Fix ldap child memory hierarchy and other issues

The timeout handler was not a child of the request so it could fire even though
the request was already freed.

The code wouldn't use async writes to the children so it could incur in a short
write with no way to detect or recover from it.
Also fixed style of some helper functions to pass explicit paramters instead of
a general structure.
Add common code to do async writes to pipes.
Fixed async write issue for the krb5_child as well.

Fix also sdap_kinit_done(), a return statement was missing and we were mixing
SDAP_AUTH and errno return codes in state->result

Remove usless helper function that just replicates talloc_strndup()

8 files changed, 482 insertions, 306 deletions

diff --git a/server/providers/child_common.c b/server/providers/child_common.c
index 15e0eefe..154f56dd 100644
--- a/server/providers/child_common.c
+++ b/server/providers/child_common.c
@@ -33,23 +33,100 @@
 #include "db/sysdb.h"
 #include "providers/child_common.h"
 
-uint8_t *copy_buffer_and_add_zero(TALLOC_CTX *mem_ctx,
-                                  const uint8_t *src, size_t len)
+/* Async communication with the child process via a pipe */
+
+struct write_pipe_state {
+    int fd;
+    uint8_t *buf;
+    size_t len;
+    size_t written;
+};
+
+static void write_pipe_handler(struct tevent_context *ev,
+                               struct tevent_fd *fde,
+                               uint16_t flags, void *pvt);
+
+struct tevent_req *write_pipe_send(TALLOC_CTX *mem_ctx,
+                                   struct tevent_context *ev,
+                                   uint8_t *buf, size_t len, int fd)
 {
-    uint8_t *str;
+    struct tevent_req *req;
+    struct write_pipe_state *state;
+    struct tevent_fd *fde;
+
+    req = tevent_req_create(mem_ctx, &state, struct write_pipe_state);
+    if (req == NULL) return NULL;
+
+    state->fd = fd;
+    state->buf = buf;
+    state->len = len;
+    state->written = 0;
 
-    str = talloc_size(mem_ctx, len + 1);
-    if (str == NULL) {
-        DEBUG(1, ("talloc_size failed.\n"));
-        return NULL;
+    fde = tevent_add_fd(ev, state, fd, TEVENT_FD_WRITE,
+                        write_pipe_handler, req);
+    if (fde == NULL) {
+        DEBUG(1, ("tevent_add_fd failed.\n"));
+        goto fail;
     }
-    memcpy(str, src, len);
-    str[len] = '\0';
 
-    return str;
+    return req;
+
+fail:
+    talloc_zfree(req);
+    return NULL;
 }
 
-/* Async communication with the child process via a pipe */
+static void write_pipe_handler(struct tevent_context *ev,
+                               struct tevent_fd *fde,
+                               uint16_t flags, void *pvt)
+{
+    struct tevent_req *req = talloc_get_type(pvt, struct tevent_req);
+    struct write_pipe_state *state = tevent_req_data(req,
+                                                     struct write_pipe_state);
+    ssize_t size;
+
+    if (flags & TEVENT_FD_READ) {
+        DEBUG(1, ("write_pipe_done called with TEVENT_FD_READ,"
+                  " this should not happen.\n"));
+        tevent_req_error(req, EINVAL);
+        return;
+    }
+
+    size = write(state->fd,
+                 state->buf + state->written,
+                 state->len - state->written);
+    if (size == -1) {
+        if (errno == EAGAIN || errno == EINTR) return;
+        DEBUG(1, ("write failed [%d][%s].\n", errno, strerror(errno)));
+        tevent_req_error(req, errno);
+        return;
+
+    } else if (size >= 0) {
+        state->written += size;
+        if (state->written > state->len) {
+            DEBUG(1, ("write to much, this should never happen.\n"));
+            tevent_req_error(req, EINVAL);
+            return;
+        }
+    } else {
+        DEBUG(1, ("unexpected return value of write [%d].\n", size));
+        tevent_req_error(req, EINVAL);
+        return;
+    }
+
+    if (state->len == state->written) {
+        DEBUG(6, ("All data has been sent!\n"));
+        tevent_req_done(req);
+        return;
+    }
+}
+
+int write_pipe_recv(struct tevent_req *req)
+{
+    TEVENT_REQ_RETURN_ON_ERROR(req);
+
+    return EOK;
+}
 
 struct read_pipe_state {
     int fd;
@@ -57,9 +134,9 @@ struct read_pipe_state {
     size_t len;
 };
 
-static void read_pipe_done(struct tevent_context *ev,
-                           struct tevent_fd *fde,
-                           uint16_t flags, void *pvt);
+static void read_pipe_handler(struct tevent_context *ev,
+                              struct tevent_fd *fde,
+                              uint16_t flags, void *pvt);
 
 struct tevent_req *read_pipe_send(TALLOC_CTX *mem_ctx,
                                   struct tevent_context *ev, int fd)
@@ -77,7 +154,7 @@ struct tevent_req *read_pipe_send(TALLOC_CTX *mem_ctx,
     if (state->buf == NULL) goto fail;
 
     fde = tevent_add_fd(ev, state, fd, TEVENT_FD_READ,
-                        read_pipe_done, req);
+                        read_pipe_handler, req);
     if (fde == NULL) {
         DEBUG(1, ("tevent_add_fd failed.\n"));
         goto fail;
@@ -90,37 +167,49 @@ fail:
     return NULL;
 }
 
