/* * Copyright (c) 1996, 1998-2005, 2007 * Todd C. Miller * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * Sponsored in part by the Defense Advanced Research Projects * Agency (DARPA) and Air Force Research Laboratory, Air Force * Materiel Command, USAF, under agreement number F39502-99-1-0512. */ #include #include #include #include #include #include #ifdef STDC_HEADERS # include # include #else # ifdef HAVE_STDLIB_H # include # endif #endif /* STDC_HEADERS */ #ifdef HAVE_STRING_H # include #else # ifdef HAVE_STRINGS_H # include # endif #endif /* HAVE_STRING_H */ #ifdef HAVE_UNISTD_H # include #endif /* HAVE_UNISTD_H */ #ifdef HAVE_FNMATCH # include #endif /* HAVE_FNMATCH */ #ifdef HAVE_EXTENDED_GLOB # include #endif /* HAVE_EXTENDED_GLOB */ #ifdef HAVE_NETGROUP_H # include #endif /* HAVE_NETGROUP_H */ #include #include #include #include #include #include #ifdef HAVE_DIRENT_H # include # define NAMLEN(dirent) strlen((dirent)->d_name) #else # define dirent direct # define NAMLEN(dirent) (dirent)->d_namlen # ifdef HAVE_SYS_NDIR_H # include # endif # ifdef HAVE_SYS_DIR_H # include # endif # ifdef HAVE_NDIR_H # include # endif #endif #include "sudo.h" #include "parse.h" #include "interfaces.h" #ifndef HAVE_FNMATCH # include "emul/fnmatch.h" #endif /* HAVE_FNMATCH */ #ifndef HAVE_EXTENDED_GLOB # include "emul/glob.h" #endif /* HAVE_EXTENDED_GLOB */ #ifndef lint __unused static const char rcsid[] = "$Sudo: parse.c,v 1.160.2.15 2007/12/04 15:26:40 millert Exp $"; #endif /* lint */ /* * Globals */ int parse_error = FALSE; extern int keepall; extern FILE *yyin, *yyout; /* * Prototypes */ static int has_meta __P((char *)); void init_parser __P((void)); /* * Look up the user in the sudoers file and check to see if they are * allowed to run the specified command on this host as the target user. */ int sudoers_lookup(pwflag) int pwflag; { int error, nopass; /* We opened _PATH_SUDOERS in check_sudoers() so just rewind it. */ rewind(sudoers_fp); yyin = sudoers_fp; yyout = stdout; /* Allocate space for data structures in the parser. */ init_parser(); /* Keep more state for pseudo-commands so that listpw and verifypw work */ if (pwflag > 0) keepall = TRUE; /* Need to be runas user while stat'ing things in the parser. */ set_perms(PERM_RUNAS); error = yyparse(); /* Close the sudoers file now that we are done with it. */ (void) fclose(sudoers_fp); sudoers_fp = NULL; if (error || parse_error) { set_perms(PERM_ROOT); return(VALIDATE_ERROR); } /* * Assume the worst. If the stack is empty the user was * not mentioned at all. */ if (def_authenticate) error = VALIDATE_NOT_OK; else error = VALIDATE_NOT_OK | FLAG_NOPASS; if (pwflag) { SET(error, FLAG_NO_CHECK); } else { SET(error, FLAG_NO_HOST); if (!top) SET(error, FLAG_NO_USER); } /* * Only check the actual command if pwflag is not set. * It is set for the "validate", "list" and "kill" pseudo-commands. * Always check the host and user. */ nopass = -1; if (pwflag) { int found; enum def_tupple pwcheck; pwcheck = (pwflag == -1) ? never : sudo_defs_table[pwflag].sd_un.tuple; if (pwcheck == always && def_authenticate) nopass = FLAG_CHECK_USER; else if (pwcheck == never || !def_authenticate) nopass = FLAG_NOPASS; found = 0; while (top) { if (host_matches == TRUE) { found = 1; if (pwcheck == any && no_passwd == TRUE) nopass = FLAG_NOPASS; else if (pwcheck == all && nopass != 0) nopass = (no_passwd == TRUE) ? FLAG_NOPASS : 0; } top--; } if (found) { set_perms(PERM_ROOT); if (nopass == -1) nopass = 0; return(VALIDATE_OK | nopass); } } else { while (top) { if (host_matches == TRUE) { CLR(error, FLAG_NO_HOST); if (runas_matches == TRUE && cmnd_matches == TRUE) { /* * User was granted access to cmnd on host as user. */ set_perms(PERM_ROOT); return(VALIDATE_OK | (no_passwd == TRUE ? FLAG_NOPASS : 0) | (no_execve == TRUE ? FLAG_NOEXEC : 0) | (setenv_ok >= TRUE ? FLAG_SETENV : 0)); } else if ((runas_matches == TRUE && cmnd_matches == FALSE) || (runas_matches == FALSE && cmnd_matches == TRUE)) { /* * User was explicitly denied access to cmnd on host. */ set_perms(PERM_ROOT); return(VALIDATE_NOT_OK | (no_passwd == TRUE ? FLAG_NOPASS : 0) | (no_execve == TRUE ? FLAG_NOEXEC : 0) | (setenv_ok >= TRUE ? FLAG_SETENV : 0)); } } top--; } } set_perms(PERM_ROOT); /* * The user was neither explicitly granted nor denied access. */ if (nopass == -1) nopass = 0; return(error | nopass); } /* * If path doesn't end in /, return TRUE iff cmnd & path name the same inode; * otherwise, return TRUE if user_cmnd names one of the inodes in path. */ int command_matches(sudoers_cmnd, sudoers_args) char *sudoers_cmnd; char *sudoers_args; { struct stat sudoers_stat; struct dirent *dent; char **ap, *base, buf[PATH_MAX]; glob_t gl; DIR *dirp; /* Check for pseudo-commands */ if (strchr(user_cmnd, '/') == NULL) { /* * Return true if both sudoers_cmnd and user_cmnd are "sudoedit" AND * a) there are no args in sudoers OR * b) there are no args on command line and none req by sudoers OR * c) there are args in sudoers and on command line and they match */ if (strcmp(sudoers_cmnd, "sudoedit") != 0 || strcmp(user_cmnd, "sudoedit") != 0) return(FALSE); if (!sudoers_args || (!user_args && sudoers_args && !strcmp("\"\"", sudoers_args)) || (sudoers_args && fnmatch(sudoers_args, user_args ? user_args : "", 0) == 0)) { efree(safe_cmnd); safe_cmnd = estrdup(sudoers_cmnd); return(TRUE); } else return(FALSE); } /* * If sudoers_cmnd has meta characters in it, use fnmatch(3) * to do the matching. */ if (has_meta(sudoers_cmnd)) { /* * Return true if we find a match in the glob(3) results AND * a) there are no args in sudoers OR * b) there are no args on command line and none required by sudoers OR * c) there are args in sudoers and on command line and they match * else return false. * * Could optimize patterns ending in "/*" to "/user_base" */ #define GLOB_FLAGS (GLOB_NOSORT | GLOB_MARK | GLOB_BRACE | GLOB_TILDE) if (glob(sudoers_cmnd, GLOB_FLAGS, NULL, &gl) != 0) { globfree(&gl); return(FALSE); } /* For each glob match, compare basename, st_dev and st_ino. */ for (ap = gl.gl_pathv; *ap != NULL; ap++) { /* only stat if basenames are the same */ if ((base = strrchr(*ap, '/')) != NULL) base++; else base = *ap; if (strcmp(user_base, base) != 0 || stat(*ap, &sudoers_stat) == -1) continue; if (user_stat->st_dev == sudoers_stat.st_dev && user_stat->st_ino == sudoers_stat.st_ino) { efree(safe_cmnd); safe_cmnd = estrdup(*ap); break; } } globfree(&gl); if (*ap == NULL) return(FALSE); if (!sudoers_args || (!user_args && sudoers_args && !strcmp("\"\"", sudoers_args)) || (sudoers_args && fnmatch(sudoers_args, user_args ? user_args : "", 0) == 0)) { efree(safe_cmnd); safe_cmnd = estrdup(user_cmnd); return(TRUE); } else return(FALSE); } else { size_t dlen = strlen(sudoers_cmnd); /* * No meta characters * Check to make sure this is not a directory spec (doesn't end in '/') */ if (sudoers_cmnd[dlen - 1] != '/') { /* Only proceed if user_base and