src/log.c

/*
 * oFono - Open Source Telephony
 * Copyright (C) 2008-2011  Intel Corporation
 *
 * SPDX-License-Identifier: GPL-2.0-only
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#define _GNU_SOURCE
#include <stdio.h>
#include <unistd.h>
#include <stdarg.h>
#include <stdlib.h>
#include <syslog.h>
#ifdef HAVE_BACKTRACE
#include <execinfo.h>
#endif
#include <dlfcn.h>

#include <ell/ell.h>

#include "ofono.h"

static const char *program_exec;
static const char *program_path;

/**
 * ofono_info:
 * @format: format string
 * @Varargs: list of arguments
 *
 * Output general information
 */
void ofono_info(const char *format, ...)
{
	va_list ap;

	va_start(ap, format);

	vsyslog(LOG_INFO, format, ap);

	va_end(ap);
}

/**
 * ofono_warn:
 * @format: format string
 * @Varargs: list of arguments
 *
 * Output warning messages
 */
void ofono_warn(const char *format, ...)
{
	va_list ap;

	va_start(ap, format);

	vsyslog(LOG_WARNING, format, ap);

	va_end(ap);
}

/**
 * ofono_error:
 * @format: format string
 * @varargs: list of arguments
 *
 * Output error messages
 */
void ofono_error(const char *format, ...)
{
	va_list ap;

	va_start(ap, format);

	vsyslog(LOG_ERR, format, ap);

	va_end(ap);
}

/**
 * ofono_debug:
 * @format: format string
 * @varargs: list of arguments
 *
 * Output debug message
 *
 * The actual output of the debug message is controlled via a command line
 * switch. If not enabled, these messages will be ignored.
 */
void ofono_debug(const char *format, ...)
{
	va_list ap;

	va_start(ap, format);

	vsyslog(LOG_DEBUG, format, ap);

	va_end(ap);
}

#ifdef HAVE_BACKTRACE
static void print_backtrace(unsigned int offset)
{
	void *frames[99];
	size_t n_ptrs;
	unsigned int i;
	int outfd[2], infd[2];
	int pathlen;
	pid_t pid;

	if (program_exec == NULL)
		return;

	pathlen = strlen(program_path);

	n_ptrs = backtrace(frames, G_N_ELEMENTS(frames));
	if (n_ptrs < offset)
		return;

	if (pipe(outfd) < 0)
		return;

	if (pipe(infd) < 0) {
		close(outfd[0]);
		close(outfd[1]);
		return;
	}

	pid = fork();
	if (pid < 0) {
		close(outfd[0]);
		close(outfd[1]);
		close(infd[0]);
		close(infd[1]);
		return;
	}

	if (pid == 0) {
		close(outfd[1]);
		close(infd[0]);

		dup2(outfd[0], STDIN_FILENO);
		dup2(infd[1], STDOUT_FILENO);

		execlp("addr2line", "-C", "-f", "-e", program_exec, NULL);

		exit(EXIT_FAILURE);
	}

	close(outfd[0]);
	close(infd[1]);

	ofono_error("++++++++ backtrace ++++++++");

	for (i = offset; i < n_ptrs - 1; i++) {
		Dl_info info;
		const char *fname = "???";
		char addr[20], buf[PATH_MAX * 2];
		int len, written;
		char *ptr, *pos;

		if (dladdr(frames[i], &info))
			fname = info.dli_fname;

		len = snprintf(addr, sizeof(addr), "%p\n", frames[i]);
		if (len < 0)
			break;

		written = write(outfd[1], addr, len);
		if (written < 0)
			break;

		len = read(infd[0], buf, sizeof(buf) - 1);
		if (len < 0)
			break;

		buf[len] = '\0';

		pos = strchr(buf, '\n');
		if (!pos)
			break;

		*pos++ = '\0';

		if (strcmp(buf, "??") == 0) {
			ofono_error("#%-2u %p in %s", i - offset,
						frames[i], fname);
			continue;
		}

		ptr = strchr(pos, '\n');
		*ptr++ = '\0';

		if (strncmp(pos, program_path, pathlen) == 0)
			pos += pathlen + 1;

		ofono_error("#%-2u %p in %s() at %s", i - offset,
						frames[i], buf, pos);
	}

	ofono_error("+++++++++++++++++++++++++++");

	kill(pid, SIGTERM);

	close(outfd[1]);
	close(infd[0]);
}

static void signal_handler(int signo)
{
	ofono_error("Aborting (signal %d) [%s]", signo, program_exec);

	print_backtrace(2);

	exit(EXIT_FAILURE);
}

static void signal_setup(sighandler_t handler)
{
	struct sigaction sa;
	sigset_t mask;

	sigemptyset(&mask);
	sa.sa_handler = handler;
	sa.sa_mask = mask;
	sa.sa_flags = 0;
	sigaction(SIGBUS, &sa, NULL);
	sigaction(SIGILL, &sa, NULL);
	sigaction(SIGFPE, &sa, NULL);
	sigaction(SIGSEGV, &sa, NULL);
	sigaction(SIGABRT, &sa, NULL);
	sigaction(SIGPIPE, &sa, NULL);
}
#endif

extern struct ofono_debug_desc __start___debug[];
extern struct ofono_debug_desc __stop___debug[];

static gchar **enabled = NULL;

static ofono_bool_t is_enabled(struct ofono_debug_desc *desc)
{
	int i;

	if (enabled == NULL)
		return FALSE;

	for (i = 0; enabled[i] != NULL; i++) {
		if (desc->name != NULL && g_pattern_match_simple(enabled[i],
							desc->name) == TRUE)
			return TRUE;
		if (desc->file != NULL && g_pattern_match_simple(enabled[i],
							desc->file) == TRUE)
			return TRUE;
	}

	return FALSE;
}

void __ofono_log_enable(struct ofono_debug_desc *start,
					struct ofono_debug_desc *stop)
{
	struct ofono_debug_desc *desc;

	if (start == NULL || stop == NULL)
		return;

	for (desc = start; desc < stop; desc++) {
		if (is_enabled(desc) == TRUE)
			desc->flags |= OFONO_DEBUG_FLAG_PRINT;
	}
}

int __ofono_log_init(const char *program, const char *debug,
						ofono_bool_t detach)
{
	static char path[PATH_MAX];
	int option = LOG_NDELAY | LOG_PID;

	program_exec = program;
	program_path = getcwd(path, sizeof(path));

	if (debug != NULL)
		enabled = g_strsplit_set(debug, ":, ", 0);

	__ofono_log_enable(__start___debug, __stop___debug);

	if (detach == FALSE)
		option |= LOG_PERROR;

#ifdef HAVE_BACKTRACE
	signal_setup(signal_handler);
#endif

	openlog(l_basename(program), option, LOG_DAEMON);

	syslog(LOG_INFO, "oFono version %s", VERSION);

	return 0;
}

void __ofono_log_cleanup(void)
{
	syslog(LOG_INFO, "Exit");

	closelog();

#ifdef HAVE_BACKTRACE
	signal_setup(SIG_DFL);
#endif

	g_strfreev(enabled);
}