-static void read_pipe_done(struct tevent_context *ev,
-                           struct tevent_fd *fde,
-                           uint16_t flags, void *pvt)
+static void read_pipe_handler(struct tevent_context *ev,
+                              struct tevent_fd *fde,
+                              uint16_t flags, void *pvt)
 {
-    ssize_t size;
     struct tevent_req *req = talloc_get_type(pvt, struct tevent_req);
-    struct read_pipe_state *state = tevent_req_data(req, struct read_pipe_state);
+    struct read_pipe_state *state = tevent_req_data(req,
+                                                    struct read_pipe_state);
+    ssize_t size;
+    errno_t err;
 
     if (flags & TEVENT_FD_WRITE) {
-        DEBUG(1, ("read_pipe_done called with TEVENT_FD_WRITE, this should not happen.\n"));
+        DEBUG(1, ("read_pipe_done called with TEVENT_FD_WRITE,"
+                  " this should not happen.\n"));
         tevent_req_error(req, EINVAL);
         return;
     }
 
-    size = read(state->fd, state->buf + state->len, talloc_get_size(state->buf) - state->len);
+    size = read(state->fd,
+                state->buf + state->len,
+                MAX_CHILD_MSG_SIZE - state->len);
     if (size == -1) {
-        if (errno == EAGAIN || errno == EINTR) return;
-        DEBUG(1, ("read failed [%d][%s].\n", errno, strerror(errno)));
-        tevent_req_error(req, errno);
+        err = errno;
+        if (err == EAGAIN || err == EINTR) {
+            return;
+        }
+
+        DEBUG(1, ("read failed [%d][%s].\n", err, strerror(err)));
+        tevent_req_error(req, err);
         return;
+
     } else if (size > 0) {
         state->len += size;
-        if (state->len > talloc_get_size(state->buf)) {
+        if (state->len > MAX_CHILD_MSG_SIZE) {
             DEBUG(1, ("read to much, this should never happen.\n"));
             tevent_req_error(req, EINVAL);
             return;
         }
-        return;
+
     } else if (size == 0) {
+        DEBUG(6, ("EOF received, client finished\n"));
         tevent_req_done(req);
         return;
+
     } else {
         DEBUG(1, ("unexpected return value of read [%d].\n", size));
         tevent_req_error(req, EINVAL);
@@ -131,12 +220,12 @@ static void read_pipe_done(struct tevent_context *ev,
 int read_pipe_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
                    uint8_t **buf, ssize_t *len)
 {
-    struct read_pipe_state *state = tevent_req_data(req,
-                                                    struct read_pipe_state);
+    struct read_pipe_state *state;
+    state = tevent_req_data(req, struct read_pipe_state);
 
     TEVENT_REQ_RETURN_ON_ERROR(req);
 
-    *buf = talloc_move(mem_ctx, &state->buf);
+    *buf = talloc_steal(mem_ctx, state->buf);
     *len = state->len;
 
     return EOK;
diff --git a/server/providers/child_common.h b/server/providers/child_common.h
index 894255b5..a441df3c 100644
--- a/server/providers/child_common.h
+++ b/server/providers/child_common.h
@@ -46,15 +46,14 @@ struct io_buffer {
     size_t size;
 };
 
-uint8_t *copy_buffer_and_add_zero(TALLOC_CTX *mem_ctx,
-                                  const uint8_t *src, size_t len);
-
 /* Async communication with the child process via a pipe */
-struct read_pipe_state;
+struct tevent_req *write_pipe_send(TALLOC_CTX *mem_ctx,
+                                   struct tevent_context *ev,
+                                   uint8_t *buf, size_t len, int fd);
+int write_pipe_recv(struct tevent_req *req);
 
 struct tevent_req *read_pipe_send(TALLOC_CTX *mem_ctx,
                                   struct tevent_context *ev, int fd);
-
 int read_pipe_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
                    uint8_t **buf, ssize_t *len);
 
diff --git a/server/providers/krb5/krb5_auth.c b/server/providers/krb5/krb5_auth.c
index 71f4b919..74981b19 100644
--- a/server/providers/krb5/krb5_auth.c
+++ b/server/providers/krb5/krb5_auth.c
@@ -575,56 +575,86 @@ static errno_t fork_child(struct krb5child_req *kr)
 }
 
 struct handle_child_state {
+    struct tevent_context *ev;
     struct krb5child_req *kr;
-    ssize_t len;
     uint8_t *buf;
+    ssize_t len;
 };
 
+static void handle_child_step(struct tevent_req *subreq);
 static void handle_child_done(struct tevent_req *subreq);
 
 static struct tevent_req *handle_child_send(TALLOC_CTX *mem_ctx,
                                             struct tevent_context *ev,
                                             struct krb5child_req *kr)
 {
-    int ret;
-    struct tevent_req *req;
-    struct tevent_req *subreq;
+    struct tevent_req *req, *subreq;
     struct handle_child_state *state;
     struct io_buffer *buf;
+    int ret;
+
+    req = tevent_req_create(mem_ctx, &state, struct handle_child_state);
+    if (req == NULL) {
+        return NULL;
+    }
+
+    state->ev = ev;
+    state->kr = kr;
+    state->buf = NULL;
+    state->len = 0;
 
     ret = create_send_buffer(kr, &buf);
     if (ret != EOK) {
         DEBUG(1, ("create_send_buffer failed.\n"));
-        return NULL;
+        goto fail;
     }
 
     ret = fork_child(kr);
     if (ret != EOK) {
         DEBUG(1, ("fork_child failed.\n"));
-        return NULL;
+        goto fail;
     }
 
-    ret = write(kr->write_to_child_fd, buf->data, buf->size);
-    close(kr->write_to_child_fd);
-    kr->write_to_child_fd = -1;
-    if (ret == -1) {
-        DEBUG(1, ("write failed [%d][%s].\n", errno, strerror(errno)));
-        return NULL;
+    subreq = write_pipe_send(state, ev, buf->data, buf->size,
+                             kr->write_to_child_fd);
+    if (!subreq) {
+        ret = ENOMEM;
+        goto fail;
     }
+    tevent_req_set_callback(subreq, handle_child_step, req);
 
