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.
diff --git a/src/Makefile.am b/src/Makefile.am
index b425ea1..081be96 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -11,8 +11,8 @@
write_queue.c utils.c socket.c \
logging.c logging_syslog.c rate_ctr.c \
gsmtap_util.c crc16.c panic.c backtrace.c \
- conv.c application.c rbtree.c \
- crc8gen.c crc16gen.c crc32gen.c crc64gen.c
+ conv.c application.c rbtree.c strrb.c \
+ loggingrb.c crc8gen.c crc16gen.c crc32gen.c crc64gen.c
BUILT_SOURCES = crc8gen.c crc16gen.c crc32gen.c crc64gen.c
diff --git a/src/loggingrb.c b/src/loggingrb.c
new file mode 100644
index 0000000..b206fde
--- /dev/null
+++ b/src/loggingrb.c
@@ -0,0 +1,98 @@
+/* Ringbuffer-backed logging support code */
+
+/* (C) 2012-2013 by Katerina Barone-Adesi
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+/*! \addtogroup logging
+ * @{
+ */
+
+/*! \file loggingrb.c */
+
+#include <osmocom/core/strrb.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/loggingrb.h>
+
+static void _rb_output(struct log_target *target,
+ unsigned int level, const char *log)
+{
+ osmo_strrb_add(target->tgt_rb.rb, log);
+}
+
+/*! \brief Return the number of log strings in the osmo_strrb-backed target.
+ * \param[in] target The target to search.
+ *
+ * \return The number of log strings in the osmo_strrb-backed target.
+ */
+size_t log_target_rb_used_size(struct log_target const *target)
+{
+ return osmo_strrb_elements(target->tgt_rb.rb);
+}
+
+/*! \brief Return the capacity of the osmo_strrb-backed target.
+ * \param[in] target The target to search.
+ *
+ * Note that this is the capacity (aka max number of messages).
+ * It is not the number of unused message slots.
+ * \return The number of log strings in the osmo_strrb-backed target.
+ */
+size_t log_target_rb_avail_size(struct log_target const *target)
+{
+ struct osmo_strrb *rb = target->tgt_rb.rb;
+ return rb->size - 1;
+}
+
+/*! \brief Return the nth log entry in a target.
+ * \param[in] target The target to search.
+ * \param[in] logindex The index of the log entry/error message.
+ *
+ * \return A pointer to the nth message, or NULL if logindex is invalid.
+ */
+const char *log_target_rb_get(struct log_target const *target, size_t logindex)
+{
+ return osmo_strrb_get_nth(target->tgt_rb.rb, logindex);
+}
+
+/*! \brief Create a new logging target for ringbuffer-backed logging.
+ * \param[in] size The capacity (number of messages) of the logging target.
+ * \returns A log target in case of success, NULL in case of error.
+ */
+struct log_target *log_target_create_rb(size_t size)
+{
+ struct log_target *target;
+ struct osmo_strrb *rb;
+
+ target = log_target_create();
+ if (!target)
+ return NULL;
+
+ rb = osmo_strrb_create(target, size + 1);
+ if (!rb) {
+ log_target_destroy(target);
+ return NULL;
+ }
+
+ target->tgt_rb.rb = rb;
+ target->type = LOG_TGT_TYPE_STRRB;
+ target->output = _rb_output;
+
+ return target;
+}
+
+/* @} */
diff --git a/src/strrb.c b/src/strrb.c
new file mode 100644
index 0000000..b137acb
--- /dev/null
+++ b/src/strrb.c
@@ -0,0 +1,171 @@
+/* Ringbuffer implementation, tailored for logging.
+ * This is a lossy ringbuffer. It keeps up to N of the newest messages,
+ * overwriting the oldest as newer ones come in.
+ *
+ * (C) 2012-2013, Katerina Barone-Adesi <kat.obsc@gmail.com>
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+/*! \file strrb.c
+ * \brief Lossy string ringbuffer for logging; keeps newest messages.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <strings.h>
+
+#include <osmocom/core/strrb.h>
+
+/* Ringbuffer assumptions, invarients, and notes:
+ * - start is the index of the first used index slot in the ring buffer.
+ * - end is the index of the next index slot in the ring buffer.
+ * - start == end => buffer is empty
+ * - Consequence: the buffer can hold at most size - 1 messages
+ * (if this were not the case, full and empty buffers would be indistinguishable
+ * given the conventions in this implementation).
+ * - Whenever the ringbuffer is full, start is advanced. The second oldest
+ * message becomes unreachable by valid indexes (end is not a valid index)
+ * and the oldest message is overwritten (if there was a message there, which
+ * is the case unless this is the first time the ringbuffer becomes full).
