diff --git a/lib/libpam/modules/pam_login_access/login_access.c b/lib/libpam/modules/pam_login_access/login_access.c index 9496081d362e..719808858dac 100644 --- a/lib/libpam/modules/pam_login_access/login_access.c +++ b/lib/libpam/modules/pam_login_access/login_access.c @@ -1,297 +1,297 @@ /* * This module implements a simple but effective form of login access * control based on login names and on host (or domain) names, internet * addresses (or network numbers), or on terminal line names in case of * non-networked logins. Diagnostics are reported through syslog(3). * * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. */ #if 0 #ifndef lint static char sccsid[] = "%Z% %M% %I% %E% %U%"; #endif #endif #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include "pam_login_access.h" /* Constants to be used in assignments only, not in comparisons... */ #define YES 1 #define NO 0 static int from_match(const char *, const char *, struct pam_login_access_options *); static int list_match(char *, const char *, int (*)(const char *, const char *, struct pam_login_access_options *), struct pam_login_access_options *); static int netgroup_match(const char *, const char *, const char *); static int string_match(const char *, const char *); static int user_match(const char *, const char *, struct pam_login_access_options *); static int group_match(const char *, const char *); /* login_access - match username/group and host/tty with access control file */ int login_access(const char *user, const char *from, struct pam_login_access_options *login_access_opts) { FILE *fp; char line[BUFSIZ]; char *perm; /* becomes permission field */ char *users; /* becomes list of login names */ char *froms; /* becomes list of terminals or hosts */ int match = NO; int end; int lineno = 0; /* for diagnostics */ const char *fieldsep = login_access_opts->fieldsep; /* * Process the table one line at a time and stop at the first match. * Blank lines and lines that begin with a '#' character are ignored. * Non-comment lines are broken at the ':' character. All fields are * mandatory. The first field should be a "+" or "-" character. A * non-existing table means no access control. */ if ((fp = fopen(login_access_opts->accessfile, "r")) != NULL) { while (!match && fgets(line, sizeof(line), fp)) { lineno++; if (line[end = strlen(line) - 1] != '\n') { syslog(LOG_ERR, "%s: line %d: missing newline or line too long", login_access_opts->accessfile, lineno); continue; } if (line[0] == '#') continue; /* comment line */ while (end > 0 && isspace(line[end - 1])) end--; line[end] = 0; /* strip trailing whitespace */ if (line[0] == 0) /* skip blank lines */ continue; if (!(perm = strtok(line, fieldsep)) || !(users = strtok((char *) 0, fieldsep)) || !(froms = strtok((char *) 0, fieldsep)) || strtok((char *) 0, fieldsep)) { syslog(LOG_ERR, "%s: line %d: bad field count", login_access_opts->accessfile, lineno); continue; } if (perm[0] != '+' && perm[0] != '-') { syslog(LOG_ERR, "%s: line %d: bad first field", login_access_opts->accessfile, lineno); continue; } match = (list_match(froms, from, from_match, login_access_opts) && list_match(users, user, user_match, login_access_opts)); } (void) fclose(fp); } else if (errno != ENOENT) { syslog(LOG_ERR, "cannot open %s: %m", login_access_opts->accessfile); } return (match == 0 || (line[0] == '+')); } /* list_match - match an item against a list of tokens with exceptions */ static int list_match(char *list, const char *item, int (*match_fn)(const char *, const char *, struct pam_login_access_options *), struct pam_login_access_options *login_access_opts) { char *tok; int match = NO; const char *listsep = login_access_opts->listsep; /* * Process tokens one at a time. We have exhausted all possible matches * when we reach an "EXCEPT" token or the end of the list. If we do find * a match, look for an "EXCEPT" list and recurse to determine whether * the match is affected by any exceptions. */ for (tok = strtok(list, listsep); tok != NULL; tok = strtok((char *) 0, listsep)) { if (strcmp(tok, "EXCEPT") == 0) /* EXCEPT: give up */ break; if ((match = (*match_fn)(tok, item, login_access_opts)) != 0) /* YES */ break; } /* Process exceptions to matches. */ if (match != NO) { while ((tok = strtok((char *) 0, listsep)) && strcmp(tok, "EXCEPT")) { /* VOID */ ; - if (tok == NULL || list_match((char *) 0, item, match_fn, - login_access_opts) == NO) { + } + if (tok == NULL || + list_match((char *) 0, item, match_fn, login_access_opts) == NO) { return (match); - } } } return (NO); } /* netgroup_match - match group against machine or user */ static int netgroup_match(const char *group, const char *machine, const char *user) { char domain[1024]; unsigned int i; if (getdomainname(domain, sizeof(domain)) != 0 || *domain == '\0') { syslog(LOG_ERR, "NIS netgroup support disabled: no NIS domain"); return (NO); } /* getdomainname() does not reliably terminate the string */ for (i = 0; i < sizeof(domain); ++i) if (domain[i] == '\0') break; if (i == sizeof(domain)) { syslog(LOG_ERR, "NIS netgroup support disabled: invalid NIS domain"); return (NO); } if (innetgr(group, machine, user, domain) == 1) return (YES); return (NO); } /* group_match - match a group against one token */ int group_match(const char *tok, const char *username) { struct group *group; struct passwd *passwd; gid_t *grouplist; int i, ret, ngroups = NGROUPS; if ((passwd = getpwnam(username)) == NULL) return (NO); errno = 0; if ((group = getgrnam(tok)) == NULL) { if (errno != 0) syslog(LOG_ERR, "getgrnam() failed for %s: %s", username, strerror(errno)); else syslog(LOG_NOTICE, "group not found: %s", username); return (NO); } if ((grouplist = calloc(ngroups, sizeof(gid_t))) == NULL) { syslog(LOG_ERR, "cannot allocate memory for grouplist: %s", username); return (NO); } ret = NO; if (getgrouplist(username, passwd->pw_gid, grouplist, &ngroups) != 0) syslog(LOG_ERR, "getgrouplist() failed for %s", username); for (i = 0; i < ngroups; i++) if (grouplist[i] == group->gr_gid) ret = YES; free(grouplist); return (ret); } /* user_match - match a username against one token */ static int user_match(const char *tok, const char *string, struct pam_login_access_options *login_access_opts) { size_t stringlen; char *grpstr; int rc; /* * If a token has the magic value "ALL" the match always succeeds. * Otherwise, return YES if the token fully matches the username, or if * the token is a group that contains the username. */ if (tok[0] == '@') { /* netgroup */ return (netgroup_match(tok + 1, (char *) 0, string)); } else if (tok[0] == '(' && tok[(stringlen = strlen(&tok[1]))] == ')') { /* group */ if ((grpstr = strndup(&tok[1], stringlen - 1)) == NULL) { syslog(LOG_ERR, "cannot allocate memory for %s", string); return (NO); } rc = group_match(grpstr, string); free(grpstr); return (rc); } else if (string_match(tok, string)) { /* ALL or exact match */ return (YES); } else if (login_access_opts->defgroup == true) {/* try group membership */ return (group_match(tok, string)); } return (NO); } /* from_match - match a host or tty against a list of tokens */ static int from_match(const char *tok, const char *string, struct pam_login_access_options *login_access_opts __unused) { int tok_len; int str_len; /* * If a token has the magic value "ALL" the match always succeeds. Return * YES if the token fully matches the string. If the token is a domain * name, return YES if it matches the last fields of the string. If the * token has the magic value "LOCAL", return YES if the string does not * contain a "." character. If the token is a network number, return YES * if it matches the head of the string. */ if (tok[0] == '@') { /* netgroup */ return (netgroup_match(tok + 1, string, (char *) 0)); } else if (string_match(tok, string)) { /* ALL or exact match */ return (YES); } else if (tok[0] == '.') { /* domain: match last fields */ if ((str_len = strlen(string)) > (tok_len = strlen(tok)) && strcasecmp(tok, string + str_len - tok_len) == 0) return (YES); } else if (strcmp(tok, "LOCAL") == 0) { /* local: no dots */ if (strchr(string, '.') == NULL) return (YES); } else if (tok[(tok_len = strlen(tok)) - 1] == '.' /* network */ && strncmp(tok, string, tok_len) == 0) { return (YES); } return (NO); } /* string_match - match a string against one token */ static int string_match(const char *tok, const char *string) { /* * If the token has the magic value "ALL" the match always succeeds. * Otherwise, return YES if the token fully matches the string. */ if (strcmp(tok, "ALL") == 0) { /* all: always matches */ return (YES); } else if (strcasecmp(tok, string) == 0) { /* try exact match */ return (YES); } return (NO); }