-    req = tevent_req_create(mem_ctx, &state, struct handle_child_state);
-    if (req == NULL) {
-        return NULL;
+    return req;
+
+fail:
+    tevent_req_error(req, ret);
+    tevent_req_post(req, ev);
+    return req;
+}
+
+static void handle_child_step(struct tevent_req *subreq)
+{
+    struct tevent_req *req = tevent_req_callback_data(subreq,
+                                                      struct tevent_req);
+    struct handle_child_state *state = tevent_req_data(req,
+                                                    struct handle_child_state);
+    int ret;
+
+    ret = write_pipe_recv(subreq);
+    talloc_zfree(subreq);
+    if (ret != EOK) {
+        tevent_req_error(req, ret);
+        return;
     }
 
-    state->kr = kr;
+    close(state->kr->write_to_child_fd);
+    state->kr->write_to_child_fd = -1;
 
-    subreq = read_pipe_send(state, ev, kr->read_from_child_fd);
-    if (tevent_req_nomem(subreq, req)) {
-        return tevent_req_post(req, ev);
+    subreq = read_pipe_send(state, state->ev, state->kr->read_from_child_fd);
+    if (!subreq) {
+        tevent_req_error(req, ENOMEM);
+        return;
     }
     tevent_req_set_callback(subreq, handle_child_done, req);
-    return req;
 }
 
 static void handle_child_done(struct tevent_req *subreq)
@@ -637,14 +667,14 @@ static void handle_child_done(struct tevent_req *subreq)
 
     ret = read_pipe_recv(subreq, state, &state->buf, &state->len);
     talloc_zfree(subreq);
-    talloc_zfree(state->kr->timeout_handler);
-    close(state->kr->read_from_child_fd);
-    state->kr->read_from_child_fd = -1;
     if (ret != EOK) {
         tevent_req_error(req, ret);
         return;
     }
 
+    close(state->kr->read_from_child_fd);
+    state->kr->read_from_child_fd = -1;
+
     tevent_req_done(req);
     return;
 }
@@ -961,6 +991,7 @@ static void krb5_child_done(struct tevent_req *req)
     int dp_err = DP_ERR_FATAL;
 
     ret = handle_child_recv(req, pd, &buf, &len);
+    talloc_zfree(kr->timeout_handler);
     talloc_zfree(req);
     if (ret != EOK) {
         DEBUG(1, ("child failed (%d [%s])\n", ret, strerror(ret)));
diff --git a/server/providers/krb5/krb5_child.c b/server/providers/krb5/krb5_child.c
index 6eb420bc..6b4c7cc0 100644
--- a/server/providers/krb5/krb5_child.c
+++ b/server/providers/krb5/krb5_child.c
@@ -339,8 +339,9 @@ static struct response *prepare_response_message(struct krb5_req *kr,
 static errno_t sendresponse(int fd, krb5_error_code kerr, int pam_status,
                             struct krb5_req *kr)
 {
-    int ret;
     struct response *resp;
+    size_t written;
+    int ret;
 
     resp = prepare_response_message(kr, kerr, pam_status);
     if (resp == NULL) {
@@ -348,10 +349,18 @@ static errno_t sendresponse(int fd, krb5_error_code kerr, int pam_status,
         return ENOMEM;
     }
 
-    ret = write(fd, resp->buf, resp->size);
-    if (ret == -1) {
-        DEBUG(1, ("write failed [%d][%s].\n", errno, strerror(errno)));
-        return errno;
+    written = 0;
+    while (written < resp->size) {
+        ret = write(fd, resp->buf + written, resp->size - written);
+        if (ret == -1) {
+            if (errno == EAGAIN || errno == EINTR) {
+                continue;
+            }
+            ret = errno;
+            DEBUG(1, ("write failed [%d][%s].\n", ret, strerror(ret)));
+            return ret;
+        }
+        written += ret;
     }
 
     return EOK;
@@ -680,79 +689,71 @@ static errno_t unpack_buffer(uint8_t *buf, size_t size, struct pam_data *pd,
                              char **ccname, char **keytab, uint32_t *validate)
 {
     size_t p = 0;
-    uint32_t *len;
+    uint32_t len;
 
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
-    pd->cmd = *len;
+    pd->cmd = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
-    pd->pw_uid = *len;
+    pd->pw_uid = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
-    pd->gr_gid = *len;
+    pd->gr_gid = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
-    *validate = *len;
+    *validate = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
+    len = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
-    if ((p + *len ) > size) return EINVAL;
-    pd->upn = (char *) copy_buffer_and_add_zero(pd, buf+p,
-                                                sizeof(char) * (*len));
+    if ((p + len ) > size) return EINVAL;
+    pd->upn = talloc_strndup(pd, (char *)(buf + p), len);
     if (pd->upn == NULL) return ENOMEM;
-    p += *len;
+    p += len;
 
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
+    len = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
-    if ((p + *len ) > size) return EINVAL;
-    *ccname = (char *) copy_buffer_and_add_zero(pd, buf+p,
-                                                sizeof(char) * (*len));
+    if ((p + len ) > size) return EINVAL;
+    *ccname = talloc_strndup(pd, (char *)(buf + p), len);
     if (*ccname == NULL) return ENOMEM;
-    p += *len;
+    p += len;
 
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
+    len = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
-    if ((p + *len ) > size) return EINVAL;
-    *keytab = (char *) copy_buffer_and_add_zero(pd, buf+p,
-                                                sizeof(char) * (*len));
+    if ((p + len ) > size) return EINVAL;
+    *keytab = talloc_strndup(pd, (char *)(buf + p), len);
     if (*keytab == NULL) return ENOMEM;
-    p += *len;
+    p += len;
 
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
+    len = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
-    if ((p + *len) > size) return EINVAL;
-    pd->authtok = copy_buffer_and_add_zero(pd, buf+p, sizeof(char) * (*len));
+    if ((p + len) > size) return EINVAL;
+    pd->authtok = (uint8_t *)talloc_strndup(pd, (char *)(buf + p), len);
     if (pd->authtok == NULL) return ENOMEM;
-    pd->authtok_size = *len + 1;
-    p += *len;
+    pd->authtok_size = len + 1;
+    p += len;
 
     if (pd->cmd == SSS_PAM_CHAUTHTOK) {
         if ((p + sizeof(uint32_t)) > size) return EINVAL;
-        len = ((uint32_t *)(buf+p));
+        len = *((uint32_t *)(buf + p));
         p += sizeof(uint32_t);
 
