passt/log.c
Stefano Brivio da152331cf Move logging functions to a new file, log.c
Logging to file is going to add some further complexity that we don't
want to squeeze into util.c.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-14 17:38:25 +02:00

143 lines
3.4 KiB
C

// SPDX-License-Identifier: AGPL-3.0-or-later
/* PASST - Plug A Simple Socket Transport
* for qemu/UNIX domain socket mode
*
* PASTA - Pack A Subtle Tap Abstraction
* for network namespace/tap device mode
*
* log.c - Logging functions
*
* Copyright (c) 2020-2022 Red Hat GmbH
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include <syslog.h>
#include <stdarg.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "log.h"
/* For __openlog() and __setlogmask() wrappers, and passt_vsyslog() */
static int log_mask;
static int log_sock = -1;
static char log_ident[BUFSIZ];
static int log_opt;
static time_t log_debug_start;
int log_trace;
#define logfn(name, level) \
void name(const char *format, ...) { \
struct timespec tp; \
va_list args; \
\
if (setlogmask(0) & LOG_MASK(LOG_DEBUG)) { \
clock_gettime(CLOCK_REALTIME, &tp); \
fprintf(stderr, "%li.%04li: ", \
tp.tv_sec - log_debug_start, \
tp.tv_nsec / (100L * 1000)); \
} else { \
va_start(args, format); \
passt_vsyslog(level, format, args); \
va_end(args); \
} \
\
if (setlogmask(0) & LOG_MASK(LOG_DEBUG) || \
setlogmask(0) == LOG_MASK(LOG_EMERG)) { \
va_start(args, format); \
(void)vfprintf(stderr, format, args); \
va_end(args); \
if (format[strlen(format)] != '\n') \
fprintf(stderr, "\n"); \
} \
}
logfn(err, LOG_ERR)
logfn(warn, LOG_WARNING)
logfn(info, LOG_INFO)
logfn(debug, LOG_DEBUG)
void trace_init(int enable)
{
log_trace = enable;
}
/**
* __openlog() - Non-optional openlog() wrapper, to allow custom vsyslog()
* @ident: openlog() identity (program name)
* @option: openlog() options
* @facility: openlog() facility (LOG_DAEMON)
*/
void __openlog(const char *ident, int option, int facility)
{
struct timespec tp;
clock_gettime(CLOCK_REALTIME, &tp);
log_debug_start = tp.tv_sec;
if (log_sock < 0) {
struct sockaddr_un a = { .sun_family = AF_UNIX, };
log_sock = socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (log_sock < 0)
return;
strncpy(a.sun_path, _PATH_LOG, sizeof(a.sun_path));
if (connect(log_sock, (const struct sockaddr *)&a, sizeof(a))) {
close(log_sock);
log_sock = -1;
return;
}
}
log_mask |= facility;
strncpy(log_ident, ident, sizeof(log_ident) - 1);
log_opt = option;
openlog(ident, option, facility);
}
/**
* __setlogmask() - setlogmask() wrapper, to allow custom vsyslog()
* @mask: Same as setlogmask() mask
*/
void __setlogmask(int mask)
{
log_mask = mask;
setlogmask(mask);
}
/**
* passt_vsyslog() - vsyslog() implementation not using heap memory
* @pri: Facility and level map, same as priority for vsyslog()
* @format: Same as vsyslog() format
* @ap: Same as vsyslog() ap
*/
void passt_vsyslog(int pri, const char *format, va_list ap)
{
char buf[BUFSIZ];
int n;
if (!(LOG_MASK(LOG_PRI(pri)) & log_mask))
return;
/* Send without name and timestamp, the system logger should add them */
n = snprintf(buf, BUFSIZ, "<%i> ", pri);
n += vsnprintf(buf + n, BUFSIZ - n, format, ap);
if (format[strlen(format)] != '\n')
n += snprintf(buf + n, BUFSIZ - n, "\n");
if (log_opt & LOG_PERROR)
fprintf(stderr, "%s", buf + sizeof("<0>"));
if (send(log_sock, buf, n, 0) != n)
fprintf(stderr, "Failed to send %i bytes to syslog\n", n);
}