+*/
+
+/*! \brief Create an empty, initialized osmo_strrb.
+ * \param[in] ctx The talloc memory context which should own this.
+ * \param[in] rb_size The number of message slots the osmo_strrb can hold.
+ * \returns A struct osmo_strrb* on success, NULL in case of error.
+ *
+ * This function creates and initializes a ringbuffer.
+ * Note that the ringbuffer stores at most rb_size - 1 messages.
+ */
+
+struct osmo_strrb *osmo_strrb_create(TALLOC_CTX * ctx, size_t rb_size)
+{
+ struct osmo_strrb *rb = NULL;
+ unsigned int i;
+
+ rb = talloc_zero(ctx, struct osmo_strrb);
+ if (!rb)
+ goto alloc_error;
+
+ /* start and end are zero already, which is correct */
+ rb->size = rb_size;
+
+ rb->buffer = talloc_array(rb, char *, rb->size);
+ if (!rb->buffer)
+ goto alloc_error;
+ for (i = 0; i < rb->size; i++) {
+ rb->buffer[i] =
+ talloc_zero_size(rb->buffer, RB_MAX_MESSAGE_SIZE);
+ if (!rb->buffer[i])
+ goto alloc_error;
+ }
+
+ return rb;
+
+alloc_error: /* talloc_free(NULL) is safe */
+ talloc_free(rb);
+ return NULL;
+}
+
+/*! \brief Check if an osmo_strrb is empty.
+ * \param[in] rb The osmo_strrb to check.
+ * \returns True if the osmo_strrb is empty, false otherwise.
+ */
+bool osmo_strrb_is_empty(const struct osmo_strrb *rb)
+{
+ return rb->end == rb->start;
+}
+
+/*! \brief Return a pointer to the Nth string in the osmo_strrb.
+ * \param[in] rb The osmo_strrb to search.
+ * \param[in] string_index The index sought (N), zero-indexed.
+ *
+ * Return a pointer to the Nth string in the osmo_strrb.
+ * Return NULL if there is no Nth string.
+ * Note that N is zero-indexed.
+ * \returns A pointer to the target string on success, NULL in case of error.
+ */
+const char *osmo_strrb_get_nth(const struct osmo_strrb *rb,
+ unsigned int string_index)
+{
+ unsigned int offset = string_index + rb->start;
+
+ if ((offset >= rb->size) && (rb->start > rb->end))
+ offset -= rb->size;
+ if (_osmo_strrb_is_bufindex_valid(rb, offset))
+ return rb->buffer[offset];
+
+ return NULL;
+}
+
+bool _osmo_strrb_is_bufindex_valid(const struct osmo_strrb *rb,
+ unsigned int bufi)
+{
+ if (osmo_strrb_is_empty(rb))
+ return 0;
+ if ((bufi >= rb->size) || (bufi < 0))
+ return 0;
+ if (rb->start < rb->end)
+ return (bufi >= rb->start) && (bufi < rb->end);
+ return (bufi < rb->end) || (bufi >= rb->start);
+}
+
+/*! \brief Count the number of log messages in an osmo_strrb.
+ * \param[in] rb The osmo_strrb to count the elements of.
+ *
+ * \returns The number of log messages in the osmo_strrb.
+ */
+size_t osmo_strrb_elements(const struct osmo_strrb *rb)
+{
+ if (rb->end < rb->start)
+ return rb->end + (rb->size - rb->start);
+
+ return rb->end - rb->start;
+}
+
+/*! \brief Add a string to the osmo_strrb.
+ * \param[in] rb The osmo_strrb to add to.
+ * \param[in] data The string to add.
+ *
+ * Add a message to the osmo_strrb.
+ * Older messages will be overwritten as necessary.
+ * \returns 0 normally, 1 as a warning (ie, if data was truncated).
+ */
+int osmo_strrb_add(struct osmo_strrb *rb, const char *data)
+{
+ size_t len = strlen(data);
+ int ret = 0;
+
+ if (len >= RB_MAX_MESSAGE_SIZE) {
+ len = RB_MAX_MESSAGE_SIZE - 1;
+ ret = 1;
+ }
+
+ memcpy(rb->buffer[rb->end], data, len);
+ rb->buffer[rb->end][len] = '\0';
+
+ rb->end += 1;
+ rb->end %= rb->size;
+
+ /* The buffer is full; oldest message is forgotten - see notes above */
+ if (rb->end == rb->start) {
+ rb->start += 1;
+ rb->start %= rb->size;
+ }
+ return ret;
+}
diff --git a/src/vty/logging_vty.c b/src/vty/logging_vty.c
index d473f12..ace346a 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 @@
#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 @@
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 @@
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 @@
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 @@
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 @@
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);