diff options
Diffstat (limited to 'nis')
| -rw-r--r-- | nis/nss_nis/nis-initgroups.c | 211 |
1 files changed, 204 insertions, 7 deletions
diff --git a/nis/nss_nis/nis-initgroups.c b/nis/nss_nis/nis-initgroups.c index 4c97988..4469e4f 100644 --- a/nis/nss_nis/nis-initgroups.c +++ b/nis/nss_nis/nis-initgroups.c @@ -22,6 +22,9 @@ #include <errno.h> #include <grp.h> #include <nss.h> +#include <pwd.h> +#include <stdio.h> +#include <stdio_ext.h> #include <string.h> #include <unistd.h> #include <rpcsvc/yp.h> @@ -79,15 +82,11 @@ saveit (int instatus, char *inkey, int inkeylen, char *inval, } static enum nss_status -internal_setgrent (intern_t *intern) +internal_setgrent (char *domainname, intern_t *intern) { - char *domainname; struct ypall_callback ypcb; enum nss_status status; - if (yp_get_default_domain (&domainname)) - return NSS_STATUS_UNAVAIL; - intern->start = NULL; ypcb.foreach = saveit; @@ -107,7 +106,7 @@ internal_getgrent_r (struct group *grp, char *buffer, size_t buflen, char *p; if (intern->start == NULL) - internal_setgrent (intern); + return NSS_STATUS_NOTFOUND; /* Get the next entry until we found a correct one. */ do @@ -129,11 +128,209 @@ internal_getgrent_r (struct group *grp, char *buffer, size_t buflen, return NSS_STATUS_SUCCESS; } + +static int init; +static int use_netid; + + +static const char default_nss[] = "/etc/default/nss"; + +static void +check_default_nss (void) +{ + FILE *fp = fopen (default_nss, "rc"); + if (fp != NULL) + { + char *line = NULL; + size_t linelen = 0; + + __fsetlocking (fp, FSETLOCKING_BYCALLER); + + while (!feof_unlocked (fp)) + { + ssize_t n = getline (&line, &linelen, fp); + if (n <= 0) + break; + + /* There currently is only one variable we expect, so + simplify the parsing. Recognize only + + NETID_AUTHORITATIVE = TRUE + + with arbitrary white spaces. */ + char *cp = line; + while (isspace (*cp)) + ++cp; + + static const char netid_authoritative[] = "NETID_AUTHORITATIVE"; + if (strncmp (cp, netid_authoritative, + sizeof (netid_authoritative) - 1) != 0) + continue; + + cp += sizeof (netid_authoritative) - 1; + while (isspace (*cp)) + ++cp; + if (*cp++ != '=') + continue; + while (isspace (*cp)) + ++cp; + + if (strncmp (cp, "TRUE", 4) != 0) + continue; + cp +=4; + + while (isspace (*cp)) + ++cp; + + if (*cp == '\0') + use_netid = 1; + + /* For now, just drop out of the loop. */ + break; + } + + free (line); + + fclose (fp); + } + init = 1; +} + + +static int +get_uid (const char *user, uid_t *uidp) +{ + size_t buflen = sysconf (_SC_GETPW_R_SIZE_MAX); + char *buf = (char *) alloca (buflen); + + while (1) + { + struct passwd result; + struct passwd *resp; + + int r = getpwnam_r (user, &result, buf, buflen, &resp); + if (r == 0 && resp != NULL) + { + *uidp = resp->pw_uid; + return 0; + } + + if (r != ERANGE) + break; + + extend_alloca (buf, buflen, 2 * buflen); + } + + return 1; +} + + +static enum nss_status +initgroups_netid (uid_t uid, gid_t group, long int *start, long int *size, + gid_t **groupsp, long int limit, int *errnop, + const char *domainname) +{ + /* Prepare the key. The form is "unix.UID@DOMAIN" with the UID and + DOMAIN field filled in appropriately. */ + char key[sizeof ("unix.@") + sizeof (uid_t) * 3 + strlen (domainname)]; + ssize_t keylen = snprintf (key, sizeof (key), "unix.%lu@%s", + (unsigned long int) uid, domainname); + + enum nss_status retval; + char *result; + int reslen; + retval = yperr2nss (yp_match (domainname, "netid.byname", key, keylen, + &result, &reslen)); + if (retval != NSS_STATUS_SUCCESS) + return retval; + + /* Parse the result: following the colon is a comma separated list of + group IDs. */ + char *cp = strchr (result, ':'); + if (cp == NULL) + { + errout: + free (result); + return NSS_STATUS_NOTFOUND; + } + /* Skip the colon. */ + ++cp; + + gid_t *groups = *groupsp; + while (*cp != '\0') + { + char *endp; + unsigned long int gid = strtoul (cp, &endp, 0); + if (cp == endp) + goto errout; + if (*endp == ',') + ++endp; + else if (*endp != '\0') + goto errout; + cp = endp; + + if (gid == group) + /* We do not need this group again. */ + continue; + + /* Insert this group. */ + if (*start == *size) + { + /* Need a bigger buffer. */ + gid_t *newgroups; + long int newsize; + + if (limit > 0 && *size == limit) + /* We reached the maximum. */ + break; + + if (limit <= 0) + newsize = 2 * *size; + else + newsize = MIN (limit, 2 * *size); + + newgroups = realloc (groups, newsize * sizeof (*groups)); + if (newgroups == NULL) + goto errout; + *groupsp = groups = newgroups; + *size = newsize; + } + + groups[*start] = gid; + *start += 1; + } + + free (result); + + return NSS_STATUS_SUCCESS; +} + + enum nss_status _nss_nis_initgroups_dyn (const char *user, gid_t group, long int *start, long int *size, gid_t **groupsp, long int limit, int *errnop) { + /* We always need the domain name. */ + char *domainname; + if (yp_get_default_domain (&domainname)) + return NSS_STATUS_UNAVAIL; + + /* Check whether we are supposed to use the netid.byname map. */ + if (!init) + check_default_nss (); + + if (use_netid) + { + /* We need the user ID. */ + uid_t uid; + + if (get_uid (user, &uid) == 0 + && initgroups_netid (uid, group, start, size, groupsp, limit, + errnop, domainname) == NSS_STATUS_SUCCESS) + return NSS_STATUS_SUCCESS; + } + struct group grpbuf, *g; size_t buflen = sysconf (_SC_GETPW_R_SIZE_MAX); char *tmpbuf; @@ -141,7 +338,7 @@ _nss_nis_initgroups_dyn (const char *user, gid_t group, long int *start, intern_t intern = { NULL, NULL }; gid_t *groups = *groupsp; - status = internal_setgrent (&intern); + status = internal_setgrent (domainname, &intern); if (status != NSS_STATUS_SUCCESS) return status; |