v2 rpc: add log_file field to opts, add defaults toi log.h and use them where needed

[xemul: Simplified !log_file case and renumbered .proto fields]
Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-service.c

@@ -111,7 +111,10 @@ static int setup_dump_from_req(int sk, CriuDumpReq *req)
 	log_closedir();
 
 	/* initiate log file in imgs dir */
-	opts.output = "./dump.log";
+	if (req->log_file)
+		opts.output = req->log_file;
+	else
+		opts.output = DEFAULT_DUMP_LOG_FILENAME;
 
 	log_set_loglevel(req->log_level);
 	if (log_init(opts.output) == -1) {

include/log.h

@@ -59,4 +59,7 @@ extern int write_pidfile(char *pfname, int pid);
 #define pr_perror(fmt, ...)							\
 	pr_err(fmt ": %m\n", ##__VA_ARGS__)
 
+#define DEFAULT_DUMP_LOG_FILENAME "dump.log"
+#define DEFAULT_RESTORE_LOG_FILENAME "restore.log"
+
 #endif /* __CR_LOG_H__ */

protobuf/rpc.proto

@@ -9,6 +9,7 @@ message criu_dump_req {
 	optional bool shell_job		= 7;
 	optional bool file_locks	= 8;
 	optional int32 log_level	= 9 [default = 2];
+	optional string log_file	= 10;
 }
 
 message criu_dump_resp {