samba-mirror/ctdb/server/ctdb_logging.c

/* 
   ctdb logging code

   Copyright (C) Andrew Tridgell  2008

   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, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "lib/events/events.h"
#include "../include/ctdb.h"
#include "../include/ctdb_private.h"
#include "system/syslog.h"
#include "system/time.h"
#include "system/filesys.h"

struct syslog_message {
	uint32_t level;
	uint32_t len;
	char message[1];
};


struct ctdb_syslog_state {
	int syslog_fd;
	int fd[2];
};

static int syslogd_is_started = 0;


/* called when child is finished
 * this is for the syslog daemon, we can not use DEBUG here
 */
static void ctdb_syslog_handler(struct event_context *ev, struct fd_event *fde, 
				      uint16_t flags, void *p)
{
	struct ctdb_syslog_state *state = talloc_get_type(p, struct ctdb_syslog_state);

	int count;
	char str[65536];
	struct syslog_message *msg;

	if (state == NULL) {
		return;
	}

	count = recv(state->syslog_fd, str, sizeof(str), 0);
	if (count < sizeof(struct syslog_message)) {
		return;
	}
	msg = (struct syslog_message *)str;

	syslog(msg->level, "%s", msg->message);
}


/* called when the pipd from the main daemon has closed
 * this is for the syslog daemon, we can not use DEBUG here
 */
static void ctdb_syslog_terminate_handler(struct event_context *ev, struct fd_event *fde, 
				      uint16_t flags, void *p)
{
	syslog(LOG_ERR, "Shutting down SYSLOG daemon with pid:%d", (int)getpid());
	_exit(0);
}



/*
 * this is for the syslog daemon, we can not use DEBUG here
 */
int start_syslog_daemon(struct ctdb_context *ctdb)
{
	struct sockaddr_in syslog_sin;
	struct ctdb_syslog_state *state;

	state = talloc(ctdb, struct ctdb_syslog_state);
	CTDB_NO_MEMORY(ctdb, state);

	if (pipe(state->fd) != 0) {
		printf("Failed to create syslog pipe\n");
		talloc_free(state);
		return -1;
	}
	
	ctdb->syslogd_pid = fork();
	if (ctdb->syslogd_pid == (pid_t)-1) {
		printf("Failed to create syslog child process\n");
		close(state->fd[0]);
		close(state->fd[1]);
		talloc_free(state);
		return -1;
	}

	syslogd_is_started = 1;

	if (ctdb->syslogd_pid != 0) {
		DEBUG(DEBUG_ERR,("Starting SYSLOG child process with pid:%d\n", (int)ctdb->syslogd_pid));

		close(state->fd[1]);
		set_close_on_exec(state->fd[0]);

		return 0;
	}

	talloc_free(ctdb->ev);
	ctdb->ev = event_context_init(NULL);

	syslog(LOG_ERR, "Starting SYSLOG daemon with pid:%d", (int)getpid());

	close(state->fd[0]);
	event_add_fd(ctdb->ev, state, state->fd[1], EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
		     ctdb_syslog_terminate_handler, state);

	state->syslog_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
	if (state->syslog_fd == -1) {
		printf("Failed to create syslog socket\n");
		return -1;
	}

	syslog_sin.sin_family = AF_INET;
	syslog_sin.sin_port   = htons(CTDB_PORT);
	syslog_sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);	

	if (bind(state->syslog_fd, &syslog_sin, sizeof(syslog_sin)) == -1) {
		if (errno == EADDRINUSE) {
			/* this is ok, we already have a syslog daemon */
			_exit(0);
		}
		printf("syslog daemon failed to bind to socket. errno:%d(%s)\n", errno, strerror(errno));
		_exit(10);
	}


	event_add_fd(ctdb->ev, state, state->syslog_fd, EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
		     ctdb_syslog_handler, state);

	event_loop_wait(ctdb->ev);

	/* this should not happen */
	_exit(10);
}

struct ctdb_log_state {
	int fd, pfd;
	char buf[1024];
	uint16_t buf_used;
	bool use_syslog;
};

