/* $NetBSD: rcmd.c,v 1.73 2024/01/20 14:52:48 christos Exp $ */ /* * 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. 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. */ #include #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)rcmd.c 8.3 (Berkeley) 3/26/94"; #else __RCSID("$NetBSD: rcmd.c,v 1.73 2024/01/20 14:52:48 christos Exp $"); #endif #endif /* LIBC_SCCS and not lint */ #ifdef _LIBC #include "namespace.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pathnames.h" int orcmd(char **, u_int, const char *, const char *, const char *, int *); int orcmd_af(char **, u_int, const char *, const char *, const char *, int *, int); int __ivaliduser(FILE *, u_int32_t, const char *, const char *); int __ivaliduser_sa(FILE *, const struct sockaddr *, socklen_t, const char *, const char *); static int rshrcmd(int, char **, u_int32_t, const char *, const char *, const char *, int *, const char *); static int resrcmd(struct addrinfo *, char **, u_int32_t, const char *, const char *, const char *, int *); static int __icheckhost(const struct sockaddr *, socklen_t, const char *); static char *__gethostloop(const struct sockaddr *, socklen_t); 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) { static char hbuf[MAXHOSTNAMELEN]; char pbuf[NI_MAXSERV]; struct addrinfo hints, *res; int error; struct servent *sp; _DIAGASSERT(ahost != NULL); _DIAGASSERT(locuser != NULL); _DIAGASSERT(remuser != NULL); _DIAGASSERT(cmd != NULL); /* fd2p may be NULL */ 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) { warnx("%s: %s", *ahost, gai_strerror(error)); /*XXX*/ return -1; } if (res->ai_canonname) { /* * Canonicalise hostname. * XXX: Should we really do this? */ strlcpy(hbuf, res->ai_canonname, sizeof(hbuf)); *ahost = hbuf; } /* * Check if rport is the same as the shell port, and that the fd2p. If * it is not, the program isn't expecting 'rsh' and so we can't use the * RCMD_CMD environment. */ sp = getservbyname("shell", "tcp"); if (sp != NULL && sp->s_port == rport) error = rshrcmd(af, ahost, (u_int32_t)rport, locuser, remuser, cmd, fd2p, getenv("RCMD_CMD")); else error = resrcmd(res, ahost, (u_int32_t)rport, locuser, remuser, cmd, fd2p); freeaddrinfo(res); return error; } /* this is simply a wrapper around hprcmd() that handles ahost first */ int orcmd(char **ahost, u_int rport, const char *locuser, const char *remuser, const char *cmd, int *fd2p) { return orcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET); } int orcmd_af(char **ahost, u_int rport, const char *locuser, const char *remuser, const char *cmd, int *fd2p, int af) { static char hbuf[MAXHOSTNAMELEN]; char pbuf[NI_MAXSERV]; struct addrinfo hints, *res; int error; _DIAGASSERT(ahost != NULL); _DIAGASSERT(locuser != NULL); _DIAGASSERT(remuser != NULL); _DIAGASSERT(cmd != NULL); /* fd2p may be NULL */ 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) { warnx("%s: %s", *ahost, gai_strerror(error)); /*XXX*/ return -1; } if (res->ai_canonname) { strlcpy(hbuf, res->ai_canonname, sizeof(hbuf)); *ahost = hbuf; } error = resrcmd(res, ahost, rport, locuser, remuser, cmd, fd2p); freeaddrinfo(res); return error; } /*ARGSUSED*/ static int resrcmd(struct addrinfo *res, char **ahost, u_int32_t rport, const char *locuser, const char *remuser, const char *cmd, int *fd2p) { struct addrinfo *r; struct sockaddr_storage from; struct pollfd reads[2]; sigset_t nmask, omask; pid_t pid; int s, lport, timo; int pollr; char c; int refused; _DIAGASSERT(res != NULL); _DIAGASSERT(ahost != NULL); _DIAGASSERT(locuser != NULL); _DIAGASSERT(remuser != NULL); _DIAGASSERT(cmd != NULL); /* fd2p may be NULL */ r = res; refused = 0; pid = getpid(); sigemptyset(&nmask); sigaddset(&nmask, SIGURG); if (sigprocmask(SIG_BLOCK, &nmask, &omask) == -1) return -1; for (timo = 1, lport = IPPORT_RESERVED - 1;;) { s = rresvport_af(&lport, r->ai_family); if (s < 0) { if (errno == EAGAIN) warnx("rcmd: socket: All ports in use"); else warn("rcmd: socket"); if (r->ai_next) { r = r->ai_next; continue; } else { (void)sigprocmask(SIG_SETMASK, &omask, NULL); return -1; } } fcntl(s, F_SETOWN, pid); if (connect(s, r->ai_addr, r->ai_addrlen) >= 0) break; (void)close(s); if (errno == EADDRINUSE) { lport--; continue; } else if (errno == ECONNREFUSED) refused++; if (r->ai_next) { int oerrno = errno; char hbuf[NI_MAXHOST]; const int niflags = NI_NUMERICHOST; hbuf[0] = '\0'; if (getnameinfo(r->ai_addr, r->ai_addrlen, hbuf, (socklen_t)sizeof(hbuf), NULL, 0, niflags) != 0) strlcpy(hbuf, "(invalid)", sizeof(hbuf)); errno = oerrno; warn("rcmd: connect to address %s", hbuf); r = r->ai_next; hbuf[0] = '\0'; if (getnameinfo(r->ai_addr, r->ai_addrlen, hbuf, (socklen_t)sizeof(hbuf), NULL, 0, niflags) != 0) strlcpy(hbuf, "(invalid)", sizeof(hbuf)); (void)fprintf(stderr, "Trying %s...\n", hbuf); continue; } if (refused && timo <= 16) { (void)sleep((unsigned int)timo); timo *= 2; r = res; refused = 0; continue; } (void)fprintf(stderr, "%s: %s\n", res->ai_canonname, strerror(errno)); (void)sigprocmask(SIG_SETMASK, &omask, NULL); return -1; } lport--; if (fd2p == 0) { write(s, "", 1); lport = 0; } else { char num[8]; int s2 = rresvport_af(&lport, r->ai_family), s3; socklen_t 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) != (ssize_t) (strlen(num) + 1)) { warn("rcmd: write (setting up stderr)"); (void)close(s2); goto bad; } reads[0].fd = s; reads[0].events = POLLIN; reads[1].fd = s2; reads[1].events = POLLIN; errno = 0; pollr = poll(reads, 2, INFTIM); if (pollr < 1 || (reads[1].revents & POLLIN) == 0) { if (errno != 0) warn("poll: setting up stderr"); else warnx( "poll: protocol failure in circuit setup"); (void)close(s2); goto bad; } s3 = accept(s2, (struct sockaddr *)(void *)&from, &len); (void)close(s2); if (s3 < 0) { warn("rcmd: accept"); lport = 0; goto bad; } *fd2p = s3; switch (((struct sockaddr *)(void *)&from)->sa_family) { case AF_INET: #ifdef INET6 case AF_INET6: #endif if (getnameinfo((struct sockaddr *)(void *)&from, len, NULL, 0, num, (socklen_t)sizeof(num), NI_NUMERICSERV) != 0 || (atoi(num) >= IPPORT_RESERVED || atoi(num) < IPPORT_RESERVED / 2)) { warnx( "rcmd: protocol failure in circuit setup."); goto bad2; } break; default: break; } } (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) { warn("%s", *ahost); goto bad2; } if (c != 0) { while (read(s, &c, 1) == 1) { (void)write(STDERR_FILENO, &c, 1); if (c == '\n') break; } goto bad2; } (void)sigprocmask(SIG_SETMASK, &omask, NULL); return s; bad2: if (lport) (void)close(*fd2p); bad: (void)close(s); (void)sigprocmask(SIG_SETMASK, &omask, NULL); return -1; } /* * based on code written by Chris Siebenmann */ /* ARGSUSED */ static int rshrcmd(int af, char **ahost, u_int32_t rport, const char *locuser, const char *remuser, const char *cmd, int *fd2p, const char *rshcmd) { pid_t pid; int sp[2], ep[2]; const char *p; struct passwd *pw, pwres; char pwbuf[1024]; _DIAGASSERT(ahost != NULL); _DIAGASSERT(locuser != NULL); _DIAGASSERT(remuser != NULL); _DIAGASSERT(cmd != NULL); /* fd2p may be NULL */ /* What rsh/shell to use. */ if (rshcmd == NULL) rshcmd = _PATH_BIN_RCMD; /* locuser must exist on this host. */ if (getpwnam_r(locuser, &pwres, pwbuf, sizeof(pwbuf), &pw) != 0 || pw == NULL) { warnx("%s: unknown user: %s", __func__, locuser); return -1; } /* get a socketpair we'll use for stdin and stdout. */ if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sp) < 0) { warn("%s: socketpair", __func__); return -1; } /* we will use this for the fd2 pointer */ if (fd2p) { if (socketpair(AF_LOCAL, SOCK_STREAM, 0, ep) < 0) { warn("%s: socketpair", __func__); return -1; } *fd2p = ep[0]; } pid = fork(); if (pid < 0) { warn("%s: fork", __func__); return -1; } if (pid == 0) { /* * child * - we use sp[1] to be stdin/stdout, and close sp[0] * - with fd2p, we use ep[1] for stderr, and close ep[0] */ (void)close(sp[0]); if (dup2(sp[1], 0) < 0 || dup2(0, 1) < 0) { warn("%s: dup2", __func__); _exit(1); } (void)close(sp[1]); if (fd2p) { if (dup2(ep[1], 2) < 0) { warn("%s: dup2", __func__); _exit(1); } (void)close(ep[0]); (void)close(ep[1]); } else if (dup2(0, 2) < 0) { warn("%s: dup2", __func__); _exit(1); } /* fork again to lose parent. */ pid = fork(); if (pid < 0) { warn("%s: second fork", __func__); _exit(1); } if (pid > 0) _exit(0); /* Orphan. Become local user for rshprog. */ if (setuid(pw->pw_uid)) { warn("%s: setuid(%lu)", __func__, (u_long)pw->pw_uid); _exit(1); } /* * If we are rcmd'ing to "localhost" as the same user as we * are, then avoid running remote shell for efficiency. */ if (strcmp(*ahost, "localhost") == 0 && strcmp(locuser, remuser) == 0) { if (pw->pw_shell[0] == '\0') rshcmd = _PATH_BSHELL; else rshcmd = pw->pw_shell; p = strrchr(rshcmd, '/'); execlp(rshcmd, p ? p + 1 : rshcmd, "-c", cmd, NULL); } else { const char *program; program = strrchr(rshcmd, '/'); program = program ? program + 1 : rshcmd; if (fd2p) /* ask rcmd to relay signal information */ setenv("RCMD_RELAY_SIGNAL", "YES", 1); switch (af) { case AF_INET: execlp(rshcmd, program, "-4", "-l", remuser, *ahost, cmd, NULL); break; case AF_INET6: execlp(rshcmd, program, "-6", "-l", remuser, *ahost, cmd, NULL); break; default: /* typically AF_UNSPEC, plus whatever */ execlp(rshcmd, program, "-l", remuser, *ahost, cmd, NULL); break; } } warn("%s: exec %s", __func__, rshcmd); _exit(1); } /* Parent */ (void)close(sp[1]); if (fd2p) (void)close(ep[1]); (void)waitpid(pid, NULL, 0); return sp[0]; } int rresvport(int *alport) { _DIAGASSERT(alport != NULL); return rresvport_af(alport, AF_INET); } int rresvport_af(int *alport, int family) { return rresvport_af_addr(alport, family, NULL); } int rresvport_af_addr(int *alport, int family, void *addr) { struct sockaddr_storage ss; struct sockaddr *sa; socklen_t salen; int s; u_int16_t *portp; _DIAGASSERT(alport != NULL); memset(&ss, 0, sizeof(ss)); sa = (struct sockaddr *)(void *)&ss; switch (family) { case AF_INET: #ifdef BSD4_4 sa->sa_len = #endif salen = sizeof(struct sockaddr_in); if (addr) ((struct sockaddr_in *)(void *)sa)->sin_addr = ((struct sockaddr_in *)addr)->sin_addr; portp = &((struct sockaddr_in *)(void *)sa)->sin_port; break; #ifdef INET6 case AF_INET6: #ifdef BSD4_4 sa->sa_len = #endif salen = sizeof(struct sockaddr_in6); if (addr) ((struct sockaddr_in6 *)(void *)sa)->sin6_addr = ((struct sockaddr_in6 *)addr)->sin6_addr; portp = &((struct sockaddr_in6 *)(void *)sa)->sin6_port; break; #endif default: errno = EAFNOSUPPORT; return -1; } sa->sa_family = family; s = socket(family, SOCK_STREAM, 0); if (s < 0) return -1; #ifdef BSD4_4 switch (family) { case AF_INET: case AF_INET6: *portp = 0; if (bindresvport(s, (struct sockaddr_in *)(void *)sa) < 0) { int sverr = errno; (void)close(s); errno = sverr; return -1; } *alport = (int)ntohs(*portp); return s; default: /* is it necessary to try keep code for other AFs? */ break; } #endif for (;;) { *portp = htons((u_short)*alport); if (bind(s, sa, salen) >= 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; const char *__rcmd_errstr; int ruserok(const char *rhost, int superuser, const char *ruser, const char *luser) { struct addrinfo hints, *res, *r; int error; _DIAGASSERT(rhost != NULL); _DIAGASSERT(ruser != NULL); _DIAGASSERT(luser != NULL); 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, (int)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(u_int32_t raddr, int superuser, const char *ruser, const char *luser) { struct sockaddr_in irsin; memset(&irsin, 0, sizeof(irsin)); irsin.sin_family = AF_INET; #ifdef BSD4_4 irsin.sin_len = sizeof(irsin); #endif memcpy(&irsin.sin_addr, &raddr, sizeof(irsin.sin_addr)); return iruserok_sa(&irsin, (socklen_t)sizeof(irsin), superuser, ruser, luser); } /* * 2nd and 3rd arguments are typed like this, to avoid dependency between * unistd.h and sys/socket.h. There's no better way. */ int iruserok_sa(const void *raddr, int rlen, int superuser, const char *ruser, const char *luser) { const struct sockaddr *sa; struct stat sbuf; struct passwd *pwd, pwres; FILE *hostf; uid_t uid; gid_t gid; int isvaliduser; char pbuf[MAXPATHLEN]; char pwbuf[1024]; _DIAGASSERT(raddr != NULL); _DIAGASSERT(ruser != NULL); _DIAGASSERT(luser != NULL); sa = raddr; __rcmd_errstr = NULL; hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "re"); if (hostf) { if (__ivaliduser_sa(hostf, sa, (socklen_t)rlen, luser, ruser) == 0) { (void)fclose(hostf); return 0; } (void)fclose(hostf); } isvaliduser = -1; if (__check_rhosts_file || superuser) { if (getpwnam_r(luser, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 || pwd == NULL) return -1; (void)strlcpy(pbuf, pwd->pw_dir, sizeof(pbuf)); (void)strlcat(pbuf, "/.rhosts", sizeof(pbuf)); /* * Change effective uid while opening and reading .rhosts. * If root and reading an NFS mounted file system, can't * read files that are protected read/write owner only. */ uid = geteuid(); gid = getegid(); (void)setegid(pwd->pw_gid); (void)initgroups(pwd->pw_name, pwd->pw_gid); (void)seteuid(pwd->pw_uid); hostf = fopen(pbuf, "re"); if (hostf != NULL) { /* * If not a regular file, or is owned by someone other * than user or root or if writable by anyone but the * owner, quit. */ if (lstat(pbuf, &sbuf) < 0) __rcmd_errstr = ".rhosts lstat failed"; else if (!S_ISREG(sbuf.st_mode)) __rcmd_errstr = ".rhosts not regular file"; else if (fstat(fileno(hostf), &sbuf) < 0) __rcmd_errstr = ".rhosts fstat failed"; else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) __rcmd_errstr = "bad .rhosts owner"; else if (sbuf.st_mode & (S_IWGRP|S_IWOTH)) __rcmd_errstr = ".rhosts writable by other than owner"; else isvaliduser = __ivaliduser_sa(hostf, sa, (socklen_t)rlen, luser, ruser); (void)fclose(hostf); } (void)seteuid(uid); (void)setegid(gid); } return isvaliduser; } /* * XXX * Don't make static, used by lpd(8). We will be able to change the function * into static function, when we bump libc major #. * * Returns 0 if ok, -1 if not ok. */ #ifdef notdef /*_LIBC*/ static #endif int __ivaliduser(FILE *hostf, u_int32_t