Initial checkin of gRPC to third_party/

third_party/grpc/src/core/security/client_auth_filter.c

Index: third_party/grpc/src/core/security/client_auth_filter.c
diff --git a/third_party/grpc/src/core/security/client_auth_filter.c b/third_party/grpc/src/core/security/client_auth_filter.c
new file mode 100644
index 0000000000000000000000000000000000000000..332d4259d2843fee3f8cf013339beb83f1859c6f
--- /dev/null
+++ b/third_party/grpc/src/core/security/client_auth_filter.c
@@ -0,0 +1,336 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/security/auth_filters.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/channel/channel_stack.h"
+#include "src/core/security/credentials.h"
+#include "src/core/security/security_connector.h"
+#include "src/core/security/security_context.h"
+#include "src/core/support/string.h"
+#include "src/core/surface/call.h"
+#include "src/core/transport/static_metadata.h"
+
+#define MAX_CREDENTIALS_METADATA_COUNT 4
+
+/* We can have a per-call credentials. */
+typedef struct {
+  grpc_call_credentials *creds;
+  grpc_mdstr *host;
+  grpc_mdstr *method;
+  /* pollset bound to this call; if we need to make external
+     network requests, they should be done under this pollset
+     so that work can progress when this call wants work to
+     progress */
+  grpc_pollset *pollset;
+  grpc_transport_stream_op op;
+  uint8_t security_context_set;
+  grpc_linked_mdelem md_links[MAX_CREDENTIALS_METADATA_COUNT];
+  grpc_auth_metadata_context auth_md_context;
+} call_data;
+
+/* We can have a per-channel credentials. */
+typedef struct {
+  grpc_channel_security_connector *security_connector;
+  grpc_auth_context *auth_context;
+} channel_data;
+
+static void reset_auth_metadata_context(
+    grpc_auth_metadata_context *auth_md_context) {
+  if (auth_md_context->service_url != NULL) {
+    gpr_free((char *)auth_md_context->service_url);
+    auth_md_context->service_url = NULL;
+  }
+  if (auth_md_context->method_name != NULL) {
+    gpr_free((char *)auth_md_context->method_name);
+    auth_md_context->method_name = NULL;
+  }
+  GRPC_AUTH_CONTEXT_UNREF(
+      (grpc_auth_context *)auth_md_context->channel_auth_context,
+      "grpc_auth_metadata_context");
+  auth_md_context->channel_auth_context = NULL;
+}
+
+static void bubble_up_error(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                            grpc_status_code status, const char *error_msg) {
+  call_data *calld = elem->call_data;
+  gpr_log(GPR_ERROR, "Client side authentication failure: %s", error_msg);
+  grpc_transport_stream_op_add_cancellation(&calld->op, status);
+  grpc_call_next_op(exec_ctx, elem, &calld->op);
+}
+
+static void on_credentials_metadata(grpc_exec_ctx *exec_ctx, void *user_data,
+                                    grpc_credentials_md *md_elems,
+                                    size_t num_md,
+                                    grpc_credentials_status status) {
+  grpc_call_element *elem = (grpc_call_element *)user_data;
+  call_data *calld = elem->call_data;
+  grpc_transport_stream_op *op = &calld->op;
+  grpc_metadata_batch *mdb;
+  size_t i;
+  reset_auth_metadata_context(&calld->auth_md_context);
+  if (status != GRPC_CREDENTIALS_OK) {
+    bubble_up_error(exec_ctx, elem, GRPC_STATUS_UNAUTHENTICATED,
+                    "Credentials failed to get metadata.");
+    return;
+  }
+  GPR_ASSERT(num_md <= MAX_CREDENTIALS_METADATA_COUNT);
+  GPR_ASSERT(op->send_initial_metadata != NULL);
+  mdb = op->send_initial_metadata;
+  for (i = 0; i < num_md; i++) {
+    grpc_metadata_batch_add_tail(
+        mdb, &calld->md_links[i],
+        grpc_mdelem_from_slices(gpr_slice_ref(md_elems[i].key),
+                                gpr_slice_ref(md_elems[i].value)));
+  }
+  grpc_call_next_op(exec_ctx, elem, op);
+}
+
+void build_auth_metadata_context(grpc_security_connector *sc,
+                                 grpc_auth_context *auth_context,
+                                 call_data *calld) {
+  char *service = gpr_strdup(grpc_mdstr_as_c_string(calld->method));
+  char *last_slash = strrchr(service, '/');
+  char *method_name = NULL;
+  char *service_url = NULL;
+  reset_auth_metadata_context(&calld->auth_md_context);
+  if (last_slash == NULL) {
+    gpr_log(GPR_ERROR, "No '/' found in fully qualified method name");
+    service[0] = '\0';
+  } else if (last_slash == service) {
+    /* No service part in fully qualified method name: will just be "/". */
