/* * Copyright (c) 1995, 1996 * Bill Paul . 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 Bill Paul. * 4. Neither the name of the author nor the names of any co-contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY Bill Paul 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 Bill Paul 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. * * $Id: yppasswdd_server.c,v 1.7 1996/08/04 22:13:05 wpaul Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct dom_binding {}; #include #include "yppasswdd_extern.h" #include "yppasswd.h" #include "yppasswd_private.h" #include "yppasswd_comm.h" #ifndef lint static const char rcsid[] = "$Id: yppasswdd_server.c,v 1.7 1996/08/04 22:13:05 wpaul Exp $"; #endif /* not lint */ char *tempname; void reaper(sig) int sig; { extern pid_t pid; extern int pstat; int st; if (sig > 0) { if (sig == SIGCHLD) while(wait3(&st, WNOHANG, NULL) > 0) ; } else { pid = waitpid(pid, &pstat, 0); } return; } void install_reaper(on) int on; { if (on) { signal(SIGCHLD, reaper); } else { signal(SIGCHLD, SIG_DFL); } return; } static struct passwd yp_password; static void copy_yp_pass(p, x, m) char *p; int x, m; { register char *t, *s = p; static char *buf; yp_password.pw_fields = 0; buf = (char *)realloc(buf, m + 10); bzero(buf, m + 10); /* Turn all colons into NULLs */ while (strchr(s, ':')) { s = (strchr(s, ':') + 1); *(s - 1)= '\0'; } t = buf; #define EXPAND(e) e = t; while ((*t++ = *p++)); EXPAND(yp_password.pw_name); yp_password.pw_fields |= _PWF_NAME; EXPAND(yp_password.pw_passwd); yp_password.pw_fields |= _PWF_PASSWD; yp_password.pw_uid = atoi(p); p += (strlen(p) + 1); yp_password.pw_fields |= _PWF_UID; yp_password.pw_gid = atoi(p); p += (strlen(p) + 1); yp_password.pw_fields |= _PWF_GID; if (x) { EXPAND(yp_password.pw_class); yp_password.pw_fields |= _PWF_CLASS; yp_password.pw_change = atol(p); p += (strlen(p) + 1); yp_password.pw_fields |= _PWF_CHANGE; yp_password.pw_expire = atol(p); p += (strlen(p) + 1); yp_password.pw_fields |= _PWF_EXPIRE; } EXPAND(yp_password.pw_gecos); yp_password.pw_fields |= _PWF_GECOS; EXPAND(yp_password.pw_dir); yp_password.pw_fields |= _PWF_DIR; EXPAND(yp_password.pw_shell); yp_password.pw_fields |= _PWF_SHELL; return; } static int validchars(arg) char *arg; { int i; for (i = 0; i < strlen(arg); i++) { if (iscntrl(arg[i])) { yp_error("string contains a control character"); return(1); } if (arg[i] == ':') { yp_error("string contains a colon"); return(1); } /* Be evil: truncate strings with \n in them silently. */ if (arg[i] == '\n') { arg[i] = '\0'; return(0); } } return(0); } static int validate_master(opw, npw) struct passwd *opw; struct x_master_passwd *npw; { if (npw->pw_name[0] == '+' || npw->pw_name[0] == '-') { yp_error("client tried to modify an NIS entry"); return(1); } if (validchars(npw->pw_shell)) { yp_error("specified shell contains invalid characters"); return(1); } if (validchars(npw->pw_gecos)) { yp_error("specified gecos field contains invalid characters"); return(1); } if (validchars(npw->pw_passwd)) { yp_error("specified password contains invalid characters"); return(1); } return(0); } static int validate(opw, npw) struct passwd *opw; struct x_passwd *npw; { if (npw->pw_name[0] == '+' || npw->pw_name[0] == '-') { yp_error("client tried to modify an NIS entry"); return(1); } if (npw->pw_uid != opw->pw_uid) { yp_error("UID mismatch: client says user %s has UID %d", npw->pw_name, npw->pw_uid); yp_error("database says user %s has UID %d", opw->pw_name, opw->pw_uid); return(1); } if (npw->pw_gid != opw->pw_gid) { yp_error("GID mismatch: client says user %s has GID %d", npw->pw_name, npw->pw_gid); yp_error("database says user %s has GID %d", opw->pw_name, opw->pw_gid); return(1); } /* * Don't allow the user to shoot himself in the foot, * even on purpose. */ if (!ok_shell(npw->pw_shell)) { yp_error("%s is not a valid shell", npw->pw_shell); return(1); } if (validchars(npw->pw_shell)) { yp_error("specified shell contains invalid characters"); return(1); } if (validchars(npw->pw_gecos)) { yp_error("specified gecos field contains invalid characters"); return(1); } if (validchars(npw->pw_passwd)) { yp_error("specified password contains invalid characters"); return(1); } return(0); } /* * Kludge alert: * In order to have one rpc.yppasswdd support multiple domains, * we have to cheat: we search each directory under /var/yp * and try to match the user in each master.passwd.byname * map that we find. If the user matches (username, uid and gid * all agree), then we use that domain. If we match the user in * more than one database, we must abort. */ static char *find_domain(pw) struct x_passwd *pw; { struct stat statbuf; struct dirent *dirp; DIR *dird; char yp_mapdir[MAXPATHLEN + 2]; static char domain[YPMAXDOMAIN]; char *tmp = NULL; DBT key, data; int hit = 0; yp_error("performing multidomain lookup"); if ((dird = opendir(yp_dir)) == NULL) { yp_error("opendir(%s) failed: %s", yp_dir, strerror(errno)); return(NULL); } while ((dirp = readdir(dird)) != NULL) { snprintf(yp_mapdir, sizeof(yp_mapdir), "%s/%s", yp_dir, dirp->d_name); if (stat(yp_mapdir, &statbuf) < 0) { yp_error("stat(%s) failed: %s", yp_mapdir, strerror(errno)); closedir(dird); return(NULL); } if (S_ISDIR(statbuf.st_mode)) { tmp = (char *)dirp->d_name; key.data = pw->pw_name; key.size = strlen(pw->pw_name); if (yp_get_record(tmp,"master.passwd.byname", &key, &data, 0) != YP_TRUE) { continue; } *(char *)(data.data + data.size) = '\0'; copy_yp_pass(data.data, 1, data.size); if (yp_password.pw_uid == pw->pw_uid && yp_password.pw_gid == pw->pw_gid) { hit++; snprintf(domain, YPMAXDOMAIN, "%s", tmp); } } } closedir(dird); if (hit > 1) { yp_error("found same user in two different domains"); return(NULL); } else return((char *)&domain); } static int update_inplace(pw, domain) struct passwd *pw; char *domain; { DB *dbp = NULL; DBT key = { NULL, 0 }; DBT data = { NULL, 0 }; char pwbuf[YPMAXRECORD]; char keybuf[20]; int rval, i; char *maps[] = { "master.passwd.byname", "master.passwd.byuid", "passwd.byname", "passwd.byuid" }; char *formats[] = { "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s", "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s", "%s:%s:%d:%d:%s:%s:%s", "%s:%s:%d:%d:%s:%s:%s" }; char *ptr = NULL; char *yp_last = "YP_LAST_MODIFIED"; char yplastbuf[YPMAXRECORD]; snprintf(yplastbuf, sizeof(yplastbuf), "%lu", time(NULL)); for (i = 0; i < 4; i++) { if (i % 2) { snprintf(keybuf, sizeof(keybuf), "%ld", pw->pw_uid); key.data = (char *)&keybuf; key.size = strlen(keybuf); } else { key.data = pw->pw_name; key.size = strlen(pw->pw_name); } /* * XXX The passwd.byname and passwd.byuid maps come in * two flavors: secure and insecure. The secure version * has a '*' in the password field whereas the insecure one * has a real crypted password. The maps will be insecure * if they were built with 'unsecure = TRUE' enabled in * /var/yp/Makefile, but we'd have no way of knowing if * this has been done unless we were to try parsing the * Makefile, which is a