/* we need this global to keep the DEBUG() syntax */
static struct ctdb_log_state *log_state;

/*
  syslog logging function
 */
static void ctdb_syslog_log(const char *format, va_list ap)
{
	struct syslog_message *msg;
	int level = LOG_DEBUG;
	char *s = NULL;
	int len, ret;
	int syslog_fd;
	struct sockaddr_in syslog_sin;

	ret = vasprintf(&s, format, ap);
	if (ret == -1) {
		return;
	}

	switch (this_log_level) {
	case DEBUG_EMERG: 
		level = LOG_EMERG; 
		break;
	case DEBUG_ALERT: 
		level = LOG_ALERT; 
		break;
	case DEBUG_CRIT: 
		level = LOG_CRIT; 
		break;
	case DEBUG_ERR: 
		level = LOG_ERR; 
		break;
	case DEBUG_WARNING: 
		level = LOG_WARNING; 
		break;
	case DEBUG_NOTICE: 
		level = LOG_NOTICE;
		break;
	case DEBUG_INFO: 
		level = LOG_INFO;
		break;
	default:
		level = LOG_DEBUG;
		break;		
	}

	len = offsetof(struct syslog_message, message) + strlen(s) + 1;
	msg = malloc(len);
	if (msg == NULL) {
		free(s);
		return;
	}
	msg->level = level;
	msg->len   = strlen(s);
	strcpy(msg->message, s);

	if (syslogd_is_started == 0) {
		syslog(msg->level, "%s", msg->message);
	} else {
		syslog_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
		if (syslog_fd == -1) {
			printf("Failed to create syslog socket\n");
			free(s);
			free(msg);
			return;
		}

		syslog_sin.sin_family = AF_INET;
		syslog_sin.sin_port   = htons(CTDB_PORT);
		syslog_sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);	

       
		ret = sendto(syslog_fd, msg, len, 0, &syslog_sin, sizeof(syslog_sin));
		/* no point in checking here since we cant log an error */

		close(syslog_fd);
	}

	free(s);
	free(msg);
}


/*
  log file logging function
 */
static void ctdb_logfile_log(const char *format, va_list ap)
{
	struct timeval t;
	char *s = NULL;
	struct tm *tm;
	char tbuf[100];
	char *s2 = NULL;
	int ret;

	ret = vasprintf(&s, format, ap);
	if (ret == -1) {
		const char *errstr = "vasprintf failed\n";

		write(log_state->fd, errstr, strlen(errstr));
		return;
	}

	t = timeval_current();
	tm = localtime(&t.tv_sec);

	strftime(tbuf,sizeof(tbuf)-1,"%Y/%m/%d %H:%M:%S", tm);

	ret = asprintf(&s2, "%s.%06u [%5u]: %s",
		 tbuf, (unsigned)t.tv_usec, (unsigned)getpid(), s);
	free(s);
	if (ret == -1) {
		const char *errstr = "asprintf failed\n";
		write(log_state->fd, errstr, strlen(errstr));
		return;
	}
	if (s2) {
		write(log_state->fd, s2, strlen(s2));
		free(s2);
	}
}

static void ctdb_logfile_log_add(const char *format, va_list ap)
{
	char *s = NULL;
	int ret;

	ret = vasprintf(&s, format, ap);
	if (ret == -1) {
		const char *errstr = "vasprintf failed\n";

		write(log_state->fd, errstr, strlen(errstr));
		return;
	}

	if (s) {
		write(log_state->fd, s, strlen(s));
		free(s);
	}
}



/*
  choose the logfile location
*/
int ctdb_set_logfile(struct ctdb_context *ctdb, const char *logfile, bool use_syslog)
{
	int ret;

	ctdb->log = talloc_zero(ctdb, struct ctdb_log_state);
	if (ctdb->log == NULL) {
		printf("talloc_zero failed\n");
		abort();
	}

	log_state = ctdb->log;