-        if ((p + *len) > size) return EINVAL;
-        pd->newauthtok = copy_buffer_and_add_zero(pd, buf+p,
-                                                  sizeof(char) * (*len));
+        if ((p + len) > size) return EINVAL;
+        pd->newauthtok = (uint8_t *)talloc_strndup(pd, (char *)(buf + p), len);
         if (pd->newauthtok == NULL) return ENOMEM;
-        pd->newauthtok_size = *len + 1;
-        p += *len;
+        pd->newauthtok_size = len + 1;
+        p += len;
     } else {
         pd->newauthtok = NULL;
         pd->newauthtok_size = 0;
@@ -938,6 +939,8 @@ int main(int argc, const char *argv[])
 
     poptFreeContext(pc);
 
+    DEBUG(7, ("krb5_child started.\n"));
+
     pd = talloc(NULL, struct pam_data);
     if (pd == NULL) {
         DEBUG(1, ("malloc failed.\n"));
diff --git a/server/providers/ldap/ldap_child.c b/server/providers/ldap/ldap_child.c
index 9c11bf40..4a577b87 100644
--- a/server/providers/ldap/ldap_child.c
+++ b/server/providers/ldap/ldap_child.c
@@ -42,10 +42,11 @@ struct input_buffer {
     const char *keytab_name;
 };
 
-static errno_t unpack_buffer(uint8_t *buf, size_t size, struct input_buffer *ibuf)
+static errno_t unpack_buffer(uint8_t *buf, size_t size,
+                             struct input_buffer *ibuf)
 {
     size_t p = 0;
-    uint32_t *len;
+    uint32_t len;
 
     /* realm_str size and length */
     DEBUG(7, ("total buffer size: %d\n", size));
@@ -53,47 +54,44 @@ static errno_t unpack_buffer(uint8_t *buf, size_t size, struct input_buffer *ibu
         DEBUG(1, ("Error: buffer too big!\n"));
         return EINVAL;
     }
-    len = ((uint32_t *)(buf+p));
+    len = ((uint32_t *)(buf + p))[0];
     p += sizeof(uint32_t);
 
-    DEBUG(7, ("realm_str size: %d\n", *len));
-    if (*len) {
-        if ((p + *len ) > size) return EINVAL;
-        ibuf->realm_str = (char *) copy_buffer_and_add_zero(ibuf, buf+p,
-                                                 sizeof(char) * (*len));
+    DEBUG(7, ("realm_str size: %d\n", len));
+    if (len) {
+        if ((p + len ) > size) return EINVAL;
+        ibuf->realm_str = talloc_strndup(ibuf, (char *)(buf + p), len);
         DEBUG(7, ("got realm_str: %s\n", ibuf->realm_str));
         if (ibuf->realm_str == NULL) return ENOMEM;
-        p += *len;
+        p += len;
     }
 
     /* princ_str size and length */
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
+    len = ((uint32_t *)(buf + p))[0];
     p += sizeof(uint32_t);
 
-    DEBUG(7, ("princ_str size: %d\n", *len));
-    if (*len) {
-        if ((p + *len ) > size) return EINVAL;
-        ibuf->princ_str = (char *) copy_buffer_and_add_zero(ibuf, buf+p,
-                                                  sizeof(char) * (*len));
+    DEBUG(7, ("princ_str size: %d\n", len));
+    if (len) {
+        if ((p + len ) > size) return EINVAL;
+        ibuf->princ_str = talloc_strndup(ibuf, (char *)(buf + p), len);
         DEBUG(7, ("got princ_str: %s\n", ibuf->princ_str));
         if (ibuf->princ_str == NULL) return ENOMEM;
-        p += *len;
+        p += len;
     }
 
     /* keytab_name size and length */
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
+    len = ((uint32_t *)(buf + p))[0];
     p += sizeof(uint32_t);
 
-    DEBUG(7, ("keytab_name size: %d\n", *len));
-    if (*len) {
-        if ((p + *len ) > size) return EINVAL;
-        ibuf->keytab_name = (char *) copy_buffer_and_add_zero(ibuf, buf+p,
-                                                    sizeof(char) * (*len));
+    DEBUG(7, ("keytab_name size: %d\n", len));
+    if (len) {
+        if ((p + len ) > size) return EINVAL;
+        ibuf->keytab_name = talloc_strndup(ibuf, (char *)(buf + p), len);
         DEBUG(7, ("got keytab_name: %s\n", ibuf->keytab_name));
         if (ibuf->keytab_name == NULL) return ENOMEM;
-        p += *len;
+        p += len;
     }
 
     return EOK;
@@ -321,6 +319,7 @@ int main(int argc, const char *argv[])
     const char *ccname = NULL;
     struct input_buffer *ibuf = NULL;
     struct response *resp = NULL;
+    size_t written;
 
     struct poptOption long_options[] = {
         POPT_AUTOHELP
@@ -346,6 +345,8 @@ int main(int argc, const char *argv[])
 
     poptFreeContext(pc);
 
+    DEBUG(7, ("ldap_child started.\n"));
+
     main_ctx = talloc_new(NULL);
     if (main_ctx == NULL) {
         DEBUG(1, ("talloc_new failed.\n"));
@@ -414,11 +415,18 @@ int main(int argc, const char *argv[])
         return ENOMEM;
     }
 
