diff options
Diffstat (limited to 'plugins/imkmsg/kmsg.c')
| -rw-r--r-- | plugins/imkmsg/kmsg.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/plugins/imkmsg/kmsg.c b/plugins/imkmsg/kmsg.c new file mode 100644 index 00000000..9ad98da4 --- /dev/null +++ b/plugins/imkmsg/kmsg.c @@ -0,0 +1,239 @@ +/* imkmsg driver for Linux /dev/kmsg structured logging + * + * This contains Linux-specific functionality to read /dev/kmsg + * For a general overview, see head comment in imkmsg.c. + * This is heavily based on imklog bsd.c file. + * + * Copyright 2008-2012 Adiscon GmbH + * + * This file is part of rsyslog. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * -or- + * see COPYING.ASL20 in the source distribution + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif +#include <stdlib.h> +#include <time.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> +#include <string.h> +#include <ctype.h> +#include <sys/klog.h> +#include <json/json.h> + +#include "rsyslog.h" +#include "srUtils.h" +#include "debug.h" +#include "imkmsg.h" + +/* globals */ +static int fklog = -1; /* kernel log fd */ + +#ifndef _PATH_KLOG +# define _PATH_KLOG "/dev/kmsg" +#endif + +/* submit a message to imkmsg Syslog() API. In this function, we parse + * necessary information from kernel log line, and make json string + * from the rest. + */ +static void +submitSyslog(uchar *buf) +{ + long offs = 0; + struct timeval tv; + long int timestamp = 0; + struct timespec monotonic; + struct timespec realtime; + char name[1024]; + char value[1024]; + char msg[1024]; + int priority = 0; + long int sequnum = 0; + struct json_object *json = NULL, *jval; + + /* create new json object */ + json = json_object_new_object(); + + /* get priority */ + for (; isdigit(*buf); buf++) { + priority += (priority * 10) + (*buf - '0'); + } + buf++; + + /* get messages sequence number and add it to json */ + for (; isdigit(*buf); buf++) { + sequnum = (sequnum * 10) + (*buf - '0'); + } + buf++; /* skip , */ + jval = json_object_new_int(sequnum); + json_object_object_add(json, "sequnum", jval); + + /* get timestamp */ + for (; isdigit(*buf); buf++) { + timestamp += (timestamp * 10) + (*buf - '0'); + } + buf++; /* skip ; */ + + /* get message */ + offs = 0; + for (; *buf != '\n' && *buf != '\0'; buf++, offs++) { + msg[offs] = *buf; + } + msg[offs] = '\0'; + jval = json_object_new_string((char*)msg); + json_object_object_add(json, "msg", jval); + + if (*buf != '\0') /* message has appended properties, skip \n */ + buf++; + + while (strlen((char *)buf)) { + /* get name of the property */ + buf++; /* skip ' ' */ + offs = 0; + for (; *buf != '=' && *buf != ' '; buf++, offs++) { + name[offs] = *buf; + } + name[offs] = '\0'; + buf++; /* skip = or ' ' */; + + offs = 0; + for (; *buf != '\n' && *buf != '\0'; buf++, offs++) { + value[offs] = *buf; + } + value[offs] = '\0'; + if (*buf != '\0') { + buf++; /* another property, skip \n */ + } + + jval = json_object_new_string((char*)value); + json_object_object_add(json, name, jval); + } + + /* calculate timestamp */ + clock_gettime(CLOCK_MONOTONIC, &monotonic); + clock_gettime(CLOCK_REALTIME, &realtime); + tv.tv_sec = realtime.tv_sec + ((timestamp / 1000000l) - monotonic.tv_sec); + tv.tv_usec = (realtime.tv_nsec + ((timestamp / 1000000000l) - monotonic.tv_nsec)) / 1000; + + Syslog(priority, (uchar *)msg, &tv, json); +} + + +/* open the kernel log - will be called inside the willRun() imkmsg entry point + */ +rsRetVal +klogWillRun(modConfData_t *pModConf) +{ + char errmsg[2048]; + int r; + DEFiRet; + + fklog = open(_PATH_KLOG, O_RDONLY, 0); + if (fklog < 0) { + imkmsgLogIntMsg(RS_RET_ERR_OPEN_KLOG, "imkmsg: cannot open kernel log(%s): %s.", + _PATH_KLOG, rs_strerror_r(errno, errmsg, sizeof(errmsg))); + ABORT_FINALIZE(RS_RET_ERR_OPEN_KLOG); + } + + /* Set level of kernel console messaging.. */ + if(pModConf->console_log_level != -1) { + r = klogctl(8, NULL, pModConf->console_log_level); + if(r != 0) { + imkmsgLogIntMsg(LOG_WARNING, "imkmsg: cannot set console log level: %s", + rs_strerror_r(errno, errmsg, sizeof(errmsg))); + /* make sure we do not try to re-set! */ + pModConf->console_log_level = -1; + } + } + +finalize_it: + RETiRet; +} + +/* Read kernel log while data are available, each read() reads one + * record of printk buffer. + */ +static void +readkmsg(void) +{ + int i; + uchar pRcv[8096+1]; + char errmsg[2048]; + + for (;;) { + dbgprintf("imkmsg waiting for kernel log line\n"); + + /* every read() from the opened device node receives one record of the printk buffer */ + i = read(fklog, pRcv, 8096); + + if (i > 0) { + /* successful read of message of nonzero length */ + pRcv[i] = '\0'; + } else { + /* something went wrong - error or zero length message */ + if (i < 0 && errno != EINTR && errno != EAGAIN) { + /* error occured */ + imkmsgLogIntMsg(LOG_ERR, + "imkmsg: error reading kernel log - shutting down: %s", + rs_strerror_r(errno, errmsg, sizeof(errmsg))); + fklog = -1; + } + break; + } + + submitSyslog(pRcv); + } +} + + +/* to be called in the module's AfterRun entry point + * rgerhards, 2008-04-09 + */ +rsRetVal klogAfterRun(modConfData_t *pModConf) +{ + DEFiRet; + if(fklog != -1) + close(fklog); + /* Turn on logging of messages to console, but only if a log level was speficied */ + if(pModConf->console_log_level != -1) + klogctl(7, NULL, 0); + RETiRet; +} + + +/* to be called in the module's WillRun entry point, this is the main + * "message pull" mechanism. + * rgerhards, 2008-04-09 + */ +rsRetVal klogLogKMsg(modConfData_t __attribute__((unused)) *pModConf) +{ + DEFiRet; + readkmsg(); + RETiRet; +} + + +/* provide the (system-specific) default facility for internal messages + * rgerhards, 2008-04-14 + */ +int +klogFacilIntMsg(void) +{ + return LOG_SYSLOG; +} + |