raddr, const char *luser, const char *ruser) { struct sockaddr_in ivusin; memset(&ivusin, 0, sizeof(ivusin)); ivusin.sin_family = AF_INET; #ifdef BSD4_4 ivusin.sin_len = sizeof(ivusin); #endif memcpy(&ivusin.sin_addr, &raddr, sizeof(ivusin.sin_addr)); return __ivaliduser_sa(hostf, (struct sockaddr *)(void *)&ivusin, (socklen_t)sizeof(ivusin), luser, ruser); } #ifdef notdef /*_LIBC*/ static #endif 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 */ const char *auser, *ahost; int hostok, userok; char *rhost = NULL; int firsttime = 1; char domain[MAXHOSTNAMELEN]; getdomainname(domain, sizeof(domain)); _DIAGASSERT(hostf != NULL); _DIAGASSERT(luser != NULL); _DIAGASSERT(ruser != NULL); while (fgets(buf, (int)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((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'; if (p == buf) continue; auser = *user ? user : luser; ahost = buf; if (ahost[0] == '+') switch (ahost[1]) { case '\0': hostok = 1; break; case '@': if (firsttime) { rhost = __gethostloop(raddr, salen); firsttime = 0; } if (rhost) hostok = innetgr(&ahost[2], rhost, NULL, domain); else hostok = 0; break; default: hostok = __icheckhost(raddr, salen, &ahost[1]); break; } else if (ahost[0] == '-') switch (ahost[1]) { case '\0': hostok = -1; break; case '@': if (firsttime) { rhost = __gethostloop(raddr, salen); firsttime = 0; } if (rhost) hostok = -innetgr(&ahost[2], rhost, NULL, domain); else hostok = 0; break; default: hostok = -__icheckhost(raddr, salen, &ahost[1]); break; } else hostok = __icheckhost(raddr, salen, 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 ? 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(const struct sockaddr *raddr, socklen_t salen, const char *lhost) { struct addrinfo hints, *res, *r; char h1[NI_MAXHOST], h2[NI_MAXHOST]; int error; const int niflags = NI_NUMERICHOST; _DIAGASSERT(raddr != NULL); _DIAGASSERT(lhost != NULL); h1[0] = '\0'; if (getnameinfo(raddr, salen, h1, (socklen_t)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, (socklen_t)sizeof(h2), NULL, 0, niflags) != 0) continue; if (strcmp(h1, h2) == 0) { freeaddrinfo(res); return 1; } } /* No match. */ freeaddrinfo(res); return 0; } /* * Return the hostname associated with the supplied address. * Do a reverse lookup as well for security. If a loop cannot * be found, pack the numeric IP address into the string. */ static char * __gethostloop(const struct sockaddr *raddr, socklen_t salen) { static char remotehost[NI_MAXHOST]; char h1[NI_MAXHOST], h2[NI_MAXHOST]; struct addrinfo hints, *res, *r; int error; const int niflags = NI_NUMERICHOST; _DIAGASSERT(raddr != NULL); h1[0] = remotehost[0] = '\0'; if (getnameinfo(raddr, salen, remotehost, (socklen_t)sizeof(remotehost), NULL, 0, NI_NAMEREQD) != 0) return NULL; if (getnameinfo(raddr, salen, h1, (socklen_t)sizeof(h1), NULL, 0, niflags) != 0) return NULL; /* * Look up the name and check that the supplied * address is in the list */ 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 (r = res; r; r = r->ai_next) { h2[0] = '\0'; if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, (socklen_t)sizeof(h2), NULL, 0, niflags) != 0) continue; if (strcmp(h1, h2) == 0) { freeaddrinfo(res); return remotehost; } } /* * either the DNS administrator has made a configuration * mistake, or someone has attempted to spoof us */ syslog(LOG_NOTICE, "rcmd: address %s not listed for host %s", h1, res->ai_canonname ? res->ai_canonname : remotehost); freeaddrinfo(res); return NULL; }