/* $OpenBSD: getgrouplist.c,v 1.28 2019/07/02 15:54:05 deraadt Exp $ */ /* * Copyright (c) 2008 Ingo Schwarze * Copyright (c) 1991, 1993 * 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. */ /* * get credential */ #include #include #include #include #include #include #include #include #include #include #include #include #ifdef YP #define _PATH_NETID "/etc/netid" #define MAXLINELENGTH 1024 static int _parse_netid(char*, uid_t, gid_t*, int*, int); static int _read_netid(const char *, uid_t, gid_t*, int*, int); /* * Parse one string of the form "uid:gid[,gid[,...]]". * If the uid matches, add the groups to the group list. * If the groups fit, return 1, otherwise return -1. * If the uid does not match, return 0. */ static int _parse_netid(char *netid, uid_t uid, gid_t *groups, int *ngroups, int maxgroups) { const char *errstr = NULL; char *start, *p; uid_t tuid; gid_t gid; int i; /* Check the uid. */ p = strchr(netid, ':'); if (!p) return (0); *p++ = '\0'; tuid = (uid_t)strtonum(netid, 0, UID_MAX, &errstr); if (errstr || tuid != uid) return (0); /* Loop over the gids. */ while (p && *p) { start = p; p = strchr(start, ','); if (p) *p++ = '\0'; gid = (gid_t)strtonum(start, 0, GID_MAX, &errstr); if (errstr) continue; /* Skip this group if it is already in the list. */ for (i = 0; i < *ngroups; i++) if (groups[i] == gid) break; /* Try to add this new group to the list. */ if (i == *ngroups) { if (*ngroups >= maxgroups) return (-1); groups[(*ngroups)++] = gid; } } return (1); } /* * Search /etc/netid for a particular uid and process that line. * See _parse_netid for details, including return values. */ static int _read_netid(const char *key, uid_t uid, gid_t *groups, int *ngroups, int maxgroups) { FILE *fp; char line[MAXLINELENGTH], *p; int found = 0; fp = fopen(_PATH_NETID, "re"); if (!fp) return (0); while (!found && fgets(line, sizeof(line), fp)) { p = strchr(line, '\n'); if (p) *p = '\0'; else { /* Skip lines that are too long. */ int ch; while ((ch = getc_unlocked(fp)) != '\n' && ch != EOF) ; continue; } p = strchr(line, ' '); if (!p) continue; *p++ = '\0'; if (strcmp(line, key)) continue; found = _parse_netid(p, uid, groups, ngroups, maxgroups); } (void)fclose(fp); return (found); } #endif /* YP */ int getgrouplist(const char *uname, gid_t agroup, gid_t *groups, int *grpcnt) { int i, ngroups = 0, ret = 0, maxgroups = *grpcnt, bail; int needyp = 0, foundyp = 0; int *skipyp = &foundyp; extern struct group *_getgrent_yp(int *); struct group *grp; #ifdef YP int saved_errno; #endif /* * install primary group */ if (ngroups >= maxgroups) { *grpcnt = ngroups; return (-1); } groups[ngroups++] = agroup; #ifdef YP /* * Hint to the kernel that a passwd database operation is happening. */ saved_errno = errno; (void)access("/var/run/ypbind.lock", R_OK); errno = saved_errno; #endif /* * Scan the group file to find additional groups. */ setgrent(); while ((grp = _getgrent_yp(skipyp)) || foundyp) { if (foundyp) { if (foundyp > 0) needyp = 1; else skipyp = NULL; foundyp = 0; continue; } if (grp->gr_gid == agroup) continue; for (bail = 0, i = 0; bail == 0 && i < ngroups; i++) if (groups[i] == grp->gr_gid) bail = 1; if (bail) continue; for (i = 0; grp->gr_mem[i]; i++) { if (!strcmp(grp->gr_mem[i], uname)) { if (ngroups >= maxgroups) { ret = -1; goto out; } groups[ngroups++] = grp->gr_gid; break; } } } #ifdef YP /* * If we were told that there is a YP marker, look at netid data. */ if (skipyp && needyp) { char buf[MAXLINELENGTH], *ypdata = NULL, *key; static char *__ypdomain; struct passwd pwstore; int ypdatalen; /* Construct the netid key to look up. */ if (getpwnam_r(uname, &pwstore, buf, sizeof buf, NULL) || (!__ypdomain && yp_get_default_domain(&__ypdomain))) goto out; i = asprintf(&key, "unix.%u@%s", pwstore.pw_uid, __ypdomain); if (i == -1) goto out; /* First scan the static netid file. */ switch (_read_netid(key, pwstore.pw_uid, groups, &ngroups, maxgroups)) { case -1: ret = -1; /* FALLTHROUGH */ case 1: free(key); goto out; default: break; } /* Only access YP when there is no static entry. */ if (!yp_bind(__ypdomain) && !yp_match(__ypdomain, "netid.byname", key, (int)strlen(key), &ypdata, &ypdatalen)) if (_parse_netid(ypdata, pwstore.pw_uid, groups, &ngroups, maxgroups) == -1) ret = -1; free(key); free(ypdata); } #endif /* YP */ out: endgrent(); *grpcnt = ngroups; return (ret); } DEF_WEAK(getgrouplist);