+    service[1] = '\0';
+  } else {
+    *last_slash = '\0';
+    method_name = gpr_strdup(last_slash + 1);
+  }
+  if (method_name == NULL) method_name = gpr_strdup("");
+  gpr_asprintf(&service_url, "%s://%s%s",
+               sc->url_scheme == NULL ? "" : sc->url_scheme,
+               grpc_mdstr_as_c_string(calld->host), service);
+  calld->auth_md_context.service_url = service_url;
+  calld->auth_md_context.method_name = method_name;
+  calld->auth_md_context.channel_auth_context =
+      GRPC_AUTH_CONTEXT_REF(auth_context, "grpc_auth_metadata_context");
+  gpr_free(service);
+}
+
+static void send_security_metadata(grpc_exec_ctx *exec_ctx,
+                                   grpc_call_element *elem,
+                                   grpc_transport_stream_op *op) {
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
+  grpc_client_security_context *ctx =
+      (grpc_client_security_context *)op->context[GRPC_CONTEXT_SECURITY].value;
+  grpc_call_credentials *channel_call_creds =
+      chand->security_connector->request_metadata_creds;
+  int call_creds_has_md = (ctx != NULL) && (ctx->creds != NULL);
+
+  if (channel_call_creds == NULL && !call_creds_has_md) {
+    /* Skip sending metadata altogether. */
+    grpc_call_next_op(exec_ctx, elem, op);
+    return;
+  }
+
+  if (channel_call_creds != NULL && call_creds_has_md) {
+    calld->creds = grpc_composite_call_credentials_create(channel_call_creds,
+                                                          ctx->creds, NULL);
+    if (calld->creds == NULL) {
+      bubble_up_error(exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT,
+                      "Incompatible credentials set on channel and call.");
+      return;
+    }
+  } else {
+    calld->creds = grpc_call_credentials_ref(
+        call_creds_has_md ? ctx->creds : channel_call_creds);
+  }
+
+  build_auth_metadata_context(&chand->security_connector->base,
+                              chand->auth_context, calld);
+  calld->op = *op; /* Copy op (originates from the caller's stack). */
+  GPR_ASSERT(calld->pollset);
+  grpc_call_credentials_get_request_metadata(
+      exec_ctx, calld->creds, calld->pollset, calld->auth_md_context,
+      on_credentials_metadata, elem);
+}
+
+static void on_host_checked(grpc_exec_ctx *exec_ctx, void *user_data,
+                            grpc_security_status status) {
+  grpc_call_element *elem = (grpc_call_element *)user_data;
+  call_data *calld = elem->call_data;
+
+  if (status == GRPC_SECURITY_OK) {
+    send_security_metadata(exec_ctx, elem, &calld->op);
+  } else {
+    char *error_msg;
+    gpr_asprintf(&error_msg, "Invalid host %s set in :authority metadata.",
+                 grpc_mdstr_as_c_string(calld->host));
+    bubble_up_error(exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT, error_msg);
+    gpr_free(error_msg);
+  }
+}
+
+/* Called either:
+     - in response to an API call (or similar) from above, to send something
+     - a network event (or similar) from below, to receive something
+   op contains type and call direction information, in addition to the data
+   that is being sent or received. */
+static void auth_start_transport_op(grpc_exec_ctx *exec_ctx,
+                                    grpc_call_element *elem,
+                                    grpc_transport_stream_op *op) {
+  /* grab pointers to our data from the call element */
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
+  grpc_linked_mdelem *l;
+  grpc_client_security_context *sec_ctx = NULL;
+
+  if (calld->security_context_set == 0 &&
+      op->cancel_with_status == GRPC_STATUS_OK) {
+    calld->security_context_set = 1;
+    GPR_ASSERT(op->context);
+    if (op->context[GRPC_CONTEXT_SECURITY].value == NULL) {
+      op->context[GRPC_CONTEXT_SECURITY].value =
+          grpc_client_security_context_create();
+      op->context[GRPC_CONTEXT_SECURITY].destroy =
+          grpc_client_security_context_destroy;
+    }
+    sec_ctx = op->context[GRPC_CONTEXT_SECURITY].value;
+    GRPC_AUTH_CONTEXT_UNREF(sec_ctx->auth_context, "client auth filter");
+    sec_ctx->auth_context =
+        GRPC_AUTH_CONTEXT_REF(chand->auth_context, "client_auth_filter");
+  }
+
+  if (op->send_initial_metadata != NULL) {
+    for (l = op->send_initial_metadata->list.head; l != NULL; l = l->next) {
+      grpc_mdelem *md = l->md;
+      /* Pointer comparison is OK for md_elems created from the same context.
