Initial checkin of gRPC to third_party/

third_party/grpc/src/objective-c/GRPCClient/private/GRPCChannel.m

+/*
+ *
+ * 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.
+ *
+ */
+
+#import "GRPCChannel.h"
+
+#include <grpc/grpc_security.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+/**
+ * Returns @c grpc_channel_credentials from the specified @c path. If the file at the path could not
+ * be read then NULL is returned. If NULL is returned, @c errorPtr may not be NULL if there are
+ * details available describing what went wrong.
+ */
+static grpc_channel_credentials *CertificatesAtPath(NSString *path, NSError **errorPtr) {
+  // Files in PEM format can have non-ASCII characters in their comments (e.g. for the name of the
+  // issuer). Load them as UTF8 and produce an ASCII equivalent.
+  NSString *contentInUTF8 = [NSString stringWithContentsOfFile:path
+                                                      encoding:NSUTF8StringEncoding
+                                                         error:errorPtr];
+  NSData *contentInASCII = [contentInUTF8 dataUsingEncoding:NSASCIIStringEncoding
+                                       allowLossyConversion:YES];
+  if (!contentInASCII.bytes) {
+    // Passing NULL to grpc_ssl_credentials_create produces behavior we don't want, so return.
+    return NULL;
+  }
+  return grpc_ssl_credentials_create(contentInASCII.bytes, NULL, NULL);
+}
+
+void freeChannelArgs(grpc_channel_args *channel_args) {
+  for (size_t i = 0; i < channel_args->num_args; ++i) {
+    grpc_arg *arg = &channel_args->args[i];
+    gpr_free(arg->key);
+    if (arg->type == GRPC_ARG_STRING) {
+      gpr_free(arg->value.string);
+    }
+  }
+  gpr_free(channel_args);
+}
+
+/**
+ * Allocates a @c grpc_channel_args and populates it with the options specified in the
+ * @c dictionary. Keys must be @c NSString. If the value responds to @c @selector(UTF8String) then
+ * it will be mapped to @c GRPC_ARG_STRING. If not, it will be mapped to @c GRPC_ARG_INTEGER if the
+ * value responds to @c @selector(intValue). Otherwise, an exception will be raised. The caller of
+ * this function is responsible for calling @c freeChannelArgs on a non-NULL returned value.
+ */
+grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
+  if (!dictionary) {
+    return NULL;
+  }
+
+  NSArray *keys = [dictionary allKeys];
+  NSUInteger argCount = [keys count];
+
+  grpc_channel_args *channelArgs = gpr_malloc(sizeof(grpc_channel_args));
+  channelArgs->num_args = argCount;
+  channelArgs->args = gpr_malloc(argCount * sizeof(grpc_arg));
+
+  // TODO(kriswuollett) Check that keys adhere to GRPC core library requirements
+
+  for (NSUInteger i = 0; i < argCount; ++i) {
+    grpc_arg *arg = &channelArgs->args[i];
+    arg->key = gpr_strdup([keys[i] UTF8String]);
+
+    id value = dictionary[keys[i]];
+    if ([value respondsToSelector:@selector(UTF8String)]) {
+      arg->type = GRPC_ARG_STRING;
+      arg->value.string = gpr_strdup([value UTF8String]);
+    } else if ([value respondsToSelector:@selector(intValue)]) {
+      arg->type = GRPC_ARG_INTEGER;
+      arg->value.integer = [value intValue];
+    } else {
+      [NSException raise:NSInvalidArgumentException
+                  format:@"Invalid value type: %@", [value class]];
+    }
+  }
+
+  return channelArgs;
+}
+
+@implementation GRPCChannel {
+  // Retain arguments to channel_create because they may not be used on the thread that invoked
+  // the channel_create function.
+  NSString *_host;
+  grpc_channel_args *_channelArgs;
+}
+
+
+- (instancetype)initWithHost:(NSString *)host
+                      secure:(BOOL)secure
+                 credentials:(struct grpc_channel_credentials *)credentials
+                 channelArgs:(NSDictionary *)channelArgs {
+  if (!host) {
+    [NSException raise:NSInvalidArgumentException format:@"host argument missing"];
+  }
+
+  if (secure && !credentials) {
+    return nil;
+  }
+
+  if (self = [super init]) {
+    _channelArgs = buildChannelArgs(channelArgs);
+    _host = [host copy];
+    if (secure) {
+      _unmanagedChannel = grpc_secure_channel_create(credentials, _host.UTF8String, _channelArgs,
+                                                     NULL);
+    } else {
+      _unmanagedChannel = grpc_insecure_channel_create(_host.UTF8String, _channelArgs, NULL);
+    }
+  }
+
+  return self;
+}
+
+- (void)dealloc {
+  // TODO(jcanizales): Be sure to add a test with a server that closes the connection prematurely,
+  // as in the past that made this call to crash.
+  grpc_channel_destroy(_unmanagedChannel);
+  freeChannelArgs(_channelArgs);
+}
+
++ (GRPCChannel *)secureChannelWithHost:(NSString *)host {
+  return [[GRPCChannel alloc] initWithHost:host secure:YES credentials:NULL channelArgs:NULL];
+}
+
++ (GRPCChannel *)secureChannelWithHost:(NSString *)host
+                    pathToCertificates:(NSString *)path
+                           channelArgs:(NSDictionary *)channelArgs {
+  // Load default SSL certificates once.
+  static grpc_channel_credentials *kDefaultCertificates;
+  static dispatch_once_t loading;
+  dispatch_once(&loading, ^{
+    NSString *defaultPath = @"gRPCCertificates.bundle/roots"; // .pem
+    // Do not use NSBundle.mainBundle, as it's nil for tests of library projects.
+    NSBundle *bundle = [NSBundle bundleForClass:self.class];
+    NSString *path = [bundle pathForResource:defaultPath ofType:@"pem"];
+    NSError *error;
+    kDefaultCertificates = CertificatesAtPath(path, &error);
+    NSAssert(kDefaultCertificates, @"Could not read %@/%@.pem. This file, with the root "
+             "certificates, is needed to establish secure (TLS) connections. Because the file is "
+             "distributed with the gRPC library, this error is usually a sign that the library "
+             "wasn't configured correctly for your project. Error: %@",
+             bundle.bundlePath, defaultPath, error);
+  });
+
+  //TODO(jcanizales): Add NSError** parameter to the initializer.
+  grpc_channel_credentials *certificates = path
+      ? CertificatesAtPath(path, NULL)
+      : kDefaultCertificates;
+
+  return [[GRPCChannel alloc] initWithHost:host
+                                    secure:YES
+                               credentials:certificates
+                               channelArgs:channelArgs];
+}
+
+
++ (GRPCChannel *)secureChannelWithHost:(NSString *)host
+                           credentials:(struct grpc_channel_credentials *)credentials
+                           channelArgs:(NSDictionary *)channelArgs {
+  return [[GRPCChannel alloc] initWithHost:host
+                                    secure:YES
+                               credentials:credentials
+                               channelArgs:channelArgs];
+
+}
+
++ (GRPCChannel *)insecureChannelWithHost:(NSString *)host
+                             channelArgs:(NSDictionary *)channelArgs {
+  return [[GRPCChannel alloc] initWithHost:host
+                                    secure:NO
+                               credentials:NULL
+                               channelArgs:channelArgs];
+}
+
+@end