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/* SPDX-License-Identifier: MIT
*
* Copyright © 2018 WireGuard LLC. All Rights Reserved.
*/
#include <string.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <time.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/mman.h>
#include "ringlogger.h"
enum {
MAX_LOG_LINE_LENGTH = 512,
MAX_LINES = 1024,
MAGIC = 0xbeefbabeU
};
struct log_line {
struct timeval tv;
char line[MAX_LOG_LINE_LENGTH];
};
struct log {
struct { uint32_t first, len; } header;
struct log_line lines[MAX_LINES];
uint32_t magic;
};
void write_msg_to_log(struct log *log, const char *msg)
{
struct log_line *line = &log->lines[(log->header.first + log->header.len) % MAX_LINES];
if (log->header.len == MAX_LINES)
log->header.first = (log->header.first + 1) % MAX_LINES;
else
++log->header.len;
gettimeofday(&line->tv, NULL);
strncpy(line->line, msg, MAX_LOG_LINE_LENGTH - 1);
line->line[MAX_LOG_LINE_LENGTH - 1] = '\0';
msync(&log->header, sizeof(log->header), MS_ASYNC);
msync(line, sizeof(*line), MS_ASYNC);
}
static bool first_before_second(const struct log_line *line1, const struct log_line *line2)
{
if (line1->tv.tv_sec <= line2->tv.tv_sec)
return true;
if (line1->tv.tv_sec == line2->tv.tv_sec)
return line1->tv.tv_usec <= line2->tv.tv_usec;
return false;
}
int write_logs_to_file(const char *file_name, const struct log *log1, const char *tag1, const struct log *log2, const char *tag2)
{
uint32_t i1, i2, len1 = log1->header.len, len2 = log2->header.len;
FILE *file;
int ret;
if (len1 > MAX_LINES)
len1 = MAX_LINES;
if (len2 > MAX_LINES)
len2 = MAX_LINES;
file = fopen(file_name, "w");
if (!file)
return -errno;
for (i1 = 0, i2 = 0;;) {
struct tm tm;
char buf[MAX_LOG_LINE_LENGTH];
const struct log_line *line1 = &log1->lines[(log1->header.first + i1) % MAX_LINES];
const struct log_line *line2 = &log2->lines[(log2->header.first + i2) % MAX_LINES];
const struct log_line *line;
const char *tag;
if (i1 < len1 && (i2 >= len2 || first_before_second(line1, line2))) {
line = line1;
tag = tag1;
++i1;
} else if (i2 < len2 && (i1 >= len1 || first_before_second(line2, line1))) {
line = line2;
tag = tag2;
++i2;
} else {
break;
}
memcpy(buf, line->line, MAX_LOG_LINE_LENGTH);
buf[MAX_LOG_LINE_LENGTH - 1] = '\0';
if (!localtime_r(&line->tv.tv_sec, &tm))
goto err;
if (fprintf(file, "%04d-%02d-%02d %02d:%02d:%02d.%06d: [%s] %s\n",
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec, line->tv.tv_usec,
tag, buf) < 0)
goto err;
}
errno = 0;
err:
ret = -errno;
fclose(file);
return ret;
}
struct log *open_log(const char *file_name)
{
int fd;
struct log *log;
fd = open(file_name, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
if (fd < 0)
return NULL;
if (ftruncate(fd, sizeof(*log)))
goto err;
log = mmap(NULL, sizeof(*log), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (log == MAP_FAILED)
goto err;
close(fd);
if (log->magic != MAGIC) {
memset(log, 0, sizeof(*log));
log->magic = MAGIC;
msync(log, sizeof(*log), MS_ASYNC);
}
return log;
err:
close(fd);
return NULL;
}
void close_log(struct log *log)
{
munmap(log, sizeof(*log));
}
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