[SERVER] More work towards automatic server discovery and querying

1 files changed, 64 insertions, 4 deletions

diff --git a/src/server/helper.h b/src/server/helper.h
index e787c42..fdcc3b5 100644
--- a/src/server/helper.h
+++ b/src/server/helper.h
@@ -4,6 +4,8 @@
 #include "server.h"
 #include <netinet/in.h>
 #include <string.h>
+#include <errno.h>
+#include <unistd.h>
 
 char parse_address(char *string, dnbd3_host_t *host);
 char host_to_string(const dnbd3_host_t *host, char *target, size_t targetlen);
@@ -11,11 +13,69 @@ char is_valid_namespace(char *namespace);
 char is_valid_imagename(char *namespace);
 void strtolower(char *string);
 
-static inline int is_same_server(const dnbd3_trusted_server_t *const a, const dnbd3_trusted_server_t *const b)
+static inline int is_same_server(const dnbd3_host_t *const a, const dnbd3_host_t *const b)
 {
-	return (a->host.type == b->host.type)
-	       && (a->host.port == b->host.port)
-	       && (0 == memcmp(a->host.addr, b->host.addr, (a->host.type == AF_INET ? 4 : 16)));
+	return (a->type == b->type)
+	       && (a->port == b->port)
+	       && (0 == memcmp(a->addr, b->addr, (a->type == AF_INET ? 4 : 16)));
+}
+
+/**
+ * Send message to client, return !=0 on success, 0 on failure
+ */
+static inline int send_data(int client_sock, void *data_in, int len)
+{
+	if (len <= 0) // Nothing to send
+		return 1;
+	char *data = data_in; // Needed for pointer arithmetic
+	int ret, i;
+	for (i = 0; i < 3; ++i) // Retry at most 3 times, each try takes at most 0.5 seconds (socket timeout)
+	{
+		ret = send(client_sock, data, len, 0);
+		if (ret == 0) // Connection closed
+			return 0;
+		if (ret < 0)
+		{
+			if (errno != EAGAIN) // Some unexpected error
+				return 0;
+			usleep(1000); // 1ms
+			continue;
+		}
+		len -= ret;
+		if (len <= 0) // Sent everything
+			return 1;
+		data += ret; // move target buffer pointer
+	}
+	return 0;
+}
+
+/**
+ * Receive data from client, return !=0 on success, 0 on failure
+ */
+static inline int recv_data(int client_sock, void *buffer_out, int len)
+{
+	if (len <= 0) // Nothing to receive
+		return 1;
+	char *data = buffer_out; // Needed for pointer arithmetic
+	int ret, i;
+	for (i = 0; i < 3; ++i) // Retry at most 3 times, each try takes at most 0.5 seconds (socket timeout)
+	{
+		ret = recv(client_sock, data, len, MSG_WAITALL);
+		if (ret == 0) // Connection closed
+			return 0;
+		if (ret < 0)
+		{
+			if (errno != EAGAIN) // Some unexpected error
+				return 0;
+			usleep(1000); // 1ms
+			continue;
+		}
+		len -= ret;
+		if (len <= 0) // Received everything
+			return 1;
+		data += ret; // move target buffer pointer
+	}
+	return 0;
 }
 
 // one byte in the map covers 8 4kib blocks, so 32kib per byte