-    ret = write(STDOUT_FILENO, resp->buf, resp->size);
-    if (ret == -1) {
-        ret = errno;
-        DEBUG(1, ("write failed [%d][%s].\n", ret, strerror(ret)));
-        return errno;
+    written = 0;
+    while (written < resp->size) {
+        ret = write(STDOUT_FILENO, resp->buf + written, resp->size - written);
+        if (ret == -1) {
+            if (errno == EAGAIN || errno == EINTR) {
+                continue;
+            }
+            ret = errno;
+            DEBUG(1, ("write failed [%d][%s].\n", ret, strerror(ret)));
+            return ret;
+        }
+        written += ret;
     }
 
     close(STDOUT_FILENO);
diff --git a/server/providers/ldap/sdap_async_connection.c b/server/providers/ldap/sdap_async_connection.c
index 13497903..7ccb301b 100644
--- a/server/providers/ldap/sdap_async_connection.c
+++ b/server/providers/ldap/sdap_async_connection.c
@@ -581,8 +581,7 @@ struct tevent_req *sdap_kinit_send(TALLOC_CTX *memctx,
         }
     }
 
-    subreq = sdap_krb5_get_tgt_send(state, ev, timeout,
-                                    realm, principal, keytab);
+    subreq = sdap_get_tgt_send(state, ev, realm, principal, keytab, timeout);
     if (!subreq) {
         talloc_zfree(req);
         return NULL;
@@ -603,19 +602,20 @@ static void sdap_kinit_done(struct tevent_req *subreq)
     int result;
     char *ccname = NULL;
 
-    ret = sdap_krb5_get_tgt_recv(subreq, state, &result, &ccname);
+    ret = sdap_get_tgt_recv(subreq, state, &result, &ccname);
     talloc_zfree(subreq);
     if (ret != EOK) {
-        state->result = ret;
+        state->result = SDAP_AUTH_FAILED;
         DEBUG(1, ("child failed (%d [%s])\n", ret, strerror(ret)));
         tevent_req_error(req, ret);
+        return;
     }
 
     if (result == EOK) {
         ret = setenv("KRB5CCNAME", ccname, 1);
         if (ret == -1) {
             DEBUG(2, ("Unable to set env. variable KRB5CCNAME!\n"));
-            state->result = EFAULT;
+            state->result = SDAP_AUTH_FAILED;
             tevent_req_error(req, EFAULT);
         }
 
diff --git a/server/providers/ldap/sdap_async_private.h b/server/providers/ldap/sdap_async_private.h
index af8d2b8e..9237f15d 100644
--- a/server/providers/ldap/sdap_async_private.h
+++ b/server/providers/ldap/sdap_async_private.h
@@ -44,16 +44,16 @@ int sdap_get_rootdse_recv(struct tevent_req *req,
 
 /* from sdap_child_helpers.c */
 
-struct tevent_req *sdap_krb5_get_tgt_send(TALLOC_CTX *mem_ctx,
-                                          struct tevent_context *ev,
-                                          int timeout,
-                                          const char *realm_str,
-                                          const char *princ_str,
-                                          const char *keytab_name);
-
-int sdap_krb5_get_tgt_recv(struct tevent_req *req,
-                           TALLOC_CTX *mem_ctx,
-                           int  *result,
-                           char **ccname);
+struct tevent_req *sdap_get_tgt_send(TALLOC_CTX *mem_ctx,
+                                     struct tevent_context *ev,
+                                     const char *realm_str,
+                                     const char *princ_str,
+                                     const char *keytab_name,
+                                     int timeout);
+
+int sdap_get_tgt_recv(struct tevent_req *req,
+                      TALLOC_CTX *mem_ctx,
+                      int  *result,
+                      char **ccname);
 
 #endif /* _SDAP_ASYNC_PRIVATE_H_ */
diff --git a/server/providers/ldap/sdap_child_helpers.c b/server/providers/ldap/sdap_child_helpers.c
index 0972ec72..862dacf9 100644
--- a/server/providers/ldap/sdap_child_helpers.c
+++ b/server/providers/ldap/sdap_child_helpers.c
@@ -42,76 +42,42 @@
 #define LDAP_CHILD_USER  "nobody"
 #endif
 
-struct sdap_child_req {
+struct sdap_child {
     /* child info */
-    pid_t child_pid;
+    pid_t pid;
     int read_from_child_fd;
     int write_to_child_fd;
-
-    /* for handling timeout */
-    struct tevent_context *ev;
-    int timeout;
-    struct tevent_timer *timeout_handler;
-    struct tevent_req *req;
-
-    /* parameters */
-    const char *realm_str;
-    const char *princ_str;
-    const char *keytab_name;
 };
 
-static int sdap_child_req_destructor(void *ptr)
-{
-    struct sdap_child_req *cr = talloc_get_type(ptr, struct sdap_child_req);
-
-    if (cr == NULL) return EOK;
-
-    child_cleanup(cr->read_from_child_fd, cr->write_to_child_fd);
-    memset(cr, 0, sizeof(struct sdap_child_req));
-
-    return EOK;
-}
-
-static void sdap_child_timeout(struct tevent_context *ev,
-                               struct tevent_timer *te,
-                               struct timeval tv, void *pvt)
+static void sdap_close_fd(int *fd)
 {
-    struct sdap_child_req *lr = talloc_get_type(pvt, struct sdap_child_req);
     int ret;
 
-    if (lr->timeout_handler == NULL) {
+    if (*fd == -1) {
+        DEBUG(6, ("fd already closed\n"));
         return;
     }
 
-    DEBUG(9, ("timeout for ldap child [%d] reached.\n", lr->child_pid));
-
-    ret = kill(lr->child_pid, SIGKILL);
-    if (ret == -1) {
-        DEBUG(1, ("kill failed [%d][%s].\n", errno, strerror(errno)));
+    ret = close(*fd);
+    if (ret) {
+        ret = errno;
+        DEBUG(2, ("Closing fd %d, return error %d (%s)\n",
+                  *fd, ret, strerror(ret)));
     }
 