	if (use_syslog) {
		do_debug_v = ctdb_syslog_log;
		do_debug_add_v = ctdb_syslog_log;
		ctdb->log->use_syslog = true;
	} else if (logfile == NULL || strcmp(logfile, "-") == 0) {
		do_debug_v = ctdb_logfile_log;
		do_debug_add_v = ctdb_logfile_log_add;
		ctdb->log->fd = 1;
		/* also catch stderr of subcommands to stdout */
		ret = dup2(1, 2);
		if (ret == -1) {
			printf("dup2 failed: %s\n", strerror(errno));
			abort();
		}
	} else {
		do_debug_v = ctdb_logfile_log;
		do_debug_add_v = ctdb_logfile_log_add;

		ctdb->log->fd = open(logfile, O_WRONLY|O_APPEND|O_CREAT, 0666);
		if (ctdb->log->fd == -1) {
			printf("Failed to open logfile %s\n", logfile);
			abort();
		}
	}

	return 0;
}



/*
  called when log data comes in from a child process
 */
static void ctdb_log_handler(struct event_context *ev, struct fd_event *fde, 
			     uint16_t flags, void *private)
{
	struct ctdb_context *ctdb = talloc_get_type(private, struct ctdb_context);
	char *p;
	int n;

	if (!(flags & EVENT_FD_READ)) {
		return;
	}
	
	n = read(ctdb->log->pfd, &ctdb->log->buf[ctdb->log->buf_used],
		 sizeof(ctdb->log->buf) - ctdb->log->buf_used);
	if (n > 0) {
		ctdb->log->buf_used += n;
	}

	this_log_level = script_log_level;

	while (ctdb->log->buf_used > 0 &&
	       (p = memchr(ctdb->log->buf, '\n', ctdb->log->buf_used)) != NULL) {
		int n1 = (p - ctdb->log->buf)+1;
		int n2 = n1 - 1;
		/* swallow \r from child processes */
		if (n2 > 0 && ctdb->log->buf[n2-1] == '\r') {
			n2--;
		}
		if (script_log_level <= LogLevel) {
			do_debug("%*.*s\n", n2, n2, ctdb->log->buf);
			/* log it in the eventsystem as well */
			ctdb_log_event_script_output(ctdb, ctdb->log->buf, n2);
		}
		memmove(ctdb->log->buf, p+1, sizeof(ctdb->log->buf) - n1);
		ctdb->log->buf_used -= n1;
	}

	/* the buffer could have completely filled - unfortunately we have
	   no choice but to dump it out straight away */
	if (ctdb->log->buf_used == sizeof(ctdb->log->buf)) {
		if (script_log_level <= LogLevel) {
			do_debug("%*.*s\n", 
				(int)ctdb->log->buf_used, (int)ctdb->log->buf_used, ctdb->log->buf);
			/* log it in the eventsystem as well */
			ctdb_log_event_script_output(ctdb, ctdb->log->buf, ctdb->log->buf_used);
		}
		ctdb->log->buf_used = 0;
	}
}



/*
  setup for logging of child process stdout
*/
int ctdb_set_child_logging(struct ctdb_context *ctdb)
{
	int p[2];
	int ret;

	if (ctdb->log->fd == 1) {
		/* not needed for stdout logging */
		return 0;
	}

	/* setup a pipe to catch IO from subprocesses */
	if (pipe(p) != 0) {
		DEBUG(DEBUG_ERR,(__location__ " Failed to setup for child logging pipe\n"));
		return -1;
	}

	event_add_fd(ctdb->ev, ctdb, p[0], EVENT_FD_READ, 
		     ctdb_log_handler, ctdb);
	set_close_on_exec(p[0]);
	ctdb->log->pfd = p[0];

	DEBUG(DEBUG_NOTICE, (__location__ " Created PIPE FD:%d for logging\n", p[0]));

	close(1);
	close(2);
	if (p[1] != 1) {
		ret = dup2(p[1], 1);
		if (ret == -1) {
			printf("dup2 failed: %s\n", strerror(errno));
			return -1;
		}
		close(p[1]);
	}
	/* also catch stderr of subcommands to the log */
	ret = dup2(1, 2);
	if (ret == -1) {
		printf("dup2 failed: %s\n", strerror(errno));
		return -1;
	}

	return 0;
}