From 8aa9014e0bf3469e2a9a47ec25dc3e6d5d30224f Mon Sep 17 00:00:00 2001 From: Anders Kaseorg Date: Sun, 24 May 2009 17:12:26 -0400 Subject: [PATCH] Simplify get_local_group to return the allocated buffer instead of copying. Signed-off-by: Anders Kaseorg --- nonlocal-group.c | 86 +++++++++++------------------------------------- 1 file changed, 19 insertions(+), 67 deletions(-) diff --git a/nonlocal-group.c b/nonlocal-group.c index 085fafd..3eb9fe9 100644 --- a/nonlocal-group.c +++ b/nonlocal-group.c @@ -127,7 +127,7 @@ check_nonlocal_gid(const char *user, gid_t gid, int *errnop) } enum nss_status -get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen, int *errnop) +get_local_group(const char *name, struct group *grp, char **buffer, int *errnop) { static const char *fct_name = "getgrnam_r"; static service_user *startp = NULL; @@ -139,13 +139,12 @@ get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen char *buffer, size_t buflen, int *errnop); void *ptr; } fct; - struct group gbuf; - int n; + size_t buflen; int old_errno = errno; - int len = sysconf(_SC_GETGR_R_SIZE_MAX); - char *buf = malloc(len); - if (buf == NULL) { + buflen = sysconf(_SC_GETGR_R_SIZE_MAX); + *buffer = malloc(buflen); + if (*buffer == NULL) { *errnop = ENOMEM; errno = old_errno; return NSS_STATUS_TRYAGAIN; @@ -153,7 +152,8 @@ get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen if (fct_start == NULL && __nss_group_lookup(&startp, fct_name, &fct_start) != 0) { - free(buf); + free(*buffer); + *buffer = NULL; return NSS_STATUS_UNAVAIL; } nip = startp; @@ -163,12 +163,12 @@ get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen if (fct.l == _nss_nonlocal_getgrnam_r) status = NSS_STATUS_NOTFOUND; else - status = DL_CALL_FCT(fct.l, (name, &gbuf, buf, len, errnop)); + status = DL_CALL_FCT(fct.l, (name, grp, *buffer, buflen, errnop)); if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) { - free(buf); - len *= 2; - buf = malloc(len); - if (buf == NULL) { + free(*buffer); + buflen *= 2; + *buffer = malloc(buflen); + if (*buffer == NULL) { *errnop = ENOMEM; errno = old_errno; return NSS_STATUS_TRYAGAIN; @@ -177,42 +177,11 @@ get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen } } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0); - if (status != NSS_STATUS_SUCCESS) - goto get_local_group_done; - - n = snprintf(buffer, buflen, "%s", gbuf.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", gbuf.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 = gbuf.gr_gid; - - if (buflen < sizeof(void *)) { - *errnop = ERANGE; - status = NSS_STATUS_TRYAGAIN; - goto get_local_group_done; + if (status != NSS_STATUS_SUCCESS) { + free(*buffer); + *buffer = NULL; } - *(void **)buffer = NULL; - buffer += sizeof(void *); - buflen -= sizeof(void *); - get_local_group_done: - free(buf); return status; } @@ -420,7 +389,6 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, 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. */ @@ -432,50 +400,34 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start, 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; - } status = get_local_group(MAGIC_LOCAL_GROUPNAME, - &local_users_group, buffer, buflen, errnop); + &local_users_group, &buffer, errnop); if (status == NSS_STATUS_SUCCESS) { local_users_gid = local_users_group.gr_gid; - } else if (status == NSS_STATUS_TRYAGAIN) { free(buffer); + } else if (status == NSS_STATUS_TRYAGAIN) { return status; } else { syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", MAGIC_LOCAL_GROUPNAME); local_users_gid = -1; } - 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); + &nonlocal_users_group, &buffer, errnop); if (status == NSS_STATUS_SUCCESS) { gid = nonlocal_users_group.gr_gid; - } else if (status == NSS_STATUS_TRYAGAIN) { free(buffer); + } else if (status == NSS_STATUS_TRYAGAIN) { return status; } else { syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!", MAGIC_NONLOCAL_GROUPNAME); gid = -1; } - free(buffer); } if (gid != -1) { -- 2.45.0