_family = AF_INET6; + sin6->sin6_len = sizeof(struct sockaddr_in6); + memcpy(&sin6->sin6_addr, raddr, sizeof(sin6->sin6_addr)); + break; +#endif + default: + return -1; + } + + sa = (struct sockaddr *)&ss; + return __ivaliduser_sa(hostf, sa, sa->sa_len, luser, ruser); +} + +int +__ivaliduser_sa(FILE *hostf, const struct sockaddr *raddr, socklen_t salen, + const char *luser, const char *ruser) +{ + char *user, *p; + int ch; + char buf[MAXHOSTNAMELEN + 128]; /* host + login */ + char hname[MAXHOSTNAMELEN]; + /* Presumed guilty until proven innocent. */ + int userok = 0, hostok = 0; +#ifdef YP + char *ypdomain; + + if (yp_get_default_domain(&ypdomain)) + ypdomain = NULL; +#else +#define ypdomain NULL +#endif + /* We need to get the damn hostname back for netgroup matching. */ + if (getnameinfo(raddr, salen, hname, sizeof(hname), NULL, 0, + NI_NAMEREQD) != 0) + hname[0] = '\0'; + + 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; + } + if (*p == '\n' || *p == '#') { + /* comment... */ + continue; + } + while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { + *p = isupper((unsigned char)*p) ? tolower((unsigned char)*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'; + /* + * Do +/- and +@/-@ checking. This looks really nasty, + * but it matches SunOS's behavior so far as I can tell. + */ + switch(buf[0]) { + case '+': + if (!buf[1]) { /* '+' matches all hosts */ + hostok = 1; + break; + } + if (buf[1] == '@') /* match a host by netgroup */ + hostok = hname[0] != '\0' && + innetgr(&buf[2], hname, NULL, ypdomain); + else /* match a host by addr */ + hostok = __icheckhost(raddr, salen, + (char *)&buf[1]); + break; + case '-': /* reject '-' hosts and all their users */ + if (buf[1] == '@') { + if (hname[0] == '\0' || + innetgr(&buf[2], hname, NULL, ypdomain)) + return(-1); + } else { + if (__icheckhost(raddr, salen, + (char *)&buf[1])) + return(-1); + } + break; + default: /* if no '+' or '-', do a simple match */ + hostok = __icheckhost(raddr, salen, buf); + break; + } + switch(*user) { + case '+': + if (!*(user+1)) { /* '+' matches all users */ + userok = 1; + break; + } + if (*(user+1) == '@') /* match a user by netgroup */ + userok = innetgr(user+2, NULL, ruser, ypdomain); + else /* match a user by direct specification */ + userok = !(strcmp(ruser, user+1)); + break; + case '-': /* if we matched a hostname, */ + if (hostok) { /* check for user field rejections */ + if (!*(user+1)) + return(-1); + if (*(user+1) == '@') { + if (innetgr(user+2, NULL, + ruser, ypdomain)) + return(-1); + } else { + if (!strcmp(ruser, user+1)) + return(-1); + } + } + break; + default: /* no rejections: try to match the user */ + if (hostok) + userok = !(strcmp(ruser,*user ? user : luser)); + break; + } + if (hostok && userok) + return(0); + } + return (-1); +} + +/* + * Returns "true" if match, 0 if no match. + */ +static int +__icheckhost(const struct sockaddr *raddr, socklen_t salen, const char *lhost) +{ + struct sockaddr_in sin; + struct sockaddr_in6 *sin6; + struct addrinfo hints, *res, *r; + int error; + char h1[NI_MAXHOST], h2[NI_MAXHOST]; + + if (raddr->sa_family == AF_INET6) { + sin6 = (struct sockaddr_in6 *)raddr; + if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) { + memset(&sin, 0, sizeof(sin)); + sin.sin_family = AF_INET; + sin.sin_len = sizeof(struct sockaddr_in); + memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12], + sizeof(sin.sin_addr)); + raddr = (struct sockaddr *)&sin; + salen = sin.sin_len; + } + } + + h1[0] = '\0'; + if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0, + NI_NUMERICHOST) != 0) + return (0); + + /* Resolve laddr into sockaddr */ + memset(&hints, 0, sizeof(hints)); + hints.ai_family = raddr->sa_family; + hints.ai_socktype = SOCK_DGRAM; /*XXX dummy*/ + res = NULL; + error = getaddrinfo(lhost, "0", &hints, &res); + if (error) + return (0); + + for (r = res; r ; r = r->ai_next) { + h2[0] = '\0'; + if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2), + NULL, 0, NI_NUMERICHOST) != 0) + continue; + if (strcmp(h1, h2) == 0) { + freeaddrinfo(res); + return (1); + } + } + + /* No match. */ + freeaddrinfo(res); + return (0); +} |