-    tevent_req_error(lr->req, EIO);
+    *fd = -1;
 }
 
-static errno_t activate_child_timeout_handler(struct sdap_child_req *child_req)
+static int sdap_child_destructor(void *ptr)
 {
-    struct timeval tv;
+    struct sdap_child *child = talloc_get_type(ptr, struct sdap_child);
 
-    tv = tevent_timeval_current();
-    tv = tevent_timeval_add(&tv,
-                            child_req->timeout,
-                            0);
-    child_req->timeout_handler = tevent_add_timer(child_req->ev, child_req, tv,
-                                                  sdap_child_timeout, child_req);
-    if (child_req->timeout_handler == NULL) {
-        DEBUG(1, ("tevent_add_timer failed.\n"));
-        return ENOMEM;
-    }
+    child_cleanup(child->read_from_child_fd, child->write_to_child_fd);
 
-    return EOK;
+    return 0;
 }
 
-static errno_t fork_ldap_child(struct sdap_child_req *child_req)
+static errno_t sdap_fork_child(struct sdap_child *child)
 {
     int pipefd_to_child[2];
     int pipefd_from_child[2];
@@ -135,7 +101,7 @@ static errno_t fork_ldap_child(struct sdap_child_req *child_req)
     pid = fork();
 
     if (pid == 0) { /* child */
-        err = exec_child(child_req,
+        err = exec_child(child,
                          pipefd_to_child, pipefd_from_child,
                          LDAP_CHILD, ldap_child_debug_fd);
         if (err != EOK) {
@@ -144,13 +110,13 @@ static errno_t fork_ldap_child(struct sdap_child_req *child_req)
             return err;
         }
     } else if (pid > 0) { /* parent */
-        child_req->child_pid = pid;
-        child_req->read_from_child_fd = pipefd_from_child[0];
+        child->pid = pid;
+        child->read_from_child_fd = pipefd_from_child[0];
         close(pipefd_from_child[1]);
-        child_req->write_to_child_fd = pipefd_to_child[1];
+        child->write_to_child_fd = pipefd_to_child[1];
         close(pipefd_to_child[0]);
-        fd_nonblocking(child_req->read_from_child_fd);
-        fd_nonblocking(child_req->write_to_child_fd);
+        fd_nonblocking(child->read_from_child_fd);
+        fd_nonblocking(child->write_to_child_fd);
 
     } else { /* error */
         err = errno;
@@ -161,27 +127,36 @@ static errno_t fork_ldap_child(struct sdap_child_req *child_req)
     return EOK;
 }
 
-static errno_t create_ldap_send_buffer(struct sdap_child_req *child_req, struct io_buffer **io_buf)
+static errno_t create_tgt_req_send_buffer(TALLOC_CTX *mem_ctx,
+                                          const char *realm_str,
+                                          const char *princ_str,
+                                          const char *keytab_name,
+                                          struct io_buffer **io_buf)
 {
     struct io_buffer *buf;
     size_t rp;
+    int len;
 
-    buf = talloc(child_req, struct io_buffer);
+    buf = talloc(mem_ctx, struct io_buffer);
     if (buf == NULL) {
         DEBUG(1, ("talloc failed.\n"));
         return ENOMEM;
     }
 
-    buf->size = 3*sizeof(int);
-    if (child_req->realm_str)
-        buf->size += strlen(child_req->realm_str);
-    if (child_req->princ_str)
-        buf->size += strlen(child_req->princ_str);
-    if (child_req->keytab_name)
-        buf->size += strlen(child_req->keytab_name);
+    buf->size = 3 * sizeof(uint32_t);
+    if (realm_str) {
+        buf->size += strlen(realm_str);
+    }
+    if (princ_str) {
+        buf->size += strlen(princ_str);
+    }
+    if (keytab_name) {
+        buf->size += strlen(keytab_name);
+    }
+
     DEBUG(7, ("buffer size: %d\n", buf->size));
 
-    buf->data = talloc_size(child_req, buf->size);
+    buf->data = talloc_size(buf, buf->size);
     if (buf->data == NULL) {
         DEBUG(1, ("talloc_size failed.\n"));
         talloc_free(buf);
@@ -189,34 +164,41 @@ static errno_t create_ldap_send_buffer(struct sdap_child_req *child_req, struct
     }
 
     rp = 0;
+
     /* realm */
-    ((uint32_t *)(&buf->data[rp]))[0] =
-                        (uint32_t) (child_req->realm_str ?
-                                   strlen(child_req->realm_str) : 0);
-    rp += sizeof(uint32_t);
-    if (child_req->realm_str) {
-        memcpy(&buf->data[rp], child_req->realm_str, strlen(child_req->realm_str));
-        rp += strlen(child_req->realm_str);
+    if (realm_str) {
+        len = strlen(realm_str);
+        ((uint32_t *)(&buf->data[rp]))[0] = len;
+        rp += sizeof(uint32_t);
+        memcpy(&buf->data[rp], realm_str, len);
+        rp += len;
+    } else {
+        ((uint32_t *)(&buf->data[rp]))[0] = 0;
+        rp += sizeof(uint32_t);
     }
 
     /* principal */
-    ((uint32_t *)(&buf->data[rp]))[0] =
-                        (uint32_t) (child_req->princ_str ?
-                                   strlen(child_req->princ_str) : 0);
-    rp += sizeof(uint32_t);
-    if (child_req->princ_str) {
-        memcpy(&buf->data[rp], child_req->princ_str, strlen(child_req->princ_str));
-        rp += strlen(child_req->princ_str);
+    if (princ_str) {
+        len = strlen(princ_str);
+        ((uint32_t *)(&buf->data[rp]))[0] = len;
+        rp += sizeof(uint32_t);
+        memcpy(&buf->data[rp], princ_str, len);
+        rp += len;
+    } else {
+        ((uint32_t *)(&buf->data[rp]))[0] = 0;
+        rp += sizeof(uint32_t);
     }
 