disgusting thought. Instead, we * read the records from the maps, skip to the first ':' * in them, and then look at the character immediately * following it. If it's an '*' then the map is 'secure' * and we must not insert a real password into the pw_passwd * field. If it's not an '*', then we put the real crypted * password in. */ if (yp_get_record(domain,maps[i],&key,&data,1) != YP_TRUE) { yp_error("couldn't read %s/%s: %s", domain, maps[i], strerror(errno)); return(1); } if ((ptr = strchr(data.data, ':')) == NULL) { yp_error("no colon in passwd record?!"); return(1); } if (i < 2) { snprintf(pwbuf, sizeof(pwbuf), formats[i], pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid, pw->pw_class, pw->pw_change, pw->pw_expire, pw->pw_gecos, pw->pw_dir, pw->pw_shell); } else { snprintf(pwbuf, sizeof(pwbuf), formats[i], pw->pw_name, *(ptr+1) == '*' ? "*" : pw->pw_passwd, pw->pw_uid, pw->pw_gid, pw->pw_gecos, pw->pw_dir, pw->pw_shell); } #define FLAGS O_RDWR|O_CREAT if ((dbp = yp_open_db_rw(domain, maps[i], FLAGS)) == NULL) { yp_error("couldn't open %s/%s r/w: %s",domain, maps[i],strerror(errno)); return(1); } data.data = pwbuf; data.size = strlen(pwbuf); if (yp_put_record(dbp, &key, &data, 1) != YP_TRUE) { yp_error("failed to update record in %s/%s", domain, maps[i]); (void)(dbp->close)(dbp); return(1); } key.data = yp_last; key.size = strlen(yp_last); data.data = (char *)&yplastbuf; data.size = strlen(yplastbuf); if (yp_put_record(dbp, &key, &data, 1) != YP_TRUE) { yp_error("failed to update timestamp in %s/%s", domain, maps[i]); (void)(dbp->close)(dbp); return(1); } (void)(dbp->close)(dbp); } return(0); } static char *yp_mktmpnam() { static char path[MAXPATHLEN]; char *p; sprintf(path,"%s",passfile); if ((p = strrchr(path, '/'))) ++p; else p = path; strcpy(p, "yppwtmp.XXXXXX"); return(mktemp(path)); } int * yppasswdproc_update_1_svc(yppasswd *argp, struct svc_req *rqstp) { static int result; struct sockaddr_in *rqhost; DBT key, data; int rval = 0; int pfd, tfd; int pid; int passwd_changed = 0; int shell_changed = 0; int gecos_changed = 0; char *oldshell = NULL; char *oldgecos = NULL; char *passfile_hold; char passfile_buf[MAXPATHLEN + 2]; char *domain = yppasswd_domain; static struct sockaddr_in clntaddr; static struct timeval t_saved, t_test; /* * Normal user updates always use the 'default' master.passwd file. */ passfile = passfile_default; result = 1; rqhost = svc_getcaller(rqstp->rq_xprt); gettimeofday(&t_test, NULL); if (!bcmp((char *)rqhost, (char *)&clntaddr, sizeof(struct sockaddr_in)) && t_test.tv_sec > t_saved.tv_sec && t_test.tv_sec - t_saved.tv_sec < 300) { bzero((char *)&clntaddr, sizeof(struct sockaddr_in)); bzero((char *)&t_saved, sizeof(struct timeval)); return(NULL); } bcopy((char *)rqhost, (char *)&clntaddr, sizeof(struct sockaddr_in)); gettimeofday(&t_saved, NULL); if (yp_access(resvport ? "master.passwd.byname" : NULL, rqstp)) { yp_error("rejected update request from unauthorized host"); svcerr_auth(rqstp->rq_xprt, AUTH_BADCRED); return(&result); } /* * Step one: find the user. (It's kinda pointless to * proceed if the user doesn't exist.) We look for the * user in the master.passwd.byname database, _NOT_ by * using getpwent() and friends! We can't use getpwent() * since the NIS master server is not guaranteed to be * configured as an NIS client. */ if (multidomain) { if ((domain = find_domain(&argp->newpw)) == NULL) { yp_error("multidomain lookup failed - aborting update"); return(&result); } else yp_error("updating user %s in domain %s", argp->newpw.pw_name, domain); } key.data = argp->newpw.pw_name; key.size = strlen(argp->newpw.pw_name); if ((rval=yp_get_record(domain,"master.passwd.byname", &key, &data, 0)) != YP_TRUE) { if (rval == YP_NOKEY) { yp_error("user %s not found in passwd database", argp->newpw.pw_name); } else { yp_error("database access error: %s", yperr_string(rval)); } return(&result); } /* Nul terminate, please. */ *(char *)(data.data + data.size) = '\0'; copy_yp_pass(data.data, 1, data.size); /* Step 2: check that the supplied oldpass is valid. */ if (strcmp(crypt(argp->oldpass, yp_password.pw_passwd), yp_password.pw_passwd)) { yp_error("rejected change attempt -- bad password"); yp_error("client address: %s username: %s", inet_ntoa(rqhost->sin_addr), argp->newpw.pw_name); return(&result); } /* Step 3: validate the arguments passed to us by the client. */ if (validate(&yp_password, &argp->newpw)) { yp_error("rejecting change attempt: bad arguments"); yp_error("client address: %s username: %s", inet_ntoa(rqhost->sin_addr), argp->newpw.pw_name); svcerr_decode(rqstp->rq_xprt); return(&result); } /* Step 4: update the user's passwd structure. */ if (!no_chsh && strcmp(argp->newpw.pw_shell, yp_password.pw_shell)) { oldshell = yp_password.pw_shell; yp_password.pw_shell = argp->newpw.pw_shell; shell_changed++; } if (!no_chfn && strcmp(argp->newpw.pw_gecos, yp_password.pw_gecos)) { oldgecos = yp_password.pw_gecos; yp_password.pw_gecos = argp->newpw.pw_gecos; gecos_changed++; } if (strcmp(argp->newpw.pw_passwd, yp_password.pw_passwd)) { yp_password.pw_passwd = argp->newpw.pw_passwd; yp_password.pw_change = 0; passwd_changed++; } /* * If the caller specified a domain other than our 'default' * domain, change the path to master.passwd accordingly. */ if (strcmp(domain, yppasswd_domain)) { snprintf(passfile_buf, sizeof(passfile_buf), "%s/%s/master.passwd", yp_dir, domain); passfile = (char *)&passfile_buf; } /* Step 5: make a new password file with the updated info. */ if ((pfd = pw_lock()) < 0) { return (&result); } if ((tfd = pw_tmp()) < 0) { return (&result); } if (pw_copy(pfd, tfd, &yp_password)) { yp_error("failed to created updated password file -- \ cleaning up and bailing out"); unlink(tempname); return(&result); } passfile_hold = yp_mktmpnam(); rename(passfile, passfile_hold); if (strcmp(passfile, _PATH_MASTERPASSWD)) { rename(tempname, passfile); } else { if (pw_mkdb(argp->newpw.pw_name) < 0) { yp_error("pwd_mkdb failed"); return(&result); } } if (inplace) { if ((rval = update_inplace(&yp_password, domain))) { yp_error("inplace update failed -- rebuilding maps"); } } switch((pid = fork())) { case 0: if (inplace && !rval) { execlp(MAP_UPDATE_PATH, MAP_UPDATE, passfile, yppasswd_domain, "pushpw", NULL); } else { execlp(MAP_UPDATE_PATH, MAP_UPDATE, passfile, yppasswd_domain, NULL); } yp_error("couldn't exec map update process: %s", strerror(errno)); unlink(passfile); rename(passfile_hold, passfile); exit(1); break; case -1: yp_error("fork() failed: %s", strerror(errno)); unlink(passfile); rename(passfile_hold, passfile); return(&result); break; default: unlink(passfile_hold); break; } if (verbose) { yp_error("update completed for user %s (uid %d):", argp->newpw.pw_name, argp->newpw.pw_uid); if (passwd_changed) yp_error("password changed"); if (gecos_changed) yp_error("gecos changed ('%s' -> '%s')", oldgecos, argp->newpw.pw_gecos); if (shell_changed) yp_error("shell changed ('%s' -> '%s')", oldshell, argp->newpw.pw_shell); } result = 0; return (&result); } /* * Note that this function performs a little less sanity checking * than the last one. Since only the superuser is allowed to use it, * it is assumed that the caller knows what he's doing. */ static int update_master(master_yppasswd *argp) { int result; int pfd, tfd; int pid; int rval = 0; DBT key, data; char *passfile_hold; char passfile_buf[MAXPATHLEN + 2]; result = 1; passfile = passfile_default; key.data = argp->newpw.pw_name; key.size = strlen(argp->newpw.pw_name); /* * The superuser may add entries to the passwd maps if * rpc.yppasswdd is started with the -a flag. Paranoia * prevents me from allowing additions by default. */ if ((rval = yp_get_record(argp->domain, "master.passwd.byname", &key, &data, 0)) != YP_TRUE) { if (rval == YP_NOKEY) { yp_error("user %s not found in passwd database", argp->newpw.pw_name); if (allow_additions) yp_error("notice: adding user %s to \ master.passwd database for domain %s", argp->newpw.pw_name, argp->domain); else yp_error("restart %s with the -a flag to \ allow additions to be made to the password database", progname); } else { yp_error("database access error: %s", yperr_string(rval)); } if (!allow_additions) return(result); } else { /* Nul terminate, please. */ *(char *)(data.data + data.size) = '\0'; copy_yp_pass(data.data, 1, data.size); } /* * Perform a small bit of sanity checking. */ if (validate_master(rval == YP_TRUE ? &yp_password:NULL,&argp->newpw)){ yp_error("rejecting update attempt for %s: bad arguments", argp->newpw.pw_name); return(result); } /* * If the caller specified a domain other than our 'default' * domain, change the path to master.passwd accordingly. */ if (strcmp(argp->domain, yppasswd_domain)) { snprintf(passfile_buf, sizeof(passfile_buf), "%s/%s/master.passwd", yp_dir, argp->domain); passfile = (char *)&passfile_buf; } if ((pfd = pw_lock()) < 0) { return (result); } if ((tfd = pw_tmp()) < 0) { return (result); } if (pw_copy(pfd, tfd, (struct passwd *)&argp->newpw)) { yp_error("failed to created updated password file -- \ cleaning up and bailing out"); unlink(tempname); return(result); } passfile_hold = yp_mktmpnam(); rename(passfile, passfile_hold); if (strcmp(passfile, _PATH_MASTERPASSWD)) { rename(tempname, passfile); } else { if (pw_mkdb(argp->newpw.pw_name) < 0) { yp_error("pwd_mkdb failed"); return(result); } } if (inplace) { if ((rval = update_inplace((struct passwd *)&argp->newpw, argp->domain))) { yp_error("inplace update failed -- rebuilding maps"); } } switch((pid = fork())) { case 0: close(yp_sock); if (inplace && !rval) { execlp(MAP_UPDATE_PATH, MAP_UPDATE, passfile, argp->domain, "pushpw", NULL); } else { execlp(MAP_UPDATE_PATH, MAP_UPDATE, passfile, argp->domain, NULL); } yp_error("couldn't exec map update process: %s", strerror(errno)); unlink(passfile); rename(passfile_hold, passfile); exit(1); break; case -1: yp_error("fork() failed: %s", strerror(errno)); unlink(passfile); rename(passfile_hold, passfile); return(result); break; default: unlink(passfile_hold); break; } yp_error("performed update of user %s (uid %d) domain %s", argp->newpw.pw_name, argp->newpw.pw_uid, argp->domain); result = 0; return(result); } /* * Pseudo-dispatcher for private 'superuser-only' update handler. */ void do_master() { struct master_yppasswd *pw; if ((pw = getdat(yp_sock)) == NULL) { return; } yp_error("received update request from superuser on localhost"); sendresp(update_master(pw)); /* Remember to free args. */ xdr_free(xdr_master_yppasswd, (char *)pw); return; }