+       */
+      if (md->key == GRPC_MDSTR_AUTHORITY) {
+        if (calld->host != NULL) GRPC_MDSTR_UNREF(calld->host);
+        calld->host = GRPC_MDSTR_REF(md->value);
+      } else if (md->key == GRPC_MDSTR_PATH) {
+        if (calld->method != NULL) GRPC_MDSTR_UNREF(calld->method);
+        calld->method = GRPC_MDSTR_REF(md->value);
+      }
+    }
+    if (calld->host != NULL) {
+      const char *call_host = grpc_mdstr_as_c_string(calld->host);
+      calld->op = *op; /* Copy op (originates from the caller's stack). */
+      grpc_channel_security_connector_check_call_host(
+          exec_ctx, chand->security_connector, call_host, chand->auth_context,
+          on_host_checked, elem);
+      return; /* early exit */
+    }
+  }
+
+  /* pass control down the stack */
+  grpc_call_next_op(exec_ctx, elem, op);
+}
+
+/* Constructor for call_data */
+static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                           grpc_call_element_args *args) {
+  call_data *calld = elem->call_data;
+  memset(calld, 0, sizeof(*calld));
+}
+
+static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                        grpc_pollset *pollset) {
+  call_data *calld = elem->call_data;
+  calld->pollset = pollset;
+}
+
+/* Destructor for call_data */
+static void destroy_call_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_call_element *elem) {
+  call_data *calld = elem->call_data;
+  grpc_call_credentials_unref(calld->creds);
+  if (calld->host != NULL) {
+    GRPC_MDSTR_UNREF(calld->host);
+  }
+  if (calld->method != NULL) {
+    GRPC_MDSTR_UNREF(calld->method);
+  }
+  reset_auth_metadata_context(&calld->auth_md_context);
+}
+
+/* Constructor for channel_data */
+static void init_channel_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_channel_element *elem,
+                              grpc_channel_element_args *args) {
+  grpc_security_connector *sc =
+      grpc_find_security_connector_in_args(args->channel_args);
+  grpc_auth_context *auth_context =
+      grpc_find_auth_context_in_args(args->channel_args);
+
+  /* grab pointers to our data from the channel element */
+  channel_data *chand = elem->channel_data;
+
+  /* The first and the last filters tend to be implemented differently to
+     handle the case that there's no 'next' filter to call on the up or down
+     path */
+  GPR_ASSERT(!args->is_last);
+  GPR_ASSERT(sc != NULL);
+  GPR_ASSERT(auth_context != NULL);
+
+  /* initialize members */
+  chand->security_connector =
+      (grpc_channel_security_connector *)GRPC_SECURITY_CONNECTOR_REF(
+          sc, "client_auth_filter");
+  chand->auth_context =
+      GRPC_AUTH_CONTEXT_REF(auth_context, "client_auth_filter");
+}
+
+/* Destructor for channel data */
+static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel_element *elem) {
+  /* grab pointers to our data from the channel element */
+  channel_data *chand = elem->channel_data;
+  grpc_channel_security_connector *sc = chand->security_connector;
+  if (sc != NULL) {
+    GRPC_SECURITY_CONNECTOR_UNREF(&sc->base, "client_auth_filter");
+  }
+  GRPC_AUTH_CONTEXT_UNREF(chand->auth_context, "client_auth_filter");
+}
+
+const grpc_channel_filter grpc_client_auth_filter = {
+    auth_start_transport_op, grpc_channel_next_op, sizeof(call_data),
+    init_call_elem, set_pollset, destroy_call_elem, sizeof(channel_data),
+    init_channel_elem, destroy_channel_elem, grpc_call_next_get_peer,
+    "client-auth"};