Added a ring buffer log target to store the last N log messages.

The log target can be used via log alarms and show alarms.
Why? This feature was proposed/requested at
http://openbsc.osmocom.org/trac/wiki/Tasks/ErrorLogTarget
All messages use the same amount of space, prioritizing simplicity.

1 files changed, 81 insertions, 4 deletions

diff --git a/src/vty/logging_vty.c b/src/vty/logging_vty.c
index d473f129..ace346a2 100644
--- a/src/vty/logging_vty.c
+++ b/src/vty/logging_vty.c
@@ -27,8 +27,8 @@
 #include <osmocom/core/talloc.h>
 #include <osmocom/core/logging.h>
 #include <osmocom/core/utils.h>
-
-//#include <openbsc/vty.h>
+#include <osmocom/core/strrb.h>
+#include <osmocom/core/loggingrb.h>
 
 #include <osmocom/vty/command.h>
 #include <osmocom/vty/buffer.h>
@@ -252,8 +252,8 @@ static void vty_print_logtarget(struct vty *vty, const struct log_info *info,
 #define SHOW_LOG_STR "Show current logging configuration\n"
 
 DEFUN(show_logging_vty,
-      show_logging_vty_cmd,
-      "show logging vty",
+	show_logging_vty_cmd,
+	"show logging vty",
 	SHOW_STR SHOW_LOG_STR
 	"Show current logging configuration for this vty\n")
 {
@@ -267,6 +267,33 @@ DEFUN(show_logging_vty,
 	return CMD_SUCCESS;
 }
 
+DEFUN(show_alarms,
+	show_alarms_cmd,
+	"show alarms",
+	SHOW_STR SHOW_LOG_STR
+	"Show the contents of the logging ringbuffer\n")
+{
+	int i, num_alarms;
+	struct osmo_strrb *rb;
+	struct log_target *tgt = log_target_find(LOG_TGT_TYPE_STRRB, NULL);
+	if (!tgt) {
+		vty_out(vty, "%% No alarms, run 'log alarms <2-32700>'%s",
+			VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	rb = tgt->tgt_rb.rb;
+	num_alarms = osmo_strrb_elements(rb);
+
+	vty_out(vty, "%% Showing %i alarms%s", num_alarms, VTY_NEWLINE);
+
+	for (i = 0; i < num_alarms; i++)
+		vty_out(vty, "%% %s%s", osmo_strrb_get_nth(rb, i),
+			VTY_NEWLINE);
+
+	return CMD_SUCCESS;
+}
+
 gDEFUN(cfg_description, cfg_description_cmd,
 	"description .TEXT",
 	"Save human-readable decription of the object\n"
@@ -510,6 +537,49 @@ DEFUN(cfg_no_log_file, cfg_no_log_file_cmd,
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_log_alarms, cfg_log_alarms_cmd,
+	"log alarms <2-32700>",
+	LOG_STR "Logging alarms to osmo_strrb\n"
+	"Maximum number of messages to log\n")
+{
+	struct log_target *tgt;
+	unsigned int rbsize = atoi(argv[0]);
+
+	tgt = log_target_find(LOG_TGT_TYPE_STRRB, NULL);
+	if (tgt)
+		log_target_destroy(tgt);
+
+	tgt = log_target_create_rb(rbsize);
+	if (!tgt) {
+		vty_out(vty, "%% Unable to create osmo_strrb (size %u)%s",
+			rbsize, VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	log_add_target(tgt);
+
+	vty->index = tgt;
+	vty->node = CFG_LOG_NODE;
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_no_log_alarms, cfg_no_log_alarms_cmd,
+	"no log alarms",
+	NO_STR LOG_STR "Logging alarms to osmo_strrb\n")
+{
+	struct log_target *tgt;
+
+	tgt = log_target_find(LOG_TGT_TYPE_STRRB, NULL);
+	if (!tgt) {
+		vty_out(vty, "%% No osmo_strrb target found%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	log_target_destroy(tgt);
+
+	return CMD_SUCCESS;
+}
+
 static int config_write_log_single(struct vty *vty, struct log_target *tgt)
 {
 	int i;
@@ -533,6 +603,10 @@ static int config_write_log_single(struct vty *vty, struct log_target *tgt)
 	case LOG_TGT_TYPE_FILE:
 		vty_out(vty, "log file %s%s", tgt->tgt_file.fname, VTY_NEWLINE);
 		break;
+	case LOG_TGT_TYPE_STRRB:
+		vty_out(vty, "log alarms %zu%s",
+			log_target_rb_avail_size(tgt), VTY_NEWLINE);
+		break;
 	}
 
 	vty_out(vty, "  logging filter all %u%s",
@@ -590,6 +664,7 @@ void logging_vty_add_cmds(const struct log_info *cat)
 	logging_level_cmd.doc = log_vty_command_description(cat);
 	install_element_ve(&logging_level_cmd);
 	install_element_ve(&show_logging_vty_cmd);
+	install_element_ve(&show_alarms_cmd);
 
 	install_node(&cfg_log_node, config_write_log);
 	install_default(CFG_LOG_NODE);
@@ -603,6 +678,8 @@ void logging_vty_add_cmds(const struct log_info *cat)
 	install_element(CONFIG_NODE, &cfg_no_log_stderr_cmd);
 	install_element(CONFIG_NODE, &cfg_log_file_cmd);
 	install_element(CONFIG_NODE, &cfg_no_log_file_cmd);
+	install_element(CONFIG_NODE, &cfg_log_alarms_cmd);
+	install_element(CONFIG_NODE, &cfg_no_log_alarms_cmd);
 #ifdef HAVE_SYSLOG_H
 	install_element(CONFIG_NODE, &cfg_log_syslog_cmd);
 	install_element(CONFIG_NODE, &cfg_log_syslog_local_cmd);