gdb_server: Improve logging of GDB-remote packets

- Print also the target name, not just the packet contents.
  This is important when there are more GDB servers (more
  debug-able targets) active in one OpenOCD session.

- Log also the received Ctrl-C requests coming from GDB
  (one byte 0x3), ACKs ("+") and NACKs ("-").

- Do not print zero-length incoming packets (this occurred
  when Ctrl-C packets were received).

- Removed a stray apostrophe "'" that got printed
  in gdb_log_outgoing_packet()

Signed-off-by: Jan Matyas <matyas@codasip.com>
Change-Id: If68fe0a8aa635165d0bbe6fa0e48a4645a02da67
Reviewed-on: https://review.openocd.org/c/openocd/+/6879
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index f5736196eddfb4717d389688d631c1e76f31bceb..82c8ce92b31faf395ee6f933ba147ee8ad1582ac 100644 (file)
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -371,11 +371,13 @@ static int gdb_write(struct connection *connection, void *data, int len)
        return ERROR_SERVER_REMOTE_CLOSED;
 }
 
-static void gdb_log_incoming_packet(char *packet)
+static void gdb_log_incoming_packet(struct connection *connection, char *packet)
 {
        if (!LOG_LEVEL_IS(LOG_LVL_DEBUG))
                return;
 
+       struct target *target = get_target_from_connection(connection);
+
        /* Avoid dumping non-printable characters to the terminal */
        const unsigned packet_len = strlen(packet);
        const char *nonprint = find_nonprint_char(packet, packet_len);
@@ -389,25 +391,31 @@ static void gdb_log_incoming_packet(char *packet)
                if (packet_prefix_printable) {
                        const unsigned int prefix_len = colon - packet + 1;  /* + 1 to include the ':' */
                        const unsigned int payload_len = packet_len - prefix_len;
-                       LOG_DEBUG("received packet: %.*s<binary-data-%u-bytes>", prefix_len, packet, payload_len);
+                       LOG_TARGET_DEBUG(target, "received packet: %.*s<binary-data-%u-bytes>", prefix_len,
+                               packet, payload_len);
                } else {
-                       LOG_DEBUG("received packet: <binary-data-%u-bytes>", packet_len);
+                       LOG_TARGET_DEBUG(target, "received packet: <binary-data-%u-bytes>", packet_len);
                }
        } else {
                /* All chars printable, dump the packet as is */
-               LOG_DEBUG("received packet: %s", packet);
+               LOG_TARGET_DEBUG(target, "received packet: %s", packet);
        }
 }
 
-static void gdb_log_outgoing_packet(char *packet_buf, unsigned int packet_len, unsigned char checksum)
+static void gdb_log_outgoing_packet(struct connection *connection, char *packet_buf,
+       unsigned int packet_len, unsigned char checksum)
 {
        if (!LOG_LEVEL_IS(LOG_LVL_DEBUG))
                return;
 
+       struct target *target = get_target_from_connection(connection);
+
        if (find_nonprint_char(packet_buf, packet_len))
-               LOG_DEBUG("sending packet: $<binary-data-%u-bytes>#%2.2x", packet_len, checksum);
+               LOG_TARGET_DEBUG(target, "sending packet: $<binary-data-%u-bytes>#%2.2x",
+                       packet_len, checksum);
        else
-               LOG_DEBUG("sending packet: $%.*s#%2.2x'", packet_len, packet_buf, checksum);
+               LOG_TARGET_DEBUG(target, "sending packet: $%.*s#%2.2x", packet_len, packet_buf,
+                       checksum);
 }
 
 static int gdb_put_packet_inner(struct connection *connection,
@@ -450,7 +458,7 @@ static int gdb_put_packet_inner(struct connection *connection,
 #endif
 
        while (1) {
-               gdb_log_outgoing_packet(buffer, len, my_checksum);
+               gdb_log_outgoing_packet(connection, buffer, len, my_checksum);
 
                char local_buffer[1024];
                local_buffer[0] = '$';
@@ -483,22 +491,27 @@ static int gdb_put_packet_inner(struct connection *connection,
                if (retval != ERROR_OK)
                        return retval;
 
-               if (reply == '+')
+               if (reply == '+') {
+                       gdb_log_incoming_packet(connection, "+");
                        break;
-               else if (reply == '-') {
+               } else if (reply == '-') {
                        /* Stop sending output packets for now */
                        gdb_con->output_flag = GDB_OUTPUT_NO;
+                       gdb_log_incoming_packet(connection, "-");
                        LOG_WARNING("negative reply, retrying");
                } else if (reply == 0x3) {
                        gdb_con->ctrl_c = true;
+                       gdb_log_incoming_packet(connection, "<Ctrl-C>");
                        retval = gdb_get_char(connection, &reply);
                        if (retval != ERROR_OK)
                                return retval;
-                       if (reply == '+')
+                       if (reply == '+') {
+                               gdb_log_incoming_packet(connection, "+");
                                break;
-                       else if (reply == '-') {
+                       } else if (reply == '-') {
                                /* Stop sending output packets for now */
                                gdb_con->output_flag = GDB_OUTPUT_NO;
+                               gdb_log_incoming_packet(connection, "-");
                                LOG_WARNING("negative reply, retrying");
                        } else if (reply == '$') {
                                LOG_ERROR("GDB missing ack(1) - assumed good");
@@ -675,6 +688,7 @@ static int gdb_get_packet_inner(struct connection *connection,
                                case '$':
                                        break;
                                case '+':
+                                       gdb_log_incoming_packet(connection, "+");
                                        /* According to the GDB documentation
                                         * (https://sourceware.org/gdb/onlinedocs/gdb/Packet-Acknowledgment.html):
                                         * "gdb sends a final `+` acknowledgment of the stub's `OK`
@@ -692,9 +706,11 @@ static int gdb_get_packet_inner(struct connection *connection,
                                        }
                                        break;
                                case '-':
+                                       gdb_log_incoming_packet(connection, "-");
                                        LOG_WARNING("negative acknowledgment, but no packet pending");
                                        break;
                                case 0x3:
+                                       gdb_log_incoming_packet(connection, "<Ctrl-C>");
                                        gdb_con->ctrl_c = true;
                                        *len = 0;
                                        return ERROR_OK;
@@ -3452,9 +3468,10 @@ static int gdb_input_inner(struct connection *connection)
                /* terminate with zero */
                gdb_packet_buffer[packet_size] = '\0';
 
-               gdb_log_incoming_packet(gdb_packet_buffer);
-
                if (packet_size > 0) {
+
+                       gdb_log_incoming_packet(connection, gdb_packet_buffer);
+
                        retval = ERROR_OK;
                        switch (packet[0]) {
                                case 'T':       /* Is thread alive? */