]> andersk Git - nss_nonlocal.git/blobdiff - nonlocal-group.c
Check that a nonlocal lookup by name returns the right name.
[nss_nonlocal.git] / nonlocal-group.c
index 19d3d2c28a003f86295f79134bee2db051096848..83e5d12e385bbe5f8a1a640ed2712f9ded310937 100644 (file)
 #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)
 {
@@ -60,71 +68,120 @@ 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;
+
+    size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
     char *buf = malloc(buflen);
     if (buf == NULL) {
        *errnop = ENOMEM;
        errno = old_errno;
        return NSS_STATUS_TRYAGAIN;
     }
-    errno = 0;
-    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 {
+    morebuf:
+       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) {
+           free(buf);
+           buflen *= 2;
+           buf = malloc(buflen);
+           if (buf == NULL) {
+               *errnop = ENOMEM;
+               errno = old_errno;
+               return NSS_STATUS_TRYAGAIN;
+           }
+           goto morebuf;
+       }
+    } 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)
+get_local_group(const char *name, struct group *grp, char **buffer, int *errnop)
 {
-    enum nss_status status = NSS_STATUS_NOTFOUND;
-    struct group gbuf;
-    struct group *gbufp = &gbuf;
-    int ret;
+    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;
+    size_t buflen;
     int old_errno = errno;
-    int len = MAGIC_LOCAL_GR_BUFLEN;
-    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;
     }
-    errno = 0;
-    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;
-       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);
-       grp->gr_gid = gbufp->gr_gid;
-       if (buflen < sizeof(void *)) {
-           *errnop = ERANGE;
-           status = NSS_STATUS_TRYAGAIN;
-       }
-       else {
-           grp->gr_mem = memset(buffer, 0, sizeof(void *));
+
+    if (fct_start == NULL &&
+       __nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
+       free(*buffer);
+       *buffer = NULL;
+       return NSS_STATUS_UNAVAIL;
+    }
+    nip = startp;
+    fct.ptr = fct_start;
+    do {
+    morebuf:
+       if (fct.l == _nss_nonlocal_getgrnam_r)
+           status = NSS_STATUS_NOTFOUND;
+       else
+           status = DL_CALL_FCT(fct.l, (name, grp, *buffer, buflen, errnop));
+       if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) {
+           free(*buffer);
+           buflen *= 2;
+           *buffer = malloc(buflen);
+           if (*buffer == NULL) {
+               *errnop = ENOMEM;
+               errno = old_errno;
+               return NSS_STATUS_TRYAGAIN;
+           }
+           goto morebuf;
        }
+    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
+
+    if (status != NSS_STATUS_SUCCESS) {
+       free(*buffer);
+       *buffer = NULL;
     }
-    free(buf);
-    errno = old_errno;
+
     return status;
 }
 
@@ -205,6 +262,11 @@ _nss_nonlocal_getgrent_r(struct group *grp, char *buffer, size_t buflen,
                         int *errnop)
 {
     enum nss_status status;
+
+    char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
+       return NSS_STATUS_UNAVAIL;
+
     if (grent_nip == NULL) {
        status = _nss_nonlocal_setgrent(0);
        if (status != NSS_STATUS_SUCCESS)
@@ -246,7 +308,8 @@ _nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
        void *ptr;
     } fct;
 
-    if (buflen == MAGIC_LOCAL_GR_BUFLEN)
+    char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
        return NSS_STATUS_UNAVAIL;
 
     nip = nss_group_nonlocal_database();
@@ -266,6 +329,11 @@ _nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
     if (status != NSS_STATUS_SUCCESS)
        return status;
 
+    if (strcmp(name, grp->gr_name) != 0) {
+       syslog(LOG_ERR, "nss_nonlocal: discarding group %s from lookup for group %s\n", grp->gr_name, name);
+       return NSS_STATUS_NOTFOUND;
+    }
+
     return check_nonlocal_gid(name, grp->gr_gid, errnop);
 }
 
@@ -283,7 +351,8 @@ _nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
        void *ptr;
     } fct;
 
-    if (buflen == MAGIC_LOCAL_GR_BUFLEN)
+    char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
+    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
        return NSS_STATUS_UNAVAIL;
 
     nip = nss_group_nonlocal_database();
@@ -321,51 +390,86 @@ _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;
+    char *buffer;
+    int old_errno;
+    int in, out, i;
 
-    // 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) {
-       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;
+
+    old_errno = errno;
 
-    int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
-    char *buffer = malloc(buflen);
-    if (buffer == NULL) {
-       *errnop = ENOMEM;
-       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) {
+                            &local_users_group, &buffer, errnop);
+    if (status == NSS_STATUS_SUCCESS) {
+       local_users_gid = local_users_group.gr_gid;
+       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 = 0;
+       local_users_gid = -1;
     }
-    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;
+
+    if (is_local) {
+       gid = local_users_gid;
+    } else {
+       status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
+                                &nonlocal_users_group, &buffer, errnop);
+       if (status == NSS_STATUS_SUCCESS) {
+           gid = nonlocal_users_group.gr_gid;
+           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;
        }
     }
-    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, newsize * sizeof((*groupsp)[0]));
+               if (newgroups == NULL) {
+                   *errnop = ENOMEM;
+                   errno = old_errno;
+                   return NSS_STATUS_TRYAGAIN;
+               }
+               *groupsp = newgroups;
+               *size = newsize;
+           }
+           (*groupsp)[(*start)++] = gid;
+       }
     }
 
+    if (is_local)
+       return NSS_STATUS_SUCCESS;
+
+    in = out = *start;
+
     nip = nss_group_nonlocal_database();
     if (nip == NULL)
        return NSS_STATUS_UNAVAIL;
@@ -393,44 +497,23 @@ _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];
-           }
-       } else if (status != NSS_STATUS_NOTFOUND) {
+           (*groupsp)[out++] = (*groupsp)[in];
+       } else if (status == NSS_STATUS_TRYAGAIN) {
            *start = out;
            *errnop = nonlocal_errno;
            return status;
        }
     }
 
-    // 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;
 }
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