From f7293a540408a83631cd04ec767962f60b96610f Mon Sep 17 00:00:00 2001 From: Anders Kaseorg Date: Fri, 3 Aug 2007 22:00:25 -0400 Subject: [PATCH] Use a magic buflen instead of thread-local variables, to avoid strange problems on sarge. Signed-off-by: Anders Kaseorg --- nonlocal-group.c | 65 +++++++++++++++-------------------------------- nonlocal-passwd.c | 65 +++++++++++++++-------------------------------- 2 files changed, 42 insertions(+), 88 deletions(-) diff --git a/nonlocal-group.c b/nonlocal-group.c index 9071fe1..aa2e390 100644 --- a/nonlocal-group.c +++ b/nonlocal-group.c @@ -40,6 +40,8 @@ #include "nsswitch-internal.h" #include "nonlocal.h" +#define MAGIC_LOCAL_GR_BUFLEN (sysconf(_SC_GETGR_R_SIZE_MAX) + 7) + static service_user * nss_group_nonlocal_database(void) @@ -52,57 +54,32 @@ nss_group_nonlocal_database(void) } -static __thread int local_only = 0; - -enum nss_status -local_getgrgid_r(gid_t gid, struct group *grp, - char *buffer, size_t buflen, int *errnop) -{ - int old_local_only = local_only; - int old_errno = errno; - int ret; - errno = *errnop; - local_only = 1; - - ret = getgrgid_r(gid, grp, buffer, buflen, &grp); - - local_only = old_local_only; - *errnop = errno; - errno = old_errno; - - if (grp != NULL) - return NSS_STATUS_SUCCESS; - else if (ret == 0) - return NSS_STATUS_NOTFOUND; - else - return NSS_STATUS_TRYAGAIN; -} - enum nss_status check_nonlocal_gid(const char *user, gid_t gid, int *errnop) { - struct group local_grp; - int local_errno = errno; - enum nss_status local_status, status = NSS_STATUS_SUCCESS; - int local_buflen = sysconf(_SC_GETGR_R_SIZE_MAX); - char *local_buffer = malloc(local_buflen); - if (local_buffer == NULL) { + enum nss_status status = NSS_STATUS_SUCCESS; + struct group gbuf; + struct group *gbufp = &gbuf; + int ret; + int old_errno = errno; + int buflen = MAGIC_LOCAL_GR_BUFLEN; + char *buf = malloc(buflen); + if (buf == NULL) { *errnop = ENOMEM; - errno = local_errno; + errno = old_errno; return NSS_STATUS_TRYAGAIN; } - local_errno = 0; - local_status = local_getgrgid_r(gid, &local_grp, local_buffer, - local_buflen, &local_errno); - if (local_status == NSS_STATUS_SUCCESS) { - syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", local_grp.gr_gid, local_grp.gr_name, user); + errno = 0; + ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp); + if (ret != 0) { + *errnop = old_errno; + status = NSS_STATUS_TRYAGAIN; + } else if (gbufp != NULL) { + syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user); status = NSS_STATUS_NOTFOUND; - } else if (local_status != NSS_STATUS_NOTFOUND && - local_status != NSS_STATUS_UNAVAIL) { - *errnop = local_errno; - status = local_status; } - free(local_buffer); + free(buf); + errno = old_errno; return status; } @@ -259,7 +236,7 @@ _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp, void *ptr; } fct; - if (local_only == 1) + if (buflen == MAGIC_LOCAL_GR_BUFLEN) return NSS_STATUS_UNAVAIL; nip = nss_group_nonlocal_database(); diff --git a/nonlocal-passwd.c b/nonlocal-passwd.c index cebc819..1517341 100644 --- a/nonlocal-passwd.c +++ b/nonlocal-passwd.c @@ -42,6 +42,8 @@ #include "nsswitch-internal.h" #include "nonlocal.h" +#define MAGIC_LOCAL_PW_BUFLEN (sysconf(_SC_GETPW_R_SIZE_MAX) + 7) + static service_user * nss_passwd_nonlocal_database(void) @@ -54,57 +56,32 @@ nss_passwd_nonlocal_database(void) } -static __thread int local_only = 0; - -enum nss_status -local_getpwuid_r(uid_t uid, struct passwd *pwd, - char *buffer, size_t buflen, int *errnop) -{ - int old_local_only = local_only; - int old_errno = errno; - int ret; - errno = *errnop; - local_only = 1; - - ret = getpwuid_r(uid, pwd, buffer, buflen, &pwd); - - local_only = old_local_only; - *errnop = errno; - errno = old_errno; - - if (pwd != NULL) - return NSS_STATUS_SUCCESS; - else if (ret == 0) - return NSS_STATUS_NOTFOUND; - else - return NSS_STATUS_TRYAGAIN; -} - enum nss_status check_nonlocal_uid(const char *user, uid_t uid, int *errnop) { - struct passwd local_pwd; - int local_errno = errno; - enum nss_status local_status, status = NSS_STATUS_SUCCESS; - int local_buflen = sysconf(_SC_GETPW_R_SIZE_MAX); - char *local_buffer = malloc(local_buflen); - if (local_buffer == NULL) { + enum nss_status status = NSS_STATUS_SUCCESS; + struct passwd pwbuf; + struct passwd *pwbufp = &pwbuf; + int ret; + int old_errno = errno; + int buflen = MAGIC_LOCAL_PW_BUFLEN; + char *buf = malloc(buflen); + if (buf == NULL) { *errnop = ENOMEM; - errno = local_errno; + errno = old_errno; return NSS_STATUS_TRYAGAIN; } - local_errno = 0; - local_status = local_getpwuid_r(uid, &local_pwd, local_buffer, - local_buflen, &local_errno); - if (local_status == NSS_STATUS_SUCCESS) { - syslog(LOG_ERR, "nss_nonlocal: possible spoofing attack: non-local user %s has same UID as local user %s!\n", user, local_pwd.pw_name); + errno = 0; + ret = getpwuid_r(uid, pwbufp, buf, buflen, &pwbufp); + if (ret != 0) { + *errnop = errno; + status = NSS_STATUS_TRYAGAIN; + } else if (pwbufp != NULL) { + syslog(LOG_ERR, "nss_nonlocal: possible spoofing attack: non-local user %s has same UID as local user %s!\n", user, pwbuf.pw_name); status = NSS_STATUS_NOTFOUND; - } else if (local_status != NSS_STATUS_NOTFOUND && - local_status != NSS_STATUS_UNAVAIL) { - *errnop = local_errno; - status = local_status; } - free(local_buffer); + free(buf); + errno = old_errno; return status; } @@ -270,7 +247,7 @@ _nss_nonlocal_getpwuid_r(uid_t uid, struct passwd *pwd, } fct; int group_errno; - if (local_only == 1) + if (buflen == MAGIC_LOCAL_PW_BUFLEN) return NSS_STATUS_UNAVAIL; nip = nss_passwd_nonlocal_database(); -- 2.44.0