T: add a 'multi' tracer

This tracer allows the connection of several tracers to one tracee.

To use the multi tracer:
- run the tracee as usual, eg. ./lte-softmodem -O xxxx.conf --T_stdout 0
- run the multi tracer: ./multi -d ../T_messages.txt
- connect other tracers to the multi tracer:
   - ./enb -d ../T_messages.txt -p 2022
   - ./textlog -d ../T_messages.txt -p 2022
   - etc.

By default the multi tracer connects to the tracee to the port 2021,
as for any other tracer.

Then it accepts connections from other tracers on the port 2022.

This can be changed with parameters on the command line.

The tracee and the other tracers can be stopped/started at any time.

common/utils/T/.gitignore

@@ -15,4 +15,5 @@ tracer/to_vcd
 tracer/extract_input_subframe
 tracer/extract_output_subframe
 tracer/extract
+tracer/multi
 tracee/tracee

common/utils/T/tracer/Makefile

@@ -7,7 +7,7 @@ LIBS=-lm
 XLIBS=-lX11 -lpng -lXft
 
 all: record replay extract_config textlog enb ue vcd macpdu2wireshark \
-     extract_input_subframe extract_output_subframe to_vcd extract
+     extract_input_subframe extract_output_subframe to_vcd extract multi
 
 record: utils.o record.o database.o config.o
 	$(CC) $(CFLAGS) -o record $^ $(LIBS)
@@ -57,6 +57,9 @@ macpdu2wireshark: macpdu2wireshark.o database.o utils.o handler.o event.o \
                   config.o
 	$(CC) $(CFLAGS) -o $@ $^ $(LIBS)
 
+multi: multi.o utils.o database.o config.o
+	$(CC) $(CFLAGS) -o multi $^ $(LIBS)
+
 .PHONY: all gui/gui.a view/view.a logger/logger.a filter/filter.a
 
 gui/gui.a:
@@ -77,7 +80,7 @@ filter/filter.a:
 clean:
 	rm -f *.o core tracer_remote textlog enb ue vcd record replay
 	rm -f extract_config macpdu2wireshark extract_input_subframe
-	rm -f extract_output_subframe to_vcd extract
+	rm -f extract_output_subframe to_vcd extract multi
 	cd gui && make clean
 	cd view && make clean
 	cd logger && make clean

common/utils/T/tracer/config.c

@@ -60,3 +60,9 @@ void verify_config(void)
     abort();
   }
 }
+
+void get_local_config(char **txt, int *len)
+{
+  *txt = local;
+  *len = local_size;
+}

common/utils/T/tracer/config.h

@@ -5,5 +5,6 @@ void clear_remote_config(void);
 void append_received_config_chunk(char *buf, int length);
 void load_config_file(char *filename);
 void verify_config(void);
+void get_local_config(char **txt, int *len);
 
 #endif /* _CONFIG_H_ */

common/utils/T/tracer/utils.c

@@ -79,6 +79,36 @@ list *list_append(list *l, void *data)
 /* socket                                                                   */
 /****************************************************************************/
 
+int create_listen_socket(char *addr, int port)
+{
+  struct sockaddr_in a;
+  int s;
+  int v;
+
+  s = socket(AF_INET, SOCK_STREAM, 0);
+  if (s == -1) { perror("socket"); exit(1); }
+  v = 1;
+  if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(int)))
+    { perror("setsockopt"); exit(1); }
+
+  a.sin_family = AF_INET;
+  a.sin_port = htons(port);
+  a.sin_addr.s_addr = inet_addr(addr);
+
+  if (bind(s, (struct sockaddr *)&a, sizeof(a))) { perror("bind"); exit(1); }
+  if (listen(s, 5)) { perror("listen"); exit(1); }
+
+  return s;
+}
+
+int socket_accept(int s)
+{
+  struct sockaddr_in a;
+  socklen_t alen;
+  alen = sizeof(a);
+  return accept(s, (struct sockaddr *)&a, &alen);
+}
+
 int socket_send(int socket, void *buffer, int size)
 {
   char *x = buffer;
@@ -94,26 +124,13 @@ int socket_send(int socket, void *buffer, int size)
 
 int get_connection(char *addr, int port)
 {
-  struct sockaddr_in a;
-  socklen_t alen;
   int s, t;
 
   printf("waiting for connection on %s:%d\n", addr, port);
 
-  s = socket(AF_INET, SOCK_STREAM, 0);
-  if (s == -1) { perror("socket"); exit(1); }
-  t = 1;
-  if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &t, sizeof(int)))
-    { perror("setsockopt"); exit(1); }
-
-  a.sin_family = AF_INET;
-  a.sin_port = htons(port);
-  a.sin_addr.s_addr = inet_addr(addr);
+  s = create_listen_socket(addr, port);
 
-  if (bind(s, (struct sockaddr *)&a, sizeof(a))) { perror("bind"); exit(1); }
-  if (listen(s, 5)) { perror("bind"); exit(1); }
-  alen = sizeof(a);
-  t = accept(s, (struct sockaddr *)&a, &alen);
+  t = socket_accept(s);
   if (t == -1) { perror("accept"); exit(1); }
   close(s);
 
@@ -137,14 +154,11 @@ int fullread(int fd, void *_buf, int count)
   return ret;
 }
 
-int connect_to(char *addr, int port)
+int try_connect_to(char *addr, int port)
 {
   int s;
   struct sockaddr_in a;
 
-  printf("connecting to %s:%d\n", addr, port);
-
-again:
   s = socket(AF_INET, SOCK_STREAM, 0);
   if (s == -1) { perror("socket"); exit(1); }
 
@@ -155,6 +169,21 @@ again:
   if (connect(s, (struct sockaddr *)&a, sizeof(a)) == -1) {
     perror("connect");
     close(s);
+    return -1;
+  }
+
+  return s;
+}
+
+int connect_to(char *addr, int port)
+{
+  int s;
+
+  printf("connecting to %s:%d\n", addr, port);
+
+again:
+  s = try_connect_to(addr, port);
+  if (s == -1) {
     printf("trying again in 1s\n");
     sleep(1);
     goto again;

common/utils/T/tracer/utils.h

@@ -24,11 +24,14 @@ list *list_append(list *l, void *data);
 #define DEFAULT_REMOTE_IP "127.0.0.1"
 #define DEFAULT_REMOTE_PORT 2021
 
+int create_listen_socket(char *addr, int port);
+int socket_accept(int s);
 /* socket_send: return 0 if okay, -1 on error */
 int socket_send(int socket, void *buffer, int size);
 int get_connection(char *addr, int port);
 /* fullread: return length read if okay (that is: 'count'), -1 on error */
 int fullread(int fd, void *_buf, int count);
+int try_connect_to(char *addr, int port);
 int connect_to(char *addr, int port);
 
 /****************************************************************************/