From 1e78305dcf5d03fbd569dcb8a28255c0a50dc21a Mon Sep 17 00:00:00 2001 From: Anders Kaseorg Date: Sun, 17 Feb 2008 19:40:53 -0500 Subject: [PATCH] Bug fixes and cleanups. Signed-off-by: Anders Kaseorg --- nonlocal-group.c | 176 +++++++++++++++++++++++++++++----------------- nonlocal-passwd.c | 1 + 2 files changed, 112 insertions(+), 65 deletions(-) diff --git a/nonlocal-group.c b/nonlocal-group.c index 19d3d2c..56caa44 100644 --- a/nonlocal-group.c +++ b/nonlocal-group.c @@ -92,7 +92,7 @@ get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen enum nss_status status = NSS_STATUS_NOTFOUND; struct group gbuf; struct group *gbufp = &gbuf; - int ret; + int ret, n; int old_errno = errno; int len = MAGIC_LOCAL_GR_BUFLEN; char *buf = malloc(len); @@ -108,21 +108,39 @@ get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen status = NSS_STATUS_TRYAGAIN; } else if (gbufp != NULL) { status = NSS_STATUS_SUCCESS; - grp->gr_name = strncpy(buffer, gbufp->gr_name, buflen); - buffer = buffer + strlen(grp->gr_name); - buflen = buflen - strlen(grp->gr_name); - grp->gr_passwd = strncpy(buffer, gbufp->gr_passwd, buflen); - buffer = buffer + strlen(grp->gr_passwd); - buflen = buflen - strlen(grp->gr_passwd); + + n = snprintf(buffer, buflen, "%s", gbufp->gr_name); + if (n < 0 || n >= buflen) { + *errnop = ERANGE; + status = NSS_STATUS_TRYAGAIN; + goto get_local_group_done; + } + grp->gr_name = buffer; + buffer += n; + buflen -= n; + + n = snprintf(buffer, buflen, "%s", gbufp->gr_passwd); + if (n < 0 || n >= buflen) { + *errnop = ERANGE; + status = NSS_STATUS_TRYAGAIN; + goto get_local_group_done; + } + grp->gr_passwd = buffer; + buffer += n; + buflen -= n; + grp->gr_gid = gbufp->gr_gid; + if (buflen < sizeof(void *)) { *errnop = ERANGE; status = NSS_STATUS_TRYAGAIN; + goto get_local_group_done; } - else { - grp->gr_mem = memset(buffer, 0, sizeof(void *)); - } + *(void **)buffer = NULL; + buffer += sizeof(void *); + buflen -= sizeof(void *); } + get_local_group_done: free(buf); errno = old_errno; return status; @@ -321,51 +339,100 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, int *errnop); void *ptr; } fct; - int in = *start, out = *start, i; - gid_t local_users_gid; + + struct group local_users_group, nonlocal_users_group; + gid_t local_users_gid, gid; int is_local = 0; + int buflen; + char *buffer; - // Check that the user is a nonlocal user before adding any groups + /* Check that the user is a nonlocal user before adding any groups. */ status = check_nonlocal_user(user, errnop); - if (status == NSS_STATUS_NOTFOUND) { + if (status == NSS_STATUS_NOTFOUND) is_local = 1; - } - else if (status != NSS_STATUS_SUCCESS) { + else if (status != NSS_STATUS_SUCCESS) return status; - } - int buflen = sysconf(_SC_GETGR_R_SIZE_MAX); - char *buffer = malloc(buflen); + int old_errno = errno; + + buflen = sysconf(_SC_GETGR_R_SIZE_MAX); + buffer = malloc(buflen); if (buffer == NULL) { *errnop = ENOMEM; + errno = old_errno; return NSS_STATUS_TRYAGAIN; } - struct group local_users_group; status = get_local_group(MAGIC_LOCAL_GROUPNAME, &local_users_group, buffer, buflen, errnop); - free(buffer); if (status == NSS_STATUS_NOTFOUND) { syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", MAGIC_LOCAL_GROUPNAME); - local_users_gid = 0; - } - else if (status == NSS_STATUS_SUCCESS) { - if (is_local == 1) { - // add the (local) user to the magic local users group, and finish - (*groupsp)[out++] = local_users_group.gr_gid; - syslog(LOG_DEBUG, "nss_nonlocal: Added %s to special group %s", - user, MAGIC_LOCAL_GROUPNAME); - *start = out; - return NSS_STATUS_SUCCESS; - } - else { - local_users_gid = local_users_group.gr_gid; + local_users_gid = -1; + } else if (status != NSS_STATUS_SUCCESS) { + return status; + } else + local_users_gid = local_users_group.gr_gid; + free(buffer); + + if (is_local) { + gid = local_users_gid; + } else { + buflen = sysconf(_SC_GETGR_R_SIZE_MAX); + buffer = malloc(buflen); + if (buffer == NULL) { + *errnop = ENOMEM; + errno = old_errno; + return NSS_STATUS_TRYAGAIN; } + status = get_local_group(MAGIC_NONLOCAL_GROUPNAME, + &nonlocal_users_group, buffer, buflen, errnop); + if (status == NSS_STATUS_NOTFOUND) { + syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", + MAGIC_NONLOCAL_GROUPNAME); + gid = -1; + } else if (status != NSS_STATUS_SUCCESS) { + errno = old_errno; + return status; + } else + gid = nonlocal_users_group.gr_gid; + free(buffer); } - else { - return status; + + if (gid != -1) { + int i; + for (i = 0; i < *start; ++i) + if ((*groupsp)[i] == gid) + break; + if (i >= *start) { + if (*start + 1 > *size) { + gid_t *newgroups; + long int newsize = 2 * *size; + if (limit > 0) { + if (*size >= limit) + return NSS_STATUS_SUCCESS; + if (newsize > limit) + newsize = limit; + } + newgroups = realloc(*groupsp, *size * sizeof((*groupsp)[0])); + if (newgroups == NULL) { + *errnop = ENOMEM; + errno = old_errno; + return NSS_STATUS_TRYAGAIN; + } + *groupsp = newgroups; + *size = newsize; + } + (*groupsp)[(*start)++] = gid; + } } + errno = old_errno; + + if (is_local) + return NSS_STATUS_SUCCESS; + + int in = *start, out = *start, i; + nip = nss_group_nonlocal_database(); if (nip == NULL) return NSS_STATUS_UNAVAIL; @@ -393,16 +460,16 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, if (i < out) continue; + /* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */ + if (local_users_gid == (*groupsp)[in]) { + syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s", + user, MAGIC_LOCAL_GROUPNAME); + continue; + } + status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno); if (status == NSS_STATUS_SUCCESS) { - // Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. - if ((*groupsp)[in] == local_users_gid) { - syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s", - user, MAGIC_LOCAL_GROUPNAME); - } - else { - (*groupsp)[out++] = (*groupsp)[in]; - } + (*groupsp)[out++] = (*groupsp)[in]; } else if (status != NSS_STATUS_NOTFOUND) { *start = out; *errnop = nonlocal_errno; @@ -410,27 +477,6 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, } } - // add the (nonlocal) user to the magic nonlocal users group - buflen = sysconf(_SC_GETGR_R_SIZE_MAX); - buffer = malloc(buflen); - if (buffer == NULL) { - *errnop = ENOMEM; - return NSS_STATUS_TRYAGAIN; - } - struct group nonlocal_users_group; - status = get_local_group(MAGIC_NONLOCAL_GROUPNAME, - &nonlocal_users_group, buffer, buflen, errnop); - if (status == NSS_STATUS_NOTFOUND) { - syslog(LOG_WARNING, "nss_nonlocal: (local) group %s does not exist!", - MAGIC_NONLOCAL_GROUPNAME); - } - else if (status == NSS_STATUS_SUCCESS) { - (*groupsp)[out++] = nonlocal_users_group.gr_gid; - syslog(LOG_DEBUG, "nss_nonlocal: Added %s to special group %s", - user, MAGIC_NONLOCAL_GROUPNAME); - } - free(buffer); - *start = out; return NSS_STATUS_SUCCESS; } diff --git a/nonlocal-passwd.c b/nonlocal-passwd.c index 041257e..05a06bf 100644 --- a/nonlocal-passwd.c +++ b/nonlocal-passwd.c @@ -114,6 +114,7 @@ check_nonlocal_user(const char *user, int *errnop) return status; } + static service_user *pwent_nip = NULL; static void *pwent_fct_start; static union { -- 2.44.0