Add support for service configs to c-ares resolver.

5 files changed, 136 insertions, 0 deletions

diff --git a/src/core/lib/iomgr/gethostname.h b/src/core/lib/iomgr/gethostname.h
new file mode 100644
index 0000000000..9c6b9d8d42
--- /dev/null
+++ b/src/core/lib/iomgr/gethostname.h
@@ -0,0 +1,26 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_GETHOSTNAME_H
+#define GRPC_CORE_LIB_IOMGR_GETHOSTNAME_H
+
+// Returns the hostname of the local machine.
+// Caller takes ownership of result.
+char *grpc_gethostname();
+
+#endif /* GRPC_CORE_LIB_IOMGR_GETHOSTNAME_H */
diff --git a/src/core/lib/iomgr/gethostname_fallback.c b/src/core/lib/iomgr/gethostname_fallback.c
new file mode 100644
index 0000000000..6229461568
--- /dev/null
+++ b/src/core/lib/iomgr/gethostname_fallback.c
@@ -0,0 +1,27 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_GETHOSTNAME_FALLBACK
+
+#include <stddef.h>
+
+char *grpc_gethostname() { return NULL; }
+
+#endif  // GRPC_GETHOSTNAME_FALLBACK
diff --git a/src/core/lib/iomgr/gethostname_host_name_max.c b/src/core/lib/iomgr/gethostname_host_name_max.c
new file mode 100644
index 0000000000..4d0511412e
--- /dev/null
+++ b/src/core/lib/iomgr/gethostname_host_name_max.c
@@ -0,0 +1,37 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_POSIX_HOST_NAME_MAX
+
+#include <limits.h>
+#include <unistd.h>
+
+#include <grpc/support/alloc.h>
+
+char *grpc_gethostname() {
+  char *hostname = (char *)gpr_malloc(HOST_NAME_MAX);
+  if (gethostname(hostname, HOST_NAME_MAX) != 0) {
+    gpr_free(hostname);
+    return NULL;
+  }
+  return hostname;
+}
+
+#endif  // GRPC_POSIX_HOST_NAME_MAX
diff --git a/src/core/lib/iomgr/gethostname_sysconf.c b/src/core/lib/iomgr/gethostname_sysconf.c
new file mode 100644
index 0000000000..51bac5d69d
--- /dev/null
+++ b/src/core/lib/iomgr/gethostname_sysconf.c
@@ -0,0 +1,37 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_POSIX_SYSCONF
+
+#include <unistd.h>
+
+#include <grpc/support/alloc.h>
+
+char *grpc_gethostname() {
+  size_t host_name_max = (size_t)sysconf(_SC_HOST_NAME_MAX);
+  char *hostname = (char *)gpr_malloc(host_name_max);
+  if (gethostname(hostname, host_name_max) != 0) {
+    gpr_free(hostname);
+    return NULL;
+  }
+  return hostname;
+}
+
+#endif  // GRPC_POSIX_SYSCONF
diff --git a/src/core/lib/iomgr/port.h b/src/core/lib/iomgr/port.h
index c12058f890..42033d0ba4 100644
--- a/src/core/lib/iomgr/port.h
+++ b/src/core/lib/iomgr/port.h
@@ -59,6 +59,7 @@
 #define GRPC_HAVE_MSG_NOSIGNAL 1
 #define GRPC_HAVE_UNIX_SOCKET 1
 #define GRPC_LINUX_MULTIPOLL_WITH_EPOLL 1
+#define GRPC_POSIX_HOST_NAME_MAX 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
 #define GRPC_POSIX_WAKEUP_FD 1
@@ -93,6 +94,7 @@
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
 #define GRPC_POSIX_SOCKETUTILS 1
+#define GRPC_POSIX_SYSCONF 1
 #define GRPC_POSIX_WAKEUP_FD 1
 #define GRPC_TIMER_USE_GENERIC 1
 #elif defined(GPR_FREEBSD)
@@ -125,4 +127,11 @@
 #error Must define exactly one of GRPC_POSIX_SOCKET, GRPC_WINSOCK_SOCKET, GPR_CUSTOM_SOCKET
 #endif
 
+#if defined(GRPC_POSIX_HOST_NAME_MAX) && defined(GRPC_POSIX_SYSCONF)
+#error "Cannot define both GRPC_POSIX_HOST_NAME_MAX and GRPC_POSIX_SYSCONF"
+#endif
+#if !defined(GRPC_POSIX_HOST_NAME_MAX) && !defined(GRPC_POSIX_SYSCONF)
+#define GRPC_GETHOSTNAME_FALLBACK 1
+#endif
+
 #endif /* GRPC_CORE_LIB_IOMGR_PORT_H */