basename(sudoers_cmnd) match */ if ((base = strrchr(sudoers_cmnd, '/')) == NULL) base = sudoers_cmnd; else base++; if (strcmp(user_base, base) != 0 || stat(sudoers_cmnd, &sudoers_stat) == -1) return(FALSE); /* * Return true if inode/device matches AND * a) there are no args in sudoers OR * b) there are no args on command line and none req by sudoers OR * c) there are args in sudoers and on command line and they match */ if (user_stat->st_dev != sudoers_stat.st_dev || user_stat->st_ino != sudoers_stat.st_ino) return(FALSE); if (!sudoers_args || (!user_args && sudoers_args && !strcmp("\"\"", sudoers_args)) || (sudoers_args && fnmatch(sudoers_args, user_args ? user_args : "", 0) == 0)) { efree(safe_cmnd); safe_cmnd = estrdup(sudoers_cmnd); return(TRUE); } else return(FALSE); } /* * Grot through sudoers_cmnd's directory entries, looking for user_base. */ dirp = opendir(sudoers_cmnd); if (dirp == NULL) return(FALSE); if (strlcpy(buf, sudoers_cmnd, sizeof(buf)) >= sizeof(buf)) return(FALSE); while ((dent = readdir(dirp)) != NULL) { /* ignore paths > PATH_MAX (XXX - log) */ buf[dlen] = '\0'; if (strlcat(buf, dent->d_name, sizeof(buf)) >= sizeof(buf)) continue; /* only stat if basenames are the same */ if (strcmp(user_base, dent->d_name) != 0 || stat(buf, &sudoers_stat) == -1) continue; if (user_stat->st_dev == sudoers_stat.st_dev && user_stat->st_ino == sudoers_stat.st_ino) { efree(safe_cmnd); safe_cmnd = estrdup(buf); break; } } closedir(dirp); return(dent != NULL); } } static int addr_matches_if(n) char *n; { int i; struct in_addr addr; struct interface *ifp; #ifdef HAVE_IN6_ADDR struct in6_addr addr6; int j; #endif int family; #ifdef HAVE_IN6_ADDR if (inet_pton(AF_INET6, n, &addr6) > 0) { family = AF_INET6; } else #endif { family = AF_INET; addr.s_addr = inet_addr(n); } for (i = 0; i < num_interfaces; i++) { ifp = &interfaces[i]; if (ifp->family != family) continue; switch(family) { case AF_INET: if (ifp->addr.ip4.s_addr == addr.s_addr || (ifp->addr.ip4.s_addr & ifp->netmask.ip4.s_addr) == addr.s_addr) return(TRUE); break; #ifdef HAVE_IN6_ADDR case AF_INET6: if (memcmp(ifp->addr.ip6.s6_addr, addr6.s6_addr, sizeof(addr6.s6_addr)) == 0) return(TRUE); for (j = 0; j < sizeof(addr6.s6_addr); j++) { if ((ifp->addr.ip6.s6_addr[j] & ifp->netmask.ip6.s6_addr[j]) != addr6.s6_addr[j]) break; } if (j == sizeof(addr6.s6_addr)) return(TRUE); #endif /* HAVE_IN6_ADDR */ } } return(FALSE); } static int addr_matches_if_netmask(n, m) char *n; char *m; { int i; struct in_addr addr, mask; struct interface *ifp; #ifdef HAVE_IN6_ADDR struct in6_addr addr6, mask6; int j; #endif int family; #ifdef HAVE_IN6_ADDR if (inet_pton(AF_INET6, n, &addr6) > 0) family = AF_INET6; else #endif { family = AF_INET; addr.s_addr = inet_addr(n); } if (family == AF_INET) { if (strchr(m, '.')) mask.s_addr = inet_addr(m); else { i = 32 - atoi(m); mask.s_addr = 0xffffffff; mask.s_addr >>= i; mask.s_addr <<= i; mask.s_addr = htonl(mask.s_addr); } } #ifdef HAVE_IN6_ADDR else { if (inet_pton(AF_INET6, m, &mask6) <= 0) { j = atoi(m); for (i = 0; i < 16; i++) { if (j < i * 8) mask6.s6_addr[i] = 0; else if (i * 8 + 8 <= j) mask6.s6_addr[i] = 0xff; else mask6.s6_addr[i] = 0xff00 >> (j - i * 8); } } } #endif /* HAVE_IN6_ADDR */ for (i = 0; i < num_interfaces; i++) { ifp = &interfaces[i]; if (ifp->family != family) continue; switch(family) { case AF_INET: if ((ifp->addr.ip4.s_addr & mask.s_addr) == addr.s_addr) return(TRUE); #ifdef HAVE_IN6_ADDR case AF_INET6: for (j = 0; j < sizeof(addr6.s6_addr); j++) { if ((ifp->addr.ip6.s6_addr[j] & mask6.s6_addr[j]) != addr6.s6_addr[j]) break; } if (j == sizeof(addr6.s6_addr)) return(TRUE); #endif /* HAVE_IN6_ADDR */ } } return(FALSE); } /* * Returns TRUE if "n" is one of our ip addresses or if * "n" is a network that we are on, else returns FALSE. */ int addr_matches(n) char *n; { char *m; int retval; /* If there's an explicit netmask, use it. */ if ((m = strchr(n, '/'))) { *m++ = '\0'; retval = addr_matches_if_netmask(n, m); *(m - 1) = '/'; } else retval = addr_matches_if(n); return(retval); } /* * Returns 0 if the hostname matches the pattern and non-zero otherwise. */ int hostname_matches(shost, lhost, pattern) char *shost; char *lhost; char *pattern; { if (has_meta(pattern)) { if (strchr(pattern, '.')) return(fnmatch(pattern, lhost, FNM_CASEFOLD)); else return(fnmatch(pattern, shost, FNM_CASEFOLD)); } else { if (strchr(pattern, '.')) return(strcasecmp(lhost, pattern)); else return(strcasecmp(shost, pattern)); } } /* * Returns TRUE if the user/uid from sudoers matches the specified user/uid, * else returns FALSE. */ int userpw_matches(sudoers_user, user, pw) char *sudoers_user; char *user; struct passwd *pw; { if (pw != NULL && *sudoers_user == '#') { uid_t uid = atoi(sudoers_user + 1); if (uid == pw->pw_uid) return(1); } return(strcmp(sudoers_user, user) == 0); } /* * Returns TRUE if the given user belongs to the named group, * else returns FALSE. * XXX - reduce the number of passwd/group lookups */ int usergr_matches(group, user, pw) char *group; char *user; struct passwd *pw; { struct group *grp; gid_t pw_gid; char **cur; int i; /* make sure we have a valid usergroup, sudo style */ if (*group++ != '%') return(FALSE); /* look up user's primary gid in the passwd file */ if (pw == NULL && (pw = getpwnam(user)) == NULL) return(FALSE); pw_gid = pw->pw_gid; if ((grp = getgrnam(group)) == NULL) return(FALSE); /* check against user's primary (passwd file) gid */ if (grp->gr_gid == pw_gid) return(TRUE); /* * If the user has a supplementary group vector, check it first. */ for (i = 0; i < user_ngroups; i++) { if (grp->gr_gid == user_groups[i]) return(TRUE); } if (grp->gr_mem != NULL) { for (cur = grp->gr_mem; *cur; cur++) { if (strcmp(*cur, user) == 0) return(TRUE); } } return(FALSE); } /* * Returns TRUE if "host" and "user" belong to the netgroup "netgr", * else return FALSE. Either of "host", "shost" or "user" may be NULL * in which case that argument is not checked... */ int netgr_matches(netgr, host, shost, user) char *netgr; char *host; char *shost; char *user; { static char *domain; #ifdef HAVE_GETDOMAINNAME static int initialized; #endif /* make sure we have a valid netgroup, sudo style */ if (*netgr++ != '+') return(FALSE); #ifdef HAVE_GETDOMAINNAME /* get the domain name (if any) */ if (!initialized) { domain = (char *) emalloc(MAXHOSTNAMELEN); if (getdomainname(domain, MAXHOSTNAMELEN) == -1 || *domain == '\0') { efree(domain); domain = NULL; } initialized = 1; } #endif /* HAVE_GETDOMAINNAME */ #ifdef HAVE_INNETGR if (innetgr(netgr, host, user, domain)) return(TRUE); else if (host != shost && innetgr(netgr, shost, user, domain)) return(TRUE); #endif /* HAVE_INNETGR */ return(FALSE); } /* * Returns TRUE if "s" has shell meta characters in it, * else returns FALSE. */ static int has_meta(s) char *s; { char *t; for (t = s; *t; t++) { if (*t == '\\' || *t == '?' || *t == '*' || *t == '[' || *t == ']') return(TRUE); } return(FALSE); }