     /* keytab */
-    ((uint32_t *)(&buf->data[rp]))[0] =
-                        (uint32_t) (child_req->keytab_name ?
-                                   strlen(child_req->keytab_name) : 0);
-    rp += sizeof(uint32_t);
-    if (child_req->keytab_name) {
-        memcpy(&buf->data[rp], child_req->keytab_name, strlen(child_req->keytab_name));
-        rp += strlen(child_req->keytab_name);
+    if (keytab_name) {
+        len = strlen(keytab_name);
+        ((uint32_t *)(&buf->data[rp]))[0] = len;
+        rp += sizeof(uint32_t);
+        memcpy(&buf->data[rp], keytab_name, len);
+        rp += len;
+    } else {
+        ((uint32_t *)(&buf->data[rp]))[0] = 0;
+        rp += sizeof(uint32_t);
     }
 
     *io_buf = buf;
@@ -225,151 +207,172 @@ static errno_t create_ldap_send_buffer(struct sdap_child_req *child_req, struct
 
 static int parse_child_response(TALLOC_CTX *mem_ctx,
                                 uint8_t *buf, ssize_t size,
-                                int  *result,
-                                char **ccache)
+                                int  *result, char **ccache)
 {
     size_t p = 0;
-    uint32_t *len;
-    uint32_t *res;
+    uint32_t len;
+    uint32_t res;
     char *ccn;
 
-    /* ccache size the ccache itself*/
+    /* operatoin result code */
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    res = ((uint32_t *)(buf+p));
+    res = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
-    /* ccache size the ccache itself*/
+    /* ccache name size */
     if ((p + sizeof(uint32_t)) > size) return EINVAL;
-    len = ((uint32_t *)(buf+p));
+    len = *((uint32_t *)(buf + p));
     p += sizeof(uint32_t);
 
-    if ((p + *len ) > size) return EINVAL;
+    if ((p + len ) > size) return EINVAL;
 
-    ccn = talloc_size(mem_ctx, sizeof(char) * (*len + 1));
+    ccn = talloc_size(mem_ctx, sizeof(char) * (len + 1));
     if (ccn == NULL) {
         DEBUG(1, ("talloc_size failed.\n"));
         return ENOMEM;
     }
-    memcpy(ccn, buf+p, sizeof(char) * (*len + 1));
-    ccn[*len] = '\0';
+    memcpy(ccn, buf+p, sizeof(char) * (len + 1));
+    ccn[len] = '\0';
 
-    *result = *res;
+    *result = res;
     *ccache = ccn;
     return EOK;
 }
 
 /* ==The-public-async-interface============================================*/
 
-struct sdap_krb5_get_tgt_state {
-    struct sdap_child_req *lr;
+struct sdap_get_tgt_state {
+    struct tevent_context *ev;
+    struct sdap_child *child;
     ssize_t len;
     uint8_t *buf;
 };
 
-static void sdap_krb5_get_tgt_done(struct tevent_req *subreq);
-
-struct tevent_req *sdap_krb5_get_tgt_send(TALLOC_CTX *mem_ctx,
-                                          struct tevent_context *ev,
-                                          int timeout,
-                                          const char *realm_str,
-                                          const char *princ_str,
-                                          const char *keytab_name)
+static errno_t set_tgt_child_timeout(struct tevent_req *req,
+                                     struct tevent_context *ev,
+                                     int timeout);
+static void sdap_get_tgt_step(struct tevent_req *subreq);
+static void sdap_get_tgt_done(struct tevent_req *subreq);
+
+struct tevent_req *sdap_get_tgt_send(TALLOC_CTX *mem_ctx,
+                                     struct tevent_context *ev,
+                                     const char *realm_str,
+                                     const char *princ_str,
+                                     const char *keytab_name,
+                                     int timeout)
 {
-    struct sdap_child_req *child_req = NULL;
-    struct sdap_krb5_get_tgt_state *state = NULL;
+    struct tevent_req *req, *subreq;
+    struct sdap_get_tgt_state *state;
+    struct io_buffer *buf;
     int ret;
-    struct io_buffer *buf = NULL;
-    struct tevent_req *req = NULL;
-    struct tevent_req *subreq = NULL;
 
-    /* prepare the data to pass to child */
-    child_req = talloc_zero(mem_ctx, struct sdap_child_req);
-    if (!child_req) goto fail;
-
-    child_req->ev = ev;
-    child_req->read_from_child_fd = -1;
-    child_req->write_to_child_fd = -1;
-    child_req->realm_str = realm_str;
-    child_req->princ_str = princ_str;
-    child_req->keytab_name = keytab_name;
-    child_req->timeout = timeout;
-    talloc_set_destructor((TALLOC_CTX *) child_req, sdap_child_req_destructor);
-
-    ret = create_ldap_send_buffer(child_req, &buf);
-    if (ret != EOK) {
-        DEBUG(1, ("create_ldap_send_buffer failed.\n"));
+    req = tevent_req_create(mem_ctx, &state, struct sdap_get_tgt_state);
+    if (!req) {
         return NULL;
     }
 
-    ret = fork_ldap_child(child_req);
-    if (ret != EOK) {
-        DEBUG(1, ("fork_ldap_child failed.\n"));
+    state->ev = ev;
+
+    state->child = talloc_zero(state, struct sdap_child);
+    if (!state->child) {
+        ret = ENOMEM;
         goto fail;
     }
 
-    ret = write(child_req->write_to_child_fd, buf->data, buf->size);
-    close(child_req->write_to_child_fd);
-    child_req->write_to_child_fd = -1;
-    if (ret == -1) {
-        ret = errno;
-        DEBUG(1, ("write failed [%d][%s].\n", ret, strerror(ret)));
-        return NULL;
-    }
+    state->child->read_from_child_fd = -1;
+    state->child->write_to_child_fd = -1;
+    talloc_set_destructor((TALLOC_CTX *)state->child, sdap_child_destructor);
 
