Skip the nonlocal handler, so we can expunge the magic buflen hack.

[nss_nonlocal.git] / nonlocal-group.c

diff --git a/nonlocal-group.c b/nonlocal-group.c
index 0dfdb98f75c125ab9927476b1c5eabb30139cb13..c8e8d7b2dbe4315b59824556e9b28014ea163d3a 100644 (file)
--- a/nonlocal-group.c
+++ b/nonlocal-group.c
@@ -41,11 +41,19 @@
 #include "nsswitch-internal.h"
 #include "nonlocal.h"
 
-#define MAGIC_LOCAL_GR_BUFLEN (sysconf(_SC_GETGR_R_SIZE_MAX) + 7)
 #define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
 #define MAGIC_LOCAL_GROUPNAME "nss-local-users"
 
 
+enum nss_status
+_nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
+                        char *buffer, size_t buflen, int *errnop);
+
+enum nss_status
+_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
+                        char *buffer, size_t buflen, int *errnop);
+
+
 static service_user *
 nss_group_nonlocal_database(void)
 {
@@ -60,54 +68,97 @@ nss_group_nonlocal_database(void)
 enum nss_status
 check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
 {
-    enum nss_status status = NSS_STATUS_SUCCESS;
+    static const char *fct_name = "getgrgid_r";
+    static service_user *startp = NULL;
+    static void *fct_start = NULL;
+    enum nss_status status;
+    service_user *nip;
+    union {
+       enum nss_status (*l)(gid_t gid, struct group *grp,
+                            char *buffer, size_t buflen, int *errnop);
+       void *ptr;
+    } fct;
     struct group gbuf;
-    struct group *gbufp = &gbuf;
-    int ret;
     int old_errno = errno;
-    int buflen = MAGIC_LOCAL_GR_BUFLEN;
+
+    int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
     char *buf = malloc(buflen);
     if (buf == NULL) {
        *errnop = ENOMEM;
        errno = old_errno;
        return NSS_STATUS_TRYAGAIN;
     }
-    ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp);
-    if (ret != 0) {
-       *errnop = old_errno;
-       status = NSS_STATUS_TRYAGAIN;
-    } else if (gbufp != NULL) {
+
+    if (fct_start == NULL &&
+       __nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
+       free(buf);
+       return NSS_STATUS_UNAVAIL;
+    }
+    nip = startp;
+    fct.ptr = fct_start;
+    do {
+       if (fct.l == _nss_nonlocal_getgrgid_r)
+           status = NSS_STATUS_NOTFOUND;
+       else
+           status = DL_CALL_FCT(fct.l, (gid, &gbuf, buf, buflen, errnop));
+       if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
+           break;
+    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
+
+    if (status == NSS_STATUS_SUCCESS) {
        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 (status != NSS_STATUS_TRYAGAIN) {
+       status = NSS_STATUS_SUCCESS;
     }
+
     free(buf);
-    errno = old_errno;
     return status;
 }
 
 enum nss_status
 get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen, int *errnop)
 {
-    enum nss_status status = NSS_STATUS_NOTFOUND;
+    static const char *fct_name = "getgrnam_r";
+    static service_user *startp = NULL;
+    static void *fct_start = NULL;
+    enum nss_status status;
+    service_user *nip;
+    union {
+       enum nss_status (*l)(const char *name, struct group *grp,
+                            char *buffer, size_t buflen, int *errnop);
+       void *ptr;
+    } fct;
     struct group gbuf;
-    struct group *gbufp = &gbuf;
-    int ret, n;
+    int n;
     int old_errno = errno;
-    int len = MAGIC_LOCAL_GR_BUFLEN;
+
+    int len = sysconf(_SC_GETGR_R_SIZE_MAX);
     char *buf = malloc(len);
     if (buf == NULL) {
        *errnop = ENOMEM;
        errno = old_errno;
        return NSS_STATUS_TRYAGAIN;
     }
-    ret = getgrnam_r(name, gbufp, buf, len, &gbufp);
-    if (ret != 0) {
-       *errnop = old_errno;
-       status = NSS_STATUS_TRYAGAIN;
-    } else if (gbufp != NULL) {
-       status = NSS_STATUS_SUCCESS;
 
