diff --git a/src/libnm-client-impl/nm-vpn-service-plugin.c b/src/libnm-client-impl/nm-vpn-service-plugin.c
index 2a217502d..7b04c3079 100644
--- a/src/libnm-client-impl/nm-vpn-service-plugin.c
+++ b/src/libnm-client-impl/nm-vpn-service-plugin.c
@@ -729,54 +729,6 @@ nm_vpn_service_plugin_secrets_required(NMVpnServicePlugin *plugin,
 
 /*****************************************************************************/
 
-typedef struct {
-    char *buf;
-    gsize n_buf;
-    int   fd;
-    bool  eof : 1;
-    char  buf_full[1024];
-} ReadFdBuf;
-
-static inline gboolean
-_read_fd_buf_c(ReadFdBuf *read_buf, char *ch)
-{
-    gssize n_read;
-
-    if (read_buf->n_buf > 0)
-        goto out_data;
-    if (read_buf->eof)
-        return FALSE;
-
-again:
-    n_read = read(read_buf->fd, read_buf->buf_full, sizeof(read_buf->buf_full));
-    if (n_read <= 0) {
-        if (n_read < 0 && errno == EAGAIN) {
-            struct pollfd pfd;
-            int           r;
-
-            memset(&pfd, 0, sizeof(pfd));
-            pfd.fd     = read_buf->fd;
-            pfd.events = POLLIN;
-
-            r = poll(&pfd, 1, -1);
-            if (r > 0)
-                goto again;
-            /* error or timeout. Fall through and set EOF. */
-        }
-        read_buf->eof = TRUE;
-        return FALSE;
-    }
-
-    read_buf->buf   = read_buf->buf_full;
-    read_buf->n_buf = n_read;
-
-out_data:
-    read_buf->n_buf--;
-    *ch = read_buf->buf[0];
-    read_buf->buf++;
-    return TRUE;
-}
-
 #define DATA_KEY_TAG   "DATA_KEY="
 #define DATA_VAL_TAG   "DATA_VAL="
 #define SECRET_KEY_TAG "SECRET_KEY="
@@ -808,7 +760,7 @@ nm_vpn_service_plugin_read_vpn_details(int fd, GHashTable **out_data, GHashTable
     nm_auto_free_gstring GString  *val     = NULL;
     nm_auto_free_gstring GString  *line    = NULL;
     GString                       *str     = NULL;
-    ReadFdBuf                      read_buf;
+    char                           c;
 
     if (out_data)
         g_return_val_if_fail(*out_data == NULL, FALSE);
@@ -819,27 +771,31 @@ nm_vpn_service_plugin_read_vpn_details(int fd, GHashTable **out_data, GHashTable
     secrets =
         g_hash_table_new_full(nm_str_hash, g_str_equal, g_free, (GDestroyNotify) nm_free_secret);
 
-    read_buf.buf   = NULL;
-    read_buf.n_buf = 0;
-    read_buf.fd    = fd;
-    read_buf.eof   = FALSE;
-
     line = g_string_new(NULL);
 
     /* Read stdin for data and secret items until we get a DONE */
     while (1) {
-        gboolean eof;
-        char     c = '\0';
+        ssize_t nr;
 
-        eof = !_read_fd_buf_c(&read_buf, &c);
+        nr = read(fd, &c, 1);
+        if (nr < 0) {
+            if (errno == EAGAIN) {
+                struct pollfd pfd;
+                int           r;
 
-        if (!eof && c == '\0') {
-            /* On the first '\0' char, we also assume the data is finished. Abort. */
-            read_buf.eof = TRUE;
-            eof          = TRUE;
+                memset(&pfd, 0, sizeof(pfd));
+                pfd.fd     = fd;
+                pfd.events = POLLIN;
+
+                r = poll(&pfd, 1, -1);
+                if (r > 0)
+                    continue;
+
+                /* error or timeout. Fall through and break. */
+            }
+            break;
         }
-
-        if (!eof && c != '\n') {
+        if (nr > 0 && c != '\n') {
             g_string_append_c(line, c);
             if (line->len > 512 * 1024) {
                 /* we are about to read a huge line. That is not right, abort. */
@@ -893,7 +849,7 @@ nm_vpn_service_plugin_read_vpn_details(int fd, GHashTable **out_data, GHashTable
 next:
         g_string_truncate(line, 0);
 
-        if (eof)
+        if (nr == 0)
             break;
     }