-    req = tevent_req_create(mem_ctx, &state, struct sdap_krb5_get_tgt_state);
-    if (req == NULL) {
-        return NULL;
+    /* prepare the data to pass to child */
+    ret = create_tgt_req_send_buffer(state,
+                                     realm_str, princ_str, keytab_name,
+                                     &buf);
+    if (ret != EOK) {
+        DEBUG(1, ("create_tgt_req_send_buffer failed.\n"));
+        goto fail;
     }
 
-    state->lr = child_req;
+    ret = sdap_fork_child(state->child);
+    if (ret != EOK) {
+        DEBUG(1, ("sdap_fork_child failed.\n"));
+        goto fail;
+    }
 
-    child_req->req = req;
-    ret = activate_child_timeout_handler(child_req);
+    ret = set_tgt_child_timeout(req, ev, timeout);
     if (ret != EOK) {
         DEBUG(1, ("activate_child_timeout_handler failed.\n"));
-        return NULL;
+        goto fail;
     }
 
-    subreq = read_pipe_send(state, ev, child_req->read_from_child_fd);
-    if (tevent_req_nomem(subreq, req)) {
-        return tevent_req_post(req, ev);
+    subreq = write_pipe_send(state, ev, buf->data, buf->size,
+                             state->child->write_to_child_fd);
+    if (!subreq) {
+        ret = ENOMEM;
+        goto fail;
     }
-    tevent_req_set_callback(subreq, sdap_krb5_get_tgt_done, req);
+    tevent_req_set_callback(subreq, sdap_get_tgt_step, req);
 
     return req;
+
 fail:
-    return NULL;
+    tevent_req_error(req, ret);
+    tevent_req_post(req, ev);
+    return req;
+}
+
+static void sdap_get_tgt_step(struct tevent_req *subreq)
+{
+    struct tevent_req *req = tevent_req_callback_data(subreq,
+                                                      struct tevent_req);
+    struct sdap_get_tgt_state *state = tevent_req_data(req,
+                                                  struct sdap_get_tgt_state);
+    int ret;
+
+    ret = write_pipe_recv(subreq);
+    talloc_zfree(subreq);
+    if (ret != EOK) {
+        tevent_req_error(req, ret);
+        return;
+    }
+
+    sdap_close_fd(&state->child->write_to_child_fd);
+
+    subreq = read_pipe_send(state, state->ev,
+                            state->child->read_from_child_fd);
+    if (!subreq) {
+        tevent_req_error(req, ENOMEM);
+        return;
+    }
+    tevent_req_set_callback(subreq, sdap_get_tgt_done, req);
 }
 
-static void sdap_krb5_get_tgt_done(struct tevent_req *subreq)
+static void sdap_get_tgt_done(struct tevent_req *subreq)
 {
     struct tevent_req *req = tevent_req_callback_data(subreq,
                                                       struct tevent_req);
-    struct sdap_krb5_get_tgt_state *state = tevent_req_data(req,
-                                                       struct sdap_krb5_get_tgt_state);
+    struct sdap_get_tgt_state *state = tevent_req_data(req,
+                                                  struct sdap_get_tgt_state);
     int ret;
 
     ret = read_pipe_recv(subreq, state, &state->buf, &state->len);
     talloc_zfree(subreq);
-    talloc_zfree(state->lr->timeout_handler);
-    close(state->lr->read_from_child_fd);
-    state->lr->read_from_child_fd = -1;
     if (ret != EOK) {
         tevent_req_error(req, ret);
         return;
     }
 
+    sdap_close_fd(&state->child->read_from_child_fd);
+
     tevent_req_done(req);
-    return;
 }
 
-int sdap_krb5_get_tgt_recv(struct tevent_req *req,
+int sdap_get_tgt_recv(struct tevent_req *req,
                            TALLOC_CTX *mem_ctx,
                            int  *result,
                            char **ccname)
 {
-    struct sdap_krb5_get_tgt_state *state = tevent_req_data(req,
-                                                            struct sdap_krb5_get_tgt_state);
+    struct sdap_get_tgt_state *state = tevent_req_data(req,
+                                             struct sdap_get_tgt_state);
     char *ccn;
     int  res;
     int ret;
@@ -388,6 +391,49 @@ int sdap_krb5_get_tgt_recv(struct tevent_req *req,
     return EOK;
 }
 
+
+
+static void get_tgt_timeout_handler(struct tevent_context *ev,
+                                    struct tevent_timer *te,
+                                    struct timeval tv, void *pvt)
+{
+    struct tevent_req *req = talloc_get_type(pvt, struct tevent_req);
+    struct sdap_get_tgt_state *state = tevent_req_data(req,
+                                            struct sdap_get_tgt_state);
+    int ret;
+
+    DEBUG(9, ("timeout for tgt child [%d] reached.\n", state->child->pid));
+
+    ret = kill(state->child->pid, SIGKILL);
+    if (ret == -1) {
+        DEBUG(1, ("kill failed [%d][%s].\n", errno, strerror(errno)));
+    }
+
+    tevent_req_error(req, ETIMEDOUT);
+}
+
+static errno_t set_tgt_child_timeout(struct tevent_req *req,
+                                     struct tevent_context *ev,
+                                     int timeout)
+{
+    struct tevent_timer *te;
+    struct timeval tv;
+
+    DEBUG(6, ("Setting %d seconds timeout for tgt child\n", timeout));
+
+    tv = tevent_timeval_current_ofs(timeout, 0);
+
+    te = tevent_add_timer(ev, req, tv, get_tgt_timeout_handler, req);
+    if (te == NULL) {
+        DEBUG(1, ("tevent_add_timer failed.\n"));
+        return ENOMEM;
+    }
+
+    return EOK;
+}
+
+
+
 /* Setup child logging */
 int setup_child(struct sdap_id_ctx *ctx)
 {