-       n = snprintf(buffer, buflen, "%s", gbufp->gr_name);
+    if (fct_start == NULL &&
+       __nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
+       free(buf);
+       return NSS_STATUS_UNAVAIL;
+    }
+    nip = startp;
+    fct.ptr = fct_start;
+    do {
+       if (fct.l == _nss_nonlocal_getgrnam_r)
+           status = NSS_STATUS_NOTFOUND;
+       else
+           status = DL_CALL_FCT(fct.l, (name, &gbuf, buf, buflen, errnop));
+       if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
+           break;
+    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
+
+    if (status == NSS_STATUS_SUCCESS) {
+       n = snprintf(buffer, buflen, "%s", gbuf.gr_name);
        if (n < 0 || n >= buflen) {
            *errnop = ERANGE;
            status = NSS_STATUS_TRYAGAIN;
@@ -117,7 +168,7 @@ get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen
        buffer += n;
        buflen -= n;
 
-       n = snprintf(buffer, buflen, "%s", gbufp->gr_passwd);
+       n = snprintf(buffer, buflen, "%s", gbuf.gr_passwd);
        if (n < 0 || n >= buflen) {
            *errnop = ERANGE;
            status = NSS_STATUS_TRYAGAIN;
@@ -127,7 +178,7 @@ get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen
        buffer += n;
        buflen -= n;
 
-       grp->gr_gid = gbufp->gr_gid;
+       grp->gr_gid = gbuf.gr_gid;
 
        if (buflen < sizeof(void *)) {
            *errnop = ERANGE;
@@ -138,9 +189,9 @@ get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen
        buffer += sizeof(void *);
        buflen -= sizeof(void *);
     }
+
  get_local_group_done:
     free(buf);
-    errno = old_errno;
     return status;
 }
 
@@ -223,8 +274,7 @@ _nss_nonlocal_getgrent_r(struct group *grp, char *buffer, size_t buflen,
     enum nss_status status;
 
     char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
-    if (buflen == MAGIC_LOCAL_GR_BUFLEN ||
-       (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
+    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
        return NSS_STATUS_UNAVAIL;
 
     if (grent_nip == NULL) {
@@ -269,8 +319,7 @@ _nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
     } fct;
 
     char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
-    if (buflen == MAGIC_LOCAL_GR_BUFLEN ||
-       (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
+    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
        return NSS_STATUS_UNAVAIL;
 
     nip = nss_group_nonlocal_database();
@@ -308,8 +357,7 @@ _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
     } fct;
 
     char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
-    if (buflen == MAGIC_LOCAL_GR_BUFLEN ||
-       (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
+    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
        return NSS_STATUS_UNAVAIL;
 
     nip = nss_group_nonlocal_database();
@@ -356,10 +404,10 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
 
     /* Check that the user is a nonlocal user before adding any groups. */
     status = check_nonlocal_user(user, errnop);
-    if (status == NSS_STATUS_NOTFOUND)
-       is_local = 1;
-    else if (status != NSS_STATUS_SUCCESS)
+    if (status == NSS_STATUS_TRYAGAIN)
        return status;
+    else if (status != NSS_STATUS_SUCCESS)
+       is_local = 1;
 
     int old_errno = errno;
 
@@ -372,14 +420,16 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
     }
     status = get_local_group(MAGIC_LOCAL_GROUPNAME,
                             &local_users_group, buffer, buflen, errnop);
-    if (status == NSS_STATUS_NOTFOUND) {
+    if (status == NSS_STATUS_SUCCESS) {
+       local_users_gid = local_users_group.gr_gid;
+    } else if (status == NSS_STATUS_TRYAGAIN) {
+       free(buffer);
+       return status;
+    } else {
        syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
               MAGIC_LOCAL_GROUPNAME);
        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) {
@@ -394,15 +444,16 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
        }
        status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
                                 &nonlocal_users_group, buffer, buflen, errnop);
-       if (status == NSS_STATUS_NOTFOUND) {
+       if (status == NSS_STATUS_SUCCESS) {
+           gid = nonlocal_users_group.gr_gid;
+       } else if (status == NSS_STATUS_TRYAGAIN) {
+           free(buffer);
+           return status;
+       } else {
            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);
     }
 
@@ -434,8 +485,6 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
        }
     }
 
-    errno = old_errno;
-
     if (is_local)
        return NSS_STATUS_SUCCESS;
 
@@ -478,7 +527,7 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
        status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
        if (status == NSS_STATUS_SUCCESS) {
            (*groupsp)[out++] = (*groupsp)[in];
-       } else if (status != NSS_STATUS_NOTFOUND) {
+       } else if (status == NSS_STATUS_TRYAGAIN) {
            *start = out;
            *errnop = nonlocal_errno;
            return status;